Display devices, display modules, and electronic devices

Abstract

To provide a long-life display device. [Solution] A display device having a first light-emitting device and a second light-emitting device. The first light-emitting device has a first electrode and a common electrode. The second light-emitting device has a second electrode and a common electrode. The first light-emitting device has, in order from the electrode side that functions as the anode among the first electrode and the common electrode, a first light-emitting layer and an electron transport layer. The second light-emitting device has a second light-emitting layer between the second electrode and the common electrode. The first light-emitting layer has a first organic compound that emits light of a first color. The second light-emitting layer has a second organic compound that emits light of a second color. The electron transport layer has a third organic compound and a first substance. The third organic compound is an electron-transporting material. The first substance is a metal, a metal salt, a metal oxide, or an organometallic salt. The electron transport layer has a first region and a second region in which the concentrations of the first substance are different from each other.

Description

[Technical Field]

[0001] One aspect of the present invention relates to a display device, a display module, and electronic equipment.

[0002] Furthermore, one aspect of the present invention is not limited to the above-mentioned technical field. For example, semiconductor devices, display devices, light-emitting devices, energy storage devices, memory devices, electronic devices, lighting devices, Input devices (e.g., touch sensors), input / output devices (e.g., touch panels), and Examples of these driving methods, or methods for manufacturing them, can be given. [Background technology]

[0003] In recent years, display devices have been expected to have applications in a variety of fields. For example, applications of large-scale display devices. Examples include household television equipment (also called television or television receiver), and Digital Signage (electronic signboards), PID (Public Examples include information displays, etc. Also, mobile information terminals and As a result, development is progressing on smartphones and tablet devices equipped with touch panels.

[0004] As a display device, for example, a light-emitting device (also called a light-emitting element) has been developed. It is being done. Electroluminescence, Light-emitting devices (also called EL devices or EL elements) that utilize the phenomenon (referred to as EL below) are thin It is easy to reduce the size, can respond quickly to input signals, and uses a DC low-voltage power supply. It has features such as being drivable, and its application to display devices is being considered. For example, see the Patent Document. 1. A flexible light-emitting device to which an organic EL device (also called an organic EL element) is applied. The location has been disclosed. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2014-197522 [Overview of the project] [Problems that the invention aims to solve]

[0006] One aspect of the present invention aims to provide a long-life display device. One of the objectives of the present invention is to provide a highly reliable display device. One aspect of the present invention is a large-scale One objective of the present invention is to provide a display device. One aspect of the present invention provides a highly productive display device. One objective of the present invention is to provide a display device with high display quality. This will be one of the challenges.

[0007] Furthermore, the description of these problems does not preclude the existence of other problems. One aspect of the present invention is It is not necessarily required to resolve all of these issues. Specifications, drawings, invoices. It is possible to extract other issues from the descriptions in the sections. [Means for solving the problem]

[0008] One aspect of the present invention is a display device having a first light-emitting device and a second light-emitting device. The first light-emitting device has a first electrode and a common electrode. The second light-emitting device has a first electrode and a common electrode. It has two electrodes and a common electrode. The first light-emitting device has, of the first electrodes and the common electrode Starting from the electrode side which functions as the anode, it has a first light-emitting layer and an electron transport layer. The light-emitting device has a second light-emitting layer between the second electrode and the common electrode. It has a first organic compound that emits light of a first color. The second light-emitting layer emits light of a second color. It has a second organic compound that emits. The electron transport layer has a third organic compound and a first substance. It has. The third organic compound is an electron transport material. The first substance is a metal, a metal salt, It is a metal oxide or organometallic salt. The electron transport layer consists of a first region and a second region. It possesses. The first region and the second region have different concentrations of the first substance.

[0009] When the first region is located closer to the first light-emitting layer than the second region, the first region is... It is preferable that the concentration of the first substance is higher compared to the surrounding area.

[0010] The second light-emitting device has a common layer between the second electrode and the common electrode, which is the same as that of the first light-emitting device. It is preferable that it has

[0011] The third organic compound has a HOMO level of -6.0 eV or higher and an electric field strength of [V / cm²]. The electron mobility at which the square root of ] is 600 is 1 × 10 -7 cm 2 / Vs or more 5×10 -5 c m 2 It is preferable that it is less than or equal to / Vs.

[0012] The second light-emitting layer preferably further comprises a fourth organic compound and a fifth organic compound. i. The fourth and fifth organic compounds are a combination that forms an excited complex. It is preferable.

[0013] The first light-emitting device preferably further has a hole injection layer. The hole injection layer is It is preferable that the electrode functioning as the anode among the electrode 1 and the common electrode be in contact with the hole injection. The layer preferably has a first compound and a second compound. The first compound is the second It is preferable that the compound has electron-accepting properties. The HOMO level of the second compound is - It is preferable that the voltage is between 5.7 eV and -5.4 eV.

[0014] The first light-emitting device preferably further has a first hole transport layer. The transport layer is preferably located between the hole injection layer and the first light-emitting layer. The layer preferably contains a third compound. The HOMO level of the third compound is the same as that of the second compound. It is preferable that the value is below the HOMO level of the compound. The difference between the HOMO level of the compound is preferably within 0.2 eV. Second compound The first and third compounds are, respectively, a carbazole skeleton, a dibenzofuran skeleton, and a dibenzothio It is preferable that the material has at least one of the following: a fen skeleton and an anthracene skeleton.

[0015] The first light-emitting device preferably further has a second hole transport layer. The transport layer is preferably located between the first hole transport layer and the first light-emitting layer. The pore transport layer preferably contains a fourth compound. The HOMO level of the fourth compound is It is preferable that the HOMO level of the second compound, the third compound, and The fourth compound consists of a carbazole skeleton, a dibenzofuran skeleton, and a dibenzothiofune, respectively. It is preferable that the material has at least one of the following: a cene skeleton and an anthracene skeleton.

[0016] The first organic compound is preferably a fluorescent substance.

[0017] The first color is preferably blue. The second color is preferably red or green. It's nice.

[0018] The first substance is an organometallic complex containing an alkali metal or alkaline earth metal. It is preferable.

[0019] The first substance comprises a ligand having nitrogen and oxygen, and an alkali metal or alkaline earth metal. It is preferable that the organometallic complex has the following properties.

[0020] The first substance comprises a quinolinol ligand and an alkali metal or alkaline earth metal. It is preferable that it be an organometallic complex.

[0021] One aspect of the present invention has a display device having any of the above configurations, and a flexible printed circuit board A board (Flexible Printed Circuit, hereinafter referred to as FPC) or This is equipped with connectors such as TCP (Tape Carrier Package). Display module, or COG (Chip On Glass) method or COF (C Display modules etc. with integrated circuits (ICs) mounted using methods such as hip-on-film. This is the display module.

[0022] One aspect of the present invention includes the above-mentioned display module, an antenna, a battery, a housing, a camera, and a speaker. An electronic device having at least one of a microphone, a microphone, and an operating button. [Effects of the Invention]

[0023] According to one aspect of the present invention, a long-life display device can be provided. According to one aspect of the present invention, reliability A high-performance display device can be provided. According to one aspect of the present invention, a large-scale display device can be provided. According to one aspect of the invention, a highly productive display device can be provided. According to one aspect of the invention, display We can provide high-quality display devices.

[0024] Furthermore, the description of these effects does not preclude the existence of other effects. One aspect of the present invention is It is not necessarily required to have all of these effects. It is possible to extract effects other than those mentioned above. [Brief explanation of the drawing]

[0025] [Figure 1] Figures 1A and 1B are cross-sectional views showing an example of a display device. [Figure 2] Figures 2A and 2B are cross-sectional views showing an example of a display device. [Figure 3] Figure 3 is a cross-sectional view showing an example of a display device. [Figure 4] Figures 4A to 4C are cross-sectional views showing an example of a light-emitting device. [Figure 5] Figures 5A to 5C are conceptual diagrams illustrating the light emission model of a light-emitting device. Figure 5D is a diagram illustrating the normalized brightness of a light-emitting device over time. [Figure 6] Figures 6A to 6D illustrate the concentration of the first substance in the electron transport layer. [Figure 7] Figure 7 is a perspective view showing an example of a display device. [Figure 8] Figures 8A and 8B are cross-sectional views showing an example of a display device. [Figure 9] Figure 9A is a cross-sectional view showing an example of a display device. Figure 9B is a cross-sectional view showing an example of a transistor. [Figure 10] Figure 10A is a block diagram showing an example of a pixel. Figure 10B is a circuit diagram showing an example of a pixel circuit. [Figure 11]Figure 11A illustrates the classification of IGZO crystal structures. Figure 11B illustrates the XRD spectrum of a quartz glass substrate. Figure 11C illustrates the XRD spectrum of a crystalline IGZO film. Figure 11D illustrates the micro-electron diffraction pattern of a quartz glass substrate. Figure 11E illustrates the micro-electron diffraction pattern of a crystalline IGZO film. [Figure 12] Figures 12A and 12B show examples of electronic devices. [Figure 13] Figures 13A to 13C show examples of electronic devices. [Figure 14] Figures 14A and 14B show examples of electronic devices. [Figure 15] Figures 15A to 15D show examples of electronic devices. [Figure 16] Figures 16A to 16D show examples of electronic devices. [Figure 17] Figures 17A to 17F show examples of electronic devices. [Figure 18] Figure 18A shows the structure of an electron-only device. Figure 18B shows the structure of an example light-emitting device. [Figure 19] Figure 19 shows the current density-voltage characteristics of an electron-only device. [Figure 20] Figure 20 shows the frequency characteristics of the calculated capacitance C in the ZADN:Liq(1:1) ratio at a DC power supply of 7.0V. [Figure 21] Figure 21 shows the frequency characteristics of -ΔB for ZADN:Liq(1:1) at a DC voltage of 7.0V. [Figure 22] Figure 22 shows the electric field strength dependence characteristics of electron mobility in each organic compound. [Figure 23] Figure 23 shows the luminance-current density characteristics. [Figure 24] Figure 24 shows the luminance-voltage characteristics. [Figure 25] Figure 25 shows the current efficiency-luminance characteristics. [Figure 26]Figure 26 shows the current density-voltage characteristics. [Figure 27] Figure 27 shows the emission spectrum. [Figure 28] Figure 28 shows the luminance-current density characteristics. [Figure 29] Figure 29 shows the luminance-voltage characteristics. [Figure 30] Figure 30 shows the current efficiency-luminance characteristics. [Figure 31] Figure 31 shows the current density-voltage characteristics. [Figure 32] Figure 32 shows the emission spectrum. [Figure 33] Figure 33 shows the luminance-current density characteristics. [Figure 34] Figure 34 shows the luminance-voltage characteristics. [Figure 35] Figure 35 shows the current efficiency-luminance characteristics. [Figure 36] Figure 36 shows the current density-voltage characteristics. [Figure 37] Figure 37 shows the emission spectrum. [Figure 38] Figure 38 shows the results of the reliability test. [Figure 39] Figure 39 shows the results of the reliability test. [Figure 40] Figure 40 shows the results of the reliability test. [Figure 41] Figure 41 shows the results of the reliability test. [Modes for carrying out the invention]

[0026] Embodiments will be described in detail with reference to the drawings. However, the present invention is not limited to the following description. Without departing from the spirit and scope of the present invention, its form and details may be modified in various ways. It will be easily understood by those skilled in the art to obtain this. Therefore, the present invention is as shown in the embodiments below. The interpretation is not limited to the content stated herein.

[0027] In the configuration of the invention described below, the same part or part having a similar function is used. The same symbol is used consistently across different drawings, and explanations of its repetition are omitted. When referring to a function, the same hatch pattern may be used, and a specific symbol may not be assigned.

[0028] Furthermore, the position, size, and extent of each component shown in the drawings are, for the sake of ease of understanding, actually The location, size, and range may not be described. Therefore, the disclosed invention is not always Furthermore, it is not limited to the location, size, scope, etc., disclosed in the drawings.

[0029] Furthermore, the words "membrane" and "layer" may differ depending on the context or situation. And they can be interchanged. For example, the term "conductive layer" can be replaced with "conductive film." It is possible to change the term to this. Or, for example, the term "insulating film" can be changed to It is possible to change the term to "insulating layer".

[0030] In this specification, unless otherwise specified, elements (light-emitting devices, light-emitting layers, etc.) are defined as follows: Even when describing a configuration with multiple elements, when describing matters common to each element The letters are omitted in the explanation. For example, light-emitting layer 193R and light-emitting layer 193G, etc. When explaining common features, the term "emissive layer 193" may be used.

[0031] (Embodiment 1) In this embodiment, a display device according to one aspect of the present invention will be described with reference to Figures 1 to 9.

[0032] The display device of this embodiment has a light-emitting device in the display unit, and displays an image in the display unit. It is possible.

[0033] As for light-emitting devices, OLED (Organic Light Emitting Diode) iode) and QLED(Quantum-dot Light Emitting Di) It is preferable to use an EL device such as an ode. The light-emitting material of the EL device and Examples include fluorescent substances, phosphorescent substances, and inorganic substances. Compounds (such as quantum dot materials), substances that exhibit thermally activated delayed fluorescence (thermally activated delayed fluorescence (Th ermally Activated Delayed Fluorescence:T Examples include ADF (materials) and others.

[0034] The colorization method for the display device in this embodiment is a color-shading method. When using a color-coding method for the display device, the alignment accuracy of the metal mask can be improved. This is preferable because it can improve the yield of the paint separation process. Also, large display devices have a high degree of detail. Because it can be made relatively low, it is advantageous in that it employs a paint-coloring method for light-emitting devices. .

[0035] Each subpixel of each color has a different light-emitting layer. It is preferable that the light-emitting layers are separated from each other. In addition, the light-emitting layers of each light-emitting device may have overlapping portions.

[0036] The display device of this embodiment emits light in the direction opposite to the substrate on which the light-emitting device is formed. A top-emission type, where light is emitted towards the substrate side on which the light-emitting device is formed. It may be either an emission type or a dual-emission type that emits light from both sides.

[0037] It is preferable to employ a microcavity structure for the light-emitting device. Specifically, in order to adjust the optical distance between a pair of electrodes, in the EL layer, in addition to the light-emitting layer, Then, another layer (for example, a hole transport layer) is painted with light-emitting devices of each color, and the other layers are... It is preferable to have a common layer for each color of light-emitting device. This simplifies the process and Furthermore, it is possible to efficiently extract light and realize a display device capable of displaying a wide color gamut.

[0038] The display device of this embodiment is such that holes are easily injected into the light-emitting layer, and electrons are not easily injected. It has a light-emitting device with a configuration in which holes are easily injected from the anode side and light is emitted from the cathode side. By suppressing the amount of electrons injected into the photolayer, it is possible to prevent the light-emitting layer from becoming electron-excessive. And as time passes, electrons are injected into the light-emitting layer, causing the brightness to increase. This increase in brightness can offset the initial degradation. Initial degradation is suppressed, and the operating life is extended. By using extremely long-lasting light-emitting devices, the lifespan of display devices is extended and their reliability is increased. This is possible. The configuration of the light-emitting device will be described later with reference to Figures 4 to 6.

[0039] First, Figures 1 to 3 show examples of display device configurations. The display devices shown in Figures 1 to 3 include at least Another light-emitting device uses the configuration of a light-emitting device illustrated in Figures 4 to 6.

[0040] [Display device 10A] Figure 1A shows a cross-sectional view of the display device 10A.

[0041] The display device 10A emits a light-emitting device 190R that emits red light 21R and a light-emitting device 21G that emits green light. It has a light-emitting device 190G that emits blue light 21B and a light-emitting device 190B that emits blue light 21B. .

[0042] The light-emitting device 190R includes a pixel electrode 191, an optical adjustment layer 199R, a buffer layer 192R, It has a light-emitting layer 193R, a buffer layer 194R, and a common electrode 115. The light-emitting layer 193R is It contains an organic compound that emits red light.

[0043] The light-emitting device 190G consists of a pixel electrode 191, an optical adjustment layer 199G, a buffer layer 192G, It has a light-emitting layer 193G, a buffer layer 194G, and a common electrode 115. The light-emitting layer 193G is It contains organic compounds that emit green light.

[0044] The light-emitting device 190B includes a pixel electrode 191, an optical adjustment layer 199B, a buffer layer 192B, It has a light-emitting layer 193B, a buffer layer 194B, and a common electrode 115. The light-emitting layer 193B is It contains organic compounds that emit blue light.

[0045] In this specification, an organic compound that emits blue light is referred to as the first organic compound, and red light is also referred to as the first organic compound. Organic compounds that emit colored light or green light are referred to as the second organic compound. Sometimes.

[0046] Of the light-emitting devices 190R, 190G, and 190B, at least One example is the configuration of the light-emitting device illustrated in Figures 4 to 6.

[0047] In this embodiment, the pixel electrode 191 functions as the anode, and the common electrode 115 functions as the cathode. Let's explain using an example of a case where it is possible.

[0048] Pixel electrode 191, optical adjustment layer 199R, optical adjustment layer 199G, optical adjustment layer 199B, Layer 192R, Buffer layer 192G, Buffer layer 192B, Light-emitting layer 193R, Light-emitting layer 1 93G, Emitting layer 193B, Buffer layer 194R, Buffer layer 194G, Buffer layer 194 B and the common electrode 115 may each have a single-layer structure or a multi-layer structure. stomach.

[0049] The pixel electrode 191 is located on the insulating layer 214. The end of the pixel electrode 191 is on the partition wall 216. Therefore, it is covered. Each pixel electrode 191 is electrically insulated from each other by a partition wall 216. They are (or are electrically isolated).

[0050] An organic insulating film is preferred as the partition wall 216. For example, acrylic resin, polyimide resin, epoxy resin, polyamide resin, polyimide Mido resins, siloxane resins, benzocyclobutene resins, phenolic resins, and these resins Examples include lipid precursors.

[0051] The buffer layer 192 is located on the pixel electrode 191. The light-emitting layer 193 is located on the buffer layer 192 It overlaps with the pixel electrode 191 via this. The buffer layer 194 is located on the light-emitting layer 193. The light-emitting layer 193 overlaps with the common electrode 115 via the buffer layer 194. Buffer layer 19 Layer 2 may have one or both of a hole injection layer and a hole transport layer. Buffer layer 1 94 may have one or both of the electron injection layer and the electron transport layer.

[0052] The common electrode 115 is a layer used in common by each color of light-emitting device 190.

[0053] The display device 10A has a light-emitting device 190 between a pair of substrates (substrate 151 and substrate 152). It also has transistors 42, etc.

[0054] In the light-emitting device 190, the following are located between the pixel electrode 191 and the common electrode 115, respectively. The buffer layer 192, the light-emitting layer 193, and the buffer layer 194 can also be called an EL layer. The pixel electrode 191 preferably has the function of reflecting visible light. The common electrode 115 is It has the function of transmitting visible light.

[0055] A microcavity structure is applied to the light-emitting device of the display device in this embodiment. It is preferable that one of the pair of electrodes of the light-emitting device is reflective to visible light. It is preferable to have electrodes that have permeability and reflectivity (semi-permeable / semi-reflective electrodes), and other The method preferably has an electrode (reflective electrode) that is reflective to visible light. The vice has a microcavity structure, which allows the light emitted from the light-emitting layer to be transmitted between the two electrodes. By causing resonance, the light emitted from the light-emitting device can be intensified.

[0056] Furthermore, semi-transmissive / semi-reflective electrodes are electrodes that transmit visible light (transparent electrodes) and reflective electrodes. It can be made into a laminated structure of (also called) semi-transparent and semi-reflective. In this specification, they are referred to as semi-transparent and semi-reflective, respectively. Reflective electrodes that function as part of the radiating electrodes are referred to as pixel electrodes or common electrodes, and transparent electrodes are referred to as light electrodes. Although sometimes referred to as the optical adjustment layer, the transparent electrode (optical adjustment layer) is also called the pixel electrode or common electrode. It can be said that it has the function of [that].

[0057] The light transmittance of the transparent electrode shall be 40% or more. For example, the light-emitting device shall emit visible light (wavelength Light between 400nm and less than 750nm and near-infrared light (wavelength between 750nm and 1300nm) It is preferable to use electrodes in which the transmittance of each of the following types of light is 40% or more. The reflectance of the transmitted and semi-transmitted electrodes for visible light and near-infrared light, respectively, should be between 10% and 95%. The reflectance shall be between 30% and 80%. The reflectance of the reflective electrode for visible and near-infrared light shall be 40 The percentage should be between % and 100%, preferably between 70% and 100%. The resistivity is 1 × 10⁻⁶ -2 A value of Ωcm or less is preferable.

[0058] In this embodiment, an example is shown in which an optical adjustment layer 199 is provided on the pixel electrode 191, but optical adjustment Layer 199 does not need to be provided. For example, buffer layer 192 or buffer layer 194 is optical It may also function as a coordinating layer. Buffer layer 192 or buffer layer 194 By varying the film thickness, it is possible to intensify and extract light of a specific color in each light-emitting device. This is possible. Furthermore, if the semi-transparent / semi-reflective electrode has a laminated structure of a reflective electrode and a transparent electrode, one pair The optical distance between electrodes refers to the optical distance between a pair of reflective electrodes.

[0059] The light-emitting device 190 has the function of emitting visible light. Specifically, the light-emitting device 190 This is achieved by applying a voltage between the pixel electrode 191 and the common electrode 115, thereby allowing light to be emitted towards the substrate 152. It is an electroluminescent device that emits light.

[0060] The pixel electrode 191 is connected to the transistor 42 through an opening provided in the insulating layer 214. It is electrically connected to the source or drain. Transistor 42 is connected to the light-emitting device 190 It has a function to control the drive.

[0061] Each light-emitting device 190 is preferably covered with a protective layer 195. Figure 1A The protective layer 195 is provided in contact with the common electrode 115. This prevents impurities such as water from entering the light-emitting device 190, and the light-emitting device The reliability of 190 can be increased. Also, the adhesive layer 142 connects the protective layer 195 and the base Board 152 is glued to it.

[0062] As the light-shielding layer BM, a material that blocks light emission from the light-emitting device can be used. BM preferably absorbs visible light. As the light-shielding layer BM, for example, a metal material, Using resin materials containing pigments (such as carbon black) or dyes, black matri It can form a shading layer BM, a red color filter, a green color filter It may also be a stacked structure of a ruta and a blue color filter.

[0063] The light-emitting layer 193R preferably contains a phosphorescent material as an organic compound that emits red light. It seems so. The light-emitting layer 193G has a phosphorescent material as an organic compound that emits green light. This is preferable. Also, the light-emitting device 190R has a pixel electrode 191 and a common electrode 115. It is preferable that an excitation complex is formed in the light-emitting layer 193R by applying a voltage between them. As described above, the light-emitting device 190G applies a voltage between the pixel electrode 191 and the common electrode 115. It is preferable that an excitation complex is formed in the light-emitting layer 193G. This increases the luminous efficiency of light-emitting device 190R and light-emitting device 190G, respectively. It is possible.

[0064] For example, the light-emitting layer 193R and the light-emitting layer 193G each contain two types of luminescent material in addition to the light-emitting material. It is preferable that the mixture contains organic compounds. The two organic compounds are substances that form an excited complex. This is preferable. It can also be said that the two organic compounds are a combination that forms an excited complex. In the light-emitting layer 193R and the light-emitting layer 193G, the two organic compounds are phosphates. These can also be called host material and assist material, or first host material and second host material. Yes, it is possible. Alternatively, the host material of each of the light-emitting layers 193R and 193G is It can also be described as a mixed material of two types of organic compounds. The two types of organic compounds present in the light-emitting layer 193R Each of the organic compounds is made of the same material as each of the two organic compounds present in the light-emitting layer 193G. It may be a single ingredient, or it may be made from different materials.

[0065] Furthermore, in this specification, the two organic compounds are referred to as the fourth organic compound and the fifth organic compound. This is sometimes written. The configuration of the luminescent layer that can form an excitation complex will be described later. .

[0066] The light-emitting layer 193B preferably contains a fluorescent material as an organic compound that emits blue light. It seems so.

[0067] [Display device 10B] Figure 1B shows a cross-sectional view of the display device 10B. Note that in the following description of the display device, the previous explanation will be explained. For configurations similar to those of the display device described, explanations may be omitted.

[0068] The display device 10B includes a red light-emitting device 190R and a green light-emitting device 190G, It differs from the display device 10A in that it has a through layer 182 and a common layer 184.

[0069] Red light-emitting device 190R, green light-emitting device 190G, and blue light-emitting device 1 At least two of the 90B light-emitting devices have one or more layers used in common (common layer). It is preferable to have the above. This allows the display device to be manufactured with fewer manufacturing steps.

[0070] In Figure 1B, light-emitting devices 190R and 190G are connected to common layer 182 and common layer An example having 184 is shown, but one aspect of the present invention is a display device which includes a light-emitting device 190R and The optical device 190G has a configuration that includes only a common layer 182 or only a common layer 184. That's fine.

[0071] The common layer 182 is located between the pixel electrode 191 and the light-emitting layer 193R, and between the pixel electrode 191 and the light-emitting layer It is located between 193G and 193G.

[0072] The common layer 184 is located between the light-emitting layer 193R and the common electrode 115, and between the light-emitting layer 193G and the common electrode It is located between the extreme 115.

[0073] Common layer 182 and common layer 184 may each be a single-layer structure or a laminated structure. That's fine.

[0074] The common layer 182 can, for example, form one or both of the hole injection layer and the hole transport layer. It is possible.

[0075] The common layer 184 can, for example, form one or both of the electron injection layer and the electron transport layer. It is possible.

[0076] Furthermore, the light-emitting devices 190R and 190G are connected to the pixel electrode 191 and the common layer 18 Between 2, between common layer 182 and light-emitting layer, between light-emitting layer and common layer 184, and common layer 1 A buffer layer may be provided at least at one location between 84 and the common electrode 115. Examples of buffer layers include hole injection layers, hole transport layers, electron transport layers, and electron injection layers. At least one of these can be formed.

[0077] For example, the configuration of the light-emitting device illustrated in Figures 4 to 6 is applied to the light-emitting device 190B. It is preferable that both light-emitting device 190R and light-emitting device 190G are present. The configuration of the light-emitting device illustrated in Figures 4 to 6 may be applied.

[0078] Furthermore, one of the light-emitting devices 190R or 190G and light-emitting device 190 When applying the configuration of the light-emitting device exemplified in Figures 4 to 6 to B and , the light-emitting device One of the light-emitting devices, either S190R or 190G, and light-emitting device 190B, are in the common layer 1 It is preferable that it has 82 and a common layer 184. In this case, common layer 182 and common layer The configuration of 184 is preferably one that uses the light-emitting device configuration illustrated in Figures 4 to 6. It's nice.

[0079] [Display device 10C] Figure 2A shows a cross-sectional view of the display device 10C.

[0080] The display device 10C includes a red light-emitting device 190R, a green light-emitting device 190G, and a blue light-emitting device. The display device 10 has a common layer 112 and a common layer 114 in which the color light-emitting device 190B is located. It is different from A.

[0081] Red light-emitting device 190R, green light-emitting device 190G, and blue light-emitting device 1 90B preferably has one or more layers that are used in common (common layers). This allows for the manufacture of display devices with fewer manufacturing steps.

[0082] Figure 2A shows an example where each color light-emitting device has a common layer 112 and a common layer 114, A display device according to one aspect of the present invention is such that each color light-emitting device is only on the common layer 112, or the common layer The configuration may also have only 114.

