Display device

Abstract

To provide a display device having an imaging function, and a display device achieving both high viewing angle characteristics and high imaging performance.SOLUTION: The display device comprises a light-emitting / receiving element and a color filter. The light-emitting / receiving element includes a light-emitting / receiving area having a function for emitting first color light and a function for receiving second color light. The color filter is positioned on the light-emitting / receiving element, and has a function for transmitting first color light and a function for blocking second color light. The color filter has an aperture. In plane view, the light-emitting / receiving area has a portion positioned inside the aperture.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] 1. Field of the Invention One aspect of the present invention relates to a display device having an imaging function.

[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 a semiconductor device, a display device, a light-emitting device, a power storage device, a memory device, an electronic device, a lighting device, an input device, an input / output device, a driving method thereof, or a manufacturing method thereof. A semiconductor device refers to any device that can function by utilizing semiconductor characteristics. [Background technology]

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

[0004] As a display device, for example, a light-emitting device having a light-emitting element has been developed. A light-emitting element (also referred to as an EL element) utilizing the electroluminescence (hereinafter referred to as EL) phenomenon has features such as being easily thin and lightweight, being capable of responding quickly to an input signal, and being capable of being driven by a DC constant voltage power supply, and is applied to a display device. For example, Patent Document 1 discloses a flexible light-emitting device to which an organic EL element is applied. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2014-197522 A Summary of the Invention [Problem to be solved by the invention]

[0006] An object of one embodiment of the present invention is to provide a display device having an imaging function.An object of one embodiment of the present invention is to provide an imaging device or a display device that can clearly capture an image of a fingerprint or the like.An object of one embodiment of the present invention is to provide a display device with improved viewing angle characteristics.An object of one embodiment of the present invention is to provide a display device that has both high viewing angle characteristics and high imaging performance.An object of one embodiment of the present invention is to provide an imaging device or a display device that can capture images with high sensitivity.An object of one embodiment of the present invention is to provide a display device that functions as a touch panel.

[0007] An object of one embodiment of the present invention is to reduce the number of components of an electronic device.An object of one embodiment of the present invention is to provide a multifunctional display device.An object of one embodiment of the present invention is to provide a display device, an imaging device, an electronic device, or the like having a novel structure.An object of one embodiment of the present invention is to reduce at least one of the problems of the prior art.

[0008] 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 of the specification, drawings, claims, etc. [Means for solving the problem]

[0009] One embodiment of the present invention is a display device having a light-emitting / receiving element and a color filter. The light-emitting / receiving element has a light-emitting / receiving region that has a function of emitting light of a first color and a function of receiving light of a second color. The color filter is located on the light-emitting / receiving element and has a function of transmitting light of the first color and a function of blocking light of the second color. The color filter has an opening. In addition, in a plan view, the light-emitting / receiving region has a portion located inside the opening.

[0010] The display device preferably has a portion where the color filter and an outer edge of the light receiving and emitting region overlap in a plan view.

[0011] In the display device, it is preferable that an end of the light emitting and receiving region is located inside the opening in a plan view, and that there is a gap between the light emitting and receiving region and the color filter.

[0012] In the above, it is preferable to further have a light-shielding layer. In this case, the light-shielding layer is located on the light-receiving and light-emitting elements and has a function of blocking the first color light and the second color light. In addition, it is preferable that the light-shielding layer is located outside the opening of the color filter in a plan view. Furthermore, it is preferable that the color filter has a first portion and a second portion. The first portion is a portion that overlaps with the light-shielding layer in a plan view, and the second portion is a portion that is located between the first portion and the opening in a plan view and does not overlap with either the light-shielding layer or the light-receiving and light-emitting elements.

[0013] In the above, it is preferable that the light emitting device further comprises a light emitting element. In this case, it is preferable that the light emitting element has a light emitting region having a function of emitting light of the second color. Furthermore, it is preferable that the light emitting element is provided on the same surface as the light emitting / receiving element.

[0014] In the above, the light emitting / receiving element preferably has an electron injection layer, an electron transport layer, a light emitting layer, an active layer, a hole injection layer, and a hole transport layer between the pixel electrode and the first electrode. In this case, the light emitting element preferably has one or more of the first electrode, the electron injection layer, the electron transport layer, the hole injection layer, and the hole transport layer.

[0015] In addition, in the display device, it is preferable that the light-shielding layer is located between the light-receiving and light-emitting elements and the light-emitting element in a plan view. Furthermore, it is preferable that the light-shielding layer does not overlap with the light-emitting region of the light-emitting element in a plan view, and that there is a gap between an end of the light-shielding layer and an end of the light-emitting region.

[0016] In the above, it is preferable to further include a first substrate and a second substrate. In this case, the first substrate and the second substrate are provided facing each other. Also, the light emitting / receiving elements and the color filter are provided between the first substrate and the second substrate. Furthermore, it is preferable that the light emitting / receiving elements are provided on the first substrate, and the color filter is provided on the second substrate.

[0017] In the above, it is preferable that the liquid crystal display further includes a functional layer. In this case, the functional layer is preferably provided on and in contact with the surface of the second substrate opposite to the surface on which the color filter is provided. In addition, it is preferable that the functional layer has a lower refractive index than the second substrate.

[0018] In the above, when the distance between the light emitting / receiving element and the second substrate is T1 and the minimum width of the light emitting / receiving area of ​​the light emitting / receiving element is W1, it is preferable that T1 is 0.1 to 10 times W1.

[0019] In the above, when the thickness of the second substrate is T2, it is preferable that T2 is 5 times or more and 100 times or less than T1.

[0020] Another embodiment of the present invention is a display module including any one of the display devices described above and a connector or an integrated circuit.

[0021] Another embodiment of the present invention is an electronic device including the above-described display module and at least one of an antenna, a battery, a housing, a camera, a speaker, a microphone, a touch sensor, and an operation button. Effect of the Invention

[0022] According to one embodiment of the present invention, a display device having an imaging function can be provided. Alternatively, an imaging device or display device capable of clearly capturing an image of a fingerprint or the like can be provided. Alternatively, a display device with improved viewing angle characteristics can be provided. Alternatively, a display device having both high viewing angle characteristics and high imaging performance can be provided. Alternatively, an imaging device or display device capable of capturing images with high sensitivity can be provided. Alternatively, a display device functioning as a touch panel can be provided.

[0023] According to one aspect of the present invention, it is possible to reduce the number of components in an electronic device, to provide a multifunctional display device, to provide a display device, an imaging device, or an electronic device having a novel configuration, or to alleviate at least one of the problems of the prior art.

[0024] 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. [Brief description of the drawings]

[0025] [Figure 1] 1A to 1C are cross-sectional views showing an example of a display device. [Diagram 2] 2A to 2C are cross-sectional views showing an example of a display device. [Diagram 3] 3A and 3B are cross-sectional views showing an example of a display device. [Figure 4] FIG. 4 is a cross-sectional view showing an example of a display device. [Diagram 5] 5A and 5B are cross-sectional views showing an example of a display device. [Figure 6] 6A and 6B are top views showing an example of a display device. [Figure 7] 7A to 7C are cross-sectional views showing an example of a display device. [Figure 8] 8A to 8C are cross-sectional views showing an example of a display device. [Figure 9] 9A and 9B are cross-sectional views showing an example of a display device. [Figure 10] 10A to 10D are cross-sectional views showing an example of a display device, and FIGs. 10E to 10G are top views showing an example of a pixel. [Figure 11] 11A to 11D are top views showing an example of a pixel. [Figure 12] 12A to 12E are cross-sectional views showing an example of a light emitting / receiving element. [Figure 13] 13A and 13B are cross-sectional views showing an example of a display device. [Figure 14] 14A and 14B are cross-sectional views showing an example of a display device. [Figure 15] 15A and 15B are cross-sectional views showing an example of a display device. [Figure 16] 16A and 16B are cross-sectional views showing an example of a display device. [Figure 17] 17A and 17B are cross-sectional views showing an example of a display device. [Figure 18] FIG. 18 is a perspective view showing an example of a display device. [Figure 19] FIG. 19 is a cross-sectional view showing an example of a display device. [Figure 20] FIG. 20 is a cross-sectional view showing an example of a display device. [Figure 21] Fig. 21A is a cross-sectional view showing an example of a display device, and Fig. 21B is a cross-sectional view showing an example of a transistor. [Figure 22] 22A and 22B are diagrams showing an example of an electronic device. [Diagram 23] 23A to 23D are diagrams showing an example of an electronic device. [Figure 24] 24A to 24F are diagrams showing an example of an electronic device. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0026] Hereinafter, the embodiments will be described with reference to the drawings. However, it will be easily understood by those skilled in the art that the embodiments can be implemented in many different ways, and that the modes and details can be changed in various ways without departing from the spirit and scope of the present invention. Therefore, the present invention should not be interpreted as being limited to the description of the following embodiments.

[0027] 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 the repeated explanations are omitted. In addition, when referring to similar functions, the same hatch pattern may be used and no particular reference numeral may be used.

[0028] In addition, in each figure 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.

[0029] In addition, ordinal numbers such as "first" and "second" in this specification are used to avoid confusion of components and do not limit the numbers.

[0030] In this specification, the EL layer refers to a layer that is provided between a pair of electrodes of a light-emitting element and contains at least a light-emitting substance (also referred to as a light-emitting layer), or a stack that contains a light-emitting layer.

[0031] In this specification, the photoelectric conversion layer is provided between a pair of electrodes of a light receiving element and refers to at least an active layer or a laminate including an active layer. The active layer refers to a layer having a function of generating electron-hole pairs by absorbing light. The active layer includes a single layer and a laminate.

[0032] (Embodiment 1) In this embodiment, a structure example of a display device according to one embodiment of the present invention will be described.

[0033] One embodiment of the present invention is a display device having a plurality of pixels arranged in a matrix. Each pixel has one or more light emitting and receiving elements.

[0034] The light emitting / receiving element (also called a light emitting / receiving device) is an element that has both a function as a light emitting element (also called a light emitting device) that emits light of a first color and a function as a photoelectric conversion element (also called a photoelectric conversion device) that receives light of a second color. The light emitting / receiving element can also be called a multifunctional element, a multifunctional diode, a light emitting photodiode, a bidirectional photodiode, or the like.

[0035] A display device having a plurality of pixels each having a light emitting element and a light receiving element arranged in a matrix can have both a function of displaying an image and a function of capturing an image. Therefore, the display device according to one embodiment of the present invention can be called a composite device or a multifunction device.

[0036] When displaying an image using multiple light-receiving and light-emitting elements, it is preferable that the angle dependency of the luminance and chromaticity of light emitted from one light-receiving and light-emitting element is smaller, since this improves the viewing angle characteristics of the display device. On the other hand, when capturing an image using multiple light-receiving and light-emitting elements, if light is incident on one light-receiving and light-emitting element from a wide range, the image becomes blurred, making it difficult to obtain a clear image. In other words, it is preferable that the light-receiving and light-emitting element is configured so that only light is incident on the light-receiving and light-emitting element from a direction perpendicular to its surface as much as possible.

[0037] However, narrowing the angle range of light that can be incident on the light receiving / emitting element makes it impossible to extract light emitted from the light receiving / emitting element in an oblique direction, resulting in a deterioration in viewing angle characteristics. On the other hand, widening the angle range of light emitted from the light receiving / emitting element causes light from a wide angle range to be incident on the light receiving / emitting element, making it difficult to obtain a clear image. Therefore, in a configuration in which the light receiving / emitting element is used to both capture and display images, it is difficult to achieve both good viewing angle characteristics and the capture of a clear image.

[0038] Therefore, in one aspect of the present invention, a color filter that transmits the first color light emitted by the light receiving / emitting element and blocks the second color light received by the light receiving / emitting element is provided above the light receiving / emitting element (i.e., on the display surface side and the light receiving surface side of the display device). Furthermore, an opening is provided in the color filter that overlaps with the light receiving / emitting area of ​​the light receiving / emitting element. As a result, of the first color light emitted by the light receiving / emitting element, light in a direction approximately perpendicular to the surface of the light receiving / emitting element passes through the opening of the color filter, and light in an oblique direction passes through the color filter and is emitted to the outside. This allows the display device to display an image with excellent viewing angle characteristics. Furthermore, when the light receiving / emitting element receives light, the light that is obliquely incident on the surface of the light receiving / emitting element is blocked by the color filter, so that only light from a direction approximately perpendicular to the surface of the light receiving / emitting element is incident on the light receiving / emitting element. This allows a clear image to be captured.

[0039] A more specific configuration example will be described below with reference to the drawings.

[0040] [Configuration example 1] 1A shows a schematic cross-sectional view of a display device 10 according to one embodiment of the present invention. The display device 10 has a light emitting / receiving element 20 and a color filter 31 between a substrate 11 and a substrate 12 disposed opposite each other.

[0041] An element layer 15 is provided over the substrate 11. The element layer 15 is a layer including circuits, wiring, and the like for driving the light emitting and receiving elements 20. For example, the element layer 15 includes transistors, capacitors, resistors, wiring, electrodes, and the like.

[0042] The light emitting / receiving element 20 has a structure in which a conductive layer 21, an organic layer 22, and a conductive layer 23 are laminated. The conductive layer 21 functions as a pixel electrode, and is electrically connected to a circuit in the element layer 15. The conductive layer 21 is preferably reflective to the light emitted by the light emitting / receiving element 20 and the light received by the light emitting / receiving element 20. The organic layer 22 has at least an EL layer and a photoelectric conversion layer. The conductive layer 23 functions as a common electrode. The conductive layer 23 is preferably translucent to the light emitted by the light emitting / receiving element 20 and the light received by the light emitting / receiving element 20.

[0043] The light receiving / emitting element 20 has a function of emitting light 30R of a first color and a function of receiving light 30G of a second color. Here, it is preferable that the light 30R is light having a longer wavelength than the light 30G. This can prevent the light 30R emitted by the light receiving / emitting element 20 from being absorbed by the photoelectric conversion layer of the light receiving / emitting element 20, thereby suppressing a decrease in the light emitting efficiency of the light receiving / emitting element 20. For example, the light receiving / emitting element 20 can be applied with a function of emitting red light and an element that receives light of a shorter wavelength than the red light (for example, green light, blue light, or both of these lights). Note that one or both of the light emitted by the light receiving / emitting element 20 and the light received by the light receiving / emitting element 20 are not limited to visible light, and may be infrared light or ultraviolet light.

[0044] Furthermore, an insulating layer 41 is provided to cover the end portion of the conductive layer 21 and the element layer 15. The organic layer 22 is provided to cover the upper surface of the insulating layer 41 and the upper surface of the conductive layer 21. Furthermore, the conductive layer 23 is provided to cover the organic layer 22. The conductive layer 21 and the organic layer 22 are provided in contact with each other in a region surrounded by the insulating layer 41 on the conductive layer 21. This region contributes to the light emission and reception of the light receiving and emitting element 20, and will hereinafter be referred to as a light receiving and receiving region R.

[0045] In addition, an adhesive layer 42 is provided on the conductive layer 23. The adhesive layer 42 has a function of bonding the substrate 11 and the substrate 12 together. The adhesive layer 42 may also function as a sealing layer that seals the light emitting / receiving element 20.

[0046] A color filter 31 is provided on the surface of the substrate 12 facing the light receiving / emitting element 20. The color filter 31 has a function of transmitting light (first color light 30R) emitted by the light receiving / emitting element 20 and blocking light (second color light 30G) received by the light receiving / emitting element 20. The color filter 31 may have a function of reflecting the second color light 30G, but more preferably has a function of absorbing the second color light 30G.

[0047] Moreover, the color filter 31 has an opening 20h overlapping with the light emitting / receiving element 20. The opening 20h of the color filter 31 is provided so as to overlap with the light emitting / receiving region R of the light emitting / receiving element 20 in a plan view. Moreover, the color filter 31 has a portion that does not overlap with the light emitting / receiving element 20 in a plan view.

[0048] In this specification and the like, the plan view refers to a view from the display surface side and the light receiving surface side (for example, the outer surface of the substrate 12) of the display device 10. Specifically, the plan view refers to a view from the normal direction of the surface of the substrate 12 opposite to the surface on which the color filter 31 is provided.

[0049] 1B is a schematic diagram showing how the light receiving / emitting element 20 emits light. As shown in FIG. 1B, light 30R1 emitted from the light receiving / emitting element 20 in a generally upward direction is emitted to the outside through the opening 20h of the color filter 31. On the other hand, light 30R2 emitted in an oblique direction from the light receiving / emitting element 20 passes through the color filter 31 and is emitted to the outside. Therefore, light is emitted from the light receiving / emitting element 20 over a wide angle range.

[0050] Here, there may be a difference in wavelength between the light emitted from the light receiving / emitting element 20 in a direction perpendicular to the light emitting surface and the light emitted in an oblique direction. In that case, a difference in chromaticity is observed when viewed from an oblique direction. However, in the display device 10, even if the light receiving / emitting element 20 having such characteristics is used, the light emitted in an oblique direction passes through the color filter 31, thereby enhancing the color purity, and a secondary effect is achieved in that the difference in chromaticity due to differences in viewing angles is less noticeable.

