Display device and method for manufacturing a display device

Abstract

The present invention provides a high-definition display device. Provided is a display device having exceptional display quality. A display device having a first light-emitting element and a second light-emitting element on a first insulating layer, as well as having a second insulating layer and a third insulating layer. The first light-emitting element has a first pixel electrode and a first organic layer. The second light-emitting element has a second pixel electrode and a second organic layer. The first insulating layer has a grooved region provided along a side of the first pixel electrode in a plan view. The grooved region has a first region that overlaps the first pixel electrode and a second region that overlaps the second pixel electrode. The width of the first and second regions is 20-500 nm inclusive. The second insulating layer has a region that is in contact with the upper surface of the first organic layer, a region that is in contact with a side surface of the first organic layer, and a region that is positioned below the first pixel electrode. The third insulating layer has a region that is in contact with the upper surface of the second organic layer, a region that is in contact with a side surface of the second organic layer, and a region that is positioned below the second pixel electrode.

Description

[Technical Field]

[0001] One aspect of the present invention relates to a display device. Another aspect of the present invention relates to a method for manufacturing a display device.

[0002] It should be noted that one aspect of the present invention is not limited to the above-mentioned technical field. Examples of technical fields of one aspect of the present invention disclosed herein include semiconductor devices, display devices, light-emitting devices, energy storage devices, memory devices, electronic devices, lighting devices, input devices, input / output devices, methods for driving them, or methods for manufacturing them. In this specification, the term "semiconductor device" refers to any device that can function by utilizing semiconductor properties. [Background technology]

[0003] In recent years, there has been a growing demand for higher resolution display panels. Devices requiring high-resolution display panels include those for virtual reality (VR), augmented reality (AR), substitutional reality (SR), and mixed reality (MR), which have seen significant development in recent years.

[0004] Furthermore, typical examples of display devices applicable to display panels include liquid crystal displays, organic EL (Electro Luminescence) elements, light-emitting devices equipped with light-emitting elements such as LEDs, and electronic paper that displays information using electrophoretic methods.

[0005] For example, the basic structure of an organic EL element is one in which a layer containing a light-emitting organic compound is sandwiched between a pair of electrodes. By applying a voltage to this element, light emission can be obtained from the light-emitting organic compound. A display device to which such an organic EL element is applied does not require a backlight, which was necessary in a liquid crystal display device or the like, and thus can realize a display device that is thin, lightweight, has high contrast, and consumes low power. For example, an example of a display device using an organic EL element is described in Patent Document 1.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0007] For example, in the above-described wearable devices for VR, AR, SR, or MR, it is necessary to provide a focusing lens between the eye and the display panel. Since a part of the screen is enlarged by the lens, there is a problem that if the fineness of the display panel is low, the sense of reality and immersion will be reduced.

[0008] In addition, the display panel is required to have high color reproducibility. Particularly in the devices for VR, AR, SR, or MR described above, by using a display panel with high color reproducibility, a display close to the actual object color can be performed, and the sense of reality and immersion can be enhanced.

[0009] One aspect of the present invention aims to provide a display device with extremely high definition. One aspect of the present invention aims to provide a display device with high color reproducibility. One aspect of the present invention aims to provide a display device with high brightness. One aspect of the present invention aims to provide a display device with high reliability. One aspect of the present invention aims to provide a display device with low manufacturing cost. Also, one aspect of the present invention aims to provide a method for manufacturing the above-described display device.

[0010] Note that the description of these problems does not prevent the existence of other problems. One aspect of the present invention does not need to solve all of these problems. Other problems can be extracted from the descriptions in the specification, drawings, claims, etc.

Means for Solving the Problems

[0011] One aspect of the present invention includes a first insulating layer, a light-emitting element and a light-receiving element on the first insulating layer, a second insulating layer, a third insulating layer, and a resin layer on the first insulating layer. The light-emitting element has a first pixel electrode, a first organic layer, and a common electrode. The light-receiving element has a second pixel electrode, a second organic layer, and a common electrode. The first organic layer includes a light-emitting layer. The second organic layer includes a photoelectric conversion layer. The first insulating layer has a concave portion, and the concave portion has a region overlapping with the first pixel electrode, a region overlapping with the second pixel electrode, and a region not overlapping with the first pixel electrode and the second pixel electrode. The second insulating layer has a region in contact with the upper surface of the first organic layer, a region in contact with the side surface of the first organic layer, and a region located below the first pixel electrode. The third insulating layer has a region in contact with the upper surface of the second organic layer, a region in contact with the side surface of the second organic layer, and a region located below the second pixel electrode. The resin layer has a region located within the concave portion. The common electrode is provided to cover the upper surface of the resin layer. It is a display device.

[0012] Furthermore, in the above configuration, it is preferable that the insulating layer 2 has a region in contact with the first insulating layer below the first pixel electrode, and the third insulating layer has a region in contact with the first insulating layer below the second pixel electrode.

[0013] Furthermore, in the above configuration, it is preferable that the shortest distance between the end of the first pixel electrode and the end of the second pixel electrode is greater than twice the thickness of the first organic layer.

[0014] Furthermore, in the above configuration, it is preferable that the recess has a downward-convex arc shape in cross-sectional view.

[0015] Furthermore, in the above configuration, it is preferable that the second insulating layer and the third insulating layer each contain aluminum and oxygen.

[0016] Alternatively, one aspect of the present invention comprises a first insulating layer, a second insulating layer and a third insulating layer on the first insulating layer, a light-emitting element on the second insulating layer, a photodetector on the third insulating layer, a fourth insulating layer, a fifth insulating layer, and a resin layer on the first insulating layer, wherein the first insulating layer is an organic insulating layer, the second insulating layer and the third insulating layer are inorganic insulating layers, the light-emitting element comprises a first pixel electrode, a first organic layer, and a common electrode, the photodetector comprises a second pixel electrode, a second organic layer, and a common electrode, the first organic layer includes a light-emitting layer, the second organic layer includes a photoelectric conversion layer, and the first insulating layer has a recess. The display device comprises a recess having a region overlapping with the first pixel electrode, a region overlapping with the second pixel electrode, and a region not overlapping with the first and second pixel electrodes; a fourth insulating layer having a region in contact with the upper surface of the first organic layer, a region in contact with the side surface of the first organic layer, and a region in contact with the second insulating layer below the first pixel electrode; a fifth insulating layer having a region in contact with the upper surface of the second organic layer, a region in contact with the side surface of the second organic layer, and a region in contact with the third insulating layer below the second pixel electrode; a resin layer having a region located within the recess; and a common electrode provided covering the upper surface of the resin layer.

[0017] Alternatively, one aspect of the present invention is a method for manufacturing a display device, comprising: forming a first pixel electrode and a second pixel electrode on a first insulating layer; etching a part of the first insulating layer to form a recess having a region overlapping with the first pixel electrode, a region overlapping with the second pixel electrode, and a region not overlapping with the first and second pixel electrodes; forming a first organic film on the first pixel electrode, on the second pixel electrode, and on the first insulating layer, thereby forming a first organic layer on the first pixel electrode and a second organic layer on the second pixel electrode, forming a second insulating layer on the first organic layer, removing the second organic layer, and forming a second organic film on the first organic layer, on the second pixel electrode, and on the first insulating layer. This is a method for manufacturing a display device, comprising: forming a third organic layer on the second pixel electrode by deposition, forming a fourth organic layer on the first organic layer, forming a third insulating layer on the third organic layer, removing the fourth organic layer, forming resin layers on the first insulating layer, the second insulating layer, and the third insulating layer, and removing a portion of the resin layer, a portion of the second insulating layer, and a portion of the third insulating layer to form a first opening in the resin layer and the second insulating layer that reaches the first organic layer, and forming a second opening in the resin layer and the third insulating layer that reaches the third organic layer, and forming a common electrode so as to overlap with the first organic layer through the first opening and with the third organic layer through the second opening.

[0018] Furthermore, in the above configuration, it is preferable that the first organic film contains a luminescent compound that emits light having intensity in the red wavelength range, the green wavelength range, or the blue wavelength range, and the second organic film contains a luminescent compound that emits light having intensity in a wavelength range of a different color from the first organic film among the red wavelength range, the green wavelength range, and the blue wavelength range.

[0019] Furthermore, in the above configuration, it is preferable that the first organic film contains a luminescent compound and the second organic film contains an organic semiconductor.

[0020] One aspect of the present invention comprises a first insulating layer, a first light-emitting element and a second light-emitting element on the first insulating layer, a second insulating layer, a third insulating layer, and a resin layer on the first insulating layer, wherein the first light-emitting element comprises a first pixel electrode, a first organic layer, and a common electrode, and the second light-emitting element comprises a second pixel electrode, a second organic layer, and a common electrode, wherein the first organic layer and the second organic layer each include a light-emitting layer, and the first insulating layer has a groove-shaped region provided along the edge of the first pixel electrode in a plan view, the groove-shaped region having a first region overlapping with the first pixel electrode and a second pixel The display device has a second region that overlaps with the electrode, the width of the first region being 20 nm to 500 nm, the width of the second region being 20 nm to 500 nm, the second insulating layer having a region in contact with the upper surface of the first organic layer, a region in contact with the side surface of the first organic layer, and a region located below the first pixel electrode, the third insulating layer having a region in contact with the upper surface of the second organic layer, a region in contact with the side surface of the second organic layer, and a region located below the second pixel electrode, the resin layer having a region located within a groove-shaped region, and the common electrode having a region covering the upper surface of the resin layer.

[0021] Furthermore, in the above configuration, it is preferable that the depth of the groove-like region is between 50 nm and 3000 nm.

[0022] Furthermore, in the above configuration, it is preferable that the second insulating layer has a region in contact with the first insulating layer below the first pixel electrode, and the third insulating layer has a region in contact with the first insulating layer below the second pixel electrode.

[0023] Furthermore, in the above configuration, it is preferable that the shortest distance between the end of the first pixel electrode and the end of the second pixel electrode is greater than twice the thickness of the first organic layer.

[0024] Furthermore, in the above configuration, it is preferable that the recess has a downward-convex arc shape in cross-sectional view.

[0025] Furthermore, in the above configuration, it is preferable that the second insulating layer and the third insulating layer each contain aluminum and oxygen.

[0026] Alternatively, one aspect of the present invention comprises a first insulating layer, a second insulating layer and a third insulating layer on the first insulating layer, a first light-emitting element on the second insulating layer, a second light-emitting element on the third insulating layer, a fourth insulating layer, a fifth insulating layer, and a resin layer on the first insulating layer, wherein the first insulating layer is an organic insulating layer, the second insulating layer and the third insulating layer are inorganic insulating layers, the first light-emitting element comprises a first pixel electrode, a first organic layer, and a common electrode, the second element comprises a second pixel electrode, a second organic layer, and a common electrode, the first organic layer and the second organic layer each include a light-emitting layer, and the first insulating layer has a groove-like region provided along the edge of the first pixel electrode in a plan view, groove The display device has a groove-shaped region comprising a first region overlapping with the first pixel electrode and a second region overlapping with the second pixel electrode, the width of the first region being 20 nm to 500 nm, the width of the second region being 20 nm to 500 nm, the fourth insulating layer comprising a region in contact with the upper surface of the first organic layer, a region in contact with the side surface of the first organic layer, and a region in contact with the second insulating layer below the first pixel electrode, the fifth insulating layer comprising a region in contact with the upper surface of the second organic layer, a region in contact with the side surface of the second organic layer, and a region in contact with the third insulating layer below the second pixel electrode, the resin layer comprising a region located within the groove-shaped region, and the common electrode comprising a region covering the upper surface of the resin layer.

[0027] Furthermore, in the above configuration, the depth of the groove-like region is preferably 50 nm or more and 3000 nm or less. [Effects of the Invention]

[0028] According to one aspect of the present invention, it is possible to provide an extremely high-definition display device, or a display device that achieves high color reproducibility, or a high-brightness display device, or a highly reliable display device, or a display device with low manufacturing costs, or a method for manufacturing the above-mentioned display device.

[0029] Furthermore, the description of these effects does not preclude the existence of other effects. Moreover, one aspect of the present invention does not necessarily have to possess all of these effects. Other effects can be extracted from the description in the specification, drawings, claims, etc. [Brief explanation of the drawing]

[0030] Figure 1 shows an example of a display device configuration. Figures 2A and 2B show examples of display device configurations. Figure 3 shows an example of a display device configuration. Figures 4A to 4E show examples of methods for manufacturing a display device. Figures 5A to 5D show examples of methods for manufacturing a display device. Figures 6A to 6C show examples of display device configurations. Figures 7A to 7C illustrate examples of the configuration of a display device. Figures 8A to 8G show examples of pixels. Figures 9A to 9I show examples of pixels. Figures 10A and 10B show examples of display device configurations. Figure 11 shows an example of a display device configuration. Figure 12 shows an example of a display device configuration. Figure 13 shows an example of a display device configuration. Figure 14 shows an example of a display device configuration. Figure 15 shows an example of a display device configuration. Figure 16 shows an example of a display device configuration. Figure 17 shows an example of a display device configuration. Figure 18 shows an example of a display device configuration. Figures 19A to 19C show examples of display device configurations. Figure 20A is a circuit diagram showing an example of the configuration of a display device. Figures 20B to 20D are circuit diagrams showing an example of a pixel circuit. Figures 21A to 21F show examples of the configuration of light-emitting elements. Figures 22A to 22C show examples of the configuration of light-emitting elements. Figures 23A to 23C are cross-sectional views showing an example of a display device. Figure 23D is a diagram showing an example of an image. Figures 24A to 24E are cross-sectional views showing examples of the configuration of a photodetector. Figures 25A to 25D show examples of electronic devices. Figures 26A to 26F show examples of electronic devices. Figures 27A to 27G show examples of electronic devices. Figure 28 shows the measurement results of the peeling force. Figure 29 is a photograph of the display panel. Figure 30 is a cross-sectional view illustrating an example of a display device. Figures 31A and 31B show the results of cross-sectional observation. Figures 32A and 32B show the results of cross-sectional observation. Figures 33A and 33B show the results of cross-sectional observation. Figures 34A and 34B show the results of the peel test. Figure 35 shows the results of the peel test. [Modes for carrying out the invention]

[0031] The embodiments will be described below with reference to the drawings. However, it will be readily apparent to those skilled in the art that the embodiments can be implemented in many different ways, and their form and details can be modified in various ways without departing from the spirit and scope thereof. Accordingly, the present invention shall not be construed as being limited to the contents of the following embodiments.

[0032] In the configuration of the invention described below, the same reference numerals are used in common across different drawings for identical parts or parts having similar functions, and repeated explanations are omitted. Furthermore, when referring to similar functions, the hatch patterns are the same, and reference numerals may not be assigned.

[0033] In the figures described herein, the size of each component, the thickness of the layers, or the area may be exaggerated for clarity. Therefore, the scale is not necessarily limited to those figures.

[0034] Furthermore, ordinal numbers such as "the first," "the second," etc., used in this specification are added to avoid confusion of constituent elements and do not imply any numerical limitation.

[0035] In this specification, holes or electrons may be referred to as "carriers." Specifically, a hole injection layer or electron injection layer may be called a "carrier injection layer," a hole transport layer or electron transport layer may be called a "carrier transport layer," and a hole block layer or electron block layer may be called a "carrier block layer." Note that the above-mentioned carrier injection layer, carrier transport layer, and carrier block layer may not be clearly distinguishable by their cross-sectional shape or characteristics. Furthermore, a single layer may combine the functions of two or three of these carrier injection, carrier transport, and carrier block layers.

[0036] In this specification, a light-emitting element (also called a light-emitting device) has, for example, an EL layer between a pair of electrodes. The EL layer has at least a light-emitting layer. Examples of layers (also called functional layers) that make up the EL layer include a light-emitting layer, a carrier injection layer (hole injection layer and electron injection layer), a carrier transport layer (hole transport layer and electron transport layer), and a carrier blocking layer (hole blocking layer and electron blocking layer).

[0037] Furthermore, in this specification, a light-receiving element (also called a light-receiving device) has, for example, a layer including a photoelectric conversion layer between a pair of electrodes.

[0038] In one embodiment of the present invention, there may be a layer shared by both the light-receiving element and the light-emitting element (which can also be described as a continuous layer shared by both the light-receiving element and the light-emitting element). The function of such a layer may differ between the light-emitting element and the light-receiving element. Furthermore, in this specification, components may be referred to based on their function in the light-emitting element.

[0039] One aspect of the present invention is a display device having a display unit capable of full-color display. The display unit has a first sub-pixel and a second sub-pixel that emit light of different colors, and a third pixel that detects light. The first sub-pixel has a first light-emitting element that emits blue light, and the second sub-pixel has a second light-emitting element that emits light of a different color from the first light-emitting element. The third pixel has a light-receiving element that detects light. The first light-emitting element and the second light-emitting element have at least one different material, for example, different light-emitting materials. In other words, in the display device according to one aspect of the present invention, light-emitting elements that are manufactured separately for each emitted color are used. The light-receiving element has a photoelectric conversion material.

[0040] Furthermore, one aspect of the present invention can capture images using multiple light-receiving elements and therefore functions as an imaging device. In this case, the light-emitting element can be used as a light source for imaging. Also, one aspect of the present invention can display images using multiple light-emitting elements and therefore functions as a display device. Accordingly, one aspect of the present invention can be described as a display device having an imaging function, or an imaging device having a display function.

[0041] For example, in one embodiment of the present invention, a display device has light-emitting elements arranged in a matrix on the display unit, and further, light-receiving elements arranged in a matrix on the display unit. Therefore, the display unit has the function of displaying an image and the function of a light-receiving unit. Since an image can be captured by the multiple light-receiving elements provided on the display unit, the display device can function as an image sensor or the like. That is, it can capture an image with the display unit, or detect when an object approaches or comes into contact with it. Furthermore, since the light-emitting elements provided on the display unit can be used as a light source when receiving light, there is no need to provide a light source separately from the display device, and a highly functional display device can be realized without increasing the number of electronic components.

[0042] In one aspect of the present invention, when an object reflects the light emitted by a light-emitting element of the display unit, a light-receiving element can detect the reflected light, thereby enabling imaging or touch detection (including non-contact) even in dark environments.

[0043] Furthermore, a display device according to one aspect of the present invention can capture a fingerprint or palm print when a finger, palm, or the like is placed in contact with the display unit. Therefore, an electronic device equipped with a display device according to one aspect of the present invention can perform personal authentication using the captured image of a fingerprint or palm print. This eliminates the need to provide a separate imaging device for fingerprint or palm print authentication, thereby reducing the number of components in the electronic device. In addition, since light-receiving elements are arranged in a matrix on the display unit, fingerprints or palm prints can be captured at any location on the display unit, resulting in a highly convenient electronic device.

[0044] Furthermore, a structure in which different light-emitting layers are created or painted for light-emitting elements with different emission wavelengths (e.g., blue (B), green (G), and red (R)) is sometimes called an SBS (Side By Side) structure. Because the SBS structure allows for the optimization of materials and configuration for each light-emitting element, it increases the freedom in selecting materials and configurations, making it easier to improve brightness and reliability.

[0045] When manufacturing a display device having multiple light-emitting elements with different emission colors, it is necessary to form each light-emitting layer with a different emission color in an island-like configuration. Similarly, in light-receiving elements, the photoelectric conversion layer is also formed in an island-like configuration. In this specification, "island-like configuration" refers to a state in which two or more layers made of the same material and formed in the same process are physically separated. For example, an island-like light-emitting layer refers to a state in which the light-emitting layer and an adjacent light-emitting layer are physically separated.

[0046] Furthermore, a display device according to one aspect of the present invention includes a touch sensor that acquires positional information of an object touching or approaching the display surface. Various types of touch sensors can be used, such as resistive, capacitive, infrared, electromagnetic induction, and surface acoustic wave types. In particular, it is preferable to use a capacitive touch sensor.

[0047] Capacitive capacitance methods include surface capacitance and projected capacitance. Projected capacitance methods include self-capacitance and mutual capacitance. Mutual capacitance is preferable because it enables simultaneous multi-point detection.

[0048] A mutual capacitance type touch sensor can have multiple electrodes to which a pulse potential is applied, and multiple electrodes to which a detection circuit is connected. The touch sensor can detect when a finger or other object approaches by utilizing the change in capacitance between the electrodes. It is preferable that the electrodes constituting the touch sensor be placed on the display surface side of the light-emitting element (photodetector).

[0049] The touch sensor is configured such that at least a portion of its electrodes overlaps with a region sandwiched between two adjacent light-emitting elements (photodetectors) or between two adjacent electroluminescent (EL) layers (PS layers). Furthermore, it is preferable that at least a portion of the touch sensor's electrodes overlaps with an organic resin film provided between two adjacent EL layers (PS layers). This configuration allows the touch sensor to be placed on top of the display device without reducing the light-emitting area of ​​the light-emitting elements (photodetectors). Thus, a display device with both a high aperture ratio and high resolution can be provided.

[0050] Here, it is preferable to use a metal or alloy material as the conductive layer that functions as the electrode of the touch sensor. By arranging the electrodes of the touch sensor as described above, a metal or alloy material that does not transmit light can be used as the electrode of the touch sensor without reducing the aperture ratio of the display device. By using a metal or alloy material with low resistance for the electrode of the touch sensor, highly sensitive touch sensing can be achieved.

[0051] Furthermore, a translucent electrode that transmits light emitted by a light-emitting element can be used as the electrode for the touch sensor. In this case, the translucent electrode can be positioned so as to overlap with the light-emitting element (light-receiving element).

[0052] A light-emitting element (photodetector) can be placed between a pair of substrates. The substrates may be rigid, such as a glass substrate, or a flexible film. In this case, the electrodes of the touch sensor can be formed on the substrate located on the display surface side. Alternatively, the electrodes of the touch sensor may be formed on another substrate and bonded to the display surface side.

[0053] Furthermore, it is preferable to place the electrodes of the touch sensor between the pair of substrates mentioned above. In this case, a protective layer covering the light-emitting element (photodetector) can be provided, and the electrodes of the touch sensor can be provided on the protective layer. This reduces the number of parts and simplifies the manufacturing process. In addition, since the thickness of the display device can be reduced, it is particularly suitable when the display device is used as a flexible display using a flexible film on the substrate.

[0054] In this specification, a tapered shape refers to a shape in which at least a portion of the side surface of the structure is inclined with respect to the substrate surface. For example, it is preferable to have a region in which the angle between the inclined side surface and the substrate surface (also called the taper angle) is less than 90°. The side surface of the structure and the substrate surface do not necessarily have to be perfectly flat; they may be substantially planar with a small curvature, or substantially planar with fine irregularities.

[0055] In this specification, a reverse tapered shape refers to a shape in which the angle between at least a portion of the side surface of the structure and the bottom surface is greater than 90°. Alternatively, a reverse tapered shape refers to a shape having a side or top portion that protrudes from the bottom portion in a direction parallel to the substrate.

[0056] Furthermore, if upper and lower numerical limits are specified in this specification, configurations in which the upper and lower numerical limits can be freely combined are also disclosed.

[0057] (Embodiment 1) This embodiment describes a display device according to one aspect of the present invention, and a method for manufacturing the display device.

[0058] A display device according to one aspect of the present invention includes a light-emitting element that emits light of different colors. The light-emitting element comprises a lower electrode, an upper electrode, and a layer containing a light-emitting compound (also called a light-emitting layer) between them. Preferably, an electroluminescent element such as an organic EL element or an inorganic EL element is used as the light-emitting element. In addition, a light-emitting diode (LED) may be used.

[0059] Furthermore, a display device according to one aspect of the present invention includes a light-receiving element. The light-receiving element can detect either or both visible light and infrared light. The light-receiving element includes, for example, a lower electrode, an upper electrode, and a photoelectric conversion layer between them.

[0060] As the light-emitting element, it is preferable to use, for example, an OLED (Organic Light Emitting Diode) or a QLED (Quantum-dot Light Emitting Diode). Examples of light-emitting materials for the light-emitting element include fluorescent materials, phosphorescent materials, thermally activated delayed fluorescence (TADF) materials, and inorganic compounds (quantum dot materials, etc.). In addition, LEDs such as microLEDs (Light Emitting Diodes) can also be used as the light-emitting element.

[0061] The light-emitting element can emit red, green, blue, cyan, magenta, yellow, or white. Furthermore, the color purity can be improved by adding a microcavity structure to the light-emitting element.

[0062] For details regarding the configuration and materials of the light-emitting element, refer to Embodiment 3.

[0063] The light-emitting layer may contain one or more compounds (host material, assist material) in addition to the light-emitting substance (guest material). One or more materials with an energy gap larger than the energy gap of the light-emitting substance (guest material) can be selected and used as the host material and assist material. It is preferable to use a combination of compounds that form an excited complex as the host material and assist material. To efficiently form an excited complex, it is particularly preferable to combine a compound that readily accepts holes (hole transport material) with a compound that readily accepts electrons (electron transport material).

[0064] The light-emitting element can be made from either low-molecular-weight compounds or high-molecular-weight compounds, and may also contain inorganic compounds (such as quantum dot materials).

[0065] A display device according to one aspect of the present invention can create light-emitting elements of different colors with extremely high precision. Therefore, it is possible to realize a display device with higher resolution than conventional display devices. For example, it is preferable to have an extremely high-resolution display device in which pixels having one or more light-emitting elements have a resolution of 2000 ppi or more, preferably 3000 ppi or more, more preferably 5000 ppi or more, and even more preferably 6000 ppi or more, and are arranged with a resolution of 20000 ppi or less, or 30000 ppi or less.

[0066] In the following sections, more specific configuration examples and manufacturing methods of the display device will be described with reference to the drawings.

[0067] [Configuration Example 1] [Configuration Example 1-1] Figures 1, 2A, and 2B illustrate a display device according to one embodiment of the present invention. Figure 1 is a schematic top view of the display device 100A, and Figures 2A and 2B are schematic cross-sectional views of the display device 100A, respectively. Here, Figure 2A is a cross-sectional view of the area indicated by the dashed line A1-A2 in Figure 1, and Figure 2B is a cross-sectional view of the area indicated by the dashed line B1-B2 in Figure 1. Note that some elements have been omitted from the top view of Figure 1 for clarity.

[0068] The display device 100A includes a substrate 101 equipped with a semiconductor circuit, an insulating layer 105, a light-emitting element 110R, a light-emitting element 110G, and a light-emitting element 110B. Preferably, the display device 100A also includes a light-receiving element 110S. In Figures 2A and 2B, the light-emitting elements 110R, 110G, 110B, and the light-receiving element 110S are provided on the insulating layer 105.

[0069] Furthermore, in Figures 2A and 2B, the display device 100A has insulating layers 106 between the insulating layer 105 and the light-emitting element 110R, between the insulating layer 105 and the light-emitting element 110G, between the insulating layer 105 and the light-emitting element 110B, and between the insulating layer 105 and the light-receiving element 110S.

[0070] The insulating layer 105 is preferably an organic insulating film (organic insulating layer), and the insulating layer 106 is preferably an inorganic insulating film (inorganic insulating layer). Alternatively, the insulating layer 105 may be an inorganic insulating film, and the insulating layer 106 may be an organic insulating film.

[0071] In the display device 100A shown in Figure 2A, it is preferable that the organic layer 112 has a region in contact with the upper surface of the pixel electrode 111, a region in contact with the side surface of the pixel electrode 111, and a region in contact with the insulating layer 105. It is also preferable that the organic layer 112 has a region in contact with the side surface of the insulating layer 106. Furthermore, it is preferable that the organic layer 112 has a region in contact with the lower surface of the insulating layer 106. With the configuration shown in Figure 2A, the organic layer 112 can be sealed by the insulating layer 106 and the insulating layer 118. By sealing the organic layer 112 with the insulating layer 106 and the insulating layer 118, for example, it is possible to suppress the peeling of the insulating layer 118 from the organic layer 112. In addition, it is possible to suppress the diffusion of impurities such as water into the organic layer 112.

[0072] In the display device 100A shown in Figure 2B, it is preferable that the PS layer 155S has a region in contact with the upper surface of the pixel electrode 111, a region in contact with the side surface of the pixel electrode 111, and a region in contact with the insulating layer 105. It is also preferable that the PS layer 155S has a region in contact with the side surface of the insulating layer 106. Furthermore, it is preferable that the PS layer 155S has a region in contact with the lower surface of the insulating layer 106. With the configuration shown in Figure 2B, the PS layer 155S can be sealed by the insulating layer 106 and the insulating layer 118d. By sealing the PS layer 155S with the insulating layer 106 and the insulating layer 118d, for example, it is possible to suppress the peeling of the insulating layer 118 from the organic layer 112. In addition, it is possible to suppress the diffusion of impurities such as water into the organic layer 112.

[0073] Furthermore, the display device 100A may have a configuration that does not include an insulating layer 106. Figure 3 differs from Figure 2A in that the display device 100A does not include an insulating layer 106.

[0074] In the display device 100A shown in Figure 3, it is preferable that the organic layer 112 has a region in contact with the upper surface of the pixel electrode 111, a region in contact with the side surface of the pixel electrode 111, and a region in contact with the insulating layer 105. It is also preferable that the organic layer 112 has a region in contact with the lower surface of the pixel electrode 111.

[0075] Furthermore, the insulating layer 105 can be configured as a single layer or a laminated structure of two or more layers as appropriate. For example, the insulating layer 105 may be a laminated structure of an inorganic insulating film and an organic insulating film.

[0076] Light-emitting element 110R is a red-emitting element, light-emitting element 110G is a green-emitting element, and light-emitting element 110B is a blue-emitting element. In other words, light-emitting element 110R and light-emitting element 110G emit light of different colors. Also, light-emitting element 110G and light-emitting element 110B emit light of different colors. Also, light-emitting element 110B and light-emitting element 110R emit light of different colors. A structure in which each light-emitting element is color-coded (here, red (R), green (G), and blue (B)) is sometimes called an SBS (Side By Side) structure.

[0077] In this specification, a structure in which at least the light-emitting layers are made separately for light-emitting elements with different emission wavelengths may be referred to as an SBS (Side By Side) structure. Because the SBS structure allows for the optimization of materials and configuration for each light-emitting element, it increases the freedom of material and configuration selection, making it easier to improve brightness and reliability.

[0078] The light-emitting element 110R has a pixel electrode 111R, an organic layer 112R, a common layer 114, and a common electrode 113. The light-emitting element 110G has a pixel electrode 111G, an organic layer 112G, a common layer 114, and a common electrode 113. The light-emitting element 110B has a pixel electrode 111B, an organic layer 112B, a common layer 114, and a common electrode 113. The common layer 114 and the common electrode 113 are provided in common to the light-emitting elements 110R, 110G, and 110B.

