Display device and method for manufacturing display device

Abstract

One embodiment of the present invention provides a display device with a camera function. A display device or camera device with a high aperture ratio is provided. The display device includes a first light-emitting element and a light-receiving element. The first light-emitting element includes a first pixel electrode, a first organic layer, and a common electrode. The light-receiving element includes a second pixel electrode, a second organic layer, and a common electrode. The first organic layer includes a first light-emitting layer, and the second organic layer includes a photoelectric conversion layer. A first layer and a second layer are included in the region between the first light-emitting element and the light-receiving element. The first layer overlaps with the second organic layer and the second pixel electrode and contains the same material as the first organic layer. The second layer overlaps with the first organic layer and the first pixel electrode and contains the same material as the second organic layer. In the region between the first light-emitting element and the light-receiving element, the ends of the first organic layers are opposite each other, and the ends of the second organic layers are opposite each other.

Description

[Technical Field]

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

[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, methods for driving these devices, and methods for manufacturing these devices. A semiconductor device refers to any device capable of operating using the characteristics of a semiconductor. [Previous Technology]

[0003] In recent years, display devices have been required to be high-definition in order to display high-resolution images. In information terminal devices such as smartphones, tablets, and laptop PCs (personal computers), display devices are required to be low-power in addition to high definition. Furthermore, in addition to the function of displaying images, display devices are required to have various functions, such as touch panel functions and fingerprint scanning functions for personal identification.

[0004] As a display device, for example, a light-emitting device including a light-emitting element has been developed. Light-emitting elements (also referred to as "EL elements") that utilize the electroluminescence (EL) phenomenon have the characteristics of being easy to achieve in thin and lightweight form; being able to respond to input signals at high speed; and being able to be driven by a DC constant voltage power supply, etc., and have been applied to display devices. For example, Patent Document 1 discloses a flexible light-emitting device using an organic EL element.

[0005] [Patent Document 1] Japanese Patent Application Publication No. 2014-197522 [Summary of the Invention]

[0006] One objective of one embodiment of the present invention is to provide a display device with a camera function. Another objective of one embodiment of the present invention is to provide a camera device or display device including a high-resolution display section. Furthermore, one objective of one embodiment of the present invention is to provide a display device or camera device with a high aperture ratio. Another objective of one embodiment of the present invention is to provide a camera device or display device capable of performing high-sensitivity imaging. Another objective of one embodiment of the present invention is to provide a display device capable of acquiring biometric information such as fingerprints. Furthermore, one objective of one embodiment of the present invention is to provide a display device used as a touch panel.

[0007] One objective of one embodiment of the present invention is to provide a display device, camera device, or electronic device with high reliability. Another objective of one embodiment of the present invention is to provide a display device, camera device, or electronic device with a novel structure. Yet another objective of one embodiment of the present invention is to improve 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, which includes a first light-emitting element and a light-receiving element. A first pixel electrode, a first organic layer, and a common electrode are sequentially stacked in the first light-emitting element. A second pixel electrode, a second organic layer, and a common electrode are sequentially stacked in the light-receiving element. The first organic layer includes a first light-emitting layer. The second organic layer includes a photoelectric conversion layer. A first layer and a second layer are included in the region between the first light-emitting element and the light-receiving element. The first layer overlaps with the second organic layer and contains the same material as the first organic layer. The second layer overlaps with the first organic layer and contains the same material as the second organic layer. In the region between the first light-emitting element and the light-receiving element, the ends of the first organic layer are opposite to the ends of the first layer. In the region between the first light-emitting element and the light-receiving element, the ends of the second organic layer are opposite to the ends of the second layer. The first layer has a portion overlapping with the second pixel and the second organic layer. The second layer has a portion overlapping with the first pixel electrode and the first organic layer.

[0010] Furthermore, in the above-described display device, a second light-emitting element is preferably included. A third pixel electrode, a third organic layer, and a common electrode are sequentially stacked in the second light-emitting element. The third organic layer includes the second light-emitting layer. Additionally, a third layer and a fourth layer are included in the region between the second light-emitting element and the first light-emitting element. The third layer preferably overlaps with the third organic layer and contains the same material as the first organic layer. The fourth layer preferably overlaps with the first organic layer and contains the same material as the third organic layer. Furthermore, in the region between the second light-emitting element and the first light-emitting element, the end of the first organic layer preferably faces the end of the third layer. Moreover, in the region between the second light-emitting element and the first light-emitting element, the end of the third organic layer preferably faces the end of the fourth layer. Additionally, the third layer preferably has a portion that overlaps with the third pixel electrode and the third organic layer. Furthermore, the fourth layer preferably has a portion that overlaps with the first pixel electrode and the first organic layer.

[0011] Furthermore, in any of the above-described display devices, it is preferable that a connection portion is provided between the first light-emitting element and the light-receiving element. This connection portion has an electrode made of the same material as the first pixel electrode. In this case, it is preferable that the first layer is disposed separately from the electrode and the second layer is disposed separately from the electrode. Furthermore, it is preferable that the electrode and a common electrode are electrically connected.

[0012] Furthermore, in any of the above-described display devices, a resin layer is preferably included. The resin layer is located in the region between the first light-emitting element and the light-receiving element. Additionally, the ends of the first organic layer and the ends of the first layer are preferably positioned opposite each other, sandwiching the resin layer. Furthermore, the ends of the second organic layer and the ends of the second layer are preferably positioned opposite each other, sandwiching the resin layer.

[0013] Furthermore, in any of the above-described display devices, a first insulating layer is preferably included. The first insulating layer is located between the first light-emitting element and the light-receiving element. Additionally, the first insulating layer is preferably in contact with the ends of the first organic layer, the ends of the second organic layer, the ends of the first layer, and the ends of the second layer.

[0014] Another embodiment of the present invention is a method for manufacturing a display device, comprising: a first process for forming a first pixel electrode and a second pixel electrode in parallel; a second process for forming an island-shaped first organic layer on the first pixel electrode using a first metal mask; a third process for forming an island-shaped second organic layer on the second pixel electrode and the first organic layer using a second metal mask; a fourth process for etching the first organic layer and the second organic layer in a region between the first pixel electrode and the second pixel electrode; and a fifth process for forming a common electrode covering the first organic layer and the second organic layer. The first organic layer comprises a luminescent organic compound, and the second organic layer comprises a photoelectric conversion material. Furthermore, in the second process, the first organic layer is formed such that a portion of the first organic layer overlaps with the second pixel electrode. Moreover, in the third process, the second organic layer is formed such that a portion of the second organic layer overlaps with the first pixel electrode.

[0015] In addition, in the above method, it is preferable to include a sixth process, which forms a resin layer in the slit formed by etching, after the fourth process and before the fifth process.

[0016] In addition, in the above method, it is preferable to use a photosensitive organic resin as the resin layer.

[0017] In addition, in any of the above methods, it is preferable to include a seventh process after the fourth process and before the sixth process, in which the first insulating layer is formed by contacting the side surfaces of the first organic layer and the second organic layer exposed by etching.

[0018] Furthermore, in the above method, the first insulating layer is preferably an oxide metal film formed by atomic layer deposition.

[0019] According to one embodiment of the present invention, a display device with a camera function can be provided. Additionally, according to one embodiment of the present invention, a camera device or display device including a high-resolution display section can be provided. Furthermore, according to one embodiment of the present invention, a display device or camera device with a high aperture ratio can be provided. Furthermore, according to one embodiment of the present invention, a camera device or display device capable of performing high-sensitivity imaging can be provided. Furthermore, according to one embodiment of the present invention, a display device capable of acquiring biometric information such as fingerprints can be provided. Moreover, according to one embodiment of the present invention, a display device used as a touch panel can be provided.

[0020] Furthermore, according to one embodiment of the present invention, a display device, camera device, or electronic device with high reliability can be provided. Additionally, according to one embodiment of the present invention, a display device, camera device, or electronic device with a novel structure can be provided. Moreover, according to one embodiment of the present invention, at least one of the problems of the prior art can be solved.

[0021] Note that the description of these effects does not preclude the existence of other effects. Furthermore, one embodiment of the present invention does not necessarily require all of the above-described effects. Additionally, effects other than those described above can be derived from the description in the specification, drawings, claims, etc.

Implementation Method

[0023] 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.

[0024] 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.

[0025] 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.

[0026] 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.

[0027] Note that, in the following, the directions such as "up" and "down" are used basically in accordance with the directions in the drawings. However, for the sake of simplicity, the directions indicated by "up" or "down" in the specification are sometimes inconsistent with those in the drawings. For example, when describing the stacking sequence (or formation sequence) of laminates, etc., even if the surface on the side where the laminate is set (the formed surface, support surface, mating surface, flat surface, etc.) is located on the upper side of the laminate in the drawing, this direction is sometimes written as "down", or the opposite direction is written as "up", etc.

[0028] In this specification and the like, the terms "film" and "layer" may be interchanged. For example, sometimes "conductive layer" may be changed to "conductive film". In addition, for example, sometimes "insulating layer" may be changed to "insulating film".

[0029] Note that in this specification, the EL layer refers to a layer disposed between a pair of electrodes of the 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.

[0030] 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.

[0031] 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.

[0032] Embodiment 1 In this embodiment, an example of the structure of a display device according to an embodiment of the present invention and an example of a method for manufacturing the display device will be described.

[0033] One embodiment of the present invention is a display device comprising a light-emitting element (also referred to as a light-emitting device) and a light-receiving element (also referred to as a light-receiving device). The light-emitting element comprises a pair of electrodes and an EL layer between the pair of electrodes. The light-receiving element comprises a pair of electrodes and an active layer between the pair of electrodes. The light-emitting element is preferably an organic EL element (organic electric field light-emitting element). The light-receiving element is preferably an organic photodiode (organic photoelectric conversion element).

[0034] Furthermore, the display device preferably includes two or more light-emitting elements with different emitting colors. Each light-emitting element with different emitting colors includes 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.

[0035] Since imaging can be performed using multiple light-receiving elements, one embodiment of the present invention is used as an imaging device. In this case, the light-emitting element can be used as a light source for imaging. Furthermore, since images can be displayed using multiple light-emitting elements, one embodiment of the present invention is used as a display device. Therefore, it can be said that one embodiment of the present invention is a display device with imaging function or an imaging device with display function.

[0036] For example, in the display section of a display device according to one embodiment of the present invention, the light-emitting elements are arranged in a matrix, and the light-receiving elements are arranged in a matrix. Therefore, the display section has the function of displaying images and is used as a light-receiving section. Since images can be captured by multiple light-receiving elements provided in the display section, the display device can be used as an image sensor or a touch panel, etc. That is, images can be captured or the proximity or contact of an object can be detected by the display section. Furthermore, the light-emitting elements provided in the display section can be used as a light source when receiving light, so it is not necessary to provide a light source separately from the display device, and a highly functional display device can be realized without increasing the number of electronic components.

[0037] In one embodiment of the present invention, when the light-emitting element in the object reflection display section emits light, the light-receiving element can detect the reflected light, so that even in a dark environment, it is possible to perform photography, touch (including non-contact) detection, etc.

[0038] Furthermore, in a display device according to one embodiment of the present invention, fingerprints or palm prints can be captured when a finger, palm, or the like touches the display unit. Therefore, an electronic device including a display device according to one embodiment of the present invention can perform personal identification using images of captured fingerprints or palm prints. This eliminates the need for a separate camera device for fingerprint or palm print recognition and reduces the number of components in the electronic device. Moreover, since the display unit has light-receiving elements arranged in a matrix, fingerprints or palm prints can be captured from any part of the display unit, thus enabling a convenient electronic device.

[0039] 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.

[0040] In the manufacturing method using FMM, in order to achieve high resolution and high aperture ratio, two adjacent island-shaped organic films can be formed by overlapping portions of each other. This significantly reduces the distance between the light-emitting areas compared to the case where the two island-shaped organic films do not overlap. However, when two adjacent island-shaped organic films are formed in an overlapping manner, current leakage sometimes occurs between the two adjacent light-emitting elements through the overlapping organic films, resulting in unintended light emission. This leads to a decrease in brightness, a decrease in contrast, and a deterioration in display quality. Furthermore, power efficiency and power consumption decrease due to leakage current.

[0041] In addition, when leakage current is generated between the light-emitting element and the light-receiving element, since the leakage current becomes the main cause of noise when using the light-receiving element for imaging, the sensitivity (S / N ratio) of the imaging may decrease.

[0042] Therefore, in one embodiment of the present invention, organic films are formed separately using an open-film mirror (FMM) in such a way that portions of the organic films between adjacent light-emitting elements and light-receiving elements, or between two adjacent light-emitting elements, overlap each other. Specifically, an FMM is used to form a layer containing a luminescent compound (also called a light-emitting layer) in the light-emitting element and a layer containing a photoelectric conversion material (also called an active layer or photoelectric conversion layer) in the light-receiving element. At this time, a common film can be used between the light-emitting elements and between the light-emitting elements and the light-receiving elements instead of forming separate organic films. An organic laminate film, in which the light-emitting layer, the active layer, and other organic films are stacked, is located between adjacent light-emitting elements and light-receiving elements. Then, a portion of the organic laminate film is etched using photolithography to divide the organic laminate film. This divides the leakage path (leakage channel) of the current between the light-emitting element and the light-receiving element. Therefore, noise during imaging using the light-receiving element can be reduced, enabling high-precision imaging.

[0043] In this way, the leakage current (also known as side leakage or side leakage current) between the light-emitting element and the light-receiving element is suppressed, thereby enabling high-precision imaging with a high signal-to-noise ratio (S / N ratio). Therefore, clear imaging can be performed even in low-light environments. Thus, the brightness of the light-emitting element used as a light source during imaging can be reduced, thereby reducing power consumption.

[0044] Furthermore, the leakage path (leakage channel) of the current can be divided between two adjacent light-emitting elements. As a result, it is possible to improve brightness, contrast, power efficiency, or power consumption.

[0045] Furthermore, in order to protect the sides of the organic laminate film exposed by etching, it is preferable to form an insulating layer. This can improve the reliability of the display device.

[0046] The organic film formed using FMM can be arranged in a manner that overlaps not only with the pixel electrode of the target element but also with the pixel electrodes of adjacent elements. This allows for a higher density of pixel electrodes. In this case, a portion of the organic film of an adjacent element is overlapped on the pixel electrode of one element.

[0047] Furthermore, it is preferable to provide an electrode electrically connected to the common electrode between two adjacent light-emitting elements or between a light-emitting element and a light-receiving element. This electrode can be used as an auxiliary electrode or auxiliary wiring to enhance the conductivity of the common electrode. Alternatively, it can be used as an electrode to connect the common electrode and the auxiliary wiring. Thus, even in large display devices, the effect of voltage drop caused by the resistance of the common electrode can be suppressed.

[0048] The following describes an example of the structure and manufacturing method of a display device according to an embodiment of the present invention with reference to the drawings.

[0049] [Structural Example 1] FIG1A shows a top view of the display device 100. The display device 100 includes a plurality of light-emitting elements 110R that emit red light, a plurality of light-emitting elements 110G that emit green light, a plurality of light-emitting elements 110B that emit blue light, and a plurality of light-receiving elements 110S. In FIG1A, in order to simply distinguish each light-emitting element, the symbols R, G, B, and S are attached to the light-emitting area of ​​each light-emitting element or light-receiving element.

[0050] The light-emitting elements 110R, 110G, 110B, and 110S are all arranged in a matrix. Figure 1A shows a structure in which two elements are arranged alternately in one direction. Note that the arrangement of the light-emitting elements is not limited to this; stripe arrangement, S-stripe arrangement, Delta arrangement, Bayer arrangement, or zigzag arrangement can be used, as well as Pentile arrangement or Diamond arrangement.

[0051] As light-emitting elements 110R, 110G, and 110B, 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.

[0052] As the light-receiving element 110S, a pn-type or pin-type photodiode can be used, for example. The light-receiving element 110S is used as a photoelectric conversion element that detects light incident on the light-receiving element 110S and generates a charge. In the photoelectric conversion element, the amount of charge generated is determined according to the amount of incident light. In particular, as the light-receiving element 110S, an organic photodiode comprising a layer containing an organic compound is preferred. Organic photodiodes are easy to make thin, lightweight, and large-area, and their shape and design are highly flexible, so they can be applied to a wide variety of devices.

[0053] Additionally, FIG1A shows a connecting electrode 111C electrically connected to the common electrode 113. The connecting electrode 111C is supplied with a potential (e.g., anode potential or cathode potential) for supplying to the common electrode 113. The connecting electrode 111C is disposed outside the display area where the light-emitting elements 110R, etc., are arranged. In FIG1A, the common electrode 113 is indicated by a dashed line.

[0054] The connection electrode 111C can be provided along the outer periphery of the display area. For example, it can be provided along one side of the outer periphery of the display area, or it can 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 can be strip-shaped, L-shaped, "冂"-shaped (square bracket-shaped), or quadrangular, etc.

[0055] In addition, the connection part 140 is shown in Fig. 1A. The connection part 140 is the connection part between the common electrode 113 and the electrode 111A. The electrode 111A itself can be used as an auxiliary wiring, and the electrode 111A can also be used as an electrode or wiring for connecting the auxiliary wiring and the common electrode 113. The arrangement method of the connection part 140 is not limited, and it can be arranged periodically or non-periodically (randomly).

[0056] Figs. 1B, 1C, and 1D are respectively cross-sectional schematic views corresponding to the dotted line A1-A2, the dotted line B1-B2, and the dotted line C1-C2 in Fig. 1A. Fig. 1B shows a cross-sectional schematic view of the light-emitting element 110G, the light-emitting element 110R, and the light-receiving element 110S, Fig. 1C shows a cross-sectional schematic view of the connection part 140, and Fig. 1D shows a cross-sectional schematic view of the connection electrode 111C.

[0057] Fig. 1B shows the cross-sections of the light-emitting element 110R, the light-emitting element 110G, and the light-receiving element 110S. The light-emitting element 110R includes a pixel electrode 111R, an organic layer 115, an organic layer 112R, an organic layer 116, an organic layer 114, and a common electrode 113. The light-emitting element 110G includes a pixel electrode 111G, an organic layer 115, an organic layer 112G, an organic layer 116, an organic layer 114, and a common electrode 113. The light-receiving element 110S includes a pixel electrode 111S, an organic layer 115, an organic layer 155, an organic layer 116, an organic layer 114, and a common electrode 113. The light-emitting element 110R, the light-emitting element 110G, the light-receiving element 110S, and the light-emitting element 110B (not shown) commonly use the organic layer 114 and the common electrode 113. The organic layer 114 can also be said to be a common layer.

[0058] The organic layer 112R included in the light-emitting element 110R contains at least a light-emitting organic compound that emits red light. The organic layer 112G included in the light-emitting element 110G contains at least a light-emitting organic compound that emits green light. The organic layer 112B (not shown), which is included in the light-emitting element 110B, contains at least a light-emitting organic compound that emits blue light. Each of the organic layer 112R, the organic layer 112G, and the organic layer 112B can also be referred to as a light-emitting layer.

[0059] The organic layer 155 in the light-receiving element 110S contains a photoelectric conversion material sensitive to wavelength regions of visible or infrared light. Preferably, the wavelength regions of sensitivity of the photoelectric conversion material in the organic layer 155 include one or more of the wavelength regions of light emitted by the light-emitting element 110R, the light emitted by the light-emitting element 110G, and the light emitted by the light-emitting element 110B. Alternatively, a photoelectric conversion material sensitive to infrared light with wavelengths longer than those emitted by the light-emitting element 110R may also be used. The organic layer 155 may also be referred to as an active layer or a photoelectric conversion layer.

[0060] Hereinafter, when describing the common features among light-emitting elements 110R, 110G, and 110B, they will sometimes be referred to as light-emitting element 110. Similarly, when describing the common features among components such as organic layers 112R, 112G, and 112B, which are distinguished by letters, symbols with omitted letters will sometimes be used.

[0061] In each light-emitting element, the stacked film located between the pixel electrode and the common electrode 113 can be referred to as the EL layer. In addition, in the light-receiving element 110S, the stacked film located between the pixel electrode 111S and the common electrode 113 can be referred to as the PD layer.

[0062] In each light-emitting element or light-receiving element 110S, the organic layer 115 is a layer located between the organic layer 112 or the organic layer 155 and the pixel electrode 111. Additionally, the organic layer 116 is a layer located between the organic layer 112 or the organic layer 155 and the organic layer 114. The organic layer 114 is a layer located between the organic layer 116 and the common electrode 113.

[0063] Organic layers 115, 116, and 114 may each independently include one or more of an electron injection layer, an electron transport layer, a hole injection layer, and a hole transport layer. For example, the following structure may be adopted: organic layer 115 has a stacked structure including a hole injection layer and a hole transport layer from the pixel electrode 111 side, organic layer 116 includes an electron transport layer, and organic layer 114 includes an electron injection layer. Alternatively, the following structure may be adopted: organic layer 115 has a stacked structure including an electron injection layer and an electron transport layer from the pixel electrode 111 side, organic layer 116 includes a hole transport layer, and organic layer 114 includes a hole injection layer.

[0064] Note that regarding organic layers 112, 114, 115, 116, and 155, which are located between a pair of electrodes of the light-emitting element or light-receiving element 110S, "organic layer" means the layer that constitutes the organic EL element or organic photoelectric conversion element, and does not need to contain organic compounds. For example, organic layers 112, 114, 115, and 116 may not contain organic compounds, and films containing only inorganic compounds or inorganic materials may be used.

