Display device

Abstract

Provided is a display device with which high definition is easily achieved. Provided is a display device having high display quality. The display device comprises a substrate, a pixel electrode, an EL layer, an upper electrode, a partition wall, a wavelength conversion layer, and a color filter, wherein: the partition wall includes a first portion and a second portion which are provided to be spaced away from each other on the substrate; the pixel electrode is positioned on the substrate; the pixel electrode is positioned between the first portion and the second portion in plan view; the EL layer includes a light-emitting compound and is in contact with an upper surface of the pixel electrode; the upper electrode covers the upper surface of the EL layer; the wavelength conversion layer is positioned above the upper electrode; the color filter is positioned above the wavelength conversion layer; and the partition wall has an inverse tapered shape in a cross-sectional view and is conductive.

Description

display device

[0001] One aspect of the present invention relates to a display device.

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

[0003] In recent years, there has been a growing demand for higher resolution display panels. Devices requiring high-resolution display panels include, for example, smartphones, tablet devices, and notebook computers. Furthermore, stationary display devices such as television sets and monitors are also required to have higher resolutions. In addition, devices that require the highest level of resolution include, for example, devices for virtual reality (VR) or augmented reality (AR).

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

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

[0006] Furthermore, while a method using a metal mask is known for fabricating different organic EL elements, it has limitations in terms of aperture ratio, resolution, and substrate size. Patent document 2 describes a method for fabricating different organic EL elements using photolithography without using a metal mask.

[0007] Furthermore, display devices using quantum dots (QDs) as color conversion layers are beginning to become widespread. Quantum dots are small semiconductor nanoparticles with a diameter of only a few nanometers. Due to the quantum size effect, the band gap can be adjusted by the size of the particle, allowing incident light to be converted into light of different wavelengths depending on the particle size. Specifically, as the particle size decreases, it becomes possible to convert light into shorter wavelengths, and as the particle size increases, it becomes possible to convert light into longer wavelengths. Displays using quantum dots as color conversion layers utilize this property to change the particle size for each sub-pixel, thereby converting light of the same wavelength into light of different colors for each sub-pixel, enabling full-color display.

[0008] Japanese Patent Publication No. 2002-324673, International Publication No. 2023 / 285907

[0009] One aspect of the present invention aims to provide a display device that is easily made high-resolution, and a method for manufacturing the same. Another aspect of the present invention aims to provide a display device that combines high display quality and high resolution. Another aspect of the present invention aims to provide a display device with high contrast. Another aspect of the present invention aims to provide a highly reliable display device.

[0010] Furthermore, one aspect of the present invention aims to provide a display device having a novel configuration, or a method for manufacturing a display device. Another aspect of the present invention aims to provide a method for manufacturing the above-mentioned display device with a high yield. Another aspect of the present invention aims to mitigate at least one of the problems of the prior art.

[0011] Furthermore, one aspect of the present invention aims to achieve a full-color display device without processing organic compound layers containing a luminescent material between a pair of electrodes, thereby reducing the manufacturing process of the display device.

[0012] Furthermore, one aspect of the present invention aims to achieve full-color display even if the organic compound layers of each light-emitting device are identical, and to simplify the manufacturing process of high-definition display devices.

[0013] Furthermore, one aspect of the present invention aims to provide a light-emitting device with a long lifespan. Another aspect of the present invention aims to reduce leakage current between adjacent light-emitting devices. Another aspect of the present invention aims to reduce the resistance of wiring or electrodes that supply signals to a light-emitting device in a display device.

[0014] Furthermore, the description of these problems does not preclude the existence of other problems. Also, one aspect of the present invention does not need to solve all of these problems. Other problems can be naturally identified by those skilled in the art from the description in the specification, drawings, and claims, and it is possible to extract other problems from the description in the specification, drawings, and claims.

[0015] One aspect of the present invention is a display device comprising a substrate, a pixel electrode, an EL layer, an upper electrode, a partition wall, a wavelength conversion layer, and a color filter, wherein the partition wall has a first portion and a second portion provided spaced apart on the substrate, the pixel electrode is located on the substrate and is located between the first portion and the second portion in a plan view, the EL layer is in contact with the upper surface of the pixel electrode, the upper electrode is in contact with the upper surface of the EL layer and a part of the side surface of the partition wall, the wavelength conversion layer is located above the upper electrode, the color filter is located above the wavelength conversion layer, and the partition wall has an inverse tapered shape in a cross-sectional view and is conductive.

[0016] In the above embodiment, it is preferable that the EL layer has the function of emitting blue light, and the wavelength conversion layer has quantum dots or a fluorescent material.

[0017] In the above embodiment, it is preferable that the EL layer has the function of emitting blue light and green light, and the wavelength conversion layer has quantum dots or a fluorescent material.

[0018] In the above embodiment, it is preferable that the substrate has a first insulating layer, the first insulating layer has an end on the pixel electrode, the partition wall is located on the first insulating layer, and the angle between the contact surface of the partition wall and the first insulating layer and the side surface is 95 degrees or more and 150 degrees or less.

[0019] In the above embodiment, the EL layer comprises a first layer, a second layer, and a charge generation layer between the first and second layers, wherein the first layer contains a first luminescent compound, the second layer contains a first luminescent compound, and the charge generation layer comprises one selected from metals and metal compounds, a first organic compound, and a second organic compound different from the first organic compound, wherein the first organic compound preferably contains a phenanthroline skeleton.

[0020] In the above embodiment, the EL layer comprises a first layer, a second layer, and a charge generation layer between the first and second layers, wherein the first layer contains a first luminescent compound, the second layer contains a second luminescent compound, and the charge generation layer comprises one selected from metals and metal compounds, a first organic compound, and a second organic compound different from the first organic compound, wherein the first organic compound preferably contains a phenanthroline skeleton.

[0021] Furthermore, in the above embodiment, the metal preferably contains one or more selected from cesium, magnesium, calcium, ytterbium, and indium.

[0022] Furthermore, in the above embodiment, the metal compound preferably contains one or more selected from lithium oxide and cesium carbonate.

[0023] In the above embodiment, the second organic compound is preferably an organic compound having electron transport properties.

[0024] Furthermore, in the above embodiment, it is preferable that the substrate has a transistor, the transistor is located below the pixel electrode, and the transistor contains a metal oxide in the semiconductor layer where the channel is formed.

[0025] In the above embodiment, the metal oxide is preferably indium oxide.

[0026] Alternatively, one aspect of the present invention comprises a substrate, a first pixel electrode, a second pixel electrode, a first EL layer, a second EL layer, a first upper electrode, a second upper electrode, a partition wall, a first wavelength conversion layer, and a second wavelength conversion layer, wherein the first and second pixel electrodes are provided spaced apart on the substrate, the partition wall is located on the substrate, and in a plan view, the partition wall is located between the first and second pixel electrodes, the first EL layer contains a first luminescent compound and is in contact with the upper surface of the first pixel electrode, and the second The EL layer contains a first light-emitting compound and is in contact with the upper surface of the second pixel electrode; the first upper electrode covers the upper surface and edges of the first EL layer and is in contact with a part of the side surface of the partition wall; the second upper electrode covers the upper surface of the second EL layer; the first wavelength conversion layer is located above the first upper electrode; the second wavelength conversion layer is located above the second upper electrode; the first and second wavelength conversion layers are spaced apart; and the partition wall has an inverse tapered shape in cross-section and is conductive.

[0027] Furthermore, in the above embodiment, it is preferable that the first EL layer and the second EL layer each have the function of emitting blue light, the first wavelength conversion layer has the function of converting blue light to red light, and the second wavelength conversion layer has the function of converting blue light to green light.

[0028] Furthermore, in the above embodiment, it is preferable to have a separation layer, the separation layer being located between the first wavelength conversion layer and the second wavelength conversion layer, and being in contact with each of the first and second wavelength conversion layers.

[0029] Alternatively, one aspect of the present invention comprises a substrate, a first pixel on the substrate, a second pixel, and a partition wall, wherein the first pixel comprises a first pixel electrode, a first EL layer in contact with the upper surface of the first pixel electrode, a first upper electrode, and a wavelength conversion layer located above the first upper electrode, and the second pixel comprises a second pixel electrode, a second EL layer in contact with the upper surface of the second pixel electrode, and a second upper electrode, wherein the first EL layer and the second EL layer each have the function of emitting blue light, and the wavelength conversion layer has the function of converting blue light into light of a different color from blue, and the first pixel is blue The display device has the function of emitting light of different colors, the second pixel has the function of emitting blue light, the first pixel electrode and the second pixel electrode are provided spaced apart on the substrate, the partition wall is located on the substrate, the partition wall is located between the first pixel electrode and the second pixel electrode in a plan view, the first upper electrode covers the upper surface and edges of the first EL layer and is in contact with a part of the first side surface of the partition wall, the second upper electrode covers the upper surface and edges of the second EL layer and is in contact with a part of the second side surface of the partition wall, the partition wall has an inverse tapered shape in a cross-sectional view and is conductive.

[0030] According to one aspect of the present invention, a display device that can be easily made high-resolution and a method for manufacturing the same can be provided. Furthermore, according to one aspect of the present invention, a display device that combines high display quality and high resolution can be provided. Furthermore, according to one aspect of the present invention, a display device with high contrast can be provided. Moreover, according to one aspect of the present invention, a highly reliable display device can be provided.

[0031] Furthermore, according to one aspect of the present invention, a display device having a novel configuration can be provided. Furthermore, according to one aspect of the present invention, a method for manufacturing a novel display device can be provided. Furthermore, according to one aspect of the present invention, a method for manufacturing the above-mentioned display device with a high yield can be provided.

[0032] Furthermore, according to one aspect of the present invention, in a display device using a light-emitting device having an organic compound layer containing a light-emitting material between a pair of electrodes, a full-color display device can be realized without processing organic compound layers with different light-emitting colors for each light-emitting device, thereby reducing the manufacturing process of the display device.

[0033] Furthermore, according to one aspect of the present invention, full-color display can be achieved even if the organic compound layer of each light-emitting device is the same, and the manufacturing process of high-definition display devices can be simplified.

[0034] Furthermore, according to one aspect of the present invention, a light-emitting device with a long lifespan can be provided. Furthermore, according to one aspect of the present invention, leakage current between adjacent light-emitting devices can be reduced. Furthermore, according to one aspect of the present invention, the resistance of wiring or electrodes that supply signals to light-emitting devices can be reduced in a display device.

[0035] Furthermore, the description of these effects does not preclude the existence of other effects. Moreover, one aspect of the present invention does not necessarily have to possess all of these effects. Other effects can be extracted from the description in the specification, drawings, claims, etc.

[0036] Figures 1A and 1B show examples of the configuration of a display device. Figures 2A, 2B, and 2C show examples of the configuration of a display device. Figures 3A, 3B, and 3C show examples of the configuration of a display device. Figures 4A and 4B show examples of the configuration of a display device. Figures 5A and 5B show examples of the configuration of a display device. Figures 6A and 6B show examples of the configuration of a display device. Figures 7A, 7B, 7C, 7D, and 7E illustrate examples of methods for manufacturing a display device. Figures 8A, 8B, 8C, and 8D illustrate examples of methods for manufacturing a display device. Figures 9A and 9B illustrate examples of methods for manufacturing a display device. Figures 10A and 10B illustrate examples of methods for manufacturing a display device. Figures 11A, 11B, 11C, 11D, and 11E illustrate examples of methods for manufacturing a display device. Figures 12A and 12B show examples of the configuration of a display device manufacturing apparatus. Figure 13 shows an example of the configuration of a display device manufacturing apparatus. Figures 14A, 14B, and 14C show examples of the configuration of a display device manufacturing apparatus. Figures 15A and 15B show examples of the configuration of a display device manufacturing apparatus. Figure 16 shows an example of the configuration of a display device. Figure 17 shows an example of the configuration of a display device. Figure 18 shows an example of the configuration of a display device. Figures 19A and 19B show examples of the configuration of a display device. Figures 20A and 20B show examples of the configuration of a display device. Figure 21 shows an example of the configuration of a display device. Figure 22 shows an example of the configuration of a display device. Figure 23 shows an example of the configuration of a display device. Figures 24A, 24B, 24C, 24D, 24E, and 24F show examples of the configuration of a light-emitting device. Figures 25A, 25B, and 25C show examples of the configuration of a light-emitting device. Figures 26A, 26B, 26C, and 26D show examples of the configuration of electronic equipment. Figures 27A, 27B, 27C, 27D, 27E, and 27F show examples of electronic device configurations. Figures 28A, 28B, 28C, 28D, 28E, 28F, and 28G show examples of electronic device configurations. Figures 29A and 29B show examples of electronic device configurations. Figure 29C shows an electronic device in use.

[0037] The embodiments will be described below with reference to the drawings. However, it will be readily apparent to those skilled in the art that the embodiments can be implemented in many different ways, and their form and details can be modified in various ways without departing from the spirit and scope thereof. Accordingly, the present invention shall not be construed as being limited to the contents of the following embodiments.

[0038] In the invention described below, the same reference numerals are used in common across different drawings for identical parts or parts having similar functions, and repeated explanations are omitted. Furthermore, when referring to similar functions, the same hatching pattern may be used, and reference numerals may not be assigned.

[0039] In the figures described herein, the size of each component, the thickness of the layers, or the area may be exaggerated for clarity. Therefore, the scale is not necessarily limited to those figures.

[0040] Furthermore, ordinal numbers such as "the first," "the second," etc., used in this specification are added to avoid confusion of constituent elements and do not imply any numerical limitation.

[0041] In this specification, "approximately matching top surface shapes" means that at least a portion of the contours overlap between stacked layers. For example, this includes cases where the upper and lower layers are processed with the same mask pattern, or partially with the same mask pattern. However, strictly speaking, the contours may not overlap, and the upper layer may be located inside the lower layer, or the upper layer may be located outside the lower layer; in these cases, it may also be said that the "top surface shapes are approximately matching."

[0042] In this specification, the top surface shape of a component refers to the contour shape of that component in a plan view. A plan view refers to a view from the direction normal to the surface on which the component is formed, or to the surface of the support (e.g., substrate) on which the component is formed.

[0043] In the following, expressions indicating direction, such as "up" and "down," will generally be used in accordance with the orientation shown in the drawings. However, for the purpose of simplifying explanations, the direction referred to as "up" or "down" in the specification may not always coincide with that of the drawings. For example, when explaining the stacking order (or formation order) of a laminate, even if the side on which the laminate is provided (the surface to be formed, the support surface, the adhesive surface, the flat surface, etc.) is located above the laminate in the drawing, the surface to be formed may be described as "down" and the laminate side as "up."

[0044] Furthermore, in this specification, the terms "film" and "layer" are interchangeable. For example, the term "insulating layer" may be interchangeable with the term "insulating film."

[0045] In this specification, the term "EL layer" refers to a layer (also called a light-emitting layer) provided between a pair of electrodes of a light-emitting element and containing at least a light-emitting substance, or a laminate including a light-emitting layer.

[0046] Furthermore, in this specification, a display panel on which a connector such as an FPC (Flexible Printed Circuit) or TCP (Tape Carrier Package) is attached, or on which an IC is mounted on the board using a COG (Chip On Glass) method, may be referred to as a display panel module, display module, or simply a display panel.

[0047] (Embodiment 1) This embodiment describes an example of the configuration of a display device according to one aspect of the present invention, and an example of a method for manufacturing the same.

[0048] One aspect of the present invention is a display device having a light-emitting element (also called a light-emitting device).

[0049] A display device according to one aspect of the present invention has a plurality of first pixels, second pixels, and third pixels. Each pixel has an light-emitting element that emits light in the same wavelength range. The first pixel has a first wavelength conversion layer. The second pixel has a second wavelength conversion layer. Each pixel may also have a color filter (also called a coloring layer).

[0050] For example, the wavelength conversion layer can be made of quantum dots or fluorescent materials. For instance, the wavelength conversion layer can convert blue light into light with a longer wavelength (such as green or red). Therefore, a full-color display device can be realized by having a blue light-emitting element, a wavelength conversion layer that converts blue light into red light, and another wavelength conversion layer that converts blue light into green light.

[0051] A color filter has the function of transmitting light of a corresponding color and blocking (absorbing or reflecting) light of other colors. For example, a red color filter transmits red light and blocks (absorbs or reflects) light of other colors. Similarly, a green color filter transmits green light and blocks (absorbs or reflects) light of other colors. A blue color filter transmits blue light and blocks (absorbs or reflects) light of other colors.

[0052] For example, a resin material containing one or more of the following dispersed in it can be used as a color filter: metal, alloy, pigment, or dye.

[0053] In this specification, the visible light wavelength range is 360 nm to 830 nm. In this specification, the blue (B) wavelength range is 360 nm to 500 nm, and blue (B) light has at least one emission spectral peak in this wavelength range. The green (G) wavelength range is greater than 500 nm and less than or equal to 600 nm, and green (G) light has at least one emission spectral peak in this wavelength range. The red (R) wavelength range is greater than 600 nm and less than or equal to 760 nm, and red (R) light has at least one emission spectral peak in this wavelength range. In addition, the infrared (IR) wavelength range is from 760 nm to around 1 nm, and infrared (IR) light has at least one emission spectral peak in this wavelength range.

[0054] More specifically, for example, each pixel has an element that emits light including blue (B), and the first pixel has a wavelength conversion layer that converts the light emitted by the element to red (R) and a color filter that transmits red light and blocks (absorbs or reflects) light of other colors, and the second pixel has a wavelength conversion layer that converts the light emitted by the element to green (G) and a color filter that transmits green light and blocks (absorbs or reflects) light of other colors. With such a configuration, a full-color display device can be realized.

[0055] Furthermore, the third pixel can be configured to have a color filter that transmits blue light and blocks (absorbs or reflects) other colors of light. This can, for example, increase the chromaticity of blue light.

[0056] Furthermore, the light-emitting element can be configured to emit light with a wavelength shorter than blue. In this case, the third pixel can also be configured to have a wavelength conversion layer that converts the light emitted by the light-emitting element into blue light.

[0057] The first to third pixels each have a light-emitting element that emits light in the same wavelength range. Therefore, only one type of light-emitting element is required.

[0058] The light-emitting element can have an EL layer between a pair of electrodes. Here, one of the pair of electrodes is a pixel electrode to which a potential can be supplied individually. The other of the pair of electrodes is a common electrode to which a common potential is supplied between multiple light-emitting elements. As a result, by controlling the potential of the pixel electrode with a circuit composed of transistors or the like, the luminescence brightness of the light-emitting elements can be individually controlled, and an image can be displayed.

[0059] In a display device using a single type of light-emitting element and color filter, there is the advantage of being able to use the same materials for each light-emitting element. For example, only the pixel electrodes can be manufactured separately, while the EL layer and common electrodes can be made into a continuous layer across all light-emitting elements. This reduces manufacturing costs compared to cases where the EL layer and other components are manufactured separately. Furthermore, since there is no need to manufacture the EL layer separately using metal masks, an extremely high-definition display device can be realized.

[0060] On the other hand, by sharing the EL layer, leakage current can flow between adjacent light-emitting elements through the highly conductive film that makes up the EL layer, potentially causing unintended light emission. This can lead to a decrease in contrast and resolution, resulting in a decline in display quality, and may also increase power consumption. Therefore, even though high resolution is possible by eliminating the need for a metal mask, the distance between adjacent light-emitting elements must be increased to keep leakage current low. For these reasons, there are limitations to achieving high resolution and improving aperture ratio in a configuration that shares the EL layer.

[0061] One aspect of the present invention involves processing the EL layer into a fine pattern without using a shadow mask such as a metal mask. This allows the EL layer to be processed in an island-like manner for each light-emitting element, resulting in a configuration where leakage current between light-emitting elements is substantially eliminated. Therefore, it is possible to realize a display device with high resolution and a large aperture ratio, which has been difficult to achieve until now. Furthermore, the absence of leakage current enables the realization of a display device with extremely vivid colors, high contrast, and high display quality.

[0062] One aspect of the present invention involves providing a partition wall between two adjacent light-emitting elements (a first light-emitting element and a second light-emitting element) to divide the EL layer. The partition wall is a conductive structure with an inverse tapered shape. The partition wall can also be described as having a shape in which its upper part protrudes laterally more than its lower part. The partition wall is formed so as to be located between two adjacent pixel electrodes. Alternatively, the partition wall is provided so as to surround one pixel electrode. When the EL layer of the first light-emitting element is deposited, a step is created by the partition wall.

[0063] In this specification, "step breakage" refers to the phenomenon in which a layer, film, electrode, etc., is divided due to the shape of the surface on which it is formed (for example, a step or other difference in height).

[0064] Next, the upper electrode is formed by covering the EL layer and the partition wall. At this time, the upper electrode is formed by a deposition method that provides higher step coverage than the EL layer. This allows a configuration in which a part of the upper electrode covers the edge of the EL layer and is in contact with a part of the partition wall. Next, a protective layer is formed to cover the upper electrode and the partition wall. The protective layer is preferably formed by atomic layer deposition (ALD), which provides extremely high step coverage. This makes it possible to obtain a good protective film with few defects such as pinholes.

[0065] This method allows for the processing of the EL layer using photolithography, which enables microfabrication without the need for a metal mask. As a result, it is possible to manufacture display devices with extremely high resolution and a high aperture ratio.

[0066] Regarding the spacing between island-shaped EL layers, for example, it is difficult to reduce it to less than 10 μm using a formation method that uses a metal mask. However, with the above method, it is possible to narrow it to less than 3 μm, less than 2 μm, or even less than 1 μm. For example, by using an exposure apparatus for LSIs, the spacing can be narrowed to less than 500 nm, less than 200 nm, less than 100 nm, and even less than 50 nm. This significantly reduces the area of ​​the non-emitting region that may exist between two light-emitting elements, making it possible to bring the aperture ratio closer to 100%. For example, the aperture ratio can be 50% or more, 60% or more, 70% or more, 80% or more, and even 90% or more, and it is possible to achieve less than 100%.

[0067] Furthermore, the size of the EL layer itself can be made significantly smaller compared to when a metal mask is used. Also, for example, when a metal mask is used to create different EL layers, variations in thickness occur between the center and edges of the island-shaped EL layer, resulting in a smaller effective area usable as an emitting region relative to the total area of ​​the EL layer. On the other hand, with the above manufacturing method, island-shaped EL layers are formed by processing a film deposited to a uniform thickness, so the thickness can be made uniform, and even if the size of the EL layer is fine, almost the entire area can be used as an emitting region. Therefore, the above manufacturing method can achieve both high resolution and a high aperture ratio.

[0068] Thus, according to the above manufacturing method, a display device with integrated fine light-emitting elements can be realized. Therefore, there is no need to apply a special pixel arrangement method such as the PenTile method to artificially increase the resolution. Thus, a display device can be realized with a configuration in which each pixel has three colored light-emitting elements, and with a resolution of 500 ppi or more, 1000 ppi or more, 2000 ppi or more, 3000 ppi or more, 5000 ppi or more, and even 8000 ppi or more.

[0069] Below, we will explain more specific examples with reference to the diagrams.

[0070] [Configuration Example] Figure 1A shows a schematic top view of the display device 100. The display device 100 has multiple pixels 110R that emit red light, multiple pixels 110G that emit green light, and multiple pixels 110B that emit blue light. Each pixel has a light-emitting element. Pixels 110R and 110G each have a wavelength conversion layer and a color filter. In Figure 1A, the mutually orthogonal X and Y directions are indicated by arrows.

[0071] Pixels that exhibit different colors are sometimes called subpixels. For example, pixels 110R, 110G, and 110B may be represented together as a single pixel, and each of pixels 110R, 110G, and 110B may be represented as a subpixel.

[0072] Pixels 110R, 110G, and 110B are arranged in a matrix. Figure 1A shows a so-called stripe arrangement in which light-emitting elements of the same color are arranged in the Y direction. Note that the pixel arrangement method is not limited to this, and arrangement methods such as S-stripe arrangement, delta arrangement, zigzag arrangement may be applied, or a pentile arrangement may be used. Figure 1B shows an example in which an S-stripe arrangement is used.

[0073] It is preferable to use EL elements such as OLEDs (Organic Light Emitting Diodes) or QLEDs (Quantum-dot Light Emitting Diodes) as light-emitting elements arranged in pixels 110R, 110G, and 110B. Examples of light-emitting materials for EL elements 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 light-emitting materials for EL elements.

[0074] In this embodiment, when describing matters common to components distinguished by letters or numbers attached to their reference numerals (such as pixel electrode 111R and pixel electrode 111G), the reference numerals (such as pixel electrode 111) may be used without further explanation.

[0075] Furthermore, partition walls 120 are provided between each pixel. The partition walls 120 have a grid-like upper surface shape. It can also be said that the light-emitting elements of the pixels are located in the region surrounded by the partition walls 120.

[0076] As shown in Figure 1A, in a plan view, a gap is provided between the partition wall 120 and each pixel. Figure 1A shows the gap Sx in the X direction and the gap Sy in the Y direction between the light-emitting element of the pixel and the partition wall 120.

[0077] Figure 2A is a schematic cross-sectional view of the display device 100 corresponding to the cutting line A-B shown in Figure 1A. The display device 100 has a plurality of transistors 150, a pixel 110R, a pixel 110G, and a pixel 110B. Each pixel has a light-emitting element 110. Pixel 110R has a wavelength conversion layer 162R and a color filter 161R. Pixel 110G has a wavelength conversion layer 162G and a color filter 161G.

[0078] The wavelength conversion layer 162R has the function of converting the light emitted by the light-emitting element 110 into red (R). The color filter 161R has the function of transmitting red light and blocking (absorbing or reflecting) light of other colors. The wavelength conversion layer 162G has the function of converting the light emitted by the light-emitting element 110 into green (G). The color filter 161G has the function of transmitting green light and blocking (absorbing or reflecting) light of other colors.

[0079] As shown in Figure 1A, pixels 110R, 110G, and 110B are each located between the partition walls 120 in a plan view. Specifically, for example, as shown in Figure 1A, pixel 110R is located between the first portion 120_1 and the second portion 120_2 of the partition wall 120.

[0080] A transistor 150 is provided on a substrate 101. The transistor 150 has a semiconductor layer 151 on which a channel is formed, an insulating layer 152 that functions as a gate insulating layer, a conductive layer 153 that functions as a gate electrode, and a pair of conductive layers 154 that are in contact with the semiconductor layer 151 and function as source electrodes or drain electrodes. The conductive layers 154 are provided on an insulating layer 131 that covers the semiconductor layer 151, the insulating layer 152, and the conductive layers 153, and are in contact with the semiconductor layer 151 at an opening provided in the insulating layer 131.

[0081] It is preferable to use a metal oxide (also called an oxide semiconductor) that exhibits semiconductor properties as the semiconductor layer 151. As oxide semiconductors, oxide semiconductors such as indium oxide, indium gallium zinc oxide (In-Ga-Zn oxide, sometimes expressed as IGZO), indium gallium oxide (In-Ga oxide), and indium zinc oxide (In-Zn oxide) can be used. Alternatively, the semiconductor layer of the transistor may contain silicon. Examples of silicon include amorphous silicon and crystalline silicon (low-temperature polysilicon, single-crystal silicon, etc.).

[0082] In addition, metal oxides that can be used in the semiconductor layer 151 include tin oxide, zinc oxide, indium tin oxide, indium titanium oxide, indium tungsten oxide, indium gallium aluminum oxide, indium gallium tin oxide, gallium zinc oxide, aluminum zinc oxide, indium aluminum zinc oxide, indium tin zinc oxide, indium titanium zinc oxide, indium gallium tin zinc oxide, and indium gallium aluminum zinc oxide. Alternatively, silicon-containing indium tin oxide, gallium tin oxide, and aluminum tin oxide can also be used.

[0083] In this example, transistor 150 is shown as a so-called top-gate type transistor, where the gate electrode is located on the upper side of the semiconductor layer, but it is not limited to this. For example, a bottom-gate type transistor, where the gate electrode is located below the semiconductor layer, can also be used.

[0084] An insulating layer 132 is provided covering the conductive layer 154 and the insulating layer 131, and a light-emitting element 110 is provided on the insulating layer 132.

[0085] The light-emitting element 110 of pixel 110R has an EL layer 112 between the pixel electrode 111R and the upper electrode 113. Similarly, the light-emitting element 110 of pixel 110G has an EL layer 112 between the pixel electrode 111G and the upper electrode 113. The light-emitting element 110 of pixel 110B has an EL layer 112 between the pixel electrode 111B and the upper electrode 113.

