Display device

Abstract

Provided is a novel display device having superior convenience, usefulness, or reliability. Provided is a high-definition display device. Provided is a display device having low power consumption. The display device includes: a pixel electrode; an EL layer on the pixel electrode; and an upper electrode on the EL layer. The EL layer includes a first layer and a second layer on the first layer. The first layer includes a light-emitting material, and the second layer includes zinc and aluminum. The display device converts light from a blue (B) light-emitting element into red (R) or green (G) by using a color conversion layer using quantum dots.

Description

display device

[0001] One aspect of the present invention relates to a display device, a display module, an electronic device, or a semiconductor device.

[0002] Furthermore, one aspect of the present invention is not limited to the above-mentioned technical field. The technical field of one aspect of the invention disclosed herein relates to a product, a method, or a method of manufacture. Alternatively, one aspect of the present invention relates to a process, a machine, a manufacture, or a composition of matter. More specifically, examples of the technical fields of one aspect of the present invention disclosed herein include semiconductor devices, display devices, light-emitting devices, energy storage devices, memory devices, methods for driving them, or methods for manufacturing them.

[0003] The practical application of organic EL devices (organic EL elements), such as light-emitting devices, light-receiving devices, and light-receiving / light-emitting devices, which utilize electroluminescence (EL) using organic compounds, is progressing.

[0004] For example, the basic configuration of a light-emitting device consists of an organic compound layer (EL layer) containing a light-emitting material sandwiched between a pair of electrodes. By applying a voltage to this device, carriers are injected, and by utilizing the recombination energy of these carriers, light emission can be obtained from the light-emitting material.

[0005] In the method of converting the above-mentioned light emission into desired light for each pixel, there are two main methods for converting the light emission from the light-emitting element into desired light: one is to cut out a portion of the light emission from the light-emitting element to obtain the desired light, and the other is to convert the light to obtain the desired light. Compared to the former, which simply cuts out a portion of the obtained light emission, the latter, depending on the efficiency of the conversion, is a configuration that makes it easier to obtain a light-emitting device with less energy loss and lower power consumption.

[0006] One method for obtaining desired light by converting the aforementioned light is to use a color conversion layer that utilizes photoluminescence. The color conversion layer contains a substance that absorbs light, is excited, and emits light. While color conversion layers using organic compounds have existed for a long time, in recent years, color conversion layers using quantum dots (QDs) have been put into practical use.

[0007] For example, a panel is known in which pixels provided in the display area utilize light-emitting elements (light-emitting devices) and quantum dots (Patent Document 1).

[0008] Furthermore, in recent years, HMD (Head-Mounted Display) type electronic devices suitable for applications such as virtual reality (VR) and augmented reality (AR) have become widespread. HMDs are head-mounted devices that can display images in a 360-degree field of view around the observer in response to the user's head movements, gaze, or actions, allowing the user to experience a high level of immersion and presence.

[0009] The display device provided in an HMD is configured to magnify and display images via optical components. In this case, there is a risk of the housing becoming larger due to the inclusion of optical components, or a risk that the user may perceive pixels as more visible and thus experience a strong sense of graininess. Therefore, the display device is required to be high-resolution and / or miniaturized.

[0010] Japanese Patent Publication No. 2016-6768

[0011] One aspect of the present invention aims to provide a novel display device that is excellent in convenience, usefulness, or reliability. Alternatively, it aims to provide a novel display module that is excellent in convenience, usefulness, or reliability. Alternatively, it aims to provide a display device with high resolution. Alternatively, it aims to provide a display device with low power consumption. Alternatively, it aims to provide a method for manufacturing a display device with high productivity. Alternatively, it aims to provide a method for manufacturing a display device with high yield. Alternatively, it aims to provide a novel electronic device that is excellent in convenience, usefulness, or reliability. Alternatively, it aims to provide a novel display device, a novel display module, a novel electronic device, or a novel semiconductor device.

[0012] Furthermore, the description of these problems does not preclude the existence of other problems. Moreover, one aspect of the present invention does not need to solve all of these problems. Other problems will naturally become apparent from the description in the specification, drawings, and claims, and it is possible to extract other problems from the description in the specification, drawings, and claims.

[0013] This device uses a color conversion layer with quantum dots to convert the light from a blue (B) light-emitting element into red (R) or green (G) light. The efficiency of converting the blue (B) light emission to each color is also an important factor. Regarding color conversion efficiency, it depends on the material properties of the quantum dots, but since the light from the blue (B) light-emitting element is absorbed by the material with each quantum dot (also called the QD material), and the green and red light are obtained as PL (photoluminescence) emission, the emission is isotropic and spherical, without directionality.

[0014] One aspect of the present invention is a display device comprising a transistor, a pixel electrode connected to the transistor, an EL layer on the pixel electrode, and an upper electrode on the EL layer, wherein the EL layer comprises a first layer, a second layer on the first layer, and a color conversion layer overlapping the EL layer, the first layer containing a light-emitting material, and the second layer containing zinc and aluminum.

[0015] In the above configuration, the second layer has a region where the ratio of the number of zinc atoms to the number of aluminum atoms is zinc:aluminum = X:1, and it is preferable that X is between 2 and 200.

[0016] In the above configuration, it is preferable that the color conversion layer is a color conversion layer using quantum dots.

[0017] In the above configuration, the EL layer has a third layer between the first layer and the second layer, and the third layer contains an electron-transporting material.

[0018] In the above configuration, the luminescent material is either a blue-luminescent material or a green-luminescent material.

[0019] In the above configuration, there may be a coloring layer that overlaps with the color conversion layer.

[0020] In the above configuration, the semiconductor layer of the transistor is an oxide semiconductor containing indium, such as indium oxide.

[0021] With the above configuration, the outermost surface of the EL layer (organic layer) does not need to be exposed to the etching process by protecting it with a layer containing zinc and aluminum. Therefore, variations in EL properties can be reduced.

[0022] Furthermore, by using a color conversion layer with quantum dots in the color conversion layer that overlaps with the EL layer, the spectrum of light emitted after passing through the color conversion layer is sharp, thereby increasing color purity and meeting the wide color gamut compliant with the BT2020 standard.

[0023] According to one aspect of the present invention, a novel display device with superior convenience, usefulness, or reliability can be provided. Furthermore, one aspect of the present invention can provide a novel display module with superior convenience, usefulness, or reliability. It can also provide a display device with high resolution. Furthermore, it can provide a display device with low power consumption. Furthermore, it can provide a method for manufacturing a display device with high productivity. Furthermore, it can provide a method for manufacturing a display device with high yield. Furthermore, one aspect of the present invention can provide a novel electronic device with superior convenience, usefulness, or reliability. Furthermore, it can provide a novel display device. Furthermore, it can provide a novel display module. Furthermore, it can provide a novel electronic device.

[0024] According to one aspect of the present invention, it is possible to achieve high resolution, a wide color gamut, and a high aperture ratio, thereby realizing a display device with high display quality and high reliability.

[0025] Furthermore, the description of these effects does not preclude the existence of other effects. Moreover, one aspect of the present invention does not necessarily have to possess all of these effects. Other effects will naturally become apparent from the description in the specification, drawings, and claims, and it is possible to extract other effects from the description in the specification, drawings, and claims.

[0026] Figures 1A, 1B, and 1C illustrate the configuration of a display device according to an embodiment. Figures 2A and 2B illustrate the configuration of a display device according to an embodiment. Figures 3A, 3B, and 3C illustrate the configuration of a display device according to an embodiment. Figures 4A and 4B illustrate the configuration of a display device according to an embodiment. Figures 5A and 5B illustrate the configuration of a display device according to an embodiment. Figures 6A, 6B, and 6C illustrate the configuration of a display device according to an embodiment. Figures 7A and 7B illustrate the configuration of a display device according to an embodiment. Figures 8A, 8B, 8C, and 8D illustrate the configuration of a display device according to an embodiment. Figures 9A, 9B, and 9C illustrate the configuration of a display device according to an embodiment. Figures 10A and 10B illustrate the configuration of a display device according to an embodiment. Figures 11A, 11B, and 11C illustrate the configuration of a display device according to an embodiment. Figures 12A and 12B illustrate the configuration of a display device according to an embodiment. Figures 13A and 13B illustrate the configuration of a display device according to an embodiment. Figures 14A, 14B, 14C, and 14D illustrate a method for manufacturing a display device according to an embodiment. Figures 15A, 15B, and 15C illustrate a method for manufacturing a display device according to an embodiment. Figures 16A, 16B, and 16C illustrate the configuration of a display device according to an embodiment. Figure 17 illustrates the configuration of a display device according to an embodiment. Figure 18 illustrates the configuration of a display module according to an embodiment. Figure 19 illustrates the configuration of a display device according to an embodiment. Figure 20 illustrates the configuration of a display device according to an embodiment. Figure 21 illustrates the configuration of a display device according to an embodiment. Figure 22 illustrates the configuration of a display device according to an embodiment. Figure 23 illustrates the configuration of a display device according to an embodiment. Figure 24 illustrates the configuration of a display device according to an embodiment. Figure 25 illustrates the configuration of a display module according to an embodiment. Figures 26A, 26B, and 26C illustrate the configuration of a display device according to an embodiment. Figure 27 illustrates the configuration of a display device according to an embodiment.Figures 28A, 28B, 28C, and 28D illustrate an example of an electronic device according to an embodiment. Figures 29A, 29B, 29C, 29D, 29E, and 29F illustrate an example of an electronic device according to an embodiment. Figures 30A, 30B, 30C, 30D, 30E, 30F, and 30G illustrate an example of an electronic device according to an embodiment.

[0027] Embodiments of the present invention will be described in detail below with reference to the drawings. However, it will be readily apparent to those skilled in the art that the present invention is not limited to the following description, and its form and details can be modified in various ways. Furthermore, the present invention is not to be interpreted as being limited to the embodiments described below.

[0028] In this specification, the terms "first" and "second" may be used for convenience to understand the technical content or to identify each component. Therefore, the terms "first" and "second" do not limit the number of each component. Nor do the terms "first" and "second" limit the order of each component. Furthermore, the terms "first" and "second" or identification codes used in this specification may not correspond to the terms or identification codes in the claims of this patent.

[0029] In this specification, "approximately matching top surface shapes" means that at least a portion of the contours overlap between stacked layers. For example, this includes cases where the upper and lower layers are processed with the same mask pattern, or partially with the same mask pattern. However, strictly speaking, the contours may not overlap, and the upper layer may be located inside the lower layer, or the upper layer may be located outside the lower layer; in these cases, it may also be said that the "top surface shapes are approximately matching."

[0030] In this specification, the top surface shape of a component refers to the contour shape of that component in a plan view. A plan view refers to a view from the direction normal to the surface on which the component is formed, or to the surface of the support (e.g., substrate) on which the component is formed.

[0031] In the following, expressions indicating direction, such as "up" and "down," will generally be used in accordance with the orientation shown in the drawings. However, for the purpose of simplifying explanations, the direction referred to by "up" or "down" in the specification may not coincide with that of the drawings. For example, when explaining the stacking order (or formation order) of a laminate, even if the side on which the laminate is provided (the surface to be formed, the support surface, the adhesive surface, the flat surface, etc.) is located above the laminate in the drawing, it may be expressed as the surface to be formed being below, or the laminate being above.

[0032] Furthermore, in this specification, the terms "film" and "layer" are interchangeable. For example, the term "insulating layer" may be interchangeable with the term "insulating film."

[0033] In this specification, the term "EL layer" refers to a layer (also called a light-emitting layer) provided between a pair of electrodes of a light-emitting device (also called a light-emitting element) and containing at least a light-emitting material, or a laminate including a light-emitting layer.

[0034] In this specification, devices fabricated using a metal mask or FMM (Fine Metal Mask, a high-resolution metal mask) may be referred to as MM (Metal Mask) structured devices. In addition, in this specification, devices fabricated without using a metal mask or FMM may be referred to as MML (Metal Maskless) structured devices.

[0035] In this specification, holes or electrons may be referred to as "carriers." Specifically, a hole injection layer or electron injection layer may be called a "carrier injection layer," a hole transport layer or electron transport layer may be called a "carrier transport layer," and a hole blocking layer or electron blocking layer may be called a "carrier blocking layer." Note that the above-mentioned carrier injection layer, carrier transport layer, and carrier blocking layer may not always be clearly distinguishable. Furthermore, a single layer may combine the functions of two or three of the carrier injection layer, carrier transport layer, and carrier blocking layer.

[0036] In this specification, the term "oxidogenic nitride" refers to a material whose composition contains more oxygen than nitrogen. The term "nitride oxide" refers to a material whose composition contains more nitrogen than oxygen.

[0037] For analyzing the elemental content of hydrogen, oxygen, carbon, nitrogen, etc., contained in a membrane, methods such as secondary ion mass spectrometry (SIMS), X-ray photoelectron spectroscopy (XPS), energy-dispersive X-ray spectroscopy (EDX), time-of-flight secondary ion mass spectrometry (ToF-SIMS), and Auger electron spectroscopy (AES) can be used. XPS is suitable when the content of the target element is high (e.g., 0.5 atomic% or more, or 1 atomic% or more). On the other hand, SIMS is suitable when the content of the target element is low (e.g., 0.5 atomic% or less, or 1 atomic% or less). When comparing elemental content, it is more preferable to perform a combined analysis using both SIMS and XPS analytical methods.

[0038] (Embodiment 1) This embodiment describes a display device according to one aspect of the present invention.

[0039] One aspect of the present invention is a display device having a light-emitting device (also called a light-emitting element). Each light-emitting device has a pair of electrodes and an EL layer between them. Preferably, the light-emitting device is an organic EL element (organic electroluminescent element). For example, by having a light-emitting device that emits blue (B) light and two color conversion layers that convert at least different colors of light, it is possible to convert the light into red (R) light and green (G) light, respectively, to realize a full-color display device.

[0040] Furthermore, to improve color purity, a color filter having a blue (B) colored layer, a red (R) colored layer, and a green (G) colored layer may be provided.

[0041] Furthermore, by providing an intermediate layer between stacked units, two or more light-emitting devices that emit light of different colors can be used. For example, by having light-emitting devices that emit blue (B) light and green (G) light, and three color conversion layers that convert to at least different colors of light, a full-color display device can be realized by converting to red (R) light and green (G) light, respectively. Alternatively, by providing an intermediate layer between stacked units, two or more light-emitting devices that emit light of the same color can be used. For example, by using a light-emitting device made by stacking four units that emit blue (B) light, and having two color conversion layers, a full-color display device can be realized by converting to red (R) light and green (G) light, respectively. Also, the number of units to be stacked is not particularly limited; a display device can be made with a total of four units as one pixel, such as three units that emit blue (B) light stacked, and a unit that emits green (G) light stacked on top of them. Alternatively, a display device can be constructed where a total of four units—two units emitting blue (B) light stacked on top of each other, and two units emitting green (G) light stacked on top of those—form a single pixel.

[0042] When creating separate EL layers for different colored light-emitting devices, it is known that these layers are formed by vapor deposition using shadow masks such as metal masks. However, this method makes it difficult to achieve high resolution and high aperture ratios in display devices because the shape and position of island-like organic films deviate from the design due to various factors such as the precision of the metal mask, misalignment between the metal mask and the substrate, deflection of the metal mask, and the spreading of the contour of the deposited film due to vapor scattering. Therefore, measures are taken to artificially increase resolution (also called pixel density) by applying special pixel arrangement methods such as PenTile arrangements.

[0043] One aspect of the present invention involves processing an EL layer into a fine pattern using photolithography without using a shadow mask such as a metal mask. This makes it possible to realize a display device with high resolution and a large aperture ratio, which has been difficult to achieve until now.

[0044] When etching using photolithography, by placing a hard mask between the organic layer of the EL layer and the photoresist, it is possible to prevent the organic layer of the EL layer from being removed along with the photoresist after processing.

[0045] Furthermore, one aspect of the present invention uses a layer that functions as a hard mask and also functions as a functional layer of a light-emitting device as the upper layer of the EL layer. This eliminates the need for a step to remove the hard mask used in processing. In addition, it is preferable that the functional layer used as the upper layer of the EL layer is stable against oxygen, moisture, etc. This makes it possible to suppress deterioration of the EL layer even when the EL layer is exposed to an atmospheric environment after processing the EL layer and during the manufacturing process of the light-emitting device. Here, the functional layer of the light-emitting device refers to, for example, each functional layer and electrodes of the EL layer.

[0046] In one embodiment of the present invention, a method for manufacturing a display device allows for the production of an EL layer with high resolution and a high aperture ratio, thereby realizing a display device that is extremely vivid, has high contrast, high display quality, and high reliability. Furthermore, since it is stable even when exposed to atmospheric conditions during manufacturing, it is possible to realize a display device with excellent characteristics and high reliability.

[0047] In a method for manufacturing a display device according to one aspect of the present invention, an island-shaped EL layer is formed by first forming a film containing a light-emitting material on one surface, then forming a mask on the film, and processing the film using the mask. Photolithography is preferably used to process the film containing the light-emitting material, and the processing can be carried out using a photoresist as the mask.

[0048] By forming the EL layer using photolithography, the size of the EL layer in a light-emitting device, as well as the spacing between the EL layers of adjacent light-emitting devices, can be made smaller. This makes it possible to achieve high resolution, a wide color gamut, and a high aperture ratio, resulting in a display device with high display quality and reliability.

[0049] In a photolithography-based formation method, the EL layer is formed by etching away areas not covered by the mask. The mask is removed after the EL layer is formed. Removing the mask exposes the upper surface of the EL layer.

[0050] Depending on the equipment and methods used in the mask removal process and subsequent processes, the upper surface of the EL layer may be exposed to an atmosphere containing oxygen, moisture, or both, which may cause alteration or degradation of the EL layer. Degradation of the EL layer raises concerns about increased voltage requirements and reduced reliability of the display device.

[0051] In one embodiment of the present invention, when the EL layer of the light-emitting device has a configuration in which multiple functional layers are stacked, the deterioration of the EL layer after mask removal can be suppressed by using a first layer containing a material with high barrier properties against oxygen, moisture, etc. as the uppermost layer of the stacked functional layers. This makes it possible to achieve excellent characteristics and high reliability of the display device.

[0052] Thus, a display device according to one aspect of the present invention can achieve both high resolution and excellent characteristics.

[0053] Furthermore, using inorganic materials as high-barrier materials can sometimes suppress damage caused by etching during mask removal. For example, even when using dry etching as the mask removal method, degradation of the EL layer can be suppressed, which can be preferable from the standpoint of mass production.

[0054] It is preferable that the layer containing a highly barrier material be formed in a way that causes minimal damage to the functional layer located beneath it. This improves the characteristics and reliability of the display device. For example, an organic material is used for the functional layer of the EL layer. Examples of methods for forming a layer that causes minimal damage to the layer containing the organic material include atomic layer deposition and vacuum deposition. These methods cause less damage to the underlying organic material compared to plasma CVD and sputtering.

[0055] Furthermore, when using atomic layer deposition, it is preferable to lower the film formation temperature to a temperature that is less likely to damage the organic material. Also, it is preferable to use a reactant with lower reactivity with the organic material in atomic layer deposition. For example, an oxidizing agent can be used as the reactant.

[0056] A light-emitting device in a display device according to one aspect of the present invention has an EL layer which includes the above-described first layer. The first layer is a layer containing a material with high barrier properties. Preferably, the first layer also has a function of transporting carriers.

[0057] The first layer can be formed, for example, using atomic layer deposition.

[0058] The first layer preferably has a composition containing a metal oxide. The first layer preferably has a material containing two or more metals selected from zinc, indium, tin, aluminum, gallium, and hafnium, and oxygen.

[0059] Furthermore, the material of the first layer more preferably contains zinc, aluminum, and oxygen. Including aluminum in the material can enhance the barrier properties of the first layer. In addition, by making the atomic ratio of aluminum lower than that of zinc in the material, the carrier transport properties of the first layer can be enhanced.

[0060] Furthermore, the first layer containing the material is, for example, a layer formed using atomic layer deposition. In this case, the first layer may contain elements derived from the precursor. Specifically, for example, the first layer contains carbon as an impurity. If layer 105X contains a carbon concentration of 1 atomic percent or more, the concentration can be evaluated using, for example, scanning transmission electron microscopy (STEM)-EDX analysis. In addition, in STEM-EDX analysis, for example, the material can be processed with a focused ion beam (FIB) and EDX analysis can be performed on the cross-section.

[0061] By using the method described above, it is possible to fabricate different light-emitting devices using photolithography, which enables microfabrication, without using a metal mask. This allows for the creation of display devices with extremely high resolution and a high aperture ratio. Furthermore, it is possible to create an EL layer with high barrier properties against oxygen, moisture, etc., enabling the creation of display devices with excellent characteristics, high resolution, wide color gamut, and high aperture ratio.

[0062] Furthermore, when using a laminate of a first EL layer processed into an island shape and a second EL layer formed on the first EL layer and shared by multiple light-emitting devices, the first layer can be used as the upper layer of the first EL layer.

[0063] Furthermore, it is preferable that the first layer has high barrier properties as well as high stability. For example, it is preferable that it has high stability against oxygen, moisture, etc. Specifically, it is preferable that the physical properties of the film do not change easily when exposed to an atmosphere containing oxygen, moisture, etc. The barrier properties can be enhanced by including zinc, aluminum, and oxygen in the first layer. It is particularly preferable that it includes aluminum.

[0064] A display device according to one aspect of the present invention has a configuration in which a plurality of light-emitting devices are arranged. In addition, the upper electrodes of the plurality of light-emitting devices can be configured to provide a common signal, for example. In this case, the upper electrodes of adjacent light-emitting devices can be connected.

[0065] Furthermore, a display device according to one aspect of the present invention may be configured in which a conductive layer, which functions as auxiliary wiring, is provided between adjacent light-emitting devices. By providing this conductive layer, the upper electrodes of adjacent light-emitting devices can also be connected via the auxiliary wiring. This makes it possible to prevent the connection of the upper electrodes between adjacent light-emitting devices from being severed, for example, if the coverage of the upper electrodes is low and the upper electrodes become thin between adjacent light-emitting devices, or if the upper electrodes are severed, by providing the auxiliary wiring.

[0066] Furthermore, the conductive layer, which functions as auxiliary wiring, can be constructed using the same material as the first layer of the EL layer. This enhances the barrier properties of the conductive layer.

[0067] Furthermore, the conductive layer that functions as auxiliary wiring can be arranged, for example, below the upper electrode. In one embodiment of the present invention, the upper electrode may be provided in contact with the first layer of the EL layer and the conductive layer that functions as auxiliary wiring. In this case, the first layer of the EL layer and the conductive layer that functions as auxiliary wiring can be made of the same material.

[0068] <Example of Display Device Configuration 1> Figure 1A is a perspective view illustrating the configuration of a display device according to one embodiment of the present invention. Figure 1B is a front view of Figure 1A, and Figure 1C is a front view illustrating a part of Figure 1A. Figure 2A is a cross-sectional view along the cutting line P-Q shown in Figure 1C, and Figure 2B is a cross-sectional view illustrating a configuration different from Figure 2A.

[0069] A display device 700 according to one aspect of the present invention has a set of pixels 703 (see Figure 1A). The display device 700 also has a substrate 510, a functional layer 520, and an insulating layer 573.

[0070] A set of pixels 703 comprises pixels 702A, 702B, and 702C (see Figure 1C).

[0071] Pixel 702A comprises a light-emitting device 550A and a pixel circuit 530A, with the light-emitting device 550A being electrically connected to the pixel circuit 530A (see Figures 2A and 2B). Pixel 702B comprises a light-emitting device 550B and a pixel circuit 530B, with the light-emitting device 550B being electrically connected to the pixel circuit 530B. Pixel 702C comprises a light-emitting device 550C and a pixel circuit 530C, with the light-emitting device 550C being electrically connected to the pixel circuit 530C.

[0072] The functional layer 520 includes pixel circuits 530A, 530B, and 530C. Pixel circuit 530A is sandwiched between the light-emitting device 550A and the substrate 510, pixel circuit 530B is sandwiched between the light-emitting device 550B and the substrate 510, and pixel circuit 530C is sandwiched between the light-emitting device 550C and the substrate 510.

[0073] Furthermore, the functional layer 520 includes an insulating layer 521. The insulating layer 521 is sandwiched between the light-emitting device 550A and the pixel circuit 530A and provides insulation. The insulating layer 521 has an overlapping region that overlaps with the insulating layer 573, and the overlapping region includes the display region 731 (see Figure 1A). The insulating layer 521 sandwiches the light-emitting device 550A between itself and the insulating layer 573.

[0074] Figure 2A shows an example of a top-emission type display device in which light is emitted from the side of the substrate 510 where the light-emitting device is located. Figure 2B shows an example of a bottom-emission type display device in which light is emitted from the substrate 510 side.

[0075] In the configuration shown in Figure 2A, the light-emitting device 550A emits optical ELA in the direction where the pixel circuit 530A is not located, the light-emitting device 550B emits optical ELB in the direction where the pixel circuit 530B is not located, and the light-emitting device 550C emits optical ELC in the direction where the pixel circuit 530C is not located.

[0076] Furthermore, a substrate 760 on which a color conversion layer 762A is provided is positioned so as to overlap with the light-emitting device 550A, and the optical ELA is passed through the color conversion layer 762A. Also, as shown in Figure 2A, the optical ELB is passed through a color conversion layer 762B that is positioned so as to overlap with the light-emitting device 550B. The configuration shown in Figure 2A forms three different colors of light emission.

[0077] Furthermore, the color conversion layers 762A and 762B utilize quantum dots. Quantum dots are semiconductor nanoparticles with a diameter of several nanometers. Due to the quantum size effect, the band gap can be adjusted by the size of the particles, allowing incident light to be converted into light of different wavelengths depending on the particle size. Specifically, as the particle size decreases, it becomes possible to convert light into shorter wavelengths, and as the particle size increases, it becomes possible to convert light into longer wavelengths. In displays that use quantum dots as color conversion layers, this property is utilized to change the particle size for each sub-pixel, thereby converting light of the same wavelength into light of different colors for each sub-pixel, enabling full-color display.

[0078] In the configuration shown in Figure 2B, the light-emitting device 550A emits optical ELA in the direction in which the pixel circuit 530A is located, the light-emitting device 550B emits optical ELB in the direction in which the pixel circuit 530B is located, and the light-emitting device 550C emits optical ELC in the direction in which the pixel circuit 530C is located.

[0079] In the configuration shown in Figure 2B, the substrate 760, on which the color conversion layers 762A and 762B are provided, is fixed to the substrate 510 by an adhesive layer or resin. Then, as shown in Figure 2B, the optical ELA is passed through the color conversion layer 762A, which is provided so as to overlap with the light-emitting device 550A. Also, as shown in Figure 2B, the optical ELB is passed through the color conversion layer 762B, which is provided so as to overlap with the light-emitting device 550B. The configuration shown in Figure 2B forms three different colors of light emission.

[0080] Figure 3A is a cross-sectional view illustrating the configuration of a display device 700 according to one embodiment of the present invention. The display device 700 includes a light-emitting device 550A, a light-emitting device 550B, and a light-emitting device 550C.

[0081] Furthermore, a substrate 760 is provided opposite the substrate 510, and a color layer 761A and a color conversion layer 762A are provided on the substrate 760 in a position overlapping with the light-emitting device 550A. Additionally, a color layer 761B and a color conversion layer 762B are provided in a position overlapping with the light-emitting device 550B. The substrate 760 including the color conversion layer or color layer shown in Figure 3A is collectively referred to as the substrate 120Q having a color conversion layer.

[0082] The colored layers 761A and 761B are also called color filters. Examples of colored layers 761A and 761B include materials containing pigments, materials containing dyes, light-absorbing resin materials (e.g., polyimide), and resin materials that can be used for color filters (color filter materials). The colored layers are colored layers that selectively transmit light in a specific wavelength range and absorb light in other wavelength ranges. For example, a red (R) color filter that transmits light in the red wavelength range, a green (G) color filter that transmits light in the green wavelength range, and a blue (B) color filter that transmits light in the blue wavelength range can be used. One or more of the following can be used in each colored layer: metal materials, resin materials, pigments, and dyes. The colored layers can be formed at desired positions by printing, inkjet printing, photolithography etching, etc.

[0083] Furthermore, although Figure 3A shows an example in which a colored layer or color conversion layer is not provided in a position overlapping with the light-emitting device 550C, the configuration is not particularly limited, and a colored layer or color conversion layer may be provided in a position overlapping with the light-emitting device 550C. Alternatively, a light scattering layer may be provided in a position overlapping with the light-emitting device 550C, for example, a part of the planarization layer 763 and a part of the resin layer 764 may be made into a light scattering layer.

[0084] It is preferable to use either a phosphor or quantum dots, or both, as the color conversion layers 762A and 762B. In particular, quantum dots have a narrow peak width in their emission spectrum and can produce emission with good color purity. This can improve the display quality of the display device.

[0085] There are no particular limitations on the materials that constitute quantum dots. Examples include Group 14 elements, Group 15 elements, Group 16 elements, compounds consisting of multiple Group 14 elements, compounds of elements belonging to Groups 4 through 14 and Group 16 elements, compounds of Group 2 elements and Group 16 elements, compounds of Group 13 elements and Group 15 elements, compounds of Group 13 elements and Group 17 elements, compounds of Group 14 elements and Group 15 elements, compounds of Group 11 elements and Group 17 elements, iron oxides, titanium oxides, chalcogenide spinels, and various semiconductor clusters.

[0086] 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, tel 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, tan oxide Examples include tal, titanium oxide, zirconium oxide, silicon nitride, germanium nitride, aluminum oxide, barium titanate, compounds of selenium, zinc, and cadmium, compounds of indium, arsenic, and phosphorus, compounds of cadmium, selenium, and sulfur, compounds of cadmium, selenium, and tellurium, compounds of indium, gallium, and arsenic, compounds of indium, gallium, and selenium, compounds of indium, selenium, and sulfur, compounds of copper, indium, and sulfur, and combinations thereof. In addition, so-called alloy-type quantum dots, whose composition is expressed in any ratio, may also be used. The materials constituting the quantum dots can be analyzed by, for example, XPS, TOF-SIMS, EDX, and combinations thereof.

[0087] Quantum dot structures include core type, core-shell type, and core-multishell type. Furthermore, because quantum dots have a high proportion of surface atoms, they are highly reactive and prone to aggregation. Therefore, it is preferable that a protective agent or protective group is attached to the surface of the quantum dots. This attachment of a protective agent or protective group prevents aggregation and improves solubility in solvents. It also reduces reactivity and improves electrical stability.

[0088] As the size of a quantum dot decreases, its band gap increases; therefore, its size is adjusted appropriately to obtain light of a desired wavelength. As the size decreases, the emission of quantum dots shifts towards the blue side, i.e., towards higher energy; therefore, by changing the size of the quantum dots, the emission wavelength can be adjusted across the ultraviolet, visible, and infrared spectral wavelength ranges. The size (diameter) of quantum dots is, for example, 0.5 nm to 20 nm, preferably 1 nm to 10 nm. Furthermore, the narrower the size distribution of quantum dots, the narrower the emission spectrum becomes, resulting in emission with good color purity. The shape of 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 exhibiting directional light. The size and distribution of quantum dots can be analyzed using EDX mapping, SP-ICP-MS, etc.

[0089] The color conversion layer can be formed using methods such as droplet ejection (e.g., inkjet), coating, imprint, and various printing methods (screen printing, offset printing). Alternatively, a color conversion film such as a quantum dot film may be used.

[0090] When processing the film that will become the color conversion layer, it is preferable to use photolithography. Photolithography methods include a method in which a resist mask is formed on the thin film to be processed, the thin film is processed by etching or the like, and the resist mask is removed, and a method in which a photosensitive thin film is formed, and then exposed and developed to process the thin film into the desired shape. For example, an island-shaped color conversion layer can be formed by forming a thin film using a material in which quantum dots are mixed with photoresist, and then processing the thin film using photolithography.

[0091] Furthermore, in a display device according to one aspect of the present invention, it is preferable to provide an insulating layer having an opening on a substrate and to provide a color conversion layer within the opening. The insulating layer can be formed using an organic resin film such as acrylic resin, polyamide resin, or epoxy resin, an inorganic insulating film, or an organic polysiloxane. It is particularly preferable to use a photosensitive material and to form the insulating layer so that the side walls of the opening are inclined surfaces with a continuous curvature. By providing the insulating layer, the color conversion layers of each color can be separated, thereby preventing color mixing. Thus, a display device with high display quality can be provided. The insulating layer is also called a partition or embankment because it has the function of separating the color conversion layers of each color.

[0092] However, quantum dots have the drawback of being susceptible to degradation due to the intrusion of impurities such as oxygen. When quantum dots degrade, the light emission intensity of the pixels decreases, and the display quality of the display device deteriorates. Therefore, in display devices that use quantum dots as a color conversion layer, it is necessary to prevent the intrusion of impurities such as oxygen from around the color conversion layer and to prevent the degradation of the quantum dots.

[0093] In this embodiment, a planarization layer 763 is provided to cover the colored layer 761A and the colored layer 761B, a resin layer 764 is provided between the color conversion layer 762A and the color conversion layer 762B, and a protective layer is provided to cover the color conversion layer 762A, the color conversion layer 762B, and the resin layer 764. However, the position and other details are not particularly limited, and other insulating layers or adhesive layers can be provided as appropriate as long as light can pass through.

[0094] The planarization layer 763 and the resin layer 764 preferably each have the function of transmitting visible light. The planarization layer 763 and the resin layer 764 can be configured to include, for example, a resin. The planarization layer 763 and the resin layer 764 can also be configured to have an inorganic insulating layer. Furthermore, the planarization layer 763 and the resin layer 764 can also be configured to include a porous material.

[0095] If light emission with the desired color purity can be obtained solely from the color conversion layer, the configuration may be configured without the colored layer 761A and the colored layer 761B.

[0096] The light-emitting device 550A comprises an electrode 551A, an electrode 552, a unit 103A, a layer 104A, a layer 105A, and a REFA layer. Electrode 552 is shared and used by multiple light-emitting devices. Unit 103A is sandwiched between electrode 551A and electrode 552. Layer 104A is sandwiched between unit 103A and electrode 551A. Layer 105A is sandwiched between unit 103A and electrode 552.

[0097] The light-emitting device 550B comprises an electrode 551B, an electrode 552, a unit 103B, a layer 104B, a layer 105B, and a layer REFB. Unit 103B is sandwiched between electrodes 551B and 552. Layer 104B is sandwiched between unit 103B and electrode 551B. Layer 105B is sandwiched between unit 103B and electrode 552.

[0098] The light-emitting device 550C comprises an electrode 551C, an electrode 552, a unit 103C, a layer 104C, a layer 105C, and a layer REFC. The unit 103C is sandwiched between the electrode 551C and the electrode 552. The layer 104C is sandwiched between the unit 103C and the electrode 551C. The layer 105C is sandwiched between the unit 103C and the electrode 552.

