Indication device

Abstract

The present invention provides a display device that has the function of detecting an object that is in contact with or close to the display unit. [Solution] A display device having a light-emitting element and a light-receiving element. The light-emitting element has a first pixel electrode, a first functional layer, a light-emitting layer, a common layer, and a common electrode, and the light-receiving element has a second pixel electrode, a second functional layer, a light-receiving layer, a common layer, and a common electrode. The first functional layer has either a hole injection layer or an electron injection layer, and the second functional layer has either a hole transport layer or an electron transport layer. In the light-emitting element, the common layer functions as the other of the hole injection layer or the electron injection layer, and in the light-receiving element, it functions as the other of the hole transport layer or the electron transport layer.

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. A semiconductor device refers to any device that can function by utilizing semiconductor properties. [Background technology]

[0003] In recent years, display devices have been used in a wide variety of equipment, including smartphones, tablet devices, laptop PCs, television equipment, and monitors. Furthermore, there is a growing demand for display devices that offer more than just image display capabilities, such as touch sensor functionality or fingerprint scanning for authentication.

[0004] As a display device, for example, light-emitting devices having light-emitting elements (also called light-emitting devices) have been developed. In particular, light-emitting elements (also called EL elements or EL devices) that utilize the electroluminescence (EL) phenomenon have features such as being easy to make thin and light, being able to respond quickly to input signals, and being able to be driven using a DC constant voltage power supply, and are being applied to display devices. For example, Patent Document 1 discloses a flexible light-emitting device to which an organic EL element (also called an organic EL device) is applied. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2014-197522 [Overview of the Initiative]

Problems to be Solved by the Invention

[0006] One aspect of the present invention is to provide a display device having a function of detecting an object in contact with or close to a display unit, and a method for manufacturing the same. One aspect of the present invention is to provide a display device having a function of performing authentication, and a method for manufacturing the same. One aspect of the present invention is to provide a display device having a high aperture ratio, and a method for manufacturing the same. One aspect of the present invention is to provide a small-sized display device, and a method for manufacturing the same. One aspect of the present invention is to provide a highly reliable display device, and a method for manufacturing the same. One aspect of the present invention is to provide a novel display device, and a method for manufacturing the same.

[0007] Note that the description of these problems does not prevent the existence of other problems. Note that one aspect of the present invention does not need to solve all of these problems. Note that other problems can be extracted from the descriptions in the specification, drawings, claims, etc.

Means for Solving the Problems

[0008] One aspect of the present invention has a light-emitting element and a light-receiving element. The light-emitting element has a first pixel electrode, a first functional layer, a light-emitting layer, a common layer, and a common electrode. The light-receiving element has a second pixel electrode, a second functional layer, a light-receiving layer, a common layer, and a common electrode. The first functional layer has either a hole injection layer or an electron injection layer. The second functional layer has either a hole transport layer or an electron transport layer. The common layer functions as the other of the hole injection layer or the electron injection layer in the light-emitting element, and is a display device.

[0009] Alternatively, in the above aspect, the first functional layer and the second functional layer may be separated from each other.

[0010] Alternatively, in the above aspect, it has a first transistor and a second transistor. One of the source or drain of the first transistor is electrically connected to the first pixel electrode, and one of the source or drain of the second transistor is electrically connected to the second pixel electrode. The first transistor and the second transistor may have silicon or a metal oxide in the channel formation region.

[0011] Alternatively, one aspect of the present invention includes: a first step of forming a first pixel electrode, a second pixel electrode, and a connection electrode; a second step of forming a light-emitting film on the first pixel electrode and the second pixel electrode; a third step of forming a first sacrificial film on the light-emitting film and the connection electrode; a fourth step of etching the first sacrificial film and the light-emitting film to expose the second pixel electrode, and forming a light-emitting layer on the first pixel electrode, a first sacrificial layer on the light-emitting layer and the connection electrode; a fifth step of forming a light-receiving film on the light-emitting layer and the second pixel electrode; a sixth step of forming a second sacrificial film on the light-receiving film and the connection electrode; a seventh step of etching the second sacrificial film and the light-receiving film to form a light-receiving layer on the second pixel electrode, and a second sacrificial layer on the light-receiving layer and the connection electrode; an eighth step of removing the first sacrificial layer and the second sacrificial layer; a ninth step of forming a common layer on the light-emitting layer and the light-receiving layer; and a tenth step of forming a common electrode so as to have a region in contact with the common layer and the connection electrode. It is a method for manufacturing a display device.

[0012] Alternatively, in the above aspect, in a light-emitting element having a first pixel electrode, a light-emitting layer, a common layer, and a common electrode, the common layer may function as one of a hole injection layer or an electron injection layer.

[0013] Alternatively, in the above embodiment, between the first and second steps, there is an eleventh step of forming a first functional film on the first and second pixel electrodes, in the fourth step, etching the first functional film to form a first functional layer on the first pixel electrode, in the twelfth step between the fourth and fifth steps, forming a second functional film on the first sacrificial layer and the second pixel electrode, in the seventh step, etching the second functional film to form a second functional layer on the second pixel electrode, the first functional layer may have a hole injection layer or an electron injection layer, and the second functional layer may have a hole transport layer or an electron transport layer.

[0014] Alternatively, in the above embodiment, the light-emitting film, the light-receiving film, and the common layer may be formed by a vapor deposition method using a shielding mask.

[0015] Alternatively, in the above embodiment, the first sacrificial film and the second sacrificial film include the same metal film, alloy film, metal oxide film, semiconductor film, or inorganic insulating film, and in the fourth step, the light-emitting film is etched by dry etching using an etching gas that does not contain oxygen as a main component, and in the eighth step, the first sacrificial layer and the second sacrificial layer may be removed by wet etching using an aqueous solution of tetramethylammonium hydroxide, dilute hydrofluoric acid, oxalic acid, phosphoric acid, acetic acid, nitric acid, or a mixture thereof.

[0016] Alternatively, in the above embodiment, the first sacrificial film and the second sacrificial film may contain aluminum oxide.

[0017] Alternatively, in the above embodiment, there may be a 14th step of forming a protective layer on the common electrode after the 10th step. [Effects of the Invention]

[0018] According to one aspect of the present invention, a display device having a function to detect an object in contact with or near a display unit, and a method for manufacturing the same, can be provided. According to one aspect of the present invention, a display device having an authentication function, and a method for manufacturing the same, can be provided. According to one aspect of the present invention, a display device with a high aperture ratio, and a method for manufacturing the same, can be provided. According to one aspect of the present invention, a compact display device, and a method for manufacturing the same, can be provided. According to one aspect of the present invention, a highly reliable display device, and a method for manufacturing the same, can be provided. According to one aspect of the present invention, a novel display device, and a method for manufacturing the same, can be provided.

[0019] 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]

[0020] [Figure 1] Figures 1A to 1E are cross-sectional views showing examples of the configuration of a display device. Figure 1F is a diagram showing an example of an captured image. [Figure 2] Figures 2A and 2B are top views showing examples of the configuration of a display device. [Figure 3] Figures 3A and 3B are top views showing examples of the configuration of a display device. [Figure 4] Figure 4A is a top view showing an example of the configuration of a display device. Figure 4B is a diagram showing the light-receiving range of the light-receiving element. [Figure 5] Figure 5 is a top view showing an example of the configuration of a display device. [Figure 6] Figures 6A to 6E are cross-sectional views showing examples of the configuration of a display device. [Figure 7] Figures 7A to 7D are cross-sectional views showing examples of methods for manufacturing a display device. [Figure 8] Figures 8A to 8C are cross-sectional views showing examples of methods for manufacturing a display device. [Figure 9]Figures 9A to 9D are cross-sectional views showing examples of methods for manufacturing a display device. [Figure 10] Figures 10A to 10C are cross-sectional views showing examples of methods for manufacturing a display device. [Figure 11] Figures 11A to 11C are cross-sectional views showing examples of methods for manufacturing a display device. [Figure 12] Figure 12A is a top view showing an example of the configuration of a display device. Figures 12B and 12C are cross-sectional views showing an example of the configuration of a display device. [Figure 13] Figure 13A is a top view showing an example of the configuration of a display device. Figure 13B is a cross-sectional view showing an example of the configuration of a display device. [Figure 14] Figure 14 is a perspective view showing an example of a display device configuration. [Figure 15] Figure 15 is a cross-sectional view showing an example of the configuration of a display device. [Figure 16] Figure 16 is a cross-sectional view showing an example of the configuration of a display device. [Figure 17] Figure 17 is a cross-sectional view showing an example of the configuration of a display device. [Figure 18] Figure 18 is a cross-sectional view showing an example of the configuration of a display device. [Figure 19] Figure 19 is a cross-sectional view showing an example of the configuration of a display device. [Figure 20] Figures 20A to 20D are cross-sectional views showing examples of the configuration of a light-emitting element. [Figure 21] Figures 21A and 21B show examples of display device configurations. [Figure 22] Figures 22A to 22G show examples of display device configurations. [Figure 23] Figures 23A to 23E show examples of electronic devices. [Modes for carrying out the invention]

[0021] 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.

[0022] 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.

[0023] 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.

[0024] Furthermore, the ordinal numbers "1st," "2nd," etc., used in this specification are added to avoid confusion of constituent elements and do not imply any numerical limitation.

[0025] Furthermore, in this specification, the terms "film" and "layer" are interchangeable. For example, the terms "conductive layer" or "insulating layer" may be interchangeable with the terms "conductive film" or "insulating film."

[0026] In this specification, the term "EL layer" refers to a layer (also called a light-emitting layer) provided between a pair of electrodes of a light-emitting element and containing at least a light-emitting substance, or a laminate including a light-emitting layer.

[0027] In this specification, a display panel, which is one form of a display device, has the function of displaying (outputting), for example, an image on its display surface. Therefore, a display panel is one form of an output device.

[0028] Furthermore, in this specification, a display panel on which a connector such as an FPC (Flexible Printed Circuit) or TCP (Tape Carrier Package) is attached, or on which an IC is mounted on the board using a COG (Chip On Glass) method, may be referred to as a display panel module, a display module, or simply a display panel, etc.

[0029] (Embodiment 1) This embodiment describes an example of the configuration of a display device according to one aspect of the present invention, and an example of a method for manufacturing the display device.

[0030] A display device according to one aspect of the present invention has a display unit in which pixels are arranged in a matrix. Each pixel has a plurality of subpixels, and one light-emitting element (also called a light-emitting device) is provided for each subpixel. Multiple subpixels provided in the same pixel may have the function of emitting light of different colors from each other.

[0031] Each light-emitting element has a pair of electrodes and a light-emitting layer between them. Preferably, the light-emitting elements are organic electroluminescent (OLED) elements. Two or more light-emitting elements that emit different colors each have a light-emitting layer containing a different material. For example, a full-color display device can be realized by having three types of light-emitting elements that emit red (R), green (G), or blue (B) light, respectively.

[0032] Here, when differentiating the light-emitting layers between light-emitting elements of different colors, it is known that they are formed by a deposition method using a shadow mask such as a metal mask. However, with this method, deviations from the design occur in the shape and position of the island-like organic film due to various influences such as the precision of the metal mask, the misalignment between the metal mask and the substrate, the deflection of the metal mask, and the spreading of the contour of the deposited film due to vapor scattering, making it difficult to achieve high resolution and high aperture ratio. For this reason, measures have been taken to artificially increase the resolution (also called pixel density) by applying special pixel arrangement methods such as pentile arrangements.

[0033] One aspect of the present invention involves processing the light-emitting layer into a fine pattern without using a shadow mask such as a metal mask. This allows for miniaturization of subpixels and an increase in the aperture ratio of pixels compared to when differentiating the light-emitting layer using a shadow mask. Furthermore, because differentiating the light-emitting layer is possible, a display device with extremely vivid colors, high contrast, and high display quality can be realized.

[0034] By miniaturizing subpixels, subpixels that do not contribute to display can be provided on pixels. For example, in addition to subpixels having light-emitting elements, subpixels having light-receiving elements (also called light-receiving devices) can be provided on pixels. Even in this case, the display device according to one aspect of the present invention can suppress the pixel density from becoming a small value. For example, the pixel density can be set to 400 ppi or more, 1000 ppi or more, 3000 ppi or more, or 5000 ppi or more.

[0035] A light-receiving element in a display device according to one aspect of the present invention functions as a light sensor. Therefore, a display device according to one aspect of the present invention can display an image using a light-emitting element and detect, for example, an object that is in contact with or close to the display unit using the light-receiving element. Furthermore, a display device according to one aspect of the present invention can perform authentication based on the fingerprint of a user's finger if that finger is in contact with the display unit.

[0036] By incorporating the light-receiving element into the display unit, it becomes unnecessary to attach an external sensor to the display device. Therefore, the number of components in the display device can be reduced, resulting in a smaller and lighter display device.

[0037] Furthermore, in one embodiment of the present invention, a light-emitting element emits light that is irradiated onto an object, and a light-receiving element can detect the light reflected by the object. Therefore, for example, even in a dark place, it is possible to detect an object that is in contact with or close to the display unit, and authentication such as fingerprint authentication can be performed.

[0038] 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 FMM may be referred to as MML (Metal Maskless) structured devices.

[0039] In this specification, a structure in which different light-emitting layers are created or painted for each color of light-emitting element (here, blue (B), green (G), and red (R)) may be referred to as an SBS (Side By Side) structure. Also, in this specification, a light-emitting element capable of emitting white light may be referred to as a white light-emitting element. A white light-emitting element can be combined with a colored layer (for example, a color filter) to create a light-emitting element capable of full-color display.

[0040] Furthermore, light-emitting devices can be broadly classified into single structures and tandem structures. A single-structure device has one light-emitting unit between a pair of electrodes, and it is preferable that this light-emitting unit includes one or more light-emitting layers. To obtain white light emission, one should select light-emitting layers such that the light emitted from each of the two or more layers 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, a configuration in which the entire light-emitting device emits white light can be obtained. The same applies to light-emitting devices having three or more light-emitting layers.

[0041] 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 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.

[0042] Furthermore, when comparing the aforementioned white light-emitting elements (single or tandem structure) with SBS structure light-emitting elements, SBS structure light-emitting elements can consume less power than white light-emitting elements. Therefore, if you want to keep the power consumption of the display device low, it is preferable to use SBS structure light-emitting elements. On the other hand, since the manufacturing process for white light-emitting elements is simpler than that of SBS structure light-emitting elements, manufacturing costs can be lowered or the manufacturing yield can be increased.

[0043] Figures 1A to 1E are cross-sectional views showing an example of the configuration of a display device according to one embodiment of the present invention.

[0044] The display device 10A shown in Figure 1A has a layer 53 having a light-receiving element and a layer 57 having an light-emitting element between a substrate 51 and a substrate 59.

[0045] The display device 10B shown in Figure 1B has a layer 55 having transistors, a layer 53 having light-receiving elements, and a layer 57 having light-emitting elements between substrate 51 and substrate 59.

[0046] Display devices 10A and 10B are configured to emit red (R), green (G), and blue (B) light from a layer 57 having an light-emitting element.

[0047] A display device according to one aspect of the present invention is provided on a display unit with a plurality of pixels arranged in a matrix. One pixel has one or more subpixels. One subpixel has one light-emitting element or one light-receiving element. For example, a pixel can be configured to have four subpixels. Specifically, for example, one pixel can be configured to have three light-emitting elements of R, G, and B colors and a light-receiving element, or one can be configured to have three light-emitting elements of yellow (Y), cyan (C), and magenta (M), and a light-receiving element. Furthermore, a pixel can be configured to have five subpixels. Specifically, for example, one pixel can be configured to have four light-emitting elements of R, G, B, and white (W), and a light-receiving element, or one can be configured to have four light-emitting elements of R, G, B, and infrared (IR), and a light-receiving element. Note that light-receiving elements may be provided on all pixels or on some pixels. Also, one pixel may have multiple light-receiving elements.

[0048] A display device according to one aspect of the present invention may have a function to detect an object, such as a finger, that is in contact with the display device. For example, as shown in Figures 1C and 1D, when a finger 52 in contact with the display device 10B reflects light emitted by a light-emitting element in a layer 57 having a light-emitting element, a light-receiving element in a layer 53 having a light-receiving element detects the reflected light. In the case shown in Figure 1C, it is possible to detect that a finger 52 has come into contact with the display device 10B. In the case shown in Figure 1D, it is possible to detect that a finger 52 has come close to the display device 10B. In other words, a display device according to one aspect of the present invention can function as a touch sensor (also called a direct touch sensor) and can also function as a near-touch sensor (also called a hover sensor, hover-touch sensor, non-contact sensor, or touchless sensor).