[0051] FIG. 1C shows a schematic diagram of light incident on the light receiving / emitting element 20 from the outside. As shown in FIG. 1C, light 30G1 incident on the light receiving / emitting element 20 from a substantially perpendicular direction reaches the light receiving / emitting element 20 through the opening 20h of the color filter 31. On the other hand, light 30G2 incident from an oblique direction is blocked (absorbed or reflected) by the color filter 31 and does not reach the light receiving / emitting element 20. In addition, even if light passes through the opening 20h of the color filter 31, light with a large angle of incidence like light 30G3 (i.e., light incident from an oblique direction on the surface of the substrate 12) does not reach the light receiving / emitting element 20, and therefore does not contribute to light reception by the light receiving / emitting element 20. Therefore, only light incident from a substantially perpendicular direction is received by the light receiving / emitting element 20. This makes it possible to capture a clear image with little blur.

[0052] The greater the distance between the color filter 31 and the light emitting / receiving element 20, the more the range in which light can enter the light emitting / receiving element 20 can be narrowed, and the clearer the image can be captured.

[0053] [Configuration example 2] 2A shows a schematic cross-sectional view of a display device 10a that is partially different in configuration from the display device 10. The display device 10a differs from the display device 10 mainly in that it has a light-shielding layer 32.

[0054] The light-shielding layer 32 is provided on the surface of the substrate 12 facing the substrate 11. Fig. 2A shows an example in which the light-shielding layer 32 is provided between the substrate 12 and the color filter 31. Note that the color filter 31 may be configured to be located between the light-shielding layer 32 and the substrate 12.

[0055] The light-shielding layer 32 can block (absorb or reflect) both the first color light emitted by the light-receiving / light-emitting element 20 and the second color light received by the light-receiving / light-emitting element 20. In particular, it is preferable to use a material that absorbs visible light as the light-shielding layer 32. For example, the light-shielding layer 32 can be a black matrix formed using a metal material, or a resin material containing a pigment (carbon black, etc.) or a dye. Alternatively, the light-shielding layer 32 can be a laminate in which two or more of a red color filter, a green color filter, and a blue color filter are laminated.

[0056] In a plan view, the light-shielding layer 32 is located outside the opening 20h of the color filter 31. In other words, in a plan view, the opening 20h of the color filter 31 is located inside a pair of ends of the light-shielding layer 32 that sandwich the light-receiving and light-emitting element 20. In this case, the color filter 31 has a portion that overlaps with the light-shielding layer 32 in a plan view, and a portion that is located between the opening 20h and the light-shielding layer 32 and does not overlap with either the light-shielding layer 32 or the light-receiving and light-emitting element 20.

[0057] 2B is a schematic diagram showing the light emitted by the light receiving / emitting element 20. Light 30R2 emitted in an oblique direction from the light receiving / emitting element 20 passes through the color filter 31 inside the light blocking layer 32 and is emitted to the outside. The wider the distance between the pair of ends of the light blocking layer 32, that is, the wider the area of ​​the color filter 31 that does not overlap with the light blocking layer 32, the wider the angle range over which light can be emitted from the light receiving / emitting element 20.

[0058] 2C shows a state in which light from the outside is incident on the light receiving / emitting element 20. Of the light that is incident on the light receiving / emitting element 20 from an oblique direction, light 30G2 that reaches the color filter 31 is blocked by the color filter 31 and does not reach the light receiving / emitting element 20. In addition, light 30G4 that reaches the light blocking layer 32 is blocked (absorbed or reflected) by the light blocking layer 32 and does not reach the light receiving / emitting element 20.

[0059] By providing the light-shielding layer 32, it is possible to reduce the amount of light that can be transmitted through the color filter 31 and enter the light-receiving / light-emitting element 20. In addition to the light that enters from the outside of the display device 10a, the light-shielding layer 32 can absorb a part of the light (also called stray light) that diffuses (guides) inside the display device 10a (for example, the adhesive layer 42). This makes it possible to reduce unnecessary light that can enter the light-receiving / light-emitting element 20, thereby reducing noise and enabling a clear image to be captured.

[0060] [Variations] 1A and 2A show an example in which the width of the opening 20h of the color filter 31 is formed to be approximately the same as the width of the light emitting / receiving region R of the light emitting / receiving element 20, but this is not limiting.

[0061] In the display device 10b shown in FIG. 3A, the opening 20h of the color filter 31 is located inside the light receiving and emitting region R of the light receiving and emitting element 20.

[0062] Here, the light emitting and receiving region R of the light emitting and receiving element 20 is a region surrounded by the edge of the insulating layer 41 located on the conductive layer 21. In other words, the region where the conductive layer 21 and the organic layer 22 are in contact with each other can also be called the light emitting and receiving region R.

[0063] The color filter 31 of the display device 10b has a portion that overlaps with the outer edge of the light receiving / emitting region R of the light receiving / emitting element 20 in a plan view. This makes the opening 20h of the color filter 31 smaller, and the light irradiated from the outside to the light receiving / emitting element 20 can be further narrowed. Therefore, light that is obliquely incident on the light receiving / emitting element 20 can be blocked more effectively, and a clearer image can be captured. Note that the outer edge of a certain area refers to an area that includes the edge (also called the outline or outer periphery) of the area and a part of the area along the edge.

[0064] FIG. 3B is a schematic cross-sectional view of a display device 10c in which the light receiving and emitting region R is formed so as to be located inside the opening 20h of the color filter 31 in a plan view.

[0065] In the display device 10c, an end of the light receiving and emitting region R is located inside the opening 20h in a plan view. Furthermore, a region (gap) in which neither the light receiving and emitting region R nor the color filter 31 is provided is provided between the light receiving and emitting region R and the color filter 31 in a plan view.

[0066] With this configuration, it is possible to increase the amount of light emitted from the light receiving / emitting element 20 and emitted to the outside through the opening 20h of the color filter 31. This improves visibility when viewed from the front. In addition, by making the width of the opening 20h of the color filter 31 larger than the width of the light receiving / emitting region R, it is possible to increase the amount of light incident on the light receiving / emitting element 20, thereby improving the sensitivity of the light receiving / emitting element 20 during imaging.

[0067] Although the display device 10b and the display device 10c each have the light-shielding layer 32, the display device 10 may have a configuration not including the light-shielding layer 32, as in the display device 10.

[0068] [Configuration example 3] Next, a more specific example of the structure of the display device of one embodiment of the present invention will be described with reference to FIG.

[0069] As shown in FIG. 4, the thickness of the substrate 12 is T CS The distance from the upper surface of the conductive layer 21 of the light emitting / receiving element 20 to the surface of the substrate 12 on the substrate 11 side is T gap Here, it is assumed that the light-shielding layer 32 is provided in contact with the surface of the substrate 12 on the substrate 11 side.

[0070] The width of the opening 20h of the color filter 31 in cross section is W CF Let us assume that CF is the distance between a pair of opposing ends of the color filter 31. Also, the width of the light emitting / receiving region of the light emitting / receiving element 20 is W R Here, W R W CF Further, the distance between the pair of opposing ends of the light-shielding layer 32 (also called the opening width of the light-shielding layer 32) is set to W BM Let us assume that BM is W CF and W R It is preferable that the value is larger than either of the above.

[0071] Here, the opening width W of the light-shielding layer 32 BM is particularly important because it affects the viewing angle characteristics of the displayed image. BM If the opening width W of the light-shielding layer 32 is too small, the light emitted in an oblique direction from the light-receiving / light-emitting element 20 is blocked, resulting in a display device with a narrow viewing angle. BM If is too large, the area occupied by one pixel becomes large, making it difficult to increase the resolution.

[0072] 4, the optical path of light 30R emitted in an oblique direction from an end of the light receiving / emitting element 20's light receiving / emitting region is shown by a dashed arrow. For convenience, the diagram is shown without taking into consideration the refraction of light between the light receiving / emitting element 20 and the adhesive layer 42, and between the adhesive layer 42 and the color filter 31.

[0073] Here, of the light 30R emitted from the light receiving / emitting element 20 and incident on the substrate 12, the light 30R near the end of the light shielding layer 32 is the light that has the largest angle of incidence on the substrate 12. The maximum value of this angle of incidence is set to θ0, and the refraction angle at this time is set to θ1. At this time, the angle of incidence of the light emitted from the substrate 12 to the outside (air) is also set to θ1. In addition, the refraction angle of the light emitted from the substrate 12 to the outside is set to θ2.

[0074] The refractive index of the substrate 12 is n CS If the refractive index of the outside is 1, the critical angle of the angle θ1 at the interface between the substrate 12 and the outside is sinθ1=1 / n CS For example, the angle is n CS When is 1.5, the critical angle is about 41.81 degrees, and when n CS When is 1.45, the critical angle is about 43.60 degrees, and when n CS When is 1.40, the critical angle is approximately 45.58 degrees.

[0075] Here, the closer the refraction angle θ2 of the light emitted from the substrate 12 to the outside is to 90 degrees, the closer the viewing angle of the display device is to 180 degrees, and therefore the display device can have excellent viewing angle characteristics. CS and the largest incident angle θ1 of the light incident on the substrate 12 is n CS The opening width W of the light-shielding layer 32 is set so that ×sinθ1 satisfies 0.8 to 1.2, preferably 0.9 to 1.1, and more preferably 0.95 to 1.0. BM , the width of the light-emitting / receiving area W R , and distance T gap For example, it is preferable to design θ1 to be equal to or greater than 41 degrees and equal to or less than 48 degrees, preferably equal to or greater than 42 degrees and equal to or less than 46 degrees, and typically close to 45 degrees.

[0076] Also, the distance T gap The larger the distance T is, the more effectively the light incident from an oblique direction from among the light incident on the light receiving / emitting element 20 from the outside can be blocked, and the clearer the image can be captured. gap is the width W of the light emitting / receiving region of the light emitting / receiving element 20 RIt is preferable to set the width W of the light receiving and emitting region to 0.1 times or more and 10 times or less, preferably 0.5 times or more and 5 times or less, more preferably 0.6 times or more and 4 times or less, and further preferably 0.7 times or more and 3 times or less. R can take different values ​​depending on the top surface shape of the light emitting / receiving element 20 and the cutting direction, and the smallest width among them is the width W R It can be said that:

[0077] In addition, the thickness T of the substrate 12 CS The thicker the substrate 12, the higher the mechanical strength of the display surface side of the display device. On the other hand, if the substrate 12 is too thick, even if the object to be imaged is provided in contact with the display surface, the distance between the object to be imaged and the light-receiving / light-emitting elements 20 becomes large, so that the imaging range of one light-receiving / light-emitting element 20 becomes wide, and there is a risk that a clear image cannot be obtained. Therefore, the thickness T of the substrate 12 is set to be 100 mm. CS Even if the thickness is large, the distance T gap By increasing the thickness, it becomes easier to obtain a clear image. CS is the distance T gap The concentration is preferably 1 to 200 times, more preferably 5 to 100 times, even more preferably 10 to 80 times, and even more preferably 10 to 50 times.

[0078] [Configuration example 4] The display device of one embodiment of the present invention can clearly capture an image of an object in contact with the display surface. For example, a fingerprint, a palm print, or the like can be suitably captured. In addition, the display device can be used as an image scanner by capturing an image of an object placed on the display surface. In addition, the display device can function as a touch panel by acquiring positional information or shape information of an object in contact with the display surface.

[0079] FIG. 5A shows a state where a scatterer 19 is in contact with the upper surface of the substrate 12. Examples of the scatterer 19 include various objects that are the subject of imaging, such as a finger, a palm, a stylus pen, and a printed matter. The scatterer 19 is preferably an object that scatters light on its surface. When light hits the surface or the vicinity of the surface of the scatterer 19, scattering occurs. For example, the scattered light from a printed matter or the tip of a stylus pen has small angle dependency and shows an isotropic intensity distribution. Similarly, the scattered light scattered on the surface of the skin of a finger or palm shows an isotropic intensity distribution. In FIG. 5A, scattered light 30 from multiple points of the scatterer 19 is shown. Ref is indicated by an arrow.

[0080] FIG. 5A shows scattered light 30 in various directions. Ref Among these, the optical path of a portion of the light passing through the opening of the color filter 31 is indicated by a dashed arrow.

[0081] 5A, light traveling in a direction approximately perpendicular to the contact surface between the scatterer 19 and the substrate 12 is not easily affected by refraction and reaches the light receiving / emitting element 20. On the other hand, light traveling in a direction oblique to the contact surface may not reach the light receiving / emitting element 20 due to refraction at the interface between the substrate 12 and the adhesive layer 42. In other words, even if the scatterer 19 is located directly above the light receiving / emitting element 20, the scattered light 30 of the scatterer 19 may not reach the light receiving / emitting element 20. Ref However, the light receiving / emitting element 20 cannot receive all of the light, and only a part of the light is received by the light receiving / emitting element 20. CS or the distance T between the substrate 12 and the light emitting / receiving element 20 gap When the amount of scattered light 30 that can be received by the light receiving / emitting element 20 is large, Ref The decrease in strength becomes more pronounced.

[0082] Therefore, as shown in Fig. 5B, it is preferable to provide a functional layer 16 on the surface of the substrate 12. The functional layer 16 is a layer that is translucent and has a lower refractive index than the substrate 12. For example, a resin, an inorganic film (including an oxide film and a nitride film), a metal film, or a glass with a low refractive index can be used as the functional layer 16. The functional layer 16 may be a thin film or a coating agent formed on the surface of the substrate 12, or may be a film-like, sheet-like, or plate-like member that is bonded to the surface of the substrate 12.

[0083] When a resin is used for the functional layer 16, it is preferable to use a material containing a fluororesin such as polytetrafluoroethylene, chlorotrifluoroethylene, polyvinylidene fluoride, or polyvinyl fluoride, or a fluororesin copolymer such as perfluoroalkoxy fluororesin, since this can improve the scratch resistance, antifouling property, or slipperiness of the surface of the substrate 12. A siloxane-based resin such as an organic polysiloxane having a low refractive index may also be used. Here, the siloxane-based resin corresponds to a resin containing a Si-O-Si bond formed using a siloxane-based material as a starting material. The siloxane-based resin may use an organic group (e.g., an alkyl group or an aryl group) or a fluoro group as a substituent. The organic group may have a fluoro group.

[0084] The effect of providing the functional layer 16 between the substrate 12 and the scatterer 19 will be described. As shown in FIG. 5B, the light scattered on the surface of the scatterer 19 is refracted at the interface between the functional layer 16 and the substrate 12. At this time, since the refractive index of the substrate 12 is higher than that of the functional layer 16, the light is refracted so as to approach a direction perpendicular to the surface of the substrate 12. Then, the light is refracted again at the interface between the substrate 12 and the adhesive layer 42, and reaches the substrate 11 side. In this way, the light can be condensed by refracting the light at the interface between the functional layer 16 and the substrate 12. As a result, the amount of light reaching the light receiving / emitting element 20 can be increased as shown in FIG. 5B.

[0085] Here, the thickness T of the functional layer 16 f The thinner the better. fThe thinner the thickness, the closer the interface between the functional layer 16 for refracting light and the substrate 12 can be to the surface of the scatterer 19 (i.e., the scattering surface). Ref Since the optical path of the light traveling in an oblique direction can be shortened, the amount of light that reaches the light receiving / emitting element 20 can be increased.

[0086] Thickness T of functional layer 16 f The thickness T of the functional layer 16 can be, for example, 1 mm or less, preferably 0.5 mm or less, more preferably 0.3 mm or less, even more preferably 0.1 mm or less, and even more preferably 0.05 mm or less. f The lower limit of the thickness is preferably as thin as possible, and may be, for example, 10 nm or more, 50 nm or more, 100 nm or more, 500 nm or more, 1 μm or more, 5 μm or more, or 10 μm or more. The above upper and lower limits may be combined in any combination.

[0087] [Configuration example 5] An example of a display device having a light receiving / emitting element and a light emitting element will be described below. By providing a light receiving / emitting element that emits light of a first color and receives light of a second color, and a light emitting element that emits light of the second color in a display device, the light emitting element can be used as a light source for imaging. Furthermore, by providing a light emitting element that emits light of a third color in addition to the above in the display device, a display device that can display a full-color image can be realized.

[0088] 6A shows a schematic top view of one pixel 60a arranged in the display region of the display device. The pixel 60a has a light receiving / emitting element 20, a light emitting element 50G, and a light emitting element 50B. For example, the light receiving / emitting element 20 can be an element that emits red light and receives either or both of green light and blue light. The light emitting element 50G can be an element that emits green light, and the light emitting element 50B can be an element that emits blue light.

[0089] The pixel 60a shown in Fig. 6A is a pixel in a so-called stripe arrangement in which the light-receiving / emitting element 20, the light-emitting element 50G, and the light-emitting element 50B are arranged in this order in the horizontal direction. The light-receiving / emitting element 20, the light-emitting element 50G, and the light-emitting element 50B each have a roughly rectangular shape and are arranged so that their longitudinal direction is parallel to the vertical direction. Within the display area of ​​the display device, a plurality of pixels 60a are arranged in a matrix in the vertical and horizontal directions.

