Display device and method for producing display device

Abstract

Provided is a display device that facilitates achievement of a high definition. Provided is a display device having a high display quality. The display device includes a pixel electrode, an EL layer, an upper electrode, a first insulating layer, a partition wall, and a transistor. The transistor is located below the pixel electrode, and is connected to the pixel electrode. The first insulating layer has an end portion on the pixel electrode. The partition wall is located on the first insulating layer. The EL layer contains a luminescent compound, and is in contact with the upper surface of the pixel electrode and with the upper surface of the first insulating layer. The upper electrode covers the upper surface and the end portion of the EL layer, and is in contact with the upper surface of the first insulating layer and with the side surface of the partition wall. The partition wall has a reverse-tapered shape in cross-sectional view, and is conductive. Additionally, in plan view, there is a gap between the end portion of the first insulating layer and the partition wall.

Description

Display device, method for manufacturing a display device

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

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

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

[0008] 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.

[0009] 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.

[0010] One aspect of the present invention is a display device comprising a pixel electrode, an EL layer, an upper electrode, a first insulating layer, a partition wall, and a transistor. The transistor is located below the pixel electrode and is connected to the pixel electrode. The first insulating layer has its ends on the pixel electrode. The partition wall is located on the first insulating layer. The EL layer contains a light-emitting compound and is in contact with the upper surface of the pixel electrode and the upper surface of the first insulating layer. The upper electrode covers the upper surface and ends of the EL layer and is in contact with the upper surface of the first insulating layer and the side surface of the partition wall. The partition wall has an inverse tapered shape in cross-section and is conductive. Furthermore, in plan view, there is a gap between the ends of the first insulating layer and the partition wall.

[0011] Another aspect of the present invention is a display device comprising a pixel electrode, an EL layer, an upper electrode, a first insulating layer, a partition wall, and a transistor. The transistor is located below the pixel electrode and is connected to the pixel electrode. The first insulating layer has its ends on the pixel electrode. The partition wall is located on the first insulating layer. The EL layer contains a light-emitting compound and is in contact with the upper surface of the pixel electrode and the upper surface of the first insulating layer. The upper electrode covers the upper surface and ends of the EL layer and is in contact with the upper surface of the first insulating layer and the side surface of the partition wall. In cross-sectional view, the partition wall has a shape in which the length of its upper side is longer than its lower side and is conductive. Furthermore, in plan view, there is a gap between the end of the first insulating layer and the partition wall.

[0012] Another aspect of the present invention is a display device comprising a pixel electrode, an EL layer, an upper electrode, a first insulating layer, a partition wall, and a transistor. The transistor is located below the pixel electrode and is connected to the pixel electrode. The first insulating layer has its ends on the pixel electrode. The partition wall is located on the first insulating layer. The EL layer contains a light-emitting compound and is in contact with the upper surface of the pixel electrode and the upper surface of the first insulating layer. The upper electrode covers the upper surface and ends of the EL layer and is in contact with the upper surface of the first insulating layer and the side surface of the partition wall. In cross-sectional view, the partition wall has a hexagonal shape with a first portion having an inverse tapered shape and a second portion on the first portion, and is conductive. Furthermore, in plan view, there is a gap between the end of the first insulating layer and the partition wall.

[0013] Another aspect of the present invention is a display device comprising 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 first insulating layer, a partition wall, and a transistor. The transistor is located below the first pixel electrode and is connected to the first pixel electrode. The first insulating layer has ends on the first pixel electrode and on the second pixel electrode. The partition wall is located on the first insulating layer. The first EL layer contains a first luminescent compound and is in contact with the upper surface of the first pixel electrode and the upper surface of the first insulating layer. The second EL layer contains a second luminescent compound and is in contact with the upper surface of the second pixel electrode and the upper surface of the first insulating layer. The first upper electrode covers the upper surface and ends of the first EL layer and is in contact with the upper surface of the first insulating layer and a part of the 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 the upper surface of the first insulating layer and other parts of the sides of the partition wall. The partition wall has an inverse tapered shape in cross-section and is conductive. Furthermore, in plan view, there is a gap between the edges of the first insulating layer and the partition wall.

[0014] Furthermore, in any of the above, it is preferable that the angle between the contact surface of the partition wall with the first insulating layer and the side surface of the partition wall is 95 degrees or more and 150 degrees or less.

[0015] Alternatively, in either of the above, it is preferable that the angle between the contact surface of the partition wall with the first insulating layer and the side surface of the partition wall is 105 degrees or more and 175 degrees or less.

[0016] Furthermore, in any of the above, it is preferable that the partition wall contains indium.

[0017] Furthermore, in any of the above, it is preferable that the transistor contains a metal oxide in the semiconductor layer where the channel is formed.

[0018] Another aspect of the present invention is a method for manufacturing a display device, comprising: forming a first insulating layer covering a portion of a first pixel electrode and a portion of a second pixel electrode; forming a first conductive film on the first pixel electrode, the second pixel electrode, and the first insulating layer; removing a portion of the first conductive film to create a reverse tapered shape, while exposing a portion of the upper surface of the first pixel electrode and the upper surface of the first insulating layer; forming a first EL layer on the first pixel electrode and a second EL layer on the first conductive film that is physically separated from the first EL layer; forming an upper electrode covering the first EL layer and in contact with the side surface of the first conductive film; forming a protective layer covering the upper electrode; etching the second EL layer so that the end of the second EL layer is located on the first conductive film; removing another portion of the first conductive film to create a reverse tapered shape, while exposing a portion of the upper surface of the second pixel electrode and the upper surface of the first insulating layer.

[0019] Furthermore, in the above manufacturing method, the protective layer is preferably formed by atomic layer deposition. Moreover, it is preferable that the protective layer covers the side surface of the first conductive film.

[0020] Furthermore, in the above manufacturing method, it is preferable that the processing of the first conductive film be carried out by a wet etching method.

[0021] According to one aspect of the present invention, it is possible to provide a display device that is easily made high-resolution, and a method for manufacturing the same. Alternatively, it is possible to provide a display device that combines high display quality and high resolution. Alternatively, it is possible to provide a display device with high contrast. Alternatively, it is possible to provide a highly reliable display device.

[0022] Furthermore, according to one aspect of the present invention, a display device having a novel configuration, or a method for manufacturing a display device, can be provided. Alternatively, a method for manufacturing the above-mentioned display device with a high yield can be provided. According to one aspect of the present invention, at least one of the problems of the prior art can be mitigated.

[0023] 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.

[0024] Figures 1A and 1B show examples of the configuration of a display device. Figures 2A and 2B 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, 4B, 4C, 4D, 4E, 4F, 4G, 4H, and 4I show examples of the configuration of a display device. Figures 5A, 5B, and 5C show examples of the configuration of a display device. Figures 6A, 6B, 6C, 6D, 6E, and 6F illustrate examples of methods for manufacturing a display device. Figures 7A, 7B, 7C, 7D, and 7E illustrate examples of methods for manufacturing a display device. Figures 8A, 8B, 8C, 8D, and 8E illustrate examples of methods for manufacturing a display device. Figures 9A and 9B illustrate examples of methods for manufacturing a display device. Figures 10A, 10B, 10C, 10D, and 10E 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, 12B, 12C, and 12D illustrate examples of methods for manufacturing a display device. Figures 13A, 13B, 13C, and 13D illustrate examples of methods for manufacturing a display device. Figures 14A and 14B show examples of the configuration of a display device manufacturing apparatus. Figure 15 shows an example 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. Figures 18A and 18B show examples of the configuration of a display device. Figures 19A and 19B show examples of the configuration of a display device. Figure 20 shows an example 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. Figures 23A, 23B, 23C, 23D, 23E, and 23F show examples of light-emitting device configurations. Figures 24A, 24B, and 24C show examples of light-emitting device configurations. Figures 25A, 25B, 25C, and 25D show examples of electronic device configurations. Figures 26A, 26B, 26C, 26D, 26E, and 26F show examples of electronic device configurations. Figures 27A, 27B, 27C, 27D, 27E, 27F, and 27G show examples of electronic device configurations. Figures 28A and 28B show examples of electronic device configurations. Figure 28C shows an electronic device in use.

[0025] 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.

[0026] In the invention described below, the same reference numerals are used in common across different drawings for identical parts or parts having similar functions, and repeated explanations are omitted. Furthermore, when referring to similar functions, the same hatching pattern may be used, and reference numerals may not be assigned.

[0027] 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.

[0028] 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.

[0029] 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."

[0030] 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.

[0031] In the following, expressions indicating directions such as "up" and "down" are basically used in accordance with the directions in the drawings. However, for the purpose of facilitating explanations or the like, the directions indicated by "up" or "down" in the specification may not match the drawings. As an example, when explaining the stacking order (or formation order) of a laminate or the like, even if the surface (formed surface, support surface, adhesive surface, flat surface, etc.) on which the laminate is provided in the drawing is located above the laminate, the formed surface side may be expressed as "down" and the laminate side as "up".

[0032] In this specification and the like, the terms "film" and "layer" can be interchanged with each other. For example, the term "insulating layer" may be interchangeable with the term "insulating film" in some cases.

[0033] In this specification, the EL layer refers to a layer provided between a pair of electrodes of a light-emitting element and containing at least a light-emitting substance (also referred to as a light-emitting layer), or a laminate including the light-emitting layer.

[0034] In this specification and the like, a display panel substrate to which a connector such as an FPC (Flexible Printed Circuit) or a TCP (Tape Carrier Package) is attached, or a substrate on which an IC is mounted by a COG (Chip On Glass) method or the like may be referred to as a display panel module, a display module, or simply a display panel.

[0035] (Embodiment 1) In this embodiment, a configuration example of a display device according to an aspect of the present invention and an example of its manufacturing method will be described.

[0036] One aspect of the present invention is a display device having a light-emitting element (also referred to as a light-emitting device). The display device has at least two light-emitting elements with different emission colors. Each light-emitting element has a pair of electrodes and an EL layer therebetween. Each light-emitting element is preferably an organic EL element (organic electroluminescent element). Two or more light-emitting elements with different emission colors have EL layers containing different materials. For example, by having three types of light-emitting elements that emit red (R), green (G), or blue (B) light respectively, a full-color display device can be realized.

[0037] Here, when forming part or all of the EL layer separately between light-emitting elements with different emission colors, it is known to form by vapor deposition using a shadow mask such as a metal mask. However, in this method, due to various influences such as the accuracy of the metal mask, the misalignment between the metal mask and the substrate, the deflection of the metal mask, and the spread of the contour of the film to be formed due to the scattering of vapor, deviations from the design occur in the shape and position of the island-shaped organic film, making it difficult to increase the definition and aperture ratio of the display device. Therefore, measures such as applying a special pixel arrangement method such as a pentile arrangement are taken to pseudo-increase the fineness (also referred to as pixel density).

