Display device

Abstract

A display device capable of transparent display is provided. The display device includes an insulating layer continuously disposed in a first region including a first light-emitting element, a second region including a second light-emitting element, and a third region through which external light passes. The first light-emitting element includes a first pixel electrode, a first organic layer, and a common electrode. The second light-emitting element includes a second pixel electrode, a second organic layer, and a common electrode. In cross-section, the angle formed by the bottom surface and the side surface of the first organic layer and the angle formed by the bottom surface and the side surface of the second organic layer are both 60 degrees or more and 120 degrees or less. The insulating layer includes a portion overlapping the first organic layer with the common electrode, a portion overlapping the second organic layer with the common electrode, and a portion located in the third region; the insulating layer is transparent.

Description

[Technical Field]

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

[0002] Note that one embodiment of the present invention is not limited to the above-described technical field. Examples of technical fields within the scope of one embodiment of the present invention disclosed in this specification include semiconductor devices, display devices, light-emitting devices, energy storage devices, memory devices, electronic devices, lighting equipment, input devices, input / output devices, driving methods for the aforementioned devices, and manufacturing methods for the aforementioned devices. A semiconductor device refers to any device capable of operating by utilizing the characteristics of a semiconductor. [Previous Technology]

[0003] In recent years, display devices have been required to be diversified. One such requirement is a display device with a see-through function, in which the display section is light-transmitting and allows the view of objects behind it to be seen. Display devices with the aforementioned see-through function are expected to be used for applications such as windshields of vehicles, windows of buildings such as houses and high-rises, shop window glass and display cases, or head-up displays for automobiles and airplanes.

[0004] Patent document 1 discloses a display device capable of switching between normal display and perspective display.

[0005] [Patent Document 1] Japanese Patent Application Publication No. 2018-189937 [Summary of the Invention]

[0006] One objective of one embodiment of the present invention is to provide a display device capable of perspective display. Another objective of one embodiment of the present invention is to provide a display device with high resolution. Another objective of one embodiment of the present invention is to provide a display device with high aperture ratio. Another objective of one embodiment of the present invention is to provide a display device with high brightness. Another objective of one embodiment of the present invention is to provide a display device with high reliability.

[0007] One objective of one embodiment of the present invention is to provide a display device having a novel structure. Another objective of one embodiment of the present invention is to provide a method for manufacturing the aforementioned display device with high yield. Yet another objective of one embodiment of the present invention is to at least improve upon at least one of the problems of the prior art.

[0008] Note that the description of these objectives does not preclude the existence of other objectives. Note that one embodiment of the present invention does not need to achieve all of the above objectives. In addition, objectives other than those described above can be derived from the description in the specification, drawings, claims, etc.

[0009] One embodiment of the present invention is a display device comprising: a first region including a first light-emitting element; a second region including a second light-emitting element; and a third region through which external light is transmitted. Additionally, the display device further includes an insulating layer continuously disposed in the first region, the second region, and the third region. The first light-emitting element includes a first pixel electrode, a first organic layer, and a common electrode. The second light-emitting element includes a second pixel electrode, a second organic layer, and a common electrode. The first pixel electrode and the second pixel electrode are disposed side-by-side. The first organic layer is disposed on the first pixel electrode. The second organic layer is disposed on the second pixel electrode. In cross-section, the angle formed by the bottom surface and the side surface of the first organic layer and the angle formed by the bottom surface and the side surface of the second organic layer are both 60 degrees or more and 120 degrees or less. The insulating layer includes a portion overlapping the first organic layer with the common electrode, a portion overlapping the second organic layer with the common electrode, and a portion located in the third region; and the insulating layer is light-transmitting.

[0010] In addition, in the above-mentioned display device, it is preferable that the first organic layer and the second organic layer contain compounds with different light-emitting properties.

[0011] Alternatively, in the above-described display device, preferably, the first organic layer and the second organic layer contain compounds with the same luminescence properties, and a color layer or color conversion layer is provided at the position overlapping with the first light-emitting element.

[0012] In addition, in the above-described display device, it is preferable that the common electrode is light-transmitting and that the common electrode includes a portion located in the third region.

[0013] Alternatively, in the above-described display device, it is preferable that the common electrode is both transparent and reflective, and that the common electrode has an opening that overlaps with the third region.

[0014] Furthermore, in any of the above-mentioned display devices, it is preferable to further include a second insulating layer covering the ends of the first pixel electrode and the second pixel electrode. In this case, it is preferable that the second insulating layer has a portion overlapping with the third region.

[0015] Alternatively, in any of the above display devices, it is preferable to further include a second insulating layer covering the ends of the first pixel electrode and the second pixel electrode. In this case, it is preferable that the second insulating layer has an opening in the portion overlapping with the third region.

[0016] Furthermore, in any of the above-mentioned display devices, it is preferable to further include a third insulating layer. The third insulating layer comprises an organic resin and includes a first portion located between the first light-emitting element and the second light-emitting element. Preferably, the first organic layer and the second organic layer sandwich the first portion of the third insulating layer, and the third insulating layer has a second portion overlapping the third region.

[0017] Alternatively, in any of the above-mentioned display devices, the third insulating layer comprises an organic resin and includes a first portion located between the first light-emitting element and the second light-emitting element. Furthermore, preferably, the first organic layer and the second organic layer sandwiching the first portion of the third insulating layer are opposed to each other, and the third insulating layer has an opening in the portion overlapping with the third region.

[0018] Furthermore, in any of the above-mentioned display devices, a fourth insulating layer is preferably also included. Preferably, the fourth insulating layer comprises an inorganic insulating film and includes a third portion located between the first light-emitting element and the second light-emitting element, and is disposed along the side and bottom surfaces of the third insulating layer. Additionally, it is preferable that the side surfaces of the first organic layer and the second organic layer respectively contact the fourth insulating layer.

[0019] In addition, in the above-mentioned display device, it is preferable that the side surface of the first pixel electrode and the side surface of the second pixel electrode are in contact with the fourth insulating layer.

[0020] Furthermore, in any of the above-mentioned display devices, it is preferable that the first portion of the third insulating layer includes a portion with a convex top surface. Alternatively, it is preferable that the first portion of the third insulating layer includes a portion with a concave top surface.

[0021] According to one embodiment of the present invention, a display device capable of perspective display can be provided. According to one embodiment of the present invention, a display device with high resolution can be provided. Furthermore, according to one embodiment of the present invention, a display device with high aperture ratio can be provided. Furthermore, according to one embodiment of the present invention, a display device with high brightness can be provided. Furthermore, according to one embodiment of the present invention, a display device with high reliability can be provided.

[0022] According to one embodiment of the present invention, a display device having a novel structure can be provided. Furthermore, according to another embodiment of the present invention, a method for manufacturing the above-described display device with high yield can be provided. According to one embodiment of the present invention, at least one of the problems of the prior art can be improved.

[0023] Note that the description of these effects does not preclude the existence of other effects. Note that one embodiment of the present invention does not need to have all the above-described effects. In addition, effects other than those described above can be derived from the description in the specification, drawings, claims, etc.

Implementation Method

[0025] Hereinafter, embodiments will be described with reference to the drawings. However, those skilled in the art will readily understand that embodiments can be implemented in many different forms, and their manner and details can be varied in various ways without departing from the spirit and scope of the present invention. Therefore, the present invention should not be construed as being limited to the contents described in the embodiments shown below.

[0026] Note that in the structure of the invention described below, the same element symbols are used in common across different figures to represent the same parts or parts having the same function, and repeated descriptions are omitted. In addition, when representing parts having the same function, the same shading lines are sometimes used without additional element symbols.

[0027] Note that in the various figures described in this specification, the size of each component, the thickness of a layer, and the area are sometimes exaggerated for clarity. Therefore, the present invention is not limited to the dimensions shown in the figures.

[0028] The ordinal numbers such as “first” and “second” used in this specification are appended to avoid confusion of components, and are not intended to limit the number of components.

[0029] In this specification and the like, the terms "film" and "layer" may be interchanged. For example, "conductive layer" may sometimes be replaced with "conductive film". In addition, for example, "insulating layer" may sometimes be replaced with "insulating film".

[0030] Note that in this specification, the EL layer refers to a layer disposed between a pair of electrodes of a light-emitting element and including at least a light-emitting material (also called a light-emitting layer) or a stack including a light-emitting layer.

[0031] In this specification and the like, a display panel in one embodiment of a display device refers to a panel capable of displaying (outputting) images, etc., on a display surface. Therefore, a display panel is one embodiment of an output device.

[0032] In addition, in this specification, the structure on which connectors such as FPC (Flexible Printed Circuit) or TCP (Tape Carrier Package) are mounted on the substrate of the display panel, or the structure on which ICs are directly mounted on the substrate in the form of COG (Chip On Glass) is referred to as a display panel module or display module, or simply as a display panel, etc.

[0033] Embodiment 1 In this embodiment, an example of the structure of a display device according to an embodiment of the present invention will be described.

[0034] One embodiment of the present invention is a display device in which light-emitting elements emitting visible light are arranged in a matrix. An image can be displayed on one side of the display surface of the display device using multiple light-emitting elements. Furthermore, the display device, for example, has a transmission region between two adjacent light-emitting elements. The transmission region is the area through which visible light passes. In the transmission region, external light incident from the back side of the display device passes through, thereby allowing the user to see, overlay, the image displayed using the light-emitting elements and the transmitted image displayed by the external light passing through the transmission region. Thus, the display device can perform perspective display.

[0035] Alternatively, a structure in which the light-emitting element itself transmits visible light can be adopted. More specifically, both electrodes constituting the light-emitting element can be made to have a light-transmitting structure. This improves the transmittance of the display device during transparent display.

[0036] In addition, the display device includes at least two light-emitting elements with different emitting colors. Each light-emitting element includes a pair of electrodes and an EL layer (also called an organic layer) between the pair of electrodes. The light-emitting element is preferably an organic EL element (organic electric field light-emitting element). Two or more light-emitting elements emitting different colors each include an EL layer containing different materials. For example, a full-color display device can be realized by including three light-emitting elements that emit red (R), green (G), or blue (B) light respectively.

[0037] Here, it is known that when a portion or all of an EL layer is formed between light-emitting elements of different colors, it is formed by vapor deposition using a shadow mask such as a fine metal mask (hereinafter also referred to as FMM). However, this method does not easily achieve high resolution and high aperture ratio in the display device because the shape and position of the island-shaped organic film differ from the design due to various influences such as the accuracy of the FMM, the misalignment between the FMM and the substrate, the deflection of the FMM, and the enlargement of the outline of the deposited film caused by vapor scattering. Therefore, measures have been taken to improve the resolution (also known as pixel density) by adopting special pixel arrangement methods such as Pentile arrangement.

[0038] In one embodiment of the present invention, the EL layer can be processed into a micro-pattern without using a shadow mask such as a metal mask. This allows for the realization of a display device with high resolution and high aperture ratio, which has been difficult to achieve until now. Furthermore, since the EL layer can be manufactured separately, the display device can display very vivid and high-contrast high-quality images.

[0039] For example, in the method of forming a metal mask, it is difficult to set the spacing between EL layers of different luminous colors to be less than 10 μm. However, according to the above method, this spacing can be reduced to less than 3 μm, less than 2 μm, or less than 1 μm. For example, by using an LSI exposure apparatus, this distance can be reduced to less than 500 nm, less than 200 nm, less than 100 nm, or even less than 50 nm. As described above, one of the features of an embodiment of the present invention can be said to be that the distance between two adjacent light-emitting elements or the distance between two EL layers is extremely small. As a result, the area of ​​non-light-emitting regions that may exist between two light-emitting elements can be significantly reduced, and the aperture ratio can be close to 100%. For example, aperture ratios of 50% or more, 60% or more, 70% or more, 80% or more, or even 90% or more and less than 100% can also be achieved.

[0040] Organic films formed using FMM are mostly films with very small cone angles (e.g., greater than 0 degrees and less than 30 degrees) that become thinner towards the end. Therefore, the side surfaces and top surfaces of organic films formed using FMM are continuously connected, making it difficult to clearly identify the side surfaces. On the other hand, one embodiment of the present invention includes an EL layer that is not processed using FMM, thus having clearly defined side surfaces. In particular, in one embodiment of the present invention, it is preferable that the portion having the EL layer has a cone angle of 30 degrees or more and 120 degrees or less, and more preferably a portion having a cone angle of 60 degrees or more and 120 degrees or less.

[0041] Note that in this specification, etc., a tapered end of an object means that the angle between the side surface (the surface to be formed) and the bottom surface (the surface to be formed) in the region of its end is greater than 0 degrees and less than 90 degrees, and the cross-sectional shape has a thickness that increases continuously from the end. In addition, the tapered angle refers to the angle between the bottom surface (the surface to be formed) and the side surface (the surface to be formed) of the end of the object.

[0042] As described above, compared with the case using FMM, one embodiment of the present invention can perform high-precision processing on the EL layer, thereby also forming the transmittance region disposed between the light-emitting elements with high precision. In addition, even in high-definition display devices, a structure in which the transmittance region is not provided with an EL layer can be adopted, thereby increasing the transmittance of the transmittance region and thus improving the visibility of the background, which is preferred.

[0043] Furthermore, to insulate the two adjacent EL layers, it is preferable to provide an insulating layer between the two EL layers. In this case, it is preferable to fill the gap between the two adjacent EL layers between the two adjacent light-emitting elements with an insulating layer containing an organic resin. Alternatively, it is preferable to provide an insulating layer including an inorganic insulating film in such a way that it contacts the sides of the two adjacent EL layers respectively. Alternatively, a structure combining the above-mentioned insulating layer containing an organic resin and the above-mentioned insulating layer including an inorganic insulating film may also be used. By providing an insulating layer between the two adjacent EL layers to completely insulate them, the leakage current between the two light-emitting elements can be effectively reduced, thereby enabling a display device with high contrast.

[0044] Alternatively, the display device may employ a structure that combines a white-emitting light-emitting element with a color layer (color filter) for color display. Alternatively, it may employ a structure that combines a blue-emitting light-emitting element with a color conversion layer for color display. In this case, by placing the color layer or color conversion layer at a position overlapping with the light-emitting element, light from the light-emitting element can pass through to obtain the desired color of light. Furthermore, since the display device can use light-emitting elements of the same color, the EL layer of each light-emitting element can employ a structure including the same luminescent material (luminescent compound). In this case, by employing a structure where the EL layer is disconnected between two adjacent light-emitting elements without utilizing the FMM (Foil Model), leakage current between light-emitting elements through the EL layer can be suppressed, thereby minimizing the distance between adjacent light-emitting elements. Therefore, compared to a structure that does not disconnect the EL layer, higher resolution and higher aperture ratio can be achieved.

[0045] The following describes a more specific structural example with reference to the diagram.

[0046] [Structural Example 1] Figure 1A shows an example of the cross-sectional structure of a display device.

[0047] The display device 10 includes a functional layer 45, an insulating layer 81, a light-emitting element 90R, a light-emitting element 90G, a light-emitting element 90B, etc., between the substrate 11 and the substrate 21. Here, one side of the substrate 21 corresponds to the display surface side of the display device 10.

[0048] A transparent area 40 is provided between two adjacent light-emitting elements 90.

[0049] Note that when describing common aspects of light-emitting elements 90R, 90G, 90B, etc., the letters R, G, B, etc., used to distinguish them are omitted, and they are described only as light-emitting elements 90, etc. The same applies to organic layers 92R, 92G, 92B, etc.

[0050] The light-emitting element 90R includes a conductive layer 91, a conductive layer 93, and an organic layer 92R sandwiched between the conductive layers 91 and 93. The organic layer 92R is a layer containing at least a luminescent material. Similarly, the light-emitting element 90G includes an organic layer 92G, and the light-emitting element 90B includes an organic layer 92B. The conductive layer 91 is disposed in each pixel (each sub-pixel) and serves as a pixel electrode. The conductive layer 93 is continuously disposed in multiple pixels. The conductive layer 93 is electrically connected to wiring supplied with a constant potential in an area not shown, serving as a common electrode.

[0051] Conductive layer 91 reflects visible light, while conductive layer 93 transmits visible light. Therefore, the light-emitting element 90R, etc., is a top-emitting (top-surface-emitting) light-emitting element that emits light from one side of the substrate 21 by applying a voltage between conductive layer 91 and conductive layer 93. Similarly, light-emitting element 90G emits light 20G, and light-emitting element 90B emits light 20B.

[0052] The functional layer 45 is a layer that includes circuitry for driving the light-emitting element 90R, etc. For example, the functional layer 45 includes a pixel circuitry composed of transistors, capacitors, wiring, electrodes, etc.

[0053] The transistor in the functional layer 45 includes a gate electrode layer, a semiconductor layer, a source electrode layer, a drain electrode layer, etc. Preferably, one or more layers constituting the transistor are transparent to visible light. More preferably, all of them are transparent. Thus, a portion of the region including the transistor can be used as part of the transparent region 40.

[0054] Furthermore, it is preferable that the capacitors, wiring, electrodes, etc. in the functional layer 45 also have light transmittance. This increases the area of ​​the transmittance region, thereby improving the visibility of the transparent display.

[0055] Furthermore, the wiring connected to the multiple functional layers 45 can be made of a non-transparent conductive material such as a metal with low resistance. This reduces the wiring resistance. Alternatively, the wiring can also be made of a transparent conductive material. This allows the portion where the wiring is provided to be used as a transparent area.

[0056] An insulating layer 81 is provided between the functional layer 45 and the conductive layer 91. The conductive layer 91 and the functional layer 45 are electrically connected through an opening in the insulating layer 81. Thus, the functional layer 45 is electrically connected to the light-emitting element 90.

[0057] An adhesive layer 89 is included between the substrate 21 and the conductive layer 93. It can be said that the substrate 21 and the substrate 11 are bonded together by the adhesive layer 89. The adhesive layer 89 also serves as a sealing layer for sealing the light-emitting element 90.

[0058] An insulating layer 81, an insulating layer 84, an adhesive layer 89, etc., are provided in the transparent area 40. The insulating layer 84 is provided between two adjacent organic layers 92. The insulating layer 84 is provided in a manner that fills the gap between the two adjacent organic layers 92. In addition, the two adjacent organic layers 92 are provided in a manner that the insulating layer 84 is sandwiched between their sides.

[0059] In Figure 1A, the insulating layer 84 is disposed between two adjacent light-emitting elements 90 in such a way as to fill the gap between the conductive layers 91 that serve as pixel electrodes. The two adjacent conductive layers 91 are disposed facing each other with the insulating layer 84 sandwiched between their sides.

[0060] The insulating layer 84 can be made of either inorganic or organic insulating material. Preferably, it is an inorganic insulating material with low permeability to water and oxygen (it has barrier properties). In this case, it is preferable to arrange the insulating layer 84 containing the inorganic insulating material in a manner that contacts the side of the organic layer. Alternatively, the insulating layer 84 containing the inorganic insulating material can also be a laminated film consisting of two or more layers of inorganic insulating film. Furthermore, when using an organic insulating material, especially an organic resin, the flatness of the top surface can be improved, thereby improving the step coverage of the film formed on the insulating layer 84. The insulating layer 84 can also be made of both an insulating film containing inorganic insulating material and an insulating film containing organic insulating material.

