Display device and method for manufacturing a display device

Abstract

The present invention provides a display device with high display quality. The present invention is a display device having first pixels, second pixels adjacent to the first pixels, a first insulation layer, and a second insulation layer on the first insulation layer, wherein: the first pixels have a first pixel electrode, a first electroluminescence layer which covers the first pixel electrode, a third insulation layer on the first electroluminescence layer, and a common electrode on the first electroluminescence layer and the third insulation layer; the common electrode is in contact with other sections of the top surface of the first electroluminescence layer; the first electroluminescence layer includes an organic compound OM; the amount contained by the first electroluminescence layer of an organic compound comprising an oxide of the organic compound OM or a partial structure of the organic compound OM is more than 0 and no greater than 1 / 10 of the amount of the organic compound OM which is contained; the second pixels have a second pixel electrode, a second electroluminescence layer covering the second pixel electrode, a fourth insulation layer on the second electroluminescence layer, and a common electrode on the second electroluminescence layer and the fourth insulation layer; a part of the second insulation layer overlaps the first pixel electrode; and another part of the second insulation layer overlaps the second pixel electrode.

Description

[Technical Field]

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

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

[0003] In recent years, there has been a growing demand for higher resolution display panels. Devices requiring high-resolution display panels include smartphones, tablet devices, and notebook computers. Furthermore, stationary display devices such as television sets and monitors also require higher resolution and greater detail. Among the devices demanding the highest resolution are those used for virtual reality (VR) and augmented reality (AR).

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

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

[0006] Patent Document 2 discloses a display device for VR using an organic EL device.

Prior Art Documents

Patent Documents

[0007]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0008] One aspect of the present invention is to provide a display device with high display quality as one of the problems. One aspect of the present invention is to provide a highly reliable display device as one of the problems. One aspect of the present invention is to provide a display device that can be easily made high-definition as one of the problems. One aspect of the present invention is to provide a display device that has both high display quality and high definition as one of the problems. One aspect of the present invention is to provide a display device with low power consumption as one of the problems.

[0009] One aspect of the present invention is to provide a display device having a novel structure or a method for manufacturing a display device as one of the problems. One aspect of the present invention is to provide a method for manufacturing the above-described display device with high yield as one of the problems. One aspect of the present invention is to at least reduce at least one of the problems of the prior art as one of the problems.

[0010] Furthermore, the description of these problems does not preclude the existence of other problems. Moreover, one aspect of the present invention does not need to solve all of these problems. Other problems can be identified from the description in the specification, drawings, claims, etc. [Means for solving the problem]

[0011] One aspect of the present invention is a display device having a first pixel, a second pixel arranged adjacent to the first pixel, a first insulating layer, and a second insulating layer on the first insulating layer, wherein the first pixel has a first pixel electrode, a first EL layer covering the first pixel electrode, a third insulating layer in contact with a part of the upper surface of the first EL layer, and a common electrode on the first EL layer and the third insulating layer, the common electrode in contact with another part of the upper surface of the first EL layer, the first EL layer is sandwiched between the first pixel electrode and the common electrode, the first EL layer contains an organic compound OM, the amount of an organic compound having an oxide of the organic compound OM or a partial structure of the organic compound OM in the first EL layer is more than 0 and less than or equal to 1 / 10 of the amount of the organic compound OM, and the second pixel has a second pixel electrode and a second pixel The display device comprises a second EL layer covering the electrodes, a fourth insulating layer in contact with a portion of the upper surface of the second EL layer, and a common electrode on the second EL layer and the fourth insulating layer, wherein the first insulating layer is in contact with the upper and side surfaces of the third insulating layer, the upper and side surfaces of the fourth insulating layer, the side surfaces of the first EL layer, and the side surfaces of the second EL layer, and the first, third, and fourth insulating layers are each made of inorganic material, the second insulating layer is made of organic material, a portion of the second insulating layer overlaps with the first pixel electrode, another portion of the second insulating layer overlaps with the second pixel electrode, the second insulating layer has a tapered shape on its side surface and a convex curved shape on its upper surface in a cross-sectional view of the display device, the taper angle of the tapered shape on the side surface of the second insulating layer is less than 90°, and the common electrode overlaps the second insulating layer.

[0012] In the above, it is preferable that the first pixel electrode and the second pixel electrode each have a tapered shape on their sides in a cross-sectional view of the display device, and that the taper angle of the tapered shape on the sides of the first pixel electrode and the second pixel electrode is less than 90°.

[0013] Furthermore, it is preferable that the first insulating layer, the third insulating layer, and the fourth insulating layer contain aluminum oxide. Furthermore, it is preferable that the second insulating layer contains a photosensitive acrylic resin.

[0014] Furthermore, it is preferable that the upper surface of the first EL layer, the upper surface of the second EL layer, and the upper surface of the second insulating layer have regions that are in contact with a common electrode.

[0015] Furthermore, in the above, it is preferable that the first pixel has a common layer disposed between the first EL layer and the common electrode, the second pixel has a common layer disposed between the second EL layer and the common electrode, and the upper surface of the first EL layer, the upper surface of the second EL layer, and the upper surface of the second insulating layer have regions in contact with the common layer.

[0016] Another aspect of the present invention involves forming a first pixel electrode, a first EL layer covering the first pixel electrode, a first insulating layer in contact with the upper surface of the first EL layer, a second pixel electrode, a second EL layer covering the second pixel electrode, and a second insulating layer in contact with the upper surface of the second EL layer; forming a third insulating layer covering the first EL layer, the first insulating layer, the second EL layer, and the second insulating layer; applying a photosensitive organic resin on the third insulating layer; performing a first exposure to expose a portion of the organic resin to visible light or ultraviolet light; developing to remove a portion of the organic resin; and forming a fourth insulating layer. An edge layer is formed, and a first heat treatment is performed to tapere the side surface of the fourth insulating layer and create a convex curved surface on the upper surface of the fourth insulating layer. Parts of the first insulating layer, the second insulating layer, and the third insulating layer are removed, exposing the upper surfaces of the first EL layer and the second EL layer. A common electrode is formed by covering the first EL layer, the second EL layer, and the fourth insulating layer. Between the exposure of the upper surfaces of the first EL layer and the second EL layer and the formation of the common electrode, the amount of ultraviolet light with a wavelength of less than 400 nm that the first EL layer and the second EL layer are exposed to is 0 mJ / cm². 2 Larger, 1000 mJ / cm 2 Preferably, 700 mJ / cm² 2 More preferably, 250 mJ / cm² 2 The following is a method for manufacturing a display device that suppresses the following.

[0017] In the above, it is preferable that the first EL layer and the second EL layer are formed by photolithography, and that there is a region where the distance between the first EL layer and the second EL layer is 8 μm or less.

[0018] Furthermore, in the above, it is preferable to form an aluminum oxide film as the third insulating layer using the ALD method.

[0019] Furthermore, it is preferable that the organic resin is formed using a photosensitive acrylic resin. Furthermore, it is preferable that the viscosity of the organic resin is 1 cP or more and 1500 cP or less. Furthermore, it is preferable that a portion of the organic resin is located on a region that overlaps with the first pixel electrode or the second pixel electrode.

[0020] Furthermore, in the above, it is preferable to perform a second heat treatment before the first exposure, and to perform the second heat treatment at a temperature of 70°C to 120°C.

[0021] Furthermore, in the above, a second exposure is performed before the first heat treatment, and the second exposure is 0 mJ / cm². 2 Larger, 500 mJ / cm 2 It is preferable to irradiate with the following visible light or ultraviolet light.

[0022] Furthermore, in the above, it is preferable that the first heat treatment be carried out at a temperature of 70°C to 130°C.

[0023] Furthermore, in the above, it is preferable to perform a third heat treatment after the first heat treatment, and to perform the third heat treatment at a temperature of 80°C to 100°C. [Effects of the Invention]

[0024] According to one aspect of the present invention, a display device with high display quality can be provided. Furthermore, a highly reliable display device can be provided. Furthermore, a display device that is easily made high-resolution can be provided. Furthermore, a display device that combines high display quality and high resolution can be provided. Furthermore, a display device with low power consumption can be provided.

[0025] Furthermore, according to one aspect of the present invention, a display device having a novel configuration or a method for manufacturing a display device can be provided. Also, a method for manufacturing the above-mentioned display device with high yield can be provided. According to one aspect of the present invention, at least one of the problems of the prior art can be mitigated.

[0026] 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]

[0027] Figure 1A is a top view showing an example of a display panel. Figure 1B is a cross-sectional view showing an example of a display panel. Figures 2A and 2B are cross-sectional views showing an example of a display panel. Figures 3A to 3D are cross-sectional views showing an example of a display panel. Figure 4A is a top view showing an example of a display panel. Figure 4B is a cross-sectional view showing an example of a display panel. Figures 5A to 5C are cross-sectional views showing an example of a method for manufacturing a display panel. Figures 6A to 6C are cross-sectional views showing an example of a method for manufacturing a display panel. Figures 7A to 7C are cross-sectional views showing an example of a method for manufacturing a display panel. Figures 8A to 8C are cross-sectional views showing an example of a method for manufacturing a display panel. Figures 9A to 9C are cross-sectional views showing an example of a method for manufacturing a display panel. Figures 10A to 10F are top views showing an example of a pixel. Figures 11A to 11H are top views showing an example of a pixel. Figures 12A to 12J are top views showing examples of pixels. Figures 13A to 13D are top views showing an example of a pixel. Figures 13E to 13G are cross-sectional views showing an example of a display panel. Figures 14A and 14B are perspective views showing an example of a display panel. Figures 15A and 15B are cross-sectional views showing an example of a display panel. Figure 16 is a cross-sectional view showing an example of a display panel. Figure 17 is a cross-sectional view showing an example of a display panel. Figure 18 is a cross-sectional view showing an example of a display panel. Figure 19 is a cross-sectional view showing an example of a display panel. Figure 20 is a cross-sectional view showing an example of a display panel. Figure 21 is a perspective view showing an example of a display panel. Figure 22A is a cross-sectional view showing an example of a display panel. Figures 22B and 22C are cross-sectional views showing an example of a transistor. Figures 23A to 23D are cross-sectional views showing an example of a display panel. Figure 24 is a cross-sectional view showing an example of a display panel. Figure 25A is a block diagram showing an example of a display panel. Figures 25B to 25D show examples of pixel circuits. Figures 26A to 26D show examples of transistors. Figures 27A to 27F show examples of the configuration of a light-emitting device. Figures 28A to 28D show examples of electronic devices. Figures 29A to 29F show examples of electronic devices. Figures 30A to 30G show examples of electronic devices. Figure 31 is a diagram illustrating the configuration of a sample according to an embodiment. Figure 32 illustrates the relative photoluminescence intensity of the sample according to the example. Figure 33 illustrates the liquid chromatography-mass spectrometry results of the sample according to the example. Figure 34 illustrates the liquid chromatography-mass spectrometry results of the sample according to the example. Figure 35 shows the liquid chromatogram of comparative sample 1 related to the reference example. Figure 36 is a conceptual diagram showing the case where oxygen is bonded to the anthracene skeleton. Figure 37 illustrates the change in luminescence intensity of a sample according to the example, accompanied by exposure. Figure 38 illustrates the change in luminescence intensity during exposure for a comparative sample related to the reference example. Figures 39A and 39B illustrate the configuration of the sample according to the embodiment. Figures 40A to 40D illustrate the configuration of a sample according to an embodiment. Figure 41 illustrates the change in luminescence intensity of a sample according to the example, accompanied by exposure. Figure 42 illustrates the change in luminescence intensity of a sample according to the example, accompanied by exposure. Figure 43 illustrates the change in luminescence intensity during exposure for a comparative sample related to the reference example. Figure 44 illustrates the relative photoluminescence intensity of the samples according to the embodiment. Figure 45 illustrates the liquid chromatography-mass spectrometry results of the sample according to the example. Figure 46 illustrates the liquid chromatography-mass spectrometry results of the sample according to the example. Figure 47 illustrates the relative photoluminescence intensity of the samples according to the examples. Figure 48 illustrates the liquid chromatography-mass spectrometry results of the sample according to the example. Figure 49 illustrates the liquid chromatography-mass spectrometry results of the sample according to the example. [Modes for carrying out the invention]

[0028] 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.

[0029] In 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 same hatching pattern may be used, and reference numerals may not be assigned.

[0030] 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.

[0031] Furthermore, ordinal numbers such as "the first," "the second," etc., used in this specification are added to avoid confusion of constituent elements and do not imply any numerical limitation.

[0032] Furthermore, in this specification, the term "display device" may be read as "electronic device."

[0033] In this specification, a display panel, which is one form of a display device, has the function of displaying (outputting) images or the like on its display surface. Therefore, a display panel is one form of an output device.

[0034] Furthermore, in this specification, a display panel with a connector such as an FPC (Flexible Printed Circuit) or TCP (Tape Carrier Package) attached to the substrate, or a display panel with an IC mounted on the substrate using a COG (Chip On Glass) method, may be referred to as a display panel module, display module, or simply a display panel. Also, in this specification, a display panel module, display module, or display panel may be referred to as a display device.

[0035] 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."

[0036] 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.

[0037] 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 that do not use a metal mask or an FMM may be referred to as MML (Metal Maskless) structured devices.

[0038] In this specification, holes or electrons may be referred to as "carriers." Specifically, a hole injection layer or electron injection layer may be called a "carrier injection layer," a hole transport layer or electron transport layer may be called a "carrier transport layer," and a hole block layer or electron block layer may be called a "carrier block layer." Note that the above-mentioned carrier injection layer, carrier transport layer, and carrier block layer may not be clearly distinguishable by their cross-sectional shape or characteristics. Furthermore, a single layer may combine the functions of two or three of these layers.

[0039] (Embodiment 1) In this embodiment, a display panel according to one aspect of the present invention will be described with reference to Figures 1 to 9.

[0040] One aspect of the present invention is a display panel having a display unit capable of full-color display. The display unit has a first sub-pixel and a second sub-pixel that emit light of different colors. The first sub-pixel has a first light-emitting device that emits blue light, and the second sub-pixel has a second light-emitting device that emits light of a different color from the first light-emitting device. The first light-emitting device and the second light-emitting device have at least one different material, for example, different light-emitting materials. In other words, in the display panel of one aspect of the present invention, light-emitting devices are made separately for each emitted color.

[0041] A structure in which different light-emitting layers are created or painted for each color of light-emitting device (for example, blue (B), green (G), and red (R)) is sometimes called an SBS (Side By Side) structure. Because the SBS structure allows for the optimization of materials and configuration for each light-emitting device, it increases the freedom of material and configuration selection, making it easier to improve brightness and reliability.

[0042] When manufacturing a display panel having multiple light-emitting devices, each with a different light-emitting color, it is necessary to form the light-emitting layers with different colors in an island-like configuration. In this specification, "island-like configuration" refers to a state in which two or more layers made of the same material and formed in the same process are physically separated. For example, an island-like light-emitting layer refers to a state in which the light-emitting layer and an adjacent light-emitting layer are physically separated.

[0043] For example, island-shaped light-emitting layers can be deposited using a vacuum deposition method with a metal mask (also called a shadow mask). However, with this method, deviations from the design occur in the shape and position of the island-shaped light-emitting layers due to various factors such as the precision of the metal mask, misalignment between the metal mask and the substrate, 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. In addition, the contour of the layer may become blurred during deposition, and the thickness at the edges may become thinner. In other words, the thickness of the island-shaped light-emitting layer may vary depending on the location. Furthermore, when manufacturing large, high-resolution, or high-definition display panels, there is a concern that the low dimensional accuracy of the metal mask and deformation due to heat, etc., may lead to low manufacturing yield.

[0044] In a method for manufacturing a display panel according to one embodiment of the present invention, a first layer (which can be called an EL layer or a part of an EL layer) including a light-emitting layer that emits light of a first color is formed on one surface, and then a first mask layer is formed on the first layer. Then, a first resist mask is formed on the first mask layer, and the first layer and the first mask layer are processed using the first resist mask to form an island-shaped first layer. Subsequently, a second layer (which can be called an EL layer or a part of an EL layer) including a light-emitting layer that emits light of a second color is formed in an island shape using a second mask layer and a second resist mask, similar to the first layer.

[0045] When processing the above-mentioned light-emitting layer into an island shape, a structure in which the processing is performed using photolithography directly above the light-emitting layer is conceivable. In this structure, the light-emitting layer may be damaged (e.g., damage from processing), and its reliability may be significantly impaired. Therefore, when manufacturing a display panel according to one embodiment of the present invention, it is preferable to use a method in which a mask layer or the like is formed on a layer located above the light-emitting layer (for example, a carrier transport layer or carrier injection layer, or more specifically, an electron transport layer or electron injection layer, etc.), and the light-emitting layer is processed into an island shape. By applying this method, a highly reliable display panel can be provided. The mask layer is sometimes also called a sacrificial layer.

[0046] Furthermore, when processing the light-emitting layer into an island shape, it is preferable to process the layer located below the light-emitting layer (for example, a carrier injection layer or carrier transport layer, more specifically a hole injection layer or hole transport layer) into an island shape using the same pattern as the light-emitting layer. By processing the layer located below the light-emitting layer into an island shape using the same pattern as the light-emitting layer, it is possible to reduce the leakage current (sometimes referred to as lateral leakage current, transverse leakage current, or lateral leakage current) that may occur between adjacent subpixels. For example, when a hole injection layer is used in common between adjacent subpixels, a transverse leakage current may occur due to the hole injection layer. On the other hand, in a display device according to one aspect of the present invention, since the hole injection layer can be processed into an island shape using the same pattern as the light-emitting layer, the transverse leakage current between adjacent subpixels is substantially eliminated or can be made extremely small.

[0047] Thus, the island-shaped EL layers produced by the method for manufacturing a display panel according to one embodiment of the present invention are not formed using a metal mask with a fine pattern, but rather by processing after the EL layer has been deposited on one surface. Therefore, it is possible to realize a high-definition display panel or a display panel with a high aperture ratio, which has been difficult to achieve until now. Furthermore, since the EL layer can be made separately for each color, it is possible to realize a display panel that is extremely vivid, has high contrast, and has high display quality. In addition, by providing a mask layer on the EL layer, damage to the EL layer during the display panel manufacturing process can be reduced, and the reliability of the light-emitting device can be improved.

[0048] Furthermore, while it is difficult to reduce the spacing between adjacent light-emitting devices to less than 10 μm using, for example, a formation method employing a fine metal mask, according to one embodiment of the present invention, in a process on a glass substrate, the spacing between adjacent light-emitting devices, adjacent EL layers, or adjacent pixel electrodes can be narrowed to less than 10 μm, 5 μm or less, 3 μm or less, 2 μm or less, 1.5 μm or less, 1 μm or less, or 0.5 μm or less. Moreover, by using, for example, an exposure apparatus for LSIs, in a process on a Si Wafer, the spacing between adjacent light-emitting devices, adjacent EL layers, or adjacent pixel electrodes can be narrowed to, for example, 500 nm or less, 200 nm or less, 100 nm or less, and even 50 nm or less. This significantly reduces the area of ​​the non-emitting region that may exist between two light-emitting devices, making it possible to bring the aperture ratio closer to 100%. For example, in a display device according to one aspect of the present invention, the aperture ratio can be 40% or more, 50% or more, 60% or more, 70% or more, 80% or more, and even 90% or more, while achieving less than 100%.

[0049] Furthermore, increasing the aperture ratio of a display device can improve its reliability. More specifically, using an organic EL device, if the lifespan of a display device with an aperture ratio of 10% is used as a baseline, the lifespan of a display device with an aperture ratio of 20% (i.e., twice the aperture ratio of the baseline) is approximately 3.25 times longer, and the lifespan of a display device with an aperture ratio of 40% (i.e., four times the aperture ratio of the baseline) is approximately 10.6 times longer. Thus, as the aperture ratio is increased, the current density flowing through the organic EL device can be reduced, making it possible to improve the lifespan of the display device. In one embodiment of the present invention, since the aperture ratio can be increased, the display quality of the display device can be improved. Moreover, as the aperture ratio of the display device is increased, the reliability (especially the lifespan) of the display device is significantly improved, which is a great effect.

[0050] Furthermore, the pattern of the EL layer itself can be made extremely small compared to when a metal mask is used. Also, for example, when a metal mask is used to create different EL layers, variations in thickness occur between the center and edges of the pattern, so the effective area that can be used as an emitting region is small relative to the total area of ​​the pattern. On the other hand, with the above manufacturing method, since a film deposited to a uniform thickness is processed, island-shaped EL layers can be formed with a uniform thickness. Therefore, even with a fine pattern, almost the entire area can be used as an emitting region. As a result, display panels that combine high resolution and a high aperture ratio can be manufactured.

[0051] Furthermore, in a method for manufacturing a display panel according to one embodiment of the present invention, it is preferable to first form a layer including an emissive layer (which can be called an EL layer or a part of an EL layer) on one surface, and then form a mask layer on the EL layer. Then, it is preferable to form a resist mask on the mask layer and use the resist mask to process the EL layer and the mask layer to form island-shaped EL layers.

[0052] By providing a mask layer on top of the EL layer, damage to the EL layer during the display panel manufacturing process can be reduced, thereby improving the reliability of the light-emitting device.

[0053] Here, the first layer and the second layer each include at least an emissive layer and preferably consist of multiple layers. Specifically, it is preferable to have one or more layers on the emissive layer. By having other layers between the emissive layer and the mask layer, it is possible to suppress the exposure of the emissive layer to the outermost surface during the display panel manufacturing process and reduce damage to the emissive layer. This can improve the reliability of the light-emitting device. Therefore, it is preferable that the first layer and the second layer each include an emissive layer and a carrier transport layer (electron transport layer or hole transport layer) on the emissive layer.

[0054] Furthermore, in light-emitting devices that emit different colors, it is not necessary to fabricate all layers constituting the EL layer separately; some layers can be formed in the same process. Examples of layers in the EL layer include a light-emitting layer, a carrier injection layer (hole injection layer and electron injection layer), a carrier transport layer (hole transport layer and electron transport layer), and a carrier block layer (hole block layer and electron block layer). In one embodiment of the present invention, a method for manufacturing a display panel involves forming some of the layers constituting the EL layer in island-like structures for each color, then removing at least a portion of the mask layer, and forming the remaining layers constituting the EL layer (sometimes called a common layer) and a common electrode (also called an upper electrode) in common for each color (as a single film). For example, the carrier injection layer and the common electrode can be formed in common for each color.

[0055] On the other hand, the carrier injection layer is often a relatively conductive layer within the EL layer. Therefore, if the carrier injection layer comes into contact with the side surface of some of the island-shaped EL layers, or with the side surface of the pixel electrode, there is a risk of a short circuit in the light-emitting device. Furthermore, even when the carrier injection layer is provided in an island shape and a common electrode is formed common to each color, there is a risk of a short circuit in the light-emitting device if the common electrode comes into contact with the side surface of the EL layer, or with the side surface of the pixel electrode.

[0056] Therefore, a display panel in one embodiment of the present invention has an insulating layer that covers at least the sides of the island-shaped light-emitting layer. The insulating layer may also cover a portion of the upper surface of the island-shaped light-emitting layer. The sides of the island-shaped light-emitting layer referred to here are the interfaces between the island-shaped light-emitting layer and other layers that are not parallel to the substrate (or the surface on which the light-emitting layer is formed). Furthermore, it does not necessarily have to be either a mathematically precise plane or a curved surface.

[0057] This prevents at least a portion of the island-shaped EL layer and the pixel electrodes from coming into contact with the carrier injection layer or common electrode. Therefore, it is possible to suppress short circuits in the light-emitting device and improve the reliability of the light-emitting device.

[0058] Furthermore, it is preferable that the insulating layer functions as a barrier insulating layer against at least one of water and oxygen. It is also preferable that the insulating layer has the function of suppressing the diffusion of at least one of water and oxygen. Furthermore, it is preferable that the insulating layer has the function of capturing or fixing (also called gettering) at least one of water and oxygen.

[0059] In this specification, the term "barrier insulating layer" refers to an insulating layer that has barrier properties. Furthermore, in this specification, "barrier properties" refers to a function that suppresses the diffusion of the corresponding substance (also known as low permeability), or a function that captures or fixes the corresponding substance (also known as gettering).

[0060] By using an insulating layer that functions as a barrier insulating layer or has a gettering function, it is possible to suppress the intrusion of impurities (typically water and at least one of oxygen) that could diffuse from the outside into each light-emitting device. This configuration makes it possible to provide highly reliable light-emitting devices and, furthermore, highly reliable display panels.

[0061] A display panel according to one embodiment of the present invention includes a pixel electrode that functions as an anode, a hole injection layer, a hole transport layer, an emissive layer, an electron transport layer, an electron injection layer, and a common electrode that functions as a cathode. The hole injection layer, hole transport layer, emissive layer, and electron transport layer all have an island-like shape and are provided on the pixel electrode in this order. An insulating layer is provided so as to cover the sides of each of the hole injection layer, hole transport layer, emissive layer, and electron transport layer. The electron injection layer is provided on the electron transport layer, and the common electrode is provided on the electron injection layer.

[0062] Alternatively, a display panel according to one embodiment of the present invention includes a pixel electrode that functions as a cathode, an island-shaped electron injection layer, an electron transport layer, an emissive layer, and a hole transport layer provided in this order on the pixel electrode, an insulating layer provided to cover the respective sides of the electron injection layer, electron transport layer, emissive layer, and hole transport layer, a hole injection layer provided on the hole transport layer, and a common electrode provided on the hole injection layer that functions as an anode.

[0063] Hole injection layers or electron injection layers are often relatively conductive layers within the EL layer. In one embodiment of the present invention, the sides of these layers are covered with an insulating layer, which suppresses contact with common electrodes and the like. Therefore, short circuits in the light-emitting device can be suppressed, and the reliability of the light-emitting device can be improved.

[0064] The insulating layer covering the sides of the island-shaped EL layer may be a single-layer structure or a multi-layer structure.

[0065] For example, by forming a single-layer insulating layer using an inorganic material, the insulating layer can be used as a protective insulating layer for the EL layer. This can improve the reliability of the display panel. Furthermore, it is preferable that the protective insulating layer covers a portion of the upper surface of the EL layer. In such a configuration, the mask layer may remain between the upper surface of the EL layer and the protective insulating layer. Furthermore, it is preferable that the mask layer is an insulating layer using the same inorganic material as the protective insulating film.

[0066] Furthermore, when using a laminated insulating layer structure, the first insulating layer is formed in contact with the EL layer, and therefore it is preferable to form it using an inorganic insulating material. In particular, it is preferable to form it using the atomic layer deposition (ALD) method, which causes less film deposition damage. In addition, it is preferable to form the inorganic insulating layer using the sputtering method, chemical vapor deposition (CVD) method, or plasma-enhanced chemical vapor deposition (PECVD) method, which have a faster film deposition rate than the ALD method. This makes it possible to manufacture highly reliable display panels with high productivity. Furthermore, it is preferable to form the second insulating layer using an organic material so as to flatten the depressions formed in the first insulating layer.

[0067] For example, an aluminum oxide film formed by the ALD method can be used as the first layer of the insulating layer, and an organic resin film can be used as the second layer of the insulating layer. Preferably, a photosensitive acrylic resin is used as the organic resin.

[0068] When the side surface of the EL layer and the organic resin film are in direct contact, organic solvents contained in the organic resin film may damage the EL layer. By using an inorganic insulating film, such as an aluminum oxide film formed by the ALD method, as the first layer of the insulating layer, it is possible to create a configuration in which the organic resin film and the side surface of the EL layer do not come into direct contact. This makes it possible to suppress the dissolution of the EL layer by organic solvents.

[0069] Furthermore, the second insulating layer preferably has a tapered shape with a taper angle θ1 on its side surface when viewed in cross-section of the display device. The taper angle θ1 is the angle between the side surface of the second insulating layer and the substrate surface. The taper angle θ1 is less than 90°, preferably 60° or less, and more preferably 45° or less.

[0070] In this specification, a tapered shape refers to a shape in which at least a portion of the side surface of the structure is inclined with respect to the substrate surface. For example, it is preferable to have a region in which the angle between the inclined side surface and the substrate surface (also called the taper angle) is less than 90°. The side surface of the structure and the substrate surface do not necessarily have to be perfectly flat; they may be substantially planar with a fine curvature, or substantially planar with fine irregularities.

[0071] By giving the side edges of the second insulating layer such a forward taper shape, the common layer and common electrode, which are provided on the side edges of the second insulating layer, can be formed with good coverage without causing stepped breaks or localized thinning. This improves the in-plane uniformity of the common layer and common electrode, thereby improving the display quality of the display device.

[0072] Furthermore, in a cross-sectional view of the display device, it is preferable that the upper surface of the second insulating layer has a convex curved shape. The convex curved shape of the upper surface of the second insulating layer is preferably a shape that bulges gently towards the center. By making the second insulating layer have such a shape, the common layer and common electrode can be formed with good coverage.

