Indication device

Abstract

Provided is a high-definition display device. The display device has a first light emission device, a second light emission device, a first sidewall insulation layer, a second sidewall insulation layer, an insulation layer, a first coloration layer, and a second coloration layer. The first light emission device has a first pixel electrode, a first EL layer, and a common electrode. The second light emission device has a second pixel electrode, a second EL layer, and a common electrode. The first EL layer and the second EL layer display white light. The first sidewall insulation layer contacts a side surface of the first pixel electrode, and the second sidewall insulation layer contacts a side surface of the second pixel electrode. The insulation layer covers a side surface and a part of the upper surface of the first EL layer, and a side surface and a part of the upper surface of the second EL layer. The first coloration layer overlaps with the first light emission device, and the second coloration layer overlaps with the second light emission device. The first coloration layer and the second coloration layer each have a function of transmitting light of a different color.

Description

[Technical Field]

[0001] One aspect of the present invention relates to a display device, a display module, and electronic equipment. Another aspect of the present invention relates to a method for manufacturing a display device.

[0002] 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 include semiconductor devices, display devices, light-emitting devices, energy storage devices, memory devices, lighting devices, input devices (e.g., touch sensors), input / output devices (e.g., touch panels), display modules having these devices, electronic devices having said display modules, methods for driving them, or methods for manufacturing them. [Background technology]

[0003] In recent years, display devices have been expected to have applications in a variety of uses. For example, large-scale display devices are used in home television systems (also called televisions or television receivers), digital signage, and PID (Public Information Display). Furthermore, development is progressing on portable information terminals such as smartphones and tablet devices equipped with touch panels.

[0004] Furthermore, there is a demand for higher resolution display devices. Devices requiring high-resolution displays, such as those for virtual reality (VR), augmented reality (AR), substitutional reality (SR), and mixed reality (MR), are being actively developed.

[0005] As a display device, for example, a light-emitting device (also called a light-emitting element) has been developed. Light-emitting devices that utilize the electroluminescence (EL) phenomenon (also called EL devices or EL elements) have features such as being easy to make thin and light, being able to respond quickly to input signals, and being able to be driven using a DC constant voltage power supply, and are being applied to display devices.

[0006] Patent Document 1 discloses a display device for VR using an organic EL device (also called an organic EL element). [Prior art documents] [Patent Documents]

[0007] [Patent Document 1] International Publication No. 2018 / 087625 [Overview of the Initiative] [Problems that the invention aims to solve]

[0008] One aspect of the present invention aims to provide a high-definition display device. Another aspect of the present invention aims to provide a high-resolution display device. Another aspect of the present invention aims to provide a highly reliable display device.

[0009] One aspect of the present invention aims to provide a method for manufacturing a high-definition display device. Another aspect of the present invention aims to provide a method for manufacturing a high-resolution display device. Another aspect of the present invention aims to provide a method for manufacturing a highly reliable display device. Another aspect of the present invention aims to provide a method for manufacturing a display device with a high yield.

[0010] Furthermore, the description of these problems does not preclude the existence of other problems. One aspect of the present invention does not necessarily have to solve all of these problems. It is possible to extract other problems from the description in the specification, drawings, and claims. [Means for solving the problem]

[0011] One aspect of the present invention comprises a first light-emitting device, a second light-emitting device, a first sidewall insulating layer, a second sidewall insulating layer, a first insulating layer, a first colored layer, and a second colored layer, wherein the first light-emitting device comprises a first pixel electrode, a first EL layer on the first pixel electrode, and a common electrode on the first EL layer, and the second light-emitting device comprises a second pixel electrode, a second EL layer on the second pixel electrode, and a common electrode on the second EL layer, wherein the first EL layer and the second EL layer each emit blue light. The display device comprises a light-emitting material and a second light-emitting material that emits light with a wavelength longer than blue, wherein the first sidewall insulating layer is in contact with the side surface of the first pixel electrode, the second sidewall insulating layer is in contact with the side surface of the second pixel electrode, the first insulating layer covers a part of the upper surface and side surface of the first EL layer and a part of the upper surface and side surface of the second EL layer, the first colored layer overlaps with the first light-emitting device, the second colored layer overlaps with the second light-emitting device, and the first colored layer and the second colored layer each have the function of transmitting light of different colors.

[0012] Furthermore, it is preferable that, in the above configuration, there is a material layer between the first light-emitting device and the second light-emitting device, which is isolated from the first EL layer and the second EL layer, and the material layer comprises a first light-emitting material and a second light-emitting material.

[0013] Furthermore, it is preferable that the first sidewall insulating layer and the second sidewall insulating layer each have an inorganic insulating material.

[0014] Furthermore, in the above, it is preferable that the first insulating layer has a tapered shape at its end.

[0015] Furthermore, in the above, it is preferable that the first insulating layer has an organic insulating material.

[0016] Further preferably in the above, a second insulating layer is provided to cover part of an upper surface and side surfaces of the first EL layer, and part of an upper surface and side surfaces of the second EL layer, and the first insulating layer is provided over the second insulating layer.

[0017] Further preferably in the above, an end portion of the second insulating layer has a tapered shape.

[0018] Further preferably in the above, the second insulating layer contains an inorganic insulating material.

[0019] Further, one embodiment of the present invention is a display module including the above display device and at least one of a connector and an integrated circuit.

[0020] Further, one embodiment of the present invention is an electronic device including the above display module and at least one of a housing, a battery, a camera, a speaker, and a microphone. Effects of the Invention

[0021] According to one embodiment of the present invention, a high-definition display device can be provided. According to one embodiment of the present invention, a high-resolution display device can be provided. According to one embodiment of the present invention, a highly reliable display device can be provided.

[0022] According to one embodiment of the present invention, a method for manufacturing a high-definition display device can be provided. According to one embodiment of the present invention, a method for manufacturing a high-resolution display device can be provided. According to one embodiment of the present invention, a method for manufacturing a highly reliable display device can be provided. According to one embodiment of the present invention, a method for manufacturing a display device with high yield can be provided.

[0023] Note that the description of these effects does not preclude the existence of other effects. One embodiment of the present invention does not necessarily have all of these effects. Effects other than these can be extracted from the description of the specification, the drawings, and the claims. Brief Description of the Drawings

[0024] Figure 1A is a top view showing an example of a display device. Figure 1B is a cross-sectional view showing an example of a display device. Figure 2 is a cross-sectional view showing an example of a display device. Figures 3A to 3D are cross-sectional views showing an example of a display device. Figures 4A and 4B are cross-sectional views showing an example of a display device. Figures 5A and 5B are cross-sectional views showing an example of a display device. Figures 6A and 6B are cross-sectional views showing an example of a display device. Figures 7A and 7B are cross-sectional views showing an example of a display device. Figures 8A and 8B are cross-sectional views showing an example of a display device. Figures 9A to 9C are cross-sectional views showing an example of a display device. Figure 10 is a cross-sectional view showing an example of a display device. Figures 11A and 11B are cross-sectional views showing an example of a display device. Figures 12A and 12B are cross-sectional views showing an example of a display device. Figures 13A and 13B are cross-sectional views showing an example of a display device. Figures 14A to 14E are cross-sectional views showing an example of a method for manufacturing a display device. Figures 15A to 15D are cross-sectional views showing an example of a method for manufacturing a display device. Figures 16A to 16F are cross-sectional views showing an example of a method for manufacturing a display device. Figures 17A to 17G show examples of pixels. Figures 18A to 18I show examples of pixels. Figures 19A and 19B are perspective views showing an example of a display device. Figure 20 is a cross-sectional view showing an example of a display device. Figure 21 is a cross-sectional view showing an example of a display device. Figure 22 is a cross-sectional view showing an example of a display device. Figure 23 is a cross-sectional view showing an example of a display device. Figure 24 is a cross-sectional view showing an example of a display device. Figure 25 is a cross-sectional view showing an example of a display device. Figure 26 is a perspective view showing an example of a display device. Figure 27A is a cross-sectional view showing an example of a display device. Figures 27B and 27C are cross-sectional views showing an example of a transistor. Figures 28A to 28D are cross-sectional views showing an example of a display device. Figures 29A to 29F show examples of the configuration of a light-emitting device. Figures 30A to 30C show examples of the configuration of a light-emitting device. Figures 31A to 31D show examples of electronic devices. Figures 32A to 32F show examples of electronic devices. Figures 33A to 33G show examples of electronic devices. [Modes for carrying out the invention]

[0025] The embodiments will be described in detail below with reference to the drawings. However, it will be readily apparent to those skilled in the art that the present invention is not limited to the following description, and that its form and details can be modified in various ways without departing from the spirit and scope of the present invention. Therefore, the present invention should not be interpreted as being limited to the contents of the embodiments shown below.

[0026] 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.

[0027] Furthermore, the position, size, and scope of each component shown in the drawings may not represent the actual position, size, and scope for the sake of ease of understanding. Therefore, the disclosed invention is not necessarily limited to the position, size, and scope disclosed in the drawings.

[0028] It should be noted that the terms "film" and "layer" can be interchanged depending on the context or situation. For example, the term "conductive layer" can be changed to "conductive film." Or, for example, the term "insulating film" can be changed to "insulating layer."

[0029] In this specification, devices fabricated using a metal mask or an FMM (Fine Metal Mask, a high-resolution metal mask) may be referred to as MM (Metal Mask) structured devices. Furthermore, in this specification, devices fabricated without using a metal mask or FMM may be referred to as MML (Metal Maskless) structured devices.

[0030] 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.

[0031] In this specification, a light-emitting device has an EL layer between a pair of electrodes. The EL layer has at least a light-emitting layer. The layers (also called functional layers) of 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 this specification, one of the pair of electrodes may be referred to as a pixel electrode and the other as a common electrode.

[0032] In this specification, "island-like" 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.

[0033] In this specification, "step breakage" refers to the phenomenon in which a layer, film, or electrode is divided due to the shape of the surface on which it is formed (e.g., a step).

[0034] Furthermore, in this specification, a tapered shape refers to a shape in which at least a portion of the side surface of a structure is inclined with respect to the substrate surface or the surface to be formed. For example, it refers to a shape having a region in which the angle between the inclined side surface and the substrate surface or the surface to be formed (also called the taper angle) is less than 90°. Note that the side surface of the structure, the surface to be formed, and the substrate surface do not necessarily have to be perfectly flat, and may be substantially planar with fine curvature, or substantially planar with fine irregularities.

[0035] (Embodiment 1) In this embodiment, a display device according to one aspect of the present invention will be described with reference to Figures 1 to 13.

[0036] A display device according to one aspect of the present invention has a plurality of sub-pixels. Each sub-pixel has a light-emitting device having the same light-emitting material and a colored layer overlapping the light-emitting device. By providing a colored layer that transmits visible light of different colors in the sub-pixels, full-color display can be achieved.

[0037] When using light-emitting devices with the same light-emitting material, layers other than the pixel electrodes (e.g., the light-emitting layer) included in the light-emitting device can be shared by multiple subpixels. Therefore, multiple subpixels can share a continuous film. However, some layers included in the light-emitting device have relatively high conductivity. When multiple subpixels share a highly conductive layer as a continuous film, leakage current may occur between subpixels. In particular, as display devices become higher resolution or have a higher aperture ratio, and the distance between subpixels decreases, this leakage current can become significant enough to be considered a non-negligible size, potentially leading to a decrease in the display quality of the display device.

[0038] Therefore, in a display device according to one aspect of the present invention, the EL layer shared by multiple light-emitting devices has locally thin portions, or each of the multiple light-emitting devices has an island-shaped EL layer. By having a configuration in which the EL layer has portions with a small film thickness (also called thin portions), or a configuration in which the EL layer is separated for each light-emitting device, the occurrence of crosstalk between adjacent subpixels can be suppressed. As a result, high color reproducibility and high contrast can be achieved in the display device, and both high resolution and high display quality can be achieved in the display device. In addition, in a display device according to one aspect of the present invention, the EL layer may be formed in an island shape in some subpixels, and in this case, the EL layer may be a continuous layer in other multiple subpixels. In this case, it is preferable that the continuous layer has locally thin portions.

[0039] For example, island-shaped EL layers can be formed using a vacuum deposition method with a metal mask. However, with this method, deviations from the design occur in the shape and position of the island-shaped EL 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 display devices. In addition, the contour of the layer may become blurred during deposition, and the thickness at the edges may become thinner. In other words, island-shaped EL layers formed using a metal mask may have variations in thickness depending on the location. Furthermore, when manufacturing large, high-resolution, or high-definition display devices, 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.

[0040] Therefore, when manufacturing a display device according to one aspect of the present invention, island-shaped EL layers are formed without using a shadow mask (e.g., a metal mask).

[0041] For example, the greater the difference between the height of the upper surface of the insulating layer exposed between adjacent pixel electrodes and the height of the upper surface of the pixel electrode (which can also be called the step difference between adjacent pixel electrodes), the easier it becomes to form locally thin areas in the EL layer, and even to divide the EL layer to form island-like EL layers for each light-emitting device. By utilizing the step difference between adjacent pixel electrodes, it is possible to partially thin the EL layer or divide the EL layer in a self-aligning manner when depositing the EL layer. In other words, it is possible to suppress the occurrence of crosstalk without increasing the number of processes, and to realize a display device with high color reproduction and contrast.

[0042] Furthermore, if the EL layer has a thin film portion, or if the EL layer is separated for each light-emitting device, there is a risk of a short circuit occurring in the light-emitting device due to a common electrode coming into contact with an exposed portion of the pixel electrode.

[0043] Therefore, in a method for manufacturing a display device according to one aspect of the present invention, a sidewall insulating layer (also called a sidewall, sidewall protective layer, insulating layer, etc.) is provided in contact with the side surface of the pixel electrode. This suppresses contact between the pixel electrode and the common electrode, prevents short circuits in the light-emitting device, and improves the reliability of the light-emitting device.

[0044] Furthermore, if there is a large step difference between adjacent pixel electrodes, this step difference may cause the common electrode provided on the EL layer to be cut off.

[0045] Therefore, in a method for manufacturing a display device according to one aspect of the present invention, an insulating layer is provided so as to cover at least a part of the upper surface and the sides of the island-shaped EL layer. A common electrode is then provided so as to cover the insulating layer and the EL layer. This makes it possible to suppress the common electrode from being broken off due to the step difference between adjacent pixel electrodes.

[0046] Furthermore, it is preferable that the edges of the insulating layer have a tapered shape with a taper angle of less than 90° in cross-sectional view. This prevents the common electrode provided on the insulating layer from being cut off at a step, thereby suppressing connection failures of the common electrode. In addition, it is possible to suppress the local thinning of the common electrode due to the step at the edge of the insulating layer, which would increase the electrical resistance of the common electrode.

[0047] Thus, the island-shaped EL layer produced by the method for manufacturing a display device according to one aspect of the present invention is not formed using a fine metal mask, but rather by utilizing the step difference between pixel electrodes. Therefore, it is possible to realize a high-definition display device or a display device with a high aperture ratio, which has been difficult to achieve until now.

[0048] Regarding the spacing between adjacent light-emitting regions (also known as the shortest distance), for example, it is difficult to reduce it to less than 10 μm in a formation method using a fine metal mask. However, with a method for manufacturing a display device according to one aspect of the present invention, in a process on a glass substrate, for example, the spacing between adjacent light-emitting regions, adjacent EL layers, adjacent sidewall insulating layers, or adjacent pixel electrodes can be narrowed to less than 10 μm, 8 μm or less, 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. Furthermore, by using an exposure apparatus for LSIs, for example, in a process on a Si Wafer, the spacing between adjacent light-emitting regions, adjacent EL layers, adjacent sidewall insulating 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 the 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 still being less than 100%.

[0049] Furthermore, increasing the aperture ratio of the display device can improve its reliability. Specifically, as the aperture ratio increases, the current density flowing through the light-emitting device can be reduced, thereby extending the lifespan of the display device.

[0050] Furthermore, the resolution of the display device according to one embodiment of the present invention can be, for example, 1000 ppi or more, preferably 2000 ppi or more, preferably 3000 ppi or more, more preferably 5000 ppi or more, and even more preferably 6000 ppi or more, and can be 20000 ppi or less, or 30000 ppi or less.

[0051] In this embodiment, the cross-sectional structure of the display device according to one aspect of the present invention will be mainly described, and the method for manufacturing the display device according to one aspect of the present invention will be described in detail in Embodiment 2.

[0052] Figure 1A shows a top view of the display device 100. The display device 100 has a display unit on which a plurality of pixels 110 are arranged, and a connection unit 140 outside the display unit. Multiple subpixels are arranged in a matrix on the display unit. In Figure 1A, two rows and six columns of subpixels are shown, and these constitute a two-row, two-column pixel 110. The connection unit 140 can also be called the cathode contact unit.

[0053] The top surface shape of the subpixel shown in Figure 1A corresponds to the top surface shape of the light-emitting region.

[0054] Examples of the top surface shape of a sub-pixel include polygons such as triangles, quadrilaterals (including rectangles, rhombuses, and squares), pentagons, polygons with rounded corners, ellipses, or circles.

[0055] Furthermore, the circuit layout constituting the subpixel is not limited to the subpixel range shown in Figure 1A, but may be located outside of it. In other words, some or all of the transistors (not shown) of the subpixel 11R shown in Figure 1A may be located outside the range of the subpixel 11R. The transistors of the subpixel 11R may be located within the range of the subpixel 11R shown in Figure 1A, within the range of the subpixel 11G, within the range of the subpixel 11B, or may be arranged across multiple of these ranges.

[0056] In Figure 1A, the aperture ratios (sizes, also known as the size of the light-emitting area) of sub-pixels 11R, 11G, and 11B are shown to be equal or approximately equal, but the present invention is not limited to this. The aperture ratios of sub-pixels 11R, 11G, and 11B can be determined as appropriate. The aperture ratios of sub-pixels 11R, 11G, and 11B may be different, or two or more may be equal or approximately equal.

[0057] A stripe array is applied to pixel 110 shown in Figure 1A. Pixel 110 in Figure 1A is composed of three subpixels: subpixel 11R, subpixel 11G, and subpixel 11B. Subpixels 11R, 11G, and 11B each emit light of a different color. Examples of subpixels 11R, 11G, and 11B 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; 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).

[0058] In this specification, 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). Figure 1A shows an example where subpixels of different colors are arranged in the X direction, and subpixels of the same color are arranged in the Y direction.

[0059] 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 surface 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.

[0060] Figure 1B shows a cross-sectional view between the dashed lines X1 and X2 in Figure 1A. Figure 2 shows a cross-sectional view between the dashed lines Y1 and Y2 in Figure 1A. Figure 3A shows an enlarged view of region 150A shown in Figure 1B. Figures 3B to 3D show modified examples of region 150A, namely regions 150B to 150D, respectively.

[0061] The sub-pixel 11R includes a light-emitting device 130R and a colored layer 132R that transmits red light. As a result, the light emitted from the light-emitting device 130R is extracted as red light to the outside of the display device via the colored layer 132R.

[0062] The sub-pixel 11G includes a light-emitting device 130G and a colored layer 132G that transmits green light. As a result, the light emitted from the light-emitting device 130G is extracted as green light to the outside of the display device via the colored layer 132G.

[0063] The sub-pixel 11B includes a light-emitting device 130B and a colored layer 132B that transmits blue light. As a result, the light emitted from the light-emitting device 130B is extracted as blue light to the outside of the display device via the colored layer 132B.

[0064] Here, blue light can be defined as light with a peak wavelength of emission spectrum between 400 nm and 480 nm. Green light can be defined as light with a peak wavelength of emission spectrum between 480 nm and 580 nm. Red light can be defined as light with a peak wavelength of emission spectrum between 580 nm and 700 nm.

[0065] The colored layer is a colored layer that selectively transmits light in a specific wavelength range and absorbs light in other wavelength ranges. For example, a color filter that transmits light in the red wavelength range can be used for the colored layer 132R. For example, a color filter that transmits light in the green wavelength range can be used for the colored layer 132G. For example, a color filter that transmits light in the blue wavelength range can be used for the colored layer 132B. Materials that can be used for the colored layer include metal materials, resin materials, or resin materials containing pigments or dyes.

[0066] As shown in Figure 1B, the display device 100 has an insulating layer (insulating layer 255a, insulating layer 255b, and insulating layer 255c) on a layer 101 including a transistor (not shown), and light-emitting devices 130R, 130G, and 130B are provided on the insulating layer, with a protective layer 131 and an insulating layer 135 covering these light-emitting devices. Colored layers 132R, 132G, and 132B are provided on the insulating layer 135, and a substrate 120 is bonded to the colored layers 132R, 132G, and 132B by a resin layer 122. Colored layer 132R is provided in a position overlapping with light-emitting device 130R. Colored layer 132G is provided in a position overlapping with light-emitting device 130G. Colored layer 132B is provided in a position overlapping with light-emitting device 130B. Furthermore, an insulating layer 125 and an insulating layer 127 on the insulating layer 125 are provided in the region between adjacent light-emitting devices.

[0067] In Figure 1B, multiple cross-sections of the insulating layer 125 and insulating layer 127 are shown, but when the display device 100 is viewed from above, the insulating layer 125 and insulating layer 127 are connected as one unit each. In other words, the display device 100 can be configured to have, for example, one insulating layer 125 and one insulating layer 127. The display device 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.

[0068] A display device according to one aspect of the present invention may be a top-emission type that emits light in the direction opposite to the substrate on which the light-emitting 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. In this embodiment, a top-emission type display device will be described as an example.