[0061] Various optical components can be disposed on the outer side of the substrate 21. Examples of optical components include polarizing plates, phase retardation plates, light diffusion layers (diffusion films, etc.), anti-reflection layers, and condensing films. Additionally, an antistatic film to suppress dust adhesion, a waterproof film to prevent dirt adhesion, and a hard coating to prevent damage during use can also be disposed on the outer side of the substrate 21. Furthermore, a touch sensor can be disposed between the substrate 21 and the substrate 11 or on the outer side of the substrate 21. Therefore, a structure including the display device 10 and the touch sensor can be used as a touch panel.

[0062] Figure 1A shows light 20R emitted by light-emitting element 90R, light 20G emitted by light-emitting element 90G, light 20B emitted by light-emitting element 90B, and light 20t transmitted through transmission area 40. The user can see the view behind the display device 10 (through image) through transmission area 40. Furthermore, the user can see the images displayed by each light-emitting element 90 superimposed on the through image of the display device 10. Thus, AR (Augmented Reality) display is possible.

[0063] FIG1B shows an example of using a conductive layer 91t that transmits visible light as a pixel electrode. In this case, the light-emitting element 90R, etc., is a double-sided emitting (double-sided emission type) light-emitting element that emits light to both the substrate 21 side and the substrate 11 side.

[0064] Furthermore, by using a film that transmits visible light as part of the layer constituting the functional layer 45, a portion of the area where the functional layer 45 overlaps with the conductive layer 91t can transmit light 20t. Therefore, as shown in FIG1B, the user can see the transmitted image displayed by the light 20t transmitted through the transmitted area 40 and the light 20t transmitted through the light-emitting element 90R, etc.

[0065] Note that although examples are shown here of light-emitting elements 90R, 90G, and 90B comprising organic layers 92R, 92G, and 92B respectively containing different luminescent materials (luminescent compounds), structures comprising organic layers containing the same luminescent material may also be used. For example, a luminescent material that emits white light may be used for all light-emitting elements, or a luminescent material that emits red, green, or blue light may be used. The detailed structure of the light-emitting elements will be described in Embodiment 3.

[0066] For example, the display device 10 may also employ a structure that combines a light-emitting element that emits white light with a color layer (color filter) for color display. Alternatively, it may employ a structure that combines a light-emitting element that emits blue light with a color conversion layer for color display. In this case, by placing the color layer or color conversion layer at a position overlapping with the light-emitting element, light from the light-emitting element can pass through to obtain the desired color of light. Furthermore, since the display device can use light-emitting elements of the same color, the EL layer of each light-emitting element can employ a structure that includes the same luminescent material (luminescent compound). In this case, by employing a structure that disconnects the EL layer between two adjacent light-emitting elements without utilizing the FMM, leakage current between light-emitting elements through the EL layer can be suppressed, thereby minimizing the distance between adjacent light-emitting elements. Therefore, compared to a structure that does not disconnect the EL layer, higher resolution and higher aperture ratio can be achieved.

[0067] [Example of Pixel Arrangement Method] An example of a pixel arrangement method will be explained below. Arrows indicating intersecting X and Y directions are shown in the following diagrams as examples. The X direction will sometimes be referred to as the row direction, and the Y direction as the column direction. Additionally, in each diagram, a square representing the arrangement period is shown with a dashed line. This square corresponds to the area of ​​one pixel, but is not limited to it.

[0068] Figure 2A shows an example of the stripe arrangement. Light-emitting elements 90R, 90G and 90B are arranged sequentially in the X direction. The same light-emitting elements are arranged in the Y direction.

[0069] In Figure 2A, the area surrounded by solid lines is the light-emitting area. Additionally, the area outside the light-emitting area (the area with the shaded pattern) includes the transparent area 40. Note that areas outside the light-emitting area containing non-transparent components such as wiring and electrodes are non-transparent areas, which are not explicitly shown here.

[0070] Figure 2B is an example of increasing the area of ​​the transmittance region 40 by reducing the width of each light-emitting element in the Y direction in Figure 2A.

[0071] Figure 2C is an example of arranging the even-numbered and odd-numbered columns in Figure 2A in a staggered half-cycle arrangement in the Y direction. In addition, Figure 2D is an example of increasing the area of ​​the transmittance region 40 by reducing the width of each light-emitting element in the Y direction in Figure 2C.

[0072] Figure 2E shows an example of an S-striped arrangement. Light-emitting elements 90B are arranged in the Y direction, and light-emitting elements 90R and 90G are arranged alternately in the Y direction. Additionally, Figure 2F shows an example of increasing the area of ​​the transmittance region 40 by reducing the area of ​​light-emitting elements 90R and 90G in Figure 2E.

[0073] Figure 3A shows an example of an arrangement method that can utilize two types of pixels for virtual high-definition, namely, the so-called Pentile arrangement. In Figure 3A, pixels with light-emitting elements 90R and 90G and pixels with light-emitting elements 90B and 90G are arranged alternately in the X and Y directions.

[0074] Figure 3B shows an arrangement of light-emitting elements of the same color arranged diagonally. When any 2×2 light-emitting elements are selected, there must be two light-emitting elements of the same color and three light-emitting elements of different colors.

[0075] Figure 3C shows an example where a pixel contains a light-emitting element 90R, a light-emitting element 90B, and two light-emitting elements 90G. In this case, one of the light-emitting elements 90R and 90B is alternately arranged with the light-emitting element 90G in both the X and Y directions. Figure 3D is an example of removing one of the light-emitting elements 90G in Figure 3C to increase the area of ​​the transmittance region 40.

[0076] Figures 3E and 3F show examples of arranging odd-numbered rows and even-numbered rows with a half-cycle offset in the X-direction. Furthermore, the light-emitting elements are arranged with approximately equal intervals. In Figure 3E, the light-emitting elements are hexagonal, and in Figure 3F, they are elliptical. In the structures shown in Figures 3E and 3F, for example, when a light-emitting element is placed at the vertex of an equilateral triangle—that is, when the so-called densest arrangement is used—the pixel spacing in the X and Y directions is inconsistent, which may lead to image distortion. Therefore, it is preferable to use a structure where a light-emitting element is placed at the vertex of an isosceles triangle instead of an equilateral triangle.

[0077] [Structural Example 2] The following describes a more specific structural example with reference to the diagram.

[0078] Figure 4A shows a top view of the display device 100. The display device 100 includes a plurality of red light-emitting elements 90R, a plurality of green light-emitting elements 90G, and a plurality of blue light-emitting elements 90B. In Figure 4A, the symbols R, G, and B are marked in the light-emitting area of ​​each light-emitting element to facilitate differentiation.

[0079] Light-emitting elements 90R, 90G, and 90B are arranged in a matrix. Figure 1A shows light-emitting elements of the same color arranged in one direction (the long side direction of the light-emitting elements, i.e., the Y direction), i.e., a stripe arrangement. Note that the arrangement of light-emitting elements is not limited to this; other arrangements such as S-stripes, Delta, Bayer, and zigzag arrangements can also be used, as well as Pentile and Diamond arrangements.

[0080] Light-emitting elements 90R, 90G, and 90B are arranged in the X direction. In addition, light-emitting elements of the same color are arranged in the Y direction, which intersects the X direction.

[0081] Furthermore, the display device 100 includes a transmittance region 40. Here, similar to FIG. 2A, the region where no light-emitting elements are disposed is referred to as the transmittance region 40. In FIG. 4A, the spacing between light-emitting elements 90B and 90G is wider than that of the others. As a result, the area of ​​the transmittance region 40 can be larger, thereby improving the transmittance of the display device 100. Note that a structure with a wide spacing between light-emitting elements 90B and 90G is adopted here, but it is not limited to this; the spacing between any two adjacent light-emitting elements can be wider, or the light-emitting elements can be arranged at equal intervals.

[0082] As light-emitting elements 90R, 90G, and 90B, it is preferable to use EL elements such as OLED (Organic Light Emitting Diode) or QLED (Quantum-dot Light Emitting Diode). Examples of light-emitting materials contained in EL elements include fluorescent materials, phosphorescent materials, and materials that exhibit thermally activated delayed fluorescence (TADF) materials. In addition to organic compounds, inorganic compounds (quantum dot materials, etc.) can also be used as light-emitting materials in EL elements.

[0083] Note that, although an example in which the display device includes light-emitting elements of three colors, i.e., a light-emitting element 90R, a light-emitting element 90G, and a light-emitting element 90B, is shown here, it is not limited thereto, and light-emitting elements of four or more colors may also be included. For example, a structure including light-emitting elements of red (R), green (G), blue (B), yellow (Y), and white (W) may also be adopted. Alternatively, a structure including light-emitting elements of three colors, i.e., cyan (C), magenta (M), and yellow (Y), may also be adopted.

[0084] In addition, FIG. 4A shows a connection electrode 111C electrically connected to a common electrode 113. The connection electrode 111C is supplied with a potential (e.g., an anode potential or a cathode potential) to be supplied to the common electrode 113. The connection electrode 111C is provided outside a display area in which the light-emitting elements 90R and the like are arranged. In addition, in FIG. 4A, the common electrode 113 is indicated by a dashed line.

[0085] The connection electrode 111C may be provided along the outer periphery of the display area. For example, it may be provided along one side of the outer periphery of the display area, or may be provided across two or more sides of the outer periphery of the display area. That is, when the top surface shape of the display area is square, the top surface shape of the connection electrode 111C may be strip-shaped, L-shaped, "冂" - shaped (square bracket-shaped), or quadrilateral.

[0086] FIG. 4B is a schematic cross-sectional view corresponding to the dashed lines A1 - A2 and C1 - C2 in FIG. 1A.

[0087] FIG. 4B shows a cross-section of a part of the light-emitting element 90R, the light-emitting element 90G, a transmissive area 40, and the light-emitting element 90B. The light-emitting element 90R includes a pixel electrode 111, an organic layer 112R, an organic layer 114, and a common electrode 113. The light-emitting element 90G includes a pixel electrode 111, an organic layer 112G, an organic layer 114, and a common electrode 113. The light-emitting element 90B includes a pixel electrode 111, an organic layer 112B, an organic layer 114, and a common electrode 113. The light-emitting element 90R, the light-emitting element 90G, and the light-emitting element 90B share the organic layer 114 and the common electrode 113. The organic layer 114 may also be referred to as a common layer.

[0088] The organic layer 112R in the light-emitting element 90R contains at least a light-emitting organic compound that emits red light. The organic layer 112G in the light-emitting element 90G contains at least a light-emitting organic compound that emits green light. The organic layer 112B in the light-emitting element 90B includes at least a light-emitting organic compound that emits blue light. The organic layer 112R, the organic layer 112G, and the organic layer 112B may also be referred to as EL layers.

[0089] In addition to the layer containing the luminescent organic compound (luminescent layer), organic layers 112R, 112G, and 112B may also include one or more of an electron injection layer, an electron transport layer, a hole injection layer, and a hole transport layer. Organic layer 114 may have a structure that does not include a luminescent layer. For example, organic layer 114 may include one or more of an electron injection layer, an electron transport layer, a hole injection layer, and a hole transport layer.

[0090] Here, the uppermost layer in the stacked structure of organic layers 112R, 112G, and 112B, that is, the layer in contact with organic layer 114, is preferably a layer other than the light-emitting layer. For example, it is preferable to use a structure in which an electron injection layer, electron transport layer, hole injection layer, hole transport layer, or other layers are provided over the light-emitting layer and the layer is in contact with organic layer 114. In this way, when manufacturing each light-emitting element, the top surface of the light-emitting layer can be protected by other layers, thereby improving the reliability of the light-emitting element.

[0091] Pixel electrodes 111 are respectively disposed in each light-emitting element. Furthermore, the common electrode 113 and the organic layer 114 are a single layer shared by all light-emitting elements. Either the pixel electrode or the common electrode 113 uses a conductive film that is transparent to visible light, while the other uses a reflective conductive film. By making each pixel electrode transparent and the common electrode 113 reflective, a bottom-emitting (bottom-emitting structure) display device can be realized. Conversely, by making each pixel electrode reflective and the common electrode 113 transparent, a top-emitting (top-emitting structure) display device can be realized. Furthermore, by making both the pixel electrode and the common electrode 113 transparent, a double-sided emitting (double-sided emitting structure) display device can be realized.

[0092] An insulating layer 131 is provided at the end of the pixel electrode 111. The end of the insulating layer 131 is preferably tapered. Note that, in this specification, a tapered end of an object means that in the region at the end, the angle between the surface of the object and the surface to be formed is greater than 0 degrees and less than 90 degrees, and the cross-sectional shape has a thickness that continuously increases from the end.

[0093] In addition, by using an organic resin in the insulating layer 131, its surface can have a smooth curve. Therefore, the coverage of the film formed on the insulating layer 131 can be improved.

[0094] As materials that can be used for insulating layer 131, acrylic resin, polyimide resin, epoxy resin, polyimide resin, polyimide resin, silicone resin, benzocyclobutene resin, phenolic resin and precursors of these resins can be used, for example.

[0095] Alternatively, the insulating layer 131 may also be made of an inorganic insulating material. Materials suitable for the insulating layer 131 may include oxides or nitrides such as silicon oxide, silicon oxynitride, silicon oxynitride, silicon nitride, aluminum oxide, aluminum oxynitride, and hafnium oxide. Additionally, yttrium oxide, zirconium oxide, gallium oxide, tantalum oxide, magnesium oxide, lanthanum oxide, cerium oxide, and neodymium oxide may also be used.

[0096] As shown in FIG4B, a gap is provided between two organic layers between light-emitting elements with different emission colors. Preferably, organic layers 112R, 112G, and 112B are arranged in a manner that prevents them from contacting each other. This effectively prevents unintentional light emission caused by current flowing through adjacent organic layers. Consequently, contrast is improved, enabling the realization of a display device with high display quality.

[0097] Preferably, the cone angles of organic layers 112R, 112G, and 112B are 30 degrees or more. Preferably, the angle between the side surface (surface) and the bottom surface (formed surface) of the ends of organic layers 112R, 112G, and 112B is 30 degrees or more and 120 degrees or less, more preferably 45 degrees or more and 120 degrees or less, and even more preferably 60 degrees or more and 120 degrees. Alternatively, preferably, the cone angles of organic layers 112R, 112G, and 112B are 90 degrees or more (e.g., 80 degrees or more and 100 degrees or less).

[0098] A protective layer 121 is provided on the common electrode 113 to cover the light-emitting elements 90R, 90G, and 90B. The protective layer 121 has the function of preventing water and other impurities from diffusing from above to each light-emitting element.

[0099] The protective layer 121 may, for example, have a single-layer structure or a multilayer structure comprising at least an inorganic insulating film. Examples of inorganic insulating films include oxide films or nitride films such as silicon oxide films, silicon oxynitride films, silicon oxynitride films, silicon nitride films, aluminum oxide films, aluminum oxynitride films, and hafnium oxide films. Alternatively, semiconductor materials such as indium gallium oxide and indium gallium zinc oxide may be used as the protective layer 121.

[0100] Alternatively, a laminated film of inorganic and organic insulating films can be used as the protective layer 121. For example, it is preferable to sandwich an organic insulating film between a pair of inorganic insulating films. Furthermore, the organic insulating film is preferably used as a planarization film. Therefore, the top surface of the organic insulating film can be flattened, thus improving the coverage of the inorganic insulating film thereon and thereby enhancing its barrier properties. Additionally, since the top surface of the protective layer 121 is flattened, the influence of the uneven shape of the underlying structure can be reduced when a structure (e.g., a color filter, electrodes of a touch sensor, or a lens array, etc.) is placed above the protective layer 121, which is preferable.

[0101] In the connecting portion 130, a common electrode 113 is provided on the connecting electrode 111C and in contact with it, and a protective layer 121 is provided covering the common electrode 113. In addition, an insulating layer 131 is provided at the end covering the connecting electrode 111C.

[0102] In the structure shown in FIG4B, an insulating layer 131, an organic layer 114, a common electrode 113, and a protective layer 121 are provided in the transparent region 40. The layers provided in the transparent region 40 can be made of light-transmitting materials. Thus, light 20t can pass through the display device 100 in the transparent region 40.

[0103] The following describes a structural example of a display device that differs from the structure in part of Figure 4B.

[0104] FIG. 5A shows an example where the organic layer 114, the common electrode 113, and the protective layer 121 are not provided in the transmission region 40. This structure can improve the transmittance of the transmission region. In particular, when the common electrode 113 uses a membrane with both permeability and reflectivity and is located in the transmission region 40, the transmittance decreases. Therefore, as shown in FIG. 5A, it is preferable to provide an opening for the common electrode 113 in the transmission region 40.

[0105] The organic layer 114, the common electrode 113, and the protective layer 121 have openings in the transmission region 40. Furthermore, a protective layer 122 is provided covering the top and side surfaces of the protective layer 121, the side surface of the common electrode 113, and the side surface of the organic layer 114. The protective layer 122 functions to prevent impurities such as water from diffusing from the side surfaces of the common electrode 113 and the organic layer 114 to the light-emitting element 90G or the light-emitting element 90B.

[0106] The structure shown in FIG5A can be manufactured, for example, by the following method. A photoresist mask is formed on the protective layer 121, and the photoresist mask is removed after etching a portion of the protective layer 121, the common electrode 113 and the organic layer 114, and then the protective layer 122 is formed.

[0107] The examples shown in Figures 5B, 5C and 5D are examples of providing an opening in the insulating layer 131 shown in Figure 5A that overlaps with the transparent area 40.

[0108] Figure 5B shows an example where the side surface of the insulating layer 131 is substantially consistent with the side surface of the organic layer 114, the common electrode 113, and the protective layer 121, respectively. For example, the protective layer 121, the common electrode 113, the organic layer 114, and the insulating layer 131 can be manufactured using the same photoresist mask.

[0109] Figure 5C shows an example in which the ends of the organic layer 114, the common electrode 113, and the protective layer 121 are processed to overlap with the insulating layer 131.

[0110] Figure 5D shows an example where the organic layer 114, the common electrode 113 and the protective layer 121 are processed to extend beyond the end of the insulating layer 131.

[0111] Figures 6A to 8F show examples without the insulating layer 131.

[0112] Figures 6A to 6F show examples where the side of the pixel electrode 111 is substantially aligned with the side of the organic layer 112R, organic layer 112G, or organic layer 112B.

[0113] In FIG6A, an organic layer 114 is provided on the top and side surfaces covering the organic layers 112R, 112G and 112B. The organic layer 114 can prevent short circuits caused by contact between the pixel electrode 111 and the common electrode 113.

[0114] In the example shown in FIG6A, an example is shown where the organic layer 114, the common electrode 113 and the protective layer 121 have openings that overlap with the transmission region 40 and the transmission region 40 includes the protective layer 122.

[0115] FIG6B shows an example including an insulating layer 125 disposed in contact with the sides of organic layers 112R, 112G, 112B and pixel electrode 111. The insulating layer 125 can effectively prevent electrical short circuit between pixel electrode 111 and common electrode 113 and leakage current between them.

[0116] The insulating layer 125 may be an insulating layer containing inorganic materials. Inorganic insulating films such as oxide insulating films, nitride insulating films, oxynitride insulating films, and oxynitride insulating films can be used as the insulating layer 125. The insulating layer 125 may be a single-layer structure or a multilayer structure. Examples of oxide insulating films include silicon oxide films, aluminum oxide films, magnesium oxide films, indium gallium zinc oxide films, gallium oxide films, germanium oxide films, yttrium oxide films, zirconium oxide films, lanthanum oxide films, neodymium oxide films, hafnium oxide films, and tantalum oxide films. Examples of nitride insulating films include silicon nitride films and aluminum nitride films. Examples of oxynitride insulating films include silicon oxynitride films and aluminum oxynitride films. Examples of oxynitride insulating films include silicon oxynitride films and aluminum oxynitride films. In particular, by using inorganic insulating films such as alumina film, hafnium oxide film, and silicon oxide film formed by the ALD method for insulating layer 125, an insulating layer 125 with fewer pinholes and excellent protection of the organic layer can be formed.