[0079] Organic layer 112R contains a luminescent organic compound that emits light with intensity in at least the red wavelength range. Organic layer 112G contains a luminescent organic compound that emits light with intensity in at least the green wavelength range. Organic layer 112B contains a luminescent organic compound that emits light with intensity in at least the blue wavelength range. Organic layers 112R, 112G, and 112B each have a layer (luminescent layer) containing at least a luminescent organic compound.

[0080] In the following, when explaining matters common to the light-emitting element 110R, light-emitting element 110G, and light-emitting element 110B, the symbols attached to the reference numerals may be omitted, and the element may be referred to simply as "light-emitting element 110." Similarly, the organic layer 112R, organic layer 112G, and organic layer 112B may be referred to simply as "organic layer 112." Similarly, the pixel electrode 111R, pixel electrode 111G, pixel electrode 111B, and pixel electrode 111S may be referred to simply as "pixel electrode 111."

[0081] In the light-emitting element 110, the EL layer may refer to a configuration that combines, for example, the organic layer 112 and the common layer 114.

[0082] Pixel electrodes 111R, 111G, and 111B are provided for each light-emitting element. A common layer 114 and a common electrode 113 are provided as a continuous layer common to each light-emitting element. A conductive film that is transparent to visible light is used on either each pixel electrode or the common electrode 113, while a conductive film that is reflective is used on the other. By making each pixel electrode transparent and the common electrode 113 reflective, a bottom-emission type display device can be created. Conversely, by making each pixel electrode reflective and the common electrode 113 transparent, a top-emission type display device can be created. Furthermore, by making both each pixel electrode and the common electrode 113 transparent, a dual-emission type display device can be created.

[0083] A protective layer 121 is provided on the common electrode 113, covering the light-emitting elements 110R, 110G, and 110B. The protective layer 121 has the function of preventing impurities such as water from diffusing to each light-emitting element from above.

[0084] The light-receiving element 110S can detect either visible light or infrared light, or both. When detecting visible light, it can detect one or more colors such as blue, purple, blue-violet, green, yellow-green, yellow, orange, and red. When detecting infrared light, it is preferable because it enables the detection of objects even in dark places.

[0085] For example, a pn-type or pin-type photodiode can be used as the light-receiving element 110S. The light-receiving element 110S functions as a photoelectric conversion element (also called a photoelectric conversion device) that detects light incident on the light-receiving element 110S and generates an electric charge. The amount of charge generated by the photoelectric conversion element is determined by the amount of incident light.

[0086] In particular, it is preferable to use an organic photodiode having a layer containing an organic compound as the light-receiving element 110S. Organic photodiodes can be easily made thinner, lighter, and larger in area, and because they offer a high degree of freedom in shape and design, they can be applied to a variety of devices.

[0087] In one embodiment of the present invention, there may be a layer shared by both the light-receiving element and the light-emitting element (which can also be described as a continuous layer shared by both the light-receiving element and the light-emitting element). The function of such a layer may differ between the light-emitting element and the light-receiving element. In this specification, components may be referred to based on their function in the light-emitting element. For example, a hole injection layer functions as a hole injection layer in the light-emitting element and as a hole transport layer in the light-receiving element. Similarly, an electron injection layer functions as an electron injection layer in the light-emitting element and as an electron transport layer in the light-receiving element. Furthermore, a layer shared by both the light-receiving element and the light-emitting element may have the same function in both the light-emitting element and the light-receiving element. A hole transport layer functions as a hole transport layer in both the light-emitting element and the light-receiving element, and an electron transport layer functions as an electron transport layer in both the light-emitting element and the light-receiving element.

[0088] In one aspect of the present invention, an organic EL element is used as the light-emitting element, and an organic photodiode is used as the light-receiving element. The organic EL element and the organic photodiode can be formed on the same substrate. Therefore, an organic photodiode can be incorporated into a display device using an organic EL element.

[0089] By driving the photodetector with a reverse bias applied between the pixel electrode and the common electrode, it can detect light incident on the photodetector, generate an electric charge, and extract it as an electric current.

[0090] The photodetector 110S has a pixel electrode 111S, a PS layer 155S, and a common electrode 113. In the configuration shown in Figure 2B, the photodetector 110S also has a common layer 114 between the PS layer 155S and the common electrode 113.

[0091] The PS layer 155S has at least a photoelectric conversion layer (sometimes called an active layer). The layers (also called functional layers) of the PS layer 155S include a photoelectric conversion layer, a carrier injection layer (hole injection layer and electron injection layer), a carrier transport layer (hole transport layer and electron transport layer), and a carrier blocking layer (hole blocking layer and electron blocking layer).

[0092] The photoelectric conversion layer includes a semiconductor. Examples of such semiconductors include inorganic semiconductors such as silicon, and organic semiconductors containing organic compounds. For example, an organic semiconductor can be used as the semiconductor in the photoelectric conversion layer. Using an organic semiconductor is preferable because it allows the light-emitting layer and the photoelectric conversion layer to be formed using the same method (e.g., vacuum deposition), thus enabling the use of common manufacturing equipment. For example, a pn-type or pin-type photodiode can be used as the photoelectric conversion layer.

[0093] As the pixel electrode 111S, the materials and configurations shown for pixel electrode 111R, pixel electrode 111G, pixel electrode 111B, etc., can be used.

[0094] The combination of colors of light emitted by the light-emitting element 110 is not limited to those described above; for example, cyan, magenta, and yellow may also be used. Furthermore, while the above example shows three colors—red (R), green (G), and blue (B)—the number of colors of light emitted by the light-emitting element 110 included in the display device 100A may be two, four, or more.

[0095] The pixel electrode 111 functions as the lower electrode, and the common electrode 113 functions as the upper electrode. The common electrode 113 is transparent and reflective to visible light. The organic layer 112 contains a luminescent compound.

[0096] The light-emitting element 110 can be an electroluminescent element that emits light due to a current flowing through the organic layer 112 when a potential difference is applied between the pixel electrode 111 and the common electrode 113. In particular, it is preferable to use an organic EL element in which a light-emitting organic compound is used for the organic layer 112. Furthermore, it is preferable that the light-emitting element 110 is an element that emits monochromatic light having one peak in the visible light region in its emission spectrum. However, the light-emitting element 110 may also be an element that emits white light having two or more peaks in the visible light region in its emission spectrum.

[0097] Each pixel electrode 111 provided on each light-emitting element 110 is independently supplied with a potential that controls the amount of light emitted by the light-emitting element 110.

[0098] The organic layer 112 and the common layer 114 can each independently have one or more of the following: an electron injection layer, an electron transport layer, a hole injection layer, and a hole transport layer. For example, the organic layer 112 may have a stacked structure of a hole injection layer, a hole transport layer, an emissive layer, and an electron transport layer from the pixel electrode 111 side, and the common layer 114 may have an electron injection layer.

[0099] The common electrode 113 is formed to be both transparent and reflective to visible light. For example, a thin metal film or alloy film that transmits visible light can be used. Alternatively, a light-transmitting conductive film (e.g., a metal oxide film) may be laminated onto such a film.

[0100] In the cross-sectional view of Figure 2A, the edge of the organic layer 112 is located outside the edge of the pixel electrode 111. The edge of the organic layer 112 covers the edge of the pixel electrode 111. By having the edge of the organic layer 112 located outside the edge of the pixel electrode 111, a short circuit between the pixel electrode 111 and the common electrode 113 can be suppressed.

[0101] In the cross-sectional view of Figure 2B, the edge of the PS layer 155S is located outside the edge of the pixel electrode 111. The edge of the PS layer 155S covers the edge of the pixel electrode 111. By having the edge of the PS layer 155S located outside the edge of the pixel electrode 111, a short circuit between the pixel electrode 111 and the common electrode 113 can be suppressed.

[0102] The insulating layer 105 has recesses 175. The recesses 175 are provided in the insulating layer 105 in the region located between two adjacent pixel electrodes 111 in the A1-A2 direction as shown in Figure 1. The recesses 175 are also provided in the insulating layer 105 in the region located between two adjacent pixel electrodes 111 in the B1-B2 direction. The recesses 175 can also be described as a collection of multiple recesses. Alternatively, the recesses 175 can be described as a collection of multiple grooves, for example, with one groove provided between adjacent pixel electrodes 111.

[0103] The recess 175 has a groove-like region. The recess 175 has a groove-like region that, for example, is provided along the edge of the pixel electrode 111 in a top view. In the groove-like region, the recess 175 has a region that overlaps with the pixel electrode 111 on the inside of the edge of the pixel electrode 111 in a top view. Because the recess 175 has a region that overlaps on the inside of the pixel electrode, for example, when forming the organic layer 112, the organic layer 112 can be cut in a step in the region below the pixel electrode 111 on the inside of the edge.

[0104] As shown in Figures 1 and 2A, recesses 175 are provided in the region of the insulating layer 105 located between the light-emitting element 110R and the light-emitting element 110G, recesses 175 are provided in the region of the insulating layer 105 located between the light-emitting element 110G and the light-emitting element 110B, and recesses 175 are provided in the region of the insulating layer 105 located between the light-emitting element 110B and the light-emitting element 110R. Furthermore, as shown in Figures 1 and 2B, recesses 175 are provided in the region of the insulating layer 105 located between the light-emitting element 110G and the light-receiving element 110S.

[0105] Furthermore, as shown in Figure 1, in a top view of the display device 100A, the direction in which the light-emitting elements 110R, 110G, and 110B are arranged in order is defined as the x-direction, and the direction perpendicular to the x-direction is defined as the y-direction. The recess 175 can also be described as a collection of linear grooves extending in the x-direction and linear grooves extending downward in the y-direction.

[0106] Preferably, a portion of the recess 175 is located below the pixel electrode 111. In other words, it is preferable that the recess 175 has a region located below the pixel electrode 111.

[0107] For example, in a recess 175 located between a first pixel electrode and a second pixel electrode, it is preferable that the recess 175 has a first region overlapping with the first pixel electrode, a second region overlapping with the second pixel electrode, and a third region not overlapping with the first or second pixel electrode. The third region is located between the first and second regions. Furthermore, the first region can be said to be located below the first pixel electrode. Furthermore, the second region can be said to be located below the second pixel electrode. Note that the light-emitting element having the first pixel electrode and the light-emitting element having the second pixel electrode emit light of different colors. Alternatively, the first pixel electrode may be included in the light-emitting element, and the second pixel electrode may be included in the photodetector.

[0108] The recess 175 has a downward-convex shape in a cross-sectional view of the display device 100A. For example, the recess 175 has a downward-convex arc shape. Alternatively, the recess 175 may have, for example, a region with a downward-convex arc shape and a region with a flat shape. For example, the side walls of the recess 175 may have a downward-convex arc shape and the bottom surface may have a flat shape.

[0109] The shape of the recess 175 is not particularly limited, as long as a portion of the recess 175 is located below the pixel electrode 111. For example, the recess 175 may have a downward-convex arc shape in a cross-sectional view of the display device, or it may have a flat bottom and downward-convex arc shapes on its side walls.

[0110] Furthermore, the shape of the recess 175 is not limited to the above. For example, the recess 175 may not have to have a region located below the pixel electrode 111. For example, the recess 175 may have a cross-shaped, T-shaped, or inverted T-shaped form in a cross-sectional view of the display device.

[0111] Furthermore, a downward-convex arc shape can also be described as a concave curved surface shape. Additionally, a downward-convex arc shape includes a downward-convex semicircle shape.

[0112] By providing the recess 175, the organic layer 112 of the light-emitting element 110 can be separated from adjacent light-emitting elements 110 or from adjacent photodetectors 110S. Furthermore, by providing the recess 175, the PS layer 155S of the photodetector 110S can be separated from adjacent light-emitting elements 110 or from adjacent photodetectors 110S.

[0113] By forming the film that will become the organic layer 112 on the pixel electrode and in the recess 175, for example, the film that will become the organic layer 112 is cut in the region of the recess 175 that overlaps with the pixel electrode 111. This makes it possible to process the film that will become the organic layer 112 in an island-like manner without using a shadow mask such as a metal mask or etching.

[0114] Furthermore, by forming the film that will become the PS layer 155S on the pixel electrode and in the recess 175, for example, the film that will become the PS layer 155S is cut in the region of the recess 175 that overlaps with the pixel electrode 111. This makes it possible to process the film that will become the organic layer 112 in an island-like manner without using a shadow mask such as a metal mask or etching.

[0115] Furthermore, after cutting the film that will become the organic layer 112 and the film that will become the PS layer 155S in the recess 175, it is preferable to remove the film that remains in the recess 175 from the film that will become the organic layer 112 and the film that will become the PS layer 155S by etching or the like.

[0116] In the display device 100A, the organic layer 112 is divided between adjacent light-emitting elements, between adjacent light-emitting elements and light-receiving elements, or between adjacent light-receiving elements. This prevents current (also called leakage current) from flowing through the organic layer 112 between adjacent elements. Therefore, the light emission caused by such leakage current can be suppressed, enabling a display with high contrast. Furthermore, even when increasing the resolution, a highly conductive material can be used for the organic layer 112, thus broadening the range of material choices and making it easier to improve efficiency, reduce power consumption, and improve reliability.

[0117] The organic layer 112 and the PS layer 155S may form island-like patterns by deposition using a shadow mask such as a metal mask, but it is particularly preferable to use a processing method that does not use a metal mask. This makes it possible to form extremely fine patterns, and thus improves the fineness and aperture ratio compared to the formation method using a metal mask. Typical processing methods that can be used for this purpose include photolithography. Other formation methods such as nanoimprint lithography and sandblasting can also be used.

[0118] In this specification, devices fabricated using a metal mask or an FMM (Fine Metal Mask, a high-resolution metal mask) may be referred to as MM (Metal Mask) structured devices. Furthermore, in this specification, devices fabricated without using a metal mask or an FMM may be referred to as MML (Metal Maskless) structured devices.

[0119] The display device 100A includes an insulating layer 118a on the organic layer 112R, an insulating layer 118b on the organic layer 112G, an insulating layer 118c on the organic layer 112B, an insulating layer 118d on the PS layer 155S, an insulating layer 125, and a resin layer 126.

[0120] In the following, when explaining matters common to insulating layers 118a, 118b, 118c, and 118d, the symbols attached to the reference numerals may be omitted, and the explanation may simply refer to it as insulating layer 118.

[0121] The insulating layer 118 is provided so as to cover at least a portion of the upper surface of the organic layer 112 or the PS layer 155S. Furthermore, the insulating layer 118 is provided so as to overlap at least a portion of the recess 175. As shown in Figure 2A, the insulating layer 118a on the organic layer 112R is provided so as to overlap at least a portion of the recess 175, the insulating layer 118b on the organic layer 112G is provided so as to overlap at least a portion of the recess 175, and the insulating layer 118c on the organic layer 112B is provided so as to overlap at least a portion of the recess 175. Also, as shown in Figure 2B, the insulating layer 118d on the PS layer 155S is provided so as to overlap at least a portion of the recess 175.

[0122] Furthermore, the insulating layer 118 has a region that contacts at least a portion of the upper surface of the organic layer 112 (PS layer 155S), and a region that contacts the side surface of the organic layer 112 (PS layer 155S). In addition, the insulating layer 118 has a region that contacts the insulating layer 105 below the light-emitting element 110 (photodetector 110S), specifically the pixel electrode 111. Furthermore, the insulating layer 118 has a region that contacts the lower surface of the insulating layer 106. By providing a configuration with high adhesion between the insulating layer 106 and the insulating layer 118, it is possible to suppress the peeling of the insulating layer 118 from the organic layer 112 (PS layer 155S), and the peeling of the organic layer 112 (PS layer 155S) from the pixel electrode 111. Furthermore, by providing a configuration with high adhesion between the insulating layer 105 and the insulating layer 118, it is possible to suppress the peeling of the insulating layer 118 from the organic layer 112 (PS layer 155S) and the peeling of the organic layer 112 (PS layer 155S) from the pixel electrode 111. By suppressing film peeling, the yield in the manufacturing process of the display device can be improved. In addition, the display quality of the display device can be improved.

[0123] The adhesion between the insulating layer 105 and the insulating layer 118 is preferably higher than the adhesion between the insulating layer 118 and the organic layer 112. Furthermore, the adhesion between the insulating layer 105 and the insulating layer 118 is preferably higher than the adhesion between the insulating layer 118 and the PS layer 155S.

[0124] When an organic insulating film is used as the insulating layer 105, acrylic resin, polyimide resin, epoxy resin, imide resin, polyamide resin, polyimidoamide resin, silicone resin, siloxane resin, benzocyclobutene resin, phenolic resin, and precursors of these resins can be used. Alternatively, organic materials such as polyvinyl alcohol (PVA), polyvinyl butyral, polyvinylpyrrolidone, polyethylene glycol, polyglycerin, pullulan, water-soluble cellulose, or alcohol-soluble polyamide resin may be used as the insulating layer 105.

[0125] In the preparation of the insulating layer 105, it is preferable to perform baking (heat treatment) after applying the resin. Baking is preferably performed under a reducing atmosphere, for example, in a nitrogen atmosphere.

[0126] When using acrylic resin as the insulating layer 105, the baking temperature is preferably 125°C or higher, more preferably 150°C or higher, and even more preferably 200°C or higher. Baking at such temperatures may improve the adhesion between the insulating layer 105 and the insulating layer 118.

[0127] In addition, the baking temperature for the resin layer 126, which will be described later, may be lower than the baking temperature for the insulating layer 105. The baking temperature for the resin layer 126 is preferably 200°C or lower, more preferably 150°C or lower, and even more preferably 125°C or lower.

[0128] As shown in Figure 2A, the insulating layer 118a has a region in contact with at least a portion of the upper surface of the organic layer 112R, a region in contact with the side surface of the organic layer 112R, and a region in contact with the insulating layer 105 below the pixel electrode 111R. The insulating layer 118a also has a region in contact with the lower surface of the insulating layer 106. The insulating layer 118b has a region in contact with at least a portion of the upper surface of the organic layer 112G, a region in contact with the side surface of the organic layer 112G, and a region in contact with the insulating layer 105 below the pixel electrode 111G. The insulating layer 118b also has a region in contact with the lower surface of the insulating layer 106. The insulating layer 118c has a region in contact with at least a portion of the upper surface of the organic layer 112B, a region in contact with the side surface of the organic layer 112B, and a region in contact with the insulating layer 105 below the pixel electrode 111B. The insulating layer 118c also has a region in contact with the lower surface of the insulating layer 106.

[0129] As shown in Figure 2B, the insulating layer 118d has a region that contacts at least a portion of the upper surface of the PS layer 155S, a region that contacts the side surface of the PS layer 155S, and a region that contacts the insulating layer 105 below the pixel electrode 111S.

[0130] The insulating layer 118 has an opening that reaches the organic layer 112 (PS layer 155S). At this opening, the organic layer 112 (PS layer 155S) is in contact with the common layer 114. The common electrode 113 also has a region that overlaps with the organic layer 112 (PS layer 155S) through this opening.

[0131] The insulating layer 118 has a region located between the resin layer 126 and the organic layer 112 (PS layer 155S), and functions as a protective film to prevent the resin layer 126 from coming into contact with the organic layer 112 (PS layer 155S). If the organic layer 112 (PS layer 155S) and the resin layer 126 come into contact, the organic layer 112 (PS layer 155S) may dissolve due to organic solvents used during the formation of the resin layer 126. Therefore, as shown in this embodiment, by providing the insulating layer 118 between the organic layer 112 (PS layer 155S) and the resin layer 126, it is possible to protect the sides of the organic layer 112 (PS layer 155S).

[0132] The insulating layer 118 can be an insulating layer having an inorganic material. For example, inorganic insulating films such as oxide insulating films, nitride insulating films, oxidative nitride insulating films, and nitride oxide insulating films can be used for the insulating layer 118. The insulating layer 118 may be a single layer or a laminated structure. Examples of oxide insulating films include silicon oxide film, aluminum oxide film, magnesium oxide film, indium gallium zinc oxide film, gallium oxide film, germanium oxide film, yttrium oxide film, zirconium oxide film, lanthanum oxide film, neodymium oxide film, hafnium oxide film, and tantalum oxide film. Examples of nitride insulating films include silicon nitride film and aluminum nitride film. Examples of oxidative nitride insulating films include silicon oxidative nitride film and aluminum oxidative nitride film. Examples of nitride oxide insulating films include silicon nitride film and aluminum nitride film. In particular, by applying an aluminum oxide film, a metal oxide film such as a hafnium oxide film, or an inorganic insulating film such as a silicon oxide film, formed by the ALD method, an insulating layer 118 can be formed that has few pinholes and excellent function in protecting the organic layer 112.

[0133] In this specification, the term "oxide-nitride" refers to a material in which the oxygen content is greater than the nitrogen content, and the term "nitride oxide" refers to a material in which the nitrogen content is greater than the oxygen content. For example, when "silicon oxynitride" is written, it refers to a material in which the oxygen content is greater than the nitrogen content, and when "silicon nitride oxide" is written, it refers to a material in which the nitrogen content is greater than the oxygen content.

[0134] Furthermore, the insulating layer 118 may function as a protective layer to prevent impurities such as water from diffusing into the organic layer 112 and the PS layer 155S. It is preferable to use an inorganic insulating film with low moisture permeability, such as a silicon oxide film, a silicon nitride film, or an aluminum oxide film, for the insulating layer 118. When aluminum oxide is used for the insulating layer 118, the insulating layer 118 will be an insulating layer having aluminum and oxygen.

[0135] The insulating layer 118 can be formed using sputtering, CVD, PLD, or ALD methods. It is preferable to form the insulating layer 118 using the ALD method, which provides good coverage.

[0136] The thickness of the insulating layer 118 is preferably 3 nm or more, 5 nm or more, or 10 nm or more, and 200 nm or less, 150 nm or less, 100 nm or less, or 50 nm or less.

[0137] Between adjacent light-emitting elements of different colors, the sides of each organic layer 112 are positioned opposite each other with a resin layer 126 in between. The resin layer 126 is located between adjacent light-emitting elements of different colors and is provided to fill the edges of each organic layer 112 and the region between the two organic layers 112.

[0138] Furthermore, in adjacent light-emitting elements and light-receiving elements, the side surface of the organic layer 112 of the light-emitting element and the side surface of the PS layer 155S of the light-receiving element are provided facing each other with a resin layer 126 in between. The resin layer 126 is located between adjacent light-emitting elements and light-receiving elements and is provided to fill the region between the end of the organic layer 112 and the end of the PS layer 155S, and the region between the organic layer 112 and the PS layer 155S.

[0139] Furthermore, in a display device according to one aspect of the present invention, if the light-receiving elements are adjacent to each other, the sides of the PS layers 155S of adjacent light-receiving elements are provided facing each other with a resin layer 126 in between. The resin layer 126 is located between adjacent light-receiving elements and is provided to fill the edges of each PS layer 155S and the region between the two PS layers 155S.

[0140] The resin layer 126 has a smooth, convex upper surface shape, and the common layer 114 and common electrode 113 are provided covering the upper surface of the resin layer 126.

[0141] The resin layer 126 has regions that are in contact with the insulating layer 105 between adjacent light-emitting elements and between adjacent light-emitting elements and light-receiving elements. For example, the resin layer 126 has a region that is in contact with the insulating layer 105 in the portion located between the organic layer 112R and the organic layer 112G. The resin layer 126 also has a region that is in contact with the insulating layer 105 in the portion located between the organic layer 112G and the organic layer 112B. The resin layer 126 also has a region that is in contact with the insulating layer 105 in the portion located between the organic layer 112B and the organic layer 112R. The resin layer 126 also has a region that is in contact with the insulating layer 105 in the portion located between the PS layer 155S and the organic layer 112.

[0142] The resin layer 126 functions as a planarizing film that fills in steps located between adjacent light-emitting elements, and steps located between adjacent light-emitting elements and photodetectors. By providing the resin layer 126, the phenomenon of the common electrode 113 being separated by steps at the edges of the organic layer 112 and the PS layer 155S (also called step breakage) can be suppressed, and the common electrode 113 on the organic layer 112 can be prevented from becoming insulated. The resin layer 126 can also be called LFP (Local Filling Planarization).

[0143] As the resin layer 126, an insulating layer having an organic material can be suitably used. For example, as the resin layer 126, acrylic resin, polyimide resin, epoxy resin, imide resin, polyamide resin, polyimidoamide resin, silicone resin, siloxane resin, benzocyclobutene resin, phenol resin, and precursors of these resins can be used. Alternatively, as the resin layer 126, organic materials such as polyvinyl alcohol (PVA), polyvinyl butyral, polyvinylpyrrolidone, polyethylene glycol, polyglycerin, pullulan, water-soluble cellulose, or alcohol-soluble polyamide resin may be used.

[0144] Furthermore, a photosensitive resin can be used as the resin layer 126. A photoresist may be used as the photosensitive resin. The photosensitive resin can be a positive-type material or a negative-type material.

[0145] The resin layer 126 may contain a material that absorbs visible light. For example, the resin layer 126 itself may be composed of a material that absorbs visible light, or the resin layer 126 may contain a pigment that absorbs visible light. As the resin layer 126, for example, a resin that can be used as a color filter that transmits red, blue, or green light and absorbs other light, or a resin that contains carbon black as a pigment and functions as a black matrix can be used.

[0146] Furthermore, insulating layers 125 are provided between the resin layer 126 and the insulating layer 118a, between the resin layer 126 and the insulating layer 118b, and between the resin layer 126 and the insulating layer 118c. The insulating layer 125 has openings that reach the organic layer 112 (PS layer 155S). Note that the display device 100A may be configured without insulating layers 125.

[0147] A protective layer 121 is provided covering the common electrode 113.

[0148] The protective layer 121 can be, for example, a single-layer structure or a multilayer structure including at least an inorganic insulating film. Examples of inorganic insulating films include oxide films or nitride films such as silicon oxide film, silicon oxide nitride film, silicon oxide nitride film, silicon nitride film, aluminum oxide film, aluminum oxide nitride film, and hafnium oxide film. Alternatively, semiconductor materials or conductive materials such as indium gallium oxide, indium zinc oxide, indium tin oxide, and indium gallium zinc oxide may be used as the protective layer 121.

[0149] As the protective layer 121, a laminated film of an inorganic insulating film and an organic insulating film can also be used. For example, it is preferable to have a configuration in which an organic insulating film is sandwiched between a pair of inorganic insulating films. Furthermore, it is preferable that the organic insulating film functions as a planarizing film. This makes the upper surface of the organic insulating film flat, thereby improving the coverage of the inorganic insulating film on top of it and enhancing its barrier properties. In addition, since the upper surface of the protective layer 121 is flat, it is preferable because it reduces the influence of uneven shapes caused by the structure below when a structure (e.g., a color filter, touch sensor electrodes, or lens array, etc.) is provided above the protective layer 121.

[0150] Although not shown in Figure 2B, it is preferable that the common electrode 113 extends to an area outside the end of the recess 175.

[0151] By adopting this configuration, the EL layer of the light-emitting element 110 can be made differently for each light-emitting element of a different color, enabling color display with high color reproduction and low power consumption.

[0152] The substrate 101 can be a circuit board having transistors or wiring. If a passive matrix or segment method is applicable, an insulating substrate such as a glass substrate can be used as the substrate 101. Furthermore, the substrate 101 is a substrate on which semiconductor circuits function as circuits for driving each light-emitting element (also called pixel circuits), or as drive circuits for driving said pixel circuits. More specific examples of the substrate 101 configuration will be described later.

[0153] The substrate 101 and the pixel electrodes 111 of the light-emitting element 110 are electrically connected via a conductive layer.

[0154] The width W1 shown in Figure 2A is the width of the recess 175 in the A1-A2 direction that does not overlap with the pixel electrode 111. In the display device 100A shown in Figure 2A, the width W1 can be rephrased as the shortest distance between the ends of the pixel electrodes 111 that are facing each other. Also, the width W2 shown in Figure 2A is the width of the recess 175 in the A1-A2 direction that overlaps with the pixel electrode 111.

[0155] Figure 30 shows an enlarged view of the region including widths W1 and W2 in Figure 2A. Figure 30 also shows the depth W5 of the recess 175. Depth W5 is, for example, the difference between the height of the bottom of the recess 175 and the height of the top surface of the insulating layer 105. The widths W1 and W2 of the recess 175, the height of the bottom, and the height of the top surface of the insulating layer 105 can be measured, for example, by a cross-sectional observation image of the display device 100A. The cross-sectional observation image can be observed using, for example, a TEM (Transmission Electron Microscope), STEM (Scanning Transmission Electron Microscope), etc. The cross-sectional observation image can be measured by processing to expose the cross-section and using the height within the observation range. For example, the height of the bottom of the recess 175 can be calculated by calculating the average height within the observation range. Alternatively, the height of the bottom of the recess 175 can be measured at the point where the recess 175 is deepest in the observed region. The height of the top surface of the insulating layer 105 can be calculated, for example, by averaging the heights within the observation area. Alternatively, the height of the top surface of the insulating layer 105 can be measured by finding the point where the top surface of the insulating layer 105 is highest within the observed area.

[0156] Furthermore, if multiple recesses 175 are observed within the observation range, the widths W1, W2, and depths W5 of the recesses may be the average, maximum, minimum, or median values ​​of these recesses.

[0157] The width W1 is preferably greater than twice the film thickness of the organic layer 112 (PS layer 155S). For example, if the film thickness of the organic layer 112 (PS layer 155S) is 100 nm, the width W1 is 200 nm or more and 1200 nm or less, preferably 200 nm or more and 1000 nm or less, and more preferably 200 nm or more and 900 nm or less. This causes a step break in the organic layer 112 (PS layer 155S) due to the recess 175, allowing the organic layer 112 (PS layer 155S) to be formed on the pixel electrode 111. At this time, as shown in Figure 2A, the organic layer 112 (PS layer 155S) is arranged to cover the side and top surfaces of the pixel electrode 111. In this specification, etc., when a layer covers a structure, it means that the layer covers a part of the end face of the structure, or that the layer completely covers the end face of the structure so as to wrap around it. Here, the layer is an insulating layer, an insulating film, or a conductive layer, etc. Furthermore, the structure may include a conductive layer, an organic layer, a laminate, or a light-emitting element.

[0158] The width W1 should be adjusted as appropriate according to the processing accuracy when forming the recess 175, the film deposition conditions for the organic layer 112 (PS layer 155S), etc. When the organic layer 112 (PS layer 155S) is deposited using, for example, a vacuum deposition method, even if the width W1 is less than twice the film thickness of the organic layer 112 (PS layer 155S), a step break may occur in the organic layer 112 (PS layer 155S). For example, if the film thickness of the organic layer 112 (PS layer 155S) is 100 nm, the width W1 may be 100 nm or more, and 1200 nm or less, 1000 nm or less, or 900 nm or less.