[0086] Each pixel electrode 111 is provided on an insulating layer 132. In Figure 2A, a conductive layer 155 is provided on the insulating layer 131, and a conductive layer 156 is provided in the opening of the insulating layer 132 that overlaps with the conductive layer 155. The pixel electrode 111 is connected to the conductive layer 154 via the conductive layers 156 and 155. As a result, each pixel electrode 111 is connected to either the source electrode or the drain electrode of the transistor 150.

[0087] In a plan view, the pixel electrode 111R and EL layer 112 of the pixel 110R are located, for example, between the first portion 120_1 and the second portion 120_2 of the partition wall 120.

[0088] The light-emitting element 110 preferably emits blue light. Therefore, the EL layer 112 of the light-emitting element 110 preferably contains a light-emitting organic compound that emits blue light.

[0089] The wavelength conversion layer 162R, wavelength conversion layer 162G, and wavelength conversion layer 162B (hereinafter sometimes collectively referred to as wavelength conversion layer 162) can be made of a resin containing a wavelength conversion material.

[0090] The wavelength conversion layer 162 preferably contains a fluorescent material or quantum dots (QD). These materials allow for the conversion of the wavelength of light incident on the wavelength conversion layer 162. Quantum dots, in particular, have a narrow peak width in their emission spectrum, high conversion efficiency, and can produce light with high color purity. This enables the realization of a display device with high color reproducibility and high display quality.

[0091] The wavelength conversion layer 162 can be in the form of a resin in which a fluorescent material or quantum dots are dispersed.

[0092] The wavelength conversion layer 162 can be formed using droplet ejection (e.g., inkjet method), coating method, imprint method, various printing methods (screen printing, offset printing), etc. Alternatively, by using a photosensitive resin material as the organic resin, it may be formed by coating the organic resin using a spin coating method, etc., followed by exposure treatment and development treatment, and then processing into an arbitrary shape.

[0093] In addition to a layer containing a light-emitting organic compound (light-emitting layer), the EL layer 112 may also have one or more of the following: an electron injection layer, an electron transport layer, an electron blocking layer, a hole injection layer, a hole transport layer, and a hole blocking layer.

[0094] A conductive film that is transparent to visible light is used on either each pixel electrode 111 or the upper electrode 113, and a conductive film that is reflective is used on the other. By making each pixel electrode 111 transparent and the upper electrode 113 reflective, a bottom-emission type light-emitting element can be created. Conversely, by making each pixel electrode 111 reflective and the upper electrode 113 transparent, a top-emission type light-emitting element can be created. Furthermore, by making both each pixel electrode 111 and the upper electrode 113 transparent, a dual-emission type light-emitting element can also be created.

[0095] Furthermore, a protective layer 135 is provided to cover the upper electrode 113.

[0096] The protective layer 135 can be, for example, a single-layer structure or a multi-layer structure including at least an inorganic insulating film. Suitable inorganic insulating materials for the protective layer 135 include oxides or nitrides such as silicon oxide, silicon oxide nitride, silicon nitride, silicon oxide, aluminum oxide, aluminum oxide nitride, and hafnium oxide. Alternatively, semiconductor materials such as indium gallium oxide and indium gallium zinc oxide may be used as the protective layer 135. Aluminum oxide and silicon nitride are particularly preferred due to their high barrier properties against water.

[0097] Furthermore, a laminated film of an inorganic insulating film and an organic insulating film can also be used as the protective layer 135. For example, it is preferable to have a configuration in which an organic insulating film is sandwiched between a pair of inorganic insulating films.

[0098] An insulating layer 133 is provided to cover the ends of each pixel electrode 111. The portion of the pixel electrode 111 that is not covered by the insulating layer 133 functions as the light-emitting region of the light-emitting element 110. The ends of the insulating layer 133 are preferably tapered. The insulating layer 133 may be omitted if it is not needed.

[0099] In this specification, an object is said to have a tapered shape if the angle between the side surface of the object and the contact surface between the object and the surface to be formed (also called the taper angle) is greater than 0 degrees and less than 90 degrees, and the cross-sectional shape has a thickness that increases continuously from the end. On the other hand, an object is said to have an inverse tapered shape if the angle between the side surface of the object and the contact surface between the object and the surface to be formed is greater than 90 degrees and less than 180 degrees.

[0100] The insulating layer 133 preferably contains an organic resin. By using an organic resin as the insulating layer 133, adhesion to the EL layer 112 can be improved, and the manufacturing yield can be improved. In particular, when each EL layer is processed by etching, it is preferable to use an insulating layer 133 with high adhesion to each EL layer, as this reduces the problem of each EL layer peeling off after etching.

[0101] Furthermore, by using an organic resin for the insulating layer 133, its surface can be made flat or gently curved. This improves the coverage of the film formed on the insulating layer 133.

[0102] Examples of materials that can be used for the insulating layer 133 include acrylic resin, polyimide resin, epoxy resin, polyamide resin, polyimidoamide resin, siloxane resin, benzocyclobutene resin, phenol resin, and precursors of these resins.

[0103] Each EL layer 112 has a region in contact with the upper surface of the pixel electrode 111 and a region in contact with the surface of the insulating layer 133. The ends of each EL layer 112 are located on the insulating layer 133.

[0104] A partition wall 120 is provided on the insulating layer 133. The partition wall 120 is conductive and has an inverse tapered shape.

[0105] Furthermore, a layer 134 is provided on the protective layer 135, and a wavelength conversion layer 162R, a wavelength conversion layer 162G, a color filter 161R, and a color filter 161G are provided on the layer 134. A substrate 164 is provided on the color filter 161R and the color filter 161G.

[0106] The wavelength conversion layer 162R is provided so as to overlap with the light-emitting element 110 of the pixel 110R, and the color filter 161R is provided so as to overlap with the wavelength conversion layer 162R. Furthermore, the wavelength conversion layer 162G is provided so as to overlap with the light-emitting element 110 of the pixel 110G, and the color filter 161G is provided so as to overlap with the wavelength conversion layer 162G.

[0107] The transistor 150 and light-emitting element 110, provided on one side of the substrate 101, and the color filter 161R, color filter 161G, wavelength conversion layer 162R, and wavelength conversion layer 162G, provided on one side of the substrate 164, face each other with layer 134 in between. Layer 134 may, for example, have a resin layer that functions as an adhesive layer. By bonding the components provided on one side of the substrate 101 and the components provided on one side of the substrate 164 using this resin layer, the display device 100 can be manufactured.

[0108] It is preferable that layer 134 has the function of transmitting visible light.

[0109] Furthermore, layer 134 can also be configured as a laminate of two or more layers. For example, it can be a laminated structure of a layer that functions as a planarizing film and a resin layer that functions as an adhesive layer. Layer 134 can also be configured to have an inorganic insulating layer.

[0110] A separation layer 163 is provided between the adjacent wavelength conversion layers 162R and 162G. The separation layer 163 has the function of separating the two adjacent wavelength conversion layers. In addition, by providing the separation layer 163, it is possible to suppress the mixing of light converted by the wavelength conversion layer 162R and the light converted by the wavelength conversion layer 162G.

[0111] The separation layer 163 is located between two adjacent wavelength conversion layers 162 (for example, wavelength conversion layer 162R and wavelength conversion layer 162G). Preferably, the two adjacent wavelength conversion layers 162 are in contact with the separation layer 163 located between them.

[0112] The separation layer 163 can be formed using, for example, a resin. Furthermore, either an insulating material or a conductive material can be used as the separation layer 163. The separation layer 163 can also be configured to transmit visible light or to absorb visible light. Examples of resins applicable to the separation layer 163 include acrylic resins, polyimide resins, epoxy resins, polyamide resins, polyimidoamide resins, siloxane resins, benzocyclobutene resins, phenolic resins, and precursors of these resins.

[0113] A layer 137 can be provided between the layer on which the color filters 161R and 161G are provided and the layer on which the wavelength conversion layer 162R, wavelength conversion layer 162G, and separation layer 163 are provided. When the color filters 161R and 161G are formed on one side of the substrate 164, and then the surface is planarized by forming layer 137, and then the wavelength conversion layer 162R and wavelength conversion layer 162G are formed, the uniformity of the thickness of the wavelength conversion layer 162R and wavelength conversion layer 162G can be improved, for example, because the surface on which the wavelength conversion layer 162R and wavelength conversion layer 162G are formed is flat.

[0114] Furthermore, a layer 136 can be provided between the layer on which the wavelength conversion layer 162R, the wavelength conversion layer 162G, and the separation layer 163 are provided, and layer 134. Layer 136 can function as a protective layer for the wavelength conversion layer 162R and the wavelength conversion layer 162G.

[0115] It is preferable that layers 136 and 137 each have the function of transmitting visible light. Layers 136 and 137 can, for example, have an inorganic insulating layer. They can also be composed of resin or the like. They can also be composed of a porous material. As the inorganic insulating layer, for example, the inorganic insulating material listed as a material that can be used for the protective layer 135 can be used.

[0116] It is preferable that the color filters 161R, 161G, and 161B (hereinafter sometimes collectively referred to as color filter 161) are provided so that their ends overlap with the partition wall 120. The color filters 161 can be made of a resin material in which one or more of metals, alloys, pigments, or dyes are dispersed. The color filters 161 can be formed at desired positions by photolithography or inkjet printing, etc.

[0117] When forming the wavelength conversion layer 162 using methods such as droplet ejection and coating, the shape of the wavelength conversion layer 162 may change depending on its hydrophilicity with the surface to be formed. Figure 2B shows an example where the lower surface of the wavelength conversion layer 162 is concave. Note that in Figure 2B, the configuration of the layers below layer 134 in the display device 100 is omitted.

[0118] In the display device 100, the separation layer 163 can be omitted, as shown in Figure 2C.

[0119] Figure 3A shows a magnified view of pixel 110R, pixel 110G, the partition wall 120 located between them, and the vicinity thereof.

[0120] Each EL layer 112 has its end positioned on the insulating layer 133. Each upper electrode 113 covers the end of the EL layer 112 and is in contact with the upper surface of the insulating layer 133 and a portion of the side surface of the partition wall 120.

[0121] Furthermore, the ends of the upper electrode 113 and the protective layer 135 are located on the partition wall 120. In some cases, the upper electrode 113 is divided into a portion that covers the end of the EL layer 112 and is in contact with the partition wall 120, and a portion that is located on the partition wall 120. Additionally, an EL layer 112a is provided between the partition wall 120 and the upper electrode 113.

[0122] The upper electrodes 113 of the two pixels, separated by the partition wall 120, are in contact with the conductive partition wall 120, and can therefore be said to be connected via the partition wall 120. Therefore, even if the upper electrodes are separated near the side of the partition wall 120, they are supplied with a common potential via the partition wall 120. Furthermore, as shown in Figure 1A, the partition wall 120 is arranged in a grid pattern, weaving between the light-emitting elements 110, so the upper electrodes 113 of all the light-emitting elements 110 are connected via the partition wall 120. The partition wall 120 also functions as wiring that supplies potential to the upper electrodes 113 of each light-emitting element 110.

[0123] As shown in Figure 3A, the insulating layer 133 has its ends positioned on the pixel electrode 111R and the pixel electrode 111G, respectively. The gap Sx corresponds to the space between the end of the insulating layer 133 and the end of the most protruding part of the partition wall 120. The presence of this gap Sx allows the EL layer 112 to be formed such that, when the EL layer 112 is deposited, the stepped end of the EL layer 112, which is separated by the partition wall 120, is positioned on the insulating layer 133 and not on the pixel electrode 111. For example, if the end of the EL layer 112 is positioned on the pixel electrode 111, the upper electrode 113 covering the EL layer 112 may come into contact with the pixel electrode 111, potentially causing an electrical short circuit. Therefore, it is important to provide a gap Sx between the end of the insulating layer 133 and the partition wall 120 in order to ensure that the end of the EL layer 112 is positioned on the insulating layer 133. The same applies to the gap Sy.

[0124] Preferably, the height h of the partition wall 120 is greater than the thickness of the EL layer 112. Also, the taper angle θ of the partition wall 120 can be greater than 90 degrees and less than 180 degrees. The closer the taper angle θ is to 90 degrees, the easier it is for the partition wall 120 and the upper electrode 113 to come into contact when the upper electrode 113 is formed, but the gap between the end of the EL layer 112 and the partition wall 120 becomes smaller, and there is a risk that space cannot be secured for the upper electrode 113 and the partition wall 120 to come into contact. Also, the closer the taper angle θ is to 180 degrees, the easier it is for the EL layer 112 to break in steps, and the more difficult it becomes to bring the upper electrode 113 and the partition wall 120 into contact. For this reason, the taper angle θ should be, for example, 95 degrees or more and 150 degrees or less, preferably 100 degrees or more and 135 degrees or less.

[0125] The partition wall 120 can be made of various conductive materials. For example, metals, alloys, oxide conductive materials, nitride conductive materials, etc., can be used. For example, metallic materials such as gold, silver, platinum, magnesium, nickel, tungsten, chromium, molybdenum, iron, cobalt, copper, palladium, titanium, aluminum, yttrium, zirconium, and tantalum, or alloy materials containing such metallic materials, can be used.

[0126] Furthermore, it is preferable that the partition wall 120 contains an oxide conductive material containing indium. This is preferable because it can reduce the contact resistance with the upper electrode 113. For example, an oxide conductive material such as indium tin oxide can be used. Other materials that can be used include indium oxide, indium zinc oxide, indium titanium oxide, indium gallium zinc oxide, indium tin zinc oxide, indium titanium zinc oxide, and indium gallium tin zinc oxide. Alternatively, indium tin oxide containing silicon can also be used. In addition, an oxide conductive material that does not contain indium, such as zinc oxide, may be used.

[0127] This configuration allows for the physical separation of the EL layer between adjacent light-emitting elements, effectively eliminating leakage current through the EL layer compared to cases where the EL layers are in contact with each other or where a common EL layer is used between light-emitting elements. This prevents unintended light emission, resulting in a display device with high contrast and high display quality. Furthermore, since the EL layer 112 is covered by the upper electrode 113 and protective layer 135 within the region surrounded by the partition wall 120, it prevents the diffusion of impurities such as moisture into the EL layer 112, resulting in a highly reliable display device. Moreover, this configuration allows for the formation of the EL layer 112 without using a metal mask, and all processing of the layers constituting the light-emitting elements and their vicinity can be performed using photolithography, making it easier to achieve high resolution and high aperture ratio compared to cases where a metal mask is used.

[0128] Figure 3A and others show an example in which the partition wall 120 is provided on the insulating layer 133, but the insulating layer 133 does not necessarily have to be provided. Figure 3B shows an example in which the insulating layer 133 is not provided. In Figure 3B, the partition wall 120 is provided in contact with the upper surface of the insulating layer 132, similar to the pixel electrode 111. Also, the ends of each EL layer 112 are located on the insulating layer 132, and each upper electrode 113 is in contact with the insulating layer 132 and the partition wall 120.

[0129] Furthermore, in Figure 2A and other figures above, the height of the partition wall 120 is depicted as being greater than its width, but in reality, the cross-sectional width may be larger than the height. Figure 3C shows an example where the cross-sectional width of the partition wall 120 is greater than its height.

[0130] The above is an explanation of the example configuration.

[0131] Figure 2A shows an example in which the wavelength conversion layer 162 is provided on layer 134, but as shown in Figure 4A, the wavelength conversion layer 162 may be provided directly on the protective layer 135. In this case, it is preferable that the wavelength conversion layer 162 be provided so as to fill the recess on the upper surface of the protective layer 135 in the region surrounded by the partition wall 120.

[0132] Furthermore, the color filter 161 is provided on top of the wavelength conversion layer 162. The color filter 161 may be provided directly on the wavelength conversion layer 162, or, as shown in Figure 4A, a layer 137b may be provided in between.

[0133] It is preferable that layer 137b has the function of transmitting visible light. Layer 137b can, for example, have an inorganic insulating layer. It can also have a structure that includes a resin or the like. It can also have a structure that includes a porous material.

[0134] Figure 4B also shows an example where the upper surface of the wavelength conversion layer 162 is concave.

[0135] [Configuration Example 2] Figures 2A to 4B show an example configuration of a display device 100 suitable as a top-emission type light-emitting element. Figures 5A and 5B show an example configuration of a display device 100 suitable as a bottom-emission type light-emitting element.

[0136] Figure 5A shows an example configuration of a display device 100 in which a wavelength conversion layer 162 and a color filter 161 are provided between the transistor 150 and the light-emitting element 110.

[0137] In Figure 5A, the color filter 161 is located on the insulating layer 131, and the wavelength conversion layer 162 is located on the color filter 161. Layer 136 is provided on the wavelength conversion layer 162.

[0138] A layer 137c is provided so as to cover the color filter 161. The layer 137c is located between the color filter 161 and the wavelength conversion layer 162. In the display device 100, it is preferable that the layer 137c functions as an interlayer insulating layer. Therefore, it is preferable that the layer 137c is an insulating layer. The layer 137c may also contain one or both of an inorganic material and an organic material. For example, an organic resin can be used as the organic material.

[0139] An insulating layer 138 is provided on layer 136. However, if the flatness of the pixel electrode 111 is sufficient in the light-emitting region of the light-emitting element 110, the insulating layer 138 may not be provided.

[0140] The pixel electrode 111 of the light-emitting element 110 is connected to the conductive layer 154 via conductive layers provided in layers 137c, 136, 138, and 132. The display device 100 shown in Figure 5A has a conductive layer 155b on the insulating layer 138 and a conductive layer 156 provided in an opening in the insulating layer 132 that overlaps with the conductive layer 155b, and the pixel electrode 111 is connected to the conductive layer 155b via the conductive layer 156. In addition, the conductive layer 155a on the insulating layer 131 is connected to the conductive layer 154. Although not shown, the conductive layer 155b and the conductive layer 155a can also be connected via conductive layers provided in layers 137c, 136, and 138.

[0141] Figure 5B shows a display device configuration suitable for bottom-emission light-emitting elements, and differs from Figure 5A.

[0142] In Figure 5B, a transistor 150, a light-emitting element 110, etc., are provided on one side of the substrate 101. The other side of the substrate 101 faces a color filter 161, a wavelength conversion layer 162, etc., provided on the substrate 164 via layer 134.

[0143] [Configuration Example 3] The EL layer 112 of the light-emitting element 110 may also have two or more light-emitting organic compounds that emit light of different colors. For example, in addition to a light-emitting organic compound that emits blue light, a light-emitting organic compound that emits a second color of light different from blue can be used in combination. Specifically, for example, a light-emitting organic compound that emits blue light and a light-emitting organic compound that emits green light can be used in combination.

[0144] In such cases, for example, as shown in Figure 6A, it is preferable to provide a color filter 161B in the region of the pixel 110B that overlaps with the light-emitting element 110. The color filter 161B has the function of transmitting red light and blocking (absorbing or reflecting) light of other colors.

[0145] In pixel 110G, both the light obtained by converting the blue light emitted by the light-emitting element 110 to green light using the wavelength conversion layer 162, and the green light emitted by the light-emitting element 110 can be used. This makes it possible to increase the luminescence efficiency of pixel 110G that corresponds to wavelengths with high visual sensitivity, for example.

[0146] [Configuration Example 4] Alternatively, a wavelength conversion layer 162B can also be provided in the pixel 110B. For example, if the color exhibited by the pixel 110B is to be a color with a longer wavelength than the wavelength emitted by the light-emitting element 110, it is preferable to provide a wavelength conversion layer in the pixel 110B.

[0147] In such cases, for example, as shown in Figure 6B, it is preferable to provide a wavelength conversion layer 162B and a color filter 161B in the region overlapping with the light-emitting element 110 in the pixel 110B. The wavelength conversion layer 162B has the function of converting the light emitted by the light-emitting element into blue light.

[0148] [Wavelength Conversion Layer] The wavelength conversion layer 162 is sometimes called the color conversion layer. There are no particular limitations on the materials that make up the quantum dots of the wavelength conversion layer 162. Examples include Group 14 elements, Group 15 elements, Group 16 elements, compounds consisting of multiple Group 14 elements, compounds of elements belonging to Groups 4 to 14 and Group 16 elements, compounds of Group 2 elements and Group 16 elements, compounds of Group 13 elements and Group 15 elements, compounds of Group 13 elements and Group 17 elements, compounds of Group 14 elements and Group 15 elements, compounds of Group 11 elements and Group 17 elements, iron oxides, titanium oxides, chalcogenide spinels, and various semiconductor clusters.

[0149] Specifically, cadmium selenide, cadmium sulfide, cadmium telluride, zinc selenide, zinc oxide, zinc sulfide, zinc telluride, mercury sulfide, mercury selenide, mercury telluride, indium arsenide, indium phosphide, gallium arsenide, gallium phosphide, indium nitride, gallium nitride, indium antimonide, gallium antimonide, aluminum phosphide, aluminum arsenide, aluminum antimonide, lead selenide, lead telluride, lead sulfide, indium selenide, tel Indium sulfide, indium sulfide, gallium selenide, arsenic sulfide, arsenic selenide, arsenic telluride, antimony sulfide, antimony selenide, antimony telluride, bismuth sulfide, bismuth selenide, bismuth telluride, silicon, silicon carbide, germanium, tin, selenium, tellurium, boron, carbon, phosphorus, boron nitride, boron phosphide, boron arsenide, aluminum nitride, aluminum sulfide, barium sulfide, barium selenide, barium telluride, calcium sulfide, selenide Calcium, calcium telluride, beryllium sulfide, beryllium selenide, beryllium telluride, magnesium sulfide, magnesium selenide, germanium sulfide, germanium selenide, germanium telluride, tin sulfide, tin selenide, tin telluride, lead oxide, copper fluoride, copper chloride, copper bromide, copper iodide, copper oxide, copper selenide, nickel oxide, cobalt oxide, cobalt sulfide, iron oxide, iron sulfide, manganese oxide, molybdenum sulfide, vanadium oxide, tungsten oxide, tan oxide Examples include tal, titanium oxide, zirconium oxide, silicon nitride, germanium nitride, aluminum oxide, barium titanate, compounds of selenium, zinc, and cadmium, compounds of indium, arsenic, and phosphorus, compounds of cadmium, selenium, and sulfur, compounds of cadmium, selenium, and tellurium, compounds of indium, gallium, and arsenic, compounds of indium, gallium, and selenium, compounds of indium, selenium, and sulfur, compounds of copper, indium, and sulfur, and combinations thereof. In addition, so-called alloy-type quantum dots, whose composition is expressed in any ratio, may also be used.

[0150] Quantum dot structures include core type, core-shell type, and core-multishell type. Furthermore, because quantum dots have a high proportion of surface atoms, they are highly reactive and prone to aggregation. Therefore, it is preferable that a protective agent or protective group is attached to the surface of the quantum dots. This attachment of a protective agent or protective group prevents aggregation and improves solubility in solvents. It also reduces reactivity and improves electrical stability.

[0151] As the size of a quantum dot decreases, its band gap increases, so its size is adjusted appropriately to obtain light of a desired wavelength. As the size decreases, the emission of quantum dots shifts towards the blue side, that is, towards higher energy, so by changing the size of the quantum dots, the emission wavelength can be adjusted across the ultraviolet, visible, and infrared spectral wavelength ranges. The size (diameter) of a quantum dot is, for example, 0.5 nm to 20 nm, preferably 1 nm to 10 nm. Furthermore, the narrower the size distribution of quantum dots, the narrower the emission spectrum becomes, and the better the color purity of the emission can be obtained. The shape of the quantum dots is not particularly limited and may be spherical, rod-shaped, disc-shaped, or other shapes. A quantum rod, which is a rod-shaped quantum dot, has the function of exhibiting directional light.

[0152] The color conversion layer can be formed using methods such as droplet ejection (e.g., inkjet), coating, imprint, and various printing methods (screen printing, offset printing). Alternatively, a color conversion film such as a quantum dot film may be used.

[0153] When processing the film that will become the color conversion layer, it is preferable to use photolithography. Photolithography methods include a method in which a resist mask is formed on the thin film to be processed, the thin film is processed by etching or the like, and the resist mask is removed, and a method in which a photosensitive thin film is formed, and then exposed and developed to process the thin film into the desired shape. For example, an island-shaped color conversion layer can be formed by forming a thin film using a material in which quantum dots are mixed with photoresist, and then processing the thin film using photolithography.

[0154] Furthermore, in a display device according to one embodiment of the present invention, it is preferable to provide a separation layer 163 having an opening on a substrate and to provide a wavelength conversion layer 162 within the opening. The separation layer 163 can be formed using an organic resin film such as acrylic resin, polyamide resin, or epoxy resin, an inorganic insulating film, or an organic polysiloxane. It is particularly preferable to use a photosensitive material and to form it so that the side walls of the opening are inclined surfaces with a continuous curvature. By providing the separation layer 163, the color conversion layers of each color can be separated, thereby preventing color mixing. Therefore, a display device with high display quality can be provided. The separation layer 163 has the function of separating the wavelength conversion layers 162 of each color.

[0155] However, quantum dots have the drawback of being susceptible to degradation due to the intrusion of impurities such as oxygen. When quantum dots degrade, the light emission intensity of the pixels decreases, and the display quality of the display device deteriorates. Therefore, in display devices that use quantum dots as a color conversion layer, it is necessary to prevent impurities such as oxygen from entering from around the color conversion layer and to prevent the degradation of the quantum dots. In one embodiment of the present invention, by providing layers 136 and 137, the intrusion of impurities into the wavelength conversion layer 162 can be prevented.

[0156] [EL layer] The light-emitting layer of the EL layer 112 is a layer containing a light-emitting central material. It is also preferable that it further contains a host material.

[0157] The luminescent central material may be a fluorescent material, a phosphorescent material, a thermally activated delayed fluorescence (TADF) material, or any other luminescent material.

[0158] In one embodiment of the present invention, the following are examples of materials that can be used as fluorescent luminescent materials in the light-emitting layer. Other fluorescent luminescent materials can also be used.

[0159] 5,6-bis[4-(10-phenyl-9-antryl)phenyl]-2,2'-bipyridine (abbreviation: PAPP2BPy), 5,6-bis[4'-(10-phenyl-9-antryl)biphenyl-4-yl]-2,2'-bipyridine (abbreviation: PAPP2BPy), N,N'-diphenyl-N,N'-bis[4-(9-phenyl-9H-fluoren-9-yl)phenyl]pyrene-1,6-diamine (abbreviation: 1,6FLPAPrn), N,N'-bis(3-methylphenyl)-N,N'-bis[3-(9-phenyl-9H- Fluoren-9-yl)phenyl]pyrene-1,6-diamine (abbreviation: 1,6mMemFLPAPrn), N,N'-bis[4-(9H-carbazole-9-yl)phenyl]-N,N'-diphenylstilbene-4,4'-diamine (abbreviation: YGA2S), 4-(9H-carbazole-9-yl)-4'-(10-phenyl-9-antryl)triphenylamine (abbreviation: YGAPA), 4-(9H-carbazole-9-yl)-4'-(9,10-diphenyl-2-antryl)triphenylamine (abbreviation: 2YGA PPA), N,9-diphenyl-N-[4-(10-phenyl-9-anthryl)phenyl]-9H-carbazole-3-amine (abbreviation: PCAPA), perylene, 2,5,8,11-tetra-tert-butylperylene (abbreviation: TBP), 4-(10-phenyl-9-anthryl)-4'-(9-phenyl-9H-carbazole-3-yl)triphenylamine (abbreviation: PCBAPA), N,N''-(2-tert-butylanthracene-9,10-diyldi-4,1-phenylene)bis(N,N',N'-triphenyl Nyl-1,4-phenylenediamine) (abbreviation: DPABPA), N,9-diphenyl-N-[4-(9,10-diphenyl-2-antryl)phenyl]-9H-carbazole-3-amine (abbreviation: 2PCAPPA), N,N'-diphenyl-N,N'-(1,6-pyrene-diyl)bis[(6-phenylbenzo[b]naphtho[1,2-d]furan)-8-amine] (abbreviation: 1,6BnfAPrn-03), N,N'-diphenyl-N,N'-bis(9-phenyl-9H-carbazole-2-yl)naphtho[2,3-b;Materials that exhibit blue luminescence, such as 6,7-b']bisbenzofuran-3,10-diamine (abbreviation: 3,10PCA2Nbf(IV)-02), 3,10-bis[N-(dibenzofuran-3-yl)-N-phenylamino]naphtho[2,3-b;6,7-b']bisbenzofuran (abbreviation: 3,10FrA2Nbf(IV)-02), N-[4-(9,10-diphenyl-2-antryl)phenyl]- N,N',N'-triphenyl-1,4-phenylenediamine (abbreviation: 2DPAPPA), N,N,N',N',N'',N'',N''',N'''-octaphenyldibenzo[g,p]chrysene-2,7,10,15-tetraamine (abbreviation: DBC1), coumarin 30, N-(9,10-diphenyl-2-anthryl)-N,9-diphenyl-9H-carbazole-3-amine (abbreviation: 2PCAP) A), N-[9,10-bis(biphenyl-2-yl)-2-anthryl]-N,9-diphenyl-9H-carbazole-3-amine (abbreviation: 2PCABPhA), N-(9,10-diphenyl-2-anthryl)-N,N',N'-triphenyl-1,4-phenylenediamine (abbreviation: 2DPAPA), N-[9,10-bis(biphenyl-2-yl)-2-anthryl]-N,N',N'-trif Examples include materials that exhibit green luminescence, such as phenyl-1,4-phenylenediamine (abbreviated as 2DPABPhA), 9,10-bis(biphenyl-2-yl)-N-[4-(9H-carbazole-9-yl)phenyl]-N-phenylanthracene-2-amine (abbreviated as 2YGABPhA), N,N,9-triphenylanthracene-9-amine (abbreviated as DPhAPhA), and coumarin 545T. In particular, condensed aromatic diamine compounds, such as pyrenediamine compounds like 1,6FLPAAPrn, 1,6mMemFLPAAPrn, and 1,6BnfAPrn-03, are preferred due to their high hole-trapping properties and excellent luminescence efficiency or reliability.