[0099] Units 103A, 103B, and 103C each contain, for example, a luminescent material corresponding to the respective emission colors of light-emitting devices 550A, 550B, and 550C. If the emission colors of light-emitting devices 550A, 550B, and 550C are different, then, for example, units 103A, 103B, and 103C contain different materials. Units 103A, 103B, and 103C may also contain a common material. They may also contain a common material and different materials.

[0100] Layers 104A, 104B, and 104C each contain, for example, a material having hole injection properties. Layers 104A, 104B, and 104C may contain a common material, or they may contain different materials. Alternatively, layers 104A, 104B, and 104C may contain both a common material and different materials.

[0101] It is preferable that each of layers 105A, 105B, and 105C contains, for example, one or more materials having electron injection properties and electron transport properties. It is preferable that layers 105A, 105B, and 105C contain a common material. Alternatively, they may contain materials that are different from each other. Furthermore, layers 105A, 105B, and 105C may contain a common material and materials that are different from each other.

[0102] Electrode 552 includes a region that overlaps with electrode 551A, a region that overlaps with electrode 551B, and a region that overlaps with electrode 551C.

[0103] In the light-emitting devices 550A, 550B, and 550C, for example, layers REFA, REFB, and REFC can have the function of reflecting light toward the electrode 552.

[0104] <Example of configuration of light-emitting device 550X> Figure 3B is a diagram illustrating the configuration of a light-emitting device that can be used in a display device according to one embodiment of the present invention.

[0105] The configuration of the light-emitting device 550X described in this embodiment can be used in a display device according to one aspect of the present invention. The description of the configuration of the light-emitting device 550X can also be applied to the light-emitting device 550A. Specifically, the "X" used in the configuration of the light-emitting device 550X can be read as "A" and adapted to the description of the light-emitting device 550A. Similarly, the configuration of the light-emitting device 550X can be applied to the light-emitting device 550B or the light-emitting device 550C by reading "X" as "B" or "C".

[0106] The light-emitting device 550X described in this embodiment includes an electrode 551X, an electrode 552, and a unit 103X. Electrode 552 overlaps with electrode 551X, and unit 103X is sandwiched between electrode 552 and electrode 551X. Electrode 551X is sometimes called a pixel electrode. Electrode 552 is sometimes called an upper electrode. In the configuration shown in Figure 3A, etc., electrode 552 is shared by multiple light-emitting devices 550X.

[0107] Unit 103X has a single-layer structure or a multi-layer structure. For example, unit 103X comprises layers 111X, 112X, and 113X. Unit 103X has the function of emitting optical ELX.

[0108] Layer 111X is sandwiched between layers 113X and 112X, layer 113X is sandwiched between electrode 552 and layer 111X, and layer 112X is sandwiched between layer 111X and electrode 551X.

[0109] Furthermore, the light-emitting device 550X described in this embodiment has a layer 105X. The layer 105X is sandwiched between the unit 103X and the electrode 552.

[0110] Furthermore, it is preferable that the light-emitting device 550X described in this embodiment has a layer 104X. The layer 104X is sandwiched between the unit 103X and the electrode 551X.

[0111] The light-emitting device 550X described in this embodiment includes an electrode 551X, an island-shaped layer on the electrode 551X, and an electrode 552 on the island-shaped layer. The island-shaped layer can be configured to include a unit 103X and a layer 105X. The unit 103X can be processed using the layer 105X as a mask. In this case, the side surface of the unit 103X and the side surface of the layer 105X can be aligned.

[0112] Each layer of unit 103X, layer 104X, and layer 105X can be made to function as a functional layer selected from, for example, a light-emitting layer, a carrier transport layer, a carrier block layer, a carrier injection layer, an exciton block layer, and a charge generation layer. Furthermore, it is preferable that unit 103X has a light-emitting layer, for example, layer 111X can be made to function as a light-emitting layer.

[0113] Examples of carrier transport layers include hole transport layers and electron transport layers. Examples of carrier injection layers include hole injection layers and electron injection layers.

[0114] Preferably, one or more of layers 105X and 113X function as, for example, carrier transport layers. Alternatively, each of layers 105X and 113X may also function as both a carrier transport layer and a carrier injection layer.

[0115] More preferably, one or more of layers 105X and 113X function as, for example, electron transport layers. In this case, layers 105X and 113X may each have the functions of both an electron transport layer and an electron injection layer.

[0116] In the configuration example shown in Figure 3B, etc., the laminated structure of layer 104X, unit 103X, and layer 105X is sometimes referred to as the "EL layer".

[0117] Figure 3C shows an example configuration of a display device according to one embodiment of the present invention, and differs from Figure 3B in that it has a layer 105_2. The example configuration shown in Figure 3C has a layer 105_2 between layer 105X and electrode 552. Layer 105_2 can function as a carrier injection layer.

[0118] More preferably, layer 105_2 can function as a carrier injection layer.

[0119] In the configuration example shown in Figure 3C, etc., the laminated structure of layer 104X, unit 103X, layer 105X, and layer 105_2 may be referred to as the "EL layer". Also, the laminated structure of layer 104X, unit 103X, and layer 105X may be referred to as the "first EL layer", and layer 105_2 may be referred to as the "second EL layer".

[0120] In the configurations shown in Figures 3B and 3C, unit 103X is sandwiched between layers 104X and 105X, with layer 104X located on the electrode 551 side relative to unit 103X and layer 105X located on the electrode 552 side relative to unit 103X. Unit 103X also comprises layers 111X, 112X and 113X, with layer 111X sandwiched between layers 112X and 113X, with layer 112X located on the electrode 551X side relative to layer 111X and layer 113X located on the electrode 552 side relative to layer 111X.

[0121] The light-emitting device 550X described in this embodiment has the function of emitting light EL1.

[0122] 《Example of the composition of layer 105X》 Layer 105X is, for example, a layer that comes into contact with the mask during processing of the EL layer. Layer 105X is also, for example, a layer that is exposed on the surface during and after processing of the EL layer. Therefore, it is preferable to use a layer as layer 105X that has one or more functions as a carrier transport layer and a carrier injection layer, and has high barrier properties against oxygen, moisture, etc. It is also preferable to use a layer that has low reactivity with oxygen, moisture, etc. and has stable film properties.

[0123] A layer having a metal oxide can be used as layer 105X. The layer having a metal oxide can be formed using various methods. When unit 103X contains an organic compound, it is preferable that layer 105X be formed using a method that causes minimal damage to the organic compound. On the other hand, in order to enhance the barrier properties of layer 105X, it is preferable that layer 105X be dense. Furthermore, it is even preferable that it be dense and have high coverage. By forming layer 105X using atomic layer deposition, damage to unit 103X and its underlying layer can be reduced, and a layer with high coverage and high barrier properties can be formed.

[0124] Furthermore, when atomic layer deposition is used to form layer 105X, for example, by setting the layer formation temperature to 200°C or lower, preferably 150°C or lower, and even more preferably 120°C or lower, damage to unit 103X and the layer below it can be further reduced. Also, considering the reaction temperature with the precursor and reactant (oxidizing agent), the formation temperature is preferably 70°C or higher. In addition, H is used as the reactant in atomic layer deposition. ２ By using O, ３ , H ２ O ２ Compared to using methods such as [mentioning other methods], this method can reduce damage more effectively.

[0125] Layer 105X has a first material, which preferably has one or more metals selected from zinc, indium, tin, aluminum, gallium, and hafnium, and oxygen. Alternatively, the first material may have silicon in addition to one or more of these metals and oxygen.

[0126] Furthermore, the first material preferably contains two or more metals selected from zinc, indium, tin, aluminum, gallium, and hafnium, and oxygen. The first material contains at least element M1 and element M2, and oxygen, where element M1 and element M2 are one and one selected from zinc, indium, tin, aluminum, gallium, and hafnium.

[0127] For example, as element M1 and element M2, one and one selected from a metallic element that can have a tetravalent valency, a metallic element that can have a trivalent valency, and a metallic element that can have a divalent valency can be used.

[0128] For example, one of elements M1 and M2 is a metallic element that can have a divalent valency, and the other is an element that can have a trivalent valency. It is also preferable to use a divalent element as element M1 and a trivalent element as element M2. For example, one of elements M1 and M2 can be an element from group 12, and the other can be an element from group 13. It is also preferable to use a group 12 element as element M1 and a group 13 element as element M2.

[0129] For example, one of elements M1 and M2 may be a metallic element that can have a valency of 3, and the other may be an element that can have a valency of 4. For example, one of elements M1 and M2 may be an element from group 13, and the other may be an element from group 14 or group 4.

[0130] Furthermore, element M1 can be selected from, for example, zinc, indium, and tin.

[0131] Furthermore, it is preferable that element M1 is selected from zinc, indium, and tin, and element M2 is selected from aluminum, gallium, and hafnium. An example of a material that can be used for layer 105 can be expressed as M1-M2 oxide. Alternatively, it is preferable that element M1 is selected from zinc and tin, and element M2 is selected from indium, aluminum, gallium, and hafnium.

[0132] Layer 105X can have the function of transporting carriers by having the first material. Preferably, layer 105X has one or more carrier transport properties and carrier injection properties. In particular, preferably layer 105X has one or more electron transport properties and electron injection properties.

[0133] The first material having the above elements M1 and M2 imparts desirable properties to layer 105X as a carrier transport layer, and enhances the barrier properties and stability of layer 105X.

[0134] Furthermore, it is preferable to use zinc as element M1 and aluminum as element M2. An example of a material that can be used for layer 105X is zinc-aluminum oxide. By increasing the atomic ratio of zinc above that of aluminum, the carrier transport properties of layer 105X can be improved. Also, by including aluminum in the first material, a layer with high barrier properties and high stability can be realized as layer 105X. Furthermore, by setting the atomic ratio of aluminum to zinc within a suitable range, the stability of layer 105X can be further enhanced while maintaining a suitable resistance value. Specifically, high stability means that, for example, when exposed to an atmosphere containing one or more oxygen and moisture, such as air, a layer with small changes in resistance over time can be realized. Small changes in resistance suggest, for example, that there are small changes in the carrier transport properties of layer 105X. Furthermore, by adjusting the atomic ratio of zinc and aluminum in the first material, the carrier transport properties and stability of layer 105X can be improved. Specifically, for example, the number of aluminum atoms is preferably 0.005 times (1 / 200) or more and 0.5 times (1 / 2) or less the number of zinc atoms, more preferably 0.01 times (1 / 100) or more and 0.25 times (1 / 4) or less, even more preferably greater than 1 / 30 (1 / 30) and less than 0.2 times (1 / 5), and typically can be values ​​such as 0.05 times (1 / 20) and 0.1 times (1 / 10). The ratio of element M1 to element M2 can be expressed as M1:M2=X:1 (atomic ratio), where X is, for example, 2 or more and 200 or less, more preferably 4 or more and 100 or less, and even more preferably greater than 5 and less than 30. In particular, when zinc is used as element M1 and aluminum is used as element M2, X is preferably 2 or more and 200 or less, more preferably 4 or more and 100 or less, and especially preferably greater than 5 and less than 30.

[0135] Furthermore, by using atomic layer deposition and the first material described above, the transmittance of layer 105X can be increased. By increasing the transmittance, the luminous efficiency of the light-emitting device can be increased. In one embodiment of the present invention, the metal oxide layer formed using atomic layer deposition is expected to reduce absorption caused by defects and impurity levels, and therefore is expected to increase transmittance, especially in the short wavelength range. In one embodiment of the present invention, for example, the transmittance in the wavelength range corresponding to blue light can be increased. The absorption rate of layer 105X is preferably 5% or less, and more preferably 3% or less, for light wavelengths between 400 nm and 450 nm. In addition, the absorption rate of light wavelengths greater than 450 nm and 760 nm or less is preferably 3% or less, and more preferably 1% or less. The absorption rate can also be, for example, the average value within the range. As the film used as layer 105X, a film can be used that, when a sample is prepared and evaluated for optical properties such as transmittance, absorption rate, and reflectance, has an absorption rate within the above preferred range. For example, a sample for evaluating optical properties can be constructed by depositing the film on a substrate.

[0136] Furthermore, layer 105X is a layer formed using, for example, atomic layer deposition. Therefore, layer 105X may contain elements derived from the precursor. Specifically, for example, layer 105X contains carbon as an impurity. The concentrations and atomic ratios of elements M1, M2, and carbon contained in layer 105X can be measured using, for example, SIMS, EDX, etc.

[0137] Modifications of Layer 105X Layer 105X can be a laminated structure of the metal oxide layer described above and a conductive layer. More specifically, for example, it can be a laminated structure of a first layer and a second layer on the first layer, where the first layer uses an oxide having elements M1 and M2, and the second layer can use a conductive material. As a conductive material, for example, the material described above as suitable for the electrode 552 can be used.

[0138] 《Example of the composition of layer 113X》 Layer 113X has a material that has carrier transport properties. In particular, it is preferable that layer 113X includes a material that has electron transport properties. In addition to the material that has carrier transport properties, layer 113X may also include a material that has carrier implantation properties. For example, layer 113X can be made into a laminated structure, and the layer in contact with layer 105X can be a layer that has carrier implantation properties. Specifically, for example, layer 113X can be made into two layers: a layer that has carrier transport properties and a layer that has carrier implantation properties laminated on top of that layer.

[0139] The following describes in detail an example in which layer 113X includes one or more materials having electron transport properties and materials having electron injection properties. However, if layer 113X includes one or more materials having hole transport properties and materials having hole injection properties, it may be possible to refer to the separately described materials having hole transport properties and materials having hole injection properties.

[0140] <Example of the composition of layer 113X> It is preferable that layer 113X contains an electron transport material.

[0141] Furthermore, layer 113X may also be configured to include an electron-transporting material and an electron-injecting material. Additionally, layer 113X may be configured as a stack of multiple layers. For example, it can be a stacked structure comprising a first layer containing an electron-transporting material and a second layer containing an electron-transporting material. Or, for example, it can be a stacked structure comprising a first layer containing an electron-transporting material and a second layer containing an electron-injecting material.

[0142] Layer 113X can have a configuration containing the organic compound OCX. Layer 113X can also have a laminated structure. In this case, for example, it is preferable that the layer containing the organic compound OCX be placed in a layer in contact with layer 105X among the multiple laminated layers. The multiple layers of layer 113X can be configured as shown below.

[0143] Furthermore, layer 113X can be configured to include the organic compound OCX and the organic compound ETMX.

[0144] Layer 113X can also be a laminated structure comprising, for example, a first layer containing organic compound OCX and organic compound ETMX, and a second layer containing a second organic compound different from organic compound ETMX. In such a case, for example, the first layer is preferably placed on the side closer to layer 105X.

[0145] [Organic Compound OCX] For example, a material having an acid dissociation constant pKa of 8 or higher can be used as the organic compound OCX. Preferably, a material having an acid dissociation constant pKa of 12 or higher can be used as the organic compound OCX.

[0146] Materials with a large acid dissociation constant pKa have a large dipole moment. Materials with a large dipole moment interact with holes. For example, if a material with an acid dissociation constant pKa of 8 or higher is used for the organic compound OCX, the organic compound OCX interacts with holes, and the hole transportability of layer 113X can be significantly reduced.

[0147] Furthermore, materials with a large acid dissociation constant pKa are highly nucleophilic. Highly nucleophilic materials may react with molecules that have received holes and become cation radicals, generating new molecules or intermediate states. For example, if a material with an acid dissociation constant pKa of 8 or higher is used for the organic compound OCX, the organic compound OCX will generate new molecules or intermediate states, significantly reducing the hole transport properties of layer 113X.

[0148] Organic compounds with a high acid dissociation constant pKa include those having a pyrrolidine skeleton, a piperidine skeleton, or a 1,3,4,6,7,8-hexahydro-2H-pyrimido[1,2-a]pyridine skeleton. Organic compounds having a guanidine skeleton are also preferred. Furthermore, organic compounds having a basic skeleton represented by the following structural formulas (120) to (123) can be used.

[0149]

[0150] Furthermore, the organic compounds having an acid dissociation constant pKa of 8 or higher are preferably, more specifically, organic compounds having a bicyclocyclic ring structure with two or more nitrogen atoms constituting the ring, and a heteroaromatic hydrocarbon ring with 2 to 30 carbon atoms constituting the ring, or an aromatic hydrocarbon ring with 6 to 30 carbon atoms constituting the ring, and more specifically, organic compounds having a 1,3,4,6,7,8-hexahydro-2H-pyrimido[1,2-a]pyrimidine skeleton, and a heteroaromatic hydrocarbon ring with 2 to 30 carbon atoms constituting the ring, or an aromatic hydrocarbon ring with 6 to 30 carbon atoms constituting the ring.

[0151] Furthermore, the organic compound represented by the following general formula (G1) can be said to be an organic compound having a guanidine skeleton.

[0152]

[0153] However, in the organic compound represented by the above general formula (G1), X is the group represented by the following general formula (G1-1), and Y is the group represented by the following general formula (G1-2). Also, R １ and R ２ Each of the following independently represents hydrogen or deuterium, h represents an integer from 1 to 6, and Ar represents a heteroaromatic hydrocarbon ring with 2 to 30 carbon atoms constituting the ring, or an aromatic hydrocarbon ring with 6 to 30 carbon atoms constituting the ring, whether substituted or unsubstituted. Ar is preferably a heteroaromatic hydrocarbon ring with 2 to 30 carbon atoms constituting the ring, whether substituted or unsubstituted.

[0154]

[0155] However, in the above general formulas (G1-1) and (G1-2), R ３ ~R ６each independently represent hydrogen or deuterium, m represents an integer of 0 to 4, n represents an integer of 1 to 5, and m+1≧n (m+1 is equal to or greater than n). When m or n is 2 or more, the plurality of R ３ to R ６ may be the same or different from each other.

[0156] Further, the organic compound represented by the above general formula (G1) is preferably any one of the following general formulas (G2-1) to (G2-6).

[0157]

[0158] Provided that R １１ to R ２６ each independently represent hydrogen or deuterium, h represents an integer of 1 to 6, and Ar is a substituted or unsubstituted heteroaromatic hydrocarbon ring having 2 to 30 ring-forming carbon atoms, or a substituted or unsubstituted aromatic hydrocarbon ring having 6 to 30 ring-forming carbon atoms. Ar is preferably a substituted or unsubstituted heteroaromatic hydrocarbon ring having 2 to 30 ring-forming carbon atoms.

[0159] In general formulas (G1) and (G2-1) to (G2-6) above, the heteroaromatic hydrocarbon rings with 2 to 30 carbon atoms constituting the substituted or unsubstituted ring represented by Ar, or the aromatic hydrocarbon rings with 6 to 30 carbon atoms constituting the ring, specifically include pyridine rings, bipyridine rings, pyrimidine rings, bipyrimidine rings, pyrazine rings, bipyrazine rings, triazine rings, quinoline rings, isoquinoline rings, benzoquinoline rings, phenanthroline rings, quinoxaline rings, benzoquinoxaline rings, dibenzoquinoxaline rings, azafluorene rings, diazafluorene rings, carbazole rings, benzocarbasol rings, dibenzocarbasol rings, and dibe Examples include the benzofuran ring, benzonaphthofuran ring, dinaphthofuran ring, dibenzothiophene ring, benzonaphthothiophene ring, dinaphthothiophene ring, benzoflopyridine ring, benzoflopyrimidine ring, benzothiopyridine ring, benzothiopyrimidine ring, naphthoflopyridine ring, naphthothiopyridine ring, naphthothiopyrimidine ring, acridine ring, xanthene ring, phenothiazine ring, phenoxazine ring, phenazine ring, triazole ring, oxazole ring, oxadiazole ring, thiazole ring, thiadiazole ring, imidazole ring, benzimidazole ring, pyrazole ring, and pyrrol ring. Furthermore, in the above general formulas (G1) and (G2-1) to (G2-6), specific examples of heteroaromatic hydrocarbon rings having 6 to 30 carbon atoms constituting a substituted or unsubstituted ring represented by Ar include benzene rings, naphthalene rings, fluorene rings, dimethylfluorene rings, diphenylfluorene rings, spirofluorene rings, anthracene rings, phenanthrene rings, triphenylene rings, pyrene rings, tetracene rings, chrysene rings, benzo[a]anthracene rings, and the like. Among these, it is preferable that it be one of the following structural formulas (Ar-1) to (Ar-27).

[0160]

[0161] Furthermore, it is preferable that the Ar atom contains nitrogen as an atom constituting the ring, and that the Ar is bonded to the skeleton in parentheses in general formula (G1) by a bond between nitrogen or a carbon adjacent to that nitrogen.

[0162] The organometallic compounds represented by the above general formulas (G1) and (G2-1) to (G2-6) are specifically 1,1'-(9,9'-spirobi[9H-fluoren]-2,7-diyl)bis(1,3,4,6,7,8-hexahydro-2H-pyrimido[1,2-a]pyrimidine) (abbreviation: 2,7hpp2SF) (structural formula 108), and 1-(9,9'-spirobi[9H-fluoren]-2-yl)-1,3,4 Examples of organic compounds include ,6,7,8-hexahydro-2H-pyrimido[1,2-a]pyrimidine (abbreviation: 2hppSF) (structural formula 109), and those represented by the following structural formulas (101), (102), (103), (104), (105), (106), (107), (108), (109), (110), (111), (112), (113), (114), (115), (116), and (117).

[0163]

[0164] Such organic compounds are not only stable, but also less likely to cause metal contamination of the manufacturing line compared to alkali metals or alkaline earth metals, or compounds thereof, and are easily deposited. For these reasons, they are more suitable for use in light-emitting devices fabricated using photolithography processes. Of course, they are also suitable for light-emitting devices fabricated using processes that do not involve photolithography.

[0165] Organic compounds with an acid dissociation constant pKa of 8 or higher include 1-(9,9'-spirobi[9H-fluoren]-2-yl)-1,3,4,6,7,8-hexahydro-2H-pyrimido[1,2-a]pyrimidine (abbreviated as 2hppSF), 2,9-bis(1,3,4,6,7,8-hexahydro-2H-pyrimido[1,2-a]pyrimidine-1-yl)-1,10-phenanthroline (abbreviated as 2,9hpp2Phen), and 4,7-di-1-pyrrolidi Organic compounds such as yl-1,10-phenanthroline (abbreviated as Pyrrd-Phen), 8,8'-pyridine-2,6-diyl-bis(5,6,7,8-tetrahydroimidazo[1,2-a]pyrimidine) (abbreviated as 2,6tip2Py), and 4,7-di(2,3,3a,4,5,6,7,7a-octahydro-1H-isoindole-2-yl)-1,10-phenanthroline (abbreviated as Hid2Phen) can be used. Furthermore, organic compounds with an acid dissociation constant pKa of 8 or higher are preferable to not have an electron-transporting skeleton, from the viewpoint of suppressing the recombination of injected electrons and blocked holes on a strongly basic substance with a pKa of 8 or higher.

[0166] For example, nitrogen-containing heterocyclic compounds having a guanidine skeleton can be used in organic compound OCX. Specifically, organic compounds having a 1,3,4,6,7,8-hexahydro-2H-pyrimido[1,2-a]pyrimidine group, organic compounds having a 1,5,6,7-tetrahydroimidazo[1,2-a]pyrimidine group, or nitrogen-containing heterocyclic compounds having a pyrrolidine group can be used in organic compound OCX.

[0167] For example, 2hppSF, 2,9hpp2Phen, 4,Pyrrd-Phen, 2,6tip2Py, or Hid2Phen can be used in organic compounds OCX. The structures of 2hppSF, 2,9hpp2Phen, Pyrrd-Phen, 2,6tip2Py, and Hid2Phen are shown below.

[0168]

[0169] It is preferable that the organic compound OCX does not possess electron-donating properties toward the organic compound ETMX. If the organic compound OCX possesses electron-donating properties, it readily reacts with atmospheric components such as water or oxygen, resulting in poor stability. In one embodiment of the present invention, the layer 113X having the organic compound OCX and the organic compound ETMX can significantly reduce hole transportability, and therefore can function as an electron injection layer even if the organic compound OCX does not possess electron-donating properties. As a result, an electron injection layer and light-emitting device that are stable against atmospheric components such as water or oxygen can be fabricated.

[0170] [Organic Compound ETMX] As the organic compound ETMX, materials with high electron transport properties can be used. Materials with high electron transport properties refer to those in which electron mobility is higher than hole mobility. Specifically, the electron mobility at an electric field strength V / cm square root of 600 is 1 × 10⁻⁶. −７ cm ２ / Vs or more, preferably 1 x 10 −６ cm ２ A material having an electron mobility of 1 / Vs or higher is preferred. Furthermore, as an organic compound with high electron transport properties, for example, heteroaromatic compounds can be used. A heteroaromatic compound is a cyclic compound containing at least two different elements in its ring structure. The ring structure includes 3-membered, 4-membered, 5-membered, and 6-membered rings, but 5-membered or 6-membered rings are particularly preferred. The elements included are preferably one or more of nitrogen, oxygen, or sulfur in addition to carbon. Nitrogen-containing heteroaromatic compounds (nitrogen-containing heteroaromatic compounds) are particularly preferred, and it is preferable to use a material with high electron transport properties (electron-transporting material) such as a nitrogen-containing heteroaromatic compound or an organic compound having a π-electron-deficient heteroaromatic ring containing the same.

[0171] Electron-transporting materials are those in which electron mobility is higher than hole mobility. Specifically, materials in which the electron mobility at an electric field strength V / cm square root of 600 is 1 × 10⁻¹⁶ −７ cm ２ / Vs or more, preferably 1 x 10 −６ cm ２A material having an electron mobility of 1 / Vs or higher is preferred. Furthermore, as an organic compound with high electron transport properties, for example, heteroaromatic compounds can be used. A heteroaromatic compound is a cyclic compound containing at least two different elements in its ring structure. The ring structure includes 3-membered, 4-membered, 5-membered, and 6-membered rings, but 5-membered or 6-membered rings are particularly preferred. The elements included are preferably one or more of nitrogen, oxygen, or sulfur in addition to carbon. Nitrogen-containing heteroaromatic compounds (nitrogen-containing heteroaromatic compounds) are particularly preferred, and it is preferable to use a material with high electron transport properties (electron-transporting material) such as a nitrogen-containing heteroaromatic compound or an organic compound having a π-electron-deficient heteroaromatic ring containing the same.

[0172] Examples of electron-transporting materials include 9-(1-naphthyl)-10-[4-(2-naphthyl)phenyl]anthracene (abbreviation: αN-βNPAnth), 2,9-di(naphthalene-2-yl)-4,7-diphenyl-1,10-phenanthroline (abbreviation: NBPhen), 9-[3'-(dibenzothiophen-4-yl)biphenyl-3-yl]naphtho[1',2':4,5]flou[2,3-b]pyrazine (abbreviation: 9mDBtBPNfpr), and 8-(biphenyl-4-yl)-4-[3-(dibenzothiophen-4-yl)phenyl]-[1]benzoflou[3,2-d ]pyrimidine (abbreviation: 8BP-4mDBtPBfpm), 8-(p-terphenyl-3-yl)-4-[3-(dibenzothiophen-4-yl)phenyl]-[1]benzoflo[3,2-d]pyrimidine (abbreviation: 8mpTP-4mDBtPBfpm), 8-([1,1':4',1''-terphenyl-2,4,5,6,2',3',5',6',2'',3'',4'',5'',6''-d13]-3-yl)-4-[3-(dibenzothiophen-4-yl)phenyl]-[1]benzoflo[3,2-d]pyrimidine (abbreviation: 8mpTP-4mDBtPBfpm-d １３), 9-[3-(4,6-diphenyl-1,3,5-triazine-2-yl)phenyl]-9'-phenyl-2,3'-bi-9H-carbazole (abbreviation: mPCCzPTzn-02), 4,8-bis[3-(dibenzothiophen-4-yl)phenyl]-[1]benzofl[3,2-d]pyrimidine (abbreviation: 4,8mDBtP2Bfpm), 4-[3,5-bis(9H-carbazole-9-yl)phenyl]-2-phenyl-6-(biphenyl-4-yl)pyrimidine (abbreviation: 6BP-4Cz2PPm), 2-[3'-(dibenzothiophen-4-yl)bif [phenyl-3-yl]dibenzo[f,h]quinoxaline (abbreviated as 2mDBTBPDBq-II), 11-[4-(biphenylyl-4-yl)-6-phenyl-1,3,5-triazine-2-yl]-11,12-dihydro-12-(biphenylyl-4-yl)-indro[2,3-a]carbazole (abbreviated as BP-BPIcz(II)TZn), or 11-[3'-(dibenzothiophen-4-yl)biphenyl-3-yl]phenantro[9',10':4,5]fl[2,3-b]pyrazine (abbreviated as 11mDBtBPPnfpr), etc. can be used. These materials are also particularly preferred as organic compounds ETMX (organic compounds used in combination with the previously mentioned organic compounds OCX as organic compounds with a high acid dissociation constant pKa).

[0173] For example, metal complexes or organic compounds having a π-electron-deficient heteroaromatic ring skeleton can be used as electron-transporting materials.

[0174] Examples of metal complexes include bis(10-hydroxybenzo[h]quinolinato)beryllium(II) (abbreviated as BeBq). ２ ), bis(2-methyl-8-quinolinolato)(4-phenylphenolato)aluminum(III) (abbreviation: BAlq), bis(8-quinolinolato)zinc(II) (abbreviation: Znq), bis[2-(2-benzoxazollyl)phenolato]zinc(II) (abbreviation: ZnPBO), bis[2-(2-benzothiazolyl)phenolato]zinc(II) (abbreviation: ZnBTZ), etc. can be used.

[0175] Organic compounds having a π-electron-deficient heteroaromatic ring skeleton include, for example, heterocyclic compounds having an azole skeleton, heterocyclic compounds having a diazine skeleton, heterocyclic compounds having a pyridine skeleton, and heterocyclic compounds having a triazine skeleton. In particular, heterocyclic compounds having a diazine skeleton or a pyridine skeleton are preferred due to their good reliability. Furthermore, heterocyclic compounds having a diazine (pyrimidine or pyrazine) skeleton have high electron transport properties, which can reduce the driving voltage.

[0176] Examples of heterocyclic compounds having an azole skeleton include 2-(4-biphenylyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole (abbreviated as PBD), 3-(4-biphenylyl)-4-phenyl-5-(4-tert-butylphenyl)-1,2,4-triazole (abbreviated as TAZ), and 1,3-bis[5-(p-tert-butylphenyl)-1,3,4-oxadiazole-2-yl]benzene (abbreviated as OX). D-7), 9-[4-(5-phenyl-1,3,4-oxadiazole-2-yl)phenyl]-9H-carbazole (abbreviated as CO11), 2,2',2''-(1,3,5-benzenetriyl)tris(1-phenyl-1H-benzimidazole) (abbreviated as TPBI), 2-[3-(dibenzothiophen-4-yl)phenyl]-1-phenyl-1H-benzimidazole (abbreviated as mDBTBIm-II), etc. can be used.

[0177] Examples of heterocyclic compounds having a diazine skeleton include 2-[3-(dibenzothiophen-4-yl)phenyl]dibenzo[f,h]quinoxaline (abbreviation: 2mDBTPDBq-II), 2-[3'-(dibenzothiophen-4-yl)biphenyl-3-yl]dibenzo[f,h]quinoxaline (abbreviation: 2mDBTBPBq-II), and 2-[3'-(9H-carbazole-9-yl)biphenyl-3-yl]dibenzo[f,h]quinoxaline Noxaline (abbreviation: 2mCzBPDBq), 4,6-bis[3-(phenanthren-9-yl)phenyl]pyrimidine (abbreviation: 4,6mPnP2Pm), 4,6-bis[3-(dibenzothiophen-4-yl)phenyl]pyrimidine (abbreviation: 4,6mDBTP2Pm-II), 4,8-bis[3-(dibenzothiophen-4-yl)phenyl]benzo[h]quinazoline (abbreviation: 4,8mDBtP2Bqn), etc. can be used.

[0178] Examples of heterocyclic compounds having a pyridine skeleton include 3,5-bis[3-(9H-carbazole-9-yl)phenyl]pyridine (abbreviated as 35DCzPPy), 1,3,5-tri[3-(3-pyridyl)phenyl]benzene (abbreviated as TmPyPB), and the like.

[0179] Examples of heterocyclic compounds having a triazine skeleton include 2-[3'-(9,9-dimethyl-9H-fluoren-2-yl)biphenyl-3-yl]-4,6-diphenyl-1,3,5-triazine (abbreviated as mFBPTZn), 2-(biphenyl-4-yl)-4-phenyl-6-(9,9'-spirobi[9H-fluoren]-2-yl)-1,3,5-triazine (abbreviated as BP-SFTZn), and 2-{3-[3-(benzo[b]naphtho[1,2-d]furan-8-yl)phenyl]phenyl}- 4,6-diphenyl-1,3,5-triazine (abbreviation: mBnfBPTZn), 2-{3-[3-(benzo[b]naphtho[1,2-d]furan-6-yl)phenyl]phenyl}-4,6-diphenyl-1,3,5-triazine (abbreviation: mBnfBPTZn-02), 2-[4-(2-naphthyl)phenyl]-4-phenyl-6-spiro[9H-fluoren-9,9'-[9H]xanthene]-4-yl-1,3,5-triazine (abbreviation: βNP-SFx(4)TZn), etc. can be used.

[0180] 《Example of Layer 113X Composition 2》In addition, a material composed of multiple types of substances can be used for layer 113X.

[0181] [Example of Composite Material Composition 1] As the composite material of layer 113X, a microcrystalline alkali metal fluoride and an electron-transporting material can be used. Alternatively, a microcrystalline alkaline earth metal fluoride and an electron-transporting material can be used in the composite material. In particular, a composite material containing 50 wt% or more of alkali metal fluoride or alkaline earth metal fluoride can be suitably used. Alternatively, a composite material containing an organic compound having a bipyridine skeleton can be suitably used. This can lower the refractive index of layer 113X. Alternatively, it can improve the external quantum efficiency of the light-emitting device 550X.

[0182] [Example of Composite Material Composition 2] As the composite material of layer 113X, for example, a composite material containing a first organic compound having lone pairs of electrons and a first metal can be used. It is also preferable that the sum of the number of electrons of the first organic compound and the number of electrons of the first metal is odd. Furthermore, the molar ratio of the first metal to 1 mole of the first organic compound is preferably 0.1 to 10, more preferably 0.2 to 2, and even more preferably 0.2 to 0.8.

[0183] As a result, the first organic compound, which has a lone pair of electrons, can interact with the first metal to form a single-occupied molecular orbital (SOMO). Furthermore, when injecting electrons from electrode 552 into layer 105X, the barrier between the two can be reduced.

[0184] Furthermore, the spin density measured using electron spin resonance (ESR) is preferably 1 × 10⁻⁶. １６ spins / cm ３ More than 5 x 10 １６ spins / cm ３ More preferably 1 x 10 １７ spins / cm ３ The composite material described above can be used for layer 113X.

