Indication device

Abstract

To provide an imaging device or a display device that is capable of clearly capturing an image of a fingerprint or the like.SOLUTION: A display device includes a light-receiving element, a light-emitting element, a first substrate, a second substrate, a first resin layer, a second resin layer, and a light-blocking layer. The first resin layer, the second resin layer, and the second substrate are stacked over the first substrate. The light-receiving element and the light-emitting element are positioned between the first substrate and the first resin layer. The light-blocking layer is positioned between the first resin layer and the second resin layer and includes an opening portion overlapping with the light-receiving element. The opening portion in the light-blocking layer is positioned on an inner side of a light-receiving region of the light-receiving element in a plan view, and a width of the opening portion is less than or equal to a width of the light-receiving region. The second substrate is thicker than the first resin layer and the second resin layer. A thickness of a portion of the first resin layer, which overlaps with the light-receiving region of the light-receiving element, is greater than or equal to one time and less than or equal to 10 times as large as the width of the light-receiving region. The second substrate has a higher refractive index than the first resin layer and the second resin layer.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] FIELD OF THE INVENTION One aspect of the present invention relates to a display device.

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

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

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

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2014-197522 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 that is not easily damaged.

[0007] An object of one embodiment of the present invention is to reduce the number of components in 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, a vehicle, an electronic device, or the like having a novel structure.An object of one embodiment of the present invention is to alleviate 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 including a light-receiving element, a light-emitting element, a first substrate, a second substrate, a first resin layer, a second resin layer, and a light-shielding layer. The first resin layer, the second resin layer, and the second substrate are stacked in this order on the first substrate. The light-receiving element and the light-emitting element are respectively located between the first substrate and the first resin layer. The light-shielding layer is located between the first resin layer and the second resin layer and has a first opening that overlaps with the light-receiving element. The light-shielding layer has a region where the first opening is located inside the light-receiving region of the light-receiving element in a plan view and where the width of the first opening is equal to or less than the width of the light-receiving region in a cross-sectional view. The second substrate is thicker than the first and second resin layers. The first resin layer has a region where the thickness of a portion overlapping the light-receiving region of the light-receiving element is equal to or greater than 10 times the width of the light-receiving region. The second substrate has a higher refractive index for the wavelength of light emitted by the light emitting element than the first resin layer and the second resin layer.

[0010] Another embodiment of the present invention is a display device including a first display panel and a second display panel. The first display panel has a first region. The first region has a first pixel and a second pixel. The second display panel has a second region, a third region, and a fourth region. The second region has a third pixel. The third region has a function of transmitting visible light. The fourth region has a function of blocking visible light. The second pixel and the third region overlap each other. At least one of the first pixel, the second pixel, and the third pixel has a light-emitting element and a light-receiving element.

[0011] Furthermore, the first display panel or the second display panel preferably includes a light receiving element, a light emitting element, a first substrate, a second substrate, a first resin layer, a second resin layer, and a light-shielding layer. The first resin layer, the second resin layer, and the second substrate are stacked in this order on the first substrate. The light receiving element and the light emitting element are respectively located between the first substrate and the first resin layer. The light-shielding layer is located between the first resin layer and the second resin layer and has a first opening overlapping the light receiving element. In a plan view, the light-shielding layer has a region where the first opening is located inside the light-receiving region of the light receiving element and where, in a cross-sectional view, the width of the first opening is equal to or less than the width of the light-receiving region. The second substrate is thicker than the first resin layer and the second resin layer. The first resin layer has a region where the thickness of a portion overlapping the light-receiving region of the light receiving element is equal to or greater than 1 to 10 times the width of the light-receiving region. The second substrate has a higher refractive index for the wavelength of light emitted by the light emitting element than the first resin layer and the second resin layer.

[0012] In any of the above, the light-receiving element preferably has a first pixel electrode, an active layer, and a common electrode. The light-emitting element preferably has a second pixel electrode, a light-emitting layer, and a common electrode. In this case, the first pixel electrode and the second pixel electrode are preferably located on the same plane. Furthermore, the common electrode preferably has a portion overlapping the first pixel electrode via the active layer and a portion overlapping the second pixel electrode via the light-emitting layer.

[0013] In any of the above, it is preferable that the pixel electrode further includes a common layer having a portion located between the first pixel electrode and the common electrode, a portion located between the second pixel electrode and the common electrode, and a portion not overlapping with either the first pixel electrode or the second pixel electrode.

[0014] In any of the above, the first resin layer preferably has a lower refractive index for the wavelength of light emitted by the light emitting element than the second resin layer.

[0015] In any of the above, the second substrate preferably has a refractive index of 1.5 or more and 2.0 or less relative to the wavelength of light emitted by the light-emitting element, and the first resin layer preferably has a refractive index of 1.3 or more and 1.6 or less relative to the wavelength of light emitted by the light-emitting element.

[0016] In any of the above, it is preferable that a plurality of light receiving elements are provided. In this case, it is preferable that the plurality of light receiving elements are periodically arranged in a matrix. Furthermore, it is preferable that the arrangement pitch of the light receiving elements is 1 μm or more and 150 μm or less.

[0017] In the above, it is preferable that the light-emitting element further includes a plurality of light-emitting elements. In this case, it is preferable that the plurality of light-emitting elements are arranged in a matrix at the same arrangement pitch as the light-receiving elements. Alternatively, it is preferable that the plurality of light-emitting elements are arranged in a matrix at an arrangement pitch different from that of the light-receiving elements.

[0018] In any of the above, it is preferable that the device further includes a functional layer. In this case, it is preferable that the functional layer includes a third resin layer and is located between the second resin layer and the second substrate. It is also preferable that the third resin layer has a lower refractive index for the wavelength of light emitted by the light-emitting element than the second substrate. It is also preferable that the third resin layer is thinner than the second substrate and thicker than the first resin layer and the second resin layer.

[0019] In the above, the functional layer preferably functions as a polarizing plate or a touch sensor. In this case, the functional layer preferably has a first electrode provided along the first surface of the third resin layer.

[0020] In any of the above, it is preferable that the device further comprises a fourth resin layer. In this case, the fourth resin layer is preferably located between the functional layer and the second substrate. The fourth resin layer is preferably thinner than the second substrate and the functional layer. The fourth resin layer preferably has a lower refractive index for the wavelength of light emitted by the light-emitting element than the second substrate.

[0021] In any of the above, it is preferable that the device further includes a protective layer. In this case, the protective layer is located between the first substrate and the first resin layer. It is also preferable that the protective layer is provided to cover the light receiving element and the light emitting element and contains an inorganic insulator. It is also preferable that the protective layer is thinner than the first resin layer.

[0022] In the above, it is preferable to have a second electrode provided between the protective layer and the first resin layer. In this case, it is preferable that the second electrode functions as an electrode of a touch sensor. It is also preferable that the second electrode is thinner than the first resin layer.

[0023] Another aspect of the present invention is a display module including any one of the display devices described above and a connector or an integrated circuit.

[0024] 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.

[0025] Another aspect of the present invention is a vehicle in which any one of the display devices described above is provided along a surface of a dashboard.

[0026] Another aspect of the present invention is a vehicle in which any one of the display devices described above is provided along a surface of a door. [Effects of the Invention]

[0027] According to one embodiment of the present invention, a display device having an imaging function, an imaging device or a display device capable of clearly capturing an image of a fingerprint or the like, or a display device that is less susceptible to damage can be provided.

[0028] According to one aspect of the present invention, it is possible to reduce the number of components in an electronic device, provide a multifunctional display device, provide a display device, an imaging device, a vehicle, or an electronic device having a novel configuration, or alleviate at least one of the problems of the prior art.

[0029] 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 explanation of the drawings]

[0030] [Figure 1] FIG. 1 is a diagram showing an example of the configuration of a display device. [Figure 2] 2A to 2C are diagrams showing configuration examples of a display device. [Figure 3] Fig. 3A is a diagram showing an example of the configuration of a display device, Fig. 3B is a diagram showing an example of received light intensity, Fig. 3C is a diagram showing a contact area of ​​a finger, and Fig. 3D is a diagram showing an example of an image. [Figure 4] FIG. 4 is a diagram illustrating an example of the configuration of a display device. [Figure 5] FIG. 5 is a diagram illustrating an example of the configuration of a display device. [Figure 6] 6A to 6E are diagrams showing configuration examples of a touch sensor panel. [Figure 7] 7A, 7B, and 7D are cross-sectional views showing examples of the configuration of a display device. 7C and 7E are diagrams showing examples of images captured by the display device. 7F to 7H are top views showing examples of pixels. [Figure 8] 8A is a cross-sectional view showing an example of the configuration of a display device, and FIGS. 8B to 8D are top views showing an example of a pixel. [Figure 9] 9A is a cross-sectional view showing an example of the configuration of a display device, and FIGS. 9B to 9I are top views showing an example of a pixel. [Figure 10] 10A and 10B are diagrams showing configuration examples of a display device. [Figure 11] 11A to 11G are diagrams showing configuration examples of a display device. [Figure 12] 12A to 12C are diagrams showing configuration examples of a display device. [Figure 13] 13A to 13C are diagrams showing configuration examples of a display device. [Figure 14] 14A and 14B are diagrams showing configuration examples of a display device. [Figure 15] FIG. 15 is a diagram illustrating an example of the configuration of a display device. [Figure 16] Fig. 16A is a diagram showing a configuration example of a display device, Fig. 16B and Fig. 16C are diagrams showing configuration examples of a transistor. [Figure 17] 17A and 17B are diagrams showing examples of pixel configurations, and Fig. 17C to Fig. 17E are diagrams showing examples of pixel circuit configurations. [Figure 18] 18A and 18B are diagrams showing configuration examples of a display device. [Figure 19] 19A to 19C are diagrams showing configuration examples of a display device. [Figure 20] FIG. 20 is a diagram illustrating an example of the configuration of a vehicle. [Figure 21] 21A and 21B are diagrams showing configuration examples of electronic devices. [Figure 22] 22A to 22D are diagrams showing configuration examples of electronic devices. [Figure 23] 23A to 23F are diagrams showing configuration examples of electronic devices. [Figure 24] 24A and 24B are diagrams showing the measurement results of the absorption coefficient of the light receiving element. [Figure 25] 25A and 25B are diagrams showing the measurement results of the current-voltage characteristics of the light receiving element. [Figure 26] Fig. 26A is a diagram showing the measurement results of external quantum efficiency, and Fig. 26B is a diagram showing the reliability test results of the light receiving element. DETAILED DESCRIPTION OF THE INVENTION

[0031] Hereinafter, embodiments will be described with reference to the drawings. However, it will be readily understood by those skilled in the art that the embodiments can be implemented in many different ways and that various changes in form and details can be made without departing from the spirit and scope of the present invention. Therefore, the present invention should not be interpreted as being limited to the following description of the embodiments.

[0032] In the configuration of the invention described below, the same parts or parts having similar functions are denoted by the same reference numerals in different drawings, and repeated explanations thereof will be omitted. In addition, when referring to similar functions, the same hatch pattern may be used and no particular reference numeral may be assigned.

[0033] In the drawings described in this specification, the size of each component, the thickness of a layer, or an area may be exaggerated for clarity, and therefore, the drawings are not necessarily limited to the scale.

[0034] In this specification, ordinal numbers such as "first" and "second" are used to avoid confusion of components and do not limit the number.

[0035] In the following, expressions indicating directions such as "up" and "down" will basically be used in accordance with the directions in the drawings. However, for purposes such as facilitating explanation, the directions indicated by "up" or "down" in the specification may not match those in the drawings. For example, when explaining the stacking order (or formation order) of a laminate, etc., even if the surface on which the laminate is provided in the drawing (such as the surface to be formed, the supporting surface, the adhesive surface, or the flat surface) is located above the laminate, the direction toward that surface may be expressed as "down" and the opposite direction as "up."

[0036] In this specification, the EL layer refers to a layer provided between a pair of electrodes of a light-emitting element and containing at least a light-emitting substance (also referred to as a light-emitting layer), or a stack including a light-emitting layer.

[0037] 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 that has the function of generating electron-hole pairs by absorbing light. The active layer includes a single layer and a laminate.

[0038] In this specification and the like, a display panel, which is one aspect of a display device, has a function of displaying (outputting) images etc. on a display surface, and therefore the display panel is one aspect of an output device.

[0039] In addition, in this specification, a display panel having a connector such as an FPC (Flexible Printed Circuit) or TCP (Tape Carrier Package) attached to the substrate, or having an IC mounted on the substrate using a COG (Chip On Glass) method or the like, may be referred to as a display panel module, display module, or simply a display panel.

[0040] (Embodiment 1) In this embodiment, a configuration example of one embodiment of the present invention will be described.

[0041] One embodiment of the present invention includes a plurality of light-receiving elements (also referred to as light-receiving devices) and a plurality of light-emitting elements (also referred to as light-emitting devices) arranged in a matrix.

[0042] One embodiment of the present invention functions as an imaging device because it can capture an image using a plurality of light-receiving elements. In this case, the light-emitting elements can be used as a light source for capturing an image. Another embodiment of the present invention functions as a display device because it can display an image using a plurality of light-emitting elements. Therefore, one embodiment of the present invention can be said to be a display device having an imaging function or an imaging device having a display function.

[0043] For example, in a display device according to one embodiment of the present invention, light-emitting elements are periodically arranged in a matrix in the display portion, and light-receiving elements are also periodically arranged in a matrix in the display portion. Therefore, the display portion has a function of displaying an image and a function as a light-receiving portion. Since images can be captured by the light-receiving elements provided in the display portion, the display device can function as an image sensor, a touch panel, or the like. That is, the display portion can capture an image and detect the approach or contact of an object. Furthermore, since the light-emitting elements provided in the display portion can be used as a light source for receiving light, there is no need to provide a light source separately from the display device. Therefore, a highly functional display device can be realized without increasing the number of electronic components.

[0044] In one embodiment of the present invention, when light emitted from a light-emitting element included in a display portion is reflected by an object, the light-receiving element can detect the reflected light; therefore, imaging and touch (including non-touch) detection can be performed even in a dark environment.

[0045] Furthermore, the display device of one embodiment of the present invention can capture an image of a fingerprint or palm print when a finger, palm, or the like is placed in contact with the display unit. Therefore, an electronic device equipped with the display device of one embodiment of the present invention can perform personal authentication using the captured image of a fingerprint, palm print, or the like. This eliminates the need for a separate imaging device for fingerprint authentication, palm print authentication, or the like, thereby reducing the number of components in the electronic device. Furthermore, since the light-receiving elements are arranged in a matrix on the display unit, an image of a fingerprint, palm print, or the like can be captured anywhere on the display unit, thereby realizing an electronic device with excellent convenience.

[0046] 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 substance contained in the EL element include a substance that emits fluorescence (fluorescent material), a substance that emits phosphorescence (phosphorescent material), a substance that exhibits thermally activated delayed fluorescence (thermally activated delayed fluorescence: TADF material), and an inorganic compound (such as a quantum dot material).

[0047] As the light receiving element, for example, a pn-type or pin-type photodiode can be used. The light receiving element functions as a photoelectric conversion element that detects light incident on the light receiving element and generates an electric charge. The amount of electric charge generated by the photoelectric conversion element is determined according to the amount of incident light. In particular, it is preferable to use an organic photodiode having a layer containing an organic compound as the light receiving element. 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.

[0048] It is also preferable to use an organic compound for the active layer of the light-receiving element. In this case, it is preferable to provide one electrode (also called a pixel electrode) of the light-emitting element and the light-receiving element on the same surface. Furthermore, it is more preferable that the other electrode of the light-emitting element and the light-receiving element be an electrode (also called a common electrode) formed from one continuous conductive layer. Furthermore, it is more preferable that the light-emitting element and the light-receiving element have a common layer. This can simplify the manufacturing process when manufacturing the light-emitting element and the light-receiving element, reduce manufacturing costs, and improve manufacturing yield.

[0049] The light-emitting element and the light-receiving element can be configured to be provided between a first substrate and a second substrate. In this case, the light-emitting element emits light toward the second substrate, and the light-receiving element receives light incident from the second substrate. In addition, in the display device, the outer surface of the second substrate (the surface opposite to the first substrate) functions as the display surface and the light-receiving surface (also referred to as the imaging surface) of the display device. Note that the display surface and the light-receiving surface are not limited to the surface of the second substrate itself. For example, the surface of the second substrate may be coated with an inorganic or organic material.

[0050] The range of light received by one light-receiving element becomes wider as the object moves away from the light-receiving element, so if the distance between the light-receiving element and the object is large, the captured image becomes blurred and a clear image cannot be captured. Here, the distance between the light-receiving element and the object is smallest when the object is in contact with the light-receiving surface of the display device. Therefore, it is required that a clear image can be captured at least when the object is in contact with the light-receiving surface of the display device.

[0051] For example, by reducing the thickness of the second substrate, the distance between the light receiving element and the light receiving surface can be reduced, allowing for clearer images to be captured. However, reducing the thickness of the second substrate also reduces the mechanical strength of the display device. Therefore, there is a demand for a display device that can capture clear images and has high mechanical strength.

[0052] Therefore, one embodiment of the present invention has a structure in which a light-emitting element and a light-receiving element are arranged side by side on a first substrate, and further, a first resin layer, a second resin layer, and a second substrate are provided in this order to cover the light-emitting element and the light-receiving element. Furthermore, a light-shielding layer having an opening that overlaps with the light-receiving region of the light-receiving element is provided on the light-receiving element. The light-shielding layer is disposed between the first resin layer and the second resin layer. A material that is thicker than the first resin layer and the second resin layer is used for the second substrate. In addition, the first resin layer is made thicker than the width of the light-receiving region of the light-receiving element. Furthermore, a material that has a higher refractive index for the wavelength of light emitted by the light-emitting element than the first resin layer and the second resin layer is used for the second substrate.

[0053] The light-shielding layer, which has an opening that overlaps with the light-receiving element, can narrow the range in which the light-receiving element can receive light. Furthermore, by making the first resin layer thicker, the distance between the light-shielding layer and the light-receiving element can be increased, further narrowing the range in which the light-receiving element can receive light. Furthermore, by using a material with a high refractive index for the first substrate, the range of light incident on each light-receiving element can be further narrowed. This allows the second substrate to be thicker while still enabling clear imaging, thereby increasing mechanical strength.

[0054] Furthermore, by using a material for the first resin layer that has a lower refractive index for the wavelength of light emitted by the light-emitting element than that of the second resin layer, the difference in refractive index between the first and second resin layers can further narrow the range in which the light-receiving element can receive light. In this case, the effect can be further enhanced by making the second resin layer thinner than the first resin layer.

[0055] More specifically, it is preferable to select materials so that the refractive index (hereinafter simply referred to as the refractive index) for the wavelength of light emitted by the light-emitting element is the highest for the second substrate and the lowest for the first resin layer. In this case, it is preferable that the refractive index of the second substrate is 1.5 or more and 2.0 or less, and the refractive index of the first resin layer is 1.3 or more and 1.6 or less. If possible, the refractive index of the second substrate may be higher than 2.0. Also, if possible, the refractive index of the first resin layer may be lower than 1.3.

[0056] Furthermore, by arranging the light receiving elements at a high density, it becomes possible to capture a clearer image. Specifically, the arrangement pitch of the light receiving elements is set to 400 μm or less, preferably 200 μm or less, more preferably 150 μm or less, even more preferably 120 μm or less, even more preferably 100 μm or less, and even more preferably 50 μm or less. The smaller the arrangement pitch, the more preferable it is, but it can be set to, for example, 1 μm or more, 10 μm or more, or 20 μm or more.

[0057] A functional layer having a third resin layer can be provided between the second substrate and the second resin layer. The third resin layer is preferably made of a material that is thinner than the second substrate and thicker than the first and second resin layers. Furthermore, the third resin layer is preferably made of a material that has a lower refractive index than the second substrate.

[0058] As the functional layer, for example, an optical member such as a polarizing plate (including a circular polarizing plate), a light-condensing film, or a microlens array can be used.

[0059] Alternatively, a touch sensor panel may be used as the functional layer. The touch sensor provided in the touch sensor panel may be of various types, such as a resistive film type, a capacitance type, an infrared type, an electromagnetic induction type, or a surface acoustic wave type. It is particularly preferable to use a capacitance type touch sensor as the touch sensor. When using a touch sensor, the functional layer may include a third resin layer and one or more conductive layers that are provided on one surface of the third resin layer and function as electrodes.

[0060] A fourth resin layer may be further provided between the functional layer and the second substrate. In this case, the fourth resin layer is preferably made of a material thinner than the second substrate and the functional layer. The fourth resin layer is preferably made of a material having a lower refractive index than the second substrate.

[0061] A more specific example will be described below with reference to the drawings.

[0062] [Configuration example 1] FIG. 1 shows a schematic cross-sectional view of a display device 10 according to one embodiment of the present invention.

[0063] The display device 10 includes a substrate 11, a substrate 12, a light receiving element 20, a light emitting element 30, a resin layer 13, a resin layer 14, a light blocking layer 25, an insulating layer 41, and the like.

[0064] The light receiving element 20 and the light emitting element 30 are provided on a substrate 11. The resin layer 13 is provided to cover the light receiving element 20 and the light emitting element 30. The resin layer 14 is provided between the resin layer 13 and the substrate 12. The light blocking layer 25 is provided between the resin layer 13 and the resin layer 14.

[0065] The light emitting element 30 has a function of emitting light 51 toward the substrate 12. The light receiving element 20 has a function of receiving light 52 incident from the substrate 12 side.

[0066] The light-emitting element 30 may be a light-emitting element that emits light of any one of red (R), green (G), or blue (B), or may be a light-emitting element that emits light of white (W), yellow (Y), or the like. The light-emitting element 30 may have two or more peaks in its emission spectrum.

[0067] The light receiving element 20 has a conductive layer 21 that functions as a pixel electrode, a photoelectric conversion layer 22, and a conductive layer 23 that functions as a common electrode. The photoelectric conversion layer 22 has at least an active layer. The conductive layer 21 is provided on a substrate 11. An insulating layer 41 is provided to cover the end portion of the conductive layer 21. The photoelectric conversion layer 22 is provided on the conductive layer 21 and the insulating layer 41. The conductive layer 23 is provided on the photoelectric conversion layer 22 and the insulating layer 41.

[0068] The light-emitting element 30 has a conductive layer 31 that functions as a pixel electrode, an EL layer 32, and a conductive layer 23 that functions as a common electrode. The EL layer 32 has at least a light-emitting layer. The conductive layer 31 is provided on a substrate 11. An insulating layer 41 is provided to cover the end portions of the conductive layer 31. The EL layer 32 is provided on the conductive layer 31 and the insulating layer 41. The conductive layer 23 is provided on the EL layer 32 and the insulating layer 41.

[0069] Here, the conductive layer 21 and the conductive layer 31 are preferably provided on the same surface of the substrate 11. Furthermore, the conductive layer 21 and the conductive layer 31 are preferably formed by processing the same conductive film. Furthermore, the conductive layer 23 has a portion that overlaps with the conductive layer 21 via the photoelectric conversion layer 22, and a portion that overlaps with the conductive layer 31 via the EL layer 32. With this configuration, the light receiving element 20 and the light emitting element 30 can be fabricated using a common process except for the photoelectric conversion layer 22 and the EL layer 32, thereby reducing fabrication costs.

