Light-emitting device

Abstract

Provided is a light-emitting device having excellent luminous efficiency. Alternatively provided is a light-emitting device having excellent reliability. Alternatively provided is a display device having excellent luminous efficiency and excellent reliability. Provided is a light-emitting device comprising a first electrode, a second electrode, a light-emitting layer positioned between the first electrode and the second electrode, and a cap layer. The second electrode is positioned between the light-emitting layer and the cap layer. The cap layer has at least a first substance and a second substance. The first substance and the second substance are such that the ordinary refractive indexes, at a wavelength of 380-760 nm, of vapor-deposited films composed of the respective substances differ by 0.1 or more. The first substance is an organic compound having a saturated hydrocarbon group and a skeleton that has electron transport properties.

Description

Light-emitting devices

[0001] One embodiment of the present invention relates to an organic compound, an organic semiconductor element, a light-emitting device, a photodiode sensor, a display module, a lighting module, a display device, an electronic device, a lighting device, and an electronic device. Note that one embodiment of the present invention is not limited to the above technical field. The technical field of one embodiment of the invention disclosed in this specification etc. relates to an object, a method, or a manufacturing method. Alternatively, one embodiment of the present invention relates to a process, a machine, manufacture, or a composition of matter. Therefore, more specifically, examples of the technical field of one embodiment of the present invention disclosed in this specification include a semiconductor device, a display device, a liquid crystal display device, a lighting device, a power storage device, a memory device, an imaging device, a driving method thereof, or a manufacturing method thereof.

[0002] Light-emitting devices (also called organic EL elements) that utilize electroluminescence (EL) using organic compounds are becoming increasingly practical. The basic structure of these light-emitting devices is a pair of electrodes sandwiching an organic compound layer containing a light-emitting material. By applying a voltage to this device, carriers are injected, and the recombination energy of the carriers is utilized to emit light from the light-emitting material.

[0003] Since light-emitting devices are self-luminous, display devices using these light-emitting devices as pixels have higher visibility than liquid crystal display devices and do not require backlighting. Another major advantage of display devices using such light-emitting devices is that they can be fabricated to be thin and lightweight. Another feature is their extremely fast response speed.

[0004] Furthermore, these light-emitting devices can have a continuous, planar light-emitting layer, which allows them to emit light in a planar manner. This is a feature that is difficult to obtain with point light sources such as incandescent lamps and LEDs, or linear light sources such as fluorescent lamps, making them highly useful as planar light sources for lighting applications.

[0005] Display devices and lighting devices using such light-emitting devices are suitable for a variety of electronic devices, but research and development is ongoing to find light-emitting devices with even better characteristics.

[0006] Patent Document 1 discloses a light-emitting device using organic electroluminescence having a capping layer that can improve light extraction efficiency.

[0007] JP 2015-092485 A

[0008] An object of one embodiment of the present invention is to provide a novel light-emitting device.An object of one embodiment of the present invention is to provide a light-emitting device with good characteristics.Another object of one embodiment of the present invention is to provide a light-emitting device with good reliability.Another object of one embodiment of the present invention is to provide a light-emitting device with high luminous efficiency.Another object of one embodiment of the present invention is to provide a light-emitting device with good reliability and high luminous efficiency.

[0009] Another object of one embodiment of the present invention is to provide a display device with favorable characteristics.Another object of one embodiment of the present invention is to provide a display device with favorable reliability.Another object of one embodiment of the present invention is to provide a display device with low power consumption.Another object of one embodiment of the present invention is to provide a light-emitting device with favorable reliability and low power consumption.

[0010] Another object of one embodiment of the present invention is to provide either an electronic device or a lighting device with high reliability, or an electronic device or a lighting device with low power consumption.

[0011] The present invention is intended to solve any one of the above-mentioned problems. Note that the description of these problems does not preclude the existence of other problems. Note that one embodiment of the present invention does not necessarily solve all of these problems. Note that problems other than these will become apparent from the description in the specification, drawings, claims, etc., and it is possible to extract other problems from the description in the specification, drawings, claims, etc.

[0012] One embodiment of the present invention is a light-emitting device including a first electrode, a second electrode, a light-emitting layer located between the first electrode and the second electrode, and a capping layer, wherein the second electrode is located between the light-emitting layer and the capping layer, the capping layer includes at least a first substance and a second substance, the first substance and the second substance being substances whose ordinary refractive indices at any wavelength from 380 nm to 760 nm differ by 0.1 or more when formed as evaporated films, and the first substance is an organic compound having a skeleton having electron-transporting properties and a saturated hydrocarbon group.

[0013] Another embodiment of the present invention is a light-emitting device including a first electrode, a second electrode, a light-emitting layer located between the first electrode and the second electrode, and a capping layer, wherein the second electrode is located between the light-emitting layer and the capping layer, and the capping layer includes a first layer containing at least a first substance and a second layer containing a second substance, the first substance and the second substance being substances whose ordinary refractive indices at any wavelength from 380 nm to 760 nm differ by 0.1 or more when formed as evaporated films, and the first substance is an organic compound having a skeleton having electron-transporting properties and a saturated hydrocarbon group.

[0014] Another embodiment of the present invention is a light-emitting device including a first electrode, a second electrode, a light-emitting layer located between the first electrode and the second electrode, and a capping layer, wherein the second electrode is located between the light-emitting layer and the capping layer, the capping layer includes a first layer containing at least a second substance and a second layer containing the first substance, the first layer is located between the second electrode and the second layer, the first substance and the second substance are substances whose ordinary refractive indices at any wavelength from 380 nm to 760 nm differ by 0.1 or more when formed as evaporated films, and the first substance is an organic compound having a skeleton having electron-transporting properties and a saturated hydrocarbon group.

[0015] Another embodiment of the present invention is a light-emitting device including a first electrode, a second electrode, a light-emitting layer located between the first electrode and the second electrode, and a capping layer, wherein the second electrode is located between the light-emitting layer and the capping layer, the capping layer includes a first layer containing at least a first substance and a second layer containing a second substance, the first layer is in contact with the second electrode, the first substance and the second substance are vapor-deposited films of which have ordinary refractive indices that differ by 0.1 or more at any wavelength from 380 nm to 760 nm, and the first substance is an organic compound having a skeleton having electron-transporting properties and a saturated hydrocarbon group.

[0016] Another embodiment of the present invention is a light-emitting device including a first electrode, a second electrode, a light-emitting layer located between the first electrode and the second electrode, and a capping layer, wherein the second electrode is located between the light-emitting layer and the capping layer, and the capping layer includes a first layer containing at least a first substance and a second layer containing a second substance, the first substance and the second substance being substances whose ordinary refractive indices at any wavelength from 380 nm to 760 nm differ by 0.1 or more in their evaporated films, the first substance being an organic compound having a skeleton having electron-transporting properties and a saturated hydrocarbon group, and the second substance being an organic compound.

[0017] Another embodiment of the present invention is a light-emitting device having any of the above structures, in which the organic compound has 1 to 10 saturated hydrocarbon groups, preferably 1 to 8 saturated hydrocarbon groups.

[0018] Another embodiment of the present invention is a light-emitting device having the above structure, wherein the saturated hydrocarbon group is a branched alkyl group having three or more carbon atoms.

[0019] Another embodiment of the present invention is a light-emitting device having the above structure, wherein the first substance and the second substance are materials whose refractive indices for ordinary light at any wavelength from 380 nm to 760 nm in the evaporated films thereof differ by 0.3 or more.

[0020] Another embodiment of the present invention is a light-emitting device having any of the above structures, in which an electron-transport layer is provided between the light-emitting layer and the second electrode, and the electron-transport layer contains the first substance.

[0021] Another embodiment of the present invention is a light-emitting device having the above structure, in which the first substance is an organic compound represented by General Formula (G1) below.

[0022]

[0023] In the above general formula (G1), Q １ ~Q ６ represents N (nitrogen atom) or C (carbon atom), and Q １ ~Q ６ 1 to 3 are N, and the remaining C is R １ n is any one of 1 to 5, and n R １ may be the same or different. １ each independently represents hydrogen (including deuterium), a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms, a substituted or unsubstituted alicyclic group having 3 to 10 carbon atoms, a substituted or unsubstituted aromatic hydrocarbon group having 6 to 30 carbon atoms, or a substituted or unsubstituted heteroaromatic hydrocarbon group having 1 to 30 carbon atoms. １ At least one or n R １ At least one of the substituents contained in the group is a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms or a substituted or unsubstituted alicyclic group having 3 to 10 carbon atoms.