[0069] Layer 101 can be a laminated structure in which, for example, multiple transistors (not shown) are provided on a substrate, and an insulating layer is provided to cover these transistors. The insulating layer on the transistor may be a single layer or a laminated structure. Figure 1B shows insulating layer 255a, insulating layer 255b on insulating layer 255a, and insulating layer 255c on insulating layer 255b, which are part of the insulating layer on the transistor. Note that the insulating layer on the transistor (insulating layers 255a to insulating layers 255c) can also be considered as part of layer 101.

[0070] As will be described later, it is preferable that the insulating layer 255c has a recess between two adjacent light-emitting devices. This creates a large step between adjacent pixel electrodes when the EL layer is formed, making it easy to form the EL layer separately for each light-emitting device. Figure 1B shows an example in which the insulating layer 255c has a recess. Alternatively, the insulating layer 255c may have an opening between two adjacent light-emitting devices, in which case the insulating layer 255b may also have a recess.

[0071] 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.

[0072] In this specification, the term "oxide-nitride" refers to a material in which the oxygen content is greater than the nitrogen content, and the term "nitride oxide" refers to a material in which the nitrogen content is greater than the oxygen content. For example, when "silicon oxynitride" is written, it refers to a material in which the oxygen content is greater than the nitrogen content, and when "silicon nitride oxide" is written, it refers to a material in which the nitrogen content is greater than the oxygen content.

[0073] An example of the configuration of layer 101 will be described later in Embodiment 4.

[0074] As the light-emitting device, it is preferable to use, for example, an OLED (Organic Light Emitting Diode) or a QLED (Quantum-dot Light Emitting Diode). Examples of light-emitting materials for the light-emitting device include fluorescent materials, phosphorescent materials, thermally activated delayed fluorescence (TADF) materials, and inorganic compounds (quantum dot materials, etc.). In addition, LEDs such as microLEDs (Light Emitting Diodes) can also be used as the light-emitting device.

[0075] The light-emitting device can emit light in the following colors: infrared, red, green, blue, cyan, magenta, yellow, or white. Furthermore, the color purity can be improved by adding a microcavity structure to the light-emitting device.

[0076] In a pair of electrodes in a light-emitting device, it is preferable to use a conductive film that transmits visible light for the electrode that extracts light, and a conductive film that reflects visible light for the electrode that does not extract light.

[0077] 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.

[0078] The light-emitting device 130R includes a pixel electrode 111R on an insulating layer 255c, an island-shaped EL layer 113 on the pixel electrode 111R, and a common electrode 115 on the EL layer 113.

[0079] The light-emitting device 130G includes a pixel electrode 111G on an insulating layer 255c, an island-shaped EL layer 113 on the pixel electrode 111G, and a common electrode 115 on the EL layer 113.

[0080] The light-emitting device 130B includes a pixel electrode 111B on an insulating layer 255c, an island-shaped EL layer 113 on the pixel electrode 111B, and a common electrode 115 on the EL layer 113.

[0081] Light-emitting devices 130R, 130G, and 130B each independently have island-shaped EL layers 113. These EL layers 113 are formed in the same process and have the same configuration. Therefore, it can be said that these EL layers 113 have the same light-emitting material.

[0082] The EL layer 113 can be configured to emit white light. For example, the EL layer 113 may include a first light-emitting material that emits blue light and a second light-emitting material that emits light with a longer wavelength than blue light.

[0083] Furthermore, by applying a microcavity structure, light-emitting devices with an EL layer configured to emit white light may also emit light of specific wavelengths such as red, green, and blue, with increased intensity.

[0084] For example, by applying a configuration that emits white light to the EL layer 113 and also applying a microcavity structure, red light emission can be obtained from the light-emitting device 130R, green light emission from the light-emitting device 130G, and blue light emission from the light-emitting device 130B.

[0085] The light-emitting device of this embodiment may be a single structure (a structure having only one light-emitting unit) or a tandem structure (a structure having multiple light-emitting units). The light-emitting unit has at least one light-emitting layer.

[0086] The EL layer 113 has at least an emissive layer. The EL layer 113 can be configured to have, for example, an emissive layer that emits blue light and an emissive layer that emits light with a longer wavelength than blue light.

[0087] Furthermore, when using a tandem light-emitting device, the EL layer 113 can be configured to include, for example, a light-emitting unit that emits blue light and a light-emitting unit that emits light with a longer wavelength than blue light. It is preferable to provide a charge generation layer (also called an intermediate layer) between each light-emitting unit. By applying a tandem structure, a light-emitting device capable of high-brightness emission can be realized.

[0088] Furthermore, the EL layer 113 may 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.

[0089] For example, the EL layer 113 may have a hole injection layer, a hole transport layer, an emissive layer, an electron transport layer, and an electron injection layer in that order from the anode side. Alternatively, an electron blocking layer may be present between the hole transport layer and the emissive layer. Furthermore, a hole blocking layer may be present between the electron transport layer and the emissive layer.

[0090] Furthermore, for example, the EL layer 113 may include a first light-emitting unit, a charge generation layer on the first light-emitting unit, and a second light-emitting unit on the charge generation layer.

[0091] For more detailed information on the configuration and materials of the light-emitting device, please refer to Embodiment 5.

[0092] In Figure 1B, the EL layers 113 of each light-emitting device are isolated from each other. By providing the EL layers in an island-like arrangement for each light-emitting device, leakage current between adjacent light-emitting devices can be suppressed. This prevents unintended light emission caused by crosstalk, enabling the realization of a display device with extremely high contrast. In particular, it enables the realization of a display device with high current efficiency at low brightness.

[0093] Furthermore, a material layer 113s, which is formed in the same process as the EL layer 113 and has the same structure, is located on the insulating layer 255c. The material layer 113s is separated from the EL layer 113 when the layers constituting the EL layer 113 are formed, and is independently provided on the insulating layer 255c.

[0094] Furthermore, the region where any of the pixel electrodes 111R, 111G, and 111B overlap with the EL layer 113 and the common electrode 115 can be called an emissive region, and this is the region where EL emission is obtained. This emissive region and the region where the material layer 113s is provided are both regions where PL (photoluminescence) emission is obtained. From these points, it can be said that the emissive region and the region where the material layer 113s is provided can be distinguished by confirming EL emission and PL emission.

[0095] Sidewall insulating layers 114 are provided so as to be in contact with the side surfaces of the pixel electrode 111R, the pixel electrode 111G, and the pixel electrode 111B, respectively. By providing the sidewall insulating layers 114, it is possible to suppress contact between the common electrode 115 and any of the pixel electrodes 111R, 111G, and 111B. Therefore, short circuits in the light-emitting device can be suppressed, and the reliability of the light-emitting device can be improved.

[0096] For the sidewall insulating layer 114, an inorganic insulating film such as an oxide insulating film, a nitride insulating film, an oxidative nitride insulating film, or an oxidative nitride insulating film can be used. 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 nitride film.

[0097] The side wall insulating layer 114 may be a single layer or a multilayer structure.

[0098] The method for forming the sidewall insulating layer 114 is not particularly limited. The sidewall insulating layer 114 can be formed, for example, by sputtering, chemical vapor deposition (CVD), plasma-enhanced chemical vapor deposition (PECVD), or atomic layer deposition (ALD). In particular, using sputtering, CVD, or PECVD, which have faster deposition rates than ALD, is preferable because it is possible to produce a sidewall insulating layer 114 of sufficient thickness to ensure insulation with high productivity.

[0099] For example, it is preferable to use a silicon oxide film, a silicon nitride film, a silicon oxynitride film, or a silicon nitride film as the sidewall insulating layer 114. This makes it possible to manufacture highly reliable display devices with high productivity.

[0100] Alternatively, an aluminum oxide film may be formed as the sidewall insulating layer 114 using the ALD method. By using the ALD method, the sidewall insulating layer 114 can be formed with high coverage.

[0101] In Figure 1B, there is no insulating layer (also called a partition, bank, or spacer) covering the upper edge of the pixel electrode 111R between the pixel electrode 111R and the EL layer 113. Similarly, there is no insulating layer covering the upper edge of the pixel electrode 111G between the pixel electrode 111G and the EL layer 113. Likewise, there is no insulating layer covering the upper edge of the pixel electrode 111B between the pixel electrode 111B and the EL layer 113. As a result, the spacing between adjacent light-emitting regions can be made extremely narrow. Therefore, a high-definition or high-resolution display device can be realized. In addition, a mask for forming the insulating layer is unnecessary, which can reduce the manufacturing cost of the display device.

[0102] Furthermore, by omitting an insulating layer that covers a portion of the upper surface of the pixel electrode (which can also be called the edge of the upper surface) between the pixel electrode and the EL layer, in other words, by omitting an insulating layer between the pixel electrode and the EL layer, light emission from the EL layer can be efficiently extracted. Therefore, a display device according to one aspect of the present invention can have extremely low viewing angle dependence. By reducing viewing angle dependence, the visibility of images in the display device can be improved. For example, in a display device according to one aspect 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 set to a 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 viewing angles.

[0103] In Figure 1B, the EL layer 113 is formed to cover the entire upper surface of each of the pixel electrodes 111R, 111G, and 111B. This configuration makes it possible to make the entire upper surface of the pixel electrode a light-emitting region. Furthermore, it becomes easier to increase the aperture ratio compared to a configuration in which an insulating layer covers only a part of the upper surface of the pixel electrode.

[0104] Furthermore, the common electrode 115 is shared by light-emitting devices 130R, 130G, and 130B. The common electrode 115, which is shared by multiple light-emitting devices, is electrically connected to a conductive layer 123 provided at the connection portion 140 (see Figure 2). 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 electrode 111R, pixel electrode 111G, and pixel electrode 111B.

[0105] In Figure 2, 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 on the EL layer 113 and the common electrode 115 can be changed.

[0106] Furthermore, in Figure 1B, an insulating layer 125 is provided so as to cover the region between adjacent light-emitting devices, specifically the upper edges and sides of adjacent EL layers 113, a portion of the sides of adjacent sidewall insulating layers 114, and the upper surface of the material layer 113s. In other words, the insulating layer 125 can be described as being provided in a non-light-emitting region, or having an opening in a portion that overlaps with the light-emitting region.

[0107] In Figure 1B, one end of the insulating layer 125 is located on the upper surface of one of the adjacent EL layers 113, and the other end of the insulating layer 125 is located on the upper surface of the other adjacent EL layer 113. Here, it is preferable that the end of the insulating layer 125 overlaps with the EL layer 113 and the pixel electrode 111R (or pixel electrode 111G, pixel electrode 111B). In this case, the end of the insulating layer 125 is more likely to be formed on the generally flat surface of the EL layer 113.

[0108] The sides of the EL layer 113 are covered by the insulating layer 125. The insulating layer 127 is provided overlapping the sides of the EL layer 113 via the insulating layer 125.

[0109] Furthermore, a portion of the upper surface of the EL layer 113 is covered by the insulating layer 125. The insulating layer 127 is provided overlapping a portion of the upper surface of the EL layer 113 via the insulating layer 125. Note that the upper surface of the EL layer 113 is not limited to the upper surface of the flat portion that overlaps with the upper surface of the pixel electrode, but can also include the upper surface of the region located outside the upper surface of the pixel electrode (see region 103 in Figure 7A).

[0110] By covering a portion of the upper surface and side surface of the EL layer 113 with at least one of the insulating layer 125 and insulating layer 127, contact between the common electrode 115 and the pixel electrode 111R, pixel electrode 111G, pixel electrode 111B, and the side surface of the EL layer 113 can be suppressed, thereby preventing a short circuit in the light-emitting device.

[0111] The insulating layer 125 is preferably in contact with the upper edge and side surface of the EL layer 113. By configuring the insulating layer 125 to be in contact with the EL layer 113, peeling of the EL layer 113 can be prevented. The close contact between the insulating layer 125 and the EL layer 113 provides the effect of fixing or bonding adjacent EL layers 113 to each other.

[0112] Furthermore, as shown in Figure 1B, the insulating layer 125 and the insulating layer 127 cover both a portion of the upper surface and the side surface of the EL layer 113, thereby further preventing peeling of the EL layer 113.

[0113] 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 a portion of the upper surface and side surfaces of the EL layer 113 via the insulating layer 125. Preferably, the insulating layer 127 covers at least a portion of the side surfaces of the insulating layer 125.

[0114] By providing insulating layers 125 and 127, the gaps between adjacent island-shaped layers can be filled, thereby reducing extreme irregularities on the surface of layers formed on the island-shaped layers (e.g., carrier injection layers, common electrodes, etc.) and making them flatter. Consequently, the coverage of carrier injection layers, common electrodes, etc. can be improved.

[0115] The common electrode 115 is provided on the EL layer 113, the insulating layer 125, and the insulating layer 127. Before the insulating layer 125 and the insulating layer 127 are provided, there is a step difference between the region where the pixel electrode and island-shaped EL layer are provided (the region where the light-emitting device is located) and the region where the pixel electrode and island-shaped EL layer are not provided (the region between the light-emitting devices). In one embodiment of the present invention, the presence of the insulating layer 125 and the insulating layer 127 can flatten this step difference and improve the coverage of the common electrode 115. Therefore, connection failures due to step breaks in the common electrode 115 can be suppressed. In addition, it is possible to suppress the local thinning of the common electrode 115 due to the step difference, which would increase the electrical resistance of the common electrode 115.

[0116] The upper surface of the insulating layer 127 preferably has a shape that is more flat, but it may also have convex portions, convex curved surfaces, concave curved surfaces, or recesses. For example, the upper surface of the insulating layer 127 preferably has a flat, smooth convex curved surface shape.

[0117] Next, we will describe examples of materials for the insulating layer 125 and the insulating layer 127.

[0118] 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 structure or a multilayer 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 oxide film and aluminum nitride oxide 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.

[0119] 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.

[0120] 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).

[0121] 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 a highly reliable light-emitting device, and furthermore, a highly reliable display device.

[0122] 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.

[0123] 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 forming the common electrode 115.

[0124] 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 resin composition containing an acrylic resin is preferred. 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.

[0125] Furthermore, as the insulating layer 127, acrylic resin, polyimide resin, epoxy resin, imide resin, polyamide resin, polyimidoamide resin, silicone resin, siloxane resin, benzocyclobutene resin, phenol resin, precursors of these resins, etc. may be used. Alternatively, as the insulating layer 127, 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. Additionally, a photoresist may be used as the photosensitive resin. Either a positive-type or negative-type material may be used as the photosensitive organic resin.

[0126] 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 device. Furthermore, since the display quality can be improved without using a polarizing plate in the display device, the display device can be made lighter and thinner.

[0127] 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.

[0128] Due to the effects described above, a display device according to one aspect of the present invention can improve display quality, enhance the reliability of the light-emitting device, and further increase the manufacturing yield of the light-emitting device.

[0129] In the region 150A shown in Figures 1B and 3A, island-shaped EL layers 113 are provided on the pixel electrode 111G, island-shaped EL layers 113 are provided on the pixel electrode 111B, and a material layer 113s is provided on the insulating layer 255c. The EL layer 113 on the pixel electrode 111G, the EL layer 113 on the pixel electrode 111B, and the material layer 113s are all isolated from each other.

[0130] In this way, by separating the EL layer for each light-emitting device, the occurrence of crosstalk between adjacent subpixels can be suppressed.

[0131] Here, we will describe a preferred configuration of the side wall insulating layer 114 for partially thinning or dividing the EL layer 113 in a self-aligning manner when forming the EL layer 113.

[0132] The height T1 of the sidewall insulating layer 114 shown in Figure 3A is preferably 0.5 times or more the thickness of the EL layer 113, more preferably 0.8 times or more, even more preferably 1 time or more, and even more preferably 1.5 times or more.

[0133] It is preferable to use the thickness of the sidewall insulating layer 114 perpendicular to the substrate surface as the height T1 of the sidewall insulating layer 114. In Figure 3A, the height T1 of the sidewall insulating layer 114 can also be expressed as the sum of the thickness of the pixel electrode and the depth of the recess provided in the insulating layer 255c.

[0134] As shown in Figure 3A, it is preferable to use the thickness T2 of the EL layer 113 in the region that overlaps with the upper surface of the pixel electrode.

[0135] Furthermore, it is preferable that the angle between at least a portion of the surface of the sidewall insulating layer 114 that is in contact with the EL layer 113 (for example, the side surface) and the substrate surface be perpendicular or approximately perpendicular. This angle can also be said to be the angle between a portion of the surface of the sidewall insulating layer 114 that is in contact with the EL layer 113 (for example, the side surface) and the bottom surface. This angle is preferably 60° or more, more preferably 80° or more, even more preferably 85° or more, and also preferably 140° or less, more preferably 110° or less, even more preferably 100° or less, and even more preferably 95° or less.

[0136] Furthermore, in order to bring the angle within the above numerical range, it is preferable that the angle between the side surface of the pixel electrode and the substrate surface be perpendicular or approximately perpendicular. The angle between the side surface of the pixel electrode and the substrate surface is preferably 60° or more, more preferably 80° or more, even more preferably 85° or more, and also preferably 140° or less, more preferably 110° or less, even more preferably 100° or less, and even more preferably 95° or less.

[0137] Region 150B shown in Figure 3B and region 150C shown in Figure 3C are examples in which the EL layer 113 is provided so as to cover the pixel electrode 111G, the side wall insulating layer 114, the insulating layer 255c, and the pixel electrode 111B.

[0138] The region 113t shown in Figure 3B is a part of the EL layer 113 that is thinner than other parts.

[0139] Note that the thickness of the EL layer 113 in region 113t refers to the thickness in the direction normal to the surface to be formed, not the thickness perpendicular to a reference surface such as the substrate surface. Therefore, if the surface to be formed has irregularities, the direction in which the thickness is defined will differ depending on the location. For example, the thickness of the EL layer 113 in region 113t can be said to be the thickness in the direction normal to the side surface of the side wall insulating layer 114.

[0140] Thus, when the EL layer 113 is partially thinned, the electrical resistance of the thinned portion becomes higher than that of other portions, thereby reducing the leakage current between adjacent light-emitting devices. Therefore, as shown in Figures 3B and 3C, even in a configuration where the EL layer 113 is connected between adjacent light-emitting devices, the occurrence of crosstalk between adjacent subpixels can be suppressed.

[0141] Region 150C, shown in Figure 3C, differs from the configuration of region 150B in that the insulating layer 255c does not have a recess between two adjacent light-emitting devices.

[0142] Furthermore, region 150D shown in Figure 3D is an example in which the insulating layer 255c has two recesses, a shallow recess and a deep recess, between two adjacent light-emitting devices.

[0143] Recesses may be formed in the insulating layer 255c during the processing of the conductive film that will become the pixel electrode. Furthermore, recesses may also be formed in the insulating layer 255c during the processing of the insulating film that will become the sidewall insulating layer 114. As a result, shallow and deep recesses are provided. In Figure 3D, the sidewall insulating layer 114 is in contact with the shallow recesses, and the material layer 113s is in contact with the deep recesses.

[0144] Furthermore, the distance T0 between the surface of the deep recess in the insulating layer 255c and the bottom surface of the side wall insulating layer 114, as shown in Figure 3D, is also a parameter that affects whether the EL layer 113 is partially thinned or divided.

[0145] For the same reasons as above, for example, the sum of the distance T0 and the height T1 of the sidewall insulating layer 114 is preferably 0.5 times or more the thickness of the EL layer 113, more preferably 0.8 times or more, even more preferably 1 time or more, and even more preferably 1.5 times or more.

[0146] In Figure 3D, the sum of the distance T0 and the height T1 of the sidewall insulating layer 114 can also be expressed as the sum of the thickness of the pixel electrode and the depth of the recess provided in the insulating layer 255c.

[0147] As described above, in a display device according to one aspect of the present invention, by providing a side wall insulating layer 114 in contact with the side surface of the pixel electrode, contact between the pixel electrode and the common electrode 115 can be suppressed, thereby preventing a short circuit in the light-emitting device. Furthermore, by configuring the height and shape of the side wall insulating layer 114 to be suitable for partially thinning the EL layer 113 or for dividing the EL layer 113, the occurrence of crosstalk between adjacent subpixels can be suppressed.

[0148] From the above, it can also be said that a display device according to one aspect of the present invention is configured to intentionally create a stepped section in the EL layer 113.

[0149] Next, the structure of the insulating layer 127 and its vicinity will be described using Figures 4A and 4B. Figure 4A is a magnified cross-sectional view of the region including the insulating layer 127 and its surrounding area between the light-emitting device 130R of the subpixel that emits red light and the light-emitting device 130G of the subpixel that emits green light. In the following description, the insulating layer 127 between two adjacent light-emitting devices 130R and 130G will be used as an example, but the same applies to the insulating layer 127 between light-emitting devices 130G and 130B. Figure 4B is a magnified view of the edge of the insulating layer 127 on the EL layer 113 and its vicinity, as shown in Figure 4A. Note that the common electrode 115 and the protective layer 131 are not shown in Figure 4B.

[0150] As shown in Figure 4A, an EL layer 113 is provided covering the pixel electrode 111R and the side wall insulating layer 114, and an EL layer 113 is provided covering the pixel electrode 111G and the side wall insulating layer 114. An insulating layer 125 is provided in contact with a part of the upper surface and the side surface of the EL layer 113. An insulating layer 127 is provided in contact with the upper surface of the insulating layer 125. In addition, the insulating layer 127 overlaps with a part of the upper surface and the side surface of the EL layer 113 via the insulating layer 125 and is in contact with at least a part of the side surface of the insulating layer 125. A common electrode 115 is provided covering the EL layer 113, the insulating layer 125, and the insulating layer 127, and a protective layer 131 is provided on the common electrode 115.