[0117] In this specification, etc., "oxynitride" refers to a material in which the oxygen content is greater than the nitrogen content in its composition, and "nitrogen oxide" refers to a material in which the nitrogen content is greater than the oxygen content in its composition. For example, "silicon oxynitride" refers to a material in which the oxygen content is greater than the nitrogen content in its composition, and "silicon oxynitride" refers to a material in which the nitrogen content is greater than the oxygen content in its composition.

[0118] The insulating layer 125 can be formed using sputtering, CVD, PLD, ALD, etc. Preferably, the insulating layer 125 is formed using the ALD method, which has excellent coverage.

[0119] Note that although an example is shown in FIG6B, etc., in which a common electrode 113 is provided in the transmission region 40, it is also possible to process the material without providing such a electrode in the transmission region 40.

[0120] In Figures 6C and 6D, a resin layer 126 is provided between two adjacent light-emitting elements to fill the gaps between two opposing pixel electrodes and the gaps between two opposing organic layers. The resin layer 126 can planarize the surfaces on which the organic layer 114, the common electrode 113, etc. are formed, and can prevent the common electrode 113 from disconnecting due to poor coverage of the steps between adjacent light-emitting elements.

[0121] As the resin layer 126, an insulating layer containing organic materials can be suitable. For example, acrylic resin, polyimide resin, epoxy resin, imide resin, polyimide resin, polyimide-polyamide resin, silicone resin, silicone resin, benzocyclobutene resin, phenolic resin, and precursors of the above resins can be used as the resin layer 126. Additionally, organic materials such as polyvinyl alcohol (PVA), polyvinyl butyral, polyvinylpyrrolidone, polyethylene glycol, polyglycerol, pullulan, water-soluble cellulose, or alcohol-soluble polyamide resin can also be used as the resin layer 126. Furthermore, a photosensitive resin can also be used as the resin layer 126. A photoresist can also be used as the photosensitive resin. Positive or negative materials can also be used as the photosensitive resin.

[0122] Alternatively, the resin layer 126 can be colored with a material (e.g., a material containing black pigment) to suppress stray light from adjacent pixels and thus suppress color mixing.

[0123] Figure 6C shows an example where a resin layer 126, an organic layer 114, a common electrode 113, and a protective layer 121 are disposed in the transparent region 40. In this case, the resin layer 126 is preferably made of a material with the highest possible light transmittance.

[0124] Additionally, Figure 6D shows an example of resin layer 126 having an opening that overlaps with the permeable region 40.

[0125] In Figures 6E and 6F, an insulating layer 125 and a resin layer 126 disposed on the insulating layer 125 are provided. Since the insulating layer 125, the organic layer 112R, etc., do not contact the resin layer 126, it is possible to prevent impurities such as moisture in the resin layer 126 from diffusing into the organic layer 112R, etc., thereby providing a display device with high reliability.

[0126] Alternatively, a reflective film (e.g., a metal film selected from one or more of silver, palladium, copper, titanium and aluminum) can be provided between the insulating layer 125 and the resin layer 126 to add the function of reflecting the light emitted by the light-emitting layer and improving the light extraction efficiency.

[0127] Figure 6E shows an example where an insulating layer 125, a resin layer 126, an organic layer 114, a common electrode 113, and a protective layer 121 are provided in the transparent region 40. In this case, the insulating layer 125 and the resin layer 126 are preferably made of materials with the highest possible light transmittance.

[0128] Additionally, Figure 6F shows an example where the insulating layer 125 and the resin layer 126 have openings that overlap with the transparent region 40.

[0129] Figures 7A to 7E show examples where the width of pixel electrode 111 is larger than the width of organic layer 112R, organic layer 112G, and organic layer 112B. Organic layer 112R, etc., are located inside the end of pixel electrode 111.

[0130] FIG7A shows an example including insulating layer 125. Insulating layer 125 is provided in such a way that it covers the sides of the organic layers of two adjacent light-emitting elements, a portion of the top surface of pixel electrode 111 and the sides.

[0131] Although FIG7A shows an example in which an insulating layer 125, an organic layer 114, a common electrode 113 and a protective layer 121 are provided in the transmission region 40, it is not limited to this and the above-described structure having one or more openings overlapping with the transmission region 40 can also be used.

[0132] Figures 7B and 7C show an example including the resin layer 126. The resin layer 126 is located between two adjacent light-emitting elements and is disposed in such a way that it covers the side surface of the organic layer and the top and side surfaces of the pixel electrode 111.

[0133] FIG7B shows an example in which a resin layer 126, an organic layer 114, a common electrode 113, and a protective layer 121 are provided in the transmission region 40. FIG7C shows an example in which the resin layer 126, the organic layer 114, the common electrode 113, and the protective layer 121 each have an opening that overlaps with the transmission region 40.

[0134] Figures 7D and 7E show examples of both the insulating layer 125 and the resin layer 126. An insulating layer 125 is provided between the organic layer 112R and the resin layer 126.

[0135] FIG7D shows an example in which an insulating layer 125, a resin layer 126, an organic layer 114, a common electrode 113, and a protective layer 121 are provided in the transmission region 40. FIG7E shows an example in which the insulating layer 125, the resin layer 126, the organic layer 114, the common electrode 113, and the protective layer 121 each have an opening that overlaps with the transmission region 40.

[0136] Figures 8A to 8F show examples where the width of pixel electrode 111 is smaller than the width of organic layer 112R, organic layer 112G, and organic layer 112B. Organic layer 112R and the like extend outward beyond the end of pixel electrode 111.

[0137] Figure 8A shows an example where the organic layer 114, the common electrode 113 and the protective layer 121 each have an opening that overlaps with the permeable region 40.

[0138] FIG8B shows an example including an insulating layer 125. The insulating layer 125 is provided in such a way that it contacts the side surfaces of the organic layers of two adjacent light-emitting elements. In addition, the insulating layer 125 can be provided not only to cover the side surfaces of the organic layers 112R, etc., but also to cover a portion of their top surfaces.

[0139] Although Figure 8B shows an example in which an insulating layer 125, an organic layer 114, a common electrode 113 and a protective layer 121 are provided in the transmission region 40, it is not limited to this and the above-described structure with one or more openings overlapping the transmission region 40 can also be used.

[0140] Figures 8C and 8D show an example including a resin layer 126. The resin layer 126 is located between two adjacent light-emitting elements and is disposed such that it covers a portion of the side surface and top surface of the organic layer 112R, etc. Alternatively, the resin layer 126 may be configured to contact the side surface of the organic layer 112R, etc., without covering the top surface.

[0141] FIG8C shows an example in which a resin layer 126, an organic layer 114, a common electrode 113, and a protective layer 121 are provided in the transmission region 40. FIG8D shows an example in which the resin layer 126, the organic layer 114, the common electrode 113, and the protective layer 121 each have an opening that overlaps with the transmission region 40.

[0142] Figures 8E and 8F show examples of both the insulating layer 125 and the resin layer 126. An insulating layer 125 is provided between the organic layer 112R and the resin layer 126.

[0143] FIG8E shows an example in which an insulating layer 125, a resin layer 126, an organic layer 114, a common electrode 113, and a protective layer 121 are provided in the transmission region 40. FIG8F shows an example in which the insulating layer 125, the resin layer 126, the organic layer 114, the common electrode 113, and the protective layer 121 each have an opening that overlaps with the transmission region 40.

[0144] Here, an example of the structure of the resin layer 126 described above will be explained.

[0145] The flatter the top surface of the resin layer 126, the better. However, sometimes the surface of the resin layer 126 is concave or convex due to the concave or convex shape of the surface to which the resin layer 126 is formed, the formation conditions of the resin layer 126, etc.

[0146] Figures 9A, 9B, and 9C show enlarged views of the resin layer 126 and its vicinity when the top surface of the resin layer 126 is flat. Figure 9A shows an example where the width of the organic layer 112R, etc., is larger than that of the pixel electrode 111. Figure 9B shows an example where the widths of the pixel electrode 111 and the organic layer 112R, etc., are approximately the same. Figure 9C shows an example where the width of the organic layer 112R, etc., is smaller than that of the pixel electrode 111.

[0147] As shown in FIG9A, since the organic layer 112R is provided to cover the end of the pixel electrode 111, it is preferable that the end of the pixel electrode 111 is tapered. This improves the step coverage of the organic layer 112R, thereby providing a highly reliable display device.

[0148] Figures 9D, 9E and 9F show an example where the top surface of the resin layer 126 is concave. In this case, the top surfaces of the organic layer 114, the common electrode 113 and the protective layer 121 are formed with concave portions that reflect the concave top surface of the resin layer 126.

[0149] Figures 10A, 10B and 10C show an example where the top surface of the resin layer 126 is convex. In this case, the top surfaces of the organic layer 114, the common electrode 113 and the protective layer 121 are formed with convex portions that reflect the convex top surface of the resin layer 126.

[0150] Figures 10D, 10E and 10F show examples where a portion of the resin layer 126 covers a portion of the upper end and top surface of the organic layer 112R and a portion of the upper end and top surface of the organic layer 112G. In this case, an insulating layer 125 is provided between the resin layer 126 and the top surface of the organic layer 112R or the organic layer 112G.

[0151] Additionally, Figures 10D, 10E, and 10F show examples where a portion of the top surface of the resin layer 126 is concave. In this case, the organic layer 114, the common electrode 113, and the protective layer 121 are formed with an uneven shape that reflects the shape of the resin layer 126.

[0152] [Example of pixel structure] The following is an example of pixel structure.

[0153] Figure 11A1 shows a top view of a pixel 30 viewed from one side of the display surface. Pixel 30 includes three sub-pixels, each having a light-emitting element 90R, a light-emitting element 90G, or a light-emitting element 90B. Each sub-pixel is provided with a transistor 61 and a transistor 62. In addition, pixel 30 includes wiring 51, wiring 52, wiring 53, etc.

[0154] Wiring 51 can be used, for example, as a scan line. Wiring 52 can be used, for example, as a signal line. Wiring 53 can be used, for example, as wiring to supply potential to a light-emitting element. Wiring 51 and wiring 52 have intersecting portions. Here, an example is shown where wiring 53 is parallel to wiring 52. Wiring 53 can also be parallel to wiring 51.

[0155] Transistor 61 is used as a selection transistor. The gate of transistor 61 is electrically connected to wiring 51, and one of its source and drain is electrically connected to wiring 52. Transistor 62 is a transistor that controls the current flowing through the light-emitting element; it can also be called a driver transistor. One of the source and drain of transistor 62 is electrically connected to wiring 53, and the other is electrically connected to the light-emitting element.

[0156] In Figure 11A1, light-emitting element 90R, light-emitting element 90G and light-emitting element 90B have vertically elongated rectangular shapes and are arranged in a striped pattern.

[0157] Here, wiring 51, wiring 52, and wiring 53 are light-shielding. Other layers, that is, the layers constituting transistors 61 and 62, can use light-transmitting films. Figure 11A2 shows an example where the pixel 30 shown in Figure 11A1 is divided into a transmissive region 30t that transmits visible light and a light-shielding region 30s that blocks visible light. Thus, by making all areas except those containing wirings transmissive regions 30t, visibility during perspective display can be improved.

[0158] Figures 11B1 and 11B2 show an example of a pixel 30 including four sub-pixels: light-emitting element 90R, light-emitting element 90G, light-emitting element 90B, and light-emitting element 90W. Light-emitting element 90W can be, for example, a light-emitting element that emits white light. Furthermore, the examples shown in Figures 11B1 and 11B2 illustrate an arrangement of two light-emitting elements vertically and two horizontally within a pixel 30. Additionally, in Figure 11B1, pixel 30 is provided with two wirings 51, two wirings 52, and two wirings 53.

[0159] As shown in Figure 11B2, the area that overlaps with each wiring is the light-blocking area 30s, and the area that does not overlap is the light-transmitting area 30t.

[0160] Here, the higher the ratio of the area of ​​the transparent region to the area of ​​the display area, the greater the amount of light transmitted. For example, the ratio of the area of ​​the transparent region to the area of ​​the entire display area can be 1% to 95%, preferably 10% to 90%, and more preferably 20% to 80%. Particularly preferred is 40% or more or 50% or more.

[0161] Figures 12A1 and 12A2 show examples where wiring 51, wiring 52, and wiring 53 in Figures 11A1 and 12A2 are translucent. Similarly, Figures 12B1 and 12B2 show examples where wiring 51, wiring 52, and wiring 53 in Figures 11B1 and 12B2 are translucent. Thus, as shown in Figures 12A2 and 12B2, all areas of pixel 30 can be made to be translucent areas 30t.

[0162] [Example 2 of pixel arrangement method] The following describes an example of a pixel arrangement method applicable to a high-definition display device.

[0163] For example, by adopting the structure shown below, a display device with a resolution of 500 ppi or more, 1000 ppi or more, 2000 ppi or more, 3000 ppi or more, or even 5000 ppi or more, including the light-emitting element, can be realized.

[0164] [Structure Example of Pixel Circuit] Figure 13A shows an example of a circuit diagram of pixel unit 70. Pixel unit 70 is composed of two pixels (pixel 70a and pixel 70b). In addition, pixel unit 70 is connected to wiring 51a, wiring 51b, wiring 52a, wiring 52b, wiring 52c, wiring 52d, wiring 53a, wiring 53b, wiring 53c, etc.

[0165] Pixel 70a includes sub-pixels 71a, 72a, and 73a. Pixel 70b includes sub-pixels 71b, 72b, and 73b. Sub-pixels 71a, 72a, and 73a each include pixel circuits 41a, 42a, and 43a. Additionally, sub-pixels 71b, 72b, and 73b each include pixel circuits 41b, 42b, and 43b.

[0166] Each sub-pixel includes a pixel circuit and a display element 60. For example, sub-pixel 71a includes a pixel circuit 41a and a display element 60. Here, a case is shown where a light-emitting element such as an organic EL element is used as the display element 60.

[0167] Wiring 51a and wiring 51b are used as scan lines (also called gate lines). Wiring 52a, wiring 52b, wiring 52c and wiring 52d are used as signal lines (also called source lines or data lines). In addition, wiring 53a, wiring 53b and wiring 53c are used as power lines that provide potential to the display element 60.

[0168] Pixel circuit 41a is electrically connected to wiring 51a, wiring 52a, and wiring 53a. Pixel circuit 42a is electrically connected to wiring 51b, wiring 52d, and wiring 53a. Pixel circuit 43a is electrically connected to wiring 51a, wiring 52b, and wiring 53b. Pixel circuit 41b is electrically connected to wiring 51b, wiring 52a, and wiring 53b. Pixel circuit 42b is electrically connected to wiring 51a, wiring 52c, and wiring 53c. Pixel circuit 43b is electrically connected to wiring 51b, wiring 52b, and wiring 53c.

[0169] As shown in Figure 13A, by using a structure where one pixel connects two gate lines, the number of source lines can be reduced to half that of the stripe configuration. Therefore, the number of ICs used as source drive circuits can be reduced by half, thus reducing the number of components.

[0170] Furthermore, it is preferable to employ a structure in which a wiring used as a signal line is connected to a pixel circuit corresponding to the same color. For example, when a signal that adjusts the potential of a pixel is supplied to the aforementioned wiring in order to correct for uneven brightness between pixels, the correction value sometimes varies greatly depending on the color. Therefore, by connecting a signal line to a pixel circuit corresponding to the same color, correction can be easily performed.

[0171] Additionally, each pixel circuit includes a transistor 61, a transistor 62, and a capacitor 63. For example, in pixel circuit 41a, the gate of transistor 61 is electrically connected to wiring 51a, one of the source and drain of transistor 61 is electrically connected to wiring 52a, and the other of the source and drain is electrically connected to the gate of transistor 62 and one electrode of capacitor 63. One of the source and drain of transistor 62 is electrically connected to one electrode of display element 60, and the other of the source and drain is electrically connected to the other electrode of capacitor 63 and wiring 53a. The other electrode of display element 60 is electrically connected to the wiring supplied with potential V1.

[0172] Regarding other pixel circuits, as shown in FIG13A, except for the wiring connected to the gate of transistor 61, the wiring connected to one of the source and drain of transistor 61, and the wiring connected to the other electrode of capacitor 63, its structure is the same as that of pixel circuit 41a.

[0173] In Figure 13A, transistor 61 has the function of selecting a transistor. Transistor 62 is connected in series with display element 60 and has the function of controlling the current flowing through display element 60. Capacitor 63 has the function of maintaining the potential of the node connected to the gate of transistor 62. When the leakage current of transistor 61 in the off state and the leakage current through the gate of transistor 62 are extremely small, capacitor 63 may not be provided.

[0174] Here, as shown in FIG13A, the transistor 62 preferably includes a first gate and a second gate electrically connected to each other. In this way, by adopting a structure with two gates, the current that the transistor 62 can carry can be increased. Especially in high-definition display devices, it is preferable to increase the current without increasing the size of the transistor 62 (especially the channel width).

[0175] Transistor 62 may also have one gate. By adopting the above structure, the process of forming a second gate is not required, which simplifies the process compared to the above structure. Alternatively, transistor 61 may also have two gates. By adopting the above structure, the size of these transistors can be reduced. In addition, the first gate and the second gate of each transistor are electrically connected to each other. Alternatively, a structure may be adopted in which one gate is not electrically connected to other gates but is electrically connected to other wiring. In this case, the critical voltage of the transistor can be controlled by providing different potentials to the two gates.

[0176] Furthermore, the electrode in the pair of electrodes of the display element 60 that is electrically connected to the transistor 62 corresponds to a pixel electrode (e.g., conductive layer 91). Here, FIG13A shows a structure in which the electrode electrically connected to the transistor 62 of the display element 60 is used as a cathode and the electrode on the opposite side is used as an anode. This structure is particularly effective when the transistor 62 is an n-channel transistor. That is, when the transistor 62 is in the on state, the potential supplied by the wiring 53a becomes the source potential, thereby making the current flowing through the transistor 62 constant, regardless of the resistance deviation and variation of the display element 60. As the transistor included in the pixel circuit, a p-channel transistor can also be used.

[0177] Note that the pixel circuit with two transistors and a capacitor is described here as a simple example, but the structure of the pixel circuit is not limited to this, and various structures with select transistors and drive transistors can also be used.

[0178] [Example of Pixel Electrode Configuration Method] Figure 13B is a top view showing an example of the configuration method of each pixel electrode and each wiring in the display area. Wiring 51a and wiring 51b are arranged alternately. Wiring 52a, wiring 52b and wiring 52c, which intersect with wiring 51a and wiring 51b, are arranged sequentially. In addition, each pixel electrode is arranged in a matrix along the extension direction of wiring 51a and wiring 51b.

[0179] Pixel unit 70 includes pixel 70a and pixel 70b. Pixel 70a includes pixel electrode 91R1, pixel electrode 91G1, and pixel electrode 91B1. Pixel 70b includes pixel electrode 91R2, pixel electrode 91G2, and pixel electrode 91B2. Furthermore, the display area of ​​a sub-pixel is located inside the pixel electrodes included in that sub-pixel.

