Indication device

Abstract

The present invention provides a high-definition display device. This display device has a first light emitting device, a second light emitting device, a first insulating layer, a second insulating layer, a first colored layer, and a second colored layer. The first light emitting device has a first pixel electrode, a first layer, and a common electrode in this order on a first insulating layer. The second light emitting device has a second pixel electrode, a second layer, and the common electrode in this order on the first insulating layer. The first insulating layer has a groove having a region overlapping the first pixel electrode and a region overlapping the second pixel electrode, and the second insulating layer overlaps a side surface of the first layer, a side surface of the second layer, and the groove. The common electrode has a section positioned on the second insulating layer. The first colored layer overlaps with the first light emitting device. The second colored layer overlaps with the second light emitting device and transmits light of a different color than the first colored layer. The first layer and the second layer have mutually the same light emitting material and are separated from each other.

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). Furthermore, examples of portable information terminals include smartphones and tablet terminals equipped with touch panels.

[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] Wearable devices for VR, AR, SR, or MR have focus-adjusting lenses between the eyes and the display device. Because the lenses magnify a portion of the screen, if the resolution of the display device is low, the sense of reality and immersion can be diminished.

[0009] An object of one embodiment of the present invention is to provide a high-resolution display device.An 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 aspect of the present invention provides a light emitting device having a first light emitting device, a second light emitting device, a first insulating layer, a second insulating layer, a first colored layer, and a second colored layer, the first light emitting device having a first pixel electrode on the first insulating layer, a first layer on the first pixel electrode, and a common electrode on the first layer, the second light emitting device having a second pixel electrode on the first insulating layer, a second layer on the second pixel electrode, and a common electrode on the second layer, the first insulating layer having a groove, and the groove being a first pixel electrode. a region overlapping with the first electrode and a region overlapping with the second pixel electrode; a second insulating layer overlapping with a side surface of the first layer, a side surface of the second layer, and the groove; a common electrode having a portion located on the second insulating layer; a first colored layer overlapping with a first light-emitting device; a second colored layer overlapping with a second light-emitting device; the second colored layer transmitting light of a color different from that of the first colored layer; and the first layer and the second layer having the same light-emitting material and spaced apart from each other.

[0013] The display device may include a material layer located between a first insulating layer and a second insulating layer in the groove, the first layer, the second layer, and the material layer all having the same light-emitting material and spaced apart from one another.

[0014] The second insulating layer preferably includes an organic material and is provided so as to fill the grooves.

[0015] One embodiment of the present invention provides a light-emitting device including a first light-emitting device, a second light-emitting device, a first insulating layer, a second insulating layer, a first colored layer, and a second colored layer. The first light-emitting device includes a first pixel electrode on the first insulating layer, a first layer on the first pixel electrode, and a common electrode on the first layer. The second light-emitting device includes a second pixel electrode on the first insulating layer, a second layer on the second pixel electrode, and a common electrode on the second layer. The first insulating layer is a layer that is in contact with the first pixel electrode and the second pixel electrode when viewed from above. A display device having a first groove and a second groove in a region between the pixel electrodes, a second insulating layer overlapping a side surface of the first layer, a side surface of the second layer, the first groove, and the second groove, a common electrode having a portion located on the second insulating layer, a first colored layer overlapping a first light-emitting device, a second colored layer overlapping a second light-emitting device, the second colored layer transmitting light of a color different from that of the first colored layer, and the first layer and the second layer having the same light-emitting material and spaced apart from each other.

[0016] The display device may include a first material layer and a second material layer. In the first groove, the first material layer is located between the first insulating layer and the second insulating layer. In the second groove, the second material layer is located between the first insulating layer and the second insulating layer. The first layer, the second layer, the first material layer, and the second material layer all have the same light-emitting material and are spaced apart from each other.

[0017] The second insulating layer preferably includes an organic material and is provided so as to fill the first and second grooves.

[0018] Each of the first and second layers preferably contains a first light-emitting material that emits blue light and a second light-emitting material that emits light with a wavelength longer than that of blue light.

[0019] Alternatively, both the first light-emitting device and the second light-emitting device preferably emit blue light. In this case, the display device preferably has a color conversion layer. The color conversion layer is preferably located between the first light-emitting device and the first colored layer, and converts the blue light into first light having a longer wavelength. The first colored layer preferably transmits the first light, and the second colored layer preferably transmits the blue light.

[0020] The transmittance of the second insulating layer for light of one or more of red, green, and blue colors is preferably lower than the transmittance of the first insulating layer.

[0021] The first insulating layer preferably has a portion in contact with the first pixel electrode and a portion in contact with the second pixel electrode.

[0022] Another embodiment of the present invention is a display module including a display device having any of the above structures and to which a connector such as a flexible printed circuit (FPC) board or a tape carrier package (TCP) is attached.Another embodiment of the present invention is a display module including a display device having any of the above structures and on which an integrated circuit (IC) is mounted by a chip-on-glass (COG) method, a chip-on-film (COF) method, or the like.

[0023] Another embodiment of the present invention is an electronic device including the above-described display module and one or more of a housing, a battery, a camera, a speaker, and a microphone.

[0024] 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.

[0025] 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.

[0026] 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.

[0027] FIG. 1A is a top view showing an example of a display device. FIGS. 1B and 1C are cross-sectional views showing an example of a display device. FIGS. 2A and 2B are cross-sectional views showing an example of a display device. FIGS. 3A to 3D 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 and 6B are top views showing an example of a display device. FIG. 7A is a top view showing an example of a display device. FIGS. 7B and 7C are cross-sectional views showing an example of a display device. FIGS. 8A and 8B are top views showing an example of a display device. FIGS. 9A to 9C are cross-sectional views showing an example of a display device. FIGS. 10A and 10B are cross-sectional views showing an example of a display device. FIGS. 11A to 11C are cross-sectional views showing an example of a display device. FIGS. 12A and 12B are cross-sectional views showing an example of a display device. FIGS. 13A to 13C are cross-sectional views showing an example of a display device. FIGS. 14A to 14C are cross-sectional views showing an example of a display device. FIGS. 15A and 15B are cross-sectional views showing an example of a display device. FIGS. 16A to 16E are cross-sectional views showing an example of a method for manufacturing a display device. FIGS. 17A to 17G are views showing an example of a pixel. FIGS. 18A to 18I are views showing an example of a pixel. FIGS. 19A and 19B are perspective views 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. FIG. 23 is a cross-sectional view showing an example of a display device. FIG. 24 is a cross-sectional view showing an example of a display device. FIG. 25 is a cross-sectional view showing an example of a display device. FIGS. 26A to 26F are views showing a structural example of a light-emitting device. FIGS. 27A to 27C are views showing a structural example of a light-emitting device. FIGS. 28A to 28D are views showing an example of an electronic device. FIGS. 29A to 29F are views showing an example of an electronic device. FIGS. 30A to 30G are views showing an example of an electronic device.

[0028] 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.

[0029] 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.

[0030] 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.

[0031] In this specification, the ordinal numbers "first" and "second" are used for convenience and do not limit the number of components or the order of the components (for example, the order of processes or the order of stacking). Furthermore, the ordinal numbers assigned to components in one part of this specification may not match the ordinal numbers assigned to the same components in other parts of this specification or in the claims.

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

[0035] In this specification and the like, a light-emitting device (also referred to as a light-emitting element) has an EL layer between a pair of electrodes. The EL layer has at least a light-emitting layer. Here, examples of layers (also referred to as functional layers) included in the EL layer include a light-emitting layer, a hole injection layer, an electron injection layer, a hole transport layer, an electron transport layer, a hole blocking layer, and an electron blocking layer. In this specification and the like, one of the pair of electrodes may be referred to as a pixel electrode, and the other may be referred to as a common electrode.

[0036] In this specification, the term "island-like" refers to a state in which two or more layers made of the same material and formed in the same process are physically separated. For example, an island-like light-emitting layer refers to a state in which the light-emitting layer is physically separated from the adjacent light-emitting layer.

[0037] In this specification and the like, the term "step discontinuity" refers to a phenomenon in which a layer, film, or electrode is separated due to the shape of the surface on which it is formed (for example, a step).

[0038] In this specification, a tapered shape refers to a shape in which part or all of the side surface of a structure is inclined relative to the substrate surface or the surface on which a substrate is to be formed. In this specification, the angle between the inclined side surface and the substrate surface or the surface on which a substrate is to be formed is sometimes referred to as a taper angle. The side surface of the structure, the substrate surface, and the surface on which a substrate is to be formed do not necessarily have to be completely flat, but may be substantially planar with a slight curvature or a substantially planar with a slight unevenness.

[0039] Embodiment 1 In this embodiment, a display device of one embodiment of the present invention will be described with reference to FIGS.

[0040] A display device according to one embodiment of the present invention has a plurality of subpixels in a pixel. Each subpixel has a light-emitting device containing the same light-emitting material. Some or all of the subpixels have a coloring layer and / or a color conversion layer overlapping the light-emitting device. For example, by providing a coloring layer that transmits visible light of different colors depending on the subpixel, the display device can display full colors. Furthermore, by changing the presence or absence of a color conversion layer and the type of color conversion layer used depending on the subpixel, the display device can display full colors.

[0041] When light-emitting devices with the same light-emitting material are used, layers other than the pixel electrode (e.g., the light-emitting layer) included in the light-emitting device can be shared by multiple subpixels. This allows multiple subpixels to share a continuous film. However, some layers included in the light-emitting device have relatively high conductivity. When multiple subpixels share a highly conductive layer as a continuous film, leakage current may occur between adjacent subpixels. In particular, as display devices become higher in resolution or aperture ratio and the distance between adjacent subpixels becomes smaller, this leakage current becomes significant and may cause a deterioration in the display quality of the display. For example, current leakage to adjacent light-emitting devices may cause light emission from devices other than the desired light-emitting device (also known as crosstalk).

[0042] 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 light-emitting device is formed in an island shape. Separating at least a portion of the layers constituting the EL layer for each light-emitting device can suppress crosstalk between adjacent subpixels. This allows the display device to achieve high color reproducibility and high contrast, thereby achieving both high resolution and high display quality. In the display device according to one embodiment of the present invention, some of the layers constituting the EL layer in some subpixels may be formed in an island shape. In this case, the some of the layers may be continuous in the other subpixels. In this case, the continuous layer preferably has a locally thin portion. By configuring the EL layer to have a thin portion (which can also be referred to as a thin portion), crosstalk between adjacent subpixels can be suppressed.

[0043] For example, an island-shaped EL layer can be formed by vacuum deposition using a metal mask. However, this method can cause deviations in the shape and position of the island-shaped EL layer 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 spreading 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 EL layer formed using a metal mask can vary depending on the location. Furthermore, when manufacturing large, high-resolution, or high-definition display devices, there is a concern that low manufacturing yields may be caused by the low dimensional accuracy of the metal mask and deformation due to heat, etc.

[0044] Therefore, when manufacturing a display device according to one embodiment of the present invention, an island-shaped EL layer is formed without using a shadow mask (for example, a metal mask).

[0045] For example, the greater the difference in height between the upper surface of the insulating layer exposed between adjacent pixel electrodes and the upper surface of the pixel electrode (which can also be referred to as the step between adjacent pixel electrodes), the easier it is to form locally thin portions in the EL layer or even to divide the EL layer to form island-shaped EL layers for each light-emitting device. By utilizing the step between adjacent pixel electrodes, the EL layer can be partially thinned or divided in a self-aligned manner when forming the EL layer. In other words, crosstalk can be suppressed without increasing the number of processes, and a display device with high color reproducibility and contrast can be realized.

[0046] In a manufacturing method of a display device according to one embodiment of the present invention, a groove is provided in an insulating layer exposed between adjacent pixel electrodes in order to increase a step between adjacent pixel electrodes. After the groove is provided, an EL layer is formed, and the EL layer can be divided by using the groove.

[0047] If the EL layer has a thin portion or is separated for each light-emitting device, the common electrode may come into contact with the exposed portion of the pixel electrode, which may cause a short circuit in the light-emitting device.

[0048] Furthermore, if the step between adjacent pixel electrodes is large, the step may cause a disconnection of the common electrode provided on the EL layer.

[0049] Therefore, in a method for manufacturing a display device according to one embodiment of the present invention, an insulating layer is provided to cover the side surfaces of the pixel electrode and the island-shaped EL layer. The insulating layer preferably also covers part of the top surface of the island-shaped EL layer. Then, a common electrode is provided to cover the insulating layer and the EL layer.

[0050] This prevents the pixel electrode and the common electrode from coming into contact with each other. This prevents short circuits in the light-emitting device and improves the reliability of the light-emitting device. It also prevents the common electrode from being disconnected due to a step between adjacent pixel electrodes. This prevents poor connection of the common electrode. It also prevents the common electrode from being locally thinned, which would increase the electrical resistance of the common electrode.

[0051] In a light-emitting device, all layers constituting the EL layer do not need to be formed in an island shape, and some layers may be a continuous film shared by multiple light-emitting devices. 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, an insulating layer is provided to cover the side surfaces of the pixel electrode and the island-shaped EL layer, and the remaining layers constituting the EL layer (sometimes referred to as a common layer) and a common electrode (also referred to as an upper electrode) are formed on the insulating layer in common to multiple light-emitting devices (as a single film). For example, a carrier injection layer and a common electrode can be formed in common to multiple light-emitting devices.

[0052] Although it is difficult to reduce the distance between adjacent light-emitting devices (which can also be referred to as the shortest distance) to less than 10 μm using, for example, a formation method using a fine metal mask, according to a manufacturing method of a display device of one embodiment of the present invention, in a process on a glass substrate, for example, the distance between adjacent light-emitting devices, the distance between adjacent island-shaped EL layers, or the distance between adjacent pixel electrodes can be reduced to less than 10 μm, 8 μm or less, 5 μm or less, 3 μm or less, 2 μm or less, 1.5 μm or less, 1 μm or less, or 0.5 μm or less. Furthermore, in a process on a Si wafer, for example, by using an exposure apparatus for LSIs, the distance between adjacent light-emitting devices, the distance between adjacent island-shaped EL layers, or the distance between adjacent pixel electrodes can be reduced to, for example, 500 nm or less, 200 nm or less, 100 nm or less, or even 50 nm or less. This allows the area of ​​a non-light-emitting region that may exist between two light-emitting devices to be significantly reduced, enabling the aperture ratio to approach 100%. For example, in a display device of one embodiment of the present invention, the aperture ratio can be 40% or more, 50% or more, 60% or more, 70% or more, 80% or more, or even 90% or more, but less than 100%.

[0053] Increasing the aperture ratio of a display device can improve the reliability of the display device. Specifically, as the aperture ratio increases, the current density flowing through the light-emitting device required to obtain the same display can be reduced, thereby improving the lifespan of the display device.

[0054] The resolution of the display device of one embodiment of the present invention can be, for example, 1000 ppi or more, preferably 2000 ppi or more, more preferably 3000 ppi or more, more preferably 5000 ppi or more, and even more preferably 6000 ppi or more, and can be 20000 ppi or less, or 30000 ppi or less.

[0055] In this embodiment, a cross-sectional structure of a display device according to one embodiment of the present invention will be mainly described, and a manufacturing method of the display device according to one embodiment of the present invention will be described in detail in Embodiment 2.

[0056] [Display Device 100A] FIG. 1A shows a top view of the display device 100A. Note that in the top view of the display device used in this embodiment, some elements are omitted for clarity. FIG. 1B shows a cross-sectional view taken along dashed dotted line A1-A2 in FIG. 1A. FIG. 1C shows an enlarged view of the pixel electrodes and their vicinity. The pixel electrodes 111a, 111b, and 111c in the display device 100A shown in FIG. 1B have the same configuration as the pixel electrode 111 shown in FIG. 1C. Note that in FIG. 1C, some elements are omitted for clarity.

[0057] The display device 100A has a display section in which a plurality of pixels 110 are arranged, and a connection section 140 on the outside of the display section. A plurality of light-emitting devices are arranged in a matrix in the display section. The connection section 140 can also be called a cathode contact section.

[0058] A stripe arrangement is applied to the pixel 110 shown in FIG. 1A . The pixel 110 shown in FIG. 1A includes three subpixels. The three subpixels emit light of different colors. Examples of the three subpixels include subpixels of three colors: red (R), green (G), and blue (B), and subpixels of three colors: yellow (Y), cyan (C), and magenta (M). The number of types of subpixels is not limited to three and may be four or more. Examples of the four subpixels include subpixels of four colors: R, G, B, and white (W), subpixels of R, G, B, and Y, and subpixels of R, G, B, and infrared (IR). Note that a pixel layout applicable to a display device according to one embodiment of the present invention will be described in detail in Embodiment 3.

[0059] 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 ). FIG. 1A shows an example in which subpixels of different colors are arranged side by side in the Y direction, and subpixels of the same color are arranged side by side in the X direction.

[0060] FIG. 1A shows an example in which the connection portion 140 is located on the right side of the display unit in a plan view (also referred to as a top view), but the location of the connection portion 140 is not particularly limited. The connection portion 140 may be located in at least one of the upper, right, left, and lower sides of the display unit in a top view, and may be located in two or more locations. For example, the connection portion 140 may be located so as to surround all four sides of the display unit. The top surface shape of the connection portion 140 may be, for example, a strip shape, an L-shape, a U-shape, or a frame shape. Furthermore, the number of connection portions 140 may be singular or multiple. In this specification, the top surface shape of a certain component refers to the contour shape of the component in a plan view. Furthermore, a plan view refers to a view from the normal direction of the surface on which the component is formed or the surface of a support (e.g., a substrate) on which the component is formed.

[0061] As shown in FIG. 1B , the display device 100A includes an insulating layer 102 on a transistor-containing layer 101, a plug 103 in an opening of the insulating layer 102, light-emitting devices 130a, 130b, and 130c on the insulating layer 102, and a protective layer 131 covering these light-emitting devices. Colored layers 132R, 132G, and 132B are provided on the protective layer 131, and a substrate 120 is bonded to the colored layers 132R, 132G, and 132B with a resin layer 122. The colored layer 132R is provided in a position overlapping the light-emitting device 130a. The colored layer 132G is provided in a position overlapping the light-emitting device 130b. The colored layer 132B is provided in a position overlapping the light-emitting device 130c. Furthermore, an insulating layer 125 and an insulating layer 127 on the insulating layer 125 are provided in the region between adjacent light-emitting devices.

[0062] 1B shows multiple cross sections of insulating layer 125 and insulating layer 127, but when display device 100A is viewed from above, insulating layer 125 and insulating layer 127 are each connected to one another. In other words, display device 100A can be configured to have, for example, one insulating layer 125 and one insulating layer 127. Note that display device 100A may have multiple insulating layers 125 that are separated from one another, or may have multiple insulating layers 127 that are separated from one another.

[0063] The display device of one embodiment of the present invention may be any of a top-emission type that emits light in a direction opposite to a substrate on which a light-emitting device is formed, a bottom-emission type that emits light toward a substrate on which a light-emitting device is formed, and a dual-emission type that emits light to both sides. In this embodiment, a top-emission display device will be described as an example.

[0064] FIG. 1A shows the pixel electrode 111a of the light-emitting device 130a, the pixel electrode 111b of the light-emitting device 130b, and the pixel electrode 111c of the light-emitting device 130c. FIG. 1A also shows a groove 175 in the insulating layer 102. In a top view, the groove 175 is provided in a portion of the insulating layer 102 that does not overlap with the pixel electrodes in the display section. Grooves 175 of this shape can be formed using the pixel electrodes (and the resist mask used when forming the pixel electrodes) as a mask, which is preferable because it does not require the preparation of a separate mask. Furthermore, the grooves 175 extend to the dashed lines inside the pixel electrodes 111a, 111b, and 111c. In other words, it can be said that a portion of the groove 175 is located below the pixel electrodes 111a, 111b, and 111c.

[0065] 1A, the pixel electrodes 111a, 111b, and 111c are shown to have the same or approximately the same size, but one embodiment of the present invention is not limited to this. The aperture ratios of the light-emitting devices 130a, 130b, and 130c can be determined as appropriate and may be different from one another, or two or more may be equal or approximately equal.

[0066] In this embodiment, an example will be described in which the pixel 110 is composed of three sub-pixels: a sub-pixel that emits red light, a sub-pixel that emits green light, and a sub-pixel that emits blue light.

[0067] The sub-pixel that emits red light has a light-emitting device 130a and a colored layer 132R that transmits red light, so that light emitted from the light-emitting device 130a is extracted as red light to the outside of the display device via the colored layer 132R.

[0068] The subpixel that emits green light has a light-emitting device 130b and a colored layer 132G that transmits green light, so that light emitted from the light-emitting device 130b is extracted as green light to the outside of the display device via the colored layer 132G.

[0069] The sub-pixel that emits blue light has a light-emitting device 130c and a colored layer 132B that transmits blue light, so that light emitted from the light-emitting device 130c is extracted as blue light to the outside of the display device via the colored layer 132B.