[0083] The common layer 112 is located between the pixel electrode 191 and the light-emitting layers of each color.

[0084] The common layer 114 is located between the light-emitting layers of each color and the common electrode 115.

[0085] Common layers 112 and 114 may each be single-layer structures or laminated structures. That's fine.

[0086] The common layer 112 can, for example, form one or both of the hole injection layer and the hole transport layer. It is possible.

[0087] The common layer 114 can, for example, form one or both of the electron injection layer and the electron transport layer. It is possible.

[0088] Each light-emitting device is located between the pixel electrode 191 and the common layer 112, and between the common layer 112 and the light-emitting layer. Between the light-emitting layer and the common layer 114, and between the common layer 114 and the common electrode 115 It may have a buffer layer in at least one place. The buffer layer may be, for example, Forming at least one of a hole injection layer, a hole transport layer, an electron transport layer, and an electron injection layer. It is possible.

[0089] [Display device 10D] Figure 2B shows a cross-sectional view of the display device 10D.

[0090] The display device 10D does not have substrates 151 and 152, but has substrates 153, 154, and adhesive It differs from the display device 10C in that it has layer 155 and an insulating layer 212.

[0091] The substrate 153 and the insulating layer 212 are bonded together by the adhesive layer 155. The protective layer 195 is bonded to the adhesive layer 142.

[0092] The display device 10D includes an insulating layer 212 formed on the fabricated substrate, a transistor 42, and each color This configuration is manufactured by transferring the light-emitting device, etc., onto the substrate 153. The substrate 154 is preferably flexible. The flexibility of 0D can be increased. For example, substrates 153 and 154 are, It is preferable to use a resin.

[0093] The substrates 153 and 154 are made of polyethylene terephthalate (PET), respectively. Polyester resins such as polyethylene naphthalate (PEN), polyacrylonitrile resin Fat, acrylic resin, polyimide resin, polymethyl methacrylate resin, polycarbonate (PC) resin, polyethersulfone (PES) resin, polyamide resin (nylon, ara Polyamides, polysiloxane resins, cycloolefin resins, polystyrene resins, polyamides Imide resin, polyurethane resin, polyvinyl chloride resin, polyvinylidene chloride resin, polyp Polypropylene resin, polytetrafluoroethylene (PTFE) resin, ABS resin, cellulose Nanofibers and the like can be used. On one or both of substrates 153 and 154 Alternatively, glass of a thickness sufficient to be flexible may be used.

[0094] The substrate of the display device in this embodiment may be a film with high optical isotropy. Examples of films with high optical isotropy include triacetylcellulose (TAC, cellulose tri Acetate film, cycloolefin polymer (COP) film, cyclo Examples include olefin copolymer (COC) films and acrylic films.

[0095] [Display device 10E] Figure 3 shows a cross-sectional view of the display device 10E.

[0096] Display device 10E differs from display device 10C in that it is a bottom-emission type.

[0097] The pixel electrode 191 has the function of transmitting visible light. The common electrode 115 reflects visible light. It is preferable that it has a function.

[0098] The transistor 42 is positioned so as not to overlap with the light-emitting region of the light-emitting device. preferable.

[0099] In the display device 10E, the substrate 152 is provided on the protective layer 195 via an adhesive layer 142. An example is shown, but the adhesive layer 142 and the substrate 152 do not need to be provided.

[0100] [Light-emitting devices] Figures 4A to 4C show an example of a light-emitting device that can be used in the display device of this embodiment. show.

[0101] The light-emitting device shown in Figure 4A has an anode 101, an EL layer 103, and a cathode 102. The L layer 103 consists of a hole injection layer 121, a hole transport layer 122, and a light-emitting layer 123, starting from the anode 101 side. It has an electron transport layer 124 and an electron injection layer 125. Note that it is not shown in Figures 4A to 4C. However, the light-emitting device may have an optical adjustment layer.

[0102] Anode 101, cathode 102, hole injection layer 121, hole transport layer 122, light-emitting layer 123, electron transport The electron injection layer 124 and the electron injection layer 125 can each be a single layer or a stacked layer. That's fine.

[0103] The hole transport layer 122 in the light-emitting device shown in Figures 4B and 4C is on the hole injection layer 121 side. It has a two-layer structure consisting of a hole transport layer 122a on the front and a hole transport layer 122b on the light-emitting layer 123 side. .

[0104] The electron transport layer 124 of the light-emitting device shown in Figure 4C is the electron transport layer 1 on the light-emitting layer 123 side. It has a two-layer structure consisting of 24a and the electron transport layer 124b on the electron injection layer 125 side.

[0105] The following section describes materials that can be used in light-emitting devices.

[0106] <Electrode> Materials used to form a pair of electrodes in a light-emitting device include metals, alloys, electrically conductive compounds, and These mixtures can be used as appropriate. Specifically, In-Sn oxide (IT Also known as O), In-Si-Sn oxide (also known as ITSO), In-Zn oxide, In -W-Zn oxide is one example. Other examples include aluminum (Al), titanium (Ti), and chromium oxide. Cr (Magnesium), Manganese (Mn), Iron (Fe), Cobalt (Co), Nickel (Ni), Copper (Cu), gallium (Ga), zinc (Zn), indium (In), tin (Sn), molybdenum Butene (Mo), Tantalum (Ta), Tungsten (W), Palladium (Pd), Gold (A) metals such as u), platinum (Pt), silver (Ag), yttrium (Y), neodymium (Nd), And alloys containing these in appropriate combinations can also be used. Other examples not listed above include... Elements belonging to Group 1 or Group 2 of the periodic table (for example, lithium (Li), cesium ( Cs), calcium (Ca), strontium (Sr), europium (Eu), i Rare earth metals such as terbium (Yb) and alloys containing them in appropriate combinations, graphite You can use things like n.

[0107] Furthermore, when fabricating light-emitting devices with a microcavity structure, reflective electrodes and semipermeable electrodes are used. Hyper- and semi-reflective electrodes are used. Therefore, one or more desired conductive materials are used, and a single layer or These can be formed by stacking. Sputtering and vacuum deposition methods are used to fabricate the electrodes. It is possible to be there.

[0108] <Hole injection layer> The hole injection layer 121 preferably contains a first compound and a second compound.

[0109] The first compound is an electron-accepting material, and is related to the second compound. It has electron-accepting properties.

[0110] The second compound is a hole-transporting material. Hole-transporting materials are materials that are more efficient at transporting holes than electrons. expensive.

[0111] The second compound is preferably given a relatively low (deep) highest occupied orbital level (HOMO level). Specifically, the HOMO level of the second compound is between -5.7 eV and -5.4 eV. It is preferable that the HOMO level of the second compound is relatively low, which is beneficial for the hole transport layer 12 This facilitates the injection of holes into 2, which is preferable.

[0112] The first compound is an electron-withdrawing group (especially halogen groups such as fluoro groups or cyano groups). Organic compounds containing these compounds can be used.

[0113] Examples of the first compound include quinodimethane derivatives, chloranil derivatives, and hexaazato. Organic acceptors such as riphenylene derivatives can be used. Specifically, 7,7 ,8,8-tetracyano-2,3,5,6-tetrafluoroquinodimethane (abbreviation: F4- TCNQ), chloranil, 2,3,6,7,10,11-hexacyano-1,4,5,8 ,9,12-Hexaazatriphenylene (abbreviation: HAT-CN), 1,3,4,5,7, 8-Hexafluorotetracyano-naphthoquinodimethane (abbreviation: F6-TCNNQ), 2 -(7-dicyanomethylene-1,3,4,5,6,8,9,10-octafluoro-7H Examples include (-pyrene-2-ylidene)malononitrile, etc. In particular, HAT-CN Compounds in which an electron-withdrawing group is bonded to a condensed aromatic ring having multiple complex atoms, such as the one shown, are thermally It is stable and desirable. Also, electron-withdrawing groups (especially halogen groups such as fluoro groups and cyano groups) Radialene derivatives having [3] are preferred because they have very high electron-accepting properties. Examples of radialene derivatives having the group [3] include α,α',α''-1,2,3- Cyclopropane triylidenates[4-cyano-2,3,5,6-tetrafluorobene] Zenacetonitrile, α,α',α''-1,2,3-cyclopropane triirident RIS[2,6-dichloro-3,5-difluoro-4-(trifluoromethyl)benzene Cetonitrile, α,α',α''-1,2,3-cyclopropanetriylidenes[ Examples include 2,3,4,5,6-pentafluorobenzeneacetonitrile.

[0114] The second compound preferably has a hole-transporting skeleton. The HOMO level of the hole transport material does not become too high (shallow), carbazole skeleton, gibberellin An lenzofuran skeleton, a dibenzothiophene skeleton, and an anthracene skeleton are preferred.

[0115] The second compound has a carbazole skeleton, a dibenzofuran skeleton, a dibenzothiophene skeleton, and It is preferable to have at least one of the anthracene skeleton. The hole transport material is Aromatic amines having substituents including a dibenzofuran ring or a dibenzothiophene ring, naphth Aromatic monoamines having a talene ring, or a 9-fluorenyl group via an arylene group The amine may also be an aromatic monoamine bonded to the nitrogen atom.

[0116] If the second compound has an N,N-bis(4-biphenyl)amino group, a long-lived luminescence This is preferable because it allows for the creation of a vise.

[0117] A second compound is, for example, 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]Fran-8-yl-4''-phenyltriphenylamine (abbreviation: BnfBB1BP) ), N,N-bis(4-biphenyl)benzo[b]naphtho[1,2-d]furan-6-a Min (abbreviation: BBABnf(6)), N,N-bis(4-biphenyl)benzo[b]naph To[1,2-d]furan-8-amine (abbreviation: BBABnf(8)), N,N-bis(4 -Biphenyl)benzo[b]naphtho[2,3-d]furan-4-amine (abbreviation: BBAB) nf(II)(4)), N,N-bis[4-(dibenzofuran-4-yl)phenyl]- 4-amino-p-terphenyl (abbreviation: DBfBB1TP), N-[4-(dibenzothio Fen-4-yl)phenyl]-N-phenyl-4-biphenylamine (abbreviation: ThBA) 1BP), 4-(2-naphthyl)-4',4''-diphenyltriphenylamine (abbreviation) :BBAβNB), 4-[4-(2-naphthyl)phenyl]-4',4''-diphenyl Triphenylamine (abbreviation: BBAβNBi), 4,4'-diphenyl-4''-(6; 1'-Binaphthyl-2-yl)triphenylamine (abbreviation: BBAαNβNB), 4,4 '-diphenyl-4''-(7;1'-binaphthyl-2-yl)triphenylamine (abbreviated) Name: BBAαNβNB-03), 4,4'-diphenyl-4''-(7-phenyl)naph Tyl-2-yltriphenylamine (abbreviation: BBAPβNB-03), 4,4'-diphenylamine Nyl-4''-(6;2'-binaphthyl-2-yl)triphenylamine (abbreviation: BBA) (βN2)B), 4,4'-diphenyl-4''-(7;2'-binaphthyl-2-yl) Triphenylamine (abbreviation: BBA(βN2)B-03), 4,4'-diphenyl-4' '-(4;2'-binaphthyl-1-yl)triphenylamine (abbreviation: BBAβNαNB) ), 4,4'-diphenyl-4''-(5;2'-binaphthyl-1-yl)triphenyl Amine (abbreviation: BBAβNαNB-02), 4-(4-biphenylyl)-4'-(2-na Phthyl)-4''-phenyltriphenylamine (abbreviation: TPBiAβNB), 4-(3 -biphenylyl)-4'-[4-(2-naphthyl)phenyl]-4''-phenyltri enylamine (abbreviation: mTPBiAβNBi), 4-(4-biphenylyl)-4'-[4 -(2-naphthyl)phenyl]-4''-phenyltriphenylamine (abbreviation: TPBi AβNBi), 4-phenyl-4'-(1-naphthyl)triphenylamine (abbreviation: αN BA1BP), 4,4'-bis(1-naphthyl)triphenylamine (abbreviation: αNBB1 BP), 4,4'-diphenyl-4''-[4'-(carbazol-9-yl)bipheny l-4-yl]triphenylamine (abbreviation: YGTBi1BP), 4'-[4-(3-ph enyl-9H-carbazol-9-yl)phenyl]tris(1,1'-biphenyl-4 -yl)amine (abbreviation: YGTBi1BP-02), 4-[4'-(carbazol-9- yl)biphenyl-4-yl]-4'-(2-naphthyl)-4''-phenyltripheny lamine (abbreviation: YGTBiβNB), N-[4-(9-phenyl-9H-carbazole -3-yl)phenyl]-N-[4-(1-naphthyl)phenyl]-9,9'-spirobi (9H-fluorene)-2-amine (abbreviation: PCBNBSF), N,N-bis([1,1 '-biphenyl]-4-yl)-9,9'-spirobi[9H-fluorene]-2-amine (abbreviation: BBASF), N,N-bis([1,1'-biphenyl]-4-yl)-9,9 '-spirobi[9H-fluorene]-4-amine (abbreviation: BBASF(4)), N-(1 ,1'-biphenyl-2-yl)-N-(9,9-dimethyl-9H-fluoren-2-yl )-9,9'-spirobi(9H-fluorene)-4-amine (abbreviation: oFBiSF), N-(4-biphenyl)-N-(9,9-dimethyl-9H-fluoren-2-yl)dibe nzofuran-4-amine (abbreviation: FrBiF), N-[4-(1-naphthyl)phenyl -N-[3-(6-phenyldibenzofuran-4-yl)phenyl]-1-naphthylamin e (abbreviation: mPDBfBNBN), 4-phenyl-4'-(9-phenylfluoren-9 -yl)triphenylamine (abbreviation: BPAFLP), 4-phenyl-3'-(9-phen ylfluoren-9-yl)triphenylamine (abbreviation: mBPAFLP), 4-pheny l-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-carbazol-3-yl)triphenylamine (abbreviation: P CBBi1BP), 4-(1-naphthyl)-4'-(9-phenyl-9H-carbazole -3-yl)triphenylamine (abbreviation: PCBANB), 4,4'-di(1-naphthyl )-4''-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbre viation: PCBNBB), N-phenyl-N-[4-(9-phenyl-9H-carbazole- 3-yl)phenyl]spiro-9,9'-bifluoren-2-amine (abbreviation: PCBAS F), N-(1,1'-biphenyl-4-yl)-9,9-dimethyl-N-[4-(9- phenyl-9H-carbazol-3-yl)phenyl]-9H-fluoren-2-amine (abbreviation: PCBBiF), 3,3'-(naphthalene-1,4-diyl)bis(9-pheny l-9H-carbazole) (abbreviation: PCzN2), 4-(10-phenyl-9-anthryl (Lu)-4'-(9-phenyl-9H-fluoren-9-yl)triphenylamine (abbreviation) Examples include :FLPAPA).

[0118] <Hole transport layer> The hole transport layer 122 transports the holes injected by the hole injection layer 121 to the light-emitting layer 123. It is a layer.

[0119] The hole transport layer 122 preferably contains a third compound.

[0120] The third compound is a hole-transporting material. As a hole-transporting material, it is used in the second compound. A hole-transporting material that can transport holes can be used.

[0121] The HOMO level of the third compound is preferably less than or equal to the HOMO level of the second compound. The difference between the HOMO level of the third compound and the HOMO level of the second compound is 0.2 eV. It is preferable that it be within a certain range.

[0122] The second and third compounds each consist of a carbazole skeleton and a dibenzofuran skeleton, respectively. It is preferable that it has at least one of the dibenzothiophene skeleton and the anthracene skeleton. It seems so.

[0123] The second and third compounds share the same hole-transporting skeleton (particularly the dibenzofuran skeleton). This is preferable because it allows for smoother hole injection.

[0124] It is preferable that the second and third compounds are the same, as this allows for smoother hole injection. It seems so.

[0125] If the hole transport layer 122 has a stacked structure, each layer constituting the hole transport layer 122 emits holes. is a layer that transports to the light layer 123.

[0126] The hole transport layer 122a in FIGS. 4B and 4C is the same as the hole transport layer 122 in FIG. 4A can be employed as the configuration.

[0127] The hole transport layer 122b in FIGS. 4B and 4C (that is, the layer of the hole transport layer 122 closest to the emission light layer 123 side) preferably functions as an electron blocking layer.

[0128] The hole transport layer 122b preferably contains a fourth compound.

[0129] The fourth compound is a hole-transporting material. As the hole-transporting material, those usable for the second compound can be used.

[0130] The HOMO level of the fourth compound is preferably lower than the HOMO level of the third compound . The difference between the HOMO level of the fourth compound and the HOMO level of the third compound is within 0.2 eV , which is preferable.

[0131] The second compound, the third compound, and the fourth compound each have at least one selected from a carbazole skeleton, a dibenzo furan skeleton, a dibenzothiophene skeleton, and an anthracene skeleton , which is preferable.

[0132] When the second compound, the third compound, and the fourth compound have the same hole-transporting skeleton (particularly a dibenzo furan skeleton), hole injection becomes smooth, which is preferable.

[0133] The hole-transporting materials used for the hole injection layer 121, the hole transport layer 122a, and the hole transport layer 122b are As a result of having the above relationship, hole injection into each layer is performed smoothly, and the drive voltage increases and This prevents a state of insufficient holes in the light-emitting layer 123.

[0134] <Luminous layer> The luminescent layer is a layer containing a luminescent substance. The luminescent layer may have one or more types of luminescent substances. This is possible. The luminescent materials include blue, purple, bluish-purple, green, yellowish-green, yellow, orange, and red. Substances that exhibit emission colors such as the above are used as appropriate. In addition, substances that emit near-infrared light are used as emission materials. You can also use this.

[0135] The luminescent layer consists of one or more organic compounds (host material) in addition to the luminescent substance (guest material). It may contain (materials, assisting materials, etc.). One or more types of organic compounds include: Using one or both of the hole-transporting material and the electron-transporting material described in the embodiment. This is possible. Furthermore, bipolar materials may be used as one or more types of organic compounds. stomach.

[0136] There are no particular limitations on the luminescent material that can be used in the luminescent layer, and the singlet excitation energy is A light-emitting material that converts emission to the visible light region or the near-infrared light region, or triplet excitation energy A light-emitting material can be used that converts light emission into visible light or near-infrared light emission.

[0137] Examples of light-emitting materials that convert singlet excitation energy into light emission include fluorescent materials, for example. For example, pyrene derivatives, anthracene derivatives, triphenylene derivatives, fluorene derivatives, Luvazol derivatives, dibenzothiophene derivatives, dibenzofuran derivatives, dibenzoquinone Sarin derivatives, quinoxaline derivatives, pyridine derivatives, pyrimidine derivatives, phenanthrene Examples include pyrene derivatives and naphthalene derivatives. Pyrene derivatives, in particular, have a high luminescence quantum yield. Therefore, it is preferable. A specific example of a pyrene derivative is N,N'-bis(3-methylphenyl) -N,N'-bis[3-(9-phenyl-9H-fluoren-9-yl)phenyl]pyre n-1,6-diamine (abbreviation: 1,6mMemFLPAPrn), N,N'-diphenyl -N,N'-bis[4-(9-phenyl-9H-fluoren-9-yl)phenyl]pyre N-1,6-diamine (abbreviation: 1,6FLPAPrn), N,N'-bis(dibenzofura) N-2-yl)-N,N'-diphenylpyrene-1,6-diamine (abbreviation: 1,6FrA) Prn), N,N'-bis(dibenzothiophen-2-yl)-N,N'-diphenylpy Len-1,6-diamine (abbreviation: 1,6ThAPrn), N,N'-(pyrene-1,6- Diyl)bis[(N-phenylbenzo[b]naphtho[1,2-d]furan)-6-amine ](abbreviation: 1,6BnfAPrn), N,N'-(pyrene-1,6-diyl)bis[(N -phenylbenzo[b]naphtho[1,2-d]furan)-8-amine](abbreviation: 1,6B nfAPrn-02), N,N'-(pyrene-1,6-diyl)bis[(6,N-diphenyl Nylbenzo[b]naphtho[1,2-d]furan)-8-amine (abbreviation: 1,6BnfA) Examples include Prn-03). In particular, these include 1,6FLPAPrn, 1,6mMem Phenomena such as FLPAPrn and 1,6BnfAPrn-03 are representative of pyrenediamine compounds. These condensed aromatic diamine compounds have high hole-trapping properties and excellent luminescence efficiency and reliability. Therefore, it is preferable.

[0138] In addition, 5,6-bis[4-(10-phenyl-9-antryl)phenyl]-2, 2'-Bipyridine (abbreviation: PAP2BPy), 5,6-Bis[4'-(10-phenyl- 9-Anthryl)biphenyl-4-yl]-2,2'-bipyridine (abbreviation: PAPP2B) Py), N,N'-bis[4-(9H-carbazol-9-yl)phenyl]-N,N' -Diphenylstilbene-4,4'-diamine (abbreviation: YGA2S), 4-(9H-Cal Bazole-9-yl)-4'-(10-phenyl-9-anthryl)triphenylamine (Abbreviation: YGAPA), 4-(9H-carbazole-9-yl)-4'-(9,10-di Phenyl-2-anthryl)triphenylamine (abbreviation: 2YGAPPA), N,9-di Phenyl-N-[4-(10-phenyl-9-antryl)phenyl]-9H-carbazo 4-(10-phenyl-9-anthryl)-4 (abbreviation: PCAPA), 4-(10-phenyl-9-anthryl)-4 '-(9-phenyl-9H-carbazole-3-yl)triphenylamine (abbreviation: PC) BAPA), 4-[4-(10-phenyl-9-antryl)phenyl]-4'-(9- Phenyl-9H-carbazole-3-yl)triphenylamine (abbreviation: PCBAPBA) ), perylene, 2,5,8,11-tetra(tert-butyl)perylene (abbreviation: TBP) ), N,N''-(2-tert-butylanthracene-9,10-diyldi-4,1- Phenylene)bis[N,N',N'-triphenyl-1,4-phenylenediamine](abbreviated) Name: DPABPA), N,9-diphenyl-N-[4-(9,10-diphenyl-2-A Nantrillyl]phenyl]-9H-carbazole-3-amine (abbreviation: 2PCAPPA), N -[4-(9,10-diphenyl-2-antryl)phenyl]-N,N',N'-triphenyl Phenyl-1,4-phenylenediamine (abbreviation: 2DPAPPA), 3,10-bis[N -(9-phenyl-9H-carbazole-2-yl)-N-phenylamino]naphtho[2 ,3-b;6,7-b']bisbenzofuran (abbreviation: 3,10PCA2Nbf(IV)- 02) 3,10-bis[N-(dibenzofuran-3-yl)-N-phenylamino]na Futo[2,3-b;6,7-b']bisbenzofuran (abbreviation: 3,10FrA2Nbf( IV)-02), etc., can be used.

[0139] Examples of luminescent materials that convert triplet excitation energy into light include phosphorescent materials and thermally active materials. Examples include thermally activated delayed fluorescence (TADF) materials that exhibit delayed fluorescence.

[0140] Examples of phosphorescent materials include 4H-triazole skeletons, 1H-triazole skeletons, and Organometallic compounds having a midazole, pyrimidine, pyrazine, or pyridine skeleton. Complexes (especially iridium complexes), using phenylpyridine derivatives having electron-withdrawing groups as ligands. Examples include organometallic complexes (especially iridium complexes), platinum complexes, and rare earth metal complexes.

[0141] It exhibits a blue or green color, and the peak wavelength of its emission spectrum is between 450 nm and 570 nm. Examples of phosphorescent materials include the following:

[0142] For example, 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-Triazolat) Iridium(III) (Abbreviation: [Ir (Mptz)3]), Tris[4-(3-biphenyl)-5-isopropyl-3-phenyl Iridium(III) (abbreviation: [Ir(iPrp) Tris[3-(5-biphenyl)-5-isopropyl-4-phenyl]), Tris[3-(5-biphenyl)-5-isopropyl-4-phenyl Iridium(III) (abbreviation: Ir(iPr5b)) Organometallic complexes having a 4H-triazole skeleton, such as tris[3-(3)(3)), [Tyl-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]) has a 1H-triazole skeleton The organometallic complex, fac-tris[1-(2,6-diisopropylphenyl)-2-fe [Nyl-1H-imidazole] Iridium(III) (abbreviation: [Ir(iPrpmi)3] ), Tris[3-(2,6-dimethylphenyl)-7-methylimidazo[1,2-f] [Iridium(III) (abbreviation: Ir(dmpimpt-Me)3)] Organometallic complexes having an imidazole skeleton such as ) and bis[2-(4',6'-difluoro (lophenyl)pyridinate-N,C 2’ Iridium(III) tetrakis(1-pyrazoli) (Abbreviation: Fir6), Bis[2-(4',6'-difluorophenyl)pyryl Dinato-N,C 2’ Iridium(III) picolinate (abbreviation: Firpic), bis {2-[3',5'-bis(trifluoromethyl)phenyl]pyridinato-N,C} 2’} Iridium (III) picolinate (abbreviation: [Ir(CF₃ppy)₂(pic)]), bis[2-(4',6'-difluorophenyl)pyridinato-N,C 2’ iridium( III) acetylacetonate (abbreviation: FIr(acac)) which have electron-withdrawing groups organometallic complexes having phenylpyridine derivatives as ligands are mentioned.

[0143] Examples of phosphorescent materials that exhibit green or yellow color and have a peak wavelength of emission spectrum of 495 nm or more and 590 nm or less include the following materials. are as follows.

[0144] For example, tris(4-methyl-6-phenylpyrimidinato)iridium (III) (abbreviation : [Ir(mppm)₃]), tris(4-t-butyl-6-phenylpyrimidinato)ir idium (III) (abbreviation: [Ir(tBuppm)₃]), (acetylacetonato)bi s(6-methyl-4-phenylpyrimidinato)iridium (III) (abbreviation: [Ir(m ppm)₂(acac)]), (acetylacetonato)bis(6-tert-butyl-4 -phenylpyrimidinato)iridium (III) (abbreviation: [Ir(tBuppm)₂(a cac)]), (acetylacetonato)bis[6-(2-norbornyl)-4-phenyl pyrimidinato]iridium (III) (abbreviation: [Ir(nbppm)₂(acac)] , (acetylacetonato)bis[5-methyl-6-(2-methylphenyl)-4-pheny lpyrimidinato]iridium (III) (abbreviation: [Ir(mpmppm)₂(acac) ), (acetylacetonato)bis{4,6-dimethyl-2-[6-(2,6-dimethyl phenyl)-4-pyrimidinyl-κN³]phenyl-κC}iridium (III) (abbreviation :[Ir(dmppm-dmp)2(acac)]), (acetylacetonato)bis(4 ,6-diphenylpyrimidinato)iridium(III) (abbreviation: [Ir(dppm)2( Organometallic iridium complexes having a pyrimidine skeleton such as (acac), (acetylated iridium complexes Setonato)bis(3,5-dimethyl-2-phenylpyradinate)iridium(III) Abbreviation: [Ir(mppr-Me)2(acac)]), (acetylacetonato)bis(5 -Isopropyl-3-methyl-2-phenylpyradinato) Iridium(III) (abbreviation: Organometallic compounds with a pyrazine skeleton, such as [Ir(mppr-iPr)2(acac)]). Iridium complex, Tris(2-phenylpyridinato-N,C) 2’ Iridium (III) (Abbreviation: [Ir(ppy)3]), bis(2-phenylpyridinato-N,C) 2’ ) Iridi Um(III)acetylacetonate (abbreviation: [Ir(ppy)2(acac)]), Su(benzo[h]quinolinate)iridium(III)acetylacetonate (abbreviation: [I r(bzq)2(acac)]), Tris(benzo[h]quinolinate) Iridium(II I) (abbreviation: [Ir(bzq)3]), Tris(2-phenylquinolinato-N,C) 2’ ) Iridium(III) (abbreviation: [Ir(pq)3]), bis(2-phenylquinolinazole) N,C 2’ ) Iridium(III) acetylacetonate (abbreviation: [Ir(pq)2(a cac)]), [2-(4-phenyl-2-pyridinyl-κN)phenyl-κC]bis[ 2-(2-pyridinyl-κN)phenyl-κC]iridium(III) (abbreviation: [Ir( ppy)2(4dppy)]), bis[2-(2-pyridinyl-κN)phenyl-κC] [2-(4-methyl-5-phenyl-2-pyridinyl-κN)phenyl-κC] Organometallic iridium complex having a pyridine skeleton, bis(2,4-diphenyl-1,3-o Xazolato-N,C 2’ ) Iridium(III) acetylacetonate (abbreviation: [Ir( dpo)2(acac)]), bis{2-[4'-(perfluorophenyl)phenyl] Pyridinate-N,C 2’ Iridium(III) acetylacetonate (abbreviation: [Ir( p-PF-ph)2(acac)]), bis(2-phenylbenzothiazolat-N,C 2 ’ Iridium(III) acetylacetonate (abbreviation: [Ir(bt)2(acac) In addition to organometallic complexes such as ]), tris(acetylacetonato)(monophenanthroline) Rare earth golds such as terbium(III) (abbreviation: [Tb(acac)3(Phen)]) Examples include genus complexes.