[0038] One aspect of the present invention is to process the EL layer into a fine pattern without using a shadow mask such as a metal mask. Thereby, a display device with high definition and a large aperture ratio, which has been difficult to achieve so far, can be realized. Furthermore, since the EL layer can be separated, a display device with extremely vivid, high contrast, and high display quality can be realized.

[0039] One aspect of the present invention is to provide a partition for physically separating the EL layer between two adjacent light-emitting elements (the first light-emitting element, the second light-emitting element). The partition is a conductive structure having an inverted taper shape. It can also be said that the upper part of the partition has a shape that protrudes horizontally more than the lower part. The partition is formed so as to be located between two adjacent pixel electrodes. Also, the partition is provided so as to surround one pixel electrode. When the EL layer of the first light-emitting element is formed, a step is generated by the partition.

[0040] 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).

[0041] 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.

[0042] Subsequently, a resist mask is formed to cover the target pixel electrode and a portion of the partition wall, and the protective layer, upper electrode, and EL layer located in the areas not covered by the resist mask are removed by etching. At this time, the partition wall is left intact, eliminating the need to repeat the process of creating the partition wall. As a result, a laminated structure is formed in the region surrounded by the partition wall, consisting of a light-emitting element having a pixel electrode, an island-shaped EL layer, and an upper electrode in contact with the partition wall, and a protective layer covering the light-emitting element. The partition wall in contact with the upper electrode can also function as wiring to supply potential to the upper electrode.

[0043] By repeatedly performing the EL layer formation process followed by the etching process, different types of light-emitting elements can be created. This method allows for the creation of different light-emitting elements using photolithography, which enables microfabrication, without the need for a metal mask. As a result, display devices with extremely high resolution and a high aperture ratio can be manufactured.

[0044] While it is difficult to reduce the spacing between different colored EL layers to less than 10 μm using, for example, a metal mask formation method, the above method allows for narrowing the spacing to 3 μm or less, 2 μm or less, or even 1 μm or less. For example, by using an exposure apparatus for LSIs, the spacing can be narrowed to 500 nm or less, 200 nm or less, 100 nm or less, and even 50 nm or less. This significantly reduces the area of ​​the non-emitting region that may exist between two light-emitting elements, making it possible to approach an aperture ratio of 100%. For example, an aperture ratio of 50% or more, 60% or more, 70% or more, 80% or more, and even 90% or more, can be achieved, and even less than 100%.

[0045] 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.

[0046] Thus, according to the above manufacturing method, a display device with integrated fine light-emitting elements can be realized. Therefore, since there is no need to artificially increase the resolution using special pixel arrangement methods such as the PenTile method, a display device can be realized with a configuration in which three colored light-emitting elements are present in each pixel, 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.

[0047] Below, we will explain more specific examples with reference to the diagrams.

[0048] [Configuration Example] Figure 1A shows a schematic top view of the display device 100. The display device 100 has multiple red light-emitting elements 110R, multiple green light-emitting elements 110G, and multiple blue light-emitting elements 110B. In Figure 1A, the mutually orthogonal X and Y directions are indicated by arrows.

[0049] The light-emitting elements 110R, 110G, and 110B are each 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 arrangement method of the light-emitting elements 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.

[0050] It is preferable to use EL elements such as OLEDs (Organic Light Emitting Diodes) or QLEDs (Quantum-dot Light Emitting Diodes) as the light-emitting elements 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.

[0051] In this embodiment, when describing matters common to components distinguished by letters or numbers attached to their reference numerals (such as EL layer 112R and EL layer 112G), the reference numerals (such as EL layer 112) may be used without further explanation.

[0052] Furthermore, partition walls 120 are provided between each light-emitting element 110. The partition walls 120 have a grid-like upper surface shape. It can also be said that the light-emitting elements 110 are provided in the region surrounded by the partition walls 120.

[0053] As shown in Figure 1A, in a plan view, a gap is provided between the partition wall 120 and the light-emitting element 110. Figure 1A shows the gap Sx in the X direction and the gap Sy in the Y direction between the light-emitting element 110 and the partition wall 120.

[0054] 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 light-emitting element 110R, a light-emitting element 110G, and a light-emitting element 110B.

[0055] 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 a source electrode and a drain electrode. 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.

[0056] It is preferable to use a metal oxide (also called an oxide semiconductor) that exhibits semiconductor properties as the semiconductor layer 151. As the oxide semiconductor, an oxide semiconductor such as indium oxide or In-Ga-Zn oxide (IGZO) can be used. 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.).

[0057] 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 gallium oxide, indium tungsten oxide, indium zinc 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 zinc oxide, indium gallium tin zinc oxide, and indium gallium aluminum zinc oxide. Alternatively, silicon-containing indium tin oxide, gallium tin oxide, aluminum tin oxide, etc., can also be used.

[0058] 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.

[0059] An insulating layer 132 is provided covering the conductive layer 154 and the insulating layer 131, and light-emitting elements 110R, 110G, and 110B are provided on the insulating layer 132.

[0060] The light-emitting element 110R has an EL layer 112R between the pixel electrode 111R and the upper electrode 113R. The light-emitting element 110G has an EL layer 112G between the pixel electrode 111G and the upper electrode 113G. The light-emitting element 110B has an EL layer 112B between the pixel electrode 111B and the upper electrode 113B.

[0061] Each pixel electrode 111 is provided on an insulating layer 132 and is connected to a conductive layer 154 at an opening in the insulating layer 132. As a result, each pixel electrode 111 is connected to either the source electrode or the drain electrode of the transistor 150.

[0062] The EL layer 112R of the light-emitting element 110R has a light-emitting organic compound that emits at least red light. The EL layer 112G of the light-emitting element 110G has a light-emitting organic compound that emits at least green light. The EL layer 112B of the light-emitting element 110B has a light-emitting organic compound that emits at least blue light.

[0063] Each of the EL layers 112R, 112G, and 112B may have, in addition to a layer containing a light-emitting organic compound (light-emitting layer), 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.

[0064] 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 display device can also be created.

[0065] Furthermore, protective layers 135R, 135G, and 135B are provided to cover the upper electrodes 113R, 113G, and 113B, respectively.

[0066] Each protective layer 135 can be, for example, a single-layer structure or a multi-layer structure including at least an inorganic insulating film. Examples of inorganic insulating films include oxide films or nitride films such as silicon oxide film, silicon oxide nitride film, silicon oxide nitride film, silicon nitride film, aluminum oxide film, aluminum oxide nitride film, and hafnium oxide film. Alternatively, semiconductor materials such as indium gallium oxide and indium gallium zinc oxide may be used as the protective layer 135. Aluminum oxide and silicon nitride are particularly preferred due to their high barrier properties against water.

[0067] In this specification, the term "oxidogenic nitride" refers to a material in which the oxygen content is greater than the nitrogen content, and the term "nitride oxide" refers to a material in which the nitrogen content is greater than the oxygen content.

[0068] 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.

[0069] 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.

[0070] 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.

[0071] 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.

[0072] 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.

[0073] 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.

[0074] 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.

[0075] A partition wall 120 is provided on the insulating layer 133. The partition wall 120 is conductive and has an inverse tapered shape.

[0076] Figure 2B shows an enlarged view of the light-emitting element 110R, the light-emitting element 110G, the partition wall 120 located between them, and the vicinity thereof.

[0077] The ends of the EL layer 112R and EL layer 112G are located on the insulating layer 133. The upper electrode 113R covers the end of the EL layer 112R and is in contact with the upper surface of the insulating layer 133 and a part of the side surface of the partition wall 120. Similarly, the upper electrode 113G covers the end of the EL layer 112G and is in contact with the upper surface of the insulating layer 133 and a part of the side surface of the partition wall 120.

[0078] 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 may be 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. In some cases, an EL layer 112Ra is provided between the partition wall 120 and the upper electrode 113R, and an EL layer 112Ga is provided between the partition wall 120 and the upper electrode 113G.

[0079] Since the upper electrode 113R and the upper electrode 113G are in contact with the conductive partition wall 120, it can be said that they are connected via the partition wall 120. Furthermore, as shown in Figure 1A, the partition wall 120 is arranged in a grid pattern so as to weave between the light-emitting elements 110, so the upper electrodes 113 of all light-emitting elements 110 are connected via the partition wall 120. In addition, the partition wall 120 also functions as wiring that supplies potential to the upper electrodes 113 of each light-emitting element 110.

[0080] As shown in Figure 2B, the insulating layer 133 has its edges located on the pixel electrode 111R and the pixel electrode 111G, respectively. The gap Sx corresponds to the space between the edge of the insulating layer 133 and the edge of the most protruding part of the partition wall 120. The gap Sx can also be described as the region between the edge of the light-emitting region of the light-emitting element 110R and the edge of the most protruding part of the partition wall 120. Furthermore, as shown in Figures 1A and 2B, in a plan view, the width of the gap Sx is, for example, the distance between the edge of the light-emitting region of the light-emitting element 110 and the edge of the partition wall 120. The presence of the gap Sx allows the EL layer 112 to be formed such that the stepped edge of the EL layer 112, which is separated by the partition wall 120, is located on the insulating layer 133 and not on the pixel electrode 111 during film formation. For example, if the edge of the EL layer 112 is located 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 edge of the insulating layer 133 and the partition wall 120 in order to ensure that the edge of the EL layer 112 is reliably located on the insulating layer 133. The same applies to the gap Sy.

[0081] Preferably, the height h of the partition wall 120 is greater than the thickness of the thickest film among the EL layers 112R, 112G, and 112B. 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. Specifically, for example, it is conceivable that the upper electrode 113 will have difficulty fitting between the EL layer 112 and the partition wall 120. Also, the closer the taper angle θ is to 180 degrees, the easier it is for the EL layer 112 to be stepped, while it becomes difficult to bring the upper electrode 113 and the partition wall 120 into contact. Therefore, the taper angle θ can be, for example, 95 degrees or more and 150 degrees or less, preferably 100 degrees or more and 135 degrees or less. Furthermore, if the coverage of the upper electrode 113 is sufficiently high, an even larger taper angle θ can be used. For example, the taper angle θ can be 105 degrees or more and 175 degrees or less, preferably 120 degrees or more and 170 degrees or less.

