Display devices, display modules and electronic devices

Abstract

A display device with light detection function is provided. A highly convenient display device is also provided. One embodiment of the present invention is a display device comprising a light-receiving element, a first light-emitting element, and a second light-emitting element in a display section. The light-receiving element includes a first pixel electrode, an active layer, and a common electrode. The first light-emitting element includes a second pixel electrode, a first light-emitting layer, and a common electrode. The second light-emitting element includes a third pixel electrode, a second light-emitting layer, and a common electrode. The active layer comprises an organic compound. The active layer is located between the first pixel electrode and the common electrode. The first light-emitting layer is located between the second pixel electrode and the common electrode. The second light-emitting layer is located between the third pixel electrode and the common electrode. The first light-emitting layer is also located between one or both of the first pixel electrode and the common electrode and the third pixel electrode and the common electrode.

Description

Technical Field

[0001] One embodiment of the present invention relates to a display device, a display module, and an electronic device. One embodiment of the present invention relates to a display device including a light-receiving element and a light-emitting element.

[0002] Note that one embodiment of the present invention is not limited to the aforementioned technical fields. Examples of the technical fields encompassing one embodiment of the present invention include semiconductor devices, display devices, light-emitting devices, power storage devices, memory devices, electronic devices, lighting equipment, input devices (e.g., touch sensors), input / output devices (e.g., touch panels), and methods for driving or manufacturing these devices. Prior Art

[0003] In recent years, display devices have been anticipated for a variety of applications. For example, large-scale display devices include home televisions (also known as TVs or TV receivers), digital signage, and public information displays (PIDs). Furthermore, research and development is underway on smartphones and tablets equipped with touch panels as portable information terminals.

[0004] For example, light-emitting devices including light-emitting elements have been developed as display devices. Light-emitting elements (also referred to as "EL elements") that utilize the electroluminescence (EL) phenomenon are easily thinner and lighter, can respond to input signals quickly, and can be driven using a low-voltage DC power supply. Consequently, they have been used in display devices. For example, Patent Document 1 discloses a flexible light-emitting device using an organic EL element.

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

[0006] One object of one embodiment of the present invention is to provide a display device with a light detection function. One object of one embodiment of the present invention is to provide a display device with high convenience. One object of one embodiment of the present invention is to provide a display device with multiple functions. One object of one embodiment of the present invention is to provide a display device with a high aperture ratio. One object of one embodiment of the present invention is to provide a display device with a high resolution. One object of one embodiment of the present invention is to provide a novel display device.

[0007] One purpose of one embodiment of the present invention is to improve the yield of a display device with a light detection function. One purpose of one embodiment of the present invention is to reduce the number of manufacturing processes for a display device with a light detection function. One purpose of one embodiment of the present invention is to reduce the manufacturing cost of a display device with a light detection function.

[0008] Note that the inclusion of these objectives does not preclude the existence of other objectives. An embodiment of the present invention does not necessarily achieve all of the aforementioned objectives. Objectives other than the aforementioned objectives may be extracted from the specification, drawings, and claims.

[0009] A display device according to one embodiment of the present invention includes a light-receiving element, a first light-emitting element, and a second light-emitting element in a display portion. The light-receiving element includes a first pixel electrode, an active layer, and a common electrode. The first light-emitting element includes a second pixel electrode, a first light-emitting layer, and a common electrode. The second light-emitting element includes a third pixel electrode, a second light-emitting layer, and a common electrode. The active layer includes an organic compound. The active layer is located between the first pixel electrode and the common electrode. The first light-emitting layer is located between the second pixel electrode and the common electrode. The second light-emitting layer is located between the third pixel electrode and the common electrode. The first light-emitting layer is also located between one or both of the first pixel electrode and the common electrode and the third pixel electrode and the common electrode.

[0010] A display device according to one embodiment of the present invention includes a light-receiving element and a first light-emitting element in a display portion. The light-receiving element includes a first pixel electrode, an active layer, a first light-emitting layer, and a common electrode. The first light-emitting element includes a second pixel electrode, a first light-emitting layer, and a common electrode. The active layer includes an organic compound. The active layer is located between the first pixel electrode and the common electrode. The first light-emitting layer is located between the first pixel electrode and the common electrode, and between the second pixel electrode and the common electrode.

[0011] In the display device of the above structure, the display portion preferably further includes a second light-emitting element. The second light-emitting element preferably includes a third pixel electrode, a first light-emitting layer, a second light-emitting layer, and a common electrode. Each of the first light-emitting layer and the second light-emitting layer is preferably located between the third pixel electrode and the common electrode. The first light-emitting element preferably emits light emitted by the first light-emitting layer. The second light-emitting element preferably emits light emitted by the second light-emitting layer.

[0012] In addition, in the display device of the above structure, the first light-emitting element preferably further includes an active layer. The active layer is preferably located between the second pixel electrode and the common electrode.

[0013] A display device according to one embodiment of the present invention includes, in a display portion, a light-receiving element, a first light-emitting element, a second light-emitting element, a first color layer, and a second color layer. The light-receiving element includes a first pixel electrode, an active layer, and a common electrode. The first light-emitting element includes a second pixel electrode, a first light-emitting layer, and a common electrode. The second light-emitting element includes a third pixel electrode, a first light-emitting layer, and a common electrode. The active layer includes an organic compound. The active layer is located between the first pixel electrode and the common electrode. The first light-emitting layer is located between the second pixel electrode and the common electrode, and between the third pixel electrode and the common electrode. Light emitted by the first light-emitting element transmits through the first color layer and is extracted from the display portion as light of the first color. Light emitted by the second light-emitting element transmits through the second color layer and is extracted from the display portion as light of the second color.

[0014] In the display device of the above structure, the first and second light-emitting elements preferably further include a second light-emitting layer. The second light-emitting layer is preferably located between the second pixel electrode and the common electrode, and between the third pixel electrode and the common electrode. The first and second light-emitting layers preferably emit light of different wavelengths.

[0015] In the display device with the above structure, the display portion preferably further includes a third light-emitting element and a third color layer. The third light-emitting element preferably includes a fourth pixel electrode, a third light-emitting layer, and a common electrode. The third light-emitting layer is preferably located between the second pixel electrode and the common electrode, between the third pixel electrode and the common electrode, and between the fourth pixel electrode and the common electrode. Light emitted by the third light-emitting element preferably transmits through the third color layer and is extracted from the display portion as light of a third color.

[0016] In the display devices of the above structures, the light-receiving element and the first light-emitting element preferably further include a common layer. The common layer is preferably located between the first pixel electrode and the common electrode and between the second pixel electrode and the common electrode.

[0017] In the display devices of each of the above structures, the display portion preferably further includes a partition wall. The partition wall preferably covers an end portion of the first pixel electrode and an end portion of the second pixel electrode. The partition wall preferably functions to electrically insulate the first pixel electrode from the second pixel electrode. The partition wall preferably functions to absorb at least a portion of the light emitted by the first light-emitting element.

[0018] In the display devices of each of the above structures, the display portion preferably further includes a colored layer. The colored layer preferably has a portion that contacts one or both of the top and side surfaces of the partition wall. The colored layer preferably includes a color filter or a black matrix.

[0019] In the display devices of each of the above structures, the display unit preferably further includes a lens. The lens preferably has a portion overlapping with the light receiving element. Light transmitted through the lens preferably enters the light receiving element. The display unit preferably further includes a light shielding layer. An end portion of the light shielding layer preferably overlaps with an end portion of the lens. The light shielding layer preferably overlaps with the partition wall.

[0020] In the display devices of the above-mentioned structures, the display portion is preferably flexible.

[0021] One embodiment of the present invention is a module including a display device having any of the above-described structures, wherein the module is mounted with a connector such as a flexible printed circuit (FPC) or a tape carrier package (TCP), or is mounted with an integrated circuit (IC) using a chip-on-glass (COG) or chip-on-film (COF) method.

[0022] One embodiment of the present invention is an electronic device including at least one of the above-mentioned module, an antenna, a battery, a housing, a camera, a speaker, a microphone, and an operation button.

[0023] According to one embodiment of the present invention, a display device with a light detection function can be provided. According to one embodiment of the present invention, a display device with high convenience can be provided. According to one embodiment of the present invention, a multifunctional display device can be provided. According to one embodiment of the present invention, a display device with a high aperture ratio can be provided. According to one embodiment of the present invention, a display device with a high resolution can be provided. According to one embodiment of the present invention, a novel display device can be provided.

[0024] According to one embodiment of the present invention, the manufacturing yield of a display device with a light detection function can be improved. According to one embodiment of the present invention, the number of manufacturing processes for a display device with a light detection function can be reduced. According to one embodiment of the present invention, the manufacturing cost of a display device with a light detection function can be reduced.

[0025] Note that the inclusion of these effects does not preclude the existence of other effects. An embodiment of the present invention does not necessarily have all of the effects described above. Effects other than those described above may be extracted from the description, drawings, and patent claims. Simple diagram description

[0026] In the diagram: [FIG. 1A] to [FIG. 1D] are cross-sectional views showing an example of a display device, and [FIG. 1E] to [FIG. 1H] are top views showing an example of a pixel; [Figure 2] is a cross-sectional view showing an example of a display device; [FIG. 3A], [FIG. 3B] are cross-sectional views showing an example of a display device; [FIG. 4A] and [FIG. 4B] are cross-sectional views showing an example of a display device; [FIG. 5A] and [FIG. 5B] are cross-sectional views showing an example of a display device; [FIG. 6A] and [FIG. 6B] are cross-sectional views showing an example of a display device; [FIG. 7A] and [FIG. 7B] are cross-sectional views showing an example of a display device; [FIG. 8A] to [FIG. 8C] are cross-sectional views showing an example of a display device; [FIG. 9A] to [FIG. 9C] are cross-sectional views showing an example of a display device; [Figure 10] is a perspective view showing an example of a display device; [Figure 11] is a cross-sectional view showing an example of a display device; [FIG. 12A] and [FIG. 12B] are cross-sectional views showing an example of a display device; [FIG. 13A] is a cross-sectional view showing an example of a display device, and [FIG. 13B] is a cross-sectional view showing an example of a transistor; [Figure 14] is a cross-sectional view showing an example of a display device; [FIG. 15A] and [FIG. 15B] are circuit diagrams showing an example of a pixel circuit; [FIG. 16A] and [FIG. 16B] are diagrams showing an example of a method for driving a display device; [FIG. 17A] and [FIG. 17B] are diagrams showing an example of a method for driving a display device; [FIG. 18A] and [FIG. 18B] are diagrams showing an example of an electronic device; [FIG. 19A] to [FIG. 19D] are diagrams showing an example of an electronic device; [FIG. 20A] to [FIG. 20F] are diagrams showing an example of an electronic device; [Figure 21] is a diagram showing the voltage-luminance characteristics of the light-emitting element; [Figure 22] is a diagram showing the brightness-external quantum efficiency characteristics of the light-receiving and light-emitting element; [Figure 23] is a graph showing the wavelength dependence of the light sensitivity of a light-receiving and light-emitting element. The selection diagram of the present invention is Figure 2. Implementation Method

[0027] The embodiments are described in detail with reference to the accompanying drawings. Note that the present invention is not limited to the following description. Those skilled in the art will readily understand that the embodiments and details can be modified in various ways without departing from the spirit and scope of the present invention. Therefore, one embodiment of the present invention should not be construed as being limited to the following embodiments.

[0028] Note that in the following description of the inventive structure, identical components or components having the same function are often referenced in different figures using the same reference numerals, omitting any duplication of description. Furthermore, components having the same function may be referenced using the same hatching without any specific reference numerals.

[0029] Furthermore, for ease of understanding, the positions, sizes, and ranges of various components shown in the drawings may not necessarily represent their actual positions, sizes, and ranges. Therefore, the disclosed invention is not necessarily limited to the positions, sizes, and ranges disclosed in the drawings.

[0030] In addition, depending on the situation or state, the terms "film" and "layer" can be interchanged. For example, "conductive layer" can be replaced with "conductive film." Also, for example, "insulating film" can be replaced with "insulating layer."

[0031] Implementation Method 1 In this embodiment, a display device according to one embodiment of the present invention is described with reference to FIG. 1 to FIG. 13 .

[0032] The display device of this embodiment includes a light-receiving element and a light-emitting element in the display portion. The light-emitting elements in the display portion of the display device of this embodiment are arranged in a matrix, thereby enabling the display portion to display images. Furthermore, the light-receiving elements in the display portion are arranged in a matrix, so the display portion also has one or both of a camera function and a sensing function. The display portion can be used as an image sensor and a touch sensor. In other words, by performing light detection in the display portion, images can be captured and the approach or contact of an object (such as a finger or pen) can be detected. Furthermore, the display device of this embodiment can use the light-emitting element as the light source of the sensor. This eliminates the need for a separate light-receiving unit and light source outside the display device, thereby reducing the number of components in the electronic device.

[0033] In the display device of this embodiment, when light emitted by the light-emitting element included in the display portion is reflected by an object, the light-receiving element can detect the reflected light, so that imaging and contact (and approach) detection can be achieved even in dark places.

[0034] The display device of this embodiment can display images using a light-emitting element. In other words, the light-emitting element is used as a display element.

[0035] Preferred light-emitting elements include EL devices such as OLEDs (Organic Light Emitting Diodes) and QLEDs (Quantum-dot Light Emitting Diodes). Examples of luminescent materials used in EL devices include fluorescent materials, phosphorescent materials, inorganic compounds (such as quantum dot materials), and materials that exhibit thermally activated delayed fluorescence (TADF materials). Alternatively, LEDs such as microLEDs (Light Emitting Diodes) can be used as light-emitting elements.

[0036] The display device of this embodiment can detect light using a light-receiving element.

[0037] When the light receiving element is used as an image sensor, the display device of this embodiment can use the light receiving element to capture images.

[0038] For example, by using an image sensor, data such as fingerprints, palm prints, and irises can be acquired. In other words, the display device of this embodiment can be built with a biometric sensor. Compared to installing a separate biometric sensor outside the display device, building a biometric sensor into the display device reduces the number of components in the electronic device, thereby achieving a smaller and lighter electronic device.

[0039] Furthermore, by using image sensors, data such as the user's facial expressions, eye movements, and pupil contraction can be captured. This data can be analyzed to obtain information about the user's physical and mental state. By adjusting the output of one or both visual and audio content based on this information, users can safely use devices such as VR (Virtual Reality), AR (Augmented Reality), and MR (Mixed Reality).

[0040] In addition, when a light-receiving element is used as a touch sensor, the display device of this embodiment can detect the approach or contact of an object using the light-receiving element.

[0041] For example, a pn-type or pin-type photodiode can be used as a light-receiving element. A light-receiving element functions as a photoelectric conversion element that detects light incident on the element and generates charge. The amount of charge generated depends on the amount of incident light.

[0042] In particular, organic photodiodes containing an organic compound layer are preferably used as light-receiving elements. Organic photodiodes can be easily made thinner, lighter, and larger in size, and have high flexibility in shape and design, making them suitable for various display devices.

[0043] In one embodiment of the present invention, an organic EL element is used as the light-emitting element, and an organic photodiode is used as the 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.

[0044] Separately manufacturing all layers that make up the organic EL element and the organic photodiode requires a significant number of film-forming steps. Since the organic photodiode includes multiple layers that can share the same structure as the organic EL element, forming these layers simultaneously can minimize the increase in film-forming steps. Furthermore, even with the same number of film-forming steps, reducing the number of layers formed in only some elements can reduce the effects of pattern misalignment and debris (including microscopic foreign matter called particles) adhering to film-forming masks (such as metal masks). This can improve the manufacturing yield of display devices.

[0045] In a display device according to one embodiment of the present invention, the light-emitting layer included in a first light-emitting element emitting light of a first color is shared by one or both of a light-receiving element and a second light-emitting element emitting light of a second color. This reduces the number of layers required for the light-receiving element, the first light-emitting element, and the second light-emitting element, thereby improving the manufacturing yield of the display device.

[0046] In addition, it is preferred that at least one of the hole injection layer, the hole transport layer, the electron transport layer, and the electron injection layer is a layer shared by the light-receiving element, the first light-emitting element, and the second light-emitting element. This can reduce the number of film formations and the number of masks, thereby reducing the process and manufacturing costs of the display device. Note that sometimes a layer shared by the light-receiving element, the first light-emitting element, and the second light-emitting element has different functions in the light-emitting element and the light-receiving element. In this specification, structural elements are referred to according to their functions in the light-emitting element. For example, the hole injection layer is used as a hole injection layer in the light-emitting element and as a hole transport layer in the light-receiving element. Similarly, the electron injection layer is used as an electron injection layer in the light-emitting element and as an electron transport layer in the light-receiving element.

[0047] 1A to 1D are cross-sectional views illustrating a display device according to an embodiment of the present invention.

[0048] A display device 50A shown in FIG. 1A includes a layer 53 including light-receiving elements and a layer 57 including light-emitting elements between a substrate 51 and a substrate 59 .

[0049] A display device 50B shown in FIG. 1B includes a layer 53 including light-receiving elements, a layer 55 including transistors, and a layer 57 including light-emitting elements between a substrate 51 and a substrate 59 .

[0050] The display device 50A and the display device 50B have a structure in which red (R), green (G), and blue (B) lights are emitted from a layer 57 including light-emitting elements.

[0051] The light-receiving elements included in the layer 53 having light-receiving elements can detect light incident from outside the display device 50A or the display device 50B.