[0070] FIG. 1 shows an example in which the conductive layer 21 and the conductive layer 31 are provided directly on the substrate 11, but it is preferable that an insulating layer, wiring, electrodes, transistors, capacitors, etc. are appropriately provided between the conductive layer 21 and the conductive layer 31 and the substrate 11.

[0071] The resin layer 13 is provided to cover the conductive layer 23. The resin layer 13 functions as a protective layer for protecting the light receiving element 20 and the light emitting element 30. Note that a protective layer containing an inorganic insulating material may be further provided between the resin layer 13 and the conductive layer 23.

[0072] The light-shielding layer 25 is provided on the resin layer 13. The light-shielding layer 25 has the function of blocking part of the light incident from the substrate 12 side and controlling the range of light received by the light-receiving element 20.

[0073] The resin layer 14 functions as an adhesive layer for bonding the resin layer 13 and the substrate 12 together.

[0074] Here, the light-shielding layer 25 has an opening that overlaps the light-receiving region of the light-receiving element 20. The opening is preferably provided so as to be located inside the light-receiving region of the light-receiving element 20 in plan view.

[0075] FIG. 1 shows the width W of the light receiving area of ​​the light receiving element 20. PD and the width W of the opening of the light-shielding layer 25 PHThe light receiving region of the light receiving element 20 can be an area on the conductive layer 21 that is not covered by the insulating layer 41. That is, the width W of the light receiving region of the light receiving element 20 in a cross-sectional view PD can be rephrased as the length of a straight line connecting the ends of a pair of insulating layers 41 on the conductive layer 21. Alternatively, the width W of the light receiving region PD can also be expressed as the width of the region where the conductive layer 21 and the photoelectric conversion layer 22 contact each other.

[0076] 1, it is preferable that the opening of the light-shielding layer 25 is positioned inside the light-receiving region of the light-receiving element 20. PD For width W PH The smaller the width W, the narrower the range in which the light receiving element 20 can receive light, making it possible to capture a clearer image. PH If the width W is too small, the amount of light reaching the light receiving element 20 decreases, and therefore the exposure time needs to be increased. PH can be set to an appropriate width depending on the sensitivity of the light receiving element 20.

[0077] Here, the thickness of the resin layer 13 is T R1 , the thickness of the resin layer 14 is T R2 , the thickness of the substrate 12 is thickness T S If these thicknesses are not uniform, the thickness at least of the portion overlapping the light receiving region of the light receiving element 20 is used as the thickness. R1 is the distance from the upper surface of the conductive layer 23 on the conductive layer 21 to the upper surface of the resin layer 13.

[0078] Thickness T of the substrate 12 S is the thickness T of the resin layer 13 R1 and the thickness T of the resin layer 14 R2 The thickness T of the substrate 12 is preferably greater than S The thicker the thickness T, the higher the mechanical strength can be. Sis 0.1 mm or more, preferably 0.2 mm or more, more preferably 0.5 mm or more, and even more preferably 0.7 mm or more, and can be 5 mm or less, preferably 3 mm or less, and more preferably 2 mm or less. Typically, it can be 0.5 mm, 0.7 mm, 1.0 mm, 1.3 mm, or 1.5 mm.

[0079] Thickness T of the resin layer 13 R1 is the thickness T of the resin layer 14 R2 The thicker the resin layer 13, the greater the distance between the light receiving element 20 and the light blocking layer 25. This narrows the imaging range of each light receiving element 20, making it possible to capture a clear image.

[0080] Here, the thickness T of the resin layer 13 R1 is the width W of the light receiving area of ​​the light receiving element 20 PD For example, the width W PD Thickness T R1 The ratio (T R1 / W PD ) can be 1 or more, preferably 1.2 or more, more preferably 1.5 or more, and even more preferably 2.0 or more, and can be 10 or less, preferably 8 or less, more preferably 6 or less, and even more preferably 5 or less.

[0081] Thickness T of the resin layer 13 R1 For example, the thickness may be 1 μm or more, preferably 3 μm or more, more preferably 5 μm or more, and even more preferably 10 μm or more, and may be 200 μm or less, preferably 100 μm or less, more preferably 70 μm or less, and even more preferably 50 μm or less. Typically, the thickness may be about 20 μm, about 30 μm, or about 40 μm.

[0082] For example, the width W of the opening of the light-shielding layer 25 PH and the width W of the light receiving area of ​​the light receiving element 20 PD are equal, and the thickness T of the resin layer 13 R1 and the width W of the light receiving area of ​​the light receiving element 20 PDWhen the widths W of the openings in the light-shielding layer 25 are equal to each other, the maximum incident angle of light reaching the light-receiving region of the light-receiving element 20 through the openings in the light-shielding layer 25 is 45 degrees. If the maximum incident angle is sufficiently larger than 45 degrees (for example, 50 degrees or more, or 60 degrees or more), light that is totally reflected inside the substrate 12, resin layer 14, etc. may be incident, which may reduce the contrast of the captured image. Therefore, the width W of the openings in the light-shielding layer 25 is set to 45 degrees or less so that the maximum incident angle is 45 degrees or less. PH , or the thickness T of the resin layer 13 R1 It is preferable to adjust the following.

[0083] Thickness T of the resin layer 13 R1 is the width W of the light receiving area of ​​the light receiving element 20 PD The larger the thickness T of the resin layer 13 is, the closer the maximum incident angle is to 0 degrees, and the narrower the imaging range of one light receiving element 20 can be. R1 However, in consideration of productivity, as described above, the width W of the light receiving region of the light receiving element 20 is PD The thickness can be 10 times or less, preferably 8 times or less, more preferably 6 times or less, and even more preferably 5 times or less.

[0084] Here, the refractive index of the resin layer 13 with respect to the wavelength of the light 51 emitted by the light emitting element 30 is n R1 , the refractive index of the resin layer 14 for that wavelength is n R2 , the refractive index of the substrate 12 for that wavelength is n S The wavelength of the light 51 is the wavelength of the highest peak in the spectrum of the light 51, or the refractive index for light with a wavelength of 550 nm.

[0085] The refractive index n of the substrate 12 S is the refractive index n of the resin layer 13 R1 , and the refractive index n of the resin layer 14 R2 This makes it possible to narrow the imaging range of one light receiving element 20, and a clear image can be obtained even if the thickness of the substrate 12 is thick. SThe refractive index n of the substrate 12 is, for example, 1.5 or more, preferably 1.55 or more, more preferably 1.6 or more, and can be 2.0 or less, 1.98 or less, or 1.96 or less. S may be higher than 2.0 if possible.

[0086] The substrate 12 may be a glass substrate such as barium borosilicate glass or aluminoborosilicate glass, a quartz substrate, or a sapphire substrate. High-refractive index glass containing titanium, yttrium, niobium, lanthanum, lead, bismuth, gadolinium, or the like may also be used. Alternatively, a high-refractive index resin material may also be used.

[0087] The refractive index n of the resin layer 13 R1 is the refractive index n of the substrate 12 S The greater the difference between the refractive index n and the refractive index n of the resin layer 13, the more preferably the imaging range of one light receiving element 20 is narrowed by utilizing refraction. R1 The refractive index n of the resin layer 13 can be set to 1.3 or more, 1.35 or more, or 1.4 or more, and 1.6 or less, preferably 1.58 or less, and more preferably 1.56 or less. R1 may be lower than 1.3 if possible.

[0088] The refractive index n of the resin layer 14 R2 is the refractive index n R1 or more, and the refractive index n S The refractive index of the resin layer 14 may be set within the following range. For example, the resin layer 14 may be made of the same material as the resin layer 13, so that the resin layer has a similar refractive index. Note that even if the material is the same, different refractive indices may be exhibited depending on the formation method. In such a case, the refractive index n R2 is the refractive index n of the resin layer 13 R1 It is preferable to adjust the thickness so that it does not fall below . S In some cases, such as when the refractive index is less than one-tenth of that of the resin layer 13, the resin layer 14 may be made of a material having a lower refractive index than the resin layer 13.

[0089] Resin layer 13 and resin layer 14 may be made of acrylic resin, epoxy resin, polyimide resin, polyamide resin (nylon, aramid, etc.), polyamideimide resin, benzocyclobutene resin, phenolic resin, polyester resin such as polyethylene terephthalate (PET) or polyethylene naphthalate (PEN), polyacrylonitrile resin, polymethyl methacrylate resin, polycarbonate (PC) resin, polyethersulfone (PES) resin, polysiloxane resin, cycloolefin resin, polystyrene resin, polyurethane resin, polyvinyl chloride resin, polyvinylidene chloride resin, polypropylene resin, polytetrafluoroethylene (PTFE) resin, ABS resin, cellulose nanofiber, etc. Alternatively, precursors of the above resins may be used.

[0090] With this configuration, it is possible to provide a display device or an imaging device that has high mechanical strength and is capable of capturing clear images.

[0091] [Pixel configuration example] As described above, one embodiment of the present invention can capture an image using a plurality of light-receiving elements arranged in a matrix. Furthermore, an image can be displayed using a plurality of light-emitting elements arranged in a matrix. A full-color display device can be realized by arranging light-emitting elements of three colors, for example, red (R), green (G), and blue (B), in one pixel of the display device. An example of a pixel included in the display device will be described below.

[0092] [Pixel configuration example] 2A shows an example of the configuration of a pixel 40. The pixel 40 has a light receiving element 20, a light emitting element 30R, a light emitting element 30G, and a light emitting element 30B. The light emitting element 30R is a light emitting element that emits red light, the light emitting element 30G is a light emitting element that emits green light, and the light emitting element 30B is a light emitting element that emits blue light.

[0093] Although the example shown here shows the light receiving elements 20 and the light emitting elements arranged at the same arrangement pitch, they may be arranged at different arrangement pitches. For example, the light receiving elements 20 may be arranged at a smaller arrangement pitch than the light emitting elements, or at a larger arrangement pitch than the light emitting elements. In this case, it is preferable that the arrangement pitch of the light receiving elements 20 is an integer multiple of the arrangement pitch of the light emitting elements, or that the arrangement pitch of the light emitting elements is an integer multiple of the arrangement pitch of the light receiving elements 20.

[0094] Also, although an example has been shown here in which one light-emitting element of each type and one light-receiving element 20 are provided in one pixel, multiple light-emitting elements of the same color or multiple light-receiving elements 20 may be provided in one pixel.

[0095] Although an example in which light-emitting elements emitting light of different colors are provided in one pixel has been shown here, in the case of performing a monochromatic display or using the light-emitting element only as a light source for imaging, one pixel may have one or more light-emitting elements emitting light of the same color and one or more light-receiving elements. Furthermore, the monochromatic light-emitting elements and the light-receiving elements 20 may be independently arranged in a matrix at different arrangement pitches.

[0096] FIG. 2A shows three pixels 40 in the row direction (horizontal direction) and two pixels 40 in the column direction (vertical direction). The light receiving elements 20 and the light emitting elements 30G are arranged alternately in the row direction. The light emitting elements 30B and the light emitting elements 30R are arranged alternately in the row direction. The light receiving elements 20 and the light emitting elements 30B are arranged alternately in the column direction. Note that the configuration is not limited to that shown in FIG. 2A, and the positions of the light receiving elements 20, the light emitting elements 30R, the light emitting elements 30G, and the light emitting elements 30B can be interchanged.

[0097] Here, the pixels 40 are arranged at an array pitch P P Therefore, the light receiving elements 20, the light emitting elements 30R, the light emitting elements 30G, and the light emitting elements 30B are arranged at an arrangement pitch P P They are arranged as follows.

[0098] 2B, the pixel 40a has the light-emitting elements 30R, 30G, and 30B arranged side by side in the row direction, and the light-receiving elements 20 arranged in a different row. In the pixel 40a, the light-emitting elements 30R, 30G, and 30B are also arranged at an arrangement pitch P P They are arranged as follows.

[0099] [About the imaging range of the light receiving element] Fig. 2C shows a schematic cross-sectional view of a region including a plurality of pixels 40. As an example, Fig. 2C shows a schematic cross-sectional view of a region including the light receiving element 20 and the light emitting element 30G in Fig. 2A cut in the row direction.

[0100] 2C, for simplicity, the light receiving elements 20 and the light emitting elements 30G are each shown as a rectangle. As shown in FIG. 2C, the light receiving elements 20 and the light emitting elements 30G are each arranged at an arrangement pitch P P In Fig. 2C, the light receiving elements 20 and the light emitting elements 30G are arranged at equal intervals.

[0101] Here, the imaging range of one light receiving element 20 will be described when focusing on the light receiving element 20.

[0102] Light incident from above the substrate 12 is refracted at the interface between the substrate 12 and the resin layer 14. At this time, since the refractive index of the resin layer 14 is lower than that of the substrate 12, the refraction angle is larger than the angle of incidence when the light enters the resin layer 14 from the substrate 12. Furthermore, the light that has passed through the resin layer 14 is also refracted at the interface between the resin layer 14 and the resin layer 13. If the refractive index of the resin layer 13 is lower than that of the resin layer 14, the refraction angle of the light that enters the resin layer 13 from the resin layer 14 is larger than the angle of incidence.

[0103] The maximum incident angle of light incident on the light receiving element 20 is roughly determined by the width of the light receiving region of the light receiving element 20, the width of the opening in the light blocking layer 25, and the thickness of the resin layer 13 (the distance between the light receiving element 20 and the light blocking layer 25). Specifically, the angle formed by a line (shown by a dashed dotted line) connecting the end of the light receiving region of the light receiving element 20 and the end of the light blocking layer 25 located opposite thereto, and a line (shown by a dashed two dotted line) perpendicular to the light receiving surface of the light receiving element 20 is the maximum incident angle of light that can be incident on the light receiving element 20.

[0104] The area surrounded by the two dashed lines shown in Figure 2C corresponds to the imaging range of the light receiving element 20 when the resin layer 13, the resin layer 14, and the substrate 12 each have the same refractive index and no refraction occurs at their interfaces.

[0105] Region W shown in Figure 2C S corresponds to the imaging range of one light receiving element 20 on the upper surface of the substrate 12. In this way, by using a material with a higher refractive index than the resin layers 13 and 14 for the substrate 12, which is located on the imaging surface side and is the thickest among the substrate 12, resin layer 13, and resin layer 14, and by using a material with a lower refractive index than the substrate 12 and resin layer 14 for the resin layer 13 closest to the light receiving element 20, it is possible to suitably narrow the imaging range of one light receiving element 20. This makes it possible to capture a clear image.

[0106] [About imaging] The following describes imaging an object in contact with the outer surface of the substrate 12.

[0107] 3A shows a schematic cross-sectional view of the display device 10 and a finger 50 as an object that comes into contact with the substrate 12 of the display device 10. For simplicity, FIG. 3A shows only the light receiving elements 20, omitting the light blocking layer 25, light emitting elements, etc. The light receiving elements 20 are arranged at an array pitch P P They are arranged as follows.

[0108] A fingerprint is formed on the surface of finger 50 by recessed and protruding portions. As shown in Fig. 3A, when finger 50 touches substrate 12, the protruding portions of finger 50 come into contact with substrate 12, and the recessed portions do not. By separating the contacted portions from the non-contacted portions from the image captured by display device 10, the fingerprint pattern can be obtained.

[0109] The distance between the convex portions of the fingers 50 is defined as a pitch P F The arrangement pitch P of the light receiving elements 20 is P is the distance between two raised areas of the fingerprint (pitch P F ), preferably the distance between adjacent recesses and protrusions (pitch P F By making the pitch smaller than half of the human finger pitch P, a clear fingerprint image can be obtained. F Although there are individual differences, it is generally between 300 μm and 500 μm, typically about 460 μm. Therefore, the arrangement pitch of the light receiving elements 20 is set to 400 μm or less, preferably 200 μm or less, more preferably 150 μm or less, even more preferably 120 μm or less, even more preferably 100 μm or less, and even more preferably 50 μm or less. The smaller the arrangement pitch, the better, but it can be set to, for example, 1 μm or more, or 10 μm or more.

[0110] In FIG. 3A, the area W S is indicated by a dashed line. Also, the imaging ranges of three adjacent light receiving elements 20, including the light receiving element 20, are indicated by dotted lines. As shown in Fig. 3A, the imaging ranges of the multiple light receiving elements 20 may overlap with one another.

[0111] Here, light reflected from a surface or interface can be classified as specular or diffuse. Specular reflected light is highly directional light, with the angle of incidence and the angle of reflection matching, while diffuse reflected light is low-directional light, with its intensity less dependent on the angle. Unless the surface is an ideal mirror or an ideal scatterer, the light reflected by a surface or interface will include both specular and diffuse reflected light. Here, the diffuse reflection component of the specular and diffuse reflections is dominant in the light reflected from the surface of the finger 50. On the other hand, the specular reflection component is dominant in the light reflected from the interface between the substrate 12 and the atmosphere.

[0112] When capturing an image of a fingerprint, a light-emitting element (not shown) provided on the substrate 11 is caused to emit light, and the light reflected by the surface of the substrate 12 (or the interface with the finger 50) is received by the light-receiving element 20, thereby capturing the image. Here, at the concave portions of the finger 50, the substrate 12 and the finger 50 do not come into contact with each other, so reflection occurs at the interface between the substrate 12 and the air, and specular reflection light predominates. On the other hand, at the convex portions of the finger 50, the substrate 12 and the finger 50 come into contact with each other, so diffuse reflection light predominates. Therefore, the intensity of light received by the light-receiving element 20 located directly below the concave portions (received light intensity) is higher than that of the light-receiving element 20 located directly below the convex portions. This makes it possible to capture an image with contrast between the concave portions and the convex portions.

[0113] As shown in FIG. 3A, an area W S The width of the fingerprint is two periods of the fingerprint of the finger 50 (pitch P F The area W should be smaller than 2 times the area W. S The width of the pitch P F If it exceeds twice the area W S Since two or more convex or concave portions of the finger 50 are included within the image, it becomes difficult to obtain a clear image.

[0114] 3B shows an example of the intensity of light received by each of the 18 light receiving elements 20 in FIG. 3A (received light intensity). The horizontal axis of FIG. 3B indicates the address of the light receiving element 20. As shown in FIGS. 3A and 3B, the light receiving intensity of the light receiving elements 20 closer to the concave portions of the finger 50 is high, and the light receiving intensity of the light receiving elements 20 closer to the convex portions is low.

[0115] The data of the received light intensity acquired by the light receiving element 20 is output as analog data, converted to digital, and can be handled as a digital value. For example, if the image data has 8-bit gradation, a smooth fingerprint image can be obtained. Furthermore, not only fingerprints but also the surfaces of various objects (printed materials, photographs, and any other objects) can be clearly imaged. On the other hand, in biometric authentication such as fingerprint authentication and palm print authentication, using image data with a low number of gradations makes it possible to clarify the patterns of fingerprints, palm prints, etc., and to perform authentication with high accuracy.

[0116] When the data of the intensity of light received by the light receiving element 20 is binarized, a predetermined threshold intensity I th Set the threshold intensity I th It is possible to generate binary data with a threshold intensity I th can be appropriately set based on all data received by all light receiving elements 20. For example, it may be the median value between the maximum and minimum values ​​of all data, or it may be the average value. Note that, taking into consideration the influence of noise, dark current, etc., the threshold intensity I th It is preferable to set the value higher than the median or average value. Alternatively, binary data may be generated using data from which the effects of noise, dark current, etc. have been removed in advance.

[0117] Next, an example of an image when a fingerprint is captured will be described. FIG. 3C is a diagram showing a schematic diagram of contact and non-contact areas between the finger 50 and the substrate 12. The contact areas are hatched. FIG. 3D is an example of an image captured using the light receiving element 20. FIG. 3D shows a binarized image of 32 vertical x 48 horizontal pixels. In this way, a pattern reflecting the unevenness of the fingerprint can be clearly captured. Furthermore, the arrangement pitch P of the light receiving elements 20 P By reducing , an even smoother image than that shown in Figure 3D can be obtained.

[0118] [Configuration example 2] Below, an example of a display device having a different configuration from the above will be described. Note that, in the following, it is assumed that the same parts as those described above can be used, and the description may be omitted.

[0119] [Configuration Example 2-1] A cross-sectional schematic diagram of the display device 10a is shown in Fig. 4. The display device 10a differs from the display device 10 illustrated in Fig. 1 mainly in that the display device 10a includes a functional layer 15, a protective layer 42, a conductive layer 43, a resin layer 16, etc.

[0120] The functional layer 15 is provided between the resin layer 14 and the substrate 12. The resin layer 16 is provided between the functional layer 15 and the substrate 12 and functions to bond them together. The resin layer 14 also functions to bond the resin layer 13 and the functional layer 15 together.

[0121] The functional layer 15 can be, for example, an optical member such as a polarizing plate (including a circular polarizing plate), a light-collecting film, or a microlens array. By providing a circular polarizing plate as the functional layer 15, it is possible to suppress reflection of external light in the display and improve display quality. Furthermore, by using a microlens array having microlenses overlapping the light receiving elements 20 as the functional layer 15, it is possible to effectively narrow the imaging range of each light receiving element 20, making it possible to further increase the thickness of the substrate 12 or to capture clear images of objects far from the surface of the substrate 12.

[0122] Alternatively, a touch sensor panel may be used as the functional layer 15. As the touch sensor provided in the touch sensor panel, various types can be adopted, such as a resistive film type, a capacitance type, an infrared type, an electromagnetic induction type, a surface acoustic wave type, etc. In particular, it is preferable to use a capacitance type touch sensor as the touch sensor.

[0123] The functional layer 15 may have both the function as the optical member and the function as a touch sensor panel. Alternatively, the functional layer 15 may be a laminate in which a layer that functions as an optical member and a layer that functions as a touch sensor panel are stacked.

[0124] The functional layer 15 preferably has a resin layer containing a resin.

[0125] The thickness of the functional layer 15 is T F When the functional layer 15 has a resin layer, the thickness of the resin layer is set to the thickness T F The thickness T of the functional layer 15 can be regarded as F is the thickness T of the substrate 12 S It is preferable that the thickness of the functional layer 15 is smaller than T F is the thickness T of the resin layer 13 R1 , and the thickness T of the resin layer 14 R2 It is preferable that it is thicker than

[0126] The refractive index of the functional layer 15 with respect to the wavelength of the light 51 emitted by the light emitting element 30 is n F The refractive index n of the functional layer 15 is F is the refractive index n of the substrate 12 S It is preferable that it is lower than

[0127] The thickness of the resin layer 16 is T R3 The refractive index of the resin layer 16 is n R3 The thickness T of the resin layer 16 R3 is the thickness T of the substrate 12 S and the thickness T of the functional layer 15 F It is preferable that the thickness of the resin layer 16 is thinner than T R3 is the thickness T of the resin layer 13 R1 It is more preferable that the resin layer 16 is thinner than the refractive index n R3 is the refractive index n of the substrate 12 S It is preferable that it is lower than

[0128] The protective layer 42 is provided to cover the conductive layer 23. The protective layer 42 has the function of suppressing the diffusion of impurities such as water from the resin layer 13, etc., into the light receiving element 20 and the light emitting element 30. The protective layer 42 preferably contains at least an inorganic insulator, which can suitably suppress the diffusion of impurities such as water and improve reliability. The protective layer 42 can be, for example, a single layer of an inorganic insulating film, or a laminated structure of an organic insulating film and an inorganic insulating film.