[0082] Here, the taper angle θ is shown as the angle between the bottom and side surfaces of the partition wall 120. However, as shown in Figure 2B, it can also be expressed as the angle (taper angle θ') between the side surface of the partition wall 120 and the upper surface of the underlayment (insulating layer 133 in this case) that does not come into contact with the partition wall 120. In that case, θ' can be expressed as θ' ​​= 180 degrees - θ (where both θ and θ' are between 0 and 180 degrees). That is, the preferred range for the taper angle θ' can be expressed as 30 degrees to 85 degrees, 45 degrees to 80 degrees, 5 degrees to 75 degrees, or 10 degrees to 60 degrees. The choice of which angle to use to express the taper angle can be made by considering the surface shape of the underlayment (e.g., insulating layer 133) and selecting the one that is easier to measure.

[0083] 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.

[0084] 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.

[0085] This configuration allows for the creation of different EL layers between adjacent light-emitting elements, effectively eliminating leakage current through the EL layers compared to cases where the EL layers are in contact or a common EL layer is used. 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 does not require the use of a metal mask, and all processing of the EL layer 112 and other components 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.

[0086] Figure 2A 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 3A shows an example in which the insulating layer 133 is not provided. In Figure 3A, 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.

[0087] 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 3B shows an example where the cross-sectional width of the partition wall 120 is greater than its height.

[0088] Furthermore, while Figure 2A and other figures show an example where the upper electrode 113 is continuous from the side to the top of the partition wall 120 without being stepped by the partition wall 120, the upper electrode 113 may be stepped. Figure 3C shows an example where the upper electrode 113 is stepped. In this case, the partition wall 120 has a conductive layer 113Ra covering the side and top surfaces of the EL layer 112Ra, and a conductive layer 113Ga covering the side and top surfaces of the EL layer 112Ga. The conductive layers 113Ra and 113Ga contain the same material as the upper electrode 113R or upper electrode 113G. The protective layer 135R and protective layer 135G each have portions that are in contact with the side surface of the partition wall 120. With this configuration, the entire upper electrode 113, including its end, can be covered by the protective layer 135 and the partition wall 120. This prevents water or other substances from diffusing to the light-emitting element 110 from the outside via the upper electrode 113, and also prevents the upper electrode 113 itself from deteriorating.

[0089] The partition wall 120 shown in Figure 2B, etc., is an example having an inverse tapered shape. The shape of the partition wall 120 exemplified in Figure 2B, etc., can also be described as having a roughly trapezoidal shape in cross-section, where the length of the upper base is longer than the length of the lower base. However, the shape of the partition wall 120 is not limited to this, and various shapes can be taken if the EL layer 112 can be stepped. The partition wall 120 can also have a symmetrical shape in cross-section. If the upper surface of the partition wall 120 is flat, the shape of the partition wall 120 in cross-section will be a polygon with an even number of corners. Examples of other cross-sectional shapes of the partition wall 120 will be described below.

[0090] The examples shown in Figures 4A and 4B are cases where the side surface of the partition wall 120 has a curved shape. In Figure 4A, it has a concave curved surface, and in Figure 4B, it has a convex curved surface.

[0091] When the side surface of the partition wall 120 has a curved shape, it is difficult to uniquely determine the taper angle θ. In such cases, as shown in Figures 4A and 4B, a straight line connecting the point of the widest part of the partition wall 120 in a cross-sectional view and the point of the end of the contact surface between the partition wall 120 and the underlying film (insulating layer 133) can be assumed to be a hypothetical side surface of the partition wall 120, and the angle between this straight line and the contact surface between the partition wall 120 and the underlying film (insulating layer 133) can be defined as the taper angle θ.

[0092] Here, the partition wall 120 only needs to have a tapered shape in a portion including at least the part that is in contact with the substrate film, and the shape of the part above that is not specified. As shown in Figure 4C, the partition wall 120 can be divided into a lower part 120B (also called the first part) which has a tapered shape, and an upper part 120T (also called the second part) which is located above the lower part 120B. Since the upper part 120T can take various shapes, its shape is not explicitly shown here and is indicated by a dashed line. Below, examples of upper parts 120T with different shapes will be described.

[0093] Figure 4D shows an example where the upper part 120T has a rectangular shape in cross-section. Figures 4E and 4F show examples where the upper part 120T has a trapezoidal shape in cross-section, where the length of the upper side (also called the upper base) is shorter than the length of the lower side (also called the lower base). Figure 4E shows an example where the thickness of the upper part 120T is thinner than the lower part 120B, and Figure 4F shows an example where the thicknesses of the upper part 120T and the lower part 120B are roughly the same. The partition walls 120 shown in Figures 4D, 4E, and 4F can also be said to have a hexagonal shape in cross-section.

[0094] Figure 4G shows an example where the partition wall 120 has an octagonal shape in cross-sectional view. In Figure 4G, a portion of the side surface of the partition wall 120 is approximately perpendicular to the surface to be formed.

[0095] Figures 4H and 4I are modified examples of Figures 4A and 4B, respectively, and are examples having a curved lower part 120B and an upper part 120T that has a trapezoidal shape in cross-sectional view.

[0096] Although the above shows that the side surface of the partition wall 120 has corners, depending on the processing method of the partition wall 120, the corners may be rounded. In particular, when the partition wall 120 is formed by an isotropic etching method such as wet etching, the corners tend to be rounded.

[0097] The above is an explanation of the example configuration.

[0098] [Modification] In the above example, the display device 100 is shown to have three colored light-emitting elements 110 (light-emitting element 110R, light-emitting element 110G, and light-emitting element 110B), but it may have further elements.

[0099] Figures 5A and 5B show an example in which, in addition to the red, green, and blue light-emitting elements 110, there is also a white light-emitting element 110W. Figure 5A is a top view, and Figure 5B is a schematic cross-sectional view along the cutting line C-D in Figure 5A.

[0100] The light-emitting element 110W has a pixel electrode 111W, an EL layer 112W, and an upper electrode 113W. A protective layer 135W is also provided covering the light-emitting element 110W.

[0101] The EL layer 112W can have a configuration having two or more light-emitting layers. For example, white light can be obtained by combining two light-emitting layers such that their light-emitting colors are complementary. Alternatively, it may have a configuration having three or more light-emitting layers.

[0102] By using white light-emitting elements in addition to red, green, and blue light-emitting elements, it is possible to improve contrast and reliability.

[0103] Figure 5C shows an example where a light-receiving element 110S is used instead of the light-emitting element 110W.

[0104] The light-receiving element 110S functions as a photoelectric conversion element and can output an electrical signal corresponding to the amount of incident light. This allows the image sensor to be incorporated into the display device 100. Figure 5C shows the light R, light G, and light B emitted by the light-emitting elements 110R, 110G, and 110B, respectively, and the light L incident on the light-receiving element 110S from the outside. ｅｘ The direction of each is indicated by an arrow.

[0105] The light-receiving element 110S includes a pixel electrode 111S, a sensor layer 112S, and an upper electrode 113S. A protective layer 135S is also provided covering the light-receiving element 110S.

[0106] The sensor layer 112S preferably has an organic layer common to the EL layer 112R, etc. For example, the light-emitting layer of the EL layer 112R can be replaced with a light-receiving layer (also called an active layer or photoelectric conversion layer).

[0107] The light-receiving layer of the sensor layer 112S can be a stacked structure in which a p-type semiconductor and an n-type semiconductor are stacked to realize a pn junction, or a stacked structure in which a p-type semiconductor, an i-type semiconductor, and an n-type semiconductor are stacked to realize a pin junction.

[0108] As the semiconductor used for the light-receiving layer, an inorganic semiconductor such as silicon or an organic semiconductor containing an organic compound can be used. In particular, using an organic semiconductor material is preferable because it makes it easy to form the EL layer 112R and the light-receiving layer using the same vacuum deposition method, and the manufacturing equipment can be shared.

[0109] When using an organic semiconductor material as the light-receiving layer, the n-type semiconductor material can be fullerene (for example, C ６０ , C ７０ Electron-accepting organic semiconductor materials such as (etc.) or their derivatives can be used. In addition, electron-donating organic semiconductor materials such as copper(II) phthalocyanine (CuPc) and tetraphenyldibenzoperifuranthene (DBP) can be used as the p-type semiconductor material. The light-receiving layer may be a stacked structure of an electron-accepting semiconductor material and an electron-donating semiconductor material (p-n stacked structure), or a stacked structure with a bulk heterostructure layer in which an electron-accepting semiconductor material and an electron-donating semiconductor material are co-deposited between them (p-i-n stacked structure). Furthermore, in order to suppress dark current when light is not irradiated, a layer that functions as a hole-blocking layer, a layer that functions as an electron-blocking layer, etc. may be provided around (above or below) the above-mentioned p-n stacked structure or p-i-n stacked structure.

[0110] The above is an explanation of the variations.

[0111] [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 6A to 8E are schematic cross-sectional views of each step in the manufacturing method of the display device illustrated below.

[0112] 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).

[0113] 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.

[0114] 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.

[0115] CVD methods can be classified into plasma-enhanced CVD (PECVD), which utilizes plasma; thermal CVD (TCD), which utilizes heat; and 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).

[0116] 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.

[0117] 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.

[0118] 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.

[0119] 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.

[0120] 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.

[0121] 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.

[0122] 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.

[0123] 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.

[0124] 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.

[0125] First, a substrate 101 is prepared, and transistors 150, insulating layer 131, insulating layer 132, etc. are formed. Next, a conductive film is deposited on the insulating layer 132, and unnecessary parts are removed by etching to form pixel electrodes 111R, pixel electrode 111G, and pixel electrode 111B.

[0126] 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.

[0127] Next, an insulating layer 133 is formed by covering the ends of each pixel electrode 111 (Figure 6A). 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.

[0128] 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.

[0129] Next, a resist mask 141 is formed on the conductive film 120f (Figure 6B). 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 6C).

[0130] 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. Wet etching is particularly preferable because it excels in isotropic etching and exhibits good processability even when the conductive film 120f is thin. 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.

[0131] 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.

[0132] Next, an EL layer 112R is deposited on each pixel electrode 111 and the partition wall 120 (Figure 6D). At this time, the EL layer 112R is stepped by the partition wall 120, and is formed between the two regions of the partition wall 120 and on top of the partition wall 120. The EL layer 112R can be formed using, for example, vacuum deposition, sputtering, or both.

[0133] The method for forming the EL layer 112R will be explained using Figures 9A and 9B. It is preferable to form the EL layer 112R using a highly anisotropic film formation method. That is, as shown in Figure 9A, 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 9B. At this time, it is preferable that sufficient space is secured between the EL layer 112R and the partition wall 120 for the upper electrode 113R to fit into.

[0134] Next, the upper electrode 113R is formed by covering the EL layer 112R, etc. (Figure 6E). At this time, the upper electrode 113R is formed so as to cover the edge of the EL layer 112R and to be in contact with at least a part of the side surface of the partition wall 120. The upper electrode 113R can be formed using one or more of the following methods: vacuum deposition, sputtering, and CVD.