[0049] As described above, if the display device 10B functions as a near-touch sensor, the finger 52 can be detected by approaching the display device 10B even without direct contact. For example, it is preferable that the display device 10B can detect the finger 52 when the distance between the display device 10B and the finger 52 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 10B without the finger 52 directly touching it, in other words, it becomes possible to operate the display device 10B without contact (touchless). With the above configuration, the risk of the display device 10B becoming dirty or scratched can be reduced. Furthermore, it becomes possible to operate the display device 10B with the finger 52 while preventing dirt (e.g., dust or viruses, etc.) that may adhere to the display device 10B from directly touching the finger 52.

[0050] Furthermore, a display device according to one aspect of the present invention can have a function to detect, for example, the fingerprint of a finger 52. Figure 1E schematically shows an enlarged view of the contact area when a finger 52 is in contact with the substrate 59. Figure 1E also shows how a layer 57 having a light-emitting element and a layer 53 having a light-receiving element are arranged alternately.

[0051] Fingerprints are formed on finger 52 by recesses and protrusions. Therefore, as shown in Figure 1E, the protrusions of the fingerprint are in contact with the substrate 59.

[0052] 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 52 is predominantly diffuse. On the other hand, the light reflected from the interface between substrate 59 and the atmosphere is predominantly specular.

[0053] The intensity of light reflected from the contact or non-contact surface between the finger 52 and the substrate 59, and incident on the layer 53 located directly beneath them, is the sum of specular reflection and diffuse reflection. As described above, in the recessed areas of the finger 52, the substrate 59 and the finger 52 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 52 (indicated by the dashed arrow) is dominant. Therefore, the intensity of light received by the photodetector in the layer 53 located directly beneath the recessed areas is higher than the intensity of light received by the photodetector in the layer 53 located directly beneath the convex areas. Thus, the fingerprint of the finger 52 can be imaged using the photodetector.

[0054] The spacing of the light-receiving elements in layer 53 is set to be smaller than the distance between two protrusions of a fingerprint, preferably the distance between an adjacent recess and a protrusion, thereby enabling the acquisition of a clear fingerprint image. Since the distance between recesses and protrusions in a human fingerprint is generally between 150 μm and 250 μm, for example, the spacing of the light-receiving elements should be 400 μm or less, preferably 200 μm or less, more preferably 150 μm or less, even more preferably 120 μm or less, even more preferably 100 μm or less, and even more preferably 50 μm or less. A smaller spacing is preferable, but it can be, for example, 1 μm or more, 10 μm or more, or 20 μm or more.

[0055] Figure 1F shows an example of a fingerprint image captured by a display device according to one embodiment of the present invention. In Figure 1F, the contour of the finger 52 is shown by a dashed line and the contour of the contact area 69 is shown by a dashed line in region 65. In region 65, a fingerprint 67 with high contrast can be captured by varying the amount of light incident on the light-receiving element.

[0056] As described above, in one aspect of the present invention, the display device emits light from a light-emitting element, which is irradiated onto an object such as a finger 52, and the light-receiving element can detect the light reflected by the object. Therefore, even in a dark place, for example, an object that is in contact with or close to the display unit can be detected, and authentication such as fingerprint authentication can be performed.

[0057] Furthermore, by incorporating the light-receiving element into the display unit, it becomes unnecessary to attach a sensor externally to the display device. Therefore, the number of components in the display device can be reduced, making the display device smaller and lighter.

[0058] [Configuration Example 1] Figure 2A is a schematic top view showing an example configuration of a display device 10 according to one embodiment of the present invention. The display device 10 has multiple light-emitting elements 110R that emit red light, multiple light-emitting elements 110G that emit green light, multiple light-emitting elements 110B that emit blue light, and multiple light-receiving elements 150. In Figure 2A, the labels R, G, and B are added to the light-emitting area of ​​each light-emitting element 110 to simplify the distinction between them. The label PD is also added to the light-receiving area of ​​each light-receiving element 150.

[0059] In this specification, when describing matters common to, for example, display device 10A and display device 10B, or when there is no need to distinguish between them, the term "display device 10" is used. In other words, the configuration of display device 10 can be applied to both display device 10A shown in Figure 1A and display device 10B shown in Figure 1B. The same applies to other elements.

[0060] The light-emitting elements 110R, 110G, 110B, and light-receiving elements 150 are each arranged in a matrix. Figure 2A shows an example in which the light-emitting elements 110R, 110G, and 110B are arranged in the X direction, with the light-receiving elements 150 arranged below them. Figure 2A also shows an example configuration in which light-emitting elements 110 emitting light of the same color are arranged in the Y direction intersecting the X direction. In the display device 10 shown in Figure 2A, for example, a pixel 20 can be composed of sub-pixels having light-emitting elements 110R, sub-pixels having light-emitting elements 110G, and sub-pixels having light-emitting elements 110B arranged in the X direction, and sub-pixels having light-receiving elements 150 provided below these sub-pixels.

[0061] It is preferable to use EL elements such as OLED (Organic Light Emitting Diode) or QLED (Quantum-dot Light Emitting Diode) as the light-emitting elements 110R, 110G, and 110B. Examples of light-emitting materials for EL elements include fluorescent materials, phosphorescent materials, inorganic compounds (e.g., quantum dot materials), or thermally activated delayed fluorescence (Thermally activated delayed fluorescence (TADF) materials).

[0062] For example, a pn-type or pin-type photodiode can be used as the light-receiving element 150. The light-receiving element 150 functions as a photoelectric conversion device that detects light incident on it and generates an electric charge. The amount of charge generated is determined based on the amount of incident light.

[0063] In particular, it is preferable to use an organic photodiode having a layer containing an organic compound as the light-receiving element 150. 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 various display devices.

[0064] In one aspect of the present invention, an organic EL device is used as the light-emitting element 110, and an organic photodiode is used as the light-receiving element 150. The organic EL device 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 device.

[0065] Figure 2A shows a common electrode 123 and a connecting electrode 111C. Here, the connecting electrode 111C is electrically connected to the common electrode 123. The connecting electrode 111C is located outside the display section where the light-emitting element 110 and the light-receiving element 150 are arranged. Also in Figure 2A, the common electrode 123, which has an overlapping region with the light-emitting element 110, the light-receiving element 150, and the connecting electrode 111C, is shown with a dashed line.

[0066] The connecting electrode 111C can be provided along the outer circumference of the display unit. For example, it may be provided along one side of the outer circumference of the display unit, or it may be provided across two or more sides of the outer circumference of the display unit. That is, if the top surface shape of the display unit is rectangular, the top surface shape of the connecting electrode 111C can be strip-shaped, L-shaped, U-shaped (angle bracket-shaped), or frame-shaped, etc.

[0067] Figure 2B is a schematic top view showing an example configuration of the display device 10, and is a modified version of the display device 10 shown in Figure 2A. The display device 10 shown in Figure 2B differs from the display device 10 shown in Figure 2A in that it has a light-emitting element 110IR that emits infrared light. The light-emitting element 110IR can emit, for example, near-infrared light (light with a wavelength of 750 nm to 1300 nm).

[0068] In the example shown in Figure 2B, light-emitting elements 110R, 110G, and 110B, as well as light-emitting element 110IR, are arranged in the X direction, with a photodetector 150 arranged below them. The photodetector 150 also has the function of detecting infrared light.

[0069] Figure 3A is a schematic top view showing an example configuration of the display device 10, and is a modified version of the display device 10 shown in Figure 2B. The display device 10 shown in Figure 3A differs from the display device 10 shown in Figure 2B in that the light-receiving element 150 and the light-emitting element 110IR are arranged alternately in the X direction.

[0070] In the display device 10 shown in Figure 3A, the light-emitting elements 110R, 110G, and 110B are arranged in different rows from the light-emitting element 110IR. Therefore, the width (length in the X direction) of the light-emitting elements 110R, 110G, and 110B can be increased, thereby increasing the brightness of the light emitted by the pixels 20.

[0071] Figure 3B is a schematic top view showing an example configuration of the display device 10, and is a modified version of the display device 10 shown in Figure 3A. The display device 10 shown in Figure 3A differs from the display device 10 shown in Figure 3A in that the light-emitting elements 110 are arranged in the order G, B, R in the X direction, rather than in the order R, G, B. Also, the light-receiving element 150 is provided below the light-emitting elements 110G and 110B, and the light-emitting element 110IR is provided below the light-emitting element 110R, which is another difference from the display device 10 shown in Figure 3A.

[0072] The area occupied by the light-receiving element 150 in the display device 10 shown in Figure 3B is larger than the area occupied by the light-receiving element 150 in the display device 10 shown in Figure 3A. Therefore, the light detection sensitivity of the light-receiving element 150 can be increased. Consequently, for example, if the display device 10 functions as a touch sensor or a near-touch sensor, objects that are in contact with or close to the display device 10 can be detected with high accuracy. In particular, if the display device 10 functions as a near-touch sensor, the light detection sensitivity of the light-receiving element 150 greatly affects the accuracy of object detection, so it is preferable to increase the area occupied by the light-receiving element 150.

[0073] Figure 4A is a schematic top view showing an example configuration of the display device 10, and is a modified version of the display device 10 shown in Figure 3B. The display device 10 shown in Figure 4A differs from the display device 10 shown in Figure 3B in that the light-receiving element 150 is located below the light-emitting element 110G, and the light-emitting element 110IR is located below the light-emitting elements 110B and 110R.

[0074] The area occupied by the light-receiving element 150 in the display device 10 shown in Figure 4A is smaller than the area occupied by the light-receiving element 150 in the display device 10 shown in Figure 3B. By reducing the area occupied by the light-receiving element 150, the light-receiving range of each individual light-receiving element 150 can be reduced. This reduces the overlap of light-receiving ranges between different light-receiving elements 150, for example, between adjacent light-receiving elements 150. Therefore, blurring of images captured using the light-receiving element 150, which can result in unclear imaging, can be suppressed. For example, if the display device 10 has a function for authentication such as fingerprint authentication, reducing the area occupied by the light-receiving element 150 is preferable because it allows for clearer imaging of fingerprints, for example, and improves the accuracy of authentication.

[0075] Figure 4B is a cross-sectional view showing the change in the light-receiving range of the light-receiving element 150 when the occupied area of ​​the light-receiving element 150, specifically its length in the X direction, is changed. In Figure 4B, the light-receiving element 150 is shown on the lower side of layer 71, and the light-shielding layer 73 is shown on the upper side of layer 71. A substrate 59 is also shown on layer 71. Furthermore, a light-receiving element with a length in the X direction approximately three times that of the light-receiving element 150 is referred to as light-receiving element 150L.

[0076] In Figure 4B, the light incident on the photodetector 150 is denoted as light 75 and shown by a solid line. Light that is not incident on the photodetector 150 but is incident on the photodetector 150L is denoted as light 77 and shown by a dashed line. The light-receiving range of each photodetector 150 is defined as the light-receiving range 80, and the light-receiving range of each photodetector 150L is defined as the light-receiving range 81.

[0077] As shown in Figure 4B, the light-receiving range 80 of the photodetector 150 is narrower than the light-receiving range 81 of the photodetector 150L. In other words, as the occupied area of ​​the photodetector decreases, the light-receiving range per photodetector becomes narrower, and the overlap of light-receiving ranges between different photodetectors decreases. Figure 4B shows an example on the surface of the substrate 59 where the light-receiving ranges 80 do not overlap between adjacent photodetectors 150, but a portion of the light-receiving ranges 81 overlap between adjacent photodetectors 150L.

[0078] Figure 5 is a schematic top view showing an example configuration of the display device 10, and is a modified version of the display device 10 shown in Figure 2A. The display device 10 shown in Figure 5 differs from the display device 10 shown in Figure 2A in that light-receiving elements 150 are provided only on some of the pixels 20. In Figure 5, pixels 20 that do not have light-receiving elements 150 are referred to as pixels 20a.

[0079] By configuring the display device 10 as shown in Figure 5, the driving frequency of the display device 10 can be increased. Therefore, for example, if the display device 10 functions as a touch sensor or a near-touch sensor, the position of an object that is in contact with or close to the display device 10 can be detected quickly. Therefore, for example, the movement of an object that is in contact with or close to the display device 10 can be detected at high speed and with high accuracy.

[0080] Figure 6A is a cross-sectional view corresponding to the dashed line A1-A2 in Figure 2A, and Figure 6B is a cross-sectional view corresponding to the dashed line B1-B2 in Figure 2A. Furthermore, Figure 6C is a cross-sectional view corresponding to the dashed line C1-C2 in Figure 2A, and Figure 6D is a cross-sectional view corresponding to the dashed line D1-D2 in Figure 2A. In addition, Figure 6E is a cross-sectional view corresponding to the dashed line B3-B4 in Figure 3A. The light-emitting element 110R, light-emitting element 110G, light-emitting element 110B, and light-receiving element 150 are provided on the substrate 101. Furthermore, if the display device 10 has a light-emitting element 110IR, the light-emitting element 110IR is provided on the substrate 101.

[0081] In this specification, for example, when we refer to "B on A" or "B below A," it is not necessarily required that A and B have areas in contact.

[0082] Figure 6A shows an example of the cross-sectional configuration of the light-emitting element 110R, light-emitting element 110G, and light-emitting element 110B. Figure 6B also shows an example of the cross-sectional configuration of the light-receiving element 150.

[0083] The light-emitting element 110R has a pixel electrode 111R, a hole injection layer 113R, a hole transport layer 115R, a light-emitting layer 117R, an electron transport layer 119R, a common layer 121, and a common electrode 123. The light-emitting element 110G has a pixel electrode 111G, a hole injection layer 113G, a hole transport layer 115G, a light-emitting layer 117G, an electron transport layer 119G, a common layer 121, and a common electrode 123. The light-emitting element 110B has a pixel electrode 111B, a hole injection layer 113B, a hole transport layer 115B, a light-emitting layer 117B, an electron transport layer 119B, a common layer 121, and a common electrode 123. The light-receiving element 150 has a pixel electrode 111PD, a hole transport layer 115PD, a light-receiving layer 157, an electron transport layer 119PD, a common layer 121, and a common electrode 123.

[0084] In the light-emitting element 110, the common layer 121 functions as an electron injection layer. On the other hand, in the photodetector 150, the common layer 121 functions as an electron transport layer. Therefore, the photodetector 150 does not need to have an electron transport layer 119PD.

[0085] The hole injection layer 113, the hole transport layer 115, the electron transport layer 119, and the common layer 121 can also be called functional layers.

[0086] The pixel electrode 111, hole injection layer 113, hole transport layer 115, light-emitting layer 117, and electron transport layer 119 can be provided separately for each element. The common layer 121 and common electrode 123 are provided in common for the light-emitting element 110R, light-emitting element 110G, light-emitting element 110B, and light-receiving element 150.

[0087] Furthermore, the light-emitting element 110 and the light-receiving element 150 may have a hole-blocking layer and an electron-blocking layer in addition to the layers shown in Figures 6A and 6B. Also, the light-emitting element 110 and the light-receiving element 150 may have layers containing bipolar materials (materials with high electron-transport and hole-transport properties).

[0088] A gap is provided between the common layer 121 and the insulating layer 131. This prevents the common layer 121 from coming into contact with the sides of the light-emitting layer 117, the light-receiving layer 157, the hole transport layer 115, and the hole injection layer 113. This prevents short circuits in the light-emitting element 110 and the light-receiving element 150.

[0089] The above-mentioned voids are more likely to form when the distance between the light-emitting layers 117 is shorter, for example. For example, if the distance is 1 μm or less, preferably 500 nm or less, and more preferably 200 nm or less, 100 nm or less, 90 nm or less, 70 nm or less, 50 nm or less, 30 nm or less, 20 nm or less, 15 nm or less, or 10 nm or less, the above-mentioned voids can be suitably formed.

[0090] Figure 6A shows a configuration in which the light-emitting element 110 is provided with, in order from the bottom layer, a pixel electrode 111, a hole injection layer 113, a hole transport layer 115, a light-emitting layer 117, an electron transport layer 119, a common layer 121 (electron injection layer), and a common electrode 123, and the light-receiving element 150 is provided with, in order from the bottom layer, a pixel electrode 111PD, a hole transport layer 115PD, a light-receiving layer 157, an electron transport layer 119PD, a common layer 121, and a common electrode 123. However, the present invention is not limited to this configuration. For example, the light-emitting element 110 may be provided with, in order from the bottom layer, a pixel electrode, an electron injection layer, an electron transport layer, a light-emitting layer, a hole transport layer, a hole injection layer, and a common electrode, and the light-receiving element 150 may be provided with, in order from the bottom layer, a pixel electrode, an electron transport layer, a light-receiving layer, a hole transport layer, and a common electrode. In this case, the hole injection layer of the light-emitting element 110 can be a common layer, and this common layer can be provided between the hole transport layer of the photodetector 150 and the common electrode. Furthermore, in the light-emitting element 110, the electron injection layer can be separated for each element.