[0073] Furthermore, it is preferable that one end of the second insulating layer overlaps with the first pixel electrode, and the other end of the second insulating layer overlaps with the second pixel electrode. With this structure, the end of the second insulating layer can be formed on a generally flat region of the EL layer. Therefore, it becomes relatively easy to process the tapered shape of the second insulating layer.

[0074] Furthermore, in one embodiment of the present invention, since there is no need to provide an insulating layer covering the edges of the pixel electrodes between the pixel electrodes and the EL layer, the spacing between adjacent light-emitting devices can be made extremely narrow. Therefore, the display panel can be made higher resolution or more detailed. In addition, a mask for forming the insulating layer is also unnecessary, which can reduce the manufacturing cost of the display panel.

[0075] Furthermore, by not providing an insulating layer covering the edges of the pixel electrodes between the pixel electrodes and the EL layer, in other words, by not providing an insulating layer between the pixel electrodes and the EL layer, the light emitted from the EL layer can be efficiently extracted. Therefore, a display panel in one embodiment of the present invention can have extremely low viewing angle dependence. By reducing viewing angle dependence, the visibility of images on the display panel can be improved. For example, in a display panel in one embodiment of the present invention, the viewing angle (the maximum angle at which a constant contrast ratio is maintained when viewing the screen from an oblique direction) can be in the range of 100° or more and less than 180°, preferably 150° or more and 170° or less. The above viewing angle can be applied to both vertical and horizontal directions.

[0076] [Example of display panel configuration] Figures 1 to 3 show a display panel according to one embodiment of the present invention.

[0077] Figure 1A shows a top view of the display panel 100. The display panel 100 has a display section in which multiple pixels 110 are arranged, and a connection section 140 outside the display section. Multiple subpixels are arranged in a matrix on the display section. In Figure 1A, two rows and six columns of subpixels are shown, and these constitute two rows and two columns of pixels. The connection section 140 can also be called the cathode contact section.

[0078] The pixel 110 shown in Figure 1A has a stripe arrangement applied to it. The pixel 110 shown in Figure 1A is composed of three subpixels: subpixels 110a, 110b, and 110c. Each of the subpixels 110a, 110b, and 110c has a light-emitting device that emits light of a different color. Examples of subpixels 110a, 110b, and 110c include subpixels of three colors: red (R), green (G), and blue (B); and subpixels of three colors: yellow (Y), cyan (C), and magenta (M). Furthermore, the number of subpixel types is not limited to three, and there may be four or more. Examples of four subpixels include subpixels of four colors: R, G, B, and white (W); subpixels of four colors: R, G, B, and Y; and subpixels of four colors: R, G, B, and infrared (IR).

[0079] In this specification and other documents, the row direction is sometimes referred to as the X direction and the column direction as the Y direction. The X and Y directions intersect, for example, perpendicularly (see Figure 1A).

[0080] Figure 1A shows an example where subpixels of different colors are arranged in the X direction, and an example where subpixels of the same color are arranged in the Y direction.

[0081] Figure 1A shows an example where the connecting portion 140 is located below the display portion in a top view, but it is not particularly limited. The connecting portion 140 only needs to be provided at least one location on the top, right, left, or bottom of the display portion in a top view, and may be provided so as to surround all four sides of the display portion. The top shape of the connecting portion 140 can be a strip, L-shape, U-shape, or frame shape, etc. Also, there may be one or more connecting portions 140.

[0082] Figures 1B and 3C show cross-sectional views between the dashed lines X1 and X2 in Figure 1A. Figures 3A and 3B show cross-sectional views between the dashed lines Y1 and Y2 in Figure 1A.

[0083] As shown in Figure 1B, the display panel 100 has an insulating layer on a layer 101 containing transistors, light-emitting devices 130a, 130b, and 130c on the insulating layer, and a protective layer 131 covering these light-emitting devices. The substrate 120 is bonded to the protective layer 131 by a resin layer 122. In addition, an insulating layer 125 and an insulating layer 127 on the insulating layer 125 are provided in the region between adjacent light-emitting devices.

[0084] In Figure 1B, etc., multiple cross-sections of the insulating layer 125 and insulating layer 127 are shown, but when the display panel 100 is viewed from above, the insulating layer 125 and insulating layer 127 are connected as one unit each. In other words, the display panel 100 can be configured to have, for example, one insulating layer 125 and one insulating layer 127. The display panel 100 may also have multiple insulating layers 125 that are separated from each other, or multiple insulating layers 127 that are separated from each other.

[0085] A display panel in one embodiment 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 device is formed, a bottom-emission type that emits light toward the substrate on which the light-emitting device is formed, or a dual-emission type that emits light on both sides.

[0086] The layer 101 containing the transistors can, for example, be a laminated structure in which multiple transistors are provided on a substrate and an insulating layer is provided to cover these transistors. The insulating layer on the transistors may be a single layer or a laminated structure. Figure 1B and others show the insulating layer on the transistors: insulating layer 255a, insulating layer 255b on insulating layer 255a, and insulating layer 255c on insulating layer 255b. These insulating layers may have recesses between adjacent light-emitting devices. Figure 1B and others show an example in which a recess is provided in the insulating layer 255c.

[0087] Various inorganic insulating films such as oxide insulating films, nitride insulating films, oxidative nitride insulating films, and nitride-oxide insulating films can be suitably used as insulating layers 255a, 255b, and 255c, respectively. For insulating layers 255a and 255c, it is preferable to use oxide insulating films or oxidative nitride insulating films such as silicon oxide films, silicon oxidative nitride films, and aluminum oxide films, respectively. For insulating layer 255b, it is preferable to use nitride insulating films or nitride-oxide insulating films such as silicon nitride films and silicon nitride-oxide films. More specifically, it is preferable to use silicon oxide films as insulating layers 255a and 255c, and silicon nitride films as insulating layer 255b. It is preferable that insulating layer 255b has the function of an etching protective film.

[0088] In this specification, "oxide nitride" refers to a material in which the oxygen content is greater than the nitrogen content, and "nitride oxide" refers to a material in which the nitrogen content is greater than the oxygen content. For example, when "silicon oxynitride" is written, it refers to a material in which the oxygen content is greater than the nitrogen content, and when "silicon nitride oxide" is written, it refers to a material in which the nitrogen content is greater than the oxygen content.

[0089] Examples of the configuration of layer 101 including the transistor will be described later in Embodiments 3 and 4.

[0090] Each of the light-emitting devices 130a, 130b, and 130c emits light of a different color. Preferably, the light-emitting devices 130a, 130b, and 130c are a combination that emits, for example, red (R), green (G), and blue (B) light.

[0091] As the light-emitting devices 130a, 130b, and 130c, it is preferable to use EL devices such as OLEDs (Organic Light Emitting Diodes) or QLEDs (Quantum-dot Light Emitting Diodes). Examples of light-emitting materials for EL devices include fluorescent materials, phosphorescent materials, inorganic compounds (such as quantum dot materials), and thermally activated delayed fluorescence (TADF) materials. As the TADF material, a material in which the singlet excited state and the triplet excited state are in thermal equilibrium may be used. Since such TADF materials have a shorter emission lifetime (excitation lifetime), it is possible to suppress the decrease in efficiency in the high-brightness region of the light-emitting device.

[0092] The light-emitting device has an EL layer between a pair of electrodes. The EL layer has at least a light-emitting layer. In this specification, one of the pair of electrodes may be referred to as the pixel electrode and the other as the common electrode.

[0093] In a light-emitting device, one electrode functions as the anode and the other as the cathode. In the following explanation, we may use the example where the pixel electrode functions as the anode and the common electrode functions as the cathode.

[0094] It is preferable that the ends of each of the pixel electrodes 111a, 111b, and 111c have a tapered shape. Specifically, it is preferable that the ends of each of the pixel electrodes 111a, 111b, and 111c have a tapered shape with a taper angle of less than 90°. When the ends of these pixel electrodes have a tapered shape, the first layer 113a, the second layer 113b, and the third layer 113c provided along the side surface of the pixel electrode also have a tapered shape. By making the side surface of the pixel electrode tapered, the coverage of the EL layer provided along the side surface of the pixel electrode can be improved. Furthermore, by making the side surface of the pixel electrode tapered, it becomes easier to remove foreign matter (for example, dust or particles) during the manufacturing process by washing or other processes, which is preferable.

[0095] The light-emitting device 130a includes a pixel electrode 111a on an insulating layer 255c, an island-shaped first layer 113a on the pixel electrode 111a, a common layer 114 on the island-shaped first layer 113a, and a common electrode 115 on the common layer 114. In the light-emitting device 130a, the first layer 113a and the common layer 114 can be collectively referred to as the EL layer.

[0096] The light-emitting device 130b includes a pixel electrode 111b on an insulating layer 255c, an island-shaped second layer 113b on the pixel electrode 111b, a common layer 114 on the island-shaped second layer 113b, and a common electrode 115 on the common layer 114. In the light-emitting device 130b, the second layer 113b and the common layer 114 can be collectively referred to as the EL layer.

[0097] The light-emitting device 130c includes a pixel electrode 111c on an insulating layer 255c, an island-shaped third layer 113c on the pixel electrode 111c, a common layer 114 on the island-shaped third layer 113c, and a common electrode 115 on the common layer 114. In the light-emitting device 130c, the third layer 113c and the common layer 114 can be collectively referred to as the EL layer.

[0098] The configuration of the light-emitting device in this embodiment is not particularly limited and may be a single structure or a tandem structure.

[0099] In this embodiment, among the EL layers of a light-emitting device, the layers provided in an island-like manner for each light-emitting device are referred to as the first layer 113a, the second layer 113b, and the third layer 113c, and the layer shared by multiple light-emitting devices is referred to as the common layer 114. In this specification and elsewhere, the term EL layer may also refer to the first layer 113a, the second layer 113b, and the third layer 113c, excluding the common layer 114.

[0100] The first layer 113a, the second layer 113b, and the third layer 113c each have at least an emissive layer. For example, it is preferable that the first layer 113a has an emissive layer that emits red light, the second layer 113b has an emissive layer that emits green light, and the third layer 113c has an emissive layer that emits blue light.

[0101] Furthermore, the first layer 113a, the second layer 113b, and the third layer 113c may each have one or more of the following: a hole injection layer, a hole transport layer, a hole blocking layer, a charge generation layer, an electron blocking layer, an electron transport layer, and an electron injection layer.

[0102] For example, the first layer 113a, the second layer 113b, and the third layer 113c may have a hole injection layer, a hole transport layer, an emissive layer, and an electron transport layer. An electron blocking layer may also be present between the hole transport layer and the emissive layer. Furthermore, an electron injection layer may be present on the electron transport layer.

[0103] Furthermore, for example, the first layer 113a, the second layer 113b, and the third layer 113c may have an electron injection layer, an electron transport layer, an emissive layer, and a hole transport layer in that order. A hole blocking layer may also be present between the electron transport layer and the emissive layer. Additionally, a hole injection layer may be present on the hole transport layer.

[0104] Preferably, the first layer 113a, the second layer 113b, and the third layer 113c each have an emissive layer and a carrier transport layer (electron transport layer or hole transport layer) on the emissive layer. Since the surfaces of the first layer 113a, the second layer 113b, and the third layer 113c are exposed during the manufacturing process of the display panel, providing the carrier transport layer on the emissive layer suppresses exposure of the emissive layer to the outermost surface, thereby reducing damage to the emissive layer. This improves the reliability of the light-emitting device.

[0105] Furthermore, the first layer 113a, the second layer 113b, and the third layer 113c each have, for example, a first light-emitting unit, a charge-generating layer, and a second light-emitting unit. For example, it is preferable that the first layer 113a has two or more light-emitting units that emit red light, the second layer 113b has two or more light-emitting units that emit green light, and the third layer 113c has two or more light-emitting units that emit blue light.

[0106] The second light-emitting unit preferably includes a light-emitting layer and a carrier transport layer (electron transport layer or hole transport layer) on the light-emitting layer. Since the surface of the second light-emitting unit is exposed during the manufacturing process of the display panel, providing the carrier transport layer on the light-emitting layer suppresses the exposure of the light-emitting layer to the outermost surface, thereby reducing damage to the light-emitting layer. This improves the reliability of the light-emitting device.

[0107] The common layer 114 may have, for example, an electron injection layer or a hole injection layer. Alternatively, the common layer 114 may have an electron transport layer and an electron injection layer stacked together, or a hole transport layer and a hole injection layer stacked together. The common layer 114 is shared by the light-emitting devices 130a, 130b, and 130c.

[0108] Furthermore, the common electrode 115 is shared by the light-emitting devices 130a, 130b, and 130c. The common electrode 115, which is shared by multiple light-emitting devices, is electrically connected to the conductive layer 123 provided in the connection portion 140 (see Figures 3A and 3B). It is preferable to use a conductive layer for the conductive layer 123 that is made of the same material and formed using the same process as the pixel electrodes 111a, 111b, and 111c.

[0109] In Figure 3A, a common layer 114 is provided on the conductive layer 123, and the conductive layer 123 and the common electrode 115 are electrically connected via the common layer 114. The common layer 114 does not need to be provided at the connection part 140. In Figure 3B, the conductive layer 123 and the common electrode 115 are directly connected. For example, by using a mask to define the film deposition area (also called an area mask or rough metal mask, to distinguish it from a fine metal mask), the areas to be deposited by the common layer 114 and the common electrode 115 can be changed.

[0110] It is preferable to have a protective layer 131 on the light-emitting devices 130a, 130b, and 130c. Providing the protective layer 131 can improve the reliability of the light-emitting devices. The protective layer 131 may be a single layer or a laminated structure of two or more layers.

[0111] The conductivity of the protective layer 131 is not required. The protective layer 131 can be at least one of an insulating film, a semiconductor film, and a conductive film.

[0112] The presence of an inorganic film in the protective layer 131 prevents oxidation of the common electrode 115 and suppresses the intrusion of impurities (such as moisture and oxygen) into the light-emitting device, thereby suppressing degradation of the light-emitting device and improving the reliability of the display panel.

[0113] For example, the protective layer 131 can be an inorganic insulating film such as an oxide insulating film, a nitride insulating film, an oxidative nitride insulating film, and an oxidative nitride insulating film. Examples of oxide insulating films include silicon oxide film, aluminum oxide film, gallium oxide film, germanium oxide film, yttrium oxide film, zirconium oxide film, lanthanum oxide film, neodymium oxide film, hafnium oxide film, and tantalum oxide film. Examples of nitride insulating films include silicon nitride film and aluminum nitride film. Examples of oxidative nitride insulating films include silicon oxidative nitride film and aluminum oxidative nitride film. Examples of oxidative nitride insulating films include silicon oxidative nitride film and aluminum oxide nitride film. In particular, the protective layer 131 preferably has a nitride insulating film or an oxidative nitride insulating film, and more preferably has a nitride insulating film.

[0114] Furthermore, the protective layer 131 may also be an inorganic film containing In-Sn oxide (also known as ITO), In-Zn oxide, Ga-Zn oxide, Al-Zn oxide, or indium gallium zinc oxide (In-Ga-Zn oxide, also known as IGZO). The inorganic film is preferably highly resistive, and more specifically, it is preferably more resistive than the common electrode 115. The inorganic film may further contain nitrogen.

[0115] When the light emitted from a light-emitting device is extracted via a protective layer 131, it is preferable that the protective layer 131 has high transmittance to visible light. For example, ITO, IGZO, and aluminum oxide are preferred because they are inorganic materials with high transmittance to visible light.

[0116] As the protective layer 131, for example, a laminated structure of an aluminum oxide film and a silicon nitride film on the aluminum oxide film, or a laminated structure of an aluminum oxide film and an IGZO film on the aluminum oxide film can be used. By using such a laminated structure, it is possible to suppress impurities (water, oxygen, etc.) from entering the EL layer.

[0117] Furthermore, the protective layer 131 may have an organic film. For example, the protective layer 131 may have both an organic film and an inorganic film. Examples of organic materials that can be used for the protective layer 131 include organic insulating materials that can be used for the insulating layer 127, which will be described later.

[0118] The protective layer 131 may have a two-layer structure formed using different film deposition methods. Specifically, the first layer of the protective layer 131 may be formed using the ALD method, and the second layer of the protective layer 131 may be formed using the sputtering method.

[0119] In Figure 1B and other figures, there is no insulating layer covering the upper edge of the pixel electrode 111a between the pixel electrode 111a and the first layer 113a. Similarly, there is no insulating layer covering the upper edge of the pixel electrode 111b between the pixel electrode 111b and the second layer 113b. Therefore, the spacing between adjacent light-emitting devices can be made extremely narrow. Consequently, a high-definition or high-resolution display panel can be achieved.

[0120] Furthermore, in Figure 1B, etc., a mask layer 118a is located on the first layer 113a of the light-emitting device 130a, a mask layer 118b is located on the second layer 113b of the light-emitting device 130b, and a mask layer 118c is located on the third layer 113c of the light-emitting device 130c. Mask layer 118a is a portion of the mask layer that remained when the first layer 113a was processed and was in contact with the upper surface of the first layer 113a. Similarly, mask layer 118b is a portion of the mask layer that remained when the second layer 113b was formed, and mask layer 118c is a portion of the mask layer that remained when the third layer 113c was formed. Thus, in one embodiment of the present invention, a display panel may have a portion of the mask layer used to protect the EL layer remaining during its manufacture. Any two or all of the mask layers 118a to 118c may be made of the same material, or they may be made of different materials. In the following, mask layers 118a, 118b, and 118c may be collectively referred to as mask layer 118.

[0121] In Figure 1B, one end of the mask layer 118a is aligned with, or approximately aligned with, the end of the first layer 113a, and the other end of the mask layer 118a is located on the first layer 113a. Here, it is preferable that the other end of the mask layer 118a overlaps with the first layer 113a and the pixel electrode 111a. In this case, the other end of the mask layer 118a is more likely to be formed on the approximately flat surface of the first layer 113a. The same applies to the mask layers 118b and 118c. The mask layer 118 remains between, for example, the island-shaped EL layer (first layer 113a, second layer 113b, or third layer 113c) and the insulating layer 125.

[0122] As the mask layer 118, one or more types of materials such as metal films, alloy films, metal oxide films, semiconductor films, organic insulating films, and inorganic insulating films can be used. As the mask layer, various inorganic insulating films that can be used for the protective layer 131 can be used. For example, inorganic insulating materials such as aluminum oxide, hafnium oxide, and silicon oxide can be used.

[0123] As shown in Figure 1B, it is preferable that the insulating layer 125 and insulating layer 127 cover a portion of the upper surface of the island-shaped EL layer (first layer 113a, second layer 113b, or third layer 113c). By covering not only the sides but also the upper surface of the island-shaped EL layer (first layer 113a, second layer 113b, or third layer 113c) with the insulating layer 125 and insulating layer 127, peeling of the EL layer can be further prevented, thereby improving the reliability of the light-emitting device. Furthermore, the manufacturing yield of the light-emitting device can be further improved. Figure 1B shows an example in which the stacked structure of the first layer 113a, mask layer 118a, insulating layer 125, and insulating layer 127 is located on the end of the pixel electrode 111a. Similarly, a stacked structure of a second layer 113b, a mask layer 118b, an insulating layer 125, and an insulating layer 127 is located on the end of the pixel electrode 111b, and a stacked structure of a third layer 113c, a mask layer 118c, an insulating layer 125, and an insulating layer 127 is located on the end of the pixel electrode 111c.

[0124] Figure 1B and others show an example where the edge of the first layer 113a is located outside the edge of the pixel electrode 111a. Although the pixel electrode 111a and the first layer 113a are used as examples, the same can be said for the pixel electrode 111b and the second layer 113b, and the pixel electrode 111c and the third layer 113c.

[0125] In Figure 1B, etc., the first layer 113a is formed to cover the edge of the pixel electrode 111a. This configuration allows for a higher aperture ratio compared to a configuration where the edge of the island-shaped EL layer is located inward from the edge of the pixel electrode.

[0126] Furthermore, by covering the sides of the pixel electrodes with the EL layer, contact between the pixel electrodes and the common electrode 115 can be suppressed, thereby preventing short circuits in the light-emitting device. In addition, the distance between the light-emitting region of the EL layer (i.e., the region overlapping with the pixel electrodes) and the edge of the EL layer can be increased, thereby improving reliability.

[0127] The sides of the first layer 113a, the second layer 113b, and the third layer 113c are covered by insulating layers 127 and 125, respectively. In addition, a portion of the upper surfaces of the first layer 113a, the second layer 113b, and the third layer 113c are covered by insulating layers 127, 125, and a mask layer 118. This prevents the common layer 114 (or common electrode 115) from coming into contact with the sides of the pixel electrodes 111a, 111b, 111c, the first layer 113a, the second layer 113b, and the third layer 113c, thereby suppressing short circuits in the light-emitting device. This improves the reliability of the light-emitting device.

[0128] The insulating layer 125 preferably covers at least one side of the island-shaped EL layer, and more preferably covers both sides of the island-shaped EL layer. The insulating layer 125 can be configured to be in contact with each of the island-shaped EL layers.

[0129] Figure 1B and others show a configuration in which the end of the pixel electrode 111a is covered by the first layer 113a, and the insulating layer 125 is in contact with the side surface of the first layer 113a. Similarly, the end of the pixel electrode 111b is covered by the second layer 113b, and the end of the pixel electrode 111c is covered by the third layer 113c, with the insulating layer 125 in contact with the side surface of the second layer 113b and the side surface of the third layer 113c.

[0130] The insulating layer 127 is provided on the insulating layer 125 so as to fill the recesses formed in the insulating layer 125. The insulating layer 127 can be configured to overlap with a portion of the upper surface and side surfaces of the first layer 113a, the second layer 113b, and the third layer 113c, respectively, via the insulating layer 125.

[0131] By providing insulating layers 125 and 127, the gaps between adjacent island-shaped layers can be filled, thereby reducing extreme irregularities on the formed surface of layers (e.g., carrier injection layers and common electrodes) on the island-shaped layers, making them flatter. Consequently, the coverage of the carrier injection layers and common electrodes can be improved, and step breaks in the common electrodes can be prevented.

[0132] The common layer 114 and common electrode 115 are provided on the first layer 113a, the second layer 113b, the third layer 113c, the mask layer 118, the insulating layer 125, and the insulating layer 127. Before the insulating layer 125 and the insulating layer 127 are provided, a step difference occurs due to the region where the pixel electrode and EL layer are provided and the region where the pixel electrode and EL layer are not provided (the region between light-emitting devices). In one embodiment of the present invention, the display panel can flatten this step difference by having the insulating layer 125 and the insulating layer 127, and the coverage of the common layer 114 and the common electrode 115 can be improved. Therefore, connection failures due to step breaks can be suppressed. In addition, it is possible to suppress the local thinning of the common electrode 115 due to the step difference and the increase in electrical resistance.

[0133] To improve the flatness of the formation surfaces of the common layer 114 and the common electrode 115, it is preferable that the heights of the upper surfaces of the insulating layer 125 and the insulating layer 127 match or approximately match the heights of the upper surfaces at at least one end of the first layer 113a, the second layer 113b, and the third layer 113c, respectively. Furthermore, it is preferable that the upper surface of the insulating layer 127 has a shape with higher flatness, but it may have convex portions, convex curved surfaces, concave curved surfaces, or recesses. For example, it is preferable that the upper surface of the insulating layer 127 has a smooth convex curved shape with high flatness.

[0134] Furthermore, the insulating layer 125 can be provided in contact with the island-shaped EL layers. This prevents the peeling of the island-shaped EL layers. The close contact between the insulating layer and the EL layers provides the effect of fixing or bonding adjacent island-shaped EL layers together. This improves the reliability of the light-emitting device and increases the manufacturing yield of the light-emitting device.

[0135] Here, the insulating layer 125 has a region that is in contact with the side surface of the island-shaped EL layer and functions as a protective insulating layer for the EL layer. By providing the insulating layer 125, it is possible to suppress the intrusion of impurities (oxygen, moisture, etc.) into the interior from the side surface of the island-shaped EL layer, resulting in a highly reliable display panel.

[0136] In one embodiment of the present invention, an insulating layer 127 is provided on the insulating layer 125 so as to fill the recesses formed in the insulating layer 125. The insulating layer 127 is provided between island-shaped EL layers. In other words, in one embodiment of the present invention, a process (hereinafter referred to as process 1) is applied in which island-shaped EL layers are formed, and then an insulating layer 127 is provided so as to overlap with the edges of the island-shaped EL layers. On the other hand, a process different from process 1 is a process (hereinafter referred to as process 2) in which pixel electrodes are formed in an island shape, an insulating film (also referred to as a dam or structure) is formed to cover the edges of the pixel electrodes, and then island-shaped EL layers are formed on the pixel electrodes and the insulating film.

[0137] Process 1 is preferable to Process 2 because it allows for a wider tolerance range in the process. More specifically, Process 1 has a wider tolerance range for alignment accuracy between different patterns than Process 2, and can provide a display device with less variation. Therefore, in a method for manufacturing a display device according to one aspect of the present invention, since the process is similar to Process 1, it is possible to provide a display device with less variation and high display quality.

[0138] Next, examples of materials and formation methods for insulating layers 125 and 127 will be described.

[0139] The insulating layer 125 can be an insulating layer having an inorganic material. For example, inorganic insulating films such as oxide insulating films, nitride insulating films, oxidative nitride insulating films, and nitride oxide insulating films can be used for the insulating layer 125. The insulating layer 125 may be a single layer or a laminated structure. Examples of oxide insulating films include silicon oxide film, aluminum oxide film, magnesium oxide film, indium gallium zinc oxide film, gallium oxide film, germanium oxide film, yttrium oxide film, zirconium oxide film, lanthanum oxide film, neodymium oxide film, hafnium oxide film, and tantalum oxide film. Examples of nitride insulating films include silicon nitride film and aluminum nitride film. Examples of oxidative nitride insulating films include silicon oxidative nitride film and aluminum oxidative nitride film. Examples of nitride oxide insulating films include silicon nitride film and aluminum nitride film. In particular, aluminum oxide is preferred because it has a high selectivity ratio with the EL layer during etching and has the function of protecting the EL layer during the formation of the insulating layer 127, which will be described later. In particular, by applying an inorganic insulating film such as an aluminum oxide film, a hafnium oxide film, or a silicon oxide film formed by the ALD method to the insulating layer 125, it is possible to form an insulating layer 125 with fewer pinholes and excellent protection for the EL layer. Alternatively, the insulating layer 125 may have a laminated structure of a film formed by the ALD method and a film formed by the sputtering method. For example, the insulating layer 125 may have a laminated structure of an aluminum oxide film formed by the ALD method and a silicon nitride film formed by the sputtering method.

[0140] Preferably, the insulating layer 125 functions as a barrier insulating layer against at least one of water and oxygen. Furthermore, preferably, the insulating layer 125 has the function of suppressing the diffusion of at least one of water and oxygen. Also, preferably, the insulating layer 125 has the function of capturing or fixing (also known as gettering) at least one of water and oxygen.

[0141] The insulating layer 125 has the function of a barrier insulating layer or a gettering function, thereby suppressing the intrusion of impurities (typically at least one of water and oxygen) that could diffuse from the outside into each light-emitting device. This configuration makes it possible to provide highly reliable light-emitting devices and, furthermore, highly reliable display panels.

[0142] Furthermore, it is preferable that the insulating layer 125 has a low impurity concentration. This prevents impurities from mixing from the insulating layer 125 into the EL layer and degrading the EL layer. Also, by lowering the impurity concentration in the insulating layer 125, the barrier properties against at least one of water and oxygen can be improved. For example, it is desirable that the insulating layer 125 has a sufficiently low hydrogen concentration and a sufficiently low carbon concentration, preferably both.

[0143] Methods for forming the insulating layer 125 include sputtering, CVD, pulsed laser deposition (PLD), and ALD. It is preferable to form the insulating layer 125 using the ALD method, which provides good coverage.

[0144] By increasing the substrate temperature when forming the insulating layer 125, it is possible to form an insulating layer 125 with a low impurity concentration and high barrier properties against at least one of water and oxygen, even with a thin film thickness. Therefore, the substrate temperature is preferably 60°C or higher, more preferably 80°C or higher, more preferably 100°C or higher, and more preferably 120°C or higher. On the other hand, since the insulating layer 125 is formed after forming island-shaped EL layers, it is preferable to form it at a temperature lower than the heat resistance temperature of the EL layers. Therefore, the substrate temperature is preferably 200°C or lower, more preferably 180°C or lower, more preferably 160°C or lower, more preferably 150°C or lower, and more preferably 140°C or lower.

[0145] Indicators of heat resistance temperature include, for example, the glass transition temperature, softening temperature, melting point, thermal decomposition temperature, and 5% weight loss temperature. The heat resistance temperature of the EL layer can be any of these temperatures, preferably the lowest of these temperatures.

[0146] For the insulating layer 125, it is preferable to form an insulating film with a thickness of, for example, 3 nm or more, 5 nm or more, or 10 nm or more, and 200 nm or less, 150 nm or less, 100 nm or less, or 50 nm or less.

[0147] The insulating layer 127, provided on the insulating layer 125, has the function of flattening the extreme irregularities in the insulating layer 125 formed between adjacent light-emitting devices. In other words, the presence of the insulating layer 127 has the effect of improving the flatness of the surface on which the common electrode 115 is formed.