[0065] Pixel electrodes 111R, 111G, and 111B (not shown) are provided for each light-emitting element. Additionally, the common electrode 113 and organic layer 114 are provided as a single layer shared by all light-emitting elements and light-receiving elements 110S. 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.

[0066] A protective layer 121 is provided on the common electrode 113 to cover the light-emitting elements 110R, 110G, 110S, and 110B (not shown). The protective layer 121 has the function of preventing water and other impurities from diffusing from above to each light-emitting element.

[0067] A slit 120 is provided between adjacent light-emitting elements and light-receiving elements 110S and between two adjacent light-emitting elements. The slit 120 corresponds to the portion of the organic layer 112 or organic layer 155, organic layer 115 and organic layer 116 located between adjacent light-emitting elements and light-receiving elements 110S or between two adjacent light-emitting elements.

[0068] An insulating layer 125 and a resin layer 126 are provided in the slit 120. The insulating layer 125 is provided along the sidewall and bottom surface of the slit 120. The resin layer 126 is provided on the insulating layer 125 and has the function of filling the recess of the slit 120 to flatten the top surface of the slit. By flattening the recess of the slit 120 by the resin layer 126, the coverage of the organic layer 114, the common electrode 113, and the protective layer 121 can be improved.

[0069] Furthermore, the slits 120 can be formed simultaneously with the openings of external connection terminals such as the connecting electrode 111C, allowing them to be formed without increasing the processing steps. Additionally, since the slits 120 include an insulating layer 125 and a resin layer 126, they prevent short circuits between the pixel electrode 111 and the common electrode 113. Furthermore, the resin layer 126 improves the adhesion of the organic layer 114. That is, by providing the resin layer 126 to improve the adhesion of the organic layer 114, film peeling of the organic layer 114 can be suppressed.

[0070] The insulating layer 125 is provided in contact with the side of the organic layer (e.g., organic layer 115, etc.), so the organic layer may not be in contact with the resin layer 126. When the organic layer is in contact with the resin layer 126, the organic layer may sometimes dissolve due to organic solvents or the like contained in the resin layer 126. Therefore, as shown in this embodiment, by providing the insulating layer 125 between the organic layer and the resin layer 126, the side of the organic layer can be protected. In addition, the slit 120 may have at least one or more of the following structures: a hole injection layer, a hole transport layer, an electron suppression layer, a light-emitting layer, an active layer, a hole suppression layer, an electron transport layer, and an electron injection layer.

[0071] 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 films, hafnium oxide films, and silicon oxide films formed by the ALD method for insulating layer 125, an insulating layer 125 with fewer pinholes and excellent protection of the EL layer can be formed.

[0072] 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, while "silicon oxynitride" refers to a material in which the nitrogen content is greater than the oxygen content in its composition.

[0073] 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.

[0074] 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. In addition, 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.

[0075] In addition, a photosensitive resin can be used as the resin layer 126. A photoresist can also be used as the photosensitive resin. A positive or negative material can also be used as the photosensitive resin.

[0076] 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.

[0077] 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.

[0078] The top surface of the resin layer 126 should be as flat as possible, but sometimes it is a gently curved shape. Figure 1B shows an example of a wavy shape with concave and convex portions on the top surface of the resin layer 126, but it is not limited to this. For example, the top surface of the resin layer 126 can be a convex surface, a concave surface, or a plane.

[0079] A laminated film of inorganic and organic insulating films can also 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. In addition, the organic insulating film is preferably used as a planarization film. Therefore, the top surface of the organic insulating film can be flattened, so the coverage of the inorganic insulating film thereon is improved, thereby improving the barrier properties. In addition, 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, the electrode of a touch sensor, or a lens array, etc.) is provided above the protective layer 121, which is preferable.

[0080] 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.

[0081] FIG1C shows a connection portion 140 for electrically connecting electrode 111A and common electrode 113. In the connection portion 140, an opening is provided in the insulating layer 125 and the resin layer 126 on electrode 111A. In this opening, electrode 111A and common electrode 113 are electrically connected by organic layer 114.

[0082] FIG1D shows a connection portion 130 where the connecting electrode 111C and the common electrode 113 are electrically connected. In the connection portion 130, the common electrode 113 is disposed on the connecting electrode 111C with an organic layer 114 in between. In addition, an insulating layer 125 is disposed in contact with the side of the connecting electrode 111C, and a resin layer 126 is disposed on the insulating layer 125.

[0083] Note that the organic layer 114 may not be provided in the connecting portion 130. In this case, a common electrode 113 is provided on the connecting electrode 111C in a manner that contacts the connecting electrode 111C, and a protective layer 121 is provided to cover the common electrode 113.

[0084] The connecting portion 130 and the connecting portion 140 can be formed in the same way and have the same structure, but sometimes the resin layer 126 in the connecting portion 140 is thicker than that in the connecting portion 130. This is because the connecting portion 140 is surrounded by light-emitting elements or light-receiving elements, while the connecting portion 130 is relatively flat.

[0085] Next, the suitable structure of the slit 120 and its vicinity will be described in detail. FIG2A is a schematic cross-sectional view including a portion of the light-emitting element 110R in FIG1B, a portion of the light-emitting element 110G, and the region therebetween.

[0086] As shown in FIG. 2A, the end of the pixel electrode 111 preferably has a tapered shape. This improves the step coverage of the organic layer 115, etc. Note that in this specification, "the end of the object has a tapered shape" means having a cross-sectional shape such that the angle formed between the surface and the surface to be formed in the region of its end is greater than 0° and less than 90°; and its thickness gradually increases from the end. Although a single-layer structure is shown here for the pixel electrode 111R, etc., multiple layers can also be stacked.

[0087] An organic layer 115 is provided on the pixel electrode 111R. Additionally, an organic layer 115 is provided on the pixel electrode 111G. The aforementioned organic layer 115 is formed by dividing a continuous film by a slit 120.

[0088] On the side where the light-emitting element 110R is disposed with reference to slit 120, an organic layer 112R is disposed on top of the organic layer 115. Additionally, on the side where the light-emitting element 110G is disposed with reference to slit 120, a layer 135R is disposed on the organic layer 115. Layer 135R can also be described as a fragment that becomes part of the film of organic layer 112R, separated by slit 120 and remaining on the side of the light-emitting element 110G. Layer 135R and organic layer 112R are disposed separately across slit 120.

[0089] Furthermore, on the side where the light-emitting element 110G is disposed with reference to slit 120, an organic layer 112G is disposed on top of the organic layer 115. Additionally, on the side where the light-emitting element 110R is disposed with reference to slit 120, a layer 135G is disposed on the organic layer 112R. Layer 135G can also be described as a fragment that becomes part of the film of the organic layer 112G, separated by slit 120 and remaining on the side of the light-emitting element 110R. Layer 135G and the organic layer 112G are disposed separately across slit 120.

[0090] The ends (sides) of organic layer 112R and the ends of layer 135R are opposite each other across a slit 120. The ends of organic layer 112G and the ends of layer 135G are also opposite each other across a slit 120.

[0091] Note that, depending on the position and width of the slit 120, the position where the organic layer 112R is formed, the position where the organic layer 112G is formed, etc., sometimes one or both of layers 135R and 135G are not formed. Specifically, if the end of the organic layer 112R before the formation of the slit 120 overlaps with the position where the slit 120 is formed, sometimes layer 135R is not formed.

[0092] An organic layer 116 is provided covering the organic layer 112R and the layer 135G. Similarly, an organic layer 116 is provided covering the organic layer 112G and the layer 135R. Like the organic layer 115, the organic layer 116 is formed by dividing a continuous film by a slit 120.

[0093] An insulating layer 125 is disposed inside the slit 120 and is disposed in such a manner that it contacts the side surfaces of a pair of organic layers 115, the side surfaces of organic layers 112R, the side surfaces of organic layers 112G, the side surfaces of layer 135R, the side surfaces of layer 135G, and the side surfaces of a pair of organic layers 116. In addition, the insulating layer 125 is disposed in such a manner that it covers the top surface of the substrate 101.

[0094] The resin layer 126 is provided in contact with the top surface and side surface of the insulating layer 125. The resin layer 126 has the function of planarizing the recesses of the formed surface of the organic layer 114.

[0095] An organic layer 114, a common electrode 113, and a protective layer 121 are sequentially formed on the top surface covering the organic layer 116, the insulating layer 125, and the resin layer 126. Note that the organic layer 114 can be omitted if it is not needed.

[0096] Here, layers 135R and 135G are portions located at the ends of the film that will become organic layer 112R or organic layer 112G. In the deposition method using FMM, the thickness of the organic film tends to become thinner closer to the end, so layers 135R and 135G have portions that are thinner than organic layer 112R or organic layer 112G. Sometimes layers 135R and 135G are so thin that they cannot be detected in cross-sectional observation. In addition, even if layers 135R or 135G are present, it is sometimes difficult to confirm the boundary between layer 135R and organic layer 112G or the boundary between layer 135G and organic layer 112R in cross-sectional observation.

[0097] On the other hand, layers 135R and 135G contain luminescent compounds (e.g., fluorescent materials, phosphorescent materials, or quantum dots), so by irradiating the plane with ultraviolet or visible light, photoluminescence can be obtained. By observing this luminescence using an optical microscope or the like, the presence of layers 135R and 135G can be confirmed. Specifically, because layer 135R overlaps with organic layer 112G in the portion where layer 135R is disposed, both light from layer 135R and light from organic layer 112G are confirmed when ultraviolet light or the like is irradiated onto that portion. Furthermore, based on the emission spectrum, wavelength, emission color, etc., it can be confirmed that layer 135R or layer 135G contains the same material as organic layer 112R or organic layer 112G. In addition, the compounds contained in layers 135R and 135G can sometimes be inferred.

[0098] The end of layer 135R opposite to the slit 120 extends to a region overlapping with pixel electrode 111G. That is, layer 135R has a portion that overlaps with both pixel electrode 111G and organic layer 112G. Similarly, layer 135G has a portion that overlaps with both pixel electrode 111R and organic layer 112R.

[0099] Note that this example shows the use of an FMM to form organic layers 112R and 112G separately and other organic layers (organic layers 115 and 116) into a continuous film, but it is not limited to this. For example, one or both of organic layers 115 and 116 can also be formed separately using an FMM. In this case, fragments of organic layer 115 or organic layer 116 may sometimes remain near the slit 120, similar to those of layer 135R, etc.

[0100] Figure 2B shows a cross-sectional schematic diagram of a portion of the light-emitting element 110G, a portion of the light-receiving element 110S, and the slit 120 located between them.

[0101] A layer 135S is disposed on the side of the light-emitting element 110G and on the organic layer 112G of the slit 120. The layer 135S can also be described as a fragment that is separated by the slit 120 and remains on the side of the light-emitting element 110G, which will become part of the film of the organic layer 155. The end of the layer 135S on the slit 120 side is sandwiched between the end of the organic layer 155 on the slit 120 side and faces each other.

[0102] In addition, a layer 135G is provided on the light-receiving element 110S side of the slit 120 and between the organic layer 115 and the organic layer 155. The end of the slit 120 side of the layer 135G and the end of the slit 120 side of the organic layer 112G are sandwiched and opposite to each other.

[0103] The end of layer 135S opposite to the slit 120 extends to a region overlapping with pixel electrode 111G. That is, layer 135S has a portion that overlaps with both pixel electrode 111G and organic layer 112G. Similarly, layer 135G has a portion that overlaps with both pixel electrode 111S and organic layer 155.

[0104] The enlarged views shown in Figures 2A and 2B illustrate the regions between light-emitting elements 110R and 110G, and between light-emitting elements 110G and light-receiving elements 110S. The same structure also exists between light-emitting elements 110R and 110B, between light-emitting elements 110G and 110B, between light-emitting elements 110R and 110S, and between light-emitting elements 110B and 110S.

[0105] Figures 3A and 3B are cross-sectional views excluding the insulating layer 125. In Figure 3A, the resin layer 126 is disposed in contact with the sides of a pair of organic layers 115, the sides of organic layer 112R, the sides of organic layer 112G, the sides of layer 135R, the sides of layer 135G, and the sides of a pair of organic layers 116. In Figure 3B, the resin layer 126 is disposed in contact with the sides of organic layer 155 and the sides of layer 135S.

[0106] At this time, sometimes a portion of the EL layer or PD layer may dissolve due to the solvent used in forming the film that will become the resin layer 126. Therefore, when the insulating layer 125 is not provided, it is preferable to use water, or alcohols such as ethyl alcohol, methyl alcohol, isopropyl alcohol (IPA), or glycerol as the solvent for the resin layer 126. Note that this is not a limitation; any solvent that does not dissolve or does not readily dissolve the EL layer and PD layer may be used.

[0107] As described above, a display device according to one embodiment of the present invention can employ a structure without an insulator covering the ends of the pixel electrodes. In other words, a structure without an insulator between the pixel electrodes and the EL layer can be adopted. By employing this structure, light emission from the EL layer can be effectively extracted, resulting in minimal viewing angle dependence. For example, in a display device according to one embodiment of the present invention, the viewing angle (the maximum angle at which a certain contrast is maintained when viewing the screen from an oblique angle) can be in the range of 100° or more and less than 180°, preferably 150° or more and less than 170°. Furthermore, the above-mentioned viewing angle can be used in all directions. By employing a display device according to one embodiment of the present invention, the viewing angle characteristics are improved, and the visibility of the image can be improved.

[0108] [Modified Examples] Figures 4A and 4B are modified examples of Figures 2A and 2B, respectively. Figures 4A and 4B show examples of cases where an insulating layer 131 covering the end of the pixel electrode is provided.

[0109] The insulating layer 131 has the function of planarizing the surface on which the organic layer 115 is formed. The ends of the insulating layer 131 are preferably tapered. Furthermore, by using an organic resin in the insulating layer 131, its surface can have a gentle curve. Therefore, the coverage of the film formed on the insulating layer 131 can be improved. In addition, the insulating layer 131 has the function of preventing unintentional short circuits between two adjacent pixel electrodes 111. Furthermore, when a metal mask is used during the formation of the organic layer 112, organic layer 155, etc., the insulating layer 131 can also serve as a spacer to prevent the pixel electrodes 111 from contacting the metal mask.

[0110] 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.

[0111] As shown in Figures 4A and 4B, the insulating layer 131 may also have a recess in the region overlapping with the slit 120. This recess is formed because a portion of the top of the insulating layer 131 is etched during the etching process used to form the slit 120. Because a portion of the insulating layer 125 is formed in this recess of the insulating layer 131, their adhesion can be improved.

[0112] The slit 120 is provided in the region overlapping the insulating layer 131. In addition, layers 135R, 135G and 135S are also provided in the region overlapping the insulating layer 131.

[0113] Figures 4A and 4B show examples of layers 135R, 135G and 135S extending beyond the end of the insulating layer 131 on the opposite side of the slit 120.

[0114] Figures 5A and 5B are examples of the case where an insulating layer 132 is provided on the insulating layer 131.

[0115] An insulating layer 132 overlaps the end of the pixel electrode 111, passing over an insulating layer 131. Furthermore, the insulating layer 132 covers the end of the insulating layer 131. Additionally, the insulating layer 132 has a portion that contacts the top surface of the pixel electrode 111.

[0116] Preferably, the end of the insulating layer 132 has a tapered shape. This improves the step coverage of the film formed on the insulating layer 132, such as the EL layer, which is disposed at the end of the insulating layer 132.

[0117] In addition, the thickness of the insulating layer 132 is preferably thinner than that of the insulating layer 131. By forming a thinner insulating layer 132, the step coverage of the film formed on the insulating layer 132 can be improved.

[0118] As an inorganic insulating material that can be used in insulating layer 132, oxides or nitrides such as silicon oxide, silicon oxynitride, silicon oxynitride, silicon nitride, aluminum oxide, aluminum oxynitride, or hafnium oxide can be used. In addition, yttrium oxide, zirconium oxide, gallium oxide, tantalum oxide, magnesium oxide, lanthanum oxide, cerium oxide, and neodymium oxide can also be used.

[0119] Alternatively, the insulating layer 132 may also be laminated with a film containing the aforementioned inorganic insulating material. For example, a laminated structure in which a silicon oxide film or a silicon oxynitride film is laminated on a silicon nitride film, or a laminated structure in which a silicon oxide film or a silicon oxynitride film is laminated on an aluminum oxide film, etc. Silicon oxide film and silicon oxynitride film are films that are particularly difficult to etch, so they are preferably disposed on the upper side. In addition, silicon nitride film and aluminum oxide film are films that do not easily allow water, hydrogen, oxygen, etc. to diffuse, so by being disposed on the insulating layer 131 side, they are used as a barrier layer to prevent gases detached from the insulating layer 131 from diffusing into the light-emitting element.

[0120] Slit 120 is provided in the region overlapping the insulating layer 132. In addition, layers 135R, 135G and 135S are also provided in the region overlapping the insulating layer 132.

[0121] By providing the insulating layer 132, the top surface of the insulating layer 131 can be prevented from being etched when the slit 120 is formed.

[0122] Figures 5A and 5B show examples of layers 135R, 135G and 135S extending beyond the ends of insulating layer 131 and insulating layer 132 on the opposite side of slit 120.

[0123] [Structure Example 2] The following describes a more specific structural example.

[0124] FIG6A is a cross-sectional schematic diagram of the display device illustrated below. FIG6A shows a cross-section of the area including the light-emitting element 110R, the light-emitting element 110G, the light-emitting element 110B, the light-receiving element 110S, and the connecting portion 130. In addition, FIG6B is an enlarged cross-sectional schematic diagram of the slit 120 and its vicinity located between the light-emitting element 110R and the light-emitting element 110G.

[0125] The light-emitting element 110B includes a pixel electrode 111B, an organic layer 115, an organic layer 112B, an organic layer 116, an organic layer 114, and a common electrode 113. In the structure shown in FIG6A, a portion (fragment) of the organic layer 112B divided by the slit 120 is disposed near the light-emitting element 110R and near the light-receiving element 110S.

[0126] A conductive layer 161, a conductive layer 162, and a resin layer 163 are disposed below the pixel electrode 111.

[0127] A conductive layer 161 is disposed on an insulating layer 105. The conductive layer 161 has a portion penetrating the insulating layer 105 in an opening disposed in the insulating layer 105. The conductive layer 161 is used to electrically connect wiring, transistors, or electrodes (not shown) located below the insulating layer 105 to wiring or electrodes of the pixel electrode 111.

[0128] A recess is formed in the portion of the conductive layer 161 located at the opening of the insulating layer 105. The resin layer 163 is provided to fill the recess and is used as a planarization film. The flatter the top surface of the resin layer 163, the better, but sometimes it is a gently curved shape. Figure 6A shows an example of a wavy shape with recesses and convexities on the top surface of the resin layer 163, but it is not limited to this. For example, the top surface of the resin layer 163 can be a convex surface, a concave surface, or a plane.

[0129] A conductive layer 162 is provided on the conductive layer 161 and the resin layer 163. The conductive layer 162 is used as an electrode for electrically connecting the conductive layer 161 and the pixel electrode 111.

[0130] Here, when the light-emitting element 110 is a top-emitting type light-emitting element, by using a film that is reflective to visible light as the conductive layer 162 and a film that is transmissive to visible light as the pixel electrode 111, the conductive layer 162 can be used as a reflective electrode. Furthermore, since the conductive layer 162 and the pixel electrode 111 can also be disposed on top of the opening (also called the contact portion) of the insulating layer 105 across the resin layer 163, the portion overlapping the contact portion can also be a light-emitting area. Therefore, the aperture ratio can be improved.

[0131] Similarly, when the light-receiving element 110S is used as a photoelectric conversion element for receiving light from above, a reflective film can be used for the conductive layer 162 and a light-transmitting film can be used for the pixel electrode 111. Furthermore, since the contact portion can also be used as a light-receiving area, the light-receiving area is increased and the light-receiving sensitivity can be improved.

[0132] Alternatively, the thickness of each pixel electrode 111 can be different. In this case, the pixel electrode 111 can be used as the optical adjustment layer of the microcavity. When using the microcavity, a translucent and reflective film is used as a common electrode.

[0133] Figures 6A and 6B show examples where the shape of the resin layer 126 differs from that described above.

[0134] As shown in FIG. 6B, the top of the resin layer 126 has a shape whose width is greater than the width of the slit 120. As described later, the insulating layer 125 is processed with the resin layer 126 as an etching mask, so a portion covered by the top of the resin layer 126 remains. Furthermore, a portion of the sacrificial layer 145 used in the manufacturing process of the display device also remains for the same reason. Specifically, the sacrificial layer 145 is provided on the organic layer 116 near the slit 120. Additionally, a portion of the insulating layer 125 is provided to cover the top surface of the sacrificial layer 145. Furthermore, the resin layer 126 is provided to cover both the sacrificial layer 145 and the insulating layer 125.

[0135] At this time, the ends of the insulating layer 125 and the sacrificial layer 145 are preferably tapered. This can improve the step coverage of the organic layer 114, etc.

[0136] As shown in Figures 6A and 6B, layers 135R, 135G, 135B, and 135S are all in contact with the insulating layer 125 and have regions that overlap with the insulating layer 125, the sacrificial layer 145, and the resin layer 126. Furthermore, layers 135R, 135G, 135B, and 135S each have portions that overlap with the pixel electrodes of adjacent light-emitting or light-receiving elements.

