Indication device

Abstract

A display device with high display quality is provided. This display device has a first light-emitting device, a second light-emitting device, and an insulating layer. The first light-emitting device has a first pixel electrode, a first EL layer, and a common electrode. The second light-emitting device has a second pixel electrode, a second EL layer, and the common electrode. The insulating layer has a first surface that has an opening and is in contact with the side surface of the first pixel electrode, a second surface facing the first surface, and a third surface in contact with the lower surface of the first EL layer. The third surface and the upper surface of the first pixel electrode have regions where the heights thereof match or substantially match each other. In a cross-sectional view, the angle formed by the second surface and the third surface is 80-110 degrees. The first EL layer has the same material as the second EL layer. The first EL layer is separated from the second EL layer.

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] It should be noted that one aspect of the present invention is not limited to the above-mentioned technical field. Examples of technical fields of one aspect of the present invention include semiconductor devices, display devices, light-emitting devices, energy storage devices, memory devices, electronic devices, lighting devices, input devices (e.g., touch sensors), input / output devices (e.g., touch panels), methods for driving them, or methods for manufacturing them. [Background technology]

[0003] Display devices are 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 mobile information terminals such as smartphones and tablet devices equipped with touch panels.

[0004] In recent years, there has been a growing demand for display devices applicable to virtual reality (VR), augmented reality (AR), substitutional reality (SR), or mixed reality (MR). VR, AR, SR, and MR are collectively referred to as xR (Extended Reality). Display devices for xR are desired to have high resolution and high color reproduction in order to enhance the sense of realism and immersion.

[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 project] [Problems that the invention aims to solve]

[0008] One aspect of the present invention aims to provide a display device with high display quality. One aspect of the present invention aims to provide a high-definition display device. One aspect of the present invention aims to provide a high-resolution display device. One 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 is a display device having a first light-emitting device, a second light-emitting device, and an insulating layer. The first light-emitting device has 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 has a second pixel electrode, a second EL layer on the second pixel electrode, and a common electrode on the second EL layer. The insulating layer has an opening. The insulating layer has a first surface in contact with the side surface of the first pixel electrode, a second surface facing the first surface, a third surface in contact with the lower surface of the first EL layer, a fourth surface in contact with the side surface of the second pixel electrode, a fifth surface facing the fourth surface, and a sixth surface in contact with the lower surface of the second EL layer. The heights of the third surface, the sixth surface, the top surface of the first pixel electrode, and the top surface of the second pixel electrode have a region where they coincide or approximately coincide with each other. In cross-sectional view, the angle between the second surface and the third surface is between 80° and 110°. The first EL layer has the same material as the second EL layer. The first EL layer is separated from the second EL layer.

[0012] In the aforementioned display device, the ratio of the depth of the opening to the thickness of the first EL layer is preferably 0.5 or more and 10.0 or less.

[0013] In the aforementioned display device, the aperture width is preferably 50 nm or more and 500 nm or less.

[0014] In the aforementioned display device, it is preferable to have a first colored layer and a second colored layer. The first colored layer preferably has a region that overlaps with the first light-emitting device. The second colored layer preferably has a region that overlaps with the second light-emitting device. The light transmitted by the second colored layer preferably has a shorter wavelength than the light transmitted by the first colored layer.

[0015] In the aforementioned display device, it is preferable to have a first conductive layer and a second conductive layer. It is preferable that the first conductive layer and the second conductive layer each transmit visible light. It is preferable that the first conductive layer is sandwiched between a first pixel electrode and a first EL layer. It is preferable that the second conductive layer is sandwiched between a second pixel electrode and a second EL layer. It is preferable that the thickness of the second conductive layer is thinner than the thickness of the first conductive layer.

[0016] In the aforementioned display device, it is preferable that the side surface of the first conductive layer is aligned with or approximately aligned with the second surface. It is also preferable that the side surface of the second conductive layer is aligned with or approximately aligned with the fifth surface.

[0017] One aspect of the present invention is a method for manufacturing a display device, comprising: forming a first pixel electrode and a second pixel electrode; forming an insulating film covering the upper and side surfaces of the first and second pixel electrodes; removing a portion of the insulating film; forming an insulating layer whose height matches or approximately matches the height of the upper surface of the first pixel electrode and the upper surface of the second pixel electrode; forming an opening in the insulating layer; forming a first EL layer on the first pixel electrode and forming a second EL layer on the second pixel electrode that is separate from the first EL layer; and forming a common electrode on the first EL layer and the second EL layer. The insulating layer has a first surface in contact with the side surface of the first pixel electrode, a second surface facing the first surface, and a third surface in contact with the lower surface of the first EL layer. The insulating layer has a region in which the height of the third surface matches or approximately matches the height of the upper surface of the first pixel electrode. In cross-sectional view, the angle between the second surface and the third surface is 80° or more and 110° or less. The first EL layer has the same material as the second EL layer. [Effects of the Invention]

[0018] According to one aspect of the present invention, a display device with high display quality can be provided. According to one aspect of the present invention, a high-definition display device can be provided. According to one aspect of the present invention, a high-resolution display device can be provided. According to one aspect of the present invention, a highly reliable display device can be provided.

[0019] According to one aspect of the present invention, a method for manufacturing a high-definition display device can be provided. According to one aspect of the present invention, a method for manufacturing a high-resolution display device can be provided. According to one aspect of the present invention, a method for manufacturing a highly reliable display device can be provided. According to one aspect of the present invention, a method for manufacturing a display device with a high yield can be provided.

[0020] Note that the description of these effects does not prevent the existence of other effects. One aspect of the present invention does not necessarily have to have all of these effects. It is possible to extract other effects from the description of the specification, drawings, and claims.

Brief Description of the Drawings

[0021] FIG. 1A is a top view showing an example of a display device. FIG. 1B is a cross-sectional view showing an example of a display device. FIG. 2 is a cross-sectional view showing an example of a display device. FIGS. 3A and 3B are cross-sectional views showing an example of a display device. FIGS. 4A and 4B are cross-sectional views showing an example of a display device. FIGS. 5A and 5B are cross-sectional views showing an example of a display device. FIG. 6 is a cross-sectional view showing an example of a display device. FIGS. 7A and 7B are cross-sectional views showing an example of a display device. FIGS. 8A and 8B are cross-sectional views showing an example of a display device. FIGS. 9A and 9B are cross-sectional views showing an example of a display device. FIGS. 10A to 10C are cross-sectional views showing an example of a display device. FIG. 11 is a cross-sectional view showing an example of a display device. FIGS. 12A to 12E are cross-sectional views showing an example of a method for manufacturing a display device. FIGS. 13A to 13C are cross-sectional views showing an example of a method for manufacturing a display device. FIGS. 14A to 14C are cross-sectional views showing an example of a method for manufacturing a display device. FIGS. 15A to 15G are diagrams showing an example of a pixel. Figures 16A to 16K show examples of pixels. Figures 17A and 17B are perspective views showing an example of a display device. Figure 18 is a cross-sectional view showing an example of a display device. Figure 19 is a cross-sectional view 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 perspective view showing an example of a display device. Figure 25A is a cross-sectional view showing an example of a display device. Figures 25B and 25C are cross-sectional views showing an example of a transistor. Figure 26 is a cross-sectional view showing an example of a display device. Figures 27A to 27F show examples of the configuration of a light-emitting device. Figures 28A to 28C show examples of the configuration of a light-emitting device. Figures 29A to 29D show examples of electronic devices. Figures 30A to 30F show examples of electronic devices. Figures 31A to 31G show examples of electronic devices. [Modes for carrying out the invention]

[0022] Embodiments will be described in detail 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. Accordingly, the present invention shall not be construed as being limited to the descriptions of the embodiments shown below.

[0023] In the configuration of the invention described below, the same reference numerals are used in common across different drawings for identical parts or parts having similar functions, and repeated explanations are omitted. Furthermore, when referring to similar functions, the hatch patterns are the same, and reference numerals may not be assigned.

[0024] 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.

[0025] The words "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."

[0026] In this specification, devices fabricated using a metal mask or an FMM (Fine Metal Mask, a high-resolution metal mask) may be referred to as MM (Metal Mask) structured devices. Furthermore, in this specification, devices fabricated without using a metal mask or an FMM may be referred to as MML (Metal Maskless) structured devices.

[0027] In this specification, a structure that creates separate light-emitting layers for light-emitting devices with different emission wavelengths may be referred to as an SBS (Side By Side) structure. Because the SBS structure allows for the optimization of materials and configurations for each light-emitting device, it increases the freedom of material and configuration selection, making it easier to improve brightness and reliability.

[0028] In this specification, holes or electrons may be referred to as "carriers." Specifically, a hole injection layer or electron injection layer may be called a "carrier injection layer," a hole transport layer or electron transport layer may be called a "carrier transport layer," and a hole block layer or electron block layer may be called a "carrier block layer." Note that the above-mentioned carrier injection layer, carrier transport layer, and carrier block layer may not be clearly distinguishable by their cross-sectional shape or characteristics. Furthermore, a single layer may combine the functions of two or three of these carrier injection, carrier transport, and carrier block layers.

[0029] In this specification, a light-emitting device (also called a light-emitting element) has an EL layer between a pair of electrodes. The EL layer has at least a light-emitting layer. Examples of layers (also called functional layers) that make up the EL layer include a light-emitting layer, a carrier injection layer (hole injection layer and electron injection layer), a carrier transport layer (hole transport layer and electron transport layer), and a carrier 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.

[0030] 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. For example, it is preferable to have a region in which the angle between the inclined side surface and the substrate surface (also called the taper angle) is less than 90°. The side surface of the structure and the substrate surface do not necessarily have to be perfectly flat; they may be substantially planar with a small curvature, or substantially planar with fine irregularities.

[0031] (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 14.

[0032] A display device according to one aspect of the present invention has a plurality of pixels, and each pixel has a plurality of sub-pixels. In a display device according to one aspect of the present invention, each sub-pixel has a light-emitting device and a colored layer. Each light-emitting device has an EL layer containing the same material. The colored layer is provided in a region that overlaps with the light-emitting device. By providing a colored layer that transmits visible light of different colors in the sub-pixel, the display device can perform full-color display.

[0033] When using light-emitting devices with the same EL layer configuration, 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 are relatively highly conductive. When multiple subpixels share a highly conductive layer as a continuous film, leakage current may occur between the 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 non-negligible, potentially leading to a decrease in the display quality of the display device.

[0034] A display device according to one aspect of the present invention has an island-shaped EL layer for each light-emitting device. By separating the EL layer for each light-emitting device, the occurrence of crosstalk between adjacent subpixels can be suppressed. This makes it possible to achieve both high resolution and high display quality in the display device.

[0035] In this specification, "island-like" refers to two or more layers formed using the same material and process that are physically separated. For example, an island-like EL layer refers to an EL layer that is physically separated from an adjacent EL layer.

[0036] 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. This makes it difficult to increase the resolution and aperture ratio of the display device. 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. 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.

[0037] 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 such as a metal mask. Specifically, an insulating layer is provided between the pixel electrodes, and after forming an opening in the insulating layer, an EL layer is deposited over multiple pixel electrodes. When the EL layer is deposited, the EL layer is separated into island shapes by the step created by the opening, and one island-shaped EL layer is formed for each pixel electrode. In other words, an island-shaped EL layer can be formed for each sub-pixel.

[0038] By forming the EL layer in an island shape, functional layers other than the light-emitting layer (for example, carrier injection layer, carrier transport layer, or carrier block layer, more specifically hole injection layer, hole transport layer, electron block layer, etc.) are also formed in an island shape. By processing the functional layers in an island shape, it is possible to reduce the leakage current (sometimes called lateral leakage current, transverse leakage current, or lateral leakage current) that may occur between adjacent subpixels. For example, when a hole injection layer is used in common between adjacent subpixels, a transverse leakage current may be generated due to the hole injection layer. On the other hand, in a display device according to one aspect of the present invention, since the hole injection layer can be processed in an island shape, a transverse leakage current between adjacent subpixels can be substantially eliminated or made extremely small.

[0039] Here, if each process performed after the deposition of the EL layer is carried out at a temperature higher than the heat resistance temperature of the EL layer, the EL layer may degrade, potentially reducing the luminous efficiency and reliability of the light-emitting device.

[0040] Therefore, in one embodiment of the present invention, the heat resistance temperature of the compounds contained in the light-emitting device is preferably 100°C or more and 180°C or less, preferably 120°C or more and 180°C or less, and more preferably 140°C or more and 180°C or less.

[0041] Indicators of heat resistance temperature include, for example, the glass transition temperature (Tg), softening point, melting point, thermal decomposition temperature, and 5% weight loss temperature. For example, the glass transition temperature of the material in each layer constituting the EL layer can be used as an indicator of the heat resistance temperature of that layer. In the case of a mixed layer consisting of multiple materials, for example, the glass transition temperature of the most abundant material can be used. Alternatively, the lowest temperature among the glass transition temperatures of the multiple materials may be used.

[0042] In particular, it is preferable to increase the heat resistance temperature of the functional layer provided on the light-emitting layer. Furthermore, it is even more preferable to increase the heat resistance temperature of the functional layer provided in contact with the light-emitting layer. The high heat resistance of the functional layer makes it possible to effectively protect the light-emitting layer and reduce the damage it receives.

[0043] In particular, it is preferable to increase the heat resistance temperature of the light-emitting layer. This helps to prevent damage to the light-emitting layer due to heating, which can reduce luminous efficiency and shorten its lifespan.

[0044] By increasing the heat resistance temperature of light-emitting devices, their reliability can be improved. Furthermore, the temperature range in the manufacturing process of display devices can be broadened, leading to improved manufacturing yield and reliability.

[0045] In this embodiment, a display device according to one aspect of the present invention will be described.

[0046] <Configuration Example 1> Figure 1A shows a top view of a display device 100, which is one embodiment of the present invention. The display device 100 has a display unit in which a plurality of pixels 110 are arranged in a matrix, and a connection unit 140 outside the display unit. Each pixel 110 has a plurality of subpixels. Figure 1A shows a 2x2 arrangement of pixels 110. Furthermore, assuming that each pixel 110 has three subpixels (subpixel 110a, subpixel 110b, and subpixel 110c), it shows a 2x6 arrangement of subpixels. The connection unit 140 can also be called a cathode contact unit.

[0047] Each sub-pixel has a light-emitting device. The planar shape of the sub-pixel shown in Figure 1A (hereinafter also referred to as the top surface shape) corresponds to the top surface shape of the light-emitting area of ​​the light-emitting device. The top surface shape of the sub-pixel can be, for example, a polygon such as a triangle, quadrilateral (including rectangles and squares), or pentagon, or a polygon with rounded corners, or an ellipse or a circle.

[0048] Each sub-pixel has a pixel circuit that has the function of controlling the light-emitting device. The pixel circuit is not limited to the sub-pixel range shown in Figure 1A, but may be located outside of it. For example, the transistor in the pixel circuit of sub-pixel 110a may be located within the range of sub-pixel 110b shown in Figure 1A, or some or all of it may be located outside the range of sub-pixel 110a.

[0049] In Figure 1A, the aperture ratios of sub-pixels 110a, 110b, and 110c are shown to be equal (equal in size, or equal in size of light-emitting area), or approximately equal, but one aspect of the present invention is not limited thereto. The aperture ratios of sub-pixels 110a, 110b, and 110c can each be determined as appropriate. The aperture ratios of sub-pixels 110a, 110b, and 110c may be different, or two or more may be equal, or approximately equal.

[0050] A stripe array is applied to pixel 110 shown in Figure 1A. Pixel 110 in Figure 1A is composed of three subpixels: subpixel 110a, subpixel 110b, and subpixel 110c. Subpixels 110a, 110b, and 110c each emit light of a different color. Examples of subpixels 110a, 110b, and 110c include subpixels of three colors: red (R), green (G), and blue (B); and subpixels of three colors: yellow (Y), cyan (C), and magenta (M). Furthermore, the number of subpixel colors is not limited to three; there may be four or more. Examples of four-color 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).

[0051] 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.

[0052] Figure 1A shows an example where the connecting portion 140 is located on one side of the display portion in a top view, but the position of the connecting portion is not particularly limited. The connecting portion 140 only needs to be provided at least one location on the display portion in a top view, and may be provided so as to surround all four sides of the display portion. The top shape of the connecting portion 140 is not particularly limited and can be strip-shaped, L-shaped, U-shaped, or frame-shaped, etc. Also, there may be one or more connecting portions 140.

[0053] Figure 1B shows cross-sectional views between the dashed lines X1-X2 and Y1-Y2 in Figure 1A. Figure 2 shows an enlarged view of a part of the cross-sectional view shown in Figure 1B. Here, we will explain using a configuration in which red light is emitted from sub-pixel 110a, green light is emitted from sub-pixel 110b, and blue light is emitted from sub-pixel 110c as an example.

[0054] The sub-pixel 110a includes a light-emitting device 130a and a colored layer 132R that transmits red light. As a result, the light emitted from the light-emitting device 130a is extracted as red light to the outside of the display device via the colored layer 132R.

[0055] Similarly, the sub-pixel 110b includes a light-emitting device 130b and a colored layer 132G that transmits green light. As a result, the light emitted from the light-emitting device 130b is extracted as green light to the outside of the display device via the colored layer 132G.

[0056] The sub-pixel 110c includes a light-emitting device 130c and a colored layer 132B that transmits blue light. As a result, the light emitted from the light-emitting device 130c is extracted as blue light to the outside of the display device via the colored layer 132B.