[0159] Furthermore, the width W2 should be such that a step break occurs in the organic layer 112 (PS layer 155S). Preferably, the width W2 is 2 nm or more, 5 nm or more, 10 nm or more, 20 nm or more, 30 nm or more, 40 nm or more, or 50 nm or more. By increasing the width W2, a step break can be created in the organic layer 112. Also, by increasing the width W2, adhesion can be improved due to the anchoring effect of the organic layer 112. However, if the value of the width W2 is too large, there is a concern that the aperture ratio of the display device will decrease. Therefore, preferably, the width W2 is 500 nm or less, 300 nm or less, 200 nm or less, 150 nm or less, or 100 nm or less.

[0160] Furthermore, the width W2 is preferably 20 nm to 500 nm, more preferably 30 nm to 300 nm, even more preferably 40 nm to 200 nm, and even more preferably 50 nm to 150 nm, and is preferably about 90 nm. By setting the width W2 to a suitable range, the organic layer 112 can be stepped while maintaining a high aperture ratio even in high-definition displays, and a part of the insulating layer 118 can be in contact with the lower surface of the insulating layer 106 and the side surface of the insulating layer 105, effectively suppressing the peeling of the insulating layer 118 from the organic layer 112 (PS layer 155S). In addition, the anchoring effect of the organic layer 112 can improve adhesion.

[0161] The widths W1, W2, and depth W5 can be measured, for example, using a cross-sectional image of the display device observed with an electron microscope. Preferably, the cross-section to be observed is approximately perpendicular to the edges of the pixel electrodes 111 when viewed from above. In this case, the cross-section should be processed to be approximately perpendicular in the region where the edges are approximately straight lines, and then the cross-section should be observed.

[0162] Furthermore, in the region where the recess 175 is provided in a groove shape, the widths W1 and W2 should be measured in the width direction of the groove.

[0163] Furthermore, the depth W5 is, for example, 20 nm or more, or 50 nm to 3000 nm, or 100 nm to 2000 nm, or 200 nm to 1000 nm.

[0164] In a display device according to one aspect of the present invention, by setting the width W2 to the above-mentioned width, the organic layer 112 can be suitably cut in steps. Furthermore, by setting the width W2 to the above-mentioned width, the organic layer 112 can be suitably cut even when one or more of the insulating layer 106 and the pixel electrode 111 have a tapered shape.

[0165] Furthermore, in a display device according to one aspect of the present invention, by configuring a part of the insulating layer 118 to be in contact with the lower surface of the insulating layer 106 and the side surface of the insulating layer 105, the organic layer 112 can be sealed by the pixel electrode 111, the insulating layer 118, the insulating layer 106, and the insulating layer 105. The above sealing is performed in the area surrounding the pixel electrode 111. Therefore, better sealing can be achieved when the circumference of the pixel electrode is sufficiently large relative to the area of ​​the pixel electrode 111 in a plan view. Therefore, better sealing can be achieved in display devices with a smaller area of ​​the pixel electrode 111 and higher resolution. For example, better sealing may be possible at resolutions of 400 ppi or higher, more preferably 600 ppi or higher.

[0166] Based on the above, it is possible to realize an extremely high-resolution display device in which pixels having one or more light-emitting elements have a resolution of 2000 ppi or more, preferably 3000 ppi or more, more preferably 5000 ppi or more, and even more preferably 6000 ppi or more, and are arranged at a resolution of 20000 ppi or less, or 30000 ppi or less.

[0167] Furthermore, by adjusting the thickness of the EL layer on the light-emitting element 110 to match the peak wavelength of the emission spectrum, a microcavity structure (micro-resonator structure) can be created, enabling the realization of a high-brightness display device. Additionally, it becomes possible to arrange the light-emitting elements 110 at extremely high density. For example, a display device with a resolution exceeding 2000 ppi can be realized.

[0168] To realize a microcavity structure, the thickness of the EL layer of the light-emitting element 110 may be adjusted to match the peak wavelength of the emission spectrum. For example, the organic layer 112R of the light-emitting element 110R that emits the longest wavelength light is the thickest, and the organic layer 112B of the light-emitting element 110B that emits the shortest wavelength light is the thinnest. However, this is not limited to this, and the thickness of each organic layer can be adjusted by considering the wavelength of light emitted by each light-emitting element, the optical properties of the layers constituting the light-emitting element, and the electrical properties of the light-emitting element.

[0169] In the above, the width W1 is preferably greater than twice the film thickness of the thinnest organic layer 112 (PS layer 155S), and more preferably greater than twice the film thickness of the thickest organic layer 112 (PS layer 155S). This causes a step break in the organic layer 112 (PS layer 155S) due to the recess 175, allowing the organic layer 112 (PS layer 155S) to be formed on the pixel electrode 111. Furthermore, a microcavity structure can be realized.

[0170] The width W3 shown in Figure 2B is the width of the recess 175 in the B1-B2 direction that does not overlap with the pixel electrode 111. In the display device 100A shown in Figure 2B, the width W3 can be rephrased as the shortest distance between the ends of the opposing pixel electrodes 111. Also, the width W4 shown in Figure 2B is the width of the recess 175 in the B1-B2 direction that overlaps with the pixel electrode 111.

[0171] For width W3, refer to the description for width W1. Similarly, for width W4, refer to the description for width W2.

[0172] [About the components] [Light-emitting element] The light-emitting element that can be used in the light-emitting element 110 can be a self-emitting element, and this category includes elements whose brightness can be controlled by current or voltage. For example, LEDs, organic EL elements, inorganic EL elements, etc., can be used. In particular, the use of organic EL elements is preferred.

[0173] Light-emitting elements include top-emission, bottom-emission, and dual-emission types. The electrode that extracts light uses a conductive film that transmits visible light. The electrode that does not extract light uses a conductive film that reflects visible light.

[0174] In one aspect of the present invention, a top-emission or dual-emission type light-emitting element that emits light particularly on the side opposite to the surface to be formed can be suitably used.

[0175] The organic layer 112 has at least an emissive layer. The organic layer 112 may further have layers other than the emissive layer that include a material with high hole injection properties, a material with high hole transport properties, a hole blocking material, a material with high electron transport properties, a material with high electron injection properties, an electron blocking material, or a bipolar material (a material with high electron transport and hole transport properties).

[0176] The organic layer 112 may use either low-molecular-weight compounds or high-molecular-weight compounds, and may also contain inorganic compounds. Each of the layers constituting the organic layer 112 can be formed by methods such as vapor deposition (including vacuum deposition), transfer, printing, inkjet, and coating.

[0177] When a voltage higher than the threshold voltage of the light-emitting element 110 is applied between the cathode and anode, holes are injected into the organic layer 112 from the anode side and electrons are injected from the cathode side. The injected electrons and holes recombine in the organic layer 112, causing the light-emitting material contained in the organic layer 112 to emit light.

[0178] When a white-emitting light-emitting element is used as the light-emitting element 110, it is preferable to have a configuration in which the organic layer 112 contains two or more types of light-emitting materials. For example, white emission can be obtained by selecting two or more light-emitting materials such that the emission of each of the two or more materials is in a complementary color relationship. For example, it is preferable to include two or more light-emitting materials that emit R (red), G (green), B (blue), Y (yellow), O (orange), etc., or light-emitting materials that emit light containing spectral components of two or more colors from R, G, and B. Furthermore, it is preferable to use a light-emitting element in which the emission spectrum from the light-emitting element has two or more peaks within the wavelength range of the visible light region (for example, 350 nm to 750 nm). In addition, it is preferable that the emission spectrum of a material having a peak in the yellow wavelength region also has spectral components in the green and red wavelength regions.

[0179] The organic layer 112 is preferably configured by laminating an emissive layer containing an emissive material that emits one color and an emissive layer containing an emissive material that emits another color. For example, the multiple emissive layers in the organic layer 112 may be laminated in contact with each other, or they may be laminated with regions that do not contain any emissive material in between. For example, a region may be provided between a fluorescent emissive layer and a phosphorescent emissive layer that contains the same material as the fluorescent emissive layer or the phosphorescent emissive layer (e.g., host material, assist material) but does not contain any emissive material. This makes it easier to manufacture the light-emitting device and reduces the driving voltage.

[0180] Furthermore, the light-emitting element 110 may be a single element having one EL layer, or it may be a tandem element in which multiple EL layers are stacked with a charge generation layer in between.

[0181] A single-structure device preferably has one light-emitting unit between a pair of electrodes, and the light-emitting unit is preferably configured to include one or more light-emitting layers. When obtaining white light emission using two light-emitting layers, the light-emitting layers should be selected such that the light-emitting colors of each of the two layers are complementary colors. For example, by making the light-emitting color of the first light-emitting layer and the light-emitting color of the second light-emitting layer complementary colors, a configuration that emits white light as a whole can be obtained. Also, when obtaining white light emission using three or more light-emitting layers, the light-emitting layer can be configured so that the light-emitting layer as a whole emits white light when the light-emitting colors of each of the three or more layers are combined.

[0182] A tandem device preferably has two or more light-emitting units between a pair of electrodes, and each light-emitting unit preferably includes one or more light-emitting layers. To obtain white light emission, the device should be configured such that the light from the light-emitting layers of the multiple light-emitting units is combined to produce white light emission. The configuration for obtaining white light emission is the same as that for a single-structure device. In a tandem device, it is preferable to provide an intermediate layer, such as a charge-generating layer, between the multiple light-emitting units.

[0183] A conductive film that transmits visible light, which can be used for pixel electrodes 111, etc., can be formed using, for example, indium oxide, indium tin oxide, indium zinc oxide, zinc oxide, or zinc oxide with gallium added. Metal materials such as gold, silver, platinum, magnesium, nickel, tungsten, chromium, molybdenum, iron, cobalt, copper, palladium, or titanium, alloys containing these metal materials, or nitrides of these metal materials (e.g., titanium nitride) can also be used by forming them thinly enough to be translucent. Furthermore, a laminated film of the above materials can be used as a conductive layer. For example, using a laminated film of a silver-magnesium alloy and indium tin oxide is preferable because it can enhance conductivity. Graphene may also be used.

[0184] It is preferable to use a conductive film that reflects visible light in the portion of the pixel electrode 111 located on the organic layer 112 side. As the conductive film, for example, a metallic material such as aluminum, gold, platinum, silver, nickel, tungsten, chromium, molybdenum, iron, cobalt, copper, or palladium, or an alloy containing these metallic materials, can be used. Silver is preferred because it has a high reflectivity of visible light. Aluminum is also preferred because it is easy to process as the electrode is easily etched, and it has a high reflectivity of visible light and near-infrared light. Lanthanum, neodymium, or germanium may also be added to the metallic material or alloy. Alternatively, an alloy containing titanium, nickel, or neodymium and aluminum (aluminum alloy) may be used. Alternatively, an alloy containing copper, palladium, magnesium, and silver may be used. An alloy containing silver and copper is preferred because it has high heat resistance.

[0185] Alternatively, the pixel electrode 111 may be configured by laminating a conductive metal oxide film on a conductive film that reflects visible light. This configuration can suppress oxidation or corrosion of the conductive film that reflects visible light. For example, oxidation can be suppressed by laminating a metal film or metal oxide film in contact with an aluminum film or aluminum alloy film. Examples of materials for such metal films and metal oxide films include titanium or titanium oxide. Alternatively, a conductive film that transmits visible light and a film made of a metal material may be laminated. For example, a laminated film of silver and indium tin oxide, or a laminated film of a silver-magnesium alloy and indium tin oxide can be used.

[0186] When aluminum is used as the pixel electrode 111, a thickness of 40 nm or more, more preferably 70 nm or more, can be used to sufficiently increase the reflectivity of visible light and the like. When silver is used as the pixel electrode 111, a thickness of 70 nm or more, more preferably 100 nm or more, can be used to sufficiently increase the reflectivity of visible light and the like.

[0187] As a conductive film having light transmission and reflectivity that can be used for the common electrode 113, a film can be used in which the conductive film that reflects visible light is formed to a thickness that allows visible light to pass through. Furthermore, by forming a laminated structure of the conductive film and the conductive film that transmits visible light, the conductivity or mechanical strength can be increased.

[0188] A conductive film having light-transmitting and reflective properties preferably has a reflectance to visible light (for example, reflectance to light of a predetermined wavelength within the range of 400 nm to 700 nm) of 20% to 80%, more preferably 40% to 70%. Furthermore, a conductive film having reflective properties preferably has a reflectance to visible light of 40% to 100%, more preferably 70% to 100%. Furthermore, a conductive film having light-transmitting properties preferably has a reflectance to visible light of 0% to 40%, more preferably 0% to 30%.

[0189] As the pixel electrode 111 that functions as the lower electrode, metal materials such as gold, silver, platinum, magnesium, nickel, tungsten, chromium, molybdenum, iron, cobalt, copper, palladium, or titanium, alloys containing these metal materials, or nitrides of these metal materials (e.g., titanium nitride) can be used.

[0190] The electrodes constituting the light-emitting element can be formed using methods such as vapor deposition or sputtering. Alternatively, they can be formed using ejection methods such as inkjet printing, printing methods such as screen printing, or plating methods.

[0191] Furthermore, the layers described above, including the light-emitting layer and the material containing a material with high hole injection, high hole transport, high electron transport, and high electron injection, as well as a bipolar material, may each contain inorganic compounds such as quantum dots, or polymer compounds (oligomers, dendrimers, polymers, etc.). For example, quantum dots can be used in the light-emitting layer to function as a light-emitting material.

[0192] Furthermore, as quantum dot materials, colloidal quantum dot materials, alloy-type quantum dot materials, core-shell type quantum dot materials, and core-type quantum dot materials can be used. Materials containing elemental groups from groups 12 and 16, 13 and 15, or 14 and 16 may also be used. Alternatively, quantum dot materials containing elements such as cadmium, selenium, zinc, sulfur, phosphorus, indium, tellurium, lead, gallium, arsenic, and aluminum may be used.

[0193] It is preferable that each light-emitting element is adjusted such that the optical distance between the surface of its reflective layer that reflects visible light and the common electrode 113, which is transparent and reflective to visible light, is m × λ / 2 (where m is an integer of 1 or more) or close to that value, with respect to the wavelength λ of the light whose intensity is to be enhanced.

[0194] It should be noted that the optical distance described above is, strictly speaking, related to the product of the physical distance between the reflective surface of the reflective layer and the reflective surface of the common electrode 113 which has both light transmission and reflectivity, and the refractive index of the layer provided between them, making it difficult to adjust precisely. Therefore, it is preferable to adjust the optical distance by assuming that the surface of the reflective layer and the surface of the common electrode 113 which has both light transmission and reflectivity are reflective surfaces, respectively.

[0195] [Example of manufacturing method] An example of a method for manufacturing a display device according to one aspect of the present invention will be described with reference to the drawings.

[0196] Thin films (insulating films, semiconductor films, conductive films, etc.) that constitute the display device can be formed using methods such as sputtering, chemical vapor deposition (CVD), vacuum deposition, pulsed laser deposition (PLD), and atomic layer deposition (ALD). CVD methods include plasma-enhanced CVD (PECVD) and thermal CVD. One type of thermal CVD is metal-organic vapor deposition (MOCVD).

[0197] Furthermore, thin films (insulating films, semiconductor films, conductive films, etc.) that constitute the display device can be formed by wet film deposition methods such as spin coating, dip coating, spray coating, inkjet printing, dispensing, screen printing, offset printing, doctor knife coating, slit coating, roll coating, curtain coating, or knife coating.

[0198] Furthermore, when processing the thin films that constitute the display device, photolithography or the like can be used. In addition, the thin films may be processed by nanoimprint lithography, sandblasting, lift-off lithography, or the like. Alternatively, island-shaped thin films may be directly formed by a film deposition method using a shielding mask such as a metal mask.

[0199] There are two main methods of photolithography. One method involves forming a resist mask on the thin film to be processed, then processing the thin film by etching or other means, and removing the resist mask. The other method involves forming a photosensitive thin film, then exposing and developing it to process the thin film into the desired shape.

[0200] In photolithography, the light used for exposure can be, for example, i-line (wavelength 365 nm), g-line (wavelength 436 nm), h-line (wavelength 405 nm), or a mixture thereof. Other options include ultraviolet light, KrF laser light, or ArF laser light. Exposure may also be performed using immersion lithography. Furthermore, extreme ultraviolet (EUV) light or X-rays may be used as the light source for exposure. An electron beam can also be used instead of the light source. Using extreme ultraviolet light, X-rays, or an electron beam is preferable because it allows for extremely fine processing. Note that a photomask is not required when exposure is performed by scanning a beam such as an electron beam.

[0201] Thin films can be processed using methods such as dry etching, wet etching, and sandblasting. The resist mask can be removed by dry etching (such as ashing), wet etching, wet etching after dry etching, or dry etching after wet etching.

[0202] For thin film planarization, polishing methods such as chemical mechanical polishing (CMP) are typically suitable. Other methods such as dry etching and plasma treatment may also be used. Polishing, dry etching, and plasma treatment may be performed multiple times, or they may be combined. When combining treatments, the order of the processes is not particularly limited and should be set appropriately according to the surface irregularities of the treated surface.

[0203] To precisely process a thin film to a desired thickness, for example, the CMP (Chemical Polishing) method can be used. In this method, the thin film is first polished at a constant processing speed until a portion of its upper surface is exposed. Then, by polishing at a slower processing speed until the thin film reaches the desired thickness, high-precision processing becomes possible.

[0204] Methods for detecting the end point of polishing include optical methods that involve irradiating the surface of the workpiece with light and detecting changes in the reflected light, physical methods that involve detecting changes in the polishing resistance that the processing equipment receives from the workpiece, and methods that involve applying magnetic field lines to the workpiece and using the changes in magnetic field lines caused by the resulting eddy currents.

[0205] After the upper surface of the thin film is exposed, the thickness of the thin film can be controlled with high precision by performing a polishing process at a slow processing speed while monitoring the thickness of the thin film using an optical method such as a laser interferometer. If necessary, the polishing process may be repeated multiple times until the thin film reaches the desired thickness.

[0206] {Preparation of substrate 101} As the substrate 101, a substrate having at least sufficient heat resistance to withstand subsequent heat treatment can be used. When an insulating substrate is used as the substrate 101, examples include glass substrates, quartz substrates, sapphire substrates, and ceramic substrates. In addition, semiconductor substrates such as single-crystal semiconductor substrates made of silicon or silicon carbide, polycrystalline semiconductor substrates, compound semiconductor substrates such as silicon germanium, and SOI substrates can be used.

[0207] In particular, it is preferable to use a substrate 101 on which a semiconductor circuit including semiconductor elements such as transistors is formed on the semiconductor substrate or the insulating substrate. It is preferable that the semiconductor circuit constitutes, for example, a pixel circuit, a gate line driving circuit (gate driver), a source line driving circuit (source driver), etc. In addition to the above, an arithmetic circuit, a memory circuit, etc. may also be configured.

[0208] In this embodiment, a substrate having at least a pixel circuit configured on it is used as the substrate 101.

[0209] {Formation of insulating layer 105, plug 131, and pixel electrode 111} An insulating film, which will become an insulating layer 105, is formed on the substrate 101.

[0210] {Formation of recess 175} Next, a recess 175 is formed in the insulating layer 105 (Figure 4A). An isotropic etching method can be used to form the recess 175. For example, isotropic plasma etching or wet etching can be used. In particular, when an insulating layer having an organic material is used as the insulating layer 105, it is preferable to use isotropic dry etching, plasma treatment, etc. As a plasma treatment, for example, RF plasma treatment using oxygen as the gas can be used. Also, when an insulating layer having an inorganic material is used as the insulating layer 105, it is preferable to use wet etching. This makes it possible to form a recess 175 that is partially located below the pixel electrode 111.

[0211] Furthermore, as shown in Figure 4A, when an insulating layer 106 is present on an insulating layer 105 and a pixel electrode 111 is formed on the insulating layer 106, it is preferable to use an organic insulating film as the insulating layer 105 and an inorganic insulating film as the insulating layer 106. With such a configuration, by using an isotropic dry etching process and etching conditions in which the etching rate of the organic insulating film is faster than that of the inorganic insulating film, a recess 175 located partially below the insulating layer 106 can be formed in the insulating layer 105.

[0212] Figure 4B shows a magnified view of the area enclosed by the dashed line in Figure 4A. Figure 4C shows an example of a pixel electrode 111 with a different shape from that shown in Figure 4B.

[0213] The pixel electrode 111 may be a single layer or a multilayer film. Figure 4C shows an example of a configuration when a multilayer film is used as the pixel electrode. The pixel electrode 111 shown in Figure 4C has a multilayer structure consisting of a conductive layer 111_1, a conductive layer 111_2 on conductive layer 111_1, and a conductive layer 111_3 on conductive layer 111_2. The edge of conductive layer 111_2 is located inward from the edges of conductive layer 111_1 and conductive layer 111_3. In addition, the side surface of conductive layer 111_2 is covered by conductive layer 111_3. This makes it possible to have a configuration in which conductive layer 111_2 and organic layer 112, or conductive layer 111_2 and PS layer 155S, do not come into contact.

[0214] Furthermore, by adopting the configuration shown in Figure 4C, oxidation of the conductive layer 111_2 in subsequent processes can be suppressed. In addition, even when the selectivity ratio between conductive layer 111_3 and conductive layer 111_2 is low during etching of conductive layer 111_3, recession of conductive layer 111_2 can be suppressed, enabling the display device to achieve excellent display quality.

[0215] Here, for example, a transparent conductive layer can be used as the conductive layer 111_3, and a reflective conductive layer can be used as the conductive layer 111_2.

[0216] {Formation of organic layer 112R and insulating layer 118a} A film containing the first light-emitting compound is formed on the pixel electrode 111R, the pixel electrode 111G, the pixel electrode 111B, and the insulating layer 105 (Figure 4D).

[0217] A film containing the first luminescent compound described above can be formed, for example, by a vapor deposition method, specifically a vacuum vapor deposition method. Alternatively, the film may be formed by methods such as a transfer method, a printing method, an inkjet method, or a coating method.

[0218] At this time, a step break occurs in the film containing the first luminescent compound within the recess 175. In Figure 4D, the step break occurs in the film at the protruding portion of the insulating layer 106. As a result, an organic layer 112Rf is formed on the pixel electrode 111R, on the pixel electrode 111G, on the pixel electrode 111B, and on the insulating layer 105.

[0219] Next, an insulating film 118A is deposited on the organic layer 112Rf and the insulating layer 105. The insulating film 118A can be deposited using sputtering, CVD, MBE, PLD, or ALD as appropriate.

[0220] The insulating film 118A is formed to cover the side surface of the organic layer 112R, the side surface of the pixel electrode 111R, and the side surface of the insulating layer 106. Furthermore, within the recess 175, the insulating film 118A is formed to cover the lower surface of the insulating layer 106. Furthermore, within the recess 175, the insulating film 118A is formed to cover the insulating layer 105 below the pixel electrode.

[0221] For example, the insulating film 118A can be a metallic material such as gold, silver, platinum, magnesium, nickel, tungsten, chromium, molybdenum, iron, cobalt, copper, palladium, titanium, aluminum, yttrium, zirconium, and tantalum, or an alloy material containing such a metallic material. In particular, it is preferable to use a low-melting-point material such as aluminum or silver. Using a metallic material capable of shielding ultraviolet light for the insulating film 118A is preferable because it can suppress irradiation of the EL layer with ultraviolet light and suppress the degradation of the EL layer.

[0222] Furthermore, metal oxides such as In-Ga-Zn oxide can be used for the insulating film 118A. For example, an In-Ga-Zn oxide film can be formed as the insulating film 118A using a sputtering method. In addition, indium oxide, In-Zn oxide, In-Sn oxide, indium titanium oxide (In-Ti oxide), indium tin zinc oxide (In-Sn-Zn oxide), indium titanium zinc oxide (In-Ti-Zn oxide), indium gallium tin zinc oxide (In-Ga-Sn-Zn oxide), etc. can be used. Alternatively, indium tin oxide containing silicon can also be used.

[0223] In addition, element M (where M is one or more selected from aluminum, silicon, boron, yttrium, copper, vanadium, beryllium, titanium, iron, nickel, germanium, zirconium, molybdenum, lanthanum, cerium, neodymium, hafnium, tantalum, tungsten, or magnesium) may be used instead of gallium. In particular, it is preferable that M be one or more selected from gallium, aluminum, or yttrium.

[0224] Furthermore, various inorganic insulating films that can be used in the protective layer 121 can be used as the insulating film 118A. Also, various inorganic insulating films that can be used in the insulating layer 125 can be used as the insulating film 118A. In particular, oxide insulating films are preferred because they have higher adhesion to the EL layer compared to nitride insulating films. For example, inorganic insulating materials such as aluminum oxide, hafnium oxide, and silicon oxide can be used as the insulating film 118A. For example, an aluminum oxide film can be formed as the insulating film 118A using the ALD method. Using the ALD method is preferable because it reduces damage to the substrate (especially the EL layer).

[0225] In this embodiment, aluminum oxide is deposited as the insulating film 118A by the ALD method. The insulating film 118A needs to be deposited with good coverage on the bottom and side surfaces of the recesses 175 provided in the insulating layer 105. Since the ALD method allows for the deposition of atomic layers one by one on the bottom and side surfaces of the recesses 175, the insulating film 118A can be deposited with good coverage on the recesses 175. In addition, film deposition damage can be reduced.

[0226] For example, when depositing aluminum oxide films using the ALD method, two types of gases are used: a raw material gas obtained by vaporizing a liquid containing a solvent and an aluminum precursor compound (such as trimethylaluminum (TMA, Al(CH3)3)), and H2O as an oxidizing agent. Other materials include tris(dimethylamide)aluminum, triisobutylaluminum, and aluminum tris(2,2,6,6-tetramethyl-3,5-heptanedionate).

[0227] Furthermore, the insulating film 118A may be deposited using a sputtering method, CVD method, or PECVD method, which have a faster deposition rate than the ALD method. This allows for the production of highly reliable display devices with high productivity.

[0228] Alternatively, the insulating film 118A may be arranged in a stacked structure of two or more layers.

[0229] For example, a two-layer structure can be used, where an inorganic insulating film (e.g., an aluminum oxide film) formed using the ALD method is used as the lower layer, and an inorganic film (e.g., an In-Ga-Zn oxide film, an aluminum film, or a tungsten film) formed using the sputtering method is used as the upper layer.

[0230] Next, a resist mask 181 is formed on the insulating film 118A (Figure 4E). At this time, the resist mask 181 is formed in a portion that overlaps with the organic layer 112R and a part of the recess 175.

[0231] In Figure 4E, the edges of the resist mask 181 are perpendicular to the surface of the substrate 101, but the shape of the edges of the resist mask 181 is not limited to this. The edges of the resist mask 181 may have a tapered shape or an inverse tapered shape.

[0232] Next, the insulating film 118A that is not covered by the resist mask 181 can be removed to form the insulating layer 118a. A dry etching method or a wet etching method can be used to remove a portion of the insulating film 118A.

[0233] After that, remove the resist mask 181.

[0234] Next, an etching process using the insulating layer 118a as a hard mask removes a portion of the organic layer 112Rf, forming the organic layer 112R (Figure 5A). As a result, a stacked structure of the organic layer 112R and the insulating layer 118a remains on the pixel electrode 111R.

[0235] In Figure 5A, the organic layer 112Rf in the portion that does not overlap with the resist mask 181 has been removed. However, since the organic layer 112Rf in that portion is separated from the organic layer 112R, it is acceptable for that portion of the organic layer 112Rf to remain. Furthermore, the organic layer 112Rf that is in contact with the insulating layer 105 and formed on the recess 175 may also remain.

[0236] As described above, the insulating layer 106 and the insulating layer 118a can seal the organic layer 112R and the pixel electrode 111R.

[0237] {Formation of organic layer 112G and insulating layer 118b} A film containing a second light-emitting compound is formed on the pixel electrode 111G, the pixel electrode 111B, the insulating layer 105, and the insulating layer 118a.

[0238] The film containing the second luminescent compound described above can be formed, for example, by a vapor deposition method, specifically a vacuum vapor deposition method. Alternatively, the film may be formed by methods such as a transfer method, a printing method, an inkjet method, or a coating method.

[0239] At this time, a step break occurs in the film containing the second luminescent compound within the recess 175. As a result, an organic layer 112Gf is formed on the pixel electrode 111G, the pixel electrode 111B, the insulating layer 105, and the insulating layer 118a.

[0240] Next, an insulating film 118B is deposited on the organic layer 112Gf and the insulating layer 105 (Figure 5B). The insulating film 118B can be deposited using sputtering, CVD, MBE, PLD, or ALD as appropriate. For details on insulating film 118B, refer to the description of insulating film 118A.

[0241] Next, a resist mask 182 is formed on the insulating film 118B (Figure 5C).

[0242] Next, the insulating film 118B that is not covered by the resist mask 182 can be removed to form the insulating layer 118b. A dry etching method or a wet etching method can be used to remove a portion of the insulating film 118B.

[0243] After that, remove the resist mask 182.

[0244] Next, an etching process using the insulating layer 118b as a hard mask removes a portion of the organic layer 112Gf, forming the organic layer 112G (Figure 5D). As a result, a stacked structure of the organic layer 112G and the insulating layer 118b remains on the pixel electrode 111G.

[0245] As described above, the insulating layer 106 and the insulating layer 118b can seal the organic layer 112G and the pixel electrode 111G.

[0246] {Formation of organic layer 112B, insulating layer 118c, PS layer 155S, and insulating layer 118d} Referring to the formation process of organic layer 112R and organic layer 112G, a laminated structure of organic layer 112B and insulating layer 118c is formed on the pixel electrode 111B (Figure 6A). Also, although not shown, a laminated structure of PS layer 155S and insulating layer 118d is formed on the pixel electrode 111S.

[0247] The insulating layer 106 and insulating layer 118c can seal the organic layer 112B and the pixel electrode 111B. In addition, the insulating layer 106 and insulating layer 118d can seal the PS layer 155S and the pixel electrode 111S.

[0248] Figure 6B shows a magnified view of the area enclosed by the dashed line in Figure 6A. Figure 6C shows an example of a configuration different from that of Figure 6B.

[0249] As shown in Figure 6C, the thickness of the organic layer 112 may be thinner in the region in contact with the side surface of the pixel electrode 111 and the region in contact with the side surface of the recess 175 compared to the thickness of the region in contact with the upper surface of the pixel electrode 111. Similarly, in the PS layer 155S, the thickness may be thinner in the region in contact with the side surface of the pixel electrode 111 and the region in contact with the side surface of the recess 175 compared to the thickness of the region in contact with the upper surface of the pixel electrode 111. In addition, steps may be formed in the insulating layer 105 during the formation process of the organic layer 112G, etc. Specifically, for example, as shown in Figure 6C, steps may be formed near the edge of the insulating layer 118a.