[0024] Alternatively, another embodiment of the present invention is a light-emitting device having the above-described structure, wherein the evaporated film of the first substance has an ordinary refractive index of 1.70 or less at 450 nm, and the evaporated film of the second substance has an ordinary refractive index of 1.80 or more at 450 nm.

[0025] Alternatively, another embodiment of the present invention is a light-emitting device having the above-described structure, wherein the evaporated film of the first substance has an ordinary refractive index of 1.70 or less at 450 nm, and the evaporated film of the second substance has an ordinary refractive index of 2.00 or more at 450 nm.

[0026] Another embodiment of the present invention is a display device including any of the above light-emitting devices.

[0027] Another embodiment of the present invention is an electronic device including any of the above light-emitting devices and a sensor, an operation button, a speaker, or a microphone.

[0028] Another embodiment of the present invention is a lighting device including the above-described light-emitting device and a housing.

[0029] According to one embodiment of the present invention, a novel light-emitting device can be provided. A light-emitting device with favorable characteristics can be provided. Alternatively, according to one embodiment of the present invention, a light-emitting device with favorable reliability can be provided. Alternatively, according to one embodiment of the present invention, a light-emitting device with high emission efficiency can be provided. Alternatively, according to one embodiment of the present invention, a light-emitting device with favorable reliability and high emission efficiency can be provided.

[0030] Alternatively, one embodiment of the present invention can provide a display device with favorable characteristics. Alternatively, one embodiment of the present invention can provide a display device with favorable reliability. Alternatively, one embodiment of the present invention can provide a display device with low power consumption. Alternatively, one embodiment of the present invention can provide a light-emitting device with favorable reliability and low power consumption.

[0031] Alternatively, one embodiment of the present invention can provide either an electronic device or a lighting device with high reliability, or an electronic device or a lighting device with low power consumption.

[0032] Note that the description of these effects does not preclude the existence of other effects. Note that one embodiment of the present invention does not necessarily have all of these effects. Note that effects other than these will become apparent from the description in the specification, drawings, claims, etc., and it is possible to extract other effects from the description in the specification, drawings, claims, etc.

[0033] FIGS. 1A, 1B, and 1C are schematic diagrams of a light-emitting device according to one embodiment of the present invention. FIG. 2 is a schematic diagram of a light-emitting device according to one embodiment of the present invention. FIGS. 3A and 3B are diagrams illustrating a display device according to one embodiment of the present invention. FIGS. 4A and 4B are diagrams illustrating a display device according to one embodiment of the present invention. FIGS. 5A, 5B, 5C, 5D, and 5E are cross-sectional views illustrating an example of a method for manufacturing a display device. FIGS. 6A and 6B are cross-sectional views illustrating an example of a method for manufacturing a display device. FIGS. 7A, 7B, 7C, and 7D are cross-sectional views illustrating an example of a method for manufacturing a display device. FIGS. 8A, 8B, and 8C are cross-sectional views illustrating an example of a method for manufacturing a display device. FIGS. 9A, 9B, and 9C are cross-sectional views illustrating an example of a method for manufacturing a display device. FIGS. 10A, 10B, and 10C are cross-sectional views illustrating an example of a method for manufacturing a display device. FIGS. 11A and 11B are perspective views illustrating a structural example of a display module. FIGS. 12A and 12B are cross-sectional views illustrating a structural example of a display device. FIG. 13 is a perspective view showing an example of the configuration of a display device. FIG. 14 is a cross-sectional view showing an example of the configuration of a display device. FIG. 15 is a cross-sectional view showing an example of the configuration of a display device. FIGS. 16A, 16B, and 16C are cross-sectional views showing an example of the configuration of a display device. FIG. 17 is a cross-sectional view showing an example of the configuration of a display device. FIGS. 18A, 18B, and 18C are cross-sectional views showing an example of the configuration of a display device. FIGS. 19A, 19B, 19C, and 19D are diagrams showing examples of electronic devices. FIGS. 20A, 20B, 20C, 20D, 20E, and 20F are diagrams showing examples of electronic devices. FIGS. 21A, 21B, 21C, 21D, 21E, 21F, and 21G are diagrams showing examples of electronic devices. Fig. 22 is a diagram showing the refractive indexes of mmtBumTPTzn-03, oBP-mmtBumBPTzn, mmtBumBP2Tzn, and DBfBB1TP. Fig. 23 is a diagram showing the luminance-current density characteristics of light-emitting devices 1-1 to 1-3 and the comparative light-emitting device 1. Fig. 24 is a diagram showing the current efficiency-luminance characteristics of light-emitting devices 1-1 to 1-3 and the comparative light-emitting device 1. Fig. 25 is a diagram showing the luminance-voltage characteristics of light-emitting devices 1-1 to 1-3 and the comparative light-emitting device 1.FIG. 26 is a graph showing the current density-voltage characteristics of light-emitting devices 1-1 to 1-3 and comparative light-emitting device 1. FIG. 27 is a graph showing the blue index-current density characteristics of light-emitting devices 1-1 to 1-3 and comparative light-emitting device 1. FIG. 28 is a graph showing the electroluminescence spectra of light-emitting devices 1-1 to 1-3 and comparative light-emitting device 1. FIG. 29 is a graph showing the refractive indexes of mmCF3Ph-mDMePyPTzn and DBfBB1TP. FIG. 30 is a graph showing the luminance-current density characteristics of light-emitting device 2 and comparative light-emitting device 2. FIG. 31 is a graph showing the current efficiency-luminance characteristics of light-emitting device 2 and comparative light-emitting device 2. FIG. 32 is a graph showing the luminance-voltage characteristics of light-emitting device 2 and comparative light-emitting device 2. FIG. 33 is a graph showing the current density-voltage characteristics of light-emitting device 2 and comparative light-emitting device 2. FIG. 34 is a graph showing the blue index-current density characteristics of light-emitting device 2 and comparative light-emitting device 2. FIG. 35 shows electroluminescence spectra of Light-Emitting Device 2 and Comparative Light-Emitting Device 2. As shown in FIG.

[0034] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. However, the present invention is not limited to the following description, and it will be readily understood by those skilled in the art that various changes in form and details can be made without departing from the spirit and scope of the present invention. Therefore, the present invention should not be interpreted as being limited to the description of the embodiments shown below.

[0035] Furthermore, in this specification, ordinal numbers such as "first" and "second" are used to avoid confusion among constituent elements, and do not limit the number of constituent elements or the order of the constituent elements (for example, the order of processes or the order of stacking). Furthermore, even if a term does not have an ordinal number in this specification, ordinal numbers may be added in the claims to avoid confusion among the constituent elements. Even if a term has an ordinal number in this specification, ordinal numbers may be added in the claims. Even if a term has an ordinal number in this specification, ordinal numbers may be omitted in the claims.

[0036] In this specification, etc., a device fabricated using a metal mask or an FMM (fine metal mask, high-resolution metal mask) may be referred to as a device with an MM (metal mask) structure. In addition, in this specification, etc., a device fabricated without using a metal mask or an FMM may be referred to as a device with an MML (metal maskless lithography) structure.

[0037] Furthermore, when light is incident on a material with optical anisotropy, the light in the vibration plane parallel to the optical axis is called extraordinary light (ray), and the light in the vibration plane perpendicular to the optical axis is called ordinary light (ray). However, the refractive index of the material for ordinary light and extraordinary light may differ. In such cases, anisotropy analysis can be performed to separate the ordinary and extraordinary refractive indices and calculate each refractive index. In this specification, if the measured material has both an ordinary refractive index and an extraordinary refractive index, the ordinary refractive index will be used as the index. Furthermore, when simply referring to the refractive index, it will refer to the average value of the ordinary and extraordinary refractive indices.

[0038] Similarly to the refractive index, the extinction coefficient may have different values ​​for ordinary and extraordinary light, and by performing anisotropy analysis, it is possible to separate the ordinary and extraordinary light extinction coefficients and calculate each extinction coefficient separately. In this specification, when the measured material has both an ordinary light extinction coefficient and an extraordinary light extinction coefficient, the ordinary light extinction coefficient is used as the index, and when simply referring to the extinction coefficient, it refers to the average value of the ordinary light extinction coefficient and the extraordinary light extinction coefficient.

[0039] In this specification and the like, a photoluminescence (PL) spectrum refers to a spectrum obtained in fluorometry by fixing the excitation wavelength of excitation light and measuring the wavelength of emitted light. It may also be referred to as an emission spectrum. The emission spectrum may contain a fluorescent component and a phosphorescent component. In this specification and the like, an emission spectrum consisting of a fluorescent component may be particularly referred to as a fluorescence spectrum, and an emission spectrum consisting of a phosphorescent component may be particularly referred to as a phosphorescent spectrum.