[0057] When describing matters common to light-emitting devices 130a, 130b, and 130c, the letters that distinguish them may be omitted, and they may simply be referred to as light-emitting device 130. Similarly, for components distinguished by letters, such as colored layer 132R, colored layer 132G, and colored layer 132B, when describing matters common to them, the letters may be omitted and a code may be used.

[0058] As shown in Figure 1B, the display device 100 has an insulating layer on layer 101, light-emitting devices 130a, 130b, and 130c on the insulating layer, and a protective layer 131 covering these light-emitting devices 130. On the protective layer 131, there are colored layers 132R, 132G, and 132B, and the substrate 120 is bonded to them by a resin layer 122. In addition, an insulating layer 181 is provided between adjacent light-emitting devices 130.

[0059] If subpixels that emit white light are provided, the configuration may involve either providing a colored layer that transmits white light, or omitting the colored layer.

[0060] The layer 101 preferably includes a pixel circuit that has a function to control the light-emitting device 130. The pixel circuit can be configured, for example, to include a transistor, a capacitive element, and wiring. In addition to the pixel circuit, the layer 101 may also have one or both of a gate line driving circuit (gate driver) and a source line driving circuit (source driver). Furthermore, it may also have one or both of an arithmetic circuit and a memory circuit.

[0061] Layer 101 can have a configuration in which pixel circuits are provided on a semiconductor substrate or an insulating substrate. As the semiconductor substrate, a single-crystal semiconductor substrate made of silicon or silicon carbide, a polycrystalline semiconductor substrate, a compound semiconductor substrate such as silicon germanium, or an SOI substrate can be used. As the insulating substrate, a glass substrate, a quartz substrate, a sapphire substrate, a ceramic substrate, or an organic resin substrate can be used. The shape of the semiconductor substrate and the insulating substrate may be circular or rectangular. The semiconductor substrate and the insulating substrate can be substrates that have at least enough heat resistance to withstand subsequent heat treatment.

[0062] Layer 101 can, for example, be a laminated structure consisting of a substrate on which multiple transistors are provided and an insulating layer covering these transistors. The insulating layer on the transistors 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 transistors. These insulating layers may have recesses between adjacent light-emitting devices. Figure 1B and others show an example in which insulating layer 255c has a recess. Note that insulating layer 255c does not have to have a recess between adjacent light-emitting devices. The insulating layers on the transistors (insulating layers 255a to insulating layers 255c) can also be considered as part of layer 101 including the transistors.

[0063] The insulating layers 255a, 255b, and 255c can each suitably use various inorganic insulating films such as oxide insulating films, nitride insulating films, oxidative nitride insulating films, and nitride oxide insulating films. 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. For insulating layer 255b, it is preferable to use nitride insulating films or nitride oxide insulating films such as silicon nitride films and silicon nitride oxide films. More specifically, it is preferable to use silicon oxide films for insulating layers 255a and 255c, and silicon nitride films for insulating layer 255b. It is preferable that insulating layer 255b functions as an etching protective film.

[0064] In this specification, "oxide nitride" refers to a material in which the oxygen content is greater than the nitrogen content, and "nitride oxide" refers to a material in which the nitrogen content is greater than the oxygen content. For example, when "silicon oxynitride" is written, it refers to a material in which the oxygen content is greater than the nitrogen content, and when "silicon nitride oxide" is written, it refers to a material in which the nitrogen content is greater than the oxygen content.

[0065] The light-emitting device 130 is preferably an OLED (Organic Light Emitting Diode) or a QLED (Quantum-dot Light Emitting Diode). Examples of light-emitting materials for the light-emitting device 130 include fluorescent materials, phosphorescent materials, and thermally activated delayed fluorescence (TADF) materials. Not only organic compounds but also inorganic compounds (such as quantum dot materials) can be used as the light-emitting material for the EL element. Furthermore, LEDs such as microLEDs (Light Emitting Diodes) can also be used as the light-emitting device 130.

[0066] The light-emitting color of the light-emitting device 130 can be 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 130.

[0067] 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.

[0068] Of the pair of electrodes in the light-emitting device 130, the electrode that extracts light can use a conductive film that transmits visible light, while the electrode that does not extract light can use a conductive film that reflects visible light. Alternatively, a conductive film that transmits visible light may also be used for the electrode that does not extract light. In this case, it is preferable to place a conductive film that transmits visible light between the conductive film that reflects visible light and the EL layer.

[0069] Of the pair of electrodes in the light-emitting device 130, one electrode functions as the anode and the other electrode functions as the cathode. In the following explanation, we may use the case where the pixel electrode functions as the anode and the common electrode functions as the cathode as an example.

[0070] Light-emitting device 130a has a pixel electrode 111a on an insulating layer 255c, an island-shaped EL layer 113 on the pixel electrode 111a, and a common electrode 115 on the EL layer 113. Light-emitting device 130b has 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. Light-emitting device 130c has a pixel electrode 111c on an insulating layer 255c, an EL layer 113 on the pixel electrode 111c, and a common electrode 115 on the EL layer 113.

[0071] One embodiment of the present invention is a display device having an EL layer 113 provided in an island-like manner for each light-emitting device 130. Specifically, light-emitting devices 130a, 130b, and 130c each have an EL layer 113, and each EL layer 113 is separated and does not have areas in contact with each other. By providing the EL layer 113 in an island-like manner for each light-emitting device 130, leakage current between adjacent light-emitting devices 130 can be suppressed. This prevents crosstalk caused by unintended light emission, 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.

[0072] Each EL layer 113 can be formed using the same material and the same process. Since the EL layers 113 have the same configuration in light-emitting devices 130a, 130b, and 130c, the manufacturing process for the display device can be reduced, leading to lower manufacturing costs and improved manufacturing yield.

[0073] As shown in Figure 2, the insulating layer 181 provided between adjacent light-emitting devices 130 has regions that are in contact with the sides of the pixel electrodes 111a, 111b, and 111c, and the upper surface of the insulating layer 255c. By covering the sides of the pixel electrodes 111a, 111b, and 111c with the insulating layer 181, contact between the pixel electrodes 111a, 111b, and 111c and the common electrode 115 can be suppressed, thereby suppressing short circuits in the light-emitting devices 130. This improves the reliability of the light-emitting devices 130. In addition, by covering the sides of the pixel electrodes 111a, 111b, and 111c with the insulating layer 181, the diffusion of impurities (typically water and oxygen) into the light-emitting devices 130 via the pixel electrodes 111a, 111b, and 111c can be suppressed.

[0074] In Figure 1B, multiple cross-sections of the insulating layer 181 are shown, but in a top view, the insulating layer 181 is connected as one. In other words, the display device 100 can be configured to have, for example, one insulating layer 181. However, the display device 100 may have multiple insulating layers 181 that are separated from each other.

[0075] The upper surface of the insulating layer 181 is at the same height as, or approximately at the same height as, the upper surfaces of the pixel electrodes 111a, 111b, and 111c. The EL layer 113 is provided covering the upper surfaces of the pixel electrodes 111a, 111b, and 111c, as well as the upper surface of the insulating layer 181. The insulating layer 181 also has an opening 187. As shown in Figures 1B and 2, the opening 187 may be concave in cross-sectional view. As shown in Figure 4B, a layer other than the insulating layer 181 (for example, insulating layer 255b) may be exposed at the opening 187. At the opening 187, the EL layer 113 may have a region in contact with the side surface of the insulating layer 181.

[0076] A display device according to one aspect of the present invention has areas on the upper surfaces of the pixel electrodes 111a, 111b, and 111c, which are the surfaces on which the EL layer 113 is formed, and on the upper and side surfaces of the insulating layer 181, where the EL layer 113 is not formed. These areas can be called stepped areas. Figure 2 shows a configuration in which areas (stepped areas) on which the EL layer 113 is not formed are provided on a part of the side surface and a part of the upper surface of the insulating layer 181. When the EL layer 113 is formed, the surface on which the EL layer 113 is formed has a step created by the opening 187. This step reduces the coverage of the EL layer 113, making it possible to provide stepped areas of the EL layer 113.

[0077] The shape of the insulating layer 181 will be explained using the region between the pixel electrode 111b and the pixel electrode 111c shown in Figure 2 as an example. Between the pixel electrode 111b and the pixel electrode 111c, the insulating layer 181 has a first surface in contact with the side surface of the pixel electrode 111b, a second surface facing the first surface, and a third surface in contact with the lower surface of the EL layer 113 on the pixel electrode 111b. The insulating layer 181 also has a fourth surface in contact with the side surface of the pixel electrode 111c, a fifth surface facing the fourth surface, and a sixth surface in contact with the lower surface of the EL layer 113 on the pixel electrode 111c. In one embodiment of the present invention, the display device has a region in which the height of the third surface, the height of the sixth surface, the height of the upper surface of the pixel electrode 111b, and the height of the upper surface of the pixel electrode 111c coincide or substantially coincide with each other. Here, we have described the insulating layer 181 located between pixel electrode 111b and pixel electrode 111c, but the same applies to insulating layers 181 located between other pixel electrodes 111. For example, the insulating layer 181 located between pixel electrode 111a and pixel electrode 111b can also be described by referring to the above description.

[0078] Note that the second and fifth surfaces may sometimes be referred to as the sides of the opening 187.

[0079] At the top of the opening 187, the angle θ1 formed by the side surface of the opening 187 and the top surface of the insulating layer 181 is preferably vertical or approximately vertical. The angle θ1 can also be said to be the angle formed by the side surface and the top surface of the insulating layer 181 at the top of the opening 187. If the value of angle θ1 is large, the coverage when forming the EL layer 113 will increase, and there is a risk that a stepped region of the EL layer 113 will not be provided. On the other hand, if the angle θ1 is small, the width of the insulating layer 181 in the region overlapping with the side surfaces of the pixel electrodes 111a, 111b, and 111c will be narrowed, and there is a risk that the side surfaces of the pixel electrodes 111a, 111b, and 111c will be exposed. The angle θ1 is preferably 80° or more and 110° or less, more preferably 80° or more and 100° or less, more preferably 85° or more and 100° or less, and more preferably 85° or more and 95° or less. By setting the angle θ1 to the aforementioned range, a stepped region of the EL layer 113 can be created, while simultaneously preventing the exposure of the sides of the pixel electrodes 111a, 111b, and 111c. The angle θ1 can also be described as the angle between the second and third surfaces, or the angle between the fifth and sixth surfaces. Figure 2, etc., shows the angle θ1 between the second and third surfaces as a representative example.

[0080] At the bottom of the opening 187, the angle θ2 formed by the side surface of the opening 187 and the upper surface of the insulating layer 181 is preferably vertical or approximately vertical. The angle θ2 can also be said to be the angle formed by the side surface and the upper surface of the insulating layer 181 at the bottom of the opening 187. If the angle θ2 is large, the coverage when forming the EL layer 113 will increase, and there is a risk that a stepped region of the EL layer 113 will not be provided. On the other hand, if the angle θ2 is small, the width of the insulating layer 181 in the region overlapping with the side surfaces of the pixel electrodes 111a, 111b, and 111c will be narrowed, and there is a risk that the side surfaces of the pixel electrodes 111a, 111b, and 111c will be exposed. The angle θ2 is preferably 80° or more and 110° or less, more preferably 80° or more and 100° or less, more preferably 85° or more and 100° or less, and more preferably 85° or more and 95° or less. By setting the angle θ2 to the aforementioned range, it is possible to create a stepped region in the EL layer 113 while suppressing the exposure of the sides of the pixel electrodes 111a, 111b, and 111c.

[0081] While angle θ1 is preferably within the range described above, as shown in Figure 3A, the corner of the upper end of the insulating layer 181 may be rounded. If the corner of the upper end of the insulating layer 181 is rounded, angle θ1 can be defined, for example, as shown in Figure 3B, by a tangent line in contact with the upper surface of the insulating layer 181 and a tangent line in contact with the side surface of the insulating layer 181 that does not contact the pixel electrode 111. Similarly, angle θ2 can be defined by a tangent line in contact with the upper surface of the insulating layer 181 and a tangent line in contact with the side surface of the insulating layer 181 that does not contact the insulating layer 255c.

[0082] An organic layer 119 may be provided within the opening 187. The organic layer 119 is formed when the material for the EL layer 113 reaches the opening 187 during the formation of the EL layer 113. In other words, the organic layer 119 is formed using the same material and process as the EL layer 113. Figure 2 shows an example in which the organic layer 119 is provided on the insulating layer 181 at the bottom of the opening 187. The bottom of the opening 187 may be covered with the organic layer 119, or the insulating layer 181 may be exposed.

[0083] It is preferable that the organic layer 119 does not have a region in contact with the EL layer 113. If the organic layer 119 has a region in contact with the EL layer 113, the EL layers 113 of adjacent light-emitting devices 130 may connect via the organic layer 119, potentially causing leakage current. It is also preferable that the organic layer 119 does not have a region in contact with the side surface of the insulating layer 181. If the organic layer 119 has a region in contact with the side surface of the insulating layer 181, the EL layers 113 of adjacent light-emitting devices 130 may connect via the organic layer 119. In the opening 187, it is preferable that the insulating layer 181 has a region that does not come into contact with either the EL layer 113 or the organic layer 119.

[0084] Here, we will explain the materials that can be used for the insulating layer 181.

[0085] The insulating layer 181 can be made of an inorganic material. For example, the insulating layer 181 can be made of one or more oxides, nitrides, oxidized nitrides, or nitride oxides. The insulating layer 181 may be a single layer or a multilayer structure. Examples of oxides include silicon oxide, aluminum oxide, magnesium oxide, indium gallium zinc oxide, gallium oxide, germanium oxide, yttrium oxide, zirconium oxide, lanthanum oxide, neodymium oxide, hafnium oxide, and tantalum oxide. Examples of nitrides include silicon nitride and aluminum nitride. Examples of oxidized nitrides include silicon oxidized nitride and aluminum oxidized nitride. Examples of nitride oxides include silicon oxide nitride and aluminum oxide nitride. In particular, by applying aluminum oxide, hafnium oxide, or silicon oxide formed by atomic layer deposition (ALD) to the insulating layer 181, an insulating layer 181 can be formed that has fewer pinholes and excellent protection for the pixel electrodes 111. Furthermore, the insulating layer 181 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 181 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.

[0086] Preferably, the insulating layer 181 functions as a barrier insulating layer against at least one of water and oxygen. Furthermore, preferably, the insulating layer 181 has the function of suppressing the diffusion of at least one of water and oxygen. Also, preferably, the insulating layer 181 has the function of capturing or fixing (also known as gettering) at least one of water and oxygen.

[0087] 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).

[0088] The insulating layer 181 functions as a barrier insulating layer or has a gettering function, which makes it possible to suppress the intrusion of impurities (typically water and oxygen) that can diffuse from the outside into each light-emitting device. By suppressing the intrusion of impurities, for example, oxidation of the pixel electrode 111 and an increase in resistance can be suppressed. Furthermore, the diffusion of impurities into the EL layer 113 via the pixel electrode 111 can be suppressed. Therefore, a highly reliable light-emitting device and, furthermore, a highly reliable display device can be made.

[0089] It is preferable that the insulating layer 181 has a low impurity concentration. This suppresses the diffusion of impurities from the insulating layer 181 to the EL layer 113 via the pixel electrode 111, thereby preventing the degradation of the EL layer 113. Furthermore, by lowering the impurity concentration of the insulating layer 181, the barrier properties of the insulating layer 181 against at least one of water and oxygen can be improved. For example, it is desirable that the insulating layer 181 has sufficiently low hydrogen concentration and carbon concentration, preferably both.

[0090] Furthermore, the insulating layer 181 can be made of the same material that can be used for the insulating layer 255c. For example, the same material can be used for both the insulating layer 181 and the insulating layer 255c. In this case, the boundary between the insulating layer 181 and the insulating layer 255c may become unclear and indistinguishable, and they may be perceived as a single layer.

[0091] In the region of the opening 187 where neither the EL layer 113 nor the organic layer 119 is provided, a void 183 may be provided. The void 183 may contain one or more of the following: air, nitrogen, oxygen, carbon dioxide, and Group 18 elements (typically helium, neon, argon, xenon, krypton, etc.). The void 183 may contain, for example, a gas used for forming the common electrode 115. For example, when forming the common electrode 115 by sputtering using argon, the void 183 may contain argon. If the void 183 contains a gas, the gas can be identified, for example, by gas chromatography. The upper end of the region where the void 183 is provided may be at a higher position than the opening 187.

[0092] If the depth T1 of the opening 187 is shallow, the step difference on the surface of the EL layer 113 will be small, and the EL layers 113 of adjacent light-emitting devices 130 may become connected. On the other hand, if the depth T2 of the opening 187 is deep, it may take time to form the opening 187, resulting in low productivity. The ratio of the depth T1 of the opening 187 to the film thickness T2 of the EL layer 113 (T1 / T2) is preferably 0.5 to 10.0, more preferably 0.5 to 5.0, more preferably 0.5 to 3.0, more preferably 0.8 to 3.0, more preferably 1.0 to 3.0, more preferably 1.5 to 3.0, and more preferably 1.5 to 2.0. By setting the ratio (T1 / T2) of the depth T1 of the opening 187 to the film thickness T2 of the EL layer 113 within the aforementioned range, a display device having island-shaped EL layers 113 can be manufactured with high productivity. The depth T1 of the opening 187 refers to the difference between the highest and lowest upper surfaces of the insulating layer 181 in a cross-sectional view. The film thickness T2 of the EL layer 113 refers to the difference between the upper and lower surfaces of the EL layer 113 in the region overlapping with the pixel electrode 111 in a cross-sectional view.