[0052] A display device according to one embodiment of the present invention includes a plurality of pixels arranged in a matrix. One pixel includes one or more sub-pixels. One sub-pixel includes one light-emitting element. For example, a pixel may have a structure including three sub-pixels (three colors of R, G, and B, or three colors of yellow (Y), cyan (C), and magenta (M), etc.) or a structure including four sub-pixels (four colors of R, G, B, and white (W), or four colors of R, G, B, and Y, etc.). Furthermore, the pixel includes a light-receiving element. The light-receiving element may be provided in all pixels or in a portion of the pixels. Alternatively, one pixel may include multiple light-receiving elements.

[0053] The layer 55 having transistors preferably includes a first transistor and a second transistor. The first transistor is electrically connected to the light-receiving element, and the second transistor is electrically connected to the light-emitting element.

[0054] The display device according to one embodiment of the present invention may also have a function for detecting objects such as a finger touching the display device. For example, as shown in FIG1C , when light emitted by a light-emitting element in layer 57 having light-emitting elements is reflected by finger 52 touching display device 50B, the light-receiving element in layer 53 having light-receiving elements detects the reflected light. This allows detection of finger 52 touching display device 50B.

[0055] As shown in FIG. 1D , the display device according to one embodiment of the present invention may also have a function of detecting or capturing an object that is close to (not in contact with) the display device 50B.

[0056] [Pixels] 1E to 1H illustrate an example of a pixel.

[0057] The pixels shown in Figures 1E and 1F include three R, G, and B sub-pixels (three light-emitting elements) and a light-receiving element PD. Figure 1E shows an example of three sub-pixels and light-receiving elements PD arranged in a 2×2 matrix, while Figure 1F shows three sub-pixels and light-receiving elements PD arranged horizontally.

[0058] The pixel shown in FIG 1G includes four sub-pixels (four light-emitting elements) of R, G, B, and W and a light-receiving element PD.

[0059] The pixel shown in Figure 1H includes three sub-pixels (R, G, and B), a light-emitting element IR that emits infrared light, and a light-receiving element PD. In this case, the light-receiving element PD preferably has the function of detecting infrared light. Alternatively, the light-receiving element PD can detect both visible light and infrared light. The wavelength of light detected by the light-receiving element PD can be determined based on the sensor's intended use.

[0060] 2 to 7 , the detailed structures of the light-emitting element and the light-receiving element included in the display device according to one embodiment of the present invention will be described.

[0061] The display device of one embodiment of the present invention can adopt any of the following structures: a top emission structure that emits light in a direction opposite to the substrate on which the light-emitting element is formed; a bottom emission structure that emits light in the same direction as the substrate on which the light-emitting element is formed; or a double-sided emission structure that emits light from both sides.

[0062] In FIG. 2 to FIG. 7 , a display device with a top emission structure is taken as an example for description.

[0063] Note that in this specification, unless otherwise noted, even when describing a structure including multiple elements (e.g., light-emitting elements, light-emitting layers), the letters of the symbols are omitted when describing common portions of the elements. For example, when describing common portions of light-emitting layer 193R and light-emitting layer 193G, these may be referred to as light-emitting layer 193.

[0064] [Structure example 1] First, the display device shown in FIG. 2 , FIG. 3A , and FIG. 3B will be described.

[0065] The display device shown in Figures 2, 3A, and 3B includes a light-emitting element 47B emitting blue (B) light, a light-emitting element 47G emitting green (G) light, a light-emitting element 47R emitting red (R) light, and a light-receiving element 46 on a substrate 151 via a layer 55 having transistors.

[0066] Each of the light-emitting element 47B, the light-emitting element 47G, and the light-emitting element 47R includes a pixel electrode 191 and a common electrode 115. In this embodiment, the case where the pixel electrode 191 is used as an anode and the common electrode 115 is used as a cathode is described as an example.

[0067] The light-receiving element 46 includes a pixel electrode 181 and a common electrode 115. In this embodiment, similar to the light-emitting element, the pixel electrode 181 is used as an anode and the common electrode 115 is used as a cathode. Specifically, by applying a reverse bias voltage between the pixel electrode 181 and the common electrode 115 to drive the light-receiving element 46, light incident on the light-receiving element 46 is detected, charge is generated, and then extracted as current.

[0068] Pixel electrodes 191 and 181 can be formed using the same material and the same process. The pixel electrodes 191 included in each light-emitting element are electrically insulated from each other (also referred to as electrically isolated). Furthermore, the pixel electrodes 181 included in the light-receiving element 46 are electrically insulated from the pixel electrodes 191 included in each light-emitting element.

[0069] The common electrode 115 is commonly used in the light receiving element 46 , the light emitting element 47B, the light emitting element 47G, and the light emitting element 47R.

[0070] The materials and film thicknesses of the pair of electrodes included in the light-receiving element 46, the light-emitting element 47B, the light-emitting element 47G, and the light-emitting element 47R can be the same. Therefore, the manufacturing cost of the display device can be reduced and the manufacturing process can be simplified.

[0071] In the display device shown in Figures 2, 3A, and 3B, light-emitting layer 193B is provided not only in light-emitting element 47B that emits blue light, but also in light-emitting element 47R that emits red light, light-emitting element 47G that emits green light, and light-receiving element 46. In light-emitting element 47R, light-emitting element 47G, and light-receiving element 46, light-emitting layer 193B functions as a carrier transport layer (in this embodiment, an electron transport layer).

[0072] By reducing the number of layers formed separately for each element, display device manufacturing can be simplified. Compared to providing light-emitting layer 193B only in light-emitting element 47B, providing it also in light-emitting elements emitting other colors and light-receiving elements can reduce the impact of pattern misalignment of light-emitting layer 193B, thereby improving the manufacturing yield of the display device.

[0073] Furthermore, when forming light-emitting layer 193B in a separate film formation chamber from buffer layers 192B and 194B, a separate mask is required for forming light-emitting layer 193B. In this case, by employing a structure in which light-receiving element 46, light-emitting element 47B, light-emitting element 47G, and light-emitting element 47R share light-emitting layer 193B, the number of masks required for film formation can be reduced, thereby reducing manufacturing costs.

[0074] Furthermore, since the substrate and mask must be aligned with high precision, it sometimes takes time to set the mask, and deviations during alignment can sometimes affect the display quality of the manufactured display device. Using fewer masks is preferred, as it shortens display device manufacturing time and improves yield.

[0075] The structure of the display device shown in FIG. 2 will be described in detail.

[0076] The light-emitting element 47B includes a buffer layer 192B, a light-emitting layer 193B, and a buffer layer 194B in this order on the pixel electrode 191. The light-emitting layer 193B includes a light-emitting material that emits blue light. The light-emitting element 47B has a function of emitting blue light.

[0077] The light-emitting element 47G includes a buffer layer 192G, a light-emitting layer 193G, a light-emitting layer 193B, and a buffer layer 194G in this order on the pixel electrode 191. The light-emitting layer 193G includes a light-emitting material that emits green light. The light-emitting element 47G has a function of emitting green light.

[0078] The light emitting element 47R includes a buffer layer 192R, a light emitting layer 193R, a light emitting layer 193B, and a buffer layer 194R in this order on the pixel electrode 191. The light emitting layer 193R contains a light emitting material that emits red light. The light emitting element 47R has a function of emitting red light.

[0079] The light receiving element 46 includes a buffer layer 182, an active layer 183, a light emitting layer 193B, and a buffer layer 184 in this order on the pixel electrode 181. The active layer 183 contains an organic compound. The light receiving element 46 has the function of detecting one or both of visible light and infrared light.

[0080] The pixel electrode 181, the pixel electrode 191, the buffer layer 182, the buffer layer 192R, the buffer layer 192G, the buffer layer 192B, the active layer 183, the light-emitting layer 193R, the light-emitting layer 193G, the light-emitting layer 193B, the buffer layer 184, the buffer layer 194R, the buffer layer 194G, the buffer layer 194B and the common electrode 115 can be a single-layer structure or a stacked-layer structure.

[0081] The light-emitting layer 193B is commonly used in the light-emitting element 47B, the light-emitting element 47G, the light-emitting element 47R, and the light-receiving element 46. Meanwhile, the light-emitting layer 193G, the light-emitting layer 193R, and the active layer 183 are layers formed separately in each element. The light-emitting layer 193G is provided in the light-emitting element 47G, the light-emitting layer 193R is provided in the light-emitting element 47R, and the active layer 183 is provided in the light-receiving element 46.

[0082] Buffer layer 182 may include a hole transport layer. Buffer layers 192B, 192G, and 192R may include one or both of a hole injection layer and a hole transport layer. Buffer layer 184 may include an electron transport layer. Buffer layers 184, 194B, 194G, and 194R may include one or both of an electron injection layer and an electron transport layer.

[0083] The hole injection layer is a layer containing a material with high hole-injection properties that injects holes from the anode into the light-emitting element. Examples of such materials include aromatic amine compounds and composite materials containing a hole-transporting material and an acceptor material (electron acceptor material).

[0084] In a light-emitting element, the hole transport layer is a layer that transports holes injected from the anode to the light-emitting layer via the hole injection layer. In a light-receiving element, the hole transport layer is a layer that transports holes generated by light incident on the active layer to the anode. The hole transport layer is a layer containing a hole-transporting material. As a hole-transporting material, it is preferred to use a substance with a hole mobility of 1×10-6cm2 / Vs or more. Note that as long as the hole transport property is higher than the electron transport property, substances other than those listed above can be used. As a hole-transporting material, it is preferred to use a material with high hole-transporting properties such as a π-electron-rich heteroaromatic compound (for example, carbazole derivatives, thiophene derivatives, furan derivatives, etc.) or an aromatic amine (a compound containing an aromatic amine skeleton).

[0085] In a light-emitting element, the electron transport layer transports electrons injected from the cathode to the light-emitting layer via the electron injection layer. In a light-receiving element, the electron transport layer transports electrons generated by light incident on the active layer to the cathode. The electron transport layer is a layer containing an electron-transporting material. Electron-transporting materials preferably have an electron mobility of 1×10⁻⁶ cm² / Vs or higher. Note that materials other than those listed above may be used as long as their electron-transporting properties are higher than their hole-transporting properties. As electron-transporting materials, materials with high electron-transporting properties such as metal complexes containing a quinoline skeleton, metal complexes containing a benzoquinoline skeleton, metal complexes containing an oxadiazole skeleton, metal complexes containing a thiazole skeleton, diazole derivatives, triazole derivatives, imidazole derivatives, oxadiazole derivatives, thiazole derivatives, phenanthroline derivatives, quinoline derivatives containing a quinoline ligand, benzoquinoline derivatives, quinoline derivatives, dibenzoquinoline derivatives, pyridine derivatives, bipyridine derivatives, pyrimidine derivatives, and nitrogen-containing heteroaromatic compounds, etc., can be used.

[0086] The electron injection layer is a layer containing a material with high electron-injection properties, which injects electrons from the cathode into the light-emitting element. Examples of such materials include alkali metals, alkaline earth metals, or compounds containing these substances. Alternatively, composite materials containing an electron-transporting material and a donor material (electron-donating material) may be used.

[0087] The light-emitting element included in a display device according to one embodiment of the present invention preferably employs a microscopic optical resonator (microcavity) structure. Therefore, one of the pair of electrodes included in the light-emitting element preferably comprises an electrode that is both transmissive and reflective to visible light (a semi-transmissive / semi-reflective electrode), while the other preferably comprises an electrode that is reflective to visible light (a reflective electrode). By employing a microcavity structure in the light-emitting element, the light emitted from the light-emitting layer resonates between the two electrodes, thereby enhancing the light emitted from the light-emitting element.

[0088] Furthermore, the semi-transmissive / semi-reflective electrode can have a laminated structure comprising a reflective electrode and an electrode transmissive to visible light (also called a transparent electrode). In this specification, the reflective electrode, which serves as part of the semi-transmissive / semi-reflective electrode, is sometimes referred to as a pixel electrode or a common electrode, and the transparent electrode is sometimes referred to as an optical adjustment layer. However, in some cases, the transparent electrode (optical adjustment layer) also functions as a pixel electrode or a common electrode.

[0089] The light transmittance of the transparent electrode is set to 40% or higher. For example, a light-emitting element preferably uses an electrode with a visible light (light with a wavelength of 400 nm or more and less than 750 nm) transmittance of 40% or higher. Furthermore, the visible light reflectance of the semi-transmissive / semi-reflective electrode is set to 10% or higher and 95% or lower, preferably 30% or higher and 80% or lower. The visible light reflectance of the reflective electrode is set to 40% or higher and 100% or lower, preferably 70% or higher and 100% or lower. Furthermore, the resistivity of the electrode is preferably 1×10-2 Ωcm or lower. Furthermore, when a light-emitting element emitting near-infrared light is used in a display device, the transmittance and reflectance of the electrode for near-infrared light (light with a wavelength of 750 nm or more and 1300 nm or lower) are preferably within the above-mentioned numerical ranges.

[0090] Buffer layers 182, 192B, 192G, and 192R can also function as optical adjustment layers. Specifically, for light-emitting element 47B, the thickness of buffer layer 192B is preferably adjusted so that the optical distance between the pair of electrodes enhances blue light. Similarly, for light-emitting element 47G, the thickness of buffer layer 192G is preferably adjusted so that the optical distance between the pair of electrodes enhances green light. Furthermore, for light-emitting element 47R, the thickness of buffer layer 192R is preferably adjusted so that the optical distance between the pair of electrodes enhances red light. By varying the thickness of buffer layer 192 or buffer layer 194, light of a specific color can be enhanced and extracted in each light-emitting element. Note that when the semi-transmissive / semi-reflective electrode employs a stacked structure of a reflective electrode and a transparent electrode, the optical distance between the pair of electrodes represents the optical distance between the pair of reflective electrodes.

[0091] The structure of the display device shown in FIG. 3A will be described in detail.

[0092] In addition to the structure of the display device shown in FIG. 2 , the display device shown in FIG. 3A further includes a common layer 112 and a common layer 114 .

[0093] By making at least a portion of the layers constituting the light-emitting element and the light-receiving element have the same structure, the manufacturing process of the display device can be reduced, which is preferable.

[0094] Specifically, light-emitting element 47B shown in FIG3A includes common layer 112 between pixel electrode 191 and buffer layer 192B, and common layer 114 between buffer layer 194B and common electrode 115. Similarly, light-emitting element 47G shown in FIG3A includes common layer 112 between pixel electrode 191 and buffer layer 192G, and common layer 114 between buffer layer 194G and common electrode 115. Furthermore, light-emitting element 47R shown in FIG3A includes common layer 112 between pixel electrode 191 and buffer layer 192R, and common layer 114 between buffer layer 194R and common electrode 115. Furthermore, light-emitting element 46 shown in FIG3A includes common layer 112 between pixel electrode 181 and buffer layer 182, and common layer 114 between buffer layer 184 and common electrode 115.

[0095] The common layer 112 and the common layer 114 can be a single-layer structure or a stacked-layer structure.

[0096] For example, common layer 112 preferably includes one or both of a hole injection layer and a hole transport layer. For example, common layer 114 may include one or both of an electron injection layer and an electron transport layer. Sometimes, the functions of common layer 112 and common layer 114 in the light-emitting element differ from those in the light-receiving element. For example, when common layer 112 includes a hole injection layer, the hole injection layer serves as a hole injection layer in the light-emitting element and as a hole transport layer in the light-receiving element. Similarly, when common layer 114 includes an electron injection layer, the electron injection layer serves as an electron injection layer in the light-emitting element and as an electron transport layer in the light-receiving element.

[0097] As an example of the display device shown in Figure 3A, the following structure can be cited: the common layer 112 includes a hole injection layer, the buffer layers 182, 192B, 192G, and 192R include hole transport layers, the buffer layers 184, 194B, 194G, and 194R include electron transport layers, and the common layer 114 includes an electron injection layer.

[0098] The common layer 112 and the common layer 114 are provided on the pixel electrode 181 and the pixel electrode 191. The common layer 112 and the common layer 114 are layers shared by the light-receiving element 46 and the light-emitting element 47.

[0099] The structure of the display device shown in FIG. 3B will be described in detail.

[0100] The display device shown in FIG. 3B differs from the display device shown in FIG. 3A in that the buffer layers 182 , 192 , 184 , 194 are not included but common layers 112 , 114 are included.

[0101] The light-emitting element 47B includes a common layer 112 between the pixel electrode 191 and the light-emitting layer 193B, and includes a common layer 114 between the light-emitting layer 193B and the common electrode 115.

[0102] The light-emitting element 47G includes a common layer 112 between the pixel electrode 191 and the light-emitting layer 193G, and includes a common layer 114 between the light-emitting layer 193B and the common electrode 115.

[0103] The light-emitting element 47R includes a common layer 112 between the pixel electrode 191 and the light-emitting layer 193R, and includes a common layer 114 between the light-emitting layer 193B and the common electrode 115.

[0104] The light-emitting element 46 includes a common layer 112 between the pixel electrode 181 and the active layer 183 , and includes a common layer 114 between the light-emitting layer 193B and the common electrode 115 .

[0105] As an example of the display device shown in FIG3B , the following structure can be cited: the common layer 112 includes a hole injection layer and a hole transport layer, and the common layer 114 includes an electron transport layer and an electron injection layer.