[0145] It exhibits a yellow or red color, and the peak wavelength of its emission spectrum is between 570 nm and 750 nm. Examples of phosphorescent materials include the following:

[0146] For example, (diisobutyrylmethanato)bis[4,6-bis(3-methylphenyl)pyrim [Dinato] Iridium(III) (abbreviation: [Ir(5mdppm)2(dibm)]), Su[4,6-bis(3-methylphenyl)pyrimidinato](dipivaloylmethanato)yl Dium(III) (abbreviation: [Ir(5mdppm)2(dpm)]), bis[4,6-di (Naphthalene-1-yl)pyrimidinato](Dipivaloylmethanato) Iridium (III) (Abbreviation: [Ir(d1npm)2(dpm)]), Tris(4-t-butyl-6-phenyl) Like iridium(III) (abbreviation: [Ir(tBuppm)3]) nilpyrimidinato Organometallic complex having a pyrimidine skeleton, (acetylacetonato)bis(2,3,5-) Iridium(III) (Abbreviation: [Ir(tppr)2(acac) )]), Bis(2,3,5-triphenylpyrazinato)(dipivaloylmethanato)iridi Um(III) (abbreviation: [Ir(tppr)2(dpm)]), bis{4,6-dimethyl} -2-[3-(3,5-dimethylphenyl)-5-phenyl-2-pyradinyl-κN]f {enyl-κC}(2,6-dimethyl-3,5-heptanedionato-κ 2 O,O') Iriji Um(III) (abbreviation: [Ir(dmdppr-P)2(dibm)]), bis{4,6 -dimethyl-2-[5-(4-cyano-2,6-dimethylphenyl)-3-(3,5-didimethylphenyl)-3-(3,5-didimethylphenyl)-2-[5-(4-cyano-2,6-2-[5-(4-cyano-2,6-dimethylphenyl)-2-(3,5-didimethylphenyl)- Methylphenyl)-2-pyrazinyl-κN]phenyl-κC}(2,2,6,6-tetra Methyl-3,5-heptanedionato-κ 2 O,O') Iridium(III) (Abbreviation: [I r(dmdppr-dmCP)2(dpm)]), (acetylacetonate)bis[2-methyl Tyl-3-phenylquinoxalinato-N,C 2’ Iridium(III) (abbreviation: [Ir (mpq)2(acac)]), (acetylacetonato)bis(2,3-diphenylquinone Kisarinato-N,C 2’ ) Iridium(III) (abbreviation: [Ir(dpq)2(acac )]), (acetylacetonato)bis[2,3-bis(4-fluorophenyl)quinoxa [Linato] Iridium (III) (abbreviation: [Ir(Fdpq)2(acac)]), Bis{ 4,6-dimethyl-2-[5-(5-cyano-2-methylphenyl)-3-(3,5-di Methylphenyl)-2-pyrazinyl-κN]phenyl-κC}(2,2,6,6-tetra Methyl-3,5-heptanedionato-κ 2 O,O') Iridium(III) (Abbreviation: [I Organometallic compounds with a pyrazine skeleton, such as r(dmdppr-m5CP)2(dpm)]). Complexes, or Tris(1-phenylisoquinolinato-N,C) 2’ ) Iridium (III) (abbreviated) Name: [Ir(piq)3]), bis(1-phenylisoquinolinato-N,C 2’ ) Iridi Um(III)acetylacetonate (abbreviation: [Ir(piq)2(acac)]), S[4,6-dimethyl-2-(2-quinolinyl-κN)phenyl-κC](2,4-phenyl Tangionato-κ 2 Organic compounds with a pyridine skeleton, such as O,O') iridium(III). Metal complex, 2,3,7,8,12,13,17,18-octaethyl-21H,23H- Platinum complexes such as porphyrin platinum(II) (abbreviation: [PtOEP]), tris(1,3) -Diphenyl-1,3-propanedionato)(monophenanthroline)europium(I II) (Abbreviation: [Eu(DBM)3(Phen)]), Tris[1-(2-Tenoyl)- 3,3,3-trifluoroacetonate](monophenanthroline)europium(III Examples include rare earth metal complexes such as [Eu(TTA)3(Phen)] (abbreviated as [Eu(TTA)3(Phen)]).

[0147] Organic compounds used in the light-emitting layer (host material, assist material, etc.) include those with the energy of the light-emitting substance. Select one or more materials that have an energy gap larger than the G-gap. It can be used.

[0148] Organic compounds used in combination with fluorescent materials include those with singlet excited states. It is preferable to use an organic compound with a large position and a small energy level in the triplet excited state. .

[0149] Although some of the examples above overlap, a preferred combination is with luminescent materials (fluorescent materials, phosphorescent materials). From the perspective of combinations, specific examples of organic compounds are shown below.

[0150] Organic compounds that can be used in combination with fluorescent materials include anthracene derivatives. Body, tetracene derivatives, phenanthrene derivatives, pyrene derivatives, chrysene derivatives, diben Examples include condensed polycyclic aromatic compounds such as zo[g,p]chrysene derivatives.

[0151] Specific examples of organic compounds (host materials) used in combination with fluorescent materials include 9-F phenyl-3-[4-(10-phenyl-9-antryl)phenyl]-9H-carbazole (Abbreviation: PCzPA), 3,6-diphenyl-9-[4-(10-phenyl-9-an [Tolyl)phenyl]-9H-carbazole (abbreviation: DPCzPA), 3-[4-(1-na Phthyl)-phenyl]-9-phenyl-9H-carbazole (abbreviation: PCPN), 9,1 0-Diphenylanthracene (abbreviation: DPAnth), N,N-Diphenyl-9-[4- (10-phenyl-9-anthryl)phenyl]-9H-carbazole-3-amine (abbreviated) Name: CzA1PA), 4-(10-phenyl-9-anthryl)triphenylamine (abbreviated) Name: DPhPA), YGAPA, PCAPA, N,9-diphenyl-N-{4-[4-( 10-phenyl-9-antryl)phenyl]phenyl}-9H-carbazole-3-a Min (abbreviation: PCAPBA), N-(9,10-diphenyl-2-anthryl)-N,9 -Diphenyl-9H-carbazole-3-amine (abbreviation: 2PCAPA), 6,12-di Methoxy-5,11-diphenylchrysene, N,N,N',N',N'',N'',N' '',N'''-Octaphenyldibenzo[g,p]chrysene-2,7,10,15-Te Traamine (abbreviation: DBC1), 9-[4-(10-phenyl-9-anthracenyl) [phenyl]-9H-carbazole (abbreviation: CzPA), 7-[4-(10-phenyl-9- Anthryl)phenyl]-7H-dibenzo[c,g]carbazole (abbreviation: cgDBCz) PA), 6-[3-(9,10-diphenyl-2-anthryl)phenyl]-benzo[b ]Naphtho[1,2-d]furan (abbreviation: 2mBnfPPA), 9-phenyl-10-{4 -(9-phenyl-9H-fluoren-9-yl)biphenyl-4'-yl}anthrace 9,10-bis(3,5-diphenylphenyl)anthracene (abbreviation: FLPPA), (Abbreviation: DPPA), 9,10-di(2-naphthyl)anthracene (Abbreviation: DNA), 2 -tert-butyl-9,10-di(2-naphthyl)anthracene (abbreviation: t-BuDN) A) 9,9'-biantril (abbreviation: BANT), 9,9'-(stilbene-3,3' -Diphenanthrene (abbreviation: DPNS), 9,9'-(Stilbene-4,4'- Diyl)diphenanthrene (abbreviation: DPNS2), 1,3,5-tri(1-pyrenyl)be Nzen (abbreviation: TPB3), 5,12-diphenyltetracene, 5,12-bis(bife Nyl-2-yl)tetracene, 9-(1-naphthyl)-10-[4-(2-naphthyl)ph Examples include [enyl]anthracene (abbreviated as αN-βNPAnth).

[0152] Organic compounds used in combination with phosphorescent materials include those with the triplet excitation energy of the phosphorescent material. - (The energy difference between the ground state and the triplet excited state) is greater than the triplet excitation energy. You should select an organic compound.

[0153] Multiple organic compounds (e.g., a first host material and a second host material) are used to form an excited complex. When using a light-emitting material (or assist material, etc.) in combination with a light-emitting material, these It is preferable to use a mixture of multiple organic compounds with phosphorescent materials (especially organometallic complexes). .

[0154] By using this configuration, the energy transfer from the excited complex to the luminescent material, called Ex, is achieved. Using TET (Exciplex-Triplet Energy Transfer) This allows for efficient emission. Furthermore, as a combination of multiple organic compounds, Compounds that readily form complexes are preferred, as are compounds that readily accept holes (hole transport materials), It is particularly preferable to combine it with a compound that readily accepts electrons (electron transport material). An excited complex is formed that exhibits emission that overlaps with the wavelength of the lowest-energy absorption band of the luminescent material. By selecting a combination that works well, energy transfer becomes smoother and more efficient. Light emission can be obtained. Specific examples of hole transport materials and electron transport materials are as follows: The materials shown in this embodiment can be used. This configuration allows for high efficiency of the light-emitting device. It can achieve high efficiency, low voltage operation, and long lifespan simultaneously.

[0155] As for combinations of materials that form excited complexes, the HOMO level of the hole transport material is the electron transport level. It is preferable that the value is above the HOMO level of the hole transport material. It is preferable that the low-altitude orbital level is greater than or equal to the LUMO level of the electron-transporting material. The MO level and HOMO level are measured by cyclic voltammetry (CV). This can be derived from the electrochemical properties (reduction potential and oxidation potential) of the material being used.

[0156] The formation of excited complexes is observed, for example, in the emission spectra of hole transport materials and electron transport materials. The emission spectra of the individual material and the mixed film made by mixing these materials were compared, and the emission spectrum of the mixed film was determined. The culprit shifts to longer wavelengths than the emission spectrum of each material (or a new one is added to the longer wavelength side). This can be confirmed by observing phenomena (with peaks). Alternatively, hole transport Transient photoluminescence (PL) of materials, transient PL of electron transport materials, and these materials The transient PL of mixed films was compared, and the transient PL lifetime of the mixed film was compared to the transient PL lifetime of each material. Differences in transient response, such as having longer-lived components or a larger proportion of delayed components. This can be confirmed by observation. Furthermore, the transient PL mentioned above is transient electron It can also be read as mineness (EL). That is, transient EL of hole transporting materials. We compared the transient EL of electron-transporting materials and the transient EL of mixed films thereof to identify differences in transient response. The formation of excited complexes can also be confirmed by observation.

[0157] Organic compounds that can be used in combination with phosphorescent substances include aromatic amines. Compounds having a fragrant amine skeleton), carbazole derivatives (compounds having a carbazole skeleton) (substance), dibenzothiophene derivatives (thiophene derivatives), dibenzofuran derivatives (furan) Derivatives), zinc and aluminum-based metal complexes, oxadiazole derivatives, triazole derivatives Conductors, benzimidazole derivatives, quinoxaline derivatives, dibenzoquinoxaline derivatives, Pyrimidine derivatives, triazine derivatives, pyridine derivatives, bipyridine derivatives, phenant Examples include lorine derivatives.

[0158] Aromatic amines, carbazole derivatives, and dibenzothiops are organic compounds with high hole transport capabilities. Specific examples of benzofuran derivatives and dibenzofuran derivatives include the following substances.

[0159] Examples of carbazole derivatives include bicarbazole derivatives (e.g., 3,3'-bicarbazole Examples include aromatic amines having a carbazolyl group, etc. (e.g., carbazol derivatives).

[0160] Specifically, examples of bicarbazole derivatives (e.g., 3,3'-bicarbazole derivatives) include: This is 3,3'-bis(9-phenyl-9H-carbazole) (abbreviation: PCCP), 9,9 '-Bis(1,1'-biphenyl-4-yl)-3,3'-bi-9H-carbazole,9 ,9'-bis(1,1'-biphenyl-3-yl)-3,3'-bi-9H-carbazole , 9-(1,1'-biphenyl-3-yl)-9'-(1,1'-biphenyl-4-yl) )-9H,9'H-3,3'-bicarbazole (abbreviation: mBPCCBP), 9-(2-na Phthyl)-9'-phenyl-9H,9'H-3,3'-bicarbazole (abbreviation: βNCC) Examples include P).

[0161] Aromatic amines having a carbazolyl group include, specifically, PCBA1BP, N-(4 -biphenyl)-N-(9,9-dimethyl-9H-fluoren-2-yl)-9-phenyl ru-9H-carbazole-3-amine (abbreviation: PCBiF), PCBBiF, PCBBi 1BP, PCBANB, PCBNBB, 4-phenyldiphenyl-(9-phenyl-9H -Carbazole-3-yl)amine (abbreviation: PCA1BP), N,N'-bis(9-phenyl)amine Nilcarbazole-3-yl)-N,N'-diphenylbenzene-1,3-diamine (abbreviated) Name: PCA2B), N,N',N''-triphenyl-N,N',N''-tris(9- Phenylcarbazole-3-yl)benzene-1,3,5-triamine (abbreviation: PCA3) B) 9,9-dimethyl-N-phenyl-N-[4-(9-phenyl-9H-carbazol) [Lu-3-yl]phenyl]fluoren-2-amine (abbreviation: PCBAF), PCBASF ,3-[N-(9-phenylcarbazole-3-yl)-N-phenylamino]-9-f Phenylcarbazole (abbreviation: PCzPCA1), 3,6-bis[N-(9-phenylcarbazole) [Bazole-3-yl)-N-phenylamino]-9-phenylcarbazole (abbreviation: PC) zPCA2), 3-[N-(1-naphthyl)-N-(9-phenylcarbazole-3-I [Lu)amino]-9-phenylcarbazole (abbreviation: PCzPCN1), 3-[N-(4- Diphenylaminophenyl)-N-phenylamino]-9-phenylcarbazole (abbreviation) :PCzDPA1), 3,6-bis[N-(4-diphenylaminophenyl)-N-fe Nylamino]-9-phenylcarbazole (abbreviation: PCzDPA2), 3,6-bis[N -(4-diphenylaminophenyl)-N-(1-naphthyl)amino]-9-phenyl Luvazole (abbreviation: PCzTPN2), 2-[N-(9-phenylcarbazole-3-I [Phenylamino]spiro-9,9'-bifluorene (abbreviation: PCASF), N -[4-(9H-carbazole-9-yl)phenyl]-N-(4-phenyl)phenyl Aniline (abbreviation: YGA1BP), N,N'-bis[4-(carbazole-9-yl) [phenyl]-N,N'-diphenyl-9,9-dimethylfluorene-2,7-diamine (abbreviated) Name: YGA2F), 4,4',4''-Tris(carbazole-9-yl)triphenyl Examples include amines (abbreviated as TCTA).

[0162] In addition to the above, 3-[4-(9-phenanthryl)-phenanthryl is also a carbazole derivative. [nyl]-9-phenyl-9H-carbazole (abbreviation: PCPPn), PCPN, 1,3- Bis(N-carbazolyl)benzene (abbreviation: mCP), 4,4'-di(N-carbazolyl ) Biphenyl (abbreviation: CBP), 3,6-bis(3,5-diphenylphenyl)-9-f Enylcarbazole (abbreviated as CzTP), 1,3,5-tris[4-(N-carbazolyl) Examples include phenylbenzene (abbreviated as TCPB) and CzPA.

[0163] Thiophene derivatives (compounds having a thiophene skeleton) and furan derivatives (compounds having a furan skeleton) Specifically, the compound is 4,4',4''-(benzene-1,3,5-tri Il)tri(dibenzothiophene) (abbreviation: DBT3P-II), 2,8-diphenyl- 4-[4-(9-phenyl-9H-fluoren-9-yl)phenyl]dibenzothiophen (Abbreviation: DBTFLP-III), 4-[4-(9-phenyl-9H-fluorene-9) -yl)phenyl]-6-phenyldibenzothiophene (abbreviation: DBTFLP-IV) Which compounds have a thiophene skeleton, 4-{3-[3-(9-phenyl-9H-fluore] [Phenyl-9-yl]phenyl]phenyl}dibenzofuran (abbreviation: mmDBFFLBi-II) Examples include:

[0164] Specifically, aromatic amines include 4,4'-bis[N-(1-naphthyl)-N-fe [Nylamino]biphenyl (abbreviation: NPB or α-NPD), N,N'-bis(3-methyl) (diphenyl)-N,N'-diphenyl-[1,1'-biphenyl]-4,4'-diamine (Abbreviation: TPD), 4,4'-bis[N-(spiro-9,9'-bifluoren-2-yl) )-N-phenylamino]biphenyl (abbreviation: BSPB), BPAFLP, mBPAFL P,N-(9,9-dimethyl-9H-fluoren-2-yl)-N-{9,9-dimethyl -2-[N'-phenyl-N'-(9,9-dimethyl-9H-fluorene-2-yl) Mino]-9H-fluoren-7-yl}phenylamine (abbreviation: DFLADFL), N- (9,9-dimethyl-2-diphenylamino-9H-fluoren-7-yl)diphenyl Amine (abbreviation: DPNF), 2-[N-(4-diphenylaminophenyl)-N-phenyl Luamino]spiro-9,9'-bifluorene (abbreviation: DPASF), 2,7-bis[N- (4-diphenylaminophenyl)-N-phenylamino]spiro-9,9'-bifluor Len (abbreviation: DPA2SF), 4,4',4''-tris[N-(1-naphthyl)-N- Phenylaminotriphenylamine (abbreviation: 1'-TNATA), 4,4',4''- Tris(N,N-diphenylamino)triphenylamine (abbreviation: TDATA), 4,4 ',4''-Tris[N-(3-methylphenyl)-N-phenylamino]triphenyl Amine (abbreviation: m-MTDATA), N,N'-di(p-tril)-N,N'-diphen ru-p-phenylenediamine (abbreviation: DTDPPA), 4,4'-bis[N-(4-diph Phenylaminophenyl)-N-phenylamino]biphenyl (abbreviation: DPAB), 4,4 '-Bis(N-{4-[N'-(3-methylphenyl)-N'-phenylamino]phen 1,3,5-Tris[N]-N-phenylamino)biphenyl (abbreviation: DNTPD), 1,3,5-Tris[N -(4-diphenylaminophenyl)-N-phenylamino]benzene (abbreviation: DPA3) Examples include B).

[0165] Organic compounds with high hole transport capabilities include poly(N-vinylcarbazole) (abbreviation: PVK). ), poly(4-vinyltriphenylamine) (abbreviation: PVTPA), poly[N-(4-{ N'-[4-(4-diphenylamino)phenyl]phenyl-N'-phenylamino}phenyl [Petryl)methacrylamide] (abbreviation: PTPDMA), poly[N,N'-bis(4-butyl] [N,N'-bis(phenyl)benzidine] (abbreviation: Poly-TPD) Any polymer compound can be used.

[0166] Examples of zinc and aluminum-based metal complexes, which are organic compounds with high electron transport capabilities, include Tris(8-quinolinolato)aluminum(III) (abbreviation: Alq), Tris(4- Methyl-8-quinolinolato)aluminum(III) (abbreviation: Almq3), bis(10 -Hydroxybenzo[h]quinolinate)beryllium(II) (abbreviation: BeBq2), bis (2-methyl-8-quinolinolate)(4-phenylphenolate)aluminum(III) (Abbreviation: BAlq), bis(8-quinolinolato)zinc(II) (Abbreviation: Znq), etc. Examples include metal complexes having a noline skeleton or a benzoquinoline skeleton.

[0167] In addition, bis[2-(2-benzoxazolyl)phenolate]zinc(II) (abbreviation: Zn) PBO), bis[2-(2-benzothiazolyl)phenolate]zinc(II) (abbreviation: Zn) Metal complexes containing oxazole-based or thiazole-based ligands, such as BTZ, can also be used. It is possible.

[0168] Organic compounds with high electron transport properties include oxadiazole derivatives, triazole derivatives, and ve Nzoimidazole derivatives, quinoxaline derivatives, dibenzoquinoxaline derivatives, phenan A specific example of a trolin derivative is 2-(4-biphenylyl)-5-(4-tert- Tylphenyl)-1,3,4-oxadiazole (abbreviation: PBD), 1,3-bis[5- (p-tert-butylphenyl)-1,3,4-oxadiazole-2-yl]benz (abbreviation: OXD-7), 9-[4-(5-phenyl-1,3,4-oxadiazole- 2-yl)phenyl]-9H-carbazole (abbreviation: CO11), 3-(4-biphenyl (Lu)-4-phenyl-5-(4-tert-butylphenyl)-1,2,4-triazole TAZ (abbreviation), 3-(4-tert-butylphenyl)-4-(4-ethylphenyl (p-EtTAZ)-5-(4-biphenylyl)-1,2,4-triazole , 2-{4-[9,10-di(naphthalene-2-yl)-2-anthryl]phenyl}- 1-Phenyl-1H-benzimidazole (abbreviation: ZADN), 2,2',2''-(1 ,3,5-benzenetriyl)tris(1-phenyl-1H-benzoimidazole) (abbreviated) Name: TPBI), 2-[3-(dibenzothiophen-4-yl)phenyl]-1-phenyl Ru-1H-benzimidazole (abbreviation: mDBTBIm-II), 4,4'-bis(5- Methylbenzoxazole-2-yl)stilbene (abbreviation: BzOs), bathophenant Lorin (abbreviation: Bphen), vasocuproine (abbreviation: BCP), 2,9-bis(naph Talene-2-yl)-4,7-diphenyl-1,10-phenanthroline (abbreviation: NBp) hen), 2-[3-(dibenzothiophen-4-yl)phenyl]dibenzo[f,h] Quinoxaline (abbreviation: 2mDBTPDBq-II), 2-[3'-(dibenzothiophene) [-4-yl)biphenyl-3-yl]dibenzo[f,h]quinoxaline (abbreviation: 2mDB) TBPDBq-II), 2-[3'-(9H-carbazol-9-yl)biphenyl-3 -Il]dibenzo[f,h]quinoxaline (abbreviation: 2mCzBPDBq), 2-[4-( 3,6-diphenyl-9H-carbazole-9-yl)phenyl]dibenzo[f,h]k Noxaline (abbreviation: 2CzPDBq-III), 7-[3-(dibenzothiophene-4- [Iyl)phenyl]dibenzo[f,h]quinoxaline (abbreviation: 7mDBTPDBq-II) , and 6-[3-(dibenzothiophen-4-yl)phenyl]dibenzo[f,h]quino Examples include xalin (abbreviated as 6mDBTPDBq-II).

[0169] Organic compounds with high electron transport capabilities, heterocyclic compounds having a diazine skeleton, triazine skeleton Specific examples of heterocyclic compounds having a pyridine skeleton include 4,6 -Bis[3-(phenanthrene-9-yl)phenyl]pyrimidine (abbreviation: 4,6mPn) P2Pm), 4,6-bis[3-(4-dibenzothienyl)phenyl]pyrimidine (abbreviation) :4,6mDBTP2Pm-II), 4,6-bis[3-(9H-carbazole-9-I) [Phenyl]pyrimidine (abbreviation: 4,6mCzP2Pm), 2-{4-[3-(N-Phenyl]pyrimidine [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 Nyl-2,3'-bi-9H-carbazole (abbreviation: mPCCzPTzn-02), 2-[ 3'-(9,9-dimethyl-9H-fluoren-2-yl)-1,1'-biphenyl-3 -yl]-4,6-diphenyl-1,3,5-triazine (abbreviation: mFBPTzn), 2 -[(1,1'-biphenyl)-4-yl]-4-phenyl-6-[9,9'-spirobyl] (9H-fluorene)-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: mBnfBPTz n), 2-{3-[3-(benzo[b]naphtho[1,2-d]furan-6-yl)phen [L]phenyl}-4,6-diphenyl-1,3,5-triazine (abbreviation: mBnfBPT) (zn-02), 3,5-bis[3-(9H-carbazole-9-yl)phenyl]pyridin (Abbreviation: 35DCzPPy), 1,3,5-tri[3-(3-pyridyl)phenyl]be Examples include Nzen (abbreviated as TmPyPB).

[0170] Organic compounds with high electron transport capabilities include poly(2,5-pyridinediyl) (abbreviation: PPy ), poly[(9,9-dihexylfluorene-2,7-diyl)-co-(pyridine-3 ,5-diyl)](abbreviation: PF-Py), poly[(9,9-dioctylfluorene-2, 7-diyl)-co-(2,2'-bipyridine-6,6'-diyl)(abbreviation: PF-B) Polymer compounds such as Py can also be used.

[0171] TADF materials are materials with S1 levels (singlet excited state energy levels) and T1 levels (triplet excited state energy levels). The difference from the energy level of the initial state is small, and the triplet excitation energy is obtained by reverse intersystem crossing. It is a material that has the function of converting energy to singlet excitation energy. Therefore, the triplet excitation energy is converted to the singlet excitation energy by a small amount of thermal energy. Upconversion (reverse intersystem crossing) is possible, and singlet excited states can be efficiently generated. Yes, it is possible. Furthermore, the triplet excitation energy can be converted into luminescence. (Thermal-activated delayed fluorescence) The conditions under which this can be efficiently obtained are that the energy difference between the S1 and T1 levels is 0 eV or greater. The voltage is 2eV or less, preferably 0eV or more and 0.1eV or less. Delayed fluorescence in DF materials is a type of fluorescence that exhibits a spectrum similar to normal fluorescence but with a significantly longer lifetime. It refers to a very long period of luminescence. Its lifespan is 10 -6 10 seconds or more, preferably 10 -3 It is more than a second.

[0172] Excited complexes, which form excited states using two different substances, have an extremely small difference between the S1 and T1 levels. TADF materials capable of converting triplet excitation energy to singlet excitation energy It functions as such.