[0091] In the following explanation, we will assume that the electron transport layer is located above the hole transport layer. However, by, for example, substituting "electron" with "hole" and vice versa, the following explanation can also be applied when the electron transport layer is located below the hole transport layer.

[0092] 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).

[0093] 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. 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, or furan derivatives) or aromatic amines (compounds having an aromatic amine skeleton) that have high hole transport capabilities.

[0094] 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 2 Materials 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, or 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, or other π-electron-deficient heteroaromatic compounds containing nitrogen-containing heteroaromatic compounds, which are materials with high electron transport capabilities.

[0095] 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.

[0096] Examples of electron injection layers include lithium, cesium, lithium fluoride (LiF), cesium fluoride (CsF), calcium fluoride (CaF2), 8-(quinolinolato)lithium (abbreviated as Liq), 2-(2-pyridyl)phenolate (abbreviated as LiPP), 2-(2-pyridyl)-3-pyridinolatritium (abbreviated as LiPPy), 4-phenyl-2-(2-pyridyl)phenolate (abbreviated as LiPPP), and lithium oxide (LiO2). x ), alkali metals such as cesium carbonate, alkaline earth metals, or compounds thereof can be used.

[0097] Alternatively, an electron-transporting material may be used as the electron injection layer described above. 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.

[0098] Furthermore, it is preferable that the lowest unoccupied molecular orbital (LUMO) of an organic compound containing a lone pair of electrons is between -3.6 eV and -2.3 eV. In general, the highest occupied molecular orbital (HOMO) level and LUMO level of an organic compound can be estimated by methods such as cyclic voltammetry (CV), photoelectron spectroscopy, optical absorption spectroscopy, and inverse photoelectron spectroscopy.

[0099] For example, 4,7-diphenyl-1,10-phenanthroline (abbreviated as BPhen), 2,9-bis(naphthalene-2-yl)-4,7-diphenyl-1,10-phenanthroline (abbreviated as NBPhen), diquinoxalino[2,3-a:2',3'-c]phenazine (abbreviated as HATNA), or 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. Compared to BPhen, NBPhen has a higher glass transition temperature (Tg) and superior heat resistance.

[0100] The luminescent layer is a layer containing a luminescent material. The luminescent layer may contain one or more types of luminescent materials. The luminescent material may be any material that emits light of a specific color, such as blue, purple, blue-violet, green, yellow-green, yellow, orange, or red. A material that emits near-infrared light may also be used as the luminescent material.

[0101] Examples of luminescent materials include fluorescent materials, phosphorescent materials, TADF materials, or quantum dot materials.

[0102] 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, or naphthalene derivatives.

[0103] 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.

[0104] 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 of these organic compounds may be hole-transporting materials and / or electron-transporting materials. Alternatively, one or more of these organic compounds may be bipolar materials or TADF materials.

[0105] 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. This configuration allows for efficient emission using ExTET (Exciplex-Triplet Energy Transfer), which is energy transfer from the excitation complex to the light-emitting substance (phosphorescent material). By selecting a combination that forms an excitation complex that emits light overlapping with the wavelength of the lowest-energy absorption band of the light-emitting substance, energy transfer becomes smoother, and light emission can be obtained efficiently. This configuration simultaneously achieves high efficiency, low-voltage operation, and a long lifespan for the light-emitting element.

[0106] The light-emitting layer 117R of the light-emitting element 110R has a luminescent organic compound that emits light having intensity in at least the red wavelength range. The light-emitting layer 117G of the light-emitting element 110G has a luminescent organic compound that emits light having intensity in at least the green wavelength range. The light-emitting layer 117B of the light-emitting element 110B has a luminescent organic compound that emits light having intensity in at least the blue wavelength range. The light-receiving layer 157 of the light-receiving element 150 has an organic compound that has detection sensitivity in, for example, the visible light wavelength range.

[0107] A conductive film that is transparent to visible light is used on either the pixel electrode 111 or the common electrode 123, and a conductive film that is reflective is used on the other. By making the pixel electrode 111 transparent and the common electrode 123 reflective, the display device 10 can be made into a bottom-emission type display device. On the other hand, by making the pixel electrode 111 reflective and the common electrode 123 transparent, the display device 10 can be made into a top-emission type display device. Furthermore, by making both the pixel electrode 111 and the common electrode 123 transparent, the display device 10 can be made into a dual-emission type display device.

[0108] Furthermore, it is preferable that the light-emitting element 110 has a microcavity structure. This allows the light emitted from the light-emitting layer 117 to resonate between the pixel electrode 111 and the common electrode 123, thereby intensifying the light emitted from the light-emitting element 110.

[0109] When the light-emitting element 110 has a microcavity structure, it is preferable that one of the common electrode 123 or the pixel electrode 111 is an electrode that has both light transmission and reflectivity (a semi-transparent / semi-reflective electrode), and the other of the common electrode 123 or the pixel electrode 111 is a reflective electrode (a reflective electrode). Here, the semi-transparent / semi-reflective electrode can be a laminated structure of a reflective electrode and an electrode that transmits visible light (also called a transparent electrode). The transparent electrode can be called an optical adjustment layer.

[0110] The light transmittance of the transparent electrode shall be 40% or more. For example, it is preferable to use an electrode in the light-emitting element 110 that has a transmittance of 40% or more for visible light (light with a wavelength of 400 nm or more and less than 750 nm). 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 -2It is preferable that the value be Ωcm or less. Furthermore, when a light-emitting element that emits near-infrared light is used in the display device, it is preferable that the transmittance and reflectance of these electrodes for near-infrared light (light with a wavelength of 750 nm to 1300 nm) are also within the above numerical range.

[0111] An insulating layer 131 is provided to cover the ends of the pixel electrode 111R, the ends of the pixel electrode 111G, the ends of the pixel electrode 111B, and the ends of the pixel electrode 111PD. The ends of the insulating layer 131 are preferably tapered. The insulating layer 131 may be omitted if it is not needed.

[0112] For example, the hole injection layer 113R, hole injection layer 113G, hole injection layer 113B, and hole transport layer 115PD each have a region in contact with the upper surface of the pixel electrode 111 and a region in contact with the surface of the insulating layer 131. Furthermore, the ends of the hole injection layer 113R, the ends of the hole injection layer 113G, the ends of the hole injection layer 113B, and the ends of the hole transport layer 115PD are located on the insulating layer 131.

[0113] As shown in Figure 6A, a gap is provided between light-emitting elements 110 that emit light of different colors, for example, between two light-emitting layers 117. In this way, it is preferable that light-emitting layers 117R, 117G, and 117B are arranged so that they do not touch each other. This effectively prevents current from flowing through two adjacent light-emitting layers 117 and causing unintended light emission. As a result, the contrast of the display device 10 can be increased, and thus the display quality of the display device 10 can be improved.

[0114] A protective layer 125 is provided on the common electrode 123. The protective layer 125 has the function of preventing impurities such as water from diffusing to each light-emitting element from above.

[0115] The protective layer 125 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 nitride film, silicon nitride film, aluminum oxide film, aluminum oxide nitride film, and hafnium oxide film. Alternatively, semiconductor materials such as indium gallium oxide and indium gallium zinc oxide may be used as the protective layer 125.

[0116] In this specification, a silicon oxide-nitride film refers to a film in which the oxygen content is greater than the nitrogen content. Similarly, a silicon nitride-oxide film refers to a film in which the nitrogen content is greater than the oxygen content.

[0117] Furthermore, a laminated film of an inorganic insulating film and an organic insulating film can also be used as the protective layer 125. For example, it is preferable to have a configuration in which an organic insulating film is sandwiched between a pair of inorganic insulating films. It is also 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 125 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 125.

[0118] Figure 6C shows an example of the cross-sectional configuration of the display device 10 in the Y direction, specifically showing an example of the cross-sectional configuration of the light-emitting element 110R and the light-receiving element 150. Note that the light-emitting elements 110G and 110B can also be arranged in the Y direction in the same way as the light-emitting element 110R.

[0119] Figure 6D shows a connection portion 130 where the connecting electrode 111C and the common electrode 123 are electrically connected. In the connection portion 130, the common electrode 123 is placed in contact with the connecting electrode 111C, and a protective layer 125 is provided to cover the common electrode 123. In addition, an insulating layer 131 is provided to cover the end of the connecting electrode 111C.

[0120] Figure 6E shows an example of the cross-sectional configuration of the light-receiving element 150, as well as an example of the cross-sectional configuration of the light-emitting element 110IR. The light-emitting element 110IR includes a pixel electrode 111IR, a hole injection layer 113IR, a hole transport layer 115IR, a light-emitting layer 117IR, an electron transport layer 119IR, a common layer 121, and a common electrode 123.

[0121] The light-emitting layer 117IR of the light-emitting element 110IR has a light-emitting organic compound that emits light having intensity in at least the infrared wavelength range. For example, the light-emitting layer 117IR has a light-emitting organic compound that emits light having intensity in the near-infrared wavelength range. If the display device 10 has a light-emitting element 110IR, the light-receiving layer 157 of the light-receiving element 150 has an organic compound that has detection sensitivity in the wavelength range of, for example, infrared light, for example, near-infrared light.

[0122] [Example of manufacturing method] In the following section, an example of a method for manufacturing a display device according to one embodiment of the present invention will be described with reference to the drawings. Here, the method for manufacturing the display device 10 shown in Figure 2A and Figures 6A to 6D will be described as an example. Figures 7A to 10C are schematic cross-sectional views of each step in the method for manufacturing the display device illustrated below. Figures 7A to 10C show the cross-sections corresponding to the dashed-dotted lines A1-A2, B1-B2, and D1-D2 in Figure 2A.

[0123] Furthermore, thin films (insulating films, semiconductor films, conductive films, etc.) that constitute the display device can be formed using sputtering, chemical vapor deposition (CVD), vacuum deposition, pulsed laser deposition (PLD), or 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).

[0124] Furthermore, thin films (insulating films, semiconductor films, conductive films, etc.) that constitute the display device can be formed by methods such as spin coating, dip coating, spray coating, inkjet printing, dispensing, screen printing, offset printing, doctor knife method, slit coating, roll coating, curtain coating, or knife coating.

[0125] Furthermore, when processing the thin film that constitutes the display device, for example, photolithography can be used. Alternatively, the thin film may be processed by nanoimprint lithography, sandblasting, or lift-off lithography.

[0126] 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, for example by etching, 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.

[0127] 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 light sources such as ultraviolet light, KrF laser light, or ArF laser light can also be used. 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 for exposure. Using extreme ultraviolet light, X-rays, or an electron beam is preferable because it enables extremely fine processing. Note that a photomask is not required when exposure is performed by scanning a beam such as an electron beam.

[0128] For etching thin films, dry etching, wet etching, or sandblasting methods can be used.

[0129] To fabricate the display device 10, first, a substrate 101 is prepared. As the substrate 101, a substrate with at least sufficient heat resistance to withstand subsequent heat treatment can be used. When using an insulating substrate as the substrate 101, glass substrates, quartz substrates, sapphire substrates, ceramic substrates, or organic resin substrates can be used. Alternatively, semiconductor substrates such as single-crystal semiconductor substrates, polycrystalline semiconductor substrates, compound semiconductor substrates such as silicon-germanium, or SOI substrates made from silicon or silicon carbide can be used.

[0130] Next, pixel electrodes 111R, 111G, 111B, 111PD, and 111C are formed on the substrate 101. First, a conductive film to be used as the pixel electrode is deposited, a resist mask is formed by photolithography, and unnecessary parts of the conductive film are removed by etching. After that, the resist mask is removed to form the pixel electrodes 111R, 111G, and 111B.

[0131] When using a conductive film that is reflective to visible light as each pixel electrode, it is preferable to use a material (for example, silver or aluminum) that has the highest possible reflectivity across the entire wavelength range of visible light. This not only improves the light extraction efficiency of the light-emitting element but also enhances color reproduction.

[0132] Next, an insulating layer 131 is formed by covering the ends of the pixel electrodes 111R, 111G, 111B, and 111PD (Figure 7A). An organic insulating film or an inorganic insulating film can be used as the insulating layer 131. It is preferable that the ends of the insulating layer 131 be tapered in order to improve the step coverage of the subsequent film. In particular, when using an organic insulating film, it is preferable to use a photosensitive material because it is easier to control the shape of the ends depending on the exposure and development conditions. An inorganic insulating film may also be used as the insulating layer 131. By using an inorganic insulating film as the insulating layer 131, the display device 10 can be made into a high-definition display device.

[0133] Next, a functional film 113Rf, which will later become the hole injection layer 113R, is deposited on the pixel electrode 111R, pixel electrode 111G, pixel electrode 111B, pixel electrode 111PD, and the insulating layer 131. Subsequently, a functional film 115Rf, which will become the hole transport layer 115R, an emissive film 117Rf, which will become the emissive layer 117R, and a functional film 119Rf, which will become the electron transport layer 119R, are deposited sequentially on the functional film 113Rf. The functional films 113Rf, 115Rf, 117Rf, and 119Rf can be formed by, for example, vapor deposition, sputtering, or inkjet. However, the above-described film formation methods can be used as appropriate.

[0134] It is preferable that the functional films 113Rf, 115Rf, 117Rf, and 119Rf are formed so as not to be located on the connecting electrode 111C. For example, when the functional films 113Rf, 115Rf, 117Rf, and 119Rf are formed by vapor deposition or sputtering, it is preferable to use a shielding mask to prevent the functional films 113Rf, 115Rf, 117Rf, and 119Rf from being deposited on the connecting electrode 111C.

[0135] Next, a sacrificial film 141a is formed on the functional film 119Rf. The sacrificial film 141a can also be provided in contact with the upper surface of the connecting electrode 111C.

[0136] The sacrificial film 141a can be a film with high resistance to etching of the functional film 119Rf, the light-emitting film 117Rf, the functional film 115Rf, and the functional film 113Rf, i.e., a film with a high etching selectivity ratio. Furthermore, the sacrificial film 141a can be a film with a high etching selectivity ratio with respect to protective films such as the protective film 143a described later. In addition, the sacrificial film 141a can be a film that can be removed by a wet etching method that causes minimal damage to the functional film 119Rf, the light-emitting film 117Rf, the functional film 115Rf, and the functional film 113Rf.

[0137] As the sacrificial film 141a, for example, a metal film, alloy film, metal oxide film, semiconductor film, or an inorganic film such as an inorganic insulating film can be used. The sacrificial film 141a can be formed by various film deposition methods such as sputtering, evaporation, CVD, or ALD.

[0138] As the sacrificial film 141a, for example, metal materials such as gold, silver, platinum, magnesium, nickel, tungsten, chromium, molybdenum, iron, cobalt, copper, palladium, titanium, aluminum, yttrium, zirconium, and tantalum, or alloy materials containing such metal materials, can be used. In particular, it is preferable to use low-melting-point materials such as aluminum or silver.

[0139] Furthermore, metal oxides such as indium gallium zinc oxide (In-Ga-Zn oxide, also written as IGZO) can be used as the sacrificial film 141a. In addition, indium oxide, indium zinc oxide (In-Zn oxide), indium tin 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), or indium gallium tin zinc oxide (In-Ga-Sn-Zn oxide) can be used. Alternatively, indium tin oxide containing silicon can also be used.

[0140] 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.

[0141] Furthermore, inorganic insulating materials such as aluminum oxide, hafnium oxide, or silicon oxide can be used as the sacrificial film 141a.

[0142] Furthermore, it is preferable to use a material that is soluble in a chemically stable solvent relative to the functional film 119Rf as the sacrificial film 141a. In particular, a material soluble in water or alcohol can be suitably used for the sacrificial film 141a. When forming the sacrificial film 141a, it is preferable to apply it using a wet film formation method while dissolved in a solvent such as water or alcohol, and then perform a heat treatment to evaporate the solvent. At this time, performing the heat treatment under a reduced pressure atmosphere is preferable because it allows the solvent to be removed at a low temperature and in a short time, thereby reducing thermal damage to the functional film 119Rf, the light-emitting film 117Rf, the functional film 115Rf, and the functional film 113Rf.

[0143] Wet film deposition methods that can be used to form the sacrificial film 141a include spin coating, dip coating, spray coating, inkjet printing, dispensing, screen printing, offset printing, doctor knife method, slit coating, roll coating, curtain coating, or knife coating.