[0148] As the insulating layer 127, an insulating layer having an organic material can be suitably used. Preferably, a photosensitive organic resin is used as the organic material; for example, a photosensitive acrylic resin may be used. Furthermore, the viscosity of the insulating layer 127 material should be between 1 cP and 1500 cP, and preferably between 1 cP and 12 cP. By setting the viscosity of the insulating layer 127 material within the above range, the tapered insulating layer 127, as described later, can be formed relatively easily. Note that in this specification, the term "acrylic resin" does not refer only to polymethacrylate esters or methacrylic resins, but may refer to acrylic polymers in a broad sense.

[0149] The insulating layer 127 only needs to have a tapered shape on its sides as described later, and the organic materials that can be used as the insulating layer 127 are not limited to those described above. For example, acrylic resin, polyimide resin, epoxy resin, imide resin, polyamide resin, polyimidoamide resin, silicone resin, siloxane resin, benzocyclobutene resin, phenol resin, and precursors of these resins may be used as the insulating layer 127. In addition, organic materials such as polyvinyl alcohol (PVA), polyvinyl butyral, polyvinylpyrrolidone, polyethylene glycol, polyglycerin, pullulan, water-soluble cellulose, or alcohol-soluble polyamide resin may be used as the insulating layer 127. Furthermore, photoresist may be used as the photosensitive resin. The photosensitive resin may be a positive-type material or a negative-type material.

[0150] The insulating layer 127 may be made of a material that absorbs visible light. By absorbing the light emitted from the light-emitting device, the insulating layer 127 can suppress light leakage (stray light) from the light-emitting device to adjacent light-emitting devices through the insulating layer 127. This improves the display quality of the display panel. Furthermore, since the display quality can be improved without using a polarizing plate in the display panel, the display panel can be made lighter and thinner.

[0151] Examples of materials that absorb visible light include materials containing pigments such as black, materials containing dyes, light-absorbing resin materials (e.g., polyimide), and resin materials that can be used as color filters (color filter materials). In particular, it is preferable to use a resin material which is made by laminating or mixing two or more color filter materials, as this can enhance the visible light shielding effect. In particular, by mixing three or more color filter materials, it is possible to create a black or near-black resin layer.

[0152] The insulating layer 127 can be formed using wet film deposition 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, and knife coating. In particular, it is preferable to form the organic insulating film that will become the insulating layer 127 by spin coating.

[0153] The insulating layer 127 is formed at a temperature lower than the heat resistance temperature of the EL layer. The substrate temperature when forming the insulating layer 127 is typically 200°C or lower, preferably 180°C or lower, more preferably 160°C or lower, more preferably 150°C or lower, and more preferably 140°C or lower.

[0154] Here, the structure of the insulating layer 127 and its vicinity will be described using Figures 2A and 2B. Figure 2A is an enlarged cross-sectional view of the region 139 including the insulating layer 127 between light-emitting devices 130a and 130b and its surroundings. In the following description, the insulating layer 127 between light-emitting devices 130a and 130b will be used as an example, but the same applies to the insulating layer 127 between light-emitting devices 130b and 130c, and the insulating layer 127 between light-emitting devices 130c and 130a, etc. Figure 2B is an enlarged view of the vicinity of the edge of the insulating layer 127 on the second layer 113b shown in Figure 2A. In the following description, the edge of the insulating layer 127 on the second layer 113b will be used as an example, but the same applies to the edge of the insulating layer 127 on the first layer 113a, and the edge of the insulating layer 127 on the third layer 113c, etc.

[0155] As shown in Figure 2A, in region 139, a first layer 113a is provided covering the pixel electrode 111a, and a second layer 113b is provided covering the pixel electrode 111b. A mask layer 118a is provided in contact with a part of the upper surface of the first layer 113a, and a mask layer 118b is provided in contact with a part of the upper surface of the second layer 113b. An insulating layer 125 is provided in contact with the upper and side surfaces of the mask layer 118a, the side surfaces of the first layer 113a, the upper surface of the insulating layer 255c, the upper and side surfaces of the mask layer 118b, and the side surfaces of the second layer 113b. An insulating layer 127 is provided in contact with the upper surface of the insulating layer 125. A common layer 114 is provided covering the first layer 113a, the mask layer 118a, the second layer 113b, the mask layer 118b, the insulating layer 125, and the insulating layer 127, and a common electrode 115 is provided on the common layer 114.

[0156] As shown in Figure 2B, the insulating layer 127 preferably has a tapered shape with a taper angle θ1 on its side surface in a cross-sectional view of the display device. The taper angle θ1 is the angle between the side surface of the insulating layer 127 and the substrate surface. However, it is not limited to the substrate surface; it may also be the angle between the side surface of the insulating layer 127 and the upper surface of the flat portion of the insulating layer 125, the upper surface of the flat portion of the second layer 113b, or the upper surface of the flat portion of the pixel electrode 111b.

[0157] The taper angle θ1 of the insulating layer 127 is less than 90°, preferably 60° or less, and more preferably 45° or less. By making the side edges of the insulating layer 127 have such a forward taper shape, the common layer 114 and common electrode 115 provided on the side edges of the insulating layer 127 can be formed with good coverage without causing stepped breaks or localized thinning. As a result, the in-plane uniformity of the common layer 114 and common electrode 115 can be improved, and the display quality of the display device can be improved.

[0158] Furthermore, as shown in Figure 2A, in a cross-sectional view of the display device, it is preferable that the upper surface of the insulating layer 127 has a convex curved shape. The convex curved shape of the upper surface of the insulating layer 127 is preferably a shape that bulges gently towards the center. It is also preferable that the protruding curved portion at the center of the upper surface of the insulating layer 127 is smoothly connected to the tapered portion at the side end. By making the insulating layer 127 such a shape, the common layer 114 and the common electrode 115 can be formed on the entire insulating layer 127 with good coverage.

[0159] Furthermore, as shown in Figure 2A, it is preferable that one end of the insulating layer 127 overlaps with the pixel electrode 111a and the other end of the insulating layer 127 overlaps with the pixel electrode 111b. With this structure, the end of the insulating layer 127 can be formed on a generally flat region of the first layer 113a (second layer 113b). Therefore, it becomes relatively easy to process the tapered shape of the insulating layer 127 as described above.

[0160] In region 139, by providing an insulating layer 127 or the like as described above, it is possible to prevent the formation of stepped sections and locally thinned areas in the common layer 114 and common electrode 115 from the generally flat region of the first layer 113a to the generally flat region of the second layer 113b. Therefore, it is possible to suppress connection failures caused by stepped sections and increases in electrical resistance caused by locally thinned areas in the common layer 114 and common electrode 115 between each light-emitting device. As a result, the display device according to one aspect of the present invention can improve the display quality.

[0161] Furthermore, as shown in Figure 3D, the mask layer 118b and the insulating layer 125 may be configured to have protrusions 116 on the pixel electrode 111b. The protrusions 116 are located outside the edge of the insulating layer 127 in a cross-sectional view of the display device. The mask layer 118a and the insulating layer 125 may also be configured to have similar protrusions 116 on the pixel electrode 111a.

[0162] The protrusion 116, like the insulating layer 127, preferably has a tapered shape on its side when viewed in cross-section of the display device. The taper angle of the protrusion 116 is less than 90°, preferably 60° or less, more preferably 45° or less, and even more preferably 20° or less. The taper angle of the protrusion 116 may be smaller than the taper angle θ1 of the insulating layer 127. By giving the protrusion 116 such a forward taper shape, the common layer 114 and common electrode 115 provided on the protrusion 116 can be coated with good coverage without causing steps or other defects.

[0163] Furthermore, the insulating layer 125 may have a region (hereinafter referred to as the counterbore portion 133) in the protruding portion 116 where the film thickness is thinner than in other parts (for example, the portion overlapping with the insulating layer 127). Depending on the film thickness of the insulating layer 125, the insulating layer 125 may disappear in the protruding portion 116, and the counterbore portion 133 may be formed up to the mask layer 118a or mask layer 118b.

[0164] In Figure 1B and other figures, the film thickness of the first layer 113a to the third layer 113c is shown to be the same, but the present invention is not limited to this. As shown in Figure 3C, the film thickness of each of the first layer 113a to the third layer 113c may be different. The film thickness should be set to correspond to the optical path length that intensifies the light emitted by each of the first layer 113a to the third layer 113c. This makes it possible to realize a microcavity structure and improve the color purity of each light-emitting device.

[0165] For example, if the third layer 113c emits the longest wavelength light and the second layer 113b emits the shortest wavelength light, the thickness of the third layer 113c can be made the thickest and the thickness of the second layer 113b the thinnest. However, this is not limited to this, and the thickness of each EL layer can be adjusted by considering the wavelength of light emitted by each light-emitting element, the optical properties of the layers constituting the light-emitting element, and the electrical properties of the light-emitting element.

[0166] The display panel of this embodiment can reduce the distance between light-emitting devices. Specifically, the distance between light-emitting devices, the distance between EL layers, or the distance between pixel electrodes can be less than 10 μm, 8 μm or less, 5 μm or less, 3 μm or less, 2 μm or less, 1 μm or less, 500 nm or less, 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. In other words, the display panel of this embodiment has a region where the distance between two adjacent island-shaped EL layers is 1 μm or less, preferably a region where the distance is 0.5 μm (500 nm) or less, and more preferably a region where the distance is 100 nm or less.

[0167] A light-shielding layer may be provided on the side of the substrate 120 facing the resin layer 122. Various optical components can also be placed on the outside of the substrate 120. Examples of optical components include polarizing plates, phase difference plates, light diffusion layers (such as diffusion films), anti-reflective layers, and light-gathering films. Furthermore, surface protection layers such as an antistatic film to suppress dust adhesion, a water-repellent film to prevent dirt from adhering, a hard coat film to suppress scratches during use, and an impact-absorbing layer may be placed on the outside of the substrate 120. For example, a glass layer or a silica layer (SiO₂) may be used as the surface protection layer. x By providing a protective layer, surface contamination and scratching can be suppressed, which is preferable. Furthermore, as a surface protective layer, DLC (diamond-like carbon), aluminum oxide (AlO2) x ), polyester-based materials, or polycarbonate-based materials may be used. It is preferable to use a material with high transmittance to visible light for the surface protective layer. Furthermore, it is preferable to use a material with high hardness for the surface protective layer.

[0168] The substrate 120 can be made of glass, quartz, ceramic, sapphire, resin, metal, alloy, semiconductor, etc. The substrate on the side that extracts light from the light-emitting device should be made of a material that transmits the light. Using a flexible material for the substrate 120 can increase the flexibility of the display panel. Alternatively, a polarizing plate may be used as the substrate 120.

[0169] As the substrate 120, various materials can be used, including polyester resins such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN), polyacrylonitrile resin, acrylic resin, polyimide resin, polymethyl methacrylate resin, polycarbonate (PC) resin, polyethersulfone (PES) resin, polyamide resin (nylon, aramid, etc.), polysiloxane resin, cycloolefin resin, polystyrene resin, polyamide-imide resin, polyurethane resin, polyvinyl chloride resin, polyvinylidene chloride resin, polypropylene resin, polytetrafluoroethylene (PTFE) resin, ABS resin, cellulose nanofiber, etc. Glass with a thickness sufficient to provide flexibility may also be used for the substrate 120.

[0170] Furthermore, when a circular polarizing plate is superimposed on a display panel, it is preferable to use a substrate with high optical isotropy for the substrate of the display panel. A substrate with high optical isotropy has low birefringence (or a small amount of birefringence).

[0171] For substrates with high optical isotropy, the absolute value of the retardation (phase difference) is preferably 30 nm or less, more preferably 20 nm or less, and even more preferably 10 nm or less.

[0172] Examples of films with high optical isotropy include triacetylcellulose (TAC, also known as cellulose triacetate) film, cycloolefin polymer (COP) film, cycloolefin copolymer (COC) film, and acrylic resin film.

[0173] Furthermore, when using a film as the substrate, the film may absorb water, potentially causing wrinkles or other shape changes in the display panel. Therefore, it is preferable to use a film with low water absorption for the substrate. For example, it is preferable to use a film with a water absorption rate of 1% or less, more preferable to use a film with a water absorption rate of 0.1% or less, and even more preferable to use a film with a water absorption rate of 0.01% or less.

[0174] As the resin layer 122, various types of curing adhesives can be used, such as UV-curing adhesives, reaction-curing adhesives, thermosetting adhesives, and 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, and 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. Adhesive sheets may also be used.

[0175] As shown in Figure 4A, a pixel can be configured to have four types of subpixels.

[0176] Figure 4A shows a top view of the display panel 100. The display panel 100 has a display section in which a plurality of pixels 110 are arranged in a matrix, and a connection section 140 on the outside of the display section.

[0177] The pixel 110 shown in Figure 4A is composed of four types of subpixels: subpixels 110a, 110b, 110c, and 110d.

[0178] The sub-pixels 110a, 110b, 110c, and 110d can each be configured to have a light-emitting device that emits light of a different color. For example, sub-pixels 110a, 110b, 110c, and 110d can be a set of four sub-pixels with R, G, B, and W colors, a set of four sub-pixels with R, G, B, and Y colors, and a set of four sub-pixels with R, G, B, and IR colors.

[0179] Furthermore, a display panel according to one embodiment of the present invention may have a light-receiving device in each pixel.

[0180] Of the four subpixels of pixel 110 shown in Figure 4A, three may be configured to have light-emitting devices, and the remaining one may be configured to have a light-receiving device.

[0181] For example, a pn-type or pin-type photodiode can be used as the light-receiving device. The light-receiving device functions as a photoelectric conversion device (also called a photoelectric conversion element) that detects light incident on it and generates an electric charge. The amount of charge generated from the light-receiving device is determined by the amount of light incident on it.

[0182] In particular, it is preferable to use an organic photodiode having a layer containing an organic compound as the light-receiving device. 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 panels.

[0183] In one aspect of the present invention, an organic EL device is used as the light-emitting device, and an organic photodiode is used as the light-receiving device. 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 panel using an organic EL device.

[0184] The light-receiving device has an active layer that functions as at least a photoelectric conversion layer between a pair of electrodes. In this specification, one of the pair of electrodes may be referred to as the pixel electrode and the other as the common electrode.

[0185] In a photodetector, one electrode functions as the anode and the other as the cathode. The following explanation uses the example where the pixel electrode functions as the anode and the common electrode functions as the cathode. The photodetector can detect incoming light, generate an electric charge, and extract it as an electric current by applying a reverse bias between the pixel electrode and the common electrode. Alternatively, the pixel electrode may function as the cathode and the common electrode as the anode.

[0186] The same manufacturing methods as for light-emitting devices can be applied to light-receiving devices. The island-shaped active layer (also called the photoelectric conversion layer) of the light-receiving device is not formed by the pattern of the metal mask, but rather by processing after depositing the film that will become the active layer onto the entire surface, so that the island-shaped active layer can be formed with a uniform thickness. In addition, by providing a mask layer on the active layer, the damage that the active layer receives during the display panel manufacturing process can be reduced, and the reliability of the light-receiving device can be improved.

[0187] Figure 4B shows a cross-sectional view between the dashed lines X3 and X4 in Figure 4A. Note that the cross-sectional view between the dashed lines X1 and X2 in Figure 4A can be found in Figure 1B, and the cross-sectional view between the dashed lines Y1 and Y2 can be found in Figure 3A or Figure 3B.

[0188] As shown in Figure 4B, the display panel 100 has an insulating layer on a layer 101 containing transistors, an insulating layer on the insulating layer on a light-emitting device 130a and a light-receiving device 150, a protective layer 131 covering the light-emitting device and the light-receiving device, and a substrate 120 bonded to it by a resin layer 122. In addition, an insulating layer 125 and an insulating layer 127 on the insulating layer 125 are provided in the region between adjacent light-emitting devices and light-receiving devices.

[0189] Figure 4B shows an example where the light-emitting device 130a emits light towards the substrate 120, and light is incident on the light-receiving device 150 from the substrate 120 side (see optical Lem and optical Lin).

[0190] The configuration of the light-emitting device 130a is as described above.

[0191] The light-receiving device 150 includes a pixel electrode 111d on an insulating layer 255c, a fourth layer 113d on the pixel electrode 111d, a common layer 114 on the fourth layer 113d, and a common electrode 115 on the common layer 114. The fourth layer 113d includes at least an active layer.

[0192] The fourth layer 113d is provided on the light-receiving device 150 but not on the light-emitting device. On the other hand, the common layer 114 is a continuous layer shared by the light-emitting device and the light-receiving device.

[0193] Here, layers common to both the light-receiving and light-emitting devices may have different functions in the light-emitting device and the light-receiving device. In this specification, components may be referred to based on their function in the light-emitting device. For example, a hole injection layer functions as a hole injection layer in the light-emitting device and as a hole transport layer in the light-receiving device. Similarly, an electron injection layer functions as an electron injection layer in the light-emitting device and as an electron transport layer in the light-receiving device. Furthermore, layers common to both the light-receiving and light-emitting devices may have the same function in the light-emitting device and the light-receiving device. A hole transport layer functions as a hole transport layer in both the light-emitting and light-receiving devices, and an electron transport layer functions as an electron transport layer in both the light-emitting and light-receiving devices.

[0194] A mask layer 118a is located between the first layer 113a and the insulating layer 125, and a mask layer 118d is located between the fourth layer 113d and the insulating layer 125. Mask layer 118a is a portion of the mask layer that remained after processing the first layer 113a. Mask layer 118d is a portion of the mask layer that remained after processing the fourth layer 113d, which is a layer containing an active layer, by being in contact with the upper surface of the mask layer. Mask layers 118a and 118d may be made of the same material or different materials.

[0195] In a display panel where each pixel has both a light-emitting device and a light-receiving device, the pixels have a light-receiving function, allowing for the detection of contact or proximity of an object while displaying an image. For example, not only can an image be displayed using all of the subpixels of the display panel, but some subpixels can also emit light as a light source, while the remaining subpixels display the image.

[0196] A display panel according to one embodiment of the present invention has a display unit in which light-emitting devices are arranged in a matrix, and an image can be displayed on the display unit. Furthermore, light-receiving devices are arranged in a matrix on the display unit, and in addition to the image display function, the display unit has one or both of the following functions: image capture and / or sensing. The display unit can be used as an image sensor or a touch sensor. That is, by detecting light on the display unit, an image can be captured, or the proximity or contact of an object (such as a finger, hand, or pen) can be detected. Moreover, the display panel according to one embodiment of the present invention can utilize the light-emitting devices as a light source for the sensor. Therefore, it is not necessary to provide a separate light-receiving unit and light source from the display panel, thus reducing the number of components in the electronic device. For example, there is no need to separately provide a fingerprint authentication device or a capacitive touch panel for scrolling, etc., in the electronic device. Therefore, by using the display panel according to one embodiment of the present invention, it is possible to provide an electronic device with reduced manufacturing costs.

[0197] In one embodiment of the present invention, when an object reflects (or scatters) the light emitted by the light-emitting device of the display unit, the light-receiving device can detect the reflected light (or scattered light), thus enabling image capture or touch detection even in dark places.

[0198] When a light-receiving device is used as an image sensor, the display panel can capture images using the light-receiving device. For example, the display panel in this embodiment can be used as a scanner.

[0199] For example, an image sensor can be used to acquire biometric data such as fingerprints and palm prints. In other words, a biometric authentication sensor can be built into the display panel. By integrating the biometric authentication sensor into the display panel, the number of components in the electronic device can be reduced compared to when a separate biometric authentication sensor is provided, enabling miniaturization and weight reduction of the electronic device.

[0200] Furthermore, when a light-receiving device is used as a touch sensor, the display panel can use the light-receiving device to detect the proximity or contact of an object.

[0201] One embodiment of the present invention can have, in addition to an image display function, an imaging function and / or a sensing function. Thus, one embodiment of the present invention can be said to have a configuration that is highly compatible with functions other than display functions.

[0202] Next, we will describe materials that can be used in light-emitting devices.

[0203] Of the pixel electrodes and common electrodes, 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. Additionally, if the display panel has a light-emitting device that emits infrared light, it is preferable to use a conductive film that transmits both visible and infrared light on the electrode that extracts light, and a conductive film that reflects both visible and infrared light on the electrode that does not extract light.

[0204] Furthermore, a conductive film that transmits visible light may also be used on the electrode that does not extract light. In this case, it is preferable to place the electrode between the reflective layer and the EL layer. In other words, the light emitted from the EL layer may be reflected by the reflective layer and extracted from the display panel.

[0205] As materials for forming the pair of electrodes (pixel electrode and common electrode) of a light-emitting device, metals, alloys, electrically conductive compounds, and mixtures thereof can be used as appropriate. Specifically, examples include indium tin oxide (In-Sn oxide, also called ITO), In-Si-Sn oxide (also called ITSO), indium zinc oxide (In-Zn oxide), In-W-Zn oxide, aluminum-containing alloys such as aluminum, nickel, and lanthanum alloys (Al-Ni-La), and silver, palladium, and copper alloys (Ag-Pd-Cu, also written as APC). In addition, metals such as aluminum (Al), titanium (Ti), chromium (Cr), manganese (Mn), iron (Fe), cobalt (Co), nickel (Ni), copper (Cu), gallium (Ga), zinc (Zn), indium (In), tin (Sn), molybdenum (Mo), tantalum (Ta), tungsten (W), palladium (Pd), gold (Au), platinum (Pt), silver (Ag), yttrium (Y), neodymium (Nd), and alloys containing these in appropriate combinations can also be used. Furthermore, elements belonging to Group 1 or Group 2 of the periodic table not exemplified above (e.g., lithium (Li), cesium (Cs), calcium (Ca), strontium (Sr)), rare earth metals such as europium (Eu), ytterbium (Yb), and alloys containing these in appropriate combinations, graphene, etc., can also be used.

[0206] It is preferable that the light-emitting device has a microcavity structure. Therefore, it is preferable that one of the pair of electrodes in the light-emitting device has an electrode that is transparent to and reflective to visible light (a semi-transmissive / semi-reflective electrode), and the other has an electrode that is reflective to visible light (a reflective electrode). By having a microcavity structure in the light-emitting device, the light emitted from the light-emitting layer can be resonated between the two electrodes, thereby strengthening the light emitted from the light-emitting device.

[0207] Furthermore, semi-transmissive / semi-reflective electrodes can have a laminated structure consisting of a reflective electrode and an electrode that transmits visible light (also called a transparent electrode).

[0208] The light transmittance of the transparent electrode shall be 40% or more. For example, for a light-emitting device, it is preferable to use an electrode with a light transmittance of 40% or more for visible light (light with a wavelength of 400 nm or more and less than 750 nm). The reflectance of visible light of the semi-transmissive / semi-reflective electrode shall be 10% or more and 95% or less, preferably 30% or more and 80% or less. The reflectance of visible light of the reflective electrode shall be 40% or more and 100% or less, preferably 70% or more and 100% or less. Also, the resistivity of these electrodes is preferably -2 1×10 Ω·cm or less.

[0209] The light-emitting layer is a layer containing a light-emitting material (also referred to as a luminescent substance). The light-emitting layer can have one or more kinds of luminescent substances. As the luminescent substance, substances that exhibit light-emitting colors such as blue, purple, blue-violet, green, yellow-green, yellow, orange, red, etc. can be appropriately used. Also, as the luminescent substance, a substance that emits near-infrared light can be used.

[0210] Examples of the luminescent substance include fluorescent materials, phosphorescent materials, TADF materials, quantum dot materials, etc.

[0211] Examples of the fluorescent material 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, naphthalene derivatives, etc.

[0212] Examples of the phosphorescent material 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) having a phenylpyridine derivative having an electron-withdrawing group as a ligand, platinum complexes, rare earth metal complexes, etc.

[0213] 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.

[0214] 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 exhibits emission 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 device.

[0215] The first layer 113a, the second layer 113b, and the third layer 113c may each further contain layers other than the light-emitting layer, such as a material with high hole injection properties, a material with high hole transport properties, a hole blocking material, a material with high electron transport properties, 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).

[0216] The light-emitting device may use either low-molecular-weight compounds or high-molecular-weight compounds, and may also contain inorganic compounds. The layers constituting the light-emitting device can be formed by methods such as vapor deposition (including vacuum deposition), transfer, printing, inkjet, and coating.

[0217] For example, the first layer 113a, the second layer 113b, and the third layer 113c may each have one or more of the following: a hole injection layer, a hole transport layer, a hole blocking layer, an electron blocking layer, an electron transport layer, and an electron injection layer.

[0218] The common layer 114 can be one or more of the following: a hole injection layer, a hole transport layer, a hole blocking layer, an electron blocking layer, an electron transport layer, and an electron injection layer. For example, a carrier injection layer (hole injection layer or electron injection layer) may be formed as the common layer 114. Note that the light-emitting device does not necessarily have a common layer 114.

[0219] Preferably, the first layer 113a, the second layer 113b, and the third layer 113c each have an emissive layer and a carrier transport layer on the emissive layer. This suppresses the exposure of the emissive layer to the outermost surface during the manufacturing process of the display panel 100, thereby reducing damage to the emissive layer. This improves the reliability of the light-emitting device.

[0220] 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).

[0221] 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. As for the hole-transporting material, 10 -6 cm 2 Materials having a hole mobility of / Vs or higher are preferred. However, other materials can also be used as long as they have higher hole transport capabilities than electron transport. Preferred hole transport materials include π-electron-rich heteroaromatic compounds (e.g., carbazole derivatives, thiophene derivatives, furan derivatives, etc.) and aromatic amines (compounds having an aromatic amine skeleton), which are materials with high hole transport capabilities.

[0222] The electron transport layer is a layer that transports electrons injected from the cathode by the electron injection layer to the light-emitting layer. The electron transport layer is a layer containing an electron-transporting material. The electron-transporting material is 1 × 10⁻¹⁶ -6 cm 2Materials having an electron mobility of / Vs or higher are preferred. However, other materials can also be used as long as they have higher electron transport capabilities than holes. Examples of electron-transporting materials include metal complexes having a quinoline skeleton, metal complexes having a benzoquinoline skeleton, metal complexes having an oxazole skeleton, metal complexes having a thiazole skeleton, as well as oxadiazole derivatives, triazole derivatives, imidazole derivatives, oxazole derivatives, thiazole derivatives, phenanthroline derivatives, quinoline derivatives having a quinoline ligand, benzoquinoline derivatives, quinoxaline derivatives, dibenzoquinoxaline derivatives, pyridine derivatives, bipyridine derivatives, pyrimidine derivatives, and other π-electron-deficient heteroaromatic compounds containing nitrogen-containing heteroaromatic compounds.

[0223] 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.

[0224] Examples of electron injection layers include lithium, cesium, ytterbium, lithium fluoride (LiF), cesium fluoride (CsF), and calcium fluoride (CaF). x (where X is any number), 8-(quinolinolato)lithium (abbreviation: Liq), 2-(2-pyridyl)phenolatrium (abbreviation: LiPP), 2-(2-pyridyl)-3-pyridinolatrium (abbreviation: LiPPy), 4-phenyl-2-(2-pyridyl)phenolatrium (abbreviation: LiPPP), lithium oxide (LiO x Alkali metals such as cesium carbonate, alkaline earth metals, or compounds thereof can be used. Furthermore, the electron injection layer may be a laminated structure of two or more layers. For example, this laminated structure may consist of lithium fluoride as the first layer and ytterbium as the second layer.

[0225] Alternatively, an electron-transporting material may be used as the electron injection layer. 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.

[0226] Furthermore, it is preferable that the lowest unoccupied molecular orbital (LUMO) level of organic compounds containing lone pairs of electrons is between -3.6 eV and -2.3 eV. In addition, the highest occupied molecular orbital (HOMO) level and LUMO level of organic compounds can generally be estimated by methods such as cyclic voltammetry (CV), photoelectron spectroscopy, optical absorption spectroscopy, and inverse photoelectron spectroscopy.

[0227] For example, 4,7-diphenyl-1,10-phenanthroline (abbreviated as BPhen), 2,9-di(naphthalene-2-yl)-4,7-diphenyl-1,10-phenanthroline (abbreviated as NBPhen), 2,2'-(1,3-phenylene)bis[9-phenyl-1,10-phenanthroline] (abbreviated as mPPhen2P), diquinoxalino[2,3-a:2',3'-c]phenazine (abbreviated as HATNA), and 2,4,6-tris[3'-(pyridine-3-yl)biphenyl-3-yl]-1,3,5-triazine (abbreviated as TmPPPyTz) can be used in organic compounds containing lone pairs of electrons. NBPhen has a higher glass transition temperature (Tg) and superior heat resistance compared to BPhen.

[0228] Furthermore, when fabricating a tandem light-emitting device, a charge generation layer (also called an intermediate layer) is provided between the two light-emitting units. The intermediate layer has the function of injecting electrons into one of the two light-emitting units and holes into the other when a voltage is applied between the pair of electrodes.