[0090] In FIG. 6A, a light-shielding layer 32 is provided. Here, the light-shielding layer 32 is provided so as to surround the light-receiving / emitting element 20, the light-emitting element 50G, and the light-emitting element 50B. In other words, the light-shielding layer 32 has openings that overlap with the light-receiving / emitting element 20, the light-emitting element 50G, and the light-emitting element 50B, respectively. The light-receiving / emitting element 20, the light-emitting element 50G, and the light-emitting element 50B are each located inside the opening of the light-shielding layer 32 and arranged so as not to overlap with the light-shielding layer 32. In addition, gaps 61 are provided between the light-emitting element 50G and the light-shielding layer 32 and between the light-emitting element 50B and the light-shielding layer 32 in a plan view.

[0091] A color filter 31 is provided so as to overlap a part of the light receiving / emitting element 20. The color filter 31 is provided so as to overlap an outer edge of the light receiving / emitting area of ​​the light receiving / emitting element 20. Another part of the color filter 31 is provided so as to overlap the light blocking layer 32. As described above, the color filter 31 and the light receiving / emitting area of ​​the light receiving / emitting element 20 may be disposed so as not to overlap each other. In this case, a gap is provided between the end of the color filter and the light receiving / emitting area of ​​the light receiving / emitting element 20.

[0092] Fig. 6B shows a pixel configuration different from the above. In the example shown in Fig. 6B, a pixel 60b having a light emitting / receiving element 20 and a light emitting element 50G and a pixel 60c having a light emitting / receiving element 20 and a light emitting element 50B are arranged alternately in the vertical and horizontal directions.

[0093] In Fig. 6B, the upper surface of the light-receiving / emitting element 20, the light-emitting element 50G, and the light-emitting element 50B is roughly square and inclined at 45 degrees with respect to the pixel arrangement direction. This allows the light-receiving / emitting element 20, the light-emitting element 50G, and the light-emitting element 50B to have a large distance between them, so that the thin films constituting the elements can be formed with a good yield. Furthermore, this configuration allows the pixels to be arranged at a high density, and a display device capable of displaying high-definition images can be realized.

[0094] 7A shows a schematic cross-sectional view of a display device 10d in which the light emitting / receiving element 20 and the light emitting element 50G are arranged side by side. Note that the light emitting element 50B can be configured similarly to the light emitting element 50G, and therefore is not illustrated here.

[0095] For the configuration of the light emitting / receiving element 20, the description of the display device 10 and the like can be cited.

[0096] The light emitting element 50G has a conductive layer 51, an organic layer 52, and a conductive layer 23. The conductive layer 51 functions as a pixel electrode and is electrically connected to a circuit in the element layer 15. The conductive layer 51 is reflective to light emitted by the light emitting element 50G. The conductive layer 51 is preferably located on the same plane as the conductive layer 21 of the light emitting element 20 and is formed by processing the same conductive film. The organic layer 52 is a layer having at least an EL layer. The material of the light emitting layer contained in the EL layer of the organic layer 52 is preferably different from the material of the light emitting layer contained in the EL layer of the organic layer 22 of the light emitting element 20. The conductive layer 23 is used in common to the light emitting element 20 and the light emitting element 50G and functions as a common electrode. The conductive layer 23 has a portion overlapping with the conductive layer 21 through the organic layer 22 and a portion overlapping with the conductive layer 51 through the organic layer 52.

[0097] The color filter 31 is provided so as to surround the light emitting and receiving region of the light emitting and receiving element 20 in a plan view. In Fig. 7A, the color filter 31 is provided so as to overlap a part of the light emitting and receiving element 20. Moreover, the color filter 31 is not provided in the vicinity of the light emitting element 50G.

[0098] FIG. 7B shows a schematic cross-sectional view of a display device 10e provided with a light-shielding layer 32.

[0099] In the display device 10e, the light-shielding layer 32 is provided with openings that overlap with the light-receiving / emitting element 20 and the light-emitting element 50G. The light-shielding layer 32 is also provided so as not to overlap with the light-emitting region of the light-emitting element 50G. This makes it possible to improve the viewing angle characteristics of the light-emitting element 50G even when the adhesive layer 42 is thick.

[0100] FIG. 7C is a schematic cross-sectional view of a display device 10f having a different configuration of a light-shielding layer 32 from that of the display device 10e.

[0101] The display device 10f is an example in which the light-shielding layer 32 is not provided near the light-emitting element 50G. The light-shielding layer 32 is located between the light-receiving / light-emitting element 20 and the light-emitting element 50G in a planar view. Although not shown here, the light-shielding layer 32 can also be configured to be located between the light-receiving / light-emitting element 20 and the light-emitting element 50B in a planar view. The light-shielding layer 32 is not provided between the light-emitting element 50G and the light-emitting element 50B. This can improve the viewing angle characteristics of the light-emitting element 50G (and the light-emitting element 50B).

[0102] In the above, the color filter 31 is disposed only on the light receiving / emitting element 20 side, but color filters may also be disposed on the light emitting element 50G and light emitting element 50B side. A material having translucency to the light emitted by the light emitting element can be used as the color filter disposed overlapping the light emitting element. By disposing the color filter overlapping the light emitting element, the color purity of the light emitted by the light emitting element can be increased, and a display device with high display quality can be realized.

[0103] 8A shows a schematic cross-sectional view of a display device 10g. The display device 10g has a color filter 31G.

[0104] The color filter 31G is provided on the substrate 12 side, similar to the color filter 31. The color filter 31G has a portion that overlaps with the light emitting element 50G in a planar view. Moreover, the color filter 31G is preferably provided so as to encompass the light emitting region of the light emitting element 50G in a planar view.

[0105] The color filter 31G has a function of transmitting light of a color emitted by the light emitting element 50G. For example, when the light emitting element 50G emits green light, a color filter 31G that transmits green light can be used. Similarly, for the light emitting element 50B, a color filter that transmits light of a color emitted by the light emitting element 50B (e.g., blue light) can be used.

[0106] 8A, the display device 10g has an area where the color filter 31G and the color filter 31 overlap between the light receiving / emitting element 20 and the light emitting element 50G in a plan view. In this area, the light of the color emitted by the light receiving / emitting element 20 is absorbed (blocked) by the color filter 31G, and the light of the color emitted by the light emitting element 50G is absorbed (blocked) by the color filter 31. Therefore, the area where the two color filters overlap can function as a light blocking layer.

[0107] 8B shows a schematic cross-sectional view of a display device 10h. The display device 10h differs from the display device 10g mainly in that a color filter 31G has an opening.

[0108] The opening of the color filter 31G can be arranged so as to overlap at least the light emitting region of the light emitting element 50G. The color filter 31G may be arranged so as to overlap the light emitting region of the light emitting element 50G, or the light emitting region of the light emitting element 50G may be located inside the opening of the color filter 31G in a plan view. The positional relationship between the opening of the color filter 31G and the light emitting element 50G may be the same as the positional relationship between the light emitting and receiving region of the light emitting / receiving element 20 and the opening of the color filter 31. The same applies to the light emitting element 50B.

[0109] Also, as in the display device 10i shown in Fig. 8C, a light-shielding layer 32 may be provided. Although Fig. 8C shows an example in which the color filter 31G does not have an opening, the color filter 31G may have an opening like the display device 10h.

[0110] [Configuration example 6] An example of a configuration capable of capturing a higher definition image will be described below.

[0111] 9A is a schematic cross-sectional view of a display device, showing a cross section including the light emitting / receiving element 20 and the light emitting elements 50Ga and 50Gb located on both sides of the light emitting / receiving element 20.

[0112] In FIG. 9A, the width W R The opening 20h of the color filter 31 is located inside the opening 20h. CF is the width W R Less than.

[0113] 9A also shows structures 29a and 29b in contact with the surface of the substrate 12. The structures 29a and 29b reflect and scatter light emitted by the light-emitting elements 50Ga and 50Gb. The structures 29a and 29b are disposed at a distance equal to or less than the distance between the light-receiving / light-emitting element 20 and the light-emitting element 50Ga or the light-emitting element 50Gb.

[0114] As shown in Fig. 9A, a part of the light 30Ga emitted by the light emitting element 50Ga is reflected or scattered by the structure 29a, and a part of it passes through the opening 20h to reach the light receiving / emitting element 20. Similarly, a part of the light 30Gb emitted by the light emitting element 50Gb is reflected or scattered by the structure 29b, and a part of it passes through the opening 20h to reach the light receiving / emitting element 20. That is, both the light reflected (scattered light) by the structure 29a and the light reflected (scattered light) by the structure 29b are incident on the light receiving / emitting element 20. Therefore, as shown in Fig. 9A, it is difficult to clearly image a pattern of a size equal to or smaller than the arrangement interval of the light receiving / emitting elements 20 or the light emitting element 50Ga.

[0115] Therefore, as shown in FIG. 9B, an opening 20h of the color filter 31 is shifted toward one light-emitting element (here, the light-emitting element 50Ga).

[0116] In FIG. 9B, the opening 20h of the color filter 31 is set to a width W R The opening 20h is provided so as to be positioned outside of the light receiving / emitting area of ​​the light receiving / emitting element 20. However, the present invention is not limited to this, and the center of the opening 20h of the color filter 31 may be shifted from the center of the light receiving / emitting area of ​​the light receiving / emitting element 20. Therefore, the opening 20h may be located inside the light receiving / emitting area of ​​the light receiving / emitting element 20, and the opening 20h and the light receiving / emitting area may not overlap with each other.

[0117] 9B, by shifting the opening 20h toward the light emitting element 50Ga, the light 30Gb emitted by the light emitting element 50Gb and reflected or scattered by the structure 29b is absorbed by the color filter 31 and does not reach the light emitting / receiving element 20. On the other hand, a part of the light 30Ga emitted by the light emitting element 50Ga and reflected or scattered by the structure 29a passes through the opening 20h and reaches the light emitting / receiving element 20. In other words, only the reflected light (scattered light) from the structure 29a is incident on the light emitting / receiving element 20.

[0118] In this way, by shifting the center position of the opening 20h of the color filter 31 from the center position of the light receiving / emitting region of the light receiving / emitting element 20 or the center position of the opening of the light blocking layer 32, it is possible to improve the imaging resolution and capture a clear image. In particular, when the ratio of specular reflection components to scattered components of light reflected or scattered from the object to be imaged is high, the improvement in imaging resolution is highly effective.

[0119] The above is a description of the configuration example of the display device.

[0120] The display device according to one embodiment of the present invention is a display device that can realize both display with a high viewing angle characteristic and capturing a clear image. In addition, since the display device according to one embodiment of the present invention can suitably capture images of fingerprints, palm prints, etc., it is possible to add a biometric authentication function such as fingerprint authentication or palm print authentication to an electronic device to which the display device is applied without adding any components, thereby realizing a multifunctional electronic device.

[0121] At least a part of the configuration examples illustrated in this embodiment and the drawings corresponding thereto can be appropriately combined with other configuration examples or drawings.

[0122] This embodiment mode can be implemented by appropriately combining at least a part of it with other embodiment modes described in this specification.

[0123] (Embodiment 2) In this embodiment, a structural example of a display device including a light-emitting element and a light-emitting and light-emitting element according to one embodiment of the present invention will be described.

[0124] A display device according to one embodiment of the present invention includes a light-emitting element and a light-emitting and receiving element.

[0125] The light-receiving / light-emitting element has the functions of both an organic EL element, which is a light-emitting element, and an organic photodiode, which is a light-receiving element. For example, the light-receiving / light-emitting element can be manufactured by adding an active layer that can be used for an organic photodiode to the stacked structure of the organic EL element. Furthermore, when manufacturing the light-receiving / light-emitting element and the light-emitting element, an increase in the number of film formation steps can be suppressed by forming layers that can be used in common by the light-receiving / light-emitting element and the light-emitting element in the same process.

[0126] For example, one of the pair of electrodes (common electrode) can be a layer common to the light-receiving and light-emitting elements and the light-emitting element. For example, it is preferable that at least one of the hole injection layer, the hole transport layer, the electron transport layer, and the electron injection layer is a layer common to the light-receiving and light-emitting elements and the light-emitting element. For example, the light-receiving and light-emitting elements and the light-emitting elements can have the same configuration except for the presence or absence of an active layer. That is, the light-receiving and light-emitting elements can be manufactured by simply adding an active layer to the light-emitting element. In this way, by having a common layer for the light-receiving and light-emitting elements and the light-emitting element, the number of film formations and the number of masks can be reduced, and the manufacturing process and manufacturing cost of the display device can be reduced. In addition, a display device having a light-receiving and light-emitting element can be manufactured by using an existing manufacturing device and manufacturing method for a display device.

[0127] The layers of the light-receiving / light-emitting element may have different functions when the light-receiving / light-emitting element functions as a light-receiving element and when it functions as a light-emitting element. In this specification, components are named based on the functions when the light-receiving / light-emitting element functions as a light-emitting element. For example, the hole injection layer functions as a hole injection layer when the light-receiving / light-emitting element functions as a light-emitting element, and functions as a hole transport layer when the light-receiving / light-emitting element functions as a light-receiving element. Similarly, the electron injection layer functions as an electron injection layer when the light-receiving / light-emitting element functions as a light-emitting element, and functions as an electron transport layer when the light-receiving / light-emitting element functions as a light-receiving element.

[0128] In this manner, the display device of this embodiment has a light-receiving and light-emitting element and a light-emitting element in a display portion. Specifically, the light-receiving and light-emitting elements are arranged in a matrix in the display portion. Therefore, the display portion has one or both of an imaging function and a sensing function in addition to a function of displaying an image.

[0129] The display unit can be used as an image sensor or a touch sensor. That is, by detecting light in the display unit, it is possible to capture an image or to detect an object (such as a finger or a pen) that is in contact with or close to the display unit. Furthermore, in the display device of this embodiment, the light-emitting element can be used as a light source for the sensor. Therefore, it is not necessary to provide a light-receiving unit and a light source separately from the display device, and the number of components of the electronic device can be reduced.

[0130] In the display device of this embodiment, when an object reflects the light emitted by the light-emitting element of the display unit, the light receiving and emitting element can detect the reflected light, making it possible to capture images or detect touch (contact or approach) even in dark places.

[0131] The display device of this embodiment has a function of displaying an image using a light-emitting element and a light-receiving and light-emitting element, that is, the light-emitting element and the light-receiving and light-emitting element function as display elements.

[0132] As the light-emitting element, 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 the light-emitting material contained in the EL element include a material that emits fluorescence (fluorescent material), a material that emits phosphorescence (phosphorescent material), a material that exhibits thermally activated delayed fluorescence (thermally activated delayed fluorescence (TADF) material), an inorganic compound (quantum dot material, etc.), etc. Also, an LED such as a micro LED (Light Emitting Diode) can be used as the light-emitting element.

[0133] The display device of this embodiment has a function of detecting light by 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.

[0134] When the light emitting / receiving element is used in an image sensor, the display device of this embodiment can capture an image using the light emitting / receiving element. For example, the display device of this embodiment can be used as a scanner.

[0135] For example, the function as an image sensor can acquire data such as fingerprints or palm prints. That is, a biometric authentication sensor can be built into the display device of the present embodiment. By building a biometric authentication sensor into the display device, the number of components in the electronic device can be reduced, and the electronic device can be made smaller and lighter, compared to a case where a biometric authentication sensor is provided separately from the display device.

[0136] In addition, by functioning as an image sensor, it is possible to obtain data such as the user's facial expression, eye movement, or change in pupil diameter. By analyzing this data, it is possible to obtain information about the user's mind and body. By changing the output content of one or both of the display and audio based on this information, it is possible to ensure that the user can use the device safely, for example, in VR (Virtual Reality) devices, AR (Augmented Reality) devices, or MR (Mixed Reality) devices.

[0137] When the light emitting / receiving element is used as a touch sensor, the display device of this embodiment can detect the approach or contact of an object by using the light emitting / receiving element.

[0138] The light emitting / receiving element functions as a photoelectric conversion element that detects light incident on the light emitting / receiving element and generates electric charge. The amount of electric charge generated is determined based on the amount of light incident on the light emitting / receiving element.

[0139] The light-receiving and light-emitting element can be fabricated by adding an active layer of a light-receiving element to the above-mentioned light-emitting element. For example, the active layer of a pn-type or pin-type photodiode can be used for the light-receiving and light-emitting element. In particular, it is preferable to use the active layer of an organic photodiode having a layer containing an organic compound for the light-receiving and 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, so they can be applied to various display devices.

[0140] 10A to 10D each show a cross-sectional view of a display device according to one embodiment of the present invention.

[0141] A display device 350A shown in FIG. 10A includes, between a substrate 351 and a substrate 359, a layer 353 having a light emitting / receiving element and a layer 357 having a light emitting element.