[0250] {Formation of insulating layer 125, resin layer 126, common layer 114, and common electrode 113} Next, insulating film 125A is formed on insulating layer 105, insulating layer 118a, insulating layer 118b, and insulating layer 118c, and resin film 126A is formed on insulating film 125A (Figure 7A). Insulating film 125A is the film that will become insulating layer 125, and resin film 126A is the film that will become resin layer 126. Note that if a two-layer laminated structure is used as the insulating layer 118, the upper layer may be removed before forming insulating film 125A and resin film 126A.

[0251] A film that can be used as the insulating film 118A, etc., can be used as the insulating film 125A. Furthermore, the insulating film 125A may be omitted.

[0252] The resin film 126A is formed at a temperature lower than the heat resistance temperature of the organic layer 112R, organic layer 112G, organic layer 112B, and PS layer 155S. The substrate temperature when forming the insulating film is preferably 60°C or higher, 80°C or higher, 100°C or higher, or 120°C or higher, and 200°C or lower, 180°C or lower, 160°C or lower, 150°C or lower, or 140°C or lower.

[0253] Furthermore, the resin film 126A is preferably formed using the wet film formation method described above. The insulating film is preferably formed using a photosensitive material, for example, by spin coating, and more specifically, it is preferably formed using a photosensitive resin composition containing an acrylic resin.

[0254] The resin film 126A is preferably formed using a resin composition having, for example, a polymer, an acid generator, and a solvent. The polymer is formed using one or more monomers and has a structure in which one or more structural units (also called constituent units) are repeated regularly or irregularly. As the acid generator, one or both of the following can be used: a compound that generates acid upon irradiation with light, and a compound that generates acid upon heating. The resin composition may further contain one or more of the following: a photosensitive agent, a sensitizer, a catalyst, an adhesion aid, a surfactant, and an antioxidant.

[0255] Furthermore, it is preferable to perform a heat treatment (also called pre-baking) after the formation of the resin film 126A. This heat treatment is performed at a temperature lower than the heat resistance temperature of the organic layer 112R, organic layer 112G, and organic layer 112B. The substrate temperature during the heat treatment is preferably 50°C to 200°C, more preferably 60°C to 150°C, and even more preferably 70°C to 120°C. This allows for the removal of solvent contained in the resin film 126A.

[0256] Next, exposure is performed to expose a portion of the resin film 126A to visible light or ultraviolet light. Here, if a positive-type photosensitive resin composition containing acrylic resin is used for the insulating film, visible light or ultraviolet light is irradiated to the area where the resin layer 126 will not be formed in a later step. The resin layer 126 is formed in the area sandwiched between any two of the pixel electrodes 111R, 111G, and 111B. Therefore, visible light or ultraviolet light is irradiated onto the pixel electrode 111. If a negative-type photosensitive material is used for the resin film, visible light or ultraviolet light is irradiated to the area where the resin layer 126 is formed.

[0257] The width of the resin layer 126 to be formed later can be controlled by the exposure area on the resin film 126A. In the present embodiment, processing is performed such that the resin layer 126 has an area overlapping with the upper surface of the pixel electrode 111.

[0258] The light used for exposure preferably includes i-line (wavelength 365 nm). Further, the light used for exposure may include at least one of g-line (wavelength 436 nm) and h-line (wavelength 405 nm).

[0259] Subsequently, development is performed to remove the exposed area of the resin film 126A and form the resin layer 126. The resin layer 126 is formed in an area sandwiched between any two of the pixel electrodes 111R, pixel electrode 111G, and pixel electrode 111B. Here, when an acrylic resin is used for the insulating film, it is preferable to use an alkaline solution as the developer, for example, an aqueous solution of tetramethylammonium hydroxide (TMAH) can be used.

[0260] Subsequently, residues (so-called scum) during development may be removed. For example, the residues can be removed by performing ashing using oxygen plasma.

[0261] Note that etching may be performed to adjust the height of the surface of the resin layer 126. The resin layer 126 may be processed by, for example, ashing using oxygen plasma. Also, even when a non-photosensitive material is used as the resin film that becomes the resin layer 126, for example, the height of the surface of the insulating film can be adjusted by the ashing.

[0262] Subsequently, an etching process is performed using the resin layer 126 as a mask to remove a part of the insulating film 125A, a part of the insulating layer 118a, a part of the insulating layer 118b, and a part of the insulating layer 118c. As a result, openings are formed in the insulating film 125A and the insulating layer 118a, and the upper surface of the organic layer 112R is exposed. Also, openings are formed in the insulating film 125A and the insulating layer 118b, and the upper surface of the organic layer 112G is exposed. Further, openings are formed in the insulating film 125A and the insulating layer 118c, and the upper surface of the organic layer 112B is exposed (FIG. 7B). Although not shown, openings are formed in the insulating film 125A and the insulating layer 118d, and the upper surface of the PS layer 155S is exposed. In other words, openings reaching the organic layer 112R are provided in the resin layer 126, the insulating layer 125, and the insulating layer 118a. Also, openings reaching the organic layer 112G are provided in the resin layer 126, the insulating layer 125, and the insulating layer 118b. Further, openings reaching the organic layer 112B are provided in the resin layer 126, the insulating layer 125, and the insulating layer 118c. Also, openings reaching the PS layer 155S are provided in the resin layer 126, the insulating layer 125, and the insulating layer 118d.

[0263] The above etching process is performed by wet etching. By using the wet etching method, the damage applied to the organic layer 112R, the organic layer 112G, and the organic layer 112B can be reduced as compared with the case of using the dry etching method. The chemical solution used for the wet etching process may be alkaline or acidic. For example, wet etching using an alkaline solution such as TMAH can be performed. Alternatively, wet etching using an acidic solution such as dilute hydrofluoric acid, oxalic acid, phosphoric acid, acetic acid, nitric acid, or a mixed liquid thereof may be used. Also, in the case of wet etching using an acidic solution, a mixed acid-based chemical solution containing water, phosphoric acid, dilute hydrofluoric acid, and nitric acid may be used.

[0264] Furthermore, after exposing a portion of the organic layer 112R, organic layer 112G, organic layer 112B, and PS layer 155S, a further heat treatment may be performed. This heat treatment can remove water contained in the organic layer 112 and PS layer 155S, as well as water adsorbed on the surfaces of the organic layer 112 and PS layer 155S. For example, the heat treatment can be performed in an inert gas atmosphere or a reduced pressure atmosphere. The heat treatment can be performed at a substrate temperature of 50°C to 200°C, preferably 60°C to 150°C, and more preferably 70°C to 120°C. A reduced pressure atmosphere is preferable because it allows for dehydration at a lower temperature. However, it is preferable to appropriately set the temperature range for the above heat treatment, taking into account the heat resistance temperatures of the organic layer 112 and PS layer 155S. When considering the heat resistance temperatures of the organic layer 112 and PS layer 155S, a temperature of 70°C to 120°C is particularly preferred within the above temperature range.

[0265] Next, a common layer 114 is formed on the organic layer 112R, the organic layer 112G, the organic layer 112B, the PS layer 155S, and the resin layer 126. The common layer 114 can be formed by methods such as vapor deposition (including vacuum deposition), transfer, printing, inkjet, or coating.

[0266] Next, a common electrode 113 is formed on the common layer 114. The common electrode 113 can be formed using sputtering or vacuum deposition. Alternatively, the common electrode 113 may be formed by laminating a film formed by deposition and a film formed by sputtering.

[0267] The common electrode 113 is formed to overlap with the organic layer 112R through openings formed in the resin layer 126 and the insulating layer 118a. The common electrode 113 is also formed to overlap with the organic layer 112G through openings formed in the resin layer 126 and the insulating layer 118b. The common electrode 113 is also formed to overlap with the organic layer 112B through openings formed in the resin layer 126 and the insulating layer 118c. The common electrode 113 is also formed to overlap with the PS layer 155S through openings formed in the resin layer 126 and the insulating layer 118d.

[0268] As a result, the light-emitting element 110R, light-emitting element 110G, light-emitting element 110B, and light-receiving element 110S can be formed.

[0269] Next, a protective layer 121 is formed on the common electrode 113 (Figure 7C). The protective layer 121 can be formed by methods such as vacuum deposition, sputtering, CVD, or ALD.

[0270] Based on the above, a display device 100A having the configuration shown in Figure 2A, etc., can be manufactured.

[0271] According to the above example of the manufacturing method, the organic layer 112 and the PS layer 155S are sealed with the insulating layer 106 and the insulating layer 118, or the insulating layer 105 and the insulating layer 118, and are therefore not exposed to the chemicals used when removing the resist mask. Thus, the light-emitting element 110 can be formed without using a metal mask for the deposition of the organic layer 112 and the PS layer 155S.

[0272] According to the above example of manufacturing method, since the wet etching method can be used for all etching processes performed after the formation of the pixel electrodes 111, it is possible to reduce the manufacturing cost of the display device 100A.

[0273] According to the above example of manufacturing method, the difference in optical distance between the pixel electrode 111 and the common electrode 113 can be precisely controlled by the thickness of the organic layer 112. As a result, color shifts in each light-emitting element are less likely to occur, and a display device with excellent color reproduction and extremely high display quality can be easily manufactured.

[0274] Furthermore, by providing a resin layer 126 having a tapered shape at its end between adjacent island-shaped organic layers 112, adjacent organic layers 112 and PS layer 155S, etc., it is possible to suppress the occurrence of step breaks during the formation of the common electrode 113, and to suppress the formation of locally thin areas in the common electrode 113. As a result, it is possible to suppress connection failures caused by the divided areas and increases in electrical resistance caused by locally thin areas in the common layer 114 and the common electrode 113. Therefore, a display device according to one aspect of the present invention can achieve high resolution, high display quality, and high light reception sensitivity.

[0275] In addition, in one embodiment of the present invention, the aspect ratio of the display unit of the display device is not particularly limited. For example, the display device can accommodate various aspect ratios such as 1:1 (square), 3:4, 16:9, and 16:10.

[0276] [Pixel layout] The following section primarily describes pixel layouts different from those shown in Figure 1. There are no particular limitations on the arrangement of subpixels, and various methods can be applied. Examples of subpixel arrangements include stripe arrangements, S-stripe arrangements, matrix arrangements, delta arrangements, Bayer arrangements, and pentile arrangements.

[0277] The top surface shape of the subpixels shown in Figures 8 and 9 corresponds to the top surface shape of the light-emitting region.

[0278] The top surface shape of the subpixel may include, for example, polygons such as triangles, quadrilaterals (including rectangles and squares), pentagons, polygons with rounded corners, ellipses, or circles.

[0279] Also, the circuit layout constituting the sub-pixels is not limited to the range of the sub-pixels shown in the figure, and may be arranged outside thereof.

[0280] An S stripe array is applied to the pixel 150 shown in FIG. 8A. The pixel 150 shown in FIG. 8A is composed of three sub-pixels: a sub-pixel 130a, a sub-pixel 130b, and a sub-pixel 130c. For example, the sub-pixel 130a can be a sub-pixel having a light-emitting element 110R. Also, for example, the sub-pixel 130b can be a sub-pixel having a light-emitting element 110G. Also, for example, the sub-pixel 130c can be a sub-pixel having a light-emitting element 110B.

[0281] The pixel 150 shown in FIG. 8B has a sub-pixel 130a having a substantially trapezoidal upper surface shape with rounded corners, a sub-pixel 130b having a substantially triangular upper surface shape with rounded corners, and a sub-pixel 130c having a substantially rectangular or substantially hexagonal upper surface shape with rounded corners. Also, the sub-pixel 130a has a larger light-emitting area than the sub-pixel 130b. Thus, the shape and size of each sub-pixel can be determined independently. For example, a sub-pixel having a highly reliable light-emitting element can have a smaller size.

[0282] A pentile array is applied to the pixels 124a and 124b shown in FIG. 8C. FIG. 8C shows an example in which pixels 124a having sub-pixels 130a and 130b and pixels 124b having sub-pixels 130b and 130c are alternately arranged.

[0283] The pixels 124a and 124b shown in FIGS. 8D to 8F have a delta array applied thereto. The pixel 124a has two sub-pixels (sub-pixel 130a, sub-pixel 130b) in the upper row (the first row) and one sub-pixel (sub-pixel 130c) in the lower row (the second row). The pixel 124b has one sub-pixel (sub-pixel 130c) in the upper row (the first row) and two sub-pixels (sub-pixel 130a, sub-pixel 130b) in the lower row (the second row).

[0284] Figure 8D shows an example where each subpixel has a roughly square top shape with rounded corners, Figure 8E shows an example where each subpixel has a circular top shape, and Figure 8F shows an example where each subpixel has a roughly hexagonal top shape with rounded corners.

[0285] In Figure 8F, each subpixel is located inside a densely packed hexagonal region. When focusing on a single subpixel, it is arranged so that it is surrounded by six other subpixels. Furthermore, subpixels that emit light of the same color are not adjacent to each other. For example, when focusing on subpixel 130a, three subpixels 130b and three subpixels 130c are arranged alternately around it.

[0286] Figure 8G shows an example where the subpixels of each color are arranged in a zigzag pattern. Specifically, in a top view, the upper edges of two subpixels aligned in the column direction (for example, subpixels 130a and 130b, or subpixels 130b and 130c) are offset.

[0287] In each pixel shown in Figures 8A to 8G, it is preferable, for example, that sub-pixel 130a emits red light, sub-pixel 130b emits green light, and sub-pixel 130c emits blue light. However, the configuration of the sub-pixels is not limited to this, and the colors emitted by the sub-pixels and their order can be determined as appropriate. For example, sub-pixel 130b may emit red light and sub-pixel 130a may emit green light.

[0288] In photolithography, the finer the pattern being processed, the more significant the effects of light diffraction become. This compromises the fidelity of the transfer of the photomask pattern through exposure, making it difficult to process the resist mask into the desired shape. Therefore, even if the photomask pattern is rectangular, patterns with rounded corners are likely to be formed. Consequently, the top surface shape of subpixels may be a polygon with rounded corners, an ellipse, or a circle.

[0289] Furthermore, in a method for manufacturing a display device according to one aspect of the present invention, the EL layer is processed into an island shape using a resist mask. The resist film formed on the EL layer needs to be cured at a temperature lower than the heat resistance temperature of the EL layer. Therefore, depending on the heat resistance temperature of the EL layer material and the curing temperature of the resist material, the curing of the resist film may be insufficient. A resist film that is not sufficiently cured may take a shape that deviates from the desired shape during processing. As a result, the top surface shape of the EL layer may become a polygon with rounded corners, an ellipse, or a circle. For example, if an attempt is made to form a resist mask with a square top surface, a resist mask with a circular top surface may be formed, resulting in a circular top surface shape for the EL layer.

[0290] Furthermore, in order to achieve the desired shape of the upper surface of the EL layer, a technique (OPC (Optical Proximity Correction) technique) may be used to pre-correct the mask pattern so that the design pattern and the transferred pattern match. Specifically, in the OPC technique, a correction pattern is added to the corners of the shape on the mask pattern.

[0291] As shown in Figures 9A to 9I, a pixel can be configured to have four types of subpixels. For example, a pixel can be composed of four subpixels: subpixel 130a, subpixel 130b, subpixel 130c, and subpixel 130d. Subpixel 130a can be, for example, a subpixel having a light-emitting element 110R. Subpixel 130b can be, for example, a subpixel having a light-emitting element 110G. Subpixel 130c can be, for example, a subpixel having a light-emitting element 110B. Subpixel 130d can be, for example, a subpixel having a light-receiving element 110S.

[0292] Pixel 150, shown in Figures 9A to 9C, has a stripe arrangement applied to it.

[0293] Figure 9A shows an example where each subpixel has a rectangular top surface shape, Figure 9B shows an example where each subpixel has a top surface shape formed by connecting two semicircles and a rectangle, and Figure 9C shows an example where each subpixel has an elliptical top surface shape.

[0294] Pixel 150, shown in Figures 9D to 9F, has a matrix array applied to it.

[0295] Figure 9D shows an example where each subpixel has a square top surface shape, Figure 9E shows an example where each subpixel has a roughly square top surface shape with rounded corners, and Figure 9F shows an example where each subpixel has a circular top surface shape.

[0296] Figures 9G and 9H show an example where one pixel 150 is composed of 2 rows and 3 columns.

[0297] Pixel 150, shown in Figure 9G, has three subpixels (subpixels 130a, 130b, and 130c) in the top row (row 1) and one subpixel (subpixel 130d) in the bottom row (row 2). In other words, pixel 150 has subpixel 130a in the left column (column 1), subpixel 130b in the middle column (column 2), subpixel 130c in the right column (column 3), and subpixel 130d across these three columns.

[0298] Pixel 150, shown in Figure 9H, has three subpixels (subpixels 130a, 130b, and 130c) in the top row (1st row) and three subpixels 130d in the bottom row (2nd row). In other words, pixel 150 has subpixels 130a and 130d in the left column (1st column), subpixels 130b and 130d in the middle column (2nd column), and subpixels 130c and 130d in the right column (3rd column). As shown in Figure 9H, by aligning the arrangement of subpixels in the top row and bottom row, it becomes possible to efficiently remove dust and other debris that may occur during the manufacturing process. Therefore, a display device with high display quality can be provided.

[0299] Figure 9I shows an example where one pixel, 150, is composed of 3 rows and 2 columns.

[0300] Pixel 150, shown in Figure 9I, has a sub-pixel 130a in the top row (1st row), a sub-pixel 130b in the middle row (2nd row), a sub-pixel 130c spanning from the 1st to the 2nd row, and one sub-pixel (sub-pixel 130d) in the bottom row (3rd row). In other words, pixel 150 has sub-pixels 130a and 130b in the left column (1st column), a sub-pixel 130c in the right column (2nd column), and a sub-pixel 130d spanning these two columns.

[0301] Pixel 150, shown in Figures 9A to 9I, is composed of four subpixels: subpixel 130a, subpixel 130b, subpixel 130c, and subpixel 130d.

[0302] Sub-pixels 130a, 130b, and 130c can each be configured to have light-emitting elements that emit light of different colors, and sub-pixel 130d can be configured to have a light-receiving element.

[0303] In each pixel 150 shown in Figures 9A to 9I, it is preferable, for example, that sub-pixel 130a emits red light, sub-pixel 130b emits green light, sub-pixel 130c emits blue light, and sub-pixel 130d has the function of detecting either visible light or infrared light, or both. With such a configuration, in the pixel 150 shown in Figures 9G and 9H, the layout of the R, G, and B sub-pixels becomes a stripe arrangement, which can improve the display quality. Also, in the pixel 150 shown in Figure 9I, the layout of the R, G, and B sub-pixels becomes a so-called S-stripe arrangement, which can improve the display quality.

[0304] Alternatively, the sub-pixels 130a, 130b, 130c, and 130d may each be configured to have light-emitting elements that emit light of different colors. For example, if the sub-pixels 130a, 130b, 130c, and 130d each have light-emitting elements that emit light of different colors, examples include sub-pixels of four colors: R, G, B, and white (W); sub-pixels of four colors: R, G, B, and Y; or sub-pixels of R, G, B, and infrared (IR).

[0305] In each pixel 150 shown in Figures 9A to 9I, it is preferable, for example, that sub-pixel 130a emits red light, sub-pixel 130b emits green light, sub-pixel 130c emits blue light, and sub-pixel 130d emits either white light, yellow light, or near-infrared light. With such a configuration, in the pixel 150 shown in Figures 9G and 9H, the layout of the R, G, and B sub-pixels becomes a stripe arrangement, thereby improving the display quality. In addition, in the pixel 150 shown in Figure 9I, the layout of the R, G, and B sub-pixels becomes a so-called S-stripe arrangement, thereby improving the display quality.

[0306] As described above, in one aspect of the present invention, various layouts can be applied to pixels that consist of subpixels having light-emitting elements.

[0307] This embodiment can be combined with other embodiments as appropriate.

[0308] (Embodiment 2) This embodiment describes other configuration examples of the display device (display panel) described in the previous embodiment. The display device (display panel) exemplified below can be applied to the display device 100A of Embodiment 1 above. The display device (display panel) exemplified below has a transistor.

[0309] The display device of this embodiment can be a high-definition display device. For example, a display device according to one aspect of the present invention can be used as a display unit for information terminals (wearable devices) such as wristwatches and bracelets, and as a display unit for wearable devices that can be worn on the head, such as VR devices such as head-mounted displays and AR devices such as glasses.

[0310] [Display Module] Figure 10A shows a perspective view of the display module 280. The display module 280 includes a display device 200A and an FPC 290. Note that the display panel of the display module 280 is not limited to the display device 200A, but may be any of the display devices 200B to 200F described later.

[0311] The display module 280 has substrates 291 and 292. The display module 280 has a display unit 281. The display unit 281 is an area for displaying an image.

[0312] Figure 10B shows a schematic perspective view illustrating the configuration of the substrate 291. On the substrate 291, a circuit section 282, a pixel circuit section 283 on the circuit section 282, and a pixel section 284 on the pixel circuit section 283 are stacked. In addition, a terminal section 285 for connecting to the FPC 290 is provided in the portion of the substrate 291 that does not overlap with the pixel section 284. The terminal section 285 and the circuit section 282 are electrically connected by a wiring section 286, which is composed of multiple wires.

[0313] The pixel section 284 has a plurality of pixels 284a arranged periodically. A magnified view of one pixel 284a is shown on the right side of Figure 10B. The pixel 284a has a light-emitting element 110R that emits red light, a light-emitting element 110G that emits green light, a light-emitting element 110B that emits blue light, and a light-receiving element 110S.

[0314] The pixel circuit section 283 has a plurality of periodically arranged pixel circuits 283a. Each pixel circuit 283a is a circuit that controls the light emission of the light-emitting element and light-receiving element of one pixel 284a. A single pixel circuit 283a may be configured to have four circuits that control the light emission of one light-emitting element (light-receiving element). For example, each pixel circuit 283a can be configured to have at least one selection transistor, one current control transistor (drive transistor), and a capacitive element for each light-emitting element. In this case, a gate signal is input to the gate of the selection transistor, and a source signal is input to the source. This realizes an active matrix type display panel.

[0315] The circuit section 282 has circuits for driving each pixel circuit 283a of the pixel circuit section 283. For example, it is preferable to have one or both of a gate line drive circuit and a source line drive circuit. In addition, it may have at least one of the following: an arithmetic circuit, a memory circuit, and a power supply circuit. Furthermore, transistors provided in the circuit section 282 may constitute a part of the pixel circuit 283a. That is, the pixel circuit 283a may be composed of transistors in the pixel circuit section 283 and transistors in the circuit section 282.

[0316] The FPC290 functions as wiring for supplying video signals and power potential to the circuit section 282 from an external source. An IC may also be mounted on the FPC290.

[0317] The display module 280 can be configured such that one or both of the pixel circuit section 283 and the circuit section 282 are stacked on the lower side of the pixel section 284, thereby enabling an extremely high aperture ratio (effective display area ratio) of the display section 281. For example, the aperture ratio of the display section 281 can be 40% or more and less than 100%, preferably 50% or more and 95%, and more preferably 60% or more and 95%. Furthermore, it is possible to arrange the pixels 284a at an extremely high density, enabling an extremely high resolution of the display section 281. For example, it is preferable that the pixels 284a in the display section 281 are arranged with a resolution of 20000 ppi or more, preferably 3000 ppi or more, more preferably 5000 ppi or more, and even more preferably 6000 ppi or more, and with a resolution of 20000 ppi or less, or 30000 ppi or less.

[0318] Because such a display module 280 is extremely high-resolution, it can be suitably used in VR devices such as head-mounted displays, or in glasses-type AR devices. For example, even in a configuration where the display part of the display module 280 is viewed through lenses, the display module 280 has an extremely high-resolution display part 281, so even when the display part is magnified with lenses, pixels are not visible, allowing for a highly immersive display. Furthermore, the display module 280 is not limited to this, and can be suitably used in electronic devices with relatively small display parts. For example, it can be suitably used in the display part of wearable electronic devices such as wristwatches.

[0319] [Display device 200A] The display device 200A shown in Figure 11 includes a substrate 301, light-emitting elements 110R, 110G, 110B (not shown), a light-receiving element 110S, a capacitor 240, and a transistor 310.

[0320] Substrate 301 corresponds to substrate 291 in Figures 10A and 10B.

[0321] The transistor 310 is a transistor having a channel-forming region in the substrate 301. The substrate 301 can be a semiconductor substrate such as a single-crystal silicon substrate. The transistor 310 comprises a portion of the substrate 301, a conductive layer 311, a low-resistance region 312, an insulating layer 313, and an insulating layer 314. The conductive layer 311 functions as a gate electrode. The insulating layer 313 is located between the substrate 301 and the conductive layer 311 and functions as a gate insulating layer. The low-resistance region 312 is a region of the substrate 301 doped with impurities and functions as either a source or a drain. The insulating layer 314 is provided covering the side surface of the conductive layer 311.

[0322] Furthermore, an element isolation layer 315 is provided between two adjacent transistors 310 so as to be embedded in the substrate 301.

[0323] Furthermore, an insulating layer 261 is provided covering the transistor 310, and a capacitance 240 is provided on the insulating layer 261.

[0324] The capacitor 240 has a conductive layer 241, a conductive layer 245, and an insulating layer 243 located between them. The conductive layer 241 acts as one electrode of the capacitor 240, the conductive layer 245 acts as the other electrode of the capacitor 240, and the insulating layer 243 acts as the dielectric of the capacitor 240.

[0325] The conductive layer 241 is provided on the insulating layer 261 and embedded in the insulating layer 254. The conductive layer 241 is electrically connected to either the source or drain of the transistor 310 by a plug 271 embedded in the insulating layer 261. The insulating layer 243 is provided covering the conductive layer 241. The conductive layer 245 is provided in the region that overlaps with the conductive layer 241 via the insulating layer 243.

[0326] An insulating layer 255 is provided covering the capacitance 240.

[0327] An inorganic insulating film can preferably be used for the insulating layer 255. For example, a silicon oxide film or a silicon nitride film can be used as the insulating layer 255. In this embodiment, an example is shown in which a part of the insulating layer 255 is etched to form a recess.

[0328] The insulating layer 255 may have a three-layer laminated structure comprising a first insulating layer, a second insulating layer on the first insulating layer, and a third insulating layer on the second insulating layer. Inorganic insulating films can preferably be used for the first, second, and third insulating layers. For example, it is preferable to use silicon oxide films for the first and third insulating layers and silicon nitride films for the second insulating layer. This allows the second insulating layer to function as an etching protective film.

[0329] The insulating layer 255 corresponds to the insulating layer 105 in Figure 2A, etc. Furthermore, if the insulating layer 255 has a laminated structure, some of the multiple layers of the insulating layer 255 correspond to the insulating layer 105 in Figure 2A, etc.

[0330] A light-emitting element 110R, a light-emitting element 110G, and a light-receiving element 110S are provided on the insulating layer 255. The configuration of the light-emitting element 110R, the light-emitting element 110G, and the light-receiving element 110S can be adapted from Embodiment 1. The light-emitting element 110R is, for example, a light-emitting element that emits red light R. The light-emitting element 110G is, for example, a light-emitting element that emits green light G. The light-receiving element 110S is, for example, a light-emitting element that has the function of detecting light L.

[0331] The display device 200A has different light-emitting elements for each emission color, resulting in minimal change in chromaticity between low-brightness and high-brightness emission. Furthermore, because the organic layers 112R, 112G, and 112B are separated, crosstalk between adjacent sub-pixels can be suppressed even in high-resolution display panels. Therefore, a display panel with high resolution and high display quality can be realized.

[0332] An insulating layer 118 and a resin layer 126 are provided in the region between adjacent light-emitting elements.

[0333] The pixel electrodes 111R, 111G, and 111S of the light-emitting element are electrically connected to either the source or drain of the transistor 310 by plugs 256 embedded in the insulating layer 255, a conductive layer 241 embedded in the insulating layer 254, and plugs 271 embedded in the insulating layer 261. The height of the upper surface of the insulating layer 255 and the height of the upper surface of the plugs 256 are equal or approximately equal. Various conductive materials can be used for the plugs.

[0334] Furthermore, a protective layer 121 is provided on the light-emitting element 110R, the light-emitting element 110G, and the light-receiving element 110S. The substrate 170 is bonded to the protective layer 121 by an adhesive layer 171. For example, a resin layer can be used as the adhesive layer 171. Examples of resin layers that can be used for the adhesive layer 171 include various curing adhesives such as UV-curing adhesives, reaction-curing adhesives, thermosetting adhesives, and anaerobic adhesives. Examples of these adhesives include epoxy resin, acrylic resin, silicone resin, phenolic resin, polyimide resin, imide resin, PVC (polyvinyl chloride) resin, PVB (polyvinyl butyral) resin, and EVA (ethylene vinyl acetate) resin. Materials with low moisture permeability, such as epoxy resin, are particularly preferred. A two-component mixed resin may also be used. An adhesive sheet may also be used.

[0335] There is no insulating layer covering the upper edge of the pixel electrode 111 between two adjacent pixel electrodes 111. Therefore, the spacing between adjacent light-emitting elements can be made extremely narrow. Consequently, a high-definition or high-resolution display device can be made.

[0336] [Display device 200B] The display device 200B shown in Figure 12 has a configuration in which transistors 310A and 310B, each with a channel formed on a semiconductor substrate, are stacked. In the following description of the display panel, parts that are the same as those described earlier may be omitted.

[0337] The display device 200B has a configuration in which a substrate 301B on which a transistor 310B, a capacitor 240, and a light-emitting element are provided, and a substrate 301A on which a transistor 310A is provided are bonded together.

[0338] Here, an insulating layer 345 is provided on the underside of substrate 301B, and an insulating layer 346 is provided on top of the insulating layer 261 provided on substrate 301A. Insulating layers 345 and 346 are insulating layers that function as protective layers and can suppress the diffusion of impurities into substrates 301B and 301A. As insulating layers 345 and 346, inorganic insulating films that can be used for protective layer 121 or insulating layer 332 can be used.

[0339] A plug 343 is provided on the substrate 301B, which penetrates both the substrate 301B and the insulating layer 345. Here, it is preferable to provide an insulating layer 344 that covers the sides of the plug 343 and functions as a protective layer.

[0340] Furthermore, the substrate 301B has a conductive layer 342 provided beneath the insulating layer 345. The conductive layer 342 is embedded in the insulating layer 335, and the undersides of the conductive layer 342 and the insulating layer 335 are flattened. The conductive layer 342 is also electrically connected to the plug 343.

