Display device, display module, and electronic device

Abstract

Provided is a display device that makes it possible for a user to see the background and that also makes it possible to perform imaging at a high sensitivity. According to the present invention, a display device has, on a substrate that transmits visible light, a first light-emitting element, a second light-emitting element that is adjacent to the first light-emitting element, a light-receiving element that is adjacent to the second light-emitting element, a first organic layer that is provided between the second light-emitting element and the light-receiving element, and a second organic layer that is provided between the first light-emitting element and the second light-emitting element. The first light-emitting element is formed by layering, in order, a first pixel electrode, a first light-emitting layer, and a shared electrode. The second light-emitting element is formed by layering, in order, a second pixel electrode, a second light-emitting layer, and a shared electrode. The light-receiving element is formed by layering, in order, a third pixel electrode, a photoelectric conversion layer, and a shared electrode. The transmittance of light of at least a portion of the wavelengths of visible light is lower at the first organic layer than at the second organic layer.

Description

Display device, display device manufacturing method, display module, and electronic device

[0001] 1. Field of the Invention One embodiment of the present invention relates to a display device, an imaging device, a display device having an imaging function, a display module, or an electronic device.

[0002] Note that one embodiment of the present invention is not limited to the above technical field. Examples of the technical field of one embodiment of the present invention disclosed in this specification and the like include semiconductor devices, display devices, light-emitting devices, power storage devices, memory devices, electronic devices, lighting devices, input devices, input / output devices, driving methods thereof, and manufacturing methods thereof. A semiconductor device refers to any device that can function by utilizing semiconductor characteristics.

[0003] In recent years, display devices have been required to have higher definition in order to display high-resolution images. Furthermore, in information terminal devices such as smartphones, tablet terminals, and notebook PCs (personal computers), display devices are required to have not only high definition but also low power consumption. Furthermore, display devices that not only display images but also have various additional functions, such as a touch sensor function and a function for capturing fingerprints for authentication, are also required.

[0004] As a display device, for example, a light-emitting device having a light-emitting element has been developed. Light-emitting elements (also referred to as EL elements) utilizing the electroluminescence (EL) phenomenon have features such as being easily thin and lightweight, being capable of responding quickly to input signals, and being capable of being driven using a DC constant voltage power supply, and are therefore applied to display devices. For example, Patent Document 1 discloses a flexible light-emitting device using an organic EL element.

[0005] Also, Non-Patent Document 1 discloses a method for fabricating organic optoelectronic devices using standard UV photolithography.

[0006] JP 2014-197522 A

[0007] B. Lamprecht et al. , “Organic optoelectronic device fabrication using standard UV photolithography” phys. stat. sol. (RRL) 2, No. 1, p. 16-18 (2008)

[0008] An object of one embodiment of the present invention is to provide a display device or an imaging device capable of capturing an image with high sensitivity. Another object of one embodiment of the present invention is to provide a high-resolution display device or an imaging device. Another object of one embodiment of the present invention is to provide a display device or an imaging device with a high aperture ratio. Another object of one embodiment of the present invention is to provide a display device that allows a user to view a view behind the display device. Another object of one embodiment of the present invention is to provide a display device with high light extraction efficiency. Another object of one embodiment of the present invention is to provide a display device with high display quality. Another object of one embodiment of the present invention is to provide a display device that can acquire biometric information such as a fingerprint. Another object of one embodiment of the present invention is to provide a display device that functions as a touch sensor. Another object of one embodiment of the present invention is to provide a highly functional display device. Another object of one embodiment of the present invention is to provide a highly reliable display device or imaging device. Another object of one embodiment of the present invention is to provide a display device or an imaging device having a novel structure.Another object of one embodiment of the present invention is to provide an electronic device including the display device or the imaging device.Another object of one embodiment of the present invention is to provide a manufacturing method of the display device, the imaging device, or the electronic device.

[0009] Note that the description of these problems does not preclude the existence of other problems. Note that one embodiment of the present invention does not necessarily solve all of these problems. Note that problems other than these can be extracted from the description in the specification, drawings, claims, etc.

[0010] One embodiment of the present invention includes, over a substrate that transmits visible light, a first light-emitting element, a second light-emitting element adjacent to the first light-emitting element, a light-receiving element adjacent to the second light-emitting element, a first organic layer provided between the second light-emitting element and the light-receiving element, and a second organic layer provided between the first light-emitting element and the second light-emitting element, wherein the first light-emitting element has a first pixel electrode, a first light-emitting layer over the first pixel electrode, and a common electrode over the first light-emitting layer; and the second light-emitting element has a second pixel electrode, The display device has a second light-emitting layer on the second pixel electrode and a common electrode on the second light-emitting layer, the light-receiving element has a third pixel electrode, a photoelectric conversion layer on the third pixel electrode, and a common electrode on the photoelectric conversion layer, the common electrode is provided on the first organic layer and the second organic layer, the common electrode is transparent to visible light, and the transmittance of light of a specific wavelength, which is at least a portion of the wavelengths of visible light, in the first organic layer is lower than the transmittance of light of the specific wavelength in the second organic layer.

[0011] Alternatively, one embodiment of the present invention includes, over a substrate that transmits visible light, a first light-emitting element, a second light-emitting element adjacent to the first light-emitting element, a light-receiving element adjacent to the second light-emitting element, a first organic layer provided between the second light-emitting element and the light-receiving element, and a second organic layer provided between the first light-emitting element and the second light-emitting element, wherein the first light-emitting element includes a first pixel electrode, a first light-emitting layer over the first pixel electrode, and a common electrode over the first light-emitting layer; a second pixel electrode, a second light-emitting layer on the second pixel electrode, and a common electrode on the second light-emitting layer, the common electrode being translucent to visible light, the light-receiving element having a third pixel electrode, a photoelectric conversion layer on the third pixel electrode, and the common electrode on the photoelectric conversion layer, and the transmittance of light of at least one color of red, green, and blue in the first organic layer is lower than the transmittance in the second organic layer.

[0012] Alternatively, in the above aspect, the first and second pixel electrodes may be transparent to visible light.

[0013] Alternatively, in the above embodiment, the ends of the first to third pixel electrodes may have a tapered shape, the first light-emitting layer may cover the end of the first pixel electrode, the second light-emitting layer may cover the end of the second pixel electrode, and the photoelectric conversion layer may cover the end of the third pixel electrode.

[0014] Alternatively, in the above aspect, the first light-emitting layer may have a first tapered portion between an end of the first pixel electrode and the second organic layer, the second light-emitting layer may have a second tapered portion between an end of the second pixel electrode and the second organic layer, and the photoelectric conversion layer may have a third tapered portion between an end of the third pixel electrode and the first organic layer.

[0015] Alternatively, in the above embodiment, a first carrier transport layer may be provided on the first light-emitting layer, a second carrier transport layer on the second light-emitting layer, and a third carrier transport layer on the photoelectric conversion layer.

[0016] Alternatively, in the above aspect, a common layer may be provided on the first carrier transport layer, the second carrier transport layer, the third carrier transport layer, the first organic layer, and the second organic layer, and a common electrode may be provided on the common layer.

[0017] Alternatively, in the above embodiment, the common layer may include a carrier injection layer.

[0018] Another aspect of the present invention is a display module including the display device according to one aspect of the present invention and at least one of a connector and an integrated circuit.

[0019] An electronic device including a display module according to one embodiment of the present invention and at least one of a battery, a camera, a speaker, and a microphone is also one embodiment of the present invention.

[0020] Alternatively, one embodiment of the present invention includes forming a first pixel electrode, a second pixel electrode, and a third pixel electrode over a substrate that transmits visible light, forming a first light-emitting film over the substrate and the first to third pixel electrodes, forming a first sacrificial film over the first light-emitting film, and processing the first light-emitting film and the first sacrificial film to form a first light-emitting layer and a first sacrificial layer over the first light-emitting layer, forming a second light-emitting film over the substrate, the second pixel electrode, the third pixel electrode, and the first sacrificial layer, forming the second sacrificial film over the second light-emitting film, and processing the second light-emitting film and the second sacrificial film to form a second light-emitting layer adjacent to the first light-emitting layer and a second sacrificial layer over the second light-emitting layer, and and forming a photoelectric conversion film on the first organic layer, a photoelectric conversion film on the second organic layer, a third sacrificial film on the photoelectric conversion film, and processing the photoelectric conversion film and the third sacrificial film to form a photoelectric conversion layer adjacent to the second light-emitting layer and a third sacrificial layer on the photoelectric conversion layer; forming a first organic layer between the second light-emitting layer and the photoelectric conversion layer; forming a second organic layer between the first light-emitting layer and the second light-emitting layer, the second organic layer having a transmittance for light of a specific wavelength, which is at least a part of the wavelengths of visible light, higher than the transmittance for light of the specific wavelength in the first organic layer; removing at least a part of the first to third sacrificial layers; and forming a common electrode that is translucent to visible light on the first light-emitting layer, the second light-emitting layer, the photoelectric conversion layer, the first organic layer, and the second organic layer.

[0021] Alternatively, one embodiment of the present invention includes forming a first pixel electrode, a second pixel electrode, and a third pixel electrode over a substrate that transmits visible light, forming a first light-emitting film over the substrate and the first to third pixel electrodes, forming a first sacrificial film over the first light-emitting film, and processing the first light-emitting film and the first sacrificial film to form a first light-emitting layer and the first sacrificial layer over the first light-emitting layer, forming a second light-emitting film over the substrate, the second pixel electrode, the third pixel electrode, and the first sacrificial layer, forming the second sacrificial film over the second light-emitting film, and processing the second light-emitting film and the second sacrificial film to form a second light-emitting layer adjacent to the first light-emitting layer and the second sacrificial layer over the second light-emitting layer, and forming a second light-emitting film over the substrate, the third pixel electrode, and the first light-emitting layer. a first organic layer between the second light-emitting layer and the photoelectric conversion layer; a second organic layer between the first light-emitting layer and the second light-emitting layer, the second organic layer having a transmittance of at least one color of light selected from red, green, and blue that is higher than the transmittance of the first organic layer; at least a part of the first to third sacrificial layers is removed; and a common electrode having a transparency to visible light is formed on the first light-emitting layer, the second light-emitting layer, the photoelectric conversion layer, the first organic layer, and the second organic layer.

[0022] Alternatively, in the above aspect, the first and second pixel electrodes may be transparent to visible light.

[0023] Alternatively, in the above embodiment, before forming the second organic layer, a protective film may be formed on the first to third sacrificial layers and on the first organic layer, an organic film may be formed on the protective film, and the organic film may be processed to form the second organic layer.

[0024] Alternatively, in the above embodiment, the protective layer below the second organic layer may be formed by processing the protective film.

[0025] Alternatively, in the above embodiment, after removing at least a portion of the first to third sacrificial layers, a common layer may be formed on the first light-emitting layer, the second light-emitting layer, the photoelectric conversion layer, the first organic layer, and the second organic layer, and a common electrode may be formed on the common layer.

[0026] Alternatively, in the above embodiment, the common layer may include a carrier injection layer.

[0027] Alternatively, in the above-described embodiment, after forming the first light-emitting film and the first sacrificial film, a film functioning as a first carrier transport layer is formed on the first light-emitting film, and the first light-emitting film, the film functioning as the first carrier transport layer, and the first sacrificial film are processed to form a first light-emitting layer, a first carrier transport layer on the first light-emitting layer, and a first sacrificial layer on the first carrier transport layer; after forming the second light-emitting film and the second sacrificial film, a film functioning as a second carrier transport layer is formed on the second light-emitting film, and the second light-emitting film, the second carrier transport layer, and the first sacrificial film are processed to form a second light-emitting layer, a first carrier transport layer on the first light-emitting layer, and a first sacrificial layer on the first sacrificial film. By processing the film that functions as a rear transport layer and the second sacrificial film, a second light-emitting layer, a second carrier transport layer on the second light-emitting layer, and a second sacrificial layer on the second carrier transport layer may be formed; after forming the photoelectric conversion film and after forming the third sacrificial film, a film that functions as a third carrier transport layer may be formed on the photoelectric conversion film; and by processing the photoelectric conversion film, the film that functions as the third carrier transport layer, and the third sacrificial film, a photoelectric conversion layer, a third carrier transport layer on the photoelectric conversion layer, and a third sacrificial layer on the third carrier transport layer may be formed.

[0028] Alternatively, in the above embodiment, the first to third pixel electrodes may be formed so as to have tapered ends, and the first light-emitting film may be processed to form a first light-emitting layer so as to cover the ends of the first pixel electrode, the second light-emitting film may be processed to form a second light-emitting layer so as to cover the ends of the second pixel electrode, and the photoelectric conversion film may be processed to form a photoelectric conversion layer so as to cover the ends of the third pixel electrode.

[0029] Alternatively, in the above aspect, the first light-emitting layer may be formed by processing the first light-emitting film so as to have a first tapered portion between an end of the first pixel electrode and an end of the first sacrificial layer, the second light-emitting layer may be formed by processing the second light-emitting film so as to have a second tapered portion between an end of the second pixel electrode and an end of the second sacrificial layer, and the photoelectric conversion layer may be formed by processing the photoelectric conversion film so as to have a third tapered portion between an end of the third pixel electrode and an end of the third sacrificial layer.

[0030] According to one embodiment of the present invention, a display device or an imaging device capable of imaging with high sensitivity can be provided. According to another embodiment of the present invention, a high-resolution display device or an imaging device can be provided. According to another embodiment of the present invention, a display device or an imaging device with a high aperture ratio can be provided. According to another embodiment of the present invention, a display device that allows a user to view a view behind the display device can be provided. According to another embodiment of the present invention, a display device with high light extraction efficiency can be provided. According to another embodiment of the present invention, a display device with high display quality can be provided. According to another embodiment of the present invention, a display device that can acquire biometric information such as a fingerprint can be provided. According to another embodiment of the present invention, a display device that functions as a touch sensor can be provided. According to another embodiment of the present invention, a highly functional display device can be provided. According to another embodiment of the present invention, a highly reliable display device or an imaging device can be provided. According to another embodiment of the present invention, a display device or an imaging device having a novel structure can be provided. According to another embodiment of the present invention, an electronic device including the display device or the imaging device can be provided. According to another embodiment of the present invention, a manufacturing method of the display device, the imaging device, or the electronic device can be provided.

[0031] Note that the description of these effects does not preclude the existence of other effects. Note that one embodiment of the present invention does not necessarily have all of these effects. Note that effects other than these can be extracted from the description in the specification, drawings, claims, etc.

[0032] FIG. 1A is a top view showing a structural example of a display device. FIGS. 1B, 1C1, and 1C2 are cross-sectional views showing a structural example of a display device. FIG. 2 is a cross-sectional view showing a structural example of a display device. FIGS. 3A and 3B are cross-sectional views showing a structural example of a display device. FIGS. 4A and 4B are cross-sectional views showing a structural example of a display device. FIGS. 5A, 5B1, and 5B2 are cross-sectional views showing a structural example of a display device. FIGS. 6A to 6E are cross-sectional views showing an example of a manufacturing method of a display device. FIGS. 7A to 7C are cross-sectional views showing an example of a manufacturing method of a display device. FIGS. 8A to 8C are cross-sectional views showing an example of a manufacturing method of a display device. FIGS. 9A to 9D are cross-sectional views showing an example of a manufacturing method of a display device. FIGS. 10A to 10D are cross-sectional views showing an example of a manufacturing method of a display device. FIGS. 11A and 11B are cross-sectional views showing an example of a manufacturing method of a display device. FIGS. 12A to 12D are cross-sectional views showing an example of a manufacturing method of a display device. FIGS. 13A to 13C are cross-sectional views showing an example of a manufacturing method of a display device. 14A and 14B are cross-sectional views illustrating an example of a method for manufacturing a display device. FIG. 15 is a perspective view illustrating a structural example of a display device. FIG. 16A is a cross-sectional view illustrating a structural example of a display device. FIGS. 16B1 and 16B2 are cross-sectional views illustrating structural examples of a transistor. FIG. 17 is a cross-sectional view illustrating a structural example of a display device. FIG. 18 is a cross-sectional view illustrating a structural example of a display device. FIG. 19 is a cross-sectional view illustrating a structural example of a display device. FIGS. 20A to 20D are cross-sectional views illustrating a structural example of a display device. FIG. 21 is a perspective view illustrating a structural example of a display device. FIG. 22 is a cross-sectional view illustrating a structural example of a display device. FIG. 23 is a cross-sectional view illustrating a structural example of a display device. FIG. 24 is a cross-sectional view illustrating a structural example of a display device. FIG. 25 is a cross-sectional view illustrating a structural example of a display device. FIGS. 26A and 26B are top views illustrating a structural example of a display panel. FIGS. 27A to 27C are top views illustrating a structural example of a display panel. FIGS. 28A and 28B are cross-sectional views illustrating a structural example of a display panel. FIGS. 29A, 29B, and 29D are cross-sectional views illustrating examples of display devices. 29C and 29E are diagrams showing examples of images, 29F to 29H are top views showing examples of pixels, and Fig. 30A is a cross-sectional view showing an example of the configuration of a display device.30B to 30D are top views showing examples of pixels. FIG. 31A is a cross-sectional view showing a configuration example of a display device. FIGS. 31B to 31I are top views showing an example of a pixel. FIGS. 32A and 32B are diagrams showing a configuration example of a display device. FIGS. 33A to 33G are diagrams showing a configuration example of a display device. FIGS. 34A to 34F are diagrams showing examples of pixels. FIGS. 34G and 34H are diagrams showing example circuit diagrams of pixels. FIGS. 35A to 35J are diagrams showing a configuration example of a display device. FIGS. 36A and 36B are diagrams showing an application example of a display device. FIG. 37 is a diagram showing an application example of a display device. FIG. 38 is a diagram showing an application example of a display device.

[0033] Hereinafter, embodiments will be described with reference to the drawings. However, it will be readily understood by those skilled in the art that the embodiments can be implemented in many different ways and that various changes in form and details can be made without departing from the spirit and scope of the present invention. Therefore, the present invention should not be interpreted as being limited to the following description of the embodiments.

[0034] In the configuration of the invention described below, the same parts or parts having similar functions are denoted by the same reference numerals in different drawings, and repeated explanations thereof will be omitted. In addition, when referring to similar functions, the same hatch pattern may be used and no particular reference numeral may be assigned.

[0035] In the drawings described in this specification, the size of each component, the thickness of a layer, or an area may be exaggerated for clarity, and therefore, the drawings are not necessarily limited to the scale.

[0036] In this specification, ordinal numbers such as "first" and "second" are used to avoid confusion of components and do not limit the number.

[0037] In the following description, the terms "up" and "down" and other directions are generally used in accordance with the directions in the drawings. However, for ease of explanation, the directions indicated by "up" or "down" in the specification may not match those in the drawings. For example, when describing the stacking order (or formation order) of a laminate, even if the surface on which the laminate is provided (such as the surface to be formed, the supporting surface, the adhesive surface, or the flat surface) is located above the laminate in the drawing, the direction may be expressed as "down" and the opposite direction as "up."

[0038] Furthermore, in this specification and the like, the terms "film" and "layer" can be interchangeable in some cases or depending on the situation. For example, the terms "conductive layer" and "insulating layer" can sometimes be interchangeable with the terms "conductive film" and "insulating film."

[0039] In this specification, the term "EL layer" refers to a layer provided between a pair of electrodes of a light-emitting element and containing at least a light-emitting substance (also referred to as a light-emitting layer), or a laminate including the light-emitting layer, and the term "PD layer" refers to a layer provided between a pair of electrodes of a light-receiving element and containing at least a photoelectric conversion material (also referred to as an active layer or a photoelectric conversion layer), or a laminate including the active layer.

[0040] In this specification and the like, a display panel, which is one aspect of a display device, has a function of displaying (outputting), for example, an image on a display surface, and therefore the display panel is one aspect of an output device.

[0041] In addition, in this specification, a display panel having a connector such as an FPC (Flexible Printed Circuit) or a TCP (Tape Carrier Package) attached to its substrate, or a substrate having an IC mounted thereon using a COG (Chip On Glass) method or the like, may be referred to as a display panel module, a display module, or simply a display panel, etc.

[0042] Embodiment 1 In this embodiment, a structural example of a display device according to one embodiment of the present invention and an example of a manufacturing method of the display device will be described.

[0043] One embodiment of the present invention is a display device in which 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) are provided over a substrate. The light-emitting element has a pair of electrodes and an EL layer therebetween. The light-receiving element has a pair of electrodes and a PD layer therebetween. Here, the EL layer has at least a light-emitting layer and preferably has multiple layers. The EL layer preferably has, for example, a light-emitting layer and a carrier transport layer (hole transport layer or electron transport layer) over the light-emitting layer. The PD layer has at least an active layer (also referred to as a photoelectric conversion layer) and preferably has multiple layers. The PD layer preferably has, for example, an active layer and a carrier transport layer (hole transport layer or electron transport layer) over the active layer.

[0044] The light-emitting element is preferably an organic EL element (organic electroluminescent element), and the light-receiving element is preferably an organic photodiode (organic photoelectric conversion element).

[0045] Furthermore, the display device preferably has two or more light-emitting elements that emit different colors. The light-emitting elements that emit different colors have EL layers containing different materials. For example, a full-color display device can be realized by having three types of light-emitting elements that emit red (R), green (G), and blue (B) light, respectively.

[0046] One embodiment of the present invention functions as an imaging device because it can capture an image using a plurality of light-receiving elements. In this case, the light-emitting elements can be used as a light source for capturing an image. Another embodiment of the present invention functions as a display device because it can display an image using a plurality of light-emitting elements. Therefore, one embodiment of the present invention can be said to be a display device having an imaging function or an imaging device having a display function.

[0047] For example, in a display device of one embodiment of the present invention, not only light-emitting elements but also light-receiving elements are arranged in a matrix in the display portion. Therefore, the display portion has a function as a light-receiving portion in addition to a function of displaying an image. Since an image can be captured by the plurality of light-receiving elements provided in the display portion, the display device can function as an image sensor or a touch sensor. That is, the display device of one embodiment of the present invention can capture an image in the display portion, for example. Alternatively, the display device of one embodiment of the present invention can detect that an object is approaching or touching the display portion. Furthermore, since the light-emitting elements provided in the display portion can be used as a light source for receiving light, there is no need to provide a light source separately from the display device. Therefore, a highly functional display device can be realized without increasing the number of electronic components.

[0048] In this specification, the term "touch sensor" may include a "non-contact touch sensor" that has the function of detecting an object that is in proximity but not in contact with the object.

[0049] In one embodiment of the present invention, when light emitted from a light-emitting element included in a display portion is reflected by an object, a light-receiving element can detect the reflected light; therefore, imaging can be performed even in a dark environment, and touch of the object can be detected.

[0050] Furthermore, the display device of one embodiment of the present invention can capture an image of a fingerprint or palm print when a finger, palm, or the like is placed in contact with the display unit. Therefore, an electronic device having the display device of one embodiment of the present invention can perform biometric authentication using the captured image of a fingerprint or palm print. This eliminates the need for a separate imaging device for fingerprint or palm print authentication, thereby reducing the number of components in the electronic device. Furthermore, since the light-receiving elements are arranged in a matrix on the display unit, fingerprints or palm prints can be captured anywhere on the display unit, thereby achieving an electronic device with excellent convenience.

[0051] Here, it is known that when forming separate EL layers for light-emitting elements of different colors or when forming PD layers, they are formed by a vapor deposition method using a shadow mask such as a metal mask. However, this method makes it difficult to achieve high resolution and a high aperture ratio because the shape and position of the island-shaped organic film can deviate from the design due to various factors such as the accuracy of the metal mask, misalignment between the metal mask and the substrate, deflection of the metal mask, and, for example, the spread of the contours of the deposited film due to vapor scattering. Furthermore, during vapor deposition, debris may be generated due to material adhering to the metal mask. Such debris may cause pattern defects in the light-emitting elements. Furthermore, the debris may cause short circuits. Furthermore, a process of cleaning the material adhering to the metal mask is required. Therefore, measures have been taken to artificially increase the resolution (also known as pixel density) by applying special pixel arrangement methods such as a pentile arrangement.

[0052] In one embodiment of the present invention, an EL layer and a PD layer are processed into a fine pattern without using a shadow mask such as a metal mask. This makes it possible to realize a display device with high functionality, high definition, and a large aperture ratio. Furthermore, because the EL layer can be individually formed, a display device with extremely vivid, high contrast, and high display quality can be realized.

[0053] When the EL layer and the PD layer are separately formed, spaces are formed between adjacent EL layers and between adjacent EL and PD layers. For example, when a common electrode is formed on the EL layer and the PD layer, the common electrode may enter the spaces, causing discontinuities in the common electrode. Furthermore, the common electrode may become locally thin in the spaces, increasing electrical resistance. Therefore, by filling the spaces with an insulating layer, the occurrence of the above defects can be suppressed, resulting in a highly reliable display device.

[0054] Here, for example, if the substrate provided in the display device is a substrate that is transmissive to visible light and an insulating layer that is highly transmissive to visible light is provided in the space, external light can pass through the insulating layer. Furthermore, if the pair of electrodes of the light-emitting element are electrodes that are transmissive to visible light, external light can pass through the light-emitting element. As a result, a user of the display device can view the scenery behind the display device as a real image.

[0055] In this specification and the like, when A is said to be translucent to light B, it means that the transmittance of light B through A is 5% or more.

[0056] On the other hand, if an insulating layer that is highly translucent to visible light is provided in the above space, some of the light emitted by the EL layer may be incident on the PD layer due to stray light, which may cause noise when capturing an image using a light-receiving element having a PD layer, resulting in reduced imaging sensitivity.

[0057] Therefore, in a display device according to one embodiment of the present invention, an insulating layer that is highly light-transmitting to visible light is provided in the space between the EL layers, and an insulating layer that is highly light-blocking to visible light is provided in the space between the EL layers and the PD layers, thereby enabling a user of the display device to view a scene behind the display device as a real image and suppressing a decrease in imaging sensitivity due to stray light.

[0058] The insulating layer provided in the space can be, for example, an organic layer, such as a resin. For example, the insulating layer provided in the space between the EL layers can be a photosensitive resin such as photoresist. Furthermore, the insulating layer provided in the space between the EL layer and the PD layer can be a colored layer (also called a color filter), such as a color resist (also called a photosensitive resist for color filters). For example, by using a photoresist as the insulating layer provided in the space between the EL layers and a color resist as the insulating layer provided in the space between the EL layer and the PD layer, the insulating layer can be formed in the space by simply applying the photoresist or color resist and then performing exposure and development processes.

[0059] [Configuration Example 1] Fig. 1A shows a schematic top view of a display device 100. The display device 100 has a plurality of light-emitting elements 130R that exhibit red light, a plurality of light-emitting elements 130G that exhibit green light, a plurality of light-emitting elements 130B that exhibit blue light, and a plurality of light-receiving elements 150. In Fig. 1A, in order to easily distinguish between the light-emitting elements, the light-emitting region of each light-emitting element is labeled with the letter R, G, or B. Also, in Fig. 1A, the light-receiving region of the light-receiving element is labeled with the letter S.

[0060] In this specification and the like, when describing matters common to, for example, the light emitting element 130R, the light emitting element 130G, and the light emitting element 130B, they may be referred to as the light emitting element 130. When describing matters common to other components distinguished by alphabets, they may also be described using symbols without the alphabets.

[0061] The light-emitting elements 130R, 130G, 130B, and the light-receiving elements 150 are arranged in a matrix. Fig. 1A shows a configuration in which two elements are alternately arranged in one direction. The arrangement of the light-emitting elements and the light-receiving elements is not limited to this, and other arrangements such as a stripe arrangement, an S-stripe arrangement, a delta arrangement, a Bayer arrangement, or a zigzag arrangement may also be used. Alternatively, a pentile arrangement or a diamond arrangement may also be used.

[0062] As the light-emitting element 130R, the light-emitting element 130G, and the light-emitting element 130B, it is preferable to use an EL element such as an OLED (organic light-emitting diode) or a QLED (quantum-dot light-emitting diode). Examples of light-emitting materials that the EL elements have include fluorescent materials, phosphorescent materials, inorganic compounds (e.g., quantum dot materials), and materials that exhibit thermally activated delayed fluorescence (thermally activated delayed fluorescence: TADF materials).

[0063] The light receiving element 150 may be, for example, a pn-type or pin-type photodiode (also referred to as a photodiode, PD). The light receiving element 150 functions as a photoelectric conversion element that detects light incident on the light receiving element 150 and generates an electric charge. The amount of electric charge generated by the photoelectric conversion element is determined according to the amount of incident light. In particular, it is preferable to use an organic photodiode having a layer containing an organic compound as the light receiving element 150. Organic photodiodes can be easily made thin, lightweight, and large in area, and have a high degree of freedom in shape and design, making them applicable to a variety of devices.

[0064] The display device 100 includes the light receiving element 150, which allows the display device 100 to capture an image. Therefore, the display device 100 can function as an image sensor or a touch sensor. That is, the display device 100 can capture an image, for example, on the display unit. Alternatively, the display device 100 can detect that an object is approaching the display unit or that an object is touching the display unit. Furthermore, since the light emitting element 130 can be used as a light source for receiving light, there is no need to provide a light source separate from the display device 100. Therefore, the display device 100 can be a highly functional display device without increasing the number of electronic components.

[0065] In the display device 100, when the light emitted from the light emitting element 130 is reflected by an object, the light receiving element 150 can detect the reflected light. Therefore, the display device 100 can capture images even in a dark environment and can detect touch (including non-touch) of an object.