[0142] A display device 350B shown in FIG. 10B includes, between a substrate 351 and a substrate 359, a layer 353 having a light emitting / receiving element, a layer 355 having a transistor, and a layer 357 having a light emitting element.

[0143] The display device 350A and the display device 350B have a configuration in which green (G) light and blue (B) light are emitted from the layer 357 having the light-emitting elements, and red (R) light is emitted from the layer 353 having the light-emitting elements. Note that in the display device of one embodiment of the present invention, the color of light emitted from the layer 353 having the light-emitting elements is not limited to red.

[0144] The light emitting / receiving elements included in the layer 353 having the light emitting / receiving elements can detect light incident from the outside of the display device 350A or the display device 350B. The light emitting / receiving elements can detect, for example, one or both of green (G) light and blue (B) light.

[0145] A display device according to an embodiment of the present invention has a plurality of pixels arranged in a matrix. Each pixel has one or more sub-pixels. Each sub-pixel has one light-emitting or light-emitting element. For example, a pixel may have three sub-pixels (three colors: R, G, and B, or three colors: yellow (Y), cyan (C), and magenta (M)) or four sub-pixels (four colors: R, G, B, and white (W), or four colors: R, G, B, and Y). At least one sub-pixel has a light-emitting or light-emitting element. The light-emitting or light-emitting element may be provided in all or some of the pixels. Furthermore, one pixel may have a plurality of light-emitting or light-emitting elements.

[0146] The layer 355 having transistors includes, for example, a transistor electrically connected to a light emitting / receiving element and a transistor electrically connected to a light emitting element. The layer 355 having transistors may further include wirings, electrodes, terminals, capacitors, resistors, and the like.

[0147] The display device of one embodiment of the present invention may have a function of detecting an object such as a finger in contact with the display device ( FIG. 10C ). Alternatively, the display device may have a function of detecting an object approaching (not in contact with) the display device ( FIG. 10D ). For example, as shown in FIGS. 10C and 10D , light emitted by a light-emitting element in a layer 357 having light-emitting elements is reflected by a finger 352 in contact with or approaching the display device 350B, and the light-receiving and light-emitting element in a layer 353 having light-receiving and light-emitting elements detects the reflected light. In this way, it is possible to detect that the finger 352 is in contact with or approaching the display device 350B.

[0148] [Pixels] 10E to 10G and 11A to 11D show examples of pixels. Note that the arrangement of the sub-pixels is not limited to the order shown in the drawings. For example, the positions of the sub-pixels (B) and (G) may be reversed.

[0149] 10E is a striped arrangement, and has a subpixel (MER) that emits red light and has a light receiving function, a subpixel (G) that emits green light, and a subpixel (B) that emits blue light. In a display device in which a pixel is composed of three subpixels of R, G, and B, a light-emitting element used in the R subpixel can be replaced with a light-receiving element to manufacture a display device in which the pixel has a light receiving function.

[0150] 10F is arranged in a matrix and has a subpixel (MER) that emits red light and has a light receiving function, a subpixel (G) that emits green light, a subpixel (B) that emits blue light, and a subpixel (W) that emits white light. Even in a display device in which a pixel is composed of four subpixels, R, G, B, and W, a display device in which the pixel has a light receiving function can be manufactured by replacing the light emitting element used in the R subpixel with a light receiving / emitting element.

[0151] The pixel shown in Fig. 10G is a pixel arranged in a Pentile array, and has sub-pixels that emit two colors of light, the combination of which varies depending on the pixel. The upper left pixel and lower right pixel shown in Fig. 10G have a sub-pixel (MER) that emits red light and has a light receiving function, and a sub-pixel (G) that emits green light. The lower left pixel and upper right pixel shown in Fig. 10G have a sub-pixel (G) that emits green light, and a sub-pixel (B) that emits blue light. Note that the shape of the sub-pixels shown in Fig. 10G indicates the top shape of the light-emitting element or light-receiving / light-emitting element that the sub-pixel has.

[0152] The pixel shown in FIG. 11A has a subpixel (MER) that emits red light and has a light receiving function, a subpixel (G) that emits green light, and a subpixel (B) that emits blue light. The subpixel (MER) is arranged in a column different from the subpixels (G) and (B). The subpixels (G) and (B) are arranged alternately in the same column, with one being arranged in an odd-numbered row and the other being arranged in an even-numbered row. Note that the subpixel arranged in a column different from the subpixels of other colors is not limited to red (R) and may be green (G) or blue (B).

[0153] FIG. 11B shows two pixels, each of which is composed of three subpixels surrounded by dotted lines. The pixel shown in FIG. 11B has a subpixel (MER) that emits red light and has a light receiving function, a subpixel (G) that emits green light, and a subpixel (B) that emits blue light. In the left pixel shown in FIG. 11B, the subpixel (G) is arranged in the same row as the subpixel (MER), and the subpixel (B) is arranged in the same column as the subpixel (MER). In the right pixel shown in FIG. 11B, the subpixel (G) is arranged in the same row as the subpixel (MER), and the subpixel (B) is arranged in the same column as the subpixel (G). In the pixel layout shown in FIG. 11B, the subpixels (MER), (G), and (B) are repeatedly arranged in both odd and even rows, and in each column, subpixels of different colors are arranged in the odd and even rows.

[0154] Fig. 11C is a modified example of the pixel array shown in Fig. 10G. The upper left pixel and the lower right pixel shown in Fig. 11C have a sub-pixel (MER) that emits red light and has a light receiving function, and a sub-pixel (G) that emits green light. The lower left pixel and the upper right pixel shown in Fig. 11C have a sub-pixel (MER) that emits red light and has a light receiving function, and a sub-pixel (B) that emits blue light.

[0155] In FIG. 10G, each pixel is provided with a sub-pixel (G) that emits green light. On the other hand, in FIG. 11C, each pixel is provided with a sub-pixel (MER) that emits red light and has a light receiving function. Since each pixel is provided with a sub-pixel that has a light receiving function, the configuration shown in FIG. 11C can capture images with higher resolution than the configuration shown in FIG. 10G. This can improve the accuracy of biometric authentication, for example.

[0156] The top surface shapes of the light-emitting element and the light-receiving / light-emitting element are not particularly limited, and may be a circle, an ellipse, a polygon, a polygon with rounded corners, etc. With respect to the top surface shape of the light-emitting element of the subpixel (G), Fig. 10G shows an example in which it is a circle, and Fig. 11C shows an example in which it is a square. The top surface shapes of the light-emitting element and the light-receiving / light-emitting element of each color may be different from each other, or may be the same for some or all of the colors.

[0157] The aperture ratios of the sub-pixels of each color may be different from each other, or may be the same for some or all of the colors. For example, the aperture ratio of the sub-pixel (G in FIG. 10G, and MER in FIG. 11C) provided in each pixel may be smaller than the aperture ratios of the sub-pixels of other colors.

[0158] Fig. 11D is a modified example of the pixel array shown in Fig. 11C. Specifically, the configuration in Fig. 11D is obtained by rotating the configuration in Fig. 11C by 45°. Although Fig. 11C has been described as one pixel being made up of two sub-pixels, it can also be considered that one pixel is made up of four sub-pixels as shown in Fig. 11D.

[0159] In FIG. 11D, a description will be given assuming that one pixel is composed of four sub-pixels surrounded by dotted lines. One pixel has two sub-pixels (MER), one sub-pixel (G), and one sub-pixel (B). In this way, one pixel has a plurality of sub-pixels having a light receiving function, so that imaging can be performed with high resolution. This makes it possible to improve the accuracy of biometric authentication. For example, the resolution of imaging can be set to the root double of the resolution of display.

[0160] A display device to which the configuration shown in FIG. 11C or FIG. 11D is applied has p (p is an integer of 2 or more) first light-emitting elements, q (q is an integer of 2 or more) 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 elements 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.

[0161] For example, when touch detection is performed using a light receiving / emitting element, it is preferable that the light emitted from the light source is difficult for a user to see. Since blue light is less visible than green light, it is preferable that a light emitting element that emits blue light is used as the light source. Therefore, it is preferable that the light receiving / emitting element has a function of receiving blue light.

[0162] As described above, pixels with various arrangements can be applied to the display device of one embodiment of the present invention.

[0163] In the display device of this embodiment, since there is no need to change the pixel arrangement in order to incorporate a light-receiving function into the pixel, it is possible to add an imaging function and / or a sensing function to the display portion without reducing the aperture ratio and the resolution.

[0164] [Light emitting / receiving element] 12A to 12E show examples of the layered structure of the light emitting / receiving element.

[0165] The light emitting / receiving element has at least an active layer and a light emitting layer between a pair of electrodes.

[0166] The light-emitting element may further include a layer containing a substance with high hole-injection properties, a substance with high hole-transport properties, a substance with high hole-blocking properties, a substance with high electron-transport properties, a substance with high electron-injection properties, a substance with high electron-blocking properties, or a bipolar substance (a substance with high electron-transport properties and high hole-transport properties) as a layer other than the active layer and the light-emitting layer.

[0167] 12A to 12C each have a first electrode 180, a hole injection layer 181, a hole transport layer 182, an active layer 183, a light emitting layer 193, an electron transport layer 184, an electron injection layer 185, and a second electrode 189.

[0168] The first electrode 180 functions as an anode (positive electrode) of the light emitting / receiving element, and the second electrode 189 functions as a cathode (negative electrode) of the light emitting / receiving element.

[0169] 12A to 12C can be considered to have a configuration in which the active layer 183 is added to the light-emitting element. Therefore, the light-emitting element can be formed in parallel with the formation of the light-emitting element by simply adding a process of forming the active layer 183 to the manufacturing process of the light-emitting element. Furthermore, the light-emitting element and the light-emitting 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 section without significantly increasing the number of manufacturing processes.

[0170] The stacking order of the light emitting layer 193 and the active layer 183 is not limited. Fig. 12A shows an example in which the active layer 183 is provided on the hole transport layer 182, and the light emitting layer 193 is provided on the active layer 183. Fig. 12B shows an example in which the light emitting layer 193 is provided on the hole transport layer 182, and the active layer 183 is provided on the light emitting layer 193. The active layer 183 and the light emitting layer 193 may be in contact with each other as shown in Figs. 12A and 12B.

[0171] As shown in Fig. 12C, it is preferable that a buffer layer is sandwiched between the active layer 183 and the light-emitting layer 193. As the buffer layer, at least one layer selected from a hole injection layer, a hole transport layer, an electron transport layer, an electron injection layer, a hole blocking layer, an electron blocking layer, and the like can be used. Fig. 12C shows an example in which a hole transport layer 182 is used as the buffer layer.

[0172] By providing a buffer layer between the active layer 183 and the light emitting layer 193, it is possible to suppress the transfer of excitation energy from the light emitting layer 193 to the active layer 183. In addition, the buffer layer can be used to adjust the optical path length (cavity length) of the microresonant (microcavity) structure. Therefore, a light emitting / receiving element having a buffer layer between the active layer 183 and the light emitting layer 193 can obtain high light emitting efficiency.

[0173] 12A to 12C in that it does not have a hole transport layer 182. The light emitting / receiving element may not have at least one layer among the hole injection layer 181, the hole transport layer 182, the electron transport layer 184, and the electron injection layer 185. The light emitting / receiving element may also have other functional layers, such as a hole blocking layer or an electron blocking layer.

[0174] The light emitting / receiving element shown in FIG. 12E differs from the light emitting / receiving element shown in FIGS. 12A to 12D in that it does not have active layer 183 and light emitting layer 193, but has layer 186 that serves as both a light emitting layer and an active layer.

[0175] As the layer 186 serving as both the light-emitting layer and the active layer, for example, a layer containing three materials: an n-type semiconductor that can be used in the active layer 183, a p-type semiconductor that can be used in the active layer 183, and a light-emitting substance that can be used in the light-emitting layer 193 can be used.

[0176] Furthermore, it is preferable that the absorption band on the lowest energy side of the absorption spectrum of the mixed material of n-type semiconductor and p-type semiconductor does not overlap with the maximum peak of the emission spectrum (PL spectrum) of the luminescent substance, and it is more preferable that they are sufficiently separated from each other.

[0177] In the light receiving / emitting element, a conductive film that transmits visible light is used for the electrode from which light is extracted, and a conductive film that reflects visible light is preferably used for the electrode from which light is not extracted.

[0178] When the light emitting / receiving element is driven as a light emitting element, the hole injection layer is a layer that injects holes from the anode to the light emitting / receiving element. The hole injection layer is a layer containing a material with high hole injection properties. As the material with high hole injection properties, a composite material containing a hole transport material and an acceptor material (electron accepting material), an aromatic amine compound, or the like can be used.

[0179] When the light emitting / receiving element is operated as 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. When the light emitting / receiving element is operated as 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 density of 1×10 -6 cm 2 A material having a hole mobility of 100 / Vs or more is preferable. Note that other materials 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, a furan derivative, etc.) or an aromatic amine (a compound having an aromatic amine skeleton) is preferable.

[0180] When the light emitting / receiving element is operated as 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. When the light emitting / receiving element is operated as 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, for example, 1×10 -6 cm 2 A material having an electron mobility of 100 / Vs or more is preferable. Note that, other materials may be used as long as they have a higher electron transporting property than holes. As the electron transporting material, a material having a high electron transporting property may be used, such as a metal complex having a quinoline skeleton, a metal complex having a benzoquinoline skeleton, a metal complex having an oxazole skeleton, a metal complex having a thiazole skeleton, an oxadiazole derivative, a triazole derivative, an imidazole derivative, an oxazole derivative, a thiazole derivative, a phenanthroline derivative, a quinoline derivative having a quinoline ligand, a benzoquinoline derivative, a quinoxaline derivative, a dibenzoquinoxaline derivative, a pyridine derivative, a bipyridine derivative, a pyrimidine derivative, and other π-electron deficient heteroaromatic compounds including nitrogen-containing heteroaromatic compounds.

[0181] When the light emitting / receiving element is driven as a light emitting element, the electron injection layer is a layer that injects electrons from the cathode to the light emitting / receiving element. The electron injection layer is a layer containing a material with high electron injection properties. As the material with high electron injection properties, an alkali metal, an alkaline earth metal, or a compound thereof can be used. As the material with high electron injection properties, a composite material containing an electron transport material and a donor material (electron donor material) can also be used.

[0182] The light-emitting layer 193 is a layer containing a light-emitting substance. The light-emitting layer 193 can have one or more types of light-emitting substances. As the light-emitting substance, a substance that emits light of a color such as blue, purple, blue-purple, green, yellow-green, yellow, orange, or red is appropriately used. In addition, a substance that emits near-infrared light can also be used as the light-emitting substance.

[0183] Examples of the light-emitting material include fluorescent materials, phosphorescent materials, TADF materials, and quantum dot materials.

[0184] 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.

[0185] Examples of phosphorescent materials include organometallic complexes (particularly iridium complexes) having a 4H-triazole skeleton, 1H-triazole skeleton, imidazole skeleton, pyrimidine skeleton, pyrazine skeleton, or 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.

[0186] The light-emitting layer 193 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 may be used. In addition, as the one or more organic compounds, a bipolar material or a TADF material may be used.

[0187] The light-emitting layer 193 preferably includes, for example, a phosphorescent material, and a hole-transporting material and an electron-transporting material that are a combination that easily forms an exciplex. With this structure, light emission can be efficiently obtained using ExTET (Exciplex-Triplet Energy Transfer), 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 and light emission can be efficiently obtained. With this structure, high efficiency, low voltage operation, and long life of the light-emitting element can be simultaneously achieved.

[0188] 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 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) measurement.

[0189] The formation of an exciplex can be confirmed, for example, by comparing the emission spectrum of a hole transport material, the emission spectrum of an electron transport material, and the emission spectrum of a mixed film obtained by mixing these materials, and observing the phenomenon that the emission spectrum of the mixed film shifts to a longer wavelength than the emission spectrum 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 a hole transport material, the transient PL of an electron transport material, and the transient PL of a mixed film obtained by mixing these materials, and observing the difference in transient response, such as the transient PL lifetime of the mixed film having a longer lifetime component than the transient PL lifetime of each material, or the proportion of delayed components becoming larger. In addition, the above-mentioned transient PL may be read as transient electroluminescence (EL). In other words, the formation of an exciplex can also be confirmed by comparing the transient EL of a hole transport material, the transient EL of a material having electron transport properties, and the transient EL of a mixed film obtained by mixing these materials, and observing the difference in transient response.

[0190] The active layer 183 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 of the active layer is shown. By using an organic semiconductor, the light-emitting layer 193 and the active layer 183 can be formed by the same method (for example, a vacuum deposition method), which is preferable because a common manufacturing device can be used.

[0191] The active layer 183 is made of an n-type semiconductor material such as fullerene (e.g., C 60 , C 70Examples of electron-accepting organic semiconductor materials include organic semiconductor materials such as fullerene derivatives, etc. Fullerenes have a shape like a soccer ball, and this shape is energetically stable. Fullerenes have deep (low) HOMO and LUMO levels. Fullerenes have extremely high electron-accepting (acceptor) properties because of their deep LUMO level. Normally, when π-electron conjugation (resonance) spreads on a plane, as in benzene, electron-donating (donor) properties are high, but fullerenes have a spherical shape, so they have high electron-accepting properties despite the large spread of π-electrons. High electron-accepting properties are useful as light-receiving elements because they cause charge separation quickly and efficiently. C 60 , C 70 Both have a wide absorption band in the visible light region, especially C 70 is C 60 It is preferred because it has a larger π-electron conjugated system and a broad absorption band in the long wavelength region as compared to the above.