[0151] Furthermore, the insulating layer 127 is formed in the region between the two island-shaped EL layers (for example, in Figure 4A, the region between the two EL layers 113). At this time, at least a portion of the insulating layer 127 is positioned between the side edge of one EL layer and the side edge of the other EL layer. By providing such an insulating layer 127, it is possible to prevent the formation of divided areas and locally thin areas in the common electrode 115 formed on the island-shaped EL layers and the insulating layer 127.

[0152] As shown in Figure 4B, the insulating layer 127 preferably has a tapered shape with a taper angle θ1 at its end in a cross-sectional view of the display device. The taper angle θ1 is the angle between the side surface (or end) 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 upper surface of the flat portion of the EL layer 113, or the upper surface of the flat portion of the pixel electrode 111G, and the side surface (or end) of the insulating layer 127.

[0153] The taper angle θ1 of the insulating layer 127 is less than 90°, preferably 60° or less, more preferably 45° or less, and even more preferably 20° or less. By making the edges of the insulating layer 127 tapered in this way, the common electrode 115 provided on the insulating layer 127 can be formed with good coverage, and the occurrence of stepped breaks or localized thinning of the common electrode 115 can be suppressed. As a result, the in-plane uniformity of the film thickness of the common electrode 115 can be improved, and the display quality of the display device can be improved.

[0154] Furthermore, as shown in Figure 4A, 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 convex curved portion in the center of the upper surface of the insulating layer 127 is continuously connected to the tapered portion at the end. By making the insulating layer 127 such a shape, the common electrode 115 can be formed on the entire insulating layer 127 with good coverage.

[0155] As shown in Figure 4B, the insulating layer 125 preferably has a tapered shape with a taper angle θ2 at the end (inclined portion) that overlaps with the insulating layer 127 in a cross-sectional view of the display device. The taper angle θ2 is the angle between the side surface of the end and the substrate surface. However, it is not limited to the substrate surface; it may also be the angle between the upper surface of the flat portion of the EL layer 113, or the upper surface of the flat portion of the pixel electrode 111G, and the side surface of the end.

[0156] The taper angle θ2 of the insulating layer 125 is less than 90°, preferably 60° or less, more preferably 45° or less, and even more preferably 20° or less.

[0157] Furthermore, as shown in Figure 4B, it is preferable that the insulating layer 125 has a tapered shape with a taper angle θ3 at the end (inclined portion) that does not overlap with the insulating layer 127 in a cross-sectional view of the display device. The taper angle θ3 is the angle between the side surface of the end and the substrate surface. However, it is not limited to the substrate surface; it may also be the angle between the upper surface of the flat portion of the EL layer 113, or the upper surface of the flat portion of the pixel electrode 111G, and the side surface of the end.

[0158] The taper angle θ3 of the insulating layer 125 is less than 90°, preferably 60° or less, more preferably 45° or less, and even more preferably 20° or less. By making the insulating layer 125 such a tapered shape, the common electrode 115 provided on the insulating layer 125 can be formed with good coverage.

[0159] As will be detailed in Embodiment 2, if the etching process of the insulating film that forms the insulating layer 125 is performed in one go, side etching may cause the insulating layer 125 below the edge of the insulating layer 127 to disappear, forming a cavity. This cavity can cause unevenness on the surface forming the common electrode 115, making it easier for the common electrode 115 to break down. Therefore, by performing the etching process in two stages and performing a heat treatment between the two etching processes, even if a cavity is formed in the first etching process, the heat treatment will deform the insulating layer 127 and fill the cavity. In addition, since the second etching process involves etching a thin film, the amount of side etching is reduced, making it less likely for a cavity to form, or if a cavity does form, it can be made extremely small. Therefore, it is possible to suppress the occurrence of unevenness on the surface forming the common electrode 115, and to suppress the common electrode 115 from breaking down. As the etching process is performed in two stages in this way, the taper angles θ2 and θ3 may be different angles. Alternatively, the taper angles θ2 and θ3 may be the same angle. Furthermore, the taper angles θ2 and θ3 may each be smaller than the taper angle θ1.

[0160] Although the above example shows the etching of the insulating film that forms the insulating layer 125 being performed in two stages, this is not limited to this. Depending on the thickness of the insulating film that forms the insulating layer 125, or the etching conditions, it may be possible to perform the etching of the insulating film that forms the insulating layer 125 in a single stage.

[0161] Furthermore, Figures 5A and 5B show examples in which the insulating layer 127 covers the entire side surface of the insulating layer 125. Specifically, in Figure 5B, the insulating layer 127 covers both of the two inclined surfaces in contact with each other. This is preferable because it can further reduce the unevenness of the surface forming the common electrode 115. Figure 5B shows an example in which the edge of the insulating layer 127 is located outside the edge of the insulating layer 125. The edge of the insulating layer 127 may be located inside the edge of the insulating layer 125, as shown in Figure 4B, and may be aligned with or approximately aligned with the edge of the insulating layer 125. Also, as shown in Figure 5B, the insulating layer 127 may be in contact with the EL layer 113.

[0162] In Figure 5B, it is preferable that the taper angles θ1 to θ3 are within the above ranges.

[0163] Furthermore, Figures 6A and 6B show examples in which the insulating layer 127 has a concave curved shape (also called a constricted portion, recess, indentation, or depression) on its side surface. Depending on the material of the insulating layer 127 and the formation conditions (heating temperature, heating time, heating atmosphere, etc.), a concave curved shape may be formed on the side surface of the insulating layer 127.

[0164] Figure 6A shows an example where the insulating layer 127 covers a portion of the side surface of the insulating layer 125, leaving the rest of the side surface exposed. Figure 6B shows an example where the insulating layer 127 is in contact with and covers the entire side surface of the insulating layer 125.

[0165] Furthermore, as shown in Figures 4 to 6, it is preferable that one end of the insulating layer 127 overlaps with the upper surface of the pixel electrode 111R, and the other end of the insulating layer 127 overlaps with the upper surface of the pixel electrode 111G. With this structure, the end of the insulating layer 127 can be formed on a generally flat region of the EL layer 113. Therefore, it becomes relatively easy to form the tapered shape of the insulating layer 127 and the insulating layer 125. In addition, peeling of the film between the EL layer 113 and the pixel electrode 111R or the pixel electrode 111G can be suppressed. On the other hand, the smaller the overlap between the upper surface of the pixel electrode and the insulating layer 127, the wider the light-emitting region of the light-emitting device becomes, and the higher the aperture ratio can be, which is preferable.

[0166] Note that the insulating layer 127 does not have to overlap with the upper surface of the pixel electrode. As shown in Figure 7A, the insulating layer 127 does not overlap with the upper surface of the pixel electrode, and in a plan view, the position of one end of the insulating layer 127 may roughly coincide with the position of the side surface of the pixel electrode 111R, and the position of the other end of the insulating layer 127 may roughly coincide with the position of the side surface of the pixel electrode 111G. Also, as shown in Figure 7B, the insulating layer 127 may not overlap with the pixel electrode and may be provided in the region sandwiched between the pixel electrode 111R and the pixel electrode 111G. In Figures 7A and 7B, part or all of the upper surface of the region (region 103) located outside the upper surface of the pixel electrode of the EL layer 113 is covered by the insulating layer 125 and the insulating layer 127. Even with such a configuration, the surface irregularities forming the common electrode 115 can be reduced and the coverage of the common electrode 115 can be improved compared to a configuration without insulating layers 125 and 127. Region 103 can be considered a dummy region.

[0167] Furthermore, as shown in Figure 8A, the upper surface of the insulating layer 127 may have a flat portion in a cross-sectional view of the display device.

[0168] Furthermore, as shown in Figure 8B, the upper surface of the insulating layer 127 may have a concave curved shape in a cross-sectional view of the display device. In Figure 8B, the upper surface of the insulating layer 127 has a shape that bulges gently towards the center, that is, a convex curved surface, and a shape that is concave in the center and its vicinity, that is, a concave curved surface. Also in Figure 8B, the convex curved portion of the upper surface of the insulating layer 127 is continuously connected to the tapered portion at the end. Even if the insulating layer 127 has such a shape, the common electrode 115 can be formed on the entire insulating layer 127 with good coverage.

[0169] One method for creating an insulating layer 127 with a concave curved surface in the center, as shown in Figure 8B, is exposure using a multi-gradation mask (typically a halftone mask or graytone mask). A multi-gradation mask is an exposure mask that allows exposure at three exposure levels: an exposed area, an intermediate exposed area, and an unexposed area, resulting in transmitted light of multiple intensities. This makes it possible to form an insulating layer 127 with multiple (typically two) thicknesses using only one photomask (a single exposure and development process).

[0170] The method for forming a concave curved surface in the central part of the insulating layer 127 is not limited to the above. For example, two photomasks may be used to create an exposed portion and an intermediate exposed portion separately. Alternatively, the viscosity of the resin material used for the insulating layer 127 may be adjusted. Specifically, the viscosity of the material used for the insulating layer 127 may be set to 10 cP or less, preferably 1 cP or more and 5 cP or less.

[0171] As described above, in each configuration shown in Figures 4 to 8, the common electrode 115 can be formed with good coverage by providing insulating layers 125 and 127. This prevents the formation of divided portions and locally thin film areas in the common electrode 115. Therefore, it is possible to suppress connection failures caused by divided portions and increases in electrical resistance caused by locally thin film areas in the common electrode 115 between each light-emitting device. As a result, the display device according to one embodiment of the present invention can improve display quality.

[0172] It is preferable to provide a protective layer 131 on the light-emitting devices 130R, 130G, and 130B. 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.

[0173] 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.

[0174] The presence of an inorganic film in the protective layer 131 prevents oxidation of the common electrode 115 and suppresses the intrusion of impurities (water, oxygen, etc.) into the light-emitting device, thereby suppressing degradation of the light-emitting device and improving the reliability of the display device.

[0175] For the protective layer 131, an inorganic insulating film such as an oxide insulating film, a nitride insulating film, an oxidoxide-nitriding insulating film, or a nitride-oxide insulating film can be used. Specific examples of these inorganic insulating films are given in the description of the sidewall insulating layer 114. In particular, the protective layer 131 preferably has a nitride insulating film or a nitride-oxide insulating film, and more preferably has a nitride insulating film.

[0176] 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.

[0177] 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.

[0178] 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 the penetration of impurities (water, oxygen, etc.) into the EL layer.

[0179] 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.

[0180] 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.

[0181] It is preferable to provide an insulating layer 135 on the protective layer 131. It is preferable to use a layer having a planarization function for the insulating layer 135. Using an organic film for the insulating layer 135 is preferable because it can improve the flatness of the surface of the insulating layer 135.

[0182] Organic materials that can be used for the protective layer 131 or insulating layer 135 include acrylic resins, polyimide resins, epoxy resins, imide resins, polyamide resins, polyimideamide resins, silicone resins, siloxane resins, benzocyclobutene resins, phenolic resins, and precursors of these resins. Alternatively, organic materials such as polyvinyl alcohol (PVA), polyvinyl butyral, polyvinylpyrrolidone, polyethylene glycol, polyglycerin, pullulan, water-soluble cellulose, or alcohol-soluble polyamide resins may be used as the protective layer 131 or insulating layer 135.

[0183] A light-shielding layer may be provided on the side of the substrate 120 facing the resin layer 122. Various optical components can be placed on the outside of the substrate 120 (the side opposite to the resin layer 122). Examples of optical components include polarizing plates, phase difference plates, light diffusion layers (such as diffusion films), anti-reflective layers, and light-collecting 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. xBy 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.

[0184] The substrate 120 can be made of glass, quartz, ceramics, 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 device. Alternatively, a polarizing plate may be used as the substrate 120.

[0185] 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.

[0186] Furthermore, when a circular polarizing plate is superimposed on a display device, it is preferable to use a substrate with high optical isotropy for the substrate of the display device. A substrate with high optical isotropy has low birefringence (or a small amount of birefringence).

[0187] 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.

[0188] Examples of films with high optical isotropy include triacetylcellulose (TAC, also known as cellulose triacetate) film, cycloolefin polymer (COP) film, cycloolefin copolymer (COC) film, and acrylic film.

[0189] Furthermore, when a film is used as the substrate, the film may absorb water, potentially causing wrinkles or other shape changes in the display device. Therefore, it is preferable to use a film with a low water absorption rate as the substrate. For example, it is preferable to use a film with a water absorption rate of 1% or less, more preferable to use a film with a water absorption rate of 0.1% or less, and even more preferable to use a film with a water absorption rate of 0.01% or less.

[0190] 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.

[0191] The thicknesses of the pixel electrodes 111R, 111G, and 111B may be different. Alternatively, as described later, optical adjustment layers of different thicknesses may be provided on the pixel electrodes 111R, 111G, and 111B.

[0192] Figure 9A shows a modified version of Figure 1B. Figures 9B and 9C are enlarged views of regions 150E and 150F shown in Figure 9A.

[0193] In Figure 9A, an optical adjustment layer 116R is provided on the pixel electrode 111R, an optical adjustment layer 116G is provided on the pixel electrode 111G, and an optical adjustment layer 116B is provided on the pixel electrode 111B.

[0194] Figure 9A shows an example where the thickness of optical adjustment layer 116R is greater than the thickness of optical adjustment layer 116G, and the thickness of optical adjustment layer 116G is greater than the thickness of optical adjustment layer 116B. Preferably, the thickness of optical adjustment layer 116R is set to enhance red light, the thickness of optical adjustment layer 116G is set to enhance green light, and the thickness of optical adjustment layer 116B is set to enhance blue light. This makes it possible to realize a microcavity structure and improve the color purity of the light emitted by each light-emitting device.

[0195] The optical adjustment layer is preferably formed using a conductive material that has transparency to visible light, among conductive materials that can be used as electrodes for light-emitting devices.

[0196] In the region 150E shown in Figures 9A and 9B, island-shaped EL layers 113 are provided on the pixel electrode 111R via an optical adjustment layer 116R, island-shaped EL layers 113 are provided on the pixel electrode 111G via an optical adjustment layer 116G, and a material layer 113s is provided on the insulating layer 255c. The EL layer 113 on the pixel electrode 111R, the EL layer 113 on the pixel electrode 111G, and the material layer 113s are isolated from each other.

[0197] In the region 150F shown in Figures 9A and 9C, an island-shaped EL layer 113 is provided on the pixel electrode 111G via an optical adjustment layer 116G, and the island-shaped EL layer 113 is provided so as to cover the insulating layer 255c, the side wall insulating layer 114 (on the pixel electrode 111B side), the pixel electrode 111B, and the optical adjustment layer 116B. The EL layer 113 on the pixel electrode 111G and the EL layer 113 covering the insulating layer 255c, the side wall insulating layer 114 (on the pixel electrode 111B side), and the pixel electrode 111B are isolated from each other.

[0198] Because the thickness of the optical adjustment layer differs depending on the sub-pixel, the height of the sidewall insulating layer 114 may also differ depending on the sub-pixel. In Figures 9B and 9C, the height T3 of the sidewall insulating layer 114 covering the side of the pixel electrode 111R is greater than the height T4 of the sidewall insulating layer 114 covering the side of the pixel electrode 111G and the height T5 of the sidewall insulating layer 114 covering the side of the pixel electrode 111B, and the height T4 of the sidewall insulating layer 114 covering the side of the pixel electrode 111G is greater than the height T5 of the sidewall insulating layer 114 covering the side of the pixel electrode 111B.

[0199] As shown in Figure 9C, depending on the value of height T5, the EL layer 113 may not be divided by the sidewall insulating layer 114 covering the side of the pixel electrode 111B, and a single island-shaped EL layer 113 may have a portion located on the insulating layer 255c, a portion covering the sidewall insulating layer 114 (on the pixel electrode 111B side), and a portion covering the upper surface of the pixel electrode 111B. However, in Figure 9C, the EL layer 113 is divided by the sidewall insulating layer 114 covering the side of the pixel electrode 111G. In other words, since island-shaped EL layers are provided independently between adjacent light-emitting devices, the occurrence of crosstalk between adjacent subpixels can be suppressed.

[0200] Furthermore, depending on the value of height T4, the EL layer 113 may not be divided even by the sidewall insulating layer 114 covering the side of the pixel electrode 111G. In other words, a single island-shaped EL layer 113 may cover the insulating layer 255c, the sidewall insulating layer 114 in contact with the pixel electrode 111G, the top surface of the pixel electrode 111G, the sidewall insulating layer 114 in contact with the pixel electrode 111B, and the top surface of the pixel electrode 111B. In this case, the portion of the EL layer 113 covering the sidewall insulating layer 114 is thinner than other portions, so the electrical resistance of this thinned portion becomes higher than other portions, and the leakage current between adjacent light-emitting devices can be reduced. Therefore, even in a configuration where the EL layer 113 is connected between adjacent light-emitting devices as described above, the occurrence of crosstalk between adjacent subpixels can be suppressed.

[0201] Thus, a configuration in which the EL layer 113 is formed in an island-like manner in some light-emitting devices, and the EL layer 113 is a continuous layer in multiple other light-emitting devices, is also one aspect of the present invention. For example, a display device according to one aspect of the present invention may have a configuration that includes both the region 150A shown in Figure 3A and the region 150B shown in Figure 3B.

[0202] Figures 1B and 9A show an example in which the colored layers 132R, 132G, and 132B are directly provided on the light-emitting device via a protective layer 131 and an insulating layer 135. This configuration improves the accuracy of the alignment between the light-emitting device and the colored layers. Furthermore, bringing the light-emitting device and the colored layers closer together suppresses color mixing and improves viewing angle characteristics, which is preferable.

[0203] Figures 10, 11A, 11B, 12A, and 12B show modified examples of Figure 1B.

[0204] As shown in Figure 10, the substrate 120, which has the colored layers 132R, 132G, and 132B, may be bonded to the protective layer 131 by the resin layer 122. By providing the substrate 120 with the colored layers 132R, 132G, and 132B, the temperature of the heat treatment in the formation process of the colored layers 132R, 132G, and 132B can be increased.

[0205] As shown in Figures 11A and 11B, a lens 133 may be provided in the display device. It is preferable to provide the lens 133 on top of the light-emitting device. By providing the lens 133, the light emitted by the light-emitting device can be extracted to the outside of the display device more efficiently than if the lens 133 were not provided.

[0206] Figure 11A shows an example in which a colored layer 132R, a colored layer 132G, and a colored layer 132B are provided on the light-emitting device via a protective layer 131 and an insulating layer 135, an insulating layer 134 is provided on the colored layers 132R, 132G, and 132B, and a lens 133 is provided on the insulating layer 134. By directly forming the colored layers 132R, 132G, 132B, and the lens 133 on the substrate on which the light-emitting device is formed, the accuracy of the alignment between the light-emitting device and the colored layers or the lens 133 can be improved.

[0207] The insulating layer 134 can be an inorganic insulating film, an organic insulating film, or both. The insulating layer 134 may be a single-layer structure or a multi-layer structure. For example, the insulating layer 134 can be made of a material that can be used for the protective layer 131. It is preferable that the insulating layer 134 has a planarization function. Since the light emitted from the light-emitting device is extracted through the insulating layer 134, it is preferable that the insulating layer 134 has high transmittance to visible light.

[0208] In Figure 11A, the light emitted from the light-emitting device passes through the colored layer, then through the lens 133, and is extracted to the outside of the display device. Bringing the light-emitting device and the colored layer closer together is preferable because it can suppress color mixing and improve viewing angle characteristics. Alternatively, the lens 133 may be provided on the light-emitting device, and the colored layer may be provided on the lens 133.

[0209] Figure 11B shows an example in which a substrate 120, on which colored layers 132R, 132G, 132B, and a lens 133 are provided, is bonded to a protective layer 131 by a resin layer 122. By providing the substrate 120 with the colored layers 132R, 132G, 132B, and lens 133, the temperature of the heat treatment in the formation process can be increased.

[0210] Figure 11B shows an example in which a colored layer 132R, a colored layer 132G, and a colored layer 132B are provided in contact with the substrate 120, an insulating layer 134 is provided in contact with the colored layers 132R, 132G, and 132B, and a lens 133 is provided in contact with the insulating layer 134.

[0211] In Figure 11B, the light emitted from the light-emitting device passes through the lens 133, then through the colored layer, and is extracted to the outside of the display device. Alternatively, the lens 133 may be provided in contact with the substrate 120, the insulating layer 134 in contact with the lens 133, and the colored layer in contact with the insulating layer 134. In this case, the light emitted from the light-emitting device passes through the colored layer, then through the lens 133, and is extracted to the outside of the display device.

[0212] As shown in Figures 12A and 12B, one of the lens and the colored layer may be provided on the insulating layer 135, and the other on the substrate 120.

[0213] Figure 12A shows an example in which a lens 133 is provided on a light-emitting device via a protective layer 131 and an insulating layer 135, and a substrate 120 having colored layers 132R, 132G, and 132B is bonded to the lens 133 and the insulating layer 135 by a resin layer 122.

[0214] Figure 12B shows an example in which a light-emitting device has colored layers 132R, 132G, and 132B provided on it via a protective layer 131 and an insulating layer 135, and a substrate 120 on which a lens 133 is provided is bonded to the colored layers 132R, 132G, and 132B by a resin layer 122.

[0215] The lens 133 is preferably a lens (also called a plano-convex lens) having a convex surface and a flat surface on the opposite side of the convex surface. The convex surface of the lens 133 may face either the substrate 120 side or the light-emitting device side, but from the viewpoint of ease of manufacturing, when the lens 133 is provided on the light-emitting device side, as shown in Figures 11A and 12A, it is preferable to provide it so that the convex surface faces the substrate 120 side. On the other hand, when the lens 133 is provided on the substrate 120 side, as shown in Figures 11B and 12B, it is preferable to provide it so that the convex surface faces the light-emitting device side.