[0070] Here, examples of blue light include light whose emission spectrum has a peak wavelength of 400 nm or more and less than 480 nm, examples of green light include light whose emission spectrum has a peak wavelength of 480 nm or more and less than 580 nm, and examples of red light include light whose emission spectrum has a peak wavelength of 580 nm or more and less than 700 nm.

[0071] The colored layer is a colored layer that selectively transmits light in a specific wavelength range and absorbs light in other wavelength ranges. For example, a color filter that transmits light in the red wavelength range can be used for the colored layer 132R. For example, a color filter that transmits light in the green wavelength range can be used for the colored layer 132G. For example, a color filter that transmits light in the blue wavelength range can be used for the colored layer 132B. Examples of materials that can be used for the colored layers include metal materials, resin materials, and resin materials containing pigments or dyes.

[0072] The layer 101 including transistors includes at least a substrate and a plurality of transistors on the substrate. The layer 101 including transistors may include one or more insulating layers between the substrate and the transistors. The layer 101 including transistors may also include one or more insulating layers covering the transistors.

[0073] The layer 101 including a transistor preferably includes a pixel circuit for driving a light-emitting device, and further preferably includes a driver circuit (such as a gate driver or a source driver) for driving the pixel circuit.

[0074] A structural example of the layer 101 including a transistor will be described later in Embodiment 4.

[0075] The insulating layer 102 is provided between the layer 101 including the transistor and the light-emitting devices, and has a groove 175 (which can also be called a recess) between two adjacent light-emitting devices. This results in a large step between adjacent pixel electrodes when forming the first layer 113 described later, making it easy to separate the first layer 113 and form it for each light-emitting device.

[0076] In Figure 1A, grooves are provided both between subpixels exhibiting different colors and between subpixels exhibiting the same color. In a display device according to one embodiment of the present invention, grooves are preferably provided at least between subpixels exhibiting different colors. This can prevent current from flowing to an adjacent subpixel and causing light emission of a different color. Therefore, high color reproducibility and high contrast can be achieved.

[0077] The insulating layer 102 may have a single-layer structure or a stacked structure of two or more layers. The insulating layer 102 can be formed using one or both of an inorganic insulating film and an organic insulating film.

[0078] Examples of inorganic insulating films that can be used for the insulating layer 102 include an insulating oxide film, an insulating nitride film, an insulating oxynitride film, and an insulating nitride oxide film.

[0079] Examples of oxide insulating films include silicon oxide films, aluminum oxide films, gallium oxide films, germanium oxide films, yttrium oxide films, zirconium oxide films, lanthanum oxide films, neodymium oxide films, hafnium oxide films, and tantalum oxide films. Examples of nitride insulating films include silicon nitride films and aluminum nitride films. Examples of oxynitride insulating films include silicon oxynitride films and aluminum oxynitride films. Examples of nitride oxide insulating films include silicon nitride oxide films and aluminum nitride oxide films.

[0080] 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.

[0081] Examples of organic insulating materials that can be used for the insulating layer 102 include acrylic resins, polyimide resins, epoxy resins, imide resins, polyamide resins, polyimideamide resins, silicone resins, siloxane resins, benzocyclobutene-based resins, phenolic resins, and precursors of these resins.

[0082] The groove 175 preferably has a downwardly convex arc shape in a cross-sectional view, as shown in, for example, FIGS. 1B and 1C . The insulating layer 102 provided with such a groove 175 can also be said to have a concave curved surface (which can also be referred to as a concave curved surface). The downwardly convex arc shape includes a downwardly convex semicircular shape. By forming the groove 175 in the above shape, the first layer 113 can be easily separated between adjacent light-emitting devices. This can suppress leakage current flow between adjacent light-emitting devices. Therefore, light emission caused by the leakage current can be suppressed, resulting in a high-contrast display. Furthermore, even when the resolution is increased, a highly conductive material can be used for the first layer 113, broadening the range of material options and facilitating improved light-emitting efficiency, reduced power consumption, and improved reliability.

[0083] It is preferable that a part of the groove 175 is located below the pixel electrode 111. In other words, it is preferable that the groove 175 has a region located below the pixel electrode 111. It is preferable that the groove 175 has a portion overlapping with the pixel electrode, because this makes it easier to divide the first layer 113.

[0084] The groove 175 preferably has, for example, a first region overlapping with the pixel electrode 111a, a second region overlapping with the pixel electrode 111b, a third region overlapping with the pixel electrode 111c, and a fourth region not overlapping with any of the pixel electrodes 111a, 111b, and 111c. The fourth region is located between the first and second regions, between the second and third regions, and between the first and third regions. The first to third regions each overlap with an end of a pixel electrode. The first region can be said to be located below the pixel electrode 111a. The second region can be said to be located below the pixel electrode 111b. The third region can be said to be located below the pixel electrode 111c.

[0085] 1B and 1C is the width of the region of the groove 175 in the Y direction that does not overlap with the pixel electrode 111. In the display device 100A shown in FIGS. 1B and 1C, the width W1 can be rephrased as the shortest distance between the ends of the pixel electrodes 111 that face each other. Furthermore, the width W2 shown in FIG. 1C is the width of the region of the groove 175 that overlaps with the pixel electrode 111 in the Y direction.

[0086] The width W1 is preferably at least twice the film thickness of the first layer 113. The width W1 is preferably at least two times and at most 12 times the film thickness of the first layer 113, more preferably at least two times and at most 10 times, and even more preferably at least two times and at most 9 times. This allows the grooves 175 to create discontinuities in the first layer 113, making it easier to form island-shaped first layers 113 on the pixel electrodes 111. At this time, as shown in FIG. 1B , the first layer 113 is disposed so as to cover the side and top surfaces of the pixel electrodes 111. In this specification, "a layer covering a structure" refers to a state in which the layer covers a portion of the end face of the structure, or a state in which the layer completely covers the end face of the structure.

[0087] The width W1 can be adjusted as appropriate depending on the processing accuracy when forming the groove 175, the film formation conditions of the first layer 113, and the like. When the first layer 113 is formed by, for example, a vacuum deposition method, a step may occur in the first layer 113 even if the width W1 is less than twice the film thickness of the first layer 113. For example, the width W1 may be 1 time or more and 12 times or less, 10 times or less, or 9 times or less the film thickness of the first layer 113.

[0088] The width W2 may be any width that causes a discontinuity in the first layer 113. The width W2 is preferably 2 nm or more, 5 nm or more, 10 nm or more, or 20 nm or more, and is preferably 500 nm or less, 300 nm or less, 200 nm or less, 150 nm or less, or 100 nm or less.

[0089] The plug 103 electrically connects an electrode or wiring included in the transistor-containing layer 101 to a pixel electrode included in the light-emitting device. The plug 103 is provided so as to fill an opening provided in the insulating layer 102. It is preferable that the surface of the insulating layer 102 that contacts the pixel electrode and the surface of the plug 103 that contacts the pixel electrode are aligned or approximately aligned.

[0090] Examples of conductive materials that can be used for the plug 103 include metals such as aluminum, titanium, chromium, nickel, copper, yttrium, zirconium, molybdenum, gold, silver, platinum, magnesium, iron, cobalt, palladium, tantalum, and tungsten, alloys containing one or more of these metal materials, and nitrides of these metal materials. The plug 103 may have a single-layer structure or a stacked structure of two or more layers.

[0091] Examples of the plug 103 include a single-layer structure of an aluminum film containing silicon, a two-layer structure in which an aluminum film is stacked on a titanium film, a two-layer structure in which an aluminum film is stacked on a tungsten film, a two-layer structure in which a copper film is stacked on a copper-magnesium-aluminum alloy film, a two-layer structure in which a copper film is stacked on a titanium film, a two-layer structure in which a copper film is stacked on a tungsten film, a three-layer structure in which a titanium film or titanium nitride film is stacked on top of an aluminum film or copper film, and a titanium film or titanium nitride film is further formed on top of that, and a three-layer structure in which a molybdenum film or molybdenum nitride film is stacked on top of an aluminum film or copper film, and a molybdenum film or molybdenum nitride film is further formed on top of that. Oxides such as indium oxide, tin oxide, or zinc oxide may also be used. Using copper containing manganese is preferable because it improves the controllability of the shape by etching.

[0092] As the light-emitting device, for example, an OLED (organic light-emitting diode) or a QLED (quantum-dot light-emitting diode) is preferably used. Examples of the light-emitting material contained in the light-emitting device include a fluorescent material (fluorescent material), a phosphorescent material (phosphorescent material), a material that exhibits thermally activated delayed fluorescence (thermally activated delayed fluorescence: TADF material), and an inorganic compound (such as a quantum dot material). Furthermore, an LED such as a micro LED (light-emitting diode) can also be used as the light-emitting device.

[0093] The light emitting device may emit light of a color, for example, infrared, red, green, blue, cyan, magenta, yellow, or white.

[0094] Of the pair of electrodes (pixel electrode and common electrode) that a light-emitting device has, it is preferable to use a conductive film that transmits visible light for the electrode from which light is extracted, and a conductive film that reflects visible light for the electrode from which light is not extracted.

[0095] Materials for forming the pair of electrodes of a light-emitting device include, for example, metals, alloys, electrically conductive compounds, and mixtures thereof. Specific examples of such materials include metals such as aluminum, magnesium, titanium, chromium, manganese, iron, cobalt, nickel, copper, gallium, zinc, indium, tin, molybdenum, tantalum, tungsten, palladium, gold, platinum, silver, yttrium, and neodymium, as well as alloys containing appropriate combinations of these metals. Examples of such materials 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), and In-W-Zn oxide. Examples of such materials include aluminum-containing alloys (aluminum alloys), such as an alloy of aluminum, nickel, and lanthanum (Al-Ni-La), as well as silver-magnesium alloys and silver-palladium-copper alloys (Ag-Pd-Cu, also referred to as APC). Other examples of the material include elements belonging to Group 1 or 2 of the periodic table (e.g., lithium, cesium, calcium, and strontium) that are not listed above as examples, rare earth metals such as europium and ytterbium, alloys containing appropriate combinations of these, and graphene.

[0096] It is preferable that a micro-optical resonator (microcavity) structure is applied to the light-emitting device. Therefore, it is preferable that one of the pair of electrodes of the light-emitting device has an electrode that is transparent and reflective to visible light (semi-transmissive / semi-reflective electrode), and the other has an electrode that is reflective to visible light (reflective electrode). By having a light-emitting device with a microcavity structure, light emitted from the light-emitting layer can be resonated between the two electrodes, thereby intensifying the light emitted from the light-emitting device. By providing a light-emitting device with a microcavity structure, it is possible to improve color purity.

[0097] That is, an electrode that is transparent to visible light (transparent electrode) or a semi-transparent / semi-reflective electrode can be used as the electrode on the side from which light is extracted in a light-emitting device.

[0098] The light transmittance of the transparent electrode is 40% or more. For example, it is preferable to use an electrode having a visible light (light with a wavelength of 400 nm or more and less than 750 nm) transmittance of 40% or more for the transparent electrode of a light-emitting device. The visible light reflectance of the semi-transmissive / semi-reflective electrode is 10% or more and 95% or less, preferably 30% or more and 80% or less. The visible light reflectance of the reflective electrode is 40% or more and 100% or less, preferably 70% or more and 100% or less. The resistivity of these electrodes is 1×10 −２ Preferably, it is Ωcm or less.

[0099] The pixel electrode and the common electrode may each have a single layer structure or a laminated structure.

[0100] 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.

[0101] The light-emitting device 130 a has a pixel electrode 111 a on the insulating layer 102 , an island-shaped first layer 113 on the pixel electrode 111 a , a common layer 114 on the first layer 113 , and a common electrode 115 on the common layer 114 .

[0102] The light-emitting device 130 b has a pixel electrode 111 b on the insulating layer 102 , an island-shaped first layer 113 on the pixel electrode 111 b , a common layer 114 on the first layer 113 , and a common electrode 115 on the common layer 114 .

[0103] The light-emitting device 130 c has a pixel electrode 111 c on the insulating layer 102 , an island-shaped first layer 113 on the pixel electrode 111 c , a common layer 114 on the first layer 113 , and a common electrode 115 on the common layer 114 .

[0104] In the light-emitting devices 130a, 130b, and 130c, the first layer 113 and the common layer 114 can be collectively referred to as the EL layer.

[0105] In this specification and the like, among the EL layers included in the light-emitting devices, a layer provided in an island shape for each light-emitting device is referred to as a first layer 113, and a layer shared by a plurality of light-emitting devices is referred to as a common layer 114. Note that in this specification and the like, the first layer 113 may be referred to as an island-shaped EL layer, an EL layer formed in an island shape, or the like, without including the common layer 114.

[0106] The light-emitting devices 130a, 130b, and 130c each independently include an island-shaped first layer 113. These first layers 113 are formed in the same process and have the same configuration. Therefore, it can be said that these first layers 113 include the same light-emitting material.

[0107] The first layer 113 can be configured to emit white light. For example, the first layer 113 includes a first light-emitting material that emits blue light and a second light-emitting material that emits light with a wavelength longer than that of blue light.

[0108] In addition, by applying a microcavity structure, a light-emitting device having an EL layer configured to emit white light may emit light of a specific wavelength, such as red, green, or blue, intensified.

[0109] For example, by applying a configuration that emits white light to the first layer 113 and by applying a microcavity structure, red light can be emitted from the light-emitting device 130a, green light can be emitted from the light-emitting device 130b, and blue light can be emitted from the light-emitting device 130c.

[0110] Note that the display device 100A is an example of a configuration in which a light-emitting device and a coloring layer are combined, but a display device of one embodiment of the present invention can also be a configuration in which a light-emitting device and a color conversion layer are combined. A configuration in which a light-emitting device and a color conversion layer are combined will be described later with reference to FIGS.

[0111] The light-emitting device of the present embodiment may have a single structure (a structure having only one light-emitting unit) or a tandem structure (a structure having multiple light-emitting units). The light-emitting unit has one or more light-emitting layers.

[0112] The first layer 113 includes at least a light-emitting layer. For example, the first layer 113 may include a light-emitting layer that emits blue light and a light-emitting layer that emits light with a longer wavelength than the blue light.

[0113] Furthermore, when a light-emitting device with a tandem structure is used, the first layer 113 may have, for example, a light-emitting unit that emits blue light and a light-emitting unit that emits light with a wavelength longer than that of blue light. It is preferable to provide a charge generation layer between each light-emitting unit. By adopting a tandem structure, a light-emitting device capable of emitting light with high brightness can be realized.

[0114] In addition to the light-emitting layer, the first layer 113 may have one or more of a hole injection layer, a hole transport layer, a hole blocking layer, a charge generation layer, an electron blocking layer, an electron transport layer, and an electron injection layer.

[0115] For example, the first layer 113 may have, from the anode side, a hole injection layer, a hole transport layer, a light-emitting layer, an electron transport layer, and an electron injection layer in this order. Alternatively, the first layer 113 may have an electron blocking layer between the hole transport layer and the light-emitting layer. Alternatively, the first layer 113 may have a hole blocking layer between the electron transport layer and the light-emitting layer.

[0116] Also, for example, the first layer 113 may have a first light-emitting unit, a charge generation layer on the first light-emitting unit, and a second light-emitting unit on the charge generation layer.

[0117] The common layer 114 may include, 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 light-emitting devices 130 a, 130 b, and 130 c.

[0118] For more detailed information on the structure and materials of the light-emitting device, reference can be made to Embodiment 5.

[0119] In Figure 1B, the first layers 113 of each light-emitting device are spaced apart from one another. By providing the first layers 113 in an island shape for each light-emitting device, leakage current between adjacent light-emitting devices can be suppressed. This prevents unintended light emission due to crosstalk, and realizes a display device with extremely high contrast. In particular, it realizes a display device with high current efficiency at low brightness.

[0120] Furthermore, a material layer 113s, which is formed in the same process as the first layer 113 and has the same configuration as the first layer 113, is located on the insulating layer 102 (specifically, inside the groove 175). The material layer 113s is separated from the first layer 113 when the layers constituting the first layer 113 are formed, and is provided independently on the insulating layer 102. The material layer 113s is located between the insulating layer 125 and the insulating layer 102.

[0121] Note that the region where any one of the pixel electrodes 111a, 111b, and 111c overlaps with the first layer 113 and the common electrode 115 can be referred to as a light-emitting region, where EL light emission is obtained. The light-emitting region and the region where the material layer 113s is provided are regions where PL (Photoluminescence) light emission is obtained. From these facts, it can be said that the light-emitting region and the region where the material layer 113s is provided can be distinguished by checking the EL light emission and the PL light emission.

[0122] In FIG. 1B , an insulating layer (also referred to as a partition, bank, spacer, or the like) covering the upper end of the pixel electrode 111a is not provided between the pixel electrode 111a and the first layer 113. Furthermore, an insulating layer covering the upper end of the pixel electrode 111b is not provided between the pixel electrode 111b and the first layer 113. Therefore, the distance between adjacent light-emitting devices can be made extremely narrow. This allows a high-definition or high-resolution display device to be obtained. Furthermore, a mask for forming the insulating layer is not required, thereby reducing the manufacturing cost of the display device.

[0123] Furthermore, by using a structure in which an insulating layer covering a part of the top surface of the pixel electrode (which can also be referred to as an edge of the top surface) 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.

[0124] 1B, the first layer 113 is formed to cover the entire upper surface of each of the pixel electrodes 111a, 111b, and 111c. This configuration allows the entire upper surface of the pixel electrode to be used as a light-emitting region. Furthermore, compared to a configuration in which an insulating layer is provided to cover only a portion of the upper surface of the pixel electrode, it is easier to increase the aperture ratio.

[0125] 1B , the first layer 113 is formed so as to cover the side surfaces of the pixel electrodes 111 a, 111 b, and 111 c. In other words, the ends of the first layer 113 are located outside the ends of the pixel electrodes 111 a, 111 b, and 111 c. This prevents the pixel electrodes from coming into direct contact with the common electrode 115, thereby suppressing short circuits in the light-emitting device.

[0126] The common electrode 115 is shared by the light-emitting devices 130a, 130b, and 130c. The common electrode 115 shared by the plurality of light-emitting devices is electrically connected to a conductive layer provided in the connection portion 140. It is preferable that the connection portion 140 be provided with a conductive layer formed from the same material and in the same process as the pixel electrodes 111a, 111b, and 111c.

[0127] The insulating layer 125 is provided so as to cover the side surfaces of the first layer 113. The insulating layer 125 may further cover a portion of the top surface of the first layer 113. By covering both the side surfaces and a portion of the top surface of the first layer 113 with the insulating layer 125, peeling of the first layer 113 can be prevented, and the reliability of the light-emitting device can be improved.

[0128] The insulating layer 125 is provided to cover the groove 175. The insulating layer 125 preferably has a portion in contact with the insulating layer 102 in the groove 175. Specifically, the insulating layer 125 preferably contacts the sidewall of the groove. This allows the pixel electrode 111 and the first layer 113 to be sealed by the insulating layer 102 and the insulating layer 125. The insulating layer 125 functions as a protective layer that prevents impurities such as water from diffusing into the pixel electrode 111 and the first layer 113.

[0129] The insulating layer 125 has an opening that reaches the first layer 113. In the opening, the first layer 113 is in contact with the common layer 114. In addition, the common electrode 115 has a region that overlaps with the first layer 113 through the opening.

[0130] The insulating layer 125 has a region located between the insulating layer 127 and the first layer 113 and functions as a protective film for preventing the insulating layer 127 from contacting the first layer 113. When the first layer 113 and the insulating layer 127 come into contact with each other, the first layer 113 may be dissolved by an organic solvent or the like used in forming the insulating layer 127. Therefore, by providing the insulating layer 125 between the first layer 113 and the insulating layer 127 as shown in this embodiment, the side surfaces of the first layer 113 can be protected.

[0131] The insulating layer 125 may have a single-layer structure or a stacked structure of two or more layers. The insulating layer 125 can be formed using one or both of an inorganic insulating film and an organic insulating film.

[0132] Examples of inorganic insulating films that can be used for the insulating layer 125 include an insulating oxide film, an insulating nitride film, an insulating oxynitride film, and an insulating nitride oxide film. Specific examples of these inorganic insulating films are as described for the insulating layer 102. Alternatively, a magnesium oxide film or an indium gallium zinc oxide film may be used for the insulating layer 125. In particular, by using an inorganic insulating film such as an aluminum oxide film, a metal oxide film such as a hafnium oxide film, or a silicon oxide film formed by an ALD method as the insulating layer 125, the insulating layer 125 can have few pinholes and can protect the first layer 113.

[0133] The insulating layer 125 may also function as a protective layer that prevents impurities such as water from diffusing into the first layer 113. The insulating layer 125 is preferably an inorganic insulating film with low moisture permeability, such as a silicon oxide film, a silicon nitride film, or an aluminum oxide film.

[0134] Between adjacent light-emitting devices, the side surfaces of the first layers 113 face each other with an insulating layer 127 interposed therebetween. The insulating layer 127 is provided so as to fill the grooves 175. The insulating layer 127 has a smooth, convex upper surface, and a common layer 114 and a common electrode 115 are provided to cover the upper surface of the insulating layer 127.