[0229] As the charge generation layer, for example, a material applicable to the electron injection layer, such as lithium, can be suitably used. Alternatively, as the charge generation layer, a material applicable to the hole injection layer can be suitably used. Furthermore, the charge generation layer can include a layer containing a hole transport material and an acceptor material (electron-accepting material). Alternatively, the charge generation layer can include a layer containing an electron transport material and a donor material. By forming such a charge generation layer, the increase in driving voltage when light-emitting units are stacked can be suppressed.

[0230] As shown in Figures 1B and 2A, a mask layer 118a is provided in contact with a portion of the upper surface of the first layer 113a. A common electrode 115 is provided in contact with another portion of the upper surface of the first layer 113a. The first layer 113a is then sandwiched between the pixel electrode 111a and the common electrode 115.

[0231] The first layer 113a contains an organic compound OM. For example, the organic compound OM can be used in the light-emitting layer or electron transport layer of the first layer 113a.

[0232] As described above, various organic compounds can be used in the first layer 113a of the light-emitting device. For example, anthracene derivatives can be used in the organic compound OM. Anthracene derivatives are chemically stable compounds in an environment without contact with oxygen. However, when irradiated with light in the presence of oxygen, the oxygen binds to the anthracene skeleton, slowly transforming it into a different compound. As a result, the properties of the light-emitting device change.

[0233] The original organic compound OM contained in the first layer 113a is preferably an organic compound that is resistant to degradation. Furthermore, a manufacturing method that minimizes degradation of the original organic compound OM during the manufacturing process of the light-emitting device is preferred. For example, a method of manufacturing the light-emitting device using an insulating film that blocks contact with oxygen in the atmosphere, in an environment that is shielded from the atmosphere and not exposed to ultraviolet light is preferred. As a result of suppressing the degradation of the organic compound OM, in particular, the amount of oxide of the organic compound OM contained in the first layer 113a is more than 0 and 1 / 10 or less, preferably 1 / 100 or less, and more preferably 1 / 1000 or less, relative to the amount of organic compound OM contained. Note that the oxide of the organic compound OM is mainly an organic compound in which one or two oxygen atoms are bonded to the organic compound OM, and its molecular weight is mainly the organic compound OM plus 16 or 32. Furthermore, as a result of suppressing the alteration of the organic compound OM, the amount of the organic compound having a partial structure of the organic compound OM in the first layer 113a is more than 0 and less than or equal to 1 / 10, preferably less than or equal to 1 / 100, and more preferably less than or equal to 1 / 1000, relative to the amount of the organic compound OM. The organic compound having a partial structure of the organic compound OM is mainly an organic compound formed by the ring-opening of a heteroring contained in the organic compound OM, and its molecular weight is smaller than that of the organic compound OM, and is about the same molecular weight as that of a compound formed by cleaving a heteroring and adding a proton.

[0234] For example, liquid chromatography-mass spectrometry can be used to quantify organic compounds OM, oxides of organic compounds OM, or organic compounds having a partial structure of organic compounds OM.

[0235] [Example of how to create a display panel] Next, using Figures 5 to 9, we will explain an example of a method for manufacturing the display panel 100 shown in Figure 1A and other figures. Figures 5A to 9C show side by side the cross-sectional view between the dashed lines X1 and X2 in Figure 1A, and the cross-sectional view between Y1 and Y2.

[0236] Thin films (insulating films, semiconductor films, and conductive films, etc.) that make up display panels can be formed using sputtering, chemical vapor deposition (CVD), vacuum deposition, pulsed laser deposition (PLD), ALD, and other methods. CVD methods include plasma-enhanced CVD (PECVD) and thermal CVD. One type of thermal CVD is metal-organic CVD (MOCVD).

[0237] Furthermore, the thin films (insulating films, semiconductor films, and conductive films, etc.) that constitute the display panel can be formed by methods such as spin coating, dip coating, spray coating, inkjet printing, dispensing, screen printing, offset printing, doctor knife coating, slit coating, roll coating, curtain coating, and knife coating.

[0238] In particular, vacuum processes such as vapor deposition and solution processes such as spin coating and inkjet can be used to fabricate light-emitting devices. Examples of vapor deposition methods include physical vapor deposition (PVD) methods such as sputtering, ion plating, ion beam deposition, molecular beam deposition, and vacuum deposition, as well as chemical vapor deposition (CVD). Functional layers included in the EL layer (hole injection layer, hole transport layer, light-emitting layer, electron transport layer, electron injection layer, etc.) can be formed by vapor deposition (vacuum deposition, etc.), coating methods (dip coating, die coating, bar coating, spin coating, spray coating, etc.), and printing methods (inkjet, screen printing, offset printing, flexographic printing, gravure, or microcontact printing, etc.).

[0239] Furthermore, when processing the thin film that constitutes the display panel, it can be processed using methods such as photolithography. Alternatively, the thin film may be processed by nanoimprint lithography, sandblasting, or lift-off methods. In addition, island-shaped thin films may be directly formed by a film deposition method using a shielding mask such as a metal mask.

[0240] There are two main methods of photolithography. One method involves forming a resist mask on the thin film to be processed, then processing the thin film by etching or other means, and removing the resist mask. The other method involves forming a photosensitive thin film, then exposing and developing it to process the thin film into the desired shape.

[0241] In photolithography, the light used for exposure can be, for example, i-line (wavelength 365 nm), g-line (wavelength 436 nm), h-line (wavelength 405 nm), or a mixture thereof. Other options include ultraviolet light, KrF laser light, or ArF laser light. Exposure may also be performed using immersion lithography. Furthermore, extreme ultraviolet (EUV) light or X-rays may be used for exposure. An electron beam can also be used instead of light for exposure. Using extreme ultraviolet light, X-rays, or an electron beam is preferable because it allows for extremely fine processing. Note that a photomask is not required when exposure is performed by scanning a beam such as an electron beam.

[0242] For etching thin films, methods such as dry etching, wet etching, and sandblasting can be used.

[0243] First, as shown in Figure 5A, insulating layers 255a, 255b, and 255c are formed on the layer 101 containing the transistor in this order. The insulating layers 255a, 255b, and 255c can be configured in the same way as the insulating layers 255a, 255b, and 255c described above.

[0244] Next, as shown in Figure 5A, pixel electrodes 111a, 111b, 111c and a conductive layer 123 are formed on the insulating layer 255c, a first layer 113A is formed on the pixel electrodes 111a, 111b, 111c, a first mask layer 118A is formed on the first layer 113A, and a second mask layer 119A is formed on the first mask layer 118A.

[0245] As shown in Figure 5A, in the cross-sectional view between Y1 and Y2, the end of the first layer 113A on the connection portion 140 side is located inward from the end of the first mask layer 118A. For example, by using a mask for defining the film deposition area (also called an area mask or rough metal mask, to distinguish it from a fine metal mask), the areas to be deposited by the first layer 113A, the first mask layer 118A, and the second mask layer 119A can be changed. In one embodiment of the present invention, a light-emitting device is formed using a resist mask, but by combining it with an area mask as described above, a light-emitting device can be manufactured in a relatively simple process.

[0246] The pixel electrodes 111a, 111b, and 111c can be configured to meet the same specifications as those described above. For example, sputtering or vacuum deposition can be used to form the pixel electrodes 111a, 111b, and 111c.

[0247] The pixel electrodes 111a, 111b, and 111c are preferably tapered. This improves the coverage of the layer formed on the pixel electrodes 111a, 111b, and 111c, thereby increasing the fabrication yield of the light-emitting device.

[0248] The first layer 113A is the layer that will later become the first layer 113a. Therefore, the configuration applicable to the first layer 113a described above can be applied to it. The first layer 113A can be formed by methods such as vapor deposition (including vacuum deposition), transfer, printing, inkjet, and coating. It is preferable to form the first layer 113A using vapor deposition. In film formation using vapor deposition, a premixed material may be used. In this specification, a premixed material is a composite material obtained by pre-combining or mixing multiple materials.

[0249] The first mask layer 118A and the second mask layer 119A use films that have high resistance to processing conditions, such as the first layer 113A and the second layer 113B and third layer 113C formed in later processes, specifically films that have a high selectivity ratio for etching with various EL layers.

[0250] For forming the first mask layer 118A and the second mask layer 119A, for example, sputtering, ALD (thermal ALD, PEALD), CVD, or vacuum deposition can be used. It is preferable that the first mask layer 118A, which is formed in contact with the EL layer, is formed using a method that causes less damage to the EL layer than the second mask layer 119A. For example, it is preferable to form the first mask layer 118A using ALD or vacuum deposition rather than sputtering. Furthermore, the first mask layer 118A and the second mask layer 119A are formed at a temperature lower than the heat resistance temperature of the EL layer. Typical substrate temperatures when forming the first mask layer 118A and the second mask layer 119A are 200°C or lower, preferably 150°C or lower, more preferably 120°C or lower, more preferably 100°C or lower, and even more preferably 80°C or lower.

[0251] It is preferable to use a film that can be removed by a wet etching method for the first mask layer 118A and the second mask layer 119A. By using the wet etching method, compared with the case of using the dry etching method, the damage applied to the first layer 113A during the processing of the first mask layer 118A and the second mask layer 119A can be reduced.

[0252] In addition, it is preferable to use a film with a large etching selectivity ratio with respect to the second mask layer 119A for the first mask layer 118A.

[0253] In the processing steps of the various mask layers in the method for manufacturing the display panel of the present embodiment, it is desirable that each layer constituting the EL layer (such as a hole injection layer, a hole transport layer, a light emitting layer, and an electron transport layer) is difficult to be processed, and in the processing steps of each layer constituting the EL layer, it is desirable that the various mask layers are difficult to be processed. It is desirable to select the material of the mask layer, the processing method, and the processing method of the EL layer in consideration of these.

[0254] Note that in the present embodiment, an example of forming a mask layer with a two-layer structure of a first mask layer and a second mask layer is shown, but the mask layer may have a single-layer structure or a stacked structure of three or more layers.

[0255] As the first mask layer 118A and the second mask layer 119A, for example, inorganic films such as a metal film, an alloy film, a metal oxide film, a semiconductor film, and an inorganic insulating film can be used respectively.

[0256] For the first mask layer 118A and the second mask layer 119A, 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 the metal materials can be used respectively. In particular, it is preferable to use low melting point materials such as aluminum or silver. By using a metal material capable of shielding ultraviolet light on one or both of the first mask layer 118A and the second mask layer 119A, irradiation of the EL layer with ultraviolet light can be suppressed, and deterioration of the EL layer can be suppressed, which is preferable.

[0257] Also, metal oxides such as In-Ga-Zn oxide can be used for the first mask layer 118A and the second mask layer 119A respectively. As the first mask layer 118A or the second mask layer 119A, for example, an In-Ga-Zn oxide film can be formed using a sputtering method. Furthermore, indium oxide, In-Zn oxide, In-Sn oxide, indium titanium oxide (In-Ti oxide), indium tin zinc oxide (In-Sn-Zn oxide), indium titanium zinc oxide (In-Ti-Zn oxide), indium gallium tin zinc oxide (In-Ga-Sn-Zn oxide), etc. can be used. Or indium tin oxide containing silicon, etc. can also be used.

[0258] Note that instead of the above gallium, an element M (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) can be used. In particular, it is preferable that M is one or more selected from gallium, aluminum, or yttrium.

[0259] Furthermore, various inorganic insulating films that can be used in the protective layer 131 can be used as the first mask layer 118A and the second mask layer 119A, respectively. In particular, oxide insulating films are preferred because they have higher adhesion to the EL layer compared with nitride insulating films. For example, inorganic insulating materials such as aluminum oxide, hafnium oxide, and silicon oxide can be used as the first mask layer 118A and the second mask layer 119A, respectively. For the first mask layer 118A or the second mask layer 119A, an aluminum oxide film can be formed, for example, using the ALD method. Using the ALD method is preferred because it reduces damage to the substrate (especially the EL layer, etc.).

[0260] For example, an inorganic insulating film (e.g., an aluminum oxide film) formed using the ALD method can be used as the first mask layer 118A, and an inorganic film (e.g., an In-Ga-Zn oxide film, an aluminum film, or a tungsten film) formed using the sputtering method can be used as the second mask layer 119A.

[0261] Furthermore, the same inorganic insulating film can be used for both the first mask layer 118A and the insulating layer 125 formed later. For example, an aluminum oxide film formed using the ALD method can be used for both the first mask layer 118A and the insulating layer 125. Here, the same film deposition conditions may be applied to both the first mask layer 118A and the insulating layer 125. For example, by depositing the first mask layer 118A under the same conditions as the insulating layer 125, the first mask layer 118A can be made into an insulating layer with high barrier properties against at least one of water and oxygen. However, this is not limited to this, and different film deposition conditions may be applied to the first mask layer 118A and the insulating layer 125.

[0262] One or both of the first mask layer 118A and the second mask layer 119A may be made of a material that can be dissolved using a solvent that does not damage the film located at least on top of the first layer 113A. In particular, materials that are soluble in water or alcohol can be preferably used. When forming a film of such a material, 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 EL layer.

[0263] The first mask layer 118A and the second mask layer 119A may be formed using a wet film formation method such as spin coating, dip coating, spray coating, inkjet, dispensing, screen printing, offset printing, doctor knife method, slit coating, roll coating, curtain coating, or knife coating, respectively.

[0264] The first mask layer 118A and the second mask layer 119A may each be made of an organic material such as polyvinyl alcohol (PVA), polyvinyl butyral, polyvinylpyrrolidone, polyethylene glycol, polyglycerin, pullulan, water-soluble cellulose, or alcohol-soluble polyamide resin.

[0265] Next, as shown in Figure 5A, a resist mask 190a is formed on the second mask layer 119A. The resist mask can be formed by applying a photosensitive resin (photoresist), exposing it to light, and developing it.

[0266] The resist mask may be made using either a positive-type resist material or a negative-type resist material.

[0267] The resist mask 190a is provided in a position that overlaps with the pixel electrode 111a. Preferably, the resist mask 190a has one island-shaped pattern for each subpixel 110a. Alternatively, the resist mask 190a may have one strip-shaped pattern for multiple subpixels 110a arranged in a row (arranged in the Y direction in Figure 1A).

[0268] If the resist mask 190a is formed such that its edge is located outside the edge of the pixel electrode 111a, then the edge of the first layer 113a, which will be formed later, can be positioned outside the edge of the pixel electrode 111a.

[0269] Furthermore, it is preferable to also provide the resist mask 190a in a position that overlaps with the connection portion 140. This helps to suppress damage to the conductive layer 123 during the manufacturing process of the display panel.

[0270] Next, as shown in Figure 5B, a portion of the second mask layer 119A is removed using the resist mask 190a to form a mask layer 119a. The mask layer 119a remains on the pixel electrode 111a and on the conductive layer 123.

[0271] When etching the second mask layer 119A, it is preferable to use etching conditions with a high selectivity ratio so that the first mask layer 118A is not removed by the etching. Furthermore, since the EL layer is not exposed during the processing of the second mask layer 119A, there is a wider range of processing methods to choose from than for the processing of the first mask layer 118A. Specifically, when processing the second mask layer 119A, even if an oxygen-containing gas is used as the etching gas, the deterioration of the EL layer can be further suppressed.

[0272] Subsequently, the resist mask 190a is removed. For example, the resist mask 190a can be removed by ashing using oxygen plasma. Alternatively, oxygen gas and noble gases (also called rare gases) such as CF4, C4F8, SF6, CHF3, Cl2, H2O, BCl3, or He may be used. Alternatively, the resist mask 190a may be removed by wet etching. In this case, since the first mask layer 118A is located on the outermost surface and the first layer 113A is not exposed, damage to the first layer 113A can be suppressed during the resist mask 190a removal process. Furthermore, the range of selectable methods for removing the resist mask 190a can be broadened.

[0273] Next, as shown in Figure 5C, the mask layer 119a is used as a mask (also called a hard mask) to remove a portion of the first mask layer 118A and form a mask layer 118a.

[0274] The first mask layer 118A and the second mask layer 119A can be processed by wet etching or dry etching, respectively. It is preferable to process the first mask layer 118A and the second mask layer 119A by anisotropic etching.

[0275] By using the wet etching method, the damage to the first layer 113A during processing of the first mask layer 118A and the second mask layer 119A can be reduced compared to using the dry etching method. When using the wet etching method, it is preferable to use chemical solutions such as a developer, an aqueous solution of tetramethylammonium hydroxide (TMAH), dilute hydrofluoric acid, oxalic acid, phosphoric acid, acetic acid, nitric acid, or a mixture thereof.

[0276] When using the dry etching method, deterioration of the first layer 113A can be suppressed by not using a gas containing oxygen as the etching gas. When using the dry etching method, for example, it is preferable to use a gas containing a noble gas (also referred to as a rare gas) such as CF4, C4F8, SF6, CHF3, Cl2, H2O, BCl3, or He as the etching gas.

[0277] For example, when using an aluminum oxide film formed by the ALD method as the first mask layer 118A, CHF3 and He can be used to process the first mask layer 118A by the dry etching method. Also, when using an In-Ga-Zn oxide film formed by the sputtering method as the second mask layer 119A, diluted phosphoric acid can be used to process the second mask layer 119A by the wet etching method. Alternatively, it may be processed by the dry etching method using CH4 and Ar. Alternatively, the second mask layer 119A can be processed by the wet etching method using diluted phosphoric acid. Also, when using a tungsten film formed by the sputtering method as the second mask layer 119A, CF4 and O2, CF6 and O2, CF4 and Cl2 and O2, or CF6 and Cl2 and O2 can be used to process the second mask layer 119A by the dry etching method.

[0278] Next, as shown in FIG. 5C, a part of the first layer 113A is removed by an etching process using the mask layer 119a and the mask layer 118a as hard masks, and the first layer 113a is formed.

[0279] As a result, as shown in FIG. 5C, a laminated structure of the first layer 113a, the mask layer 118a, and the mask layer 119a remains on the pixel electrode 111a. Also, in the region corresponding to the connection portion 140, a laminated structure of the mask layer 118a and the mask layer 119a remains on the conductive layer 123.

[0280] Figure 5C shows an example where the edge of the first layer 113a is located outside the edge of the pixel electrode 111a. This configuration allows for a higher aperture ratio of the pixels. Although not shown in Figure 5C, the etching process may result in the formation of recesses in the region of the insulating layer 255c that does not overlap with the first layer 113a.

[0281] Furthermore, since the first layer 113a covers the top and sides of the pixel electrode 111a, subsequent processes can be carried out without exposing the pixel electrode 111a. If the edges of the pixel electrode 111a are exposed, corrosion may occur during etching processes. Products generated by the corrosion of the pixel electrode 111a may be unstable; for example, in the case of wet etching, they may dissolve in the solution, and in the case of dry etching, there is a concern that they may scatter into the atmosphere. Dissolution of the products into the solution or scattering into the atmosphere may cause the products to adhere to the processed surface and the sides of the first layer 113a, for example, adversely affecting the characteristics of the light-emitting device or potentially forming a leak path between multiple light-emitting devices. In addition, in areas where the edges of the pixel electrode 111a are exposed, the adhesion between layers in contact with each other decreases, which may make the first layer 113a or the pixel electrode 111a more prone to peeling.

[0282] Therefore, by configuring the first layer 113a to cover the top and side surfaces of the pixel electrode 111a, for example, the yield of the light-emitting device can be improved, and the display quality of the light-emitting device can be improved.

[0283] Alternatively, a portion of the first layer 113A may be removed using the resist mask 190a. After that, the resist mask 190a may be removed.

[0284] The first layer 113A is preferably processed by anisotropic etching. In particular, anisotropic dry etching is preferred. Alternatively, wet etching may be used.

[0285] When using the dry etching method, the degradation of the first layer 113A can be suppressed by not using an oxygen-containing gas as the etching gas.

[0286] Furthermore, an etching gas containing oxygen may be used. Including oxygen in the etching gas can increase the etching rate. Therefore, etching can be performed under low power conditions while maintaining a sufficiently fast etching rate. This suppresses damage to the first layer 113A. Additionally, it suppresses problems such as the adhesion of reaction products generated during etching.

[0287] When using the dry etching method, it is preferable to use an etching gas containing one or more noble gases (also called rare gases) such as H2, CF4, C4F8, SF6, CHF3, Cl2, H2O, BCl3, or He, Ar. Alternatively, it is preferable to use an etching gas containing one or more of these and oxygen. Or, oxygen gas may be used as the etching gas. Specifically, for example, a gas containing H2 and Ar, or a gas containing CF4 and He, can be used as the etching gas. Also, for example, a gas containing CF4, He, and oxygen can be used as the etching gas.

[0288] Through the above process, it is possible to remove the areas of the first layer 113A, the first mask layer 118A, and the second mask layer 119A that do not overlap with the resist mask 190a.

[0289] Next, as shown in Figure 6A, a second layer 113B is formed on the mask layer 119a, the pixel electrode 111b, and the pixel electrode 111c, a first mask layer 118B is formed on the second layer 113B, and a second mask layer 119B is formed on the first mask layer 118B.

[0290] As shown in Figure 6A, in the cross-sectional view between Y1 and Y2, the end of the second layer 113B on the connection portion 140 side is located inward from the end of the first mask layer 118B.

[0291] The second layer 113B is the layer that will later become the second layer 113b. The second layer 113b emits light of a different color than the first layer 113a. The configuration and materials applicable to the second layer 113b are the same as those for the first layer 113a. The second layer 113B can be deposited using the same method as the first layer 113A.

[0292] The first mask layer 118B can be formed using a material applicable to the first mask layer 118A. The second mask layer 119B can be formed using a material applicable to the second mask layer 119A.

[0293] Next, as shown in Figure 6A, a resist mask 190b is formed on the second mask layer 119B.

[0294] The resist mask 190b is provided in a position that overlaps with the pixel electrode 111b. The resist mask 190b may also be provided in a position that overlaps with the region that will later become the connection portion 140.

[0295] Next, by performing the same steps as those described using Figures 5B and 5C, the regions of the second layer 113B, the first mask layer 118B, and the second mask layer 119B that do not overlap with the resist mask 190b are removed.

[0296] As a result, as shown in Figure 6B, the stacked structure of the second layer 113b, the mask layer 118b, and the mask layer 119b remains on the pixel electrode 111b. In addition, in the region corresponding to the connection portion 140, the stacked structure of the mask layer 118a and the mask layer 119a remains on the conductive layer 123.

[0297] Next, as shown in Figure 6B, a third layer 113C is formed on the mask layer 119a, the mask layer 119b, and the pixel electrode 111c, a first mask layer 118C is formed on the third layer 113C, and a second mask layer 119C is formed on the first mask layer 118C.

[0298] As shown in Figure 6B, in the cross-sectional view between Y1 and Y2, the end of the third layer 113C on the connection portion 140 side is located inward from the end of the first mask layer 118C.

[0299] The third layer 113C is the layer that will later become the third layer 113c. The third layer 113c emits light of a different color than the first layer 113a and the second layer 113b. The configuration and materials applicable to the third layer 113c are the same as those for the first layer 113a. The third layer 113C can be deposited using the same method as the first layer 113A.

[0300] The first mask layer 118C can be formed using a material applicable to the first mask layer 118A. The second mask layer 119C can be formed using a material applicable to the second mask layer 119A.

[0301] Next, as shown in Figure 6B, a resist mask 190c is formed on the second mask layer 119C.

[0302] The resist mask 190c is provided in a position that overlaps with the pixel electrode 111c. The resist mask 190c may also be provided in a position that overlaps with the region that will later become the connection portion 140.

[0303] Next, by performing the same process as described using Figures 5B and 5C, the areas of the third layer 113C, the first mask layer 118C, and the second mask layer 119C that do not overlap with the resist mask 190c are removed.

[0304] As a result, as shown in Figure 6C, the stacked structure of the third layer 113c, the mask layer 118c, and the mask layer 119c remains on the pixel electrode 111c. In addition, in the region corresponding to the connection portion 140, the stacked structure of the mask layer 118a and the mask layer 119a remains on the conductive layer 123.

[0305] Furthermore, it is preferable that the sides of the first layer 113a, the second layer 113b, and the third layer 113c are perpendicular or approximately perpendicular to the surface to be formed. For example, it is preferable that the angle between the surface to be formed and these sides be 60 degrees or more and 90 degrees or less.

[0306] As described above, by processing each EL layer using photolithography, the distance between each pixel can be narrowed to 8 μm or less, 5 μm or less, 3 μm or less, 2 μm or less, or 1 μm or less. Here, the distance between each pixel can be defined, for example, as the distance between two adjacent opposing ends of the first layer 113a, the second layer 113b, and the third layer 113c. By narrowing the distance between each pixel in this way, a display device with high resolution and a large aperture ratio can be provided.

[0307] Next, as shown in Figure 7A, the mask layers 119a, 119b, and 119c are removed. As a result, the mask layer 118a is exposed on the pixel electrode 111a, the mask layer 118b is exposed on the pixel electrode 111b, the mask layer 118c is exposed on the pixel electrode 111c, and the mask layer 118a is exposed on the conductive layer 123.

[0308] Alternatively, the process may proceed to the formation of the insulating film 125A without removing the mask layers 119a, 119b, and 119c.

[0309] The same method as the mask layer processing method can be used for the mask layer removal process. In particular, by using a wet etching method, the damage inflicted on the first layer 113a, the second layer 113b, and the third layer 113c when removing the mask layer can be reduced compared to when using a dry etching method.

[0310] Alternatively, the mask layer may be removed by dissolving it in a solvent such as water or alcohol. Examples of alcohols include ethyl alcohol, methyl alcohol, isopropyl alcohol (IPA), or glycerin.

[0311] After removing the mask layer, a drying treatment may be performed to remove water contained in the EL layer and water adsorbed on the surface of the EL layer. For example, a heat treatment can be performed in an inert gas atmosphere or a reduced pressure atmosphere. The heat treatment can be performed at a substrate temperature of 50°C to 200°C, preferably 60°C to 150°C, and more preferably 70°C to 120°C. A reduced pressure atmosphere is preferable because it allows drying at a lower temperature.

[0312] Next, as shown in Figure 7A, an insulating film 125A is formed to cover the first layer 113a, the second layer 113b, the third layer 113c, and the mask layers 118a, 118b, and 118c.

[0313] The insulating film 125A is a layer that will later become the insulating layer 125. Therefore, the insulating film 125A can be made of a material that can be used for the insulating layer 125. Furthermore, the thickness of the insulating film 125A is preferably 3 nm or more, 5 nm or more, or 10 nm or more, and 200 nm or less, 150 nm or less, 100 nm or less, or 50 nm or less.

[0314] Since the insulating film 125A is formed in contact with the side surface of the EL layer, it is preferable that it be formed using a method that minimizes damage to the EL layer. Furthermore, the insulating film 125A is formed at a temperature lower than the heat resistance temperature of the EL layer. Typical substrate temperatures when forming the insulating film 125A and the insulating layer 127 are 200°C or lower, preferably 180°C or lower, more preferably 160°C or lower, more preferably 150°C or lower, and more preferably 140°C or lower, respectively.

[0315] For the insulating film 125A, it is preferable to form an aluminum oxide film using, for example, the ALD method. The ALD method is preferable because it can reduce film formation damage and allow for the formation of a film with high coverage. Here, the insulating film 125A can be formed using the same material and method as the mask layers 118a, 118b, and 118c. In this case, the boundary between the insulating film 125A and the mask layers 118a, 118b, and 118c may become unclear.

[0316] Next, as shown in Figure 7B, an insulating layer 127a is applied to the insulating film 125A.

[0317] The insulating layer 127a is a film that will become the insulating layer 127 in a later step, and the above-mentioned organic material can be used for the insulating layer 127a. Preferably, a photosensitive organic resin is used as the organic material; for example, a photosensitive acrylic resin can be used. The viscosity of the insulating layer 127a should be between 1 cP and 1500 cP, and preferably between 1 cP and 12 cP. By setting the viscosity of the insulating layer 127a within the above range, an insulating layer 127 having a tapered shape, as shown in Figure 2A, can be formed relatively easily.

[0318] There are no particular limitations on the method for forming the insulating layer 127a. For example, it can be formed using wet film deposition 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, and knife coating. In particular, it is preferable to form the organic insulating film that will become the insulating layer 127a by spin coating.

[0319] Furthermore, it is preferable to perform a heat treatment after coating the insulating layer 127a. This heat treatment is performed at a temperature lower than the heat resistance temperature of the EL layer. The substrate temperature during the heat treatment should be 50°C to 200°C, preferably 60°C to 150°C, and more preferably 70°C to 120°C. This allows for the removal of solvent contained in the insulating layer 127a.

[0320] Next, as shown in Figure 7C, exposure is performed to expose a portion of the insulating layer 127a to visible light or ultraviolet light. Here, if a positive-type acrylic resin is used for the insulating layer 127a, visible light or ultraviolet light can be irradiated using a mask in the area where the insulating layer 127 will not be formed in a later step. Since the insulating layer 127 is formed in the area sandwiched between any two of the pixel electrodes 111a, 111b, and 111c, visible light or ultraviolet light can be irradiated using a mask on the pixel electrode 111a, on the pixel electrode 111b, and on the pixel electrode 111c, as shown in Figure 7C.