[0144] As the sacrificial film 141a, organic materials such as polyvinyl alcohol (PVA), polyvinyl butyral, polyvinylpyrrolidone, polyethylene glycol, polyglycerin, pullulan, water-soluble cellulose, or alcohol-soluble polyamide resin can be used.

[0145] Next, a protective film 143a is formed on the sacrificial film 141a (Figure 7B).

[0146] The protective film 143a is used as a hard mask when etching the sacrificial film 141a later. Furthermore, the sacrificial film 141a is exposed during the subsequent processing of the protective film 143a. Therefore, a combination of films with a high etching selectivity ratio for each other is selected for the sacrificial film 141a and the protective film 143a. Thus, the film that can be used for the protective film 143a can be selected according to the etching conditions for both the sacrificial film 141a and the protective film 143a.

[0147] For example, when dry etching using a fluorine-containing gas (also called a fluorine-based gas) is used to etch the protective film 143a, silicon, silicon nitride, silicon oxide, tungsten, titanium, molybdenum, tantalum, tantalum nitride, an alloy containing molybdenum and niobium, or an alloy containing molybdenum and tungsten can be used for the protective film 143a. Here, a film that allows for a high selectivity ratio for etching (i.e., a slower etching rate) compared to the dry etching using the above-mentioned fluorine-based gas is, for example, a metal oxide film such as IGZO or ITO, which can be used for the sacrificial film 141a.

[0148] However, the protective film 143a can be selected from a variety of materials depending on the etching conditions of the sacrificial film 141a and the protective film 143a. For example, it can be selected from films that can be used for the sacrificial film 141a.

[0149] Furthermore, a nitride film can be used as the protective film 143a, for example. Specifically, nitride films such as silicon nitride, aluminum nitride, hafnium nitride, titanium nitride, tantalum nitride, tungsten nitride, gallium nitride, or germanium nitride can be used.

[0150] Alternatively, an oxide film can be used as the protective film 143a. Typically, oxide films or oxynitride films such as silicon oxide, silicon oxynitride, aluminum oxide, aluminum oxynitride, hafnium oxide, and hafnium oxynitride can be used.

[0151] Furthermore, as the protective film 143a, an organic film that can be used for the light-emitting film 117Rf may be used, for example. Using such an organic film is preferable because, for example, the light-emitting film 117Rf and the film deposition apparatus can be used in common.

[0152] Next, a resist mask 145a is formed on the protective film 143a at a position overlapping with the pixel electrode 111R and at a position overlapping with the connecting electrode 111C, respectively (Figure 7C).

[0153] The resist mask 145a can use a resist material containing a photosensitive resin, such as a positive-type resist material or a negative-type resist material.

[0154] In this case, if a resist mask 145a is formed on the sacrificial film 141a without forming a protective film 143a, there is a risk that defects such as pinholes may be present in the sacrificial film 141a, causing the functional film 119Rf, for example, to dissolve due to the solvent in the resist material. Using a protective film 143a prevents such problems from occurring.

[0155] Furthermore, if a sacrificial film 141a is used that is less prone to defects such as pinholes, the resist mask 145a may be formed directly on the sacrificial film 141a without using the protective film 143a.

[0156] Next, the portion of the protective film 143a not covered by the resist mask 145a is removed by etching to form a protective layer 149a. At the same time, a protective layer 149a is also formed on the connecting electrode 111C.

[0157] When etching the protective film 143a, it is preferable to use etching conditions with a high selectivity ratio so that the sacrificial film 141a is not removed by the etching. The protective film 143a can be etched by wet etching or dry etching, but using dry etching can suppress the reduction of the pattern of the protective film 143a.

[0158] Next, remove the resist mask 145a (Figure 7D).

[0159] The resist mask 145a can be removed by wet etching or dry etching. In particular, it is preferable to remove the resist mask 145a by dry etching (also called plasma ashing) using oxygen gas as the etching gas.

[0160] In this case, the removal of the resist mask 145a is performed with the sacrificial film 141a on the functional film 119Rf, thus suppressing the impact on the functional film 119Rf, the light-emitting film 117Rf, the functional film 115Rf, and the functional film 113Rf. In particular, since contact with oxygen can adversely affect the electrical properties of the light-emitting film 117Rf, for example, this method is suitable when etching is performed using oxygen gas, such as plasma ashing.

[0161] Next, using the protective layer 149a as a mask, the portion of the sacrificial film 141a not covered by the protective layer 149a is removed by etching to form a sacrificial layer 147a (Figure 8A). At the same time, a sacrificial layer 147a is also formed on the connecting electrode 111C.

[0162] The sacrificial film 141a can be etched by wet etching or dry etching, but dry etching is preferred because it can suppress pattern reduction.

[0163] Next, the protective layer 149a is removed by etching, and a portion of the functional film 119Rf, light-emitting film 117Rf, functional film 115Rf, and functional film 113Rf that are not covered by the sacrificial layer 147a are also removed by etching to form the electron transport layer 119R, light-emitting layer 117R, hole transport layer 115R, and hole injection layer 113R (Figure 8B).

[0164] In particular, for etching the functional film 119Rf, the light-emitting film 117Rf, the functional film 115Rf, and the functional film 113Rf, it is preferable to use dry etching with an etching gas that does not contain oxygen as its main component. This suppresses deterioration of the functional film 119Rf, the light-emitting film 117Rf, the functional film 115Rf, and the functional film 113Rf, enabling the realization of a highly reliable display device. Examples of etching gases that do not contain oxygen as their main component include noble gases such as CF4, C4F8, SF6, CHF3, Cl2, H2O, BCl3, H2, or He. Alternatively, a mixed gas of the above gas and an oxygen-free diluent gas can be used as the etching gas.

[0165] Next, functional films 113Gf (which will later become the hole injection layer 113G), 115Gf (which will later become the hole transport layer 115G), 117Gf (which will later become the light-emitting layer 117G), and 119Gf (which will later become the electron transport layer 119G) are sequentially deposited on the sacrificial layer 147a, the insulating layer 131, the pixel electrode 111G, the pixel electrode 111B, and the pixel electrode 111PD. At this time, it is preferable not to provide functional films 113Gf, 115Gf, 117Gf, and 119Gf on the connecting electrode 111C.

[0166] Regarding the deposition methods for functional films 113Gf, 115Gf, 117Gf, and 119Gf, the descriptions of the deposition methods for functional films 113Rf, 115Rf, 117Rf, and 119Rf above can be applied.

[0167] Next, a sacrificial film 141b is formed on the functional film 119Gf. The sacrificial film 141b can be formed in the same manner as the sacrificial film 141a. In particular, it is preferable to use the same material for the sacrificial film 141b as for the sacrificial film 141a.

[0168] At the same time, a sacrificial film 141b is formed on the connecting electrode 111C, covering the sacrificial layer 147a.

[0169] Next, a protective film 143b is formed on the sacrificial film 141b. The protective film 143b can be formed in the same manner as the protective film 143a. In particular, it is preferable to use the same material for the protective film 143b as for the protective film 143a.

[0170] Next, a resist mask 145b is formed on the protective film 143b in the region overlapping with the pixel electrode 111G and the region overlapping with the connecting electrode 111C (Figure 8C).

[0171] The resist mask 145b can be formed in the same manner as the resist mask 145a.

[0172] Next, the portion of the protective film 143b not covered by the resist mask 145b is removed by etching to form a protective layer 149b. At the same time, a protective layer 149b is also formed on the connecting electrode 111C.

[0173] For etching of protective film 143b, the description of protective film 143a above can be applied.

[0174] Next, remove the resist mask 145a (Figure 9A). For removing the resist mask 145b, refer to the description of resist mask 145a above.

[0175] Next, using the protective layer 149b as a mask, the portion of the sacrificial film 141b not covered by the protective layer 149b is removed by etching to form the sacrificial layer 147b. At the same time, the sacrificial layer 147b is also formed on the connecting electrode 111C. The sacrificial layer 147a and the sacrificial layer 147b are stacked on the connecting electrode 111C.

[0176] For etching of the sacrificial film 141b, the description of the sacrificial film 141a above can be applied.

[0177] Next, the protective layer 149b is removed by etching, and parts of the functional film 119Gf, light-emitting film 117Gf, functional film 115Gf, and functional film 113Gf that are not covered by the sacrificial layer 147b are also removed by etching to form the electron transport layer 119G, light-emitting layer 117G, hole transport layer 115G, and hole injection layer 113G (Figure 9B).

[0178] For etching of the functional film 119Gf, light-emitting film 117Gf, functional film 115Gf, functional film 113Gf, and protective layer 149b, the descriptions for the functional film 119Rf, light-emitting film 117Rf, functional film 115Rf, functional film 113Rf, and protective layer 149a above can be applied.

[0179] In this case, the electron transport layer 119R, the light-emitting layer 117R, the hole transport layer 115R, and the hole injection layer 113R are protected by the sacrificial layer 147a, thus preventing them from being damaged during the etching process of the functional film 119Gf, light-emitting layer 117Gf, functional film 115Gf, and functional film 113Gf.

[0180] In this way, the hole injection layer 113R, hole transport layer 115R, light-emitting layer 117R, and electron transport layer 119R can be fabricated with high positional accuracy, as can the hole injection layer 113G, hole transport layer 115G, light-emitting layer 117G, and electron transport layer 119G.

[0181] The hole injection layer 113B, hole transport layer 115B, light-emitting layer 117B, electron transport layer 119B, and sacrificial layer 147c can be formed by the same process as described above (Figure 9C). Sacrificial layers 147a, 147b, and 147c are stacked on the connecting electrode 111C.

[0182] After forming the hole injection layer 113B, hole transport layer 115B, light-emitting layer 117B, electron transport layer 119B, and sacrificial layer 147c, the hole transport layer 115PD, light-receiving layer 157, electron transport layer 119PD, and sacrificial layer 147d are formed by the same process as described above (Figure 9D). Sacrificial layers 147a, 147b, 147c, and 147d are stacked on the connecting electrode 111C. Note that the electron transport layer 119PD may be omitted.

[0183] Furthermore, when manufacturing a display device having a light-emitting element 110IR, for example, after forming the hole injection layer 113B, hole transport layer 115B, light-emitting layer 117B, electron transport layer 119B, and sacrificial layer 147c, and before forming the hole transport layer 115PD, light-receiving layer 157, electron transport layer 119PD, and sacrificial layer 147d, the hole injection layer 113IR, hole transport layer 115IR, light-emitting layer 117IR, electron transport layer 119IR, and sacrificial layer are formed by the same process as described above. In this case, five sacrificial layers are stacked on the connecting electrode 111C.

[0184] Next, sacrificial layers 147a, 147b, 147c, and 147d are removed, exposing the top surfaces of electron transport layers 119R, 119G, 119B, and 119PD (Figure 10A). At the same time, the top surface of the connecting electrode 111C is also exposed.

[0185] Sacrificial layers 147a, 147b, 147c, and 147d can be removed by wet etching or dry etching. In this case, it is preferable to use a method that causes as little damage as possible to the hole injection layer 113, hole transport layer 115, light-emitting layer 117, light-receiving layer 157, and electron transport layer 119. In particular, it is preferable to use a wet etching method. For example, it is preferable to use wet etching using an aqueous solution of tetramethylammonium hydroxide (TMAH), dilute hydrofluoric acid, oxalic acid, phosphoric acid, acetic acid, nitric acid, or a mixture thereof.

[0186] Alternatively, it is preferable to remove sacrificial layers 147a, 147b, 147c, and 147d by dissolving them in a solvent such as water or alcohol. Here, various alcohols can be used to dissolve sacrificial layers 147a, 147b, 147c, and 147d, such as ethyl alcohol, methyl alcohol, isopropyl alcohol (IPA), or glycerin.

[0187] After removing sacrificial layers 147a, 147b, 147c, and 147d, it is preferable to perform a drying treatment to remove water contained inside the light-emitting layer 117R, 117G, 117B, and light-receiving layer 157, as well as water adsorbed on the surface. For example, it is preferable to perform a heat treatment 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 drying at a lower temperature.

[0188] In this way, the light-emitting layer 117R, light-emitting layer 117G, light-emitting layer 117B, and light-receiving layer 157 can be manufactured separately.

[0189] Next, a common layer 121 is formed on electron transport layer 119R, electron transport layer 119G, electron transport layer 119B, and electron transport layer 119PD. As described above, a void can be formed between the common layer 121 and the insulating layer 131.

[0190] The common layer 121 can be formed by, for example, vapor deposition, sputtering, or inkjet. When forming the common layer 121 by vapor deposition, it is preferable to use a shielding mask to prevent the common layer 121 from being formed on the connecting electrode 111C.

[0191] Next, the common layer 121 and the connecting electrode 111C are covered to form the common electrode 123 (Figure 10B).

[0192] The common electrode 123 can be formed by a film deposition method such as vapor deposition or sputtering. Alternatively, a film formed by vapor deposition and a film formed by sputtering may be laminated together. In this case, it is preferable to form the common electrode 123 so as to encompass the region where the common layer 121 is formed. That is, the edges of the common layer 121 can overlap with the common electrode 123. It is preferable to form the common electrode 123 using a shielding mask.

[0193] The common electrode 123 is electrically connected to the connecting electrode 111C outside the display unit.

[0194] Next, a protective layer 125 is formed on the common electrode 123 (Figure 10C). For forming the inorganic insulating film used in the protective layer 125, sputtering, PECVD, or ALD is preferred. The ALD method is particularly preferred because it offers excellent step coverage and is less prone to defects such as pinholes. Furthermore, for forming the organic insulating film, the inkjet method is preferred because it allows for the formation of a uniform film in the desired area.

[0195] Based on the above, the display device 10 can be manufactured.

[0196] In the above example, the common electrode 123 and the common layer 121 were formed with different upper surface shapes, but they may also be formed in the same region.

[0197] Figure 11A shows a schematic cross-sectional view after the sacrificial layer has been removed. Subsequently, as shown in Figure 11B, the common layer 121 and the common electrode 123 are formed using the same shielding mask, or without using a shielding mask. This reduces manufacturing costs compared to using different shielding masks.

[0198] In this case, as shown in Figure 11B, the connection portion 130 has a configuration in which a common layer 121 is sandwiched between the connecting electrode 111C and the common electrode 123. In this case, it is preferable to use a material with the lowest possible electrical resistance for the common layer 121. Alternatively, it is preferable to reduce the electrical resistance in the thickness direction of the common layer 121 by forming it as thin as possible. For example, by using an electron-injection or hole-injection material with a thickness of 1 nm to 5 nm, preferably 1 nm to 3 nm, for the common layer 121, the electrical resistance between the connecting electrode 111C and the common electrode 123 can be reduced to a negligible degree.

[0199] Next, as shown in Figure 11C, a protective layer 125 is formed. At this time, it is preferable to provide the protective layer 125 so as to cover the ends of the common electrode 123 and the ends of the common layer 121, as shown in Figure 11C. This effectively prevents the diffusion of impurities such as water or oxygen from the outside to the common layer 121 and the interface between the common layer 121 and the common electrode 123.

[0200] The above is an explanation of one example of a method for manufacturing a display device.

[0201] As described above, in the method for manufacturing a display device according to one aspect of the present invention, the light-emitting elements 110 can be differentiated without using a shadow mask such as a metal mask. As a result, the sub-pixels can be miniaturized and the aperture ratio of the pixels can be increased compared to when the light-emitting elements 110 are differentiated using a shadow mask. Furthermore, since the light-emitting layer 117 can be differentiated, a display device with extremely vivid colors, high contrast, and high display quality can be realized.

[0202] By miniaturizing subpixels, subpixels that do not contribute to display can be provided on pixels. For example, subpixels having a light-receiving element 150 can be provided on pixels, and subpixels having an infrared light-emitting element 110IR can be provided on pixels. In one embodiment of the present invention, even when subpixels that do not contribute to display are provided on pixels, the pixel density can be suppressed to a small value. For example, the pixel density can be 400 ppi or more, 1000 ppi or more, 3000 ppi or more, or 5000 ppi or more.

[0203] [Configuration Example 2] The following describes a configuration example of a display device that differs in some aspects from the above Configuration Example 1. In the following sections, explanations of parts that overlap with the above may be omitted.

[0204] Figure 12A is a schematic top view showing an example configuration of the display device 10, and is a modified version of the display device 10 shown in Figure 2A. The display device 10 shown in Figure 12A differs from the display device 10 shown in Figure 2A in the shape of the common layer 121 and the shape of the common electrode 123. In Figure 12A, the outlines of the common electrode 123 and the common layer 121 are shown with dashed lines.