[0066] Furthermore, the display device 100 can capture an image of a fingerprint or palm print when a finger, palm, or the like is placed in contact with the display unit. Therefore, an electronic device having the display device 100 can perform biometric authentication using the captured image of the fingerprint or palm print. This eliminates the need to provide a separate imaging device for fingerprint authentication or palm print authentication, thereby reducing the number of components in the electronic device. Furthermore, since the light receiving elements 150 are arranged in a matrix on the display unit, fingerprints or palm prints can be captured anywhere on the display unit. Therefore, an electronic device having the display device 100 can be an electronic device with excellent convenience.

[0067] FIG. 1A shows a common electrode 115 that the light emitting element 130R, the light emitting element 130G, the light emitting element 130B, and the light receiving element 150 have, and a connection electrode 113 that is electrically connected to the common electrode 115.

[0068] The connection electrode 113 is given a potential to be supplied to the common electrode 115. The connection electrode 113 is provided outside the display section where the light emitting elements 130 and the light receiving elements 150 are arranged.

[0069] The connection electrodes 113 can be provided along the outer periphery of the display unit. For example, they may be provided along one side of the outer periphery of the display unit, or they may be provided over two or more sides of the outer periphery of the display unit. That is, when the top surface of the display unit has a rectangular shape, the top surface of the connection electrodes 113 can have a strip-like, L-shaped, U-shaped (square bracket-shaped), frame-like, or the like shape.

[0070] Fig. 1B is a schematic cross-sectional view corresponding to the dashed line A1-A2 in Fig. 1A. Fig. 1B shows a substrate 101, an insulating layer 103 on the substrate 101, and light-emitting elements 130R, 130G, and 130B, and a light-receiving element 150 on the insulating layer 103.

[0071] The substrate 101 may be a substrate that is transparent to visible light, such as a glass substrate, a quartz substrate, a sapphire substrate, or a plastic substrate.

[0072] The insulating layer 103 can function as an interlayer insulating layer. For example, although not shown in FIG. 1B , a layer including, for example, a transistor can be provided over the substrate 101, and the insulating layer 103 can be provided to cover the layer. The insulating layer 103 is preferably planarized, but does not have to be planarized.

[0073] 1B , the insulating layer 103 may have a recess between adjacent light-emitting elements 130. The insulating layer 103 may also have a recess between adjacent light-emitting elements 130 and light-receiving elements 150. Note that the insulating layer 103 may not have a recess between adjacent light-emitting elements 130 or between adjacent light-emitting elements 130 and light-receiving elements 150.

[0074] The light-emitting element 130R has a pixel electrode 111R, an EL layer 112R on the pixel electrode 111R, a common layer 114 on the EL layer 112R, and a common electrode 115 on the common layer 114. The light-emitting element 130G has a pixel electrode 111G, an EL layer 112G on the pixel electrode 111G, a common layer 114 on the EL layer 112G, and a common electrode 115 on the common layer 114. The light-emitting element 130B has a pixel electrode 111B, an EL layer 112B on the pixel electrode 111B, a common layer 114 on the EL layer 112B, and a common electrode 115 on the common layer 114. The light receiving element 150 has a conductive layer 131, a pixel electrode 111S on the conductive layer 131, a PD layer 155 on the pixel electrode 111S, a common layer 114 on the PD layer 155, and a common electrode 115 on the common layer 114. The pixel electrode 111 may be referred to as a lower electrode, and the common electrode 115 may be referred to as an upper electrode.

[0075] The EL layer 112R of the light-emitting element 130R contains a light-emitting organic compound that emits light having an intensity at least in the red wavelength range (e.g., wavelengths of 590 nm or more and less than 830 nm). The EL layer 112G of the light-emitting element 130G contains a light-emitting organic compound that emits light having an intensity at least in the green wavelength range (e.g., wavelengths of 490 nm or more and less than 590 nm). The EL layer 112B of the light-emitting element 130B contains a light-emitting organic compound that emits light having an intensity at least in the blue wavelength range (e.g., wavelengths of 360 nm or more and less than 490 nm). The layer containing the light-emitting organic compound included in the EL layer 112 can be referred to as a light-emitting layer. Note that the display device 100 may also include an EL layer 112 that emits light having an intensity in the infrared wavelength range, for example, the near-infrared wavelength range (e.g., wavelengths of 830 nm or more and less than 2500 nm).

[0076] The EL layer 112 preferably has a carrier transport layer on the light-emitting layer. This prevents the light-emitting layer from being exposed to the outermost surface during the manufacturing process of the display device 100, thereby reducing damage to the light-emitting layer. As a result, the reliability of the display device 100 can be improved.

[0077] Furthermore, the EL layer 112 may have one or more of a hole injection layer, a hole transport layer, a hole blocking layer, an electron blocking layer, an electron transport layer, and an electron injection layer. For example, the EL layer 112 may have a structure in which a hole injection layer, a hole transport layer, a light-emitting layer, and an electron transport layer are stacked in this order from the pixel electrode 111 side. Alternatively, the EL layer 112 may have a structure in which an electron injection layer, an electron transport layer, a light-emitting layer, and a hole transport layer are stacked in this order from the pixel electrode 111 side.

[0078] In this specification and the like, visible light refers to light having a wavelength of, for example, 360 nm or more and less than 830 nm, and infrared light refers to light having a wavelength of, for example, 830 nm or more.

[0079] In addition, in this specification and the like, holes or electrons may be referred to as "carriers." Specifically, a hole injection layer or an electron injection layer may be referred to as a "carrier injection layer," a hole transport layer or an electron transport layer may be referred to as a "carrier transport layer," and a hole block layer or an electron block layer may be referred to as a "carrier block layer." Note that the above-mentioned carrier injection layer, carrier transport layer, and carrier block layer may not be clearly distinguishable from each other depending on their cross-sectional shapes, properties, etc. Furthermore, one layer may have two or three functions of the carrier injection layer, carrier transport layer, and carrier block layer.

[0080] The PD layer 155 of the light receiving element 150 contains a photoelectric conversion material that is sensitive to visible light or infrared light. The wavelength range to which the photoelectric conversion material of the PD layer 155 is sensitive preferably includes one or more of the wavelength range of light emitted by the light emitting element 130R, the wavelength range of light emitted by the light emitting element 130G, and the wavelength range of light emitted by the light emitting element 130B. Alternatively, a photoelectric conversion material that is sensitive to infrared light with a longer wavelength than the wavelength range of light emitted by the light emitting element 130R may be used. The layer containing the photoelectric conversion material included in the PD layer 155 can be referred to as an active layer or a photoelectric conversion layer.

[0081] Furthermore, the PD layer 155 preferably has a carrier transport layer on the active layer. This prevents the active layer from being exposed on the outermost surface during the manufacturing process of the display device 100, thereby reducing damage to the active layer. This improves the reliability of the display device 100.

[0082] Furthermore, the PD layer 155 may have one or more of a hole transport layer, a hole blocking layer, an electron blocking layer, and an electron transport layer. For example, the PD layer 155 may have a configuration in which a hole transport layer, an active layer, and an electron transport layer are stacked in this order from the pixel electrode 111 side. Alternatively, the EL layer 112 may have a configuration in which an electron transport layer, an active layer, and a hole transport layer are stacked in this order from the pixel electrode 111 side.

[0083] The common layer 114 can be an electron injection layer or a hole injection layer. When the common layer 114 has an electron injection layer, the EL layer 112 does not need to have an electron injection layer, and when the common layer 114 has a hole injection layer, the EL layer 112 does not need to have a hole injection layer. Here, it is preferable to use a material with as low an electrical resistance as possible for the common layer 114. Alternatively, it is preferable to form the common layer 114 as thin as possible, since this can reduce the electrical resistance in the thickness direction of the common layer 114. For example, the thickness of the common layer 114 is preferably 1 nm to 5 nm, and more preferably 1 nm to 3 nm.

[0084] The common layer 114 may have a hole transport layer, a hole blocking layer, an electron blocking layer, or an electron transport layer. As described above, the common layer 114 can have at least one of a hole injection layer, a hole transport layer, a hole blocking layer, an electron blocking layer, an electron transport layer, or an electron injection layer. The layers included in the common layer 114 can be configured not to be included in the EL layer 112 and the PD layer 155.

[0085] Here, the function of the common layer 114 in the light-emitting element 130 may differ from the function of the common layer 114 in the light-receiving element 150. For example, the common layer 114 may function as an electron injection layer or a hole injection layer in the light-emitting element 130, and may function as an electron transport layer or a hole transport layer in the light-receiving element 150.

[0086] The conductive layer 131 can be a conductive layer that is reflective to visible light, and can be made of, for example, a metal material. For example, the conductive layer 131 can be made of a metal material such as gold, silver, platinum, magnesium, nickel, tungsten, chromium, molybdenum, iron, cobalt, copper, palladium, or titanium, or an alloy material containing such a metal material (for example, an alloy of silver and magnesium). Alternatively, the conductive layer 131 can be made of a nitride of such a metal material (for example, titanium nitride).

[0087] The pixel electrode 111 and the common electrode 115 can be conductive layers that transmit visible light. For example, conductive oxides such as indium oxide, indium tin oxide, indium zinc oxide, zinc oxide, or zinc oxide containing gallium, or graphene can be used for the pixel electrode 111 and the common electrode 115. Alternatively, metal materials such as gold, silver, platinum, magnesium, nickel, tungsten, chromium, molybdenum, iron, cobalt, copper, palladium, and titanium, or alloy materials containing such metal materials can be used for the pixel electrode 111 and the common electrode 115. Alternatively, nitrides of such metal materials (e.g., titanium nitride) can be used for the pixel electrode 111 and the common electrode 115. Note that when a metal material or an alloy material (or a nitride thereof) is used, it is preferable to make the thickness thereof thin enough to have light-transmitting properties. A stacked film of the above materials can also be used as the conductive layer. For example, it is preferable to use a stacked film of an alloy of silver and magnesium and indium tin oxide for the pixel electrode 111 and the common electrode 115 because the conductivity of the pixel electrode 111 and the common electrode 115 can be increased.

[0088] A protective layer 146 is provided on the EL layer 112 and the PD layer 155. For example, the protective layer 146 is provided in regions of the EL layer 112 and the PD layer 155 that are not in contact with the common layer 114.

[0089] An insulating layer 125 and an insulating layer 126 are provided between adjacent light-emitting elements 130 and light-receiving elements 150. For example, an insulating layer 125 and an insulating layer 126 are provided between adjacent EL layers 112 and PD layers 155. Furthermore, an insulating layer 125 and an insulating layer 127 are provided between two adjacent light-emitting elements 130. For example, an insulating layer 125 and an insulating layer 127 are provided between two adjacent EL layers 112.

[0090] Specifically, the insulating layer 125 is provided, for example, on the side surfaces of the EL layer 112, the side surfaces of the PD layer 155, the side surfaces of the protective layer 146, the top surface of the protective layer 146, and the top surface of the insulating layer 103. By providing the insulating layer 125, it is possible to prevent impurities such as water from entering the interior from the side surfaces of the EL layer 112 and the PD layer 155.

[0091] Furthermore, the insulating layer 126 is provided on the insulating layer 125 and can fill the space between the adjacent EL layer 112 and PD layer 155. Furthermore, the insulating layer 127 is provided on the insulating layer 125 and can fill the space between two adjacent EL layers 112. The common layer 114 and the common electrode 115 are provided on the insulating layer 126 and the insulating layer 127.

[0092] By providing the insulating layers 126 and 127, it is possible to prevent the occurrence of step discontinuities in the common electrode 115 in the spaces between adjacent EL layers 112 and PD layers 155, and in the spaces between two adjacent EL layers 112, thereby preventing connection defects. It is also possible to prevent the common electrode 115 from becoming locally thin due to steps, which would otherwise cause an increase in electrical resistance. As a result, the display device 100 can be made a highly reliable display device.

[0093] The protective layer 146 and the insulating layer 125 can include an inorganic material. For the protective layer 146 and the insulating layer 125, for example, an inorganic insulating film such as an insulating oxide film, a nitride insulating film, an oxynitride insulating film, or a nitride oxide insulating film can be used. The protective layer 146 and the insulating layer 125 may have a single-layer structure or a stacked-layer structure. Examples of oxide insulating films include a silicon oxide film, an aluminum oxide film, a magnesium oxide film, an indium gallium zinc oxide film, a gallium oxide film, a germanium oxide film, an yttrium oxide film, a zirconium oxide film, a lanthanum oxide film, a neodymium oxide film, a hafnium oxide film, and a tantalum oxide film. Examples of nitride insulating films include a silicon nitride film and an aluminum nitride film. Examples of oxynitride insulating films include a silicon oxynitride film and an aluminum oxynitride film. Examples of nitride oxide insulating films include a silicon nitride oxide film and an aluminum nitride oxide film. In particular, by using an inorganic insulating film such as an aluminum oxide film, a hafnium oxide film, or a silicon oxide film formed by an atomic layer deposition (ALD) method as the protective layer 146 and the insulating layer 125, the protective layer 146 and the insulating layer 125 can be formed with few pinholes and with an excellent function of protecting the EL layer 112.

[0094] In this specification and the like, an oxynitride refers to a material whose composition contains more oxygen than nitrogen, and a nitride oxide refers to a material whose composition contains more nitrogen than oxygen. For example, silicon oxynitride refers to a material whose composition contains more oxygen than nitrogen, and silicon nitride oxide refers to a material whose composition contains more nitrogen than oxygen.

[0095] The protective layer 146 and the insulating layer 125 can be formed by a sputtering method, a chemical vapor deposition (CVD) method, a pulsed laser deposition (PLD) method, an ALD method, or the like. The insulating layer 125 is preferably formed by an ALD method, which has good coverage.

[0096] Here, the insulating layer 126 is made of, for example, a material that has high light-blocking properties against visible light. This makes it possible to prevent a portion of the light emitted by the EL layer 112 adjacent to the PD layer 155 from being incident on the PD layer 155 due to stray light, compared to when, for example, a material that is highly translucent to visible light is used for the insulating layer 126. Therefore, the display device 100 can be a display device that can capture images with low noise and high imaging sensitivity. On the other hand, the insulating layer 127 can be made of, for example, a material that is highly translucent to visible light.

[0097] In one embodiment of the present invention, the insulating layer 126 has a lower transmittance for light of a specific wavelength, which is at least a portion of the wavelengths of visible light, than the insulating layer 127. For example, when the specific wavelength is 600 nm, the insulating layer 126 has a lower transmittance for light of a wavelength of 600 nm than the insulating layer 127. Furthermore, the insulating layer 126 can have a lower transmittance for light of at least one color selected from red (e.g., a wavelength of 590 nm or more and less than 830 nm), green (e.g., a wavelength of 490 nm or more and less than 590 nm), and blue (e.g., a wavelength of 360 nm or more and less than 490 nm) than the corresponding transmittance for light of the insulating layer 127. For example, the insulating layer 126 can have a lower transmittance for green light than the insulating layer 127. As described above, the insulating layer 126 can sometimes be referred to as a colored layer.

[0098] The wavelength of light for which the insulating layer 126 has a light-blocking property is preferably the same as the wavelength of light for which the PD layer 155 is sensitive. For example, if the PD layer is sensitive to light with a wavelength corresponding to green light, the insulating layer 126 preferably has a light-blocking property for light with a wavelength corresponding to green light. This makes it possible to suitably suppress a decrease in the imaging sensitivity of the display device 100 due to stray light.

[0099] The insulating layer 126 and the insulating layer 127 can contain an organic material. Therefore, the insulating layer 126 and the insulating layer 127 can be referred to as organic layers. For example, the insulating layer 126 and the insulating layer 127 can be made of a phenolic resin, an acrylic resin, a polyimide resin, an epoxy resin, an imide resin, a polyamide resin, a polyimideamide resin, a silicone resin, a siloxane resin, a benzocyclobutene-based resin, or precursors of these resins. For example, novolac resin, which is a type of phenolic resin, can be used for the insulating layer 126 and the insulating layer 127. When the insulating layer 126 contains a resin, the insulating layer 126 can be referred to as a resin layer, and when the insulating layer 127 contains a resin, the insulating layer 127 can be referred to as a resin layer.

[0100] Furthermore, a photosensitive resin can be used for the insulating layer 126 and the insulating layer 127. For example, a color resist can be used for the insulating layer 126, and a photoresist can be used for the insulating layer 127. In this case, the insulating layer 126 and the insulating layer 127 can be formed by a spin coating method, a spraying method, a screen printing method, a painting method, or the like.

[0101] In addition, a reflective film (e.g., a metal film containing one or more selected from silver, palladium, copper, titanium, aluminum, etc.) may be provided between the insulating layer 125 and the insulating layer 127, and the light emitted from the light-emitting layer may be reflected by the reflective film, thereby providing the function of improving the light extraction efficiency.

[0102] A protective layer 121 is provided on the common electrode 115 to cover the light emitting element 130 and the light receiving element 150. The protective layer 121 has a function of preventing impurities such as water from diffusing from above to the light emitting element 130 and the light receiving element 150.

[0103] The protective layer 121 may have, for example, a single-layer structure or a stacked-layer structure including at least an inorganic insulating film. Examples of the inorganic insulating film include oxide films or nitride films such as a silicon oxide film, a silicon oxynitride film, a silicon nitride oxide film, a silicon nitride film, an aluminum oxide film, an aluminum oxynitride film, and a hafnium oxide film. Alternatively, the protective layer 121 may be made of a semiconductor material such as indium gallium oxide or indium gallium zinc oxide.

[0104] The protective layer 121 may also be a laminated film of an inorganic insulating film and an organic insulating film. For example, a configuration in which an organic insulating film is sandwiched between a pair of inorganic insulating films is preferable. Furthermore, it is preferable that the organic insulating film functions as a planarizing film. This allows the upper surface of the organic insulating film to be flat, improving the coverage of the inorganic insulating film thereon and enhancing the barrier properties. Furthermore, since the upper surface of the protective layer 121 is flat, when a structure (e.g., a color filter, a touch sensor electrode, a lens array, etc.) is provided above the protective layer 121, the influence of uneven shapes caused by the structure below can be reduced, which is preferable.

[0105] Note that the insulating layer 103 can be formed using a material similar to that which can be used for the protective layer 121 .

[0106] FIG. 1C1 is a schematic cross-sectional view corresponding to the dashed dotted line B1-B2 in FIG. 1A, and shows a connection portion 140 where the connection electrode 113 and the common electrode 115 are electrically connected.

[0107] The connection portion 140 has a connection electrode 113 on the insulating layer 103, a common layer 114 on the connection electrode 113, a common electrode 115 on the common layer 114, and a protective layer 121 on the common electrode 115. A protective layer 146 is provided to cover the end of the connection electrode 113, and an insulating layer 125, an insulating layer 127, the common layer 114, the common electrode 115, and the protective layer 121 are stacked in this order on the protective layer 146. Note that the insulating layer 126 may be provided in place of the insulating layer 127 in the connection portion 140.

[0108] The connection electrode 113 and the common electrode 115 are electrically connected at the connection portion 140. The connection electrode 113 is electrically connected to, for example, an FPC (not shown). As described above, by supplying a power supply potential to, for example, the FPC, the power supply potential can be supplied to the common electrode 115 via the connection electrode 113.

[0109] The connection electrode 113 can be formed in the same process as the pixel electrode 111. For example, the pixel electrode 111 and the connection electrode 113 can be formed by forming a conductive film over the insulating layer 103 and the conductive layer 131 and processing the conductive film by, for example, an etching method. Therefore, the connection electrode 113 can have the same material as the pixel electrode 111. Note that the connection electrode 113 may have the same material as the conductive layer 131. In this case, the connection electrode 113 can be formed in the same process as the formation of the conductive layer 131.

[0110] Here, if the electrical resistance of the common layer 114 in the thickness direction is negligibly small, conduction between the connection electrode 113 and the common electrode 115 can be ensured even when the common layer 114 is provided between the connection electrode 113 and the common electrode 115. By providing the common layer 114 not only in the display portion but also in the connection portion 140, the common layer 114 can be formed without using a metal mask, including a mask for defining a film formation area (also called an area mask or a rough metal mask, to distinguish it from a fine metal mask). This simplifies the manufacturing process of the display device 100 and reduces the manufacturing cost of the display device 100. This allows the display device 100 to be a low-cost display device.

[0111] Fig. 1C2 is a modified example of the configuration shown in Fig. 1C1. Fig. 1C2 shows a configuration example in which the common layer 114 is not provided in the connection portion 140. In the example shown in Fig. 1C2, the connection electrode 113 and the common electrode 115 can be configured to be in contact with each other. This can reduce the electrical resistance between the connection electrode 113 and the common electrode 115.

[0112] Figure 2 is an enlarged view of region 133 shown in Figure 1B, showing insulating layer 126, insulating layer 127, and the surrounding areas.

[0113] FIG. 2 shows light 135, which is external light. As described above, the substrate 101, pixel electrode 111, insulating layer 127, and common electrode 115 are translucent to visible light. Therefore, light 135 can pass through the display device 100. This allows a user of the display device 100 to view the scenery behind the display device 100 (transmission image) as a real image through the display device 100. In addition, the user of the display device 100 can view an image displayed by the light-emitting element 130 superimposed on the transmission image of the display device 100. This allows the display device 100 to perform, for example, augmented reality (AR) display.

[0114] Furthermore, as described above, the display device 100 can suppress a decrease in imaging sensitivity due to stray light by using the insulating layer 126 provided between the EL layer 112 and the PD layer 155 as a layer with high light blocking properties against visible light.

[0115] As described above, the display device 100 is formed by separately fabricating the insulating layer 126 provided between adjacent EL layers 112 and PD layers 155, and the insulating layer 127 provided between two adjacent EL layers 112. Specifically, for example, the insulating layer 126 can be provided between adjacent EL layers 112 and PD layers 155 in the region on the insulating layer 125, and the insulating layer 127 can be provided in the other region. The insulating layer 126 is, for example, an insulating layer that has high light-blocking properties against visible light, and the insulating layer 127 is, for example, an insulating layer that has high light-transmitting properties against visible light. As described above, the display device 100 can suppress a decrease in imaging sensitivity due to stray light while allowing a user of the display device 100 to view the scenery behind the display device 100 (transmitted image) as a real image.

[0116] Note that by using an insulating layer 127 that has a high light-transmitting property to visible light, for example, it is possible to suppress, for example, light emitted from the EL layer 112 from being absorbed by the insulating layer 127. Thus, the display device 100 can have high light extraction efficiency.

[0117] In the display device 100, the substrate 101 and pixel electrode 111 provided below the EL layer 112 and the common electrode 115 provided on the EL layer 112 can all be transparent to visible light. Therefore, light 136 emitted from the EL layer 112 is emitted to both the substrate 101 side and the protective layer 121 side. Therefore, the display device 100 can be a dual-emission display device. Note that in FIG. 2, light 136 is represented by light 136G emitted from the EL layer 112G and light 136B emitted from the EL layer 112B.

[0118] 2 shows light 137 incident on the PD layer 155. The light receiving element 150 can detect the light 137. Here, by providing the conductive layer 131 that is reflective to visible light so as to have an area overlapping with the pixel electrode 111S and the PD layer 155, it is possible to prevent the light 135 incident on the substrate 101 side from entering the PD layer 155 via the pixel electrode 111S. Therefore, it is possible to suitably prevent a decrease in the imaging sensitivity of the display device 100 due to the light 135.

[0119] As shown in FIG. 2, it is preferable that the edge of the pixel electrode 111 has a tapered shape because foreign matter (for example, dust or particles) during the manufacturing process can be suitably removed by, for example, cleaning.

[0120] In this specification, the term "tapered shape" refers to a shape in which at least a part of the side surface of the structure is inclined with respect to the substrate surface. For example, it is preferable that the structure has a region in which the angle between the inclined side surface and the substrate surface (also referred to as the taper angle) is less than 90°.

[0121] The EL layer 112 and the PD layer 155 can be provided so as to cover the end of the pixel electrode 111. FIG. 2 shows an example in which the EL layer 112G covers the end of the pixel electrode 111G, the EL layer 112B covers the end of the pixel electrode 111B, and the PD layer 155 covers the end of the pixel electrode 111S. If the end of the pixel electrode 111 has a tapered shape, the EL layer 112 and the PD layer 155 can have a tapered portion 116 in a cross-sectional view. FIG. 2 shows an example in which the EL layer 112G has a tapered portion 116G between the end of the pixel electrode 111G and the insulating layer 127. FIG. 2 also shows an example in which the EL layer 112B has a tapered portion 116B1 between the left end of the pixel electrode 111B and the insulating layer 127, and a tapered portion 116B2 between the right end of the pixel electrode 111B and the insulating layer 126. Furthermore, FIG. 2 shows an example in which the PD layer 155 has a tapered portion 116S between the end of the pixel electrode 111S and the insulating layer 126.

[0122] The tapered portion 116 of the EL layer 112 and the PD layer 155 can improve the coverage of the EL layer 112 and the PD layer 155 with respect to the pixel electrode 111. This can prevent the EL layer 112 and the PD layer 155 from being broken and being locally thinned. This makes it possible to make the display device 100 a highly reliable display device.

[0123] 2 shows an example in which the pixel electrode 111S covers the end of the conductive layer 131. It is to be noted that the pixel electrode 111S does not have to cover the end of the conductive layer 131. In this case, for example, the end of the conductive layer 131 can be configured to be in contact with the PD layer 155.

[0124] 2 shows an example in which the lower surface of the insulating layer 125 is located below the lower surfaces of the EL layer 112 and the PD layer 155, and the lower surfaces of the EL layer 112 and the PD layer 155 are located below the lower surfaces of the pixel electrodes 111. In the display device 100 configured in this manner, for example, the insulating layer 103 can have recesses between the EL layers 112 and between the EL layer 112 and the PD layer 155. As will be described in detail later, the recesses are formed when the EL layer 112 and the PD layer 155 are formed.

[0125] [Structure Example 2] Although FIG. 1B illustrates a structure in which the conductive layer 131 is in contact with the pixel electrode 111S, one embodiment of the present invention is not limited to this. FIG. 3A illustrates a modification of the structure illustrated in FIG. 1B, in which the conductive layer 131 is provided over the substrate 101 and the insulating layer 102 is provided to cover the conductive layer 131. In the structure illustrated in FIG. 3A, the insulating layer 103 is provided over the insulating layer 102. Furthermore, the pixel electrode 111S is provided so as to have a region overlapping with the conductive layer 131. The insulating layer 102 can be formed using a material similar to that which can be used for the protective layer 121. Note that the insulating layer 102 is preferably planarized, but does not have to be planarized.

[0126] 3B is an enlarged view of region 133 shown in FIG. 3A. As shown in FIG. 3B, by providing conductive layer 131 that is reflective to visible light so as to have an area overlapping with pixel electrode 111S and PD layer 155, even if conductive layer 131 and pixel electrode 111S are not in contact, light 135 incident on the substrate 101 side can be prevented from entering PD layer 155 via pixel electrode 111S. Therefore, a decrease in imaging sensitivity of display device 100 due to light 135 can be suitably prevented.

[0127] By configuring the display device 100 as shown in FIGS. 3A and 3B, the area of ​​the conductive layer 131 as viewed from above can be increased. For example, the area of ​​the conductive layer 131 as viewed from above can be made equal to or greater than the area of ​​the pixel electrode 111S as viewed from above. Furthermore, for example, the area of ​​the conductive layer 131 as viewed from above can be made equal to or greater than the area of ​​the PD layer 155 as viewed from above. As a result, light 135 incident on the substrate 101 side can be effectively prevented from entering the PD layer 155, thereby effectively preventing a decrease in the imaging sensitivity of the display device 100 due to the light 135. Meanwhile, the display device 100 configured as shown in FIGS. 2A and 2B can be fabricated using a simple process. This reduces the fabrication cost of the display device 100, making it an affordable display device. Note that a light-shielding layer, such as an insulating light-shielding layer, may be provided instead of the conductive layer 131.

[0128] [Configuration Example 3] Figure 4A is a modified example of the configuration shown in Figure 1B, illustrating an example in which the conductive layer 131 is not provided. In the example shown in Figure 4A, the pixel electrodes 111R, 111G, 111B, and 111S can be conductive layers that are reflective to visible light. The pixel electrodes 111R, 111G, 111B, and 111S can be made of the same material as the conductive layer 131. Note that in the display device 100 having the configuration shown in Figure 4A, the pixel electrodes 111R, 111G, and 111B may be conductive layers that are transparent to visible light, and the pixel electrode 111S may be a conductive layer that is reflective to visible light. In other words, the pixel electrodes 111R, 111G, and 111B may be separately formed from the pixel electrode 111S.

[0129] 4B is an enlarged view of region 133 shown in FIG. 4A . Since insulating layer 127 is translucent to visible light, if substrate 101 and common electrode 115 are translucent to visible light, external light 135 can pass through display device 100 even if pixel electrode 111 is reflective to visible light. Therefore, a user of display device 100 can view the scenery (transmission image) behind display device 100 as a real image through display device 100. Furthermore, a user of display device 100 can view an image displayed by light-emitting element 130 superimposed on the transmission image of display device 100. This allows display device 100 to perform, for example, augmented reality (AR) display.

[0130] 4A and 4B, the manufacturing process of the display device 100 can be simplified. Therefore, the manufacturing cost of the display device 100 can be reduced, and the display device 100 can be an inexpensive display device. On the other hand, the display device 100 having the configuration shown in FIGS. 1B and 2 can be a display device with high transmittance of light 135.

[0131] 5A is a modified example of the configuration shown in Fig. 1B, and shows an example in which the end of the EL layer 112 and the end of the PD layer 155 are located more inward than the end of the pixel electrode 111. Specifically, Fig. 5A shows an example in which the end of the EL layer 112R is located more inward than the end of the pixel electrode 111R, the end of the EL layer 112G is located more inward than the end of the pixel electrode 111G, the end of the EL layer 112B is located more inward than the end of the pixel electrode 111B, and the end of the PD layer 155 is located more inward than the end of the pixel electrode 111S.