[0216] The lens 133 can be formed using at least one of an inorganic material and an organic material. For example, a material containing resin can be used for the lens 133. Alternatively, a material containing at least one of an oxide and a sulfide can be used for the lens 133. Preferably, the lens 133 is formed using a material with a refractive index greater than that of the resin layer 122. As the lens 133, for example, a microlens array can be used. The lens 133 may be formed directly on the substrate or on the light-emitting device, or a separately formed lens may be bonded to it.

[0217] Furthermore, it is preferable that the colored layers of different colors overlap. The overlapping regions of the colored layers can function as a light-shielding layer. This further reduces external light reflection.

[0218] Figure 13A shows a schematic cross-sectional view of the display device illustrated below. The display device has sub-pixels 154R, 154G, and 154B.

[0219] Sub-pixels 154R, 154G, and 154B each have light-emitting devices 137R, 137G, and 137B, respectively. Light-emitting devices 137R, 137G, and 137B differ from light-emitting devices 130R, 130G, and 130B in that they have an EL layer 113B instead of an EL layer 113. Furthermore, a material layer 113b is provided on the insulating layer 255c in the region between pixel electrode 111R and pixel electrode 111G. Similarly, a material layer 113b is provided on the insulating layer 255c in the region between pixel electrode 111G and pixel electrode 111B, and in the region between pixel electrode 111B and pixel electrode 111R. Material layer 113b is formed in the same process as EL layer 113B, has the same structure, and corresponds to material layer 113s shown in Figure 1B, etc. EL layer 113B has a light-emitting material that emits blue light, violet light, or ultraviolet light. Therefore, light-emitting devices 137R, 137G, and 137B all emit blue light, violet light, or ultraviolet light.

[0220] Furthermore, the sub-pixel 154R has a color conversion layer 175R and a coloring layer 132R on the optical path of the light emitted by the light-emitting device 137R. The color conversion layer 175R has the function of absorbing the light emitted by the light-emitting device 137R and emitting red light.

[0221] The sub-pixel 154G has a color conversion layer 175G and a coloring layer 132G on the optical path of the light emitted by the light-emitting device 137G. The color conversion layer 175G has the function of absorbing the light emitted by the light-emitting device 137G and emitting green light.

[0222] A light-emitting device 137B is provided in the sub-pixel 154B. When a light-emitting device that emits purple or ultraviolet light is used as the light-emitting device 137B, it is preferable to place either or both of the following on the optical path of the light-emitting device 137B: a colored layer that transmits blue light, and a color conversion layer that absorbs the light emitted by the light-emitting device 137B and emits blue light.

[0223] For the color conversion layer 175R and color conversion layer 175G, for example, fluorescent materials, phosphorescent materials, or resin materials in which quantum dots are dispersed can be used, respectively.

[0224] The colored layers 132R and 132G each have the function of absorbing blue or violet light transmitted through the color conversion layer. This makes it possible to increase the color purity of the light emitted by each sub-pixel, thereby realizing a display device with high display quality. Alternatively, a colored layer that transmits blue light may be provided on the sub-pixel 154B.

[0225] The display device shown in Figure 13B has sub-pixels 155R, 155G, and 155B.

[0226] The sub-pixel 155R comprises a light-emitting device 130R, a color conversion layer 175R, and a coloring layer 132R. As mentioned above, the light-emitting device 130R is a light-emitting device that emits white light. The color conversion layer 175R has the function of absorbing light with a shorter wavelength than red light from the white light emitted by the light-emitting device 130R and emitting red light. The coloring layer 132R has the function of transmitting red light and absorbing other visible light.

[0227] The sub-pixel 155G comprises a light-emitting device 130G, a color conversion layer 175G, and a colored layer 132G. As mentioned above, the light-emitting device 130G is a light-emitting device that emits white light. The color conversion layer 175G has the function of absorbing light with a shorter wavelength than green light from the white light emitted by the light-emitting device 130G and emitting green light. The colored layer 132G has the function of transmitting green light and absorbing other visible light.

[0228] The sub-pixel 155B includes a light-emitting device 130B and a colored layer 132B. As mentioned above, the light-emitting device 130B is a light-emitting device that emits white light. The colored layer 132B has the function of transmitting blue light from the white light emitted by the light-emitting device 130B and absorbing the other visible light.

[0229] In this way, by applying a color conversion layer to the red and green subpixels, it is possible to reuse the light emitted from the white light-emitting device that would normally be absorbed by the colored layer. Therefore, it is possible to improve the luminous efficiency compared to a configuration that does not use a color conversion layer.

[0230] Figures 13A and 13B show an example in which a light-shielding layer 171 is provided on the insulating layer 135 in a portion that overlaps with the insulating layer 127. In a plan view, the light-shielding layer 171 is preferably provided between adjacent light-emitting devices. With this configuration, the light-shielding layer 171 can block light mixed between adjacent color conversion layers, preventing the mixed light from being emitted to the outside. The light-shielding layer 171 preferably contains a material that absorbs at least a portion of visible light. For example, the light-shielding layer 171 itself may be made of a material that absorbs visible light (e.g., a colored organic or inorganic material), or the light-shielding layer 171 may contain a pigment that absorbs visible light. As the light-shielding layer 171, for example, a resin containing carbon black as a pigment and functioning as a black matrix, or a resin that can be used as a color filter that transmits red, blue, or green light and absorbs other light can be used.

[0231] In addition, a display device according to one aspect of the present invention may have a configuration that does not include a light-shielding layer 171. In this case, it is preferable that the configuration is such that the edges of adjacent colored layers overlap, as shown in Figure 1B, etc.

[0232] In one embodiment of the present invention, the EL layer is partially thinned, or the EL layer is provided in an island-like manner for each light-emitting device, thereby suppressing the generation of leakage current between subpixels. This prevents unintended light emission caused by crosstalk, and enables the realization of a display device with extremely high contrast.

[0233] Furthermore, in a display device according to one aspect of the present invention, a sidewall insulating layer is provided on the side surface of the pixel electrode. This suppresses short circuits in the light-emitting device and enables the realization of a highly reliable display device.

[0234] Furthermore, in a display device according to one aspect of the present invention, an insulating layer is provided so as to cover at least a part of the upper surface and sides of the island-shaped EL layer. A common electrode is then provided so as to cover the insulating layer and the EL layer. This makes it possible to suppress the common electrode from being cut off due to the step difference between adjacent pixel electrodes, thereby further improving the manufacturing yield of the light-emitting device.

[0235] This embodiment can be combined with other embodiments as appropriate. Furthermore, if multiple configuration examples are shown within a single embodiment in this specification, these configuration examples can be combined as appropriate.

[0236] (Embodiment 2) In this embodiment, a method for manufacturing a display device according to one aspect of the present invention will be described with reference to Figures 14 to 16. Note that descriptions of the materials and formation methods of each element may be omitted if they are the same as those described in Embodiment 1. Furthermore, the details of the configuration of the light-emitting device will be described in Embodiment 5.

[0237] Figures 14A to 14E, 15A to 15D, 16E, and 16F show side-by-side cross-sectional views of the section between dashed lines X1 and X2 shown in Figure 1A, and cross-sectional views of the section between dashed lines Y1 and Y2.

[0238] Thin films (insulating films, semiconductor films, conductive films, etc.) that constitute display devices can be formed using sputtering, CVD, vacuum deposition, pulsed laser deposition (PLD), ALD, and other methods. CVD methods include PECVD and thermal CVD. One type of thermal CVD is metal-organic chemical vapor deposition (MOCVD).

[0239] Furthermore, thin films (insulating films, semiconductor films, conductive films, etc.) that constitute the display device can be formed by wet film deposition methods such as spin coating, dip coating, spray coating, inkjet printing, dispensing, screen printing, offset printing, doctor knife coating, slit coating, roll coating, curtain coating, or knife coating.

[0240] 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, hole blocking layer, light-emitting layer, electron blocking layer, electron transport layer, electron injection layer, charge generation 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.).

[0241] Furthermore, when processing the thin film that constitutes the display device, 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.

[0242] 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 finally removing the resist mask. The other method involves depositing a photosensitive thin film, then exposing and developing it to process the thin film into the desired shape.

[0243] In photolithography, the light used for exposure can be, for example, i-line (wavelength 365 nm), g-line (wavelength 436 nm), h-line (wavelength 405 nm), or a mixture thereof. Other light sources such as ultraviolet light, KrF laser light, or ArF laser light can also be used. Exposure may also be performed using immersion lithography. Furthermore, extreme ultraviolet (EUV) light or X-rays may be used as the light source for exposure. An electron beam can also be used instead of the light source for exposure. Using extreme ultraviolet light, X-rays, or an electron beam is preferable because it enables extremely fine processing. Note that a photomask is not required when exposure is performed by scanning a beam such as an electron beam.

[0244] For etching thin films, methods such as dry etching, wet etching, and sandblasting can be used.

[0245] First, insulating layers 255a, 255b, and 255c are formed on layer 101 in that order. Subsequently, pixel electrodes 111R, 111G, 111B, and a conductive layer 123 are formed on insulating layer 255c (Figure 14A).

[0246] First, a conductive film to be used as a pixel electrode is deposited on the insulating layer 255c, a resist mask is formed on the conductive film by photolithography, and unnecessary portions of the conductive film are removed by etching. Subsequently, the resist mask is removed to form the pixel electrode 111R, pixel electrode 111G, pixel electrode 111B, and conductive layer 123. For depositing the conductive film to be used as a pixel electrode, for example, sputtering or vacuum deposition can be used. The conductive film can be processed by wet etching or dry etching. It is preferable to process the conductive film by anisotropic etching.

[0247] When processing the conductive film, it is preferable to process the insulating layer 255c to form a recess in the insulating layer 255c. This makes it possible to increase the height of the side wall insulating layer 114 that is formed later. Therefore, it becomes easier to partially thin the EL layer 113 that is formed later, or to divide the EL layer 113 for each light-emitting device. Other configurations in one aspect of the present invention include a configuration in which an opening is provided in the insulating layer 255c and a recess is provided in the insulating layer 255b, and a configuration in which openings are provided in the insulating layer 255b and insulating layer 255c and a recess is provided in the insulating layer 255a. Furthermore, in cases where the pixel electrode is sufficiently thick, it may not be necessary to provide recesses and openings in the insulating layer 255c.

[0248] In other words, it is preferable that the thickness of the insulating layer 255c in the region that does not overlap with any of the pixel electrodes 111R, 111G, 111B, or the conductive layer 123 is thinner than the thickness of the insulating layer 255c in the region that overlaps with the pixel electrodes 111R, 111G, 111B, or the conductive layer 123.

[0249] Next, an insulating film 114A is formed on the insulating layer 255c, pixel electrode 111R, pixel electrode 111G, pixel electrode 111B, and conductive layer 123 (Figure 14B).

[0250] The insulating film 114A is a film that will later be processed to become the sidewall insulating layer 114. Therefore, the configuration applicable to the sidewall insulating layer 114 described in Embodiment 1 can be applied to the insulating film 114A.

[0251] Next, the insulating film 114A is processed to form the sidewall insulating layer 114 (Figure 14C). Processing the insulating film 114A exposes the upper surfaces of the insulating layer 255c, the pixel electrode 111R, the pixel electrode 111G, the pixel electrode 111B, and the conductive layer 123. The sidewall insulating layer 114 is provided so as to be in contact with the sides of the pixel electrode 111R, the pixel electrode 111G, the pixel electrode 111B, and the conductive layer 123.

[0252] For example, the sidewall insulating layer 114 can be formed by etching the upper surface of the insulating film 114A in a substantially uniform manner. This process of uniform etching and planarization is also called etch-back treatment. The sidewall insulating layer 114 can also be formed using photolithography.

[0253] The insulating film 114A can be processed by wet etching or dry etching, with dry etching being preferred. The processing of the insulating film 114A is preferably carried out by anisotropic etching.

[0254] Furthermore, when processing the insulating film 114A, the insulating layer 255c may also be processed to form recesses in the insulating layer 255c. Forming recesses in the insulating layer 255c makes it easier to partially thin the EL layer 113 that is formed later, or to divide the EL layer 113 for each light-emitting device. Other configurations in one aspect of the present invention include a configuration in which an opening is provided in the insulating layer 255c and a recess is provided in the insulating layer 255b, and a configuration in which openings are provided in the insulating layer 255b and insulating layer 255c, and a recess is provided in the insulating layer 255a. In addition, in cases where the pixel electrode is sufficiently thick, it may be necessary not to provide recesses and openings in the insulating layer 255c.

[0255] In other words, in the insulating layer 255c shown in Figure 14C, the film thickness of the exposed region (the region that does not overlap with the sidewall insulating layer 114, pixel electrode 111R, pixel electrode 111G, pixel electrode 111B, and conductive layer 123) may be thinner than the film thickness of the region that overlaps with the sidewall insulating layer 114 (see Figure 3D).

[0256] The edges of the sidewall insulating layer 114 can be rounded. For example, when forming the sidewall insulating layer 114, if a dry etching method is used and the upper part of the insulating film 114A is etched by anisotropic etching, the edges of the sidewall insulating layer 114 will be rounded, as shown in Figures 14C, 1B, 3A to 3D, etc. Rounding the edges of the sidewall insulating layer 114 is preferable because it improves the coverage of the film formed later.

[0257] Next, the EL layer 113 is formed on the pixel electrode 111R, pixel electrode 111G, and pixel electrode 111B (Figure 14D). The EL layer 113 includes a light-emitting material that emits blue light and a light-emitting material that emits light with a longer wavelength than blue. Figure 14D shows an example in which island-shaped EL layers 113 are provided for each light-emitting device. That is, island-shaped EL layers 113 are provided on the pixel electrode 111R, pixel electrode 111G, and pixel electrode 111B, respectively.

[0258] In the region between pixel electrode 111R and pixel electrode 111G, a material layer 113s is provided on the insulating layer 255c. Similarly, in the region between pixel electrode 111G and pixel electrode 111B, and in the region between pixel electrode 111B and pixel electrode 111R, a material layer 113s is also provided on the insulating layer 255c. The material layer 113s is formed in the same process as the EL layer 113 and has the same configuration.

[0259] As shown in Figure 14D, in the cross-sectional view between the dashed-dotted line Y1-Y2, the EL layer 113 is not formed on the conductive layer 123. For example, by using an area mask, the EL layer 113 can be deposited only in a desired region.

[0260] The EL layer 113 can be formed, for example, by a vapor deposition method, specifically by a vacuum vapor deposition method. Alternatively, the EL layer 113 may be formed by methods such as a transfer method, a printing method, an inkjet method, or a coating method.

[0261] Next, an insulating film 125A, which will later become the insulating layer 125, is formed to cover the EL layer 113, the side wall insulating layer 114, and the material layer 113s (Figure 14E).

[0262] As described later, the insulating film 127a is formed in contact with the upper surface of the insulating film 125A. For this reason, it is preferable that the upper surface of the insulating film 125A has high adhesion to the resin composition used for the insulating film 127a (for example, a photosensitive resin composition containing acrylic resin). To improve this adhesion, it is preferable to hydrophobize (or increase the hydrophobicity of) the upper surface of the insulating film 125A by performing a surface treatment. For example, it is preferable to perform the treatment using a silylation agent such as hexamethyldisilazane (HMDS). By hydrophobizing the upper surface of the insulating film 125A in this way, the insulating film 127a can be formed with good adhesion.

[0263] Next, an insulating film 127a is formed on the insulating film 125A (Figure 15A).

[0264] It is preferable that the insulating film 125A and insulating film 127a are formed using a method that causes minimal damage to the EL layer 113. In particular, since insulating film 125A is formed in contact with the surface of the EL layer 113, it is preferable that it be formed using a method that causes less damage to the EL layer 113 than insulating film 127a.

[0265] Furthermore, insulating film 125A and insulating film 127a are formed at a temperature lower than the heat resistance temperature of the EL layer 113. In addition, by increasing the substrate temperature during film formation of insulating film 125A, it is possible to create a film with a low impurity concentration and high barrier properties against at least one of water and oxygen, even with a thin film thickness.

[0266] The substrate temperature when forming insulating film 125A and insulating film 127a is preferably 60°C or higher, 80°C or higher, 100°C or higher, or 120°C or higher, and 200°C or lower, 180°C or lower, 160°C or lower, 150°C or lower, or 140°C or lower, respectively.

[0267] As described above, in one embodiment of the present invention, a heat-resistant material is used for the light-emitting device. Therefore, the substrate temperature when forming the insulating film 125A and insulating film 127a can be set to 100°C or higher, 120°C or higher, or 140°C or higher, respectively. For example, the higher the deposition temperature of the inorganic insulating film, the denser and more barrier-oriented the film can be. Therefore, by depositing the insulating film 125A at such a temperature, the damage to the EL layer 113 during deposition can be further reduced, and the reliability of the light-emitting device can be improved.

[0268] As the insulating film 125A, it is preferable to form an insulating film with a thickness of 3 nm or more, 5 nm or more, or 10 nm or more, and a thickness of 200 nm or less, 150 nm or less, 100 nm or less, or 50 nm or less, within the above substrate temperature range.

[0269] The insulating film 125A is preferably formed 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 highly covering film. For example, it is preferable to form an aluminum oxide film as the insulating film 125A using the ALD method.

[0270] In addition, the insulating film 125A may be formed using sputtering, CVD, or PECVD, which have faster deposition rates than the ALD method. This allows for the production of highly reliable display devices with high productivity.

[0271] The insulating film 127a is preferably formed using the wet film formation method described above. The insulating film 127a is preferably formed using a photosensitive resin, for example, by spin coating, and more specifically, it is preferably formed using a photosensitive resin composition containing an acrylic resin.

[0272] Furthermore, it is preferable to perform a heat treatment (also called pre-baking) after the formation of the insulating film 127a. This heat treatment is performed at a temperature lower than the heat resistance temperature of the EL layer 113. The substrate temperature during the heat treatment is preferably 50°C to 200°C, more preferably 60°C to 150°C, and even more preferably 70°C to 120°C. This makes it possible to remove the solvent contained in the insulating film 127a.

[0273] Next, visible light or ultraviolet light is irradiated onto a portion of the insulating film 127a to expose that portion (Figure 15B). Here, if a positive-type photosensitive resin composition containing acrylic resin is used for the insulating film 127a, visible light or ultraviolet light is irradiated onto the area where the insulating layer 127 will not be formed in a later step using a mask 136. The insulating layer 127 is formed in the area sandwiched between any two of the pixel electrodes 111R, 111G, and 111B, and in the area surrounding the conductive layer 123. Therefore, as shown in Figure 15B, light 139 is irradiated onto the portion of the insulating film 127a that overlaps with the pixel electrode 111R, the portion that overlaps with the pixel electrode 111G, the portion that overlaps with the pixel electrode 111B, and the portion that overlaps with the conductive layer 123.

[0274] Furthermore, the width of the insulating layer 127 to be formed later can be controlled by the area exposed to light at this stage. In this embodiment, the insulating layer 127 is processed so that it has a portion that overlaps with the upper surface of the pixel electrode (Figure 4A). As shown in Figure 7A or Figure 7B, the insulating layer 127 does not have to have a portion that overlaps with the upper surface of the pixel electrode.

[0275] The light used for exposure preferably includes the i-line (wavelength 365 nm). Furthermore, the light used for exposure may also include at least one of the g-line (wavelength 436 nm) and the h-line (wavelength 405 nm).

[0276] Note that, in FIG. 15B, an example is illustrated in which a positive photosensitive resin is used for the insulating film 127a, and a region where the insulating layer 127 is not formed is irradiated with visible light or ultraviolet light. However, the present invention is not limited thereto. For example, a configuration may be adopted in which a negative photosensitive resin is used for the insulating film 127a. In this case, the mask is changed, and a region where the insulating layer 127 is to be formed is irradiated with visible light or ultraviolet light.

[0277] Subsequently, as shown in FIG. 15C, development is performed to remove the exposed region of the insulating film 127a, thereby forming an insulating layer 127b. The insulating layer 127b is formed in a region sandwiched between any two of the pixel electrode 111R, the pixel electrode 111G, and the pixel electrode 111B, and in a region surrounding the conductive layer 123. Here, when an acrylic resin is used for the insulating film 127a, it is preferable to use an alkaline solution as the developer, and for example, a tetramethylammonium hydroxide aqueous solution (TMAH) can be used.

[0278] Note that after development, a step of removing residues (so-called scum) generated during development may be performed. For example, the residues can be removed by performing ashing using oxygen plasma. A step of removing residues may also be performed after each of the development steps described below.

[0279] Note that etching may be performed to adjust the surface height of the insulating layer 127b. The insulating layer 127b may be processed, for example, by ashing using oxygen plasma.

[0280] Note that after development and before post-baking, exposure may be performed to irradiate the insulating layer 127b with visible light or ultraviolet light. The energy density of the exposure is 0 mJ / cm 2 greater than 800 mJ / cm 2 or less, and it is preferably 0 mJ / cm 2 greater than 500 mJ / cm 2The following is more preferable: Performing such exposure after development may improve the transparency of the insulating layer 127b. In addition, it may be possible to deform the insulating layer 127b into a tapered shape at a low temperature.

[0281] On the other hand, by not exposing the insulating layer 127b, it may be easier to change the shape of the insulating layer 127b or to deform the insulating layer 127 into a tapered shape in a later process. Therefore, it may be preferable not to expose the insulating layer 127b after development.