[0192] Furthermore, 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.

[0193] Examples of the p-type semiconductor material of the active layer 183 include electron-donating organic semiconductor materials such as copper (II) phthalocyanine (CuPc), tetraphenyldibenzoperiflanthene (DBP), zinc phthalocyanine (ZnPc), tin phthalocyanine (SnPc), and quinacridone.

[0194] 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, tetracene 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, polyphenylenevinylene derivatives, polyparaphenylene derivatives, polyfluorene derivatives, polyvinylcarbazole derivatives, and polythiophene derivatives.

[0195] 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.

[0196] It is preferable to use a spherical fullerene as the electron-accepting organic semiconductor material, and an organic semiconductor material with a nearly planar shape as the electron-donating organic semiconductor material. Molecules with similar shapes tend to gather together, and when molecules of the same type aggregate, the energy levels of the molecular orbitals are close to each other, which can increase the carrier transportability.

[0197] For example, the active layer 183 is preferably formed by co-evaporation of an n-type semiconductor and a p-type semiconductor.

[0198] The layer 186 serving as both a light emitting layer and an active layer is preferably formed using the above-mentioned light emitting material, n-type semiconductor, and p-type semiconductor.

[0199] The hole injection layer 181, the hole transport layer 182, the active layer 183, the light emitting layer 193, the electron transport layer 184, the electron injection layer 185, and the layer serving as both the light emitting layer and the active layer 186 may be made of either a low molecular weight compound or a high molecular weight compound, and may contain an inorganic compound. Each layer may be formed by a method such as a deposition method (including a vacuum deposition method), a transfer method, a printing method, an inkjet method, or a coating method.

[0200] Each layer constituting the light-emitting or light-emitting element can have a single-layer structure containing a single material (compound), a single-layer structure containing multiple materials, a laminate structure in which layers containing two or more single materials are stacked, a laminate structure in which layers containing two or more multiple materials are stacked, or a laminate structure in which a layer containing one or more single materials and a layer containing one or more multiple materials are stacked. When a layer containing multiple materials is formed by vacuum deposition, either a co-deposition method in which two or more materials are evaporated or sublimated to form a film, or a premix method in which a mixed material in which two or more materials are mixed in advance is evaporated or sublimated to form a film, may be used. Alternatively, a layer containing three or more materials may be formed by combining the co-deposition method and the premix method.

[0201] A detailed structure of a light-emitting element and a light-emitting element included in a display device of one embodiment of the present invention will be described below with reference to FIGS. 13A to 15B.

[0202] 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 the substrate on which a light-emitting element is formed, and a dual emission type that emits light to both sides.

[0203] 13A to 15B, a top emission type display device will be described as an example.

[0204] [Configuration example 1] The display device shown in Figures 13A and 13B has, on a substrate 151, a light-emitting element 347B that emits blue (B) light, a light-emitting element 347G that emits green (G) light, and a light-receiving element 347MER that emits red (R) light and has a light-receiving function, via a layer 355 having a transistor.

[0205] Fig. 13A shows a case where the light emitting / receiving element 347MER functions as a light emitting element. Fig. 13A shows an example where the light emitting element 347B emits blue light, the light emitting element 347G emits green light, and the light emitting / receiving element 347MER emits red light.

[0206] Fig. 13B shows a case where the light receiving / emitting element 347MER functions as a light receiving element. Fig. 13B shows an example where the light receiving / emitting element 347MER detects blue light emitted by the light emitting element 347B and green light emitted by the light emitting element 347G.

[0207] Each of the light emitting element 347B, the light emitting element 347G, and the light emitting / receiving element 347MER has a pixel electrode 191 and a common electrode 115. In this embodiment, a case will be described as an example in which the pixel electrode 191 functions as an anode and the common electrode 115 functions as a cathode.

[0208] In this embodiment, the pixel electrode 191 functions as an anode and the common electrode 115 functions as a cathode in the light receiving / emitting element 347MER, similarly to the light emitting element. In other words, the light receiving / emitting element 347MER is driven by applying a reverse bias between the pixel electrode 191 and the common electrode 115, so that the light receiving / emitting element 347MER can detect light incident on the light receiving / emitting element 347MER, generate electric charges, and extract the electric charges as a current.

[0209] The common electrode 115 is used in common by the light emitting element 347B, the light emitting element 347G, and the light emitting / receiving element 347MER.

[0210] The materials and thicknesses of the pairs of electrodes of the light-emitting element 347B, the light-emitting element 347G, and the light-receiving and light-emitting element 347MER can be made the same, which leads to reduction in manufacturing cost and simplification of the manufacturing process of the display device.

[0211] The configuration of the display device shown in FIGS. 13A and 13B will be specifically described.

[0212] The light-emitting element 347B has a buffer layer 192B, a light-emitting layer 193B, and a buffer layer 194B in this order over a pixel electrode 191. The light-emitting layer 193B contains a light-emitting material that emits blue light. The light-emitting element 347B has a function of emitting blue light.

[0213] The light-emitting element 347G has a buffer layer 192G, a light-emitting layer 193G, and a buffer layer 194G in this order on a pixel electrode 191. The light-emitting layer 193G contains a light-emitting material that emits green light. The light-emitting element 347G has a function of emitting green light.

[0214] The light emitting / receiving element 347MER has a buffer layer 192R, an active layer 183, a light emitting layer 193R, and a buffer layer 194R in this order on the pixel electrode 191. The light emitting layer 193R has a light emitting material that emits red light. The active layer 183 has an organic compound that absorbs light of a shorter wavelength than red light (for example, one or both of green light and blue light). The active layer 183 may use an organic compound that absorbs not only visible light but also ultraviolet light. The light emitting / receiving element 347MER has a function of emitting red light. The light emitting / receiving element 347MER has a function of detecting the emission of at least one of the light emitting elements 347G and 347B, and preferably has a function of detecting the emission of both of them.

[0215] The active layer 183 preferably contains an organic compound that does not easily absorb red light and absorbs light with a shorter wavelength than red light. This allows the light receiving / emitting element 347MER to have a function of efficiently emitting red light and a function of accurately detecting light with a shorter wavelength than red light. For example, it is preferable to select a material for the active layer 183 so that the absorption spectrum of the organic compound contained in the active layer 183 does not overlap with the emission spectrum of the light emitting material contained in the light emitting layer 193R.

[0216] The pixel electrode 191, the buffer layer 192R, the buffer layer 192G, the buffer layer 192B, the active layer 183, the light-emitting layer 193R, the light-emitting layer 193G, the light-emitting layer 193B, the buffer layer 194R, the buffer layer 194G, the buffer layer 194B, and the common electrode 115 may each have a single layer structure or a laminated structure.

[0217] In the display device shown in FIGS. 13A and 13B, the buffer layer, active layer, and light-emitting layer are layers that are fabricated separately for each element.

[0218] The buffer layer 192R, the buffer layer 192G, and the buffer layer 192B may each have one or both of a hole injection layer and a hole transport layer. Furthermore, the buffer layer 192R, the buffer layer 192G, and the buffer layer 192B may have an electron blocking layer. The buffer layer 194B, the buffer layer 194G, and the buffer layer 194R may each have one or both of an electron injection layer and an electron transport layer. Furthermore, the buffer layer 194R, the buffer layer 194G, and the buffer layer 194B may have a hole blocking layer. Note that for the materials of each layer constituting the light emitting element, the above description of each layer constituting the light emitting element can be referred to.

[0219] [Configuration example 2] 14A and 14B, the light-emitting element 347B, the light-emitting element 347G, and the light-receiving / light-emitting element 347MER may have a common layer between a pair of electrodes, which allows the light-receiving / light-emitting element to be built into the display device without significantly increasing the number of manufacturing steps.

[0220] The light emitting element 347B, the light emitting element 347G, and the light emitting / receiving element 347MER shown in FIG. 14A have a common layer 112 and a common layer 114 in addition to the configurations shown in FIGS. 13A and 13B.

[0221] The light-emitting element 347B, the light-emitting element 347G, and the light-receiving element 347MER shown in Figure 14B differ from the configurations shown in Figures 13A and 13B in that they do not have buffer layers 192R, 192G, 192B and buffer layers 194R, 194G, 194B, but have common layers 112 and 114.

[0222] The common layer 112 may include one or both of a hole injection layer and a hole transport layer, and the common layer 114 may include one or both of an electron injection layer and an electron transport layer.

[0223] Each of the common layer 112 and the common layer 114 may have a single-layer structure or a laminated structure.

[0224] [Configuration example 3] The display device shown in FIG. 15A is an example in which the laminated structure shown in FIG. 12C is applied to a light emitting / receiving element 347MER.

[0225] The light emitting / receiving element 347MER has, on a pixel electrode 191, a hole injection layer 181, an active layer 183, a hole transport layer 182R, a light emitting layer 193R, an electron transport layer 184, an electron injection layer 185, and a common electrode 115 in this order.

[0226] The hole injection layer 181, the electron transport layer 184, the electron injection layer 185, and the common electrode 115 are layers common to the light emitting element 347G and the light emitting element 347B.

[0227] The light emitting element 347G has, on a pixel electrode 191, a hole injection layer 181, a hole transport layer 182G, a light emitting layer 193G, an electron transport layer 184, an electron injection layer 185, and a common electrode 115 in this order.

[0228] The light emitting element 347B has, on the pixel electrode 191, a hole injection layer 181, a hole transport layer 182B, a light emitting layer 193B, an electron transport layer 184, an electron injection layer 185, and a common electrode 115 in this order.

[0229] It is preferable that a microcavity structure is applied to the light-emitting element of the display device of this embodiment. Furthermore, it is preferable that a microcavity structure is also applied to the light-receiving / light-emitting element. Therefore, one of a pair of electrodes of the light-emitting element or the light-receiving / light-emitting element is preferably an electrode having transparency and reflectivity to visible light (semi-transmissive / semi-reflective electrode), and the other is preferably an electrode having reflectivity to visible light (reflective electrode). When the light-emitting element and the light-receiving / light-emitting element have a microcavity structure, light emitted from the light-emitting layer can be resonated between both electrodes, and the light emitted from the light-emitting element or the light-receiving / light-emitting element can be strengthened.

[0230] The semi-transmitting / semi-reflective electrode may have a laminated structure of a reflective electrode and an electrode that is transparent to visible light (also called a transparent electrode). In this specification, the reflective electrode, which functions as a part of the semi-transmitting / semi-reflective electrode, may be referred to as a pixel electrode or a common electrode, and the transparent electrode may be referred to as an optical adjustment layer, but the transparent electrode (optical adjustment layer) may also function as a pixel electrode or a common electrode.

[0231] The light transmittance of the transparent electrode is 40% or more. For example, it is preferable to use an electrode for the light emitting element that has a transmittance of 40% or more for both visible light (light with a wavelength of 400 nm or more and less than 750 nm) and near-infrared light (light with a wavelength of 750 nm or more and 1300 nm or less). The reflectance of the semi-transparent / semi-reflective electrode for both visible light and near-infrared light is 10% or more and 95% or less, preferably 30% or more and 80% or less. The reflectance of the reflective electrode for both visible light and near-infrared light is 40% or more and 100% or less, preferably 70% or more and 100% or less. The resistivity of these electrodes is 1×10 -2 Ωcm or less is preferable.

[0232] The hole transport layer 182B, the hole transport layer 182G, and the hole transport layer 182R may each have a function as an optical adjustment layer. Specifically, in the light emitting element 347B, it is preferable to adjust the thickness of the hole transport layer 182B so that the optical distance between the pair of electrodes is an optical distance that strengthens blue light. Similarly, in the light emitting element 347G, it is preferable to adjust the thickness of the hole transport layer 182G so that the optical distance between the pair of electrodes is an optical distance that strengthens green light. And, in the light receiving / emitting element 347MER, it is preferable to adjust the thickness of the hole transport layer 182R so that the optical distance between the pair of electrodes is an optical distance that strengthens red light. The layer used as the optical adjustment layer is not limited to the hole transport layer. In addition, when the semi-transmitting / semi-reflective electrode has a laminated structure of a reflective electrode and a transparent electrode, the optical distance between the pair of electrodes indicates the optical distance between the pair of reflective electrodes.

[0233] [Configuration example 4] The display device shown in FIG. 15B is an example in which the laminated structure shown in FIG. 12D is applied to a light emitting / receiving element 347MER.

[0234] The light emitting / receiving element 347MER has, on a pixel electrode 191, a hole injection layer 181, an active layer 183, a light emitting layer 193R, an electron transport layer 184, an electron injection layer 185, and a common electrode 115 in this order.

[0235] The hole injection layer 181, the electron transport layer 184, the electron injection layer 185, and the common electrode 115 are layers common to the light emitting element 347G and the light emitting element 347B.

[0236] The light emitting element 347G has, on a pixel electrode 191, a hole injection layer 181, a hole transport layer 182G, a light emitting layer 193G, an electron transport layer 184, an electron injection layer 185, and a common electrode 115 in this order.

[0237] The light emitting element 347B has, on the pixel electrode 191, a hole injection layer 181, a hole transport layer 182B, a light emitting layer 193B, an electron transport layer 184, an electron injection layer 185, and a common electrode 115 in this order.

[0238] The hole transport layer is provided in the light emitting element 347G and the light emitting element 347B, but not in the light emitting / receiving element 347MER. In this way, in addition to the active layer and the light emitting layer, a layer may be provided only in one of the light emitting element and the light emitting / receiving element.

[0239] A detailed configuration of a display device according to one embodiment of the present invention will be described below with reference to FIGS.

[0240] [Display device 310A] 16A and 16B show cross-sectional views of the display device 310A.

[0241] The display device 310A includes a light emitting element 190B, a light emitting element 190G, and a light receiving / emitting element 190MER.

[0242] The light emitting element 190B has a pixel electrode 191, a buffer layer 192B, a light emitting layer 193B, a buffer layer 194B, and a common electrode 115. The light emitting element 190B has a function of emitting blue light 321B.

[0243] The light emitting element 190G has a pixel electrode 191, a buffer layer 192G, a light emitting layer 193G, a buffer layer 194G, and a common electrode 115. The light emitting element 190G has a function of emitting green light 321G.

[0244] The light emitting / receiving element 190MER has a pixel electrode 191, a buffer layer 192R, an active layer 183, a light emitting layer 193R, a buffer layer 194R, and a common electrode 115. The light emitting / receiving element 190MER has a function of emitting red light 321R and a function of detecting light 322.

[0245] Fig. 16A shows a case where the light emitting / receiving element 190MER functions as a light emitting element. Fig. 16A shows an example where the light emitting element 190B emits blue light, the light emitting element 190G emits green light, and the light emitting / receiving element 190MER emits red light.

[0246] Fig. 16B shows a case where the light receiving / emitting element 190MER functions as a light receiving element. Fig. 16B shows an example where the light receiving / emitting element 190MER detects blue light emitted by the light emitting element 190B and green light emitted by the light emitting element 190G.

[0247] The pixel electrode 191 is located on the insulating layer 214. Ends of the pixel electrode 191 are covered with partition walls 216. Two adjacent pixel electrodes 191 are electrically insulated from each other by the partition wall 216 (also referred to as being electrically separated).

[0248] An organic insulating film is suitable for the partition 216. Materials that can be used for the organic insulating film include acrylic resin, polyimide resin, epoxy resin, polyamide resin, polyimideamide resin, siloxane resin, benzocyclobutene resin, phenol resin, and precursors of these resins. The partition 216 is a layer that transmits visible light. Instead of the partition 216, a partition that blocks visible light may be provided.

[0249] The display device 310A has a light emitting / receiving element 190MER, a light emitting element 190G, a light emitting element 190B, a transistor 342, and the like between a pair of substrates (substrate 151 and substrate 152).

[0250] The light receiving / emitting element 190MER has a function of detecting light. Specifically, the light receiving / emitting element 190MER functions as a photoelectric conversion element that receives light 322 incident from the outside of the display device 310A and converts it into an electrical signal. The light 322 can also be said to be light emitted by one or both of the light emitting element 190G and the light emitting element 190B and reflected by an object. The light 322 may also be incident on the light receiving / emitting element 190MER via a lens.

[0251] The light receiving / emitting element 190MER, the light emitting element 190G, and the light emitting element 190B have a function of emitting visible light. Specifically, the light receiving / emitting element 190MER, the light emitting element 190G, and the light emitting element 190B function as an electroluminescent element that emits light toward the substrate 152 side by applying a voltage between the pixel electrode 191 and the common electrode 115 (see light 321R, light 321G, and light 321B).