[0321] Furthermore, when using visible light for exposure, it is preferable that the visible light includes the i-line (wavelength 365 nm). In addition, visible light including the g-line (wavelength 436 nm) or the h-line (wavelength 405 nm) may also be used.

[0322] In Figure 7C, an example is shown in which a positive-type photosensitive organic resin is used for the insulating layer 127a, and visible light or ultraviolet light is irradiated into the area where the insulating layer 127 is not formed. However, the present invention is not limited to this. For example, a negative-type photosensitive organic resin may be used for the insulating layer 127a. In this case, it is sufficient to irradiate the area where the insulating layer 127 is formed with visible light or ultraviolet light.

[0323] Next, as shown in Figure 8A, development is performed to remove the exposed area of ​​the insulating layer 127a and form the insulating layer 127b. The insulating layer 127b is formed in the region sandwiched between any two of the pixel electrodes 111a, 111b, and 111c. Here, when acrylic resin is used for the insulating layer 127a, it is preferable to use an alkaline solution as the developer, for example, an aqueous solution of tetramethylammonium hydroxide (TMAH) may be used.

[0324] Next, as shown in Figure 8B, it is preferable to expose the entire substrate and irradiate the insulating layer 127b with visible light or ultraviolet light. The energy density of this exposure is 0 mJ / cm². 2 Even larger, 800 mJ / cm 2 The following is sufficient: 0 mJ / cm2 Larger, 500 mJ / cm 2 The following is preferable: Performing such exposure after development may improve the transparency of the insulating layer 127b. In addition, it may be possible to lower the substrate temperature required for the heat treatment in a later process to deform the insulating layer 127b into a tapered shape.

[0325] Next, as shown in Figure 8C, the insulating layer 127b can be deformed into an insulating layer 127 having a tapered shape on its side by heat treatment. This heat treatment is performed at a temperature lower than the heat resistance temperature of the EL layer. The substrate temperature during the heat treatment should be 50°C to 200°C, preferably 60°C to 150°C, and more preferably 70°C to 130°C. It is preferable to use a higher substrate temperature for this step than for the heat treatment after coating the insulating layer 127. This improves the adhesion of the insulating layer 127 to the insulating film 125A and also improves the corrosion resistance of the insulating layer 127.

[0326] The insulating layer 127 preferably has a tapered shape with a taper angle θ1 on its side surface in a cross-sectional view of the display device, similar to the insulating layer 127 shown in Figure 2A. Furthermore, it is preferable that the upper surface of the insulating layer 127 has a convex curved shape in a cross-sectional view of the display device.

[0327] Here, it is preferable that the insulating layer 127 is reduced in size so that one end overlaps with the pixel electrode 111a and the other end overlaps with the pixel electrode 111b. The pixel electrodes 111a, 111b, and 111c can be appropriately selected depending on the arrangement of the insulating layer 127. With this structure, the end of the insulating layer 127 can be formed on a generally flat region of the first layer 113a (second layer 113b). Therefore, it becomes relatively easy to process the tapered shape of the insulating layer 127 as described above.

[0328] Furthermore, if the insulating layer 127 can be processed into a tapered shape by the heat treatment shown in Figure 8C alone, the configuration shown in Figure 8B may be used without exposure.

[0329] Furthermore, it is preferable to further heat-treat the insulating layer 127 after processing it into a tapered shape. This heat-treat can remove water contained in the EL layer and water adsorbed on the surface of the EL layer. For example, the heat-treat can be performed in an inert gas atmosphere or a reduced-pressure atmosphere. The heat-treat can be performed at a substrate temperature of 80°C to 230°C, preferably 80°C to 200°C, more preferably 80°C to 130°C, and even more preferably 80°C to 100°C. A reduced-pressure atmosphere is preferable because it allows for dehydration at a lower temperature. However, it is preferable to appropriately set the temperature range for the above heat-treat, taking into consideration the heat resistance temperature of the EL layer. When considering the heat resistance temperature of the EL layer, a temperature of 80°C to 100°C is particularly preferable within the above temperature range.

[0330] Furthermore, etching may be performed to adjust the surface height of the insulating layer 127. The insulating layer 127 may also be processed, for example, by ashing using oxygen plasma.

[0331] Next, as shown in Figure 9A, at least a portion of the insulating film 125A and the mask layers 118a, 118b, and 118c are removed to expose the first layer 113a, the second layer 113b, the third layer 113c, and the conductive layer 123.

[0332] The mask layers 118a, 118b, and 118c and the insulating film 125A may be removed in separate steps or in the same step. For example, if the mask layers 118a, 118b, and 118c and the insulating film 125A are films formed using the same material, they can be removed in the same step, which is preferable. For example, it is preferable to form the insulating film for both the mask layers 118a, 118b, and 118c and the insulating film 125A using the ALD method, and it is more preferable to form an aluminum oxide film using the ALD method.

[0333] Furthermore, the mask layer 118a is in contact with the upper surface of the first layer 113a until it is removed, protecting the first layer 113a from damage during the processing steps. Also, the mask layer 118b is in contact with the upper surface of the second layer 113b until it is removed, protecting the second layer 113b from the processing steps. Furthermore, the mask layer 118c is in contact with the upper surface of the third layer 113c until it is removed, protecting the third layer 113c from the processing steps.

[0334] For example, the mask layer 118a blocks the atmosphere and suppresses alteration of the first layer 113a due to atmospheric components. It also attenuates ultraviolet light irradiated during the processing step and suppresses alteration of the first layer 113a due to ultraviolet light. Furthermore, it blocks plasma irradiated during the processing step and suppresses alteration of the first layer 113a due to plasma. It also blocks chemicals or gases used during the processing step and suppresses alteration of the first layer 113a due to components contained in the chemicals or gases.

[0335] For example, organic compounds contained in the first layer 113a may react with oxygen in the atmosphere. In particular, when irradiated with light, the organic compounds become excited, and the reaction with oxygen in the atmosphere is promoted. Specifically, anthracene derivatives are often used in light-emitting or electron-transport layers, but when irradiated with light in the presence of oxygen, oxygen may bond to the anthracene skeleton of the anthracene derivative.

[0336] Here, we will explain the case where oxygen is bonded to the anthracene skeleton using Figure 36. Figure 36 is a conceptual diagram of the case where oxygen is bonded to the anthracene skeleton. As shown in Figure 36, when light is irradiated (ultraviolet light (UV) in Figure 36) to a molecular structure in which substituents are bonded to the 9th and 10th positions of the anthracene skeleton, some of the carbon atoms constituting the anthracene skeleton bond with oxygen that may be present in the atmosphere, resulting in a molecular structure in which two oxygen atoms bridge the middle ring, which is the most reactive of the three condensed rings in the anthracene skeleton.

[0337] The mask layer 118a prevents contact between the anthracene derivative contained in the light-emitting layer or electron transport layer and the atmosphere until it is removed. Therefore, the mask layer 118a suppresses such reactions and protects the first layer 113a. In the above example, the first layer 113a functions as a protective layer to prevent contact between the anthracene derivative and the atmosphere, but the invention is not limited to this. For example, the insulating film 125A may have a similar function to the first layer 113a.

[0338] As shown in Figure 9A, the portion of the insulating film 125A that overlaps with the insulating layer 127 remains as the insulating layer 125. Similarly, the portions of the mask layers 118a, 118b, and 118c that overlap with the insulating layer 127 also remain.

[0339] The insulating layer 125 (and further insulating layer 127) is provided so as to cover a portion of the sides and top surfaces of the pixel electrodes 111a, 111b, 111c, the first layer 113a, the second layer 113b, and the third layer 113c. This prevents the film formed later from coming into contact with the sides of these layers, thereby preventing the light-emitting device from short-circuiting. Furthermore, it helps to suppress damage to the first layer 113a, the second layer 113b, and the third layer 113c in subsequent processes.

[0340] The mask layer removal process can be carried out using the same method as the mask layer processing process. Furthermore, the mask layers 118a, 118b, and 118c can be removed using the same method as the mask layers 119a, 119b, and 119c can be removed. The insulating film 125A can also be removed using the same method as the mask layer removal process.

[0341] Next, as shown in Figure 9B, a common layer 114 is formed to cover the insulating layer 125, insulating layer 127, mask layer 118, first layer 113a, second layer 113b, and third layer 113c.

[0342] The cross-sectional view between Y1 and Y2 shown in Figure 9B illustrates an example where the common layer 114 is not provided at the connection portion 140. As shown in Figure 9B, it is preferable that the end of the common layer 114 on the connection portion 140 side is located inside the connection portion 140. For example, when forming the common layer 114, it is preferable to use a mask (also called an area mask or rough metal mask) to define the film formation area.

[0343] Furthermore, depending on the conductivity of the common layer 114, the common layer 114 may also be provided in the connection portion 140. With this configuration, it is possible to form a connection portion 140 in which the conductive layer 123 is electrically connected to the common electrode 115 via the common layer 114, as shown in Figure 3A.

[0344] The materials that can be used as the common layer 114 are as described above. The common layer 114 can be formed by methods such as vapor deposition (including vacuum deposition), transfer, printing, inkjet, and coating. The common layer 114 may also be formed using a premixed material.

[0345] The common layer 114 is provided so as to cover the upper surfaces of the first layer 113a, the second layer 113b, and the third layer 113c, as well as the upper and side surfaces of the insulating layer 127. If the common layer 114 has high conductivity, there is a risk of a short circuit in the light-emitting device if the common layer 114 comes into contact with any side surface of the pixel electrodes 111a, 111b, 111c, the first layer 113a, the second layer 113b, and the third layer 113c. However, in one embodiment of the present invention, the insulating layers 125 and 127 cover the side surfaces of the first layer 113a, the second layer 113b, and the third layer 113c cover the side surfaces of the corresponding pixel electrodes 111a, 111b, and 111c. This prevents the highly conductive common layer 114 from coming into contact with the sides of these layers, thereby preventing the light-emitting device from short-circuiting. This improves the reliability of the light-emitting device.

[0346] Furthermore, since the spaces between the first layer 113a and the second layer 113b, and between the second layer 113b and the third layer 113c are filled with insulating layers 125 and 127, the surface of the common layer 114 is flatter and has fewer steps than when the insulating layers 125 and 127 are not provided. This improves the coverage of the common layer 114.

[0347] Then, as shown in Figure 9C, a common electrode 115 is formed on the common layer 114 and the conductive layer 123. This allows the conductive layer 123 and the common electrode 115 to be in direct contact and electrically connected. With this configuration, a connection portion 140 can be formed, as shown in Figure 3B, in which the upper surface of the conductive layer 123 and the common electrode 115 are in contact.

[0348] When depositing the common electrode 115, a mask (also called an area mask or rough metal mask) may be used to define the deposition area. Alternatively, the common electrode 115 may be processed after deposition using a resist mask or the like, without using such a mask during deposition.

[0349] The materials that can be used as the common electrode 115 are as described above. For the formation of the common electrode 115, for example, sputtering or vacuum deposition can be used. Alternatively, a film formed by deposition and a film formed by sputtering may be laminated together.

[0350] Furthermore, during the period from when the upper surfaces of the first layer 113a and the second layer 113b are exposed until the common electrode 115 is formed, the first layer 113a and the second layer 113b are not exposed to ultraviolet light. Preferably, for example, the fabrication is carried out in a yellow room where light with a wavelength of 500 nm or less is removed. Specifically, the amount of ultraviolet light with a wavelength of less than 400 nm to which the first layer 113a and the second layer 113b are exposed is set to 0 mJ / cm². 2 Larger, 1000 mJ / cm 2 Preferably, 700 mJ / cm² 2 More preferably, 250 mJ / cm² 2The following will be suppressed.

[0351] Subsequently, a protective layer 131 is formed on the common electrode 115. Furthermore, by using a resin layer 122 to bond the substrate 120 onto the protective layer 131, the display panel 100 shown in Figure 1B can be manufactured.

[0352] The materials and film formation methods that can be used for the protective layer 131 are as described above. Examples of film formation methods for the protective layer 131 include vacuum deposition, sputtering, CVD, and ALD. The protective layer 131 may be a single layer or a multilayer structure.

[0353] In this manner, the display panel 100 described above can be manufactured.

[0354] In one embodiment of the present invention, the display panel has an EL layer arranged in an island-like configuration for each sub-pixel, thereby suppressing the generation of leakage current between sub-pixels. Furthermore, as described above, by providing a laminated structure of an inorganic insulating layer and an organic resin film between each light-emitting device, it is possible to prevent the formation of stepped sections and locally thinned areas in the common layer and common electrode on the laminated structure. Therefore, it is possible to suppress connection failures caused by stepped sections and localized increases in electrical resistance in thinned areas in the common layer and common electrode. As a result, the display device according to one embodiment of the present invention can achieve both high resolution and high display quality.

[0355] This embodiment can be combined with other embodiments as appropriate.

[0356] (Embodiment 2) In this embodiment, a display panel according to one aspect of the present invention will be described with reference to Figures 10 to 13.

[0357] [Pixel layout] This embodiment primarily describes a pixel layout different from that shown in Figure 1A. There are no particular limitations on the arrangement of subpixels, and various methods can be applied. Examples of subpixel arrangements include stripe arrangements, S-stripe arrangements, matrix arrangements, delta arrangements, Bayer arrangements, and pentile arrangements.

[0358] Furthermore, the top surface shape of a sub-pixel can be, for example, a polygon such as a triangle, quadrilateral (including rectangles and squares), or pentagon, or a polygon with rounded corners, or an ellipse or a circle. Here, the top surface shape of a sub-pixel corresponds to the top surface shape of the light-emitting region of the light-emitting device.

[0359] The pixel 110 shown in Figure 10A has an S-stripe array applied to it. The pixel 110 shown in Figure 10A is composed of three subpixels: subpixels 110a, 110b, and 110c. For example, as shown in Figure 12A, subpixel 110a may be a blue subpixel B, subpixel 110b may be a red subpixel R, and subpixel 110c may be a green subpixel G.

[0360] The pixel 110 shown in Figure 10B includes a sub-pixel 110a with a roughly trapezoidal top surface shape with rounded corners, a sub-pixel 110b with a roughly triangular top surface shape with rounded corners, and a sub-pixel 110c with a roughly quadrilateral or hexagonal top surface shape with rounded corners. Furthermore, sub-pixel 110a has a larger light-emitting area than sub-pixel 110b. Thus, the shape and size of each sub-pixel can be determined independently. For example, the size of a sub-pixel can be reduced to a level that provides a more reliable light-emitting device. For example, as shown in Figure 12B, sub-pixel 110a may be a green sub-pixel G, sub-pixel 110b may be a red sub-pixel R, and sub-pixel 110c may be a blue sub-pixel B.

[0361] A Pentile array is applied to pixels 124a and 124b shown in Figure 10C. Figure 10C shows an example in which pixels 124a having subpixels 110a and 110b, and pixels 124b having subpixels 110b and 110c are arranged alternately. For example, as shown in Figure 12C, subpixel 110a may be a red subpixel R, subpixel 110b may be a green subpixel G, and subpixel 110c may be a blue subpixel B.

[0362] Pixels 124a and 124b shown in Figures 10D and 10E utilize a delta array. Pixel 124a has two subpixels (subpixels 110a and 110b) in the top row (1st row) and one subpixel (subpixel 110c) in the bottom row (2nd row). Pixel 124b has one subpixel (subpixel 110c) in the top row (1st row) and two subpixels (subpixels 110a and 110b) in the bottom row (2nd row). For example, as shown in Figure 12D, subpixel 110a may be a red subpixel R, subpixel 110b a green subpixel G, and subpixel 110c a blue subpixel B.

[0363] Figure 10D shows an example where each subpixel has a roughly square top shape with rounded corners, and Figure 10E shows an example where each subpixel has a circular top shape.

[0364] Figure 10F shows an example where the subpixels of each color are arranged in a zigzag pattern. Specifically, in a top view, the upper edges of two subpixels arranged in the column direction (for example, subpixels 110a and 110b, or subpixels 110b and 110c) are offset. For example, as shown in Figure 12E, subpixel 110a may be the red subpixel R, subpixel 110b may be the green subpixel G, and subpixel 110c may be the blue subpixel B.

[0365] In photolithography, the finer the pattern being processed, the more significant the effects of light diffraction become. This compromises the fidelity of the transfer of the photomask pattern through exposure, making it difficult to process the resist mask into the desired shape. Therefore, even if the photomask pattern is rectangular, patterns with rounded corners are likely to be formed. Consequently, the top surface shape of subpixels may be a polygon with rounded corners, an ellipse, or a circle.

[0366] Furthermore, in a method for manufacturing a display panel according to one embodiment of the present invention, the EL layer is processed into an island shape using a resist mask. The resist film formed on the EL layer needs to be cured at a temperature lower than the heat resistance temperature of the EL layer. Therefore, depending on the heat resistance temperature of the EL layer material and the curing temperature of the resist material, the curing of the resist film may be insufficient. A resist film that is not sufficiently cured may take a shape that deviates from the desired shape during processing. As a result, the top surface shape of the EL layer may become a polygon with rounded corners, an ellipse, or a circle. For example, if an attempt is made to form a resist mask with a square top surface, a resist mask with a circular top surface may be formed, resulting in a circular top surface shape for the EL layer.

[0367] Furthermore, in order to achieve the desired shape of the upper surface of the EL layer, a technique (OPC (Optical Proximity Correction) technique) may be used to pre-correct the mask pattern so that the design pattern and the transferred pattern match. Specifically, in the OPC technique, a correction pattern is added to the corners of the shape on the mask pattern.

[0368] Furthermore, even in the pixel 110 to which the stripe arrangement shown in Figure 1A is applied, for example, as shown in Figure 12F, sub-pixel 110a can be a red sub-pixel R, sub-pixel 110b can be a green sub-pixel G, and sub-pixel 110c can be a blue sub-pixel B.

[0369] As shown in Figures 11A to 11H, a pixel can be configured to have four types of subpixels.

[0370] The pixels 110 shown in Figures 11A to 11C are arranged in a stripe pattern.

[0371] Figure 11A shows an example where each subpixel has a rectangular top surface shape, Figure 11B shows an example where each subpixel has a top surface shape formed by connecting two semicircles and a rectangle, and Figure 11C shows an example where each subpixel has an elliptical top surface shape.

[0372] The pixels 110 shown in Figures 11D to 11F are subjected to a matrix array.

[0373] Figure 11D shows an example where each subpixel has a square top surface shape, Figure 11E shows an example where each subpixel has a roughly square top surface shape with rounded corners, and Figure 11F shows an example where each subpixel has a circular top surface shape.

[0374] Figures 11G and 11H show an example where one pixel 110 is composed of 2 rows and 3 columns.

[0375] Pixel 110, shown in Figure 11G, has three subpixels (subpixels 110a, 110b, and 110c) in the top row (row 1) and one subpixel (subpixel 110d) in the bottom row (row 2). In other words, pixel 110 has subpixel 110a in the left column (column 1), subpixel 110b in the middle column (column 2), subpixel 110c in the right column (column 3), and subpixel 110d across these three columns.

[0376] The pixel 110 shown in Figure 11H has three subpixels (subpixels 110a, 110b, and 110c) in the top row (1st row) and three subpixels 110d in the bottom row (2nd row). In other words, the pixel 110 has subpixels 110a and 110d in the left column (1st column), subpixels 110b and 110d in the middle column (2nd column), and subpixels 110c and 110d in the right column (3rd column). As shown in Figure 11H, by aligning the arrangement of subpixels in the top row and the bottom row, it becomes possible to efficiently remove dust and other debris that may occur during the manufacturing process. Therefore, a display panel with high display quality can be provided.

[0377] The pixel 110 shown in Figures 11A to 11H is composed of four subpixels: subpixels 110a, 110b, 110c, and 110d. Each subpixel 110a, 110b, 110c, and 110d has a light-emitting device that emits light of a different color. Examples of subpixels 110a, 110b, 110c, and 110d include subpixels of four colors: R, G, B, and white (W); subpixels of four colors: R, G, B, and Y; or subpixels of R, G, B, and infrared (IR). For example, as shown in Figures 12G to 12J, subpixels 110a, 110b, 110c, and 110d can be red, green, blue, and white subpixels, respectively.

[0378] In one embodiment of the present invention, the display panel may have a light-receiving device in each pixel.

[0379] Of the four subpixels of the pixel 110 shown in Figures 12G to 12J, three may be configured to have light-emitting devices, and the remaining one may be configured to have a light-receiving device.

[0380] For example, sub-pixels 110a, 110b, and 110c may be sub-pixels of three colors: R, G, and B, and sub-pixel 110d may be a sub-pixel having a light-receiving device.

[0381] The pixels shown in Figures 13A and 13B have sub-pixels G, B, R, and PS. The order of the sub-pixels is not limited to the illustrated configuration and can be determined as appropriate. For example, the positions of sub-pixels G and R may be swapped.

[0382] The pixels shown in Figure 13A have a stripe array applied. The pixels shown in Figure 13B have a matrix array applied.

[0383] Sub-pixel R has a light-emitting device that emits red light. Sub-pixel G has a light-emitting device that emits green light. Sub-pixel B has a light-emitting device that emits blue light.

[0384] The sub-pixel PS has a light-receiving device. The wavelength of light detected by the sub-pixel PS is not particularly limited. The sub-pixel PS can be configured to detect either visible light or infrared light, or both.

[0385] The pixels shown in Figures 13C and 13D have sub-pixels G, B, R, X1, and X2. The order of the sub-pixels is not limited to the illustrated configuration and can be determined as appropriate. For example, the positions of sub-pixels G and R may be swapped.

[0386] Figure 13C shows an example where one pixel is provided across two rows and three columns. The top row (row 1) has three subpixels (subpixel G, subpixel B, and subpixel R). In Figure 13C, the bottom row (row 2) has two subpixels (subpixel X1 and subpixel X2).

[0387] Figure 13D shows an example where a single pixel is composed of 3 rows and 2 columns. In Figure 13D, the first row has subpixel G, the second row has subpixel R, and subpixel B spans these two rows. Additionally, the third row has two subpixels (subpixel X1 and subpixel X2). In other words, the pixel shown in Figure 13D has three subpixels (subpixel G, subpixel R, and subpixel X2) in the left column (column 1) and two subpixels (subpixel B and subpixel X1) in the right column (column 2).

[0388] The layout of sub-pixels R, G, and B shown in Figure 13C is a stripe arrangement. Furthermore, the layout of sub-pixels R, G, and B shown in Figure 13D is a so-called S-stripe arrangement. This enables the achievement of high display quality.

[0389] It is preferable that at least one of the sub-pixels X1 and X2 has a light-receiving device (or, it can be said that it is a sub-pixel PS).

[0390] Note that the layout of pixels having sub-pixels PS is not limited to the configurations shown in Figures 13A to 13D.

[0391] For example, a configuration having an infrared (IR) light-emitting device can be applied as sub-pixel X1 or sub-pixel X2. In this case, it is preferable that sub-pixel PS detects infrared light. For example, while displaying an image using sub-pixels R, G, and B, one of sub-pixel X1 and sub-pixel X2 can be used as a light source, and the reflected light emitted by the light source can be detected by the other sub-pixel X1 or sub-pixel X2.

[0392] Furthermore, a configuration can be applied in which both sub-pixel X1 and sub-pixel X2 have a light-receiving device. In this case, the wavelength ranges of the light detected by sub-pixel X1 and sub-pixel X2 may be the same, different, or partially common. For example, one of sub-pixel X1 and sub-pixel X2 may mainly detect visible light, while the other mainly detects infrared light.

[0393] The light-receiving area of ​​sub-pixel X1 is smaller than that of sub-pixel X2. A smaller light-receiving area results in a narrower imaging range, which helps suppress blurring in the image and improves resolution. Therefore, by using sub-pixel X1, it is possible to perform high-definition or high-resolution imaging compared to using the light-receiving device of sub-pixel X2. For example, sub-pixel X1 can be used to perform imaging for personal authentication using fingerprints, palm prints, irises, pulse patterns (including vein and artery patterns), or faces.

[0394] The light-receiving device in the sub-pixel PS preferably detects visible light, and more preferably detects one or more colors such as blue, purple, blue-violet, green, yellow-green, yellow, orange, and red. Alternatively, the light-receiving device in the sub-pixel PS may also detect infrared light.

[0395] Furthermore, when a configuration is applied in which a light-receiving device is included in the sub-pixel X2, the sub-pixel X2 can be used as a touch sensor (also called a direct touch sensor) or a near-touch sensor (also called a hover sensor, hover-touch sensor, non-contact sensor, or touchless sensor). The wavelength of light detected by the sub-pixel X2 can be appropriately determined depending on the application. For example, it is preferable for the sub-pixel X2 to detect infrared light. This enables touch detection even in dark places.

[0396] Here, the touch sensor or near-touch sensor can detect the proximity or contact of an object (such as a finger, hand, or pen).

[0397] A touch sensor can detect an object when the display panel and the object come into direct contact. A near-touch sensor can detect an object even if the object does not come into contact with the display panel. For example, it is preferable that the display panel can detect an object when the distance between the display panel and the object is in the range of 0.1 mm to 300 mm, preferably 3 mm to 50 mm. This configuration makes it possible to operate the display panel without the object directly touching it, in other words, it makes it possible to operate the display panel without contact (touchless). This configuration reduces the risk of the display panel becoming dirty or scratched, or makes it possible to operate the display panel without the object directly touching any dirt (e.g., dust or viruses) attached to the display panel.

[0398] Furthermore, a display panel according to one embodiment of the present invention can have a variable refresh rate. For example, power consumption can be reduced by adjusting the refresh rate according to the content displayed on the display panel (for example, adjusting within a range of 1 Hz to 240 Hz). In addition, the drive frequency of the touch sensor or near touch sensor may be changed according to the refresh rate. For example, if the refresh rate of the display panel is 120 Hz, the drive frequency of the touch sensor or near touch sensor can be set to a frequency higher than 120 Hz (typically 240 Hz). This configuration makes it possible to achieve low power consumption and to increase the response speed of the touch sensor or near touch sensor.

[0399] The display panel 100 shown in Figures 13E to 13G has a layer 353 with a light-receiving device, a functional layer 355, and a layer 357 with a light-emitting device between substrates 351 and 359.

[0400] The functional layer 355 includes circuits for driving a light-receiving device and circuits for driving a light-emitting device. The functional layer 355 may be equipped with switches, transistors, capacitors, resistors, wiring, terminals, etc. However, when the light-emitting and light-receiving devices are driven using a passive matrix system, the configuration may omit switches and transistors.

[0401] For example, as shown in Figure 13E, when a finger 352 touches the display panel 100, it reflects the light emitted by the light-emitting device in layer 357, which has a light-emitting device. The light-receiving device in layer 353 detects this reflected light. This allows the system to detect that the finger 352 has come into contact with the display panel 100.

[0402] Furthermore, as shown in Figures 13F and 13G, the system may also have a function to detect or image objects that are close to (but not in contact with) the display panel. Figure 13F shows an example of detecting a person's finger, and Figure 13G shows an example of detecting information around, on the surface of, or inside a person's eye (such as the number of blinks, eyeball movements, and eyelid movements).

[0403] In this embodiment, the display panel can use a light-receiving device to image the area around the eyes, the surface of the eyes, or the inside of the eyes (such as the fundus) of the wearable device user. Therefore, the wearable device can be equipped with a function to detect one or more of the user's blinking, pupil movement, and eyelid movement.

[0404] As described above, in one embodiment of the present invention, a display panel can be configured to have pixels consisting of subpixels having light-emitting devices, and various layouts can be applied to these pixels. Furthermore, in one embodiment of the present invention, a display panel can be configured to have pixels having both light-emitting devices and light-receiving devices. In this case as well, various layouts can be applied.

[0405] This embodiment can be combined with other embodiments as appropriate.

[0406] (Embodiment 3) In this embodiment, a display panel according to one aspect of the present invention will be described with reference to Figures 14 to 24.

[0407] The display panel of this embodiment can be a high-resolution display panel. Therefore, the display panel of this embodiment can be used, for example, as a display unit for information terminals (wearable devices) such as wristwatches and bracelets, as well as as a display unit for wearable devices that can be worn on the head, such as VR devices such as head-mounted displays and AR devices such as glasses.

[0408] Furthermore, the display panel of this embodiment can be a high-resolution display panel or a large display panel. Therefore, the display panel of this embodiment can be used in electronic devices with relatively large screens, such as television equipment, desktop or notebook personal computers, computer monitors, digital signage, and large game machines such as pachinko machines, as well as in the display units of digital cameras, digital video cameras, digital photo frames, mobile phones, portable game consoles, personal information terminals, and sound playback devices.

[0409] [Display Module] Figure 14A shows a perspective view of the display module 280. The display module 280 includes a display panel 100A and an FPC 290. Note that the display panel of the display module 280 is not limited to display panel 100A, but may be any of the display panels 100B to 100F described later.

[0410] The display module 280 has substrates 291 and 292. The display module 280 has a display unit 281. The display unit 281 is an area in the display module 280 that displays an image, and is an area in which light from each pixel provided in the pixel unit 284, which will be described later, can be seen.