[0137] FIG7 shows a cross-sectional schematic diagram of the connecting portion 140 and its vicinity. FIG7 shows an example in which the connecting portion 140 is provided between the light-emitting element 110R and the light-receiving element 110S. Note that although an example in which the connecting portion 140 is provided between the light-emitting element 110R and the light-receiving element 110S is shown here, it is not limited to this, and it may also be provided between the light-emitting element 110G and the light-receiving element 110S or between the light-emitting element 110B and the light-receiving element 110S.

[0138] A conductive layer 161, a resin layer 163, and a conductive layer 162 are stacked in the connecting portion 140. An electrode 111A is disposed on the conductive layer 162. The electrode 111A is surrounded by an insulating layer 125 and a resin layer 126. In addition, the resin layer 126 and the insulating layer 125 have openings that overlap with the electrode 111A, in which the electrode 111A is disposed in contact with the organic layer 114. The electrode 111A and the common electrode 113 are electrically connected through the organic layer 114.

[0139] Preferably, organic layers 115, 112R, 112G, 112B, 155, and 116 are not provided on electrode 111A. Furthermore, it is preferable that layers 135R, 135G, 135B, and 135S are not provided on electrode 111A.

[0140] Furthermore, the connecting portion 140 can be formed using the same method as the connecting portion 130. Note that the connecting portion 140 and the connecting portion 130 may have different cross-sectional shapes (e.g., the thickness or width of the component) even when formed using the same method, due to the different shapes of the surrounding steps.

[0141] [Example of Manufacturing Method] Hereinafter, an example of a method for manufacturing a display device according to an embodiment of the present invention will be described with reference to the drawings. The display device shown in FIG. 6A above will be used as an example for description. FIGS. 8A to 11C are cross-sectional schematic diagrams of each process in the following example of the manufacturing method of the display device. Furthermore, a cross-sectional schematic diagram of the connecting portion 130 and its vicinity is also shown on the right side of FIG. 8A, etc.

[0142] Thin films (insulating films, semiconductor films, conductive films, etc.) constituting display devices can be formed using sputtering, chemical vapor deposition (CVD), vacuum evaporation, pulsed laser deposition (PLD), atomic layer deposition (ALD), and other methods. CVD methods include plasma-enhanced chemical vapor deposition (PECVD) and thermal CVD. Furthermore, as a type of thermal CVD, metal-organic chemical vapor deposition (MOCVD) is also used.

[0143] In addition, the thin film (insulating film, semiconductor film, conductive film, etc.) constituting the display device can be formed by methods such as spin coating, dip coating, spray coating, inkjet coating, dispenser coating, screen printing, flatbed printing, doctor knife coating, slot coating, roller coating, curtain coating, and doctor knife coating.

[0144] Furthermore, when processing the thin film constituting the display device, it can be processed using methods such as photolithography. In addition to the methods mentioned above, the thin film can also be processed using nanoimprinting, sandblasting, or peeling. Furthermore, island-shaped thin films can be directly formed using shadow mask deposition methods such as metal masks.

[0145] Photolithography typically includes two methods. One method involves forming a photoresist mask on the film to be processed, processing the film by etching, and then removing the photoresist mask. The other method involves depositing a photosensitive film, followed by exposure and development to process the film into the desired shape.

[0146] In photolithography, the light used for exposure can be, for example, i-line (wavelength 365nm), g-line (wavelength 436nm), h-line (wavelength 405nm), or a mixture of these. Additionally, ultraviolet light, KrF laser, or ArF laser can also be used. Furthermore, immersion exposure technology can be used. Additionally, extreme ultraviolet (EUV) light or X-rays can be used as the light for exposure. Alternatively, an electron beam can be used instead of the light used for exposure. When using extreme ultraviolet light, X-rays, or an electron beam, extremely fine processing can be performed, making it preferable. Note that when exposure is performed by scanning with a beam such as an electron beam, a photomask is not required.

[0147] As a method for etching thin films, dry etching, wet etching and sandblasting can be used.

[0148] [Preparation of Substrate 101] As substrate 101, a substrate with heat resistance sufficient to withstand subsequent heat treatment can be used. When using an insulating substrate as substrate 101, glass substrate, quartz substrate, sapphire substrate, ceramic substrate, organic resin substrate, etc., can be used. In addition, single-crystal semiconductor substrates or polycrystalline semiconductor substrates made of materials such as silicon or silicon carbide, compound semiconductor substrates made of materials such as silicon and germanium, SOI substrates, etc., can also be used.

[0149] In particular, the substrate 101 is preferably a substrate on which a semiconductor circuit including semiconductor elements such as transistors is formed on the aforementioned semiconductor substrate or insulating substrate. This semiconductor circuit is preferably, for example, a pixel circuit, a gate line drive circuit (gate driver), a source line drive circuit (gate driver), etc. In addition, it can also be configured as an arithmetic circuit, a memory circuit, etc.

[0150] An insulating layer 105 is provided at the top of the substrate 101. Multiple openings are provided in the insulating layer 105 to reach transistors, wiring, electrodes, etc. provided in the substrate 101. These openings can be formed by photolithography.

[0151] Inorganic or organic insulating materials can be used as the insulating layer 105.

[0152] [Formation of conductive layer 161, resin layer 163, conductive layer 162, and pixel electrode 111] A conductive film that will become conductive layer 161 is deposited on insulating layer 105. At this time, a recess is formed in the conductive film due to the opening in insulating layer 105.

[0153] Next, a resin layer 163 is formed on the recess of the conductive film.

[0154] A photosensitive resin is preferably used as the resin layer 163. In this case, a resin film is first deposited, then exposed to a photomask, and then developed to form the resin layer 163. Then, the top of the resin layer 163 can be etched by means of ashing to adjust the top surface height of the resin layer 163.

[0155] In addition, when a non-photosensitive resin is used as resin layer 163, after depositing the resin film, the top of the resin film is etched by ashing or the like until the surface of the conductive film that will become conductive layer 161 is exposed, so that the thickness of the resin layer is most suitable, thereby forming resin layer 163.

[0156] Next, a conductive film that will become conductive layer 162 is deposited on the conductive film that will become conductive layer 161 and the resin layer 163. Then, a photoresist mask is formed on the two conductive films by photolithography, and unwanted parts of the conductive film are removed by etching. Then, the photoresist mask is removed, thereby forming conductive layer 161 and conductive layer 162 in the same process.

[0157] Here, the same photomask is used to form conductive layer 161 and conductive layer 162 in the same process, but different photomasks can also be used to form conductive layer 161 and conductive layer 162 respectively. In this case, it is preferable that conductive layer 161 and conductive layer 162 are processed in such a way that conductive layer 161 is included inside the contour of conductive layer 162 when viewed from above.

[0158] Next, a conductive film is formed by covering conductive layer 161 and conductive layer 162, and a portion of the conductive film is removed by etching, thereby forming pixel electrode 111 and connection electrode 111C (FIG. 8A). At this time, as shown in FIG. 8A, it is preferable to form pixel electrode 111 and connection electrode 111C in a manner including conductive layer 161 and conductive layer 162, so that conductive layer 161 and conductive layer 162 are not exposed to the etching atmosphere during the formation of pixel electrode 111, etc.

[0159] [Formation of Organic Layer 115] Next, an organic layer 115 is deposited on the pixel electrode 111 (FIG. 8B). Preferably, the organic layer 115 is deposited without using an FMM.

[0160] Note that FMM can also be used to form organic layer 115 separately. In this case, please refer to the description of organic layer 112R, etc. later.

[0161] The organic layer 115 is preferably formed using a vacuum evaporation method. Alternatively, it can be formed using sputtering or inkjet printing. Furthermore, it is not limited to these methods; the above-described deposition methods can be used appropriately.

[0162] [Formation of organic layer 112R, organic layer 112G, organic layer 112B and organic layer 155] Next, an island-shaped organic layer 112R is formed in such a way that it includes the region on organic layer 115 and overlaps with pixel electrode 111R.

[0163] In this case, the organic layer 112R is formed in a manner that overlaps with one or more of the pixel electrodes 111G, 111B, and 111S of adjacent pixels. By forming organic layers 112R and the like not only between organic layers, but also by overlapping organic layers with the pixel electrodes of adjacent pixels, the spacing between pixel electrodes can be reduced, thereby enabling the high-density arrangement of light-emitting elements and light-receiving elements.

[0164] The organic layer 112R is preferably formed by vacuum evaporation using an FMM. Alternatively, the island-shaped organic layer 112R can also be formed using sputtering or inkjet printing with an FMM.

[0165] Figure 8C shows the deposition of organic layer 112R using FMM151R. Figure 8C shows the deposition using a so-called facedown method, in which the substrate is inverted with the surface to be formed facing down.

[0166] In methods such as evaporation deposition using an open-circuit membrane (FMM), the deposition often occurs over an area larger than the opening pattern of the FMM. Therefore, as shown by the dashed line in FIG8C, even if an FMM 151R with the same opening pattern as the pixel electrode 111R is used, the organic layer 112R can be deposited in the region between the pixel electrode 111R and the pixel electrode adjacent to it. Here, the organic layer 112R is also formed on adjacent pixel electrodes 111G and 111S.

[0167] Next, an organic layer 112G is formed on the pixel electrode 111G using an FMM151G (FIG 9A). Here, the organic layer 112G is also formed on adjacent pixel electrodes 111R and 111B.

[0168] Similar to organic layer 112R, organic layer 112G can also be formed with a pattern extending to the outside of pixel electrode 111G. As a result, as shown in region RG in FIG9A, a portion of organic layer 112G can be formed on organic layer 112R.

[0169] Next, an organic layer 112B is formed on the pixel electrode 111B using an FMM151B (not shown). Then, an organic layer 155 is formed on the pixel electrode 111S using an FMM151S.

[0170] Similar to organic layers 112R and 112G, organic layers 112B and 155 are also formed with patterns extending to the outside of pixel electrode 111B or pixel electrode 111S. As a result, as shown in FIG9B, a region GB on organic layer 112G where organic layer 112B is stacked, a region BS on organic layer 112B where organic layer 155 is stacked, and a region RS on organic layer 112R where organic layer 155 is stacked are formed. In addition, although not shown here, regions such as regions on organic layer 112G where organic layer 155 is stacked and regions on organic layer 112R where organic layer 112B is stacked are also formed.

[0171] Preferably, organic layers 112R, 112G, 112B and 155 are not formed on the connecting electrode 111C. FIG9B shows an example in which organic layer 115 is formed on the connecting electrode 111C but organic layers 112R, 112G and 112B are not formed.

[0172] Here, organic layer 112R, organic layer 112G, organic layer 112B and organic layer 155 are formed in that order, but the order of formation is not limited to this.

[0173] [Formation of Organic Layer 116] Next, organic layer 116 is formed by covering organic layer 112R, organic layer 112G, organic layer 112B and organic layer 155 (Fig. 9C). Organic layer 116 can be formed in the same way as organic layer 115.

[0174] [Formation of sacrificial membrane 144] Next, an organic layer 116 is applied to form a sacrificial membrane 144.

[0175] The sacrificial film 144 can be a film with high resistance to etching of organic layers 115, 112, 155, and 116, that is, a film with a large etch selectivity. Furthermore, the sacrificial film 144 can be a film with a large etch selectivity compared to sacrificial films such as sacrificial film 146 described later. Moreover, the sacrificial film 144 is particularly preferably a film that can be removed by a wet etching method that causes minimal damage to organic layers 115, 112, 155, and 116.

[0176] As the sacrificial film 144, inorganic films such as metal films, alloy films, metal oxide films, semiconductor films, and inorganic insulating films can be appropriately used. The sacrificial film 144 is formed by various deposition methods such as sputtering, evaporation, CVD, and ALD.

[0177] In particular, since the ALD method causes little damage to the deposition of the formed layer, the sacrificial film 144 formed directly on the organic layer 116 is preferably formed using the ALD method.

[0178] As the sacrificial film 144, for example, metallic materials such as gold, silver, platinum, magnesium, nickel, tungsten, chromium, molybdenum, iron, cobalt, copper, palladium, titanium, aluminum, yttrium, zirconium, and tantalum, or alloy materials containing such metallic materials, can be used. Low-melting-point materials such as aluminum or silver are particularly preferred.

[0179] Additionally, indium gallium zinc oxide (In-Ga-Zn oxide, also denoted as IGZO) or other metal oxides can be used as the sacrificial film 144. Furthermore, indium oxide, indium zinc oxide (In-Zn oxide), indium tin oxide (In-Sn oxide), indium titanium oxide (In-Ti oxide), indium tin zinc oxide (In-Sn-Zn oxide), indium titanium zinc oxide (In-Ti-Zn oxide), indium gallium tin zinc oxide (In-Ga-Sn-Zn oxide), etc., can also be used. Alternatively, indium tin oxide containing silicon, etc., can also be used.

[0180] Note that this can also be applied to cases where element M (M is one or more of aluminum, silicon, boron, yttrium, tin, copper, vanadium, beryllium, titanium, iron, nickel, germanium, zirconium, molybdenum, lanthanum, cerium, neodymium, hafnium, tantalum, tungsten, and magnesium) is used instead of gallium. In particular, M is preferably one or more of gallium, aluminum, and yttrium.

[0181] In addition, the sacrificial film 144 can be made of oxides such as alumina, hafnium oxide, and silicon oxide, nitrides such as silicon nitride and aluminum nitride, or oxynitrides such as silicon oxynitride. Such inorganic insulating materials can be formed by deposition methods such as sputtering, CVD, or ALD.

[0182] As the sacrificial film 144, a material soluble in a solvent that is chemically stable at least to the uppermost organic layer 116 of the EL layer can also be used. In particular, a material soluble in water or alcohol can be suitably used for the sacrificial film 144. When depositing the sacrificial film 144, it is preferable to coat it by a wet deposition method in a solvent such as water or alcohol, followed by a heat treatment to evaporate the solvent. In this case, it is preferable to perform the heat treatment under a reduced pressure atmosphere, thereby removing the solvent at a low temperature and for a short time, and reducing thermal damage to the EL layer.

[0183] As wet deposition methods used to form the sacrificial film 144, there are spin coating, dip coating, spray coating, inkjet coating, dispenser coating, screen printing, flatbed printing, doctor knife coating, slot coating, roller coating, curtain coating, and doctor knife coating.

[0184] As the sacrificial membrane 144, organic materials such as polyvinyl alcohol (PVA), polyvinyl butyral, polyvinylpyrrolidone, polyethylene glycol, polyglycerol, pullulan, water-soluble cellulose, or alcohol-soluble polyamide resin can be used.

[0185] [Formation of sacrificial membrane 146] Next, sacrificial membrane 146 is formed on sacrificial membrane 144.

[0186] The sacrificial film 146 is used as a hard mask when the sacrificial film 144 is subsequently etched. Furthermore, the sacrificial film 144 is exposed during the subsequent processing of the sacrificial film 146. Therefore, a combination of films with a greater etching selectivity is selected between the sacrificial film 144 and the sacrificial film 146. Thus, the film suitable for use as the sacrificial film 146 can be selected based on the etching conditions of both the sacrificial film 144 and the sacrificial film 146.

[0187] The sacrificial film 146 can be selected from various materials depending on the etching conditions of the sacrificial film 144 and the etching conditions of the sacrificial film 146. For example, it can be selected from films that can be used in the sacrificial film 144 described above.

[0188] For example, an oxide film can be used as the sacrificial film 146. Typically, oxide films or oxynitride films such as silicon oxide, silicon oxynitride, aluminum oxide, aluminum oxynitride, hafnium oxide, and hafnium oxynitride can also be used.

[0189] In addition, as the sacrificial film 146, a nitride film can be used, for example. Specifically, silicon nitride, aluminum nitride, hafnium nitride, titanium nitride, tantalum nitride, tungsten nitride, gallium nitride, germanium nitride, and other nitrides can be used.

[0190] For example, preferably, an inorganic insulating material such as alumina, hafnium oxide, or silicon oxide formed by the ALD method is used as the sacrificial film 144, and an indium-containing metal oxide such as indium gallium zinc oxide (also referred to as In-Ga-Zn oxide or IGZO) formed by sputtering is used as the sacrificial film 146. Alternatively, the sacrificial film 146 is preferably made of metals such as tungsten, molybdenum, copper, aluminum, titanium, and tantalum, or alloys containing such metals.

[0191] Alternatively, an organic film suitable for organic layers 115, 112, 155, and 116 can be used as the sacrificial film 146. For example, the same organic film used for organic layers 115, 112, 155, or 116 can be used as the sacrificial film 146. By using such an organic film, the deposition apparatus can be used together with organic layers 115, 112, 155, and 116, which is preferable. Furthermore, when etching organic layers 115, 112, 155, and 116 using the subsequent sacrificial layer as a mask, the sacrificial layer can be removed simultaneously, thus simplifying the process.

[0192] [Formation of photoresist mask 143] Next, photoresist masks 143 are formed on the sacrificial film 146 at positions overlapping with pixel electrodes 111R, 111G, 111B, and 111S (FIG. 10A). In this case, no photoresist mask is formed at the position overlapping with the connecting electrode 111C. Furthermore, when electrode 111A is formed, it is preferable that no photoresist mask is formed at the position overlapping with electrode 111A.

[0193] The photoresist mask 143 can be a photoresist material containing a photosensitive resin, such as a positive photoresist material or a negative photoresist material.

[0194] Here, when a photoresist mask 143 is formed on a sacrificial film 144 without the sacrificial film 146, if there are defects such as pinholes in the sacrificial film 144, the organic layers 115, 112, 155, and 116 may dissolve due to the solvent of the photoresist material. By using the sacrificial film 146, this defect can be prevented.

[0195] Note that when the solvent used as the photoresist material is a material that does not dissolve organic layer 115, organic layer 112, organic layer 155 and organic layer 116, the photoresist mask 143 may sometimes be formed directly on the sacrificial film 144 without using the sacrificial film 146.

[0196] [Etching of sacrificial film 146] Next, a strip sacrificial layer 147 is formed by etching away a portion of the sacrificial film 146 that is not covered by the photoresist mask 143.

[0197] When etching the sacrificial film 146, it is preferable to use etching conditions with a high selectivity to prevent the sacrificial film 144 from being removed by the etching. The etching of the sacrificial film 146 can be performed by wet etching or dry etching, but by using dry etching, the pattern shrinkage of the sacrificial layer 147 can be suppressed.

[0198] [Removal of photoresist mask 143] Next, remove photoresist mask 143.

[0199] The removal of the photoresist mask 143 can be performed using wet etching or dry etching. It is particularly preferred that the photoresist mask 143 be removed using dry etching (also known as plasma ashing) that uses oxygen gas as the etching gas.

[0200] At this time, since the removal of the photoresist mask 143 is performed while the organic layer 116 is covered by the sacrificial film 144, the effects on the organic layers 115, 112, 155, and 116 are suppressed. In particular, when the organic layers 115, 112, 155, and 116 are exposed to oxygen, it can sometimes negatively affect their electrical properties, so this is preferable when performing etching using oxygen gas, such as plasma ashing. Furthermore, when the photoresist mask 143 is removed by wet etching, since the organic layers 116 are not exposed to the solution, the dissolution of the organic layers 116 can also be prevented.

[0201] [Etching of sacrificial film 144] Next, the sacrificial layer 147 is used as a hard mask and a portion of the sacrificial film 144 is removed by etching to form the sacrificial layer 145 (Fig. 10B).

[0202] The etching of the sacrificial film 144 can be performed by wet etching or dry etching, but dry etching is preferred, thereby suppressing the shrinkage of the pattern.

[0203] [Etching of organic layers 116, 112, 155, and 115] Next, a portion of organic layers 116, 112, 155, and 115 not covered by the sacrificial layer 145 is removed by etching to form a slit 120. Simultaneously, the top surface of the connecting electrode 111C is exposed. Furthermore, in the case of forming electrode 111A, the top surface of electrode 111A is also exposed.

[0204] At this time, by etching organic layer 112R, organic layer 112G, organic layer 112B and a portion of organic layer 155 are divided to form layer 135R of fragments of organic layer 112R, layer 135G of fragments of organic layer 112G, layer 135B of fragments of organic layer 112B and layer 135S of fragments of organic layer 155.

[0205] In particular, the etching of organic layers 116, 112, 155, and 115 is preferably performed by dry etching using an etching gas whose main component does not contain oxygen. This suppresses the deterioration of organic layers 116, 112, 155, and 115, enabling a display device with high reliability. Examples of etching gases whose main component does not contain oxygen include CF4, C4F8, SF6, CHF3, Cl2, H2O, BCl3, H2, or rare gases such as He. Alternatively, a mixture of the above gases and an oxygen-free diluent gas can be used as the etching gas.

[0206] Note that the etching of organic layer 116, organic layer 112, organic layer 155 and organic layer 115 is not limited to the above method. It can be carried out by dry etching using other gases or by wet etching.

[0207] Furthermore, when dry etching is performed using an oxygen gas or a mixture containing an oxygen gas as the etching gas for etching organic layers 116, 112, 155, and 115, the etching rate can be increased. This allows etching to be performed at low power while maintaining a sufficiently high etching rate, thus reducing etching-related damage. Furthermore, it suppresses defects such as the adhesion of reaction products that occur during etching. For example, as the etching gas, a mixture of etching gas containing oxygen gas added to an etching gas whose main components do not contain oxygen can be used.