[0185] [Organic compounds with lone pairs of electrons] For example, materials with electron-transporting properties can be used in organic compounds with lone pairs of electrons. For example, compounds having electron-deficient heteroaromatic rings can be used. Specifically, compounds having at least one of a pyridine ring, a diazine ring (pyrimidine ring, pyrazine ring, pyridazine ring), or a triazine ring can be used. This makes it possible to reduce the driving voltage of the light-emitting device 550X.

[0186] Furthermore, it is preferable that the lowest unoccupied molecular orbital (LUMO) level of the organic compound having a lone pair of electrons is between -3.6 eV and -2.3 eV. In addition, the HOMO (Highest Occupied Molecular Orbital) level and LUMO (Lowest Unoccupied Molecular Orbital) level of the organic compound can generally be estimated by cyclic voltammetry (CV), photoelectron spectroscopy, optical absorption spectroscopy, inverse photoelectron spectroscopy, etc.

[0187] For example, 4,7-diphenyl-1,10-phenanthroline (abbreviated as BPhen), 2,9-di(naphthalene-2-yl)-4,7-diphenyl-1,10-phenanthroline (abbreviated as NBPhen), diquinoxalino[2,3-a:2',3'-c]phenazine (abbreviated as HATNA), 2,4,6-tris[3'-(pyridine-3-yl)biphenyl-3-yl]-1,3,5-triazine (abbreviated as TmPPPyTz), 2,2'-(1,3-phenylene)bis(9-phenyl-1,10-phenanthroline) (abbreviated as mPPhen2P), etc., can be used in organic compounds containing lone pairs of electrons. Compared to BPhen, NBPhen has a higher glass transition temperature (Tg) and superior heat resistance.

[0188] [First Metal] For example, if the number of electrons in the first organic compound having lone pairs is even, a composite material of a metal belonging to an odd group in the periodic table and the first organic compound can be used as the composite material of layer 113X.

[0189] For example, manganese (Mn), a metal of Group 7; cobalt (Co), a metal of Group 9; copper (Cu), silver (Ag), and gold (Au), metals of Group 11; and aluminum (Al) and indium (In), metals of Group 13, are all odd-numbered groups in the periodic table. Furthermore, elements of Group 11 have lower melting points compared to elements of Group 7 or 9, making them suitable for vacuum deposition. Ag, in particular, is preferred due to its low melting point. Additionally, using a metal with poor reactivity with water or oxygen as the first metal can improve the moisture resistance of the light-emitting device 550X.

[0190] Furthermore, if the composite material of layer 113X is such that the number of electrons in the first organic compound having lone pairs is odd, a composite material of a first metal and a first organic compound belonging to an even group in the periodic table can be used. For example, iron (Fe), a metal in group 8, belongs to an even group in the periodic table.

[0191] <Example 3 of the composition of layer 113X> Layer 113X can also be configured to include a material having a LUMO level in the range of -4.3 eV to -3.0 eV.

[0192] Specifically, phthalocyanine-based materials can be used in layer 113X. For example, metal phthalocyanines containing copper, zinc, cobalt, iron, chromium, nickel, etc., such as phthalocyanine (abbreviated as H2Pc), copper(II) phthalocyanine (abbreviated as CuPc), zinc phthalocyanine (abbreviated as ZnPc), cobalt phthalocyanine (abbreviated as CoPc), iron phthalocyanine (abbreviated as FePc), tin phthalocyanine (abbreviated as SnPc), tin oxide phthalocyanine (abbreviated as SnOPc), titanium oxide phthalocyanine (abbreviated as TiOPc), vanadium oxide phthalocyanine (abbreviated as VOPc), and their derivatives, or metal complexes having metal-oxygen bonds and aromatic ligands, etc. Perylenetetracarboxylic acid derivatives such as salino[2,3-a:2',3'-c]phenazine (abbreviated as HATNA), 2,3,8,9,14,15-hexafluorodiquinoxalino[2,3-a:2',3'-c]phenazine (abbreviated as HATNA-F6), 3,4,9,10-perylenetetracarboxylic acid diimide (abbreviated as PTCDI), and 3,4,9,10-perylenetetracarboxyl-bis-benzimidazole (abbreviated as PTCBI), such as (C60-Ih)[5,6]fullerene (abbreviated as C60) and (C70-D5h)[5,6]fullerene (abbreviated as C70), can be used in layer 113X. Among these, CuPc and ZnPc are preferred because they are inexpensive and have good properties. Furthermore, ZnPc has a low diffusion coefficient with respect to silicon, reducing the risk of metal diffusion affecting semiconductor properties. Therefore, it is particularly suitable for application in display devices using silicon semiconductors.

[0193] 《Example of Layer 113X Configuration 4》 For example, an electron-injection material can be used for layer 113X.

[0194] As an electron-injecting material, an electron-donating substance can be used in layer 113X. Alternatively, as an electron-injecting material, a composite material of an electron-donating substance and an electron-transporting material can be used in layer 113X. Alternatively, an electride can be used in layer 113X.

[0195] [Electron-donating substances] For example, alkali metals such as lithium (Li) or cesium (Cs), alkaline earth metals such as magnesium (Mg), calcium (Ca), and strontium (Sr), rare earth metals such as europium (Eu) and ytterbium (Yb), or compounds thereof (oxides, halides, carbonates, etc.) can be used as electron-donating substances. Alternatively, organic compounds such as tetratianaphthalene (abbreviated as TTN), nickerosene, and decamethylnickerosene can also be used as electron-donating substances.

[0196] Examples of alkali metal compounds (including oxides, halides, and carbonates) that can be used include lithium oxide, lithium fluoride (LiF), cesium fluoride (CsF), lithium carbonate, cesium carbonate, 8-hydroxyquinolinatolithium (abbreviated as Liq), etc.

[0197] Alkaline earth metal compounds (including oxides, halides, and carbonates) include calcium fluoride (CaF4). ２ ), etc. can be used.

[0198] Furthermore, two or more of the materials listed above can be used as electron-donating substances. For example, a layer formed by co-depositing two or more of the materials listed above can be used as a layer containing electron-donating substances.

[0199] [Examples of Composite Material Composition] In addition, a material composed of multiple types of substances can be used for layer 113X. For example, a substance having electron-donating properties and a substance having electron-transporting properties can be used in the composite material.

[0200] [Electride] For example, a substance obtained by adding electrons to a mixed oxide of calcium and aluminum at a high concentration can be used in layer 113X.

[0201] [Example of mixed material composition] In addition, a material made by mixing multiple types of substances can be used for layer 113X. Specifically, a mixed material containing alkali metals, alkali metal compounds or alkali metal complexes and substances having electron transport properties can be used for layer 113X.

[0202] For example, a metal complex containing an 8-hydroxyquinolinate structure can be used. Alternatively, methyl-substituted metal complexes containing an 8-hydroxyquinolinate structure (e.g., 2-methyl-substituted or 5-methyl-substituted) can also be used.

[0203] As metal complexes containing the 8-hydroxyquinolinate structure, 8-hydroxyquinolinate-lithium (abbreviated as Liq), 8-hydroxyquinolinate-sodium (abbreviated as Naq), etc., can be used. In particular, monovalent metal ion complexes are preferred, among lithium complexes, and Liq is more preferred.

[0204] <Example 5 of the composition of layer 113X> Organic compounds having an anthracene skeleton can be used in layer 113X. In particular, organic compounds containing both an anthracene skeleton and a heterocyclic skeleton can be preferably used. Furthermore, a layer containing the material described above and a layer containing an organic compound having an anthracene skeleton can be laminated and used together.

[0205] For example, an organic compound containing both an anthracene skeleton and a nitrogen-containing five-membered ring skeleton can be used in layer 113X. Alternatively, an organic compound containing both a nitrogen-containing five-membered ring skeleton with two heteroatoms in the ring and an anthracene skeleton can be used in layer 113X. Specifically, pyrazole rings, imidazole rings, oxazole rings, thiazole rings, etc., can be suitably used as the heterocyclic skeleton.

[0206] Furthermore, for example, an organic compound containing both an anthracene skeleton and a nitrogen-containing six-membered ring skeleton can be used in layer 113X. Alternatively, an organic compound containing both a nitrogen-containing six-membered ring skeleton with two heteroatoms in the ring and an anthracene skeleton can be used in layer 113X. Specifically, pyrazine rings, pyrimidine rings, pyridazine rings, etc., can be suitably used as the heterocyclic skeleton.

[0207] 《Example 6 of Layer 113X Configuration》 Layer 113X can also be a two-layer stacked structure consisting of layer 113X1 and layer 113X2 on top of layer 113X1. For example, the configuration described in Configuration Examples 1 to 3 above can be used as layer 113X1.

[0208] For example, an electron-accepting material can be used in layer 113X2. Alternatively, a composite material containing multiple types of materials can be used in layer 113X2.

[0209] For example, in a film state, using electron spin resonance spectroscopy, 1 × 10 １８ spins / cm ３ Materials exhibiting the above spin densities can be used in layer 113X2. Also, 1 × 10 ４ Ω・cm or more 1×10 ７ A film having an electrical resistivity of Ω·cm or less can be used for layer 113X2. Preferably, layer 113X2 is 5 × 10 ４ Ω・cm or more 1×10 ７ It has an electrical resistivity of Ω·cm or less, and more preferably 1 × 10 ５ Ω・cm or more 1×10 ７ It possesses an electrical resistivity of Ω·cm or less.

[0210] Furthermore, layer 113X3 can be configured to include, for example, a material having a LUMO level in the range of -4.3 eV to -3.0 eV.

[0211] Specifically, phthalocyanine-based materials can be used in layer 113X. For example, metal phthalocyanines containing copper, zinc, cobalt, iron, chromium, nickel, etc., such as phthalocyanine (abbreviated as H2Pc), copper(II) phthalocyanine (abbreviated as CuPc), zinc phthalocyanine (abbreviated as ZnPc), cobalt phthalocyanine (abbreviated as CoPc), iron phthalocyanine (abbreviated as FePc), tin phthalocyanine (abbreviated as SnPc), tin oxide phthalocyanine (abbreviated as SnOPc), titanium oxide phthalocyanine (abbreviated as TiOPc), vanadium oxide phthalocyanine (abbreviated as VOPc), and their derivatives, or metal complexes having metal-oxygen bonds and aromatic ligands, etc. Perylenetetracarboxylic acid derivatives such as salino[2,3-a:2',3'-c]phenazine (abbreviated as HATNA), 2,3,8,9,14,15-hexafluorodiquinoxalino[2,3-a:2',3'-c]phenazine (abbreviated as HATNA-F6), 3,4,9,10-perylenetetracarboxylic acid diimide (abbreviated as PTCDI), and 3,4,9,10-perylenetetracarboxyl-bis-benzimidazole (abbreviated as PTCBI), such as (C60-Ih)[5,6]fullerene (abbreviated as C60) and (C70-D5h)[5,6]fullerene (abbreviated as C70), can be used in layer 113X. Among these, CuPc and ZnPc are preferred because they are inexpensive and have good properties. Furthermore, ZnPc has a low diffusion coefficient with respect to silicon, reducing the risk of metal diffusion affecting semiconductor properties. Therefore, it is particularly suitable for application in display devices using silicon semiconductors.

[0212] [Electron-accepting substances] Organic compounds and inorganic compounds can be used as electron-accepting substances.

[0213] For example, organic compounds having electron-withdrawing groups (halogen groups or cyano groups) can be used as electron-accepting materials. Furthermore, electron-accepting organic compounds are easily vapor-deposited and readily formed into films. This can increase the productivity of the light-emitting device 550X.

[0214] Specifically, 7,7,8,8-tetracyano-2,3,5,6-tetrafluoroquinodimethane (abbreviated as F4-TCNQ), chloranil, 2,3,6,7,10,11-hexacyano-1,4,5,8,9,12-hexaazatriphenylene (abbreviated as HAT-CN), 1,3,4,5,7,8-hexafluorotetracyano-naphthoquinodimethane (abbreviated as F6-TCNNQ), 2-(7-dicyanomethylene-1,3,4,5,6,8,9,10-octafluoro-7H-pyrene-2-ylidene)malononitrile, etc. can be used.

[0215] In particular, compounds in which an electron-withdrawing group is bonded to a condensed aromatic ring having multiple complex atoms, such as HAT-CN, are thermally stable and therefore preferred.

[0216] Furthermore, [3]radialene derivatives having electron-withdrawing groups (especially halogen groups such as fluoro groups or cyano groups) are preferred because they have very high electron-accepting properties.

[0217] Specifically, α,α',α''-1,2,3-cyclopropanetriylidenates[4-cyano-2,3,5,6-tetrafluorobenzeneacetonitrile], α,α',α''-1,2,3-cyclopropanetriylidenates[2,6-dichloro-3,5-difluoro-4-(trifluoromethyl)benzeneacetonitrile], α,α',α''-1,2,3-cyclopropanetriylidenates[2,3,4,5,6-pentafluorobenzeneacetonitrile], etc., can be used.

[0218] Furthermore, transition metal oxides such as molybdenum oxide, vanadium oxide, ruthenium oxide, tungsten oxide, and manganese oxide can be used in materials that have electron-accepting properties.

[0219] Furthermore, phthalocyanine-based compounds such as phthalocyanine (abbreviated as H2Pc), phthalocyanine-based complex compounds such as copper(II) phthalocyanine (abbreviated as CuPc), and compounds having an aromatic amine skeleton such as 4,4'-bis[N-(4-diphenylaminophenyl)-N-phenylamino]biphenyl (abbreviated as DPAB) and N,N'-bis[4-bis(3-methylphenyl)aminophenyl]-N,N'-diphenyl-4,4'-diaminobiphenyl (abbreviated as DNTPD) can be used.

[0220] Furthermore, polymers such as poly(3,4-ethylenedioxythiophene) / polystyrene sulfonic acid (abbreviated as PEDOT / PSS) can be used.

[0221] [Example of composite material composition] For example, a composite material containing an electron-accepting material and a hole-transporting material can be used for layer 113X.

[0222] For example, an organic compound comprising at least one of a π-electron-rich heteroaromatic ring and an aromatic amine can be used as a hole-transporting material. Specifically, compounds having an aromatic amine skeleton, carbazole derivatives, aromatic hydrocarbons, aromatic hydrocarbons having a vinyl group, and polymer compounds (oligomers, dendrimers, polymers, etc.) can be used as organic compounds. Furthermore, if the hole mobility is 1 × 10⁻⁶ −６ cm ２ Materials with a Vs of 1 / Vs or higher can be suitably used in organic compounds. For example, a hole-transporting material that can be used in layer 112X described later can be used in organic compounds.

[0223] Examples of compounds having an aromatic amine skeleton include N,N'-di(p-tolyl)-N,N'-diphenyl-p-phenylenediamine (abbreviated as DTDPPA), 4,4'-bis[N-(4-diphenylaminophenyl)-N-phenylamino]biphenyl (abbreviated as DPAB), N,N'-bis[4-bis(3-methylphenyl)aminophenyl]-N,N'-diphenyl-4,4'-diaminobiphenyl (abbreviated as DNTPD), 1,3,5-tris[N-(4-diphenylaminophenyl)-N-phenylamino]benzene (abbreviated as DPA3B), and the like.

[0224] Examples of carbazole derivatives include 3-[N-(9-phenylcarbazole-3-yl)-N-phenylamino]-9-phenylcarbazole (abbreviated as PCzPCA1), 3,6-bis[N-(9-phenylcarbazole-3-yl)-N-phenylamino]-9-phenylcarbazole (abbreviated as PCzPCA2), and 3-[N-(1-naphthyl)-N-(9-phenylcarbazole-3-yl)amino]-9-phenylcarbazole Bazole (abbreviated as PCzPCN1), 4,4'-di(N-carbazolyl)biphenyl (abbreviated as CBP), 1,3,5-tris[4-(N-carbazolyl)phenyl]benzene (abbreviated as TCPB), 9-[4-(10-phenyl-9-antryl)phenyl]-9H-carbazole (abbreviated as CzPA), 1,4-bis[4-(N-carbazolyl)phenyl]-2,3,5,6-tetraphenylbenzene, etc. can be used.

[0225] Examples of aromatic hydrocarbons include 2-tert-butyl-9,10-di(2-naphthyl)anthracene (abbreviation: t-BuDNA), 2-tert-butyl-9,10-di(1-naphthyl)anthracene, 9,10-bis(3,5-diphenylphenyl)anthracene (abbreviation: DPPA), 2-tert-butyl-9,10-bis(4-phenylphenyl)anthracene (abbreviation: t-BuDBA), 9,10-di(2-naphthyl)anthracene (abbreviation: DNA), 9,10-diphenylanthracene (abbreviation: DPAth), 2-tert-butylanthracene (abbreviation: t-BuAnth), 9,10-bis(4-methyl-1-naphthyl)anthracene (abbreviation: DMNA), and 2-tert-butyl-9,10 -Bis[2-(1-naphthyl)phenyl]anthracene, 9,10-bis[2-(1-naphthyl)phenyl]anthracene, 2,3,6,7-tetramethyl-9,10-di(1-naphthyl)anthracene, 2,3,6,7-tetramethyl-9,10-di(2-naphthyl)anthracene, 9,9'-bianthryl, 10,10'-diphenyl-9,9'-bianthryl, 10,10'-bis(2-phenylphenyl)-9,9'-bianthryl, 10,10'-bis[(2,3,4,5,6-pentaphenyl)phenyl]-9,9'-bianthryl, anthracene, tetracene, rubrene, perylene, 2,5,8,11-tetra(tert-butyl)perylene, pentacene, coronene, etc. can be used.

[0226] Examples of aromatic hydrocarbons having a vinyl group include 4,4'-bis(2,2-diphenylvinyl)biphenyl (abbreviated as DPVBi), 9,10-bis[4-(2,2-diphenylvinyl)phenyl]anthracene (abbreviated as DPVPA), and the like.

[0227] Examples of polymer compounds that can be used include poly(N-vinylcarbazole) (abbreviated as PVK), poly(4-vinyltriphenylamine) (abbreviated as PVTPA), poly[N-(4-{N'-[4-(4-diphenylamino)phenyl]phenyl-N'-phenylamino}phenyl)methacrylamide] (abbreviated as PTPDMA), and poly[N,N'-bis(4-butylphenyl)-N,N'-bis(phenyl)benzidine] (abbreviated as Poly-TPD).

[0228] Furthermore, for example, a substance comprising any one of the carbazole skeleton, dibenzofuran skeleton, dibenzothiophene skeleton, and anthracene skeleton can be suitably used as a hole-transporting material in composite materials. In addition, a substance comprising an aromatic amine having substituents including a dibenzofuran ring or a dibenzothiophene ring, an aromatic monoamine having a naphthalene ring, or an aromatic monoamine in which a 9-fluorenyl group is bonded to the nitrogen of the amine via an arylene group can be used as a hole-transporting material in composite materials. Moreover, using a substance having an N,N-bis(4-biphenyl)amino group can improve the reliability of the light-emitting device 550X.

[0229] Examples of these materials include N-(4-biphenyl)-6,N-diphenylbenzo[b]naphtho[1,2-d]furan-8-amine (abbreviated as BnfABP), N,N-bis(4-biphenyl)-6-phenylbenzo[b]naphtho[1,2-d]furan-8-amine (abbreviated as BBABnf), 4,4'-bis(6-phenylbenzo[b]naphtho[1,2-d]furan-8-yl)-4''-phenyltriphenylamine (abbreviated as BnfBB1BP), N,N-bis(4-biphenyl)benzo[b]naphtho[1,2-d]furan- 6-amine (abbreviation: BBABnf(6)), N,N-bis(4-biphenyl)benzo[b]naphtho[1,2-d]furan-8-amine (abbreviation: BBABnf(8)), N,N-bis(4-biphenyl)benzo[b]naphtho[2,3-d]furan-4-amine (abbreviation: BBABnf(II)(4)), N,N-bis[4-(dibenzofuran-4-yl)phenyl]-4-amino-p-terphenyl (abbreviation: DBfBB1TP), N-[4-(dibenzothiophen-4-yl)phenyl]-N-phenyl-4-biphenylamine (abbreviation :ThBA1BP), 4-(2-naphthyl)-4',4''-diphenyltriphenylamine (abbreviation: BBAβNB), 4-[4-(2-naphthyl)phenyl]-4',4''-diphenyltriphenylamine (abbreviation: BBAβNBi), 4,4'-diphenyl-4''-([2,1'-binaphthyl]-6-yl)triphenylamine (abbreviation: BBAαNβNB), 4,4'-diphenyl-4''-([2,1'-binaphthyl]-7-yl)triphenylamine (abbreviation: BBAαNβNB-03), 4,4'-diphenyl-4'' -(7-phenyl)naphthyl-2-yltriphenylamine (abbreviation: BBAPβNB-03), 4,4'-diphenyl-4''-([2,2'-binaphthyl]-6-yl)triphenylamine (abbreviation: BBA(βN2)B), 4,4'-diphenyl-4''-([2,2'-binaphthyl]-7-yl)triphenylamine (abbreviation: BBA(βN2)B-03), 4,4'-diphenyl-4''-([1,2'-binaphthyl]-4-yl)triphenylamine (abbreviation: BBAβNαNB), 4,4'-diphenyl-4''-([1,2'-binaphthyl]-5-yl)triphenylamine (abbreviation: BBAβNαNB-02), 4-(4-biphenylyl)-4'-(2-naphthyl)-4''-phenyltriphenylamine (abbreviation: TPBiAβNB), 4-(3-biphenylyl)-4'-[4-(2-naphthyl)phenyl]-4''-phenyltriphenylamine (abbreviation: mTPBiAβNBi), 4-(4-biphenylyl)-4'-[4-(2-naphthyl)phenyl]-4''-phenyl Triphenylamine (abbreviation: TPBiAβNBi), 4-phenyl-4'-(1-naphthyl)triphenylamine (abbreviation: αNBA1BP), 4,4'-bis(1-naphthyl)triphenylamine (abbreviation: αNBB1BP), 4,4'-diphenyl-4''-[4'-(carbazole-9-yl)biphenyl-4-yl]triphenylamine (abbreviation: YGTBi1BP), 4'-[4-(3-phenyl-9H-carbazole-9-yl)phenyl]tris (Biphenyl-4-yl)amine (abbreviation: YGTBi1BP-02), 4-[4'-(carbazole-9-yl)biphenyl-4-yl]-4'-(2-naphthyl)-4''-phenyltriphenylamine (abbreviation: YGTBiβNB), N-[4-(9-phenyl-9H-carbazole-3-yl)phenyl]-N-[4-(1-naphthyl)phenyl]-9,9'-spirobio[9H-fluorene]-2-amine (abbreviation: PCBNBSF), N,N-bis( Biphenyl-4-yl)-9,9'-spirobi[9H-fluorene]-2-amine (abbreviation: BBASF), N,N-bis(biphenyl-4-yl)-9,9'-spirobi[9H-fluorene]-4-amine (abbreviation: BBASF(4)), N-(biphenyl-2-yl)-N-(9,9-dimethyl-9H-fluorene-2-yl)-9,9'-spirobi[9H-fluorene]-4-amine (abbreviation: oFBiSF), N-(biphenyl-4-yl)-N-(9,9-dimethyl-9H-fluoren-2-yl)dibenzofuran-4-amine (abbreviation: FrBiF), N-[4-(1-naphthyl)phenyl]-N-[3-(6-phenyldibenzofuran-4-yl)phenyl]-1-naphthylamine (abbreviation: mPDBfBNBN), 4-phenyl-4'-(9-phenylfluoren-9-yl)triphenylamine (abbreviation: BPAFLP), 4-phenyl-3'-(9-phenylfluoren-9-yl)triphenylamine (abbreviation: mBPAFLP), 4-phenyl-4' −[4-(9-phenylfluoren-9-yl)phenyl]triphenylamine (abbreviation: BPAFLBi), 4-phenyl-4'-(9-phenyl-9H-carbazole-3-yl)triphenylamine (abbreviation: PCBA1BP), 4,4'-diphenyl-4''-(9-phenyl-9H-carbazole-3-yl)triphenylamine (abbreviation: PCBi1BP), 4-(1-naphthyl)-4'-(9-phenyl-9H-carbazole-3-yl)triphenylamine (abbreviation: PCBANB), 4,4'- Di(1-naphthyl)-4''-(9-phenyl-9H-carbazole-3-yl)triphenylamine (abbreviation: PCBNBB), N-phenyl-N-[4-(9-phenyl-9H-carbazole-3-yl)phenyl]-9,9'-spirobi[9H-fluorene]-2-amine (abbreviation: PCBASF), N-(biphenyl-4-yl)-N-[4-(9-phenyl-9H-carbazole-3-yl)phenyl]-9,9-dimethyl-9H-fluorene-2-amine (abbreviation: PCBBiF), N,N-bis(9 (9,9-dimethyl-9H-fluoren-2-yl)-9,9'-spirobi-9H-fluoren-4-amine, N,N-bis(9,9-dimethyl-9H-fluoren-2-yl)-9,9'-spirobi-9H-fluoren-3-amine, N,N-bis(9,9-dimethyl-9H-fluoren-2-yl)-9,9'-spirobi-9H-fluoren-2-amine, N,N-bis(9,9-dimethyl-9H-fluoren-2-yl)-9,9'-spirobi-9H-fluoren-1-amine, etc. can be used.

[0230] <Example of Layer 105_2 Configuration> As shown in Figure 3C, the light-emitting device 550X can be configured to have layer 105_2. Layer 105_2 may contain a material that has carrier implantation properties.

[0231] Layer 105_2 preferably contains an electron-injection material. The materials mentioned above can also be used in layer 105_2 as the electron-injection material.

[0232] Furthermore, layer 105_2 may also contain the electron-accepting material mentioned earlier.

[0233] Furthermore, if layer 105_2 contains a material with hole injection properties, it may be possible to refer to the materials that layer 104X may have, as described below.

[0234] <Example of Layer 104X Configuration> Layer 104X can be configured to include a material that has carrier injection properties. For example, Layer 104X is provided in contact with the anode and has the function of facilitating the injection of holes into Unit 103X. It is preferable that Layer 104X has a material that has hole injection properties.

[0235] Layer 104X is phthalocyanine (abbreviation: H ２ It can be formed from phthalocyanine compounds or complex compounds such as Pc, copper(II) phthalocyanine (abbreviated as CuPc), aromatic amine compounds such as 4,4'-bis[N-(4-diphenylaminophenyl)-N-phenylamino]biphenyl (abbreviated as DPAB), N,N'-bis[4-bis(3-methylphenyl)aminophenyl]-N,N'-diphenyl-4,4'-diaminobiphenyl (abbreviated as DNTPD), or polymers such as poly(3,4-ethylenedioxythiophene) / polystyrene sulfonic acid (abbreviated as PEDOT / PSS).

[0236] Furthermore, layer 104X may be formed from an electron-accepting substance (a substance that accepts electrons). Examples of electron-accepting substances include organic compounds having electron-withdrawing groups (halogen groups, cyano groups, etc.), such as 7,7,8,8-tetracyano-2,3,5,6-tetrafluoroquinodimethane (abbreviated as F4-TCNQ), chloranil, 2,3,6,7,10,11-hexacyano-1,4,5,8,9,12-hexaazatriphenylene (abbreviated as HAT-CN), 1,3,4,5,7,8-hexafluorotetracyano-naphthoquinodimethane (abbreviated as F6-TCNNQ), and 2-(7-dicyanomethylene-1,3,4,5,6,8,9,10-octafluoro-7H-pyrene-2-ylidene)malononitrile. In particular, compounds in which an electron-withdrawing group is bonded to a condensed aromatic ring having multiple complex atoms, such as HAT-CN, are thermally stable and therefore preferred. Furthermore, [3]radialene derivatives having an electron-withdrawing group (especially halogen groups such as fluoro groups, cyano groups, etc.) are preferred because they have very high electron-accepting properties. Specific examples include α,α',α''-1,2,3-cyclopropanetriylidenates [4-cyano-2,3,5,6-tetrafluorobenzeneacetonitrile], α,α',α''-1,2,3-cyclopropanetriylidenates [2,6-dichloro-3,5-difluoro-4-(trifluoromethyl)benzeneacetonitrile], and α,α',α''-1,2,3-cyclopropanetriylidenates [2,3,4,5,6-pentafluorobenzeneacetonitrile]. In addition to the organic compounds mentioned above, other substances with acceptor properties that can be used include transition metal oxides such as molybdenum oxide, vanadium oxide, ruthenium oxide, tungsten oxide, and manganese oxide. Furthermore, phthalocyanine (abbreviation: H) can also be used. ２Layer 104X can also be formed by phthalocyanine compounds or complex compounds such as Pc, copper(II) phthalocyanine (abbreviated as CuPc), aromatic amine compounds such as 4,4'-bis[N-(4-diphenylaminophenyl)-N-phenylamino]biphenyl (abbreviated as DPAB), N,N'-bis[4-bis(3-methylphenyl)aminophenyl]-N,N'-diphenyl-4,4'-diaminobiphenyl (abbreviated as DNTPD), or polymers such as poly(3,4-ethylenedioxythiophene) / polystyrene sulfonic acid (abbreviated as PEDOT / PSS). Accepting substances can extract electrons from adjacent hole transport layers (or hole transport materials) by applying an electric field.

[0237] Furthermore, it is preferable that layer 104X be formed from a composite material containing the acceptor material and a hole transport material.

[0238] Various organic compounds can be used as hole-transporting substances in composite materials, including aromatic amine compounds, heteroaromatic compounds, aromatic hydrocarbons, and polymer compounds (oligomers, dendrimers, polymers, etc.). −６ cm ２ It is preferable that the substance has a hole mobility of 1 / Vs or higher. The hole-transporting substance used in the composite material is preferably a compound having a condensed aromatic hydrocarbon ring or a π-electron-rich heteroaromatic ring. As the condensed aromatic hydrocarbon ring, anthracene rings, naphthalene rings, etc. are preferred. As the π-electron-rich heteroaromatic ring, a condensed aromatic ring containing at least one of a pyrrole skeleton, a furan skeleton, or a thiophene skeleton is preferred, and specifically, a carbazole ring, a dibenzothiophene ring, or a ring in which an aromatic ring or heteroaromatic ring is further condensed thereon is preferred.

[0239] Such hole-transporting substances more preferably have one of the following skeletons: a carbazole skeleton, a dibenzofuran skeleton, a dibenzothiophene skeleton, and an anthracene skeleton. In particular, they may be aromatic amines having substituents including a dibenzofuran ring or a dibenzothiophene ring, aromatic monoamines having a naphthalene ring, or aromatic monoamines in which a 9-fluorenyl group is bonded to the nitrogen of the amine via an arylene group. Furthermore, it is preferable that these hole-transporting substances have an N,N-bis(4-biphenyl)amino group, as this allows for the creation of light-emitting devices with a good lifetime.

[0240] Examples of substances possessing hole transport properties as described above include N-(4-biphenyl)-6,N-diphenylbenzo[b]naphtho[1,2-d]furan-8-amine (abbreviation: BnfABP), N,N-bis(4-biphenyl)-6-phenylbenzo[b]naphtho[1,2-d]furan-8-amine (abbreviation: BBABnf), 4,4'-bis(6-phenylbenzo[b]naphtho[1,2-d]furan-8-yl)-4''-phenyltriphenylamine (abbreviation: BnfBB1BP), N,N-bis(4-biphenyl)benzo[b]naphtho[ 1,2-d]furan-6-amine (abbreviation: BBABnf(6)), N,N-bis(4-biphenyl)benzo[b]naphtho[1,2-d]furan-8-amine (abbreviation: BBABnf(8)), N,N-bis(4-biphenyl)benzo[b]naphtho[2,3-d]furan-4-amine (abbreviation: BBABnf(II)(4)), N,N-bis[4-(dibenzofuran-4-yl)phenyl]-4-amino-p-terphenyl (abbreviation: DBfBB1TP), N-[4-(dibenzothiophen-4-yl)phenyl]-N-phenyl-4-biphen Luamine (abbreviation: ThBA1BP), 4-(2-naphthyl)-4',4''-diphenyltriphenylamine (abbreviation: BBAβNB), 4-[4-(2-naphthyl)phenyl]-4',4''-diphenyltriphenylamine (abbreviation: BBAβNBi), 4,4'-diphenyl-4''-([2,1'-binaphthyl]-6-yl)triphenylamine (abbreviation: BBAαNβNB), 4,4'-diphenyl-4''-([2,1'-binaphthyl]-7-yl)triphenylamine (abbreviation: BBAαNβNB-03), 4,4'-diphenyl -4''-(7-phenyl)naphthyl-2-yltriphenylamine (abbreviation: BBAPβNB-03), 4,4'-diphenyl-4''-([2,2'-binaphthyl]-6-yl)triphenylamine (abbreviation: BBA(βN2)B), 4,4'-diphenyl-4''-([2,2'-binaphthyl]-7-yl)triphenylamine (abbreviation: BBA(βN2)B-03), 4,4'-diphenyl-4''-([1,2'-binaphthyl]-4-yl)triphenylamine (abbreviation: BBAβNαNB), 4,4'-diphenyl-4''-([1,2'-binaphthyl]-5-yl)triphenylamine (abbreviation: BBAβNαNB-02), 4-(4-biphenylyl)-4'-(2-naphthyl)-4''-phenyltriphenylamine (abbreviation: TPBiAβNB), 4-(3-biphenylyl)-4'-[4-(2-naphthyl)phenyl]-4''-phenyltriphenylamine (abbreviation: mTPBiAβNBi), 4-(4-biphenylyl)-4'-[4-(2-naphthyl)phenyl]-4''-phenyl Triphenylamine (abbreviation: TPBiAβNBi), 4-phenyl-4'-(1-naphthyl)triphenylamine (abbreviation: αNBA1BP), 4,4'-bis(1-naphthyl)triphenylamine (abbreviation: αNBB1BP), 4,4'-diphenyl-4''-[4'-(carbazole-9-yl)biphenyl-4-yl]triphenylamine (abbreviation: YGTBi1BP), 4'-[4-(3-phenyl-9H-carbazole-9-yl)phenyl]tris (Biphenyl-4-yl)amine (abbreviation: YGTBi1BP-02), 4-[4'-(carbazole-9-yl)biphenyl-4-yl]-4'-(2-naphthyl)-4''-phenyltriphenylamine (abbreviation: YGTBiβNB), N-[4-(9-phenyl-9H-carbazole-3-yl)phenyl]-N-[4-(1-naphthyl)phenyl]-9,9'-spirobio[9H-fluorene]-2-amine (abbreviation: PCBNBSF), N,N-bis( Biphenyl-4-yl)-9,9'-spirobi[9H-fluorene]-2-amine (abbreviation: BBASF), N,N-bis(biphenyl-4-yl)-9,9'-spirobi[9H-fluorene]-4-amine (abbreviation: BBASF(4)), N-(biphenyl-2-yl)-N-(9,9-dimethyl-9H-fluorene-2-yl)-9,9'-spirobi[9H-fluorene]-4-amine (abbreviation: oFBiSF), N-(biphenyl-4-yl)-N-(9,9-dimethyl-9H-fluoren-2-yl)dibenzofuran-4-amine (abbreviation: FrBiF), N-[4-(1-naphthyl)phenyl]-N-[3-(6-phenyldibenzofuran-4-yl)phenyl]-1-naphthylamine (abbreviation: mPDBfBNBN), 4-phenyl-4'-(9-phenylfluoren-9-yl)triphenylamine (abbreviation: BPAFLP), 4-phenyl-3'-(9-phenylfluoren-9-yl)triphenylamine (abbreviation: mBPAFLP), 4-phenyl-4' −[4-(9-phenylfluoren-9-yl)phenyl]triphenylamine (abbreviation: BPAFLBi), 4-phenyl-4'-(9-phenyl-9H-carbazole-3-yl)triphenylamine (abbreviation: PCBA1BP), 4,4'-diphenyl-4''-(9-phenyl-9H-carbazole-3-yl)triphenylamine (abbreviation: PCBi1BP), 4-(1-naphthyl)-4'-(9-phenyl-9H-carbazole-3-yl)triphenylamine (abbreviation: PCBANB), 4,4'- Di(1-naphthyl)-4''-(9-phenyl-9H-carbazole-3-yl)triphenylamine (abbreviation: PCBNBB), N-phenyl-N-[4-(9-phenyl-9H-carbazole-3-yl)phenyl]-9,9'-spirobi[9H-fluorene]-2-amine (abbreviation: PCBASF), N-(biphenyl-4-yl)-N-[4-(9-phenyl-9H-carbazole-3-yl)phenyl]-9,9-dimethyl-9H-fluorene-2-amine (abbreviation: PCBBiF), N,N-bis( Examples include 9,9-dimethyl-9H-fluoren-2-yl)-9,9'-spirobi-9H-fluoren-4-amine, N,N-bis(9,9-dimethyl-9H-fluoren-2-yl)-9,9'-spirobi-9H-fluoren-3-amine, N,N-bis(9,9-dimethyl-9H-fluoren-2-yl)-9,9'-spirobi-9H-fluoren-2-amine, and N,N-bis(9,9-dimethyl-9H-fluoren-2-yl)-9,9'-spirobi-9H-fluoren-1-amine.

