Display device, display module, and electronic apparatus

Abstract

Provided is a display device with good display quality. The display device comprises, in a display unit, a first sub pixel having a first light emitting device and a first colored layer that transmits blue light. The first light emitting device comprises a first pixel electrode, a first EL layer, and a common electrode. The first EL layer comprises a first light emitting material that emits blue light, and a second light emitting material that emits light of a wavelength longer than blue. The first EL layer comprises a first light emitting unit on the first pixel electrode, a charge generating layer on the first light emitting unit, and a second light emitting unit on the charge generating layer. When the intensity of a first light emission peak at wavelength greater than or equal to 400 nm but less than 500 nm in the light emission spectrum when the display unit displays blue at low brightness is defined as 1, the intensity of a second light emission peak at a wavelength greater than or equal to 500 nm but less than 700 nm is 0.5 or less.

Description

Display device, display module, and electronic device

[0001] 1. Field of the Invention One embodiment of the present invention relates to a display device, a display module, and an electronic device. 2. Description of the Related Art One embodiment of the present invention relates to a manufacturing method of a display device.

[0002] One embodiment of the present invention is not limited to the above technical field, and examples of the technical field of one embodiment of the present invention include semiconductor devices, display devices, light-emitting devices, power storage devices, memory devices, electronic devices, lighting devices, input devices (e.g., touch sensors), input / output devices (e.g., touch panels), driving methods thereof, and manufacturing methods thereof.

[0003] In recent years, display devices have been expected to be used in a variety of applications. For example, applications of large display devices include home television devices (also called televisions or television receivers), digital signage, and public information displays (PIDs). In addition, development of mobile information terminals, such as smartphones and tablet terminals equipped with touch panels, is progressing.

[0004] There is also a demand for higher definition display devices. Devices requiring high-definition display devices, such as devices for virtual reality (VR), augmented reality (AR), substitutional reality (SR), and mixed reality (MR), are being actively developed.

[0005] As a display device, for example, a light-emitting device having a light-emitting device (also referred to as a light-emitting element) has been developed. A light-emitting device (also referred to as an EL device or an EL element) utilizing an electroluminescence (hereinafter referred to as EL) phenomenon has features such as being easily thin and lightweight, being capable of high-speed response to an input signal, and being capable of being driven by a DC constant voltage power supply, and is therefore applied to a display device.

[0006] Patent Document 1 discloses a display device for VR that uses an organic EL device (also called an organic EL element).

[0007] International Publication No. 2018 / 087625

[0008] Depending on the configuration of the display device, color misalignment may occur between display at low luminance and display at high luminance. Furthermore, increasing the resolution of a display device may cause crosstalk (unintended light emission due to current flowing between adjacent subpixels). Therefore, one object of one embodiment of the present invention is to provide a display device with high display quality. Another object of one embodiment of the present invention is to provide a display device with little color change between display at low luminance and display at high luminance.

[0009] Another object of one embodiment of the present invention is to provide a high-resolution display device.Another object of one embodiment of the present invention is to provide a highly reliable display device.

[0010] An object of one embodiment of the present invention is to provide a method for manufacturing a high-resolution display device.An object of one embodiment of the present invention is to provide a method for manufacturing a high-resolution display device.An object of one embodiment of the present invention is to provide a method for manufacturing a highly reliable display device.An object of one embodiment of the present invention is to provide a method for manufacturing a display device with high yield.

[0011] Note that the description of these problems does not preclude the existence of other problems. One embodiment of the present invention does not necessarily have to solve all of these problems. Problems other than these can be extracted from the description in the specification, drawings, and claims.

[0012] One embodiment of the present invention provides a display portion capable of full-color display, the display portion including a first subpixel, the first subpixel including a first light-emitting device and a first coloring layer that transmits blue light, the first light-emitting device including a first pixel electrode, a first EL layer over the first pixel electrode, and a common electrode over the first EL layer, the first EL layer including a first light-emitting material that emits blue light and a second light-emitting material that emits light having a wavelength longer than blue, The L layer has a first light-emitting unit on the first pixel electrode, a charge generation layer on the first light-emitting unit, and a second light-emitting unit on the charge generation layer, and when the display section displays blue at a first luminance, the intensity of a first light-emitting peak at a wavelength of 400 nm or more and less than 500 nm in the emission spectrum is set to 1, and the intensity of a second light-emitting peak at a wavelength of 500 nm or more and 700 nm or less in the emission spectrum is 0.5 or less, and the first luminance is 0 cd / m ２ Higher than 1cd / m ２ The display device is a display device having a value less than or equal to

[0013] The display unit preferably further includes a second subpixel having a second light-emitting device and a second colored layer that transmits light of a color different from that of the first colored layer. The second light-emitting device preferably includes a second pixel electrode, a second EL layer on the second pixel electrode, and a common electrode on the second EL layer. The first EL layer and the second EL layer preferably have the same configuration. The first EL layer and the second EL layer are preferably separated from each other.

[0014] Another embodiment of the present invention includes a display portion capable of full-color display, the display portion including a first subpixel and a second subpixel, the first subpixel including a first light-emitting device and a first coloring layer that transmits blue light, the second subpixel including a second light-emitting device and a second coloring layer that transmits light of a color different from that of the first coloring layer, the first light-emitting device including a first pixel electrode, a first EL layer over the first pixel electrode, and a common electrode over the first EL layer, and the second light-emitting device including a second pixel electrode and a second pixel electrode. the first EL layer has a first light-emitting unit on the first pixel electrode, a charge generation layer on the first light-emitting unit, and a second light-emitting unit on the charge generation layer, and when the display unit displays blue at a first luminance, the intensity of a first emission peak at a wavelength of 400 nm or more and less than 500 nm in the emission spectrum is set to 1, the intensity of a second emission peak at a wavelength of 500 nm or more and 700 nm or less in the emission spectrum is 0.5 or less, and the first luminance is 0 cd / m ２ Higher than 1cd / m ２ The display device is a display device having a value less than or equal to

[0015] Another embodiment of the present invention includes a display portion capable of full-color display, the display portion including a first subpixel and a second subpixel. The first subpixel includes a first light-emitting device and a first coloring layer that transmits blue light. The second subpixel includes a second light-emitting device and a second coloring layer that transmits light of a color different from that of the first coloring layer. The first light-emitting device includes a first pixel electrode, a first EL layer over the first pixel electrode, and a common electrode over the first EL layer. The second light-emitting device includes a second pixel electrode, a second EL layer over the second pixel electrode, and a common electrode over the second EL layer. the first EL layer and the second EL layer have the same structure and are separated from each other; the first EL layer has a first light-emitting unit on a first pixel electrode, a charge generation layer on the first light-emitting unit, and a second light-emitting unit on the charge generation layer; and when the display unit displays blue at a first luminance, the intensity of a first emission peak at a wavelength of 400 nm or more and less than 500 nm in the emission spectrum is set to 1, and the intensity of a second emission peak at a wavelength of 500 nm or more and 700 nm or less in the emission spectrum is 0.5 or less; and the first luminance is 0 cd / m ２ Higher than 1cd / m ２ The display device is a display device having a value less than or equal to

[0016] The first light-emitting device has a common layer between the first EL layer and the common electrode, and the second light-emitting device has a common layer between the second EL layer and the common electrode, and the common layer preferably has at least one of a hole injection layer, a hole transport layer, a hole blocking layer, an electron blocking layer, an electron transport layer, and an electron injection layer.

[0017] The display unit preferably includes a first insulating layer that covers a side surface of the first EL layer and a side surface of the second EL layer, and the common electrode is preferably located on the first insulating layer. The first insulating layer is also preferably in contact with a side surface of the first pixel electrode and a side surface of the second pixel electrode.

[0018] It is preferable that the display unit has a second insulating layer, the first insulating layer has an inorganic material, and the second insulating layer has an organic material, and that the side surfaces of the first EL layer and the second EL layer are covered via the first insulating layer.

[0019] The resolution of the display unit is preferably 1000 ppi or more, 2000 ppi or more, 3000 ppi or more, 5000 ppi or more, or 6000 ppi or more, and 20000 ppi or less, or 30000 ppi or less.

[0020] The first subpixel preferably includes a lens that overlaps the first light-emitting device and the first colored layer.

[0021] The first pixel electrode preferably comprises a material that reflects visible light.

[0022] Preferably, the first subpixel has a reflective layer, the first pixel electrode has a material that transmits visible light, and the first pixel electrode is located between the reflective layer and the first EL layer.

[0023] One embodiment of the present invention is a display module including a display device having any of the above structures, and including a connector such as a flexible printed circuit (FPC) or a tape carrier package (TCP) attached thereto, or a display module including an integrated circuit (IC) mounted thereon by a chip-on-glass (COG) method, a chip-on-film (COF) method, or the like.

[0024] One embodiment of the present invention is an electronic device including the above-described display module and at least one of a housing, a battery, a camera, a speaker, and a microphone.

[0025] According to one embodiment of the present invention, a display device with high display quality can be provided. According to one embodiment of the present invention, a display device with little change in color between low luminance display and high luminance display can be provided. According to one embodiment of the present invention, a high-definition display device can be provided. According to one embodiment of the present invention, a high-resolution display device can be provided. According to one embodiment of the present invention, a highly reliable display device can be provided.

[0026] According to one embodiment of the present invention, a method for manufacturing a high-resolution display device can be provided. According to one embodiment of the present invention, a method for manufacturing a high-resolution display device can be provided. According to one embodiment of the present invention, a method for manufacturing a highly reliable display device can be provided. According to one embodiment of the present invention, a method for manufacturing a display device with high yield can be provided.

[0027] Note that the description of these effects does not preclude the existence of other effects. One embodiment of the present invention does not necessarily have all of these effects. Effects other than these can be extracted from the description in the specification, drawings, and claims.

[0028] FIG. 1A is a top view showing an example of a display device. FIG. 1B is a cross-sectional view showing an example of a display device. FIGS. 2A to 2C are cross-sectional views showing an example of a display device. FIGS. 3A to 3C are cross-sectional views showing an example of a display device. FIG. 4 is a cross-sectional view showing an example of a display device. FIGS. 5A to 5C are cross-sectional views showing an example of a display device. FIGS. 6A to 6F are cross-sectional views showing an example of a display device. FIGS. 7A to 7D are cross-sectional views showing an example of a manufacturing method of a display device. FIGS. 8A to 8C are cross-sectional views showing an example of a manufacturing method of a display device. FIGS. 9A to 9F are top views showing an example of a pixel. FIGS. 10A to 10H are top views showing an example of a pixel. FIGS. 11A to 11J are top views showing an example of a pixel. FIG. 12 is a perspective view showing an example of a display device. FIG. 13A is a cross-sectional view showing an example of a display device. FIGS. 13B and 13C are cross-sectional views showing an example of a transistor. FIG. 14 is a cross-sectional view showing an example of a display device. FIGS. 15A to 15D are cross-sectional views showing an example of a display device. FIGS. 16A and 16B are perspective views showing an example of a display module. FIGS. 17A to 17C are cross-sectional views showing an example of a display device. FIG. 18 is a cross-sectional view showing an example of a display device. FIG. 19 is a cross-sectional view showing an example of a display device. FIG. 20 is a cross-sectional view showing an example of a display device. FIG. 21 is a cross-sectional view showing an example of a display device. FIG. 22 is a cross-sectional view showing an example of a display device. FIGS. 23A to 23F are diagrams showing an example of the configuration of a light-emitting device. FIGS. 24A to 24D are diagrams showing an example of an electronic device. FIGS. 25A to 25F are diagrams showing an example of an electronic device. FIGS. 26A to 26G are diagrams showing an example of an electronic device. FIGS. 27A to 27F are diagrams showing an example of an electronic device. FIGS. 28A to 28C are chromaticity diagrams of the display device. FIGS. 29A and 29B are measurement results of the emission spectrum of the display device. FIGS. 30A and 30B are measurement results of the emission spectrum of the display device. FIGS. 31A and 31B are measurement results of the emission spectrum of the display device. FIG. 32 is a chromaticity diagram of the display device. 33A and 33B show the measurement results of the emission spectrum of the display device.

[0029] The embodiments will be described in detail with reference to the drawings. However, the present invention is not limited to the following description, and it will be readily understood by those skilled in the art that various changes can be made in form and detail without departing from the spirit and scope of the present invention. Therefore, the present invention should not be interpreted as being limited to the description of the embodiments shown below.

[0030] In the configuration of the invention described below, the same parts or parts having similar functions are denoted by the same reference numerals in different drawings, and repeated explanations thereof will be omitted. Furthermore, when referring to similar functions, the same hatching pattern may be used and no particular reference numeral may be assigned.

[0031] Furthermore, for ease of understanding, the position, size, range, etc. of each component shown in the drawings may not represent the actual position, size, range, etc. Therefore, the disclosed invention is not necessarily limited to the position, size, range, etc. disclosed in the drawings.

[0032] The terms "film" and "layer" can be interchangeable depending on the circumstances. For example, the term "conductive layer" can be changed to the term "conductive film." Or, for example, the term "insulating film" can be changed to the term "insulating layer."

[0033] In this specification, etc., a device fabricated using a metal mask or an FMM (fine metal mask, high-resolution metal mask) may be referred to as a device with an FMM structure or a device with an MM (metal mask) structure. Also, in this specification, etc., a device fabricated without using a metal mask or an FMM may be referred to as a device with an MML (metal maskless) structure.

[0034] Embodiment 1 In this embodiment, a display device according to one embodiment of the present invention and a manufacturing method thereof will be described with reference to FIGS.

[0035] One embodiment of the present invention is a display device having a display portion capable of full-color display. A subpixel emitting blue light in the display portion includes a light-emitting device and a colored layer transmitting blue light. The light-emitting device includes a pixel electrode, an EL layer over the pixel electrode, and a common electrode over the EL layer. The EL layer includes a light-emitting material emitting blue light and a light-emitting material emitting light with a wavelength longer than blue. The EL layer includes a first light-emitting unit over the pixel electrode, a charge generation layer over the first light-emitting unit, and a second light-emitting unit over the charge generation layer. That is, the display device of one embodiment of the present invention uses a light-emitting device having a tandem structure including multiple light-emitting units. Note that the display portion capable of full-color display includes at least a subpixel emitting blue light and two or more subpixels emitting light of a color other than blue. Examples of blue light include light with a peak wavelength of 400 nm or more and less than 500 nm.

[0036] In the display device of one embodiment of the present invention, when the display portion displays blue at a first luminance, the intensity of a first emission peak having a wavelength of 400 nm or more and less than 500 nm in the emission spectrum is set to 1, the intensity of a second emission peak having a wavelength of 500 nm or more and less than 700 nm in the emission spectrum is set to 0 or more and 0.5 or less, and the first luminance is 0 cd / m ２ Higher than 1cd / m ２ That is, when the display device of one embodiment of the present invention displays blue light at low luminance, blue light is mainly observed, and light with a wavelength longer than blue is hardly observed (including a case where it is not substantially observed).

[0037] In a light-emitting device with a single structure (a structure having only one light-emitting unit) having multiple light-emitting layers, it is difficult to adjust the carrier balance, and the emission color may change between low and high luminance. On the other hand, in a light-emitting device with a tandem structure, it is easier to adjust the carrier balance than in a light-emitting device with a single structure, and the emission color is less likely to change between low and high luminance. Therefore, the display device of one embodiment of the present invention can achieve high display quality with little color change between low and high luminance display.

[0038] In a display device according to one embodiment of the present invention, each subpixel includes a light-emitting device having an EL layer with the same structure and a colored layer overlapping the light-emitting device, and a full-color display can be achieved by providing a colored layer that transmits visible light of a different color depending on the subpixel.

[0039] When a light-emitting device having an EL layer with the same configuration is used for each subpixel, there is no need to separately coat the light-emitting layer for each subpixel. Therefore, layers other than the pixel electrode (e.g., the light-emitting layer) included in the light-emitting device can be shared (or, more precisely, shared) by multiple subpixels. However, some layers included in the light-emitting device have relatively high conductivity, and providing a highly conductive layer in common with multiple subpixels can cause leakage current between subpixels. In particular, as display devices become higher in resolution or aperture ratio and the distance between subpixels becomes smaller, the leakage current can become significant and may cause degradation of the display quality of the display device. Therefore, in a display device according to one embodiment of the present invention, at least a portion of the layers constituting the EL layer in each subpixel is formed in an island shape. By separating at least a portion of the layers constituting the EL layer for each subpixel, crosstalk between adjacent subpixels can be suppressed. This allows display devices to achieve both high resolution and high display quality.

[0040] For example, island-shaped light-emitting layers can be formed by vacuum deposition using a metal mask. However, this method can result in deviations in the shape and position of the island-shaped light-emitting layers from the design due to various factors, such as the accuracy of the metal mask, misalignment between the metal mask and the substrate, deflection of the metal mask, and the spread of the contours of the formed film due to vapor scattering, making it difficult to achieve high-definition and high-aperture display devices. Furthermore, during deposition, the contours of the layer can become blurred, resulting in thin edges. In other words, the thickness of the island-shaped light-emitting layer can vary depending on the location. Furthermore, when fabricating large, high-resolution, or high-definition display devices, there is a concern that low manufacturing yields may be caused by low dimensional accuracy of the metal mask and deformation due to heat, etc.

[0041] Therefore, when manufacturing a display device according to one embodiment of the present invention, a pixel electrode is formed for each subpixel, and then a light-emitting layer is formed over the plurality of pixel electrodes. Then, the light-emitting layer is processed by, for example, photolithography to form one island-shaped light-emitting layer for each pixel electrode. This allows the light-emitting layer to be divided into subpixels, and an island-shaped light-emitting layer can be formed for each subpixel.

[0042] As described above, the island-shaped light-emitting layer manufactured by the manufacturing method of the display device according to one embodiment of the present invention is not formed using a metal mask having a fine pattern, but is formed by forming a light-emitting layer over the entire surface and then processing it. Specifically, the island-shaped light-emitting layer has a size that is divided and miniaturized using a photolithography method or the like. Therefore, the size of the island-shaped light-emitting layer can be made smaller than that of a layer formed using a metal mask. Therefore, a high-definition display device or a display device with a high aperture ratio, which has been difficult to achieve until now, can be realized.

[0043] In the manufacturing method of a display device according to one embodiment of the present invention, the number of times of processing the light-emitting layer by photolithography can be reduced to one, which is preferable because it can reduce manufacturing costs and improve manufacturing yield.

[0044] While it is difficult to achieve a spacing of less than 10 μm between adjacent light-emitting devices using, for example, a metal mask, the above-described method can narrow the spacing to less than 10 μm, 5 μm or less, 3 μm or less, 2 μm or less, or even 1 μm or less. Furthermore, by using, for example, an exposure device for LSIs, the spacing between adjacent light-emitting devices can be narrowed to 500 nm or less, 200 nm or less, 100 nm or less, or even 50 nm or less. This significantly reduces the area of ​​the non-light-emitting region that may exist between two light-emitting devices, enabling the aperture ratio to approach 100%. For example, the aperture ratio can be 50% or more, 60% or more, 70% or more, 80% or more, or even 90% or more, and even less than 100%.

[0045] Furthermore, the pattern of the light-emitting layer itself (also called the processing size) can be made much smaller than when a metal mask is used. Furthermore, for example, when a metal mask is used to separately fabricate light-emitting layers, thickness variations occur between the center and edges of the light-emitting layer, resulting in a smaller effective area that can be used as a light-emitting region relative to the area of ​​the light-emitting layer. On the other hand, the above-described fabrication method processes a film formed to a uniform thickness, allowing island-shaped light-emitting layers to be formed with a uniform thickness. Therefore, even with a fine pattern, almost the entire area can be used as a light-emitting region. This allows the fabrication of a display device that combines high definition and a high aperture ratio.

[0046] In addition, in a manufacturing method of a display device according to one embodiment of the present invention, it is preferable to form a layer including a light-emitting layer (which can be referred to as an EL layer or a part of an EL layer) over the entire surface, and then form a sacrificial layer (which may also be referred to as a mask layer) over the EL layer. Then, it is preferable to form a resist mask over the sacrificial layer and process the EL layer and the sacrificial layer using the resist mask to form an island-shaped EL layer.

[0047] By providing a sacrificial layer over the EL layer, damage to the EL layer during the manufacturing process of the display device can be reduced, and the reliability of the light-emitting device can be improved.

[0048] The island-shaped EL layer includes at least a light-emitting layer and preferably includes multiple layers. Specifically, it is preferable to have one or more layers on the light-emitting layer. By having another layer between the light-emitting layer and the sacrificial layer, it is possible to prevent the light-emitting layer from being exposed to the outermost surface during the manufacturing process of the display device, thereby reducing damage to the light-emitting layer. This improves the reliability of the light-emitting device. Therefore, it is preferable that each island-shaped EL layer includes a light-emitting layer and a carrier transport layer (electron transport layer or hole transport layer) on the light-emitting layer.

[0049] In a light-emitting device, all layers constituting the EL layer do not need to be formed in an island shape, and some layers can be provided in common (shared) among a plurality of light-emitting devices. Examples of layers included in the EL layer include a light-emitting layer, a carrier injection layer (a hole injection layer and an electron injection layer), a carrier transport layer (a hole transport layer and an electron transport layer), and a carrier blocking layer (a hole blocking layer and an electron blocking layer). In a manufacturing method of a display device according to one embodiment of the present invention, after some layers constituting the EL layer are formed in an island shape for each subpixel, at least a part of the sacrificial layer is removed, and the remaining layers constituting the EL layer (e.g., a carrier injection layer) and a common electrode (which can also be referred to as an upper electrode) can be formed in common among a plurality of light-emitting devices.

[0050] On the other hand, the carrier injection layer is often a layer with relatively high conductivity among EL layers. Therefore, contact of the carrier injection layer with the side surface of the island-shaped EL layer or the side surface of the pixel electrode may cause a short circuit in the light-emitting device. Even when the carrier injection layer is provided in an island shape and a common electrode is formed in common with multiple light-emitting devices, contact of the common electrode with the side surface of the EL layer or the side surface of the pixel electrode may cause a short circuit in the light-emitting device.

[0051] Therefore, a display device according to one embodiment of the present invention includes an insulating layer that covers at least the side surfaces of the island-shaped light-emitting layer.

[0052] This prevents at least a portion of the island-shaped EL layer and the pixel electrode from coming into contact with the carrier injection layer or the common electrode, thereby preventing short circuits in the light-emitting device and improving the reliability of the light-emitting device.

[0053] Furthermore, by providing the insulating layer, the gaps between adjacent island-shaped EL layers can be filled, thereby reducing the unevenness of the surface on which layers (such as a carrier injection layer and a common electrode) are formed on the island-shaped EL layers, making the surface flatter. This improves the coverage of the carrier injection layer or the common electrode, thereby preventing the common electrode from being broken.

[0054] In this specification and the like, the term "step discontinuity" refers to a phenomenon in which a layer, film, or electrode is divided due to the shape of the surface on which it is formed (for example, a step or the like).

[0055] Furthermore, the insulating layer can be provided so as to contact the island-shaped EL layer. This can prevent peeling of the EL layer. The close contact between the insulating layer and the island-shaped EL layer has the effect of fixing or adhering adjacent island-shaped EL layers by the insulating layer. Furthermore, the insulating layer prevents moisture from penetrating the interface between the pixel electrode and the EL layer, thereby preventing peeling of the EL layer. This can improve the reliability of the light-emitting device. Furthermore, the manufacturing yield of the light-emitting device can be increased.

[0056] The insulating layer preferably functions as a barrier insulating layer against at least one of water and oxygen, suppresses diffusion of at least one of water and oxygen, and captures or fixes (also referred to as gettering) at least one of water and oxygen.

[0057] In this specification and the like, a barrier insulating layer refers to an insulating layer having barrier properties. In addition, in this specification and the like, the barrier properties refer to a function of suppressing the diffusion of a corresponding substance (also referred to as low permeability) or a function of capturing or fixing (also referred to as gettering) a corresponding substance.

[0058] By using an insulating layer having a function as a barrier insulating layer or a gettering function, it is possible to suppress the intrusion of impurities (typically, at least one of water and oxygen) that may diffuse into each light-emitting device from the outside. With this configuration, it is possible to provide a highly reliable light-emitting device and further a highly reliable display device.

[0059] A display device according to one embodiment of the present invention includes a pixel electrode, a first light-emitting unit on the pixel electrode, a charge generation layer (also referred to as an intermediate layer) on the first light-emitting unit, a second light-emitting unit on the charge generation layer, insulating layers provided so as to cover side surfaces of the first light-emitting unit, the charge generation layer, and the second light-emitting unit, and a common electrode provided on the second light-emitting unit. Note that a common layer may be provided between the second light-emitting unit and the common electrode for light-emitting devices of each color.

[0060] Among EL layers, the hole injection layer, the electron injection layer, the charge generation layer, and the like are often layers with relatively high conductivity. In the display device of one embodiment of the present invention, the side surfaces of these layers are covered with an insulating layer, so that contact with a common electrode or the like can be suppressed. Therefore, short circuits in the light-emitting device can be suppressed, and the reliability of the light-emitting device can be improved.

[0061] The insulating layer covering the side surfaces of the island-shaped EL layer may have a single layer structure or a multilayer structure.

[0062] For example, by forming an insulating layer having a single layer structure using an inorganic material, the insulating layer can be used as a protective insulating layer for an EL layer, thereby improving the reliability of the display device.

[0063] Furthermore, when using insulating layers with a stacked structure, the first insulating layer is preferably formed using an inorganic insulating material because it is formed in contact with the EL layer. In particular, it is preferable to form the first insulating layer using an atomic layer deposition (ALD) method, which causes less film formation damage. Alternatively, it is preferable to form the inorganic insulating layer using a sputtering method, a chemical vapor deposition (CVD) method, or a plasma enhanced chemical vapor deposition (PECVD) method, which have a faster film formation rate than the ALD method. This allows for the production of a highly reliable display device with high productivity. Furthermore, it is preferable to form the second insulating layer using an organic material so as to planarize the recesses formed in the first insulating layer.

[0064] For example, an aluminum oxide film formed by an ALD method can be used as the first insulating layer, and an organic resin film can be used as the second insulating layer.

[0065] If the side surface of the EL layer and the organic resin film are in direct contact, organic solvents contained in the organic resin film may damage the EL layer. By using an inorganic insulating film such as an aluminum oxide film formed by the ALD method as the first layer of the insulating layer, it is possible to prevent direct contact between the organic resin film and the side surface of the EL layer. This makes it possible to prevent the EL layer from being dissolved by an organic solvent.

[0066] Furthermore, in the display device of one embodiment of the present invention, since there is no need to provide an insulating layer between the pixel electrode and the EL layer to cover the edge of the pixel electrode, the distance between adjacent light-emitting devices can be made extremely narrow. Therefore, the display device can have high definition or high resolution. Furthermore, a mask for forming the insulating layer is not required, which reduces the manufacturing cost of the display device.