[0129] When an inorganic insulating film is used for the protective layer 42, the refractive index tends to be higher than that of the resin layer 13. Therefore, it is preferable that the protective layer 42 is at least thinner than the resin layer 13. In this way, the provision of the protective layer 42 can suitably suppress a decrease in the amount of light incident on the light receiving element 20.

[0130] The conductive layer 43 is provided on the protective layer 42. The conductive layer 43 can function as, for example, wiring or an electrode of a touch sensor. The conductive layer 43 is preferably provided in a region overlapping with the light-shielding layer 25. This can prevent light reflected on the surface of the conductive layer 43 from being incident on the light-receiving element 20, thereby reducing noise in the captured image.

[0131] The conductive layer 43 is preferably thinner than the resin layer 13. This can improve the flatness of the upper surface of the resin layer 13, so that the thickness of the resin layer 14 and the like located above the light receiving element 20 can be made uniform within the display area, enabling a clear image to be captured.

[0132] The conductive layer 43 is not limited to being used as a wiring for a touch sensor, but may also be used as an electrode for a capacitor element, a transistor, a display element, a sensor element, or the like, or as a wiring electrically connected to these elements.

[0133] [Configuration Example 2-2] 5 shows a schematic cross-sectional view of the display device 10b. The display device 10b differs from the display device 10a mainly in that it has a protective layer 17, a different configuration of the light-shielding layer 25, and does not have the conductive layer 43.

[0134] The protective layer 17 is provided between the resin layer 13 and the resin layer 14. The protective layer 17 has the function of preventing impurities such as water from diffusing from the resin layer 14 to the resin layer 13 side.

[0135] An inorganic insulating film can be used as the protective layer 17. Alternatively, a sheet-like or plate-like member containing a resin or an inorganic insulator may be used as the protective layer 17. When a sheet-like or plate-like member is used for the protective layer 17, the protective layer 17 can function as an opposing substrate provided opposite the substrate 11.

[0136] The light-shielding layer 25 is provided on the surface of the protective layer 17 facing the substrate 11. The resin layer 13 functions as an adhesive layer that bonds the substrate 11 (specifically, the upper surface of the protective layer 42) and the protective layer 17 together.

[0137] The thickness of the protective layer 17 is T B The refractive index of the protective layer 17 is n B The thickness T of the protective layer 17 B is the thickness T of the substrate 12 S The thickness of the protective layer 17 is preferably less than the refractive index n B is the refractive index n of the substrate 12 S It is preferable that it is lower than

[0138] In the display device 10b, the functional layer 15 preferably functions as a touch sensor panel. The following describes the functional layer 15 that functions as a touch sensor panel.

[0139] 6A shows a perspective view of a portion of the functional layer 15 that functions as a touch sensor panel. The functional layer 15 includes a resin layer 55, a plurality of conductive layers 56a, and a plurality of conductive layers 56b. In FIG. 6A, the resin layer 55 is indicated by a dashed line.

[0140] The conductive layers 56a have a strip shape extending in one direction. The conductive layers 56b also have a strip shape extending in a direction intersecting the conductive layers 56a. The plurality of conductive layers 56a and the plurality of conductive layers 56b are arranged at equal intervals.

[0141] For example, in the case of a mutual capacitance type touch sensor of electrostatic capacitance type, a pulse signal is applied to one of the conductive layer 56a and the conductive layer 56b, and an amplifier circuit or the like is connected to the other.

[0142] 6B shows a schematic cross-sectional view of the functional layer 15. The conductive layers 56a are provided side by side on one surface of the resin layer 55. The conductive layers 56b are provided on the other surface of the resin layer 55.

[0143] The conductive layers 56a and 56b are preferably formed using a light-transmitting conductive film, such as a metal oxide.

[0144] Alternatively, a metal film processed into a mesh shape may be used for the conductive layers 56a and 56b. In this case, it is preferable that the light receiving elements 20, the light emitting elements 30, etc. are positioned in the openings of the mesh in a plan view. The metal film may also serve as the light-shielding layer 25. This allows the distance between the light-shielding layer and the light receiving elements 20 to be longer, thereby further narrowing the imaging range of each light receiving element 20 and enabling clearer images to be captured.

[0145] 6C shows a perspective view of a functional layer 15 having a different configuration from that described above. The functional layer 15 shown in FIG. 6C includes a resin layer 55, a conductive layer 56a, a conductive layer 56b, a conductive layer 57, and the like.

[0146] The conductive layers 56a and 56b are provided on the same surface, and are preferably formed by processing the same conductive film.

[0147] The conductive layer 56a has a plurality of portions each having a diamond-shaped upper surface and portions connecting these portions. On the other hand, the conductive layer 56b has an island-like shape also having a diamond-shaped upper surface. Two adjacent conductive layers 56b are electrically connected by a conductive layer 57.

[0148] FIG. 6D shows an example of a cross section of the functional layer 15 shown in FIG. 6C.

[0149] Conductive layer 56a and conductive layer 56b are provided on resin layer 55. FIG. 6D shows a pair of conductive layers 56b sandwiching conductive layer 56a. An insulating layer 58 is provided to cover conductive layer 56a and conductive layer 56b, and a conductive layer 57 is provided on insulating layer 58. Conductive layer 57 is electrically connected to each of conductive layers 56b through two openings provided in insulating layer 58. As a result, the pair of conductive layers 56b are electrically connected via conductive layer 57.

[0150] 6E shows an example in which the conductive layer 57 is disposed closer to the resin layer 55 than the insulating layer 58. The conductive layer 57 is provided on the resin layer 55, and the insulating layer 58 is provided to cover the conductive layer 57. Furthermore, the conductive layers 56a and 56b are provided on the insulating layer 58. The pair of conductive layers 56b are electrically connected to the conductive layer 57 at openings provided in the insulating layer 58.

[0151] The above is a description of the functional layer 15 that functions as a touch sensor panel.

[0152] The display device exemplified in this embodiment has high mechanical strength and a function of capturing clear images. For example, by applying the display device to a display portion (screen) of an electronic device such as a smartphone, a tablet terminal, or a wristwatch-type terminal, it is possible to realize an electronic device that is highly convenient, multifunctional, and has a screen that is not easily damaged.

[0153] At least a part of the configuration examples exemplified in this embodiment and the corresponding drawings can be combined as appropriate with other configuration examples or drawings.

[0154] This embodiment mode can be implemented by appropriately combining at least a part thereof with other embodiment modes described in this specification.

[0155] (Embodiment 2) In this embodiment, a display device according to one embodiment of the present invention will be described.

[0156] A display portion of a display device according to one embodiment of the present invention includes a light-receiving element (also referred to as a light-receiving device) and a light-emitting element (also referred to as a light-emitting device). The display portion has a function of displaying an image using the light-emitting element. Furthermore, the display portion has one or both of an imaging function and a sensing function using the light-receiving element.

[0157] Alternatively, the display device of one embodiment of the present invention may have a structure including a light-emitting and light-emitting element (also referred to as a light-emitting and light-receiving device) and a light-emitting element.

[0158] First, a display device having a light receiving element and a light emitting element will be described.

[0159] The description of the first embodiment can be applied to the light receiving element and the light emitting element.

[0160] When the light receiving element is used as an image sensor, the display device can capture an image using the light receiving element, for example, the display device can be used as a scanner.

[0161] An electronic device to which the display device of one embodiment of the present invention is applied can acquire data related to biometric information such as a fingerprint or palm print by using a function as an image sensor. That is, a biometric authentication sensor can be built into the display device. The built-in biometric authentication sensor in the display device reduces the number of components in the electronic device compared to a case in which a biometric authentication sensor is provided separately from the display device, and the electronic device can be made smaller and lighter.

[0162] Furthermore, when the light receiving element is used as a touch sensor, the display device can detect a touch operation of an object using the light receiving element.

[0163] In one embodiment of the present invention, an organic EL element (also referred to as an organic EL device) is used as a light-emitting element, and an organic photodiode is used as a light-receiving element. The organic EL element and the organic photodiode can be formed on the same substrate. Therefore, the organic photodiode can be built into a display device using the organic EL element.

[0164] If all the layers constituting the organic EL element and the organic photodiode were to be fabricated separately, the number of film formation processes would be enormous. However, since the organic photodiode has many layers that can be configured in common with the organic EL element, the layers that can be configured in common can be formed in one go, thereby suppressing the increase in film formation processes.

[0165] For example, one of the pair of electrodes (common electrode) can be a layer common to the light-receiving element and the light-emitting element. It is also preferable that at least one of the hole injection layer, hole transport layer, electron transport layer, and electron injection layer be a layer common to the light-receiving element and the light-emitting element. Furthermore, the light-receiving element and the light-emitting element can have the same configuration, except that the light-receiving element has an active layer and the light-emitting element has an emitting layer. That is, a light-receiving element can be fabricated simply by replacing the emitting layer of the light-emitting element with an active layer. By having a common layer between the light-receiving element and the light-emitting element, the number of film formations and the number of masks can be reduced, thereby reducing the manufacturing process and manufacturing costs of the display device. Furthermore, a display device having a light-receiving element can be fabricated using existing display device manufacturing equipment and manufacturing methods.

[0166] Note that a layer common to a light-receiving element and a light-emitting element may have different functions in the light-emitting element and the light-receiving element. In this specification, components are named based on their functions in the light-emitting element. For example, a hole injection layer functions as a hole injection layer in the light-emitting element and functions as a hole transport layer in the light-receiving element. Similarly, an electron injection layer functions as an electron injection layer in the light-emitting element and functions as an electron transport layer in the light-receiving element. Furthermore, a layer common to a light-receiving element and a light-emitting element may have the same function in the light-emitting element and the light-receiving element. A hole transport layer functions as a hole transport layer in both the light-emitting element and the light-receiving element, and an electron transport layer functions as an electron transport layer in both the light-emitting element and the light-receiving element.

[0167] Next, a display device having light emitting and receiving elements and a light emitting element will be described. Note that the description of the same functions, actions, effects, etc. as those described above may be omitted.

[0168] In a display device according to one embodiment of the present invention, a subpixel that exhibits one of the colors has a light-receiving and light-emitting element instead of a light-emitting element, and a subpixel that exhibits the other color has a light-emitting element. The light-receiving and light-emitting element has both a function of emitting light (light-emitting function) and a function of receiving light (light-receiving function). For example, when a pixel has three subpixels, namely, a red subpixel, a green subpixel, and a blue subpixel, at least one subpixel has a light-receiving and light-emitting element, and the other subpixels have light-emitting elements. Therefore, the display portion of the display device according to one embodiment of the present invention has a function of displaying an image using both the light-receiving and light-emitting elements and the light-emitting elements.

[0169] By using a light-receiving / light-emitting element that serves as both a light-emitting element and a light-receiving element, a pixel can be given a light-receiving function without increasing the number of subpixels included in the pixel. This allows one or both of an imaging function and a sensing function to be added to the display portion of the display device while maintaining the aperture ratio of the pixel (aperture ratio of each subpixel) and the resolution of the display device. Therefore, the display device of one embodiment of the present invention can have a higher aperture ratio of the pixel and can easily achieve higher resolution than a display device in which a subpixel having a light-receiving element is provided separately from a subpixel having a light-emitting element.

[0170] In a display device according to one embodiment of the present invention, light-emitting and light-emitting elements are arranged in a matrix in a display portion, and an image can be displayed on the display portion. The display portion can also be used as an image sensor, a touch sensor, or the like. The light-emitting element can be used as a light source for the sensor in the display device according to one embodiment of the present invention. Therefore, imaging and detection of touch operations can be achieved even in a dark place.

[0171] Light-emitting and receiving elements can be fabricated by combining an organic EL element and an organic photodiode. For example, light-emitting and receiving elements can be fabricated by adding the active layer of an organic photodiode to the layered structure of an organic EL element. Furthermore, light-emitting and receiving elements fabricated by combining an organic EL element and an organic photodiode can suppress an increase in the number of film-forming steps by forming layers that can be configured in common with the organic EL element in a single step.

[0172] For example, one of the pair of electrodes (common electrode) can be a layer common to the light-emitting and receiving elements and the light-emitting element. It is also preferable that at least one of the hole injection layer, hole transport layer, electron transport layer, and electron injection layer be a layer common to the light-emitting and receiving elements and the light-emitting element. Furthermore, the light-emitting and receiving elements and the light-emitting element can have the same configuration, except for the presence or absence of an active layer of the light-receiving element. In other words, the light-emitting and receiving elements can be fabricated simply by adding the active layer of the light-receiving element to the light-emitting element. Having a common layer between the light-emitting and receiving elements and the light-emitting element in this way can reduce the number of film formations and masks, thereby reducing the manufacturing process and manufacturing costs of the display device. Furthermore, a display device having a light-emitting and receiving element can be fabricated using existing display device manufacturing equipment and manufacturing methods.

[0173] Note that the layers of the light emitting / receiving element may have different functions depending on whether the light emitting / receiving element functions as a light receiving element or a light emitting element. In this specification, the components are referred to based on their functions when the light emitting / receiving element functions as a light emitting element.

[0174] The display device of this embodiment mode has a function of displaying an image using a light-emitting element and a light-emitting / light-emitting element. That is, the light-emitting element and the light-emitting / light-emitting element function as display elements.

[0175] The display device of this embodiment has a function of detecting light using a light receiving and emitting element, which can detect light having a shorter wavelength than light emitted by the light receiving and emitting element itself.

[0176] When the light-emitting / receiving elements are used as an image sensor, the display device of this embodiment can capture an image using the light-emitting / receiving elements. When the light-emitting / receiving elements are used as a touch sensor, the display device of this embodiment can detect a touch operation of an object using the light-emitting / receiving elements.

[0177] The light-receiving / light-emitting element functions as a photoelectric conversion element. The light-receiving / light-emitting element can be fabricated by adding an active layer of a light-receiving element to the configuration of the light-emitting element. For example, the active layer of a pn-type or pin-type photodiode can be used for the light-receiving / light-emitting element.

[0178] In particular, it is preferable to use an organic photodiode active layer having a layer containing an organic compound as the light-receiving / light-emitting element. Organic photodiodes can be easily made thin, lightweight, and large in area, and have a high degree of freedom in shape and design, making them applicable to a variety of display devices.

[0179] The display device of one embodiment of the present invention will be described in more detail below with reference to the drawings.

[0180] [Display device configuration example 1] [Configuration Example 1-1] 7A is a schematic diagram of a display panel 200. The display panel 200 includes a substrate 201, a substrate 202, a light receiving element 212, a light emitting element 211R, a light emitting element 211G, a light emitting element 211B, a functional layer 203, and the like.

[0181] The light-emitting element 211R, the light-emitting element 211G, the light-emitting element 211B, and the light-receiving element 212 are provided between the substrate 201 and the substrate 202. The light-emitting element 211R, the light-emitting element 211G, and the light-emitting element 211B emit red (R), green (G), or blue (B) light, respectively. Note that hereinafter, when there is no need to distinguish between the light-emitting element 211R, the light-emitting element 211G, and the light-emitting element 211B, they may be referred to as the light-emitting element 211.

[0182] The display panel 200 has a plurality of pixels arranged in a matrix. Each pixel has one or more sub-pixels. Each sub-pixel has one light-emitting element. For example, a pixel may have three sub-pixels (e.g., three colors of R, G, and B, or three colors of yellow (Y), cyan (C), and magenta (M)), or four sub-pixels (e.g., four colors of R, G, B, and white (W), or four colors of R, G, B, and Y). Each pixel also has a light-receiving element 212. The light-receiving element 212 may be provided in all pixels or in some of the pixels. Alternatively, one pixel may have multiple light-receiving elements 212.

[0183] 7A shows a state in which finger 220 touches the surface of substrate 202. A portion of the light emitted by light-emitting element 211G is reflected at the contact point between substrate 202 and finger 220. A portion of the reflected light is then incident on light-receiving element 212, thereby making it possible to detect that finger 220 has touched substrate 202. In other words, display panel 200 can function as a touch panel.

[0184] The functional layer 203 has a circuit for driving the light-emitting element 211R, the light-emitting element 211G, and the light-emitting element 211B, and a circuit for driving the light-receiving element 212. The functional layer 203 is provided with switches, transistors, capacitors, wiring, and the like. Note that when the light-emitting element 211R, the light-emitting element 211G, the light-emitting element 211B, and the light-receiving element 212 are driven by a passive matrix method, a configuration without switches, transistors, and the like may be adopted.

[0185] It is preferable that the display panel 200 has a function for detecting the fingerprint of a finger 220. Fig. 7B is a schematic enlarged view of a contact portion when the finger 220 is in contact with the substrate 202. Fig. 7B also shows light emitting elements 211 and light receiving elements 212 arranged alternately.

[0186] A fingerprint is formed by concave and convex portions of finger 220. Therefore, the convex portions of the fingerprint are in contact with substrate 202 as shown in FIG.

[0187] Light reflected from a surface or interface can be classified as specular or diffuse. Specular reflected light is highly directional, with the angle of incidence and the angle of reflection matching, while diffuse reflected light is less directional, with its intensity less dependent on the angle. The diffuse reflection component is dominant in the light reflected from the surface of the finger 220. On the other hand, the specular reflection component is dominant in the light reflected from the interface between the substrate 202 and the atmosphere.

[0188] The intensity of light reflected by the contact or non-contact surface between finger 220 and substrate 202 and incident on light receiving element 212 located directly below them is the sum of specularly reflected light and diffusely reflected light. As described above, at the concave portions of finger 220, substrate 202 and finger 220 do not come into contact, so specularly reflected light (indicated by solid arrows) is dominant, whereas at the convex portions, they come into contact, so diffusely reflected light (indicated by dashed arrows) from finger 220 is dominant. Therefore, the intensity of light received by light receiving element 212 located directly below the concave portions is higher than that of light receiving element 212 located directly below the convex portions. This makes it possible to capture an image of the fingerprint of finger 220.

[0189] A clear fingerprint image can be obtained by arranging the light receiving elements 212 at an interval smaller than the distance between two convex portions of a fingerprint, preferably the distance between adjacent concave and convex portions. Since the distance between concave and convex portions of a human fingerprint is generally between 150 μm and 250 μm, the interval between the light receiving elements 212 is set to, for example, 400 μm or less, preferably 200 μm or less, more preferably 150 μm or less, even more preferably 120 μm or less, even more preferably 100 μm or less, and even more preferably 50 μm or less. The smaller the arrangement interval, the better, but it can be set to, for example, 1 μm or more, 10 μm or more, or 20 μm or more.

[0190] An example of a fingerprint image captured by display panel 200 is shown in Fig. 7C. In Fig. 7C, the outline of finger 220 is indicated by a dashed line and the outline of contact area 221 is indicated by a dashed line within imaging area 223. Within contact area 221, a fingerprint 222 with high contrast can be captured due to differences in the amount of light incident on light receiving element 212.

[0191] The display panel 200 can also function as a touch panel, a pen tablet, etc. Fig. 7D shows a state in which the tip of a stylus 225 is in contact with the substrate 202 and is slid in the direction of the dashed arrow.

[0192] As shown in Figure 7D, the diffuse reflected light scattered by the tip of the stylus 225 and the contact surface of the substrate 202 is incident on the light receiving element 212 located at the part overlapping with the contact surface, thereby enabling the position of the tip of the stylus 225 to be detected with high accuracy.

[0193] 7E shows an example of a trajectory 226 of the stylus 225 detected by the display panel 200. The display panel 200 is capable of detecting the position of a detectable object such as the stylus 225 with high positional accuracy, and therefore is also capable of performing high-resolution drawing in drawing applications and the like. Furthermore, unlike when a capacitance-type touch sensor, an electromagnetic induction-type touch pen, or the like is used, the position of even a highly insulating detectable object can be detected, and therefore the material of the tip of the stylus 225 is not a factor, and various writing implements (for example, a brush, a glass pen, a feather pen, etc.) can be used.

[0194] 7F to 7H show an example of a pixel that can be applied to the display panel 200. FIG.

[0195] 7F and 7G each have a red (R) light-emitting element 211R, a green (G) light-emitting element 211G, a blue (B) light-emitting element 211B, and a light-receiving element 212. The pixel has a pixel circuit for driving the light-emitting element 211R, the light-emitting element 211G, the light-emitting element 211B, and the light-receiving element 212, respectively.

[0196] Fig. 7F shows an example in which three light-emitting elements and one light-receiving element are arranged in a 2 x 2 matrix. Fig. 7G shows an example in which three light-emitting elements are arranged in a row, and one horizontally elongated light-receiving element 212 is arranged below them.

[0197] 7H is an example of a pixel having a white (W) light-emitting element 211W. Here, four light-emitting elements are arranged in a row, and a light-receiving element 212 is arranged below them.

[0198] The pixel configuration is not limited to the above, and various arrangement methods can be adopted.

[0199] [Configuration Example 1-2] In the following, an example of a configuration including a light-emitting element that emits visible light, a light-emitting element that emits infrared light, and a light-receiving element will be described.

[0200] The display panel 200A shown in Fig. 8A has a light-emitting element 211IR in addition to the configuration exemplified in Fig. 7A. The light-emitting element 211IR is a light-emitting element that emits infrared light IR. In this case, it is preferable to use an element that can receive at least the infrared light IR emitted by the light-emitting element 211IR as the light-receiving element 212. It is more preferable to use an element that can receive both visible light and infrared light as the light-receiving element 212.

[0201] As shown in FIG. 8A, when a finger 220 touches the substrate 202, infrared light IR emitted from the light-emitting element 211IR is reflected by the finger 220, and a portion of the reflected light is incident on the light-receiving element 212, thereby obtaining position information of the finger 220.

[0202] 8B to 8D show examples of pixels applicable to the display panel 200A.

[0203] Fig. 8B shows an example in which three light-emitting elements are arranged in a row, and below them, light-emitting element 211IR and light-receiving element 212 are arranged side by side. Fig. 8C shows an example in which four light-emitting elements including light-emitting element 211IR are arranged in a row, and below them, light-receiving element 212 is arranged.

[0204] FIG. 8D shows an example in which three light emitting elements and a light receiving element 212 are arranged on all four sides with light emitting element 211IR at the center.

[0205] In the pixels shown in FIGS. 8B to 8D, the positions of the light-emitting elements and the light-emitting elements and the light-receiving elements can be interchanged.

[0206] [Configuration Example 1-3] In the following, an example of a configuration including a light-emitting element that emits visible light and a light-receiving / light-emitting element that emits visible light and receives visible light will be described.