[0180] As shown in FIG13B, when the period of arrangement in the extension direction (also called the first direction) of the wiring 52a, etc., of the pixel unit 70 is called the period P, it is preferable that the period of arrangement in the extension direction (also called the second direction) of the wiring 51a, etc., is twice that period (period 2P). This allows for a display without distortion. Here, the period P can be 1 μm or more and 150 μm or less, preferably 2 μm or more and 120 μm or less, more preferably 3 μm or more and 100 μm or less, and even more preferably 4 μm or more and 60 μm or less. This enables a display device with extremely high resolution.

[0181] For example, it is preferable that the pixel electrode 91R1, etc., is arranged in a manner that does not overlap with the wiring 52a, etc., which is used as a signal line. As a result, it is possible to suppress the occurrence of situations where electrical noise is transferred via capacitance between the wiring 52a, etc. and the pixel electrode 91R1, etc., causing a change in the potential of the pixel electrode 91R1, etc., resulting in a change in the brightness of the display element.

[0182] Alternatively, the pixel electrode 91R1, etc., can be arranged to overlap with the wiring 51a, etc., which are used as scan lines. This increases the area of ​​the pixel electrode 91R1, thereby improving the aperture ratio. Figure 13B shows an example where a portion of the pixel electrode 91R1 overlaps with the wiring 51a.

[0183] When the pixel electrode 91R1 of a certain sub-pixel is arranged to overlap with the wiring 51a used as a scan line, it is preferable that the wiring is a wiring connected to the pixel circuit of the sub-pixel. For example, since the period of the signal of potential change of the input wiring 51a is equivalent to the period of rewriting the data of the sub-pixel, even if electrical noise is transmitted from the wiring 51a to the pixel electrode through a capacitor, the brightness of the sub-pixel will not change.

[0184] 〔Example 1 of pixel layout〕 The following is an example of the layout of pixel unit 70.

[0185] Figure 14A shows an example of the layout of a sub-pixel. Here, for ease of understanding, an example of the state before the formation of the pixel electrodes is shown. The sub-pixel shown in Figure 14A includes transistor 61, transistor 62, and capacitor 63. Transistor 61 is a bottom-gate channel etched transistor. Transistor 62 includes two gates with a semiconductor layer sandwiched between them.

[0186] The lower gate electrode of transistors 61 and 62, and one electrode of capacitor 63 are formed by the conductive layer 56 located on the lower side. Wiring 51 is formed by the conductive layer formed after the conductive layer 56. Furthermore, one of the source and drain electrodes of transistor 61, and the source and drain electrodes of transistor 62 are formed by the conductive layer 57 formed thereafter. Furthermore, wiring 52, wiring 53, etc., are formed by the conductive layer formed after the conductive layer 57. Furthermore, the upper gate electrode of transistor 62 is formed by the conductive layer 58 formed thereafter. A portion of wiring 52 serves as the other of the source and drain electrodes of transistor 61. Furthermore, a portion of wiring 53 serves as the other electrode of capacitor 63. Note that, for ease of understanding, the conductive layer 58 is shown only in outline without additional shading.

[0187] Here, the semiconductor layer 55, conductive layer 56, conductive layer 57 and conductive layer 58 in each transistor are transparent. On the other hand, the wiring 51, wiring 52 and wiring 53 are light-shielding.

[0188] Figure 14B shows a diagram in which the transparent region 30t and the light-blocking region 30s in the sub-pixel shown in Figure 14A are shown separately. In this way, since the transistors 61, 62, etc. are transparent, the visibility of the perspective display can be improved.

[0189] For example, by adopting the above structure, the ratio of the area of ​​the transmission region 30t (also known as the transmission area ratio) can be 50% or more. The structures shown in Figures 14A and 14B can achieve a transmission area ratio of approximately 66.1% or more.

[0190] FIG14C shows an example of the layout of pixel unit 70 using the sub-pixels shown in FIG14A. FIG14C also shows each pixel electrode and display area 22. Here, an example of using a double-sided emitting light-emitting element is shown as the light-emitting element, and FIG14C is a top view schematic diagram viewed from the display surface side. In addition, FIG14D is a diagram showing FIG14C divided into a transparent area 30t and a light-blocking area 30s.

[0191] Here, an example is shown of a structure in which three sub-pixels electrically connected to wiring 51a and three sub-pixels electrically connected to wiring 51b are reversed to each other. Thus, when sub-pixels of the same color are arranged in a zigzag pattern in the extension direction of wiring 52a, etc., and connected to a wiring used as a signal line, the length of the wiring within the sub-pixels can be made uniform, thereby suppressing brightness deviations between sub-pixels.

[0192] By adopting the above pixel layout, even using a mass production line with a minimum feature size of 0.5μm to 6μm, typically 1.5μm to 4μm, it is possible to manufacture a display device with extremely high resolution.

[0193] 〔Example 2 of pixel layout〕 Figures 15A and 15B show examples of layouts that are different from those in Figures 14A and 14B.

[0194] Transistor 61 is a top-gate type transistor. Transistor 62 is a transistor comprising two gates with a semiconductor layer sandwiched between them.

[0195] In FIG. 15A, a gate electrode of transistor 62 is formed by the conductive layer 57 located on the lower side, and a semiconductor layer 55 is formed after the conductive layer 57. Furthermore, a gate electrode of transistor 61 and another gate electrode of transistor 62 are formed by a conductive layer 56 formed after the conductive layer 57 and the semiconductor layer 55. Wiring 51 and the like are formed by the conductive layer formed after the conductive layer 56. Furthermore, wiring 52 and an electrode of capacitor 63 are formed by the conductive layer formed thereafter. Furthermore, wiring 53 and the like are formed by the conductive layer formed thereafter.

[0196] Here, the semiconductor layer 55, the conductive layer 56, and the conductive layer 57 are transparent. The structures shown in Figures 15A and 15B can achieve a transmittance of approximately 37.1% or more.

[0197] Transistor 61 includes a semiconductor layer 55 disposed on wiring 51 and a portion of wiring 52, etc. Transistor 62 includes a conductive layer 57, a semiconductor layer 55 disposed on the conductive layer 57, and wiring 53, etc. Capacitor 63 includes a portion of wiring 53 and a conductive layer formed on the same surface as wiring 52.

[0198] Figures 15C and 15D show examples of the structure of a pixel unit using the sub-pixel shown in Figure 15A.

[0199] 〔Example 3 of pixel layout〕 Figures 16A and 16B show examples of subpixel 50 layouts that are different from those in Figures 14A, 14B, 15A, and 15B.

[0200] Sub-pixel 50 includes transistors 61a, 61b, and 62. Transistors 61a, 61b, and 62 are transistors that include two gates with a semiconductor layer sandwiched between them. Figure 16A also shows pixel electrode 64 and display area 22. Note that pixel electrode 64 spans the adjacent pixel (omitted).

[0201] In FIG16A, transistor 62 has the same stacked structure as transistor 62 shown in FIG15A.

[0202] Transistor 61a includes a semiconductor layer 55 disposed on wiring 51, a conductive layer 58 disposed on semiconductor layer 55, and a conductive layer connected to wiring 59 which is supplied with a constant potential. Transistor 61b includes a semiconductor layer 55 disposed on wiring 51, a conductive layer 58 disposed on semiconductor layer 55, and a conductive layer connected to wiring 52. The conductive layer 58 is connected to wiring 59. Wiring 51 and conductive layer 58 serve as gate electrodes.

[0203] Here, wiring 51, wiring 52, wiring 53, and wiring 59 are light-shielding. The layers other than these, that is, the layers constituting transistors 61a, 61b, transistor 62, etc., use films that are light-transmitting. Figure 16B shows an example of dividing the sub-pixel 50 shown in Figure 16A into a transmissive region 30t that transmits visible light and a light-shielding region 30s that blocks visible light. As shown in Figure 16B, the region that does not overlap with each wiring is the transmissive region 30t.

[0204] Here, as a comparative example, Figures 17A and 17B show a sub-pixel 50a including a transistor containing a portion of wiring 51, a portion of wiring 52 and a portion of wiring 59.

[0205] Sub-pixel 50a includes transistors 61c, 61d, and 62a. Transistors 61c, 61d, and 62a are transistors that include two gates with a semiconductor layer sandwiched between them. Figure 17A also shows pixel electrode 64 and display area 22.

[0206] In FIG17A, transistor 62a has the same stacked structure as transistor 62 shown in FIG15A.

[0207] Transistor 61c includes a semiconductor layer 55 disposed on wiring 51, a conductive layer 58 disposed on semiconductor layer 55, and a portion of wiring 59. Transistor 61d includes a semiconductor layer 55 disposed on wiring 51, a conductive layer 58 disposed on semiconductor layer 55, and a portion of wiring 52.

[0208] Although not shown, the conductive layer of transistor 62a, which serves as the gate electrode, source electrode, and drain electrode, has light-shielding properties. Figure 17B shows an example of dividing the sub-pixel 50a shown in Figure 17A into a transmittance region 30t that transmits visible light and a light-shielding region 30s that blocks visible light. As shown in Figure 17B, the region that does not overlap with each wiring is the transmittance region 30t.

[0209] Furthermore, in a display panel with a pixel size of 12.75μm × 38.25μm, a diagonal size of 13.3 inches, a resolution of 8K, and a top-emitting light-emitting element, when the sub-pixel 50a structure shown in FIG. 17 is adopted, the ratio of the display area 22 in the pixel is 30.1% and the transmittance of the pixel is 11.5%. When the sub-pixel 50 structure shown in FIG. 16 is adopted, the ratio of the display area 22 is 30.1% and the transmittance is 57.6%. The pixel layout of FIG. 16 can improve the light transmittance.

[0210] The above describes the pixel configuration method.

[0211] A display device according to one embodiment of the present invention can increase the ratio of the area of ​​the transparent area per unit area of ​​the display area (transmittance area ratio), thereby providing the user with a transparent display of bright and seamless images. In addition, the light-emitting elements can be formed separately without using FMM, thereby realizing a display device with both high transmittance area ratio and high effective light-emitting area ratio (the ratio of the area of ​​the light-emitting area per unit area of ​​the display area, also known as aperture ratio).

[0212] Embodiment 2 In this embodiment, an example of the structure of a display device according to an embodiment of the present invention will be described.

[0213] 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 as a display unit for devices such as: electronic devices with large screens, such as televisions, desktop or laptop computers, monitors for computers, digital signage, large game consoles such as pinball machines, etc.; digital cameras; digital video cameras; digital photo frames; mobile phones; portable game consoles; smartphones; watch-type terminals; tablet terminals; portable information terminals; and audio playback devices.

[0214] [Display Device 400] FIG18 shows a perspective view of display device 400, and FIG19A shows a cross-sectional view of display device 400.

[0215] The display device 400 has a structure that attaches a substrate 452 and a substrate 451. In FIG18, the substrate 452 is indicated by a dashed line.

[0216] The display device 400 includes a display unit 462, a circuit 464, and wiring 465, etc. Figure 13 shows an example in which an IC 473 and an FPC 472 are installed in the display device 400. Therefore, the structure shown in Figure 13 can also be referred to as a display module including the display device 400, the IC (integrated circuit), and the FPC.

[0217] As circuit 464, for example, a scan line drive circuit can be used.

[0218] Wiring 465 has the function of supplying signals and power to display unit 462 and circuit 464. The signals and power are input to wiring 465 from the outside via FPC 472 or from IC 473.

[0219] Figure 18 shows an example of IC 473 being mounted on substrate 451 using COG (Chip On Glass) or COF (Chip on Film) methods. IC 473 can be, for example, an IC including scan line drive circuitry or signal line drive circuitry. Note that the display device 400 and display module do not necessarily need to have an IC mounted on them. Alternatively, the IC can be mounted on an FPC using COF or similar methods.

[0220] FIG19A shows an example of a cross-section of a portion of the display device 400 including the FPC 472, a portion of the circuit 464, a portion of the display section 462, and a portion of the region including the connection section. FIG19A particularly shows an example of a cross-section of the region of the display section 462 including the light-emitting element 430b emitting green light and the light-emitting element 430c emitting blue light.

[0221] The display device 400 shown in FIG19A includes transistors 202, transistors 210, light-emitting elements 430b and 430c between substrates 453 and 454.

[0222] The light-emitting elements 430b and 430c can be the light-emitting elements illustrated in Embodiment 1.

[0223] Here, when the pixels of the display device include three sub-pixels having light-emitting elements that emit different colors from each other, examples of the three sub-pixels are sub-pixels of three colors: red (R), green (G), and blue (B), and sub-pixels of three colors: yellow (Y), cyan (C), and magenta (M). When four of the above-mentioned sub-pixels are included, examples of the four sub-pixels are sub-pixels of four colors: R, G, B, and white (W), and sub-pixels of four colors: R, G, B, and Y.

[0224] Furthermore, the substrate 454 and the protective layer 416 are bonded together by an adhesive layer 442. The adhesive layer 442 overlaps with the light-emitting elements 430b and 430c respectively, and the display device 400 adopts a solid sealing structure. The substrate 454 is provided with a light-shielding layer 417.

[0225] The light-emitting elements 430b and 430c, as pixel electrodes, include conductive layers 411a, 411b, and 411c. The conductive layer 411b is reflective to visible light and is used as a reflective electrode. The conductive layer 411c is transmissive to visible light and is used as an optical adjustment layer.

[0226] The conductive layer 411a is electrically connected to the conductive layer 222b included in the transistor 210 through an opening provided in the insulating layer 214. The transistor 210 has the function of controlling the driving of the light-emitting element.

[0227] An EL layer 412G or an EL layer 412B is provided covering the pixel electrode. An insulating layer 421 is provided in contact with the side surfaces of the EL layer 412G and the EL layer 412B, and a resin layer 422 is provided to fill the recesses of the insulating layer 421. An organic layer 414, a common electrode 413, and a protective layer 416 are provided covering the EL layer 412G and the EL layer 412B. By providing the protective layer 416 covering the light-emitting element, impurities such as water can be suppressed from entering the light-emitting element, thereby improving the reliability of the light-emitting element.

[0228] The light emitted by the light-emitting element is emitted toward one side of the substrate 454. The substrate 454 is preferably made of a material with high transmittance to visible light.

[0229] The right side of the light-emitting element 430c shows the transmission area through which the transmitted light T passes. Here, an example is shown where the insulating layer 421, resin layer 422, organic layer 414, and common electrode 413 have openings that overlap with the transmission area. Additionally, in FIG19A, the protective layer 416 covers the sides of the organic layer 414 and the common electrode 413.

[0230] Transistor 202 and transistor 210 are both disposed on substrate 451. These transistors can be formed using the same material and the same process.

[0231] The substrate 453 and the insulating layer 212 are bonded together by the adhesive layer 455.

[0232] The manufacturing method of the display device 400 is as follows: First, a manufacturing substrate having an insulating layer 212, transistors, light-emitting devices, etc., is bonded together with a substrate 454 having a light-shielding layer 417 using an adhesive layer 442; then, the manufacturing substrate is peeled off and bonded to the exposed substrate 453 to transfer the components formed on the manufacturing substrate to the substrate 453. The substrates 453 and 454 are preferably flexible. This improves the flexibility of the display device 400.

[0233] A connection portion 204 is provided in a region of the substrate 453 that does not overlap with the substrate 454. In the connection portion 204, wiring 465 is electrically connected to the FPC 472 via a conductive layer 466 and a connection layer 242. The conductive layer 466 can be obtained by processing a conductive film identical to that of the pixel electrode. Therefore, the connection portion 204 can be electrically connected to the FPC 472 via the connection layer 242.

[0234] Transistors 202 and 210 include: a conductive layer 221 serving as a gate; an insulating layer 211 serving as a gate insulating layer; a semiconductor layer 231 including 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 serving as a gate insulating layer; a conductive layer 223 serving 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.

[0235] Conductive layers 222a and 222b are connected to the low-resistance region 231n through openings provided in the insulating layer 215. One of the conductive layers 222a and 222b is used as a source and the other is used as a drain.

[0236] Figure 19A shows an example of insulating layer 225 covering the top and side surfaces of semiconductor layer. Conductive layers 222a and 222b are connected to low-resistance region 231n through openings provided in insulating layer 225 and insulating layer 215.

[0237] On the other hand, in the transistor 209 shown in FIG19B, the insulating layer 225 overlaps with the channel forming region 231i of the semiconductor layer 231 but does not overlap with the low resistance region 231n. For example, the structure shown in FIG19B can be formed by processing the insulating layer 225 with the conductive layer 223 as a mask. In FIG19B, the insulating layer 215 covers the insulating layer 225 and the conductive layer 223, and the conductive layers 222a and 222b are respectively connected to the low resistance region 231n through the opening of the insulating layer 215. Furthermore, an insulating layer 218 covering the transistor may also be provided.

[0238] There are no particular limitations on the transistor structure included in the display device of this embodiment. For example, a planar transistor, an interlaced transistor, or an anti-interlaced transistor can be used. Furthermore, the transistor can have a top-gate structure or a bottom-gate structure. Alternatively, gates can be provided above and below the semiconductor layer forming the channel.

[0239] Transistors 202 and 210 employ a structure in which a semiconductor layer forming a channel is sandwiched between two gates. Alternatively, the two gates can be connected, and the transistor can be driven by supplying the same signal to both gates. Or, the critical voltage of the transistor can be controlled by applying a potential to one of the two gates to control the critical voltage and applying a potential to the other to drive it.

[0240] There are no particular restrictions on the crystallinity of the semiconductor material used for the semiconductor layer of the transistor. Amorphous semiconductors, single-crystal semiconductors, or crystalline semiconductors other than single-crystal semiconductors (microcrystalline semiconductors, polycrystalline semiconductors, or semiconductors with crystalline regions in part) can be used. When using single-crystal semiconductors or crystalline semiconductors, the degradation of transistor characteristics can be suppressed, so it is preferable.

[0241] The semiconductor layer of the transistor is preferably made of metal oxide (oxide semiconductor). That is, the display device of this embodiment preferably uses a transistor (hereinafter, OS transistor) that contains metal oxide in the channel forming region.

[0242] The band gap of the metal oxide used in the semiconductor layer of the transistor is preferably 2 eV or more, and more preferably 2.5 eV or more. By using a metal oxide with a wider band gap, the off-state current of the OS transistor can be reduced.

[0243] The metal oxide preferably contains at least indium or zinc, and more preferably contains both indium and zinc. For example, the metal oxide preferably contains indium, M (M is selected from one or more of gallium, aluminum, yttrium, tin, silicon, boron, copper, vanadium, beryllium, titanium, iron, nickel, germanium, zirconium, molybdenum, lanthanum, cerium, neodymium, hafnium, tantalum, tungsten, magnesium, and cobalt), and zinc. In particular, M is preferably selected from one or more of gallium, aluminum, yttrium, and tin, and more preferably gallium. Note that the metal oxide containing indium, M, and zinc is sometimes referred to below as an In-M-Zn oxide.

[0244] When using In-M-Zn oxide in metal oxide, the number of In atoms in the In-M-Zn oxide is preferably greater than or equal to the number of M atoms. Examples of atomic ratios of the metal elements in this In-M-Zn oxide include In:M:Zn = 1:1:1 or similar, In:M:Zn = 1:1:1.2 or similar, In:M:Zn = 2:1:3 or similar, In:M:Zn = 3:1:2 or similar, In:M:Zn = 4:2:3 or similar, In:M:Zn = 4:2:4.1 or similar, In:M:Zn = 5:1:3 or similar, In:M:Zn = 5:1:6 or similar, In:M:Zn = 5:1:7 or similar, In:M:Zn = 5:1:8 or similar, In:M:Zn = 6:1:6 or similar, In:M:Zn = 5:2:5 or similar, etc. Furthermore, "similar" composition includes a range of ±30% of the desired atomic ratio. By increasing the atomic ratio of indium in metal oxides, the on-state current or field mobility of transistors can be improved.