[0135] The insulating layer 127 functions as a planarizing film that fills in the steps between adjacent light-emitting devices. By providing the insulating layer 127, it is possible to prevent the common electrode 115 from being disconnected by the groove 175.

[0136] The upper surface of the insulating layer 127 preferably has a highly flat shape, but may have a convex portion, a convex curved surface, a concave curved surface, or a concave portion. For example, the upper surface of the insulating layer 127 preferably has a highly flat, smooth convex curved surface shape.

[0137] An insulating layer containing an organic material can be suitably used as the insulating layer 127. Specific examples of organic insulating materials that can be used for the insulating layer 127 are as described for the insulating layer 102. Alternatively, the insulating layer 127 may be made of an organic material such as polyvinyl alcohol (PVA), polyvinyl butyral, polyvinylpyrrolidone, polyethylene glycol, polyglycerin, pullulan, water-soluble cellulose, or an alcohol-soluble polyamide resin.

[0138] Furthermore, a photosensitive resin can be used for the insulating layer 127. A photoresist can be used as the photosensitive resin. The photosensitive resin can be a positive-type material or a negative-type material.

[0139] The insulating layer 127 may contain a material that absorbs visible light. That is, the insulating layer 127 may be a colored layer. For example, the insulating layer 127 itself may be made of a material that absorbs visible light, or the insulating layer 127 may contain a pigment that absorbs visible light. For example, the insulating layer 127 may be made of a resin that can be used as a color filter that transmits red, blue, or green light and absorbs other light, or a resin that contains carbon black as a pigment and functions as a black matrix.

[0140] The insulating layer 127 absorbs visible light, thereby preventing light emitted from the light-emitting device from leaking into adjacent subpixels.

[0141] Furthermore, the insulating layer 127 can absorb visible light, thereby preventing light emitted by the light-emitting device from entering the layer 101 including the transistor. For example, when 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 is used as the transistor, the reliability of the OS transistor can be improved by reducing the amount of light incident on the OS transistor. Specifically, negative bias light photodegradation of the OS transistor can be suppressed. In this case, the insulating layer 127 preferably absorbs blue light and light with higher energy (shorter wavelength) than blue light.

[0142] Note that it is not necessary to provide one of the insulating layers 125 and 127. For example, depending on the materials of the first layer 113 and the insulating layer 127, it may be possible to provide the first layer 113 and the insulating layer 127 in contact with each other without providing the insulating layer 125. Furthermore, depending on the shape of the groove 175 and the thickness of each layer constituting the light-emitting device, it may be possible to form the common electrode 115 without discontinuing the insulating layer 127.

[0143] It is preferable that the light-emitting devices 130a, 130b, and 130c have a protective layer 131. The reliability of the light-emitting devices 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.

[0144] There is no restriction on the conductivity of the protective layer 131. The protective layer 131 can be formed using one or more of an insulating film, a semiconductor film, and a conductive film.

[0145] The protective layer 131 having an inorganic film can, for example, prevent oxidation of the common electrode 115 and suppress impurities (such as moisture and oxygen) from entering the light-emitting device, thereby suppressing deterioration of the light-emitting device and improving the reliability of the display device.

[0146] Examples of inorganic insulating films that can be used for the protective layer 131 include an insulating oxide film, an insulating nitride film, an insulating oxynitride film, and an insulating nitride oxide film. Specific examples of these inorganic insulating films are as described for the insulating layer 102. In particular, the protective layer 131 preferably includes an insulating nitride film or an insulating nitride oxide film, and more preferably includes an insulating nitride film.

[0147] Alternatively, an inorganic film containing 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.

[0148] 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.

[0149] 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.

[0150] 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.

[0151] The protective layer 131 may have an organic insulating film. Specific examples of organic insulating materials that can be used for the protective layer 131 are as described for the insulating layer 102. Alternatively, the protective layer 131 may be made of an organic material such as polyvinyl alcohol (PVA), polyvinyl butyral, polyvinylpyrrolidone, polyethylene glycol, polyglycerin, pullulan, water-soluble cellulose, or an alcohol-soluble polyamide resin.

[0152] The protective layer 131 may also be a laminated film of an inorganic insulating film and an organic insulating film. For example, a configuration in which an organic insulating film is sandwiched between a pair of inorganic insulating films is preferable. Furthermore, it is preferable that the organic insulating film functions as a planarizing film. This allows the upper surface of the organic insulating film to be flat, thereby improving the coverage of the inorganic insulating film thereon and enhancing the barrier properties. Furthermore, since the upper surface of the protective layer 131 is flat, when a structure (e.g., one or more of a color filter, a color conversion layer, a touch sensor electrode, and a lens array) is provided above the protective layer 131, the influence of uneven shapes caused by the structure below can be reduced, which is preferable.

[0153] 1B and other figures, when colored layers 132R, 132G, 132B, and the like are formed directly on the protective layer 131, it is preferable to use a layer having a planarizing function for the protective layer 131. By using an organic film for the protective layer 131, the planarity of the surface of the protective layer 131 can be improved, which is preferable.

[0154] A light-shielding layer may be provided on the surface of the substrate 120 facing the resin layer 122. Various optical members may be disposed on the outer side of the substrate 120 (the surface opposite the resin layer 122). Examples of optical members include a polarizing plate, a retardation plate, a light diffusion layer (such as a diffusion film), an anti-reflection layer, and a light-collecting film. Furthermore, a surface protection layer such as an anti-static film that suppresses the adhesion of dust, a water-repellent film that makes it difficult for dirt to adhere, a hard coat film that suppresses scratches during use, or an impact absorbing layer may be disposed on the outer side of the substrate 120. For example, a glass layer or a silica layer (SiO ｘ The surface protection layer can be preferably formed of, for example, diamond-like carbon (DLC), aluminum oxide (AlO ｘ ), polyester-based materials, or polycarbonate-based materials may be used. Note that it is preferable to use a material with high transmittance to visible light for the surface protection layer. It is also preferable to use a material with high hardness for the surface protection layer.

[0155] The substrate 120 can be made of, for example, glass, quartz, ceramics, sapphire, resin, metal, alloy, or semiconductor. 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.

[0156] For example, polyester resins such as polyethylene terephthalate (PET) and 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, or cellulose nanofiber can be used for the substrate 120. Glass having a thickness sufficient to provide flexibility may also be used for the substrate 120.

[0157] 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).

[0158] 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.

[0159] 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.

[0160] Furthermore, when a film is used as a substrate, the film may absorb water, causing wrinkles in the display device and changing the shape of the display device. 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.

[0161] 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.

[0162] Materials that can be used for conductive layers such as gates, sources, and drains of transistors and electrodes of light-emitting devices, as well as various wirings and electrodes that constitute display devices, include, for example, metals such as aluminum, titanium, chromium, nickel, copper, yttrium, zirconium, molybdenum, silver, tantalum, and tungsten, and alloys containing these metals as their main components. Films containing these materials can be used as single layers or as multilayer structures.

[0163] Light-transmitting conductive materials can also be used for conductive layers such as gates, sources, and drains of transistors and electrodes of light-emitting devices, as well as for various wirings and electrodes constituting a display device. Examples of light-transmitting conductive materials include conductive oxides such as indium oxide, indium tin oxide, indium zinc oxide, zinc oxide, and zinc oxide containing gallium, or graphene. Alternatively, metal materials such as gold, silver, platinum, magnesium, nickel, tungsten, chromium, molybdenum, iron, cobalt, copper, palladium, and titanium, or alloy materials containing such metal materials, can be used. Alternatively, nitrides of such metal materials (e.g., titanium nitride) can be used. When using metal materials or alloy materials (or their nitrides), it is preferable to thin the metal materials to ensure light-transmitting properties. A stacked film of the above materials can also be used as the conductive layer. For example, a stacked film of an alloy of silver and magnesium and indium tin oxide can be used because it can increase conductivity.

[0164] 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.

[0165] [Display Device 100B] Figure 2A shows a cross-sectional view of the display device 100B. Figure 2B shows an enlarged view of the pixel electrodes and their vicinity. The pixel electrodes 111a, 111b, and 111c in the display device 100B shown in Figure 2A have the same configuration as the pixel electrode 111 shown in Figure 2B. Note that some elements are omitted from Figure 2B for clarity.

[0166] 1B in that the insulating layer 102 has a two-layer structure. The insulating layer 102 includes an insulating layer 102a on the layer 101 including the transistor, and an insulating layer 102b having a groove on the insulating layer 102a.

[0167] The groove 175 of the display device 100B has a flat bottom surface and a concave curved side wall in a cross-sectional view.

[0168] The width W1 shown in Fig. 2B is the width of the region of the groove 175 in the Y direction that does not overlap with the pixel electrode 111. Note that in Fig. 2B, the width W1 can be rephrased as the shortest distance between the ends of the pixel electrodes 111 that face each other. The width W2 shown in Fig. 2B is the width of the region of the groove 175 that overlaps with the pixel electrode 111 in the Y direction.

[0169] The insulating layer 102a is preferably formed using an insulating material that functions as an etching stopper film when the insulating layer 102b is etched to form the groove 175. For example, when a silicon oxide film or a silicon oxynitride film is used as the insulating layer 102b, a silicon nitride film, an aluminum oxide film, or a hafnium oxide film may be used as the insulating layer 102a.

[0170] The insulating layer 102a functions as an etching stopper film, so that the depth of the groove 175 can be prevented from becoming too large even if the width W1 shown in FIG. 2B is large. This increases the degree of freedom in the shape (e.g., width and depth) of the groove 175. Note that for the preferred ranges of the width W1 and width W2 shown in FIG. 2B, the descriptions of the widths W1 and W2 shown in FIG. 1C can be referred to.

[0171] The depth of the groove 175 is preferably greater than the film thickness of the first layer 113. This configuration makes it possible to generate a discontinuity in the first layer 113. Note that in FIG. 2B, the depth of the groove 175 corresponds to the film thickness of the insulating layer 102b.

[0172] Although the display device 100B shows a configuration in which the insulating layer 102 has a two-layer structure of the insulating layer 102a and the insulating layer 102b, the present invention is not limited to this. For example, the insulating layer 102 may have a stacked structure of three or more layers, or one or both of the insulating layer 102a and the insulating layer 102b may have a stacked structure.

[0173] [Display Device 100C] Figure 3A shows a cross-sectional view of the display device 100C. The display device 100C differs from the display device 100A shown in Figure 1B in the configuration of the pixel electrodes. Figures 3B to 3D show enlarged views of the pixel electrodes and their vicinity. Note that some elements are omitted in Figures 3B to 3D for clarity.

[0174] The pixel electrodes 111a, 111b, and 111c in the display device 100C shown in Fig. 3A have the same configuration as the pixel electrode 111 shown in Fig. 3B. The pixel electrode 111 shown in Fig. 3B has a pixel electrode 111A and a pixel electrode 111B on the pixel electrode 111A.

[0175] 3C and 3D has a three-layer structure including a pixel electrode 111A, a pixel electrode 111B on the pixel electrode 111A, and a pixel electrode 111C covering the upper and side surfaces of the pixel electrodes 111A and 111B.

[0176] 3A to 3D , the edge of the pixel electrode may have a tapered shape. Specifically, the edge of the pixel electrode may have a tapered shape with a taper angle of less than 90° (also called a forward tapered shape). Alternatively, the edge of the pixel electrode may have a tapered shape with a taper angle of more than 90° (also called a reverse tapered shape).

[0177] 3B to 3D, it is preferable to use a single-layer structure of a titanium nitride film for the pixel electrode 111A. Also, in FIGS. 3B to 3D, it is preferable to use a single-layer structure of a titanium film or a three-layer structure in which a titanium film, an aluminum film, and a titanium film are stacked in this order for the pixel electrode 111B. By providing a titanium nitride film as the pixel electrode 111A, it is possible to prevent the bottom surface of the pixel electrode 111B (the bottom surface of the titanium film in the above example) from being damaged when forming a groove in the insulating layer 102. Also, the pixel electrode 111B in FIG. 3B may have an ITO film or ITSO film on a titanium film as its top layer.

[0178] 3C and 3D, when a single-layer structure of a titanium film is used for the pixel electrode 111B, it is preferable to use a three-layer structure in which an ITO film, an APC film, and an ITO film are laminated in this order as the pixel electrode 111C, or a three-layer structure in which an ITSO film, an APC film, and an ITSO film are laminated in this order as the pixel electrode 111C.

[0179] In addition, in Figures 3C and 3D, when a three-layer structure in which a titanium film, an aluminum film, and a titanium film are stacked in this order is used for the pixel electrode 111B, it is preferable to use a single-layer structure of an ITO film or a single-layer structure of an ITSO film for the pixel electrode 111C.

[0180] An aluminum film has high reflectivity and is suitable as a reflective electrode. However, in a structure in which aluminum and an oxide conductive layer are in contact with each other, galvanic corrosion may occur if a chemical solution comes into contact with the aluminum and the oxide conductive layer. Therefore, it is preferable to provide a titanium film between the aluminum film and the oxide conductive layer.

[0181] The shape of the insulating layer 102 shown in FIG. 3C can be formed, for example, by performing the step of forming the groove 175 after the formation of the pixel electrode 111C. In FIG. 3C, a portion of the groove 175 is located below the pixel electrode 111C. Alternatively, as shown in FIG. 3D, a portion of the groove 175 may be located below the pixel electrodes 111A, 111B, and 111C. The shape of the insulating layer 102 shown in FIG. 3D can be formed, for example, by performing the step of forming the groove 175 after the formation of the pixel electrode 111C. Alternatively, the insulating layer 102 shown in FIG. 3D can be formed even if the step of forming the groove 175 is performed after the formation of the pixel electrode 111B and before the formation of the pixel electrode 111C. The timing of forming the groove 175 can be determined appropriately depending on the chemical solution used to form the groove 175 and the materials of the pixel electrodes 111A, 111B, and 111C.

[0182] [Display Device 100D] Figure 4 shows a cross-sectional view of the display device 100D. The display device 100D differs from the display device 100A shown in Figure 1B in that each light-emitting device has an optical adjustment layer.

[0183] In the display device of one embodiment of the present invention, the pixel electrodes 111a, 111b, and 111c may have different thicknesses. In addition, in the display device of one embodiment of the present invention, optical adjustment layers having different thicknesses may be provided over the pixel electrodes 111a, 111b, and 111c.

[0184] In FIG. 4, an optical adjustment layer 116R is provided on the pixel electrode 111a, an optical adjustment layer 116G is provided on the pixel electrode 111b, and an optical adjustment layer 116B is provided on the pixel electrode 111c.

[0185] 4 shows an example in which the thickness of optical adjustment layer 116R is thicker than the thickness of optical adjustment layer 116G, which is thicker than the thickness of optical adjustment layer 116B. It is preferable to set the thickness of optical adjustment layer 116R so as to enhance red light, the thickness of optical adjustment layer 116G so as to enhance green light, and the thickness of optical adjustment layer 116B so as to enhance blue light. This allows for a microcavity structure to be realized, and the color purity of the light emitted by each light-emitting device to be improved.

[0186] The optical adjustment layer is preferably formed using a conductive material that is transparent to visible light, among conductive materials that can be used as electrodes of a light-emitting device.

[0187] [Display Devices 100E, 100F] Fig. 5A shows a cross-sectional view of the display device 100E, and Fig. 5B shows a cross-sectional view of the groove 175 and its vicinity of the display device 100E. Note that some elements are omitted from Fig. 5B for clarity. Fig. 5C shows a cross-sectional view of the display device 100F. The display devices 100E and 100F differ from the display device 100A in the shape of the groove 175.

[0188] As shown in FIG. 5A, the groove 175 of the display device 100E has an inverted T shape in a cross-sectional view of the display device 100E.

[0189] 5B has a region having a first width W3 and a region below the first width W3 having a second width W4, as viewed in cross section of the display device. Also, as shown in FIG. 5B, a width W5 is half the difference between the first width W3 and the second width W4, and a distance W6 is the shortest distance between the ends of the pixel electrodes 111 facing each other.

[0190] It is preferable that the first width W3 is smaller than the distance W6 and the second width W4 is larger than the first width W3, which makes it easier to generate a step discontinuity in the first layer 113.

[0191] As shown in FIG. 5C, the groove 175 of the display device 100F has a cross shape in a cross-sectional view of the display device 100F.

[0192] When the groove 175 has an inverted T shape as shown in FIGS. 5A and 5B or a cross shape as shown in FIG. 5C, the relationship between the second width W4 and the distance W6 is not particularly limited. FIGS. 5A and 5B show an example in which the second width W4 is greater than the distance W6. FIG. 5C shows an example in which the second width W4 is approximately equal to the distance W6. The second width W4 may be smaller than the distance W6, the same as the distance W6, or larger than the distance W6. When the second width W4 is smaller than the distance W6, the groove 175 is not located below the pixel electrode 111.

[0193] 5A to 5C, the insulating layer 102 preferably has a stacked structure of insulating layers 102a, 102b, and 102c. Furthermore, the materials used for the insulating layers 102a and 102c preferably have different etching rates from the material used for the insulating layer 102b. This structure allows the formation of a groove 175 having the shape shown in FIGS. 5A to 5C.

[0194] By forming the groove 175 in the above-described shape, the first layer 113 can be separated between adjacent light-emitting devices. This makes it possible to prevent leakage current between adjacent light-emitting devices. Therefore, as described above, a high-contrast display can be realized. Furthermore, it becomes easy to improve efficiency, reduce power consumption, and improve reliability.

[0195] The width W5 corresponds to the width W2 shown in Fig. 1C. Therefore, for the preferred range of the width W5, the description of the width W2 shown in Fig. 1C can be referred to.

[0196] In the display device 100E, the film thickness of the insulating layer 102b is preferably larger than the film thickness of the first layer 113. In addition, in the display device 100F, the sum of the film thickness of the insulating layer 102b and the depth of the groove provided in the insulating layer 102a is preferably larger than the film thickness of the first layer 113. With this configuration, it becomes easier to generate a discontinuity in the first layer 113.

[0197] 5A shows a configuration in which the thickness of the insulating layer 102b is greater than the thickness of the insulating layer 102c, but as long as a discontinuity occurs in the first layer 113, the relationship in magnitude between the thicknesses of the insulating layer 102b and the insulating layer 102c is not particularly limited. The thickness of the insulating layer 102b may be the same as the thickness of the insulating layer 102c, or may be smaller than the thickness of the insulating layer 102c. Similarly, the relationship in magnitude between the thicknesses of the insulating layer 102a and the insulating layer 102c is not particularly limited. Similarly, the relationship in magnitude between the thicknesses of the insulating layer 102a and the insulating layer 102b is not particularly limited.

[0198] 5A to 5C show an example in which the insulating layer 102 has a three-layer structure, but the configuration of the insulating layer 102 is not limited to this. For example, the insulating layer 102 may have a stacked structure of two layers or four or more layers, or any one or more of the insulating layer 102a, the insulating layer 102b, and the insulating layer 102c may have a stacked structure.

[0199] Here, a method for forming the grooves 175 of the display device 100E shown in FIG. 5A and the grooves 175 of the display device 100F shown in FIG. 5C will be described.

[0200] First, grooves having a first width W3 are formed in the insulating layers 102c and 102b to expose the top surface of the insulating layer 102a. The grooves are preferably formed by etching. When the grooves are formed, part of the top surface of the insulating layer 102a in a region overlapping the grooves may be removed.

[0201] Next, the side surfaces of the insulating layer 102b exposed in the grooves are etched using an isotropic etching method to recess the end surfaces (also called side etching), which causes the grooves in the insulating layer 102b to expand horizontally relative to the substrate surface, thereby creating regions of a second width W4 in the grooves 175.

[0202] In this manner, the grooves 175 of the display device 100E shown in FIG. 5A and the grooves 175 of the display device 100F shown in FIG. 5C can be formed.

[0203] [Display Device 200A] Fig. 6A shows a top view of the display device 200 A. In addition, since Fig. 1B can be referred to for a cross-sectional view between the dashed dotted line A1-A2 in Fig. 6A, detailed description thereof will be omitted.

[0204] FIG. 6A shows a pixel electrode 111a of the light-emitting device 130a, a pixel electrode 111b of the light-emitting device 130b, and a pixel electrode 111c of the light-emitting device 130c.

[0205] 6A also shows grooves 175_1, 175_2, and 175_3 in the insulating layer 102. The groove 175_1 is provided up to the dashed lines inside the pixel electrodes 111a and 111c. The groove 175_2 is provided up to the dashed lines inside the pixel electrodes 111a and 111b. The groove 175_3 is provided up to the dashed lines inside the pixel electrodes 111b and 111c. In other words, it can be said that a portion of the grooves 175_1, 175_2, and 175_3 is located below the pixel electrodes.