[0411] Figure 14B shows a schematic perspective view illustrating the configuration of the substrate 291. On the substrate 291, a circuit section 282, a pixel circuit section 283 on the circuit section 282, and a pixel section 284 on the pixel circuit section 283 are stacked. In addition, a terminal section 285 for connecting to the FPC 290 is provided in the portion of the substrate 291 that does not overlap with the pixel section 284. The terminal section 285 and the circuit section 282 are electrically connected by a wiring section 286, which is composed of multiple wires.

[0412] The pixel section 284 has multiple pixels 284a arranged periodically. A magnified view of one pixel 284a is shown on the right side of Figure 14B. The pixel 284a has a light-emitting device 130R that emits red light, a light-emitting device 130G that emits green light, and a light-emitting device 130B that emits blue light.

[0413] The pixel circuit section 283 has a plurality of pixel circuits 283a arranged periodically.

[0414] Each pixel circuit 283a is a circuit that controls the light emission of three light-emitting devices in each pixel 284a. A single pixel circuit 283a may also be configured with three circuits that control the light emission of one light-emitting device. For example, each pixel circuit 283a may have at least one selection transistor, one current control transistor (drive transistor), and a capacitive element. In this configuration, a gate signal is input to the gate of the selection transistor, and a source signal is input to the source. This realizes an active-matrix display panel.

[0415] The circuit section 282 has circuits for driving each pixel circuit 283a of the pixel circuit section 283. For example, it is preferable to have one or both of a gate line drive circuit and a source line drive circuit. In addition, it may have at least one of the following: an arithmetic circuit, a memory circuit, and a power supply circuit.

[0416] The FPC290 functions as wiring for supplying video signals or power potential, etc., to the circuit section 282 from an external source. An IC may also be mounted on the FPC290.

[0417] The display module 280 can be configured such that one or both of the pixel circuit section 283 and the circuit section 282 are stacked on the lower side of the pixel section 284, thereby enabling an extremely high aperture ratio (effective display area ratio) of the display section 281. For example, the aperture ratio of the display section 281 can be 40% or more and less than 100%, preferably 50% or more and 95%, and more preferably 60% or more and 95%. Furthermore, it is possible to arrange the pixels 284a at an extremely high density, enabling an extremely high resolution of the display section 281. For example, it is preferable that the pixels 284a in the display section 281 are arranged with a resolution of 20000 ppi or more, preferably 3000 ppi or more, more preferably 5000 ppi or more, and even more preferably 6000 ppi or more, and with a resolution of 20000 ppi or less, or 30000 ppi or less.

[0418] Because such a display module 280 is extremely high-resolution, it can be suitably used in VR devices such as head-mounted displays, or in glasses-type AR devices. For example, even in a configuration where the display part of the display module 280 is viewed through lenses, the display module 280 has an extremely high-resolution display part 281, so even when the display part is magnified with lenses, pixels are not visible, allowing for a highly immersive display. Furthermore, the display module 280 is not limited to this, and can be suitably used in electronic devices with relatively small display parts. For example, it can be suitably used in the display part of wearable electronic devices such as wristwatches.

[0419] [Display Panel 100A] The display panel 100A shown in Figure 15A includes a substrate 301, light-emitting devices 130R, 130G, and 130B, a capacitor 240, and a transistor 310.

[0420] Substrate 301 corresponds to substrate 291 in Figures 14A and 14B. The laminated structure from substrate 301 to insulating layer 255c corresponds to layer 101 containing the transistor in Embodiment 1.

[0421] The transistor 310 is a transistor having a channel-forming region in the substrate 301. The substrate 301 can be a semiconductor substrate such as a single-crystal silicon substrate. The transistor 310 comprises a portion of the substrate 301, a conductive layer 311, a low-resistance region 312, an insulating layer 313, and an insulating layer 314. The conductive layer 311 functions as a gate electrode. The insulating layer 313 is located between the substrate 301 and the conductive layer 311 and functions as a gate insulating layer. The low-resistance region 312 is a region of the substrate 301 doped with impurities and functions as either a source or a drain. The insulating layer 314 covers the side surface of the conductive layer 311 and functions as an insulating layer.

[0422] Furthermore, an element isolation layer 315 is provided between two adjacent transistors 310 so as to be embedded in the substrate 301.

[0423] Furthermore, an insulating layer 261 is provided covering the transistor 310, and a capacitance 240 is provided on the insulating layer 261.

[0424] The capacitor 240 has a conductive layer 241, a conductive layer 245, and an insulating layer 243 located between them. The conductive layer 241 acts as one electrode of the capacitor 240, the conductive layer 245 acts as the other electrode of the capacitor 240, and the insulating layer 243 acts as the dielectric of the capacitor 240.

[0425] 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.

[0426] An insulating layer 255a is provided covering the capacitance 240, an insulating layer 255b is provided on the insulating layer 255a, and an insulating layer 255c is provided on the insulating layer 255b.

[0427] Various inorganic insulating films such as oxide insulating films, nitride insulating films, oxidative nitride insulating films, and nitride oxide insulating films can be suitably used as insulating layers 255a, 255b, and 255c, respectively. For insulating layers 255a and 255c, it is preferable to use oxide insulating films or oxidative nitride insulating films such as silicon oxide films, silicon oxidative nitride films, and aluminum oxide films, respectively. For insulating layer 255b, it is preferable to use nitride insulating films or nitride oxide insulating films such as silicon nitride films and silicon nitride oxide films. More specifically, it is preferable to use silicon oxide films for insulating layers 255a and 255c, and silicon nitride films for insulating layer 255b. It is preferable that insulating layer 255b functions as an etching protective film. In this embodiment, an example is shown in which a recess is provided in insulating layer 255c, but the insulating layer 255c does not necessarily have to have a recess.

[0428] Light-emitting devices 130R, 130G, and 130B are provided on the insulating layer 255c. Figure 15A shows an example in which light-emitting devices 130R, 130G, and 130B have the layered structure shown in Figure 1B.

[0429] The display panel 100A has a first layer 113a, a second layer 113b, and a third layer 113c that are separated and spaced apart from each other. Therefore, even with a high-resolution display panel, crosstalk between adjacent sub-pixels can be suppressed. Thus, a display panel that is both high-resolution and has high display quality can be realized.

[0430] An insulator is provided in the region between adjacent light-emitting devices. In Figure 15A, for example, an insulating layer 125 and an insulating layer 127 on top of the insulating layer 125 are provided in this region.

[0431] A mask layer 118a is located on the first layer 113a of the light-emitting device 130R, a mask layer 118b is located on the second layer 113b of the light-emitting device 130G, and a mask layer 118c is located on the third layer 113c of the light-emitting device 130B.

[0432] The pixel electrodes 111a, 111b, and 111c of the light-emitting device are electrically connected to either the source or drain of the transistor 310 by plugs 256 embedded in insulating layers 255a, 255b, and 255c, a conductive layer 241 embedded in insulating layer 254, and plugs 271 embedded in insulating layer 261. The height of the upper surface of insulating layer 255c and the height of the upper surface of plug 256 are equal or approximately equal. Various conductive materials can be used for the plugs. Figure 15A, etc., shows an example in which the pixel electrode has a two-layer structure consisting of a reflective electrode and a transparent electrode on the reflective electrode.

[0433] Furthermore, a protective layer 131 is provided on the light-emitting devices 130R, 130G, and 130B. A substrate 120 is bonded to the protective layer 131 by a resin layer 122. Details of the components from the light-emitting devices to the substrate 120 can be found in Embodiment 1. The substrate 120 corresponds to the substrate 292 in Figure 14A.

[0434] There is no insulating layer covering the upper edge of the pixel electrode 111a between the pixel electrode 111a and the first layer 113a. Similarly, there is no insulating layer covering the upper edge of the pixel electrode 111b between the pixel electrode 111b and the second layer 113b. Therefore, the spacing between adjacent light-emitting devices can be made extremely narrow. Consequently, a high-definition or high-resolution display panel can be achieved.

[0435] In the example shown for display panel 100A, an example having light-emitting devices 130R, 130G, and 130G is provided, but the display panel of this embodiment may further have a light-receiving device.

[0436] The display panel shown in Figure 15B is an example having light-emitting devices 130R, 130G, and a light-receiving device 150. The light-receiving device 150 has a pixel electrode 111d, a fourth layer 113d, a common layer 114, and a common electrode 115 stacked together. For details on the components of the light-receiving device 150, please refer to Embodiment 1.

[0437] [Display Panel 100B] The display panel 100B shown in Figure 16 has a configuration in which transistors 310A and 310B, each with a channel formed on a semiconductor substrate, are stacked. In the following description of the display panel, parts that are the same as those described earlier may be omitted.

[0438] The display panel 100B has a configuration in which a substrate 301B on which a transistor 310B, a capacitor 240, and a light-emitting device are provided, and a substrate 301A on which a transistor 310A is provided are bonded together.

[0439] Here, it is preferable to provide an insulating layer 345 on the lower surface of substrate 301B. It is also preferable to provide an insulating layer 346 on top of the insulating layer 261 provided on substrate 301A. Insulating layers 345 and 346 are insulating layers that function as protective layers and can suppress the diffusion of impurities into substrates 301B and 301A. As insulating layers 345 and 346, inorganic insulating films that can be used for protective layer 131 or insulating layer 332 can be used.

[0440] A plug 343 is provided on the substrate 301B, penetrating both the substrate 301B and the insulating layer 345. It is preferable to provide an insulating layer 344 covering the sides of the plug 343. The insulating layer 344 functions as a protective layer and can suppress the diffusion of impurities into the substrate 301B. An inorganic insulating film, usable for the protective layer 131, can be used as the insulating layer 344.

[0441] Furthermore, a conductive layer 342 is provided on the back side of the substrate 301B (the side opposite to the substrate 120 side), beneath the insulating layer 345. Preferably, the conductive layer 342 is provided so as to be embedded in the insulating layer 335. Also, preferably, the undersides of the conductive layer 342 and the insulating layer 335 are flattened. Here, the conductive layer 342 is electrically connected to the plug 343.

[0442] On the other hand, the substrate 301A has a conductive layer 341 provided on an insulating layer 346. Preferably, the conductive layer 341 is provided so as to be embedded in the insulating layer 336. Furthermore, it is preferable that the upper surfaces of the conductive layer 341 and the insulating layer 336 are flattened.

[0443] The conductive layer 341 and the conductive layer 342 are bonded together, thereby electrically connecting the substrate 301A and the substrate 301B. By improving the flatness of the surface formed by the conductive layer 342 and the insulating layer 335, and the surface formed by the conductive layer 341 and the insulating layer 336, the bonding of the conductive layer 341 and the conductive layer 342 can be improved.

[0444] It is preferable to use the same conductive material for conductive layer 341 and conductive layer 342. For example, a metal film containing an element selected from Al, Cr, Cu, Ta, Ti, Mo, and W, or a metal nitride film (titanium nitride film, molybdenum nitride film, tungsten nitride film) composed of the above elements can be used. In particular, it is preferable to use copper for conductive layer 341 and conductive layer 342. This makes it possible to apply Cu-Cu (copper-copper) direct bonding technology (a technology that achieves electrical conductivity by connecting Cu (copper) pads to each other).

[0445] [Display Panel 100C] The display panel 100C shown in Figure 17 has a configuration in which conductive layer 341 and conductive layer 342 are joined via bumps 347.

[0446] As shown in Figure 17, the conductive layer 341 and the conductive layer 342 can be electrically connected by providing a bump 347 between them. The bump 347 can be formed using a conductive material containing, for example, gold (Au), nickel (Ni), indium (In), or tin (Sn). Solder may also be used as the bump 347. An adhesive layer 348 may also be provided between the insulating layer 345 and the insulating layer 346. Furthermore, when the bump 347 is provided, the insulating layer 335 and the insulating layer 336 may be omitted.

[0447] [Display Panel 100D] The display panel 100D shown in Figure 18 differs from the display panel 100A mainly in its transistor configuration.

[0448] Transistor 320 is an OS transistor in which a metal oxide (also called an oxide semiconductor) is applied to the semiconductor layer where the channel is formed.

[0449] The transistor 320 has a semiconductor layer 321, an insulating layer 323, a conductive layer 324, a pair of conductive layers 325, an insulating layer 326, and a conductive layer 327.

[0450] Substrate 331 corresponds to substrate 291 in Figures 14A and 14B. The laminated structure from substrate 331 to insulating layer 255b corresponds to layer 101 containing the transistor in Embodiment 1. An insulating substrate or a semiconductor substrate can be used as substrate 331.

[0451] An insulating layer 332 is provided on the substrate 331. The insulating layer 332 functions as a barrier layer that prevents impurities such as water or hydrogen from diffusing from the substrate 331 to the transistor 320, and prevents oxygen from detaching from the semiconductor layer 321 to the insulating layer 332. As the insulating layer 332, for example, a film that is less susceptible to hydrogen or oxygen diffusion than a silicon oxide film can be used, such as an aluminum oxide film, a hafnium oxide film, or a silicon nitride film.

[0452] A conductive layer 327 is provided on an insulating layer 332, and an insulating layer 326 is provided covering the conductive layer 327. The conductive layer 327 functions as the first gate electrode of the transistor 320, and a portion of the insulating layer 326 functions as the first gate insulating layer. It is preferable to use an oxide insulating film, such as a silicon oxide film, for at least the portion of the insulating layer 326 that is in contact with the semiconductor layer 321. It is preferable that the upper surface of the insulating layer 326 is flattened.

[0453] The semiconductor layer 321 is provided on the insulating layer 326. Preferably, the semiconductor layer 321 has a metal oxide (also called an oxide semiconductor) film having semiconductor properties. A pair of conductive layers 325 are provided in contact with the semiconductor layer 321 and function as a source electrode and a drain electrode.

[0454] An insulating layer 328 is provided covering the top and side surfaces of a pair of conductive layers 325, as well as the side surfaces of the semiconductor layer 321, and an insulating layer 264 is provided on the insulating layer 328. The insulating layer 328 functions as a barrier layer to prevent impurities such as water or hydrogen from diffusing into the semiconductor layer 321 from the insulating layer 264, etc., and to prevent oxygen from detaching from the semiconductor layer 321. An insulating film similar to that used for the insulating layer 332 can be used for the insulating layer 328.

[0455] 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.

[0456] The upper surfaces of the conductive layer 324, the insulating layer 323, and the insulating layer 264 are flattened so that their heights are the same or approximately the same, and the insulating layer 329 and insulating layer 265 are provided covering them.

[0457] 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.

[0458] A plug 274, which is electrically connected to one of the pair of conductive layers 325, is provided so as to be embedded in the insulating layers 265, 329, and 264. Here, it is preferable that the plug 274 has a conductive layer 274a that covers the sides of the openings of the insulating layers 265, 329, 264, and 328, and a part of the upper surface of the conductive layer 325, and a conductive layer 274b that is in contact with the upper surface of the conductive layer 274a. In this case, it is preferable to use a conductive material that does not easily allow hydrogen and oxygen to diffuse as the conductive layer 274a.

[0459] [Display Panel 100E] The display panel 100E shown in Figure 19 has a configuration in which transistors 320A and 320B, each having an oxide semiconductor in the semiconductor where the channel is formed, are stacked.

[0460] The configuration of transistors 320A and 320B, and their surrounding components, can be referenced from the display panel 100D described above.

[0461] In this example, we have used a configuration in which two transistors having oxide semiconductors are stacked, but this is not the only option. For example, a configuration in which three or more transistors are stacked may also be used.

[0462] [Display Panel 100F] The display panel 100F shown in Figure 20 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.

[0463] 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.

[0464] 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.

[0465] This configuration allows for the formation of not only pixel circuits but also drive circuits directly beneath the light-emitting device, making it possible to miniaturize the display panel compared to cases where the drive circuits are located around the display area.

[0466] [Display Panel 100G] Figure 21 shows a perspective view of the display panel 100G, and Figure 22A shows a cross-sectional view of the display panel 100G.

[0467] The display panel 100G has a configuration in which substrate 152 and substrate 151 are bonded together. In Figure 21, substrate 152 is clearly indicated by a dashed line.

[0468] The display panel 100G includes a display unit 162, a connection unit 140, a circuit 164, wiring 165, etc. Figure 21 shows an example in which IC 173 and FPC 172 are mounted on the display panel 100G. Therefore, the configuration shown in Figure 21 can also be described as a display module having a display panel 100G, an IC (integrated circuit), and an FPC.

[0469] The connection portion 140 is provided on the outside of the display portion 162. The connection portion 140 can be provided along one or more sides of the display portion 162. There may be one or more connection portions 140. Figure 21 shows an example in which the connection portion 140 is provided so as to surround all four sides of the display portion. At the connection portion 140, the common electrode of the light-emitting device and the conductive layer are electrically connected, and a potential can be supplied to the common electrode.

[0470] For example, a scan line drive circuit can be used as circuit 164.

[0471] Wiring 165 has the function of supplying signals and power to the display unit 162 and the circuit 164. These signals and power are input to wiring 165 from an external source via FPC 172 or from IC 173.

[0472] Figure 21 shows an example in which IC 173 is provided on the substrate 151 using the COG (Chip On Glass) method or COF (Chip On Film) method, etc. IC 173 can be an IC having, for example, a scan line drive circuit or a signal line drive circuit. Note that the display panel 100G and the display module may be configured without an IC. Alternatively, the IC may be mounted on an FPC using the COF method, etc.

[0473] Figure 22A shows an example of a cross-section of the display panel 100G when a portion of the area including the FPC 172, a portion of the circuit 164, a portion of the display unit 162, a portion of the connection unit 140, and a portion of the area including the end are cut.

[0474] The display panel 100G shown in Figure 22A includes a transistor 201, a transistor 205, a light-emitting device 130R that emits red light, a light-emitting device 130G that emits green light, and a light-emitting device 130B that emits blue light, etc., between substrates 151 and 152.

[0475] The light-emitting devices 130R, 130G, and 130B each have the stacked structure shown in Figure 1B, except that they differ in the configuration of their pixel electrodes. For details of the light-emitting devices, please refer to Embodiment 1.

[0476] The display panel 100G has a first layer 113a, a second layer 113b, and a third layer 113c that are separated and spaced apart from each other. Therefore, even with a high-resolution display panel, crosstalk between adjacent subpixels can be suppressed. Thus, a display panel that is both high-resolution and has high display quality can be realized.

[0477] The light-emitting device 130R has a conductive layer 112a, a conductive layer 126a on the conductive layer 112a, and a conductive layer 129a on the conductive layer 126a. All of the conductive layers 112a, 126a, and 129a can be called pixel electrodes, or only a part of them can be called pixel electrodes.

[0478] The light-emitting device 130G has a conductive layer 112b, a conductive layer 126b on the conductive layer 112b, and a conductive layer 129b on the conductive layer 126b.

[0479] The light-emitting device 130B includes a conductive layer 112c, a conductive layer 126c on the conductive layer 112c, and a conductive layer 129c on the conductive layer 126c.

[0480] The conductive layer 112a is connected to the conductive layer 222b of the transistor 205 through an opening provided in the insulating layer 214. The edge of the conductive layer 126a is located outside the edge of the conductive layer 112a. The edges of the conductive layer 126a and the conductive layer 129a are aligned or approximately aligned. For example, conductive layers that function as reflective electrodes can be used for conductive layers 112a and 126a, and a conductive layer that functions as a transparent electrode can be used for conductive layer 129a.

[0481] The conductive layers 112b, 126b, and 129b in the light-emitting device 130G, and the conductive layers 112c, 126c, and 129c in the light-emitting device 130B, are the same as the conductive layers 112a, 126a, and 129a in the light-emitting device 130R, so a detailed explanation is omitted.

[0482] Recesses are formed in the conductive layers 112a, 112b, and 112c so as to cover the openings provided in the insulating layer 214. Layer 128 is embedded in these recesses.

[0483] Layer 128 has the function of flattening the recesses of the conductive layers 112a, 112b, and 112c. Conductive layers 126a, 126b, and 126c, which are electrically connected to conductive layers 112a, 112b, and 112c, are provided on conductive layers 112a, 112b, and 112c and on layer 128. Therefore, regions overlapping with the recesses of conductive layers 112a, 112b, and 112c can also be used as light-emitting regions, thereby increasing the aperture ratio of the pixels.

[0484] Layer 128 may be an insulating layer or a conductive layer. Various inorganic insulating materials, organic insulating materials, and conductive materials can be used for layer 128 as appropriate. In particular, it is preferable that layer 128 be formed using an insulating material.

[0485] As layer 128, an insulating layer having an organic material can be suitably used. For example, acrylic resin, polyimide resin, epoxy resin, polyamide resin, polyimidoamide resin, siloxane resin, benzocyclobutene resin, phenol resin, and precursors of these resins can be used as layer 128. Alternatively, a photosensitive resin can be used as layer 128. The photosensitive resin can be a positive-type material or a negative-type material.

[0486] By using a photosensitive resin, layer 128 can be fabricated using only exposure and development processes, reducing the impact on the surfaces of conductive layers 112a, 112b, and 112c due to dry etching or wet etching. Furthermore, by forming layer 128 using a negative-type photosensitive resin, it may be possible to form layer 128 using the same photomask (exposure mask) used to form the openings of the insulating layer 214.

[0487] The top and side surfaces of conductive layer 126a and conductive layer 129a are covered by the first layer 113a. Similarly, the top and side surfaces of conductive layer 126b and conductive layer 129b are covered by the second layer 113b. Furthermore, the top and side surfaces of conductive layer 126c and conductive layer 129c are covered by the third layer 113c. Therefore, the entire region where conductive layers 126a, 126b, and 126c are provided can be used as the light-emitting region of light-emitting devices 130R, 130G, and 130B, thereby increasing the aperture ratio of the pixels.

[0488] The sides of the first layer 113a, the second layer 113b, and the third layer 113c are covered by insulating layers 125 and 127, respectively. A mask layer 118a is located between the first layer 113a and the insulating layer 125. A mask layer 118b is located between the second layer 113b and the insulating layer 125, and a mask layer 118c is located between the third layer 113c and the insulating layer 125. A common layer 114 is provided on the first layer 113a, the second layer 113b, the third layer 113c, and the insulating layers 125 and 127, and a common electrode 115 is provided on the common layer 114. The common layer 114 and the common electrode 115 are continuous films provided in common to multiple light-emitting devices.

[0489] Furthermore, a protective layer 131 is provided on each of the light-emitting devices 130R, 130G, and 130B. By providing a protective layer 131 that covers the light-emitting devices, it is possible to suppress the ingress of impurities such as water into the light-emitting devices and improve the reliability of the light-emitting devices.

[0490] The protective layer 131 and the substrate 152 are bonded together via an adhesive layer 142. For sealing the light-emitting device, a solid sealing structure or a hollow sealing structure can be applied. In Figure 22A, the space between the substrate 152 and the substrate 151 is filled with the adhesive layer 142, indicating a solid sealing structure. Alternatively, the space may be filled with an inert gas (such as nitrogen or argon), indicating a hollow sealing structure. In this case, the adhesive layer 142 may be provided so as not to overlap with the light-emitting device. Furthermore, the space may be filled with a resin different from the adhesive layer 142, which surrounds the device in a frame-like manner.

[0491] In the connection portion 140, a conductive layer 123 is provided on the insulating layer 214. The conductive layer 123 is shown as an example of a laminated structure consisting of a conductive film obtained by processing the same conductive film as conductive layers 112a, 112b, and 112c, a conductive film obtained by processing the same conductive film as conductive layers 126a, 126b, and 126c, and a conductive film obtained by processing the same conductive film as conductive layers 129a, 129b, and 129c. The ends of the conductive layer 123 are covered by a mask layer 118a, an insulating layer 125, and an insulating layer 127. A common layer 114 is provided on the conductive layer 123, and a common electrode 115 is provided on the common layer 114. The conductive layer 123 and the common electrode 115 are electrically connected via the common layer 114. Note that the common layer 114 does not necessarily have to be formed in the connection portion 140. In this case, the conductive layer 123 and the common electrode 115 are in direct contact and electrically connected.

[0492] The display panel 100G is a top-emission type. The light emitted by the light-emitting device is emitted towards the substrate 152. It is preferable to use a material with high transmittance to visible light for the substrate 152. The pixel electrodes contain a material that reflects visible light, and the counter electrodes (common electrodes 115) contain a material that transmits visible light.

[0493] The laminated structure from the substrate 151 to the insulating layer 214 corresponds to the layer 101 containing the transistor in Embodiment 1.

[0494] Both transistors 201 and 205 are formed on the substrate 151. These transistors can be manufactured using the same materials and the same process.

[0495] On the substrate 151, insulating layers 211, 213, 215, and 214 are provided 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.

[0496] It is preferable to use a material that does not easily allow impurities such as water and hydrogen to diffuse into at least one layer of the insulating layer covering the transistor. This allows the insulating layer to function as a barrier layer. With such a configuration, the diffusion of impurities from the outside into the transistor can be effectively suppressed, thereby improving the reliability of the display panel.

[0497] It is preferable to use inorganic insulating films for insulating layer 211, insulating layer 213, and insulating layer 215. Examples of inorganic insulating films that can be used include silicon nitride film, silicon oxide nitride film, silicon oxide film, silicon nitride oxide film, aluminum oxide film, and aluminum nitride film. Alternatively, hafnium oxide film, yttrium oxide film, zirconium oxide film, gallium oxide film, tantalum oxide film, magnesium oxide film, lanthanum oxide film, cerium oxide film, and neodymium oxide film may also be used. Furthermore, two or more of the above insulating films may be laminated together.

[0498] An organic insulating layer is preferred as the insulating layer 214 that functions as a planarizing layer. Examples of materials that can be used for the organic insulating layer include acrylic resin, polyimide resin, epoxy resin, polyamide resin, polyimidoamide resin, siloxane resin, benzocyclobutene resin, phenol resin, and precursors of these resins. Alternatively, the insulating layer 214 may have a laminated structure of an organic insulating layer and an inorganic insulating layer. The outermost layer of the insulating layer 214 preferably functions as an etching protection layer. This makes it possible to suppress the formation of depressions in the insulating layer 214 when processing conductive layers 112a, 126a, or 129a. Alternatively, depressions may be provided in the insulating layer 214 when processing conductive layers 112a, 126a, or 129a.

[0499] Transistors 201 and 205 have a conductive layer 221 that functions as a gate, an insulating layer 211 that functions as a gate insulating layer, conductive layers 222a and 222b that function as source and drain, a semiconductor layer 231, an insulating layer 213 that functions as a gate insulating layer, and a conductive layer 223 that functions as a gate. Here, the same hatching pattern is applied to multiple layers obtained by processing the same conductive film. The insulating layer 211 is located between the conductive layer 221 and the semiconductor layer 231. The insulating layer 213 is located between the conductive layer 223 and the semiconductor layer 231.

[0500] The transistor structure of the display panel in this embodiment is not particularly limited. For example, planar transistors, staggered transistors, inverse staggered transistors, etc., can be used. Furthermore, either a top-gate or bottom-gate transistor structure may be used. Alternatively, gates may be provided above and below the semiconductor layer in which the channel is formed.

[0501] Transistors 201 and 205 are configured in which a semiconductor layer on which a channel is formed is sandwiched between two gates. The transistors may be driven by connecting the two gates and supplying them with the same signal. Alternatively, the threshold voltage of the transistors may be controlled by applying a potential to control the threshold voltage to one of the two gates and a potential to drive the other gate.

[0502] The crystallinity of the semiconductor material used in the transistor is not particularly limited; amorphous semiconductors, crystalline semiconductors (microcrystalline semiconductors, polycrystalline semiconductors, single-crystal semiconductors, or semiconductors with crystalline regions in part) may be used. Using a crystalline semiconductor is preferable because it can suppress the degradation of transistor characteristics.

[0503] The semiconductor layer of the transistor preferably has a metal oxide (also called an oxide semiconductor). In other words, the display panel of this embodiment preferably uses a transistor (hereinafter referred to as an OS transistor) that uses a metal oxide in the channel formation region.

[0504] Examples of crystalline oxide semiconductors include CAAC (c-axis-aligned crystalline)-OS and nc (nanocrystalline)-OS.

[0505] Alternatively, a transistor using silicon as the channel-forming region (Si transistor) may be used. Examples of silicon include single-crystal silicon, polycrystalline silicon, and amorphous silicon. In particular, a transistor having low-temperature polysilicon (LTPS (Low Temperature Poly Silicon)) in the semiconductor layer (hereinafter also referred to as an LTPS transistor) can be used. LTPS transistors have high field-effect mobility and good frequency characteristics.

[0506] By using Si transistors such as LTPS transistors, circuits that need to be driven at high frequencies (e.g., source driver circuits) can be fabricated on the same board as the display unit. This simplifies the external circuits mounted on the display panel, reducing component and mounting costs.

[0507] OS transistors have extremely high field-effect mobility compared to transistors using amorphous silicon. Furthermore, OS transistors exhibit remarkably low source-drain leakage current (hereinafter also referred to as off-current) in the off state, allowing them to retain charge stored in a capacitor connected in series with the transistor for extended periods. Additionally, the application of OS transistors can reduce the power consumption of display panels.