[0132] 5A is configured so that the EL layer 112 and the PD layer 155 do not cover the ends of the pixel electrodes 111, thereby preventing steps from occurring in the EL layer 112 and the PD layer 155. This prevents steps from occurring in the EL layer 112 and the PD layer 155, making the display device 100 a highly reliable display device.

[0133] 5B1 is a modified example of the configuration shown in FIG. 1B , and shows an example in which an insulating layer 117 is provided between adjacent light-emitting elements 130 and light-receiving elements 150, and between two adjacent light-emitting elements 130. The insulating layer 117 is provided so as to cover the edge of the pixel electrode 111. Areas of the EL layer 112 and the PD layer 155 that are not in contact with the pixel electrode 111 are provided on the insulating layer 117. Therefore, the display device 100 configured as shown in FIG. 5B1 has areas around the edge of the pixel electrode 111 where the insulating layer 117 is provided between the pixel electrode 111 and the EL layer 112 and the PD layer 155.

[0134] A protective layer 146 is provided on the EL layer 112 and the PD layer 155 so as to have an area overlapping with the insulating layer 117. An insulating layer 125 is provided on the protective layer 146 and the insulating layer 117, and an insulating layer 126 and an insulating layer 127 are provided on the insulating layer 125. As shown in FIG. 5B1 , the insulating layer 117 may have recesses between the EL layers 112 and between the EL layer 112 and the PD layer 155. The recesses are formed as the EL layer 112 and the PD layer 155 are formed.

[0135] By providing the insulating layer 117 so as to cover the edges of the pixel electrodes 111, it is possible to prevent short circuits between adjacent pixel electrodes 111. Here, by using an organic material, such as an organic resin, for the insulating layer 117, the edges can be made to have gently curved surfaces. This improves the coverage of layers provided on the insulating layer 117. Furthermore, the insulating layer 117 can be configured to have a region with a flattened upper surface.

[0136] Examples of organic materials that can be used for the insulating layer 117 include acrylic resin, epoxy resin, polyimide resin, polyamide resin, polyimideamide resin, polysiloxane resin, benzocyclobutene-based resin, and phenol resin.

[0137] Fig. 5B2 is a modified example of the configuration shown in Fig. 5B1, in which the edges of the insulating layer 117 are angular and the top surface of the insulating layer 117 is not flattened. The insulating layer 117 shown in Fig. 5B2 can be made of, for example, an inorganic material.

[0138] Examples of inorganic materials that can be used for the insulating layer 117 include silicon oxide, aluminum oxide, gallium oxide, germanium oxide, yttrium oxide, zirconium oxide, lanthanum oxide, neodymium oxide, hafnium oxide, tantalum oxide, silicon nitride, aluminum nitride, silicon oxynitride, aluminum oxynitride, silicon nitride oxide, and aluminum nitride oxide.

[0139] [Manufacturing Method Example 1] An example of a manufacturing method of a display device according to one embodiment of the present invention will be described below with reference to the drawings. Here, the display device 100 shown in the above configuration example will be described as an example.

[0140] Thin films (insulating films, semiconductor films, conductive films, etc.) constituting the display device can be formed using a sputtering method, a CVD method, a vacuum deposition method, a PLD method, an ALD method, etc. CVD methods include a plasma enhanced chemical vapor deposition (PECVD) method and a thermal CVD method. One type of thermal CVD method is a metal organic chemical vapor deposition (MOCVD) method. Furthermore, ALD methods include a PEALD method and a thermal ALD method.

[0141] Furthermore, thin films (insulating films, semiconductor films, conductive films, etc.) constituting the display device can be formed by methods such as spin coating, dipping, spray coating, inkjet, dispensing, screen printing, offset printing, doctor knife method, slit coating, roll coating, curtain coating, or knife coating.

[0142] Furthermore, when processing the thin film that constitutes the display device, for example, a photolithography method can be used. Alternatively, the thin film may be processed by a nanoimprint method, a sandblasting method, a lift-off method, or the like. Furthermore, the island-shaped thin film may be directly formed by a film formation method using a shielding mask such as a metal mask.

[0143] There are two typical photolithography methods: one is to form a resist mask on the thin film to be processed, process the thin film by etching, and then remove the resist mask; the other is to form a photosensitive thin film, and then process the thin film into the desired shape by exposure and development.

[0144] In photolithography, the light used for exposure can be, for example, i-line (wavelength 365 nm), g-line (wavelength 436 nm), h-line (wavelength 405 nm), or a mixture of these. Other light sources that can be used include ultraviolet light, KrF laser light, ArF laser light, etc. Exposure can also be performed by immersion exposure technology. Extreme ultraviolet (EUV) light or X-rays can also be used as the light used for exposure. An electron beam can also be used instead of the light used for exposure. Extreme ultraviolet light, X-rays, or an electron beam are preferred because they enable extremely fine processing. When exposure is performed by scanning a beam such as an electron beam, a photomask is not required.

[0145] The thin film can be etched by dry etching, wet etching, sandblasting, or the like.

[0146] 6A to 11B are schematic cross-sectional views showing an example of a method for manufacturing a display device 100 in which the light-emitting element 130 and the light-receiving element 150 have the configuration shown in FIG. 1B and the connection section 140 has the configuration shown in FIG. 1C1.

[0147] To manufacture the display device 100, first, an insulating layer 103 is formed on a substrate 101 that is transparent to visible light. Then, a conductive layer 131 is formed on the insulating layer 103 (FIG. 6A). For example, the conductive layer 131 can be formed by forming a conductive film that is reflective to visible light on the insulating layer 103 and then removing a part of the conductive film by etching.

[0148] Next, the pixel electrodes 111R, 111G, 111B, and the connection electrode 113 are formed on the insulating layer 103, and the pixel electrode 111S is formed on the conductive layer 131 ( FIG. 6B ). For example, a conductive film that is transparent to visible light is formed on the insulating layer 103 and the conductive layer 131, and part of the conductive film is removed by etching to form the pixel electrodes 111R, 111G, 111B, 111S, and the connection electrode 113. Here, by forming the pixel electrode 111S so as to cover the conductive layer 131, etching of the conductive layer 131 during the formation of the pixel electrode 111S can be suppressed even if the etching selectivity between the conductive layer 131 and the pixel electrode 111S is low.

[0149] Next, an EL film 112Rf, which will later become the EL layer 112R, is formed on the pixel electrodes 111R, 111G, 111B, and 111S, and on the insulating layer 103. Here, the EL film 112Rf can be provided so as not to overlap with the connection electrode 113. For example, by forming the EL film 112Rf while shielding the area including the connection electrode 113 with a metal mask, the EL film 112Rf can be formed so as not to overlap with the connection electrode 113. Because the metal mask used in this case does not need to shield the pixel area of ​​the display unit, there is no need to use a high-resolution mask, and a rough metal mask, for example, can be used.

[0150] The EL film 112Rf includes at least a film (light-emitting film) containing a light-emitting compound. The EL film 112Rf preferably includes a light-emitting film and a film that functions as a carrier transport layer on the light-emitting film. This prevents the light-emitting film from being exposed to the outermost surface during the manufacturing process of the display device 100, thereby reducing damage to the light-emitting film. This improves the reliability of the display device 100.

[0151] The EL film 112Rf may also be configured by stacking one or more films functioning as a hole injection layer, a hole transport layer, a hole blocking layer, an electron blocking layer, an electron transport layer, or an electron injection layer. For example, the EL film 112Rf may be configured by stacking a film functioning as a hole injection layer, a film functioning as a hole transport layer, a light-emitting film, and a film functioning as an electron transport layer in this order. Alternatively, the EL film 112Rf may be configured by stacking a film functioning as an electron injection layer, a film functioning as an electron transport layer, a light-emitting film, and a film functioning as a hole transport layer in this order.

[0152] The EL film 112Rf can be formed by, for example, a vapor deposition method, a sputtering method, an inkjet method, etc. However, the method is not limited to these, and the above-mentioned film formation methods can be used appropriately.

[0153] Next, a sacrificial film 144Ra is formed on the EL film 112Rf, the connection electrode 113, and the insulating layer 103, and a sacrificial film 144Rb is formed on the sacrificial film 144Ra. That is, a sacrificial film having a two-layer laminated structure is formed on the EL film 112Rf, the connection electrode 113, and the insulating layer 103. The sacrificial film may be a single layer, or may have a laminated structure of three or more layers. When a sacrificial film is formed in a subsequent process, a sacrificial film having a two-layer laminated structure is also formed, but it may be a single layer, or may have a laminated structure of three or more layers.

[0154] The sacrificial films 144Ra and 144Rb can be formed by, for example, sputtering, CVD, ALD, or vacuum deposition. Note that a formation method that causes less damage to the EL film is preferable, and the sacrificial film 144Ra that is formed directly on the EL film 112Rf is preferably formed by the ALD or vacuum deposition.

[0155] As the sacrificial film 144Ra, a metal film, an alloy film, a metal oxide film, a semiconductor film, an inorganic film such as an inorganic insulating film, or an organic film such as an organic insulating film can be suitably used.

[0156] Alternatively, an oxide film can be used as the sacrificial film 144Ra. Typically, an oxide film or an oxynitride film such as silicon oxide, silicon oxynitride, aluminum oxide, aluminum oxynitride, hafnium oxide, or hafnium oxynitride can be used. Alternatively, a nitride film, for example, can be used as the sacrificial film 144Ra. Specifically, nitrides such as silicon nitride, aluminum nitride, hafnium nitride, titanium nitride, tantalum nitride, tungsten nitride, gallium nitride, or germanium nitride can also be used. Films containing such inorganic insulating materials can be formed using a film formation method such as sputtering, CVD, or ALD. However, it is particularly preferable to form the sacrificial film 144Ra formed directly on the EL film 112Rf using ALD.

[0157] The sacrificial film 144Ra may be made of a metal material such as nickel, tungsten, chromium, molybdenum, cobalt, palladium, titanium, aluminum, silver, yttrium, zirconium, or tantalum, or an alloy material containing such a metal material. In particular, it is preferable to use a low-melting-point material such as aluminum or silver.

[0158] Alternatively, the sacrificial film 144Ra may be made of a metal oxide such as indium gallium zinc oxide (In—Ga—Zn oxide). Other examples include 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), and indium gallium tin zinc oxide (In—Ga—Sn—Zn oxide). Alternatively, for example, indium tin oxide containing silicon may be used.

[0159] The present invention can also be applied to a case where an element M (wherein M is one or more elements selected from aluminum, silicon, boron, yttrium, copper, vanadium, beryllium, titanium, iron, nickel, germanium, zirconium, molybdenum, lanthanum, cerium, neodymium, hafnium, tantalum, tungsten, and magnesium) is used instead of the gallium. In particular, it is preferable that M is one or more elements selected from gallium, aluminum, and yttrium.

[0160] The sacrificial film 144Rb can be made of any of the materials that can be used for the sacrificial film 144Ra listed above. For example, one of the materials that can be used for the sacrificial film 144Ra listed above can be selected for the sacrificial film 144Ra, and another can be selected for the sacrificial film 144Rb. Furthermore, one or more materials can be selected for the sacrificial film 144Ra from the materials that can be used for the sacrificial film 144Ra listed above, and one or more materials selected from the materials selected for the sacrificial film 144Ra can be used for the sacrificial film 144Rb.

[0161] Specifically, it is preferable to use aluminum oxide formed by ALD as the sacrificial film 144Ra and silicon nitride formed by sputtering as the sacrificial film 144Rb. In this configuration, the film formation temperature during film formation by ALD and sputtering is preferably set to a temperature between room temperature and 120°C, and preferably between room temperature and 100°C, since this reduces the impact on the EL film 112Rf. Furthermore, in the case of a stacked structure of the sacrificial films 144Ra and 144Rb, it is preferable that the stress of the stacked structure be small. Specifically, it is preferable that the stress of the stacked structure be between -500 MPa and +500 MPa, and more preferably between -200 MPa and +200 MPa, since this reduces process problems such as film peeling and delamination.

[0162] The sacrificial film 144Ra may be a film that is highly resistant to the etching process of each EL film such as the EL film 112Rf, i.e., a film with a large etching selectivity. It is particularly preferable to use a film that can be removed by wet etching, which causes little damage to each EL film, for the sacrificial film 144Ra.

[0163] The sacrificial film 144Ra may also be made of a material that can be dissolved in a chemically stable solvent. In particular, materials that dissolve in water or alcohol are suitable for use as the sacrificial film 144Ra. When forming the sacrificial film 144Ra, it is preferable to apply the sacrificial film 144Ra dissolved in a solvent such as water or alcohol using a wet film formation method, and then perform a heat treatment to evaporate the solvent. Performing the heat treatment under a reduced pressure atmosphere is preferable because it allows the solvent to be removed at a low temperature and in a short time, thereby reducing thermal damage to the EL film 112Rf.

[0164] Wet film formation methods that can be used to form the sacrificial film 144Ra include spin coating, dipping, spray coating, inkjet, dispensing, screen printing, offset printing, doctor knife method, slit coating, roll coating, curtain coating, and knife coating.

[0165] The sacrificial film 144Ra may be made of an organic material such as polyvinyl alcohol (PVA), polyvinyl butyral, polyvinyl pyrrolidone, polyethylene glycol, polyglycerin, pullulan, water-soluble cellulose, or alcohol-soluble polyamide resin.

[0166] The sacrificial film 144Rb may be a film having a large etching selectivity with respect to the sacrificial film 144Ra.

[0167] The sacrificial film 144Ra is preferably made of an inorganic insulating material such as aluminum oxide, hafnium oxide, or silicon oxide formed by an ALD method, and the sacrificial film 144Rb is preferably made of a metal material such as nickel, tungsten, chromium, molybdenum, cobalt, palladium, titanium, aluminum, yttrium, zirconium, or tantalum, or an alloy material containing such a metal material, formed by a sputtering method. In particular, tungsten formed by a sputtering method is preferably used for the sacrificial film 144Rb. Alternatively, a metal oxide containing indium, such as indium gallium zinc oxide (In—Ga—Zn oxide), formed by a sputtering method may be used for the sacrificial film 144Rb. Furthermore, an inorganic material may also be used for the sacrificial film 144Rb. For example, an oxide film or a nitride film, such as a silicon oxide film, a silicon oxynitride film, a silicon nitride oxide film, a silicon nitride film, an aluminum oxide film, an aluminum oxynitride film, or a hafnium oxide film, may be used.

[0168] Alternatively, the sacrificial film 144Rb may be an organic film that can be used for the EL film 112Rf. For example, the same organic film as that used for the EL film 112Rf can be used as the sacrificial film 144Rb. Using such an organic film is preferable because it allows the EL film 112Rf and the sacrificial film 144Rb to be formed using the same film-forming equipment. Furthermore, the sacrificial film 144Rb can be removed simultaneously when etching the EL film 112Rf, thereby simplifying the process.

[0169] Next, a resist mask 143a is formed on the sacrificial film 144Rb (FIG. 6C). The resist mask 143a can be made of a resist material containing a photosensitive resin, such as a positive resist material or a negative resist material.

[0170] Next, the portions of the sacrificial films 144Rb and 144Ra that are not covered by the resist mask 143a are removed by etching to form island-shaped or strip-shaped sacrificial layers 145Rb and 145Ra (FIG. 6D). As shown in FIG. 6D, the sacrificial layers 145Rb and 145Ra can be formed on the pixel electrode 111R and the connection electrode 113, for example.

[0171] Here, it is preferable to etch away a portion of the sacrificial film 144Rb using the resist mask 143a, form the sacrificial layer 145Rb, remove the resist mask 143a, and then etch the sacrificial film 144Ra using the sacrificial layer 145Rb as a hard mask. In this case, it is preferable to use etching conditions that provide a high selectivity with respect to the sacrificial film 144Ra for etching the sacrificial film 144Rb. While wet etching or dry etching can be used for etching to form the hard mask, using dry etching can suppress pattern shrinkage.

[0172] The sacrificial films 144Ra and 144Rb can be processed and the resist mask 143a can be removed by wet etching or dry etching. For example, the sacrificial films 144Ra and 144Rb can be processed by dry etching using a gas containing fluorine. The resist mask 143a can be removed by dry etching (also called plasma ashing) using a gas containing oxygen (also called oxygen gas).

[0173] When the sacrificial film 144Ra is etched using the sacrificial layer 145Rb as a hard mask, the resist mask 143a can be removed in a state where the EL film 112Rf is covered with the sacrificial film 144Ra. For example, if the EL film 112Rf comes into contact with oxygen, it may adversely affect the electrical characteristics of the light-emitting element 130R. Therefore, when the resist mask 143a is removed by a method using oxygen gas, such as plasma ashing, it is preferable to etch the sacrificial film 144Ra using the sacrificial layer 145Rb as a hard mask.

[0174] Next, a portion of the EL film 112Rf that is not covered by the sacrificial layer 145Ra is removed by etching to form an island-shaped or strip-shaped EL layer 112R (FIG. 6E). Here, as shown in FIG. 6E, if the end of the pixel electrode 111R has a tapered shape and the EL layer 112R covers the end of the pixel electrode 111R, the EL layer 112R can have a tapered portion 116R.

[0175] Dry etching using oxygen gas for etching the EL film 112Rf can increase the etching rate. Therefore, etching can be performed under low power conditions while maintaining a sufficiently high etching rate, thereby reducing damage caused by etching. Furthermore, problems such as adhesion of reaction products generated during etching to the EL layer 112R can be suppressed.

[0176] On the other hand, if the EL film 112Rf is etched by a dry etching method using an etching gas that does not contain oxygen as a main component, the deterioration of the EL film 112Rf can be suppressed, and the display device 100 can be made into a highly reliable display device. ４ , C ４ F ８ , S.F. ６ , CHF ３ , Cl ２ , H ２ O, or BCl ３ or a gas containing a Group 18 element such as He. A mixed gas of the above gas and a dilution gas not containing oxygen can be used as the etching gas. Note that the etching of the EL film 112Rf is not limited to the above, and may be performed by dry etching using other gases or wet etching.

[0177] If impurities adhere to the side surfaces of the EL layer 112R when the EL film 112Rf is etched to form the EL layer 112R, the impurities may penetrate into the EL layer 112R in subsequent processes. This may result in a decrease in the reliability of the display device 100. Therefore, it is preferable to remove the impurities adhered to the surface of the EL layer 112R after the EL layer 112R is formed, as this can increase the reliability of the display device 100.

[0178] Impurities adhering to the surface of the EL layer 112R can be removed, for example, by irradiating the surface of the EL layer 112R with an inert gas. Here, the surface of the EL layer 112R is exposed immediately after the formation of the EL layer 112R. Specifically, the side surfaces of the EL layer 112R are exposed. Therefore, after the formation of the EL layer 112R, for example, by placing the substrate on which the EL layer 112R is formed under an inert gas atmosphere, impurities adhering to the EL layer 112R can be removed. As the inert gas, for example, any one or more selected from Group 18 elements (typically, helium, neon, argon, xenon, krypton, etc.) and nitrogen can be used.

[0179] It should be noted that when processing the EL film 112Rf, a method of processing it directly above the light-emitting film of the EL film 112Rf using photolithography is conceivable. In this case, damage (e.g., damage due to processing) may occur in the light-emitting layer, which may significantly impair reliability. Therefore, to fabricate the display device 100, sacrificial layers 145Ra and 145Rb are formed on a film located above the light-emitting film (e.g., a film functioning as a carrier transport layer or carrier injection layer, more specifically, an electron transport layer, hole transport layer, electron injection layer, or hole injection layer), and the light-emitting film is processed. This allows the display device 100 to be a highly reliable display device.

[0180] Next, an EL film 112Gf, which will later become the EL layer 112G, is formed on the sacrificial layer 145Rb, the pixel electrodes 111G, 111B, and 111S, and on the insulating layer 103. By forming the EL film 112Gf after forming the sacrificial layer 145Ra, it is possible to prevent the EL film 112Gf from contacting the upper surface of the EL layer 112R. For example, with regard to the formation of the EL film 112Gf, the description of the formation of the EL film 112Rf can be referred to.

[0181] Next, a sacrificial film 144Ga is formed on the EL film 112Gf, the sacrificial layer 145Rb, and the insulating layer 103, and a sacrificial film 144Gb is formed on the sacrificial film 144Ga. After that, a resist mask 143b is formed on the sacrificial film 144Gb ( FIG. 7A ). For the formation of the sacrificial film 144Ga, the sacrificial film 144Gb, and the resist mask 143b, the descriptions of the formation of the sacrificial film 144Ra, the sacrificial film 144Rb, and the resist mask 143a can be referred to, respectively.

[0182] Next, portions of the sacrificial films 144Gb and 144Ga that are not covered by the resist mask 143b are removed by etching to form island- or strip-shaped sacrificial layers 145Gb and 145Ga. The resist mask 143b is then removed ( FIG. 7B ). Here, the sacrificial layers 145Gb and 145Ga can be formed on the pixel electrode 111G. For the formation of the sacrificial layers 145Gb and 145Ga and the removal of the resist mask 143b, the description of the formation of the sacrificial layers 145Rb and 145Ra and the removal of the resist mask 143a can be referenced.

[0183] Next, a portion of the EL film 112Gf that is not covered by the sacrificial layer 145Ga is removed by etching to form an island-shaped or strip-shaped EL layer 112G (FIG. 7C). Here, as shown in FIG. 7C, if the end of the pixel electrode 111G has a tapered shape and the EL layer 112G covers the end of the pixel electrode 111G, the EL layer 112G can have a tapered portion 116G.

[0184] For example, the description of the formation of the EL layer 112G can be referred to for the formation of the EL layer 112R. As with the EL layer 112R, it is preferable to remove impurities adhering to the surface of the EL layer 112G. For example, after the EL layer 112G is formed, the impurities adhering to the EL layer 112G can be removed by placing the substrate on which the EL layer 112G is formed under an inert gas atmosphere.

[0185] When processing the EL film 112Gf, the sacrificial layers 145Ga and 145Gb are formed on the film located above the light-emitting film, and the light-emitting film is processed. This makes it possible to make the display device 100 a highly reliable display device.

[0186] Next, an EL film 112Bf, which will later become the EL layer 112B, is formed on the sacrificial layer 145Rb, the sacrificial layer 145Gb, the pixel electrode 111B, the pixel electrode 111S, and the insulating layer 103. By forming the EL film 112Bf after the formation of the sacrificial layer 145Ga, it is possible to prevent the EL film 112Bf from contacting the upper surface of the EL layer 112G. For example, with regard to the formation of the EL film 112Bf, the description of the formation of the EL film 112Rf can be referred to.

[0187] Next, a sacrificial film 144Ba is formed on the EL film 112Bf, the sacrificial layer 145Rb, and the insulating layer 103, and a sacrificial film 144Bb is formed on the sacrificial film 144Ba. Then, a resist mask 143c is formed on the sacrificial film 144Bb ( FIG. 8A ). For the formation of the sacrificial film 144Ba, the sacrificial film 144Bb, and the resist mask 143c, the descriptions of the formation of the sacrificial film 144Ra, the sacrificial film 144Rb, and the resist mask 143a can be referred to, respectively.

[0188] Next, portions of the sacrificial films 144Bb and 144Ba that are not covered by the resist mask 143c are removed by etching to form island- or strip-shaped sacrificial layers 145Bb and 145Ba. The resist mask 143c is then removed ( FIG. 8B ). Here, the sacrificial layers 145Bb and 145Ba can be formed on the pixel electrode 111B. For the formation of the sacrificial layers 145Bb and 145Ba and the removal of the resist mask 143c, the description of the formation of the sacrificial layers 145Rb and 145Ra and the removal of the resist mask 143a can be referenced.

[0189] Next, a portion of the EL film 112Bf that is not covered by the sacrificial layer 145Ba is removed by etching to form an island-shaped or strip-shaped EL layer 112B (FIG. 8C). Here, as shown in FIG. 8C, if the end of the pixel electrode 111B has a tapered shape and the EL layer 112B covers the end of the pixel electrode 111B, the EL layer 112B can have a tapered portion 116B.

[0190] For example, the description of the formation of the EL layer 112B can be referred to for the formation of the EL layer 112R. As with the EL layers 112R and 112G, it is preferable to remove impurities attached to the surface of the EL layer 112B. For example, after the EL layer 112B is formed, the impurities attached to the EL layer 112B can be removed by placing the substrate on which the EL layer 112B is formed under an inert gas atmosphere.

[0191] When processing the EL film 112Bf, the sacrificial layers 145Ba and 145Bb are formed on the film located above the light-emitting film, and the light-emitting film is processed. This makes it possible to make the display device 100 a highly reliable display device.

[0192] Next, a PD film 155f, which will later become the PD layer 155, is formed on the sacrificial layers 145Rb, 145Gb, 145Bb, the pixel electrode 111S, and the insulating layer 103. By forming the PD film 155f after forming the sacrificial layer 145Ba, it is possible to prevent the PD film 155f from coming into contact with the EL layer 112B. For example, the formation of the PD film 155f can be referred to the description of the formation of the EL film 112Rf.

[0193] The PD film 155f includes a film (photoelectric conversion film) containing a photoelectric conversion material that is sensitive to at least visible light or infrared light. The PD film 155f preferably includes a photoelectric conversion film and a film that functions as a carrier transport layer on the photoelectric conversion film. This prevents the photoelectric conversion film from being exposed to the outermost surface during the manufacturing process of the display device 100, reducing damage to the photoelectric conversion film. This improves the reliability of the display device 100.

[0194] The PD film 155f may also be configured by laminating one or more films functioning as a hole transport layer, a hole blocking layer, an electron blocking layer, or an electron transport layer. For example, the PD film 155f may be configured by laminating a film functioning as a hole transport layer, a photoelectric conversion film, and a film functioning as an electron transport layer in this order. Alternatively, the PD film 155f may be configured by laminating a film functioning as an electron transport layer, a photoelectric conversion film, and a film functioning as a hole transport layer in this order.

[0195] Next, a sacrificial film 144Sa is formed on the PD film 155f, the sacrificial layer 145Rb, and the insulating layer 103, and a sacrificial film 144Sb is formed on the sacrificial film 144Sa. Thereafter, a resist mask 143d is formed on the sacrificial film 144Sb ( FIG. 9A ). For the formation of the sacrificial film 144Sa, the sacrificial film 144Sb, and the resist mask 143d, the descriptions of the formation of the sacrificial film 144Ra, the sacrificial film 144Rb, and the resist mask 143a can be referred to, respectively.

[0196] Next, portions of the sacrificial films 144Sb and 144Sa that are not covered by the resist mask 143d are removed by etching to form island- or strip-shaped sacrificial layers 145Sb and 145Sa. The resist mask 143d is then removed ( FIG. 9B ). Here, the sacrificial layers 145Sb and 145Sa can be formed on the pixel electrodes 111S. For the formation of the sacrificial layers 145Sb and 145Sa and the removal of the resist mask 143d, the description of the formation of the sacrificial layers 145Rb and 145Ra and the removal of the resist mask 143a can be referenced.

[0197] Next, a portion of the PD film 155f that is not covered by the sacrificial layer 145Sa is removed by etching to form an island-shaped or strip-shaped PD layer 155 (FIG. 9C). Here, as shown in FIG. 9C, if the end of the pixel electrode 111S has a tapered shape and the PD layer 155 covers the end of the pixel electrode 111S, the PD layer 155 can have a tapered portion 116S.

[0198] For example, the description of the formation of the EL layer 112R can be referred to for the formation of the PD layer 155. As with the EL layers 112R, 112G, and 112B, it is also preferable to remove impurities adhering to the surface of the PD layer 155. For example, after the PD layer 155 is formed, the impurities adhering to the PD layer 155 can be removed by placing the substrate on which the PD layer 155 is formed under an inert gas atmosphere.

[0199] When processing the PD film 155f, the sacrificial layers 145Sa and 145Sb are formed on the film located above the photoelectric conversion film, and the photoelectric conversion film is processed. This makes it possible to make the display device 100 a highly reliable display device.

[0200] 6C to 9C , the EL layer 112R, the EL layer 112G, the EL layer 112B, and the PD layer 155 can be separately formed. Note that in the above steps, the EL layer 112R, the EL layer 112G, the EL layer 112B, and the PD layer 155 are formed in this order, but the order in which the EL layer 112R, the EL layer 112G, the EL layer 112B, and the PD layer 155 are formed is not particularly limited. For example, the EL layer 112 may be formed after the PD layer 155 is formed.

[0201] Next, the sacrificial layers 145Rb, 145Gb, 145Bb, and 145Sb are removed, for example, by etching ( FIG. 9D ). The sacrificial layers 145Rb, 145Gb, 145Bb, and 145Sb are preferably removed by a method that has high selectivity with respect to the sacrificial layers 145Ra, 145Ga, 145Ba, and 145Sa. For example, the sacrificial layers 145Rb, 145Gb, 145Bb, and 145Sb can be removed using a dry etching method. The sacrificial layers 145Rb, 145Gb, 145Bb, and 145Sb may not be removed immediately after the formation of the EL layer 112R, EL layer 112G, EL layer 112B, or PD layer 155, but may be removed in a later process.

[0202] Subsequently, an insulating film 125f, which will later become the insulating layer 125, is formed so as to cover the upper surface of the insulating layer 103, the side surfaces of the EL layer 112 and the PD layer 155, and the side surfaces and upper surface of the sacrificial layer 145a.