[0106] The display device shown in FIG3B illustrates an example in which light-receiving element 46 and light-emitting element 47 have the same structure, except that active layer 183 of light-receiving element 46, light-emitting layer 193R of light-emitting element 47R, and light-emitting layer 193G of light-emitting element 47G are formed separately. By using layers shared by light-receiving element 46 and light-emitting element 47 (common layers), the number of layers (buffer layers) fabricated separately for light-receiving element 46 and light-emitting element 47 can be reduced, allowing light-receiving element 46 to be integrated into the display device without significantly increasing the number of manufacturing processes.

[0107] In addition, in the display device shown in FIG3B , since the light emitting element 47B does not include a layer manufactured separately from other elements, the number of masks can be reduced. This can reduce the manufacturing cost of the display device.

[0108] [Structure Example 2] Next, the display device shown in FIG. 4A , FIG. 4B , FIG. 5A , and FIG. 5B will be described.

[0109] The display device shown in Figures 4A, 4B, 5A, and 5B includes, on substrate 151, light-emitting element 47B that emits blue (B) light, light-emitting element 47G that emits green (G) light, light-emitting element 47R that emits red (R) light, light-receiving element 46, color layer CFG, and color layer CFR, via layer 55 having transistors. The display device shown in Figure 5B also includes color layer CFB.

[0110] The light-emitting element 47B, the light-emitting element 47G, and the light-emitting element 47R include a pixel electrode 191 and a common electrode 115 .

[0111] The light receiving element 46 includes a pixel electrode 181 and a common electrode 115 .

[0112] The common electrode 115 is commonly used by the light-receiving element 46 and the light-emitting element 47 that emits light of each color.

[0113] In the display device shown in Figures 4A, 4B, and 5A, light-emitting element 47R and light-emitting element 47G share a common light-emitting layer. In Figures 4A and 4B, light-emitting element 47R and light-emitting element 47G include light-emitting layer 193R that emits red light and light-emitting layer 193G that emits green light. In Figure 5A, light-emitting element 47R and light-emitting element 47G include light-emitting layer 193Y that emits yellow light. Furthermore, light emitted by light-emitting element 47R passes through color layer CFR and is emitted from the display device as red light. Furthermore, light emitted by light-emitting element 47G passes through color layer CFG and is emitted from the display device as green light.

[0114] Compared to a case where light-emitting element 47R and light-emitting element 47G have separate layers, forming light-emitting element 47R and light-emitting element 47G with the same structure can reduce the number of film-forming steps and the number of masks. This can reduce the number of steps and manufacturing costs of the display device.

[0115] Furthermore, compared to a structure where light-emitting element 47R and light-emitting element 47G have separate layers, forming light-emitting element 47R and light-emitting element 47G with the same structure reduces the potential for misalignment. This increases the pixel aperture ratio and improves light extraction efficiency. A higher pixel aperture ratio reduces the sub-pixel brightness required to achieve a certain brightness in the display panel. This extends the life of the light-emitting elements, allowing the display device to display higher brightness. Furthermore, the display device's resolution can be improved.

[0116] In FIG5B , light-emitting elements 47R, 47G, and 47B share a common light-emitting layer. Each light-emitting element includes a light-emitting layer 193R that emits red light, a light-emitting layer 193G that emits green light, and a light-emitting layer 193B that emits blue light. Light emitted by light-emitting element 47R passes through color layer CFR and is emitted from the display device as red light. Furthermore, light emitted by light-emitting element 47G passes through color layer CFG and is emitted from the display device as green light. Furthermore, light emitted by light-emitting element 47B passes through color layer CFB and is emitted from the display device as blue light.

[0117] Compared to a case where light-emitting elements 47R, 47G, and 47B have structures formed of separate layers, forming light-emitting elements 47R, 47G, and 47B with the same structure can reduce the number of film-forming steps and masks. Consequently, the manufacturing process and manufacturing costs of the display device can be reduced.

[0118] Furthermore, compared to a structure where light-emitting elements 47R, 47G, and 47B are formed in separate layers, forming light-emitting elements 47R, 47G, and 47B with the same structure reduces the potential for misalignment. This increases the pixel aperture ratio and improves light extraction efficiency. A higher pixel aperture ratio reduces the sub-pixel brightness required to achieve a certain brightness in the display panel. This extends the life of the light-emitting elements. Furthermore, the display device can display higher brightness. Furthermore, the resolution of the display device can be improved.

[0119] The structure of the display device shown in FIG. 4A will be described in detail.

[0120] The light emitting element 47B includes the common layer 112, the buffer layer 192B, the light emitting layer 193B, and the common layer 114 in this order on the pixel electrode 191. The light emitting layer 193B includes a light emitting material that emits blue light. The light emitting element 47B has a function of emitting blue light.

[0121] Light-emitting element 47G and light-emitting element 47R include, in this order, common layer 112, buffer layer 192, light-emitting layer 193R, light-emitting layer 193G, and common layer 114 on pixel electrode 191. Light-emitting layer 193R contains a light-emitting material that emits red light. Light-emitting layer 193G contains a light-emitting material that emits green light. Light emitted by light-emitting element 47G passes through color layer CFG and is extracted as green light. Light emitted by light-emitting element 47R passes through color layer CFR and is extracted as red light.

[0122] The light receiving element 46 includes a common layer 112, a buffer layer 182, an active layer 183, and a common layer 114 in this order on the pixel electrode 181. The active layer 183 contains an organic compound. The light receiving element 46 has the function of detecting one or both of visible light and infrared light.

[0123] The light-emitting layer 193R and the light-emitting layer 193G are used in both the light-emitting element 47G and the light-emitting element 47R. Meanwhile, the light-emitting layer 193B and the active layer 183 are formed separately in each element. The light-emitting layer 193B is provided in the light-emitting element 47B, and the active layer 183 is provided in the light-receiving element 46.

[0124] As an example of the display device shown in Figure 4A, the following structure can be cited: the common layer 112 includes a hole injection layer, the buffer layers 182, 192B, and 192 include hole transport layers, and the common layer 114 includes one or both of an electron injection layer and an electron transport layer.

[0125] Note that while FIG4A illustrates an example where light-emitting element 47G and light-emitting element 47R have the same structure, light-emitting element 47G and light-emitting element 47R may also include optical adjustment layers of different thicknesses. For example, it is preferable to configure pixel electrode 191 to have a stacked structure of a reflective electrode and a transparent electrode on the reflective electrode, and to configure the transparent electrodes of light-emitting element 47G and light-emitting element 47R to have different thicknesses to achieve optical adjustment. Specifically, light-emitting element 47G may have a transparent electrode arranged such that the optical distance between the pair of electrodes enhances green light, and light-emitting element 47R may have a transparent electrode arranged such that the optical distance between the pair of electrodes enhances blue light. Furthermore, light-emitting element 47B may preferably be optically adjusted using buffer layer 192B such that the optical distance between the pair of electrodes enhances blue light. Similarly, light-receiving element 46 may preferably be optically adjusted using buffer layer 182 such that the optical distance between the pair of electrodes enhances the optical distance of the desired wavelength to be detected. Alternatively, both light-emitting element 47B and light-receiving element 46 may be provided with optical adjustment layers (transparent electrodes).

[0126] The structure of the display device shown in FIG. 4B will be described in detail.

[0127] The display device shown in FIG4B differs from the display devices shown in FIG4A and FIG5A in that the light-emitting layer 193B is not only provided in the light-emitting element 47B that emits blue light, but is also provided in the light-emitting elements 47R, 47G and the light-receiving element 46 that emit light of other colors.

[0128] In the light-emitting elements 47R and 47G and the light-receiving element 46 , the light-emitting layer 193B functions as a carrier transport layer (in this embodiment, an electron transport layer).

[0129] As in Structural Example 1, by reducing the number of layers formed separately for each element, display device manufacturing can be simplified. By also providing light-emitting layer 193B in the light-emitting elements emitting each color of light and the light-receiving elements, the effects of pattern misalignment of light-emitting layer 193B can be reduced, thereby improving the manufacturing yield of the display device, compared to providing light-emitting layer 193B only in light-emitting element 47B.

[0130] In addition, since no mask is required for forming the light emitting layer 193B, manufacturing costs can be reduced, manufacturing time can be shortened, and yield can be improved.

[0131] The structure of the display device shown in FIG. 5A will be described in detail.

[0132] The display device shown in FIG5A differs from the display device shown in FIG4A in that the light-emitting element 47R and the light-emitting element 47G do not include the light-emitting layer 193R emitting red light and the light-emitting layer 193G emitting green light, but include the light-emitting layer 193Y emitting yellow light.

[0133] By reducing the number of light-emitting layers included in the light-emitting element 47R and the light-emitting element 47G, the manufacturing process of the display device can be reduced.

[0134] 5A may also adopt the following structure: the light-emitting layer 193B is provided not only in the light-emitting element 47B that emits blue light, but also in the light-emitting elements 47R, 47G and the light-receiving element 46 that emit light of other colors.

[0135] The structure of the display device shown in FIG5B will be described in detail.

[0136] The display device shown in FIG5B differs from the display device shown in FIG4A in that light-emitting element 47R, light-emitting element 47G, and light-emitting element 47B have the same structure; and light emitted by light-emitting element 47B is taken out through color layer CFB.

[0137] Light-emitting elements 47R, 47G, and 47B include, in this order, common layer 112, buffer layer 192, light-emitting layers 193R, 193G, 193B, and common layer 114 on pixel electrode 191. Light-emitting layer 193R contains a light-emitting material that emits red light. Light-emitting layer 193G contains a light-emitting material that emits green light. Light-emitting layer 193B contains a light-emitting material that emits blue light. Light emitted by light-emitting element 47R passes through color layer CFR and is emitted from the display device as red light. Light emitted by light-emitting element 47G passes through color layer CFG and is emitted from the display device as green light. Light emitted by light-emitting element 47B passes through color layer CFB and is emitted from the display device as blue light.

[0138] In addition, the light-emitting element 47 can be a single structure including one light-emitting unit between the pixel electrode 191 and the common electrode 115, or a series structure including multiple light-emitting units.

[0139] The light receiving element 46 includes a common layer 112, a buffer layer 182, an active layer 183, and a common layer 114 in this order on the pixel electrode 181. The active layer 183 contains an organic compound. The light receiving element 46 has the function of detecting one or both of visible light and infrared light.

[0140] Light-emitting layers 193R, 193G, and 193B are commonly used in light-emitting elements 47R, 47G, and 47B. Compared to a case where light-emitting elements 47R, 47G, and 47B have structures formed of separate layers, forming light-emitting elements 47R, 47G, and 47B with the same structure can reduce the number of film-forming steps and the number of masks. This can reduce the number of steps and manufacturing costs of the display device.

[0141] 5B , the light-emitting element 47R, the light-emitting element 47G, the light-emitting element 47B, and the light-receiving element 46 may include optical adjustment layers having different film thicknesses.

[0142] [Structure Example 3] Next, the display device shown in FIG. 6A , FIG. 6B , FIG. 7A , and FIG. 7B will be described.

[0143] The display device shown in Figures 6A, 6B, 7A, and 7B has a light-emitting element 47B emitting blue (B) light, a light-emitting element 47G emitting green (G) light, a light-emitting element 47R emitting red (R) light, and a light-receiving element 46 provided on a substrate 151 via a layer 55 including transistors.

[0144] The light-emitting element 47B, the light-emitting element 47G, and the light-emitting element 47R each include a pixel electrode 191 and a common electrode 115 .

[0145] The light receiving element 46 includes a pixel electrode 181 and a common electrode 115 .

[0146] The common electrode 115 is commonly used by the light-receiving element 46 and the light-emitting element 47 that emits light of each color.

[0147] 6A , 7A , and 7B , light-receiving element 46 and light-emitting element 47R share light-emitting layer 193R and active layer 183 . In the display device shown in FIG 6B , light-receiving element 46 and light-emitting element 47G share light-emitting layer 193G and active layer 183 .

[0148] Here, light receiving element 46 can have the same structure as a light emitting element that emits light of a longer wavelength than the light to be detected. For example, light receiving element 46 configured to detect blue light can have the same structure as one or both of light emitting element 47R and light emitting element 47G. For example, light receiving element 46 configured to detect green light can have the same structure as light emitting element 47R.

[0149] Compared to a case where the light-receiving element 46, the light-emitting element 47R, or the light-emitting element 47G have separate layers, forming the light-receiving element 46, the light-emitting element 47R, or the light-emitting element 47G with the same structure can reduce the number of film-forming steps and the number of masks. This can reduce the number of steps and manufacturing costs of the display device.

[0150] Furthermore, compared to a structure where light-receiving element 46, light-emitting element 47R, or light-emitting element 47G are formed in separate layers, forming light-receiving element 46, light-emitting element 47R, or light-emitting element 47G with the same structure reduces the potential for misalignment. This increases the pixel aperture ratio and improves light extraction efficiency. A higher pixel aperture ratio reduces the sub-pixel brightness required to achieve a certain brightness in the display panel. This extends the life of the light-emitting element. Furthermore, the display device can display high brightness. Furthermore, the display device's resolution can be improved.

[0151] The structure of the display device shown in FIG. 6A will be described in detail.

[0152] The light emitting element 47B includes the common layer 112, the buffer layer 192B, the light emitting layer 193B, and the common layer 114 in this order on the pixel electrode 191. The light emitting layer 193B includes a light emitting material that emits blue light. The light emitting element 47B has a function of emitting blue light.

[0153] The light emitting element 47G includes the common layer 112, the buffer layer 192G, the light emitting layer 193G, and the common layer 114 in this order on the pixel electrode 191. The light emitting layer 193G includes a light emitting material that emits green light. The light emitting element 47G has a function of emitting green light.

[0154] The light-emitting element 47R and the light-receiving element 46 include, in order, a common layer 112, a buffer layer 182, a light-emitting layer 193R, an active layer 183, and a common layer 114 on the pixel electrode. The light-emitting layer 193R contains a luminescent material that emits red light. The active layer 183 includes an organic compound that absorbs light with a wavelength shorter than red light (for example, one or both of green and blue light). The active layer 183 preferably includes an organic compound that absorbs less red light and absorbs light with a wavelength shorter than red light. This allows red light to be efficiently extracted from the light-emitting element 47R, and the light-receiving element 46 can detect light with a wavelength shorter than red light with high accuracy.

[0155] FIG6A shows an example in which light-emitting element 47R and light-receiving element 46 have the same structure. However, light-emitting element 47R and light-receiving element 46 may also have optical adjustment layers of different thicknesses. For example, it is preferred that the pixel electrodes 191 and 181 have a stacked structure of a reflective electrode and a transparent electrode overlying the reflective electrode, thereby making the thickness of the transparent electrode of light-emitting element 47R different from the thickness of the transparent electrode of light-receiving element 46, thereby achieving optical adjustment. Specifically, light-emitting element 47R preferably has a transparent electrode arranged such that the optical distance between the pair of electrodes is a distance that enhances red light, and light-receiving element 46 preferably has a transparent electrode arranged such that the optical distance between the pair of electrodes is a distance that enhances light of the desired wavelength. This allows light-emitting element 47R to efficiently extract red light, and light-receiving element 46 to detect light with high precision. Furthermore, light-emitting element 47G preferably has a buffer layer 192G used to optically adjust the optical distance between the pair of electrodes such that the optical distance between the pair of electrodes is a distance that enhances green light. Similarly, light emitting element 47B is preferably optically adjusted using buffer layer 192B so that the optical distance between the pair of electrodes becomes an optical distance that enhances blue light. Alternatively, optical adjustment layers (transparent electrodes) may be provided on each of light emitting element 47G and light emitting element 47B.

[0156] For example, the following structure can be cited: the common layer 112 includes a hole injection layer, the buffer layers 182, 192B, and 192G include hole transport layers, and the common layer 114 includes one or both of an electron injection layer and an electron transport layer.

[0157] The structure of the display device shown in FIG6B will be described in detail.

[0158] A light emitting element 47B shown in FIG6B has the same structure as that in FIG6A.

[0159] The light emitting element 47R includes the common layer 112, the buffer layer 192R, the light emitting layer 193R, and the common layer 114 in this order on the pixel electrode 191. The light emitting layer 193R contains a light emitting material that emits red light. The light emitting element 47R has a function of emitting red light.

[0160] Light-emitting element 47G and light-receiving element 46 each comprise, in this order, a common layer 112, a buffer layer 182, a light-emitting layer 193G, an active layer 183, and a common layer 114 on a pixel electrode. Light-emitting layer 193G comprises a material that emits green light. Active layer 183 comprises an organic compound that absorbs light with a shorter wavelength than green light (for example, blue emission). Active layer 183 preferably comprises an organic compound that absorbs less red to green light and absorbs light with a shorter wavelength than green light. This allows green light to be efficiently extracted from light-emitting element 47G, allowing light-receiving element 46 to accurately detect light with a shorter wavelength than green light.

[0161] The thicknesses of the pixel electrodes or buffer layers of light-emitting element 47G and light-receiving element 46 may also differ. Specifically, the optical distance between the pair of electrodes of light-emitting element 47G can be optically adjusted to enhance green light, and the optical distance between the pair of electrodes of light-receiving element 46 can be optically adjusted to enhance light of the desired wavelength. This allows light-emitting element 47G to efficiently extract green light, and light-receiving element 46 to detect light with high precision.