[0341] On the other hand, the substrate 301A has a conductive layer 341 on top of an insulating layer 346. The conductive layer 341 is embedded in the insulating layer 336, and the upper surfaces of the conductive layer 341 and the insulating layer 336 are flattened.

[0342] It is preferable to use the same conductive material for conductive layer 341 and conductive layer 342. For example, a metal film containing an element selected from Al, Cr, Cu, Ta, Ti, Mo, and W, or a metal nitride film (titanium nitride film, molybdenum nitride film, tungsten nitride film) composed of the above elements can be used. In particular, it is preferable to use copper for conductive layer 341 and conductive layer 342. This makes it possible to apply Cu-Cu (copper-copper) direct bonding technology (a technology that achieves electrical conductivity by connecting Cu (copper) pads to each other).

[0343] [Display device 200C] The display device 200C shown in Figure 13 has a configuration in which conductive layer 341 and conductive layer 342 are joined via bumps 347.

[0344] As shown in Figure 13, the conductive layer 341 and the conductive layer 342 can be electrically connected by providing a bump 347 between them. The bump 347 can be formed using a conductive material containing, for example, gold (Au), nickel (Ni), indium (In), or tin (Sn). Solder may also be used as the bump 347. An adhesive layer 348 may also be provided between the insulating layer 345 and the insulating layer 346. Furthermore, when the bump 347 is provided, the insulating layer 345 and the insulating layer 346 may be omitted.

[0345] [Display device 200D] The display device 200D shown in Figure 14 differs from the display device 200A mainly in its transistor configuration.

[0346] Transistor 320 is an OS transistor in which a metal oxide (also called an oxide semiconductor) is applied to the semiconductor layer where the channel is formed.

[0347] The transistor 320 has a semiconductor layer 321, an insulating layer 323, a conductive layer 324, a pair of conductive layers 325, an insulating layer 326, and a conductive layer 327.

[0348] Substrate 331 corresponds to substrate 291 in Figures 10A and 10B.

[0349] An insulating layer 332 is provided on the substrate 331. The insulating layer 332 functions as a barrier layer that prevents impurities such as water or hydrogen from diffusing from the substrate 331 to the transistor 320, and prevents oxygen from detaching from the semiconductor layer 321 to the insulating layer 332. As the insulating layer 332, for example, a film that is less susceptible to hydrogen or oxygen diffusion than a silicon oxide film can be used, such as an aluminum oxide film, a hafnium oxide film, or a silicon nitride film.

[0350] A conductive layer 327 is provided on an insulating layer 332, and an insulating layer 326 is provided covering the conductive layer 327. The conductive layer 327 functions as the first gate electrode of the transistor 320, and a portion of the insulating layer 326 functions as the first gate insulating layer. It is preferable to use an oxide insulating film, such as a silicon oxide film, for at least the portion of the insulating layer 326 that is in contact with the semiconductor layer 321. It is preferable that the upper surface of the insulating layer 326 is flattened.

[0351] The semiconductor layer 321 is provided on the insulating layer 326. Preferably, the semiconductor layer 321 has a metal oxide (also called an oxide semiconductor) film that exhibits semiconductor properties. A pair of conductive layers 325 are provided in contact with the semiconductor layer 321 and function as a source electrode and a drain electrode.

[0352] An insulating layer 328 is provided covering the top and side surfaces of a pair of conductive layers 325, as well as the side surfaces of the semiconductor layer 321, and an insulating layer 264 is provided on the insulating layer 328. The insulating layer 328 functions as a barrier layer to prevent impurities such as water or hydrogen from diffusing into the semiconductor layer 321 from the insulating layer 264, etc., and to prevent oxygen from detaching from the semiconductor layer 321. An insulating film similar to that used for the insulating layer 332 can be used for the insulating layer 328.

[0353] The insulating layer 328 and the insulating layer 264 are provided with openings that reach the semiconductor layer 321. Inside these openings, an insulating layer 323 in contact with the upper surface of the semiconductor layer 321 and a conductive layer 324 are embedded. The conductive layer 324 functions as a second gate electrode, and the insulating layer 323 functions as a second gate insulating layer.

[0354] The upper surfaces of the conductive layer 324, the insulating layer 323, and the insulating layer 264 are flattened so that their heights are the same or approximately the same, and the insulating layer 329 and insulating layer 265 are provided covering them.

[0355] Insulating layers 264 and 265 function as interlayer insulating layers. Insulating layer 329 functions as a barrier layer to prevent impurities such as water or hydrogen from diffusing into the transistor 320 from insulating layer 265, etc. As insulating layer 329, an insulating film similar to that used for insulating layers 328 and 332 can be used.

[0356] A plug 274, which is electrically connected to one of the pair of conductive layers 325, is provided so as to be embedded in the insulating layers 265, 329, and 264. Here, it is preferable that the plug 274 has a conductive layer 274a that covers the sides of the openings of the insulating layers 265, 329, 264, and 328, and a part of the upper surface of the conductive layer 325, and a conductive layer 274b that is in contact with the upper surface of the conductive layer 274a. In this case, it is preferable to use a conductive material that does not easily allow hydrogen and oxygen to diffuse as the conductive layer 274a.

[0357] [Display device 200E] The display device 200E shown in Figure 15 has a configuration in which transistors 320A and 320B, each having an oxide semiconductor in the semiconductor where the channel is formed, are stacked.

[0358] The configuration of transistors 320A and 320B, and their surrounding components, can be based on the display device 200D described above.

[0359] In this example, we have used a configuration in which two transistors having oxide semiconductors are stacked, but this is not the only option. For example, a configuration in which three or more transistors are stacked may also be used.

[0360] [Display device 200F] The display device 200F shown in Figure 16 has a configuration in which a transistor 310 with a channel formed on a substrate 301 and a transistor 320 containing a metal oxide in the semiconductor layer where the channel is formed are stacked.

[0361] An insulating layer 261 is provided covering the transistor 310, and a conductive layer 251 is provided on the insulating layer 261. An insulating layer 262 is provided covering the conductive layer 251, and a conductive layer 252 is provided on the insulating layer 262. The conductive layers 251 and 252 each function as wiring. An insulating layer 263 and an insulating layer 332 are provided covering the conductive layer 252, and a transistor 320 is provided on the insulating layer 332. An insulating layer 265 is provided covering the transistor 320, and a capacitor 240 is provided on the insulating layer 265. The capacitor 240 and the transistor 320 are electrically connected by a plug 274.

[0362] Transistor 320 can be used as a transistor constituting a pixel circuit. Transistor 310 can also be used as a transistor constituting a pixel circuit, or as a transistor constituting a drive circuit (gate line drive circuit, source line drive circuit) for driving the pixel circuit. Furthermore, transistors 310 and 320 can be used as transistors constituting various circuits such as arithmetic circuits or memory circuits.

[0363] This configuration allows for the formation of not only pixel circuits but also drive circuits directly beneath the light-emitting elements, making it possible to miniaturize the display panel compared to cases where the drive circuits are located around the display area.

[0364] [Display device 200G] The display device 200G shown in Figure 17 has a configuration in which a transistor 310 with a channel formed on a substrate 301, and transistors 320A and 320B containing a metal oxide in the semiconductor layer where the channel is formed are stacked.

[0365] Transistor 320A can be used as a transistor constituting a pixel circuit. Transistor 310 can be used as a transistor constituting a pixel circuit, or as a transistor constituting a drive circuit (gate line drive circuit, source line drive circuit) for driving the pixel circuit. Transistor 320B may be used as a transistor constituting a pixel circuit, or as a transistor constituting the above-mentioned drive circuit. Furthermore, transistors 310, 320A, and 320B can be used as transistors constituting various circuits such as arithmetic circuits or memory circuits.

[0366] The following describes the components, such as transistors, that can be applied to display devices.

[0367] [Transistor] A transistor comprises a conductive layer that functions as a gate electrode, a semiconductor layer, a conductive layer that functions as a source electrode, a conductive layer that functions as a drain electrode, and an insulating layer that functions as a gate insulating layer.

[0368] The structure of the transistor in the display device according to one aspect of the present invention is not particularly limited. For example, it may be a planar transistor, a staggered transistor, or an inverse staggered transistor. It may also be a top-gate or bottom-gate transistor structure. Alternatively, gate electrodes may be provided above and below the channel.

[0369] The crystallinity of the semiconductor material used in the transistor is not particularly limited; amorphous semiconductors, crystalline semiconductors (microcrystalline semiconductors, polycrystalline semiconductors, single-crystal semiconductors, or semiconductors with crystalline regions in part) may be used. Using a crystalline semiconductor is preferable because it can suppress the degradation of transistor characteristics.

[0370] The following section describes transistors that specifically use metal oxide films as the semiconductor layer in which the channel is formed.

[0371] As semiconductor materials used in transistors, metal oxides with an energy gap of 2 eV or more, preferably 2.5 eV or more, and more preferably 3 eV or more, can be used. Typical examples include metal oxides containing indium, such as CAC-OS described later.

[0372] Transistors using metal oxides, which have a wider bandgap and lower carrier concentration than silicon, can retain the charge stored in a capacitive element connected in series with the transistor for a long period of time due to their small off-current.

[0373] The semiconductor layer can be a film represented as In-M-Zn oxide containing, for example, indium, zinc, and M (where M is a metal such as aluminum, titanium, gallium, germanium, yttrium, zirconium, lanthanum, cerium, tin, neodymium, or hafnium).

[0374] When the metal oxide constituting the semiconductor layer is an In-M-Zn oxide, the atomic ratio of the metal elements in the sputtering target used to form the In-M-Zn oxide preferably satisfies In≧M and Zn≧M. Examples of such atomic ratios of the metal elements in the sputtering target include In:M:Zn = 1:1:1, In:M:Zn = 1:1:1.2, In:M:Zn = 1:1:2, In:M:Zn = 3:1:2, In:M:Zn = 4:2:3, In:M:Zn = 4:2:4.1, In:M:Zn = 5:1:6, In:M:Zn = 5:1:7, In:M:Zn = 5:1:8, etc. Note that the atomic ratio of the semiconductor layer formed includes a variation of plus or minus 40% of the atomic ratio of the metal elements contained in the above sputtering target.

[0375] As the semiconductor layer, a metal oxide film with a low carrier concentration is used. For example, the semiconductor layer has a carrier concentration of 1×10 17 cm -3 or less, preferably 1×10 15 cm -3 or less, more preferably 1×10 13 cm -3 or less, even more preferably 1×10 11 cm -3 or less, still more preferably 1×10 10 cm -3 or less, and metal oxides with a carrier concentration of 1×10 -9 cm -3 or more can be used. Such metal oxides are called high-purity intrinsic or substantially high-purity intrinsic metal oxides. It can be said that the oxide semiconductor has a low density of defect levels and stable characteristics.

[0376] Note that it is not limited to these, and an oxide semiconductor with an appropriate composition may be used according to the required semiconductor characteristics and electrical characteristics (field-effect mobility, threshold voltage, etc.) of the transistor. Also, in order to obtain the required semiconductor characteristics of the transistor, it is preferable to make the carrier concentration, impurity concentration, defect density, atomic ratio of metal elements to oxygen, interatomic distance, density, etc. of the semiconductor layer appropriate.

[0377] When silicon or carbon, which are Group 14 elements, are present in the metal oxide constituting the semiconductor layer, oxygen vacancies increase in the semiconductor layer, causing it to become n-type. Therefore, the concentration of silicon or carbon in the semiconductor layer (concentration obtained by secondary ion mass spectrometry) is 2 × 10⁻¹⁰. 18 atoms / cm 3 The following is preferably 2 × 10 17 atoms / cm 3 The following applies:

[0378] Furthermore, alkali metals and alkaline earth metals can generate carriers when they combine with metal oxides, which can increase the transistor's off-current. For this reason, the concentration of alkali metals or alkaline earth metals obtained by secondary ion mass spectrometry in the semiconductor layer should be set to 1 × 10⁻⁶. 18 atoms / cm 3 The following is preferably 2 × 10 16 atoms / cm 3 Do the following:

[0379] Furthermore, if nitrogen is present in the metal oxide constituting the semiconductor layer, electrons, which act as carriers, are generated, increasing the carrier concentration and making it easier for the transistor to become n-type. As a result, transistors using metal oxides containing nitrogen tend to exhibit normally-on characteristics. Therefore, the nitrogen concentration obtained by secondary ion mass spectrometry in the semiconductor layer is 5 × 10⁻⁶. 18 atoms / cm 3 The following is preferable:

[0380] Oxide semiconductors are divided into single-crystal oxide semiconductors and non-single-crystal oxide semiconductors. Non-single-crystal oxide semiconductors include CAAC-OS (c-axis-aligned crystalline oxide semiconductor), polycrystalline oxide semiconductors, nc-OS (nanocrystalline oxide semiconductor), pseudo-amorphous oxide semiconductors (a-like OS: amorphous-like oxide semiconductor), and amorphous oxide semiconductors.

[0381] Furthermore, CAC-OS (cloud-aligned composite oxide semiconductor) may be used for the semiconductor layer of the transistor disclosed in one aspect of the present invention.

[0382] Furthermore, the semiconductor layer of the transistor disclosed in one aspect of the present invention can suitably use the non-single-crystal oxide semiconductor described above. In addition, nc-OS, CAAC-OS, or CAC-OS can suitably be used as the non-single-crystal oxide semiconductor.

[0383] Furthermore, the semiconductor layer may be a mixed film having two or more regions from among CAAC-OS, polycrystalline oxide semiconductor, nc-OS, CAC-OS, pseudo-amorphous oxide semiconductor, and amorphous oxide semiconductor. The mixed film may have a single-layer structure or a stacked structure that includes, for example, two or more of the regions described above.

[0384] Furthermore, transistors having a metal oxide film in the semiconductor layer do not require a laser crystallization process, unlike transistors using low-temperature polysilicon. Therefore, even for display devices using large-area substrates, manufacturing costs can be reduced. Moreover, in high-resolution, large-scale display devices such as Ultra Hi-Vision ("4K resolution", "4K2K", "4K") and Super Hi-Vision ("8K resolution", "8K4K", "8K"), using transistors with CAC-OS in the semiconductor layer in the drive circuit and display unit is preferable because it enables writing in a short time and reduces display defects.

[0385] Alternatively, silicon may be used as the semiconductor in which the transistor channel is formed. Amorphous silicon may be used as the silicon, but crystalline silicon is particularly preferred. For example, microcrystalline silicon, polycrystalline silicon, or single-crystal silicon are preferred. In particular, polycrystalline silicon can be formed at a lower temperature than single-crystal silicon and has higher field-effect mobility and higher reliability than amorphous silicon.

[0386] [Conductive layer] Materials that can be used for conductive layers such as the gate, source, and drain of transistors, as well as various wirings and electrodes that constitute display devices, include metals such as aluminum, titanium, chromium, nickel, copper, yttrium, zirconium, molybdenum, silver, tantalum, or tungsten, or alloys mainly composed of these metals. Films containing these materials can be used as single layers or in multilayer structures. For example, there are single-layer structures of aluminum films containing silicon, two-layer structures of aluminum films laminated on titanium films, two-layer structures of aluminum films laminated on tungsten films, two-layer structures of copper films laminated on copper-magnesium-aluminum alloy films, two-layer structures of copper films laminated on titanium films, two-layer structures of copper films laminated on tungsten films, three-layer structures of titanium films or titanium nitride films with aluminum films or copper films laminated on top and titanium films or titanium nitride films formed on top of those, and three-layer structures of molybdenum films or molybdenum nitride films with aluminum films or copper films laminated on top and molybdenum films or molybdenum nitride films formed on top of those. Furthermore, oxides such as indium oxide, tin oxide, or zinc oxide may be used. In addition, using copper containing manganese is preferable because it improves the controllability of the shape through etching.

[0387] [Insulating layer] In addition to resins such as acrylic resin and epoxy resin, and resins having siloxane bonds such as silicone, inorganic insulating materials such as silicon oxide, silicon oxide nitride, silicon nitride, silicon nitride, and aluminum oxide can also be used as insulating materials for each insulating layer.

[0388] In this specification, "oxide-nitride" refers to a material in which the oxygen content is greater than the nitrogen content, and "nitride oxide" refers to a material in which the nitrogen content is greater than the oxygen content. For example, when "silicon oxynitride" is written, it refers to a material in which the oxygen content is greater than the nitrogen content, and when "silicon nitride oxide" is written, it refers to a material in which the nitrogen content is greater than the oxygen content.

[0389] Furthermore, it is preferable that the light-emitting element is placed between a pair of insulating films with low water permeability. This prevents impurities such as water from entering the light-emitting element, thereby suppressing a decrease in the reliability of the device.

[0390] Examples of insulating films with low water permeability include films containing nitrogen and silicon, such as silicon nitride films and silicon oxide nitride films, or films containing nitrogen and aluminum, such as aluminum nitride films. Alternatively, silicon oxide films, silicon oxide nitride films, aluminum oxide films, etc., may also be used.

[0391] For example, the amount of water vapor transmitted through a low-permeability insulating film is 1 × 10⁻⁶ -5 [g / (m 2 (day) Preferably 1 x 10 -6 [g / (m 2 ·day) Below, more preferably 1 × 10 -7 [g / (m 2 (day) More preferably 1 x 10 -8 [g / (m 2 (・day) and below.

[0392] This embodiment can be implemented in appropriate combination with other embodiments described herein, at least in part.

[0393] [Display device 200H] Figure 18 shows a perspective view of the display device 200H, and Figure 19A shows a cross-sectional view of the display device 200H.

[0394] The display device 200H has a configuration in which substrate 170 and substrate 151 are bonded together. In Figure 18, substrate 170 is clearly indicated by a dashed line.

[0395] The display device 200H includes a display unit 167, a connection unit 140, a circuit 164, wiring 165, etc. Figure 18 shows an example in which IC 173 and FPC 172 are mounted on the display device 200H. Therefore, the configuration shown in Figure 18 can also be described as a display module having the display device 200H, an IC (integrated circuit), and an FPC.

[0396] The connection portion 140 is provided on the outside of the display portion 167. The connection portion 140 can be provided along one or more sides of the display portion 167. There may be one or more connection portions 140. Figure 18 shows an example in which the connection portion 140 is provided so as to surround all four sides of the display portion. At the connection portion 140, the common electrode of the light-emitting element and the conductive layer are electrically connected, and a potential can be supplied to the common electrode.

[0397] For example, a scan line drive circuit can be used as the circuit 164. Although Figure 19A shows an example in which the insulating layer 105 in the region where the circuit 164 is provided does not have a recess 175, the recess 175 may be provided in the insulating layer 105 in the region where the circuit 164 is provided. For example, the transistor of the circuit 164 and the recess 175 may be superimposed. In such a configuration, for example, the insulating layer 105 is located on the transistor of the circuit 164, and the surface of the insulating layer 105 is covered with an insulating layer provided using the same film as insulating layer 118a, insulating layer 118b, insulating layer 118d, etc.

[0398] Wiring 165 has the function of supplying signals and power to the display unit 167 and the circuit 164. These signals and power are input to wiring 165 from an external source via FPC 172, or from IC 173.

[0399] Figure 18 shows an example in which IC 173 is provided on the substrate 151 using a COG (Chip On Glass) method or COF (Chip On Film) method. IC 173 can be an IC having, for example, a scan line drive circuit or a signal line drive circuit. Note that the display device 200H and the display module may be configured without an IC. Alternatively, the IC may be mounted on an FPC using a COF method or the like.

[0400] Figure 19A shows an example of a cross-section of the display device 200H when a portion of the area including the FPC 172, a portion of the circuit 164, a portion of the display unit 167, a portion of the connection unit 140, and a portion of the area including the end are cut.

[0401] The display device 200H shown in Figure 19A has a transistor 201, a transistor 205, a light-emitting element 110b, a light-emitting element 110a, and a light-receiving element 110d, etc., between substrate 151 and substrate 170. Light-emitting element 110a is, for example, a light-emitting element that emits red light R. Light-emitting element 110b is, for example, a light-emitting element that emits green light G. The light-receiving element 110d is, for example, a light-emitting element that has the function of detecting light L.

[0402] The light-emitting elements 110a and 110b have the same structure as the light-emitting elements 110R and 110G shown in Figure 2A, etc., except that the configuration of the pixel electrodes is different. Details of the light-emitting elements and light-receiving elements can be found in Embodiment 1. The light-receiving element 110d has the same structure as the light-receiving element 110S shown in Figure 2B, etc., except that the configuration of the pixel electrodes is different. The light-emitting elements 110a, 110b, and light-receiving element 110d are provided on the insulating layer 105. In addition, although not shown, the display device 200H has a light-emitting element 110c (not shown) on the insulating layer 105 between the substrate 151 and the substrate 170, and the light-emitting element 110c has the same structure as the light-emitting element 110B shown in Figure 2A, etc., except that the configuration of the pixel electrodes is different.

[0403] In the display device 200H, the organic layer 112R, the organic layer 112G, and the PS layer 155S are separated and spaced apart, so that even in a high-resolution display device, the occurrence of crosstalk between adjacent subpixels can be suppressed. Therefore, a display device that is both high-resolution and has high display quality can be realized.

[0404] The light-emitting element 110a has a conductive layer 115a, a conductive layer 127a on the conductive layer 115a, and a conductive layer 129a on the conductive layer 127a. All of the conductive layers 115a, 127a, and 129a can be called pixel electrodes, or only a part of them can be called pixel electrodes.

[0405] The light-emitting element 110b has a conductive layer 115b, a conductive layer 127b on the conductive layer 115b, and a conductive layer 129b on the conductive layer 127b. All of the conductive layers 115b, 127b, and 129b can be called pixel electrodes, or only a part of them can be called pixel electrodes.

[0406] The light-receiving element 110d has a conductive layer 115d, a conductive layer 127d on the conductive layer 115d, and a conductive layer 129d on the conductive layer 127d. All of the conductive layers 115d, 127d, and 129d can be called pixel electrodes, or only a part of them can be called pixel electrodes.

[0407] The conductive layer 115a is connected to the conductive layer 222b of the transistor 205 through openings provided in the insulating layers 105 and 106. The edges of the conductive layers 115a and 127a are aligned. The edge of the conductive layer 129a is located outside the edge of the conductive layer 127a. For example, a reflective conductive layer can be used for conductive layer 127a, and a translucent conductive layer can be used for conductive layer 129a.

[0408] The conductive layer 115b is connected to the conductive layer 222b of the transistor 205 through openings provided in the insulating layers 105 and 106. The edges of the conductive layers 115b and 127b are aligned. The edge of the conductive layer 129b is located outside the edge of the conductive layer 127b. For example, a reflective conductive layer can be used for conductive layer 127b, and a translucent conductive layer can be used for conductive layer 129b.

[0409] The conductive layer 115d is connected to the conductive layer 222b of the transistor 205 through openings provided in the insulating layers 105 and 106. The edges of the conductive layers 115d and 127d are aligned. The edge of the conductive layer 129d is located outside the edge of the conductive layer 127d. For example, a reflective conductive layer can be used for conductive layer 127d, and a translucent conductive layer can be used for conductive layer 129d.

[0410] The conductive layers 115a, 115b, and 115d have recesses formed to cover the openings provided in the insulating layers 105 and 106. Layer 128 is embedded in these recesses.

[0411] Layer 128 has the function of flattening the recesses of conductive layers 115a, 115b, and 115d. Conductive layers 127a, 127b, and 127d, which are electrically connected to conductive layers 115a, 115b, and 115d, are provided on conductive layers 115a, 115b, and 115d and on layer 128. Therefore, regions overlapping with the recesses of conductive layers 115a, 115b, and 115d can also be used as light-emitting regions, thereby increasing the aperture ratio of the pixels.

[0412] Layer 128 may be an insulating layer or a conductive layer. Various inorganic insulating materials, organic insulating materials, and conductive materials can be used for layer 128 as appropriate. In particular, it is preferable that layer 128 be formed using an insulating material.

[0413] As layer 128, an insulating layer having an organic material can be suitably used. For example, acrylic resin, polyimide resin, epoxy resin, polyamide resin, polyimidoamide resin, siloxane resin, benzocyclobutene resin, phenol resin, and precursors of these resins can be used as layer 128. Alternatively, a photosensitive resin can be used as layer 128. The photosensitive resin can be a positive-type material or a negative-type material.

[0414] By using a photosensitive resin, layer 128 can be fabricated using only exposure and development processes, reducing the impact on the surfaces of conductive layers 115a, 115b, and 115d due to dry etching or wet etching. Furthermore, by forming layer 128 using a negative-type photosensitive resin, it may be possible to form layer 128 using the same photomask (exposure mask) used to form the openings of insulating layers 105 and 106.

[0415] The top and sides of the conductive layer 129a are covered by the organic layer 112R. Similarly, the top and sides of the conductive layer 129b are covered by the organic layer 112G. In addition, the top and sides of the conductive layer 129d are covered by the PS layer 155S. Therefore, the entire region where the conductive layers 127a, 127b, and 127d are provided can be used as the light-emitting region or light-receiving region of the light-emitting element 110a, 110b, and light-receiving element 110d, thereby increasing the aperture ratio of the pixels.

[0416] Furthermore, a protective layer 121 is provided on the light-emitting element 110a, the light-emitting element 110b, and the light-receiving element 110d, respectively. By providing a protective layer 121 that covers the light-emitting elements, it is possible to suppress the ingress of impurities such as water into the light-emitting elements and improve the reliability of the light-emitting elements.

[0417] The protective layer 121 and the substrate 170 are bonded together via an adhesive layer 142. For sealing the light-emitting element, a solid sealing structure or a hollow sealing structure can be applied. In Figure 19A, the space between the substrate 170 and the substrate 151 is filled with the adhesive layer 142, demonstrating a solid sealing structure. Alternatively, the space may be filled with an inert gas (such as nitrogen or argon), demonstrating a hollow sealing structure. In this case, the adhesive layer 142 may be provided so as not to overlap with the light-emitting element. Furthermore, the space may be filled with a resin different from the frame-shaped adhesive layer 142. The description of adhesive layer 171 can be used as an example of adhesive layer 142.

[0418] In the connection portion 140, a conductive layer 123 is provided on the insulating layer 105 and the insulating layer 106. The conductive layer 123 is shown as an example of a laminated structure consisting of a conductive film obtained by processing the same conductive film as conductive layers 115a, 115b, and 115d, a conductive film obtained by processing the same conductive film as conductive layers 127a, 127b, and 127d, and a conductive film obtained by processing the same conductive film as conductive layers 129a, 129b, and 129d. The ends of the conductive layer 123 are covered by the insulating layer 118a, the insulating layer 125, and the resin layer 126. A common layer 114 is provided on the conductive layer 123, and a common electrode 113 is provided on the common layer 114. The conductive layer 123 and the common electrode 113 are electrically connected via the common layer 114. Note that the common layer 114 does not necessarily have to be formed in the connection portion 140. In this case, the conductive layer 123 and the common electrode 113 are in direct contact and electrically connected. The insulating layer 105 is provided with a recess 175 having an area that overlaps with the conductive layer 123. In addition, an insulating layer 118g is provided so as to cover the side and top surfaces of the conductive layer 123. The insulating layer 118g can be formed by processing the same insulating film as insulating layer 118a, insulating layer 118b, insulating layer 118c (not shown), insulating layer 118d, etc. At the connection portion 140, by providing the insulating layer 118g so as to cover the side and top surfaces of the conductive layer 123, the adhesion between the insulating layer 106 and the conductive layer 123 may be improved.

[0419] The display device 200H is of the top-emission type. The light emitted by the light-emitting element is emitted towards the substrate 170. It is preferable to use a material with high transmittance to visible light for the substrate 170. The pixel electrodes contain a material that reflects visible light, and the counter electrodes (common electrodes 113) contain a material that transmits visible light.

[0420] The laminated structure from substrate 151 to insulating layer 215 corresponds to the substrate 101 containing the transistor in Embodiment 1.

[0421] Both transistors 201 and 205 are formed on the substrate 151. These transistors can be manufactured using the same materials and the same process.

[0422] On the substrate 151, insulating layers 211, 213, 215, 105, and 106 are provided in this order.

[0423] For the insulating layer 105 and the insulating layer 106, refer to the description in Embodiment 1.

[0424] A portion of the insulating layer 211 functions as a gate insulating layer for each transistor. A portion of the insulating layer 213 functions as a gate insulating layer for each transistor. The insulating layer 215 is provided covering the transistors. The insulating layer 105 is provided covering the transistors and functions as a planarization layer. The number of gate insulating layers and the number of insulating layers covering the transistors are not limited and may be a single layer or two or more layers, respectively.

[0425] It is preferable to use a material that does not easily allow impurities such as water and hydrogen to diffuse into at least one layer of the insulating layer covering the transistor. This allows the insulating layer to function as a barrier layer. With such a configuration, the diffusion of impurities from the outside into the transistor can be effectively suppressed, thereby improving the reliability of the display device.

[0426] It is preferable to use inorganic insulating films for insulating layer 211, insulating layer 213, and insulating layer 215. Examples of inorganic insulating films that can be used include silicon nitride film, silicon oxide nitride film, silicon oxide film, silicon nitride oxide film, aluminum oxide film, and aluminum nitride film. Alternatively, hafnium oxide film, yttrium oxide film, zirconium oxide film, gallium oxide film, tantalum oxide film, magnesium oxide film, lanthanum oxide film, cerium oxide film, and neodymium oxide film may also be used. Furthermore, two or more of the above insulating films may be laminated together.

[0427] Transistors 201 and 205 have a conductive layer 221 that functions as a gate, an insulating layer 211 that functions as a gate insulating layer, conductive layers 222a and 222b that function as source and drain, a semiconductor layer 231, an insulating layer 213 that functions as a gate insulating layer, and a conductive layer 223 that functions as a gate. Here, the same hatching pattern is applied to multiple layers obtained by processing the same conductive film. The insulating layer 211 is located between the conductive layer 221 and the semiconductor layer 231. The insulating layer 213 is located between the conductive layer 223 and the semiconductor layer 231.

[0428] The transistor structure of the display device of this embodiment is not particularly limited. For example, planar transistors, staggered transistors, inverse staggered transistors, etc., can be used. Furthermore, either a top-gate or bottom-gate transistor structure may be used. Alternatively, gates may be provided above and below the semiconductor layer in which the channel is formed.

[0429] Transistors 201 and 205 are configured in which a semiconductor layer on which a channel is formed is sandwiched between two gates. The transistors may be driven by connecting the two gates and supplying them with the same signal. Alternatively, the threshold voltage of the transistors may be controlled by applying a potential to control the threshold voltage to one of the two gates and a potential to drive the other gate.