[0203] In this specification and the like, when describing matters common to, for example, sacrificial layer 145Ra, sacrificial layer 145Ga, sacrificial layer 145Ba, and sacrificial layer 145Sa, they may be referred to as sacrificial layer 145a. Also, when describing matters common to sacrificial layer 145a and sacrificial layer 145b, they may be referred to as sacrificial layer 145. Other components may also be described using symbols with the alphabet omitted, as described above.

[0204] The insulating film 125f can be formed by a sputtering method, a CVD method, a PLD method, an ALD method, or the like, but is preferably formed by an ALD method because of its good coverage. For example, an inorganic material can be used as the insulating film 125f, such as an oxide insulating film, a nitride insulating film, an oxynitride insulating film, or a nitride oxide insulating film. In particular, the insulating film 125f can be an inorganic insulating film such as an aluminum oxide film, a hafnium oxide film, or a silicon oxide film formed by an ALD method, which can result in an insulating film with few pinholes.

[0205] Next, an insulating film 126f, which will later become the insulating layer 126, is formed on the insulating film 125f (FIG. 10A). The insulating film 126f may be made of, for example, an organic material. The insulating film 126f may be made of, for example, a color resist. When the insulating film 126f is made of a color resist, it is preferable to use a negative resist, which reduces the solubility of exposed portions, as the insulating film 126f.

[0206] When a color resist is used as the insulating film 126f, the insulating film 126f can be formed by a spin coating method, a spray method, a screen printing method, a painting method, or the like.

[0207] 10A, the insulating film 126f may have gentle unevenness that reflects the unevenness of the surface on which it is formed. Also, the insulating film 126f may be flattened.

[0208] Next, an insulating layer 126 is formed between the adjacent EL layer 112 and PD layer 155 ( FIG. 10B ). Here, by using a photosensitive material such as color resist as the insulating film 126f, the insulating layer 126 can be formed without providing an etching mask such as a resist mask or a hard mask. Furthermore, because photosensitive materials such as color resist can be processed using only exposure and development steps, the insulating layer 126 can be formed without using, for example, dry etching. This simplifies the process. Furthermore, damage to the EL layer 112 and the PD layer 155 caused by etching the insulating film 126f can be reduced.

[0209] Alternatively, the insulating layer 126 may be formed by etching the upper surface of the insulating film 126f in a substantially uniform manner. Such uniform etching and planarization is also called etch-back. Note that the formation of the insulating layer 126 may involve a combination of an exposure and development process and an etch-back process.

[0210] Furthermore, the insulating film 126f may be processed by, for example, dry etching to form the insulating layer 126. In this case, the insulating film 126f may be made of a material that does not have photosensitivity.

[0211] Next, an insulating film 127f, which will later become the insulating layer 127, is formed on the insulating film 125f and the insulating layer 126 ( FIG. 10C ). The insulating film 127f may be, for example, an organic material. The insulating film 127f may be, for example, a photoresist. When the insulating film 127f is a photoresist, the insulating film 127f may be either a negative resist, which reduces the solubility of the exposed portion, or a positive resist, which increases the solubility of the exposed portion.

[0212] When a photoresist is used as the insulating film 127f, the insulating film 127f can be formed by a spin coating method, a spraying method, a screen printing method, a painting method, or the like.

[0213] 10C, the insulating film 127f may have gentle unevenness that reflects the unevenness of the surface on which it is formed. Also, the insulating film 127f may be flattened.

[0214] Next, an insulating layer 127 is formed between two adjacent EL layers 112 ( FIG. 10D ). Specifically, the insulating layer 127 can be formed in a region where the insulating layer 125 will be formed in a later process but where the insulating layer 126 is not formed. Here, by using a photosensitive material such as photoresist as the insulating film 127f, the insulating layer 127 can be formed without providing an etching mask such as a resist mask or a hard mask. Furthermore, because photosensitive materials such as photoresist can be processed using only exposure and development processes, the insulating layer 127 can be formed without using, for example, dry etching. This simplifies the process. Furthermore, damage to the EL layer 112 and the PD layer 155 caused by etching the insulating film 127f can be reduced.

[0215] Here, when a photosensitive material is used for the insulating film 127f, if a positive resist is used for the insulating layer 126, the insulating layer 126 may dissolve and disappear during development of the insulating film 127f. Therefore, as described above, it is preferable to use a negative resist for the insulating film 126f that becomes the insulating layer 126.

[0216] Furthermore, the upper surface of the insulating film 127f may be etched back. In forming the insulating layer 127, the exposure and development steps may be combined with the etch back step.

[0217] Furthermore, the insulating layer 127 may be formed by processing the insulating film 127f by, for example, dry etching. In this case, a material that does not have photosensitivity may be used as the insulating film 127f. In addition, not only a negative resist but also a positive resist may be used as the insulating layer 126.

[0218] The insulating layer 127 has a higher transmittance for light of a specific wavelength, which is at least a portion of the wavelengths of visible light, than the transmittance for light of the specific wavelength in the insulating layer 126. The insulating layer 127 can also have a higher transmittance for light of at least one color, for example, red, green, and blue, than the transmittance for light of the insulating layer 126.

[0219] 10A to 10D , it is possible to separately form the insulating layer 126 provided between adjacent EL layers 112 and PD layers 155 and the insulating layer 127 provided between two adjacent EL layers 112. Specifically, for example, in the region where the insulating layer 125 will be formed in a later process, the insulating layer 126 can be formed between the adjacent EL layers 112 and PD layers 155, and the insulating layer 127 can be formed in the other region. Here, if a negative resist is used as the insulating layer 127, the insulating layer 126 can be formed after the insulating layer 127 is formed. Furthermore, even if a photosensitive material is not used for the insulating layer 127, the insulating layer 126 can be formed after the insulating layer 127 is formed.

[0220] Next, the sacrificial layer 145a is etched to form the protective layer 146, and the insulating film 125f is etched to form the insulating layer 125 (FIG. 11A). Here, since the protective layer 146 is formed by etching the sacrificial layer 145a, the protective layer 146 can also be called a sacrificial layer.

[0221] The sacrificial layer 145a and the insulating film 125f can be etched using the insulating layer 126 and the insulating layer 127 as a mask. Therefore, the insulating layer 125 and the protective layer 146 are formed so as to overlap the insulating layer 126, and the insulating layer 125 and the protective layer 146 are also formed so as to overlap the insulating layer 127. Note that if the step shown in Fig. 9D is not performed, that is, if the insulating film 125f is formed without removing the sacrificial layer 145b after the formation of the PD layer 155, the protective layer 146 is formed by etching the sacrificial layer 145b and the sacrificial layer 145a.

[0222] The sacrificial layer 145a is preferably etched by a method that minimizes damage to the EL layer 112 and the PD layer 155. The sacrificial layer 145a can be etched by, for example, wet etching.

[0223] Etching the insulating film 125f by anisotropic etching is preferable because the insulating layer 125 can be suitably formed without patterning using, for example, photolithography. For example, forming the insulating layer 125 without patterning using photolithography can simplify the manufacturing process of the display device 100, thereby reducing the manufacturing cost of the display device 100. Therefore, the display device 100 can be an inexpensive display device. Examples of anisotropic etching include dry etching. When etching the insulating film 125f by dry etching, the insulating film 125f can be etched using an etching gas that can be used to etch the sacrificial film 144, for example.

[0224] Next, a vacuum bake process is performed to remove water adsorbed on, for example, the surface of the EL layer 112 and the surface of the PD layer 155. The vacuum bake is preferably performed within a temperature range that does not alter the organic compounds contained in, for example, the EL layer 112 and the PD layer 155, and can be performed at, for example, 70° C. or higher and 120° C. or lower, more preferably 80° C. or higher and 100° C. or lower. Note that, for example, if there is little water adsorbed on the surface of the EL layer 112 and the surface of the PD layer 155 and the effect on the reliability of the display device 100 is small, the vacuum bake process may not be performed.

[0225] Next, the common layer 114 is formed on the EL layer 112, the PD layer 155, the insulating layer 126, the insulating layer 127, and the connection electrode 113. As described above, the common layer 114 has at least one of a hole injection layer, a hole transport layer, a hole blocking layer, an electron blocking layer, an electron transport layer, or an electron injection layer, for example, an electron injection layer or a hole injection layer. The common layer 114 can be formed by, for example, a vapor deposition method, a sputtering method, an inkjet method, or the like. Note that, if the common layer 114 is not provided on the connection electrode 113, a metal mask that shields the connection electrode 113 may be used in forming the common layer 114. The metal mask used in this case does not need to shield the pixel region of the display unit, so a high-resolution mask is not required, and a rough metal mask, for example, may be used.

[0226] Subsequently, the common electrode 115 is formed on the common layer 114. The common electrode 115 can be formed by, for example, a sputtering method, a vacuum deposition method, or the like. As described above, the common electrode 115 can be a light-transmitting conductive layer.

[0227] Next, a protective layer 121 is formed on the common electrode 115 (FIG. 11B). When an inorganic insulating film is used as the protective layer 121, it is preferable to form the protective layer 121 by, for example, a sputtering method, a CVD method, or an ALD method. When an organic insulating film is used as the protective layer 121, it is preferable to form the protective layer 121 by, for example, an inkjet method, because this allows a uniform film to be formed in a desired area.

[0228] Through the above steps, the display device 100 can be manufactured.

[0229] In this specification etc., a device fabricated using a metal mask or an FMM (fine metal mask, high-resolution metal mask) may be referred to as a device with an MM (metal mask) structure. Also, in this specification etc., a device fabricated without using a metal mask or an FMM may be referred to as a device with an MML (metal maskless) structure.

[0230] 6A to 11B, the island-shaped EL layer 112 is formed by depositing an EL film 112f on the entire surface and then processing it, rather than by using a metal mask pattern. Similarly, the island-shaped PD layer 155 is formed by depositing a PD film 155f on the entire surface and then processing it, rather than by using a metal mask pattern.

[0231] As a result, a high-definition or high-aperture display device and an imaging device can be realized. Furthermore, a display device having an imaging function and a high-definition or high-aperture ratio can be realized. Furthermore, since the EL layer 112 can be produced in different colors, a display device with extremely vivid images, high contrast, and high display quality can be realized. Furthermore, by providing a sacrificial layer on the EL layer 112 and the PD layer 155, damage to the EL layer 112 and the PD layer 155 during the manufacturing process of the display device 100 can be reduced, thereby improving the reliability of the light-emitting element 130 and the light-receiving element 150.

[0232] Furthermore, the display device 100 can be configured so that no insulating material is provided to cover the end of the pixel electrode 111. In other words, the display device 100 is configured so that no insulating layer is provided between the pixel electrode 111 and the EL layer 112 provided in the light-emitting element 130, and between the pixel electrode 111 and the PD layer 155 provided in the light-receiving element 150. With this configuration, light emitted from the EL layer 112 can be extracted efficiently, and light irradiated onto the PD layer 155 can be detected with high sensitivity.

[0233] The display device 100 can efficiently extract light from the EL layer 112, thereby significantly reducing viewing angle dependency. For example, the viewing angle (the maximum angle at which a certain contrast ratio is maintained when the screen is viewed from an oblique direction) of the display device 100 can be set to a range of 100° to less than 180°, preferably 150° to 170°. Note that the above viewing angle can be applied to both the vertical and horizontal directions. The display device of one embodiment of the present invention can reduce viewing angle dependency and improve image visibility.

[0234] When the display device 100 is a device with a fine metal mask (FMM) structure, there may be restrictions on the pixel arrangement, for example. Here, the device with the FMM structure will be described below.

[0235] When forming a device with an FMM structure, a metal mask (FMM) with openings is set opposite the substrate so that EL is deposited in the desired area during EL deposition. Then, EL deposition is performed through the FMM, resulting in EL deposition in the desired area. As the area of ​​the substrate on which EL is deposited increases, the area of ​​the FMM also increases, and the weight of the FMM also increases. Furthermore, the FMM may be deformed during EL deposition, for example, due to heat applied to the FMM. For example, there is a method in which a certain tension is applied to the FMM during EL deposition, so the weight and strength of the FMM are important parameters.

[0236] Therefore, when designing a pixel arrangement configuration using an FMM, for example, the above parameters must be taken into consideration and consideration must be given under certain restrictions. On the other hand, since the display device of one embodiment of the present invention is a device with an MML structure, it exhibits excellent effects, such as a higher degree of freedom in pixel arrangement configuration compared to devices with an FMM structure. Note that the MML structure has a higher degree of design freedom than the FMM structure, and therefore is highly compatible with, for example, flexible devices.

[0237] [Fabrication Method Example 2] FIGS. 12A to 14B are schematic cross-sectional views showing an example of a fabrication method for the display device 100, which is different from the method shown in FIGS. 6A to 11B.

[0238] First, the same processes as those shown in FIGS. 6A to 9D are performed. As a result, pixel electrodes 111R, 111G, and 111B, a conductive layer 131, and a connection electrode 113 are formed on the insulating layer 103. Furthermore, a pixel electrode 111S is formed on the conductive layer 131. Furthermore, an EL layer 112R is formed on the pixel electrode 111R, an EL layer 112G is formed on the pixel electrode 111G, an EL layer 112B is formed on the pixel electrode 111B, and a PD layer 155 is formed on the pixel electrode 111S. Furthermore, a sacrificial layer 145Ra is formed on the EL layer 112R and the connection electrode 113, a sacrificial layer 145Ga is formed on the EL layer 112G, a sacrificial layer 145Ba is formed on the EL layer 112B, and a sacrificial layer 145Sa is formed on the PD layer 155 (FIG. 12A). The process shown in FIG. 9D does not necessarily need to be performed. In this case, a sacrificial layer 145b remains on the sacrificial layer 145a.

[0239] Next, an insulating film 125f, which will later become the insulating layer 125, is formed to cover the top surface of the insulating layer 103, the side surfaces of the EL layer 112 and the PD layer 155, and the side surfaces and top surface of the sacrificial layer 145a. As described above, the insulating film 125f can be formed using a sputtering method, a CVD method, a PLD method, an ALD method, or the like, but is preferably formed using the ALD method, which has good coverage. Furthermore, for example, an inorganic material can be used as the insulating film 125f, and inorganic insulating films such as an oxide insulating film, a nitride insulating film, an oxynitride insulating film, and a nitride oxide insulating film can be used. In particular, by using an inorganic insulating film such as an aluminum oxide film, a hafnium oxide film, or a silicon oxide film formed by the ALD method as the insulating film 125f, an insulating film with few pinholes can be obtained.

[0240] Next, an insulating film 127f, which will later become the insulating layer 127, is formed on the insulating film 125f (FIG. 12B). As described above, the insulating film 127f may be made of, for example, an organic material. The insulating film 127f may be made of, for example, photoresist. When photoresist is used as the insulating film 127f, the insulating film 127f may be formed by a method such as spin coating, spraying, screen printing, or painting.

[0241] Next, an insulating layer 127 is formed between two adjacent EL layers 112 ( FIG. 12C ). Specifically, the insulating layer 127 can be formed in a region where the insulating layer 125 will be formed in a later process, except for the region between the adjacent EL layer 112 and the PD layer 155. As described above, by using a photosensitive material such as photoresist as the insulating film 127f, the insulating layer 127 can be formed without providing an etching mask such as a resist mask or a hard mask. Furthermore, because photosensitive materials such as photoresist can be processed using only exposure and development processes, the insulating layer 127 can be formed without using, for example, dry etching. This simplifies the process. Furthermore, damage to the EL layer 112 and the PD layer 155 caused by etching the insulating film 127f can be reduced.

[0242] Next, a protective film 147f is formed on the insulating layer 127 and the insulating film 125f (FIG. 12D). The protective film 147f can be formed using the same material as that used for the insulating film 125f. The protective film 147f can also be formed using the same material as that used for the sacrificial film 144b. For example, the protective film 147f can be formed using an inorganic material, specifically an inorganic insulating film such as an oxide insulating film, a nitride insulating film, an oxynitride insulating film, or a nitride oxide insulating film. The protective film 147f can also be formed using a metal material. Furthermore, the protective film 147f can also be formed using a metal oxide such as indium gallium zinc oxide.

[0243] The protective film 147f can be formed by a sputtering method, a CVD method, a PLD method, an ALD method, or the like; however, like the insulating film 125f, it is preferably formed by an ALD method, which has good coverage.

[0244] Next, an insulating film 126f, which will later become the insulating layer 126, is formed on the protective film 147f (FIG. 13A). As described above, the insulating film 126f can be made of, for example, an organic material. The insulating film 126f can be made of, for example, a color resist. When using a color resist as the insulating film 126f, the insulating film 126f can be formed using a spin coating method, a spray method, a screen printing method, a painting method, or the like.

[0245] Next, an insulating layer 126 is formed between the adjacent EL layer 112 and PD layer 155 ( FIG. 13B ). As described above, by using a photosensitive material such as color resist as the insulating film 126f, the insulating layer 126 can be formed without providing an etching mask such as a resist mask or a hard mask. Furthermore, because photosensitive materials such as color resist can be processed using only exposure and development steps, the insulating layer 126 can be formed without using, for example, dry etching. This simplifies the process. Furthermore, damage to the EL layer 112 and the PD layer 155 caused by etching the insulating film 126f can be reduced.

[0246] After forming the insulating layer 127, a protective film 147f is formed and then the insulating film 126f is formed on the protective film 147f, thereby preventing the insulating film 126f from coming into contact with the insulating layer 127. This prevents the insulating layer 127 from dissolving and disappearing during development of the insulating film 126f, even when a positive resist is used as the insulating layer 127. This allows for a wider range of material options for the insulating layer 127. Note that after forming the insulating layer 126, a protective film 147f may be formed on the insulating layer 126, and then the insulating layer 127 may be formed on the protective film 147f.

[0247] Next, the protective film 147f is etched to form the protective layer 147 (FIG. 13C). The protective film 147f is located below the insulating layer 126 and above the insulating layer 127, and can be etched using the insulating layer 126 as a mask. Thus, the protective layer 147 is formed so as to overlap the insulating layer 126.

[0248] The protective film 147f can be etched by the same method as the etching of the sacrificial film 144a. For example, the protective film 147f can be etched by wet etching. Alternatively, the protective film 147f may be etched by dry etching.

[0249] Next, the sacrificial layer 145a is etched to form the protective layer 146, and the insulating film 125f is etched to form the insulating layer 125 (FIG. 14A). As described above, the sacrificial layer 145a can be etched by, for example, wet etching, and the insulating film 125f can be etched by dry etching.

[0250] Next, a vacuum bake process is performed to remove water adsorbed on, for example, the surface of the EL layer 112 and the surface of the PD layer 155. As described above, the vacuum bake is preferably performed within a temperature range that does not alter the organic compounds contained in, for example, the EL layer 112 and the PD layer 155, and can be performed, for example, at a temperature of 70° C. or higher and 120° C. or lower, more preferably 80° C. or higher and 100° C. or lower. Note that, for example, if there is little water adsorbed on the surface of the EL layer 112 and the surface of the PD layer 155 and the effect on the reliability of the display device 100 is small, the vacuum bake process may not be performed.

[0251] Next, a common layer 114 is formed on the EL layer 112, the PD layer 155, the insulating layer 126, the insulating layer 127, and the connection electrode 113. Thereafter, a common electrode 115 is formed on the common layer 114, and a protective layer 121 is formed on the common electrode 115 ( FIG. 14B ).

[0252] Through the above steps, the display device 100 can be manufactured.

[0253] At least a part of the configuration examples exemplified in this embodiment and the corresponding drawings can be combined as appropriate with other configuration examples or drawings.

[0254] This embodiment mode can be implemented by appropriately combining at least a part thereof with other embodiment modes described in this specification.

[0255] Embodiment 2 In this embodiment, a display device according to one embodiment of the present invention will be described.

[0256] The display device of this embodiment can be a high-resolution display device or a large-sized display device. Therefore, the display device of this embodiment can be used in electronic devices having relatively large screens, such as television devices, desktop or notebook personal computers, computer monitors, digital signage, and large game machines such as pachinko machines, as well as in the display units of digital cameras, digital video cameras, digital photo frames, mobile phones, portable game machines, personal digital assistants, and sound reproduction devices.

[0257] FIG. 15 shows a perspective view of the display device 100, and FIG. 16A shows a cross-sectional view of the display device 100.

[0258] The display device 100 has a configuration in which a substrate 101 and a substrate 105 are bonded together. In Fig. 15, the substrate 105 is clearly indicated by a dashed line.

[0259] The display device 100 includes a display unit 107, a connection unit 140, a circuit 164, wiring 165, and the like. Fig. 15 shows an example in which an IC 173 and an FPC 172 are mounted on the display device 100. Therefore, the configuration shown in Fig. 15 can also be called a display module including the display device 100, an IC (integrated circuit), and an FPC. Here, a display device in which a connector such as an FPC is attached to a substrate or an IC is mounted on the substrate is called a display module.

[0260] The connection portion 140 is provided outside the display portion 107. The connection portion 140 can be provided along one side or multiple sides of the display portion 107. The number of connection portions 140 may be single or multiple. FIG. 15 shows an example in which the connection portion 140 is provided so as to surround the four sides of the display portion. The connection portion 140 electrically connects the common electrode of the light-emitting element and the conductive layer, and can supply a potential to the common electrode.

[0261] The circuit 164 can be, for example, a scanning line driver circuit.

[0262] The wiring 165 has a function of supplying signals and power to the display portion 107 and the circuit 164. The signals and power are input to the wiring 165 from the outside via the FPC 172 or from the IC 173.

[0263] 15 shows an example in which an IC 173 is provided on the substrate 101 by a COG method, a COF (chip on film) method, or the like. The IC 173 can be, for example, an IC having a scanning line driver circuit or a signal line driver circuit. Note that the display device 100 and the display module may not be provided with an IC. Alternatively, the IC may be mounted on an FPC by, for example, a COF method.

[0264] Figure 16A shows an example of a cross section of the display device 100 when cutting a portion of the area including the FPC 172, a portion of the circuit 164, a portion of the display unit 107, a portion of the connection portion 140, and a portion of the area including the end portion.

[0265] 16A shows a configuration in which an insulating layer 127 is provided over the insulating layer 125 in a region other than the display region 107. Note that an insulating layer 126 may be provided in at least a part of the region over the insulating layer 125 in a region other than the display region 107.

[0266] 16A includes a transistor 201, a transistor 205, a light-emitting element 130, a light-receiving element 150, and the like between a substrate 101 and a substrate 105. In FIG. 16A, the light-emitting element 130 includes a light-emitting element 130G and a light-emitting element 130B.

[0267] The substrate 105 transmits visible light, similarly to the substrate 101. For example, the substrate 105 can be the same as the substrate that can be used for the substrate 101.

[0268] 1B except that the configuration of the pixel electrodes is different. For details of the light emitting element 130 and the light receiving element 150, refer to Embodiment 1.

[0269] The light-emitting element 130 has a conductive layer 123 and a conductive layer 129 over the conductive layer 123. The light-receiving element 150 has a conductive layer 131, a conductive layer 123 over the conductive layer 131, and a conductive layer 129 over the conductive layer 123. Here, in the light-emitting element 130 and the light-receiving element 150, one or both of the conductive layer 123 and the conductive layer 129 can be called a pixel electrode.

[0270] The conductive layer 123 can be provided so as to cover the conductive layer 131, for example. The conductive layer 123 is connected to the conductive layer 222b of the transistor 205 through an opening provided in the insulating layer 103. Here, in the display device 100, the end portions of the conductive layer 123 and the conductive layer 129 are aligned or approximately aligned, but this is not limiting. For example, the conductive layer 129 may be provided so as to cover the end portions of the conductive layer 123.

[0271] As described above, the conductive layer 131 has a property of reflecting visible light. The conductive layer 123 and the conductive layer 129 each transmit visible light.

[0272] A recess is formed in the conductive layer 131 and the conductive layer 123 so as to cover the opening provided in the insulating layer 103. A layer 128 is buried in the recess.

[0273] The layer 128 has a function of planarizing the recessed portion of the conductive layer 123. A conductive layer 129 electrically connected to the conductive layer 123 is provided over the conductive layer 123 and the layer 128. Therefore, a region overlapping with the recessed portion of the conductive layer 123 can also be used as a light-emitting region, and the aperture ratio of the pixel can be increased. Note that, for example, when the area of ​​the layer 128 as viewed from the top surface is sufficiently smaller than the area of ​​the conductive layer 123 as viewed from the top surface, the conductive layer 129 does not need to be provided.

[0274] The layer 128 can be a layer that transmits visible light. The layer 128 may be an insulating layer or a conductive layer. Various inorganic insulating materials, organic insulating materials, and conductive materials can be used as appropriate for the layer 128. In particular, the layer 128 is preferably formed using an insulating material.

[0275] An insulating layer containing an organic material can be suitably used as the layer 128. For example, acrylic resin, polyimide resin, epoxy resin, polyamide resin, polyimideamide resin, siloxane resin, benzocyclobutene resin, phenolic resin, precursors of these resins, or the like can be used as the layer 128. Alternatively, a photosensitive resin can be used as the layer 128. The photosensitive resin can be a positive-type material or a negative-type material.

[0276] By using a photosensitive resin, the layer 128 can be formed only through exposure and development steps, and the influence of dry etching, wet etching, or the like on the surface of the conductive layer 123 can be reduced. Furthermore, by forming the layer 128 using a negative photosensitive resin, the layer 128 can be formed using the same photomask (exposure mask) as that used to form the openings in the insulating layer 103 in some cases.

[0277] The upper surface and side surfaces of the conductive layer 129 are covered with the EL layer 112 or the PD layer 155. Note that the side surfaces of the conductive layer 129 do not necessarily have to be covered with the EL layer 112 or the PD layer 155. Furthermore, a portion of the upper surface of the conductive layer 129 does not necessarily have to be covered with the EL layer 112 or the PD layer 155.

[0278] A protective layer 146 is provided to cover a portion of the upper surface of the EL layer 112, and another protective layer 146 is provided to cover a portion of the upper surface of the PD layer 155. An insulating layer 125 is provided to cover the upper surface and side surfaces of the protective layer 146, the side surfaces of the EL layer 112, and the side surfaces of the PD layer 155. An insulating layer 126 is provided on the insulating layer 125 between the EL layer 112 and the PD layer 155, and an insulating layer 127 is provided on the insulating layer 125 between two adjacent EL layers 112. Specifically, for example, the insulating layer 126 can be provided between adjacent EL layers 112 and PD layers 155 in the region on the insulating layer 125, and the insulating layer 127 can be provided in the other region. A common layer 114 is provided on the EL layer 112, the PD layer 155, the insulating layer 126, and the insulating layer 127, and a common electrode 115 is provided on the common layer 114. The common layer 114 and the common electrode 115 are continuous films provided in common to the plurality of light-emitting elements 130 and the plurality of light-receiving elements 150, respectively.

[0279] Furthermore, a protective layer 121 is provided on the light-emitting element 130 and the light-receiving element 150. By providing the protective layer 121 that covers the light-emitting element 130 and the light-receiving element 150, impurities such as water can be prevented from entering the light-emitting element 130 and the light-receiving element 150, and the reliability of the light-emitting element 130 and the light-receiving element 150 can be improved.

[0280] The protective layer 121 and the substrate 105 are bonded via an adhesive layer 142. A solid sealing structure, a hollow sealing structure, or the like can be applied to seal the light-emitting element. In FIG. 16A , the space between the substrate 105 and the substrate 101 is filled with the adhesive layer 142, and a solid sealing structure is applied. Alternatively, the space may be filled with an inert gas (nitrogen, argon, or the like), and a hollow sealing structure may be applied. In this case, the adhesive layer 142 may be provided so as not to overlap with the light-emitting element 130 and the light-receiving element 150. Furthermore, the space may be filled with a resin different from the frame-shaped adhesive layer.

[0281] In the connection portion 140, a connection electrode 113 is provided on the insulating layer 103. FIG. 16A shows an example in which the connection electrode 113 has a laminated structure of a conductive film obtained by processing the same conductive film as the conductive layer 123 and a conductive film obtained by processing the same conductive film as the conductive layer 129. The side surfaces of the connection electrode 113 are covered with a protective layer 146. An insulating layer 125 is provided on the protective layer 146, and an insulating layer 127 is provided on the insulating layer 125. A common layer 114 is provided on the connection electrode 113, and a common electrode 115 is provided on the common layer 114. The connection electrode 113 and the common electrode 115 are electrically connected via the common layer 114. Note that the common layer 114 does not necessarily have to be formed in the connection portion 140. In this case, the connection electrode 113 and the common electrode 115 are in direct contact with each other and are electrically connected.

[0282] The transistor 201 and the transistor 205 are both formed over a substrate 101. These transistors can be manufactured using the same material and through the same process.

[0283] An insulating layer 211, an insulating layer 213, an insulating layer 215, and an insulating layer 103 are provided over the substrate 101 in this order. A part of the insulating layer 211 functions as a gate insulating layer for each transistor. A part of the insulating layer 213 functions as a gate insulating layer for each transistor. The insulating layer 215 is provided to cover the transistor. The insulating layer 103 is provided to cover the transistor and functions as a planarization layer. Note that the number of gate insulating layers and the number of insulating layers covering the transistors are not limited, and each may be a single layer or two or more layers.

[0284] At least one insulating layer covering the transistor is preferably made of a material that is resistant to the diffusion of impurities such as water and hydrogen. This allows the insulating layer to function as a barrier layer. With this structure, it is possible to effectively prevent impurities from diffusing into the transistor from the outside, thereby improving the reliability of the display device.