[0206] In FIG. 6A , the insulating layer 102 has a groove between two pixel electrodes 111 adjacent in the Y direction. This creates a large step between the pixel electrodes adjacent in the Y direction when the first layer 113 is formed, making it easy to separate the first layer 113 between subpixels exhibiting different colors. This prevents leakage current from flowing between the two light-emitting devices. Therefore, light emission caused by the leakage current can be suppressed, resulting in a high-contrast display. Furthermore, even when the resolution is increased, a highly conductive material can be used for the first layer 113, broadening the range of material options and facilitating improved light-emitting efficiency, reduced power consumption, and improved reliability.

[0207] On the other hand, no groove is provided between two pixel electrodes 111 adjacent in the X direction, so the first layer 113 is not divided between sub-pixels that exhibit the same color, but is formed as a continuous film.

[0208] When describing matters common to the grooves 175_1, 175_2, and 175_3, they may be referred to as grooves 175. When describing matters common to the pixel electrodes 111a, 111b, and 111c, they may be referred to as pixel electrodes 111.

[0209] FIG. 6B shows a top view of the end of groove 175 and its vicinity.

[0210] The groove 175 preferably extends in the X direction to a region outside the end of the first layer 113. In Fig. 6B, the distance from the end of the groove 175 to the end of the first layer 113 is shown as distance L0. This configuration makes it easy to separate the first layer 113 between light-emitting devices adjacent in the Y direction.

[0211] Although not shown in FIGS. 6A and 6B, it is preferable that the common electrode 115 extend to an area outside the ends of the grooves 175 in the X direction.

[0212] Here, a method for forming the grooves 175 of the display device 200A shown in FIGS. 6A and 6B will be described.

[0213] First, strip-shaped pixel electrodes are formed with their long sides aligned in the X direction. Then, the insulating layer 102 is etched using the pixel electrodes (and a resist mask for forming the strip-shaped pixel electrodes) as a mask to form grooves 175_1, 175_2, and 175_3 with their long sides aligned in the X direction. The strip-shaped pixel electrodes are then divided in the Y direction to form the island-shaped pixel electrodes shown in FIGS. 6A and 6B .

[0214] In this manner, the grooves 175 of the display device 200A shown in FIGS. 6A and 6B can be formed.

[0215] [Display Device 200B] FIG. 7A shows a top view of the display device 200B, and FIG. 7B shows a cross-sectional view taken along the dashed dotted line A3-A4 shown in FIG. 7A.

[0216] In the display device 200B, two grooves are provided between two light-emitting devices adjacent to each other in the Y direction.

[0217] 7A , the insulating layer 102 has two grooves between two pixel electrodes adjacent in the Y direction. As shown in FIGS. 7A and 7B , a groove 173_1b on the light-emitting device 130a side and a groove 173_2a on the light-emitting device 130b side are provided between the light-emitting device 130a (pixel electrode 111a) and the light-emitting device 130b (pixel electrode 111b). Similarly, a groove 173_2b on the light-emitting device 130b side and a groove 173_3a on the light-emitting device 130c side are provided between the light-emitting device 130b (pixel electrode 111b) and the light-emitting device 130c (pixel electrode 111c). Furthermore, a groove 173_1a on the light-emitting device 130a side and a groove 173_3b on the light-emitting device 130c side are provided between the light-emitting device 130a (pixel electrode 111a) and the light-emitting device 130c (pixel electrode 111c). When describing matters common to the grooves 173_1a, 173_2a, and 173_3a, the groove may be referred to as a groove 173a. When describing matters common to the grooves 173_1b, 173_2b, and 173_3b, the groove may be referred to as a groove 173b.

[0218] In the display device 200B, the first layer 113 is separated between two light-emitting devices adjacent in the Y direction by grooves 173a and 173b. This prevents leakage current from flowing between the two light-emitting devices. Therefore, light emission caused by the leakage current can be suppressed, resulting in a high-contrast display. Furthermore, even when the resolution is increased, a highly conductive material can be used for the first layer 113, broadening the range of material options and facilitating improved light-emitting efficiency, reduced power consumption, and improved reliability.

[0219] 7B has sidewalls perpendicular to the surface of the transistor-including layer 101 (substrate), but the shape of the sidewalls of the grooves 173a and 173b is not limited to this as long as a step is generated in the first layer 113. The sidewalls of the grooves 173a and 173b may have a tapered shape or an inverse tapered shape. Furthermore, the sidewalls of the grooves 173a and 173b may have a curved shape or a step.

[0220] The number of grooves provided in the insulating layer 102 in the region located between two pixel electrodes 111 adjacent in the Y direction is preferably one or two, but may be three or more.

[0221] As shown in FIG. 7B, the insulating layer 125 is provided in contact with the side surfaces of the first layer 113, and preferably also in contact with a portion of the top surface of the first layer 113.

[0222] 7B , the insulating layer 125 is provided so as to overlap with each of the grooves 173_1a, 173_1b, 173_2a, 173_2b, 173_3a, and 173_3b. The insulating layer 125 preferably has a portion in contact with the insulating layer 102. Specifically, the insulating layer 125 preferably contacts the sidewalls of the grooves. As a result, the pixel electrode 111 and the first layer 113 are sealed by the insulating layer 102 and the insulating layer 125. The insulating layer 125 functions as a protective layer that prevents impurities such as water from diffusing into the pixel electrode 111 and the first layer 113.

[0223] Furthermore, a material layer 113s, which is formed in the same process as the first layer 113 and has the same structure as the first layer 113, is located on the insulating layer 102. The material layer 113s is separated from the first layer 113 when the layers constituting the first layer 113 are formed, and is provided independently on the insulating layer 102. FIG. 7B shows the material layer 113s remaining inside the groove 173a, inside the groove 173b, and on the region between the two grooves 173a and 173b. The material layer 113s is located between the insulating layer 125 and the insulating layer 102.

[0224] Between light-emitting devices adjacent in the Y direction, the side surfaces of the first layers 113 face each other with an insulating layer 127 interposed therebetween. The insulating layer 127 is located between the light-emitting devices adjacent in the Y direction and is provided so as to fill the region between the two first layers 113. The insulating layer 127 is also provided so as to fill the grooves 173 a and 173 b.

[0225] 7C shows a cross-sectional view of the groove and its vicinity in the display device 200B, in which some elements are omitted for clarity.

[0226] The width L1 shown in FIG. 7C is the width of the groove 173b in the Y direction. The width L1 is preferably two to five times, more preferably two to four times, and even more preferably two to three times the thickness of the first layer 113. This allows the groove 173b to create a step in the first layer 113, allowing the first layer 113 to be formed on the pixel electrode 111. At this time, as shown in FIG. 7B , the first layer 113 is disposed so as to cover the side and top surfaces of the pixel electrode 111. In other words, in a cross-sectional view of the display device 200B, the ends of the first layer 113 are located outside the ends of the pixel electrode 111. In other words, the ends of the first layer 113 cover the ends of the pixel electrode 111. The first layer 113 also has a region in contact with the insulating layer 102. The preferred numerical range for the width of the groove 173a in the Y direction is the same as the width L1.

[0227] 7C is the distance between adjacent grooves 173a and 173b, or in other words, the shortest distance between the ends of adjacent grooves. Also, distance L3 is the distance from the pixel electrode 111 to the groove 173b adjacent to the pixel electrode 111. In other words, distance L3 is the shortest distance from the end of the pixel electrode 111 to the end of the groove 173b adjacent to the pixel electrode 111.

[0228] The interval L2 and the distance L3 may be adjusted appropriately depending on the processing accuracy when using photolithography, the film thickness of the first layer 113, the film thickness of the insulating layer 125, and the like. For example, the interval L2 is set to 200 nm or more and 800 nm or less, preferably 250 nm or more and 700 nm or less, and more preferably 350 nm or more and 600 nm or less. Furthermore, for example, the distance L3 is set to 50 nm or more and 400 nm or less, preferably 50 nm or more and 200 nm or less, and more preferably 50 nm or more and 150 nm or less. Note that the preferred range of the distance from the pixel electrode 111 to the groove 173a adjacent to the pixel electrode 111 is the same as that of the distance L3.

[0229] 7C is the shortest distance between the pixel electrodes 111 of two adjacent light-emitting devices. The distance L4 depends on the width L1, the interval L2, and the distance L3. With the above configuration, the distance L4 is 700 nm or more and 2000 nm or less, preferably 900 nm or more and 1600 nm or less, and more preferably 1000 nm or more and 1400 nm or less.

[0230] FIG. 8A shows a top view of the end of groove 173a, the end of groove 173b, and the vicinity thereof.

[0231] The grooves 173a and 173b preferably extend in the X direction to regions outside the ends of the first layer 113. In Fig. 8A, the distance from the ends of the grooves 173a and 173b to the ends of the first layer 113 is shown as distance L5. This configuration makes it easy to separate the first layer 113 between light-emitting devices adjacent in the Y direction.

[0232] Although not shown in FIG. 8A, it is preferable that the common electrode 115 extend to an area outside the ends of the grooves 173 in the X direction.

[0233] [Display Device 200C] Figure 8B shows a top view of the display device 200C. The display device 200C is an example in which a groove 173_4 is provided between two light-emitting devices that emit light of the same color. In Figure 8B, the groove 173_4 is provided between two pixel electrodes 111a (two light-emitting devices 130a), between two pixel electrodes 111b (two light-emitting devices 130b), and between two pixel electrodes 111c (two light-emitting devices 130c) that are adjacent in the X direction.

[0234] 8B shows an example in which the groove 173_4 does not intersect (is not connected to) other grooves. Note that the groove 173_4 may be configured to intersect (be connected to) one or more of the grooves 173_1a, 173_1b, 173_2a, 173_2b, 173_3a, and 173_3b.

[0235] It is preferable to provide island-shaped first layers 113 for each light-emitting device, not only between sub-pixels exhibiting different colors but also between sub-pixels exhibiting the same color, by discontinuing the first layers 113. This makes it possible to achieve high color reproducibility and high contrast in the display device, and to achieve both high definition and high display quality in the display device.

[0236] [Display Device 200D] Fig. 9A shows a cross-sectional view of display device 200D. Display device 200D differs from display device 200B shown in Fig. 7B in that insulating layer 125 is provided so as to fill the grooves.

[0237] 9A , depending on the film thickness, width L1, distance L3, etc. of the insulating layer 125, the insulating layer 125 is provided so as to fill the grooves. For example, the insulating layer 125 is provided so as to fill the grooves 173_1a, 173_1b, 173_2a, 173_2b, 173_3a, and 173_3b. In this case, the insulating layer 127 is provided on the insulating layer 125 and the insulating layer 102.

[0238] [Display Device 200E] Figure 9B shows a cross-sectional view of display device 200E. Display device 200E differs from display device 200B shown in Figure 7B in that the arrangement of pixel electrodes is different. Figure 9C shows an enlarged view of the pixel electrodes and their vicinity. Note that in Figure 9C, some elements are omitted for clarity.

[0239] In the display device 200E, the pixel electrodes 111 are formed so as to be embedded in the insulating layer 102. In other words, the height of the upper surfaces of the pixel electrodes 111 and the insulating layer 102 is the same or approximately the same. With this configuration, the first layer 113 can be formed on a flat surface.

[0240] In the display device 200E, the first layer 113 is provided on a flat surface, and the first layer 113 does not cover the end of the pixel electrode 111. This prevents the thickness of the first layer 113 from becoming thin, and prevents a short circuit between the upper electrode (common electrode 115) and the lower electrode (pixel electrode 111) of the light-emitting device 130.

[0241] [Display device 200F] Fig. 10A shows a cross-sectional view of display device 200F. Display device 200F differs from display device 200B shown in Fig. 7B in that it has a sidewall insulating layer 104 (also referred to as a sidewall, a sidewall protective layer, an insulating layer, etc.) in contact with the side surface of the pixel electrode. Fig. 10B shows an enlarged view of the pixel electrode and its vicinity.

[0242] In the first layer 113, the portion covering the edge of the pixel electrode is thin, and electric field concentration is likely to occur. By providing the sidewall insulating layer 104, it is possible to suppress current flow from the side surface of the pixel electrode to the first layer 113, which is preferable.

[0243] Furthermore, when a light-emitting device having a tandem structure is used, there is a risk that the light-emitting device may short-circuit if the charge generating layer included in the first layer 113 comes into contact with the side surface of the pixel electrode. By providing the sidewall insulating layer 104, it is possible to suppress short-circuiting of the light-emitting device and realize a highly reliable display device.

[0244] The sidewall insulating layer 104 may have a single-layer structure or a stacked structure of two or more layers. The sidewall insulating layer 104 preferably has an inorganic insulating film. Examples of inorganic insulating films that can be used for the sidewall insulating layer 104 include an insulating oxide film, an insulating nitride film, an insulating oxynitride film, and an insulating nitride oxide film. Specific examples of these inorganic insulating films are as given in the description of the insulating layer 102.

[0245] The method for forming the sidewall insulating layer 104 is not particularly limited. The sidewall insulating layer 104 can be formed by, for example, a sputtering method, a CVD method, a PECVD method, or an ALD method. In particular, the sputtering method, the CVD method, or the PECVD method, each of which has a faster film formation rate than the ALD method, is preferred because it allows the sidewall insulating layer 104 to be formed with a thickness sufficient to ensure insulation with high productivity.

[0246] For example, a silicon oxide film, a silicon nitride film, a silicon oxynitride film, or a silicon nitride oxide film is preferably used as the sidewall insulating layer 104. This enables highly reliable display devices to be manufactured with high productivity.

[0247] Alternatively, an aluminum oxide film may be formed by ALD as the sidewall insulating layer 104. By using ALD, the sidewall insulating layer 104 can be formed with high coverage.

[0248] The cross-sectional views of the display devices shown in Figures 1B, 2A, 3A, 4, 5A, 5C, 7B, 9A, 9B, and 10A illustrate examples in which colored layers 132R, 132G, and 132B are provided on the light-emitting device via a protective layer 131. This configuration can improve the accuracy of alignment between the light-emitting device and the colored layers. Furthermore, by positioning the light-emitting device and the colored layers closer to each other, color mixing can be suppressed and viewing angle characteristics can be improved, which is preferable.

[0249] 11 to 15 are cross-sectional views taken along the dashed line A1-A2 in FIG. 1A.

[0250] 11A , 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 process of forming the colored layers 132R, 132G, and 132B can be increased.

[0251] As shown in Figures 11B, 11C, 12A, and 12B, the display device may be provided with a lens array 133. The lens array 133 may be provided over the light emitting device.

[0252] 11B shows an example in which colored layers 132R, 132G, and 132B are provided on a light-emitting device 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 a light-emitting device is formed, it is possible to improve the accuracy of alignment between the light-emitting device and the colored layers or the lens array.

[0253] 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 insulating layer 134 can be made of a material that can be used for the insulating layer 102. The insulating layer 134 preferably has a planarizing function. Since light emitted from the light-emitting device is extracted through the insulating layer 134, the insulating layer 134 preferably has high transparency to visible light.

[0254] 11B, light emitted from the light-emitting device passes through the colored layer and then passes 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, and the colored layer may be provided on the lens array 133.

[0255] 11C shows an example in which a substrate 120 provided with colored layers 132R, 132G, and 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, and 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.

[0256] FIG. 11C 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.

[0257] 11C , light emitted from the light-emitting device is transmitted through the lens array 133, then through the colored layer, and 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 is transmitted through the colored layer, then through the lens array 133, and extracted to the outside of the display device.

[0258] As shown in FIGS. 12A and 12B, one of the lens array and the colored layer may be provided on the protective layer 131, and the other may be provided on the substrate 120.

[0259] Figure 12A shows an example in which colored layers 132R, 132G, and 132B are provided on a light-emitting device via a protective layer 131, and a substrate 120 on which a lens array 133 is provided is bonded to the colored layers 132R, 132G, and 132B by a resin layer 122.

[0260] Figure 12B shows an example in which a lens array 133 is provided on a light-emitting device via a protective layer 131, and a substrate 120 provided with colored layers 132R, 132G, and 132B is bonded to the lens array 133 and the protective layer 131 by a resin layer 122.

[0261] The convex surface of the lens array 133 may face the substrate 120 side or the light-emitting device side.

[0262] The lens array 133 can be formed using either or both 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 either or both 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.

[0263] It is also preferable that the colored layers of different colors have overlapping portions. The overlapping portions of the colored layers of different colors can function as light-blocking layers, thereby further reducing the reflection of external light.

[0264] Next, a display device having a configuration in which a light-emitting device and a color conversion layer are combined will be described. The following mainly describes an example in which the light-emitting devices 130a, 130b, and 130c emit white or blue light.

[0265] The display device shown in Figure 13A differs from the display device 100A shown in Figure 1B in that it has a color conversion layer 135R between the protective layer 131 and the colored layer 132R, and a color conversion layer 135G between the protective layer 131 and the colored layer 132G.

[0266] The subpixel that emits red light has a light-emitting device 130a and a color conversion layer 135R that converts at least blue light into red light, so that the light emitted from the light-emitting device 130a is extracted as red light to the outside of the display device via the color conversion layer 135R.

[0267] The subpixel that emits red light preferably further includes a coloring layer 132R that transmits red light. Some of the blue light (and green light) emitted by the light-emitting device 130a may be transmitted directly without being converted by the color conversion layer 135R. By extracting the light that has transmitted through the color conversion layer 135R via the coloring layer 132R, light other than red light is absorbed by the coloring layer 132R, and the color purity of the light emitted by the subpixel can be increased.

[0268] The subpixel that emits green light has a light-emitting device 130b and a color conversion layer 135G that converts at least blue light into green light, so that the light emitted from the light-emitting device 130b is extracted as green light to the outside of the display device via the color conversion layer 135G.

[0269] The sub-pixel that emits green light preferably further includes a colored layer 132G that transmits green light, thereby increasing the color purity of the light emitted by the sub-pixel.

[0270] The sub-pixel that emits blue light has at least one light-emitting device 130c that emits blue light, and the light emitted from the light-emitting device 130c is extracted as blue light to the outside of the display device.

[0271] The sub-pixel that emits blue light preferably further includes a colored layer 132B that transmits blue light, thereby increasing the color purity of the light emitted by the sub-pixel.

[0272] The sub-pixels that emit light of each color may each independently have a colored layer or may not have a colored layer.

[0273] When the light-emitting device 130a is configured to emit white light, the color conversion layer 135R preferably converts blue and green light into red light and transmits the red light. By providing such a color conversion layer 135R on the light-emitting device 130a, the blue and green components of the white light can be converted into red light components and extracted to the outside of the display device. Therefore, the red light extraction efficiency can be improved compared to a configuration without the color conversion layer 135R.

[0274] As described above, it is preferable that light transmitted through the color conversion layer 135R is extracted to the outside of the display device via the coloring layer 132R, which transmits red light. In particular, as shown in Fig. 13A, it is preferable that the coloring layer 132R is provided so as to cover the end portion of the color conversion layer 135R. This allows, for example, the coloring layer 132R to absorb blue light and green light that is not color converted by the color conversion layer 135R and that is transmitted through the color conversion layer 135R. This increases the color purity of the light emitted by the subpixel.

[0275] Similarly, when the light-emitting device 130b is configured to emit white light, it is preferable that the color conversion layer 135G converts blue light into green light and transmits the green light. By providing such a color conversion layer 135G overlapping the light-emitting device 130b, the blue light component of the white light can be converted into a green light component and extracted to the outside of the display device. Therefore, the extraction efficiency of green light can be improved compared to a configuration without the color conversion layer 135G.

[0276] It is also preferable that the light transmitted through the color conversion layer 135G is extracted to the outside of the display device via the colored layer 132G that transmits green light, thereby improving the color purity of the light emitted by the sub-pixel.

[0277] Furthermore, when the light-emitting device 130c is configured to emit white light, it is preferable to provide a colored layer 132B that transmits blue light so as to overlap the light-emitting device 130c, thereby enabling the blue light component of the white light to be extracted to the outside of the display device.

[0278] In addition, by applying a microcavity structure, a light-emitting device having an EL layer configured to emit white light may emit light of a specific wavelength, such as red, green, or blue, intensified.

[0279] For example, by applying a configuration that emits white light to the first layer 113 and by applying a microcavity structure, red light can be emitted from the light-emitting device 130a, green light can be emitted from the light-emitting device 130b, and blue light can be emitted from the light-emitting device 130c.

[0280] Here, by applying a microcavity structure, it is possible to enhance and extract light of a desired wavelength in the front direction, but light extracted from an oblique direction will contain white light components.

[0281] Therefore, even in a display device employing a microcavity structure, providing the color conversion layers 135R and 135G is preferable because it can increase the light extraction efficiency. Also, providing the colored layers 132R, 132G, and 132B is preferable because it can increase the color purity of the light emitted by each sub-pixel.

[0282] The first layer 113 can be configured to emit, for example, blue light. For example, the first layer 113 includes a light-emitting material that emits blue light.

[0283] When the light-emitting device 130a is configured to emit blue light, the color conversion layer 135R preferably converts the blue light into red light and transmits the red light. By providing such a color conversion layer 135R on the light-emitting device 130a, the blue light emitted by the first layer 113 can be converted into red light and extracted to the outside of the display device.