[0162] In the display device of this embodiment, an organic compound is used as the active layer 183 of the light-receiving element 46. The light-receiving element 46 can be manufactured by modifying at least part of the structure between a pair of electrodes in the light-emitting element 47. Therefore, the light-receiving element 46 can be built into the display portion of the display device. Furthermore, the light-receiving element can have the same structure as the light-emitting element that emits red or green light. As described above, by having at least part of the layers that make up the light-emitting element and the light-receiving element share the same structure, the manufacturing process of the display device can be reduced.

[0163] The structure of the display device shown in FIG. 7A will be described in detail.

[0164] The display device shown in FIG. 7A differs from the display device shown in FIG. 6A in that the light-emitting element 47R and the light-receiving element 46 do not include the buffer layer 182 and the light-emitting layer 193R is located on the active layer 183 .

[0165] There is no limitation on the stacking order of the active layer 183 and the light-emitting layer 193R. The light-emitting layer 193R may be provided on the active layer 183, or the active layer 183 may be provided on the light-emitting layer 193R.

[0166] For example, a hole transport layer can be used as buffer layers 192B and 192G. Light-emitting element 47R and light-receiving element 46 do not necessarily need to include a hole transport layer. Similarly, a layer (e.g., a hole injection layer, a hole transport layer, an electron transport layer, an electron injection layer, a hole barrier layer, an electron barrier layer, etc.) may be provided only in one of light-emitting elements 47R, 47G, 47B and light-receiving element 46 and not in the other elements.

[0167] The structure of the display device shown in FIG7B will be described in detail.

[0168] The display device shown in FIG. 7B differs from the display device shown in FIG. 6A in that a buffer layer 182 is included between the active layer 183 and the light-emitting layer 193R.

[0169] The light-emitting layer 193R and the active layer 183 may be in contact with each other, or a layer may be interposed between the light-emitting layer 193R and the active layer 183 .

[0170] By providing a buffer layer between the active layer 183 and the light-emitting layer 193R, the transfer of excitation energy from the light-emitting layer 193R to the active layer 183 can be suppressed. Furthermore, the buffer layer can be used to adjust the optical path length (cavity length) of the microcavity structure. Therefore, the light-emitting element 47R, which includes the buffer layer between the active layer 183 and the light-emitting layer 193R, can achieve high luminous efficiency.

[0171] For example, a structure can be described as follows: common layer 112 includes a hole injection layer, buffer layers 182, 192B, and 192G include hole transport layers, and common layer 114 includes one or both of an electron injection layer and an electron transport layer. Furthermore, common layer 112 may also include a hole transport layer. In other words, each of the light-emitting element and the light-receiving element may include both the hole transport layer included in common layer 112 and the hole transport layer included in the buffer layer.

[0172] Hereinafter, the structure of a display device according to one embodiment of the present invention will be described using FIG. 8 and FIG. 9 .

[0173] [Display device 10A] Fig. 8A is a cross-sectional view of a display device 10A. The display device 10A adopts the structure of Fig. 3B described in Structural Example 1. The details of each layer can be found in the description of Structural Example 1.

[0174] Display device 10A includes a light-receiving element 110, a light-emitting element 190B, and a light-emitting element 190G. Light-receiving element 110 detects light 22. The wavelength of light 22 detected by light-receiving element 110 is not particularly limited; for example, visible light, infrared light, or both may be detected. Light-emitting element 190B emits blue light 21B. Light-emitting element 190G emits green light 21G.

[0175] The light-emitting element 190B includes a pixel electrode 191 , a common layer 112 , a light-emitting layer 193B, a common layer 114 , and a common electrode 115 .

[0176] The light-emitting element 190G includes a pixel electrode 191 , a common layer 112 , a light-emitting layer 193G, a light-emitting layer 193B, a common layer 114 , and a common electrode 115 .

[0177] The light-receiving element 110 includes a pixel electrode 181 , a common layer 112 , an active layer 183 , a light-emitting layer 193B, a common layer 114 , and a common electrode 115 .

[0178] The pixel electrode 181 and the pixel electrode 191 are located on the insulating layer 214. The pixel electrode 181 and the pixel electrode 191 can be formed using the same material and the same process.

[0179] Common layer 112 is located on pixel electrode 181 and pixel electrode 191. Common layer 112 is a layer shared by light-receiving element 110, light-emitting element 190B, and light-emitting element 190G. Common layer 112 may be, for example, a hole injection layer or a hole transport layer, or both.

[0180] Active layer 183 overlaps with pixel electrode 181 via common layer 112. Light-emitting layer 193G overlaps with pixel electrode 191 via common layer 112. Light-emitting layer 193B overlaps with pixel electrode 181 via common layer 112 and active layer 183. Light-emitting layer 193B overlaps with pixel electrode 191 included in light-emitting element 190G via common layer 112 and light-emitting layer 193G. Light-emitting layer 193B overlaps with pixel electrode 191 included in light-emitting element 190B via common layer 112.

[0181] The common layer 114 is located on the light-emitting layer 193B. The common layer 114 is a layer shared by the light-receiving element 110, the light-emitting element 190B, and the light-emitting element 190G. The common layer 114 may be, for example, an electron injection layer or an electron transport layer, or both.

[0182] The common electrode 115 has a portion that overlaps with the pixel electrode 181 via the common layer 112, active layer 183, light-emitting layer 193B, and common layer 114. Furthermore, the common electrode 115 has a portion that overlaps with the pixel electrode 191 included in the light-emitting element 190G via the common layer 112, light-emitting layer 193G, light-emitting layer 193B, and common layer 114. The common electrode 115 has a portion that overlaps with the pixel electrode 191 included in the light-emitting element 190B via the common layer 112, light-emitting layer 193B, and common layer 114. The common electrode 115 is a layer shared by the light-receiving element 110, the light-emitting element 190B, and the light-emitting element 190G.

[0183] In the display device of this embodiment, an organic compound is used for the active layer 183 of the light-receiving element 110. The light-receiving element 110 can be manufactured by simply changing at least part of the structure between a pair of electrodes of the light-emitting element 190 (EL element). In other words, the light-emitting element 190 and the light-receiving element 110 can be formed on the same substrate. Furthermore, the light-receiving element 110 can be formed simultaneously with the light-emitting element 190. Therefore, the light-receiving element 110 can be incorporated into the display portion of the display device without significantly increasing the number of manufacturing processes.

[0184] In the display device 10A, only the active layer 183 of the light-receiving element 110 and the light-emitting layer 193G of the light-emitting element 190G are formed separately, while other layers can be shared by both the light-receiving element 110 and the light-emitting element 190G. However, the structures of the light-receiving element 110 and the light-emitting element 190G are not limited to this. In addition to the active layer 183 and the light-emitting layer 193G, the light-receiving element 110 and the light-emitting element 190G can also have other separately formed layers. The light-receiving element 110 and the light-emitting element 190G preferably share one or more layers (common layers). This allows the light-receiving element 110 to be incorporated into the display device without significantly increasing the manufacturing process.

[0185] In display device 10A shown in FIG8A , light-emitting layer 193B, which emits blue light, is provided not only in light-emitting element 190B, which emits blue light, but also in light-emitting element 190G and light-receiving element 110. In light-emitting element 190G and light-receiving element 110, light-emitting layer 193B serves as a carrier transport layer. By providing light-emitting layer 193B in light-emitting elements and light-receiving elements that emit light of different colors, the effects of misalignment in the pattern of light-emitting layer 193B can be reduced, thereby improving the yield rate during display device manufacturing.

[0186] The display device 10A includes a light receiving element 110 , a light emitting element 190B, a light emitting element 190G, a transistor 41 , a transistor 42 , and the like between a pair of substrates (a substrate 151 and a substrate 152 ).

[0187] In the light-receiving element 110, the common layer 112, active layer 183, and common layer 114 located between the pixel electrode 181 and the common electrode 115 can each be referred to as an organic layer (a layer containing an organic compound). The pixel electrode 181 preferably reflects visible light. The ends of the pixel electrode 181 are covered by the partition wall 216. The common electrode 115 preferably transmits visible light.

[0188] Light-receiving element 110 has the function of detecting light. Specifically, light-receiving element 110 is a photoelectric conversion element that receives light 22 incident from outside display device 10A and converts it into an electrical signal. Light 22 can also be considered light reflected from light-emitting element 190 by an object. Alternatively, light 22 can enter light-receiving element 110 through a lens (described later).

[0189] The substrate 151 side of the substrate 152 is preferably provided with a light shielding layer BM. The light shielding layer BM has openings formed at positions overlapping the light receiving element 110 and the light emitting element 190. The light shielding layer BM can control the range of light detection by the light receiving element 110.

[0190] Here, light-receiving element 110 detects light from light-emitting element 190 that is reflected by an object. However, light from light-emitting element 190 may sometimes be reflected within display device 10A and enter light-receiving element 110 without passing through the object. A light-shielding layer BM can reduce the negative effects of this stray light. For example, without a light-shielding layer BM, light 23a emitted by light-emitting element 190 may sometimes be reflected by substrate 152, causing reflected light 23b to enter light-receiving element 110. Providing a light-shielding layer BM prevents reflected light 23b from entering light-receiving element 110. This reduces noise and improves the sensitivity of the sensor using light-receiving element 110.

[0191] In the light-emitting element 190, the common layer 112, the light-emitting layer 193, and the common layer 114, respectively located between the pixel electrode 191 and the common electrode 115, can be referred to as EL layers. The pixel electrode 191 preferably reflects visible light. The end of the pixel electrode 191 is covered by a partition wall 216. The pixel electrode 181 and the pixel electrode 191 are electrically insulated from each other (also referred to as electrically separated) by the partition wall 216. The common electrode 115 preferably transmits visible light.

[0192] The light-emitting element 190B is an electroluminescent element that emits blue light 21B toward the substrate 152 when a voltage is applied between the pixel electrode 191 and the common electrode 115 .

[0193] The light emitting element 190G is an electroluminescent element that emits green light 21G toward the substrate 152 when a voltage is applied between the pixel electrode 191 and the common electrode 115 .

[0194] The pixel electrode 181 is electrically connected to the source or drain of the transistor 41 through an opening provided in the insulating layer 214. The end of the pixel electrode 181 is covered by the partition wall 216.

[0195] The pixel electrode 191 is electrically connected to the source or drain of the transistor 42 via an opening provided in the insulating layer 214. The end of the pixel electrode 191 is covered by the partition wall 216. The transistor 42 has a function of controlling the driving of the light emitting element 190.

[0196] The transistor 41 and the transistor 42 are formed on the same layer (the substrate 151 in FIG. 8A ) so as to be in contact with the same layer.

[0197] At least a portion of the circuit electrically connected to the light-receiving element 110 is preferably formed using the same materials and processes as the circuit electrically connected to the light-emitting element 190. This reduces the thickness of the display device and simplifies the manufacturing process compared to forming the two circuits separately.

[0198] The light-receiving element 110 and the light-emitting element 190 are each preferably covered with a protective layer 195. In FIG8A , the protective layer 195 is provided on and in contact with the common electrode 115. The provision of the protective layer 195 can prevent impurities such as water from entering the light-receiving element 110 and the light-emitting element 190, thereby improving the reliability of the light-receiving element 110 and the light-emitting element 190. Furthermore, the protective layer 195 and the substrate 152 can be bonded together using an adhesive layer 142.

[0199] [Display device 10B] 8B is a cross-sectional view of a display device 10B. The display device 10B employs the structure described in Structural Example 2. In the following description of the display device, description of the same structure as that of the previously described display device may be omitted.

[0200] The display device 10B includes a light receiving element 110, a light emitting element 190R, and a light emitting element 190G. The light receiving element 110 detects light 22. The light emitting element 190R emits red light 21R. The light emitting element 190G emits green light 21G.

[0201] Light-emitting element 190R and light-emitting element 190G have the same structure. Specifically, light-emitting element 190R and light-emitting element 190G include pixel electrode 191, common layer 112, light-emitting layer 193, common layer 114, and common electrode 115. Light-emitting layer 193 can have a single-layer structure or a stacked-layer structure. For example, light-emitting layer 193 can have a structure including a light-emitting layer 193R that emits red light and a light-emitting layer 193G that emits green light, as shown in FIG4A , or a structure including a light-emitting layer 193Y that emits yellow light, as shown in FIG5A .

[0202] A red color layer CFR and a green color layer CFG are provided on the substrate 151 side of the substrate 152. Light emitted by the light-emitting element 190R passes through the color layer CFR and is extracted from the display device 10B as red light. Furthermore, light emitted by the light-emitting element 190G passes through the color layer CFG and is extracted from the display device 10B as green light.

[0203] The light receiving element 110 includes a pixel electrode 181 , a common layer 112 , an active layer 183 , a common layer 114 , and a common electrode 115 .

[0204] In the display device 10B, only the active layer 183 of the light-receiving element 110 and the light-emitting layer 193 of the light-emitting elements 190G and 190R are formed separately, while other layers can be shared by the light-receiving element 110 and the light-emitting elements 190G and 190R. However, the structures of the light-receiving element 110 and the light-emitting elements 190G and 190R are not limited to this. In addition to the active layer 183 and the light-emitting layer 193, the light-receiving element 110 and the light-emitting elements 190G and 190R can also have other separately formed layers. The light-receiving element 110 and the light-emitting elements 190G and 190R preferably share one or more layers (common layers). This allows the light-receiving element 110 to be incorporated into the display device without significantly increasing the manufacturing process.

[0205] [Display device 10C] Fig. 8C is a cross-sectional view of a display device 10C. As the display device 10C, the structure of Fig. 6A described in Structural Example 3 is used.

[0206] The display device 10C includes a light receiving element 110, a light emitting element 190R, and a light emitting element 190G. The light receiving element 110 detects light 22. The light emitting element 190R emits red light 21R. The light emitting element 190G emits green light 21G.

[0207] Light-emitting element 190R and light-receiving element 110 have the same structure. Specifically, light-emitting element 190R and light-receiving element 110 include a pixel electrode, a common layer 112, a light-emitting layer 193R, an active layer 183, a common layer 114, and a common electrode 115. Note that although light-emitting layer 193R and active layer 183 are shown as a single layer in FIG. 8C and other figures, light-emitting layer 193R and active layer 183 are separate layers.

[0208] The light-emitting element 190G includes a pixel electrode 191 , a common layer 112 , a light-emitting layer 193G, a common layer 114 , and a common electrode 115 .

[0209] In the display device 10C, the light-receiving element 110 and the light-emitting element 190R have the same structure as the light-emitting element 190G, except that the active layer 183 and the light-emitting layer 193R of the light-receiving element 110 and the light-emitting layer 193G of the light-emitting element 190G are formed separately. Note that the structures of the light-receiving element 110 and the light-emitting elements 190G and 190R are not limited to these.

[0210] [Display device 10D] FIG9A shows a cross-sectional view of a display device 10D.

[0211] The display device 10D differs from the display device 10A in that the protective layer 195 is not included but the lens 149 is included.

[0212] The display device of this embodiment does not need to have a protective layer on the light-receiving element 110 and the light-emitting element 190. In FIG9A, the common electrode 115 and the substrate 152 are bonded together using an adhesive layer 142.

[0213] The display device of this embodiment may also include a lens 149. The lens 149 is provided at a position overlapping the light receiving element 110. In the display device 10D, the lens 149 is provided in contact with the substrate 152. The lens 149 included in the display device 10D has a convex surface on the substrate 151 side.

[0214] When both the light shielding layer BM and the lens 149 are formed on the same surface of the substrate 152, there is no restriction on the order in which they are formed. Although FIG9A shows an example in which the lens 149 is formed first, the light shielding layer BM may also be formed first. In FIG9A , the end of the lens 149 is covered by the light shielding layer BM.

[0215] Display device 10D employs a structure in which light 22 passes through lens 149 and enters light-receiving element 110. Compared to a case without lens 149, the provision of lens 149 reduces the imaging range of light-receiving element 110, thereby preventing overlap with the imaging range of adjacent light-receiving elements 110. This allows for the capture of clear images with minimal blur. Furthermore, when the imaging range of light-receiving element 110 remains the same, the provision of lens 149 increases the size of the pinhole (equivalent to the size of the opening of light-shielding layer BM overlapping with light-receiving element 110 in FIG9A ) compared to a case without lens 149. Thus, the presence of lens 149 increases the amount of light entering light-receiving element 110.

[0216] Furthermore, a lens 149 having a convex surface can be provided on the substrate 152 side so as to contact the top surface of the protective layer 195. Alternatively, a lens array can be provided on the display surface side of the substrate 152 (the side opposite to the substrate 151 surface). The lenses of the lens array are provided at positions overlapping the light-receiving element 110. Preferably, a light-shielding layer BM is provided on the substrate 151 side surface of the substrate 152.

[0217] As a method for forming lenses for the display device of this embodiment, lenses such as microlenses can be directly formed on a substrate or a light-receiving element, or a lens array such as a separately manufactured microlens array can be bonded to the substrate.

[0218] [Display device 10E] FIG9B shows a cross-sectional view of the display device 10E.

[0219] The display device 10E is different from the display device 10B in that the display device 10E does not include the substrates 151 and 152 but includes a substrate 153 , a substrate 154 , an adhesive layer 155 and an insulating layer 212 .

[0220] The substrate 153 and the insulating layer 212 are bonded together by the adhesive layer 155 . The substrate 154 and the protective layer 195 are bonded together by the adhesive layer 142 .