[0160] Also, 5,9-diphenyl-5H,9H-[1,4]benzazabolino[2,3,4-kl]phenazavolin (abbreviation: DABNA-1), 9-(biphenyl-3-yl)-N,N,5,11-tetraphenyl-5H,9H-[1,4]benzazabolino[2,3,4-kl]phenazavolin-3-amine (abbreviation: DABNA-2), 2,12-di(tert-butyl)-5,9-di(4-tert-butylphenyl)-N,N-diphenyl-5H,9H-[1,4]benzazabolino[2,3,4-kl]phenazavolin- 7-amine (abbreviation: DPhA-tBu4DABNA), 2,12-di(tert-butyl)-N,N,5,9-tetra(4-tert-butylphenyl)-5H,9H-[1,4]benzazabolino[2,3,4-kl]phenazavolin-7-amine (abbreviation: tBuDPhA-tBu4DABNA), 2,12-di(tert-butyl)-5,9-di(4-tert-butylphenyl)-7-methyl-5H,9H-[1,4]benzazabolino[2,3,4-kl]phenazavolin (abbreviation: Me-tBu4DABNA), N ７ , N ７ , N １３ , N １３ Condensed heteroaromatic compounds containing nitrogen and boron, such as 5,9,11,15-octaphenyl-5H,9H,11H,15H-[1,4]benzazabolino[2,3,4-kl][1,4]benzazabolino[4',3',2':4,5][1,4]benzazabolino[3,2-b]phenazabolin-7,13-diamine (abbreviation: ν-DABNA) and 2-(4-tert-butylphenyl)benz[5,6]indro[3,2,1-jk]benzo[b]carbazole (abbreviation: tBuPBibc), particularly compounds having a diazaboranaphtho-anthracene skeleton, can be suitably used because they produce blue emission with a narrow emission spectrum and good color purity.

[0161] In addition to these, compounds having an indole skeleton such as 9,10,11-tris[3,6-bis(1,1-dimethylethyl)-9H-carbazol-9-yl]-2,5,15,18-tetrakis(1,1-dimethylethyl)indolo[3,2,1-de]indolo[3',2',1':8,1][1,4]benzazaborino[2,3,4-kl]phenazaborine (abbreviation: BBCz-G), 9,11-bis[3,6-bis(1,1-dimethylethyl)-9H-carbazol-9-yl]-2,5,15,18-tetrakis(1,1-dimethylethyl)indolo[3,2,1-de]indolo[3',2',1':8,1][1,4]benzazaborino[2,3,4-kl]phenazaborine (abbreviation: BBCz-Y) can be suitably used.

[0162] In the light-emitting layer, a phosphorescent substance that can be used as a light-emitting center substance is preferably a metal complex, particularly an iridium complex or a platinum complex, and examples thereof include the following substances.

[0163] Tris{2-[5-(2-methylphenyl)-4-(2,6-dimethylphenyl)-4H-1,2,4-triazol-3-yl-κN2]phenyl-κC}iridium(III) (abbreviation: [Ir(mpptz-dmp) ３ ), tris(5-methyl-3,4-diphenyl-4H-1,2,4-triazolato)iridium(III) (abbreviation: [Ir(Mptz) ３ ), an organometallic iridium complex having a 4H-triazole skeleton, tris[3-methyl-1-(2-methylphenyl)-5-phenyl-1H-1,2,4-triazolato]iridium(III) (abbreviation: [Ir(Mptz1-mp) ３ ), tris(1-methyl-5-phenyl-3-propyl-1H-1,2,4-triazolato)iridium(III) (abbreviation: [Ir(Prptz1-Me) ３ ), an organometallic iridium complex having a 1H-triazole skeleton, fac-tris[1-(2,6-diisopropylphenyl)-2-phenyl-1H-imidazole]iridium(III) (abbreviation: [Ir(iPrpim) ３]), Tris[3-(2,6-dimethylphenyl)-7-methylimidazo[1,2-f]phenanthridine]iridium(III) (abbreviation: [Ir(dmpimpt-Me) ３ ]), organometallic iridium complexes having an imidazole skeleton such as tris(2-{1-[2,6-bis(1-methylethyl)phenyl]-1H-imidazole-2-yl-κN3}-4-cyanophenyl-κC) iridium(III) (abbreviation: CNImIr), tris[(6-tert-butyl-3-phenyl-2H-imidazol[4,5-b]pyrazine-1-yl-κC2)phenyl-κC] iridium(III) (abbreviation: [Ir(cb) ３ Organometallic complexes having a benzimidazolidene skeleton such as ]), bis[2-(4',6'-difluorophenyl)pyridinato-N,C ２’ Iridium(III) tetrakis(1-pyrazolyl) borate (abbreviation: FIr6), bis[2-(4',6'-difluorophenyl)pyridinate-N,C ２’ Iridium(III) picolinate (abbreviation: FIrpic), bis{2-[3',5'-bis(trifluoromethyl)phenyl]pyridinate-N,C ２’ Iridium (III) picolinate (abbreviation: [Ir(CF) ３ ppy) ２ (pic)]), bis[2-(4',6'-difluorophenyl)pyridinate-N,C ２’ Examples include organometallic iridium complexes with phenylpyridine derivatives having electron-withdrawing groups, such as iridium(III) acetylacetonate (abbreviated as FIracac), and platinum complexes such as (2-{3-[3-(3,5-di-tert-butylphenyl)benzimidazole-1-yl-2-ylidene-κC2]phenoxy-κC2}-9-(4-tert-butyl-2-pyridinyl-κN)carbazole-2,1-diyl-κC1)platinum(II) (abbreviated as PtON-TBBI). These compounds exhibit phosphorescence and have emission peaks in the wavelength range from 450 nm to 520 nm. Compounds in which some of the hydrogen atoms in these compounds are replaced with deuterium can also be used.

[0164] Also, tris(4-methyl-6-phenylpyrimidinato)iridium(III) (abbreviation: [Ir(mppm) ３ ]), Tris(4-t-butyl-6-phenylpyrimidinato)iridium(III) (abbreviation: [Ir(tBuppm) ３ ]), (acetylacetonato)bis(6-methyl-4-phenylpyrimidinato)iridium(III) (abbreviation: [Ir(mppm) ２ (acac)), (acetylacetonato)bis(6-tert-butyl-4-phenylpyrimidinato)iridium(III) (abbreviation: [Ir(tBuppm) ２ (acac)), (acetylacetonate)bis[6-(2-norbornyl)-4-phenylpyrimidinato]iridium(III) (abbreviation: [Ir(nbppm) ２ (acac)), (acetylacetonato)bis[5-methyl-6-(2-methylphenyl)-4-phenylpyrimidinato]iridium(III) (abbreviation: [Ir(mpmpppm) ２ (acac)), (acetylacetonato)bis(4,6-diphenylpyrimidinato)iridium(III) (abbreviation: [Ir(dppm) ２ Organometallic iridium complexes having a pyrimidine skeleton such as (acac) (acetylacetonato)bis(3,5-dimethyl-2-phenylpyradinato)iridium(III) (abbreviation: [Ir(mppr-Me) ２ (acac)), (acetylacetonato)bis(5-isopropyl-3-methyl-2-phenylpyradinato)iridium(III) (abbreviation: [Ir(mppr-iPr) ２ Organometallic iridium complexes having a pyrazine skeleton such as (acac), Tris(2-phenylpyridinato-N,C) ２’ Iridium (III) (abbreviation: [Ir(ppy) ３ ]), bis(2-phenylpyridinate-N,C ２’ Iridium (III) acetylacetonate (abbreviation: [Ir(ppy) ２ (acac)), bis(benzo[h]quinolinate)iridium(III)acetylacetonate (abbreviation: [Ir(bzq) ２(acac)), Tris(benzo[h]quinolinate) Iridium(III) (abbreviation: [Ir(bzq) ３ ]), Tris(2-phenylquinolinato-N,C) ２’ Iridium (III) (abbreviation: [Ir(pq) ３ ]), bis(2-phenylquinolinato-N,C ２’ Iridium(III) acetylacetonate (abbreviation: [Ir(pq) ２ (acac)]), [2-d3-methyl-8-(2-pyridinyl-κN)benzofl[2,3-b]pyridine-κC]bis[2-(5-d ３ [Methyl-2-pyridinyl-κN2)phenyl-κC]iridium(III) (abbreviation: Ir(5mppy-d) ３ ) ２ (mbfpypy-d ３ )), {2-(methyl-d ３ )-8-[4-(1-methylethyl-1-d)-2-pyridinyl-κN]benzofl[2,3-b]pyridin-7-yl-κC]bis{5-(methyl-d ３ )-2-[5-(methyl-d ３ )-2-pyridinyl-κN]phenyl-κC}iridium(III) (abbreviation: Ir(5mtpy-d6) ２ (mbfpypy-iPr-d ４ )), [2-(methyl-d ３ )-8-(2-pyridinyl-κN)benzofloxacin[2,3-b]pyridinyl-κC]bis[2-(2-pyridinyl-κN)phenyl-κC]iridium(III) (abbreviation: Ir(ppy) ２ (mbfpypy-d ３ )), [2-(4-methyl-5-phenyl-2-pyridinyl-κN)phenyl-κC]bis[2-(2-pyridinyl-κN)phenyl-κC]iridium(III) (abbreviation: Ir(ppy) ２ (mdppy)), [2-(4-d ３ [methyl-5-phenyl-2-pyridinyl-κN2)phenyl-κC]bis[2-(5-d ３ [Iridium (III) (abbreviation: [Ir(5mppy-d)])(methyl-2-pyridinyl-κN2)phenyl-κC) ３ )2(mdppy-d３ ) )]), [2-methyl-8-(2-pyridinyl-κN)benzofl[2,3-b]pyridine-κC]bis[2-(2-pyridinyl-κN)phenyl-κC]iridium(III) (abbreviation: [Ir(ppy) ２ (mbfpypy))]), [2-(4-methyl-5-phenyl-2-pyridinyl-κN)phenyl-κC]bis[2-(2-pyridinyl-κN)phenyl-κC]iridium (abbreviation: [Ir(ppy) ２ (mdppy)]), Tris{2-[5-(methyl-d3)-4-phenyl-2-pyridinyl-κN]phenyl-κC}Iridium(III) (abbreviation: Ir(5m4dppy-d ３ ) ３ In addition to organometallic iridium complexes with a pyridine skeleton such as tris(acetylacetonato)(monophenanthroline)terbium(III) (abbreviation: [Tb(acac) ３ Rare earth metal complexes such as (Phen) (2-{1-(5-tert-butylbiphenyl-2-yl)-4-[3-tert-butyl-5-(4-phenyl-2-pyridinyl-κN)phenyl-κC6]-2-benzimidazolyl-κN3}-4,6-di-tert-butylphenolate-κO)platinum(II) (abbreviation: Pt(tBudpppymmtBubiz-tBubp) Examples of organometallic platinum complexes include [2-(4-(3,5-di-tert-butylphenyl)-6-{3-[4-(5'-tert-butyl[1,1':3',1''-terphenyl]-2'-yl)-2-pyridinyl-κN]phenyl-κC2}-2-pyridinyl-κN)phenolato-κO]platinum(II) (abbreviation: Pt(4tButpppypyp-mmtBup)). These compounds mainly exhibit phosphorescence with a green hue and have emission peaks in the wavelength range from 500 nm to 600 nm. Organometallic iridium complexes with a pyrimidine skeleton are particularly preferred due to their outstanding reliability and luminescence efficiency. Compounds in which some of the hydrogen atoms are replaced with deuterium can also be used.

[0165] In addition to the phosphorescent compounds described above, other known phosphorescent compounds may be selected and used.

[0166] As TADF materials, fullerenes and their derivatives, acridines and their derivatives, eosin derivatives, etc., can be used. Also, metal-containing porphyrins containing magnesium (Mg), zinc (Zn), cadmium (Cd), tin (Sn), platinum (Pt), indium (In), or palladium (Pd) can be used. As such metal-containing porphyrins, for example, the protoporphyrin-tin fluoride complex (SnF) shown in the following structural formula is used. ２ (Proto IX)), Mesoporphyrin-Tin Fluoride Complex (SnF ２ (Meso IX), hematoporphyrin-tin fluoride complex (SnF ２ (Hemato IX), coproporphyrin tetramethyl ester-tin fluoride complex (SnF ２ (Copro III-4Me)), Octaethylporphyrin-Tin Fluoride Complex (SnF ２ (OEP)), Ethioporphyrin-Tin Fluoride Complex (SnF ２ (Etio I)), Octaethylporphyrin-Platinum Chloride Complex (PtCl ２ OEP (Open Economic Programme) and others can also be mentioned.

[0167]

[0168] Furthermore, the following structural formulas represent 2-(biphenyl-4-yl)-4,6-bis(12-phenylindoro[2,3-a]carbazole-11-yl)-1,3,5-triazine (abbreviation: PIC-TRZ), 9-(4,6-diphenyl-1,3,5-triazine-2-yl)-9'-phenyl-9H,9'H-3,3'-bicarbazole (abbreviation: PCCzTZn), 2-{4-[3-(N-phenyl-9H-carbazole-3-yl)-9H-carbazole-9-yl]phenyl}-4,6-diphenyl-1,3,5-triazine (abbreviation: PCCzPTZn), 2-[4-(10H-phenoxazine-10-yl)phenyl]-4,6-diphenyl-1,3,5-triazine (abbreviation: PCCzPTZn), Heterocyclic compounds having one or both of a π-electron-rich heteroaromatic ring and a π-electron-deficient heteroaromatic ring can also be used, such as PXZ-TRZ), 3-[4-(5-phenyl-5,10-dihydrophenadin-10-yl)phenyl]-4,5-diphenyl-1,2,4-triazole (abbreviated as PPZ-3TPT), 3-(9,9-dimethyl-9H-acridine-10-yl)-9H-xanthene-9-one (abbreviated as ACRXTN), bis[4-(9,9-dimethyl-9,10-dihydroacridine)phenyl]sulfone (abbreviated as DMAC-DPS), and 10-phenyl-10H,10'H-spiro[acridine-9,9'-anthracene]-10'-one (abbreviated as ACRSA). The heterocyclic compound is preferred because it has both a π-electron-excess heteroaromatic ring and a π-electron-deficient heteroaromatic ring, resulting in high electron transport and hole transport properties. Among the skeletons having a π-electron-deficient heteroaromatic ring, the pyridine skeleton, diazine skeleton (pyrimidine skeleton, pyrazine skeleton, pyridazine skeleton), and triazine skeleton are preferred because they are stable and reliable. In particular, the benzoflopyrimidine skeleton, benzothienopyrimidine skeleton, benzoflopyrazine skeleton, and benzothienopyrazine skeleton are preferred because they have high acceptability and are reliable. Furthermore, among the skeletons having a π-electron-excess heteroaromatic ring, the acridine skeleton, phenoxazine skeleton, phenothiazine skeleton, furan skeleton, thiophene skeleton, and pyrrole skeleton are preferred because they are stable and reliable, and therefore it is preferable to have at least one of these skeletons.Furthermore, a dibenzofuran skeleton is preferred as the furan skeleton, and a dibenzothiophene skeleton is preferred as the thiophene skeleton. In addition, as the pyrrole skeleton, indole skeleton, carbazole skeleton, indrocarbazole skeleton, bicarbazole skeleton, and 3-(9-phenyl-9H-carbazole-3-yl)-9H-carbazole skeleton are particularly preferred. Substances in which a π-electron-rich heteroaromatic ring and a π-electron-deficient heteroaromatic ring are directly bonded are particularly preferred because both the electron-donating and electron-accepting properties of the π-electron-rich heteroaromatic ring are strengthened, and the energy difference between the S1 and T1 levels is reduced, thus efficiently obtaining thermally activated delayed fluorescence. In addition, an aromatic ring to which an electron-withdrawing group such as a cyano group is bonded may be used instead of the π-electron-deficient heteroaromatic ring. Furthermore, aromatic amine skeletons, phenazine skeletons, etc., can be used as the π-electron-rich skeleton. Furthermore, as π-electron-deficient skeletons, xanthene skeletons, thioxanthene dioxide skeletons, oxadiazole skeletons, triazole skeletons, imidazole skeletons, anthraquinone skeletons, boron-containing skeletons such as phenylborane and volanthrene, aromatic rings having a nitrile group or a cyano group such as benzonitrile or cyanobenzene, heteroaromatic rings, carbonyl skeletons such as benzophenone, phosphine oxide skeletons, sulfone skeletons, etc., can be used. In this way, π-electron-deficient skeletons and π-electron-excess skeletons can be used instead of at least one of π-electron-deficient heteroaromatic rings and π-electron-excess heteroaromatic rings.

[0169]

[0170] Furthermore, a TADF material in which the singlet excited state and the triplet excited state are in thermal equilibrium may be used as the TADF material. Since such a TADF material has a shorter luminescence lifetime (excitation lifetime), it is possible to suppress the decrease in efficiency in the high-brightness region of the light-emitting device. Specifically, materials with the molecular structure shown below are examples.

[0171]

[0172] TADF materials are materials that have a small energy difference between the S1 and T1 levels and possess the ability to convert energy from triplet excitation energy to singlet excitation energy through reverse intersystem crossing. Therefore, triplet excitation energy can be upconverted to singlet excitation energy with only a small amount of thermal energy (reverse intersystem crossing), and singlet excited states can be efficiently generated. Furthermore, triplet excitation energy can be converted into luminescence.

[0173] Furthermore, an excited complex (also called an exciplex) formed by two types of substances has an extremely small energy difference between the S1 and T1 levels and functions as a TADF material capable of converting triplet excitation energy into singlet excitation energy.

[0174] Furthermore, the phosphorescence spectrum observed at low temperatures (for example, from 77K to 10K) can be used as an indicator of the T1 level. For TADF materials, when a tangent is drawn at the short-wavelength tail of the fluorescence spectrum and the energy at the wavelength of the extrapolation is taken as the S1 level, and when a tangent is drawn at the short-wavelength tail of the phosphorescence spectrum and the energy at the wavelength of the extrapolation is taken as the T1 level, it is preferable that the energy difference between the S1 level and the T1 level is 0.3 eV or less, and more preferably 0.2 eV or less.

[0175] Furthermore, when using TADF material as a light-emitting material, it is preferable that the S1 level of the host material is higher than the S1 level of the TADF material. Also, it is preferable that the T1 level of the host material is higher than the T1 level of the TADF material.

[0176] Various carrier transport materials can be used as the host material for the light-emitting layer, such as materials with electron transport properties and / or hole transport properties, and the TADF material mentioned above.

[0177] Preferred materials with hole transport properties include organic compounds having an amine skeleton or a π-electron-rich heteroaromatic ring skeleton. Preferred π-electron-rich heteroaromatic rings are condensed aromatic rings containing at least one of the following: acridine skeleton, phenoxazine skeleton, phenothiazine skeleton, furan skeleton, thiophene skeleton, and pyrrole skeleton. Specifically, carbazole rings, dibenzothiophene rings, or rings obtained by further condensing an aromatic ring or heteroaromatic ring with these are preferred.

[0178] Organic compounds having such hole-transporting properties more preferably have at least one of the following skeletons: a carbazole skeleton, a dibenzofuran skeleton, a dibenzothiophene skeleton, and an anthracene skeleton. In particular, they may be aromatic amines having substituents including a dibenzofuran ring or a dibenzothiophene ring, aromatic monoamines having a naphthalene ring, or aromatic monoamines in which a 9-fluorenyl group is bonded to the nitrogen of the amine via an arylene group. Furthermore, it is preferable that these hole-transporting organic compounds are substances having an N,N-bis(4-biphenyl)amino group, as this allows for the creation of light-emitting devices with a good lifetime.

[0179] Preferred organic compounds include, for example, the following: 4,4'-bis[N-(1-naphthyl)-N-phenylamino]biphenyl (abbreviated as NPB), N,N'-diphenyl-N,N'-bis(3-methylphenyl)-4,4'-diaminobiphenyl (abbreviated as TPD), N,N'-bis(9,9'-spirobi[9H-fluoren]-2-yl)-N,N'-diphenyl-4,4'-diaminobiphenyl (abbreviated as BSPB), 4-phenyl-4'-(9-phenylfluoren-9-yl)triphenylamine (abbreviated as BPAFLP), 4-phenyl-3'-(9-phenylfluoren-9- 4,4'-(9-phenyl-9H-carbazole-3-yl)triphenylamine (abbreviation: mBPAFLP), 4,4'-diphenyl-4''-(9-phenyl-9H-carbazole-3-yl)triphenylamine (abbreviation: PCBA1BP), 4,4'-diphenyl-4''-(9-phenyl-9H-carbazole-3-yl)triphenylamine (abbreviation: PCBi1BP), 4-(1-naphthyl)-4'-(9-phenyl-9H-carbazole-3-yl)triphenylamine (abbreviation: PCBANB), 4,4'-di(1-naphthyl)-4''-(9-phenyl-9H-carbazole-3-yl ) Compounds having an aromatic amine skeleton such as triphenylamine (abbreviation: PCBNBB), 9,9-dimethyl-N-phenyl-N-[4-(9-phenyl-9H-carbazole-3-yl)phenyl]fluoren-2-amine (abbreviation: PCBAF), N-phenyl-N-[4-(9-phenyl-9H-carbazole-3-yl)phenyl]-9,9'-spirobi[9H-fluoren]-2-amine (abbreviation: PCBASF), 1,3-bis(N-carbazolyl)benzene (abbreviation: mCP), 4,4'-di(N-carbazolyl)biphenyl ( Abbreviation: CBP), 3,6-bis(3,5-diphenylphenyl)-9-phenylcarbazole (abbreviation: CzTP), 3,3'-bis(9-phenyl-9H-carbazole) (abbreviation: PCCP), 3,9-bis(9-phenyl-9H-carbazole-3-yl)-9H-carbazole (abbreviation: PCCzPC), 9-(biphenyl-4-yl)-9'-phenyl-3,3'-bi-9H-carbazole (abbreviation: PCCzBP), 9,9'-bis(biphenyl-4-yl)-3,3'-bi-9H-carbazole (abbreviation: BisBPCz), 9,9'-Bis(biphenyl-3-yl)-3,3'-bi-9H-carbazole (abbreviation: BismBPCz), 9-(biphenyl-3-yl)-9'-(biphenyl-4-yl)-9H,9'H-3,3'-bicarbazole (abbreviation: mBPCCBP), 9-(2-naphthyl)-9'-phenyl-3,3'-bi-9H-carbazole (abbreviation: βNCCP), 9-(3-biphenyl)-9'-(2-naphthyl)-3,3'-bi-9H-carbazole (abbreviation: βNCCmBP), 9-(4-biphenyl)-9'-(2-naphthyl)-3, 3'-bi-9H-carbazole (abbreviation: βNCCBP), 9,9'-di-2-naphthyl-3,3'-9H,9'H-bicarbazole (abbreviation: BisβNCz), 9-(2-naphthyl)-9'-[1,1':4',1"-terphenyl]-3-yl-3,3'-9H,9'H-bicarbazole, 9-(2-naphthyl)-9'-[1,1':3',1"-terphenyl]-3-yl-3,3'-9H,9'H-bicarbazole, 9-(2-naphthyl)-9'-[1,1':3',1"-terphenyl]-5'-yl-3,3'-9H ,9'H-bicarbazole, 9-(2-naphthyl)-9'-[1,1':4',1"-terphenyl]-4-yl-3,3'-9H,9'H-bicarbazole, 9-(2-naphthyl)-9'-[1,1':3',1"-terphenyl]-4-yl-3,3'-9H,9'H-bicarbazole, 9-(2-naphthyl)-9'-(triphenylene-2-yl)-3,3'-9H,9'H-bicarbazole, 9-phenyl-9'-(triphenylene-2-yl)-3,3'-9H,9'H-bicarbazole (abbreviation: PCCzTp), 9,9'-bis(triphenylene-2-yl)-3,3'-9H,9'H-bicarbazole, 9-(4-biphenyl)-9'-(triphenylene-2-yl)-3,3'-9H,9'H-bicarbazole, 9-(triphenylene-2-yl)-9'-[1,1':3',1''-terphenyl]-4-yl-3,3'-9H,9'H-bicarbazole, N,N-bis(9,9-dimethyl-9H-fluoren-2-yl)-9,9'-spirobi-9H-fluoren-1-amine, 9-[3-(triphenylsilyl)phenyl]-3,Compounds having a carbazole skeleton such as 9'-bi-9H-carbazole (abbreviation: PSiCzCz), 9'-[3-(triphenylsilyl)phenyl]-9'H-9,3':6',9''-telcarbazole (abbreviation: PSiCzGI), 4,4',4''-(benzene-1,3,5-triyl)tri(dibenzothiophene) (abbreviation: DBT3P-II), 2,8-diphenyl-4-[4-(9-phenyl-9H-fluoren-9-yl)phenyl]dibenzothiophene (abbreviation: DBTFLP-I) Examples include compounds having a thiophene skeleton such as 4-[4-(9-phenyl-9H-fluoren-9-yl)phenyl]-6-phenyldibenzothiophene (abbreviated as DBTFLP-IV), and compounds having a furan skeleton such as 4,4',4''-(benzene-1,3,5-triyl)tri(dibenzofuran) (abbreviated as DBF3P-II) and 4-{3-[3-(9-phenyl-9H-fluoren-9-yl)phenyl]phenyl}dibenzofuran (abbreviated as mmDBFFLBi-II). Among the above, compounds having an aromatic amine skeleton or a carbazole skeleton are preferred because they have good reliability, high hole transportability, and contribute to reducing the driving voltage. In addition, organic compounds listed as examples of hole transportable materials in the hole transport layer can also be used. Furthermore, it is more preferable to use organic compounds having an amine skeleton or a fluorene skeleton. Furthermore, organic compounds having amine and fluorene skeletons are preferred because they are highly reliable and have high hole transport properties, thereby reducing the power consumption of light-emitting devices.

[0180] For materials exhibiting electron transport properties, the electron mobility at which the square root of the electric field strength [V / cm] is 600 is 1 × 10⁻⁶. −７ cm ２ / Vs or more, preferably 1 x 10 −６ cm ２ A material having an electron mobility of / Vs or higher is preferred. However, any material with higher electron transport capabilities than holes can be used.