[0245] For example, when the composition is described as having an atomic ratio of In:Ga:Zn = 4:2:3 or similar, the following cases are included: as the content ratio of each element, when In is 4, Ga is 1 or more and 3 or less, and Zn is 2 or more and 4 or less. Furthermore, when the composition is described as having an atomic ratio of In:Ga:Zn = 5:1:6 or similar, the following cases are included: as the content ratio of each element, when In is 5, Ga is greater than 0.1 and 2 or less, and Zn is 5 or more and 7 or less. Furthermore, when the composition is described as having an atomic ratio of In:Ga:Zn = 1:1:1 or similar, the following cases are included: as the content ratio of each element, when In is 1, Ga is greater than 0.1 and 2 or less, and Zn is greater than 0.1 and 2 or less.

[0246] The atomic ratio of In in In-M-Zn oxides can also be less than the atomic ratio of M. Examples of such atomic ratios of metal elements in In-M-Zn oxides include compositions with In:M:Zn = 1:3:2 or similar, In:M:Zn = 1:3:3 or similar, and In:M:Zn = 1:3:4 or similar. By increasing the atomic ratio of M in the metal oxide, the band gap of the In-M-Zn oxide can be widened, thereby improving its resistance to optical negative bias stress testing. Specifically, the change in critical voltage or drift voltage (Vsh) measured in the NBTIS (Negative Bias Temperature Illumination Stress) test of the transistor can be reduced. Note that the drift voltage (Vsh) is defined as Vg at the intersection of the tangent line at the point where the slope of the transistor's drain current (Id) - gate voltage (Vg) curve is greatest and the straight line with Id = 1 pA.

[0247] Alternatively, the semiconductor layer of the transistor may also contain silicon. Examples of silicon include amorphous silicon and crystalline silicon (low-temperature polycrystalline silicon, monocrystalline silicon, etc.).

[0248] Alternatively, the semiconductor layer of a transistor may also have a layered material that serves as a semiconductor. Layered materials are a general term for a group of materials with a layered crystalline structure. A layered crystalline structure is a structure in which layers formed by covalent or ionic bonds are stacked by bonds weaker than covalent or ionic bonds, such as van der Waals forces. Layered materials have high conductivity per unit layer, that is, high two-dimensional conductivity. By using a material that serves as a semiconductor and has high two-dimensional conductivity in the channel forming region, a transistor with high on-state current can be provided.

[0249] Examples of the aforementioned layered materials include graphene, silicon, and chalcogenides. Chalcogenides are compounds containing chalcogen elements (elements belonging to Group 16). Furthermore, examples of chalcogenides include transition metal chalcogenides and Group 13 chalcogenides. Specific examples of transition metal chalcogenides that can be used as semiconductor layers in transistors include molybdenum sulfide (typically MoS2), molybdenum selenide (typically MoSe2), molybdenum telluride (typically MoTe2), tungsten sulfide (typically WS2), tungsten selenide (typically WSe2), tungsten telluride (typically WTe2), hafnium sulfide (typically HfS2), hafnium selenide (typically HfSe2), zirconium sulfide (typically ZrS2), and zirconium selenide (typically ZrSe2).

[0250] The transistors included in circuit 464 and the transistors included in display unit 462 may have the same structure or different structures. The multiple transistors included in circuit 464 may have the same structure or two or more different structures. Similarly, the multiple transistors included in display unit 462 may have the same structure or two or more different structures.

[0251] Preferably, at least one of the insulating layers covering the transistor is made of a material that does not readily diffuse impurities such as water and hydrogen. This allows the insulating layer to function as a barrier layer. By employing this structure, the diffusion of impurities from the outside into the transistor can be effectively suppressed, thereby improving the reliability of the display device.

[0252] Inorganic insulating films are preferably used as insulating layers 211, 212, 215, 218, and 225. Examples of inorganic insulating films include silicon nitride films, silicon oxynitride films, silicon oxide films, silicon oxynitride films, aluminum oxide films, and aluminum nitride films. Additionally, hafnium oxide films, yttrium oxide films, zirconium oxide films, gallium oxide films, tantalum oxide films, magnesium oxide films, lanthanum oxide films, cerium oxide films, and neodymium oxide films can also be used. Furthermore, two or more of the above-mentioned inorganic insulating films can be laminated.

[0253] Here, the barrier properties of organic insulating films are often lower than those of inorganic insulating films. Therefore, it is preferable that the organic insulating film includes an opening near the end of the display device 400. This can suppress impurities from entering the display device 400 through the organic insulating film. Alternatively, the organic insulating film can be formed with its end located inside the end of the display device 400, so that the organic insulating film is not exposed at the end of the display device 400.

[0254] The insulating layer 214 used as the planarization layer is preferably an organic insulating film. Materials suitable for use as organic insulating films include, for example, acrylic resin, polyimide resin, epoxy resin, polyimide resin, polyimide-polyamine resin, silicone resin, benzocyclobutene resin, phenolic resin, and precursors of the above resins.

[0255] Preferably, a light-shielding layer 417 is provided on the surface of the substrate 454 on the substrate 453 side. Furthermore, various optical components can be disposed on the outer side of the substrate 454. As optical components, polarizing plates, retardation plates, light diffusion layers (diffusion films, etc.), anti-reflective layers, and condensing films can be used. In addition, an antistatic film that inhibits dust adhesion, a water-repellent film that is not easily soiled, a hard coating film that inhibits damage during use, and an impact-absorbing layer can also be disposed on the outer side of the substrate 454.

[0256] A connection portion 228 is shown in FIG19A. In the connection portion 228, a common electrode 413 is electrically connected to a wiring. FIG19A shows an example of a case where the wiring adopts the same stacked structure as the pixel electrode.

[0257] Substrates 453 and 454 can be made of glass, quartz, ceramic, sapphire, resin, etc. The substrate on the side from which light is emitted from the light-emitting element uses a material that allows the light to pass through. By using a flexible material for substrates 453 and 454, the flexibility of the display device can be improved. A polarizing plate can be used as substrate 453 or substrate 454.

[0258] As substrates 453 and 454, the following materials can be used: polyester resins such as polyethylene terephthalate (PET) or polyethylene naphthalate (PEN), polyacrylonitrile resin, acrylic resin, polyimide resin, polymethyl methacrylate resin, polycarbonate (PC) resin, polyether ether (PES) resin, polyamide resin (nylon, aromatic polyamide, 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, and cellulose nanofibers, etc. Alternatively, one or both of substrates 453 and 454 can be made of glass with a flexible thickness.

[0259] When a circular polarizer is superimposed on a display device, it is preferable to use a substrate with high optical isotropy as the substrate included in the display device. The substrate with high optical isotropy has lower birefringence (or, in other words, less birefringence).

[0260] The absolute value of the retardation value of the substrate with high optical isotropy is preferably 30 nm or less, more preferably 20 nm or less, and even more preferably 10 nm or less.

[0261] Among thin films with high optical isotropy, examples include cellulose triacetate (also known as TAC) films, cyclic olefin polymer (COP) films, cyclic olefin copolymer (COC) films, and acrylic films.

[0262] When a thin film is used as a substrate, the display panel may experience shape changes such as wrinkles due to water absorption by the film. Therefore, it is preferable to use a thin film with a low water absorption rate as the substrate. For example, it is preferable to use a thin film with a water absorption rate of 1% or less, more preferably a thin film with a water absorption rate of 0.1% or less, and even more preferably a thin film with a water absorption rate of 0.01% or less.

[0263] As the adhesive layer, various curing adhesives can be used, such as UV-curing adhesives, reaction-curing adhesives, thermosetting adhesives, and anaerobic adhesives. Examples of these adhesives include epoxy resins, acrylic resins, silicone resins, phenolic resins, polyimide resins, PVC (polyvinyl chloride) resins, PVB (polyvinyl butyral) resins, and EVA (ethylene vinyl acetate) resins. In particular, materials with low moisture permeability, such as epoxy resins, are preferred. Furthermore, two-component mixed resins can also be used. Additionally, adhesive sheets can also be used.

[0264] As the connecting layer 242, anisotropic conductive film (ACF) or anisotropic conductive paste (ACP) can be used.

[0265] Materials that can be used as gates, sources, and drains of transistors, as well as conductive layers such as wiring and electrodes constituting display devices, include metals such as aluminum, titanium, chromium, nickel, copper, yttrium, zirconium, molybdenum, silver, tantalum, or tungsten, or alloys with the above metals as the main component. Single layers or stacks of films containing these materials can be used.

[0266] Furthermore, as a conductive material with light transmittance, conductive oxides such as indium oxide, indium tin oxide, indium zinc oxide, zinc oxide, and zinc oxide containing gallium, or graphene, can be used. Alternatively, metallic materials such as gold, silver, platinum, magnesium, nickel, tungsten, chromium, molybdenum, iron, cobalt, copper, palladium, or titanium, or alloy materials containing such metallic materials, can be used. Alternatively, nitrides of the metallic materials (e.g., titanium nitride) can also be used. Furthermore, when using metallic materials or alloy materials (or their nitrides), it is preferable to form them thin enough to be light transmittant. In addition, a multilayer film of the above-mentioned materials can be used as a conductive layer. For example, by using a multilayer film of an alloy of silver and magnesium with indium tin oxide, conductivity can be improved, so it is preferable. The above-mentioned materials can also be used as conductive layers constituting various wirings and electrodes of a display device, and as conductive layers included in light-emitting elements (conductive layers used as pixel electrodes or common electrodes).

[0267] Among the insulating materials that can be used in various insulating layers, examples include resins such as acrylic resin or epoxy resin, and inorganic insulating materials such as silicon oxide, silicon oxynitride, silicon oxynitride, silicon nitride, or aluminum oxide.

[0268] At least a portion of the structural examples shown in this embodiment and the corresponding diagrams can be appropriately combined with other structural examples or diagrams.

[0269] At least a portion of this embodiment may be implemented in combination with other embodiments described in this specification.

[0270] Embodiment 3 In this embodiment, a light-emitting element (also called a light-emitting device) of a display device that can be used in one embodiment of the present invention will be described.

[0271] In this specification, etc., devices manufactured using a metal mask or FMM (Fine Metal Mask) are sometimes referred to as devices having an MM (Metal Mask) structure. In addition, in this specification, etc., devices manufactured without a metal mask or FMM are sometimes referred to as devices having an MML (Metal Mask Less) structure.

[0272] Furthermore, in this specification, the structure in which light-emitting devices of each color (here, blue (B), green (G), and red (R)) are separately formed or coated with light-emitting layers is sometimes referred to as an SBS (Side By Side) structure. Additionally, in this specification, a light-emitting device capable of emitting white light is sometimes referred to as a white light-emitting device. A display device that can achieve full-color display by combining a white light-emitting device with a color layer (e.g., a color filter).

[0273] Furthermore, light-emitting devices can be broadly classified into single-structure and series-structure devices. A preferred single-structure device has the following structure: a light-emitting unit is included between a pair of electrodes, and this light-emitting unit includes one or more light-emitting layers. To obtain white light emission with a single structure, the light-emitting layers are selected such that the light emission of each of the two or more light-emitting layers is in a complementary color relationship. For example, by making the light emission color of the first light-emitting layer complementary to the light emission color of the second light-emitting layer, a structure in which the light-emitting device as a whole emits white light can be obtained. The same applies to light-emitting devices including three or more light-emitting layers.

[0274] The series-connected device preferably has the following structure: two or more light-emitting units are included between a pair of electrodes, and 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, a light-emitting device with improved brightness per specified current and higher reliability than a single-structure device can be achieved. To obtain white light emission in the series-connected structure, a structure is adopted to combine the light emitted from the light-emitting layers of multiple light-emitting units to obtain white light emission. Note that the combination of light emission colors to obtain white light emission is the same as in the single-structure structure. Furthermore, in the series-connected device, it is preferable to provide an intermediate layer such as a charge-generating layer between the multiple light-emitting units.

[0275] Furthermore, when comparing the aforementioned white light-emitting devices (single-structure or series-structure) and SBS structure light-emitting devices, the SBS structure light-emitting device can achieve lower power consumption than the white light-emitting device. Therefore, when power consumption reduction is desired, the SBS structure light-emitting device is preferred. On the other hand, the manufacturing process of white light-emitting devices is simpler than that of SBS structure light-emitting devices, thereby reducing manufacturing costs or increasing manufacturing yield, making it preferable.

[0276] <<Structural Example of a Light-Emitting Device>> As shown in Figure 20A, the light-emitting device includes an EL layer 786 between a pair of electrodes (lower electrode 772 and upper electrode 788). The EL layer 786 may be composed of multiple layers such as layer 4420, light-emitting layer 4411, and layer 4430. Layer 4420 may include, for example, a layer containing a substance with high electron injection capability (electron injection layer) and a layer containing a substance with high electron transport capability (electron transport layer). Light-emitting layer 4411 may, for example, contain a light-emitting compound. Layer 4430 may, for example, include a layer containing a substance with high hole injection capability (hole injection layer) and a layer containing a substance with high hole transport capability (hole transport layer).

[0277] The structure including layer 4420, light-emitting layer 4411 and layer 4430 disposed between a pair of electrodes can be used as a single light-emitting unit. In this specification, the structure of FIG20A is referred to as a single structure.

[0278] FIG20B shows a modified example of the EL layer 786 included in the light-emitting device shown in FIG20A. Specifically, the light-emitting device shown in FIG20B includes layer 4430-1 on the lower electrode 772, layer 4430-2 on layer 4430-1, light-emitting layer 4411 on layer 4430-2, layer 4420-1 on light-emitting layer 4411, layer 4420-2 on layer 4420-1, and upper electrode 788 on layer 4420-2. For example, when the lower electrode 772 is used as the anode and the upper electrode 788 is used as the cathode, layer 4430-1 is used as the hole injection layer, layer 4430-2 is used as the hole transport layer, layer 4420-1 is used as the electron transport layer, and layer 4420-2 is used as the electron injection layer. Alternatively, when the lower electrode 772 is used as the cathode and the upper electrode 788 is used as the anode, layer 4430-1 is used as the electron injection layer, layer 4430-2 is used as the electron transport layer, layer 4420-1 is used as the hole transport layer, and layer 4420-2 is used as the hole injection layer. By employing the above layer structure, carriers can be efficiently injected into the light-emitting layer 4411, thereby improving the recombination efficiency of carriers within the light-emitting layer 4411.

[0279] In addition, as shown in Figures 20C and 20D, the structure in which multiple light-emitting layers (light-emitting layers 4411, 4412, and 4413) are disposed between layer 4420 and layer 4430 is also a variant example of a single structure.

[0280] As shown in Figures 20E and 20F, the structure in which multiple light-emitting units (EL layers 786a and 786b) are connected in series with an intermediate layer (charge generation layer) 4440 is referred to as a series structure in this specification. While the structure shown in Figures 20E and 20F is referred to as a series structure in this specification, it is not limited thereto; for example, a series structure may also be referred to as a stacked structure. By employing a series structure, a light-emitting device capable of emitting light with high brightness can be realized.

[0281] In Figure 20C, light-emitting layers 4411, 4412 and 4413 that emit light of the same color can also be used.

[0282] Alternatively, different luminescent materials can be used for luminescent layers 4411, 4412, and 4413. When the light emitted by each of luminescent layer 4411, 4412, and 4413 is in a complementary color relationship, white light emission can be obtained. Figure 20D shows an example of a color layer 785 used as a color filter. By allowing white light to pass through the color filter, light of the desired color can be obtained.

[0283] Alternatively, in FIG20E, the same luminescent material can be used for luminescent layers 4411 and 4412. Alternatively, luminescent materials emitting different colors of light can be used for luminescent layers 4411 and 4412. When the light emitted by luminescent layer 4411 and the light emitted by luminescent layer 4412 are complementary colors, white light emission can be obtained. FIG20F shows an example where a color layer 785 is also provided.

[0284] Note that in Figures 20C, 20D, 20E and 20F, as shown in Figure 20B, layers 4420 and 4430 may also have a stacked structure consisting of two or more layers.

[0285] Furthermore, in Figure 20D, the light-emitting layers 4411, 4412, and 4413 can use the same light-emitting material. Similarly, in Figure 20F, the light-emitting layers 4411 and 4412 can also use the same light-emitting material. In this case, by using a color conversion layer instead of the color layer 785, light of a desired color different from the light-emitting material can be obtained. For example, by using a blue light-emitting material as each light-emitting layer and passing blue light through the color conversion layer, light with a wavelength longer than blue (e.g., red, green, etc.) can be obtained. The color conversion layer can use fluorescent materials, phosphorescent materials, or quantum dots, etc.

[0286] The structure in which light-emitting layers (blue (B), green (G) and red (R) are formed separately for each light-emitting device) is called an SBS (Side By Side) structure.

[0287] The emission color of the light-emitting device can be red, green, blue, cyan, magenta, yellow, or white, depending on the material constituting the EL layer 786. Furthermore, when the light-emitting device has a microcavity structure, the color purity can be further improved.

[0288] A white light-emitting device preferably has a structure in which the light-emitting layer contains two or more light-emitting materials. In order to obtain white light emission, two or more light-emitting materials whose light emission is in a complementary color relationship can be selected. For example, by making the light emission color of the first light-emitting layer and the light emission color of the second light-emitting layer complementary colors, a light-emitting device that emits white light throughout the light-emitting device can be obtained. Furthermore, the same applies to light-emitting devices that include three or more light-emitting layers.

[0289] Preferably, the luminescent layer comprises two or more luminescent materials, each emitting light in the form of R (red), G (green), B (blue), Y (yellow), O (orange), etc. Alternatively, it preferably comprises two or more luminescent materials, each emitting light in the form of two or more spectral components of R, G, and B.

[0290] Here, a specific structural example of a light-emitting device is described.

[0291] A light-emitting device includes at least a light-emitting layer. In addition, as a layer other than the light-emitting layer, the light-emitting device may also include a layer containing a material with high hole injection capacity, a material with high hole transport capacity, a hole blocking material, a material with high electron transport capacity, an electron blocking material, a material with high electron injection capacity, or a bipolar material (a material with high electron transport capacity and high hole transport capacity).

[0292] Light-emitting devices can use 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 vapor deposition), transfer printing, printing, inkjet printing, coating, etc.

[0293] For example, in addition to the light-emitting layer, the light-emitting device may also include one or more of the following: a hole injection layer, a hole transport layer, a hole barrier layer, an electron barrier layer, an electron transport layer, and an electron injection layer.

[0294] The hole injection layer is a layer that injects holes from the anode into the hole transport layer and contains a material with high hole injection capability. As a material with high hole injection capability, aromatic amine compounds, composite materials containing hole transport materials and acceptor materials (electron acceptor materials), etc. can be used.

[0295] The hole transport layer is a layer that transports holes injected from the anode through the hole injection layer to the light-emitting layer. The hole transport layer is a layer containing a hole-transporting material. As a hole-transporting material, it is preferable to use a material with a hole mobility of 1×10-6 cm² / Vs or higher. In addition, any material other than the above can be used as long as its hole transportability is higher than its electron transportability. As a hole transporting material, it is preferable to use materials with high hole transportability such as π-electron-rich heteroaromatic compounds (e.g., carbazole derivatives, thiophene derivatives, furan derivatives, etc.) or aromatic amines (compounds containing an aromatic amine skeleton).