[0173] The phosphorescence spectrum observed at low temperatures (e.g., 77K to 10K) serves as an indicator of the T1 level. This can be used. As for the TADF material, the short-wavelength tail of its fluorescence spectrum is tangent. Draw a line, and set the energy at the wavelength of that extrapolation line as the S1 level, and the short wavelength side of the phosphorescence spectrum When a tangent line is drawn at the tail and the energy of the wavelength of the extrapolation line is taken as the T1 level, then the S1 It is preferable that the difference between and T1 is 0.3 eV or less, and even more preferable that it is 0.2 eV or less. preferable.

[0174] TADF materials may be used as guest materials or as host materials.

[0175] Examples of TADF materials include fullerenes and their derivatives, and acridines such as proflavin. Examples include derivatives and eosin. Also, magnesium (Mg), zinc (Zn), cadmium Um (Cd), tin (Sn), platinum (Pt), indium (In), or palladium Examples of metal-containing porphyrins include those containing (Pd), etc. For example, protoporphyrin-tin fluoride complex (abbreviation: SnF2 (Proto IX)) Mesoporphyrin-tin fluoride complex (abbreviation: SnF2 (Meso IX)), hematopo Rufirin-tin fluoride complex (abbreviation: SnF2(Hemato IX)), copropolph Fluorine tetramethyl ester-tin fluoride complex (abbreviation: SnF2(Copro III- 4Me)), Octaethylporphyrin-tin fluoride complex (abbreviation: SnF2(OEP)) , Ethioporphyrin-tin fluoride complex (abbreviation: SnF2(Etio I)), Octae Examples include tilporphyrin-platinum chloride complex (abbreviated as PtCl2OEP).

[0176] In addition, 2-(biphenyl-4-yl)-4,6-bis(12-phenylindoro[ 2,3-a]carbazole-11-yl)-1,3,5-triazine (abbreviation: PIC-T RZ), PCCzPTzn, 2-[4-(10H-phenoxazine-10-yl)pheni [Lu]-4,6-diphenyl-1,3,5-triazine (abbreviation: PXZ-TRZ), 3-[ 4-(5-phenyl-5,10-dihydrophenazine-10-yl)phenyl]-4,5 -Diphenyl-1,2,4-triazole (abbreviation: PPZ-3TPT), 3-(9,9- Dimethyl-9H-acridine-10-yl)-9H-xanthene-9-one (abbreviation: AC) RXTN), bis[4-(9,9-dimethyl-9,10-dihydroacrylidine)phenyl ]Sulfone (abbreviation: DMAC-DPS), 10-phenyl-10H,10'H-spiro[ Acridine-9,9'-anthracene]-10'-one (abbreviation: ACRSA), 4-(9 '-phenyl-3,3'-bi-9H-carbazole-9-yl)benzofloxacin[3,2-d ]pyrimidine (abbreviation: 4PCCzBfpm), 4-[4-(9'-phenyl-3,3'- B-9H-carbazole-9-yl)phenyl]benzofl[3,2-d]pyrimidine ( Abbreviation: 4PCCzPBfpm), 9-[3-(4,6-diphenyl-1,3,5-tri [Zin-2-yl)phenyl]-9'-phenyl-2,3'-bi-9H-carbazole (abbreviated) Name: mPCCzPTzn-02) and other π-electron-rich and π-electron-deficient complex aromatic rings A heterocyclic compound having a ring can be used. The heterocyclic compound is a π-electron-rich heterocyclic compound. Because it has both an aromatic ring and a π-electron-deficient heteroaromatic ring, it exhibits high electron transport and hole transport properties. This is preferable. Furthermore, instead of a π-electron-deficient heteroaromatic ring, an electron-withdrawing group such as a cyano group may be attached. Combined aromatic rings may also be used. Alternatively, instead of π-electron-deficient complex aromatic rings, π-electron-deficient A skeleton can be used. Similarly, instead of a π-electron-rich heteroaromatic ring, a π-electron-rich type The skeleton can be used.

[0177] Among skeletons having a π-electron-deficient heteroaromatic ring, pyridine skeleton, diazine skeleton (pyrimidine) The skeletons (pyrazine skeleton, pyridazine skeleton) and triazine skeleton are stable and reliable. Therefore, it is preferable. In particular, the benzoflopyrimidine skeleton, the benzothienopyrimidine skeleton, and benzo The flopyrazine skeleton and benzothienopyrazine skeleton have high electron-accepting properties and good reliability. preferable.

[0178] Among skeletons having a π-electron-rich heteroaromatic ring, the acridine skeleton, the phenoxazine skeleton, and fu The phenothiazine skeleton, furan skeleton, thiophene skeleton, and pyrrole skeleton are stable and reliable. It is preferable to have at least one of the said skeletons for better performance. In particular, dibenzofuran Skeleton, dibenzothiophene skeleton, indole skeleton, carbazole skeleton, indolocarbazo 3-(9-phenyl-9H-carbazole-3-yl) A -9H-carbazole skeleton is preferred.

[0179] Furthermore, in substances in which a π-electron-rich heteroaromatic ring and a π-electron-deficient heteroaromatic ring are directly bonded, Both the donor properties of the electron-excess type heteroaromatic ring and the acceptor properties of the π-electron-deficient type heteroaromatic ring are strong. This is particularly preferable because it reduces the energy difference between the singlet excited state and the triplet excited state.

[0180] As π-electron-rich skeletons, aromatic amine skeletons, phenazine skeletons, and the like can be used. Examples of π-electron-deficient skeletons include xanthene skeletons, thioxanthene dioxide skeletons, and oxadioxide skeletons. Azole skeleton, triazole skeleton, imidazole skeleton, anthraquinone skeleton, phenylbone Boron-containing skeletons such as or and volanthrene, and nitriles such as benzonitrile or cyanobenzene. Aromatic rings or heteroaromatic rings having a cyano group or a benzophenone, carbonyl skeletons, Phosphine oxide skeletons, sulfone skeletons, etc., can be used.

[0181] Furthermore, when using TADF material as a luminescent substance, it should be used in combination with other organic compounds. It is also possible to combine it with the aforementioned host material (hole transport material, electron transport material). It can be made to work. When using TADF material, the S1 level of the host material is the TADF material It is preferable that the T1 level of the host material is higher than the S1 level of the TADF material. A higher rank is preferable.

[0182] Alternatively, a TADF material may be used as the host material and a fluorescent material as the guest material. When ADF material is used as the host material, the triplet excitation energy generated in TADF material However, through reverse intersystem crossing, it is converted into singlet excitation energy, and further into the luminescent material. By moving it, the luminescence efficiency of the light-emitting device can be increased. At this time, TADF material The material functions as an energy donor, and the light-emitting material functions as an energy acceptor. Therefore, using TADF material as the host material means that fluorescent material is used as the guest material. It is very effective when using quality. Also, in order to obtain high luminescence efficiency in this case, T The S1 level of the ADF material is preferably higher than that of the fluorescent material. The T1 level of the DF material is preferably higher than the S1 level of the fluorescent material. Therefore, TA The T1 level of the DF material is preferably higher than that of the fluorescent material.

[0183] Furthermore, T exhibits emission that overlaps with the wavelength of the lowest energy absorption band of the fluorescent material. It is preferable to use ADF material. This allows the fluorescent material to be converted from TADF material. This is preferable because it allows for smoother transfer of excitation energy and efficient emission.

[0184] Furthermore, singlet excitation energy is efficiently generated from triplet excitation energy through reverse intersystem crossing. For this to occur, it is preferable that carrier recombination occurs in the TADF material. The triplet excitation energy generated by the DF material is transferred to the triplet excitation energy of the fluorescent material. It is preferable not to do so. To that end, the fluorescent material has a luminescent phosphodiolus ( It is preferable to have a protecting group around the skeleton that causes light emission. The protecting group is a π bond. Substituents that do not have a substituent are preferred, saturated hydrocarbons are preferred, specifically those having 3 to 10 carbon atoms. The alkyl group below, substituted or unsubstituted cycloalkyl groups with 3 to 10 carbon atoms, carbon Examples include trialkylsilyl groups with a number between 3 and 10, and it is even preferable if there are multiple protecting groups. Substituents that do not have a π bond have poor carrier transport function, therefore carrier transport and The distance between the TADF material and the fluorescent material's luminescent phosphate is minimized without affecting carrier recombination. It can keep the distance away. Here, a luminescent group is the substance that causes light emission in a fluorescent substance. This refers to an atomic group (skeleton). The luminescent group preferably has a skeleton with π bonds and contains an aromatic ring. It is preferable that it has a condensed aromatic ring or a condensed heteroaromatic ring. Examples of compound aromatic rings include the phenanthrene skeleton, stilbene skeleton, acridone skeleton, and pheno Examples include xazine skeletons and phenothiazine skeletons. In particular, naphthalene skeletons and anthracene skeletons. Skeleton, fluorene skeleton, chrysene skeleton, triphenylene skeleton, tetracene skeleton, pyrene skeleton It has a perylene skeleton, coumarin skeleton, quinacridone skeleton, and naphthobisbenzofuran skeleton. Fluorescent materials are preferred because they have a high fluorescence quantum yield.

[0185] <Electron transport layer> The electron transport layer 124 is a layer that transports electrons injected from the cathode 102 to the light-emitting layer 123. .

[0186] The electron transport layer 124 comprises a third organic compound and a first substance.

[0187] The third type of organic compound is an electron-transporting material. Electron-transporting materials transport electrons more efficiently than holes. It is highly likely.

[0188] The third organic compound has a highest occupied orbital level (HOMO level) of -6.0 eV or higher. This is preferable.

[0189] The third organic compound has an electron mobility of 1 at a square root of the electric field strength [V / cm] of 600. ×10 -7 cm 2 / Vs or more 1×10 -5 cm 2 It is preferable that / Vs be less than or equal to 1 × 10 -7 cm 2 / Vs or more 5×10 -5 cm 2 It is even more preferable that / Vs is less than or equal to / Vs.

[0190] The square root of the electric field strength [V / cm] of the third organic compound is 600, and the electron mobility is that of the luminescent layer. The square root of the electric field strength [V / cm] of the host material 123 is greater than the electron mobility at 600. Smaller is preferable. By lowering the electron transport properties in the electron transport layer 124, light emission is achieved. The amount of electrons injected into layer 123 can be controlled, resulting in an electron-rich state in the light-emitting layer 123. This can prevent that from happening.

[0191] The third organic compound preferably has an anthracene skeleton, and is compound with an anthracene skeleton. It is even more preferable to have an elementary ring skeleton. The heterocyclic skeleton may be a nitrogen-containing five-membered ring skeleton. Preferably, the nitrogen-containing five-membered ring skeleton may be a pyrazole ring, an imidazole ring, or an oxazo ring. Having a nitrogen-containing five-membered ring skeleton that includes two complex atoms in the ring, such as a thiazole ring or a thiazole ring. That is particularly preferable.

[0192] In addition, some electron transport materials that can be used in the above host material, and the above fluorescence The materials listed as materials that can be used as host materials in combination with photomaterials are electrons It can be used in the transport layer 124.

[0193] A third organic compound is, for example, 2-{4-[9,10-di(naphthalene-2-yl )-2-anthryl]phenyl}-1-phenyl-1H-benzimidazole (abbreviation: Z ADN), 9-(1-naphthyl)-10-[4-(2-naphthyl)phenyl]anthrace (Abbreviation: αN-βNPAnth), 9-[4-(10-phenyl-9-anthracenyl) )phenyl]-9H-carbazole (abbreviation: CzPA), 7-[4-(10-phenyl- 9-Anthryl)phenyl]-7H-dibenzo[c,g]carbazole (abbreviation: cgDB) Examples include CzPA.

[0194] Other examples of a third organic compound include electron transport materials that can be used in the above-mentioned light-emitting layer. Furthermore, using organic compounds (host materials) that can be used in combination with fluorescent light-emitting substances. It is possible to be there.

[0195] The first substance is a metal, a metal salt, a metal oxide, or an organometallic salt.

[0196] Examples of metals include alkali metals, alkaline earth metals, and rare earth metals. Examples include Li, Na, K, Rb, Cs, Mg, Ca, Sr, and Ba.

[0197] Examples of metal salts include halides of the above-mentioned metals and carbonates of the above-mentioned metals. Specifically, LiF, NaF, KF, RbF, CsF, MgF2, CaF2, SrF2 , BaF2, LiCl, NaCl, KCl, RbCl, CsCl, MgCl2, CaCl Examples include SrCl2, BaCl2, Li2CO3, and Cs2CO3.

[0198] Examples of metal oxides include oxides of the above-mentioned metals. Specifically, Li2O, Examples include Na2O, Cs2O, MgO, and CaO.

[0199] Examples of organometallic salts include organometallic complexes.

[0200] The first substance is an organometallic complex containing an alkali metal or alkaline earth metal. It is preferable.

[0201] The first substance comprises a ligand having nitrogen and oxygen, and an alkali metal or alkaline earth metal. It is preferable that the organometallic complex has the following properties.

[0202] The first substance comprises a quinolinol ligand and an alkali metal or alkaline earth metal. It is preferable that it be an organometallic complex.

[0203] Examples of the above organometallic complexes include 8-(quinolinolato)lithium (abbreviation: Liq) and 8-(quinolinolato). (Nolinolato)sodium (abbreviation: Naq), 8-(quinolinolato)potassium (abbreviation: Kq) ), (8-kinokilinolato)magnesium (abbreviation: Mgq2), (8-kinokilinolato) Examples include zinc (abbreviated as Znq2).

[0204] Liq is particularly preferred as the first substance.

[0205] As shown in Figure 4C, the electron transport layer 124 is connected to the electron transport layer 124a on the light-emitting layer 123 side, and It may have an electron transport layer 124b on the pole 102 side. Electron transport layer 124a and electron transport layer In the case of 124b, it is preferable that the concentration ratio of the third organic compound to the first substance is different. In the electron transport layer 124a, it is preferable that the concentration of the first substance is higher than in the electron transport layer 124b. It seems so.

[0206] <Electron injection layer> The electron injection layer 125 is a layer that enhances the efficiency of electron injection from the cathode 102. The difference between the work function value of the material and the LUMO level value of the material used in the electron injection layer 125 is: A low value (within 0.5 eV) is preferable.

[0207] The electron injection layer 125 contains lithium, cesium, lithium fluoride (LiF), and cesium fluoride. Lithium (CsF), calcium fluoride (CaF2), 8-(quinolinolato)lithium (abbreviation: Liq), 2-(2-pyridyl)phenolatritium (abbreviation: LiPP), 2-(2-pyridyl)phenolatritium Lysyl)-3-pyridinolatritium (abbreviation: LiPPy), 4-phenyl-2-(2- Pyridyl phenolatritium (abbreviation: LiPPP), lithium oxide (LiO x ), charcoal Alkali metals such as cesium acid, alkaline earth metals, or compounds thereof are used. It is possible to use rare earth metal compounds such as erbium fluoride (ErF3). This is possible. Furthermore, an electride may be used in the electron injection layer. For example, a substance obtained by adding a high concentration of electrons to a mixed oxide of calcium and aluminum. These can be listed. Furthermore, the materials that constitute the electron transport layer mentioned above can also be used.

[0208] Furthermore, the electron injection layer is a composite material containing an electron transport material and a donor material (electron-donating material). Materials may be used. In such composite materials, electrons are generated in the organic compound by the electron donor. Therefore, it has excellent electron injection and electron transport properties. In this case, as an organic compound, It is preferable that the material is excellent in transporting the generated electrons, specifically, for example, the electrons mentioned above Transportable materials (such as metal complexes and heteroaromatic compounds) can be used as electron donors. Any substance that exhibits electron-donating properties to organic compounds is acceptable. Specifically, alkali metals and Alkaline earth metals and rare earth metals are preferred, as are lithium, cesium, magnesium, and calcium. Examples include um, erbium, and ytterbium. Also, alkali metal oxides and alkalis... Lithium-earth metal oxides are preferred, such as lithium oxide, calcium oxide, and barium oxide. These can be listed. Furthermore, Lewis bases such as magnesium oxide can also be used. Also, Organic compounds such as tetrathiafulvalene (abbreviated as TTF) can also be used.

[0209] Furthermore, the fabrication of a light-emitting device according to one aspect of the present invention involves vacuum processes such as vapor deposition and spin Solution processes such as coating and inkjet methods can be used. Vapor deposition can also be used. In some cases, sputtering, ion plating, ion beam deposition, molecular beam deposition, Physical vapor deposition methods such as vacuum deposition (PVD) and chemical vapor deposition (CVD) can be used. Yes, it is possible. In particular, the functional layers included in the EL layer (hole injection layer, hole transport layer, light-emitting layer, electron transport layer, For the electron injection layer, methods include vapor deposition (vacuum deposition, etc.) and coating (dip coating, dip coating, etc.) (Inkjet method, bar coating method, spin coating method, spray coating method, etc.), printing method (inkjet) Printing method, screen printing method, offset printing method, flexographic printing method It can be formed by methods such as gravure printing and microcontact printing.

[0210] The materials used for the functional layers constituting the light-emitting device are not limited to the materials described above. For example, As materials for the functional layer, polymer compounds (oligomers, dendrimers, polymers, etc.), intermediate Sub-compounds (compounds in the intermediate region between low molecular weight and high molecular weight: molecular weight 400 to 4000), inorganic compounds Materials (such as quantum dot materials) may be used. Note that the quantum dot material may be colloidal. Quantum dot materials, alloy-type quantum dot materials, core-shell type quantum dot materials, core-type quantum dots Materials such as batting can be used.

[0211] [Light emission models in light-emitting devices] Regarding the light emission model in the light-emitting device that can be used in the display device of this embodiment explain.

[0212] Here, the hole transport layer 122, light-emitting layer 123, and electron transport layer 124 shown in Figure 4A are used. Next, we will explain the light emission model of the light-emitting device. The light-emitting device is not limited to the configuration shown in Figure 4A. This light emission model can also be applied to other configurations.

[0213] When the light-emitting layer 123 becomes electron-rich, as shown in Figure 5A, localized electron emission occurs within the light-emitting layer 123. A light-emitting region 123-1 is formed in the region. In other words, a light-emitting region within the light-emitting layer 123 The width of region 123-1 is narrow. Therefore, in a localized area of ​​the light-emitting layer 123, electricity is concentrated. Child (e - ) and hall (h + Recombination with ) occurs, accelerating degradation. Also, light emission Electrons that could not recombine in layer 123 pass through the light-emitting layer 123, thus shortening their lifetime. Alternatively, the luminous efficiency may decrease.

[0214] On the other hand, in a light-emitting device according to one aspect of the present invention, the electron transportability in the electron transport layer 124 is reduced. By doing so, the width of the light-emitting region 123-1 in the light-emitting layer 123 can be widened. (Figures 5B, 5C). By widening the width of the light-emitting region 123-1, the light-emitting layer 123 The recombination region between electrons and holes can be dispersed. Therefore, the lifetime and luminescence effect are long. We can provide light-emitting devices with good efficiency.

[0215] As shown in Figure 5B, in the initial stage of operation, the light-emitting device according to one aspect of the present invention has a recombination region In some cases, this can spread to the electron transport layer 124. Figure 5B shows the recombination in the electron transport layer 124. The region is shown as region 124-1. Specifically, in a light-emitting device according to one embodiment of the present invention, In the initial stages of operation, the hole injection barrier is small, and the electron transport properties of the electron transport layer 124 are relatively Due to the low temperature, the light-emitting region 123-1 (i.e., the recombination region) is formed throughout the entire light-emitting layer 123. Furthermore, a recombination region may also be formed in the electron transport layer 124.

[0216] Furthermore, the HOMO level of the third organic compound contained in the electron transport layer 124 is -6.0 eV or higher. Because the temperature is relatively high, some of the holes reach the electron transport layer 124, and even in the electron transport layer 124... Recombination may occur. This phenomenon is due to the host material contained in the light-emitting layer 123 ( The difference in HOMO levels between the assisting material and the third organic compound is within 0.2 eV. It can also happen in other cases.

[0217] As shown in Figure 5C, the light-emitting device according to one aspect of the present invention, as the operating time elapses... This changes the carrier balance, making recombination in the electron transport layer 124 less likely. The light-emitting region 123-1 remains formed throughout 123, while recombination in the electron transport layer 124 is suppressed. This allows the energy of the recombined carriers to be effectively contributed to luminescence. Yes, it is possible. Therefore, the brightness may increase compared to the initial stage of operation. This increase in brightness affects the light-emitting device. By offsetting the sudden decrease in brightness that occurs at the beginning of operation, known as initial degradation, the initial degradation is minimized. Furthermore, it is possible to provide a light-emitting device with a long operating life. The light-emitting device of Recombination-Site Tailoring Inj This is sometimes referred to as the ection structure (ReSTI structure).

[0218] Here, using Figure 5D, the light-emitting device of this embodiment and a comparative light-emitting device... This explains the normalized brightness over time. In Figure 5D, the thick solid line and the thick dashed line are This is the degradation curve of the normalized brightness of the light-emitting device of this embodiment, with the thick dashed line being a comparison curve. This is the degradation curve of the normalized brightness of an optical device.

[0219] As shown in Figure 5D, the light-emitting device of this embodiment and the light-emitting device for comparison are standard The slopes of the degradation curves of the luminance are different from each other. Specifically, the degradation of the light-emitting device in this embodiment The slope θ2 of the degradation curve is smaller than the slope θ1 of the degradation curve of the comparative light-emitting device.

[0220] As shown in Figure 5D, a light-emitting device according to one aspect of the present invention is a drive under the condition of constant current density In the luminance degradation curve obtained by dynamic testing, there may be a maximum value (thick solid line). ). In other words, the light-emitting device according to one aspect of the present invention is such that the brightness increases over time. It may exhibit movement. This behavior compensates for the rapid deterioration during the initial stages of operation (so-called initial deterioration). This is possible. However, the light-emitting device according to one aspect of the present invention is not limited to the above, for example, As shown by the thick dashed line in Figure 5D, there is no maximum value of luminance; in other words, luminance increase. The slope of the degradation curve can be reduced without causing any degradation. Therefore, the light-emitting device can be used By adopting a configuration that exhibits this behavior, the initial degradation of the light-emitting device is reduced, and the operating life is extended. It can always be made longer.

[0221] Furthermore, when the derivative of the degradation curve with a maximum value is taken, there is a region where the value is zero. Therefore, Therefore, a light-emitting device in which a portion of the derivative of the degradation curve is zero is described in one embodiment of the present invention. It can be rephrased as "vice."

[0222] In a light-emitting device according to one aspect of the present invention, the electron transport layer 124 has a third in the thickness direction. It is preferable that the mixture has a portion where the mixing ratio (concentration) of the organic compound and the first substance is different. In terms of structure, a mixture of an electron-transporting material and a metal, metal salt, metal oxide, or organometallic salt. It is preferable to have portions with different ratios (concentrations).

[0223] The concentration of the first substance in the electron transport layer 124 is determined by time-of-flight secondary ion mass spectrometry (To F-SIMS:Time-of-flight secondary ion mass This can be inferred from the amount of atoms or molecules detected by spectrometry. In parts composed of different types of materials with varying mixing ratios, ToF-SIMS analysis was performed. The magnitude of the detected values ​​corresponds to the relative abundance of the atoms or molecules of interest. Therefore, by comparing the detection amounts of electron transport materials and organometallic complexes, the large mixing ratio can be determined. You can get a rough estimate.

[0224] The content of the first substance in the electron transport layer 124 is higher on the cathode 102 side compared to the anode 101 side. It is preferable that the amount is less. In other words, the concentration of the first substance is less from the cathode 102 side to the anode 10 It is preferable that the electron transport layer 124 is formed so as to rise toward side 1. Furthermore, the electron transport layer 124 is located on the side of the light-emitting layer 123 that has a higher concentration of the third organic compound than the region where the concentration of the third organic compound is higher. It has a region with a low concentration of the first organic compound. In other words, the electron transport layer 124 has a region with a low concentration of the first organic compound. The region has a higher concentration of the first substance on the side of the light-emitting layer 123 than the region with a lower concentration of the substance.

[0225] In the electron transport layer 124, there is a region where the concentration of the third organic compound is high (where the concentration of the first substance is low). The electron mobility in the (i) region is 1 × 1 when the square root of the electric field strength [V / cm] is 600. 0 -7 cm 2 / Vs or more 5×10 -5 cm 2 It is preferable that it is less than or equal to / Vs.

[0226] For example, the content (concentration) of the first substance in the electron transport layer 124 is shown in Figures 6A to 6D. This configuration can be achieved. Note that Figures 6A and 6B show a clear boundary within the electron transport layer 124. Figure 6C and Figure 6D show the case where there is no boundary, and Figure 6D shows the case where there is a clear boundary within the electron transport layer 124. They are doing it.

[0227] If there is no clear boundary within the electron transport layer 124, the concentrations of the third organic compound and the first substance are As shown in Figures 6A and 6B, it changes continuously. Also, there is a clear boundary within the electron transport layer 124. If a boundary exists, the concentrations of the third organic compound and the first substance are as shown in Figures 6C and 6D. The concentration changes in a stepwise manner. In summary, it is suggested that the electron transport layer 124 is composed of multiple layers. For example, Figure 6C This represents the case where the electron transport layer 124 has a two-layer stacked structure, and Figure 6D shows the electron transport layer 124 This shows the case where it has a three-layer laminated structure. Note that in Figures 6C and 6D, the dashed lines represent multiple layers. It represents the boundary region.

[0228] In one embodiment of the present invention, a change in the carrier balance in the light-emitting device is due to the electron transport layer 124 This is thought to be caused by a change in electron mobility.

[0229] In one embodiment of the present invention, a light-emitting device exists in which a concentration difference of the first substance exists within the electron transport layer 124. The electron transport layer 124 is located between the region where the concentration of the first substance is low and the light-emitting layer 123. It has a region where the concentration of the first substance is high. That is, it has a region where the concentration of the first substance is low. It has a configuration that is located on the cathode 102 side of the region.

[0230] A light-emitting device according to one embodiment of the present invention, having the above configuration, has a very long lifespan. In particular, If the initial brightness is set to 100%, the time it takes for the brightness to reach 95% (also called LT95) is... It can be made extremely long.

[0231] Below, using Figures 7 to 9, we will describe in more detail the configuration of a display device according to one embodiment of the present invention. explain.

[0232] [Display device 100A] Figure 7 shows a perspective view of the display device 100A, and Figure 8A shows a cross-sectional view of the display device 100A. .

[0233] The display device 100A has a configuration in which substrate 152 and substrate 151 are bonded together. (See Figure 7) The circuit board 152 is clearly indicated by a dashed line.

[0234] The display device 100A includes a display unit 162, a circuit 164, wiring 165, etc. Figure 7 shows the display This shows an example in which IC (integrated circuit) 173 and FPC 172 are mounted on device 100A. Therefore, the configuration shown in Figure 7 is a display module having a display device 100A, an IC, and an FPC. It can also be called a joule.

[0235] For example, a scan line drive circuit can be used as circuit 164.

[0236] The wiring 165 has the function of supplying signals and power to the display unit 162 and the circuit 164. The signal and power are supplied externally via FPC172 or from IC173 to wiring 165. It will be entered.

[0237] Figure 7 shows the COG (Chip On Glass) method or COF (Chip on An example is shown in which IC173 is provided on substrate 151 using a film method, etc. For example, ICs having a scan line drive circuit or a signal line drive circuit can be applied to 3. The display device 100A and the display module may be configured without an IC. C may be implemented on the FPC using the COF method or similar.