[0135] The method for forming the upper electrode 113R will be explained using Figures 10A to 10E. It is preferable to form the upper electrode 113R using a film formation method with lower anisotropy than that of the EL layer 112R. 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 113R 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).

[0136] Furthermore, as shown in Figure 10A, 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 perpendicular to the substrate surface. In Figure 10A, 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.

[0137] Alternatively, as shown in Figure 10B, a film deposition apparatus may be used that has a mechanism in which the substrate 101 rotates (or 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.

[0138] By using a film deposition apparatus having a mechanism like those shown in Figures 10A and 10B, as shown in Figure 10C, the film deposition process of the upper electrode 113R 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 in the opposite direction, as shown in Figure 10D. Therefore, as shown in Figure 10E, the upper electrode 113R can also be deposited on the side surface of the partition wall 120 which has an inverse tapered shape.

[0139] 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.

[0140] Subsequently, a protective layer 135R is formed to cover the upper electrode 113R (FIG. 6F). The protective layer 135R is preferably formed by a film-forming method with high step coverage, and preferably formed by CVD method or ALD method. In particular, the ALD method is preferable because the film-forming damage to the formed layer is small.

[0141] For example, as the protective layer 135R, an aluminum oxide film can be formed by the ALD method. At this time, as the precursor containing aluminum, trimethylaluminum, triethylaluminum, triisobutylaluminum, dimethylaluminum hydride, tris(dimethylamino)aluminum, tris(diethylamino)aluminum, aluminum trichloride, etc. are preferably used. Further, as the oxidant serving as a reactant, 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 ) etc. can be used, and two or more of these may be used.

[0142] Further, as the protective layer 135R, a laminated structure of a film formed by the ALD method and a film formed by a film-forming method other than the ALD method (for example, CVD method, sputtering method, etc.) may be used. Since the ALD method has extremely high step coverage while the film-forming speed is relatively slow compared to other film-forming methods, after first forming a film with extremely few defects by the ALD method, a thick insulating film is formed by the CVD method or the like, thereby shortening the time required for the film-forming process of the protective layer 135R.

[0143] Subsequently, a resist mask 141a is formed (FIG. 7A). The resist mask 141a is formed such that the end portion is located above the portion surrounding the pixel electrode 111R in the partition wall 120. As described above, in FIG. 1(A) etc., the partition wall 120 has a lattice-shaped upper surface shape, and the light-emitting element 110 is provided in the region surrounded by the partition wall 120.

[0144] Next, the portions of the protective layer 135R, upper electrode 113R, and EL layer 112R that are not covered by the resist mask 141a are removed by etching (Figure 7B). After that, the resist mask 141a is removed (Figure 7C). At this point, parts of the protective layer 135R, upper electrode 113R, and EL layer 112R remain on the upper part of the partition wall 120. Note that some parts of the EL layer 112R on the partition wall 120 may have disappeared.

[0145] As a result, the light-emitting element 110R and the protective layer 135R can be formed.

[0146] Next, the EL layer 112G, the upper electrode 113G, and the protective layer 135G are deposited in order (Figure 7D). The deposition methods for the EL layer 112G, the upper electrode 113G, and the protective layer 135G can be the same as those for the EL layer 112R, the upper electrode 113R, and the protective layer 135R, respectively.

[0147] Next, the resist mask 141b is formed (Figure 7E). The resist mask 141b is formed such that its end is located at the top of the portion of the partition wall 120 that surrounds the pixel electrode 111G.

[0148] Next, the portions of the protective layer 135G, the upper electrode 113G, and the EL layer 112G that are not covered by the resist mask 141b are removed by etching (Figure 8A). After that, the resist mask 141b is removed (Figure 8B). During etching of the EL layer 112G, the EL layer 112R and the pixel electrode 111R are covered by the protective layer 135R and are therefore not damaged. As a result, the light-emitting element 110G can be fabricated.

[0149] Next, the EL layer 112B, the upper electrode 113B, and the protective layer 135B are deposited in order. The deposition methods for the EL layer 112B, the upper electrode 113B, and the protective layer 135B can be the same as those for the EL layer 112R, the upper electrode 113R, and the protective layer 135R, respectively.

[0150] Next, the resist mask 141c is formed (Figure 8C). The resist mask 141c is formed such that its end is located at the top of the portion of the partition wall 120 that surrounds the pixel electrode 111B.

[0151] Next, the portions of the protective layer 135B, the upper electrode 113B, and the EL layer 112B that are not covered by the resist mask 141c are removed by etching (Figure 8D). After that, the resist mask 141c is removed (Figure 8E). This allows the light-emitting element 110B to be fabricated.

[0152] The display device 100 can be manufactured through the above process.

[0153] [Example of Manufacturing Method 2] Below, we will describe an example of a manufacturing method that differs in some steps from Example of Manufacturing Method 1 described above. Note that explanations of parts that overlap with the above will be omitted, and the above may be referred to.

[0154] In the above example of the manufacturing method 1, an example was shown in which the photolithography process is performed a total of four times: once for forming the partition wall 120 and once for forming each light-emitting element. Below, an example is described in which the photolithography process is performed a total of six times, by forming the partition wall 120 once before forming each light-emitting element.

[0155] Figures 11A to 11D show schematic cross-sectional views of each stage in the example manufacturing method illustrated below. Here, the right side of each figure also shows a cross-section of the region where a conductive layer 115, which functions as wiring connecting to the partition wall 120, is provided. A constant potential can be applied to the conductive layer 115, and this potential can be supplied to each upper electrode 113 via the partition wall 120.

[0156] First, as described above, pixel electrodes 111R, 111G, 111B, a conductive layer 115, and an insulating layer 133 are formed on the insulating layer 132 (Figure 11A). The conductive layer 115 can be formed by processing the same conductive film as each pixel electrode 111. Alternatively, the conductive layer 115 and each pixel electrode 111 may be formed using different conductive films. After that, a conductive film 120f, which will later become the partition wall 120, is deposited.

[0157] Next, a resist mask 141 is formed on the conductive film 120f (Figure 11B). Here, the resist mask 141 is formed to cover the pixel electrode 111G, the pixel electrode 111B, and the conductive layer 115. In a plan view, the resist mask 141 is an island-shaped pattern that encompasses the display area where all the pixel electrodes 111 are provided and the conductive layer 115 provided around it, and can be a pattern with openings provided in the area overlapping with the pixel electrode 111R. The right side of Figure 11B shows the edge of the resist mask 141. This edge is located outside the area where the conductive layer 115 is provided.

[0158] Next, the portion of the conductive film 120f not covered by the resist mask 141 is etched to form a partition wall 120, and the resist mask 141 is removed (Figure 11C). The right side of Figure 11C shows the end of the partition wall 120.

[0159] Next, the EL layer 112R, the upper electrode 113R, and the protective layer 135R are formed in the same manner as described above (Figure 11D). Subsequently, a resist mask 141a is formed (Figure 11E), and the portions of the EL layer 112R, the upper electrode 113R, and the protective layer 135R that are not covered by the resist mask 141a are removed by etching (Figure 12A).

[0160] In this configuration, the pixel electrodes 111G and 111B are covered by the partition wall 120, preventing them from being exposed to the etching atmosphere such as the EL layer 112R. As a result, the upper surfaces of the pixel electrodes 111G and 111B are not damaged by the etching, enabling the realization of a highly reliable display device. Furthermore, since the EL layer 112R, the upper electrode 113R, and the protective layer 135R are formed on the generally flat upper surface of the partition wall 120, the resulting configuration is less prone to etching residue compared to the first manufacturing method example, thereby improving yield.

[0161] At this point, the light-emitting element 110R can be formed.

[0162] Next, a resist mask (not shown) is formed by covering the protective layer 135R and the partition wall 120, and the area of ​​the partition wall 120 that overlaps with the pixel electrode 111G is removed by etching, exposing the upper surface of the pixel electrode 111G and a part of the upper surface of the insulating layer 133 (Figure 12B).

[0163] Next, the EL layer 112G, the upper electrode 113G, and the protective layer 135G are formed in the same manner as described above (Figure 12C). After that, unnecessary portions of the EL layer 112G, the upper electrode 113G, and the protective layer 135B are removed by etching in the same manner as described above (Figure 12D). Even at this time, the pixel electrode 111B is covered by the partition wall 120 and is therefore not exposed to the etching atmosphere.

[0164] At this point, the light-emitting element 110G can be formed.

[0165] Next, a portion of the partition wall 120 is etched in the same manner as described above, exposing the pixel electrode 111B and a portion of the upper surface of the insulating layer 133 (Figure 13A). After that, the EL layer 112B, the upper electrode 113B, and the protective layer 135B are formed (Figure 13B), and any unnecessary parts of these are removed by etching (Figure 13C).

[0166] Through the above process, the light-emitting element 110R, light-emitting element 110G, and light-emitting element 110B can be formed. By using this method, although the number of photolithography steps is increased compared to manufacturing method example 1, a highly reliable display device can be manufactured with a high yield.

[0167] Subsequently, a protective layer 136 may be formed to cover each light-emitting element 110 (Figure 13D). By providing the protective layer 136, the upper surface of the partition wall 120 and the end faces of each upper electrode 113 are not exposed, thereby improving reliability. The protective layer 136 can be formed in the same manner as each protective layer 135. In particular, it is preferable to form a highly waterproof insulating film, such as an aluminum oxide film, as the protective layer 136 by the ALD method.

[0168] The above is an explanation of example manufacturing method 2.

[0169] [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 contact with the atmosphere will be described. The film deposition apparatus exemplified below can be used as a manufacturing apparatus for display devices. The film deposition apparatus exemplified below can be used for forming the EL layer 112, upper electrode 113, and protective layer 135 in each light-emitting element 110.

[0170] A schematic diagram of the film deposition apparatus is shown in Figure 14A. 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 can also be called chambers.

[0171] 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.

[0172] 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.

[0173] 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.

[0174] 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.

[0175] 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.

[0176] In the deposition chamber SP, the upper electrode 113 can be deposited. For example, the deposition chamber SP has a sputtering apparatus.

[0177] In the ALD deposition chamber, a protective layer 135 can be deposited. The ALD deposition chamber includes, for example, an ALD apparatus.

[0178] Although Figure 14A shows an example with one transport chamber TF, a configuration in which multiple transport chambers TF are connected is also possible. Figure 14B 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 14B, four to six rooms can be connected to one transport chamber TF, excluding the loading room LL and the unloading room UL. In Figure 14B, up to three more rooms can be added depending on the application.