[0207] The display panel 200B shown in FIG. 9A includes a light-emitting element 211B, a light-emitting element 211G, and a light-receiving / light-emitting element 213R. The light-receiving / light-emitting element 213R functions as a light-emitting element that emits red (R) light and as a photoelectric conversion element that receives visible light. FIG. 9A shows an example in which the light-receiving / light-emitting element 213R receives green (G) light emitted by the light-emitting element 211G. The light-receiving / light-emitting element 213R may also receive blue (B) light emitted by the light-emitting element 211B. The light-receiving / light-emitting element 213R may also receive both green light and blue light.

[0208] For example, it is preferable that the light receiving / emitting element 213R receives light with a shorter wavelength than the light it emits. Alternatively, the light receiving / emitting element 213R may be configured to receive light with a longer wavelength than the light it emits (for example, infrared light). The light receiving / emitting element 213R may be configured to receive light with a wavelength similar to the light it emits, but in that case, it may also receive the light it emits, which could reduce the light emission efficiency. Therefore, it is preferable that the light receiving / emitting element 213R is configured so that the peak of the emission spectrum and the peak of the absorption spectrum do not overlap as much as possible.

[0209] In addition, the light emitted by the light emitting / receiving element is not limited to red light. Furthermore, the light emitted by the light emitting element is not limited to a combination of green light and blue light. For example, the light emitting / receiving element may be an element that emits green or blue light and receives light of a wavelength different from the light it emits.

[0210] In this way, by having the light emitting / receiving element 213R function as both a light emitting element and a light receiving element, the number of elements arranged in one pixel can be reduced, which makes it easier to achieve higher definition, a higher aperture ratio, and higher resolution.

[0211] 9B to 9I show an example of a pixel that can be applied to the display panel 200B.

[0212] Fig. 9B shows an example in which the light emitting / receiving element 213R, the light emitting element 211G, and the light emitting element 211B are arranged in a row. Fig. 9C shows an example in which the light emitting element 211G and the light emitting element 211B are arranged alternately in the vertical direction, and the light emitting / receiving element 213R is arranged next to them.

[0213] FIG. 9D shows an example in which three light-emitting elements (light-emitting element 211G, light-emitting element 211B, and light-emitting element 211X) and one light-receiving / light-emitting element are arranged in a 2×2 matrix. Light-emitting element 211X is an element that emits light other than R, G, and B. Examples of light other than R, G, and B include white (W), yellow (Y), cyan (C), magenta (M), infrared light (IR), and ultraviolet light (UV). When light-emitting element 211X emits infrared light, it is preferable that the light-receiving / light-emitting element has a function of detecting infrared light or a function of detecting both visible light and infrared light. The wavelength of light detected by the light-receiving / light-emitting element can be determined depending on the application of the sensor.

[0214] FIG. 9E shows two pixels. An area including three elements surrounded by a dotted line corresponds to one pixel. Each pixel has a light-emitting element 211G, a light-emitting element 211B, and an optical element 213R. In the left pixel shown in FIG. 9E, the light-emitting element 211G is arranged in the same row as the optical element 213R, and the light-emitting element 211B is arranged in the same column as the optical element 213R. In the right pixel shown in FIG. 9E, the light-emitting element 211G is arranged in the same row as the optical element 213R, and the light-emitting element 211B is arranged in the same column as the optical element 211G. In the pixel layout shown in FIG. 9E, the optical element 213R, the light-emitting element 211G, and the light-emitting element 211B are arranged repeatedly in both odd-numbered and even-numbered rows, and in each column, optical elements or optical elements of different colors are arranged in the odd-numbered and even-numbered rows.

[0215] Figure 9F shows four pixels in a Pentile arrangement, with adjacent pixels each having a light-emitting or light-receiving element that emits two different colors of light. Figure 9F also shows the top view of the light-emitting or light-receiving element.

[0216] The upper left pixel and lower right pixel shown in Fig. 9F have light emitting / receiving element 213R and light emitting element 211G. The upper right pixel and lower left pixel have light emitting element 211G and light emitting element 211B. That is, in the example shown in Fig. 9F, each pixel is provided with light emitting element 211G.

[0217] The top surface shapes of the light-emitting element and light-receiving / light-emitting element are not particularly limited and may be circular, elliptical, polygonal, polygonal with rounded corners, etc. Figure 9F etc. shows an example in which the top surface shapes of the light-emitting element and light-receiving / light-emitting element are squares (diamonds) tilted at approximately 45 degrees. Note that the top surface shapes of the light-emitting element and light-receiving / light-emitting element for each color may be different from each other, or may be the same for some or all of the colors.

[0218] Furthermore, the sizes of the light-emitting regions (or light-receiving and light-emitting regions) of the light-emitting elements and light-receiving and light-emitting elements of each color may be different from each other, or may be the same for some or all colors. For example, in FIG. 9F, the area of ​​the light-emitting region of the light-emitting element 211G provided in each pixel may be smaller than the light-emitting regions (or light-receiving and light-emitting regions) of the other elements.

[0219] Fig. 9G is a modified example of the pixel array shown in Fig. 9F. Specifically, the configuration in Fig. 9G is obtained by rotating the configuration in Fig. 9F by 45 degrees. Although Fig. 9F has been described as having two elements per pixel, it can also be understood that one pixel is made up of four elements, as shown in Fig. 9G.

[0220] FIG. 9H is a modified example of the pixel array shown in FIG. 9F. The upper left pixel and lower right pixel shown in FIG. 9H have light emitting / receiving elements 213R and light emitting elements 211G. The upper right pixel and lower left pixel have light emitting / receiving elements 213R and light emitting elements 211B. That is, in the example shown in FIG. 9H, each pixel is provided with a light emitting / receiving element 213R. Because each pixel is provided with a light emitting / receiving element 213R, the configuration shown in FIG. 9H can capture images with higher resolution than the configuration shown in FIG. 9F. This can improve the accuracy of biometric authentication, for example.

[0221] FIG. 9I is a modified example of the pixel array shown in FIG. 9H, and is obtained by rotating the pixel array by 45 degrees.

[0222] In FIG. 9I, a description will be given assuming that one pixel is composed of four elements (two light-emitting elements and two light-receiving and light-emitting elements). In this way, one pixel has multiple light-receiving and light-emitting elements with a light-receiving function, allowing for high-resolution imaging. This can improve the accuracy of biometric authentication. For example, the resolution of imaging can be set to the root double of the resolution of display.

[0223] A display device to which the configuration shown in Figure 9H or Figure 9I 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 element emits green light, and the other emits blue light. The light-receiving and light-emitting element emits red light and has a light-receiving function.

[0224] For example, when detecting a touch operation using a light-emitting / receiving element, it is preferable that the light emitted from the light source is less visible to the user. Because blue light is less visible than green light, it is preferable that a light-emitting element that emits blue light be used as the light source. Therefore, it is preferable that the light-emitting / receiving element has a function of receiving blue light. However, this is not limited to this, and the light-emitting element used as the light source can be appropriately selected depending on the sensitivity of the light-emitting / receiving element.

[0225] As described above, pixels with various arrangements can be applied to the display device of this embodiment mode.

[0226] [Device Structure] Next, detailed structures of a light-emitting element, a light-receiving element, and a light-emitting and light-emitting element that can be used in the display device of one embodiment of the present invention will be described.

[0227] The display device of one embodiment of the present invention may be any of a top emission type that emits light in a direction opposite to a substrate on which a light-emitting element is formed, a bottom emission type that emits light toward a substrate on which a light-emitting element is formed, and a dual emission type that emits light to both sides.

[0228] In this embodiment, a top-emission display device will be described as an example.

[0229] In this specification, unless otherwise specified, even when describing a configuration having a plurality of elements (light-emitting elements, light-emitting layers, etc.), when describing matters common to each element, the alphabet will be omitted. For example, when describing matters common to light-emitting layer 283R and light-emitting layer 283G, etc., they may be referred to as light-emitting layer 283.

[0230] A display device 280A shown in FIG. 10A has a light receiving element 270PD, a light emitting element 270R that emits red (R) light, a light emitting element 270G that emits green (G) light, and a light emitting element 270B that emits blue (B) light.

[0231] Each light-emitting element has a pixel electrode 271, a hole injection layer 281, a hole transport layer 282, a light-emitting layer, an electron transport layer 284, an electron injection layer 285, and a common electrode 275 stacked in this order. Light-emitting element 270R has a light-emitting layer 283R, light-emitting element 270G has a light-emitting layer 283G, and light-emitting element 270B has a light-emitting layer 283B. Light-emitting layer 283R contains a light-emitting material that emits red light, light-emitting layer 283G contains a light-emitting material that emits green light, and light-emitting layer 283B contains a light-emitting material that emits blue light.

[0232] The light emitting element is an electroluminescent element that emits light toward the common electrode 275 when a voltage is applied between the pixel electrode 271 and the common electrode 275 .

[0233] The light receiving element 270PD has a pixel electrode 271, a hole injection layer 281, a hole transport layer 282, an active layer 273, an electron transport layer 284, an electron injection layer 285, and a common electrode 275 stacked in this order.

[0234] The light receiving element 270PD is a photoelectric conversion element that receives light incident from outside the display device 280A and converts it into an electrical signal.

[0235] In this embodiment, in both the light-emitting element and the light-receiving element, the pixel electrode 271 functions as an anode, and the common electrode 275 functions as a cathode. In other words, by applying a reverse bias between the pixel electrode 271 and the common electrode 275 and driving the light-receiving element, the light incident on the light-receiving element can be detected, an electric charge can be generated, and the electric charge can be extracted as a current.

[0236] In the display device of this embodiment, an organic compound is used for the active layer 273 of the light-receiving element 270PD. The layers of the light-receiving element 270PD other than the active layer 273 can be configured in common with the light-emitting element. Therefore, by simply adding a step of forming the active layer 273 to the manufacturing process of the light-emitting element, the light-receiving element 270PD can be formed in parallel with the formation of the light-emitting element. Furthermore, the light-emitting element and the light-receiving element 270PD can be formed on the same substrate. Therefore, the light-receiving element 270PD can be incorporated into the display device without significantly increasing the number of manufacturing steps.

[0237] The display device 280A shows an example in which the light receiving element 270PD and the light emitting element have a common configuration, except that the active layer 273 of the light receiving element 270PD and the light emitting layer 283 of the light emitting element are fabricated separately. However, the configuration of the light receiving element 270PD and the light emitting element is not limited to this. The light receiving element 270PD and the light emitting element may have layers fabricated separately from each other, in addition to the active layer 273 and the light emitting layer 283. It is preferable that the light receiving element 270PD and the light emitting element have one or more layers used in common (common layers). This allows the light receiving element 270PD to be incorporated into the display device without significantly increasing the number of manufacturing steps.

[0238] A conductive film that transmits visible light is used for the electrode from which light is extracted, between the pixel electrode 271 and the common electrode 275. It is preferable to use a conductive film that reflects visible light for the electrode from which light is not extracted.

[0239] The light-emitting element included in the display device of this embodiment preferably has a micro-optical resonator (microcavity) structure. Therefore, one of a pair of electrodes included in the light-emitting element preferably has an electrode that is transparent and reflective to visible light (semi-transmissive / semi-reflective electrode), and the other preferably has an electrode that is reflective to visible light (reflective electrode). When the light-emitting element has a microcavity structure, light emitted from the light-emitting layer can be resonated between both electrodes, thereby intensifying the light emitted from the light-emitting element.

[0240] The semi-transmitting / semi-reflective electrode can have a laminated structure of a reflective electrode and an electrode that is transparent to visible light (also called a transparent electrode).

[0241] The light transmittance of the transparent electrode is 40% or more. For example, it is preferable to use an electrode with a visible light (light with a wavelength of 400 nm or more and less than 750 nm) transmittance of 40% or more for the light emitting element. The visible light reflectance of the semi-transmissive / semi-reflective electrode is 10% or more and 95% or less, preferably 30% or more and 80% or less. The visible light reflectance of the reflective electrode is 40% or more and 100% or less, preferably 70% or more and 100% or less. In addition, the resistivity of these electrodes is 1×10 -2 When the light-emitting element emits near-infrared light (light with a wavelength of 750 nm or more and 1300 nm or less), the transmittance or reflectance of these electrodes for near-infrared light preferably satisfies the above-mentioned numerical range, similar to the transmittance or reflectance for visible light.

[0242] The light-emitting element has at least the light-emitting layer 283. The light-emitting element may further have, in addition to the light-emitting layer 283, a layer containing a substance with high hole-injection properties, a substance with high hole-transport properties, a hole-blocking material, a substance with high electron-transport properties, a substance with high electron-injection properties, an electron-blocking material, a bipolar substance (a substance with high electron-transport properties and high hole-transport properties), or the like.

[0243] For example, the light-emitting element and the light-receiving element may have one or more layers of the hole injection layer, hole transport layer, electron transport layer, and electron injection layer in common, or the light-emitting element and the light-receiving element may have one or more layers of the hole injection layer, hole transport layer, electron transport layer, and electron injection layer formed differently from each other.

[0244] The hole injection layer is a layer that injects holes from the anode into the hole transport layer and contains a material with high hole injection properties, such as a composite material containing a hole transport material and an acceptor material (electron acceptor material), or an aromatic amine compound.

[0245] In a light-emitting element, the hole transport layer is a layer that transports holes injected from the anode by the hole injection layer to the light-emitting layer. In a light-receiving element, the hole transport layer is a layer that transports holes generated in the active layer based on incident light to the anode. The hole transport layer is a layer that contains a hole transport material. The hole transport material is a material having a concentration of 1×10 -6 cm 2 A material having a hole mobility of 1 / Vs or more is preferred. 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 preferred.

[0246] In a light-emitting element, the electron transport layer is a layer that transports electrons injected from the cathode by the electron injection layer to the light-emitting layer. In a light-receiving element, the electron transport layer is a layer that transports electrons generated in the active layer based on incident light to the cathode. The electron transport layer is a layer that contains an electron transporting material. The electron transporting material is a material having a 1×10 -6 cm 2A substance having an electron mobility of 1 / Vs or more is preferred. Note that other substances can also be used as long as they have a higher electron transporting property than holes. Examples of electron-transporting materials that can be used include metal complexes having a quinoline skeleton, metal complexes having a benzoquinoline skeleton, metal complexes having an oxazole skeleton, and metal complexes having a thiazole skeleton, as well as oxadiazole derivatives, triazole derivatives, imidazole derivatives, oxazole derivatives, thiazole derivatives, phenanthroline derivatives, quinoline derivatives having a quinoline ligand, benzoquinoline derivatives, quinoxaline derivatives, dibenzoquinoxaline derivatives, pyridine derivatives, bipyridine derivatives, pyrimidine derivatives, and π-electron-deficient heteroaromatic compounds including nitrogen-containing heteroaromatic compounds.

[0247] The electron injection layer is a layer that injects electrons from the cathode to the electron transport layer and contains a material with high electron injection properties. Examples of the material with high electron injection properties include alkali metals, alkaline earth metals, and compounds thereof. Examples of the material with high electron injection properties include a composite material containing an electron transport material and a donor material (electron donor material).

[0248] The light-emitting layer 283 is a layer containing a light-emitting substance. The light-emitting layer 283 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. Furthermore, as the light-emitting substance, a substance that emits near-infrared light can also be used.

[0249] Examples of light-emitting materials include fluorescent materials, phosphorescent materials, TADF materials, and quantum dot materials.

[0250] 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.

[0251] Examples of phosphorescent materials include organometallic complexes (particularly iridium complexes) having a 4H-triazole skeleton, a 1H-triazole skeleton, an imidazole skeleton, a pyrimidine skeleton, a pyrazine skeleton, or a pyridine skeleton; organometallic complexes (particularly iridium complexes) having a phenylpyridine derivative having an electron-withdrawing group as a ligand; platinum complexes; and rare earth metal complexes.

[0252] The light-emitting layer 283 may contain one or more organic compounds (host materials, assist materials, etc.) in addition to a light-emitting substance (guest material). As the one or more organic compounds, one or both of a hole-transporting material and an electron-transporting material can be used. Furthermore, as the one or more organic compounds, a bipolar material or a TADF material can be used.

[0253] The light-emitting layer 283 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. This structure allows efficient emission using Exciplex-Triplet Energy Transfer (ExTET), which is energy transfer from an exciplex to a light-emitting substance (phosphorescent material). By selecting a combination that forms an exciplex that emits light that overlaps with the wavelength of the lowest-energy absorption band of the light-emitting substance, the energy transfer becomes smooth and light emission can be achieved efficiently. This structure simultaneously enables high efficiency, low-voltage operation, and long life of the light-emitting element.

[0254] As a combination of materials that form an exciplex, it is preferable that the HOMO level (highest occupied molecular orbital level) of the hole-transporting material is equal to or higher than the HOMO level of the electron-transporting material. It is also preferable that the LUMO level (lowest unoccupied molecular orbital level) of the hole-transporting material is equal to or higher than the LUMO level of the electron-transporting material. The LUMO level and HOMO level of the material can be derived from the electrochemical properties (reduction potential and oxidation potential) of the material measured by cyclic voltammetry (CV).

[0255] The formation of exciplexes can be confirmed, for example, by comparing the emission spectra of the hole-transporting material, the electron-transporting material, and the mixed film of these materials and observing the phenomenon that the emission spectrum of the mixed film is shifted to longer wavelengths than the emission spectra of each material (or has a new peak at longer wavelengths). Alternatively, it can be confirmed by comparing the transient photoluminescence (PL) of the hole-transporting material, the transient PL of the electron-transporting material, and the mixed film of these materials and observing differences in transient response, such as the transient PL lifetime of the mixed film having a longer-lived component or a larger proportion of delayed components than the transient PL lifetimes of the individual materials. The above-mentioned transient PL can also be interpreted as transient electroluminescence (EL). In other words, the formation of exciplexes can also be confirmed by comparing the transient EL of the hole-transporting material, the transient EL of the electron-transporting material, and the mixed film of these materials and observing differences in transient response.

[0256] The active layer 273 includes a semiconductor. Examples of the semiconductor include inorganic semiconductors such as silicon and organic semiconductors including organic compounds. In this embodiment, an example in which an organic semiconductor is used as the semiconductor included in the active layer 273 is shown. By using an organic semiconductor, the light-emitting layer 283 and the active layer 273 can be formed by the same method (for example, vacuum deposition), which is preferable because it allows the use of a common manufacturing device.

[0257] The active layer 273 has an n-type semiconductor material, such as fullerene (e.g., C 60 , C 70Examples of electron-accepting organic semiconductor materials include fullerene derivatives and other fullerenes. Fullerenes have a soccer ball-like shape, which is energetically stable. Fullerenes have deep (low) HOMO and LUMO levels. Because fullerenes have a deep LUMO level, they have extremely high electron-accepting (acceptor) properties. Normally, when the π-electron conjugation (resonance) spreads on a plane, as in benzene, the electron-donating (donor) properties increase, but fullerenes have a spherical shape, so they have high electron-accepting properties despite the large spread of π-electrons. High electron-accepting properties allow charge separation to occur quickly and efficiently, making them useful as light-receiving elements. C 60 , C 70 Both have a wide absorption band in the visible light region, especially C 70 is C 60 It is preferred because it has a larger π-electron conjugated system and a wide absorption band in the long wavelength region compared to the above.

[0258] 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.

[0259] Examples of the p-type semiconductor material of the active layer 273 include electron-donating organic semiconductor materials such as copper(II) phthalocyanine (CuPc), tetraphenyldibenzoperiflanthene (DBP), zinc phthalocyanine (ZnPc), tin phthalocyanine (SnPc), and quinacridone.

[0260] Examples of p-type semiconductor materials include carbazole derivatives, thiophene derivatives, furan derivatives, compounds having an aromatic amine skeleton, etc. Examples of p-type semiconductor materials include naphthalene derivatives, anthracene derivatives, pyrene derivatives, triphenylene derivatives, fluorene derivatives, pyrrole derivatives, benzofuran derivatives, benzothiophene derivatives, indole derivatives, dibenzofuran derivatives, dibenzothiophene derivatives, indolocarbazole derivatives, porphyrin derivatives, phthalocyanine derivatives, naphthalocyanine derivatives, quinacridone derivatives, polyphenylenevinylene derivatives, polyparaphenylene derivatives, polyfluorene derivatives, polyvinylcarbazole derivatives, polythiophene derivatives, etc.

[0261] 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.

[0262] It is preferable to use a spherical fullerene as the electron-accepting organic semiconductor material and a planar organic semiconductor material as the electron-donating organic semiconductor material. Molecules with similar shapes tend to aggregate together, and when molecules of the same type aggregate, the energy levels of their molecular orbitals become close, which can improve carrier transport properties.

[0263] For example, the active layer 273 is preferably formed by co-evaporating an n-type semiconductor and a p-type semiconductor, or alternatively, the active layer 273 may be formed by laminating an n-type semiconductor and a p-type semiconductor.

[0264] The light-emitting element and the light-receiving element can be made of either a low-molecular-weight compound or a high-molecular-weight compound, and may contain an inorganic compound. The layers constituting the light-emitting element and the light-receiving element can be formed by a method such as vapor deposition (including vacuum vapor deposition), a transfer method, a printing method, an inkjet method, or a coating method.

[0265] Display device 280B shown in FIG. 10B differs from display device 280A in that light receiving element 270PD and light emitting element 270R have the same configuration.

[0266] The light receiving element 270PD and the light emitting element 270R have the active layer 273 and the light emitting layer 283R in common.

[0267] Here, it is preferable that light receiving element 270PD has a common configuration with a light emitting element that emits light of a longer wavelength than the light to be detected. For example, light receiving element 270PD configured to detect blue light can have the same configuration as one or both of light emitting element 270R and light emitting element 270G. For example, light receiving element 270PD configured to detect green light can have the same configuration as light emitting element 270R.

[0268] By using a common configuration for the light receiving element 270PD and the light emitting element 270R, the number of film formation steps and the number of masks can be reduced compared to a configuration in which the light receiving element 270PD and the light emitting element 270R have separate layers, thereby reducing the manufacturing steps and manufacturing costs of the display device.

[0269] Furthermore, by using a common configuration for the light receiving element 270PD and the light emitting element 270R, the margin for misalignment can be narrowed compared to a configuration in which the light receiving element 270PD and the light emitting element 270R have separate layers. This allows for an increased pixel aperture ratio, improving the light extraction efficiency of the display device. This also extends the life of the light emitting element. Furthermore, the display device can display high brightness. Furthermore, it also allows for higher resolution display devices.

[0270] Light-emitting layer 283R includes a light-emitting material that emits red light. Active layer 273 includes an organic compound that absorbs light with a wavelength shorter than red (for example, one or both of green light and blue light). Active layer 273 preferably includes an organic compound that does not easily absorb red light and absorbs light with a wavelength shorter than red. This allows red light to be extracted efficiently from light-emitting element 270R, and light-receiving element 270PD to detect light with a wavelength shorter than red with high accuracy.

[0271] Furthermore, in the display device 280B, an example is shown in which the light emitting element 270R and the light receiving element 270PD have the same configuration, but the light emitting element 270R and the light receiving element 270PD may have optical adjustment layers of different thicknesses.

[0272] 11A and 11B includes a light receiving / emitting element 270SR, a light emitting element 270G, and a light emitting element 270B that emit red (R) light and have a light receiving function. The configuration of the light emitting element 270G and the light emitting element 270B can be based on the configuration of the display device 280A described above.