[0508] Furthermore, the off-current value of an OS transistor per 1 μm channel width at room temperature is 1 aA (1 × 10⁻¹⁰). -18 A) Below, 1zA(1×10 -21 A) Less than or equal to 1yA(1×10 -24 A) It can be less than or equal to the following. Note that the off-current value of a Si transistor per 1 μm of channel width at room temperature is 1 fA (1 × 10⁻¹⁰). -15 A) More than 1pA (1×10 -12 A) The answer is as follows. Therefore, it can be said that the off-current of an OS transistor is about 10 orders of magnitude lower than that of a Si transistor.

[0509] Furthermore, to increase the luminescence brightness of the light-emitting device included in the pixel circuit, it is necessary to increase the amount of current flowing through the light-emitting device. To achieve this, it is necessary to increase the source-drain voltage of the drive transistor included in the pixel circuit. Compared to Si transistors, OS transistors have a higher breakdown voltage between the source and drain, so a higher voltage can be applied between the source and drain of an OS transistor. Therefore, by using an OS transistor as the drive transistor included in the pixel circuit, the amount of current flowing through the light-emitting device can be increased, thereby increasing the luminescence brightness of the light-emitting device.

[0510] Furthermore, when the transistor operates in the saturation region, OS transistors exhibit smaller changes in source-drain current in response to changes in gate-source voltage compared to Si transistors. Therefore, by using OS transistors as driving transistors in the pixel circuit, the current flowing between the source and drain can be precisely controlled by changes in gate-source voltage, thereby controlling the amount of current flowing to the light-emitting device. This allows for a wider range of tonal gradations in the pixel circuit.

[0511] Furthermore, in terms of the saturation characteristics of the current flowing when a transistor operates in the saturation region, OS transistors can supply a more stable current (saturation current) than Si transistors, even when the source-drain voltage gradually increases. Therefore, by using OS transistors as driving transistors, a stable current can be supplied to the light-emitting device even if there are variations in the current-voltage characteristics of the EL device. In other words, when operating in the saturation region, the source-drain current remains almost unchanged even when the source-drain voltage is increased, thus stabilizing the luminescence brightness of the light-emitting device.

[0512] As described above, by using OS transistors in the drive transistors included in the pixel circuit, it is possible to achieve "suppression of black level floating," "increase in luminescence brightness," "multi-gradation," and "suppression of variations in light-emitting devices."

[0513] The semiconductor layer preferably comprises, for example, indium, M (where M is one or more selected from gallium, aluminum, silicon, boron, yttrium, tin, copper, vanadium, beryllium, titanium, iron, nickel, germanium, zirconium, molybdenum, lanthanum, cerium, neodymium, hafnium, tantalum, tungsten, and magnesium), and zinc. In particular, M is preferably one or more selected from aluminum, gallium, yttrium, and tin.

[0514] In particular, it is preferable to use an oxide containing indium (In), gallium (Ga), and zinc (Zn) (also written as IGZO) as the semiconductor layer. Alternatively, it is preferable to use an oxide containing indium, tin, and zinc. Alternatively, it is preferable to use an oxide containing indium, gallium, tin, and zinc. Alternatively, it is preferable to use an oxide containing indium (In), aluminum (Al), and zinc (Zn) (also written as IAZO). Alternatively, it is preferable to use an oxide containing indium (In), aluminum (Al), gallium (Ga), and zinc (Zn) (also written as IAGZO).

[0515] When the semiconductor layer is an In-M-Zn oxide, it is preferable that the atomic ratio of In in the In-M-Zn oxide is greater than or equal to the atomic ratio of M. Possible atomic ratios of metal elements in such an In-M-Zn oxide include: In:M:Zn=1:1:1 or near that composition, In:M:Zn=1:1:1.2 or near that composition, In:M:Zn=1:3:2 or near that composition, In:M:Zn=1:3:4 or near that composition, In:M:Zn=2:1:3 or near that composition, In:M:Zn=3:1:2 or near that composition, and In:M:Zn=4:2:3 Examples include compositions near the desired atomic ratio, such as In:M:Zn=4:2:4.1 or near that ratio, In:M:Zn=5:1:3 or near that ratio, In:M:Zn=5:1:6 or near that ratio, In:M:Zn=5:1:7 or near that ratio, In:M:Zn=5:1:8 or near that ratio, In:M:Zn=6:1:6 or near that ratio, In:M:Zn=5:2:5 or near that ratio, etc. Note that "nearby composition" includes a range of ±30% of the desired atomic ratio.

[0516] For example, when describing a composition with an atomic ratio of In:Ga:Zn = 4:2:3 or a similar ratio, it includes cases where, when the atomic ratio of In is 4, the atomic ratio of Ga is between 1 and 3, and the atomic ratio of Zn is between 2 and 4. Also, when describing a composition with an atomic ratio of In:Ga:Zn = 5:1:6 or a similar ratio, it includes cases where, when the atomic ratio of In is 5, the atomic ratio of Ga is greater than 0.1 and 2 or less, and the atomic ratio of Zn is between 5 and 7. Furthermore, when describing a composition with an atomic ratio of In:Ga:Zn = 1:1:1 or a similar ratio, it includes cases where, when the atomic ratio of In is 1, the atomic ratio of Ga is greater than 0.1 and 2 or less, and the atomic ratio of Zn is greater than 0.1 and 2 or less.

[0517] 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.

[0518] All of the transistors in the display unit 162 may be OS transistors, all of the transistors in the display unit 162 may be Si transistors, or some of the transistors in the display unit 162 may be OS transistors and the rest may be Si transistors.

[0519] For example, by using both LTPS transistors and OS transistors in the display unit 162, a display panel with low power consumption and high driving capability can be realized. Furthermore, a configuration combining LTPS transistors and OS transistors is sometimes referred to as LTPO. In a more preferable example, it is preferable to apply OS transistors to transistors that function as switches to control conduction and non-conduction between wiring, and LTPS transistors to transistors that control current.

[0520] For example, one of the transistors in the display unit 162 functions as a transistor for controlling the current flowing to the light-emitting device, and can also be called a drive transistor. One of the source and drain of the drive transistor is electrically connected to the pixel electrode of the light-emitting device. It is preferable to use an LTPS transistor for the drive transistor. This makes it possible to increase the current flowing to the light-emitting device in the pixel circuit.

[0521] On the other hand, the other transistor in the display unit 162 functions as a switch for controlling the selection and deselection of pixels, and can also be called a selection transistor. The gate of the selection transistor is electrically connected to the gate line, and one of the source and drain is electrically connected to the source line (signal line). It is preferable to use an OS transistor for the selection transistor. This makes it possible to maintain the gradation of pixels even when the frame frequency is significantly reduced (e.g., 1 fps or less), and thus power consumption can be reduced by stopping the driver when displaying still images.

[0522] Thus, a display panel according to one aspect of the present invention can combine a high aperture ratio, high resolution, high display quality, and low power consumption.

[0523] Furthermore, one embodiment of the present invention provides a display panel having an OS transistor and a light-emitting device with an MML (metal maskless) structure. This configuration makes it possible to extremely reduce the leakage current that can flow through the transistor and the leakage current that can flow between adjacent light-emitting devices (also called lateral leakage current or side leakage current). With this configuration, when an image is displayed on the display panel, the observer can observe one or more of the following: image sharpness, image clarity, high saturation, and high contrast ratio. Moreover, by providing a configuration in which the leakage current that can flow through the transistor and the lateral leakage current between light-emitting devices are extremely low, it is possible to achieve a display with minimal light leakage that may occur when displaying black.

[0524] Figures 22B and 22C show other examples of transistor configurations.

[0525] Transistors 209 and 210 each have a conductive layer 221 that functions as a gate, an insulating layer 211 that functions as a gate insulating layer, a semiconductor layer 231 having a channel forming region 231i and a pair of low-resistance regions 231n, a conductive layer 222a connected to one of the pair of low-resistance regions 231n, a conductive layer 222b connected to the other of the pair of low-resistance regions 231n, an insulating layer 225 that functions as a gate insulating layer, a conductive layer 223 that functions as a gate, and an insulating layer 215 covering the conductive layer 223. The insulating layer 211 is located between the conductive layer 221 and the channel forming region 231i. The insulating layer 225 is located at least between the conductive layer 223 and the channel forming region 231i. Furthermore, an insulating layer 218 covering the transistor may be provided.

[0526] In the transistor 209 shown in Figure 22B, an example is shown where the insulating layer 225 covers the top and sides of the semiconductor layer 231. The conductive layers 222a and 222b are connected to the low-resistance region 231n through openings provided in the insulating layers 225 and 215, respectively. Of the conductive layers 222a and 222b, one functions as the source and the other as the drain.

[0527] On the other hand, in the transistor 210 shown in Figure 22C, the insulating layer 225 overlaps with the channel formation region 231i of the semiconductor layer 231, but does not overlap with the low-resistance region 231n. For example, the structure shown in Figure 22C can be fabricated by processing the insulating layer 225 using the conductive layer 223 as a mask. In Figure 22C, an insulating layer 215 is provided covering the insulating layer 225 and the conductive layer 223, and the conductive layer 222a and conductive layer 222b are connected to the low-resistance region 231n, respectively, through openings in the insulating layer 215.

[0528] A connection portion 204 is provided in the region 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 242. The conductive layer 166 is shown as an example of a laminated structure consisting of a conductive film obtained by processing the same conductive film as conductive layers 112a, 112b, and 112c, a conductive film obtained by processing the same conductive film as conductive layers 126a, 126b, and 126c, and a conductive film obtained by processing the same conductive film as conductive layers 129a, 129b, and 129c. The conductive layer 166 is exposed on the upper surface of the connection portion 204. This allows the connection portion 204 and FPC 172 to be electrically connected via the connection layer 242.

[0529] It is preferable to provide a light-shielding layer 117 on the surface of the substrate 152 that faces the substrate 151. The light-shielding layer 117 can be provided between adjacent light-emitting devices, at connection points 140, and in circuits 164, etc. In addition, various optical components can be arranged on the outside of the substrate 152.

[0530] Materials that can be used for substrate 120 can be applied to substrate 151 and substrate 152, respectively.

[0531] As the adhesive layer 142, a material that can be used for the resin layer 122 can be applied.

[0532] As the connecting layer 242, an anisotropic conductive film (ACF), an anisotropic conductive paste (ACP), etc., can be used.

[0533] [Display Panel 100H] The display panel 100H shown in Figure 23A differs from the display panel 100G mainly in that it is a bottom-emission type display panel.

[0534] The light emitted by the light-emitting device is projected onto the substrate 151. It is preferable to use a material with high transparency to visible light for the substrate 151. On the other hand, the light transmittance of the material used for the substrate 152 is not a requirement.

[0535] It is preferable to form a light-shielding layer 117 between the substrate 151 and the transistor 201, and between the substrate 151 and the transistor 205. Figure 23A shows an example in which a light-shielding layer 117 is provided on the substrate 151, an insulating layer 153 is provided on the light-shielding layer 117, and transistors 201, 205, etc. are provided on the insulating layer 153.

[0536] The light-emitting device 130R includes a conductive layer 112a, a conductive layer 126a on the conductive layer 112a, and a conductive layer 129a on the conductive layer 126a.

[0537] The light-emitting device 130G has a conductive layer 112b, a conductive layer 126b on the conductive layer 112b, and a conductive layer 129b on the conductive layer 126b.

[0538] The conductive layers 112a, 112b, 126a, 126b, 129a, and 129b are made of materials with high transmittance to visible light. It is preferable to use a material that reflects visible light for the common electrode 115.

[0539] Furthermore, while Figures 22A and 23A show examples where the upper surface of layer 128 has a flat shape, the shape of layer 128 is not particularly limited. Figures 23B to 23D show modified examples of layer 128.

[0540] As shown in Figures 23B and 23D, the upper surface of layer 128 can be configured to have a shape in which the center and its vicinity are recessed in a cross-sectional view, that is, a shape having a concave curved surface.

[0541] Furthermore, as shown in Figure 23C, the upper surface of layer 128 can be configured to have a shape that bulges in the center and its vicinity in a cross-sectional view, that is, a shape with a convex curved surface.

[0542] Furthermore, the upper surface of layer 128 may have one or both of a convex and a concave surface. Also, the number of convex and concave surfaces on the upper surface of layer 128 is not limited and can be one or more.

[0543] Furthermore, the height of the top surface of layer 128 and the height of the top surface of the conductive layer 112a may be the same or approximately the same, or they may be different from each other. For example, the height of the top surface of layer 128 may be lower or higher than the height of the top surface of the conductive layer 112a.

[0544] Furthermore, Figure 23B can be seen as an example in which layer 128 is housed inside a recess formed in the conductive layer 112a. On the other hand, as shown in Figure 23D, layer 128 may exist outside the recess formed in the conductive layer 112a, that is, the width of the upper surface of layer 128 may be wider than that of the recess.

[0545] [Display Panel 100J] The display panel 100J shown in Figure 24 differs from the display panel 100G mainly in that it has a light-receiving device 150.

[0546] The light-receiving device 150 has a conductive layer 112d, a conductive layer 126d on the conductive layer 112d, and a conductive layer 129d on the conductive layer 126d.

[0547] The conductive layer 112d is connected to the conductive layer 222b of the transistor 205 through an opening provided in the insulating layer 214.

[0548] The top and side surfaces of conductive layer 126d and conductive layer 129d are covered by a fourth layer 113d. The fourth layer 113d has at least an active layer.

[0549] The sides of the fourth layer 113d are covered by insulating layers 125 and 127. A mask layer 118d is located between the fourth layer 113d and the insulating layer 125. A common layer 114 is provided on the fourth layer 113d and the insulating layers 125 and 127, and a common electrode 115 is provided on the common layer 114. The common layer 114 is a continuous film provided in common to both the light-receiving device and the light-emitting device.

[0550] The display panel 100J can be configured with either the pixel layout shown in Figure 4A, described in Embodiment 1, or the pixel layouts shown in Figures 13A to 13D, described in Embodiment 2. The light-receiving device 150 can be provided in at least one of the sub-pixels PS, sub-pixel X1, and sub-pixel X2. For further details of the display panel having the light-receiving device, refer to Embodiment 1.

[0551] This embodiment can be combined with other embodiments as appropriate.

[0552] (Embodiment 4) This embodiment describes an example of a transistor configuration that can be applied to a display panel according to one aspect of the present invention. In particular, it describes a case in which a transistor containing silicon is used as the semiconductor in which the channel is formed.

[0553] One aspect of the present invention is a display panel having a light-emitting device and a pixel circuit. The display panel can be a full-color display panel by having, for example, three types of light-emitting devices that emit red (R), green (G), or blue (B) light, respectively.

[0554] It is preferable to use transistors in which the semiconductor layer in which the channel is formed is silicon for all transistors included in the pixel circuit that drives the light-emitting device. Examples of silicon include single-crystal silicon, polycrystalline silicon, and amorphous silicon. In particular, it is preferable to use transistors in which the semiconductor layer is low-temperature polysilicon (LTPS (Low Temperature Poly Silicon)) (hereinafter also referred to as LTPS transistors). LTPS transistors have high field-effect mobility and good frequency characteristics.

[0555] By using silicon-based transistors such as LTPS transistors, circuits that need to be driven at high frequencies (e.g., source driver circuits) can be fabricated on the same board as the display unit. This simplifies the external circuits mounted on the display panel, reducing component and mounting costs.

[0556] Furthermore, it is preferable to use a transistor (hereinafter also called an OS transistor) in which a metal oxide (hereinafter also called an oxide semiconductor) is used as the semiconductor in which the channel is formed. Compared to transistors using amorphous silicon, OS transistors have extremely high field-effect mobility. In addition, OS transistors have a remarkably small source-drain leakage current (hereinafter also called an off-current) in the off state, and can retain the charge stored in a capacitor connected in series with the transistor for a long period of time. Moreover, by applying OS transistors, the power consumption of the display panel can be reduced.

[0557] By using LTPS transistors for some of the transistors in the pixel circuit and OS transistors for others, a display panel with low power consumption and high driving capability can be realized. A more preferable example is to apply OS transistors to transistors that function as switches to control conduction and non-conductivity between wiring, and LTPS transistors to transistors that control current.

[0558] For example, one of the transistors provided in the pixel circuit functions as a transistor for controlling the current flowing to the light-emitting device, and can also be called a drive transistor. One of the source and drain of the drive transistor is electrically connected to the pixel electrode of the light-emitting device. It is preferable to use an LTPS transistor for this drive transistor. This makes it possible to increase the current flowing to the light-emitting device in the pixel circuit.

[0559] On the other hand, another transistor provided in the pixel circuit functions as a switch to control the selection and deselection of pixels, and can also be called a selection transistor. The gate of the selection transistor is electrically connected to the gate line, and one of the source and drain is electrically connected to the source line (signal line). It is preferable to use an OS transistor for the selection transistor. This makes it possible to maintain the gradation of pixels even when the frame frequency is significantly reduced (e.g., 1 fps or less), and thus power consumption can be reduced by stopping the driver when displaying still images.

[0560] Below, we will explain more specific configuration examples with reference to the drawings.

[0561] [Example of display panel configuration] Figure 25A shows a block diagram of the display panel 400. The display panel 400 includes a display unit 404, a drive circuit unit 402, a drive circuit unit 403, and the like.

[0562] The display unit 404 has a plurality of pixels 430 arranged in a matrix. Each pixel 430 has sub-pixels 405R, 405G, and 405B. Each of the sub-pixels 405R, 405G, and 405B has a light-emitting device that functions as a display device.

[0563] Pixel 430 is electrically connected to wiring GL, wiring SLR, wiring SLG, and wiring SLB. Wiring SLR, wiring SLG, and wiring SLB are each electrically connected to drive circuit unit 402. Wiring GL is electrically connected to drive circuit unit 403. Drive circuit unit 402 functions as a source line drive circuit (also called a source driver), and drive circuit unit 403 functions as a gate line drive circuit (also called a gate driver). Wiring GL functions as a gate line, and wiring SLR, wiring SLG, and wiring SLB each function as source lines.

[0564] Sub-pixel 405R has a light-emitting device that emits red light. Sub-pixel 405G has a light-emitting device that emits green light. Sub-pixel 405B has a light-emitting device that emits blue light. This allows the display panel 400 to display in full color. Pixel 430 may also have sub-pixels that emit light from light-emitting devices of other colors. For example, in addition to the three sub-pixels described above, pixel 430 may have a sub-pixel that emits white light from a light-emitting device, or a sub-pixel that emits yellow light, and so on.

[0565] Wiring GL is electrically connected to sub-pixels 405R, 405G, and 405B, which are arranged in the row direction (the direction in which wiring GL extends). Wiring SLR, SLG, and SLB are electrically connected to sub-pixels 405R, 405G, or 405B (not shown), respectively, which are arranged in the column direction (the direction in which wiring SLR, etc. extends).

[0566] [Example of pixel circuit configuration] Figure 25B shows an example of a circuit diagram for a pixel 405 that can be applied to the sub-pixels 405R, 405G, and 405B described above. Pixel 405 has transistors M1, M2, M3, capacitor C1, and light-emitting device EL. Wiring GL and wiring SL are electrically connected to pixel 405. Wiring SL corresponds to one of the wirings SLR, SLG, and SLB shown in Figure 25A.

[0567] Transistor M1 has its gate electrically connected to wiring GL, one of its source and drain electrically connected to wiring SL, and the other of its source and drain electrically connected to one electrode of capacitor C1 and the gate of transistor M2. Transistor M2 has one of its source and drain electrically connected to wiring AL, and the other of its source and drain electrically connected to one electrode of light-emitting device EL, the other electrode of capacitor C1, and one of its source and drain. Transistor M3 has its gate electrically connected to wiring GL, and the other of its source and drain electrically connected to wiring RL. Light-emitting device EL has its other electrode electrically connected to wiring CL.

[0568] A data potential D is applied to wiring SL. A selection signal is applied to wiring GL. This selection signal includes a potential that makes the transistor conduct and a potential that makes it non-conductive.

[0569] A reset potential is applied to wiring RL. An anode potential is applied to wiring AL. A cathode potential is applied to wiring CL. In pixel 405, the anode potential is set to a higher potential than the cathode potential. The reset potential applied to wiring RL can be set such that the potential difference between the reset potential and the cathode potential is smaller than the threshold voltage of the light-emitting device EL. The reset potential can be set to a potential higher than the cathode potential, the same potential as the cathode potential, or lower than the cathode potential.

[0570] Transistors M1 and M3 function as switches. Transistor M2 functions as a transistor for controlling the current flowing to the light-emitting device EL. For example, it can be said that transistor M1 functions as a selector transistor and transistor M2 functions as a drive transistor.

[0571] Here, it is preferable to apply LTPS transistors to all of transistors M1 through M3. Alternatively, it is preferable to apply OS transistors to transistors M1 and M3, and an LTPS transistor to transistor M2.

[0572] Alternatively, OS transistors may be applied to all of transistors M1 through M3. In this case, one or more of the transistors in the drive circuit section 402 and the drive circuit section 403 may be LTPS transistors, and the other transistors may be OS transistors. For example, OS transistors may be applied to the transistors provided in the display section 404, and LTPS transistors may be applied to the transistors provided in the drive circuit section 402 and the drive circuit section 403.

[0573] As an OS transistor, a transistor using an oxide semiconductor in the semiconductor layer where the channel is formed can be used. The semiconductor layer preferably contains, for example, indium, M (where M is one or more selected from gallium, aluminum, silicon, boron, yttrium, tin, copper, vanadium, beryllium, titanium, iron, nickel, germanium, zirconium, molybdenum, lanthanum, cerium, neodymium, hafnium, tantalum, tungsten, and magnesium), and zinc. In particular, it is preferable that M is one or more selected from aluminum, gallium, yttrium, and tin. In particular, it is preferable to use an oxide containing indium, gallium, and zinc (also written as IGZO) as the semiconductor layer of the OS transistor. Alternatively, it is preferable to use an oxide containing indium, tin, and zinc. Alternatively, it is preferable to use an oxide containing indium, gallium, tin, and zinc.

[0574] Transistors using oxide semiconductors, which have a wider bandgap and lower carrier density than silicon, can achieve extremely low off-currents. Therefore, this low off-current allows the charge stored in a capacitor connected in series with the transistor to be retained for extended periods. For this reason, it is preferable to use transistors made of oxide semiconductors for transistors M1 and M3, which are connected in series with capacitor C1. By using transistors with oxide semiconductors as transistors M1 and M3, it is possible to prevent the charge held in capacitor C1 from leaking through transistor M1 or M3. Furthermore, because the charge held in capacitor C1 can be retained for extended periods, it becomes possible to display still images for extended periods without rewriting the data in pixel 405.

[0575] Note that in Figure 25B, the transistor is shown as an n-channel type transistor, but a p-channel type transistor can also be used.

[0576] Furthermore, it is preferable that each transistor in pixel 405 be formed in a row on the same substrate.

[0577] As the transistor in pixel 405, a transistor having a pair of gates that overlap across a semiconductor layer can be applied.

[0578] In a transistor having a pair of gates, configuring the pair of gates to be electrically connected to each other and given the same potential offers advantages such as increased on-current and improved saturation characteristics. Alternatively, one of the pair of gates may be given a potential that controls the transistor's threshold voltage. Furthermore, providing a constant potential to one of the pair of gates can improve the stability of the transistor's electrical characteristics. For example, one of the transistor's gates may be electrically connected to a wiring to which a constant potential is provided, or it may be electrically connected to its own source or drain.

[0579] The pixel 405 shown in Figure 25C is an example where transistors M1 and M3 each have a pair of gates. The pair of gates of transistors M1 and M3 are electrically connected. This configuration shortens the data writing time to the pixel 405.

[0580] Pixel 405, shown in Figure 25D, is an example in which a transistor with a pair of gates is applied to transistor M2, in addition to transistors M1 and M3. In transistor M2, the pair of gates are electrically connected. By applying such a transistor to transistor M2, the saturation characteristics are improved, making it easier to control the luminescence brightness of the light-emitting device EL and improving the display quality.

[0581] [Example of transistor configuration] The following describes examples of transistor cross-sectional configurations that can be applied to the above-mentioned display panel.

[0582] [Configuration Example 1] Figure 26A is a cross-sectional view including transistor 410.

[0583] Transistor 410 is provided on substrate 401 and is a transistor in which polycrystalline silicon is applied to the semiconductor layer. For example, transistor 410 corresponds to transistor M2 of pixel 405. That is, Figure 26A is an example in which one of the source and drain of transistor 410 is electrically connected to the conductive layer 431 of the light-emitting device.

[0584] The transistor 410 has a semiconductor layer 411, an insulating layer 412, a conductive layer 413, etc. The semiconductor layer 411 has a channel-forming region 411i and a low-resistance region 411n. The semiconductor layer 411 is made of silicon. Preferably, the semiconductor layer 411 is made of polycrystalline silicon. A portion of the insulating layer 412 functions as a gate insulating layer. A portion of the conductive layer 413 functions as a gate electrode.

[0585] Furthermore, the semiconductor layer 411 may also be configured to include a metal oxide (also called an oxide semiconductor) that exhibits semiconductor properties. In this case, the transistor 410 can be called an OS transistor.

[0586] The low-resistance region 411n is a region containing impurity elements. For example, if transistor 410 is an n-channel type transistor, phosphorus, arsenic, etc., can be added to the low-resistance region 411n. On the other hand, if it is a p-channel type transistor, boron, aluminum, etc., can be added to the low-resistance region 411n. Furthermore, in order to control the threshold voltage of transistor 410, the aforementioned impurities may also be added to the channel formation region 411i.

[0587] An insulating layer 421 is provided on the substrate 401. The semiconductor layer 411 is provided on the insulating layer 421. The insulating layer 412 is provided covering the semiconductor layer 411 and the insulating layer 421. The conductive layer 413 is provided on the insulating layer 412 in a position overlapping with the semiconductor layer 411.

[0588] Furthermore, an insulating layer 422 is provided covering the conductive layer 413 and the insulating layer 412. Conductive layers 414a and 414b are provided on the insulating layer 422. Conductive layers 414a and 414b are electrically connected to the low-resistance region 411n at openings provided in the insulating layers 422 and 412. A portion of the conductive layer 414a functions as one of the source electrode and drain electrode, and a portion of the conductive layer 414b functions as the other of the source electrode and drain electrode. In addition, an insulating layer 423 is provided covering the conductive layer 414a, conductive layer 414b, and insulating layer 422.

[0589] A conductive layer 431, which functions as a pixel electrode, is provided on the insulating layer 423. The conductive layer 431 is provided on the insulating layer 423 and is electrically connected to the conductive layer 414b at an opening provided in the insulating layer 423. Although not shown here, an EL layer and a common electrode can be laminated on the conductive layer 431.

[0590] [Configuration Example 2] Figure 26B shows a transistor 410a having a pair of gate electrodes. The transistor 410a shown in Figure 26B differs from that in Figure 26A mainly in that it has a conductive layer 415 and an insulating layer 416.

[0591] The conductive layer 415 is provided on the insulating layer 421. Furthermore, an insulating layer 416 is provided covering the conductive layer 415 and the insulating layer 421. The semiconductor layer 411 is provided such that at least the channel-forming region 411i overlaps with the conductive layer 415 via the insulating layer 416.

[0592] In the transistor 410a shown in Figure 26B, a portion of the conductive layer 413 functions as a first gate electrode, and a portion of the conductive layer 415 functions as a second gate electrode. At the same time, a portion of the insulating layer 412 functions as a first gate insulating layer, and a portion of the insulating layer 416 functions as a second gate insulating layer.

[0593] Here, when electrically connecting the first gate electrode and the second gate electrode, the conductive layer 413 and the conductive layer 415 may be electrically connected through openings provided in the insulating layer 412 and the insulating layer 416 in a region not shown. Also, when electrically connecting the second gate electrode to the source or drain, the conductive layer 414a or conductive layer 414b and the conductive layer 415 may be electrically connected through openings provided in the insulating layer 422, the insulating layer 412, and the insulating layer 416 in a region not shown.

[0594] When LTPS transistors are applied to all transistors constituting pixel 405, transistor 410 as exemplified in Figure 26A, or transistor 410a as exemplified in Figure 26B, can be applied. In this case, transistor 410a may be used for all transistors constituting pixel 405, transistor 410 may be applied to all transistors, or transistor 410a and transistor 410 may be used in combination.

[0595] [Configuration Example 3] The following describes an example of a configuration that includes both transistors with silicon semiconductor layers and transistors with metal oxide semiconductor layers.

[0596] Figure 26C shows a schematic cross-sectional view including transistors 410a and 450.

[0597] For transistor 410a, the above configuration example 1 can be used. Although an example using transistor 410a is shown here, a configuration with transistor 410 and transistor 450 is also possible, or a configuration with all of transistors 410, 410a, and 450 is also possible.

[0598] Transistor 450 is a transistor in which a metal oxide is applied to the semiconductor layer. The configuration shown in Figure 26C is an example in which, for example, transistor 450 corresponds to transistor M1 of pixel 405 and transistor 410a corresponds to transistor M2. That is, Figure 26C is an example in which one of the source and drain of transistor 410a is electrically connected to the conductive layer 431.