[0284] Similarly, when the light-emitting device 130b is configured to emit blue light, the color conversion layer 135G preferably converts the blue light into green light and transmits the green light. By providing such a color conversion layer 135G on the light-emitting device 130b, the blue light emitted by the first layer 113 can be converted into green light and extracted to the outside of the display device.

[0285] That is, even if a structure that emits blue light is applied to the first layer 113, a full-color display device can be realized.

[0286] Even when the first layer 113 is configured to emit blue light, the color purity of the light emitted by each sub-pixel can be increased by using the colored layers 132R, 132G, and 132B, respectively, which is preferable.

[0287] Furthermore, even when the first layer 113 is configured to emit blue light, the microcavity structure may be applied to enhance the blue light emitted by the light-emitting device, or the microcavity structure may not be applied.

[0288] The first layer 113 may also be configured to emit light having a shorter wavelength than blue light, for example, purple light or ultraviolet light. For example, the first layer 113 includes a light-emitting material that emits purple light or ultraviolet light.

[0289] Here, light having a wavelength shorter than that of blue light is, for example, light having a peak wavelength of the emission spectrum of 100 nm or more and less than 400 nm.

[0290] When the light-emitting device 130c is configured to emit light with a shorter wavelength than blue light, it is preferable to provide a color conversion layer that converts the light emitted by the light-emitting device 130c into blue light and transmits the blue light, overlapping the light-emitting device 130c. Also, it is preferable to provide the colored layer 132B at a position that overlaps the light-emitting device 130c via the color conversion layer.

[0291] In this way, a configuration using a color conversion layer or a configuration using a combination of a color conversion layer and a colored layer can also be applied to the sub-pixel that emits blue light.

[0292] If the light emitting devices 130a and 130b are configured to emit light with a wavelength shorter than that of blue light, it is preferable that the color conversion layers 135R and 135G also be able to convert light with a wavelength shorter than that of blue light into red or green light.

[0293] It is preferable to use one or both of a phosphor and quantum dots (QDs) for the color conversion layer. Quantum dots, in particular, have a narrow peak width in the emission spectrum, and can emit light with good color purity. This can improve the display quality of the display device.

[0294] The color conversion layer can be formed by, for example, a droplet ejection method (e.g., inkjet method), a coating method, an imprinting method, or various printing methods (e.g., screen printing, offset printing). Alternatively, a color conversion film such as a quantum dot film may be used.

[0295] When processing the film that will become the color conversion layer, it is preferable to use a photolithography method. For example, a thin film can be formed using a material in which quantum dots are mixed into a photoresist, and then the thin film can be processed using a photolithography method to form island-shaped color conversion layers.

[0296] The material constituting the quantum dots is not particularly limited, and examples thereof include a Group 14 element, a Group 15 element, a Group 16 element, a compound consisting of multiple Group 14 elements, a compound of an element belonging to Groups 4 to 14 and a Group 16 element, a compound of a Group 2 element and a Group 16 element, a compound of a Group 13 element and a Group 15 element, a compound of a Group 13 element and a Group 17 element, a compound of a Group 14 element and a Group 15 element, a compound of a Group 11 element and a Group 17 element, iron oxides, titanium oxides, chalcogenide spinels, and various semiconductor clusters.

[0297] Specifically, cadmium selenide, cadmium sulfide, cadmium telluride, zinc selenide, zinc oxide, zinc sulfide, zinc telluride, mercury sulfide, mercury selenide, mercury telluride, indium arsenide, indium phosphide, gallium arsenide, gallium phosphide, indium nitride, gallium nitride, indium antimonide, gallium antimonide, aluminum phosphide, aluminum arsenide, aluminum antimonide, lead selenide, lead telluride, lead sulfide, indium selenide, terephthalic acid, Indium sulfide, indium sulfide, gallium selenide, arsenic sulfide, arsenic selenide, arsenic telluride, antimony sulfide, antimony selenide, antimony telluride, bismuth sulfide, bismuth selenide, bismuth telluride, silicon, silicon carbide, germanium, tin, selenium, tellurium, boron, carbon, phosphorus, boron nitride, boron phosphide, boron arsenide, aluminum nitride, aluminum sulfide, barium sulfide, barium selenide, barium telluride, calcium sulfide, selenide Calcium, calcium telluride, beryllium sulfide, beryllium selenide, beryllium telluride, magnesium sulfide, magnesium selenide, germanium sulfide, germanium selenide, germanium telluride, tin sulfide, tin selenide, tin telluride, lead oxide, copper fluoride, copper chloride, copper bromide, copper iodide, copper oxide, copper selenide, nickel oxide, cobalt oxide, cobalt sulfide, iron oxide, iron sulfide, manganese oxide, molybdenum sulfide, vanadium oxide, tungsten oxide, tungsten oxide Examples of the quantum dots include talc, titanium oxide, zirconium oxide, silicon nitride, germanium nitride, aluminum oxide, barium titanate, a compound of selenium, zinc, and cadmium, a compound of indium, arsenic, and phosphorus, a compound of cadmium, selenium, and sulfur, a compound of cadmium, selenium, and tellurium, a compound of indium, gallium, and arsenic, a compound of indium, gallium, and selenium, a compound of indium, selenium, and sulfur, a compound of copper, indium, and sulfur, and combinations thereof. Also, so-called alloy-type quantum dots, whose composition is expressed in any ratio, may be used.

[0298] Examples of quantum dot structures include core, core-shell, and core-multishell types. Quantum dots have a high proportion of surface atoms, making them highly reactive and prone to aggregation. To prevent quantum dot aggregation and improve their dispersibility in a dispersion medium, it is preferable that a protective agent be attached to the surface of the quantum dots or that protective groups be provided. This can also reduce reactivity and improve electrical stability.

[0299] Since the band gap of quantum dots increases as their size decreases, their size can be adjusted appropriately to obtain light of the desired wavelength. As the crystal size decreases, the emission of quantum dots shifts toward the blue side, i.e., toward higher energy. Therefore, by changing the size of the quantum dots, the emission wavelength can be adjusted across the wavelength ranges of the ultraviolet, visible, and infrared spectral regions. The size (diameter) of the quantum dots is, for example, 0.5 nm or more and 20 nm or less, preferably 1 nm or more and 10 nm or less. The narrower the size distribution of quantum dots, the narrower the emission spectrum, and the more excellent the color purity of the light emitted. Furthermore, the shape of the quantum dots is not particularly limited and may be spherical, rod-shaped, disc-shaped, or other shapes. Quantum rods, which are rod-shaped quantum dots, have the function of emitting directional light.

[0300] 13A shows an example in which color conversion layers 135R and 135G and coloring layers 132R, 132G, and 132B are provided on a light-emitting device via a protective layer 131. This configuration improves the accuracy of alignment between the light-emitting device and the color conversion layer or coloring layer. Furthermore, by positioning the light-emitting device and the color conversion layer closer together, light that leaks without being color-converted can be suppressed, which is preferable. Furthermore, by positioning the light-emitting device and the coloring layer closer together, color mixing can be suppressed and viewing angle characteristics can be improved, which is preferable.

[0301] 13B differs from the configuration shown in Fig. 13A in that it does not have the colored layer 132B. For example, when a configuration that emits blue light is applied to the first layer 113, the colored layer 132B may not be provided, as shown in Fig. 13B. The blue light emitted by the light-emitting device 130c is extracted to the outside of the display device through the protective layer 131, the resin layer 122, and the substrate 120.

[0302] As shown in FIG. 13C, color conversion layers 135R and 135G may be provided on the light-emitting device via a protective layer 131, and a substrate 120 provided with colored layers 132R, 132G, and 132B may be bonded to the color conversion layers 135R and 135G and the protective layer 131 using a resin layer 122.

[0303] 14A , a substrate 120 provided with color conversion layers 135R, 135G and colored layers 132R, 132G, and 132B may be bonded to a protective layer 131 with a resin layer 122. By providing the color conversion layers 135R, 135G and colored layers 132R, 132G, and 132B on the substrate 120, the temperature of the heat treatment in the process of forming the color conversion layers 135R, 135G and colored layers 132R, 132G, and 132B can be increased. Specifically, one or both of the color conversion layers and the colored layers can be formed at a temperature higher than the heat resistance temperature of the light-emitting device.

[0304] The substrate 120 is provided with colored layers 132R, 132G, and 132B, with a color conversion layer 135R provided at a position overlapping the colored layer 132R, and a color conversion layer 135G provided at a position overlapping the colored layer 132G.

[0305] In this way, the arrangement of the light-emitting device, color conversion layer, and colored layer can be appropriately selected from various configurations in which the color conversion layer is located between the light-emitting device and the colored layer.

[0306] As shown in Figures 14B, 14C, 15A and 15B, the display device may be provided with a lens array 133. The lens array 133 may be provided over the light emitting device.

[0307] 13A , the configuration shown in Fig. 14B includes, on a protective layer 131, a color conversion layer 135R overlapping with the light-emitting device 130a, a colored layer 132R on the color conversion layer 135R, a color conversion layer 135G overlapping with the light-emitting device 130b, a colored layer 132G on the color conversion layer 135G, and a colored layer 132B overlapping with the light-emitting device 130c. Fig. 14B also shows an example in which an insulating layer 134 is provided to cover the colored layers 132R, 132G, and 132B, and a lens array 133 is provided on the insulating layer 134. By forming the color conversion layers 135R and 135G, the colored layers 132R, 132G, and 132B, and the lens array 133 directly on the substrate on which the light-emitting devices are formed, the accuracy of alignment between the light-emitting devices and the color conversion layers, colored layers, or lens array can be improved.

[0308] 14B, light emitted from the light-emitting device passes through the color conversion layer and the colored layer, and then passes 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, and the colored layer may be provided on the lens array 133.

[0309] 14C shows an example in which a substrate 120 provided with colored layers 132R, 132G, and 132B, color conversion layers 135R and 135G, and a lens array 133 is bonded to a protective layer 131 by a resin layer 122. By providing the colored layers 132R, 132G, and 132B, color conversion layers 135R and 135G, and lens array 133 on the substrate 120, the temperature of the heat treatment in the formation process of these layers can be increased.

[0310] Figure 14C shows an example in which colored layers 132R, 132G, and 132B are provided in contact with substrate 120, color conversion layer 135R is provided in contact with colored layer 132R, color conversion layer 135G is provided in contact with colored layer 132G, insulating layer 134 is provided in contact with color conversion layers 135R and 135G and colored layer 132B, and lens array 133 is provided in contact with insulating layer 134.

[0311] In FIG. 14C, light emitted from the light emitting device passes through the lens array 133, then passes through the color conversion layer and the coloring layer, and is extracted to the outside of the display device.

[0312] Alternatively, a lens array 133 may be provided in contact with the substrate 120, an insulating layer 134 may be provided in contact with the lens array 133, and a colored layer and further a color conversion layer may be provided in contact with the insulating layer 134. In this case, light emitted from the light-emitting device passes through the (color conversion layer and) colored layer, then passes through the lens array 133, and is extracted to the outside of the display device.

[0313] 14C, color conversion layers 135R and 135G may be formed on protective layer 131 in contact with it, rather than being formed on substrate 120. In FIG.

[0314] As shown in FIGS. 15A and 15B, one of the lens array and the colored layer may be provided on the protective layer 131, and the other may be provided on the substrate 120.

[0315] Figure 15A shows an example in which color conversion layers 135R, 135G and colored layers 132R, 132G, 132B are provided on a light-emitting device via a protective layer 131, and a substrate 120 on which a lens array 133 is provided is bonded to the colored layers 132R, 132G, 132B by a resin layer 122.

[0316] Figure 15B shows an example in which a lens array 133 is provided on a light-emitting device via a protective layer 131, and a substrate 120 on which colored layers 132R, 132G, 132B and color conversion layers 135R, 135G are provided is bonded to the lens array 133 and the protective layer 131 by a resin layer 122.

[0317] In FIG. 15B, color conversion layers 135R and 135G may be formed on protective layer 131 in contact with it, rather than being formed on substrate 120.

[0318] In this configuration in which the light-emitting device, color conversion layer, and colored layer are arranged such that the color conversion layer is located between the light-emitting device and the colored layer, various methods can be used to arrange the lens array 133. The lens array 133 can be arranged between the light-emitting device and the color conversion layer, between the color conversion layer and the colored layer, or on the substrate 120 side of the colored layer.

[0319] In the display device of one embodiment of the present invention, the EL layer is provided in an island shape for each light-emitting device, which can suppress leakage current between subpixels, thereby preventing unintended light emission due to crosstalk and realizing a display device with extremely high contrast.

[0320] Furthermore, in the manufacturing method of a display device according to one embodiment of the present invention, the EL layer can be formed in an island shape without using a metal mask, so that the display device can have both high resolution and high display quality.

[0321] 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.

[0322] Embodiment 2 In this embodiment, a manufacturing method of a display device according to one embodiment of the present invention will be described with reference to FIG. 16. Note that description of materials and formation methods of elements similar to those described in Embodiment 1 may be omitted. In addition, details of the structure of a light-emitting device will be described in Embodiment 5.

[0323] FIG. 16 shows a cross-sectional view taken along the dashed line A1-A2 in FIG. 1A.

[0324] Thin films (e.g., insulating films, semiconductor films, and conductive films) constituting the display device can be formed using, for example, sputtering, chemical vapor deposition (CVD), vacuum evaporation, pulsed laser deposition (PLD), or atomic layer deposition (ALD). CVD methods include, for example, plasma enhanced chemical vapor deposition (PECVD) and thermal CVD. One type of thermal CVD method is metal organic chemical vapor deposition (MOCVD).

[0325] Furthermore, thin films (e.g., insulating films, semiconductor films, and conductive films) constituting the display device may be formed by a wet film-forming method, such as spin coating, dip coating, spray coating, inkjet printing, dispensing, screen printing (stencil printing), offset printing (lithographic printing), doctor knife, slit coating, roll coating, curtain coating, and knife coating.

[0326] 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 (e.g., hole injection layer, hole transport layer, hole blocking layer, light-emitting layer, electron blocking layer, electron transport layer, electron injection layer, charge generation layer, etc.) can be formed by vapor deposition (e.g., vacuum deposition), coating methods (e.g., dip coating, die coating, bar coating, spin coating, spray coating), or printing methods (e.g., inkjet printing, screen printing, offset printing, flexographic printing (relief printing), gravure printing (intaglio printing), microcontact printing, etc.).

[0327] Furthermore, when processing the thin film that constitutes the display device, for example, a photolithography method can be used. Alternatively, the thin film may be processed by a nanoimprint method, a sandblasting method, a lift-off method, or the like. Furthermore, the island-shaped thin film may be directly formed by a film formation method using a shielding mask such as a metal mask.

[0328] 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.

[0329] In photolithography, the light used for exposure can be, for example, i-line (wavelength 365 nm), g-line (wavelength 436 nm), h-line (wavelength 405 nm), or a mixture of these. Other examples include ultraviolet light, KrF laser light, and ArF laser light. Exposure can also be performed by immersion exposure technology. Extreme ultraviolet (EUV) light or X-rays can also be used as the light used for exposure. An electron beam can also be used instead of the light used for exposure. Extreme ultraviolet light, X-rays, or an electron beam are preferred because they enable extremely fine processing. When exposure is performed by scanning a beam such as an electron beam, a photomask is not required.

[0330] For etching the thin film, for example, dry etching, wet etching, or sandblasting can be used.

[0331] The resist mask can be removed by a dry etching process such as ashing, a wet etching process, a wet etching process after a dry etching process, or a dry etching process after a wet etching process.

[0332] As a typical example of a planarization treatment for a thin film, a polishing treatment such as chemical mechanical polishing (CMP) can be suitably used. Alternatively, a dry etching treatment or a plasma treatment may be used. The polishing treatment, dry etching treatment, and plasma treatment may each be performed multiple times, or these may be performed in combination. When these treatments are performed in combination, the order of the steps is not particularly limited and can be set appropriately according to the unevenness of the surface to be treated.

[0333] To precisely process a thin film to a desired thickness, for example, CMP is used. In this case, the thin film is first polished at a constant processing speed until a portion of the top surface thereof is exposed. Then, the thin film is polished at a slower processing speed until the thin film reaches the desired thickness, thereby enabling highly precise processing.

[0334] Methods for detecting the end point of polishing include, for example, an optical method in which light is irradiated onto the surface of the surface to be treated and changes in the reflected light are detected, a physical method in which changes in the polishing resistance that the processing device receives from the surface to be treated are detected, and a method in which magnetic field lines are applied to the surface to be treated and changes in the magnetic field lines due to the eddy currents that are generated are used.

[0335] After the upper surface of the thin film is exposed, the thickness of the thin film can be controlled with high precision by performing a polishing process under conditions of a slow processing speed while monitoring the thickness of the thin film by an optical method such as a laser interferometer. If necessary, the polishing process may be performed multiple times until the thin film reaches the desired thickness.

[0336] First, various circuits are formed on a substrate to form a layer 101 including a transistor (FIG. 16A).

[0337] The layer 101 including a transistor may have a structure in which a semiconductor circuit including a semiconductor element such as a transistor is provided over a substrate.

[0338] The substrate may be a substrate having heat resistance sufficient to withstand at least a subsequent heat treatment. Preferably, an insulating substrate or a semiconductor substrate is used. Examples of insulating substrates include glass substrates, quartz substrates, sapphire substrates, and ceramic substrates. Examples of semiconductor substrates include single-crystal semiconductor substrates made of silicon, silicon carbide, or the like, polycrystalline semiconductor substrates, compound semiconductor substrates made of silicon germanium, gallium nitride, gallium arsenide, indium arsenide, indium gallium arsenide, indium phosphide, and semiconductor substrates such as SOI (Silicon On Insulator) substrates.

[0339] Examples of semiconductor circuits formed on the substrate include pixel circuits, gate line driving circuits (gate drivers), and source line driving circuits (source drivers). In addition to the above, one or both of an arithmetic circuit and a memory circuit may be formed.

[0340] Next, an insulating film that will become the insulating layer 102 is formed. Next, an opening is formed in the insulating film at a position where the plug 103 will be formed, reaching the transistor-containing layer 101. The opening preferably reaches an electrode or wiring provided in the transistor-containing layer 101. Next, a conductive film is formed to fill the opening, and then planarization treatment is performed to expose the top surface of the insulating film. This allows the plug 103 to be formed embedded in the insulating layer 102 ( FIG. 16A ).

[0341] Next, a conductive film that will become a pixel electrode is formed on the insulating layer 102 and the plug 103, a resist mask is formed by photolithography, and unnecessary portions of the conductive film are removed by etching. This allows the pixel electrodes 111a, 111b, and 111c to be formed ( FIG. 16A ). The conductive film that will become the pixel electrodes can be formed by, for example, sputtering or vacuum deposition. The conductive film can be processed by wet etching or dry etching. The conductive film is preferably processed by anisotropic etching. The pixel electrodes 111a, 111b, and 111c are each formed to overlap the plug 103 and are electrically connected to the plug 103.

[0342] Next, the pixel electrodes 111a, 111b, and 111c and the resist mask are used to etch a portion of the insulating layer 102, thereby forming a groove 175 in the insulating layer 102 (FIG. 16A). This allows the groove 175 shown in FIG. 1A to be formed. Thereafter, the resist mask is removed.

[0343] By forming the grooves 175 in the insulating layer 102, it becomes easy to partially thin the first layer 113 to be formed later, or to separate the first layer 113 into individual light-emitting devices.

[0344] An isotropic etching method can be used to form the groove 175. For example, a wet etching process or an isotropic plasma etching process can be used. In particular, when an inorganic insulating film is used as the insulating layer 102, it is preferable to use a wet etching process. Furthermore, when an organic insulating film is used as the insulating layer 102, it is preferable to use an isotropic dry etching process. This makes it possible to form the groove 175, a part of which is located below the pixel electrode.

[0345] Note that grooves may be formed in the insulating layer 102 before the pixel electrodes 111a, 111b, and 111c are formed (specifically, before the conductive film that will become the pixel electrodes is formed). In this case, the grooves can be formed using a mask different from the resist mask used to form the pixel electrodes, thereby broadening the options for the top surface layout of the grooves. For example, the grooves shown in FIG. 6A, FIG. 7A, or FIG. 8B are preferably formed before the conductive film that will become the pixel electrodes is formed.

[0346] Next, the first layer 113 is formed on the pixel electrodes 111a, 111b, and 111c (FIG. 16B). For example, when a blue-emitting light-emitting device is fabricated, the first layer 113 includes a light-emitting material that emits blue light. Also, for example, when a white-emitting light-emitting device is fabricated, the first layer 113 includes a light-emitting material that emits blue light and a light-emitting material that emits light with a longer wavelength than the blue light. FIG. 16B shows an example in which an island-shaped first layer 113 is provided for each light-emitting device. That is, an island-shaped first layer 113 is provided on each of the pixel electrodes 111a, 111b, and 111c.