[0273] The light emitting / receiving element 270SR has, stacked in this order, a pixel electrode 271, a hole injection layer 281, a hole transport layer 282, an active layer 273, a light emitting layer 283R, an electron transport layer 284, an electron injection layer 285, and a common electrode 275. The light emitting / receiving element 270SR has the same configuration as the light emitting element 270R and the light receiving element 270PD exemplified in the display device 280B.

[0274] 11A shows a case where the light emitting / receiving element 270SR functions as a light emitting element. In FIG. 11A, an example is shown in which the light emitting element 270B emits blue light, the light emitting element 270G emits green light, and the light emitting / receiving element 270SR emits red light.

[0275] Fig. 11B shows a case where the light receiving / emitting element 270SR functions as a light receiving element. Fig. 11B shows an example where the light receiving / emitting element 270SR receives blue light emitted by the light emitting element 270B and green light emitted by the light emitting element 270G.

[0276] The light emitting element 270B, the light emitting element 270G, and the light emitting / receiving element 270SR each have a pixel electrode 271 and a common electrode 275. In the present embodiment, a case will be described as an example in which the pixel electrode 271 functions as an anode and the common electrode 275 functions as a cathode. The light emitting / receiving element 270SR is driven by applying a reverse bias between the pixel electrode 271 and the common electrode 275, whereby it can detect light incident on the light emitting / receiving element 270SR, generate electric charges, and extract the charges as a current.

[0277] The light emitting / receiving element 270SR can be said to have a configuration in which the active layer 273 is added to the light emitting element. In other words, the light emitting / receiving element 270SR can be formed in parallel with the formation of the light emitting element by simply adding a process for forming the active layer 273 to the manufacturing process of the light emitting element. Furthermore, the light emitting element and the light emitting / receiving element can be formed on the same substrate. Therefore, it is possible to provide the display unit with either or both of an imaging function and a sensing function without significantly increasing the manufacturing process.

[0278] There are no limitations on the stacking order of the light-emitting layer 283R and the active layer 273. Figures 11A and 11B show an example in which the active layer 273 is provided on the hole transport layer 282, and the light-emitting layer 283R is provided on the active layer 273. The stacking order of the light-emitting layer 283R and the active layer 273 may be reversed.

[0279] Furthermore, the light emitting / receiving element may not have at least one layer selected from the hole injection layer 281, the hole transport layer 282, the electron transport layer 284, and the electron injection layer 285. The light emitting / receiving element may also have other functional layers such as a hole blocking layer and an electron blocking layer.

[0280] In the light emitting / receiving element, a conductive film that transmits visible light is used for the electrode on the light extraction side, and a conductive film that reflects visible light is preferably used for the electrode on the non-light extraction side.

[0281] The functions and materials of the layers constituting the light emitting / receiving element are similar to those of the layers constituting the light emitting element and the light receiving element, and therefore detailed description thereof will be omitted.

[0282] 11C to 11G show examples of the layered structure of the light emitting and receiving element.

[0283] The light emitting / receiving element shown in FIG. 11C has a first electrode 277, a hole injection layer 281, a hole transport layer 282, a light emitting layer 283R, an active layer 273, an electron transport layer 284, an electron injection layer 285, and a second electrode 278.

[0284] FIG. 11C shows an example in which a light-emitting layer 283R is provided on a hole-transporting layer 282, and an active layer 273 is laminated on the light-emitting layer 283R.

[0285] As shown in FIGS. 11A to 11C, the active layer 273 and the light emitting layer 283R may be in contact with each other.

[0286] Furthermore, a buffer layer is preferably provided between the active layer 273 and the light-emitting layer 283R. In this case, the buffer layer preferably has hole transport properties and electron transport properties. For example, a bipolar substance is preferably used for the buffer layer. Alternatively, at least one layer selected from a hole injection layer, a hole transport layer, an electron transport layer, an electron injection layer, a hole blocking layer, and an electron blocking layer can be used as the buffer layer. FIG. 11D shows an example in which a hole transport layer 282 is used as the buffer layer.

[0287] By providing a buffer layer between the active layer 273 and the light-emitting layer 283R, it is possible to suppress the transfer of excitation energy from the light-emitting layer 283R to the active layer 273. In addition, the buffer layer can also be used to adjust the optical path length (cavity length) of the microcavity structure. Therefore, a light-emitting / receiving element having a buffer layer between the active layer 273 and the light-emitting layer 283R can obtain high light-emitting efficiency.

[0288] FIG. 11E shows an example of a laminated structure in which a hole transport layer 282-1, an active layer 273, a hole transport layer 282-2, and an emitting layer 283R are laminated in this order on a hole injection layer 281. The hole transport layer 282-2 functions as a buffer layer. The hole transport layer 282-1 and the hole transport layer 281-2 may contain the same material or different materials. Alternatively, a layer that can be used as the buffer layer described above may be used instead of the hole transport layer 281-2. Alternatively, the positions of the active layer 273 and the emitting layer 283R may be interchanged.

[0289] 11F differs from the light emitting / receiving element shown in Fig. 11A in that it does not have the hole transport layer 282. In this way, the light emitting / receiving element may not have at least one layer among the hole injection layer 281, the hole transport layer 282, the electron transport layer 284, and the electron injection layer 285. In addition, the light emitting / receiving element may have other functional layers such as a hole blocking layer or an electron blocking layer.

[0290] The light emitting / receiving device shown in FIG. 11G differs from the light emitting / receiving device shown in FIG. 11A in that it does not have active layer 273 and light emitting layer 283R, but has layer 289 that serves as both a light emitting layer and an active layer.

[0291] As a layer that serves as both a light-emitting layer and an active layer, for example, a layer containing three materials: an n-type semiconductor that can be used for the active layer 273, a p-type semiconductor that can be used for the active layer 273, and a light-emitting substance that can be used for the light-emitting layer 283R can be used.

[0292] It is preferable that the lowest energy absorption band in the absorption spectrum of the mixed material of n-type and p-type semiconductors does not overlap with the maximum peak in the emission spectrum (PL spectrum) of the luminescent substance, and it is more preferable that they are sufficiently separated from each other.

[0293] [Display device configuration example 2] A detailed structure of a display device according to one embodiment of the present invention will be described below, particularly an example of a display device including a light-receiving element and a light-emitting element.

[0294] [Configuration Example 2-1] 12A shows a cross-sectional view of the display device 300 A. The display device 300 A includes a substrate 351, a substrate 352, a light receiving element 310, and a light emitting element 390.

[0295] The light-emitting element 390 has a pixel electrode 391, a buffer layer 312, a light-emitting layer 393, a buffer layer 314, and a common electrode 315 stacked in this order. The buffer layer 312 can have one or both of a hole injection layer and a hole transport layer. The light-emitting layer 393 contains an organic compound. The buffer layer 314 can have one or both of an electron injection layer and an electron transport layer. The light-emitting element 390 has a function of emitting visible light 321. Note that the display device 300A may further have a light-emitting element that has a function of emitting infrared light.

[0296] The light receiving element 310 has a pixel electrode 311, a buffer layer 312, an active layer 313, a buffer layer 314, and a common electrode 315 stacked in this order. The active layer 313 contains an organic compound. The light receiving element 310 has a function of detecting visible light. The light receiving element 310 may also have a function of detecting infrared light.

[0297] The buffer layer 312, the buffer layer 314, and the common electrode 315 are layers common to the light-emitting element 390 and the light-receiving element 310, and are provided across these elements. The buffer layer 312, the buffer layer 314, and the common electrode 315 have portions that overlap with the active layer 313 and the pixel electrode 311, portions that overlap with the light-emitting layer 393 and the pixel electrode 391, and portions that do not overlap with either.

[0298] In the present embodiment, the pixel electrode functions as an anode and the common electrode 315 functions as a cathode in both the light-emitting element 390 and the light-receiving element 310. In other words, by driving the light-receiving element 310 by applying a reverse bias between the pixel electrode 311 and the common electrode 315, the display device 300A can detect light incident on the light-receiving element 310, generate charges, and extract them as a current.

[0299] The pixel electrode 311, the pixel electrode 391, the buffer layer 312, the active layer 313, the buffer layer 314, the light-emitting layer 393, and the common electrode 315 may each have a single-layer structure or a multilayer structure.

[0300] The pixel electrode 311 and the pixel electrode 391 are each located on an insulating layer 414. Each pixel electrode can be formed using the same material and in the same process. Ends of the pixel electrode 311 and the pixel electrode 391 are covered with a partition wall 416. Two adjacent pixel electrodes are electrically insulated (or electrically separated) from each other by the partition wall 416.

[0301] An organic insulating film is suitable for the partition 416. 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 416 is a layer that transmits visible light. Instead of the partition 416, a partition that blocks visible light may be provided.

[0302] The common electrode 315 is a layer that is used in common by the light receiving element 310 and the light emitting element 390 .

[0303] The materials and film thicknesses of the pair of electrodes of the light-receiving element 310 and the light-emitting element 390 can be made the same, which leads to a reduction in manufacturing cost and simplification of the manufacturing process of the display device.

[0304] The display device 300A includes a light receiving element 310, a light emitting element 390, a transistor 331, a transistor 332, and the like between a pair of substrates (substrate 351 and substrate 352).

[0305] In the light-receiving element 310, the buffer layer 312, active layer 313, and buffer layer 314 located between the pixel electrode 311 and the common electrode 315 can also be called organic layers (layers containing an organic compound). The pixel electrode 311 preferably has a function of reflecting visible light. The common electrode 315 has a function of transmitting visible light. Note that, when the light-receiving element 310 is configured to detect infrared light, the common electrode 315 has a function of transmitting infrared light. Furthermore, the pixel electrode 311 preferably has a function of reflecting infrared light.

[0306] The light receiving element 310 has a function of detecting light. Specifically, the light receiving element 310 is a photoelectric conversion element that receives light 322 incident from outside the display device 300A and converts the received light into an electrical signal. The light 322 can also be said to be light emitted by the light emitting element 390 and reflected by an object. The light 322 may also be incident on the light receiving element 310 via a lens or the like provided in the display device 300A.

[0307] In the light-emitting element 390, the buffer layer 312, the light-emitting layer 393, and the buffer layer 314 located between the pixel electrode 391 and the common electrode 315 can be collectively referred to as an EL layer. The EL layer has at least the light-emitting layer 393. As described above, the pixel electrode 391 preferably has a function of reflecting visible light. Furthermore, the common electrode 315 has a function of transmitting visible light. Note that, when the display device 300A has a configuration including a light-emitting element that emits infrared light, the common electrode 315 has a function of transmitting infrared light. Furthermore, the pixel electrode 391 preferably has a function of reflecting infrared light.

[0308] It is preferable that a micro-optical resonator (microcavity) structure is applied to the light-emitting element included in the display device of this embodiment. The light-emitting element 390 may have an optical adjustment layer between the pixel electrode 391 and the common electrode 315. By applying the micro-resonator structure, it is possible to intensify and extract light of a specific color from each light-emitting element.

[0309] The light-emitting element 390 has a function of emitting visible light. Specifically, the light-emitting element 390 is an electroluminescent element that emits light (here, visible light 321) toward the substrate 352 by applying a voltage between the pixel electrode 391 and the common electrode 315.

[0310] The pixel electrode 311 of the light-receiving element 310 is electrically connected to the source or drain of the transistor 331 through an opening provided in the insulating layer 414. The pixel electrode 391 of the light-emitting element 390 is electrically connected to the source or drain of the transistor 332 through an opening provided in the insulating layer 414.

[0311] The transistor 331 and the transistor 332 are in contact with each other on the same layer (substrate 351 in FIG. 12A).

[0312] At least a part of the circuit electrically connected to the light receiving element 310 is preferably formed using the same material and in the same process as the circuit electrically connected to the light emitting element 390. This allows the display device to be thinner and the manufacturing process to be simplified compared to when the two circuits are formed separately.

[0313] Preferably, the light receiving element 310 and the light emitting element 390 are each covered with a protective layer 395. In Fig. 12A, the protective layer 395 is provided on and in contact with the common electrode 315. Providing the protective layer 395 can prevent impurities such as water from entering the light receiving element 310 and the light emitting element 390, thereby improving the reliability of the light receiving element 310 and the light emitting element 390. In addition, the protective layer 395 and the substrate 352 are bonded together by an adhesive layer 342.

[0314] A light-shielding layer 358 is provided on the surface of the substrate 352 facing the substrate 351. The light-shielding layer 358 has openings at positions overlapping the light-emitting element 390 and the light-receiving element 310.

[0315] Here, the light receiving element 310 detects light emitted by the light emitting element 390 and reflected by the object. However, there is a case where the light emitted by the light emitting element 390 is reflected within the display device 300A and enters the light receiving element 310 without passing through the object. The light blocking layer 358 can suppress the influence of such stray light. For example, if the light blocking layer 358 is not provided, the light 323 emitted by the light emitting element 390 may be reflected by the substrate 352, and the reflected light 324 may enter the light receiving element 310. By providing the light blocking layer 358, it is possible to prevent the reflected light 324 from entering the light receiving element 310. This reduces noise and improves the sensitivity of the sensor using the light receiving element 310.

[0316] The light-shielding layer 358 can be made of a material that blocks light emitted from the light-emitting elements. The light-shielding layer 358 preferably absorbs visible light. For example, the light-shielding layer 358 can 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 358 may have a laminated structure of red, green, and blue color filters.

[0317] [Configuration Example 2-2] The display device 300B shown in FIG. 12B differs from the display device 300A described above mainly in that it includes a lens 349.

[0318] Lens 349 is provided on the substrate 351 side of substrate 352. Light 322 incident from the outside is incident on light receiving element 310 via lens 349. It is preferable that lens 349 and substrate 352 are made of a material that is highly transparent to visible light.

[0319] Light is incident on the light receiving element 310 via the lens 349, thereby narrowing the range of light incident on the light receiving element 310. This makes it possible to prevent the imaging ranges of the multiple light receiving elements 310 from overlapping, and to capture clear images with little blur.

[0320] Furthermore, the lens 349 can condense the incident light, thereby increasing the amount of light incident on the light receiving element 310. This increases the photoelectric conversion efficiency of the light receiving element 310.

[0321] [Configuration Example 2-3] A display device 300C shown in FIG. 12C differs from the display device 300A described above mainly in that the shape of the light-shielding layer 358 is different.

[0322] The light-shielding layer 358 is provided such that, in a plan view, the opening overlapping the light-receiving element 310 is located inside the light-receiving region of the light-receiving element 310. The smaller the diameter of the opening of the light-shielding layer 358 overlapping with the light-receiving element 310, the narrower the range of light incident on the light-receiving element 310 can be. This makes it possible to prevent the imaging ranges of the multiple light-receiving elements 310 from overlapping, allowing for the capture of clear images with little blur.

[0323] For example, the area of ​​the opening in the light-shielding layer 358 can be 80% or less, 70% or less, 60% or less, 50% or less, or 40% or less of the area of ​​the light-receiving region of the light-receiving element 310, and can be 1% or more, 5% or more, or 10% or more. The smaller the area of ​​the opening in the light-shielding layer 358, the clearer the image can be captured. On the other hand, if the area of ​​the opening is too small, the amount of light reaching the light-receiving element 310 may decrease, resulting in a decrease in light-receiving sensitivity. Therefore, it is preferable to set the area appropriately within the above-mentioned range. Note that the above-mentioned upper and lower limits can be combined arbitrarily. Furthermore, the light-receiving region of the light-receiving element 310 can be rephrased as the opening in the partition wall 416.

[0324] The center of the opening of the light-shielding layer 358 that overlaps with the light-receiving element 310 may be offset from the center of the light-receiving region of the light-receiving element 310 in a planar view. Furthermore, the opening of the light-shielding layer 358 may not overlap with the light-receiving region of the light-receiving element 310 in a planar view. This allows the light-receiving element 310 to receive only obliquely directed light that has passed through the opening of the light-shielding layer 358. This makes it possible to more effectively limit the range of light that enters the light-receiving element 310, thereby enabling a clear image to be captured.

[0325] [Configuration Example 2-4] The display device 300D shown in FIG. 13A differs from the display device 300A described above mainly in that the buffer layer 312 is not a common layer.

[0326] The light receiving element 310 has a pixel electrode 311, a buffer layer 312, an active layer 313, a buffer layer 314, and a common electrode 315. The light emitting element 390 has a pixel electrode 391, a buffer layer 392, a light emitting layer 393, a buffer layer 314, and a common electrode 315. The active layer 313, the buffer layer 312, the light emitting layer 393, and the buffer layer 392 each have an island-shaped top surface.

[0327] Buffer layer 312 and buffer layer 392 may comprise different materials or the same materials.

[0328] In this way, by forming separate buffer layers for the light-emitting element 390 and the light-receiving element 310, the degree of freedom in selecting materials for the buffer layers used for the light-emitting element 390 and the light-receiving element 310 is increased, making optimization easier. Furthermore, by using the buffer layer 314 and the common electrode 315 as a common layer, the manufacturing process is simplified and manufacturing costs can be reduced compared to when the light-emitting element 390 and the light-receiving element 310 are manufactured separately.

[0329] [Configuration Example 2-5] A display device 300E shown in FIG. 13B differs from the display device 300A described above mainly in that the buffer layer 314 is not a common layer.

[0330] The light-receiving element 310 has a pixel electrode 311, a buffer layer 312, an active layer 313, a buffer layer 314, and a common electrode 315. The light-emitting element 390 has a pixel electrode 391, a buffer layer 312, a light-emitting layer 393, a buffer layer 394, and a common electrode 315. The active layer 313, the buffer layer 314, the light-emitting layer 393, and the buffer layer 394 each have an island-shaped top surface.

[0331] Buffer layer 314 and buffer layer 394 may comprise different materials or the same materials.

[0332] In this way, by forming separate buffer layers for the light-emitting element 390 and the light-receiving element 310, the degree of freedom in selecting the materials for the buffer layers used for the light-emitting element 390 and the light-receiving element 310 is increased, making optimization easier. Furthermore, by using the buffer layer 312 and the common electrode 315 as a common layer, the manufacturing process is simplified and manufacturing costs can be reduced compared to when the light-emitting element 390 and the light-receiving element 310 are manufactured separately.

[0333] [Configuration Example 2-6] A display device 300F shown in FIG. 13C differs from the display device 300A described above mainly in that the buffer layer 312 and the buffer layer 314 are not a common layer.

[0334] The light-receiving element 310 has a pixel electrode 311, a buffer layer 312, an active layer 313, a buffer layer 314, and a common electrode 315. The light-emitting element 390 has a pixel electrode 391, a buffer layer 392, a light-emitting layer 393, a buffer layer 394, and a common electrode 315. The buffer layer 312, the active layer 313, the buffer layer 314, the buffer layer 392, the light-emitting layer 393, and the buffer layer 394 each have an island-shaped top surface.

[0335] In this way, by forming separate buffer layers for the light-emitting element 390 and the light-receiving element 310, the degree of freedom in selecting materials for the buffer layers used for the light-emitting element 390 and the light-receiving element 310 is increased, making optimization easier. Furthermore, by using the common electrode 315 as a common layer, the manufacturing process is simplified and manufacturing costs can be reduced compared to when the light-emitting element 390 and the light-receiving element 310 are manufactured separately.

[0336] [Display device configuration example 3] A detailed structure of a display device according to one embodiment of the present invention will be described below, particularly an example of a display device including a light-emitting and light-emitting element.

[0337] In the following, the same parts as those described above will be referred to and explanations thereof may be omitted.

[0338] [Configuration Example 3-1] 14A shows a cross-sectional view of a display device 300G. The display device 300G has a light emitting / receiving element 390SR, a light emitting element 390G, and a light emitting element 390B.

[0339] The light emitting / receiving element 390SR functions as a light emitting element that emits red light 321R and as a photoelectric conversion element that receives light 322. The light emitting element 390G can emit green light 321G. The light emitting element 390B can emit blue light 321B.

[0340] The light emitting / receiving element 390SR has a pixel electrode 311, a buffer layer 312, an active layer 313, a light emitting layer 393R, a buffer layer 314, and a common electrode 315. The light emitting element 390G has a pixel electrode 391G, a buffer layer 312, a light emitting layer 393G, a buffer layer 314, and a common electrode 315. The light emitting element 390B has a pixel electrode 391B, a buffer layer 312, a light emitting layer 393B, a buffer layer 314, and a common electrode 315.

[0341] The buffer layer 312, the buffer layer 314, and the common electrode 315 are layers (common layers) common to the light emitting / receiving element 390SR, the light emitting element 390G, and the light emitting element 390B, and are provided across these elements. The active layer 313, the light emitting layer 393R, the light emitting layer 393G, and the light emitting layer 393B each have an island-shaped upper surface. Note that, in FIG. 14, the stack of the active layer 313 and the light emitting layer 393R, the light emitting layer 393G, and the light emitting layer 393B are shown as being spaced apart from each other, but they may also have areas where adjacent two layers overlap.

[0342] As with the display device 300D, the display device 300E, or the display device 300F, one or both of the buffer layer 312 and the buffer layer 314 may not be used as a common layer.

[0343] The pixel electrode 311 is electrically connected to one of the source and drain of the transistor 331. The pixel electrode 391G is electrically connected to one of the source and drain of the transistor 332G. The pixel electrode 391B is electrically connected to one of the source and drain of the transistor 332B.

[0344] With this configuration, a display device with higher resolution can be realized.

[0345] [Configuration Example 3-2] A display device 300H shown in FIG. 14B differs from the display device 300G described above mainly in that the configuration of the light emitting / receiving element 390SR is different.

[0346] The light emitting / receiving element 390SR has a light emitting / receiving layer 318R in place of the active layer 313 and the light emitting layer 393R.

[0347] The light emitting / receiving layer 318R functions both as a light emitting layer and an active layer. For example, a layer containing the above-mentioned light emitting material, an n-type semiconductor, and a p-type semiconductor can be used.

[0348] By adopting such a structure, the manufacturing process can be further simplified, which facilitates cost reduction.

[0349] [Display device configuration example 4] A more specific structure of the display device of one embodiment of the present invention will be described below.

[0350] FIG. 15 shows a perspective view of display device 400, and FIG. 16A shows a cross-sectional view of display device 400.

[0351] The display device 400 has a configuration in which a substrate 353 and a substrate 354 are bonded together. In Fig. 15, the substrate 354 is clearly indicated by a dashed line.

[0352] The display device 400 includes a display unit 362, a circuit 364, wiring 365, etc. Fig. 15 shows an example in which an IC (integrated circuit) 373 and an FPC 372 are mounted on the display device 400. Therefore, the configuration shown in Fig. 15 can also be said to be a display module including the display device 400, an IC, and an FPC.

[0353] The circuit 364 can be, for example, a scanning line driver circuit.

[0354] The wiring 365 has a function of supplying signals and power to the display unit 362 and the circuit 364. The signals and power are input to the wiring 365 from the outside via the FPC 372 or input to the wiring 365 from the IC 373.