[0282] Next, after forming the insulating layer 127b, a heat treatment (also called post-bake) is performed. As shown in Figure 15D, by performing the heat treatment, the insulating layer 127b can be deformed into an insulating layer 127 having a tapered shape on its side surface. This heat treatment is performed at a temperature lower than the heat resistance temperature of the EL layer 113. 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 130°C. The heating atmosphere may be an atmospheric atmosphere or an inert gas atmosphere. The heating atmosphere may also be an atmospheric pressure atmosphere or a reduced pressure atmosphere. A reduced pressure atmosphere is preferable because it allows drying at a lower temperature. It is preferable to use a higher substrate temperature for the heat treatment in this step than for the heat treatment after forming the insulating film 127a (pre-bake). This improves the adhesion between the insulating layer 127 and the insulating layer 125, and also improves the corrosion resistance of the insulating layer 127.

[0283] Furthermore, depending on the material of the insulating layer 127, as well as the post-bake temperature, time, and atmosphere, a concave curved shape may be formed on the side surface of the insulating layer 127, as shown in Figures 6A and 6B. For example, the higher the temperature or the longer the post-bake conditions, the more likely the shape of the insulating layer 127 is to change, and a concave curved shape may be formed in cross-sectional view. Also, as mentioned above, if the insulating layer 127b is not exposed after development, the shape of the insulating layer 127 may change during post-bake.

[0284] Next, as shown in Figure 15D, etching is performed using the insulating layer 127 as a mask to remove a portion of the insulating film 125A. This creates an opening in the insulating film 125A (i.e., the insulating layer 125 is formed), exposing the upper surfaces of the EL layer 113 and the conductive layer 123.

[0285] Etching can be performed by dry etching or wet etching.

[0286] When using the dry etching method, it is preferable to use a chlorine-based gas. As chlorine-based gases, Cl2, BCl3, SiCl4, CCl4, etc., can be used individually or in mixtures of two or more gases. In addition, oxygen gas, hydrogen gas, helium gas, argon gas, etc., can be added individually or in mixtures of two or more gases as appropriate to the above chlorine-based gas. By using the dry etching method, regions with a thin film thickness of the insulating layer 125 can be formed with good in-plane uniformity.

[0287] Furthermore, when using the dry etching method, by-products generated during dry etching may accumulate on the upper and side surfaces of the insulating layer 127. Therefore, components contained in the etching gas and components contained in the insulating film 125A may be present in the insulating layer 127 after the display device is completed.

[0288] Furthermore, it is preferable to perform the etching process using a wet etching method. By using a wet etching method, the damage to the EL layer 113 can be reduced compared to when a dry etching method is used. For example, a wet etching method can be performed using an alkaline solution. For example, for wet etching of an aluminum oxide film, it is preferable to use an aqueous solution of tetramethylammonium hydroxide (TMAH), which is an alkaline solution. In this case, wet etching can be performed using a paddle method.

[0289] As described above, by providing insulating layers 125 and 127, connection failures caused by interrupted portions and increases in electrical resistance caused by locally thin film thicknesses can be suppressed between each light-emitting device in the common electrode 115. As a result, the display device according to one embodiment of the present invention can improve display quality. Furthermore, the manufacturing yield of the light-emitting devices can be increased.

[0290] Furthermore, after exposing a portion of the EL layer 113, further heat treatment may be performed. This heat treatment can remove water contained in the EL layer 113 and water adsorbed on the surface of the EL layer 113. Also, this heat treatment may change the shape of the insulating layer 127. Specifically, the insulating layer 127 may spread to cover at least one of the edges of the insulating layer 125 and the upper surface of the EL layer 113. For example, the insulating layer 127 may take on the shape shown in Figures 5A and 5B. For example, the heat treatment can be performed in an inert gas atmosphere or a reduced pressure atmosphere. The heat treatment can be performed at a substrate temperature of 50°C to 200°C, preferably 60°C to 150°C, and more preferably 70°C to 120°C. A reduced pressure atmosphere is preferable because it allows for dehydration at a lower temperature. However, it is preferable to appropriately set the temperature range for the above heat treatment, taking into account the heat resistance temperature of the EL layer 113. Furthermore, considering the heat resistance temperature of the EL layer 113, a temperature range of 70°C to 120°C is particularly preferred within the above temperature range.

[0291] If the insulating layer 125 is etched all at once after post-baking, side etching may cause the insulating layer 125 beneath the edge of the insulating layer 127 to disappear, forming a cavity. This cavity can cause unevenness on the surface forming the common electrode 115, making the common electrode 115 prone to step breaks. Therefore, it is preferable to perform the etching of the insulating layer 125 in two separate steps, before and after post-baking.

[0292] In the following section, a method for etching the insulating layer 125, performed separately before and after post-baking, will be described using Figures 16A to 16D.

[0293] First, Figure 16A shows an enlarged view of the EL layer 113 and the edge and vicinity of the insulating layer 127b, as shown in Figure 15C. In other words, Figure 16A shows the insulating layer 127b formed by development.

[0294] Next, as shown in Figure 16B, etching is performed using the insulating layer 127b as a mask to remove a portion of the insulating film 125A and thin a portion of the insulating film 125A. As a result, the insulating layer 125B is formed beneath the insulating layer 127b. In the following, the etching process using the insulating layer 127b as a mask may be referred to as the first etching process.

[0295] The first etching process can be carried out by a dry etching method or a wet etching method.

[0296] As shown in Figure 16B, by etching using the insulating layer 127b, which has a tapered side surface, as a mask, an insulating layer 125B having a tapered shape on a portion of its upper surface can be formed relatively easily.

[0297] As shown in Figure 16B, in the first etching process, the thin portion of the insulating layer 125B (the portion that does not overlap with the insulating layer 127b) is not completely removed, and the etching process is stopped in this state. By leaving the insulating layer 125B on the EL layer 113 in this way, it is possible to prevent damage to the EL layer 113 in subsequent processing steps.

[0298] Figure 16B shows an example where the shape of the insulating layer 127b is unchanged from that in Figure 16A, but the present invention is not limited to this. For example, the edges of the insulating layer 127b may droop and come into contact with the upper surface of the insulating layer 125B. As mentioned above, if the insulating layer 127b is not exposed to light after development, the shape of the insulating layer 127b may change easily.

[0299] Subsequently, post-baking is performed. As shown in FIG. 16C, performing post-baking can transform the insulating layer 127b into the insulating layer 127 having a tapered shape on the side surface. Note that as described above, when the first etching process is completed, the shape of the insulating layer 127b may have already changed, and the side surface may have a tapered shape.

[0300] In the first etching process, by not completely removing the thin-film portion of the insulating layer 125B and leaving the insulating layer 125B in this state, it is possible to prevent the EL layer 113 from being damaged and degraded by post-baking. Accordingly, the reliability of the light-emitting device can be improved.

[0301] Subsequently, as shown in FIG. 16D, with the insulating layer 127 used as a mask, an etching process is performed to remove a portion (the thin-film portion) of the insulating layer 125B. Accordingly, an opening is formed in the insulating layer 125B (that is, the insulating layer 125 is formed), and upper surfaces of the EL layer 113 and the conductive layer 123 are exposed. Hereinafter, the etching process using the insulating layer 127 as a mask may be referred to as the second etching process.

[0302] FIG. 16D shows an example in which the insulating layer 127 covers a part of an end portion of the insulating layer 125 (specifically, the tapered portion formed by the first etching process), and the tapered portion formed by the second etching process is exposed. That is, this corresponds to the structures shown in FIGS. 4A and 4B.

[0303] As described above, when etching is performed before and after post-bake, the insulating film 125A may be side-etched in the first etching process (i.e., the insulating layer 125B is formed), and a cavity may be created beneath the edge of the insulating layer 127b. However, by performing post-bake afterward, the insulating layer 127b can be deformed into an insulating layer 127 having a tapered shape on its side. This allows the insulating layer 127 to fill the aforementioned cavity. Subsequently, in the second etching process, only the thin portion of the insulating layer 125B (i.e., the portion that does not overlap with the insulating layer 127) is etched, so the amount of side etching is reduced, making it less likely for cavities to form, and even if cavities do form, they can be made extremely small. Therefore, the surface on which the common electrode 115 is formed can be made flatter.

[0304] In the above example, the insulating layer 125 is formed by etching the insulating film 125A in two separate steps, but this is not limited to this method. Depending on the thickness of the insulating film 125A, or the etching conditions, the insulating layer 125 may be formed by etching the insulating film 125A in a single step.

[0305] As shown in Figures 5A, 6B, and 7B, the insulating layer 127 may cover the entire edge of the insulating layer 125. For example, the edge of the insulating layer 127 may droop and cover the edge of the insulating layer 125. Also, for example, the edge of the insulating layer 127 may be in contact with the upper surface of the EL layer 113. As mentioned above, if the insulating layer 127b is not exposed after development, the shape of the insulating layer 127 may change easily.

[0306] The second etching process is preferably carried out by a wet etching method. By using a wet etching method, the damage to the EL layer 113 can be reduced compared to when a dry etching method is used. The wet etching method can be carried out using an alkaline solution or the like.

[0307] Next, a common electrode 115 is formed on the EL layer 113, the conductive layer 123, and the insulating layer 127 (Figure 16E).

[0308] 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.

[0309] Subsequently, a protective layer 131 is formed on the common electrode 115 (Figure 16F). When applying a configuration having a colored layer on an insulating layer 135, as shown in Figure 1B, etc., the insulating layer 135 is formed on the protective layer 131, and colored layers 132R, 132G, and 132B are provided on the insulating layer 135. Then, the substrate 120 is bonded to the colored layers 132R, 132G, and 132B using the resin layer 122 to manufacture the display device (Figure 1B). Alternatively, when applying a configuration having a colored layer on the substrate 120 side, as shown in Figure 10, etc., colored layers 132R, 132G, and 132B are provided on the substrate 120 in advance, and the protective layer 131 and the colored layers formed on the substrate 120 are bonded together using the resin layer 122 to manufacture the display device.

[0310] Methods for forming the protective layer 131 and the insulating layer 135 include vacuum deposition, sputtering, CVD, and ALD.

[0311] As described above, in the manufacturing method of the display device of this embodiment, the island-shaped EL layer 113 is formed without using a fine metal mask, so the island-shaped EL layer 113 can be formed with a uniform thickness. This makes it possible to realize a high-definition display device or a display device with a high aperture ratio. Furthermore, even if the resolution or aperture ratio is high and the distance between subpixels is extremely short, it is possible to suppress the EL layer 113 from touching each other in adjacent subpixels. Therefore, it is possible to suppress the generation of leakage current between subpixels. This makes it possible to prevent unintended light emission caused by crosstalk and to realize a display device with extremely high contrast.

[0312] Furthermore, in the method for manufacturing the display device of this embodiment, three sub-pixels of different colors can be produced by forming only one type of EL layer. Therefore, the number of manufacturing steps is reduced, and the display device can be manufactured with a high yield.

[0313] Furthermore, by providing an insulating layer 127 having a tapered shape at its end between adjacent island-shaped EL layers 113, it is possible to suppress the occurrence of stepped breaks in the common electrode 115 during its formation, and to prevent the formation of locally thin areas in the common electrode 115. This makes it possible to suppress connection failures caused by the separated areas and increases in electrical resistance caused by locally thin areas in the common electrode 115. Therefore, a display device according to one aspect of the present invention can achieve both high resolution and high display quality.

[0314] This embodiment can be combined with other embodiments as appropriate.

[0315] (Embodiment 3) In this embodiment, a display device according to one aspect of the present invention will be described with reference to Figures 17 and 18.

[0316] [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.

[0317] In this embodiment, the upper surface shape of the sub-pixel shown in the figure corresponds to the upper surface shape of the light-emitting region.

[0318] Examples of the top surface shape of a sub-pixel include polygons such as triangles, quadrilaterals (including rectangles, rhombuses, and squares), pentagons, polygons with rounded corners, ellipses, or circles.

[0319] Furthermore, the circuit layout constituting the sub-pixel is not limited to the sub-pixel range shown in the figure; the circuit components may be arranged outside of it.

[0320] The pixel 110 shown in Figure 17A has an S-stripe array applied to it. The pixel 110 shown in Figure 17A is composed of three subpixels: subpixel 110a, subpixel 110b, and subpixel 110c.

[0321] The pixel 110 shown in Figure 17B 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 110b has a larger light-emitting area than sub-pixel 110a. In this way, the shape and size of each sub-pixel can be determined independently. For example, sub-pixels with more reliable light-emitting devices can be made smaller in size.

[0322] A Pentile array is applied to pixels 124a and 124b shown in Figure 17C. Figure 17C shows an example in which pixels 124a having sub-pixels 110a and 110b, and pixels 124b having sub-pixels 110b and 110c are arranged alternately.

[0323] A delta array is applied to pixels 124a and 124b shown in Figures 17D to 17F. 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).

[0324] Figure 17D shows an example where each subpixel has a roughly square top shape with rounded corners, Figure 17E shows an example where each subpixel has a circular top shape, and Figure 17F shows an example where each subpixel has a roughly hexagonal top shape with rounded corners.

[0325] In Figure 17F, each subpixel is located inside a densely packed hexagonal region. When focusing on a single subpixel, it is arranged so that it is surrounded by six other subpixels. Furthermore, subpixels that emit light of the same color are not adjacent to each other. For example, when focusing on subpixel 110a, three subpixels 110b and three subpixels 110c are arranged alternately around it.

[0326] Figure 17G shows an example where the subpixels of each color are arranged in a zigzag pattern. Specifically, in a top view, the upper edges of two subpixels aligned in the column direction (for example, subpixels 110a and 110b, or subpixels 110b and 110c) are offset.

[0327] In each pixel shown in Figures 17A to 17G, it is preferable, for example, that sub-pixel 110a be sub-pixel R that emits red light, sub-pixel 110b be sub-pixel G that emits green light, and sub-pixel 110c be sub-pixel B that emits blue light. However, the configuration of the sub-pixels is not limited to this, and the colors emitted by the sub-pixels and their order can be determined as appropriate. For example, sub-pixel 110b may be sub-pixel R that emits red light, and sub-pixel 110a may be sub-pixel G that emits green light.

[0328] In photolithography, the finer the pattern to be processed, the more significant the effect of light diffraction becomes. This impairs the fidelity of transferring the pattern to the photomask by 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 the pixel electrode may be a polygon with rounded corners, an ellipse, or a circle. In one embodiment of the present invention, the top surface shape of the EL layer, and furthermore, the top surface shape of the light-emitting device, may be influenced by the top surface shape of the pixel electrode, resulting in a polygon with rounded corners, an ellipse, or a circle.

[0329] Furthermore, in order to achieve the desired shape of the top surface of the pixel electrode, 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.

[0330] As shown in Figures 18A to 18I, a pixel can be configured to have four types of subpixels.

[0331] A stripe arrangement is applied to the pixels 110 shown in Figures 18A to 18C.

[0332] Figure 18A shows an example where each subpixel has a rectangular top surface shape, Figure 18B shows an example where each subpixel has a top surface shape formed by connecting two semicircles and a rectangle, and Figure 18C shows an example where each subpixel has an elliptical top surface shape.

[0333] A matrix array is applied to the pixels 110 shown in Figures 18D to 18F.

[0334] Figure 18D shows an example where each subpixel has a square top surface shape, Figure 18E shows an example where each subpixel has a roughly square top surface shape with rounded corners, and Figure 18F shows an example where each subpixel has a circular top surface shape.

[0335] Figures 18G and 18H show an example where one pixel 110 is composed of 2 rows and 3 columns.

[0336] Pixel 110, shown in Figure 18G, 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.

[0337] The pixel 110 shown in Figure 18H 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 18H, 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 device with high display quality can be provided.

[0338] Figure 18I shows an example where one pixel 110 is composed of 3 rows and 2 columns.

[0339] Pixel 110, shown in Figure 18I, has a sub-pixel 110a in the top row (1st row), a sub-pixel 110b in the middle row (2nd row), a sub-pixel 110c spanning from the 1st to the 2nd row, and one sub-pixel (sub-pixel 110d) in the bottom row (3rd row). In other words, pixel 110 has sub-pixels 110a and 110b in the left column (1st column), a sub-pixel 110c in the right column (2nd column), and a sub-pixel 110d spanning these two columns.

[0340] The pixel 110 shown in Figures 18A to 18I is composed of four subpixels: subpixel 110a, subpixel 110b, subpixel 110c, and subpixel 110d.

[0341] Sub-pixels 110a, 110b, 110c, and 110d can each be configured to have a light-emitting device that emits light of a different color. Examples of sub-pixels 110a, 110b, 110c, and 110d include sub-pixels of four colors: R, G, B, and white (W); sub-pixels of four colors: R, G, B, and Y; or sub-pixels of four colors: R, G, B, and infrared (IR).

[0342] In each pixel 110 shown in Figures 18A to 18I, it is preferable, for example, that sub-pixel 110a be sub-pixel R that emits red light, sub-pixel 110b be sub-pixel G that emits green light, sub-pixel 110c be sub-pixel B that emits blue light, and sub-pixel 110d be sub-pixel W that emits white light, sub-pixel Y that emits yellow light, or sub-pixel IR that emits near-infrared light. With such a configuration, in the pixels 110 shown in Figures 18G and 18H, the layout of R, G, and B becomes a stripe arrangement, which can improve the display quality. Also, in the pixels 110 shown in Figure 18I, the layout of R, G, and B becomes a so-called S-stripe arrangement, which can improve the display quality.

[0343] As described above, in one aspect of the present invention, various layouts can be applied to pixels that consist of subpixels having light-emitting devices.

[0344] This embodiment can be combined with other embodiments as appropriate.

[0345] (Embodiment 4) In this embodiment, a display device according to one aspect of the present invention will be described with reference to Figures 19 to 28.

[0346] The display device of this embodiment can be a high-definition display device. Therefore, the display device of this embodiment can be used, for example, as a display unit for information terminals (wearable devices) such as wristwatches and bracelets, and as a display unit for wearable devices that can be worn on the head, such as VR devices such as head-mounted displays (HMDs) and AR devices such as glasses.

[0347] Furthermore, the display device of this embodiment can be a high-resolution display device or a large-screen display device. Therefore, the display device 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 audio playback devices.

[0348] [Display Module] Figure 19A shows a perspective view of the display module 280. The display module 280 includes a display device 100A and an FPC 290. Note that the display device included in the display module 280 is not limited to display device 100A, but may be any of the display devices 100B to 100F described later.

[0349] 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.

[0350] Figure 19B 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 composed of multiple wires.

[0351] The pixel section 284 has a plurality of pixels 284a arranged periodically. A magnified view of one pixel 284a is shown on the right side of Figure 19B. Various configurations described in the previous embodiment can be applied to the pixel 284a. Figure 19B shows an example where the pixel has a configuration similar to that of the pixel 110 shown in Figure 1A.

[0352] The pixel circuit section 283 has a plurality of pixel circuits 283a arranged periodically.

[0353] A single pixel circuit 283a is a circuit that controls the driving of multiple elements in a single pixel 284a. A single pixel circuit 283a can be configured to have three circuits that control the light emission of a single light-emitting device. For example, a single pixel circuit 283a can be configured to have at least one selection transistor, one current control transistor (driving transistor), and a capacitor for each light-emitting device. In this case, a gate signal is input to the gate of the selection transistor, and a source signal is input to the source. This realizes an active-matrix type display device.

[0354] 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, a power supply circuit, etc.

[0355] 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.

[0356] The display module 280 can be configured such that one or both of the pixel circuit section 283 and the circuit section 282 are superimposed 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.

[0357] Because such a display module 280 is extremely high-resolution, it can be suitably used in VR devices such as HMDs or AR devices such as glasses. 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, and a highly immersive display can be achieved. 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 watches.

[0358] [Display device 100A] The display device 100A shown in Figure 20 includes a substrate 301, light-emitting devices 130R, 130G, 130B, a colored layer 132R, 132G, 132B, a capacitor 240, and a transistor 310.

[0359] As shown in Figure 19B, sub-pixel 11R has a light-emitting device 130R and a colored layer 132R, sub-pixel 11G has a light-emitting device 130G and a colored layer 132G, and sub-pixel 11B has a light-emitting device 130B and a colored layer 132B. In sub-pixel 11R, the light emitted by the light-emitting device 130R is extracted as red light (R) to the outside of the display device 100A via the colored layer 132R. Similarly, in sub-pixel 11G, the light emitted by the light-emitting device 130G is extracted as green light (G) to the outside of the display device 100A via the colored layer 132G. In sub-pixel 11B, the light emitted by the light-emitting device 130B is extracted as blue light (B) to the outside of the display device 100A via the colored layer 132B.

[0360] Substrate 301 corresponds to substrate 291 in Figures 19A and 19B. The laminated structure from substrate 301 to insulating layer 255c corresponds to layer 101 in Embodiment 1.

[0361] The transistor 310 is a transistor having a channel formation 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.

[0362] Furthermore, an element isolation layer 315 is provided between two adjacent transistors 310 so as to be embedded in the substrate 301.

[0363] Furthermore, an insulating layer 261 is provided covering the transistor 310, and a capacitance 240 is provided on the insulating layer 261.

[0364] 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.

[0365] 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 overlapping with the conductive layer 241 via the insulating layer 243.

[0366] Furthermore, it is preferable to provide a conductive layer surrounding the outside of the display unit 281 (or pixel unit 284) in at least one of the conductive layers of layer 101. This conductive layer can also be called a guard ring. By providing this conductive layer, it is possible to suppress the high voltage applied to elements such as transistors and light-emitting devices due to charging caused by ESD (electrostatic discharge) or plasma processes, which could damage these elements.

[0367] 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. Light-emitting devices 130R, 130G, and 130B are provided on the insulating layer 255c. Figure 20 shows an example in which light-emitting devices 130R, 130G, and 130B have the same structure as the laminated structure shown in Figure 1B.