[0067] Furthermore, by using a structure in which an insulating layer covering an edge of the pixel electrode is not provided between the pixel electrode and the EL layer, in other words, by using a structure in which an insulating layer is not provided between the pixel electrode and the EL layer, light from the EL layer can be efficiently extracted. Therefore, the display device of one embodiment of the present invention can have extremely low viewing angle dependence. By reducing the viewing angle dependence, the visibility of images in the display device can be improved. For example, in the display device of one embodiment of the present invention, the viewing angle (the maximum angle at which a certain contrast ratio is maintained when the screen is viewed from an oblique direction) can be set to a range of 100° to less than 180°, preferably 150° to 170°. Note that the above viewing angle can be applied to both the vertical and horizontal directions.

[0068] Furthermore, the configuration for suppressing crosstalk is not limited to the configuration in which an island-shaped EL layer is formed for each light-emitting device. For example, crosstalk can also be suppressed by applying a configuration in which a region with a thin EL layer is formed between adjacent light-emitting devices. The presence of a region with a thin EL layer between adjacent light-emitting devices can suppress current flow outside the region of the EL layer that contacts the pixel electrode. Furthermore, the region of the EL layer that contacts the pixel electrode can be used mainly as the light-emitting region.

[0069] For example, with respect to the thickness T1 of the pixel electrode and the thickness T2 of the EL layer, the ratio T1 / T2 is preferably 0.5 or greater, more preferably 0.8 or greater, more preferably 1.0 or greater, and even more preferably 1.5 or greater. Furthermore, when a recess is provided in the insulating layer constituting the surface on which the pixel electrode is formed in the region between adjacent light-emitting devices (see, for example, the insulating layer 255b (FIG. 17A) described in the third embodiment below), the thickness T1 of the pixel electrode may be thin. Specifically, with respect to the sum T3 of the thickness of the pixel electrode and the depth of the recess, and the thickness T2 of the EL layer, the ratio T3 / T2 is preferably 0.5 or greater, more preferably 0.8 or greater, more preferably 1.0 or greater, and even more preferably 1.5 or greater. By satisfying the above relationship between T1 and T2 or T2 and T3, it becomes easy to form a region with a thin EL layer between adjacent light-emitting devices. Furthermore, the formation of an extremely thin region in the EL layer may result in a partial separation of the EL layer.

[0070] Furthermore, it is preferable that the thickness T1 of the pixel electrode or the sum T3 be, for example, 160 nm or more, 200 nm or more, or 250 nm or more, and 1000 nm or less, 750 nm or less, 500 nm or less, 400 nm or less, or 300 nm or less.

[0071] The angle (also referred to as the taper angle) between the side surface of the pixel electrode and the surface on which it is formed is preferably 60° to 140°, more preferably 70° to 140°, and even more preferably 80° to 140°. When the taper angle of the pixel electrode satisfies the above range, it becomes easy to form a region in which the thickness of the EL layer is thin between adjacent light-emitting devices.

[0072] [Structure Example of Display Device] FIGS. 1 and 2 illustrate a display device according to one embodiment of the present invention.

[0073] FIG. 1A shows a top view of a display device 100. The display device 100 has a display section in which a plurality of pixels 103 are arranged, and a connection section 140 outside the display section. A plurality of sub-pixels are arranged in a matrix in the display section. FIG. 1A shows two rows and six columns of sub-pixels, which together form a two-row, two-column pixel. The connection section 140 can also be called a cathode contact section.

[0074] The pixel 103 shown in FIG. 1A is composed of three subpixels: a subpixel 110R, a subpixel 110G, and a subpixel 110B.

[0075] The sub-pixel 110R emits red light, the sub-pixel 110G emits green light, and the sub-pixel 110B emits blue light. In this embodiment, sub-pixels of three colors, red (R), green (G), and blue (B), are described as an example, but sub-pixels of three colors, yellow (Y), cyan (C), and magenta (M), may also be used. The number of types of sub-pixels is not limited to three, and may be four or more. Examples of four sub-pixels include sub-pixels of four colors, R, G, B, and white (W); sub-pixels of four colors, R, G, B, and Y; and sub-pixels of R, G, B, and infrared (IR).

[0076] It can also be said that a stripe arrangement is applied to the pixel 103 shown in FIG. 1A.

[0077] In this specification and the like, the row direction may be referred to as the X direction, and the column direction may be referred to as the Y direction. The X direction and the Y direction intersect, for example, perpendicularly (see FIG. 1A).

[0078] 1A shows an example in which subpixels of different colors are arranged side by side in the X direction, and subpixels of the same color are arranged side by side in the Y direction. Note that subpixels of different colors may also be arranged side by side in the Y direction, and subpixels of the same color may also be arranged side by side in the X direction.

[0079] 1A shows an example in which the connection unit 140 is located below the display unit when viewed from above, but this is not particularly limited. The connection unit 140 only needs to be located in at least one of the upper, right, left, and lower sides of the display unit when viewed from above, and may be located so as to surround all four sides of the display unit. The top surface shape of the connection unit 140 may be strip-shaped, L-shaped, U-shaped, frame-shaped, or the like. Furthermore, the connection unit 140 may be singular or plural.

[0080] Fig. 1B shows a cross-sectional view taken along dashed lines A1-A2 in Fig. 1A. Fig. 2A shows a cross-sectional view taken along dashed lines B1-B2 in Fig. 1A. Fig. 2B and Fig. 2C show cross-sectional views taken along dashed lines C1-C2 in Fig. 1A.

[0081] 1B and 2A, display device 100 has light-emitting devices 130 provided on layer 101 including transistors, and protective layer 131 provided to cover these light-emitting devices. Colored layers 132R, 132G, and 132B are provided on protective layer 131, and substrate 120 is bonded thereto by resin layer 122. In addition, insulating layer 125 and insulating layer 127 on insulating layer 125 are provided in the regions between adjacent light-emitting devices.

[0082] 1B and 2A, etc. show that a plurality of insulating layers 125 and insulating layers 127 are provided, but when the display device 100 is viewed from above, the insulating layers 125 and insulating layers 127 may each be configured to be connected to one another. That is, the display device 100 may be configured to have, for example, one insulating layer 125 and one insulating layer 127. Note that the display device 100 may have a plurality of insulating layers 125 that are separated from one another, or may have a plurality of insulating layers 127 that are separated from one another.

[0083] The display device of one embodiment of the present invention may be any of a top-emission type that emits light in a direction opposite to the substrate on which the light-emitting device 130 is formed, a bottom-emission type that emits light toward the substrate on which the light-emitting device 130 is formed, and a dual-emission type that emits light to both sides.

[0084] The transistor-containing layer 101 may have, for example, a stacked structure in which a plurality of transistors are provided on a substrate and an insulating layer is provided to cover these transistors. The transistor-containing layer 101 may have a recess between adjacent light-emitting devices 130. For example, a recess may be provided in an insulating layer located on the outermost surface of the transistor-containing layer 101. Configuration examples of the transistor-containing layer 101 will be described later in Embodiments 2 and 3.

[0085] Each of the light-emitting devices 130 in each subpixel has an EL layer 113 and a common layer 114. The common layer 114 can also be considered to be part of the EL layer in the light-emitting device. In this specification and the like, among the EL layers in the light-emitting devices, a layer provided in an island shape for each light-emitting device is referred to as the EL layer 113, and a layer shared by multiple light-emitting devices is referred to as the common layer 114.

[0086] The plurality of EL layers 113 are each provided in an island shape. The plurality of EL layers 113 can all have the same structure.

[0087] For example, the EL layer 113 can have a light-emitting material that emits blue light and a light-emitting material that emits light with a wavelength longer than blue. For example, the EL layer 113 can have a structure including a light-emitting material that emits blue light and a light-emitting material that emits yellow light, or a structure including a light-emitting material that emits blue light, a light-emitting material that emits green light, and a light-emitting material that emits red light.

[0088] The EL layer 113 has a plurality of light-emitting units. In this embodiment, an example in which the EL layer 113 has two light-emitting units is shown. Specifically, the EL layer 113 has a first light-emitting unit 113 a, a charge generation layer 113 b, and a second light-emitting unit 113 c.

[0089] Each light-emitting unit has a light-emitting layer. For example, if the light-emitting units emit complementary colors of light, the light-emitting device 130 can emit white light.

[0090] By applying a microcavity structure, which will be described later, the light emitting device 130 configured to emit white light may emit light with a particular color, such as red, green, or blue, enhanced.

[0091] As the light-emitting device 130, it is preferable to use an EL device such as an OLED (organic light-emitting diode) or a QLED (quantum-dot light-emitting diode). Examples of light-emitting substances (also referred to as light-emitting materials) included in the EL device include fluorescent materials, phosphorescent materials, and thermally activated delayed fluorescence (TADF materials). Note that the TADF material may be a material that is in thermal equilibrium between a singlet excited state and a triplet excited state. Such TADF materials have a short emission lifetime (excitation lifetime), which can suppress a decrease in efficiency in the high-brightness region of the light-emitting device. Furthermore, an inorganic compound (for example, a quantum dot material) may be used as the light-emitting material of the EL device.

[0092] The light-emitting device 130 has an EL layer between a pair of electrodes. The EL layer has at least a light-emitting layer. In this specification and the like, one of the pair of electrodes may be referred to as a pixel electrode, and the other as a common electrode.

[0093] Of the pair of electrodes that a light-emitting device has, one electrode functions as an anode and the other electrode functions as a cathode. In the following, an example in which the pixel electrode functions as the anode and the common electrode functions as the cathode will be described.

[0094] The light-emitting device 130 has a pixel electrode 111 on a layer 101 including transistors, an island-shaped EL layer 113 on the pixel electrode 111 , a common layer 114 on the EL layer 113 , and a common electrode 115 on the common layer 114 .

[0095] The EL layer 113 includes at least a light-emitting layer and may include one or more of a hole-injection layer, a hole-transport layer, a hole-blocking layer, a charge-generating layer, an electron-blocking layer, an electron-transporting layer, and an electron-injection layer.

[0096] The first light-emitting unit 113a and the second light-emitting unit 113c each include at least a light-emitting layer, and may also include one or more of a hole-injection layer, a hole-transport layer, a hole-blocking layer, an electron-blocking layer, an electron-transporting layer, and an electron-injection layer.

[0097] The common layer 114 includes, for example, an electron injection layer or a hole injection layer. Alternatively, the common layer 114 may include a stack of an electron transport layer and an electron injection layer, or a stack of a hole transport layer and a hole injection layer. The common layer 114 is shared by the plurality of light-emitting devices 130, for example, by all of the light-emitting devices 130.

[0098] The light emitting device of the present embodiment has a tandem structure. In the present embodiment, an example in which the light emitting device has two light emitting units is shown, but the number of light emitting units in the light emitting device may be three or more.

[0099] The common electrode 115 is shared by the plurality of light-emitting devices 130, for example, by all of the light-emitting devices 130. The common electrode 115 shared by the plurality of light-emitting devices 130 is electrically connected to a conductive layer 123 provided in the connection portion 140 (see FIGS. 2B and 2C ). The conductive layer 123 may be formed from the same material and in the same process as the pixel electrode 111.

[0100] 2B shows an example in which the common layer 114 is provided over the conductive layer 123, and the conductive layer 123 and the common electrode 115 are electrically connected to each other through the common layer 114. The common layer 114 does not have to be provided in the connection portion 140. For example, FIG. 2C shows an example in which the common layer 114 is not provided over the conductive layer 123, and the conductive layer 123 and the common electrode 115 are directly connected to each other. For example, by using a mask (also referred to as an area mask or a rough metal mask) for defining a deposition area, the regions where the common layer 114 and the common electrode 115 are deposited can be changed.

[0101] The size relationship between the pixel electrode 111 and the EL layer 113 is not particularly limited. FIGS. 1B and 2A show an example in which the end of the EL layer 113 is located more inward than the end of the pixel electrode 111. FIG. 3A shows an enlarged view of the light-emitting device shown in FIGS. 1B and 2A. In FIG. 3A, the end of the EL layer 113 is located on the pixel electrode 111. FIG. 3A shows an example in which the EL layer 113 is located in the center of the pixel electrode 111, and the width X1 of the left region of the pixel electrode 111 where the EL layer 113 does not overlap is equal to or approximately equal to the width X2 of the right region. Alternatively, the EL layer 113 may be disposed closer to either end of the pixel electrode 111. FIG. 3B shows an example in which the EL layer 113 is disposed closer to the right end of the pixel electrode 111, and the width X2 is narrower than the width X1.

[0102] Furthermore, the end of the EL layer 113 may have both a portion located outside the end of the pixel electrode 111 and a portion located inside the end of the pixel electrode 111. In Fig. 3C , the end of the EL layer 113 is located outside the end of the pixel electrode 111 and covers the end of the pixel electrode 111. Specifically, Fig. 3C shows an example in which the left end of the EL layer 113 is located inside the left end of the pixel electrode 111, and the right end of the EL layer 113 covers the right end of the pixel electrode 111.

[0103] 4 shows an example in which the edge of the EL layer 113 is positioned outside the edge of the pixel electrode 111. In FIG.

[0104] Furthermore, the edge of the pixel electrode 111 and the edge of the EL layer 113 may be aligned or approximately aligned.

[0105] In addition, when the edges are aligned or approximately aligned, and when the top surface shapes are the same or approximately aligned, it can be said that at least a portion of the contours of the stacked layers overlap when viewed from above. For example, this includes cases where the upper and lower layers are processed using the same mask pattern or a portion of the same mask pattern. However, strictly speaking, the contours may not overlap, and the upper layer may be located inside the lower layer, or outside the lower layer. In these cases, it is also said that the edges are approximately aligned, or the top surface shapes are approximately aligned.

[0106] The edge of the pixel electrode 111 may have a tapered shape. By tapering the side surface of the pixel electrode 111, coverage of the insulating layer 125 provided along the side surface of the pixel electrode 111 can be improved. Furthermore, by tapering the side surface of the pixel electrode 111, foreign matter (for example, dust or particles) during the manufacturing process can be easily removed by a process such as cleaning, which is preferable.

[0107] It is preferable to have a protective layer 131 on the light-emitting device 130. The reliability of the light-emitting device can be improved by providing the protective layer 131. The protective layer 131 may have a single-layer structure or a stacked structure of two or more layers.

[0108] There is no restriction on the conductivity of the protective layer 131. The protective layer 131 can be made of at least one of an insulating film, a semiconductor film, and a conductive film.

[0109] The protective layer 131 has an inorganic film, which prevents oxidation of the common electrode 115 and prevents impurities (moisture, oxygen, etc.) from entering the light-emitting device 130, thereby suppressing deterioration of the light-emitting device and improving the reliability of the display device.

[0110] The protective layer 131 can be made of an inorganic insulating film such as an oxide insulating film, a nitride insulating film, an oxynitride insulating film, or a nitride oxide insulating film. Examples of oxide insulating films include a silicon oxide film, an aluminum oxide film, a gallium oxide film, a germanium oxide film, an yttrium oxide film, a zirconium oxide film, a lanthanum oxide film, a neodymium oxide film, a hafnium oxide film, and a tantalum oxide film. Examples of nitride insulating films include a silicon nitride film and an aluminum nitride film. Examples of oxynitride insulating films include a silicon oxynitride film and an aluminum oxynitride film. Examples of nitride oxide insulating films include a silicon nitride oxide film and an aluminum nitride oxide film.

[0111] The protective layer 131 preferably includes an insulating nitride film or an insulating nitride oxide film, and more preferably includes an insulating nitride film.

[0112] Alternatively, an inorganic film containing In—Sn oxide (also referred to as ITO), In—Zn oxide, Ga—Zn oxide, Al—Zn oxide, indium gallium zinc oxide (In—Ga—Zn oxide, also referred to as IGZO), or the like can be used for the protective layer 131. The inorganic film preferably has high resistance, specifically, preferably has higher resistance than the common electrode 115. The inorganic film may further contain nitrogen.

[0113] When light emitted from the light-emitting device is extracted through the protective layer 131, it is preferable that the protective layer 131 has high transparency to visible light. For example, ITO, IGZO, and aluminum oxide are preferable because they are inorganic materials that have high transparency to visible light.

[0114] For example, a stacked structure of an aluminum oxide film and a silicon nitride film on the aluminum oxide film, or a stacked structure of an aluminum oxide film and an IGZO film on the aluminum oxide film can be used as the protective layer 131. By using such a stacked structure, impurities (water, oxygen, etc.) can be prevented from entering the EL layer side.

[0115] Furthermore, the protective layer 131 may include an organic film. For example, the protective layer 131 may include both an organic film and an inorganic film.

[0116] The protective layer 131 may have a two-layer structure formed by using different film formation methods. Specifically, the first layer of the protective layer 131 may be formed by the ALD method, and the second layer of the protective layer 131 may be formed by the sputtering method.

[0117] In the subpixel 110R, a colored layer 132R that transmits red light is provided on the protective layer 131. As a result, in the subpixel 110R, light emitted from the light-emitting device 130 is extracted as red light to the outside of the display device 100 via the colored layer 132R. Note that the colored layer 132R may be shared by a plurality of adjacent subpixels 110R. Alternatively, one colored layer 132R may be provided independently for each subpixel 110R.

[0118] Similarly, in the subpixel 110G, a colored layer 132G that transmits green light is provided on the protective layer 131. As a result, in the subpixel 110G, light emitted from the light-emitting device 130 is extracted as green light to the outside of the display device 100 via the colored layer 132G.

[0119] In addition, in the subpixel 110B, a colored layer 132B that transmits blue light is provided on the protective layer 131. As a result, in the subpixel 110B, light emitted from the light-emitting device 130 is extracted as blue light to the outside of the display device 100 via the colored layer 132B.

[0120] 1B and 2A show an example in which colored layers 132R, 132G, and 132B are provided directly on the light-emitting device 130 via a protective layer 131. This configuration can improve the accuracy of alignment between the light-emitting device 130 and the colored layers. Furthermore, by positioning the light-emitting device 130 and the colored layers closer to each other, color mixing can be suppressed and viewing angle characteristics can be improved, which is preferable.

[0121] 5A, the substrate 120 provided with the colored layers 132R, 132G, and 132B may be bonded to the protective layer 131 with a resin layer 122. By providing the colored layers 132R, 132G, and 132B on the substrate 120, the temperature of the heat treatment in the formation process of these layers can be increased.

[0122] Although not shown, an insulating layer may be provided to cover the upper end of the pixel electrode 111. The EL layer 113 may have a portion in contact with the pixel electrode 111 and a portion in contact with the insulating layer. The insulating layer may have a single layer structure or a multilayer structure using one or both of an inorganic insulating film and an organic insulating film.

[0123] Examples of organic insulating materials that can be used for the insulating layer covering the end of the pixel electrode 111 include acrylic resin, epoxy resin, polyimide resin, polyamide resin, polyimideamide resin, polysiloxane resin, benzocyclobutene resin, and phenol resin. In addition, as an inorganic insulating film that can be used for the insulating layer, the inorganic insulating film that can be used for the protective layer 131 can be used.

[0124] When an inorganic insulating film is used as the insulating layer covering the edge of the pixel electrode 111, impurities are less likely to enter the light-emitting device 130 than when an organic insulating film is used, thereby improving the reliability of the light-emitting device 130. When an organic insulating film is used as the insulating layer covering the edge of the pixel electrode 111, step coverage is better and the insulating layer is less affected by the shape of the pixel electrode than when an inorganic insulating film is used. Therefore, short circuits in the light-emitting device 130 can be prevented. Specifically, when an organic insulating film is used as the insulating layer, the insulating layer can be processed into a tapered shape or the like. In this specification, a tapered shape refers to a shape in which at least a portion of the side surface of the structure is inclined with respect to the substrate surface or the surface on which the structure is to be formed. For example, it is preferable to have a region in which the angle (also referred to as the taper angle) between the inclined side surface and the substrate surface or the surface on which the structure is to be formed is less than 90°.

[0125] The side surfaces of the pixel electrode 111 and the EL layer 113 are covered with the insulating layer 125 and the insulating layer 127. This prevents the common layer 114 (or the common electrode 115) from coming into contact with the side surfaces of the pixel electrode 111 and the EL layer 113, thereby preventing short circuits in the light-emitting device. This improves the reliability of the light-emitting device.

[0126] The insulating layer 125 preferably covers at least one of the side surfaces of the pixel electrode 111 and the EL layer 113, and more preferably covers both the side surfaces of the pixel electrode 111 and the EL layer 113. The insulating layer 125 can be configured to be in contact with each of the side surfaces of the pixel electrode 111 and the EL layer 113.

[0127] The insulating layer 127 is provided on the insulating layer 125 so as to fill the recesses of the insulating layer 125. The insulating layer 127 can be configured to overlap with the side surfaces of the pixel electrode 111 and the EL layer 113 (which can also be said to be a configuration covering the side surfaces) via the insulating layer 125.

[0128] By providing the insulating layers 125 and 127, the gaps between adjacent island-shaped layers can be filled, which reduces the unevenness of the surface on which a layer (for example, a common electrode) is formed on the island-shaped layers, making the surface flatter. Therefore, coverage of the common electrode can be improved, and step disconnection of the common electrode can be prevented.

[0129] The common layer 114 and the common electrode 115 are provided over the EL layer 113, the insulating layer 125, and the insulating layer 127. Before the insulating layer 125 and the insulating layer 127 are provided, a step is generated between a region where the pixel electrode 111 and the EL layer 113 are provided and a region where the pixel electrode 111 and the EL layer 113 are not provided (a region between light-emitting devices). The display device of one embodiment of the present invention includes the insulating layer 125 and the insulating layer 127, which can flatten the step and improve the coverage of the common layer 114 and the common electrode 115. Therefore, poor connection due to a step in the common electrode 115 can be suppressed. Furthermore, the step can suppress an increase in electrical resistance due to a local thinning of the common electrode 115.

[0130] In order to improve the flatness of the surfaces on which the common layer 114 and the common electrode 115 are formed, it is preferable that the heights of the upper surfaces of the insulating layers 125 and 127 are the same as or approximately the same as the height of the upper surfaces at the ends of the EL layer 113 (which can also be said to be the height of the ends of the upper surface of the EL layer 113). Furthermore, it is preferable that the upper surface of the insulating layer 127 has a flat shape, but it may have a convex portion, a convex curved surface, a concave curved surface, or a concave portion.

[0131] Furthermore, the insulating layer 125 or the insulating layer 127 can be provided so as to be in contact with the island-shaped EL layer 113. When the insulating layer 125 or the insulating layer 127 is in close contact with the EL layer 113, the adjacent EL layers 113 are fixed or bonded by the insulating layer 125 or the insulating layer 127. This can prevent the EL layer 113 from peeling off, thereby improving the reliability of the light-emitting device. Furthermore, the manufacturing yield of the light-emitting device can be increased.

[0132] Note that either the insulating layer 125 or the insulating layer 127 does not necessarily have to be provided. For example, by forming the insulating layer 125 to have a single-layer structure using an inorganic material, the insulating layer 125 can be used as a protective insulating layer for the EL layer 113. This can improve the reliability of the display device. Furthermore, by forming the insulating layer 127 to have a single-layer structure using an organic material, for example, the insulating layer 127 can fill the gap between adjacent EL layers 113 and achieve planarization. This can improve the coverage of the common electrode 115 (upper electrode) formed over the EL layer 113 and the insulating layer 127.

[0133] 5B shows an example in which the insulating layer 125 is not provided. When the insulating layer 125 is not provided, the insulating layer 127 can be configured to be in contact with each side surface of the pixel electrode 111 and the EL layer 113. The insulating layer 127 can be provided so as to fill the spaces between the EL layers 113 of the light-emitting devices 130.

[0134] In this case, it is preferable to use an organic material for the insulating layer 127 that causes less damage to the EL layer 113. For example, it is preferable to use an organic material such as polyvinyl alcohol (PVA), polyvinyl butyral, polyvinyl pyrrolidone, polyethylene glycol, polyglycerin, pullulan, water-soluble cellulose, or alcohol-soluble polyamide resin for the insulating layer 127.

[0135] FIG. 5C shows an example in which the insulating layer 127 is not provided.

[0136] Although FIG. 5C shows an example in which the common layer 114 is embedded in the recess of the insulating layer 125, a gap may be formed in this region.

[0137] The insulating layer 125 has a region in contact with the side surface of the EL layer 113 and functions as a protective insulating layer for the EL layer 113. By providing the insulating layer 125, impurities (oxygen, moisture, and the like) can be prevented from entering the inside from the side surface of the EL layer 113, and a highly reliable display device can be provided.

[0138] The insulating layer 125 can be an insulating layer containing an inorganic material. For example, an inorganic insulating film such as an insulating oxide film, a nitride insulating film, an oxynitride insulating film, or a nitride oxide insulating film can be used for the insulating layer 125. The insulating layer 125 may have a single-layer structure or a stacked-layer structure. Examples of oxide insulating films include a silicon oxide film, an aluminum oxide film, a magnesium oxide film, an indium gallium zinc oxide film, a gallium oxide film, a germanium oxide film, an yttrium oxide film, a zirconium oxide film, a lanthanum oxide film, a neodymium oxide film, a hafnium oxide film, and a tantalum oxide film. Examples of nitride insulating films include a silicon nitride film and an aluminum nitride film. Examples of oxynitride insulating films include a silicon oxynitride film and an aluminum oxynitride film. Examples of nitride oxide insulating films include a silicon nitride oxide film and an aluminum nitride oxide film. In particular, aluminum oxide is preferable because it has a high etching selectivity with respect to the EL layer and has a function of protecting the EL layer in the formation of the insulating layer 127 described later. In particular, by using an inorganic insulating film such as an aluminum oxide film, a hafnium oxide film, or a silicon oxide film formed by an ALD method as the insulating layer 125, it is possible to form an insulating layer 125 with few pinholes and excellent protection of the EL layer. The insulating layer 125 may also have a stacked structure of a film formed by an ALD method and a film formed by a sputtering method. For example, the insulating layer 125 may have a stacked structure of an aluminum oxide film formed by an ALD method and a silicon nitride film formed by a sputtering method.

[0139] In this specification and the like, an oxynitride refers to a material whose composition contains more oxygen than nitrogen, and a nitride oxide refers to a material whose composition contains more nitrogen than oxygen. For example, silicon oxynitride refers to a material whose composition contains more oxygen than nitrogen, and silicon nitride oxide refers to a material whose composition contains more nitrogen than oxygen.

[0140] The insulating layer 125 preferably functions as a barrier insulating layer against at least one of water and oxygen. The insulating layer 125 preferably has a function of suppressing diffusion of at least one of water and oxygen. The insulating layer 125 preferably has a function of capturing or fixing (also referred to as gettering) at least one of water and oxygen.

[0141] The insulating layer 125 has a function as a barrier insulating layer or a gettering function, which makes it possible to suppress the intrusion of impurities (typically, at least one of water and oxygen) that may diffuse into each light-emitting device from the outside. With this configuration, it is possible to provide a highly reliable light-emitting device and further a highly reliable display device.