[0179] Next, an example of a film deposition method using a film deposition apparatus will be described. First, as shown in Figure 6C, 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. Then, the protective layer 135 is deposited in film deposition chamber ALD, and 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.

[0180] 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.

[0181] 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.

[0182] 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.

[0183] 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.

[0184] Figure 15 shows an example of a film deposition apparatus configuration different from the one described above. The film deposition apparatus shown in Figure 15 has a configuration in which three transport chambers (transport chamber TF1, transport chamber TF2, and transport chamber TF3) are connected.

[0185] 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 15, the loading chamber LL also serves as the unloading chamber, allowing substrates to be loaded and unloaded using the loading chamber LL.

[0186] 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 above description.

[0187] 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.

[0188] 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.

[0189] 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 Unfielded 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.

[0190] In the film deposition apparatus shown in Figure 15, 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.

[0191] The above is a description of the film deposition apparatus and the film deposition method using it.

[0192] (Embodiment 2) This embodiment describes an example of the configuration of a display device according to one aspect of the present invention.

[0193] 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.

[0194] [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.

[0195] 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.

[0196] 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.

[0197] For example, a scan line drive circuit can be used as circuit 464.

[0198] 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.

[0199] 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.

[0200] 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.

[0201] The display device 400A shown in Figure 17 has a transistor 201, a transistor 205, a light-emitting element 430a that emits red light, a light-emitting element 430b that emits green light, and a light-emitting element 430c that emits blue light, etc., between a substrate 451 and a substrate 452.

[0202] The light-emitting elements 430a, 430b, and 430c can be the light-emitting elements exemplified 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 having a different light-emitting layer, and an island-shaped upper electrode.

[0203] Here, if the pixels of the display device have three types of subpixels, each having a light-emitting element with a different emission color, 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 white (W); and subpixels of four colors: R, G, B, and Y.

[0204] Each 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), indicating a hollow sealing structure. 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 the adhesive layer 442.

[0205] The light-emitting elements 430a, 430b, and 430c have an optical adjustment layer between the pixel electrode and the EL layer. Light-emitting element 430a has an optical adjustment layer 426a, light-emitting element 430b has an optical adjustment layer 426b, and light-emitting element 430c has an optical adjustment layer 426c. Details of the light-emitting elements can be found in Embodiment 1. Each optical adjustment layer 426 has a different thickness. It is also preferable that each optical adjustment layer 426 is made of the same material that is transparent and conductive. It is preferable to use a conductive metal oxide film containing indium or zinc as the optical adjustment layer 426.

[0206] The pixel electrodes 411a, 411b, and 411c are connected to the conductive layer 222b of the transistor 205 through openings provided in the insulating layer 213, insulating layer 214, and insulating layer 215, respectively.

[0207] 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.

[0208] The light emitted by the light-emitting element is directed towards the substrate 452. It is preferable to use a material with high transparency to visible light for the substrate 452.

[0209] 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.

[0210] Both transistors 201 and 205 are formed on the substrate 451. These transistors can be manufactured using the same materials and the same process.

[0211] 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.

[0212] 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.

[0213] 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.

[0214] 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.

[0215] 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.

[0216] 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.

[0217] 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.

[0218] 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.

[0219] 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.

[0220] 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.

[0221] 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.).

[0222] The semiconductor layer preferably contains a metal oxide containing indium. In particular, it is especially preferable that it contains indium oxide.

[0223] 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.

[0224] 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.

[0225] 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.

[0226] 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.

[0227] 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.

[0228] 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.

[0229] 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.

[0230] By providing a protective layer 416 that covers the light-emitting element, it is possible to suppress the ingress of impurities such as water into the light-emitting element and improve the reliability of the light-emitting element.

[0231] 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.

[0232] 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.

[0233] Substrates 451 and 452 can be made of glass, quartz, ceramics, sapphire, resin, metal, alloy, semiconductor, etc., respectively. The substrate on the side that extracts light from the light-emitting element should be made of a material that transmits the light. Using flexible materials for substrates 451 and 452 can increase the flexibility of the display device. Alternatively, a polarizing plate may be used as substrate 451 or substrate 452.

[0234] As substrates 451 and 452, the following can be used: polyester resins such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN), polyacrylonitrile resin, acrylic resin, polyimide resin, polymethyl methacrylate resin, polycarbonate (PC) resin, polyethersulfone (PES) resin, polyamide resin (nylon, aramid, etc.), polysiloxane resin, cycloolefin resin, polystyrene resin, polyamide-imide resin, polyurethane resin, polyvinyl chloride resin, polyvinylidene chloride resin, polypropylene resin, polytetrafluoroethylene (PTFE) resin, ABS resin, cellulose nanofiber, etc. One or both of substrates 451 and 452 may be made of glass of a thickness sufficient to provide flexibility.

[0235] Furthermore, when a circular polarizing plate is superimposed on a display device, it is preferable to use a substrate with high optical isotropy for the substrate of the display device. A substrate with high optical isotropy has low birefringence (or a small amount of birefringence).

[0236] For substrates with high optical isotropy, the absolute value of the retardation (phase difference) is preferably 30 nm or less, more preferably 20 nm or less, and even more preferably 10 nm or less.

[0237] Examples of films with high optical isotropy include triacetylcellulose (TAC, also known as cellulose triacetate) film, cycloolefin polymer (COP) film, cycloolefin copolymer (COC) film, and acrylic film.

[0238] Furthermore, when using a film as the substrate, the film may absorb water, potentially causing wrinkles or other shape changes in the display panel. Therefore, it is preferable to use a film with low water absorption for the substrate. For example, it is preferable to use a film with a water absorption rate of 1% or less, more preferable to use a film with a water absorption rate of 0.1% or less, and even more preferable to use a film with a water absorption rate of 0.01% or less.

[0239] Various types of curing adhesives can be used as the adhesive layer, including UV-curing adhesives, reaction-curing adhesives, thermosetting adhesives, and anaerobic adhesives. Examples of these adhesives include epoxy resins, acrylic resins, silicone resins, phenolic resins, polyimide resins, imide resins, PVC (polyvinyl chloride) resins, PVB (polyvinyl butyral) resins, and EVA (ethylene vinyl acetate) resins. Materials with low moisture permeability, such as epoxy resins, are particularly preferred. Two-component mixed resins may also be used. Adhesive sheets may also be used.

[0240] As the connecting layer 242, an anisotropic conductive film (ACF), an anisotropic conductive paste (ACP), or the like can be used.

[0241] Materials that can be used for conductive layers such as the gate, source, and drain of transistors, as well as various wirings and electrodes that constitute display devices, include metals such as aluminum, titanium, chromium, nickel, copper, yttrium, zirconium, molybdenum, silver, tantalum, and tungsten, as well as alloys mainly composed of these metals. Films containing these materials can be used as single layers or in a multilayer structure.

[0242] 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).

[0243] 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.

[0244] [Display Device 400B] Figure 18A 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 18A 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 18A, an example of a cross-section is shown when a part of the display unit 462, in particular, including the light-emitting element 430b that emits green light and the light-emitting element 430c that emits blue light, is cut. Note that explanations of parts that are the same as those of the display device 400A may be omitted.

[0245] The display device 400B shown in Figure 18A has transistors 202, 210, light-emitting elements 430b, and 430c between substrates 453 and 454.

[0246] The substrate 454 and the protective layer 416 are bonded together via an adhesive layer 442. The adhesive layer 442 is provided in overlap with the light-emitting elements 430b and 430c, respectively, and a solid encapsulation structure is applied to the display device 400B.

[0247] The substrate 453 and the insulating layer 212 are bonded together by an adhesive layer 455.

[0248] 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.

[0249] 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.

[0250] 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 layer 215 and the insulating layer 225. The transistor 210 has the function of controlling the driving of the light-emitting element.

[0251] The ends of the pixel electrodes are covered by an insulating layer 421.

[0252] The light emitted by the light-emitting elements 430b and 430c is emitted towards the substrate 454. It is preferable to use a material with high transparency to visible light for the substrate 454.

[0253] 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.

[0254] 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.

[0255] 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.

[0256] Figure 18A shows an example in which the insulating layer 225 covers the top and sides 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.

[0257] On the other hand, in the transistor 209 shown in Figure 18B, 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 18B can be fabricated by processing the insulating layer 225 using the conductive layer 223 as a mask. In Figure 18B, 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.

[0258] 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.

[0259] This embodiment can be implemented in appropriate combination with other embodiments described herein, at least in part.

[0260] (Embodiment 3) In this embodiment, an example of a display device configuration different from that described above will be explained.

[0261] 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.

[0262] [Display Module] Figure 19A 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, which will be described later.

[0263] 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.

[0264] Figure 19B shows a schematic perspective view illustrating the configuration of 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 on the substrate 291. A terminal section 285 for connecting to the FPC 290 is provided in a portion of the substrate 291 that does not overlap with the pixel section 284. The terminal section 285 and the circuit section 282 are electrically connected by a wiring section 286, which is composed of multiple wires.

[0265] The pixel section 284 has a plurality of pixels 284a arranged periodically. A magnified view of one pixel 284a is shown on the right side of Figure 19B. The pixel 284a has light-emitting elements 430a, 430b, and 430c that emit light in different colors from each other. The plurality of light-emitting elements may be arranged in a stripe arrangement as shown in Figure 19B. 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.

[0266] The pixel circuit section 283 has a plurality of pixel circuits 283a arranged periodically.

[0267] 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.

[0268] 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.

[0269] The FPC 290 functions as wiring for supplying video signals or power potential, etc., to the circuit section 282 from an external source. An IC may also be mounted on the FPC 290.

[0270] The display module 280 can be configured such that one or both of the pixel circuit section 283 and the circuit section 282 are superimposed on the lower side of the pixel section 284, thereby making the aperture ratio (effective display area ratio) of the display section 281 extremely high. For example, the aperture ratio of the display section 281 can be 40% or more and less than 100%, preferably 50% or more and 95%, and more preferably 60% or more and 95%. Furthermore, it is possible to arrange the pixels 284a at an extremely high density, making the resolution of the display section 281 extremely high. For example, it is preferable that the pixels 284a in the display section 281 are arranged at a density of 2000 ppi or more, preferably 3000 ppi or more, more preferably 5000 ppi or more, and even more preferably 6000 ppi or more, with a resolution of 20000 ppi or less, or 30000 ppi or less.

[0271] Because such a display module 280 is extremely high-resolution, it can be suitably used in VR devices such as head-mounted displays, or in glasses-type AR devices. For example, even in a configuration where the display part of the display module 280 is viewed through lenses, the display module 280 has an extremely high-resolution display part 281, so even when the display part is magnified with lenses, pixels are not visible, enabling a highly immersive display. Furthermore, the display module 280 is not limited to this, and can be suitably used in electronic devices with relatively small display parts. For example, it can be suitably used in the display part of wearable electronic devices such as wristwatches.