[0347] In the region between the pixel electrodes 111a and 111b, a material layer 113s is provided on the insulating layer 102 (specifically, inside the groove 175). Similarly, in the region between the pixel electrodes 111b and 111c and the region between the pixel electrodes 111c and 111a, a material layer 113s is also provided on the insulating layer 102. The material layer 113s is formed in the same process as the first layer 113 and has the same configuration.

[0348] In this way, the groove 175 causes a step in the film that will become the first layer 113 .

[0349] The first layer 113 can be formed by, for example, a vapor deposition method, specifically a vacuum deposition method. Alternatively, the first layer 113 may be formed by a transfer method, a printing method, an inkjet method, or a coating method.

[0350] Furthermore, if each process performed after forming the first layer 113 is performed at a temperature higher than the heat resistance temperature of the first layer 113, deterioration of the first layer 113 may progress, and the light-emitting efficiency and reliability of the light-emitting device may decrease.

[0351] Therefore, the heat resistance temperature of the compounds contained in the light-emitting device is preferably 100°C or higher and 180°C or lower, more preferably 120°C or higher and 180°C or lower, and more preferably 140°C or higher and 180°C or lower.

[0352] Examples of heat resistance temperature indicators include the glass transition point (Tg), softening point, melting point, thermal decomposition temperature, and 5% weight loss temperature. For example, the glass transition point of the material contained in each layer constituting the first layer 113 can be used as an indicator of the heat resistance temperature. Furthermore, when the layer is a mixed layer made of multiple materials, the glass transition point of the material contained in the largest amount can be used. Alternatively, the lowest temperature among the glass transition points of the multiple materials may be used.

[0353] In particular, it is preferable to increase the heat resistance temperature of the functional layer provided on the light-emitting layer. Furthermore, it is even more preferable to increase the heat resistance temperature of the functional layer provided on and in contact with the light-emitting layer. The high heat resistance of the functional layer makes it possible to effectively protect the light-emitting layer and reduce damage to the light-emitting layer.

[0354] In particular, it is preferable to increase the heat resistance temperature of the light-emitting layer, which can prevent the light-emitting layer from being damaged by heating, resulting in a decrease in light-emitting efficiency and a shortened lifespan.

[0355] By increasing the heat resistance temperature of the light-emitting device, the reliability of the light-emitting device can be improved. In addition, the temperature range in the manufacturing process of the display device can be widened, which leads to improvement in manufacturing yield and reliability.

[0356] Next, an insulating film 125A, which will later become the insulating layer 125, is formed to cover the pixel electrodes 111a, 111b, 111c, the first layer 113, and the material layer 113s, and an insulating film 127A is formed on the insulating film 125A (FIG. 16C).

[0357] The insulating films 125A and 127A are preferably formed by a formation method that causes less damage to the first layer 113. In particular, since the insulating film 125A is formed in contact with the top surface and side surfaces of the first layer 113, it is preferably formed by a formation method that causes less damage to the first layer 113 than the insulating film 127A.

[0358] The insulating films 125A and 127A are formed at a temperature lower than the heat-resistant temperature of the first layer 113. By increasing the substrate temperature during film formation, the insulating film 125A can have a low impurity concentration and a high barrier property against water and / or oxygen, even if it is thin.

[0359] The substrate temperature when forming the insulating film 125A and the insulating film 127A is preferably 60°C or higher, 80°C or higher, 100°C or higher, or 120°C or higher, and 200°C or lower, 180°C or lower, 160°C or lower, 150°C or lower, or 140°C or lower.

[0360] 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 within the above substrate temperature range.

[0361] The insulating film 125A is preferably formed by, for example, an ALD method. The ALD method is preferable because it can reduce film formation damage and form a film with high coverage. The insulating film 125A is preferably formed as an aluminum oxide film by, for example, an ALD method.

[0362] The insulating film 125A needs to be formed with good coverage in the grooves 175 provided in the insulating layer 102. Film formation by the ALD method allows atomic layers to be deposited one by one on the bottom and side surfaces of the grooves 175, so the insulating film 125A can be formed with good coverage in the grooves 175. In addition, damage caused by film formation can be reduced.

[0363] Alternatively, the insulating film 125A may be formed by a sputtering method, a CVD method, or a PECVD method, which have a faster film formation rate than an ALD method. This enables a highly reliable display device to be manufactured with high productivity.

[0364] The insulating film 127A is preferably formed by the wet film formation method described above. The insulating film 127A is preferably formed by, for example, spin coating using a photosensitive resin, more specifically, using a photosensitive resin composition containing an acrylic resin.

[0365] Furthermore, heat treatment (also referred to as pre-baking) is preferably performed after the insulating film 127A is formed. The heat treatment is performed at a temperature lower than the upper temperature limit of the first layer 113. The substrate temperature during the heat treatment is preferably 50° C. to 200° C., more preferably 60° C. to 150° C., and still more preferably 70° C. to 130° C. This allows the solvent contained in the insulating film 127A to be removed.

[0366] Subsequently, exposure is performed to expose a part of the insulating film 127A to visible light or ultraviolet light.

[0367] The light used for exposure preferably contains i-line (wavelength 365 nm), and may contain one or both of g-line (wavelength 436 nm) and h-line (wavelength 405 nm).

[0368] Subsequently, development is performed to remove the exposed areas of the insulating film 127A, thereby forming the insulating layer 127 (FIG. 16D). An alkaline solution is preferably used as the developer, and for example, an aqueous solution of tetramethylammonium hydroxide (TMAH) can be used.

[0369] The developing method is not particularly limited, and for example, a dip method, a spin method, a paddle method, or a vibration method can be used. Note that, in order to stabilize the etching rate, it is preferable to apply a method in which new liquid is constantly supplied. Alternatively, it is preferable to apply a method in which the supply and retention (development) of liquid are repeated (also called a step paddle method). The step paddle method is preferable because it can reduce the amount of liquid consumed and stabilize the etching rate compared to a method in which new liquid is constantly supplied.

[0370] After the insulating layer 127 is formed, heat treatment (also referred to as post-baking) is preferably performed. The heat treatment is performed at a temperature lower than the upper temperature limit of the first layer 113. The substrate temperature during the heat treatment is preferably 50° C. or higher and 200° C. or lower, more preferably 60° C. or higher and 150° C. or lower, and even more preferably 70° C. or higher and 130° C. or lower. The heating atmosphere may be an air atmosphere or an inert gas atmosphere. The heating atmosphere may be an atmospheric pressure atmosphere or a reduced-pressure atmosphere. A reduced-pressure atmosphere is preferable because drying can be performed at a lower temperature. The heat treatment in this step is preferably performed at a higher substrate temperature than the heat treatment (pre-baking) performed after the formation of the insulating film 127A.

[0371] Subsequently, an etching process is performed using the insulating layer 127 as a mask to remove a portion of the insulating film 125A, thereby forming the insulating layer 125 having an opening, and exposing the upper surface of the first layer 113 (FIG. 16D).

[0372] The etching treatment is preferably performed by wet etching, since the damage to the first layer 113 can be reduced by using wet etching compared to when dry etching is used.

[0373] When using a wet etching method, it is preferable to use a chemical solution using, for example, a developer, a tetramethylammonium hydroxide (TMAH) aqueous solution, dilute hydrofluoric acid, oxalic acid, phosphoric acid, acetic acid, nitric acid, or a mixture thereof. Furthermore, when using a wet etching method, a mixed acid chemical solution containing water, phosphoric acid, dilute hydrofluoric acid, and nitric acid may also be used. The chemical solution used in the wet etching process may be alkaline or acidic.

[0374] Furthermore, after a portion of the first layer 113 is exposed, heat treatment may be further performed. This heat treatment can remove, for example, water contained in the first layer 113 and water adsorbed to the surface of the first layer 113. For example, 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. to 200° C., preferably 60° C. to 150° C., and more preferably 70° C. to 130° C. A reduced-pressure atmosphere is preferable because dehydration can be achieved at a lower temperature. However, it is preferable to appropriately set the temperature range of the heat treatment, taking into account the heat resistance temperature of the first layer 113. Note that, in consideration of the heat resistance temperature of the first layer 113, a temperature of 70° C. to 130° C. is particularly preferable within the above temperature range.

[0375] Next, a common layer 114 is formed on the first layer 113 and the insulating layer 127, a common electrode 115 is formed on the common layer 114, and a protective layer 131 is formed on the common electrode 115 ( FIG. 16E ). When a configuration having a colored layer on the protective layer 131 (e.g., FIG. 1B ) is applied, colored layers 132R, 132G, and 132B are then provided on the protective layer 131. Then, a substrate 120 is bonded to the protective layer 131 using a resin layer 122, thereby fabricating a display device ( FIG. 1B ). When a configuration having a colored layer on the substrate 120 (e.g., FIG. 11A ) is applied, colored layers 132R, 132G, and 132B are provided on the substrate 120 in advance, and the substrate 120 is then bonded to fabricate a display device.

[0376] The common layer 114 can be formed by, for example, a vapor deposition method (including a vacuum deposition method), a transfer method, a printing method, an inkjet method, or a coating method.

[0377] 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.

[0378] Examples of methods for forming the protective layer 131 include vacuum deposition, sputtering, CVD, and ALD.

[0379] As described above, in the manufacturing method of the display device of this embodiment, the island-shaped first layer 113 is formed without using a fine metal mask, and therefore, the island-shaped first layer 113 can be formed to a uniform thickness. This makes it possible to realize a high-definition display device or a display device with a high aperture ratio. Furthermore, even if the definition or aperture ratio is high and the distance between subpixels is extremely short, the first layers 113 in adjacent subpixels can be prevented from contacting each other. Therefore, leakage current between subpixels can be suppressed. This makes it possible to prevent unintended light emission due to crosstalk, and realize a display device with extremely high contrast.

[0380] Furthermore, in the manufacturing method of the display device of this embodiment mode, sub-pixels of three colors can be formed separately by forming only one type of EL layer. Therefore, the number of manufacturing steps is reduced, and the display device can be manufactured with high yield.

[0381] In addition, in the manufacturing method of the display device of this embodiment, the light-emitting device can be formed on the insulating layer 102 whose upper surface is planarized. Furthermore, since the lower electrode (pixel electrode) of the light-emitting device can be electrically connected to the pixel circuit or the like provided in the layer 101 including the transistor through the plug 103, it is possible to form an extremely fine pixel, and it is possible to realize a display device with extremely high resolution. Furthermore, since the light-emitting device can be arranged overlapping the pixel circuit or the driver circuit, it is possible to realize a display device with a high aperture ratio (effective light-emitting area ratio).

[0382] Furthermore, by providing the insulating layer 127 having a tapered end between adjacent island-shaped first layers 113, it is possible to prevent a step from being formed during the formation of the common electrode 115 and to prevent a locally thin portion from being formed in the common electrode 115. This can prevent a connection failure caused by a disconnected portion in the common layer 114 and the common electrode 115 and an increase in electrical resistance caused by a locally thin portion in the common layer 114 and the common electrode 115. Therefore, the display device of one embodiment of the present invention can achieve both high resolution and high display quality.

[0383] This embodiment mode can be combined with other embodiment modes as appropriate.

[0384] Embodiment 3 In this embodiment, a display device of one embodiment of the present invention will be described with reference to FIGS.

[0385] [Pixel Layout] In this embodiment, pixel layouts different from that shown in FIG. 1A will be mainly described. 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.

[0386] The top surface shape of the sub-pixels shown in the drawings in this embodiment corresponds to the top surface shape of the light-emitting region. Examples of the top surface shape of the sub-pixels include polygons such as triangles, quadrilaterals (including rectangles, rhombuses, and squares), and pentagons, as well as polygons with rounded corners, ellipses, and circles.

[0387] Furthermore, the circuit layout constituting the subpixel is not limited to the range of the subpixel shown in the figure, and the circuit components may be arranged outside of it. The arrangement of the circuit and the arrangement of the light-emitting devices do not necessarily have to be the same, and different arrangement methods may also be used. For example, the arrangement of the circuit may be a stripe arrangement, and the arrangement of the light-emitting devices may be an S-stripe arrangement.

[0388] An S-stripe arrangement is applied to the pixel 110 shown in Fig. 17A. The pixel 110 shown in Fig. 17A is composed of three sub-pixels, 110a, 110b, and 110c.

[0389] The pixel 110 shown in Figure 17B includes a subpixel 110a having a substantially triangular or trapezoidal top surface shape with rounded corners, a subpixel 110b having a substantially triangular or trapezoidal top surface shape with rounded corners, and a subpixel 110c having a substantially rectangular or hexagonal top surface shape with rounded corners. Furthermore, the subpixel 110b has a larger light-emitting area than the subpixel 110a. 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 of the subpixel can be.

[0390] The Pentile arrangement is applied to the pixels 124a and 124b shown in Fig. 17C. Fig. 17C shows an example in which a pixel 124a having sub-pixels 110a and 110b and a pixel 124b having sub-pixels 110b and 110c are arranged alternately.

[0391] 17D to 17F are arranged in a delta configuration. 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). 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).

[0392] Figure 17D is an example in which each sub-pixel has an approximately rectangular top surface shape with rounded corners, Figure 17E is an example in which each sub-pixel has a circular top surface shape, and Figure 17F is an example in which each sub-pixel has an approximately hexagonal top surface shape with rounded corners.

[0393] In Figure 17F, each subpixel is arranged inside a closely packed hexagonal region. Each subpixel is arranged so that it is surrounded by six other subpixels when focusing on one subpixel. Furthermore, subpixels that emit light of the same color are arranged so that they are not adjacent to each other. For example, when focusing on subpixel 110a, three subpixels 110b and three subpixels 110c are arranged alternately so as to surround it.

[0394] 17G 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 sides of two subpixels aligned in the column direction (for example, subpixels 110a and 110b, or subpixels 110b and 110c) are misaligned.

[0395] 17A to 17G, it is preferable that the subpixel 110a be the subpixel R that emits red light, the subpixel 110b be the subpixel G that emits green light, and the subpixel 110c be the subpixel B that emits blue light. Note that the configuration of the subpixels is not limited to this, and the colors that the subpixels emit and their order of arrangement can be determined appropriately. For example, the subpixel 110b may be the subpixel R that emits red light, and the subpixel 110a may be the subpixel G that emits green light.

[0396] In photolithography, the finer the pattern to be processed, the more significant the influence of light diffraction becomes. This reduces the fidelity when transferring a photomask pattern by exposure, making it difficult to process the resist mask into a desired shape. Therefore, even if the photomask pattern is rectangular, a pattern with rounded corners is likely to be formed. Therefore, the top surface shape of the pixel electrode may be, for example, a polygon with rounded corners, an ellipse, or a circle. In a display device according to one embodiment of the present invention, the top surface shape of the EL layer and further the light-emitting device may be, for example, a polygon with rounded corners, an ellipse, or a circle, depending on the top surface shape of the pixel electrode.

[0397] In order to make the top surface shape of the pixel electrode into a desired shape, a technique for correcting the 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.

[0398] As shown in Figures 18A to 18I, a pixel can be configured to have four types of sub-pixels.

[0399] The pixels 110 shown in FIGS. 18A to 18C are arranged in a stripe pattern.

[0400] Figure 18A shows an example in which each subpixel has a rectangular top surface shape, Figure 18B shows an example in which each subpixel has a top surface shape that is a combination of two semicircles and a rectangle, and Figure 18C shows an example in which each subpixel has an elliptical top surface shape.

[0401] The pixels 110 shown in FIGS. 18D to 18F are arranged in a matrix.

[0402] Figure 18D is an example in which each sub-pixel has a square top surface shape, Figure 18E is an example in which each sub-pixel has an approximately square top surface shape with rounded corners, and Figure 18F is an example in which each sub-pixel has a circular top surface shape.

[0403] 18G and 18H show an example in which one pixel 110 is configured in two rows and three columns.

[0404] 18G 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.

[0405] The pixel 110 shown in FIG. 18H 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. 18H, 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.

[0406] FIG. 18I shows an example in which one pixel 110 is configured in three rows and two columns.

[0407] 18I has subpixel 110a in the top row (first row), subpixel 110b in the middle row (second row), subpixel 110c across the first and second rows, and one subpixel (subpixel 110d) in the bottom row (third row). In other words, pixel 110 has subpixels 110a and 110b in the left column (first column), subpixel 110c in the right column (second column), and subpixel 110d across these two columns.

[0408] The pixel 110 shown in FIGS. 18A to 18I is composed of four sub-pixels 110a, 110b, 110c, and 110d.

[0409] The sub-pixels 110a, 110b, 110c, and 110d may each have a light-emitting device that emits light of a different color, such as sub-pixels of four colors R, G, B, and white (W), sub-pixels of four colors R, G, B, and Y, or sub-pixels of R, G, B, and infrared (IR).

[0410] 18A to 18I , it is preferable that, for example, the subpixel 110a be the subpixel R that emits red light, the subpixel 110b be the subpixel G that emits green light, the subpixel 110c be the subpixel B that emits blue light, and the subpixel 110d be any one of the subpixels W that emit white light, Y that emit yellow light, and IR that emit near-infrared light. With such a configuration, the pixel 110 shown in FIGS. 18G and 18H has a stripe layout of R, G, and B, thereby improving display quality. Furthermore, the pixel 110 shown in FIG. 18I has a so-called S-stripe layout of R, G, and B, thereby improving display quality.

[0411] 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.

[0412] This embodiment mode can be combined with other embodiment modes as appropriate.

[0413] Embodiment 4 In this embodiment, a display device of one embodiment of the present invention will be described with reference to FIGS.

[0414] The display device of the present embodiment can be a high-definition display device, and can therefore be used, for example, as a display unit for a wristwatch-type or bracelet-type information terminal (wearable device), as well as a display unit for a wearable device that can be worn on the head, such as a head-mounted display (HMD) for VR, or a glasses-type AR device.

[0415] 19A shows a perspective view of a display module 280. The display module 280 includes a display device 300A and an FPC 290. Note that the display device included in the display module 280 is not limited to the display device 300A, and may be any of display devices 300B to 300F described later.

[0416] 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.

[0417] 19B 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.

[0418] 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. 19B. The pixel 284a has a sub-pixel 11R that emits red light, a sub-pixel 11G that emits green light, and a sub-pixel 11B that emits blue light.

[0419] The pixel circuit section 283 has a plurality of pixel circuits 283a arranged periodically.

[0420] 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 can be configured to have three circuits that control the light emission of one light-emitting device. For example, the pixel circuit 283a can be configured to have at least one selection transistor, one current control transistor (drive transistor), and a capacitor 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.

[0421] The circuit portion 282 includes a circuit for driving each pixel circuit 283a of the pixel circuit portion 283. For example, it is preferable that the circuit portion 282 includes one or both of a gate line driver circuit and a source line driver circuit. In addition, the circuit portion 282 may include one or more of an arithmetic circuit, a memory circuit, and a power supply circuit. Furthermore, a transistor provided in the circuit portion 282 may constitute a part of the pixel circuit 283a. In other words, the pixel circuit 283a may be composed of a transistor included in the pixel circuit portion 283 and a transistor included in the circuit portion 282.

[0422] The FPC 290 functions as wiring for supplying a video signal and a power supply potential from the outside to the circuit portion 282. An IC may be mounted on the FPC 290.

[0423] 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.

[0424] Because such a display module 280 has extremely high resolution, it can be suitably used in VR devices such as HMDs or eyeglass-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 displays. For example, it can be suitably used in the display unit of a wearable electronic device such as a wristwatch.

[0425] Display Device 300A The display device 300A shown in FIG. 20 includes a substrate 301, a light-emitting device 130a, a light-emitting device 130b, a light-emitting device 130c, a colored layer 132R, a colored layer 132G, a colored layer 132B, a capacitor 240, and a transistor 310.

[0426] 19B includes a light-emitting device 130a and a colored layer 132R, a sub-pixel 11G includes a light-emitting device 130b and a colored layer 132G, and a sub-pixel 11B includes a light-emitting device 130c and a colored layer 132B. In the sub-pixel 11R, light emitted from the light-emitting device 130a is extracted as red light (R) to the outside of the display device 300A via the colored layer 132R. Similarly, in the sub-pixel 11G, light emitted from the light-emitting device 130b is extracted as green light (G) to the outside of the display device 300A via the colored layer 132G. In the sub-pixel 11B, light emitted from the light-emitting device 130c is extracted as blue light (B) to the outside of the display device 300A via the colored layer 132B.

[0427] 19A and 19B. The stacked structure from the substrate 301 to the insulating layer 255 corresponds to the layer 101 including the transistor in Embodiment 1.

[0428] 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.

[0429] Furthermore, an element isolation layer 315 is provided between two adjacent transistors 310 so as to be embedded in the substrate 301 .

[0430] In addition, an insulating layer 261 is provided to cover the transistor 310 , and a capacitor 240 is provided over the insulating layer 261 .

[0431] 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.

[0432] 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.