[0205] Figure 12B is a cross-sectional view corresponding to the dashed line C3-C4 in Figure 12A, showing a cross-section in the Y direction. As shown in Figures 12A and 12B, the common layer 121 and the common electrode 123 are separated between adjacent pixels. In other words, the common layer 121 and the common electrode 123 have their ends in the region that overlaps with the insulating layer 131.

[0206] Figure 12C is an enlarged cross-sectional view extracted from Figure 12B, showing a portion of the light-receiving element 150 and light-emitting element 110R provided in adjacent pixels. As shown in Figure 12C, a recess may be formed on a portion of the upper surface of the insulating layer 131. In this case, it is preferable that the protective layer 125 be provided in contact with the surface of the recess in the insulating layer 131. This is preferable because it increases the contact area between the insulating layer 131 and the protective layer 125, improving their adhesion.

[0207] Furthermore, as shown in Figure 12C, a gap (also called a void or space) 127 may be provided above the insulating layer 131. The gap 127 is formed during the deposition of the protective layer 125 due to the high aspect ratio of the openings separating adjacent pixels. The gap 127 may be under reduced pressure or atmospheric pressure. It may also contain gases such as air, nitrogen, noble gases, or deposition gases used for deposition of the protective layer 125.

[0208] Although not shown here, the same configuration can be applied to the light-emitting element 110G and the light-emitting element 110B.

[0209] Figure 13A is a schematic top view showing an example configuration of the display device 10, and is a modified version of the display device 10 shown in Figure 12A. Figure 13B is a cross-sectional view corresponding to the dashed line C5-C6 in Figure 13A, and shows a cross-section in the Y direction. The display device 10 shown in Figures 13A and 13B differs from the display device 10 shown in Figures 12A and 12B in that the common layer 121 and common electrode 123 are separated not only between adjacent pixels but also between identical pixels.

[0210] The configuration examples illustrated in this embodiment, and the corresponding drawings, etc., can be appropriately combined with other configuration examples or drawings, etc., at least in part.

[0211] This embodiment can be implemented in appropriate combination with other embodiments described herein, at least in part.

[0212] (Embodiment 2) This embodiment describes an example of the configuration of a display device according to one aspect of the present invention.

[0213] [Configuration Example 1] Figure 14 is a perspective view showing an example configuration of the display device 100. The display device 100 has a configuration in which substrate 151 and substrate 152 are bonded together. In Figure 14, substrate 152 is shown with a dashed line.

[0214] The display device 100 includes a display unit 162, a circuit 164, and wiring 165, etc. Figure 14 also shows an example in which an IC (integrated circuit) 173 and an FPC 172 are mounted on the display device 100. Therefore, the configuration shown in Figure 14 can also be described as a display module having a display device, an IC, and an FPC.

[0215] Circuit 164 can be, for example, a gate driver. Signals and power can be supplied to circuit 164, etc., via wiring 165. These signals and power can be input to wiring 165 from outside the display device 10, for example, via FPC 172. Alternatively, these signals and power can be generated by IC 173 and output to wiring 165.

[0216] Figure 14 shows an example in which IC 173 is mounted on substrate 151 using the COG (Chip On Glass) method, but the TCP (Tape Carrier Package) method or COF (Chip On Film) method may also be used.

[0217] Figure 15 shows an example of cross-sections of a portion of the region including the FPC 172, a portion of the region including the circuit 164, a portion of the region including the display unit 162, and a portion of the region including the end of the display device 100 shown in Figure 14. The display device 100 shown in Figure 15 is referred to as display device 100A.

[0218] The display device 100A has transistors 201, 141, 142, light-emitting element 110, and light-receiving element 150, etc., between substrates 151 and 152.

[0219] The substrate 152 and the insulating layer 214 are bonded together via an adhesive layer 242. A solid sealing structure or a hollow sealing structure can be applied to encapsulate the light-emitting element 110 and the light-receiving element 150. The space 143 surrounded by the substrate 152, the adhesive layer 242, and the insulating layer 214 is filled with an inert gas (nitrogen or argon, etc.), and a hollow sealing structure is applied. The adhesive layer 242 may be provided overlapping the light-emitting element 110. Alternatively, the region surrounded by the substrate 152, the adhesive layer 242, and the insulating layer 214 may be filled with a resin different from that of the adhesive layer 242.

[0220] The pixel electrode 111 of the light-emitting element 110 is electrically connected to the conductive layer 222b of the transistor 142 through an opening provided in the insulating layer 214. The transistor 142 has the function of controlling the driving of the light-emitting element 110. The pixel electrode 111PD of the light-receiving element 150 is electrically connected to the conductive layer 222b of the transistor 141 through an opening provided in the insulating layer 214.

[0221] The light emitted by the light-emitting element 110 is emitted towards the substrate 152. Light is also incident on the light-receiving element 150 through the substrate 152 and the space 143. It is preferable to use a material with high transmittance to visible light and infrared light for the substrate 152.

[0222] A light-shielding layer 148 is provided on the surface of the substrate 152 that faces the substrate 151. The light-shielding layer 148 has openings at positions overlapping with the light-receiving element 150 and at positions overlapping with the light-emitting element 110. In addition, a filter 146 that cuts ultraviolet light is provided at the position overlapping with the light-receiving element 150. Note that a configuration without the filter 146 is also possible.

[0223] Transistors 201, 141, and 142 are all formed on the substrate 151. These transistors can be manufactured using the same materials and the same process.

[0224] Insulating layers 211, 213, 215, and 214 are provided on the substrate 151 in this order. A portion of insulating layer 211 functions as a gate insulating layer for each transistor. A portion of insulating layer 213 functions as a gate insulating layer for each transistor. Insulating layer 215 is provided covering the transistors. Insulating layer 214 is provided covering the transistors and functions as a planarization layer. The number of gate insulating layers and insulating layers covering the transistors are not limited and may be a single layer or two or more layers, respectively.

[0225] It is preferable to use a material that does not easily allow impurities such as water or 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.

[0226] It is preferable to use an inorganic insulating film for insulating layer 211, insulating layer 213, and insulating layer 215. As the inorganic insulating film, for example, silicon nitride film, silicon oxynitride film, silicon oxide film, silicon nitride oxide film, aluminum oxide film, or aluminum nitride film can be used. 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, or neodymium oxide film may be used. Furthermore, two or more of the above insulating films may be laminated and used.

[0227] For the insulating layer 214, which functions as a planarization layer, it is preferable to use an organic insulating film. Examples of materials that can be used as the organic insulating film include acrylic resins, polyimide resins, epoxy resins, polyamide resins, polyimidoamide resins, siloxane resins, benzocyclobutene resins, phenolic resins, and precursors of these resins.

[0228] Here, organic insulating films often have lower barrier properties against impurities compared to inorganic insulating films. Therefore, it is preferable that the organic insulating film has an opening near the edge of the display device 100A. This suppresses the diffusion of impurities from the edge of the display device 100A through the organic insulating film. Alternatively, the organic insulating film may be formed such that its edge is located inward from the edge of the display device 100A, so that the organic insulating film is not exposed at the edge of the display device 100A.

[0229] In the region 228 shown in Figure 15, an opening is formed in the insulating layer 214. This prevents impurities from diffusing from the outside to the display unit 162 through the insulating layer 214, even when an organic insulating film is used for the insulating layer 214. Therefore, the reliability of the display device 100A can be improved.

[0230] Transistors 201, 141, and 142 each 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.

[0231] The transistor structure of the display device of this embodiment is not particularly limited. For example, a planar transistor, a staggered transistor, or an inverse staggered transistor 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.

[0232] Transistors 201, 141, and 142 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, one of the two gates may be given a potential to control the threshold voltage of the transistor, and the other may be given a potential for driving.

[0233] 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.

[0234] The semiconductor layer of the transistor preferably contains a metal oxide (also called an oxide semiconductor). Alternatively, the semiconductor layer of the transistor may contain silicon. Examples of silicon include amorphous silicon or crystalline silicon (such as low-temperature polysilicon or single-crystal silicon).

[0235] When the semiconductor layer has a metal oxide, the metal oxide preferably contains at least indium or zinc, as described above. It is particularly preferable that it contains indium and zinc. In addition, it is preferable that it contains aluminum, gallium, yttrium, or tin. It may also contain one or more of the following: boron, silicon, titanium, iron, nickel, germanium, zirconium, molybdenum, lanthanum, cerium, neodymium, hafnium, tantalum, tungsten, magnesium, cobalt, etc.

[0236] The transistors in circuit 164 and the transistors in display unit 162 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 162 may all be the same or there may be two or more different structures.

[0237] A connection portion 204 is provided in the area of ​​substrate 151 where substrate 152 does not overlap. At the connection portion 204, wiring 165 is electrically connected to FPC 172 via conductive layer 166 and connection layer 244. The upper surface of the connection portion 204 exposes the conductive layer 166, which is obtained by processing the same conductive film as the pixel electrode 111. This allows the connection portion 204 and FPC 172 to be electrically connected via the connection layer 244.

[0238] Various optical components can be placed on the outside of the substrate 152. Examples of optical components include polarizing plates, phase difference plates, light diffusion layers (diffusion films, etc.), anti-reflective layers, and light-gathering films. In addition, an antistatic film to suppress the adhesion of dust, a water-repellent film to make it difficult for dirt to adhere, a hard coat film to suppress the occurrence of scratches during use, or an impact-absorbing layer may be placed on the outside of the substrate 152.

[0239] Substrates 151 and 152 can be made of glass, quartz, ceramic, sapphire, resin, or the like.

[0240] Various types of curing adhesives can be used as the adhesive layer, including UV-curing adhesives, reaction-curing adhesives, thermosetting adhesives, or anaerobic adhesives. Examples of these adhesives include epoxy resins, acrylic resins, silicone resins, phenolic resins, polyimide resins, imide resins, PVC (polyvinyl chloride) resins, PVB (polyvinyl butyral) resins, or EVA (ethylene vinyl acetate) resins. Materials with low moisture permeability, such as epoxy resins, are particularly preferred. Two-component mixed resins may also be used. Alternatively, for example, an adhesive sheet may be used.

[0241] As the connecting layer 244, an anisotropic conductive film (ACF) or an anisotropic conductive paste (ACP) can be used.

[0242] 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, and tungsten, as well as alloys mainly composed of these metals. Films containing these materials can be used in single-layer or multilayer structures.

[0243] Furthermore, conductive oxides such as indium oxide, indium tin oxide, indium zinc oxide, zinc oxide, and zinc oxide containing gallium can be used as light-transmitting conductive materials, or graphene can be used. Alternatively, metallic materials such as gold, silver, platinum, magnesium, nickel, tungsten, chromium, molybdenum, iron, cobalt, copper, palladium, and titanium, as well as alloy materials containing such metallic materials, can be used. Alternatively, nitrides of such metallic materials (e.g., titanium nitride) may be used. When using metallic materials, alloy materials (or their nitrides), it is preferable to make them thin enough to be light-transmitting. In addition, 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. These can also be used for conductive layers of various wirings and electrodes that constitute a display device, and for conductive layers of display elements (conductive layers that function as pixel electrodes or common electrodes).

[0244] Examples of insulating materials that can be used for each insulating layer include resins such as acrylic resin and epoxy resin, and inorganic insulating materials such as silicon oxide, silicon oxide nitride, silicon nitride, silicon nitride, and aluminum oxide.

[0245] [Configuration Example 2] Figure 16 is a cross-sectional view showing an example configuration of the display device 100B, which is a modified version of the display device 100A. The display device 100B differs from the display device 100A in that it has a substrate 153, an adhesive layer 155, and an insulating layer 212 instead of substrate 151, and a substrate 154, an adhesive layer 156, and an insulating layer 158 instead of substrate 152.

[0246] In the display device 100B, the substrate 153 and the insulating layer 212 are bonded together by an adhesive layer 155. Additionally, the substrate 154 and the insulating layer 158 are bonded together by an adhesive layer 156.

[0247] When manufacturing the display device 100B shown in Figure 16, first, a first manufacturing substrate on which an insulating layer 212, each transistor, a light-emitting element 110, and a light-receiving element 150 are provided, and a second manufacturing substrate on which an insulating layer 158, a light-shielding layer 148, and a filter 146 are provided, are bonded together with an adhesive layer 242. Then, the first manufacturing substrate is peeled off and a substrate 153 is attached to the exposed surface using an adhesive layer 155. This transfers each component formed on the first manufacturing substrate to the substrate 153. Similarly, the second manufacturing substrate is peeled off and a substrate 154 is attached to the exposed surface using an adhesive layer 156. This transfers each component formed on the second manufacturing substrate to the substrate 154. It is preferable that both substrates 153 and 154 are flexible. This allows the display device 100B to be flexible. In other words, the display device 100B can be made into a flexible display.

[0248] Insulating layer 212 and insulating layer 158 can be made of an inorganic insulating film that can be used for insulating layer 211, insulating layer 213, and insulating layer 215, respectively.

[0249] [Configuration Example 3] Figure 17 is a cross-sectional view showing an example configuration of the display device 100C. The display device 100C includes a substrate 301, a light-emitting element 110, a light-receiving element 150, a capacitor 240, and a transistor 310. The substrate 301 corresponds, for example, to the substrate 151 in Figure 14.

[0250] 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 a source or drain. The insulating layer 314 is provided covering the side surface of the conductive layer 311.

[0251] Furthermore, an element isolation layer 315 is provided between two adjacent transistors 310 so as to be embedded in the substrate 301.

[0252] Furthermore, an insulating layer 261 is provided to cover the transistor 310, and a capacitance 240 is provided on the insulating layer 261.

[0253] Capacitor 240 has a conductive layer 241, a conductive layer 245, and an insulating layer 243 located between them. The conductive layer 241 functions as one electrode of the capacitor 240, the conductive layer 245 functions as the other electrode of the capacitor 240, and the insulating layer 243 functions as the dielectric of the capacitor 240.

[0254] 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.

[0255] An insulating layer 255 is provided covering the capacitance 240, and a light-emitting element 110 and a light-receiving element 150 are provided on the insulating layer 255. A protective layer 125 is provided on the light-emitting element 110 and the light-receiving element 150, and a substrate 420 is bonded to the upper surface of the protective layer 125 by a resin layer 419. The substrate 420 corresponds to, for example, the substrate 152 in Figure 14.

[0256] The pixel electrode 111 of the light-emitting element 110 and the pixel electrode 111PD of the light-receiving element 150 are electrically connected to either the source or drain of the transistor 310 by an insulating layer 255, a plug 256 embedded in the insulating layer 243, a conductive layer 241 embedded in the insulating layer 254, and a plug 271 embedded in the insulating layer 261.

[0257] [Configuration Example 4] FIG. 18 is a cross-sectional view showing a configuration example of the display device 100D. The display device 100D is mainly different from the display device 100C in that the configuration of the transistor is different. Note that the description of the same parts as those of the display device 100C may be omitted.

[0258] The transistor 320 is a transistor (hereinafter also referred to as an OS transistor) in which a metal oxide is applied to a semiconductor layer in which a channel is formed.

[0259] The transistor 320 includes 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.

[0260] The substrate 331 corresponds to, for example, the substrate 151 in FIG. 14. As the substrate 331, an insulating substrate or a semiconductor substrate can be used.

[0261] 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 into the transistor 320 and oxygen from desorbing from the semiconductor layer 321 to the insulating layer 332 side. As the insulating layer 332, for example, a film such as an aluminum oxide film, a hafnium oxide film, or a silicon nitride film, in which hydrogen or oxygen diffuses less easily than a silicon oxide film, can be used.

[0262] A conductive layer 327 is provided on the insulating layer 332, and an insulating layer 326 is provided to cover the conductive layer 327. The conductive layer 327 functions as the first gate electrode of the transistor 320, and a part 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 a portion of the insulating layer 326 that contacts the semiconductor layer 321. The upper surface of the insulating layer 326 is preferably flattened.

[0263] The semiconductor layer 321 is provided on the insulating layer 326. The semiconductor layer 321 preferably has a metal oxide film having semiconductor characteristics.

[0264] A pair of conductive layers 325 are provided in contact with the semiconductor layer 321 and function as source and drain electrodes.

[0265] Furthermore, an insulating layer 328 is provided covering the top and side surfaces of the 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. As the insulating layer 328, an insulating film similar to that of the insulating layer 332 can be used.

[0266] An opening is provided in the insulating layer 328 and the insulating layer 264 that reaches the semiconductor layer 321. Inside this opening, the insulating layer 323 and the conductive layer 324 are embedded, in contact with the sides of the insulating layer 264, the insulating layer 328, and the conductive layer 325, as well as the upper surface of the semiconductor layer 321. The conductive layer 324 functions as a second gate electrode, and the insulating layer 323 functions as a second gate insulating layer.