[0208] When the organic layers 116, 112, 155, and 115 are etched, the insulating layer 105 is exposed. Therefore, it is preferable to use a film with high resistance to etching of the organic layer 115 as the insulating layer 105. Note that during the etching of the organic layer 115, sometimes the top of the insulating layer 105 is etched and not partially thinned by the organic layer 115.

[0209] Alternatively, the sacrificial layer 147 can be etched simultaneously with the etching of organic layer 116, organic layer 112, organic layer 155, or organic layer 115. By etching organic layer 116, organic layer 112, organic layer 155, or organic layer 115 and sacrificial layer 147 in the same process, the manufacturing process can be simplified and the manufacturing cost of the display device can be reduced, which is therefore preferable.

[0210] [Removal of Sacrificial Layer] Next, the sacrificial layer 147 is removed, exposing the top surface of the sacrificial layer 145 (Fig. 10C). At this point, the sacrificial layer 145 is preferably remaining. Alternatively, the sacrificial layer 147 may not be removed at this point.

[0211] [Formation of insulating film 125f] Next, insulating film 125f is deposited over the sacrificial layer 145 and the slit 120.

[0212] The insulating film 125f is used as a barrier layer to prevent impurities such as water from diffusing into the EL layer. The insulating film 125f is preferably formed using the ALD method, which has excellent step coverage, thereby appropriately covering the sides of the EL layer.

[0213] Preferably, the insulating film 125f is the same film as the sacrificial layer 145, so that etching can be performed simultaneously in subsequent processes. For example, it is preferable to use inorganic insulating materials such as alumina, hafnium oxide, and silicon oxide formed by the ALD method for the insulating film 125f and the sacrificial layer 145.

[0214] Note that the materials that can be used for insulating film 125f are not limited to this, and materials that can be used for the above-mentioned sacrificial film 144 can be used appropriately.

[0215] [Formation of Resin Layer 126] Next, a resin layer 126 is formed in the region overlapping the slit 120 (FIG. 11A). The resin layer 126 can be formed in the same way as the resin layer 163. For example, the resin layer 126 can be formed by exposure and development after the formation of the photosensitive resin. Alternatively, the resin layer 126 can be formed by etching a portion of the resin after the resin is formed on the entire surface using an ashing process.

[0216] Here, an example is shown in which the resin layer 126 is formed in such a way that its width is greater than the width of the slit 120.

[0217] The resin layer 126 is provided in a manner that does not cover the connecting electrode 111C. When forming the electrode 111A, the resin layer 126 is formed in a manner that does not cover the top surface of the electrode 111A at all.

[0218] [Etching of insulating film 125f and sacrificial layer 145] Next, the portions of insulating film 125f and sacrificial layer 145 not covered by resin layer 126 are removed by etching, exposing the top surface of organic layer 116. Thus, insulating layer 125 and sacrificial layer 145 are formed simultaneously in the area covered by resin layer 126 (FIG. 11B).

[0219] Preferably, the insulating film 125f and the sacrificial layer 145 are etched using the same process. In particular, the etching of the sacrificial layer 145 is preferably performed by wet etching, which causes less etch damage to the organic layer 116. For example, it is preferable to use wet etching with an aqueous solution of tetramethylammonium hydroxide (TMAH), dilute hydrofluoric acid, oxalic acid, phosphoric acid, acetic acid, nitric acid, or a mixture thereof.

[0220] Alternatively, preferably, either or both of the insulating film 125f and the sacrificial layer 145 can be removed by dissolving them in a solvent such as water or alcohol. Here, various alcohols such as ethanol, methanol, isopropanol (IPA), or glycerol can be used as the alcohol that can dissolve the insulating film 125f and the sacrificial layer 145.

[0221] To remove water contained within organic layers 115, 112, 155, and 116, and water adsorbed on the surface, after removing the insulating film 125f and the sacrificial layer 145, a drying process is preferably performed. For example, it is preferable to perform the heating process under an inactive gas atmosphere or a reduced pressure atmosphere. In the heating process, the substrate temperature can be above 50°C and below 200°C, preferably above 60°C and below 150°C, and more preferably above 70°C and below 120°C. By using a reduced pressure atmosphere, drying can be performed at a lower temperature, which is preferable.

[0222] By removing the insulating film 125f and the sacrificial layer 145, the top surface of the connecting electrode 111C is exposed. In addition, when the electrode 111A is formed, the top surface of the electrode 111A is exposed.

[0223] [Formation of organic layer 114] Next, organic layer 114 is deposited, including covering organic layer 116, insulating layer 125, sacrificial layer 145 and resin layer 126.

[0224] The organic layer 114 can be deposited using the same method as the organic layer 115. When depositing the organic layer 114 using the vapor deposition method, a shadow mask deposition method can also be used to prevent the organic layer 114 from being deposited on the connecting electrode 111C.

[0225] [Formation of common electrode 113] Next, the common electrode 113 is formed by covering the organic layer 114.

[0226] The common electrode 113 can be formed by deposition methods such as vapor deposition or sputtering. Alternatively, a film formed by vapor deposition and a film formed by sputtering can be stacked.

[0227] The common electrode 113 is preferably formed in a manner that includes a region containing the deposited organic layer 114. That is, the end of the organic layer 114 may overlap with the common electrode 113. The common electrode 113 may also be formed using a shadow mask.

[0228] In FIG11C, an example is shown where an organic layer 114 is sandwiched between the connecting electrode 111C and the common electrode 113 as the connection portion 130. In this case, it is preferable to use a material with the lowest possible resistance as the organic layer 114. Alternatively, by forming it as thin as possible, it is preferable to reduce the resistance in the thickness direction of the organic layer 114. For example, by using an electron-injecting or hole-injecting material with a thickness of 1 nm or more and 5 nm or less, preferably 1 nm or more and 3 nm or less, as the organic layer 114, it is sometimes possible to make the resistance between the connecting electrode 111C and the common electrode 113 so small as to be negligible.

[0229] Similarly, when the connecting part 140 is provided, an organic layer 114 is sandwiched between the electrode 111A and the common electrode 113.

[0230] [Formation of Protective Layer] Next, a protective layer 121 (FIG. 11C) is formed on the common electrode 113. When depositing the inorganic insulating film for the protective layer 121, sputtering, PECVD, or ALD methods are preferred. In particular, ALD is preferred because it provides good step coverage and is less prone to defects such as pinholes. Alternatively, when depositing an organic insulating film, inkjet printing is preferred because it allows for uniform film formation in the desired area.

[0231] The display device shown in FIG6A can be manufactured by the above process.

[0232] Note that the above shows an example in which the resin layer 126 is formed with its width being greater than the width of the slit 120, but the resin layer 126 may also be formed with its width being the same as the width of the slit 120.

[0233] Figure 12A is a cross-sectional view at the point when the resin layer 126 is formed after the insulating film 125f is formed.

[0234] For example, as shown in FIG11A, by forming a resin layer 126 whose width is greater than that of the slit 120 and then etching the top of the resin layer 126 using ashing or the like, the resin layer 126 can be formed only inside the slit 120. In this case, it is preferable to make the height of the top surface of the resin layer 126 as consistent as possible with the height of the top surface of the adjacent organic layer 116. As a result, the overlap with the portion of the slit 120 and the steps at its two ends can be reduced, and the step coverage of the organic layer 114, etc., can be improved.

[0235] Next, the insulating film 125f and the sacrificial layer 145 are etched in the same manner as described above (Fig. 12B). At this time, since the portion of the sacrificial layer 145 not covered by the resin layer 126 is removed, the sacrificial layer 145 is removed without leaving any fragments.

[0236] Next, by forming the organic layer 114, the common electrode 113 and the protective layer 121 in the same manner as described above, the display device can be manufactured as shown in FIG12C.

[0237] Additionally, Figure 12C shows an example where the organic layer 114 is not provided between the connecting electrode 111C and the common electrode 113. Because the connecting electrode 111C is in contact with the common electrode 113, the contact resistance between them can be minimized, thereby reducing power consumption.

[0238] The above is an explanation of an example of a manufacturing method for a display device.

[0239] At least a portion of this embodiment may be implemented in combination with other embodiments described in this specification.

[0240] 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. Here, it will be described as a display device that can display images, but the light-emitting element can also be used as a display device by being used as a light source.

[0241] Furthermore, the display device of this embodiment can be a high-resolution display device or a large-screen display device. Therefore, the display device of this embodiment can also 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.

[0242] [Light-emitting device 400] FIG13 shows a perspective view of the light-emitting device 400, and FIG14A shows a cross-sectional view of the light-emitting device 400.

[0243] The display device 400 has a structure that attaches a substrate 452 and a substrate 451. In FIG13, the substrate 452 is indicated by a dashed line.

[0244] 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 14 can also be referred to as a display module including the display device 400, the IC (integrated circuit), and the FPC.

[0245] As circuit 464, for example, a scan line drive circuit can be used.

[0246] 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.

[0247] Figure 13 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.

[0248] FIG14A 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. FIG14A particularly shows an example of a cross-section of the region of the display section 462 including the light-emitting element 430b that emits green light (G) and the light-receiving element 440 that receives reflected light (L).

[0249] The display device 400 shown in FIG14A includes transistors 252, 260, 258, light-emitting element 430b and light-receiving element 440 between substrates 451 and 452.

[0250] The light-emitting element 430b and the light-receiving element 440 may use the light-emitting element or the light-receiving element illustrated above.

[0251] Here, when a pixel of a display device includes three sub-pixels having light-emitting elements that emit different colors of light, examples of these three sub-pixels include sub-pixels of red (R), green (G), and blue (B), and sub-pixels of yellow (Y), cyan (C), and magenta (M). When four of the above-mentioned sub-pixels are included, examples of these four sub-pixels include sub-pixels of R, G, B, and white (W), and sub-pixels of R, G, B, and Y. Furthermore, a sub-pixel may also include a light-emitting element that emits infrared light.

[0252] Furthermore, the light-receiving element 440 may be a photoelectric conversion element that is sensitive to light in the red, green or blue wavelength region or a photoelectric conversion element that is sensitive to light in the infrared wavelength region.

[0253] Furthermore, the substrate 452 and the protective layer 416 are bonded together by an adhesive layer 442. The adhesive layer 442 overlaps with the light-emitting element 430b and the light-receiving element 440 respectively, and the display device 400 adopts a solid sealing structure. The substrate 452 is provided with a light-shielding layer 417.

[0254] The light-emitting element 430b and the light-receiving element 440, 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.

[0255] The conductive layer 411a in the light-emitting element 430b is electrically connected to the conductive layer 272b included in the transistor 260 through an opening provided in the insulating layer 294. The transistor 260 has the function of controlling the driving of the light-emitting element. On the other hand, the conductive layer 411a in the light-receiving element 440 is electrically connected to the conductive layer 272b in the transistor 258. The transistor 258 has the function of controlling the timing of exposure using the light-receiving element 440.

[0256] An EL layer 412G or a PD layer 412S is provided to cover the pixel electrode. An insulating layer 421 is provided in contact with the side surfaces of the EL layer 412G and the PD layer 412S, 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 to cover the EL layer 412G and the PD layer 412S. By forming the protective layer 416 covering the light-emitting element, impurities such as water can be prevented from entering the light-emitting element, thereby improving the reliability of the light-emitting element.

[0257] In addition, layers 415G and 415S are provided in contact with the insulating layer 421. Layer 415G contains the same material as EL layer 412G, and layer 415S contains the same material as PD layer 412S.

[0258] A portion of layer 415G includes: portions covering the ends of conductive layers 411a, 411b, and 411c of the light-receiving element 440; and portions overlapping with PD layer 412S and conductive layer 411c. A portion of layer 415S includes: portions covering the ends of conductive layers 411a, 411b, and 411c of the light-emitting element 430b; and portions overlapping with EL layer 412G and conductive layer 411c.

[0259] The light G emitted by the light-emitting element 430b is emitted to one side of the substrate 452. The light-receiving element 440 receives the light L through the substrate 452 and converts it into an electrical signal. The substrate 452 is preferably made of a material with high transmittance to visible light.

[0260] Transistors 252, 260 and 258 are all disposed on substrate 451. These transistors can be formed using the same material and the same process.

[0261] Note that transistors 252, 260, and 258 can also be manufactured with different structures. For example, transistors with or without a back gate can be manufactured separately, and transistors with different materials and thicknesses for the semiconductor, gate electrode, gate insulating layer, source electrode, and drain electrode can also be manufactured separately.

[0262] The substrate 451 and the insulating layer 262 are bonded together by the adhesive layer 455.

[0263] The manufacturing method of the display device 400 is as follows: First, a manufacturing substrate on which an insulating layer 262, each transistor, each light-emitting element, and a light-receiving element are disposed, is bonded together with a substrate 452 on which a light-shielding layer 417 is disposed, using an adhesive layer 442; then, the manufacturing substrate is peeled off and bonded to the exposed substrate 451 to transfer the components formed on the manufacturing substrate to the substrate 451. The substrates 451 and 452 are preferably flexible. This improves the flexibility of the display device 400.

[0264] A connection portion 254 is provided in a region of the substrate 451 that does not overlap with the substrate 452. In the connection portion 254, wiring 465 is electrically connected to the FPC 472 via a conductive layer 466 and a connection layer 292. The conductive layer 466 can be obtained by processing a conductive film identical to that of the pixel electrode. Therefore, the connection portion 254 can be electrically connected to the FPC 472 via the connection layer 292.

[0265] Transistors 252, 260, and 258 include: a conductive layer 271 serving as a gate; an insulating layer 261 serving as a gate insulating layer; a semiconductor layer 281 including a channel forming region 281i and a pair of low-resistance regions 281n; a conductive layer 272a connected to one of the pair of low-resistance regions 281n; a conductive layer 272b connected to the other of the pair of low-resistance regions 281n; an insulating layer 275 serving as a gate insulating layer; a conductive layer 273 serving as a gate; and an insulating layer 265 covering the conductive layer 273. The insulating layer 261 is located between the conductive layer 271 and the channel forming region 281i. The insulating layer 275 is located between the conductive layer 273 and the channel forming region 281i.

[0266] Conductive layers 272a and 272b are connected to the low-resistance region 281n through an opening provided in the insulating layer 265. One of the conductive layers 272a and 272b is used as a source, and the other is used as a drain.

[0267] Figure 14A shows an example of insulating layer 275 covering the top and side surfaces of semiconductor layer. Conductive layers 272a and 272b are connected to low-resistance region 281n through openings provided in insulating layers 275 and 265.

[0268] On the other hand, in the transistor 259 shown in FIG14B, the insulating layer 275 overlaps with the channel forming region 281i of the semiconductor layer 281 but does not overlap with the low-resistance region 281n. For example, the structure shown in FIG14B can be formed by processing the insulating layer 275 with the conductive layer 273 as a mask. In FIG14B, the insulating layer 265 covers the insulating layer 275 and the conductive layer 273, and the conductive layers 272a and 272b are respectively connected to the low-resistance region 281n through the opening of the insulating layer 265. Furthermore, an insulating layer 268 covering the transistor may also be provided.

[0269] 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.

[0270] Transistors 252, 260, and 258 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.

[0271] 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.

[0272] 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.

[0273] 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.

[0274] 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 In-M-Zn oxide.

[0275] 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.

[0276] For example, when the atomic ratio of the metallic elements is recorded as In:Ga:Zn = 4:2:3 or a similar composition, the content ratio of each element includes the following cases: 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 atomic ratio of the metallic elements is recorded as In:Ga:Zn = 5:1:6 or a similar composition, the content ratio of each element includes the following cases: 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 atomic ratio of the metallic elements is recorded as In:Ga:Zn = 1:1:1 or a similar composition, the content ratio of each element includes the following cases: 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.

[0277] 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 In:M:Zn = 1:3:2 or similar, In:M:Zn = 1:3:3 or similar, In:M:Zn = 1:3:4 or similar, etc. 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 of Id = 1 pA.

[0278] 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.).

[0279] In particular, low-temperature polysilicon has a high mobility and can be formed on a glass substrate, so it can be appropriately used in display devices. For example, as transistor 252 in a driving circuit, transistors with low-temperature polysilicon as the semiconductor layer can be used, and as transistors 260 and 258 in pixels, transistors with oxide semiconductor as the semiconductor layer can be used.

[0280] 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.

[0281] 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).

[0282] Note that the display device shown in Figure 14A includes an OS transistor and the common layer between the light-emitting elements is separated. By adopting this structure, the leakage current flowing through the transistor and the leakage current flowing between adjacent light-emitting elements (also known as lateral leakage current, side leakage current, etc.) can be extremely low. In addition, by adopting the above structure, when an image is displayed on the display device, the viewer can observe one or more of the following: image sharpness, image sharpness, high color saturation, and high contrast. Furthermore, by adopting a structure with extremely low leakage current flowing through the transistor and extremely low lateral leakage current between the light-emitting elements, minimal light leakage (so-called blackening) that can occur when displaying black can be achieved (also known as full black display).

[0283] In particular, when a separately coated structure (SBS structure) is used in a light-emitting device with an MML structure, the layers disposed between the light-emitting elements (e.g., organic layers used together between the light-emitting elements, also known as common layers) are separated, thereby enabling a display with no or very little side leakage.

[0284] 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.

[0285] 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.

[0286] Inorganic insulating films are preferably used as insulating layers 261, 262, 265, 268, and 275. 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.

[0287] 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 from the end of the display device 400. 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.

[0288] The insulating layer 294 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-polyimide resin, silicone resin, benzocyclobutene resin, phenolic resin, and precursors of the above resins.

[0289] Preferably, a light-shielding layer 417 is provided on the surface of the substrate 452 on the substrate 451 side. Furthermore, various optical components can be disposed on the outer side of the substrate 452. 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 452.

[0290] A connection portion 278 is shown in FIG14A. In the connection portion 278, a common electrode 413 is electrically connected to a wiring. FIG14A shows an example of a case where the wiring adopts the same stacked structure as the pixel electrode.

[0291] Substrates 451 and 452 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 451 and 452, the flexibility of the display device can be improved. A polarizing plate can be used as substrate 451 or substrate 452.

[0292] The following materials can be used as substrates 451 and 452: 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, glass with a flexible thickness can be used as one or both of substrates 451 and 452.

[0293] 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).

[0294] 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.

[0295] 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.

[0296] 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.

[0297] 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.

[0298] As the connecting layer 292, anisotropic conductive film (ACF) or anisotropic conductive paste (ACP) can be used.

[0299] 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.

[0300] Furthermore, as a conductive material with light transmittance, conductive oxides such as indium oxide, indium tin oxide, indium zinc oxide, zinc oxide, and gallium-containing zinc oxide, 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 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).

[0301] As 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.

[0302] 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.

[0303] At least a portion of this embodiment can be implemented in combination with other embodiments described in this specification.

[0304] Embodiment 3 In this embodiment, a display device according to one embodiment of the present invention will be described.

[0305] A display device according to one embodiment of the present invention includes a light-receiving element (also called a light-receiving device) and a light-emitting element (also called a light-emitting device). Alternatively, a display device according to one embodiment of the present invention may also include a light-emitting element (also called a light-receiving device) and a light-emitting element.

[0306] First, let me describe a display device that includes a light-receiving element and a light-emitting element.

[0307] A display device according to one embodiment of the present invention includes a light-receiving element and a light-emitting element in a light-receiving section. In the light-receiving section of the display device according to one embodiment of the present invention, the light-emitting elements are arranged in a matrix, and an image can be displayed on the light-receiving section. In addition, the light-receiving section, with its matrix arrangement of light-receiving elements, also has one or both of a camera function and a sensor function. The light-receiving section can be used as an image sensor or a touch sensor, etc. That is, by detecting light in the light-receiving section, image capture, detection of touch operations of objects (fingers, pens, etc.), etc., can be performed. Furthermore, the display device according to one embodiment of the present invention can use the light-emitting element as a light source for a sensor. Therefore, it is not necessary to provide a light-receiving section and a light source outside the display device, thus reducing the number of components in the electronic device.

[0308] In a display device according to one embodiment of the present invention, since the light receiving element can detect the reflected light (or scattered light) emitted by the light-emitting element included in the light-emitting part when the light is reflected (or scattered) by the object, the detection of camera operation, touch operation, etc. can be performed even in a dark environment.

[0309] In one embodiment of the present invention, the light-emitting element included in the display device is used as a display element (also called a display device).

[0310] As a light-emitting element, it is preferable to use EL elements (also known as EL devices) such as OLEDs and QLEDs. Examples of light-emitting materials included in EL elements include fluorescent materials, phosphorescent materials, and materials that exhibit thermally activated delayed fluorescence (TADF) materials. LEDs such as micro LEDs can also be used as light-emitting elements. In addition to organic compounds, inorganic compounds (quantum dot materials, etc.) can also be used as light-emitting materials included in EL elements.

[0311] A display device according to one embodiment of the present invention has the function of detecting emitted light using a light-receiving element.

[0312] When a light-receiving element is used as an image sensor, the display device can use the light-receiving element to capture images. For example, the display device can be used as a scanner.

[0313] An electronic device employing a display device according to one embodiment of the present invention can acquire data based on biometric data such as fingerprints and palm prints using the function of an image sensor. In other words, a biometric sensor can be provided within the display device. By providing a biometric sensor within the display device, compared to providing the display device and the biometric sensor separately, the number of components in the electronic device can be reduced, thereby enabling miniaturization and weight reduction of the electronic device.