[0241] Furthermore, other aromatic amine compounds that possess hole-transporting properties can also be used, such as N,N'-di(p-tolyl)-N,N'-diphenyl-p-phenylenediamine (abbreviated as DTDPPA), 4,4'-bis[N-(4-diphenylaminophenyl)-N-phenylamino]biphenyl (abbreviated as DPAB), N,N'-bis[4-bis(3-methylphenyl)aminophenyl]-N,N'-diphenyl-4,4'-diaminobiphenyl (abbreviated as DNTPD), and 1,3,5-tris[N-(4-diphenylaminophenyl)-N-phenylamino]benzene (abbreviated as DPA3B).

[0242] By forming layer 104X, hole injection properties are improved, and a light-emitting device with a low driving voltage can be obtained.

[0243] Furthermore, among substances with acceptor properties, organic compounds with acceptor properties are easy to use because they are readily deposited and easy to form films.

[0244] 《Example of the composition of layer 112X》 Layer 112X can be composed of a material having carrier transport properties. For example, layer 112X may contain a material having hole transport properties.

[0245] Examples of materials that possess hole transport properties include 1 × 10 −６ cm ２ It is preferable that the hole mobility is greater than or equal to / Vs.

[0246] The above-mentioned hole-transporting substances include 4,4'-bis[N-(1-naphthyl)-N-phenylamino]biphenyl (abbreviated as NPB), N,N'-diphenyl-N,N'-bis(3-methylphenyl)-4,4'-diaminobiphenyl (abbreviated as TPD), N,N'-bis(9,9'-spirobi[9H-fluoren]-2-yl)-N,N'-diphenyl-4,4'-diaminobiphenyl (abbreviated as BSPB), 4-phenyl-4'-(9-phenylfluoren-9-yl)triphenylamine (abbreviated as BPAFLP), and 4-phenyl-3 '-(9-phenylfluoren-9-yl)triphenylamine (abbreviation: mBPAFLP), 4-phenyl-4'-(9-phenyl-9H-carbazole-3-yl)triphenylamine (abbreviation: PCBA1BP), 4,4'-diphenyl-4''-(9-phenyl-9H-carbazole-3-yl)triphenylamine (abbreviation: PCBi1BP), 4-(1-naphthyl)-4'-(9-phenyl-9H-carbazole-3-yl)triphenylamine (abbreviation: PCBANB), 4,4'-di(1-naphthyl)-4''-(9-phenyl Compounds having an aromatic amine skeleton such as 9,9-9H-carbazole-3-yl)triphenylamine (abbreviation: PCBNBB), 9,9-dimethyl-N-phenyl-N-[4-(9-phenyl-9H-carbazole-3-yl)phenyl]fluoren-2-amine (abbreviation: PCBAF), N-phenyl-N-[4-(9-phenyl-9H-carbazole-3-yl)phenyl]-9,9'-spirobi[9H-fluoren]-2-amine (abbreviation: PCBASF), 1,3-bis(N-carbazolyl)benzene (abbreviation: mCP), 4,4'-di( N-carbazolyl)biphenyl (abbreviation: CBP), 3,6-bis(3,5-diphenylphenyl)-9-phenylcarbazole (abbreviation: CzTP), 3,3'-bis(9-phenyl-9H-carbazole) (abbreviation: PCCP), 9,9'-bis(biphenyl-4-yl)-3,3'-bi-9H-carbazole (abbreviation: BisBPCz), 9,9'-bis(biphenyl-3-yl)-3,3'-bi-9H-carbazole (abbreviation: BismBPCz), 9-(biphenyl-3-yl)-9'-(biphenyl-4-yl)-9H,9'H-3,3'-bicarbazole (abbreviation: mBPCCP), 9-(2-naphthyl)-9'-phenyl-3,3'-bi-9H-carbazole (abbreviation: βNCCP), 9-(2-naphthyl-1,3,4,5,6,7,8-d7)-9'-(phenyl-2,3,4,5,6-d5)-3,3'-bi-9H-carbazole-1,1',2,2',4,4',5,5',6,6',7,7',8,8'-d14 (abbreviation: βNCCP-d, ２６), 9-(3-biphenyl)-9'-(2-naphthyl)-3,3'-bi-9H-carbazole (abbreviation: βNCCmBP), 9-(4-biphenyl)-9'-(2-naphthyl)-3,3'-bi-9H-carbazole (abbreviation: βNCBP), 9,9'-di-2-naphthyl-3,3'-9H,9'H-bicarbazole (abbreviation: BisβNCz), 9-(2-naphthyl)-9'-[1,1':4',1”-terphenyl]-3-yl-3,3'-9H,9'H-bicarbazole, 9-(2-naphthyl)-9'-[1,1':3',1” [Terphenyl]-3-yl-3,3'-9H,9'H-bicarbazole, 9-(2-naphthyl)-9'-[1,1':3',1"-terphenyl]-5'-yl-3,3'-9H,9'H-bicarbazole, 9-(2-naphthyl)-9'-[1,1':4',1"-terphenyl]-4-yl-3,3'-9H,9'H-bicarbazole, 9-(2-naphthyl)-9'-[1,1':3',1"-terphenyl]-4-yl-3,3'-9H,9'H-bicarbazole, 9-(2-naphthyl)-9'-(triphenylene-2- 9-(triphenylene-2-yl)-3,3'-9H,9'H-bicarbazole, 9-phenyl-9'-(triphenylene-2-yl)-3,3'-9H,9'H-bicarbazole (abbreviation: PCCzTp), 9,9'-bis(triphenylene-2-yl)-3,3'-9H,9'H-bicarbazole, 9-(4-biphenyl)-9'-(triphenylene-2-yl)-3,3'-9H,9'H-bicarbazole, 9-(triphenylene-2-yl)-9'-[1,1':3',1"-terphenyl]-4-yl-3,3'-9H,9'H-bicarbazole, Compounds having a carbazole skeleton such as, 4,4',4''-(benzene-1,3,5-triyl)tri(dibenzothiophene) (abbreviation: DBT3P-II), 2,8-diphenyl-4-[4-(9-phenyl-9H-fluoren-9-yl)phenyl]dibenzothiophene (abbreviation: DBTFLP-III), 4-[4-(9-phenyl-9H-fluoren-9-yl)phenyl]-6-phenyldibenzothiophene (abbreviation: DBTFLP-IV), and other compounds having a thiophene skeleton such as, 4,4',4''-(benzene-1,3,Examples of compounds having a furan skeleton include 5-triyl)tri(dibenzofuran) (abbreviation: DBF3P-II) and 4-{3-[3-(9-phenyl-9H-fluoren-9-yl)phenyl]phenyl}dibenzofuran (abbreviation: mmDBFFLBi-II). Among those mentioned above, compounds having an aromatic amine skeleton and compounds having a carbazole skeleton are preferred because they have good reliability, high hole transport properties, and contribute to reducing the driving voltage. Furthermore, the organic compounds listed as hole transporting substances used in the composite material of layer 104X can also be suitably used as materials constituting layer 112X.

[0247] <Example of the composition of layer 111X> It is preferable that layer 111X has a composition that includes a material having luminescence properties. Layer 111X is a layer containing a luminescent central material. It is also preferable that it further includes a host material.

[0248] The luminescent central material may be a fluorescent material, a phosphorescent material, a thermally activated delayed fluorescence (TADF) material, or any other luminescent material.

[0249] In one embodiment of the present invention, the following are examples of materials that can be used as fluorescent luminescent materials in the light-emitting layer. Other fluorescent luminescent materials can also be used.

[0250] 5,6-bis[4-(10-phenyl-9-antryl)phenyl]-2,2'-bipyridine (abbreviation: PAPP2BPy), 5,6-bis[4'-(10-phenyl-9-antryl)biphenyl-4-yl]-2,2'-bipyridine (abbreviation: PAPP2BPy), N,N'-diphenyl-N,N'-bis[4-(9-phenyl-9H-fluoren-9-yl)phenyl]pyrene-1,6-diamine (abbreviation: 1,6FLPAPrn), N,N'-bis(3-methylphenyl)-N,N'-bis[3-(9-phenyl-9H- Fluoren-9-yl)phenyl]pyrene-1,6-diamine (abbreviation: 1,6mMemFLPAPrn), N,N'-bis[4-(9H-carbazole-9-yl)phenyl]-N,N'-diphenylstilbene-4,4'-diamine (abbreviation: YGA2S), 4-(9H-carbazole-9-yl)-4'-(10-phenyl-9-antryl)triphenylamine (abbreviation: YGAPA), 4-(9H-carbazole-9-yl)-4'-(9,10-diphenyl-2-antryl)triphenylamine (abbreviation: 2YGA PPA), N,9-diphenyl-N-[4-(10-phenyl-9-anthryl)phenyl]-9H-carbazole-3-amine (abbreviation: PCAPA), perylene, 2,5,8,11-tetra-tert-butylperylene (abbreviation: TBP), 4-(10-phenyl-9-anthryl)-4'-(9-phenyl-9H-carbazole-3-yl)triphenylamine (abbreviation: PCBAPA), N,N''-(2-tert-butylanthracene-9,10-diyldi-4,1-phenylene)bis(N,N',N'-triphenyl Nyl-1,4-phenylenediamine) (abbreviation: DPABPA), N,9-diphenyl-N-[4-(9,10-diphenyl-2-antryl)phenyl]-9H-carbazole-3-amine (abbreviation: 2PCAPPA), N,N'-diphenyl-N,N'-(1,6-pyrene-diyl)bis[(6-phenylbenzo[b]naphtho[1,2-d]furan)-8-amine] (abbreviation: 1,6BnfAPrn-03), N,N'-diphenyl-N,N'-bis(9-phenyl-9H-carbazole-2-yl)naphtho[2,3-b;Materials that exhibit blue luminescence, such as 6,7-b']bisbenzofuran-3,10-diamine (abbreviation: 3,10PCA2Nbf(IV)-02), 3,10-bis[N-(dibenzofuran-3-yl)-N-phenylamino]naphtho[2,3-b;6,7-b']bisbenzofuran (abbreviation: 3,10FrA2Nbf(IV)-02), N-[4-(9,10-diphenyl-2-antryl)phenyl]- N,N',N'-triphenyl-1,4-phenylenediamine (abbreviation: 2DPAPPA), N,N,N',N',N'',N'',N''',N'''-octaphenyldibenzo[g,p]chrysene-2,7,10,15-tetraamine (abbreviation: DBC1), coumarin 30, N-(9,10-diphenyl-2-anthryl)-N,9-diphenyl-9H-carbazole-3-amine (abbreviation: 2PCAP) A), N-[9,10-bis(biphenyl-2-yl)-2-anthryl]-N,9-diphenyl-9H-carbazole-3-amine (abbreviation: 2PCABPhA), N-(9,10-diphenyl-2-anthryl)-N,N',N'-triphenyl-1,4-phenylenediamine (abbreviation: 2DPAPA), N-[9,10-bis(biphenyl-2-yl)-2-anthryl]-N,N',N'-trif Examples include materials that exhibit green luminescence, such as phenyl-1,4-phenylenediamine (abbreviated as 2DPABPhA), 9,10-bis(biphenyl-2-yl)-N-[4-(9H-carbazole-9-yl)phenyl]-N-phenylanthracene-2-amine (abbreviated as 2YGABPhA), N,N,9-triphenylanthracene-9-amine (abbreviated as DPhAPhA), and coumarin 545T. In particular, condensed aromatic diamine compounds, such as pyrenediamine compounds like 1,6FLPAAPrn, 1,6mMemFLPAAPrn, and 1,6BnfAPrn-03, are preferred due to their high hole-trapping properties and excellent luminescence efficiency or reliability.

[0251] Also, 5,9-diphenyl-5,9-diaza-13b-boranaphtho[3,2,1-de]anthracene (abbreviation: DABNA1), 9-(biphenyl-3-yl)-N,N,5,11-tetraphenyl-5H,9H-[1,4]benzazaborino[2,3,4-kl]phenazavolin-3-amine (abbreviation: DABNA2), 2,12-di(tert-butyl)-5,9-di(4-tert-butylphenyl)-N,N-diphenyl-5H,9H-[1,4]benzazaborino[2,3,4-kl]phenazavolin-7- Amine (abbreviation: DPhA-tBu4DABNA), 2,12-di(tert-butyl)-N,N,5,9-tetra(4-tert-butylphenyl)-5H,9H-[1,4]benzazabolino[2,3,4-kl]phenazavolin-7-amine (abbreviation: tBuDPhA-tBu4DABNA), 2,12-di(tert-butyl)-5,9-di(4-tert-butylphenyl)-7-methyl-5H,9H-[1,4]benzazabolino[2,3,4-kl]phenazavolin (abbreviation: Me-tBu4DABNA), N ７ , N ７ , N １３ , N １３ Condensed heteroaromatic compounds containing nitrogen and boron, such as 5,9,11,15-octaphenyl-5H,9H,11H,15H-[1,4]benzazabolino[2,3,4-kl][1,4]benzazabolino[4',3',2':4,5][1,4]benzazabolino[3,2-b]phenazabolin-7,13-diamine (abbreviation: ν-DABNA) and 2-(4-tert-butylphenyl)benz[5,6]indro[3,2,1-jk]benzo[b]carbazole (abbreviation: tBuPBibc), particularly compounds having a diazaboranaphtho-anthracene skeleton, can be suitably used because they produce blue emission with a narrow emission spectrum and good color purity.

[0252] In addition to these, 9,10,11-tris[3,6-bis(1,1-dimethylethyl)-9H-carbazolyl-9-yl]-2,5,15,18-tetrakis(1,1-dimethylethyl)indoro[3,2,1-de]indoro[3',2',1':8,1][1,4]benzazaborino[2,3,4-kl]phenazavolin (abbreviation: BBCz-G), 9,11-bis[ Compounds having an indole skeleton, such as 3,6-bis(1,1-dimethylethyl)-9H-carbazolyl-9-yl]-2,5,15,18-tetrakis(1,1-dimethylethyl)indro[3,2,1-de]indro[3',2',1':8,1][1,4]benzazavolino[2,3,4-kl]phenazavolin (abbreviation: BBCz-Y), can be suitably used.

[0253] In the light-emitting layer, suitable phosphorescent materials that can be used as the light-emitting central material include metal complexes, particularly iridium complexes or platinum complexes, and examples include the following.

[0254] Tris{2-[5-(2-methylphenyl)-4-(2,6-dimethylphenyl)-4H-1,2,4-triazole-3-yl-κN2]phenyl-κC}Iridium(III) (Abbreviation: [Ir(mpptz-dmp) ３ ]), Tris(5-methyl-3,4-diphenyl-4H-1,2,4-triazolato) iridium (III) (abbreviation: [Ir(Mptz) ３ ]), organometallic iridium complexes having a 4H-triazole skeleton such as tris[3-methyl-1-(2-methylphenyl)-5-phenyl-1H-1,2,4-triazolato]iridium(III) (abbreviation: [Ir(Mptz1-mp) ３ ]), Tris(1-methyl-5-phenyl-3-propyl-1H-1,2,4-triazolato) Iridium(III) (abbreviation: [Ir(Prptz1-Me) ３ ]) an organometallic iridium complex having a 1H-triazole skeleton, such as fac-tris[1-(2,6-diisopropylphenyl)-2-phenyl-1H-imidazole]iridium(III) (abbreviation: [Ir(iPrpim) ３]), Tris[3-(2,6-dimethylphenyl)-7-methylimidazo[1,2-f]phenanthridine]iridium(III) (abbreviation: [Ir(dmpimpt-Me) ３ ]), organometallic iridium complexes having an imidazole skeleton such as tris(2-{1-[2,6-bis(1-methylethyl)phenyl]-1H-imidazole-2-yl-κN3}-4-cyanophenyl-κC) iridium(III) (abbreviation: CNImIr), tris[(6-tert-butyl-3-phenyl-2H-imidazol[4,5-b]pyrazine-1-yl-κC2)phenyl-κC] iridium(III) (abbreviation: [Ir(cb) ３ Organometallic complexes having a benzimidazolidene skeleton such as ]), bis[2-(4',6'-difluorophenyl)pyridinato-N,C ２’ Iridium(III) tetrakis(1-pyrazolyl) borate (abbreviation: FIr6), bis[2-(4',6'-difluorophenyl)pyridinate-N,C ２’ Iridium(III) picolinate (abbreviation: FIrpic), bis{2-[3',5'-bis(trifluoromethyl)phenyl]pyridinate-N,C ２’ Iridium (III) picolinate (abbreviation: [Ir(CF) ３ ppy) ２ (pic)]), bis[2-(4',6'-difluorophenyl)pyridinate-N,C ２’ Examples include organometallic iridium complexes with phenylpyridine derivatives having electron-withdrawing groups, such as iridium(III) acetylacetonate (abbreviated as FIracac), and platinum complexes such as (2-{3-[3-(3,5-di-tert-butylphenyl)benzimidazole-1-yl-2-ylidene-κC2]phenoxy-κC2}-9-(4-tert-butyl-2-pyridinyl-κN)carbazole-2,1-diyl-κC1)platinum(II) (abbreviated as PtON-TBBI). These compounds exhibit phosphorescence with a blue hue and have emission peaks in the wavelength range from 450 nm to 520 nm. Compounds in which some of the hydrogen atoms in these compounds are replaced with deuterium can also be used.

[0255] Also, tris(4-methyl-6-phenylpyrimidinato)iridium(III) (abbreviation: [Ir(mppm) ３ ]), Tris(4-t-butyl-6-phenylpyrimidinato)iridium(III) (abbreviation: [Ir(tBuppm) ３ ]), (acetylacetonato)bis(6-methyl-4-phenylpyrimidinato)iridium(III) (abbreviation: [Ir(mppm) ２ (acac)), (acetylacetonato)bis(6-tert-butyl-4-phenylpyrimidinato)iridium(III) (abbreviation: [Ir(tBuppm) ２ (acac)), (acetylacetonate)bis[6-(2-norbornyl)-4-phenylpyrimidinato]iridium(III) (abbreviation: [Ir(nbppm) ２ (acac)), (acetylacetonato)bis[5-methyl-6-(2-methylphenyl)-4-phenylpyrimidinato]iridium(III) (abbreviation: [Ir(mpmpppm) ２ (acac)), (acetylacetonato)bis(4,6-diphenylpyrimidinato)iridium(III) (abbreviation: [Ir(dppm) ２ Organometallic iridium complexes having a pyrimidine skeleton such as (acac) (acetylacetonato)bis(3,5-dimethyl-2-phenylpyradinato)iridium(III) (abbreviation: [Ir(mppr-Me) ２ (acac)), (acetylacetonato)bis(5-isopropyl-3-methyl-2-phenylpyradinato)iridium(III) (abbreviation: [Ir(mppr-iPr) ２ Organometallic iridium complexes having a pyrazine skeleton such as (acac), Tris(2-phenylpyridinato-N,C) ２’ Iridium (III) (abbreviation: [Ir(ppy) ３ ]), bis(2-phenylpyridinate-N,C ２’ Iridium (III) acetylacetonate (abbreviation: [Ir(ppy) ２ (acac)), bis(benzo[h]quinolinate)iridium(III)acetylacetonate (abbreviation: [Ir(bzq) ２(acac)]), tris(benzo[h]quinolinato)iridium(III) (abbreviation: [Ir(bzq) ３ ), tris(2-phenylquinolinato-N,C ２’ )iridium(III) (abbreviation: [Ir(pq) ３ ), bis(2-phenylquinolinato-N,C ２’ )iridium(III) acetylacetonate (abbreviation: [Ir(pq) ２ (acac)]), [2-d3-methyl-8-(2-pyridinyl-κN)benzofuro[2,3-b]pyridine-κC]bis[2-(5-d ３ -methyl-2-pyridinyl-κN2)phenyl-κC]iridium(III) (abbreviation: Ir(5mppy-d ３ ) ２ (mbfpyypy-d ３ )), {2-(methyl-d ３ )-8-[4-(1-methylethyl-1-d)-2-pyridinyl-κN]benzofuro[2,3-b]pyridin-7-yl-κC}bis{5-(methyl-d ３ )-2-[5-(methyl-d ３ )-2-pyridinyl-κN]phenyl-κC}iridium(III) (abbreviation: Ir(5mtpy-d6) ２ (mbfpyypy-iPr-d ４ )), [2-d ３ -methyl-(2-pyridinyl-κN)benzofuro[2,3-b]pyridine-κC]bis[2-(2-pyridinyl-κN)phenyl-κC]iridium(III) (abbreviation: Ir(ppy) ２ (mbfpyypy-d ３ )), [2-(4-methyl-5-phenyl-2-pyridinyl-κN)phenyl-κC]bis[2-(2-pyridinyl-κN)phenyl-κC]iridium(III) (abbreviation: Ir(ppy) ２ (mdppy)), [2-(4-d ３ -methyl-5-phenyl-2-pyridinyl-κN2)phenyl-κC]bis[2-(5-d ３ -methyl-2-pyridinyl-κN2)phenyl-κC]iridium(III) (abbreviation: [Ir(5mppy-d ３ )2(mdppy-d３ ) )]), [2-methyl-(2-pyridinyl-κN)benzofl[2,3-b]pyridine-κC]bis[2-(2-pyridinyl-κN)phenyl-κC]iridium(III) (abbreviation: [Ir(ppy) ２ (mbfpypy))]), [2-(4-methyl-5-phenyl-2-pyridinyl-κN)phenyl-κC]bis[2-(2-pyridinyl-κN)phenyl-κC]iridium (abbreviation: [Ir(ppy) ２ (mdppy)]), Tris{2-[5-(methyl-d3)-4-phenyl-2-pyridinyl-κN]phenyl-κC}Iridium(III) (abbreviation: Ir(5m4dppy-d ３ ) ３ In addition to organometallic iridium complexes with a pyridine skeleton such as tris(acetylacetonato)(monophenanthroline)terbium(III) (abbreviation: [Tb(acac) ３ Rare earth metal complexes such as (Phen) (2-{1-(5-tert-butylbiphenyl-2-yl)-4-[3-tert-butyl-5-(4-phenyl-2-pyridinyl-κN)phenyl-κC6]-2-benzimidazolyl-κN3}-4,6-di-tert-butylphenolate-κO)platinum(II) (abbreviation: Pt(tBudpppymmtBubiz-tBubp) Examples of organometallic platinum complexes include [2-(4-(3,5-di-tert-butylphenyl)-6-{3-[4-(5'-tert-butyl[1,1':3',1''-terphenyl]-2'-yl)-2-pyridinyl-κN]phenyl-κC2}-2-pyridinyl-κN)phenolato-κO]platinum(II) (abbreviation: Pt(4tButpppypyp-mmtBup)). These compounds mainly exhibit phosphorescence with a green hue and have emission peaks in the wavelength range from 500 nm to 600 nm. Organometallic iridium complexes with a pyrimidine skeleton are particularly preferred due to their outstanding reliability and luminescence efficiency. Compounds in which some of the hydrogen atoms are replaced with deuterium can also be used.

[0256] In addition to the phosphorescent compounds described above, other known phosphorescent compounds may be selected and used.

[0257] As TADF materials, fullerenes and their derivatives, acridines and their derivatives, eosin derivatives, etc. can be used. Also, metal-containing porphyrins containing magnesium (Mg), zinc (Zn), cadmium (Cd), tin (Sn), platinum (Pt), indium (In), or palladium (Pd) can be used. As a metal-containing porphyrin, for example, the protoporphyrin-tin fluoride complex (SnF) shown in the following structural formula is used. ２ (Proto IX)), Mesoporphyrin-Tin Fluoride Complex (SnF ２ (Meso IX), hematoporphyrin-tin fluoride complex (SnF ２ (Hemato IX), coproporphyrin tetramethyl ester-tin fluoride complex (SnF ２ (Copro III-4Me)), Octaethylporphyrin-Tin Fluoride Complex (SnF ２ (OEP)), Ethioporphyrin-Tin Fluoride Complex (SnF ２ (Etio I)), Octaethylporphyrin-Platinum Chloride Complex (PtCl ２ OEP (Open Economic Programme) and others can also be mentioned.

[0258]

[0259] Furthermore, the following structural formulas represent 2-(biphenyl-4-yl)-4,6-bis(12-phenylindoro[2,3-a]carbazole-11-yl)-1,3,5-triazine (abbreviation: PIC-TRZ), 9-(4,6-diphenyl-1,3,5-triazine-2-yl)-9'-phenyl-9H,9'H-3,3'-bicarbazole (abbreviation: PCCzTZn), 2-{4-[3-(N-phenyl-9H-carbazole-3-yl)-9H-carbazole-9-yl]phenyl}-4,6-diphenyl-1,3,5-triazine (abbreviation: PCCzPTZn), 2-[4-(10H-phenoxazine-10-yl)phenyl]-4,6-diphenyl-1,3,5-triazine (abbreviation: PCCzPTZn), Heterocyclic compounds having one or both of a π-electron-rich heteroaromatic ring and a π-electron-deficient heteroaromatic ring can also be used, such as PXZ-TRZ), 3-[4-(5-phenyl-5,10-dihydrophenadin-10-yl)phenyl]-4,5-diphenyl-1,2,4-triazole (abbreviated as PPZ-3TPT), 3-(9,9-dimethyl-9H-acridine-10-yl)-9H-xanthene-9-one (abbreviated as ACRXTN), bis[4-(9,9-dimethyl-9,10-dihydroacridine)phenyl]sulfone (abbreviated as DMAC-DPS), and 10-phenyl-10H,10'H-spiro[acridine-9,9'-anthracene]-10'-one (abbreviated as ACRSA). The heterocyclic compound is preferred because it has both a π-electron-excess heteroaromatic ring and a π-electron-deficient heteroaromatic ring, resulting in high electron transport and hole transport properties. Among the skeletons having a π-electron-deficient heteroaromatic ring, the pyridine skeleton, diazine skeleton (pyrimidine skeleton, pyrazine skeleton, pyridazine skeleton), and triazine skeleton are preferred because they are stable and reliable. In particular, the benzoflopyrimidine skeleton, benzothienopyrimidine skeleton, benzoflopyrazine skeleton, and benzothienopyrazine skeleton are preferred because they have high acceptability and are reliable. Furthermore, among the skeletons having a π-electron-excess heteroaromatic ring, the acridine skeleton, phenoxazine skeleton, phenothiazine skeleton, furan skeleton, thiophene skeleton, and pyrrole skeleton are preferred because they are stable and reliable, and therefore it is preferable to have at least one of these skeletons.Furthermore, a dibenzofuran skeleton is preferred as the furan skeleton, and a dibenzothiophene skeleton is preferred as the thiophene skeleton. In addition, as the pyrrole skeleton, indole skeleton, carbazole skeleton, indrocarbazole skeleton, bicarbazole skeleton, and 3-(9-phenyl-9H-carbazole-3-yl)-9H-carbazole skeleton are particularly preferred. Substances in which a π-electron-rich heteroaromatic ring and a π-electron-deficient heteroaromatic ring are directly bonded are particularly preferred because both the electron-donating and electron-accepting properties of the π-electron-rich heteroaromatic ring are strengthened, and the energy difference between the S1 and T1 levels is reduced, thus efficiently obtaining thermally activated delayed fluorescence. In addition, an aromatic ring to which an electron-withdrawing group such as a cyano group is bonded may be used instead of the π-electron-deficient heteroaromatic ring. Furthermore, aromatic amine skeletons, phenazine skeletons, etc., can be used as the π-electron-rich skeleton. Furthermore, as π-electron-deficient skeletons, xanthene skeletons, thioxanthene dioxide skeletons, oxadiazole skeletons, triazole skeletons, imidazole skeletons, anthraquinone skeletons, boron-containing skeletons such as phenylborane and volanthrene, aromatic rings having a nitrile group or a cyano group such as benzonitrile or cyanobenzene, heteroaromatic rings, carbonyl skeletons such as benzophenone, phosphine oxide skeletons, sulfone skeletons, etc., can be used. In this way, π-electron-deficient skeletons and π-electron-excess skeletons can be used instead of at least one of π-electron-deficient heteroaromatic rings and π-electron-excess heteroaromatic rings.

[0260]

[0261] Furthermore, a TADF material in which the singlet excited state and the triplet excited state are in thermal equilibrium may be used as the TADF material. Since such a TADF material has a shorter luminescence lifetime (excitation lifetime), it is possible to suppress the decrease in efficiency in the high-brightness region of the light-emitting device. Specifically, materials with the molecular structure shown below are examples.

[0262]

[0263] TADF materials are materials that have a small difference between the S1 and T1 energy levels and possess the ability to convert energy from triplet excitation energy to singlet excitation energy through reverse intersystem crossing. Therefore, triplet excitation energy can be upconverted to singlet excitation energy with only a small amount of thermal energy (reverse intersystem crossing), and singlet excited states can be efficiently generated. Furthermore, triplet excitation energy can be converted into luminescence.

[0264] Furthermore, an excited complex (also called an exciplex) formed by two different substances has an extremely small difference between the S1 and T1 levels and functions as a TADF material capable of converting triplet excitation energy into singlet excitation energy.

[0265] Furthermore, the phosphorescence spectrum observed at low temperatures (for example, from 77K to 10K) can be used as an indicator of the T1 level. For TADF materials, when a tangent is drawn at the short-wavelength tail of the fluorescence spectrum and the energy at the wavelength of the extrapolation is taken as the S1 level, and when a tangent is drawn at the short-wavelength tail of the phosphorescence spectrum and the energy at the wavelength of the extrapolation is taken as the T1 level, it is preferable that the difference between S1 and T1 is 0.3 eV or less, and more preferably 0.2 eV or less.

[0266] Furthermore, when using TADF material as a light-emitting material, it is preferable that the S1 level of the host material is higher than the S1 level of the TADF material. Also, it is preferable that the T1 level of the host material is higher than the T1 level of the TADF material.

[0267] Various carrier transport materials can be used as the host material for the light-emitting layer, such as materials with electron transport properties and / or hole transport properties, and the TADF material mentioned above.

[0268] Preferred materials with hole transport properties include organic compounds having an amine skeleton or a π-electron-rich heteroaromatic ring skeleton. Preferred π-electron-rich heteroaromatic rings are condensed aromatic rings containing at least one of the following: acridine skeleton, phenoxazine skeleton, phenothiazine skeleton, furan skeleton, thiophene skeleton, and pyrrole skeleton. Specifically, carbazole rings, dibenzothiophene rings, or rings obtained by further condensing an aromatic ring or heteroaromatic ring with these are preferred.

[0269] Organic compounds having such hole-transporting properties more preferably have at least one of the following skeletons: a carbazole skeleton, a dibenzofuran skeleton, a dibenzothiophene skeleton, and an anthracene skeleton. In particular, they may be aromatic amines having substituents including a dibenzofuran ring or a dibenzothiophene ring, aromatic monoamines having a naphthalene ring, or aromatic monoamines in which a 9-fluorenyl group is bonded to the nitrogen of the amine via an arylene group. Furthermore, it is preferable that these hole-transporting organic compounds are substances having an N,N-bis(4-biphenyl)amino group, as this allows for the creation of light-emitting devices with a good lifetime.