[0430] The crystallinity of the semiconductor material used in the transistor is not particularly limited; amorphous semiconductors, single-crystal semiconductors, or semiconductors with crystalline properties other than single crystals (microcrystalline semiconductors, polycrystalline semiconductors, or semiconductors with crystalline regions in part) may be used. Using a single-crystal semiconductor or a semiconductor with crystalline properties is preferable because it can suppress the degradation of transistor characteristics.

[0431] The semiconductor layer of the transistor preferably has a metal oxide (also called an oxide semiconductor). In other words, the display device of this embodiment preferably uses a transistor (hereinafter referred to as an OS transistor) that uses a metal oxide in the channel formation region.

[0432] Examples of crystalline oxide semiconductors include CAAC (c-axis-aligned crystalline)-OS and nc (nanocrystalline)-OS.

[0433] Alternatively, a transistor using silicon as the channel-forming region (Si transistor) may be used. Examples of silicon include single-crystal silicon, polycrystalline silicon, and amorphous silicon. In particular, a transistor having low-temperature polysilicon (LTPS (Low Temperature Poly Silicon)) in the semiconductor layer (hereinafter also referred to as an LTPS transistor) can be used. LTPS transistors have high field-effect mobility and good frequency characteristics.

[0434] By using Si transistors such as LTPS transistors, circuits that need to be driven at high frequencies (e.g., source driver circuits) can be fabricated on the same board as the display unit. This simplifies the external circuits implemented in the display device, reducing component and mounting costs.

[0435] OS transistors have extremely high field-effect mobility compared to transistors using amorphous silicon. Furthermore, OS transistors exhibit remarkably low source-drain leakage current (hereinafter also referred to as off-current) in the off state, allowing them to retain charge stored in a capacitor connected in series with the transistor for extended periods. Additionally, the application of OS transistors can reduce the power consumption of display devices.

[0436] Furthermore, the off-current value of an OS transistor per 1 μm channel width at room temperature is 1 aA (1 × 10⁻¹⁰). -18 A) Below, 1zA(1×10 -21 A) Less than or equal to 1yA(1×10 -24 A) It can be less than or equal to the following. Note that the off-current value of a Si transistor per 1 μm of channel width at room temperature is 1 fA (1 × 10⁻¹⁰). -15 A) More than 1pA (1×10 -12 A) The answer is as follows. Therefore, it can be said that the off-current of an OS transistor is about 10 orders of magnitude lower than that of a Si transistor.

[0437] Furthermore, to increase the luminescence brightness of the light-emitting elements included in the pixel circuit, it is necessary to increase the amount of current flowing through the light-emitting elements. To achieve this, it is necessary to increase the source-drain voltage of the drive transistor included in the pixel circuit. Compared to Si transistors, OS transistors have a higher breakdown voltage between the source and drain, so a higher voltage can be applied between the source and drain of an OS transistor. Therefore, by using an OS transistor as the drive transistor included in the pixel circuit, the amount of current flowing through the light-emitting elements can be increased, thereby increasing the luminescence brightness of the light-emitting elements.

[0438] Furthermore, when the transistor operates in the saturation region, OS transistors exhibit smaller changes in source-drain current in response to changes in gate-source voltage compared to Si transistors. Therefore, by using OS transistors as driving transistors in the pixel circuit, the current flowing between the source and drain can be precisely controlled by changes in gate-source voltage, thereby controlling the amount of current flowing to the light-emitting element. This allows for a wider range of tonal gradations in the pixel circuit.

[0439] Furthermore, in terms of the saturation characteristics of the current flowing when a transistor operates in the saturation region, OS transistors can supply a more stable current (saturation current) than Si transistors, even when the source-drain voltage gradually increases. Therefore, by using OS transistors as driving transistors, a stable current can be supplied to the light-emitting element even if there are variations in the current-voltage characteristics of the EL device. In other words, when operating in the saturation region, the source-drain current remains almost unchanged even when the source-drain voltage is increased, thus stabilizing the luminescence brightness of the light-emitting element.

[0440] As described above, by using OS transistors in the drive transistors included in the pixel circuit, it is possible to achieve "suppression of black level floating," "increase in luminescence brightness," "multi-gradation," and "suppression of variations in light-emitting elements."

[0441] The semiconductor layer preferably comprises, for example, indium, M (where M is one or more selected from gallium, aluminum, silicon, boron, yttrium, tin, copper, vanadium, beryllium, titanium, iron, nickel, germanium, zirconium, molybdenum, lanthanum, cerium, neodymium, hafnium, tantalum, tungsten, and magnesium), and zinc. In particular, M is preferably one or more selected from aluminum, gallium, yttrium, and tin.

[0442] In particular, it is preferable to use an oxide containing indium (In), gallium (Ga), and zinc (Zn) (also written as IGZO) as the semiconductor layer. Alternatively, it is preferable to use an oxide containing indium, tin, and zinc. Alternatively, it is preferable to use an oxide containing indium, gallium, tin, and zinc. Alternatively, it is preferable to use an oxide containing indium (In), aluminum (Al), and zinc (Zn) (also written as IAZO). Alternatively, it is preferable to use an oxide containing indium (In), aluminum (Al), gallium (Ga), and zinc (Zn) (also written as IAGZO).

[0443] When the semiconductor layer is an In-M-Zn oxide, it is preferable that the atomic ratio of In in the In-M-Zn oxide is greater than or equal to the atomic ratio of M. Possible atomic ratios of metal elements in such an In-M-Zn oxide include: In:M:Zn=1:1:1 or near that composition, In:M:Zn=1:1:1.2 or near that composition, In:M:Zn=1:3:2 or near that composition, In:M:Zn=1:3:4 or near that composition, In:M:Zn=2:1:3 or near that composition, In:M:Zn=3:1:2 or near that composition, and In:M:Zn=4:2:3 Examples include compositions near the desired atomic ratio, such as In:M:Zn=4:2:4.1 or near that ratio, In:M:Zn=5:1:3 or near that ratio, In:M:Zn=5:1:6 or near that ratio, In:M:Zn=5:1:7 or near that ratio, In:M:Zn=5:1:8 or near that ratio, In:M:Zn=6:1:6 or near that ratio, In:M:Zn=5:2:5 or near that ratio, etc. Note that "nearby composition" includes a range of ±30% of the desired atomic ratio.

[0444] For example, when describing a composition with an atomic ratio of In:Ga:Zn = 4:2:3 or a similar ratio, it includes cases where, when In is set to 4, Ga is between 1 and 3, and Zn is between 2 and 4. Also, when describing a composition with an atomic ratio of In:Ga:Zn = 5:1:6 or a similar ratio, it includes cases where, when In is set to 5, Ga is greater than 0.1 and 2 or less, and Zn is between 5 and 7. Furthermore, when describing a composition with an atomic ratio of In:Ga:Zn = 1:1:1 or a similar ratio, it includes cases where, when In is set to 1, Ga is greater than 0.1 and 2 or less, and Zn is greater than 0.1 and 2 or less.

[0445] The transistors in circuit 164 and the transistors in display unit 167 may have the same structure or different structures. The structures of the multiple transistors in circuit 164 may all be the same or there may be two or more different structures. Similarly, the structures of the multiple transistors in display unit 167 may all be the same or there may be two or more different structures.

[0446] All of the transistors in the display unit 167 may be OS transistors, all of the transistors in the display unit 167 may be Si transistors, or some of the transistors in the display unit 167 may be OS transistors and the rest may be Si transistors.

[0447] For example, by using both LTPS transistors and OS transistors in the display unit 167, a display device with low power consumption and high driving capability can be realized. Furthermore, a configuration combining LTPS transistors and OS transistors is sometimes referred to as LTPO. In a more preferable example, it is preferable to apply OS transistors to transistors that function as switches to control conduction and non-conductivity between wires, and LTPS transistors to transistors that control current.

[0448] For example, one of the transistors in the display unit 167 functions as a transistor for controlling the current flowing to the light-emitting element, and can also be called a drive transistor. One of the source and drain of the drive transistor is electrically connected to the pixel electrode of the light-emitting element. It is preferable to use an LTPS transistor for this drive transistor. This makes it possible to increase the current flowing to the light-emitting element in the pixel circuit.

[0449] On the other hand, the other transistor in the display unit 167 functions as a switch for controlling the selection and deselection of pixels, and can also be called a selection transistor. The gate of the selection transistor is electrically connected to the gate line, and one of the source and drain is electrically connected to the source line (signal line). It is preferable to use an OS transistor for the selection transistor. This makes it possible to maintain the gradation of pixels even when the frame frequency is significantly reduced (e.g., 1 fps or less), and thus power consumption can be reduced by stopping the driver when displaying still images.

[0450] Thus, a display device according to one aspect of the present invention can combine a high aperture ratio, high resolution, high display quality, and low power consumption.

[0451] Furthermore, one embodiment of the present invention is a display device having an OS transistor and an MML (metal maskless) structure light-emitting element. This configuration makes it possible to extremely reduce the leakage current that can flow through the transistor and the leakage current that can flow between adjacent light-emitting elements (also called lateral leakage current or side leakage current). With this configuration, when an image is displayed on the display device, the observer can observe one or more of the following: image sharpness, image clarity, high saturation, and high contrast ratio. Moreover, by having an extremely low leakage current that can flow through the transistor and lateral leakage current between light-emitting elements, it is possible to achieve a display with minimal light leakage that may occur when displaying black.

[0452] Figures 19B and 19C show other examples of transistor configurations.

[0453] Transistors 209 and 210 each have a conductive layer 221 that functions as a gate, an insulating layer 211 that functions as a gate insulating layer, a semiconductor layer 231 having a channel forming region 231i and a pair of low-resistance regions 231n, a conductive layer 222a connected to one of the pair of low-resistance regions 231n, a conductive layer 222b connected to the other of the pair of low-resistance regions 231n, an insulating layer 225 that functions as a gate insulating layer, a conductive layer 223 that functions as a gate, and an insulating layer 215 covering the conductive layer 223. The insulating layer 211 is located between the conductive layer 221 and the channel forming region 231i. The insulating layer 225 is located at least between the conductive layer 223 and the channel forming region 231i. Furthermore, an insulating layer 218 covering the transistor may be provided.

[0454] In the transistor 209 shown in Figure 19B, an example is shown where the insulating layer 225 covers the top and sides of the semiconductor layer 231. The conductive layers 222a and 222b are connected to the low-resistance region 231n through openings provided in the insulating layers 225 and 215, respectively. Of the conductive layers 222a and 222b, one functions as the source and the other as the drain.

[0455] On the other hand, in the transistor 210 shown in Figure 19C, the insulating layer 225 overlaps with the channel formation region 231i of the semiconductor layer 231, but does not overlap with the low-resistance region 231n. For example, the structure shown in Figure 19C can be fabricated by processing the insulating layer 225 using the conductive layer 223 as a mask. In Figure 19C, an insulating layer 215 is provided covering the insulating layer 225 and the conductive layer 223, and the conductive layer 222a and conductive layer 222b are connected to the low-resistance region 231n, respectively, through openings in the insulating layer 215.

[0456] A connection portion 204 is provided in the region of substrate 151 that does not overlap with substrate 170. At the connection portion 204, wiring 165 is electrically connected to FPC 172 via conductive layer 166 and connection layer 242. The conductive layer 166 is shown as an example of a laminated structure consisting of a conductive film obtained by processing the same conductive film as conductive layers 115a, 115b, and 115d, a conductive film obtained by processing the same conductive film as conductive layers 127a, 127b, and 127d, and a conductive film obtained by processing the same conductive film as conductive layers 129a, 129b, and 129d. On the upper surface of the connection portion 204, the conductive layer 166 is exposed. This allows the connection portion 204 and FPC 172 to be electrically connected via the connection layer 242. Figure 19A also shows an example in which the recess 175 is not provided around the area where the connecting layer 242 is provided, but the configuration may also include the recess 175 around the area where the connecting layer 242 is provided. In such a configuration, the recess 175 is provided so as to surround the connecting layer 242 when viewed from above.

[0457] It is preferable to provide a light-shielding layer 117 on the surface of the substrate 170 that faces the substrate 151. The light-shielding layer 117 can be provided between adjacent light-emitting elements, at connection points 140, and at circuits 164, etc. In addition, various optical components can be arranged on the outside of the substrate 170.

[0458] Examples of substrates 151 and 170 include glass substrates, quartz substrates, sapphire substrates, ceramic substrates, metals, alloys, and semiconductors, respectively. Furthermore, semiconductor substrates such as single-crystal semiconductor substrates, polycrystalline semiconductor substrates, compound semiconductor substrates such as silicon-germanium substrates, and SOI substrates made from silicon or silicon carbide can be used. Using a flexible material as the substrate can increase the flexibility of the display device. A polarizing plate may also be used as the substrate.

[0459] As substrates, polyester resins such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN), polyacrylonitrile resin, acrylic resin, polyimide resin, polymethyl methacrylate resin, polycarbonate (PC) resin, polyethersulfone (PES) resin, polyamide resin (nylon, aramid, etc.), polysiloxane resin, cycloolefin resin, polystyrene resin, polyamide-imide resin, polyurethane resin, polyvinyl chloride resin, polyvinylidene chloride resin, polypropylene resin, polytetrafluoroethylene (PTFE) resin, ABS resin, cellulose nanofiber, etc. may be used. Glass of a thickness sufficient to provide flexibility may also be used as a substrate.

[0460] Furthermore, when a circular polarizing plate is superimposed on a display device, it is preferable to use a substrate with high optical isotropy for the substrate of the display device. A substrate with high optical isotropy has low birefringence (or a small amount of birefringence).

[0461] For substrates with high optical isotropy, the absolute value of the retardation (phase difference) is preferably 30 nm or less, more preferably 20 nm or less, and even more preferably 10 nm or less.

[0462] Examples of films with high optical isotropy include triacetylcellulose (TAC, also known as cellulose triacetate) film, cycloolefin polymer (COP) film, cycloolefin copolymer (COC) film, and acrylic film.

[0463] Furthermore, when a film is used as the substrate, the film may absorb water, potentially causing wrinkles or other shape changes in the display device. Therefore, it is preferable to use a film with a low water absorption rate as the substrate. For example, it is preferable to use a film with a water absorption rate of 1% or less, more preferable to use a film with a water absorption rate of 0.1% or less, and even more preferable to use a film with a water absorption rate of 0.01% or less.

[0464] As the connecting layer 242, an anisotropic conductive film (ACF), an anisotropic conductive paste (ACP), etc., can be used.

[0465] [Example of a display device configuration] Figure 20A shows a block diagram of the display device 400. The display device 400 includes a display unit 404, a drive circuit unit 402, a drive circuit unit 403, and the like.

[0466] The display unit 404 has a plurality of pixels 430 arranged in a matrix. Each pixel 430 has sub-pixels 405R, 405G, and 405B. Each of the sub-pixels 405R, 405G, and 405B has a light-emitting element that functions as a display device.

[0467] Pixel 430 is electrically connected to wiring GL, wiring SLR, wiring SLG, and wiring SLB. Wiring SLR, wiring SLG, and wiring SLB are each electrically connected to drive circuit unit 402. Wiring GL is electrically connected to drive circuit unit 403. Drive circuit unit 402 functions as a source line drive circuit (also called a source driver), and drive circuit unit 403 functions as a gate line drive circuit (also called a gate driver). Wiring GL functions as a gate line, and wiring SLR, wiring SLG, and wiring SLB each function as source lines.

[0468] Sub-pixel 405R has a light-emitting element that emits red light. Sub-pixel 405G has a light-emitting element that emits green light. Sub-pixel 405B has a light-emitting element that emits blue light. This allows the display device 400 to display in full color. Pixel 430 may also have sub-pixels that emit light of other colors. For example, in addition to the three sub-pixels described above, pixel 430 may have a sub-pixel that emits white light, or a sub-pixel that emits yellow light, and so on.

[0469] Wiring GL is electrically connected to sub-pixels 405R, 405G, and 405B, which are arranged in the row direction (the direction in which wiring GL extends). Wiring SLR, SLG, and SLB are electrically connected to sub-pixels 405R, 405G, or 405B (not shown), respectively, which are arranged in the column direction (the direction in which wiring SLR, etc. extends).

[0470] [Example of pixel circuit configuration] Figure 20B shows an example of a circuit diagram for a pixel 405 that can be applied to the sub-pixels 405R, 405G, and 405B described above. Pixel 405 has transistors M1, M2, M3, capacitor C1, and light-emitting element EL. Wiring GL and wiring SL are electrically connected to pixel 405. Wiring SL corresponds to one of the wirings SLR, SLG, and SLB shown in Figure 20A.

[0471] Transistor M1 has its gate electrically connected to wiring GL, one of its source and drain electrically connected to wiring SL, and the other of its source and drain electrically connected to one electrode of capacitor C1 and the gate of transistor M2. Transistor M2 has one of its source and drain electrically connected to wiring AL, and the other of its source and drain electrically connected to one electrode of light-emitting element EL, the other electrode of capacitor C1, and one of its source and drain electric. Transistor M3 has its gate electrically connected to wiring GL, and the other of its source and drain electrically connected to wiring RL. The other electrode of light-emitting element EL is electrically connected to wiring CL.

[0472] A data potential is supplied to wiring SL. A selection signal is supplied to wiring GL. This selection signal includes a potential that makes the transistor conduct and a potential that makes it non-conductive.

[0473] A reset potential is applied to wiring RL. An anode potential is applied to wiring AL. A cathode potential is applied to wiring CL. In pixel 405, the anode potential is set to a higher potential than the cathode potential. The reset potential applied to wiring RL can be set to such a potential that the potential difference between the reset potential and the cathode potential is smaller than the threshold voltage of the light-emitting element EL. The reset potential can be set to a potential higher than the cathode potential, the same potential as the cathode potential, or a potential lower than the cathode potential.

[0474] Transistors M1 and M3 function as switches. Transistor M2 functions as a transistor for controlling the current flowing to the light-emitting element EL. For example, it can be said that transistor M1 functions as a selector transistor, and transistor M2 functions as a drive transistor.

[0475] Here, it is preferable to apply LTPS transistors to all of transistors M1 through M3. Alternatively, it is preferable to apply OS transistors to transistors M1 and M3 and an LTPS transistor to transistor M2.

[0476] Alternatively, OS transistors may be applied to all of transistors M1 through M3. In this case, one or more of the transistors in the drive circuit section 402 and the drive circuit section 403 may be LTPS transistors, and the other transistors may be OS transistors. For example, OS transistors may be applied to the transistors provided in the display section 404, and LTPS transistors may be applied to the transistors provided in the drive circuit section 402 and the drive circuit section 403.

[0477] As an OS transistor, a transistor using an oxide semiconductor in the semiconductor layer where the channel is formed can be used. The semiconductor layer preferably contains, for example, indium, M (where M is one or more selected from gallium, aluminum, silicon, boron, yttrium, tin, copper, vanadium, beryllium, titanium, iron, nickel, germanium, zirconium, molybdenum, lanthanum, cerium, neodymium, hafnium, tantalum, tungsten, and magnesium), and zinc. In particular, it is preferable that M is one or more selected from aluminum, gallium, yttrium, and tin. In particular, it is preferable to use an oxide containing indium, gallium, and zinc (also written as IGZO) as the semiconductor layer of the OS transistor. Alternatively, it is preferable to use an oxide containing indium, tin, and zinc. Alternatively, it is preferable to use an oxide containing indium, gallium, tin, and zinc.

[0478] Transistors using oxide semiconductors, which have a wider bandgap and lower carrier density than silicon, can achieve extremely low off-currents. Therefore, this low off-current allows the charge stored in a capacitor connected in series with the transistor to be retained for extended periods. For this reason, it is preferable to use transistors made of oxide semiconductors for transistors M1 and M3, which are connected in series with capacitor C1. By using transistors with oxide semiconductors as transistors M1 and M3, it is possible to prevent the charge held in capacitor C1 from leaking through transistor M1 or M3. Furthermore, because the charge held in capacitor C1 can be retained for extended periods, it becomes possible to display still images for extended periods without rewriting the data in pixel 405.

[0479] Note that in Figure 20B, the transistor is shown as an n-channel type transistor, but a p-channel type transistor can also be used.

[0480] Furthermore, it is preferable that each transistor in pixel 405 be formed in a row on the same substrate.

[0481] As the transistor in pixel 405, a transistor having a pair of gates that overlap across a semiconductor layer can be applied.

[0482] In a transistor having a pair of gates, configuring the pair of gates to be electrically connected to each other and given the same potential offers advantages such as increased on-current and improved saturation characteristics. Alternatively, one of the pair of gates may be given a potential that controls the transistor's threshold voltage. Furthermore, providing a constant potential to one of the pair of gates can improve the stability of the transistor's electrical characteristics. For example, one of the transistor's gates may be electrically connected to a wiring to which a constant potential is provided, or it may be electrically connected to its own source or drain.

[0483] The pixel 405 shown in Figure 20C is an example where transistors M1 and M3 each have a pair of gates. The pair of gates of transistors M1 and M3 are electrically connected. This configuration shortens the data writing time to the pixel 405.

[0484] Pixel 405, shown in Figure 20D, is an example in which a transistor with a pair of gates is applied to transistor M2, in addition to transistors M1 and M3. In transistor M2, the pair of gates are electrically connected. By applying such a transistor to transistor M2, the saturation characteristics are improved, making it easier to control the luminescence brightness of the light-emitting element EL and improving the display quality.

[0485] (Embodiment 3) This embodiment describes a light-emitting element that can be used in a display device according to one aspect of the present invention.

[0486] As shown in Figure 21A, the light-emitting element has an EL layer 763 between a pair of electrodes (lower electrode 761 and upper electrode 762). The EL layer 763 can be composed of multiple layers, such as layer 780, light-emitting layer 771, and layer 790.

[0487] The light-emitting layer 771 has at least a light-emitting substance (also called a light-emitting material).

[0488] When the lower electrode 761 is the anode and the upper electrode 762 is the cathode, layer 780 has one or more of the following: a layer containing a material with high hole injection properties (hole injection layer), a layer containing a material with high hole transport properties (hole transport layer), and a layer containing a material with high electron blocking properties (electron blocking layer). Similarly, layer 790 has one or more of the following: a layer containing a material with high electron injection properties (electron injection layer), a layer containing a material with high electron transport properties (electron transport layer), and a layer containing a material with high hole blocking properties (hole blocking layer). When the lower electrode 761 is the cathode and the upper electrode 762 is the anode, layers 780 and 790 have the opposite configurations to those described above.

[0489] A configuration having a layer 780, an emissive layer 771, and a layer 790 provided between a pair of electrodes can function as a single emissive unit, and in this specification, the configuration shown in Figure 21A is referred to as a single structure.

[0490] Furthermore, Figure 21B shows a modified example of the EL layer 763 of the light-emitting element shown in Figure 21A. Specifically, the light-emitting element shown in Figure 21B has a layer 781 on the lower electrode 761, a layer 782 on the layer 781, a light-emitting layer 771 on the layer 782, a layer 791 on the light-emitting layer 771, a layer 792 on the layer 791, and an upper electrode 762 on the layer 792.

[0491] When the lower electrode 761 is the anode and the upper electrode 762 is the cathode, for example, layer 781 can be a hole injection layer, layer 782 a hole transport layer, layer 791 an electron transport layer, and layer 792 an electron injection layer. Also, when the lower electrode 761 is the cathode and the upper electrode 762 is the anode, layer 781 can be an electron injection layer, layer 782 an electron transport layer, layer 791 a hole transport layer, and layer 792 a hole injection layer. By using such a layer structure, carriers can be efficiently injected into the light-emitting layer 771, and the efficiency of carrier recombination within the light-emitting layer 771 can be increased.

[0492] As shown in Figures 21C and 21D, a configuration in which multiple light-emitting layers (light-emitting layer 771, light-emitting layer 772, light-emitting layer 773) are provided between layer 780 and layer 790 is also a variation of the single structure. Although Figures 21C and 21D show an example with three light-emitting layers, the light-emitting layers in a single-structure light-emitting element may be two or four or more. Furthermore, a single-structure light-emitting element may have a buffer layer between the two light-emitting layers.

[0493] Furthermore, as shown in Figures 21E and 21F, a configuration in which multiple light-emitting units (light-emitting units 763a and 763b) are connected in series via a charge generation layer 785 (also called an intermediate layer) is referred to as a tandem structure in this specification. The tandem structure may also be called a stacked structure. By using a tandem structure, a light-emitting element capable of high-brightness emission can be created. In addition, compared to a single structure, the tandem structure can reduce the current required to obtain the same brightness, thereby improving reliability.

[0494] Figures 21D and 21F show examples in which the display device has a layer 764 that overlaps with the light-emitting element. Figure 21D shows an example in which layer 764 overlaps with the light-emitting element shown in Figure 21C, and Figure 21F shows an example in which layer 764 overlaps with the light-emitting element shown in Figure 21E. In Figures 21D and 21F, a conductive film that transmits visible light is used for the upper electrode 762 in order to extract light to the upper electrode 762 side.

[0495] Layer 764 can be either a color conversion layer or a color filter (coloring layer), or both.

[0496] For example, if a single-structure light-emitting element has three light-emitting layers, it is preferable to have a light-emitting layer having a light-emitting material that emits red (R) light, a light-emitting layer having a light-emitting material that emits green (G) light, and a light-emitting layer having a light-emitting material that emits blue (B) light. The stacking order of the light-emitting layers can be R, G, B from the anode side, or R, B, G from the anode side, etc. In this case, a buffer layer may be provided between R and G or B.

[0497] Furthermore, for example, when a single-structure light-emitting element has two light-emitting layers, a configuration is preferred in which one light-emitting layer has a light-emitting material that emits blue (B) light, and the other light-emitting layer has a light-emitting material that emits yellow (Y) light. This configuration is sometimes referred to as a BY single structure.

[0498] A light-emitting element that emits white light preferably contains two or more types of light-emitting materials. To obtain white light emission, the light-emitting materials should be selected such that the light emitted by each of the two or more materials is complementary in color. For example, by making the light-emitting color of the first light-emitting layer and the light-emitting color of the second light-emitting layer complementary in color, a light-emitting element that emits white light as a whole can be obtained. The same applies to light-emitting elements that have three or more light-emitting layers.

[0499] In addition, in Figures 21C and 21D, as shown in Figure 21B, layer 780 and layer 790 may each be independently constructed as a laminated structure consisting of two or more layers.

[0500] Furthermore, when using light-emitting elements with the configuration shown in Figure 21E or Figure 21F for sub-pixels that emit light of each color, different light-emitting materials may be used for each sub-pixel. Specifically, in a light-emitting element of a sub-pixel that emits red light, light-emitting materials that emit red light may be used for both the light-emitting layer 771 and the light-emitting layer 772. Similarly, in a light-emitting element of a sub-pixel that emits green light, light-emitting materials that emit green light may be used for both the light-emitting layer 771 and the light-emitting layer 772. In a light-emitting element of a sub-pixel that emits blue light, light-emitting materials that emit blue light may be used for both the light-emitting layer 771 and the light-emitting layer 772. A display device with such a configuration can be said to have a tandem structure light-emitting element and an SBS structure. Therefore, it can combine the advantages of both the tandem structure and the SBS structure. This enables high-brightness light emission and realizes a highly reliable light-emitting element.

[0501] In Figures 21E and 21F, examples are shown in which the light-emitting unit 763a has one light-emitting layer 771 and the light-emitting unit 763b has one light-emitting layer 772, but the design is not limited to this. The light-emitting units 763a and 763b may each have two or more light-emitting layers.

[0502] Furthermore, while Figures 21E and 21F illustrate a light-emitting element having two light-emitting units, the light-emitting element is not limited to this. It may have three or more light-emitting units. The configuration with two light-emitting units may be called a two-stage tandem structure, and the configuration with three light-emitting units may be called a three-stage tandem structure.

[0503] Furthermore, in Figures 21E and 21F, the light-emitting unit 763a has layer 780a, light-emitting layer 771, and layer 790a, and the light-emitting unit 763b has layer 780b, light-emitting layer 772, and layer 790b.

[0504] When the lower electrode 761 is the anode and the upper electrode 762 is the cathode, layers 780a and 780b each have one or more of the following: a hole injection layer, a hole transport layer, and an electron blocking layer. Similarly, layers 790a and 790b each have one or more of the following: an electron injection layer, an electron transport layer, and a hole blocking layer. When the lower electrode 761 is the cathode and the upper electrode 762 is the anode, layers 780a and 790a have the opposite configurations to those described above, and layers 780b and 790b also have the opposite configurations to those described above.

[0505] When the lower electrode 761 is the anode and the upper electrode 762 is the cathode, for example, layer 780a has a hole injection layer and a hole transport layer on the hole injection layer, and may further have an electron blocking layer on the hole transport layer. Also, layer 790a has an electron transport layer and may further have a hole blocking layer between the light-emitting layer 771 and the electron transport layer. Also, layer 780b has a hole transport layer and may further have an electron blocking layer on the hole transport layer. Also, layer 790b has an electron transport layer and an electron injection layer on the electron transport layer, and may further have a hole blocking layer between the light-emitting layer 772 and the electron transport layer. When the lower electrode 761 is the cathode and the upper electrode 762 is the anode, for example, layer 780a has an electron injection layer and an electron transport layer on the electron injection layer, and may further have a hole blocking layer on the electron transport layer. Furthermore, layer 790a may have a hole transport layer and an electron blocking layer between the light-emitting layer 771 and the hole transport layer. Also, layer 780b may have an electron transport layer and an electron blocking layer on the electron transport layer. Furthermore, layer 790b may have a hole transport layer and a hole injection layer on the hole transport layer, and an electron blocking layer between the light-emitting layer 772 and the hole transport layer.

[0506] Furthermore, when fabricating a tandem light-emitting device, the two light-emitting units are stacked with a charge generation layer 785 in between. The charge generation layer 785 has at least a charge generation region. When a voltage is applied between the pair of electrodes, the charge generation layer 785 has the function of injecting electrons into one of the two light-emitting units and holes into the other.

[0507] Furthermore, an example of a tandem-structured light-emitting element is the configuration shown in Figures 22A to 22C.

[0508] Figure 22A shows a configuration having three light-emitting units. In Figure 22A, multiple light-emitting units (light-emitting units 763a, 763b, and 763c) are connected in series via a charge generation layer 785. Light-emitting unit 763a has layer 780a, light-emitting layer 771, and layer 790a; light-emitting unit 763b has layer 780b, light-emitting layer 772, and layer 790b; and light-emitting unit 763c has layer 780c, light-emitting layer 773, and layer 790c. Layer 780c can use a configuration applicable to layers 780a and 780b, and layer 790c can use a configuration applicable to layers 790a and 790b.