[0181] Examples of electron-transporting materials include bis(10-hydroxybenzo[h]quinolinato)beryllium(II) (abbreviated as BeBq). ２Preferably, metal complexes such as bis(2-methyl-8-quinolinolato)(4-phenylphenololato)aluminum(III) (abbreviated as BAlq), bis(8-quinolinolato)zinc(II) (abbreviated as Znq), bis[2-(2-benzoxazollyl)phenololato]zinc(II) (abbreviated as ZnPBO), and bis[2-(2-benzothiazolyl)phenololato]zinc(II) (abbreviated as ZnBTZ), and organic compounds having a π-electron-deficient heteroaromatic ring are preferred. Examples of organic compounds having a π-electron-deficient heteroaromatic ring skeleton include organic compounds containing a heteroaromatic ring having an azole skeleton, organic compounds containing a heteroaromatic ring having a pyridine skeleton, organic compounds containing a heteroaromatic ring having a diazine skeleton, and organic compounds containing a heteroaromatic ring having a triazine skeleton.

[0182] Among these, organic compounds containing heteroaromatic rings having a diazine skeleton (pyrimidine skeleton, pyrazine skeleton, pyridazine skeleton), organic compounds containing heteroaromatic rings having a pyridine skeleton, and organic compounds containing heteroaromatic rings having a triazine skeleton are preferred due to their good reliability. In particular, organic compounds containing heteroaromatic rings having a diazine (pyrimidine or pyrazine) skeleton and organic compounds containing heteroaromatic rings having a triazine skeleton have high electron transport properties and contribute to reducing the driving voltage. Furthermore, benzoflopyrimidine skeletons, benzothienopyrimidine skeletons, benzoflopyrazine skeletons, and benzothienopyrazine skeletons are preferred because they have high acceptor properties and good reliability.

[0183] As organic compounds having a π-electron-deficient heteroaromatic ring skeleton, the following organic compounds are preferred, for example: 2-(4-biphenylyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole (abbreviated as PBD), 3-(4-biphenylyl)-4-phenyl-5-(4-tert-butylphenyl)-1,2,4-triazole (abbreviated as TAZ), 1,3-bis[5-(p-tert-butylphenyl)-1,3,4-oxadiazole-2-yl]benzene (abbreviated as OXD-7), 9-[4-(5-phenyl-1,3,4-oxadiazole-2-yl)phenyl]-9H-carbazole (abbreviated as Organic compounds having an azole skeleton such as CO11), 2,2',2''-(1,3,5-benzenetriyl)tris(1-phenyl-1H-benzimidazole) (abbreviation: TPBI), 2-[3-(dibenzothiophen-4-yl)phenyl]-1-phenyl-1H-benzimidazole (abbreviation: mDBTBIm-II), 4,4'-bis(5-methylbenzoxazole-2-yl)stilbene (abbreviation: BzOs), 3,5-bis[3-(9H-carbazole-9-yl)phenyl]pyridine (abbreviation: 35DCzPPy), 1,3,5-tri[3-(3-pyridyl)phenyl]benzene (abbreviation: TmPyPB), vasophenanthroline (abbreviation: Bphen), vasocuproin (abbreviation: BCP), 2,9-di(naphthalene-2-yl)-4,7-diphenyl-1,10-phenanthroline (abbreviation: NBphen), 2,2'-(1,3-phenylene)bis(9-phenyl-1,10-phenanthroline) (abbreviation: mPPhen2P), 2-[3-(2-triphenylenyl)phenyl]-1,10-phenan Organic compounds containing heteroaromatic rings with a pyridine skeleton, such as throline (abbreviation: mTpPPhen), 2-phenyl-9-(2-triphenylenyl)-1,10-phenanthroline (abbreviation: Ph-TpPhen), 2-[4-(9-phenanthryl)-1-naphthyl]-1,10-phenanthroline (abbreviation: PnNPhen), and 2-[4-(2-triphenylenyl)phenyl]-1,10-phenanthroline (abbreviation: pTpPPhen), 2-[3-(dibenzothiophen-4-yl)phenyl]dibenzo[f,[h]Quinoxaline (abbreviation: 2mDBTPDBq-II), 2-[3'-(dibenzothiophen-4-yl)biphenyl-3-yl]dibenzo[f,h]Quinoxaline (abbreviation: 2mDBTPDBq-II), 2-[3'-(9H-carbazole-9-yl)biphenyl-3-yl]dibenzo[f,h]Quinoxaline (abbreviation: 2mCzBPDBq), 2-[4'-(9-phenyl-9H-carbazole-3-yl)-3,1'-biphenyl-1-yl]dibenzo[f,h]Quinoxaline (abbreviation: 2mpPCBPDBq), 2-[4-(3,6-diphenyl [Lu-9H-carbazole-9-yl)phenyl]dibenzo[f,h]quinoxaline (abbreviation: 2CzPDBq-III), 7-[3-(dibenzothiophen-4-yl)phenyl]dibenzo[f,h]quinoxaline (abbreviation: 7mDBTPDBq-II), and 6-[3-(dibenzothiophen-4-yl)phenyl]dibenzo[f,h]quinoxaline (abbreviation: 6mDBTPDBq-II), 9-[3'-(dibenzothiophen-4-yl)biphenyl-3-yl]naphtho[1',2':4,5]flo[2,3-b]pyrazine (abbreviation: 9mDBtBPNF pr), 9-[3'-(dibenzothiophen-4-yl)biphenyl-4-yl]naphtho[1',2':4,5]flo[2,3-b]pyrazine (abbreviation: 9pmDBtBPNfpr), 4,6-bis[3-(phenanthren-9-yl)phenyl]pyrimidine (abbreviation: 4,6mPnP2Pm), 4,6-bis[3-(dibenzothiophen-4-yl)phenyl]pyrimidine (abbreviation: 4,6mDBTP2Pm-II), 4,6-bis[3-(9H-carbazole-9-yl)phenyl]pyrimidine (abbreviation: 4,6mCzP2Pm), 9,9'-[pyrimidine n-4,6-diylbis(biphenyl-3,3'-diyl)]bis(9H-carbazole) (abbreviation: 4,6mCzBP2Pm), 8-(biphenyl-4-yl)-4-[3-(dibenzothiophen-4-yl)phenyl]-[1]benzoflo[3,2-d]pyrimidine (abbreviation: 8BP-4mDBtPBfpm), 3,8-bis[3-(dibenzothiophen-4-yl)phenyl]benzoflo[2,3-b]pyrazine (abbreviation: 3,8mDBtP2Bfpr), 4,8-bis[3-(dibenzothiophen-4-yl)phenyl]-[1]benzoflo[3,2-d]pyrimidine (abbreviation: 4,8mDBtP2Bfpm), 8-[3'-(dibenzothiophen-4-yl)biphenyl-3-yl]naphtho[1',2':4,5]flo[3,2-d]pyrimidine (abbreviation: 8mDBtBPNfpm), 8-([2,2'-binaphthalene]-6-yl)-4-[3-(dibenzothiophen-4-yl)phenyl]-[1]benzoflo[3,2-d]pyrimidine (abbreviation: 8(βN2)-4mDBtPBfpm), 2,2'-(pyridine-2,6-diyl)bis(4-phenylbenzo[h]quinazoline) (abbreviation: 2,6( P-Bqn)2Py), 2,2'-(pyridine-2,6-diyl)bis{4-[4-(2-naphthyl)phenyl]-6-phenylpyrimidine} (abbreviation: 2,6(NP-PPm)2Py), 6-(biphenyl-3-yl)-4-[3,5-bis(9H-carbazole-9-yl)phenyl]-2-phenylpyrimidine (abbreviation: 6mBP-4Cz2PPm), 2,6-bis(4-naphthalene-1-ylphenyl)-4-[4-(3-pyridyl)phenyl]pyrimidine (abbreviation: 2,4NP-6PyPPm), 4-[3,5-bis(9H-carbazole-9- [Iyl)phenyl]-2-phenyl-6-(biphenyl-4-yl)pyrimidine (abbreviation: 6BP-4Cz2PPm), 7-[4-(9-phenyl-9H-carbazole-2-yl)quinazoline-2-yl]-7H-dibenzo[c,g]carbazole (abbreviation: PC-cgDBCzQz), 8-(p-terphenyl-3-yl)-4-[3-(dibenzothiophen-4-yl)phenyl]-[1]benzofl[3,2-d]pyrimidine (abbreviation: 8mpTP-4mDBtPBfpm), 11-[3'-(dibenzothiophen-4-yl)biphenyl-3-yl Organic compounds having a diazine skeleton such as phenanthr[9',10':4,5]fl[2,3-b]pyrazine (abbreviation: 11mDBtBPPnfpr), 2-(biphenyl-4-yl)-4-phenyl-6-(9,9'-spirobi[9H-fluoren]-2-yl)-1,3,5-triazine (abbreviation: BP-SFTZn), 2-{3-[3-(benzo[b]naphtho[1,2-d]furan-8-yl)phenyl]phenyl}-4,6-diphenyl-1,3,5-triazine (abbreviation: mBnfBPTZn), 2-{3-[3-(benzo[b]naphtho[1,2-d]furan-6-yl)phenyl]phenyl}-4,6-diphenyl-1,3,5-triazine (abbreviation: mBnfBPTZn-02), 2-{4-[3-(N-phenyl-9H-carbazole-3-yl)-9H-carbazole-9-yl]phenyl}-4,6-diphenyl-1,3,5-triazine (abbreviation: PCCzPTZn), 9-[3-(4,6-diphenyl-1,3,5-triazine-2-yl)phenyl]-9'-phenyl-2,3'-bi-9H-carbazole (abbreviation: mPCCzPTZn-02), 2-[3'-(9,9-dimethyl- 9H-Fluoren-2-yl)biphenyl-3-yl]-4,6-diphenyl-1,3,5-triazine (abbreviation: mFBPTZn), 5-[3-(4,6-diphenyl-1,3,5-triazine-2-yl)phenyl]-7,7-dimethyl-5H,7H-indeno[2,1-b]carbazole (abbreviation: mINc(II)PTZn), 2-{3-[3-(dibenzothiophen-4-yl)phenyl]phenyl}-4,6-diphenyl-1,3,5-triazine (abbreviation: mDBtBPTZn), 2,4,6-tris[3'-(pyridine-3-yl)biphenyl [3-yl]-1,3,5-triazine (abbreviation: TmPPPyTz), 2-[3-(2,6-dimethyl-3-pyridinyl)-5-(9-phenanthryl)phenyl]-4,6-diphenyl-1,3,5-triazine (abbreviation: mPn-mDMePyPTzn), 11-[4-(biphenyl-4-yl)-6-phenyl-1,3,5-triazine-2-yl]-11,12-dihydro-12-phenylindoro[2,3-a]carbazole (abbreviation: BP-Icz(II)Tzn), 2-[3'-(triphenylene-2-yl)biphenyl-3-yl]-4 ,6-diphenyl-1,3,5-triazine (abbreviation: mTpBPTZn),3-[9-(4,6-diphenyl-1,3,5-triazine-2-yl)-2-dibenzofuranyl]-9-phenyl-9H-carbazole (abbreviation: PCDBfTZn),2-(biphenyl-3-yl)-4-phenyl-6-[8-([1,1':4',1''-terphenyl]-4-yl)-1-dibenzofuranyl]-1,3,5-triazine (abbreviation: mBP-TPDBfTZn),2-[4-(2-naphthyl)phenyl]-4-phenyl-6-spiro[9H-fluorene-9,9'-[9H]xanthene]-4-yl-1,3,5-triazine (abbreviation: βNP-SFx(4)TZn), 9,9'-{6-[3-(triphenylsilyl)phenyl]-1,3,5-triazine-2,4-diyl}bis(9H-carbazole) (abbreviation: SiTrzCz2), 2-phenyl-4,6-bis[3-(triphenylsilyl)phenyl]-1,3,5-triazine (abbreviation: mSiTrz), 2,4,6-tris(2-pyridyl)-1,3,5-triazine (abbreviation: 2Py3TZn), 11-[ 4-(biphenyl-4-yl)-6-phenyl-1,3,5-triazine-2-yl]-11,12-dihydro-12-(biphenyl-3-yl)indoro[2,3-a]carbazole (abbreviation: BP-mBPIcz(II)TZn), 3-{3-[9-(4,6-diphenyl-1,3,5-triazine-2-yl)-2-dibenzofuranyl]phenyl}-9-phenyl-9H-carbazole (abbreviation: mPCPDBfTZn), 9,9'-[6-(biphenyl-4-yl)-2-phenyl-1,3,5-to [Liazin-4,3''-diyl]bis(9H-carbazole) (abbreviation: Cz-pmCzBPTZn), 3-phenyl-9-[4-phenyl-6-(9-phenyl-3-dibenzofuranyl)-1,3,5-triazin-2-yl]-9H-carbazole (abbreviation: PDBf-PCzTZn), 9-[4-(4,6-diphenyl-1,3,5-triazin-2-yl)-2-dibenzothienyl]-2-phenyl-9H-carbazole (abbreviation: PCzDBtTZn), 2,4-diphenyl-6-[3'-(spiro [7H-benzo[c]fluorene-7,9'-[9H]xanthene]-2'-yl)biphenyl-3-yl]-1,3,5-triazine (abbreviation: mSbfxBPTZn), 3'-[4-phenyl-6-(spiro[9H-fluorene-9,9'-[9H]xanthene]-2'-yl)-1,3,5-triazine-2-yl]biphenyl-4-carbonitrile (abbreviation: mpCNBP-SFxTZn), 2,2'-[1,2-naphthalenediyldi(4,1-phenylene)]bis(4,6-diphenyl-1,3,Examples include organic compounds containing a heteroaromatic ring having a triazine skeleton, such as 5-triazine (abbreviated as TznP2N). Furthermore, organic compounds containing a heteroaromatic ring having a diazine skeleton, or a heteroaromatic ring having a pyridine skeleton, or a heteroaromatic ring having a triazine skeleton are preferred due to their good reliability. In particular, organic compounds containing a heteroaromatic ring having a diazine (pyrimidine or pyrazine) skeleton, or a heteroaromatic ring having a triazine skeleton, exhibit high electron transport properties and contribute to reducing the driving voltage.

[0184] The TADF materials listed above can be used as host materials. When a TADF material is used as a host material, the triplet excitation energy generated by the TADF material is converted into singlet excitation energy through reverse intersystem crossing, and this energy is then transferred to the light-emitting material, thereby increasing the luminescence efficiency of the light-emitting device. In this case, the TADF material functions as an energy donor, and the light-emitting material functions as an energy acceptor.

[0185] This is very effective when the above-mentioned luminescent material is a fluorescent luminescent material. Also, in order to obtain high luminescence efficiency in this case, the S of the TADF material １ The energy level is S of the fluorescent material. １ It is preferable that the level be higher than the level. Also, the T of the TADF material １ The energy level is S of the fluorescent material. １ It is preferable that the level be higher than the level of the TADF material. １ The energy level is the T of the fluorescent material. １ A level higher than the current level is preferable.

[0186] Furthermore, it is preferable to use a TADF material that exhibits emission that overlaps with the wavelength of the lowest-energy absorption band of the fluorescent material. This is preferable because it allows for a smooth transfer of excitation energy from the TADF material to the fluorescent material, resulting in efficient emission.

[0187] Furthermore, for singlet excitation energy to be efficiently generated from triplet excitation energy by reverse intersystem crossing, it is preferable that carrier recombination occurs in the TADF material. It is also preferable that the triplet excitation energy generated in the TADF material does not transfer to the triplet excitation energy of the fluorescent material. To achieve this, it is preferable that the fluorescent material has protecting groups around the luminescent phosphoform (the skeleton that causes luminescence). Preferred protecting groups are substituents without π bonds, saturated hydrocarbons, specifically alkyl groups having 3 to 10 carbon atoms, substituted or unsubstituted cycloalkyl groups having 3 to 10 carbon atoms, and trialkylsilyl groups having 3 to 10 carbon atoms. It is even preferable to have multiple protecting groups. Substituents without π bonds have poor carrier transport function, and therefore can increase the distance between the TADF material and the luminescent phosphoform of the fluorescent material with little effect on carrier transport or carrier recombination. Here, the luminescent phosphoform refers to the atomic group (skeleton) that causes luminescence in the fluorescent material. The luminescent phosphophore preferably has a skeleton containing π bonds, preferably contains an aromatic ring, and preferably has a condensed aromatic ring or a condensed heteroaromatic ring. Examples of such luminescent phosphophores include phenanthrene skeletons, stilbene skeletons, acridone skeletons, phenoxazine skeletons, phenothiazine skeletons, naphthalene skeletons, anthracene skeletons, fluorene skeletons, chrysene skeletons, triphenylene skeletons, tetracene skeletons, pyrene skeletons, perylene skeletons, coumarin skeletons, quinacridone skeletons, and naphthobisbenzofuran skeletons. Fluorescent materials having naphthalene, anthracene, fluorene, chrysene, triphenylene, tetracene, pyrene, perylene, coumarin, quinacridone, and naphthobisbenzofuran skeletons are particularly preferred due to their high fluorescence quantum yield.

[0188] When using a fluorescent material as a light-emitting material, a material having an acene skeleton, particularly an anthracene skeleton, is preferred as the host material. Using a material having an anthracene skeleton as the host material for a fluorescent material makes it possible to realize a light-emitting layer with good luminescence efficiency and durability. Among the materials having an anthracene skeleton to be used as the host material, a material having a diphenylanthracene skeleton, particularly a 9,10-diphenylanthracene skeleton, is preferred because it is chemically stable. Furthermore, while a carbazole skeleton is preferred as the host material because it improves hole injection and transport, a benzocarbazole skeleton, in which a benzene ring is further condensed into the carbazole, is even more preferred because the HOMO level is about 0.1 eV higher than when only a carbazole skeleton is present, making it easier for holes to enter. In particular, a dibenzocarbazole skeleton is preferred as the host material is about 0.1 eV higher than when only a carbazole skeleton is present, making it easier for holes to enter, as well as providing excellent hole transport and high heat resistance. Therefore, a more preferred host material is a substance having a 9,10-diphenylanthracene skeleton and a carbazole skeleton (or a benzocarbazole skeleton or dibenzocarbazole skeleton). Furthermore, from the viewpoint of hole injection and transport, a benzofluorene skeleton or a dibenzofluorene skeleton may be used instead of the carbazole skeleton. Also, it is preferable to include a dibenzofuran skeleton because reliability can be ensured without lowering the T1 level.

[0189] Examples of such substances include 9-phenyl-3-[4-(10-phenyl-9-antryl)phenyl]-9H-carbazole (abbreviated as PCzPA), 3-[4-(1-naphthyl)phenyl]-9-phenyl-9H-carbazole (abbreviated as PCPN), 9-[4-(10-phenyl-9-antryl)phenyl]-9H-carbazole (abbreviated as CzPA), 7-[4-(10-phenyl-9-antryl)phenyl]-7H-dibenzo[c,g]carbazole (abbreviated as cgDBCzPA), 6-[3-(9,10-diphenyl-2-antryl)phenyl]benzo[b]naphtho[1,2-d]furan (abbreviated as 2mBnfPPA), and 9-phenyl-10-[4-(9-phenyl-9H-fluoren-9-yl)biphenyl-4' -yl]anthracene (abbreviation: FLPPA), 9-(1-naphthyl)-10-[4-(2-naphthyl)phenyl]anthracene (abbreviation: αN-βNPAnth), 9-(1-naphthyl)-10-(2-naphthyl)anthracene (abbreviation: α,βADN), 2-(10-phenylanthracene-9-yl)dibenzofuran, 2-(10-phenyl-9-antryl)ben Examples include zo[b]naphtho[2,3-d]furan (abbreviated as Bnf(II)PhA), 9-(2-naphthyl)-10-[3-(2-naphthyl)phenyl]anthracene (abbreviated as βN-mβNPAnth), and 1-{4-[10-(biphenyl-4-yl)-9-anthryl]phenyl}-2-ethyl-1H-benzimidazole (abbreviated as EtBImPBPhA). In particular, CzPA, cgDBCzPA, 2mBnfPPA, and PCzPA are preferred choices because they exhibit very good properties.

[0190] The host material may be a mixture of multiple substances, and when using a mixed host material, it is preferable to mix an electron-transporting material with a hole-transporting material. By mixing an electron-transporting material with a hole-transporting material, the transport properties of the light-emitting layer can be easily adjusted, and the recombination region can also be easily controlled. The weight ratio of the hole-transporting material to the electron-transporting material should be 1:19 to 19:1.

[0191] Furthermore, phosphorescent materials can be used as part of the above-mentioned mixed materials. When a fluorescent material is used as the light-emitting material, the phosphorescent material can be used as an energy donor to supply excitation energy to the fluorescent material.

[0192] Furthermore, these mixed materials may form an excited complex. It is preferable to select a combination that forms an excited complex that exhibits emission overlapping with the wavelength of the lowest-energy absorption band of the luminescent material, as this facilitates smooth energy transfer and efficiently obtains light emission. This configuration is also preferable because it reduces the driving voltage.

[0193] Furthermore, at least one of the materials forming the excitation complex may be a phosphorescent material. This allows for the efficient conversion of the triplet excitation energy to the singlet excitation energy through reverse intersystem crossing.

[0194] For efficient excitation complex formation, it is preferable that the HOMO level of the hole-transporting material is above the HOMO level of the electron-transporting material. Furthermore, it is preferable that the LUMO level of the hole-transporting material is above the LUMO level of the electron-transporting material. The LUMO and HOMO levels of the materials can be derived from the electrochemical properties (reduction potential and oxidation potential) of the materials measured by cyclic voltammetry (CV).

[0195] The formation of excited complexes can be confirmed, for example, by comparing the emission spectra of a hole-transporting material, an electron-transporting material, and a mixed film made by mixing these materials, and observing that the emission spectrum of the mixed film shifts to a longer wavelength than the emission spectra of each individual material (or has a new peak on the longer wavelength side). Alternatively, it can be confirmed by comparing the transient photoluminescence (PL) of a hole-transporting material, the transient PL of an electron-transporting material, and the transient PL of a mixed film made by mixing these materials, and observing differences in the transient response, such as the transient PL lifetime of the mixed film having a longer lifetime component or a larger proportion of the delayed component than the transient PL lifetime of each individual material. Furthermore, the transient PL mentioned above may be read as transient electroluminescence (EL). That is, the formation of excited complexes can also be confirmed by comparing the transient EL of a hole-transporting material, the transient EL of an electron-transporting material, and the transient EL of a mixed film made by mixing these materials, and observing the differences in the transient response.

[0196] [Manufacturing Method Example 1] Below, an example of a manufacturing method for a display device according to one embodiment of the present invention will be described with reference to the drawings. Here, the display device 100 shown in the above configuration example will be used as an example. Figures 7A to 20B are schematic cross-sectional views of each step in the manufacturing method of the display device illustrated below.

[0197] Furthermore, thin films (insulating films, semiconductor films, conductive films, etc.) that constitute the display device can be formed using methods such as sputtering, chemical vapor deposition (CVD), vacuum deposition, pulsed laser deposition (PLD), and atomic layer deposition (ALD).

[0198] Furthermore, thin films (insulating films, semiconductor films, conductive films, etc.) that constitute the display device can be formed by methods such as spin coating, dip coating, spray coating, inkjet printing, dispensing, screen printing, offset printing, doctor knife coating, slit coating, roll coating, curtain coating, and knife coating.

[0199] Sputtering methods include RF sputtering, which uses a high-frequency power supply for sputtering; DC sputtering, which uses a DC power supply; and pulsed DC sputtering, which changes the voltage applied to the electrodes in pulses. For film deposition using insulating targets, RF sputtering is preferable. DC sputtering is mainly used when depositing films using conductive targets. In addition to forming conductive films, DC sputtering can also be used to form insulating films by reactive sputtering using pulsed DC sputtering. Specifically, pulsed DC sputtering can be used when depositing compounds such as oxides, nitrides, and carbides using reactive sputtering.

[0200] CVD methods can be classified into plasma-enhanced CVD (PECVD), which utilizes plasma; thermal CVD (TCD), which utilizes heat; and photo-CVD (Photo-CVD), which utilizes light. Furthermore, depending on the source gas used, they can be divided into metal CVD (MCCVD) and metal-organic CVD (MOCVD) methods.

[0201] Plasma CVD allows for the production of high-quality films at relatively low temperatures. Thermal CVD, on the other hand, does not use plasma, thus minimizing plasma damage to the workpiece. Furthermore, thermal CVD avoids plasma damage during film formation, resulting in films with fewer defects.

[0202] As ALD methods, thermal ALD, which carries out the reaction of the precursor and reactant using only thermal energy, and PEALD, which uses plasma-excited reactants, can be used.

[0203] Unlike sputtering, CVD and ALD are film deposition methods that are less affected by the shape of the workpiece and provide good step-level coverage. In particular, the ALD method is suitable for coating the surface of openings with high aspect ratios due to its excellent step-level coverage and excellent thickness uniformity. However, since the ALD method has a relatively slow deposition rate, it is sometimes preferable to use it in combination with other film deposition methods that have a faster deposition rate, such as the CVD method.

[0204] In CVD (Chemical Vapor Deposition), films of any composition can be deposited by changing the flow rate ratio of the raw material gases. For example, in CVD, by changing the flow rate ratio of the raw material gases while the film is being deposited, films with continuously changing compositions can be deposited. When depositing films while changing the flow rate ratio of the raw material gases, the time required for film deposition can be shortened compared to depositing films using multiple deposition chambers, because time spent on transport or pressure adjustment is eliminated. Therefore, it may be possible to increase the productivity of semiconductor devices.

[0205] In the ALD method, films of any composition can be deposited by using multiple different types of precursors. Alternatively, when multiple different types of precursors are introduced, films of any composition can be deposited by controlling the number of cycles for each precursor. Furthermore, similar to the CVD method, films with continuously changing compositions can be deposited.

[0206] Furthermore, the thin films constituting the display device can be processed using photolithography or other methods. Alternatively, the thin films may be processed by nanoimprint lithography, sandblasting, lift-off methods, etc. Island-like thin films may also be directly formed using a film deposition method with a shielding mask such as a metal mask. Induced self-assembly (DSA) methods may also be used.

[0207] There are two main methods of photolithography. One method involves forming a resist mask on the thin film to be processed, then processing the thin film by etching or other means, and removing the resist mask. The other method involves forming a photosensitive thin film, then exposing and developing it to process the thin film into the desired shape.

[0208] In photolithography, the light used for exposure can be, for example, i-line (wavelength 365 nm), g-line (wavelength 436 nm), h-line (wavelength 405 nm), or a mixture thereof. Other light sources such as ultraviolet light, KrF laser light, or ArF laser light can also be used. Exposure may also be performed using immersion lithography. Furthermore, extreme ultraviolet (EUV) light or X-rays may be used as the light source for exposure. An electron beam can also be used instead of the light source for exposure. Using extreme ultraviolet light, X-rays, or an electron beam is preferable because it enables extremely fine processing. Note that a photomask is not required when exposure is performed by scanning a beam such as the above-mentioned light or an electron beam.

[0209] Thin films can be etched using methods such as dry etching, wet etching, and sandblasting. Dry etching allows for isotropic or anisotropic etching by controlling the conditions. Wet etching allows for isotropic etching.

[0210] First, a substrate 101 is prepared, and a transistor 150, an insulating layer 131, an insulating layer 132, etc. are formed on it. Next, a conductive film is deposited on the insulating layer 132, and unnecessary parts are removed by etching to form the pixel electrode 111R, pixel electrode 111G, and pixel electrode 111B. This makes it possible to provide the pixel electrode 111R, pixel electrode 111G, and pixel electrode 111B on the substrate at a distance from each other.

[0211] When using a conductive film that is reflective to visible light as each pixel electrode 111, it is preferable to use a material (for example, silver or aluminum) that has the highest possible reflectivity across the entire wavelength range of visible light. This not only improves the light extraction efficiency of the light-emitting element but also enhances color reproduction.

[0212] Next, an insulating layer 133 is formed by covering the ends of each pixel electrode 111. An organic insulating film or an inorganic insulating film can be used as the insulating layer 133. It is preferable that the ends of the insulating layer 133 be tapered in order to improve the step coverage of the subsequent EL film. In particular, when using an organic insulating film, it is preferable to use a photosensitive material because it is easier to control the shape of the ends depending on the exposure and development conditions.