[0040] In addition, the vapor-deposited film in this specification refers to a film formed by vapor deposition on a substrate at room temperature.

[0041] 1A illustrates a light-emitting device 600 according to one embodiment of the present invention. The light-emitting device illustrated in FIG. 1 includes a first electrode 101, a second electrode 102, an organic compound layer 103, and a cap layer 155. The organic compound layer 103 includes at least a light-emitting layer 113.

[0042] The second electrode 102 is a light-transmitting electrode, and the light-emitting device 600 has a structure in which light is emitted from the second electrode 102 side.

[0043] The second electrode 102 is provided in contact with the organic compound layer 103 and the cap layer 155 , and the second electrode 102 is sandwiched between the organic compound layer 103 and the cap layer 155 .

[0044] The cap layer 155 is a layer containing at least a first substance and a second substance. The first substance is an organic compound having a skeleton with electron-transporting properties and a saturated hydrocarbon group. The second substance is a substance different from the organic compound having a skeleton with electron-transporting properties and a saturated hydrocarbon group, and is preferably an organic compound.

[0045] By including the first material and the second material in the cap layer 155, heat resistance is improved, and it is possible to provide a light-emitting device with good reliability.

[0046] The capping layer 155 preferably includes a first layer containing a first substance and a second layer containing a second substance. The organic compound containing a skeleton with electron transport properties and a saturated hydrocarbon group, which is the first substance contained in the first layer, can be easily made into an organic compound with a low refractive index, so the refractive index between the first layer and the second layer can be made significantly different. Specifically, the ordinary refractive index at any wavelength from 380 nm to 760 nm can be easily made to differ by 0.1 or more, preferably 0.3 or more. This can further improve the light extraction efficiency of the light-emitting device. In this case, the first layer is preferably located between the second electrode and the second layer because this significantly improves the light extraction efficiency.

[0047] Here, when comparing a certain organic compound A with an organic compound B obtained by substituting a saturated hydrocarbon group, which is a substituent with a low molecular refraction, in the organic compound A, it has been found that the refractive index of the organic compound B tends to be lower than that of the organic compound A. Furthermore, as the number of saturated hydrocarbon groups introduced increases, the refractive index tends to decrease accordingly, and therefore, the refractive index of an organic compound B1, which has a large number of saturated hydrocarbon groups, can usually be made lower than that of an organic compound B2, which has a small number of saturated hydrocarbon groups.

[0048] On the other hand, the introduction of a saturated hydrocarbon group tends to increase the distance between adjacent molecular orbitals of the organic compounds into which carriers can easily enter, which may inhibit the intermolecular movement of carriers. As a result, the carrier transport property of organic compound B1 is likely to be lower than that of organic compound A and organic compound B2.

[0049] That is, when an organic compound with a low ordinary refractive index is used to increase the difference in ordinary refractive index between the first layer and the second layer, the organic compound may have poor carrier transport properties, making it difficult to use the organic compound in the EL layer of a light-emitting device.

[0050] On the other hand, the present inventors have found that organic compounds having a skeleton with electron transport properties, particularly organic compounds having a triazine ring, experience a greater decrease in refractive index due to the introduction of saturated hydrocarbon groups than other organic compounds. That is, they have found that organic compounds having a skeleton with electron transport properties and saturated hydrocarbon groups exhibit a sufficiently low refractive index even when the number of saturated hydrocarbon groups they have is small. Because organic compounds having a skeleton with electron transport properties have excellent electron transport properties, organic compounds having a skeleton with electron transport properties and saturated hydrocarbon groups can be made into organic compounds with a low refractive index while maintaining high electron transport properties.

[0051] An organic compound with high carrier transport properties can also be used in the EL layer of the light-emitting layer. Since an organic compound having a skeleton with electron transport properties and a saturated hydrocarbon group maintains high electron transport properties, it can also be suitably used as a material for constituting the electron transport layer in the EL layer of a light-emitting device. This allows the EL layer and the cap layer to be made of the same material.

[0052] By using the same material for the EL layer and the cap layer, the number of materials used and the number of evaporation sources in the evaporation device can be reduced, thereby making it possible to reduce manufacturing costs.

[0053] Furthermore, the light extraction efficiency of a light-emitting device can be improved by using a material with a low refractive index for the EL layer. Since an organic compound having an electron-transporting skeleton and a saturated hydrocarbon group can easily be made into an organic compound with a low refractive index, the use of such an organic compound as a material for the EL layer can further improve the light extraction efficiency and provide a light-emitting device with good current efficiency and external quantum efficiency. In addition to the increased light extracted by the low refractive index material in the EL layer, a light-emitting device with even better current efficiency and external quantum efficiency can be obtained by including a capping layer according to one embodiment of the present invention.

[0054] Furthermore, because saturated hydrocarbon groups reduce adhesion to electrodes, organic compounds containing many saturated hydrocarbon groups have poor adhesion to electrodes and may cause peeling. Therefore, organic compounds having a skeleton with electron transport properties and saturated hydrocarbon groups, which can be made into organic compounds with a low refractive index even with a small number of saturated hydrocarbon groups, can be suitably used as materials for forming capping layers in contact with electrodes, making it possible to provide display devices that are less susceptible to peeling and have high reliability. Furthermore, although organic compounds containing many saturated hydrocarbon groups are thought to make it difficult to inject carriers from electrodes, the use of organic compounds having a skeleton with electron transport properties and saturated hydrocarbon groups, which can be made into organic compounds with a low refractive index even with a small number of saturated hydrocarbon groups, makes it possible to provide display devices with excellent carrier injection from electrodes, low driving voltages, and low power consumption.

[0055] The electron-transporting skeleton in the organic compound having a skeleton with electron transport properties and a saturated hydrocarbon group includes a heteroaromatic ring, particularly a π-electron-deficient heteroaromatic ring. The organic compound having a skeleton with electron transport properties and a saturated hydrocarbon group preferably includes one or more π-electron-deficient heteroaromatic rings. The π-electron-deficient heteroaromatic ring is preferably, for example, a six-membered heteroaromatic ring containing one to three nitrogen atoms, such as a pyridine ring, a diazine ring (pyrazine ring, pyrimidine ring, or pyridazine ring), or a triazine ring (1,2,3-triazine ring, 1,2,4-triazine ring, or 1,3,5-triazine ring). The π-electron-deficient heteroaromatic ring may be a fused ring, and examples of bicyclic fused rings include a quinoline ring, a quinazoline ring, a quinoxaline ring, a benzoquinoxaline ring, a dibenzoquinoxaline ring, a benzoquinazoline ring, and a dibenzoquinazoline ring. From the viewpoint of reducing the refractive index, the fewer the number of fused rings, the better, and therefore a monocyclic or bicyclic fused ring is preferred. When a π-electron-deficient heteroaromatic ring having three or more fused rings is used, a low refractive index and high electron transport or electron injection properties can be achieved by combining it with a saturated hydrocarbon to lower the refractive index. When a skeleton having three or more fused rings is used, examples include a phenanthroline ring, a benzoquinoline ring, a benzoisoquinoline ring, a benzoquinoxaline ring, a benzoquinazoline ring, a dibenzoquinoline ring, a dibenzoisoquinoline ring, a dibenzoquinoxaline ring, and a dibenzoquinazoline ring. When these polycyclic fused rings having three or more rings are used, they can be made into compounds with extremely high heat resistance, and are therefore suitable for use in the capping layer.

[0056] Furthermore, the presence of a ring having multiple nitrogen atoms (diazine ring, triazine ring, quinoxaline ring, or dibenzoquinoxaline ring) can enhance the effects of improving adhesion and reducing the refractive index described herein. A triazine ring is particularly preferred. An organic compound having an electron-transporting skeleton and a saturated hydrocarbon group may further have one or more aromatic rings (aromatic hydrocarbon rings or heteroaromatic hydrocarbon rings) in addition to the π-electron-deficient heteroaromatic ring. A triazine ring is more preferred as the electron-transporting skeleton because it has extremely high electron-transporting properties.