[0142] The insulating layer 125 preferably has a low impurity concentration. This can prevent impurities from entering the EL layer from the insulating layer 125 and causing deterioration of the EL layer. Furthermore, a low impurity concentration in the insulating layer 125 can improve the barrier properties against at least one of water and oxygen. For example, it is desirable that the insulating layer 125 has a sufficiently low hydrogen concentration or a sufficiently low carbon concentration, or preferably both of them.

[0143] Examples of a method for forming the insulating layer 125 include a sputtering method, a CVD method, a pulsed laser deposition (PLD) method, and an ALD method. The insulating layer 125 is preferably formed by an ALD method, which has good coverage.

[0144] By increasing the substrate temperature during deposition of the insulating layer 125, the insulating layer 125 can be formed with a low impurity concentration and a high barrier property against at least one of water and oxygen, even if the insulating layer 125 is thin. Therefore, the substrate temperature is preferably 60° C. or higher, more preferably 80° C. or higher, more preferably 100° C. or higher, and still more preferably 120° C. or higher. On the other hand, since the insulating layer 125 is deposited after the island-shaped EL layer is formed, it is preferably formed at a temperature lower than the heat-resistant temperature of the EL layer. Therefore, the substrate temperature is preferably 200° C. or lower, more preferably 180° C. or lower, more preferably 160° C. or lower, more preferably 150° C. or lower, and still more preferably 140° C. or lower.

[0145] Examples of the heat resistance temperature index include a glass transition point, a softening point, a melting point, a thermal decomposition temperature, and a 5% weight loss temperature, etc. The heat resistance temperature of the EL layer can be any of these temperatures, preferably the lowest temperature among these.

[0146] The insulating layer 127 provided on the insulating layer 125 has the function of planarizing recesses in the insulating layer 125 formed between adjacent light-emitting devices. In other words, the insulating layer 127 improves the flatness of the surface on which the common electrode 115 is formed. An insulating layer containing an organic material can be suitably used as the insulating layer 127. For example, acrylic resin, polyimide resin, epoxy resin, imide resin, polyamide resin, polyimideamide resin, silicone resin, siloxane resin, benzocyclobutene-based resin, phenolic resin, and precursors of these resins can be used as the insulating layer 127. Alternatively, organic materials such as polyvinyl alcohol (PVA), polyvinyl butyral, polyvinylpyrrolidone, polyethylene glycol, polyglycerin, pullulan, water-soluble cellulose, or alcohol-soluble polyamide resin can be used as the insulating layer 127. Alternatively, a photosensitive resin can be used as the insulating layer 127. Photoresist can be used as the photosensitive resin. The photosensitive resin can be a positive-type material or a negative-type material.

[0147] The insulating layer 127 may be made of a material that absorbs visible light. The insulating layer 127 absorbs light emitted from the light-emitting device, thereby preventing light from leaking from the light-emitting device to an adjacent light-emitting device through the insulating layer 127 (stray light). This improves the display quality of the display device. Furthermore, since the display quality can be improved without using a polarizing plate in the display device, the display device can be made lighter and thinner.

[0148] Examples of materials that absorb visible light include materials containing pigments such as black, materials containing dyes, light-absorbing resin materials (e.g., polyimide), and resin materials that can be used for color filters (color filter materials). In particular, using a resin material that is a mixture of two or more color filter materials is preferable because it can enhance the visible light blocking effect. In particular, mixing three or more color filter materials makes it possible to form a resin layer that is black or nearly black.

[0149] 6A to 6F show the cross-sectional structure of a region 139 including the insulating layer 127 and its surroundings.

[0150] FIG. 6A shows an example in which the thickness of the pixel electrodes differs depending on the subpixel of each color. FIG. 6A shows an example in which the pixel electrode 111a has a two-layer structure and the pixel electrode 111b has a single-layer structure. Specifically, the pixel electrodes 111a and 111b have different thicknesses. Because the EL layer 113 is formed in common for the subpixels of each color, the thickness of the EL layer 113 on the pixel electrode 111a is the same as or approximately the same as the thickness of the EL layer 113 on the pixel electrode 111b. Therefore, the height of the top surface of the EL layer 113 on the pixel electrode 111a is different from that on the pixel electrode 111b. The height of the top surface of the insulating layer 125 is the same as or approximately the same as the height of the top surface of the EL layer 113 on both the pixel electrode 111a side and the pixel electrode 111b side. The top surface of the insulating layer 127 has a gentle slope, with the pixel electrode 111a side being higher and the pixel electrode 111b side being lower. In this way, the heights of the insulating layers 125 and 127 are preferably aligned with the height of the top surfaces of the adjacent EL layers. Alternatively, the insulating layers 125 and 127 may have flat portions that are aligned with the height of the top surface of one of the adjacent EL layers.

[0151] 6B , the upper surface of insulating layer 127 has a region that is higher than the upper surface of EL layer 113. As shown in Fig. 6B , the upper surface of insulating layer 127 can be configured to have a shape in which the center and its vicinity bulge in cross section, that is, a shape having a convex curved surface.

[0152] 6C , the upper surface of insulating layer 127 has a shape that gradually bulges toward the center, i.e., a convex curved surface, and a shape that is recessed in the center and its vicinity, i.e., a concave curved surface, in a cross-sectional view. Insulating layer 127 has a region that is higher than the upper surface of EL layer 113. In addition, in region 139, the display device has at least one of sacrificial layer 118 and sacrificial layer 119. The ends of insulating layer 125 and insulating layer 127 each overlap the upper surface of EL layer 113 and are located on at least one of sacrificial layer 118 and sacrificial layer 119.

[0153] 6D, the upper surface of insulating layer 127 has an area that is lower than the upper surface of EL layer 113. In addition, the upper surface of insulating layer 127 has a recessed shape in the center and its vicinity in cross-sectional view, that is, a shape having a concave curved surface.

[0154] 6E, the upper surface of the insulating layer 125 has a region higher than the upper surface of the EL layer 113. That is, the insulating layer 125 protrudes from the surface on which the common layer 114 is to be formed, forming a convex portion.

[0155] When forming the insulating layer 125, for example, if the insulating layer 125 is formed so that its height is aligned or approximately aligned with that of the sacrificial layer, the insulating layer 125 may be formed in a protruding shape as shown in FIG. 6E.

[0156] 6F, the upper surface of the insulating layer 125 has an area that is lower than the upper surface of the EL layer 113. That is, the insulating layer 125 forms a recess on the surface where the common layer 114 is to be formed.

[0157] In this way, the insulating layer 125 and the insulating layer 127 can be applied in various shapes.

[0158] As the sacrificial layer, for example, one or more types of inorganic films such as metal films, alloy films, metal oxide films, semiconductor films, and inorganic insulating films can be used.

[0159] The sacrificial layer can be made of metal materials such as gold, silver, platinum, magnesium, nickel, tungsten, chromium, molybdenum, iron, cobalt, copper, palladium, titanium, aluminum, yttrium, zirconium, and tantalum, as well as alloy materials containing these metal materials.

[0160] The sacrificial layer can be made of a metal oxide such as In—Ga—Zn oxide. For example, an In—Ga—Zn oxide film can be formed as the sacrificial layer by sputtering. Other examples include indium oxide, In—Zn oxide, In—Sn oxide, indium titanium oxide (In—Ti oxide), indium tin zinc oxide (In—Sn—Zn oxide), indium titanium zinc oxide (In—Ti—Zn oxide), and indium gallium tin zinc oxide (In—Ga—Sn—Zn oxide). Alternatively, silicon-containing indium tin oxide can be used.

[0161] In addition, instead of the above gallium, an element M (M is one or more elements selected from aluminum, silicon, boron, yttrium, copper, vanadium, beryllium, titanium, iron, nickel, germanium, zirconium, molybdenum, lanthanum, cerium, neodymium, hafnium, tantalum, tungsten, and magnesium) may be used.

[0162] The sacrificial layer can be formed using any of various inorganic insulating films that can be used for the protective layer 131. In particular, an oxide insulating film is preferable because it has higher adhesion to the EL layer than a nitride insulating film. For example, the sacrificial layer can be formed using inorganic insulating materials such as aluminum oxide, hafnium oxide, and silicon oxide. For example, an aluminum oxide film can be formed using an ALD method. The ALD method is preferable because it can reduce damage to the base (especially the EL layer). For example, a silicon nitride film can be formed using a sputtering method.

[0163] For example, the sacrificial layer may be a stacked structure of an inorganic insulating film (e.g., an aluminum oxide film) formed by ALD and an In—Ga—Zn oxide film formed by sputtering, or a stacked structure of an inorganic insulating film (e.g., an aluminum oxide film) formed by ALD and an aluminum film, a tungsten film, or an inorganic insulating film (e.g., a silicon nitride film) formed by sputtering.

[0164] The display device of this embodiment can reduce the distance between light-emitting devices. Specifically, the distance between light-emitting devices, the distance between EL layers, or the distance between pixel electrodes can be less than 10 μm, 5 μm or less, 3 μm or less, 2 μm or less, 1 μm or less, 500 nm or less, 200 nm or less, 100 nm or less, 90 nm or less, 70 nm or less, 50 nm or less, 30 nm or less, 20 nm or less, 15 nm or less, or 10 nm or less. In other words, the display device of this embodiment has a region where the distance between two adjacent EL layers 113 is 1 μm or less, preferably a region where the distance is 0.5 μm (500 nm) or less, and more preferably a region where the distance is 100 nm or less.

[0165] A light-shielding layer may be provided on the surface of the substrate 120 facing the resin layer 122. Various optical components may be disposed on the exterior of the substrate 120. Examples of optical components include a polarizing plate, a retardation plate, a light-diffusing layer (such as a diffusion film), an anti-reflection layer, and a light-collecting film. Surface protective layers, such as an antistatic film to prevent dust adhesion, a water-repellent film to prevent dirt adhesion, a hard coat film to prevent scratches during use, and an impact-absorbing layer, may also be disposed on the exterior of the substrate 120. For example, a glass layer or a silica layer (SiOx layer) may be provided as the surface protective layer to prevent surface contamination and scratches, which is preferable. Materials such as DLC (diamond-like carbon), alumina (AlOx), polyester-based materials, and polycarbonate-based materials may also be used for the surface protective layer. It is preferable to use a material with high transmittance to visible light for the surface protective layer. It is also preferable to use a material with high hardness for the surface protective layer.

[0166] The substrate 120 can be made of glass, quartz, ceramic, sapphire, resin, metal, alloy, semiconductor, or the like. A material that transmits light is used for the substrate on the side from which light from the light-emitting device is extracted. Using a flexible material for the substrate 120 can increase the flexibility of the display device and realize a flexible display. A polarizing plate may also be used as the substrate 120.

[0167] The substrate 120 can be made of polyester resin such as polyethylene terephthalate (PET) or polyethylene naphthalate (PEN), polyacrylonitrile resin, acrylic resin, polyimide resin, polymethyl methacrylate resin, polycarbonate (PC) resin, polyethersulfone (PES) resin, polyamide resin (nylon, aramid, etc.), polysiloxane resin, cycloolefin resin, polystyrene resin, polyamideimide resin, polyurethane resin, polyvinyl chloride resin, polyvinylidene chloride resin, polypropylene resin, polytetrafluoroethylene (PTFE) resin, ABS resin, cellulose nanofiber, etc. The substrate 120 can also be made of glass having a thickness sufficient to provide flexibility.

[0168] When a circularly polarizing plate is superimposed on a display device, it is preferable that the display device has a substrate with high optical isotropy. A substrate with high optical isotropy has small birefringence (or a small amount of birefringence).

[0169] The absolute value of the retardation (phase difference) of a substrate having high optical isotropy is preferably 30 nm or less, more preferably 20 nm or less, and even more preferably 10 nm or less.

[0170] Examples of films with high optical isotropy include triacetyl cellulose (TAC, also known as cellulose triacetate) films, cycloolefin polymer (COP) films, cycloolefin copolymer (COC) films, and acrylic films.

[0171] Furthermore, when a film is used as a substrate, the film may absorb water, causing deformation such as wrinkles in the display panel. Therefore, it is preferable to use a film with low water absorption for the substrate. For example, it is preferable to use a film with a water absorption rate of 1% or less, more preferably 0.1% or less, and even more preferably 0.01% or less.

[0172] The resin layer 122 can be made of various curable adhesives, such as a photo-curable adhesive (e.g., an ultraviolet curable adhesive), a reactive curable adhesive, a thermosetting adhesive, or an anaerobic adhesive. Examples of such adhesives include epoxy resin, acrylic resin, silicone resin, phenolic resin, polyimide resin, imide resin, PVC (polyvinyl chloride) resin, PVB (polyvinyl butyral) resin, and EVA (ethylene vinyl acetate) resin. Materials with low moisture permeability, such as epoxy resin, are particularly preferred. Two-component resins may also be used. Adhesive sheets or the like may also be used.

[0173] Next, materials that can be used in light-emitting devices will be described.

[0174] Of the pixel electrode and the common electrode, the electrode from which light is extracted is preferably made of a conductive film that transmits visible light. Furthermore, it is preferable that the electrode from which light is not extracted is made of a conductive film that reflects visible light. Furthermore, when the display device has a light-emitting device that emits infrared light, it is preferable that the electrode from which light is extracted is made of a conductive film that transmits visible light and infrared light, and the electrode from which light is not extracted is made of a conductive film that reflects visible light and infrared light.

[0175] Furthermore, a conductive film that transmits visible light may also be used for the electrode on the side from which light is not extracted. In this case, it is preferable to place the electrode between the reflective layer and the EL layer. That is, light emitted from the EL layer may be reflected by the reflective layer and extracted from the display device. Various light-reflecting materials may be used for the reflective layer. One or more of an insulator, a semiconductor, and a conductor may be used for the reflective layer. The reflectance of the reflective layer for visible light is preferably 40% or more and 100% or less, and more preferably 70% or more and 100% or less.

[0176] The pair of electrodes (pixel electrode and common electrode) of the light-emitting device can be formed from a material such as a metal, an alloy, an electrically conductive compound, or a mixture thereof. Specific examples include indium tin oxide (In-Sn oxide, also referred to as ITO), In-Si-Sn oxide (also referred to as ITSO), indium zinc oxide (In-Zn oxide), In-W-Zn oxide, an aluminum-containing alloy (aluminum alloy) such as an alloy of aluminum, nickel, and lanthanum (Al-Ni-La), and an alloy of silver and magnesium, and an alloy of silver, palladium, and copper (Ag-Pd-Cu, also referred to as APC). Other examples of the metals that can be used include aluminum (Al), magnesium (Mg), titanium (Ti), chromium (Cr), manganese (Mn), iron (Fe), cobalt (Co), nickel (Ni), copper (Cu), gallium (Ga), zinc (Zn), indium (In), tin (Sn), molybdenum (Mo), tantalum (Ta), tungsten (W), palladium (Pd), gold (Au), platinum (Pt), silver (Ag), yttrium (Y), and neodymium (Nd), as well as alloys containing appropriate combinations of these metals. Other examples of the metals that can be used include elements belonging to Group 1 or Group 2 of the periodic table (e.g., lithium (Li), cesium (Cs), calcium (Ca), and strontium (Sr)), rare earth metals such as europium (Eu), and ytterbium (Yb), as well as alloys containing appropriate combinations of these metals, graphene, and the like.

[0177] The light-emitting device preferably has a micro-optical resonator (microcavity) structure. Therefore, one of a pair of electrodes of the light-emitting device preferably has a transmissive and reflective electrode for visible light, and the other preferably has a reflective electrode for visible light. By having the light-emitting device have a microcavity structure, the light emitted from the light-emitting layer can be resonated between the two electrodes, thereby intensifying the light emitted from the light-emitting device.

[0178] The semi-transmitting / semi-reflective electrode can have a laminated structure of a reflective electrode and an electrode that is transparent to visible light (also called a transparent electrode).

[0179] The light transmittance of the transparent electrode is 40% or more. For example, it is preferable to use an electrode with a visible light (light with a wavelength of 400 nm or more and less than 750 nm) transmittance of 40% or more for a light-emitting device. The visible light reflectance of the semi-transparent / semi-reflective electrode is 10% or more and 95% or less, preferably 30% or more and 80% or less. The visible light reflectance of the reflective electrode is 40% or more and 100% or less, preferably 70% or more and 100% or less. The resistivity of these electrodes is 1×10 −２ Preferably, it is Ωcm or less.

[0180] The light-emitting layer is a layer containing a light-emitting material (also referred to as a light-emitting substance). The light-emitting layer can contain one or more light-emitting substances. As the light-emitting substance, a substance that emits light of a color such as blue, purple, blue-purple, green, yellow-green, yellow, orange, or red is appropriately used. Furthermore, a substance that emits near-infrared light can also be used as the light-emitting substance.

[0181] Examples of the light-emitting material include fluorescent materials, phosphorescent materials, TADF materials, and quantum dot materials.

[0182] Examples of fluorescent materials include pyrene derivatives, anthracene derivatives, triphenylene derivatives, fluorene derivatives, carbazole derivatives, dibenzothiophene derivatives, dibenzofuran derivatives, dibenzoquinoxaline derivatives, quinoxaline derivatives, pyridine derivatives, pyrimidine derivatives, phenanthrene derivatives, and naphthalene derivatives.

[0183] Examples of phosphorescent materials include organometallic complexes (particularly iridium complexes) having a 4H-triazole skeleton, a 1H-triazole skeleton, an imidazole skeleton, a pyrimidine skeleton, a pyrazine skeleton, or a pyridine skeleton; organometallic complexes (particularly iridium complexes) having a phenylpyridine derivative having an electron-withdrawing group as a ligand; platinum complexes; and rare earth metal complexes.

[0184] The light-emitting layer may contain one or more organic compounds (host materials, assist materials, etc.) in addition to a light-emitting substance (guest material). As the one or more organic compounds, one or both of a hole-transporting material and an electron-transporting material can be used. Furthermore, as the one or more organic compounds, a bipolar material or a TADF material can be used.

[0185] The light-emitting layer preferably includes, for example, a phosphorescent material and a hole-transporting material and an electron-transporting material that are a combination that easily forms an exciplex. This configuration allows for efficient emission using Exciplex-Triple Energy Transfer (ExTET), which is energy transfer from the exciplex to the light-emitting material (phosphorescent material). By selecting a combination that forms an exciplex that emits light that overlaps with the wavelength of the lowest-energy absorption band of the light-emitting material, energy transfer becomes smooth, allowing for efficient emission. This configuration simultaneously enables high efficiency, low-voltage operation, and long life of the light-emitting device.

[0186] The EL layer 113 (or the light-emitting unit) may further include, as a layer other than the light-emitting layer, a layer containing a substance with a high hole-injection property, a substance with a high hole-transport property (also referred to as a hole-transport material), a hole-blocking material, a substance with a high electron-transport property (also referred to as an electron-transport material), a substance with a high electron-injection property, an electron-blocking material, or a bipolar substance (a substance with high electron-transport property and high hole-transport property, also referred to as a bipolar material).

[0187] The light-emitting device can be made of either a low-molecular-weight compound or a high-molecular-weight compound, and may contain an inorganic compound. The layers constituting the light-emitting device can be formed by a method such as vapor deposition (including vacuum vapor deposition), transfer, printing, inkjet printing, or coating.

[0188] For example, the EL layer 113 (or light-emitting unit) may include one or more of a hole-injection layer, a hole-transport layer, a hole-blocking layer, an electron-blocking layer, an electron-transport layer, and an electron-injection layer.

[0189] The common layer 114 may be one or more of a hole injection layer, a hole transport layer, a hole blocking layer, an electron blocking layer, an electron transport layer, and an electron injection layer. For example, a carrier injection layer (hole injection layer or electron injection layer) may be formed as the common layer 114. Note that the light-emitting device 130 does not necessarily have to have the common layer 114.

[0190] The top light-emitting unit in the EL layer 113 (the second light-emitting unit 113c in this embodiment) preferably includes a light-emitting layer and a carrier transport layer on the light-emitting layer. This prevents the light-emitting layer from being exposed to the outermost surface during the manufacturing process of the display device 100, thereby reducing damage to the light-emitting layer. This improves the reliability of the light-emitting device.

[0191] The hole injection layer is a layer that injects holes from the anode into the hole transport layer and contains a substance with high hole injection properties, such as an aromatic amine compound and a composite material containing a hole transport material and an acceptor material (electron acceptor material).

[0192] The hole transport layer is a layer that transports holes injected from the anode by the hole injection layer to the light emitting layer. The hole transport layer is a layer that contains a hole transporting material. The hole transporting material is a material having a concentration of 1×10 −６ cm ２ A substance having a hole mobility of 1 / Vs or more is preferred. Note that other substances can also be used as long as they have a higher hole transporting property than electron transporting property. As the hole transporting material, a substance having a high hole transporting property, such as a π-electron-rich heteroaromatic compound (e.g., a carbazole derivative, a thiophene derivative, a furan derivative, etc.) or an aromatic amine (a compound having an aromatic amine skeleton), is preferred.

[0193] The electron transport layer is a layer that transports electrons injected from the cathode by the electron injection layer to the light emitting layer. The electron transport layer is a layer that contains an electron transporting material. The electron transporting material is a material having a concentration of 1×10 −６ cm ２ / Vs or more is preferred. Note that other substances can also be used as long as they have a higher electron transporting property than holes. Examples of electron-transporting materials that can be used include metal complexes having a quinoline skeleton, metal complexes having a benzoquinoline skeleton, metal complexes having an oxazole skeleton, and metal complexes having a thiazole skeleton, as well as oxadiazole derivatives, triazole derivatives, imidazole derivatives, oxazole derivatives, thiazole derivatives, phenanthroline derivatives, quinoline derivatives having a quinoline ligand, benzoquinoline derivatives, quinoxaline derivatives, dibenzoquinoxaline derivatives, pyridine derivatives, bipyridine derivatives, pyrimidine derivatives, and other π-electron-deficient heteroaromatic compounds including nitrogen-containing heteroaromatic compounds.

[0194] The electron injection layer is a layer that injects electrons from the cathode to the electron transport layer and contains a substance with high electron injection properties. Examples of the substance with high electron injection properties include alkali metals, alkaline earth metals, and compounds thereof. Examples of the substance with high electron injection properties include a composite material containing an electron transport material and a donor material (electron donor material).

[0195] The electron injection layer may be formed of, for example, lithium, cesium, ytterbium, lithium fluoride (LiF), cesium fluoride (CsF), calcium fluoride (CaF ｘ , where X is an arbitrary number), 8-(quinolinolato)lithium (abbreviation: Liq), 2-(2-pyridyl)phenolatolithium (abbreviation: LiPP), 2-(2-pyridyl)-3-pyridinolatolithium (abbreviation: LiPPy), 4-phenyl-2-(2-pyridyl)phenolatolithium (abbreviation: LiPPP), lithium oxide (LiO ｘ ), alkali metals such as cesium carbonate, alkaline earth metals, or compounds thereof can be used. The electron injection layer may have a stacked structure of two or more layers. For example, the stacked structure may have a structure in which lithium fluoride is used in the first layer and ytterbium is provided in the second layer.

[0196] Alternatively, an electron transporting material may be used for the electron injection layer. For example, a compound having an unshared electron pair and an electron-deficient heteroaromatic ring may be used as the electron transporting material. Specifically, a compound having at least one of a pyridine ring, a diazine ring (pyrimidine ring, pyrazine ring, pyridazine ring), and a triazine ring may be used.

[0197] The organic compound having an unshared electron pair preferably has a lowest unoccupied molecular orbital (LUMO) of -3.6 eV to -2.3 eV. Generally, the highest occupied molecular orbital (HOMO) level and the LUMO level of an organic compound can be estimated by cyclic voltammetry (CV), photoelectron spectroscopy, optical absorption spectroscopy, inverse photoelectron spectroscopy, or the like.

[0198] For example, 4,7-diphenyl-1,10-phenanthroline (abbreviation: BPhen), 2,9-di(naphthalen-2-yl)-4,7-diphenyl-1,10-phenanthroline (abbreviation: NBPhen), diquinoxalino[2,3-a:2',3'-c]phenazine (abbreviation: HATNA), 2,4,6-tris[3'-(pyridin-3-yl)biphenyl-3-yl]-1,3,5-triazine (abbreviation: TmPPPyTz), etc. can be used as the organic compound having an unshared electron pair. Note that NBPhen has a higher glass transition point (Tg) and is superior in heat resistance compared to BPhen.

[0199] In addition, in this embodiment, a tandem structure is applied to the light-emitting device 130. To this end, a charge generation layer is provided between the two light-emitting units. The charge generation layer has at least a charge generation region. The charge generation layer has the function of injecting electrons into one of the two light-emitting units and injecting holes into the other when a voltage is applied between a pair of electrodes.

[0200] As described above, the charge generation layer has at least a charge generation region. The charge generation region preferably contains an acceptor material (electron-accepting material), and preferably contains, for example, a hole-transporting material and an acceptor material applicable to the hole injection layer.

[0201] The charge generation layer preferably includes a layer containing a substance with high electron injection properties. This layer may also be called an electron injection buffer layer. The electron injection buffer layer is preferably provided between the charge generation region and the electron transport layer. By providing the electron injection buffer layer, the injection barrier between the charge generation region and the electron transport layer can be alleviated, so that electrons generated in the charge generation region can be easily injected into the electron transport layer.

[0202] The electron injection buffer layer preferably contains an alkali metal or an alkaline earth metal, and may contain, for example, an alkali metal compound or an alkaline earth metal compound. Specifically, the electron injection buffer layer preferably contains an inorganic compound containing an alkali metal and oxygen, or an inorganic compound containing an alkaline earth metal and oxygen, and may contain an inorganic compound containing lithium and oxygen (lithium oxide (Li ２ In addition, the electron injection buffer layer can be suitably made of the materials applicable to the electron injection layer described above.

[0203] The charge generation layer preferably has a layer containing a substance with high electron transport properties. This layer can also be called an electron relay layer. The electron relay layer is preferably provided between the charge generation region and the electron injection buffer layer. When the charge generation layer does not have an electron injection buffer layer, the electron relay layer is preferably provided between the charge generation region and the electron transport layer. The electron relay layer has the function of preventing interaction between the charge generation region and the electron injection buffer layer (or the electron transport layer) and smoothly transferring electrons.

[0204] For the electron relay layer, it is preferable to use a phthalocyanine-based material such as copper (II) phthalocyanine (abbreviated as CuPc) or a metal complex having a metal-oxygen bond and an aromatic ligand.

[0205] It should be noted that the charge generation region, electron injection buffer layer, and electron relay layer may not be clearly distinguishable from one another depending on their cross-sectional shapes or characteristics.

[0206] The charge generation layer may contain a donor material instead of an acceptor material. For example, the charge generation layer may contain a layer containing an electron transport material and a donor material that can be used for the electron injection layer.