[0213] Next, a conductive film 120f, which will later become the partition wall 120, is formed. It is preferable to use a material for the conductive film 120f that allows for a large selectivity ratio between the etching rate and each pixel electrode 111. It is preferable to use different conductive materials for the conductive film 120f and the layer located at the top of the pixel electrode 111. Alternatively, a film that functions as an etching stopper may be formed before the conductive film 120f, and this film located on the pixel electrode 111 may be removed after etching of the conductive film 120f. In that case, the same conductive material can be used for the pixel electrode 111 and the conductive film 120f.

[0214] Next, a resist mask 141 is formed on the conductive film 120f (Figure 7A). Subsequently, the portion of the conductive film 120f not covered by the resist mask 141 is removed by etching to form a partition wall 120, and then the resist mask 141 is removed (Figure 7B). Note that in Figures 7A, 7B, and the following Figures 7C and 7D, some components such as the substrate 101, transistor 150, and insulating layer 132 are omitted.

[0215] The conductive film 120f can be etched by an isotropic etching method. For example, a wet etching method or an isotropic dry etching method can be used. By processing the conductive film 120f so that etching proceeds faster at the bottom than at the top, a partition wall 120 having an inverse tapered shape can be formed.

[0216] For example, by selecting materials such that the adhesion between the conductive film 120f and the insulating layer 133 is lower than the adhesion between the conductive film 120f and the resist mask 141, the etching rate at the bottom is improved compared to the top, and a reverse tapered partition wall 120 can be formed. For example, if a conductive oxide such as indium tin oxide is used for the conductive film 120f, an organic material with low adhesion to indium tin oxide (e.g., acrylic resin) can be used for the insulating layer 133.

[0217] Next, an EL layer 112 is formed on each pixel electrode 111 and the partition wall 120 (Figure 7C). At this time, the EL layer 112 is stepped by the partition wall 120, and is formed between the partition walls 120 and on top of the partition walls 120, respectively. The EL layer 112 can be formed using, for example, vacuum deposition, sputtering, or both.

[0218] Each light-emitting element 110 can be manufactured through the above process.

[0219] Next, a protective layer 135 is formed to cover the upper electrode 113 (Figure 7E). The protective layer 135 is preferably formed by a film deposition method that provides high step coverage, and is preferably formed by CVD or ALD. The ALD method is particularly preferred because it causes less damage to the layer to be formed.

[0220] For example, an aluminum oxide film can be formed as the protective layer 135 by the ALD method. In this case, it is preferable to use trimethylaluminum, triethylaluminum, triisobutylaluminum, dimethylaluminum hydride, tris(dimethylamino)aluminum, tris(diethylamino)aluminum, or aluminum trichloride as the aluminum precursor. Furthermore, as the oxidizing agent, for example, ozone (O) ３ ), oxygen (O ２ ), water (H ２ O), Nitrogen dioxide (NO) ２ ), nitrous oxide (N ２ O), hydrogen peroxide (H ２ O ２ ) and others can be used, and two or more of these may be used.

[0221] Furthermore, the protective layer 135 may be a laminated structure of a film deposited by the ALD method and a film deposited by a film deposition method other than the ALD method (e.g., CVD method, sputtering method, etc.). While the ALD method has extremely high step coverage, its deposition rate is relatively slow compared to other film deposition methods. Therefore, by first depositing a film with very few defects using the ALD method, and then forming a thick insulating film using the CVD method or the like, the time required for the deposition process of the protective layer 135 can be shortened.

[0222] Next, a wavelength conversion layer 162 and a color filter 161 are sequentially formed on the substrate 164 using the method described below.

[0223] First, prepare circuit board 164.

[0224] Next, color filters 161R and 161G are formed on the substrate 164. Subsequently, layer 137 is formed so as to cover color filters 161R, 161G and the substrate 164.

[0225] Next, a separation layer 163 is formed on layer 137 (Figure 8A). For example, an organic resin can be used as the separation layer 163. Here, as an example, a photosensitive resin is used.

[0226] Next, a wavelength conversion layer 162R is formed on layer 137 (Figure 8B). The wavelength conversion layer 162R can be formed using droplet ejection (e.g., inkjet method), coating method, imprint method, various printing methods (screen printing, offset printing), etc. Alternatively, by using a photosensitive resin material as the organic resin, the layer may be formed by coating the organic resin using a spin coating method, etc., followed by exposure treatment and development treatment, and then processing into an arbitrary shape.

[0227] Here, as an example, the wavelength conversion layer 162R is formed using an inkjet method.

[0228] Next, a wavelength conversion layer 162G is formed on layer 137 (Figure 8C). The wavelength conversion layer 162G can be formed using the same method as the wavelength conversion layer 162R.

[0229] Next, layer 136 is formed on the wavelength conversion layer 162R, wavelength conversion layer 162G, and separation layer 163 (Figure 8D).

[0230] When an inorganic insulating layer is used as layer 136, it can be formed using methods such as sputtering, CVD, or ALD.

[0231] Next, layer 134f is formed on the configuration shown in Figure 7E (Figure 9A). Layer 134f may have, for example, a resin layer. In a later step, layer 134 can be obtained by performing a predetermined treatment on layer 134f. For example, layer 134 can be obtained by curing the resin layer of layer 134f through heat treatment, light irradiation treatment, etc.

[0232] Next, the configuration shown in Figure 9A and the configuration shown in Figure 8D are bonded together (Figure 9B). Specifically, for example, the surface of the substrate 101 on which the transistor 150, light-emitting element 110, layer 134f, etc. are formed is superimposed on the surface of the substrate 164 on which the color filter 161, wavelength conversion layer 162, layer 136, etc. are formed, and then the two are bonded together by curing layer 134f.

[0233] The display device 100 can be manufactured through the above process.

[0234] The method for forming the EL layer 112 will be explained using Figures 10A and 10B. It is preferable to form the EL layer 112 using a highly anisotropic film formation method. That is, as shown in Figure 10A, the film is formed such that the flight direction of the film formation material 121 is approximately perpendicular to the upper surface of the substrate 101. This allows for the creation of a stepped structure by the partition wall 120, as shown in Figure 10B. At this time, it is also preferable that sufficient space is secured between the EL layer 112 and the partition wall 120 for the upper electrode 113 to fit into.

[0235] Next, the upper electrode 113 is formed by covering the EL layer 112, etc. (Figure 11E). At this time, the upper electrode 113 is formed so as to cover the edges of the EL layer 112 and to be in contact with at least a part of the side surface of the partition wall 120. The upper electrode 113 can be formed using one or more of the following methods: vacuum deposition, sputtering, and CVD.

[0236] The method for forming the upper electrode 113 will be explained using Figures 11A to 11E. It is preferable to form the upper electrode 113 using a film formation method with lower anisotropy than that of the EL layer 112. That is, it is preferable to use a film formation method in which the flight direction of the film formation material for the upper electrode 113 has components not only perpendicular to the upper surface of the substrate but also obliquely. For example, a film formation method with lower anisotropy can be achieved by reducing the distance between the deposition source (or sputtering target) and the substrate, using multiple deposition sources (or sputtering targets), or increasing the area of ​​the deposition source (or sputtering target).

[0237] Furthermore, as shown in Figure 11A, a film deposition apparatus can be used that has a mechanism for launching the film deposition material 122 from an oblique direction onto the upper surface of the substrate 101 and rotating the substrate 101 on a rotation axis 125. In Figure 11A, an example is shown in which the rotation axis 125 passes through the center of the substrate 101, but it may pass anywhere on the substrate 101, or the rotation axis 125 may be located off-center from the substrate 101. Also, the rotation axis 125 does not have to be perpendicular to the substrate surface of the substrate 101.

[0238] Alternatively, as shown in Figure 11B, a film deposition apparatus may be used that has a mechanism in which the substrate 101 rotates (oscillates) on a rotation axis 125 parallel to the substrate surface. In this case, the flight direction of the film deposition material 122 can be perpendicular to the rotation axis 125.

[0239] By using a film deposition apparatus having the mechanisms shown in Figures 11A and 11B, as shown in Figure 11C, the film deposition process of the upper electrode 113 can include a period during which the deposition material 122 flies from an oblique direction relative to the substrate surface of the substrate 101, and a period during which it flies from an oblique direction opposite to that, as shown in Figure 11D. Therefore, as shown in Figure 11E, the upper electrode 113 can also be deposited on the side surface of the partition wall 120 which has an inverse tapered shape.

[0240] In addition, the above example shows a case where the substrate 101 moves, but the configuration may also be such that only the deposition source moves, or both the substrate 101 and the deposition source move.

[0241] [Example of a film deposition apparatus] Below, an example of a film deposition apparatus capable of continuously forming the EL layer, upper electrode, and protective layer without exposure to the atmosphere will be described. The film deposition apparatus exemplified below can be used to deposit the EL layer 112, upper electrode 113, and protective layer 135 in each light-emitting element 110.

[0242] A schematic diagram of the film deposition apparatus is shown in Figure 12A. The film deposition apparatus has a transport chamber TF at its center, and includes an input chamber LL, an output chamber UL, a processing chamber HT, film deposition chambers EL1 to EL8, a film deposition chamber ALD, and a film deposition chamber SP. The transport chamber TF has a transport robot RBT, which can transport substrates 101 into and out of each chamber. The chambers are sometimes referred to as chambers.

[0243] Vacuum pumps are connected to the transport chamber TF and each of the rooms, maintaining a reduced pressure state. Gate valves are also installed between the transport chamber TF and each room, allowing for individual control of pressure, temperature, and other atmospheric conditions in each room.

[0244] The loading room LL is a room for loading the circuit board 101, and the unloading room UL is a room for unloading the circuit board 101. Both the loading room LL and the unloading room UL are equipped with gate valves that connect to the outside.

[0245] The substrate 101 can be heated in the processing chamber HT. The processing chamber HT has a baking device. For example, it may be a hot plate type baking device, or a baking device having a resistance heater or an infrared lamp.

[0246] In deposition chambers EL1 to EL8, films constituting the EL layer 112 can be deposited. Deposition chambers EL1 to EL8 are equipped with, for example, a vacuum deposition apparatus or a sputtering apparatus.

[0247] For example, the apparatus includes a deposition chamber EL1 for depositing a hole injection layer, a deposition chamber EL2 for depositing a hole transport layer, a deposition chamber EL3 for depositing an electron blocking layer, a deposition chamber EL4 for depositing an emissive layer, a deposition chamber EL5 for depositing a hole blocking layer, a deposition chamber EL6 for depositing an electron transport layer, a deposition chamber EL7 for depositing an electron injection layer, and a deposition chamber EL8 for depositing a charge generation layer.

[0248] In the deposition chamber SP, the upper electrode 113 can be deposited. For example, the deposition chamber SP has a sputtering apparatus.

[0249] In the ALD deposition chamber, a protective layer 135 can be deposited. The ALD deposition chamber includes, for example, an ALD apparatus.

[0250] Although Figure 12A shows an example with one transport chamber TF, a configuration in which multiple transport chambers TF are connected is also possible. Figure 12B shows an example in which three transport chambers TF are connected. One transport robot RBT is provided for each transport chamber TF. In the example shown in Figure 12B, four to six rooms can be connected to one transport chamber TF, excluding the loading room LL and the unloading room UL. In Figure 12B, up to three more rooms can be added depending on the application.

[0251] Next, an example of a film deposition method using a film deposition apparatus will be described. First, as shown in Figure 7B, the substrate 101, which has been formed up to the partition wall 120, is brought into the film deposition apparatus from the loading chamber LL and subjected to heat treatment in the processing chamber HT. Heat treatment removes moisture and other substances adsorbed on the surface. Next, the hole injection layer, hole transport layer, electron blocking layer, light emitting layer, hole blocking layer, electron transport layer, and electron injection layer are deposited in sequence in film deposition chambers EL1 to EL7. Next, the upper electrode is deposited in film deposition chamber SP. Next, the protective layer 135 is deposited in film deposition chamber ALD, and then the substrate 101 is discharged to the outside from the discharge chamber UL. In this way, the EL layer 112, the upper electrode 113, and the protective layer 135 can be formed continuously without exposing the substrate 101 to the atmosphere.

[0252] Furthermore, using the above-described film deposition apparatus, it is also possible to form a light-emitting element having a so-called tandem structure, which has multiple light-emitting layers separated by a charge generation layer.

[0253] First, as described above, the substrate 101 is subjected to heat treatment in the processing chamber, and then sequentially placed into deposition chambers EL1 to EL7, where the holes are injected and the electrons are injected in order. Next, the charge generation layer is deposited in deposition chamber EL8. After that, the holes are injected and the electrons are injected again sequentially in deposition chambers EL1 to EL7. Subsequently, as described above, the upper electrode 113 is deposited in deposition chamber SP, the protective layer 135 is deposited in deposition chamber ALD, and the substrate 101 is discharged from discharge chamber UL. This makes it possible to fabricate a light-emitting element having a two-stage tandem structure in which two light-emitting layers are stacked with a charge generation layer in between.

[0254] In addition, at least one of the layers constituting the charge generation layer is deposited in the deposition chamber EL8. Furthermore, at least one of the electron injection layer and hole injection layer deposited before or after the deposition process in the deposition chamber EL8 can also serve as a layer constituting the charge generation layer. For example, when the charge generation layer has a laminated structure of an electron injection buffer layer, an electron relay layer, and a P-type layer, the electron injection layer may function as an electron injection buffer layer, and the hole injection layer may function as a P-type layer. In this case, the electron relay layer may also be deposited in the deposition chamber EL8.

[0255] Furthermore, in the case of a light-emitting element having an N-stage (N is a natural number of 2 or more) tandem structure, the film deposition process in deposition chambers EL1 to EL8 is repeated N-1 times, and then the film deposition in deposition chamber EL8 is omitted only for the last N time to form the upper electrode 113 and protective layer 135.

[0256] The above is a description of the film deposition apparatus and the film deposition method using it.

[0257] Figure 13 shows an example of a different film deposition apparatus configuration. The film deposition apparatus shown in Figure 13 has a configuration in which three transport chambers (transport chamber TF1, transport chamber TF2, and transport chamber TF3) are connected.

[0258] Transport chamber TF1 is connected to the loading chamber LL, three deposition chambers (deposition chambers EL11, EL12, and EL13), and processing chamber HT. Transport chamber TF2 is connected to four deposition chambers (deposition chambers EL14, EL15, EL16, and SP). Transport chamber TF3 is connected to the deposition chamber ALD and processing chamber PP, where post-processing such as sealing is performed. In the configuration shown in Figure 14, the loading chamber LL also serves as the unloading chamber, allowing substrates to be loaded and unloaded using the loading chamber LL.

[0259] Deposition chambers EL11 to EL16 are equipped with vacuum deposition apparatus and can deposit organic or inorganic films. Deposition chambers SP, ALD, and HT can be described in the same way as above.

[0260] Here, it is preferable that conveying chambers TF1 and TF2 are under a reduced pressure atmosphere. On the other hand, it is preferable that conveying chamber TF3 is under atmospheric pressure or a pressurized (positive pressure) atmosphere. The interior of conveying chamber TF3 is preferably an atmosphere mainly composed of nitrogen or an inert gas such as a noble gas, and it is preferable that an atmosphere free of water as much as possible is maintained.

[0261] The sealing device in the PP processing chamber and the ALD device in the ALD film deposition chamber may perform processing in a reduced-pressure atmosphere, but they may not require the same high vacuum level as a vacuum deposition apparatus. For example, a vacuum deposition apparatus maintains a reduced-pressure state inside the chamber and performs film deposition processing under a reduced-pressure atmosphere, whereas the ALD device and sealing device may change the pressure significantly during processing. Therefore, it is not necessary to maintain a reduced-pressure atmosphere in the transport chamber TF3. Maintaining positive pressure inside the transport chamber TF3 is preferable because it prevents minute dust from entering from the outside and keeps the interior clean. Furthermore, transport chambers TF1 and TF2 are constructed to withstand high vacuum levels by using metal components for their exteriors. On the other hand, since high airtightness is not required for transport chamber TF3, it can be constructed using lightweight materials such as acrylic resin.

[0262] Furthermore, a mechanism for unloading substrates may be provided in either the processing chamber PP or the transport chamber TF3, or both. This eliminates the need to return the substrates processed in the processing chamber PP or the film deposition chamber ALD back to the transport chamber TF1, transport chamber TF2, etc., which are under reduced pressure, thus shortening the time required for substrate unloading. In this case, it is preferable to use a highly airtight container such as a FOUP (Front-Opening Unified Pod) or FOSB (Front-Opening Shipping Box) for unloading the substrates, as this allows the substrates to be transferred to external equipment without being exposed to the atmosphere.

[0263] In the film deposition apparatus shown in Figure 13, the substrate is brought in from the loading chamber LL, heat-treated in the processing chamber HT, and then the thin films constituting the light-emitting elements are deposited in the respective deposition chambers connected to the transport chambers TF1 and TF2. After that, the substrate is transported to the transport chamber TF3, where a protective film can be formed in the deposition chamber ALD. In this way, the substrate is not exposed to the atmosphere until the protective film is formed, making it possible to manufacture highly reliable light-emitting elements. Furthermore, even after all the light-emitting elements have been manufactured, the substrate can be processed continuously without being exposed to the atmosphere between the protective film formation process in the deposition chamber ALD and the sealing process in the processing chamber PP. This prevents defects such as sealing failures due to dust, and improves the manufacturing yield.

[0264] The above is a description of the film deposition apparatus and the film deposition method using it.

[0265] [Example of Evaporation Apparatus Configuration] Here, a configuration of an evaporation apparatus suitable for a large substrate 101 will be described. The evaporation apparatus illustrated below can be applied to the above-mentioned film formation chambers EL1 to EL8 and film formation chambers EL11 to EL16. The evaporation apparatus illustrated below can be used for both each EL layer 112 and the upper electrode 115.

[0266] When uniformly depositing a film on a large substrate 101, using multiple deposition sources makes it possible to shorten the time required for film deposition and to deposit a film with uniform thickness without unevenness.

[0267] For example, as shown in Figure 14A, a unit 127a can be used in which a plurality of nozzles 128 are arranged at equal intervals in one direction. A deposition source is placed in each nozzle 128, and a film-forming material 123 is injected from the nozzles 128 in a roughly conical shape. The spread of the film-forming material 123 is determined by the shape of the nozzles 128, the distance between the substrate 101 and the nozzles 128, etc. The unit 127a can be moved in a direction intersecting the direction of arrangement of the nozzles 128 (for example, a perpendicular direction). A configuration in which the unit 127a can be moved is preferable because it can reduce the footprint of the film-forming chamber. Alternatively, the unit 127a may be fixed and the substrate 101 may be moved.

[0268] The configuration shown in Figure 14B has multiple units 127b. Each unit 127b is provided with a nozzle 128. Each unit 127b has a long shape in one direction and has a mechanism that allows the nozzle 128 to move in that longitudinal direction. Multiple units 127b are arranged in directions that intersect the longitudinal direction (for example, perpendicular directions). With the positions of the substrate 101 and the units 127b fixed, a film can be formed on the entire surface of the substrate 101 by moving the nozzle 128 of each unit 127b. With this configuration, there is no need to move large units 127b, so the apparatus configuration can be simplified.

[0269] Although a configuration using multiple nozzles was described above, a configuration using only one nozzle is also possible. The configuration shown in Figure 14C has one unit 127c equipped with one nozzle 128. The unit 127c has a mechanism that allows it to move in two orthogonal directions. By fixing the position of the substrate 101 and scanning the unit 127c in a zigzag pattern, a film can be formed on the entire surface of the substrate 101.

[0270] Next, we will explain the relationship between the film deposition method and the incident angle of the deposition material.

[0271] Figure 15A schematically shows a method of film deposition (also called the point source method) in which the positions of both the substrate 101 and the nozzle 128 are fixed. Above the nozzle 128, at a distance D ＴＳA substrate 101 is placed at a distance of DTS, and the film-forming material 123 is injected upward from the nozzle. In this case, in order to uniformly form a film on the substrate 101, it is important to increase the distance DTS and place the substrate 101 within the range in which the film-forming material 123 reaches the same height as the substrate surface. In this case, if the film-forming material 123 diffuses from the nozzle 128 at a solid angle a, the maximum angle of incidence of the film-forming material 123 reaching the substrate 101 will be an angle smaller than the solid angle a (angle b). Thus, the point source method is a method in which the film-forming material 123 has high straightness and is less likely to wrap around. Note that even in the point source method, the distance D ＴＳ It is also possible to bring them closer.

[0272] Figure 15B schematically shows a method of depositing a film while moving the nozzle 128 parallel to the substrate surface (also called the moving cell method). Because the nozzle 128 can be moved, the distance D is greater than that of the point source method. ＴＳ This can reduce the amount of radiation required. The maximum angle of incidence of the deposition material 123 reaching the substrate 101 is equal to the solid angle a. Thus, the moving cell method is a method in which the deposition material 123 has lower straightness of propagation and is more likely to wrap around than the point source method. ＴＳ By widening the nozzle, it is possible to improve the straight-line propagation of the film-forming material 123. The same applies when the substrate 101 is moved instead of the nozzle 128.

[0273] In the above-described example of a method for manufacturing a display device, when forming each EL layer 112, it is preferable to form the film using a film formation method that has high linearity of the film formation material, and when forming the upper electrode 115, it is preferable to form the film using a film formation method that has low linearity of the film formation material.

[0274] Furthermore, when a metal material such as silver is deposited as the upper electrode 115 by vacuum deposition, the temperature of the crucible rises to over 1000°C, and the distance D between the substrate 101 and the nozzle 128 increases. ＴＳIn some cases, it is difficult to bring the materials close together. In such cases, it is preferable to combine a film deposition method with high linearity of the film deposition material and a film deposition method with low linearity (for example, sputtering) to form a layered structure. For example, the upper electrode 115 can be a two-layer structure in which an alloy film containing silver and magnesium is deposited by vacuum deposition, and then an oxide conductive film containing indium is deposited by sputtering.

[0275] The above is a description of an example configuration of a vapor deposition apparatus.

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

[0277] (Embodiment 2) This embodiment describes an indium oxide film that can be used in the semiconductor layer of a transistor in a display device according to one aspect of the present invention.

[0278] In this specification, indium oxide having at least a crystalline portion or crystalline region in the film is referred to as crystalline indium oxide (crystal IO) or crystalline indium oxide (crystalline IO). Examples of crystal IO or crystalline IO include single-crystal indium oxide, polycrystalline indium oxide, and microcrystalline indium oxide.

[0279] Indium oxide is a semiconductor material with completely different physical properties from oxide semiconductors such as In-Ga-Zn oxide (hereinafter also referred to as IGZO) and zinc oxide.

[0280] This paper describes the carrier concentration dependence of the hole mobility of indium oxide, silicon, and IGZO.

[0281] IGZO tends to exhibit higher hole mobility as the carrier concentration increases. On the other hand, single-crystal indium oxide tends to exhibit higher hole mobility as the carrier concentration decreases. This tendency is similar to that of silicon, and the lower the concentration of dopants (impurities) in the material, the more impurity scattering is reduced and the higher the hole mobility becomes. That is, the higher the purity and the more intrinsic the single-crystal indium oxide is, the higher the hole mobility becomes. From these results, it can be said that single-crystal indium oxide is a substance having physical properties close to silicon, unlike IGZO. Note that when indium oxide is non-single-crystal (for example, polycrystalline), the tendency may differ from that of single crystal.

[0282] The preferred carrier concentration range for the channel formation region of a transistor is 1×10 １５ cm −３ , for example a range including 1×10 １４ cm −３ or more and 1×10 １８ cm −３ or less. By sufficiently reducing the carrier concentration, the hole mobility value can be expected to be increased to about 270 cm ２ / (V·s).

[0283] An element that reduces carrier concentration can be contained in indium oxide. Examples of the element that reduces carrier concentration include magnesium, calcium, zinc, cadmium, and copper. The carrier concentration can be lowered by substitution of these elements for indium. Other examples include nitrogen, phosphorus, arsenic, and antimony. The carrier concentration can be lowered by substitution of these elements for oxygen.

[0284] The element that reduces carrier concentration can also be referred to as an element that imparts p-type conductivity. Adding an element that reduces carrier concentration to an indium oxide film may facilitate making the indium oxide film i-type or substantially i-type in some cases. In this case, the concentration of the element that reduces the carrier concentration in the indium oxide film is 1×10 １６ atoms / cm ３ or more and 8×10 ２０ atoms / cm ３ or less, preferably 1×10 １６atoms / cm ３ The above 4 x 10 ２０ atoms / cm ３ The following is more preferable: 1 × 10 １６ atoms / cm ３ The above 8 x 10 １９ atoms / cm ３ The following is more preferable: 1 × 10 １６ atoms / cm ３ The above 5 x 10 １９ atoms / cm ３ The following is even more preferable. By using such concentrations, the carrier concentration can be reduced while maintaining the crystal structure of indium oxide.

[0285] On the other hand, electrical resistance can be reduced by increasing the carrier concentration. For example, the suitable carrier concentration range for the source and drain regions of a transistor, or for a resistor or transparent conductive film, is when the carrier concentration value is 1 × 10⁻⁶ ２０ cm −３ This range includes, for example, 1 × 10 １９ cm −３ The above is 1 x 10 ２２ cm −３ The range is as follows: By making the carrier concentration sufficiently high, the resistivity can be increased to 1 × 10⁻⁶. −４ It is expected that the level can be reduced to below Ω·cm.

[0286] Indium oxide may contain elements that increase the carrier concentration. For example, it is preferable to include elements common to the source and drain electrodes of the transistor. Examples of elements that increase the carrier concentration include titanium, zirconium, hafnium, tantalum, tungsten, molybdenum, tin, silicon, and boron. In particular, it is more preferable to use elements in which the oxide is conductive or semiconducting.

[0287] Elements that increase carrier concentration can also be called elements that confer n-type properties. The concentration of the above-mentioned carrier-increasing elements in an indium oxide film is 1 × 10⁻⁶ １６ atoms / cm ３ The above 8 x 10 ２０ atoms / cm ３ The following is preferable: 1 × 10 １６atoms / cm ３ The above 4 x 10 ２０ atoms / cm ３ The following is more preferable: 1 × 10 １６ atoms / cm ３ The above 8 x 10 １９ atoms / cm ３ The following is more preferable: 1 × 10 １６ atoms / cm ３ The above 5 x 10 １９ atoms / cm ３ The following is even more preferable. By using such concentrations, the carrier concentration can be increased while maintaining the crystal structure of indium oxide. Antimony can also function as an element that increases the carrier concentration.

[0288] Because indium oxide is an oxide whose valence electrons can be controlled, the threshold voltage of a transistor using a semiconductor layer containing indium oxide can be controlled. Furthermore, regions with low carrier concentrations can be used for the channel formation region of the transistor, and regions with high carrier concentrations can be used for the source and drain regions of the transistor. This makes it possible to create a so-called n-i-n junction (a junction between an n-type region, an i-type region, and an n-type region). Valence electron control in transistors using silicon is generally known. On the other hand, valence electron control in transistors using indium oxide is a novel technological concept that would not normally be conceived. By using this technological concept, it is possible to realize a transistor with high mobility, low off-current, normally-off capability, and high reliability.

[0289] The indium oxide film is preferably crystalline. In particular, the indium oxide film is preferably polycrystalline, and more preferably single-crystal. A single-crystal film does not have grain boundaries. By using a single-crystal film, carrier scattering at grain boundaries can be suppressed, enabling the realization of transistors that exhibit high field-effect mobility. Furthermore, it has the excellent effect of suppressing variations in transistor characteristics caused by these grain boundaries.

[0290] Furthermore, polycrystalline films are preferable because they can reduce carrier scattering and exhibit high field-effect mobility compared to microcrystalline or amorphous films. When using polycrystalline films, it is preferable to use films with the largest possible grain size and few grain boundaries. In a transistor to which a polycrystalline film is applied, if there are no grain boundaries in the channel formation region, or if no grain boundaries are observed, the channel formation region is located within the single-crystal region contained in the polycrystalline film, and therefore it can be considered a transistor to which a single-crystal film is applied.

[0291] The crystallinity of indium oxide can be analyzed, for example, by X-ray diffraction (XRD), transmission electron microscopy (TEM), or electron diffraction (ED). Alternatively, a combination of these methods may be used for analysis.

[0292] Furthermore, in this specification, a semiconductor layer in which no grain boundaries are observed in the channel formation region, a semiconductor layer in which the channel formation region is contained within a single crystal grain, or a semiconductor layer in which the crystal axis directions are the same in at least two regions within the channel formation region can be considered as a single crystal film.