[0267] The upper surfaces of the conductive layer 324, the insulating layer 323, and the insulating layer 264 are flattened so that their heights are roughly the same, and the insulating layer 329 and insulating layer 265 are provided covering them.

[0268] 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.

[0269] 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, 264, and 328. Here, it is preferable that the plug 274 has a conductive layer 274a that covers the sides of the openings of each 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.

[0270] The configuration from the insulating layer 254 to the substrate 420 in the display device 100D is the same as that of the display device 100C.

[0271] [Configuration Example 5] Figure 19 is a cross-sectional view showing an example of the configuration of the display device 100E. The display device 100E 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. Note that parts that are the same as those of the display device 100C or the display device 100D may be omitted from the explanation.

[0272] 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.

[0273] 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.

[0274] This configuration allows for the formation of not only pixel circuits but also drive circuits and other components directly beneath the light-emitting elements, making it possible to miniaturize the display device compared to cases where the drive circuits are located around the display unit.

[0275] The configuration examples illustrated in this embodiment, and the corresponding drawings, etc., can be appropriately combined with other configuration examples or drawings, etc., at least in part.

[0276] This embodiment can be implemented in appropriate combination with other embodiments described herein, at least in part.

[0277] (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.

[0278] <Example of light-emitting element configuration> As shown in Figure 20A, the light-emitting element has an EL layer 686 between a pair of electrodes (electrode 672, electrode 688). The EL layer 686 can be composed of multiple layers, such as layer 4420, light-emitting layer 4411, and layer 4430. Layer 4420 may include, for example, a layer containing a material with high electron injection properties (electron injection layer) and a layer containing a material with high electron transport properties (electron transport layer). Light-emitting layer 4411 may include, for example, a light-emitting compound. Layer 4430 may include, for example, a layer containing a material with high hole injection properties (hole injection layer) and a layer containing a material with high hole transport properties (hole transport layer).

[0279] A configuration having a layer 4420, a light-emitting layer 4411, and a layer 4430 provided between a pair of electrodes can function as a single light-emitting unit, and in this specification, the configuration of FIG. 20A is referred to as a single structure.

[0280] Further, FIG. 20B is a modified example of the EL layer 686 included in the light-emitting element shown in FIG. 20A. Specifically, the light-emitting element shown in FIG. 20B includes a layer 4430-1 on an electrode 672, a layer 4430-2 on the layer 4430-1, a light-emitting layer 4411 on the layer 4430-2, a layer 4420-1 on the light-emitting layer 4411, a layer 4420-2 on the layer 4420-1, and an electrode 688 on the layer 4420-2. For example, when the electrode 672 is an anode and the electrode 688 is a cathode, the layer 4430-1 functions as a hole injection layer, the layer 4430-2 functions as a hole transport layer, the layer 4420-1 functions as an electron transport layer, and the layer 4420-2 functions as an electron injection layer. Or, when the electrode 672 is a cathode and the electrode 688 is an anode, the layer 4430-1 functions as an electron injection layer, the layer 4430-2 functions as an electron transport layer, the layer 4420-1 functions as a hole transport layer, and the layer 4420-2 functions as a hole injection layer. By adopting such a layer structure, carriers can be efficiently injected into the light-emitting layer 4411, and the efficiency of carrier recombination in the light-emitting layer 4411 can be increased.

[0281] Note that a configuration in which a plurality of light-emitting layers (light-emitting layer 4411, light-emitting layer 4412, light-emitting layer 44憨いけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけけ​​​​​​​Furthermore, in Figures 20C and 20D, as shown in Figure 20B, layer 4420 and layer 4430 may be a laminated structure consisting of two or more layers.

[0284] Furthermore, when comparing the single structure, tandem structure, and SBS structure described above, power consumption can be reduced in the order of SBS structure, tandem structure, and single structure. If you want to keep power consumption low, the SBS structure is preferable. On the other hand, the single structure and tandem structure are preferable because their manufacturing process is simpler than that of the SBS structure, which can lead to lower manufacturing costs or higher manufacturing yields.

[0285] The light-emitting color of the light-emitting element can be red, green, blue, cyan, magenta, yellow, or white, depending on the material constituting the EL layer 686. Furthermore, the color purity can be further enhanced by adding a microcavity structure to the light-emitting element.

[0286] A light-emitting element that emits white light preferably has a configuration that includes two or more types of light-emitting materials in its light-emitting layer. To obtain white light emission, it is sufficient to select light-emitting materials 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.

[0287] The light-emitting layer preferably contains two or more light-emitting materials that emit light such as R (red), G (green), B (blue), Y (yellow), or O (orange).

[0288] The configuration examples illustrated in this embodiment, and the corresponding drawings, etc., can be appropriately combined with other configuration examples or drawings, etc., at least in part.

[0289] This embodiment can be implemented in appropriate combination with other embodiments described herein, at least in part.

[0290] (Embodiment 4) This embodiment describes the detailed configuration of a light-emitting element, a light-receiving element, and a light-receiving element that can be used in a display device according to one aspect of the present invention.

[0291] A display device according to one aspect of the present invention may be a top-emission type that emits light in the direction opposite to the substrate on which the light-emitting element is formed, a bottom-emission type that emits light toward the substrate on which the light-emitting element is formed, or a dual-emission type that emits light on both sides.

[0292] In this embodiment, a top-emission type display device will be used as an example for explanation.

[0293] In this specification, unless otherwise specified, when describing a configuration having multiple elements (such as light-emitting elements or light-emitting layers), the letters will be omitted when describing matters common to each element. For example, when describing matters common to light-emitting layers 383R and 383G, etc., it may be written as light-emitting layer 383.

[0294] The display device 380A shown in Figure 21A includes a light-receiving element 370PD, a light-emitting element 370R that emits red (R) light, a light-emitting element 370G that emits green (G) light, and a light-emitting element 370B that emits blue (B) light.

[0295] Each light-emitting element has a pixel electrode 371, a hole injection layer 381, a hole transport layer 382, ​​a light-emitting layer, an electron transport layer 384, an electron injection layer 385, and a common electrode 375 stacked in this order. Light-emitting element 370R has a light-emitting layer 383R, light-emitting element 370G has a light-emitting layer 383G, and light-emitting element 370B has a light-emitting layer 383B. Light-emitting layer 383R has a light-emitting material that emits red light, light-emitting layer 383G has a light-emitting material that emits green light, and light-emitting layer 383B has a light-emitting material that emits blue light.

[0296] The light-emitting element is an electroluminescent element that emits light towards the common electrode 375 when a voltage is applied between the pixel electrode 371 and the common electrode 375.

[0297] The photodetector 370PD has a pixel electrode 371, a hole injection layer 381, a hole transport layer 382, ​​an active layer 373, an electron transport layer 384, an electron injection layer 385, and a common electrode 375 stacked in this order.

[0298] The light-receiving element 370PD is a photoelectric conversion element that receives light incident from outside the display device 380A and converts it into an electrical signal.

[0299] In this embodiment, both the light-emitting element and the light-receiving element are described as having a pixel electrode 371 functioning as the anode and a common electrode 375 functioning as the cathode. In other words, the light-receiving element can detect light incident on it, generate an electric charge, and extract it as an electric current by driving it with a reverse bias applied between the pixel electrode 371 and the common electrode 375.

[0300] In the display device of this embodiment, an organic compound is used for the active layer 373 of the light-receiving element 370PD. The layers of the light-receiving element 370PD other than the active layer 373 can have the same configuration as those of the light-emitting element. Therefore, by simply adding a step of forming the active layer 373 to the manufacturing process of the light-emitting element, the light-receiving element 370PD can be formed in parallel with the formation of the light-emitting element. Furthermore, the light-emitting element and the light-receiving element 370PD can be formed on the same substrate. Thus, the light-receiving element 370PD can be incorporated into the display device without significantly increasing the manufacturing process.

[0301] In the display device 380A, an example is shown where the light-receiving element 370PD and the light-emitting element have a common configuration, except that the active layer 373 of the light-receiving element 370PD and the light-emitting layer 383 of the light-emitting element are manufactured separately. However, the configuration of the light-receiving element 370PD and the light-emitting element is not limited to this. In addition to the active layer 373 and the light-emitting layer 383, the light-receiving element 370PD and the light-emitting element may have layers that are manufactured separately from each other. It is preferable that the light-receiving element 370PD and the light-emitting element have one or more layers that are used in common (common layers). This makes it possible to incorporate the light-receiving element 370PD into the display device without significantly increasing the manufacturing process.

[0302] Of the pixel electrode 371 and the common electrode 375, 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.

[0303] The light-emitting element has at least an emissive layer 383. The light-emitting element may further have layers other than the emissive layer 383 that contain 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).

[0304] For example, a light-emitting element and a photodetector can have one or more layers from among the hole injection layer, hole transport layer, electron transport layer, and electron injection layer in common. Alternatively, one or more layers from among the hole injection layer, hole transport layer, electron transport layer, and electron injection layer can be manufactured separately for each element.

[0305] The active layer 373 contains 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 of the active layer 373. Using an organic semiconductor is preferable because it allows the light-emitting layer 383 and the active layer 373 to be formed by the same method (for example, vacuum deposition), and the manufacturing equipment can be shared.

[0306] As the material of the n-type semiconductor included in the active layer 373, electron-accepting organic semiconductor materials such as fullerenes (e.g., C 60 , or C 70 , etc.), or fullerene derivatives can be mentioned. A fullerene has a shape like a soccer ball, and this shape is energetically stable. A fullerene has both a deep (low) HOMO level and a deep (low) LUMO level. Since a fullerene has a deep LUMO level, its electron-accepting (acceptor) property is extremely high. Usually, when π-electron conjugation (resonance) spreads over a plane like benzene, the electron-donating (donor) property increases, but since a fullerene has a spherical shape, despite the large spread of π electrons, its electron-accepting property increases. A high electron-accepting property is beneficial for a light-receiving element because it causes charge separation to occur efficiently at high speed. Both C 60 , and C 70 have a broad absorption band in the visible light region. In particular, C 70 is preferable because it has a larger π-electron conjugation system and a broader absorption band in the long wavelength region compared to C 60 . In addition, examples of fullerene derivatives include [6,6]-Phenyl-C71-butyric acid methyl ester (abbreviation: PC70BM), [6,6]-Phenyl-C61-butyric acid methyl ester (abbreviation: PC60BM), or 1’,1’’,4’,4’’-Tetrahydro-di[1,4]methanonaphthaleno[1,2:2’,3’,56,60:2’’,3’’][5,6]fullerene-C60 (abbreviation: ICBA), etc.

[0307] 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, or quinone derivatives.

[0308] Examples of p-type semiconductor materials for the active layer 373 include electron-donating organic semiconductor materials such as copper(II) phthalocyanine (CuPc), tetraphenyldibenzoperiflanthene (DBP), zinc phthalocyanine (ZnPc), tin phthalocyanine (SnPc), or quinacridone.

[0309] Furthermore, examples of p-type semiconductor materials include carbazole derivatives, thiophene derivatives, furan derivatives, or 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, polyphenylenevinylene derivatives, polyparaphenylene derivatives, polyfluorene derivatives, polyvinylcarbazole derivatives, or polythiophene derivatives.

[0310] 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.

[0311] 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.

[0312] For example, the active layer 373 is preferably formed by co-depositing an n-type semiconductor and a p-type semiconductor. Alternatively, the active layer 373 may be formed by stacking an n-type semiconductor and a p-type semiconductor.

[0313] 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.

[0314] 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. In addition, inorganic compounds such as zinc oxide (ZnO) can be used as electron transport materials.

[0315] Furthermore, the active layer 373 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 the acceptor material in PBDB-T or a PBDB-T derivative can be used.

[0316] Furthermore, the active layer 373 may contain a mixture of three or more materials. For example, to broaden 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.

[0317] The display device 380B shown in Figure 21B differs from the display device 380A in that the light-receiving element 370PD and the light-emitting element 370R have the same configuration.

[0318] The light-receiving element 370PD and the light-emitting element 370R both share an active layer 373 and a light-emitting layer 383R.

[0319] Here, it is preferable that the light-receiving element 370PD has a common configuration with the light-emitting element that emits light with a longer wavelength than the light to be detected. For example, the light-receiving element 370PD configured to detect blue light can have the same configuration as one or both of the light-emitting elements 370R and 370G. For example, the light-receiving element 370PD configured to detect green light can have the same configuration as the light-emitting element 370R.

[0320] By using a common configuration for the light-receiving element 370PD and the light-emitting element 370R, the number of film deposition steps and masks can be reduced compared to a configuration where the light-receiving element 370PD and the light-emitting element 370R have distinct layers. Therefore, the manufacturing process and cost of the display device can be reduced.

[0321] Furthermore, by using a common configuration for the light-receiving element 370PD and the light-emitting element 370R, the margin for misalignment can be narrowed compared to a configuration where the light-receiving element 370PD and the light-emitting element 370R have distinct layers. This allows for an increase in the aperture ratio of the pixels, thereby improving the light extraction efficiency of the display device. This extends the lifespan of the light-emitting element. In addition, the display device can display high brightness. Furthermore, it is possible to increase the resolution of the display device.

[0322] The light-emitting layer 383R has a light-emitting material that emits red light. The active layer 373 has an organic compound that absorbs light with a shorter wavelength than red (for example, green light and / or blue light). Preferably, the active layer 373 has an organic compound that does not easily absorb red light and absorbs light with a shorter wavelength than red. As a result, red light is efficiently extracted from the light-emitting element 370R, and the photodetector 370PD can detect light with a shorter wavelength than red with high accuracy.

[0323] Furthermore, although the display device 380B shows an example in which the light-emitting element 370R and the light-receiving element 370PD have the same configuration, the light-emitting element 370R and the light-receiving element 370PD may each have optical adjustment layers of different thicknesses.

[0324] The display device 380C shown in Figures 22A and 22B has a light-receiving element 370SR, an element 370G, and an element 370B that emit red (R) light and have a light-receiving function. The configuration of the element 370G and the element 370B can be adapted from, for example, the display device 380A.

[0325] The light-receiving element 370SR has a pixel electrode 371, a hole injection layer 381, a hole transport layer 382, ​​an active layer 373, a light-emitting layer 383R, an electron transport layer 384, an electron injection layer 385, and a common electrode 375 stacked in this order. The light-receiving element 370SR has the same configuration as the light-receiving element 370R and the light-receiving element 370PD exemplified in the display device 380B described above.

[0326] Figure 22A shows the case where the light-emitting element 370SR functions as a light-emitting element. In Figure 22A, an example is shown where the light-emitting element 370B emits blue light, the light-emitting element 370G emits green light, and the light-emitting element 370SR emits red light.

[0327] Figure 22B shows the case where the light-receiving element 370SR functions as a light-receiving element. Figure 22B shows an example in which the light-receiving element 370SR receives blue light emitted by the light-emitting element 370B and green light emitted by the light-emitting element 370G.

[0328] The light-emitting element 370B, the light-emitting element 370G, and the light-receiving element 370SR each have a pixel electrode 371 and a common electrode 375, respectively. In this embodiment, the case in which the pixel electrode 371 functions as an anode and the common electrode 375 functions as a cathode will be described as an example. The light-receiving element 370SR can detect light incident on it, generate an electric charge, and extract it as an electric current by driving it with a reverse bias applied between the pixel electrode 371 and the common electrode 375.

[0329] The light-receiving element 370SR can be described as a light-emitting element with an active layer 373 added. In other words, by simply adding a step of depositing the active layer 373 to the manufacturing process of the light-emitting element, the light-receiving element 370SR can be formed in parallel with the formation of the light-emitting element. Furthermore, the light-emitting element and the light-receiving element can be formed on the same substrate. Therefore, without significantly increasing the manufacturing process, it is possible to provide the display unit with either or both imaging and sensing functions.

[0330] The stacking order of the light-emitting layer 383R and the active layer 373 is not limited. Figures 22A and 22B show an example in which the active layer 373 is provided on the hole transport layer 382 and the light-emitting layer 383R is provided on the active layer 373. The stacking order of the light-emitting layer 383R and the active layer 373 may be reversed.

[0331] Furthermore, the light-emitting / receiving device does not necessarily have to have at least one of the hole injection layer 381, hole transport layer 382, ​​electron transport layer 384, and electron injection layer 385. The light-emitting / receiving device may also have other functional layers, such as a hole blocking layer and an electron blocking layer.