[0270] Preferred organic compounds include, for example, the following: 4,4'-bis[N-(1-naphthyl)-N-phenylamino]biphenyl (abbreviated as NPB), N,N'-diphenyl-N,N'-bis(3-methylphenyl)-4,4'-diaminobiphenyl (abbreviated as TPD), N,N'-bis(9,9'-spirobi[9H-fluoren]-2-yl)-N,N'-diphenyl-4,4'-diaminobiphenyl (abbreviated as BSPB), 4-phenyl-4'-(9-phenylfluoren-9-yl)triphenylamine (abbreviated as BPAFLP), 4-phenyl-3'-(9-phenylfluoren-9- 4,4'-(9-phenyl-9H-carbazole-3-yl)triphenylamine (abbreviation: mBPAFLP), 4,4'-diphenyl-4''-(9-phenyl-9H-carbazole-3-yl)triphenylamine (abbreviation: PCBA1BP), 4,4'-diphenyl-4''-(9-phenyl-9H-carbazole-3-yl)triphenylamine (abbreviation: PCBi1BP), 4-(1-naphthyl)-4'-(9-phenyl-9H-carbazole-3-yl)triphenylamine (abbreviation: PCBANB), 4,4'-di(1-naphthyl)-4''-(9-phenyl-9H-carbazole-3-yl ) Compounds having an aromatic amine skeleton such as triphenylamine (abbreviation: PCBNBB), 9,9-dimethyl-N-phenyl-N-[4-(9-phenyl-9H-carbazole-3-yl)phenyl]fluoren-2-amine (abbreviation: PCBAF), N-phenyl-N-[4-(9-phenyl-9H-carbazole-3-yl)phenyl]-9,9'-spirobi[9H-fluoren]-2-amine (abbreviation: PCBASF), 1,3-bis(N-carbazolyl)benzene (abbreviation: mCP), 4,4'-di(N-carbazolyl)biphenyl ( Abbreviation: CBP), 3,6-bis(3,5-diphenylphenyl)-9-phenylcarbazole (abbreviation: CzTP), 3,3'-bis(9-phenyl-9H-carbazole) (abbreviation: PCCP), 3,9-bis(9-phenyl-9H-carbazole-3-yl)-9H-carbazole (abbreviation: PCCzPC), 9-(biphenyl-4-yl)-9'-phenyl-3,3'-bi-9H-carbazole (abbreviation: PCCzBP), 9,9'-bis(biphenyl-4-yl)-3,3'-bi-9H-carbazole (abbreviation: BisBPCz), 9,9'-Bis(biphenyl-3-yl)-3,3'-bi-9H-carbazole (abbreviation: BismBPCz), 9-(biphenyl-3-yl)-9'-(biphenyl-4-yl)-9H,9'H-3,3'-bicarbazole (abbreviation: mBPCCBP), 9-(2-naphthyl)-9'-phenyl-3,3'-bi-9H-carbazole (abbreviation: βNCCP), 9-(3-biphenyl)-9'-(2-naphthyl)-3,3'-bi-9H-carbazole (abbreviation: βNCCmBP), 9-(4-biphenyl)-9'-(2-naphthyl)-3, 3'-bi-9H-carbazole (abbreviation: βNCCBP), 9,9'-di-2-naphthyl-3,3'-9H,9'H-bicarbazole (abbreviation: BisβNCz), 9-(2-naphthyl)-9'-[1,1':4',1"-terphenyl]-3-yl-3,3'-9H,9'H-bicarbazole, 9-(2-naphthyl)-9'-[1,1':3',1"-terphenyl]-3-yl-3,3'-9H,9'H-bicarbazole, 9-(2-naphthyl)-9'-[1,1':3',1"-terphenyl]-5'-yl-3,3'-9H ,9'H-bicarbazole, 9-(2-naphthyl)-9'-[1,1':4',1"-terphenyl]-4-yl-3,3'-9H,9'H-bicarbazole, 9-(2-naphthyl)-9'-[1,1':3',1"-terphenyl]-4-yl-3,3'-9H,9'H-bicarbazole, 9-(2-naphthyl)-9'-(triphenylene-2-yl)-3,3'-9H,9'H-bicarbazole, 9-phenyl-9'-(triphenylene-2-yl)-3,3'-9H,9'H-bicarbazole (abbreviation: PCCzTp), 9,9'-bis(triphenylene-2-yl)-3,3'-9H,9'H-bicarbazole, 9-(4-biphenyl)-9'-(triphenylene-2-yl)-3,3'-9H,9'H-bicarbazole, 9-(triphenylene-2-yl)-9'-[1,1':3',1''-terphenyl]-4-yl-3,3'-9H,9'H-bicarbazole, N,N-bis(9,9-dimethyl-9H-fluoren-2-yl)-9,9'-spirobi-9H-fluoren-1-amine, 9-[3-(triphenylsilyl)phenyl]-3,Compounds having a carbazole skeleton such as 9'-bi-9H-carbazole (abbreviation: PSiCzCz), 9'-[3-(triphenylsilyl)phenyl]-9'H-9,3':6',9''-telcarbazole (abbreviation: PSiCzGI), 4,4',4''-(benzene-1,3,5-triyl)tri(dibenzothiophene) (abbreviation: DBT3P-II), 2,8-diphenyl-4-[4-(9-phenyl-9H-fluoren-9-yl)phenyl]dibenzothiophene (abbreviation: DBTFLP-I) Examples include compounds having a thiophene skeleton such as 4-[4-(9-phenyl-9H-fluoren-9-yl)phenyl]-6-phenyldibenzothiophene (abbreviated as DBTFLP-IV), and compounds having a furan skeleton such as 4,4',4''-(benzene-1,3,5-triyl)tri(dibenzofuran) (abbreviated as DBF3P-II) and 4-{3-[3-(9-phenyl-9H-fluoren-9-yl)phenyl]phenyl}dibenzofuran (abbreviated as mmDBFFLBi-II). Among the above, compounds having an aromatic amine skeleton or a carbazole skeleton are preferred because they have good reliability, high hole transportability, and contribute to reducing the driving voltage. In addition, organic compounds listed as examples of hole transportable materials in the hole transport layer can also be used. Furthermore, it is more preferable to use organic compounds having an amine skeleton or a fluorene skeleton. Furthermore, organic compounds having amine and fluorene skeletons are preferred because they are highly reliable and have high hole transport properties, thereby reducing the power consumption of light-emitting devices.

[0271] For materials exhibiting electron transport properties, the electron mobility at which the square root of the electric field strength [V / cm] is 600 is 1 × 10⁻⁶. −７ cm ２ / Vs or more, preferably 1 x 10 −６ cm ２ A material having an electron mobility of / Vs or higher is preferred. However, any material with higher electron transport capabilities than holes can be used.

[0272] Examples of electron-transporting materials include bis(10-hydroxybenzo[h]quinolinato)beryllium(II) (abbreviated as BeBq). ２Preferably, metal complexes such as bis(2-methyl-8-quinolinolato)(4-phenylphenololato)aluminum(III) (abbreviated as BAlq), bis(8-quinolinolato)zinc(II) (abbreviated as Znq), bis[2-(2-benzoxazollyl)phenololato]zinc(II) (abbreviated as ZnPBO), and bis[2-(2-benzothiazolyl)phenololato]zinc(II) (abbreviated as ZnBTZ), and organic compounds having a π-electron-deficient heteroaromatic ring are preferred. Examples of organic compounds having a π-electron-deficient heteroaromatic ring skeleton include organic compounds containing a heteroaromatic ring having an azole skeleton, organic compounds containing a heteroaromatic ring having a pyridine skeleton, organic compounds containing a heteroaromatic ring having a diazine skeleton, and organic compounds containing a heteroaromatic ring having a triazine skeleton.

[0273] Among these, organic compounds containing heteroaromatic rings having a diazine skeleton (pyrimidine skeleton, pyrazine skeleton, pyridazine skeleton), organic compounds containing heteroaromatic rings having a pyridine skeleton, and organic compounds containing heteroaromatic rings having a triazine skeleton are preferred due to their good reliability. In particular, organic compounds containing heteroaromatic rings having a diazine (pyrimidine or pyrazine) skeleton and organic compounds containing heteroaromatic rings having a triazine skeleton have high electron transport properties and contribute to reducing the driving voltage. Furthermore, benzoflopyrimidine skeletons, benzothienopyrimidine skeletons, benzoflopyrazine skeletons, and benzothienopyrazine skeletons are preferred because they have high acceptor properties and good reliability.

[0274] As organic compounds having a π-electron-deficient heteroaromatic ring skeleton, the following organic compounds are preferred, for example: 2-(4-biphenylyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole (abbreviation: PBD), 3-(4-biphenylyl)-4-phenyl-5-(4-tert-butylphenyl)-1,2,4-triazole (abbreviation: TAZ), 1,3-bis[5-(p-tert-butylphenyl)-1,3,4-oxadiazole-2-yl]benzene (abbreviation: OXD-7), 9-[4-(5-phenyl-1,3,4-oxadiazole-2-yl)phenyl]-9H-carbazole (abbreviation: Organic compounds having an azole skeleton such as CO11), 2,2',2''-(1,3,5-benzenetriyl)tris(1-phenyl-1H-benzimidazole) (abbreviation: TPBI), 2-[3-(dibenzothiophen-4-yl)phenyl]-1-phenyl-1H-benzimidazole (abbreviation: mDBTBIm-II), 4,4'-bis(5-methylbenzoxazole-2-yl)stilbene (abbreviation: BzOs), and 3,5-bis[3-(9H-carbazole-9-yl)phenyl]pyridine (abbreviation: 35 DCzPPy), 1,3,5-tri[3-(3-pyridyl)phenyl]benzene (abbreviation: TmPyPB), vasophenanthroline (abbreviation: Bphen), vasocuproin (abbreviation: BCP), 2,9-di(naphthalene-2-yl)-4,7-diphenyl-1,10-phenanthroline (abbreviation: NBphen), 2,2'-(1,3-phenylene)bis(9-phenyl-1,10-phenanthroline) (abbreviation: mPPhen2P), 2-[3-(2-triphenylenyl)phenyl]-1,10-phenanthroline Organic compounds containing heteroaromatic rings with a pyridine skeleton, such as 2-phenyl-9-(2-triphenylenyl)-1,10-phenanthroline (abbreviation: Ph-TpPhen), 2-[4-(9-phenantrenyl)-1-naphthalenyl]-1,10-phenanthroline (abbreviation: PnNPhen), and 2-[4-(2-triphenylenyl)phenyl]-1,10-phenanthroline (abbreviation: pTpPPhen), 2-[3-(dibenzothiophen-4-yl)phenyl]dibenzo[f,[h]Quinoxaline (abbreviation: 2mDBTPDBq-II), 2-[3'-(dibenzothiophen-4-yl)biphenyl-3-yl]dibenzo[f,h]Quinoxaline (abbreviation: 2mDBTPDBq-II), 2-[3'-(9H-carbazole-9-yl)biphenyl-3-yl]dibenzo[f,h]Quinoxaline (abbreviation: 2mCzBPDBq), 2-[4'-(9-phenyl-9H-carbazole-3-yl)-3,1'-biphenyl-1-yl]dibenzo[f,h]Quinoxaline (abbreviation: 2mpPCBPDBq), 2-[4-(3,6-diphenyl [Lu-9H-carbazole-9-yl)phenyl]dibenzo[f,h]quinoxaline (abbreviation: 2CzPDBq-III), 7-[3-(dibenzothiophen-4-yl)phenyl]dibenzo[f,h]quinoxaline (abbreviation: 7mDBTPDBq-II), and 6-[3-(dibenzothiophen-4-yl)phenyl]dibenzo[f,h]quinoxaline (abbreviation: 6mDBTPDBq-II), 9-[3'-(dibenzothiophen-4-yl)biphenyl-3-yl]naphtho[1',2':4,5]flo[2,3-b]pyrazine (abbreviation: 9mDBtBPNF pr), 9-[3'-(dibenzothiophen-4-yl)biphenyl-4-yl]naphtho[1',2':4,5]flo[2,3-b]pyrazine (abbreviation: 9pmDBtBPNfpr), 4,6-bis[3-(phenanthren-9-yl)phenyl]pyrimidine (abbreviation: 4,6mPnP2Pm), 4,6-bis[3-(dibenzothiophen-4-yl)phenyl]pyrimidine (abbreviation: 4,6mDBTP2Pm-II), 4,6-bis[3-(9H-carbazole-9-yl)phenyl]pyrimidine (abbreviation: 4,6mCzP2Pm), 9,9'-[pyrimidine n-4,6-diylbis(biphenyl-3,3'-diyl)]bis(9H-carbazole) (abbreviation: 4,6mCzBP2Pm), 8-(biphenyl-4-yl)-4-[3-(dibenzothiophen-4-yl)phenyl]-[1]benzoflo[3,2-d]pyrimidine (abbreviation: 8BP-4mDBtPBfpm), 3,8-bis[3-(dibenzothiophen-4-yl)phenyl]benzoflo[2,3-b]pyrazine (abbreviation: 3,8mDBtP2Bfpr), 4,8-bis[3-(dibenzothiophen-4-yl)phenyl]-[1]benzoflo[3,2-d]pyrimidine (abbreviation: 4,8mDBtP2Bfpm), 8-[3'-(dibenzothiophen-4-yl)(biphenyl-3-yl)]naphtho[1',2':4,5]flo[3,2-d]pyrimidine (abbreviation: 8mDBtBPNfpm), 8-[(2,2'-binaphthalene)-6-yl]-4-[3-(dibenzothiophen-4-yl)phenyl]-[1]benzoflo[3,2-d]pyrimidine (abbreviation: 8(βN2)-4mDBtPBfpm), 2,2'-(pyridine-2,6-diyl)bis(4-phenylbenzo[h]quinazoline) (abbreviation: 2, 6(P-Bqn)2Py), 2,2'-(pyridine-2,6-diyl)bis{4-[4-(2-naphthyl)phenyl]-6-phenylpyrimidine} (abbreviation: 2,6(NP-PPm)2Py), 6-(biphenyl-3-yl)-4-[3,5-bis(9H-carbazole-9-yl)phenyl]-2-phenylpyrimidine (abbreviation: 6mBP-4Cz2PPm), 2,6-bis(4-naphthalene-1-ylphenyl)-4-[4-(3-pyridyl)phenyl]pyrimidine (abbreviation: 2,4NP-6PyPPm), 4-[3,5-bis(9H-carbazole-9 -yl)phenyl]-2-phenyl-6-(biphenyl-4-yl)pyrimidine (abbreviation: 6BP-4Cz2PPm), 7-[4-(9-phenyl-9H-carbazole-2-yl)quinazoline-2-yl]-7H-dibenzo[c,g]carbazole (abbreviation: PC-cgDBCzQz), 8-(p-terphenyl-3-yl)-4-[3-(dibenzothiophen-4-yl)phenyl]-[1]benzofl[3,2-d]pyrimidine (abbreviation: 8mpTP-4mDBtPBfpm), 11-[(3'-dibenzothiophen-4-yl)biphenyl-3-yl Organic compounds having a diazine skeleton such as [Lu]phenantro[9',10':4,5]fl[2,3-b]pyrazine (abbreviation: 11mDBtBPPnfpr), 2-(biphenyl-4-yl)-4-phenyl-6-(9,9'-spirobi[9H-fluoren]-2-yl)-1,3,5-triazine (abbreviation: BP-SFTZn), 2-{3-[3-(benzo[b]naphtho[1,2-d]furan-8-yl)phenyl]phenyl}-4,6-diphenyl-1,3,5-triazine (abbreviation: mBnfBPTZn), 2-{3-[3-(benzo[b]naphtho[1,2-d]furan-6-yl)phenyl]phenyl}-4,6-diphenyl-1,3,5-triazine (abbreviation: mBnfBPTZn-02), 2-{4-[3-(N-phenyl-9H-carbazole-3-yl)-9H-carbazole-9-yl]phenyl}-4,6-diphenyl-1,3,5-triazine (abbreviation: PCCzPTZn), 9-[3-(4,6-diphenyl-1,3,5-triazine-2-yl)phenyl]-9'-phenyl-2,3'-bi-9H-carbazole (abbreviation: mPCCzPTZn-02), 2-[3'-(9,9-dimethyl-9 H-Fluoren-2-yl)biphenyl-3-yl]-4,6-diphenyl-1,3,5-triazine (abbreviation: mFBPTZn), 5-[3-(4,6-diphenyl-1,3,5-triazine-2-yl)phenyl]-7,7-dimethyl-5H,7H-indeno[2,1-b]carbazole (abbreviation: mINc(II)PTZn), 2-{3-[3-(dibenzothiophen-4-yl)phenyl]phenyl}-4,6-diphenyl-1,3,5-triazine (abbreviation: mDBtBPTZn), 2,4,6-tris[3'-(pyridine-3-yl)biphenyl- 3-yl]-1,3,5-triazine (abbreviation: TmPPPyTz), 2-[3-(2,6-dimethyl-3-pyridinyl)-5-(9-phenantrenyl)phenyl]-4,6-diphenyl-1,3,5-triazine (abbreviation: mPn-mDMePyPTzn), 11-[4-(biphenyl-4-yl)-6-phenyl-1,3,5-triazine-2-yl]-11,12-dihydro-12-phenylindoro[2,3-a]carbazole (abbreviation: BP-Icz(II)Tzn), 2-[3'-(triphenylene-2-yl)biphenyl-3-yl]-4,6 -Diphenyl-1,3,5-triazine (abbreviation: mTpBPTZn), 3-[9-(4,6-diphenyl-1,3,5-triazine-2-yl)-2-dibenzofuranyl]-9-phenyl-9H-carbazole (abbreviation: PCDBfTZn), 2-(biphenyl-3-yl)-4-phenyl-6-{8-[(1,1':4',1''-terphenyl)-4-yl]-1-dibenzofuranyl}-1,3,5-triazine (abbreviation: mBP-TPDBfTZn), 2-[4-(2-naphthalenyl)phenyl]-4-phenyl-6-spiro[9H-fluorene-9,9'-[9H]xanthene]-4-yl-1,3,5-triazine (abbreviation: βNP-SFx(4)TZn), 9,9'-{6-[3-(triphenylsilyl)phenyl]-1,3,5-triazine-2,4-diyl}bis(9H-carbazole) (abbreviation: SiTrzCz2), 2-phenyl-4,6-bis[3-(triphenylsilyl)phenyl]-1,3,5-triazine (abbreviation: mSiTrz), 2,4,6-tris(2-pyridyl)-1,3,5-triazine (abbreviation: 2Py3TZn), 11-[ 4-(biphenyl-4-yl)-6-phenyl-1,3,5-triazine-2-yl]-11,12-dihydro-12-(biphenyl-3-yl)indoro[2,3-a]carbazole (abbreviation: BP-mBPIcz(II)TZn), 3-{3-[9-(4,6-diphenyl-1,3,5-triazine-2-yl)-2-dibenzofuranyl]phenyl}-9-phenyl-9H-carbazole (abbreviation: mPCPDBfTZn), 9,9'-[6-(biphenyl-4-yl)-2-phenyl-1,3,5-to [Liazin-4,3''-diyl]bis(9H-carbazole) (abbreviation: Cz-pmCzBPTZn), 3-phenyl-9-[4-phenyl-6-(9-phenyl-3-dibenzofuranyl)-1,3,5-triazin-2-yl]-9H-carbazole (abbreviation: PDBf-PCzTZn), 9-[4-(4,6-diphenyl-1,3,5-triazin-2-yl)-2-dibenzothienyl]-2-phenyl-9H-carbazole (abbreviation: PCzDBtTZn), 2,4-diphenyl-6-[3'-(spiro [7H-benzo[c]fluorene-7,9'-[9H]xanthene]-2'-yl)biphenyl-3-yl]-1,3,5-triazine (abbreviation: mSbfxBPTZn), 3'-[4-phenyl-6-(spiro[9H-fluorene-9,9'-[9H]xanthene]-2'-yl)-1,3,5-triazine-2-yl]biphenyl-4-carbonitrile (abbreviation: mpCNBP-SFxTZn), 2,2'-[1,2-naphthalenediyldi(4,1-phenylene)]bis(4,6-diphenyl-1,3,Examples include organic compounds containing a heteroaromatic ring having a triazine skeleton, such as 5-triazine (abbreviated as TznP2N). Furthermore, organic compounds containing a heteroaromatic ring having a diazine skeleton, or a heteroaromatic ring having a pyridine skeleton, or a heteroaromatic ring having a triazine skeleton are preferred due to their good reliability. In particular, organic compounds containing a heteroaromatic ring having a diazine (pyrimidine or pyrazine) skeleton, or a heteroaromatic ring having a triazine skeleton, exhibit high electron transport properties and contribute to reducing the driving voltage.

[0275] The TADF materials listed above can be used as host materials. When a TADF material is used as a host material, the triplet excitation energy generated by the TADF material is converted into singlet excitation energy through reverse intersystem crossing, and this energy is then transferred to the light-emitting material, thereby increasing the luminescence efficiency of the light-emitting device. In this case, the TADF material functions as an energy donor, and the light-emitting material functions as an energy acceptor.

[0276] This is very effective when the above-mentioned luminescent material is a fluorescent luminescent material. Also, in order to obtain high luminescence efficiency in this case, the S of the TADF material １ The energy level is S of the fluorescent material. １ It is preferable that the level be higher than the level. Also, the T of the TADF material １ The energy level is S of the fluorescent material. １ It is preferable that the level be higher than the level of the TADF material. １ The energy level is the T of the fluorescent material. １ A level higher than the current level is preferable.

[0277] Furthermore, it is preferable to use a TADF material that exhibits emission that overlaps with the wavelength of the lowest-energy absorption band of the fluorescent material. This is preferable because it allows for a smooth transfer of excitation energy from the TADF material to the fluorescent material, resulting in efficient emission.

[0278] Furthermore, for singlet excitation energy to be efficiently generated from triplet excitation energy by reverse intersystem crossing, it is preferable that carrier recombination occurs in the TADF material. It is also preferable that the triplet excitation energy generated in the TADF material does not transfer to the triplet excitation energy of the fluorescent material. To achieve this, it is preferable that the fluorescent material has protecting groups around the luminescent phosphoform (the skeleton that causes luminescence). Preferred protecting groups are substituents without π bonds, saturated hydrocarbons, specifically alkyl groups having 3 to 10 carbon atoms, substituted or unsubstituted cycloalkyl groups having 3 to 10 carbon atoms, and trialkylsilyl groups having 3 to 10 carbon atoms. It is even more preferable to have multiple protecting groups. Substituents without π bonds have poor carrier transport function, and therefore can increase the distance between the TADF material and the luminescent phosphoform of the fluorescent material with little effect on carrier transport or carrier recombination. Here, the luminescent phosphoform refers to the atomic group (skeleton) that causes luminescence in the fluorescent material. The luminescent phosphophore preferably has a skeleton containing π bonds, preferably contains an aromatic ring, and preferably has a condensed aromatic ring or a condensed heteroaromatic ring. Examples of such luminescent phosphophores include phenanthrene skeletons, stilbene skeletons, acridone skeletons, phenoxazine skeletons, phenothiazine skeletons, naphthalene skeletons, anthracene skeletons, fluorene skeletons, chrysene skeletons, triphenylene skeletons, tetracene skeletons, pyrene skeletons, perylene skeletons, coumarin skeletons, quinacridone skeletons, and naphthobisbenzofuran skeletons. Fluorescent materials having naphthalene, anthracene, fluorene, chrysene, triphenylene, tetracene, pyrene, perylene, coumarin, quinacridone, and naphthobisbenzofuran skeletons are particularly preferred due to their high fluorescence quantum yield.

[0279] When using a fluorescent material as a light-emitting material, a material having an acene skeleton, particularly an anthracene skeleton, is preferred as the host material. Using a material having an anthracene skeleton as the host material for a fluorescent material makes it possible to realize a light-emitting layer with good luminescence efficiency and durability. Among the materials having an anthracene skeleton to be used as the host material, a material having a diphenylanthracene skeleton, particularly a 9,10-diphenylanthracene skeleton, is preferred because it is chemically stable. Furthermore, while a carbazole skeleton is preferred as the host material because it improves hole injection and transport, a benzocarbazole skeleton, in which a benzene ring is further condensed into the carbazole, is even more preferred because the HOMO level is about 0.1 eV higher than when only a carbazole skeleton is present, making it easier for holes to enter. In particular, a dibenzocarbazole skeleton is preferred as the host material is about 0.1 eV higher than when only a carbazole skeleton is present, making it easier for holes to enter, as well as providing excellent hole transport and high heat resistance. Therefore, a more preferred host material is a substance having both a 9,10-diphenylanthracene skeleton and a carbazole skeleton (or a benzocarbazole skeleton or dibenzocarbazole skeleton). Furthermore, from the viewpoint of hole injection and transport, a benzofluorene skeleton or a dibenzofluorene skeleton may be used instead of the carbazole skeleton. Additionally, it is preferable to include a dibenzofuran skeleton because reliability can be ensured without lowering the T1 level.

[0280] Examples of such substances include 9-phenyl-3-[4-(10-phenyl-9-anthryl)phenyl]-9H-carbazole (abbreviated as PCzPA), 3-[4-(1-naphthyl)phenyl]-9-phenyl-9H-carbazole (abbreviated as PCPN), 9-[4-(10-phenyl-9-antracenyl)phenyl]-9H-carbazole (abbreviated as CzPA), 7-[4-(10-phenyl-9-anthryl)phenyl]-7H-dibenzo[c,g]carbazole (abbreviated as cgDBCzPA), 6-[3-(9,10-diphenyl-2-anthryl)phenyl]benzo[b]naphtho[1,2-d]furan (abbreviated as 2mBnfPPA), and 9-phenyl-10-[4-(9-phenyl-9H-fluoren-9-yl)biphenyl-4'- [Iyl]anthracene (abbreviation: FLPPA), 9-(1-naphthyl)-10-[4-(2-naphthyl)phenyl]anthracene (abbreviation: αN-βNPAnth), 9-(1-naphthyl)-10-(2-naphthyl)anthracene (abbreviation: α,βADN), 2-(10-phenylanthracene-9-yl)dibenzofuran, 2-(10-phenyl-9-anthracenyl)ben Examples include zo[b]naphtho[2,3-d]furan (abbreviated as Bnf(II)PhA), 9-(2-naphthyl)-10-[3-(2-naphthyl)phenyl]anthracene (abbreviated as βN-mβNPAnth), and 1-{4-[10-(biphenyl-4-yl)-9-anthracenyl]phenyl}-2-ethyl-1H-benzimidazole (abbreviated as EtBImPBPhA). In particular, CzPA, cgDBCzPA, 2mBnfPPA, and PCzPA are preferred choices because they exhibit very good properties.

[0281] The host material may be a mixture of multiple substances, and when using a mixed host material, it is preferable to mix an electron-transporting material with a hole-transporting material. By mixing an electron-transporting material with a hole-transporting material, the transport properties of the light-emitting layer 113 can be easily adjusted, and the recombination region can also be easily controlled. The weight ratio of the hole-transporting material to the electron-transporting material is preferably in the range of hole-transporting material:electron-transporting material = 1:19 to 19:1.

[0282] Furthermore, phosphorescent materials can be used as part of the above-mentioned mixed materials. When a fluorescent material is used as the light-emitting material, the phosphorescent material can be used as an energy donor to supply excitation energy to the fluorescent material.

[0283] Furthermore, these mixed materials may form an excited complex. It is preferable to select a combination that forms an excited complex that exhibits emission overlapping with the wavelength of the lowest-energy absorption band of the luminescent material, as this facilitates smooth energy transfer and efficiently obtains light emission. This configuration is also preferable because it reduces the driving voltage.

[0284] Furthermore, at least one of the materials forming the excitation complex may be a phosphorescent material. This allows for the efficient conversion of the triplet excitation energy to the singlet excitation energy through reverse intersystem crossing.

[0285] For efficient excitation complex formation, it is preferable that the HOMO level of the hole-transporting material is above the HOMO level of the electron-transporting material. Furthermore, it is preferable that the LUMO level of the hole-transporting material is above the LUMO level of the electron-transporting material. The LUMO and HOMO levels of the materials can be derived from the electrochemical properties (reduction potential and oxidation potential) of the materials measured by cyclic voltammetry (CV).

[0286] The formation of excited complexes can be confirmed, for example, by comparing the emission spectra of a hole-transporting material, an electron-transporting material, and a mixed film made by mixing these materials, and observing that the emission spectrum of the mixed film shifts to a longer wavelength than the emission spectra of each individual material (or has a new peak on the longer wavelength side). Alternatively, it can be confirmed by comparing the transient photoluminescence (PL) of a hole-transporting material, the transient PL of an electron-transporting material, and the transient PL of a mixed film made by mixing these materials, and observing differences in the transient response, such as the transient PL lifetime of the mixed film having a longer lifetime component or a larger proportion of the delayed component than the transient PL lifetime of each individual material. Furthermore, the transient PL mentioned above may be read as transient electroluminescence (EL). That is, the formation of excited complexes can also be confirmed by comparing the transient EL of a hole-transporting material, the transient EL of an electron-transporting material, and the transient EL of a mixed film made by mixing these materials, and observing the differences in the transient response.

[0287] 《Electrodes of Light-Emitting Devices》 For electrodes of light-emitting devices, it is preferable to use a conductive film that transmits visible light for the electrode that extracts light. It is also preferable to use a conductive film that reflects visible light for the electrode that does not extract light.

[0288] Furthermore, a conductive film that transmits visible light may also be used on the electrode that does not extract light. In this case, it is preferable to place the electrode between the reflective layer and the EL layer. In other words, the light emitted from the EL layer may be reflected by the reflective layer and extracted from the display device.

[0289] It is preferable that the light-emitting device has a microcavity structure. Therefore, it is preferable that one of the pair of electrodes in the light-emitting device is a semitransmissive / semi-reflective electrode that transmits and reflects visible light, and the other is a reflective electrode that reflects visible light. By having a microcavity structure in the light-emitting device, the light emitted from the light-emitting layer can be resonated between the two electrodes, thereby strengthening the light emitted from the light-emitting device.

[0290] In Figure 3A, electrodes 551A, 551B, and 551C can function as lower electrodes for light-emitting devices 550A, 550B, and 550C, respectively. Electrode 552 can function as an upper electrode for light-emitting devices 550A, 550B, and 550C.

[0291] It is preferable that the lower electrodes of adjacent light-emitting devices be insulated from each other by an insulating layer. In Figure 3A, light-emitting device 550B is positioned adjacent to light-emitting device 550A, electrode 551B is adjacent to electrode 551A, and electrode 551B is positioned with a gap 551AB between it and electrode 551A. In other words, the gap 551AB is sandwiched between electrode 551A and electrode 551B. Figure 3A shows an example in which an insulating layer 528 is placed in the gap 551AB. The insulating layer 528 can provide an insulated state between electrode 551A and electrode 551B.

[0292] Electrode 552 includes a region that overlaps with electrode 551A, a region that overlaps with electrode 551B, a region that overlaps with electrode 551C, and a region that overlaps with the gap 551AB.

[0293] Furthermore, layers REFA, REFB, and REFC are located beneath electrodes 551A, 551B, and 551C, respectively. Layers REFA, REFB, and REFC have, for example, the function of reflecting light, or for example, the function of semi-transmitting and semi-reflecting light.

[0294] Conductive materials can be used for electrodes 551 and 552. Specifically, materials containing metals, alloys, or conductive compounds can be used in single layers or in multilayers. Examples of conductive compounds include oxides of metal materials and nitrides of metal materials.

[0295] Furthermore, when electrode 552 is used as the cathode and electrode 551 as the anode, it is preferable that the work function of the material used for electrode 552 is smaller than that of the material used for electrode 551X. Specifically, a material with a work function of 3.8 eV or less is preferred.

[0296] Elements belonging to Group 1 of the periodic table, elements belonging to Group 2 of the periodic table, rare earth metals, and alloys containing these, such as lithium (Li), cesium (Cs), magnesium (Mg), calcium (Ca), strontium (Sr), europium (Eu), ytterbium (Yb), and alloys containing these, such as an alloy of magnesium and silver or an alloy of aluminum and lithium, can be used for the electrode 552.

[0297] When light is extracted from the electrode 552 side, it is preferable to use a semi-transparent / semi-reflective electrode for electrode 552.

[0298] As semi-transmissive and semi-reflective electrodes, for example, elements belonging to Group 1 of the periodic table, elements belonging to Group 2 of the periodic table, rare earth metals, and alloys containing these can be used for electrode 552. Specifically, it is more preferable to use a film formed by co-deposition, such as Ag:Mg (an alloy of silver and magnesium) or Mg:In ​​(an alloy of magnesium and indium), or a film formed by co-deposition of an element belonging to Group 1 or 2 of the periodic table and aluminum.

[0299] Furthermore, semi-transmissive and semi-reflective electrodes can have a laminated structure consisting of a reflective electrode and an electrode that transmits visible light (also called a transparent electrode).

[0300] Furthermore, for example, a film that efficiently reflects light can be used for the electrode 551. For example, a film containing silver (Ag) or aluminum (Al) can be used in a single layer or in a multilayer structure. Examples of materials used for the electrode 551 include aluminum alloys such as aluminum-nickel-lanthanum alloys (Al-Ni-La), and silver alloys such as silver-magnesium alloys and silver-palladium-copper alloys (Ag-Pd-Cu, also written as APC). Other examples of such materials include elements belonging to Group 1 or Group 2 of the periodic table not exemplified above (e.g., lithium, cesium, calcium, strontium), rare earth metals such as europium and ytterbium, and alloys containing these in appropriate combinations, graphene, and the like.

[0301] Furthermore, for example, a metal film that transmits some of the light and reflects other parts of the light can be used for the electrode 552.

[0302] Furthermore, for example, a film that is transparent to visible light can be used for the electrode 552. Specifically, a thin metal film, alloy film, or conductive oxide film that is thin enough to transmit light can be used for the electrode 552 in a single layer or in multiple layers.

[0303] For example, metal oxides with high conductivity and light transmission can be used. For example, oxides having two or more metals selected from zinc, indium, tin, aluminum, gallium, and hafnium can be used. For example, materials having the above-mentioned elements M1, M2, and oxygen can be used. Elements M1 and M2 are one and one selected from zinc, indium, tin, aluminum, gallium, and hafnium. It is preferable that element M1 is one selected from zinc, indium, and tin.

[0304] For example, metal oxides containing zinc can be used. Specifically, zinc oxide, zinc-aluminum oxide, etc., can be used. For example, conductive oxides containing indium can be used. Specifically, indium oxide, indium tin oxide (abbreviated as ITO), indium tin oxide containing silicon or silicon oxide (abbreviated as ITSO), indium zinc oxide, indium oxide containing tungsten oxide and zinc oxide (abbreviated as IWZO), etc., can be used.

[0305] In addition, for example, gold (Au), platinum (Pt), nickel (Ni), tungsten (W), chromium (Cr), molybdenum (Mo), iron (Fe), cobalt (Co), copper (Cu), palladium (Pd), or nitrides of metallic materials (e.g., titanium nitride) can be used. Alternatively, graphene can be used.

[0306] Multiple of the materials listed above can also be used as electrodes 552 by stacking them.

[0307] Furthermore, the electrode 552 can be formed using the same material and manufacturing method as layer 105X. As mentioned earlier, layer 105X has high conductivity and excellent permeability. Therefore, a layer formed using the same material and manufacturing method can be suitably used as electrode 552. Specifically, a layer formed by atomic layer deposition of zinc-aluminum oxide can be used as electrode 552. This layer has high conductivity and excellent permeability. Furthermore, it has low reactivity to oxygen, moisture, etc., and is stable, so for example, it has high barrier properties. In addition, layers formed by atomic layer deposition often have high coverage and excellent adhesion, which is preferable. Therefore, by using it as electrode 552, the reliability of the light-emitting device can be improved. For example, a long-life light-emitting device can be realized.

[0308] Furthermore, by using the same material and manufacturing method as layer 105X for electrode 552, for example, electrode 552 and layer 105X can be manufactured using the same apparatus. This improves productivity.

[0309] The materials that can be used as electrode 552 as described above can also be used as electrode 551 as appropriate.

[0310] The electrode 551 can be made of a metal, a conductive oxide, or the like. Alternatively, the electrode 551 can be made by stacking multiple layers of these materials.

[0311] When electrode 551 is used as the anode, it is preferable to use a material with a large work function.