[0238] Figure 8A shows a portion of the area of ​​the display device 100A including the FPC 172, a portion of the circuit 164, and a table. An example of a cross-section obtained by cutting a part of the indicated portion 162 and a part of the region including the end portion. show.

[0239] The display device 100A shown in Figure 8A has a transistor 201 between substrate 151 and substrate 152. , transistor 205, light-emitting device 190R, light-emitting device 190G, and light-emitting device It has S190B, etc.

[0240] The protective layer 195 and the substrate 152 are bonded together via the adhesive layer 142. Light-emitting device 190 For sealing, solid sealing structures or hollow sealing structures can be applied. In Figure 8A, substrate 15 2. The space 143 surrounded by the adhesive layer 142 and the substrate 151 is filled with an inert gas (nitrogen or algonium). It is filled with (such as n) and a hollow sealing structure is applied. The adhesive layer 142 is a light-emitting device It may be installed overlapping with the chair 190. Also, the substrate 152, adhesive layer 142, and substrate The space 143 surrounded by 151 may be filled with a resin different from the adhesive layer 142.

[0241] The light-emitting device 190R consists of a pixel electrode 191, an optical adjustment layer 199R, and a common light-emitting device 190R, starting from the insulating layer 214 side. A laminate is constructed by stacking the through layer 112, the light-emitting layer 193R, the common layer 114, and the common electrode 115 in that order. It has a structure. Similarly, the light-emitting device 190G has a pixel electrode 191 from the insulating layer 214 side, Optical adjustment layer 199G, common layer 112, light-emitting layer 193G, common layer 114, and common electrode 11 It has a stacked structure in the order of 5. The light-emitting device 190B has an insulating layer 214 From the side: pixel electrode 191, optical adjustment layer 199B, common layer 112, light-emitting layer 193B, common layer 1 It has a laminated structure in which 14 and the common electrode 115 are stacked in that order.

[0242] The pixel electrode 191 is connected to the transistor 205 through an opening provided in the insulating layer 214. It is connected to the conductive layer 222b.

[0243] The ends of the pixel electrode 191 are covered by a partition wall 216. The pixel electrode 191 receives visible light. The common electrode 115 contains a material that transmits visible light, and the reflective material is included.

[0244] The light emitted by the light-emitting device 190 is emitted towards the substrate 152. Visible light is emitted from the substrate 152. It is preferable to use a material with high permeability to [the substance].

[0245] Both transistors 201 and 205 are formed on the substrate 151. These transistors can be manufactured using the same materials and processes.

[0246] On the substrate 151, there are insulating layers 211, 213, 215, and 214. They are arranged in the following order. A portion of the insulating layer 211 serves as the gate insulating layer for each transistor. It functions as follows: The insulating layer 213, a portion of which functions as the gate insulating layer for each transistor. The insulating layer 215 is provided covering the transistor. The insulating layer 214 is provided covering the transistor. It is provided as a covering and has the function of a planarization layer. Note that the number of gate insulating layers and transient The number of insulating layers covering the sta is not limited; each layer may be a single layer or two or more layers.

[0247] At least one layer of the insulating layer covering the transistor is made of a material that does not easily diffuse impurities such as water and hydrogen. It is preferable to use a material. This allows the insulating layer to function as a barrier layer. This configuration effectively prevents impurities from diffusing into the transistor from the outside. This allows for effective suppression and improves the reliability of the display device.

[0248] Insulating layers 211, 213, and 215 are each made of inorganic insulating films. It is preferable to do so. Examples of inorganic insulating films include silicon nitride films and silicon oxide nitride films. silicon oxide film, silicon nitride film, aluminum oxide film, aluminum nitride film, etc. It can also be used. In addition, hafnium oxide film, yttrium oxide film, zirconium oxide Calcium oxide film, gallium oxide film, tantalum oxide film, magnesium oxide film, lanthanum oxide film, cereal oxide film A lium film and a neodymium oxide film may also be used. In addition, two or more of the above insulating films may be laminated. You may use it.

[0249] Here, organic insulating films often have lower barrier properties compared to inorganic insulating films. Therefore, organic The insulating film preferably has an opening near the edge of the display device 100A. This allows the display to be displayed. This prevents impurities from entering through the organic insulating film from the end of the device 100A. Alternatively, the edge of the organic insulating film can be positioned inward from the edge of the display device 100A. An insulating film may be formed so that the organic insulating film is not exposed at the edges of the display device 100A.

[0250] An organic insulating film is preferred for the insulating layer 214, which functions as a planarizing layer. Materials that can be used include acrylic resin, polyimide resin, epoxy resin, and polyam resins, polyimideamide resins, siloxane resins, benzocyclobutene resins, phenol Examples include resins and precursors of these resins.

[0251] In the region 228 shown in Figure 8A, an opening is formed in the insulating layer 214. This provides insulation Even when an organic insulating film is used for layer 214, the display unit 1 can be accessed from the outside via the insulating layer 214. This prevents impurities from entering 62. Therefore, it improves the reliability of the display device 100A. It is possible.

[0252] Transistors 201 and 205 have a conductive layer 221 that functions as a gate, An insulating layer 211 that functions as an insulating layer, and conductive layers 22 that function as source and drain. 2a and conductive layer 222b, semiconductor layer 231, insulating layer 213 which functions as a gate insulating layer, Furthermore, it has a conductive layer 223 that functions as a gate. Here, the same conductive film is processed Multiple layers obtained are given the same hatching pattern. The insulating layer 211 is a conductive layer It is located between 221 and semiconductor layer 231. The insulating layer 213 is located between the conductive layer 223 and semiconductor layer 2 It is located between 31 and 31.

[0253] The structure of the transistor in the light-emitting device of this embodiment is not particularly limited. For example, Uses na-type transistors, staggered transistors, inverse staggered transistors, etc. It is possible to do this. Also, either top-gate or bottom-gate transistor structure Alternatively, gates may be provided above and below the semiconductor layer in which the channel is formed. That's good too.

[0254] Transistors 201 and 205 have two semiconductor layers in which the channel is formed. A configuration is applied in which the gates are sandwiched together. Two gates are connected and the same signal is passed to them. The transistor may be driven by supplying a signal. Alternatively, one of the two gates By applying a potential to control the threshold voltage to one side and a potential to drive the other side, The threshold voltage of the transistor may be controlled.

[0255] The crystallinity of semiconductor materials used in transistors is not particularly limited; amorphous semiconductors, Semiconductors with crystalline properties (microcrystalline semiconductors, polycrystalline semiconductors, single-crystal semiconductors, or those with a crystalline region in part) Any semiconductor (having a region) may be used. If a semiconductor with crystalline properties is used, This is preferable because it suppresses the degradation of the DISTA characteristics.

[0256] The semiconductor layer of a transistor preferably contains a metal oxide (also called an oxide semiconductor). i. In other words, the display device of this embodiment uses a metal oxide in the channel formation region It is preferable to use a zista (hereinafter referred to as an OS transistor). Alternatively, half of a transistor The conductive layer may contain silicon. Examples of silicon include amorphous silicon, and Examples include crystalline silicon (low-temperature polysilicon, single-crystal silicon, etc.).

[0257] The semiconductor layer is, for example, made of indium and M (where M is gallium, aluminum, silicon, and chlorine). Calcium, yttrium, tin, copper, vanadium, beryllium, titanium, iron, nickel, gel Manium, Zirconium, Molybdenum, Lanthanum, Cerium, Neodymium, Hafnium, Ta (One or more selected from tungsten, magnesium, and zinc) It is preferable that it has the following. In particular, M is aluminum, gallium, yttrium, and s It is preferable that it be one or more types selected from the group.

[0258] In particular, the semiconductor layer contains indium (In), gallium (Ga), and zinc (Zn). It is preferable to use an oxide (also written as IGZO).

[0259] If the semiconductor layer is an In-M-Zn oxide, then the atoms of In in the In-M-Zn oxide... The numerical ratio is preferably greater than or equal to the atomic ratio of M. As for the atomic ratio of elements, In:M:Zn = 1:1:1 or close to it, In:M: Zn=1:1:1.2 or near that composition, In:M:Zn=2:1:3 or near that composition Nearby compositions: In:M:Zn=3:1:2 or compositions in the vicinity: In:M:Zn=4:2 :3 or a composition in its vicinity, In:M:Zn=4:2:4.1 or a composition in its vicinity, I n:M:Zn=5:1:3 or a similar composition, In:M:Zn=5:1:6 or something else Compositions in the vicinity of In:M:Zn=5:1:7 or in the vicinity of In:M:Zn=5 :1:8 or a composition close to it, In:M:Zn=6:1:6 or a composition close to it, I Compositions such as n:M:Zn=5:2:5 or nearby compositions are examples. This includes a range of ±30% of the desired atomic ratio.

[0260] For example, when describing the composition as having an atomic ratio of In:Ga:Zn = 4:2:3 or close to it. When the atomic ratio of In is 4, the atomic ratio of Ga is 1 or more and 3 or less, and the atomic number of Zn This includes cases where the ratio is between 2 and 4. Also, the atomic ratio is In:Ga:Zn = 5:1:6. When describing the composition in its vicinity, if the atomic ratio of In is 5, then the atomic ratio of Ga This includes cases where the value is greater than 0.1 and less than or equal to 2, and the atomic ratio of Zn is between 5 and 7. Furthermore, when describing a composition with an atomic ratio of In:Ga:Zn = 1:1:1 or close to it, I When the atomic ratio of n is set to 1, the atomic ratio of Ga is greater than 0.1 and less than or equal to 2, and Zn This includes cases where the atomic ratio is greater than 0.1 and less than or equal to 2.

[0261] The transistors in circuit 164 and the transistors in display unit 162 have the same structure. It may be present, or it may have a different structure. The structure of the multiple transistors in circuit 164 The construction may be the same for all, or there may be two or more types. Similarly, the display unit 162 has The structures of the multiple transistors may all be the same, or there may be two or more different structures.

[0262] A connection portion 204 is provided in the area of ​​substrate 151 where substrate 152 does not overlap. In section 204, the wiring 165 is electrically connected to the FPC 172 via the conductive layer 166 and the connecting layer 242. They are precisely connected. The conductive layer 166 is obtained by processing the same conductive film as the pixel electrode 191. The structure is a laminated structure of a conductive film and a conductive film obtained by processing the same conductive film as the optical adjustment layer. An example is shown. On the upper surface of the connection part 204, the conductive layer 166 is exposed. As a result, the connection part 204 and FPC172 can be electrically connected via the connecting layer 242.

[0263] It is preferable to provide a light-shielding layer BM on the surface of substrate 152 that faces substrate 151. Various optical components can be placed outside of 52. These optical components include polarizers and phase plates. Examples include a separator plate, a light diffusion layer (such as a diffusion film), an anti-reflective layer, and a light-concentrating film. Furthermore, the outside of the substrate 152 has an antistatic film to suppress the adhesion of dust, and a coating to make it difficult for dirt to adhere. It features a water-repellent film, a hard coat film to suppress scratches that occur during use, and an impact-absorbing layer. That's good too.

[0264] By providing a protective layer 195 that covers the light-emitting device 190, water and other substances can be prevented from reaching the light-emitting device 190. This suppresses the intrusion of impurities and improves the reliability of the light-emitting device 190.

[0265] In the region 228 near the end of the display device 100A, through the opening of the insulating layer 214, It is preferable that layer 215 and protective layer 195 are in contact with each other. In particular, the insulating layer 215 has It is preferable that the inorganic insulating film and the inorganic insulating film of the protective layer 195 are in contact with each other. This further suppresses the entry of impurities into the display unit 162 from the outside via the organic insulating film. This is possible. Therefore, the reliability of the display device 100A can be improved.

[0266] Figure 8B shows an example where the protective layer 195 has a three-layer structure. In Figure 8B, the protective layer 195 is: An inorganic insulating layer 195a on the common electrode 115, and an organic insulating layer 195b on the inorganic insulating layer 195a. It has an inorganic insulating layer 195c on an organic insulating layer 195b.

[0267] The edges of inorganic insulating layer 195a and inorganic insulating layer 195c are connected to the edges of organic insulating layer 195b. It extends outward and is in contact with each other. And the inorganic insulating layer 195a is insulating layer 214( The insulating layer (organic insulating layer) comes into contact with the insulating layer 215 (inorganic insulating layer) through an opening in the organic insulating layer. This provides insulation. The light-emitting device 190 can be surrounded by layer 215 and protective layer 195, so the light-emitting device This can improve the reliability of the S190.

[0268] Thus, the protective layer 195 may have a laminated structure of an organic insulating film and an inorganic insulating film. In this case, it is preferable that the edge of the inorganic insulating film extends outward more than the edge of the organic insulating film.

[0269] Substrates 151 and 152 are made of glass, quartz, ceramic, sapphire, and resin, respectively. Oils and other substances can be used. Flexible materials are used for substrates 151 and 152. This increases the flexibility of the display device.

[0270] The adhesive layer can be a photocuring adhesive such as an ultraviolet-curing type, a reaction-curing adhesive, or a thermosetting adhesive. Various types of curing adhesives, such as anaerobic adhesives, can be used. Poxy resin, acrylic resin, silicone resin, phenolic resin, polyimide resin, imide Resin, PVC (polyvinyl chloride) resin, PVB (polyvinyl butyral) resin, EV Examples include A (ethylene vinyl acetate) resin. In particular, epoxy resins have high moisture permeability. Low-cost materials are preferred. A two-part resin mixture may also be used. Furthermore, adhesive sheets, etc., may be used. It's okay to be there.

[0271] The connecting layer 242 is an anisotropic conductive film (ACF). (ductive film), anisotropic conductive paste (ACP: Anisotropic You can use methods such as Conductive Paste.

[0272] The light-emitting device 190 is a top-emission type, bottom-emission type, dual-emission type. There are various types, such as the ion type. A conductive film that transmits visible light is used for the electrode that extracts the light. Furthermore, it is preferable to use a conductive film that reflects visible light on the electrode that does not extract light.

[0273] The light-emitting device 190 has at least a light-emitting layer 193. Other layers besides 193 include materials with high hole injection potential, materials with high hole transport potential, and hole block materials. Materials, substances with high electron transport properties, substances with high electron injection properties, or bipolar substances (electron transport It may further have layers containing substances with high transportability and hole transportability. For example, a common layer. 112 preferably has one or both of a hole injection layer and a hole transport layer. For example, The common layer 114 preferably has one or both of the electron transport layer and the electron injection layer.

[0274] The preferred configuration of the light-emitting device 190 is as described above (Figures 4 to 6).

[0275] The common layer 112, the light-emitting layer 193, and the common layer 114 contain low molecular weight compounds and high molecular weight compounds. Either of these can be used, and may contain inorganic compounds. Common layer 112, light-emitting layer 1 Layers 93 and the common layer 114 are each created by a vapor deposition method (including vacuum deposition) and a transfer method, respectively. It can be formed by methods such as printing, inkjet printing, coating, etc.

[0276] The light-emitting layer 193 is a layer containing light-emitting material. The light-emitting layer 193 contains one or more types of light-emitting materials. It can possess qualities. Examples of luminescent materials include blue, purple, bluish-purple, green, yellowish-green, and yellow. Substances that emit light in colors such as orange or red are used as appropriate.

[0277] In addition to the gate, source, and drain of a transistor, various wirings and electrical components that make up the display device. Materials that can be used for conductive layers such as electrodes include aluminum, titanium, chromium, and nickel. Copper, copper, yttrium, zirconium, molybdenum, silver, tantalum, and tungsten Examples include metals such as tungsten, and alloys in which such metals are the main component. The film containing the material can be used as a single layer or as a multilayer structure.

[0278] Furthermore, examples of conductive materials that are translucent include indium oxide, indium tin oxide, and indium Conductive oxides or graphite such as zinc oxide, zinc oxide, and zinc oxide containing gallium You can use gold, silver, platinum, magnesium, nickel, or tungsten. Metal materials such as chromium, molybdenum, iron, cobalt, copper, palladium, and titanium Alternatively, an alloy material containing the metal material can be used. Or, a nitride of the metal material (for example) For example, titanium nitride may be used. When using the above material, it is preferable to make it thin enough to be translucent. A multilayer film of silver and magnesium can be used as a conductive layer. For example, an alloy of silver and magnesium and an index Using a multilayer film of um-tin oxide is preferable because it can improve conductivity. These include conductive layers such as various wirings and electrodes that constitute the display device, and conductive layers of light-emitting devices. It can also be used as an electrochemical layer (a conductive layer that functions as a pixel electrode or common electrode).

[0279] Examples of insulating materials that can be used for each insulating layer include acrylic resin and epoxy resin. resins such as silicon oxide, silicon oxide nitride, silicon nitride, silicon oxide Examples include inorganic insulating materials such as aluminum.

[0280] [Display device 100B] Figure 9A shows a cross-sectional view of the display device 100B. A perspective view of the display device 100B is shown in Figure 9A. This is the same as 0A (Figure 7). Figure 9A shows the region of the display device 100B that includes the FPC 172. When a part of the circuit, a part of the circuit 164, and a part of the display unit 162 are cut, the cross-sections are Here is an example. In Figure 9A, among the display unit 162, in particular, the light-emitting device 1 that emits green light is shown. An example of a cross-section when a region containing 90G and the blue light-emitting device 190B is cut. This indicates.

[0281] The display device 100B shown in Figure 9A has a transistor 202 between substrate 153 and substrate 154. It includes a transistor 210, a light-emitting device 190G, and a light-emitting device 190B, etc.

[0282] The substrate 154 and the protective layer 195 are bonded together via an adhesive layer 142. The adhesive layer 142 is It is installed in overlapping place with light-emitting device 190G and light-emitting device 190B, and displays Device 100B employs a solid encapsulation structure.

[0283] The substrate 153 and the insulating layer 212 are bonded together by an adhesive layer 155.

[0284] The method for fabricating the display device 100B involves first creating an insulating layer 212, each transistor, and each light-emitting diode. A fabricated substrate equipped with a vise, etc., and a substrate 154 equipped with a light-shielding layer BM are bonded together by an adhesive layer 14 The substrates are bonded together by step 2. Then, the fabricated substrate is peeled off and substrate 153 is attached to the exposed surface. Then, each component formed on the fabricated substrate is transferred to substrate 153. It is preferable that each of the 54 components is flexible. This allows the display device 100B to be flexible. It can increase flexibility.

[0285] The insulating layer 212 is used in insulating layer 211, insulating layer 213, and insulating layer 215, respectively. An inorganic insulating film can be used.

[0286] The light-emitting device 190G consists of a pixel electrode 191, a common layer 112, and a light-emitting layer 1, from the insulating layer 214 side. It has a laminated structure in which 93G, a common layer 114, and a common electrode 115 are stacked in that order. The light-emitting device 190B consists of, from the insulating layer 214 side, a pixel electrode 191, a common layer 112, and a light-emitting layer. It has a laminated structure in which 193B, a common layer 114, and a common electrode 115 are stacked in that order.

[0287] The pixel electrode 191 is connected to the transistor 210 through an opening provided in the insulating layer 214. It is connected to the conductive layer 222b. The conductive layer 222b is connected to the insulating layer 215 and the insulating layer 225 It is connected to the low-resistance region 231n through an opening provided therein. Transistor 210 is It has a function to control the driving of the light-emitting device 190.

[0288] The ends of the pixel electrode 191 are covered by a partition wall 216. The pixel electrode 191 receives visible light. The common electrode 115 contains a material that transmits visible light, and the reflective material is included.

[0289] The light emitted by light-emitting devices 190G and 190B is emitted towards the substrate 154. It is preferable to use a material with high transmittance to visible light for the substrate 154.

[0290] Each light-emitting device's pixel electrode 191 can be manufactured using the same material and the same process. The common layer 112, common layer 114, and common electrode 115 are connected to the light-emitting device 190G. It is used in common with the optical device 190B. Each color light-emitting device has a structure of light-emitting layer 193. Except for the differences in composition, all can share the same structure.

[0291] A connection portion 204 is provided in the area of ​​the substrate 153 where the substrate 154 does not overlap. In section 204, the wiring 165 is electrically connected to the FPC 172 via the conductive layer 166 and the connecting layer 242. They are precisely connected. The conductive layer 166 is obtained by processing the same conductive film as the pixel electrode 191. This allows electrical connections between the connection part 204 and the FPC 172 via the connection layer 242. It can connect to

[0292] Transistors 202 and 210 have a conductive layer 221 that functions as a gate, An insulating layer 211 that functions as an insulating layer, a channel forming region 231i and a pair of low-resistance regions A semiconductor layer having region 231n, and a conductive layer 222 connected to one of a pair of low-resistance regions 231n. a. A conductive layer 222b connecting to the other of a pair of low-resistance regions 231n, and a gate insulating layer. An insulating layer 225 that can function, a conductive layer 223 that functions as a gate, and a covering for the conductive layer 223. It has an insulating layer 215. The insulating layer 211 is between the conductive layer 221 and the channel forming region 231i It is located in between. The insulating layer 225 is located between the conductive layer 223 and the channel-forming region 231i. do.

[0293] The conductive layer 222a and the conductive layer 222b are separated by openings provided in the insulating layer 215. It is connected to the low-resistance region 231n. Of the conductive layer 222a and conductive layer 222b, one is One acts as the source, and the other as the drain.

[0294] Figure 9A shows an example in which the insulating layer 225 covers the top and sides of the semiconductor layer. Conductive layer 222a and The conductive layer 222b is connected to the insulating layer 225 and the insulating layer 215 through openings provided in the insulating layer 225 and the insulating layer 215, respectively. It is then connected to the low-resistance region 231n.

[0295] On the other hand, in Figure 9B, the insulating layer 225 overlaps with the channel formation region 231i of the semiconductor layer 231. Therefore, it does not overlap with the low-resistance region 231n. For example, using the conductive layer 223 as a mask for the insulating layer 2 By processing 25, the structure shown in Figure 9B can be fabricated. In Figure 9B, the insulating layer 225 and An insulating layer 215 is provided covering the conductive layer 223, and the conductive layer 2 is provided through an opening in the insulating layer 215. 22a and the conductive layer 222b are each connected to the low-resistance region 231n. An insulating layer 218 covering the transistor may be provided.

[0296] As described above, by using a light-emitting device that suppresses initial degradation and has a very long operating life, This can improve the reliability of the light-emitting device.

[0297] This embodiment can be appropriately combined with other embodiments. Furthermore, this specification Furthermore, if multiple configuration examples are shown within a single embodiment, the configuration examples may be combined as appropriate. It is possible to do so.

[0298] (Embodiment 2) In this embodiment, a display device according to one aspect of the present invention will be described with reference to Figure 10.

[0299] Figure 10A shows a block diagram of a pixel. The pixels shown in Figure 10A are switching transistors. (Switching Tr), Driving Transistor (Driving Tr), Light Emitting Device In addition to the OLED display, it also has memory.

[0300] The memory is supplied with data_W. In addition to the display data Data, data D When ata_W is supplied to the pixel, the current flowing to the light-emitting device increases, and the display device The placement allows for the expression of high brightness.

[0301] A light-emitting device in a display device according to one aspect of the present invention is used to display data Data and data Da By driving based on ta_W, it is possible to make the light-emitting device emit light at high brightness. ru.

[0302] Figure 10B shows a specific circuit diagram of the pixel circuit.

[0303] The pixels shown in Figure 10B are transistors M1, M2, M3, and It has an inverter M4, a capacitor Cs, a capacitor Cw, and a light-emitting device EL.

[0304] Either the source or drain of transistor M1 is electrically connected to one electrode of capacitor Cw. The other electrode of capacitance Cw is connected to either the source or drain of transistor M4. Electrically connected. Either the source or drain of transistor M4 is connected to the transistor The gate of transistor M2 is electrically connected to one side of the capacitance Cs. It is electrically connected to the electrode. The other electrode of capacitance Cs is the source or dot of transistor M2. It is electrically connected to one side of the rain. One side of the source or drain of transistor M2 is It is electrically connected to either the source or drain of transistor M3. Either the source or drain of M3 is electrically connected to one electrode of the light-emitting device EL. Each transistor shown in Figure 10B has a gate and a back gate that are electrically connected. However, the connection of the back gate is not limited to this. Also, the back gate of the transistor It is not necessary to provide it.

[0305] Here, the other electrode of capacitance Cw, one of the source or drain of transistor M4, The node to which the gate of the inverter M2 and one of the electrodes of the capacitance Cs are connected is designated as node NM. Also, the other electrode of capacitance Cs, the source or drain of transistor M2, One of the electrodes of the lampistor M3 (source or drain) and one of the electrodes of the light-emitting device EL are in contact. The next node will be designated as node NA.

[0306] The gate of transistor M1 is electrically connected to wiring G1. The gate of transistor M3 The gate of transistor M4 is electrically connected to wiring G1. The gate of transistor M4 is electrically connected to wiring G2. It is connected to the source or drain of transistor M1, the other being wired DATA and electrical. They are connected. The source or drain of transistor M3 is electrically connected to wiring V0. The source or drain of transistor M4 is connected to the wiring DATA_W. It is electrically connected.

[0307] The source or drain of transistor M2 is connected to the wiring ANODE (high potential side) and the electrical They are connected. The other electrode of the light-emitting device EL is connected to the wiring CATHODE (low potential side) and It is electrically connected.

[0308] Wires G1 and G2 function as signal lines to control the operation of the transistor. It is possible. The wiring DATA functions as a signal line that supplies image signals to the pixels. It is possible. Wiring DATA_W is a signal for writing data to the memory circuit MEM. It can function as a line. Wiring DATA_W supplies a correction signal to the pixel. It can function as a signal line. Wiring V0 controls the electrical characteristics of transistor M4. It functions as a monitoring line for acquiring data. Also, the wiring V0 leads to transistor M3. By supplying a specific potential to the other electrode of the capacitance Cs via this, the image signal is written. It can also be stabilized.

[0309] Transistors M2 and M4, and capacitor Cw constitute the memory circuit MEM. Node NM is a memory node, and by making transistor M4 conductive, wiring DATA_W The signal supplied to node NM can be written to it. Transistor M4 is extremely off. By using a low-current transistor, the potential of node NM can be maintained for a long time. ru.

[0310] Transistor M4 is, for example, a transistor that uses a metal oxide in the channel formation region. OS transistors can be used. This allows the off-current of transistor M4 to be It can be made extremely low, and the potential of node NM can be maintained for a long time. Furthermore, it is preferable to use OS transistors for the other transistors that make up the pixels. For specific examples of metal oxides, please refer to Embodiment 1.

[0311] OS transistors exhibit extremely low off-current characteristics due to their large energy gap. Furthermore, OS transistors exhibit impact ionization, avalanche breakdown, and short-channel efficiency. A transistor having Si in the channel formation region, such as one in which no defects occur (hereinafter referred to as a Si transistor) It has different characteristics from a zista and can form a highly reliable circuit.

[0312] Alternatively, a Si transistor may be used for transistor M4. In this case, the pixels are configured. It is preferable to use Si transistors for the other transistors as well.

[0313] Si transistors include transistors with amorphous silicon and transistors with crystalline silicon Transistors with capacitors (typically low-temperature polysilicon), and transistors with single-crystal silicon Examples include transistors.

[0314] Furthermore, a single pixel may have both an OS transistor and a Si transistor. .