[0221] The display device 10E is formed by transferring the insulating layer 212, transistors 41 and 42, light-receiving element 110, and light-emitting element 190 formed on a manufacturing substrate onto a substrate 153. Substrates 153 and 154 are preferably flexible. This improves the flexibility of the display device 10E. For example, substrates 153 and 154 are preferably made of resin. Furthermore, the display device of this embodiment may also use a highly optically isotropic film as the substrate.

[0222] [Display device 10F] FIG9C shows a cross-sectional view of the display device 10F.

[0223] The display device 10F differs from the display device 10C in that the partition wall 216 is not included but the partition wall 217 is included.

[0224] The partition wall 217 preferably absorbs light emitted by the light-emitting element. For example, a black matrix can be formed using a resin material containing a pigment or dye. Furthermore, by using a brown photoresist material, the partition wall 217 can be formed from a colored insulating layer.

[0225] Light emitted by light-emitting element 190 may be reflected by substrate 152 and partition wall 217, causing the reflected light to enter light-receiving element 110. Furthermore, light emitted by light-emitting element 190 may also pass through partition wall 217 and be reflected by transistors, wiring, etc., causing the reflected light to enter light-receiving element 110. Light absorption by partition wall 217 prevents this reflected light from entering light-receiving element 110. This reduces noise and improves the sensitivity of the sensor using light-receiving element 110.

[0226] Partition wall 217 preferably absorbs at least the wavelength of light detected by light-receiving element 110. For example, when light-receiving element 110 detects green light 21G emitted by light-emitting element 190G, partition wall 217 preferably absorbs at least the green light. For example, if partition wall 217 includes a red filter, it can absorb green light, thereby preventing reflected light from entering light-receiving element 110.

[0227] Furthermore, a light-absorbing colored layer is provided in contact with one or both of the top and side surfaces of the light-transmitting partition wall. The colored layer preferably absorbs light emitted by the light-emitting element. For example, a black matrix can be formed using a resin material containing a pigment or dye. Furthermore, by using a brown photoresist material, a colored insulating layer can be used to form a colored layer.

[0228] The colored layer preferably absorbs at least the wavelength of light detected by light-receiving element 110. For example, when light-receiving element 110 detects green light 21G emitted by light-emitting element 190G, the colored layer preferably absorbs at least the green light. For example, if the colored layer includes a red filter, it can absorb the green light, thereby preventing reflected light from entering light-receiving element 110.

[0229] By absorbing stray light generated within the display device 10F with the colored layer, the amount of stray light incident on the light-receiving element 110 can be reduced. This reduces noise and improves the sensitivity of the sensor using the light-receiving element 110.

[0230] In the display device of this embodiment, the colored layer is arranged between the light-receiving element 110 and the light-emitting element 190. This can suppress stray light from the light-emitting element 190 from entering the light-receiving element 110.

[0231] The following describes a more detailed structure of a display device according to one embodiment of the present invention with reference to FIG10 to FIG14. Note that FIG10 to FIG14 primarily illustrate a display device employing the structure of FIG3B described in Structural Example 1. However, a display device according to one embodiment of the present invention may also employ the structures described in Structural Example 2 or Structural Example 3.

[0232] [Display device 100A] FIG. 10 shows a perspective view of the display device 100A, and FIG. 11 shows a cross-sectional view of the display device 100A.

[0233] The display device 100A has a structure in which a substrate 152 and a substrate 151 are bonded together. In FIG10 , the substrate 152 is indicated by a dotted line.

[0234] Display device 100A includes a display portion 162, circuits 164, and wiring 165. FIG10 shows an example in which an IC (Integrated Circuit) 173 and an FPC 172 are mounted on display device 100A. Therefore, the structure shown in FIG10 can also be referred to as a display module including display device 100A, an IC, and an FPC.

[0235] As the circuit 164, for example, a scan line driver circuit can be used.

[0236] The wiring 165 has a function of supplying signals and power to the display portion 162 and the circuit 164. The signals and power are input to the wiring 165 from the outside via the FPC 172 or the IC 173.

[0237] FIG10 illustrates an example of IC 173 disposed on substrate 151 using a COG (Chip on Glass) or COF (Chip on Film) method. IC 173 can include, for example, a scan line driver circuit or a signal line driver circuit. Note that the display device 100A and the display module do not necessarily require ICs. Alternatively, the IC can be mounted on an FPC using a COF method or the like.

[0238] 11 illustrates an example of a cross section of a portion of a region including the FPC 172 , a portion of a region including the circuit 164 , a portion of a region including the display portion 162 , and a portion of a region including an end portion of the display device 100A shown in FIG. 10 .

[0239] The display device 100A shown in FIG11 includes a transistor 201 , a transistor 205 , a transistor 206 , a transistor 207 , a light emitting element 190B, a light emitting element 190G, a light receiving element 110 , and the like between substrates 151 and 152 .

[0240] Substrate 152 and insulating layer 214 are bonded together via adhesive layer 142. A solid sealing structure or a hollow sealing structure can be used to seal light-emitting element 190 and light-receiving element 110. In Figure 11, space 143 surrounded by substrate 152, adhesive layer 142, and insulating layer 214 is filled with an inert gas (nitrogen, argon, etc.), employing a hollow sealing structure. Adhesive layer 142 may also overlap light-emitting element 190. Furthermore, space 143 surrounded by substrate 152, adhesive layer 142, and insulating layer 214 may be filled with a resin different from that used in adhesive layer 142.

[0241] Light-emitting element 190B has a stacked structure comprising, in order from the insulating layer 214 side, a pixel electrode 191B, a common layer 112, a light-emitting layer 193B, a common layer 114, and a common electrode 115. Pixel electrode 191B is connected to conductive layer 222b, which is included in transistor 206, through an opening formed in insulating layer 214. Transistor 206 controls the driving of light-emitting element 190B. A partition wall 216 covers the end of pixel electrode 191B. Pixel electrode 191B is made of a material that reflects visible light, while common electrode 115 is made of a material that transmits visible light.

[0242] Light-emitting element 190G has a stacked structure comprising, in order from the insulating layer 214 side, a pixel electrode 191G, a common layer 112, a light-emitting layer 193G, a light-emitting layer 193B, a common layer 114, and a common electrode 115. Pixel electrode 191G is connected to conductive layer 222b, which is included in transistor 207, through an opening formed in insulating layer 214. Transistor 207 controls the driving of light-emitting element 190G. A partition wall 216 covers the end of pixel electrode 191G. Pixel electrode 191G comprises a material that reflects visible light.

[0243] The light-receiving element 110 has a stacked structure in which a pixel electrode 181, a common layer 112, an active layer 183, a light-emitting layer 193B, a common layer 114, and a common electrode 115 are stacked in this order from the insulating layer 214 side. The pixel electrode 181 is electrically connected to the conductive layer 222b included in the transistor 205 through an opening formed in the insulating layer 214. The partition wall 216 covers the end of the pixel electrode 181. The pixel electrode 181 is made of a material that reflects visible light.

[0244] The light emitting element 190 emits light toward the substrate 152. The light receiving element 110 receives light through the substrate 152 and the space 143. The substrate 152 is preferably made of a material that is highly transparent to visible light.

[0245] Pixel electrodes 181, 191B, and 191G can be formed using the same material and process. Common layers 112, 114, and common electrodes 115 are used for both the light-receiving element 110 and the light-emitting elements 190 of each color. The light-receiving element 110 has a structure that adds an active layer 183 to the structure of the light-emitting element 190B. Furthermore, other than the active layer 183 and the light-emitting layer 193G, the light-receiving element 110 and the light-emitting element 190G can share other layers. This allows the light-receiving element 110 to be incorporated into the display device 100A without significantly increasing the number of manufacturing processes.

[0246] A light-shielding layer BM is provided on the surface of substrate 152 on the substrate 151 side. The light-shielding layer BM has openings at locations overlapping the light-receiving element 110 and the light-emitting element 190. The light-shielding layer BM controls the range of light detection by the light-receiving element 110. Furthermore, the light-shielding layer BM prevents light from the light-emitting element 190 from directly entering the light-receiving element 110 without passing through an object. This allows for a sensor with low noise and high sensitivity.

[0247] The transistor 201, the transistor 205, the transistor 206, and the transistor 207 are all disposed on the substrate 151. These transistors can be formed using the same material and the same process.

[0248] On substrate 151, insulating layer 211, insulating layer 213, insulating layer 215, and insulating layer 214 are sequentially provided. A portion of insulating layer 211 serves as a gate insulating layer for each transistor. A portion of insulating layer 213 serves as a gate insulating layer for each transistor. Insulating layer 215 is provided to cover the transistors. Insulating layer 214 is provided to cover the transistors and serves as a planarization layer. There are no particular restrictions on the number of gate insulating layers or insulating layers covering the transistors; they can be one or two or more.

[0249] Preferably, at least one of the insulating layers covering the transistor is made of a material that is less susceptible to diffusion of impurities such as water or hydrogen. This allows the insulating layer to function as a barrier layer. This structure effectively prevents impurities from diffusing into the transistor from the outside, thereby improving the reliability of the display device.

[0250] Inorganic insulating films are preferably used as insulating layer 211, insulating layer 213, and insulating layer 215. Examples of such inorganic insulating films include silicon nitride films, silicon oxynitride films, silicon oxide films, silicon nitride oxide films, aluminum oxide films, and aluminum nitride films. Other examples include hafnium oxide films, yttrium oxide films, zirconium oxide films, gallium oxide films, tantalum oxide films, magnesium oxide films, lanthanum oxide films, cerium oxide films, and neodymium oxide films. Furthermore, two or more of the above insulating films may be stacked.

[0251] Here, the barrier properties of organic insulating films are often lower than those of inorganic insulating films. Therefore, the organic insulating film preferably includes openings near the ends of the display device 100A. This can suppress the intrusion of impurities from the ends of the display device 100A through the organic insulating film. Alternatively, the organic insulating film can be formed so that its ends are located inward of the ends of the display device 100A to protect the organic insulating film from being exposed at the ends of the display device 100A.

[0252] The insulating layer 214 used as the planarization layer is preferably an organic insulating film. Examples of materials that can be used for the organic insulating film include acrylic resin, polyimide resin, epoxy resin, polyamide resin, polyimide amide resin, siloxane resin, benzocyclobutene resin, phenolic resin, and precursors of these resins.

[0253] In region 228 shown in FIG11 , an opening is formed in insulating layer 214. This prevents impurities from penetrating insulating layer 214 from the outside and entering display portion 162, even when an organic insulating film is used as insulating layer 214. This improves the reliability of display device 100A.

[0254] Transistors 201, 205, 206, and 207 include a conductive layer 221 serving as a gate; an insulating layer 211 serving as a gate insulator; conductive layers 222a and 222b serving as a source and drain; a semiconductor layer 231; an insulating layer 213 serving as a gate insulator; and a conductive layer 223 serving as a gate. Multiple layers formed by processing the same conductive film are shaded identically. Insulating layer 211 is located between conductive layer 221 and semiconductor layer 231. Insulating layer 213 is located between conductive layer 223 and semiconductor layer 231.

[0255] There are no particular limitations on the transistor structure included in the display device of this embodiment. For example, planar transistors, staggered transistors, or inversely staggered transistors may be used. Furthermore, the transistors may have a top-gate structure or a bottom-gate structure. Alternatively, gates may be provided above and below the semiconductor layer forming the channel.

[0256] Transistors 201, 205, 206, and 207 employ a structure in which two gates sandwich the semiconductor layer forming the channel. Alternatively, the two gates can be connected and driven by supplying the same signal to both gates. Alternatively, the threshold voltage of the transistor can be controlled by applying a potential for controlling the threshold voltage to one of the two gates and a potential for driving the other.

[0257] There are no particular restrictions on the crystallinity of the semiconductor material used for the transistor. Amorphous semiconductors or crystalline semiconductors (microcrystalline semiconductors, polycrystalline semiconductors, single crystal semiconductors, or semiconductors partially containing crystalline regions) can be used. Using a crystalline semiconductor is preferred because it can suppress degradation of the transistor's characteristics.

[0258] The semiconductor layer of the transistor is preferably made of a metal oxide (oxide semiconductor). Alternatively, the semiconductor layer of the transistor may include silicon. Examples of silicon include amorphous silicon and crystalline silicon (such as low-temperature polysilicon and single-crystal silicon).

[0259] For example, the semiconductor layer preferably includes indium, M (M is one or more selected from gallium, aluminum, silicon, boron, yttrium, tin, copper, vanadium, beryllium, titanium, iron, nickel, germanium, zirconium, molybdenum, lanthanum, cerium, neodymium, hafnium, tantalum, tungsten, or magnesium), and zinc. In particular, M is preferably one or more selected from aluminum, gallium, yttrium, or tin.

[0260] In particular, as the semiconductor layer, it is preferable to use an oxide (IGZO) containing indium (In), gallium (Ga), and zinc (Zn).

[0261] When an In-M-Zn oxide is used in the semiconductor layer, the atomic number ratio of In in the In-M-Zn oxide is preferably greater than or equal to the atomic number ratio of M. Examples of the atomic ratio of the metal elements in the In-M-Zn oxide include compositions of In:M:Zn = 1:1:1 or approximately thereabouts, compositions of In:M:Zn = 1:1:1.2 or approximately thereabouts, compositions of In:M:Zn = 2:1:3 or approximately thereabouts, compositions of In:M:Zn = 3:1:2 or approximately thereabouts, compositions of In:M:Zn = 4:2:3 or approximately thereabouts, compositions of In:M:Zn = 4:2:4.1 or approximately thereabouts, compositions of In:M:Zn = 5:1:3 or approximately thereabouts, compositions of In:M:Zn = 5:1:6 or approximately thereabouts, compositions of In:M:Zn = 5:1:7 or approximately thereabouts, compositions of In:M:Zn = 5:1:8 or approximately thereabouts, compositions of In:M:Zn = 6:1:6 or approximately thereabouts, and compositions of In:M:Zn = 5:2:5 or approximately thereabouts. Approximate compositions include compositions within a range of ±30% of the desired atomic ratio.

[0262] For example, a description of a composition having an atomic ratio of In:Ga:Zn = 4:2:3 or thereabouts includes the following: when the atomic ratio of In is 4, the atomic ratio of Ga is 1 or more and 3 or less, and the atomic ratio of Zn is 2 or more and 4 or less. Furthermore, a description of a composition having an atomic ratio of In:Ga:Zn = 5:1:6 or thereabouts includes the following: when the atomic ratio of In is 5, the atomic ratio of Ga is greater than 0.1 and 2 or less, and the atomic ratio of Zn is 5 or more and 7 or less. Furthermore, a description of a composition having an atomic ratio of In:Ga:Zn = 1:1:1 or thereabouts includes the following: when the atomic ratio of In is 1, the atomic ratio of Ga is greater than 0.1 and 2 or less, and the atomic ratio of Zn is greater than 0.1 and 2 or less.

[0263] The transistors included in circuit 164 and the transistors included in display portion 162 may have the same structure or different structures. The multiple transistors included in circuit 164 may have the same structure or two or more different structures. Similarly, the multiple transistors included in display portion 162 may have the same structure or two or more different structures.

[0264] Connecting portion 204 is provided in a region where substrates 151 and 152 do not overlap. In connecting portion 204, wiring 165 is electrically connected to FPC 172 through conductive layer 166 and connecting layer 242. Conductive layer 166, which is formed by processing the same conductive film as pixel electrode 191, is exposed on the top surface of connecting portion 204. Therefore, connecting portion 204 and FPC 172 can be electrically connected through connecting layer 242.

[0265] Furthermore, various optical components may be disposed on the outside of substrate 152. Examples of these optical components include polarizing plates, phase difference plates, light diffusion layers (such as diffusion films), antireflection layers, and condensing films. Furthermore, an antistatic film to prevent dust from adhering, a water-repellent film to prevent staining, a hard coat to prevent damage during use, and a buffer layer may also be disposed on the outside of substrate 152.

[0266] Glass, quartz, ceramic, sapphire, resin, etc. can be used for the substrates 151 and 152. By using flexible materials for the substrates 151 and 152, the flexibility of the display device can be improved.

[0267] The adhesive layer can be made from a variety of curing adhesives, including UV-curing adhesives, reaction-curing adhesives, thermosetting adhesives, and anaerobic adhesives. Examples of these adhesives include epoxy resins, acrylic resins, silicone resins, phenolic resins, polyimide resins, imide resins, PVC (polyvinyl chloride) resins, PVB (polyvinyl butyral) resins, and EVA (ethylene vinyl acetate) resins. In particular, materials with low moisture permeability, such as epoxy resins, are preferred. Alternatively, two-component mixed resins can be used. Alternatively, adhesive sheets can be used.

[0268] As the connection layer 242, anisotropic conductive film (ACF: Anisotropic Conductive Film), anisotropic conductive paste (ACP: Anisotropic Conductive Paste), etc. can be used.

[0269] Light-emitting element 190 has a top-emission structure, a bottom-emission structure, or a dual-emission structure. A conductive film that transmits visible light is used as the electrode on the light-extraction side. Furthermore, a conductive film that reflects visible light is preferably used as the electrode on the side that does not extract light.

[0270] Light-emitting element 190 includes at least a light-emitting layer 193. In addition to light-emitting layer 193, light-emitting element 190 may also include layers containing materials with high hole-injection properties, materials with high hole-transport properties, hole-blocking materials, materials with high electron-transport properties, materials with high electron-injection properties, or bipolar materials (materials with high electron-transport properties and hole-transport properties). For example, common layer 112 preferably includes one or both of a hole-injection layer and a hole-transport layer. For example, common layer 114 preferably includes one or both of an electron-transport layer and an electron-injection layer.