[0207] When light-emitting units are stacked, an increase in driving voltage can be suppressed by providing a charge generating layer between two light-emitting units.

[0208] [Example of a manufacturing method of a display device] Next, an example of a manufacturing method of a display device will be described with reference to Fig. 7 and Fig. 8. Fig. 7A to Fig. 7D and Fig. 8A to Fig. 8C show a cross-sectional view taken along dashed dotted line A1-A2 in Fig. 1A and a cross-sectional view taken along dashed dotted line C1-C2 in Fig. 1A side by side.

[0209] Thin films (insulating films, semiconductor films, conductive films, etc.) constituting display devices can be formed using a sputtering method, a chemical vapor deposition (CVD) method, a vacuum evaporation method, a pulsed laser deposition (PLD) method, an ALD method, etc. CVD methods include a plasma enhanced chemical vapor deposition (PECVD) method and a thermal CVD method. One type of thermal CVD method is a metal organic chemical vapor deposition (MOCVD) method.

[0210] Furthermore, thin films (insulating films, semiconductor films, conductive films, etc.) constituting the display device can be formed by methods such as spin coating, dipping, spray coating, inkjet, dispensing, screen printing, offset printing, doctor knife, slit coating, roll coating, curtain coating, and knife coating.

[0211] In particular, vacuum processes such as vapor deposition and solution processes such as spin coating and inkjet printing can be used to fabricate light-emitting devices. Vapor deposition methods include physical vapor deposition (PVD) methods such as sputtering, ion plating, ion beam deposition, molecular beam deposition, and vacuum deposition, and chemical vapor deposition (CVD). In particular, functional layers included in the EL layer (hole injection layer, hole transport layer, light-emitting layer, electron transport layer, electron injection layer, etc.) can be formed by vapor deposition (vacuum deposition, etc.), coating methods (dip coating, die coating, bar coating, spin coating, spray coating, etc.), printing methods (inkjet printing, screen (stencil printing), offset (lithographic printing), flexography (relief printing), gravure, microcontact printing, etc.), etc.

[0212] Furthermore, when processing the thin film that constitutes the display device, a photolithography method or the like can be used. Alternatively, the thin film may be processed by a nanoimprint method, a sandblasting method, a lift-off method, or the like. Furthermore, the island-shaped thin film may be directly formed by a film formation method using a shielding mask such as a metal mask.

[0213] There are two typical photolithography methods: one is to form a resist mask on the thin film to be processed, process the thin film by etching or the like, and then remove the resist mask; the other is to form a photosensitive thin film, and then process the thin film into the desired shape by exposure and development.

[0214] In photolithography, the light used for exposure may be, for example, i-line (wavelength 365 nm), g-line (wavelength 436 nm), h-line (wavelength 405 nm), or a mixture of these. Other light sources that can be used include ultraviolet light, KrF laser light, ArF laser light, etc. Exposure may also be performed by immersion exposure technology. Extreme ultraviolet (EUV) light or X-rays may also be used as the light used for exposure. An electron beam may also be used instead of the light used for exposure. Extreme ultraviolet light, X-rays, or an electron beam are preferred because they enable extremely fine processing. When exposure is performed by scanning a beam such as an electron beam, a photomask is not required.

[0215] For etching the thin film, dry etching, wet etching, sandblasting, or the like can be used.

[0216] First, the pixel electrode 111 and the conductive layer 123 are formed over the transistor-including layer 101 (FIG. 7A). The pixel electrode 111 can be formed by, for example, sputtering or vacuum evaporation.

[0217] Subsequently, an EL layer 113A, which will later become the EL layer 113, is formed on the pixel electrode 111 and the layer 101 including the transistor (FIG. 7B).

[0218] 7B , in the cross-sectional view between the dashed dotted line C1-C2, the EL layer 113A is not formed on the conductive layer 123. For example, by using a mask 191 (also called an area mask or a rough metal mask to distinguish it from a fine metal mask) for defining a deposition area, the EL layer 113A can be deposited only in a desired region. In one embodiment of the present invention, a light-emitting device is formed using a resist mask. However, by combining the resist mask with an area mask as described above, a light-emitting device can be manufactured by a relatively simple process.

[0219] The EL layer 113A can be formed by, for example, a vapor deposition method, specifically a vacuum deposition method. Fig. 7B shows a state in which the EL layer 113A is formed by a so-called face-down method, in which the substrate is inverted so that the surface to be formed faces downward.

[0220] The EL layer 113A may be formed by a transfer method, a printing method, an inkjet method, a coating method, or the like.

[0221] Next, a sacrificial layer 118A, which will later become the sacrificial layer 118, and a sacrificial layer 119A, which will later become the sacrificial layer 119, are formed in this order on the EL layer 113A and the conductive layer 123 (FIG. 7C). For the sacrificial layer 118A and the sacrificial layer 119A, a film that is highly resistant to the processing conditions of the EL layer 113A, specifically a film that has a large etching selectivity with respect to the EL layer 113A, is used.

[0222] The sacrificial layers 118A and 119A can be formed by, for example, sputtering, ALD (including thermal ALD and PEALD), CVD, or vacuum evaporation. The sacrificial layer 118A formed on and in contact with the EL layer 113A is preferably formed using a method that causes less damage to the EL layer 113A than the sacrificial layer 119A. For example, the sacrificial layer 118A is preferably formed using ALD or vacuum evaporation rather than sputtering. The sacrificial layers 118A and 119A are formed at a temperature lower than the heat-resistant temperature of the EL layer 113A. The substrate temperatures used to form the sacrificial layers 118A and 119A are typically 200° C. or lower, preferably 150° C. or lower, more preferably 120° C. or lower, more preferably 100° C. or lower, and even more preferably 80° C. or lower.

[0223] It is preferable to use a film that can be removed by wet etching for the sacrificial layers 118A and 119A. By using wet etching, damage to the EL layer 113A during processing of the sacrificial layers 118A and 119A can be reduced compared to when dry etching is used.

[0224] It is also preferable to use a film for the sacrificial layer 118A that has a large etching selectivity with respect to the sacrificial layer 119A.

[0225] In the process of processing the various sacrificial layers in the manufacturing method of the display device of this embodiment, it is desirable that the layers constituting the EL layer (such as the hole injection layer, the hole transport layer, the light-emitting layer, and the electron transport layer) are not easily processed, and that the various sacrificial layers are not easily processed in the process of processing the layers constituting the EL layer. It is desirable to select the material and processing method of the sacrificial layer and the processing method of the EL layer taking these factors into consideration.

[0226] Although this embodiment shows an example in which the sacrificial layer is formed with a two-layer structure of the sacrificial layer 118A and the sacrificial layer 119A, the sacrificial layer may have a single layer structure or a laminated structure of three or more layers.

[0227] The sacrificial layer 118A and the sacrificial layer 119A may each be, for example, a metal film, an alloy film, a metal oxide film, a semiconductor film, or an inorganic film such as an organic insulating film or an inorganic insulating film.

[0228] The sacrificial layers 118A and 119A can each be made of a metal material such as gold, silver, platinum, magnesium, nickel, tungsten, chromium, molybdenum, iron, cobalt, copper, palladium, titanium, aluminum, yttrium, zirconium, or tantalum, or an alloy material containing such a metal material. It is particularly preferable to use a low-melting-point material such as aluminum or silver. Using a metal material capable of blocking ultraviolet light for one or both of the sacrificial layers 118A and 119A is preferable because it can prevent ultraviolet light from being irradiated onto the EL layer and thereby prevent deterioration of the EL layer.

[0229] Furthermore, metal oxides such as In—Ga—Zn oxide can be used for the sacrificial layers 118A and 119A. For example, an In—Ga—Zn oxide film can be formed as the sacrificial layer 118A or 119A by sputtering. Furthermore, indium oxide, In—Zn oxide, In—Sn oxide, indium titanium oxide (In—Ti oxide), indium tin zinc oxide (In—Sn—Zn oxide), indium titanium zinc oxide (In—Ti—Zn oxide), indium gallium tin zinc oxide (In—Ga—Sn—Zn oxide), etc. can also be used. Alternatively, indium tin oxide containing silicon can also be used.

[0230] In addition, instead of the above gallium, an element M (M is one or more elements selected from aluminum, silicon, boron, yttrium, copper, vanadium, beryllium, titanium, iron, nickel, germanium, zirconium, molybdenum, lanthanum, cerium, neodymium, hafnium, tantalum, tungsten, and magnesium) may be used.

[0231] The sacrificial layers 118A and 119A can each be made of any of the various inorganic insulating films that can be used for the protective layer 131. In particular, oxide insulating films are preferable because they have higher adhesion to the EL layer than nitride insulating films. For example, inorganic insulating materials such as aluminum oxide, hafnium oxide, and silicon oxide can be used for the sacrificial layers 118A and 119A. For example, an aluminum oxide film can be formed as the sacrificial layer 118A or 119A by using the ALD method. Using the ALD method is preferable because it can reduce damage to the underlying layer (particularly the EL layer, etc.).

[0232] For example, the sacrificial layer 118A can be an inorganic insulating film (e.g., an aluminum oxide film) formed using the ALD method, and the sacrificial layer 119A can be an inorganic film (e.g., an In—Ga—Zn oxide film, an aluminum film, or a tungsten film) formed using the sputtering method.

[0233] The same inorganic insulating film can be used for both the sacrificial layer 118A and the insulating layer 125 to be formed later. For example, an aluminum oxide film formed using an ALD method can be used for both the sacrificial layer 118A and the insulating layer 125. The same deposition conditions can be applied to the sacrificial layer 118A and the insulating layer 125, or different deposition conditions can be applied to each of them. For example, by depositing the sacrificial layer 118A under the same conditions as the insulating layer 125, the sacrificial layer 118A can be an insulating layer with high barrier properties against at least one of water and oxygen. On the other hand, since the sacrificial layer 118A is a layer that is removed mostly or entirely in a later process, it is preferable that it be easily processed. Therefore, the sacrificial layer 118A is preferably deposited under conditions where the substrate temperature during deposition is lower than that of the insulating layer 125.

[0234] An organic material may be used for one or both of the sacrificial layers 118A and 119A. For example, the organic material may be a material that is soluble in a solvent that is chemically stable with respect to at least the film located at the top of the EL layer 113A. In particular, a material that dissolves in water or alcohol is preferably used. When forming a film of such a material, it is preferable to apply the material dissolved in a solvent such as water or alcohol by a wet film formation method, and then perform a heat treatment to evaporate the solvent. In this case, performing the heat treatment under a reduced pressure atmosphere is preferable because the solvent can be removed at a low temperature and in a short time, thereby reducing thermal damage to the EL layer.

[0235] The sacrificial layer 118A and the sacrificial layer 119A may each be formed using a wet film formation method such as spin coating, dipping, spray coating, inkjet, dispensing, screen printing, offset printing, doctor knife method, slit coating, roll coating, curtain coating, or knife coating.

[0236] The sacrificial layers 118A and 119A may each be made of an organic resin such as polyvinyl alcohol (PVA), polyvinyl butyral, polyvinyl pyrrolidone, polyethylene glycol, polyglycerin, pullulan, water-soluble cellulose, or alcohol-soluble polyamide resin. Alternatively, the sacrificial layers 118A and 119A may each be made of a fluororesin such as perfluoropolymer.

[0237] For example, the sacrificial layer 118A can be an organic film (e.g., a PVA film) formed using either a vapor deposition method or the above-mentioned wet film formation method, and the sacrificial layer 119A can be an inorganic film (e.g., a silicon nitride film) formed using a sputtering method.

[0238] Next, a resist mask 190 is formed on the sacrificial layer 119A (FIG. 7C). The resist mask 190 can be formed by applying a photosensitive resin (photoresist) and then performing exposure and development.

[0239] The resist mask may be made of either a positive resist material or a negative resist material.

[0240] The resist mask 190 is provided at a position overlapping the pixel electrode 111. It is preferable that the resist mask 190 has an island-shaped pattern for each sub-pixel.

[0241] Note that the resist mask 190 is preferably provided also in a position overlapping with the conductive layer 123. This can prevent the conductive layer 123 from being damaged during the manufacturing process of the display device. Note that the resist mask 190 does not necessarily have to be provided over the conductive layer 123.

[0242] Next, a part of the sacrificial layer 119A is removed using a resist mask 190 to form the sacrificial layer 119 (FIG. 7D). The sacrificial layer 119 remains on the pixel electrode 111 and the conductive layer 123.

[0243] When etching the sacrificial layer 119A, it is preferable to use etching conditions with a high selectivity so that the sacrificial layer 118A is not removed by the etching. Furthermore, when processing the sacrificial layer 119A, the EL layer 113A is not exposed, so the range of processing methods available is wider than when processing the sacrificial layer 118A. Specifically, even when a gas containing oxygen is used as an etching gas when processing the sacrificial layer 119A, deterioration of the EL layer 113A can be further suppressed.

[0244] Thereafter, the resist mask 190 is removed. For example, the resist mask 190 can be removed by ashing using oxygen plasma. Alternatively, the resist mask 190 can be removed by ashing using oxygen gas and CF ４ , C ４ F ８ , SF ６ , CHF ３ , Cl ２ , H ２ O, BCl ３ Alternatively, a noble gas (also referred to as a rare gas) such as He may be used. Alternatively, the resist mask 190 may be removed by wet etching. At this time, the sacrificial layer 118A is located on the outermost surface and the EL layer 113A is not exposed, so that damage to the EL layer 113A can be suppressed in the process of removing the resist mask 190. Furthermore, the range of options for removing the resist mask 190 can be expanded.

[0245] Next, the sacrificial layer 119 is used as a mask (also called a hard mask) to remove a part of the sacrificial layer 118A, thereby forming the sacrificial layer 118 (FIG. 7D).

[0246] The sacrificial layers 118A and 119A can be processed by wet etching or dry etching, respectively, and are preferably processed by anisotropic etching.

[0247] Compared to the case of using dry etching, the use of wet etching can reduce damage to the EL layer 113A during processing of the sacrificial layers 118A and 119A. When using wet etching, it is preferable to use a chemical solution such as a developer, a tetramethylammonium hydroxide (TMAH) aqueous solution, diluted hydrofluoric acid, oxalic acid, phosphoric acid, acetic acid, nitric acid, or a mixture thereof.

[0248] When dry etching is used, deterioration of the EL layer 113A can be suppressed by not using a gas containing oxygen as an etching gas. ４ , C ４ F ８ , SF ６ , CHF ３ , Cl ２ , H ２ O, BCl ３ It is preferable to use a gas containing a noble gas (also called a rare gas) such as He as the etching gas.

[0249] For example, when an aluminum oxide film formed by ALD is used as the sacrificial layer 118A, CHF ３ The sacrificial layer 118A can be processed by dry etching using He. When an In-Ga-Zn oxide film formed by sputtering is used as the sacrificial layer 119A, the sacrificial layer 119A can be processed by wet etching using diluted phosphoric acid. ４ The sacrificial layer 119A may be processed by dry etching using diluted phosphoric acid and Ar. Alternatively, the sacrificial layer 119A may be processed by wet etching using diluted phosphoric acid. When a tungsten film formed by sputtering is used as the sacrificial layer 119A, SF ６ , C.F. ４ and O ２ , or CF ４ and Cl ２ and O ２ The sacrificial layer 119A can be processed by dry etching using the above.

[0250] Next, the EL layer 113A is processed to form the EL layer 113. For example, the sacrificial layers 119 and 118 are used as hard masks to remove a part of the EL layer 113A, thereby forming the EL layer 113 (FIG. 7D).

[0251] As shown in Fig. 7D, the EL layer 113A can be processed to form a plurality of EL layers 113. That is, the EL layer 113A can be divided into a plurality of EL layers 113. Note that the EL layer 113A does not need to be divided in either the row direction or the column direction. In this case, the EL layer 113 can be formed in a strip shape.

[0252] The EL layer 113A is preferably processed by anisotropic etching, particularly anisotropic dry etching, or wet etching.

[0253] When dry etching is used, deterioration of the EL layer 113A can be suppressed by not using a gas containing oxygen as an etching gas.

[0254] Alternatively, a gas containing oxygen may be used as the etching gas. When the etching gas contains oxygen, the etching rate can be increased. Therefore, etching can be performed under low power conditions while maintaining a sufficiently high etching rate. This can suppress damage to the EL layer 113A. Furthermore, problems such as adhesion of reaction products that occur during etching can be suppressed.

[0255] When dry etching is used, for example, H ２ , C.F. ４ , C ４ F ８ , SF ６ , CHF ３ , Cl ２ , H ２ O, BCl ３ It is preferable to use a gas containing one or more of the following gases as the etching gas: H, Ar, etc., or a noble gas (also called a rare gas) such as He, Ar, etc. Alternatively, it is preferable to use a gas containing one or more of these gases and oxygen as the etching gas. Alternatively, oxygen gas may be used as the etching gas. Specifically, for example, H ２and a gas containing Ar, or CF ４ A gas containing CF and He can be used as an etching gas. ４ A gas containing He and oxygen can be used as the etching gas.

[0256] As described above, in one embodiment of the present invention, the resist mask 190 is formed over the sacrificial layer 119A, and part of the sacrificial layer 119A is removed using the resist mask 190, thereby forming the sacrificial layer 119. Then, part of the EL layer 113A is removed using the sacrificial layer 119 as a hard mask, thereby forming the EL layer 113. Therefore, it can be said that the EL layer 113 is formed by processing the EL layer 113A by photolithography. Note that part of the EL layer 113A may be removed using the resist mask 190. Then, the resist mask 190 may be removed.

[0257] By providing the EL layer 113 in an island shape for each subpixel, it is possible to suppress the occurrence of leakage current between the subpixels, thereby suppressing the deterioration of the display quality of the display device, and also to achieve both high definition and high display quality of the display device.

[0258] Subsequently, an insulating film 125A, which will later become the insulating layer 125, is formed so as to cover the pixel electrode 111, the EL layer 113, the sacrificial layer 118, and the sacrificial layer 119 (FIG. 8A).

[0259] As the insulating film 125A, it is preferable to form an insulating film having a thickness of 3 nm or more, 5 nm or more, or 10 nm or more and 200 nm or less, 150 nm or less, 100 nm or less, or 50 nm or less under conditions in which the substrate temperature is, for example, 60°C or more, 80°C or more, 100°C or more, or 120°C or more and 200°C or less, 180°C or less, 160°C or less, 150°C or less, or 140°C or less.

[0260] The insulating film 125A is preferably an aluminum oxide film formed by, for example, the ALD method.

[0261] Next, an insulating film 127A is formed on the insulating film 125A ( FIG. 8A ). A photosensitive material, such as a photosensitive resin, can be used as the insulating film 127A. The insulating film 127A can be formed using a wet film-forming method, such as spin coating, dipping, spray coating, inkjet printing, dispensing, screen printing, offset printing, doctor knife printing, slit coating, roll coating, curtain coating, or knife coating. It is particularly preferable to form the organic insulating film that will become the insulating layer 127 by spin coating.

[0262] The insulating films 125A and 127A are preferably formed by a method that causes less damage to the EL layer 113. In particular, since the insulating film 125A is formed in contact with the side surface of the EL layer 113, it is preferably formed by a method that causes less damage to the EL layer 113 than the insulating film 127A. Furthermore, the insulating films 125A and 127A are each formed at a temperature lower than the heat resistance temperature of the EL layer 113. The substrate temperature when forming the insulating films 125A and 127A is typically 200° C. or lower, preferably 180° C. or lower, more preferably 160° C. or lower, more preferably 150° C. or lower, and more preferably 140° C. or lower. For example, an aluminum oxide film can be formed as the insulating film 125A by an ALD method. The ALD method is preferable because it can reduce film formation damage and form a film with high coverage.

[0263] Next, the insulating film 127A is processed to form the insulating layer 127 ( FIG. 8B ). For example, when a photosensitive material is used for the insulating film 127A, the insulating layer 127 can be formed by exposing and developing the insulating film 127A. Etching may be performed to adjust the height of the surface of the insulating layer 127. The insulating layer 127 may be processed by ashing using oxygen plasma, for example.

[0264] Subsequently, at least a portion of the insulating film 125A is removed to form the insulating layer 125 (FIG. 8B).

[0265] The insulating film 125A is preferably processed by dry etching. The insulating film 125A is preferably processed by anisotropic etching. The insulating film 125A can be processed using an etching gas that can be used when processing a sacrificial layer.

[0266] Thereafter, the sacrificial layers 119 and 118 are removed, thereby exposing at least a part of the upper surface of the EL layer 113 and the upper surface of the conductive layer 123.

[0267] The sacrificial layer is preferably removed by wet etching, which can reduce damage to the EL layer 113 when the sacrificial layer is removed, compared to when the sacrificial layer is removed by dry etching, for example.

[0268] The sacrificial layer may also be removed by dissolving it in a solvent such as water or alcohol, such as ethyl alcohol, methyl alcohol, isopropyl alcohol (IPA), or glycerin.

[0269] After removing the sacrificial layer, a drying treatment may be performed to remove water contained in the EL layer and water adsorbed on the surface of the EL layer. For example, a heat treatment can be performed in an inert gas atmosphere or a reduced pressure atmosphere. The heat treatment can be performed at a substrate temperature of 50°C or higher and 200°C or lower, preferably 60°C or higher and 150°C or lower, and more preferably 70°C or higher and 120°C or lower. A reduced pressure atmosphere is preferred because it allows drying at a lower temperature.

[0270] Subsequently, the common layer 114 is formed on the insulating layer 125, the insulating layer 127, and the EL layer 113. After that, the common electrode 115 is formed on the common layer 114 (FIG. 8C).

[0271] The common layer 114 can be formed by a method such as a vapor deposition method (including a vacuum deposition method), a transfer method, a printing method, an inkjet method, a coating method, etc. As described above, the common layer 114 can have, for example, an electron injection layer or a hole injection layer.

[0272] For example, sputtering or vacuum deposition can be used to form the common electrode 115. Alternatively, a film formed by deposition and a film formed by sputtering may be stacked.

[0273] Thereafter, a protective layer 131 is formed on the common electrode 115, and colored layers 132R, 132G, and 132B are formed on the protective layer 131 (FIG. 8C). Furthermore, by using a resin layer 122, a substrate 120 is bonded onto the protective layer 131 and the colored layers, thereby manufacturing the display device 100 shown in FIGS. 1B and 2C.

[0274] Examples of methods for forming the protective layer 131 include vacuum deposition, sputtering, CVD, and ALD. The protective layer 131 may have a single layer structure or a multilayer structure.

[0275] [Pixel Layout] The following mainly describes pixel layouts that differ from that shown in FIG. 1A. There are no particular limitations on the arrangement of sub-pixels, and various methods can be applied. Examples of sub-pixel arrangements include a stripe arrangement, an S-stripe arrangement, a matrix arrangement, a delta arrangement, a Bayer arrangement, and a pentile arrangement.

[0276] Examples of the top surface shape of the subpixel include a triangle, a quadrangle (including a rectangle and a square), a polygon such as a pentagon, a polygon with rounded corners, an ellipse, a circle, etc. Here, the top surface shape of the subpixel corresponds to the top surface shape of the light-emitting region of the light-emitting device.

[0277] An S-stripe arrangement is applied to the pixel 110 shown in Fig. 9A. The pixel 110 shown in Fig. 9A is composed of three subpixels: subpixels 110a, 110b, and 110c. For example, as shown in Fig. 11A, the subpixel 110a may be a blue subpixel B, the subpixel 110b may be a red subpixel R, and the subpixel 110c may be a green subpixel G.

[0278] The pixel 110 shown in FIG. 9B includes a subpixel 110a having a generally trapezoidal top surface shape with rounded corners, a subpixel 110b having a generally triangular top surface shape with rounded corners, and a subpixel 110c having a generally rectangular or hexagonal top surface shape with rounded corners. Furthermore, the subpixel 110a has a larger light-emitting area than the subpixel 110b. In this manner, the shape and size of each subpixel can be determined independently. For example, the more reliable the light-emitting device, the smaller the size can be. For example, as shown in FIG. 11B, the subpixel 110a may be a green subpixel G, the subpixel 110b may be a red subpixel R, and the subpixel 110c may be a blue subpixel B.

[0279] The pixels 124a and 124b shown in Fig. 9C are arranged in a Pentile arrangement. Fig. 9C shows an example in which a pixel 124a having subpixels 110a and 110b and a pixel 124b having subpixels 110b and 110c are arranged alternately. For example, as shown in Fig. 11C, the subpixel 110a may be a red subpixel R, the subpixel 110b may be a green subpixel G, and the subpixel 110c may be a blue subpixel B.

[0280] The pixels 124a and 124b shown in Figures 9D and 9E are arranged in a delta configuration. The pixel 124a has two subpixels (subpixels 110a and 110b) in the top row (first row) and one subpixel (subpixel 110c) in the bottom row (second row). The pixel 124b has one subpixel (subpixel 110c) in the top row (first row) and two subpixels (subpixels 110a and 110b) in the bottom row (second row). For example, as shown in Figure 11D, the subpixel 110a may be a red subpixel R, the subpixel 110b may be a green subpixel G, and the subpixel 110c may be a blue subpixel B.

[0281] FIG. 9D shows an example in which each subpixel has a substantially rectangular top surface shape with rounded corners, and FIG. 9E shows an example in which each subpixel has a circular top surface shape.

[0282] 9F shows an example in which subpixels of each color are arranged in a zigzag pattern. Specifically, when viewed from above, the positions of the upper edges of two subpixels arranged in the column direction (e.g., subpixels 110a and 110b, or subpixels 110b and 110c) are misaligned. For example, as shown in FIG. 11E, the subpixel 110a may be a red subpixel R, the subpixel 110b may be a green subpixel G, and the subpixel 110c may be a blue subpixel B.

[0283] In photolithography, the finer the pattern to be processed, the more significant the effect of light diffraction becomes. This reduces the fidelity of the photomask pattern when it is transferred by exposure, making it difficult to process the resist mask into the desired shape. Therefore, even if the photomask pattern is rectangular, it is likely to have rounded corners. As a result, the top surface shape of the subpixel may become a polygon with rounded corners, an ellipse, a circle, or the like.

[0284] Furthermore, in a manufacturing method of a display device according to one embodiment of the present invention, the EL layer is processed into an island shape using a resist mask. The resist film formed on the EL layer needs to be cured at a temperature lower than the heat resistance temperature of the EL layer. Therefore, depending on the heat resistance temperature of the material for the EL layer and the curing temperature of the resist material, the resist film may not be cured sufficiently. A resist film that is not cured sufficiently may have a shape that deviates from the desired shape during processing. As a result, the top surface shape of the EL layer may become a polygon with rounded corners, an ellipse, a circle, or the like. For example, when a resist mask with a square top surface shape is formed, a resist mask with a circular top surface shape may be formed, resulting in a circular top surface shape of the EL layer.