[0252] The buffer layer 192, the light-emitting layer 193, and the buffer layer 194 can also be called organic layers (layers containing an organic compound) or EL layers. The pixel electrode 191 preferably has a function of reflecting visible light. The common electrode 115 has a function of transmitting visible light.

[0253] The pixel electrode 191 is electrically connected to a source or a drain of the transistor 342 through an opening provided in the insulating layer 214. The transistor 342 has a function of controlling driving of a light-emitting element or a light-emitting / receiving element.

[0254] At least a part of the circuit electrically connected to the light receiving / emitting element 190MER is preferably formed of the same material and in the same process as the circuit electrically connected to the light emitting element 190G and the light emitting element 190B. This allows the thickness of the display device to be thinner and the manufacturing process to be simplified compared to the case where the two circuits are formed separately.

[0255] Each of the light emitting / receiving element 190MER, the light emitting element 190G, and the light emitting element 190B is preferably covered with a protective layer 195. In Fig. 16A and other figures, the protective layer 195 is provided in contact with the common electrode 115. Providing the protective layer 195 can prevent impurities from entering the light emitting / receiving element 190MER and the light emitting elements of each color, and can improve the reliability of the light emitting / receiving element 190MER and the light emitting elements of each color. In addition, the protective layer 195 and the substrate 152 are bonded together by the adhesive layer 142.

[0256] A light-shielding layer BM is provided on the surface of the substrate 152 facing the substrate 151. The light-shielding layer BM has openings at positions overlapping the light-emitting element 190G and the light-emitting element 190B, and at a position overlapping the light-receiving / light-emitting element 190MER. In this specification and the like, the position overlapping with the light-emitting element 190G or the light-emitting element 190B specifically refers to a position overlapping with the light-emitting region of the light-emitting element 190G or the light-emitting element 190B. Similarly, the position overlapping with the light-receiving / light-emitting element 190MER specifically refers to a position overlapping with the light-emitting region and the light-receiving region of the light-receiving / light-emitting element 190MER.

[0257] As shown in FIG. 16B, the light receiving / emitting element 190MER can detect the light emitted by the light emitting element 190G or the light emitting element 190B reflected by the object. However, the light emitted by the light emitting element 190G or the light emitting element 190B may be reflected in the display device 310A and may enter the light receiving / emitting element 190MER without passing through the object. The light shielding layer BM can suppress the influence of such stray light. For example, if the light shielding layer BM is not provided, the light 323 emitted by the light emitting element 190G may be reflected by the substrate 152, and the reflected light 324 may enter the light receiving / emitting element 190MER. By providing the light shielding layer BM, it is possible to suppress the reflected light 324 from entering the light receiving / emitting element 190MER. This reduces noise and increases the sensitivity of the sensor using the light receiving / emitting element 190MER.

[0258] The light-shielding layer BM may be made of a material that blocks light emitted from the light-emitting element. The light-shielding layer BM preferably absorbs visible light. For example, the light-shielding layer BM may be made of a black matrix using a metal material, or a resin material containing a pigment (such as carbon black) or a dye. The light-shielding layer BM may have a laminated structure of a red color filter, a green color filter, and a blue color filter.

[0259] A color filter CF is provided on the surface of the substrate 152 facing the substrate 151. The color filter CF has a portion located inside an opening of the light-shielding layer BM that overlaps with the light-receiving / light-emitting element 190MER in a plan view. The color filter CF also has an opening at a position that overlaps with the light-receiving / light-emitting element 190MER. The color filter CF has a function of transmitting light 321R emitted by the light-receiving / light-emitting element 190MER and blocking (absorbing or reflecting) light 321G emitted by the light-emitting element 190G and light 321B emitted by the light-emitting element 190B.

[0260] [Display device 310B] 17A is different from the display device 310A in that the light emitting element 190G, the light emitting element 190B, and the light emitting / receiving element 190MER do not have the buffer layer 192 and the buffer layer 194, but have the common layer 112 and the common layer 114, respectively. Note that in the following description of the display device, description of the same configuration as the display device described above may be omitted.

[0261] The layered structure of the light emitting element 190B, the light emitting element 190G, and the light emitting / receiving element 190MER is not limited to the configuration shown in the display devices 310A and 310B. For example, the layered structures shown in Figures 12A to 15B can be appropriately applied to each element.

[0262] [Display device 310C] A display device 310C shown in FIG. 17B differs from the display device 310B in that it does not have the substrates 151 and 152, but has the substrates 153 and 154, the adhesive layer 155, and the insulating layer 212.

[0263] The substrate 153 and the insulating layer 212 are bonded together by an adhesive layer 155. The substrate 154 and the protective layer 195 are bonded together by an adhesive layer 142.

[0264] The display device 310C is fabricated by transferring the insulating layer 212, the transistor 342, the light emitting / receiving element 190MER, the light emitting element 190G, and the light emitting element 190B, which are formed on a fabrication substrate, onto the substrate 153. The substrates 153 and 154 are preferably flexible. This can increase the flexibility of the display device 310C. For example, the substrates 153 and 154 are preferably made of resin.

[0265] The substrates 153 and 154 may each 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, etc.), 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, etc. One or both of the substrates 153 and 154 may be made of glass having a thickness sufficient to provide flexibility.

[0266] The substrate of the display device of this embodiment may be a film having high optical isotropy, such as a triacetyl cellulose (TAC, also called cellulose triacetate) resin film, a cycloolefin polymer (COP) film, a cycloolefin copolymer (COC) film, an acrylic resin film, or the like.

[0267] A more detailed structure of the display device of one embodiment of the present invention will be described below.

[0268] [Display device 100A] FIG. 18 shows a perspective view of the display device 100A, and FIG. 19 shows a cross-sectional view of the display device 100A.

[0269] The display device 100A has a configuration in which a substrate 152 and a substrate 151 are bonded together. In Fig. 18, the substrate 152 is indicated by a dashed line.

[0270] The display device 100A has a display unit 162, a circuit 164, wiring 165, etc. Fig. 18 shows an example in which an IC (integrated circuit) 173 and an FPC 172 are mounted on the display device 100A. Therefore, the configuration shown in Fig. 18 can also be said to be a display module having the display device 100A, an IC, and an FPC.

[0271] The circuit 164 can be, for example, a scanning line driver circuit.

[0272] The wiring 165 has a function of supplying signals and power to the display portion 162 and the circuit 164. The signals and power are input to the wiring 165 from the outside via the FPC 172 or are input to the wiring 165 from the IC 173.

[0273] 18 shows an example in which an IC 173 is provided on a substrate 151 by a chip on glass (COG) method or a chip on film (COF) method. For example, an IC having a scanning line driving circuit or a signal line driving circuit can be used as the IC 173. Note that the display device 100A and the display module may be configured without an IC. Also, the IC may be mounted on an FPC by a COF method or the like.

[0274] Figure 19 shows an example of a cross section of the display device 100A shown in Figure 18, cutting a portion of the area including the FPC 172, a portion of the area including the circuit 164, a portion of the area including the display unit 162, and a portion of the area including the end portion.

[0275] A display device 100A shown in FIG. 19 includes, between a substrate 151 and a substrate 152, a transistor 201, a transistor 205, a transistor 206, a transistor 207, a light-emitting element 190B, a light-emitting element 190G, a light-emitting element 190MER, and the like.

[0276] The substrate 152 and the insulating layer 214 are bonded via an adhesive layer 142. A solid sealing structure or a hollow sealing structure can be applied to seal the light emitting element 190B, the light emitting element 190G, and the light receiving / emitting element 190MER. In FIG. 19, the space 143 surrounded by the substrate 152, the adhesive layer 142, and the insulating layer 214 is filled with an inert gas (nitrogen or argon, etc.), and a hollow sealing structure is applied. The adhesive layer 142 may be provided overlapping the light emitting element 190B, the light emitting element 190G, and the light receiving / emitting element 190MER. In addition, the space 143 surrounded by the substrate 152, the adhesive layer 142, and the insulating layer 214 may be filled with a resin different from the adhesive layer 142.

[0277] The light-emitting element 190B has a layered structure in which a pixel electrode 191, a common layer 112, a light-emitting layer 193B, a common layer 114, and a common electrode 115 are layered in this order from the insulating layer 214 side. The pixel electrode 191 is connected to a conductive layer 222b of the transistor 207 through an opening provided in the insulating layer 214. The transistor 207 has a function of controlling driving of the light-emitting element 190B. An end of the pixel electrode 191 is covered with a partition wall 216. The pixel electrode 191 contains a material that reflects visible light, and the common electrode 115 contains a material that transmits visible light.

[0278] The light-emitting element 190G has a layered structure in which a pixel electrode 191, a common layer 112, a light-emitting layer 193G, a common layer 114, and a common electrode 115 are layered in this order from the insulating layer 214 side. The pixel electrode 191 is connected to a conductive layer 222b of the transistor 206 through an opening provided in the insulating layer 214. The transistor 206 has a function of controlling driving of the light-emitting element 190G.

[0279] The light emitting / receiving element 190MER has a layered structure in which a pixel electrode 191, a common layer 112, an active layer 183, a light emitting layer 193R, a common layer 114, and a common electrode 115 are layered in this order from the insulating layer 214 side. The pixel electrode 191 is electrically connected to a conductive layer 222b of the transistor 205 through an opening provided in the insulating layer 214. The transistor 205 has a function of controlling the driving of the light emitting / receiving element 190MER.

[0280] Light emitted by the light emitting element 190B, the light emitting element 190G, and the light receiving / emitting element 190MER is emitted toward the substrate 152. Light is incident on the light receiving / emitting element 190MER through the substrate 152 and the space 143. The substrate 152 is preferably made of a material that is highly transparent to visible light.

[0281] The pixel electrode 191 can be manufactured using the same material and in the same process. The common layer 112, the common layer 114, and the common electrode 115 are used in common for the light emitting element 190B, the light emitting element 190G, and the light receiving / emitting element 190MER. The light receiving / emitting element 190MER has a configuration in which an active layer 183 is added to the configuration of a light emitting element that emits red light. The light emitting element 190B, the light emitting element 190G, and the light receiving / emitting element 190MER can all have a common configuration except for the configurations of the active layer 183 and the light emitting layers 193 of each color. This makes it possible to add a light receiving function to the display unit 162 of the display device 100A without significantly increasing the number of manufacturing processes.

[0282] A light-shielding layer BM is provided on the surface of the substrate 152 facing the substrate 151. The light-shielding layer BM has openings at positions overlapping with the light-emitting element 190B, the light-emitting element 190G, and the light-receiving / light-emitting element 190MER. By providing the light-shielding layer BM, the range in which the light-receiving / light-emitting element 190MER detects light can be controlled. Furthermore, by having the light-shielding layer BM, it is possible to prevent light from being directly incident on the light-receiving / light-emitting element 190MER from the light-emitting element 190G or the light-emitting element 190B without passing through an object. Therefore, a sensor with low noise and high sensitivity can be realized.

[0283] A color filter CF is provided on the surface of the substrate 152 facing the substrate 151. The color filter CF has an opening at a position overlapping with the light emitting / receiving element 190MER.

[0284] A transistor 201, a transistor 205, a transistor 206, and a transistor 207 are all formed over a substrate 151. These transistors can be manufactured using the same material and through the same process.

[0285] An insulating layer 211, an insulating layer 213, an insulating layer 215, and an insulating layer 214 are provided over the substrate 151 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 transistors. The insulating layer 214 is provided to cover the transistors and functions as a planarizing 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.

[0286] It is preferable that at least one of the insulating layers covering the transistors is made of a material that is difficult for impurities such as water or hydrogen to diffuse into. 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 transistors from the outside, thereby improving the reliability of the display device.

[0287] It is preferable to use an inorganic insulating film for each of the insulating layers 211, 213, and 215. As the inorganic insulating film, for example, an inorganic insulating film such as a silicon nitride film, a silicon oxynitride film, a silicon oxide film, a silicon nitride oxide film, an aluminum oxide film, or an aluminum nitride film can be used. A hafnium oxide film, a hafnium oxynitride film, a hafnium nitride 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, or a neodymium oxide film may be used. Two or more of the above insulating films may be stacked. Note that a base film may be provided between the substrate 151 and the transistor. The above inorganic insulating film may also be used for the base film.

[0288] Here, the organic insulating film often has a lower barrier property than the inorganic insulating film. Therefore, it is preferable that the organic insulating film has an opening near the end of the display device 100A. This makes it possible to suppress impurities from entering through the organic insulating film from the end of the display device 100A. Alternatively, the organic insulating film may be formed so that the end of the organic insulating film is located inside the end of the display device 100A, so that the organic insulating film is not exposed at the end of the display device 100A.

[0289] An organic insulating film is suitable for the insulating layer 214 that functions as a planarizing layer. Materials that can be used for the organic insulating film include acrylic resin, polyimide resin, epoxy resin, polyamide resin, polyimideamide resin, siloxane resin, benzocyclobutene resin, phenol resin, and precursors of these resins.

[0290] 19, an opening is formed in the insulating layer 214. This makes it possible to prevent impurities from entering the display unit 162 from the outside through the insulating layer 214, even when an organic insulating film is used for the insulating layer 214. This makes it possible to improve the reliability of the display device 100A.

[0291] The transistor 201, the transistor 205, the transistor 206, and the transistor 207 each have a conductive layer 221 functioning as a gate, an insulating layer 211 functioning as a gate insulating layer, a conductive layer 222a and a conductive layer 222b functioning as a source and a drain, a semiconductor layer 231, an insulating layer 213 functioning as a gate insulating layer, and a conductive layer 223 functioning as a gate. Here, the same hatched pattern is applied to a plurality of 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.

[0292] 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. In addition, either a top-gate type or a bottom-gate type transistor may be used. Alternatively, gates may be provided above and below a semiconductor layer in which a channel is formed.

[0293] The transistors 201, 205, 206, and 207 each 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 supplied with the same signal to drive the transistor. Alternatively, the threshold voltage of the transistor may be controlled by supplying a potential for controlling the threshold voltage to one of the two gates and a potential for driving to the other.

[0294] The crystallinity of a semiconductor material used in a transistor is not particularly limited, and any of an amorphous semiconductor, a single crystal semiconductor, and a semiconductor having crystallinity (a microcrystalline semiconductor, a polycrystalline semiconductor, or a semiconductor having a crystalline region in part) may be used. The use of a single crystal semiconductor or a semiconductor having crystallinity is preferable because it can suppress deterioration of transistor characteristics.

[0295] The semiconductor layer of the transistor preferably contains a metal oxide (also referred to as an oxide semiconductor). Alternatively, the semiconductor layer of the transistor may contain silicon. Examples of silicon include amorphous silicon and crystalline silicon (such as low-temperature polysilicon and single crystal silicon).

[0296] The semiconductor layer preferably contains, for example, indium, M (M is one or more selected from gallium, aluminum, silicon, boron, yttrium, tin, copper, vanadium, beryllium, titanium, iron, nickel, germanium, zirconium, molybdenum, lanthanum, cerium, neodymium, hafnium, tantalum, tungsten, and magnesium), and zinc. In particular, M is preferably one or more selected from aluminum, gallium, yttrium, and tin.

[0297] 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, gallium, zinc, and tin. Alternatively, it is preferable to use an oxide containing indium and zinc.

[0298] 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 In:M:Zn=1:1:1 or a composition thereabout, In:M:Zn=1:1:1.2 or a composition thereabout, In:M:Zn=2:1:3 or a composition thereabout, In:M:Zn=3:1:2 or a composition thereabout, In:M:Zn=4:2:3 or a composition thereabout, In:M:Zn=4:2:4.1 or a composition thereabout, In:M:Zn=5:1:3 or a composition thereabout, In:M:Zn=5:1:6 or a composition thereabout, In:M:Zn=5:1:7 or a composition thereabout, In:M:Zn=5:1:8 or a composition thereabout, In:M:Zn=10:1:3 or a composition thereabout, In:M:Zn=6:1:6 or a composition thereabout, In:M:Zn=5:2:5 or a composition thereabout, and the like. The term "nearby composition" includes a range of ±30% of the desired atomic ratio.

[0299] For example, when describing a composition with an atomic ratio of In:Ga:Zn=4:2:3 or thereabout, it includes cases where, when In is 4, Ga is 1 to 3 and Zn is 2 to 4. Furthermore, when describing a composition with an atomic ratio of In:Ga:Zn=5:1:6 or thereabout, it includes cases where, when In is 5, Ga is greater than 0.1 and less than 2 and Zn is greater than 5 and less than 7. Furthermore, when describing a composition with an atomic ratio of In:Ga:Zn=1:1:1 or thereabout, it includes cases where, when In is 1, Ga is greater than 0.1 and less than 2 and Zn is greater than 0.1 and less than 2.

[0300] The transistors included in the circuit 164 and the transistors included in the display portion 162 may have the same structure or different structures. The transistors included in the circuit 164 may all have the same structure or may have two or more types. Similarly, the transistors included in the display portion 162 may all have the same structure or may have two or more types.