[0271] Common layer 112, light-emitting layer 193, and common layer 114 can be formed using low-molecular-weight compounds or high-molecular-weight compounds, and may also include inorganic compounds. The layers constituting common layer 112, light-emitting layer 193, and common layer 114 can be formed using methods such as evaporation (including vacuum evaporation), transfer, printing, inkjet, and coating.

[0272] Light-emitting layer 193 is a layer containing a light-emitting substance. Light-emitting layer 193 can contain one or more light-emitting substances. Suitable light-emitting substances include those that emit light in colors such as blue, purple, blue-purple, green, yellow-green, yellow, orange, and red. Alternatively, substances that emit near-infrared light can be used.

[0273] The active layer 183 of the light-receiving element 110 includes a semiconductor. Examples of such semiconductors include inorganic semiconductors such as silicon and organic semiconductors including organic compounds. This embodiment shows an example of using an organic semiconductor as the semiconductor included in the active layer. Using an organic semiconductor is preferred because it allows the light-emitting layer 193 of the light-emitting element 190 and the active layer 183 of the light-receiving element 110 to be formed using the same method (e.g., vacuum deposition), allowing for the use of shared manufacturing equipment.

[0274] Examples of n-type semiconductor materials included in the active layer 183 include organic semiconductor materials with electron-accepting properties, such as fullerene (e.g., C60, C70, etc.) or its derivatives. Furthermore, examples of p-type semiconductor materials included in the active layer 183 include organic semiconductor materials with electron-donating properties, such as copper(II) phthalocyanine (CuPc) or tetraphenyldibenzoperiflanthene (DBP).

[0275] For example, it is preferable to co-evaporate an n-type semiconductor and a p-type semiconductor to form the active layer 183 .

[0276] Examples of materials that can be used for conductive layers such as gates, sources, and drains of transistors and various wiring and electrodes constituting display devices include metals such as aluminum, titanium, chromium, nickel, copper, yttrium, zirconium, molybdenum, silver, tantalum, or tungsten, or alloys primarily composed of these metals. Films containing these materials can be used in the form of single layers or stacked layers.

[0277] In addition, as a light-transmitting conductive material, conductive oxides such as indium oxide, indium tin oxide, indium zinc oxide, zinc oxide, and zinc oxide containing gallium, or graphene can be used. Alternatively, metal materials such as gold, silver, platinum, magnesium, nickel, tungsten, chromium, molybdenum, iron, cobalt, copper, palladium, or titanium, or alloy materials containing such metal materials, can be used. Alternatively, nitrides of such metal materials (e.g., titanium nitride) can also be used. Furthermore, when using metal materials or alloy materials (or their nitrides), it is preferably formed thin enough to be light-transmitting. Furthermore, the above-mentioned laminated films can be used as conductive layers. For example, a laminated film of an alloy of silver and magnesium and indium tin oxide is preferred because conductivity can be improved. The above-mentioned materials can also be used in conductive layers constituting various wiring and electrodes of a display device, and in conductive layers included in display elements (conductive layers used as pixel electrodes and common electrodes).

[0278] Examples of insulating materials that can be used for each insulating layer include resins such as acrylic resins and epoxy resins, and inorganic insulating materials such as silicon oxide, silicon oxynitride, silicon nitride oxide, silicon nitride, and aluminum oxide.

[0279] [Display device 100B] FIG12A shows a cross-sectional view of a display device 100B.

[0280] The display device 100B differs from the display device 100A mainly in that it includes a lens 149 and a protective layer 195. Detailed description of the same structure as the display device 100A will be omitted.

[0281] By providing the protective layer 195 covering the light receiving element 110 and the light emitting element 190 , it is possible to suppress the mixing of impurities such as water into the light receiving element 110 and the light emitting element 190 , thereby improving the reliability of the light receiving element 110 and the light emitting element 190 .

[0282] In regions 228 near the ends of the display device 100B, the insulating layer 215 and the protective layer 195 are preferably in contact with each other through the openings in the insulating layer 214. In particular, it is particularly preferred that the inorganic insulating film included in the insulating layer 215 and the inorganic insulating film included in the protective layer 195 are in contact with each other. This can prevent impurities from entering the display portion 162 from outside through the organic insulating film. Consequently, the reliability of the display device 100B can be improved.

[0283] 12B shows an example in which the protective layer 195 has a three-layer structure. In FIG12B, the protective layer 195 includes an inorganic insulating layer 195a on the common electrode 115, an organic insulating layer 195b on the inorganic insulating layer 195a, and an inorganic insulating layer 195c on the organic insulating layer 195b.

[0284] The ends of inorganic insulating layer 195a and inorganic insulating layer 195c extend outside the ends of organic insulating layer 195b and are in contact with each other. Furthermore, inorganic insulating layer 195a contacts insulating layer 215 (inorganic insulating layer) through an opening in insulating layer 214 (organic insulating layer). This allows light-receiving element 110 and light-emitting element 190 to be surrounded by insulating layer 215 and protective layer 195, improving the reliability of light-receiving element 110 and light-emitting element 190.

[0285] As described above, the protective layer 195 may also have a stacked structure of an organic insulating film and an inorganic insulating film. In this case, the end of the inorganic insulating film preferably extends outside the end of the organic insulating film.

[0286] A lens 149 is provided on the surface of substrate 152 on the substrate 151 side. The convex surface of lens 149 is on the substrate 151 side. Lens 149 overlaps the light receiving area of ​​light receiving element 110. This improves the sensitivity and accuracy of the sensor using light receiving element 110.

[0287] The refractive index of lens 149 is preferably not less than 1.3 and not more than 2.5. Lens 149 can be formed from at least one of an inorganic material and an organic material. For example, lens 149 can be formed from a material containing resin. Alternatively, lens 149 can be formed from a material containing at least one of an oxide and a sulfide.

[0288] Specifically, resins containing chlorine, bromine, or iodine, resins containing heavy metal atoms, resins containing aromatic heterocycles, resins containing sulfur, and the like can be used for lens 149. Alternatively, a resin or a material containing nanoparticles having a higher refractive index than the resin can be used for lens 149. Titanium oxide, zirconium oxide, and the like can be used as nanoparticles.

[0289] Furthermore, cerium oxide, hafnium oxide, lanthanum oxide, magnesium oxide, niobium oxide, tantalum oxide, titanium oxide, yttrium oxide, zinc oxide, an oxide containing indium and tin, or an oxide containing indium, gallium, and zinc, etc. can be used for the lens 149. Alternatively, zinc sulfide, etc. can be used for the lens 149.

[0290] Furthermore, in the display device 100B, the protective layer 195 and the substrate 152 are bonded together by the adhesive layer 142. The adhesive layer 142 overlaps with the light-receiving element 110 and the light-emitting element 190, and the display device 100B adopts a solid sealing structure.

[0291] [Display device 100C] FIG13A shows a cross-sectional view of a display device 100C.

[0292] The display device 100C differs from the display device 100B in the structure of transistors.

[0293] The display device 100C includes a transistor 208 , a transistor 209 , and a transistor 210 on a substrate 151 .

[0294] Transistors 208, 209, and 210 include: a conductive layer 221 serving as a gate; an insulating layer 211 serving as a gate insulating layer; a semiconductor layer including a channel formation region 231i and a pair of low-resistance regions 231n; a conductive layer 222a connected to one of the pair of low-resistance regions 231n; a conductive layer 222b connected to the other of the pair of low-resistance regions 231n; an insulating layer 225 serving as a gate insulating layer; a conductive layer 223 serving as a gate; and an insulating layer 215 covering the conductive layer 223. The insulating layer 211 is located between the conductive layer 221 and the channel formation region 231i. The insulating layer 225 is located between the conductive layer 223 and the channel formation region 231i.

[0295] The conductive layer 222a and the conductive layer 222b are connected to the low resistance region 231n through openings provided in the insulating layer 225 and the insulating layer 215. One of the conductive layer 222a and the conductive layer 222b functions as a source, and the other functions as a drain.

[0296] The pixel electrode 191B of the light-emitting element 190B is electrically connected to one of the pair of low-resistance regions 231n of the transistor 208 through the conductive layer 222b.

[0297] The pixel electrode 181 of the light-receiving element 110 is electrically connected to the other of the pair of low-resistance regions 231 n of the transistor 209 through the conductive layer 222 b .

[0298] FIG13A shows an example in which insulating layer 225 covers the top and side surfaces of a semiconductor layer. Meanwhile, in FIG13B , insulating layer 225 overlaps with channel-forming region 231i of semiconductor layer 231 but does not overlap with low-resistance region 231n. For example, by processing insulating layer 225 using conductive layer 223 as a mask, the structure shown in FIG13B can be achieved. In FIG13B , insulating layer 215 covers insulating layer 225 and conductive layer 223, and conductive layers 222a and 222b are connected to low-resistance region 231n through openings in insulating layer 215. Furthermore, an insulating layer 218 may be provided to cover the transistors.

[0299] [Display device 100D] FIG14 is a cross-sectional view of a display device 100D.

[0300] The display device 100D differs from the display device 100C in that it includes a colored layer 148 a .

[0301] The colored layer 148 a includes a portion in contact with the top surface of the pixel electrode 181 included in the light-receiving element 110 and a portion in contact with the side surface of the partition wall 216 .

[0302] By absorbing stray light generated in the display device 100D with the colored layer 148a, the amount of stray light incident on the light receiving element 110 can be reduced. This can reduce noise and improve the sensitivity of the sensor using the light receiving element 110.

[0303] In addition, the display device 100D is different from the display device 100C in that the display device 100D does not include the substrate 151 and the substrate 152 but includes the substrate 153, the substrate 154, the adhesive layer 155 and the insulating layer 212.

[0304] The substrate 153 and the insulating layer 212 are bonded together by the adhesive layer 155 . The substrate 154 and the protective layer 195 are bonded together by the adhesive layer 142 .

[0305] Display device 100D is formed by transferring insulating layer 212, transistors 208, 209, 210, light-receiving element 110, and light-emitting element 190B, which are formed on a manufacturing substrate, onto substrate 153. Substrates 153 and 154 are preferably flexible. This improves the flexibility of display device 100D.

[0306] As the insulating layer 212, an inorganic insulating film that can be used for the insulating layer 211 and the insulating layer 215 can be used.

[0307] In addition, the display device 100C is shown as an example without the lens 149, while the display device 100D is shown as an example with the lens 149. The lens 149 may be provided as appropriate depending on the application of the sensor, etc.

[0308] [Metal oxides] Hereinafter, metal oxides that can be used in the semiconductor layer will be described.

[0309] In this specification and other documents, metal oxides containing nitrogen may also be referred to as metal oxides. Furthermore, metal oxides containing nitrogen may also be referred to as metal oxynitrides. For example, metal oxides containing nitrogen, such as zinc oxynitride (ZnON), may also be used in semiconductor layers.

[0310] In this specification, it may be referred to as CAAC (c-axis aligned crystal) or CAC (Cloud-Aligned Composite). CAAC refers to an example of a crystal structure, and CAC refers to an example of a function or material composition.

[0311] For example, CAC (Cloud-Aligned Composite)-OS (Oxide Semiconductor) can be used as the semiconductor layer.

[0312] CAC-OS or CAC-metal oxide has conductivity in one part of the material and insulation in another, resulting in the material as a whole functioning as a semiconductor. Furthermore, when CAC-OS or CAC-metal oxide is used in the semiconductor layer of a transistor, its conductivity allows electrons (or holes) to flow, while its insulation prevents the flow of electrons. The complementary effects of conductivity and insulation enable CAC-OS or CAC-metal oxide to have a switching function (the ability to turn on / off). By separating these functions within CAC-OS or CAC-metal oxide, each can be maximized.

[0313] Furthermore, CAC-OS or CAC-metal oxide consists of conductive and insulating regions. The conductive regions have the aforementioned conductivity, while the insulating regions have the aforementioned insulation. Furthermore, within the material, the conductive and insulating regions are sometimes separated at the nanoparticle level. Furthermore, the conductive and insulating regions are sometimes unevenly distributed within the material. Furthermore, sometimes conductive regions are observed to be connected in a cloud-like pattern with blurred edges.

[0314] In addition, in CAC-OS or CAC-metal oxide, conductive regions and insulating regions are sometimes dispersed in the material with a size of 0.5 nm to 10 nm, preferably 0.5 nm to 3 nm.

[0315] Furthermore, CAC-OS or CAC-metal oxide is composed of components with different band gaps. For example, CAC-OS or CAC-metal oxide is composed of a component with a wide band gap, originating from the insulating region, and a component with a narrow band gap, originating from the conductive region. In this structure, when carriers are allowed to flow, they primarily flow through the component with the narrow band gap. Furthermore, the component with the narrow band gap interacts with the component with the wide band gap through a complementary effect, allowing carriers to flow through the component with the wide band gap. Therefore, when such CAC-OS or CAC-metal oxide is used in the channel-forming region of a transistor, high current driving force, i.e., large on-state current and high field-effect mobility, can be achieved in the transistor's on state.

[0316] That is to say, CAC-OS or CAC-metal oxide can also be called a matrix composite material (matrix composite) or a metal matrix composite material (metal matrix composite).

[0317] Oxide semiconductors (metal oxides) are classified into single-crystalline oxide semiconductors and non-single-crystalline oxide semiconductors. Examples of non-single-crystalline oxide semiconductors include CAAC-OS (c-axis aligned crystalline oxide semiconductor), polycrystalline oxide semiconductors, nc-OS (nanocrystalline oxide semiconductor), a-like OS (amorphous-like oxide semiconductor), and amorphous oxide semiconductors.

[0318] CAAC-OS has c-axis alignment, with multiple nanocrystals connected along the ab plane, but the crystal structure exhibits distortion. Note that distortion refers to the difference in lattice alignment between regions where multiple nanocrystals are connected and other regions where the lattice alignment is consistent.

[0319] While nanocrystals are generally hexagonal, they are not limited to regular hexagons and may not be regular. Furthermore, distortion can sometimes have pentagonal or heptagonal lattice arrangements. Furthermore, in CAAC-OS, no clear grain boundaries are observed even near the distortion. This suggests that the lattice distortion suppresses the formation of grain boundaries. This is because CAAC-OS tolerates distortion due to factors such as the low density of oxygen atoms in the ab plane and the changes in interatomic bond distances caused by metal element substitution.

[0320] CAAC-OS tends to have a layered crystal structure (also called a layered structure) in which a layer containing indium and oxygen (hereinafter referred to as an In layer) and a layer containing the element M, zinc, and oxygen (hereinafter referred to as an (M, Zn) layer) are stacked. Indium and the element M are mutually substitutable. When indium replaces the element M in the (M, Zn) layer, the layer can also be expressed as an (In, M, Zn) layer. Furthermore, when indium in the In layer is replaced by the element M, the layer can also be expressed as an (In, M) layer.

[0321] CAAC-OS is a highly crystalline metal oxide. However, since clear grain boundaries are difficult to observe in CAAC-OS, the decrease in electron mobility caused by these grain boundaries is less likely to occur. Furthermore, the crystallinity of metal oxides can sometimes be reduced by the incorporation of impurities or the formation of defects. Therefore, CAAC-OS can be considered a metal oxide with low levels of impurities and defects, such as oxygen vacancies (also known as VO (oxygen vacancy)). Consequently, metal oxides containing CAAC-OS have stable physical properties. Consequently, metal oxides containing CAAC-OS have high heat resistance and reliability.

[0322] In nc-OS, the atomic arrangement within tiny regions (e.g., regions between 1 nm and 10 nm, and particularly between 1 nm and 3 nm) exhibits periodicity. Furthermore, in nc-OS, no regularity in crystal orientation is observed between different nanocrystals. Consequently, no orientation is observed across the entire film. Consequently, nc-OS can sometimes be indistinguishable from a-like OS or amorphous oxide semiconductors using certain analytical methods.

[0323] Furthermore, indium-gallium-zinc oxide (IGZO), a metal oxide containing indium, gallium, and zinc, sometimes has a stable structure when formed from the aforementioned nanocrystals. In particular, because IGZO tends to have difficulty growing in the atmosphere, it is sometimes structurally more stable when formed from small crystals (e.g., the aforementioned nanocrystals) than when formed from large crystals (here, crystals measuring several millimeters or centimeters).

[0324] a-like OS is a metal oxide with a structure intermediate between nc-OS and amorphous oxide semiconductors. It contains voids or low-density regions. In other words, a-like OS has lower crystallinity than nc-OS and CAAC-OS.

[0325] Oxide semiconductors (metal oxides) have various structures and properties. The oxide semiconductor according to 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 nc-OS, and a CAAC-OS.

[0326] The metal oxide film used as the semiconductor layer can be formed using either or both an inert gas and an oxygen gas. Note that there are no particular restrictions on the oxygen flow rate (oxygen partial pressure) during metal oxide film formation. However, to achieve a transistor with high field-effect mobility, the oxygen flow rate (oxygen partial pressure) during metal oxide film formation is preferably 0% to 30%, more preferably 5% to 30%, and even more preferably 7% to 15%.

[0327] The band gap of the metal oxide is preferably greater than 2 eV, more preferably greater than 2.5 eV, and even more preferably greater than 3 eV. Thus, by using a metal oxide with a wide band gap, the off-state current of the transistor can be reduced.