[0332] In a light-receiving and light-emitting device, it is preferable to use a conductive film that transmits visible light on the electrode that extracts light, and to use a conductive film that reflects visible light on the electrode that does not extract light.

[0333] The functions and materials of each layer constituting the light-emitting and light-receiving elements are the same as those of each layer constituting the light-emitting and light-receiving elements, so a detailed explanation is omitted.

[0334] Figures 22C to 22G show examples of stacked structures of light-emitting and receiving devices.

[0335] The light-emitting and receiving device shown in Figure 22C includes a first electrode 377, a hole injection layer 381, a hole transport layer 382, ​​a light-emitting layer 383R, an active layer 373, an electron transport layer 384, an electron injection layer 385, and a second electrode 378.

[0336] Figure 22C shows an example in which a light-emitting layer 383R is provided on a hole transport layer 382, ​​and an active layer 373 is laminated on the light-emitting layer 383R.

[0337] As shown in Figures 22A to 22C, the active layer 373 and the light-emitting layer 383R may be in contact with each other.

[0338] Furthermore, it is preferable to provide a buffer layer between the active layer 373 and the light-emitting layer 383R. In this case, it is preferable that the buffer layer has hole transport and electron transport properties. For example, it is preferable to use a bipolar material for the buffer layer. Alternatively, at least one layer from among a hole injection layer, a hole transport layer, an electron transport layer, an electron injection layer, a hole blocking layer, and an electron blocking layer can be used as the buffer layer. Figure 22D shows an example in which a hole transport layer 382 is used as the buffer layer.

[0339] By providing a buffer layer between the active layer 373 and the light-emitting layer 383R, the transfer of excitation energy from the light-emitting layer 383R to the active layer 373 can be suppressed. Furthermore, the buffer layer can be used to adjust the optical path length (cavity length) of the microcavity structure. Therefore, a light-emitting / receiving device having a buffer layer between the active layer 373 and the light-emitting layer 383R can achieve high luminescence efficiency.

[0340] Figure 22E shows an example of a laminated structure in which a hole transport layer 382-1, an active layer 373, a hole transport layer 382-2, and an emissive layer 383R are stacked in that order on a hole injection layer 381. The hole transport layer 382-2 functions as a buffer layer. The hole transport layers 382-1 and 281-2 may contain the same material or different materials. Alternatively, a layer that can be used as a buffer layer as described above may be used instead of the hole transport layer 281-2. Furthermore, the positions of the active layer 373 and the emissive layer 383R may be swapped.

[0341] The light-receiving element shown in Figure 22F differs from the light-receiving element shown in Figure 22A in that it does not have a hole transport layer 382. Thus, the light-receiving element does not need to have at least one of the hole injection layer 381, hole transport layer 382, ​​electron transport layer 384, and electron injection layer 385. Furthermore, the light-receiving element may have other functional layers such as a hole blocking layer and an electron blocking layer.

[0342] The light-receiving element shown in Figure 22G differs from the light-receiving element shown in Figure 22A in that it does not have an active layer 373 and an emitting layer 383R, but has a layer 389 that serves as both an emitting layer and an active layer.

[0343] As a layer that serves as both an emissive layer and an active layer, for example, a layer can be used that contains three materials: an n-type semiconductor that can be used in the active layer 373, a p-type semiconductor that can be used in the active layer 373, and an emissive material that can be used in the emissive layer 383R.

[0344] Furthermore, it is preferable that the lowest energy absorption band of the absorption spectrum of the mixed material of n-type and p-type semiconductors and the maximum peak of the emission spectrum (PL spectrum) of the luminescent material do not overlap, and it is even more preferable that they are sufficiently far apart.

[0345] The configuration examples illustrated in this embodiment, and the corresponding drawings, etc., can be appropriately combined with other configuration examples or drawings, etc., at least in part.

[0346] This embodiment can be implemented in appropriate combination with other embodiments described herein, at least in part.

[0347] (Embodiment 5) This embodiment describes metal oxides that can be used in the OS transistor described in the above embodiment.

[0348] The metal oxide preferably contains at least indium or zinc. It is particularly preferable that it contains indium and zinc. In addition, it is preferable that it contains aluminum, gallium, yttrium, or tin. It may also contain one or more selected from boron, silicon, titanium, iron, nickel, germanium, zirconium, molybdenum, lanthanum, cerium, neodymium, hafnium, tantalum, tungsten, magnesium, cobalt, etc.

[0349] Furthermore, metal oxides can be formed by sputtering, CVD methods such as MOCVD, or ALD.

[0350] <Classification of crystal structures> Examples of crystalline structures for oxide semiconductors include amorphous (including completely amorphous), CAAC (c-axis-aligned crystalline), nc (nanocrystalline), CAC (cloud-aligned composite), single crystal, and polycrystal.

[0351] The crystal structure of a film or substrate can be evaluated using X-ray diffraction (XRD) spectroscopy. For example, it can be evaluated using the XRD spectrum obtained by GIXD (Grazing-Incidence XRD) measurement. The GIXD method is also known as the thin-film method or the Seemann-Bohlin method.

[0352] For example, in a quartz glass substrate, the peak shape of the XRD spectrum is nearly symmetrical. On the other hand, in an IGZO film with a crystalline structure, the peak shape of the XRD spectrum is asymmetrical. The asymmetrical shape of the XRD spectrum peak clearly indicates the presence of crystals in the film or substrate. In other words, if the peak shape of the XRD spectrum is not symmetrical, the film or substrate cannot be said to be in an amorphous state.

[0353] Furthermore, the crystalline structure of a film or substrate can be evaluated by the diffraction pattern (also called the nano-beam electron diffraction pattern) observed using nano-beam electron diffraction (NBED). For example, a halo is observed in the diffraction pattern of a quartz glass substrate, confirming that the quartz glass is in an amorphous state. In contrast, a spot-like pattern is observed in the diffraction pattern of an IGZO film deposited at room temperature, rather than a halo. Therefore, it is presumed that an IGZO film deposited at room temperature is in an intermediate state, neither crystalline nor amorphous, and cannot be concluded to be in an amorphous state.

[0354] <<Oxide semiconductor structure>> It should be noted that oxide semiconductors may be classified differently from those described above when considering their structure. For example, oxide semiconductors can be divided into single-crystal oxide semiconductors and other non-single-crystal oxide semiconductors. Examples of non-single-crystal oxide semiconductors include the aforementioned CAAC-OS and nc-OS. Furthermore, non-single-crystal oxide semiconductors include polycrystalline oxide semiconductors, pseudo-amorphous oxide semiconductors (a-like OS: amorphous-like oxide semiconductors), and amorphous oxide semiconductors.

[0355] Here, we will explain the details of the CAAC-OS, nc-OS, and a-like OS mentioned above.

[0356] [CAAC-OS] CAAC-OS is an oxide semiconductor having multiple crystalline regions, the c-axis of which is oriented in a specific direction. This specific direction is the thickness direction of the CAAC-OS film, the normal direction to the surface on which the CAAC-OS film is formed, or the normal direction to the surface of the CAAC-OS film. A crystalline region is a region with periodic atomic arrangement. If we consider the atomic arrangement as a lattice arrangement, then a crystalline region is also a region with a aligned lattice arrangement. Furthermore, CAAC-OS has regions where multiple crystalline regions are connected in the ab-plane direction, and these regions may exhibit distortion. Distortion refers to a point in the connected region where the orientation of the lattice arrangement changes between a region with a aligned lattice arrangement and another region with a aligned lattice arrangement. In short, CAAC-OS is an oxide semiconductor that is c-axis oriented and does not exhibit clear orientation in the ab-plane direction.

[0357] Each of the above-mentioned crystalline regions is composed of one or more minute crystals (crystals with a maximum diameter of less than 10 nm). When a crystalline region is composed of one minute crystal, the maximum diameter of that crystalline region will be less than 10 nm. When a crystalline region is composed of many minute crystals, the size of that crystalline region may be around several tens of nanometers.

[0358] Furthermore, in In-M-Zn oxides (where element M is one or more elements selected from aluminum, gallium, yttrium, tin, titanium, etc.), CAAC-OS tends to have a layered crystalline structure (also called a layered structure) consisting of layers containing indium (In) and oxygen (hereinafter referred to as the In layer) and layers containing element M, zinc (Zn), and oxygen (hereinafter referred to as the (M,Zn) layer). Note that indium and element M are mutually substitutable. Therefore, the (M,Zn) layer may contain indium. Also, the In layer may contain element M. Also, the In layer may contain Zn. This layered structure can be observed, for example, as a lattice image in high-resolution TEM (Transmission Electron Microscope) images.

[0359] When structural analysis of a CAAC-OS film is performed using, for example, an XRD instrument, out-of-plane XRD measurements using θ / 2θ scanning show a peak indicating c-axis orientation at 2θ = 31° or nearby. Note that the position of the peak indicating c-axis orientation (value of 2θ) may vary depending on the type or composition of the metal elements constituting the CAAC-OS.

[0360] Furthermore, for example, multiple bright spots are observed in the electron diffraction pattern of a CAAC-OS film. These spots are observed at point-symmetric positions with respect to the incident electron beam spot (also called the direct spot) that passed through the sample.

[0361] When the crystal region is observed from the specific direction described above, the lattice arrangement within that crystal region is based on a hexagonal lattice, but the unit cell is not necessarily a regular hexagon and may be non-regular hexagonal. Furthermore, the strain may have a pentagonal or heptagonal lattice arrangement. Moreover, in CAAC-OS, clear grain boundaries cannot be observed even near the strain. In other words, it can be seen that the formation of grain boundaries is suppressed by the strain in the lattice arrangement. This is thought to be because CAAC-OS can tolerate strain due to the sparse arrangement of oxygen atoms in the ab-plane direction, or because the bond distance between atoms changes due to the substitution of metal atoms.

[0362] A crystal structure in which clear grain boundaries are observed is called a polycrystal. Grain boundaries act as recombination centers, trapping carriers and potentially causing a decrease in the transistor's on-current or field-effect mobility. Therefore, CAAC-OS, in which clear grain boundaries are not observed, is one of the crystalline oxides with a suitable crystal structure for the semiconductor layer of a transistor. In addition, a structure containing Zn is preferred for the composition of CAAC-OS. For example, In-Zn oxide and In-Ga-Zn oxide are preferred because they suppress the generation of grain boundaries more effectively than In oxide.

[0363] CAAC-OS is an oxide semiconductor with high crystallinity and no clearly defined grain boundaries. Therefore, CAAC-OS is less susceptible to the decrease in electron mobility caused by grain boundaries. Furthermore, since the crystallinity of oxide semiconductors can decrease due to the inclusion of impurities and the generation of defects, CAAC-OS can be said to be an oxide semiconductor with few impurities and defects (such as oxygen vacancies). Consequently, oxide semiconductors containing CAAC-OS have stable physical properties. Therefore, oxide semiconductors containing CAAC-OS are heat-resistant and highly reliable. In addition, CAAC-OS is stable even at high temperatures (so-called thermal budget) during the manufacturing process. Therefore, using CAAC-OS in OS transistors allows for greater flexibility in the manufacturing process.

[0364] [nc-OS] nc-OS exhibits periodicity in atomic arrangement in minute regions (e.g., regions between 1 nm and 10 nm, particularly between 1 nm and 3 nm). In other words, nc-OS contains minute crystals. These minute crystals are also called nanocrystals because their size is, for example, between 1 nm and 10 nm, particularly between 1 nm and 3 nm. Furthermore, nc-OS shows no regularity in crystal orientation between different nanocrystals. Therefore, no orientation is observed throughout the film. Consequently, depending on the analytical method, nc-OS may be indistinguishable from a-like OS or amorphous oxide semiconductors. For example, when structural analysis of an nc-OS film is performed using an XRD instrument, no peaks indicating crystallinity are detected in out-of-plane XRD measurements using θ / 2θ scanning. Also, when electron diffraction (also called limited-field electron diffraction) is performed on an nc-OS film using an electron beam with a probe diameter larger than that of the nanocrystals (e.g., 50 nm or more), a diffraction pattern resembling a halo pattern is observed. On the other hand, when electron diffraction (also called nanobeam electron diffraction) is performed on an nc-OS film using an electron beam with a probe diameter close to or smaller than the size of the nanocrystal (for example, 1 nm to 30 nm), an electron diffraction pattern may be obtained in which multiple spots are observed within a ring-shaped region centered on a direct spot.

[0365] [a-like OS] a-like OS is an oxide semiconductor having a structure between nc-OS and amorphous oxide semiconductors. a-like OS has porous or low-density regions. That is, a-like OS has lower crystallinity compared to nc-OS and CAAC-OS. Also, a-like OS has a higher hydrogen concentration in the film compared to nc-OS and CAAC-OS.

[0366] <<Oxide Semiconductor Composition>> Next, we will explain the details of CAC-OS mentioned above. Note that CAC-OS refers to the material composition.

[0367] [CAC-OS] CAC-OS is a material composition in which, for example, the elements constituting the metal oxide are unevenly distributed in sizes of 0.5 nm to 10 nm, preferably 1 nm to 3 nm, or close to that size. In the following, a state in which one or more metal elements are unevenly distributed in a metal oxide, and the regions containing the metal elements are mixed in sizes of 0.5 nm to 10 nm, preferably 1 nm to 3 nm, or close to that size, is also referred to as a mosaic or patchy state.

[0368] Furthermore, CAC-OS is a composite metal oxide having a mosaic-like structure formed by the separation of the material into a first region and a second region, with the first region distributed within the film (hereinafter also referred to as a cloud-like structure). In other words, CAC-OS is a composite metal oxide having a structure in which the first region and the second region are mixed.

[0369] Here, the atomic ratios of In, Ga, and Zn to the metal elements constituting the CAC-OS in In-Ga-Zn oxide are denoted as [In], [Ga], and [Zn], respectively. For example, in the CAC-OS of In-Ga-Zn oxide, the first region is the region where [In] is greater than the [In] in the composition of the CAC-OS film. The second region is the region where [Ga] is greater than the [Ga] in the composition of the CAC-OS film. Alternatively, for example, the first region is the region where [In] is greater than the [In] in the second region, and [Ga] is smaller than the [Ga] in the second region. The second region is the region where [Ga] is greater than the [Ga] in the first region, and [In] is smaller than the [In] in the first region.

[0370] Specifically, the first region described above is a region whose main components are indium oxide and indium zinc oxide, etc. The second region described above is a region whose main components are gallium oxide and gallium zinc oxide, etc. In other words, the first region can be rephrased as a region whose main component is In. Similarly, the second region can be rephrased as a region whose main component is Ga.

[0371] Furthermore, a clear boundary may not be observed between the first region and the second region described above.

[0372] Furthermore, CAC-OS in In-Ga-Zn oxide refers to a material composition containing In, Ga, Zn, and O, in which regions with Ga as the main component and regions with In as the main component are arranged in a mosaic-like manner, with these regions existing randomly. Therefore, it is presumed that CAC-OS has a structure in which metal elements are unevenly distributed.

[0373] CAC-OS can be formed by sputtering, for example, under conditions where the substrate is not intentionally heated. When forming CAC-OS by sputtering, one or more gases selected from inert gases (typically argon), oxygen gas, and nitrogen gas may be used as the deposition gas. Furthermore, a lower ratio of the oxygen gas flow rate to the total deposition gas flow rate during deposition is preferable. For example, it is preferable that the oxygen gas flow rate ratio to the total deposition gas flow rate during deposition be 0% or more and less than 30%, preferably 0% or more and 10% or less.

[0374] Furthermore, for example, in the case of CAC-OS in In-Ga-Zn oxide, EDX mapping obtained using energy dispersive X-ray spectroscopy (EDX) confirms that it has a structure in which regions mainly composed of In (first region) and regions mainly composed of Ga (second region) are unevenly distributed and mixed.

[0375] Here, the first region is a region with higher conductivity compared to the second region. In other words, the conductivity of the metal oxide is exhibited when carriers flow through the first region. Therefore, a high field-effect mobility (μ) can be achieved when the first region is distributed in a cloud-like manner within the metal oxide.

[0376] On the other hand, the second region is a region with higher insulating properties compared to the first region. In other words, the distribution of the second region within the metal oxide can suppress leakage current.

[0377] Therefore, when CAC-OS is used in a transistor, the conductivity due to the first region and the insulation due to the second region work complementaryly to give CAC-OS a switching function (on / off function). In other words, CAC-OS has conductive function in part of the material, insulating function in part of the material, and semiconductor function as a whole. By separating the conductive function and the insulating function, both functions can be maximized. Therefore, by using CAC-OS in a transistor, a high on-current (I on ), high field-effect mobility (μ), and good switching operation can be achieved.