[0312] A conductive oxide containing indium can be used as electrode 551. Specifically, indium oxide, indium oxide-tin oxide, silicon or silicon oxide-containing indium oxide-tin oxide, indium oxide-zinc oxide, tungsten oxide, and zinc oxide-containing indium oxide can be used.

[0313] Furthermore, reflective electrodes or semi-transparent / semi-reflective electrodes can be used as layer REFA, layer REFB, and layer REFC.

[0314] When light is extracted from the electrode 552 side, for example, reflective electrodes are used as layers REFA, REFB, and REFC. In this case, transparent electrodes are used as electrodes 551A, 551B, and 551C, which can be used as optical adjustment layers for the microcavity structure. The optical path length can be adjusted by changing the thickness of the conductive layer.

[0315] For example, metals or alloys can be used in layered REFA, layered REFB, and layered REFC. For example, films containing silver (Ag) or aluminum (Al) can be used in single layers or in layers in layered REFA, layered REFB, and layered REFC. Metal films such as alloys containing silver and copper, alloys containing silver and palladium, or aluminum can also be used in layered REFA, layered REFB, and layered REFC. Furthermore, these materials can be used in layers with one or more selected from metals, alloys, nitrides of metal materials, and oxides of metal materials. For example, a configuration can be used in which layers of titanium nitride are provided above and below a layer mainly composed of aluminum (Al).

[0316] <Intermediate layer 106> Figures 3A to 3C show an example in which the light-emitting device 550X has one unit 103, but the light-emitting device 550X can also be configured to have multiple units 103 and an intermediate layer 106 located between two stacked units 103. In Figures 4A and 4B, the light-emitting device 550X has unit 103X and unit 103X2, unit 103X2 has layers 112X2, layer 111X2, and layer 113X2, and the intermediate layer 106 is arranged between unit 103X and unit 103X2.

[0317] Layers 112X2, 111X2, and 113X2 can refer to layers 112X, 111X, and 113X, respectively.

[0318] A layer 104X is placed on electrode 551X, a unit 103X is placed on layer 104X, an intermediate layer 106 is placed on unit 103X, a unit 103X2 is placed on intermediate layer 106, a layer 105X is placed on unit 103X2, and an electrode 552 is placed on layer 105X. In Figure 4B, a layer 105_2 is placed between layer 105X and electrode 552.

[0319] The intermediate layer 106X can be, for example, a laminated structure of layer 106X2, layer 106X3 above layer 106X2, and layer 106X1 above layer 106X3. Alternatively, the intermediate layer 106X may have at least one of these three layers. Specifically, the intermediate layer 106X has at least a layer in which electron acceptors are added to a hole transport material (also called a charge generation region). In addition to the charge generation region, a configuration in which electron donors are added to an electron transport material (also called an electron injection buffer layer) may be laminated. Furthermore, an electron relay layer may be provided between the charge generation region and the electron injection buffer layer.

[0320] For example, layer 106X1 can be made of a material with hole injection properties as a charge generation region. As a material with hole injection properties, for example, the material that layer 104X described above can have can be used.

[0321] Specifically, 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 described above. Furthermore, oxides of metals belonging to groups 4 through 8 of the periodic table can be used. Specifically, examples include vanadium oxide, niobium oxide, tantalum oxide, chromium oxide, molybdenum oxide, tungsten oxide, manganese oxide, and rhenium oxide. The acceptor material described above may also be used. Alternatively, the materials constituting the charge generation region may be used as a mixed film, or as single films containing each material stacked together.

[0322] Furthermore, for example, layer 106X2 can be an electron injection buffer layer made of an electron injection material.

[0323] Furthermore, by providing an electron injection buffer layer, the injection barrier between the charge generation region and the electron transport layer can be mitigated, allowing electrons generated in the charge generation region to be easily injected into the electron transport layer.

[0324] The electron injection buffer layer preferably contains an organic compound with a phenanthroline skeleton. The organic compound containing the phenanthroline skeleton has an electron mobility of 1 × 10⁻¹⁶ at an electric field strength [V / cm] square root of 600. −７ cm ２ / Vs or more, preferably 1 x 10 −６ cm ２ It is preferable that the electron mobility is greater than / Vs and that the material has electron transport properties. However, other materials can be used as long as they have higher electron transport properties than holes.

[0325] The organic compound containing the phenanthroline skeleton is preferably a compound containing both the phenanthroline skeleton and an aromatic ring. The aromatic ring can be a monocyclic or polycyclic aromatic ring.

[0326] Furthermore, the electron injection buffer layer preferably contains a metal or a metal compound in addition to the organic compound containing the phenanthroline skeleton. The metal in the metal compound preferably includes alkali metals, alkaline earth metals, rare earth metals, or metals belonging to Group 11 or Group 13 of the periodic table, and their oxides and carbonates. For example, it can be configured to include an alkali metal compound or an alkaline earth metal compound. Specifically, the electron injection buffer layer preferably has an inorganic compound containing an alkali metal and oxygen, or an inorganic compound containing an alkaline earth metal and oxygen, and an inorganic compound containing lithium and oxygen (lithium oxide (Li ２ It is more preferable to have O, etc. Also, the electron injection buffer layer may contain cesium (Cs), magnesium (Mg), calcium (Ca), ytterbium (Yb), indium (In), lithium oxide (Li ２0), cesium carbonate, etc., can be suitably used. Organic compounds such as tetrathianaphthalene may also be used. In addition, materials applicable to the electron injection buffer layer can be suitably used.

[0327] Furthermore, the electron injection buffer layer may have a laminated structure consisting of a layer containing an organic compound and a layer containing a metal or metal compound located on the cathode side of the layer containing the organic compound. Alternatively, it may be a mixed layer of an organic compound and a metal or metal compound. When the charge generation region is a mixed layer, it is preferable because it requires fewer deposition chambers, thus reducing manufacturing costs, and also contributes to improving the stability of the light-emitting device.

[0328] Furthermore, in addition to the organic compounds described above, organic compounds containing a phenanthroline skeleton that have electron-donating substituents can also be used. The phenanthroline skeleton is a skeleton that readily interacts with metals and other materials, and by further possessing electron-donating groups in such organic compounds containing a phenanthroline skeleton, the electron density of the phenanthroline skeleton increases, making it even easier to interact with metals or metal compounds. In particular, when metals from Group 3, Group 11, Group 12, or Group 13 are used as the metal in the metal or metal compound, it is possible to suppress the increase in driving voltage and provide a tandem type light-emitting device with good characteristics.

[0329] Specific examples of electron-donating groups include alkyl groups, alkoxy groups, aryloxy groups, alkylamino groups, arylamino groups, and heterocyclic amino groups. However, the electron-donating groups that are preferable to introduce into the phenanthroline ring are not limited to these. Any group that can increase the electron density of the phenanthroline ring when introduced into it can be used as an electron-donating group. Furthermore, the electron-donating group may be introduced into the phenanthroline ring via an arylene group such as a phenylene group, and the p-phenylene group is preferred as the arylene group.

[0330] The electron injection buffer layer may further contain an organic compound different from the organic compound containing a phenanthroline skeleton. The organic compound is preferably an organic compound having electron transport properties. In particular, the organic compound preferably has two or more heteroaromatic rings that are bonded or fused to each other, and the two or more heteroaromatic rings have a total of 3 or more heteroatoms. When the first layer contains such an organic compound, improvement in heat resistance, improvement in electron transport properties, and the like can be achieved.

[0331] Further, for example, a material having electron transport properties can be used for the layer 106X3 serving as an electron relay layer. The electron relay layer has a function of preventing interaction between the charge generation region and the electron injection buffer layer (or electron transport layer) to smoothly transfer electrons. Further, when the layer 106X3 is used, the layer in contact with the anode side of the layer 106X3 can be separated from the layer in contact with the cathode side of the layer 106X3. The interaction between the layer in contact with the anode side of the layer 106X3 and the layer in contact with the cathode side of the layer 106X3 can be reduced. Electrons can be smoothly supplied to the layer in contact with the anode side of the layer 106X3.

[0332] A substance having a LUMO level between the LUMO level of the substance contained in the layer 106X1 and the LUMO level of the substance contained in the layer 106X2 can be suitably used for the layer 106X3.

[0333] For example, a material having a LUMO level in a range of -5.0 eV or higher, preferably -5.0 eV or higher and -3.0 eV or lower, can be used for the layer 106X3.

[0334] Specifically, a phthalocyanine-based material can be used for the layer 106X3. For example, a phthalocyanine-based material such as phthalocyanine (abbreviation: H2Pc), copper(II) phthalocyanine (abbreviation: CuPc), or zinc phthalocyanine (abbreviation: ZnPc), or a metal complex having a metal-oxygen bond and an aromatic ligand can be used for the layer 106X3.

[0335] Note that the light-emitting device 550X described with reference to FIGS. 4A and 4B has a function of emitting light ELX and light ELX2.

[0336] <Example of Display Device Configuration 2-1> Figure 5A shows a display device according to one embodiment of the present invention. Figure 5A is a cross-sectional view illustrating the configuration of a display device 700 according to one embodiment of the present invention, and differs from Figure 3A mainly in that it has an insulating layer 529 and does not have an insulating layer 528. Figure 5B is an enlarged view of a part of Figure 5A.

[0337] Hereafter, the symbols A, B, and C may be omitted in descriptions common to layers 104A, 104B, and 104C. The same applies to units 103A, 103B, and 103C. The same also applies to layers 105A, 105B, and 105C. The same also applies to layers REFA, REFB, and REFC. The same also applies to electrodes 551A, 551B, and 551C.

[0338] In Figure 5A, layer 104 covers the top surface of electrode 551, the side surface of electrode 551, and the side surface of layer REFA. The edges of layer 104, unit 103, and layer 105 are located outside the edges of electrode 551.

[0339] In Figure 5A, the insulating layer 529 covers the sides of layer 104, unit 103, and layer 105, respectively. The insulating layer 529 also covers a portion of the upper surface of layer 105 and has an opening 561 on top of layer 105. When viewed in plan, for example, the insulating layer 529 has a portion located between adjacent light-emitting devices. When viewed in plan, the insulating layer 529 has a portion located between the respective electrodes 551 (e.g., electrode 551B and electrode 551C) of adjacent light-emitting devices. Furthermore, on the upper surface of the insulating layer 521, for example, the insulating layer 529 is in contact with the portion located between adjacent light-emitting devices when viewed in plan. Furthermore, on the upper surface of the insulating layer 521, the insulating layer 529 is in contact with the portion located between the respective electrodes 551 (e.g., electrode 551B and electrode 551C) of adjacent light-emitting devices when viewed in plan.

[0340] The electrode 552 is provided on the insulating layer 529. Preferably, the electrode 552 has a portion located within the opening of the insulating layer 529 and in contact with the upper surface of layer 105A, a portion located within the opening of the insulating layer 529 and in contact with the upper surface of layer 105B, and a portion located within the opening of the insulating layer 529 and in contact with the upper surface of layer 105C.

[0341] The presence of the insulating layer 529 in the display device 700 can suppress leakage current between the electrode 552 and the side surface of layer 104. It can also suppress leakage current between the electrode 552 and the side surface of unit 103. In particular, if layer 104 contains a material with hole injection properties, the conductivity of layer 104 is high, and a conduction path is formed between electrode 551 and electrode 552 that does not pass through unit 103 and layer 105, raising concerns that malfunctions may occur in the operation of the light-emitting device. By providing the insulating layer 529, the characteristics and reliability of the light-emitting device can be improved.

[0342] Furthermore, the configuration shown in Figure 6A differs from that in Figure 5A mainly in that it has layer 105_2. Note that in Figure 6A and subsequent figures, for the sake of simplification, components below the insulating layer 521 may not be shown or may be omitted from the figures. Figure 6B is an enlarged view of a part of Figure 6A.

[0343] Figure 6A also shows an example of an electrode 552, in which the electrode 552 has a laminated structure of conductive layer 552_1 and conductive layer 552_2. Note that the electrode 552 can have a laminated structure other than that shown in Figure 6A.

[0344] Layer 105_2 is a layer provided in common to light-emitting devices 550A, 550B, and 550C. In Figure 6A, layer 105_2 is provided on top of the insulating layer 529. Preferably, layer 105_2 has a portion located within the opening of the insulating layer 529 and in contact with the upper surface of layer 105A, a portion located within the opening of the insulating layer 529 and in contact with the upper surface of layer 105B, and a portion located within the opening of the insulating layer 529 and in contact with the upper surface of layer 105C.

[0345] The conductive layer 552_1 is provided on top of layer 105_2. The conductive layer 552_2 is provided on top of the conductive layer 552_1.

[0346] The conductive layer 552_1 is, for example, a layer provided in contact with the EL layer. Therefore, it is preferable that the conductive layer 552_1 be provided using a method that causes minimal damage to the EL layer. The conductive layer 552_1 can be formed, for example, by vacuum deposition. Here, for example, an Ag:Mg layer is used as the conductive layer 552_1.

[0347] The conductive layer 552_2 can be formed, for example, using a method that provides higher coverage than the conductive layer 552_2. Furthermore, the conductive layer 552_2 can be made thicker than the conductive layer 552_1, for example. Here, for example, a translucent metal oxide can be used as the conductive layer 552_2.

[0348] As shown in Figure 6C, the thicknesses of the EL layers of light-emitting devices 550A, 550B, and 550C may be different. Figure 6C shows an example in which the thicknesses of units 103A, 103B, and 103C are different.

[0349] <Example of Display Device Configuration 2-2> Figure 7A shows a display device according to one embodiment of the present invention. Figure 7A is a cross-sectional view illustrating the configuration of a display device 700 according to one embodiment of the present invention, and the configuration of the EL layer differs from that of Figure 5A. Figure 5A shows an example in which Figure 3C is applied as the configuration of the light-emitting devices 550A, 550B and 550C, and Figure 7A shows an example in which Figure 4B is applied as the configuration of the light-emitting devices 550A, 550B and 550C. Figure 7B shows an enlarged view of a part of Figure 7A.

[0350] In Figure 7A, the insulating layer 529 covers the side of unit 103B on the side of light-emitting device 550C, the side of the intermediate layer 106B on the side of light-emitting device 550C, the side of unit 103B2 on the side of light-emitting device 550C, the side of unit 103C2 on the side of light-emitting device 550B, the side of the intermediate layer 106C on the side of light-emitting device 550B, and the side of unit 103C2 on the side of light-emitting device 550C. The insulating layer 529 also covers the side of unit 103A on the side of light-emitting device 550B, the side of the intermediate layer 106A on the side of light-emitting device 550B, the side of unit 103A2 on the side of light-emitting device 550C, the side of unit 103B on the side of light-emitting device 550A, the side of the intermediate layer 106B on the side of light-emitting device 550C, and the side of unit 103B2 on the side of light-emitting device 550C.

[0351] <Modified Display Device 1> Figures 8A to 8D show modified displays.

[0352] Figure 8A shows a display device according to one embodiment of the present invention. Figure 8A is a cross-sectional view illustrating the configuration of a display device 700 according to one embodiment of the present invention, and differs from Figure 5A in the shape of the electrodes 551 and EL layer of the display device. Figure 8C is an enlarged view of a part of Figure 8A.

[0353] In Figure 8A, the edges of layer 104, unit 103, and layer 105 are located inward from the edges of electrode 551.

[0354] In Figure 8A, the insulating layer 529 covers a portion of the side surface of layer REF, the side surface of electrode 551, the side surface of layer 104, the side surface of unit 103, the side surface of layer 105, a portion of the top surface of electrode 551, and a portion of the top surface of layer 105.

[0355] Figure 8B shows a display device according to one embodiment of the present invention. Figure 8B is a cross-sectional view illustrating the configuration of a display device 700 according to one embodiment of the present invention, and differs from Figures 5A and 8A in the shape of the electrodes 551 and EL layer of the display device. In addition, it has an insulating layer 528 in addition to the insulating layer 529. Figure 8D is an enlarged view of a part of Figure 8B.

[0356] The insulating layer 528 covers a portion of the side surface of layer REF and the side surface of electrode 551. The insulating layer 528 also covers the end of electrode 551. Layer 104 is provided on the upper surface of electrode 551 in contact with the portion not covered by insulating layer 528. When viewed in plan, for example, insulating layer 528 has a portion located between adjacent light-emitting devices. When viewed in plan, insulating layer 528 has a portion located between each electrode 551 of adjacent light-emitting devices (for example, electrode 551B and electrode 551C). When viewed in plan, insulating layer 528 is located between each electrode 551 of adjacent light-emitting devices (for example, electrode 551B and electrode 551C). When viewed in plan, insulating layer 528 is located between each electrode 551 of adjacent light-emitting devices (for example, electrode 551B and electrode 551C). When viewed in plan, insulating layer 528 is in contact with the portion located between adjacent light-emitting devices when viewed in plan, on the upper surface of insulating layer 521.

[0357] In Figure 8B, the ends of layer 104, unit 103, and layer 105 are located inward from the ends of electrode 551.

[0358] In Figure 8B, the insulating layer 529 covers the top surface of the insulating layer 528, the side surface of layer 104, the side surface of unit 103, the side surface of layer 105, a portion of the top surface of electrode 551A, and a portion of the top surface of layer 105.

[0359] In the configurations shown in Figures 8A and 8B, for example, the distance between the electrodes 551 of adjacent light-emitting devices can be reduced. Furthermore, in the configuration shown in Figure 8B, insulating layers 528 and 529 can be provided between electrode 552 and electrode 551, thereby further reducing the leakage current between electrode 551 and electrode 552.

[0360] <Example of Display Device Configuration 3-1> A display device according to one aspect of the present invention may have a configuration having a conductive layer 553. The conductive layer 553 can function as auxiliary wiring for the electrode 552. The conductive layer 553 may also be called an auxiliary electrode.

[0361] The semiconductor device shown in Figure 9A differs from that in Figure 5A mainly in that it has a conductive layer 553 between the insulating layer 529 and the electrode 552. Figure 9B is an enlarged view of a part of Figure 9A.

[0362] The conductive layer 553 is provided over the insulating layer 529, and has an opening 562 overlapping with an opening 561 of the insulating layer 529. The conductive layer 553 also has a portion located between adjacent light-emitting devices when viewed in a plan view.

[0363] Materials that can be used for the electrode 551 and the electrode 552 can also be used for the conductive layer 553.

[0364] The electrode 552 is in contact with the top surface of the conductive layer 553. The conductive layer 553 is located between adjacent light-emitting devices. Further, the opening 562 of the conductive layer 553 can be provided so as to overlap with the light-emitting region of the light-emitting device. Therefore, when the light-emitting device emits light from the electrode 552 side, even if a light-blocking material is used as the conductive layer 553, the light emission of the light-emitting device is not inhibited. That is, the degree of freedom of materials that can be used for the conductive layer 553 is increased. For example, in the case where a metal layer is used as the conductive layer 553, the metal layer can be used without reducing the thickness to such an extent that light transmits therethrough. Accordingly, the electric conductivity of the conductive layer 553 can be increased. Since the conductive layer 553 can function as an auxiliary wiring for the electrode 552, a voltage drop in the plane of the electrode 552 can be suppressed.

[0365] Further, by using a light-shielding material as the conductive layer 553, the contrast of the display device can be increased.

[0366] Further, there are cases where unevenness of the formation surface of the conductive layer 553 is large between adjacent light-emitting devices. By forming the conductive layer 553 using a method with high coverage, disconnection of the conductive layer 553 can be suppressed. Further, by increasing the thickness of the conductive layer 553, for example, disconnection of the conductive layer 553 can be suppressed regardless of the film formation method of the conductive layer 553.

[0367] In the case where the conductive layer 553 is not provided, the electrode 552 is provided in a region with large unevenness on the formation surface, and in this case, when the thickness of the electrode 552 is reduced, disconnection or the like of the electrode 552 may occur. By providing the conductive layer 553, the thickness of the electrode 552 can be reduced.

[0368] It is preferable that the electrode 552 is in contact with the side surface of the opening 562 of the conductive layer 553. Furthermore, reducing the taper angle of the side surface of the opening 561 can improve the coverage of the electrode 552.

[0369] The taper angle of the side surface of the opening 562 of the conductive layer 553 refers, for example, to the angle between the surface of the conductive layer 553 that contacts the substrate and the side surface of the conductive layer 553. Alternatively, it can be the angle with respect to a reference surface such as the substrate surface. The taper angle is, for example, greater than 0° and 90° or less. By making the taper angle smaller than, for example, 80°, preferably smaller than 60°, and even more preferably smaller than 45°, the coverage of the electrode 552 on the side surface of the conductive layer 553 can be improved.

[0370] Furthermore, it is preferable to reduce the taper angle of the side surface of the opening 561 of the insulating layer 529. The taper angle of the side surface of the opening 561 of the insulating layer 529 refers, for example, to the angle between the surface of the insulating layer 529 that is in contact with the substrate and the side surface of the insulating layer 529. Alternatively, it can be the angle with respect to a reference surface such as the substrate surface.

[0371] Figure 9C shows an example where the taper angles of the side surface of the opening 562 in the conductive layer 553 and the side surface of the opening 561 in the insulating layer 529 are reduced compared to Figures 9A and 9B. A smaller taper angle improves the coverage of the electrode 552. Furthermore, improved coverage allows for, for example, a reduction in the thickness of the electrode 552.

[0372] Figure 10A shows an example configuration that includes layer 105_2 in addition to the configuration shown in Figure 9A. Layer 105_2 has a portion located between the conductive layer 553 and the electrode 552.

[0373] Furthermore, as shown in Figure 10B, the coverage of the electrode 552 can be improved by reducing the taper angle of the side surface of the opening 562 of the conductive layer 553 and the side surface of the opening 561 of the insulating layer 529.

[0374] <Example of Display Device Configuration 3-2> The semiconductor device shown in Figure 11A has a conductive layer 553 in addition to the configuration shown in Figure 8A. Figure 11B is an enlarged view of a part of Figure 11A. Figure 11C shows an example in which the taper angles of the side surface of the opening 562 of the conductive layer 553 and the side surface of the opening 561 of the insulating layer 529 are made smaller compared to Figure 11B.

[0375] Figure 12A shows an example configuration that includes layer 105_2 in addition to the configuration shown in Figure 11A. Furthermore, as shown in Figure 12B, the coverage of the electrode 552 can be improved by reducing the taper angle of the side surface of the opening 562 of the conductive layer 553 and the side surface of the opening 561 of the insulating layer 529.

[0376] <Modified Display Device 1> Figures 13A and 13B show modified displays.

[0377] The configuration shown in Figure 13A differs from the configurations shown in Figure 9B and other figures in that the ends of layer 104, unit 103, and layer 105 are located inward from the ends of electrode 551. In Figure 13A, the insulating layer 529 covers the sides of layer REFB and layer REFC, the sides of electrode 551B and electrode 551, the sides of layer 104B and layer 104C, the sides of unit 103B and unit 103C, the sides of layer 105B and layer 105C, a portion of the upper surface of electrode 551B, a portion of the upper surface of electrode 551C, a portion of the upper surface of layer 105B, and a portion of the upper surface of layer 105C.

[0378] The configuration shown in Figure 13B differs from that in Figure 11B, etc., mainly in that it has an insulating layer 528b instead of insulating layer 528. The insulating layer 528b covers the sides of layer REF and electrode 551. The insulating layer 528b can be formed, for example, by anisotropic etching. The insulating layer 529 covers the sides of layers 104B and 104C, the sides of units 103B and 103C, the sides of layers 105B and 105C, a portion of the upper surface of electrode 551B, a portion of the upper surface of electrode 551C, a portion of the upper surface of layer 105B, and a portion of the upper surface of layer 105C. The insulating layer 529 also faces the sides of layer REFB, layer REFC, electrode 551B, and electrode 551C, with insulating layer 528b in between.

[0379] In addition, in the configurations shown in Figures 8A to 13B above, the EL layer of the light-emitting device 550 can be appropriately adapted to the configuration shown in Figure 4A or Figure 4B. That is, in each configuration, for example, the laminated structure of layer 104, unit 103, and layer 105 can be replaced with a configuration of layer 104, unit 103, intermediate layer 106, unit 103X2, and layer 105.

[0380] <Method for Manufacturing the Display Device> The method for manufacturing the display device is described below.

[0381] Furthermore, thin films (insulating films, semiconductor films, conductive films, etc.) that constitute the display device can be formed using methods such as sputtering, chemical vapor deposition (CVD), vacuum deposition, pulsed laser deposition (PLD), and atomic layer deposition (ALD).

[0382] Furthermore, thin films (insulating films, semiconductor films, conductive films, etc.) that constitute the display device can be formed by methods such as spin coating, dip coating, spray coating, inkjet printing, dispensing, screen printing, offset printing, doctor knife coating, slit coating, roll coating, curtain coating, and knife coating.

[0383] Sputtering methods include RF sputtering, which uses a high-frequency power supply for sputtering; DC sputtering, which uses a DC power supply; and pulsed DC sputtering, which changes the voltage applied to the electrodes in pulses. For film deposition using insulating targets, RF sputtering is preferable. DC sputtering is mainly used when depositing films using conductive targets. In addition to forming conductive films, DC sputtering can also be used to form insulating films by reactive sputtering using pulsed DC sputtering. Specifically, pulsed DC sputtering can be used when depositing compounds such as oxides, nitrides, and carbides using reactive sputtering.

[0384] CVD methods can be classified into plasma-enhanced CVD (PECVD), which utilizes plasma; thermal CVD (TCD), which utilizes heat; and photo-CVD (Photo-CVD), which utilizes light. Furthermore, depending on the source gas used, they can be divided into metal CVD (MCCVD) and metal-organic CVD (MOCVD) methods.

[0385] Plasma CVD allows for the production of high-quality films at relatively low temperatures. Thermal CVD, on the other hand, does not use plasma, thus minimizing plasma damage to the workpiece. Furthermore, thermal CVD avoids plasma damage during film formation, resulting in films with fewer defects.

[0386] As ALD methods, thermal ALD, which carries out the reaction of the precursor and reactant using only thermal energy, and PEALD, which uses plasma-excited reactants, can be used.

[0387] Unlike sputtering, CVD and ALD are film deposition methods that are less affected by the shape of the workpiece and provide good step-level coverage. In particular, the ALD method is suitable for coating the surface of openings with high aspect ratios due to its excellent step-level coverage and excellent thickness uniformity. However, since the ALD method has a relatively slow deposition rate, it is sometimes preferable to use it in combination with other film deposition methods that have a faster deposition rate, such as the CVD method.

[0388] In CVD (Chemical Vapor Deposition), films of any composition can be deposited by changing the flow rate ratio of the raw material gases. For example, in CVD, by changing the flow rate ratio of the raw material gases while the film is being deposited, films with continuously changing compositions can be deposited. When depositing films while changing the flow rate ratio of the raw material gases, the time required for film deposition can be shortened compared to depositing films using multiple deposition chambers, because time spent on transport or pressure adjustment is eliminated. Therefore, it may be possible to increase the productivity of semiconductor devices.

[0389] In the ALD method, films of any composition can be deposited by simultaneously introducing multiple different types of precursors. Alternatively, when introducing multiple different types of precursors, films of any composition can be deposited by controlling the number of cycles for each precursor. Furthermore, similar to the CVD method, films with continuously changing compositions can be deposited.

[0390] Furthermore, the thin films constituting the display device can be processed using photolithography or other methods. Alternatively, the thin films may be processed by nanoimprint lithography, sandblasting, lift-off methods, etc. Island-like thin films may also be directly formed using a film deposition method with a shielding mask such as a metal mask. Induced self-assembly (DSA) methods may also be used.

[0391] There are two main methods of photolithography. One method involves forming a resist mask on the thin film to be processed, then processing the thin film by etching or other means, and removing the resist mask. The other method involves forming a photosensitive thin film, then exposing and developing it to process the thin film into the desired shape.

[0392] 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 thereof. Other light sources such as ultraviolet light, KrF laser light, or ArF laser light can also be used. Exposure may also be performed using immersion lithography. Furthermore, extreme ultraviolet (EUV) light or X-rays may be used as the light source for exposure. An electron beam can also be used instead of the light source for exposure. Using extreme ultraviolet light, X-rays, or an electron beam is preferable because it enables extremely fine processing. Note that a photomask is not required when exposure is performed by scanning a beam such as the above-mentioned light or an electron beam.

[0393] Thin films can be etched using methods such as dry etching, wet etching, and sandblasting. Dry etching allows for isotropic or anisotropic etching by controlling the conditions. Wet etching allows for isotropic etching.

[0394] [Method for Manufacturing the Display Device 1] The method for manufacturing the light-emitting devices 550A, 550B, and 550C of the display device 700 is described below.

[0395] First, layers REFA, REFB, and REFC are formed on the insulating layer 521. Specifically, for example, conductive films are laminated and processed into a predetermined shape using photolithography. As the conductive film, for example, a film having the function of reflecting light is used.

[0396] Next, electrode 551A is formed on layer REFA, electrode 551B is formed on layer REFB, and electrode 551C is formed on layer REFC (see Figure 14A). Specifically, for example, electrodes 551A, 551B, and 551C are formed by forming a light-transmitting conductive film and processing it into a predetermined shape using photolithography. Electrode 551B is adjacent to electrode 551A, and electrode 551B has a gap 551AB between it and electrode 551A.

[0397] Here, when a transparent conductive film is used as electrodes 551A, 551B, and 551C, these electrodes can be used as an optical adjustment layer. By adjusting the thickness of the optical adjustment layer, a microcavity structure can be realized by adjusting the thickness of the optical adjustment layer so that the optical path length becomes such that the light emitted from the light-emitting device is intensified. If the light-emitting devices 550A, 550B, and 550C each correspond to different colors, it is preferable that the thickness of electrodes 551A, 551B, and 551C also correspond to the wavelength of light of their respective colors.

[0398] Furthermore, the optical path length of the light emitted from the light-emitting device can also be adjusted by changing the thickness of the EL layer of the light-emitting device.

[0399] Next, a film 104Cf, which will later become layer 104C, and a laminated film 103Cf, which will later become unit 103C, are formed in order on electrode 551C, electrode 551B, and electrode 551A. Film 104Cf and laminated film 103Cf are formed, for example, using a vacuum deposition method (Figure 14B).

[0400] Next, a film 105Cf, which will later become layer 105C, is formed on top of the laminated film 103Cf (Figure 14B).

[0401] The film 105Cf is preferably formed using atomic layer deposition (ALD). Examples of ALD methods include thermal ALD, in which the reaction between the precursor and reactant is carried out using only thermal energy, and plasma-enhanced ALD, which uses a plasma-excited reactant. The film 105Cf can also be formed using CVD. Thermal CVD is particularly preferred because it causes less plasma damage to the film-forming surface during film formation.

[0402] It is preferable to use the thermal ALD method as the ALD method. By using the thermal ALD method to form the film 105Cf and forming the film at a low temperature, it is possible to suppress damage to the laminated film 103Cf and film 104Cf, and to suppress deterioration of the laminated film 103Cf and film 104Cf.

[0403] The temperature for the thermal ALD method is preferably 200°C or lower, more preferably 150°C or lower, and even more preferably 120°C or lower. Furthermore, considering the decomposition temperature of the precursor, 70°C or higher is preferred. Here, for example, 80°C or 100°C is used.

[0404] For the ALD method, it is preferable to use a precursor that can be deposited at the above temperature.

[0405] A metal oxide can be used for the film 105Cf. When forming the oxide, water (H) is used as the reactant in the ALD method. ２ O), oxygen (O ２ ), ozone (O ３ ), hydrogen peroxide (H ２O ２ Oxidizing agents such as ) can be used. H can be used as a reactant. ２ By using O, damage to the laminated film 103Cf and film 104f can be suppressed.

[0406] When the metal oxide used in the film 105Cf contains zinc, diethylzinc, dimethylzinc, bis(2,2,6,6-tetramethyl-3,5-heptanedionic acid) zinc, zinc acetate, etc., can be used as precursors.

[0407] When the metal oxide used in the film 105Cf contains aluminum, the precursor can be trimethylaluminum, triethylaluminum, triisobutylaluminum, dimethylaluminum hydride, tris(dimethylamino)aluminum, tris(diethylamino)aluminum, etc.

[0408] When the metal oxide used in the film 105Cf contains indium, the precursor can be trimethylindium, triethylindium, tris(2,2,6,6-tetramethyl-3,5-heptanedionic acid)indium, cyclopentadienylindium, indium(III) acetylacetonate, (3-(dimethylamino)propyl)dimethylindium, etc.

[0409] When the metal oxide used in the film 105Cf contains gallium, the precursors that can be used include trimethylgallium, triethylgallium, tris(dimethylamide)gallium(III), gallium(III) acetylacetonate, tris(2,2,6,6-tetramethyl-3,5-heptanedionic acid)gallium, dimethylchlorogallium, diethylchlorogallium, and dimethylgallium isopropoxide.

[0410] When the metal oxide used in the film 105Cf contains tin, tetramethyltin, tetraethyltin, tetraethenyltin, tetraallylsin, tributylvinyltin, allyltributyltin, tetrakisdimethylamidetin (IV), tributylstanylacetylene, tributylphenyltin, chlorotrimethyltin, chlorotriethyltin, etc. can be used as precursors.

[0411] If the metal oxide used in the film 105Cf contains hafnium, then tetrakis(ethylmethylamide)hafnium (TEMAHf) or the like can be used as a precursor.

[0412] Here, we will explain an example of a formation method when zinc-aluminum oxide is used as the film 105Cf.

[0413] As the first step, a raw material gas containing a zinc precursor (hereinafter referred to as the first precursor) is introduced into the chamber, and the first precursor is adsorbed onto the surface of the surface to be formed. Here, diethylzinc is used as the precursor. In addition to the precursor, the raw material gas also contains a carrier gas. Nitrogen, argon, or helium can be used as the carrier gas. The carrier gas may flow continuously in the chamber from the first to the fourth step.

[0414] Next, as a second step, an inert gas (such as nitrogen, argon, or helium) is introduced into the chamber to remove excess precursors and reaction products from the chamber. Alternatively, instead of introducing an inert gas into the chamber, excess precursors and reaction products can be removed by vacuum evacuation.

[0415] Next, in the third step, the reactant is introduced into the chamber and reacted with the first precursor adsorbed on the surface of the surface to be formed. Here, H is used as the reactant. ２ Use O.

[0416] Next, in the fourth step, excess reactant and reaction products are removed from the chamber by introducing an inert gas or by vacuum evacuation.

[0417] By performing the first to fourth steps, for example, a layer containing zinc and an oxide can be formed.

[0418] Next, the first to fourth steps described above are repeated a predetermined number of times.

[0419] It should be noted that a layer may not necessarily be formed after performing the first through fourth steps just once; for example, a layer may be formed after repeating the steps several times.