[0285] In order to form the top surface of the EL layer into a desired shape, a technique for correcting a mask pattern in advance (OPC (Optical Proximity Correction) technique) may be used so that the design pattern and the transfer pattern coincide with each other. Specifically, the OPC technique adds a correction pattern to the corners of figures on the mask pattern.

[0286] In addition, even in the pixel 110 to which the stripe arrangement shown in FIG. 1A is applied, the order of arrangement of the subpixels is not particularly limited. For example, as shown in FIG. 11F, the subpixels may be arranged in the order of green subpixel G, red subpixel R, and blue subpixel B.

[0287] As shown in Figures 10A to 10H, a pixel can be configured to have four types of sub-pixels.

[0288] The pixel 110 shown in FIGS. 10A to 10C is configured in a stripe arrangement.

[0289] FIG. 10A shows an example in which each subpixel has a rectangular top surface shape, FIG. 10B shows an example in which each subpixel has a top surface shape that is a combination of two semicircles and a rectangle, and FIG. 10C shows an example in which each subpixel has an elliptical top surface shape.

[0290] The pixels 110 shown in FIGS. 10D to 10F are arranged in a matrix.

[0291] Figure 10D is an example in which each subpixel has a square top surface shape, Figure 10E is an example in which each subpixel has an approximately square top surface shape with rounded corners, and Figure 10F is an example in which each subpixel has a circular top surface shape.

[0292] 10G and 10H show an example in which one pixel 110 is configured in two rows and three columns.

[0293] 10G has three subpixels (subpixels 110a, 110b, and 110c) in the top row (first row) and one subpixel (subpixel 110d) in the bottom row (second row). In other words, pixel 110 has subpixel 110a in the left column (first column), subpixel 110b in the center column (second column), subpixel 110c in the right column (third column), and subpixel 110d across these three columns.

[0294] The pixel 110 shown in FIG. 10H has three subpixels (subpixels 110a, 110b, and 110c) in the top row (first row) and three subpixels 110d in the bottom row (second row). In other words, the pixel 110 has subpixels 110a and 110d in the left column (first column), subpixels 110b and 110d in the center column (second column), and subpixels 110c and 110d in the right column (third column). By aligning the subpixels in the top and bottom rows as shown in FIG. 10H, it is possible to efficiently remove dust and other particles that may occur during the manufacturing process. Therefore, a display device with high display quality can be provided.

[0295] The pixel 110 shown in Figures 10A to 10H is composed of four subpixels: subpixels 110a, 110b, 110c, and 110d. Each of the subpixels 110a, 110b, 110c, and 110d has an emissive device that emits light of a different color. The subpixels 110a, 110b, 110c, and 110d may be subpixels of four colors: R, G, B, and white (W), subpixels of four colors: R, G, B, and Y, or subpixels of R, G, B, and infrared light (IR). For example, as shown in Figures 11G to 11J, the subpixels 110a, 110b, 110c, and 110d may be subpixels of red, green, blue, and white, respectively.

[0296] As described above, in the display device of one embodiment of the present invention, various layouts can be applied to pixels each including a subpixel having a light-emitting device.

[0297] As described above, in the manufacturing method of the display device of this embodiment, the island-shaped EL layer is formed by forming the EL layer on the entire surface and then processing it, rather than using a metal mask having a fine pattern. Therefore, the size of the island-shaped EL layer can be made smaller than that of the EL layer formed using a metal mask. Therefore, it is possible to realize a high-definition display device or a display device with a high aperture ratio, which has been difficult to achieve until now.

[0298] The display device of one embodiment of the present invention includes a light-emitting device having a tandem structure, which allows easy adjustment of carrier balance and reduces the change in emission color between low and high luminance. Furthermore, the provision of an island-shaped EL layer for each subpixel can prevent leakage current from occurring between the subpixels. This can prevent degradation in the display quality of the display device. Furthermore, the display device can achieve both high resolution and high display quality.

[0299] This embodiment mode can be combined with other embodiment modes as appropriate. In addition, in this specification, when a plurality of configuration examples are shown in one embodiment mode, the configuration examples can be combined as appropriate.

[0300] Embodiment 2 In this embodiment, a display device of one embodiment of the present invention will be described with reference to FIGS.

[0301] The display device of this embodiment can be a high-resolution display device or a large-sized display device. Therefore, the display device of this embodiment can be used in electronic devices having relatively large screens, such as television devices, desktop or notebook personal computers, computer monitors, digital signage, and large game machines such as pachinko machines, as well as in display units of digital cameras, digital video cameras, digital photo frames, mobile phones, portable game machines, personal digital assistants, and sound reproducing devices.

[0302] In the display device of this embodiment, a tandem structure is applied to the light-emitting devices, so that the change in chromaticity between light emission at low luminance and light emission at high luminance is small. Furthermore, in the display device of this embodiment, the EL layers of each light-emitting device are separated, so that the occurrence of crosstalk between adjacent subpixels is suppressed. Therefore, a display device with high display quality can be realized.

[0303] [Display Device 100A] FIG. 12 shows a perspective view of the display device 100A, and FIG. 13A shows a cross-sectional view of the display device 100A.

[0304] The display device 100A has a configuration in which a substrate 152 and a substrate 151 are bonded together. In Fig. 12, the substrate 152 is clearly indicated by a dashed line.

[0305] The display device 100A includes a display portion 162, a connection portion 140, a circuit 164, wiring 165, and the like. Fig. 12 shows an example in which an IC 173 and an FPC 172 are mounted on the display device 100A. Therefore, the configuration shown in Fig. 12 can also be said to be a display module including the display device 100A, an IC (integrated circuit), and an FPC.

[0306] The connection portion 140 is provided on the outside of the display portion 162. The connection portion 140 can be provided along one side or multiple sides of the display portion 162. There may be one or more connection portions 140. Fig. 12 shows an example in which the connection portion 140 is provided so as to surround the four sides of the display portion. The connection portion 140 electrically connects the common electrode of the light-emitting device and the conductive layer, and can supply a potential to the common electrode.

[0307] The circuit 164 can be, for example, a scanning line driver circuit.

[0308] 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 input to the wiring 165 from the IC 173.

[0309] 12 shows an example in which an IC 173 is provided on the substrate 151 by a chip-on-glass (COG) method or a chip-on-film (COF) method. The IC 173 may be, for example, an IC having a scanning line driver circuit or a signal line driver circuit. The display device 100A and the display module may not include an IC. Alternatively, the IC may be mounted on an FPC by a COF method or the like.

[0310] Figure 13A shows an example of a cross section of the display device 100A when cutting a portion of the area including the FPC 172, a portion of the circuit 164, a portion of the display unit 162, a portion of the connection unit 140, and a portion of the area including the end portion.

[0311] The display device 100A shown in FIG. 13A includes, between a substrate 151 and a substrate 152, a transistor 201, a transistor 205, a light-emitting device 130, a colored layer 132R that transmits red light, a colored layer 132G that transmits green light, and a colored layer 132B that transmits blue light. The light-emitting device 130 can be configured to emit white light. Light emitted from the light-emitting device 130 that overlaps the colored layer 132R is extracted as red light to the outside of the display device 100A through the colored layer 132R. Similarly, light emitted from the light-emitting device 130 that overlaps the colored layer 132G is extracted as green light to the outside of the display device 100A through the colored layer 132G. Light emitted from the light-emitting device 130 that overlaps the colored layer 132B is extracted as blue light to the outside of the display device 100A through the colored layer 132B.

[0312] The pixel layout exemplified in the first embodiment can be applied to the display device 100A.

[0313] The light-emitting devices included in the sub-pixels that emit light of each color may all have the same configuration, for example, a configuration that emits white light. Specifically, the EL layers 113 included in the light-emitting devices may all have the same configuration. On the other hand, since the EL layers 113 included in each light-emitting device are separated, it is possible to suppress the occurrence of leakage current between the light-emitting devices. This improves the display quality of the display device.

[0314] The light-emitting device 130 has the same structure as the laminated structure shown in Fig. 1B except for the configuration of the pixel electrodes. For details of the light-emitting device 130, refer to the first embodiment.

[0315] The light-emitting device 130 includes a conductive layer 126 and a conductive layer 129 on the conductive layer 126. One or both of the conductive layer 126 and the conductive layer 129 can be called a pixel electrode.

[0316] The conductive layer 126 is connected to the conductive layer 222b of the transistor 205 through an opening provided in the insulating layer 214. In the display device 100A, the ends of the conductive layer 126 and the conductive layer 129 are aligned or approximately aligned, but this is not limiting. For example, the conductive layer 129 may be provided so as to cover the end of the conductive layer 126. Each of the conductive layer 126 and the conductive layer 129 preferably has a conductive layer that functions as a reflective electrode. Furthermore, one or both of the conductive layer 126 and the conductive layer 129 may have a conductive layer that functions as a transparent electrode.

[0317] The conductive layer 126 is formed to cover the opening provided in the insulating layer 214. A layer 128 is filled into the recess of the conductive layer 126.

[0318] The layer 128 has a function of planarizing the recessed portion of the conductive layer 126. A conductive layer 129 electrically connected to the conductive layer 126 is provided over the conductive layer 126 and the layer 128. Therefore, a region overlapping with the recessed portion of the conductive layer 126 can also be used as a light-emitting region, and the aperture ratio of the pixel can be increased.

[0319] The layer 128 may be an insulating layer or a conductive layer. Various inorganic insulating materials, organic insulating materials, and conductive materials can be used as appropriate for the layer 128. In particular, the layer 128 is preferably formed using an insulating material.

[0320] An insulating layer containing an organic material can be suitably used as the layer 128. For example, acrylic resin, polyimide resin, epoxy resin, polyamide resin, polyimideamide resin, siloxane resin, benzocyclobutene resin, phenol resin, precursors of these resins, or the like can be used as the layer 128. Alternatively, a photosensitive resin can be used as the layer 128. The photosensitive resin can be a positive-type material or a negative-type material.

[0321] By using a photosensitive resin, the layer 128 can be formed only by exposure and development steps, and the influence of a dry etching method, a wet etching method, or the like on the surface of the conductive layer 126 can be reduced. Furthermore, by forming the layer 128 using a negative photosensitive resin, the layer 128 can sometimes be formed using the same photomask (exposure mask) as that used to form the openings in the insulating layer 214.

[0322] The upper surface of the conductive layer 129 is covered with the EL layer 113. When viewed from above, the entire area where the conductive layer 129 and the EL layer 113 overlap can be used as the light-emitting area of ​​the light-emitting device 130, thereby increasing the aperture ratio of the pixel. Note that the EL layer 113 may cover at least a portion of the side surface of the conductive layer 129. Alternatively, the EL layer 113 may cover only a portion of the upper surface of the conductive layer 129. In other words, a portion of the upper surface of the conductive layer 129 does not have to be covered by the EL layer 113.

[0323] The side surfaces of the EL layer 113 are covered with an insulating layer 125, and overlap with an insulating layer 127 via the insulating layer 125. A common layer 114 is provided on the EL layer 113, the insulating layer 125, and the insulating layer 127, and a common electrode 115 is provided on the common layer 114. The common layer 114 and the common electrode 115 are each a continuous film provided in common to a plurality of light-emitting devices.

[0324] In addition, a protective layer 131 is provided on the light-emitting device 130. By providing the protective layer 131 that covers the light-emitting device, it is possible to prevent impurities such as water from entering the light-emitting device, thereby improving the reliability of the light-emitting device.

[0325] The protective layer 131 and the substrate 152 are bonded via an adhesive layer 142. A solid sealing structure, a hollow sealing structure, or the like can be applied to seal the light-emitting device. In FIG. 13A , the space between the substrates 152 and 151 is filled with the adhesive layer 142, and a solid sealing structure is applied. Alternatively, the space may be filled with an inert gas (such as nitrogen or argon), and a hollow sealing structure may be applied. In this case, the adhesive layer 142 may be provided so as not to overlap with the light-emitting device. Alternatively, the space may be filled with a resin different from the frame-shaped adhesive layer.

[0326] In the connection portion 140, a conductive layer 123 is provided on the insulating layer 214. In this example, the conductive layer 123 has a stacked structure of a conductive film obtained by processing the same conductive film as the conductive layer 126 and a conductive film obtained by processing the same conductive film as the conductive layer 129. The side surfaces of the conductive layer 123 are covered with an insulating layer 125 and overlap with the insulating layer 127 via the insulating layer 125. In addition, a common layer 114 is provided on the conductive layer 123, and a common electrode 115 is provided on the common layer 114. The conductive layer 123 and the common electrode 115 are electrically connected via the common layer 114. Note that the common layer 114 does not necessarily have to be formed in the connection portion 140. In this case, the conductive layer 123 and the common electrode 115 are in direct contact with each other and are electrically connected.

[0327] The display device 100A is a top-emission type. Light emitted from the light-emitting device is emitted toward the substrate 152. The substrate 152 is preferably made of a material that is highly transparent to visible light.

[0328] The pixel electrode contains a material that reflects visible light, and the counter electrode (common electrode 115) contains a material that transmits visible light.

[0329] The stacked structure from the substrate 151 to the insulating layer 214 corresponds to the layer 101 including the transistor in Embodiment 1.

[0330] The transistor 201 and the transistor 205 are both formed over a substrate 151. These transistors can be manufactured using the same material and through the same process.

[0331] An insulating layer 211, an insulating layer 213, an insulating layer 215, and an insulating layer 214 are provided over the substrate 151 in this order. A part of the insulating layer 211 functions as a gate insulating layer for each transistor. A part of the insulating layer 213 functions as a gate insulating layer for each transistor. The insulating layer 215 is provided to cover the transistor. The insulating layer 214 is provided to cover the transistor and functions as a planarization layer. Note that the number of gate insulating layers and the number of insulating layers covering the transistors are not limited, and each may be a single layer or two or more layers.

[0332] At least one insulating layer covering the transistor is preferably made of a material that is resistant to the diffusion of impurities such as water and hydrogen. This allows the insulating layer to function as a barrier layer. With this structure, it is possible to effectively prevent impurities from diffusing into the transistor from the outside, thereby improving the reliability of the display device.

[0333] It is preferable to use an inorganic insulating film for each of the insulating layers 211, 213, and 215. Examples of the inorganic insulating film that can be used include a silicon nitride film, a silicon oxynitride film, a silicon oxide film, a silicon nitride oxide film, an aluminum oxide film, and an aluminum nitride film. Alternatively, a hafnium oxide film, an yttrium oxide film, a zirconium oxide film, a gallium oxide film, a tantalum oxide film, a magnesium oxide film, a lanthanum oxide film, a cerium oxide film, and a neodymium oxide film may also be used. Two or more of the above insulating films may be stacked.

[0334] An organic insulating layer is suitable for the insulating layer 214, which functions as a planarization layer. Materials that can be used for the organic insulating layer include acrylic resin, polyimide resin, epoxy resin, polyamide resin, polyimideamide resin, siloxane resin, benzocyclobutene resin, phenolic resin, and precursors of these resins. The insulating layer 214 may also have a laminated structure of an organic insulating layer and an inorganic insulating film. The outermost layer of the insulating layer 214 preferably functions as an etching protection film. This can prevent recesses from being formed in the insulating layer 214 during processing of the conductive layer 126, the conductive layer 129, or the like. Alternatively, recesses may be formed in the insulating layer 214 during processing of the conductive layer 126, the conductive layer 129, or the like.

[0335] The transistor 201 and the transistor 205 each include a conductive layer 221 that functions as a gate, an insulating layer 211 that functions as a gate insulating layer, conductive layers 222a and 222b that function as a source and a drain, a semiconductor layer 231, an insulating layer 213 that functions as a gate insulating layer, and a conductive layer 223 that functions as a gate. Here, the same hatching pattern is applied to multiple layers obtained by processing the same conductive film. The insulating layer 211 is located between the conductive layer 221 and the semiconductor layer 231. The insulating layer 213 is located between the conductive layer 223 and the semiconductor layer 231.

[0336] The structure of the transistor included in the display device of this embodiment is not particularly limited. For example, a planar transistor, a staggered transistor, an inverted staggered transistor, or the like can be used. Furthermore, either a top-gate transistor or a bottom-gate transistor structure may be used. Alternatively, gates may be provided above and below a semiconductor layer in which a channel is formed.

[0337] The transistor 201 and the transistor 205 have a structure in which a semiconductor layer in which a channel is formed is sandwiched between two gates. The two gates may be connected and the same signal may be supplied to drive the transistor. Alternatively, the threshold voltage of the transistor may be controlled by applying a potential for controlling the threshold voltage to one of the two gates and a potential for driving to the other.

[0338] The crystallinity of a semiconductor material used for a transistor is not particularly limited, and any of an amorphous semiconductor, a single-crystal semiconductor, and a semiconductor having crystallinity other than a single crystal (a microcrystalline semiconductor, a polycrystalline semiconductor, or a semiconductor having a crystalline region in part) may be used. The use of a single-crystal semiconductor or a crystalline semiconductor is preferable because it can suppress deterioration of transistor characteristics.

[0339] The semiconductor layer of the transistor preferably includes a metal oxide (also referred to as an oxide semiconductor). That is, the display device of this embodiment preferably includes a transistor using a metal oxide for a channel formation region (hereinafter referred to as an OS transistor).

[0340] Examples of crystalline oxide semiconductors include c-axis-aligned crystalline (CAAC)-OS, nanocrystalline (nc)-OS, and the like.

[0341] Alternatively, a transistor using silicon for a channel formation region (Si transistor) may be used. Examples of silicon include single crystal silicon, polycrystalline silicon, and amorphous silicon. In particular, a transistor having low temperature polysilicon (LTPS) in a semiconductor layer (hereinafter also referred to as an LTPS transistor) may be used. An LTPS transistor has high field-effect mobility and favorable frequency characteristics.

[0342] By using Si transistors such as LTPS transistors, circuits that need to be driven at high frequencies (such as source driver circuits) can be built on the same substrate as the display unit, which simplifies the external circuits mounted on the display device and reduces component and mounting costs.

[0343] An OS transistor has significantly higher field-effect mobility than a transistor using amorphous silicon. Furthermore, an OS transistor has significantly lower source-drain leakage current in an off state (hereinafter also referred to as off-state current), and can hold charge accumulated in a capacitor connected in series with the transistor for a long period of time. Furthermore, the use of an OS transistor can reduce the power consumption of a display device.

[0344] The off-state current of the OS transistor per 1 μm of channel width at room temperature is 1 aA (1×10 −１８ A) Below, 1zA (1×10 −２１ A) or less, or 1 yA (1 x 10 −２４ Note that the off-state current of a Si transistor per 1 μm of channel width at room temperature can be 1 fA (1×10 −１５ A) More than 1pA (1×10 −１２ Therefore, it can be said that the off-state current of an OS transistor is about 10 orders of magnitude lower than that of a Si transistor.

[0345] Furthermore, to increase the emission luminance of a light-emitting device included in a pixel circuit, it is necessary to increase the amount of current flowing through the light-emitting device. To achieve this, it is necessary to increase the source-drain voltage of a driving transistor included in the pixel circuit. Since an OS transistor has a higher source-drain withstand voltage than a Si transistor, a high voltage can be applied between the source and drain of the OS transistor. Therefore, by using an OS transistor as the driving transistor included in a pixel circuit, it is possible to increase the amount of current flowing through the light-emitting device and increase the emission luminance of the light-emitting device.

[0346] Furthermore, when the transistor operates in the saturation region, the OS transistor can reduce the change in source-drain current with respect to a change in gate-source voltage compared to a Si transistor. Therefore, by using an OS transistor as a driving transistor included in a pixel circuit, the current flowing between the source and drain can be precisely controlled by changing the gate-source voltage, thereby controlling the amount of current flowing through the light-emitting device. This allows for a greater number of gray levels to be displayed in the pixel circuit.

[0347] Furthermore, in terms of the saturation characteristics of the current that flows when a transistor operates in the saturation region, an OS transistor can pass a more stable current (saturation current) than a Si transistor, even when the source-drain voltage gradually increases. Therefore, by using an OS transistor as a driving transistor, a stable current can be passed through a light-emitting device, even when the current-voltage characteristics of an EL device vary. In other words, when an OS transistor operates in the saturation region, the source-drain current of the OS transistor remains almost unchanged even when the source-drain voltage increases, thereby stabilizing the light-emitting luminance of the light-emitting device.

[0348] As described above, by using an OS transistor for a driving transistor included in a pixel circuit, it is possible to achieve "suppression of black floating," "increase in light emission luminance," "multiple gradations," "suppression of variations in light-emitting devices," and the like.

[0349] The metal oxide used in the semiconductor layer preferably contains, for example, indium, M (wherein M is one or more elements selected from gallium, aluminum, silicon, boron, yttrium, tin, copper, vanadium, beryllium, titanium, iron, nickel, germanium, zirconium, molybdenum, lanthanum, cerium, neodymium, hafnium, tantalum, tungsten, and magnesium), and zinc. In particular, M is preferably one or more elements selected from aluminum, gallium, yttrium, and tin.

[0350] In particular, it is preferable to use an oxide containing indium (In), gallium (Ga), and zinc (Zn) (also referred to as IGZO) as the semiconductor layer. Alternatively, it is preferable to use an oxide containing indium, tin, and zinc. Alternatively, it is preferable to use an oxide containing indium, gallium, tin, and zinc. Alternatively, it is preferable to use an oxide containing indium (In), aluminum (Al), and zinc (Zn) (also referred to as IAZO). Alternatively, it is preferable to use an oxide containing indium (In), aluminum (Al), gallium (Ga), and zinc (Zn) (also referred to as IAGZO).

[0351] When the semiconductor layer is an In-M-Zn oxide, the atomic ratio of In in the In-M-Zn oxide is preferably equal to or greater than the atomic ratio of M. The atomic ratio of metal elements in such an In-M-Zn oxide may be In:M:Zn=1:1:1 or a composition thereabout, In:M:Zn=1:1:1.2 or a composition thereabout, In:M:Zn=1:3:2 or a composition thereabout, In:M:Zn=1:3:4 or a composition thereabout, In:M:Zn=2:1:3 or a composition thereabout, In:M:Zn=3:1:2 or a composition thereabout, or In:M:Zn=4:2:3. or a composition in the vicinity thereof, In:M:Zn = 4:2:4.1 or a composition in the vicinity thereof, In:M:Zn = 5:1:3 or a composition in the vicinity thereof, In:M:Zn = 5:1:6 or a composition in the vicinity thereof, In:M:Zn = 5:1:7 or a composition in the vicinity thereof, In:M:Zn = 5:1:8 or a composition in the vicinity thereof, In:M:Zn = 6:1:6 or a composition in the vicinity thereof, In:M:Zn = 5:2:5 or a composition in the vicinity thereof, etc. Note that a composition in the vicinity thereof includes a range of ±30% of the desired atomic ratio.

[0352] For example, when describing a composition having an atomic ratio of In:Ga:Zn=4:2:3 or thereabout, this includes a case where, when In is taken as 4, Ga is 1 to 3 and Zn is 2 to 4. Furthermore, when describing a composition having an atomic ratio of In:Ga:Zn=5:1:6 or thereabout, this includes a case where, when In is taken as 5, Ga is more than 0.1 and 2 or less and Zn is 5 to 7. Furthermore, when describing a composition having an atomic ratio of In:Ga:Zn=1:1:1 or thereabout, this includes a case where, when In is taken as 1, Ga is more than 0.1 and 2 or less and Zn is more than 0.1 and 2 or less.

[0353] The transistors included in the circuit 164 may have the same structure as or different from the transistors included in the display portion 162. The transistors included in the circuit 164 may all have the same structure or may have two or more types. Similarly, the transistors included in the display portion 162 may all have the same structure or may have two or more types.

[0354] All the transistors included in the display portion 162 may be OS transistors, all the transistors included in the display portion 162 may be Si transistors, or some of the transistors included in the display portion 162 may be OS transistors and the rest may be Si transistors.

[0355] For example, by using both an LTPS transistor and an OS transistor in the display portion 162, a display device with low power consumption and high driving capability can be realized. A structure in which an LTPS transistor and an OS transistor are combined is sometimes referred to as LTPO. As a more preferable example, it is preferable to use an OS transistor as a transistor that functions as a switch for controlling conduction / non-conduction between wirings and to use an LTPS transistor as a transistor for controlling current.

[0356] For example, one of the transistors included in the display portion 162 functions as a transistor for controlling a current flowing through a light-emitting device and can also be called a driving transistor. One of the source and drain of the driving transistor is electrically connected to a pixel electrode of the light-emitting device. It is preferable to use an LTPS transistor as the driving transistor. This allows a large current to flow through the light-emitting device in the pixel circuit.

[0357] On the other hand, another transistor included in the display portion 162 functions as a switch for controlling pixel selection / non-selection and can also be called a selection transistor. The gate of the selection transistor is electrically connected to a gate line, and one of the source and drain is electrically connected to a source line (signal line). An OS transistor is preferably used as the selection transistor. This allows the gradation of a pixel to be maintained even when the frame frequency is significantly reduced (for example, 1 fps or less). Therefore, power consumption can be reduced by stopping the driver when displaying a still image.

[0358] As described above, the display device of one embodiment of the present invention can have a high aperture ratio, high definition, high display quality, and low power consumption.

[0359] A display device according to one embodiment of the present invention includes an OS transistor and a light-emitting device with a metal maskless (MML) structure. This structure can significantly reduce leakage current that may flow through the transistor and leakage current that may flow between adjacent light-emitting devices (also referred to as lateral leakage current or side leakage current). Furthermore, when an image is displayed on the display device, the viewer can observe one or more of image clarity, image sharpness, high saturation, and a high contrast ratio. The extremely low leakage current that may flow through the transistor and lateral leakage current between the light-emitting devices can minimize light leakage during black display.

[0360] 13B and 13C show other examples of the structure of the transistor.

[0361] The transistor 209 and the transistor 210 each include a conductive layer 221 functioning as a gate, an insulating layer 211 functioning as a gate insulating layer, a semiconductor layer 231 including a channel formation region 231i and a pair of low-resistance regions 231n, a conductive layer 222a connected to one of the pair of low-resistance regions 231n, a conductive layer 222b connected to the other of the pair of low-resistance regions 231n, an insulating layer 225 functioning as a gate insulating layer, a conductive layer 223 functioning as a gate, and an insulating layer 215 covering the conductive layer 223. The insulating layer 211 is located between the conductive layer 221 and the channel formation region 231i. The insulating layer 225 is located at least between the conductive layer 223 and the channel formation region 231i. Furthermore, an insulating layer 218 covering the transistor may be provided.

[0362] 13B shows an example in which the insulating layer 225 covers the top surface and side surfaces of the semiconductor layer 231. The conductive layer 222a and the conductive layer 222b are connected to the low-resistance region 231n through openings provided in the insulating layer 225 and the insulating layer 215, respectively. One of the conductive layer 222a and the conductive layer 222b functions as a source, and the other functions as a drain.