[0315] In a pixel, the signal written to node NM is the image signal supplied from wiring DATA. It is capacitively coupled and can be output to node NA. Note that transistor M1 is a pixel It can have a function to select [a certain option].

[0316] In other words, if the desired correction signal is stored in node NM, the supplied image signal will be corrected accordingly. A signal can be added. Note that the correction signal will be attenuated by elements in the transmission path. Therefore, it is preferable to generate the product while taking this attenuation into consideration.

[0317] By using image signals and correction signals to make a light-emitting device emit light, the electricity flowing through the light-emitting device is controlled. The current can be increased, allowing for the expression of high brightness. Since the voltage can be applied as the gate voltage of the drive transistor, the power consumption of the source driver can be reduced. It can be reduced.

[0318] This embodiment can be combined with other embodiments as appropriate.

[0319] (Embodiment 3) In this embodiment, the OS transistor described in the above embodiment can be used. This section explains metal oxides (also known as oxide semiconductors).

[0320] The metal oxide preferably contains at least indium or zinc. In particular, indium It is preferable that it also contains aluminum, gallium, and zinc. It is preferable that it contains thorium, tin, etc. Also, boron, silicon, titanium, Iron, nickel, germanium, zirconium, molybdenum, lanthanum, cerium, neodymium One of the following materials is selected from: luminous, hafnium, tantalum, tungsten, magnesium, cobalt, etc. It may contain one or more species.

[0321] <Classification of crystal structures> First, we will explain the classification of crystal structures in oxide semiconductors using Figure 11A. Figure 11A shows an oxide semiconductor, typically IGZO (a metal containing In, Ga, and Zn). This is a diagram illustrating the classification of the crystal structure of oxides.

[0322] As shown in Figure 11A, oxide semiconductors can be broadly classified into "Amorphous" It is divided into "Crystalline (crystalline)" and "Crystal (crystal)". They are classified as such. Also, among "Amorphous," there are completely amorp It includes hous. Also, within "Crystalline" there is CAAC(c-ax is-aligned crystalline), nc(nanocrystalli This includes ne), and CAC (cloud-aligned composite). Note that the classification of "Crystalline" includes single crystal, pol Y crystals and completely amorphous crystals are excluded. "Crystal" includes single crystal and poly cry It includes "stal".

[0323] The structures within the thick border shown in Figure 11A are "Amorphous" and "Cry It is an intermediate state between "stal (crystal)" and a new boundary region (New crystal This structure belongs to the line phase. In other words, this structure is energetically in It is completely different from the stable "Amorphous" or "Crystal" forms. This can be rephrased as a structure.

[0324] The crystal structure of the film or substrate is determined by X-ray diffraction (XRD). It can be evaluated using the (on) spectrum. Here, the quartz glass substrate and "Cr IGZO (also called crystalline IGZO) has a crystalline structure classified as "ystalline". XRD obtained by GIXD (Grazing-Incidence XRD) measurement of the membrane. The spectra are shown in Figures 11B and 11C, respectively. Note that the GIXD method is a thin-film method or Also known as the Seemann-Bohlin method. Hereafter, the GIXD measurement shown in Figures 11B and 11C will be used. The XRD spectrum obtained at a constant temperature is simply referred to as the XRD spectrum. Figure 11B shows quartz glass. Figure 11C shows the XRD spectrum of the substrate and the crystalline IGZO film. Note that the results shown in Figure 11C The composition of the crystalline IGZO film is approximately In:Ga:Zn = 4:2:3 [atomic ratio]. The thickness of the crystalline IGZO film shown in Figure 11C is 500 nm.

[0325] As shown by the arrow in Figure 11B, the shape of the XRD spectrum peaks in the quartz glass substrate is It is almost symmetrical. On the other hand, as shown by the arrow in Figure 11C, in the crystalline IGZO film, X The peak shape of the RD spectrum is asymmetrical. The peak shape of the XRD spectrum is The asymmetry clearly indicates the presence of crystals in the film or substrate. In other words, If the peak shape of the XRD spectrum is not symmetrical, the film or substrate is amorphous. That cannot be said. Furthermore, Figure 11C shows a crystalline phase (IGZO) at 2θ=31° or in its vicinity. The crystal phase is specified. The XRD spectrum is left-right asymmetric. The peaks with a uniform shape are presumed to originate from diffraction peaks due to the crystalline phase (tiny crystals). ru.

[0326] Specifically, the interference of X-rays scattered by atoms contained in IGZO is 2θ=34° or It is presumed to contribute to the nearby peak. Also, minute crystals have 2θ=31° or so It is presumed to contribute to the nearby peak. Figure 11C shows the XRD of a crystalline IGZO film. In the vector, at the peak of 2θ = 34° or nearby, the peak width on the lower angle side is wide. This is due to a peak in the crystalline IGZO film at or near 2θ=31°. This suggests the presence of minute crystals within the material.

[0327] Furthermore, the crystal structure of the film or substrate is determined by nano-beam diffraction (NBED). Diffraction patterns observed by electron diffraction (extremely low-voltage electrons) It can be evaluated using the sub-ray diffraction pattern (also called the sub-ray diffraction pattern). The quartz glass substrate and the substrate temperature... The diffraction patterns of IGZO films deposited at room temperature are shown in Figures 11D and 11E, respectively. Figure 11D shows the diffraction pattern of the quartz glass substrate, and Figure 11E shows the diffraction pattern of the IGZO film. Note that Figure 1 The IGZO film shown in 1E is an oxide film with an atomic ratio of In:Ga:Zn = 1:1:1. The film is deposited using sputtering with a GET. Furthermore, in micro-electron diffraction, Electron diffraction is performed with a probe diameter of 1 nm.

[0328] Furthermore, as shown in Figure 11D, a halo is observed in the diffraction pattern of the quartz glass substrate. It can be confirmed that the quartz glass is in an amorphous state. Also, as shown in Figure 11E, at room temperature In the diffraction pattern of the deposited IGZO film, a spot-like pattern was observed, rather than a halo. Therefore, the IGZO film deposited at room temperature is neither crystalline nor amorphous. Therefore, it is presumed that this is an intermediate state and cannot be concluded to be an amorphous state.

[0329] <<Oxide semiconductor structure>> Note that oxide semiconductors may be classified differently from those shown in Figure 11A when considering their crystal structure. Yes, there are. For example, oxide semiconductors include single-crystal oxide semiconductors and other non-single-crystal oxide semiconductors. It can be divided into two parts. Examples of non-single-crystal oxide semiconductors include the aforementioned CAAC-OS. And there is nc-OS. In addition, non-single-crystal oxide semiconductors include polycrystalline oxide semiconductors and pseudo-non-crystalline oxide semiconductors. crystalline oxide semiconductor (a-like OS: amorphous-like oxide) This includes semiconductors, amorphous oxide semiconductors, and so on.

[0330] Here, we will provide details on the CAAC-OS, nc-OS, and a-like OS mentioned above. Give an explanation.

[0331] [CAAC-OS] CAAC-OS has multiple crystalline regions, and these multiple crystalline regions are arranged with their c-axis in a specific direction. It is an oxide semiconductor that is oriented in a particular direction. Note that the specific direction refers to the thickness direction of the CAAC-OS film. The direction normal to the surface on which the CAAC-OS film is formed, or the direction normal to the surface of the CAAC-OS film. Furthermore, a crystalline region is a region in which the atomic arrangement has periodicity. If considered as an arrangement, a crystalline region is also a region with a aligned lattice arrangement. Furthermore, CAAC-O S has a region in the ab-plane direction where multiple crystalline regions are connected, and this region is strained. This can sometimes occur. Note that strain refers to the deformation of the lattice arrangement in a region where multiple crystal regions are connected. Areas where the orientation of the grid arrangement changes between aligned regions and aligned regions with a different grid arrangement. This refers to the fact that CAAC-OS is c-axis oriented and has a clear orientation in the ab-plane direction. It is an oxide semiconductor that does not exist.

[0332] Each of the above multiple crystalline regions is composed of one or more minute crystals (with a maximum diameter of 10n It is composed of crystals that are less than m in size. If the crystalline region is composed of one minute crystal, The maximum diameter of the crystalline region is less than 10 nm. Furthermore, the crystalline region is composed of numerous tiny crystals. If this is the case, the size of the crystalline region may be around several tens of nanometers.

[0333] In addition, In-M-Zn oxide (where M is aluminum, gallium, yttrium, and tin) In one or more types selected from titanium, etc., CAAC-OS is indigenous A layer containing ions (In) and oxygen (hereinafter referred to as the In layer), and an element M, zinc (Zn), and oxygen A layered crystalline structure (also called a layered structure) is formed by stacking layers containing (M,Zn) layers. ) tends to have. Furthermore, indium and element M are mutually substitutable. Therefore, The (M,Zn) layer may contain indium. Additionally, the In layer contains the element M. This may occur. Furthermore, the In layer may also contain Zn. This layered structure is, for example, High-resolution TEM (Transmission Electron Microscope) In the image, it is observed as a grid pattern.

[0334] When structural analysis of a CAAC-OS film is performed using, for example, an XRD instrument, the θ / 2θ skid is observed. Out-of-plane XRD measurements using a champ showed a peak indicating c-axis orientation at 2θ. It is detected at 31° or near that angle. Note that the position of the peak indicating c-axis orientation (value of 2θ) This may vary depending on the type and composition of the metal elements that make up CAAC-OS.

[0335] Furthermore, for example, in the electron diffraction pattern of a CAAC-OS film, multiple bright spots (spots) may be observed. ) is observed. Note that one spot and another spot are determined by the incident electron beam that has passed through the sample. Observed at a point-symmetric position with respect to the spot (also called a direct spot) as the center of symmetry. .

[0336] When the crystal region is observed from the specific direction described above, the lattice arrangement within that crystal region is a hexagonal lattice. While this is the basic principle, the unit cell is not necessarily a regular hexagon and may be a non-regular hexagon. Also, In the distortion described, there may be grid arrangements such as pentagons and heptagons. Note that CAAC- In OS, clear grain boundaries can be observed even near strain. It is not possible. In other words, the formation of grain boundaries is suppressed by the distortion of the lattice arrangement. This can be seen. This is because CAAC-OS has a dense arrangement of oxygen atoms in the ab-plane direction. Due to the absence of certain elements, or because the substitution of metal atoms changes the bond distance between atoms, This is thought to be because it allows for distortion to be tolerated.

[0337] Furthermore, a crystal structure in which clear grain boundaries can be observed is known as polycrystalline. It is called l). The grain boundaries become recombination centers, where carriers are trapped and the transistor is formed This is highly likely to cause a decrease in current, a decrease in field-effect mobility, etc. Therefore, a clear conclusion is reached. CAAC-OS, which lacks visible grain boundaries, has a crystal structure suitable for the semiconductor layer of transistors. It is one of the crystalline oxides. Note that CAAC-OS requires the presence of Zn. The configuration is preferable. For example, In-Zn oxide and In-Ga-Zn oxide are In oxide It is preferable because it can suppress the generation of grain boundaries more effectively than other materials.

[0338] CAAC-OS is an oxide semiconductor with high crystallinity and no clearly defined grain boundaries. Therefore, CAAC-OS is less prone to a decrease in electron mobility caused by grain boundaries. Furthermore, the crystallinity of oxide semiconductors can decrease due to impurities or the formation of defects. Therefore, CAAC-OS is also an oxide semiconductor with few impurities and defects (such as oxygen vacancies). Yes, that's correct. Therefore, oxide semiconductors containing CAAC-OS have stable physical properties. Therefore, oxide semiconductors containing CAAC-OS are highly heat-resistant and reliable. -OS is stable even at high temperatures (so-called thermal budget) during the manufacturing process. Therefore, using CAAC-OS in OS transistors expands the degree of freedom in the manufacturing process. This becomes possible.

[0339] [nc-OS] nc-OS is used in minute regions (for example, regions between 1 nm and 10 nm, especially between 1 nm and 3 nm). It has periodicity in the atomic arrangement in the region of less than nm. In other words, nc-OS is minute It has crystals. The size of these minute crystals is, for example, between 1 nm and 10 nm. In particular, because they are between 1 nm and 3 nm in size, these minute crystals are also called nanocrystals. In nc-OS, no regularity is observed in the crystal orientation between different nanocrystals. Therefore, across the entire film... No orientation is observed. Therefore, nc-OS is a-like OS depending on the analysis method. In some cases, it may be indistinguishable from amorphous oxide semiconductors. For example, XR When performing structural analysis using device D, an out-of-plane scan using θ / 2θ is performed. XRD measurements did not detect any peaks indicating crystallinity. Furthermore, for the nc-OS film, Electron diffraction (control) using an electron beam with a probe diameter larger than that of the crystal (e.g., 50 nm or more) Also called limited-field electron diffraction, when this is performed, a diffraction pattern similar to a halo pattern is observed. On the other hand, for nc-OS films, the particles are close in size to or smaller than the nanocrystals. Electron diffraction using electron beams with a diameter (e.g., 1 nm to 30 nm) (nanobeam electron beam) When diffraction is performed, multiple particles are found within a ring-shaped region centered on the direct spot. In some cases, electron diffraction patterns in which spots are observed can be obtained.

[0340] [a-like OS] a-like OS is an oxide semiconductor having a structure between nc-OS and amorphous oxide semiconductors. It is a conductor. a-like OS has porous or low-density regions. That is, a-like OS has lower crystallinity compared to nc-OS and CAAC-OS. Also, it has a-like properties. OS has a higher hydrogen concentration in the membrane compared to nc-OS and CAAC-OS.

[0341] <<Oxide Semiconductor Composition>> Next, we will explain the details of CAC-OS mentioned above. Note that CAC-OS is a material composition. Regarding.

[0342] [CAC-OS] CAC-OS refers to, for example, metal oxides in which the elements constituting the metal oxide are between 0.5 nm and 10 nm in size. Preferably, a composition of material that is unevenly distributed with a size of 1 nm to 3 nm or near that size. In addition, in the following, in a metal oxide, one or more metal elements are unevenly distributed, The region containing the metallic element is 0.5 nm to 10 nm, preferably 1 nm to 3 nm. The following state, where particles of similar or near-similar size are mixed, is also referred to as a mosaic or patchy appearance.

[0343] Furthermore, CAC-OS is a system where the material separates into a first region and a second region, resulting in a mosaic effect. This results in a cloud-like structure, where the first region is distributed within the membrane (hereinafter also referred to as a cloud-like structure). Therefore, CAC-OS is a mixture of the first region and the second region. It is a composite metal oxide having the following configuration.

[0344] Here, In for the metal elements constituting CAC-OS in In-Ga-Zn oxide The atomic ratios of , Ga, and Zn are denoted as [In], [Ga], and [Zn], respectively. For example, in CAC-OS in In-Ga-Zn oxide, the first region is [ This is the region where [In] is greater than [In] in the composition of the CAC-OS film. Also, the second This region is the region where [Ga] is greater than the [Ga] in the composition of the CAC-OS film. Alternatively, for example, in the first region, [In] is greater than [In] in the second region. Furthermore, the region where [Ga] is smaller than the region where [Ga] is smaller. In region 2, [Ga] is greater than [Ga] in region 1, and [In] is This is a region smaller than [In] in the first region.

[0345] Specifically, the first region mentioned above is mainly composed of indium oxide, indium zinc oxide, etc. This is the region. Furthermore, the second region mentioned above includes gallium oxide, gallium zinc oxide, etc. This is the region in which is the principal component. In other words, the first region described above is called the region in which In is the principal component. It can be replaced. Furthermore, the second region mentioned above can be rephrased as the region with Ga as the main component. It is possible.

[0346] Furthermore, a clear boundary may not be observed between the first region and the second region described above.

[0347] Furthermore, CAC-OS in In-Ga-Zn oxide refers to In, Ga, Zn, and O In the material composition, there is a region where Ga is the main component and a region where In is the main component. This refers to a configuration in which each region is mosaic-like, and these regions exist randomly. Therefore, it is presumed that CAC-OS has a structure in which metallic elements are unevenly distributed. .

[0348] CAC-OS is formed, for example, by sputtering under conditions where the substrate is not intentionally heated. It is possible. Also, when forming CAC-OS by sputtering, the deposition gas and Then, select from inert gases (typically argon), oxygen gas, and nitrogen gas. You can use one or more of these. Also, the oxygen gas in relation to the total flow rate of the deposition gas during film formation. A lower flow rate ratio of oxygen gas is preferable, for example, a lower ratio of oxygen gas to the total flow rate of the film deposition gas during film formation. The flow rate ratio is preferably 0% or more and less than 30%, more preferably 0% or more and 10% or less.

[0349] Furthermore, for example, in CAC-OS in In-Ga-Zn oxide, energy-dispersive X Linear spectroscopy (EDX: Energy Dispersive X-ray spectrometer) EDX mapping obtained using scopy revealed a region with In as its main component (1st A structure in which a region (the first region) and a region mainly composed of Ga (the second region) are unevenly distributed and mixed. It can be confirmed that they possess it.

[0350] Here, the first region is a region with higher conductivity compared to the second region. In other words, the first region The flow of carriers through this region causes the metal oxide to exhibit conductivity. Therefore The first region is distributed in a cloud-like manner within the metal oxide, resulting in a high field-effect mobility (μ This can be achieved.

[0351] On the other hand, the second region is a region with higher insulating properties compared to the first region. In other words, the second region By distributing the region within the metal oxide, leakage current can be suppressed.

[0352] Therefore, when CAC-OS is used in a transistor, the conductivity due to the first region and the second region The insulating properties originating from region 2 work complementaryly to create a switching function. (The function to turn it on / off) can be added to CAC-OS. In other words, CAC- OS refers to a material that has both conductive and insulating properties in some parts. The whole structure functions as a semiconductor. The conductive and insulating functions are separated. This allows both functions to be maximized. Therefore, CAC-OS is transistor By using it, a high on-current (I on ), high field effect mobility (μ), and good swim It can perform a clicking motion.

[0353] Furthermore, transistors using CAC-OS are highly reliable. Therefore, CAC-OS is, It is ideal for various semiconductor devices, including display devices.

[0354] Oxide semiconductors can take on diverse structures, each possessing different properties. One embodiment of the present invention Oxide semiconductors include amorphous oxide semiconductors, polycrystalline oxide semiconductors, a-like OS, and CA. It may have two or more of the following: C-OS, nc-OS, and CAAC-OS.

[0355] <Transistors containing oxide semiconductors> Next, we will explain the case where the above oxide semiconductor is used in a transistor.

[0356] By using the above oxide semiconductor in transistors, transistors with high field-effect mobility can be produced. It can be achieved. Furthermore, highly reliable transistors can be realized.

[0357] It is preferable to use an oxide semiconductor with a low carrier concentration for the transistor. For example, The carrier concentration of oxide semiconductors is 1 × 10⁻⁶ 17 cm -3 The following is preferably 1 × 10 15 cm -3 More preferably 1 × 10 13 cm -3 More preferably 1 × 10 11 c m -3 More preferably 1 × 10 10 cm -3 It is less than 1 × 10 -9 cm -3 That concludes the explanation. Furthermore, when lowering the carrier concentration of the oxide semiconductor film, The impurity concentration in the conductive film can be reduced to lower the defect level density. In this specification, High-purity intrinsic or substantially high-purity intrinsic refers to a product with a low impurity concentration and a low defect level density. Furthermore, oxide semiconductors with low carrier concentrations are subjected to high-purity intrinsic or substantially high-purity intrinsic oxidation. It is sometimes called a crystalline semiconductor.

[0358] Furthermore, oxide semiconductor films that are high-purity intrinsic or substantially high-purity intrinsic have a low defect level density. Therefore, the trap level density may also be low.

[0359] Furthermore, the time required for charges trapped in the trap levels of oxide semiconductors to disappear is long. Furthermore, it can behave as if it were a fixed charge. Therefore, it can behave as if it were a fixed charge. Transistors in which a channel formation region is formed in an oxide semiconductor exhibit unstable electrical properties. There are cases where this is the case.

[0360] Therefore, in order to stabilize the electrical characteristics of the transistor, the impurity concentration in the oxide semiconductor must be Reducing it is effective. Also, in order to reduce the impurity concentration in oxide semiconductors, It is also preferable to reduce the concentration of impurities in the contacting film. Examples of impurities include hydrogen, nitrogen, and aluminum. Examples include potash metals, alkaline earth metals, iron, nickel, and silicon.

[0361] <Impurities> Here, we will explain the effects of various impurities in oxide semiconductors.

[0362] In oxide semiconductors, if silicon or carbon, which are among the Group 14 elements, are present, the oxide Defect levels are formed in semiconductors. Therefore, silicon and carbon in oxide semiconductors. The concentration of silicon and carbon near the interface with the oxide semiconductor (by secondary ion mass spectrometry) SIMS (Secondary Ion Mass Spectrometry) The resulting concentration is 2 × 10 18 atoms / cm 3 The following is preferably 2 × 10 17 at oms / cm 3 The following applies:

[0363] Furthermore, if alkali metals or alkaline earth metals are present in the oxide semiconductor, defect levels are formed. And, it may generate carriers. Therefore, alkali metals or alkaline earth metals are included. Transistors using oxide semiconductors tend to exhibit normally-on characteristics. Therefore, the concentration of alkali metals or alkaline earth metals in oxide semiconductors obtained by SIMS. , 1 × 10 18 atoms / cm 3 The following is preferably 2 × 10 16 atoms / cm 3 Do the following:

[0364] Furthermore, in oxide semiconductors, when nitrogen is present, electrons, which are carriers, are generated. The concentration increases, making it easier to convert to n-type. As a result, oxide semiconductors containing nitrogen become semiconductors. The transistor used tends to exhibit normally-on characteristics. Alternatively, in oxide semiconductors... If nitrogen is present, a trap level may be formed. As a result, the transistor Electrical properties may become unstable. For this reason, in oxide semiconductors obtained by SIMS... The nitrogen concentration is 5 × 10 19 atoms / cm 3 Less than 5 × 10 18 Atom s / cm 3 More preferably 1 × 10 18 atoms / cm 3 More preferably, is 5 x 10 17 atoms / cm 3 Do the following:

[0365] Furthermore, the hydrogen contained in oxide semiconductors reacts with the oxygen bonded to the metal atoms to form water. This can sometimes form an oxygen vacancy. When hydrogen enters this oxygen vacancy, the electrons, which are carriers, In some cases, this can be generated. Also, some of the hydrogen combines with oxygen that is bonded to a metal atom, resulting in a It can generate electrons, which are rear electrons. Therefore, using an oxide semiconductor containing hydrogen... Transistors tend to exhibit normally-on characteristics. Therefore, hydrogen in oxide semiconductors It is preferable that it be reduced as much as possible. Specifically, in oxide semiconductors, SIM The hydrogen concentration obtained by S is 1 × 10 20 atoms / cm 3 Less than 1 × 1 0 19 atoms / cm 3 Less than 5x10 18 atoms / cm 3 less than, More preferably 1 × 10 18 atoms / cm 3 Make it less than.

[0366] Using oxide semiconductors with sufficiently reduced impurities in the channel formation region of transistors. This allows for the provision of stable electrical characteristics.

[0367] This embodiment can be combined with other embodiments as appropriate.

[0368] (Embodiment 4) In this embodiment, an electronic device according to one aspect of the present invention will be described with reference to Figures 12 to 17. ru.

[0369] The electronic device of this embodiment has a display device according to one aspect of the present invention in its display unit, and therefore has a long lifespan. Furthermore, by using a display device according to one embodiment of the present invention in the display unit, electronic devices This allows for a longer lifespan and a larger screen.

[0370] The display unit of the electronic device in this embodiment can display, for example, Full HD, 4K2K, 8K4K, It can display video with a resolution of 16K, 8K, or higher. The display screen sizes are 20 inches or larger diagonally, 30 inches or larger diagonally, and 50 inches diagonally. The diagonal size can be 60 inches or more, or 70 inches or more.

[0371] Examples of electronic devices include television equipment, desktop or notebook computers, etc. Sony Computer, monitors for computers, digital signage (Digita Signage: (Electronic billboards), large game machines such as pachinko machines, and other relatively large images. In addition to electronic devices equipped with a screen, digital cameras, digital video cameras, and digital photo frames are also available. Examples include mobile phones, portable game consoles, personal digital assistants, and audio playback devices.

[0372] The electronic device of this embodiment is installed in the interior or exterior walls of a house or building, or inside a car. It can be incorporated along the curved surface of the frame or exterior.

[0373] The electronic device of this embodiment may have an antenna. The antenna receives a signal. This allows the display unit to show images, information, etc. Also, the electronic equipment has an antenna and If a secondary battery is present, the antenna may be used for contactless power transmission.

[0374] The electronic device of this embodiment has sensors (force, displacement, position, velocity, acceleration, angular velocity, rotational speed, Distance, light, liquid, magnetism, temperature, chemicals, sound, time, hardness, electric field, electric current, voltage, power, radiation (including functions for measuring radiation, flow rate, humidity, gradient, vibration, odor, or infrared radiation) It's fine if you do that.

[0375] The electronic device of this embodiment can have various functions. For example, it can display various information (static Functions to display still images, videos, text images, etc. on the display unit, touch panel function, calendar - Functions to display the date or time, and to run various software (programs) Functions, wireless communication functions, and functions to read programs or data recorded on recording media. It may have the following:

[0376] The electronic device 6500 shown in Figure 12A is a portable information device that can be used as a smartphone. It is a terminal device.

[0377] The electronic device 6500 consists of a housing 6501, a display unit 6502, a power button 6503, and a button 65 04, includes speaker 6505, microphone 6506, camera 6507, and light source 6508, etc. The display unit 6502 is equipped with a touch panel function.

[0378] A display device according to one aspect of the present invention can be applied to the display unit 6502.

[0379] Figure 12B is a schematic cross-sectional view of the housing 6501, including the end on the microphone 6506 side.

[0380] A light-transmitting protective member 6510 is provided on the display surface side of the housing 6501. Within the space surrounded by the protective member 6510, there is a display panel 6511, an optical member 6512, and a touch The sensor panel 6513, printed circuit board 6517, battery 6518, etc. are located here. .

[0381] The protective member 6510 includes a display panel 6511, an optical member 6512, and a touch sensor panel. The 6513 is fixed by an adhesive layer (not shown).

[0382] In the area outside the display unit 6502, a portion of the display panel 6511 is folded back. The FPC6515 is connected to the folded portion. C6516 is mounted. FPC6515 is located on the edge of the printed circuit board 6517. It is connected to the child.

[0383] A flexible display device according to one aspect of the present invention can be applied to the display panel 6511. Therefore, it is possible to realize extremely lightweight electronic devices. Also, the display panel 6511 is extremely Because it is thin, it can accommodate a large-capacity 6518 battery while keeping the thickness of electronic devices down. Furthermore, a portion of the display panel 6511 is folded back, and the FPC 6515 is attached to the back of the pixel area. By positioning the connection points, it is possible to create electronic devices with narrow bezels.

[0384] Figures 13 to 15 show an electronic device having a flexible display device that can be folded into a small size. An example of a vessel is shown.

[0385] The electronic devices shown in Figures 13 and 14 have a folding mechanism so that the display surfaces face each other. It can be folded.

[0386] The electronic device shown in Figure 15 has a tri-fold mechanism, which folds so that the display surfaces face each other. There is an area where this can be done, and an area where it can be folded so that the side opposite the display surface faces the other side. It holds.