[0355] 15 shows an example in which an IC 373 is provided on a substrate 353 by a COG (Chip On Glass) method or a COF (Chip On Film) method. The IC 373 may be, for example, an IC having a scanning line driver circuit or a signal line driver circuit. The display device 400 and the display module may not include an IC. Alternatively, the IC may be mounted on an FPC by a COF method or the like.

[0356] Figure 16A shows an example of a cross section of the display device 400 shown in Figure 15, with a portion of the area including the FPC 372, a portion of the area including the circuit 364, a portion of the area including the display unit 362, and a portion of the area including the end portion cut away.

[0357] A display device 400 shown in FIG. 16 includes a transistor 408, a transistor 409, a transistor 410, a light-emitting element 390, a light-receiving element 310, and the like between a substrate 353 and a substrate 354.

[0358] The substrate 354 and the protective layer 395 are bonded together via an adhesive layer 342, and a solid sealing structure is applied to the display device 400.

[0359] The substrate 353 and the insulating layer 412 are bonded together by an adhesive layer 355 .

[0360] The display device 400 is manufactured by first bonding a fabrication substrate provided with an insulating layer 412, each transistor, the light-receiving element 310, the light-emitting element 390, and the like to a substrate 354 provided with a light-shielding layer 358 and the like with an adhesive layer 342. Then, the fabrication substrate is peeled off, and a substrate 353 is bonded to the exposed surface using an adhesive layer 355, thereby transferring each component formed on the fabrication substrate to the substrate 353. The substrate 353 and the substrate 354 are preferably flexible. This can increase the flexibility of the display device 400.

[0361] The light-emitting element 390 has a layered structure in which a pixel electrode 391, a buffer layer 312, a light-emitting layer 393, a buffer layer 314, and a common electrode 315 are stacked in this order from the insulating layer 414 side. The pixel electrode 391 is connected to one of the source and the drain of the transistor 408 through an opening provided in the insulating layer 414. The transistor 408 has a function of controlling current flowing in the light-emitting element 390.

[0362] The light-receiving element 310 has a layered structure in which a pixel electrode 311, a buffer layer 312, an active layer 313, a buffer layer 314, and a common electrode 315 are stacked in this order from the insulating layer 414 side. The pixel electrode 311 is connected to one of the source and drain of the transistor 409 through an opening provided in the insulating layer 414. The transistor 409 has a function of controlling transfer of charges accumulated in the light-receiving element 310.

[0363] Light emitted by light emitting element 390 is emitted toward substrate 354. Light is incident on light receiving element 310 via substrate 354 and adhesive layer 342. It is preferable that substrate 354 be made of a material that is highly transparent to visible light.

[0364] The pixel electrode 311 and the pixel electrode 391 can be manufactured using the same material and in the same process. The buffer layer 312, the buffer layer 314, and the common electrode 315 are used in common for the light receiving element 310 and the light emitting element 390. The light receiving element 310 and the light emitting element 390 can have the same configuration except for the configurations of the active layer 313 and the light emitting layer 393. This allows the light receiving element 310 to be built into the display device 400 without significantly increasing the number of manufacturing processes.

[0365] A light-shielding layer 358 is provided on the surface of substrate 354 facing substrate 353. Light-shielding layer 358 has openings at positions overlapping with light-emitting element 390 and light-receiving element 310. By providing light-shielding layer 358, the range in which light is detected by light-receiving element 310 can be controlled. As described above, it is preferable to control the light incident on light-receiving element 310 by adjusting the position and area of ​​the opening in the light-shielding layer provided at a position overlapping with light-receiving element 310. Furthermore, by providing light-shielding layer 358, it is possible to prevent light from being directly incident on light-receiving element 310 from light-emitting element 390 without passing through an object. Therefore, a sensor with low noise and high sensitivity can be realized.

[0366] The edges of the pixel electrode 311 and the pixel electrode 391 are covered with a partition wall 416. The pixel electrode 311 and the pixel electrode 391 contain a material that reflects visible light, and the common electrode 315 contains a material that transmits visible light.

[0367] 16A shows an example in which there is a region where part of the active layer 313 overlaps part of the light emitting layer 393. The overlapping portion of the active layer 313 and the light emitting layer 393 preferably overlaps with the light blocking layer 358 and the partition wall 416.

[0368] The transistor 408, the transistor 409, and the transistor 410 are all formed over a substrate 353. These transistors can be manufactured using the same material and the same process.

[0369] An insulating layer 412, an insulating layer 411, an insulating layer 425, an insulating layer 415, an insulating layer 418, and an insulating layer 414 are provided over a substrate 353 with an adhesive layer 355 interposed therebetween. Parts of the insulating layer 411 and the insulating layer 425 each function as a gate insulating layer of each transistor. The insulating layer 415 and the insulating layer 418 are provided to cover the transistor. The insulating layer 414 is provided to cover the transistor and functions as a planarization layer. Note that the number of gate insulating layers and the number of insulating layers covering the transistors are not limited, and each may be a single layer or two or more layers.

[0370] It is preferable that at least one insulating layer covering the transistor is made of a material that is resistant to the diffusion of impurities such as water and hydrogen. This allows the insulating layer to function as a barrier layer. With this structure, it is possible to effectively prevent impurities from diffusing into the transistor from the outside, thereby improving the reliability of the display device.

[0371] The insulating layer 411, the insulating layer 412, the insulating layer 425, the insulating layer 415, and the insulating layer 418 are preferably formed using an inorganic insulating film. Examples of the inorganic insulating film that can be used include a silicon nitride film, a silicon oxynitride film, a silicon oxide film, a silicon nitride oxide film, an aluminum oxide film, and an aluminum nitride film. 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, and a neodymium oxide film may also be used. Two or more of the above insulating films may be stacked.

[0372] Here, organic insulating films often have lower barrier properties than inorganic insulating films. Therefore, it is preferable that the organic insulating film has an opening near the edge of the display device 400. In region 428 shown in FIG. 16, an opening is formed in the insulating layer 414. This makes it possible to prevent impurities from entering from the edge of the display device 400 via the organic insulating film. Alternatively, the organic insulating film may be formed so that the edge of the organic insulating film is located inside the edge of the display device 400, so that the organic insulating film is not exposed at the edge of the display device 400.

[0373] In a region 428 near the edge of the display device 400, the insulating layer 418 and the protective layer 395 preferably contact each other through the opening in the insulating layer 414. In particular, it is preferable that the inorganic insulating film of the insulating layer 418 and the inorganic insulating film of the protective layer 395 contact each other. This makes it possible to prevent impurities from entering the display unit 362 from the outside through the organic insulating film. Therefore, the reliability of the display device 400 can be improved.

[0374] An organic insulating film is suitable for the insulating layer 414, which 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.

[0375] By providing the protective layer 395 that covers the light emitting element 390 and the light receiving element 310, it is possible to prevent impurities such as water from entering the light emitting element 390 and the light receiving element 310, thereby improving their reliability.

[0376] The protective layer 395 may have a single layer or a laminated structure. For example, the protective layer 395 may have a laminated structure of an organic insulating film and an inorganic insulating film. In this case, it is preferable that the end of the inorganic insulating film extends further outward than the end of the organic insulating film.

[0377] FIG. 16B is a cross-sectional view of a transistor 401a that can be used for the transistor 408, the transistor 409, and the transistor 410.

[0378] The transistor 401a is provided over an insulating layer 412 (not shown) and includes a conductive layer 421 functioning as a first gate, an insulating layer 411 functioning as a first gate insulating layer, a semiconductor layer 431, an insulating layer 425 functioning as a second gate insulating layer, and a conductive layer 423 functioning as a second gate. The insulating layer 411 is located between the conductive layer 421 and the semiconductor layer 431. The insulating layer 425 is located between the conductive layer 423 and the semiconductor layer 431.

[0379] The semiconductor layer 431 has a region 431i and a pair of regions 431n. The region 431i functions as a channel formation region. One of the pair of regions 431n functions as a source and the other functions as a drain. The region 431n has a higher carrier concentration and higher conductivity than the region 431i. The conductive layer 422a and the conductive layer 422b are connected to the region 431n through openings provided in the insulating layer 418 and the insulating layer 415, respectively.

[0380] 16C is a cross-sectional view of a transistor 401b that can be used for the transistor 408, the transistor 409, and the transistor 410. FIG. 16C also shows an example in which the insulating layer 415 is not provided. In the transistor 401b, the insulating layer 425 is processed in a manner similar to that of the conductive layer 423, and the insulating layer 418 and the region 431n are in contact with each other.

[0381] Note that the structure of the transistor included in the display device of this embodiment is not particularly limited. For example, a planar transistor, a staggered transistor, an inverted staggered transistor, or the like can be used. Furthermore, either a top-gate transistor or a bottom-gate transistor structure may be used. Alternatively, gates may be provided above and below a semiconductor layer in which a channel is formed.

[0382] The transistors 408, 409, and 410 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 transistors. Alternatively, the threshold voltage of the transistor may be controlled by applying a potential for controlling the threshold voltage to one of the two gates and a potential for driving to the other.

[0383] The crystallinity of a semiconductor material used for a transistor is not particularly limited, and any of an amorphous semiconductor, a single crystal semiconductor, and a crystalline semiconductor (a microcrystalline semiconductor, a polycrystalline semiconductor, or a semiconductor having a crystalline region in part) may be used. The use of a crystalline semiconductor is preferable because it can suppress deterioration of transistor characteristics.

[0384] 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).

[0385] The semiconductor layer preferably contains, for example, indium, M (wherein M is one or more elements selected from gallium, aluminum, silicon, boron, yttrium, tin, copper, vanadium, beryllium, titanium, iron, nickel, germanium, zirconium, molybdenum, lanthanum, cerium, neodymium, hafnium, tantalum, tungsten, and magnesium), and zinc. In particular, M is preferably one or more elements selected from aluminum, gallium, yttrium, and tin.

[0386] 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.

[0387] 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 compositions in which In:M:Zn=1:1:1 or thereabouts, In:M:Zn=1:1:1.2 or thereabouts, In:M:Zn=2:1:3 or thereabouts, In:M:Zn=3:1:2 or thereabouts, In:M:Zn=4:2:3 or thereabouts, In:M:Zn=4:2:4.1 or thereabouts, In:M:Zn=5:1:3 or thereabouts, In:M:Zn=5:1:6 or thereabouts, In:M:Zn=5:1:7 or thereabouts, In:M:Zn=5:1:8 or thereabouts, In:M:Zn=6:1:6 or thereabouts, and In:M:Zn=5:2:5 or thereabouts, etc. Note that "nearby compositions" includes a range of ±30% of the desired atomic ratio.

[0388] For example, when describing a composition with an atomic ratio of In:Ga:Zn=4:2:3 or thereabout, this includes a case where, when the atomic ratio of In is 4, the atomic ratio of Ga is 1 to 3 and the atomic ratio of Zn is 2 to 4. Furthermore, when describing a composition with an atomic ratio of In:Ga:Zn=5:1:6 or thereabout, this includes a case where, when the atomic ratio of In is 5, the atomic ratio of Ga is greater than 0.1 and less than 2 and the atomic ratio of 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, this includes a case where, when the atomic ratio of In is 1, the atomic ratio of Ga is greater than 0.1 and less than 2 and the atomic ratio of Zn is greater than 0.1 and less than 2.

[0389] The transistor 410 included in the circuit 364 may have the same structure as the transistors 408 and 409 included in the display portion 362 or may have different structures. The transistors included in the circuit 364 may all have the same structure or may have two or more types of structures. Similarly, the transistors included in the display portion 362 may all have the same structure or may have two or more types of structures.

[0390] A connection portion 404 is provided in an area of ​​the substrate 353 where the substrate 354 does not overlap. In the connection portion 404, the wiring 365 is electrically connected to the FPC 372 via a conductive layer 366 and a connection layer 442. The conductive layer 366, which is obtained by processing the same conductive film as the pixel electrodes 311 and 391, is exposed on the upper surface of the connection portion 404. This allows the connection portion 404 and the FPC 372 to be electrically connected via the connection layer 442.

[0391] Various optical members can be disposed on the outside of substrate 354. 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 scratches caused by use, an impact absorbing layer, etc. may be disposed on the outside of substrate 354.

[0392] The flexibility of the display device can be increased by using a flexible material for the substrate 353 and the substrate 354. Furthermore, without being limited thereto, the substrate 353 and the substrate 354 can be made of glass, quartz, ceramic, sapphire, resin, or the like.

[0393] The adhesive layer can be made of various curable adhesives, such as photo-curable adhesives (e.g., ultraviolet curable), reactive curable adhesives, thermosetting adhesives, and anaerobic adhesives. 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. Materials with low moisture permeability, such as epoxy resin, are particularly preferred. Two-component resins may also be used. Adhesive sheets, etc., may also be used.

[0394] The connection layer may be made of an anisotropic conductive film (ACF), an anisotropic conductive paste (ACP), or the like.

[0395] Materials that can be used for conductive layers such as the gate, source, and drain of a transistor, as well as various wirings and electrodes that constitute a display device include metals such as aluminum, titanium, chromium, nickel, copper, yttrium, zirconium, molybdenum, silver, tantalum, and tungsten, and alloys containing these metals as main components, etc. Films containing these materials can be used as a single layer or a stacked layer structure.

[0396] Examples of light-transmitting conductive materials include conductive oxides such as indium oxide, indium tin oxide, indium zinc oxide, zinc oxide, and zinc oxide containing gallium, or graphene. Alternatively, metal materials such as gold, silver, platinum, magnesium, nickel, tungsten, chromium, molybdenum, iron, cobalt, copper, palladium, and titanium, or alloy materials containing such metal materials, can be used. Alternatively, nitrides of such metal materials (e.g., titanium nitride) can be used. When using metal materials or alloy materials (or their nitrides), it is preferable to thin them sufficiently to ensure light-transmitting properties. A stacked film of the above materials can also be used as the conductive layer. For example, a stacked film of an alloy of silver and magnesium and indium tin oxide is preferable because it can enhance conductivity. These can also be used for conductive layers such as various wirings and electrodes constituting a display device, conductive layers (conductive layers functioning as pixel electrodes or common electrodes) of light-emitting elements and light-receiving elements (or light-emitting / receiving elements), and the like.

[0397] 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.

[0398] This embodiment mode can be implemented by appropriately combining at least a part thereof with other embodiment modes described in this specification.

[0399] (Embodiment 3) In this embodiment, a circuit that can be used in a display device of one embodiment of the present invention will be described.

[0400] FIG. 17A is a block diagram of a pixel of a display device of one embodiment of the present invention.

[0401] The pixel includes an OLED, an OPD (organic photo diode), a sensor circuit (referred to as a sensing circuit), a driving transistor (referred to as a driving transistor), and a selection transistor (referred to as a switching transistor).

[0402] Light emitted from the OLED is reflected by an object (hereinafter referred to as "Object"), and the reflected light is received by the OPD, thereby capturing an image of the object. One embodiment of the present invention can function as a touch sensor, an image sensor, an image scanner, etc. One embodiment of the present invention can be applied to biometric authentication by capturing an image of a fingerprint, palm print, blood vessels (veins, etc.), etc. It can also capture an image of a printed matter with photographs, text, etc., or the surface of an object, and acquire the image information.

[0403] The drive transistor and selection transistor constitute a drive circuit for driving the OLED. The drive transistor has the function of controlling the current flowing through the OLED, allowing the OLED to emit light at a brightness corresponding to that current. The selection transistor has the function of controlling the selection and non-selection of pixels. The value (e.g., voltage value) of video data (referred to as Video Data) input from outside via the selection transistor controls the magnitude of the current flowing through the drive transistor and OLED, allowing the OLED to emit light at the desired brightness.

[0404] The sensor circuit corresponds to a drive circuit for controlling the operation of the OPD, and can control operations such as a reset operation that resets the potential of the OPD electrodes, an exposure operation that accumulates charge in the OPD according to the amount of light irradiated, a transfer operation that transfers the charge accumulated in the OPD to a node in the sensor circuit, and a readout operation that outputs a signal (e.g., voltage or current) according to the magnitude of the charge to an external readout circuit as sensing data (referred to as "Sensing Data").

[0405] The pixel shown in FIG. 17B differs from the above mainly in that it has a memory section connected to the drive transistor.

[0406] Weight data is provided to the memory unit. Data obtained by adding together the video data input via the selection transistor and the weight data stored in the memory unit is provided to the drive transistor. The weight data stored in the memory unit can change the brightness of the OLED from the brightness when only video data is provided. Specifically, it is possible to increase or decrease the brightness of the OLED. For example, increasing the brightness of the OLED can increase the light receiving sensitivity of the sensor.

[0407] FIG. 17C shows an example of a pixel circuit that can be used in the sensor circuit.

[0408] 17C includes a light receiving element PD, a transistor M1, a transistor M2, a transistor M3, a transistor M4, and a capacitor C1. Here, an example is shown in which a photodiode is used as the light receiving element PD.

[0409] The cathode of the light-receiving element PD is electrically connected to the wiring V1, and the anode is electrically connected to one of the source and drain of the transistor M1. The gate of the transistor M1 is electrically connected to the wiring TX, and the other of the source and drain is electrically connected to one electrode of the capacitor C1, one of the source and drain of the transistor M2, and the gate of the transistor M3. The gate of the transistor M2 is electrically connected to the wiring RES, and the other of the source and drain is electrically connected to the wiring V2. The source and drain of the transistor M3 is electrically connected to the wiring V3, and the other of the source and drain is electrically connected to one of the source and drain of the transistor M4. The gate of the transistor M4 is electrically connected to the wiring SE, and the other of the source and drain is electrically connected to the wiring OUT1.

[0410] A constant potential is supplied to the wiring V1, wiring V2, and wiring V3. When the light-receiving element PD is driven with a reverse bias, a potential lower than the potential of the wiring V1 is supplied to the wiring V2. The transistor M2 is controlled by a signal supplied to the wiring RES and has the function of resetting the potential of the node connected to the gate of the transistor M3 to the potential supplied to the wiring V2. The transistor M1 is controlled by a signal supplied to the wiring TX and has the function of controlling the timing of transferring the charge accumulated in the light-receiving element PD to the node. The transistor M3 functions as an amplifying transistor that outputs according to the potential of the node. The transistor M4 is controlled by a signal supplied to the wiring SE and functions as a selection transistor that reads out the output according to the potential of the node to an external circuit connected to the wiring OUT1.

[0411] Here, the light receiving element PD corresponds to the OPD, and the potential or current output from the wiring OUT1 corresponds to the sensing data.

[0412] FIG. 17D shows an example of a pixel circuit for driving the above OLED.

[0413] 17D includes a light-emitting element EL, transistors M5, M6, and M7, and a capacitor C2. Here, an example is shown in which a light-emitting diode is used as the light-emitting element EL. In particular, it is preferable to use an organic EL element as the light-emitting element EL.

[0414] The light-emitting element EL corresponds to the OLED, the transistor M5 corresponds to the selection transistor, the transistor M6 corresponds to the drive transistor, and the wiring VS corresponds to the wiring to which the video data is input.

[0415] The transistor M5 has a gate electrically connected to the wiring VG, one of its source and drain electrically connected to the wiring VS, and the other of its source and drain electrically connected to one electrode of the capacitor C2 and the gate of the transistor M6. One of the source and drain of the transistor M6 is electrically connected to the wiring V4, and the other is electrically connected to the anode of the light-emitting element EL and one of the source and drain of the transistor M7. The transistor M7 has a gate electrically connected to the wiring MS, and the other of its source and drain electrically connected to the wiring OUT2. The cathode of the light-emitting element EL is electrically connected to the wiring V5.

[0416] A constant potential is supplied to the wiring V4 and the wiring V5. The anode side of the light-emitting element EL can be set to a high potential, and the cathode side can be set to a lower potential than the anode side. The transistor M5 is controlled by a signal supplied to the wiring VG and functions as a selection transistor for controlling the selection state of the pixel circuit PIX2. The transistor M6 also functions as a drive transistor for controlling the current flowing through the light-emitting element EL according to the potential supplied to its gate. When the transistor M5 is in a conductive state, the potential supplied to the wiring VS is supplied to the gate of the transistor M6, and the light emission brightness of the light-emitting element EL can be controlled according to the potential. The transistor M7 is controlled by a signal supplied to the wiring MS and has one or both of the following functions: setting the potential between the transistor M6 and the light-emitting element EL to the potential supplied to the wiring OUT2, and outputting the potential between the transistor M6 and the light-emitting element EL to the outside via the wiring OUT2.

[0417] FIG. 17E shows an example of a pixel circuit including a memory unit that can be applied to the configuration shown in FIG. 17B.

[0418] 17E has a configuration in which a transistor M8 and a capacitor C3 are added to the pixel circuit PIX2. In addition, in the pixel circuit PIX3, the line VS in the pixel circuit PIX2 is changed to a line VS1, and the line VG is changed to a line VG1.

[0419] The transistor M8 has a gate electrically connected to the wiring VG2, one of a source and a drain electrically connected to the wiring VS2, and the other electrically connected to one electrode of the capacitor C3. The other electrode of the capacitor C3 is electrically connected to the gate of the transistor M6, one electrode of the capacitor C2, and the other of the source and drain of the transistor M5.

[0420] The wiring VS1 corresponds to the wiring to which the video data is supplied. The wiring VS2 corresponds to the wiring to which the weight data is supplied. The node to which the gate of the transistor M6 is connected corresponds to the memory unit.

[0421] An example of the operation method of the pixel circuit PIX3 will be described. First, a first potential is written from the wiring VS1 to a node connected to the gate of the transistor M6 via the transistor M5. Then, the transistor M5 is turned off, bringing the node into a floating state. Next, a second potential is written from the wiring VS2 to one electrode of the capacitor C3 via the transistor M8. As a result, the potential of the node changes from the first potential to a third potential in response to the second potential due to capacitive coupling of the capacitor C3. Then, a current corresponding to the third potential flows through the transistor M6 and the light-emitting element EL, causing the light-emitting element EL to emit light at a luminance corresponding to the third potential.

[0422] In the display device of this embodiment, an image may be displayed by causing the light-emitting element to emit light in a pulsed manner. By shortening the driving time of the light-emitting element, it is possible to reduce the power consumption of the display panel and suppress heat generation. In particular, organic EL elements are suitable because of their excellent frequency characteristics. The frequency can be, for example, 1 kHz or more and 100 MHz or less. Also, a driving method (also called duty driving) in which light is emitted by changing the pulse width may be used.

[0423] Here, it is preferable to use transistors that use a metal oxide (oxide semiconductor) in the semiconductor layer in which the channel is formed for the transistors M1, M2, M3, and M4 of the pixel circuit PIX1, the transistors M5, M6, and M7 of the pixel circuit PIX2, and the transistor M8 of the pixel circuit PIX3.

[0424] Alternatively, the transistors M1 to M8 may be transistors in which silicon is used as a semiconductor in which a channel is formed. In particular, using silicon with high crystallinity, such as single crystal silicon or polycrystalline silicon, is preferable because high field-effect mobility can be achieved and higher-speed operation can be achieved.

[0425] Alternatively, a structure may be used in which at least one of the transistors M1 to M8 includes an oxide semiconductor and the remaining transistors include silicon.