[0293] The channel formation region refers to the region of the semiconductor layer that overlaps with (or faces) the gate electrode via the gate insulating layer, and is located between the region in contact with the source electrode and the region in contact with the drain electrode. The crystal grains, grain boundaries, crystal axes, and crystal orientation in the channel formation region can be confirmed by cross-sectional observation including the semiconductor layer, source electrode, and drain electrode.

[0294] Impurities in the indium oxide film can act as a source of carrier scattering, thus potentially causing a decrease in field-effect mobility and inhibiting crystal growth. Examples of impurities in the indium oxide film include boron and silicon. In the channel-forming region of the indium oxide film, lower concentrations of these impurities are preferable. For example, the concentration of each of the above impurity elements should be 0.1% or less, more preferably 0.01% (100 ppm) or less. Note that elements such as carbon and hydrogen may be present in the deposition gas or precursor during film formation, and may remain in the indium oxide film in higher concentrations than the above impurities.

[0295] Furthermore, the indium oxide film may contain elements that can become trivalent cations like indium, as long as their crystals maintain a cubic crystal structure (Bixbite type). Examples include Group 13 elements of the periodic table such as gallium and aluminum, and Group 3 elements of the periodic table. Since the bonding force of these elements is stronger than that of indium and oxygen, adding these elements to the indium oxide film can reduce oxygen vacancies (V) in the indium oxide film. Ｏ This can suppress the formation of ions. Furthermore, since these elements mainly exist as trivalent cations in the oxide, the carrier concentration of the indium oxide film can be kept low. Therefore, it becomes possible to shift the threshold voltage of the transistor to the positive side. Also, normally-off operation becomes possible. Thus, a transistor with good electrical characteristics can be provided.

[0296] The concentration of the above elements in the indium oxide film is 1 × 10⁻⁶ １６ atoms / cm ３ The above 8 x 10 ２０ atoms / cm ３ The following is preferable: 1 × 10 １６ atoms / cm ３ The above 4 x 10 ２０ atoms / cm ３ The following is more preferable: 1 × 10 １６ atoms / cm ３ The above 8 x 10 １９ atoms / cm ３ The following is more preferable: 1 × 10 １６ atoms / cm３ The above 5 x 10 １９ atoms / cm ３ The following are even more preferable.

[0297] Furthermore, the elements that impart n-type, p-type, and trivalent cations mentioned above can be added to the indium oxide film by methods such as ion doping, ion implantation, and thermal diffusion. Alternatively, the elements that impart n-type, p-type, and trivalent cations mentioned above can be added to the sputtering target, deposition gas, ALD deposition precursor, etc., when depositing the indium oxide film. Alternatively, the elements that impart n-type, p-type, and trivalent cations mentioned above can be auto-doped from the chamber used when depositing the indium oxide film. Auto-doping refers to the automatic addition of elements contained in the chamber components, etc., into the indium oxide film during deposition.

[0298] By using such an indium oxide film in a transistor, the field-effect mobility of the transistor can be increased to 50 cm². ２ / (V·s) or more, preferably 100 cm ２ / (V·s) or more, more preferably 150 cm ２ / (V·s) or more, more preferably 200 cm ２ / (V·s) or more, more preferably 250 cm ２ It can be set to (V・s) or more.

[0299] One of the characteristics of indium oxide films is their higher oxygen permeability (diffusivity) compared to IGZO films. For example, oxygen diffusing into an indium oxide film permeates the film and is released as oxygen molecules. In some cases, it may also be released as water molecules by reacting with hydrogen contained in the film. Furthermore, if there is an oxygen deficiency in the film, diffusing oxygen atoms will fill the deficiency. Because oxygen diffuses easily through indium oxide films, it can be said that oxygen deficiencies are more easily filled in compared to IGZO films.

[0300] Thus, because indium oxide films are more likely to reduce oxygen vacancies in the film compared to IGZO films, applying such indium oxide films to transistors makes it possible to realize transistors with extremely high reliability.

[0301] Furthermore, the indium oxide film diffuses hydrogen. Hydrogen diffusing into the indium oxide film from the outside permeates the film and is released as hydrogen molecules. Alternatively, it reacts with oxygen contained in the film and is released as water molecules.

[0302] Indium oxide is characterized by a small effective electron mass and a large effective hole mass. Furthermore, the effective electron mass of indium oxide is largely independent of the crystal orientation. Therefore, using crystalline indium oxide in transistors allows for the realization of transistors with high field-effect mobility and high frequency characteristics (also known as f-response). Moreover, due to the large effective hole mass, transistors with extremely low off-currents can be realized. For example, by applying an indium oxide film to a transistor, the off-current per 1 μm of channel width is 1 fA (1 × 10⁻¹⁶) at 125°C. −１５ A) Less than or equal to, or 1aA (1 × 10 −１８ A) Less than or equal to 1aA (1 × 10) in a room temperature (25°C) environment. −１８ A) Less than or equal to, or 1zA (1 × 10⁻¹⁰ −２１ A) The following is possible. Furthermore, because indium oxide has a smaller effective electron mass and a larger effective hole mass than silicon, it may be possible to realize transistors with higher field-effect mobility and lower off-current than Si transistors.

[0303] It is preferable to provide a seed layer so as to be in contact with at least a portion of the crystalline indium oxide film. It is preferable to use a material containing crystals with a small difference in lattice constant (also called lattice mismatch) with the indium oxide for the seed layer. This improves the crystallinity of the indium oxide film. A substrate (e.g., a single-crystal substrate) may be used as one of the layers in contact with at least a portion of the crystalline indium oxide film.

[0304] One method for evaluating the degree of lattice mismatch is to use the following lattice mismatch value. The lattice mismatch Δa [%] of the crystals in the formed film (in this case, the indium oxide film) relative to the crystals in the seed layer is given by Δa = ((L １ -L ２ ) / L ２ It is calculated as ) × 100. Here L １ L is the length of the unit cell vector of the crystals in the formed film, or the lattice constant. ２ This is the length of the unit cell vector of the crystal in the seed layer, or the lattice constant.

[0305] The lattice mismatch Δa between the seed layer and the indium oxide film is preferably small in absolute value, and most preferably zero. For example, Δa can be -5% or more and 5% or less, preferably -4% or more and 4% or less, more preferably -3% or more and 3% or less, and even more preferably -2% or more and 2% or less.

[0306] Here, the indium oxide crystal has a cubic structure (bixbite type). For example, yttria-stabilized zirconia (YSZ) crystals can have a cubic structure (fluorite type). The lattice mismatch of the indium oxide crystal with respect to the cubic YSZ crystal is in the range of -2% to 2%, and a single crystal film of indium oxide can be epitaxially grown on a YSZ substrate.

[0307] Furthermore, the crystal structure of the seed layer and the crystal structure of the indium oxide film do not necessarily have to be the same in terms of crystal system or crystal orientation. For example, a film with a hexagonal or trigonal crystal structure can be used beneath an indium oxide film with a cubic crystal structure. For example, by setting the crystal orientation of the surface of the seed layer to

[001] and the crystal orientation of the underside of the indium oxide film to

[111] , the requirements related to crystal orientation necessary for epitaxial growth can be met. Examples of hexagonal or trigonal crystals include wurtzite-type structures and YbFe. ２ O ４ Type structure, Yb ２ Fe ３ O ７ These include type structures and their modified type structures. YbFe ２ O４ Type structure or Yb ２ Fe ３ O ７ An example of a crystal having a type structure is IGZO.

[0308] This embodiment can be implemented in appropriate combination with other embodiments described herein, at least in part.

[0309] (Embodiment 3) This embodiment describes an example of the configuration of a display device according to one aspect of the present invention.

[0310] 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 sets, 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, smartphones, smartwatches, tablet devices, personal digital assistants, and audio playback devices.

[0311] [Display device 400A] Figure 16 shows a perspective view of the display device 400A, and Figure 17 shows a cross-sectional view of the display device 400A.

[0312] The display device 400A has a configuration in which substrate 452 and substrate 451 are bonded together. In Figure 16, substrate 452 is clearly indicated by a dashed line.

[0313] The display device 400A includes a display unit 462, a circuit 464, wiring 465, etc. Figure 16 shows an example in which IC 473 and FPC 472 are mounted on the display device 400A. Therefore, the configuration shown in Figure 16 can also be described as a display module having the display device 400A, an IC (integrated circuit), and an FPC.

[0314] For example, a scan line drive circuit can be used as circuit 464.

[0315] The wiring 465 has the function of supplying signals and power to the display unit 462 and the circuit 464. These signals and power are input to the wiring 465 from an external source via the FPC 472, or from the IC 473.

[0316] Figure 16 shows an example in which IC 473 is provided on the substrate 451 using the COG (Chip On Glass) method or the COF (Chip On Film) method. IC 473 can be an IC having, for example, a scan line drive circuit or a signal line drive circuit. Note that the display device 400A and the display module may be configured without an IC. Alternatively, the IC may be mounted on the FPC using the COF method or the like.

[0317] Figure 17 shows an example of a cross-section obtained by cutting a portion of the display device 400A, including the FPC 472, a portion of the circuit 464, a portion of the display unit 462, and a portion of the area including the end.

[0318] The display device 400A shown in Figure 17 has, between substrates 451 and 452, a transistor 201, a transistor 205, a plurality of light-emitting elements 430 that emit light including blue light, a wavelength conversion layer 414R that converts light to red, a wavelength conversion layer 414G that converts wavelength to green, a red color filter 415R, and a green color filter 415G, etc.

[0319] The light-emitting element 430 can be the light-emitting element illustrated in Embodiment 1. Each light-emitting element 430 has a pixel electrode 411a, a pixel electrode 411b, or a pixel electrode 411c, an island-shaped EL layer, and an island-shaped upper electrode.

[0320] Here, if the pixels of the display device have three types of subpixels that emit light of different colors, examples of such three subpixels include subpixels of three colors: R, G, and B; and subpixels of three colors: yellow (Y), cyan (C), and magenta (M). If there are four such subpixels, examples of such four subpixels include subpixels of four colors: R, G, B, and Y; subpixels of four colors: R, G, B, and white (W); and subpixels of R, G, B, and infrared (IR).

[0321] The protective layer 416 and the substrate 452 are bonded together via an adhesive layer 442. For sealing the light-emitting element, a solid sealing structure or a hollow sealing structure can be applied. In Figure 17, the space 443 surrounded by the substrate 452, the adhesive layer 442, and the substrate 451 is filled with an inert gas (such as nitrogen or argon), and a hollow sealing structure is applied. The adhesive layer 442 may be provided overlapping the light-emitting element. Alternatively, the space 443 surrounded by the substrate 452, the adhesive layer 442, and the substrate 451 may be filled with a resin different from that of the adhesive layer 442.

[0322] The light-emitting element 430 has an optical adjustment layer 426 between the pixel electrode and the EL layer. The light-emitting element 430 for red pixels has an optical adjustment layer 426a, the light-emitting element 430 for green pixels has an optical adjustment layer 426b, and the light-emitting element 430 for blue pixels has an optical adjustment layer 426c. Details of the light-emitting element can be found in Embodiment 1. By making the optical adjustment layer 426 of different thicknesses, the cavity length of the microcavity can be changed, and the wavelength of light that is amplified can be changed. By making each optical adjustment layer 426 of different thicknesses for each pixel, the wavelength of light that is amplified can be changed. As an example, Figure 17 shows a display device according to one embodiment of the present invention in which light-emitting elements 430 that emit the same color are used for each pixel, and therefore the optical adjustment layer 426 is of the same thickness for each pixel. Furthermore, it is preferable that each optical adjustment layer 426 is made of the same material that has light transmission and conductivity. It is preferable that a conductive metal oxide film containing indium or zinc is used as the optical adjustment layer 426. Figure 18 also shows examples where the thickness of the optical adjustment layer 426 is different.

[0323] The pixel electrodes 411a, 411b, and 411c are each connected to the conductive layer 222b of the transistor 205 through an opening provided in the insulating layer 214.

[0324] The edges of the pixel electrodes and the optical adjustment layer are covered by an insulating layer 421. The pixel electrodes contain a material that reflects visible light, and the counter electrodes contain a material that transmits visible light.

[0325] The light emitted by the light-emitting element 430 is emitted towards the substrate 452. Furthermore, if a wavelength conversion layer 414 and a color filter are provided on the light-emitting element 430, the light emitted by the light-emitting element 430 is emitted towards the substrate 452 via the wavelength conversion layer 414 and the color filter 415. It is preferable to use a material with high transmittance to visible light for the substrate 452.

[0326] A partition wall 420 is provided on the insulating layer 421. The partition wall 420 can be described by referring to the partition wall 120 shown in Embodiment 1. The partition wall 420 is provided in a region that overlaps with the light-shielding layer 417. On the partition wall 420, a layer is provided which includes a part of the upper electrodes of two adjacent light-emitting elements on either side of the partition wall 420, and the same material as the EL layer. In addition, a protective layer 416 is provided covering the partition wall 420.

[0327] Both transistors 201 and 205 are formed on the substrate 451. These transistors can be manufactured using the same materials and the same process.

[0328] On the substrate 451, 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.

[0329] 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.

[0330] It is preferable to use inorganic insulating films for insulating layers 211, 213, and 215. Examples of inorganic insulating films that can be used include silicon nitride, silicon oxide nitride, silicon oxide, silicon nitride, aluminum oxide, and aluminum nitride. Alternatively, hafnium oxide, yttrium oxide, zirconium oxide, gallium oxide, tantalum oxide, magnesium oxide, lanthanum oxide, cerium oxide, and neodymium oxide may also be used. Furthermore, two or more of the above insulating films may be laminated together.

[0331] Here, organic insulating films often have lower barrier properties than inorganic insulating films. Therefore, it is preferable that the organic insulating film has an opening near the edge of the display device 400A. This prevents impurities from entering through the organic insulating film from the edge of the display device 400A. Alternatively, the organic insulating film may be formed so that its edge is inward from the edge of the display device 400A, so that the organic insulating film is not exposed at the edge of the display device 400A.

[0332] An organic insulating film is preferred for the insulating layer 214, which functions as a planarizing layer. Examples of materials that can be used as the organic insulating film include acrylic resins, polyimide resins, epoxy resins, polyamide resins, polyimidoamide resins, siloxane resins, benzocyclobutene resins, phenolic resins, and precursors of these resins.

[0333] In the region 228 shown in Figure 17, an opening is formed in the insulating layer 214. This prevents impurities from entering the display unit 462 from the outside through the insulating layer 214, even when an organic insulating film is used for the insulating layer 214. Therefore, the reliability of the display device 400A can be improved.

[0334] 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.

[0335] 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.

[0336] 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.

[0337] The crystallinity of the semiconductor material used in the transistor is not particularly limited; amorphous semiconductors, single-crystal semiconductors, or semiconductors with crystalline properties other than single crystals (microcrystalline semiconductors, polycrystalline semiconductors, or semiconductors with crystalline regions in part) may be used. Using a single-crystal semiconductor or a semiconductor with crystalline properties is preferable because it can suppress the degradation of transistor characteristics.

[0338] The semiconductor layer of the transistor preferably has a metal oxide (also called an oxide semiconductor). In other words, the display device of this embodiment preferably uses a transistor (hereinafter referred to as an OS transistor) that uses a metal oxide in the channel formation region. Alternatively, the semiconductor layer of the transistor may have silicon. Examples of silicon include amorphous silicon and crystalline silicon (low-temperature polysilicon, single-crystal silicon, etc.).

[0339] The semiconductor layer preferably contains a metal oxide containing indium. In particular, it is especially preferable that it contains indium oxide.

[0340] Furthermore, the semiconductor layer preferably comprises, for example, indium, M (where M is one or more selected from gallium, aluminum, silicon, boron, yttrium, tin, copper, vanadium, beryllium, titanium, iron, nickel, germanium, zirconium, molybdenum, lanthanum, cerium, neodymium, hafnium, tantalum, tungsten, and magnesium), and zinc. In particular, M is preferably one or more selected from aluminum, gallium, yttrium, and tin.

[0341] In particular, it is preferable to use an oxide (also written as IGZO) containing indium (In), gallium (Ga), and zinc (Zn) as the semiconductor layer.

[0342] 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 equal to or greater than the atomic ratio of M. Examples of such In-M-Zn oxide atomic ratios of metal elements include compositions where In:M:Zn = 1:1:1 or nearby, In:M:Zn = 1:1:1.2 or nearby, In:M:Zn = 2:1:3 or nearby, In:M:Zn = 3:1:2 or nearby, In:M:Zn = 4:2:3 or nearby, In:M:Zn = 4:2:4.1 or nearby, In:M:Zn = 5:1:3 or nearby, In:M:Zn = 5:1:6 or nearby, In:M:Zn = 5:1:7 or nearby, In:M:Zn = 5:1:8 or nearby, In:M:Zn = 6:1:6 or nearby, In:M:Zn = 5:2:5 or nearby, and so on. Note that "nearby composition" includes a range of ±30% of the desired atomic ratio.

[0343] For example, when the atomic ratio is stated as In:Ga:Zn = 4:2:3 or nearby, it includes cases where, with In set to 4, Ga is between 1 and 3, and Zn is between 2 and 4. Also, when the atomic ratio is stated as In:Ga:Zn = 5:1:6 or nearby, it includes cases where, with In set to 5, Ga is greater than 0.5 and 2 or less, and Zn is between 5 and 7. Furthermore, when the atomic ratio is stated as In:Ga:Zn = 1:1:1 or nearby, it includes cases where, with In set to 1, Ga is greater than 0.5 and 2 or less, and Zn is greater than 0.5 and 2 or less.

[0344] The transistors in circuit 464 and the transistors in display unit 462 may have the same structure or different structures. The structures of the multiple transistors in circuit 464 may all be the same or there may be two or more different structures. Similarly, the structures of the multiple transistors in display unit 462 may all be the same or there may be two or more different structures.

[0345] A connection portion 204 is provided in the region of substrate 451 where substrate 452 does not overlap. At the connection portion 204, wiring 465 is electrically connected to FPC 472 via a conductive layer 466 and a connecting layer 242. The conductive layer 466 is shown as an example of a laminated structure consisting of a conductive film obtained by processing the same conductive film as the pixel electrode and a conductive film obtained by processing the same conductive film as the optical adjustment layer. The conductive layer 466 is exposed on the upper surface of the connection portion 204. This allows the connection portion 204 and FPC 472 to be electrically connected via the connecting layer 242.

[0346] It is preferable to provide a light-shielding layer 417 on the surface of the substrate 452 that faces the substrate 451. Various optical components can also be arranged on the outside of the substrate 452. 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, an antistatic film to suppress the adhesion of dust, a water-repellent film to make it difficult for dirt to adhere, a hard coat film to suppress the occurrence of scratches during use, and an impact-absorbing layer may also be arranged on the outside of the substrate 452.

[0347] By providing a protective layer 416 that covers the light-emitting element, it is possible to suppress the entry of impurities such as water into the light-emitting element and improve the reliability of the light-emitting element.

[0348] In the region 228 near the edge of the display device 400A, it is preferable that the insulating layer 215 and the protective layer 416 are in contact with each other through an opening in the insulating layer 214. In particular, it is preferable that the inorganic insulating film of the insulating layer 215 and the inorganic insulating film of the protective layer 416 are in contact with each other. This makes it possible to suppress impurities from entering the display unit 462 from the outside through the organic insulating film. Therefore, the reliability of the display device 400A can be improved.

[0349] The protective layer 416 may have a laminated structure of an organic insulating film and an inorganic insulating film. In this case, it is preferable that the edges of the inorganic insulating film extend outward more than the edges of the organic insulating film.

[0350] For each of the substrate 451 and the substrate 452, glass, quartz, ceramics, sapphire, resin, metal, alloy, semiconductor, or the like can be used. For the substrate on the side from which light from the light-emitting element is extracted, a material that transmits the light is used. When a flexible material is used for the substrate 451 and the substrate 452, the flexibility of the display device can be increased. Alternatively, a polarizing plate may be used as the substrate 451 or the substrate 452.

[0351] For each of the substrate 451 and the substrate 452, polyester resins such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN), polyacrylonitrile resins, acrylic resins, polyimide resins, polymethyl methacrylate resins, polycarbonate (PC) resins, polyethersulfone (PES) resins, polyamide resins (nylon, aramid, etc.), polysiloxane resins, cycloolefin resins, polystyrene resins, polyamide-imide resins, polyurethane resins, polyvinyl chloride resins, polyvinylidene chloride resins, polypropylene resins, polytetrafluoroethylene (PTFE) resins, ABS resins, cellulose nanofibers, or the like can be used. For one or both of the substrate 451 and the substrate 452, glass having a thickness that allows flexibility may be used.

[0352] Note that in the case where a circularly polarizing plate is stacked over the display device, a substrate with high optical isotropy is preferably used as a substrate included in the display device. The substrate with high optical isotropy has low birefringence (can also be said to have a small birefringence amount).

[0353] The absolute value of the retardation (phase difference) value of the substrate with high optical isotropy is preferably 30 nm or less, more preferably 20 nm or less, and even more preferably 10 nm or less.

[0354] Examples of the film with high optical isotropy include a triacetyl cellulose (TAC, also referred to as cellulose triacetate) film, a cycloolefin polymer (COP) film, a cycloolefin copolymer (COC) film, an acrylic film, and the like.

[0355] Further, when a film is used as the substrate, water absorption by the film may cause a shape change such as wrinkling in the display panel. Therefore, it is preferable to use a film with low water absorption for the substrate. For example, it is preferable to use a film having a water absorption rate of 1% or less, more preferable to use a film having a water absorption rate of 0.1% or less, and even more preferable to use a film having a water absorption rate of 0.01% or less.

[0356] As the adhesive layer, various curable adhesives such as photocurable adhesives including ultraviolet curable adhesives, reaction curable adhesives, thermosetting adhesives, and anaerobic adhesives can be used. 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, EVA (ethylene vinyl acetate) resins, and the like. In particular, materials with low moisture permeability such as epoxy resins are preferred. Further, a two-part mixed type resin may be used. Moreover, an adhesive sheet or the like may be used.

[0357] As the connection layer 242, an anisotropic conductive film (ACF: Anisotropic Conductive Film), an anisotropic conductive paste (ACP: Anisotropic Conductive Paste), or the like can be used.

[0358] Examples of materials that can be used for conductive layers such as various wirings and electrodes constituting the display device, in addition to the gate, source, and drain of the transistor, include metals such as aluminum, titanium, chromium, nickel, copper, yttrium, zirconium, molybdenum, silver, tantalum, and tungsten, as well as alloys containing the metals as main components. Films containing these materials can be used as a single layer or as a laminated structure.

[0359] Furthermore, conductive oxides such as indium oxide, indium tin oxide, indium zinc oxide, zinc oxide, and zinc oxide containing gallium, or graphene can be used as the light-transmitting conductive material. Alternatively, metallic materials such as gold, silver, platinum, magnesium, nickel, tungsten, chromium, molybdenum, iron, cobalt, copper, palladium, and titanium, or alloy materials containing such metallic materials, can be used. Alternatively, nitrides of such metallic materials (e.g., titanium nitride) may be used. When using metallic materials or alloy materials (or their nitrides), it is preferable to make them thin enough to be light-transmitting. In addition, a laminated film of the above materials can be used as a conductive layer. For example, using a laminated film of a silver-magnesium alloy and indium tin oxide is preferable because it can enhance conductivity. These can also be used for conductive layers of various wirings and electrodes that constitute a display device, and for conductive layers of light-emitting elements (conductive layers that function as pixel electrodes or common electrodes).

[0360] Examples of insulating materials that can be used for each insulating layer include resins such as acrylic resin and epoxy resin, and inorganic insulating materials such as silicon oxide, silicon oxide nitride, silicon nitride, silicon oxide, and aluminum oxide.

[0361] [Display Device 400B] Figure 19A shows a cross-sectional view of the display device 400B. The perspective view of the display device 400B is the same as that of the display device 400A (Figure 16). Figure 19A shows an example of a cross-section of the display device 400B when a part of the area including the FPC 472, a part of the circuit 464, and a part of the display unit 462 are cut. In Figure 19A, an example of a cross-section is shown when a part of the display unit 462, in particular, including the light-emitting element 430 provided on the green pixels and the light-emitting element 430 provided on the blue pixels, is cut. Note that explanations of parts that are the same as those of the display device 400A may be omitted.

[0362] The display device 400B shown in Figure 19A has a transistor 202, a transistor 210, a light-emitting element 430, a wavelength conversion layer 414G, a color filter 415G, etc., between substrates 453 and 454.

[0363] The substrate 454 and the protective layer 416 are bonded together via an adhesive layer 442. The adhesive layer 442 is provided in overlapping place with each light-emitting element 430, and a solid encapsulation structure is applied to the display device 400B.

[0364] The substrate 453 and the insulating layer 212 are bonded together by an adhesive layer 455.

[0365] The wavelength conversion layer 414G is provided at the opening of the separation layer 413. In the configuration shown in Figure 19A, an opening in the separation layer 413 is also provided in the region overlapping with the light-emitting element 430 provided in the blue pixel, and layer 412 is provided at this opening. Layer 412 has the function of transmitting visible light. Preferably, layer 412 has the function of scattering light, for example. Alternatively, the separation layer 413 may also have the function of scattering light.

[0366] The method for manufacturing the display device 400B involves first bonding a fabricated substrate, on which an insulating layer 212, transistors, and light-emitting elements are provided, to a substrate 454 on which a light-shielding layer 417 is provided, using an adhesive layer 442. Then, the fabricated substrate is peeled off and a substrate 453 is attached to the exposed surface, thereby transferring the components formed on the fabricated substrate to the substrate 453. It is preferable that both the substrate 453 and the substrate 454 are flexible. This increases the flexibility of the display device 400B.

[0367] The insulating layer 212 can be made of an inorganic insulating film that can be used for insulating layer 211, insulating layer 213, and insulating layer 215, respectively.

[0368] The pixel electrodes are connected to the conductive layer 222b of the transistor 210 through an opening in the insulating layer 214. The conductive layer 222b is connected to the low-resistance region 231n through openings in the insulating layers 215 and 225. The transistor 210 has the function of controlling the driving of the light-emitting element.

[0369] The ends of the pixel electrodes are covered by an insulating layer 421.

[0370] The light emitted by the light-emitting element 430 is emitted toward the substrate 454. Furthermore, if a wavelength conversion layer 414 and a color filter are provided on the light-emitting element 430, the light emitted by the light-emitting element 430 is emitted toward the substrate 454 via the wavelength conversion layer 414 and the color filter 415. It is preferable to use a material with high transmittance to visible light for the substrate 454.

[0371] A connection portion 204 is provided in the region of substrate 453 that does not overlap with substrate 454. At the connection portion 204, wiring 465 is electrically connected to FPC 472 via a conductive layer 466 and a connecting layer 242. The conductive layer 466 can be obtained by processing the same conductive film as the pixel electrode. This allows the connection portion 204 and FPC 472 to be electrically connected via the connecting layer 242.

[0372] Transistors 202 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 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 between the conductive layer 223 and the channel forming region 231i.

[0373] The conductive layer 222a and the conductive layer 222b are each connected to the low-resistance region 231n via openings provided in the insulating layer 215. Of the conductive layer 222a and the conductive layer 222b, one functions as a source and the other functions as a drain.

[0374] Figure 19A shows an example in which the insulating layer 225 covers the top and side surfaces of the semiconductor layer. The conductive layer 222a and the conductive layer 222b are connected to the low-resistance region 231n through openings provided in the insulating layer 225 and the insulating layer 215, respectively.

[0375] On the other hand, in the transistor 209 shown in Figure 19B, 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 19B can be fabricated by processing the insulating layer 225 using the conductive layer 223 as a mask. In Figure 19B, 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. Furthermore, an insulating layer 218 covering the transistor may also be provided.

[0376] The configuration examples illustrated in this embodiment, and the corresponding drawings, etc., can be appropriately combined with other configuration examples or drawings, etc., at least in part.

[0377] This embodiment can be implemented in appropriate combination with other embodiments described herein, at least in part.

[0378] (Embodiment 4) In this embodiment, an example of a display device configuration different from that described above will be explained.