[0296] 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 transport material. As an electron transport material, it is preferable to use a material with an electron mobility of 1×10-6 cm2 / Vs or higher. In addition, any material other than the above can be used as long as its electron transportability is higher than its hole transportability. As an electron transport material, metal complexes with a quinoline skeleton, metal complexes with a benzoquinoline skeleton, metal complexes with a chloroazole skeleton, metal complexes with a thiazole skeleton, etc., can be used. Materials with high electron transportability, such as chlorodiazole derivatives, triazole derivatives, imidazole derivatives, chloroazole derivatives, thiazole derivatives, phenobarbital derivatives, quinoline derivatives with quinoline ligands, benzoquinoline derivatives, quinoline derivatives, dibenzoquinoline derivatives, pyridine derivatives, bipyridine derivatives, pyrimidine derivatives, nitrogen-containing heteroaromatic compounds, and other π-electron-deficient heteroaromatic compounds, can also be used.

[0297] The electron injection layer is a layer containing a material with high electron injection capability, through which electrons are injected from the cathode into the electron transport layer. As a material with high electron injection capability, alkali metals, alkaline earth metals, or compounds containing the above substances can be used. As a material with high electron injection capability, a composite material containing an electron transport material and a donor material (electron donor material) can also be used.

[0298] As the electron injection layer, for example, lithium, cesium, ytterbium, lithium fluoride (LiF), cesium fluoride (CsF), calcium fluoride (CaF2), lithium 8-(hydroxyoxoline) (Liq), lithium 2-(2-pyridyl)phenol (LiPP), lithium 2-(2-pyridyl)-3-hydroxypyridinolato (LiPPy), lithium 4-phenyl-2-(2-pyridyl)phenol (LiPPP), lithium oxide (LiOx), cesium carbonate, and other alkali metals, alkaline earth metals, or compounds thereof can be used. Furthermore, the electron injection layer can be a stacked structure of two or more layers. For example, a structure in which lithium fluoride is used as the first layer and ytterbium as the second layer can be used.

[0299] Furthermore, materials with electron transport properties can also be used as the aforementioned electron injection layer. For example, compounds having non-shared electron pairs and electron-deficient heteroaromatic rings can be used as materials with electron transport properties. Specifically, compounds containing at least one of pyridine rings, diazine rings (pyrimidine rings, pyrazine rings, pyrazine rings), and triazine rings can be used.

[0300] The lowest unoccupied molecular orbital (LUMO) of organic compounds with non-shared electron pairs is preferably above -3.6 eV and below -2.3 eV. Furthermore, generally, cyclic voltammetry (CV), photoelectron spectroscopy, optical absorption spectroscopy, and inverse photoelectron spectroscopy are used to estimate the highest occupied molecular orbital (HOMO) and LUMO levels of organic compounds.

[0301] For example, 4,7-diphenyl-1,10-phenanthroline (abbreviated as BPhen), 2,9-bis(naphthyl-2-yl)-4,7-diphenyl-1,10-phenanthroline (abbreviated as NBPhen), diquinoline[2,3-a:2',3'-c]phenazine (abbreviated as HATNA), and 2,4,6-tris[3'-(pyridin-3-yl)biphenyl-3-yl]-1,3,5-triazine (abbreviated as TmPPPyTz) can be used in organic compounds with non-shared electron pairs. Furthermore, compared to BPhen, NBPhen has a higher glass transition temperature (Tg) and better heat resistance.

[0302] The luminescent layer is a layer containing a luminescent substance. The luminescent layer may contain one or more luminescent substances. In addition, substances that emit light in colors such as blue, purple, blue-violet, green, yellow-green, yellow, orange, and red are appropriately used as luminescent substances. Furthermore, substances that emit near-infrared light may also be used as luminescent substances.

[0303] As luminescent materials, examples include fluorescent materials, phosphorescent materials, TADF materials, quantum dot materials, etc.

[0304] As fluorescent materials, examples include pyrene derivatives, anthracene derivatives, triphenylene derivatives, fumonisin derivatives, carbazole derivatives, dibenzothiophene derivatives, dibenzofuran derivatives, dibenzoquinoline derivatives, quinoline derivatives, pyridine derivatives, pyrimidine derivatives, phenanthrene derivatives, naphthalene derivatives, etc.

[0305] As phosphorescent materials, examples include organometallic complexes (especially iridium complexes) having a 4H-triazole skeleton, a 1H-triazole skeleton, an imidazole skeleton, a pyrimidine skeleton, a pyrazine skeleton, or a pyridine skeleton, organometallic complexes (especially iridium complexes) with phenylpyridine derivatives having electron-withdrawing groups as ligands, platinum complexes, rare earth metal complexes, etc.

[0306] In addition to the luminescent material (guest material), the luminescent layer may also contain one or more organic compounds (host material, auxiliary material, etc.). As one or more organic compounds, one or both of hole transport materials and electron transport materials may be used. In addition, as one or more organic compounds, bipolar materials or TADF materials may also be used.

[0307] For example, the luminescent layer is preferably a combination of a phosphorescent material, a hole transport material that readily forms excited-state complexes, and an electron transport material. By employing such a structure, ExTET (Exciplex-Triplet Energy Transfer), which utilizes energy transfer from the excited-state complex to the luminescent material (phosphorescent material), can be efficiently obtained. By selecting a mixture of materials in a manner that forms excited-state complexes that emit light with wavelengths overlapping the absorption band on the lowest energy side of the luminescent material, energy transfer can be facilitated, thereby achieving efficient luminescence. This structure enables the simultaneous realization of high efficiency, low-voltage operation, and long lifetime in the luminescent device.

[0308] At least a portion of the structural examples shown in this embodiment and the corresponding diagrams can be appropriately combined with other structural examples or diagrams.

[0309] At least a portion of this embodiment may be implemented in combination with other embodiments described in this specification.

[0310] Embodiment 4 In this embodiment, an example of a display device according to an embodiment of the present invention, including a light-receiving device, will be described.

[0311] In the display device of this embodiment, a pixel may include multiple sub-pixels having light-emitting devices that emit light of different colors. For example, a pixel may include three types of sub-pixels. Examples of these three types of sub-pixels include sub-pixels of red (R), green (G), and blue (B), and sub-pixels of yellow (Y), cyan (C), and magenta (M). Alternatively, a pixel may include four types of sub-pixels. Examples of these four types of sub-pixels include sub-pixels of R, G, B, and white (W), and sub-pixels of R, G, B, and Y.

[0312] There are no particular restrictions on the arrangement of subpixels, and various arrangement methods can be used. Examples of subpixel arrangements include stripe arrangement, S-stripe arrangement, matrix arrangement, Delta arrangement, Bayer arrangement, Pentile arrangement, etc.

[0313] Furthermore, examples of the top surface shape of a sub-pixel include triangles, quadrilaterals (including rectangles and squares), pentagons, and other polygonal shapes with rounded corners, as well as ellipses or circles. Here, the top surface shape of the sub-pixel corresponds to the top surface shape of the light-emitting area of ​​the light-emitting device.

[0314] In a display device according to one embodiment of the present invention, the pixel may also include a light-receiving device.

[0315] In a display device where pixels include light-emitting devices and light-receiving devices, the pixels have a light-receiving function, so the display device can detect the contact or proximity of an object while displaying an image. For example, not only can all sub-pixels included in the display device display images, but some sub-pixels can emit light as a light source and other sub-pixels can display images.

[0316] In one embodiment of the display device of the present invention, the light-emitting devices are arranged in a matrix in the display section, thereby enabling the display of images. Furthermore, in this display section, the light-receiving devices are arranged in a matrix, and the display section, in addition to image display function, also has one or both of a camera function and a sensing function. The display section can be used as an image sensor or a touch sensor. That is, by detecting light from the display section, an image can be captured or the proximity or contact of an object (finger, hand, or pen, etc.) can be detected. Moreover, in one embodiment of the display device of the present invention, the light-emitting devices can be used as the light source for the sensor. Therefore, it is not necessary to separately provide a light-receiving section and a light source with the display device, thus reducing the number of components in the electronic device.

[0317] In a display device according to one embodiment of the present invention, when light emitted by a light-emitting device included in the display section is reflected (or scattered) by an object, a light-receiving device can detect the reflected light (or scattered light), thereby enabling the capture of images or the detection of touch even in the dark.

[0318] When the light-receiving device is used as an image sensor, the display device can use the light-receiving device to capture images. For example, the display device of this embodiment can be used as a scanner.

[0319] For example, an image sensor can be used to acquire data based on fingerprints, palm prints, etc. In other words, a biometric authentication sensor can be installed within the display device. By installing a biometric authentication sensor within the display device, compared to installing the display device and the biometric authentication sensor separately, the number of parts in the electronic device can be reduced, thereby enabling miniaturization and weight reduction of the electronic device.

[0320] Furthermore, when the light-receiving device is used as a touch sensor, the display device can use the light-receiving device to detect the approach or contact of an object.

[0321] As a light-receiving device, for example, a pn-type or pin-type photodiode can be used. The light-receiving device is used as a photoelectric conversion device (also called a photoelectric conversion element) that generates charge by detecting the light incident on the light-receiving device. The amount of charge generated by the light-receiving device depends on the amount of light incident on the light-receiving device.

[0322] In particular, as a light-receiving device, an organic photodiode having a layer containing an organic compound is preferred. Organic photodiodes are easy to make thin, lightweight and large-area, and have high flexibility in shape and design, thus they can be applied to a wide variety of display devices.

[0323] In one embodiment of the present invention, an organic EL device is used as a light-emitting device, and an organic photodiode is used as a light-receiving device. The organic EL device and the organic photodiode can be formed on the same substrate. Therefore, the organic photodiode can be installed in a display device using an organic EL device.

[0324] The pixels shown in Figures 21A, 21B and 21C include sub-pixels G, B, R and PS.

[0325] The pixels shown in Figure 21A are arranged in a stripe pattern. The pixels shown in Figure 21B are arranged in a matrix pattern.

[0326] The arrangement of pixels shown in Figure 21C adopts a structure in which three sub-pixels (sub-pixel R, sub-pixel G, and sub-pixel S) are arranged vertically next to one sub-pixel (sub-pixel B).

[0327] The pixels shown in Figure 21D include sub-pixels G, B, R, PS, and IRS.

[0328] Figure 21D shows an example of a pixel set in two rows. The upper row (first row) has three sub-pixels (sub-pixel G, sub-pixel B, and sub-pixel R), and the lower row (second row) has two sub-pixels (one sub-pixel PS and one sub-pixel IRS).

[0329] Note that the layout of subpixels is not limited to the structures shown in Figures 21A to 21D.

[0330] Sub-pixel R includes a light-emitting device that emits red light. Sub-pixel G includes a light-emitting device that emits green light. Sub-pixel B includes a light-emitting device that emits blue light. Sub-pixels PS and IRS each include a light-receiving device. There are no particular restrictions on the wavelength of the light detected by sub-pixels PS and IRS.

[0331] The light-receiving area of ​​the sub-pixel PS is smaller than that of the sub-pixel IRS. The smaller the light-receiving area, the narrower the imaging range, which can suppress blurring of the imaging result and improve resolution. Therefore, by using the sub-pixel PS, imaging can be performed with higher clarity or resolution compared to using the sub-pixel IRS. For example, the sub-pixel PS can be used for personal identification using fingerprints, palm prints, irises, vein shapes (including vein shapes and artery shapes), or faces.

[0332] The light-receiving device included in the sub-pixel PS preferably detects visible light, and more preferably detects one or more of the following colors: blue, purple, blue-violet, green, yellow-green, yellow, orange, and red. Additionally, the light-receiving device included in the sub-pixel PS can also detect infrared light.

[0333] Furthermore, sub-pixel IRS can be used in touch sensors (also known as direct touch sensors) or air touch sensors (also known as hover sensors, hover touch sensors, non-contact sensors, contactless sensors, etc.). The wavelength of the light detected by the sub-pixel IRS can be appropriately determined according to the application. For example, it is preferable for the sub-pixel IRS to detect infrared light. Thus, touch can be detected even in the dark.

[0334] Here, a touch sensor or an air touch sensor can detect the approach or contact of an object (finger, hand, or pen, etc.). The touch sensor can detect an object through direct contact between the display device and the object. Alternatively, an air touch sensor can detect an object even without direct contact. For example, preferably, the display device can detect the object within a distance of 0.1 mm to 300 mm, more preferably 3 mm to 50 mm, between the display device and the object. By employing this structure, operation can be performed without direct contact between the object and the display device; in other words, the display device can be operated in a non-contact (contactless) manner. By employing the above structure, the risk of the display device becoming dirty or damaged can be reduced, or the display device can be operated without direct contact with stains (e.g., garbage or viruses) adhering to it.

[0335] By setting two light-receiving devices in one pixel, two additional functions can be added in addition to the display function, thereby realizing the multi-functionality of the display device.

[0336] Because high-definition imaging is performed, it is preferable that the sub-pixels PS be placed in all the pixels included in the display device. On the other hand, compared to sub-pixels PS, sub-pixel IRS used for touch sensors or air touch sensors do not require high detection accuracy, so it is sufficient to place the sub-pixel IRS in only a portion of the pixels included in the display device. By making the number of sub-pixel IRS included in the display device less than the number of sub-pixels PS, the detection speed can be improved.

[0337] Here, the structure of the light-receiving device that can be used for sub-pixel PS and sub-pixel IRS is described.

[0338] The light-receiving device includes at least an active layer between a pair of electrodes, which serves as a photoelectric conversion layer. In this specification, etc., one of the pair of electrodes is sometimes referred to as the pixel electrode and the other as the common electrode.

[0339] One of the pair of electrodes included in the light-receiving device is used as an anode, and the other electrode is used as a cathode. Hereinafter, the case in which the pixel electrode is used as the anode and the common electrode is used as the cathode will be explained as an example. That is, by applying a reverse bias voltage between the pixel electrode and the common electrode to drive the light-receiving device, the light incident on the light-receiving device can be detected, a charge can be generated, and the charge can be extracted in the form of a current.

[0340] The light-receiving device can also be manufactured using the same method as the light-emitting device. The island-shaped active layer (also known as the photoelectric conversion layer) included in the light-receiving device is not formed by patterning a metal mask, but is formed by depositing a film that will become the active layer on one side and then processing it. Therefore, the island-shaped active layer can be formed with a uniform thickness. In addition, by providing a sacrificial layer on the active layer, damage to the active layer during the manufacturing process of the display device can be reduced, thereby improving the reliability of the light-receiving device.

[0341] Note that layers shared by the light-receiving and light-emitting devices sometimes have different functions in the light-emitting and light-receiving devices. In this specification, components are sometimes referred to according to their function in the light-emitting device. For example, a hole injection layer is used as a hole injection layer in the light-emitting device and as a hole transport layer in the light-receiving device. Similarly, an electron injection layer functions as both an electron injection layer and an electron transport layer in both the light-emitting and light-receiving devices. Furthermore, layers shared by the light-receiving and light-emitting devices sometimes have the same function in both the light-emitting and light-receiving devices. For example, a hole transport layer is used as a hole transport layer in both the light-emitting and light-receiving devices, and an electron transport layer is used as an electron transport layer in both the light-emitting and light-receiving devices.

[0342] The active layer of the light-receiving device includes a semiconductor. Examples of such semiconductors include inorganic semiconductors such as silicon and organic semiconductors containing organic compounds. In this embodiment, an example of using an organic semiconductor as the semiconductor contained in the active layer is shown. By using an organic semiconductor, the light-emitting layer and the active layer can be formed in the same way (e.g., vacuum evaporation) and can share the same manufacturing equipment, which is preferable.

[0343] Examples of electron-accepting organic semiconductor materials include fullerenes (e.g., C60, C70, etc.) and fullerene derivatives, which are n-type semiconductors contained in the active layer. Fullerenes have a soccer ball shape, which is energy stable. Fullerenes have deep (low) HOMO and LUMO energy levels. Because of the deep LUMO energy level of fullerenes, their electron acceptor behavior is extremely high. Generally, when π-electron conjugation (resonance) expands in a plane, such as in benzene, electron donor behavior becomes high. On the other hand, fullerenes have a spherical shape, and although π-electrons expand extensively, their electron acceptor behavior is high. With high electron acceptor behavior, charge separation is induced quickly and efficiently, which is beneficial for light-receiving devices. C60 and C70 both have broad absorption bands in the visible light region, especially C70, which has a larger π-electron conjugation class than C60 and also has a broad absorption band in the long wavelength region, so it is preferred. In addition, examples of fullerene derivatives include methyl [6,6]-phenyl-C71-butyrate (abbreviated as PC71BM), methyl [6,6]-phenyl-C61-butyrate (abbreviated as PC61BM), and 1',1'',4',4''-tetrahydro-bis[1,4]methanenaphthaleno [1,2:2',3',56,60:2'',3''][5,6]fullerene-C60 (abbreviated as ICBA).

[0344] As materials for n-type semiconductors, examples include metal complexes with a quinoline skeleton, metal complexes with a benzoquinoline skeleton, metal complexes with a benzoxazole skeleton, metal complexes with a thiazole skeleton, benzodiazepine derivatives, triazole derivatives, imidazole derivatives, benzoxazole derivatives, thiazole derivatives, phenoline derivatives, quinoline derivatives, benzoquinoline derivatives, quinoline derivatives, dibenzoquinoline derivatives, pyridine derivatives, bipyridine derivatives, pyrimidine derivatives, naphthalene derivatives, anthracene derivatives, coumarin derivatives, rhodamine derivatives, triazine derivatives, quinone derivatives, etc.

[0345] As materials for p-type semiconductors contained in the active layer, examples of organic semiconductor materials with electronic donor properties include copper(II) phthalocyanine (CuPc), tetraphenyldibenzoperiflanthene (DBP), zinc phthalocyanine (ZnPc), tin phthalocyanine (SnPc), and quinacridone.

[0346] In addition, examples of materials for p-type semiconductors include carbazole derivatives, thiophene derivatives, furan derivatives, and compounds having an aromatic amine skeleton. Furthermore, examples of materials for p-type semiconductors include naphthalene derivatives, anthracene derivatives, pyrene derivatives, triphenylene derivatives, benzo[a]furan derivatives, benzo[a]thiophene derivatives, indole derivatives, dibenzo[a]furan derivatives, dibenzo[a]thiophene derivatives, indole-carbazole derivatives, violet derivatives, phthalocyanine derivatives, naphthylphthalocyanine derivatives, quinacridone derivatives, polyphenylene oxide derivatives, poly[a]benzene oxide derivatives, poly[a]benzene oxide derivatives, poly[a]benzene oxide derivatives, polyvinylcarbazole derivatives, or polythiophene derivatives.

[0347] The HOMO energy level of an organic semiconductor material with electron donor properties is preferably shallower (higher) than that of an organic semiconductor material with electron acceptor properties. The LUMO energy level of an organic semiconductor material with electron donor properties is preferably shallower (higher) than that of an organic semiconductor material with electron acceptor properties.

[0348] Preferably, spherical fullerenes are used as organic semiconductor materials with electron-accepting properties, and more preferably, organic semiconductor materials with shapes similar to planar structures are used as organic semiconductor materials with electron-donating properties. Molecules with similar shapes tend to aggregate easily. When the same type of molecule aggregates, the carrier transport can be improved because the energy levels of the molecular orbitals are similar.