[0433] Note that at least one of the conductive layer levels included in the layer 101 including the transistor preferably includes a conductive layer surrounding the outside of the display portion 281 (or the pixel portion 284). The conductive layer can also be called a guard ring. By providing the conductive layer, it is possible to prevent elements such as transistors and light-emitting devices from being damaged by a high voltage applied to these elements due to charging caused by electrostatic discharge (ESD) or a process using plasma.

[0434] An insulating layer 255 is provided to cover the capacitor 240. An insulating layer 102 is provided on the insulating layer 255, and the light-emitting devices 130a, 130b, and 130c are provided on the insulating layer 102. Figure 20 shows an example in which the insulating layer 102, the light-emitting devices 130a, 130b, and 130c have the same structure as the structure shown in Figure 1B.

[0435] The pixel electrode 111a, the pixel electrode 111b, and the pixel electrode 111c are electrically connected to one of the source and drain of the transistor 310 via a plug 256 embedded in the insulating layer 243, the insulating layer 255, and the insulating layer 102, a conductive layer 241 embedded in the insulating layer 254, and a plug 271 embedded in the insulating layer 261. The height of the surface of the insulating layer 102 that contacts the pixel electrode and the height of the surface of the plug 256 that contacts the pixel electrode are the same or approximately the same. Various conductive materials can be used for the plug.

[0436] Furthermore, a protective layer 131 is provided on the light-emitting devices 130a, 130b, and 130c. On the protective layer 131, a colored layer 132R is provided at a position overlapping with the light-emitting device 130a, a colored layer 132G is provided at a position overlapping with the light-emitting device 130b, and a colored layer 132B is provided at a position overlapping with the light-emitting device 130c. A substrate 120 is bonded to the colored layers 132R, 132G, and 132B by a resin layer 122. For details of the components from the light-emitting devices to the substrate 120, refer to Embodiment 1. The substrate 120 corresponds to the substrate 292 in FIG. 19A .

[0437] 21 has a configuration in which a transistor 310A and a transistor 310B, each having a channel formed in a semiconductor substrate, are stacked. Note that in the following description of the display device, descriptions of parts that are the same as those of the display device described above may be omitted.

[0438] The display device 300B 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.

[0439] 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. As the insulating layers 345 and 346, an inorganic insulating film that can be used for the protective layer 131 or the insulating layer 332 can be used.

[0440] 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.

[0441] 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.

[0442] 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.

[0443] 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.

[0444] 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 above elements (titanium nitride film, molybdenum nitride film, tungsten nitride film) 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).

[0445] [Display Device 300C] A display device 300C shown in FIG. 22 has a configuration in which a conductive layer 341 and a conductive layer 342 are joined via a bump 347.

[0446] 22 , 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 at least one of gold (Au), nickel (Ni), indium (In), and tin (Sn), for example. 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.

[0447] [Display Device 300D] A display device 300D shown in FIG. 23 differs from the display device 300A mainly in the configuration of the transistors.

[0448] 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.

[0449] 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 .

[0450] 19A and 19B . The stacked structure from the substrate 331 to the insulating layer 255 corresponds to the layer 101 including the transistor in Embodiment 1. The substrate 331 can be an insulating substrate or a semiconductor substrate.

[0451] 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.

[0452] 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.

[0453] 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 properties. A pair of conductive layers 325 is provided over and in contact with the semiconductor layer 321 and functions as a source electrode and a drain electrode.

[0454] 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 into 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.

[0455] 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.

[0456] 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.

[0457] 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.

[0458] 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.

[0459] Note that the structure of the transistor included in the display device of this embodiment is not particularly limited. For example, a planar transistor, a staggered transistor, an inverted staggered transistor, or the like can be used. Furthermore, either a top-gate transistor or a bottom-gate transistor structure may be used. Alternatively, gates may be provided above and below a semiconductor layer in which a channel is formed.

[0460] The transistor 320 has 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 transistor may be driven by supplying the same signal to them. 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.

[0461] The crystallinity of a semiconductor material used in a transistor is not particularly limited, and any of an amorphous semiconductor, a single crystalline semiconductor, and a semiconductor having crystallinity other than 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 crystalline semiconductor or a crystalline semiconductor is preferable because it can suppress deterioration of transistor characteristics.

[0462] A semiconductor layer of the transistor preferably contains a metal oxide. That is, a transistor (OS transistor) using a metal oxide in a channel formation region is preferably used in the display device of this embodiment.

[0463] Examples of metal oxides that can be used in the semiconductor layer include indium oxide, gallium oxide, and zinc oxide. The metal oxide used in the semiconductor layer preferably contains two or three elements selected from indium, element M, and zinc. The element 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, cobalt, and magnesium. In particular, the element M is preferably one or more elements selected from aluminum, gallium, yttrium, and tin.

[0464] In particular, as the metal oxide used for the semiconductor layer, it is preferable to use an oxide containing indium (In), gallium (Ga), and zinc (Zn) (also referred to as IGZO). Alternatively, it is preferable to use an oxide containing indium, tin, and zinc (also referred to as ITZO (registered trademark)). 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).

[0465] When the metal oxide used in the semiconductor layer is an In-M-Zn oxide, the atomic ratio of In in the In-M-Zn oxide is preferably equal to or greater than the atomic ratio of M. Examples of atomic ratios of metal elements in such an In-M-Zn oxide include a composition of In:M:Zn=1:1:1 or thereabouts, In:M:Zn=1:1:1 or thereabouts, In:M:Zn=1:1:1.2 or thereabouts, In:M:Zn=1:3:2 or thereabouts, In:M:Zn=1:3:4 or thereabouts, In:M:Zn=2:1:3 or thereabouts, In:M:Zn=3:1:2 or thereabouts, In:M:Zn=4:2: Examples of such compositions include a composition of In:M:Zn=4:2:4.1 or a composition of In:M:Zn=5:1:3 or a composition of In:M:Zn=5:1:6 or a composition of In:M:Zn=5:1:7 or a composition of In:M:Zn=5:1:8 or a composition of In:M:Zn=6:1:6 or a composition of In:M:Zn=5:2:5 or a composition of In:M:Zn=5:2:5. Note that the term "composition of a similar ratio" includes a range of ±30% of the desired atomic ratio.

[0466] 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.

[0467] The semiconductor layer may also have two or more metal oxide layers with different compositions. For example, a stacked structure of a first metal oxide layer having an In:M:Zn=1:3:4 (atomic ratio) or a composition similar thereto and a second metal oxide layer having an In:M:Zn=1:1:1 (atomic ratio) or a composition similar thereto provided on the first metal oxide layer is preferably used. Gallium or aluminum is particularly preferably used as the element M.

[0468] Alternatively, for example, a stacked structure of any one selected from indium oxide, indium gallium oxide, and IGZO and any one selected from IAZO, IAGZO, and ITZO (registered trademark) may be used.

[0469] Examples of crystalline oxide semiconductors include c-axis-aligned crystalline (CAAC)-OS and nanocrystalline (nc)-OS.

[0470] Alternatively, a transistor using silicon for a channel formation region (Si transistor) may be used. Examples of silicon include single crystal silicon, polycrystalline silicon, low temperature polysilicon (LTPS), and amorphous silicon.

[0471] By using Si 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, simplifying the external circuits mounted on the display device and reducing component and mounting costs.

[0472] Furthermore, 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 (also referred to as off-state current) in an off state, 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.

[0473] 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.

[0474] 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.

[0475] 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.

[0476] As described above, by using an OS transistor for a driving transistor included in a pixel circuit, it is possible to achieve, for example, "suppression of black floating," "increase in light emission luminance," "multiple gradations," and "suppression of variations in light-emitting devices."

[0477] [Display Device 300E] A display device 300E illustrated in FIG. 24 has a stacked structure of a transistor 320A and a transistor 320B each including an oxide semiconductor as a semiconductor in which a channel is formed.

[0478] The transistor 320A, the transistor 320B, and the surrounding configurations thereof can be referred to the display device 300D.

[0479] Although two transistors including an oxide semiconductor are stacked here, the present invention is not limited to this structure, and for example, three or more transistors may be stacked.

[0480] [Display Device 300F] A display device 300F illustrated in FIG. 25 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.

[0481] 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.

[0482] 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.

[0483] Note that although one transistor including an oxide semiconductor is stacked over the transistor 310 here, the present invention is not limited to this. For example, two or more transistors may be stacked over the transistor 310 (for example, the transistor 320A shown in FIG. 24 is stacked over the transistor 310, and the transistor 320B is stacked over the transistor 320A).

[0484] 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.

[0485] This embodiment mode can be combined with other embodiment modes as appropriate.

[0486] Embodiment 5 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.

[0487] 26A, the light-emitting device has an EL layer 763 between a pair of electrodes (a lower electrode 761 and an upper electrode 762). The EL layer 763 can be composed of multiple layers, such as a layer 780, a light-emitting layer 771, and a layer 790.

[0488] The light-emitting layer 771 contains at least a light-emitting substance (also referred to as a light-emitting material).

[0489] When the lower electrode 761 is an anode and the upper electrode 762 is a cathode, the layer 780 includes one or more of a layer containing a substance with high hole-injecting properties (hole-injecting layer), a layer containing a substance with high hole-transporting properties (hole-transporting layer), and a layer containing a substance with high electron-blocking properties (electron-blocking layer). The layer 790 also includes one or more of a layer containing a substance with high electron-injecting properties (electron-injecting layer), a layer containing a substance with high electron-transporting properties (electron-transporting layer), and a layer containing a substance with high hole-blocking properties (hole-blocking layer). When the lower electrode 761 is a cathode and the upper electrode 762 is an anode, the layers 780 and 790 have the opposite structures to those described above.

[0490] A structure including the layer 780, the light-emitting layer 771, and the layer 790 provided between a pair of electrodes can function as a single light-emitting unit, and the structure of FIG. 26A is referred to as a single structure in this specification.

[0491] 26B shows a modified example of the EL layer 763 included in the light-emitting device shown in Fig. 26A. Specifically, the light-emitting device shown in Fig. 26B includes a layer 781 on a lower electrode 761, a layer 782 on the layer 781, a light-emitting layer 771 on the layer 782, a layer 791 on the light-emitting layer 771, a layer 792 on the layer 791, and an upper electrode 762 on the layer 792.

[0492] When the lower electrode 761 is an anode and the upper electrode 762 is a cathode, for example, the layer 781 can be a hole injection layer, the layer 782 can be a hole transport layer, the layer 791 can be an electron transport layer, and the layer 792 can be an electron injection layer. When the lower electrode 761 is a cathode and the upper electrode 762 is an anode, the layer 781 can be an electron injection layer, the layer 782 can be an electron transport layer, the layer 791 can be a hole transport layer, and the layer 792 can be a hole injection layer. Such a layer structure allows carriers to be efficiently injected into the light-emitting layer 771, and the efficiency of carrier recombination in the light-emitting layer 771 can be increased.

[0493] As shown in Figures 26C and 26D, a variation of the single structure is a configuration in which multiple light-emitting layers (light-emitting layers 771, 772, and 773) are provided between layer 780 and layer 790. While Figures 26C and 26D show an example having three light-emitting layers, the number of light-emitting layers in a single-structure light-emitting device may be two, or may be four or more. Furthermore, a single-structure light-emitting device may have a buffer layer between the two light-emitting layers. The buffer layer can be formed using, for example, a material that can be used for a hole transport layer or an electron transport layer.

[0494] 26E and 26F, a configuration in which a plurality of light-emitting units (light-emitting unit 763a and light-emitting unit 763b) are connected in series via a charge generation layer 785 (also referred to as an intermediate layer) is referred to as a tandem structure in this specification. Note that the tandem structure may also be referred to as a stack structure. By using a tandem structure, a light-emitting device capable of emitting high-luminance light can be obtained. Furthermore, compared to a single structure, the tandem structure can reduce the current required to obtain the same luminance, thereby improving reliability.

[0495] 26D and 26F are examples of display devices having a layer 764 overlapping with the light-emitting device. Fig. 26D is an example in which the layer 764 overlaps with the light-emitting device shown in Fig. 26C, and Fig. 26F is an example in which the layer 764 overlaps with the light-emitting device shown in Fig. 26E. In Fig. 26D and 26F, a conductive film that transmits visible light is used for the upper electrode 762 in order to extract light to the upper electrode 762 side.

[0496] The layer 764 can be a color conversion layer, a color filter (coloring layer), or both.

[0497] 26C and 26D , the light-emitting layers 771, 772, and 773 may be made of light-emitting materials that emit light of the same color, or even the same light-emitting material. For example, the light-emitting layers 771, 772, and 773 may be made of a light-emitting material that emits blue light. In the subpixel that emits blue light, blue light emitted by the light-emitting device can be extracted. Furthermore, in the subpixels that emit red light and the subpixels that emit green light, a color conversion layer can be provided as the layer 764 shown in FIG. 26D to convert the blue light emitted by the light-emitting device into light with a longer wavelength, thereby extracting red or green light. Furthermore, it is preferable to use both a color conversion layer and a colored layer as the layer 764. A portion of the light emitted by the light-emitting device may be transmitted directly without being converted by the color conversion layer. By extracting the light that has passed through the color conversion layer through the colored layer, light other than the desired color can be absorbed by the colored layer, thereby improving the color purity of the light emitted by the subpixel.

[0498] 26C and 26D , light-emitting layers 771, 772, and 773 may each contain light-emitting materials that emit light of a different color. When the lights emitted by light-emitting layers 771, 772, and 773 are complementary in color, white light can be obtained. For example, a light-emitting device with a single structure preferably includes a light-emitting layer containing a light-emitting material that emits blue light and a light-emitting layer containing a light-emitting material that emits visible light with a wavelength longer than that of the blue light.

[0499] 26D, a color filter is preferably provided as layer 764. When white light passes through the color filter, light of a desired color can be obtained.

[0500] For example, when a light-emitting device with a single structure has three light-emitting layers, it preferably has a light-emitting layer having a light-emitting material that emits red (R) light, a light-emitting layer having a light-emitting material that emits green (G) light, and a light-emitting layer having a light-emitting material that emits blue (B) light. The stacking order of the light-emitting layers can be, for example, R, G, B from the anode side, or R, B, G from the anode side. In this case, a buffer layer may be provided between R and G or B.

[0501] Furthermore, for example, when a light-emitting device with a single structure has two light-emitting layers, a structure having one light-emitting layer containing a light-emitting substance that emits blue (B) light and another light-emitting layer containing a light-emitting substance that emits yellow (Y) light is preferred. This structure is sometimes referred to as a BY single structure.

[0502] A light-emitting device that emits white light preferably contains two or more types of light-emitting materials. When white light emission is obtained using two light-emitting layers, light-emitting materials may be selected so that the emission colors of the two light-emitting layers are complementary to each other. For example, a light-emitting device that emits white light as a whole can be obtained by making the emission color of the first light-emitting layer and the emission color of the second light-emitting layer complementary to each other. Furthermore, when white light emission is obtained using three or more light-emitting layers, the emission colors of the three or more light-emitting layers may be combined to form a configuration in which the light-emitting device as a whole emits white light.

[0503] 26C and 26D, the layer 780 and the layer 790 may each independently have a laminated structure made up of two or more layers, as shown in FIG. 26B.

[0504] 26E and 26F , the light-emitting layer 771 and the light-emitting layer 772 may be made of a light-emitting material that emits light of the same color, or even the same light-emitting material. For example, in a light-emitting device having subpixels that emit light of different colors, the light-emitting layer 771 and the light-emitting layer 772 may each be made of a light-emitting material that emits blue light. In the subpixel that emits blue light, the blue light emitted by the light-emitting device can be extracted. In the subpixel that emits red light and the subpixel that emits green light, a color conversion layer can be provided as the layer 764 shown in FIG. 26F to convert the blue light emitted by the light-emitting device into light with a longer wavelength, thereby allowing red or green light to be extracted. Furthermore, it is preferable to use both a color conversion layer and a colored layer as the layer 764.

[0505] 26E and 26F, the light-emitting layer 771 and the light-emitting layer 772 may be made of light-emitting materials that emit light of different colors. When the light emitted by the light-emitting layer 771 and the light emitted by the light-emitting layer 772 are complementary colors, white light can be obtained. A color filter is preferably provided as the layer 764 shown in FIG. 26F. When white light passes through the color filter, light of a desired color can be obtained.

[0506] 26E and 26F show an example in which the light-emitting unit 763a has one light-emitting layer 771 and the light-emitting unit 763b has one light-emitting layer 772, but this is not limiting. Each of the light-emitting unit 763a and the light-emitting unit 763b may have two or more light-emitting layers.

[0507] 26E and 26F illustrate light-emitting devices having two light-emitting units, but the present invention is not limited to this. The light-emitting device may have three or more light-emitting units. Note that a configuration having two light-emitting units may be referred to as a two-tiered tandem structure, and a configuration having three light-emitting units may be referred to as a three-tiered tandem structure.

[0508] 26E and 26F, the light-emitting unit 763a includes a layer 780a, a light-emitting layer 771, and a layer 790a, and the light-emitting unit 763b includes a layer 780b, a light-emitting layer 772, and a layer 790b.

[0509] When the lower electrode 761 is an anode and the upper electrode 762 is a cathode, the layers 780a and 780b each have one or more of a hole injection layer, a hole transport layer, and an electron blocking layer. The layers 790a and 790b each have one or more of an electron injection layer, an electron transport layer, and a hole blocking layer. When the lower electrode 761 is a cathode and the upper electrode 762 is an anode, the layers 780a and 790a have the opposite structures to those described above, and the layers 780b and 790b also have the opposite structures to those described above.

[0510] When the lower electrode 761 is an anode and the upper electrode 762 is a cathode, for example, the layer 780a may have a hole injection layer, a hole transport layer on the hole injection layer, and an electron blocking layer on the hole transport layer. The layer 790a may have an electron transport layer and a hole blocking layer between the light-emitting layer 771 and the electron transport layer. The layer 780b may have a hole transport layer and an electron blocking layer on the hole transport layer. The layer 790b may have an electron transport layer, an electron injection layer on the electron transport layer, and a hole blocking layer between the light-emitting layer 772 and the electron transport layer. When the lower electrode 761 is a cathode and the upper electrode 762 is an anode, for example, the layer 780a may have an electron injection layer, an electron transport layer on the electron injection layer, and an electron blocking layer on the electron transport layer. Layer 790a has a hole transport layer and may further have an electron blocking layer between light-emitting layer 771 and the hole transport layer. Layer 780b has an electron transport layer and may further have a hole blocking layer on the electron transport layer. Layer 790b has a hole transport layer and a hole injection layer on the hole transport layer and may further have an electron blocking layer between light-emitting layer 772 and the hole transport layer.

[0511] When a light-emitting device having a tandem structure is fabricated, two light-emitting units are stacked via a charge generation layer 785. The charge generation layer 785 has at least a charge generation region. The charge generation layer 785 has a 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.

[0512] An example of a light emitting device with a tandem structure is shown in FIGS. 27A to 27C.

[0513] 27A shows a configuration having three light-emitting units. In FIG. 27A, a plurality of light-emitting units (light-emitting unit 763a, light-emitting unit 763b, and light-emitting unit 763c) are connected in series via charge generation layers 785. Furthermore, light-emitting unit 763a includes layer 780a, light-emitting layer 771, and layer 790a. Light-emitting unit 763b includes layer 780b, light-emitting layer 772, and layer 790b. Light-emitting unit 763c includes layer 780c, light-emitting layer 773, and layer 790c. Note that layer 780c can have a structure applicable to layers 780a and 780b, and layer 790c can have a structure applicable to layers 790a and 790b.

[0514] 27A , the light-emitting layer 771, the light-emitting layer 772, and the light-emitting layer 773 can have light-emitting materials that emit light of the same color. Specifically, the light-emitting layer 771, the light-emitting layer 772, and the light-emitting layer 773 can all have a structure containing a blue (B) light-emitting material (a so-called B\B\B three-stage tandem structure). Note that "a\b" means that a light-emitting unit having a light-emitting material that emits light of b is provided on a light-emitting unit having a light-emitting material that emits light of a, via a charge-generating layer, and a and b represent colors.

[0515] 27A , light-emitting materials emitting light of different colors can be used for some or all of the light-emitting layers 771, 772, and 773. Examples of combinations of the light-emitting colors of the light-emitting layers 771, 772, and 773 include a configuration in which two of them are blue (B) and the remaining one is yellow (Y), and a configuration in which one of them is red (R), the other one is green (G), and the remaining one is blue (B).

[0516] 27B shows a tandem light-emitting device in which light-emitting units each having a plurality of light-emitting layers are stacked. In this configuration, two light-emitting units (light-emitting unit 763a and light-emitting unit 763b) are connected in series via a charge generation layer 785. Light-emitting unit 763a includes layer 780a, light-emitting layers 771a, 771b, and 771c, and layer 790a. Light-emitting unit 763b includes layer 780b, light-emitting layers 772a, 772b, and 772c, and layer 790b.