[0509] In Figure 22A, it is preferable that the light-emitting layers 771, 772, and 773 each have a light-emitting material that emits light of the same color. Specifically, the light-emitting layers 771, 772, and 773 can each have a red (R) light-emitting material (a so-called R\R\R three-stage tandem structure), the light-emitting layers 771, 772, and 773 can each have a green (G) light-emitting material (a so-called G\G\G three-stage tandem structure), or the light-emitting layers 771, 772, and 773 can each have a blue (B) light-emitting material (a so-called B\B\B three-stage tandem structure). Note that "a\b" means that a light-emitting unit having a light-emitting material has a light-emitting material that emits light a, and a light-emitting unit having a light-emitting material that emits light b is provided on the light-emitting unit having a light-emitting material via a charge generation layer, and a and b mean colors.

[0510] Furthermore, in Figure 22A, some or all of the light-emitting layers 771, 772, and 773 may be made of light-emitting materials that emit light of different colors. Examples of combinations of light-emitting colors for the light-emitting layers 771, 772, and 773 include a configuration in which two of them are blue (B) and the remaining one is yellow (Y), and a configuration in which one of them is red (R), another is green (G), and the remaining one is blue (B).

[0511] The light-emitting materials that each emit light of the same color are not limited to the above configuration. For example, as shown in Figure 22B, a tandem-type light-emitting element may be formed by stacking multiple light-emitting units having multiple light-emitting layers. Figure 22B shows a configuration in which two light-emitting units (light-emitting unit 763a and light-emitting unit 763b) are connected in series via a charge-generating layer 785. Light-emitting unit 763a has layer 780a, light-emitting layers 771a, 771b, and 771c, and layer 790a, while light-emitting unit 763b has layer 780b, light-emitting layers 772a, 772b, and 772c, and layer 790b.

[0512] In Figure 22B, complementary luminescent materials are selected for luminescent layers 771a, 771b, and 771c, and the luminescent unit 763a is configured to emit white light (W). Similarly, complementary luminescent materials are selected for luminescent layers 772a, 772b, and 772c, and the luminescent unit 763b is configured to emit white light (W). In other words, the configuration shown in Figure 22B is a two-stage tandem structure of W\W. There are no particular restrictions on the stacking order of complementary luminescent materials. The implementer can select the optimal stacking order as appropriate. In addition, although not shown, a three-stage tandem structure of W\W\W or a tandem structure of four or more stages may also be used.

[0513] Furthermore, when using a tandem light-emitting element, there are two-stage tandem structures of B\Y or Y\B having a light-emitting unit that emits yellow (Y) light and a light-emitting unit that emits blue (B) light, two-stage tandem structures of R·G\B or B\R·G having a light-emitting unit that emits red (R) and green (G) light and a light-emitting unit that emits blue (B) light, and a light-emitting unit that emits blue (B) light, a light-emitting unit that emits yellow (Y) light and a light-emitting unit that emits blue (B) light Examples include a three-stage tandem structure B\Y\B having a light-emitting unit and a light-emitting unit in this order, a three-stage tandem structure B\YG\B having a light-emitting unit that emits blue (B) light, a light-emitting unit that emits yellow-green (YG) light, and a light-emitting unit that emits blue (B) light in this order, and a three-stage tandem structure B\G\B having a light-emitting unit that emits blue (B) light, a light-emitting unit that emits green (G) light, and a light-emitting unit that emits blue (B) light in this order. Note that "a·b" means that one light-emitting unit has a light-emitting material that emits light a and a light-emitting material that emits light b.

[0514] Furthermore, as shown in Figure 22C, a light-emitting unit having one light-emitting layer and a light-emitting unit having multiple light-emitting layers may be combined.

[0515] Specifically, in the configuration shown in Figure 22C, multiple light-emitting units (light-emitting units 763a, 763b, and 763c) are connected in series via a charge generation layer 785. Furthermore, light-emitting unit 763a has a layer 780a, a light-emitting layer 771, and a layer 790a; light-emitting unit 763b has a layer 780b, a light-emitting layer 772a, a light-emitting layer 772b, a light-emitting layer 772c, and a layer 790b; and light-emitting unit 763c has a layer 780c, a light-emitting layer 773, and a layer 790c.

[0516] For example, in the configuration shown in Figure 22C, a three-stage tandem structure of B\R·G·YG\B can be applied, where light-emitting unit 763a is a light-emitting unit that emits blue (B) light, light-emitting unit 763b is a light-emitting unit that emits red (R), green (G), and yellow-green (YG) light, and light-emitting unit 763c is a light-emitting unit that emits blue (B) light.

[0517] For example, the number of layers and color order of the light-emitting unit can be, from the anode side, a two-layer structure of B and Y, a two-layer structure of B and light-emitting unit X, a three-layer structure of B, Y, B, or a three-layer structure of B, X, B. The number of layers and color order of the light-emitting layers in light-emitting unit X can be, from the anode side, a two-layer structure of R and Y, a two-layer structure of R and G, a two-layer structure of G and R, a three-layer structure of G, R, G, or a three-layer structure of R, G, R. In addition, other layers may be provided between the two light-emitting layers.

[0518] Next, we will describe the materials that can be used in light-emitting devices.

[0519] Of the lower electrode 761 and upper electrode 762, the electrode that extracts light preferably uses a conductive film that transmits visible light. Furthermore, it is preferable to use a conductive film that reflects visible light on the electrode that does not extract light. In addition, if the display device has a light-emitting element that emits infrared light, it is preferable to use a conductive film that transmits both visible light and infrared light on the electrode that extracts light, and a conductive film that reflects both visible light and infrared light on the electrode that does not extract light.

[0520] Furthermore, a conductive film that transmits visible light may also be used on the electrode that does not extract light. In this case, it is preferable to place the electrode between the reflective layer and the EL layer 763. In other words, the light emitted from the EL layer 763 may be reflected by the reflective layer and extracted from the display device.

[0521] As the material for forming the pair of electrodes of the light-emitting element, metals, alloys, electrically conductive compounds, and mixtures thereof can be used as appropriate. Specifically, such materials include metals such as aluminum, titanium, chromium, manganese, iron, cobalt, nickel, copper, gallium, zinc, indium, tin, molybdenum, tantalum, tungsten, palladium, gold, platinum, silver, yttrium, and neodymium, and alloys containing these in appropriate combinations. Other examples of such materials include indium tin oxide (In-Sn oxide, also called ITO), In-Si-Sn oxide (also called ITSO), indium zinc oxide (In-Zn oxide), and In-W-Zn oxide. Furthermore, other examples of such materials include aluminum-containing alloys such as aluminum, nickel, and lanthanum alloys (Al-Ni-La), and silver, palladium, and copper alloys (Ag-Pd-Cu, also written as APC). Other materials include elements belonging to Group 1 or Group 2 of the periodic table not exemplified above (e.g., lithium, cesium, calcium, strontium), rare earth metals such as europium and ytterbium, alloys containing these in appropriate combinations, graphene, and the like.

[0522] It is preferable that the light-emitting element has a microcavity structure. Therefore, it is preferable that one of the pair of electrodes in the light-emitting element is a semitransmitting / semi-reflective electrode that transmits and reflects visible light, and the other is a reflective electrode that reflects visible light. By having a microcavity structure in the light-emitting element, the light emitted from the light-emitting layer can be resonated between the two electrodes, thereby strengthening the light emitted from the light-emitting element.

[0523] Furthermore, the semi-transparent / semi-reflective electrode can have a laminated structure consisting of a conductive layer that can be used as a reflective electrode and a conductive layer that can be used as an electrode that transmits visible light (also called a transparent electrode).

[0524] The light transmittance of the transparent electrode shall be 40% or more. For example, it is preferable to use an electrode with a transmittance of 40% or more for visible light (light with a wavelength of 400 nm or more and less than 750 nm) for the transparent electrode of the light-emitting element. The visible light reflectance of the semi-transparent / semi-reflective electrode shall be 10% or more and 95% or less, preferably 30% or more and 80% or less. The visible light reflectance of the reflective electrode shall be 40% or more and 100% or less, preferably 70% or more and 100% or less. The resistivity of these electrodes shall be 1 × 10⁻⁶ -2 A value of Ωcm or less is preferable.

[0525] A light-emitting element has at least a light-emitting layer. Furthermore, the light-emitting element may also have layers other than the light-emitting layer, such as a material with high hole injection properties, a material with high hole transport properties, a hole-blocking material, a material with high electron transport properties, an electron-blocking material, a material with high electron injection properties, or a bipolar material (a material with high electron and hole transport properties). For example, a light-emitting element can have a configuration that includes, in addition to the light-emitting layer, one or more layers from among a hole injection layer, a hole transport layer, a hole-blocking layer, a charge generation layer, an electron-blocking layer, an electron transport layer, and an electron injection layer.

[0526] The light-emitting element can be made of either low-molecular-weight compounds or high-molecular-weight compounds, and may also contain inorganic compounds. The layers constituting the light-emitting element can be formed by methods such as vapor deposition (including vacuum deposition), transfer, printing, inkjet, and coating.

[0527] The light-emitting layer contains one or more types of light-emitting materials. The light-emitting materials may include those exhibiting colors such as blue, purple, blue-violet, green, yellow-green, yellow, orange, or red. Furthermore, materials emitting near-infrared light may also be used as light-emitting materials.

[0528] Examples of luminescent materials include fluorescent materials, phosphorescent materials, TADF materials, and quantum dot materials.

[0529] Examples of fluorescent materials include pyrene derivatives, anthracene derivatives, triphenylene derivatives, fluorene derivatives, carbazole derivatives, dibenzothiophene derivatives, dibenzofuran derivatives, dibenzoquinoxaline derivatives, quinoxaline derivatives, pyridine derivatives, pyrimidine derivatives, phenanthrene derivatives, and naphthalene derivatives.

[0530] Examples of phosphorescent materials include organometallic complexes (especially iridium complexes) having a 4H-triazole skeleton, 1H-triazole skeleton, imidazole skeleton, pyrimidine skeleton, pyrazine skeleton, or pyridine skeleton; organometallic complexes (especially iridium complexes) using phenylpyridine derivatives having electron-withdrawing groups as ligands; platinum complexes; and rare earth metal complexes.

[0531] The light-emitting layer may contain one or more types of organic compounds (host material, assist material, etc.) in addition to the light-emitting substance (guest material). One or more types of organic compounds may include materials with high hole transport properties (hole transport materials) and / or materials with high electron transport properties (electron transport materials). As the hole transport material, one of the materials with high hole transport properties that can be used in the hole transport layer, as described later, may be used. As the electron transport material, one of the materials with high electron transport properties that can be used in the electron transport layer, as described later, may be used. Furthermore, one or more types of organic compounds may include bipolar materials or TADF materials.

[0532] The light-emitting layer preferably comprises, for example, a phosphorescent material and a combination of a hole-transporting material and an electron-transporting material that readily forms an excitation complex. With such a configuration, light emission using ExTET (Exciplex-Triplet Energy Transfer), which is energy transfer from the excitation complex to the light-emitting substance (phosphorescent material), can be efficiently obtained. By selecting a combination that forms an excitation complex that exhibits light emission at a wavelength overlapping with the wavelength of the lowest-energy absorption band of the light-emitting substance, energy transfer becomes smoother, and light emission can be efficiently obtained. This configuration enables high efficiency, low-voltage operation, and long lifespan of the light-emitting device simultaneously.

[0533] The hole injection layer is a layer that injects holes from the anode into the hole transport layer, and is a layer containing a material with high hole injection capabilities. Examples of materials with high hole injection capabilities include aromatic amine compounds and composite materials containing hole transport materials and acceptor materials (electron-accepting materials).

[0534] As the hole-transporting material, a material with high hole-transporting properties that can be used in the hole-transporting layer, as described later, can be used.

[0535] As acceptor materials, for example, oxides of metals belonging to groups 4 through 8 of the periodic table can be used. Specifically, these include molybdenum oxide, vanadium oxide, niobium oxide, tantalum oxide, chromium oxide, tungsten oxide, manganese oxide, and rhenium oxide. Among these, molybdenum oxide is particularly preferred because it is stable in the atmosphere, has low hygroscopicity, and is easy to handle. Organic acceptor materials containing fluorine can also be used. Furthermore, organic acceptor materials such as quinodimethane derivatives, chloranil derivatives, and hexaazatriphenylene derivatives can also be used.

[0536] For example, as a material with high hole injection properties, a material containing a hole transport material and an oxide of a metal belonging to Group 4 to Group 8 of the periodic table (typically molybdenum oxide) may be used.

[0537] The hole transport layer is a layer that transports holes injected from the anode by the hole injection layer to the light-emitting layer. The hole transport layer is a layer containing a hole-transporting material. The hole-transporting material is 1 × 10⁻¹⁶ -6 cm 2 Materials having a hole mobility of / Vs or higher are preferred. However, other materials can also be used as long as they have higher hole transport capabilities than electron transport. Preferred hole transport materials include π-electron-rich heteroaromatic compounds (e.g., carbazole derivatives, thiophene derivatives, furan derivatives, etc.) and aromatic amines (compounds having an aromatic amine skeleton), which are materials with high hole transport capabilities.

[0538] The electron blocking layer is provided in contact with the light-emitting layer. The electron blocking layer is a layer containing a material that has hole-transporting properties and is capable of blocking electrons. Among the hole-transporting materials mentioned above, a material with electron-blocking properties can be used for the electron blocking layer.

[0539] Because electron-blocking layers possess hole-transporting properties, they can also be called hole-transporting layers. Furthermore, among hole-transporting layers, those that exhibit electron-blocking properties can also be called electron-blocking layers.

[0540] The electron transport layer is a layer that transports electrons injected from the cathode by the electron injection layer to the light-emitting layer. The electron transport layer is a layer containing an electron-transporting material. The electron-transporting material is 1 × 10⁻¹⁶ -6 cm 2Materials having an electron mobility of / Vs or higher are preferred. However, other materials can also be used as long as they have higher electron transport capabilities than holes. Examples of electron-transporting materials include metal complexes having a quinoline skeleton, metal complexes having a benzoquinoline skeleton, metal complexes having an oxazole skeleton, metal complexes having a thiazole skeleton, as well as oxadiazole derivatives, triazole derivatives, imidazole derivatives, oxazole derivatives, thiazole derivatives, phenanthroline derivatives, quinoline derivatives having a quinoline ligand, benzoquinoline derivatives, quinoxaline derivatives, dibenzoquinoxaline derivatives, pyridine derivatives, bipyridine derivatives, pyrimidine derivatives, and other π-electron-deficient heteroaromatic compounds containing nitrogen-containing heteroaromatic compounds.

[0541] The hole-blocking layer is provided in contact with the light-emitting layer. The hole-blocking layer is a layer containing a material that has electron-transporting properties and is capable of blocking holes. Among the electron-transporting materials mentioned above, a material that has hole-blocking properties can be used for the hole-blocking layer.

[0542] Because hole-blocking layers possess electron-transporting properties, they can also be called electron-transporting layers. Furthermore, among electron-transporting layers, those that exhibit hole-blocking properties can also be called hole-blocking layers.

[0543] The electron injection layer is a layer that injects electrons from the cathode to the electron transport layer, and is a layer containing a material with high electron injection capabilities. Alkali metals, alkaline earth metals, or compounds thereof can be used as materials with high electron injection capabilities. Composite materials containing both electron transport materials and donor materials (electron-donating materials) can also be used as materials with high electron injection capabilities.

[0544] Furthermore, it is preferable that the lowest unoccupied molecular orbital (LUMO) level of a material with high electron injection potential has a small difference (specifically, 0.5 eV or less) from the work function value of the material used as the cathode.

[0545] The electron injection layer contains, for example, lithium, cesium, ytterbium, lithium fluoride (LiF), cesium fluoride (CsF), and calcium fluoride (CaF). x (where X is any number), 8-(quinolinolato)lithium (abbreviation: Liq), 2-(2-pyridyl)phenolatrium (abbreviation: LiPP), 2-(2-pyridyl)-3-pyridinolatrium (abbreviation: LiPPy), 4-phenyl-2-(2-pyridyl)phenolatrium (abbreviation: LiPPP), lithium oxide (LiO x Alkali metals such as cesium carbonate, alkaline earth metals, or compounds thereof can be used. The electron injection layer may also be a multilayer structure of two or more layers. For example, a multilayer structure in which lithium fluoride is used as the first layer and ytterbium is provided as the second layer can be used.

[0546] The electron injection layer may contain an electron-transporting material. For example, a compound having a lone pair of electrons and an electron-deficient heteroaromatic ring can be used as the electron-transporting material. Specifically, a compound having at least one of a pyridine ring, a diazine ring (pyrimidine ring, pyrazine ring, pyridazine ring), or a triazine ring can be used.

[0547] Furthermore, the LUMO level of organic compounds containing lone pairs of electrons is preferably between -3.6 eV and -2.3 eV. In general, the highest occupied molecular orbital (HOMO) level and the LUMO level of organic compounds can be estimated by methods such as cyclic voltammetry (CV), photoelectron spectroscopy, optical absorption spectroscopy, and inverse photoelectron spectroscopy.

[0548] For example, 4,7-diphenyl-1,10-phenanthroline (abbreviated as BPhen), 2,9-di(naphthalene-2-yl)-4,7-diphenyl-1,10-phenanthroline (abbreviated as NBPhen), 2,2-(1,3-phenylene)bis[9-phenyl-1,10-phenanthroline] (abbreviated as mPPhen2P), diquinoxalino[2,3-a:2',3'-c]phenazine (abbreviated as HATNA), and 2,4,6-tris[3'-(pyridine-3-yl)biphenyl-3-yl]-1,3,5-triazine (abbreviated as TmPPPyTz) can be used in organic compounds containing lone pairs of electrons. NBPhen has a higher glass transition temperature (Tg) and superior heat resistance compared to BPhen.

[0549] As described above, the charge generation layer has at least a charge generation region. The charge generation region preferably contains an acceptor material, and preferably contains, for example, a hole transport material and an acceptor material applicable to the hole injection layer described above.

[0550] Furthermore, the charge generation layer preferably includes a layer containing a material with high electron injection potential. This layer can also be called an electron injection buffer layer. The electron injection buffer layer is preferably provided between the charge generation region and the electron transport layer. By providing an electron injection buffer layer, the injection barrier between the charge generation region and the electron transport layer can be relaxed, allowing electrons generated in the charge generation region to be easily injected into the electron transport layer.

[0551] The electron injection buffer layer preferably contains an alkali metal or an alkaline earth metal, and can, for example, a compound of an alkali metal or an alkaline earth metal. Specifically, the electron injection buffer layer preferably has an inorganic compound containing an alkali metal and oxygen, or an inorganic compound containing an alkaline earth metal and oxygen, and more preferably has an inorganic compound containing lithium and oxygen (such as lithium oxide (Li2O)). In addition, any other material applicable to the electron injection layer can be suitably used for the electron injection buffer layer.

[0552] The charge generation layer preferably has a layer containing a material with high electron transport properties. This layer can also be called an electron relay layer. The electron relay layer is preferably provided between the charge generation region and the electron injection buffer layer. If the charge generation layer does not have an electron injection buffer layer, the electron relay layer is preferably provided between the charge generation region and the electron transport layer. The electron relay layer has the function of preventing interaction between the charge generation region and the electron injection buffer layer (or electron transport layer) and smoothly transferring electrons.

[0553] As the electron relay layer, it is preferable to use a phthalocyanine-based material such as copper(II) phthalocyanine (abbreviated as CuPc), or a metal complex having a metal-oxygen bond and an aromatic ligand.

[0554] Furthermore, the charge generation region, electron injection buffer layer, and electron relay layer described above may not be clearly distinguishable depending on their cross-sectional shape or characteristics.

[0555] The charge generation layer may have a donor material instead of an acceptor material. For example, the charge generation layer may have a layer containing an electron transport material and a donor material, which is applicable to the electron injection layer described above.

[0556] When stacking light-emitting units, the rise in driving voltage can be suppressed by providing a charge generation layer between the two light-emitting units.

[0557] Next, the functions of the display device 100 having light-emitting elements 110R, 110G, 110B, and a light-receiving element 110S will be explained using the schematic diagram shown in Figure 23A. Here, the light-emitting element 110R emits red light (R), the light-emitting element 110G emits green light (G), and the light-emitting element 110B emits blue light (B). Furthermore, light-emitting elements 110R, 110G, and 110B can each correspond to one of the light-emitting elements 110a, 110b, and 110c shown in Figure 19A, etc.

[0558] Figure 23A shows how a finger 190 touches the surface of the substrate 102. The substrate 102 can be the same as the substrate 170 shown in Embodiment 2. A portion of the light emitted by the light-emitting element 110 (for example, the light emitted by the light-emitting element 110G) is reflected at the contact point between the substrate 102 and the finger 190. A portion of this reflected light is then incident on the light-receiving element 110S, allowing the device to sense that the finger 190 has contacted the substrate 102. In this way, the display device 100 can detect the fingerprint of the finger 190 and perform personal authentication.

[0559] Here, Figure 23C schematically shows an enlarged view of the contact area when the finger 190 is touching the substrate 102. Figure 23C also shows the alternating arrangement of light-emitting elements 110 and light-receiving elements 110S.

[0560] Fingerprints are formed on finger 190 by recesses and protrusions. Therefore, as shown in Figure 23C, the protrusions of the fingerprints are in contact with the substrate 102.

[0561] Light reflected from a surface or interface can be either specular or diffuse. Specularly reflected light is highly directional, with the angle of incidence and the angle of reflection being the same, while diffusely reflected light is less directional, with low angular dependence of intensity. The light reflected from the surface of finger 190 is predominantly diffuse. On the other hand, the light reflected from the interface between substrate 102 and the atmosphere is predominantly specular.

[0562] The intensity of light reflected from the contact or non-contact surface between the finger 190 and the substrate 102, and incident on the photodetector 110S located directly beneath them, is the sum of specular reflection and diffuse reflection. As described above, in the recessed areas of the finger 190, the substrate 102 and the finger 190 do not come into contact, so specular reflection (indicated by the solid arrow) is dominant, while in the convex areas, they come into contact, so diffuse reflection from the finger 190 (indicated by the dashed arrow) is dominant. Therefore, the intensity of light received by the photodetector 110S located directly beneath the recessed areas is higher than that of the photodetector 110S located directly beneath the convex areas. This allows for imaging of the fingerprint of the finger 190.

[0563] The spacing between the light-receiving elements 110S is set to be smaller than the distance between two protrusions of a fingerprint, preferably the distance between adjacent recesses and protrusions, thereby enabling the acquisition of a clear fingerprint image. Since the distance between recesses and protrusions in a human fingerprint is approximately 200 μm, for example, the spacing between the light-receiving elements 110S is 400 μm or less, preferably 200 μm or less, more preferably 150 μm or less, even more preferably 100 μm or less, and even more preferably 50 μm or less, and 1 μm or more, preferably 10 μm or more, and more preferably 20 μm or more.

[0564] Figure 23D shows an example of a fingerprint image captured by the display device 100. In Figure 23D, the outline of the finger 190 is shown with a dashed line and the outline of the contact area 191 is shown with a dashed line within the imaging range 193. Within the contact area 191, a high-contrast fingerprint 192 can be captured due to the difference in the amount of light incident on the light-receiving element 110S.

[0565] Note that while Figure 23A shows an example where the finger 190 is in contact with the substrate 102, the finger 190 does not necessarily need to be in contact with the substrate 102. For example, as shown in Figure 23B, sensing may be possible even when the finger 190 and the substrate 102 are separated. However, in this case, it is preferable that the distance between the finger 190 and the substrate 102 is relatively close, and this state is sometimes called near touch or hover touch.

[0566] In this specification, near touch or hover touch refers to a state in which, for example, an object (finger 190) can be detected without the object (finger 190) making contact with the display device. For example, it is preferable that the display device can detect the object (finger 190) when the distance between the display device and the object (finger 190) is in the range of 0.1 mm to 300 mm, preferably 3 mm to 50 mm. With this configuration, it becomes possible to operate the display device without the object (finger 190) directly touching it, in other words, it becomes possible to operate the display device without contact (touchless). With the above configuration, the risk of the display device becoming dirty or scratched can be reduced, or it becomes possible to operate the display device without the object (finger 190) directly touching any dirt (e.g., dust or viruses) that may adhere to the display device.

[0567] Figures 24A to 24E show examples of light-receiving element configurations that can be applied to display devices. Components shown in Figures 24A to 24E that are the same as those shown in Figure 21 are denoted by the same reference numerals.

[0568] The photodetector shown in Figure 24A has a PS layer 787 between a pair of electrodes (lower electrode 761, upper electrode 762). The lower electrode 761 functions as a pixel electrode and is provided for each photodetector. The upper electrode 762 functions as a common electrode and is provided in common to multiple light-emitting elements and photodetectors.

[0569] As shown in Figure 24A, the PS layer 787 can be formed as island-like layers. In other words, the PS layer 787 shown in Figure 24A corresponds to the PS layer 155S shown in Figure 2B, etc. The photodetector corresponds to the photodetector 110S. The lower electrode 761 corresponds to the pixel electrode 111S. The upper electrode 762 corresponds to the common electrode 113.

[0570] The PS layer 787 includes layers 781, 782, a photoelectric conversion layer 783, 791, 792, etc. Layers 781, 782, 791, and 792 are the same as those used in the light-emitting element. Here, layer 792 and the upper electrode 762 can be provided in common to both the light-emitting element and the light-receiving element.

[0571] The photoelectric conversion layer 783 includes a semiconductor. Examples of such semiconductors include inorganic semiconductors such as silicon, and organic semiconductors containing organic compounds. In this embodiment, an example is shown in which an organic semiconductor is used as the semiconductor in the photoelectric conversion layer 783. Using an organic semiconductor is preferable because the light-emitting layer and the photoelectric conversion layer 783 can be formed using the same method (for example, vacuum deposition), and the manufacturing equipment can be shared.

[0572] For example, a pn-type or pin-type photodiode can be used as the photoelectric conversion layer 783. The n-type semiconductor material and the p-type semiconductor material that can be used as the photoelectric conversion layer 783 are shown below. The n-type semiconductor material and the p-type semiconductor material may be used stacked in layers, or they may be mixed and used as a single layer.

[0573] The n-type semiconductor material of the photoelectric conversion layer 783 is fullerene (for example, C 60 , C 70 Examples include electron-accepting organic semiconductor materials such as fullerene derivatives. Fullerenes have a shape like a soccer ball, and this shape is energetically stable. Both the HOMO and LUMO levels of fullerenes are deep (low). Because the LUMO level of fullerenes is deep, they have extremely high electron-accepting properties. Normally, when π-electron conjugation (resonance) spreads out in a plane, as in benzene, electron-donating properties increase, but because fullerenes have a spherical shape, they have high electron-accepting properties despite the large spread of π-electron conjugation. High electron-accepting properties allow for fast and efficient charge separation, making them useful as photodetectors. 60 , C 70 Both have a broad absorption band in the visible light region, and especially C 70 is C 60 Compared to [6,6]-Phenyl-C, it is preferable because it has a larger π-electron conjugation system and a broad absorption band in the long-wavelength region. In addition, [6,6]-Phenyl-C is a suitable fullerene derivative. 71-butyric acid methyl ester (abbreviation: PC70BM), [6,6]-Phenyl-C 61 -butyric acid methyl ester (abbreviation: PC60BM), 1',1'',4',4''-Tetrahydro-di[1,4]methanonaphthaleno[1,2:2',3',56,60:2'',3''][5,6]fulrerene-C 60 Examples include (abbreviated as ICBA).

[0574] Furthermore, examples of n-type semiconductor materials include perylenetetracarboxylic acid derivatives such as N,N'-dimethyl-3,4,9,10-perylenetetracarboxylic acid diimide (abbreviated as Me-PTCDI).

[0575] Furthermore, an example of an n-type semiconductor material is 2,2'-(5,5'-(thieno[3,2-b]thiophene-2,5-diyl)bis(thiophene-5,2-diyl))bis(methane-1-yl-1-ylidene)dimalonitrile (abbreviation: FT2TDMN).

[0576] Furthermore, examples of n-type semiconductor materials include metal complexes having a quinoline skeleton, metal complexes having a benzoquinoline skeleton, metal complexes having an oxazole skeleton, metal complexes having a thiazole skeleton, oxadiazole derivatives, triazole derivatives, imidazole derivatives, oxazole derivatives, thiazole derivatives, phenanthroline derivatives, quinoline derivatives, benzoquinoline derivatives, quinoxaline derivatives, dibenzoquinoxaline derivatives, pyridine derivatives, bipyridine derivatives, pyrimidine derivatives, naphthalene derivatives, anthracene derivatives, coumarin derivatives, rhodamine derivatives, triazine derivatives, and quinone derivatives.

[0577] Examples of p-type semiconductor materials for the photoelectric conversion layer 783 include electron-donating organic semiconductor materials such as copper(II) phthalocyanine (CuPc), tetraphenyldibenzoperiflanthene (DBP), zinc phthalocyanine (ZnPc), tin phthalocyanine (SnPc), quinacridone, and rubrene.

[0578] Furthermore, examples of p-type semiconductor materials include carbazole derivatives, thiophene derivatives, furan derivatives, and compounds having an aromatic amine skeleton. In addition, examples of p-type semiconductor materials include naphthalene derivatives, anthracene derivatives, pyrene derivatives, triphenylene derivatives, fluorene derivatives, pyrrole derivatives, benzofuran derivatives, benzothiophene derivatives, indole derivatives, dibenzofuran derivatives, dibenzothiophene derivatives, indolocarbazole derivatives, porphyrin derivatives, phthalocyanine derivatives, naphthalocyanine derivatives, quinacridone derivatives, rubrene derivatives, tetracene derivatives, polyphenylenevinylene derivatives, polyparaphenylene derivatives, polyfluorene derivatives, polyvinylcarbazole derivatives, and polythiophene derivatives.

[0579] The HOMO level of electron-donating organic semiconductor materials is preferably shallower (higher) than the HOMO level of electron-accepting organic semiconductor materials. The LUMO level of electron-donating organic semiconductor materials is preferably shallower (higher) than the LUMO level of electron-accepting organic semiconductor materials.

[0580] It is preferable to use spherical fullerenes as electron-accepting organic semiconductor materials and organic semiconductor materials with a near-planar shape as electron-donating organic semiconductor materials. Molecules with similar shapes tend to aggregate, and when molecules of the same type aggregate, their molecular orbital energy levels are close, which can improve carrier transport.

[0581] For example, the photoelectric conversion layer 783 is preferably formed by co-depositing an n-type semiconductor and a p-type semiconductor. Alternatively, the photoelectric conversion layer 783 may be formed by stacking an n-type semiconductor and a p-type semiconductor.

[0582] The light-emitting element and the light-receiving element may use either low-molecular-weight compounds or high-molecular-weight compounds, and may also contain inorganic compounds. The layers constituting the light-emitting element and the light-receiving element can be formed by methods such as vapor deposition (including vacuum deposition), transfer, printing, inkjet, and coating.