[0363] 13C , the insulating layer 225 overlaps with the channel formation region 231i of the semiconductor layer 231 but does not overlap with the low-resistance region 231n. For example, the insulating layer 225 is processed using the conductive layer 223 as a mask, thereby manufacturing the structure shown in FIG. 13C . In FIG. 13C , the insulating layer 215 is provided to cover the insulating layer 225 and the conductive layer 223, and the conductive layer 222a and the conductive layer 222b are connected to the low-resistance region 231n through openings in the insulating layer 215.

[0364] A connection portion 204 is provided in a region of the substrate 151 where the substrate 152 does not overlap. In the connection portion 204, the wiring 165 is electrically connected to the FPC 172 via a conductive layer 166 and a connection layer 242. The conductive layer 166 has an example of a stacked structure of a conductive film obtained by processing the same conductive film as the conductive layer 126 and a conductive film obtained by processing the same conductive film as the conductive layer 129. The conductive layer 166 is exposed on the top surface of the connection portion 204. This allows the connection portion 204 and the FPC 172 to be electrically connected via the connection layer 242.

[0365] It is preferable to provide a light-shielding layer 117 on the surface of substrate 152 facing substrate 151. Furthermore, colored layers 132R and 132G may be provided on the surface of substrate 152 facing substrate 151. In Fig. 13A, when viewed from the substrate 152 as a reference, colored layers 132R and 132G are provided so as to cover a portion of light-shielding layer 117.

[0366] The substrate 151 and the substrate 152 can be formed using any of the materials that can be used for the substrate 120 described in Embodiment 1. Various components that can be disposed on the outside of the substrate 120 can also be applied to the outside of the substrate 151 or the substrate 152.

[0367] For the adhesive layer 142, any of the materials that can be used for the resin layer 122 shown in Embodiment Mode 1 can be used.

[0368] The connection layer 242 may be an anisotropic conductive film (ACF), an anisotropic conductive paste (ACP), or the like.

[0369] Materials that can be used for conductive layers such as the gate, source, and drain of a transistor, as well as various wirings and electrodes that constitute a display device include metals such as aluminum, titanium, chromium, nickel, copper, yttrium, zirconium, molybdenum, silver, tantalum, and tungsten, and alloys containing these metals as main components, etc. Films containing these materials can be used as a single layer or a stacked layer structure.

[0370] Examples of light-transmitting conductive materials include conductive oxides such as indium oxide, indium tin oxide, indium zinc oxide, zinc oxide, and zinc oxide containing gallium, or graphene. Alternatively, metal materials such as gold, silver, platinum, magnesium, nickel, tungsten, chromium, molybdenum, iron, cobalt, copper, palladium, and titanium, or alloy materials containing such metal materials, can be used. Alternatively, nitrides of such metal materials (e.g., titanium nitride) can be used. When using metal materials or alloy materials (or their nitrides), it is preferable to thin them sufficiently to ensure light-transmitting properties. A stacked film of the above materials can also be used as the conductive layer. For example, a stacked film of an alloy of silver and magnesium and indium tin oxide is preferable because it can enhance conductivity. These materials can also be used for conductive layers such as various wirings and electrodes constituting display devices, and conductive layers (conductive layers functioning as pixel electrodes or common electrodes) in light-emitting devices.

[0371] Examples of insulating materials that can be used for each insulating layer include resins such as acrylic resin and epoxy resin, and inorganic insulating materials such as silicon oxide, silicon oxynitride, silicon nitride oxide, silicon nitride, and aluminum oxide.

[0372] 14 is different from the display device 100A mainly in that it is a bottom emission type. Note that a description of the same parts as those of the display device 100A will be omitted.

[0373] Light emitted from the light-emitting device is emitted toward the substrate 151. A material that is highly transparent to visible light is preferably used for the substrate 151. On the other hand, the light-transmitting property of the material used for the substrate 152 does not matter.

[0374] In addition, in the display device 100B, the conductive layers 126 and 129 contain a material that transmits visible light, and the common electrode 115 contains a material that reflects visible light.

[0375] A light-shielding layer 117 is preferably formed between the substrate 151 and the transistor 201 and between the substrate 151 and the transistor 205. Fig. 14 shows an example in which the light-shielding layer 117 is provided over the substrate 151, the insulating layer 153 is provided over the light-shielding layer 117, and the transistors 201, 205, and the like are provided over the insulating layer 153.

[0376] Furthermore, in the display device 100B, a coloring layer 132R that transmits red light and a coloring layer 132G that transmits green light are provided between the insulating layer 215 and the insulating layer 214. It is preferable that the ends of the coloring layer 132R and the coloring layer 132G each overlap the light-shielding layer 117. Light emitted from the light-emitting device 130 that overlaps the coloring layer 132R is extracted as red light to the outside of the display device 100B through the coloring layer 132R. Light emitted from the light-emitting device 130 that overlaps the coloring layer 132G is extracted as green light to the outside of the display device 100B through the coloring layer 132G. Although not shown, a coloring layer 132B that transmits blue light is also provided between the insulating layer 215 and the insulating layer 214, and light emitted from the light-emitting device 130 that overlaps the coloring layer 132B is extracted as blue light to the outside of the display device 100B through the coloring layer 132B.

[0377] 15A to 15D show cross-sectional structures of a region 138 including the conductive layer 126, the layer 128, and their surroundings in the display device 100A and the display device 100B.

[0378] 13A and 14 show an example in which the top surface of layer 128 and the top surface of conductive layer 126 are roughly aligned, but the present invention is not limited to this. For example, as shown in Fig. 15A, the top surface of layer 128 may be higher than the top surface of conductive layer 126. In this case, the top surface of layer 128 has a shape that is gently bulging outward in a convex shape toward the center.

[0379] 15B, the upper surface of layer 128 may be lower than the upper surface of conductive layer 126. In this case, the upper surface of layer 128 has a gently sloping shape that is concave toward the center.

[0380] 15C , when the upper surface of layer 128 is higher than the upper surface of conductive layer 126, the upper portion of layer 128 may be formed to extend beyond the recessed portion of conductive layer 126. In this case, part of layer 128 may be formed to cover part of the generally flat region of conductive layer 126.

[0381] 15D, the layer 128 may further have a recess on the top surface of the structure shown in FIG. 15C. The recess has a shape that is gently recessed toward the center.

[0382] This embodiment mode can be combined with other embodiment modes as appropriate.

[0383] Embodiment 3 In this embodiment, a display device of one embodiment of the present invention will be described with reference to FIGS.

[0384] The display device of the present embodiment can be a high-definition display device, and can therefore be used as a display unit for information terminals (wearable devices) such as wristwatches and bracelets, as well as for wearable devices that can be worn on the head, such as VR devices such as head-mounted displays and AR devices such as glasses.

[0385] In the display device of this embodiment, a tandem structure is applied to the light-emitting devices, so that the change in chromaticity between light emission at low luminance and light emission at high luminance is small. Furthermore, in the display device of this embodiment, the EL layers of each light-emitting device are separated, so that crosstalk between adjacent subpixels can be suppressed even in a high-resolution display device. Therefore, a high-resolution and high-quality display device can be realized.

[0386] Specifically, the resolution of the display portion of the display device of one embodiment of the present invention is preferably 1000 ppi or more, 2000 ppi or more, 3000 ppi or more, 5000 ppi or more, or 6000 ppi or more, and preferably 20000 ppi or less, or 30000 ppi or less.

[0387] 16A shows a perspective view of a display module 280. The display module 280 includes a display device 100C and an FPC 290. Note that the display device included in the display module 280 is not limited to the display device 100C, and may be any of display devices 100D to 100G described below.

[0388] The display module 280 has a substrate 291 and a substrate 292. The display module 280 has a display portion 281. The display portion 281 is a region that displays an image in the display module 280, and is a region where light from each pixel provided in a pixel portion 284 (described later) can be viewed.

[0389] 16B is a perspective view schematically illustrating the configuration on the substrate 291 side. A circuit portion 282, a pixel circuit portion 283 on the circuit portion 282, and a pixel portion 284 on the pixel circuit portion 283 are stacked on the substrate 291. A terminal portion 285 for connecting to the FPC 290 is provided in a portion of the substrate 291 that does not overlap with the pixel portion 284. The terminal portion 285 and the circuit portion 282 are electrically connected by a wiring portion 286 composed of a plurality of wirings.

[0390] The pixel section 284 has a plurality of periodically arranged pixels 284a. An enlarged view of one pixel 284a is shown on the right side of Fig. 16B. The pixel 284a includes a sub-pixel 110R that emits red light, a sub-pixel 110G that emits green light, and a sub-pixel 110B that emits blue light, arranged in this order. Regarding pixel layouts applicable to the pixel section 284, reference can be made to Embodiment 1.

[0391] The pixel circuit section 283 has a plurality of pixel circuits 283a arranged periodically.

[0392] One pixel circuit 283a is a circuit that controls the light emission of three light-emitting devices included in one pixel 284a. One pixel circuit 283a may be configured to have three circuits that control the light emission of one light-emitting device. For example, the pixel circuit 283a may be configured to have at least one selection transistor, one current control transistor (drive transistor), and a capacitor element for each light-emitting device. In this case, a gate signal is input to the gate of the selection transistor, and a source signal is input to the source. This realizes an active matrix display device.

[0393] The circuit portion 282 includes a circuit for driving each pixel circuit 283 a of the pixel circuit portion 283. For example, the circuit portion 282 preferably includes one or both of a gate line driver circuit and a source line driver circuit. In addition, the circuit portion 282 may include at least one of an arithmetic circuit, a memory circuit, a power supply circuit, and the like.

[0394] The FPC 290 functions as wiring for supplying a video signal, a power supply potential, or the like from the outside to the circuit portion 282. An IC may be mounted on the FPC 290.

[0395] The display module 280 can be configured such that one or both of the pixel circuit unit 283 and the circuit unit 282 are provided overlapping below the pixel unit 284, thereby enabling the aperture ratio (effective display area ratio) of the display unit 281 to be extremely high. For example, the aperture ratio of the display unit 281 can be 40% or more and less than 100%, preferably 50% or more and 95% or less, and more preferably 60% or more and 95% or less. Furthermore, the pixels 284a can be arranged at an extremely high density, enabling the resolution of the display unit 281 to be extremely high. For example, it is preferable that the pixels 284a be arranged in the display unit 281 at a resolution of 2000 ppi or more, preferably 3000 ppi or more, more preferably 5000 ppi or more, and even more preferably 6000 ppi or more, and 20,000 ppi or less, or 30,000 ppi or less.

[0396] Because such a display module 280 has extremely high resolution, it can be suitably used in VR devices such as head-mounted displays, or in glasses-type AR devices. For example, even in a configuration in which the display unit of the display module 280 is viewed through lenses, the display module 280 has an extremely high-resolution display unit 281, so even when the display unit is enlarged with lenses, the pixels are not visible, allowing for a highly immersive display. Furthermore, the display module 280 is not limited to this, and can be suitably used in electronic devices with relatively small display units. For example, it can be suitably used in the display unit of a wearable electronic device such as a wristwatch.

[0397] 17A includes a substrate 301, a light-emitting device 130, a colored layer 132R, a colored layer 132G, a colored layer 132B, a capacitor 240, and a transistor 310. The subpixel 110R includes the light-emitting device 130 and the colored layer 132R, the subpixel 110G includes the light-emitting device 130 and the colored layer 132G, and the subpixel 110B includes the light-emitting device 130 and the colored layer 132B. The light-emitting device 130 can be configured to emit white light. In the subpixel 110R, light emitted from the light-emitting device 130 is extracted as red light to the outside of the display device 100C via the colored layer 132R. Similarly, in the subpixel 110G, light emitted from the light-emitting device 130 is extracted as green light to the outside of the display device 100C via the colored layer 132G. In the subpixel 110B, light emitted from the light-emitting device 130 is extracted as blue light to the outside of the display device 100C via the colored layer 132B.

[0398] The light-emitting devices included in the sub-pixels that emit light of each color may all have the same configuration, for example, a configuration that emits white light. Specifically, the EL layers 113 included in the light-emitting devices may all have the same configuration. On the other hand, since the EL layers 113 included in each light-emitting device are separated, it is possible to suppress the occurrence of leakage current between the light-emitting devices. This improves the display quality of the display device.

[0399] 16A and 16B. The stacked structure from the substrate 301 to the insulating layer 255b corresponds to the layer 101 including the transistor in Embodiment 1.

[0400] The transistor 310 has a channel formation region in a substrate 301. The substrate 301 can be, for example, a semiconductor substrate such as a single crystal silicon substrate. The transistor 310 includes a part of the substrate 301, a conductive layer 311, a low-resistance region 312, an insulating layer 313, and an insulating layer 314. The conductive layer 311 functions as a gate electrode. The insulating layer 313 is located between the substrate 301 and the conductive layer 311 and functions as a gate insulating layer. The low-resistance region 312 is a region in which the substrate 301 is doped with impurities and functions as one of a source and a drain. The insulating layer 314 is provided to cover a side surface of the conductive layer 311.

[0401] An element isolation layer 315 is provided between two adjacent transistors 310 so as to be embedded in the substrate 301 .

[0402] In addition, an insulating layer 261 is provided to cover the transistor 310 , and a capacitor 240 is provided over the insulating layer 261 .

[0403] The capacitor 240 has a conductive layer 241, a conductive layer 245, and an insulating layer 243 located therebetween. The conductive layer 241 functions as one electrode of the capacitor 240, the conductive layer 245 functions as the other electrode of the capacitor 240, and the insulating layer 243 functions as a dielectric of the capacitor 240.

[0404] The conductive layer 241 is provided over the insulating layer 261 and is buried in the insulating layer 254. The conductive layer 241 is electrically connected to one of the source and drain of the transistor 310 by a plug 271 buried in the insulating layer 261. The insulating layer 243 is provided to cover the conductive layer 241. The conductive layer 245 is provided in a region overlapping with the conductive layer 241 with the insulating layer 243 interposed therebetween.

[0405] An insulating layer 255a is provided to cover the capacitor 240, and an insulating layer 255b is provided on the insulating layer 255a.

[0406] The insulating layer 255a and the insulating layer 255b can be formed using various inorganic insulating films such as an insulating oxide film, an insulating nitride film, an oxynitride insulating film, and an insulating nitride oxide film. The insulating layer 255a is preferably formed using an oxide insulating film or an oxynitride insulating film such as a silicon oxide film, a silicon oxynitride film, or an aluminum oxide film. The insulating layer 255b is preferably formed using a nitride insulating film or a nitride oxide insulating film such as a silicon nitride film or a silicon nitride oxide film. More specifically, the insulating layer 255a is preferably formed using a silicon oxide film, and the insulating layer 255b is preferably formed using a silicon nitride film. The insulating layer 255b preferably functions as an etching protective film. Alternatively, the insulating layer 255a may be formed using a nitride insulating film or a nitride oxide insulating film, and the insulating layer 255b may be formed using an oxide insulating film or an oxynitride insulating film. Although this embodiment shows an example in which a recess is provided in the insulating layer 255b, the insulating layer 255b does not necessarily have a recess.

[0407] The light-emitting device 130 is provided on the insulating layer 255b. In this embodiment, an example is shown in which the light-emitting device 130 has a structure similar to the stacked structure shown in FIG. 1B . The side surfaces of the pixel electrode 111 and the EL layer 113 are each covered with an insulating layer 125, and overlap with the insulating layer 127 via the insulating layer 125. A common layer 114 is provided on the EL layer 113, the insulating layer 125, and the insulating layer 127, and a common electrode 115 is provided on the common layer 114.

[0408] The pixel electrode 111 of the light-emitting device is electrically connected to one of the source and drain of the transistor 310 via a plug 256 embedded in the insulating layers 255a and 255b, a conductive layer 241 embedded in the insulating layer 254, and a plug 271 embedded in the insulating layer 261. The height of the top surface of the insulating layer 255b and the height of the top surface of the plug 256 are the same or approximately the same. Various conductive materials can be used for the plug.

[0409] Furthermore, a protective layer 131 is provided on the light-emitting device 130. Colored layers 132R, 132G, and 132B are provided on the protective layer 131. A substrate 120 is bonded to the colored layers 132R, 132G, and 132B via a resin layer 122. For details of the components from the light-emitting device to the substrate 120, refer to Embodiment 1. The substrate 120 corresponds to the substrate 292 in FIG. 16A .

[0410] The upper end of each pixel electrode 111 is not covered with an insulating layer, which allows the distance between adjacent light-emitting devices to be extremely narrow, thereby enabling a high-definition or high-resolution display device.

[0411] 17B and 17C, a lens array 133 may be provided. By using the lens array 133, light emitted from the light-emitting device 130 can be condensed.

[0412] 17B shows an example in which colored layers 132R, 132G, and 132B are provided on a light-emitting device 130 via a protective layer 131, an insulating layer 134 is provided on the colored layers 132R, 132G, and 132B, and a lens array 133 is provided on the insulating layer 134. By forming the colored layers 132R, 132G, and 132B and the lens array 133 directly on a substrate on which the light-emitting device 130 is formed, it is possible to improve the accuracy of alignment between the light-emitting device and the colored layers or the lens array.

[0413] The insulating layer 134 can be made of either or both of an inorganic insulating film and an organic insulating film. The insulating layer 134 may have a single-layer structure or a multi-layer structure. For example, the same materials that can be used for the protective layer 131 can be used for the insulating layer 134. Since light emitted from the light-emitting device is extracted through the insulating layer 134, it is preferable that the insulating layer 134 have high transparency to visible light.

[0414] 17B, ​​light emitted from the light-emitting device 130 passes through the colored layer and then through the lens array 133 to be extracted to the outside of the display device. By positioning the light-emitting device and the colored layer close to each other, color mixing can be suppressed and viewing angle characteristics can be improved, which is preferable. Alternatively, the lens array 133 may be provided on the light-emitting device 130, and the colored layer may be provided on the lens array 133.

[0415] 17C shows an example in which a substrate 120 provided with colored layers 132R, 132G, 132B, and a lens array 133 is bonded to a protective layer 131 by a resin layer 122. By providing the colored layers 132R, 132G, 132B, and the lens array 133 on the substrate 120, the temperature of the heat treatment in the formation process of these layers can be increased.

[0416] 17C shows an example in which colored layers 132R, 132G, and 132B are provided in contact with the substrate 120, an insulating layer 134 is provided in contact with the colored layers 132R, 132G, and 132B, and a lens array 133 is provided in contact with the insulating layer 134. In FIG.

[0417] 17C , light emitted from the light-emitting device 130 passes through the lens array 133, then passes through the colored layer, and is extracted to the outside of the display device. Note that the lens array 133 may be provided in contact with the substrate 120, the insulating layer 134 may be provided in contact with the lens array 133, and the colored layer may be provided in contact with the insulating layer 134. In this case, light emitted from the light-emitting device 130 passes through the colored layer, then passes through the lens array 133, and is extracted to the outside of the display device.

[0418] The convex surface of the lens array 133 may face the substrate 120 side or the light-emitting device 130 side.

[0419] The lens array 133 can be formed using at least one of an inorganic material and an organic material. For example, a material containing a resin can be used for the lenses. Also, a material containing at least one of an oxide and a sulfide can be used for the lenses. For example, a microlens array can be used as the lens array 133. The lens array 133 can be formed directly on the substrate or the light-emitting device, or a separately formed lens array can be bonded thereto.

[0420] 18 is different from the display device 100C mainly in that the transistor configuration is different. In the following description of the display device, description of parts that are the same as those of the display devices described above may be omitted.

[0421] The transistor 320 is a transistor (OS transistor) in which a metal oxide (also referred to as an oxide semiconductor) is used for a semiconductor layer in which a channel is formed.

[0422] The transistor 320 includes a semiconductor layer 321 , an insulating layer 323 , a conductive layer 324 , a pair of conductive layers 325 , an insulating layer 326 , and a conductive layer 327 .

[0423] 16A and 16B . The stacked structure from the substrate 331 to the insulating layer 255b corresponds to the layer 101 including the transistor in Embodiment 1. The substrate 331 can be an insulating substrate or a semiconductor substrate.

[0424] An insulating layer 332 is provided over a substrate 331. The insulating layer 332 functions as a barrier layer that prevents impurities such as water or hydrogen from diffusing from the substrate 331 to the transistor 320 and prevents oxygen from being released from the semiconductor layer 321 toward the insulating layer 332. The insulating layer 332 can be, for example, a film through which hydrogen or oxygen is less likely to diffuse than a silicon oxide film, such as an aluminum oxide film, a hafnium oxide film, or a silicon nitride film.

[0425] A conductive layer 327 is provided over the insulating layer 332, and an insulating layer 326 is provided to cover the conductive layer 327. The conductive layer 327 functions as a first gate electrode of the transistor 320, and part of the insulating layer 326 functions as a first gate insulating layer. An oxide insulating film such as a silicon oxide film is preferably used for at least a portion of the insulating layer 326 that is in contact with the semiconductor layer 321. The top surface of the insulating layer 326 is preferably planarized.

[0426] The semiconductor layer 321 is provided over the insulating layer 326. The semiconductor layer 321 preferably includes a metal oxide (also referred to as an oxide semiconductor) film having semiconductor characteristics.

[0427] The pair of conductive layers 325 are provided over and in contact with the semiconductor layer 321 and function as a source electrode and a drain electrode.

[0428] An insulating layer 328 is provided to cover top surfaces and side surfaces of the pair of conductive layers 325 and side surfaces of the semiconductor layer 321, and an insulating layer 264 is provided over the insulating layer 328. The insulating layer 328 functions as a barrier layer that prevents impurities such as water or hydrogen from diffusing from the insulating layer 264 or the like to the semiconductor layer 321 and prevents oxygen from being released from the semiconductor layer 321. The insulating layer 328 can be an insulating film similar to the insulating layer 332.

[0429] Openings reaching the semiconductor layer 321 are provided in the insulating layer 328 and the insulating layer 264. Inside the openings, an insulating layer 323 and a conductive layer 324 are buried, which are in contact with side surfaces of the insulating layer 264, the insulating layer 328, and the conductive layer 325 and an upper surface of the semiconductor layer 321. The conductive layer 324 functions as a second gate electrode, and the insulating layer 323 functions as a second gate insulating layer.

[0430] The top surfaces of the conductive layer 324, the insulating layer 323, and the insulating layer 264 are planarized so that their heights are the same or approximately the same, and insulating layers 329 and 265 are provided to cover them.

[0431] The insulating layer 264 and the insulating layer 265 function as interlayer insulating layers. The insulating layer 329 functions as a barrier layer that prevents impurities such as water or hydrogen from diffusing from the insulating layer 265 or the like to the transistor 320. The insulating layer 329 can be formed using an insulating film similar to the insulating layer 328 and the insulating layer 332.

[0432] A plug 274 electrically connected to one of the pair of conductive layers 325 is provided to be embedded in the insulating layer 265, the insulating layer 329, and the insulating layer 264. Here, the plug 274 preferably includes a conductive layer 274a covering the side surfaces of the openings of the insulating layer 265, the insulating layer 329, the insulating layer 264, and the insulating layer 328 and part of the top surface of the conductive layer 325, and a conductive layer 274b in contact with the top surface of the conductive layer 274a. In this case, the conductive layer 274a is preferably made of a conductive material through which hydrogen and oxygen do not easily diffuse.

[0433] The configuration of the display device 100D from the insulating layer 254 to the substrate 120 is the same as that of the display device 100C.

[0434] [Display Device 100E] A display device 100E illustrated in FIG. 19 has a stacked structure of a transistor 310 in which a channel is formed in a substrate 301 and a transistor 320 in which a channel is formed and a semiconductor layer containing metal oxide.

[0435] An insulating layer 261 is provided to cover the transistor 310, and a conductive layer 251 is provided over the insulating layer 261. An insulating layer 262 is provided to cover the conductive layer 251, and a conductive layer 252 is provided over the insulating layer 262. The conductive layers 251 and 252 each function as wirings. An insulating layer 263 and an insulating layer 332 are provided to cover the conductive layer 252, and the transistor 320 is provided over the insulating layer 332. An insulating layer 265 is provided to cover the transistor 320, and a capacitor 240 is provided over the insulating layer 265. The capacitor 240 and the transistor 320 are electrically connected by a plug 274.

[0436] The transistor 320 can be used as a transistor that forms a pixel circuit. The transistor 310 can be used as a transistor that forms a pixel circuit or a driver circuit (gate line driver circuit, source line driver circuit) that drives the pixel circuit. The transistors 310 and 320 can be used as transistors that form various circuits such as an arithmetic circuit or a memory circuit.

[0437] By using this configuration, not only pixel circuits but also driving circuits etc. can be formed directly below the light-emitting device, making it possible to make the display device smaller than when driving circuits are provided around the periphery of the display area.

[0438] [Display Device 100F] A display device 100F shown in FIG. 20 has a stacked structure of a transistor 310A and a transistor 310B, each of which has a channel formed in a semiconductor substrate.

[0439] The display device 100F has a configuration in which a substrate 301B on which a transistor 310B, a capacitor 240, and a light-emitting device are provided and a substrate 301A on which a transistor 310A is provided are bonded together.

[0440] Here, it is preferable to provide an insulating layer 345 on the lower surface of the substrate 301B. It is also preferable to provide an insulating layer 346 on the insulating layer 261 provided on the substrate 301A. The insulating layers 345 and 346 are insulating layers that function as protective layers and can suppress the diffusion of impurities into the substrates 301B and 301A. The insulating layers 345 and 346 can be made of an inorganic insulating film that can be used for the protective layer 131.

[0441] The substrate 301B is provided with a plug 343 that penetrates the substrate 301B and an insulating layer 345. Here, it is preferable to provide an insulating layer 344 to cover the side surface of the plug 343. The insulating layer 344 is an insulating layer that functions as a protective layer and can suppress the diffusion of impurities into the substrate 301B. The insulating layer 344 can be an inorganic insulating film that can be used for the protective layer 131.

[0442] Furthermore, a conductive layer 342 is provided on the back surface (surface opposite to the substrate 120 side) of the substrate 301B, below the insulating layer 345. The conductive layer 342 is preferably provided so as to be embedded in the insulating layer 335. Furthermore, the lower surfaces of the conductive layer 342 and the insulating layer 335 are preferably flattened. Here, the conductive layer 342 is electrically connected to the plug 343.

[0443] On the other hand, in the substrate 301A, a conductive layer 341 is provided on an insulating layer 346. The conductive layer 341 is preferably provided so as to be embedded in the insulating layer 336. In addition, the upper surfaces of the conductive layer 341 and the insulating layer 336 are preferably flattened.

[0444] The substrate 301A and the substrate 301B are electrically connected by bonding the conductive layer 341 and the conductive layer 342. Here, by improving the flatness of the surface formed by the conductive layer 342 and the insulating layer 335 and the surface formed by the conductive layer 341 and the insulating layer 336, the conductive layer 341 and the conductive layer 342 can be favorably bonded to each other.