[0387] The electronic devices shown in Figures 13 to 15 have aspect ratios such as 16:9, 18:9, and 21:9. Even when a display device has a relatively large aspect ratio, by providing a fold in the short axis direction, It can be folded into a small size, improving the portability of electronic devices. By hiding the display area that is not visible when the device is folded into a small size, power consumption is reduced. It can be significantly reduced.

[0388] Figure 13A shows the electronic device 800A folded to its smallest size (by folding it in half). Yes. Figure 13B shows the electronic device 800B folded to its smallest size (in half). This is a diagram. Figure 13C shows the electronic device 800A or electronic device 800B in an unfolded state. This is a diagram.

[0389] Electronic equipment 800A and electronic equipment 800B each have a flexible display panel 801 a, housing 802a, housing 802b, and hinge 803 are included.

[0390] The display panel 801a uses a single, seamless, flexible display panel. Yes, it is possible. A display device according to one aspect of the present invention can be used for the display panel 801a.

[0391] With electronic device 800A or electronic device 800B deployed, display panel 801a This includes a first region 811a that overlaps with the housing 802a, and a second region 811 that overlaps with the hinge 803. b has a third area 811c that overlaps with the housing 802b. These three areas are the display panel It is preferable that it be included in the display area of ​​801a. Therefore, the first region 811a and the third region 811c overlap each other. Electronic device 80 When 0A and electronic equipment 800B are folded as shown in Figures 13A and 13B, the second As region 811b is curved, the first region 811a and the third region 811c The display surfaces face each other.

[0392] Enclosure 802a is connected to enclosure 802b via hinge 803.

[0393] At least a portion of the display panel 801a may be fixed to the housing 802a. At least a portion of the Nel 801a may be fixed to the housing 802b.

[0394] The electronic device 800B further includes a display panel 801b.

[0395] In the electronic device 800B, display panel 801a and display panel 801b are connected to the housing 802a. They overlap each other through a barrier. The display surface of display panel 801a and the display surface of display panel 801b are They are facing in opposite directions. The housing 802a has a display panel 801a fixed to the first surface. The display panel 801b may be fixed to a second surface facing the first surface. .

[0396] Either or both of the display panels 801a and 801b of the electronic device 800B A display device according to one aspect of the present invention can be used.

[0397] When the electronic device 800B is folded, the user can see the display on the display panel 801b. This is possible. When the electronic device 800B is deployed, the user can see the display on the display panel 801a. It can be seen.

[0398] Figure 14A shows the electronic device 800C folded to its smallest size (by folding it in half). Yes. Figure 14B shows the electronic device 800C in its unfolded state.

[0399] The electronic device 800C includes a flexible display panel 801, a housing 802a, a housing 802b, and has a hinge 803.

[0400] The display panel 801 can be a single, seamless, flexible display panel. A display device according to one embodiment of the present invention can be used for the display panel 801.

[0401] With the electronic device 800C unfolded, the display panel 801 is connected via the housing 802a. The first region 811a and the second region 811b overlap each other, and the first region 811a and the second region A third region 811c is located between regions 811b and has a curved surface, overlapping with the hinge 803. It has a fourth region 811d and a fifth region 811e that overlaps with the housing 802b. These five The region is preferably included in the display area of ​​the display panel 801. (See Figure 14A) In this region, the first region 811a, the second region 811b, and the fifth region 811e are relative to each other. They overlap. In the state shown in Figure 14A, the user is in the first region 811a and the third region The 811c display can be seen. In the state shown in Figure 14B, the user is in the second area Region 811b, the fourth region 811d, and the fifth region 811e (and also the third region 811 c) The display can be seen.

[0402] In the state shown in Figure 14A, the display surface in the first region 811a and the fifth region 811e is They are facing the same direction, and in the second region 811b, the display surface is facing the direction opposite to that direction. It is facing in the direction shown. When the electronic device 800C is folded as shown in Figure 14A, the second The display surfaces of region 811b and the fifth region 811e face each other.

[0403] Enclosure 802a is connected to enclosure 802b via hinge 803.

[0404] At least a portion of the display panel 801 may be fixed to the housing 802a. The 801 is the three consecutive surfaces of the housing 802a (the first surface, the second surface facing the first surface) It is provided along the third surface (side) between the first surface and the second surface. Display panel 801 The first region 811a of the display panel may be fixed to the first surface. 11b may be fixed to the second surface. The third area 811c of the display panel 801 is It may also be fixed to the third surface.

[0405] At least a portion of the display panel 801a may be fixed to the housing 802b. The fifth region 811e of the Nel 801 may be fixed to the housing 802b.

[0406] Figure 15A shows the electronic device 800D folded to its smallest size (into thirds). Yes. Figure 15B shows the electronic device 800D in its unfolded state. Figure 15C shows the electronic This figure shows the 800E device folded to its smallest size (into three folds). Figure 15D is This is a diagram showing the electronic device 800E in its unfolded state.

[0407] Electronic equipment 800D and electronic equipment 800E each have a flexible display panel 801 , housing 802a, housing 802b, housing 802c, hinge 803a, and hinge 803b To possess.

[0408] The display panel 801 can be a single, seamless, flexible display panel. A display device according to one embodiment of the present invention can be used for the display panel 801.

[0409] When electronic device 800D or electronic device 800E is deployed, the display panel 801 , a first region 811a overlapping with the housing 802a, and a second region 811 overlapping with the hinge 803a b, a third region 811c overlapping with the housing 802b, and a fourth region 81 overlapping with the hinge 803b. It has 1d and a fifth region 811e that overlaps with the housing 802c. These five regions are table It is preferable that it is included in the display area of ​​the display panel 801. In this region, the first region 811a, the third region 811c, and the fifth region 811e overlap with each other. In the state shown in Figures 15A and 15C, the user is in the first region 811a and The display in area 811b of 2 can be seen. In the state shown in Figures 15B and 15D, The user can see the display in all five areas.

[0410] Electronic devices 800D and 800E were folded as shown in Figures 15A and 15C. Sometimes, the second region 811b bends, causing the first region 811a and the third region 811c to bend. Each display surface faces the opposite surface.

[0411] Electronic devices 800D and 800E were folded as shown in Figures 15A and 15C. Sometimes, the fourth region 811d bends, causing the third region 811c and the fifth region 811e to bend. The two display surfaces face each other.

[0412] Enclosure 802a is connected to enclosure 802b via hinge 803a. Enclosure 802b is It is connected to the housing 802c via hinge 803b.

[0413] At least a portion of the display panel 801 may be fixed to the housing 802a. At least a portion of the 801 may be fixed to the housing 802b. Display panel 801 At least a portion of it may be fixed to the housing 802c.

[0414] Electronic equipment models 800A through 800D all feature a configuration where one of the multiple enclosures is used for other purposes. It is thicker than the enclosure of the electronic equipment 800A to electronic equipment 800C compared to the enclosure 802a. The chassis 802b is thicker. The electronic device 800D has a chassis 802b compared to chassis 802a and chassis 802b. 02c is thick.

[0415] The thick casing allows for the inclusion of a relatively large battery, the 827, and the power It allows the sub-device to operate for extended periods. Additionally, the thick casing accommodates a relatively heavy battery. By incorporating 27, the center of gravity of the electronic device remains within the thick casing even when deployed. It can be made into a part. It has a thicker housing than other housings, and the center of gravity is inside the thick housing. The presence of this feature improves the ease of holding electronic devices when they are laid flat. can.

[0416] For battery 827, it is preferable to use a lithium-ion battery that can increase capacity. It is preferable to provide a protection circuit 828 in the battery 827.

[0417] The electronic device 800E has a battery 827 built into the casing 802a. E has an easy-to-grip grip portion 806 at the end of the housing 802a, and the grip portion 806 has It can house the 827 battery. The center of gravity of the electronic device 800E is the heavy battery. Because it is located in the grip section 806 which contains 827, it can improve ease of holding. Furthermore, as shown in Figure 15D, when unfolded flat, the grip portion 806 is connected to the legs. This allows for stable use even on a desk. Furthermore, because the display surface is angled, It can also improve visibility.

[0418] The deformation of the electronic device in this embodiment may be performed manually, or by electrical power or springs, etc. It may also be done using mechanical power.

[0419] Electronic devices 800A to 800E are preferred to be easy to operate regardless of dominant hand. Electronic devices 800A to 800E are designed to be easily visible to the user. It is preferable that the image can be displayed in this manner.

[0420] This operation is performed, for example, by sensors (accelerometers, gyroscopes, etc.) in electronic devices. This is done by detecting the tilt of the electronic device and determining the orientation of the image display based on that tilt. Furthermore, the sensor can detect the shaking of electronic devices from changes in tilt. Because there are individual differences, artificial intelligence (AI) is used to learn about shaking information and make judgments based on the user. This function can be used for personal authentication.

[0421] Electronic devices 800A to 800E preferably have an antenna inside the housing. In this embodiment, antennas 825 and 826 are provided on the housing 802a. This shows the number of antennas and the locations where they are installed, but these are not limited to this. Antenna 825 Antenna 826 is a fourth-generation mobile communication system (4G) antenna, and antenna 826 is a fifth-generation This is an antenna for mobile communication systems (5G).

[0422] By mounting both antenna 825 and antenna 826 on housing 802a, good communication is achieved. It becomes easier to do. In particular, the display on the 800B to 800E electronic devices remains visible even when folded. It is often used in a way that makes it easy to see (how it is placed, how it is held, etc.). Therefore, the cabinet 8 The 02a is more likely to be facing in a direction that makes it easier to receive radio waves, thus improving radio wave reception.

[0423] Figure 16A shows an example of a television system. The television system 7100 is housed in a casing 7101 The display unit 7000 is incorporated into it. Here, the stand 7103 connects to the housing 7101. This shows a configuration that supports this.

[0424] A display device according to one embodiment of the present invention can be applied to the display unit 7000.

[0425] The television device 7100 shown in Figure 16A is operated using the control switches provided on the housing 7101. Alternatively, it can be done using a separate remote control unit 7111. Or, the display unit 7000 can be used. It may also be equipped with a touch sensor, and by touching the display unit 7000 with a finger, etc., the television will be activated. You may operate the unit 7100. The remote control unit 7111 It may have a display unit that displays information output from it. Remote control operator 7111 is equipped Channel and volume can be controlled using the control keys or touch panel. The image displayed on the display unit 7000 can be manipulated.

[0426] The television system 7100 will consist of a receiver and a modem, etc. This allows you to receive regular television broadcasts. Additionally, you can receive them via a modem using either a wired or wireless connection. By connecting to a line communication network, one-way (sender to receiver) or bidirectional communication is possible. It is also possible to communicate information in a direction (between a sender and receiver, or between receivers). ru.

[0427] Figure 16B shows an example of a notebook personal computer. The computer 7200 consists of a chassis 7211, a keyboard 7212, and a pointing device 721. 3. It has external connection ports 7214, etc. The display unit 7000 is incorporated into the housing 7211. It is.

[0428] A display device according to one embodiment of the present invention can be applied to the display unit 7000.

[0429] Figures 16C and 16D show examples of digital signage.

[0430] The digital signage 7300 shown in Figure 16C consists of a housing 7301, a display unit 7000, and a screen. It has a Pika 7303, etc. Furthermore, it has an LED lamp, an operation key (power switch, or operation key). It may include a switch, connection terminals, various sensors, a microphone, etc.

[0431] Figure 16D shows a digital signage 7400 mounted on a cylindrical column 7401. The digital signage 7400 has a display unit 7000 that is installed along the curved surface of the column 7401. do.

[0432] In Figures 16C and 16D, a display device according to one embodiment of the present invention is applied to the display unit 7000. It is possible.

[0433] The larger the display area 7000, the more information can be provided at once. The wider the area (7000), the more easily it catches people's attention, which can, for example, enhance the effectiveness of advertising. Cut.

[0434] By applying a touch panel to the display unit 7000, images or videos can be displayed on the display unit 7000. It's desirable that it not only displays information but also allows users to operate it intuitively. Also, route information... Alternatively, if used for purposes such as providing traffic information, intuitive operation is possible. This can improve usability.

[0435] Furthermore, as shown in Figures 16C and 16D, the digital signage 7300 or digital signage Inage 7400 is an information terminal 7311 or a smartphone owned by the user. It is preferable that the information terminal 7411 can be linked via wireless communication. For example, the display unit 7 Information about the advertisement displayed at 000 is shown on the screen of information terminal 7311 or information terminal 7411. It can be displayed on the information terminal 7311 or the information terminal 7411. This allows you to switch the display on the 7000 display unit.

[0436] In addition, the information terminal 7 is connected to the digital signage 7300 or digital signage 7400. Execute a game using the screen of either the 311 or the information terminal 7411 as the control device (controller). It is also possible to allow this. This allows a large number of users to participate in the game simultaneously and enjoy it. It is possible.

[0437] The electronic equipment shown in Figures 17A to 17F consists of a housing 9000, a display unit 9001, and a speaker 90 03. Operation key 9005 (including power switch or operation switch), connection terminal 900 6. Sensor 9007 (force, displacement, position, velocity, acceleration, angular velocity, rotational speed, distance, light, liquid, Magnetism, temperature, chemicals, sound, time, hardness, electric field, electric current, voltage, power, radiation, flow rate, humidity (Including functions for measuring degrees, incline, vibration, odor, or infrared radiation), Microphone 90 It has 08, etc.

[0438] The electronic devices shown in Figures 17A to 17F have various functions. For example, they can display various information (static Functions to display still images, videos, text images, etc. on the display unit, touch panel function, calendar - Functions that display the date or time, etc., processed by various software (programs) Functions to control the system, wireless communication functions, programs or data recorded on the recording medium. It may have functions such as reading and processing data. However, the functions of electronic devices are not limited to these. It is not limited to having multiple displays, and can have various functions. Furthermore, an electronic device may be equipped with a camera, etc., to capture still images or videos, and the recording medium (external or digital) may be used. Even if it has a function to save (built into the camera), a function to display captured images on the display unit, etc. good.

[0439] The details of the electronic equipment shown in Figures 17A to 17F will be explained below.

[0440] Figure 17A is a perspective view showing the personal digital assistant 9101. The personal digital assistant 9101 is, for example, It can be used as a smartphone. Note that the mobile information terminal 9101 has a speaker. 9003, connection terminal 9006, sensor 9007, etc. may be provided. Also, portable information terminal 9 101 can display text and image information on its multiple surfaces. Figure 17A shows three This shows an example of displaying icon 9050. It also shows information 9051, indicated by a dashed rectangle. The display unit 9001 can also be displayed on other sides. An example of information 9051 is electronic mail. Notifications of incoming calls, SNS messages, and phone calls; subject, sender name, and date / time for emails and SNS messages. This includes the time, battery level, and antenna signal strength. Alternatively, information 9051 may be displayed. You may display icons such as icon 9050 in the designated area.

[0441] Figure 17B is a perspective view showing the personal digital assistant 9102. The personal digital assistant 9102 displays It has the function of displaying information on three or more sides of section 9001. Here, information 9052, information 9 This shows an example where information 053 and 9054 are displayed on different sides. For example, the user With the mobile information terminal 9102 stored in the breast pocket of his clothing, the mobile information terminal 9102 Information 9053, displayed in a position that can be observed from above, can also be viewed by the user. Without taking the 9102 personal digital assistant out of your pocket, you can check the display and, for example, answer a phone call. It allows you to decide whether or not to do it.

[0442] Figure 17C is a perspective view showing a wristwatch-type personal information terminal 9200. Personal information terminal 920 0 can be used, for example, as a smartwatch. Also, the display unit 9001 is The display surface is curved, allowing the display to follow the curved surface. The wireless information terminal 9200 communicates with, for example, a wireless headset. It also allows for hands-free calling. Furthermore, the mobile information terminal 9200 has a connection terminal 90 With 06, it is also possible to transmit data to other information terminals and to charge them. Charging may also be performed via wireless power transfer.

[0443] Figures 17D to 17F are perspective views showing a foldable portable information terminal 9201. Figure 17D shows the mobile information terminal 9201 in its unfolded state, Figure 17F shows it in its folded state, and Figure 1 Figure 7E is a perspective view showing the transition from one state to the other in Figures 17D and 17F. The 9201 information terminal offers excellent portability when folded and a seamless, wide design when unfolded. The display area provides excellent readability. The display unit 9001 of the portable information terminal 9201 It is supported by three housings 9000 connected by hinges 9055. For example, The display unit 9001 can be bent with a radius of curvature of 0.1 mm or more and 150 mm or less.

[0444] This embodiment can be combined with other embodiments as appropriate.

[0445] <Reference example> In this reference example, the HOMO level of an organic compound and LUM in a display device according to one aspect of the present invention. This section explains how to calculate the O level and electron mobility.

[0446] The HOMO and LUMO levels are calculated based on cyclic voltammetry (CV) measurements. It is possible.

[0447] In this reference example, the measuring device used is an electrochemical analyzer (manufactured by BAS Corporation, model number...). Model: ALS Model 600A or 600C was used. The solution used in the CV measurement was solvent and Dehydrated dimethylformamide (DMF) (Aldrich Co., Ltd., 99.8%, Catalog Using (G number; 22705-6), the supporting electrolyte is tetra-n-butylammonium perchlorate. 1 nium (n-Bu4NClO4) (manufactured by Tokyo Chemical Industry Co., Ltd., catalog number: T0836) Dissolve to a concentration of 00 mmol / L, and then add the sample to be measured to a concentration of 2 mmol / L. It was prepared by dissolving it in such a manner. A platinum electrode (B.A.S. Co., Ltd.) was used as the working electrode. (Manufactured by B.A.S. Co., Ltd., PTE platinum electrode) and as an auxiliary electrode, a platinum electrode (manufactured by B.A.S. Co., Ltd., VC A Pt counter electrode (5cm) for -3 is used, and an Ag / Ag+ electrode (Bee) is used as the reference electrode. A reference electrode (RE7 non-aqueous solvent system, manufactured by A.S. Co., Ltd.) was used for each measurement. The measurements were taken at room temperature (2 The measurements were performed at temperatures between 0 and 25°C. The scan speed during CV measurement was standardized to 0.1V / sec for reference. The oxidation potential Ea [V] and reduction potential Ec [V] were measured relative to the electrode. Ea is the oxidation-reduction potential. The intermediate potential of the wave was taken, and Ec was taken as the intermediate potential of the reduction-oxidation wave. Here, the reference used in this example The potential energy of the illuminating electrode relative to the vacuum level was found to be -4.94 eV. Therefore, the HOMO level [eV] = -4.94 - Ea, and the LUMO level [eV] = -4 From the formula .94-Ec, we can determine the HOMO level and the LUMO level, respectively. ru.

[0448] Electron mobility is measured by impedance spectroscopy. It can be measured using the IS method.

[0449] The carrier mobility of EL materials is measured using transient photocurrent (Time-of-flight:T) spectroscopy. OF method and space-charge-limited current Methods such as the SCLC method, which is derived from the IV characteristics of nt (SCLC), have been known for a long time. The TOF method requires samples with considerably thicker film thicknesses compared to actual organic EL devices. The SCLC method has drawbacks, such as the inability to obtain the electric field strength dependence of carrier mobility. Therefore, since the thickness of the organic film required for measurement is thin, around several hundred nanometers, a relatively small amount of EL material is needed. However, it is possible to deposit films, and mobility can be measured with film thicknesses close to those of actual organic EL devices. A key feature is that it allows us to obtain the electric field strength dependence of carrier mobility.

[0450] In the IS method, a small sinusoidal voltage signal (V=V0[exp(jωt)]) is applied to the EL device. Uh, the current amplitude of that response current signal (I=I0exp[j(ωt+φ)]) and the input signal The impedance (Z=V / I) of the EL device is determined from the phase difference. By varying the frequency voltage and applying it to the EL device, various factors contribute to the impedance. Components with relaxation times can be separated and measured.

[0451] Here, the admittance Y (=1 / Z), which is the reciprocal of impedance, is given by the following equation (1): It can be expressed in terms of conductance G and susceptance B.

[0452]

number

[0453] Furthermore, the single-charge injection model shows that, respectively, Equations (2) and (3) can be calculated. Here, g (equation (4)) is the differential conduction. It is a chest of drawers. In the formula, C is capacitance, θ is ωT, and ω is the travel angle. represents the angular frequency. T is the travel time. The analysis involves the current equation, Poisson's equation, and the continuity of the current. The formula used ignores the existence of diffusion current and trap levels.

[0454]

number

[0455] The -ΔB method is a method for calculating mobility from the frequency characteristics of capacitance. The ωΔG method is a method for calculating mobility from the frequency characteristics of a device.

[0456] In practice, first, an electron-only device is fabricated for the material whose electron mobility is to be determined. A non-electron device is a device designed so that only electrons flow as carriers. This specification describes a method for calculating mobility from the frequency characteristics of capacitance (the -ΔB method). ru.

[0457] The structure of the electron-only device fabricated for measurement is shown in Figure 18A, and the specific configuration is shown in Table 1. As shown, the electron-only device fabricated in this reference example consists of a first electrode 901 (anode) and a second electrode 901. Between the electrode 902 (cathode) and the first layer 910, the second layer 911, and the third layer 912 are It possesses this property. The material for which you want to determine the electron mobility can be used as the material for the second layer 911. (Reference) For example, 2-{4-[9,10-di(naphthalene-2-yl)-2-antryl]phen 1-phenyl-1H-benzimidazole (abbreviation: ZADN) and 8-(quinolinola (t) For a lithium (abbreviation: Liq) co-deposited film in a 1:1 (weight ratio), its electron mobility The following was measured. In addition, in this reference example, 7-[4-(10-phenyl-9-antryl)phenyl [nyl]-7H-dibenzo[c,g]carbazole (abbreviation: cgDBCzPA), and 2 -[3'-(dibenzothiophen-4-yl)biphenyl-3-yl]dibenzo[f,h Electron mobility was also measured for quinoxaline (abbreviation: 2mDBTBPDBq-II). .

[0458] [Table 1]

[0459] An electron-only device fabricated using a co-evaporated film of ZADN and Liq as the second layer 911. The fluid density-voltage characteristics are shown in Figure 19.

[0460] Impedance measurement is performed by applying a DC voltage in the range of 5.0V to 9.0V while simultaneously measuring the AC voltage. Measurements were taken under the conditions of 70mV and a frequency of 1Hz to 3MHz. The impedance obtained here Capacitance is calculated from admittance (equation (1) above), which is the reciprocal of dance. Figure 20 shows the frequency characteristics of the calculated capacitance C at an applied voltage of 7.0V.

[0461] The frequency characteristics of capacitance C are determined by the spatial charge of carriers injected by a small voltage signal. This is obtained when the load cannot fully follow the minute AC voltage, resulting in a phase difference in the current. Here, the travel time of the carriers in the membrane is the time T it takes for the injected carriers to reach the counter electrode. It is defined and expressed by the following equation (5).

[0462]

number

[0463] The negative susceptance change (-ΔB) is the value obtained by multiplying the capacitance change -ΔC by the angular frequency ω (-ωΔ). This corresponds to C). Its lowest frequency peak frequency is f'. max (=ω max ( / 2π) and run From equation (3), the following relationship (6) can be derived between row time T and row time.

[0464]

number

[0465] Figure 2 shows the frequency characteristics of -ΔB calculated from the above measurements (i.e., when the DC voltage is 7.0V). As shown in 1. The lowest frequency peak frequency f' can be determined from Figure 21. max This is indicated by the arrow in the diagram. did.

[0466] f' obtained from the above measurements and analyses max Therefore, the travel time T can be determined (Equation (6)). From equation (5) above, we can determine the electron mobility at a voltage of 7.0V in this case. By performing similar measurements in the DC voltage range of 5.0V to 9.0V, each voltage (electric field strength) can be determined. Since electron mobility can be calculated at ), the electric field strength dependence of mobility can also be measured.

[0467] The electric field strength dependence of the electron mobility of each organic compound, finally obtained by the calculation method described above, The properties are shown in Figure 22, and the square root of the electric field strength [V / cm] read from the figure is 600 [V / cm]. m] 1 / 2 Table 2 shows the electron mobility values ​​at this time. In Figure 22, the square represents cgDBCz. The PA results show that the triangular shapes are from the 2mDBTBPDBq-II results, and the rhombic shapes are from the co-vaporation of ZADN and Liq. The results of the membrane deposition are shown.

[0468] [Table 2]

[0469] As described above, it is possible to calculate electron mobility. For detailed measurement methods, please refer to the following. Takayuki Okachi et al. "Japanese Journal of Applied Physics” Vol. 47, No. 12, 2008, See pp. 8965–8972. [Examples]

[0470] In this embodiment, a light-emitting device that can be used in a display device according to one aspect of the present invention is fabricated. I will now explain the results of the evaluation.

[0471] In this embodiment, the light-emitting devices are a device R1 that emits red light and a device that emits green light. This paper describes the results of fabricating and evaluating device G1 and device B1, which emits blue light. To clarify, Figure 18B shows the structure of the device used in this embodiment, and Table 3 shows the specific configuration. The chemical formulas of the materials used in this example are shown below.

[0472] [Table 3]

[0473] [ka]

[0474] [ka]

[0475] Fabrication of light-emitting devices Devices R1, G1, and B1 fabricated in this embodiment are shown in Figure 18B. As shown, a first electrode 130 is formed on a substrate (not shown), and positive Hole injection layer 131, hole transport layer 132a, hole transport layer 132b, light-emitting layer 133, electron transport layer Layers 134 and 135 are sequentially stacked, and a second electrode 14 is placed on the electron injection layer 135. Each device has a structure in which 0 is formed. Each device further has a buffer on the second electrode 140. It has a layer 136. The buffer layer 136 is connected to the second electrode 140 (semitransmissive / semireflective electrode) It has the function of reducing the loss of light energy due to surface plasmons. Buffer layer 13 As for point 6, various organic films that can be used in light-emitting devices can be employed.

[0476] First, a first electrode 130 was formed on the substrate. The electrode area was 4 mm². 2 (2mm x 2mm) The substrate used was a glass substrate. The first electrode 130 was made of silver (Ag) and palladium. An alloy of palladium (Pd) and copper (Cu) (Ag-Pd-Cu(APC)) is produced by sputtering. A film is formed, and then indium tin oxide (ITSO) containing silicon oxide is deposited by sputtering. This was done to form it. In device R1, APC was deposited to a film thickness of 100 nm. ITSO was deposited to a film thickness of 110 nm. In devices G1 and B1, APC was deposited to a thickness of 100 nm, and ITSO was deposited to a thickness of 85 nm. A film was formed. In this embodiment, the first electrode 130 functions as an anode.

[0477] Here, as a pretreatment, the surface of the substrate is washed with water, then fired at 200°C for 1 hour, followed by UV spectroscopy. The zoning treatment was performed for 370 seconds. After that, 10 -4 Vacuum deposition equipment with internal pressure reduced to approximately Pa The substrate is placed in the vacuum deposition apparatus and vacuum firing is performed at 170°C for 30 minutes in the heating chamber of the vacuum deposition apparatus. Afterward, I let the circuit board cool for about 30 minutes.

[0478] Next, a hole injection layer 131 was formed on the first electrode 130. The hole injection layer 131 was formed using vacuum vapor 10 inside the attachment device -4 After reducing the pressure to Pa, N,N-bis(4-biphenyl)-6-phenyl Benzo[b]naphtho[1,2-d]furan-8-amine (abbreviation: BBABnf) and ALD -MP001Q (Analysis Workshop Co., Ltd., Material serial number: 1S20180314) The weight ratio is 1:0.05 (=BBABnf:ALD-MP001Q), and the film thickness is 10nm. It was formed by co-deposition. ALD-MP001Q accepts electrons from BBABnf. It has a sexual nature.