[0328] The substrate temperature during metal oxide film formation is preferably 350°C or lower, more preferably room temperature or higher and 200°C or lower, and even more preferably room temperature or higher and 130°C or lower. The substrate temperature during metal oxide film formation is preferably room temperature because it can improve productivity and is therefore preferred.

[0329] The metal oxide film can be formed by sputtering. In addition, PLD, PECVD, thermal CVD, ALD, vacuum evaporation, etc. can also be used.

[0330] As described above, the display device of this embodiment includes a light-receiving element and a light-emitting element in the display portion, and the display portion has both the function of displaying images and the function of detecting light. This allows for a smaller and lighter electronic device compared to a case where sensors are located outside the display portion or the display device. Furthermore, it is possible to combine sensors located outside the display portion or the display device to realize an electronic device with more functions.

[0331] At least one of the layers disposed between a pair of electrodes in a light-receiving element can have the same structure as a light-emitting element (EL element). For example, all layers other than the active layer in a light-receiving element can have the same structure as a light-emitting element (EL element). In other words, by simply adding a process for forming the active layer to the light-emitting element manufacturing process, a light-emitting element and a light-receiving element can be formed on the same substrate. Furthermore, the pixel electrodes and common electrodes of the light-receiving element and the light-emitting element can be formed using the same material and the same process. Furthermore, by using the same material and the same process to manufacture the circuit electrically connected to the light-receiving element and the circuit electrically connected to the light-emitting element, the manufacturing process of the display device can be simplified. This allows for the manufacture of a highly convenient display device with a built-in light-receiving element without complex manufacturing processes.

[0332] This embodiment mode can be appropriately combined with other embodiment modes. In addition, in this specification, when multiple structural examples are shown in one embodiment mode, the structural examples can be appropriately combined.

[0333] Implementation Method 2 In this embodiment, a display device according to one embodiment of the present invention is described with reference to FIG. 15 .

[0334] A display device according to one embodiment of the present invention includes a first pixel circuit having a light-receiving element and a second pixel circuit having a light-emitting element. The first pixel circuit and the second pixel circuit are each arranged in a matrix.

[0335] FIG15A shows an example of a first pixel circuit including a light-receiving element, and FIG15B shows an example of a second pixel circuit including a light-emitting element.

[0336] 15A 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.

[0337] The cathode of the photodetector PD is electrically connected to wiring V1, and the anode is electrically connected to one of the source and drain of transistor M1. The gate of transistor M1 is electrically connected to wiring TX, and the other of its source and drain is electrically connected to one electrode of capacitor C1, one of the source and drain of transistor M2, and the gate of transistor M3. The gate of transistor M2 is electrically connected to wiring RES, and the other of its source and drain is electrically connected to wiring V2. One of the source and drain of transistor M3 is electrically connected to wiring V3, and the other of its source and drain is electrically connected to one of the source and drain of transistor M4. The gate of transistor M4 is electrically connected to wiring SE, and the other of its source and drain is electrically connected to wiring OUT1.

[0338] Wiring V1, wiring V2, and wiring V3 are each supplied with a constant potential. When the light-receiving element PD is driven with a reverse bias, a potential lower than that of wiring V1 is supplied to wiring V2. Transistor M2 is controlled by a signal supplied to wiring RES, causing the potential of the node connected to the gate of transistor M3 to be reset to the potential supplied to wiring V2. Transistor M1 is controlled by a signal supplied to wiring TX, controlling the timing of potential changes at these nodes based on the current flowing through light-receiving element PD. Transistor M3 functions as an amplifier transistor, outputting outputs based on the potentials of these nodes. Transistor M4, controlled by a signal supplied to wiring SE, functions as a select transistor, which is used to read the output based on the potentials of these nodes using an external circuit connected to wiring OUT1.

[0339] The pixel circuit PIX2 shown in FIG15B includes a light-emitting element EL, a transistor M5, a transistor M6, a transistor M7, and a capacitor C2. Here, an example using a light-emitting diode as the light-emitting element EL is shown. In particular, an organic EL element is preferably used as the light-emitting element EL.

[0340] The gate of transistor M5 is electrically connected to wiring VG, one of its source and drain is electrically connected to wiring VS, and the other of its source and drain is electrically connected to one electrode of capacitor C2 and the gate of transistor M6. One of its source and drain is electrically connected to wiring V4, and the other of its source and drain is electrically connected to the anode of light-emitting element EL and one of the source and drain of transistor M7. The gate of transistor M7 is electrically connected to wiring MS, and the other of its source and drain is electrically connected to wiring OUT2. The cathode of light-emitting element EL is electrically connected to wiring V5.

[0341] Wiring V4 and wiring V5 are each supplied with a constant potential. The anode side and cathode side of the light-emitting element EL can be set to a higher potential and a potential lower than the anode side, respectively. Transistor M5 is controlled by a signal supplied to wiring VG and functions as a selection transistor for controlling the selection state of pixel circuit PIX2. Furthermore, transistor M6 functions as a drive transistor that controls the current flowing through the light-emitting element EL based on the potential supplied to its gate. When transistor M5 is in the on state, the potential supplied to wiring VS is supplied to the gate of transistor M6, and the brightness of the light-emitting element EL can be controlled based on this potential. Transistor M7 is controlled by a signal supplied to wiring MS and outputs the potential between transistor M6 and the light-emitting element EL to the outside via wiring OUT2.

[0342] The wiring V1 electrically connected to the cathode of the light-receiving element PD and the wiring V5 electrically connected to the cathode of the light-emitting element EL may be in the same layer and have the same potential.

[0343] In the display device of this embodiment, the light-emitting element can also be pulsed to display images. By shortening the driving time of the light-emitting element, the display device's power consumption can be reduced and heat generation can be suppressed. Organic EL elements are particularly preferred due to their excellent frequency characteristics. For example, the frequency can be between 1 kHz and 100 MHz.

[0344] Here, the transistors M1, M2, M3, and M4 included in the pixel circuit PIX1 and the transistors M5, M6, and M7 included in the pixel circuit PIX2 are preferably transistors whose semiconductor layers forming their channels contain metal oxide (oxide semiconductor).

[0345] Transistors using metal oxides, which have a wider band gap than silicon and a lower carrier density, can achieve extremely low off-state current. Due to their low off-state current, they can retain the charge stored in the capacitor connected in series with the transistor for a long period of time. Therefore, transistors M1, M2, and M5, particularly those connected in series with capacitors C1 and C2, are preferably transistors containing oxide semiconductors. Furthermore, the use of transistors containing oxide semiconductors for other transistors can also reduce manufacturing costs.

[0346] Furthermore, transistors M1 through M7 may also use transistors whose channels are formed of semiconductors containing silicon. In particular, using highly crystalline silicon, such as single-crystal silicon or polycrystalline silicon, can achieve high field-effect mobility, enabling higher-speed operation.

[0347] In addition, at least one of the transistors M1 to M7 may use a transistor containing an oxide semiconductor, and the other transistors may use a transistor containing silicon.

[0348] 15A and 15B illustrate n-channel transistors, but p-channel transistors may also be used.

[0349] The transistors included in the pixel circuit PIX1 and the transistors included in the pixel circuit PIX2 are preferably arranged on the same substrate. In particular, the transistors included in the pixel circuit PIX1 and the transistors included in the pixel circuit PIX2 are preferably mixed and formed in one area and arranged periodically.

[0350] Furthermore, it is preferred to provide one or more layers including one or both of a transistor and a capacitor at a position overlapping the light-receiving element PD or the light-emitting element EL. This can reduce the effective area occupied by each pixel circuit, thereby achieving a high-resolution display unit.

[0351] This embodiment mode can be combined with other embodiment modes as appropriate.

[0352] Implementation 3 In this embodiment, a method for driving a display device according to one embodiment of the present invention will be described with reference to FIG. 16 and FIG. 17 .

[0353] In this embodiment, a case where a display device according to one embodiment of the present invention is used as a touch panel will be described.

[0354] High resolution is required to capture fingerprints, so it's best to read the image data acquired using the light-receiving element individually (pixel by pixel) for all pixels. On the other hand, when using the display device as a touch panel, the high resolution required for fingerprint authentication isn't necessary, but high-speed reading is required.

[0355] For example, by using multiple pixels to detect touches simultaneously, the driving frequency can be increased. For example, the number of pixels read out simultaneously can be appropriately set to 4 pixels (2×2 pixels), 9 pixels (3×3 pixels), or 16 pixels (4×4 pixels).

[0356] FIG. 16A shows image data read out at once from the light-receiving elements PD included in a plurality of pixels.

[0357] A single pixel 300 includes a light-receiving element PD, a sub-pixel R emitting red light, a sub-pixel G emitting green light, and a sub-pixel B emitting blue light. Although Figure 16A shows an example in which a unit 310 includes nine pixels 300 (3×3 pixels), there is no particular limitation on the number of pixels a unit 310 may include. Image data is read out simultaneously from pixels 300 in the same unit 310. For example, image data from unit 310a is read out first, followed by image data from unit 310b. This reduces the number of readouts compared to reading out image data pixel by pixel, thereby increasing the drive frequency. Furthermore, since the image data from unit 310a is a combination of image data from multiple pixels 300 (here, nine pixels 300), sensitivity can be improved compared to capturing image data pixel by pixel.

[0358] Alternatively, only a portion of the pixels can be used for touch detection. For example, one pixel out of every four pixels (2×2 pixels), one pixel out of every 100 pixels (10×10 pixels), or one pixel out of every 900 pixels (30×30 pixels) can be used as a pixel for touch detection.

[0359] FIG. 16B shows an example of detecting a touch using only a portion of pixels.

[0360] A single pixel 300 includes a light-receiving element PD, a sub-pixel R emitting red light, a sub-pixel G emitting green light, and a sub-pixel B emitting blue light. The target pixels 320 to be read are only those enclosed by the dotted line. Although Figure 16B shows an example where one of every nine pixels (3×3 pixels) is used as the target pixel 320 for touch detection, the number of target pixels 320 is not limited to this. First, the image data of target pixel 320a is read, followed by the image data of target pixel 320b. Image data is not read from the pixels 300 between target pixels 320a and 320b. This reduces the number of readouts compared to reading image data from all pixels one by one, allowing for a higher drive frequency.

[0361] Alternatively, a plurality of pixels 300 may be used alternately as target pixels 320. For example, when one of every nine pixels is used as target pixel 320, target pixels 320 may be shifted row or column to alternately use three pixels as target pixels 320. Alternatively, nine pixels may be used alternately as target pixels 320.

[0362] A display device according to one embodiment of the present invention includes two or more operating modes for its light-receiving elements, preferably switchable between these modes. For example, it is preferred that all pixels can be switched between a mode in which each pixel is read independently and a mode in which multiple pixels are read simultaneously. Alternatively, it is preferred that all pixels be read and only a portion of the pixels be read. This allows for high-resolution fingerprint capture and high-frequency touch detection when displaying images.

[0363] In addition, the influence of ambient light, which can cause noise when detecting touch, can be removed.

[0364] For example, by using a portion of pixels to periodically turn the light-emitting element on and off, and obtaining the detection intensity of the light-receiving element when it is on and off (not lit), the influence of ambient light can be eliminated. It is preferable to provide a plurality of pixels that repeatedly turn on and off within a range that does not affect the image displayed by the display device. Furthermore, it is preferable to repeatedly turn the light-emitting element on and off within each frame. For example, it is preferable to alternate the pixels that are turned on and off between odd-numbered and even-numbered frames. Note that there are no particular restrictions on the color of the light emitted when it is on.

[0365] In FIG17A , pixels 330 a and 330 d are turned off and pixels 330 b and 330 c are turned on. In FIG17B , pixels 330 a and 330 d are turned on and pixels 330 b and 330 c are turned off.

[0366] Pixel 330b detects ambient light, so the detection intensity of the light-receiving element remains unchanged between when the light source is on and when it is off. On the other hand, pixel 330d detects light reflected by finger 340, so the detection intensity of the light-receiving element varies between when the light-emitting element is on and when it is off. By utilizing this difference in detection intensity between on and off times, the influence of ambient light can be eliminated.

[0367] Thus, the display device of this embodiment can be driven in either a cell-by-cell mode or a light-receiving element-by-light-receiving element mode. For example, the cell-by-cell mode can be used when high-speed operation is required. Alternatively, when high-resolution imaging is required, the pixel-by-pixel (light-receiving element-by-light-receiving element) mode can be used. By changing the driving mode according to the application, the functionality of the display device can be improved.

[0368] This embodiment mode can be combined with other embodiment modes as appropriate.

[0369] Implementation 4 In this embodiment, an electronic device according to one embodiment of the present invention will be described using FIG. 18 to FIG. 20 .

[0370] The electronic device of this embodiment includes a display device according to one embodiment of the present invention. For example, the display device according to one embodiment of the present invention can be used in the display portion of the electronic device. Because the display device according to one embodiment of the present invention has the function of detecting light, it can perform biometric authentication or detect touch or proximity on the display portion. This can improve the functionality and convenience of the electronic device.

[0371] Examples of electronic devices include televisions, desktop and laptop personal computers, monitors for computers, digital signage, large-scale game consoles such as pinball machines, and other electronic devices with large screens. Other examples include digital cameras, digital video cameras, digital photo frames, mobile phones, portable game consoles, portable information terminals, and audio playback devices.

[0372] The electronic device of this embodiment may also include a sensor (the sensor has the function of measuring the following factors: force, displacement, position, speed, acceleration, angular velocity, rotation speed, distance, light, liquid, magnetism, temperature, chemical substances, sound, time, hardness, electric field, current, voltage, electricity, radiation, flow, humidity, tilt, vibration, smell or infrared).

[0373] The electronic device of this embodiment can have various functions. For example, it can have the following functions: the function of displaying various information (still images, moving images, text images, etc.) on the display unit; the function of using a touch panel; the function of displaying the calendar, date, or time; the function of executing various software (programs); the function of conducting wireless communication; the function of reading programs or data stored in a storage medium; etc.

[0374] The electronic device 6500 shown in FIG18A is a portable information terminal device that can be used as a smart phone.

[0375] 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, a light source 6508, and the like. The display portion 6502 has a touch panel function.

[0376] The display portion 6502 can use the display device of one embodiment of the present invention.

[0377] FIG18B is a schematic cross-sectional view of an end portion of the housing 6501 on the microphone 6506 side.

[0378] A light-transmitting protective component 6510 is provided on the display surface side of the housing 6501. The space surrounded by the housing 6501 and the protective component 6510 contains a display panel 6511, an optical component 6512, a touch sensor panel 6513, a printed circuit board 6517, a battery 6518, etc.

[0379] The display panel 6511 , the optical member 6512 , and the touch sensor panel 6513 are fixed to the protective member 6510 using an adhesive layer (not shown).

[0380] In a region outside the display portion 6502, a portion of the display panel 6511 is folded back, and an FPC 6515 is connected to the folded back portion. An IC 6516 is mounted on the FPC 6515. The FPC 6515 is connected to terminals provided on a printed circuit board 6517.

[0381] The display panel 6511 can use the flexible display of one embodiment of the present invention. This allows for an extremely lightweight electronic device. Furthermore, because the display panel 6511 is extremely thin, a large-capacity battery 6518 can be installed while reducing the thickness of the electronic device. Furthermore, by folding a portion of the display panel 6511 to provide a connection to the FPC 6515 on the back of the pixel unit, an electronic device with a narrow frame can be realized.

[0382] 19A shows an example of a television set. In a television set 7100, a display portion 7000 is incorporated into a housing 7101. Here, a structure in which the housing 7101 is supported by a stand 7103 is shown.

[0383] The display device according to one embodiment of the present invention can be applied to the display portion 7000 .

[0384] The television set 7100 shown in FIG19A can be operated using operation switches provided on the housing 7101 or a separately provided remote control 7111. Alternatively, a touch sensor may be provided on the display portion 7000, allowing the television set 7100 to be operated by touching the display portion 7000 with a finger or the like. Furthermore, the remote control 7111 may include a display portion for displaying data output from the remote control 7111. Using the operation keys or touch panel provided on the remote control 7111, the channel and volume can be controlled, and the image displayed on the display portion 7000 can be manipulated.

[0385] Furthermore, television set 7100 includes a receiver and a modem. The receiver can receive standard television broadcasts. Furthermore, the modem can be connected to a wired or wireless communication network to enable one-way (from sender to receiver) or two-way (between sender and receiver, or between receivers) information communication.

[0386] 19B shows an example of a notebook personal computer. A notebook personal computer 7200 includes a housing 7211 , a keyboard 7212 , a pointing device 7213 , an external connection port 7214 , and the like. A display portion 7000 is incorporated into the housing 7211 .

[0387] The display device according to one embodiment of the present invention can be applied to the display portion 7000 .

[0388] 19C and 19D show an example of a digital signage.

[0389] The digital signage 7300 shown in FIG19C includes a housing 7301, a display unit 7000, and a speaker 7303. Furthermore, it may include an LED light, operation keys (including a power switch or an operation switch), connection terminals, various sensors, a microphone, and the like.

[0390] 19D shows a digital signage 7400 mounted on a cylindrical pillar 7401. The digital signage 7400 includes a display portion 7000 disposed along the curved surface of the pillar 7401.

[0391] In FIG. 19C and FIG. 19D , the display device according to one embodiment of the present invention can be applied to the display portion 7000 .