[0445] It is preferable to use the same conductive material for the conductive layers 341 and 342. For example, a metal film containing an element selected from Al, Cr, Cu, Ta, Ti, Mo, and W, or a metal nitride film containing the aforementioned elements (titanium nitride film, molybdenum nitride film, tungsten nitride film), etc., can be used. In particular, it is preferable to use copper for the conductive layers 341 and 342. This allows the use of Cu-Cu (copper-copper) direct bonding technology (technology that achieves electrical conductivity by connecting Cu (copper) pads together).

[0446] 20 shows an example in which the Cu-Cu direct bonding technique is used to bond the conductive layer 341 and the conductive layer 342, but the present invention is not limited to this. As shown in FIG. 21 , the display device 100G may be configured such that the conductive layer 341 and the conductive layer 342 are bonded via a bump 347.

[0447] 21 , by providing a bump 347 between the conductive layer 341 and the conductive layer 342, the conductive layer 341 and the conductive layer 342 can be electrically connected. The bump 347 can be formed using a conductive material containing, for example, gold (Au), nickel (Ni), indium (In), tin (Sn), or the like. Alternatively, for example, solder may be used as the bump 347. An adhesive layer 348 may be provided between the insulating layer 345 and the insulating layer 346. When the bump 347 is provided, the insulating layer 335 and the insulating layer 336 may not be provided.

[0448] [Display Device 100H] FIG. 22 shows a cross-sectional view of the display device 100H. The display device 100H includes a transistor 310, a transistor 320a, a transistor 320b, a capacitor 240, a light-emitting device 130, a colored layer 132R, a colored layer 132G, a connection portion 140, and the like, between a substrate 301 and a substrate 120. The light-emitting device 130 and the connection portion 140 are provided over an insulating layer 255. The insulating layer 255 can be formed using a material that can be used for the insulating layers 255a and 255b. The insulating layer 255 may have a stacked structure of the insulating layer 255a and the insulating layer 255b. The insulating layer 255 and the substrate 120 are bonded together using a sealant 361. The sealant 361 can be formed using a material that can be used for the adhesive layer 142.

[0449] The light-emitting device 130 of the display device 100H can emit white light. By providing a colored layer so as to have an area overlapping the light-emitting device 130, the display device 100H can perform full-color display. FIG. 22 shows, of the colored layers provided in the display device 100H, a colored layer 132R that transmits red light and a colored layer 132G that transmits green light. FIG. 22 also shows the light-emitting device 130 that overlaps with the colored layer 132R and the light-emitting device 130 that overlaps with the colored layer 132G. Furthermore, FIG. 22 shows the overlapping area between the colored layer 132R and the colored layer 132G with a dotted line.

[0450] The pixel electrode 111 of the light-emitting device 130 is electrically connected to one of the source and drain of the transistor 320b and a conductive layer 245 of the capacitor 240. The conductive layer 241 of the capacitor 240 is electrically connected to one of the source and drain of the transistor 320a. The other of the source and drain of the transistor 320a is electrically connected to one of the source and drain of the transistor 310.

[0451] The transistors 320a and 320b can have a structure similar to that of the transistor 320. That is, the transistor 320 can be, for example, an OS transistor.

[0452] The conductive layer 123 of the connection portion 140 is electrically connected to the conductive layer 351a on the insulating layer 255 via a wiring 355a or the like provided on the insulating layer 354. The conductive layer 351a is electrically connected to the FPC 172a via the connection layer 242a. As described above, the common electrode 115 is electrically connected to the conductive layer 123, and therefore the common electrode 115 is electrically connected to the FPC 172a via the conductive layer 123, the wiring 355a, the conductive layer 351a, the connection layer 242a, or the like. As a result, a potential such as a power supply potential is supplied to the common electrode 115 from outside the display device 100H via the FPC 172a or the like.

[0453] An end portion of the conductive layer 351a is covered with a sacrificial layer 353a. An insulating layer 125a and an insulating layer 127a are stacked in this order on the sacrificial layer 353a.

[0454] The other of the source and the drain of the transistor 320b is electrically connected to a conductive layer 351b over the insulating layer 255 through a wiring 355b or the like provided over the insulating layer 354. The conductive layer 351b is electrically connected to the FPC 172b through the connection layer 242b. As described above, the other of the source and the drain of the transistor 320b is electrically connected to the FPC 172b through the wiring 355b, the conductive layer 351b, the connection layer 242b or the like. As a result, a potential such as a power supply potential is supplied to the other of the source and the drain of the transistor 320b from outside the display device 100H through the FPC 172b or the like.

[0455] Here, the potential supplied to the FPC 172a and the potential supplied to the FPC 172b can be different. For example, a high potential can be supplied to the FPC 172a, and a low potential can be supplied to the FPC 172b. Alternatively, a low potential can be supplied to the FPC 172a, and a high potential can be supplied to the FPC 172b. In this manner, a current can be passed through the light-emitting device 130, causing the light-emitting device 130 to emit light.

[0456] An end portion of the conductive layer 351b is covered with a sacrificial layer 353b. An insulating layer 125b and an insulating layer 127b are stacked in this order on the sacrificial layer 353b.

[0457] The connection layers 242a and 242b can have the same structure as the connection layer 242, and can be made of, for example, ACF. The sacrificial layers 353a and 353b can each have a stacked structure of the sacrificial layers 118 and 119 (see FIG. 6C ). The insulating layers 125a and 125b have the same material as the insulating layer 125, and the insulating layers 127a and 127b have the same material as the insulating layer 127.

[0458] The conductive layer 351 a and the conductive layer 351 b can be formed using the same material and in the same process as the pixel electrode 111 and the conductive layer 123 .

[0459] The connection portion 140 is provided between the display portion in which the light-emitting device 130 is provided and the sealing material 361. On the other hand, the conductive layer 351a, the connection layer 242a, the FPC 172a, the sacrificial layer 353a, the insulating layer 125a, and the insulating layer 127a are provided outside the sealing material 361 (the opposite side to the display portion). Furthermore, the conductive layer 351b, the connection layer 242b, the FPC 172b, the sacrificial layer 353b, the insulating layer 125b, and the insulating layer 127b are provided outside the sealing material 361 (the opposite side to the display portion). The conductive layer 351a, the conductive layer 351b, the connection layer 242a, the connection layer 242b, the FPC 172a, the FPC 172b, the sacrificial layer 353a, the sacrificial layer 353b, the insulating layer 125a, the insulating layer 125b, the insulating layer 127a, and the insulating layer 127b have areas that do not overlap with the substrate 120.

[0460] This embodiment mode can be combined with other embodiment modes as appropriate.

[0461] Embodiment 4 In this embodiment, a light-emitting device that can be used for a display device according to one embodiment of the present invention will be described.

[0462] As shown in FIG. 23A , the light-emitting device has an EL layer 786 between a pair of electrodes (a lower electrode 772 and an upper electrode 788). The EL layer 786 can be composed of multiple layers such as a layer 4420, a light-emitting layer 4411, and a layer 4430. The layer 4420 can have, for example, a layer containing a substance with high electron-injecting properties (electron-injecting layer) and a layer containing a substance with high electron-transporting properties (electron-transporting layer). The light-emitting layer 4411 contains, for example, a light-emitting compound. The layer 4430 can have, for example, a layer containing a substance with high hole-injecting properties (hole-injecting layer) and a layer containing a substance with high hole-transporting properties (hole-transporting layer).

[0463] A structure including the layer 4420, the light-emitting layer 4411, and the layer 4430 provided between a pair of electrodes can function as a single light-emitting unit, and the structure of FIG. 23A is referred to as a single structure in this specification.

[0464] 23B shows a modified example of the EL layer 786 included in the light-emitting device shown in Fig. 23A. Specifically, the light-emitting device shown in Fig. 23B includes a layer 4431 on a lower electrode 772, a layer 4432 on the layer 4431, a light-emitting layer 4411 on the layer 4432, a layer 4421 on the light-emitting layer 4411, a layer 4422 on the layer 4421, and an upper electrode 788 on the layer 4422. For example, when the lower electrode 772 is an anode and the upper electrode 788 is a cathode, the layer 4431 functions as a hole injection layer, the layer 4432 functions as a hole transport layer, the layer 4421 functions as an electron transport layer, and the layer 4422 functions as an electron injection layer. Alternatively, when the lower electrode 772 is a cathode and the upper electrode 788 is an anode, the layer 4431 functions as an electron injection layer, the layer 4432 functions as an electron transport layer, the layer 4421 functions as a hole transport layer, and the layer 4422 functions as a hole injection layer. With such a layer structure, carriers can be efficiently injected into the light-emitting layer 4411, and the efficiency of carrier recombination in the light-emitting layer 4411 can be increased.

[0465] As shown in FIGS. 23C and 23D, a configuration in which a plurality of light-emitting layers (light-emitting layers 4411, 4412, and 4413) are provided between the layer 4420 and the layer 4430 is also a variation of the single structure.

[0466] 23E and 23F, a configuration in which a plurality of light-emitting units (EL layer 786a, EL layer 786b) are connected in series via a charge generation layer 4440 is referred to as a tandem structure in this specification. The tandem structure may also be referred to as a stack structure. The tandem structure makes it possible to provide a light-emitting device capable of emitting light with high brightness.

[0467] 23C and 23D , light-emitting materials that emit light of the same color, or even the same light-emitting material, may be used for the light-emitting layers 4411, 4412, and 4413. For example, a light-emitting material that emits blue light may be used for the light-emitting layers 4411, 4412, and 4413. A color conversion layer may be provided as the layer 785 shown in FIG.

[0468] Furthermore, light-emitting materials that emit light of different colors may be used for the light-emitting layer 4411, the light-emitting layer 4412, and the light-emitting layer 4413. When the lights emitted by the light-emitting layer 4411, the light-emitting layer 4412, and the light-emitting layer 4413 are complementary in color, white light can be obtained. A color filter (also referred to as a coloring layer) may be provided as the layer 785 shown in FIG. 23D. When white light passes through the color filter, light of a desired color can be obtained.

[0469] 23E and 23F , the light-emitting layer 4411 and the light-emitting layer 4412 may be made of light-emitting materials that emit light of the same color, or even the same light-emitting material. Alternatively, the light-emitting layer 4411 and the light-emitting layer 4412 may be made of light-emitting materials that emit light of different colors. When the light emitted by the light-emitting layer 4411 and the light emitted by the light-emitting layer 4412 are complementary colors, white light is obtained. FIG. 23F shows an example in which a layer 785 is further provided. As the layer 785, one or both of a color conversion layer and a color filter (coloring layer) can be used.

[0470] 23C, 23D, 23E, and 23F, the layer 4420 and the layer 4430 may have a laminated structure consisting of two or more layers, as shown in FIG. 23B.

[0471] A structure that produces different luminescent colors (for example, blue (B), green (G), and red (R)) for each light-emitting device is sometimes called an SBS (Side By Side) structure.

[0472] The light-emitting device can emit light of red, green, blue, cyan, magenta, yellow, white, or the like, depending on the material of the EL layer 786. Furthermore, the color purity can be further improved by providing the light-emitting device with a microcavity structure.

[0473] A light-emitting device that emits white light preferably has a configuration in which two or more types of light-emitting materials are included in the light-emitting layer. To obtain white light emission, light-emitting materials are selected such that the light emitted by the two light-emitting materials has a complementary color relationship, or light-emitting materials are selected such that the light emitted by the two or more light-emitting materials combine to produce white light. For example, when white light emission is obtained using two light-emitting layers, a light-emitting device that emits white light as a whole can be obtained by making the emission colors of the two light-emitting layers complementary to each other. Furthermore, when white light emission is obtained using three or more light-emitting layers, a configuration in which the emission colors of the three or more light-emitting layers combine to produce white light as a whole can be obtained.

[0474] The light-emitting layer preferably contains two or more light-emitting materials that emit light of R (red), G (green), B (blue), Y (yellow), O (orange), etc. Alternatively, it is preferable that the light-emitting layer contains two or more light-emitting materials, and the light emitted by each of the light-emitting materials contains spectral components of two or more colors of R, G, and B.

[0475] This embodiment mode can be combined with other embodiment modes as appropriate.

[0476] Embodiment 5 In this embodiment, electronic devices of one embodiment of the present invention will be described with reference to FIGS.

[0477] The electronic devices of this embodiment include the display device of one embodiment of the present invention in their display portions. The display device of one embodiment of the present invention can easily achieve high definition and high resolution. Therefore, the display device of one embodiment of the present invention can be used in the display portions of various electronic devices.

[0478] Examples of electronic devices include electronic devices with relatively large screens such as television sets, desktop or notebook personal computers, computer monitors, digital signage, large game machines such as pachinko machines, as well as digital cameras, digital video cameras, digital photo frames, mobile phones, portable game machines, personal digital assistants, and sound playback devices.

[0479] In particular, the display device of one embodiment of the present invention can be suitably used in electronic devices having a relatively small display area because it can increase the resolution. Examples of such electronic devices include wristwatch-type and bracelet-type information terminals (wearable devices), and head-mounted wearable devices such as VR devices such as head-mounted displays, AR glasses-type devices, and MR devices.

[0480] The display device of one embodiment of the present invention preferably has an extremely high resolution such as HD (1280 × 720 pixels), FHD (1920 × 1080 pixels), WQHD (2560 × 1440 pixels), WQXGA (2560 × 1600 pixels), 4K (3840 × 2160 pixels), or 8K (7680 × 4320 pixels). A resolution of 4K, 8K, or higher is particularly preferable. Furthermore, the pixel density (resolution) of the display device of one embodiment of the present invention is preferably 100 ppi or higher, more preferably 300 ppi or higher, more preferably 500 ppi or higher, more preferably 1000 ppi or higher, more preferably 2000 ppi or higher, more preferably 3000 ppi or higher, more preferably 5000 ppi or higher, and even more preferably 7000 ppi or higher. By using a display device having either or both of high resolution and high definition, it is possible to further enhance the sense of realism and depth in electronic devices for personal use, such as portable or home use. Furthermore, the screen ratio (aspect ratio) of the display device of one embodiment of the present invention is not particularly limited. For example, the display device can support various screen ratios, such as 1:1 (square), 4:3, 16:9, and 16:10.

[0481] The electronic device of this embodiment may have a sensor (including a function to measure force, displacement, position, velocity, acceleration, angular velocity, rotation speed, distance, light, liquid, magnetism, temperature, chemical substance, sound, time, hardness, electric field, current, voltage, power, radiation, flow rate, humidity, gradient, vibration, odor, or infrared rays).

[0482] The electronic device of the present embodiment can have various functions, such as a function to display various information (still images, videos, text images, etc.) on a display unit, a touch panel function, a function to display a calendar, date, time, etc., a function to execute various software (programs), a wireless communication function, a function to read out programs or data recorded on a recording medium, etc.

[0483] 24A to 24D , examples of wearable devices that can be worn on the head will be described. These wearable devices have one or both of a function to display AR content and a function to display VR content. Note that these wearable devices may also have a function to display SR or MR content in addition to AR and VR. By having an electronic device have the function to display content such as AR, VR, SR, and MR, it is possible to enhance the user's sense of immersion.

[0484] The electronic device 700A shown in FIG. 24A and the electronic device 700B shown in FIG. 24B each have a pair of display panels 751, a pair of housings 721, a communication unit (not shown), a pair of mounting units 723, a control unit (not shown), an imaging unit (not shown), a pair of optical members 753, a frame 757, and a pair of nose pads 758.

[0485] The display device of one embodiment of the present invention can be applied to the display panel 751. Therefore, the electronic device can provide an extremely high-definition display.

[0486] The electronic device 700A and the electronic device 700B can each project an image displayed on the display panel 751 onto a display area 756 of the optical member 753. Because the optical member 753 is translucent, the user can see the image displayed in the display area superimposed on a transmitted image visually recognized through the optical member 753. Therefore, the electronic device 700A and the electronic device 700B are each electronic devices capable of AR display.

[0487] Electronic device 700A and electronic device 700B may be provided with a camera capable of capturing an image in front of them as an imaging unit. Furthermore, electronic device 700A and electronic device 700B may each be provided with an acceleration sensor such as a gyro sensor, thereby detecting the orientation of the user's head and displaying an image corresponding to that orientation in display area 756.

[0488] The communication unit has a wireless communication device, and can supply a video signal, etc. Instead of or in addition to the wireless communication device, a connector to which a cable through which a video signal and a power supply potential are supplied may be provided.

[0489] Furthermore, the electronic device 700A and the electronic device 700B are provided with batteries, which can be charged wirelessly and / or by wire.

[0490] The housing 721 may be provided with a touch sensor module. The touch sensor module has a function of detecting a touch on the outer surface of the housing 721. The touch sensor module can detect a tap operation or a slide operation by the user and perform various processes. For example, a tap operation can perform a process such as pausing or resuming a video, and a slide operation can perform a process such as fast-forwarding or fast-rewinding. Furthermore, providing a touch sensor module on each of the two housings 721 can expand the range of operations.

[0491] Various touch sensors can be used as the touch sensor module. For example, various types of touch sensors can be used, such as a capacitance type, a resistive film type, an infrared type, an electromagnetic induction type, a surface acoustic wave type, and an optical type. In particular, it is preferable to use a capacitance type or an optical type sensor in the touch sensor module.

[0492] When an optical touch sensor is used, a photoelectric conversion device (also called a photoelectric conversion element) can be used as the light receiving device (also called a light receiving element). The active layer of the photoelectric conversion device can be made of either or both of an inorganic semiconductor and an organic semiconductor.

[0493] The electronic device 800A shown in Figure 24C and the electronic device 800B shown in Figure 24D each have a pair of display units 820, a housing 821, a communication unit 822, a pair of mounting units 823, a control unit 824, a pair of imaging units 825, and a pair of lenses 832.

[0494] The display device of one embodiment of the present invention can be applied to the display portion 820. Therefore, an electronic device capable of displaying images with extremely high definition can be provided. This allows a user to feel a high sense of immersion.

[0495] The display unit 820 is provided inside the housing 821 at a position that can be viewed through the lens 832. In addition, by displaying different images on the pair of display units 820, it is possible to perform three-dimensional display using parallax.

[0496] The electronic device 800A and the electronic device 800B can be said to be electronic devices for VR. A user wearing the electronic device 800A or the electronic device 800B can view an image displayed on the display unit 820 through the lens 832.

[0497] It is preferable that electronic device 800A and electronic device 800B each have a mechanism that can adjust the left and right positions of lens 832 and display unit 820 so that they are optimally positioned according to the position of the user's eyes. It is also preferable that electronic device 800A and electronic device 800B each have a mechanism that can adjust the focus by changing the distance between lens 832 and display unit 820.

[0498] The mounting unit 823 allows the user to mount the electronic device 800A or the electronic device 800B on the head. Note that, in Fig. 24C and other figures, the mounting unit 823 is shaped like the temples of glasses (also called joints or temples), but is not limited to this. The mounting unit 823 may be shaped like a helmet or a band, for example, as long as it can be worn by the user.

[0499] The imaging unit 825 has a function of acquiring external information. Data acquired by the imaging unit 825 can be output to the display unit 820. An image sensor can be used for the imaging unit 825. Furthermore, multiple cameras may be provided to support multiple angles of view, such as telephoto and wide-angle.

[0500] Although an example including the imaging unit 825 is shown here, a distance measuring sensor (hereinafter also referred to as a detection unit) capable of measuring the distance to an object may be provided. That is, the imaging unit 825 is one aspect of the detection unit. As the detection unit, for example, an image sensor or a range image sensor such as a LIDAR (Light Detection and Ranging) can be used. By using an image obtained by the camera and an image obtained by the range image sensor, more information can be obtained, enabling more accurate gesture operations.

[0501] The electronic device 800A may have a vibration mechanism that functions as a bone conduction earphone. For example, a configuration having such a vibration mechanism can be applied to one or more of the display unit 820, the housing 821, and the wearing unit 823. This allows a user to enjoy video and audio simply by wearing the electronic device 800A, without the need for separate audio equipment such as headphones, earphones, or speakers.

[0502] The electronic device 800A and the electronic device 800B may each have an input terminal to which a cable can be connected for supplying a video signal from a video output device or the like and power for charging a battery provided in the electronic device.

[0503] The electronic device of one embodiment of the present invention may have a function of wireless communication with an earphone 750. The earphone 750 includes a communication unit (not shown) and has a wireless communication function. The earphone 750 can receive information (e.g., audio data) from the electronic device through the wireless communication function. For example, an electronic device 700A shown in FIG. 24A has a function of transmitting information to the earphone 750 through the wireless communication function. Furthermore, for example, an electronic device 800A shown in FIG. 24C has a function of transmitting information to the earphone 750 through the wireless communication function.

[0504] The electronic device may also have an earphone unit. Electronic device 700B shown in Fig. 24B has earphone unit 727. For example, earphone unit 727 and the control unit may be configured to be connected to each other by wire. Part of the wiring connecting earphone unit 727 and the control unit may be disposed inside housing 721 or attachment unit 723.

[0505] Similarly, electronic device 800B shown in Fig. 24D has earphone unit 827. For example, earphone unit 827 and control unit 824 can be configured to be connected to each other by wire. Part of the wiring connecting earphone unit 827 and control unit 824 may be disposed inside housing 821 or wearing unit 823. Furthermore, earphone unit 827 and wearing unit 823 may have magnets. This allows earphone unit 827 to be fixed to wearing unit 823 by magnetic force, which is preferable as it makes storage easier.

[0506] The electronic device may have an audio output terminal to which earphones or headphones can be connected. The electronic device may also have one or both of an audio input terminal and an audio input mechanism. For example, a sound collection device such as a microphone can be used as the audio input mechanism. By having the audio input mechanism, the electronic device may be endowed with the functionality of a so-called headset.

[0507] As described above, as electronic devices of one embodiment of the present invention, both glasses-type devices (such as the electronic devices 700A and 700B) and goggle-type devices (such as the electronic devices 800A and 800B) are suitable.

[0508] Furthermore, the electronic device of one embodiment of the present invention can transmit information to the earphone by wire or wirelessly.

[0509] The electronic device 6500 shown in FIG. 25A is a portable information terminal that can be used as a smartphone.

[0510] 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.

[0511] The display device of one embodiment of the present invention can be applied to the display portion 6502 .

[0512] FIG. 25B is a schematic cross-sectional view including the end of the housing 6501 on the microphone 6506 side.

[0513] A light-transmitting protective member 6510 is provided on the display surface side of the housing 6501, and a display panel 6511, optical members 6512, a touch sensor panel 6513, a printed circuit board 6517, a battery 6518, etc. are arranged in the space surrounded by the housing 6501 and the protective member 6510.

[0514] A display panel 6511, an optical member 6512, and a touch sensor panel 6513 are fixed to the protective member 6510 by adhesive layers (not shown).

[0515] In a region outside the display portion 6502, a part of the display panel 6511 is folded back, and an FPC 6515 is connected to the folded back part. An IC 6516 is mounted on the FPC 6515. The FPC 6515 is connected to a terminal provided on a printed circuit board 6517.

[0516] The flexible display of one embodiment of the present invention can be applied to the display panel 6511. Therefore, an extremely lightweight electronic device can be realized. In addition, since the display panel 6511 is extremely thin, a large-capacity battery 6518 can be mounted thereon while keeping the thickness of the electronic device small. Furthermore, by folding back a part of the display panel 6511 and arranging a connection portion with the FPC 6515 on the back side of the pixel portion, an electronic device with a narrow frame can be realized.

[0517] 25C shows an example of a television set. A television set 7100 has a display portion 7000 built into a housing 7101. Here, the housing 7101 is supported by a stand 7103.

[0518] The display device of one embodiment of the present invention can be applied to the display portion 7000 .

[0519] 25C can be operated using operation switches provided on the housing 7101 and a separate remote control 7111. Alternatively, the display portion 7000 may be provided with a touch sensor, and the television set 7100 may be operated by touching the display portion 7000 with a finger or the like. The remote control 7111 may have a display portion that displays information output from the remote control 7111. Using operation keys or a touch panel provided on the remote control 7111, the channel and volume can be controlled, and an image displayed on the display portion 7000 can be controlled.

[0520] The television device 7100 is configured to include a receiver, a modem, and the like. Ordinary television broadcasts can be received using the receiver. Furthermore, by connecting to a wired or wireless communication network via the modem, it is possible to perform one-way (from a sender to a receiver) or two-way (between a sender and a receiver, or between receivers, etc.) information communication.

[0521] 25D shows an example of a laptop personal computer 7200. The laptop personal computer 7200 includes a housing 7211, a keyboard 7212, a pointing device 7213, and an external connection port 7214. The housing 7211 includes a display portion 7000.

[0522] The display device of one embodiment of the present invention can be applied to the display portion 7000 .

[0523] 25E and 25F show an example of digital signage.

[0524] 25E includes a housing 7301, a display portion 7000, and a speaker 7303. The digital signage 7300 may further include an LED lamp, operation keys (including a power switch or an operation switch), a connection terminal, various sensors, a microphone, and the like.

[0525] 25F shows a digital signage 7400 attached to a cylindrical pillar 7401. The digital signage 7400 has a display unit 7000 provided along the curved surface of the pillar 7401.

[0526] 25E and 25F, the display device of one embodiment of the present invention can be applied to the display portion 7000.

[0527] The larger the display unit 7000, the more information can be provided at one time. Also, the larger the display unit 7000, the more easily it will attract people's attention, which can increase the advertising effectiveness of, for example, advertisements.

[0528] Applying a touch panel to the display unit 7000 is preferable because it not only displays images or videos on the display unit 7000 but also allows the user to intuitively operate it. Furthermore, when used to provide information such as route information or traffic information, the intuitive operation can improve usability.

[0529] 25E and 25F , the digital signage 7300 or the digital signage 7400 is preferably capable of wirelessly linking with an information terminal 7311 or an information terminal 7411 such as a smartphone carried by a user. For example, advertising information displayed on the display unit 7000 can be displayed on the screen of the information terminal 7311 or the information terminal 7411. By operating the information terminal 7311 or the information terminal 7411, the display on the display unit 7000 can be switched.

[0530] Furthermore, the digital signage 7300 or the digital signage 7400 can be made to run a game using the screen of the information terminal 7311 or the information terminal 7411 as an operation means (controller), thereby allowing an unspecified number of users to simultaneously participate in and enjoy the game.

[0531] The electronic device shown in Figures 26A to 26G has a housing 9000, a display unit 9001, a speaker 9003, operation keys 9005 (including a power switch or an operation switch), a connection terminal 9006, a sensor 9007 (including a function to measure force, displacement, position, speed, acceleration, angular velocity, rotation speed, distance, light, liquid, magnetism, temperature, chemical substance, sound, time, hardness, electric field, current, voltage, power, radiation, flow rate, humidity, gradient, vibration, odor or infrared rays), a microphone 9008, etc.

[0532] 26A to 26G, the display device of one embodiment of the present invention can be applied to the display portion 9001.