[0057] The saturated hydrocarbon group contained in the organic compound having a skeleton with electron transport properties and a saturated hydrocarbon group is preferably an alkyl group or an alicyclic group. Examples of the saturated hydrocarbon group include a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms or a substituted or unsubstituted alicyclic group having 3 to 10 carbon atoms. A branched alkyl group having 3 to 6 carbon atoms or an alicyclic group having 6 to 10 carbon atoms is preferred because it can achieve both a low refractive index and high carrier transport properties. A tert-butyl group or a cyclohexyl group is more preferred because it can achieve high heat resistance. A tert-butyl group is particularly preferred because it has high heat resistance and contributes to reducing the deposition temperature. The organic compound having a skeleton with electron transport properties and a saturated hydrocarbon group preferably has one or more saturated hydrocarbon groups. The organic compound having a skeleton with electron transport properties and a saturated hydrocarbon group preferably has 1 to 10, preferably 1 to 8, saturated hydrocarbon groups. In addition, the organic compound having a skeleton having electron transport properties and a saturated hydrocarbon group preferably has a ratio of the total number of carbon atoms forming bonds with sp3 hybrid orbitals of 10% to 60% of the total number of carbon atoms in the molecule.

[0058] As the organic compound having a skeleton with electron transport properties and a saturated hydrocarbon group, an organic compound having a triazine ring and an alkyl group is particularly preferable because it can achieve both high electron mobility and a low refractive index.

[0059] The organic compound having a skeleton with electron transport properties and a saturated hydrocarbon group preferably has an aromatic hydrocarbon group. The aromatic hydrocarbon group allows for a stable film with high heat resistance. The aromatic hydrocarbon group is preferably an aromatic hydrocarbon group having 6 to 30 carbon atoms, since it has high heat resistance and can prevent decomposition due to excessively high deposition temperatures. A group containing an uncondensed benzene ring is preferred for preventing excessively high deposition temperatures and achieving high electron mobility. The group containing an uncondensed benzene ring is preferably a substituted or unsubstituted phenyl group, a substituted or unsubstituted biphenyl group, or a substituted or unsubstituted terphenyl group. In the substituted or unsubstituted biphenyl group or substituted or unsubstituted terphenyl group, the benzene ring is preferably bonded at the meta position to reduce deposition temperatures, preferably at the para position to improve heat resistance, and preferably at the ortho position to form a bulky substituent, thereby reducing the refractive index.

[0060] By including a saturated hydrocarbon group (an alkyl group or an alicyclic group) in an organic compound having an electron-transporting skeleton and an electron-transporting skeleton, the refractive index of the organic compound having an electron-transporting skeleton and an electron-transporting hydrocarbon group can be reduced when the organic compound is formed into a thin film. Furthermore, the organic compound having an electron-transporting skeleton and an electron-transporting hydrocarbon group may have a structure in which multiple saturated hydrocarbon groups are bonded to one aromatic ring. Furthermore, when the organic compound having an electron-transporting skeleton and an electron-transporting hydrocarbon group has a benzene ring, the organic compound may have a structure in which multiple saturated hydrocarbon groups are bonded to one benzene ring. Having such a structure can enhance the refractive index reduction effect. Furthermore, when two or three saturated hydrocarbon groups are bonded to one benzene ring, it is preferable that the saturated hydrocarbon groups are located at the meta position relative to each other in order to achieve both a refractive index reduction effect and high mobility.

[0061] 1A and 1B show a light-emitting device having a laminated structure as an organic compound layer 103, which is made up of functional layers such as a hole injection layer 111, a hole transport layer 112, a light-emitting layer 113, an electron transport layer 114, and an electron injection layer 115, between a first electrode 101 and a second electrode 102 provided on an insulating layer. The organic compound layer preferably has a laminated structure made up of functional layers each containing an organic compound that is functionally separated and has properties according to its role, as shown in FIGS. 1A and 1B.

[0062] These functional layers are required to have a variety of functions, and representative functional layers include, for example, a carrier injection layer, a carrier transport layer, a light-emitting layer, a photoelectric conversion layer, a charge generation layer, a carrier blocking layer, an exciton blocking layer, etc. Each functional layer may also have other functions.

[0063] As described above, each functional layer is composed of an organic compound having properties corresponding to the function required for that layer. Therefore, the development of organic compounds having properties suitable for each functional layer has been actively pursued, and many organic compounds have been proposed and put to practical use.

[0064] 1A and 1B is a so-called top-emission light-emitting device that emits light from the second electrode 102 side. In this case, the light extraction efficiency can be improved by providing a cap layer 155 over the second electrode 102. Note that the light-emitting device of one embodiment of the present invention may be a dual-emission light-emitting device that emits light from both the first electrode 101 and the second electrode 102.

[0065] The capping layer 155 contains at least two or more substances. At least one of the organic compounds is preferably an organic compound having a skeleton with electron transport properties and a saturated hydrocarbon group. For example, it is more preferable that the capping layer 155 contains a first substance, which is an organic compound having a skeleton with electron transport properties and a saturated hydrocarbon group, and a second substance different from the first substance.

[0066] In one embodiment of the present invention, the cap layer 155 contains the first substance and the second substance, which provides a cap layer with high heat resistance and a highly stable cap layer because a vapor-deposited film with good film quality can be used as the cap layer. This makes it possible to provide a highly reliable device in an environment requiring high-temperature operation or high-temperature storage.

[0067] It is preferable that the plurality of substances contained in the cap layer 155 are all organic compounds, since this allows the cap layer to be formed by vacuum deposition continuously after the electrodes are formed.

[0068] In addition, when the capping layer 155 contains two substances, that is, when the capping layer 155 contains a first substance and a second substance, it is more preferable that the difference in the refractive index of ordinary light at 450 nm between the first substance and the second substance be 0.1 or more, preferably 0.2 or more, and more preferably 0.3 or more, in order to improve light extraction efficiency. The first substance, which is an organic compound having a skeleton with electron transport properties and a saturated hydrocarbon group, can be an organic compound with a low refractive index, which makes it easy to obtain a difference in refractive index between the first substance and the second substance.

[0069] Furthermore, as mentioned above, organic compounds having many saturated hydrocarbon groups have poor adhesion to electrodes, but organic compounds having a skeleton with electron transport properties and saturated hydrocarbon groups can have a low refractive index even if the number of saturated hydrocarbon groups is small, and therefore have good adhesion to electrodes.

[0070] 1B, the cap layer 155 preferably has a stacked structure, as shown in FIG. 1B, because this can further improve the light extraction efficiency. Although FIG. 1B shows a stack of two layers, a first layer 188 and a second layer 189, the cap layer 155 may have a stacked structure of more layers.

[0071] It is preferable that one of the first layer 188 and the second layer 189 contains the first substance and the other contains the second substance to improve light extraction efficiency. It is also preferable that the first layer 188 contains the first substance and the second layer 189 contains the second substance to further improve light extraction efficiency. As described above, organic compounds containing many saturated hydrocarbon groups have poor adhesion to electrodes. However, the first substance, which is an organic compound having a skeleton with electron transport properties and saturated hydrocarbon groups, can lower the refractive index even if the number of saturated hydrocarbon groups is small, and therefore has good adhesion to electrodes. Therefore, the inclusion of the first substance in the first layer 188 makes it possible to provide a light-emitting device with high reliability.

[0072] Furthermore, it is preferable that the first layer 188 contains a first substance, which is an organic compound having a skeleton with electron transport properties and a saturated hydrocarbon group, and the second layer 189 contains a second substance, because this makes it easier to lower the ordinary refractive index of the first layer than the ordinary refractive index of the second layer. That is, it is preferable that the first substance has a lower refractive index than the second substance. Specifically, it is preferable that the refractive index of a vapor-deposited film of the first substance for light of a certain wavelength is lower than the refractive index of a vapor-deposited film of the second substance for light of the same wavelength. More specifically, it is preferable that the ordinary refractive index of a vapor-deposited film of the first substance at any wavelength from 380 nm to 760 nm is lower than the ordinary refractive index of a vapor-deposited film of the second substance at that wavelength. Note that this difference is preferably 0.1 or more, more preferably 0.2 or more, and even more preferably 0.3 or more.

[0073] More specifically, it is preferable that the ordinary refractive index of the vapor-deposited film of the first substance at any wavelength from 380 nm to 500 nm is 1.80 or less, and that the ordinary refractive index of the vapor-deposited film of the second substance at any wavelength from 380 nm to 500 nm is 1.90 or more, and it is even more preferable that the ordinary refractive index of the vapor-deposited film of the first substance at any wavelength from 380 nm to 500 nm is 1.70 or less, and that the ordinary refractive index of the vapor-deposited film of the second substance at any wavelength from 380 nm to 500 nm is 2.00 or more, in order to improve light extraction efficiency.