[0272] [Display device 400C] The display device 400C shown in Figure 20 has a substrate 301, light-emitting elements 430a, 430b, 430c, a capacitor 240, and a transistor 310.

[0273] Substrate 301 corresponds to substrate 291 in Figures 19A and 19B.

[0274] 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.

[0275] Furthermore, an element isolation layer 315 is provided between two adjacent transistors 310 so as to be embedded in the substrate 301.

[0276] Furthermore, an insulating layer 261 is provided to cover the transistor 310, and a capacitance 240 is provided on the insulating layer 261.

[0277] 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.

[0278] 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.

[0279] An insulating layer 255 is provided covering the capacitance 240, and light-emitting elements 430a, 430b, 430c, etc. are provided on the insulating layer 255. A protective layer 416 is provided on the light-emitting elements 430a, 430b, 430c, 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 19A.

[0280] 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.

[0281] 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.

[0282] 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. 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.

[0283] [Display Device 400D] The display device 400D shown in Figure 21 differs from the display device 400C mainly in its transistor configuration. Note that explanations of parts similar to those of the display device 400C may be omitted.

[0284] 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.

[0285] 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.

[0286] The substrate 331 corresponds to the substrate 291 in Figures 19A and 19B. An insulating substrate or a semiconductor substrate can be used as the substrate 331.

[0287] 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.

[0288] 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.

[0289] 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.

[0290] A pair of conductive layers 325 are provided in contact with the semiconductor layer 321 and function as source electrodes and drain electrodes.

[0291] 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.

[0292] 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.

[0293] 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.

[0294] 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.

[0295] 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.

[0296] 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.

[0297] [Display Device 400E] The display device 400E shown in Figure 22 has a configuration in which a transistor 310 with a channel formed on a substrate 301 and a transistor 320 containing a metal oxide in the semiconductor layer where the channel is formed are stacked. Note that parts that are the same as those of display devices 400C and 400D may be omitted from the explanation.

[0298] 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.

[0299] 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.

[0300] 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.

[0301] 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.

[0302] This embodiment can be implemented in appropriate combination with other embodiments described herein, at least in part.

[0303] (Embodiment 4) 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.

[0304] 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).

[0305] 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.

[0306] In this specification, 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)) may be referred to as 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 facilitating improvements in brightness and reliability. Furthermore, in this specification, a light-emitting device capable of emitting white light may be referred to as a white light-emitting device. A white light-emitting device can be combined with a colored layer (for example, a color filter) to create a full-color display device.

[0307] 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.

[0308] [Light-emitting devices] Light-emitting devices can be broadly classified into single-structure and tandem-structure. 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. To obtain white light emission in a single-structure device, one should select light-emitting layers such that the light emitted by each of the two or more layers can produce white light. For example, in the case of two colors, by making the light-emitting color of the first light-emitting layer and the light-emitting color of the second light-emitting layer complementary colors, a configuration that produces white light emission as a whole can be obtained. Also, when obtaining white light emission using three or more light-emitting layers, the light-emitting device can be configured so that the light-emitting colors of the three or more layers combine to produce white light emission as a whole.

[0309] 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 unit current can be increased, and a more reliable light-emitting device can be achieved compared to a single-unit structure. To obtain white light emission in a tandem structure, the light from the light-emitting layers of multiple light-emitting units can be combined to produce white light emission. The combination of light-emitting colors that produces white light emission is the same as that for a single-unit structure. In a tandem device, it is preferable to provide an intermediate layer, such as a charge-generating layer, between the multiple light-emitting units.

[0310] When comparing white light-emitting devices with SBS structure light-emitting devices, SBS structure light-emitting devices can consume less power than white light-emitting devices. On the other hand, white light-emitting devices have a simpler manufacturing process than SBS structure light-emitting devices, resulting in lower manufacturing costs and higher manufacturing yields.

[0311] As shown in Figure 23A, 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.

[0312] The light-emitting layer 771 has at least a light-emitting substance (also called a light-emitting material).

[0313] 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.

[0314] 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 23A is referred to as a single structure.

[0315] Furthermore, Figure 23B shows a modified example of the EL layer 763 of the light-emitting device shown in Figure 23A. Specifically, the light-emitting device shown in Figure 23B has a layer 781 on the lower electrode 761, a layer 782 on the layer 781, a light-emitting layer 771 on the layer 782, a layer 791 on the light-emitting layer 771, a layer 792 on the layer 791, and an upper electrode 762 on the layer 792.

[0316] 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.

[0317] As shown in Figures 23C and 23D, a configuration in which multiple light-emitting layers (light-emitting layers 771, 772, and 773) are provided between layer 780 and layer 790 is also a variation of the single structure. Although Figures 23C and 23D show an example with three light-emitting layers, the number of light-emitting layers in a single-structure light-emitting device may be two or four or more.

[0318] Furthermore, a single-layer light-emitting device may have a buffer layer between the two light-emitting layers.

[0319] Furthermore, as shown in Figures 23E and 23F, 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.

[0320] Figures 23D and 23F show examples in which the display device has a layer 764 that overlaps with the light-emitting device. Figure 23D shows an example in which layer 764 overlaps with the light-emitting device shown in Figure 23C, and Figure 23F shows an example in which layer 764 overlaps with the light-emitting device shown in Figure 23E. In Figures 23D and 23F, 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.

[0321] As layer 764, one or both of the following can be used: a color conversion layer and / or a color filter (coloring layer).

[0322] In Figures 23C and 23D, the light-emitting layers 771, 772, and 773 may be made of light-emitting materials that emit light of the same color, or even the same light-emitting material. For example, light-emitting materials that emit blue light may be used for the light-emitting layers 771, 772, and 773. In subpixels that emit blue light, the blue light emitted by the light-emitting device can be extracted. In subpixels that emit red light and subpixels that emit green light, by providing a color conversion layer as layer 764 as shown in Figure 23D, the blue light emitted by the light-emitting device can be converted into longer wavelength light, and red or green light can be extracted. It is also preferable to use both a color conversion layer and a coloring layer as layer 764. Some of the light emitted by the light-emitting device may be transmitted directly without being converted by the color conversion layer. By extracting the light that has passed through the color conversion layer via the coloring layer, the color of light other than the desired color can be absorbed by the coloring layer, and the color purity of the light emitted by the subpixel can be increased.

[0323] Furthermore, in Figures 23C and 23D, different light-emitting materials with different emission colors may be used for each of the light-emitting layers 771, 772, and 773. White light emission can be obtained by selecting light-emitting layers that can produce white light through the emission of each of the light-emitting layers 771, 772, and 773. For example, a single-structure light-emitting device preferably has a light-emitting layer having a light-emitting material that emits blue light, and a light-emitting layer having a light-emitting material that emits visible light with a longer wavelength than blue light.

[0324] A color filter may be provided as layer 764, as shown in Figure 23D. By passing white light through the color filter, light of the desired color can be obtained.

[0325] For example, if a single-structure light-emitting device has three light-emitting layers, it is preferable that it has a light-emitting layer having a light-emitting material that emits red (R) light, a light-emitting layer having a light-emitting material that emits green (G) light, and a light-emitting layer having a light-emitting material that emits blue (B) light. The stacking order of the light-emitting layers can be R, G, B from the anode side, or R, B, G from the anode side, etc. In this case, a buffer layer may be provided between R and G or B.

[0326] Furthermore, for example, when a single-structure light-emitting device has two light-emitting layers, a configuration is preferred in which one light-emitting layer has a light-emitting material that emits blue (B) light, and the other light-emitting layer has a light-emitting material that emits yellow (Y) light. This configuration may be referred to as a BY single structure.

[0327] A light-emitting device that emits white light preferably contains two or more types of light-emitting materials. To obtain white light emission, the light-emitting materials should be selected such that the light emitted by each of the two or more materials is complementary in color. For example, by making the light-emitting color of the first light-emitting layer and the light-emitting color of the second light-emitting layer complementary in color, a light-emitting device that emits white light as a whole can be obtained. The same applies to light-emitting devices that have three or more light-emitting layers.

[0328] Furthermore, in Figures 23C and 23D, as shown in Figure 23B, layer 780 and layer 790 may each be independently constructed as a laminated structure consisting of two or more layers.

[0329] Furthermore, in Figures 23E and 23F, 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 sub-pixels 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. In the sub-pixels that emit blue light, the blue light emitted by the light-emitting device can be extracted. In addition, in the sub-pixels that emit red light and the sub-pixels that emit green light, by providing a color conversion layer as layer 764 as shown in Figure 23F, the blue light emitted by the light-emitting device can be converted into longer wavelength light, and red or green light can be extracted. Furthermore, it is preferable to use both a color conversion layer and a coloring layer as layer 764.

[0330] Furthermore, in Figures 23E and 23F, different luminescent materials with different emission colors may be used for the luminescent layer 771 and the luminescent layer 772. When the light emitted by the luminescent layer 771 and the light emitted by the luminescent layer 772 are complementary colors, white light emission is obtained. A color filter may be provided as layer 764 as shown in Figure 23F. By passing white light through the color filter, light of a desired color can be obtained.

[0331] In Figures 23E and 23F, 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.

[0332] Furthermore, while Figures 23E and 23F illustrate a light-emitting device having two light-emitting units, the device is not limited to this. A light-emitting device may have three or more light-emitting units. A configuration with two light-emitting units may be referred to as a two-stage tandem structure, and a configuration with three light-emitting units may be referred to as a three-stage tandem structure.

[0333] Furthermore, in Figures 23E and 23F, 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.

[0334] 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.

[0335] 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.

[0336] 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.

[0337] Furthermore, an example of a tandem structure light-emitting device is the configuration shown in Figures 24A to 24C.

[0338] Figure 24A shows a configuration having three light-emitting units. In Figure 24A, 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.

[0339] In Figure 24A, 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 have a configuration in which a blue (B) light-emitting material is present (a so-called B / B / B three-stage tandem structure). Note that "b / a" means that a light-emitting unit having a light-emitting material has a light-emitting material that emits light of color a, and a light-emitting unit having a light-emitting material is provided on top of that unit via a charge generation layer, where a and b represent colors.

[0340] Furthermore, in Figure 24A, some or all of the light-emitting layers 771, 772, and 773 may be made of light-emitting materials with different light-emitting colors. Examples of combinations of light-emitting colors for the light-emitting layers 771, 772, and 773 include a configuration where two are blue (B) and the remaining one is yellow (Y), and a configuration where one is red (R), another is green (G), and the remaining one is blue (B).