[0533] The electronic devices shown in Figures 26A to 26G have various functions. For example, they may have a function to display various information (still images, videos, text images, etc.) on a display unit, a touch panel function, a function to display a calendar, date, or time, a function to control processing using various software (programs), a wireless communication function, a function to read and process programs or data recorded on a recording medium, etc. Note that the functions of the electronic devices are not limited to these, and they may have various other functions. The electronic devices may have multiple display units. Furthermore, the electronic devices may have a function to include a camera or the like to capture still images or videos and store them on a recording medium (external or built-in to the camera), a function to display the captured images on the display unit, etc.

[0534] The electronic devices shown in FIGS. 26A to 26G will be described in detail below.

[0535] FIG. 26A is a perspective view showing a mobile information terminal 9101. The mobile information terminal 9101 can be used as, for example, a smartphone. Note that the mobile information terminal 9101 may be provided with a speaker 9003, a connection terminal 9006, a sensor 9007, and the like. The mobile information terminal 9101 can display text and image information on multiple surfaces. FIG. 26A shows an example in which three icons 9050 are displayed. Information 9051, indicated by a dashed rectangle, can also be displayed on another surface of the display unit 9001. Examples of the information 9051 include notifications of incoming emails, SNS messages, phone calls, etc., the title of the email or SNS message, the sender's name, the date and time, the remaining battery level, and radio wave intensity. Alternatively, an icon 9050 or the like may be displayed in the position where the information 9051 is displayed.

[0536] 26B is a perspective view showing the mobile information terminal 9102. The mobile information terminal 9102 has a function of displaying information on three or more surfaces of the display unit 9001. Here, an example is shown in which information 9052, information 9053, and information 9054 are displayed on different surfaces. For example, a user can check information 9053 displayed in a position that can be observed from above the mobile information terminal 9102 while the mobile information terminal 9102 is placed in a breast pocket of clothes. The user can check the display without taking the mobile information terminal 9102 out of the pocket and decide, for example, whether to answer a call.

[0537] 26C is a perspective view showing a tablet terminal 9103. The tablet terminal 9103 is capable of executing various applications such as mobile phone calls, e-mail, text browsing and creation, music playback, internet communication, and computer games, for example. The tablet terminal 9103 has a display unit 9001, a camera 9002, a microphone 9008, and a speaker 9003 on the front side of a housing 9000, operation keys 9005 as operation buttons on the left side of the housing 9000, and a connection terminal 9006 on the bottom.

[0538] FIG. 26D is a perspective view showing a wristwatch-type mobile information terminal 9200. The mobile information terminal 9200 can be used as, for example, a smart watch (registered trademark). The display surface of the display unit 9001 is curved, and display can be performed along the curved display surface. The mobile information terminal 9200 can also perform hands-free calling by communicating with, for example, a headset capable of wireless communication. The mobile information terminal 9200 can also perform data transmission and charging with another information terminal through a connection terminal 9006. Note that charging may be performed by wireless power supply.

[0539] 26E to 26G are perspective views showing a foldable mobile information terminal 9201. Also, FIG. 26E is a perspective view of the mobile information terminal 9201 in an unfolded state, FIG. 26G is a perspective view of the mobile information terminal 9201 in a folded state, and FIG. 26F is a perspective view of a state in the process of changing from one of FIGS. 26E and 26G to the other. The mobile information terminal 9201 is highly portable when folded, and has a seamless, wide display area when unfolded, providing excellent visibility of the display. The display portion 9001 of the mobile information terminal 9201 is supported by three housings 9000 connected by hinges 9055. For example, the display portion 9001 can be bent with a curvature radius of 0.1 mm or more and 150 mm or less.

[0540] 27A includes a housing 2801, a housing 2802, a display portion 2803, a keyboard 2804, a pointing device 2805, and the like. A secondary battery 2807 is provided inside the housing 2801, and a secondary battery 2806 is provided inside the housing 2802. The display device of one embodiment of the present invention is applied to the display portion 2803, and the display portion 2803 has a touch panel function. As shown in FIG. 27B, the housings 2801 and 2802 can be removed from the personal computer 2800, and the personal computer 2800 can be used as a tablet terminal using only the housing 2802.

[0541] In a modification of the personal computer shown in Fig. 27C, a flexible display is applied to the display portion 2803. The secondary battery 2806 can be made bendable by using a flexible film for the exterior body. This allows the housing 2802, the display portion 2803, and the secondary battery 2806 to be folded and used as shown in Fig. 27C. In this case, part of the display portion 2803 can also be used as a keyboard as shown in Fig. 27C.

[0542] The housing 2802 can be folded so that the display portion 2803 faces inward as shown in FIG. 27D, or can be folded so that the display portion 2803 faces outward as shown in FIG. 27E.

[0543] FIG. 27F is a perspective view showing a steering wheel of a vehicle. The steering wheel 41 includes a rim 42, a hub 43, spokes 44, a shaft 45, and the like. A display unit 20 is provided on the surface of the hub 43. The display device of one embodiment of the present invention can be applied to the display unit 20. Of the three spokes 44, the lower spoke 44 is provided with a light-emitting and receiving unit 20b, the left spoke 44 is provided with multiple light-emitting and receiving units 20c, and the right spoke 44 is provided with multiple light-emitting and receiving units 20d. By holding the fingers of a hand 35 over the light-emitting and receiving unit 20b, the driver's fingerprint information can be acquired and authentication can be performed using the acquired information. Furthermore, by touching the light-emitting and receiving units 20c and 20d, the navigation system, audio system, communication system, and the like of the vehicle can be operated. Furthermore, various operations can be performed, such as adjusting the rearview mirror, adjusting the side mirrors, turning on / off and adjusting the brightness of the interior lights, and opening and closing the windows.

[0544] This embodiment mode can be combined with other embodiment modes as appropriate.

[0545] In this example, the results of a comparison between display at low luminance and display at high luminance on a display device are shown.

[0546] In this example, four display devices, namely, a display device A, a display device B, a display device C, and a display device D, were prepared.

[0547] Display device A has a display section (also called a display area) with a diagonal size of 0.95 inches, a resolution of 3078 ppi, and a pixel arrangement of three RGB color stripes (see Figure 1A), and is configured by combining a tandem light-emitting device with a color filter. Display device A also has measures to prevent crosstalk, specifically, the pixel electrodes are formed to a thickness of 258 nm.

[0548] Display device B has a display area with a diagonal of 0.7 inches, a resolution of 3256 ppi, and a pixel arrangement of three colors of RGB in a delta arrangement (see Figures 9D and 9E), and is configured by combining a single-structure light-emitting device with a color filter.

[0549] Display device C has a display area of ​​0.43 inches diagonally, a resolution of 3256 ppi, and a pixel arrangement of three RGB color stripes, and is configured by combining a single-structure light-emitting device with a color filter.

[0550] Display device D has a display area diagonal of 0.99 inches, a resolution of 2731 ppi, and a pixel arrangement in a three-color stripe arrangement of RGB, and uses light-emitting devices with an SBS structure. That is, a separate light-emitting device is fabricated for each emitted color, with a light-emitting device having a blue light-emitting layer for the sub-pixel that emits blue light, a light-emitting device having a green light-emitting layer for the sub-pixel that emits green light, and a light-emitting device having a red light-emitting layer for the sub-pixel that emits red light. Display device D also incorporates measures to prevent crosstalk; specifically, portions of the EL layer are processed into island shapes by photolithography.

[0551] Each display device was used to display red (R), green (G), and blue (B), and the chromaticity and emission spectrum were measured using a spectroradiometer (SR-LEDW-5N manufactured by Topcon Technohouse Co., Ltd.). The emission spectrum when black (BK) was displayed on each display device was also measured. Each color was displayed under two conditions: high brightness and low brightness.

[0552] The high brightness condition is a brightness of 100 cd / m ２The values ​​of the luminance of red, green, and blue when white is displayed at 0 cd / m ２ Higher than 100 cd / m ２ Values ​​below 0.01 resulted in a monochrome display of red, green, or blue.

[0553] The low brightness condition is a brightness of 1 cd / m ２ The values ​​of the luminance of red, green, and blue when white is displayed at 0 cd / m ２ Higher than 1cd / m ２ Values ​​below 0.01 resulted in a monochrome display of red, green, or blue.

[0554] FIG. 28A shows the brightness of the display device A under high brightness conditions (A_100 cd / m ２ ) and low luminance conditions (A_1 cd / m ２ ) indicates the chromaticity.

[0555] FIG. 28B shows the results of the high luminance condition (B_100 cd / m ２ ) and low luminance conditions (B_1 cd / m ２ ) indicates the chromaticity.

[0556] FIG. 28C shows the results of the high luminance condition (C_100 cd / m ２ ) and low luminance conditions (C_1 cd / m ２ ) indicates the chromaticity.

[0557] FIG. 32 shows the high luminance condition (D_100 cd / m ２ ) and low luminance conditions (D_1 cd / m ２ ) indicates the chromaticity.

[0558] 28A to 28C and 32 also plot and show the color gamut of the DCI-P3 (Digital Cinema Initiatives P3) standard.

[0559] 28A , in display device A, almost no change in chromaticity was observed between the two conditions when displaying any of the single colors red, green, and blue. The DCI-P3 coverage rate of display device A was 88.1% under the high brightness condition and 86.1% under the low brightness condition, showing almost no change, and it was found that the color purity was extremely high regardless of the brightness.

[0560] As shown in Figure 28B, in Display Device B, the chromaticity shifted toward red under low brightness conditions. This suggests that crosstalk is not occurring in Display Device B (unintended light-emitting devices are emitting light), but rather that the light-emitting color of the light-emitting device that should be emitting light may have shifted toward red. It was found that the DCI-P3 coverage rate in Display Device B was 69.0% under high brightness conditions, but significantly decreased to 22.6% under low brightness conditions.

[0561] As shown in Figure 28C, display device C exhibited a shift in chromaticity toward yellow under low brightness conditions. Display device C exhibited changes in chromaticity across all RGB colors, suggesting crosstalk. Furthermore, the change was particularly pronounced in blue monochromatic display, suggesting the possibility of a change in the emitted color of a light-emitting device intended to emit blue. It was found that the DCI-P3 coverage rate for display device C was 88.3% under high brightness conditions, but significantly decreased to 8.9% under low brightness conditions.

[0562] 32 , in display device D, almost no change in chromaticity was observed between the two conditions when displaying any of the single colors red, green, and blue. The DCI-P3 coverage rate of display device D was 99.7% under the high brightness condition and 99.3% under the low brightness condition, with almost no change, and it was found that the color purity was extremely high regardless of the brightness.

[0563] 29A and 29B show the spectral radiance (unit: W / sr / m) of the display device A. ２ 29A shows the wavelength dependence of the emission spectrum under high luminance conditions, and FIG. 29B shows the emission spectrum under low luminance conditions.

[0564] 30A and 30B show the spectral radiance (unit: W / sr / m) of display device B. ２ 30A shows the emission spectrum under high luminance conditions, and FIG. 30B shows the emission spectrum under low luminance conditions.

[0565] 31A and 31B show the spectral radiance (unit: W / sr / m) of the display device C. ２ 31A shows the wavelength dependence of the emission spectrum under high luminance conditions, and FIG. 31B shows the emission spectrum under low luminance conditions.

[0566] 33A and 33B show the spectral radiance (unit: W / sr / m) of the display device D. ２ 33A shows the wavelength dependence of the emission spectrum under high luminance conditions, and FIG. 33B shows the emission spectrum under low luminance conditions.

[0567] As shown in Figures 29A and 29B, it was found that display device A did not exhibit color mixing under either high or low brightness conditions. Specifically, it was found that when red (R) was displayed in display device A, only the light-emitting device in the red sub-pixel emitted light, and red light was extracted, even under low brightness conditions. Similarly, when green (G) was displayed under low brightness conditions, only the light-emitting device in the green sub-pixel emitted light, and green light was extracted. Furthermore, when blue (B) was displayed under low brightness conditions, only the light-emitting device in the blue sub-pixel emitted light, and blue light was extracted. Furthermore, when black (BK) was displayed, almost no light emission was observed under either high or low brightness conditions.

[0568] Display device A uses a tandem-structure light-emitting device and is equipped with measures to prevent crosstalk. Therefore, even when the brightness is changed, there is very little change in the display color, and it was found that the crosstalk phenomenon was also suppressed. Display device A has an extremely high resolution of 3000 ppi or more, but no crosstalk was observed, and it was found that extremely high display quality was obtained.

[0569] The display device A can be said to have a configuration in which, when the display unit displays blue at a first luminance, the intensity of a first emission peak at a wavelength of 400 nm or more and less than 500 nm in the emission spectrum is set to 1, the intensity of a second emission peak at a wavelength of 500 nm or more and 700 nm or less in the emission spectrum is set to 0.5 or less. Here, the first luminance is 0 cd / m ２ Higher than 1cd / m ２ is one of the values ​​less than

[0570] As shown in Figure 30A, it was suggested that the light-emitting device of Display Device B was designed to achieve RGB color balance under high brightness conditions. On the other hand, as shown in Figure 30B, it was found that Display Device B emitted strong red light under low brightness conditions. This suggests that a change in chromaticity occurs between low and high brightness.

[0571] Specifically, in display device B, when red (R) display was performed under low luminance conditions, mainly red light emission was observed. Furthermore, when green (G) display was performed under low luminance conditions, not only green light emission but also red light emission was observed, indicating the occurrence of color mixing. As shown in FIG. 28B, the chromaticity changed from green (G) to red (R). Furthermore, when blue (B) display was performed under low luminance conditions, not only blue light emission but also red light emission was observed, indicating the occurrence of color mixing. As shown in FIG. 28B, the chromaticity changed from blue (B) to red (R). Furthermore, when black (BK) display was performed under low luminance conditions, red light emission was also observed.

[0572] Display device B uses a single-structure light-emitting device having a red light-emitting layer, a green light-emitting layer, and a blue light-emitting layer. It is thought that because it is difficult to adjust the carrier balance in a single structure having multiple light-emitting layers, the carrier balance is disrupted under low-luminance conditions, making it easier for the light-emitting device to emit red light.

[0573] As shown in Figure 31A, it was found that no color mixing was observed under high luminance conditions in Display Device C. On the other hand, as shown in Figure 31B, it was found that color mixing occurred under low luminance conditions in Display Device C. This suggests that a change in chromaticity occurs between low and high luminance.

[0574] Specifically, when display device C displayed red (R) under low luminance conditions, not only red but also green light was observed, indicating that color mixing had occurred. As shown in FIG. 28C , the chromaticity changed from red (R) toward yellow. Furthermore, when display device C displayed green (G) under low luminance conditions, not only green but also red light was observed, indicating that color mixing had occurred. As shown in FIG. 28C , the chromaticity changed from green (G) toward yellow. Furthermore, when display device C displayed blue (B) under low luminance conditions, not only blue but also green and red light was observed, indicating that color mixing had occurred. As shown in FIG. 28C , the chromaticity changed from blue (B) toward yellow.

[0575] Display device C uses a single-structure light-emitting device having a red light-emitting layer, a green light-emitting layer, and a blue light-emitting layer. Because it is difficult to adjust the carrier balance in a single structure having multiple light-emitting layers, it is believed that the carrier balance is disrupted under low-luminance conditions, making the light-emitting device more likely to emit red and green light. Furthermore, crosstalk occurs in display device C, which is thought to be the cause of changes in chromaticity between low and high luminance.

[0576] As shown in Figures 33A and 33B, it was found that display device D did not exhibit color mixing under either high or low brightness conditions. Specifically, it was found that when red (R) was displayed in display device D, only the light-emitting device in the red sub-pixel emitted light, and red light was extracted, even under low brightness conditions. Similarly, when green (G) was displayed under low brightness conditions, only the light-emitting device in the green sub-pixel emitted light, and green light was extracted. Furthermore, when blue (B) was displayed under low brightness conditions, only the light-emitting device in the blue sub-pixel emitted light, and blue light was extracted. Furthermore, when black (BK) was displayed, almost no light emission was observed under either high or low brightness conditions.

[0577] In display device D, a separate light-emitting device is created for each emitted color, and measures to prevent crosstalk are taken. Therefore, even when the brightness is changed, there is very little change in the displayed color, and it was found that the crosstalk phenomenon has been suppressed. Despite the extremely high resolution of display device D, no crosstalk was observed, and it was found that extremely high display quality was obtained.

[0578] As described above, it has been suggested that the use of a tandem structure facilitates carrier balance adjustment even in a light-emitting device having multiple light-emitting layers, thereby suppressing color change over a wide luminance range. Furthermore, it has been suggested that color change over a wide luminance range can be suppressed by taking measures against crosstalk. In a display device according to one embodiment of the present invention, at least a portion of the EL layer of a light-emitting device having a tandem structure is formed in an island shape. This facilitates carrier balance adjustment and suppresses crosstalk. Therefore, color change over a wide luminance range can be suppressed.

[0579] 20b: light-emitting / receiving unit, 20c: light-emitting / receiving unit, 20d: light-emitting / receiving unit, 20: display unit, 35: hand, 41: handle, 42: rim, 43: hub, 44: spokes, 45: shaft, 100A: display device, 100B: display device, 100C: display device, 100D: display device, 100E: display device, 100F: display device, 100G: display device, 100H: display device, 100: display device, 101: layer including transistor, 103: pixel, 110a: sub-pixel, 110B: sub-pixel, 110b: sub-pixel, 110c: sub-pixel, 110d: sub-pixel, 110G: sub-pixel, 110R ... 10: pixel, 111a: pixel electrode, 111b: pixel electrode, 111: pixel electrode, 113A: EL layer, 113a: first light-emitting unit, 113b: charge generation layer, 113c: second light-emitting unit, 113: EL layer, 114: common layer, 115: common electrode, 117: light-shielding layer, 118A: sacrificial layer, 118: sacrificial layer, 119A: sacrificial layer, 119: sacrificial layer, 120: substrate, 122: resin layer, 123: conductive layer, 124a: pixel, 124b: pixel, 125a: insulating layer, 125A: insulating film, 125b: insulating layer, 125: insulating layer, 126: conductive layer, 127a: insulating layer, 127A: insulating film, 127b: insulating layer, 127: insulating layer, 128: layer, 129: conductive layer, 130: light-emitting device, 131: protective layer, 132B: colored layer, 132G: colored layer, 132R: colored layer, 133: lens array, 134: insulating layer, 138: region, 139: region, 140: connecting portion, 142: adhesive layer, 151: substrate, 152: substrate, 153: insulating layer, 162: display portion, 164: circuit, 165: wiring, 166: conductive layer, 172a: FPC, 172b: FPC, 172: FPC, 173: IC, 190: resist mask, 191: mask, 201: transistor, 204: connection part, 205: transistor, 209: transistor, 210: transistor, 211: insulating layer, 213: insulating layer, 214: insulating layer, 215: insulating layer, 218: insulating layer, 221: conductive layer, 222a: conductive layer, 222b: conductive layer, 223: conductive layer, 225: insulating layer, 231i: channel formation region, 231n: low resistance region, 231: semiconductor layer, 240: capacitor, 241: conductive layer, 242a: connection layer, 242b: connection layer, 242: connection layer, 243: insulating layer, 245: conductive layer, 251: conductive layer, 252: conductive layer, 254: insulating layer, 255a: insulating layer, 255b: insulating layer,255: insulating layer, 256: plug, 261: insulating layer, 262: insulating layer, 263: insulating layer, 264: insulating layer, 265: insulating layer, 271: plug, 274a: conductive layer, 274b: conductive layer, 274: plug, 280: display module, 281: display section, 282: circuit section, 283a: pixel circuit, 283: pixel circuit section, 284a: pixel, 284: pixel section, 285: terminal section, 286: wiring section, 290: FPC, 291: substrate, 292: substrate, 301A: substrate, 301B: substrate, 301: substrate, 310A: transistor, 310B: transistor, 310: transistor 311: conductive layer, 312: low resistance region, 313: insulating layer, 314: insulating layer, 315: element isolation layer, 320a: transistor, 320b: transistor, 320: transistor, 321: semiconductor layer, 323: insulating layer, 324: conductive layer, 325: conductive layer, 326: insulating layer, 327: conductive layer, 328: insulating layer, 329: insulating layer, 331: substrate, 332: insulating layer, 335: insulating layer, 336: insulating layer, 341: conductive layer, 342: conductive layer, 343: plug, 344: insulating layer, 345: insulating layer, 346: insulating layer, 347: bump, 348: adhesive layer, 351a: conductive layer, 351b: conductive layer, 353a: sacrificial layer, 353b: sacrificial layer, 354: insulating layer, 355a: wiring, 355b: wiring, 361: sealing material, 700A: electronic device, 700B: electronic device, 721: housing, 723: wearing portion, 727: earphone portion, 750: earphone, 751: display panel, 753: optical member, 756: display area, 757: frame, 758: nose pad, 772: lower electrode, 785: layer, 786a: EL layer, 786b: EL layer, 786: EL layer, 788: upper electrode, 800A: electronic device, 800B: electronic device, 820: display portion, 821: housing , 822: communication unit, 823: wearing unit, 824: control unit, 825: imaging unit, 827: earphone unit, 832: lens, 2800: personal computer, 2801: housing, 2802: housing, 2803: display unit, 2804: keyboard, 2805: pointing device, 2806: secondary battery, 2807: secondary battery, 4411: light-emitting layer, 4412: light-emitting layer, 4413: light-emitting layer, 4420: layer, 4421: layer, 4422: layer, 4430: layer, 4431: layer, 4432: layer, 4440: charge generation layer, 6500: electronic device, 6501: housing, 6502: display unit,6503: power button, 6504: button, 6505: speaker, 6506: microphone, 6507: camera, 6508: light source, 6510: protective member, 6511: display panel, 6512: optical member, 6513: touch sensor panel, 6515: FPC, 6516: IC, 6517: printed circuit board, 6518: battery, 7000: display unit, 7100: television device, 7101: housing, 7103: stand, 7111: remote control device, 7200: notebook personal computer, 7211: housing, 7212: keyboard, 7213: pointing device, 7214: external connection port, 7 300: Digital signage, 7301: Housing, 7303: Speaker, 7311: Information terminal, 7400: Digital signage, 7401: Pillar, 7411: Information terminal, 9000: Housing, 9001: Display unit, 9002: Camera, 9003: Speaker, 9005: Operation keys, 9006: Connection terminal, 9007: Sensor, 9008: Microphone, 9050: Icon, 9051: Information, 9052: Information, 9053: Information, 9054: Information, 9055: Hinge, 9101: Portable information terminal, 9102: Portable information terminal, 9103: Tablet terminal, 9200: Portable information terminal, 9201: Portable information terminal,

Claims

1. A display unit capable of full color display is provided. the display unit includes a first sub-pixel and a second sub-pixel; the first subpixel includes a first light emitting device and a first colored layer that transmits blue light; the first light emitting device has a first pixel electrode, a first electroluminescent layer on the first pixel electrode, and a common electrode on the first electroluminescent layer; the first EL layer includes a first light-emitting material that emits blue light and a second light-emitting material that emits light having a wavelength longer than blue; the first EL layer has a first light-emitting unit on the first pixel electrode, a charge generating layer on the first light-emitting unit, and a second light-emitting unit on the charge generating layer; the second subpixel includes a second light emitting device and a second colored layer that transmits light of a different color than the first colored layer; the second light emitting device has a second pixel electrode, a second electroluminescent layer on the second pixel electrode, and the common electrode on the second electroluminescent layer; the first EL layer and the second EL layer have the same configuration; the first EL layer and the second EL layer are separated from each other; when the display unit displays blue at a first luminance, the intensity of a first emission peak having a wavelength of 400 nm or more and less than 500 nm in an emission spectrum is taken as 1, the intensity of a second emission peak having a wavelength of 500 nm or more and 700 nm or less in the emission spectrum is 0.5 or less, The first luminance is 0 cd / m ２ Higher than 1cd / m ２ A display device that is either

2. In claim 1, the display unit includes a first insulating layer having an inorganic material and a second insulating layer having an organic material; the first insulating layer has a region covering a side surface of the first EL layer and a region covering a side surface of the second EL layer, the first insulating layer has a region in contact with a side surface of the first pixel electrode and a region in contact with a side surface of the second pixel electrode, the second insulating layer has a region covering a side surface of the first EL layer and a region covering a side surface of the second EL layer via the first insulating layer, The common electrode is located on the first insulating layer.

3. A display unit capable of full color display is provided. the display unit includes a first subpixel, a second subpixel, a first insulating layer including an inorganic material, and a second insulating layer including an organic material; the first subpixel includes a first light emitting device and a first colored layer that transmits blue light; the second subpixel includes a second light emitting device and a second colored layer that transmits light of a different color than the first colored layer; the first light emitting device has a first pixel electrode, a first electroluminescent layer on the first pixel electrode, and a common electrode on the first electroluminescent layer; the second light emitting device has a second pixel electrode, a second EL layer on the second pixel electrode, and the common electrode on the second EL layer, the first EL layer and the second EL layer having the same configuration; the first EL layer and the second EL layer are separated from each other; the first EL layer has a first light-emitting unit on the first pixel electrode, a charge generating layer on the first light-emitting unit, and a second light-emitting unit on the charge generating layer; the first insulating layer has a region covering a side surface of the first EL layer and a region covering a side surface of the second EL layer, the first insulating layer has a region in contact with a side surface of the first pixel electrode and a region in contact with a side surface of the second pixel electrode, the second insulating layer has a region covering a side surface of the first EL layer and a region covering a side surface of the second EL layer via the first insulating layer, the common electrode is located on the first insulating layer; when the display unit displays blue at a first luminance, the intensity of a first emission peak having a wavelength of 400 nm or more and less than 500 nm in an emission spectrum is taken as 1, the intensity of a second emission peak having a wavelength of 500 nm or more and 700 nm or less in the emission spectrum is 0.5 or less, The first luminance is 0 cd / m ２ Higher than 1cd / m ２ A display device that is either

4. In any one of claims 1 to 3, the first light emitting device has a common layer between the first EL layer and the common electrode; the second light emitting device has the common layer between the second EL layer and the common electrode; The display device, wherein the common layer has at least one of a hole injection layer, a hole transport layer, a hole blocking layer, an electron blocking layer, an electron transport layer, and an electron injection layer.

5. In any one of claims 1 to 4, A display device, wherein the resolution of the display unit is 1000 ppi or more.

6. In any one of claims 1 to 5, The first subpixel comprises a lens overlapping the first light emitting device and the first colored layer.

7. In any one of claims 1 to 6, The first pixel electrode comprises a material that reflects visible light.

8. In any one of claims 1 to 7, the first subpixel has a reflective layer; the first pixel electrode has a material that transmits visible light; The first pixel electrode is located between the reflective layer and the first EL layer.

9. A display device according to any one of claims 1 to 8, A display module having at least one of a connector and an integrated circuit.

10. A display module according to claim 9; An electronic device having at least one of a housing, a battery, a camera, a speaker, and a microphone.