[0420] Next, in the fifth step, a raw material gas containing an aluminum precursor (hereinafter referred to as the first precursor) is introduced into the chamber, and the first precursor is adsorbed onto the surface of the surface to be formed. Here, trimethylaluminum is used as the precursor. In addition to the precursor, the raw material gas also contains a carrier gas. The carrier gas may flow continuously in the chamber from the fifth to the eighth step.

[0421] Next, as the sixth step, an inert gas (such as nitrogen, argon, or helium) is introduced into the chamber to remove excess precursors and reaction products from the chamber. Alternatively, instead of introducing an inert gas into the chamber, excess precursors and reaction products can be removed by vacuum evacuation.

[0422] Next, in the seventh step, the reactant is introduced into the chamber and reacted with the first precursor adsorbed on the surface of the surface to be formed. Here, H is used as the reactant. ２ Use O.

[0423] Next, in the eighth step, excess reactant and reaction products are removed from the chamber by introducing an inert gas or by vacuum evacuation.

[0424] Steps 5 through 8 described above are repeated a predetermined number of times. Then, steps 1 through 4 described above are repeated again a predetermined number of times.

[0425] Here, by adjusting the number of times the first to fourth steps and the number of times the fifth to eighth steps are performed, the film can be formed to a composition suitable for layer 105C. Furthermore, the layering order is not limited to the above.

[0426] For example, one cycle consists of repeating steps 1 through 4 ten times, steps 5 through 8 once, and steps 1 through 4 ten times. By repeating the cycle until the desired thickness of the film 105Cf is reached, a zinc-aluminum oxide with a composition of zinc:aluminum = 20:1 (atomic ratio) can be formed.

[0427] As another example, one cycle consists of repeating steps 1 through 4 five times, steps 5 through 8 once, steps 1 through 4 ten times, steps 5 through 8 once, and steps 1 through 4 five times. By repeating the cycle until the desired thickness of the film 105Cf is reached, a zinc-aluminum oxide with a composition of zinc:aluminum = 10:1 (atomic ratio) can be formed.

[0428] Furthermore, elements contained in the precursor may also be present in the film 105Cf. For example, carbon, halogens, etc., may be present. In particular, the concentration of these elements may increase when the formation temperature is low.

[0429] The thickness of the zinc-aluminum oxide used as the film 105Cf is, for example, 0.5 nm to 100 nm, preferably 1 nm to 30 nm. Furthermore, by setting the thickness of layer 105C to 30 nm or less, the time required for film formation using the ALD method can be shortened. Additionally, by setting the thickness of layer 105C to 30 nm or less, or 20 nm or less, it can function as a carrier transport layer or carrier implantation layer, allowing for suitable transport or implantation of carriers from the electrode 552, thereby providing a light-emitting device with excellent properties.

[0430] Next, a resist mask RES1 is formed on the film 105Cf. Then, using the resist mask RES1 as a mask, the film 105Cf is processed into a predetermined shape to form layers 105A, 105B, and 105C (Figure 14C). Specifically, the parts that overlap with electrodes 551A, 551B, and 551C are left, and the unnecessary parts are etched. By using the materials described above for layers 105A, 105B, and 105C, layers with high stability against oxygen or moisture can be made. In addition, the barrier properties against oxygen or moisture can be enhanced. Furthermore, by forming the film 105Cf that will become layers 105A, 105B, and 105C using the ALD method, dense layers can be made. This may further enhance stability against oxygen or moisture. In addition, the barrier properties against oxygen or moisture can be further enhanced. As described above, layers 105A, 105B, and 105C can be suitably used as hard masks.

[0431] Afterward, remove the resist mask RES1.

[0432] Next, layers 105A, 105B, and 105C are used as a hard mask to process the laminated film 103Cf and film 104Cf into a predetermined shape, forming units 103A, 103B, 103C, layer 104A, layer 104B, and layer 104C (Figure 14D). For example, an oxygen-containing gas can be used as the etching gas.

[0433] Furthermore, the removal of the resist mask RES1 can also be performed after processing the film 105Cf into a predetermined shape to form layers 104A, 104B, and 104C. However, in that case, when removing the resist mask RES1, the sides of units 103A, 103B, and 103C, as well as the sides of layers 104A, 104B, and 104C, are exposed. Therefore, there is a concern that the removal of the resist mask RES1 may cause damage to the sides of units 103A, 103B, and 103C, as well as layers 104A, 104B, and 104C. In addition, the etching process of the resist mask RES1 may etch units 103A, 103B, and 103C, and layers 104A, 104B, and 104C from their sides. Therefore, it is preferable to remove the resist mask RES1 before processing the laminated film 103Cf and film 104Cf.

[0434] Next, an insulating layer 529 is formed (Figure 15A). Specifically, the insulating layer 529 is formed to cover the top surface of layer 105A, the sides of layer 105A, unit 103A, and layer 104A, the top surface of layer 105B, the sides of layer 105B, unit 103B, and layer 104B, the top surface of layer 105C, and the sides of layer 105C, unit 103C, and layer 104C. Furthermore, the covering properties can be improved by forming the insulating layer 529 using the ALD method.

[0435] Next, multiple openings 561 are formed in the insulating layer 529. In Figure 15B, the insulating layer 529 has an opening 561 that overlaps with electrode 551A, an opening 561 that overlaps with electrode 551B, and an opening 561 that overlaps with electrode 551C. As a result, layers 105A, 105B, and 105C are exposed at each of these openings. The openings 561 are provided, for example, to overlap with the light-emitting region of the light-emitting device.

[0436] The insulating layer 529 is preferably made of a material that has an etching selectivity ratio with respect to layers 105A, 105B, and 105C. Specifically, in the etching conditions used to etch the insulating layer 529, it is preferable that the etching rates of layers 105A, 105B, and 105C are sufficiently low.

[0437] For example, an inorganic material can be used as the insulating layer 529. Specifically, for example, aluminum oxide, aluminum oxide nitride, aluminum nitride, aluminum nitride, silicon oxide, silicon oxide nitride, silicon nitride, silicon oxide, hafnium oxide, yttrium oxide, zirconium oxide, gallium oxide, tantalum oxide, magnesium oxide, lanthanum oxide, cerium oxide, neodymium oxide, etc. can be used.

[0438] Furthermore, the insulating layer 529 can be a laminated structure of two or more layers. In the laminated structure, it is preferable that the layer in contact with layers 105A, 105B, and 105C, i.e., the bottommost layer, is made of a material that has an etching selectivity ratio with layers 105A, 105B, and 105C during etching.

[0439] Furthermore, the insulating layer 529 may also have an organic material structure. Alternatively, it may have a laminated structure of a layer having an organic material and a layer having an inorganic material. For example, it may have a laminated structure of a first layer having an organic material and a second layer having an inorganic material located on the first layer.

[0440] For example, either a wet etching method or a dry etching method may be used to form the opening 561. By using the dry etching method, for example, miniaturization of the light-emitting device can be achieved. Also, by using the dry etching method, for example, it may be easier to control the taper angle of the side surface of the opening 561 of the insulating layer 529. By reducing the taper angle of the side surface of the insulating layer 529, the coverage of the side surface of the insulating layer 529 by the electrode 552 can be improved.

[0441] Since layers 105A, 105B, and 105C are highly stable layers, they are less susceptible to etching damage when their surfaces are exposed during the formation of the opening 561. Furthermore, they are less prone to alteration due to etching. Regardless of whether a wet etching method or a dry etching method is used for etching the insulating layer 529, the degradation of the light-emitting device's characteristics and reliability due to etching can be suppressed.

[0442] Next, electrodes 552 are formed on layer 105A, layer 105B, layer 105C, and insulating layer 529 (Figure 15C).

[0443] Furthermore, Figure 15C shows an example configuration in which the display device 700 has a layer 105_2. In this case, for example, after forming an opening 561 in the insulating layer 529, the layer 105_2 is formed before forming the electrode 552, and the electrode 552 is formed after the layer 105_2 is formed. The layer 105_2 can be formed, for example, using a vacuum deposition method.

[0444] The electrode 552 can be formed using one or more of various methods, such as ALD, vacuum deposition, CVD, and sputtering. Here, as an example, an example is shown in which the electrode 552 has a laminated structure of a conductive layer 552_1 and a conductive layer 552_2 on the conductive layer 552_1.

[0445] It is preferable that the conductive layer 552_1 can be formed without exposure to the atmosphere after the layer 105_2 has been formed. It is also preferable that the conductive layer 552_1 is formed by a method that causes minimal damage to the layer 105_2. Here, for example, an Ag:Mg layer is formed as the conductive layer 552_1 using a vacuum deposition method.

[0446] Furthermore, when vacuum deposition is used for the conductive layer 552_1, the resulting film may be anisotropic. Also, achieving a thick film may be difficult. As a result, the coverage of the conductive layer 552_1 may be poor, particularly in areas with uneven surfaces, specifically, for example, in the region between adjacent light-emitting devices, and this coverage may be interrupted.

[0447] The conductive layer 552_2 is preferably formed using a method that provides high coverage. If the coverage is low, the electrode 552 may be cut between adjacent light-emitting devices. Furthermore, the thickness of the conductive layer 552_2 is preferably greater than the thickness of the conductive layer 552_1. By increasing the thickness of the conductive layer 552_2, for example, the cutting of the conductive layer 552_2 can be suppressed regardless of the film formation method of the conductive layer 552_2.

[0448] Here, for example, a zinc-aluminum oxide produced by the ALD method is used as the conductive layer 552_2. This improves the coverage of the electrode 552 and suppresses damage to the EL layer caused by the formation of the electrode 552. The conditions for the ALD method can be referenced from the formation conditions of film 105Cf, etc.

[0449] The conductive layer 552_2 can be formed, for example, using the same manufacturing method as layer 105. This may increase productivity.

[0450] Furthermore, when zinc-aluminum oxide is used as the conductive layer 552_2 and layer 105, the ratio of zinc to aluminum in the conductive layer 552_2 can be adjusted to make it function suitably as an electrode.

[0451] Using the above manufacturing method, a display device according to one aspect of the present invention can be manufactured.

[0452] (Embodiment 2) In this embodiment, a display device according to one aspect of the present invention will be described with reference to Figures 16 and 17.

[0453] Figure 16A is a front view of a display device according to one embodiment of the present invention, and Figure 16B is a front view illustrating a part of Figure 16A. Figure 16C is a cross-sectional view of the cutting lines X1-X2, X3-X4, a pair of pixels 703(i,j), and X5-X6 shown in Figure 16A.

[0454] Figure 17 is a circuit diagram illustrating the configuration of a display device according to one embodiment of the present invention.

[0455] In this specification, variables that take integer values ​​of 1 or more may be used as signs. For example, (p), which includes a variable p that takes an integer value of 1 or more, may be used as part of a sign that identifies any of up to p components. Also, for example, (m, n), which includes a variable m and a variable n that take integer values ​​of 1 or more, may be used as part of a sign that identifies any of up to m × n components.

[0456] <Example 1 of the configuration of the display device 700> A display device 700 according to one aspect of the present invention has an insulating layer 521, an insulating layer 573, and a pair of pixels 703 (i, j) (see Figure 16C).

[0457] The insulating layer 521 has an overlapping region that overlaps with the insulating layer 573. In other words, the insulating layer 521 overlaps with the insulating layer 573 in the overlapping region.

[0458] The superimposed area includes the display area 731 and the sealing area 732. The sealing area 732 also surrounds the display area 731 (see Figure 16B).

[0459] 《Example of the configuration of the display area 731》 The display area 731 comprises a pair of pixels 703(i,j). The pair of pixels 703(i,j) comprises pixels 702A(i,j), pixels 702B(i,j), and pixels 702C(i,j) (see Figures 16B and 16C).

[0460] Pixel 702A(i,j) comprises a pixel circuit 530A(i,j) and a light-emitting device 550A (see Figure 16C). The light-emitting device 550A is electrically connected to the pixel circuit 530A(i,j).

[0461] Furthermore, pixel 702B(i,j) includes a pixel circuit 530B(i,j) and a light-emitting device 550B. The light-emitting device 550B is electrically connected to the pixel circuit 530B(i,j). Similarly, pixel 702C(i,j) includes a light-emitting device 550C (see Figure 16B). For example, the light-emitting device 550C is a blue light-emitting element.

[0462] The light-emitting device 550A is sandwiched between the insulating layer 521 and the insulating layer 573 (see Figure 16C).

[0463] <Example of the composition of layer 521> For example, a film containing silicon and nitrogen or oxygen can be used for the insulating layer 521.

[0464] <Example of the composition of the insulating layer 573> For example, a film containing silicon and nitrogen can be used for the insulating layer 573. Also, for example, the insulating layer 573 is in contact with the insulating layer 521 in the sealing region 732.

[0465] When a film containing silicon and nitrogen is used for the insulating layer 573, the insulating layer 573 has a thickness of 5 nm to 50 nm, preferably 5 nm to 30 nm, and more preferably 5 nm to 20 nm. For example, the insulating layer 573 can be formed using the PEALD method.

[0466] As a result, the light-emitting device 550A is sandwiched between the insulating layer 521 and the insulating layer 573. Similarly, the light-emitting device 550B is sandwiched between the insulating layer 521 and the insulating layer 573. Furthermore, it is possible to suppress the phenomenon of impurities that impair the operating characteristics of the light-emitting device 550A diffusing from the outside to the inside of the display device. In addition, the insulating layer 573 can be formed at a lower temperature compared to the thermal ALD method. Furthermore, it is possible to suppress the phenomenon of the characteristics of the light-emitting device 550A and the light-emitting device 550B being impaired during the manufacturing process. In addition, flexibility can be imparted to the display device. As a result, a novel display device with superior convenience, usefulness, and reliability can be provided.

[0467] <Example 2 of the configuration of the display device 700> In another embodiment of the present invention, the display device 700 has a functional layer 540, a functional layer 520, a color conversion layer 762A, a color conversion layer 762B, a resin layer 764, and a substrate 760 (see Figure 16C). The functional layer 540 overlaps with the functional layer 520.

[0468] The functional layer 540 includes light-emitting devices 550A and 550B. Light-emitting device 550A overlaps with the color conversion layer 762A. Light-emitting device 550B also overlaps with the color conversion layer 762B.

[0469] The functional layer 520 includes a pixel circuit 530A(i,j) and wiring (see Figure 16C). The pixel circuit 530A(i,j) is electrically connected to the wiring. For example, a conductive film provided in the opening 591A of the functional layer 520 can be used for the wiring, and this wiring electrically connects the terminal 519B and the pixel circuit 530A(i,j). The conductive material CP electrically connects the terminal 519B and the flexible printed circuit board FPC1. Alternatively, for example, a conductive film provided in the opening 591B of the functional layer 520 can be used for the wiring.

[0470] <Example 3 of the configuration of the display device 700> In addition, the display device 700 according to one aspect of the present invention has a drive circuit GD and a drive circuit SD (see Figure 16A).

[0471] 《Example of drive circuit GD configuration》 The drive circuit GD supplies a first selection signal and a second selection signal.

[0472] 《Example of drive circuit SD configuration》 The drive circuit SD supplies a first control signal and a second control signal.

[0473] <Example of wiring configuration> The wiring includes conductive film G1(i), conductive film G2(i), conductive film S1(j), conductive film S2(j), conductive film ANO, conductive film VCOM2, and conductive film V0 (see Figure 17).

[0474] Conductive film G1(i) is supplied with a first selection signal, and conductive film G2(i) is supplied with a second selection signal.

[0475] The conductive film S1(j) is supplied with a first control signal, and the conductive film S2(j) is supplied with a second control signal.

[0476] 《Example of Pixel Circuit 530A(i,j) Configuration 1》 The pixel circuit 530A(i,j) is electrically connected to conductive film G1(i) and conductive film S1(j). Conductive film G1(i) supplies a first selection signal, and conductive film S1(j) supplies a first control signal.

[0477] The pixel circuit 530A(i,j) drives the light-emitting device 550A based on a first selection signal and a first control signal. The light-emitting device 550A also emits light.

[0478] The light-emitting device 550A has one electrode electrically connected to the pixel circuit 530A(i,j) and the other electrode electrically connected to the conductive film VCOM2.

[0479] 《Example 2 of the configuration of pixel circuit 530A(i,j)》 The pixel circuit 530A(i,j) includes switch SW21, switch SW22, transistor M21, capacitor C21, and node N21.

[0480] Transistor M21 comprises a gate electrode electrically connected to node N21, a first electrode electrically connected to light-emitting device 550A, and a second electrode electrically connected to conductive film ANO.

[0481] The switch SW21 includes a first terminal electrically connected to node N21, a second terminal electrically connected to conductive film S1(j), and a gate electrode that has the function of controlling a conduction state or a non-conduction state based on the potential of conductive film G1(i).

[0482] The switch SW22 includes a first terminal electrically connected to the conductive film S2(j) and a gate electrode that has the function of controlling a conduction state or a non-conduction state based on the potential of the conductive film G2(i).

[0483] Capacitor C21 comprises a conductive film electrically connected to node N21 and a conductive film electrically connected to the second electrode of switch SW22.

[0484] This allows the image signal to be stored in node N21. Alternatively, the potential of node N21 can be changed using switch SW22. Or, the intensity of the light emitted by the light-emitting device 550A can be controlled using the potential of node N21. As a result, a novel device with superior convenience, usefulness, and reliability can be provided.

[0485] 《Example 3 of the configuration of pixel circuit 530A(i,j)》 The pixel circuit 530A(i,j) includes a switch SW23, a node N22, and a capacitor C22.

[0486] The switch SW23 includes a first terminal electrically connected to the conductive film V0, a ​​second terminal electrically connected to node N22, and a gate electrode that has the function of controlling a conduction state or a non-conduction state based on the potential of the conductive film G2(i).

[0487] Capacitor C22 comprises a conductive film electrically connected to node N21 and a conductive film electrically connected to node N22.

[0488] The first electrode of transistor M21 is electrically connected to node N22.

[0489] This embodiment can be appropriately combined with other embodiments shown in this specification.

[0490] (Embodiment 3) This embodiment describes a display module according to one aspect of the present invention.

[0491] <Display Module> Figure 18 is a perspective view illustrating the configuration of the display module 280.

[0492] The display module 280 includes a display device 700 and an FPC 290 or a connector. The display device 700 includes a display area 80. For example, the display device 700 described in Figure 3A in Embodiment 1 can be used in the display device 100. The light-emitting element is sandwiched and fixed between substrates 71 and 73. Substrate 71 corresponds to substrate 510 shown in Figure 3A, and substrate 73 corresponds to substrate 120Q having a color conversion layer.

[0493] The FPC 290 receives signals and power from an external source and supplies signals and power to the display device 100. An IC may also be mounted on the FPC 290. A connector is a mechanical component that electrically connects conductors, and these conductors can electrically connect the display device 100 to a component it is coupled to. For example, the FPC 290 can be used as a conductor. Furthermore, the connector can disconnect the display device 100 from its coupled component.

[0494] Display Device 100A Figure 19 is a cross-sectional view illustrating the configuration of the display device 100A. The display device 100A can be used, for example, in the display device 100 of the display module 280. The substrate 301 corresponds to the substrate 71 in Figure 18. The substrate 301 is a semiconductor substrate and corresponds to the substrate 510 shown in Figure 3A. The substrate 120Q having a color conversion layer corresponds to the substrate 73 in Figure 18.

[0495] The display device 100A includes a substrate 301, a transistor 310, an element isolation layer 315, an insulating layer 261, a capacitor 240, an insulating layer 255a, an insulating layer 255b, a light-emitting device 61R, a light-emitting device 61G, and a light-emitting device 61B. The insulating layer 261 is provided on the substrate 301A, and the transistor 310 is located between the substrate 301 and the insulating layer 261. The insulating layer 255a is provided on the insulating layer 261, the capacitor 240 is located between the insulating layer 261 and the insulating layer 255a, and the insulating layer 255a is located between the light-emitting device 61R and the capacitor 240, the light-emitting device 61G and the capacitor 240, and the light-emitting device 61B and the capacitor 240.

[0496] [Transistor 310] The transistor 310 has a conductive layer 311, a pair of low-resistance regions 312, an insulating layer 313, and an insulating layer 314, and forms a channel in a part of the substrate 301. 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 substrate 301 has a pair of impurity-doped low-resistance regions 312. These regions function as a source and a drain. The sides of the conductive layer 311 are covered with the insulating layer 314.

[0497] The element isolation layer 315 is embedded in the substrate 301 and is located between two adjacent transistors 310.

[0498] [Capacitor 240] Capacitor 240 has a conductive layer 241, a conductive layer 245, and an insulating layer 243, the insulating layer 243 being located between the conductive layer 241 and the conductive layer 245. 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 the dielectric of the capacitor 240.

[0499] The conductive layer 241 is located on the insulating layer 261 and embedded in the insulating layer 254. The conductive layer 241 is electrically connected to either the source or drain of the transistor 310 by a plug 275 embedded in the insulating layer 261. The insulating layer 243 covers the conductive layer 241. The conductive layer 245 overlaps the conductive layer 241 via the insulating layer 243.

[0500] [Insulating film 255a, insulating layer 255b, and insulating layer 255c] The display device 100A comprises insulating layer 255a, insulating layer 255b, and insulating layer 255c, with insulating layer 255b located between insulating layer 255a and insulating layer 255c.

[0501] [Light-emitting devices 61R, 61G, and 61B] Light-emitting devices 61R, 61G, and 61B are provided on an insulating layer 255c. For example, with respect to the substrate 120Q having a color conversion layer as described in the previous embodiment, light-emitting device 61R is color-converted and emits light 81R, light-emitting device 61G is color-converted and emits light 81G, and light-emitting device 61B emits light 81B as is. The light-emitting devices also have a common layer 174.

[0502] Light-emitting device 61R has a conductive layer 171 and an EL layer 172R, with the EL layer 172R covering the top and sides of the conductive layer 171. Light-emitting device 61G has a conductive layer 171 and an EL layer 172G, with the EL layer 172G covering the top and sides of the conductive layer 171. Light-emitting device 61B has a conductive layer 171 and an EL layer 172B, with the EL layer 172B covering the top and sides of the conductive layer 171.

[0503] The conductive layer 171 is electrically connected to either the source or drain of the transistor 310 by plugs 256 embedded in insulating layers 243, 255a, 255b, and 255c, the conductive layer 241 embedded in insulating layer 254, and plugs 275 embedded in insulating layer 261. The height of the upper surface of insulating layer 255c and the height of the upper surface of plug 256 are equal or approximately equal. Various conductive materials can be used for the plugs.

[0504] [Protective layer 271, protective layer 273, adhesive layer 122] The protective layer 271 is located between adjacent light-emitting devices, for example, light-emitting device 61R and light-emitting device 61G. In addition, the protective layer 273 is provided on light-emitting devices 61R, 61G, and 61B.

[0505] The adhesive layer 122 is bonded to the substrate 120Q having a protective layer 273 and a color conversion layer.

[0506] [Substrate 120Q having a color conversion layer] The substrate 120Q having a color conversion layer corresponds to the substrate 73 in Figure 18. For example, a light-shielding layer can be provided on the side of the substrate 120Q having the color conversion layer that faces the adhesive layer 122. In addition, various optical components can be arranged on the outside of the substrate 120Q having the color conversion layer.

[0507] A film can be used on the substrate 120Q having a color conversion layer. In particular, a film with a low water absorption rate can be preferably used. For example, a water absorption rate of 1% or less is preferred, and 0.1% or less is more preferred. This can suppress changes in the dimensions of the film, as well as the occurrence of wrinkles and other defects. It can also suppress changes in the shape of the display device.

[0508] For example, polarizing plates, phase difference plates, light diffusion layers (e.g., diffusion films), anti-reflective layers, and light-gathering films can be used as optical components.

[0509] A circular polarizer can be superimposed on the display device by using a substrate made of a material with high optical isotropy, in other words, a material with a small birefringence. For example, a material with an absolute retardation (phase difference) value of 30 nm or less, more preferably 20 nm or less, and even more preferably 10 nm or less can be used as the substrate. For example, triacetylcellulose (TAC, also called cellulose triacetate) film, cycloolefin polymer (COP) film, cycloolefin copolymer (COC) film, and acrylic resin film can be used as films with high optical isotropy.

[0510] Furthermore, surface protection layers such as an antistatic film to suppress the adhesion of dust, a water-repellent film to make it difficult for dirt to adhere, a hard coat film to suppress the occurrence of scratches during use, or an impact-absorbing layer may be placed on the outside of the substrate 120. For example, a glass layer or a silica layer (SiO ｘ Layers), DLC (Diamond-Like Carbon), Aluminum Oxide (AlO ｘ Polyester-based materials or polycarbonate-based materials can be used as the surface protective layer. Materials with high transmittance to visible light are preferably used as the surface protective layer. Materials with high hardness are also preferably used as the surface protective layer.

[0511] Display Device 100C Figure 20 is a cross-sectional view illustrating the configuration of the display device 100C. The display device 100C can be used, for example, in the display device 100 of the display module 280 (see Figure 18). The substrate 301 is a semiconductor substrate and corresponds to the substrate 510 shown in Figure 3A. The substrate 120Q having a color conversion layer corresponds to the substrate 73 in Figure 18. In the following description of the display device, parts that are the same as those described earlier may be omitted.

[0512] The display device 100C has a substrate 301B and a substrate 301A. The display device 100C includes a transistor 310B, a capacitor 240, a light-emitting device 61R, a light-emitting device 61G, a light-emitting device 61B, and a transistor 310A. Transistor 310A forms a channel in a part of substrate 301A, and transistor 310B forms a channel in a part of substrate 301B.

[0513] [Insulating layer 345, insulating layer 346] The insulating layer 345 is in contact with the lower surface of the substrate 301B, and the insulating layer 346 is located on top of the insulating layer 261. For example, an inorganic insulating film that can be used for the protective layer 273 can be used for the insulating layer 345 and the insulating layer 346. The insulating layer 345 and the insulating layer 346 function as protective layers and can suppress the phenomenon of impurities diffusing into the substrate 301B and the substrate 301A.

[0514] [Plug 343] The plug 343 penetrates the substrate 301B and the insulating layer 345. The insulating layer 344 covers the sides of the plug 343. For example, an inorganic insulating film that can be used for the protective layer 273 can be used for the insulating layer 344. The insulating layer 344 functions as a protective layer and can suppress the phenomenon of impurities diffusing into the substrate 301B.

[0515] [Conductive layer 342] The conductive layer 342 is located between the insulating layer 345 and the insulating layer 346. Preferably, the conductive layer 342 is embedded in the insulating layer 335, and the surface formed by the conductive layer 342 and the insulating layer 335 is flattened. The conductive layer 342 is electrically connected to the plug 343.

[0516] [Conductive layer 341] The conductive layer 341 is located between the insulating layer 346 and the insulating layer 335. Preferably, the conductive layer 341 is embedded in the insulating layer 336, and the surface formed by the conductive layer 341 and the insulating layer 336 is flattened. The conductive layer 341 is bonded to the conductive layer 342. This electrically connects the substrate 301A to the substrate 301B.

[0517] It is preferable that the conductive layer 341 uses the same conductive material as the conductive layer 342. For example, a metal film containing an element selected from Al, Cr, Cu, Ta, Ti, Mo, and W, or a metal nitride film composed of the above-mentioned elements (e.g., titanium nitride film, molybdenum nitride film, or tungsten nitride film) can be used. In particular, it is preferable to use copper for both the conductive layer 341 and the conductive layer 342. This allows the application of Cu-Cu (copper-copper) direct bonding technology (a technology that achieves electrical conductivity by connecting Cu (copper) pads to each other).

[0518] Display Device 100D Figure 21 is a cross-sectional view illustrating the configuration of the display device 100D. The display device 100D can be used, for example, in the display device 100 of the display module 280 (see Figure 18). The substrate 301 is a semiconductor substrate and corresponds to the substrate 510 shown in Figure 3A. The substrate 120Q having a color conversion layer corresponds to the substrate 73 in Figure 18.

[0519] The display device 100D has a bump 347, which joins the conductive layer 341 and the conductive layer 342. The bump 347 also electrically connects the conductive layer 341 and the conductive layer 342. For example, a conductive material including gold (Au), nickel (Ni), indium (In), or tin (Sn) can be used for the bump 347. Alternatively, solder can be used for the bump 347.

[0520] Furthermore, the display device 100D has an adhesive layer 348. The adhesive layer 348 bonds the insulating layer 345 and the insulating layer 346 together.

[0521] 《Display Device 100E》 Figure 22 is a cross-sectional view illustrating the configuration of the display device 100E. The display device 100E can be used, for example, in the display device 100 of the display module 280 (see Figure 18). The substrate 331 corresponds to the substrate 71 in Figure 18 and to the substrate 510 shown in Figure 3A. The substrate 120Q having a color conversion layer corresponds to the substrate 73 in Figure 18. An insulating substrate or a semiconductor substrate can be used for the substrate 331. The display device 100E has a transistor 320. Note that the display device 100E differs from the display device 100A in that the transistor configuration is an OS transistor.

[0522] [Insulating layer 332] The insulating layer 332 is provided on the substrate 331. For example, a film that is less susceptible to hydrogen or oxygen diffusion than a silicon oxide film can be used for the insulating layer 332. Specifically, an aluminum oxide film, a hafnium oxide film, or a silicon nitride film can be used for the insulating layer 332. As a result, the insulating layer 332 can prevent impurities such as water or hydrogen from diffusing from the substrate 331 to the transistor 320. It can also prevent oxygen from detaching from the semiconductor layer 321 to the insulating layer 332.

[0523] [Transistor 320] The transistor 320 has 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.

[0524] The conductive layer 327 is provided on the insulating layer 332 and functions as the first gate electrode of the transistor 320. The insulating layer 326 covers the conductive layer 327. A portion of the insulating layer 326 functions as the first gate insulating layer. The insulating layer 326 includes an oxide insulating film in at least the region in contact with the semiconductor layer 321. Specifically, it is preferable to use a silicon oxide film or the like. The insulating layer 326 also has a flattened upper surface. The semiconductor layer 321 is provided on the insulating layer 326. A metal oxide film having semiconductor properties can be used for the semiconductor layer 321. A pair of conductive layers 325 are provided in contact with the semiconductor layer 321 and function as the source electrode and drain electrode.

[0525] The indium oxide film that can be used in the semiconductor layer 321 is described below.

[0526] In this specification, indium oxide having at least a crystalline portion or crystalline region in the film is referred to as crystalline indium oxide (crystal IO) or crystalline indium oxide (crystalline IO). Examples of crystal IO or crystalline IO include single-crystal indium oxide, polycrystalline indium oxide, and microcrystalline indium oxide.

[0527] Indium oxide is a semiconductor material with completely different physical properties from oxide semiconductors such as In-Ga-Zn oxide (hereinafter also referred to as IGZO) and zinc oxide.

[0528] This paper describes the carrier concentration dependence of the hole mobility of indium oxide, silicon, and IGZO.

[0529] IGZO tends to exhibit higher hole mobility as the carrier concentration increases. On the other hand, single-crystal indium oxide tends to exhibit higher hole mobility as the carrier concentration decreases. This trend is similar to that of silicon, where lower dopant (impurity) concentrations in the material reduce impurity scattering and increase hole mobility. In other words, the higher the purity and intrinsic nature of single-crystal indium oxide, the higher its hole mobility. From these results, it can be said that single-crystal indium oxide, unlike IGZO, is a material with physical properties similar to silicon. Note that when indium oxide is not single-crystal (e.g., polycrystalline), the trend may differ from that of single crystals.

[0530] The range of carrier concentrations suitable for the channel formation region of a transistor is 1 × 10⁻⁶. １５ cm −３ This range includes, for example, 1 × 10 １４ cm −３ The above is 1 x 10 １８ cm −３ The range is as follows: By sufficiently reducing the carrier concentration, the hole mobility value can be increased to 270 cm⁻¹. ２ It can be expected to be raised to the level of / (V・s).

[0531] Indium oxide can contain elements that lower the carrier concentration. Examples of elements that lower the carrier concentration include magnesium, calcium, zinc, cadmium, and copper. These elements can lower the carrier concentration by substituting for indium. Other examples include nitrogen, phosphorus, arsenic, and antimony. These elements can lower the carrier concentration by substituting for oxygen.

[0532] Elements that reduce carrier concentration can also be called elements that confer p-type properties. Adding elements that reduce carrier concentration to an indium oxide film can make the indium oxide film i-type or substantially i-type. In this case, the concentration of the above-mentioned carrier-reducing element in the indium oxide film is 1 × 10⁻⁶. １６ atoms / cm ３ The above 8 x 10 ２０ atoms / cm ３ The following is preferable: 1 × 10 １６atoms / cm ３ The above 4 x 10 ２０ atoms / cm ３ The following is more preferable: 1 × 10 １６ atoms / cm ３ The above 8 x 10 １９ atoms / cm ３ The following is more preferable: 1 × 10 １６ atoms / cm ３ The above 5 x 10 １９ atoms / cm ３ The following is even more preferable. By using such concentrations, the carrier concentration can be reduced while maintaining the crystal structure of indium oxide.

[0533] On the other hand, electrical resistance can be reduced by increasing the carrier concentration. For example, the suitable carrier concentration range for the source and drain regions of a transistor, or for a resistor or transparent conductive film, is when the carrier concentration value is 1 × 10⁻⁶ ２０ cm −３ This range includes, for example, 1 × 10 １９ cm −３ The above is 1 x 10 ２２ cm −３ The range is as follows: By making the carrier concentration sufficiently high, the resistivity can be increased to 1 × 10⁻⁶. −４ It is expected that the level can be reduced to below Ω·cm.

[0534] Indium oxide may contain elements that increase the carrier concentration. For example, it is preferable to include elements common to the source and drain electrodes of the transistor. Examples of elements that increase the carrier concentration include titanium, zirconium, hafnium, tantalum, tungsten, molybdenum, tin, silicon, and boron. In particular, it is more preferable to use elements in which the oxide is conductive or semiconducting.

[0535] Elements that increase carrier concentration can also be called elements that confer n-type properties. The concentration of the above-mentioned carrier-increasing elements in an indium oxide film is 1 × 10⁻⁶ １６ atoms / cm ３ The above 8 x 10 ２０ atoms / cm ３ The following is preferable: 1 × 10 １６atoms / cm ３ The above 4 x 10 ２０ atoms / cm ３ The following is more preferable: 1 × 10 １６ atoms / cm ３ The above 8 x 10 １９ atoms / cm ３ The following is more preferable: 1 × 10 １６ atoms / cm ３ The above 5 x 10 １９ atoms / cm ３ The following is even more preferable. By using such concentrations, the carrier concentration can be increased while maintaining the crystal structure of indium oxide. Antimony can also function as an element that increases the carrier concentration.

[0536] Because indium oxide is an oxide whose valence electrons can be controlled, the threshold voltage of a transistor using a semiconductor layer containing indium oxide can be controlled. Furthermore, regions with low carrier concentration can be used for the transistor's channel formation region, while regions with high carrier concentration can be used for the transistor's source and drain regions. This makes it possible to create a so-called n-i-n junction (a junction between an n-type region, an i-type region, and an n-type region). Valence electron control in transistors using silicon is generally known. On the other hand, valence electron control in transistors using indium oxide is a novel technological concept that would not normally be conceived. By using this technological concept, it is possible to realize a transistor with high mobility, low off-current, normally-off capability, and high reliability.