[0379] The display device of this embodiment can be a high-definition display device. Therefore, the display device of this embodiment can be used in the display section of wearable devices that can be worn on the head, such as information terminals (wearable devices) such as wristwatches and bracelets, as well as VR devices such as head-mounted displays and AR devices such as glasses.

[0380] [Display Module] Figure 20A shows a perspective view of the display module 280. The display module 280 includes a display device 400C and an FPC 290. Note that the display device included in the display module 280 is not limited to the display device 400C, but may be the display device 400D or the display device 400E described later.

[0381] 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.

[0382] Figure 20B shows a schematic perspective view illustrating the configuration of the substrate 291. On the substrate 291, a circuit section 282, a pixel circuit section 283 on the circuit section 282, and a pixel section 284 on the pixel circuit section 283 are stacked. In addition, a terminal section 285 for connecting to the FPC 290 is provided in the portion of the substrate 291 that does not overlap with the pixel section 284. The terminal section 285 and the circuit section 282 are electrically connected by a wiring section 286 composed of multiple wires.

[0383] The pixel section 284 has a plurality of pixels 284a arranged periodically. A magnified view of one pixel 284a is shown on the right side of Figure 20B. Pixel 284a has pixels 430a, 430b, and 430c of different colors. The plurality of pixels may be arranged in a stripe arrangement as shown in Figure 20B. A stripe arrangement allows for a high-density arrangement of pixel circuits, thus providing a high-definition display device. Furthermore, various arrangement methods such as delta arrangement and pentile arrangement can be applied.

[0384] The pixel circuit section 283 has a plurality of pixel circuits 283a arranged periodically.

[0385] A single pixel circuit 283a is a circuit that controls the light emission of the three light-emitting elements of a single pixel 284a. A single pixel circuit 283a may be configured to have three circuits that control the light emission of a single light-emitting element. For example, a single pixel circuit 283a may have at least one selection transistor, one current control transistor (drive transistor), and a capacitive element for each light-emitting element. In this case, a gate signal is input to the gate of the selection transistor, and a source signal is input to either the source or the drain. This realizes an active-matrix type display device.

[0386] 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.

[0387] The FPC 290 functions as a wiring for supplying a video signal, a power supply potential, or the like from the outside to the circuit portion 282. Further, an IC may be mounted over the FPC 290.

[0388] The display module 280 can have a structure in which one or both of the pixel circuit portion 283 and the circuit portion 282 are provided to overlap under the pixel portion 284, so that the aperture ratio (effective display area ratio) of the display portion 281 can be made extremely high. For example, the aperture ratio of the display portion 281 can be 40% or more and less than 100%, preferably 50% or more and 95% or less, more preferably 60% or more and 95% or less. Further, the pixels 284a can be arranged at an extremely high density, and the definition of the display portion 281 can be made extremely high. For example, it is preferable that the pixels 284a be arranged in the display portion 281 with a definition of 2000 ppi or higher, preferably 3000 ppi or higher, more preferably 5000 ppi or higher, still more preferably 6000 ppi or higher, and 20000 ppi or lower, or 30000 ppi or lower.

[0389] Since such a display module 280 has extremely high definition, it can be suitably used for VR-oriented devices such as a head-mounted display, or glasses-type AR-oriented devices. For example, even in a configuration where the display portion of the display module 280 is viewed through a lens, since the display module 280 has the extremely high-definition display portion 281, pixels are not visually recognized even when the display portion is magnified by the lens, and display with high sense of immersion can be performed. Further, the display module 280 is not limited thereto, and can be suitably used for electronic devices having a relatively small display portion. For example, it can be suitably used for a display portion of a wearable electronic device such as a wristwatch.

[0390] [Display Device 400C] A display device 400C illustrated in FIG. 21 includes a substrate 301, a plurality of light-emitting elements 430, a capacitor 240, a wavelength conversion layer 414R, a wavelength conversion layer 414G, a color filter 415R, a color filter 415G, a transistor 310, and the like.

[0391] The substrate 301 corresponds to the substrate 291 in FIGS. 20A and 20B.

[0392] The transistor 310 is a transistor having a channel-forming region in the substrate 301. The substrate 301 can be a semiconductor substrate such as a single-crystal silicon substrate. The transistor 310 comprises a portion of the substrate 301, a conductive layer 311, a low-resistance region 312, an insulating layer 313, and an insulating layer 314. The conductive layer 311 functions as a gate electrode. The insulating layer 313 is located between the substrate 301 and the conductive layer 311 and functions as a gate insulating layer. The low-resistance region 312 is a region of the substrate 301 doped with impurities and functions as either a source or a drain. The insulating layer 314 is provided covering the side surface of the conductive layer 311.

[0393] Furthermore, an element isolation layer 315 is provided between two adjacent transistors 310 so as to be embedded in the substrate 301.

[0394] Furthermore, an insulating layer 261 is provided to cover the transistor 310, and a capacitance 240 is provided on the insulating layer 261.

[0395] The capacitor 240 has a conductive layer 241, a conductive layer 245, and an insulating layer 243 located between them. The conductive layer 241 functions as one electrode of the capacitor 240, the conductive layer 245 functions as the other electrode of the capacitor 240, and the insulating layer 243 functions as the dielectric of the capacitor 240.

[0396] The conductive layer 241 is provided on the insulating layer 261 and embedded in the insulating layer 254. The conductive layer 241 is electrically connected to either the source or drain of the transistor 310 by a plug 271 embedded in the insulating layer 261. The insulating layer 243 is provided covering the conductive layer 241. The conductive layer 245 is provided in the region that overlaps with the conductive layer 241 via the insulating layer 243.

[0397] An insulating layer 255 is provided covering the capacitance 240, and each light-emitting element 430, etc., is provided on the insulating layer 255. A protective layer 416 is provided on the light-emitting elements 430, and a substrate 401 is bonded to the upper surface of the protective layer 416 by a resin layer 419. The substrate 401 corresponds to the substrate 292 in Figure 20A.

[0398] The pixel electrodes of the light-emitting element are electrically connected to either the source or drain of the transistor 310 by plugs 256 embedded in the insulating layer 255, a conductive layer 241 embedded in the insulating layer 254, and plugs 271 embedded in the insulating layer 261.

[0399] An insulating layer 421 is provided to cover the ends of the pixel electrodes. It is preferable to use an inorganic insulating material for the insulating layer 421. For example, inorganic insulating materials such as silicon oxide, silicon nitride, and aluminum oxide can be used.

[0400] A partition wall 420 is provided on the insulating layer 421. The partition wall 420 can be described by referring to the description of the partition wall 120 shown in Embodiment 1. A layer containing a part of the upper electrode of the light-emitting element and the same material as the EL layer is provided on the partition wall 420.

[0401] [Display Device 400D] The display device 400D shown in Figure 22 differs from the display device 400C mainly in its transistor configuration. Note that explanations of parts similar to the display device 400C may be omitted.

[0402] Transistor 320 is a transistor in which a metal oxide (also called an oxide semiconductor) is applied to the semiconductor layer where the channel is formed.

[0403] 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.

[0404] The substrate 331 corresponds to the substrate 291 in Figures 20A and 20B. An insulating substrate or a semiconductor substrate can be used as the substrate 331.

[0405] An insulating layer 332 is provided on the substrate 331. The insulating layer 332 functions as a barrier layer that prevents impurities such as water or hydrogen from diffusing from the substrate 331 to the transistor 320, and prevents oxygen from detaching from the semiconductor layer 321 to the insulating layer 332. As the insulating layer 332, for example, a film that is less susceptible to hydrogen or oxygen diffusion than a silicon oxide film can be used, such as an aluminum oxide film, a hafnium oxide film, or a silicon nitride film.

[0406] A conductive layer 327 is provided on an insulating layer 332, and an insulating layer 326 is provided covering the conductive layer 327. The conductive layer 327 functions as the first gate electrode of the transistor 320, and a 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 is in contact with the semiconductor layer 321. It is preferable that the upper surface of the insulating layer 326 is flattened.

[0407] The semiconductor layer 321 is provided on the insulating layer 326. Preferably, the semiconductor layer 321 has a metal oxide (also called an oxide semiconductor) film having semiconductor properties. Details of materials that can be suitably used for the semiconductor layer 321 will be described later.

[0408] A pair of conductive layers 325 are provided in contact with the semiconductor layer 321 and function as source electrodes and drain electrodes.

[0409] Furthermore, an insulating layer 328 is provided covering the top and side surfaces of the pair of conductive layers 325, as well as the side surfaces of the semiconductor layer 321, and an insulating layer 264 is provided on the insulating layer 328. The insulating layer 328 functions as a barrier layer to prevent impurities such as water or hydrogen from diffusing into the semiconductor layer 321 from the insulating layer 264, etc., and to prevent oxygen from detaching from the semiconductor layer 321. An insulating film similar to that used for the insulating layer 332 can be used for the insulating layer 328.

[0410] The insulating layer 328 and the insulating layer 264 are provided with openings that reach the semiconductor layer 321. Inside these openings, the insulating layer 323 and the conductive layer 324 are embedded, in contact with the insulating layer 264, the insulating layer 328, the side surfaces of the conductive layer 325, and 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.

[0411] The upper surfaces of the conductive layer 324, the insulating layer 323, and the insulating layer 264 are flattened so that their heights are roughly the same, and the insulating layer 329 and insulating layer 265 are provided covering them.

[0412] Insulating layers 264 and 265 function as interlayer insulating layers. Insulating layer 329 functions as a barrier layer to prevent impurities such as water or hydrogen from diffusing into the transistor 320 from the insulating layer 265, etc. As insulating layer 329, an insulating film similar to that used for insulating layers 328 and 332 can be used.

[0413] 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 layer 265, insulating layer 329, and insulating layer 264. Here, it is preferable that the plug 274 has a conductive layer 274a that covers the sides of the openings of the insulating layer 265, insulating layer 329, insulating layer 264, and insulating layer 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.

[0414] The configuration from the insulating layer 254 to the substrate 401 in the display device 400D is the same as that of the display device 400C.

[0415] [Display Device 400E] The display device 400E 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. Note that the same parts as those of display devices 400C and 400D may be omitted from the explanation.

[0416] 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.

[0417] 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.

[0418] This configuration allows for the formation of not only pixel circuits but also drive circuits and other components directly beneath the light-emitting element, making it possible to miniaturize the display device compared to cases where the drive circuits are located around the display area.

[0419] The configuration examples illustrated in this embodiment, and the corresponding drawings, etc., can be appropriately combined with other configuration examples or drawings, etc., at least in part.

[0420] This embodiment can be implemented in appropriate combination with other embodiments described herein, at least in part.

[0421] (Embodiment 5) In this embodiment, a light-emitting element (also called a light-emitting device) that can be used in a display device according to one aspect of the present invention will be described.

[0422] 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 the layers (also called functional layers) of the EL layer include a light-emitting layer, a carrier injection layer (hole injection layer and electron injection layer), a carrier transport layer (hole transport layer and electron transport layer), and a carrier block layer (hole block layer and electron block layer).

[0423] In this specification, devices fabricated using a metal mask or FMM (Fine Metal Mask, a high-resolution metal mask) may be referred to as MM (Metal Mask) structured devices. In addition, in this specification, devices fabricated without using a metal mask or FMM may be referred to as MML (Metal Maskless) structured devices.

[0424] 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 blocking layer or electron blocking layer may be called a "carrier blocking layer." Note that the above-mentioned carrier injection layer, carrier transport layer, and carrier blocking layer may not always be clearly distinguishable. Furthermore, a single layer may combine the functions of two or three of the carrier injection layer, carrier transport layer, and carrier blocking layer.

[0425] [Light-emitting devices] Light-emitting devices can be broadly classified into single-structure and tandem-structure devices. A single-structure device has one light-emitting unit between a pair of electrodes. This light-emitting unit has a configuration that includes one or more light-emitting layers.

[0426] A tandem device has multiple light-emitting units between a pair of electrodes. Each light-emitting unit includes one or more light-emitting layers. By using light-emitting layers that emit light of the same color in each light-emitting unit, the brightness per given current can be increased, and a more reliable light-emitting device can be achieved compared to a single-layer structure. For example, multiple light-emitting units using light-emitting layers that emit blue light can be stacked.

[0427] Furthermore, a tandem device may have light-emitting units that emit light of different colors. For example, it may have one or more light-emitting units using a light-emitting layer that emits light of a first color, and one or more light-emitting units using a light-emitting layer that emits light of a second color. For example, it may have one or more units using a light-emitting layer that emits blue light, and one or more units using a light-emitting layer that emits green light. It may also have three or more light-emitting units of different colors.

[0428] In addition, in a tandem structure device, it is preferable to provide an intermediate layer, such as a charge generation layer, between multiple light-emitting units.

[0429] A structure in which different light-emitting layers are created or painted for each color of light-emitting device (here, blue (B), green (G), and red (R)) is sometimes called an SBS (Side By Side) structure. The SBS structure allows for optimization of materials and configuration for each light-emitting device, thus increasing the freedom of material and configuration selection and making it easier to improve brightness and reliability. However, because light-emitting devices of different colors are manufactured separately, the manufacturing process becomes more complex. A display device according to one aspect of the present invention can use only one type of light-emitting device, thereby lowering manufacturing costs and increasing manufacturing yield.

[0430] As shown in Figure 24A, 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.

[0431] The light-emitting layer 771 has at least a light-emitting substance (also called a light-emitting material).

[0432] 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.

[0433] A configuration having a layer 780, a light-emitting layer 771, and a layer 790 provided between a pair of electrodes can function as a single light-emitting unit, and in this specification, the configuration shown in Figure 24A is referred to as a single structure.

[0434] Furthermore, Figure 24B shows a modified example of the EL layer 763 of the light-emitting device shown in Figure 24A. Specifically, the light-emitting device shown in Figure 24B includes 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.

[0435] 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.

[0436] As shown in Figure 24C, a configuration in which multiple light-emitting layers (light-emitting layers 771, 772, 773) are provided between layer 780 and layer 790 is also a variation of the single structure. Although Figure 24C shows 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.

[0437] Furthermore, a single-layer light-emitting device may have a buffer layer between the two light-emitting layers.

[0438] Furthermore, as shown in Figures 24E and 24F, a configuration in which multiple light-emitting units (light-emitting units 763a and 763b) are connected in series via a charge generation layer 785 (also called an intermediate layer) is referred to as a tandem structure in this specification. The tandem structure may also be called a stack structure. By using a tandem structure, a light-emitting device capable of high-brightness emission can be created. In addition, compared to a single structure, the tandem structure can reduce the current required to obtain the same brightness, thereby improving reliability.

[0439] Figures 24D and 24F show examples in which the display device has layers 765 and 764 that overlap with the light-emitting device. Figure 24D shows an example in which layers 765 and 764 overlap with the light-emitting device shown in Figure 24C, and Figure 24F shows an example in which layers 765 and 764 overlap with the light-emitting device shown in Figure 24E. In Figures 24D and 24F, a conductive film that transmits visible light is used for the upper electrode 762 in order to extract light to the upper electrode 762 side.

[0440] A wavelength conversion layer can be used as layer 765. A color filter (coloring layer) can be used as layer 764.

[0441] Furthermore, layers 765, 764, etc., can be added to the light-emitting device shown in Figures 24B and 24C.

[0442] In Figure 24C, 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, the light-emitting layers 771, 772, and 773 may be made of light-emitting materials that emit blue light.

[0443] Furthermore, in Figure 24C, different light-emitting materials with different emission colors may be used for each of the light-emitting layers 771, 772, and 773. For example, one or more of the light-emitting layers 771, 772, and 773 may be made of a material that emits blue light, and the remaining light-emitting layers may be made of a material that emits green light.

[0444] In addition, as shown in Figure 24B, layer 780 and layer 790 may each be independently constructed as a laminated structure consisting of two or more layers.

[0445] Furthermore, in Figures 24E and 24F, 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. For example, in a light-emitting device having subpixels that emit light of each color, the light-emitting layer 771 and the light-emitting layer 772 may each be made of light-emitting materials that emit blue light.

[0446] Furthermore, in Figures 24E and 24F, different light-emitting materials with different emission colors may be used for the light-emitting layer 771 and the light-emitting layer 772. For example, a material that emits blue light may be used for one of the light-emitting layers 771 and 772, and a material that emits green light may be used for the other.

[0447] In Figures 24E and 24F, examples are shown in which the light-emitting unit 763a has one light-emitting layer 771 and the light-emitting unit 763b has one light-emitting layer 772, but the design is not limited to this. The light-emitting unit 763a and the light-emitting unit 763b may each have two or more light-emitting layers.

[0448] Furthermore, while Figures 24E and 24F illustrate a light-emitting device having two light-emitting units, the device is not limited to this. A light-emitting device may have three or more light-emitting units. The configuration with two light-emitting units may be referred to as a two-stage tandem structure, and the configuration with three light-emitting units may be referred to as a three-stage tandem structure.

[0449] Furthermore, in Figures 24E and 24F, 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.

[0450] 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.

[0451] When the lower electrode 761 is the anode and the upper electrode 762 is the cathode, for example, layer 780a may have 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. Layer 790a may have 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 may have a hole transport layer and may further have an electron blocking layer on the hole transport layer. Layer 790b may have an electron transport layer and an electron injection layer on the electron transport layer, and may further have a hole blocking layer between the light-emitting layer 772 and the electron transport layer. When the lower electrode 761 is the cathode and the upper electrode 762 is the anode, for example, layer 780a may have an electron injection layer and an electron transport layer on the electron injection layer, and may further have a hole blocking layer on the electron transport layer. Furthermore, layer 790a may have a hole transport layer and an electron blocking layer between the light-emitting layer 771 and the hole transport layer. Also, layer 780b may have an electron transport layer and an electron blocking layer on the electron transport layer. Also, layer 790b may have a hole transport layer and a hole injection layer on the hole transport layer and an electron blocking layer between the light-emitting layer 772 and the hole transport layer.

[0452] Furthermore, when fabricating a tandem light-emitting device, the two light-emitting units are stacked with a charge generation layer 785 in between. The charge generation layer 785 has the function of injecting electrons into one of the two light-emitting units and holes into the other when a voltage is applied between the pair of electrodes.

[0453] Furthermore, an example of a tandem-structured light-emitting device is the configuration shown in Figures 25A to 25C.

[0454] Figure 25A shows a configuration having three light-emitting units. In Figure 25A, multiple light-emitting units (light-emitting units 763a, 763b, and 763c) are connected in series via a charge generation layer 785. Light-emitting unit 763a has layer 780a, light-emitting layer 771, and layer 790a; light-emitting unit 763b has layer 780b, light-emitting layer 772, and layer 790b; and light-emitting unit 763c has layer 780c, light-emitting layer 773, and layer 790c. Layer 780c can use a configuration applicable to layers 780a and 780b, and layer 790c can use a configuration applicable to layers 790a and 790b.

[0455] In Figure 25A, the light-emitting layers 771, 772, and 773 can each have a light-emitting material that emits light of the same color. Specifically, the light-emitting layers 771, 772, and 773 can all be configured to have a blue (B) light-emitting material.

[0456] Furthermore, in Figure 25A, some or all of the light-emitting layers 771, 772, and 773 may be made of light-emitting materials with different emission colors. For example, a combination of emission colors for the light-emitting layers 771, 772, and 773 could be two of which are blue (B) and the remaining one is green (G).

[0457] Figure 25B shows a configuration having four light-emitting units. In Figure 25B, multiple light-emitting units (light-emitting units 763a, 763b, 763c, and 763d) are connected in series via a charge generation layer 785. Light-emitting unit 763a has layer 780a, light-emitting layer 771, and layer 790a; light-emitting unit 763b has layer 780b, light-emitting layer 772, and layer 790b; light-emitting unit 763c has layer 780c, light-emitting layer 773, and layer 790c; and light-emitting unit 763d has layer 780d, light-emitting layer 774, and layer 790d. Note that layer 780c can use a configuration applicable to layers 780a and 780b, and layer 790c can use a configuration applicable to layers 790a and 790b.

[0458] In Figure 25B, the light-emitting layers 771, 772, 773, and 774 can each have a light-emitting material that emits light of the same color. Specifically, the light-emitting layers 771, 772, 773, and 774 can all be configured to have a blue (B) light-emitting material.

[0459] Furthermore, in Figure 25B, some or all of the light-emitting layers 771, 772, 773, and 774 may be made of light-emitting materials with different emission colors. For example, a combination of emission colors for light-emitting layers 771, 772, and 773 could be one or more blue (B) and the rest green (G).

[0460] Figure 25C shows an example in which layers 765 and 764 are superimposed on the light-emitting device shown in Figure 25A. In the configuration shown in Figure 25B, layers 765 and 764 can also be superimposed on the light-emitting device.

[0461] Next, we will describe materials that can be used in light-emitting devices.

[0462] Of the lower electrode 761 and the 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.

[0463] Furthermore, a conductive film that transmits visible light may also be used on the electrode that does not extract light. In this case, it is preferable to place the electrode between the reflective layer and the EL layer 763. In other words, the light emitted from the EL layer 763 may be reflected by the reflective layer and extracted from the display device.

[0464] As the material for forming the pair of electrodes of the light-emitting device, metals, alloys, electrically conductive compounds, and mixtures thereof can be used as appropriate. Specifically, such materials include metals such as aluminum, magnesium, titanium, chromium, manganese, iron, cobalt, nickel, copper, gallium, zinc, indium, tin, molybdenum, tantalum, tungsten, palladium, gold, platinum, silver, yttrium, and neodymium, and alloys containing these in appropriate combinations. Other examples of such materials include indium tin oxide (In-Sn oxide, also called ITO), In-Si-Sn oxide (also called ITSO), indium zinc oxide (In-Zn oxide), and In-W-Zn oxide. Furthermore, such materials include aluminum-containing alloys such as aluminum, nickel, and lanthanum alloys (Al-Ni-La), and silver-containing alloys such as silver-magnesium alloys and silver-palladium-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.

[0465] 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.

[0466] Furthermore, the semi-transparent / semi-reflective electrode can have a laminated structure consisting of a conductive layer that can be used as a reflective electrode and a conductive layer that can be used as an electrode that transmits visible light (also called a transparent electrode).

[0467] The light transmittance of the transparent electrode shall be 40% or more. For example, it is preferable to use an electrode for the transparent electrode of a light-emitting device that has a transmittance of 40% or more for visible light (light with a wavelength of 360 nm to 830 nm, for example, light with a wavelength of 400 nm to less than 750 nm). The visible light reflectance of the semi-transparent and semi-reflective electrodes shall be 10% to 95%, preferably 30% to 80%. The visible light reflectance of the reflective electrode shall be 40% to 100%, preferably 70% to 100%. The resistivity of these electrodes shall be 1 × 10⁻⁶ −２ A value of Ωcm or less is preferable.

[0468] A light-emitting device has at least a light-emitting layer. Furthermore, the light-emitting device may have layers other than the light-emitting layer, including materials with high hole injection properties, materials with high hole transport properties, hole-blocking materials, materials with high electron transport properties, electron-blocking materials, materials with high electron injection properties, or bipolar materials (materials with high electron and hole transport properties). For example, a light-emitting device 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. Also, if the light-emitting device has a tandem structure with multiple light-emitting layers, a charge generation layer may be included as an intermediate layer between one light-emitting layer and another.

[0469] 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.

[0470] 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.

[0471] Examples of luminescent materials include fluorescent materials, phosphorescent materials, TADF materials, and quantum dot materials.

[0472] 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.

[0473] 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.

[0474] The light-emitting layer may contain one or more types of organic compounds (host material, assist material, etc.) in addition to the light-emitting substance (guest material). One or more types of organic compounds may include materials with high hole transport properties (hole transport materials) and / or materials with high electron transport properties (electron transport materials). As the hole transport material, one of the materials with high hole transport properties that can be used in the hole transport layer, as described later, may be used. As the electron transport material, one of the materials with high electron transport properties that can be used in the electron transport layer, as described later, may be used. Furthermore, one or more types of organic compounds may include bipolar materials or TADF materials.

[0475] 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.

[0476] 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).

[0477] As the hole-transporting material, a material with high hole-transporting properties that can be used in the hole-transporting layer, as described later, can be used.

[0478] 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, hexaazatriphenylene derivatives, and radialene derivatives can also be used.

[0479] 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.

[0480] The hole transport layer is a layer that transports holes injected from the anode by the hole injection layer to the light-emitting layer. The hole transport layer is a layer containing a hole-transporting material. The hole-transporting material is 1 × 10⁻¹⁶ −６ cm ２ Materials having a hole mobility of 1 / Vs or higher are preferred. Other materials can also be used as long as they have higher hole transport capabilities than electron transport. Preferred hole transport materials include π-electron-rich heteroaromatic compounds (e.g., carbazole derivatives, thiophene derivatives, furan derivatives, etc.) and aromatic amines (compounds having an aromatic amine skeleton), which are materials with high hole transport capabilities.

[0481] 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. For example, if the LUMO level of the hole-transporting layer is 0.3 eV or more higher than the LUMO level of the material constituting the light-emitting layer (at least the host material), it functions as an electron blocking layer. Furthermore, if the LUMO level of the hole-transporting layer is 0.5 eV or more higher than the LUMO level of the material constituting the light-emitting layer (at least the host material), it is preferable from the viewpoint of increasing luminescence efficiency.

[0482] 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.

[0483] 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 1 / Vs or higher are preferred. However, other materials can also be used as long as they have higher electron transport capabilities than holes. Examples of electron-transporting materials include metal complexes having a quinoline skeleton, metal complexes having a benzoquinoline skeleton, metal complexes having an oxazole skeleton, metal complexes having a thiazole skeleton, as well as oxadiazole derivatives, triazole derivatives, imidazole derivatives, oxazole derivatives, thiazole derivatives, phenanthroline derivatives, quinoline derivatives having a quinoline ligand, benzoquinoline derivatives, quinoxaline derivatives, dibenzoquinoxaline derivatives, pyridine derivatives, bipyridine derivatives, pyrimidine derivatives, triazine derivatives, and other π-electron-deficient heteroaromatic compounds containing nitrogen-containing heteroaromatic compounds, which are materials with high electron transport capabilities.

[0484] The hole-blocking layer is provided in contact with the light-emitting layer. The hole-blocking layer is a layer containing a material that has electron-transporting properties and is capable of blocking holes. Among the electron-transporting materials mentioned above, a material with hole-blocking properties can be used for the hole-blocking layer. When the electron-transporting layer in contact with the light-emitting layer functions as a hole-blocking layer, it is preferable to use a material whose HOMO level is 0.5 eV or more lower than the HOMO level of the material contained in the light-emitting layer.

[0485] Because hole-blocking layers possess electron-transporting properties, they can also be called electron-transporting layers. Furthermore, among electron-transporting layers, those possessing hole-blocking properties can also be referred to as hole-blocking layers. For example, electron-transporting materials can be found in the materials described under "Electron-Transporting Layers."

[0486] The electron injection layer is a layer that injects electrons from the cathode to the electron transport layer, and is a layer containing a material with high electron injection potential. Alkali metals, alkaline earth metals, or compounds thereof can be used as materials with high electron injection potential. Composite materials containing both electron transport materials and donor materials (electron-donating materials) can also be used as materials with high electron injection potential.

[0487] Furthermore, it is preferable that the LUMO level of a material with high electron injection capacity has a small difference (specifically, 0.5 eV or less) from the work function value of the material used as the cathode.

[0488] The electron injection layer contains, for example, lithium, cesium, ytterbium, lithium fluoride (LiF), cesium fluoride (CsF), and calcium fluoride (CaF). ｘ (where X is any number), 8-(quinolinolato)lithium (abbreviation: Liq), 2-(2-pyridyl)phenolatritium (abbreviation: LiPP), 2-(2-pyridyl)-3-pyridinolatritium (abbreviation: LiPPy), 4-phenyl-2-(2-pyridyl)phenolatritium (abbreviation: LiPPP), lithium oxide (LiO ｘAlkali metals such as cesium carbonate, alkaline earth metals, or compounds thereof can be used. The electron injection layer may also be a multilayer structure of two or more layers. For example, a multilayer structure in which lithium fluoride is used as the first layer and ytterbium is provided as the second layer can be used.

[0489] 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.

[0490] Furthermore, the Lowest Unoccupied Molecular Orbital (LUMO) level of organic compounds with lone pairs of electrons is preferably between -3.6 eV and -2.3 eV. In general, the Highest Occupied Molecular Orbital (HOMO) level and the LUMO level of organic compounds can be estimated by methods such as cyclic voltammetry (CV), photoelectron spectroscopy, optical absorption spectroscopy, and inverse photoelectron spectroscopy.