[0368] Pixel electrodes 111R, 111G, and 111B are electrically connected to either the source or drain of transistor 310 by plugs 256 embedded in insulating layers 243, 255a, 255b, and 255c, a conductive layer 241 embedded in insulating layer 254, and a plug 271 embedded in insulating layer 261. The height of the surface of insulating layer 255c that contacts the pixel electrode and the height of the surface of plug 256 that contacts the pixel electrode are equal or approximately equal. Various conductive materials can be used for the plugs.

[0369] Furthermore, a protective layer 131 is provided on the light-emitting devices 130R, 130G, and 130B. An insulating layer 135 is provided on the protective layer 131, and on the insulating layer 135, a colored layer 132R is provided in a position overlapping with the light-emitting device 130R, a colored layer 132G is provided in a position overlapping with the light-emitting device 130G, and a colored layer 132B is provided in a position overlapping with the light-emitting device 130B. The substrate 120 is bonded to the colored layers 132R, 132G, and 132B 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 19A.

[0370] [Display device 100B] The display device 100B shown in Figure 21 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 device, parts that are the same as those described earlier may be omitted.

[0371] The display device 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.

[0372] Here, it is preferable to provide an insulating layer 345 on the lower surface (the surface on the substrate 301A side) of the substrate 301B. It is also preferable to provide an insulating layer 346 on top of the insulating layer 261 provided on the substrate 301A. The insulating layers 345 and 346 are insulating layers that function as protective layers and can suppress the diffusion of impurities into the substrates 301B and 301A. As the insulating layers 345 and 346, inorganic insulating films that can be used for the protective layer 131 can be used.

[0373] 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, suppressing the diffusion of impurities from the plug 343 to the substrate 301B. An inorganic insulating film, usable for the protective layer 131, can be used as the insulating layer 344.

[0374] 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 underside of the conductive layer 342 and the insulating layer 335 (the side facing the substrate 301A) is flattened. Here, the conductive layer 342 is electrically connected to the plug 343.

[0375] 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.

[0376] 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.

[0377] 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).

[0378] [Display device 100C] The display device 100C shown in Figure 22 has a configuration in which conductive layer 341 and conductive layer 342 are joined via bumps 347.

[0379] As shown in Figure 22, 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 including, 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 shown in Figure 21 may be omitted.

[0380] [Display device 100D] The display device 100D shown in Figure 23 differs from the display device 100A mainly in its transistor configuration.

[0381] 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.

[0382] 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.

[0383] Substrate 331 corresponds to substrate 291 in Figures 19A and 19B. The laminated structure from substrate 331 to insulating layer 255c corresponds to layer 101 in Embodiment 1. An insulating substrate or a semiconductor substrate can be used as substrate 331.

[0384] 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.

[0385] 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.

[0386] 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.

[0387] 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.

[0388] 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.

[0389] 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.

[0390] 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.

[0391] 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.

[0392] [Display device 100E] The display device 100E shown in Figure 24 has a configuration in which transistors 320A and 320B, each having an oxide semiconductor in the semiconductor layer where the channel is formed, are stacked.

[0393] For details regarding transistors 320A and 320B, and their peripheral configurations, please refer to the display device 100D described above.

[0394] 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.

[0395] [Display device 100F] The display device 100F shown in Figure 25 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.

[0396] 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.

[0397] 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.

[0398] 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 device compared to cases where the drive circuits are located around the display area.

[0399] [Display device 100G] Figure 26 shows a perspective view of the display device 100G, and Figure 27A shows a cross-sectional view of the display device 100G.

[0400] The display device 100G has a configuration in which substrate 152 and substrate 151 are bonded together. In Figure 26, substrate 152 is clearly indicated by a dashed line.

[0401] The display device 100G includes a display unit 162, a connection unit 140, a circuit 164, wiring 165, etc. Figure 26 shows an example in which the IC 173 and FPC 172 are mounted on the display device 100G. Therefore, the configuration shown in Figure 26 can also be described as a display module having the display device 100G, an IC (integrated circuit), and an FPC.

[0402] The connection portion 140 is provided on the outside of the display unit 162. The connection portion 140 can be provided along one or more sides of the display unit 162. There may be one or more connection portions 140. Figure 26 shows an example in which the connection portion 140 is provided so as to surround all four sides of the display unit 162. 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.

[0403] For example, a scan line drive circuit can be used as circuit 164.

[0404] The 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 the wiring 165 from an external source via the FPC 172, or from the IC 173.

[0405] Figure 26 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 device 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.

[0406] Figure 27A shows an example of a cross-section of the display device 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.

[0407] The display device 100G shown in Figure 27A has a transistor 201, a transistor 205, a light-emitting device 130R, a light-emitting device 130G, a light-emitting device 130B, a colored layer 132R that transmits red light, a colored layer 132G that transmits green light, a colored layer 132B that transmits blue light, etc., between substrates 151 and 152.

[0408] Light-emitting devices 130R, 130G, and 130B each have a structure similar to the stacked structure shown in Figure 1B, except that the pixel electrode configuration differs. Details of the light-emitting devices can be found in Embodiment 1.

[0409] The light-emitting device 130R has a conductive layer 112R, a conductive layer 126R on the conductive layer 112R, and a conductive layer 129R on the conductive layer 126R. All of the conductive layers 112R, 126R, and 129R can be called pixel electrodes, or only a part of them can be called pixel electrodes.

[0410] The light-emitting device 130G includes a conductive layer 112G, a conductive layer 126G on the conductive layer 112G, and a conductive layer 129G on the conductive layer 126G.

[0411] The light-emitting device 130B includes a conductive layer 112B, a conductive layer 126B on the conductive layer 112B, and a conductive layer 129B on the conductive layer 126B.

[0412] The conductive layer 112R is connected to the conductive layer 222b of the transistor 205 through an opening provided in the insulating layer 214. It is preferable that the edges of the conductive layer 112R, the conductive layer 126R, and the conductive layer 129R are aligned or approximately aligned. This makes it possible to make the height of the sidewall insulating layer 114 equal to or greater than the sum of the thicknesses of the three conductive layers, thus making it easy to thin a portion of the EL layer or divide the EL layer with the sidewall insulating layer 114. For example, conductive layers that function as reflective electrodes can be used for conductive layers 112R and 126R, and a conductive layer that functions as a transparent electrode can be used for conductive layer 129R.

[0413] Since conductive layers 112G, 126G, 129G, and 112B, 126B, and 129B are the same as conductive layers 112R, 126R, and 129R, a detailed explanation is omitted.

[0414] The conductive layer 112R, conductive layer 112G, and conductive layer 112B have recesses formed to cover the openings provided in the insulating layer 214. Layer 128 is embedded in these recesses.

[0415] Layer 128 has the function of flattening the recesses of conductive layers 112R, 112G, and 112B. Conductive layers 126R, 126G, and 126B are provided on conductive layers 112R, 112G, 112B, and 128, respectively, and are electrically connected to conductive layers 112R, 112G, and 112B. Therefore, regions overlapping with the recesses of conductive layers 112R, 112G, and 112B can also be used as light-emitting regions, thereby increasing the aperture ratio of the pixels.

[0416] 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, and especially preferable that it be formed using an organic insulating material.

[0417] As layer 128, an insulating layer having an organic material can be suitably used. Examples of organic materials that can be used for layer 128 include organic materials that can be used for the protective layer 131 or the insulating layer 135.

[0418] The upper and side surfaces of adjacent EL layers 113, the side surfaces of the side wall insulating layer 114, the upper surface of the material layer 113s, and the upper and side surfaces of the conductive layer 123 are covered by insulating layer 125 and insulating layer 127. A common electrode 115 is provided on the EL layer 113, insulating layer 125, and insulating layer 127 so as to cover them. This prevents the common electrode 115 from being broken up due to the step difference between adjacent pixel electrodes, thereby improving the manufacturing yield of the light-emitting device. The common electrode 115 is a continuous film provided in common to multiple light-emitting devices.

[0419] Furthermore, a protective layer 131 is provided on the light-emitting devices 130R, 130G, and 130B. The protective layer 131 and the substrate 152 are bonded together via an adhesive layer 142. The substrate 152 is provided with a light-shielding layer 117, a colored layer 132R, a colored layer 132G, and a colored layer 132B. A solid encapsulation structure or a hollow encapsulation structure can be applied to seal the light-emitting devices. In Figure 27A, the space between the substrate 152 and the substrate 151 is filled with the adhesive layer 142, and a solid encapsulation structure is applied. Alternatively, the space may be filled with an inert gas (such as nitrogen or argon), and a hollow encapsulation structure may be applied. In this case, the adhesive layer 142 may be provided so as not to overlap with the light-emitting devices. The space may also be filled with a resin different from the adhesive layer 142, which is provided in a frame shape.

[0420] The protective layer 131 is provided at least on the display unit 162, and preferably so as to cover the entire display unit 162. It is preferable that the protective layer 131 covers not only the display unit 162, but also the connection unit 140 and the circuit 164. Furthermore, it is preferable that the protective layer 131 extends to the edges of the display device 100G. On the other hand, in the connection unit 204, there is a portion where the protective layer 131 is not provided in order to electrically connect the FPC 172 and the conductive layer 166.

[0421] 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 112R, 112G, and 112B, a conductive film obtained by processing the same conductive film as conductive layers 126R, 126G, and 126B, and a conductive film obtained by processing the same conductive film as conductive layers 129R, 129G, and 129B. On the upper surface of the connection portion 204, the conductive layer 166 is exposed. This allows the connection portion 204 and FPC 172 to be electrically connected via the connection layer 242.

[0422] For example, after the protective layer 131 is deposited on the entire surface of the display device 100G, the conductive layer 166 can be exposed by removing the area of ​​the protective layer 131 that overlaps with the conductive layer 166 using a mask.

[0423] Alternatively, a laminated structure of at least one organic layer and a conductive layer may be provided on the conductive layer 166, and a protective layer 131 may be provided on the laminated structure. Then, a starting point for peeling (a part that triggers peeling) may be formed on the laminated structure using a laser or a sharp blade (e.g., a needle or cutter), and the laminated structure and the protective layer 131 on it may be selectively removed, exposing the conductive layer 166. For example, the protective layer 131 can be selectively removed by pressing an adhesive roller against the substrate 151 and moving the roller relatively while rotating it. Alternatively, an adhesive tape may be attached to the substrate 151 and peeled off. Due to the low adhesion between the organic layer and the conductive layer, or between the organic layers themselves, separation occurs at the interface between the organic layer and the conductive layer, or within the organic layer. This allows for the selective removal of the region of the protective layer 131 that overlaps with the conductive layer 166. If any organic layers remain on the conductive layer 166, they can be removed with an organic solvent or the like.

[0424] As the organic layer, for example, at least one organic layer used in the EL layer 113 (a layer that functions as a light-emitting layer, a carrier block layer, a carrier transport layer, or a carrier implantation layer) can be used. The organic layer may be formed simultaneously with the deposition of the EL layer 113, or it may be provided separately. The conductive layer can be formed using the same process and materials as the common electrode 115. For example, it is preferable to form an ITO film as both the common electrode 115 and the conductive layer. When a laminated structure is used for the common electrode 115, at least one layer from among the layers constituting the common electrode 115 should be provided as the conductive layer.

[0425] Furthermore, the upper surface of the conductive layer 166 may be covered with a mask to prevent the protective layer 131 from being formed on the conductive layer 166. As the mask, for example, a metal mask (area metal mask) may be used, or an adhesive or suction tape or film may be used. By forming the protective layer 131 with the mask in place and then removing the mask, the conductive layer 166 can be kept exposed even after the protective layer 131 has been formed.

[0426] Using this method, a region of the connection portion 204 where the protective layer 131 is not provided can be formed, and in that region, the conductive layer 166 and the FPC 172 can be electrically connected via the connection layer 242.

[0427] 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 112R, 112G, and 112B, a conductive film obtained by processing the same conductive film as conductive layers 126R, 126G, and 126B, and a conductive film obtained by processing the same conductive film as conductive layers 129R, 129G, and 129B. The sides of the conductive layer 123 are covered by a sidewall insulating layer 114. The sidewall insulating layer 114 functions as a sidewall for the conductive layer 123. Furthermore, the top and sides of the sidewall insulating layer 114, and a part of the top and sides of the conductive layer 123 are covered by insulating layers 125 and 127. A common electrode 115 is provided on the conductive layer 123, the insulating layer 125, and the insulating layer 127, covering them. The common electrode 115 is in contact with a portion of the upper surface of the conductive layer 123 (the portion not covered by the insulating layers 125 and 127). In other words, at the connection portion 140, the conductive layer 123 and the common electrode 115 are electrically connected.

[0428] The display device 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.

[0429] The laminated structure from the substrate 151 to the insulating layer 214 corresponds to layer 101 in Embodiment 1.

[0430] Both transistors 201 and 205 are formed on the substrate 151. These transistors can be manufactured using the same materials and the same process.

[0431] 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.

[0432] It is preferable to use a material that does not easily allow impurities such as water and hydrogen to diffuse into at least one layer of the insulating layer covering the transistor. This allows the insulating layer to function as a barrier layer. With such a configuration, the diffusion of impurities from the outside into the transistor can be effectively suppressed, thereby improving the reliability of the display device.

[0433] It is preferable to use inorganic insulating films for insulating layers 211, 213, and 215. Examples of inorganic insulating films that can be used include silicon nitride, silicon oxide nitride, silicon oxide, silicon nitride, aluminum oxide, and aluminum nitride. Alternatively, hafnium oxide, yttrium oxide, zirconium oxide, gallium oxide, tantalum oxide, magnesium oxide, lanthanum oxide, cerium oxide, neodymium oxide, and the like may also be used. Furthermore, two or more of the above insulating films may be laminated together.

[0434] An organic insulating layer is preferred for the insulating layer 214, which 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 112R, 126R, or 129R. Alternatively, depressions may be provided in the insulating layer 214 when processing conductive layers 112R, 126R, or 129R.

[0435] Transistors 201 and 205 have a conductive layer 221 that functions as a gate electrode, an insulating layer 211 that functions as a gate insulating layer, conductive layers 222a and 222b that function as source and drain electrodes, 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 electrode. 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.

[0436] The transistor structure of the display device of this embodiment is not particularly limited. For example, planar transistors, staggered transistors, inverse staggered transistors, etc., can be used. Furthermore, either a top-gate or bottom-gate transistor structure may be used. Alternatively, gate electrodes may be provided above and below the semiconductor layer in which the channel is formed.

[0437] Transistors 201 and 205 are configured in which a semiconductor layer on which a channel is formed is sandwiched between two gate electrodes. The transistors may be driven by connecting the two gate electrodes 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 gate electrodes and a potential to drive the other.

[0438] The crystallinity of the semiconductor material used in the transistor is not particularly limited; amorphous semiconductors, single-crystal semiconductors, or semiconductors with crystalline properties other than single crystals (microcrystalline semiconductors, polycrystalline semiconductors, or semiconductors with crystalline regions in part) may be used. Using a single-crystal semiconductor or a semiconductor with crystalline properties is preferable because it can suppress the degradation of transistor characteristics.

[0439] The semiconductor layer of the transistor preferably has a metal oxide (also called an oxide semiconductor). In other words, the display device of this embodiment preferably uses a transistor (hereinafter referred to as an OS transistor) that uses a metal oxide in the channel formation region.

[0440] Examples of crystalline oxide semiconductors include CAAC (C-Axis-Aligned Crystalline)-OS and nc (nanocrystalline)-OS.

[0441] 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, it is preferable to use a transistor having low-temperature polysilicon (LTPS (Low Temperature Poly Silicon)) in the semiconductor layer (hereinafter also referred to as an LTPS transistor). LTPS transistors have high field-effect mobility and good frequency characteristics.

[0442] By using Si transistors such as LTPS transistors, circuits that need to be driven at high frequencies (e.g., source driver circuits) can be fabricated on the same board as the display unit. This simplifies the external circuits implemented in the display device, reducing component and mounting costs.

[0443] OS transistors have extremely high field-effect mobility compared to transistors using amorphous silicon. Furthermore, OS transistors exhibit remarkably low source-drain leakage current (hereinafter also referred to as off-current) in the off state, allowing them to retain charge stored in a capacitor connected in series with the transistor for extended periods. Additionally, the application of OS transistors can reduce the power consumption of display devices.

[0444] 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.

[0445] 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.

[0446] 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.

[0447] 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."

[0448] 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, it is preferable that M is one or more selected from aluminum, gallium, yttrium, and tin.

[0449] 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).

[0450] 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. The atomic ratios of the metal elements in such an In-M-Zn oxide include: In:M:Zn=1:1:1 or near thereto, In:M:Zn=1:1:1.2 or near thereto, In:M:Zn=1:3:2 or near thereto, In:M:Zn=1:3:4 or near thereto, In:M:Zn=2:1:3 or near thereto, In:M:Zn=3:1:2 or near thereto, In:M:Zn=4:2: Examples include compositions of 3 or nearby, In:M:Zn=4:2:4.1 or nearby, In:M:Zn=5:1:3 or nearby, In:M:Zn=5:1:6 or nearby, In:M:Zn=5:1:7 or nearby, In:M:Zn=5:1:8 or nearby, In:M:Zn=6:1:6 or nearby, In:M:Zn=5:2:5 or nearby, etc. Note that nearby compositions include a range of ±30% of the desired atomic ratio.

[0451] For example, when describing an atomic ratio of In:Ga:Zn = 4:2:3 or a composition close to that, it includes cases where, when In is set to 4, Ga is between 1 and 3, and Zn is between 2 and 4. Also, when describing an atomic ratio of In:Ga:Zn = 5:1:6 or a composition close to that, it includes cases where, when In is set to 5, Ga is greater than 0.1 and 2 or less, and Zn is between 5 and 7. Furthermore, when describing an atomic ratio of In:Ga:Zn = 1:1:1 or a composition close to that, it includes cases where, when In is set to 1, Ga is greater than 0.1 and 2 or less, and Zn is greater than 0.1 and 2 or less.

[0452] 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.

[0453] 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.

[0454] For example, by using both an LTPS transistor and an OS transistor in the display unit 162, a display device with low power consumption and high driving capability can be realized. Furthermore, a configuration combining an LTPS transistor and an OS transistor is sometimes referred to as LTPO. In a more preferable example, it is preferable to apply an OS transistor to transistors that function as switches for controlling conduction and non-conduction between wires, and an LTPS transistor to transistors that control current.

[0455] 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 this drive transistor. This makes it possible to increase the current flowing to the light-emitting device in the pixel circuit.

[0456] 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.

[0457] Thus, a display device according to one aspect of the present invention can combine a high aperture ratio, high resolution, high display quality, and low power consumption.

[0458] Furthermore, one embodiment of the present invention is a display device 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 device, the observer can observe one or more of the following: image sharpness, image clarity, high saturation, and high contrast ratio. Moreover, by having an extremely low leakage current that can flow through the transistor and lateral leakage current between light-emitting devices, it is possible to minimize light leakage (so-called black floating) that may occur when displaying black.

[0459] Figures 27B and 27C show other examples of transistor configurations.

[0460] Transistors 209 and 210 each have a conductive layer 221 that functions as a gate electrode, 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 electrode, 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.

[0461] In the transistor 209 shown in Figure 27B, 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 electrode and the other as the drain electrode.

[0462] On the other hand, in the transistor 210 shown in Figure 27C, 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 27C can be fabricated by processing the insulating layer 225 using the conductive layer 223 as a mask. In Figure 27C, 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.

[0463] 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, in connection parts 140, circuits 164, etc. In addition, various optical components can be arranged on the outside of the substrate 152.

[0464] Substrates 151 and 152 can be made from materials that can be used for substrate 120, as shown in Figure 1B, etc.

[0465] As the adhesive layer 142, a material that can be used for the resin layer 122 shown in Figure 1B, etc., can be applied.

[0466] As the connecting layer 242, an anisotropic conductive film (ACF), an anisotropic conductive paste (ACP), etc., can be used.

[0467] [Display device 100H] The display device 100H shown in Figure 28A differs from the display device 100G mainly in that it is a bottom-emission type display device.

[0468] The light emitted by the light-emitting device is emitted towards the substrate 151. It is preferable to use a material with high transmittance 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.

[0469] 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 28A 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. In addition, a colored layer 132R, a colored layer 132G, and a colored layer 132B (not shown) are provided on the insulating layer 215.

[0470] The light-emitting device 130R has a conductive layer 112R and a conductive layer 126R on the conductive layer 112R.

[0471] The light-emitting device 130G has a conductive layer 112G and a conductive layer 126G on the conductive layer 112G.

[0472] The light-emitting device 130B includes a conductive layer 112B and a conductive layer 126B on the conductive layer 112B (neither of which are shown in the figure).

[0473] It is preferable to use materials with high transmittance to visible light for conductive layers 112R, 112G, 126R, and 126G. It is preferable to use a material that reflects visible light for the common electrode 115.

[0474] Furthermore, while Figures 27A and 28A show examples where the upper surface of layer 128 has a flat portion, the shape of layer 128 is not particularly limited. Figures 28B to 28D show modified examples of layer 128.

[0475] As shown in Figures 28B and 28D, 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.

[0476] Furthermore, as shown in Figure 28C, the upper surface of layer 128 can be configured to have a shape that bulges in the center and its vicinity when viewed in cross-section, that is, a shape with a convex curved surface.

[0477] 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.

[0478] Furthermore, the height of the top surface of layer 128 and the height of the top surface of conductive layer 112R may be the same, approximately the same, or 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 conductive layer 112R. The same applies to conductive layer 112G and conductive layer 112B.