[0537] The indium oxide film is preferably crystalline. In particular, the indium oxide film is preferably polycrystalline, and more preferably single-crystal. A single-crystal film does not have grain boundaries. By using a single-crystal film, carrier scattering at grain boundaries can be suppressed, enabling the realization of transistors that exhibit high field-effect mobility. Furthermore, it has the excellent effect of suppressing variations in transistor characteristics caused by these grain boundaries.

[0538] Furthermore, polycrystalline films are preferable because they can reduce carrier scattering and exhibit high field-effect mobility compared to microcrystalline or amorphous films. When using polycrystalline films, it is preferable to use films with the largest possible grain size and few grain boundaries. In a transistor to which a polycrystalline film is applied, if there are no grain boundaries in the channel formation region, or if no grain boundaries are observed, the channel formation region is located within the single-crystal region contained in the polycrystalline film, and therefore it can be considered a transistor to which a single-crystal film is applied.

[0539] The crystallinity of indium oxide can be analyzed, for example, by X-ray diffraction (XRD), transmission electron microscopy (TEM), or electron diffraction (ED). Alternatively, a combination of these methods may be used for analysis.

[0540] Furthermore, in this specification, a semiconductor layer in which no grain boundaries are observed in the channel formation region, a semiconductor layer in which the channel formation region is contained within a single crystal grain, or a semiconductor layer in which the crystal axis directions are the same in at least two regions within the channel formation region can be considered as a single crystal film.

[0541] The channel formation region refers to the region of the semiconductor layer that overlaps with (or faces) the gate electrode via the gate insulating layer, and is located between the region in contact with the source electrode and the region in contact with the drain electrode. The crystal grains, grain boundaries, crystal axes, and crystal orientation in the channel formation region can be confirmed by cross-sectional observation including the semiconductor layer, source electrode, and drain electrode.

[0542] Impurities in the indium oxide film can act as a source of carrier scattering, thus potentially causing a decrease in field-effect mobility and inhibiting crystal growth. Examples of impurities in the indium oxide film include boron and silicon. In the channel-forming region of the indium oxide film, lower concentrations of these impurities are preferable. For example, the concentration of each of the above impurity elements should be 0.1% or less, more preferably 0.01% (100 ppm) or less. Note that elements such as carbon and hydrogen may be present in the deposition gas or precursor during film formation, and may remain in the indium oxide film in higher concentrations than the above impurities.

[0543] Furthermore, indium oxide films can also contain elements that can form trivalent cations, similar to indium, as long as their crystals maintain a cubic crystal structure (Bixbite type). Examples include Group 13 elements of the periodic table such as gallium and aluminum, and Group 3 elements of the periodic table. Since the bonding force of these elements is stronger than that between indium and oxygen, adding these elements to the indium oxide film can reduce oxygen vacancies (V) in the indium oxide film. Ｏ This can suppress the formation of ions. Furthermore, since these elements mainly exist as trivalent cations in the oxide, the carrier concentration of the indium oxide film can be kept low. Therefore, it becomes possible to shift the threshold voltage of the transistor to the positive side. Also, normally-off operation becomes possible. Thus, a transistor with good electrical characteristics can be provided.

[0544] The concentration of the above elements in the indium oxide film is 1 × 10⁻⁶ １６ atoms / cm ３ The above 8 x 10 ２０ atoms / cm ３ The following is preferable: 1 × 10 １６ atoms / cm ３ The above 4 x 10 ２０ atoms / cm ３ The following is more preferable: 1 × 10 １６ atoms / cm ３ The above 8 x 10 １９ atoms / cm ３ The following is more preferable: 1 × 10 １６ atoms / cm３ The above 5 x 10 １９ atoms / cm ３ The following are even more preferable.

[0545] Furthermore, the elements that impart n-type, p-type, and trivalent cations mentioned above can be added to the indium oxide film by methods such as ion doping, ion implantation, and thermal diffusion. Alternatively, the elements that impart n-type, p-type, and trivalent cations mentioned above can be added to the sputtering target, deposition gas, ALD deposition precursor, etc., when depositing the indium oxide film. Alternatively, the elements that impart n-type, p-type, and trivalent cations mentioned above can be auto-doped from the chamber used when depositing the indium oxide film. Auto-doping refers to the automatic addition of elements contained in the chamber components, etc., into the indium oxide film during deposition.

[0546] By using such an indium oxide film in a transistor, the field-effect mobility of the transistor can be increased to 50 cm². ２ / (V·s) or more, preferably 100 cm ２ / (V·s) or more, more preferably 150 cm ２ / (V·s) or more, more preferably 200 cm ２ / (V·s) or more, more preferably 250 cm ２ It can be set to (V・s) or more.

[0547] One of the characteristics of indium oxide films is their higher oxygen permeability (diffusivity) compared to IGZO films. For example, oxygen diffusing into an indium oxide film permeates the film and is released as oxygen molecules. In some cases, it may also be released as water molecules by reacting with hydrogen contained in the film. Furthermore, if there is an oxygen deficiency in the film, diffusing oxygen atoms will fill the deficiency. Because oxygen diffuses easily through indium oxide films, it can be said that oxygen deficiencies are more easily filled in compared to IGZO films.

[0548] Thus, because indium oxide films are more likely to reduce oxygen vacancies in the film compared to IGZO films, applying such indium oxide films to transistors makes it possible to realize transistors with extremely high reliability.

[0549] Furthermore, the indium oxide film diffuses hydrogen. Hydrogen diffusing into the indium oxide film from the outside permeates the film and is released as hydrogen molecules. Alternatively, it reacts with oxygen contained in the film and is released as water molecules.

[0550] Indium oxide is characterized by a small effective electron mass and a large effective hole mass. Furthermore, the effective electron mass of indium oxide is largely independent of the crystal orientation. Therefore, using crystalline indium oxide in transistors allows for the realization of transistors with high field-effect mobility and high frequency characteristics (also known as f-response). Moreover, due to the large effective hole mass, transistors with extremely low off-currents can be realized. For example, by applying an indium oxide film to a vertical transistor, the off-current per 1 μm of channel width is 1 fA (1 × 10⁻¹⁶) at 125°C. −１５ A) Less than or equal to, or 1aA (1 × 10 −１８ A) Less than or equal to 1aA (1 × 10) in a room temperature (25°C) environment. −１８ A) Less than or equal to, or 1zA (1 × 10⁻¹⁰ −２１ A) The following is possible. Furthermore, because indium oxide has a smaller effective electron mass and a larger effective hole mass than silicon, it may be possible to realize transistors with higher field-effect mobility and lower off-current than Si transistors.

[0551] It is preferable to provide a seed layer so as to be in contact with at least a portion of the crystalline indium oxide film. It is preferable to use a material containing crystals with a small difference in lattice constant (also called lattice mismatch) with the indium oxide for the seed layer. This improves the crystallinity of the indium oxide film. A substrate (e.g., a single-crystal substrate) may be used as one of the layers in contact with at least a portion of the crystalline indium oxide film.

[0552] One method for evaluating the degree of lattice mismatch is to use the following lattice mismatch value. The lattice mismatch Δa [%] of the crystals in the formed film (in this case, the indium oxide film) relative to the crystals in the seed layer is given by Δa = ((L １ -L ２ ) / L ２ It is calculated as ) × 100. Here L １ L is the length of the unit cell vector of the crystals in the formed film, or the lattice constant. ２ This is the length of the unit cell vector of the crystal in the seed layer, or the lattice constant.

[0553] The lattice mismatch Δa between the seed layer and the indium oxide film is preferably small in absolute value, and most preferably zero. For example, Δa can be -5% or more and 5% or less, preferably -4% or more and 4% or less, more preferably -3% or more and 3% or less, and even more preferably -2% or more and 2% or less.

[0554] Here, the indium oxide crystal has a cubic structure (bixbite type). For example, yttria-stabilized zirconia (YSZ) crystals can have a cubic structure (fluorite type). The lattice mismatch of the indium oxide crystal with respect to the cubic YSZ crystal is in the range of -2% to 2%, and a single crystal film of indium oxide can be epitaxially grown on a YSZ substrate.

[0555] Furthermore, the crystal structure of the seed layer and the crystal structure of the indium oxide film do not necessarily have to be the same in terms of crystal system or crystal orientation. For example, a film with a hexagonal or trigonal crystal structure can be used beneath an indium oxide film with a cubic crystal structure. For example, by setting the crystal orientation of the surface of the seed layer to

[001] and the crystal orientation of the underside of the indium oxide film to

[111] , the requirements related to crystal orientation necessary for epitaxial growth can be met. Examples of hexagonal or trigonal crystals include wurtzite-type structures and YbFe. ２ O ４ Type structure, Yb ２ Fe ３ O ７ These include type structures and their modified type structures. YbFe ２ O４ Type structure or Yb ２ Fe ３ O ７ An example of a crystal having a type structure is IGZO.

[0556] [Insulating layer 328, insulating layer 264] The insulating layer 328 covers the top and side surfaces of the pair of conductive layers 325, as well as the side surfaces of the semiconductor layer 321, etc. The insulating layer 264 is provided on the insulating layer 328 and functions as an interlayer insulating layer. The insulating layer 328 and the insulating layer 264 also have openings, and these openings reach the semiconductor layer 321. For example, an insulating film similar to that of the insulating layer 332 can be used for the insulating layer 328. As a result, the insulating layer 328 can prevent the diffusion of impurities such as water or hydrogen from the insulating layer 264 into the semiconductor layer 321. It can also prevent oxygen from being released from the semiconductor layer 321.

[0557] [Insulating layer 323] The insulating layer 323 is in contact with the sides of the insulating layer 264, insulating layer 328, and conductive layer 325, as well as the upper surface of the semiconductor layer 321, within the opening described above.

[0558] [Conductive layer 324] The conductive layer 324 is embedded inside the opening described above, in contact with the insulating layer 323. The conductive layer 324 has a flattened upper surface, and its height is equal to or approximately equal to the upper surface of the insulating layer 323 and the upper surface of the insulating layer 264. The conductive layer 324 functions as a second gate electrode, and the insulating layer 323 functions as a second gate insulating layer.

[0559] [Insulating layer 329, insulating layer 265] The insulating layer 329 covers the conductive layer 324, the insulating layer 323, and the insulating layer 264. The insulating layer 265 is provided on the insulating layer 329 and functions as an interlayer insulating layer. For example, an insulating film similar to that used for insulating layers 328 and 332 can be used for the insulating layer 329. This prevents impurities such as water or hydrogen from diffusing from the insulating layer 265 to the transistor 320.

[0560] [Plug 274] The plug 274 is embedded in the insulating layers 265, 329, 264, and 328, and is electrically connected to one of the pair of conductive layers 325. The plug 274 has conductive layers 274a and 274b. Conductive layer 274a is in contact with the sides of the openings of the insulating layers 265, 329, 264, and 328. It also covers a portion of the upper surface of the conductive layer 325. Conductive layer 274b is in contact with the upper surface of conductive layer 274a. For example, a conductive material that does not readily allow hydrogen and oxygen to diffuse can be suitably used for conductive layer 274a.

[0561] Display Device 100F Figure 23 is a cross-sectional view illustrating the configuration of the display device 100F. The display device 100F has a configuration in which transistor 320A and transistor 320B are stacked. Both transistor 320A and transistor 320B are made of oxide semiconductors, and channels are formed in the oxide semiconductors. Note that the configuration is not limited to stacking two transistors, but for example, a configuration in which three or more transistors are stacked may also be used.

[0562] The configuration of transistor 320A and its surrounding components is the same as that of transistor 320 and its surrounding components in the display device 100E. Furthermore, the configuration of transistor 320B and its surrounding components is the same as that of transistor 320 and its surrounding components in the display device 100E.

[0563] Substrate 331 corresponds to substrate 71 in Figure 18 and to substrate 510 shown in Figure 3A. Furthermore, substrate 120Q, which has a color conversion layer, corresponds to substrate 73 in Figure 18.

[0564] Display Device 100G Figure 24 is a cross-sectional view illustrating the configuration of the display device 100G. Substrate 301 is a semiconductor substrate and corresponds to substrate 510 shown in Figure 3A. Substrate 120Q, which has a color conversion layer, corresponds to substrate 73 in Figure 18. The display device 100G has a configuration in which transistor 310 and transistor 320 are stacked. The channel of transistor 310 is formed in substrate 301. Transistor 320 is made of a metal oxide, and its channel is formed in the oxide semiconductor.

[0565] The insulating layer 261 covers the transistor 310, and the conductive layer 251 is provided on the insulating layer 261. The insulating layer 262 covers the conductive layer 251, and the conductive layer 252 is provided on the insulating layer 262. In addition, the insulating layers 263 and 332 cover the conductive layer 252. The conductive layer 251 and the conductive layer 252 each function as wiring.

[0566] The transistor 320 is provided on the insulating layer 332, and the insulating layer 265 covers the transistor 320. The capacitor 240 is also provided on the insulating layer 265, and the capacitor 240 is electrically connected to the transistor 320 by a plug 274.

[0567] For example, transistor 320 can be used in the transistors that constitute the pixel circuit. Also, for example, transistor 310 can be used in the transistors that constitute the pixel circuit, or in the drive circuit (gate driver circuit, source driver circuit, etc.) for driving the pixel circuit. Furthermore, transistors 310 and 320 can be used in various circuits such as arithmetic circuits or memory circuits. This allows, for example, the drive circuit to be placed not only directly below the light-emitting device but also directly below the pixel circuit. In addition, the display device can be made smaller compared to a configuration in which the drive circuit is placed around the display area.

[0568] This embodiment can be implemented in appropriate combination with other embodiments described herein, at least in part.

[0569] (Embodiment 4) This embodiment describes a display module according to one aspect of the present invention.

[0570] <Display Module> Figure 25 is a perspective view illustrating the configuration of the display module.

[0571] The display module includes a display device 100, an IC (integrated circuit), and an FPC 177 or connector. For example, the display device described in Embodiment 1 can be used as the display device 100.

[0572] The display device 100 is electrically connected to the IC 176 and the FPC 177. The FPC 177 receives signals and power from an external source and supplies signals and power to the display device 100. A connector is a mechanical component that electrically connects conductors, and these conductors can electrically connect the display device 100 to a component to which it is coupled. For example, the FPC 177 can be used as a conductor. The connector can also disconnect the display device 100 from its coupled component.

[0573] The display module includes IC176. For example, IC176 can be mounted on the substrate 14b using a COG (Chip On Glass) method or the like. Alternatively, IC176 can be mounted on the FPC using a COF (Chip On Film) method or the like. Furthermore, for example, a gate driver circuit or a source driver circuit can be used for IC176.

[0574] The display module may be equipped with a touch sensor. For example, a projected capacitive touch sensor comprises electrodes RX and TX, with an insulating layer placed between electrodes RX and TX. This creates a capacitance between electrodes RX and TX. Furthermore, when a pulse signal is supplied to electrode TX, the change in projected capacitance between electrode TX and the sensor can be detected using electrode RX. In addition, the position of the user's finger on the display module can be detected using the touch sensor.

[0575] Figure 26A is a cross-sectional view illustrating the configuration of the display device 100H.

[0576] The display device 100H includes a display unit 37b, a connection unit 140, a circuit 164, and wiring 165, etc. The display device 100H also has a substrate 16b and a substrate 14b, with substrate 16b being bonded to substrate 14b.

[0577] Substrate 16b is the same glass substrate as substrate 14b, and substrate 16b is provided with a color conversion layer 762A, a color conversion layer 762B, a resin layer 764, and a protective layer 765.

[0578] The protective layer 765 can be, for example, a single-layer structure or a multi-layer structure including at least an inorganic insulating film. Suitable inorganic insulating materials for the protective layer 765 include oxides or nitrides such as silicon oxide, silicon oxide nitride, silicon oxide nitride, silicon nitride, aluminum oxide, aluminum oxide nitride, and hafnium oxide. Alternatively, semiconductor materials such as indium gallium oxide and indium gallium zinc oxide may be used as the protective layer 765. Aluminum oxide and silicon nitride are particularly preferred due to their high barrier properties against water.

[0579] The display device 100H has one or more connection portions 140. The connection portions 140 can be provided on the outside of the display unit 37b. For example, they can be provided along one side of the display unit 37b, or they can be provided to surround multiple sides, for example, all four sides. At the connection portion 140, the common electrode of the light-emitting device is electrically connected to a conductive layer, and the conductive layer supplies a predetermined potential to the common electrode.

[0580] The wiring 165 is supplied with signals and power from the FPC 177 or IC 176. The wiring 165 supplies signals and power to the display unit 37b and the circuit 164.

[0581] For example, a gate driver circuit can be used in circuit 164.

[0582] The display device 100H includes a substrate 14b, a substrate 16b, a transistor 201, a transistor 205, a light-emitting device 63R, a light-emitting device 63G, and a light-emitting device 63B (see Figure 26A). For example, the light emitted from light-emitting device 63R passes through the color conversion layer 762A to become red light 83R, the light emitted from light-emitting device 63G passes through the color conversion layer 762B to become green light 83G, and light-emitting device 63B emits blue light 83B. Various optical components can be arranged on the outside of the substrate 16b. For example, a polarizing plate, a phase difference plate, a light diffusion layer (e.g., a diffusion film), an anti-reflective layer, and a light-collecting film can be arranged.

[0583] For example, the light-emitting devices described in Embodiments 1 to 3 can be used as light-emitting device 63R, light-emitting device 63G, and light-emitting device 63B.

[0584] The light-emitting device has a conductive layer 171, which functions as a pixel electrode. The conductive layer 171 has recesses, which overlap with openings provided in the insulating layers 214, 215, and 213. The transistor 205 has a conductive layer 222b, which is electrically connected to the conductive layer 171.

[0585] The display device 100H has an insulating layer 272. The insulating layer 272 covers the edges of the EL layer 172R, the edges of the EL layer 172G, and the edges of the EL layer 172B (see Figure 26A).

[0586] The display device 100H has a protective layer 273 and an adhesive layer 142. The protective layer 273 covers the light-emitting devices 63R, 63G, and 63B. The adhesive layer 142 adheres the protective layer 273 to the substrate 16b. A color conversion layer 762A is pre-formed on the substrate 16b and fixed in a position overlapping with the light-emitting device 63R. A protective layer 765 covering the color conversion layer 762A is formed on the substrate 16b.

[0587] The adhesive layer 142 fills the space between the protective layer 765 and the protective layer 273. For example, the adhesive layer 142 may be formed in a frame shape so as not to overlap with the light-emitting device, and a resin different from that of the adhesive layer 142 may be filled into the area surrounded by the adhesive layer 142, the substrate 16b, and the protective layer 273. Alternatively, an inert gas (such as nitrogen or argon) may be filled into the area to apply a hollow sealing structure. For example, materials that can be used for the adhesive layer 122 can be applied to the adhesive layer 142.

[0588] The display device 100H has a connection portion 140, which includes a conductive layer 168. The conductive layer 168 is supplied with a power potential. The light-emitting device has a conductive layer 173, and the conductive layer 168 is electrically connected to the conductive layer 173, which is supplied with a power potential. The conductive layer 173 functions as a common electrode. Alternatively, for example, a single conductive film can be processed to form the conductive layer 171 and the conductive layer 168.

[0589] The display device 100H is a top-emission type. The light-emitting device emits light towards the substrate 16b. The conductive layer 171 contains a material that reflects visible light, and the conductive layer 173 transmits visible light.

[0590] [Insulating layer 211, insulating layer 213, insulating layer 215, insulating layer 214] Insulating layers 211, 213, 215, and 214 are provided on the substrate 14b in this order. The number of insulating layers is not limited and may be a single layer or two or more layers.

[0591] For example, inorganic insulating films can be used for insulating layer 211, insulating layer 213, and insulating layer 215. For example, silicon nitride film, silicon oxynitride film, silicon oxide film, silicon nitride oxide film, aluminum oxide film, or aluminum nitride film can be used. Alternatively, hafnium oxide film, yttrium oxide film, zirconium oxide film, gallium oxide film, tantalum oxide film, magnesium oxide film, lanthanum oxide film, cerium oxide film, or neodymium oxide film may be used. Furthermore, two or more of the above insulating films may be laminated together.

[0592] The insulating layer 215 and insulating layer 214 cover the transistor. The insulating layer 214 functions as a planarization layer. For example, it is preferable to use a material that does not easily allow impurities such as water and hydrogen to diffuse for the insulating layer 215 or insulating layer 214. This effectively suppresses the phenomenon of impurities diffusing into the transistor from the outside. It also improves the reliability of the display device.

[0593] For example, an organic insulating layer can be suitably used as the insulating layer 214. Specifically, acrylic resin, polyimide resin, epoxy resin, polyamide resin, polyimidoamide resin, siloxane resin, benzocyclobutene resin, phenol resin, and precursors of these resins can be used as the organic insulating layer. Furthermore, a laminated structure of an organic insulating layer and an inorganic insulating layer can be used as the insulating layer 214. This allows the outermost layer of the insulating layer 214 to be used as an etching protection layer. For example, when processing the conductive layer 171 into a predetermined shape, the phenomenon of recesses forming in the insulating layer 214 can be avoided, and this can be suppressed.

[0594] [Transistor 201, Transistor 205] Transistors 201 and 205 are both formed on substrate 14b. These transistors can be manufactured using the same materials and the same process.

[0595] Transistors 201 and 205 have a conductive layer 221, an insulating layer 211, conductive layers 222a and 222b, a semiconductor layer 231, an insulating layer 213, and a conductive layer 223. The insulating layer 211 is located between the conductive layer 221 and the semiconductor layer 231. The conductive layer 221 functions as a gate, and the insulating layer 211 functions as a first gate insulating layer. The conductive layers 222a and 222b function as a source and drain. The insulating layer 213 is located between the conductive layer 223 and the semiconductor layer 231. The conductive layer 223 functions as a gate, and the insulating layer 213 functions as a second gate insulating layer. Here, the same hatching pattern is applied to multiple layers obtained by processing the same conductive film.

[0596] The transistor structure of the display device of this embodiment is not particularly limited. For example, a planar transistor, a staggered transistor, or an inverse staggered transistor can be used. Furthermore, either a top-gate or bottom-gate transistor structure may be used. Alternatively, gates may be provided above and below the semiconductor layer in which the channel is formed.

[0597] Transistors 201 and 205 are configured in which a semiconductor layer on which a channel is formed is sandwiched between two gates. The transistors may be driven by connecting the two gates and supplying them with the same signal. Alternatively, the threshold voltage of the transistors may be controlled by applying a potential to control the threshold voltage to one of the two gates and a potential to drive the other gate.

[0598] The crystallinity of the semiconductor layer of the transistor is not particularly limited; amorphous semiconductors, crystalline semiconductors (microcrystalline semiconductors, polycrystalline semiconductors, single-crystal semiconductors, or semiconductors having a crystalline region in part) may be used. Using a crystalline semiconductor is preferable because it can suppress the degradation of transistor characteristics.

[0599] The semiconductor layer of the transistor preferably has a metal oxide. In other words, it is preferable to use an OS transistor as the transistor in the display device of this embodiment.

[0600] [Semiconductor Layer] For example, a metal oxide (also called an oxide semiconductor) exhibiting semiconductor properties can be used as the semiconductor layer. As an oxide semiconductor, an oxide semiconductor such as indium oxide or In-Ga-Zn oxide (IGZO) can be used. Alternatively, the semiconductor layer of the transistor may have silicon. Examples of silicon include amorphous silicon and crystalline silicon (low-temperature polysilicon, single-crystal silicon, etc.).

[0601] In addition, metal oxides that can be used in semiconductor layers include tin oxide, zinc oxide, indium tin oxide (In-Sn oxide), indium titanium oxide (In-Ti oxide), indium gallium oxide, indium tungsten oxide, indium zinc oxide (In-Zn oxide), indium gallium aluminum oxide, indium gallium tin oxide, gallium zinc oxide, aluminum zinc oxide, indium aluminum zinc oxide, indium tin zinc oxide (In-Sn-Zn oxide), indium titanium zinc oxide (In-Ti-Zn oxide), indium gallium zinc oxide (In-Ga-Zn oxide), indium gallium tin zinc oxide (In-Ga-Sn-Zn oxide), and indium gallium aluminum zinc oxide. Alternatively, silicon-containing indium tin oxide, gallium tin oxide, aluminum tin oxide, etc., can also be used.

[0602] When the metal oxide used in the semiconductor layer is an In-M-Zn oxide, it is preferable that the atomic ratio of In in the In-M-Zn oxide is equal to or greater than the atomic ratio of M. Examples of such atomic ratios of metal elements in an In-M-Zn oxide include: In:M:Zn = 1:1:1 or close to it, In:M:Zn = 1:1:1.2 or close to it, In:M:Zn = 1:3:2 or close to it, In:M:Zn = 1:3:4 or close to it, In:M:Zn = 2:1:3 or close to it, In:M:Zn = 3:1:2 or close to it, and In:M:Zn = 4:2 Compositions include In:M:Zn=3 or nearby, In:M:Zn=4:2:4.1 or nearby, In:M:Zn=5:1:3 or nearby, In:M:Zn=5:1:6 or nearby, In:M:Zn=5:1:7 or nearby, In:M:Zn=5:1:8 or nearby, In:M:Zn=6:1:6 or nearby, and In:M:Zn=5:2:5 or nearby. Nearby compositions include a range of ±30% of the desired atomic ratio.

[0603] For example, when describing an atomic ratio of In:Ga:Zn = 4:2:3 or a composition close to that, it includes cases where, when In is set to 4, Ga is between 1 and 3, and Zn is between 2 and 4. Also, when describing an atomic ratio of In:Ga:Zn = 5:1:6 or a composition close to that, it includes cases where, when In is set to 5, Ga is greater than 0.5 and 2 or less, and Zn is between 5 and 7. Furthermore, when describing an atomic ratio of In:Ga:Zn = 1:1:1 or a composition close to that, it includes cases where, when In is set to 1, Ga is greater than 0.5 and 2 or less, and Zn is greater than 0.5 and 2 or less.

[0604] Furthermore, the semiconductor layer may have two or more metal oxide layers with different compositions. For example, a laminated structure can be suitably used in which a first metal oxide layer has a composition of In:M:Zn = 1:3:4 [atomic ratio] or close to that, and a second metal oxide layer provided on the first metal oxide layer has a composition of In:M:Zn = 1:1:1 [atomic ratio] or close to that. In addition, it is particularly preferable to use gallium or aluminum as element M.

[0605] Alternatively, a transistor using silicon as the channel-forming region (Si transistor) may be used. Examples of silicon include single-crystal silicon, polycrystalline silicon, and amorphous silicon. In particular, a transistor having low-temperature polysilicon (LTPS: Low Temperature Poly Silicon) in the semiconductor layer (also called an LTPS transistor) can be used. LTPS transistors have high field-effect mobility and good frequency characteristics.

[0606] By using Si transistors such as LTPS transistors, circuits that need to be driven at high frequencies (e.g., data driver circuits) can be fabricated on the same board as the display unit. This simplifies the external circuits implemented in the display device, reducing component and mounting costs.

[0607] OS transistors have extremely high field-effect mobility compared to transistors using amorphous silicon. Furthermore, OS transistors exhibit remarkably low source-drain leakage current (also called off-current) in the off state, allowing them to retain charge stored in a capacitor connected in series with the transistor for extended periods. Additionally, the application of OS transistors can reduce the power consumption of display devices.

[0608] Furthermore, to increase the luminescence brightness of the light-emitting device included in the 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 the drive transistor included in the pixel circuit. Compared to Si transistors, OS transistors have a higher breakdown voltage between the source and drain, so a higher voltage can be applied to the source-drain of an OS transistor. Therefore, by using an OS transistor as the drive transistor included in the pixel circuit, the amount of current flowing through the light-emitting device can be increased, thereby increasing the luminescence brightness of the light-emitting device.

[0609] Furthermore, when the transistor is driven in the saturation region, OS transistors can reduce the change in source-drain current in response to changes in gate-source voltage compared to Si transistors. Therefore, by using OS transistors as driving transistors in the pixel circuit, the current flowing between the source and drain can be precisely controlled by controlling the gate-source voltage. Consequently, the amount of current flowing to the light-emitting device can be controlled. This allows for an increase in the number of grayscale levels in the pixel circuit.

[0610] Furthermore, in terms of the saturation characteristics of the current flowing when a transistor is driven in the saturation region, OS transistors can supply a more stable current (saturation current) than Si transistors, even when the source-drain voltage gradually increases. Therefore, by using an OS transistor as a driving transistor, a stable current can be supplied to a light-emitting device even if there are variations in the current-voltage characteristics of the light-emitting device. In other words, when an OS transistor is driven in the saturation region, the source-drain current remains almost unchanged even when the source-drain voltage is increased. Thus, the luminescence brightness of the light-emitting device can be stabilized.

[0611] As described above, by using OS transistors in the drive transistors included in the pixel circuit, it is possible to suppress black level distortion, increase luminescence brightness, enable multi-gradation, and suppress variations in light-emitting devices.

[0612] The transistors in circuit 164 and the transistors in the display unit 107 may have the same structure or different structures. The structures of the multiple transistors in circuit 164 may all be the same or there may be two or more different structures. Similarly, the structures of the multiple transistors in the display unit 107 may all be the same or there may be two or more different structures.

[0613] All of the transistors in the display unit 107 may be OS transistors, or all of the transistors in the display unit 107 may be Si transistors. Alternatively, some of the transistors in the display unit 107 may be OS transistors and the rest may be Si transistors.

[0614] For example, by using both an LTPS transistor and an OS transistor in the display unit 107, a display device with low power consumption and high driving capability can be realized. Furthermore, a configuration combining an LTPS transistor and an OS transistor is sometimes referred to as LTPO. It is preferable, for example, to use an OS transistor as a switch to control the conduction and non-conductivity of wiring, and an LTPS transistor as a transistor to control current.

[0615] For example, one of the transistors in the display unit 107 functions as a transistor for controlling the current flowing to the light-emitting device, and can be called a drive transistor. Either the source or the drain of the drive transistor is electrically connected to the pixel electrode of the light-emitting device. It is preferable to use an LTPS transistor for this drive transistor. This makes it possible to increase the current flowing to the light-emitting device.

[0616] On the other hand, one of the transistors in the display unit 107 functions as a switch for controlling the selection and deselection of pixels, and can also be called a selection transistor. The gate of the selection transistor is electrically connected to the gate line, and either the source or the drain is electrically connected to the signal line. It is preferable to use an OS transistor for the selection transistor. This allows the gradation of pixels to be maintained even when the frame frequency is significantly reduced (for example, 1 fps or less), and thus power consumption can be reduced by stopping the driver when displaying a still image.

[0617] Thus, a display device according to one aspect of the present invention can combine a high aperture ratio, high resolution, high display quality, and low power consumption.

[0618] Furthermore, one embodiment of the present invention is a display device having an OS transistor and an MML structured light-emitting device. This configuration makes it possible to extremely reduce the leakage current that can flow through the transistor and the leakage current that can flow between adjacent light-emitting devices. With this configuration, when an image is displayed on the display device, the observer can observe one or more of the following: image sharpness, image clarity, high saturation, and high contrast ratio. Moreover, by having an extremely low leakage current that can flow through the transistor and lateral leakage current between light-emitting devices, it is possible to achieve a display with as little light leakage (so-called black floating) as possible, for example, when displaying black.

[0619] In particular, MML-structured light-emitting devices can significantly reduce the current flowing between adjacent light-emitting devices.

[0620] [Transistor 209, Transistor 210] Figures 26B and 26C are cross-sectional views illustrating another example of a transistor cross-sectional structure that can be used in the display device 100H.

[0621] Transistors 209 and 210 have a conductive layer 221, an insulating layer 211, a semiconductor layer 231, a conductive layer 222a, a conductive layer 222b, an insulating layer 225, a conductive layer 223, and an insulating layer 215. The semiconductor layer 231 has a channel-forming region 231i and a pair of low-resistance regions 231n. The insulating layer 211 is located between the conductive layer 221 and the channel-forming region 231i. The conductive layer 221 functions as a gate, and the insulating layer 211 functions as a first gate insulating layer. The insulating layer 225 is located at least between the conductive layer 223 and the channel-forming region 231i. The conductive layer 223 functions as a gate, and the insulating layer 225 functions as a second gate insulating layer. The conductive layer 222a is electrically connected to one of the pair of low-resistance regions 231n, and the conductive layer 222b is electrically connected to the other of the pair of low-resistance regions 231n. The insulating layer 215 covers the conductive layer 223. The insulating layer 218 further covers the transistor.

[0622] [Example of the configuration of the insulating layer 225 1] In the transistor 209, the insulating layer 225 covers the top and side surfaces of the semiconductor layer 231 (see Figure 26B). The insulating layer 225 and the insulating layer 215 have openings, and at these openings, the conductive layer 222a and the conductive layer 222b are electrically connected to the low-resistance region 231n, respectively. Of the conductive layer 222a and the conductive layer 222b, one functions as a source and the other functions as a drain.

[0623] [Example 2 of the configuration of the insulating layer 225] In the transistor 210, the insulating layer 225 overlaps with the channel formation region 231i of the semiconductor layer 231, but does not overlap with the low-resistance region 231n (see Figure 26C). For example, the insulating layer 225 can be fabricated by using the conductive layer 223 as a mask and processing it into a predetermined shape. The insulating layer 215 covers the insulating layer 225 and the conductive layer 223. The insulating layer 215 also has an opening, and the conductive layer 222a and the conductive layer 222b are electrically connected to the low-resistance region 231n, respectively.

[0624] [Connection part 204] The connection part 204 is provided on the substrate 14b. The connection part 204 is...

Claims

The device comprises a transistor, a pixel electrode connected to the transistor, an EL layer on the pixel electrode, and an upper electrode on the EL layer. The EL layer comprises a first layer and a second layer on the first layer, It has a color conversion layer that overlaps with the EL layer, The first layer described above includes a luminescent material, The second layer is a display device comprising zinc and aluminum. 　 The display device according to claim 1, wherein the second layer has a region where the ratio of the number of zinc atoms to the number of aluminum atoms is zinc:aluminum = X:1, and X is 2 or more and 200 or less. 　 A display device according to claim 1, wherein the color conversion layer is a color conversion layer using quantum dots. 　 In claim 1, the EL layer has a third layer between the first layer and the second layer, The third layer comprises an electron-transporting material, wherein the display device is a device. 　 A display device according to claim 1, wherein the light-emitting material is a blue light-emitting material or a green light-emitting material. 　 A display device according to claim 1, having a coloring layer that overlaps with the color conversion layer. 　 A display device according to claim 1, wherein the semiconductor layer of the transistor is indium oxide.

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