[0583] For example, polymer compounds such as poly(3,4-ethylenedioxythiophene) / poly(styrenesulfonic acid) (PEDOT / PSS), and inorganic compounds such as molybdenum oxide and copper iodide (CuI) can be used as hole transport materials or electron blocking materials. In addition, inorganic compounds such as zinc oxide (ZnO) and organic compounds such as polyethyleneimine ethoxylate (PEIE) can be used as electron transport materials or hole blocking materials. The photodetector may have, for example, a mixed film of PEIE and ZnO.

[0584] Furthermore, the photoelectric conversion layer 783 can use polymer compounds such as Poly[[4,8-bis[5-(2-ethylhexyl)-2-thienyl]benzo[1,2-b:4,5-b']dithiophene-2,6-diyl]-2,5-thiophenediyl[5,7-bis(2-ethylhexyl)-4,8-dioxo-4H,8H-benzo[1,2-c:4,5-c']dithiophene-1,3-diyl]]polymer (abbreviated as PBDB-T) or PBDB-T derivatives, which function as donors. For example, a method of dispersing an acceptor material in PBDB-T or a PBDB-T derivative can be used.

[0585] Furthermore, the photoelectric conversion layer 783 may contain a mixture of three or more materials. For example, to expand the wavelength range, a third material may be mixed with an n-type semiconductor material and a p-type semiconductor material. In this case, the third material may be a low-molecular-weight compound or a high-molecular-weight compound.

[0586] As shown in Figure 24A, the PS layer 787 can be stacked in the order of layer 781 (hole injection layer), layer 782 (hole transport layer), photoelectric conversion layer 783, layer 791 (electron transport layer), and layer 792 (electron injection layer). This is the same stacking order as the EL layer 763 shown in Figure 21B. In this case, in both the light-emitting element and the photodetector, the lower electrode 761 can function as the anode and the upper electrode 762 can function as the cathode. In other words, by driving the photodetector with a reverse bias applied between the lower electrode 761 and the upper electrode 762, the photodetector can detect light incident on the photodetector, generate charge, and extract it as current.

[0587] However, the present invention is not limited thereto. For example, layer 781 may have an electron injection layer, layer 782 may have an electron transport layer, layer 791 may have a hole transport layer, and layer 792 may have a hole injection layer. In this case, the lower electrode 761 of the photodetector may function as the cathode and the upper electrode 762 may function as the anode. As shown in the above embodiment, in the present invention, the light-emitting element and the photodetector can be formed individually. For this reason, even if the configurations of the light-emitting element and the photodetector are significantly different, they can be manufactured relatively easily.

[0588] Furthermore, it is not necessary to provide all of the layers 781, 782, 791, and 792 shown in Figure 24A. For example, as shown in Figure 24B, the layer 781 having the hole injection layer may be omitted, and the layer 782 having the hole injection layer may be in contact with the lower electrode 761. It is preferable to provide at least one of the layer 782 having the hole transport layer and the layer 791 having the electron transport layer in contact with the photoelectric conversion layer 783, as shown in Figures 24A and 24B. This helps to suppress the occurrence of leakage current between the lower electrode 761 and the upper electrode 762 in the photodetector, which would reduce the imaging sensitivity.

[0589] Furthermore, it is also possible to omit either layer 782 or layer 791. For example, as shown in Figure 24C, the photoelectric conversion layer 783 may be in contact with layer 792 without providing layer 791, which has an electron transport layer.

[0590] Furthermore, the PS layer 787 can also consist only of the photoelectric conversion layer 783. For example, as shown in Figure 24D, the photoelectric conversion layer 783 may be in contact with the lower electrode 761 without providing the hole transport layer 782.

[0591] Furthermore, if layer 792 is not a common layer but is provided for each light-emitting element, it is also possible to have a configuration in which layer 792 is not provided for the light-receiving element. For example, as shown in Figure 24E, a configuration may be made in which the photoelectric conversion layer 783 is in contact with the upper electrode 762 without providing layer 792 which has an electron injection layer.

[0592] This embodiment can be combined with other embodiments as appropriate.

[0593] (Embodiment 4) This embodiment describes an electronic device according to one aspect of the present invention.

[0594] The electronic device of this embodiment has a display device according to one aspect of the present invention in its display unit. The display device according to one aspect of the present invention is easily made high-definition and high-resolution. Therefore, it can be used in the display units of various electronic devices.

[0595] Examples of electronic devices include television sets, desktop or notebook personal computers, computer monitors, digital signage, and large game machines such as pachinko machines, as well as electronic devices with relatively large screens, digital cameras, digital video cameras, digital photo frames, mobile phones, portable game consoles, personal digital assistants, and audio playback devices.

[0596] In particular, a display device according to one aspect of the present invention can be used suitably in electronic devices having a relatively small display area because it can increase the resolution. Examples of such electronic devices include wristwatch-type and bracelet-type information terminals (wearable devices), as well as wearable devices that can be worn on the head, such as head-mounted displays for VR, glasses-type devices for AR, and devices for MR.

[0597] A display device according to one aspect of the present invention preferably has an extremely high resolution such as HD (1280 x 720 pixels), FHD (1920 x 1080 pixels), WQHD (2560 x 1440 pixels), WQXGA (2560 x 1600 pixels), 4K (3840 x 2160 pixels), or 8K (7680 x 4320 pixels). In particular, a resolution of 4K, 8K, or higher is preferred. Furthermore, the pixel density (resolution) of the display device according to one aspect of the present invention is preferably 100 ppi or more, preferably 300 ppi or more, more preferably 500 ppi or more, more preferably 1000 ppi or more, more preferably 2000 ppi or more, more preferably 3000 ppi or more, more preferably 5000 ppi or more, and even more preferably 7000 ppi or more. By using a display device having either high resolution or high detail, or both, it becomes possible to further enhance the sense of presence and depth in personal electronic devices such as portable or home-use devices. Furthermore, there are no particular limitations on the screen ratio (aspect ratio) of the display device according to one embodiment of the present invention. For example, the display device can support various screen ratios such as 1:1 (square), 4:3, 16:9, and 16:10.

[0598] The electronic device of this embodiment may have sensors (including those with functions to measure force, displacement, position, velocity, acceleration, angular velocity, rotational speed, distance, light, liquid, magnetism, temperature, chemical substances, sound, time, hardness, electric field, current, voltage, power, radiation, flow rate, humidity, gradient, vibration, odor, or infrared radiation).

[0599] The electronic device of this embodiment can have various functions. For example, it can have a function to display various information (still images, videos, or text images, etc.) on a display unit, a touch panel function, a function to display a calendar, date, or time, a function to execute various software (programs), a wireless communication function, or a function to read programs or data recorded on a recording medium.

[0600] Figures 25A to 25D illustrate an example of a wearable device that can be worn on the head. These wearable devices have at least one of the following functions: a function to display AR content, a function to display VR content, a function to display SR content, and a function to display MR content. By having an electronic device that has the function to display at least one of the following content types, it is possible to enhance the user's sense of immersion.

[0601] The electronic device 700A shown in Figure 25A and the electronic device 700B shown in Figure 25B each include a pair of display panels 751, a pair of housings 721, a communication unit (not shown), a pair of mounting units 723, a control unit (not shown), an imaging unit (not shown), a pair of optical members 753, a frame 757, and a pair of nose pads 758.

[0602] A display device according to one embodiment of the present invention can be applied to the display panel 751. Therefore, an extremely high-resolution electronic device can be made.

[0603] Electronic devices 700A and 700B can project an image displayed on the display panel 751 onto the display area 756 of the optical element 753. Because the optical element 753 is translucent, the user can see the image displayed on the display area superimposed on the transmitted image visible through the optical element 753. Therefore, electronic devices 700A and 700B are electronic devices capable of AR display.

[0604] Electronic devices 700A and 700B may be equipped with cameras capable of capturing images of the area in front of them as imaging units. Furthermore, electronic devices 700A and 700B may each be equipped with acceleration sensors such as gyro sensors to detect the orientation of the user's head and display an image corresponding to that orientation in the display area 756.

[0605] The communications unit has a wireless communication device, which can supply, for example, a video signal. Alternatively, instead of the wireless communication device, or in addition to the wireless communication device, it may be equipped with a connector to which a cable for supplying video signals and power potential can be connected.

[0606] Furthermore, electronic devices 700A and 700B are equipped with batteries that can be charged wirelessly, wired, or both.

[0607] The housing 721 may be equipped with a touch sensor module. The touch sensor module has the function of detecting when the outer surface of the housing 721 is touched. The touch sensor module can detect the user's tap or slide operations and perform various processes. For example, a tap operation can be used to pause or resume the video, and a slide operation can be used to fast forward or rewind. Furthermore, by providing a touch sensor module in each of the two housings 721, the range of operations can be expanded.

[0608] Various types of touch sensors can be used in the touch sensor module. For example, various methods such as capacitive, resistive, infrared, electromagnetic induction, surface acoustic wave, or optical sensors can be employed. In particular, it is preferable to apply capacitive or optical sensors to the touch sensor module.

[0609] When using an optical touch sensor, a photoelectric conversion element (also called a photoelectric conversion device) can be used as the light-receiving element. The active layer of the photoelectric conversion element can be made of either an inorganic semiconductor or an organic semiconductor, or both.

[0610] The electronic device 800A shown in Figure 25C and the electronic device 800B shown in Figure 25D each include a pair of display units 820, a housing 821, a communication unit 822, a pair of mounting units 823, a control unit 824, a pair of imaging units 825, and a pair of lenses 832.

[0611] A display device according to one embodiment of the present invention can be applied to the display unit 820. Therefore, an extremely high-resolution electronic device can be made.

[0612] The display unit 820 is located inside the housing 821, in a position where it can be seen through the lens 832. Furthermore, by displaying different images on a pair of display units 820, a three-dimensional display using parallax can also be performed.

[0613] Electronic devices 800A and 800B can be described as electronic devices for VR. A user wearing electronic device 800A or electronic device 800B can view the image displayed on the display unit 820 through the lens 832.

[0614] It is preferable that electronic devices 800A and 800B each have a mechanism that allows the left and right positions of the lens 832 and the display unit 820 to be optimally positioned according to the user's eye position. It is also preferable that they have a mechanism that adjusts the focus by changing the distance between the lens 832 and the display unit 820.

[0615] The attachment portion 823 allows the user to attach the electronic device 800A or 800B to their head. Note that, for example, in Figure 25C, it is illustrated as having a shape similar to the temples (or arms, etc.) of eyeglasses, but it is not limited to this. The attachment portion 823 only needs to be wearable by the user; for example, it may be helmet-shaped or band-shaped.

[0616] The imaging unit 825 has the function of acquiring external information. The data acquired by the imaging unit 825 can be output to the display unit 820. An image sensor can be used in the imaging unit 825. In addition, multiple cameras may be provided to accommodate multiple angles of view, such as telephoto and wide-angle.

[0617] Although an example with an imaging unit 825 is shown here, any distance measuring sensor (also called a detection unit) capable of measuring the distance to an object can be provided. In other words, the imaging unit 825 is one form of the detection unit. As the detection unit, for example, an image sensor or a distance image sensor such as LiDAR (Light Detection and Ranging) can be used. By using the image obtained by the camera and the image obtained by the distance image sensor, more information can be acquired, enabling more accurate gesture control.

[0618] The electronic device 800A may have a vibration mechanism that functions as a bone conduction earphone. For example, a configuration having such a vibration mechanism can be applied to one or more of the display unit 820, housing 821, and mounting unit 823. This allows users to enjoy video and audio simply by wearing the electronic device 800A, without needing separate audio equipment such as headphones, earphones, or speakers.

[0619] Electronic devices 800A and 800B may each have input terminals. Cables can be connected to the input terminals to supply video signals from video output devices, etc., and power for charging batteries provided within the electronic devices.

[0620] An electronic device according to one aspect of the present invention may have a function for wireless communication with an earphone 750. The earphone 750 has a communication unit (not shown) and has a wireless communication function. The earphone 750 can receive information (e.g., voice data) from the electronic device through its wireless communication function. For example, the electronic device 700A shown in Figure 25A has a function for transmitting information to the earphone 750 through its wireless communication function. Also, for example, the electronic device 800A shown in Figure 25C has a function for transmitting information to the earphone 750 through its wireless communication function.

[0621] Furthermore, the electronic device may have an earphone section. The electronic device 700B shown in Figure 25B has an earphone section 727. For example, the earphone section 727 and the control unit can be connected to each other by a wire. Part of the wiring connecting the earphone section 727 and the control unit may be located inside the housing 721 or the mounting section 723.

[0622] Similarly, the electronic device 800B shown in Figure 25D has an earphone unit 827. For example, the earphone unit 827 and the control unit 824 can be connected to each other by a wire. Part of the wiring connecting the earphone unit 827 and the control unit 824 may be located inside the housing 821 or the mounting unit 823. Also, the earphone unit 827 and the mounting unit 823 may have magnets. This allows the earphone unit 827 to be fixed to the mounting unit 823 by magnetic force, which is preferable as it facilitates storage.

[0623] Furthermore, the electronic device may have an audio output terminal to which earphones or headphones can be connected. The electronic device may also have an audio input terminal and / or an audio input mechanism. For example, a sound-collecting device such as a microphone can be used as the audio input mechanism. By having an audio input mechanism, the electronic device may be given the function of a so-called headset.

[0624] Thus, as one embodiment of the present invention, both eyeglass-type (electronic devices 700A and 700B, etc.) and goggle-type (electronic devices 800A and 800B, etc.) are preferred as electronic devices.

[0625] Furthermore, an electronic device according to one aspect of the present invention can transmit information to earphones via wired or wireless means.

[0626] The electronic device 6500 shown in Figure 26A is a portable information terminal that can be used as a smartphone.

[0627] The electronic device 6500 includes a housing 6501, a display unit 6502, a power button 6503, a button 6504, a speaker 6505, a microphone 6506, a camera 6507, and a light source 6508, etc. The display unit 6502 has a touch panel function.

[0628] A display device according to one embodiment of the present invention can be applied to the display unit 6502. Therefore, an extremely high-resolution electronic device can be made.

[0629] Figure 26B is a schematic cross-sectional view of the housing 6501, including the end on the microphone 6506 side.

[0630] A light-transmitting protective member 6510 is provided on the display side of the housing 6501, and the display panel 6511, optical member 6512, touch sensor panel 6513, printed circuit board 6517, and battery 6518 are arranged in the space enclosed by the housing 6501 and the protective member 6510.

[0631] The protective member 6510 is fixed to the display panel 6511, the optical member 6512, and the touch sensor panel 6513 by an adhesive layer (not shown).

[0632] In the area outside the display unit 6502, a portion of the display panel 6511 is folded back, and the FPC 6515 is connected to this folded area. IC 6516 is mounted on the FPC 6515. The FPC 6515 is connected to terminals provided on the printed circuit board 6517.

[0633] A flexible display according to one embodiment of the present invention can be applied to the display panel 6511. This makes it possible to realize an extremely lightweight electronic device. Furthermore, because the display panel 6511 is extremely thin, it is possible to incorporate a large-capacity battery 6518 while keeping the thickness of the electronic device low. In addition, by folding back a part of the display panel 6511 and placing the connection part with the FPC 6515 on the back of the pixel area, an electronic device with a narrow bezel can be realized.

[0634] Figure 26C shows an example of a television system. The television system 7100 has a display unit 7000 incorporated into a housing 7101. Here, the housing 7101 is shown supported by a stand 7103.

[0635] A display device according to one embodiment of the present invention can be applied to the display unit 7000. Therefore, an extremely high-resolution electronic device can be made.

[0636] The television device 7100 shown in Figure 26C can be operated using the operation switches on the housing 7101 and a separate remote control unit 7111. Alternatively, the display unit 7000 may be equipped with a touch sensor, and the television device 7100 can be operated by touching the display unit 7000 with a finger or the like. The remote control unit 7111 may have a display unit that displays information output from the remote control unit 7111. Channels and volume can be controlled and the image displayed on the display unit 7000 can be controlled using the operation keys or touch panel on the remote control unit 7111.

[0637] The television system 7100 is configured to include a receiver and a modem. The receiver can receive general television broadcasts. Furthermore, by connecting to a wired or wireless communication network via the modem, it is possible to perform one-way (sender to receiver) or two-way (sender and receiver, or receivers, etc.) information communication.

[0638] Figure 26D shows an example of a notebook personal computer. The notebook personal computer 7200 has a casing 7211, a keyboard 7212, a pointing device 7213, and an external connection port 7214, etc. A display unit 7000 is incorporated into the casing 7211.

[0639] A display device according to one embodiment of the present invention can be applied to the display unit 7000. Therefore, an extremely high-resolution electronic device can be made.

[0640] Figures 26E and 26F show examples of digital signage.

[0641] The digital signage 7300 shown in Figure 26E includes a housing 7301, a display unit 7000, and a speaker 7303, etc. Furthermore, it may have LED lamps, operation keys (including a power switch or operation switch), connection terminals, various sensors, and a microphone, etc.

[0642] Figure 26F shows a digital signage 7400 mounted on a cylindrical column 7401. The digital signage 7400 has a display unit 7000 that is provided along the curved surface of the column 7401.

[0643] In Figures 26E and 26F, a display device according to one embodiment of the present invention can be applied to the display unit 7000. Therefore, an extremely high-resolution electronic device can be created.

[0644] The larger the display area 7000, the more information can be provided at once. Furthermore, a larger display area 7000 is more eye-catching, which can, for example, enhance the effectiveness of advertising.

[0645] Applying a touch panel to the display unit 7000 is preferable because it not only displays images or videos on the display unit 7000, but also allows users to operate it intuitively. Furthermore, when used for purposes such as providing route information or traffic information, intuitive operation can enhance usability.

[0646] Furthermore, as shown in Figures 26E and 26F, it is preferable that the digital signage 7300 or digital signage 7400 can be linked wirelessly with an information terminal 7311 or information terminal 7411 such as a smartphone owned by the user. For example, the advertising information displayed on the display unit 7000 can be displayed on the screen of the information terminal 7311 or information terminal 7411. Also, the display on the display unit 7000 can be switched by operating the information terminal 7311 or information terminal 7411.

[0647] Furthermore, the digital signage 7300 or digital signage 7400 can be used to run games using the screen of the information terminal 7311 or information terminal 7411 as the control device (controller). This allows an unspecified number of users to participate in and enjoy the game simultaneously.

[0648] The electronic equipment shown in Figures 27A to 27G includes a housing 9000, a display unit 9001, a speaker 9003, operation keys 9005 (including a power switch or operation switch), connection terminals 9006, sensors 9007 (including functions for measuring force, displacement, position, velocity, acceleration, angular velocity, rotational speed, distance, light, liquid, magnetism, temperature, chemical substances, sound, time, hardness, electric field, current, voltage, power, radiation, flow rate, humidity, gradient, vibration, odor, or infrared radiation), and a microphone 9008, etc.

[0649] The electronic devices shown in Figures 27A to 27G have various functions. For example, they may have functions to display various information (still images, videos, or text images, etc.) on a display unit, touch panel functions, functions to display a calendar, date, or time, functions to control processing by various software (programs), wireless communication functions, or functions to read and process programs or data recorded on a recording medium. However, the functions of electronic devices are not limited to these, and they may have a variety of functions. Electronic devices may have multiple display units. Furthermore, electronic devices may be equipped with a camera, etc., and have functions to capture still images or videos and save them to a recording medium (external or built into the camera), and functions to display the captured images on a display unit.

[0650] Details of the electronic equipment shown in Figures 27A to 27G will be explained below.

[0651] Figure 27A is a perspective view showing a personal digital assistant (PDA) 9101. The PDA 9101 can be used, for example, as a smartphone. The PDA 9101 may also be equipped with a speaker 9003, a connection terminal 9006, or a sensor 9007. The PDA 9101 can also display text and image information on multiple surfaces. Figure 27A shows an example where three icons 9050 are displayed. Information 9051, indicated by a dashed rectangle, can also be displayed on other surfaces of the display unit 9001. Examples of information 9051 include notifications of incoming emails, SNS messages, phone calls, etc., the subject of the email or SNS message, the sender's name, date and time, time, battery level, and signal strength. Alternatively, icons 9050 may be displayed where the information 9051 is displayed.

[0652] Figure 27B is a perspective view showing the personal digital assistant (PDA) 9102. The PDA 9102 has the function of displaying information on three or more sides of the display unit 9001. Here, an example is shown in which information 9052, information 9053, and information 9054 are displayed on different sides. For example, a user can check information 9053, which is displayed in a position that can be observed from above the PDA 9102, while the PDA 9102 is stored in the breast pocket of their clothing. The user can check the display without taking the PDA 9102 out of their pocket and decide, for example, whether or not to answer a call.

[0653] Figure 27C is a perspective view showing the tablet terminal 9103. The tablet terminal 9103 can run various applications, such as mobile phone calls, email, document viewing and creation, music playback, internet communication, and computer games. The tablet terminal 9103 has a display unit 9001, a camera 9002, a microphone 9008, and a speaker 9003 on the front of the housing 9000, an operation key 9005 as an operation button on the left side of the housing 9000, and a connection terminal 9006 on the bottom.

[0654] Figure 27D is a perspective view showing a wristwatch-type personal information terminal 9200. The personal information terminal 9200 can be used, for example, as a smartwatch (registered trademark). The display unit 9001 has a curved display surface, allowing it to display information along the curved surface. The personal information terminal 9200 can also make hands-free calls by communicating with, for example, a wireless communication headset. Furthermore, the personal information terminal 9200 can transmit data to other information terminals and be charged via a connection terminal 9006. Charging may be performed by wireless power supply.

[0655] Figures 27E to 27G are perspective views showing a foldable personal information terminal 9201. Figure 27E shows the personal information terminal 9201 in an unfolded state, Figure 27G shows it in a folded state, and Figure 27F shows a perspective view of the state in between, transitioning from one of Figures 27E or 27G to the other. The personal information terminal 9201 offers excellent portability in its folded state and excellent readability of the display due to its seamless, wide display area in its unfolded state. The display unit 9001 of the personal information terminal 9201 is supported by three housings 9000 connected by a hinge 9055. For example, the display unit 9001 can be bent with a radius of curvature of 0.1 mm to 150 mm.

[0656] This embodiment can be combined with other embodiments as appropriate. Furthermore, if multiple configuration examples are shown within a single embodiment in this specification, these configuration examples can be combined as appropriate. [Examples]

[0657] This embodiment shows an example of an insulating layer applicable to a display device according to one aspect of the present invention. It also shows the results of a peel test of the insulating layer.

[0658] For the peel test, a structure was prepared in which two types of films to be tested were sequentially deposited on a glass substrate. The dimensions of the sample, as viewed from the top, were 126 mm in length and 25 mm in width. Tape was attached to the top surface, and tensile strength was applied to the tape. The strength at which the top film peeled off from the bottom film was measured and defined as the peel force. The sample was placed on a flat table, and tensile strength was applied to the tape in ...

Claims

1. The first insulating layer, On the first insulating layer, a light-emitting element and a light-receiving element, The second insulating layer, A third insulating layer, The resin layer on the first insulating layer, It has, The light-emitting element comprises a first pixel electrode, a first organic layer, and a common electrode. The light-receiving element comprises a second pixel electrode, a second organic layer, and the common electrode. The first organic layer described above includes a light-emitting layer, The second organic layer includes a photoelectric conversion layer, The first insulating layer has a recess, The recess has a region that overlaps with the first pixel electrode, a region that overlaps with the second pixel electrode, and a region that does not overlap with the first pixel electrode and the second pixel electrode. The second insulating layer has a region in contact with the upper surface of the first organic layer, a region in contact with the side surface of the first organic layer, and a region located below the first pixel electrode. The third insulating layer has a region in contact with the upper surface of the second organic layer, a region in contact with the side surface of the second organic layer, and a region located below the second pixel electrode. The resin layer has a region located within the recess, The common electrode is provided covering the upper surface of the resin layer. Display device.

2. In claim 1, The second insulating layer has a region below the first pixel electrode that is in contact with the first insulating layer. The third insulating layer is a display device having a region that contacts the first insulating layer below the second pixel electrode.

3. In claim 1 or claim 2, The shortest distance between the end of the first pixel electrode and the end of the second pixel electrode is greater than twice the thickness of the first organic layer. Display device.

4. In claim 1 or claim 2, The recess has a downward-convex arc shape in cross-sectional view. Display device.

5. In claim 1 or claim 2, Each of the second insulating layer and the third insulating layer comprises aluminum and oxygen. Display device.

6. The first insulating layer, The second insulating layer and the third insulating layer on the first insulating layer, The light-emitting element on the second insulating layer, The photodetector on the third insulating layer, The fourth insulating layer, The fifth insulating layer, The resin layer on the first insulating layer, It has, The first insulating layer is an organic insulating layer, The second and third insulating layers are inorganic insulating layers. The light-emitting element comprises a first pixel electrode, a first organic layer, and a common electrode. The light-receiving element comprises a second pixel electrode, a second organic layer, and the common electrode. The first organic layer described above includes a light-emitting layer, The second organic layer includes a photoelectric conversion layer, The first insulating layer has a recess, The recess has a region that overlaps with the first pixel electrode, a region that overlaps with the second pixel electrode, and a region that does not overlap with the first pixel electrode and the second pixel electrode. The fourth insulating layer has a region in contact with the upper surface of the first organic layer, a region in contact with the side surface of the first organic layer, and a region in contact with the second insulating layer below the first pixel electrode. The fifth insulating layer has a region in contact with the upper surface of the second organic layer, a region in contact with the side surface of the second organic layer, and a region in contact with the third insulating layer below the second pixel electrode. The resin layer has a region located within the recess, The common electrode is provided covering the upper surface of the resin layer. Display device.

7. A first pixel electrode and a second pixel electrode are formed on the first insulating layer. A portion of the first insulating layer is etched to form a recess having a region that overlaps with the first pixel electrode, a region that overlaps with the second pixel electrode, and a region that does not overlap with the first pixel electrode and the second pixel electrode. By forming a first organic film on the first pixel electrode, the second pixel electrode, and the first insulating layer, a first organic layer is formed on the first pixel electrode, and a second organic layer is formed on the second pixel electrode. A second insulating layer is formed on the first organic layer. Remove the second organic layer, By forming a second organic film on the first organic layer, on the second pixel electrode, and on the first insulating layer, a third organic layer is formed on the second pixel electrode, and a fourth organic layer is formed on the first organic layer. A third insulating layer is formed on the third organic layer described above. Remove the fourth organic layer, A resin layer is formed on the first insulating layer, the second insulating layer, and the third insulating layer. By removing a portion of the resin layer, a portion of the second insulating layer, and a portion of the third insulating layer, a first opening reaching the first organic layer is formed in the resin layer and the second insulating layer, and a second opening reaching the third organic layer is formed in the resin layer and the third insulating layer. A method for manufacturing a display device, comprising forming a common electrode such that it is superimposed on the first organic layer through the first opening and on the third organic layer through the second opening.

8. In claim 7, The first organic film comprises a luminescent compound that emits light having intensity in the red wavelength range, the green wavelength range, or the blue wavelength range. A method for manufacturing a display device, wherein the second organic film contains a luminescent compound that emits light having intensity in a wavelength range of a different color from the first organic film, among the red wavelength range, the green wavelength range, and the blue wavelength range.

9. In claim 7, The first organic film comprises a luminescent compound, The method for manufacturing a display device, wherein the second organic film includes an organic semiconductor.

10. The first insulating layer, The first light-emitting element, the second light-emitting element, and the resin layer on the first insulating layer, The second insulating layer, A third insulating layer, It has, The first light-emitting element described above includes a first pixel electrode, a first organic layer, and a common electrode. The second light-emitting element comprises a second pixel electrode, a second organic layer, and the common electrode. The first organic layer and the second organic layer each include a light-emitting layer. The first insulating layer has a recess, The recess has a groove-shaped region that is provided along the edge of the first pixel electrode in a plan view, The groove-shaped region includes a first region overlapping with the first pixel electrode and a second region overlapping with the second pixel electrode. The width of the first region is 20 nm or more and 500 nm or less. The width of the second region is 20 nm or more and 500 nm or less. The second insulating layer has a region in contact with the upper surface of the first organic layer, a region in contact with the side surface of the first organic layer, and a region located below the first pixel electrode. The third insulating layer has a region in contact with the upper surface of the second organic layer, a region in contact with the side surface of the second organic layer, and a region located below the second pixel electrode. The resin layer has a region located within the recess, The common electrode has a region that covers the upper surface of the resin layer. Display device.

11. In claim 10, The depth of the groove-like region is between 50 nm and 3000 nm. Display device.

12. In claim 10 or claim 11, The second insulating layer has a region below the first pixel electrode that is in contact with the first insulating layer. The third insulating layer is a display device having a region that contacts the first insulating layer below the second pixel electrode.

13. In claim 10 or claim 11, The shortest distance between the end of the first pixel electrode and the end of the second pixel electrode is greater than twice the thickness of the first organic layer. Display device.

14. In claim 10 or claim 11, The recess has a downward-convex arc shape in cross-sectional view. Display device.

15. In claim 10 or claim 11, Each of the second insulating layer and the third insulating layer comprises aluminum and oxygen. Display device.

16. The first insulating layer, The second insulating layer, the third insulating layer, and the resin layer are located on the first insulating layer. The first light-emitting element on the second insulating layer, The second light-emitting element on the third insulating layer, The fourth insulating layer, The fifth insulating layer, It has, The first insulating layer is an organic insulating layer, The second and third insulating layers are inorganic insulating layers. The first light-emitting element described above includes a first pixel electrode, a first organic layer, and a common electrode. The second light-emitting element comprises a second pixel electrode, a second organic layer, and the common electrode. The first organic layer and the second organic layer each include a light-emitting layer. The first insulating layer has a recess, The recess has a groove-shaped region that is provided along the edge of the first pixel electrode in a plan view, The groove-shaped region includes a first region overlapping with the first pixel electrode and a second region overlapping with the second pixel electrode. The width of the first region is 20 nm or more and 500 nm or less. The width of the second region is 20 nm or more and 500 nm or less. The fourth insulating layer has a region in contact with the upper surface of the first organic layer, a region in contact with the side surface of the first organic layer, and a region in contact with the second insulating layer below the first pixel electrode. The fifth insulating layer has a region in contact with the upper surface of the second organic layer, a region in contact with the side surface of the second organic layer, and a region in contact with the third insulating layer below the second pixel electrode. The resin layer has a region located within the recess, The common electrode has a region that covers the upper surface of the resin layer. Display device.

17. In claim 16, The depth of the groove-like region is between 50 nm and 3000 nm. Display device.

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