[0314] Furthermore, when the light-receiving element is used as a touch sensor, the display device can use the light-receiving element to detect the touch operation of the object.

[0315] As a light-receiving element, for example, a pn-type or pin-type photodiode can be used. The light-receiving element is used as a photoelectric conversion element (also called a photoelectric conversion device) that detects light incident on the light-receiving element and generates a charge. The amount of charge generated by the light-receiving element depends on the amount of light incident on the light-receiving element.

[0316] In particular, as a light-receiving element, an organic photodiode having a layer containing an organic compound is preferred. Organic photodiodes are easy to make thin, lightweight and large-area, and their shape and design are highly flexible, so they can be applied to a wide variety of devices.

[0317] In one embodiment of the present invention, an organic EL element (also called an organic EL device) is used as a light-emitting element, and an organic photodiode is used as a light-receiving element. The organic EL element 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 element.

[0318] When all the layers constituting the organic EL element and the organic photodiode are manufactured separately, the number of film deposition processes is very large. However, since the organic photodiode includes multiple layers that can have the same structure as the organic EL element, the increase in film deposition processes can be suppressed by forming layers that can have the same structure as the organic EL element in one step.

[0319] For example, one of the pairs of electrodes (the common electrode) can be a layer shared between the light-receiving element and the light-emitting element. Furthermore, for example, at least one of a hole injection layer, a hole transport layer, an electron transport layer, and an electron injection layer can also be a layer shared between the light-receiving element and the light-emitting element. Thus, because a layer is shared between the light-receiving element and the light-emitting element, the number of film deposition steps and the number of masks can be reduced, thereby reducing the process and manufacturing cost of the display device. Furthermore, display devices including light-receiving elements can be manufactured using existing manufacturing equipment and methods for display devices.

[0320] Next, a display device including a light-emitting element and a light-emitting element will be described. Note that sometimes the description of the same functions, effects, etc. as described above is omitted.

[0321] In a display device according to one embodiment of the present invention, a sub-pixel displaying any color includes a light-receiving element instead of a light-emitting element, and a sub-pixel displaying other colors includes a light-emitting element. The light-receiving element has two functions: emitting light (light-emitting function) and receiving light (light-receiving function). For example, in the case where a pixel includes three sub-pixels: a red sub-pixel, a green sub-pixel, and a blue sub-pixel, at least one of the sub-pixels includes a light-receiving element and the other sub-pixels include light-emitting elements. Therefore, the light-receiving section of the display device according to one embodiment of the present invention has the function of displaying an image using both the light-receiving element and the light-emitting element.

[0322] A light-emitting element is used as both a light-emitting element and a light-receiving element, thereby enabling the addition of a light-receiving function to a pixel without increasing the number of sub-pixels contained in the pixel. Therefore, one or both of a camera function and a sensing function can be added to the light-receiving part of the display device while maintaining the pixel aperture ratio (aperture ratio of each sub-pixel) and the resolution of the display device. Thus, compared to the case where sub-pixels including light-emitting elements are provided in addition to sub-pixels including light-emitting elements, the display device according to one embodiment of the present invention can improve the pixel aperture ratio and is easier to achieve high resolution.

[0323] In the light-receiving section of a display device according to one embodiment of the present invention, light-receiving elements and light-emitting elements are arranged in a matrix, thereby enabling the display of images on the light-receiving section. The light-receiving section can be used as an image sensor or a touch sensor, etc. In the display device according to one embodiment of the present invention, the light-emitting elements can be used as the light source of the sensor. Therefore, imaging, touch operation detection, etc., can be performed even in dark environments.

[0324] The light-emitting element can be manufactured by combining an organic EL element and an organic photodiode. For example, a light-emitting element can be manufactured by adding an active layer of an organic photodiode to a stacked structure of an organic EL element. Furthermore, in a light-emitting element manufactured by combining an organic EL element and an organic photodiode, by forming a layer together that has a structure that can be used in conjunction with the organic EL element, the increase in film deposition process can be suppressed.

[0325] For example, one of the pairs of electrodes (the common electrode) may be a layer shared between the light-receiving element and the light-emitting element. In addition, for example, at least one of the hole injection layer, hole transport layer, electron transport layer and electron injection layer may also be a layer shared between the light-receiving element and the light-emitting element.

[0326] Furthermore, the layers included in the light-emitting element sometimes have different functions when used as a light-receiving element and when used as a light-emitting element. In this specification, the components are referred to according to their function when the light-emitting element is used as a light-emitting element.

[0327] The display device of this embodiment has the function of displaying images using a light-emitting element and a light-receiving element. That is, the light-emitting element and the light-receiving element are used as display elements.

[0328] The display device of this embodiment has the function of detecting light using a light-emitting element. The light-emitting element is capable of detecting light whose wavelength is shorter than the light emitted by the light-emitting element itself.

[0329] When the light-emitting element is used as an image sensor, the display device of this embodiment can capture images using the light-emitting element. Furthermore, when the light-emitting element is used as a touch sensor, the display device of this embodiment can detect touch operations on objects using the light-emitting element.

[0330] The light-receiving element is used as a photoelectric conversion element. The light-receiving element can be manufactured by adding an active layer of light-receiving element to the structure of the above-mentioned light-receiving element. For example, the active layer of a pn-type or pin-type photodiode can be used for the light-receiving element.

[0331] In particular, the light-emitting element is preferably an active layer of an organic photodiode having a layer containing an organic compound. Organic photodiodes are easy to make thin, lightweight and large-area, and their shape and design are highly flexible, so they can be applied to a wide variety of devices.

[0332] The following describes a display device as an example of an embodiment of the present invention with reference to the drawings.

[0333] [Example 1 of the structure of the display device] [Example 1-1] FIG15A shows a schematic diagram of a display panel 200. The display panel 200 includes a substrate 201, a substrate 202, a light-receiving element 212, a light-emitting element 211R, a light-emitting element 211G, a light-emitting element 211B, a functional layer 203, etc.

[0334] Light-emitting elements 211R, 211G, 211B, and light-receiving element 212 are disposed between substrate 201 and substrate 202. Light-emitting elements 211R, 211G, and 211B emit red (R), green (G), or blue (B) light, respectively. Note that, in the following text, light-emitting elements 211R, 211G, and 211B are sometimes referred to as light-emitting element 211 without distinguishing between them.

[0335] The display panel 200 has multiple pixels configured in a matrix. Each pixel includes one or more sub-pixels. Each sub-pixel has a light-emitting element. For example, a pixel may have a structure including three sub-pixels (three colors: R, G, and B, or three colors: yellow (Y), cyan (C), and magenta (M), etc.) or a structure including four sub-pixels (four colors: R, G, B, and white (W), or four colors: R, G, B, and Y, etc.). Furthermore, each pixel has a light-receiving element 212. The light-receiving element 212 may be provided in all pixels or in a portion of the pixels. In addition, a pixel may have multiple light-receiving elements 212.

[0336] Figure 15A shows the surface of the finger 220 touching the substrate 202. A portion of the light emitted by the light-emitting element 211G is reflected by the contact portion between the substrate 202 and the finger 220. Then, a portion of the reflected light is incident on the light-receiving element 212, thereby detecting that the finger 220 is touching the substrate 202. In other words, the display panel 200 can be used as a touch panel.

[0337] Functional layer 203 includes circuits for driving light-emitting elements 211R, 211G, and 211B, as well as circuits for driving light-receiving element 212. Switches, transistors, capacitors, wiring, etc., are provided in functional layer 203. Alternatively, when light-emitting elements 211R, 211G, 211B, and 212 are driven in a passive matrix manner, switches, transistors, etc., may not be provided.

[0338] Preferably, the display panel 200 has the function of detecting fingerprints of the finger 220. FIG15B is an enlarged view schematically showing the contact portion when the finger 220 is in contact with the substrate 202. In addition, FIG15B shows alternating light-emitting elements 211 and light-receiving elements 212.

[0339] The fingerprint of finger 220 is formed by concave and convex portions. Therefore, the convex portion of the fingerprint touches the substrate 202 as shown in FIG15B.

[0340] Light reflected from a surface or interface can be either regular or diffuse. Regularly reflected light is highly directional light where the angle of incidence and the angle of reflection are the same, while diffusely reflected light is less directional light with low intensity dependence on angle. In the light reflected from the surface of finger 220, diffuse reflection is the dominant component compared to regular reflection. On the other hand, in the light reflected from the interface between substrate 202 and the atmosphere, regular reflection is the dominant component.

[0341] The light intensity reflected from or incident on the contact or non-contact surfaces of the finger 220 and the substrate 202 onto the light-receiving element 212 located directly below them is the combined intensity of regularly reflected light and diffused light. As described above, in the recess of the finger 220, the finger 220 does not touch the substrate 202, thus regularly reflected light (indicated by solid arrows) is dominant; in its convex portion, the finger 220 touches the substrate 202, thus diffused light reflected from the finger 220 is dominant (indicated by dashed arrows). Therefore, the light intensity received by the light-receiving element 212 located directly below the recess is higher than that received by the light-receiving element 212 located directly below the convex portion. Thus, fingerprints of the finger 220 can be captured.

[0342] When the arrangement interval of the light-receiving elements 212 is smaller than the distance between two convex parts of a fingerprint, and preferably smaller than the distance between adjacent concave and convex parts, a clear fingerprint image can be obtained. Since the distance between the concave and convex parts of a human fingerprint is approximately 200 μm, the arrangement interval of the light-receiving elements 212 is, for example, 400 μm or less, preferably 200 μm or less, more preferably 150 μm or less, further preferably 100 μm or less, further preferably 50 μm or less, and is 1 μm or more, preferably 10 μm or more, and more preferably 20 μm or more.

[0343] Figure 15C shows an example of a fingerprint image captured by the display panel 200. In Figure 15C, the outline of the finger 220 is shown in dashed lines within the shooting area 223, and the outline of the contact portion 221 is shown in dotted lines. Within the contact portion 221, a high-contrast fingerprint 222 can be captured by utilizing the different amounts of light incident on the light-receiving element 212.

[0344] The display panel 200 can also be used as a touch panel or a graphics tablet. Figure 15D shows the stylus 225 being slid in the direction of the dashed arrow with the tip of the stylus 225 in contact with the substrate 202.

[0345] As shown in FIG15D, by the diffuse reflection light diffused on the surface of the stylus 225 in contact with the substrate 202, the light receiving element 212 located in the part overlapping with the contact surface can be detected with high precision.

[0346] Figure 15E shows an example of the trajectory 226 of the stylus 225 detected by the display panel 200. The display panel 200 can detect the position of the detected object, such as the stylus 225, with high positional accuracy, so high-precision drawing can be performed in drawing applications, etc. In addition, unlike the case of using electrostatic capacitive touch sensors or electromagnetic induction styluses, the position can be detected even for highly insulating objects, so various writing tools (such as pens, glass pens, quill pens, etc.) can be used, regardless of the material of the tip of the stylus 225.

[0347] Here, Figures 15F to 15H show an example of pixels that can be used in the display panel 200.

[0348] The pixels shown in Figures 15F and 15G each include a red (R) light-emitting element 211R, a green (G) light-emitting element 211G, a blue (B) light-emitting element 211B, and a light-receiving element 212. Each pixel includes a pixel circuit for driving the light-emitting element 211R, the light-emitting element 211G, the light-emitting element 211B, and the light-receiving element 212.

[0349] Figure 15F shows an example of three light-emitting elements and one light-receiving element arranged in a 2×2 matrix. Figure 15G shows an example of three light-emitting elements arranged in a row with a horizontally elongated light-receiving element 212 arranged below them.

[0350] The pixel shown in Figure 15H is an example including a white (W) light-emitting element 211W. Here, four sub-pixels are arranged in a column, and a light-receiving element 212 is arranged on the lower side of it.

[0351] Note that the structure of pixels is not limited to the above examples, and various configuration methods can be used.

[0352] [Structural Examples 1-2] The following describes structural examples including a light-emitting element that emits visible light, a light-emitting element that emits infrared light, and a light-receiving element.

[0353] The display panel 200A shown in FIG. 16A includes a light-emitting element 211IR as an addition to the structure shown in FIG. 15A. The light-emitting element 211IR emits infrared light IR. At this time, as the light-receiving element 212, it is preferable to use an element that is at least capable of receiving the infrared light IR emitted by the light-emitting element 211IR. In addition, as the light-receiving element 212, it is more preferable to use an element that is capable of receiving both visible light and infrared light.

[0354] As shown in FIG16A, when the finger 220 touches the substrate 202, the infrared light IR emitted from the light-emitting element 211IR is reflected by the finger 220, and a portion of the reflected light is incident on the light-receiving element 212, thereby obtaining the position data of the finger 220.

[0355] Figures 16B to 16D show an example of a pixel that can be used in the display panel 200A.

[0356] Figure 16B shows an example in which three light-emitting elements are arranged in a row and light-emitting elements 211IR and light-receiving elements 212 are arranged horizontally below them. In addition, Figure 16C shows an example in which four light-emitting elements, including light-emitting elements 211IR, are arranged in a row and light-receiving elements 212 are arranged below them.

[0357] Figure 16D shows an example in which three light-emitting elements and light-receiving elements 212 are arranged in four directions with the light-emitting element 211IR as the center.

[0358] In the pixels shown in Figures 16B to 16D, the positions of each light-emitting element can be interchanged, and the positions of the light-emitting element and the light-receiving element can also be interchanged.

[0359] [Structural Examples 1-3] Hereinafter, examples of structures including a light-emitting element that emits visible light and a light-receiving element that emits and receives visible light will be described.

[0360] The display panel 200B shown in FIG17A includes a light-emitting element 211B, a light-emitting element 211G, and a light-emitting element 213R. The light-emitting element 213R functions as a light-emitting element that emits red (R) light and as a photoelectric conversion element that receives visible light. FIG17A shows an example of the light-emitting element 213R receiving green (G) light emitted by the light-emitting element 211G. Note that the light-emitting element 213R can also receive blue (B) light emitted by the light-emitting element 211B. In addition, the light-emitting element 213R can also receive both green and blue light.

[0361] For example, the light-emitting element 213R preferably receives light whose wavelength is shorter than the light emitted by the light-emitting element 213R itself. Alternatively, the light-emitting element 213R may also receive light whose wavelength is longer than the light emitted by itself (e.g., infrared light). The light-emitting element 213R may receive wavelengths of the same magnitude as the light it emits, but in this case, it also receives the light it emits, and sometimes the luminous efficiency decreases. Therefore, the light-emitting element 213R is preferably configured such that the peaks of the emission spectrum do not overlap with the peaks of the absorption spectrum as much as possible.

[0362] Furthermore, the light emitted by the light-emitting element is not limited to red light. In addition, the light emitted by the light-emitting element is not limited to a combination of green and blue light. For example, an element that emits green or blue light and receives light of a different wavelength than the light it emits can be used as the light-emitting element.

[0363] Thus, by using the light-receiving element 213R as both a light-emitting element and a light-receiving element, the number of elements arranged in a pixel can be reduced. Therefore, it is easy to achieve high definition, high aperture ratio, and high resolution.

[0364] Figures 17B to 17I show an example of pixels that can be used in display panel 200B.

[0365] Figure 17B shows an example of the light-receiving element 213R, the light-emitting element 211G, and the light-emitting element 211B arranged in a row. Figure 17C shows an example of the light-emitting elements 211G and 211B arranged alternately in the longitudinal direction, with the light-receiving element 213R arranged next to them.

[0366] Figure 17D shows an example of three light-emitting elements (light-emitting element 211G, light-emitting element 211B, and light-emitting element 211X) and one light-receiving element arranged in a 2×2 matrix. Light-emitting element 211X is an element that emits light other than R, G, and B. Examples of light other than R, G, and B include white (W), yellow (Y), cyan (C), magenta (M), infrared (IR), and ultraviolet (UV). When light-emitting element 211X emits infrared light, the light-receiving element preferably has the function of detecting infrared light or both visible and infrared light. The wavelength of the light detected by the light-receiving element can be determined according to the application of the sensor.

[0367] Figure 17E shows what corresponds to two pixels. The area including the three elements surrounded by dashed lines corresponds to one pixel. Each pixel includes a light-emitting element 211G, a light-emitting element 211B, and a light-receiving element 213R. In the left pixel of Figure 17E, the light-emitting element 211G is arranged in the same row as the light-receiving element 213R, and the light-emitting element 211B is arranged in the same column as the light-receiving element 213R. In the right pixel of Figure 17E, the light-emitting element 211G is arranged in the same row as the light-receiving element 213R, and the light-emitting element 211B is arranged in the same column as the light-emitting element 211G. In the pixel layout shown in Figure 17E, the light-receiving element 213R, the light-emitting element 211G, and the light-emitting element 211B are repeatedly arranged in the odd-numbered and even-numbered rows, and in each column, the odd-numbered and even-numbered rows respectively have light-emitting elements or light-receiving elements that emit different colors from each other.

[0368] Figure 17F shows four pixels arranged in a Pentile pattern, where two adjacent pixels include light-emitting elements or light-receiving elements that emit light of two different colors. Figure 17F shows the top surface shape of the light-emitting or light-receiving elements.

[0369] The upper left and lower right pixels in Figure 17F include a light-receiving element 213R and a light-emitting element 211G. Additionally, the upper right and lower left pixels include a light-emitting element 211G and a light-emitting element 211B. That is, in the example shown in Figure 17F, each pixel is provided with a light-emitting element 211G.

[0370] There are no particular restrictions on the top surface shape of the light-emitting element and the light-receiving element; they can be circular, elliptical, polygonal, or polygonal with curved corners, etc. In Figure 17F, an example of a square (rhombus) tilted at approximately 45 degrees is shown as the top surface shape of the light-emitting element and the light-receiving element. Note that the top surface shapes of the light-emitting elements and light-receiving elements of different colors can be different from each other, or they can be the same in some or all of the colors.

[0371] The size of the light-emitting area (or light-receiving area) of each color light-emitting element and light-receiving element can be different from each other, or they can be the same in some or all colors. For example, in FIG17F, the area of ​​the light-emitting area of ​​the light-emitting element 211G provided in each pixel can be smaller than the light-emitting area (or light-receiving area) of other elements.

[0372] Figure 17G shows a modified example of the pixel arrangement shown in Figure 17F. Specifically, the structure of Figure 17G can be obtained by rotating the structure of Figure 17F by 45 degrees. In Figure 17F, it is shown that a pixel consists of two elements, but as shown in Figure 17G, it can also be said that a pixel consists of four elements.

[0373] Figure 17H ​​is a modified example of the pixel arrangement shown in Figure 17F. The upper left and lower right pixels in Figure 17H ​​include a light-receiving element 213R and a light-emitting element 211G. Additionally, the upper right and lower left pixels include a light-receiving element 213R and a light-emitting element 211B. That is, in the example shown in Figure 17H, each pixel is equipped with a light-receiving element 213R. Because each pixel is equipped with a light-receiving element 213R, the structure shown in Figure 17H ​​can be captured with high resolution compared to the structure shown in Figure 17F. Therefore, for example, the accuracy of biometric identification can be improved.

[0374] Figure 17I is a modified example of the pixel arrangement shown in Figure 17H, which can be obtained by rotating the pixel arrangement by 45 degrees.

[0375] In Figure 17I, it is assumed that a pixel consists of four elements (two light-emitting elements and two light-receiving elements). Thus, when a pixel includes multiple light-receiving elements with light-receiving functions, high-resolution imaging can be achieved. Therefore, the accuracy of biometrics can be improved. For example, the image resolution can be up to the display resolution multiplied by the root of 2.

[0376] A display device having the structure shown in FIG17H or FIG17I includes p first light-emitting elements (p being an integer greater than 2), q second light-emitting elements (q being an integer greater than 2), and r light-receiving elements (r being an integer greater than p and greater than q). p and r satisfy r = 2p. Furthermore, p, q, and r satisfy r = p + q. One of the first and second light-emitting elements emits green light, and the other emits blue light. The light-receiving elements emit red light and have a light-receiving function.

[0377] For example, when using a light-emitting element to detect contact operations, the light emitted from the light source is preferably not easily seen by the user. Since the visibility of blue light is lower than that of green light, it is preferable to use a light-emitting element that emits blue light as the light source. Therefore, the light-emitting element preferably has the function of emitting blue light. Note that this is not a limitation; the light-emitting element used as the light source can be appropriately selected based on the sensitivity of the light-emitting element.

[0378] Thus, pixels of various arrangements can be used in the display device of this embodiment.

[0379] At least a portion of this embodiment may be implemented in combination with other embodiments described in this specification.

[0380] Embodiment 4 In this embodiment, a light-emitting element (also called a light-emitting device) and a light-receiving element (also called a light-receiving device) of a light-emitting device that can be used in one embodiment of the present invention will be described.

[0381] In this specification, etc., devices manufactured using a metal mask or FMM (Fine Metal Mask, High Definition 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.

[0382] 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 white light-emitting device, combined with a color layer (e.g., a color filter), can realize a full-color display device.

[0383] Furthermore, light-emitting devices can be broadly classified into single-structure and series-structure devices. A single-structure device preferably 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, it is possible to select two or more light-emitting layers to form a colorless light-emitting layer. For example, in the case of two colors, 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.