[0392] The larger the display unit 7000 is, the more information it can provide at one time. The larger the display unit 7000 is, the easier it is to attract people's attention, for example, it can improve the effectiveness of advertising.

[0393] Using a touch panel for display unit 7000 is advantageous because it not only allows for the display of still and moving images but also allows for intuitive user operation. Furthermore, when used to provide information such as route information or traffic information, intuitive operation improves usability.

[0394] As shown in Figures 19C and 19D , digital signage 7300 or 7400 can preferably be linked via wireless communication with a user's information terminal device 7311 or 7411, such as a smartphone. For example, advertising information displayed on display unit 7000 can be displayed on the screen of information terminal device 7311 or 7411. Furthermore, the display on display unit 7000 can be switched by operating information terminal device 7311 or 7411.

[0395] Furthermore, the game can be played on the digital signage 7300 or 7400 using the screen of the information terminal device 7311 or 7411 as an operating unit (controller). This allows an unspecified number of users to participate in the game simultaneously and enjoy the game.

[0396] The electronic device shown in Figures 20A to 20F includes a housing 9000, a display portion 9001, a speaker 9003, an operation key 9005 (including a power switch or an operation switch), a connection terminal 9006, a sensor 9007 (the sensor has the function of measuring the following factors: force, displacement, position, speed, acceleration, angular velocity, rotation speed, distance, light, liquid, magnetism, temperature, chemical substances, sound, time, hardness, electric field, current, voltage, electricity, radiation, flow, humidity, inclination, vibration, smell or infrared rays), a microphone 9008, etc.

[0397] The electronic devices shown in Figures 20A to 20F have various functions. For example, they may have the following functions: the function of displaying various information (still images, moving images, text images, etc.) on a display unit; the function of a touch panel; the function of displaying a calendar, date, or time; the function of controlling processing using various software (programs); the function of conducting wireless communications; the function of reading and processing programs or data stored in a storage medium; and so on. Note that the functions that an electronic device may have are not limited to the functions described above and may have a variety of functions. An electronic device may include multiple display units. Furthermore, an electronic device may be provided with a camera or the like to enable the following functions: the function of capturing still or moving images and storing the captured images in a storage medium (external storage medium or storage medium built into the camera); the function of displaying the captured images on a display unit; and so on.

[0398] Next, the electronic device shown in FIG. 20A to FIG. 20F will be described in detail.

[0399] Figure 20A is a perspective view of a portable information terminal 9101. Portable information terminal 9101 can be used, for example, as a smartphone. Note that portable information terminal 9101 may also be provided with a speaker 9003, a connection terminal 9006, a sensor 9007, and the like. Furthermore, portable information terminal 9101 can display text or video information on multiple surfaces. Figure 20A shows an example of three icons 9050. Furthermore, information 9051, indicated by a dashed rectangle, can be displayed on other surfaces of display portion 9001. Examples of information 9051 include information notifying of the receipt of an email, social media, or phone call; the title of the email or social media; the name of the sender of the email or social media; the date; the time; the remaining battery level; and an indication of the antenna reception signal strength. Alternatively, icons 9050 and the like can be displayed in place of information 9051.

[0400] Figure 20B is a perspective view of a portable information terminal 9102. Portable information terminal 9102 has the function of displaying information on three or more surfaces of display unit 9001. Here, an example is shown in which information 9052, information 9053, and information 9054 are displayed on different surfaces. For example, when portable information terminal 9102 is placed in a jacket pocket, the user can check information 9053 displayed from above. The user can check this display without removing portable information terminal 9102 from their pocket, allowing them to decide whether to answer a call, for example.

[0401] Figure 20C is a perspective view of a watch-type portable information terminal 9200. The portable information terminal 9200 can be used, for example, as a smartwatch. Furthermore, the display surface of the display portion 9001 is curved, allowing for display along the curved display surface. Furthermore, the portable information terminal 9200 can communicate with a wireless headset, for example, for hands-free calling. Furthermore, by utilizing the connection terminal 9006, the portable information terminal 9200 can transmit data with other information terminals or be charged. Charging can also be performed via wireless power supply.

[0402] Figures 20D and 20F are perspective views of a foldable portable information terminal 9201. Figure 20D shows the portable information terminal 9201 in its unfolded state, Figure 20F shows it in its folded state, and Figure 20E shows it midway through transitioning from one of the states in Figures 20D and 20F. The portable information terminal 9201 offers excellent portability in its folded state, while its unfolded state offers a large, seamless display area, making the display highly readable. The display portion 9001 included in the portable information terminal 9201 is supported by three housings 9000 connected by hinges 9055. The display portion 9001 can be bent, for example, within a radius of curvature between 0.1 mm and 150 mm.

[0403] This embodiment mode can be combined with other embodiment modes as appropriate. Example 1

[0404] This example describes the results of evaluations of light-emitting and light-receiving elements that can be used in a display device according to one embodiment of the present invention. Note that an element that functions as both a light-emitting element and a light-receiving element will be referred to as a light-emitting and light-receiving element.

[0405] In this embodiment, two light-receiving and light-emitting elements (device 1 and device 2) are manufactured. The light-receiving and light-emitting elements manufactured in this embodiment have the same structure as the light-emitting element (organic EL element).

[0406] The chemical formulas of the materials used in this example are shown below.

[0407] [Chemical Formula 1]

[0408] Table 1 shows the specific structure of the light-emitting and light-receiving elements of this embodiment. Device 1 uses the stacked structure of light-emitting element 47R, which emits red (R) light, and light-receiving element 46, shown in Figure 7A. Device 1 has a stacked structure that can be manufactured by replacing the hole transport layer of the light-emitting element with the active layer of the light-receiving element. Device 2 uses the stacked structure of light-emitting element 47R, which emits red (R) light, and light-receiving element 46, shown in Figure 7B. Device 2 has a stacked structure that can be manufactured by adding the active layer of the light-receiving element to the light-emitting element.

[0409]

[0410] The first electrode was formed by forming an alloy of silver (Ag), palladium (Pd), and copper (Cu) (Ag-Pd-Cu (APC)) to a thickness of 100 nm by sputtering and forming indium tin oxide containing silicon oxide (ITSO) to a thickness of 100 nm by sputtering.

[0411] The hole injection layer was formed by co-evaporating 3-[4-(9-phenanthrenyl)-phenyl]-9-phenyl-9H-carbazole (abbreviated as PCPPn) and molybdenum oxide at a weight ratio of 2:1. The thickness of the layer corresponding to the hole injection layer was approximately 15 nm.

[0412] The active layer is formed by co-evaporating fullerene (C70) and tetraphenyldibenzoindenepyrene (DBP) at a weight ratio of C70:DBP = 9:1. The thickness of the active layer is approximately 60 nm.

[0413] The hole transport layer was not provided in device 1 but in device 2. As the hole transport layer, N-(1,1'-biphenyl-4-yl)-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-9,9-dimethyl-9H-fluoren-2-amine (abbreviated as PCBBiF) was used and was evaporated to a film thickness of 70 nm.

[0414] The light-emitting layer was formed by co-evaporation of 2-[3'-(dibenzothiophene-4-yl)biphenyl-3-yl]dibenzo[f,h]quinoline (abbreviated as 2mDBTBPDBq-II), PCBBiF, and bis{4,6-dimethyl-2-[3-(3,5-dimethylphenyl)-5-phenyl-2-pyrazinyl-κN]phenyl-κC}(2,6-dimethyl-3,5-heptanedione-κ2O,O')iridium(III) (abbreviated as [Ir(dmdppr-P) 2(dibm)]) at a weight ratio of 0.8:0.2:0.06 (=2mDBTBPDBq-II:PCBBiF:[Ir(dmdppr-P) 2(dibm)]) to a thickness of 70 nm.

[0415] The electron transport layer was formed by sequentially depositing 2mDBTBPDBq-II and 2,9-bis(naphthalene-2-yl)-4,7-diphenyl-1,10-phenanthroline (NBPhen) to a thickness of 10 nm.

[0416] The electron injection layer was formed by vapor deposition using lithium fluoride (LiF) to a thickness of 1 nm.

[0417] Silver (Ag) and magnesium (Mg) were co-evaporated at a volume ratio of 10:1 to a thickness of 10 nm, and then indium tin oxide (ITO) was formed by sputtering to a thickness of 40 nm to form a second electrode.

[0418] Through the above steps, the light-receiving and light-emitting element of this embodiment is manufactured.

[0419] [Characteristics as a light-emitting element] First, the characteristics of the light-emitting element (when forward bias is applied) as a light-receiving and light-emitting element were evaluated. Figure 21 shows the voltage-luminance characteristics of the light-receiving and light-emitting element. Figure 22 shows the luminance-external quantum efficiency characteristics of the light-receiving and light-emitting element.

[0420] It was confirmed that both device 1 and device 2 functioned normally as light-emitting elements. In particular, device 2, which provided a hole transport layer between the active layer and the light-emitting layer, achieved high external quantum efficiency.

[0421] [Characteristics as a light-receiving element] Next, the characteristics of the light-receiving and luminescent element as a light-receiving element (characteristics when reverse bias is applied) were evaluated. Figure 23 shows the wavelength dependence of the light sensitivity of the light-receiving and luminescent element. The measurement conditions were as follows: -6V voltage and 10μW / cm² of light irradiation. Note that the voltage applied here is generally the value when the bias applied to the EL device is positive. In other words, when the first electrode side is at a high potential and the second electrode side is at a low potential, the voltage is positive.

[0422] It was confirmed that both device 1 and device 2 functioned normally as light-receiving elements.

[0423] As described above, in this embodiment, a light-emitting and receiving element having the same structure as a light-emitting element (organic EL element) is manufactured, and good characteristics as both the light-emitting element and the light-receiving element can be obtained.

[0424] According to this embodiment, it can be seen that device 1 and device 2 can respectively operate as a light-emitting element and a light-receiving element. Therefore, it can be seen that the light-emitting element 47R and the light-receiving element 46 can share the structure of device 1 or device 2.

[0425] C1: Capacitor C2: capacitor IR: luminous element M1: transistor M2: transistor M3: transistor M4: transistor M5: transistor M6: transistor M7: transistor OUT1: Wiring OUT2: Wiring PD: light receiving element PIX1: Pixel circuit PIX2: Pixel Circuit V1: Wiring V2: Wiring V3: Wiring V4: Wiring V5: Wiring 10A: Display device 10B: Display device 10C: Display device 10D: Display device 10E: Display device 10F: Display device 21B: Light 21G: Light 21R: Light 22: Light 23a: Light 23b: Reflected Light 41: Transistor 42: Transistor 46: Light receiving element 47: Light-emitting element 47B: Light-emitting element 47G: Light-emitting element 47R: Light-emitting element 50A: Display device 50B: Display device 51:Substrate 52: Fingers 53: Layer including light-receiving element 55: Layer including transistors 57: Layer including light emitting element 59:Substrate 100A: Display device 100B: Display device 100C: Display device 100D: Display device 110: Light receiving element 112: Public layer 114: Public layer 115: shared electrode 142: Adhesive layer 143: Space 148a: Colored layer 149: Lens 151:Substrate 152:Substrate 153:Substrate 154:Substrate 155: Adhesive layer 162: Display unit 164: Circuit 165: Wiring 166: conductive layer 172:FPC 173:IC 181: Pixel electrode 182: buffer layer 183: Active layer 184: buffer layer 190: Light-emitting element 190B: Light-emitting element 190G: Light-emitting element 190R: Light-emitting element 191: Pixel electrode 191B: Pixel electrode 191G: Pixel electrode 192: buffer layer 192B: buffer layer 192G: buffer layer 192R: buffer layer 193: Luminescent layer 193B: Luminescent layer 193G: Luminous layer 193R: Luminescent layer 193Y: luminescent layer 194: buffer layer 194B: buffer layer 194G: buffer layer 194R: buffer layer 195: Protective layer 195a: Inorganic insulating layer 195b: organic insulating layer 195c: Inorganic insulating layer 201: Transistor 204:Connection 205: Transistor 206: Transistor 207: Transistor 208: Transistor 209: Transistor 210: Transistor 211: Insulation layer 212: Insulation layer 213: Insulation layer 214: Insulation layer 215: Insulation layer 216: Partition wall 217: Partition wall 218: Insulation layer 221: conductive layer 222a: conductive layer 222b: conductive layer 223: conductive layer 225: Insulation layer 228: Area 231: semiconductor layer 300: pixels 310: Unit 310a: Unit 310b: Unit 320: Object pixels 320a: object pixel 320b: object pixel 330a: Pixel 330b:pixel 330c: Pixel 330d: Pixel 340:Fingers 231i: Channel formation region 231n: low resistance area 242: Connection layer 6500: Electronic devices 6501: Housing 6502: Display unit 6503:Power button 6504: Button 6505: Speaker 6506: Microphone 6507: Camera 6508: Light Source 6510: Protective components 6511: Display Panel 6512: Optical components 6513: Touch sensor panel 6515:FPC 6516:IC 6517:Printed Circuit Board 6518:Battery 7000: Display unit 7100: TV 7101: Housing 7103: Bracket 7111: Remote Control 7200: Laptop PC 7211: Shell 7212:Keyboard 7213:Pointing device 7214: External port 7300: Digital Signage 7301: Housing 7303:Speaker 7311: Information terminal equipment 7400: Digital Signage 7401: Pillar 7411: Information terminal equipment 9000: Shell 9001: Display unit 9003: Speaker 9005: Operation keys 9006:Connection terminal 9007:Sensor 9008: Microphone 9050: Image 9051: Information 9052: Information 9053: Information 9054: Information 9055:Hinge 9101: Portable Information Terminal 9102: Portable Information Terminal 9200: Portable Information Terminal 9201: Portable Information Terminal

Claims

1. A display device comprising a display portion, the display portion comprising: a light-receiving element comprising a first pixel electrode, a common electrode, an active layer between the first pixel electrode and the common electrode, a first layer between the active layer and the common electrode, and a first common layer between the first pixel electrode and the active layer; a first light-emitting element comprising a second pixel electrode, the common electrode, a first light-emitting layer between the second pixel electrode and the common electrode, the first layer between the first light-emitting layer and the common electrode, and the first common layer between the second pixel electrode and the first light-emitting layer; and a second light-emitting element comprising a third pixel electrode, the common electrode, a second light-emitting layer between the third pixel electrode and the common electrode, and the first layer between the second light-emitting layer and the common electrode, wherein the first layer serves as an electron transport layer in each of the light-receiving element, the first light-emitting element, and the second light-emitting element, and wherein the active layer comprises a first organic compound.

2. A display device comprising a display section, the display section comprising: a light-receiving element comprising a first pixel electrode, a first common layer above the first pixel electrode, an active layer above the first common layer, a first layer above the active layer, and a common electrode above the first layer; a first light-emitting element comprising a second pixel electrode, the first common layer above the second pixel electrode, a first light-emitting layer above the first common layer, the first layer above the first light-emitting layer, and the common electrode above the first layer; and a second light-emitting element comprising a third pixel electrode, a second light-emitting layer above the third pixel electrode, the first layer above the second light-emitting layer, and the common electrode above the first layer, wherein the first layer serves as an electron transport layer in each of the light-receiving element, the first light-emitting element, and the second light-emitting element, wherein the active layer comprises a first organic compound, and wherein the first light-emitting element emits light of a first color to the outside of the display device through the common electrode. The second light-emitting element emits light of a second color to the outside of the display device through the common electrode, and the light-receiving element receives light from the outside of the display device through the common electrode.

3. A display device comprising a display section, the display section comprising: a light-receiving element comprising a first pixel electrode, a common electrode, an active layer between the first pixel electrode and the common electrode, a first layer between the active layer and the common electrode, and a first common layer between the first pixel electrode and the active layer; a first light-emitting element comprising a second pixel electrode, the common electrode, a first light-emitting layer between the second pixel electrode and the common electrode, the first layer between the first light-emitting layer and the common electrode, and the first common layer between the second pixel electrode and the first light-emitting layer; a second light-emitting element comprising a third pixel electrode, the common electrode, a second light-emitting layer between the third pixel electrode and the common electrode, and the first layer between the second light-emitting layer and the common electrode; and a third light-emitting element comprising a fourth pixel electrode, the common electrode, and the first layer between the fourth pixel electrode and the common electrode, wherein the first layer serves as an electron transport layer in each of the light-receiving element, the first light-emitting element, and the second light-emitting element, wherein the first layer serves as a third light-emitting layer in the third light-emitting element, and wherein the active layer comprises a first organic compound.

4. The display device of claim 3, wherein the first light-emitting element emits light of a first color to the outside of the display device through the common electrode, wherein the second light-emitting element emits light of a second color to the outside of the display device through the common electrode, and wherein the third light-emitting element emits light of a third color to the outside of the display device through the common electrode.

5. The display device as requested in item 4, wherein the third color is blue.

6. The display device of any one of claims 1 to 3, wherein the first common layer is located between the third pixel electrode and the second light-emitting layer.

7. The display device of any one of claims 1 to 3 further includes a second common layer, wherein the second common layer is located between the first layer and the common electrode.

8. The display device according to any one of claims 1 to 3, wherein the display portion further includes a partition wall, wherein the partition wall covers the end of the first pixel electrode and the end of the second pixel electrode, and wherein the partition wall has the function of electrically insulating the first pixel electrode from the second pixel electrode.

Images