[0426] For example, transistors including an oxide semiconductor and having extremely low off-state current are preferably used as the transistors M1, M2, M5, M7, and M8, which function as switches for retaining charge. In this case, a transistor including silicon may be used as one or more of the other transistors.

[0427] Although the transistors in the pixel circuits PIX1, PIX2, and PIX3 are represented as n-channel transistors, p-channel transistors may also be used, or a configuration in which n-channel transistors and p-channel transistors are mixed may be used.

[0428] This embodiment mode can be implemented by appropriately combining at least a part thereof with other embodiment modes described in this specification.

[0429] (Fourth embodiment) In this embodiment, a configuration example of a stacked panel, which is one mode of a display panel that can be easily enlarged, and its application example will be described with reference to the drawings.

[0430] One embodiment of the present invention is a display panel that can be enlarged by arranging multiple display panels so that they partially overlap. Of the two overlapping display panels, at least the display panel located on the display surface side (upper side) has a portion that is adjacent to the display section and transmits visible light. Pixels of the lower display panel and the portion of the upper display panel that transmits visible light are arranged to overlap. This allows images displayed on the two display panels to be displayed continuously and seamlessly when viewed from the display surface side (in a plan view).

[0431] For example, one embodiment of the present invention is a stacked panel including a first display panel and a second display panel. The first display panel has a first region, which includes a first pixel and a second pixel. The second display panel has a second region, a third region, and a fourth region. The second region includes a third pixel, and the third region has a function of transmitting visible light, and the fourth region has a function of blocking visible light. The second pixel of the first display panel and the third region of the second display panel overlap each other. The aperture ratio of the second pixel is preferably larger than that of the first pixel.

[0432] The display device including the light-emitting element and the light-receiving element exemplified above can be used for one or both of the first display panel and the second display panel. In other words, it can be said that at least one of the first pixel, the second pixel, and the third pixel has a light-emitting element and a light-receiving element.

[0433] More specifically, for example, the following configuration can be adopted.

[0434] [Configuration example 1] [Display panel] FIG. 18A is a schematic top view of a display panel 500 included in a display device according to one embodiment of the present invention.

[0435] The display panel 500 includes a display area 501, an area 510 that transmits visible light, and an area 520 that has a portion that blocks visible light, both adjacent to the display area 501. Fig. 18A shows an example in which an FPC (Flexible Printed Circuit) 512 is provided on the display panel 500.

[0436] Here, even when the display panel 500 is a standalone unit, it is possible to display an image in the display area 501. Furthermore, even when the display panel 500 is a standalone unit, it is possible to capture an image using the display area 501.

[0437] The region 510 may be provided with, for example, a pair of substrates constituting the display panel 500 and a sealant for sealing a display element sandwiched between the pair of substrates. In this case, a material that is translucent to visible light is used for the members provided in the region 510.

[0438] The region 520 is provided with wirings electrically connected to pixels included in the display region 501, for example. In addition to such wirings, a driver circuit (scanning line driver circuit, signal line driver circuit, etc.) for driving the pixels, a circuit such as a protection circuit, etc. may also be provided. The region 520 also includes a region provided with terminals (also referred to as connection terminals) electrically connected to the FPC 512 and wirings electrically connected to the terminals.

[0439] For detailed explanation of an example of the cross-sectional configuration of the display panel, the first and second embodiments can be cited.

[0440] [Laminated panel] A stacked panel 550 according to one embodiment of the present invention includes a plurality of the above-described display panels 500. Figure 18B shows a schematic top view of a stacked panel 550 including three display panels.

[0441] In the following description, when distinguishing between display panels, components included in display panels, or components related to display panels, letters will be added after their reference numerals. Unless otherwise specified, the letter "a" will be added to the display panel and its components that are located at the bottom (opposite the display surface) of multiple display panels that are partially overlapped with each other, and letters will be added in alphabetical order after the reference numerals of one or more display panels and their components that are located above it. Unless otherwise specified, even when describing a configuration including multiple display panels, the letters will be omitted when describing matters common to each display panel or component.

[0442] The stacked panel 550 shown in FIG. 18B includes a display panel 500a, a display panel 500b, and a display panel 500c.

[0443] Display panel 500b is disposed so that a portion thereof overlaps the upper side (display surface side) of display panel 500a. Specifically, display region 501a of display panel 500a and region 510b of display panel 500b that transmits visible light overlap, and display region 501a of display panel 500a and region 520b of display panel 500b that shields visible light do not overlap.

[0444] Furthermore, display panel 500c is disposed such that a portion thereof overlaps the upper side (display surface side) of display panel 500b. Specifically, display region 501b of display panel 500b and region 510c of display panel 500c that transmits visible light overlap, and display region 501b of display panel 500b and region 520c of display panel 500c that shields visible light do not overlap.

[0445] Since region 510b, which transmits visible light, is superimposed on display region 501a, the entire display region 501a can be viewed from the display surface side. Similarly, since region 510c is superimposed on display region 501b, the entire display region 501b can be viewed from the display surface side. Therefore, the region in which display region 501a, display region 501b, and display region 501c are seamlessly arranged can be used as display region 551 of stacked panel 550.

[0446] The stacked panel 550 can expand the display area 551 by the number of display panels 500. In this case, by using display panels with an imaging function (i.e., display panels having pixels each having a light-emitting element and a light-receiving element) for all the display panels 500, the entire display area 551 can be used as an imaging area.

[0447] However, without being limited to this, a display panel having an imaging function and a display panel not having an imaging function (for example, not having a light receiving element) may be combined. For example, a display panel having an imaging function may be applied only to a necessary portion, and a display panel not having an imaging function may be applied to other portions.

[0448] [Configuration example 2] Although FIG. 18B shows a configuration in which a plurality of display panels 500 are arranged overlapping in one direction, a plurality of display panels 500 may be arranged overlapping in two directions, that is, the vertical direction and the horizontal direction.

[0449] Fig. 19A shows an example of a display panel 500 having a different shape of region 510 from that of Fig. 18A. In the display panel 500 shown in Fig. 19A, regions 510 that transmit visible light are arranged along two sides of a display region 501.

[0450] Fig. 19B shows a schematic perspective view of a stacked panel 550 in which two display panels 500 shown in Fig. 19A are arranged vertically and two horizontally. Fig. 19C is a schematic perspective view of stacked panel 550 as seen from the opposite side to the display surface side.

[0451] 19B and 19C, a region along the short side of display region 501a of display panel 500a overlaps with a portion of region 510b of display panel 500b. A region along the long side of display region 501a of display panel 500a overlaps with a portion of region 510c of display panel 500c. Region 510d of display panel 500d overlaps with a region along the long side of display region 501b of display panel 500b and a region along the short side of display region 501c of display panel 500c.

[0452] Therefore, as shown in FIG. 19B, a region in which display region 501a, display region 501b, display region 501c, and display region 501d are seamlessly arranged can be used as display region 551 of stacked panel 550.

[0453] Here, it is preferable that the pair of substrates used in the display panel 500 be made of a flexible material, thereby making the display panel 500 flexible. This allows, for example, as shown in FIGS. 19B and 19C , when an FPC 512a or the like is provided on the display surface side, a portion of the display panel 500a on the side where the FPC 512a is provided to be curved, and the FPC 512a can be arranged to overlap the underside of the display region 501b of the adjacent display panel 500b. As a result, the FPC 512a can be arranged without physically interfering with the rear surface of the display panel 500b. Furthermore, since the thickness of the FPC 512a does not need to be considered when overlapping and bonding the display panels 500a and 500b, the difference in height between the upper surface of the region 510b of the display panel 500b and the upper surface of the display region 501a of the display panel 500a can be reduced. As a result, it is possible to prevent the edge of the display panel 500b located above the display region 501a from being visible.

[0454] Furthermore, by providing flexibility to each display panel 500, display panel 500b can be gently curved so that the height of the upper surface of display region 501b of display panel 500b matches the height of the upper surface of display region 501a of display panel 500a. Therefore, the heights of the display regions can be made uniform except for the vicinity of the area where display panels 500a and 500b overlap, thereby improving the display quality of images displayed in display region 551 of stacked panel 550.

[0455] Although the relationship between the display panel 500a and the display panel 500b has been described above as an example, the same applies to the relationship between two adjacent display panels.

[0456] Furthermore, it is preferable that the thickness of the display panel 500 is thin in order to reduce the step between two adjacent display panels 500. For example, it is preferable that the thickness of the display panel 500 is 1 mm or less, preferably 300 μm or less, and more preferably 100 μm or less.

[0457] Furthermore, a substrate (for example, the second substrate in the first embodiment) may be provided to protect the display region 551 of the stacked panel 550. In this case, the substrate may be provided for each display panel, or one substrate may be provided across multiple display panels.

[0458] Although a configuration in which four display panels 500 are stacked is shown here, an extremely large stacked panel can be created by increasing the number of display panels 500. Furthermore, by changing the arrangement of the multiple display panels 500, the contour shape of the display area of ​​the stacked panel can be made into various shapes, such as a circle, an ellipse, or a polygon. Furthermore, by arranging the display panels 500 three-dimensionally, a stacked panel having a display area with a three-dimensional shape can be realized.

[0459] [Application example] The laminated panel can be installed along the curved surface of the interior or exterior wall of a house or building, or the interior or exterior of a vehicle. Figure 20 shows an example of installing a laminated panel according to one embodiment of the present invention in a vehicle.

[0460] FIG. 20 shows an example of the configuration of a vehicle equipped with a display unit 5001. The above-described laminated panel is applied to the display unit 5001. Although FIG. 20 shows an example in which the display unit 5001 is installed in a right-hand drive vehicle, this is not particularly limited, and the display unit can also be installed in a left-hand drive vehicle. In this case, the left and right arrangements of the configuration shown in FIG. 20 are reversed.

[0461] 20 shows a dashboard 5002, a steering wheel 5003, a windshield 5004, and the like, which are arranged around the driver's seat and passenger seat. A display unit 5001 is arranged at a predetermined position on the dashboard 5002, specifically around the driver, and has a roughly T-shape. While FIG. 20 shows an example in which one display unit 5001 formed using a plurality of display panels 5007 (display panels 5007a, 5007b, 5007c, 5007d) is provided along the dashboard 5002, the display unit 5001 may be arranged in multiple locations.

[0462] 20, display units 5009a and 5009b are provided along the surfaces of passenger door 5008a and driver door 5008b, respectively. Display units 5009a and 5009b can be formed using one or more display panels.

[0463] Display unit 5009a and display unit 5009b are arranged to face each other, and display unit 5001 is provided on dashboard 5002 so as to connect an end of display unit 5009a with an end of display unit 5009b. This results in the driver and passenger in the front seat being surrounded in front and on both sides by display unit 5001, display unit 5009a, and display unit 5009b. For example, by displaying a continuous image on display unit 5009a, display unit 5001, and display unit 5009b, it is possible to provide the driver and passenger with a highly immersive feeling.

[0464] The plurality of display panels 5007 may be flexible. In this case, the display unit 5001 can be processed into a complex shape, and it is possible to easily realize a configuration in which the display unit 5001 is provided along a curved surface such as the dashboard 5002, or a configuration in which the display area of ​​the display unit 5001 is not provided on the connection part of the steering wheel, the display part of the instrument, the air vent 5006, or the like.

[0465] 20 shows an example in which the camera 5005 is installed instead of the side mirror, but both the side mirror and the camera may be installed.

[0466] A CCD camera, a CMOS camera, or the like can be used as the camera 5005. In addition to these cameras, an infrared camera may also be used in combination. The output level of an infrared camera increases as the temperature of the subject increases, so it is possible to detect or extract living organisms such as people and animals.

[0467] The images captured by the camera 5005 can be output to one or more of the display panels 5007. This display unit 5001 is used mainly to assist driving of the vehicle. By capturing images of the rear and lateral conditions with a wide angle of view using the camera 5005 and displaying the images on the display panel 5007, the driver can see blind spots, thereby preventing accidents from occurring.

[0468] Furthermore, by using the display system according to one embodiment of the present invention, discontinuity in an image at the joints between the display panels 5007a, 5007b, 5007c, and 5007d can be compensated for, which enables display of an image with inconspicuous joints and improves visibility of the display portion 5001 while driving.

[0469] Furthermore, a range image sensor may be provided on the roof of the vehicle, and an image obtained by the range image sensor may be displayed on the display unit 5001. As the range image sensor, an image sensor, a LIDAR (Light Detection and Ranging), or the like may be used. By displaying the image obtained by the image sensor and the image obtained by the range image sensor on the display unit 5001, more information can be provided to the driver, and driving assistance can be provided.

[0470] Display unit 5001 may also have a function for displaying map information, traffic information, television images, DVD images, etc. For example, display panels 5007a, 5007b, 5007c, and 5007d can be used as a single display screen to display large map information. The number of display panels 5007 can be increased depending on the images to be displayed.

[0471] Furthermore, the images displayed on display panels 5007a, 5007b, 5007c, and 5007d can be freely set according to the driver's preferences. For example, television images and DVD images can be displayed on left display panel 5007d, map information can be displayed on central display panel 5007b, instruments can be displayed on right display panel 5007c, and audio equipment can be displayed on display panel 5007a near the gearbox (between the driver's seat and passenger seat). Furthermore, by combining multiple display panels 5007, a fail-safe function can be added to display unit 5001. For example, even if one display panel 5007 fails for some reason, the display area can be changed and another display panel 5007 can be used for display.

[0472] The images displayed on display units 5009a and 5009b can also be freely set according to the preferences of the driver or passenger. For example, if a child is sitting in the passenger seat, content for children, such as animation, can be displayed on display unit 5009a.

[0473] Furthermore, the display units 5009a and 5009b can display images that are linked to the view from the vehicle windows, synthesized from images acquired by the camera 5005 or the like. That is, images that the driver and passengers can see through the doors 5008a and 5008b can be displayed on the display units 5009a and 5009b. This allows the driver and passengers to experience the sensation of floating.

[0474] A display panel having an imaging function is preferably applied to at least one of the display panels 5007a, 5007b, 5007c, and 5007d. A display panel having an imaging function can also be applied to one or more of the display panels provided in the display units 5009a and 5009b.

[0475] For example, when the driver touches the display panel, the vehicle can perform biometric authentication such as fingerprint authentication or palm print authentication. The vehicle may have a function to adjust the environment to suit the driver's preferences when the driver is authenticated by biometric authentication. For example, it is preferable to perform one or more of the following after authentication: adjusting the seat position, adjusting the steering wheel position, adjusting the direction of the camera 5005, setting the brightness, setting the air conditioner, setting the wiper speed (frequency), setting the audio volume, and reading out the audio playlist.

[0476] Furthermore, when the driver is authenticated by biometric authentication, the car can be put into a state where it can be driven, for example, with the engine running, which is preferable because it eliminates the need for a key, which was previously required.

[0477] This embodiment mode can be implemented by appropriately combining at least a part thereof with other embodiment modes described in this specification.

[0478] (Embodiment 5) In this embodiment, a metal oxide (also referred to as an oxide semiconductor) that can be used for the transistor described in the above embodiment will be described.

[0479] The metal oxide preferably contains at least indium or zinc. It is particularly preferable that it contains indium and zinc. It is also preferable that it contains aluminum, gallium, yttrium, tin, or the like in addition to these. It may also contain one or more elements selected from boron, silicon, titanium, iron, nickel, germanium, zirconium, molybdenum, lanthanum, cerium, neodymium, hafnium, tantalum, tungsten, magnesium, cobalt, and the like.

[0480] Furthermore, metal oxides can be formed by sputtering, chemical vapor deposition (CVD) such as metal organic chemical vapor deposition (MOCVD), atomic layer deposition (ALD), or the like.

[0481] <Classification of crystal structures> Examples of the crystalline structure of oxide semiconductors include amorphous (including completely amorphous), c-axis-aligned crystalline (CAAC), nanocrystalline (nc), cloud-aligned composite (CAC), single crystal, and polycrystal.

[0482] The crystalline structure of a film or substrate can be evaluated using X-ray diffraction (XRD) spectra. For example, it can be evaluated using XRD spectra obtained by GIXD (Grazing-Incidence XRD) measurements. The GIXD method is also called the thin film method or the Seemann-Bohlin method.

[0483] For example, for a quartz glass substrate, the peak shape of the XRD spectrum is nearly symmetrical. On the other hand, for an IGZO film with a crystalline structure, the peak shape of the XRD spectrum is asymmetrical. The asymmetrical peak shape of the XRD spectrum clearly indicates the presence of crystals in the film or substrate. In other words, if the peak shape of the XRD spectrum is not symmetrical, the film or substrate cannot be said to be in an amorphous state.

[0484] The crystalline structure of a film or substrate can also be evaluated by the diffraction pattern (also called the nanobeam electron diffraction pattern) observed using nanobeam electron diffraction (NBED). For example, a halo is observed in the diffraction pattern of a quartz glass substrate, confirming that the quartz glass is in an amorphous state. Furthermore, a spot-like pattern is observed in the diffraction pattern of an IGZO film deposited at room temperature, rather than a halo. For this reason, it is estimated that an IGZO film deposited at room temperature is neither crystalline nor amorphous, but is in an intermediate state, and it cannot be concluded that it is in an amorphous state.

[0485] <<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 divided 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.

[0486] Here, the above-mentioned CAAC-OS, nc-OS, and a-like OS will be described in detail.

[0487] [CAAC-OS] CAAC-OS is an oxide semiconductor having multiple crystalline regions, each with its c-axis aligned in a specific direction. The specific direction can be the thickness direction of the CAAC-OS film, the normal direction to the surface on which the CAAC-OS film is formed, or the normal direction to the surface of the CAAC-OS film. A crystalline region is a region with periodic atomic arrangement. If the atomic arrangement is considered as a lattice arrangement, a crystalline region can also be a region with a uniform lattice arrangement. Furthermore, CAAC-OS has a region where multiple crystalline regions are connected in the ab-plane direction, and the region may have distortion. Note that distortion refers to a location where the lattice arrangement changes between a region with a uniform lattice arrangement and a region with a different uniform lattice arrangement in the region where multiple crystalline regions are connected. In other words, CAAC-OS is an oxide semiconductor with a c-axis aligned but no clear orientation in the ab-plane direction.

[0488] Each of the multiple crystalline regions is composed of one or more minute crystals (crystals with a maximum diameter of less than 10 nm). When a crystalline region is composed of one minute crystal, the maximum diameter of the crystalline region is less than 10 nm. When a crystalline region is composed of many minute crystals, the size of the crystalline region may be several tens of nm.

[0489] In an In-M-Zn oxide (wherein 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 referred to as an In layer) and a layer containing M, zinc (Zn), and oxygen (hereinafter referred to as an (M, Zn) layer) are stacked. Note that indium and the element M are mutually substituted. Therefore, the (M, Zn) layer may contain indium. The In layer may contain M. 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.

[0490] When the CAAC-OS film is subjected to structural analysis using, for example, an XRD apparatus, 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 metallic elements constituting the CAAC-OS.

[0491] For example, in the electron diffraction pattern of a CAAC-OS film, multiple bright spots are observed, and the spots are observed at positions that are point-symmetric with respect to the spot of the incident electron beam that has passed through the sample (also called the direct spot).

[0492] When the crystalline region is observed from the specific direction, the lattice arrangement within the crystalline region is basically a hexagonal lattice, but the unit cell is not necessarily a regular hexagon and may be non-regular hexagonal. Furthermore, the distortion may have a pentagonal, heptagonal, or other lattice arrangement. In the CAAC-OS, no clear grain boundaries are observed even near the distortion. This indicates 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 lack of close-packed oxygen atom arrangement in the ab-plane direction and the change in interatomic bond distance caused by metal atom substitution.

[0493] A crystal structure with clear grain boundaries is called polycrystalline. Grain boundaries act as recombination centers, trapping carriers and potentially causing a decrease in the on-state current and field-effect mobility of a transistor. Therefore, CAAC-OS, which lacks clear grain boundaries, is one of the crystalline oxides with a crystal structure suitable for use in the semiconductor layer of a transistor. Zn is preferred for use in CAAC-OS. For example, In-Zn oxide and In-Ga-Zn oxide are suitable because they can suppress the generation of grain boundaries more effectively than In oxide.

[0494] CAAC-OS is an oxide semiconductor with high crystallinity and no clear crystal grain boundaries. Therefore, it can be said that the CAAC-OS is less susceptible to a decrease in electron mobility due to crystal grain boundaries. Furthermore, since the crystallinity of an oxide semiconductor can be reduced by impurities or defects, the CAAC-OS can be said to be an oxide semiconductor with few impurities and defects (such as oxygen vacancies). Therefore, oxide semiconductors with CAAC-OS have stable physical properties. Therefore, oxide semiconductors with CAAC-OS are heat-resistant and highly reliable. Furthermore, the CAAC-OS is stable even under high temperatures (so-called thermal budgets) during the manufacturing process. Therefore, using a CAAC-OS for an OS transistor can increase the flexibility of the manufacturing process.

[0495] [nc-OS] The nc-OS has periodic atomic arrangement in a microscopic region (e.g., a region of 1 nm to 10 nm, particularly a region of 1 nm to 3 nm). In other words, the nc-OS has microcrystalline structures. The size of the microcrystalline structures is, for example, 1 nm to 10 nm, particularly 1 nm to 3 nm, and therefore these microcrystalline structures are also called nanocrystalline structures. Furthermore, the nc-OS exhibits no regularity in the crystal orientation between different nanocrystalline structures. Therefore, the entire film lacks orientation. Therefore, depending on the analytical method, the nc-OS may be indistinguishable from an a-like OS or an amorphous oxide semiconductor. For example, when a structural analysis of an nc-OS film is performed using an XRD apparatus, no peaks indicating crystallinity are detected in out-of-plane XRD measurements using θ / 2θ scanning. Furthermore, when an nc-OS film is subjected to electron diffraction (also known as selected-area electron diffraction) using an electron beam with a probe diameter larger than that of nanocrystalline structures (e.g., 50 nm or larger), a halo-like diffraction 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 close to or smaller than the size of the nanocrystals (for example, 1 nm to 30 nm), an electron diffraction pattern can be obtained in which multiple spots are observed within a ring-shaped region centered on the direct spot.

[0496] [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 pore or low-density region. That is, the a-like OS has lower crystallinity than the nc-OS and CAAC-OS. Furthermore, the a-like OS has a higher hydrogen concentration in the film than the nc-OS and CAAC-OS.

[0497] <<Oxide semiconductor structure>> Next, the above-mentioned CAC-OS will be described in detail, which relates to the material composition.

[0498] [CAC-OS] CAC-OS is a material structure 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 a similar size range. Hereinafter, a metal oxide in which one or more metal elements are unevenly distributed and the regions containing the metal elements are mixed in a size range of 0.5 nm to 10 nm, preferably 1 nm to 3 nm, or a similar size range, is also referred to as a mosaic or patch state.

[0499] Furthermore, CAC-OS has a mosaic structure in which the material is separated into first and second regions, and the first regions are distributed throughout the film (hereinafter also referred to as a cloud structure). That is, CAC-OS is a composite metal oxide having a structure in which the first and second regions are mixed.