[0384] A 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 increased brightness per specified current and higher reliability than a single-structure device can be achieved. To obtain white light emission in a 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 a series-connected device, it is preferable to provide an intermediate layer such as a charge-generating layer between multiple light-emitting units.

[0385] 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. When power consumption is desired, it is preferable to use an SBS structure light-emitting device. 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 improving manufacturing yield, which is therefore preferable.

[0386] [Device Structure] Next, the detailed structure of the light-emitting element, light-receiving element and light-receiving element of a display device that can be used in one embodiment of the present invention will be described.

[0387] The display device according to one embodiment of the present invention may adopt any of the following structures: a top emission structure that emits light in the direction opposite to that of the substrate on which the light-emitting element is formed; a bottom emission structure that emits light in the direction of the substrate on which the light-emitting element is formed; and a double-sided emission structure that emits light in both directions.

[0388] In this embodiment, a display device with a top-emitting structure will be used as an example for explanation.

[0389] Note that in this specification, unless otherwise stated, even when describing a structure that includes multiple elements (light-emitting elements, light-emitting layers, etc.), the letters of the symbols for common parts among the elements are omitted. For example, when describing common elements in light-emitting layers 383R and 383G, they are sometimes referred to as light-emitting layer 383.

[0390] The display device 380A shown in FIG18A includes a light receiving element 370PD, a light emitting element 370R that emits red (R) light, a light emitting element 370G that emits green (G) light and a light emitting element 370B that emits blue (B) light.

[0391] Each light-emitting element is sequentially stacked with a pixel electrode 371, a hole injection layer 381, a hole transport layer 382, ​​a light-emitting layer, an electron transport layer 384, an electron injection layer 385, and a common electrode 375. Light-emitting element 370R includes a light-emitting layer 383R, light-emitting element 370G includes a light-emitting layer 383G, and light-emitting element 370B includes a light-emitting layer 383B. Light-emitting layer 383R contains a light-emitting material that emits red light, light-emitting layer 383G contains a light-emitting material that emits green light, and light-emitting layer 383B contains a light-emitting material that emits blue light.

[0392] The light-emitting element is an electric field light-emitting element that emits light toward the common electrode 375 by applying a voltage between the pixel electrode 371 and the common electrode 375.

[0393] The light-receiving element 370PD is sequentially stacked with a pixel electrode 371, a hole injection layer 381, a hole transport layer 382, ​​an active layer 373, an electron transport layer 384, an electron injection layer 385, and a common electrode 375.

[0394] The light receiving element 370PD is a photoelectric conversion element that receives light incident from the outside of the display device 380A and converts it into an electrical signal.

[0395] In this embodiment, the case in which the pixel electrode 371 is used as the anode and the common electrode 375 is used as the cathode in both the light-emitting element and the light-receiving element will be described. That is, by applying a reverse bias voltage between the pixel electrode 371 and the common electrode 375 to drive the light-receiving element, the light incident on the light-receiving element can be detected, a charge can be generated, and the charge can be extracted in the form of a current.

[0396] In the display device of this embodiment, the active layer 373 of the light-receiving element 370PD uses an organic compound. The layers other than the active layer 373 of the light-receiving element 370PD can have the same structure as the light-emitting element. Therefore, by simply adding a process for forming the active layer 373 to the process of forming the light-emitting element, the light-receiving element 370PD can be formed simultaneously with the formation of the light-emitting element. Furthermore, the light-emitting element and the light-receiving element 370PD can be formed on the same substrate. Therefore, the light-receiving element 370PD can be provided within the display device without significantly increasing the number of processes.

[0397] In the display device 380A, an example is shown where an active layer 373 for forming a light-receiving element 370PD and a light-emitting layer 383 for forming a light-emitting element are respectively formed, and other layers are shared by the light-receiving element 370PD and the light-emitting element. However, the structure of the light-receiving element 370PD and the light-emitting element is not limited to this. In addition to the active layer 373 and the light-emitting layer 383, the light-receiving element 370PD and the light-emitting element may also include other separately formed layers. It is preferable that the light-receiving element 370PD and the light-emitting element share one or more layers (common layers). Thus, the light-receiving element 370PD can be provided in the display device without significantly increasing the manufacturing process.

[0398] As the electrode on the light-extracting side of the pixel electrode 371 and the common electrode 375, a conductive film that allows visible light to pass through is used. Furthermore, as the electrode on the non-light-extracting side, a conductive film that reflects visible light is preferably used.

[0399] The light-emitting element included in the display device of this embodiment preferably employs an optical microcavity resonator (microcavity) structure. Therefore, one of the pair of electrodes included in the light-emitting element is preferably an electrode that is both transmissive and reflective to visible light (semi-transmissive-semi-reflective electrode), and the other is preferably an electrode that is reflective to visible light (reflective electrode). When the light-emitting element has a microcavity structure, the light emission obtained from the light-emitting layer can be resonated between the two electrodes, and the light emitted from the light-emitting element can be enhanced.

[0400] Note that a semi-transparent-semi-reflective electrode can be a stacked structure of a reflective electrode and an electrode that is transparent to visible light (also known as a transparent electrode).

[0401] The light transmittance of the transparent electrode is 40% or more. For example, in a light-emitting element, it is preferable to use an electrode with a transmittance of 40% or more for visible light (light with a wavelength of 400 nm or more and less than 750 nm). The reflectance of the semi-transparent-semi-reflective electrode for visible light is 10% or more and less than 95%, preferably 30% or more and less than 80%. The reflectance of the reflective electrode for visible light is 40% or more and less than 100%, preferably 70% or more and less than 100%. In addition, the resistivity of these electrodes is preferably 1 × 10⁻² Ωcm or less. Furthermore, when the light-emitting element emits near-infrared light (light with a wavelength of 750 nm or more and less than 1300 nm), similar to the transmittance or reflectance for visible light, the transmittance or reflectance of these electrodes for near-infrared light preferably meets the above-mentioned numerical range.

[0402] The light-emitting element includes at least a light-emitting layer 383. In addition to the light-emitting layer 383, the light-emitting element 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, a material with high electron injection capacity, an electron blocking material, or a bipolar material (a material with high electron transport capacity and high hole transport capacity).

[0403] For example, the light-emitting element and the light-receiving element may share one or more of the following: a hole injection layer, a hole transport layer, an electron transport layer, and an electron injection layer. Alternatively, the light-emitting element and the light-receiving element may each be formed with one or more of the following: a hole injection layer, a hole transport layer, an electron transport layer, and an electron injection layer.

[0404] The hole injection layer is a layer containing a material with high hole injection capability, into which holes are injected from the anode to the hole transport layer. As a material with high hole injection capability, aromatic amine compounds, composite materials containing hole transport materials and acceptor materials (electron acceptor materials) can be used.

[0405] In a light-emitting element, the hole transport layer is a layer that transports holes injected from the anode to the light-emitting layer via a hole injection layer. In a light-receiving element, the hole transport layer is a layer that transports holes generated by light incident on the active layer to the anode. 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. Note that any material other than the above can be used as long as the hole transportability is higher than the electron transportability. As a hole transporting material, it is preferable to use a π-electron-rich heteroaromatic compound (e.g., carbazole derivatives, thiophene derivatives, furan derivatives, etc.) or an aromatic amine (a compound containing an aromatic amine skeleton) or other materials with high hole transportability.

[0406] In a light-emitting element, the electron transport layer is a layer that transports electrons injected from the cathode to the light-emitting layer via an electron injection layer. In a light-receiving element, the electron transport layer is a layer that transports electrons generated based on light incident on the active layer to the cathode. 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. Note that any material other than the one described above can be used as long as the electron transport capability is higher than the hole transport capability. As electron transport materials, materials with high electron transport properties can be used, such as metal complexes containing a quinoline skeleton, metal complexes containing a benzoquinoline skeleton, metal complexes containing a chloroazole skeleton, metal complexes containing a thiazole skeleton, chlorodiazole derivatives, triazole derivatives, imidazole derivatives, chloroazole derivatives, thiazole derivatives, pheno-line derivatives, quinoline derivatives containing quinoline ligands, benzoquinoline derivatives, quinoline derivatives, dibenzoquinoline derivatives, pyridine derivatives, bipyridine derivatives, pyrimidine derivatives, and nitrogen-containing heteroaromatic compounds, etc.

[0407] 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.

[0408] The luminescent layer 383 is a layer comprising a luminescent material. The luminescent layer 383 may include one or more luminescent materials. As the luminescent material, materials exhibiting luminescent colors such as blue, purple, blue-violet, green, yellow-green, yellow, orange, and red are appropriately used. In addition, materials emitting near-infrared light may also be used as the luminescent material.

[0409] As luminescent materials, examples include fluorescent materials, phosphorescent materials, TADF materials, quantum dot materials, etc.

[0410] 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.

[0411] 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.

[0412] In addition to the luminescent material (guest material), the luminescent layer 383 may also contain one or more organic compounds (host material, auxiliary material, etc.). As one or more organic compounds, one or both of the hole transport material and electron transport material described in this embodiment may be used. In addition, as one or more organic compounds, bipolar materials or TADF materials may also be used.

[0413] For example, the luminescent layer 383 is preferably a combination comprising a phosphorescent material, a hole-transporting material that readily forms excited-state complexes, and an electron-transporting material. By employing such a structure, ExTET (Exciplex-Triplet Energy Transfer) luminescence, utilizing energy transfer from the excited-state complex to the luminescent material (phosphorescent material), can be efficiently obtained. Furthermore, by using a combination of light whose wavelength overlaps with the absorption band of the lowest energy side of the luminescent material, which is selectively formed by the excited-state complex, energy transfer can be facilitated, thereby achieving efficient luminescence. By employing the above structure, high efficiency, low-voltage operation, and long lifetime of the luminescent element can be simultaneously achieved.

[0414] As a combination of materials forming excited-state complexes, the HOMO level (highest occupied molecular orbital level) of the hole-transporting material is preferably a value higher than or equal to the HOMO level of the electron-transporting material. The LUMO level (lowest vacant molecular orbital level) of the hole-transporting material is preferably a value higher than or equal to the LUMO level of the electron-transporting material. Note that the LUMO and HOMO levels of the material can be determined from the electrochemical properties (reduction potential and oxidation potential) of the material measured by cyclic voltammetry (CV).

[0415] Note that the formation of excited-state complexes can be confirmed, for example, by comparing the emission spectra of materials with hole transport properties, materials with electron transport properties, and the emission spectra of a mixed film formed by mixing these materials. When the emission spectrum of the mixed film is observed to shift towards a longer wavelength side (or to have a new peak on the longer wavelength side) compared to the emission spectra of each material, it indicates the formation of excited-state complexes. Alternatively, by comparing the transient photoluminescence (PL) of materials with hole transport properties, the transient PL of materials with electron transport properties, and the transient PL of a mixed film formed by mixing these materials, when a difference in transient response is observed, such as the transient PL lifetime of the mixed film having a longer lifetime component or a larger ratio of delayed components compared to the transient PL lifetimes of each material, it indicates the formation of excited-state complexes. Furthermore, the aforementioned transient PL can be referred to as transient electroluminescence (EL). In other words, by comparing the transient EL of materials with hole transport properties, the transient EL of materials with electron transport properties, and the transient EL of a mixed film of these materials, and observing the differences in transient responses, the formation of excited-state complexes can also be confirmed.

[0416] The active layer 373 comprises a semiconductor. Examples of such semiconductors include inorganic semiconductors such as silicon and organic semiconductors containing organic compounds. In this embodiment, an example is shown where an organic semiconductor is used as the semiconductor comprised in the active layer 373. Because an organic semiconductor is used, the light-emitting layer 383 and the active layer 373 can be formed using the same method (e.g., vacuum evaporation) and can share the same manufacturing equipment, which is preferable.

[0417] As materials for the n-type semiconductor contained in the active layer 373, examples include fullerenes (e.g., C60, C70, etc.) and fullerene derivatives, which are organic semiconductor materials with electron-accepting properties. Fullerenes have a soccer ball shape, which is energy stable. Fullerenes have deep (low) HOMO and LUMO energy levels. Because fullerenes have a deep LUMO energy level, their electron acceptor properties are extremely high. Generally, when π-electron conjugation (resonance) expands in a plane, such as in benzene, electron donor properties become high. On the other hand, fullerenes have a spherical shape, and although π-electron conjugation expands, their electron acceptor properties become high. With high electron acceptor properties, charge separation is induced quickly and efficiently, which is beneficial for light-receiving elements. C60 and C70 both have broad absorption bands in the visible light region. In particular, C70 has a larger π-electron conjugation system than C60 and also has a broader 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 PC70BM), methyl [6,6]-phenyl-C61-butyrate (abbreviated as PC60BM), 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).

[0418] Examples of materials used as n-type semiconductors include perylene tetracarboxylic acid derivatives such as N,N'-dimethyl-3,4,9,10-perylene tetracarboxylic acid diimidimide (abbreviated as Me-PTCDI).

[0419] As a material for n-type semiconductors, for example, 2,2'-(5,5'-(thiophene[3,2-b]thiophene-2,5-diyl)bis(thiophene-5,2-diyl))bis(methane-1-yl-1-ylidene)dipropionitrile (abbreviated as: FT2TDMN).

[0420] As materials for n-type semiconductors, examples include metal complexes with a quinoline skeleton, metal complexes with a benzoquinoline skeleton, metal complexes with a chloroazole skeleton, metal complexes with a thiazole skeleton, chlorodiazole derivatives, triazole derivatives, imidazole derivatives, chloroazole 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.

[0421] As materials for the p-type semiconductor contained in the active layer 373, examples of organic semiconductor materials with electronic donor properties include copper(II) phthalocyanine (CuPc), tetraphenyldibenzoperiflanthene (DBP), zinc phthalocyanine (ZnPc), tin phthalocyanine (SnPc), quinacridone, and red fluorene.

[0422] 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, 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, red fluorene derivatives, condensed tetraphenylene derivatives, polyphenylene oxide derivatives, poly[a] ...

[0423] 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.

[0424] Preferably, spherical fullerenes are used as organic semiconductor materials with electron-accepting properties, and even 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.

[0425] For example, it is preferable to co-deposit an n-type semiconductor and a p-type semiconductor to form the active layer 373. Alternatively, an n-type semiconductor and a p-type semiconductor may be stacked to form the active layer 373.

[0426] The light-emitting element and the light-receiving element may use low-molecular-weight compounds or high-molecular-weight compounds, and may also include inorganic compounds. The layers constituting the light-emitting element and the light-receiving element may be formed by methods such as vapor deposition (including vacuum vapor deposition), transfer printing, printing, inkjet printing, coating, etc.

[0427] For example, as hole transport materials or electron blocking materials, 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. Alternatively, as electron transport materials or hole blocking materials, inorganic compounds such as zinc oxide (ZnO) and organic compounds such as ethoxylated polyethyleneimine (PEIE) can be used. The light-receiving device may, for example, include a mixed film of PEIE and ZnO.

[0428] As the active layer 373, a polymeric compound such as poly[[4,8-bis[5-(2-ethylhexyl)-2-thiophene]benzo[1,2-b:4,5-b']dithiophene-2,6-diyl]-2,5-thiophenediyl[5,7-bis(2-ethylhexyl)-4,8-dioxo-4H,8H-benzo[1,2-c:4,5-c']dithiophene-1,3-diyl]] (abbreviated as PBDB-T) or a PBDB-T derivative can be used. For example, a method of dispersing the acceptor material into PBDB-T or a PBDB-T derivative can be used.

[0429] The difference between the display device 380B shown in Figure 18B and the display device 380A is that the light-receiving element 370PD and the light-emitting element 370R have the same structure.

[0430] The light-receiving element 370PD and the light-emitting element 370R share the active layer 373 and the light-emitting layer 383R.

[0431] Here, the light-receiving element 370PD preferably adopts the same structure as the light-emitting element that emits light with a wavelength longer than the light to be detected. For example, the light-receiving element 370PD for detecting blue light may adopt the same structure as one or both of the light-emitting elements 370R and 370G. For example, the light-receiving element 370PD for detecting green light may adopt the same structure as the light-emitting element 370R.

[0432] By making the light-receiving element 370PD and the light-emitting element 370R have the same structure, compared with the structure in which the light-receiving element 370PD and the light-emitting element 370R include separately formed layers, the number of deposition processes and the number of masks can be reduced. Therefore, the process and manufacturing cost of the pixel part can be reduced.

[0433] Furthermore, compared to the case where the light-receiving element 370PD and the light-emitting element 370R have a structure including separately formed layers, forming the light-receiving element 370PD and the light-emitting element 370R with the same structure can reduce the possibility of misalignment. This can improve the pixel aperture ratio and light extraction efficiency. Consequently, the lifespan of the light-emitting element can be extended. Additionally, the display device can display high brightness. Furthermore, the clarity of the display device can also be improved.

[0434] The light-emitting layer 383R contains a light-emitting material that emits red light. The active layer 373 contains an organic compound that absorbs light with a wavelength shorter than that of red light (e.g., one or both of green and blue light). Preferably, the active layer 373 contains an organic compound that does not readily absorb red light and absorbs light with a wavelength shorter than that of red light. Thus, red light can be efficiently extracted from the light-emitting element 370R, and the light-receiving element 370PD can detect light with a wavelength shorter than that of red light with high accuracy.

[0435] Additionally, an example is shown in which the light-emitting element 370R and the light-receiving element 370PD in the display device 380B have the same structure, but the light-emitting element 370R and the light-receiving element 370PD may also have optical adjustment layers of different thicknesses.

[0436] The display device 380C shown in Figures 19A and 19B includes a light-receiving element 370SR that emits red (R) light and has a light-receiving function, a light-emitting element 370G, and a light-emitting element 370B. The structures of the light-emitting elements 370G and 370B can refer to the above-described display device 380A, etc.

[0437] The light-emitting element 370SR is sequentially stacked with a pixel electrode 371, a hole injection layer 381, a hole transport layer 382, ​​an active layer 373, a light-emitting layer 383R, an electron transport layer 384, an electron injection layer 385, and a common electrode 375. The light-emitting element 370SR has the same structure as the light-emitting element 370R and the light-receiving element 370PD in the display device 380B described above.

[0438] Figure 19A shows a case where the light-emitting element 370SR is used as a light-emitting element. Figure 19A shows an example where the light-emitting element 370B emits blue light, the light-emitting element 370G emits green light, and the light-emitting element 370SR emits red light.

[0439] Figure 19B shows a case where the light-emitting element 370SR is used as a light-receiving element. Figure 19B shows an example of the light-emitting element 370SR receiving blue light emitted by the light-emitting element 370B and green light emitted by the light-emitting element 370G.

[0440] The light-emitting element 370B, the light-emitting element 370G, and the light-receiving element 370SR all include a pixel electrode 371 and a common electrode 375. In this embodiment, the example will be described where the pixel electrode 371 is used as the anode and the common electrode 375 is used as the cathode. By applying a reverse bias voltage between the pixel electrode 371 and the common electrode 375 to drive the light-receiving element 370SR, light incident on the light-receiving element 370SR can be detected and charge can be generated, thereby extracting it as current.

[0441] It can be said that the light-receiving element 370SR is a structure in which an active layer 373 is added to the light-receiving element. In other words, as long as the process of forming the active layer 373 is added to the process of forming the light-receiving element, the light-receiving element 370SR can be formed at the same time as the light-receiving element. In addition, the light-receiving element and the light-receiving element can be formed on the same substrate. Therefore, the display unit can have one or both of the imaging function and the sensing function without significantly increasing the process.

[0442] There are no restrictions on the stacking order of the light-emitting layer 383R and the active layer 373. Figures 19A and 19B show an example where the hole transport layer 382 has an active layer 373 and the active layer 373 has a light-emitting layer 383R. The stacking order of the light-emitting layer 383R and the active layer 373 can also be interchanged.

[0443] The light-emitting element may also not include at least one of the hole injection layer 381, hole transport layer 382, ​​electron transport layer 384, and electron injection layer 385. In addition, the light-emitting element may also include other functional layers such as hole barrier layer and electron barrier layer.

[0444] In the light-emitting element, a conductive film that transmits visible light is used as the electrode on the side that extracts light. In addition, a conductive film that reflects visible light is used as the electrode on the side that does not extract light.

[0445] The functions and materials of each layer constituting the light-emitting element are the same as those of each layer constituting the light-emitting element and the light-receiving element, so detailed descriptions are omitted.

[0446] Figures 19C to 19G show examples of stacked structures of light-emitting elements.

[0447] The light-emitting element shown in Figure 19C includes a first electrode 377, a hole injection layer 381, a hole transport layer 382, ​​a light-emitting layer 383R, an active layer 373, an electron transport layer 384, an electron injection layer 385, and a second electrode 378.

[0448] Figure 19C shows an example where a light-emitting layer 383R is disposed on the hole transport layer 382 and an active layer 373 is stacked on the light-emitting layer 383R.

[0449] As shown in Figures 19A to 19C, the active layer 373 and the light-emitting layer 383R can also be in contact with each other.

[0450] Furthermore, it is preferable to provide a buffer layer between the active layer 373 and the light-emitting layer 383R. In this case, the buffer layer preferably has both hole transport and electron transport properties. For example, a bipolar material is preferably used as the buffer layer. Alternatively, at least one layer selected from the following can be used as the buffer layer: a hole injection layer, a hole transport layer, an electron transport layer, an electron injection layer, a hole barrier layer, and an electron barrier layer. Figure 19D shows an example of using a hole transport layer 382 as a buffer layer.