[0349] For example, it is preferable to co-deposit an n-type semiconductor and a p-type semiconductor to form the active layer. Alternatively, an n-type semiconductor and a p-type semiconductor may be stacked to form the active layer.

[0350] The light-receiving device may also include layers other than the active layer, such as layers containing materials with high hole transport, materials with high electron transport, or bipolar materials (materials with both high electron and hole transport). In addition, it is not limited to this, but may also include layers containing materials with high hole injection, hole blocking materials, materials with high electron injection, electron blocking materials, etc.

[0351] The light-receiving device may use low-molecular-weight compounds or high-molecular-weight compounds, and may also contain inorganic compounds. The layers constituting the light-receiving device may be formed by methods such as vapor deposition (including vacuum vapor deposition), transfer printing, printing, inkjet printing, coating, etc.

[0352] For example, polymeric compounds such as poly(3,4-ethylenedioxythiophene) / poly(styrene sulfonic acid) (PEDOT / PSS) and inorganic compounds such as molybdenum oxide and copper iodide (CuI) can be used as hole transport materials. In addition, inorganic compounds such as zinc oxide (ZnO) can be used as electron transport materials.

[0353] In addition, the active layer may also use a polymer such as poly[[4,8-bis[5-(2-ethylhexyl)-2-thiophene]benzo[1,2-b:4,5-b']dithienyl-2,6-diyl]-2,5-thiophenediyl[5,7-bis(2-ethylhexyl)-4,8-dioxo-4H,8H-benzo[1,2-c:4,5-c']dithienyl-1,3-diyl]] (abbreviated as PBDB-T) or a PBDB-T derivative thereof, which serves as the donor. For example, methods such as dispersing the acceptor material into PBDB-T or a PBDB-T derivative may be used.

[0354] In addition, three or more materials can be mixed as the active layer. For example, in order to expand the wavelength region, a third material can be mixed in addition to the n-type semiconductor material and the p-type semiconductor material. In this case, the third material can be a low-molecular-weight compound or a high-molecular-weight compound.

[0355] The above describes the light-receiving device.

[0356] Figure 21E shows an example of a sub-pixel with a light-receiving device, while Figure 21F shows an example of a sub-pixel with a light-emitting device.

[0357] The pixel circuit PIX1 shown in Figure 21E includes a light-receiving device PD, transistors M11, M12, M13, and M14, and a capacitor C2. Here, an example is shown using a photodiode as the light-receiving device PD.

[0358] The cathode of the light-receiving device PD is electrically connected to wiring V1, and the anode is electrically connected to one of the source and drain electrodes of transistor M11. The gate of transistor M11 is electrically connected to wiring TX, and the other of its source and drain electrodes is electrically connected to one electrode of capacitor C2, one of the source and drain electrodes of transistor M12, and the gate of transistor M13. The gate of transistor M12 is electrically connected to wiring RES, and the other of its source and drain electrodes is electrically connected to wiring V2. One of the source and drain electrodes of transistor M13 is electrically connected to wiring V3, and the other of its source and drain electrodes is electrically connected to one of the source and drain electrodes of transistor M14. The gate of transistor M14 is electrically connected to wiring SE, and the other of its source and drain electrodes is electrically connected to wiring OUT1.

[0359] Wiring V1, wiring V2, and wiring V3 are each supplied with a constant potential. When the photodetector PD is driven with a reverse bias, a potential lower than that of wiring V1 is supplied to wiring V2. Transistor M12 is controlled by a signal supplied to wiring RES, causing the potential of the node connected to the gate of transistor M13 to be reset to the potential supplied to wiring V2. Transistor M11 is controlled by a signal supplied to wiring TX, controlling the timing of the potential changes of the aforementioned nodes according to the current flowing through the photodetector PD. Transistor M13 is used as an amplifying transistor for outputting the potential of the aforementioned nodes. Transistor M14 is controlled by a signal supplied to wiring SE, and is used as a selection transistor, which is used to read the output based on the potential of the aforementioned nodes using an external circuit connected to wiring OUT1.

[0360] The pixel circuit PIX2 shown in Figure 21F includes a light-emitting device EL, transistors M15, M16, and M17, and a capacitor C3. Here, an example of using a light-emitting diode as the light-emitting device EL is shown. In particular, an organic EL device is preferred as the light-emitting device EL.

[0361] The gate of transistor M15 is electrically connected to wiring VG, one of its source and drain is electrically connected to wiring VS, and the other of its source and drain is electrically connected to one electrode of capacitor C3 and the gate of transistor M16. One of the source and drain of transistor M16 is electrically connected to wiring V4, and the other of its source and drain is electrically connected to the anode of light-emitting device EL and one of the source and drain of transistor M17. The gate of transistor M17 is electrically connected to wiring MS, and the other of its source and drain is electrically connected to wiring OUT2. The cathode of light-emitting device EL is electrically connected to wiring V5.

[0362] Wiring V4 and wiring V5 are each supplied with a constant potential. The anode side and cathode side of the light-emitting device EL can be set to a high potential and a potential lower than that of the anode side, respectively. Transistor M15 is controlled by a signal supplied to wiring VG and is used as a selection transistor to control the selection state of the pixel circuit PIX2. In addition, transistor M16 is used as a drive transistor to control the current flowing through the light-emitting device EL according to the potential supplied to its gate. When transistor M15 is in the on state, the potential supplied to wiring VS is supplied to the gate of transistor M16, and the brightness of the light-emitting device EL can be controlled according to this potential. Transistor M17 is controlled by a signal supplied to wiring MS and outputs the potential between transistor M16 and the light-emitting device EL to the outside through wiring OUT2.

[0363] In the display panel of this embodiment, the light-emitting device can also emit light in a pulsed manner to display images. By shortening the driving time of the light-emitting device, the power consumption of the display panel can be reduced and heat generation can be suppressed. In particular, organic EL devices have excellent frequency characteristics, so they are preferred. For example, the frequency can be 1kHz or higher and 100MHz or lower.

[0364] Here, the transistors M11, M12, M13 and M14 included in the pixel circuit PIX1, and the transistors M15, M16 and M17 included in the pixel circuit PIX2 are preferably transistors whose semiconductor layer forming their channels comprises metal oxide (oxide semiconductor).

[0365] Extremely low off-state currents can be achieved using metal oxide transistors with wider band gaps and lower carrier densities than silicon. Therefore, because of their small off-state currents, the charge stored in the capacitor connected in series with the transistor can be maintained for a long period. Therefore, in particular, transistors M11, M12, and M15 connected in series with capacitor C2 or capacitor C3 are preferably transistors containing oxide semiconductors. Furthermore, by using transistors that similarly utilize oxide semiconductors in other transistors, manufacturing costs can be reduced.

[0366] Furthermore, transistors M11 to M17 may also be transistors whose semiconductor forming their channels comprises silicon. In particular, it is preferable to use highly crystalline silicon such as monocrystalline silicon and polycrystalline silicon, which can achieve high field-efficiency mobility and higher operating speed.

[0367] In addition, one or more of transistors M11 to M17 may be transistors containing oxide semiconductors, and the other transistors may be transistors containing silicon.

[0368] In Figures 21E and 21F, an n-channel transistor is used as the transistor, but a p-channel transistor can also be used.

[0369] The transistors included in pixel circuit PIX1 and pixel circuit PIX2 are preferably arranged on the same substrate. More preferably, the transistors included in pixel circuit PIX1 and pixel circuit PIX2 are mixed and formed in one region and arranged periodically.

[0370] Furthermore, it is preferable to provide one or more layers, including one or both of transistors and capacitors, at a position overlapping with the light-receiving device PD or the light-emitting device EL. This reduces the effective area occupied by each pixel circuit, thereby enabling a high-definition light-receiving or display section.

[0371] As described above, the display device of this embodiment, by providing two light-receiving devices in a single pixel, can add two functions in addition to the display function, thereby realizing the multi-functionality of the display device. For example, it can realize high-definition camera function and sensing function such as touch sensor or air touch sensor. In addition, by combining pixels that provide two light-receiving devices with pixels having other structures, the functionality of the display device can be further increased. For example, pixels including light-emitting devices that emit infrared light or various sensor devices can be used.

[0372] Embodiment 5 In this embodiment, a metal oxide (also called an oxide semiconductor) that can be used in the OS transistor described in the above embodiments is explained.

[0373] The metal oxide used for the OS transistor preferably contains at least indium or zinc, more preferably indium and zinc. For example, the metal oxide preferably contains indium, M (M is selected from one or more of gallium, aluminum, yttrium, tin, silicon, boron, copper, vanadium, beryllium, titanium, iron, nickel, germanium, zirconium, molybdenum, lanthanum, cerium, neodymium, hafnium, tantalum, tungsten, magnesium and cobalt) and zinc. In particular, M is preferably selected from one or more of gallium, aluminum, yttrium and tin, more preferably gallium.

[0374] Metal oxides can be formed by sputtering, chemical vapor deposition (CVD) such as metal organic chemical vapor deposition (MOCVD), or atomic layer deposition (ALD).

[0375] Hereinafter, as an example of a metal oxide, an oxide containing indium (In), gallium (Ga), and zinc (Zn) will be described. Note that oxides containing indium (In), gallium (Ga), and zinc (Zn) are sometimes referred to as In-Ga-Zn oxides.

[0376] <<Classification of Crystal Structures>> As for the crystal structures of oxide semiconductors, examples include amorphous (including completely amorphous), CAAC (c-axis-aligned crystalline), nc (nanocrystalline), CAC (cloud-aligned composite), single crystal, and polycrystalline.

[0377] The crystal structure of a film or substrate can be evaluated using X-ray diffraction (XRD) spectroscopy. For example, the XRD spectrum obtained by GIXD (Grazing-Incidence XRD) can be used for evaluation. Furthermore, the GIXD method is also called the thin film method or the Seemann-Bohlin method. Hereinafter, the XRD spectrum obtained by GIXD measurement is sometimes simply referred to as the XRD spectrum.

[0378] For example, the peak shapes of the XRD spectrum of a quartz glass substrate are generally symmetrical. On the other hand, the peak shapes of the XRD spectrum of an In-Ga-Zn oxide film with a crystalline structure are not symmetrical. The asymmetry of the XRD peak shapes indicates the presence of crystals in the film or substrate. In other words, unless the XRD peak shapes are symmetrical, it cannot be said that the film or substrate is in an amorphous state.

[0379] Furthermore, the crystal structure of the film or substrate can be evaluated using diffraction patterns observed by nano-beam electron diffraction (NBED). For example, the observation of a halo pattern in the diffraction pattern of a quartz glass substrate confirms that the quartz glass is in an amorphous state. In contrast, a spot-like pattern was observed in the diffraction pattern of an In-Ga-Zn oxide film formed at room temperature, but no halo was observed. Therefore, it can be inferred that the In-Ga-Zn oxide film formed at room temperature is in an intermediate state that is neither monocrystalline nor polycrystalline nor amorphous, and it cannot be concluded that the In-Ga-Zn oxide film is amorphous.

[0380] <<Structure of Oxide Semiconductors>> Furthermore, when focusing on the structure of oxide semiconductors, the classification of oxide semiconductors sometimes differs from the above classification. For example, oxide semiconductors can be classified into single-crystal oxide semiconductors and other non-single-crystal oxide semiconductors. Examples of non-single-crystal oxide semiconductors include, for example, the aforementioned CAAC-OS and nc-OS. Furthermore, non-single-crystal oxide semiconductors include polycrystalline oxide semiconductors, a-like OS (amorphous-like oxide semiconductor), and amorphous oxide semiconductors, etc.

[0381] Here, the details of CAAC-OS, nc-OS and a-like OS mentioned above will be explained.

[0382] [CAAC-OS] CAAC-OS is an oxide semiconductor comprising multiple crystalline regions whose c-axis is aligned in a specific direction. Furthermore, the specific direction refers to the thickness direction of the CAAC-OS film, the normal direction of the formed surface of the CAAC-OS film, or the normal direction of the surface of the CAAC-OS film. Additionally, the crystalline region is a region with a periodic atomic arrangement. Note that when the atomic arrangement is considered as a lattice arrangement, the crystalline region is also a region with a consistent lattice arrangement. Moreover, CAAC-OS has a region where multiple crystalline regions are connected in the ab-plane direction, and sometimes this region exhibits distortion. Furthermore, distortion refers to the portion of the lattice arrangement direction that changes between regions with consistent lattice arrangement and other regions with consistent lattice arrangement in the region where multiple crystalline regions are connected. In other words, CAAC-OS refers to an oxide semiconductor with c-axis alignment but no obvious alignment in the ab-plane direction.

[0383] Furthermore, each of the aforementioned multiple crystalline regions is composed of one or more microcrystals (crystals with a maximum diameter of less than 10 nm). When a crystalline region is composed of a single microcrystal, the maximum diameter of that crystalline region is less than 10 nm. Furthermore, when a crystalline region is composed of multiple microcrystals, the size of that crystalline region is sometimes around tens of nm.

[0384] Furthermore, in In-Ga-Zn oxides, CAAC-OS tends to have a layered crystal structure (also called a layered structure) consisting of layers containing indium (In) and oxygen (hereinafter, In layer), and layers containing gallium (Ga), zinc (Zn), and oxygen (hereinafter, (Ga,Zn) layer). In addition, indium and gallium can substitute for each other. Therefore, sometimes the (Ga,Zn) layer contains indium. Furthermore, sometimes the In layer contains gallium. Note that sometimes the In layer contains zinc. This layered structure is observed, for example, as a lattice image in high-resolution TEM (Transmission Electron Microscope) images.

[0385] For example, when performing structural analysis on a CAAC-OS film using an XRD apparatus, in out-of-plane XRD measurements using θ / 2θ scanning, a peak representing c-axis alignment is detected at or near 2θ = 31°. Note that the position (2θ value) of the peak representing c-axis alignment sometimes varies depending on the type and composition of the metallic elements constituting CAAC-OS.

[0386] Furthermore, for example, multiple bright spots (spots) were observed in the electron diffraction pattern of the CAAC-OS film. In addition, when the spot of the incident electron beam that passes through the sample (also known as the direct spot) is taken as the center of symmetry, one spot and other spots are observed at point-symmetrical positions.

[0387] When observing the crystalline region from the aforementioned specific direction, although the lattice arrangement in the crystalline region is basically hexagonal, the unit lattice is not limited to a regular hexagon; there are cases where it is non-regular hexagonal. Furthermore, in the aforementioned distortions, pentagonal, heptagonal, and other lattice arrangements are sometimes present. Moreover, no clear grain boundary is observed near the distortion of CAAC-OS. That is, the distortion of the lattice arrangement inhibits the formation of grain boundaries. This may be because CAAC-OS can contain the distortion due to the low density of oxygen atoms in the ab-plane direction or the change in the bonding distance between atoms caused by the substitution of metal atoms.

[0388] Furthermore, a crystalline structure with clearly defined grain boundaries is called a polycrystalline structure. Grain boundaries become recombination centers where carriers are trapped, potentially leading to a decrease in the transistor's on-state current and field-effect mobility. Therefore, CAAC-OS, which lacks clearly defined grain boundaries, is one of the crystalline oxides that provides an excellent crystalline structure for the semiconductor layer of the transistor. Note that a structure containing Zn is preferred for constructing CAAC-OS. For example, In-Zn oxides and In-Ga-Zn oxides are preferred because they can further suppress grain boundary formation compared to In oxides.

[0389] CAAC-OS is an oxide semiconductor with high crystallinity and no clearly defined grain boundaries. Therefore, it can be said that in CAAC-OS, the decrease in electron mobility due to grain boundaries is less likely to occur. Furthermore, the crystallinity of oxide semiconductors can sometimes decrease due to the incorporation of impurities or the formation of defects; therefore, CAAC-OS can be considered an oxide semiconductor with few impurities and defects (such as oxygen vacancies). Therefore, oxide semiconductors containing CAAC-OS have stable physical properties. Thus, oxide semiconductors containing CAAC-OS exhibit high heat resistance and high reliability. In addition, CAAC-OS is also stable against high temperatures (so-called thermal budget) in the manufacturing process. Therefore, by using CAAC-OS in OS transistors, the flexibility of the manufacturing process can be expanded.

[0390] [nc-OS] In nc-OS, the atomic arrangement in tiny regions (e.g., regions larger than 1 nm and smaller than 10 nm, particularly regions larger than 1 nm and smaller than 3 nm) exhibits periodicity. In other words, nc-OS possesses tiny crystals. Furthermore, for example, these tiny crystals are sized between 1 nm and 10 nm, particularly between 1 nm and 3 nm, and are referred to as nanocrystals. Moreover, no regularity in crystal orientation is observed between different nanocrystals in nc-OS. Therefore, no alignment is observed in the overall film. Thus, sometimes nc-OS is indistinguishable from a-like OS or amorphous oxide semiconductors in certain analytical methods. For example, when performing structural analysis on nc-OS films using an XRD apparatus, no peaks indicating crystallinity are detected in out-of-plane XRD measurements using θ / 2θ scanning. Furthermore, when performing electron diffraction (also known as selected area electron diffraction) on nc-OS films using an electron beam with a beam diameter larger than that of nanocrystals (e.g., larger than 50 nm), a diffraction pattern resembling a halo pattern is observed. On the other hand, when electron diffraction (also known as nano-beam electron diffraction) is performed on nc-OS films using an electron beam whose beam diameter is close to or smaller than the size of nanocrystals (e.g., above 1 nm and below 30 nm), electron diffraction patterns of multiple spots are sometimes observed in an annular region centered on a direct spot.

[0391] [a-like OS] a-like OS is an oxide semiconductor with a structure intermediate between nc-OS and amorphous oxide semiconductors. a-like OS contains voids or low-density regions. That is, the crystallinity of a-like OS is lower than that of nc-OS and CAAC-OS. In addition, the hydrogen concentration in the film of a-like OS is higher than that in the films of nc-OS and CAAC-OS.

[0392] <<Structure of Oxide Semiconductors>> Next, the details of the above-mentioned CAC-OS will be explained. In addition, CAC-OS is related to the material composition.

[0393] [CAC-OS] CAC-OS refers, for example, to a composition in which elements contained in a metal oxide are unevenly distributed, wherein the size of the material containing the unevenly distributed elements is 0.5 nm or more and 10 nm or less, preferably 1 nm or more and 3 nm or approximately. Note that, below, the state in which one or more metal elements are unevenly distributed in a metal oxide and the regions containing those metal elements are mixed is also referred to as mosaic or patch-like, wherein the size of the region is 0.5 nm or more and 10 nm or less, preferably 1 nm or more and 3 nm or approximately.

[0394] Furthermore, CAC-OS refers to a structure in which the material is separated into a first region and a second region, forming a mosaic-like structure, and the first region is distributed in the film (hereinafter also referred to as cloud-like). That is to say, CAC-OS refers to a composite metal oxide having a structure in which the first region and the second region are mixed.

[0395] Here, each of the atomic ratios of In, Ga, and Zn relative to the metal elements constituting the CAC-OS of the In-Ga-Zn oxide is denoted as [In], [Ga], and [Zn]. For example, in the CAC-OS of the In-Ga-Zn oxide, a first region is a region where [In] is greater than [In] in the composition of the CAC-OS film. Furthermore, a second region is a region where [Ga] is greater than [Ga] in the composition of the CAC-OS film. Additionally, for example, a first region is a region where [In] is greater than [In] in the second region and [Ga] is less than [Ga] in the second region. Furthermore, a second region is a region where [Ga] is greater than [Ga] in the first region and [In] is less than [In] in the first region.