[0074] Furthermore, it is preferable that the ordinary refractive index of the vapor-deposited film of the first substance at any wavelength from 500 nm to 600 nm is 1.72 or less, and the ordinary refractive index of the vapor-deposited film of the second substance at any wavelength from 500 nm to 600 nm is 1.90 or more, and it is even more preferable for the ordinary refractive index of the vapor-deposited film of the first substance at any wavelength from 500 nm to 600 nm to be 1.68 or less, and the ordinary refractive index of the vapor-deposited film of the second substance at any wavelength from 500 nm to 600 nm to be 1.93 or more, in order to improve light extraction efficiency.

[0075] Furthermore, it is preferable that the ordinary refractive index of the vapor-deposited film of the first substance at any wavelength from 600 nm to 760 nm is 1.70 or less, and that the ordinary refractive index of the vapor-deposited film of the second substance at any wavelength from 600 nm to 760 nm is 1.80 or more, and it is even more preferable for the ordinary refractive index of the vapor-deposited film of the first substance at any wavelength from 600 nm to 760 nm to be 1.65 or less, and that the ordinary refractive index of the vapor-deposited film of the second substance at any wavelength from 600 nm to 760 nm to be 1.85 or more, in order to improve light extraction efficiency.

[0076] It is preferable that the refractive index of the vapor-deposited film of the first substance at any wavelength from 380 nm to 760 nm is 1.40 or more, and it is more preferable that the refractive index of the vapor-deposited film of the second substance at any wavelength from 380 nm to 760 nm is 2.40 or less.

[0077] By stacking a layer containing a substance with a low refractive index and a layer containing a substance with a high refractive index, it becomes easier to extract light scattered within the light-emitting device, thereby improving the light-emitting efficiency of the light-emitting device. Note that, as described above, it is preferable that the layer containing the substance with a low refractive index (first substance) is the first layer 188 and the layer containing the substance with a high refractive index is the second layer 189, as this makes it easier to extract light. Furthermore, by using the layer containing the first substance as the first layer, the first substance, which has a relatively low evaporation temperature, can be deposited first, so that even if the evaporation temperature of the second substance is higher than that of the first substance, the thermal influence on the layer containing the organic compound can be reduced.

[0078] Furthermore, an organic compound having a skeleton with electron transport properties and a saturated hydrocarbon group can be an organic compound having a smaller refractive index than one that does not have the skeleton, because it has the hydrocarbon group.

[0079] More specifically, in order to improve light extraction efficiency, the refractive index of ordinary light in a vapor-deposited film of an organic compound having a skeleton with electron transport properties and a saturated hydrocarbon group at any wavelength from 380 nm to 500 nm is preferably 1.80 or less, and more preferably 1.70 or less.

[0080] Furthermore, in order to improve light extraction efficiency, the refractive index of ordinary light at any wavelength from 500 nm to 600 nm in a vapor-deposited film of an organic compound having a skeleton having electron transport properties and a saturated hydrocarbon group is preferably 1.72 or less, and more preferably 1.68 or less.

[0081] Furthermore, in order to improve light extraction efficiency, the refractive index of ordinary light at any wavelength from 600 nm to 760 nm in a vapor-deposited film of an organic compound having a skeleton with electron transport properties and a saturated hydrocarbon group is preferably 1.70 or less, and more preferably 1.65 or less.

[0082] The refractive index of the vapor-deposited film of the second substance for ordinary light at any wavelength from 380 nm to 760 nm is preferably 1.40 or more.

[0083] As the organic compound having a skeleton having electron transport properties and a saturated hydrocarbon group, an organic compound represented by the following general formula (G1) is preferable.

[0084]

[0085] In the above general formula (G1), Q １ ~Q ６ represents N (nitrogen atom) or C (carbon atom), and Q １ ~Q ６ 1 to 3 are N, and the remaining C is R １ n is any one of 1 to 5, and n R １ may be the same or different. １ each independently represents hydrogen (including deuterium), a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms, a substituted or unsubstituted alicyclic group having 3 to 10 carbon atoms, a substituted or unsubstituted aromatic hydrocarbon group having 6 to 30 carbon atoms, or a substituted or unsubstituted heteroaromatic hydrocarbon group having 1 to 30 carbon atoms.

[0086] In the general formula (G1), n ​​R １ At least one or n R １ At least one of the substituents contained in the group is preferably a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms or a substituted or unsubstituted alicyclic group having 3 to 10 carbon atoms.

[0087] In the general formula (G1), when n is 2 or more, a plurality of R １ In that case, general formula (G1) has a structure containing a fused ring such as a quinoline ring, a quinazoline ring, a quinoxaline ring, a benzoquinoxaline ring, a dibenzoquinoxaline ring, a benzoquinazoline ring, or a dibenzoquinazoline ring.

[0088] Further, an example of an organic compound having a skeleton having electron-transporting properties and a saturated hydrocarbon group is an organic compound represented by General Formula (G2).

[0089]

[0090] In the general formula (G2), A represents a substituted or unsubstituted heteroaromatic ring, which may be a monocyclic or fused ring; R ０ ~R １５ each independently represents any one of hydrogen (including deuterium), a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms, a substituted or unsubstituted alicyclic group having 3 to 10 carbon atoms, a substituted or unsubstituted aromatic hydrocarbon group having 6 to 30 carbon atoms, a substituted or unsubstituted heteroaromatic hydrocarbon group having 1 to 30 carbon atoms, and a group represented by general formula (G2-1).

[0091] In the above general formula (G2) or general formula (G2-1), R ０ ~R １５ At least one of or R ０ ~R １５ At least one of the substituents contained in the group is preferably a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms or a substituted or unsubstituted alicyclic group having 3 to 10 carbon atoms.

[0092] In general formula (G2), A is preferably any one of a pyridine ring, a pyrimidine ring, a pyrazine ring, a pyridazine ring, a triazine ring, a quinoline ring, a quinazoline ring, a quinoxaline ring, a benzoquinoxaline ring, a dibenzoquinoxaline ring, a benzoquinazoline ring, and a dibenzoquinazoline ring, and among the pyridine ring, a pyrimidine ring, a pyrazine ring, a pyridazine ring, and a triazine ring, a triazine ring is particularly preferable.

[0093] In addition, in the general formula (G2), R ０ ~R １５ is hydrogen (including deuterium), a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms, or a substituted or unsubstituted alicyclic group having 3 to 10 carbon atoms, R ２ and R ４ is preferably an alkyl group or an alicyclic group, and R １ , R ３ and R ５ is preferably hydrogen (including deuterium). In this case, R ２ and R ４are located at the meta position relative to each other or at the meta position relative to A, and therefore steric hindrance can be reduced compared to when the substituents are bonded to adjacent carbons or when they are located at the ortho position relative to A, resulting in a stable molecular structure, which is preferable from the viewpoint of reliability. Furthermore, such a molecular structure makes synthesis easy or possible, increasing the synthesis yield, which is preferable from the viewpoint of reducing synthesis costs or achieving high purity of the target product, and enabling improved reliability. Similarly, R ６ , R ８ and R １０ is preferably hydrogen (including deuterium). １１ , R １３ and R １５ is preferably hydrogen (including deuterium).

[0094] In the above general formula (G2), R ０ ~R １５ is any one of hydrogen (including deuterium), a substituted or unsubstituted aromatic hydrocarbon group having 6 to 30 carbon atoms, a substituted or unsubstituted heteroaromatic hydrocarbon group having 1 to 30 carbon atoms, or a group represented by general formula (G2-1), a substituent other than hydrogen (including deuterium) may have a structure bonded to an adjacent carbon atom.

[0095] In addition, in the general formula (G1) or general formula (G2), R ０ ~R １５ At least one of the above may be a group represented by the following formula (G2-2).

[0096]

[0097] In the general formula (G2-2), α represents a substituted or unsubstituted benzene ring or a substituted or unsubstituted biphenyl skeleton. ２０represents a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms, a substituted or unsubstituted alicyclic group having 3 to 10 carbon atoms, a substituted or unsubstituted aromatic hydrocarbon group having 6 to 30 carbon atoms, or a substituted or unsubstituted heteroaromatic group having 1 to 30 carbon atoms. m represents 0 to 2. n represents 1 or 4. When m is 2, the multiple α's may be the same or different. When n is 2 or more, the multiple R ２０ may be the same or different. When α is a benzene ring having a substituent, the substituent is preferably located at the meta position relative to other groups bonded to the benzene ring. When n is 2, two R ２０ are preferably located in the meta position relative to each other.

[0098] Furthermore, when the benzene ring or biphenyl skeleton has a substituent, examples of the substituent include a substituted or unsubstituted alkyl group having 1 to 4 carbon atoms, a substituted or unsubstituted alicyclic group having 3 to 6 carbon atoms, or a substituted or unsubstituted aromatic hydrocarbon group having 6 to 13 carbon atoms.