[0451] By providing a buffer layer between the active layer 373 and the light-emitting layer 383R, the transfer of excitation energy from the light-emitting layer 383R to the active layer 373 can be suppressed. In addition, the optical path length (cavity length) of the microcavity structure can be adjusted using the buffer layer. Therefore, high luminous efficiency can be obtained from the light-receiving element including the buffer layer between the active layer 373 and the light-emitting layer 383R.

[0452] Figure 19E shows an example of a stacked structure in which a hole transport layer 382-1, an active layer 373, a hole transport layer 382-2, and a light-emitting layer 383R are sequentially stacked on a hole injection layer 381. The hole transport layer 382-2 is used as a buffer layer. The hole transport layer 382-1 and the hole transport layer 381-2 may contain the same material or different materials. Alternatively, a layer that can be used as the buffer layer may be used instead of the hole transport layer 381-2. In addition, the positions of the active layer 373 and the light-emitting layer 383R may be interchanged.

[0453] The light-emitting element shown in FIG19F differs from the light-emitting element shown in FIG19A in that it does not include the hole transport layer 382. Thus, the light-emitting element may also exclude at least one of the holes injection layer 381, holes transport layer 382, ​​electron transport layer 384, and electron injection layer 385. In addition, the light-emitting element may also include other functional layers such as holes barrier layer and electron barrier layer.

[0454] The light-emitting element shown in FIG19G differs from the light-emitting element shown in FIG19A in that it does not include the active layer 373 and the light-emitting layer 383R, but includes a layer 389 that serves as both the light-emitting layer and the active layer.

[0455] As a layer that can be used as both a light-emitting layer and an active layer, for example, a layer containing three materials can be used, namely an n-type semiconductor that can be used in the active layer 373, a p-type semiconductor that can be used in the active layer 373, and a light-emitting material that can be used in the light-emitting layer 383R.

[0456] Furthermore, the absorption band on the lowest energy side of the absorption spectrum of the mixed material of n-type semiconductor and p-type semiconductor preferably does not overlap with the maximum peak of the emission spectrum (PL spectrum) of the luminescent material, and more preferably there is a sufficient distance between them.

[0457] Embodiment 5 In this embodiment, an example of a display device including a light-receiving device or the like according to an embodiment of the present invention will be described.

[0458] 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.

[0459] 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.

[0460] Furthermore, examples of the top surface shape of a sub-pixel include triangles, quadrilaterals (including rectangles and squares), pentagons, and other polygonal shapes with curved 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.

[0461] In a display device in which 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 also emit light as a light source and cause other sub-pixels to display images.

[0462] The pixels shown in Figures 20A, 20B and 20C include sub-pixels G, B, R and PS.

[0463] The pixels shown in Figure 20A are arranged in a bar pattern. The pixels shown in Figure 20B are arranged in a matrix pattern.

[0464] The pixel arrangement shown in Figure 20C has a structure in which three sub-pixels (sub-pixel R, sub-pixel G and sub-pixel S) are arranged vertically next to a sub-pixel (sub-pixel B).

[0465] The pixels shown in Figures 20D, 20E and 20F include sub-pixels G, B, R, IR and PS.

[0466] Figures 20D, 20E and 20F show 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 IR).

[0467] In Figure 20D, three elongated subpixels G, B, and R are arranged horizontally, with subpixel PS and an elongated subpixel IR arranged horizontally below them. In Figure 20E, two elongated subpixels G and R are arranged vertically, with an elongated subpixel B arranged next to them, and an elongated subpixel IR and an elongated subpixel PS arranged horizontally below them. In Figure 20F, three elongated subpixels R, G, and B are arranged horizontally, with an elongated subpixel IR and an elongated subpixel PS arranged horizontally below them. Figures 20E and 20F show the case where subpixel IR has the largest area, while the area of ​​subpixel PS is roughly the same as that of the subpixel.

[0468] Note that the layout of subpixels is not limited to the structures described in Figures 20A to 20F.

[0469] 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-pixel IR includes a light-emitting device that emits infrared light. Sub-pixel PS includes a light-receiving device. Although there is no particular limitation on the wavelength of light detected by sub-pixel PS, the light-receiving device included in sub-pixel PS is preferably sensitive to the light emitted by the light-emitting devices in sub-pixels R, G, B, or IR. For example, it is preferable to detect one or more of the wavelength regions of blue, violet, blue-violet, green, yellow-green, yellow, orange, red, and infrared.

[0470] The light-receiving area of ​​a subpixel (PS) is smaller than the light-emitting area of ​​other subpixels. A smaller light-receiving area results in a narrower imaging range, which can suppress blurring of the image and improve resolution. Therefore, by using a subpixel (PS), high-definition or high-resolution imaging can be achieved. For example, a subpixel (PS) can be used for personal identification using fingerprints, palm prints, irises, vein shapes (including vein and artery shapes), or faces.

[0471] In addition, the subpixel PS can be used in touch sensors (also known as direct touch sensors) or near-touch sensors (also known as hover sensors, hover touch sensors, non-contact sensors, contactless sensors, etc.). For example, the subpixel PS is preferably used to detect infrared light. Thus, touch can be detected even in dark environments.

[0472] Here, a touch sensor or a near-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, a near-touch sensor can detect the object even if it does not contact the display device. 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.

[0473] Because high-definition imaging is performed, it is preferable to place the sub-pixels PS among all the pixels included in the display device. On the other hand, when using sub-pixels PS for touch sensors or near-touch sensors, high precision is not required compared to fingerprint scanning, so it is sufficient to place them among only a portion of the pixels included in the display device. By making the number of sub-pixels PS included in the display device less than the number of sub-pixels R, the detection speed can be improved.

[0474] Figure 20G shows an example of a sub-pixel with a light-receiving device, while Figure 20H shows an example of a sub-pixel with a light-emitting device.

[0475] The pixel circuit PIX1 shown in Figure 20G 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.

[0476] The anode of the light-receiving device PD is electrically connected to wiring V1, and the cathode 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.

[0477] 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 higher 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.

[0478] The pixel circuit PIX2 shown in Figure 20H 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.

[0479] 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.

[0480] 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.

[0481] 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).

[0482] 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.

[0483] For example, the off-state current of an OS transistor with a channel width of 1 μm at room temperature can be less than 1aA (1×10⁻¹⁸ A), less than 1zA (1×10⁻²¹ A), or less than 1yA (1×10⁻²⁴ A). Note that the off-state current of a Si transistor with a channel width of 1 μm at room temperature is greater than or equal to 1fA (1×10⁻¹⁵ A) and less than 1pA (1×10⁻¹² A). Therefore, it can also be said that the off-state current of an OS transistor is about 10 bits lower than that of a Si transistor.

[0484] 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 or polycrystalline silicon, as this can achieve high field-efficiency mobility and higher operating speed.

[0485] 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.

[0486] In Figures 20G and 20H, an n-channel transistor is used as the transistor, but a p-channel transistor can also be used.

[0487] 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.

[0488] 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.

[0489] To increase the luminous brightness of the light-emitting device (EL) included in the pixel circuit, it is necessary to increase the current flowing through the EL. For this purpose, it is necessary to increase the source-drain voltage of the driving transistor included in the pixel circuit. Because the source-drain breakdown voltage of an OS transistor is higher than that of a Si transistor, a high voltage can be applied between the source and drain of the OS transistor. Therefore, by using an OS transistor as the driving transistor included in the pixel circuit, the current flowing through the light-emitting device can be increased, thereby improving the luminous brightness of the light-emitting device.

[0490] Furthermore, when the transistor operates in the saturation region, compared to a Si transistor, an OS transistor can reduce the change in source-drain current in response to changes in the gate-source voltage. Therefore, by using an OS transistor as the driving transistor included in the pixel circuit, the current flowing through the source-drain can be determined in detail based on the change in the gate-source voltage, thus controlling the amount of current flowing through the light-emitting device. As a result, the grayscale of the pixel circuit can be increased.

[0491] Furthermore, regarding the saturation characteristics of the current flowing through a transistor when it operates in the saturation region, compared to a Si transistor, an OS transistor can maintain a stable current (saturation current) even when the source-drain voltage is gradually increased. Therefore, by using an OS transistor as a driving transistor, even if the current-voltage characteristics of a light-emitting device, for example, containing EL material, become non-uniform, a stable current can still flow through the light-emitting device. In other words, when an OS transistor operates in the saturation region, the source-drain current remains almost unchanged even when the source-drain voltage is increased, thus stabilizing the luminous brightness of the light-emitting device.

[0492] As described above, by using an OS transistor as the driving transistor included in the pixel circuit, it is possible to achieve "suppression of black blur", "increase in light emission brightness", "multi-grayscale conversion" and "suppression of non-uniformity of light emission devices".

[0493] A display device according to one embodiment of the present invention may have a variable refresh rate. For example, the power consumption can be reduced by adjusting the refresh rate according to the content displayed on the display device (e.g., adjusting within a range of 0.01Hz to 240Hz). Alternatively, the drive that reduces the power consumption of the display device by reducing the refresh rate may be referred to as an idle stop (IDS) drive.

[0494] Furthermore, the driving frequency of the touch sensor or approximate touch sensor can be changed according to the aforementioned update frequency. For example, when the update frequency of the display device is 120Hz, the driving frequency of the touch sensor or approximate touch sensor can be set to a frequency higher than 120Hz (typically 240Hz). By adopting this structure, power consumption can be reduced and the response speed of the touch sensor or approximate touch sensor can be improved.

[0495] At least a portion of this embodiment may be implemented in combination with other embodiments described in this specification.

[0496] Embodiment 6 In this embodiment, a high-definition display device will be described.

[0497] [Example of Display Panel Structure] Wearable electronic devices used in VR, AR, etc., can provide 3D images by using parallax. In this case, the image for the right eye and the image for the left eye need to be displayed in the right eye's field of view and the left eye's field of view, respectively. Here, the shape of the display section of the display device can be a horizontally elongated rectangle. Pixels located outside the right and left eye's field of view do not contribute to the display, so these pixels are always displayed as black.

[0498] The display panel has two areas, one for the right eye and one for the left eye. Preferably, no pixels are configured in the outer area that does not contribute to the display. This reduces the power consumption required for pixel writing. Furthermore, by reducing the load on source lines, gate lines, etc., a high frame rate display can be achieved. As a result, smooth dynamic images can be displayed, thus improving the sense of realism.

[0499] FIG21A shows an example of the structure of a display panel. In FIG21A, a left-eye display 702L and a right-eye display 702R are disposed on the inner side of a substrate 701. Note that in addition to the display 702L and the display 702R, driving circuits, wiring, ICs, FPCs, etc. may also be disposed on the substrate 701.

[0500] The display unit 702L and display unit 702R shown in FIG21A have a square top surface shape.

[0501] The top surface shape of display units 702L and 702R can also be other regular polygons. Figure 21B shows an example of a regular hexagon, Figure 21C shows an example of a regular octagon, Figure 21D shows an example of a regular decagon, and Figure 21E shows an example of a regular dodecagon. Thus, by using polygons with an even number of angles, the shape of the display unit can be made symmetrical. Note that polygons that are not regular polygons can also be used. Furthermore, regular polygons or polygons with curved corners can also be used.

[0502] Note that since the display unit is composed of pixels arranged in a matrix, the straight lines of the outline of each display unit are not strictly straight lines, but rather have stepped sections. In particular, the straight lines that are not parallel to the pixel arrangement direction have a stepped top surface shape. Note that since the user views the image without seeing the shape of the pixels, even if the tilted outline of the display unit is strictly stepped, it can be considered as a straight line. Similarly, even if the curved sections of the outline of the display unit are strictly stepped, they can be considered as curves.

[0503] Figure 21F shows an example where the top surface of the display unit 702L and the display unit 702R is circular.

[0504] Furthermore, the top surface shapes of display units 702L and 702R can also be asymmetrical. Alternatively, they can be regular polygons.

[0505] Figure 21G shows an example where the top surface shapes of display units 702L and 702R are both asymmetrical octagons. Figure 21H shows an example where they are regular heptagons. Thus, even if the top surface shapes of display units 702L and 702R are asymmetrical, it is preferable that display units 702L and 702R be arranged symmetrically. This provides an image without discomfort.

[0506] In the above description, although the display part is shown as a two-part structure, a continuous shape can also be used.

[0507] FIG21I is an example of the connection of two circular display units 702 in FIG21F. In addition, FIG21J is an example of the connection of two regular octagonal display units 702 in FIG21C.

[0508] The above describes an example of the structure of a display panel.

[0509] 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.

[0510] At least a portion of this embodiment may be implemented in combination with other embodiments described in this specification.

[0511] Embodiment 7 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.

[0512] The metal oxide used in 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.

[0513] Metal oxides can be formed by sputtering, chemical vapor deposition (CVD) such as metal organic chemical vapor deposition (MOCVD), or atomic layer deposition (ALD).

[0514] 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.

[0515] <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.

[0516] 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 referred to as the thin film method or the Seemann-Bohlin method. Hereinafter, the XRD spectrum obtained by GIXD measurement will sometimes be simply referred to as the XRD spectrum.

[0517] 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.

[0518] 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 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.

[0519] <<Structure of Oxide Semiconductors>> Furthermore, when focusing on the structure of oxide semiconductors, the classification of oxide semiconductors sometimes differs from the classifications described above. 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.

[0520] Here, we will explain the details of CAAC-OS, nc-OS and a-like OS mentioned above.

[0521] [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.

[0522] 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.

[0523] 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.

[0524] For example, when performing structural analysis on a CAAC-OS film using an XRD apparatus, a peak representing c-axis alignment is detected at or near 2θ = 31° in out-of-plane XRD measurements using θ / 2θ scanning. 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.

[0525] 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-symmetric positions.

[0526] 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 accommodate distortion due to the low density of oxygen atoms in the ab-plane direction or the change in interatomic bonding distance caused by the substitution of metal atoms.

[0527] 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.

[0528] 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.

[0529] [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.

[0530] [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.

[0531] <<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.

[0532] [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.

[0533] 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.

[0534] 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.

[0535] 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.

[0536] Note that sometimes the clear boundary between the first region and the second region mentioned above cannot be observed.

[0537] 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.

[0538] 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%.

[0539] 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 and mixed region of In-dominant components (first region) and Ga-dominant components (second region) can be identified.

[0540] 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 the conductivity of 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.

[0541] 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 a metal oxide, leakage current can be suppressed.

[0542] 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.

[0543] Furthermore, transistors using CAC-OS exhibit high reliability. Therefore, CAC-OS is best suited for various semiconductor devices such as display devices.

[0544] 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.

[0545] <Transistor with oxide semiconductor> Next, we will explain the case of using the above-mentioned oxide semiconductor as a transistor.

[0546] 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.

[0547] Preferably, an oxide semiconductor with a low carrier concentration is used in the 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. In addition, oxide semiconductors with low carrier concentration are sometimes referred to as high purity or substantially high purity oxide semiconductors.

[0548] 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.

[0549] 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.

[0550] 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 percent can be considered impurities.

[0551] <Impurities> Here, the effects of various impurities in oxide semiconductors are explained.

[0552] 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.

[0553] 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.

[0554] When an oxide semiconductor contains nitrogen, electrons are easily 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, measured using 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.

[0555] 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, measured using 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.

[0556] By using oxide semiconductors with sufficiently reduced impurities in the channel formation region of the transistor, the transistor can have stable electrical characteristics.

[0557] At least a portion of this embodiment may be implemented in combination with other embodiments described in this specification.

[0558] Embodiment 8 In this embodiment, an electronic device according to an embodiment of the present invention will be described using Figures 22 to 25.

[0559] The electronic device of this embodiment includes a display device according to one embodiment of the present invention. The display device according to one embodiment of the present invention is easily made high-definition, high-resolution, and large-scale. Therefore, the display device according to one embodiment of the present invention can be used in the display section of various electronic devices.

[0560] In addition, the display device of one embodiment of the present invention can be manufactured at low cost, thereby reducing the manufacturing cost of electronic devices.

[0561] As electronic devices, in addition to electronic devices with large screens such as televisions, desktop or laptop personal computers, monitors for computers, digital signage, and large game consoles such as pinball machines, examples include digital cameras, digital camcorders, digital photo frames, mobile phones, portable game consoles, portable information terminals, and audio playback devices.

[0562] In particular, because 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, for example, information terminal devices (wearable devices) such as watch-type and bracelet-type devices, wearable devices that can be worn on the head, VR devices such as head-mounted displays, and AR devices such as glasses-type devices. In addition, SR (Substitutional Reality) devices and MR (Mixed Reality) devices can also be cited as wearable devices.

[0563] A display device according to one embodiment of the present invention preferably has extremely high resolution, such as HD (1280×720 pixels), FHD (1920×1080 pixels), WQHD (2560×1440 pixels), WQXGA (2560×1600 pixels), 4K2K (3840×2160 pixels), 8K4K (7680×4320 pixels), etc. Particularly preferred is 4K2K, 8K4K, or higher resolution. Furthermore, the pixel density (clarity) in the display device according to one embodiment of the present invention is preferably 300 ppi or more, more preferably 500 ppi or more, further preferably 1000 ppi or more, even more preferably 2000 ppi or more, still more preferably 3000 ppi or more, still more preferably 5000 ppi or more, and still more preferably 7000 ppi or more. By using the aforementioned high-resolution or high-definition display devices, the sense of realism and depth can be further enhanced in personal electronic devices such as portable or home-use devices.

[0564] The electronic device of this embodiment 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.

[0565] The electronic device of this embodiment may also include an antenna. By receiving signals through the antenna, images and information can be displayed on the display unit. In addition, when the electronic device includes an antenna and a secondary battery, contactless power transmission can be performed using the antenna.

[0566] The electronic device of this embodiment may also include a sensor (which has the function of sensing, detecting and measuring factors such as force, displacement, position, velocity, acceleration, angular velocity, rotational speed, distance, light, liquid, magnetism, temperature, chemical substance, sound, time, hardness, electric field, current, voltage, power, radiation, flow rate, humidity, tilt, vibration, odor or infrared radiation).

[0567] The electronic device of this embodiment may have various functions. For example, it may have the following functions: displaying various information (still images, moving images, text images, etc.) on the display unit; touch panel function; displaying calendar, date or time, etc.; executing various software (programs); performing wireless communication function; reading programs or data stored in the storage medium; etc.

[0568] The electronic device 6500 shown in Figure 22A is a portable information terminal device that can be used as a smartphone.

[0569] The electronic device 6500 includes a housing 6501, a display unit 6502, a power button 6503, a button 6504, a speaker 6505, a microphone 6506, a camera 6507, and a light source 6508, etc. The display unit 6502 has a touch panel function.

[0570] A display device according to an embodiment of the present invention can be applied to the display unit 6502.

[0571] Figure 22B is a cross-sectional view of one end of the microphone 6506 including the housing 6501.

[0572] A light-transmitting protective member 6510 is provided on one side of the display surface of the housing 6501. A display panel 6511, an optical member 6512, a touch sensor panel 6513, a printed circuit board 6517, a battery 6518, etc. are provided in the space surrounded by the housing 6501 and the protective member 6510.

[0573] The display panel 6511, optical component 6512 and touch sensor panel 6513 are fixed to the protective component 6510 using an adhesive layer (not shown).

[0574] In the area outside the display unit 6502, a portion of the display panel 6511 is folded back, and this folded portion is connected to an FPC 6515. An IC 6516 is mounted on the FPC 6515. The FPC 6515 is connected to terminals provided on a printed circuit board 6517.

[0575] The display panel 6511 can use a flexible display (a flexible display device) according to one embodiment of the present invention. This allows for the realization of an extremely lightweight electronic device. Furthermore, since the display panel 6511 is extremely thin, a large-capacity battery 6518 can be installed while minimizing the thickness of the electronic device. Additionally, by folding a portion of the display panel 6511 to provide a connection portion with the FPC 6515 on the back of the pixel portion, a narrow-bezel electronic device can be realized.

[0576] Figure 23A shows an example of a television set. In the television set 7100, a display unit 7000 is assembled in the housing 7101. The structure in which the housing 7101 is supported by a bracket 7103 is shown here.

[0577] A display device according to an embodiment of the present invention can be applied to the display unit 7000.

[0578] The television 7100 shown in FIG. 23A can be operated using the operation switch provided in the housing 7101 and the separately provided remote control 7111. Furthermore, a touch sensor can be provided in the display unit 7000, allowing operation of the television 7100 by touching the display unit 7000 with a finger or the like. Additionally, the remote control 7111 can have a display unit that displays information output from the remote control 7111. Channel and volume controls can be performed using the operation keys or touch panel provided in the remote control 7111, and the images displayed on the display unit 7000 can also be manipulated.

[0579] In addition, the television set 7100 is equipped with a receiver and a modem. It can receive general television broadcasts by using the receiver. Furthermore, it can connect to a wired or wireless communication network by using the modem to conduct one-way (from sender to receiver) or two-way (between sender and receiver or between receivers, etc.) information communication.

[0580] Figure 23B shows an example of a laptop computer. The laptop computer 7200 includes a casing 7211, a keyboard 7212, a pointing device 7213, an external connection port 7214, etc. A display unit 7000 is assembled in the casing 7211.

[0581] A display device according to an embodiment of the present invention can be applied to the display unit 7000.

[0582] Figures 23C and 23D show an example of a digital signage.