[0396] Specifically, the first region described above is a region whose main component is indium oxide or indium zinc oxide. Furthermore, the second region described above is a region whose main component is gallium oxide or gallium zinc oxide. In other words, the first region described above can be referred to as a region whose main component is In. Furthermore, the second region described above can be referred to as a region whose main component is Ga.

[0397] Note that sometimes the clear boundary between the first region and the second region mentioned above cannot be observed.

[0398] Furthermore, CAC-OS in In-Ga-Zn oxides refers to the following composition: in a material composition containing In, Ga, Zn, and O, regions with Ga as the main component and regions with In as the main component exist irregularly in a mosaic pattern. Therefore, it can be inferred that CAC-OS has a structure with uneven distribution of metal elements.

[0399] CAC-OS can be formed, for example, by sputtering without intentionally heating the substrate. When forming CAC-OS by sputtering, one or more gases selected from inert gases (typically argon), oxygen gases, and nitrogen gases can be used as the deposition gas. Furthermore, the lower the oxygen gas flow rate in the total flow rate of the deposition gas during deposition, the better. For example, the oxygen gas flow rate in the total flow rate of the deposition gas during deposition should be 0% or more and less than 30%, preferably 0% or more and less than 10%.

[0400] For example, in the CAC-OS of In-Ga-Zn oxide, based on the EDX-mapping image obtained by Energy Dispersive X-ray spectroscopy (EDX), a structure with a non-uniformly distributed mixture of regions with In as the main component (first region) and regions with Ga as the main component (second region) can be identified.

[0401] Here, the first region is a region with higher conductivity than the second region. That is, when carriers flow through the first region, it exhibits conductivity as a metal oxide. Therefore, when the first region is distributed in a cloud-like manner in the metal oxide, a high field mobility (μ) can be achieved.

[0402] On the other hand, the second region is a region with higher insulation than the first region. That is, when the second region is distributed in the metal oxide, leakage current can be suppressed.

[0403] When CAC-OS is used in a transistor, the complementary effect of conductivity arising from the first region and insulation arising from the second region enables CAC-OS to have a switching function (the function of controlling on / off). In other words, CAC-OS has a conductive function in one part of the material and an insulating function in another part, and a semiconductor function in the material as a whole. By separating the conductive and insulating functions, each function can be maximized. Therefore, by using CAC-OS in a transistor, a large on-state current (Ion), high field-effect mobility (μ), and good switching operation can be achieved.

[0404] Furthermore, transistors using CAC-OS exhibit high reliability. Therefore, CAC-OS is best suited for various semiconductor devices such as display devices.

[0405] Oxide semiconductors have various structures and properties. In one embodiment of the present invention, the oxide semiconductor may also include two or more of amorphous oxide semiconductors, polycrystalline oxide semiconductors, a-like OS, CAC-OS, nc-OS, and CAAC-OS.

[0406] <<Transistor with oxide semiconductor>> Next, we will explain the case of using the above-mentioned oxide semiconductor as a transistor.

[0407] By using the above-mentioned oxide semiconductor in transistors, transistors with high field-effect mobility can be realized. In addition, transistors with high reliability can be realized.

[0408] Preferably, an oxide semiconductor with a low carrier concentration is used as a transistor. For example, the carrier concentration in the oxide semiconductor is 1×10¹⁷ cm⁻³ or less, preferably 1×10¹⁵ cm⁻³ or less, more preferably 1×10¹³ cm⁻³ or less, further preferably 1×10¹¹ cm⁻³ or less, and even more preferably less than 1×10¹⁰ cm⁻³ and more than 1×10⁻⁹ cm⁻³. When the purpose is to reduce the carrier concentration of the oxide semiconductor film, the impurity concentration in the oxide semiconductor film can be reduced to reduce the defect state density. In this specification, the state of low impurity concentration and low defect state density is referred to as high purity or substantially high purity. Furthermore, an oxide semiconductor with a low carrier concentration is sometimes referred to as a high purity or substantially high purity oxide semiconductor.

[0409] Because oxide semiconductor films of high purity or essentially high purity have a low defect state density, they may have a low trap state density.

[0410] Furthermore, the charge trapped in the trap state of the oxide semiconductor takes a long time to disappear, and sometimes it acts like a fixed charge. Therefore, the electrical properties of the transistor that forms the channel formation region in the oxide semiconductor with a high trap state density are sometimes unstable.

[0411] Therefore, in order to stabilize the electrical properties of the transistor, it is effective to reduce the impurity concentration in the oxide semiconductor. To further reduce the impurity concentration in the oxide semiconductor, it is preferable to also reduce the impurity concentration in the adjacent film. Examples of impurities include hydrogen, nitrogen, alkali metals, alkaline earth metals, iron, nickel, and silicon. Note that impurities in an oxide semiconductor refer, for example, to elements other than the main components constituting the oxide semiconductor. For example, elements with a concentration less than 0.1 atomic% can be considered impurities.

[0412] <<Impurities>> Here, we explain the effects of various impurities in oxide semiconductors.

[0413] When the oxide semiconductor contains silicon or carbon, one of the elements in group 14, defect states are formed in the oxide semiconductor. Therefore, the concentration of silicon or carbon in the oxide semiconductor or near the interface with the oxide semiconductor (the concentration measured by secondary ion mass spectrometry (SIMS)) is set to 2×10¹⁸ atoms / cm³ or less, preferably 2×10¹⁷ atoms / cm³ or less.

[0414] Furthermore, when an oxide semiconductor contains an alkali metal or an alkaline earth metal, defect states are sometimes formed, thus creating carriers. Therefore, transistors using oxide semiconductors containing alkali metals or alkaline earth metals tend to have always-on characteristics. Therefore, the concentration of alkali metals or alkaline earth metals in the oxide semiconductor, as measured by SIMS, is preferably 1 × 10¹⁸ atoms / cm³ or less, and more preferably 2 × 10¹⁶ atoms / cm³ or less.

[0415] When an oxide semiconductor contains nitrogen, electrons are readily generated as carriers, increasing the carrier concentration and resulting in n-type characteristics. As a result, transistors using nitrogen-containing oxide semiconductors tend to have always-on characteristics. Alternatively, when an oxide semiconductor contains nitrogen, trapped states may sometimes form. Consequently, the electrical properties of the transistor may sometimes be unstable. Therefore, the nitrogen concentration in the oxide semiconductor, as measured by SIMS, is set to be below 5 × 10¹⁹ atoms / cm³, preferably below 5 × 10¹⁸ atoms / cm³, more preferably below 1 × 10¹⁸ atoms / cm³, and even more preferably below 5 × 10¹⁷ atoms / cm³.

[0416] Hydrogen contained in an oxide semiconductor reacts with oxygen bonded to a metal atom to form water, thus sometimes creating oxygen vacancies. When hydrogen enters this oxygen vacancy, electrons as carriers are sometimes generated. Furthermore, sometimes a portion of the hydrogen bonds with oxygen bonded to a metal atom, generating electrons as carriers. Therefore, transistors using oxide semiconductors containing hydrogen tend to have always-on characteristics. Thus, it is preferable to minimize the amount of hydrogen in the oxide semiconductor. Specifically, the hydrogen concentration in the oxide semiconductor, as measured by SIMS, is set to be less than 1 × 10²⁰ atoms / cm³, preferably less than 1 × 10¹⁹ atoms / cm³, more preferably less than 5 × 10¹⁸ atoms / cm³, and even more preferably less than 1 × 10¹⁸ atoms / cm³.

[0417] By using oxide semiconductors with sufficiently reduced impurities in the channel formation region of the transistor, the transistor can have stable electrical characteristics.

[0418] At least a portion of this embodiment may be implemented in combination with other embodiments described in this specification.

[0419] Embodiment 6 In this embodiment, an electronic device, digital signage, vehicle, etc., having a display device according to one embodiment of the present invention will be described.

[0420] One embodiment of the display device of the present invention is a display device capable of displaying an image overlay with a background, that is, a so-called display device capable of perspective display. Furthermore, the display device is capable of displaying high brightness, high resolution, high contrast, and high clarity, while also being low power consumption and highly reliable.

[0421] As an embodiment of the present invention, the display device may include, in addition to electronic devices with large screens such as televisions, desktop or laptop personal computers, monitors for computers, digital signage, pinball machines and other large game machines, digital cameras, digital video cameras, digital photo frames, mobile phones, portable game consoles, portable information terminals, audio playback devices and the like.

[0422] Furthermore, since the display device of one embodiment of the present invention can improve clarity, it can be appropriately used in electronic devices that include a small display section. Examples of such electronic devices include information terminal devices (wearable devices) such as watch-type and bracelet-type devices, VR devices such as head-mounted displays, and AR devices such as glasses-type displays. In addition, SR (Substitutional Reality) devices and MR (Mixed Reality) devices can also be cited as wearable devices.

[0423] In addition, the display device of this embodiment or the electronic device equipped with the display device can be assembled along the curved surface of the inner or outer wall of a house or high-rise building, or the interior or exterior decoration of a car.

[0424] In particular, since the display device of one embodiment of the present invention is capable of transparent display, it can be installed in a transparent structure such as window glass, display case, glass door or shop window, or the structure can be replaced with the display device.

[0425] FIG22A is an example of using a display device according to an embodiment of the present invention in a product display case. FIG22A shows a display section 1001 having the function of displaying images in a window. The display section 1001 employs a display device according to an embodiment of the present invention. The display section 1001 has a space inside, displaying product 1002 (here, a wristwatch), which customers can see through the display section 1001.

[0426] The display unit 1001 can display still images and moving images. In addition, it may also have a speaker that emits sound. In Figure 22A, an image containing the text "New Watch Debut!" is displayed as a promotional message for a new product.

[0427] Furthermore, the display unit 1001 is preferably used as a touch panel or a contactless touch panel. By operating the display unit 1001, customers can display detailed information, product lineup, and related information about the product 1002 on the display unit 1001. In Figure 22A, the touch display shows a "Touch Here!" section, which can, for example, display audio-visual promotional videos about the product.

[0428] Furthermore, customers can use their smartphones or similar devices to read the QR code displayed on the display unit 1001 to access the product's purchase website. In this way, customers can purchase products through simple operations.

[0429] The display unit 1001 is preferably made of glass that is not easily broken, such as tempered glass or bulletproof glass. Alternatively, a structure in which the display device is attached to the glass may be adopted. This can prevent the product 1002 from being stolen.

[0430] FIG22B shows an example of using a display device according to an embodiment of the present invention in a water tank. The water tank shown in FIG22B includes a cylindrical display section 1011 capable of displaying images. The display section 1011 employs a display device according to an embodiment of the present invention. The water tank is inside the display section 1011, and customers 1013a, 1013b, etc. can see the fish 1012 through the display section 1011.

[0431] The display unit 1011 can display information such as information related to the fish seen by the customer. In Figure 22B, an example is shown of displaying information 1014a for customer 1013a and information 1014b for customer 1013b.

[0432] Here, the structure shown in FIG22B can detect the standing position, eye height, and gaze direction of customers 1013a and 1013b, and control the position of the display unit 1011 to display information based on this information. Thus, the image can be displayed at the most suitable position in relation to the position of the fish behind the display unit 1011 in relation to the customer's gaze.

[0433] Furthermore, the display unit 1011 preferably functions as a touch panel or a contactless touch panel. Alternatively, the images displayed on the display unit 1011 of the sink can be operated using an application on a smartphone. Additionally, the information displayed on the display unit 1011 can be operated via touch or a smartphone. Furthermore, the display unit 1011 can be used to order, reserve, or order goods from the specialty shops within the facility. Additionally, it can be used to reserve seats at the restaurants within the facility, place orders, order takeout, or order gifts.

[0434] FIG23 shows a structural example of a vehicle equipped with a display unit 1021. The display unit 1021 employs a display device according to an embodiment of the present invention. Note that although FIG23 shows an example of the display unit 1021 mounted on a right-hand drive vehicle, it is not limited thereto and can also be mounted on a left-hand drive vehicle. In this case, the left and right configurations of the structure shown in FIG23 are interchanged.

[0435] Figure 23 shows the instrument panel 1022, steering wheel 1023, windshield 1024, etc., configured in the driver's seat and passenger seat. The instrument panel 1022 is provided with air vents 1026.

[0436] A display unit 1021 is provided on the side of the windshield 1024 facing the driver's seat. The driver can see the scenery outside the window through the display unit 1021 while driving.

[0437] The display unit 1021 can display various information related to driving. For example, it can display map information, navigation information, weather, temperature, air pressure, and images from the vehicle's camera. In addition, when it is an autonomous vehicle, since the driver does not need to drive, it can also display various images unrelated to driving, such as video content.

[0438] Alternatively, multiple cameras 1025 for capturing images of the rear side can be installed on the exterior of the vehicle. Although Figure 23 shows an example of installing a camera 1025 instead of a side mirror, both a side mirror and a camera can also be installed.

[0439] Camera 1025 can be a CCD camera or a CMOS camera, etc. In addition, an infrared camera can also be used in combination with the above-mentioned cameras. Since the output level of the infrared camera increases with the temperature of the subject, it can detect or extract living organisms such as humans or animals.

[0440] The image captured by the camera 1025 can be output to the display unit 1021. The display unit 1021 is mainly used to assist driving. By using the camera 1025 to capture a wide-angle image of the rear side and displaying the image on the display unit 1021, the driver can see blind spots and prevent accidents from occurring.

[0441] Furthermore, the display unit 1021 preferably has an authentication method. For example, by having the driver touch the display unit 1021, the vehicle can perform biometric authentication such as fingerprint authentication or palm print authentication. The vehicle can have the following functions: when the driver is authenticated by biometric authentication, the environment is adjusted to the driver's preferred environment. For example, it is preferable to adjust one or more of the following after authentication: seat position adjustment, steering wheel position adjustment, camera 1025 orientation adjustment, brightness setting, air conditioning setting, wiper speed (frequency) setting, audio volume setting, and audio playlist reading. Note that the steering wheel 1023 may also have an authentication method instead of the display unit 1021.

[0442] In addition, when the driver is authenticated by biometrics, the car can be made drivable, such as with the engine running, so the key is no longer needed, which is better.

[0443] At least a portion of this embodiment may be implemented in combination with other embodiments described in this specification. [Simplified Explanation of the Diagram]

[0024] Figures 1A and 1B are diagrams showing examples of the structure of a display device. Figures 2A to 2F are diagrams showing examples of the structure of a display device. Figures 3A to 3F are diagrams showing examples of the structure of a display device. Figures 4A and 4B are diagrams showing examples of the structure of a display device. Figures 5A to 5D are diagrams showing examples of the structure of a display device. Figures 6A to 6F are diagrams showing examples of the structure of a display device. Figures 7A to 7E are diagrams showing examples of the structure of a display device. Figures 8A to 8F are diagrams showing examples of the structure of a display device. Figures 9A to 9F are diagrams showing examples of the structure of a display device. Figures 10A to 10F are diagrams showing examples of the structure of a display device. Figures 11A1, 11A2, 11B1, and 11B2 are diagrams illustrating structural examples of a display device. Figures 12A1, 12A2, 12B1, and 12B2 are diagrams illustrating structural examples of a display device. Figures 13A and 13B are diagrams illustrating structural examples of a display device. Figures 14A to 14D are diagrams illustrating structural examples of a display device. Figures 15A to 15D are diagrams illustrating structural examples of a display device. Figures 16A and 16B are diagrams illustrating structural examples of a display device. Figures 17A and 17B are diagrams illustrating structural examples of a display device. Figure 18 is a diagram illustrating a structural example of a display device. Figure 19A is a cross-sectional view illustrating an example of a display device. Figure 19B is a cross-sectional view illustrating an example of a transistor. Figures 20A to 20F are diagrams illustrating structural examples of light-emitting devices. Figures 21A to 21D are diagrams illustrating an example of a pixel in a display device. Figures 21E and 21F are diagrams illustrating an example of a circuit for a pixel in a display device. Figures 22A and 22B are diagrams illustrating application examples of a display device. Figure 23 is a diagram illustrating an application example of a display device.

Claims

1. A display device, comprising: Includes the first region of the first light-emitting element; The second region includes the second light-emitting element; The third region through which external light passes; An insulating layer is continuously disposed in the first region, the second region, and the third region. The first light-emitting element includes a first pixel electrode, a first organic layer, and a common electrode. The second light-emitting element includes a second pixel electrode, a second organic layer, and the common electrode. The first pixel electrode and the second pixel electrode are disposed side by side. The first organic layer is disposed on the first pixel electrode. The second organic layer is disposed on the second pixel electrode. When viewed in cross-section, the angle formed by the bottom surface and the side surface of the first organic layer and the angle formed by the bottom surface and the side surface of the second organic layer are both between 60 degrees and 120 degrees. The insulating layer includes a portion overlapping the first organic layer with the common electrode, a portion overlapping the second organic layer with the common electrode, and a portion located in the third region. Furthermore, the insulating layer is transparent.

2. The display device of claim 1, wherein the first organic layer and the second organic layer comprise compounds with different luminescent properties.

3. The display device of claim 1, wherein the first organic layer and the second organic layer contain compounds with the same luminescent properties, and a color layer or color conversion layer is disposed at a position overlapping the first light-emitting element.

4. The display device of any one of claims 1 to 3, wherein the common electrode is light-transmitting, and the common electrode includes a portion located in the third region.

5. The display device of any one of claims 1 to 3, wherein the common electrode is transparent and reflective, and the common electrode has an opening that overlaps with the third region.

6. The display device according to any one of claims 1 to 5 further includes a second insulating layer covering the end of the first pixel electrode and the end of the second pixel electrode, wherein the second insulating layer has a portion overlapping the third region.

7. The display device according to any one of claims 1 to 5 further includes a second insulating layer covering the end of the first pixel electrode and the end of the second pixel electrode, wherein the second insulating layer has an opening in the portion overlapping the third region.

8. The display device of any one of claims 1 to 7 further includes a third insulating layer, wherein the third insulating layer comprises an organic resin, the third insulating layer includes a first portion located between the first light-emitting element and the second light-emitting element, the first organic layer and the second organic layer sandwiching the first portion of the third insulating layer opposite each other, and the third insulating layer has a second portion overlapping the third region.

9. The display device of any one of claims 1 to 7 further includes a third insulating layer, wherein the third insulating layer comprises an organic resin, the third insulating layer includes a first portion located between the first light-emitting element and the second light-emitting element, the first organic layer and the second organic layer sandwiching the first portion of the third insulating layer are opposed to each other, and the third insulating layer has an opening in the portion overlapping the third region.

10. The display device of claim 8 or 9 further includes a fourth insulating layer, wherein the fourth insulating layer comprises an inorganic insulating film, the fourth insulating layer includes a third portion located between the first light-emitting element and the second light-emitting element, the fourth insulating layer is disposed along the side and bottom surfaces of the third insulating layer, and the side surfaces of the first organic layer and the second organic layer respectively contact the fourth insulating layer.

11. The display device of claim 10, wherein the side surface of the first pixel electrode and the side surface of the second pixel electrode are respectively in contact with the fourth insulating layer.

12. The display device of any one of claims 8 to 11, wherein the first portion of the third insulating layer includes a portion with a convex top surface.

13. The display device of any one of claims 8 to 11, wherein the first portion of the third insulating layer includes a portion with a concave top surface.

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