[0479] Next, a hole transport layer 132a was formed on the hole injection layer 131. The hole transport layer 132a is B The hole transport layer 132a was formed by depositing BABnf. The thickness of the hole transport layer 132a was 30 nm in device R1. It is formed in such a way that the film thickness in device G1 is 10 nm, and device B1 Then, it was formed to a film thickness of 25 nm.

[0480] Next, a hole transport layer 132b was formed on top of the hole transport layer 132a.

[0481] The hole transport layer 132b of device R1 is N-(1,1'-biphenyl-4-yl)-N- [4-(9-phenyl-9H-carbazole-3-yl)phenyl]-9,9-dimethyl Using -9H-fluorene-2-amine (abbreviation: PCBBiF), the film thickness is 50 nm. It was formed by vapor deposition as shown.

[0482] The hole transport layer 132b of device G1 is 4,4'-diphenyl-4''-(9-phenyl Using -9H-carbazole-3-yl)triphenylamine (abbreviation: PCBBi1BP) The film was formed by vapor deposition to a thickness of 50 nm.

[0483] The hole transport layer 132b of device B1 is 3,3'-(naphthalene-1,4-diyl)bis (9-phenyl-9H-carbazole) (abbreviation: PCzN2) was used, and the film thickness was 10 nm. It was formed by vapor deposition in that manner.

[0484] Next, a light-emitting layer 133 was formed on the hole transport layer 132b.

[0485] The light-emitting layer 133 of device R1 is 9-[(3'-dibenzothiophen-4-yl)bife [Nil-3-yl]naphth[1',2':4,5]fl[2,3-b]pyrazine (abbreviation: 9 mDBtBPNfpr), N-[4-(9-phenyl-9H-carbazole-3-yl) Phenyl]-bis(9,9-dimethyl-9H-fluoren-2-yl)amine (abbreviation: P) CBFF), and ALD-MG018Q (Analysis Workshop Co., Ltd., Material serial number: 1S) Using 20161025), the weight ratio is 0.7:0.3:0.05 (=9mDBtBPNf (pr:PCBFF:ALD-MG018Q), co-deposited to a film thickness of 60nm to form Success. ALD-MG018Q is a red light-emitting substance.

[0486] The light-emitting layer 133 of device G1 is 8-(1,1'-biphenyl-4-yl)-4-[3- (dibenzothiophen-4-yl)phenyl]-[1]benzofl[3,2-d]pyrim Zin (abbreviation: 8BP-4mDBtPBfpm), 9-(2-naphthyl)-9'-phenyl -9H,9'H-3,3'-bicarbazole (abbreviation: βNCCP), and [2-d3- Methyl-(2-pyridinyl-κN)benzofloxacin [2,3-b]pyridine-κC]bis[2 -(2-pyridinyl-κN)phenyl-κC]iridium(III) (abbreviation: [Ir(p Using py)2(mbfpypy-d3)]), the weight ratio is 0.6:0.4:0.1 (=8 BP-4mDBtPBfpm:βNCCP:[Ir(ppy)2(mbfpypy-d3 )]), formed by co-depositing to a film thickness of 50 nm. [Ir(ppy)2(mbf Pypy-D3) is a green light-emitting substance.

[0487] The light-emitting layer 133 of device B1 is 9-(1-naphthyl)-10-[4-(2-naphthyl) Phenyl]anthracene (abbreviation: αN-βNPAnth), and 3,10-bis[N- (9-phenyl-9H-carbazole-2-yl)-N-phenylamino]naphtho[2, 3-b;6,7-b']bisbenzofuran (abbreviation: 3,10PCA2Nbf(IV)-0 2) Using the weight ratio 1:0.015 (=αN-βNPAnth:3,10PCA2Nb f(IV)-02), formed by co-evaporation to a film thickness of 25 nm. 3,10 PCA 2Nbf(IV)-02 is a blue light-emitting substance.

[0488] Next, an electron transport layer 134 was formed on the light-emitting layer 133. The electron transport layer 134 is composed of 2-{4-[9,10-di(naphthalene-2-yl)-2-ant [Lyl]phenyl}-1-phenyl-1H-benzimidazole (abbreviation: ZADN) and 8- It has a two-layer stacked structure with different mixing ratios of quinolinolato-lithium (abbreviated as Liq). The electron transport layer 134 is more cathode (second electrode 14) than anode (first electrode 130). Side 0) has a lower Liq content.

[0489] Specifically, the electron transport layer 134 in device R1 and device G1 is composed of ZADN and L IQ and LiQ were combined so that the weight ratio was 0.7:1 (=ZADN:LiQ) and the film thickness was 10 nm. Vapor deposition is performed, and then ZADN and Liq are added in a weight ratio of 1:1 (=ZADN:Liq), resulting in a film thickness. It was formed by co-depositing so that it was 25 nm. The electron transport layer 134 in device B1 is Co-deposited with a weight ratio of 0.3:1 (=ZADN:Liq) and a film thickness of 15 nm. Furthermore, ZADN and Liq were mixed with a weight ratio of 1:0.3 (=ZADN:Liq) and a film thickness of 1 It was formed by co-depositing to a size of 5 nm.

[0490] Next, an electron injection layer 135 was formed on the electron transport layer 134. The electron injection layer 135 is made of Liq It was formed by depositing using a material to achieve a film thickness of 1 nm.

[0491] Next, a second electrode 140 was formed on the electron injection layer 135. The second electrode 140 was made of silver (A (g) and magnesium (Mg) are used in a volume ratio of 1:0.1 (=Ag:Mg) with a film thickness of 15n. It was formed by co-depositing such that m. In this embodiment, the second electrode 140 is negative It functions as a pole.

[0492] Then, a buffer layer 136 was formed on the second electrode 140. The buffer layer 136 is 4, 4',4''-(benzene-1,3,5-triyl)tri(dibenzothiophene) (abbreviation) It was formed by depositing using DBT3P-II to a film thickness of 80 nm.

[0493] Through the above process, a light-emitting device was formed on a substrate, consisting of an EL layer sandwiched between a pair of electrodes. Furthermore, in the deposition process of the above-described manufacturing method, the deposition method using resistance heating was employed for all steps. .

[0494] Furthermore, the light-emitting device fabricated as described above is sealed with another substrate (not shown). Furthermore, when sealing using a different substrate (not shown), the glove box should be kept in a nitrogen atmosphere. In this process, another substrate (not shown) coated with an adhesive that hardens when exposed to ultraviolet light is fixed onto the substrate. Then, the substrates are bonded together so that adhesive adheres to the area around the light-emitting device formed on the substrate. During sealing, 365nm ultraviolet light at 6J / cm² was used. 2 Irradiate to solidify the adhesive, then heat to 80°C. The adhesive was stabilized by heat treatment for one hour.

[0495] <<Operating characteristics of light-emitting devices>> The operating characteristics of devices R1, G1, and B1 were measured. The test was conducted at room temperature (an atmosphere maintained at 25°C).

[0496] Figures 23 to 27 show the characteristics of device R1. Figure 23 shows the luminance-current density of device R1. Figure 24 shows the brightness characteristics. Figure 24 shows the brightness-voltage characteristics of device R1. Figure 5 shows the current efficiency-luminance characteristics of device R1. Figure 26 shows the current efficiency-luminance characteristics of device R1. This figure shows the current density-voltage characteristics. Figure 27 shows the current at 5 mA / cm² to device R1. 2 Current density is a diagram showing the emission spectrum when a current is applied.

[0497] Figures 28 to 32 show the characteristics of Device G1. Figure 28 shows the luminance-current densit y characteristics of Device G1. Figure 29 is a diagram showing the luminance-voltage characteristics of Device G1. Figure 3 0 is a diagram showing the current efficiency-luminance characteristics of Device G1. Figure 31 shows the curr ent density-voltage characteristics of Device G1. Figure 32 shows the emission spectrum when a current is applied to Device G1 at a current density of 5mA / cm 2 , which is a diagram showing the emission spectrum when a current is applied.

[0498] Figures 33 to 37 show the characteristics of Device B1. Figure 33 shows the luminance-current densit y characteristics of Device B1. Figure 34 is a diagram showing the luminance-voltage characteristics of Device B1. Figure 3 5 is a diagram showing the current efficiency-luminance characteristics of Device B1. Figure 36 shows the curr ent density-voltage characteristics of Device B1. Figure 37 shows the emission spectrum when a current is applied to Device B1 at a current density of 14.7mA / cm 2 curr ent density, which is a diagram showing the emission spectrum when a current is applied.

[0499] Table 4 shows the main initial characteristic values of each light-emitting device around 1000cd / m 2 .

[0500]

Table 4

[0501] As shown in Table 4, it was found that Devices R1, G1, and B1 each emit light with high color purity and have high efficiency.

[0502] As shown in Figure 27, Device R1 has an emission spectr This showed a peak at around 521 nm. Also, as shown in Figure 32, device G1 has a peak at around 521 nm. It showed an emission spectrum with a 'k'. Also, as shown in Figure 37, device B1 had 45 The emission spectrum showed a maximum peak around 9 nm.

[0503] Reliability characteristics of light-emitting devices Next, reliability tests were conducted on each light-emitting device. The results of the reliability tests are shown in Figures 38 to 40. As shown in Figures 38-40, the vertical axis represents the normalized luminance (%) when the initial luminance is set to 100%. The horizontal axis shows the operating time (h). Note that the reliability test was performed on device R1. Current density of 75 mA / cm² 2 Set the current density to 50m for devices G1 and B1. A / cm 2 The settings were configured, and each light-emitting device was driven.

[0504] Figure 38 shows that the normalized brightness of device R1 after 1080 hours was 84%. Figure 39 shows that the normalized brightness of device G1 after 23 hours was 96%. Figure 40 shows that the normalized brightness of device B1 after 530 hours was 95%.

[0505] Devices R1, G1, and B1 were found to exhibit behavior with low initial degradation. .

[0506] As described above, in this embodiment, by applying the ReSTI structure, red, green, and blue In any of the light-emitting devices that emit light, we aim to create light-emitting devices with a long operating life. This was possible. Furthermore, in this embodiment, by applying the ReSTI structure, fluorescence emission and phosphorus emission were achieved. We were able to fabricate light-emitting devices with long operating lifetimes in both photoluminescence and photoluminescence.

[0507] The three light-emitting devices fabricated in this embodiment each have a light-emitting layer containing different materials. On the other hand, the three light-emitting devices have layers made of the same material, and , there are layers of the same film thickness. Therefore, in the fabrication of a display device according to one aspect of the present invention, three colors By adding a common layer to the light-emitting device, a light-emitting device with a long operating life can be fabricated with fewer manufacturing steps. It was suggested that this is possible. [Examples]

[0508] In this embodiment, a light-emitting device that can be used in a display device according to one aspect of the present invention is fabricated. I will now explain the results of the evaluation.

[0509] In this embodiment, the light-emitting devices are a device R2 that emits red light and a device that emits green light. This paper describes the results of fabricating and evaluating device G2 and device B2, which emits blue light. To clarify, Figure 18B shows the structure of the device used in this embodiment, and Table 5 shows the specific configuration. This will be shown.

[0510] For details on the method of fabricating the light-emitting device in this embodiment, please refer to Example 1. The chemical formulas of the materials used in the example are shown below. Note that the chemical formulas of materials already shown are omitted.

[0511] [Table 5]

[0512] [ka]

[0513] As shown in Table 5, the electron transport layer 134 in the light-emitting device of this embodiment is made of ZADN and L It is a two-layer stacked structure in which the mixing ratio with iq is different from that of the other two layers. Specifically, the light-emitting device of this embodiment In the cis, the electron transport layer 134 is more responsive on the cathode (second electrode) side compared to the anode (first electrode 130) side. The electrode 140 side has a lower Liq content.

[0514] Furthermore, the light-emitting layer 133 of device G3 is composed of 8BP-4mDBtPBfpm, βNCCP, and B, [2-methyl-(2-pyridinyl-κN)benzofl[2,3-b]pyridine-κC ]bis[2-(2-pyridinyl-κN)phenyl-κC]iridium(III) (abbreviation: Using [Ir(ppy)2(mbfpypy)]), the weight ratio is 0.6:0.4:0.1( =8BP-4mDBtPBfpm:βNCCP:[Ir(ppy)2(mbfpypy) The film was formed by co-evaporating it to a thickness of 50 nm.

[0515] In this embodiment, device R2 emits red light, device G2 emits green light, and The emission color of device B2, which emits blue light, is the same as that of commercially available organic EL devices. It was manufactured to have the same chromaticity as the sub-pixels of a display device (smartphone).

[0516] Reliability characteristics of light-emitting devices Reliability tests were conducted on each light-emitting device. The results of the reliability tests are shown in Figure 41. Figure 41 In this graph, the vertical axis represents the normalized brightness (%) when the initial brightness is set to 100%, and the horizontal axis represents the brightness during operation. It indicates interval (h).

[0517] In this embodiment, device R2 emits red light, device G2 emits green light, Furthermore, a device B2 that emits blue light is used as a secondary display for the above-mentioned commercially available display device (smartphone). A reliability test was conducted by causing light emission at the same luminance and chromaticity as that of a light-emitting device (organic EL device) in an element In the commercially available display device, each color was displayed as a single color with a brightness gradation of 255 / 255 When light was emitted at a setting of (brightness 100%), the luminance of red (R) was 108 cd / m 2 , green (G) was 354 cd / m 2 , and blue (B) was 32.9 cd / m 2 Furthermore, for the commercially available display device, the aperture ratios of the sub-pixels were 4.5% for red, 4.3% for green, and 6.8% for blue. From these aperture ratio values and the respective luminance values of RGB in the above display device, the respective luminance within the (RGB) sub-pixels can be obtained. Finally, it is assumed that the transmittance including the circularly polarizing plate is 40% (the luminance within each (RGB) sub-pixel is divided by 0.4), whereby the luminance when driving devices R2, G2, and B2 can be determined. In the commercially available display device described above, each sub-pixel is provided with a color filter and a circularly polarizing plate, and the chromaticity and luminance of each organic EL device were measured through these components In the light-emitting devices of the present example as well, a color filter that transmits the corresponding color is placed on each light-emitting device, and the chromaticity and luminance of each light-emitting device were measured through the color filter

[0518] Table 6 shows the driving conditions in the reliability test for each light-emitting device. Specifically, for devices R2, G2, and B2, the initial luminances were 6580 cd / m 2 , 200000 cd / m 2 , and 1450 cd / m 2 respectively, and constant current driving was performed under these conditions

[0519]

Table 6

[0520] As shown in Figure 41, the LT95 of device R2 (when the brightness decreases to 95% of the initial brightness) The interval is over 3000 hours, and the LT95 of device G2 is 480 hours, and device The LT95 for the B2 was 1640 hours.

[0521] Generally, among red, green, and blue light-emitting devices, blue light-emitting devices have the longest operating life. While they tend to be shorter, in this embodiment, the light-emitting device is second only to the red light-emitting device. The operating life of the blue light-emitting device was long. In this embodiment, the light-emitting device that emits blue light The chair incorporates a fluorescent light-emitting layer and a ReSTI structure. This results in blue light. This allowed us to suppress the initial degradation of light-emitting devices that emit light, significantly extending their operating life. It is thought that...

[0522] Furthermore, if you want to make the luminescence lifetime equivalent for RGB, you need to change the aperture ratio of the subpixels for each color. Because the brightness can be changed, the lifespan of the light emission can be adjusted. Initial degradation is also suppressed during this process. Because the expected effects can be obtained, it is possible to create long-lasting light-emitting devices for each color. It is possible. Because blue fluorescence devices employing the ReSTI structure have a very long lifespan, In the case of OLED displays, the aperture ratio of the blue subpixels can be made smaller than in conventional displays. Furthermore, red phosphorescent devices using the ReSTI structure and ExTET also have a very long lifespan. Therefore, the aperture ratio of the red subpixel among RGB can be made the smallest. And R By setting the aperture ratio of the green subpixels in GB to the largest value, the balance of white display is maintained. This allows for an overall extension of the lifespan. The aperture ratio of the blue and red subpixels can be reduced. This is also advantageous for increasing the resolution of Pentile-type display devices.

[0523] As described above, in this embodiment, by applying the ReSTI structure, red, green, and blue In any of the light-emitting devices that emit light, we aim to create light-emitting devices with a long operating life. This was possible. Furthermore, in this embodiment, by applying the ReSTI structure, fluorescence emission and phosphorus emission were achieved. We were able to fabricate light-emitting devices with long operating lifetimes in both photoluminescence and photoluminescence.

[0524] The three light-emitting devices fabricated in this embodiment each have a light-emitting layer containing different materials. On the other hand, the three light-emitting devices have layers made of the same material, and , there are layers of the same film thickness. Therefore, in the fabrication of a display device according to one aspect of the present invention, three colors By adding a common layer to the light-emitting device, a light-emitting device with a long operating life can be fabricated with fewer manufacturing steps. It was suggested that this is possible.

[0525] <Reference example 2> In this reference example, the 8-(1,1'-biphenyl-4-yl) used in Examples 1 and 2 -4-[3-(dibenzothiophen-4-yl)phenyl]-[1]benzofl[3,2 -d] This section describes the synthesis method of pyrimidine (abbreviation: 8BP-4mDBtPBfpm). .

[0526] [ka]

[0527] 8-Chloro-4-[3-(dibenzothiophen-4-yl)phenyl]-[1]benzo [3,2-d]pyrimidine 1.37g, 4-biphenylboronic acid 0.657g, phosphate Tripotassium 1.91g, Diethylene glycol dimethyl ether (diglyme) 30 Place mL of t-butanol (0.662 g) into a three-necked flask and stir under reduced pressure. The system was then degassed and replaced with nitrogen.

[0528] This mixture is heated to 60°C, and 23.3 mg of palladium(II) acetate and di(1-adamantine) are added. 66.4 mg of tyl-n-butylphosphine was added and stirred at 120°C for 27 hours. Water was added to the reaction mixture and filtered by suction. The resulting filtrate was washed with water, ethanol, and toluene. This material was dissolved in heated toluene, and then filled in the following order: Celite, alumina, Celite. The solution was passed through a filtration aid. The resulting solution was concentrated, dried, and recrystallized with toluene. The target product, a white solid, was obtained in a yield of 1.28 g and a yield of 74%.

[0529] 1.26 g of this white solid was purified by sublimation using the train sublimation method. Sublimation purification Next, at a pressure of 2.56 Pa and with argon gas flowing at a flow rate of 10 mL / min, at 310°C... The solid was heated. After sublimation purification, 1.01 g of the target product was obtained as a pale yellow solid with a recovery rate of 80%. This synthesis scheme is shown in equation (a-1).

[0530] [ka]

[0531] Furthermore, nuclear magnetic resonance spectroscopy of the pale yellow solid obtained from the above reaction ( 1 Analysis results by H-NMR The results are shown below. From these results, it can be seen that 8BP-4mDBtPBfpm was obtained. Ta.

[0532] 1 H-NMR.δ(CDCl3):7.39(t,1H), 7.47-7.53(m,4 H), 7.63-7.67(m,2H), 7.68(d,2H), 7.75(d,2H) , 7.79-7.83(m,4H), 7.87(d,1H), 7.98(d,1H), 8 .02(d,1H), 8.23-8.26(m,2H), 8.57(s,1H), 8.7 3(d,1H), 9.05(s,1H), 9.34(s,1H). [Explanation of Symbols]

[0533] Data: Display data, Data_W: Data, DATA: Wiring, DATA_W: Wiring, G1: Wiring, G2: Wiring, M1: Transistor, M2: Transistor, M3: Transistor Ta, M4: Transistor, 10A: Display device, 10B: Display device, 10C: Display device, 1 0D: Display device, 10E: Display device, 21B: Optical, 21G: Optical, 21R: Optical, 42: Tra resistor, 100A: display device, 100B: display device, 101: anode, 102: cathode, 1 03: EL layer, 112: common layer, 114: common layer, 115: common electrode, 121: hole injection Layer, 122: Hole transport layer, 122a: Hole transport layer, 122b: Hole transport layer, 123: Luminescence layer layer, 123-1: light emitting region, 124: electron transport layer, 124-1: region, 124a: electron transport layer 124b: electron transport layer, 125: electron injection layer, 130: first electrode, 131: hole Injection layer, 132a: Hole transport layer, 132b: Hole transport layer, 133: Emission layer, 134: Electron Transport layer, 135: electron injection layer, 136: buffer layer, 140: second electrode, 142: adhesion Layer, 143: Space, 151: Substrate, 152: Substrate, 153: Substrate, 154: Substrate, 155 : Adhesive layer, 162: Display section, 164: Circuit, 165: Wiring, 166: Conductive layer, 172: F PC, 173: IC, 182: Common layer, 184: Common layer, 190: Light-emitting device, 190 B: Light-emitting device, 190G: Light-emitting device, 190R: Light-emitting device, 191: Pixel device 192: buffer layer, 192B: buffer layer, 192G: buffer layer, 192R: buffer 193: Light-emitting layer, 193B: Light-emitting layer, 193G: Light-emitting layer, 193R: Light-emitting layer, 194: Buffer layer, 194B: Buffer layer, 194G: Buffer layer, 194R: Buffer 195: protective layer, 195a: inorganic insulating layer, 195b: organic insulating layer, 195c: inorganic Insulating layer, 199: Optical adjustment layer, 199B: Optical adjustment layer, 199G: Optical adjustment layer, 199R : Optical adjustment layer, 201: Transistor, 202: Transistor, 204: Connector, 205 :transistor, 210:transistor, 211:insulating layer, 212:insulating layer, 213:insulating layer Edge layer, 214: insulating layer, 215: insulating layer, 216: partition, 218: insulating layer, 221: conductive Layers, 222a: conductive layer, 222b: conductive layer, 223: conductive layer, 225: insulating layer, 228: Region, 231: Semiconductor layer, 231i: Channel formation region, 231n: Low resistance region, 242 : Connecting layer, 800A: Electronic equipment, 800B: Electronic equipment, 800C: Electronic equipment, 800D: Electronic equipment, 800E: Electronic equipment, 801: Display panel, 801a: Display panel, 801b : Display panel, 802a: Enclosure, 802b: Enclosure, 802c: Enclosure, 803: Hinge, 8 03a: Hinge, 803b: Hinge, 806: Grip section, 811a: First area, 81 1b: Second region, 811c: Third region, 811d: Fourth region, 811e: Fifth region Area, 825: Antenna, 826: Antenna, 827: Battery, 828: Protection circuit, 90 1: First electrode, 902: Second electrode, 910: First layer, 911: Second layer, 912: The third layer consists of: 6500: electronic equipment, 6501: housing, 6502: display unit, 6503: power supply unit. Tongue, 6504: Button, 6505: Speaker, 6506: Microphone, 6507: Camera, 6508: Light source, 6510: Protective component, 6511: Display panel, 6512: Optical component, 6 513: Touch sensor panel, 6515: FPC, 6516: IC, 6517: Print Circuit board, 6518: Battery, 7000: Display unit, 7100: Television equipment, 7101 : Enclosure, 7103: Stand, 7111: Remote control unit, 7200: Notebook personal computer Computer, 7211: Case, 7212: Keyboard, 7213: Pointing Desk Vice, 7214: External connection port, 7300: Digital signage, 7301: Enclosure, 7303: Speaker, 7311: Information terminal, 7400: Digital signage, 7401 : Pillar, 7411: Information terminal, 9000: Enclosure, 9001: Display unit, 9003: Speaker 9005: Operation key, 9006: Connection terminal, 9007: Sensor, 9008: Microphone On, 9050: Icon, 9051: Information, 9052: Information, 9053: Information, 905 4: Information, 9055: Hinge, 9101: Mobile information terminal, 9102: Mobile information terminal, 92 00: Mobile information terminal, 9201: Mobile information terminal

Claims

1. It comprises a first light-emitting device, a second light-emitting device, and a third light-emitting device. The first light-emitting device has a first electrode and a common electrode, The second light-emitting device has a second electrode and the common electrode, The third light-emitting device has a third electrode and the common electrode, The first light-emitting device has a first hole injection layer, a first hole transport layer, a second hole transport layer, a first light-emitting layer, and a first electron transport layer between the first electrode and the common electrode. The second light-emitting device has a second hole injection layer, a third hole transport layer, a fourth hole transport layer, a second light-emitting layer, and a second electron transport layer between the second electrode and the common electrode. The third light-emitting device has a third hole injection layer, a fifth hole transport layer, a sixth hole transport layer, a third light-emitting layer, and a third electron transport layer between the third electrode and the common electrode. The second hole transport layer is in contact with the first light-emitting layer, The fourth hole transport layer is in contact with the second light-emitting layer, The sixth hole transport layer is in contact with the third light-emitting layer, The first light-emitting layer has a fluorescent light-emitting material that emits light of a first color, The second light-emitting layer has a first phosphorescent material that emits light of a second color, The third light-emitting layer has a second phosphorescent material that emits light of a third color, The first hole injection layer, the second hole injection layer, and the third hole injection layer each contain the first compound and the second compound, The HOMO level of the second compound is between -5.7 eV and -5.4 eV. The first compound has electron-accepting properties for the second compound, The first hole transport layer, the third hole transport layer, and the fifth hole transport layer each contain the third compound. The difference between the HOMO level of the third compound and the HOMO level of the second compound is within 0.2 eV. The compounds contained in the second hole transport layer, the compounds contained in the fourth hole transport layer, and the compounds contained in the sixth hole transport layer are all different compounds. The first electron transport layer, the second electron transport layer, and the third electron transport layer each comprise a third organic compound and a first substance. The third organic compound has a heterocyclic skeleton, A display device in which the first substance is a metal, a metal salt, a metal oxide, or an organometallic salt.

2. In claim 1, A display device wherein the HOMO level of the third compound is less than or equal to the HOMO level of the second compound.

3. In claim 1 or 2, A display device wherein the HOMO level of the fourth compound contained in the second hole transport layer is lower than the HOMO level of the third compound.

4. In any one of claims 1 to 3, A display device wherein the HOMO level of the fifth compound contained in the fourth hole transport layer is lower than the HOMO level of the third compound.

5. In any one of claims 1 to 4, A display device wherein the HOMO level of the sixth compound contained in the sixth hole transport layer is lower than the HOMO level of the third compound.

6. In any one of claims 1 to 5, A display device wherein the second compound and the third compound are the same compound.

7. In any one of claims 1 to 6, The third compound is a display device having a HOMO level of -6.0 eV or higher.

8. In any one of claims 1 to 7, The second light-emitting layer comprises a fourth organic compound and a fifth organic compound, A display device in which the fourth organic compound and the fifth organic compound are a combination that forms an excited complex.

9. In any one of claims 1 to 8, The third light-emitting layer comprises a sixth organic compound and a seventh organic compound, A display device in which the sixth organic compound and the seventh organic compound are a combination that forms an excited complex.

10. In any one of claims 1 to 9, The first color is blue, The second color is green, The third color of the display device is red.

11. In any one of claims 1 to 10, A display device in which the first substance is an organometallic complex having an alkali metal or alkaline earth metal.

12. A display device according to any one of claims 1 to 11, A display module having at least one connector and an integrated circuit.

13. The display module according to claim 12, An electronic device having at least one of an antenna, a battery, a housing, a camera, a speaker, a microphone, and an operating button.

Images