[0341] The light-emitting materials that each emit light of the same color are not limited to the above configuration. For example, as shown in Figure 24B, a tandem-type light-emitting device may be used in which multiple light-emitting units having multiple light-emitting layers are stacked. Figure 24B shows a configuration in which two light-emitting units (light-emitting unit 763a and light-emitting unit 763b) are connected in series via a charge-generating layer 785. Light-emitting unit 763a has layer 780a, light-emitting layer 771a, light-emitting layer 771b, light-emitting layer 771c, and layer 790a, and light-emitting unit 763b has layer 780b, light-emitting layer 772a, light-emitting layer 772b, light-emitting layer 772c, and layer 790b.

[0342] In Figure 24B, the light-emitting materials for light-emitting layers 771a, 771b, and 771c are selected so that their respective emission colors combine to produce white light, thereby configuring the light-emitting unit 763a to emit white light (W). Similarly, the light-emitting materials for light-emitting layers 772a, 772b, and 772c are selected so that their respective emission colors combine to produce white light, thereby configuring the light-emitting unit 763b to emit white light (W). In other words, the configuration shown in Figure 24B is a two-stage tandem structure of W / W. There are no particular limitations on the stacking order of the light-emitting materials. The implementer can select the optimal stacking order as appropriate. In addition, although not shown, a three-stage tandem structure of W / W / W, or a tandem structure of four or more stages, may also be used.

[0343] Furthermore, when using a tandem light-emitting device, there are two-stage tandem structures: B / Y or Y / B having a light-emitting unit that emits yellow (Y) light and a light-emitting unit that emits blue (B) light; R・G / B or B / R・G having a light-emitting unit that emits red (R) and green (G) light and a light-emitting unit that emits blue (B) light; and a light-emitting unit that emits blue (B) light, a light-emitting unit that emits yellow (Y) light, and a light-emitting unit that emits blue (B) light. Examples include a B / Y / B three-stage tandem structure having a light-emitting unit that emits blue (B) light, a light-emitting unit that emits yellow-green (YG) light, and a light-emitting unit that emits blue (B) light in that order, and a B / YG / B three-stage tandem structure having a light-emitting unit that emits blue (B) light, a light-emitting unit that emits green (G) light, and a light-emitting unit that emits blue (B) light in that order. Note that "a and b" means that one light-emitting unit has a light-emitting material that emits light a and a light-emitting material that emits light b.

[0344] Furthermore, as shown in Figure 24C, a light-emitting unit having one light-emitting layer and a light-emitting unit having multiple light-emitting layers may be combined.

[0345] Specifically, in the configuration shown in Figure 24C, a plurality of light-emitting units (light-emitting units 763a, 763b, and 763c) are connected in series via a charge generation layer 785. Furthermore, light-emitting unit 763a has a layer 780a, a light-emitting layer 771, and a layer 790a; light-emitting unit 763b has a layer 780b, a light-emitting layer 772a, a light-emitting layer 772b, a light-emitting layer 772c, and a layer 790b; and light-emitting unit 763c has a layer 780c, a light-emitting layer 773, and a layer 790c.

[0346] For example, in the configuration shown in Figure 24C, a three-stage tandem structure of B / R, G, YG / B can be applied, where light-emitting unit 763a is a light-emitting unit that emits blue (B) light, light-emitting unit 763b is a light-emitting unit that emits red (R), green (G), and yellow-green (YG) light, and light-emitting unit 763c is a light-emitting unit that emits blue (B) light.

[0347] For example, the number of layers and color order of the light-emitting unit can be, from the anode side, a two-layer structure of B and Y, a two-layer structure of B and light-emitting unit X, a three-layer structure of B, Y, B, or a three-layer structure of B, X, B. The number of layers and color order of the light-emitting layers in light-emitting unit X can be, from the anode side, a two-layer structure of R and Y, a two-layer structure of R and G, a two-layer structure of G and R, a three-layer structure of G, R, G, or a three-layer structure of R, G, R. In addition, other layers may be provided between the two light-emitting layers.

[0348] Next, we will describe materials that can be used in light-emitting devices.

[0349] 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.

[0350] 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.

[0351] 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 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 (aluminum 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.

[0352] 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 semitransmissive / 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.

[0353] 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).

[0354] The light transmittance of the transparent electrode shall be 40% or more. For example, it is preferable to use an electrode with a visible light transmittance (light with a wavelength of 400 nm or more and less than 750 nm) of 40% or more for the transparent electrode of a light-emitting device. The visible light reflectance of the semi-transparent and semi-reflective electrodes shall be 10% or more and 95% or less, preferably 30% or more and 80% or less. The visible light reflectance of the reflective electrode shall be 40% or more and 100% or less, preferably 70% or more and 100% or less. The resistivity of these electrodes shall be 1 × 10⁻⁶ −２ A value of Ωcm or less is preferable.

[0355] A light-emitting device has at least a light-emitting layer. Furthermore, a light-emitting device may have layers other than the light-emitting layer, including materials with high hole injection properties, materials with high hole transport properties, hole-blocking materials, materials with high electron transport properties, electron-blocking materials, materials with high electron injection properties, or bipolar materials (materials with high electron and hole transport properties). For example, a light-emitting device can have a configuration that includes, in addition to the light-emitting layer, one or more layers from among 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.

[0356] 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.

[0357] 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.

[0358] Examples of luminescent materials include fluorescent materials, phosphorescent materials, TADF materials, and quantum dot materials.

[0359] 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.

[0360] 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.

[0361] 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.

[0362] 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.

[0363] 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).

[0364] 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.

[0365] As acceptor materials, for example, oxides of metals belonging to groups 4 through 8 of the periodic table can be used. Specifically, these include molybdenum oxide, vanadium oxide, niobium oxide, tantalum oxide, chromium oxide, tungsten oxide, manganese oxide, and rhenium oxide. Among these, molybdenum oxide is particularly preferred because it is stable in the atmosphere, has low hygroscopicity, and is easy to handle. Organic acceptor materials containing fluorine can also be used. Furthermore, organic acceptor materials such as quinodimethane derivatives, chloranil derivatives, and hexaazatriphenylene derivatives can also be used.

[0366] 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.

[0367] The hole transport layer is a layer that transports holes injected from the anode by the hole injection layer to the light-emitting layer. The hole transport layer is a layer containing a hole-transporting material. The hole-transporting material is 1 × 10 −６ cm 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.

[0368] 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 that has electron-blocking properties can be used for the electron blocking layer.

[0369] 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.

[0370] 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, and other π-electron-deficient heteroaromatic compounds containing nitrogen-containing heteroaromatic compounds.

[0371] The hole-blocking layer is provided in contact with the light-emitting layer. The hole-blocking layer is a layer containing a material that has electron-transporting properties and is capable of blocking holes. Among the electron-transporting materials mentioned above, a material that has hole-blocking properties can be used for the hole-blocking layer.

[0372] Because hole-blocking layers possess electron-transporting properties, they can also be called electron-transporting layers. Furthermore, among electron-transporting layers, those that exhibit hole-blocking properties can also be called hole-blocking layers.

[0373] 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.

[0374] 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.

[0375] 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 ｘ Alkali metals such as cesium carbonate, alkaline earth metals, or compounds thereof can be used. The electron injection layer may also be a multilayer structure of two or more layers. For example, a multilayer structure in which lithium fluoride is used as the first layer and ytterbium is provided as the second layer can be used.

[0376] 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.

[0377] 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.

[0378] 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.

[0379] The charge generation layer preferably has a P-type layer. The P-type layer preferably contains an acceptor material, and preferably contains, for example, a hole transport material and an acceptor material applicable to the hole injection layer described above.

[0380] 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.

[0381] The electron injection buffer layer preferably contains an alkali metal or an alkaline earth metal, for example, a compound of an alkali metal or an alkaline earth metal. Specifically, the electron injection buffer layer preferably has an inorganic compound containing an alkali metal and oxygen, or an inorganic compound containing an alkaline earth metal and oxygen, and an inorganic compound containing lithium and oxygen (lithium oxide (Li ２ It is more preferable to have (O), etc. In addition, the electron injection buffer layer can suitably use materials applicable to the electron injection layer described above.

[0382] 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.

[0383] 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.

[0384] 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.

[0385] 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.

[0386] This embodiment can be implemented in appropriate combination with other embodiments described herein, at least in part.

[0387] (Embodiment 5) In this embodiment, an electronic device according to one aspect of the present invention will be described with reference to Figures 25 to 28.

[0388] 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.

[0389] 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.

[0390] 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 (Mixed Reality) devices.

[0391] 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.

[0392] 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).

[0393] 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.

[0394] Figures 25A to 25D 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 the ability to display SR (Substantial Reality) 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.

[0395] The electronic device 700A shown in Figure 25A and the electronic device 700B shown in Figure 25B 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.

[0396] 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.

[0397] 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.

[0398] 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.

[0399] 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.

[0400] Furthermore, electronic devices 700A and 700B are equipped with batteries that can be charged wirelessly, wired, or both.

[0401] 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.

[0402] 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.

[0403] 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.

[0404] The electronic device 800A shown in Figure 25C and the electronic device 800B shown in Figure 25D 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.

[0405] 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.

[0406] 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.

[0407] 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.

[0408] 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.

[0409] 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 25C 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.

[0410] 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.

[0411] 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.

[0412] 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.

[0413] 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.

[0414] 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 25A 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 25C has a function for transmitting information to the earphone 750 through its wireless communication function.

[0415] Furthermore, the electronic device may have an earphone section. The electronic device 700B shown in Figure 25B has an earphone section 727. For example, the earphone section 727 and the control unit can be connected to each other by a wire. Part of the wiring connecting the earphone section 727 and the control unit may be located inside the housing 721 or the mounting section 723.

[0416] Similarly, the electronic device 800B shown in Figure 25D has an earphone unit 827. For example, the earphone unit 827 and the control unit 824 can be connected to each other by a wire. Part of the wiring connecting the earphone unit 827 and the control unit 824 may be located inside the housing 821 or the mounting unit 823. Also, the earphone unit 827 and the mounting unit 823 may have magnets. This allows the earphone unit 827 to be fixed to the mounting unit 823 by magnetic force, which is preferable as it makes storage easier.

[0417] 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.

[0418] 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.

[0419] The electronic device 6500 shown in Figure 26A is a portable information terminal that can be used as a smartphone.

[0420] 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.

[0421] A display panel according to one embodiment of the present invention can be applied to the display unit 6502.

[0422] Figure 26B is a schematic cross-sectional view of the housing 6501 including the end on the microphone 6506 side.

[0423] 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.