[0285] It is preferable to use an inorganic insulating film for each of the insulating layers 211, 213, and 215. Examples of the inorganic insulating film that can be used include a silicon nitride film, a silicon oxynitride film, a silicon oxide film, a silicon nitride oxide film, an aluminum oxide film, and an aluminum nitride film. Alternatively, a hafnium oxide film, an yttrium oxide film, a zirconium oxide film, a gallium oxide film, a tantalum oxide film, a magnesium oxide film, a lanthanum oxide film, a cerium oxide film, and a neodymium oxide film may also be used. Two or more of the above insulating films may be stacked.

[0286] An organic insulating layer is suitable for the insulating layer 103, which functions as a planarizing layer. Materials that can be used for the organic insulating layer include acrylic resin, polyimide resin, epoxy resin, polyamide resin, polyimideamide resin, siloxane resin, benzocyclobutene-based resin, phenolic resin, and precursors of these resins. The insulating layer 103 may also have a laminated structure of an organic insulating layer and an inorganic insulating film. The outermost layer of the insulating layer 103 preferably functions as an etching protection film. This can prevent recesses from being formed in the insulating layer 103 during processing of the conductive layer 123, the conductive layer 129, etc. Alternatively, recesses may be formed in the insulating layer 103 during processing of the conductive layer 123, the conductive layer 129, etc.

[0287] The transistor 201 and the transistor 205 each include a conductive layer 221 that functions as a gate, an insulating layer 211 that functions as a gate insulating layer, conductive layers 222a and 222b that function as a source and a drain, a semiconductor layer 231, an insulating layer 213 that functions as a gate insulating layer, and a conductive layer 223 that functions as a gate. Here, the same hatching pattern is applied to multiple layers obtained by processing the same conductive film. The insulating layer 211 is located between the conductive layer 221 and the semiconductor layer 231. The insulating layer 213 is located between the conductive layer 223 and the semiconductor layer 231.

[0288] Here, at least some of the layers constituting the transistor 201 and the transistor 205 preferably have a light-transmitting property to visible light. For example, the conductive layer 222a and the conductive layer 222b preferably have a light-transmitting property to visible light. As described above, the substrate 101, the conductive layer 123, the layer 128, the conductive layer 129, the insulating layer 127, the common electrode 115, the substrate 105, and the like can transmit visible light and thus can transmit light 135, which is external light. Therefore, a user of the display device 100 can view a scene (transmitted image) behind the display device 100 as a real image through the display device 100. Therefore, when at least some of the layers constituting the transistor 201 and the transistor 205 have a light-transmitting property to visible light, the transmittance of the light 135 in the display device 100 can be increased.

[0289] Furthermore, the conductive layer 221 and the conductive layer 223 may be light-transmitting or reflective to visible light. When the conductive layer 221 and the conductive layer 223 are light-transmitting to visible light, the transmittance of light 135 in the display device 100 can be increased. On the other hand, when the conductive layer 221 and the conductive layer 223 are reflective to visible light, the light 135 can be prevented from entering the semiconductor layer 231. Therefore, damage to the semiconductor layer 231 can be reduced, and the reliability of the display device 100 can be improved.

[0290] 16A shows, in addition to light 135, light 136G emitted from EL layer 112G, light 136B emitted from EL layer 112B, and light 137 incident on PD layer 155. As shown in Fig. 16A, display device 100 can be a dual-emission display device.

[0291] The structure of the transistor included in the display device of this embodiment is not particularly limited. For example, a planar transistor, a staggered transistor, an inverted staggered transistor, or the like can be used. Furthermore, either a top-gate transistor or a bottom-gate transistor structure may be used. Alternatively, gates may be provided above and below a semiconductor layer in which a channel is formed.

[0292] The transistor 201 and the transistor 205 have a structure in which a semiconductor layer in which a channel is formed is sandwiched between two gates. The two gates may be connected and the same signal may be supplied to drive the transistor. Alternatively, the threshold voltage of the transistor may be controlled by applying a potential for controlling the threshold voltage to one of the two gates and a potential for driving to the other.

[0293] The crystallinity of a semiconductor material used for a transistor is not particularly limited, and any of an amorphous semiconductor and a crystalline semiconductor (a microcrystalline semiconductor, a polycrystalline semiconductor, a single crystal semiconductor, or a semiconductor having a crystalline region in part) may be used. The use of a crystalline semiconductor is preferable because it can suppress deterioration of transistor characteristics.

[0294] The semiconductor layer of the transistor preferably includes a metal oxide (also referred to as an oxide semiconductor). That is, the display device of this embodiment preferably includes a transistor using a metal oxide for a channel formation region (hereinafter referred to as an OS transistor).

[0295] Examples of crystalline oxide semiconductors include c-axis-aligned crystalline (CAAC)-OS, nanocrystalline (nc)-OS, and the like.

[0296] Alternatively, a transistor using silicon for a channel formation region (Si transistor) may be used. Examples of silicon include single crystal silicon, polycrystalline silicon, and amorphous silicon. In particular, a transistor having low temperature polysilicon (LTPS) in a semiconductor layer (hereinafter also referred to as an LTPS transistor) may be used. An LTPS transistor has high field-effect mobility and favorable frequency characteristics.

[0297] By using Si transistors such as LTPS transistors, circuits that need to be driven at high frequencies (such as source driver circuits) can be built on the same substrate as the display unit, which simplifies the external circuits mounted on the display device and reduces component and mounting costs.

[0298] An OS transistor has significantly higher field-effect mobility than a transistor using amorphous silicon. Furthermore, an OS transistor has significantly lower source-drain leakage current in an off state (hereinafter also referred to as off-state current), and can hold charge accumulated in a capacitor connected in series with the transistor for a long period of time. Furthermore, the use of an OS transistor can reduce the power consumption of a display device.

[0299] The off-state current of the OS transistor per 1 μm of channel width at room temperature is 1 aA (1×10 −１８ A) Below, 1zA (1×10 −２１ A) or less, or 1yA (1 x 10 −２４ Note that the off-state current of a Si transistor per 1 μm of channel width at room temperature can be 1 fA (1×10 −１５ A) More than 1pA (1×10 −１２ Therefore, it can be said that the off-state current of an OS transistor is about 10 orders of magnitude lower than that of a Si transistor.

[0300] Furthermore, to increase the emission luminance of a light-emitting element included in a pixel circuit, it is necessary to increase the amount of current flowing through the light-emitting element. To achieve this, it is necessary to increase the source-drain voltage of a driving transistor included in the pixel circuit. Since an OS transistor has a higher source-drain withstand voltage than 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 a pixel circuit, it is possible to increase the amount of current flowing through the light-emitting element and increase the emission luminance of the light-emitting element.

[0301] Furthermore, when a transistor operates in a saturation region, an OS transistor can reduce the change in source-drain current with respect to a change in gate-source voltage compared to a Si transistor. Therefore, by using an OS transistor as a driving transistor included in a pixel circuit, the current flowing between the source and drain can be precisely controlled by changing the gate-source voltage, thereby controlling the amount of current flowing to a light-emitting element. This allows for a larger gradation level in the pixel circuit.

[0302] Furthermore, in terms of saturation characteristics of the current that flows when a transistor operates in a saturation region, an OS transistor can pass a more stable current (saturation current) than a Si transistor, even when the source-drain voltage gradually increases. Therefore, by using an OS transistor as a driving transistor, a stable current can be passed to a light-emitting element, even when the current-voltage characteristics of the light-emitting element vary. In other words, when an OS transistor operates in a saturation region, the source-drain current of the OS transistor remains almost unchanged even when the source-drain voltage increases, thereby stabilizing the light-emitting luminance of the light-emitting element.

[0303] As described above, by using an OS transistor for a driving transistor included in a pixel circuit, it is possible to achieve "suppression of black floating," "increase in light-emitting luminance," "multiple gradations," "suppression of variations in light-emitting elements," and the like.

[0304] The semiconductor layer preferably contains, for example, indium, M (wherein M is one or more elements selected from gallium, aluminum, silicon, boron, yttrium, tin, copper, vanadium, beryllium, titanium, iron, nickel, germanium, zirconium, molybdenum, lanthanum, cerium, neodymium, hafnium, tantalum, tungsten, and magnesium), and zinc. In particular, M is preferably one or more elements selected from aluminum, gallium, yttrium, and tin.

[0305] In particular, it is preferable to use an oxide containing indium (In), gallium (Ga), and zinc (Zn) (also referred to as IGZO) as the semiconductor layer. Alternatively, it is preferable to use an oxide containing indium, tin, and zinc. Alternatively, it is preferable to use an oxide containing indium, gallium, tin, and zinc. Alternatively, it is preferable to use an oxide containing indium (In), aluminum (Al), and zinc (Zn) (also referred to as IAZO). Alternatively, it is preferable to use an oxide containing indium (In), aluminum (Al), gallium (Ga), and zinc (Zn) (also referred to as IAGZO).

[0306] When the semiconductor layer is an In-M-Zn oxide, the atomic ratio of In in the In-M-Zn oxide is preferably equal to or greater than the atomic ratio of M. Examples of atomic ratios of metal elements in such In-M-Zn oxides include a composition in which In:M:Zn = 1:1:1 or thereabouts, a composition in which In:M:Zn = 1:1:1.2 or thereabouts, a composition in which In:M:Zn = 2:1:3 or thereabouts, a composition in which In:M:Zn = 3:1:2 or thereabouts, a composition in which In:M:Zn = 4:2:3 or thereabouts, a composition in which In:M:Zn = 4:2:4.1 or thereabouts, a composition in which In:M:Zn = 5:1:3 or thereabouts, a composition in which In:M:Zn = 5:1:6 or thereabouts, a composition in which In:M:Zn = 5:1:7 or thereabouts, a composition in which In:M:Zn = 5:1:8 or thereabouts, a composition in which In:M:Zn = 6:1:6 or thereabouts, and a composition in which In:M:Zn = 5:2:5 or thereabouts. The term "nearby composition" includes a range of ±30% of the desired atomic ratio.

[0307] For example, when describing a composition having an atomic ratio of In:Ga:Zn = 4:2:3 or thereabout, this includes a case where, when the atomic ratio of In is 4, the atomic ratio of Ga is 1 or more and 3 or less, and the atomic ratio of Zn is 2 or more and 4 or less. Furthermore, when describing a composition having an atomic ratio of In:Ga:Zn = 5:1:6 or thereabout, this includes a case where, when the atomic ratio of In is 5, the atomic ratio of Ga is more than 0.1 and 2 or less, and the atomic ratio of Zn is 5 or more and 7 or less. Furthermore, when describing a composition having an atomic ratio of In:Ga:Zn = 1:1:1 or thereabout, this includes a case where, when the atomic ratio of In is 1, the atomic ratio of Ga is more than 0.1 and 2 or less, and the atomic ratio of Zn is more than 0.1 and 2 or less.

[0308] The transistors included in the circuit 164 may have the same structure as or different from the transistors included in the display portion 107. The transistors included in the circuit 164 may all have the same structure or may have two or more types of structures. Similarly, the transistors included in the display portion 107 may all have the same structure or may have two or more types of structures.

[0309] All the transistors included in the display portion 107 may be OS transistors, all the transistors included in the display portion 107 may be Si transistors, or some of the transistors included in the display portion 107 may be OS transistors and the rest may be Si transistors.

[0310] For example, by using both an LTPS transistor and an OS transistor in the display portion 107, a display device with low power consumption and high driving capability can be realized. A structure in which an LTPS transistor and an OS transistor are combined is sometimes referred to as LTPO. Note that, as a more preferable example, it is preferable to use an OS transistor as a transistor that functions as a switch for controlling conduction and non-conduction between wirings, and to use an LTPS transistor as a transistor for controlling current.

[0311] For example, one of the transistors included in the display portion 107 functions as a transistor for controlling a current flowing to a light-emitting element and can be called a driving transistor. One of the source and drain of the driving transistor is electrically connected to a pixel electrode of the light-emitting element. It is preferable to use an LTPS transistor as the driving transistor. This can increase the current flowing to the light-emitting element in the pixel circuit.

[0312] On the other hand, another transistor included in the display portion 107 functions as a switch for controlling pixel selection / non-selection and can also be called a selection transistor. The gate of the selection transistor is electrically connected to a gate line, and one of the source and drain is electrically connected to a signal line. An OS transistor is preferably used as the selection transistor. This allows the gradation of a pixel to be maintained even when the frame frequency is significantly reduced (for example, 1 fps or less). Therefore, power consumption can be reduced by stopping the driver when a still image is displayed.

[0313] As described above, the display device of one embodiment of the present invention can have a high aperture ratio, high definition, high display quality, and low power consumption.

[0314] Note that a display device according to one embodiment of the present invention includes an OS transistor and a light-emitting element with an MML (metal maskless) structure. This structure can significantly reduce leakage current that may flow through the transistor and leakage current that may flow between adjacent light-emitting elements (also referred to as lateral leakage current or side leakage current, etc.). Furthermore, with this structure, when an image is displayed on the display device, a viewer can observe one or more of image clarity, image sharpness, high saturation, and a high contrast ratio. Note that a structure in which leakage current that may flow through the transistor and lateral leakage current between light-emitting elements are extremely low can minimize light leakage that may occur, for example, during black display.

[0315] 16B1 and 16B2 show other examples of transistor configurations.

[0316] The transistor 209 and the transistor 210 each include a conductive layer 221 functioning as a gate, an insulating layer 211 functioning as a gate insulating layer, a semiconductor layer 231 including a channel formation region 231i and a pair of low-resistance regions 231n, a conductive layer 222a connected to one of the pair of low-resistance regions 231n, a conductive layer 222b connected to the other of the pair of low-resistance regions 231n, an insulating layer 225 functioning as a gate insulating layer, a conductive layer 223 functioning as a gate, and an insulating layer 215 covering the conductive layer 223. The insulating layer 211 is located between the conductive layer 221 and the channel formation region 231i. The insulating layer 225 is located at least between the conductive layer 223 and the channel formation region 231i. Furthermore, an insulating layer 218 covering the transistor may be provided.

[0317] 16B1 shows an example in which the insulating layer 225 covers the top surface and side surfaces of the semiconductor layer 231. The conductive layer 222a and the conductive layer 222b are connected to the low-resistance region 231n through openings provided in the insulating layer 225 and the insulating layer 215, respectively. One of the conductive layer 222a and the conductive layer 222b functions as a source, and the other functions as a drain.

[0318] 16B2, the insulating layer 225 overlaps with the channel formation region 231i of the semiconductor layer 231 but does not overlap with the low-resistance region 231n. For example, the structure shown in Fig. 16B2 can be manufactured by processing the insulating layer 225 using the conductive layer 223 as a mask. In Fig. 16B2, the insulating layer 215 is provided to cover the insulating layer 225 and the conductive layer 223, and the conductive layer 222a and the conductive layer 222b are each connected to the low-resistance region 231n through openings in the insulating layer 215.

[0319] A connection portion 204 is provided in a region of the substrate 101 that does not overlap with the substrate 105. In the connection portion 204, the wiring 165 is electrically connected to the FPC 172 via a conductive layer 166 and a connection layer 242. The conductive layer 166 has an example of a stacked structure of a conductive film obtained by processing the same conductive film as the conductive layer 123 and a conductive film obtained by processing the same conductive film as the conductive layer 129. The conductive layer 166 is exposed on the top surface of the connection portion 204. This allows the connection portion 204 and the FPC 172 to be electrically connected via the connection layer 242.

[0320] The adhesive layer 142 can be made of various curable adhesives, such as a photo-curable adhesive (e.g., an ultraviolet-curable adhesive), a reactive curable adhesive, a heat-curable adhesive, or an anaerobic adhesive. Examples of such adhesives include epoxy resin, acrylic resin, silicone resin, phenolic resin, polyimide resin, imide resin, PVC (polyvinyl chloride) resin, PVB (polyvinyl butyral) resin, and EVA (ethylene vinyl acetate) resin. In particular, a material with low moisture permeability, such as epoxy resin, is preferable. A two-component resin may also be used. Alternatively, an adhesive sheet, for example, may also be used.

[0321] The connection layer 242 may be an anisotropic conductive film (ACF), an anisotropic conductive paste (ACP), or the like.

[0322] Materials that can be used for the gate, source, and drain of a transistor as well as conductive layers such as various wirings and electrodes that constitute a display device include metals such as aluminum, titanium, chromium, nickel, copper, yttrium, zirconium, molybdenum, silver, tantalum, and tungsten, and alloys containing these metals as main components, etc. Films containing these materials can be used as a single layer or a stacked layer structure.

[0323] Examples of light-transmitting conductive materials include conductive oxides such as indium oxide, indium tin oxide, indium zinc oxide, zinc oxide, and zinc oxide containing gallium, or graphene. Alternatively, metal materials such as gold, silver, platinum, magnesium, nickel, tungsten, chromium, molybdenum, iron, cobalt, copper, palladium, and titanium, or alloy materials containing such metal materials, can be used. Alternatively, nitrides of such metal materials (e.g., titanium nitride) can be used. When using metal materials or alloy materials (or their nitrides), it is preferable to thin the metal materials to ensure light-transmitting properties. A stacked film of the above materials can also be used as the conductive layer. For example, a stacked film of an alloy of silver and magnesium and indium tin oxide is preferable because it can enhance conductivity. These materials can also be used for conductive layers such as various wirings and electrodes constituting a display device, and for conductive layers (conductive layers functioning as pixel electrodes or common electrodes) of light-emitting elements.

[0324] Examples of insulating materials that can be used for each insulating layer include resins such as acrylic resin and epoxy resin, and inorganic insulating materials such as silicon oxide, silicon oxynitride, silicon nitride oxide, silicon nitride, and aluminum oxide.

[0325] Fig. 17 is a modified example of the configuration shown in Fig. 16A, and shows an example in which a light-shielding layer 118 is provided on an insulating layer 126. Fig. 17 shows an example in which a light-shielding layer 118 is provided on the surface of a substrate 105 facing the substrate 101.

[0326] By providing the light-shielding layer 118 on the insulating layer 126, it is possible to suitably prevent a portion of the light emitted from, for example, the EL layer 112 adjacent to the PD layer 155 from being incident on the PD layer 155 due to stray light. Therefore, the display device 100 shown in Fig. 17 can be a display device that can capture images with low noise and high imaging sensitivity.

[0327] Fig. 18 is a modified example of the configuration shown in Fig. 17, and shows an example in which the light-shielding layer 118 is provided not only on the insulating layer 126 but also below the insulating layer 126. Fig. 18 shows an example in which the light-shielding layer 118 is provided on the insulating layer 215 in addition to the surface of the substrate 105 facing the substrate 101.

[0328] As described above, the display device 100 can be a dual-emission display device. Therefore, by providing the light-shielding layers 118 both above and below the insulating layer 126, it is possible to effectively prevent, for example, a portion of the light emitted by the EL layer 112 adjacent to the PD layer 155 from being incident on the PD layer 155 due to stray light. Therefore, the display device 100 shown in FIG. 18 can be a display device capable of capturing images with low noise and high imaging sensitivity. It is also possible to provide the light-shielding layer 118 below the insulating layer 126, without providing the light-shielding layer 118 on the insulating layer 126.

[0329] Fig. 19 is a modified example of the configuration shown in Fig. 17 , and differs from the configuration shown in Fig. 17 in that a light-shielding layer 118 is provided on the circuit 164 and the connection portion 140. By configuring the display device 100 as shown in Fig. 19 , it is possible to prevent external light from passing through the circuit 164 and the connection portion 140.

[0330] 20A to 20D show cross-sectional structures of a region 138 including the conductive layer 123, the layer 128, and their surroundings in the display device 100. FIG.

[0331] 16A shows an example in which the top surface of layer 128 and the top surface of conductive layer 123 are roughly aligned, but the present invention is not limited to this. For example, as shown in Fig. 20A, the top surface of layer 128 may be higher than the top surface of conductive layer 123. In this case, the top surface of layer 128 has a shape that is gently bulging outward in a convex shape toward the center.

[0332] 20B, the upper surface of layer 128 may be lower than the upper surface of conductive layer 123. In this case, the upper surface of layer 128 has a gently sloping recessed shape that is concave toward the center.

[0333] 20C , when the upper surface of layer 128 is higher than the upper surface of conductive layer 123, the upper portion of layer 128 may be formed to extend beyond the recess formed in conductive layer 123. In this case, part of layer 128 may be formed to cover part of the approximately flat region of conductive layer 123.

[0334] 20D, in the structure shown in Fig. 20C, a recess may be further formed in part of the upper surface of layer 128. The recess has a shape that is gently recessed toward the center.

[0335] Fig. 21 is a perspective view of the display device 100. Fig. 21 is a modified example of the display device 100 shown in Fig. 15. Fig. 22 is a cross-sectional view of the display device 100 shown in Fig. 21.

[0336] In the display device 100 shown in FIGS. 21 and 22, a substrate 253 is provided in place of the substrate 101, and a substrate 106 is provided in place of the substrate 105.

[0337] An insulating layer 262 is provided over the substrate 253 with an adhesive layer 255 interposed therebetween. In other words, the substrate 253 and the insulating layer 262 are attached to each other by the adhesive layer 255. The transistor 201 and the transistor 205 are formed over the insulating layer 262. Moreover, an insulating layer 211, an insulating layer 213, an insulating layer 215, and an insulating layer 103 are provided over the insulating layer 262 in this order.

[0338] 22 , an insulating layer 262 is first formed over a formation substrate, and each transistor, the light-emitting element 130, the light-receiving element 150, and the like are formed over the insulating layer 262. Subsequently, a substrate 106 is attached to the light-emitting element 130, the light-receiving element 150, and the like with an adhesive layer 142. After that, the formation substrate is peeled off, and a substrate 253 is attached to the exposed surface with an adhesive layer 255, thereby transferring each component formed over the formation substrate to the substrate 253.

[0339] The substrate 253 and the substrate 106 transmit visible light. Furthermore, the substrate 253 and the substrate 106 are flexible substrates. This allows the display device 100 to have flexibility. That is, the display device 100 can be a flexible display.

[0340] The substrate 253 and the substrate 106 may be made of polyester resin such as polyethylene terephthalate (PET) or polyethylene naphthalate (PEN), polyacrylonitrile resin, acrylic resin, polyimide resin, polymethyl methacrylate resin, polycarbonate (PC) resin, polyethersulfone (PES) resin, polyamide resin (nylon, aramid, or the like), polysiloxane resin, cycloolefin resin, polystyrene resin, polyamideimide resin, polyurethane resin, polyvinyl chloride resin, polyvinylidene chloride resin, polypropylene resin, polytetrafluoroethylene (PTFE) resin, ABS resin, cellulose nanofiber, or the like. One or both of the substrate 253 and the substrate 106 may be made of glass having a thickness sufficient to provide flexibility.

[0341] The insulating layer 262 can be formed using a material that can be used for the insulating layer 211, the insulating layer 213, and the insulating layer 215, and is preferably formed using an inorganic insulating film. The adhesive layer 255 can be formed using a material that can be used for the adhesive layer 142.

[0342] As described above, the substrate 253, the conductive layer 123, the layer 128, the conductive layer 129, the insulating layer 127, the common electrode 115, the substrate 106, and the like can be transparent to visible light and thus can transmit light 135, which is external light. Therefore, a user of the display device 100 can see a view (transmission image) behind the display device 100 as a real image through the display device 100. Therefore, when at least a part of the layers constituting the transistor 201 and the transistor 205 is transparent to visible light, the transmittance of the light 135 in the display device 100 can be increased.

[0343] Fig. 23 is a modified example of the configuration shown in Fig. 22, and shows an example in which a light-shielding layer 118 is provided on the insulating layer 126. Fig. 23 shows an example in which the light-shielding layer 118 is provided on the surface of the substrate 106 facing the substrate 253.

[0344] By providing the light-shielding layer 118 on the insulating layer 126, it is possible to suitably prevent a portion of the light emitted from, for example, the EL layer 112 adjacent to the PD layer 155 from being incident on the PD layer 155 due to stray light. Therefore, the display device 100 shown in Fig. 23 can be a display device that can capture images with low noise and high imaging sensitivity.

[0345] Fig. 24 is a modified example of the configuration shown in Fig. 23, and shows an example in which the light-shielding layer 118 is provided not only on the insulating layer 126 but also below the insulating layer 126. Fig. 24 shows an example in which the light-shielding layer 118 is provided on the insulating layer 215 in addition to the surface of the substrate 106 facing the substrate 253.

[0346] As described above, the display device 100 can be a dual-emission display device. Therefore, by providing the light-shielding layers 118 both above and below the insulating layer 126, it is possible to effectively prevent, for example, a portion of the light emitted by the EL layer 112 adjacent to the PD layer 155 from being incident on the PD layer 155 due to stray light. Therefore, the display device 100 shown in FIG. 24 can be a display device capable of capturing images with low noise and high imaging sensitivity. It is also possible to provide the light-shielding layer 118 below the insulating layer 126, without providing the light-shielding layer 118 on the insulating layer 126.

[0347] Fig. 25 is a modified example of the configuration shown in Fig. 23, and differs from the configuration shown in Fig. 23 in that a light-shielding layer 118 is provided on the circuit 164 and the connection portion 140. By configuring the display device 100 as shown in Fig. 25, it is possible to prevent external light from passing through the circuit 164 and the connection portion 140.

[0348] At least a part of the configuration examples exemplified in this embodiment and the corresponding drawings can be combined as appropriate with other configuration examples or drawings.

[0349] This embodiment mode can be implemented by appropriately combining at least a part thereof with other embodiment modes or examples described in this specification.

[0350] Embodiment 3 In this embodiment, a display panel according to one embodiment of the present invention will be described.

[0351] One embodiment of the present invention is a display panel that can be enlarged by arranging multiple display panels so that they partially overlap. Furthermore, of the two overlapped display panels, at least the display panel located on the display surface side (upper side) has a portion that is adjacent to the display unit and transmits visible light. The pixels of the lower display panel overlap with the portion of the upper display panel that transmits visible light. This allows images displayed on the two display panels to be displayed continuously and seamlessly when viewed from the display surface side (in a plan view).

[0352] For example, a display panel according to one embodiment of the present invention is a stacked panel including a first display panel and a second display panel. The first display panel includes a first region, which includes a first pixel and a second pixel. The second display panel includes a second region, a third region, and a fourth region. The second region includes a third pixel, which has a function of transmitting visible light and a function of blocking visible light. The second pixel of the first display panel and the third region of the second display panel overlap each other. The aperture ratio of the second pixel is preferably larger than that of the first pixel.

[0353] The display device including the light-emitting element and the light-receiving element, as exemplified above, can be used for one or both of the first display panel and the second display panel. In other words, it can be said that at least one of the first pixel, the second pixel, and the third pixel has a light-emitting element and a light-receiving element.

[0354] More specifically, for example, the following configuration can be adopted.

[0355] 26A is a schematic top view of a display panel 500 included in a display panel of one embodiment of the present invention. The structure of the display device 100 shown in any of FIGS. 22 to 25 can be applied to the display panel 500. Note that in FIG. 26A , W represents the width. The same applies to other drawings.

[0356] The display panel 500 includes a display section 501, a region 510 adjacent to the display section 501 that transmits visible light, and a region 520 that has a portion that blocks visible light.

[0357] Here, the display panel 500 can display an image on the display portion 501 even when used alone, and can also capture an image using the display portion 501 .

[0358] The region 510 may be provided with, for example, a sealant for sealing a pair of substrates constituting the display panel 500 and a display element sandwiched between the pair of substrates. In this case, a material that transmits visible light is used for the member provided in the region 510.

[0359] The region 520 is provided with wirings electrically connected to pixels included in the display portion 501. In addition to such wirings, circuits such as driver circuits (scanning line driver circuits, signal line driver circuits, etc.) for driving the pixels or protective circuits may be provided. The region 520 also includes a region provided with terminals (also referred to as connection terminals) electrically connected to external terminals or wiring layers, or wirings electrically connected to the terminals.

[0360] Fig. 26B is a schematic top view showing an example of the configuration of a display panel 550 having the display panel 500 shown in Fig. 26A. Fig. 26B shows an example in which the display panel 550 has three display panels 500.

[0361] In the present embodiment, when describing display panels, components included in display panels, or components related to display panels, alphabets are added after their reference numerals. Unless otherwise specified, the reference numeral "a" is added to the display panel and its components arranged at the bottom (opposite the display surface) of multiple display panels, some of which are overlapped with each other, and the reference numerals of one or more display panels and their components arranged above it are added with alphabets in alphabetical order. Unless otherwise specified, even when describing a configuration including multiple display panels, the reference numerals are omitted when describing matters common to each display panel or component.

[0362] The display panel 550 shown in FIG. 26B includes a display panel 500a, a display panel 500b, and a display panel 500c.

[0363] The display panel 500b is disposed so that a portion thereof overlaps the upper side (display surface side) of the display panel 500a. Specifically, the display portion 501a of the display panel 500a and the region 510b of the display panel 500b that transmits visible light overlap with each other, and the display portion 501a of the display panel 500a and the region 520b of the display panel 500b that blocks visible light do not overlap with each other.

[0364] The display panel 500c is disposed such that a portion thereof overlaps the upper side (display surface side) of the display panel 500b. Specifically, the display portion 501b of the display panel 500b overlaps with the region 510c of the display panel 500c that transmits visible light, but the display portion 501b of the display panel 500b does not overlap with the region 520c of the display panel 500c that blocks visible light.

[0365] Since region 510b that transmits visible light is superimposed on display unit 501a, the entire display unit 501a can be viewed from the display surface side. Similarly, since region 510c is superimposed on display unit 501b, the entire display unit 501b can be viewed from the display surface side. Therefore, the region in which display units 501a, 501b, and 501c are seamlessly arranged can be used as display unit 551 of display panel 550.

[0366] The display panel 550 can expand the display section 551 by the number of display panels 500. In this case, by using a display panel with an imaging function (i.e., a display panel having pixels in which a light-emitting element and a light-receiving element are provided) for all the display panels 500, the entire area of ​​the display section 551 can be used as an imaging area.