[0093] If the width W1 of the aperture 187 is narrow, the organic layer 119 and the EL layer 113 may come into contact, and the EL layers 113 of adjacent light-emitting devices 130 may connect via the organic layer 119. On the other hand, if the width W1 of the aperture 187 is wide, the distance between the light-emitting devices 130 increases, which may reduce the resolution and aperture ratio of the display device. Furthermore, a wide aperture 187 width W1 can suppress connection failures due to stepped cuts in the common electrode 115, or local thinning of the common electrode 115, which can increase electrical resistance. The width W1 of the aperture 187 is preferably 50 nm to 500 nm, more preferably 50 nm to 400 nm, more preferably 100 nm to 400 nm, more preferably 100 nm to 300 nm, more preferably 150 nm to 300 nm, and more preferably 150 nm to 250 nm. The width W1 of the opening 187 refers to the shortest distance between the sides of opposing insulating layers 181 within the opening 187 in a cross-sectional view.

[0094] As shown in Figure 2, etc., the edges of the EL layer 113 may be located in a region that overlaps with the opening 187. In other words, the distance W2 between the edges of adjacent EL layers 113 may be smaller than the width W1 of the opening 187. It is preferable that the film thickness T3 of the common electrode 115 is greater than the distance W2. Note that the distance W2 between the edges of the EL layers 113 refers to the distance between the outermost edge of one EL layer 113 and the outermost edge of an adjacent EL layer 113. Also, the film thickness T3 of the common electrode 115 refers to the difference between the position of the upper surface and the position of the lower surface of the common electrode 115 in a cross-sectional view in a region that overlaps with the pixel electrode 111. Note that the edges of the EL layer 113 may be located on the insulating layer 181 above the opening 187. Also, the edges of the EL layer 113 may be located on the pixel electrode 111. In other words, the distance W2 between the edges of adjacent EL layers 113 may be equal to or greater than the width W1 of the opening 187.

[0095] The aforementioned angles θ1, θ2, depth T1, film thickness T2, film thickness T3, width W1, and distance W2 can each be measured, for example, by scanning electron microscope (SEM), transmission electron microscope (TEM), or scanning transmission electron microscope (STEM) images of the cross-section of the light-emitting device 130.

[0096] Figure 1B and others show examples where the ends of the pixel electrode 111a, pixel electrode 111b, pixel electrode 111c, and conductive layer 123 are perpendicular or approximately perpendicular, but the present invention is not limited to this. The ends of the pixel electrode 111a, pixel electrode 111b, pixel electrode 111c, and conductive layer 123 may each have a tapered shape. Specifically, the ends of the pixel electrode 111a, pixel electrode 111b, pixel electrode 111c, and conductive layer 123 may each have a tapered shape.

[0097] As shown in Figure 1B and other figures, in one embodiment of the present invention, a display device is not provided between the pixel electrode 111 and the EL layer 113, and the insulating layer covering the upper edge of the pixel electrode 111 is not provided. Therefore, the spacing between adjacent light-emitting devices 130 can be made extremely narrow. Consequently, a high-definition or high-resolution display device can be made. In addition, a mask for forming the insulating layer is not required, and the manufacturing cost of the display device can be reduced.

[0098] By omitting an insulating layer covering the upper edge of the pixel electrode 111 between the pixel electrode 111 and the EL layer 113, in other words, by omitting an insulating layer between the pixel electrode 111 and the EL layer 113, the light emitted from the EL layer 113 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.

[0099] The light-emitting device 130 may be a single structure (a structure having only one light-emitting unit) or a tandem structure (a structure having multiple light-emitting units). Each light-emitting unit has at least one light-emitting layer.

[0100] The EL layer 113 has at least an emissive layer. The EL layer 113 may also 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.

[0101] For example, the EL layer 113 may have a light-emitting material that emits blue light and a light-emitting material that emits visible light with a longer wavelength than blue. For example, the EL layer 113 may have a configuration having a light-emitting material that emits blue light and a light-emitting material that emits yellow light, or a configuration having a light-emitting material that emits blue light, a light-emitting material that emits green light, and a light-emitting material that emits red light.

[0102] Light-emitting devices 130a, 130b, and 130c can be, for example, single-structure light-emitting devices having two light-emitting layers, one emitting yellow (Y) light and one emitting blue (B) light, or single-structure light-emitting devices having three light-emitting layers, one emitting red (R) light, one emitting green (G) light, and one emitting blue light. For example, the number of layers and the order of colors of the light-emitting layers can be a three-layer structure of R, G, B from the anode side, or a three-layer structure of R, B, G. In addition, other layers (also called buffer layers) may be provided between the two light-emitting layers.

[0103] When using a tandem-structured light-emitting device 130, a two-stage tandem structure having a light-emitting unit that emits yellow light and a light-emitting unit that emits blue light, a two-stage tandem structure having a light-emitting unit that emits red and green light and a light-emitting unit that emits blue light, or a three-stage tandem structure having a light-emitting unit that emits blue light, a light-emitting unit that emits yellow, yellow-green, or green light and red light, and a light-emitting unit that emits blue light in that order can be applied. For example, as the number of layers and the order of colors of the light-emitting units, from the anode side, examples include a two-stage structure of B, Y, a two-stage structure of B, X, and a three-stage structure of B, X, B. The number of layers and the order of colors of the light-emitting layers in the light-emitting unit X can be a two-layer structure of R, Y, a two-layer structure of R, G, a two-layer structure of G, R, G, a three-layer structure of G, R, G, or a three-layer structure of R, G, R, etc. from the anode side. In addition, other layers may be provided between the two light-emitting layers.

[0104] When using a tandem-structured light-emitting device 130, the EL layer 113 has multiple light-emitting units. It is preferable to provide a charge generation layer between each light-emitting unit.

[0105] The light-emitting unit has at least one light-emitting layer. For example, if the light emitted by multiple light-emitting units is complementary in color, the light-emitting device 130 can emit white light. The light-emitting unit may also have one or more of the following: a hole injection layer, a hole transport layer, a hole blocking layer, an electron blocking layer, an electron transport layer, and an electron injection layer.

[0106] Furthermore, by applying a microcavity structure, the light-emitting device 130, which is configured to emit white light, may also emit light of specific wavelengths such as red, green, blue, or infrared light with enhanced intensity.

[0107] For example, the EL layer 113 may have a hole injection layer, a hole transport layer, an emissive layer, and an electron transport layer in this order. 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. Additionally, an electron injection layer may be present on the electron transport layer.

[0108] For example, the EL layer 113 may have an electron injection layer, an electron transport layer, an emissive layer, and a hole transport layer in this order. Alternatively, a hole blocking layer may be present between the electron transport layer and the emissive layer. Furthermore, an electron blocking layer may be present between the hole transport layer and the emissive layer. Additionally, a hole injection layer may be present on the hole transport layer.

[0109] Thus, it is preferable that the EL layer 113 has an emissive layer and a carrier transport layer (electron transport layer or hole transport layer) on the emissive layer. It is also preferable that the EL layer 113 has an emissive layer and a carrier block layer (hole block layer or electron block layer) on the emissive layer. Furthermore, it is preferable that the EL layer 113 has an emissive layer, a carrier block layer on the emissive layer and a carrier transport layer on the carrier block layer. Since the surface of the EL layer 113 is exposed during the manufacturing process of the display device, by providing one or both of the carrier transport layer and the carrier block layer on the emissive layer, it is possible to suppress the exposure of the emissive layer to the outermost surface and reduce the damage to the emissive layer. This can improve the reliability of the light-emitting device.

[0110] The heat resistance temperature of the compounds contained in the EL layer 113 is preferably 100°C to 180°C, preferably 120°C to 180°C, and more preferably 140°C to 180°C. For example, the glass transition temperature (Tg) of these compounds is preferably 100°C to 180°C, preferably 120°C to 180°C, and more preferably 140°C to 180°C.

[0111] In particular, it is preferable that the heat resistance temperature of the functional layer provided on the light-emitting layer is high. Furthermore, it is even more preferable that the heat resistance temperature of the functional layer provided in contact with the light-emitting layer is high. The high heat resistance of the functional layer makes it possible to effectively protect the light-emitting layer and reduce the damage it receives.

[0112] It is preferable that the heat resistance temperature of the light-emitting layer be high. This helps to prevent damage to the light-emitting layer due to heating, which can reduce luminous efficiency and shorten its lifespan.

[0113] The light-emitting layer comprises a light-emitting substance (also called a light-emitting organic compound or guest material) and an organic compound (also called a host material). Since the light-emitting layer contains a larger amount of the organic compound than the light-emitting substance, the Tg of the organic compound can be used as an indicator of the heat resistance temperature of the light-emitting layer.

[0114] The EL layer 113 includes, for example, a first light-emitting unit, a charge generation layer, and a second light-emitting unit.

[0115] The second light-emitting unit preferably comprises a light-emitting layer and a carrier transport layer (electron transport layer or hole transport layer) on the light-emitting layer. Furthermore, the second light-emitting unit preferably comprises a light-emitting layer and a carrier block layer (hole block layer or electron block layer) on the light-emitting layer. Furthermore, the second light-emitting unit preferably comprises a light-emitting layer, a carrier block layer on the light-emitting layer, and a carrier transport layer on the carrier block layer. Since the surface of the second light-emitting unit is exposed during the manufacturing process of the display device, providing one or both of the carrier transport layer and the carrier block layer on the light-emitting layer suppresses exposure of the light-emitting layer to the outermost surface, thereby reducing damage to the light-emitting layer. This improves the reliability of the light-emitting device. If there are three or more light-emitting units, it is preferable that the uppermost light-emitting unit comprises a light-emitting layer and one or both of the carrier transport layer and the carrier block layer on the light-emitting layer.

[0116] Figure 1B shows an example where the edge of the EL layer 113 is located outside the edge of the pixel electrode 111. With this configuration, it becomes possible to make the entire upper surface of the pixel electrode 111 an emitting region, and it becomes easier to increase the aperture ratio compared to a configuration where the edges of the island-shaped EL layer 113 are located inside the edges of the pixel electrode 111.

[0117] The common electrode 115 is provided on the EL layer 113. The common electrode 115 is shared by the light-emitting devices 130a, 130b, and 130c. The common electrode 115, which is shared by multiple light-emitting devices 130, is electrically connected to the conductive layer 123 provided at the connection portion 140 (see Figure 1B). It is preferable that the conductive layer 123 is a conductive layer formed using the same material and process as the pixel electrodes 111a, 111b, and 111c.

[0118] It is preferable to provide a protective layer 131 on the light-emitting devices 130a, 130b, and 130c. Providing the protective layer 131 can improve the reliability of the light-emitting devices 130. The protective layer 131 may be a single layer or a laminated structure of two or more layers.

[0119] 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.

[0120] The presence of an inorganic film in the protective layer 131 prevents oxidation of the common electrode 115, suppresses the intrusion of impurities (such as moisture and oxygen) into the light-emitting device, thereby suppressing degradation of the light-emitting device and improving the reliability of the display device.

[0121] The protective layer 131 can be, for example, an inorganic film having an oxide, nitride, oxidized nitride, or nitride oxide. Specific examples of these are given in the description of the insulating layer 181. In particular, the protective layer 131 preferably has a nitride insulator or nitride oxide, and more preferably a nitride.

[0122] 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.

[0123] 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.

[0124] The protective layer 131 can be, 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. By using such a laminated structure, the diffusion of impurities (water, oxygen, etc.) to the EL layer 113 can be suppressed.

[0125] Furthermore, the protective layer 131 may have an organic film. Examples of organic materials that can be used for the protective layer 131 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. The protective layer 131 may have both an organic film and an inorganic film. For example, the protective layer 131 may have a laminated structure of an organic film and an inorganic film.

[0126] The protective layer 131 may be a laminated structure formed using different film deposition methods. Specifically, it can be a laminated structure consisting of a first layer formed using the ALD method and a second layer formed on the first layer using the sputtering method.

[0127] A light-shielding layer may be provided on the surface of the substrate 120 facing the resin layer 122. Various optical components can also be placed on the outside of the substrate 120. Examples of optical components include polarizing plates, phase difference plates, light diffusion layers (such as diffusion films), anti-reflective layers, and light-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. x By providing a protective layer, surface contamination and scratching can be suppressed, which is preferable. The surface protective layer may be made of DLC (diamond-like carbon) or 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.

[0128] 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.

[0129] The substrate 120 can be made of 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.

[0130] 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).

[0131] 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.

[0132] 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.

[0133] When a film is used as a substrate, the film may absorb water, which could cause changes in the shape of the display device, such as wrinkles. 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.

[0134] The resin layer 122 can be made of various types of curing adhesives, such as UV-curing adhesives, reaction-curing adhesives, thermosetting adhesives, or anaerobic adhesives. Examples of these adhesives include epoxy resins, acrylic resins, silicone resins, phenolic resins, polyimide resins, imide resins, PVC (polyvinyl chloride) resins, PVB (polyvinyl butyral) resins, 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.

[0135] Figure 1B shows an example in which colored layers 132R, 132G, and 132B are directly provided on the light-emitting devices 130a, 130b, and 130c via a protective layer 131. This configuration improves the accuracy of the alignment between the light-emitting devices and the colored layers. Furthermore, bringing the light-emitting devices and colored layers closer together suppresses color mixing and improves viewing angle characteristics, which is preferable.

[0136] The following describes an example configuration different from the display device described above. Note that parts that overlap with the display device described above may be omitted from the explanation. Also, in the drawings shown below, parts having the same function as the display device described above may use the same hatching pattern and may not be labeled.

[0137] <Configuration Example 2> Figure 4A shows a cross-sectional view of a display device according to one aspect of the present invention. A top view can be found in Figure 1A. Figure 4B shows an enlarged view of a part of the cross-sectional view shown in Figure 4A.

[0138] The display device shown in Figure 4A, etc., differs from the display device shown in <Configuration Example 1> in that the opening 187 is provided in the insulating layer 181 and the insulating layer 255c.

[0139] Figure 4A, etc., shows an example where the opening 187 reaches the insulating layer 255b. At the bottom of the opening 187, the organic layer 119 is provided on the insulating layer 255b. The bottom of the opening 187 may be covered by the organic layer 119, or the insulating layer 255b may be exposed.

[0140] The opening 187 may also be provided in the insulating layer 181, the insulating layer 255c, and the insulating layer 255b.

[0141] <Configuration Example 3> Figure 5A shows a cross-sectional view of a display device according to one aspect of the present invention. A top view can be found in Figure 1A. Figure 5B shows an enlarged view of a part of the cross-sectional view shown in Figure 5A.

[0142] The display device shown in Figure 5A, etc., differs from the display device shown in <Configuration Example 1> in that it has conductive layers 116a, 116b, and 116c.

[0143] The display device shown in Figure 5A, etc., employs a microcavity structure. One of the pair of electrodes in the light-emitting device 130 is a semi-transmitting / semi-reflective electrode that transmits and reflects visible light, while the other is a reflective electrode that reflects visible light. By applying a microcavity structure to the light-emitting device 130, the light obtained from the light-emitting layer is resonated between the two electrodes, thereby intensifying the light emitted from the light-emitting device 130. Furthermore, since the emission intensity of light of a specific wavelength can be increased, color purity can be improved. Even with the same EL layer 113 configuration, light of different wavelengths (monochromatic light) can be extracted. In addition, since the emission intensity in the front direction of a specific wavelength can be increased, power consumption can be reduced. Moreover, by combining the microcavity structure with a colored layer, color purity can be further improved.

[0144] The light-emitting device 130a has a conductive layer 116a between the pixel electrode 111a and the EL layer 113. The light-emitting device 130b has a conductive layer 116b between the pixel electrode 111b and the EL layer 113. The light-emitting device 130c has a conductive layer 116c between the pixel electrode 111c and the EL layer 113. The conductive layers 116a, 116b, and 116c each function as optical adjustment layers in the light-emitting device 130. Optical adjustment can be performed by controlling the film thickness of the optical adjustment layers. Specifically, it is preferable to adjust the distance between the pixel electrode 111 and the common electrode 115 to be mλ / 2 (where m is an integer of 1 or more) or near that value, with respect to the wavelength λ of the light obtained from the light-emitting layer.

[0145] In one aspect of the present invention, the display device has EL layers 113 of light-emitting devices 130a, 130b, and 130c formed using the same material and the same process, so the film thickness of each EL layer 113 is the same or approximately the same. Therefore, in order to make the distance between the pixel electrode 111 and the common electrode 115 different, the film thicknesses of the conductive layers 116a, 116b, and 116c sandwiched between the pixel electrode 111 and the common electrode 115 can be made different from each other.

[0146] Here, we will explain using the example of the case where the aforementioned m is common to light-emitting devices 130a, 130b, and 130c. For light-emitting devices 130 that have a region superimposed with a colored layer 132 that transmits long wavelength light, the thickness of the conductive layer 116 should be increased, and for light-emitting devices 130 that have a region superimposed with a colored layer 132 that transmits short wavelength light, the thickness of the conductive layer 116 should be decreased. For example, if the colored layer 132R transmits red light, the colored layer 132G transmits green light, and the colored layer 132B transmits blue light, then, as shown in Figure 5A, the thicknesses of the conductive layers 116a, 116b, and 116c should be decreased in this order.