[0424] 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).

[0425] 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.

[0426] 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.

[0427] Figure 26C 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.

[0428] The television device 7100 shown in Figure 26C 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.

[0429] 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.

[0430] Figure 26D 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.

[0431] Figures 26E and 26F show examples of digital signage.

[0432] The digital signage 7300 shown in Figure 26E 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.

[0433] Figure 26F 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.

[0434] 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.

[0435] 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.

[0436] Furthermore, as shown in Figures 26E and 26F, 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.

[0437] 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.

[0438] In Figures 26C to 26F, a display panel according to one embodiment of the present invention can be applied to the display unit 7000.

[0439] The electronic device shown in Figures 27A to 27G 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, detect, 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, etc.

[0440] The electronic devices shown in FIGS. 27A to 27G have various functions. For example, they can have functions such as displaying various information (still images, moving images, text images, etc.) on a display unit, a touch panel function, a function of displaying a calendar, date, or time, a function of controlling processing by various software (programs), a wireless communication function, a function of reading and processing a program or data recorded on a recording medium, and the like. Note that the functions of the electronic device are not limited to these, and it can have various functions. The electronic device may have a plurality of display units. Also, the electronic device may be provided with a camera or the like, and may have functions such as shooting a still image or a moving image and storing it in a recording medium (external or built into the camera), and displaying the shot image on the display unit.

[0441] Details of the electronic devices shown in FIGS. 27A to 27G will be described below.

[0442] FIG. 27A is a perspective view showing a portable information terminal 9101. The portable information terminal 9101 can be used, for example, as a smartphone. Note that the portable information terminal 9101 may be provided with a speaker 9003, a connection terminal 9006, a sensor 9007, etc. Also, the portable information terminal 9101 can display character and image information on its plurality of surfaces. FIG. 27A shows an example in which three icons 9050 are displayed. Also, information 9051 shown by a dashed rectangle can be displayed on another surface of the display unit 9001. Examples of the information 9051 include notifications of incoming calls such as e-mails, SNS, and phone calls, titles of e-mails or SNS, sender names, dates, times, remaining battery levels, radio wave intensities, and the like. Or, an icon 9050 or the like may be displayed at the position where the information 9051 is displayed.

[0443] FIG. 27B is a perspective view showing the portable information terminal 9102. The portable information terminal 9102 has a function of displaying information on three or more sides of the display unit 9001. Here, an example is shown in which the information 9052, the information 9053, and the information 9054 are displayed on different surfaces. For example, the user can also check the information 9053 displayed at a position where it can be observed from above the portable information terminal 9102 while the portable information terminal 9102 is stored in the breast pocket of the clothing. The user can check the display without taking the portable information terminal 9102 out of the pocket and can, for example, determine whether to receive a call or not.

[0444] FIG. 27C is a perspective view showing the tablet terminal 9103. As an example, the tablet terminal 9103 can execute various applications such as a mobile phone, an e-mail, text browsing and creation, music playback, Internet communication, and a computer game. The tablet terminal 9103 has a display unit 9001, a camera 9002, a microphone 9008, and a speaker 9003 on the front surface of the housing 9000, and an operation key 9005 as an operation button on the left side surface of the housing 9000, and a connection terminal 9006 on the bottom surface.

[0445] FIG. 27D is a perspective view showing the wristwatch-type portable information terminal 9200. The portable information terminal 9200 can be used, for example, as a smart watch (registered trademark). Further, the display surface of the display unit 9001 is provided to be curved, and display can be performed along the curved display surface. Further, the portable information terminal 9200 can also perform hands-free calling by mutually communicating with, for example, a wirelessly communicable headset. Further, the portable information terminal 9200 can also perform mutual data transmission with other information terminals and charging by means of the connection terminal 9006. Note that the charging operation may be performed by wireless power supply.

[0446] Figures 27E to 27G are perspective views showing a foldable portable information terminal 9201. Figure 27E shows the portable information terminal 9201 in an unfolded state, Figure 27G shows it in a folded state, and Figure 27F shows a perspective view of the state in between, transitioning from one of Figures 27E or 27G 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.

[0447] Figures 28A and 28B 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.

[0448] 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.

[0449] 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.

[0450] 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 28C, 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.

[0451] This embodiment can be implemented in appropriate combination with other embodiments described herein, at least in part.

[0452] HT: Processing chamber, LL: Loading chamber, RBT: Transport robot, SP: Film forming chamber, Sx: Gap, Sy: Gap, TF: Transfer chamber, UL: Carrying out chamber, EL1: Film forming chamber, EL2: Film forming chamber, E L3: Deposition chamber, EL4: Deposition chamber, EL5: Deposition chamber, EL6: Deposition chamber, EL7: Deposition chamber, EL8: Deposition chamber, EL11: Deposition chamber, EL12: Deposition chamber, EL13: Deposition chamber, EL 14: Deposition chamber, EL15: Deposition chamber, EL16: Deposition chamber, 100: Display device, 101: Substrate, 102: EL layer, 103: Upper electrode, 110: Light-emitting element, 110B: Light-emitting element, 110G: Light-emitting element, 110R: Light-emitting element, 111: Pixel electrode, 111B: Pixel electrode, 111G: Pixel electrode, 111R: Pixel electrode, 112: EL layer, 112B: EL Layer, 112G: EL layer, 112Ga: EL layer, 112R: EL layer, 112Ra: EL layer, 113: upper electrode, 113B: upper electrode, 113G: upper electrode, 113Ga: conductive layer, 113R: upper electrode, 113Ra: conductive layer, 120: partition, 120f: conductive film, 121: film deposition material, 122: film deposition material, 125: rotation axis, 131: insulating layer, 13 2: insulating layer, 133: insulating layer, 135: protective layer, 135B: protective layer, 135G: protective layer, 135R: protective layer, 136: protective layer, 141: resist mask, 141a: resist mask, 141b: resist mask, 141c: resist mask, 150: transistor, 151: semiconductor layer, 152: insulating layer, 153: conductive layer, 154: conductive layer,

Claims

1. A display device comprising: a pixel electrode, an EL layer, an upper electrode, a first insulating layer, a partition wall, and a transistor, wherein the transistor is located below the pixel electrode and connected to the pixel electrode, the first insulating layer has an end on the pixel electrode, the partition wall is located on the first insulating layer, the EL layer contains a light-emitting compound and is in contact with the upper surface of the pixel electrode and the upper surface of the first insulating layer, the upper electrode covers the upper surface and end of the EL layer and is in contact with the upper surface of the first insulating layer and the side surface of the partition wall, the partition wall has an inverse tapered shape in cross-section and is conductive, and there is a gap between the end of the first insulating layer and the partition wall.

2. A display device comprising: a pixel electrode, an EL layer, an upper electrode, a first insulating layer, a partition wall, and a transistor, wherein the transistor is located below the pixel electrode and connected to the pixel electrode, the first insulating layer has an end on the pixel electrode, the partition wall is located on the first insulating layer, the EL layer contains a light-emitting compound and is in contact with the upper surface of the pixel electrode and the upper surface of the first insulating layer, the upper electrode covers the upper surface and end of the EL layer and is in contact with the upper surface of the first insulating layer and the side surface of the partition wall, the partition wall has a shape in which the length of the upper side is longer than the length of the lower side in a cross-sectional view and is conductive, and there is a gap between the end of the first insulating layer and the partition wall.

3. A display device comprising: a pixel electrode, an EL layer, an upper electrode, a first insulating layer, a partition wall, and a transistor, wherein the transistor is located below the pixel electrode and connected to the pixel electrode, the first insulating layer has an end on the pixel electrode, the partition wall is located on the first insulating layer, the EL layer contains a light-emitting compound and is in contact with the upper surface of the pixel electrode and the upper surface of the first insulating layer, the upper electrode covers the upper surface and end of the EL layer and is in contact with the upper surface of the first insulating layer and the side surface of the partition wall, the partition wall has a hexagonal shape in cross-sectional view having a first portion having an inverse tapered shape and a second portion on the first portion, and is conductive, and there is a gap between the end of the first insulating layer and the partition wall.

4. The device comprises 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 first insulating layer, a partition wall, and a transistor, wherein the transistor is located below the first pixel electrode and connected to the first pixel electrode, the first insulating layer has ends on the first pixel electrode and the second pixel electrode, the partition wall is located on the first insulating layer, the first EL layer contains a first light-emitting compound and is in contact with the upper surface of the first pixel electrode and the upper surface of the first insulating layer, the second EL layer contains a second light-emitting compound and is in contact with the upper surface of the second pixel electrode and the upper surface of the first insulating layer, the first upper electrode covers the upper surface and ends of the first EL layer and is in contact with the upper surface of the first insulating layer and a part of the side surface of the partition wall. A display device wherein the second upper electrode covers the upper surface and edge of the second EL layer and is in contact with the upper surface of the first insulating layer and other parts of the side surface of the partition wall, the partition wall has an inverse tapered shape in cross-sectional view and is conductive, and there is a gap between the edge of the first insulating layer on the first pixel electrode and the partition wall.

5. A display device according to any one of claims 1 to 4, wherein the angle between the contact surface of the partition wall with the first insulating layer and the side surface is 95 degrees or more and 150 degrees or less.

6. A display device according to any one of claims 1 to 4, wherein the angle between the contact surface of the partition wall with the first insulating layer and the side surface is 105 degrees or more and 175 degrees or less.

7. A display device according to any one of claims 1 to 4, wherein the partition wall contains indium.

8. A display device according to any one of claims 1 to 4, wherein the transistor comprises a metal oxide in the semiconductor layer on which the channel is formed.

9. A method for manufacturing a display device, comprising: forming a first insulating layer covering a portion of a first pixel electrode and a portion of a second pixel electrode; forming a first conductive film on the first pixel electrode, the second pixel electrode, and the first insulating layer; removing a portion of the first conductive film to create a reverse tapered shape, and exposing a portion of the upper surface of the first pixel electrode and the upper surface of the first insulating layer; forming a first EL layer on the first pixel electrode and a second EL layer on the first conductive film that is physically separated from the first EL layer; forming an upper electrode covering the first EL layer and in contact with the side surface of the first conductive film; forming a protective layer covering the upper electrode; etching the second EL layer so that the end of the second EL layer is located on the first conductive film; removing another portion of the first conductive film to create a reverse tapered shape, and exposing a portion of the upper surface of the second pixel electrode and the upper surface of the first insulating layer.

10. A method for manufacturing a display device, wherein the protective layer is formed by atomic layer deposition and covers the side surface of the first conductive film, according to claim 9.

11. A method for manufacturing a display device, wherein the processing of the first conductive film is performed by a wet etching method, according to claim 9.

Images