[0367] [Configuration Example 2] Although FIG. 26B shows a configuration in which a plurality of display panels 500 are arranged overlapping in one direction, a plurality of display panels 500 may be arranged overlapping in two directions, that is, the vertical direction and the horizontal direction.

[0368] Fig. 27A is a schematic top view showing an example of a display panel 500 having a different shape of a region 510 from that of Fig. 26A. In the display panel 500 shown in Fig. 27A, regions 510 that transmit visible light are arranged along two sides of a display unit 501.

[0369] Fig. 27B is a schematic perspective view of a display panel 550 in which two display panels 500 shown in Fig. 27A are arranged vertically and two horizontally. Fig. 27C is a schematic perspective view of the display panel 550 as viewed from the opposite side to the display surface side.

[0370] 27B and 27C , a region along the short side of the display portion 501a of the display panel 500a overlaps with a portion of the region 510b of the display panel 500b. A region along the long side of the display portion 501a of the display panel 500a overlaps with a portion of the region 510c of the display panel 500c. A region 510d of the display panel 500d overlaps with a region along the long side of the display portion 501b of the display panel 500b and a region along the short side of the display portion 501c of the display panel 500c.

[0371] Therefore, as shown in FIG. 27B, it is possible to form a display section 551 of a display panel 550 in an area where the display sections 501a, 501b, 501c, and 501d are arranged seamlessly.

[0372] Here, it is preferable that a pair of substrates used in the display panel 500 be made of a flexible material, thereby making the display panel 500 flexible. In this way, as shown in the display panel 500a in Figures 27B and 27C, for example, a part of the display panel 500a can be curved and arranged so as to overlap the lower side of the display portion 501b of the adjacent display panel 500b.

[0373] Furthermore, by providing flexibility to each display panel 500, the display panel 500b can be gently curved so that the height of the upper surface of the display portion 501b of the display panel 500b matches the height of the upper surface of the display portion 501a of the display panel 500a. This makes it possible to align the heights of the display portions except for the vicinity of the area where the display panels 500a and 500b overlap, thereby improving the display quality of the image displayed on the display portion 551 of the display panel 550.

[0374] Although the above description has been given taking the relationship between the display panel 500a and the display panel 500b as an example, the same applies to the relationship between two adjacent display panels.

[0375] Furthermore, it is preferable that the thickness of the display panel 500 is thin in order to reduce the step between two adjacent display panels 500. For example, it is preferable that the thickness of the display panel 500 is 1 mm or less, preferably 300 μm or less, and more preferably 100 μm or less.

[0376] Furthermore, a substrate may be provided to protect the display unit 551 of the display panel 550. In this case, the substrate may be provided for each display panel, or one substrate may be provided across multiple display panels.

[0377] Although a configuration in which four rectangular display panels 500 are stacked is shown here, an extremely large stacked panel can be created by increasing the number of display panels 500. Furthermore, by changing the arrangement of the multiple display panels 500, the contour shape of the display section of the stacked panel can be made into various shapes, such as a non-rectangular shape, a circle, an ellipse, or a polygon. Furthermore, by arranging the display panels 500 three-dimensionally, a stacked panel having a display section with a three-dimensional shape, such as a cylindrical, spherical, or hemispherical shape, can be realized.

[0378] 28A is a cross-sectional view illustrating a structural example of a display panel 650 of one embodiment of the present invention. The display panel 650 can have a structure in which a display panel 600a and a display panel 600b are sandwiched between a substrate 601a and a substrate 601b, and an adhesive layer 619 is filled between the substrates.

[0379] The substrate 601a and the substrate 601b can be formed using a material similar to that which can be used for the substrate 253 and the substrate 106 described in Embodiment 2. The adhesive layer 619 can be formed using a material similar to that which can be used for the adhesive layer 255 described in Embodiment 2.

[0380] The display panel 600a and the display panel 600b may have the same configuration as the display device 100 shown in Figures 22 to 25. Similarly to the display panel 500, the display panel 600 preferably has flexibility.

[0381] 28B is an enlarged view of the configuration shown in FIG. 28A. As shown in FIG. 28B, the display panels 600a and 600b are bonded together by an adhesive layer 618 so that an edge of the display panel 600a and an edge of the display panel 600b overlap. Specifically, the display panels 600a and 600b are bonded together by the adhesive layer 618 so that an edge of the display portion of the display panel 600a and an edge of the display portion of the display panel 600b overlap. In other words, the display panel 650 can be configured by stacking the display panels 600a and 600b. The adhesive layer 618 can be made of the same material as the adhesive layer 619.

[0382] The display panel 650 can be configured to have a large size similar to the display panel 600 by stacking a plurality of display panels 600. The display panel 650 may also be configured to have three or more display panels 600 stacked one on top of the other. By increasing the number of display panels 600 included in the display panel 650, the display panel 650 can be made even larger.

[0383] At least a part of the configuration examples exemplified in this embodiment and the corresponding drawings can be combined as appropriate with other configuration examples or drawings.

[0384] This embodiment mode can be implemented by appropriately combining at least a part thereof with other embodiment modes described in this specification.

[0385] Embodiment 4 In this embodiment, a display device according to one embodiment of the present invention will be described.

[0386] A display device of one embodiment of the present invention includes a light-receiving element (also referred to as a light-receiving device) and a light-emitting element (also referred to as a light-emitting device). Alternatively, the display device of one embodiment of the present invention may include a light-receiving and light-emitting element (also referred to as a light-emitting and receiving device) and a light-emitting element.

[0387] First, a display device having a light receiving element and a light emitting element will be described.

[0388] 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 and light-emitting portion. In the display device according to one embodiment of the present invention, the light-emitting and receiving portion includes light-emitting elements arranged in a matrix, and an image can be displayed in the light-receiving and light-emitting portion. The light-receiving and light-emitting portion also includes light-receiving elements arranged in a matrix, and the light-receiving and light-emitting portion has one or both of an imaging function and a sensing function. The light-receiving and light-emitting portion can be used as an image sensor, a touch sensor, or the like. That is, by detecting light in the light-receiving and light-emitting portion, an image can be captured and a touch operation of an object (such as a finger or a pen) can be detected. Furthermore, the display device according to one embodiment of the present invention can utilize the light-emitting element as a light source for the sensor. Therefore, a light-receiving portion and a light source are not required separately from the display device, and the number of components in an electronic device can be reduced.

[0389] In a display device of one embodiment of the present invention, when light emitted by a light-emitting element included in the light-emitting and receiving portion is reflected (or scattered) by an object, the light-receiving element can detect the reflected light (or scattered light); therefore, imaging or detection of a touch operation, for example, is possible even in a dark place.

[0390] The light-emitting element included in the display device of one embodiment of the present invention functions as a display element (also referred to as a display device).

[0391] As the light-emitting element, it is preferable to use an EL element (also called an EL device) such as an OLED or a QLED. Examples of light-emitting materials that the EL element has include a fluorescent material, a phosphorescent material, an inorganic compound (e.g., a quantum dot material), and a material that exhibits thermally activated delayed fluorescence (thermally activated delayed fluorescence (TADF) material). Furthermore, an LED such as a micro LED can also be used as the light-emitting element.

[0392] A display device according to one embodiment of the present invention has a function of detecting light using a light-receiving element.

[0393] When the light receiving element is used as an image sensor, the display device can capture an image using the light receiving element, for example, the display device can be used as a scanner.

[0394] An electronic device to which the display device of one embodiment of the present invention is applied can acquire data related to biometric information such as a fingerprint or palm print by using a function as an image sensor. That is, a biometric authentication sensor can be built into the display device. The built-in biometric authentication sensor in the display device reduces the number of components in the electronic device compared to a case in which a biometric authentication sensor is provided separately from the display device, and the electronic device can be made smaller and lighter.

[0395] Furthermore, when the light receiving element is used as a touch sensor, the display device can detect a touch operation of an object using the light receiving element.

[0396] The light receiving element may be, for example, a pn-type or pin-type photodiode. The light receiving element functions as a photoelectric conversion element (also called a photoelectric conversion device) that detects light incident on the light receiving element and generates electric charge. The amount of electric charge generated by the light receiving element is determined based on the amount of light incident on the light receiving element.

[0397] In particular, it is preferable to use an organic photodiode having a layer containing an organic compound as the light-receiving element. Organic photodiodes can be easily made thin, lightweight, and large in area, and have a high degree of freedom in shape and design, making them applicable to a variety of devices.

[0398] In one embodiment of the present invention, an organic EL element (also referred to as 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 over the same substrate. Therefore, the organic photodiode can be built into a display device using the organic EL element.

[0399] If all layers constituting an organic EL element and an organic photodiode were to be fabricated separately, the number of film-forming steps would be enormous. However, since organic photodiodes have many layers that can be configured in common with organic EL elements, the number of film-forming steps can be reduced by forming the layers that can be configured in common at the same time.

[0400] For example, one of the pair of electrodes (common electrode) can be a layer common to the light-receiving element and the light-emitting element. Furthermore, for example, at least one of the hole injection layer, the hole transport layer, the electron transport layer, and the electron injection layer can be a layer common to the light-receiving element and the light-emitting element. By having a common layer for the light-receiving element and the light-emitting element in this way, the number of film formations and the number of masks can be reduced, thereby reducing the manufacturing process and manufacturing costs of the display device. Furthermore, a display device having a light-receiving element can be manufactured using existing manufacturing equipment and manufacturing methods for display devices.

[0401] Next, a display device having a light emitting / receiving element and a light emitting element will be described. Note that the description of the same functions, actions, effects, etc. as those described above may be omitted.

[0402] In a display device according to one embodiment of the present invention, a subpixel that exhibits one of the colors has a light-emitting / receiving element instead of a light-emitting element, and a subpixel that exhibits the other color has a light-emitting element. The light-emitting / receiving element has both a function of emitting light (light-emitting function) and a function of receiving light (light-receiving function). For example, when a pixel has three subpixels, i.e., a red subpixel, a green subpixel, and a blue subpixel, at least one subpixel has a light-emitting / receiving element, and the other subpixels have light-emitting elements. Therefore, the light-emitting / receiving portion of the display device according to one embodiment of the present invention has a function of displaying an image using both the light-emitting / receiving element and the light-emitting element.

[0403] Since the light-receiving and light-emitting element serves as both a light-emitting element and a light-receiving element, a pixel can be given a light-receiving function without increasing the number of subpixels included in the pixel. This allows one or both of an imaging function and a sensing function to be added to the light-receiving and light-emitting portion of the display device while maintaining the aperture ratio of the pixel (aperture ratio of each subpixel) and the resolution of the display device. Therefore, the display device of one embodiment of the present invention can have a higher pixel aperture ratio and can easily achieve higher resolution than a display device in which a subpixel having a light-receiving element is provided separately from a subpixel having a light-emitting element.

[0404] In a display device of one embodiment of the present invention, light-emitting and receiving elements and light-emitting elements are arranged in a matrix in a light-emitting and receiving portion, and an image can be displayed in the light-emitting and receiving portion. The light-emitting and receiving portion can be used as an image sensor, a touch sensor, or the like. In the display device of one embodiment of the present invention, the light-emitting element can be used as a light source for the sensor. Therefore, imaging or detection of a touch operation can be performed even in a dark place.

[0405] The light-emitting / receiving element can be fabricated by combining an organic EL element and an organic photodiode. For example, the light-emitting / receiving element can be fabricated by adding an active layer of an organic photodiode to the layered structure of the organic EL element. Furthermore, the light-emitting / receiving element fabricated by combining an organic EL element and an organic photodiode can suppress an increase in the number of film-forming steps by forming layers that can have a common configuration with the organic EL element in a single step.

[0406] For example, one of the pair of electrodes (common electrode) may be a layer common to the light-emitting and light-emitting elements. Also, for example, at least one of the hole injection layer, the hole transport layer, the electron transport layer, and the electron injection layer may be a layer common to the light-emitting and light-emitting elements.

[0407] Note that the layers of the light emitting / receiving element may have different functions depending on whether the light emitting / receiving element functions as a light receiving element or a light emitting element. In this specification, the components are referred to based on their functions when the light emitting / receiving element functions as a light emitting element.

[0408] The display device of this embodiment mode has a function of displaying an image using a light-emitting element and a light-emitting / light-emitting element. That is, the light-emitting element and the light-emitting / light-emitting element function as display elements.

[0409] The display device of this embodiment has a function of detecting light using a light receiving and emitting element, which can detect light having a shorter wavelength than light emitted by the light receiving and emitting element itself.

[0410] When the light-emitting / receiving elements are used as an image sensor, the display device of this embodiment can capture an image using the light-emitting / receiving elements. When the light-emitting / receiving elements are used as a touch sensor, the display device of this embodiment can detect a touch operation of an object using the light-emitting / receiving elements.

[0411] The light-receiving / light-emitting element functions as a photoelectric conversion element. The light-receiving / light-emitting element can be fabricated by adding an active layer of a light-receiving element to the configuration of the light-emitting element. For example, the active layer of a pn-type or pin-type photodiode can be used for the light-receiving / light-emitting element.

[0412] In particular, it is preferable to use an organic photodiode active layer having a layer containing an organic compound as the light-receiving / light-emitting element. Organic photodiodes can be easily made thin, lightweight, and large in area, and have a high degree of freedom in shape and design, making them applicable to a variety of devices.

[0413] A display device, which is an example of a display device according to one embodiment of the present invention, will be described in more detail below with reference to drawings.

[0414] 29A is a schematic diagram of a display panel 200. The display panel 200 includes a substrate 207, a substrate 202, a light receiving element 212, a light emitting element 216R, a light emitting element 216G, a light emitting element 216B, a functional layer 203, and the like.

[0415] The light-emitting elements 216R, 216G, 216B, and light-receiving element 212 are provided between the substrate 207 and the substrate 202. The light-emitting elements 216R, 216G, and 216B emit red (R), green (G), and blue (B) light, respectively. Note that hereinafter, when there is no need to distinguish between the light-emitting elements 216R, 216G, and 216B, they may be referred to as light-emitting elements 216.

[0416] The display panel 200 has a plurality of pixels arranged in a matrix. Each pixel has one or more sub-pixels. Each sub-pixel has one light-emitting element. For example, a pixel may have three sub-pixels (e.g., three colors of R, G, and B, or three colors of yellow (Y), cyan (C), and magenta (M)), or four sub-pixels (e.g., four colors of R, G, B, and white (W), or four colors of R, G, B, and Y). Each pixel also has a light-receiving element 212. The light-receiving element 212 may be provided in all pixels or in some pixels. Alternatively, one pixel may have multiple light-receiving elements 212.

[0417] 29A shows a state in which a finger 220 touches the surface of the substrate 202. A portion of the light emitted by the light-emitting element 216G is reflected at the contact point between the substrate 202 and the finger 220. A portion of the reflected light is then incident on the light-receiving element 212, thereby making it possible to detect that the finger 220 has touched the substrate 202. In other words, the display panel 200 can function as a touch sensor.

[0418] The functional layer 203 has a circuit for driving the light-emitting element 216R, the light-emitting element 216G, and the light-emitting element 216B, and a circuit for driving the light-receiving element 212. The functional layer 203 is provided with a switch, a transistor, a capacitor, a wiring, or the like. Note that when the light-emitting element 216R, the light-emitting element 216G, the light-emitting element 216B, and the light-receiving element 212 are driven by a passive matrix method, a configuration may be adopted in which a switch, a transistor, or the like is not provided.

[0419] The display panel 200 preferably has a function for detecting the fingerprint of a finger 220. Fig. 29B is a schematic enlarged view of a contact portion when the finger 220 is in contact with the substrate 202. Fig. 29B also shows light-emitting elements 216 and light-receiving elements 212 arranged alternately.

[0420] A fingerprint is formed on finger 220 by recesses and protrusions, and therefore the protrusions of the fingerprint are in contact with substrate 202 as shown in FIG.

[0421] Light reflected from a surface or interface can be classified as specular reflection or diffuse reflection. Specular reflection is highly directional light, with the angle of incidence and the angle of reflection matching, while diffuse reflection is low-directional light, with low angular dependence of intensity. The diffuse reflection component is dominant in the light reflected from the surface of the finger 220. On the other hand, the specular reflection component is dominant in the light reflected from the interface between the substrate 202 and the atmosphere.

[0422] The intensity of light reflected by the contact or non-contact surface between the finger 220 and the substrate 202 and incident on the light receiving element 212 located directly below them is the sum of specularly reflected light and diffusely reflected light. As described above, at the concave portions of the finger 220, the substrate 202 and the finger 220 do not come into contact, so specularly reflected light (indicated by the solid arrows) is dominant, whereas at the convex portions, they come into contact, so diffusely reflected light (indicated by the dashed arrows) from the finger 220 is dominant. Therefore, the intensity of light received by the light receiving element 212 located directly below the concave portions is higher than that of the light receiving element 212 located directly below the convex portions. This makes it possible to capture an image of the fingerprint of the finger 220.

[0423] A clear fingerprint image can be obtained by arranging the light receiving elements 212 at an interval smaller than the distance between two convex portions of a fingerprint, preferably the distance between adjacent convex and concave portions. Since the distance between convex and concave portions of a human fingerprint is approximately 200 μm, the interval between the light receiving elements 212 is, for example, 400 μm or less, preferably 200 μm or less, more preferably 150 μm or less, even more preferably 100 μm or less, and even more preferably 50 μm or less, and is 1 μm or more, preferably 10 μm or more, and more preferably 20 μm or more.

[0424] Fig. 29C shows an example of a fingerprint image captured by display panel 200. In Fig. 29C, the outline of finger 220 is indicated by a dashed line and the outline of contact portion 227 is indicated by a dashed line within imaging range 228. Within contact portion 227, a fingerprint 222 with high contrast can be captured due to differences in the amount of light incident on light receiving element 212.

[0425] The display panel 200 can also function as a touch sensor or a pen tablet. Fig. 29D shows a state in which the tip of a stylus 229 is in contact with the substrate 202 and is slid in the direction of the dashed arrow.

[0426] As shown in Figure 29D, the diffused reflected light scattered by the tip of the stylus 229 and the contact surface of the substrate 202 is incident on the light receiving element 212 located at the part overlapping with the contact surface, thereby enabling the position of the tip of the stylus 229 to be detected with high accuracy.

[0427] 29E shows an example of a trajectory 226 of the stylus 229 detected by the display panel 200. The display panel 200 is capable of detecting the position of a detectable object such as the stylus 229 with high positional accuracy, and therefore is also capable of performing high-resolution drawing in, for example, a drawing application. Furthermore, unlike the case where a capacitive touch sensor or an electromagnetic induction touch pen is used, the position of even a highly insulating detectable object can be detected, and therefore the material of the tip of the stylus 229 is not a factor, and various writing implements (e.g., a brush, a glass pen, a feather pen, etc.) can be used.

[0428] 29F to 29H show an example of a pixel that can be applied to the display panel 200. FIG.

[0429] 29F and 29G each have a red (R) light-emitting element 216R, a green (G) light-emitting element 216G, a blue (B) light-emitting element 216B, and a light-receiving element 212. The pixel has a pixel circuit for driving the light-emitting element 216R, the light-emitting element 216G, the light-emitting element 216B, and the light-receiving element 212, respectively.

[0430] Fig. 29F shows an example in which three light-emitting elements and one light-receiving element are arranged in a 2 x 2 matrix, while Fig. 29G shows an example in which three light-emitting elements are arranged in a row, with one horizontally long light-receiving element 212 arranged below them.

[0431] 29H is an example of a pixel having a white (W) light-emitting element 216W. Here, four light-emitting elements are arranged in a row, and a light-receiving element 212 is arranged below them.

[0432] The pixel configuration is not limited to the above, and various arrangement methods can be adopted.

[0433] [Configuration Example 2] Hereinafter, an example of a configuration including a light-emitting element that emits visible light, a light-emitting element that emits infrared light, and a light-receiving element will be described.

[0434] The display panel 200A shown in Fig. 30A has a light-emitting element 216IR in addition to the configuration exemplified in Fig. 29A. The light-emitting element 216IR is a light-emitting element that emits infrared light IR. In this case, it is preferable to use an element that can receive at least the infrared light IR emitted by the light-emitting element 216IR as the light-receiving element 212. It is more preferable to use an element that can receive both visible light and infrared light as the light-receiving element 212.

[0435] As shown in FIG. 30A, when a finger 220 touches the substrate 202, the infrared light IR emitted from the light-emitting element 216IR is reflected by the finger 220, and a portion of the reflected light is incident on the light-receiving element 212, thereby obtaining position information of the finger 220.

[0436] 30B to 30D show examples of pixels that can be applied to the display panel 200A.

[0437] Fig. 30B shows an example in which three light-emitting elements are arranged in a row, and below them, light-emitting element 216IR and light-receiving element 212 are arranged side by side. Fig. 30C shows an example in which four light-emitting elements including light-emitting element 216IR are arranged in a row, and below them, light-receiving element 212 is arranged.

[0438] FIG. 30D shows an example in which three light-emitting elements and a light-receiving element 212 are arranged on all four sides with the light-emitting element 216IR at the center.

[0439] In the pixels shown in FIGS. 30B to 30D, the positions of the light-emitting elements and the light-receiving elements can be interchanged.

[0440] Configuration Example 3 Hereinafter, an example of a configuration including a light-emitting element that emits visible light and a light-receiving / light-emitting element that emits visible light and receives visible light will be described.

[0441] The display panel 200B shown in Figure 31A has a light-emitting element 216B, a light-emitting element 216G, and a light-receiving / light-emitting element 213R. The light-receiving / 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. Figure 31A shows an example in which the light-receiving / light-emitting element 213R receives green (G) light emitted by the light-emitting element 216G. The light-receiving / light-emitting element 213R may also receive blue (B) light emitted by the light-emitting element 216B. The light-receiving / light-emitting element 213R may also receive both green light and blue light.

[0442] For example, it is preferable that the light receiving / emitting element 213R receives light with a shorter wavelength than the light it emits. Alternatively, the light receiving / emitting element 213R may be configured to receive light with a longer wavelength than the light it emits (e.g., infrared light). The light receiving / emitting element 213R may be configured to receive light with a wavelength similar to the light it emits, but in that case, it may also receive the light it emits, which could reduce the light emission efficiency. Therefore, it is preferable that the light receiving / emitting element 213R is configured so that the peak of the emission spectrum and the peak of the absorption spectrum do not overlap as much as possible.

[0443] In addition, the light emitted by the light emitting / receiving element is not limited to red light. Furthermore, the light emitted by the light emitting element is not limited to a combination of green light and blue light. For example, the light emitting / receiving element may be an element that emits green or blue light and receives light of a wavelength different from the light it emits.

[0444] In this way, the light emitting / receiving element 213R functions as both a light emitting element and a light receiving element, so that the number of elements arranged in one pixel can be reduced, which facilitates higher definition, a higher aperture ratio, and higher resolution.

[0445] 31B to 31I show an example of a pixel that can be applied to the display panel 200B.

[0446] Fig. 31B shows an example in which the light emitting / receiving element 213R, the light emitting element 216G, and the light emitting element 216B are arranged in a row. Fig. 31C shows an example in which the light emitting element 216G and the light emitting element 216B are arranged alternately in the vertical direction, and the light emitting / receiving element 213R is arranged next to them.

[0447] FIG. 31D shows an example in which three light-emitting elements (light-emitting element 216G, light-emitting element 216B, and light-emitting element 216X) and one light-receiving / light-emitting element are arranged in a 2×2 matrix. Light-emitting element 216X 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 light (IR), and ultraviolet light (UV). When light-emitting element 216X emits infrared light, it is preferable that the light-receiving / light-emitting element has a function of detecting infrared light or a function of detecting both visible light and infrared light. The wavelength of light detected by the light-receiving / light-emitting element can be determined depending on the application of the sensor.

[0448] FIG. 31E shows two pixels. An area including three elements surrounded by dotted lines corresponds to one pixel. Each pixel has a light-emitting element 216G, a light-emitting element 216B, and an optical element 213R. In the left pixel shown in FIG. 31E, the light-emitting element 216G is arranged in the same row as the optical element 213R, and the light-emitting element 216B is arranged in the same column as the optical element 213R. In the right pixel shown in FIG. 31E, the light-emitting element 216G is arranged in the same row as the optical element 213R, and the light-emitting element 216B is arranged in the same column as the optical element 216G. In the pixel layout shown in FIG. 31E, the optical element 213R, the light-emitting element 216G, and the light-emitting element 216B are arranged repeatedly in both odd and even rows, and in each column, light-emitting and optical element 213R, the light-emitting element 216G, and the light-emitting element 216B are arranged alternately in both odd and even rows, and ... in each column, light-emitting elements or optical element 213R of different colors are arranged in the odd and even rows.

[0449] Figure 31F shows four pixels to which the Pentile arrangement is applied, with two adjacent pixels having light-emitting or light-receiving elements that emit light of two different colors. Note that Figure 31F shows the top view of the light-emitting or light-receiving elements.

[0450] The upper left pixel and lower right pixel shown in Fig. 31F have a light emitting / receiving element 213R and a light emitting element 216G. The upper right pixel and lower left pixel have a light emitting element 216G and a light emitting element 216B. That is, in the example shown in Fig. 31F, a light emitting element 216G is provided in each pixel.

[0451] The top surface shapes of the light-emitting element and the light-receiving / light-emitting element are not particularly limited and may be circular, elliptical, polygonal, polygonal with rounded corners, etc. For example, Fig. 31F shows an example in which the top surface shapes of the light-emitting element and the light-receiving / light-emitting element are squares (diamonds) tilted at approximately 45 degrees. Note that the top surface shapes of the light-emitting element and the light-receiving / light-emitting element for each color may be different from each other, or may be the same for some or all of the colors.

[0452] In addition, the sizes of the light-emitting regions (or light-receiving regions) of the light-emitting elements and light-receiving / light-emitting elements of each color may be different from each other, or may be the same for some or all of the colors. For example, in Figure 31F, the area of ​​the light-emitting region of the light-emitting element 216G provided in each pixel may be smaller than the light-emitting regions (or light-receiving / light-emitting regions) of the other elements.

[0453] Fig. 31G is a modified example of the pixel array shown in Fig. 31F. Specifically, the configuration in Fig. 31G is obtained by rotating the configuration in Fig. 31F by 45 degrees. Although Fig. 31F has been described as having two elements per pixel, it can also be understood that one pixel is made up of four elements, as shown in Fig. 31G.

[0454] Fig. 31H is a modified example of the pixel array shown in Fig. 31F. The upper left pixel and lower right pixel shown in Fig. 31H have light-emitting / receiving elements 213R and light-emitting elements 216G. The upper right pixel and lower left pixel have light-emitting / receiving elements 213R and light-emitting elements 216B. That is, in the example shown in Fig. 31H, each pixel is provided with a light-emitting / receiving element 213R. Because each pixel is provided with a light-emitting / receiving element 213R, the configuration shown in Fig. 31H can capture images with higher resolution than the configuration shown in Fig. 31F. This can improve the accuracy of biometric authentication, for example.

[0455] FIG. 31I is a modified example of the pixel array shown in FIG. 31H, and is a configuration obtained by rotating the pixel array by 45 degrees.

[0456] In Figure 31I, we will explain that one pixel is composed of four elements (two light-emitting elements and two light-receiving and light-emitting elements). In this way, one pixel has multiple light-receiving and light-emitting elements with light-receiving functions, allowing for high-resolution imaging. This can improve the accuracy of biometric authentication. For example, the imaging resolution can be set to the root double of the display resolution.

[0457] A display device to which the configuration shown in Figure 31H or 31I is applied has p (p is an integer greater than or equal to 2) first light-emitting elements, q (q is an integer greater than or equal to 2) second light-emitting elements, and r (r is an integer greater than p and greater than q) light-receiving and light-emitting elements. p and r satisfy r = 2p. Furthermore, p, q, and r satisfy r = p + q. One of the first light-emitting elements and the second light-emitting element emits green light, and the other emits blue light. The light-receiving and light-emitting element emits red light and has a light-receiving function.

[0458] For example, when detecting a touch operation using a light-emitting / receiving element, it is preferable that the light emitted from the light source is less visible to the user. Because blue light is less visible than green light, it is preferable that a light-emitting element that emits blue light be used as the light source. Therefore, it is preferable that the light-emitting / receiving element has a function of receiving blue light. However, this is not limited to this, and the light-emitting element used as the light source can be appropriately selected depending on the sensitivity of the light-emitting / receiving element.

[0459] As described above, pixels with various arrangements can be applied to the display device of this embodiment mode.

[0460] At least a part of the configuration examples exemplified in this embodiment and the corresponding drawings can be combined as appropriate with other configuration examples or drawings.

[0461] This embodiment mode can be implemented by appropriately combining at least a part thereof with other embodiment modes described in this specification.

[0462] Embodiment 5 In this embodiment, 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) that can be used for a light-emitting and receiving device that is one embodiment of the present invention will be described.

[0463] In this specification and the like, a structure in which different light-emitting layers are formed or different light-emitting layers are painted for each color light-emitting device (here, blue (B), green (G), and red (R)) may be referred to as an SBS (Side By Side) structure. In this specification and the like, a light-emitting device that can emit white light may be referred to as a white light-emitting device. In addition, a white light-emitting device can be combined with a colored layer (for example, a color filter) to realize a full-color display device.