[0147] The conductive layers 116a, 116b, and 116c provided on the pixel electrode 111 can each be said to have a function as a pixel electrode.

[0148] The conductive layer 123 provided in the connection portion 140 is electrically connected to the common electrode 115 via the conductive layer 116p. The conductive layer 116p can be formed in the same process as, for example, conductive layer 116a, conductive layer 116b, or conductive layer 116c. For example, the conductive layer 116p can be formed in the same process as conductive layer 116c, and as shown in Figure 5A, the thickness of the conductive layer 116p can be equal to or approximately equal to the thickness of the conductive layer 116c. Alternatively, the conductive layer 116p may be omitted in the connection portion 140, and the conductive layer 123 and the common electrode 115 may be in direct contact and electrically connected.

[0149] The side surface of conductive layer 116a is aligned with, or approximately aligned with, the side surface of opening 187. The side surface of conductive layer 116b is aligned with, or approximately aligned with, the side surface of opening 187. The side surface of conductive layer 116c is aligned with, or approximately aligned with, the side surface of opening 187. Also, the side surface of conductive layer 116p is aligned with, or approximately aligned with, the side surface of opening 187. Because the side surfaces of conductive layers 116a, 116b, and 116c are aligned with the side surface of opening 187, the step height of the formed surface of EL layer 113 is the depth T1 of opening 187 plus the thickness of conductive layer 116. Therefore, the step height of the formed surface of EL layer 113 is increased, making it easier to form island-shaped EL layers 113. For example, in Figure 5B, the step height of the surface of the EL layer 113 formed on the conductive layer 116b is the depth T1 of the opening 187 plus the thickness of the conductive layer 116b. The step height of the surface of the EL layer 113 formed on the conductive layer 116c is the depth T1 of the opening 187 plus the thickness of the conductive layer 116c.

[0150] When the side surface of the conductive layer 116a and the side surface of the opening 187 are aligned or roughly aligned, and the top surface shapes match or roughly match, it can be said that at least a portion of the contours of the conductive layer 116a and the opening 187 overlap when viewed from above. However, strictly speaking, the contours may not overlap, and the contour of the conductive layer 116a may be located inside the contour of the opening 187, or the contour of the conductive layer 116a may be located outside the contour of the opening 187. In this case as well, the side surfaces are said to be roughly aligned, or the top surface shapes roughly match.

[0151] When the side surface of the conductive layer 116a is aligned with, or approximately aligned with, the side surface of the aperture 187, it can also be said that the side surface of the insulating layer 181 that does not contact the pixel electrode 111a (the side facing the aperture 187) coincides with, or approximately coincides with, the side surface of the conductive layer 116a. The same applies to the conductive layer 116b and the conductive layer 116c. When the side surface of the conductive layer 116p is aligned with, or approximately aligned with, the side surface of the aperture 187, it can also be said that the side surface of the insulating layer 181 that does not contact the conductive layer 123 (the side facing the aperture 187) coincides with, or approximately coincides with, the side surface of the conductive layer 116p.

[0152] For example, the opening 187 can be formed using a mask that forms conductive layer 116a, conductive layer 116b, conductive layer 116c, or conductive layer 116p.

[0153] Furthermore, the side surface of the conductive layer 116a can also be considered the edge of the conductive layer 116a. Similarly, the same applies to the conductive layers 116b, 116c, and 116p.

[0154] The EL layer 113 is provided covering the upper surfaces of the conductive layers 116a, 116b, and 116c. The EL layer 113 may have regions that are in contact with the sides of the conductive layers 116a, 116b, and 116c. Furthermore, the EL layer 113 may have regions that are in contact with the sides of the conductive layers 116a, 116b, and 116c, as well as a portion of the sides of the insulating layer 181. By covering the entire sides of the conductive layers 116a, 116b, and 116c, the common electrode 115 is prevented from coming into contact with the conductive layers 116a, 116b, and 116c, thereby preventing a short circuit between the common electrode 115 and the pixel electrode.

[0155] Figure 5A shows conductive layers 116a, 116b, 116c, and 116p as single-layer structures, but the present invention is not limited to this. Some or all of conductive layers 116a, 116b, 116c, and 116p may be in a laminated structure. Figure 6 shows an example in which conductive layer 116a has a three-layer structure consisting of conductive layer 116aA, conductive layer 116aB, and conductive layer 116aC, conductive layer 116b has a two-layer structure consisting of conductive layer 116bA and conductive layer 116bB, and conductive layers 116c and 116p each have a single-layer structure.

[0156] The angle between the top surface and side surface of the conductive layer 116 is preferably perpendicular or approximately perpendicular. Figure 5B shows the angle θ3b between the top surface and side surface of the conductive layer 116b, and the angle θ3c between the top surface and side surface of the conductive layer 116c. The angles θ3b and θ3c are preferably 80° to 110°, more preferably 80° to 100°, more preferably 85° to 100°, and more preferably 85° to 95°. The same applies to the angle θ3a between the top surface and side surface of the conductive layer 116a. By setting the angle between the top surface and side surface of the conductive layer 116 within the above range, a stepped region of the EL layer 113 can be provided. Note that the angle between the top surface and side surface of the conductive layer 116 may be rounded, and it may not be possible to clearly measure angles θ3a, θ3b, and θ3c.

[0157] <Configuration Example 4> Figure 7A shows a cross-sectional view of a display device according to one aspect of the present invention. A top view can be found in Figure 1A. Figure 7B shows an enlarged view of a part of the cross-sectional view shown in Figure 7A.

[0158] The display device shown in Figure 7A, etc., differs from the display device shown in <Configuration Example 3> in that the sides of the conductive layers 116a, 116b, 116c, and 116p do not coincide with the sides of the opening 187. It can also be said that the sides of the conductive layers 116a, 116b, and 116c do not coincide with the sides of the insulating layer 181 that do not come into contact with the pixel electrodes 111, and the side of the conductive layer 116p does not coincide with the sides of the insulating layer 181 that do not come into contact with the conductive layer 123.

[0159] For example, the opening 187 can be formed using a different mask than the one used to form the conductive layer 116a, conductive layer 116b, conductive layer 116c, or conductive layer 116p.

[0160] Figure 7A and others show an example in which the side surface of conductive layer 116a is located on the pixel electrode 111a, the side surface of conductive layer 116b is located on the pixel electrode 111b, the side surface of conductive layer 116c is located on the pixel electrode 111c, and the side surface of conductive layer 116p is located on the conductive layer 123. The EL layer 113 has a region that contacts a part of the upper surface of the pixel electrodes 111a, 111b, and 111c. The EL layer 113 also has a region that contacts the upper surface of the insulating layer 181. The side surfaces of conductive layers 116a, 116b, 116c, and 116p may be located on the insulating layer 181. Alternatively, the side surfaces of conductive layers 116a, 116b, 116c, and 116p may be located on the pixel electrodes 111a, 111b, and 111c.

[0161] If the sides of conductive layers 116a, 116b, and 116c do not coincide with the sides of the opening 187, the ends of conductive layers 116a, 116b, and 116c may each have a tapered shape, as shown in Figures 8A and 8B. The angles formed by the top surface and side surface of conductive layers 116a, 116b, and 116c may be perpendicular or not perpendicular.

[0162] <Configuration Example 5> Figure 9A shows a cross-sectional view of a display device according to one aspect of the present invention. A top view can be found in Figure 1A. Figure 9B shows an enlarged view of a part of the cross-sectional view shown in Figure 9A.

[0163] The display device shown in Figure 9A, etc., differs from the display device shown in <Configuration Example 3> mainly in that it has a common layer 114.

[0164] The common layer 114 is provided between the EL layer 113 and the common electrode 115. The common layer 114 covers the EL layer 113 and is shared by the light-emitting devices 130a, 130b, and 130c. The common layer 114 has, for example, an electron injection layer or a hole injection layer. Alternatively, the common layer 114 may have an electron transport layer and an electron injection layer laminated together, or a hole transport layer and a hole injection layer laminated together.

[0165] The common layer 114 can be formed by methods such as vapor deposition (including vacuum deposition), transfer, printing, inkjet, and coating.

[0166] Figure 9A, etc., shows an example in which a common layer 114 is provided on the conductive layer 116p, and the conductive layer 123 and the common electrode 115 are electrically connected via the common layer 114 and the conductive layer 116p. Alternatively, at the connection portion 140, the common layer 114 may not be provided on the conductive layer 116p, and the conductive layer 116p and the common electrode 115 may be in direct contact and electrically connected. For example, by using a mask (also called an area mask or rough metal mask, to distinguish it from a fine metal mask) to determine the region in which the common layer 114 is formed, the common layer 114 can be deposited only in the desired region. By using different area masks for forming the common layer 114 and the common electrode 115, the regions in which the common layer 114 and the common electrode 115 are formed can be made different.

[0167] <Configuration Example 6> A cross-sectional view of a display device according to one aspect of the present invention is shown in Figures 10A to 10C and Figure 11. A top view can be found in Figure 1A.

[0168] As shown in Figure 10A, the substrate 120 with the colored layer 132 may be bonded to the protective layer 131 with a resin layer 122. By providing the colored layer 132 on the substrate 120, the processing temperature for the formation of the colored layer 132 can be increased.

[0169] As shown in Figures 10B and 10C, the display device may be provided with a lens array 133. The lens array 133 can be provided in a region that overlaps with the light-emitting device 130.

[0170] Figure 10B shows an example in which a colored layer 132R, a colored layer 132G, and a colored layer 132B are provided on the light-emitting devices 130a, 130b, and 130c via a protective layer 131, an insulating layer 134 is provided on the colored layers 132R, 132G, and 132B, and a lens array 133 is provided on the insulating layer 134. By directly forming the colored layers 132R, 132G, 132B, and the lens array 133 on the substrate on which the light-emitting device 130 is formed, the accuracy of the alignment between the light-emitting device and the colored layer 132 or the lens array 133 can be improved.

[0171] In Figure 10B, the light emitted from the light-emitting device 130 passes through the colored layer 132, then through the lens array 133, and is extracted to the outside of the display device. Bringing the light-emitting device 130 and the colored layer 132 closer together is preferable because it can suppress color mixing and improve viewing angle characteristics. Alternatively, the lens array 133 may be provided on the light-emitting device, and the colored layer 132 may be provided on the lens array 133.

[0172] Figure 10C shows an example in which a substrate 120, on which colored layers 132R, 132G, 132B, and a lens array 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 array 133, the temperature of the heat treatment in the formation process can be increased.

[0173] Figure 10C shows an example in which colored layers 132R, 132G, and 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 array 133 is provided in contact with the insulating layer 134.

[0174] In Figure 10C, the light emitted from the light-emitting device passes through the lens array 133, then through the colored layer, and is extracted to the outside of the display device. Alternatively, the lens array 133 may be provided in contact with the substrate 120, the insulating layer 134 in contact with the lens array 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 array 133, and is extracted to the outside of the display device. As shown in Figures 10B and 10C, it is preferable to provide an overlapping region between the lens array 133 and adjacent lens arrays 133 where the colored layer 132R and the colored layer 132G overlap. By providing an overlapping region of different colored colored layers, color mixing of the light emitted from the light-emitting device can be suppressed.

[0175] Figure 11 shows an example in which a lens array 133 is provided on light-emitting devices 130a, 130b, and 130c via a protective layer 131, and a substrate 120 on which colored layers 132R, 132G, and 132B are provided is bonded to the lens array 133 and the protective layer 131 by a resin layer 122.

[0176] Unlike in Figure 11, the lens array 133 may be provided on the substrate 120, and the colored layer may be formed directly on the protective layer 131. In this way, one of the lens array and the colored layer may be provided on the protective layer 131, and the other on the substrate 120.

[0177] Figures 10A to 10C show an example in which a layer with planarization function is used as the protective layer 131, but as shown in Figure 11, the protective layer 131 does not have to have a planarization function. For example, by using an organic film for the protective layer 131, the upper surface of the protective layer 131 can be made flat. Also, the protective layer 131 shown in Figure 11 can be formed by using, for example, an inorganic film.

[0178] The lens array 133 may have its convex surface facing the substrate 120 side, or it may face the light-emitting device side.

[0179] The lens array 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. Alternatively, a material containing at least one of an oxide and a sulfide can be used for the lens. As the lens array 133, for example, a microlens array can be used. The lens array 133 may be formed directly on a substrate or on a light-emitting device, or a separately formed lens array may be bonded to it.

[0180] In one embodiment of the present invention, the display device has an EL layer 113 arranged in an island shape for each light-emitting device 130, thereby suppressing the generation of leakage current between subpixels. This prevents crosstalk caused by unintended light emission, enabling the realization of a display device with extremely high contrast. Furthermore, the island-shaped EL layer 113 can be formed without using a fine metal mask, resulting in a display device with high resolution and a high aperture ratio. In addition, the productivity of the display device can be increased.

[0181] A method for manufacturing a display device according to one aspect of the present invention will be explained with reference to Figures 12 to 14. Note that explanations of the materials and formation methods of each element may be omitted if they are the same as those described previously.

[0182] Here, we will explain the manufacturing method using the display device shown in Figure 6 as an example. Figures 12 to 14 show side by side the cross-sectional view between the dashed-dotted lines X1 and X2 shown in Figure 1A, and the cross-sectional view between the dashed-dotted lines Y1 and Y2.

[0183] Thin films (insulating films, semiconductor films, and conductive films, etc.) that constitute display devices can be formed using sputtering, chemical vapor deposition (CVD), vacuum deposition, pulsed laser deposition (PLD), atomic layer deposition (ALD), and other methods. CVD methods include plasma-enhanced CVD (PECVD) and thermal CVD. One type of thermal CVD is metal-organic CVD (MOCVD).

[0184] Thin films (insulating films, semiconductor films, conductive films, etc.) that constitute a 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 method, slit coating, roll coating, curtain coating, or knife coating.

[0185] 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.).

[0186] 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. Furthermore, island-shaped thin films may be directly formed by a film deposition method using a shielding mask such as a metal mask.

[0187] 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 forming a photosensitive thin film, then exposing and developing it to process the thin film into the desired shape.

[0188] In photolithography, the light used for exposure can be, for example, i-line (wavelength 365 nm), g-line (wavelength 436 nm), h-line (wavelength 405 nm), or a mixture thereof. Other options include ultraviolet light, KrF laser light, or ArF laser light. Exposure may also be performed using immersion lithography. Furthermore, extreme ultraviolet (EUV) or X-rays may be used as the light for exposure. An electron beam can also be used instead of light for exposure. Using extreme ultraviolet, X-rays, or an electron beam is preferable because it allows for extremely fine processing. Note that a photomask is not required when exposure is performed by scanning a beam such as an electron beam.

[0189] For etching thin films, methods such as dry etching, wet etching, and sandblasting can be used.

[0190] <Example of manufacturing method> First, insulating layers 255a, 255b, and 255c are formed in this order on the layer 101 containing the transistor. Subsequently, pixel electrodes 111a, 111b, 111c, and a conductive layer 123 are formed on the insulating layer 255c (Figure 12A). For the formation of the pixel electrodes, for example, sputtering or vacuum deposition can be used.

[0191] When forming the pixel electrodes 111a, 111b, 111c and the conductive layer 123, a portion of the insulating layer 255c in the region that does not overlap with the pixel electrodes 111a, 111b, 111c and the conductive layer 123 may be removed. In this case, the thickness of the insulating layer 255c in the region that does not overlap with any of the pixel electrodes 111a, 111b, 111c and the conductive layer 123 will be thinner than the thickness of the insulating layer 255c in the region that overlaps with the pixel electrodes 111a, 111b, 111c or the conductive layer 123.

[0192] Next, an insulating film 181f, which will become the insulating layer 181, is formed to cover the pixel electrode 111a, pixel electrode 111b, pixel electrode 111c, conductive layer 123, and insulating layer 255c (Figure 12B).

[0193] Next, a portion of the insulating film 181f is removed to expose the pixel electrode 111a, pixel electrode 111b, pixel electrode 111c, and conductive layer 123, and an insulating layer 181A is formed (Figure 12C). The insulating film 181f can be removed by, for example, dry etching or chemical mechanical polishing (CMP). When using dry etching, suitable etching gases include chlorine-based gases such as chlorine, boron chloride, silicon chloride, or carbon tetrachloride, and fluorine-based gases such as carbon tetrafluoride, sulfur fluoride, or nitrogen fluoride.

[0194] The insulating layer 181A is provided between the pixel electrodes 111a, 111b, 111c, and the conductive layer 123. Preferably, the height of the upper surface of the insulating layer 181A is equal to, or approximately equal to, the height of the upper surfaces of the pixel electrodes 111a, 111b, 111c, and the conductive layer 123. By aligning the heights of the upper surfaces of the insulating layer 181A, 111a, 111b, 111c, and the conductive layer 123, the coverage of the film formed thereafter (in this case, the conductive layer 116) can be improved.

[0195] Next, a conductive film 116fA is formed on the pixel electrode 111a, pixel electrode 111b, pixel electrode 111c, conductive layer 123, and insulating layer 181A, and a resist mask 190A is formed on the conductive film 116fA (Figure 12D). The conductive film 116fA is the film that becomes the conductive layer 116aA, and the resist mask 190A is provided in the region that overlaps with the pixel electrode 111a.

[0196] The resist mask 190A can be formed by applying a photosensitive resin (photoresist), followed by exposure and development. The resist mask 190A may use either a positive-type resist material or a negative-type resist material.