[0099] R in the above general formula (G2) ２ and R ４ It is preferable that either one or both of R is a group represented by general formula (G2-2). ２ and R ４ and R are groups represented by (G2-2) above. ２ and R ４ may be the same or different.

[0100] In the general formula (G2-2), specific examples of α include the following formulae (α-1) to (α-14): In the following formulae (α-1) to (α-14), * represents a bond.

[0101]

[0102] In addition, in the general formula (G1), the general formula (G2), the general formula (G2-1), or the general formula (G2-2), R ０ ~R １５ , R ２０ , R ０ ~R １５and R ２０ Preferably, at least one of the substituents is independently any one of a substituted or unsubstituted phenyl group, a substituted or unsubstituted naphthyl group, a substituted or unsubstituted phenanthryl group, and a substituted or unsubstituted fluorenyl group. When these substituents are combined, the effective conjugation length becomes short wavelength, making it possible to design a molecule that does not absorb in the visible light region, which is effective in improving the extraction efficiency. Note that when the phenyl group, naphthyl group, phenanthryl group, or fluorenyl group has a substituent, examples of the substituent include an alkyl group having 1 to 4 carbon atoms, an alicyclic group having 3 to 6 carbon atoms, or an aromatic hydrocarbon group having 6 to 13 carbon atoms.

[0103] Also, R ０ ~R １５ , R ２０ , R ０ ~R １５ and R ２０In order to reduce the refractive index, at least one of the substituents is preferably a heteroaromatic ring or a heteroaromatic ring group containing nitrogen as an element forming a substituted or unsubstituted ring, more preferably a heteroaromatic ring or a heteroaromatic ring group having 2 or more nitrogen atoms, and even more preferably a heteroaromatic ring or a heteroaromatic ring group having 3 or more nitrogen atoms. Specific examples of the skeleton of the heteroaromatic ring or heteroaromatic ring group include pyridine, pyrazine, pyrimidine, pyridazine, 1,2,3-triazine, 1,2,4-triazine, 1,3,5-triazine, quinoline, quinazoline, quinoxaline, benzoquinoxaline, dibenzoquinoxaline, benzoquinazoline, and dibenzoquinazoline. When the layer is used in common with the electron-transporting layer or the electron-injecting layer, a pyridine skeleton is preferred. The heteroaromatic ring or heteroaromatic ring group preferably has one or more saturated hydrocarbon groups, and when used in common with an electron transport layer or an electron injection layer, it preferably has a methyl group to enhance electron injection and transport properties. A particularly preferred structure is a pyridine skeleton having one or more methyl groups. When the pyridine skeleton has a substituent, the substituent can be an alkyl group having 1 to 4 carbon atoms, an alicyclic group having 3 to 6 carbon atoms, or an aromatic hydrocarbon group having 6 to 13 carbon atoms.

[0104] Also, R ０ ~R １５ , R ２０ , R ０ ~R １５ and R ２０ Specific examples of the substituents that may be possessed by the group include the following formulae (r-1) to (r-20): In the following formulae (r-1) to (r-20), * represents a bond.

[0105]

[0106] As in formulas (r-1), (r-2), (r-5), and (r-6), an alkyl group or an alicyclic group bonded to the meta position of a phenyl group is preferred because it reduces the film density and refractive index compared to when bonded to the para and ortho positions. Furthermore, as in formulas (r-5) and (r-6), when there are two alkyl groups and / or two alicyclic groups per phenyl group, the total number of carbon atoms forming bonds via sp3 hybrid orbitals can be easily increased, reducing synthesis costs and making it more preferable. Furthermore, as in formulas (r-19) and (r-20), when a pyridyl group is included, the ring-forming element contains nitrogen, which lowers the refractive index compared to an all-carbon aromatic ring, making it preferable. Furthermore, when used in combination with an electron transport layer or electron injection layer, it is preferable to have a methyl group because it enhances electron injection and transport properties. A particularly preferred configuration is a pyridine skeleton having one or more methyl groups.

[0107] All hydrogen atoms may be deuterium atoms, and the aromatic hydrocarbon group and heteroaromatic hydrocarbon group may have a structure in which multiple rings are bonded to each other. When the group is composed of multiple rings, there may be multiple aromatic hydrocarbon groups, multiple heteroaromatic hydrocarbon groups, or both aromatic and heteroaromatic hydrocarbon groups.

[0108] Note that all hydrogen atoms in the organic compounds represented by General Formula (G1) and General Formula (G2) may each independently be deuterium atoms.

[0109] In the above general formula (G1) and general formula (G2), examples of the skeleton constituting the aromatic hydrocarbon group having 6 to 30 carbon atoms include benzene, biphenyl, naphthalene, phenylnaphthalene, terphenyl, fluorene, 9,9-dimethylfluorene, quaterphenyl, spirobifluorene, phenanthrene, anthracene, phenylbinaphthalene, fluoranthene, triphenylene, etc., and a monovalent group obtained by removing one hydrogen atom from these skeletons becomes an aromatic hydrocarbon group having 6 to 30 carbon atoms. Note that, among the above skeletons, a skeleton consisting of multiple rings may form a bond at any position of the ring, and further, a carbon at any position of these skeletons may form a bond as a substituent. When the aromatic hydrocarbon group having 6 to 30 carbon atoms has a substituent, examples of the substituent include an alkyl group having 1 to 4 carbon atoms, an alicyclic group having 3 to 6 carbon atoms, and an aromatic hydrocarbon group having 6 to 13 carbon atoms. Preferred examples of the skeleton having a substituent include methylbenzene, dimethylbenzene, trimethylbenzene, dimethylfluorene, diphenylfluorene, and diphenylanthracene.

[0110] In addition, in the above general formula (G1) and general formula (G2), specific examples of the heteroaromatic group having 1 to 30 carbon atoms include a 1,3,5-triazin-yl group, a 1,2,4-triazin-yl group, a pyrimidin-yl group, a pyrazin-yl group, a pyridyl group, a carbazolyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a benzonaphthofuranyl group, a benzonaphthothiophenyl group, a dinaphthofuranyl group, a dinaphthothiophenyl group, an indolocarbazolyl group, a benzofurocarbazolyl group, a benzothienocarbazolyl group, an indenocarbazolyl group, a dibenzocarbazolyl group, an indolyl group, a pyrrolyl group, a 1,2,3-triazol-yl group, and a 1,2,4-triazol-yl group. When the heteroaromatic hydrocarbon group having 1 to 30 carbon atoms has a substituent, examples of the substituent include an alkyl group having 1 to 4 carbon atoms, an alicyclic group having 3 to 6 carbon atoms, and an aromatic hydrocarbon group having 6 to 13 carbon atoms.

[0111] Examples of the alkyl group having 1 to 6 carbon atoms include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a sec-butyl group, an isobutyl group, a tert-butyl group, a pentyl group, an isopentyl group, a sec-pentyl group, a tert-pentyl group, a neopentyl group, a hexyl group, an isohexyl group, a 3-methylpentyl group, a 2-methylpentyl group, a 2-ethylbutyl group, a 1,2-dimethylbutyl group, a 2,3-dimethylbutyl group, and a 1-ethylpropyl group. When the alkyl group having 1 to 6 carbon atoms has a substituent, the substituent can be an alicyclic group having 3 to 6 carbon atoms, or an aromatic hydrocarbon group having 6 to 13 carbon atoms.

[0112] Furthermore, the alicyclic group having 3 to 10 carbon atoms is preferably a cycloalkyl group, and specific examples thereof include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, a cyclononanyl group, a cyclodecanyl group, an adamantyl group, a bicyclo[2.2.1]heptyl group, a tricyclo[5.2.1.0(2,6)]decanyl group, a noradamantyl group, a 1-methylcyclohexyl group, a bicyclo[2,2,2]octyl group, a norbornanyl group, etc. When the alicyclic group having 3 to 10 carbon atoms has a substituent, the substituent can be an alkyl group having 1 to 4 carbon atoms, an alicyclic group having 3 to 6 carbon atoms, or an aromatic hydrocarbon group having 6 to 13 carbon atoms.

[0113] Specific examples of the organic compound having a skeleton having electron transport properties and a saturated hydrocarbon group, which has the above-described structure, are preferably organic compounds represented by the following structural formulas (100) to (129), structural formulas (200) to (223), structural formulas (300) to (317), structural formulas (400) to (435), and structural formulas (450) to (456).