[0491] For example, 4,7-diphenyl-1,10-phenanthroline (abbreviated as BPhen), 2,9-di(naphthalene-2-yl)-4,7-diphenyl-1,10-phenanthroline (abbreviated as NBPhen), 2,2'-(1,3-phenylene)bis(9-phenyl-1,10-phenanthroline) (abbreviated as mPPhen2P), diquinoxalino[2,3-a:2',3'-c]phenazine (abbreviated as HATNA), 2,4,6-tris[3'-(pyridine-3-yl)biphenyl-3-yl]-1,3,5-triazine (abbreviated as TmPPPyTz), etc., can be used in organic compounds containing lone pairs of electrons. Compared to BPhen, NBPhen has a higher glass transition temperature (Tg) and superior heat resistance.

[0492] The charge generation layer may be a configuration in which electron acceptors are added to a hole-transporting material (also called a charge generation region), or a configuration in which electron donors are added to an electron-transporting material (also called an electron injection buffer layer). Furthermore, both of these configurations may be laminated. Additionally, an electron relay layer may be provided between the charge generation region and the electron injection buffer layer. By forming an intermediate layer using the materials described above, the increase in driving voltage when an organic compound layer including a light-emitting layer is laminated can be suppressed.

[0493] The charge generation layer preferably has a P-type layer. The P-type layer preferably contains an acceptor material, for example, a hole transport material and an acceptor material that can be applied to the hole injection layer described above. Examples include oxides of metals belonging to groups 4 to 8 of the periodic table. Specifically, examples include vanadium oxide, niobium oxide, tantalum oxide, chromium oxide, molybdenum oxide, tungsten oxide, manganese oxide, and rhenium oxide. The acceptor material described above may also be used. Alternatively, the P-type layer may be used as a mixed film formed by mixing the materials, or as single films containing each material stacked together.

[0494] Furthermore, the charge generation layer preferably includes a layer containing a material with high electron injection properties. This layer can also be called an electron injection buffer layer or an N-type layer. The electron injection buffer layer is preferably provided between the P-type layer and the electron transport layer. By providing an electron injection buffer layer, the injection barrier between the P-type layer and the electron transport layer can be relaxed, allowing electrons generated in the P-type layer to be easily injected into the electron transport layer.

[0495] The electron injection buffer layer preferably contains an organic compound with a phenanthroline skeleton. The organic compound containing the phenanthroline skeleton has an electron mobility of 1 × 10⁻¹⁶ at an electric field strength [V / cm] square root of 600. −７ cm ２ / Vs or more, preferably 1 x 10 −６ cm ２It is preferable that the electron mobility is ≥ / Vs. However, other materials can be used as long as they have higher electron transport properties than holes.

[0496] The organic compound containing the phenanthroline skeleton is preferably a compound containing both the phenanthroline skeleton and an aromatic ring. The aromatic ring can be a monocyclic or polycyclic aromatic ring.

[0497] Furthermore, the electron injection buffer layer preferably contains a metal or a metal compound in addition to the organic compound containing the phenanthroline skeleton. The metal in the metal compound preferably includes alkali metals, alkaline earth metals, rare earth metals, or metals belonging to Group 11 or Group 13 of the periodic table, and their oxides and carbonates. For example, it can be configured to include an alkali metal compound or an alkaline earth metal compound. Specifically, the electron injection buffer layer preferably has an inorganic compound containing an alkali metal and oxygen, or an inorganic compound containing an alkaline earth metal and oxygen, and an inorganic compound containing lithium and oxygen (lithium oxide (Li ２ It is more preferable to have O, etc. Also, the electron injection buffer layer may contain cesium (Cs), magnesium (Mg), calcium (Ca), ytterbium (Yb), indium (In), lithium oxide (Li ２ 0), cesium carbonate, etc., can be suitably used. Organic compounds such as tetrathianaphthalene may also be used. In addition, materials applicable to the electron injection buffer layer can be suitably used.

[0498] Furthermore, the electron injection buffer layer may have a laminated structure consisting of a layer containing an organic compound and a layer containing a metal or metal compound located on the cathode side of the layer containing the organic compound. Alternatively, it may be a mixed layer of an organic compound and a metal or metal compound. When the charge generation region is a mixed layer, it is preferable because it requires fewer deposition chambers, thus reducing manufacturing costs, and also contributes to improving the stability of the light-emitting device.

[0499] Furthermore, in addition to the organic compounds described above, organic compounds containing a phenanthroline skeleton that have electron-donating substituents can also be used. The phenanthroline skeleton is a skeleton that readily interacts with metals and other materials, and by further possessing electron-donating groups in such organic compounds containing a phenanthroline skeleton, the electron density of the phenanthroline skeleton increases, making it even easier to interact with metals or metal compounds. In particular, when metals from Group 3, Group 11, Group 12, or Group 13 are used as the metal in the metal or metal compound, it is possible to suppress the increase in driving voltage and provide a tandem type light-emitting device with good characteristics.

[0500] Specific examples of electron-donating groups include alkyl groups, alkoxy groups, aryloxy groups, alkylamino groups, arylamino groups, and heterocyclic amino groups. However, the electron-donating groups that are preferable to introduce into the phenanthroline ring are not limited to these. Any group that can increase the electron density of the phenanthroline ring when introduced into it can be used as an electron-donating group. Furthermore, the electron-donating group may be introduced into the phenanthroline ring via an arylene group such as a phenylene group, and the p-phenylene group is preferred as the arylene group.

[0501] The electron injection buffer layer may further contain an organic compound different from the organic compound containing the phenanthroline skeleton. Preferably, the organic compound is an organic compound with electron transport properties. In particular, it is preferable that the organic compound has two or more heteroaromatic rings bonded or condensed to each other, and that these two or more heteroaromatic rings have a total of three or more heteroatoms. By including such an organic compound in the first layer, improvements in heat resistance and electron transport properties can be achieved.

[0502] 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 P-type layer 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 P-type layer and the electron transport layer. The electron relay layer has the function of preventing interaction between the P-type layer and the electron injection buffer layer (or electron transport layer) and smoothly transferring electrons.

[0503] 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.

[0504] Furthermore, the P-type layer, electron injection buffer layer, and electron relay layer described above may not be clearly distinguishable depending on their cross-sectional shape or characteristics.

[0505] 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.

[0506] This embodiment can be implemented in appropriate combination with other embodiments described herein, at least in part.

[0507] (Embodiment 6) In this embodiment, an electronic device according to one aspect of the present invention will be described with reference to Figures 26 to 28.

[0508] The electronic device of this embodiment has a display panel (display device) according to one aspect of the present invention in its display unit. The display panel according to one aspect of the present invention is easily made high-definition and high-resolution, and can achieve high display quality. Therefore, it can be used in the display units of various electronic devices.

[0509] 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.

[0510] In particular, a display panel according to one embodiment of the present invention can be used suitably in electronic devices having a relatively small display area because it can increase the resolution. Examples of such electronic devices include wristwatch-type and bracelet-type information terminals (wearable devices), as well as wearable devices that can be worn on the head, such as VR devices such as head-mounted displays, AR devices such as glasses, and MR devices.

[0511] A display panel according to one embodiment of the present invention preferably has an extremely high resolution such as HD (1280 x 720 pixels), FHD (1920 x 1080 pixels), WQHD (2560 x 1440 pixels), WQXGA (2560 x 1600 pixels), 4K (3840 x 2160 pixels), or 8K (7680 x 4320 pixels). In particular, a resolution of 4K, 8K, or higher is preferred. Furthermore, the pixel density (resolution) of the display panel according to one embodiment of the present invention is preferably 100 ppi or more, preferably 300 ppi or more, more preferably 500 ppi or more, more preferably 1000 ppi or more, more preferably 2000 ppi or more, more preferably 3000 ppi or more, more preferably 5000 ppi or more, and even more preferably 7000 ppi or more. By using a display panel having either high resolution or high detail, or both, it becomes possible to further enhance the sense of presence and depth. Furthermore, there are no particular limitations on the aspect ratio of the display panel in one embodiment of the present invention. For example, the display panel can support various aspect ratios such as 1:1 (square), 4:3, 16:9, and 16:10.

[0512] The electronic device of this embodiment may have sensors (including those with the function of detecting, detecting, or measuring force, displacement, position, velocity, acceleration, angular velocity, rotational speed, distance, light, liquid, magnetism, temperature, chemical substances, sound, time, hardness, electric field, current, voltage, power, radiation, flow rate, humidity, gradient, vibration, odor, or infrared radiation).

[0513] 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.

[0514] Figures 26A to 26D illustrate an example of a wearable device that can be worn on the head. These wearable devices have one or both functions: the ability to display AR content and / or VR content. In addition to AR and VR, these wearable devices may also have functions to display SR or MR content. By having an electronic device that has the ability 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.

[0515] The electronic device 700A shown in Figure 26A and the electronic device 700B shown in Figure 26B 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.

[0516] A display panel according to one embodiment of the present invention can be applied to the display panel 751. Therefore, an electronic device capable of displaying extremely high resolution can be created.

[0517] 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.

[0518] 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.

[0519] 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.

[0520] Furthermore, electronic devices 700A and 700B are equipped with batteries that can be charged wirelessly, wired, or both.

[0521] 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.

[0522] Various types of touch sensors can be applied to the touch sensor module. For example, various methods such as capacitive, resistive, infrared, electromagnetic induction, surface acoustic wave, and optical sensors can be used. In particular, it is preferable to apply a capacitive or optical sensor to the touch sensor module.

[0523] When using an optical touch sensor, a photoelectric conversion device (also called a photoelectric element) can be used as the light-receiving device (also called a photoelectric element). The active layer of the photoelectric conversion device can be made of either an inorganic semiconductor or an organic semiconductor, or both.

[0524] The electronic device 800A shown in Figure 26C and the electronic device 800B shown in Figure 26D 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.

[0525] A display panel according to one embodiment of the present invention can be applied to the display unit 820. Therefore, an electronic device capable of displaying extremely high resolution can be created. This allows the user to experience a high level of immersion.

[0526] The display unit 820 is located inside the housing 821 in a position visible through the lens 832. Furthermore, by displaying different images on a pair of display units 820, a three-dimensional display using parallax can be achieved.

[0527] Electronic devices 800A and 800B can each be described as electronic devices for VR. A user wearing electronic device 800A or electronic device 800B can view the image displayed on the display unit 820 through the lens 832.

[0528] 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.

[0529] 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 26C and other figures as resembling the temples (or arms) of eyeglasses, it is not limited to this. The attachment portion 823 only needs to be wearable by the user; for example, it may be helmet-shaped or band-shaped.

[0530] 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.

[0531] Although an example with an imaging unit 825 is shown here, any distance measuring sensor (hereinafter also referred to as a detection unit) capable of measuring the distance to an object can be provided. In other words, the imaging unit 825 is one form of the detection unit. As the detection unit, for example, an image sensor or a distance image sensor such as LiDAR (Light Detection and Ranging) can be used. By using the image obtained by the camera and the image obtained by the distance image sensor, more information can be acquired, enabling more accurate gesture control.

[0532] 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.

[0533] Electronic devices 800A and 800B may each have input terminals. Cables can be connected to the input terminals to supply video signals from video output devices, etc., and power for charging batteries provided in the electronic devices.

[0534] 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 26A 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 26C has a function for transmitting information to the earphone 750 through its wireless communication function.

[0535] Furthermore, the electronic device may have an earphone section. The electronic device 700B shown in Figure 26B has an earphone section 727. For example, the earphone section 727 and the control unit can be connected to each other by wire. Part of the wiring connecting the earphone section 727 and the control unit may be located inside the housing 721 or the mounting section 723.

[0536] Similarly, the electronic device 800B shown in Figure 26D has an earphone unit 827. For example, the earphone unit 827 and the control unit 824 can be connected to each other by wire. Part of the wiring connecting the earphone unit 827 and the control unit 824 may be located inside the housing 821 or the mounting unit 823. Also, the earphone unit 827 and the mounting unit 823 may have magnets. This allows the earphone unit 827 to be fixed to the mounting unit 823 by magnetic force, which is preferable as it facilitates storage.

[0537] 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.

[0538] Thus, as one embodiment of the present invention, both eyeglass-type (electronic devices 700A and 700B, etc.) and goggle-type (electronic devices 800A and 800B, etc.) are preferred as electronic devices.

[0539] The electronic device 6500 shown in Figure 27A is a portable information terminal that can be used as a smartphone.

[0540] 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.

[0541] A display panel according to one embodiment of the present invention can be applied to the display unit 6502.

[0542] Figure 27B is a schematic cross-sectional view of the housing 6501 including the end on the microphone 6506 side.

[0543] 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.

[0544] 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).

[0545] 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.

[0546] A display device according to one embodiment of the present invention can be applied to the display panel 6511. As a result, an extremely lightweight electronic device can be realized. Furthermore, because the display panel 6511 is extremely thin, a large-capacity battery 6518 can be installed while keeping the thickness of the electronic device low. In addition, by folding back a part of the display panel 6511 and placing the connection part with the FPC 6515 on the back of the pixel section, an electronic device with a narrow bezel can be realized.

[0547] Figure 27C 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 to be supported by a stand 7103.

[0548] The television device 7100 shown in Figure 27C 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.

[0549] 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.

[0550] Figure 27D 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.

[0551] Figures 27E and 27F show examples of digital signage.

[0552] The digital signage 7300 shown in Figure 27E 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.

[0553] Figure 27F 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.

[0554] 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.

[0555] 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.

[0556] Furthermore, as shown in Figures 27E and 27F, it is preferable that the digital signage 7300 or digital signage 7400 can be linked wirelessly with an information terminal 7311 or information terminal 7411 such as a smartphone owned by the user. For example, the advertising information displayed on the display unit 7000 can be displayed on the screen of the information terminal 7311 or information terminal 7411. Also, the display on the display unit 7000 can be switched by operating the information terminal 7311 or information terminal 7411.

[0557] Furthermore, the digital signage 7300 or digital signage 7400 can be used to run games using the screen of the information terminal 7311 or information terminal 7411 as the control device (controller). This allows an unspecified number of users to participate in and enjoy the game simultaneously.

[0558] In Figures 27C to 27F, a display panel according to one embodiment of the present invention can be applied to the display unit 7000.

[0559] The electronic device shown in Figures 28A to 28G includes a housing 9000, a display unit 9001, a speaker 9003, operation keys 9005 (including a power switch or operation switch), connection terminals 9006, a sensor 9007 (including a function to detect, identify, or measure force, displacement, position, velocity, acceleration, angular velocity, rotational speed, distance, light, liquid, magnetism, temperature, chemical substances, sound, time, hardness, electric field, current, voltage, power, radiation, flow rate, humidity, gradient, vibration, odor, or infrared radiation), a microphone 9008, and the like.

[0560] The electronic devices shown in Figures 28A to 28G 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.

[0561] Details of the electronic equipment shown in Figures 28A to 28G will be explained below.

[0562] Figure 28A is a perspective view showing a personal digital information terminal (PDI) 9101. The PDI 9101 can be used, for example, as a smartphone. The PDI 9101 may also be equipped with a speaker 9003, connection terminals 9006, sensors 9007, etc. Furthermore, the PDI 9101 can display text and image information on multiple surfaces. Figure 28A 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, and phone calls, the subject of an email or SNS message, the sender's name, date and time, battery level, and signal strength. Alternatively, icons 9050 or the like may be displayed in the location where the information 9051 is displayed.

[0563] Figure 28B is a perspective view showing a 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.

[0564] Figure 28C 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.

[0565] Figure 28D 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. The charging operation may be performed by wireless power supply.

[0566] Figures 28E to 28G are perspective views showing a foldable portable information terminal 9201. Figure 28E shows the portable information terminal 9201 in an unfolded state, Figure 28G shows it in a folded state, and Figure 28F shows a perspective view of the state in between, transitioning from one of Figures 28E or 28G to the other. The portable 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 portable information terminal 9201 is supported by three housings 9000 connected by hinges 9055. For example, the display unit 9001 can be bent with a radius of curvature of 0.1 mm to 150 mm.

[0567] Figures 29A and 29B show the external appearance of the head-mounted display 8300. The head-mounted display 8300 includes a housing 8301, a display unit 8302, a band-shaped fixing device 8304, and a pair of lenses 8305.

[0568] The user can view the display on the display unit 8302 through the lens 8305. It is preferable to arrange the display unit 8302 in a curved shape, as this allows the user to experience a greater sense of presence. Furthermore, by viewing different images displayed in different areas of the display unit 8302 through the lens 8305, three-dimensional display using parallax can be performed. Note that the configuration is not limited to having one display unit 8302; two display units 8302 may be provided, with one display unit for each of the user's eyes.

[0569] A display device according to one embodiment of the present invention can be applied to the display unit 8302. The display device according to one embodiment of the present invention can also achieve extremely high resolution. Therefore, even when the display is magnified and viewed using the lens 8305, the pixels are difficult for the user to see. In other words, the display unit 8302 can be used to allow the user to view a highly realistic image.

[0570] Furthermore, it is preferable that the head-mounted display 8300 has head tracking and eye tracking functions. This allows the displayed image to move in accordance with the user's movements and the direction of the user's gaze. This makes it possible to present the user with highly immersive images. For example, as shown in Figure 29C, a passenger in the back seat of a car can wear the head-mounted display 8300. In this case, because the image moves in sync with the shaking of the car body and the gaze is not fixed, motion sickness can be reduced compared to viewing images on a smartphone or tablet device, for example.

[0571] This embodiment can be implemented in appropriate combination with other embodiments described herein, at least in part.

[0572] DTS: Distance, EL11: Deposition chamber, EL12: Deposition chamber, EL13: Deposition chamber, EL14: Deposition chamber, EL15: Deposition chamber, EL16: Deposition chamber, HT: Processing chamber, LL: Loading chamber, PL: Transient, PP: Processing chamber, RBT Transport robot, SP: deposition chamber, Sx: gap, Sy: gap, TF: transport chamber, UL: discharge chamber, 100: display device, 101: substrate, 110: light-emitting element, 110B: pixel, 110G: pixel, 110R: pixel, 111: pixel electrode, 111B: pixel electrode, 111G: pixel electrode, 111R: pixel electrode, 112: EL layer, 112a: EL layer, 113: upper electrode, 115: upper electrode, 120: partition wall, 120_1: first part, 120_2: second part, 120f: conductive film, 121: deposition material, 122: deposition material, 123: Film material, 125: Rotating shaft, 127a: Unit, 127b: Unit, 127c: Unit, 128: Nozzle, 131: Insulating layer, 132: Insulating layer, 133: Insulating layer, 134: Layer, 134f: Layer, 135: Protective layer, 136: Layer, 137: Layer, 137b: Layer, 137c: Layer, 138: Insulating layer, 141: Resist mask, 150: Transistor, 151: Semiconductor layer, 152: Insulating layer, 153: Conductive layer, 154: Conductive layer, 155: Conductive layer, 155a: Conductive layer, 155b: Conductive layer, 156: Conductive layer, 161B: Color Filter, 161G: Color filter, 161R: Color filter, 162B: Wavelength conversion layer, 162G: Wavelength conversion layer, 162R: Wavelength conversion layer, 163: Separation layer, 164: Substrate, 201: Transistor, 202: Transistor, 204: Connection part, 205: Transistor, 209: Transistor, 210: Transistor, 211: Insulating layer, 212: 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, 228: region, 231: semiconductor layer, 231i: channel formation region, 231n: low resistance region, 240: capacitance, 241: conductive layer, 242: connection layer, 243: insulating layer, 245: conductive layer, 251: conductive layer, 252: conductive layer, 254: insulating layer, 255: insulating layer, 256: plug, 261: insulating layer, 262: insulating layer, 263: insulating layer, 264: insulating layer, 265: insulating layer, 271: plug, 274: plug, 274a: conductive layer, 274b: conductive layer, 280: display module, 281: display section, 282: circuit section,283: Pixel circuit section, 283a: Pixel circuit, 284: Pixel section, 284a: Pixel, 285: Terminal section, 286: Wiring section, 290: FPC, 291: Substrate, 292: Substrate, 301: Substrate, 310: Transistor, 311: Conductive layer, 312: Low-resistance region, 313: Insulating layer, 314: Insulating layer, 315: Element isolation layer, 320: Transistor, 321: Semiconductor layer, 323: Insulating layer, 324: Conductive layer, 325: Conductive layer, 326: Insulating layer, 327: Conductive layer, 328: Insulating layer, 329: Insulating layer, 331: Substrate, 332: Insulating layer, 400A: Display device, 400B: Display device, 400 C: Display device, 400D: Display device, 400E: Display device, 401: Substrate, 411a: Pixel electrode, 411b: Pixel electrode, 411c: Pixel electrode, 412: Layer, 413: Separation layer, 414G: Wavelength conversion layer, 414R: Wavelength conversion layer, 415G: Color filter, 415R: Color filter, 416: Protective layer, 417: Light-shielding layer, 419: Resin layer, 420: Partition, 421: Insulating layer, 426a: Optical adjustment layer, 426b: Optical adjustment layer, 426c: Optical adjustment layer, 430: Light-emitting element, 430a: Pixel, 430b: Pixel, 430c: Pixel, 442: Adhesive layer, 443: Space, 451: Substrate, 452: Substrate, 453: Substrate, 454: Substrate, 455: Adhesive layer, 462: Display unit, 464: Circuit, 465: Wiring, 466: Conductive layer, 472: FPC, 473: IC, 700A: Electronic equipment, 700B: Electronic equipment, 721: Housing, 723: Mounting unit, 727: Earphone unit, 750: Earphone, 751: Display panel, 753: Optical component, 756: Display area, 757: Frame, 758: Nose pad, 761: Lower electrode, 762: Upper electrode, 763: EL layer, 763a: Light-emitting unit, 763b: Light-emitting unit, 763c: Light-emitting unit, 763d: Light-emitting unit , 764: layer, 765: layer, 771: light-emitting layer, 772: light-emitting layer, 773: light-emitting layer, 774: light-emitting layer, 780: layer, 780a: layer, 780b: layer, 780c: layer, 780d: layer, 781: layer, 782: layer, 785: charge generation layer, 790: layer, 790a: layer, 790b: layer, 790c: layer, 790d: 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: Enclosure, 7103: Stand, 7111: Remote control unit, 7200: Notebook personal computer, 7211: Enclosure, 7212: Keyboard, 7213: Pointing device, 7214: External connection port, 7300: Digital signage, 7301: Enclosure, 7303: Speaker, 7311: Information terminal, 7400: Digital signage, 7401: Pillar, 7411: Information terminal, 8300: Head-mounted display, 8301: Housing, 8302: Display unit, 8304: Fixture, 8305: Lens, 9000: Housing, 9001: Display unit, 9002: Camera, 9003: Speaker, 9005: Operation key, 9006: Connection terminal, 9007: Sensor, 9008: Microphone, 9050: Icon, 9051: Information, 9052: Information, 9053: Information, 9054: Information, 9055: Hinge, 9101: Portable information terminal, 9102: Portable information terminal, 9103: Tablet terminal, 9200: Portable information terminal, 9201: Portable information terminal,

Claims

It comprises a substrate, pixel electrodes, an EL layer, an upper electrode, a partition wall, a wavelength conversion layer, and a color filter. The partition wall has a first portion and a second portion, which are provided spaced apart on the substrate. The pixel electrode is located on the substrate, The pixel electrode is located between the first portion and the second portion in a plan view. The EL layer is in contact with the upper surface of the pixel electrode, The upper electrode is in contact with the upper surface of the EL layer and also in contact with a part of the side surface of the partition wall. The wavelength conversion layer is located above the upper electrode, The color filter is located above the wavelength conversion layer, The partition wall has an inverse tapered shape in cross-section and is conductive. Display device. 　 In claim 1, The EL layer has the function of emitting blue light, The wavelength conversion layer has quantum dots or fluorescent material. Display device. 　 In claim 1, The EL layer has the function of emitting blue light and green light. The wavelength conversion layer has quantum dots or fluorescent material. Display device. 　 In claim 1, The substrate has a first insulating layer, The first insulating layer has an end on the pixel electrode, The partition wall is located on the first insulating layer, The angle between the contact surface of the partition wall and the first insulating layer and the side surface is 95 degrees or more and 150 degrees or less. Display device. 　 In claim 2, The EL layer comprises a first layer, a second layer, and a charge generation layer between the first layer and the second layer. The first layer comprises a first luminescent compound, The second layer comprises the first luminescent compound, The charge generation layer comprises one selected from metals and metal compounds, a first organic compound, and a second organic compound different from the first organic compound. The first organic compound comprises a phenanthroline skeleton, and the device is a display device. 　 In claim 3, The EL layer comprises a first layer, a second layer, and a charge generation layer between the first layer and the second layer. The first layer comprises a first luminescent compound, The second layer comprises a second luminescent compound, The charge generation layer comprises one selected from metals and metal compounds, a first organic compound, and a second organic compound different from the first organic compound. The first organic compound comprises a phenanthroline skeleton, and the device is a display device. 　 In claim 5 or claim 6, A display device wherein the metal comprises one or more selected from cesium, magnesium, calcium, ytterbium, and indium. In claim 5 or claim 6, The aforementioned metal compound comprises one or more selected from lithium oxide and cesium carbonate, wherein the device is a metal-containing compound. 　 In claim 5 or claim 6, The second organic compound is an organic compound having electron transport properties, in a display device. 　 In claim 1, Having a transistor on the aforementioned substrate, The transistor is located below the pixel electrode, The transistor includes a metal oxide in the semiconductor layer in which the channel is formed. Display device. 　 In claim 10, The aforementioned metal oxide is indium oxide. Display device. 　 It comprises a substrate, a first pixel electrode, a second pixel electrode, a first EL layer, a second EL layer, a first upper electrode, a second upper electrode, a partition wall, a first wavelength conversion layer, and a second wavelength conversion layer. The first pixel electrode and the second pixel electrode are provided on the substrate at a distance from each other. The partition wall is located on the substrate, The partition wall is located between the first pixel electrode and the second pixel electrode in a plan view. The first EL layer contains a first light-emitting compound and is in contact with the upper surface of the first pixel electrode. The second EL layer contains the first luminescent compound and is in contact with the upper surface of the second pixel electrode. The first upper electrode covers the upper surface and edges of the first EL layer and is in contact with a part of the first side surface of the partition wall. The second upper electrode covers the upper surface and edges of the second EL layer and is in contact with a part of the second side surface of the partition wall. The first wavelength conversion layer is located above the first upper electrode, The second wavelength conversion layer is located above the second upper electrode, The first wavelength conversion layer and the second wavelength conversion layer are provided at a distance from each other. The partition wall has an inverse tapered shape in cross-section and is conductive. Display device. 　 In claim 12, The first EL layer and the second EL layer each have the function of emitting blue light. The first wavelength conversion layer has the function of converting the blue light into red light. The second wavelength conversion layer has the function of converting the blue light into green light. Display device. 　 In claim 12, Having a separation layer, The separation layer is located between the first wavelength conversion layer and the second wavelength conversion layer, and is in contact with each of the first wavelength conversion layer and the second wavelength conversion layer. Display device. 　 It comprises a substrate, a first pixel on the substrate, a second pixel, and a partition wall. The first pixel comprises a first pixel electrode, a first EL layer in contact with the upper surface of the first pixel electrode, a first upper electrode, and a wavelength conversion layer located above the first upper electrode. The second pixel comprises a second pixel electrode, a second EL layer in contact with the upper surface of the second pixel electrode, and a second upper electrode. The first EL layer and the second EL layer each have the function of emitting blue light. The wavelength conversion layer has the function of converting the blue light into light of a different color from blue, The first pixel has the function of emitting light of a different color from the blue light, The second pixel has the function of emitting blue light, The first pixel electrode and the second pixel electrode are provided on the substrate at a distance from each other. The partition wall is located on the substrate, The partition wall is located between the first pixel electrode and the second pixel electrode in a plan view. The first upper electrode covers the upper surface and edges of the first EL layer and is in contact with a part of the first side surface of the partition wall. The second upper electrode covers the upper surface and edges of the second EL layer and is in contact with a part of the second side surface of the partition wall. The partition wall has an inverse tapered shape in cross-section and is conductive. Display device.

Images