[0197] Next, a portion of the conductive film 116fA is removed using the resist mask 190A as a mask to form the conductive layer 116aA. The resist mask 190A is then removed (Figure 12E).

[0198] Next, a conductive film 116fB is formed on the conductive layer 116aA, pixel electrode 111b, pixel electrode 111c, conductive layer 123, and insulating layer 181A, and a resist mask 190Ba and a resist mask 190Bb are formed on the conductive film 116fB (Figure 13A). The conductive film 116fB is the film that becomes the conductive layer 116aB and the conductive layer 116bA. The resist mask 190Ba is provided in the region that overlaps with the pixel electrode 111a, and the resist mask 190Bb is provided in the region that overlaps with the pixel electrode 111b.

[0199] Next, using resist masks 190Ba and 190Bb as masks, a portion of the conductive film 116fB is removed to form conductive layers 116aB and 116bA. Then, resist masks 190Ba and 190Bb are removed.

[0200] Next, a conductive film 116fC is formed on the conductive layer 116aB, conductive layer 116bA, pixel electrode 111c, conductive layer 123, and insulating layer 181A, and resist masks 190Ca, resist mask 190Cb, resist mask 190Cc, and resist mask 190Cp are formed on the conductive film 116fC (Figure 13B). The conductive film 116fC is the film that forms the conductive layer 116aC, conductive layer 116bB, conductive layer 116c, and conductive layer 116p. The resist mask 190Ca is provided in the region overlapping with the pixel electrode 111a, the resist mask 190Cb is provided in the region overlapping with the pixel electrode 111b, the resist mask 190Cc is provided in the region overlapping with the pixel electrode 111c, and the resist mask 190Cp is provided in the region overlapping with the conductive layer 123.

[0201] Next, a portion of the conductive film 116fC is removed using the resist masks 190Ca, 190Cb, 190Cc, and 190Cp as masks to form conductive layers 116aC, 116bB, 116c, and 116p (Figure 13C). As a result, a conductive layer 116a is formed in the region overlapping with the pixel electrode 111a, with conductive layers 116aA, 116aB, and 116aC stacked in that order. A conductive layer 116b is formed in the region overlapping with the pixel electrode 111b, with conductive layers 116bA and 116bB stacked in that order.

[0202] Next, using the resist masks 190Ca, 190Cb, 190Cc, and 190Cp as masks, a portion of the insulating layer 181A is removed to form an insulating layer 181 having an opening 187 (Figure 14A). The resist masks 190Ca, 190Cb, 190Cc, and 190Cp are then removed.

[0203] The opening 187 can be formed using either a dry etching method or a wet etching method, or both. In forming the opening 187, it is preferable that the angle θ1 between the side surface and the top surface of the insulating layer 181 falls within the aforementioned range. In particular, an anisotropic dry etching method can be suitably used to form the opening 187.

[0204] Here, an example is shown in which the resist masks 190Ca, 190Cb, 190Cc, and 190Cp are used as masks to form the opening 187, but the present invention is not limited to this. After forming the conductive layers 116a, 116b, 116c, and 116p, the resist masks 190Ca, 190Cb, 190Cc, and 190Cp may be removed, and the opening 187 may be formed using a separately formed resist mask. Here, the width (W1) of the opening 187 is preferably within the range described above.

[0205] Next, it is preferable to perform a hydrophobic treatment on the conductive layer 116. The hydrophobic treatment can change the surface to be treated from hydrophilic to hydrophobic, or increase the hydrophobicity of the surface to be treated. By performing the hydrophobic treatment on the conductive layer 116, the adhesion between the conductive layer 116 and the EL layer 113 formed in a later step can be improved, and peeling of the EL layer 113 can be suppressed. However, the hydrophobic treatment is not required.

[0206] Hydrophobic treatment can be carried out, for example, by fluorine modification of the conductive layer 116. Fluorine modification can be carried out, for example, by treatment with a fluorine-containing gas or heat treatment, or by plasma treatment in a fluorine-containing gas atmosphere. As the fluorine-containing gas, for example, fluorine gas can be used, or for example, fluorocarbon gas can be used. As the fluorocarbon gas, for example, lower fluorinated carbon gases such as carbon tetrafluoride (CF4) gas, C4F6 gas, C2F6 gas, C4F8 gas, and C5F8 can be used. In addition, as the fluorine-containing gas, for example, SF6 gas, NF3 gas, CHF3 gas, etc. can be used. Furthermore, helium gas, argon gas, or hydrogen gas, etc. can be added to these gases as appropriate.

[0207] The surface of the conductive layer 116 can be made hydrophobic by performing plasma treatment in a gas atmosphere containing a group 18 element such as argon, followed by treatment with a silylation agent. Hexamethyldisilazane (HMDS), trimethylsilylimidazole (TMSI), etc., can be used as the silylation agent. Furthermore, the surface of the conductive layer 116 can also be made hydrophobic by performing plasma treatment in a gas atmosphere containing a group 18 element such as argon, followed by treatment with a silane coupling agent.

[0208] By performing plasma treatment on the surface of the conductive layer 116 in a gas atmosphere containing a group 18 element such as argon, damage can be inflicted on the surface of the conductive layer 116. This makes it easier for methyl groups contained in silylation agents such as HMDS to bond to the surface of the conductive layer 116. It also makes silane coupling by silane coupling agents easier to occur. Thus, by performing plasma treatment on the surface of the conductive layer 116 in a gas atmosphere containing a group 18 element such as argon, followed by treatment with a silylation agent or a silane coupling agent, the surface of the conductive layer 116 can be made hydrophobic.

[0209] Treatment using a silylation agent or silane coupling agent can be carried out by applying the silylation agent or silane coupling agent using, for example, a spin coating method or a dip method. Alternatively, treatment using a silylation agent or silane coupling agent can be carried out by forming a film containing a silylation agent or a film containing a silane coupling agent on the conductive layer 116, for example, using a gas phase method. In the gas phase method, first, a material containing a silylation agent or a material containing a silane coupling agent is volatilized to introduce the silylation agent or silane coupling agent into the atmosphere. Subsequently, a substrate on which the conductive layer 116 is formed is placed in this atmosphere. This allows a film containing a silylation agent or silane coupling agent to be formed on the conductive layer 116, thereby hydrophobicizing the surface of the conductive layer 116.

[0210] If the conductive layer 116 shown in Figure 1B, etc., is not provided, the aforementioned hydrophobic treatment can be performed on the pixel electrode 111.

[0211] Next, an EL layer 113 is formed on conductive layers 116a, 116b, 116c, and 116p (Figure 14B). At this time, an organic layer 119 may be formed in the opening 187.

[0212] As shown in Figure 14B, 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 a mask (also called an area mask or rough metal mask, to distinguish it from a fine metal mask) to determine the region on which the EL layer 113 is formed, the EL layer 113 can be deposited only in the desired region.

[0213] The EL layer 113 is preferably formed using a method with low coverage. The EL layer 113 can be formed, for example, by vapor deposition, specifically by vacuum deposition. Alternatively, the EL layer 113 may be formed by methods such as transfer, printing, inkjet, or coating.

[0214] As shown in Figure 14B, multiple island-shaped EL layers 113 can be formed without using a fine metal mask. This suppresses contact between the EL layers 113 in adjacent subpixels. Therefore, leakage current between subpixels can be suppressed. This suppresses a decrease in the display quality of the display device. Furthermore, it is possible to achieve both high resolution and high display quality in the display device.

[0215] As described above, by forming island-shaped EL layers 113 using apertures 187 created by photolithography, the distance between two adjacent EL layers 113 can be reduced. By reducing the distance between the island-shaped EL layers 113 in this way, a display device with high resolution and a high aperture ratio can be realized.

[0216] Next, a common electrode 115 is formed on the EL layer 113 and the conductive layer 116p (Figure 14C). It is preferable to form the common electrode 115 using a method that provides higher coverage than the formation of the EL layer 113. For example, sputtering can be used to form the common electrode 115. Alternatively, a film formed by vapor deposition and a film formed by sputtering may be laminated together.

[0217] Next, a protective layer 131 is formed on the common electrode 115, and colored layers 132R, 132G, and 132B are formed on the protective layer 131. Furthermore, a substrate 120 is bonded to the protective layer 131 and the colored layers 132 using a resin layer 122 to fabricate a display device (Figure 6).

[0218] The protective layer 131 can be formed using vacuum deposition, sputtering, CVD, or ALD.

[0219] 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. Therefore, it can be made smaller than the size of an EL layer formed using a fine metal mask. Consequently, 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. Furthermore, even if the resolution or aperture ratio is high and the distance between subpixels is extremely short, it is possible to suppress the contact between the island-shaped EL layers 113 in adjacent subpixels. Consequently, it is possible to suppress the generation of leakage current between subpixels. This suppresses a decrease in the display quality of the display device. In addition, it becomes possible to achieve both high resolution and high display quality in the display device.

[0220] This embodiment can be combined with other embodiments as appropriate.

[0221] (Embodiment 2) In this embodiment, a display device according to one aspect of the present invention will be described with reference to Figures 15 and 16.

[0222] [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.

[0223] 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.

[0224] The top surface shape of the sub-pixels may include, for example, polygons such as triangles, quadrilaterals (including rectangles and squares), pentagons, polygons with rounded corners, ellipses, or circles.

[0225] The circuit layout constituting the subpixel is not limited to the subpixel range shown in the figure, but may be located outside of it.

[0226] The pixel 110 shown in Figure 15A has an S-stripe array applied to it. The pixel 110 shown in Figure 15A is composed of three subpixels: subpixel 110a, subpixel 110b, and subpixel 110c.

[0227] The pixel 110 shown in Figure 15B includes sub-pixels 110a and 110b, which have a roughly trapezoidal or triangular top surface shape with rounded corners, and sub-pixel 110c, which has a roughly square 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.

[0228] A Pentile array is applied to pixels 124a and 124b shown in Figure 15C. Figure 15C 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.

[0229] Pixels 124a and 124b, shown in Figures 15D to 15F, have a delta array applied. 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).

[0230] Figure 15D shows an example where each subpixel has a roughly square top shape with rounded corners, Figure 15E shows an example where each subpixel has a circular top shape, and Figure 15F shows an example where each subpixel has a roughly hexagonal top shape with rounded corners.

[0231] Figure 15G 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 row direction (for example, subpixels 110a and 110b, or subpixels 110b and 110c) are offset.

[0232] In each pixel shown in Figures 15A to 15G, 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.

[0233] In photolithography, the finer the pattern to be processed, the more significant the effects of light diffraction become. This compromises the fidelity of transferring the photomask pattern through exposure, making it difficult to process the resist mask into the desired shape. As a result, even if the photomask pattern is rectangular, patterns with rounded corners are likely to be formed. In a top view, the contour of the edge of aperture 187 may be, for example, a polygon with rounded corners, an ellipse, or a circle.

[0234] In a method for manufacturing a display device according to one aspect of the present invention, an island-shaped EL layer 113 is formed by a step created by the opening 187. Therefore, in a top view, the top surface shape of the EL layer may not coincide with the contour of the opening 187. The top surface shape of the EL layer may be, for example, a polygon with rounded corners, an ellipse, or a circle.

[0235] As shown in Figures 16A to 16I, a pixel can be configured to have four types of subpixels.

[0236] The pixels 110 shown in Figures 16A to 16C have a stripe arrangement applied to them.

[0237] Figure 16A shows an example where each subpixel has a rectangular top surface shape, Figure 16B shows an example where each subpixel has a top surface shape formed by connecting two semicircles and a rectangle, and Figure 16C shows an example where each subpixel has an elliptical top surface shape.

[0238] The pixels 110 shown in Figures 16D to 16F have a matrix array applied to them.

[0239] Figure 16D shows an example where each subpixel has a square top surface shape, Figure 16E shows an example where each subpixel has a roughly square top surface shape with rounded corners, and Figure 16F shows an example where each subpixel has a circular top surface shape.

[0240] Figures 16G and 16H show an example where one pixel 110 is composed of 2 rows and 3 columns.

[0241] Pixel 110, shown in Figure 16G, 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.

[0242] The pixel 110 shown in Figure 16H 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 16H, 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.

[0243] Figure 16I shows an example where one pixel 110 is composed of a 3x2 grid.

[0244] Pixel 110, shown in Figure 16I, 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.

[0245] The pixel 110 shown in Figures 16A to 16I is composed of four subpixels: subpixels 110a, 110b, 110c, and 110d.

[0246] The sub-pixels 110a, 110b, 110c, and 110d can each be configured to have light-emitting devices with different emission colors. 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 R, G, B, and infrared (IR).

[0247] In each pixel 110 shown in Figures 16A to 16I, it is preferable, for example, that sub-pixel 110a emits red light, sub-pixel 110b emits green light, sub-pixel 110c emits blue light, and sub-pixel 110d emits either white light, yellow light, or near-infrared light. With such a configuration, in the pixels 110 shown in Figures 16G and 16H, 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 16I, the layout of R, G, and B becomes a so-called S-stripe arrangement, which can improve the display quality.

[0248] As shown in Figures 16J and 16K, a pixel can be configured to have five types of subpixels. Examples of five subpixels include those of the five colors R, G, B, Y, and W.

[0249] Figure 16J shows an example where one pixel 110 is composed of 2 rows and 3 columns.

[0250] Pixel 110, shown in Figure 16J, has three subpixels (subpixels 110a, 110b, and 110c) in the top row (row 1) and two subpixels (subpixels 110d and 110e) in the bottom row (row 2). In other words, pixel 110 has subpixels 110a and 110d in the left column (column 1), subpixel 110b in the middle column (column 2), subpixel 110c in the right column (column 3), and subpixel 110e extending from column 2 to column 3.

[0251] Figure 16K shows an example where one pixel 110 is composed of 3 rows and 2 columns.

[0252] Pixel 110, shown in Figure 16K, has subpixel 110a in the top row (1st row), subpixel 110b in the middle row (2nd row), subpixel 110c spanning from the 1st to the 2nd row, and two subpixels (subpixels 110d and 110e) in the bottom row (3rd row). In other words, pixel 110 has subpixels 110a, 110b, and 110d in the left column (1st column), and subpixels 110c and 110e in the right column (2nd column).

[0253] As described above, in one aspect of the present invention, a display device can be configured to have various layouts applied to pixels that consist of subpixels having light-emitting devices.

[0254] This embodiment can be combined with other embodiments as appropriate.

[0255] (Embodiment 3) In this embodiment, a display device according to one aspect of the present invention will be described with reference to Figures 17 to 26.

[0256] 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.

[0257] 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.

[0258] [Display Module] Figure 17A 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.

[0259] 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.

[0260] Figure 17B shows a schematic perspective view illustrating the configuration of the substrate 291. On the substrate 291, a circuit section 282, a pixel circuit section 283 on the circuit section 282, and a pixel section 284 on the pixel circuit section 283 are stacked. In addition, a terminal section 285 for connecting to the FPC 290 is provided in the portion of the substrate 291 that does not overlap with the pixel section 284. The terminal section 285 and the circuit section 282 are electrically connected by a wiring section 286, which is composed of multiple wires.

[0261] The pixel section 284 has a plurality of pixels 284a arranged periodically. The right side of Figure 17B shows an enlarged view of one pixel 284a. Various configurations described in the previous embodiment can be applied to the pixel 284a. Figure 17B shows an example where the pixel has a configuration similar to that of the pixel 110 shown in Figure 1A.

[0262] The pixel circuit section 283 has a plurality of pixel circuits 283a arranged periodically.

[0263] 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.

[0264] The circuit section 282 has circuits for driving each pixel circuit 283a of the pixel circuit section 283. For example, it is preferable to have one or both of a gate line drive circuit and a source line drive circuit. In addition, it may have at least one of the following: an arithmetic circuit, a memory circuit, and a power supply circuit.

[0265] 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.

[0266] 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.

[0267] 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.

[0268] [Display device 100A] The display device 100A shown in Figure 18A includes a substrate 301, light-emitting devices 130R, 130G, 130B, a colored layer 132R, 132G, 132B, a capacitor 240, and a transistor 310.

[0269] As shown in Figure 17B, sub-pixel 110R has a light-emitting device 130R and a colored layer 132R, sub-pixel 110G has a light-emitting device 130G and a colored layer 132G, and sub-pixel 110B has a light-emitting device 130B and a colored layer 132B. In sub-pixel 110R, the light emitted by the light-emitting device 130R is extracted as red light to the outside of the display device 100A via the colored layer 132R. Similarly, in sub-pixel 110G, the light emitted by the light-emitting device 130G is extracted as green light to the outside of the display device 100A via the colored layer 132G. In sub-pixel 110B, the light emitted by the light-emitting device 130B is extracted as blue light to the outside of the display device 100A via the colored layer 132B.

[0270] Substrate 301 corresponds to substrate 291 in Figures 17A and 17B. The laminated structure from substrate 301 to insulating layer 255c corresponds to layer 101 containing the transistor in Embodiment 1.

[0271] The transistor 310 is a transistor having a channel-forming region in the substrate 301. For example, a semiconductor substrate such as a single-crystal silicon substrate can be used as the substrate 301. The transistor 310 comprises a portion of the substrate 301, a conductive layer 311, a low-resistance region 312, an insulating layer 313, and an insulating layer 314. The conductive layer 311 functions as a gate electrode. The insulating layer 313 is located between the substrate 301 and the conductive layer 311 and functions as a gate insulating layer. The low-resistance region 312 is a region of the substrate 301 doped with impurities and functions as either a source or a drain. The insulating layer 314 is provided covering the side surface of the conductive layer 311.