[0583] The digital signage 7300 shown in Figure 23C includes a housing 7301, a display unit 7000, and a speaker 7303. It may also include LED lights, operation keys (including a power switch or operation switch), connection terminals, various sensors, a microphone, etc.

[0584] Figure 23D shows a digital signboard 7400 disposed on a cylindrical column 7401. The digital signboard 7400 includes a display section 7000 disposed along the curved surface of the column 7401.

[0585] In Figures 23C and 23D, a display device including a transistor according to an embodiment of the present invention can be applied to the display unit 7000.

[0586] The larger the display unit 7000, the more information it can provide at once. The larger the display unit 7000, the easier it is to attract people's attention, for example, it can improve the effectiveness of advertising.

[0587] By using a touch panel for the display unit 7000, not only can static or dynamic images be displayed on the display unit 7000, but users can also operate it intuitively, which is superior. In addition, when used to provide information such as route information or traffic information, intuitive operation can improve ease of use.

[0588] As shown in Figures 23C and 23D, the digital signage 7300 or 7400 is preferably able to wirelessly communicate with a user's smartphone or other information terminal device 7311 or 7411. For example, advertising information displayed on the display unit 7000 can be displayed on the screen of the information terminal device 7311 or 7411. Furthermore, the display on the display unit 7000 can be switched by operating the information terminal device 7311 or 7411.

[0589] Furthermore, the game can be executed on the digital signage 7300 or 7400 using the screen of the information terminal device 7311 or 7411 as the operating unit (controller). Thus, multiple users can participate in the game simultaneously and enjoy the experience.

[0590] Figure 24A is an external view of a camera 8000 equipped with a viewfinder 8100.

[0591] The camera 8000 includes a housing 8001, a display unit 8002, an operation button 8003, a shutter button 8004, etc. Furthermore, the camera 8000 is equipped with a detachable lens 8006. In the camera 8000, the lens 8006 and the housing can also be formed as a single unit.

[0592] The camera 8000 can take pictures by pressing the shutter button 8004 or touching the display 8002, which is used as a touch panel.

[0593] The housing 8001 includes an insert with electrodes, which can be connected to the viewfinder 8100 and to a flash unit, etc.

[0594] The viewfinder 8100 includes a housing 8101, a display unit 8102, and buttons 8103, etc.

[0595] The housing 8101 is mounted to the camera 8000 by means of an inserter that fits into the camera 8000. The viewfinder 8100 can display images received from the camera 8000 on the display unit 8102.

[0596] Button 8103 is used as a power button, etc.

[0597] The display device according to one embodiment of the present invention can be used in the display unit 8002 of a camera 8000 and the display unit 8102 of a viewfinder 8100. Alternatively, a viewfinder may be built into the camera 8000.

[0598] Figure 24B is an external view of the head-mounted display 8200.

[0599] The head-mounted display 8200 includes a mounting section 8201, a lens 8202, a main body 8203, a display section 8204, and a cable 8205. In addition, a battery 8206 is built into the mounting section 8201.

[0600] Power is supplied from the battery 8206 to the main body 8203 via cable 8205. The main body 8203 is equipped with a wireless receiver, etc., and can display the received image information, etc., on the display unit 8204. In addition, the main body 8203 is equipped with a camera, thereby utilizing information from the user's eyeball or eyelid movements as an input method.

[0601] Furthermore, multiple electrodes can be provided at the location of the mounting unit 8201 that is touched by the user to detect the current flowing through the electrodes according to the user's eye movements, thereby realizing the function of recognizing the user's gaze. In addition, it can also have the function of monitoring the user's pulse based on the current flowing through the electrodes. The mounting unit 8201 can have various sensors such as temperature sensors, pressure sensors, and acceleration sensors, and can also have the function of displaying the user's biometric information on the display unit 8204 or the function of changing the image displayed on the display unit 8204 in sync with the user's head movements.

[0602] A display device according to an embodiment of the present invention can be applied to the display unit 8204.

[0603] Figures 24C to 24E are external views of the head-mounted display 8300. The head-mounted display 8300 includes a housing 8301, a display unit 8302, a strap-shaped fixing tool 8304, and a pair of lenses 8305.

[0604] The user can see the display on the display unit 8302 through the lens 8305. Preferably, the display unit 8302 is curved. This allows the user to experience a high degree of realism. Furthermore, by viewing the images displayed on different areas of the display unit 8302 through the lens 8305, three-dimensional displays utilizing parallax can be performed. In addition, one embodiment of the present invention is not limited to a structure with one display unit 8302, and two display units 8302 may be provided, with one display unit for each of the user's eyes.

[0605] The display device according to one embodiment of the present invention can be used in the display unit 8302. The display device according to one embodiment of the present invention can also achieve extremely high resolution. For example, as shown in FIG24E, even when the display is magnified using the lens 8305, the pixels are not easily visible to the user. That is to say, the display unit 8302 can be used to enable the user to see images with a higher degree of realism.

[0606] Figure 24F is an external view of the goggle-type head-mounted display 8400. The head-mounted display 8400 includes a pair of housings 8401, a mounting part 8402, and a buffer member 8403. Each of the pair of housings 8401 is provided with a display part 8404 and a lens 8405. By displaying different images on the pair of display parts 8404, three-dimensional display utilizing parallax can be performed.

[0607] The user can see the display on the display unit 8404 through the lens 8405. The lens 8405 has a focus adjustment mechanism, which can adjust the position according to the user's vision. The display unit 8404 is preferably square or a horizontally elongated rectangle. This can improve the realism.

[0608] The mounting part 8402 is preferably plastic and elastic so that it can be adjusted according to the user's face size without falling off. Additionally, a portion of the mounting part 8402 preferably has a vibration mechanism that functions as a bone conduction headphone. Thus, simply installing the headphone allows users to enjoy video and sound without the need for headphones, speakers, or other audio equipment. Furthermore, it may also have the function of wirelessly outputting audio data to the housing 8401.

[0609] The mounting part 8402 and the buffer member 8403 are the parts that come into contact with the user's face (forehead, cheeks, etc.). By ensuring a close contact between the buffer member 8403 and the user's face, light leakage can be prevented, thereby further enhancing the immersive experience. The buffer member 8403 is preferably made of a soft material to ensure a close contact with the user's face when the user wears the head-mounted display 8400. For example, materials such as rubber, silicone rubber, polyurethane, and sponge can be used. Furthermore, when a component with a surface covered by cloth or leather (natural or synthetic leather) is used as the buffer member 8403, gaps are less likely to form between the user's face and the buffer member 8403, thus appropriately preventing light leakage. Additionally, using such a material not only provides a skin-friendly feel but also prevents the user from feeling cold when wearing the device, especially in colder seasons. It is preferable when components that come into contact with the user's skin, such as the cushioning member 8403 or the mounting part 8402, are detachable, making them easy to clean or replace.

[0610] The electronic device shown in Figures 25A to 25F includes a housing 9000, a display unit 9001, a speaker 9003, operation keys 9005 (including a power switch or operation switch), a connection terminal 9006, a sensor 9007 (which has the function of sensing, detecting or measuring factors such as force, displacement, position, velocity, acceleration, angular velocity, rotational speed, distance, light, liquid, magnetism, temperature, chemical substance, sound, time, hardness, electric field, current, voltage, power, radiation, flow rate, humidity, tilt, vibration, odor or infrared radiation), a microphone 9008, etc.

[0611] The electronic devices shown in Figures 25A to 25F have various functions. For example, they may have the following functions: displaying various information (still images, moving images, and text images, etc.) on a display unit; touch panel function; displaying calendars, dates, or times, etc.; control processing via various software (programs); wireless communication function; reading and processing programs or data stored in a storage medium; etc. Note that the functions of the electronic device are not limited to the above functions, but can have various functions. The electronic device may include multiple display units. In addition, a camera or the like may be installed in the electronic device to enable it to have the following functions: capturing still images or moving images and storing the captured images in a storage medium (external storage medium or storage medium built into the camera); displaying the captured images on a display unit; etc.

[0612] The display device of one embodiment of the present invention can be used in the display unit 9001.

[0613] The electronic devices shown in Figures 25A to 25F will now be described in detail.

[0614] Figure 25A is a perspective view showing a portable information terminal 9101. The portable information terminal 9101 can be used, for example, as a smartphone. Note that a speaker 9003, a connection terminal 9006, a sensor 9007, etc., can also be provided in the portable information terminal 9101. Furthermore, as a portable information terminal 9101, text and image information can be displayed on multiple surfaces. Examples of three illustrations 9050 are shown in Figure 25A. In addition, information 9051, shown as a dashed rectangle, can be displayed on other surfaces of the display unit 9001. Examples of information 9051 include notifications of received emails, SNS messages, or phone calls; the subject of emails, SNS messages, etc.; the sender's name of emails or SNS messages, etc.; the date; the time; the remaining battery level; and the display of antenna signal strength, etc. Alternatively, illustrations 9050 can be displayed in the same locations where information 9051 is displayed.

[0615] Figure 25B is a perspective view showing a portable information terminal 9102. The portable information terminal 9102 has the function of displaying information on three or more surfaces of the display unit 9001. Here, examples are shown where information 9052, information 9053, and information 9054 are displayed on different surfaces. For example, when the portable information terminal 9102 is placed in a jacket pocket, the user can check information 9053 displayed in a position seen from above the portable information terminal 9102. The user can check this display without taking the portable information terminal 9102 out of the pocket, thereby determining whether to answer a phone call.

[0616] Figure 25C is a perspective view showing a watch-type portable information terminal 9200. The portable information terminal 9200 can be used, for example, as a smartwatch (registered trademark). Furthermore, the display surface of the display unit 9001 is curved, allowing display along its curved surface. Additionally, the portable information terminal 9200 can perform hands-free calls, for example, by communicating with a headset capable of wireless communication. Furthermore, by utilizing the connection terminal 9006, the portable information terminal 9200 can transmit data and charge with other information terminals. Charging can also be performed wirelessly.

[0617] Figures 25D to 25F are perspective views showing the foldable portable information terminal 9201. Furthermore, Figure 25D is a perspective view of the portable information terminal 9201 in its unfolded state, Figure 25F is a perspective view of its folded state, and Figure 25E is a perspective view of the intermediate state during the transition from one of the states in Figures 25D and 25F to the other. The portable information terminal 9201 offers good portability in its folded state, and in its unfolded state, it provides a large, seamless display area, resulting in excellent browsing capabilities. The display unit 9001 included in the portable information terminal 9201 is supported by three housings 9000 connected by hinges 9055. The display unit 9001 can be bent, for example, within a radius of curvature of 0.1 mm or more and 150 mm or less.

[0618] 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.

[0619] At least a portion of this embodiment can be appropriately combined with other embodiments described in this specification. [Example]

[0620] In this embodiment, a display panel according to one embodiment of the present invention is manufactured.

[0621] [Manufacturing of Display Panel] The display panel is manufactured according to the method shown in Embodiment 1. Specifically, a glass substrate is prepared on which pixel circuits including transistors and wiring, as well as pixel electrodes, are formed. Then, after forming a first common layer, a red EL layer, a green EL layer, a blue EL layer, and a PD layer are formed respectively using a vacuum evaporation method employing FMM. Then, a second common layer and a sacrificial layer are formed on each EL layer and PD layer. A photoresist mask is formed on the sacrificial layer at the position overlapping with the pixel electrode using photolithography. After etching the sacrificial layer, the photoresist mask is removed. Then, the EL layer and PD layer are etched with the sacrificial layer as a mask to form slits, and then the sacrificial layer is removed. Next, an insulating layer and a resin layer are formed inside the slits, and then a third common layer and a common electrode are formed.

[0622] As the light-emitting element, organic EL elements of red (R), green (G), and blue (B) are used. The light-emitting element is a top-emitting type. The light-receiving element uses an organic photodiode. As the transistor, a transistor using In-Ga-Zn oxide semiconductor is used to form the channel.

[0623] In the manufactured display device, the display unit has a diagonal size of 7.99 inches, a pixel count of 1080 × 2160, a pixel size of 84 μm × 84 μm, and a resolution of 302 ppi. The display device includes a display gate driver, a demultiplexer, a sensor scan driver, and a readout circuit, etc., while the display source driver and AD conversion circuit are mounted externally.

[0624] [Display Results] Figure 26A shows the display results of the image, which can display a good full-color image.

[0625] [Video Capture Result] A video was taken with a finger placed on the display surface of the manufactured display device. Figure 26B shows the video capture result. Figure 26B shows a magnified portion of the captured image. Furthermore, to protect personal information, a portion of Figure 26B has been pixelated.

[0626] As shown in Figure 26B, fingerprints can be clearly captured.

[0627] It can be confirmed that the display device of one embodiment of the present invention can not only display images but also clearly capture objects in contact with the display surface.

[0628] [Noise Measurement] Next, the measurement results of the noise of the sensor of the manufactured display device will be explained.

[0629] In a display device, a light-emitting element and a light-receiving element (also called a sensor element) are arranged adjacent to each other. When taking a picture, exposure is performed while the light-emitting element, which serves as the light source, is emitting light. Therefore, the main causes of noise in the sensor are side leakage between the light-emitting element and the light-receiving element, and stray light within the display device. The lower the noise, the higher the signal-to-noise ratio (S / N ratio), thereby enabling high-precision imaging.

[0630] In order to investigate the main causes of sensor noise, the sensor's output voltage was measured when the voltage applied to the light-emitting element was changed without a photographic object being placed. Note that, for comparison, a display device (Ref.) without a slit was also manufactured and the same measurement was performed on it.

[0631] Figure 27 shows the measurement results. In Figure 27, the horizontal axis represents the applied voltage [V] to the light-emitting element (OLED), and the vertical axis represents the output voltage [V] of the sensor.

[0632] Here, the light-emitting threshold of the light-emitting element is approximately 2.6V (indicated by the dashed line), and it does not emit light below this voltage (non-light-emitting region). Therefore, it can be inferred that the noise detected in the range below approximately 2.6V is noise caused by side leakage. On the other hand, since the light-emitting element emits light in the range above approximately 2.6V (light-emitting region), it can be inferred that the noise detected in this range is noise caused by both side leakage noise and stray light noise.

[0633] When focusing on the non-light-emitting area, the output voltage of the display device of this embodiment is almost undetectable regardless of the applied voltage to the OLED. On the other hand, in the comparative example, noise was detected even when the voltage applied to the OLED was very small. This confirms that the display device of this embodiment effectively suppresses side leakage by disconnecting the light-emitting element and the light-receiving element with a slit.

[0634] Furthermore, when focusing on the light-emitting area, both the display device of this embodiment and the comparative example tend to have increased noise as the applied voltage to the OLED increases. However, it was found that the display device of this embodiment has less noise than the comparative example, less than half the noise of the comparative example.

[0635] As can be confirmed from the above, in one embodiment of the present invention, side leakage is suppressed and high S / N ratio imaging can be achieved. [Simplified Explanation of the Diagram]

[0022] Figures 1A to 1D are diagrams showing examples of the structure of a display device. Figures 2A and 2B are diagrams showing examples of the structure of a display device. Figures 3A and 3B 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 and 5B are diagrams showing examples of the structure of a display device. Figures 6A and 6B are diagrams showing examples of the structure of a display device. Figure 7 is a diagram showing an example of the structure of a display device. Figures 8A to 8C are diagrams showing examples of a manufacturing method for a display device. Figures 9A to 9C are diagrams showing examples of a manufacturing method for a display device. Figures 10A to 10C are diagrams showing examples of a manufacturing method for a display device. Figures 11A to 11C are diagrams showing examples of a manufacturing method for a display device. [Figs. 12A] to [Figs. 12C] are diagrams illustrating examples of manufacturing methods for a display device. [Fig. 13] is a diagram illustrating an example of the structure of a display device. [Fig. 14A] is a diagram illustrating an example of the structure of a display device. [Fig. 14B] is a diagram illustrating an example of the structure of a transistor. [Figs. 15A], [Figs. 15B] and [Figs. 15D] are cross-sectional views illustrating examples of display devices. [Figs. 15C] and [Figs. 15E] are diagrams illustrating examples of images. [Figs. 15F] to [Figs. 15H] are top views illustrating examples of pixels. [Fig. 16A] is a cross-sectional view illustrating an example of the structure of a display device. [Figs. 16B] to [Figs. 16D] are top views illustrating an example of a pixel. [Fig. 17A] is a cross-sectional view illustrating an example of the structure of a display device. [Figs. 17B] to [Figs. 17I] are top views illustrating an example of a pixel. [Figs. 18A] and [Figs. 18B] are diagrams illustrating examples of the structure of a display device. [Figures 19A] to [19G] are diagrams illustrating examples of the structure of a display device. [Figures 20A] to [20F] are diagrams illustrating examples of pixels. [Figures 20G] and [20H] are diagrams illustrating examples of the circuit diagram of a pixel. [Figures 21A] to [21J] are diagrams illustrating examples of the structure of a display device. [Figures 22A] and [22B] are diagrams illustrating an example of an electronic device. [Figures 23A] to [23D] are diagrams illustrating an example of an electronic device. [Figures 24A] to [24F] are diagrams illustrating an example of an electronic device. [Figures 25A] to [25F] are diagrams illustrating an example of an electronic device. [Figure 26A] is a display photograph of the display device of the embodiment. [Figure 26B] is a photographic result of the embodiment. [Figure 27] is a measurement result of the noise of the sensor in the embodiment.

Claims

1. A display device, comprising: First light-emitting element; The light-emitting element includes a first pixel electrode, a first organic layer, and a common electrode stacked sequentially in the first light-emitting element. The light-receiving element includes a second pixel electrode, a second organic layer, and the common electrode stacked sequentially in the second light-receiving element. The first organic layer includes a first light-emitting layer, and the second organic layer includes a photoelectric conversion layer. The region between the first light-emitting element and the light-receiving element includes a first layer and a second layer. The first layer overlaps with the second organic layer and contains the same material as the first organic layer. The second layer overlaps with the first organic layer and contains the same material as the second organic layer. In the region between the first light-emitting element and the light-receiving element, the ends of the first organic layer and the ends of the second organic layer are opposite each other. In the region between the first light-emitting element and the light-receiving element, the ends of the second organic layer and the ends of the second organic layer are opposite each other. The first layer has a portion that overlaps with the second pixel electrode and the second organic layer, and the second layer has a portion that overlaps with the first pixel electrode and the first organic layer.

2. The display device as described in claim 1 further includes: A second light-emitting element, wherein a third pixel electrode, a third organic layer, and a common electrode are sequentially stacked in the second light-emitting element, the third organic layer including the second light-emitting layer, and a third layer and a fourth layer in the region between the second light-emitting element and the first light-emitting element, the third layer overlapping the third organic layer and containing the same material as the first organic layer, the fourth layer overlapping the first organic layer and containing the same material as the third organic layer, the end of the first organic layer facing the end of the third layer in the region between the second light-emitting element and the first light-emitting element, the end of the third organic layer facing the end of the fourth layer in the region between the second light-emitting element and the first light-emitting element, the third layer having a portion overlapping the third pixel electrode and the third organic layer, and the fourth layer having a portion overlapping the first pixel electrode and the first organic layer.

3. The display device as described in claim 1 or 2 further includes: The connection between the first light-emitting element and the light-receiving element includes an electrode made of the same material as the first pixel electrode. The first layer is disposed separately from the electrode, the second layer is disposed separately from the electrode, and the electrode is electrically connected to the common electrode.

4. The display device according to any one of claims 1 to 3 further includes: A resin layer, wherein the resin layer is located in the region between the first light-emitting element and the light-receiving element, the end of the first organic layer is sandwiched between the end of the first layer and the resin layer is opposed to each other, and the end of the second organic layer is sandwiched between the end of the second layer and the resin layer is opposed to each other.

5. The display device according to any one of claims 1 to 4 further includes: A first insulating layer is located between the first light-emitting element and the light-receiving element, and the first insulating layer is in contact with the ends of the first organic layer, the ends of the second organic layer, the ends of the first layer, and the ends of the second layer.

6. A method for manufacturing a display device, comprising the following steps: a first process of forming a first pixel electrode and a second pixel electrode in parallel; a second process of forming an island-shaped first organic layer on the first pixel electrode using a first metal mask; a third process of forming an island-shaped second organic layer on the second pixel electrode and the first organic layer using a second metal mask; a fourth process of etching the first organic layer and the second organic layer in a region between the first pixel electrode and the second pixel electrode; and a fifth process of forming a common electrode by covering the first organic layer and the second organic layer, wherein... In the second process, the first organic layer is formed by overlapping a portion of the first organic layer with the second pixel electrode. In the third process, the second organic layer is formed by overlapping a portion of the second organic layer with the first pixel electrode. The first organic layer contains a luminescent organic compound, and the second organic layer contains a photoelectric conversion material.

7. The method of manufacturing the display device as described in claim 6 further includes: The process following the fourth process and preceding the fifth process includes a sixth process in which a resin layer is formed within the slits created by the etching.

8. A method for manufacturing a display device as claimed in claim 7, wherein a photosensitive organic resin is used as the resin layer.

9. The method of manufacturing the display device as described in claim 7 or 8 further includes: The process following the fourth process and preceding the sixth process includes a seventh process in which a first insulating layer is formed by contacting the sides of the first organic layer and the sides of the second organic layer exposed by the etching.

10. A method for manufacturing a display device as claimed in claim 9, wherein a metal oxide film formed by atomic layer deposition is used as the first insulating layer.