[0301] A connection portion 204 is provided in an area of ​​the substrate 151 where the substrate 152 does not overlap. 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. On the upper surface of the connection portion 204, the conductive layer 166 obtained by processing the same conductive film as the pixel electrode 191 is exposed. This allows the connection portion 204 and the FPC 172 to be electrically connected via the connection layer 242.

[0302] Various optical members can be disposed on the outside of the substrate 152. Examples of optical members include a polarizing plate, a retardation plate, a light diffusion layer (such as a diffusion film), an anti-reflection layer, and a light collecting film. In addition, an antistatic film that suppresses the adhesion of dust, a water-repellent film that makes it difficult for dirt to adhere, a hard coat film that suppresses the occurrence of scratches due to use, an impact absorbing layer, and the like may be disposed on the outside of the substrate 152.

[0303] The substrate 151 and the substrate 152 can each be made of glass, quartz, ceramic, sapphire, resin, etc. When the substrate 151 and the substrate 152 are made of a flexible material, the flexibility of the display device can be increased.

[0304] As the adhesive layer, various curing adhesives such as a photo-curing adhesive such as an ultraviolet curing adhesive, a reaction curing adhesive, a heat curing adhesive, and an anaerobic adhesive can be used. 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-liquid mixed resin may also be used. An adhesive sheet or the like may also be used.

[0305] The connection layer may be made of an anisotropic conductive film (ACF), an anisotropic conductive paste (ACP), or the like.

[0306] 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, as well as alloys containing such metals as main components, etc. Films containing these materials can be used as a single layer or a laminated structure.

[0307] As the conductive material having light transmitting properties, conductive oxides such as indium oxide, indium tin oxide, indium zinc oxide, zinc oxide, zinc oxide containing gallium, or graphene can be used. Alternatively, metal materials such as gold, silver, platinum, magnesium, nickel, tungsten, chromium, molybdenum, iron, cobalt, copper, palladium, and titanium, alloy materials containing the metal materials, and the like can be used. Alternatively, nitrides of the metal materials (for example, titanium nitride) and the like may be used. Note that when using metal materials or alloy materials (or their nitrides), it is preferable to make them thin enough to have light transmitting properties. Also, a stacked film of the above materials can 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, because the conductivity can be increased. These can also be used for conductive layers such as various wirings and electrodes constituting a display device, or conductive layers (conductive layers functioning as pixel electrodes or common electrodes, etc.) of light emitting elements and light receiving and emitting elements.

[0308] 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.

[0309] [Display device 100B] FIG. 20 shows a cross-sectional view of the display device 100B.

[0310] The display device 100B differs from the display device 100A mainly in that it has a protective layer 195. Detailed description of the same configuration as the display device 100A will be omitted.

[0311] By providing a protective layer 195 covering the light-emitting element 190B, the light-emitting element 190G, and the light-receiving / light-emitting element 190MER, it is possible to prevent impurities such as water from entering the light-emitting element 190B, the light-emitting element 190G, and the light-receiving / light-emitting element 190MER, thereby improving the reliability of the light-emitting element 190B, the light-emitting element 190G, and the light-receiving / light-emitting element 190MER.

[0312] In a region 228 near the end of the display device 100B, it is preferable that the insulating layer 215 and the protective layer 195 contact each other through the opening in the insulating layer 214. In particular, it is preferable that the inorganic insulating film of the insulating layer 215 and the inorganic insulating film of the protective layer 195 contact each other. This makes it possible to suppress impurities from entering the display unit 162 from the outside through the organic insulating film. Therefore, it is possible to improve the reliability of the display device 100B.

[0313] The protective layer 195 may have a single layer or a laminated structure, and may have, for example, a three-layer structure having an inorganic insulating layer on the common electrode 115, an organic insulating layer on the inorganic insulating layer, and an inorganic insulating layer on the organic insulating layer. In this case, it is preferable that the end of the inorganic insulating layer extends outward beyond the end of the organic insulating layer.

[0314] Furthermore, a lens may be provided in a region overlapping with the light receiving / emitting element 190MER, thereby improving the sensitivity and accuracy of the sensor using the light receiving / emitting element 190MER.

[0315] The lens preferably has a refractive index of 1.3 or more and 2.5 or less. The lens can be formed using at least one of an inorganic material and an organic material. For example, a material containing a resin can be used for the lens. Also, a material containing at least one of an oxide and a sulfide can be used for the lens.

[0316] Specifically, the lens may be made of a resin containing chlorine, bromine, or iodine, a resin containing a heavy metal atom, a resin containing an aromatic ring, or a resin containing sulfur. Alternatively, the lens may be made of a material containing a resin and nanoparticles of a material with a higher refractive index than the resin. Titanium oxide or zirconium oxide may be used for the nanoparticles.

[0317] In addition, cerium oxide, hafnium oxide, lanthanum oxide, magnesium oxide, niobium oxide, tantalum oxide, titanium oxide, yttrium oxide, zinc oxide, oxides containing indium and tin, or oxides containing indium, gallium, and zinc can be used for the lens. Alternatively, zinc sulfide can be used for the lens.

[0318] In the display device 100B, the protective layer 195 and the substrate 152 are bonded together by an adhesive layer 142. The adhesive layer 142 is provided so as to overlap the light-emitting element 190B, the light-emitting element 190G, and the light-receiving / light-emitting element 190MER, respectively, and a solid sealing structure is applied to the display device 100B.

[0319] [Display device 100C] FIG. 21A shows a cross-sectional view of the display device 100C.

[0320] The display device 100C differs from the display device 100B in the structure of the transistors.

[0321] The display device 100C includes a transistor 208, a transistor 209, and a transistor 210 over a substrate 153.

[0322] The transistor 208, 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 having 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 between the conductive layer 223 and the channel formation region 231i.

[0323] 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.

[0324] The pixel electrode 191 of the light emitting element 190G is electrically connected to one of a pair of low resistance regions 231n of the transistor 208 via the conductive layer 222b.

[0325] The pixel electrode 191 of the light emitting / receiving element 190MER is electrically connected to the other of the pair of low resistance regions 231n of the transistor 209 via the conductive layer 222b.

[0326] 21A shows an example in which the insulating layer 225 covers the top and side surfaces of the semiconductor layer. On the other hand, in the transistor 202 shown in FIG. 21B, 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 insulating layer 225 is processed using the conductive layer 223 as a mask, so that the structure shown in FIG. 21B can be manufactured. In FIG. 21B, 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 connected to the low-resistance region 231n through the openings in the insulating layer 215. Furthermore, an insulating layer 218 may be provided to cover the transistor.

[0327] Furthermore, the display device 100C differs from the display device 100B in that it does not have the substrate 151 and the substrate 152, but has the substrate 153, the substrate 154, the adhesive layer 155, and the insulating layer 212.

[0328] The substrate 153 and the insulating layer 212 are bonded together by an adhesive layer 155. The substrate 154 and the protective layer 195 are bonded together by an adhesive layer 142.

[0329] The display device 100C is manufactured by transferring the insulating layer 212, the transistor 208, the transistor 209, the transistor 210, the light-emitting element 190MER, the light-emitting element 190G, and the like, which are formed on a manufacturing substrate, onto a substrate 153. Each of the substrate 153 and the substrate 154 is preferably flexible. This can increase the flexibility of the display device 100C.

[0330] The insulating layer 212 can be formed using the inorganic insulating film that can be used for the insulating layers 211, 213, and 215.

[0331] As described above, in the display device of this embodiment, a subpixel that exhibits one of the colors is provided with a light receiving / emitting element instead of a light emitting element. The light receiving / emitting element serves as both a light emitting element and a light receiving element, so that the pixel can be given a light receiving function without increasing the number of subpixels included in the pixel. In addition, the pixel can be given a light receiving function without reducing the resolution of the display device and the aperture ratio of each subpixel.

[0332] At least a part of the configuration examples illustrated in this embodiment and the drawings corresponding thereto can be appropriately combined with other configuration examples or drawings.

[0333] This embodiment mode can be implemented by appropriately combining at least a part of it with other embodiment modes described in this specification.

[0334] (Embodiment 3) In this embodiment, a metal oxide (also referred to as an oxide semiconductor) which can be used for the OS transistor described in the above embodiment will be described.

[0335] The metal oxide preferably contains at least indium or zinc. In particular, it is preferable that the metal oxide contains indium and zinc. In addition to these, it is preferable that the metal oxide contains aluminum, gallium, yttrium, tin, etc. Furthermore, the metal oxide may contain one or more elements selected from boron, silicon, titanium, iron, nickel, germanium, zirconium, molybdenum, lanthanum, cerium, neodymium, hafnium, tantalum, tungsten, magnesium, cobalt, etc.

[0336] Moreover, the metal oxide can be formed by a sputtering method, a chemical vapor deposition (CVD) method such as a metal organic chemical vapor deposition (MOCVD) method, or an atomic layer deposition (ALD) method.

[0337] <Classification of crystal structures> Examples of the crystal structure of an oxide semiconductor include amorphous (including completely amorphous), c-axis-aligned crystalline (CAAC), nanocrystalline (nc), cloud-aligned composite (CAC), single crystal, and polycrystal.

[0338] The crystal structure of the 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 a GIXD (Grazing-Incidence XRD) measurement. The GIXD method is also called the thin film method or the Seemann-Bohlin method.

[0339] For example, in the case of a quartz glass substrate, the peak shape of the XRD spectrum is almost symmetric. On the other hand, in the case of an IGZO film having a crystalline structure, the peak shape of the XRD spectrum is asymmetric. The asymmetric 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 symmetric, the film or substrate cannot be said to be in an amorphous state.

[0340] The crystal structure of a film or substrate can be evaluated by a diffraction pattern (also called 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, and it can be confirmed that the quartz glass is in an amorphous state. In addition, a spot-like pattern is observed in the diffraction pattern of an IGZO film formed at room temperature, rather than a halo. For this reason, it is presumed that an IGZO film formed at room temperature is in an intermediate state that is neither crystalline nor amorphous, and therefore it cannot be concluded that it is in an amorphous state.

[0341] <<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, amorphous-like oxide semiconductors (a-like OSs), amorphous oxide semiconductors, and the like.

[0342] Here, the above-mentioned CAAC-OS, nc-OS, and a-like OS will be described in detail.

[0343] [CAAC-OS] CAAC-OS is an oxide semiconductor having a plurality of crystalline regions, each of which has a c-axis aligned in a specific direction. The specific direction is the thickness direction of the CAAC-OS film, the normal direction of the surface on which the CAAC-OS film is formed, or the normal direction of the surface of the CAAC-OS film. The crystalline region is a region having periodic atomic arrangement. If the atomic arrangement is considered as a lattice arrangement, the crystalline region is also a region with a uniform lattice arrangement. CAAC-OS has a region in which a plurality of crystalline regions are connected in the ab-plane direction, and the region may have distortion. The distortion refers to a portion in which the direction of the lattice arrangement changes between a region with a uniform lattice arrangement and another region with a uniform lattice arrangement in the region in which the plurality of crystalline regions are connected. In other words, CAAC-OS is an oxide semiconductor having a c-axis aligned and no clear orientation in the ab-plane direction.

[0344] 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 about several tens of nm.

[0345] In addition, in an In-M-Zn oxide (wherein element M is one or more elements selected from aluminum, gallium, yttrium, tin, titanium, etc.), the 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, In layer) and a layer containing element M, zinc (Zn), and oxygen (hereinafter, (M, Zn) layer) are stacked. Note that indium and element M are mutually substituted. Thus, the (M, Zn) layer may contain indium. Also, the In layer may contain element M. Note that the In layer may contain Zn. The layered structure is observed as a lattice image in a high-resolution transmission electron microscope (TEM) image, for example.

[0346] When the CAAC-OS film is subjected to structural analysis using, for example, an XRD device, a peak indicating c-axis orientation is detected at or near 2θ=31° in out-of-plane XRD measurement using θ / 2θ scan. Note that the position of the peak indicating c-axis orientation (2θ value) may vary depending on the type and composition of the metal elements constituting the CAAC-OS.

[0347] For example, a plurality of bright points (spots) are observed in the electron diffraction pattern of the CAAC-OS film, and the two spots are observed at positions symmetrical to each other with respect to the spot of the incident electron beam that has passed through the sample (also called the direct spot).

[0348] When the crystal region is observed from the specific direction, the lattice arrangement in the crystal region is based on a hexagonal lattice, but the unit cell is not necessarily a regular hexagon and may be a non-regular hexagon. The above distortion may have a lattice arrangement such as a pentagon or heptagon. In addition, in the CAAC-OS, no clear grain boundary can be confirmed even in the vicinity of the distortion. That is, it can be seen that the formation of grain boundaries is suppressed by the distortion of the lattice arrangement. This is thought to be because the CAAC-OS can tolerate distortion due to the fact that the arrangement of oxygen atoms is not dense in the ab-plane direction or the bond distance between atoms changes due to the substitution of metal atoms.

[0349] A crystal structure in which clear grain boundaries are observed is called a polycrystal. The grain boundaries are likely to become recombination centers, trap carriers, and cause a decrease in the on-current of a transistor and 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. In order to form a CAAC-OS, a structure containing Zn is preferable. For example, In-Zn oxide and In-Ga-Zn oxide are suitable because they can suppress the occurrence of grain boundaries more than In oxide.

[0350] The 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. In addition, the crystallinity of an oxide semiconductor can be decreased by the inclusion of impurities or the generation of defects, and therefore the CAAC-OS can be said to be an oxide semiconductor with few impurities and defects (such as oxygen vacancies). Therefore, the physical properties of an oxide semiconductor having the CAAC-OS are stable. Therefore, an oxide semiconductor having the CAAC-OS is resistant to heat and has high reliability. In addition, the CAAC-OS is stable against high temperatures (so-called thermal budget) in the manufacturing process. Therefore, the use of the CAAC-OS in an OS transistor can increase the degree of freedom in the manufacturing process.

[0351] [nc-OS] The nc-OS has periodic atomic arrangement in a minute region (for example, a region of 1 nm to 10 nm, particularly a region of 1 nm to 3 nm). In other words, the nc-OS has minute crystals. Note that the size of the minute crystals is, for example, 1 nm to 10 nm, particularly 1 nm to 3 nm, and therefore the minute crystals are also called nanocrystals. In addition, the nc-OS does not show regularity in the crystal orientation between different nanocrystals. Therefore, no orientation is seen in the entire film. Therefore, the nc-OS may be indistinguishable from an a-like OS and an amorphous oxide semiconductor depending on the analysis method. For example, when a structure analysis is performed on an nc-OS film using an XRD device, no peak indicating crystallinity is detected in out-of-plane XRD measurement using θ / 2θ scan. In addition, when an nc-OS film is subjected to electron diffraction (also called selected area electron diffraction) using an electron beam with a probe diameter larger than that of nanocrystals (for example, 50 nm or more), a diffraction pattern like a halo pattern is observed. On the other hand, when electron diffraction (also called nanobeam electron diffraction) is performed on an nc-OS film using an electron beam with a probe diameter (e.g., 1 nm to 30 nm) that is close to the size of a nanocrystal or smaller than the nanocrystal, an electron diffraction pattern in which multiple spots are observed within a ring-shaped region centered on the direct spot may be obtained.

[0352] [a-like OS] The a-like OS is an oxide semiconductor having a structure between the nc-OS and the amorphous oxide semiconductor. The a-like OS has a void or low-density region. That is, the a-like OS has lower crystallinity than the nc-OS and CAAC-OS. Moreover, the a-like OS has a higher hydrogen concentration in the film than the nc-OS and CAAC-OS.

[0353] <<Oxide semiconductor structure>> Next, the above-mentioned CAC-OS will be described in detail, with reference to its material composition.

[0354] [CAC-OS] CAC-OS is, for example, a material configuration in which elements constituting a metal oxide are unevenly distributed in a size range of 0.5 nm to 10 nm, preferably 1 nm to 3 nm, or in the vicinity thereof. In the following, a state in which one or more metal elements are unevenly distributed in a metal oxide and the regions having the metal elements are mixed in a size range 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.

[0355] Furthermore, CAC-OS is a composite metal oxide in which the material is separated into a first region and a second region, forming a mosaic structure, and the first region is distributed throughout the film (hereinafter, also referred to as a cloud structure). In other words, CAC-OS is a composite metal oxide in which the first region and the second region are mixed together.

[0356] Here, the atomic ratios of In, Ga, and Zn to the metal elements constituting the CAC-OS in the In-Ga-Zn oxide are represented 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. Also, 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. Also, 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.

[0357] Specifically, the first region is a region mainly composed of indium oxide, indium zinc oxide, etc., and the second region is a region mainly composed of gallium oxide, gallium zinc oxide, etc. In other words, the first region can be rephrased as a region mainly composed of In, and the second region can be rephrased as a region mainly composed of Ga.

[0358] In addition, there are cases where a clear boundary between the first region and the second region cannot be observed.

[0359] In addition, the CAC-OS in In-Ga-Zn oxide refers to a structure in which some regions mainly composed of Ga and some regions mainly composed of In are arranged randomly in a mosaic pattern in a material structure containing In, Ga, Zn, and O. Therefore, it is presumed that the CAC-OS has a structure in which metal elements are distributed non-uniformly.