[0114]

[0115]

[0116]

[0117]

[0118]

[0119]

[0120]

[0121]

[0122]

[0123]

[0124]

[0125]

[0126]

[0127]

[0128]

[0129]

[0130]

[0131]

[0132]

[0133] As described above, the cap layer 155 is a layer containing a first substance and a second substance. The first substance is an organic compound having a skeleton with electron transport properties and a saturated hydrocarbon group. The second substance is a substance different from the organic compound having a skeleton with electron transport properties and a saturated hydrocarbon group.

[0134] The second substance may be an organic compound, as described below, or an inorganic compound such as silicon nitride or ITO (indium tin oxide), but is preferably an organic compound (hereinafter, this organic compound will also be referred to as the second organic compound). It is preferable to use an organic compound with a higher ordinary refractive index than an organic compound having a skeleton with electron transport properties and a saturated hydrocarbon group as the second organic compound. This can further improve the efficiency of the light-emitting device.

[0135] Note that it is preferable that the difference in ordinary refractive index between the organic compound having a skeleton with electron transport properties and a saturated hydrocarbon group and the second organic compound at any wavelength from 380 nm to 760 nm is 0.1 or more, preferably 0.2 or more, and more preferably 0.3 or more, since this can further improve the efficiency of the light-emitting device.

[0136] More specifically, the second organic compound preferably has an ordinary light refractive index of 1.90 or more at any wavelength from 380 nm to 500 nm in the vapor-deposited film, and more preferably 2.00 or more in order to improve light extraction efficiency.

[0137] Alternatively, the second organic compound preferably has an ordinary refractive index of 1.90 or more at any wavelength from 500 nm to 600 nm in the vapor-deposited film, and more preferably 1.93 or more in order to improve light extraction efficiency.

[0138] Alternatively, the second organic compound preferably has an ordinary refractive index of 1.80 or more in the vapor-deposited film at any wavelength from 600 nm to 760 nm, and more preferably 1.85 or more, in order to improve light extraction efficiency.

[0139] The vapor-deposited film of the second organic compound preferably has an ordinary refractive index of 2.40 or less for light having a wavelength of 380 nm to 760 nm.

[0140] Preferred examples of organic compounds that can be used as the second organic compound include organic compounds having an electron-deficient heterocycle represented by the following structural formulas (500) to (566), amine compounds having an electron-deficient heterocycle represented by the following structural formulas (600) to (603), amine compounds represented by the following structural formulas (700) to (729), anthracene compounds represented by the following structural formulas (800) to (814), anthracene compounds having a heterocycle represented by the following structural formulas (900) to (907), and organic compounds represented by the following structural formulas (908) to (909). Thin films of these compounds exhibit a high refractive index in the visible light region, do not absorb light in the visible light region, and have a high Tg of 115° C. or higher, and therefore can be suitably used as the second organic compound. In particular, amine compounds represented by the following structural formulas (700) to (729), anthracene compounds represented by the following structural formulas (800) to (814), anthracene compounds having a heterocycle represented by the following structural formulas (900) to (907), and organic compounds represented by the following structural formulas (908) to (909) can be preferably used because they do not have an electron-deficient heterocycle and therefore have a high LUMO level, suppress interaction with adjacent layers such as electrodes and passive films, and provide a cap film with stable film quality. Note that organic compounds or inorganic compounds other than these can also be used.

[0141]

[0142]

[0143]

[0144]

[0145]

[0146]

[0147]

[0148]

[0149]

[0150]

[0151]

[0152]

[0153]

[0154]

[0155] The structure described in this embodiment mode can be used in appropriate combination with structures described in other embodiments.

[0156] Information such as the layer structure of the cap layer 155, the molecular weight of the contained substances, and the number of contained substances can be obtained by using time-of-flight secondary ion mass spectrometry (ToF-SIMS). In this case, depending on the film thickness of the cap layer or the measurement conditions, even if the cap layer has a layer structure of a layer containing a first substance and a layer containing a second substance, it may be detected as a mixed layer.

[0157] This embodiment mode can be used in any combination with other embodiments.

[0158] Embodiment 2 In this embodiment, a light-emitting device according to one embodiment of the present invention will be described in detail. FIG. 1A illustrates a light-emitting device according to one embodiment of the present invention. The light-emitting device according to one embodiment of the present invention includes an organic compound layer 103 between a first electrode 101 formed over an insulating layer and a second electrode 102 facing the first electrode, and includes a cap layer 155 over the second electrode 102.

[0159] The organic compound layer 103 includes at least the light-emitting layer 113 and may further include other functional layers. Although FIGS. 1A and 1B illustrate an example in which the hole-injection layer 111, the hole-transport layer 112, and the electron-transport layer 114 (and the electron-injection layer 115) are included, the organic compound layer 103 may also include an exciton blocking layer, a charge-generating layer, or the like. Note that the hole-transport layer 112, which is in contact with the light-emitting layer 113, may be particularly referred to as an electron-blocking layer, and the electron-transport layer 114, which is in contact with the light-emitting layer, may be particularly referred to as a hole-blocking layer. In this embodiment, the first electrode 101 functions as an anode and the second electrode 102 functions as a cathode. However, the second electrode 102 transmits visible light, and the light-emitting device of one embodiment of the present invention is a so-called top-emission light-emitting device.

[0160] The configuration of the cap layer 155 has been described in detail in the first embodiment, so a repetitive description will be omitted. Please refer to the first embodiment.

[0161] The anode is preferably formed using a metal, alloy, conductive compound, or mixture thereof having a large work function (specifically, 4.0 eV or more). Specific examples include indium oxide-tin oxide (ITO), indium oxide-tin oxide containing silicon or silicon oxide (ITSO), indium oxide-zinc oxide, and indium oxide containing tungsten oxide and zinc oxide (IWZO). These conductive metal oxide films are usually formed by sputtering, but may also be formed by applying a sol-gel method. As an example of a fabrication method, indium oxide-zinc oxide can be formed by sputtering using a target in which 1 to 20 wt % of zinc oxide is added to indium oxide. Indium oxide containing tungsten oxide and zinc oxide (IWZO) can also be formed by sputtering using a target containing 0.5 to 5 wt % tungsten oxide and 0.1 to 1 wt % zinc oxide relative to indium oxide. Other materials that can be used for the anode include, for example, gold (Au), platinum (Pt), nickel (Ni), tungsten (W), chromium (Cr), molybdenum (Mo), iron (Fe), cobalt (Co), copper (Cu), palladium (Pd), titanium (Ti), aluminum (Al), or nitrides of metal materials (e.g., titanium nitride). A layer formed by stacking these materials can also be used as the anode. For example, a film formed by stacking Al, Ti, and ITSO on Ti in this order is preferred because it has good reflectivity, is highly efficient, and enables high resolution of several thousand ppi. Graphene can also be used as the anode material. In addition, by using a composite material capable of forming the hole injection layer 111 described later as a layer in contact with the anode (typically, a hole injection layer), it becomes possible to select an electrode material regardless of the work function.

[0162] The hole injection layer 111 is provided in contact with the anode and has a function of facilitating injection of holes into the organic compound layer 103. The hole injection layer 111 is made of phthalocyanine (abbreviation: H ２The organic EL element can be formed from a phthalocyanine compound or complex compound such as copper phthalocyanine (abbreviated as CuPc), 4,4'-bis[N-(4-diphenylaminophenyl)-N-phenylamino]biphenyl (abbreviated as DPAB) or 4,4'-bis(N-{4-[N'-(3-methylphenyl)-N'-phenylamino]phenyl}-N-phenylamino)biphenyl (abbreviated as DNTPD), or a polymer such as poly(3,4-ethylenedioxythiophene) / polystyrene sulfonic acid (abbreviated as PEDOT / PSS).