[0479] Furthermore, Figure 28B can be seen as an example in which layer 128 is housed inside a recess formed in the conductive layer 112R. On the other hand, as shown in Figure 28D, layer 128 may exist outside the recess formed in the conductive layer 112R, that is, the width of the upper surface of layer 128 may be wider than that of the recess. The same applies to conductive layer 112G and conductive layer 112B.

[0480] This embodiment can be combined with other embodiments as appropriate.

[0481] (Embodiment 5) This embodiment describes a light-emitting device that can be used in a display device according to one aspect of the present invention.

[0482] As shown in Figure 29A, the light-emitting device has an EL layer 763 between a pair of electrodes (lower electrode 761 and upper electrode 762). The EL layer 763 can be composed of multiple layers, such as layer 780, light-emitting layer 771, and layer 790.

[0483] The light-emitting layer 771 has at least a light-emitting substance (also called a light-emitting material).

[0484] When the lower electrode 761 is the anode and the upper electrode 762 is the cathode, layer 780 has one or more of the following: a layer containing a material with high hole injection properties (hole injection layer), a layer containing a material with high hole transport properties (hole transport layer), and a layer containing a material with high electron blocking properties (electron blocking layer). Similarly, layer 790 has one or more of the following: a layer containing a material with high electron injection properties (electron injection layer), a layer containing a material with high electron transport properties (electron transport layer), and a layer containing a material with high hole blocking properties (hole blocking layer). When the lower electrode 761 is the cathode and the upper electrode 762 is the anode, layers 780 and 790 have the opposite configurations to those described above.

[0485] A configuration having a layer 780, an emissive layer 771, and a layer 790 provided between a pair of electrodes can function as a single emissive unit, and in this specification, the configuration shown in Figure 29A is referred to as a single structure.

[0486] Furthermore, Figure 29B shows a modified example of the EL layer 763 of the light-emitting device shown in Figure 29A. Specifically, the light-emitting device shown in Figure 29B has a layer 781 on the lower electrode 761, a layer 782 on the layer 781, a light-emitting layer 771 on the layer 782, a layer 791 on the light-emitting layer 771, a layer 792 on the layer 791, and an upper electrode 762 on the layer 792.

[0487] When the lower electrode 761 is the anode and the upper electrode 762 is the cathode, for example, layer 781 can be a hole injection layer, layer 782 a hole transport layer, layer 791 an electron transport layer, and layer 792 an electron injection layer. Also, when the lower electrode 761 is the cathode and the upper electrode 762 is the anode, layer 781 can be an electron injection layer, layer 782 an electron transport layer, layer 791 a hole transport layer, and layer 792 a hole injection layer. By using such a layer structure, carriers can be efficiently injected into the light-emitting layer 771, and the efficiency of carrier recombination within the light-emitting layer 771 can be increased.

[0488] As shown in Figures 29C and 29D, a configuration in which multiple light-emitting layers (light-emitting layer 771, light-emitting layer 772, and light-emitting layer 773) are provided between layer 780 and layer 790 is also a variation of the single structure. Although Figures 29C and 29D show an example with three light-emitting layers, the light-emitting layers in a single-structure light-emitting device may be two layers or four or more layers. Furthermore, a single-structure light-emitting device may have a buffer layer between the two light-emitting layers.

[0489] Furthermore, as shown in Figures 29E and 29F, a configuration in which multiple light-emitting units (light-emitting units 763a and 763b) are connected in series via a charge generation layer 785 (also called an intermediate layer) is referred to as a tandem structure in this specification. The tandem structure may also be called a stacked structure. By using a tandem structure, a light-emitting device capable of high-brightness emission can be created. In addition, compared to a single structure, the tandem structure can reduce the current required to obtain the same brightness, thereby improving reliability.

[0490] Figures 29D and 29F show examples in which the display device has a layer 764 that overlaps with the light-emitting device. Figure 29D shows an example in which layer 764 overlaps with the light-emitting device shown in Figure 29C, and Figure 29F shows an example in which layer 764 overlaps with the light-emitting device shown in Figure 29E. In Figures 29D and 29F, a conductive film that transmits visible light is used for the upper electrode 762 in order to extract light to the upper electrode 762 side.

[0491] Layer 764 can be either a color conversion layer or a color filter (coloring layer), or both.

[0492] In Figures 29C and 29D, the light-emitting layers 771, 772, and 773 can each be made of light-emitting materials that emit light of different colors. When the light emitted by the light-emitting layers 771, 772, and 773 are complementary in color, white light emission is obtained from the entire light-emitting layer. For example, a single-structure light-emitting device preferably has a light-emitting layer having a light-emitting material that emits blue light, and a light-emitting layer having a light-emitting material that emits visible light with a longer wavelength than blue.

[0493] It is preferable to provide a color filter as layer 764, as shown in Figure 29D. By passing white light through the color filter, light of the desired color can be obtained.

[0494] For example, if a single-structure light-emitting device has three light-emitting layers, it is preferable that it has a light-emitting layer having a light-emitting material that emits red (R) light, a light-emitting layer having a light-emitting material that emits green (G) light, and a light-emitting layer having a light-emitting material that emits blue (B) light. The stacking order of the light-emitting layers can be R, G, B from the anode side, or R, B, G from the anode side, etc. In this case, a buffer layer may be provided between R and G or B.

[0495] Furthermore, for example, when a single-structure light-emitting device has two light-emitting layers, a configuration is preferred in which one light-emitting layer has a light-emitting material that emits blue (B) light, and the other light-emitting layer has a light-emitting material that emits yellow (Y) light. This configuration may be referred to as a BY single structure.

[0496] A light-emitting device that emits white light preferably contains two or more types of light-emitting materials. To obtain white light emission, the light-emitting materials should be selected such that the light emitted by each of the two or more materials is complementary in color. For example, by making the light-emitting color of the first light-emitting layer and the light-emitting color of the second light-emitting layer complementary in color, a light-emitting 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.

[0497] Furthermore, in Figures 29C and 29D, as shown in Figure 29B, layer 780 and layer 790 may each be independently constructed as a laminated structure consisting of two or more layers.

[0498] Furthermore, in Figures 29E and 29F, the light-emitting layer 771 and the light-emitting layer 772 can be made of light-emitting materials that emit light of different colors. When the light emitted by the light-emitting layer 771 and the light emitted by the light-emitting layer 772 are complementary colors, white light emission is obtained overall. It is preferable to provide a color filter as layer 764 as shown in Figure 29F. By passing white light through the color filter, light of the desired color can be obtained.

[0499] In Figures 29E and 29F, examples are shown in which the light-emitting unit 763a has one light-emitting layer 771 and the light-emitting unit 763b has one light-emitting layer 772, but the design is not limited to this. The light-emitting unit 763a and the light-emitting unit 763b may each have two or more light-emitting layers.

[0500] Furthermore, while Figures 29E and 29F illustrate a light-emitting device having two light-emitting units, the device is not limited to this. A light-emitting device may have three or more light-emitting units. A configuration with two light-emitting units may be referred to as a two-stage tandem structure, and a configuration with three light-emitting units may be referred to as a three-stage tandem structure.

[0501] Furthermore, in Figures 29E and 29F, the light-emitting unit 763a has layer 780a, light-emitting layer 771, and layer 790a, and the light-emitting unit 763b has layer 780b, light-emitting layer 772, and layer 790b.

[0502] When the lower electrode 761 is the anode and the upper electrode 762 is the cathode, layers 780a and 780b each have one or more of the following: a hole injection layer, a hole transport layer, and an electron blocking layer. Similarly, layers 790a and 790b each have one or more of the following: an electron injection layer, an electron transport layer, and a hole blocking layer. When the lower electrode 761 is the cathode and the upper electrode 762 is the anode, layers 780a and 790a have the opposite configurations to those described above, and layers 780b and 790b also have the opposite configurations to those described above.

[0503] When the lower electrode 761 is the anode and the upper electrode 762 is the cathode, for example, layer 780a has a hole injection layer and a hole transport layer on the hole injection layer, and may further have an electron blocking layer on the hole transport layer. Also, layer 790a has an electron transport layer and may further have a hole blocking layer between the light-emitting layer 771 and the electron transport layer. Also, layer 780b has a hole transport layer and may further have an electron blocking layer on the hole transport layer. Also, layer 790b has an electron transport layer and an electron injection layer on the electron transport layer, and may further have a hole blocking layer between the light-emitting layer 772 and the electron transport layer. When the lower electrode 761 is the cathode and the upper electrode 762 is the anode, for example, layer 780a has an electron injection layer and an electron transport layer on the electron injection layer, and may further have a hole blocking layer on the electron transport layer. Furthermore, layer 790a may have a hole transport layer and an electron blocking layer between the light-emitting layer 771 and the hole transport layer. Also, layer 780b may have an electron transport layer and an electron blocking layer on the electron transport layer. Furthermore, layer 790b may have a hole transport layer and a hole injection layer on the hole transport layer, and an electron blocking layer between the light-emitting layer 772 and the hole transport layer.

[0504] Furthermore, when fabricating a tandem light-emitting device, the two light-emitting units are stacked with a charge generation layer 785 in between. The charge generation layer 785 has at least a charge generation region. The charge generation layer 785 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.

[0505] Furthermore, an example of a tandem-structured light-emitting device is the configuration shown in Figures 30A to 30C.

[0506] Figure 30A shows a configuration having three light-emitting units. In Figure 30A, multiple light-emitting units (light-emitting units 763a, 763b, and 763c) are connected in series via a charge generation layer 785. Light-emitting unit 763a has layer 780a, light-emitting layer 771, and layer 790a; light-emitting unit 763b has layer 780b, light-emitting layer 772, and layer 790b; and light-emitting unit 763c has layer 780c, light-emitting layer 773, and layer 790c. Layer 780c can use a configuration applicable to layers 780a and 780b, and layer 790c can use a configuration applicable to layers 790a and 790b.

[0507] In Figure 30A, some or all of the light-emitting layers 771, 772, and 773 can be made of light-emitting materials that emit light of different colors. Examples of combinations of light-emitting colors for the light-emitting layers 771, 772, and 773 include a configuration where two are blue (B) and the remaining one is yellow (Y), and a configuration where one is red (R), another is green (G), and the remaining one is blue (B).

[0508] Figure 30B shows a tandem-type light-emitting device in which light-emitting units having multiple light-emitting layers are stacked. In Figure 30B, two light-emitting units (light-emitting unit 763a and light-emitting unit 763b) are connected in series via a charge generation layer 785. Light-emitting unit 763a has layer 780a, light-emitting layers 771a, 771b, and 771c, and layer 790a, while light-emitting unit 763b has layer 780b, light-emitting layers 772a, 772b, and 772c, and layer 790b.

[0509] In Figure 30B, for light-emitting layers 771a, 771b, and 771c, complementary colored light-emitting materials are selected to configure the light-emitting unit 763a to emit white light (W). Similarly, for light-emitting layers 772a, 772b, and 772c, complementary colored light-emitting materials are selected to configure the light-emitting unit 763b to emit white light (W). In other words, the configuration shown in Figure 30B can be described as a two-stage tandem structure of W\W. There are no particular limitations on the stacking order of the complementary colored light-emitting materials. The implementer can select the optimal stacking order as appropriate. Although not shown, a three-stage tandem structure of W\W\W or a tandem structure of four or more stages may also be used. Note that "a\b" means that a light-emitting unit having a light-emitting material that emits light a is provided on a light-emitting unit having a light-emitting material that emits light b via a charge generation layer, and a and b represent colors.

[0510] Furthermore, when using a tandem light-emitting device, there are two-stage tandem structures of B\Y or Y\B having a light-emitting unit that emits yellow (Y) light and a light-emitting unit that emits blue (B) light, two-stage tandem structures of R·G\B or B\R·G having a light-emitting unit that emits red (R) and green (G) light and a light-emitting unit that emits blue (B) light, and a light-emitting unit that emits blue (B) light, and a light-emitting unit that emits yellow (Y) light and a light-emitting unit that emits blue (B) light. Examples include a three-stage tandem structure B\Y\B having a light-emitting unit and a light-emitting unit in this order, a three-stage tandem structure B\YG\B having a light-emitting unit that emits blue (B) light, a light-emitting unit that emits yellow-green (YG) light, and a light-emitting unit that emits blue (B) light in this order, and a three-stage tandem structure B\G\B having a light-emitting unit that emits blue (B) light, a light-emitting unit that emits green (G) light, and a light-emitting unit that emits blue (B) light in this order. Note that "a·b" means that one light-emitting unit has a light-emitting material that emits light a and a light-emitting material that emits light b.

[0511] Furthermore, as shown in Figure 30C, a combination of a light-emitting unit having one light-emitting layer and a light-emitting unit having multiple light-emitting layers may be used.

[0512] Specifically, in the configuration shown in Figure 30C, multiple light-emitting units (light-emitting units 763a, 763b, and 763c) are connected in series via a charge generation layer 785. Furthermore, light-emitting unit 763a has a layer 780a, a light-emitting layer 771, and a layer 790a; light-emitting unit 763b has a layer 780b, a light-emitting layer 772a, a light-emitting layer 772b, a light-emitting layer 772c, and a layer 790b; and light-emitting unit 763c has a layer 780c, a light-emitting layer 773, and a layer 790c.

[0513] For example, in the configuration shown in Figure 30C, a three-stage tandem structure of B\R·G·YG\B can be applied, where light-emitting unit 763a is a light-emitting unit that emits blue (B) light, light-emitting unit 763b is a light-emitting unit that emits red (R), green (G), and yellow-green (YG) light, and light-emitting unit 763c is a light-emitting unit that emits blue (B) light.

[0514] For example, the number of layers and color order of the light-emitting unit can be, from the anode side, a two-layer structure of B and Y, a two-layer structure of B and light-emitting unit X, a three-layer structure of B, Y, B, or a three-layer structure of B, X, B. The number of layers and color order of the light-emitting layers in light-emitting unit X can be, from the anode side, a two-layer structure of R and Y, a two-layer structure of R and G, a two-layer structure of G and R, a three-layer structure of G, R, G, or a three-layer structure of R, G, R. In addition, other layers may be provided between the two light-emitting layers.

[0515] Next, we will describe materials that can be used in light-emitting devices.

[0516] Of the lower electrode 761 and upper electrode 762, the electrode that extracts light preferably uses a conductive film that transmits visible light. Furthermore, it is preferable to use a conductive film that reflects visible light on the electrode that does not extract light. In addition, if the display device has a light-emitting device that emits infrared light, it is preferable to use a conductive film that transmits both visible light and infrared light on the electrode that extracts light, and a conductive film that reflects both visible light and infrared light on the electrode that does not extract light.

[0517] Furthermore, a conductive film that transmits visible light may also be used for the electrode on the side that does not extract light. In this case, it is preferable to place the electrode between the reflective layer and the EL layer 763. In other words, the light emitted from the EL layer 763 may be reflected by the reflective layer and extracted from the display device.

[0518] As the material for forming the pair of electrodes of the light-emitting device, metals, alloys, electrically conductive compounds, and mixtures thereof can be used as appropriate. Specifically, such materials include metals such as aluminum, titanium, chromium, manganese, iron, cobalt, nickel, copper, gallium, zinc, indium, tin, molybdenum, tantalum, tungsten, palladium, gold, platinum, silver, yttrium, and neodymium, as well as alloys containing these in appropriate combinations. Other examples of such materials include indium tin oxide (In-Sn oxide, also called ITO), In-Si-Sn oxide (also called ITSO), indium zinc oxide (In-Zn oxide), and In-W-Zn oxide. Furthermore, other examples of such materials include aluminum-containing alloys such as aluminum, nickel, and lanthanum alloys (Al-Ni-La), and silver, palladium, and copper alloys (Ag-Pd-Cu, also written as APC). Other materials include elements belonging to Group 1 or Group 2 of the periodic table not exemplified above (e.g., lithium, cesium, calcium, strontium), rare earth metals such as europium and ytterbium, alloys containing these in appropriate combinations, graphene, and the like.

[0519] 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.

[0520] Furthermore, the semi-transparent / semi-reflective electrode can have a laminated structure consisting of a conductive layer that can be used as a reflective electrode and a conductive layer that can be used as an electrode that transmits visible light (a transparent electrode).

[0521] The light transmittance of the transparent electrode shall be 40% or more. For example, it is preferable to use an electrode with a transmittance of 40% or more for visible light (light with a wavelength of 400 nm or more and less than 750 nm) for the transparent electrode of a light-emitting device. The visible light reflectance of the semi-transparent / semi-reflective electrode shall be 10% or more and 95% or less, preferably 30% or more and 80% or less. The visible light reflectance of the reflective electrode shall be 40% or more and 100% or less, preferably 70% or more and 100% or less. The resistivity of these electrodes shall be 1 × 10⁻⁶ -2 A value of Ωcm or less is preferable.

[0522] A light-emitting device has at least a light-emitting layer. Furthermore, a light-emitting device may have layers other than the light-emitting layer, including materials with high hole injection properties, materials with high hole transport properties, hole-blocking materials, materials with high electron transport properties, electron-blocking materials, materials with high electron injection properties, or bipolar materials (materials with high electron and hole transport properties). For example, a light-emitting device can have a configuration that includes, in addition to the light-emitting layer, one or more layers from among hole injection layers, hole transport layers, hole-blocking layers, charge generation layers, electron-blocking layers, electron transport layers, and electron injection layers.

[0523] 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.

[0524] The light-emitting layer has one or more types of light-emitting materials. The light-emitting materials may include those exhibiting colors such as blue, purple, blue-violet, green, yellow-green, yellow, orange, or red. Furthermore, materials that emit near-infrared light may also be used as light-emitting materials.

[0525] Examples of luminescent materials include fluorescent materials, phosphorescent materials, TADF materials, and quantum dot materials.

[0526] Examples of fluorescent materials include pyrene derivatives, anthracene derivatives, triphenylene derivatives, fluorene derivatives, carbazole derivatives, dibenzothiophene derivatives, dibenzofuran derivatives, dibenzoquinoxaline derivatives, quinoxaline derivatives, pyridine derivatives, pyrimidine derivatives, phenanthrene derivatives, and naphthalene derivatives.

[0527] Examples of phosphorescent materials include organometallic complexes (especially iridium complexes) having a 4H-triazole skeleton, 1H-triazole skeleton, imidazole skeleton, pyrimidine skeleton, pyrazine skeleton, or pyridine skeleton; organometallic complexes (especially iridium complexes) using phenylpyridine derivatives having electron-withdrawing groups as ligands; platinum complexes; and rare earth metal complexes.

[0528] The light-emitting layer may contain one or more types of organic compounds (host material, assist material, etc.) in addition to the light-emitting substance (guest material). One or more types of organic compounds may include one or both of a material with high hole transport properties (hole transport material) and a material with high electron transport properties (electron transport material). As the hole transport material, one of the materials with high hole transport properties that can be used in the hole transport layer, as described later, may be used. As the electron transport material, one of the materials with high electron transport properties that can be used in the electron transport layer, as described later, may be used. Furthermore, one or more types of organic compounds may include bipolar materials or TADF materials.

[0529] 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.

[0530] 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 properties. Examples of materials with high hole injection properties include aromatic amine compounds and composite materials containing hole transport materials and acceptor materials (electron-accepting materials).

[0531] As the hole-transporting material, a material with high hole-transporting properties that can be used in the hole-transporting layer, as described later, can be used.

[0532] As the acceptor material, for example, oxides of metals belonging to Groups 4 to 8 in the periodic table of elements can be used. Specific examples include molybdenum oxide, vanadium oxide, niobium oxide, tantalum oxide, chromium oxide, tungsten oxide, manganese oxide, and rhenium oxide. Among these, molybdenum oxide is particularly preferred because it is stable in air, has low hygroscopicity, and is easy to handle. Fluorine-containing organic acceptor materials can also be used. Furthermore, organic acceptor materials such as quinodimethane derivatives, chloranil derivatives, and hexaazatriphenylene derivatives can also be used.

[0533] For example, as a material with high hole injection properties, a material comprising a hole-transporting material and an oxide of a metal belonging to Groups 4 to 8 in the aforementioned periodic table of elements (typically molybdenum oxide) may be used.

[0534] The hole transport layer is a layer that transports holes injected from the anode through the hole injection layer to the light-emitting layer. The hole transport layer is a layer containing a hole-transporting material. As the hole-transporting material, 1×10 -6 cm 2 A substance having a hole mobility of / Vs or more is preferred. It should be noted that any substance other than those listed above may also be used as long as it has higher hole transportability than electron transportability. As the hole-transporting material, materials with high hole transportability are preferred, such as π-electron-rich heteroaromatic compounds (e.g., carbazole derivatives, thiophene derivatives, furan derivatives, etc.), aromatic amines (compounds having an aromatic amine skeleton), and the like.

[0535] The electron blocking layer is provided in contact with the light-emitting layer. The electron blocking layer is a layer containing a material that has hole transportability and is capable of blocking electrons. A material having electron blocking properties among the aforementioned hole-transporting materials can be used for the electron blocking layer.

[0536] Since the electron blocking layer has hole transportability, it can also be referred to as a hole transport layer. Furthermore, a layer having electron blocking properties among hole transport layers can also be referred to as an electron blocking layer.

[0537] The electron transport layer is a layer that transports electrons injected from the cathode by the electron injection layer to the light-emitting layer. The electron transport layer is a layer containing an electron-transporting material. The electron-transporting material is 1 × 10⁻¹⁶ -6 cm 2 Materials having an electron mobility of / Vs or higher are preferred. However, other materials can also be used as long as they have higher electron transport capabilities than holes. Examples of electron-transporting materials include metal complexes having a quinoline skeleton, metal complexes having a benzoquinoline skeleton, metal complexes having an oxazole skeleton, 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.