[0360] CAC-OS can be formed, for example, by a sputtering method under conditions where the substrate is not intentionally heated. When CAC-OS is formed by a sputtering method, any one or more selected from an inert gas (typically argon), oxygen gas, and nitrogen gas may be used as a deposition gas. The lower the flow rate ratio of oxygen gas to the total flow rate of deposition gas during deposition, the more preferable it is. For example, the flow rate ratio of oxygen gas to the total flow rate of deposition gas during deposition is preferably 0% or more and less than 30%, and more preferably 0% or more and 10% or less.

[0361] Furthermore, for example, in the case of a CAC-OS of an In-Ga-Zn oxide, EDX mapping obtained using EDX (Energy Dispersive X-ray Spectroscopy) can confirm that the CAC-OS has a structure in which a region mainly composed of In (first region) and a region mainly composed of Ga (second region) are unevenly distributed and mixed.

[0362] Here, the first region is a region with higher conductivity than the second region. In other words, the first region exhibits conductivity as a metal oxide when carriers flow through the first region. Therefore, the first region is distributed in a cloud-like shape in the metal oxide, thereby realizing a high field-effect mobility (μ).

[0363] 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, so that leakage current can be suppressed.

[0364] Therefore, when CAC-OS is used in a transistor, the conductivity due to the first region and the insulating property due to the second region act in a complementary manner, giving the CAC-OS a switching function (On / Off function). In other words, CAC-OS has a conductive function in part of the material and an insulating function in part of the material, and the material as a whole functions as a semiconductor. By separating the conductive function from the insulating function, it is possible to maximize both functions. Therefore, by using CAC-OS in a transistor, it is possible to achieve a high on-current (I on ), high field effect mobility (μ), and good switching operation can be achieved.

[0365] In addition, a transistor using CAC-OS has high reliability, making it ideal for various semiconductor devices such as display devices.

[0366] Oxide semiconductors have a variety of structures and have 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.

[0367] <Transistor Having Oxide Semiconductor> Next, the case where the oxide semiconductor is used for a transistor will be described.

[0368] By using the oxide semiconductor for a transistor, a transistor with high field-effect mobility and high reliability can be realized.

[0369] 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 Less than or equal to 1×10 15 cm -3 Less than 1×10, more preferably 13 cm -3Less than or equal to 1×10 11 cm -3 Less than 1×10, more preferably 10 cm -3 Less than 1 x 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, an oxide semiconductor having a low impurity concentration and a low density of defect states is referred to as a high-purity intrinsic or substantially high-purity intrinsic oxide semiconductor. Note that an oxide semiconductor having a low carrier concentration may be referred to as a high-purity intrinsic or substantially high-purity intrinsic oxide semiconductor.

[0370] In addition, 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 might also be low.

[0371] In addition, charges trapped in the trap states of an oxide semiconductor take a long time to disappear and may behave as if they are 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.

[0372] Therefore, in order to stabilize the electrical characteristics of a transistor, it is effective to reduce the impurity concentration in the oxide semiconductor. In order to reduce the impurity concentration in the oxide semiconductor, it is preferable to also reduce the impurity concentration in a nearby film. Examples of impurities include hydrogen, nitrogen, alkali metals, alkaline earth metals, iron, nickel, silicon, and the like.

[0373] <Impurities> Here, the influence of each impurity in an oxide semiconductor will be described.

[0374] When an oxide semiconductor contains silicon or carbon, which is one of the group 14 elements, defect levels are formed in the oxide semiconductor. For this reason, the concentration of silicon or carbon in the oxide semiconductor and the concentration of silicon or carbon near the interface with the oxide semiconductor (concentration obtained by secondary ion mass spectrometry (SIMS)) are set to 2×10 18 atoms / cm 3 Less than or equal to 2 x 10 17 atoms / cm 3 The following applies.

[0375] In addition, when an oxide semiconductor contains an alkali metal or an alkaline earth metal, defect levels are formed and carriers are generated in some cases. Therefore, a transistor using an oxide semiconductor containing an alkali metal or an alkaline earth metal is likely to have normally-on characteristics. For this reason, when the concentration of an alkali metal or an alkaline earth metal in an oxide semiconductor obtained by SIMS is 1×10 18 atoms / cm 3 Less than or equal to 2 x 10 16 atoms / cm 3 To the following:

[0376] Furthermore, when nitrogen is contained in an oxide semiconductor, electrons serving as carriers are generated, the carrier concentration increases, and the semiconductor is likely to become n-type. As a result, a transistor using an oxide semiconductor containing nitrogen as a semiconductor is likely to have normally-on characteristics. Alternatively, when nitrogen is contained in an oxide semiconductor, trap states may be formed. As a result, the electrical characteristics of the transistor may become unstable. For this reason, the nitrogen concentration in an oxide semiconductor obtained by SIMS is set to 5×10 19 atoms / cm 3 Less than 5 x 10 18 atoms / cm 3 Less than or equal to 1×10 18 atoms / cm 3 Less than 5×10, more preferably 17 atoms / cm 3 To the following:

[0377] Furthermore, hydrogen contained in an oxide semiconductor reacts with oxygen bonded to a metal atom to form water, which may form an oxygen vacancy. When hydrogen enters the oxygen vacancy, electrons serving as carriers may be generated. In addition, some of the hydrogen may bond with oxygen bonded to a metal atom to generate electrons serving as carriers. Therefore, a transistor using an oxide semiconductor containing hydrogen is likely to have normally-on characteristics. For this reason, it is preferable to reduce hydrogen in the oxide semiconductor as much as possible. Specifically, when the hydrogen concentration in an oxide semiconductor measured by SIMS is 1×10 20 atoms / cm 3 Less than 1 x 10 19 atoms / cm 3 less than 5×10 18 atoms / cm 3 less than 1×10 18 atoms / cm 3 Make it less than.

[0378] When an oxide semiconductor in which impurities are sufficiently reduced is used for a channel formation region of a transistor, stable electrical characteristics can be obtained.

[0379] This embodiment mode can be implemented by appropriately combining at least a part of it with other embodiment modes described in this specification.

[0380] (Embodiment 4) In this embodiment, an electronic device according to one embodiment of the present invention will be described.

[0381] The electronic device of this embodiment includes the display device of one embodiment of the present invention. For example, the display device of one embodiment of the present invention can be applied to a display portion of an electronic device. The display device of one embodiment of the present invention has a function of detecting light, and therefore can perform biometric authentication or detect a touch operation (contact or approach) in the display portion. This can improve the functionality, convenience, and the like of the electronic device.

[0382] Examples of electronic devices include electronic devices with relatively large screens, such as television sets, desktop or notebook personal computers, computer monitors, digital signage, large game machines such as pachinko machines, as well as digital cameras, digital video cameras, digital photo frames, mobile phones, portable game machines, personal digital assistants, and audio playback devices.

[0383] The electronic device of this embodiment may have a sensor (including a function to measure force, displacement, position, velocity, acceleration, angular velocity, rotation speed, distance, light, liquid, magnetism, temperature, chemical substances, sound, time, hardness, electric field, current, voltage, power, radiation, flow rate, humidity, gradient, vibration, odor, or infrared rays).

[0384] The electronic device of the present embodiment can have various functions, such as a function of displaying various information (still images, videos, text images, etc.) on a display unit, a touch panel function, a function of displaying a calendar, date, time, etc., a function of executing various software (programs), a wireless communication function, a function of reading out a program or data recorded on a recording medium, etc.

[0385] The electronic device 6500 shown in FIG. 22A is a portable information terminal that can be used as a smartphone.

[0386] The electronic device 6500 includes a housing 6501, a display portion 6502, a power button 6503, a button 6504, a speaker 6505, a microphone 6506, a camera 6507, and a light source 6508. The display portion 6502 has a touch panel function.

[0387] The display device of one embodiment of the present invention can be applied to the display portion 6502.

[0388] FIG. 22B is a schematic cross-sectional view including the end portion of the housing 6501 on the microphone 6506 side.

[0389] A light-transmitting protective member 6510 is provided on the display surface side of the housing 6501, and a display panel 6511, optical members 6512, a touch sensor panel 6513, a printed circuit board 6517, a battery 6518, etc. are arranged in the space surrounded by the housing 6501 and the protective member 6510.

[0390] A display panel 6511, an optical member 6512, and a touch sensor panel 6513 are fixed to the protective member 6510 by an adhesive layer (not shown).

[0391] In an area outside the display unit 6502, a part of the display panel 6511 is folded back, and the folded back part is connected to an FPC 6515. An IC 6516 is mounted on the FPC 6515. The FPC 6515 is connected to a terminal provided on a printed circuit board 6517.

[0392] The flexible display of one embodiment of the present invention can be applied to the display panel 6511. Therefore, an extremely lightweight electronic device can be realized. In addition, since the display panel 6511 is extremely thin, a large-capacity battery 6518 can be mounted thereon while suppressing the thickness of the electronic device. In addition, by folding back a part of the display panel 6511 and arranging a connection portion with the FPC 6515 on the back side of the pixel portion, an electronic device with a narrow frame can be realized.

[0393] When the display device of one embodiment of the present invention is used for the display panel 6511, an image can be captured in the display portion 6502. For example, a fingerprint can be captured on the display panel 6511 and fingerprint authentication can be performed.

[0394] The display portion 6502 can have a touch panel function by further including a touch sensor panel 6513. The touch sensor panel 6513 can be of any of various types, such as a capacitive type, a resistive film type, a surface acoustic wave type, an infrared type, an optical type, or a pressure-sensitive type. Alternatively, the display panel 6511 may function as a touch sensor, in which case the touch sensor panel 6513 is not necessarily provided.

[0395] 23A shows an example of a television device. A television device 7100 has a display unit 7000 built into a housing 7101. Here, the housing 7101 is supported by a stand 7103.

[0396] The display device of one embodiment of the present invention can be applied to the display portion 7000.

[0397] 23A can be operated using an operation switch provided on the housing 7101 or a separate remote control 7111. Alternatively, a touch sensor may be provided on the display unit 7000, and the television unit 7100 may be operated by touching the display unit 7000 with a finger or the like. The remote control 7111 may have a display unit that displays information output from the remote control 7111. Using operation keys or a touch panel provided on the remote control 7111, it is possible to operate the channel and volume, and to operate the video displayed on the display unit 7000.

[0398] The television device 7100 includes a receiver and a modem. The receiver can receive general television broadcasts. By connecting to a wired or wireless communication network via the modem, one-way (from sender to receiver) or two-way (between sender and receiver, or between receivers) information communication can be performed.

[0399] 23B shows an example of a laptop personal computer 7200. The laptop personal computer 7200 includes a housing 7211, a keyboard 7212, a pointing device 7213, an external connection port 7214, and the like. A display unit 7000 is incorporated in the housing 7211.

[0400] The display device of one embodiment of the present invention can be applied to the display portion 7000.

[0401] 23C and 23D show an example of digital signage.

[0402] 23C includes a housing 7301, a display unit 7000, and a speaker 7303. The digital signage 7300 may further include an LED lamp, an operation key (including a power switch or an operation switch), a connection terminal, various sensors, a microphone, and the like.

[0403] 23D shows a digital signage 7400 attached to a cylindrical pole 7401. The digital signage 7400 has a display unit 7000 provided along the curved surface of the pole 7401.

[0404] 23C and 23D, the display device of one embodiment of the present invention can be applied to the display portion 7000.

[0405] The larger the display unit 7000, the more information can be provided at one time. Also, the larger the display unit 7000, the more easily it catches people's attention, which can increase the advertising effect of, for example, advertisements.

[0406] Applying a touch panel to the display unit 7000 is preferable because it not only displays images or videos on the display unit 7000 but also allows the user to intuitively operate it. Furthermore, when used for providing information such as route information or traffic information, usability can be improved by intuitive operation.

[0407] 23C and 23D, it is preferable that the digital signage 7300 or the digital signage 7400 can be linked to an information terminal 7311 or an information terminal 7411 such as a smartphone carried by a user via wireless communication. For example, advertising information displayed on the display unit 7000 can be displayed on the screen of the information terminal 7311 or the information terminal 7411. Furthermore, the display on the display unit 7000 can be switched by operating the information terminal 7311 or the information terminal 7411.

[0408] In addition, a game can be executed on the digital signage 7300 or the digital signage 7400 using the screen of the information terminal 7311 or the information terminal 7411 as an operation means (controller). This allows an unspecified number of users to participate in and enjoy the game at the same time.

[0409] The electronic device shown in Figures 24A to 24F has a housing 9000, a display unit 9001, a speaker 9003, operation keys 9005 (including a power switch or an operation switch), a connection terminal 9006, a sensor 9007 (including a function to measure force, displacement, position, speed, acceleration, angular velocity, rotation speed, distance, light, liquid, magnetism, temperature, chemical substances, sound, time, hardness, electric field, current, voltage, power, radiation, flow rate, humidity, gradient, vibration, odor or infrared rays), a microphone 9008, etc.

[0410] The electronic device shown in Fig. 24A to Fig. 24F has various functions. For example, it can have a function of displaying various information (still images, videos, text images, etc.) on the display unit, a touch panel function, a function of displaying a calendar, date or time, a function of controlling processing by various software (programs), a wireless communication function, a function of reading and processing a program or data recorded on a recording medium, etc. The functions of the electronic device are not limited to these, and it can have various functions. The electronic device may have multiple display units. In addition, the electronic device may have a function of providing a camera or the like to take still images or videos and store them on a recording medium (external or built-in to the camera), a function of displaying the taken images on the display unit, etc.

[0411] The electronic devices shown in FIGS. 24A to 24F will be described in detail below.

[0412] FIG. 24A is a perspective view showing a mobile information terminal 9101. The mobile information terminal 9101 can be used as, for example, a smartphone. The mobile information terminal 9101 may be provided with a speaker 9003, a connection terminal 9006, a sensor 9007, and the like. The mobile information terminal 9101 can display text or image information on a plurality of surfaces. FIG. 24A shows an example in which three icons 9050 are displayed. Information 9051 shown in a dashed rectangle can also be displayed on another surface of the display unit 9001. Examples of the information 9051 include notifications of incoming e-mail, SNS, and phone calls, titles of e-mail or SNS, sender names, date and time, time, remaining battery power, and antenna reception strength. Alternatively, icons 9050 and the like may be displayed at the positions where the information 9051 is displayed.

[0413] 24B is a perspective view showing a mobile information terminal 9102. The mobile information terminal 9102 has a function of displaying information on three or more sides of the display unit 9001. Here, an example is shown in which information 9052, information 9053, and information 9054 are displayed on different sides. For example, a user can check information 9053 displayed in a position that can be observed from above the mobile information terminal 9102 while the mobile information terminal 9102 is stored in a breast pocket of clothes. The user can check the display without taking the mobile information terminal 9102 out of the pocket and decide, for example, whether or not to answer a call.

[0414] 24C is a perspective view showing a wristwatch-type mobile information terminal 9200. The display surface of the display unit 9001 is curved, and display can be performed along the curved display surface. The mobile information terminal 9200 can also perform hands-free conversation by communicating with a headset capable of wireless communication, for example. The mobile information terminal 9200 can also perform data transmission with another information terminal or charge the mobile information terminal 9200 through a connection terminal 9006. Charging may be performed by wireless power supply.

[0415] 24D to 24F are perspective views showing a foldable mobile information terminal 9201. FIG. 24D is a perspective view of the mobile information terminal 9201 in an unfolded state, FIG. 24F is a perspective view of the mobile information terminal 9201 in a folded state, and FIG. 24E is a perspective view of the mobile information terminal 9201 in a state in the middle of changing from one of FIG. 24D and FIG. 24F to the other. The mobile information terminal 9201 has excellent portability in a folded state, and has excellent viewability of the display due to a seamless wide display area in an unfolded state. The display unit 9001 of the mobile information terminal 9201 is supported by three housings 9000 connected by hinges 9055. For example, the display unit 9001 can be bent with a radius of curvature of 0.1 mm or more and 150 mm or less.

[0416] This embodiment mode can be implemented by appropriately combining at least a part of it with other embodiment modes described in this specification. [Explanation of symbols]

[0417] 10, 10a to 10i: display device 11, 12: substrate 15: element layer 16: functional layer 19: scatterer 20h: opening 20: light emitting / receiving element 21: conductive layer 22: organic layer 23: conductive layer 29: structure 30G, 30Ga, 30Gb, 30R: light 30Ref: scattered light 31: color filter 32: light shielding layer 41: insulating layer 42: adhesive layer 50B, 50G: light emitting element 51: conductive layer 52: organic layer 60a to 60c: pixel 61: gap

Claims

[Claim 1] The light emitting / receiving element and the color filter are included. The light emitting / receiving element has a light emitting / receiving region having a function of emitting light of a first color and a function of receiving light of a second color, the color filter is located on the light emitting / receiving element and has a function of transmitting the first color light and a function of blocking the second color light; the color filter has an opening, In a plan view, the light emitting and receiving region has a portion located inside the opening. Display device.

Images