[0272] An element isolation layer 315 is provided between two adjacent transistors 310 so as to be embedded in the substrate 301.

[0273] An insulating layer 261 is provided covering the transistor 310, and a capacitance 240 is provided on the insulating layer 261.

[0274] The capacitor 240 has a conductive layer 241, a conductive layer 245, and an insulating layer 243 positioned therebetween. The conductive layer 241 functions as one electrode of the capacitor 240, the conductive layer 245 functions as the other electrode of the capacitor 240, and the insulating layer 243 functions as the dielectric of the capacitor 240.

[0275] The conductive layer 241 is provided on the insulating layer 261 and is embedded in the insulating layer 254. The conductive layer 241 is electrically connected to one of the source or drain of the transistor 310 by a plug 271 embedded in the insulating layer 261. The insulating layer 243 is provided to cover the conductive layer 241. The conductive layer 245 is provided in a region overlapping the conductive layer 241 via the insulating layer 243.

[0276] Note that in at least one layer of the conductive layers included in the layer 101 including the transistor, it is preferable to provide a conductive layer surrounding the outside of the display portion 281 (or the pixel portion 284). The said conductive layer can also be called a guard ring. By providing the said conductive layer, it is possible to suppress a high voltage from being applied to elements such as transistors and light emitting devices due to charging by a process using ESD (electrostatic discharge) or plasma, and these elements being destroyed.

[0277] An insulating layer 255a is provided to cover the capacitor 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. FIG. 18A shows an example in which the light emitting devices 130R, 130G, and 130B have the stacked structure shown in FIG. 1B. An insulating layer 181 is provided in the region between adjacent light emitting devices.

[0278] Pixel electrodes 111a, 111b, and 111c 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 upper surface of insulating layer 255c and the height of the upper surface of plug 256 are equal or approximately equal. Various conductive materials can be used for the plugs. Figure 18A, etc., shows an example in which the pixel electrode has a two-layer structure consisting of a reflective electrode and a transparent electrode on the reflective electrode.

[0279] A protective layer 131 is provided on the light-emitting devices 130R, 130G, and 130B. A substrate 120 is bonded to the protective layer 131 by a resin layer 122. Details of the components from the light-emitting devices to the substrate 120 can be found in Embodiment 1. The substrate 120 corresponds to the substrate 292 in Figure 17A.

[0280] [Display device 100B] The display device 100B shown in Figure 19 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.

[0281] 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.

[0282] Here, it is preferable to provide an insulating layer 345 on the lower surface of substrate 301B. It is also preferable to provide an insulating layer 346 on top of the insulating layer 261 provided on substrate 301A. Insulating layers 345 and 346 are insulating layers that function as protective layers and can suppress the diffusion of impurities into substrates 301B and 301A. Insulating layers 345 and 346 can be made of inorganic insulating films that can be used for protective layer 131 or insulating layer 332.

[0283] The substrate 301B is provided with a plug 343 that penetrates both the substrate 301B and the insulating layer 345. It is preferable to provide an insulating layer 344 covering the sides of the plug 343. The insulating layer 344 functions as a protective layer and can suppress the diffusion of impurities into the substrate 301B. The insulating layer 344 can be made of an inorganic insulating film that can be used for the protective layer 131.

[0284] A conductive layer 342 is provided on the back side of the substrate 301B (the side opposite to the substrate 120 side), beneath the insulating layer 345. Preferably, the conductive layer 342 is provided so as to be embedded in the insulating layer 335. Also, preferably, the undersides of the conductive layer 342 and the insulating layer 335 are flattened. Here, the conductive layer 342 is electrically connected to the plug 343.

[0285] 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.

[0286] 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.

[0287] It is preferable that conductive layers 341 and 342 use the same conductive material. For example, conductive layers 341 and 342 can be metal films containing elements selected from Al, Cr, Cu, Ta, Ti, Mo, and W, or metal nitride films (titanium nitride film, molybdenum nitride film, tungsten nitride film) composed of the above elements. In particular, it is preferable to use copper for conductive layers 341 and 342. This allows the application of Cu-Cu (copper-copper) direct bonding technology (a technology that achieves electrical conductivity by connecting Cu (copper) pads to each other).

[0288] [Display device 100C] The display device 100C shown in Figure 20 has a configuration in which conductive layer 341 and conductive layer 342 are joined via bumps 347.

[0289] As shown in Figure 20, 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 may be omitted.

[0290] [Display device 100D] The display device 100D shown in Figure 21 differs from the display device 100A mainly in its transistor configuration.

[0291] Transistor 320 is an OS transistor in which a metal oxide (also called an oxide semiconductor) with semiconductor properties is applied to the semiconductor layer where the channel is formed.

[0292] 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.

[0293] The substrate 331 corresponds to the substrate 291 in FIGS. 17A and 17B. The stacked structure from the substrate 331 to the insulating layer 255c corresponds to the layer 101 including the transistor in Embodiment 1. As the substrate 331, an insulating substrate or a semiconductor substrate can be used.

[0294] An insulating layer 332 is provided on the substrate 331. The insulating layer 332 functions as a barrier layer that prevents impurities such as water or hydrogen from diffusing from the substrate 331 into the transistor 320 and prevents oxygen from desorbing from the semiconductor layer 321 to the insulating layer 332 side. As the insulating layer 332, for example, a film such as an aluminum oxide film, a hafnium oxide film, or a silicon nitride film, in which hydrogen or oxygen diffuses less easily than in a silicon oxide film, can be used.

[0295] A conductive layer 327 is provided on the insulating layer 332, and an insulating layer 326 is provided to cover the conductive layer 327. The conductive layer 327 functions as the first gate electrode of the transistor 320, and a part of the insulating layer 326 functions as the first gate insulating layer. It is preferable to use an oxide insulating film such as a silicon oxide film for at least the portion of the insulating layer 326 that contacts the semiconductor layer 321. The upper surface of the insulating layer 326 is preferably flattened.

[0296] The semiconductor layer 321 is provided on the insulating layer 326. The semiconductor layer 321 preferably has a metal oxide (oxide semiconductor) film having semiconductor characteristics. A pair of conductive layers 325 are provided in contact with the semiconductor layer 321 and function as source electrodes and drain electrodes.

[0297] An insulating layer 328 is provided to cover the upper surfaces and side surfaces of the pair of conductive layers 325 and the side surfaces of the semiconductor layer 321, etc., and an insulating layer 264 is provided on the insulating layer 328. The insulating layer 328 functions as a barrier layer that prevents impurities such as water or hydrogen from diffusing from the insulating layer 264, etc. into the semiconductor layer 321 and prevents oxygen from desorbing from the semiconductor layer 321. The insulating layer 328 can use the same insulating film as the insulating layer 332 described above.

[0298] 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.

[0299] 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.

[0300] 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 from insulating layer 265 to transistor 320. Insulating layer 329 can be an insulating film similar to that used for insulating layers 328 and 332.

[0301] 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.

[0302] [Display device 100E] The display device 100E shown in Figure 22 has a configuration in which transistors 320A and 320B, each having an oxide semiconductor in the semiconductor on which the channel is formed, are stacked.

[0303] For details regarding transistors 320A and 320B, and their peripheral configurations, please refer to the display device 100D described above.

[0304] 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.

[0305] [Display device 100F] The display device 100F shown in Figure 23 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.

[0306] 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.

[0307] 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.

[0308] 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.

[0309] [Display device 100G] Figure 24 shows a perspective view of the display device 100G, and Figure 25A shows a cross-sectional view of the display device 100G.

[0310] The display device 100G has a configuration in which substrate 152 and substrate 151 are bonded together. In Figure 24, substrate 152 is clearly indicated by a dashed line.

[0311] The display device 100G includes a display unit 162, a connection unit 140, a circuit 164, wiring 165, etc. Figure 24 shows an example in which IC 173 and FPC 172 are mounted on the display device 100G. Therefore, the configuration shown in Figure 24 can also be described as a display module having the display device 100G, an IC (integrated circuit), and an FPC.

[0312] The connection portion 140 is provided on the outside of the display portion 162. The connection portion 140 can be provided along one or more sides of the display portion 162. There may be one or more connection portions 140. Figure 24 shows an example in which the connection portion 140 is provided so as to surround all four sides of the display portion. At the connection portion 140, the common electrode of the light-emitting device and the conductive layer are electrically connected, and a potential can be supplied to the common electrode.

[0313] For example, a scan line drive circuit can be used as circuit 164.

[0314] Wiring 165 has the function of supplying signals and power to the display unit 162 and the circuit 164. These signals and power are input to wiring 165 from an external source via FPC 172 or from IC 173.

[0315] Figure 24 shows an example in which IC 173 is provided on the substrate 151 using a COG (Chip On Glass) method or COF (Chip On Film) method, 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 a COF method, etc.

[0316] Figure 25A 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.

[0317] The display device 100G shown in Figure 25A has, between substrates 151 and 152, a transistor 201, a transistor 205, a light-emitting device 130R that emits red light, a light-emitting device 130G that emits green light, a light-emitting device 130B, a colored layer 132R that transmits red light, a colored layer 132G that transmits green light, and a colored layer 132B that transmits blue light, etc.

[0318] The light-emitting devices 130R, 130G, and 130B can be configured as shown in Embodiment 1, etc., except that the pixel electrode configuration differs.

[0319] The light-emitting device 130R has a conductive layer 112a and a conductive layer 126a on the conductive layer 112a. The conductive layer 112a and the conductive layer 126a correspond to the pixel electrode 111a shown in Embodiment 1.

[0320] The light-emitting device 130G has a conductive layer 112b and a conductive layer 126b on the conductive layer 112b.

[0321] The light-emitting device 130B has a conductive layer 112c and a conductive layer 126c on the conductive layer 112c.

[0322] The conductive layer 112a is connected to the conductive layer 222b of the transistor 205 through an opening provided in the insulating layer 214. The edge of the conductive layer 126a is located outside the edge of the conductive layer 112a. The conductive layer 116a is provided on the conductive layer 126a. The conductive layer 116a functions as an optical adjustment layer. For example, conductive layers that are reflective to visible light can be used for conductive layers 112a and 126a, and conductive layers that are transparent to visible light can be used for conductive layer 116a.

[0323] The conductive layers 112b, 126b, and 116b in the light-emitting device 130G, and the conductive layers 112c, 126c, and 116c in the light-emitting device 130B, are the same as the conductive layers 112a, 126a, and 116a in the light-emitting device 130R, so a detailed explanation is omitted.

[0324] The conductive layers 112a, 112b, and 112c have recesses formed in them so as to cover the openings provided in the insulating layer 214. Layer 128 is embedded in these recesses.

[0325] Layer 128 has the function of flattening the recesses of conductive layers 112a, 112b, and 112c. Conductive layers 126a, 126b, and 126c, which are electrically connected to conductive layers 112a, 112b, and 112c, are provided on conductive layers 112a, 112b, and 112c and on layer 128. Therefore, regions overlapping with the recesses of conductive layers 112a, 112b, and 112c can also be used as light-emitting regions, thereby increasing the aperture ratio of the pixels.

[0326] 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. For example, an organic insulating material that can be used for the protective layer 131 described above can be applied to layer 128.

[0327] 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 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 encapsulate the light-emitting device 130. In Figure 25A, 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 device. Furthermore, the space may be filled with a resin different from the adhesive layer 142, which is provided in a frame shape.

[0328] In the connection portion 140, a conductive layer 123 is provided on the insulating layer 214. The conductive layer 123 can have a laminated structure of a conductive film obtained by processing the same conductive film as conductive layers 112a, 112b, and 112c, and a conductive film obtained by processing the same conductive film as conductive layers 126a, 126b, and 126c. The ends of the conductive layer 123 are covered by the insulating layer 181. In addition, a conductive layer 116p is provided on the conductive layer 123, and a common electrode 115 is provided on the conductive layer 116p. The conductive layer 123 and the common electrode 115 are electrically connected via the conductive layer 116p. Note that the conductive layer 116p does not have to be formed in the connection portion 140. In this case, the conductive layer 123 and the common electrode 115 are in direct contact and electrically connected.

[0329] 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.

[0330] The laminated structure from the substrate 151 to the insulating layer 214 corresponds to the layer 101 containing the transistor in Embodiment 1.

[0331] Both transistors 201 and 205 are formed on the substrate 151. These transistors can be manufactured using the same materials and the same process.

[0332] 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.

[0333] 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.

[0334] Insulating layers 211, 213, and 215 are preferably made of inorganic insulating films. 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, and neodymium oxide may also be used. Furthermore, two or more of the above insulating films may be laminated together.

[0335] 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 recesses in the insulating layer 214 when processing the conductive layer 112a or conductive layer 126a. Alternatively, recesses may be provided in the insulating layer 214 when processing the conductive layer 112a or conductive layer 126a.

[0336] Transistors 201 and 205 have a conductive layer 221 that functions as a gate, an insulating layer 211 that functions as a gate insulating layer, conductive layers 222a and 222b that function as source and drain, a semiconductor layer 231, an insulating layer 213 that functions as a gate insulating layer, and a conductive layer 223 that functions as a gate. Here, the same hatching pattern is applied to multiple layers obtained by processing the same conductive film. The insulating layer 211 is located between the conductive layer 221 and the semiconductor layer 231. The insulating layer 213 is located between the conductive layer 223 and the semiconductor layer 231.

[0337] The transistor structure of the display device of this embodiment is not particularly limited. For example, planar transistors, staggered transistors, inverse staggered transistors, etc., can be used. Furthermore, either a top-gate or bottom-gate transistor structure may be used. Alternatively, gates may be provided above and below the semiconductor layer in which the channel is formed.

[0338] Transistors 201 and 205 are configured in which a semiconductor layer on which a channel is formed is sandwiched between two gates. The transistors may be driven by connecting the two gates and supplying them with the same signal. Alternatively, the threshold voltage of the transistors may be controlled by applying a potential to control the threshold voltage to one of the two gates and a potential to drive the other gate.

[0339] 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-crystal semiconductors (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.

[0340] The semiconductor layer of the transistor preferably has a metal oxide (oxide semiconductor) that has semiconductor properties. 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.

[0341] Examples of crystalline oxide semiconductors include CAAC (c-axis-aligned crystalline)-OS and nc (nanocrystalline)-OS.

[0342] Alternatively, a transistor using silicon as the channel-forming region (Si transistor) may be used. Examples of silicon include single-crystal silicon, polycrystalline silicon, and amorphous silicon. In particular, a transistor having low-temperature polysilicon (LTPS (Low Temperature Poly Silicon)) in the semiconductor layer (hereinafter also referred to as an LTPS transistor) can be used. LTPS transistors have high field-effect mobility and good frequency characteristics.

[0343] 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.

[0344] 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.

[0345] To increase the luminescence brightness of a light-emitting device included in a pixel circuit, it is necessary to increase the amount of current flowing through the device. To achieve this, the source-drain voltage of the drive transistor included in the pixel circuit must be increased. Compared to Si transistors, OS transistors have a higher breakdown voltage between the source and drain, allowing a higher voltage to be applied to the source-drain of an OS transistor. Therefore, by using an OS transistor as the drive transistor in the pixel circuit, the amount of current flowing through the light-emitting device can be increased, thereby increasing the luminescence brightness of the device.

[0346] When a transistor operates in the saturation region, an OS transistor exhibits a smaller change in source-drain current in response to a change in gate-source voltage compared to a Si transistor. Therefore, by using an OS transistor as the driving transistor in a pixel circuit, the current flowing between the source and drain can be precisely controlled by the change 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.

[0347] 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.

[0348] 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."

[0349] The metal oxide in the semiconductor layer preferably contains, for example, indium, M (where M is one or more selected from gallium, aluminum, silicon, boron, yttrium, tin, copper, vanadium, beryllium, titanium, iron, nickel, germanium, zirconium, molybdenum, lanthanum, cerium, neodymium, hafnium, tantalum, tungsten, and magnesium), and zinc. In particular, it is preferable that M is one or more selected from aluminum, gallium, yttrium, and tin.

[0350] 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).

[0351] When the semiconductor layer is an In-M-Zn oxide, it is preferable that the atomic ratio of In in the In-M-Zn oxide is greater than or equal to the atomic ratio of M. Possible atomic ratios of metal elements in such an In-M-Zn oxide include: In:M:Zn=1:1:1 or near that composition, In:M:Zn=1:1:1.2 or near that composition, In:M:Zn=1:3:2 or near that composition, In:M:Zn=1:3:4 or near that composition, In:M:Zn=2:1:3 or near that composition, In:M:Zn=3:1:2 or near that composition, and In:M:Zn=4:2:3 Examples include compositions near the desired atomic ratio, such as In:M:Zn=4:2:4.1 or near that ratio, In:M:Zn=5:1:3 or near that ratio, In:M:Zn=5:1:6 or near that ratio, In:M:Zn=5:1:7 or near that ratio, In:M:Zn=5:1:8 or near that ratio, In:M:Zn=6:1:6 or near that ratio, In:M:Zn=5:2:5 or near that ratio, etc. Note that "nearby composition" includes a range of ±30% of the desired atomic ratio.