[0500] Here, the atomic ratios of In, Ga, and Zn to the metal elements constituting the CAC-OS in the In-Ga-Zn oxide are denoted as [In], [Ga], and [Zn], respectively. For example, in the CAC-OS in the In-Ga-Zn oxide, the first region is a region where [In] is larger than [In] in the composition of the CAC-OS film. The second region is a region where [Ga] is larger than [Ga] in the composition of the CAC-OS film. Alternatively, for example, the first region is a region where [In] is larger than [In] in the second region and [Ga] is smaller than [Ga] in the second region. The second region is a region where [Ga] is larger than [Ga] in the first region and [In] is smaller than [In] in the first region.

[0501] Specifically, the first region is a region whose main component is indium oxide, indium zinc oxide, or the like. The second region is a region whose main component is gallium oxide, gallium zinc oxide, or the like. In other words, the first region can be rephrased as a region whose main component is In. The second region can be rephrased as a region whose main component is Ga.

[0502] It should be noted that there are cases where a clear boundary between the first region and the second region cannot be observed.

[0503] In addition, CAC-OS in In-Ga-Zn oxide refers to a material structure containing In, Ga, Zn, and O, in which some regions primarily composed of Ga and other regions primarily composed of In are randomly arranged in a mosaic pattern. Therefore, it is presumed that CAC-OS has a structure in which metal elements are distributed nonuniformly.

[0504] The CAC-OS can be formed, for example, by a sputtering method without heating the substrate. When the CAC-OS is formed by a sputtering method, one or more of an inert gas (typically argon), oxygen gas, and nitrogen gas may be used as the deposition gas. The lower the flow rate ratio of oxygen gas to the total flow rate of deposition gas during deposition, the better. 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.

[0505] Furthermore, for example, in the case of CAC-OS in an In-Ga-Zn oxide, EDX mapping obtained using EDX (Energy Dispersive X-ray spectroscopy) confirms that the CAC-OS has a structure in which a region containing In as a main component (first region) and a region containing Ga as a main component (second region) are unevenly distributed and mixed.

[0506] Here, the first region has higher conductivity than the second region. That is, the flow of carriers through the first region causes the metal oxide to exhibit conductivity. Therefore, the first region is distributed in a cloud-like manner in the metal oxide, thereby achieving a high field-effect mobility (μ).

[0507] On the other hand, the second region has higher insulating properties than the first region. That is, the second region is distributed in the metal oxide, thereby suppressing leakage current.

[0508] 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 complementarily, thereby providing the CAC-OS with a switching function (the ability to turn on / off). 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, both functions can be maximized. Therefore, by using CAC-OS in a transistor, a high on-current (I on ), high field-effect mobility (μ), and good switching behavior can be achieved.

[0509] Furthermore, a transistor using CAC-OS has high reliability, making it ideal for various semiconductor devices such as display devices.

[0510] Oxide semiconductors have a variety of structures, each with 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.

[0511] <Transistors containing oxide semiconductors> Next, a case where the oxide semiconductor is used in a transistor will be described.

[0512] By using the oxide semiconductor for a transistor, a transistor with high field-effect mobility and high reliability can be realized.

[0513] For the transistor, an oxide semiconductor with a low carrier concentration is preferably used. For example, the carrier concentration of the oxide semiconductor is 1×10 17 cm -3 Less than 1 × 10 15 cm -3 or less, more preferably 1 × 10 13 cm -3Less than or equal to 1×10 11 cm -3 or less, more preferably 1 × 10 10 cm -3 Less than 1 x 10 -9 cm -3 That is all. Note that in order to reduce the carrier concentration of an oxide semiconductor film, the impurity concentration in the oxide semiconductor film may be reduced to reduce the density of defect states. In this specification and the like, a semiconductor having a low impurity concentration and a low density of defect states is referred to as a highly purified intrinsic or substantially highly purified intrinsic oxide semiconductor. Note that an oxide semiconductor having a low carrier concentration may also be referred to as a highly purified intrinsic or substantially highly purified intrinsic oxide semiconductor.

[0514] Furthermore, a highly purified intrinsic or substantially highly purified intrinsic oxide semiconductor film has a low density of defect states, and therefore the density of trap states may also be low.

[0515] Furthermore, charges trapped in the trap states of an oxide semiconductor take a long time to disappear and may behave like fixed charges. Therefore, a transistor in which a channel formation region is formed in an oxide semiconductor with a high density of trap states may have unstable electrical characteristics.

[0516] Therefore, in order to stabilize the electrical characteristics of a transistor, it is effective to reduce the impurity concentration in the oxide semiconductor. Furthermore, in order to reduce the impurity concentration in the oxide semiconductor, it is preferable to also reduce the impurity concentration in the adjacent film. Examples of impurities include hydrogen, nitrogen, alkali metals, alkaline earth metals, iron, nickel, and silicon.

[0517] <Impurities> Here, the influence of each impurity in an oxide semiconductor will be described.

[0518] When an oxide semiconductor contains silicon or carbon, which is one of the Group 14 elements, defect levels are formed in the oxide semiconductor. Therefore, 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 calculated to be 2×10 18 atoms / cm 3 Less than or equal to 2 x 10 17 atoms / cm 3 The following applies.

[0519] Furthermore, when an oxide semiconductor contains an alkali metal or alkaline earth metal, defect levels may be formed and carriers may be generated. Therefore, a transistor using an oxide semiconductor containing an alkali metal or alkaline earth metal is likely to have normally-on characteristics. Therefore, when the concentration of the alkali metal or alkaline earth metal in the oxide semiconductor obtained by SIMS is 1×10 18 atoms / cm 3 Less than or equal to 2 x 10 16 atoms / cm 3 Do the following:

[0520] 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 tends 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 the 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 Do the following:

[0521] Furthermore, hydrogen contained in an oxide semiconductor may react 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. Furthermore, 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 the amount of hydrogen in the oxide semiconductor as much as possible. Specifically, 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.

[0522] When an oxide semiconductor with sufficiently reduced impurities is used for a channel formation region of a transistor, stable electrical characteristics can be obtained.

[0523] This embodiment mode can be implemented by appropriately combining at least a part thereof with other embodiment modes described in this specification.

[0524] (Sixth embodiment) In this embodiment, electronic devices of one embodiment of the present invention will be described with reference to FIGS.

[0525] An electronic device of one embodiment of the present invention can capture an image with a display portion, detect a touch operation, etc. This can improve the functionality, convenience, and the like of the electronic device.

[0526] Examples of electronic devices according to one embodiment of the present invention include electronic devices with relatively large screens, such as television sets, desktop or notebook personal computers, computer monitors, digital signage, and large game machines such as pachinko machines, as well as digital cameras, digital video cameras, digital photo frames, mobile phones, portable game machines, personal digital assistants, and sound reproduction devices.

[0527] An electronic device according to one embodiment of the present invention may have a sensor (including a function for measuring force, displacement, position, velocity, acceleration, angular velocity, rotation speed, distance, light, liquid, magnetism, temperature, chemical substance, sound, time, hardness, electric field, current, voltage, power, radiation, flow rate, humidity, gradient, vibration, odor, or infrared rays).

[0528] The electronic device of one embodiment of the present invention can have various functions, such as a function to display various information (still images, videos, text images, etc.) on a display portion, a touch panel function, a function to display a calendar, date, time, etc., a function to execute various software (programs), a wireless communication function, a function to read programs or data recorded on a recording medium, etc.

[0529] Electronic device 6500 shown in FIG. 21A is a portable information terminal that can be used as a smartphone.

[0530] 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.

[0531] The display device described in Embodiment 2 can be applied to the display portion 6502.

[0532] FIG. 21B is a schematic cross-sectional view including the end of the housing 6501 on the microphone 6506 side.

[0533] 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.

[0534] A display panel 6511, an optical member 6512, and a touch sensor panel 6513 are fixed to the protective member 6510 by adhesive layers (not shown).

[0535] In an area outside the display unit 6502, a part of the display panel 6511 is folded back, and an FPC 6515 is connected to the folded back part. An IC 6516 is mounted on the FPC 6515. The FPC 6515 is connected to a terminal provided on a printed circuit board 6517.

[0536] 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 keeping the thickness of the electronic device small. Furthermore, 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.

[0537] When the display device described in Embodiment 2 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 for fingerprint authentication.

[0538] The display portion 6502 further includes a touch sensor panel 6513, which allows the display portion 6502 to have a touch panel function. The touch sensor panel 6513 can be of any of various types, such as a capacitive type, a resistive 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.

[0539] 22A 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.

[0540] The display device described in Embodiment 2 can be applied to the display portion 7000.

[0541] 22A 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 in the display unit 7000, and the television 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. The channel and volume can be controlled using the operation keys or touch panel provided on the remote control 7111, and the video displayed on the display unit 7000 can be controlled.

[0542] The television device 7100 is configured to include a receiver, a modem, and the like. The receiver can receive general television broadcasts. In addition, by connecting to a wired or wireless communication network via the modem, it is possible to perform one-way (from sender to receiver) or two-way (between sender and receiver, or between receivers, etc.) information communication.

[0543] 22B 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, and an external connection port 7214. The housing 7211 includes a display portion 7000.

[0544] The display device described in Embodiment 2 can be applied to the display portion 7000.

[0545] 22C and 22D show an example of digital signage.

[0546] 22C includes a housing 7301, a display unit 7000, and a speaker 7303. The digital signage 7300 may further include an LED lamp, operation keys (including a power switch or an operation switch), a connection terminal, various sensors, a microphone, and the like.

[0547] 22D shows a digital signage 7400 attached to a cylindrical pillar 7401. The digital signage 7400 has a display unit 7000 provided along the curved surface of the pillar 7401.

[0548] 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 will attract people's attention, which can increase the advertising effectiveness of, for example, advertisements.

[0549] 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 to provide information such as route information or traffic information, intuitive operation can improve usability.

[0550] 22C and 22D, it is preferable that digital signage 7300 or digital signage 7400 can wirelessly link with information terminal 7311 or information terminal 7411, such as a smartphone carried by a user. For example, advertising information displayed on display unit 7000 can be displayed on the screen of information terminal 7311 or information terminal 7411. Furthermore, by operating information terminal 7311 or information terminal 7411, the display on display unit 7000 can be switched.

[0551] 22C and 22D, the display device described in Embodiment 2 can be applied to the display portion of the information terminal 7311 or the information terminal 7411.

[0552] Furthermore, it is also possible to run a game 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), thereby allowing an unspecified number of users to simultaneously participate in and enjoy the game.

[0553] The electronic device shown in Figures 23A to 23F 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 the function of measuring force, displacement, position, speed, acceleration, angular velocity, rotation speed, distance, light, liquid, magnetism, temperature, chemical substance, sound, time, hardness, electric field, current, voltage, power, radiation, flow rate, humidity, gradient, vibration, odor or infrared rays), a microphone 9008, etc.

[0554] The electronic devices shown in Figures 23A to 23F have various functions. For example, they may have a function to display various information (still images, videos, text images, etc.) on a display unit, a touch panel function, a function to display a calendar, date, or time, a function to control processing using various software (programs), a wireless communication function, a function to read and process programs or data recorded on a recording medium, etc. Note that the functions of the electronic devices are not limited to these, and they may have various other functions. The electronic devices may have multiple display units. Furthermore, the electronic devices may have a function to include a camera or the like to capture still images or videos and store them on a recording medium (external or built-in to the camera), a function to display the captured images on the display unit, etc.

[0555] The electronic devices shown in FIGS. 23A to 23F will be described in detail below.

[0556] FIG. 23A 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, image information, and the like on multiple surfaces thereof. FIG. 23A shows an example in which three icons 9050 are displayed. Information 9051, indicated by a dashed rectangle, can also be displayed on another surface of the display unit 9001. Examples of the information 9051 include notifications of incoming emails, SNS messages, phone calls, and the like, the titles of emails, SNS messages, and the like, the sender's name, the date and time, the remaining battery level, and the strength of antenna reception. Alternatively, the icon 9050 or the like may be displayed in the position where the information 9051 is displayed.

[0557] 23B is a perspective view showing mobile information terminal 9102. Mobile information terminal 9102 has a function of displaying information on three or more sides of display unit 9001. Here, an example is shown in which information 9052, information 9053, and information 9054 are displayed on different sides. For example, while carrying mobile information terminal 9102 in a breast pocket of clothes, the user can check information 9053 displayed in a position that can be observed from above mobile information terminal 9102. The user can check the display without taking mobile information terminal 9102 out of their pocket and decide, for example, whether to answer a call.

[0558] FIG. 23C is a perspective view showing a wristwatch-type mobile information terminal 9200. The mobile information terminal 9200 can be used as, for example, a smart watch. 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 calling by communicating with, for example, a headset capable of wireless communication. The mobile information terminal 9200 can also perform data transmission and charging with another information terminal through a connection terminal 9006. Charging may be performed by wireless power supply.

[0559] 23D to 23F are perspective views showing a foldable mobile information terminal 9201. FIG. 23D shows the mobile information terminal 9201 in an unfolded state, FIG. 23F shows it in a folded state, and FIG. 23E is a perspective view showing a state in the process of changing from one of FIG. 23D and FIG. 23F to the other. The mobile information terminal 9201 is highly portable when folded, and has a seamless, wide display area when unfolded, providing excellent viewability of the display. 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 curvature radius of 0.1 mm or more and 150 mm or less.

[0560] This embodiment mode can be implemented by appropriately combining at least a part thereof with other embodiment modes described in this specification. [Example]

[0561] In this example, a light-receiving element according to one embodiment of the present invention was manufactured and its characteristics were evaluated. The results are described.

[0562] In this example, two light receiving elements (Samples A1 and A2) were fabricated. The two light receiving elements fabricated in this example had the same configuration except for the configuration of the active layer.

[0563] The chemical formulas of the materials used in this example are shown below.

[0564] [ka]

[0565] The specific configuration of the light-receiving element fabricated in this example is shown in Table 1. The configuration of the light-receiving element can be based on the light-receiving element 270PD illustrated in Fig. 10A. In this example, a buffer layer was formed on the common electrode 275.

[0566] [Table 1]

[0567] The pixel electrode 271 (also referred to as the first electrode) was formed by depositing an alloy of silver (Ag), palladium (Pd), and copper (Cu) (Ag-Pd-Cu(APC)) by sputtering to a thickness of 100 nm, and by depositing indium tin oxide containing silicon oxide (ITSO) by sputtering to a thickness of 100 nm.

[0568] Next, the base material on which the pixel electrode 271 was formed was washed with water, baked at 200°C for 1 hour, and then subjected to UV ozone treatment for 370 seconds. -4 The substrate was placed in a vacuum deposition apparatus whose internal pressure had been reduced to about Pa, and vacuum baking was performed at 170° C. for 30 minutes in the heating chamber of the vacuum deposition apparatus. Thereafter, the substrate was allowed to cool for about 30 minutes.

[0569] The hole injection layer 281 was formed by co-evaporation of N,N-bis(4-biphenyl)-6-phenylbenzo[b]naphtho[1,2-d]furan-8-amine (abbreviation: BBABnf) and an electron acceptor material (OCHD-001) in a weight ratio of BBABnf:OCHD-001 = 1:0.10. The hole injection layer 281 was formed to a thickness of 10 nm.

[0570] The hole transport layer 282 was formed by vapor deposition of BBABnf to a thickness of 40 nm.

[0571] The active layer 273 in Sample A1 is made of fullerene C 70 and tetraphenyldibenzoperiflanthene (abbreviation: DBP) in a weight ratio of C 70 The active layer 273 was formed by co-evaporation so that the ratio of the active layer 273 to the total active layer 273 was 9:1. The active layer 273 was formed to a thickness of 60 nm.

[0572] The active layer 273 in Sample A2 was formed by depositing N,N'-dimethyl-3,4,9,10-perylenetetracarboxylic acid diimide (abbreviation: Me-PTCDI) to a thickness of 54 nm, and then depositing Rubrene to a thickness of 6 nm.

[0573] The electron transport layer 284 was formed by evaporating 2-[3'-(dibenzothiophen-4-yl)biphenyl-3-yl]dibenzo[f,h]quinoxaline (abbreviation: 2mDBTBPDBq-II) to a thickness of 10 nm, followed by evaporating 2,9-bis(naphthalen-2-yl)-4,7-diphenyl-1,10-phenanthroline (abbreviation: NBPhen) to a thickness of 10 nm.

[0574] The electron injection layer 285 was formed by vapor deposition of lithium fluoride (LiF) to a thickness of 1 nm.

[0575] The common electrode 275 (also referred to as a second electrode) was formed by co-evaporation of silver (Ag) and magnesium (Mg) at a volume ratio of 10:1 to a thickness of 10 nm.

[0576] Furthermore, a buffer layer was formed on the common electrode 275 by vapor deposition of 4,4′,4″-(benzene-1,3,5-triyl)tri(dibenzothiophene) (abbreviation: DBT3P-II) to a thickness of 80 nm.

[0577] In this manner, Sample A1 and Sample A2, each having a different active layer structure, were fabricated.

[0578] Table 2 shows the HOMO level, LUMO level, and film-forming temperature for the active layer materials of each photodiode. The film-forming temperature is also shown below the film-forming rate. It can be seen that the active layer used in Sample A2 is a combination of materials that allows for a lower film-forming temperature and a faster film-forming rate compared to Sample A1.

[0579] [Table 2]

[0580] Figures 24A and 24B show the wavelength dependence of the absorption coefficient of the active layer material. Figure 24A shows Sample A1, and Figure 24B shows Sample A2. In each figure, the horizontal axis shows wavelength (λ [nm]) and the vertical axis shows normalized absorption coefficient.

[0581] As shown in Figure 24A, in Sample A1, the absorption of the acceptor extends to the long wavelength side. In addition, in Sample A1, the weight of the acceptor is set to 90 wt %. Therefore, Sample A1 is a photodetector with sensitivity over a wide range of the visible light region.

[0582] On the other hand, as shown in Figure 24B, in Sample A2, the absorption of the acceptor and donor is located in the green wavelength region. In particular, the donor has a sharp absorption peak in a narrower wavelength region than the acceptor. In Sample A2, the donor occupies 90% of the entire active layer, so Sample A2 is a photodiode with high sensitivity in the green wavelength region.

[0583] Next, the current-voltage characteristics of each photodetector were measured. The measurements were performed using monochromatic light of 525 nm at an irradiance of 12.5 μW / cm. 2 The measurements were carried out under light irradiation (denoted as Photo) and in a dark state (denoted as Dark), respectively. Figures 25A and 25B show the current-voltage characteristics. Figure 25A shows the measurement results for Sample A1, and Figure 25B shows the measurement results for Sample A2. In each figure, the horizontal axis represents voltage (V [V]) and the vertical axis represents current density (J [mA / cm 2 ]).

[0584] As shown in FIGS. 25A and 25B, it was confirmed that both Sample A1 and Sample A2 exhibited good saturation characteristics.

[0585] 26A shows the wavelength dependence of the external quantum efficiency (EQE). The EQE was measured at a voltage of −4 V and an irradiance of 12.5 μW / cm 2In Fig. 26A, the horizontal axis represents wavelength (λ [nm]) and the vertical axis represents EQE ([%]).

[0586] Figure 26A shows that both photodetectors have the highest peak sensitivity around 525 nm. Furthermore, Sample A1 has broader sensitivity, especially on the long wavelength side, compared to Sample A2. On the other hand, Sample A2 has selective sensitivity in the green wavelength range.

[0587] Next, the reliability of each light-receiving element was evaluated. To evaluate reliability, a white LED was used to irradiate the light-receiving element with 5000K light at an illuminance of 100 klux, and the current density was measured under the conditions of a voltage of -4V and a temperature of 25°C. Figure 26B shows the measurement results for each light-receiving element. In Figure 26B, the horizontal axis shows time (Time [h]) and the vertical axis shows normalized current density (J, normalized). As shown in Figure 26B, it was confirmed that all light-receiving elements had high reliability. [Explanation of symbols]

[0588] 10, 10a, 10b: Display device: 11, 12: Substrate: 13, 14: Resin layer: 15: Functional layer: 16: Resin layer: 17: Protective layer: 20: Light receiving element: 21: Conductive layer: 22: Photoelectric conversion layer: 23: Conductive layer: 25: Light-shielding layer: 30, 30R, 30G, 30B: Light emitting element: 31: Conductive layer: 32: EL layer: 40, 40a: Pixel: 41: Insulating layer: 42: Protective layer: 43: Conductive layer: 50: Finger: 51, 52: Light: 55: Resin layer: 56a, 56b, 57: Conductive layer: 58: Insulating layer, 500, 500a-5 00d: Display panel: 501, 501a to 501d: Display area: 510, 510b to 510d: Area: 512a to 512d: FPC: 520, 520b, 520c: Area: 550: Laminated panel, 551: Display area, 5001: Display unit: 5002: Dashboard: 5003: Steering wheel: 5004: Windshield: 5005: Camera: 5006: Air vent: 5007, 5007a to 5007d: Display panel: 5008a, 5008b: Door: 5009a, 5009b: Display unit

Claims

1. A first display panel and a second display panel are included, The first display panel and the second display panel each include: a display area having a plurality of pixels; a first region that has an area disposed adjacent to at least a part of the display region in a plan view and that has a function of transmitting visible light; a second region that has an area disposed adjacent to at least a part of the display region in a plan view and has a function of blocking visible light; a display area of ​​the first display panel overlaps with a first area of ​​the second display panel; At least one of the plurality of pixels is a display device having a light emitting element and a light receiving element, At least one of the first display panel and the second display panel a first substrate; a first resin layer having a region located above the first substrate; a light-shielding layer having a region located above the first resin layer; a second resin layer having a region located above the light-shielding layer; a second substrate having a region located above the second resin layer, the light-receiving element has a region located between the first substrate and the first resin layer, the light-emitting element has a region located between the first substrate and the first resin layer, the light-shielding layer has a first opening overlapping the light-receiving element, the light-shielding layer has a region in which the first opening is located inside a light-receiving region of the light-receiving element in a plan view, and the width of the first opening is equal to or smaller than the width of the light-receiving region in a cross-sectional view; the second substrate is thicker than the first resin layer and the second resin layer; the first resin layer has a region where a thickness of a portion overlapping the light receiving region of the light receiving element is 1 to 10 times the width of the light receiving region, a refractive index of the second substrate with respect to the wavelength of light emitted by the light-emitting element is higher than the refractive index of the first resin layer and is also higher than the refractive index of the second resin layer.

2. In claim 1, the light receiving element has a first pixel electrode, an active layer, and a common electrode; the light-emitting element has a second pixel electrode, a light-emitting layer, and the common electrode; the first pixel electrode and the second pixel electrode are located on the same plane; the common electrode has a portion that overlaps with the first pixel electrode via the active layer, and a portion that overlaps with the second pixel electrode via the light-emitting layer.

3. In claim 2, having a common layer, a common layer having a portion located between the first pixel electrode and the common electrode, a portion located between the second pixel electrode and the common electrode, and a portion that does not overlap with either the first pixel electrode or the second pixel electrode.

Images