[0599] Figure 26C also shows an example where transistor 450 has a pair of gates.

[0600] The transistor 450 has a conductive layer 455, an insulating layer 422, a semiconductor layer 451, an insulating layer 452, a conductive layer 453, etc. A portion of the conductive layer 453 functions as the first gate of the transistor 450, and a portion of the conductive layer 455 functions as the second gate of the transistor 450. At this time, a portion of the insulating layer 452 functions as the first gate insulating layer of the transistor 450, and a portion of the insulating layer 422 functions as the second gate insulating layer of the transistor 450.

[0601] The conductive layer 455 is provided on the insulating layer 412. The insulating layer 422 covers the conductive layer 455. The semiconductor layer 451 is provided on the insulating layer 422. The insulating layer 452 covers the semiconductor layer 451 and the insulating layer 422. The conductive layer 453 is provided on the insulating layer 452 and has a region that overlaps with the semiconductor layer 451 and the conductive layer 455.

[0602] Furthermore, an insulating layer 426 is provided covering the insulating layer 452 and the conductive layer 453. Conductive layers 454a and 454b are provided on the insulating layer 426. Conductive layers 454a and 454b are electrically connected to the semiconductor layer 451 at openings provided in the insulating layer 426 and the insulating layer 452. A portion of the conductive layer 454a functions as one of the source electrode and drain electrode, and a portion of the conductive layer 454b functions as the other of the source electrode and drain electrode. In addition, an insulating layer 423 is provided covering the conductive layer 454a, the conductive layer 454b, and the insulating layer 426.

[0603] Here, it is preferable that the conductive layers 414a and 414b, which are electrically connected to the transistor 410a, are formed by processing the same conductive film as conductive layers 454a and 454b. Figure 26C shows a configuration in which conductive layers 414a, 414b, 454a, and 454b are formed on the same plane (i.e., in contact with the upper surface of the insulating layer 426) and contain the same metal element. In this case, conductive layers 414a and 414b are electrically connected to the low-resistance region 411n through openings provided in the insulating layer 426, insulating layer 452, insulating layer 422, and insulating layer 412. This is preferable because it simplifies the manufacturing process.

[0604] Furthermore, it is preferable that the conductive layer 413, which functions as the first gate electrode of transistor 410a, and the conductive layer 455, which functions as the second gate electrode of transistor 450, are formed by processing the same conductive film. Figure 26C shows a configuration in which the conductive layer 413 and the conductive layer 455 are formed on the same plane (i.e., in contact with the upper surface of the insulating layer 412) and contain the same metal element. This is preferable because it simplifies the manufacturing process.

[0605] In Figure 26C, the insulating layer 452, which functions as the first gate insulating layer of the transistor 450, is configured to cover the edge of the semiconductor layer 451. However, as shown in Figure 26D, the insulating layer 452 may be processed so that its upper surface shape matches or is approximately the same as that of the conductive layer 453.

[0606] In this specification, "approximately matching top surface shapes" means that at least a portion of the contours overlap between stacked layers. For example, this includes cases where the upper and lower layers are processed with the same mask pattern, or partially with the same mask pattern. However, strictly speaking, the contours may not overlap, and the upper layer may be located inside the lower layer, or the upper layer may be located outside the lower layer; in this case, too, it is said that the "top surface shapes are approximately matching."

[0607] In this example, transistor 410a corresponds to transistor M2 and is electrically connected to the pixel electrode, but this is not the only example. For example, transistor 450 or transistor 450a may correspond to transistor M2. In this case, transistor 410a corresponds to transistor M1, transistor M3, or another transistor.

[0608] This embodiment can be combined with other embodiments as appropriate.

[0609] (Embodiment 5) This embodiment describes a light-emitting device that can be used in a display panel according to one aspect of the present invention.

[0610] As shown in Figure 27A, the light-emitting device has an EL layer 786 between a pair of electrodes (lower electrode 772, upper electrode 788). The EL layer 786 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).

[0611] A configuration having a layer 4420, an emissive layer 4411, and a layer 4430 provided between a pair of electrodes can function as a single emissive unit, and in this specification, the configuration shown in Figure 27A is referred to as a single structure.

[0612] Furthermore, Figure 27B shows a modified example of the EL layer 786 of the light-emitting device shown in Figure 27A. Specifically, the light-emitting device shown in Figure 27B includes a layer 4431 on the lower electrode 772, a layer 4432 on layer 4431, a light-emitting layer 4411 on layer 4432, a layer 4421 on the light-emitting layer 4411, a layer 4422 on layer 4421, and an upper electrode 788 on layer 4422. For example, when the lower electrode 772 is the anode and the upper electrode 788 is the cathode, layer 4431 functions as a hole injection layer, layer 4432 functions as a hole transport layer, layer 4421 functions as an electron transport layer, and layer 4422 functions as an electron injection layer. Alternatively, if the lower electrode 772 is used as the cathode and the upper electrode 788 as the anode, layer 4431 functions as an electron injection layer, layer 4432 functions as an electron transport layer, layer 4421 functions as a hole transport layer, and layer 4422 functions as a hole injection layer. With such a layer structure, it is possible to efficiently inject carriers into the light-emitting layer 4411 and increase the efficiency of carrier recombination within the light-emitting layer 4411.

[0613] Furthermore, as shown in Figures 27C and 27D, a configuration in which multiple light-emitting layers (light-emitting layers 4411, 4412, and 4413) are provided between layer 4420 and layer 4430 is also a variation of the single structure.

[0614] Furthermore, as shown in Figures 27E and 27F, a configuration in which multiple light-emitting units (EL layer 786a, EL layer 786b) are connected in series via a charge generation layer 4440 is referred to as a tandem structure in this specification. The tandem structure may also be called a stacked structure. By using a tandem structure, a light-emitting device capable of high-brightness emission can be achieved.

[0615] In Figures 27C and 27D, the light-emitting layers 4411, 4412, and 4413 may be made of light-emitting materials that emit light of the same color, or even the same light-emitting material may be used. For example, light-emitting materials that emit blue light may be used for the light-emitting layers 4411, 4412, and 4413. A color conversion layer may be provided as layer 785 as shown in Figure 27D.

[0616] Furthermore, light-emitting materials that emit light of different colors may be used for light-emitting layers 4411, 4412, and 4413. When the light emitted by light-emitting layers 4411, 4412, and 4413 are complementary colors, white light emission is obtained. A color filter (also called a colored layer) may be provided as layer 785 as shown in Figure 27D. By passing white light through the color filter, light of a desired color can be obtained.

[0617] Furthermore, in Figures 27E and 27F, the light-emitting layer 4411 and the light-emitting layer 4412 may be made of light-emitting materials that emit light of the same color, or they may be made of the same light-emitting material. Alternatively, the light-emitting layer 4411 and the light-emitting layer 4412 may be made of light-emitting materials that emit light of different colors. When the light emitted by the light-emitting layer 4411 and the light emitted by the light-emitting layer 4412 are complementary colors, white light emission is obtained. Figure 27F shows an example in which an additional layer 785 is provided. As layer 785, one or both of a color conversion layer and a color filter (coloring layer) can be used.

[0618] Furthermore, in Figures 27C, 27D, 27E, and 27F, as shown in Figure 27B, layer 4420 and layer 4430 may be a laminated structure consisting of two or more layers.

[0619] A structure in which each light-emitting device produces a different light-emitting color (for example, blue (B), green (G), and red (R)) is sometimes called an SBS (Side By Side) structure.

[0620] The light-emitting color of the light-emitting device can be red, green, blue, cyan, magenta, yellow, or white, depending on the material that makes up the EL layer 786. Furthermore, the color purity can be further enhanced by adding a microcavity structure to the light-emitting device.

[0621] A light-emitting device 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, a light-emitting device that emits white light as a whole can be obtained. The same applies to light-emitting devices that have three or more light-emitting layers.

[0622] 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), and O (orange). Alternatively, it is preferable to have two or more light-emitting materials, and for each light-emitting material to emit light that contains spectral components of two or more colors from R, G, and B.

[0623] This embodiment can be combined with other embodiments as appropriate.

[0624] (Embodiment 6) In this embodiment, an electronic device according to one aspect of the present invention will be described with reference to Figures 28 to 30.

[0625] The electronic device of this embodiment has a display panel according to one aspect of the present invention in its display unit. The display panel according to one aspect of the present invention is easily made high-definition and high-resolution, and can achieve high display quality. Therefore, it can be used in the display units of various electronic devices.

[0626] Examples of electronic devices include television sets, desktop or notebook personal computers, computer monitors, digital signage, and large game machines such as pachinko machines, as well as other electronic devices with relatively large screens, digital cameras, digital video cameras, digital photo frames, mobile phones, portable game consoles, personal digital assistants, and audio playback devices.

[0627] In particular, a display panel according to one embodiment of the present invention can be used suitably in electronic devices having a relatively small display area because it can increase the resolution. Examples of such electronic devices include wristwatch-type and bracelet-type information terminals (wearable devices), as well as wearable devices that can be worn on the head, such as VR devices such as head-mounted displays, AR devices such as glasses, and MR devices.

[0628] A display panel according to one embodiment of the present invention preferably has an extremely high resolution such as HD (1280 x 720 pixels), FHD (1920 x 1080 pixels), WQHD (2560 x 1440 pixels), WQXGA (2560 x 1600 pixels), 4K (3840 x 2160 pixels), or 8K (7680 x 4320 pixels). In particular, a resolution of 4K, 8K, or higher is preferred. Furthermore, the pixel density (resolution) of the display panel according to one embodiment of the present invention is preferably 100 ppi or more, preferably 300 ppi or more, more preferably 500 ppi or more, more preferably 1000 ppi or more, more preferably 2000 ppi or more, more preferably 3000 ppi or more, more preferably 5000 ppi or more, and even more preferably 7000 ppi or more. By using a display panel having either high resolution or high detail, or both, it becomes possible to enhance the sense of presence and depth in personal electronic devices such as portable or home-use devices. Furthermore, there are no particular limitations on the aspect ratio of the display panel in one embodiment of the present invention. For example, the display panel can support various aspect ratios such as 1:1 (square), 4:3, 16:9, and 16:10.

[0629] The electronic device of this embodiment may have sensors (including those with the function of measuring force, displacement, position, velocity, acceleration, angular velocity, rotational speed, distance, light, liquid, magnetism, temperature, chemical substances, sound, time, hardness, electric field, current, voltage, power, radiation, flow rate, humidity, gradient, vibration, odor, or infrared radiation).

[0630] The electronic device of this embodiment can have a variety of functions. For example, it can have a function to display various information (still images, videos, text images, etc.) on the display unit, a touch panel function, a function to display a calendar, date or time, a function to execute various software (programs), a wireless communication function, a function to read programs or data recorded on a recording medium, and so on.

[0631] Figures 28A to 28D illustrate an example of a wearable device that can be worn on the head. These wearable devices have the function of displaying AR content, or the function of displaying VR content, or both. In addition to AR and VR, these wearable devices may also have the function of displaying SR or MR content. By having an electronic device that has the function of displaying at least one of the following content types, such as AR, VR, SR, and MR, it is possible to enhance the user's sense of immersion.

[0632] The electronic device 700A shown in Figure 28A and the electronic device 700B shown in Figure 28B each include a pair of display panels 751, a pair of housings 721, a communication unit (not shown), a pair of mounting units 723, a control unit (not shown), an imaging unit (not shown), a pair of optical members 753, a frame 757, and a pair of nose pads 758.

[0633] A display panel according to one embodiment of the present invention can be applied to the display panel 751. Therefore, an electronic device capable of displaying extremely high resolution can be created.

[0634] Electronic devices 700A and 700B can project an image displayed on the display panel 751 onto the display area 756 of the optical element 753. Because the optical element 753 is translucent, the user can see the image displayed on the display area superimposed on the transmitted image visible through the optical element 753. Therefore, electronic devices 700A and 700B are electronic devices capable of AR display.

[0635] Electronic devices 700A and 700B may be equipped with cameras capable of capturing images of the area in front of them as imaging units. Furthermore, electronic devices 700A and 700B may each be equipped with acceleration sensors such as gyro sensors to detect the orientation of the user's head and display an image corresponding to that orientation in the display area 756.

[0636] The communications unit has a wireless communication device, which can supply video signals and the like. Alternatively, instead of the wireless communication device, or in addition to the wireless communication device, it may be equipped with a connector to which a cable supplying video signals and power potential can be connected.

[0637] Furthermore, electronic devices 700A and 700B are equipped with batteries that can be charged wirelessly, wired, or both.

[0638] The housing 721 may be equipped with a touch sensor module. The touch sensor module has the function of detecting when the outer surface of the housing 721 is touched. The touch sensor module can detect the user's tap or slide operations and perform various processes. For example, a tap operation can be used to pause or resume the video, and a slide operation can be used to fast forward or rewind. Furthermore, by providing a touch sensor module in each of the two housings 721, the range of operations can be expanded.

[0639] Various types of touch sensors can be applied to the touch sensor module. For example, various methods such as capacitive, resistive, infrared, electromagnetic induction, surface acoustic wave, and optical sensors can be used. In particular, it is preferable to apply a capacitive or optical sensor to the touch sensor module.

[0640] When using an optical touch sensor, a photoelectric conversion device (also called a photoelectric element) can be used as the light-receiving device (also called a photoelectric element). The active layer of the photoelectric conversion device can be made of either an inorganic semiconductor or an organic semiconductor, or both.

[0641] The electronic device 800A shown in Figure 28C and the electronic device 800B shown in Figure 28D each include a pair of display units 820, a housing 821, a communication unit 822, a pair of mounting units 823, a control unit 824, a pair of imaging units 825, and a pair of lenses 832.

[0642] A display panel according to one embodiment of the present invention can be applied to the display unit 820. Therefore, an electronic device capable of displaying extremely high resolution can be created. This allows the user to experience a high level of immersion.

[0643] The display unit 820 is located inside the housing 821, in a position where it can be seen through the lens 832. Furthermore, by displaying different images on a pair of display units 820, a three-dimensional display using parallax can also be performed.

[0644] Electronic devices 800A and 800B can be described as electronic devices for VR. A user wearing either electronic device 800A or electronic device 800B can view the image displayed on the display unit 820 through the lens 832.

[0645] It is preferable that electronic devices 800A and 800B each have a mechanism that allows adjustment of the left and right positions of the lens 832 and the display unit 820 so that they are in the optimal position according to the user's eye position. It is also preferable that they have a mechanism that adjusts the focus by changing the distance between the lens 832 and the display unit 820.

[0646] The attachment portion 823 allows the user to attach the electronic device 800A or 800B to their head. While Figure 28C and other figures illustrate the attachment portion as resembling the temples (or joints) of eyeglasses, it is not limited to this shape. The attachment portion 823 only needs to be wearable by the user; for example, it may be helmet-shaped or band-shaped.

[0647] The imaging unit 825 has the function of acquiring external information. The data acquired by the imaging unit 825 can be output to the display unit 820. An image sensor can be used in the imaging unit 825. In addition, multiple cameras may be provided to accommodate multiple angles of view, such as telephoto and wide-angle.

[0648] Although an example with an imaging unit 825 is shown here, any distance measuring sensor (hereinafter also referred to as a detection unit) capable of measuring the distance to an object can be provided. In other words, the imaging unit 825 is one form of a detection unit. As the detection unit, for example, an image sensor or a distance image sensor such as LiDAR (Light Detection and Ranging) can be used. By using the image obtained by the camera and the image obtained by the distance image sensor, more information can be acquired, enabling more accurate gesture control.

[0649] The electronic device 800A may have a vibration mechanism that functions as a bone conduction earphone. For example, a configuration having such a vibration mechanism can be applied to one or more of the display unit 820, housing 821, and mounting unit 823. This allows users to enjoy video and audio simply by wearing the electronic device 800A, without needing separate audio equipment such as headphones, earphones, or speakers.

[0650] Electronic devices 800A and 800B may each have input terminals. Cables can be connected to the input terminals to supply video signals from video output devices, etc., and power for charging batteries provided in the electronic devices.

[0651] An electronic device according to one aspect of the present invention may have a function for wireless communication with an earphone 750. The earphone 750 has a communication unit (not shown) and has a wireless communication function. The earphone 750 can receive information (e.g., voice data) from the electronic device through its wireless communication function. For example, the electronic device 700A shown in Figure 28A has a function for transmitting information to the earphone 750 through its wireless communication function. Also, for example, the electronic device 800A shown in Figure 28C has a function for transmitting information to the earphone 750 through its wireless communication function.

[0652] Furthermore, the electronic device may have an earphone section. The electronic device 700B shown in Figure 28B has an earphone section 727. For example, the earphone section 727 and the control unit can be connected to each other by wire. Part of the wiring connecting the earphone section 727 and the control unit may be located inside the housing 721 or the mounting section 723.

[0653] Similarly, the electronic device 800B shown in Figure 28D has an earphone unit 827. For example, the earphone unit 827 and the control unit 824 can be connected to each other by wire. Part of the wiring connecting the earphone unit 827 and the control unit 824 may be located inside the housing 821 or the mounting unit 823. Also, the earphone unit 827 and the mounting unit 823 may have magnets. This allows the earphone unit 827 to be fixed to the mounting unit 823 by magnetic force, which is preferable as it facilitates storage.

[0654] Furthermore, the electronic device may have an audio output terminal to which earphones or headphones can be connected. The electronic device may also have an audio input terminal and / or an audio input mechanism. For example, a sound-collecting device such as a microphone can be used as the audio input mechanism. By having an audio input mechanism, the electronic device may be given the function of a so-called headset.

[0655] Thus, as one embodiment of the present invention, both eyeglass-type (electronic devices 700A and 700B, etc.) and goggle-type (electronic devices 800A and 800B, etc.) are preferred as electronic devices.

[0656] Furthermore, an electronic device according to one aspect of the present invention can transmit information to earphones via wired or wireless means.

[0657] The electronic device 6500 shown in Figure 29A is a portable information terminal that can be used as a smartphone.

[0658] The electronic device 6500 includes a housing 6501, a display unit 6502, a power button 6503, a button 6504, a speaker 6505, a microphone 6506, a camera 6507, and a light source 6508, etc. The display unit 6502 has a touch panel function.

[0659] A display panel according to one embodiment of the present invention can be applied to the display unit 6502.

[0660] Figure 29B is a schematic cross-sectional view of the housing 6501, including the end on the microphone 6506 side.

[0661] A light-transmitting protective member 6510 is provided on the display side of the housing 6501, and the display panel 6511, optical member 6512, touch sensor panel 6513, printed circuit board 6517, battery 6518, etc. are arranged in the space enclosed by the housing 6501 and the protective member 6510.

[0662] The protective member 6510 is fixed to the display panel 6511, the optical member 6512, and the touch sensor panel 6513 by an adhesive layer (not shown).

[0663] In the area outside the display unit 6502, a portion of the display panel 6511 is folded back, and the FPC 6515 is connected to this folded portion. IC 6516 is mounted on the FPC 6515. The FPC 6515 is connected to terminals provided on the printed circuit board 6517.

[0664] A flexible display according to one embodiment of the present invention can be applied to the display panel 6511. This makes it possible to realize an extremely lightweight electronic device. Furthermore, because the display panel 6511 is extremely thin, it is possible to incorporate a large-capacity battery 6518 while keeping the thickness of the electronic device low. In addition, by folding back a part of the display panel 6511 and placing the connection part with the FPC 6515 on the back of the pixel area, an electronic device with a narrow bezel can be realized.

[0665] Figure 29C shows an example of a television system. The television system 7100 has a display unit 7000 incorporated into a housing 7101. Here, the housing 7101 is shown supported by a stand 7103.

[0666] A display panel according to one embodiment of the present invention can be applied to the display unit 7000.

[0667] The television device 7100 shown in Figure 29C can be operated using the operation switches on the housing 7101 and a separate remote control unit 7111. Alternatively, the display unit 7000 may be equipped with a touch sensor, and the television device 7100 can be operated by touching the display unit 7000 with a finger or the like. The remote control unit 7111 may have a display unit that displays information output from the remote control unit 7111. Channels and volume can be controlled and the image displayed on the display unit 7000 can be controlled using the operation keys or touch panel on the remote control unit 7111.

[0668] The television system 7100 is configured to include a receiver and a modem. The receiver can receive general television broadcasts. Furthermore, by connecting to a wired or wireless communication network via the modem, it is possible to perform one-way (from sender to receiver) or two-way (between sender and receiver, or between receivers, etc.) information communication.

[0669] Figure 29D shows an example of a notebook personal computer. The notebook personal computer 7200 has a casing 7211, a keyboard 7212, a pointing device 7213, an external connection port 7214, etc. A display unit 7000 is incorporated into the casing 7211.

[0670] A display panel according to one embodiment of the present invention can be applied to the display unit 7000.

[0671] Figures 29E and 29F show examples of digital signage.

[0672] The digital signage 7300 shown in Figure 29E includes a housing 7301, a display unit 7000, and a speaker 7303, etc. Furthermore, it may include LED lamps, operation keys (including a power switch or operation switch), connection terminals, various sensors, a microphone, etc.

[0673] Figure 29F shows a digital signage 7400 mounted on a cylindrical column 7401. The digital signage 7400 has a display unit 7000 that is provided along the curved surface of the column 7401.

[0674] In Figures 29E and 29F, a display panel according to one embodiment of the present invention can be applied to the display unit 7000.

[0675] The larger the display area 7000, the more information can be provided at once. Furthermore, a larger display area 7000 is more eye-catching, which can, for example, enhance the effectiveness of advertising.

[0676] Applying a touch panel to the display unit 7000 is preferable because it not only allows images or videos to be displayed on the display unit 7000, but also enables intuitive operation by the user. Furthermore, when used for purposes such as providing route information or traffic information, intuitive operation can enhance usability.

[0677] Furthermore, as shown in Figures 29E and 29F, it is preferable that the digital signage 7300 or digital signage 7400 can be linked wirelessly with an information terminal 7311 or information terminal 7411 such as a smartphone owned by the user. For example, the advertising information displayed on the display unit 7000 can be displayed on the screen of the information terminal 7311 or information terminal 7411. Also, the display on the display unit 7000 can be switched by operating the information terminal 7311 or information terminal 7411.

[0678] Furthermore, the digital signage 7300 or digital signage 7400 can be used to run games using the screen of the information terminal 7311 or information terminal 7411 as the control device (controller). This allows an unspecified number of users to participate in and enjoy the game simultaneously.

[0679] The electronic equipment shown in Figures 30A to 30G includes a housing 9000, a display unit 9001, a speaker 9003, operation keys 9005 (including a power switch or operation switch), connection terminals 9006, sensors 9007 (including functions for measuring force, displacement, position, velocity, acceleration, angular velocity, rotational speed, distance, light, liquid, magnetism, temperature, chemical substances, sound, time, hardness, electric field, current, voltage, power, radiation, flow rate, humidity, gradient, vibration, odor, or infrared radiation), a microphone 9008, etc.

[0680] The electronic devices shown in Figures 30A to 30G have various functions. For example, they may have functions to display various information (still images, videos, text images, etc.) on a display unit, a touch panel function, a function to display a calendar, date or time, a function to control processing by various software (programs), a wireless communication function, a function to read and process programs or data recorded on a recording medium, etc. However, the functions of electronic devices are not limited to these and can have various functions. Electronic devices may have multiple display units. Furthermore, electronic devices may be equipped with a camera, etc., and have functions to capture still images or videos and save them to a recording medium (external or built into the camera), a function to display the captured images on a display unit, etc.

[0681] Details of the electronic equipment shown in Figures 30A to 30G will be explained below.

[0682] Figure 30A is a perspective view showing a personal digital assistant (PDA) 9101. The PDA 9101 can be used, for example, as a smartphone. The PDA 9101 may also be equipped with a speaker 9003, connection terminals 9006, sensors 9007, etc. The PDA 9101 can also display text and image information on multiple surfaces. Figure 30A show...

Claims

1. A display device comprising: a first pixel; a second pixel arranged adjacent to the first pixel; a first insulating layer; and a second insulating layer on the first insulating layer, The first pixel comprises a first pixel electrode, a first EL layer covering the first pixel electrode, a third insulating layer in contact with a portion of the upper surface of the first EL layer, and a common electrode on the first EL layer and the third insulating layer. The common electrode is in contact with another part of the upper surface of the first EL layer, The first EL layer is sandwiched between the first pixel electrode and the common electrode. The first EL layer contains the organic compound OM, The amount of the first EL layer containing an oxide of the organic compound OM or an organic compound having a partial structure of the organic compound OM is greater than 0 and less than or equal to 1 / 10 of the amount of the organic compound OM contained. The second pixel comprises a second pixel electrode, a second EL layer covering the second pixel electrode, a fourth insulating layer in contact with a portion of the upper surface of the second EL layer, and the common electrode on the second EL layer and the fourth insulating layer. The first insulating layer is in contact with the upper and side surfaces of the third insulating layer, the upper and side surfaces of the fourth insulating layer, the side surfaces of the first EL layer, and the side surfaces of the second EL layer. The first insulating layer, the third insulating layer, and the fourth insulating layer each have an inorganic material. The second insulating layer has an organic material, A portion of the second insulating layer overlaps with the first pixel electrode, Another portion of the second insulating layer overlaps with the second pixel electrode, The second insulating layer has a tapered shape on its side surface and a convex curved shape on its upper surface in cross-sectional view. The taper angle in the tapered shape of the side surface of the second insulating layer is less than 90°. The common electrode is superimposed on the second insulating layer. Display device.

2. In claim 1, The first pixel electrode and the second pixel electrode each have a tapered shape on their sides when viewed in cross-section. The taper angle in the tapered shape of the side surfaces of the first and second pixel electrodes is less than 90°. Display device.

3. In either claim 1 or claim 2, The first insulating layer, the third insulating layer, and the fourth insulating layer each have aluminum oxide. Display device.

4. In claim 1, The second insulating layer has a photosensitive acrylic resin, Display device.

5. In claim 1, A display device wherein the upper surface of the first EL layer, the upper surface of the second EL layer, and the upper surface of the second insulating layer have regions in contact with the common electrode.

6. In claim 1, The first pixel has a common layer disposed between the first EL layer and the common electrode, The second pixel has the common layer disposed between the second EL layer and the common electrode, A display device wherein the upper surface of the first EL layer, the upper surface of the second EL layer, and the upper surface of the second insulating layer have regions in contact with the common layer.

7. A first pixel electrode, a first EL layer covering the first pixel electrode, a first insulating layer in contact with the upper surface of the first EL layer, a second pixel electrode, a second EL layer covering the second pixel electrode, and a second insulating layer in contact with the upper surface of the second EL layer are formed. A third insulating layer is formed covering the first EL layer, the first insulating layer, the second EL layer, and the second insulating layer. A photosensitive organic resin is applied to the third insulating layer. A first exposure is performed to expose a portion of the organic resin to visible light or ultraviolet light. Developing is performed to remove a portion of the organic resin and form a fourth insulating layer. A first heat treatment is performed to make the side surface of the fourth insulating layer tapered and the upper surface of the fourth insulating layer convex curved, The first insulating layer, the second insulating layer, and a portion of the third insulating layer are removed, exposing the upper surface of the first EL layer and the upper surface of the second EL layer. A common electrode is formed by covering the first EL layer, the second EL layer, and the fourth insulating layer. The amount of ultraviolet light that the first EL layer and the second EL layer are exposed to between the time the upper surfaces of the first EL layer and the upper surfaces of the second EL layer are exposed and the common electrode is formed is 0 mJ / cm². ２ Larger, 1000 mJ / cm ２ The following will be suppressed: Method for manufacturing a display device.

8. In claim 7, The first EL layer and the second EL layer are formed by photolithography. The distance between the first EL layer and the second EL layer is such that there is a region of 8 μm or less. Method for manufacturing a display device.

9. In claim 7, A method for manufacturing a display device, wherein aluminum oxide is deposited as the third insulating layer using the ALD method.

10. In claim 7, A method for manufacturing a display device, wherein the organic resin is formed using a photosensitive acrylic resin.

11. In claim 7, The viscosity of the aforementioned organic resin is 1 cP or more and 1500 cP or less. Method for manufacturing a display device.

12. In claim 7, A method for manufacturing a display device, wherein a portion of the organic resin is located on a region that overlaps with the first pixel electrode or the second pixel electrode.

13. In claim 7, Before the first exposure, a second heating treatment is performed. The second heat treatment described above is performed at a temperature of 70°C to 120°C. Method for manufacturing a display device.

14. In claim 7, Before the first heat treatment, a second exposure is performed. The second exposure described above is 0 mJ / cm ２ Larger, 500 mJ / cm ２ Irradiate with the following visible light or ultraviolet light: Method for manufacturing a display device.

15. In claim 7, The first heat treatment described above is performed at a temperature of 70°C or higher and 130°C or lower. Method for manufacturing a display device.

16. In claim 7, After the first heat treatment, a third heat treatment is performed. The third heat treatment is performed at a temperature of 80°C or higher and 100°C or lower. Method for manufacturing a display device.

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