[0352] For example, when describing a composition with an atomic ratio of In:Ga:Zn = 4:2:3 or a similar ratio, it includes cases where, with In being 4, Ga is between 1 and 3, and Zn is between 2 and 4. Also, when describing a composition with an atomic ratio of In:Ga:Zn = 5:1:6 or a similar ratio, it includes cases where, with In being 5, Ga is greater than 0.1 and 2 or less, and Zn is between 5 and 7. Furthermore, when describing a composition with an atomic ratio of In:Ga:Zn = 1:1:1 or a similar ratio, it includes cases where, with In being 1, Ga is greater than 0.1 and 2 or less, and Zn is greater than 0.1 and 2 or less.

[0353] 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.

[0354] 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.

[0355] For example, by using both LTPS transistors and OS transistors in the display unit 162, a display device with low power consumption and high driving capability can be realized. Furthermore, a configuration combining LTPS transistors and OS transistors is sometimes referred to as LTPO. It is more preferable to use OS transistors for transistors that function as switches to control conduction and non-conduction between wires, and LTPS transistors for transistors that control current.

[0356] 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.

[0357] 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.

[0358] 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.

[0359] 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 achieve a display with as little light leakage (so-called black floating) that may occur when displaying black as possible.

[0360] Figures 25B and 25C show other examples of transistor configurations.

[0361] Transistors 209 and 210 each have a conductive layer 221 that functions as a gate, an insulating layer 211 that functions as a gate insulating layer, a semiconductor layer 231 having a channel forming region 231i and a pair of low-resistance regions 231n, a conductive layer 222a connected to one of the pair of low-resistance regions 231n, a conductive layer 222b connected to the other of the pair of low-resistance regions 231n, an insulating layer 225 that functions as a gate insulating layer, a conductive layer 223 that functions as a gate, and an insulating layer 215 covering the conductive layer 223. The insulating layer 211 is located between the conductive layer 221 and the channel forming region 231i. The insulating layer 225 is located at least between the conductive layer 223 and the channel forming region 231i. Furthermore, an insulating layer 218 covering the transistor may be provided.

[0362] In the transistor 209 shown in Figure 25B, an example is shown where the insulating layer 225 covers the top and sides of the semiconductor layer 231. The conductive layers 222a and 222b are connected to the low-resistance region 231n through openings provided in the insulating layers 225 and 215, respectively. Of the conductive layers 222a and 222b, one functions as the source and the other as the drain.

[0363] On the other hand, in the transistor 210 shown in Figure 25C, 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 25C can be fabricated by processing the insulating layer 225 using the conductive layer 223 as a mask. In Figure 25C, 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.

[0364] 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, conductive layer 116q, and connection layer 242. Conductive layer 166 can have a laminated structure of a conductive film obtained by processing the same conductive film as conductive layers 112a, 112b, and 112c, and a conductive film obtained by processing the same conductive film as conductive layers 126a, 126b, and 126c. Conductive layer 116q can be formed by processing the same conductive film as conductive layer 116a, conductive layer 116b, or conductive layer 116c. For example, conductive layer 116q can be formed in the same process as conductive layer 116c, and as shown in Figure 25A, the film thickness of conductive layer 116q can be equal to or approximately equal to the film thickness of conductive layer 116c.

[0365] In the connection portion 204, it is preferable that the end of the conductive layer 116p is covered with an insulating layer 168 so that the surface of the conductive layer 116p is not exposed. By covering the end of the conductive layer 116p with an insulating layer 168, oxidation of the conductive layer 116p and problems such as short circuits can be suppressed. Note that the conductive layer 116q is not required. If the conductive layer 116q is not provided, the end of the conductive layer 166 may be covered with an insulating layer 168. Alternatively, the conductive layer 166 may be electrically connected to the FPC 172 via the connection layer 242.

[0366] It is preferable to provide a light-shielding layer 117 on the surface of the substrate 152 that faces the substrate 151. The light-shielding layer 117 can be provided between adjacent light-emitting devices, at connection points 140, and in circuits 164, etc. In addition, various optical components can be arranged on the outside of the substrate 152.

[0367] Substrates 151 and 152 can each be made of materials that can be used for substrate 120.

[0368] The adhesive layer 142 can be made of a material that can be used for the resin layer 122.

[0369] The connecting layer 242 can be made of an anisotropic conductive film (ACF), an anisotropic conductive paste (ACP), or the like.

[0370] [Display device 100H] The display device 100H shown in Figure 26 differs from the display device 100G mainly in that it is a bottom-emission type display device.

[0371] The light emitted by the light-emitting device is projected onto the substrate 151. It is preferable to use a material with high transparency to visible light for the substrate 151. On the other hand, the light transmittance of the material used for the substrate 152 is not a requirement.

[0372] 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 26 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 and 205 are provided on the insulating layer 153.

[0373] The conductive layers 112a, 112b, 126a, and 126b are each made of materials with high transmittance to visible light. It is preferable to use a material that reflects visible light for the common electrode 115.

[0374] Figures 25A and 26 show an example in which layer 128 has a flat upper surface, but the shape of layer 128 is not particularly limited. The upper surface of layer 128 can 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. Alternatively, the upper surface of layer 128 can have a shape in which the center and its vicinity are bulging in a cross-sectional view, that is, a shape having a convex curved surface.

[0375] The upper surface of layer 128 may have one or both of a convex and a concave surface. Furthermore, the number of convex and concave surfaces on the upper surface of layer 128 is not limited and can be one or more.

[0376] The height of the top surface of layer 128 and the height of the top surface of conductive layer 112a 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 112a.

[0377] This embodiment can be combined with other embodiments as appropriate.

[0378] (Embodiment 4) This embodiment describes a light-emitting device that can be used in a display device according to one aspect of the present invention.

[0379] As shown in Figure 27A, 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.

[0380] The light-emitting layer 771 has at least a light-emitting substance (also called a light-emitting material).

[0381] 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.

[0382] 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 27A is referred to as a single structure.

[0383] Figure 27B shows a modified example of the EL layer 763 of the light-emitting device shown in Figure 27A. Specifically, the light-emitting device shown in Figure 27B 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.

[0384] 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.

[0385] As shown in Figures 27C and 27D, a configuration in which multiple light-emitting layers (light-emitting layers 771, 772, and 773) are provided between layer 780 and layer 790 is also a variation of the single structure. Although Figures 27C and 27D show an example with three light-emitting layers, the number of light-emitting layers in a single-structure light-emitting device may be two or four or more. Furthermore, a single-structure light-emitting device may have a buffer layer between the two light-emitting layers.

[0386] As shown in Figures 27E and 27F, a configuration in which multiple light-emitting units (light-emitting units 763a and 763b) are connected in series via a charge generation layer 785 is referred to as a tandem structure in this specification. The tandem structure may also be called a stack structure. By using a tandem structure, a light-emitting device capable of high-brightness light emission can be made. Furthermore, compared to a single structure, the tandem structure can reduce the current required to obtain the same brightness, thereby improving reliability. The charge generation layer is also called an intermediate layer.

[0387] Figures 27D and 27F show examples in which the display device has a layer 764 that overlaps with the light-emitting device. Figure 27D shows an example in which layer 764 overlaps with the light-emitting device shown in Figure 27C, and Figure 27F shows an example in which layer 764 overlaps with the light-emitting device shown in Figure 27E.

[0388] As layer 764, either or both of the color conversion layer and / or the color filter (coloring layer) can be used.

[0389] In Figures 27C and 27D, the light-emitting layers 771, 772, and 773 may be made of light-emitting materials that emit light of the same color, or even the same light-emitting material. For example, light-emitting materials that emit blue light may be used for the light-emitting layers 771, 772, and 773. Subpixels that emit blue light can extract the blue light emitted by the light-emitting device. Furthermore, subpixels that emit red light and subpixels that emit green light can be made to emit red or green light by providing a color conversion layer as layer 764 as shown in Figure 27D, which converts the blue light emitted by the light-emitting device into longer wavelength light.

[0390] Light-emitting materials with different emission colors may be used for each of the light-emitting layers 771, 772, and 773. White light emission is obtained when the light emitted by each of the light-emitting layers 771, 772, and 773 is in a complementary color relationship. 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.

[0391] 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.

[0392] 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.

[0393] A color filter (also called a colored layer) may be provided as layer 764 as shown in Figure 27D. By passing white light through the color filter, light of the desired color can be obtained.

[0394] A light-emitting device that emits white light preferably contains two or more types of light-emitting materials. To obtain white light emission, one should select light-emitting materials such that the light emitted by each of the two or more materials is complementary in color. For example, by making the light-emitting color of the first light-emitting layer and the light-emitting color of the second light-emitting layer complementary, a light-emitting device that emits white light as a whole can be obtained. The same applies to light-emitting devices that have three or more light-emitting layers.

[0395] In Figures 27E and 27F, the light-emitting layer 771 and the light-emitting layer 772 may be made of light-emitting materials that emit light of the same color, or even the same light-emitting material may be used for both.

[0396] For example, in a light-emitting device having subpixels that emit light of each color, light-emitting materials that emit blue light may be used in the light-emitting layer 771 and the light-emitting layer 772, respectively. In the subpixels that emit blue light, the blue light emitted by the light-emitting device can be extracted. In addition, in the subpixels that emit red light and the subpixels that emit green light, a color conversion layer is provided as layer 764 as shown in Figure 27F, which converts the blue light emitted by the light-emitting device into longer wavelength light, allowing red or green light to be extracted.

[0397] Light-emitting materials with different emission colors may be used for the light-emitting layer 771 and the light-emitting layer 772. 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. Figure 27F shows an example in which an additional layer 764 is provided. Layer 764 can be a color conversion layer, a color filter (coloring layer), or both. By passing white light through the color filter, light of the desired color can be obtained.

[0398] Figures 27E and 27F show an example 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.

[0399] Figures 27E and 27F illustrate a light-emitting device having two light-emitting units, but it is not limited to this. A light-emitting device may have three or more light-emitting units. Specifically, the configurations of light-emitting devices shown in Figures 28A to 28C are examples.

[0400] Figure 28A shows a configuration with three light-emitting units. A configuration with two light-emitting units may also 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.

[0401] As shown in Figure 28A, the configuration consists of multiple light-emitting units (light-emitting unit 763a, light-emitting unit 763b, and light-emitting unit 763c) 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.

[0402] In the configuration shown in Figure 28A, it is preferable that the light-emitting layers 771, 772, and 773 each have a light-emitting material that emits light of the same color. Specifically, the configuration can be such that the light-emitting layers 771, 772, and 773 each have a red (R) light-emitting material (a so-called R\R\R three-stage tandem structure), the light-emitting layers 771, 772, and 773 each have a green (G) light-emitting material (a so-called G\G\G three-stage tandem structure), or the light-emitting layers 771, 772, and 773 each have a blue (B) light-emitting material (a so-called B\B\B three-stage tandem structure).

[0403] The light-emitting materials that each emit light of the same color are not limited to the above configuration. For example, as shown in Figure 28B, a tandem-type light-emitting device may be used in which multiple light-emitting units having multiple light-emitting materials are stacked. Figure 28B shows a configuration in which multiple 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 layer 771a, light-emitting layer 771b, light-emitting layer 771c, and layer 790a, and light-emitting unit 763b has layer 780b, light-emitting layer 772a, light-emitting layer 772b, light-emitting layer 772c, and layer 790b.

[0404] In the configuration shown in Figure 28B, the light-emitting layers 771a, 771b, and 771c are configured to emit white light (W) by selecting light-emitting materials that are complementary in color. Furthermore, the light-emitting layers 772a, 772b, and 772c are configured to emit white light (W) by selecting light-emitting materials that are complementary in color. That is, the configuration shown in Figure 28C is a two-stage tandem structure of W\W. There are no particular limitations on the stacking order of the complementary light-emitting materials in light-emitting layers 771a, 771b, and 771c. 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.

[0405] When using a tandem light-emitting device, there are two-stage tandem structures: B\Y having a light-emitting unit that emits yellow (Y) light and a light-emitting unit that emits blue (B) light; R·G\B having a light-emitting unit that emits red (R) and green (G) light and a light-emitting unit that emits blue (B) light; and a light-emitting unit that emits blue (B) light, a light-emitting unit that emits yellow (Y) light, and a light-emitting unit that emits blue (B) light. Examples include a B\Y\B three-stage tandem structure having the following elements in this order: a B\YG\B three-stage tandem structure 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: a B\G\B three-stage tandem structure 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:

[0406] As shown in Figure 28C, a light-emitting unit having one light-emitting material and a light-emitting unit having multiple light-emitting materials may be combined.

[0407] Specifically, in the configuration shown in Figure 28C, 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 layer 780a, light-emitting layer 771, and layer 790a; light-emitting unit 763b has layer 780b, light-emitting layer 772a, light-emitting layer 772b, light-emitting layer 772c, and layer 790b; and light-emitting unit 763c has layer 780c, light-emitting layer 773, and layer 790c.

[0408] For example, in the configuration shown in Figure 28C, 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.

[0409] 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.

[0410] In addition, in Figures 27C and 27D, as shown in Figure 27B, layer 780 and layer 790 may each be independently constructed as a laminated structure consisting of two or more layers.

[0411] In Figures 27E and 27F, 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.

[0412] 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.

[0413] 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. 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 771 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. 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 771 and the hole transport layer.

[0414] When fabricating a tandem light-emitting device, two light-emitting units are stacked with a charge generation layer 785 in between. The charge generation layer 785 has at least a charge generation region. When a voltage is applied between a pair of electrodes, the charge generation layer 785 has the function of injecting electrons into one of the two light-emitting units and holes into the other.

[0415] Next, we will describe materials that can be used in light-emitting devices.

[0416] 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.

[0417] A conductive film that transmits visible light may also be used on the electrode that does not extract light. In this case, it is preferable to place a conductive film that transmits visible light between the conductive film that reflects visible light and the EL layer 763. In other words, the light emitted from the EL layer 763 may be reflected by the conductive film that reflects visible light and extracted from the display device.

[0418] As materials for forming a pair of electrodes in a 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.

[0419] 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 is a semitransmitting / semi-reflective electrode that transmits and reflects visible light, and the other is a reflective electrode that reflects visible light. By having a microcavity structure in the light-emitting 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.

[0420] The semi-transparent / semi-reflective electrode can have a laminated structure of a conductive layer that reflects visible light and a conductive layer that transmits light. The transmittance of the conductive layer that transmits light should be 40% or more. For example, it is preferable to use an electrode in a light-emitting device that has a transmittance of 40% or more for visible light (light with a wavelength of 400 nm or more and less than 750 nm). The reflectance of the semi-transparent / semi-reflective electrode for visible light should be 10% or more and 95% or less, preferably 30% or more and 80% or less. The reflectance of the conductive layer that transmits light for visible light should be 40% or more and 100% or less, preferably 70% or more and 100% or less. The resistivity of these electrodes should be 1 × 10⁻⁶ -2 A value of Ωcm or less is preferable.

[0421] A light-emitting device has at least a light-emitting layer. The light-emitting device may further have layers other than the light-emitting layer, including materials with high hole injection properties, high hole transport properties, hole blocking properties, high electron transport properties, electron blocking properties, high electron injection properties, or bipolar materials (materials with high electron and hole transport properties). For example, a light-emitting device may have, in addition to the light-emitting layer, one or more layers from among a hole injection layer, a hole transport layer, a hole blocking layer, a charge generation layer, an electron blocking layer, an electron transport layer, and an electron injection layer.

[0422] 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.

[0423] The light-emitting layer has one or more types of light-emitting materials. The light-emitting materials may include substances that exhibit light-emitting colors such as blue, purple, blue-violet, green, yellow-green, yellow, orange, or red, as appropriate. Furthermore, materials that emit near-infrared light may also be used as light-emitting materials.

[0424] Examples of luminescent materials include fluorescent materials, phosphorescent materials, TADF materials, and quantum dot materials.

[0425] 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.

[0426] 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.

[0427] The light-emitting layer may contain one or more types of organic compounds (host material, assist material, etc.) in addition to the light-emitting substance (guest material). One or more of the organic compounds may be materials with high hole transport properties (hole transport material) and / or materials with high electron transport properties (electron transport material). Alternatively, one or more of the organic compounds may be bipolar materials or TADF materials.

[0428] 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.

[0429] The EL layer 763 may further include layers other than the light-emitting layer, such as a material with high hole injection properties, a material with high hole transport properties, a hole-blocking material, a material with high electron transport properties, a material with high electron injection properties, an electron-blocking material, or a bipolar material (a material with high electron transport and hole transport properties).

[0430] The hole injection layer is a layer that injects holes from the anode into the hole transport layer, and is a layer containing a material with high hole injection capabilities. Examples of materials with high hole injection capabilities include aromatic amine compounds and composite materials containing hole transport materials and acceptor materials (electron-accepting materials).

[0431] As the hole transport material, a material with high hole transport properties that can be used in the hole transport layer, as described later, can be used.

[0432] As acceptor materials, for example, oxides of metals belonging to groups 4 through 8 of the periodic table can be used. Specifically, these include molybdenum oxide, vanadium oxide, niobium oxide, tantalum oxide, chromium oxide, tungsten oxide, manganese oxide, and rhenium oxide. Among these, molybdenum oxide is particularly preferred because it is stable in the atmosphere, has low hygroscopicity, and is easy to handle. Organic acceptor materials containing fluorine can also be used. Furthermore, organic acceptor materials such as quinodimethane derivatives, chloranil derivatives, and hexaazatriphenylene derivatives can also be used.

[0433] For example, as a material with high hole injection properties, a material containing a hole transport material and an oxide of a metal belonging to Group 4 to Group 8 of the periodic table (typically molybdenum oxide) may be used.