[0464] Furthermore, light-emitting devices can be broadly divided into single structures and tandem structures. A single-structure device has one light-emitting unit between a pair of electrodes, and the light-emitting unit preferably includes one or more light-emitting layers. When two light-emitting layers are used to obtain white light emission, light-emitting layers can be selected such that the emission colors of the two light-emitting layers are complementary to each other. For example, by making the emission color of the first light-emitting layer and the emission color of the second light-emitting layer complementary to each other, a configuration in which the light-emitting device as a whole emits white light can be obtained. When three or more light-emitting layers are used to obtain white light emission, the emission colors of the three or more light-emitting layers can be combined to produce a configuration in which the light-emitting device as a whole emits white light.

[0465] A tandem-structure device preferably has two or more light-emitting units between a pair of electrodes, and each light-emitting unit preferably includes one or more light-emitting layers. By using light-emitting layers that emit light of the same color in each light-emitting unit, the luminance per given current can be increased, and the device can be made more reliable than a single-structure light-emitting device. To obtain white light emission in a tandem structure, the device can be configured to combine light from the light-emitting layers of multiple light-emitting units to obtain white light. The combination of light-emitting colors that can produce white light is the same as in the single-structure configuration. In a tandem-structure device, it is preferable to provide an intermediate layer, such as a charge-generating layer, between the multiple light-emitting units.

[0466] Furthermore, when the above-described white light-emitting device (single structure or tandem structure) is compared with a light-emitting device having an SBS structure, the light-emitting device having an SBS structure can reduce power consumption compared to the white light-emitting device. When it is desired to reduce power consumption, it is preferable to use a light-emitting device having an SBS structure. On the other hand, the manufacturing process of a white light-emitting device is simpler than that of a light-emitting device having an SBS structure, and therefore the manufacturing cost can be reduced or the manufacturing yield can be increased, making it preferable.

[0467] [Device Structure] Next, detailed structures of a light-emitting element, a light-receiving element, and a light-emitting and light-emitting element that can be used in the display device of one embodiment of the present invention will be described.

[0468] The display device of one embodiment of the present invention may be any of a top emission type that emits light in a direction opposite to a substrate on which a light-emitting element is formed, a bottom emission type that emits light toward a substrate on which a light-emitting element is formed, and a dual emission type that emits light to both sides.

[0469] In this embodiment, a top-emission display device will be described as an example.

[0470] In this specification and the like, unless otherwise specified, even when describing a configuration having a plurality of elements (e.g., light-emitting elements or light-emitting layers), when describing matters common to each element, the alphabet will be omitted. For example, when describing matters common to light-emitting layer 383R and light-emitting layer 383G, the light-emitting layer may be referred to as light-emitting layer 383.

[0471] The display device 380A shown in Figure 32A has 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.

[0472] Each light-emitting element has 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 stacked in this order. The light-emitting element 370R has a light-emitting layer 383R, the light-emitting element 370G has a light-emitting layer 383G, and the light-emitting element 370B has a light-emitting layer 383B. The light-emitting layer 383R contains a light-emitting material that emits red light, the light-emitting layer 383G contains a light-emitting material that emits green light, and the light-emitting layer 383B contains a light-emitting material that emits blue light.

[0473] The light emitting element is an electroluminescent element that emits light toward the common electrode 375 when a voltage is applied between the pixel electrode 371 and the common electrode 375 .

[0474] The light receiving element 370PD has 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 stacked in this order.

[0475] The light receiving element 370PD is a photoelectric conversion element that receives light incident from outside the display device 380A and converts it into an electrical signal.

[0476] In this embodiment, in both the light-emitting element and the light-receiving element, the pixel electrode 371 functions as an anode and the common electrode 375 functions as a cathode. In other words, the light-receiving element is driven by applying a reverse bias between the pixel electrode 371 and the common electrode 375, so that the light incident on the light-receiving element can be detected, an electric charge can be generated, and the electric charge can be extracted as a current.

[0477] In the display device of this embodiment, an organic compound is used for the active layer 373 of the light-receiving element 370PD. The layers of the light-receiving element 370PD other than the active layer 373 can be configured in common with the light-emitting element. Therefore, by simply adding a step of forming the active layer 373 to the manufacturing process of the light-emitting element, the light-receiving element 370PD can be formed in parallel 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 built into the display device without significantly increasing the number of manufacturing steps.

[0478] The display device 380A shows an example in which the light receiving element 370PD and the light emitting element have a common configuration, except that the active layer 373 of the light receiving element 370PD and the light emitting layer 383 of the light emitting element are fabricated separately. However, the configuration of the light receiving element 370PD and the light emitting element is not limited to this. The light receiving element 370PD and the light emitting element may have layers fabricated separately from each other, in addition to the active layer 373 and the light emitting layer 383. It is preferable that the light receiving element 370PD and the light emitting element have one or more layers used in common (common layers). This allows the light receiving element 370PD to be incorporated into the display device without significantly increasing the number of manufacturing steps.

[0479] A conductive film that transmits visible light is used for the electrode from which light is extracted, either the pixel electrode 371 or the common electrode 375. It is preferable to use a conductive film that reflects visible light for the electrode from which light is not extracted.

[0480] The light-emitting element has at least a light-emitting layer 383. The light-emitting element may further have, as a layer other than the light-emitting layer 383, a layer containing a substance having a high hole-injecting property, a substance having a high hole-transporting property, a hole-blocking material, a substance having a high electron-transporting property, a substance having a high electron-injecting property, a bipolar substance (a substance having a high electron-transporting property and a high hole-transporting property), or the like.

[0481] For example, the light-emitting element and the light-receiving element may have one or more layers of the hole injection layer, hole transport layer, electron transport layer, and electron injection layer in common, or the light-emitting element and the light-receiving element may have one or more layers of the hole injection layer, hole transport layer, electron transport layer, and electron injection layer formed differently from each other.

[0482] The hole injection layer is a layer that injects holes from the anode into the light-emitting element and contains a material with high hole injection properties, such as an aromatic amine compound or a composite material containing a hole transport material and an acceptor material (electron acceptor material).

[0483] In a light-emitting element, the hole transport layer is a layer that transports holes injected from the anode by the hole injection layer to the light-emitting layer. In a light-receiving element, the hole transport layer is a layer that transports holes generated in the active layer based on incident light to the anode. The hole transport layer is a layer that contains a hole transport material. The hole transport material is a material having a concentration of 1×10 −６ cm ２ A substance having a hole mobility of 1 / Vs or more is preferred. Note that other substances can also be used as long as they have a higher hole transporting property than electron transporting property. As the hole transporting material, a material having a high hole transporting property, such as a π-electron-rich heteroaromatic compound (e.g., a carbazole derivative, a thiophene derivative, or a furan derivative), or an aromatic amine (a compound having an aromatic amine skeleton), is preferred.

[0484] In a light-emitting element, the electron transport layer is a layer that transports electrons injected from the cathode by the electron injection layer to the light-emitting layer. In a light-receiving element, the electron transport layer is a layer that transports electrons generated in the active layer based on incident light to the cathode. The electron transport layer is a layer that contains an electron transporting material. The electron transporting material is a material having a 1×10 −６ cm ２ / Vs or more is preferred. Note that other materials can also be used as long as they have a higher electron transporting property than holes. Examples of the electron-transporting material include metal complexes having a quinoline skeleton, metal complexes having a benzoquinoline skeleton, metal complexes having an oxazole skeleton, and metal complexes having a thiazole skeleton, as well as oxadiazole derivatives, triazole derivatives, imidazole derivatives, oxazole derivatives, thiazole derivatives, phenanthroline derivatives, quinoline derivatives having a quinoline ligand, benzoquinoline derivatives, quinoxaline derivatives, dibenzoquinoxaline derivatives, pyridine derivatives, bipyridine derivatives, pyrimidine derivatives, and other π-electron-deficient heteroaromatic compounds including nitrogen-containing heteroaromatic compounds.

[0485] The electron injection layer is a layer that injects electrons from the cathode to the light-emitting element and contains a material with high electron injection properties. Examples of the material with high electron injection properties include alkali metals, alkaline earth metals, and compounds thereof. Examples of the material with high electron injection properties include a composite material containing an electron transport material and a donor material (electron donor material).

[0486] The light-emitting layer 383 is a layer containing a light-emitting substance. The light-emitting layer 383 can contain one or more light-emitting substances. As the light-emitting substance, a substance that emits light of blue, purple, blue-purple, green, yellow-green, yellow, orange, red, or the like is appropriately used. Furthermore, as the light-emitting substance, a substance that emits near-infrared light can also be used.

[0487] Examples of the light-emitting material include fluorescent materials, phosphorescent materials, TADF materials, and quantum dot materials.

[0488] Examples of fluorescent materials include pyrene derivatives, anthracene derivatives, triphenylene derivatives, fluorene derivatives, carbazole derivatives, dibenzothiophene derivatives, dibenzofuran derivatives, dibenzoquinoxaline derivatives, quinoxaline derivatives, pyridine derivatives, pyrimidine derivatives, phenanthrene derivatives, and naphthalene derivatives.

[0489] Examples of phosphorescent materials include organometallic complexes (particularly 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 (particularly iridium complexes) having a phenylpyridine derivative having an electron-withdrawing group as a ligand; platinum complexes; and rare earth metal complexes.

[0490] The light-emitting layer 383 may contain one or more organic compounds (host materials, assist materials, etc.) in addition to a light-emitting substance (guest material). As the one or more organic compounds, one or both of a hole-transporting material and an electron-transporting material can be used. Furthermore, as the one or more organic compounds, a bipolar material or a TADF material can be used.

[0491] The light-emitting layer 383 preferably includes, for example, a phosphorescent material and a hole-transporting material and an electron-transporting material, which are a combination that easily forms an exciplex. With this structure, light emission can be efficiently obtained using Exciplex-Triple Energy Transfer (ExTET), which is energy transfer from an exciplex to a light-emitting substance (phosphorescent material). By selecting a combination that forms an exciplex that emits light that overlaps with the wavelength of the lowest-energy absorption band of the light-emitting substance, energy transfer becomes smooth, allowing light emission to be obtained efficiently. With this structure, high efficiency, low-voltage operation, and a long lifetime of the light-emitting element can be simultaneously achieved.

[0492] As a combination of materials that form an exciplex, it is preferable that the HOMO level (highest occupied molecular orbital level) of the hole transporting material is equal to or higher than the HOMO level of the electron transporting material. It is also preferable that the LUMO level (lowest unoccupied molecular orbital level) of the hole transporting material is equal to or higher than the LUMO level of the electron transporting material. The LUMO level and HOMO level of the material can be derived from the electrochemical properties (reduction potential and oxidation potential) of the material measured by cyclic voltammetry (CV).

[0493] The formation of exciplexes can be confirmed, for example, by comparing the emission spectra of the hole-transporting material, the electron-transporting material, and a mixed film obtained by mixing these materials, and observing the phenomenon in which the emission spectrum of the mixed film is shifted to longer wavelengths than the emission spectra of each material (or has a new peak on the longer wavelength side). Alternatively, it can be confirmed by comparing the transient photoluminescence (PL) of the hole-transporting material, the transient PL of the electron-transporting material, and a mixed film obtained by mixing these materials, and observing differences in transient response, such as the transient PL lifetime of the mixed film having a longer-lifetime component or a larger proportion of delayed components than the transient PL lifetimes of the individual materials. The above-mentioned transient PL may also be interpreted as transient electroluminescence (EL). That is, the formation of exciplexes can also be confirmed by comparing the transient EL of the hole-transporting material, the transient EL of the electron-transporting material, and a mixed film obtained by mixing these materials, and observing the differences in transient response.

[0494] The active layer 373 includes a semiconductor. Examples of the semiconductor include an inorganic semiconductor such as silicon and an organic semiconductor including an organic compound. In this embodiment, an example in which an organic semiconductor is used as the semiconductor included in the active layer 373 is shown. By using an organic semiconductor, the light-emitting layer 383 and the active layer 373 can be formed by the same method (for example, vacuum deposition), which is preferable because a common manufacturing device can be used.

[0495] The active layer 373 has an n-type semiconductor material, such as fullerene (e.g., C ６０ Fullerene and C ７０Examples of suitable electron-accepting organic semiconductor materials include fullerenes, such as fullerene derivatives, and fullerenes with electron-accepting properties. Fullerenes have a soccer ball-like shape, which is energetically stable. Fullerenes have deep (low) HOMO and LUMO levels. Because fullerenes have a deep LUMO level, they have extremely high electron-accepting properties (acceptor properties). Normally, when π-electron conjugation (resonance) spreads across a plane, as in benzene, electron-donating properties (donor properties) become high, but fullerenes have a spherical shape, so they have high electron-accepting properties despite their π-electron conjugation. High electron-accepting properties allow charge separation to occur quickly and efficiently, making them useful as light-receiving elements. C ６０ , C ７０ Both have a wide absorption band in the visible light region, and C ７０ is C ６０ Other fullerene derivatives include [6,6]-Phenyl-C71-butylic acid methyl ester (abbreviation: PC70BM), [6,6]-Phenyl-C61-butylic acid methyl ester (abbreviation: PC60BM), and 1',1",4',4"-Tetrahydro-di[1,4]methanenaphthaleno[1,2:2',3',56,60:2",3"][5,6]fullerene-C60 (abbreviation: ICBA).

[0496] Furthermore, examples of materials for n-type semiconductors include perylene tetracarboxylic acid derivatives such as N,N'-dimethyl-3,4,9,10-perylene tetracarboxylic acid diimide (abbreviation: Me-PTCDI).

[0497] An example of an n-type semiconductor material is 2,2'-(5,5'-(thieno[3,2-b]thiophene-2,5-diyl)bis(thiophene-5,2-diyl))bis(methane-1-yl-1-ylidene)dimalononitrile (abbreviation: FT2TDMN).

[0498] Examples of n-type semiconductor materials include metal complexes having a quinoline skeleton, metal complexes having a benzoquinoline skeleton, metal complexes having an oxazole skeleton, metal complexes having a thiazole skeleton, oxadiazole derivatives, triazole derivatives, imidazole derivatives, oxazole derivatives, thiazole derivatives, phenanthroline derivatives, quinoline derivatives, benzoquinoline derivatives, quinoxaline derivatives, dibenzoquinoxaline derivatives, pyridine derivatives, bipyridine derivatives, pyrimidine derivatives, naphthalene derivatives, anthracene derivatives, coumarin derivatives, rhodamine derivatives, triazine derivatives, and quinone derivatives.

[0499] Examples of the p-type semiconductor material of the active layer 373 include electron-donating organic semiconductor materials such as copper(II) phthalocyanine (CuPc), tetraphenyldibenzoperiflanthene (DBP), zinc phthalocyanine (ZnPc), tin(II) phthalocyanine (SnPc), quinacridone, and rubrene.

[0500] Examples of p-type semiconductor materials include carbazole derivatives, thiophene derivatives, furan derivatives, and compounds having an aromatic amine skeleton. Examples of p-type semiconductor materials include naphthalene derivatives, anthracene derivatives, pyrene derivatives, triphenylene derivatives, fluorene derivatives, pyrrole derivatives, benzofuran derivatives, benzothiophene derivatives, indole derivatives, dibenzofuran derivatives, dibenzothiophene derivatives, indolocarbazole derivatives, porphyrin derivatives, phthalocyanine derivatives, naphthalocyanine derivatives, quinacridone derivatives, rubrene derivatives, tetracene derivatives, polyphenylenevinylene derivatives, polyparaphenylene derivatives, polyfluorene derivatives, polyvinylcarbazole derivatives, and polythiophene derivatives.

[0501] The HOMO level of the electron-donating organic semiconductor material is preferably shallower (higher) than the HOMO level of the electron-accepting organic semiconductor material, and the LUMO level of the electron-donating organic semiconductor material is preferably shallower (higher) than the LUMO level of the electron-accepting organic semiconductor material.

[0502] It is preferable to use a spherical fullerene as the electron-accepting organic semiconductor material and a planar organic semiconductor material as the electron-donating organic semiconductor material. Molecules with similar shapes tend to aggregate together, and when molecules of the same type aggregate, the energy levels of their molecular orbitals become close, which can improve carrier transport properties.

[0503] For example, the active layer 373 is preferably formed by co-evaporating an n-type semiconductor and a p-type semiconductor, or alternatively, the active layer 373 may be formed by laminating an n-type semiconductor and a p-type semiconductor.

[0504] The light-emitting element and the light-receiving element can be made of either a low-molecular-weight compound or a high-molecular-weight compound, and may contain an inorganic compound. The layers constituting the light-emitting element and the light-receiving element can be formed by a method such as a vapor deposition method (including a vacuum vapor deposition method), a transfer method, a printing method, an inkjet method, or a coating method.

[0505] For example, the hole transport material or electron blocking material may be a polymer compound such as poly(3,4-ethylenedioxythiophene) / poly(styrenesulfonic acid) (PEDOT / PSS), or an inorganic compound such as molybdenum oxide or copper iodide (CuI). Alternatively, the electron transport material or hole blocking material may be an inorganic compound such as zinc oxide (ZnO), or an organic compound such as polyethyleneimine ethoxylate (PEIE). The light-receiving device may have, for example, a mixed film of PEIE and ZnO.

[0506] Furthermore, a polymer compound such as Poly[[4,8-bis[5-(2-ethylhexyl)-2-thienyl]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]] polymer (abbreviation: PBDB-T) or a PBDB-T derivative, which functions as a donor, can be used for the active layer 373. For example, a method of dispersing an acceptor material in PBDB-T or a PBDB-T derivative can be used.

[0507] A display device 380B shown in FIG. 32B differs from display device 380A in that a light receiving element 370PD and a light emitting element 370R have the same configuration.

[0508] The light receiving element 370PD and the light emitting element 370R have in common an active layer 373 and a light emitting layer 383R.

[0509] Here, it is preferable that the light receiving element 370PD has the same configuration as a light emitting element that emits light of a longer wavelength than the light to be detected. For example, the light receiving element 370PD configured to detect blue light can have the same configuration as one or both of the light emitting element 370R and the light emitting element 370G. For example, the light receiving element 370PD configured to detect green light can have the same configuration as the light emitting element 370R.

[0510] By using a common structure for the light-receiving element 370PD and the light-emitting element 370R, the number of film-forming steps and the number of masks can be reduced compared to a structure in which the light-receiving element 370PD and the light-emitting element 370R have separate layers, thereby reducing the manufacturing steps and manufacturing costs of the display device.

[0511] Furthermore, by using a common configuration for the light receiving element 370PD and the light emitting element 370R, the margin for misalignment can be narrowed compared to a configuration in which the light receiving element 370PD and the light emitting element 370R have separate layers. This allows the pixel aperture ratio to be increased, and the light extraction efficiency of the display device to be improved. This also allows the life of the light emitting element to be extended. Furthermore, the display device can display high brightness. Furthermore, it is possible to increase the resolution of the display device.

[0512] 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 red (for example, one or both of green light and blue light). The active layer 373 preferably contains an organic compound that does not easily absorb red light and absorbs light with a wavelength shorter than red. This allows red light to be extracted efficiently from the light-emitting element 370R, and the light-receiving element 370PD to detect light with a wavelength shorter than red with high accuracy.

[0513] Furthermore, in the display device 380B, an example is shown in which the light emitting element 370R and the light receiving element 370PD have the same configuration, but the light emitting element 370R and the light receiving element 370PD may have optical adjustment layers of different thicknesses.

[0514] 33A and 33B includes a light receiving / emitting 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 configuration of light emitting element 370G and light emitting element 370B can be, for example, that of display device 380A.

[0515] The light emitting / receiving element 370SR has 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 stacked in this order. The light emitting / receiving element 370SR has the same configuration as the light emitting element 370R and the light receiving element 370PD exemplified in the display device 380B.

[0516] Fig. 33A shows a case where the light emitting / receiving element 370SR functions as a light emitting element. Fig. 33A shows an example where the light emitting element 370B emits blue light, the light emitting element 370G emits green light, and the light emitting / receiving element 370SR emits red light.

[0517] Fig. 33B shows a case where the light receiving / emitting element 370SR functions as a light receiving element, in which the light receiving / emitting element 370SR receives blue light emitted by the light emitting element 370B and green light emitted by the light emitting element 370G.

[0518] The light emitting element 370B, the light emitting element 370G, and the light emitting / receiving element 370SR each have a pixel electrode 371 and a common electrode 375. In this embodiment, a case will be described in which the pixel electrode 371 functions as an anode and the common electrode 375 functions as a cathode. The light emitting / receiving element 370SR is driven by applying a reverse bias between the pixel electrode 371 and the common electrode 375, so that the light emitting / receiving element 370SR can detect light incident on the light emitting / receiving element 370SR, generate electric charges, and extract the charges as a current.

[0519] The light-emitting / receiving element 370SR can be said to have a configuration in which an active layer 373 is added to a light-emitting element. In other words, the light-emitting / receiving element 370SR can be formed in parallel with the formation of the light-emitting element by simply adding a process for forming the active layer 373 to the manufacturing process of the light-emitting element. Furthermore, the light-emitting element and the light-emitting / receiving element can be formed on the same substrate. Therefore, it is possible to impart one or both of an imaging function and a sensing function to the display unit without significantly increasing the number of manufacturing processes.

[0520] There are no limitations on the stacking order of the light-emitting layer 383R and the active layer 373. Figures 33A and 33B show an example in which the active layer 373 is provided on the hole-transport layer 382, ​​and the light-emitting layer 383R is provided on the active layer 373. The stacking order of the light-emitting layer 383R and the active layer 373 may be reversed.

[0521] Furthermore, the light emitting / receiving element may not have at least one layer selected from the hole injection layer 381, the hole transport layer 382, ​​the electron transport layer 384, and the electron injection layer 385. Furthermore, the light emitting / receiving element may have other functional layers such as a hole blocking layer and an electron blocking layer.

[0522] In the light emitting / receiving element, a conductive film that transmits visible light is used for the electrode on the light extraction side, and a conductive film that reflects visible light is preferably used for the electrode on the non-light extraction side.

[0523] The functions and materials of the layers constituting the light emitting / receiving element are similar to those of the layers constituting the light emitting element and the light receiving element, and therefore detailed description thereof will be omitted.

[0524] 33C to 33G show examples of the stacked structure of the light emitting and receiving element.

[0525] The light emitting / receiving element shown in FIG. 33C has 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 .

[0526] FIG. 33C shows an example in which a light-emitting layer 383 is provided on a hole-transporting layer 382 , and an active layer 373 is stacked on the light-emitting layer 383 .

[0527] As shown in Figures 33A to 33C, the active layer 373 and the light-emitting layer 383R may be in contact with each other.

[0528] A buffer layer is preferably provided between the active layer 373 and the light-emitting layer 383R. In this case, the buffer layer preferably has hole-transporting and electron-transporting properties. For example, a bipolar substance is preferably used for the buffer layer. Alternatively, at least one layer selected from a hole-injection layer, a hole-transporting layer, an electron-transporting layer, an electron-injection layer, a hole-blocking layer, and an electron-blocking layer can be used as the buffer layer. Figure 33D shows an example in which a hole-transporting layer 382 is used as the buffer layer.

[0529] By providing a buffer layer between the active layer 373 and the light-emitting layer 383R, it is possible to suppress the transfer of excitation energy from the light-emitting layer 383R to the active layer 373. The buffer layer can also be used to adjust the optical path length (cavity length) of the microcavity structure. Therefore, a light-emitting / receiving element having a buffer layer between the active layer 373 and the light-emitting layer 383R can achieve high light-emitting efficiency.

[0530] 33E shows an example of a laminated structure in which a hole transport layer 382-1, an active layer 373, a hole transport layer 382-2, and an emitting layer 383R are laminated in this order on a hole injection layer 381. The hole transport layer 382-2 functions as a buffer layer. The hole transport layer 382-1 and the hole transport layer 382-2 may contain the same material or different materials. Alternatively, a layer that can be used as the buffer layer described above may be used instead of the hole transport layer 382-2. The positions of the active layer 373 and the emitting layer 383R may be interchanged.

[0531] 33F differs from the light emitting / receiving element shown in Fig. 33A in that it does not have the hole transport layer 382. In this way, the light emitting / receiving element may not have at least one layer among the hole injection layer 381, the hole transport layer 382, ​​the electron transport layer 384, and the electron injection layer 385. The light emitting / receiving element may also have other functional layers such as a hole blocking layer and an electron blocking layer.

[0532] The light emitting / receiving device shown in FIG. 33G differs from the light emitting / receiving device shown in FIG. 33A in that it does not have an active layer 373 and a light emitting layer 383R, but has a layer 389 that serves as both a light emitting layer and an active layer.

[0533] As a layer that serves as both a light-emitting layer and an active layer, for example, a layer containing three materials, namely, an n-type semiconductor that can be used for the active layer 373, a p-type semiconductor that can be used for the active layer 373, and a light-emitting substance that can be used for the light-emitting layer 383R, can be used.

[0534] It is preferable that the lowest energy absorption band in the absorption spectrum of the mixed material of n-type and p-type semiconductors does not overlap with the maximum peak in the emission spectrum (PL spectrum) of the luminescent substance, and it is more preferable that they are sufficiently separated from each other.

[0535] At least a part of the configuration examples exemplified in this embodiment and the corresponding drawings can be combined as appropriate with other configuration examples or drawings.

[0536] This embodiment mode can be implemented by appropriately combining at least a part thereof with other embodiment modes described in this specification.

[0537] Embodiment 6 In this embodiment, an example of a display device including a light-receiving device according to one embodiment of the present invention will be described.

[0538] In the display device of this embodiment, a pixel may be configured to have multiple types of subpixels having light-emitting devices that emit different colors. For example, a pixel may be configured to have three types of subpixels. Examples of the three subpixels include subpixels of red (R), green (G), and blue (B), or subpixels of yellow (Y), cyan (C), and magenta (M). Alternatively, a pixel may be configured to have four types of subpixels. Examples of the four subpixels include subpixels of R, G, B, and white (W), or subpixels of R, G, B, and Y.

[0539] The arrangement of the sub-pixels is not particularly limited, and various methods can be applied, such as a stripe arrangement, an S-stripe arrangement, a matrix arrangement, a delta arrangement, a Bayer arrangement, and a pentile arrangement.

[0540] Examples of the top surface shape of the sub-pixel include a triangle, a quadrangle (including a rectangle and a square), a polygon such as a pentagon, shapes of these polygons with rounded corners, an ellipse, a circle, etc. The top surface shape of the sub-pixel here corresponds to the top surface shape of the light-emitting region of the light-emitting device.

[0541] In a display device having a light-emitting device and a light-receiving device in each pixel, the pixel has a light-receiving function, so that it is possible to detect contact or proximity of an object while displaying an image. For example, in addition to displaying an image using all of the sub-pixels of the display device, some of the sub-pixels can emit light as a light source and the remaining sub-pixels can display an image.

[0542] The pixel shown in FIGS. 34A, 34B, and 34C has subpixels G, B, R, and PS.

[0543] The pixels shown in Fig. 34A are arranged in a stripe pattern, while the pixels shown in Fig. 34B are arranged in a matrix pattern.

[0544] The pixel array shown in FIG. 34C has a configuration in which three subpixels (subpixel R, subpixel G, and subpixel S) are vertically arranged next to one subpixel (subpixel B).

[0545] The pixel shown in FIGS. 34D, 34E, and 34F has subpixels G, B, R, IR, and PS.

[0546] 34D, 34E, and 34F show examples in which one pixel is provided across two rows, with the upper row (first row) having three subpixels (subpixels G, B, and R), and the lower row (second row) having two subpixels (one subpixel PS and one subpixel IR).

[0547] In Figure 34D, three vertically elongated subpixels G, B, and R are arranged horizontally, with a subpixel PS and a horizontally elongated subpixel IR arranged horizontally below them. In Figure 34E, two horizontally elongated subpixels G and R are arranged vertically, with a vertically elongated subpixel B arranged horizontally next to them, and a horizontally elongated subpixel IR and a vertically elongated subpixel PS arranged horizontally below them. In Figure 34F, three vertically elongated subpixels R, G, and B are arranged horizontally, with a horizontally elongated subpixel IR and a vertically elongated subpixel PS arranged horizontally below them. Figures 34E and 34F show a case where the area of ​​the subpixel IR is the largest and the area of ​​the subpixel PS is, for example, approximately the same as that of the subpixel B.

[0548] The layout of the sub-pixels is not limited to the configurations shown in FIGS. 34A to 34F.

[0549] Subpixel R has a light-emitting device that emits red light. Subpixel G has a light-emitting device that emits green light. Subpixel B has a light-emitting device that emits blue light. Subpixel IR has a light-emitting device that emits infrared light. Subpixel PS has a light-receiving device. There are no particular limitations on the wavelength of light detected by subpixel PS, but it is preferable that the light-receiving device of subpixel PS is sensitive to light emitted by the light-emitting device of subpixel R, subpixel G, subpixel B, or subpixel IR. For example, it is preferable to detect one or more of light in wavelength ranges such as blue, purple, blue-purple, green, yellow-green, yellow, orange, and red, as well as light in the infrared wavelength range.

[0550] The light-receiving area of ​​the subpixel PS is smaller than the light-emitting area of ​​the other subpixels. The smaller the light-receiving area, the narrower the imaging range, which makes it possible to suppress blurring in the imaging result and improve the resolution. Therefore, by using the subpixel PS, high-definition or high-resolution imaging can be performed. For example, the subpixel PS can be used to capture images for biometric authentication using fingerprints, palm prints, irises, pulse shapes (including vein shapes and arterial shapes), faces, etc.

[0551] The subpixel PS can be used as a touch sensor (also called a direct touch sensor) or a near-touch sensor (also called a hover sensor, hover touch sensor, non-contact touch sensor, or touchless sensor). For example, the subpixel PS preferably detects infrared light, which enables touch detection even in dark places.