[0517] In FIG. 27B , light-emitting materials having complementary colors are selected for the light-emitting layers 771a, 771b, and 771c, and the light-emitting unit 763a is configured to emit white light (W). Light-emitting materials having complementary colors are also selected for the light-emitting layers 772a, 772b, and 772c, and the light-emitting unit 763b is configured to emit white light (W). In other words, the structure shown in FIG. 27B can be said to have a W\W two-tier tandem structure. There is no particular limitation on the stacking order of the light-emitting materials having complementary colors. The implementer can select the optimal stacking order as appropriate. Although not shown, a W\W\W three-tier tandem structure or a four-tier or more tandem structure may also be used.

[0518] Furthermore, examples of light-emitting devices with a tandem structure include a two-stage tandem structure of B\Y or Y\B having a light-emitting unit that emits yellow (Y) light and a light-emitting unit that emits blue (B) light, a two-stage tandem structure of R.G\B or B\R.G having a light-emitting unit that emits red (R) and green (G) light and a light-emitting unit that emits blue (B) light, and a light-emitting unit that emits yellow (Y) light and a light-emitting unit that emits blue (B) light. Examples of such a tandem structure include a B\Y\B three-stage tandem structure having, in this order, a light-emitting unit that emits blue (B) light, a light-emitting unit that emits yellow-green (YG) light, and a light-emitting unit that emits blue (B) light, a B\YG\B three-stage tandem structure having, in this order, a light-emitting unit that emits blue (B) light, a light-emitting unit that emits green (G) light, and a light-emitting unit that emits blue (B) light. Note that "a·b" means that one light-emitting unit has a light-emitting substance that emits light of a and a light-emitting substance that emits light of b.

[0519] Furthermore, as shown in FIG. 27C, a light-emitting unit having one light-emitting layer and a light-emitting unit having multiple light-emitting layers may be combined.

[0520] 27C , a plurality of light-emitting units (light-emitting unit 763a, light-emitting unit 763b, and light-emitting unit 763c) are connected in series via charge generation layers 785. Light-emitting unit 763a includes a layer 780a, a light-emitting layer 771, and a layer 790a. Light-emitting unit 763b includes a layer 780b, a light-emitting layer 772a, a light-emitting layer 772b, a light-emitting layer 772c, and a layer 790b. Light-emitting unit 763c includes a layer 780c, a light-emitting layer 773, and a layer 790c.

[0521] In the configuration shown in Figure 27C, for example, a three-stage tandem structure of B\R·G·YG\B can be applied, in which light-emitting unit 763a is a light-emitting unit that emits blue (B) light, light-emitting unit 763b is a light-emitting unit that emits red (R), green (G), and yellow-green (YG) light, and light-emitting unit 763c is a light-emitting unit that emits blue (B) light.

[0522] Examples of the number of layers of the light-emitting units and the order of the colors include, from the anode side, a two-layer structure of B and Y, a two-layer structure of B and light-emitting unit X, a three-layer structure of B, Y, and B, and a three-layer structure of B, X, and B. Examples of the number of layers of the light-emitting layers in light-emitting unit X and the order of the colors include, from the anode side, a two-layer structure of R and Y, a two-layer structure of R and G, a two-layer structure of G and R, a three-layer structure of G, R, and G, or a three-layer structure of R, G, and R. Furthermore, another layer may be provided between the two light-emitting layers.

[0523] Next, materials that can be used in light-emitting devices will be described.

[0524] Of the lower electrode 761 and the upper electrode 762, a conductive film that transmits visible light is used for the electrode from which light is extracted. A conductive film that reflects visible light is preferably used for the electrode from which light is not extracted. When the display device has a light-emitting device that emits infrared light, a conductive film that transmits visible light and infrared light is preferably used for the electrode from which light is extracted, and a conductive film that reflects visible light and infrared light is preferably used for the electrode from which light is not extracted.

[0525] 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, the electrode is preferably disposed between the reflective layer and the EL layer 763. That is, light emitted from the EL layer 763 may be reflected by the reflective layer and extracted from the display device.

[0526] For the lower electrode 761 and the upper electrode 762, the material which can be used for a pair of electrodes of the light-emitting device described in Embodiment Mode 1 can be used.

[0527] The light-emitting device has at least a light-emitting layer. The light-emitting device may further include a layer other than the light-emitting layer, which includes a substance having a high hole-injection property, a substance having a high hole-transport property, a hole-blocking material, a substance having a high electron-transport property, an electron-blocking material, a substance having a high electron-injection property, or a bipolar substance (a substance having high electron-transport and hole-transport properties, also referred to as a bipolar material). For example, the light-emitting device may have, in addition to the light-emitting layer, one or more layers selected from a hole-injection layer, a hole-transport layer, a hole-blocking layer, a charge-generating layer, an electron-blocking layer, an electron-transport layer, and an electron-injection layer.

[0528] 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.

[0529] The light-emitting layer contains one or more light-emitting materials. As the light-emitting material, a material that emits light of blue, purple, blue-purple, green, yellow-green, yellow, orange, red, or the like is appropriately used. Furthermore, a material that emits near-infrared light can also be used as the light-emitting material.

[0530] The light-emitting material may include a fluorescent material, a phosphorescent material, a TADF material, and a quantum dot material.

[0531] 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.

[0532] 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.

[0533] The light-emitting layer may contain one or more organic compounds (host material, assist material, etc.) in addition to the light-emitting substance (guest material). As the one or more organic compounds, one or both of a substance with high hole-transporting properties (hole-transporting material) and a substance with high electron-transporting properties (electron-transporting material) can be used. As the hole-transporting material, a substance with high hole-transporting properties that can be used in a hole-transporting layer, which will be described later, can be used. As the electron-transporting material, a substance with high electron-transporting properties that can be used in an electron-transporting layer, which will be described later, can be used. Furthermore, as the one or more organic compounds, a bipolar material or a TADF material may be used.

[0534] 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.

[0535] 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).

[0536] As the hole transporting material, a substance with high hole transporting properties that can be used for a hole transporting layer, which will be described later, can be used.

[0537] Examples of the acceptor material include oxides of metals belonging to Groups 4 to 8 of the periodic table. Specific examples include molybdenum oxide, vanadium oxide, niobium oxide, tantalum oxide, chromium oxide, tungsten oxide, manganese oxide, and rhenium oxide. Among these, molybdenum oxide is particularly preferred because it is stable in the atmosphere, has low hygroscopicity, and is easy to handle. Alternatively, organic acceptor materials containing fluorine can be used. Other organic acceptor materials that can be used include quinodimethane derivatives, chloranil derivatives, and hexaazatriphenylene derivatives.

[0538] For example, as a substance with high hole-injection properties, a material containing a hole-transporting material and an oxide of a metal belonging to Groups 4 to 8 in the periodic table (typically, molybdenum oxide) may be used.

[0539] 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.

[0540] The electron blocking layer is provided in contact with the light-emitting layer. The electron blocking layer is a layer containing a material that has hole transport properties and can block electrons. The electron blocking layer can be made of a material that has electron blocking properties among the hole transport materials described above.

[0541] The electron blocking layer has hole transport properties and can therefore also be called a hole transport layer. Furthermore, a layer of the hole transport layer that has electron blocking properties can also be called an electron blocking layer.

[0542] 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.

[0543] The hole-blocking layer is provided in contact with the light-emitting layer. The hole-blocking layer is a layer containing a material that has electron transport properties and can block holes. The hole-blocking layer can be made of a material that has hole-blocking properties and is selected from the above electron-transporting materials.

[0544] The hole blocking layer has electron transport properties and can therefore also be called an electron transport layer. Furthermore, a layer of the electron transport layer that has hole blocking properties can also be called a hole blocking layer.

[0545] 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).

[0546] Furthermore, it is preferable that the LUMO level of the material with high electron injection properties has a small difference from the work function value of the material used for the cathode (specifically, 0.5 eV or less).

[0547] The electron injection layer may contain, for example, lithium, cesium, ytterbium, lithium fluoride (LiF), cesium fluoride (CsF), calcium fluoride (CaF ｘ , 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 as the first layer and ytterbium is provided as the second layer.

[0548] The electron injection layer may contain an electron transporting material. For example, a compound having an unshared electron pair and an electron-deficient heteroaromatic ring can 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 can be used.

[0549] The lowest unoccupied molecular orbital (LUMO) level of an organic compound having an unshared electron pair is preferably −3.6 eV or more and −2.3 eV or less. Generally, the highest occupied molecular orbital (HOMO) level and the LUMO level of an organic compound can be estimated by CV (cyclic voltammetry), photoelectron spectroscopy, optical absorption spectroscopy, inverse photoelectron spectroscopy, or the like.

[0550] For example, 4,7-diphenyl-1,10-phenanthroline (abbreviation: BPhen), 2,9-di(naphthalen-2-yl)-4,7-diphenyl-1,10-phenanthroline (abbreviation: NBPhen), 2,2′-(1,3-phenylene)bis(9-phenyl-1,10-phenanthroline) (abbreviation: mPPhen2P), 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.

[0551] As described above, the charge generation layer has at least a charge generation region. The charge generation region preferably contains an acceptor material, for example, a hole transport material and an acceptor material applicable to the hole injection layer.

[0552] 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.

[0553] 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.

[0554] 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.

[0555] 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.

[0556] 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.

[0557] 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.

[0558] 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.

[0559] This embodiment mode can be combined with other embodiment modes as appropriate.

[0560] Embodiment 6 In this embodiment, electronic devices of one embodiment of the present invention will be described with reference to FIGS.

[0561] 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.

[0562] 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.

[0563] 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.

[0564] 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. 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.

[0565] The electronic device of this embodiment may have a sensor (including the function of detecting, detecting, or measuring force, displacement, position, velocity, acceleration, angular velocity, rotation speed, distance, light, liquid, magnetism, temperature, chemical substance, sound, time, hardness, electric field, current, voltage, power, radiation, flow rate, humidity, gradient, vibration, odor, or infrared rays).

[0566] 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.

[0567] 28A to 28D , examples of wearable devices that can be worn on the head are described. These wearable devices have at least one of the following functions: a function to display AR content, a function to display VR content, a function to display SR content, and a function to display MR content. By having an electronic device with the function to display at least one of AR, VR, SR, and MR content, it is possible to enhance the sense of immersion felt by the user.

[0568] The electronic device 700A shown in FIG. 28A and the electronic device 700B shown in FIG. 28B 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.

[0569] 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.

[0570] 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.

[0571] 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.

[0572] 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.

[0573] Furthermore, the electronic device 700A and the electronic device 700B are provided with batteries, which can be charged wirelessly and / or by wire.

[0574] 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.

[0575] 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.

[0576] 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. The active layer of the photoelectric conversion device can be made of either or both of an inorganic semiconductor and an organic semiconductor.

[0577] The electronic device 800A shown in Figure 28C and the electronic device 800B shown in Figure 28D 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.

[0578] 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.

[0579] 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.

[0580] 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.

[0581] 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.

[0582] 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. 28C and other figures, the mounting unit 823 is shaped like the temples of glasses, 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.

[0583] 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.

[0584] 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.

[0585] 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.

[0586] 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.

[0587] 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. 28A 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. 28C has a function of transmitting information to the earphone 750 through the wireless communication function.

[0588] The electronic device may also have an earphone unit. Electronic device 700B shown in Fig. 28B 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 wearing unit 723.

[0589] Similarly, electronic device 800B shown in Fig. 28D 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.

[0590] 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.

[0591] 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.

[0592] Furthermore, the electronic device of one embodiment of the present invention can transmit information to the earphone by wire or wirelessly.

[0593] The electronic device 6500 shown in FIG. 29A is a portable information terminal that can be used as a smartphone.

[0594] 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.

[0595] The display device of one embodiment of the present invention can be applied to the display portion 6502 .

[0596] FIG. 29B is a schematic cross-sectional view including the end of the housing 6501 on the microphone 6506 side.

[0597] 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.

[0598] 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).

[0599] 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.

[0600] 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.

[0601] 29C 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.

[0602] The display device of one embodiment of the present invention can be applied to the display portion 7000 .

[0603] 29C 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.

[0604] 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.

[0605] 29D 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.

[0606] The display device of one embodiment of the present invention can be applied to the display portion 7000 .

[0607] 29E and 29F show an example of digital signage.

[0608] 29E 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.

[0609] 29F 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.

[0610] 29E and 29F, the display device of one embodiment of the present invention can be applied to the display portion 7000.

[0611] 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.

[0612] 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.

[0613] 29E and 29F , 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.

[0614] 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.

[0615] The electronic device shown in Figures 30A to 30G has a housing 9000, a display unit 9001, a speaker 9003, operation keys 9005 (including a power switch or an operation switch), a connection terminal 9006, a sensor 9007 (including the function of detecting, detecting, or measuring force, displacement, position, speed, acceleration, angular velocity, rotation speed, distance, light, liquid, magnetism, temperature, chemical substance, sound, time, hardness, electric field, current, voltage, power, radiation, flow rate, humidity, gradient, vibration, odor, or infrared rays), a microphone 9008, etc.

[0616] 30A to 30G, the display device of one embodiment of the present invention can be applied to the display portion 9001.

[0617] The electronic devices shown in Figures 30A to 30G 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 a display unit, etc.

[0618] The electronic devices shown in Figures 30A to 30G will be described in detail below.

[0619] FIG. 30A 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. 30A 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.

[0620] 30B 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.

[0621] 30C 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.

[0622] FIG. 30D 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.

[0623] 30E to 30G are perspective views showing a foldable mobile information terminal 9201. Also, FIG. 30E is a perspective view of the mobile information terminal 9201 in an unfolded state, FIG. 30G is a perspective view of the mobile information terminal 9201 in a folded state, and FIG. 30F is a perspective view of a state in the process of changing from one of FIG. 30E and FIG. 30G to the other. The mobile information terminal 9201 has excellent portability in a folded state, and excellent display visibility due to a seamless, wide display area in an unfolded state. 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.

[0624] This embodiment mode can be combined with other embodiment modes as appropriate.

[0625] 11B: subpixel, 11G: subpixel, 11R: subpixel, 100A: display device, 100B: display device, 100C: display device, 100D: display device, 100E: display device, 100F: display device, 101: layer, 102a: insulating layer, 102b: insulating layer, 102c: insulating layer, 102: insulating layer, 103: plug, 104: sidewall insulating layer, 110a: subpixel, 110b: subpixel, 110c: subpixel, 110d: subpixel, 110: pixel, 111A: pixel electrode, 111a: pixel electrode, 111B: pixel electrode, 111b: pixel electrode, 111C: pixel electrode, 111c: pixel electrode, 111 : pixel electrode, 113s: material layer, 113: first layer, 114: common layer, 115: common electrode, 116B: optical adjustment layer, 116G: optical adjustment layer, 116R: optical adjustment layer, 120: substrate, 122: resin layer, 124a: pixel, 124b: pixel, 125A: insulating film, 125: insulating layer, 127A: insulating film, 127: insulating layer, 130a: light-emitting device, 130b: light-emitting device, 130c: light-emitting device, 130: light-emitting device, 131: protective layer, 132B: colored layer, 132G: colored layer, 132R: colored layer, 133: lens array, 134: insulating layer, 135G: color conversion layer, 135R: color conversion layer, 140: connection portion, 173_1a: groove, 173_1b: groove, 173_2a: groove, 173_2b: groove, 173_3a: groove, 173_3b: groove, 173_4: groove, 173a: groove, 173b: groove, 175_1: groove, 175_2: groove, 175_3: groove, 175: groove, 200A: display device, 200B: display device, 200C: display device, 200D: display device, 200E: display device, 200F: display device, 240: capacitor, 241: conductive layer, 243: insulating layer, 245: conductive layer, 251: conductive layer, 252: conductive layer, 254: insulating layer, 255: insulating layer, 25 6: 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 unit, 282: circuit unit, 283a: pixel circuit, 283: pixel circuit unit, 284a: pixel, 284: pixel unit, 285: terminal unit, 286: wiring unit, 290: FPC, 291: substrate, 292: substrate, 300A: display device, 300B: display device, 300C: display device, 300D: display device, 300E: display device, 300F: display device, 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: plastic 7, 344: insulating layer, 345: insulating layer, 346: insulating layer, 347: bump, 348: adhesive layer, 700A: electronic device, 700B: electronic device, 721: housing, 723: wearing part, 727: earphone part, 750: earphone, 751: display panel, 753: optical member, 756: display area, 757: frame, 758: nose pad, 761: lower electrode, 762: upper electrode, 763a: light-emitting unit, 763b: light-emitting unit, 763c: light-emitting unit, 763: EL layer, 764: layer, 771a: light-emitting layer, 771b: light-emitting layer, 771c: light-emitting layer, 771: light-emitting layer, 7 72a: light-emitting layer, 772b: light-emitting layer, 772c: light-emitting layer, 772: light-emitting layer, 773: light-emitting layer, 780a: layer, 780b: layer, 780c: layer, 780: layer, 781: layer, 782: layer, 785: charge-generating layer, 790a: layer, 790b: layer, 790c: layer, 790: layer, 791: layer, 792: layer, 800A: electronic device, 800B: electronic device, 820: display unit, 821: housing, 822: communication unit, 823: wearing unit, 824: control unit, 825: imaging unit, 827: earphone unit, 832: lens, 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, 7300: 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: mobile information terminal, 9102: mobile information terminal, 9103: tablet terminal, 9200: mobile information terminal, 9201: mobile information terminal,

Claims

1. a first light-emitting device, a second light-emitting device, a first insulating layer, a second insulating layer, a first colored layer, and a second colored layer; the first light-emitting device has a first pixel electrode on the first insulating layer, a first layer on the first pixel electrode, a common layer on the first layer, and a common electrode on the common layer; the second light-emitting device has a second pixel electrode on the first insulating layer, a second layer on the second pixel electrode, the common layer on the second layer, and the common electrode on the common layer; the first insulating layer has a groove; the groove has a region overlapping with the first pixel electrode and a region overlapping with the second pixel electrode, the groove has a region overlapping with the common layer and a region overlapping with the common electrode, the second insulating layer overlaps a side surface of the first layer, a side surface of the second layer, and the groove; the common layer has a portion located on the second insulating layer; the common electrode has a portion located on the second insulating layer; the first colored layer overlies the first light-emitting device; the second colored layer overlies the second light-emitting device; the second colored layer transmits light of a color different from that of the first colored layer; The display device, wherein the first layer and the second layer have the same light-emitting material and are spaced apart from each other.

2. In claim 1, a material layer; In the groove, the material layer is located between the first insulating layer and the second insulating layer; The display device, wherein the first layer, the second layer, and the material layer all have the same light-emitting material and are spaced apart from one another.

3. In claim 1 or 2, the second insulating layer comprises an organic material; The second insulating layer is provided so as to fill the groove.

4. a first light-emitting device, a second light-emitting device, a first insulating layer, a second insulating layer, a first colored layer, and a second colored layer; the first light-emitting device has a first pixel electrode on the first insulating layer, a first layer on the first pixel electrode, a common layer on the first layer, and a common electrode on the common layer; the second light-emitting device has a second pixel electrode on the first insulating layer, a second layer on the second pixel electrode, the common layer on the second layer, and the common electrode on the common layer; the first insulating layer has a first groove and a second groove in a region between the first pixel electrode and the second pixel electrode in a top view; the first groove has a region overlapping with the common layer and a region overlapping with the common electrode, the second groove has a region overlapping with the common layer and a region overlapping with the common electrode, the second insulating layer overlaps a side surface of the first layer, a side surface of the second layer, the first groove, and the second groove; the common layer has a portion located on the second insulating layer; the common electrode has a portion located on the second insulating layer; the first colored layer overlies the first light-emitting device; the second colored layer overlies the second light-emitting device; the second colored layer transmits light of a color different from that of the first colored layer; The display device, wherein the first layer and the second layer have the same light-emitting material and are spaced apart from each other.

5. In claim 4, a first material layer and a second material layer; In the first groove, the first material layer is located between the first insulating layer and the second insulating layer; In the second groove, the second material layer is located between the first insulating layer and the second insulating layer; A display device, wherein the first layer, the second layer, the first material layer, and the second material layer all have the same light-emitting material and are spaced apart from one another.

6. In claim 4 or 5, the second insulating layer comprises an organic material; The second insulating layer is provided so as to fill the first groove and the second groove.

7. In any one of claims 1 to 6, a first light-emitting material that emits blue light and a second light-emitting material that emits light with a wavelength longer than that of blue light;

8. In any one of claims 1 to 6, It has a color conversion layer, the color conversion layer is located between the first light-emitting device and the first coloring layer; the color conversion layer converts blue light into first light having a longer wavelength; the first colored layer transmits the first light; the second colored layer transmits blue light; The display device, wherein the first light-emitting device and the second light-emitting device both emit blue light.

9. In any one of claims 1 to 6, A display device, wherein the transmittance of the second insulating layer for light of one or more colors of red, green, and blue is lower than the transmittance of the first insulating layer.

10. In any one of claims 1 to 6, the first insulating layer has a portion in contact with the first pixel electrode and a portion in contact with the second pixel electrode.