[0434] The hole transport layer is a layer that transports holes injected from the anode by the hole injection layer to the light-emitting layer. The hole transport layer is a layer containing a hole-transporting material. The hole-transporting material is 1 × 10 -6 cm 2Materials having a hole mobility of / Vs or higher are preferred. However, other materials can also be used as long as they have higher hole transport capabilities than electron transport. Preferred hole transport materials are those with high hole transport capabilities, such as π-electron-rich heteroaromatic compounds (e.g., carbazole derivatives, thiophene derivatives, furan derivatives, etc.) and aromatic amines (compounds having an aromatic amine skeleton).

[0435] The electron blocking layer is provided in contact with the light-emitting layer. The electron blocking layer is a layer containing a material that has hole-transporting properties and is capable of blocking electrons. Among the hole-transporting materials mentioned above, a material with electron-blocking properties can be used for the electron blocking layer.

[0436] Because electron-blocking layers possess hole-transporting properties, they can also be called hole-transporting layers. Furthermore, among hole-transporting layers, those that exhibit electron-blocking properties can also be called electron-blocking layers.

[0437] 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. As electron-transporting materials, in addition to metal complexes having a quinoline skeleton, metal complexes having a benzoquinoline skeleton, metal complexes having an oxazole skeleton, metal complexes having a thiazole skeleton, etc., materials with high electron transport capabilities such 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 can be used.

[0438] The hole-blocking layer is provided in contact with the light-emitting layer. The hole-blocking layer is a layer containing a material having electron-transporting properties and capable of blocking holes. Among the above electron-transporting materials, a material having hole-blocking properties can be used for the hole-blocking layer.

[0439] Since the hole-blocking layer has electron-transporting properties, it can also be called an electron-transporting layer. Also, among the electron-transporting layers, a layer having hole-blocking properties can be called a hole-blocking layer.

[0440] The electron-injecting layer is a layer that injects electrons from the cathode into the electron-transporting layer, and is a layer containing a material with high electron-injecting properties. As a material with high electron-injecting properties, an alkali metal, an alkaline earth metal, or a compound thereof can be used. As a material with high electron-injecting properties, a composite material containing an electron-transporting material and a donor material (electron-donating material) can also be used.

[0441] It is preferable that the difference between the LUMO level of the material with high electron-injecting properties and the work function value of the material used for the cathode is small (specifically, 0.5 eV or less).

[0442] For the electron-injecting layer, for example, lithium, cesium, ytterbium, lithium fluoride (LiF), cesium fluoride (CsF), calcium fluoride (CaF x , x is an arbitrary number), 8-(quinolinolato)lithium (abbreviation: Liq), 2-(2-pyridyl)phenolato lithium (abbreviation: LiPP), 2-(2-pyridyl)-3-pyridinolato lithium (abbreviation: LiPPy), 4-phenyl-2-(2-pyridyl)phenolato lithium (abbreviation: LiPPP), lithium oxide (LiO x ), cesium carbonate, etc., such alkali metals, alkaline earth metals, or compounds thereof can be used. Also, the electron-injecting layer may have a laminated structure of two or more layers. As the laminated structure, for example, a configuration in which lithium fluoride is used for the first layer and ytterbium is provided for the second layer can be mentioned.

[0443] 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.

[0444] 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.

[0445] 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.

[0446] When fabricating a tandem light-emitting device, a charge generation layer (also called an intermediate layer) is provided between the two light-emitting units. The charge generation layer has the function of injecting electrons into one of the two light-emitting units and holes into the other when a voltage is applied between a pair of electrodes. 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.

[0447] The charge generation layer preferably has a layer containing a material with high electron injection properties. 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, so that electrons generated in the charge generation region can be easily injected into the electron transport layer.

[0448] The electron injection buffer layer preferably contains an alkali metal or an alkaline earth metal, and can, for example, a compound of an alkali metal or an alkaline earth metal. Specifically, the electron injection buffer layer preferably has an inorganic compound containing an alkali metal and oxygen, or an inorganic compound containing an alkaline earth metal and oxygen, and more preferably has an inorganic compound containing lithium and oxygen (such as lithium oxide (Li2O)). In addition, any other material applicable to the electron injection layer can be suitably used for the electron injection buffer layer.

[0449] 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.

[0450] 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.

[0451] 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.

[0452] 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.

[0453] 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.

[0454] This embodiment can be combined with other embodiments as appropriate.

[0455] (Embodiment 5) In this embodiment, an electronic device according to one aspect of the present invention will be described with reference to Figures 29 to 31.

[0456] 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.

[0457] 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.

[0458] 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.

[0459] 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 that has either high resolution or high detail, or both, it becomes possible to further enhance the sense of presence and depth in personal electronic devices such as portable or home-use devices. Furthermore, there are no particular limitations on the screen ratio (aspect ratio) of the display device according to one embodiment of the present invention. For example, the display device can support various screen ratios such as 1:1 (square), 4:3, 16:9, and 16:10.

[0460] The electronic device of this embodiment may have sensors (including those with the function of measuring force, displacement, position, velocity, acceleration, angular velocity, rotational speed, distance, light, liquid, magnetism, temperature, chemical substances, sound, time, hardness, electric field, current, voltage, power, radiation, flow rate, humidity, gradient, vibration, odor, or infrared radiation).

[0461] 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.

[0462] Figures 29A to 29D illustrate an example of a wearable device that can be worn on the head. These wearable devices have at least one of the following functions: a function to display AR content, a function to display VR content, a function to display SR content, and a function to display MR content. By having an electronic device that has the function to display at least one of the following content types, such as AR, VR, SR, and MR, it is possible to enhance the user's sense of immersion.

[0463] The electronic device 700A shown in Figure 29A and the electronic device 700B shown in Figure 29B 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.

[0464] A display device according to one aspect 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.

[0465] 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.

[0466] 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.

[0467] 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.

[0468] Electronic devices 700A and 700B are equipped with batteries that can be charged wirelessly, wired, or both.

[0469] 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.

[0470] A touch sensor module can incorporate various types of touch sensors. For example, various methods such as capacitive, resistive, infrared, electromagnetic induction, surface acoustic wave, and optical sensors can be employed. In particular, it is preferable to apply a capacitive or optical sensor to the touch sensor module.

[0471] When using an optical touch sensor, a photoelectric conversion device (also called a photoelectric conversion element) can be used as the light-receiving device. The active layer of the photoelectric conversion device can be made of either an inorganic semiconductor or an organic semiconductor, or both.

[0472] The electronic device 800A shown in Figure 29C and the electronic device 800B shown in Figure 29D 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.

[0473] 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.

[0474] 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.

[0475] Electronic devices 800A and 800B can be described as electronic devices for VR. A user wearing either electronic device 800A or electronic device 800B can view the image displayed on the display unit 820 through the lens 832.

[0476] 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.

[0477] 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 29C and other figures as resembling the temples (or arms) of eyeglasses, it is not limited to this shape. The attachment portion 823 only needs to be wearable by the user; for example, it may be helmet-shaped or band-shaped.

[0478] 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.

[0479] 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. The detection unit can use, for example, an image sensor or a distance image sensor such as LiDAR (Light Detection and Ranging). 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.

[0480] 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.

[0481] Electronic devices 800A and 800B may each have input terminals. Cables can be connected to the input terminals to supply video signals from video output devices, etc., and power for charging batteries provided within the electronic devices.

[0482] 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 29A 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 29C has a function for transmitting information to the earphone 750 through its wireless communication function.

[0483] The electronic device may have an earphone section. The electronic device 700B shown in Figure 29B has an earphone section 727. For example, the earphone section 727 and the control section can be connected to each other by a wire. Some of the wiring connecting the earphone section 727 and the control section may be located inside the housing 721 or the mounting section 723.

[0484] Similarly, the electronic device 800B shown in Figure 29D 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.

[0485] 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.

[0486] Thus, in one embodiment of the present invention, electronic devices are preferably of the glasses type (electronic devices 700A and 700B, etc.) or the goggle type (electronic devices 800A and 800B, etc.).

[0487] An electronic device according to one aspect of the present invention can transmit information to earphones by wire or wireless means.

[0488] The electronic device 6500 shown in Figure 30A is a portable information terminal that can be used as a smartphone.

[0489] The electronic device 6500 includes a housing 6501, a display unit 6502, a power button 6503, a button 6504, a speaker 6505, a microphone 6506, a camera 6507, and a light source 6508, etc. The display unit 6502 has a touch panel function.

[0490] A display device according to one aspect of the present invention can be applied to the display unit 6502.

[0491] Figure 30B is a schematic cross-sectional view of the housing 6501, including the end on the microphone 6506 side.

[0492] 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.

[0493] 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).

[0494] 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.

[0495] A flexible display according to one embodiment of the present invention can be applied to the display panel 6511. This makes it possible to realize an extremely lightweight electronic device. Furthermore, because the display panel 6511 is extremely thin, it is possible to incorporate a large-capacity battery 6518 while keeping the thickness of the electronic device low. In addition, by folding back a part of the display panel 6511 and placing the connection part with the FPC 6515 on the back of the pixel area, it is possible to realize an electronic device with a narrow bezel.

[0496] Figure 30C shows an example of a television system. The television system 7100 has a display unit 7000 incorporated into a housing 7101. Here, the housing 7101 is shown supported by a stand 7103.

[0497] A display device according to one embodiment of the present invention can be applied to the display unit 7000.

[0498] The television device 7100 shown in Figure 30C 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.

[0499] 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.

[0500] Figure 30D 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.

[0501] A display device according to one embodiment of the present invention can be applied to the display unit 7000.

[0502] Figures 30E and 30F show examples of digital signage.

[0503] The digital signage 7300 shown in Figure 30E 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.

[0504] Figure 30F 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.

[0505] In Figures 30E and 30F, a display device according to one embodiment of the present invention can be applied to the display unit 7000.

[0506] 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.

[0507] 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.

[0508] As shown in Figures 30E and 30F, 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. In addition, the display on the display unit 7000 can be switched by operating the information terminal 7311 or information terminal 7411.

[0509] The digital signage 7300 or digital signage 7400 can also 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.

[0510] The electronic equipment shown in Figures 31A to 31G includes a housing 9000, a display unit 9001, a speaker 9003, operation keys 9005 (including a power switch or operation switch), connection terminals 9006, sensors 9007 (including functions for measuring force, displacement, position, velocity, acceleration, angular velocity, rotational speed, distance, light, liquid, magnetism, temperature, chemical substances, sound, time, hardness, electric field, current, voltage, power, radiation, flow rate, humidity, gradient, vibration, odor, or infrared radiation), a microphone 9008, etc.

[0511] The electronic devices shown in Figures 31A to 31G 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.

[0512] Details of the electronic equipment shown in Figures 31A to 31G will be explained below.

[0513] Figure 31A 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 31A 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 position where the information 9051 is displayed.

[0514] Figure 31B 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.

[0515] Figure 31C 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. The left side of the housing 9000 has operation keys 9005 as buttons for operation, and the bottom has connection terminals 9006.

[0516] Figure 31D 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.

[0517] Figures 31E to 31G are perspective views showing a foldable personal information terminal 9201. Figure 31E shows the personal information terminal 9201 in an unfolded state, Figure 31G shows it in a folded state, and Figure 31F shows a perspective view of the state in between, transitioning from one of Figures 31E or 31G 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.

[0518] This embodiment can be combined with other embodiments as appropriate. [Explanation of Symbols]

[0519] 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, 110a: Sub-pixel, 110B: Sub-pixel, 110b: Sub-pixel, 110c: Sub-pixel, 110d: Sub-pixel, 110e: Sub-pixel, 110G: Sub-pixel, 110R: Sub-pixel, 110: Pixel, 111a: Pixel electrode, 111b: Pixel electrode, 111c: Pixel electrode, 111: Pixel electrode, 112a: Conductive layer, 112b: Conductive layer, 112c: Conductive layer, 113: EL layer, 114: Common layer, 115: Common electrode, 116a: Conductive layer, 116aA: Conductive layer, 116aB: Conductive layer, 116aC: Conductive layer, 116b: Conductive layer, 116bA: Conductive layer, 116bB: Conductive layer, 116c: Conductive layer, 116fA: Conductive film, 116fB: Conductive film, 116fC: Conductive film, 116p: Conductive layer, 116q: Conductive layer, 116: Conductive layer, 117: Light-shielding layer, 119: Organic layer, 120: Substrate, 122: Resin layer, 123: Conductive layer, 124a: Pixel, 124b: Pixel, 126a: Conductive layer, 126b: Conductive layer, 126c: Conductive layer, 128: Layer, 130a: Light-emitting device S, 130B: Light-emitting device, 130b: Light-emitting device, 130c: Light-emitting device, 130G: Light-emitting device, 130R: Light-emitting device, 130: Light-emitting device, 131: Protective layer, 132B: Colored layer, 132G: Colored layer, 132R: Colored layer, 132: Colored layer, 133: Lens array, 134: Insulating layer, 140: Connection part, 142: Adhesive layer, 151: Substrate, 152: Substrate, 153: Insulating layer, 162: Display part, 164: Circuit, 165: Wiring, 166: Conductive layer, 168: Insulating layer, 172: FPC, 173: IC, 181A: Insulating layer, 181f: Insulating film, 181: Insulating layer, 183: gap, 187: opening, 190A: resist mask, 190Ba: resist mask, 190Bb: resist mask, 190Ca: resist mask, 190Cb: resist mask, 190Cc: resist mask, 190Cp: resist mask, 201: transistor, 204: connection, 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 section, 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: Insulation Layer, 329: insulating layer, 331: 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, 7 63c: Light-emitting unit, 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 :Pointing device, 7214:External connection port, 7300:Digital signage, 7301:Enclosure, 7303:Speaker, 7311:Information terminal, 7400:Digital signage, 7401:Column, 7411:Information terminal, 9000:Enclosure, 9001:Display unit, 9002:Camera, 9003:Speaker, 9005:Operation keys, 9006:Connection terminal, 9007:Sensor, 9008:Microphone, 9050:Icon, 9051:Information, 9052:Information, 9053:Information, 9054:Information, 9055:Hinge, 9101:Personal information terminal, 9102:Personal information terminal, 9103:Tablet terminal, 9200:Personal information terminal, 9201:Personal information terminal,

Claims

1. It comprises a first light-emitting device, a second light-emitting device, and an insulating layer. The first light-emitting device described above includes a first pixel electrode, a first EL layer, and a part of a common electrode. The second light-emitting device comprises a second pixel electrode, a second EL layer, and another part of the common electrode. The insulating layer has a region positioned between the first pixel electrode and the second pixel electrode. The insulating layer has an opening between the first pixel electrode and the second pixel electrode. The height of the upper surface of the highest region of the insulating layer is equal to or approximately equal to the height of the upper surface of the first pixel electrode and the height of the upper surface of the second pixel electrode. The insulating layer does not have a region located above the first pixel electrode, nor does it have a region located above the second pixel electrode. The first EL layer has a region located above the first pixel electrode, a region located above the insulating layer, and a region located inside the opening of the insulating layer. The second EL layer has a region located above the second pixel electrode, a region located above the insulating layer, and a region located inside the opening of the insulating layer. The common electrode has a region positioned above the first EL layer and a region positioned above the second EL layer. A display device in which the first EL layer is separated from the second EL layer.

2. It comprises a first light-emitting device, a second light-emitting device, and an insulating layer. The first light-emitting device described above includes a first pixel electrode, a first EL layer, and a part of a common electrode. The second light-emitting device comprises a second pixel electrode, a second EL layer, and another part of the common electrode. The insulating layer has a region positioned between the first pixel electrode and the second pixel electrode. The insulating layer has an opening between the first pixel electrode and the second pixel electrode. The opening has a void, The height of the upper surface of the highest region of the insulating layer is equal to or approximately equal to the height of the upper surface of the first pixel electrode and the height of the upper surface of the second pixel electrode. The insulating layer does not have a region located above the first pixel electrode, nor does it have a region located above the second pixel electrode. The first EL layer has a region located above the first pixel electrode, a region located above the insulating layer, and a region located inside the opening of the insulating layer. The second EL layer has a region located above the second pixel electrode, a region located above the insulating layer, and a region located inside the opening of the insulating layer. The common electrode has a region positioned above the first EL layer, a region positioned above the void, and a region positioned above the second EL layer. A display device in which the first EL layer is separated from the second EL layer.

3. It comprises a first light-emitting device, a second light-emitting device, and an insulating layer. The first light-emitting device described above includes a first pixel electrode, a first EL layer, and a part of a common electrode. The second light-emitting device comprises a second pixel electrode, a second EL layer, and another part of the common electrode. The insulating layer has a region positioned between the first pixel electrode and the second pixel electrode. The insulating layer has an opening between the first pixel electrode and the second pixel electrode. The opening has a void, The height of the upper surface of the highest region of the insulating layer is equal to or approximately equal to the height of the upper surface of the first pixel electrode and the height of the upper surface of the second pixel electrode. The insulating layer does not have a region located above the first pixel electrode, nor does it have a region located above the second pixel electrode. The first EL layer has a region located above the first pixel electrode, a region located above the insulating layer, and a region located inside the opening of the insulating layer. The second EL layer has a region located above the second pixel electrode, a region located above the insulating layer, and a region located inside the opening of the insulating layer. The common electrode has a region positioned above the first EL layer, a region positioned above the void, and a region positioned above the second EL layer. The aforementioned void contains one or more elements selected from air, nitrogen, oxygen, carbon dioxide, and Group 18 elements. A display device in which the first EL layer is separated from the second EL layer.

Images