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

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

[0540] 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.

[0541] Furthermore, it is preferable that the LUMO level of a material with high electron injection capacity has a small difference (specifically, 0.5 eV or less) from the work function value of the material used as the cathode.

[0542] The electron injection layer contains, for example, lithium, cesium, ytterbium, lithium fluoride (LiF), cesium fluoride (CsF), and calcium fluoride (CaF). x (where X is any number), 8-(quinolinolato)lithium (abbreviation: Liq), 2-(2-pyridyl)phenolatrium (abbreviation: LiPP), 2-(2-pyridyl)-3-pyridinolatrium (abbreviation: LiPPy), 4-phenyl-2-(2-pyridyl)phenolatrium (abbreviation: LiPPP), lithium oxide (LiO x Alkali metals such as cesium carbonate, alkaline earth metals, or compounds thereof can be used. The electron injection layer may also be a multilayer structure of two or more layers. For example, a multilayer structure in which lithium fluoride is used as the first layer and ytterbium is provided as the second layer can be used.

[0543] The electron injection layer may contain an electron-transporting material. For example, a compound having a lone pair of electrons and an electron-deficient heteroaromatic ring can be used as the electron-transporting material. Specifically, a compound having at least one of a pyridine ring, a diazine ring (pyrimidine ring, pyrazine ring, pyridazine ring), or a triazine ring can be used.

[0544] Furthermore, the lowest unoccupied molecular orbital (LUMO) level of organic compounds containing lone pairs of electrons is preferably between -3.6 eV and -2.3 eV. In general, the highest occupied molecular orbital (HOMO) level and LUMO level of organic compounds can be estimated by methods such as cyclic voltammetry (CV), photoelectron spectroscopy, optical absorption spectroscopy, and inverse photoelectron spectroscopy.

[0545] 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), 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.

[0546] As described above, the charge generation layer has at least a charge generation region. The charge generation region preferably contains an acceptor material, and preferably contains, for example, a hole transport material and an acceptor material applicable to the hole injection layer described above.

[0547] Furthermore, the charge generation layer preferably includes a layer containing a material with high electron injection potential. This layer can also be called an electron injection buffer layer. The electron injection buffer layer is preferably provided between the charge generation region and the electron transport layer. By providing an electron injection buffer layer, the injection barrier between the charge generation region and the electron transport layer can be relaxed, allowing electrons generated in the charge generation region to be easily injected into the electron transport layer.

[0548] The electron injection buffer layer preferably contains an alkali metal or an alkaline earth metal, and can, for example, be configured to contain an alkali metal compound or an alkaline earth metal compound. Specifically, the electron injection buffer layer preferably has an inorganic compound containing an alkali metal and oxygen, or an inorganic compound containing an alkaline earth metal and oxygen, and more preferably has an inorganic compound containing lithium and oxygen (such as lithium oxide (Li2O)). In addition, any other material applicable to the electron injection layer described above can be suitably used for the electron injection buffer layer.

[0549] The charge generation layer preferably has a layer containing a material with high electron transport properties. This layer can also be called an electron relay layer. The electron relay layer is preferably provided between the charge generation region and the electron injection buffer layer. If the charge generation layer does not have an electron injection buffer layer, the electron relay layer is preferably provided between the charge generation region and the electron transport layer. The electron relay layer has the function of preventing interaction between the charge generation region and the electron injection buffer layer (or electron transport layer) and smoothly transferring electrons.

[0550] As the electron relay layer, it is preferable to use a phthalocyanine-based material such as copper(II) phthalocyanine (abbreviated as CuPc), or a metal complex having a metal-oxygen bond and an aromatic ligand.

[0551] Furthermore, the charge generation region, electron injection buffer layer, and electron relay layer described above may not be clearly distinguishable depending on their cross-sectional shape or characteristics.

[0552] The charge generation layer may have a donor material instead of an acceptor material. For example, the charge generation layer may have a layer containing an electron transport material and a donor material, which is applicable to the electron injection layer described above.

[0553] When stacking light-emitting units, the rise in driving voltage can be suppressed by providing a charge generation layer between the two light-emitting units.

[0554] This embodiment can be combined with other embodiments as appropriate.

[0555] (Embodiment 6) In this embodiment, an electronic device according to one aspect of the present invention will be described with reference to Figures 31 to 33.

[0556] The electronic device of this embodiment has a display device according to one aspect of the present invention in its display unit. The display device according to one aspect of the present invention is easily made high-definition and high-resolution. Therefore, it can be used in the display units of various electronic devices.

[0557] 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.

[0558] In particular, a display device according to one aspect of the present invention can be used suitably in electronic devices having a relatively small display area because it can increase the resolution. Examples of such electronic devices include wristwatch-type and bracelet-type information terminals (wearable devices), as well as wearable devices that can be worn on the head, such as VR devices such as head-mounted displays, AR devices such as glasses, and MR devices.

[0559] A display device according to one aspect of the present invention preferably has an extremely high resolution such as HD (1280 x 720 pixels), FHD (1920 x 1080 pixels), WQHD (2560 x 1440 pixels), WQXGA (2560 x 1600 pixels), 4K (3840 x 2160 pixels), or 8K (7680 x 4320 pixels). In particular, a resolution of 4K, 8K, or higher is preferred. Furthermore, the pixel density (resolution) of the display device according to one aspect of the present invention is preferably 100 ppi or more, preferably 300 ppi or more, more preferably 500 ppi or more, more preferably 1000 ppi or more, more preferably 2000 ppi or more, more preferably 3000 ppi or more, more preferably 5000 ppi or more, and even more preferably 7000 ppi or more. By using a display device having either high resolution or high detail, or both, it becomes possible to further enhance the sense of presence and depth. Furthermore, there are no particular limitations on the screen ratio (aspect ratio) of the display device according to one embodiment of the present invention. For example, the display device can support various screen ratios such as 1:1 (square), 4:3, 16:9, and 16:10.

[0560] The electronic device of this embodiment may have sensors (including functions for detecting, detecting, or 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).

[0561] 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.

[0562] Figures 31A to 31D illustrate an example of a wearable device that can be worn on the head. These wearable devices have at least one of the following functions: a function to display AR content, a function to display VR content, a function to display SR content, or a function to display MR content. By having an electronic device that has the function to display at least one of the following types of content, such as AR, VR, SR, or MR, it is possible to enhance the user's sense of immersion.

[0563] The electronic device 700A shown in Figure 31A and the electronic device 700B shown in Figure 31B 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.

[0564] A display device 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.

[0565] 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.

[0566] 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.

[0567] 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.

[0568] Furthermore, electronic devices 700A and 700B are equipped with batteries that can be charged wirelessly, wired, or both.

[0569] 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.

[0570] 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.

[0571] 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.

[0572] The electronic device 800A shown in Figure 31C and the electronic device 800B shown in Figure 31D 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.

[0573] A display device 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.

[0574] 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.

[0575] Electronic devices 800A and 800B can be described as electronic devices for VR. A user wearing electronic device 800A or electronic device 800B can view the image displayed on the display unit 820 through the lens 832.

[0576] 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.

[0577] The attachment portion 823 allows the user to attach the electronic device 800A or 800B to their head. While the attachment portion 823 is exemplified in Figure 31C and other figures as resembling the temples (or arms) of eyeglasses, it is not limited to this. The attachment portion 823 only needs to be wearable by the user; for example, it may be helmet-shaped or band-shaped.

[0578] 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.

[0579] 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 the detection unit. As the detection unit, for example, an image sensor or a distance image sensor such as LiDAR (Light Detection and Ranging) can be used. By using the image obtained by the camera and the image obtained by the distance image sensor, more information can be acquired, enabling more accurate gesture control.

[0580] 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.

[0581] 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.

[0582] 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 31A 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 31C has a function for transmitting information to the earphone 750 through its wireless communication function.

[0583] Furthermore, the electronic device may have an earphone section. The electronic device 700B shown in Figure 31B has an earphone section 727. For example, the earphone section 727 and the control unit can be connected to each other by a wire. Part of the wiring connecting the earphone section 727 and the control unit may be located inside the housing 721 or the mounting section 723.

[0584] Similarly, the electronic device 800B shown in Figure 31D has an earphone unit 827. For example, the earphone unit 827 and the control unit 824 can be connected to each other by a wire. Part of the wiring connecting the earphone unit 827 and the control unit 824 may be located inside the housing 821 or the mounting unit 823. Also, the earphone unit 827 and the mounting unit 823 may have magnets. This allows the earphone unit 827 to be fixed to the mounting unit 823 by magnetic force, which is preferable as it facilitates storage.

[0585] 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.

[0586] Thus, as one embodiment of the present invention, both eyeglass-type (electronic device 700A, electronic device 700B, etc.) and goggle-type (electronic device 800A, electronic device 800B, etc.) are preferred as electronic devices.

[0587] Furthermore, an electronic device according to one aspect of the present invention can transmit information to earphones via wired or wireless means.

[0588] The electronic device 6500 shown in Figure 32A is a portable information terminal that can be used as a smartphone.

[0589] 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, a light source 6508, and the like. The display unit 6502 has a touch panel function.

[0590] A display device according to one aspect of the present invention can be applied to the display unit 6502.

[0591] Figure 32B is a schematic cross-sectional view of the housing 6501, including the end on the microphone 6506 side.

[0592] 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.

[0593] 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).

[0594] 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.

[0595] A flexible display device according to one embodiment of the present invention can be applied to the display panel 6511. As a result, an extremely lightweight electronic device can be realized. Furthermore, because the display panel 6511 is extremely thin, a large-capacity battery 6518 can be installed 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 side of the display unit 6502, an electronic device with a narrow bezel can be realized.

[0596] Figure 32C 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 supported by a stand 7103.

[0597] A display device according to one embodiment of the present invention can be applied to the display unit 7000.

[0598] The television device 7100 shown in Figure 32C 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.

[0599] 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.

[0600] Figure 32D 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.

[0601] A display device according to one embodiment of the present invention can be applied to the display unit 7000.

[0602] Figures 32E and 32F show examples of digital signage.

[0603] The digital signage 7300 shown in Figure 32E 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.

[0604] Figure 32F 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.

[0605] In Figures 32E and 32F, a display device according to one embodiment of the present invention can be applied to the display unit 7000.

[0606] 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.

[0607] 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.

[0608] Furthermore, as shown in Figures 32E and 32F, 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.

[0609] 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.

[0610] The electronic equipment shown in Figures 33A to 33G 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 detecting, detecting, or 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.

[0611] In Figures 33A to 33G, a display device according to one embodiment of the present invention can be applied to the display unit 9001.

[0612] The electronic devices shown in Figures 33A to 33G 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.

[0613] Details of the electronic equipment shown in Figures 33A to 33G will be explained below.

[0614] Figure 33A 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 33A shows an example where three icons 9050 are displayed. Information 9051, indicated by a dashed rectangle, can also be displayed on other surfaces of the display unit 9001. Examples of information 9051 include notifications of incoming emails, SNS messages, phone calls, etc., the subject of an email or SNS message, the sender's name, date and time, time, battery level, signal strength, etc. Alternatively, icons 9050, etc., may be displayed in the location where information 9051 is displayed.

[0615] Figure 33B is a perspective view showing the personal digital assistant (PDA) 9102. The PDA 9102 has the function of displaying information on three or more sides of the display unit 9001. Here, an example is shown in which information 9052, information 9053, and information 9054 are displayed on different sides. For example, a user can check information 9053, which is displayed in a position that can be observed from above the PDA 9102, while the PDA 9102 is stored in the breast pocket of their clothing. The user can check the display without taking the PDA 9102 out of their pocket and decide, for example, whether or not to answer a call.

[0616] Figure 33C is a perspective view showing the tablet terminal 9103. The tablet terminal 9103 can run various applications, such as mobile phone calls, email, document viewing and creation, music playback, internet communication, and computer games. The tablet terminal 9103 has a display unit 9001, a camera 9002, a microphone 9008, and a speaker 9003 on the front of the housing 9000, operation keys 9005 as buttons for operation on the side of the housing 9000, and connection terminals 9006 on the bottom.

[0617] Figure 33D is a perspective view showing a wristwatch-type personal information terminal 9200. The personal information terminal 9200 can be used, for example, as a smartwatch (registered trademark). The display unit 9001 has a curved display surface, allowing it to display information along the curved surface. The personal information terminal 9200 can also make hands-free calls by communicating with, for example, a wireless communication headset. Furthermore, the personal information terminal 9200 can transmit data to other information terminals and be charged via a connection terminal 9006. Charging may be performed by wireless power supply.

[0618] Figures 33E to 33G are perspective views showing a foldable personal information terminal 9201. Figure 33E shows the personal information terminal 9201 in an unfolded state, Figure 33G shows it in a folded state, and Figure 33F shows a perspective view of the state in between, transitioning from one of Figures 33E or 33G to the other. The personal information terminal 9201 offers excellent portability in its folded state and excellent readability of the display due to its seamless, wide display area in its unfolded state. The display unit 9001 of the personal information terminal 9201 is supported by three housings 9000 connected by a hinge 9055. For example, the display unit 9001 can be bent with a radius of curvature of 0.1 mm to 150 mm.

[0619] This embodiment can be combined with other embodiments as appropriate. [Explanation of Symbols]

[0620] 11B: sub-pixel, 11G: sub-pixel, 11R: sub-pixel, 100A: display device, 100B: display device, 100C: display device, 100D: display device, 100E: display device, 100F: display device, 100G: display device, 100H: display device, 100: display device, 101: layer, 103: region, 110a: sub-pixel, 110b: sub-pixel, 110c: sub-pixel, 110d: sub-pixel, 110: pixel, 111B: pixel electrode, 111G: pixel electrode, 111R: pixel electrode, 112B: conductive layer, 112G: conductive layer, 112R: conductive layer, 113b: material layer, 113s: material layer, 113t : Region, 113B: EL layer, 113: EL layer, 114A: Insulating film, 114: Sidewall insulating layer, 115: Common electrode, 116B: Optical adjustment layer, 116G: Optical adjustment layer, 116R: Optical adjustment layer, 117: Light-shielding layer, 120: Substrate, 122: Resin layer, 123: Conductive layer, 124a: Pixel, 124b: Pixel, 125A: Insulating film, 125B: Insulating layer, 125: Insulating layer, 126B: Conductive layer, 126G: Conductive layer, 126R: Conductive layer, 127a: Insulating film, 127b: Insulating layer, 127: Insulating layer, 128: Layer, 129B: Conductive layer, 129G: Conductive layer, 129R: Conductive layer, 130B: Light-emitting diode Vice, 130G: Light-emitting device, 130R: Light-emitting device, 131: Protective layer, 132B: Coloring layer, 132G: Coloring layer, 132R: Coloring layer, 133: Lens, 134: Insulating layer, 135: Insulating layer, 136: Mask, 137B: Light-emitting device, 137G: Light-emitting device, 137R: Light-emitting device, 139: Light, 140: Connection part, 142: Adhesive layer, 150A: Area, 150B: Area, 150C: Area, 150D: Area, 150E: Area, 150F: Area, 151: Substrate, 152: Substrate, 153: Insulating layer, 154B: Sub-pixel, 154G: Sub-pixel, 154R: Sub-pixel ,155B: sub-pixel, 155G: sub-pixel, 155R: sub-pixel, 162: display area, 164: circuit, 165: wiring, 166: conductive layer, 171: light shielding layer, 172: FPC, 173: IC, 175G: color conversion layer, 175R: color conversion layer, 201: transistor, 204: connection area, 205: transistor, 209: transistor, 210: transistor, 211: insulating layer, 213: insulating layer, 214: insulating layer, 215: insulating layer, 218: insulating layer, 221: conductive layer, 222a: conductive layer, 222b: conductive layer, 223: conductive layer, 225: insulating layer, 231i: channel formation region,231n: Low resistance region, 231: Semiconductor layer, 240: Capacitance, 241: Conductive layer, 242: Connection layer, 243: Insulating layer, 245: Conductive layer, 251: Conductive layer, 252: Conductive layer, 254: Insulating layer, 255a: Insulating layer, 255b: Insulating layer, 255c: Insulating layer, 256: Plug, 261: Insulating layer, 262: Insulating layer, 263: Insulating layer, 264: Insulating layer, 265: Insulating layer, 271: Plug, 274a: Conductive layer, 274b: Conductive layer, 274: Plug, 280: Display module, 281: Display unit, 282: Circuit unit, 283a: Pixel circuit, 283: Pixel circuit unit, 284a: Pixel, 284: Pixel section, 285: Terminal section, 286: Wiring section, 290: FPC, 291: Substrate, 292: Substrate, 301A: Substrate, 301B: Substrate, 301: Substrate, 310A: Transistor, 310B: Transistor, 310: Transistor, 311: Conductive layer, 312: Low resistance region, 313: Insulating layer, 314: Insulating layer, 315: Element isolation layer, 320A: Transistor, 320B: Transistor, 320: Transistor, 321: Semiconductor layer, 323: Insulating layer, 324: Conductive layer, 325: Conductive layer, 326: Insulating layer, 327: Conductive layer, 328: Insulating layer, 329: Insulating layer, 3 31: Substrate, 332: Insulating layer, 335: Insulating layer, 336: Insulating layer, 341: Conductive layer, 342: Conductive layer, 343: Plug, 344: Insulating layer, 345: Insulating layer, 346: Insulating layer, 347: Bump, 348: Adhesive layer, 700A: Electronic equipment, 700B: Electronic equipment, 721: Housing, 723: Mounting part, 727: Earphone part, 750: Earphone, 751: Display panel, 753: Optical component, 756: Display area, 757: Frame, 758: Nose pad, 761: Lower electrode, 762: Upper electrode, 763a: Light-emitting unit, 763b: Light-emitting unit, 763c: Light-emitting unit T, 763: EL layer, 764: layer, 771a: light-emitting layer, 771b: light-emitting layer, 771c: light-emitting layer, 771: light-emitting layer, 772a: light-emitting layer, 772b: light-emitting layer, 772c: light-emitting layer, 772: light-emitting layer, 773: light-emitting layer, 780a: layer, 780b: layer, 780c: layer, 780: layer, 781: layer, 782: layer, 785: charge generation layer, 790a: layer, 790b: layer, 790c: layer, 790: layer, 791: layer, 792: layer, 800A: electronic equipment, 800B: electronic equipment, 820: display unit, 821: housing, 822: communication unit, 823: mounting unit, 824: control unit, 825: imaging unit,827: Earphone unit, 832: Lens, 6500: Electronic equipment, 6501: Housing, 6502: Display unit, 6503: Power button, 6504: Button, 6505: Speaker, 6506: Microphone, 6507: Camera, 6508: Light source, 6510: Protective component, 6511: Display panel, 6512: Optical component, 6513: Touch sensor panel, 6515: FPC, 6516: IC, 6517: Printed circuit board, 6518: Battery, 7000: Display unit, 7100: Television equipment, 7101: Housing, 7103: Stand, 7111: Remote control unit, 7200: Notebook personal computer, 7211: Housing, 7212: Keyboard, 7213: Point 7214: External connection port, 7300: Digital signage, 7301: Enclosure, 7303: Speaker, 7311: Information terminal, 7400: Digital signage, 7401: Pillar, 7411: Information terminal, 9000: Enclosure, 9001: Display unit, 9002: Camera, 9003: Speaker, 9005: Operation key, 9006: Connection terminal, 9007: Sensor, 9008: Microphone, 9050: Icon, 9051: Information, 9052: Information, 9053: Information, 9054: Information, 9055: Hinge, 9101: Portable information terminal, 9102: Portable information terminal, 9103: Tablet terminal, 9200: Portable information terminal, 9201: Portable information terminal,

Claims

1. It comprises a first light-emitting device, a second light-emitting device, a first sidewall insulating layer, a second sidewall insulating layer, a first insulating layer, a first colored layer, and a second colored layer. The first light-emitting device comprises a first pixel electrode, a first EL layer on the first pixel electrode, and a common electrode on the first EL layer. The second light-emitting device comprises a second pixel electrode, a second EL layer on the second pixel electrode, and the common electrode on the second EL layer. The first EL layer and the second EL layer each comprise a first light-emitting material that emits blue light and a second light-emitting material that emits light with a longer wavelength than blue light. The first sidewall insulating layer has a region that is in contact with the side surface of the first pixel electrode, The second sidewall insulating layer has a region that is in contact with the side surface of the second pixel electrode, The first insulating layer has a region in contact with the upper surface of the first EL layer, a region in contact with the side surface of the first EL layer, a region in contact with the upper surface of the second EL layer, a region in contact with the side surface of the second EL layer, a region in contact with the side surface of the first sidewall insulating layer, and a region in contact with the side surface of the second sidewall insulating layer. The first colored layer overlaps with the first light-emitting device. The second colored layer overlaps with the second light-emitting device. The first colored layer and the second colored layer each have the function of transmitting light of different colors. Display device.

2. In claim 1, Between the first light-emitting device and the second light-emitting device, there is a material layer isolated from the first EL layer and the second EL layer. The material layer comprises the first light-emitting material and the second light-emitting material. Display device.

3. In claim 2, The first sidewall insulating layer and the second sidewall insulating layer each have an inorganic insulating material. Display device.

4. In claim 3, The first insulating layer has a tapered shape at its end. Display device.

5. In claim 1, In a cross-sectional view, the upper end of the first pixel electrode and the upper end of the first sidewall insulating layer have a contact region. Display device.

6. In claim 1, In a cross-sectional view, the upper end of the second pixel electrode and the upper end of the second sidewall insulating layer have a contact region. Display device.

Images