[0552] Here, the touch sensor or near-touch sensor can detect the proximity or contact of an object (such as a finger, hand, or pen). The touch sensor can detect an object when the display device and the object are in direct contact with each other. The near-touch sensor can detect an object even if the object does not touch the display device. For example, it is preferable that the display device be configured to detect the object when the distance between the display device and the object is in the range of 0.1 mm to 300 mm, preferably 3 mm to 50 mm. This configuration makes it possible to operate the display device without the object directly touching it, in other words, to operate the display device in a non-contact (touchless) manner. This configuration reduces the risk of the display device becoming dirty or scratched, or makes it possible to operate the display device without the object directly touching dirt (e.g., dust, viruses, etc.) attached to the display device.

[0553] In order to capture high-resolution images, it is preferable that the sub-pixels PS be provided in all pixels of the display device. On the other hand, when used in a touch sensor or near-touch sensor, the sub-pixels PS do not require high accuracy compared to, for example, capturing an image of a fingerprint, so it is sufficient that the sub-pixels PS are provided in only some of the pixels of the display device. The detection speed can be increased by making the number of sub-pixels PS in the display device smaller than the number of sub-pixels R, for example.

[0554] FIG. 34G shows an example of a pixel circuit of a sub-pixel having a light-receiving device, and FIG. 34H shows an example of a pixel circuit of a sub-pixel having a light-emitting device.

[0555] 34G includes a light receiving device PD, a transistor M11, a transistor M12, a transistor M13, a transistor M14, and a capacitor C2. Here, an example is shown in which a photodiode is used as the light receiving device PD.

[0556] The light-receiving device PD has an anode electrically connected to a wiring V1 and a cathode electrically connected to one of the source and drain of a transistor M11. The transistor M11 has a gate electrically connected to a wiring TX and the other of the source and drain electrically connected to one electrode of a capacitor C2, one of the source and drain of a transistor M12, and the gate of a transistor M13. The transistor M12 has a gate electrically connected to a wiring RES and the other of the source and drain electrically connected to a wiring V2. The transistor M13 has one of the source and drain electrically connected to a wiring V3 and the other of the source and drain electrically connected to one of the source and drain of a transistor M14. The transistor M14 has a gate electrically connected to a wiring SE and the other of the source and drain electrically connected to a wiring OUT1.

[0557] A constant potential is supplied to the wiring V1, the wiring V2, and the wiring V3. When the light-receiving device PD is driven with a reverse bias, a potential higher than the potential of the wiring V1 is supplied to the wiring V2. The transistor M12 is controlled by a signal supplied to the wiring RES and has a function of resetting the potential of a node connected to the gate of the transistor M13 to the potential supplied to the wiring V2. The transistor M11 is controlled by a signal supplied to the wiring TX and has a function of controlling the timing at which the potential of the node changes depending on the current flowing through the light-receiving device PD. The transistor M13 functions as an amplifying transistor that outputs according to the potential of the node. The transistor M14 is controlled by a signal supplied to the wiring SE and functions as a selection transistor that reads out an output according to the potential of the node to an external circuit connected to the wiring OUT1.

[0558] 34H includes a light-emitting device EL, a transistor M15, a transistor M16, a transistor M17, and a capacitor C3. Here, an example is shown in which a light-emitting diode is used as the light-emitting device EL. It is particularly preferable to use an organic EL element as the light-emitting device EL.

[0559] The transistor M15 has a gate electrically connected to a wiring VG, one of its source or drain electrically connected to a wiring VS, and the other of its source or drain electrically connected to one electrode of a capacitor C3 and the gate of the transistor M16. One of the source or drain of the transistor M16 is electrically connected to a wiring V4, and the other is electrically connected to the anode of the light-emitting device EL and one of the source or drain of the transistor M17. The transistor M17 has a gate electrically connected to a wiring MS, and the other of its source or drain electrically connected to a wiring OUT2. The cathode of the light-emitting device EL is electrically connected to a wiring V5.

[0560] A constant potential is supplied to the wiring V4 and the wiring V5. The anode side of the light-emitting device EL can be set to a high potential, and the cathode side can be set to a lower potential than the anode side. The transistor M15 is controlled by a signal supplied to the wiring VG and functions as a selection transistor for controlling the selection state of the pixel circuit PIX2. The transistor M16 also functions as a drive transistor that controls the current flowing through the light-emitting device EL depending on the potential supplied to its gate. When the transistor M15 is in a conductive state, the potential supplied to the wiring VS is supplied to the gate of the transistor M16, and the light emission brightness of the light-emitting device EL can be controlled depending on the potential. The transistor M17 is controlled by a signal supplied to the wiring MS and has the function of outputting the potential between the transistor M16 and the light-emitting device EL to the outside via the wiring OUT2.

[0561] Here, it is preferable to use transistors that use a metal oxide (oxide semiconductor) in a semiconductor layer in which a channel is formed for 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.

[0562] A transistor using a metal oxide, which has a wider band gap and a lower carrier density than silicon, can achieve an extremely small off-state current. Therefore, due to the small off-state current, charge stored in a capacitor connected in series with the transistor can be held for a long period of time. Therefore, it is preferable to use a transistor including an oxide semiconductor for the transistor M11, the transistor M12, and the transistor M15, which are connected in series with the capacitor C2 or the capacitor C3. Furthermore, by using a transistor including an oxide semiconductor for the other transistors as well, manufacturing costs can be reduced.

[0563] For example, the off-state current of an OS transistor per 1 μm channel width at room temperature is 1 aA (1×10 −１８ A) Below, 1zA (1×10 −２１ A) or less, or 1yA (1 x 10−２４ Note that the off-state current of a Si transistor per 1 μm of channel width at room temperature can be 1 fA (1×10 −１５ A) More than 1pA (1×10 −１２ Therefore, it can be said that the off-state current of an OS transistor is about 10 orders of magnitude lower than that of a Si transistor.

[0564] Alternatively, the transistors M11 to M17 may be transistors in which silicon is used as a semiconductor in which a channel is formed. In particular, using silicon with high crystallinity, such as single crystal silicon or polycrystalline silicon, is preferable because high field-effect mobility can be achieved and higher-speed operation can be achieved.

[0565] Alternatively, a structure may be used in which at least one of the transistors M11 to M17 includes an oxide semiconductor and the remaining transistors include silicon.

[0566] Although the transistors are shown as n-channel transistors in FIGS. 34G and 34H, p-channel transistors can also be used.

[0567] The transistors of the pixel circuit PIX1 and the transistors of the pixel circuit PIX2 are preferably formed side by side on the same substrate. In particular, it is preferable that the transistors of the pixel circuit PIX1 and the transistors of the pixel circuit PIX2 are mixed and periodically arranged in one region.

[0568] It is also preferable to provide one or more layers having transistors and / or capacitors at positions overlapping the light receiving device PD or the light emitting device EL, thereby reducing the effective area occupied by each pixel circuit and realizing a high-definition light receiving section or display section.

[0569] Furthermore, the display device of one embodiment of the present invention can have a variable refresh rate. For example, the refresh rate can be adjusted (for example, within a range of 0.01 Hz to 240 Hz) depending on the content displayed on the display device, thereby reducing power consumption. Furthermore, driving that reduces the power consumption of the display device by driving it at a reduced refresh rate may be called idling stop (IDS) driving.

[0570] The drive frequency of the touch sensor or near-touch sensor may be changed depending on the refresh rate. For example, if the refresh rate of the display device is 120 Hz, the drive frequency of the touch sensor or near-touch sensor may be set to a frequency higher than 120 Hz (typically 240 Hz). This configuration enables low power consumption and an increased response speed of the touch sensor or near-touch sensor.

[0571] At least a part of the configuration examples exemplified in this embodiment and the corresponding drawings can be combined as appropriate with other configuration examples or drawings.

[0572] This embodiment mode can be implemented by appropriately combining at least a part thereof with other embodiment modes described in this specification.

[0573] Embodiment Mode 7 In this embodiment mode, a high-definition display device will be described.

[0574] [Example of Display Panel Configuration] Wearable electronic devices for VR, AR, etc. can provide 3D images by using parallax. In this case, it is necessary to display an image for the right eye within the field of view of the right eye and an image for the left eye within the field of view of the left eye. Here, the shape of the display unit of the display device may be a horizontally long rectangle, but pixels located outside the fields of view of the right and left eyes do not contribute to the display, so those pixels always display black.

[0575] Therefore, it is preferable to divide the display section of the display panel into two regions, one for the right eye and one for the left eye, and to configure the outer region, which does not contribute to display, without placing pixels. This reduces the power consumption required for writing pixels. Also, since the load on the source lines and gate lines is reduced, a high frame rate display becomes possible. This allows for smoother video display, enhancing the sense of realism.

[0576] Fig. 35A shows an example of the configuration of a display panel. In Fig. 35A, a display portion 702L for the left eye and a display portion 702R for the right eye are arranged inside a substrate 701. Note that in addition to the display portions 702L and 702R, a driver circuit, wiring, an IC, an FPC, or the like may also be arranged on the substrate 701.

[0577] The display units 702L and 702R shown in FIG. 35A have a square top surface shape.

[0578] The top surface shape of the display unit 702L and the display unit 702R may also be another regular polygon. FIG. 35B shows an example of a regular hexagon, FIG. 35C shows an example of a regular octagon, FIG. 35D shows an example of a regular decagon, and FIG. 35E shows an example of a regular dodecagon. In this way, by using a polygon with an even number of corners, the shape of the display unit can be made symmetrical. Note that polygons that are not regular polygons may also be used. Regular polygons or polygons with rounded corners may also be used.

[0579] Since the display unit is made up of pixels arranged in a matrix, the straight line portions of the outline of each display unit may not be straight lines in the strict sense, but may have stepped portions. In particular, straight line portions that are not parallel to the pixel arrangement direction will have a stepped top surface shape. However, since the user does not see the pixel shapes when viewing, even if the diagonal outline of the display unit is strictly stepped, it can be considered to be a straight line. Similarly, even if the curved portion of the outline of the display unit is strictly stepped, it can be considered to be a curve.

[0580] FIG. 35F shows an example in which the top surfaces of the display units 702L and 702R are circular.

[0581] The top surface shape of the display units 702L and 702R may be asymmetrical, and may not be a regular polygon.

[0582] Fig. 35G shows an example in which the top surface shapes of the display units 702L and 702R are asymmetrical octagons. Fig. 35H shows an example in which the top surface shapes of the display units 702L and 702R are asymmetrical. Even when the top surfaces of the display units 702L and 702R are asymmetrical, it is preferable to arrange the display units 702L and 702R symmetrically. This allows for the provision of natural-looking images.

[0583] Although the above description has been given of a configuration in which the display section is divided into two, it may be formed as a continuous shape.

[0584] Fig. 35I shows an example in which two circular display units 702 in Fig. 35F are connected together, and Fig. 35J shows an example in which two regular octagonal display units 702 in Fig. 35C are connected together.

[0585] The above is a description of an example of the configuration of the display panel.

[0586] At least a part of the configuration examples exemplified in this embodiment and the corresponding drawings can be combined as appropriate with other configuration examples or drawings.

[0587] This embodiment mode can be implemented by appropriately combining at least a part thereof with other embodiment modes described in this specification.

[0588] Embodiment 8 In this embodiment, a metal oxide that can be used for the OS transistor described in the above embodiment will be described.

[0589] The metal oxide used in the OS transistor preferably contains at least indium or zinc, and more preferably contains indium and zinc. For example, the metal oxide preferably contains indium, M (M is one or more selected from 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 one or more selected from gallium, aluminum, yttrium, and tin, and more preferably gallium.

[0590] The metal oxide can be formed by a sputtering method, a CVD method such as an MOCVD method, an ALD method, or the like.

[0591] Hereinafter, an oxide containing indium (In), gallium (Ga), and zinc (Zn) will be described as an example of a metal oxide. Note that an oxide containing indium (In), gallium (Ga), and zinc (Zn) may be referred to as an In—Ga—Zn oxide.

[0592] <Classification of Crystal Structure> Examples of the crystal structure of an oxide semiconductor include amorphous (including completely amorphous), c-axis-aligned crystalline line (CAAC), nanocrystalline line (nc), cloud-aligned composite (CAC), single crystal, and polycrystalline.

[0593] The crystalline structure of a film or substrate can be evaluated using an X-ray diffraction (XRD) spectrum. For example, it can be evaluated using an XRD spectrum obtained by GIXD (Grazing-Incident XRD) measurement. The GIXD method is also called the thin film method or the Seemann-Bohlin method. In the following, the XRD spectrum obtained by GIXD measurement may be simply referred to as the XRD spectrum.

[0594] For example, in the case of a quartz glass substrate, the peak shape of the XRD spectrum is almost symmetrical. On the other hand, in the case of an In-Ga-Zn oxide film having a crystalline structure, the peak shape of the XRD spectrum is asymmetrical. The asymmetrical peak shape of the XRD spectrum clearly indicates the presence of crystals in the film or substrate. In other words, if the peak shape of the XRD spectrum is not symmetrical, it cannot be said that the film or substrate is in an amorphous state.

[0595] Furthermore, the crystalline structure of a film or substrate can be evaluated by a diffraction pattern (also referred to as a nanobeam electron diffraction pattern) observed by nanobeam electron diffraction (NBED). For example, a halo is observed in the diffraction pattern of a quartz glass substrate, confirming that the quartz glass is in an amorphous state. Furthermore, a spot-like pattern is observed in the diffraction pattern of an In—Ga—Zn oxide film formed at room temperature, rather than a halo. For this reason, it is estimated that the In—Ga—Zn oxide formed at room temperature is neither single crystal nor polycrystal, nor in an amorphous state, but is in an intermediate state, and it cannot be concluded that it is in an amorphous state.

[0596] <<Structure of Oxide Semiconductor>> Note that oxide semiconductors may be classified differently from the above when focusing on their structures. For example, oxide semiconductors are classified into single-crystal oxide semiconductors and other non-single-crystal oxide semiconductors. Examples of non-single-crystal oxide semiconductors include the above-mentioned CAAC-OS and nc-OS. Non-single-crystal oxide semiconductors include polycrystalline oxide semiconductors, pseudo-amorphous-like oxide semiconductors (a-like OSs), amorphous oxide semiconductors, and the like.

[0597] Here, the above-mentioned CAAC-OS, nc-OS, and a-like OS will be described in detail.

[0598] [CAAC-OS] A CAAC-OS is an oxide semiconductor having multiple crystalline regions, each with its c-axis aligned in a specific direction. The specific direction refers to the thickness direction of the CAAC-OS film, the normal direction to the surface where the CAAC-OS film is formed, or the normal direction to the surface of the CAAC-OS film. A crystalline region is a region having periodic atomic arrangement. If the atomic arrangement is considered as a lattice arrangement, a crystalline region is also a region with a uniform lattice arrangement. Furthermore, a CAAC-OS has a region where multiple crystalline regions are connected in the a-b plane direction, and the region may have distortion. Note that distortion refers to a portion where the lattice arrangement changes between a region with a uniform lattice arrangement and a region with another uniform lattice arrangement in a region where multiple crystalline regions are connected. In other words, a CAAC-OS is an oxide semiconductor whose c-axes are aligned and whose orientation is not clearly aligned in the a-b plane direction.

[0599] Each of the multiple crystalline regions is composed of one or more minute crystals (crystals with a maximum diameter of less than 10 nm). When a crystalline region is composed of one minute crystal, the maximum diameter of the crystalline region is less than 10 nm. When a crystalline region is composed of many minute crystals, the size of the crystalline region may be several tens of nanometers.

[0600] In an In—Ga—Zn oxide, CAAC-OS tends to have a layered crystal structure (also referred to as a layered structure) in which a layer containing indium (In) and oxygen (hereinafter referred to as an In layer) and a layer containing gallium (Ga), zinc (Zn), and oxygen (hereinafter referred to as a (Ga, Zn) layer) are stacked. Note that indium and gallium are mutually substituted. Therefore, the (Ga, Zn) layer may contain indium. The In layer may contain gallium. The In layer may contain zinc. The layered structure is observed as a lattice image in a high-resolution transmission electron microscope (TEM) image, for example.

[0601] When a CAAC-OS film is subjected to structural analysis using an XRD apparatus, for example, a peak indicating c-axis orientation is detected at or near 2θ = 31° in out-of-plane XRD measurement using θ / 2θ scanning. Note that the position of the peak indicating c-axis orientation (the value of 2θ) may vary depending on the type or composition of the metal elements constituting the CAAC-OS.

[0602] For example, multiple bright spots are observed in the electron diffraction pattern of a CAAC-OS film, and the observed spots are at positions that are point-symmetric with respect to a spot of an incident electron beam that has passed through the sample (also referred to as a direct spot).

[0603] When a crystalline region is observed from the specific direction, the lattice arrangement in the crystalline region is basically a hexagonal lattice, but the unit cell is not necessarily a regular hexagon and may be a non-regular hexagon. The distortion may have a pentagonal, heptagonal, or other lattice arrangement. In the CAAC-OS, no clear grain boundary can be identified even near the distortion. This indicates that the distortion in the lattice arrangement suppresses the formation of grain boundaries. This is thought to be because the CAAC-OS can tolerate distortion due to the lack of a dense arrangement of oxygen atoms in the a-b plane and the change in interatomic bond distance caused by the substitution of metal atoms.

[0604] Note that a crystal structure in which clear grain boundaries are observed is called polycrystalline. The grain boundaries act as recombination centers, and are likely to trap carriers, resulting in a decrease in the on-state current of a transistor or a decrease in field-effect mobility. Therefore, CAAC-OS, in which clear grain boundaries are not observed, is one of the crystalline oxides having a crystal structure suitable for a semiconductor layer of a transistor. Note that a structure containing Zn is preferable for forming a CAAC-OS. For example, In—Zn oxide and In—Ga—Zn oxide are suitable because they can suppress the generation of grain boundaries more effectively than In oxide.

[0605] CAAC-OS is an oxide semiconductor with high crystallinity and no clear crystal grain boundaries. Therefore, it can be said that the CAAC-OS is less susceptible to a decrease in electron mobility due to crystal grain boundaries. Furthermore, since the crystallinity of an oxide semiconductor can be reduced by the inclusion of impurities or the generation of defects, the CAAC-OS can also be said to be an oxide semiconductor with few impurities and defects (e.g., oxygen vacancies). Therefore, an oxide semiconductor having a CAAC-OS has stable physical properties. Therefore, an oxide semiconductor having a CAAC-OS is heat-resistant and highly reliable. Furthermore, the CAAC-OS is stable even against high temperatures (so-called thermal budget) in the manufacturing process. Therefore, using a CAAC-OS for an OS transistor can increase the flexibility of the manufacturing process.

[0606] [nc-OS] The nc-OS has periodic atomic arrangement in a microscopic region (e.g., a region of 1 nm to 10 nm, particularly a region of 1 nm to 3 nm). In other words, the nc-OS has microcrystals. Note that the size of the microcrystals is, for example, 1 nm to 10 nm, particularly 1 nm to 3 nm, and therefore the microcrystals are also called nanocrystals. Furthermore, the nc-OS does not exhibit regularity in the crystal orientation between different nanocrystals. Therefore, no orientation is observed throughout the film. Therefore, depending on the analysis method, the nc-OS may be indistinguishable from an a-like OS or an amorphous oxide semiconductor. For example, when a structural analysis of an nc-OS film is performed using an XRD apparatus, no peak indicating crystallinity is detected in out-of-plane XRD measurement using θ / 2θ scanning. When an nc-OS film is subjected to electron diffraction (also referred to as selected-area electron diffraction) using an electron beam with a probe diameter larger than that of a nanocrystal (e.g., 50 nm or more), a diffraction pattern resembling a halo pattern is observed. On the other hand, when an nc-OS film is subjected to electron diffraction (also referred to as nanobeam electron diffraction) using an electron beam with a probe diameter close to or smaller than that of a nanocrystal (e.g., 1 nm to 30 nm), an electron diffraction pattern in which multiple spots are observed within a ring-shaped region centered on a direct spot may be obtained.

[0607] [a-Like OS] The a-like OS is an oxide semiconductor having a structure between the nc-OS and an amorphous oxide semiconductor. The a-like OS has pores or low-density regions. That is, the a-like OS has lower crystallinity than the nc-OS and CAAC-OS. Furthermore, the a-like OS has a higher hydrogen concentration in the film than the nc-OS and CAAC-OS.

[0608] <<Structure of Oxide Semiconductor>> Next, the above-described CAC-OS will be described in detail. Note that the CAC-OS relates to a material structure.

[0609] [CAC-OS] CAC-OS is, for example, a material in which elements constituting a metal oxide are unevenly distributed in a size of 0.5 nm to 10 nm, preferably 1 nm to 3 nm, or in the vicinity thereof. Note that hereinafter, a state in which one or more metal elements are unevenly distributed in a metal oxide and regions containing the metal elements are mixed in a size of 0.5 nm to 10 nm, preferably 1 nm to 3 nm, or in the vicinity thereof, is also referred to as a mosaic or patch state.

[0610] Furthermore, the CAC-OS has a mosaic structure in which a material is separated into a first region and a second region, and the first region is distributed throughout the film (hereinafter also referred to as a cloud structure). That is, the CAC-OS is a composite metal oxide having a structure in which the first region and the second region are mixed.

[0611] Here, the atomic ratios of In, Ga, and Zn to the metal elements constituting the CAC-OS in the In—Ga—Zn oxide are denoted as [In], [Ga], and [Zn], respectively. For example, in the CAC-OS in the In—Ga—Zn oxide, the first region is a region where [In] is larger than [In] in the composition of the CAC-OS film. The second region is a region where [Ga] is larger than [Ga] in the composition of the CAC-OS film. Alternatively, for example, the first region is a region where [In] is larger than [In] in the second region and [Ga] is smaller than [Ga] in the second region. The second region is a region where [Ga] is larger than [Ga] in the first region and [In] is smaller than [In] in the first region.

[0612] Specifically, the first region is a region whose main components are indium oxide, indium zinc oxide, etc. The second region is a region whose main components are gallium oxide, gallium zinc oxide, etc. That is, the first region can be rephrased as a region whose main component is In. The second region can be rephrased as a region whose main component is Ga.

[0613] It should be noted that there are cases where a clear boundary between the first region and the second region cannot be observed.

[0614] Furthermore, CAC-OS in In—Ga—Zn oxide refers to a structure in which a mosaic of regions containing Ga as the main component and regions containing In as the main component are randomly arranged in a material composition containing In, Ga, Zn, and O. Therefore, it is presumed that CAC-OS has a structure in which metal elements are distributed nonuniformly.

[0615] The CAC-OS can be formed by sputtering, for example, without intentionally heating the substrate. When forming the CAC-OS by sputtering, one or more of an inert gas (typically argon), oxygen gas, and nitrogen gas may be used as the deposition gas. The lower the flow rate of oxygen gas relative to the total flow rate of deposition gas during deposition, the more preferable it is. For example, the flow rate of oxygen gas relative to the total flow rate of deposition gas during deposition is set to 0% or more and less than 30%, preferably 0% or more and 10% or less.

[0616] Furthermore, for example, in the case of CAC-OS in an In—Ga—Zn oxide, EDX mapping obtained using energy dispersive X-ray spectroscopy (EDX) can confirm that the CAC-OS has a structure in which a region containing In as a main component (first region) and a region containing Ga as a main component (second region) are unevenly distributed and mixed.

[0617] Here, the first region has higher conductivity than the second region. That is, the flow of carriers through the first region causes the metal oxide to exhibit conductivity. Therefore, the first region is distributed in a cloud-like manner in the metal oxide, thereby achieving a high field-effect mobility (μ).

[0618] On the other hand, the second region has higher insulating properties than the first region. That is, the second region is distributed in the metal oxide, thereby suppressing leakage current.

[0619] Therefore, when a CAC-OS is used in a transistor, the conductivity due to the first region and the insulating property due to the second region act complementarily, thereby providing the CAC-OS with a switching function (a function of turning on / off). In other words, a CAC-OS has a conductive function in a part of the material and an insulating function in a part of the material, and the entire material functions as a semiconductor. By separating the conductive function and the insulating function, both functions can be maximized. Therefore, by using a CAC-OS in a transistor, a high on-current (I ｏｎ), high field-effect mobility (μ), and good switching behavior can be achieved.

[0620] Furthermore, a transistor using the CAC-OS has high reliability, and therefore, the CAC-OS is ideal for various semiconductor devices such as display devices.

[0621] Oxide semiconductors have a variety of structures, each of which has different characteristics. The oxide semiconductor of one embodiment of the present invention may include two or more of an amorphous oxide semiconductor, a polycrystalline oxide semiconductor, an a-like OS, a CAC-OS, an nc-OS, and a CAAC-OS.

[0622] <Transistor Having Oxide Semiconductor> Next, a case where the oxide semiconductor is used for a transistor will be described.

[0623] By using the oxide semiconductor for a transistor, a transistor with high field-effect mobility and high reliability can be realized.

[0624] For the transistor, an oxide semiconductor having a low carrier concentration is preferably used. For example, the carrier concentration of the oxide semiconductor is 1×10 １７ cm −３ Below 1 × 10, preferably １５ cm −３ More preferably, 1×10 １３ cm −３ or less, more preferably 1 × 10 １１ cm −３ More preferably, 1×10 １０ cm −３ is less than 1×10 −９ cm −３ The above is the case. Note that in order to reduce the carrier concentration of an oxide semiconductor film, the impurity concentration in the oxide semiconductor film may be reduced to reduce the density of defect states. In this specification and the like, a semiconductor having a low impurity concentration and a low density of defect states is referred to as a highly purified intrinsic or substantially highly purified intrinsic oxide semiconductor. Note that an oxide semiconductor having a low carrier concentration may also be referred to as a highly purified intrinsic or substantially highly purified intrinsic oxide semiconductor.

[0625] Furthermore, a highly purified intrinsic or substantially highly purified intrinsic oxide semiconductor film has a low density of defect states, and therefore the density of trap states may also be low.

[0626] Furthermore, charges trapped in the trap states of an oxide semiconductor take a long time to disappear and may behave like fixed charges. Therefore, a transistor in which a channel formation region is formed in an oxide semiconductor with a high density of trap states may have unstable electrical characteristics.

[0627] Therefore, reducing the impurity concentration in the oxide semiconduct...

Claims

1. A liquid crystal display device having a plurality of pixels arranged in a matrix, At least one of the pixels includes a first sub-pixel having a first light-emitting element, a second sub-pixel having a second light-emitting element, and a third sub-pixel having a light-receiving element; a first conductive layer having a region in contact with an upper surface of the first insulating layer and functioning as a pixel electrode of the first light-emitting element; a first light emitting layer having a region located above the first conductive layer; a second conductive layer having a region in contact with an upper surface of the first insulating layer and functioning as a pixel electrode of the second light-emitting element; a second light-emitting layer having a region located above the second conductive layer; a third conductive layer having a region in contact with an upper surface of the first insulating layer and functioning as a pixel electrode of the light receiving element; a layer having a photoelectric conversion material having a region located above the third conductive layer; a fourth conductive layer having a region located above the first light-emitting layer, a region located above the second light-emitting layer, and a region located above the layer having a photoelectric conversion material, and having a function as a common electrode of the first light-emitting element, a function as a common electrode of the second light-emitting element, and a function as a common electrode of the light-receiving element; a second insulating layer having a region disposed between the first light emitting element and the second light emitting element in a plan view; a third insulating layer having a region disposed between the second light emitting element and the light receiving element in a plan view; the second insulating layer comprises a first organic material; the third insulating layer comprises a second organic material; A display device, wherein the transmittance of light of a specific wavelength, which is at least a portion of the wavelengths of visible light, in the third insulating layer is lower than the transmittance of light of the specific wavelength in the second insulating layer.

2. A liquid crystal display device comprising a plurality of pixels arranged in a matrix, At least one of the pixels includes a first sub-pixel having a first light-emitting element, a second sub-pixel having a second light-emitting element, and a third sub-pixel having a light-receiving element; a first conductive layer having a region in contact with an upper surface of the first insulating layer and functioning as a pixel electrode of the first light-emitting element; a first light emitting layer having a region located above the first conductive layer; a second conductive layer having a region in contact with an upper surface of the first insulating layer and functioning as a pixel electrode of the second light-emitting element; a second light-emitting layer having a region located above the second conductive layer; a third conductive layer having a region in contact with an upper surface of the first insulating layer and functioning as a pixel electrode of the light receiving element; a layer having a photoelectric conversion material having a region located above the third conductive layer; a fourth conductive layer having a region located above the first light-emitting layer, a region located above the second light-emitting layer, and a region located above the layer having a photoelectric conversion material, and having a function as a common electrode of the first light-emitting element, a function as a common electrode of the second light-emitting element, and a function as a common electrode of the light-receiving element; a second insulating layer having a region disposed between the first light emitting element and the second light emitting element in a plan view; a third insulating layer having a region disposed between the second light emitting element and the light receiving element in a plan view; the second insulating layer comprises a first organic material; the third insulating layer comprises a second organic material; A display device, wherein the third insulating layer has a lower transmittance for light of at least one of red, green, and blue colors than the second insulating layer.

3. In claim 1 or 2, a fourth insulating layer having a region in contact with a lower surface of the second insulating layer and a region in contact with a lower surface of the third insulating layer; The display device, wherein the fourth insulating layer comprises an inorganic material.

4. In any one of claims 1 to 3, the first light emitting layer has a region in contact with a side surface of the first conductive layer, the second light-emitting layer has a region in contact with a side surface of the second conductive layer, The display device, wherein the layer having a photoelectric conversion material has a region in contact with a side surface of the third conductive layer.

5. A display device according to claim 1 ; A display module having at least one of a connector and an integrated circuit.

6. A display module according to claim 5; An electronic device having at least one of a battery, a camera, a speaker, and a microphone.