[0378] Furthermore, transistors using CAC-OS offer high reliability. Therefore, CAC-OS is ideal for various semiconductor devices, including display devices.

[0379] Oxide semiconductors can take on diverse structures, each possessing different properties. One embodiment of the present invention may include two or more of the following: amorphous oxide semiconductors, polycrystalline oxide semiconductors, a-like OS, CAC-OS, nc-OS, and CAAC-OS.

[0380] <Transistors containing oxide semiconductors> Next, we will explain the case where the above oxide semiconductor is used in a transistor.

[0381] By using the above-mentioned oxide semiconductor in transistors, it is possible to realize transistors with high field-effect mobility. Furthermore, it is possible to realize highly reliable transistors.

[0382] It is preferable to use an oxide semiconductor with a low carrier concentration for the transistor. For example, the carrier concentration of an oxide semiconductor is 1 × 10⁻⁶. 17 cm -3 The following is preferably 1 × 10 15 cm -3 More preferably 1 × 10 13 cm -3More preferably 1 × 10 11 cm -3 More preferably 1 × 10 10 cm -3 It is less than 1 × 10 -9 cm -3 This concludes the explanation. Furthermore, when lowering the carrier concentration of an oxide semiconductor film, the impurity concentration in the oxide semiconductor film should be lowered to reduce the defect level density. In this specification, a low impurity concentration and low defect level density are referred to as high-purity intrinsic or substantially high-purity intrinsic. Note that oxide semiconductors with low carrier concentrations are sometimes referred to as high-purity intrinsic or substantially high-purity intrinsic oxide semiconductors.

[0383] Furthermore, oxide semiconductor films that are highly pure or substantially highly pure have a low defect level density, which may result in a low trap level density.

[0384] Furthermore, charges trapped in the trap levels of oxide semiconductors can take a long time to disappear, sometimes behaving like fixed charges. Therefore, transistors in which channel formation regions are formed in oxide semiconductors with a high trap level density may exhibit unstable electrical properties.

[0385] Therefore, reducing the impurity concentration in the oxide semiconductor is effective in stabilizing the electrical characteristics of the transistor. Furthermore, in order to reduce the impurity concentration in the oxide semiconductor, it is preferable to also reduce the impurity concentration in adjacent films. Examples of impurities include hydrogen, nitrogen, alkali metals, alkaline earth metals, iron, nickel, or silicon.

[0386] <Impurities> Here, we will explain the effects of various impurities in oxide semiconductors.

[0387] In oxide semiconductors, the presence of silicon or carbon, which are Group 14 elements, leads to the formation of defect levels in the oxide semiconductor. Therefore, the concentration of silicon or carbon in the oxide semiconductor and the concentration of silicon or carbon near the interface with the oxide semiconductor (concentration obtained by secondary ion mass spectrometry (SIMS)) are compared by 2 × 10⁻⁶. 18 atoms / cm 3 The following is preferably 2 × 10 17 atoms / cm 3 The following applies:

[0388] Furthermore, if an oxide semiconductor contains alkali metals or alkaline earth metals, it may form defect levels and generate carriers. Therefore, transistors using oxide semiconductors containing alkali metals or alkaline earth metals tend to exhibit normally-on characteristics. For this reason, the concentration of alkali metals or alkaline earth metals in the oxide semiconductor obtained by SIMS should be set to 1 × 10⁻⁶. 18 atoms / cm 3 The following is preferably 2 × 10 16 atoms / cm 3 Do the following:

[0389] Furthermore, in oxide semiconductors, the presence of nitrogen generates electrons, which act as carriers, increasing the carrier concentration and making it easier for the semiconductor to become n-type. As a result, transistors using oxide semiconductors containing nitrogen tend to exhibit normally-on characteristics. Alternatively, the presence of nitrogen in oxide semiconductors can lead to the formation of trap levels. As a result, the electrical properties of the transistor may become unstable. For this reason, the nitrogen concentration in oxide semiconductors obtained by SIMS should be set to 5 × 10⁻⁶. 19 atoms / cm 3 Less than 5 × 10 18 atoms / cm 3 More preferably 1 × 10 18 atoms / cm 3 More preferably 5 × 10 17 atoms / cm 3 Do the following:

[0390] Furthermore, hydrogen contained in oxide semiconductors can react with oxygen bonded to metal atoms to form water, potentially creating oxygen vacancies. Hydrogen can then fill these vacancies, generating electrons, which act as carriers. Additionally, some of the hydrogen can combine with oxygen bonded to metal atoms to generate electrons. Therefore, transistors using oxide semiconductors containing hydrogen tend to exhibit normally-on characteristics. For this reason, it is preferable to reduce the hydrogen content in oxide semiconductors as much as possible. Specifically, in oxide semiconductors, the hydrogen concentration obtained by SIMS should be 1 × 10⁻⁶. 20 atoms / cm 3 Less than 1 × 10 19 atoms / cm 3 Less than 5x10 18 atoms / cm 3 Less than 1 × 10 18 atoms / cm 3 Make it less than.

[0391] By using an oxide semiconductor with sufficiently reduced impurities in the channel formation region of a transistor, stable electrical characteristics can be imparted.

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

[0393] (Embodiment 6) This embodiment describes an electronic device having a display device according to one aspect of the present invention.

[0394] A display device according to one aspect of the present invention can be installed in various electronic devices. For example, in addition to electronic devices with relatively large screens such as television sets, desktop or notebook computers, tablet computers, computer monitors, digital signage, and large game machines such as pachinko machines, a display device according to one aspect of the present invention can be installed in digital cameras, digital video cameras, digital photo frames, portable game consoles, portable information terminals, and sound playback devices. An example of the configuration of an electronic device that can be equipped with a display device according to one aspect of the present invention will be explained with reference to Figures 23A to 23E.

[0395] Figure 23A shows an example of an oxygen concentration meter 900. The oxygen concentration meter 900 has a housing 911 and a light-receiving device 912. The housing 911 is provided with a cavity, and the light-receiving device 912 is provided so as to be in contact with the wall surface of the cavity.

[0396] The light-emitting and receiving device 912 has the function of both a light source that emits light and a sensor that detects light. For example, when an object is placed in the cavity of the housing 911, the light-emitting and receiving device 912 emits light, which is irradiated onto the object, and the light-emitting and receiving device 912 can detect the light reflected from the object.

[0397] For example, when a finger is placed in the cavity of the housing 911, the color of the blood changes depending on the oxygen saturation of the hemoglobin in the blood (the percentage of hemoglobin bound to oxygen). This changes the intensity of the reflected light from the finger detected by the light-receiving device 912. For example, the intensity of the red light detected by the light-receiving device 912 changes. Thus, the oxygen concentration meter 900 can measure oxygen saturation by detecting the intensity of the reflected light with the light-receiving device 912. The oxygen concentration meter 900 can be, for example, a pulse oximeter.

[0398] A display device according to one embodiment of the present invention can be applied to the light-receiving device 912. In this case, the light-receiving device 912 has at least a light-emitting element that emits red light (R). Preferably, the light-receiving device 912 also has a light-emitting element that emits infrared light (IR). The red light (R) reflectance of hemoglobin bound to oxygen is significantly different from that of hemoglobin not bound to oxygen. On the other hand, the difference between the infrared light (IR) reflectance of hemoglobin bound to oxygen and that of hemoglobin not bound to oxygen is small. Therefore, by having a light-receiving device 912 that emits not only red light (R) but also infrared light (IR), the oxygen concentration meter 900 can measure oxygen saturation with high accuracy.

[0399] When applying a display device according to one embodiment of the present invention as the light-receiving device 912, it is preferable that the light-receiving device 912 is flexible. The flexibility of the light-receiving device 912 allows it to have a curved shape. This enables, for example, uniform irradiation of light onto a finger, and enables, for example, high-precision measurement of oxygen saturation.

[0400] Figure 23B shows an example of a portable data terminal 9100. The portable data terminal 9100 includes a display unit 9110, a housing 9101, keys 9102, and a speaker 9103, etc. The portable data terminal 9100 can be, for example, a tablet. Here, keys such as key 9102 can be, for example, keys for switching the power on and off. In other words, keys such as key 9102 can be, for example, power switches. Also, keys such as key 9102 can be, for example, operation keys used to make an electronic device perform a desired operation.

[0401] The display unit 9110 can display information 9104, operation buttons (also called operation icons, or simply icons) 9105, etc.

[0402] By providing a display device according to one aspect of the present invention to the portable data terminal 9100, the display unit 9110 can function as a touch sensor or a near-touch sensor.

[0403] Figure 23C shows an example of the digital signage 9200. The digital signage 9200 can be configured such that a display unit 9210 is attached to a column 9201.

[0404] By providing the digital signage 9200 with a display device according to one aspect of the present invention, the display unit 9210 can function as a touch sensor or a near-touch sensor.

[0405] Figure 23D shows an example of a personal digital information terminal (PDI) 9300. The PDI 9300 includes a display unit 9310, a housing 9301, a speaker 9302, a camera 9303, a key 9304, a connection terminal 9305, and a connection terminal 9306, etc. The PDI 9300 can be, for example, a smartphone. The connection terminal 9305 can be, for example, a microUSB, Lightning, or Type-C. The connection terminal 9306 can be, for example, an earphone jack.

[0406] The display unit 9310 can display, for example, the operation buttons 9307. The display unit 9310 can also display information 9308. Examples of information 9308 include notifications for incoming emails, SNS (Social Networking Service) messages, or phone calls, the subject of the email or SNS message, the sender's name, date and time, battery level, signal strength, etc.

[0407] By providing a display device according to one aspect of the present invention to the portable information terminal 9300, the display unit 9310 can function as a touch sensor or a near-touch sensor.

[0408] Figure 23E shows an example of a wristwatch-type personal information terminal 9400. The personal information terminal 9400 includes a display unit 9410, a housing 9401, a wristband 9402, a key 9403, and a connection terminal 9404, etc. The connection terminal 9404 can be, for example, a microUSB, Lightning, or Type-C, similar to the connection terminal 9305, etc.

[0409] The display unit 9410 can display information 9406 and operation buttons 9407, etc. Figure 23E shows an example in which the time is displayed on the display unit 9410 as information 9406.

[0410] By providing a display device according to one aspect of the present invention to the portable information terminal 9400, the display unit 9410 can function as a touch sensor or a near-touch sensor.

[0411] The configuration examples illustrated in this embodiment, and the corresponding drawings, etc., can be appropriately combined with other configuration examples or drawings, etc., at least in part.

[0412] This embodiment can be implemented in appropriate combination with other embodiments described herein, at least in part. [Explanation of symbols]

[0413] 10: Display device, 10A: Display device, 10B: Display device, 20: Pixel, 51: Substrate, 52: Finger, 53: Layer, 55: Layer, 57: Layer, 59: Substrate, 65: Area, 67: Fingerprint, 69: Contact area, 71: Layer, 73: Light-shielding layer, 75: Light, 77: Light, 80: Light-receiving area, 81: Light-receiving area, 100: Display device, 100A: Display device, 100B: Display device, 100C: Display device, 100D: Display device, 100E: Display device, 101: Substrate, 110: Light-emitting element, 110B: Light-emitting element, 110G: Light-emitting element, 110IR: Light-emitting element, 110R: Light-emitting element, 111: Pixel electrode, 111 B: Pixel electrode, 111C: Connecting electrode, 111G: Pixel electrode, 111IR: Pixel electrode, 111PD: Pixel electrode, 111R: Pixel electrode, 113: Hole injection layer, 113B: Hole injection layer, 113G: Hole injection layer, 113Gf: Functional film, 113IR: Hole injection layer, 113R: Hole injection layer, 113Rf: Functional film, 115: Hole transport layer, 115B: Hole transport layer, 115G: Hole transport layer, 115Gf: Functional film, 115IR: Hole transport layer, 115PD: Hole transport layer, 115R: Hole transport layer, 115Rf: Functional film, 117: Emitting layer, 117B: Emitting layer, 117G: Emitting layer, 117 Gf: Emitting film, 117IR: Emitting layer, 117R: Emitting layer, 117Rf: Emitting film, 119: Electron transport layer, 119B: Electron transport layer, 119G: Electron transport layer, 119Gf: Functional film, 119IR: Electron transport layer, 119PD: Electron transport layer, 119R: Electron transport layer, 119Rf: Functional film, 121: Common layer, 123: Common electrode, 125: Protective layer, 127: Void, 130: Connection part, 131: Insulating layer, 141: Transistor, 141a: Sacrificial film, 141b: Sacrificial film, 142: Transistor, 143: Space, 143a: Protective film, 143b: Protective film, 145a: Resist mask, 1 45b: Resist mask, 146: Filter, 147a: Sacrificial layer, 147b: Sacrificial layer, 147c: Sacrificial layer, 147d: Sacrificial layer, 148: Light-shielding layer, 149a: Protective layer, 149b: Protective layer, 150: Photodetector, 150L: Photodetector, 151: Substrate, 152: Substrate, 153: Substrate, 154: Substrate, 155: Adhesive layer, 156: Adhesive layer, 157: Photodetector layer, 158: Insulating layer, 162: Display unit, 164: Circuit, 165: Wiring, 166: Conductive layer, 172: FPC, 173: IC, 201: Transistor, 204: Connection unit, 211: Insulating layer, 212: Insulating layer, 213: Insulating layer,214: insulating layer, 215: insulating layer, 221: conductive layer, 222a: conductive layer, 222b: conductive layer, 223: conductive layer, 228: region, 231: semiconductor layer, 240: capacitance, 241: conductive layer, 242: adhesive layer, 243: insulating layer, 244: connection layer, 245: conductive layer, 251: conductive layer, 252: conductive layer, 254: insulating layer, 255: insulating layer, 256: plug, 261: insulating layer, 262: insulating layer, 263: insulating layer, 264: insulating layer, 265: insulating layer, 271: plug, 274: plug, 274a: conductive layer, 274b: conductive layer, 281-2: hole transport layer, 301: substrate, 310: Transistor, 311: Conductive layer, 312: Low resistance region, 313: Insulating layer, 314: Insulating layer, 315: Element isolation layer, 320: Transistor, 321: Semiconductor layer, 323: Insulating layer, 324: Conductive layer, 325: Conductive layer, 326: Insulating layer, 327: Conductive layer, 328: Insulating layer, 329: Insulating layer, 331: Substrate, 332: Insulating layer, 370B: Light-emitting element, 370G: Light-emitting element, 370PD: Photodetector, 370R: Light-emitting element, 370SR: Light-receiving element, 371: Pixel electrode, 373: Active layer, 375: Common electrode, 377: Electrode, 378: Electrode, 380A: Display device, 380B: Display device, 380C: Display device, 381: Hole injection layer, 382: Hole transport layer, 382-1: Hole transport layer, 382-2: Hole transport layer, 383: Light-emitting layer, 383B: Light-emitting layer, 383G: Light-emitting layer, 383R: Light-emitting layer, 384: Electron transport layer, 385: Electron injection layer, 389: Layer, 419: Resin layer, 420: Substrate, 672: Electrode, 686: EL layer, 686a: EL layer, 686b: EL layer, 688: Electrode, 900: Oxygen concentration meter, 911: Housing, 912: Light-receiving device, 4411: Light-emitting layer, 4412: Light-emitting layer, 4413: Light-emitting layer, 4420: Layer, 4420-1: Layer, 4420- 2: Layer, 4430: Layer, 4430-1: Layer, 4430-2: Layer, 9100: Mobile data terminal, 9101: Enclosure, 9102: Key, 9103: Speaker, 9104: Information, 9110: Display unit, 9200: Digital signage, 9201: Pillar, 9210: Display unit, 9300: Mobile information terminal, 9301: Enclosure, 9302: Speaker, 9303: Camera, 9304: Key, 9305: Connection terminal, 9306: Connection terminal, 9307: Operation button, 9308: Information, 9310: Display unit, 9400: Mobile information terminal, 9401: Enclosure, 9402: Wristband, 9403: Key,9404: Connection terminal, 9406: Information, 9407: Operation buttons, 9410: Display unit,

Claims

[Claim 1] A display device, The display device has one pixel, The aforementioned pixel has a light-emitting element capable of emitting red light, a light-emitting element capable of emitting green light, a light-emitting element capable of emitting blue light, a light-receiving element capable of detecting visible light and infrared light, and a light-emitting element capable of emitting infrared light. A display device comprising a light-emitting element capable of emitting red light, a light-emitting element capable of emitting green light, a light-emitting element capable of emitting blue light, a light-receiving element capable of detecting visible light and infrared light, and a light-emitting element capable of emitting infrared light, all of which are formed on a first substrate.

Images