[0163] The hole-injection layer 111 may be formed using a substance having electron acceptor properties. Examples of the substance having acceptor properties include organic compounds having an electron-withdrawing group (such as a halogen group or a cyano group), such as 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-TCCNNQ), and 2-(7-dicyanomethylene-1,3,4,5,6,8,9,10-octafluoro-7H-pyren-2-ylidene)malononitrile. In particular, compounds in which an electron-withdrawing group is bonded to a fused aromatic ring having a plurality of heteroatoms, such as HAT-CN, are thermally stable and preferred. Also, [3]radialene derivatives having an electron-withdrawing group (especially a halogen group such as a fluoro group, a cyano group, etc.) are preferred because they have very high electron-accepting properties, and specific examples thereof include α,α',α''-1,2,3-cyclopropanetriylidenetris[4-cyano-2,3,5,6-tetrafluorobenzeneacetonitrile], α,α',α''-1,2,3-cyclopropanetriylidenetris[2,6-dichloro-3,5-difluoro-4-(trifluoromethyl)benzeneacetonitrile], and α,α',α''-1,2,3-cyclopropanetriylidenetris[2,3,4,5,6-pentafluorobenzeneacetonitrile]. As the substance having acceptor properties, in addition to the organic compounds described above, transition metal oxides such as molybdenum oxide, vanadium oxide, ruthenium oxide, tungsten oxide, and manganese oxide can be used. ２The hole injection layer 111 can also be formed from a phthalocyanine compound or complex compound such as copper phthalocyanine (abbreviated as CuPc), aromatic amine compounds such as 4,4'-bis[N-(4-diphenylaminophenyl)-N-phenylamino]biphenyl (abbreviated as DPAB) or 4,4'-bis(N-{4-[N'-(3-methylphenyl)-N'-phenylamino]phenyl}-N-phenylamino)biphenyl (abbreviated as DNTPD), or a polymer such as poly(3,4-ethylenedioxythiophene) / polystyrene sulfonic acid (abbreviated as PEDOT / PSS). A substance having acceptor properties can extract electrons from an adjacent hole transport layer (or hole transport material) when an electric field is applied.

[0164] The hole-injection layer 111 is preferably formed using a composite material containing the above-described material having an acceptor property and a substance having a hole-transport property.

[0165] As a substance having a hole transport property used in the composite material, various organic compounds such as aromatic amine compounds, heteroaromatic compounds, aromatic hydrocarbons, and polymer compounds (oligomers, dendrimers, polymers, etc.) can be used. −６ cm ２ / Vs or more. The substance having hole transport properties used in the composite material is preferably a compound having a fused aromatic hydrocarbon ring or a π-electron-rich heteroaromatic ring. As the fused aromatic hydrocarbon ring, an anthracene ring, a naphthalene ring, or the like is preferable. As the π-electron-rich heteroaromatic ring, a fused aromatic ring containing at least one of a pyrrole skeleton, a furan skeleton, and a thiophene skeleton in the ring is preferable, and specifically, a carbazole ring, a dibenzothiophene ring, or a ring in which an aromatic ring or a heteroaromatic ring is further fused to the above ring is preferable.

[0166] Such a substance having hole-transporting properties preferably has at least one of a carbazole skeleton, a dibenzofuran skeleton, a dibenzothiophene skeleton, and an anthracene skeleton. In particular, the substance may be an aromatic amine having a substituent containing a dibenzofuran ring or a dibenzothiophene ring, an aromatic monoamine having a naphthalene ring, or an aromatic monoamine in which a 9-fluorenyl group is bonded to the nitrogen of the amine via an arylene group. It is preferable that the substance having hole-transporting properties is a substance having an N,N-bis(4-biphenyl)amino group, since this allows the manufacture of a light-emitting device with a long lifetime.

[0167] Specific examples of the substance having the hole transport property as described above include N-(4-biphenyl)-6,N-diphenylbenzo[b]naphtho[1,2-d]furan-8-amine (abbreviation: BnfABP), N,N-bis(4-biphenyl)-6-phenylbenzo[b]naphtho[1,2-d]furan-8-amine (abbreviation: BBABnf), 4,4′-bis(6-phenylbenzo[b]naphtho[1,2-d]furan-8-yl)-4″-phenyltriphenylamine (abbreviation: BnfBB1BP), N,N-bis(4-biphenyl)benzo[b]naphtho[1 ,2-d]furan-6-amine (abbreviation: BBABnf(6)), N,N-bis(4-biphenyl)benzo[b]naphtho[1,2-d]furan-8-amine (abbreviation: BBABnf(8)), N,N-bis(4-biphenyl)benzo[b]naphtho[2,3-d]furan-4-amine (abbreviation: BBABnf(II)(4)), N,N-bis[4-(dibenzofuran-4-yl)phenyl]-4-amino-p-terphenyl (abbreviation: DBfBB1TP), N-[4-(dibenzothiophen-4-yl)phenyl]-N-phenyl-4-biphenylamine amine (abbreviation: ThBA1BP), 4-(2-naphthyl)-4',4''-diphenyltriphenylamine (abbreviation: BBAβNB), 4-[4-(2-naphthyl)phenyl]-4',4''-diphenyltriphenylamine (abbreviation: BBAβNBi), 9,9'-[6-(biphenyl-4-yl)-2-phenyl-1,3,5-triazine-4,3''-diyl]bis(9H-carbazole) (abbreviation: BBAαNβNB), 9,9'-[6-(biphenyl-4-yl)-2-phenyl-1,3,5-triazine-4,3''-diyl]bis( 9H-carbazole) (abbreviation: BBAαNβNB-03), 4,4′-diphenyl-4″-(7-phenyl)naphthyl-2-yltriphenylamine (abbreviation: BBAPβNB-03), 9,9′-[6-(biphenyl-4-yl)-2-phenyl-1,3,5-triazine-4,3″-diyl]bis(9H-carbazole) (abbreviation: BBA(βN2)B), 4,4′-diphenyl-4″-([2,2′-binaphthyl]-7-yl)triphenylamine (abbreviation: BBA(βN2)B-03), 4,4′-diphenyl-4″-([1,2'-binaphthyl]-4-yl)triphenylamine (abbreviation: BBAβNαNB), 4,4'-diphenyl-4''-([1,2'-binaphthyl]-5-yl)triphenylamine (abbreviation: BBAβNαNB-02), 4-(4-biphenylyl)-4'-(2-naphthyl)-4''-phenyltriphenylamine (abbreviation: TPBiAβNB), 4-(3-biphenylyl)-4'-[4-(2-naphthyl)phenyl]-4''-phenyltriphenylamine (abbreviation: mTPBiAβNBi ), 4-(4-biphenylyl)-4'-[4-(2-naphthyl)phenyl]-4''-phenyltriphenylamine (abbreviation: TPBiAβNBi), 4-phenyl-4'-(1-naphthyl)triphenylamine (abbreviation: αNBA1BP), 4,4'-bis(1-naphthyl)triphenylamine (abbreviation: αNBB1BP), 4,4'-diphenyl-4''-[4'-(carbazol-9-yl)biphenyl-4-yl]triphenylamine (abbreviation: YGTBi1BP), 4'-[4-(3- N-[4-(9-phenyl-9H-carbazol-9-yl)phenyl]tris(biphenyl-4-yl)amine (abbreviation: YGTBi1BP-02), 4-[4'-(carbazol-9-yl)biphenyl-4-yl]-4'-(2-naphthyl)-4''-phenyltriphenylamine (abbreviation: YGTBiβNB), N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-N-[4-(1-naphthyl)phenyl]-9,9'-spirobi[9H-fluorene]-2-amine (abbreviation: PC BNBSF), N,N-bis(biphenyl-4-yl)-9,9'-spirobi[9H-fluorene]-2-amine (abbreviation: BBASF), N,N-bis(biphenyl-4-yl)-9,9'-spirobi[9H-fluorene]-4-amine (abbreviation: BBASF(4)), N-(biphenyl-2-yl)-N-(9,9-dimethyl-9H-fluoren-2-yl)-9,9'-spirobi[9H-fluorene]-4-amine (abbreviation: oFBiSF), N-(biphenyl-4-yl)-N-(9,9-dimethyl-9H-fluoren-2-yl)dibenzofuran-4-amine (abbreviation: FrBiF), N-[4-(1-naphthyl)phenyl]-N-[3-(6-phenyldibenzofuran-4-yl)phenyl]-1-naphthylamine (abbreviation: mPDBfBNBN), 4-phenyl-4'-(9-phenylfluoren-9-yl)triphenylamine (abbreviation: BPAFLP), 4-phenyl-3'-(9-phenylfluoren-9-yl)triphenylamine (abbreviation: mBPAFLP), 4-phenyl-4' -[4-(9-phenylfluoren-9-yl)phenyl]triphenylamine (abbreviation: BPAFLBi), 4-phenyl-4'-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBA1BP), 4,4'-diphenyl-4''-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBBi1BP), 4-(1-naphthyl)-4'-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBANB), 4,4'- Di(1-naphthyl)-4"-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBNBB), N-phenyl-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-9,9'-spirobi[9H-fluorene]-2-amine (abbreviation: PCBASF), N-(biphenyl-4-yl)-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-9,9-dimethyl-9H-fluorene-2-amine (abbreviation: PCBBiF), N,N-bis( 9,9-dimethyl-9H-fluoren-2-yl)-9,9′-spirobi-9H-fluoren-4-amine, N,N-bis(9,9-dimethyl-9H-fluoren-2-yl)-9,9′-spirobi-9H-fluoren-3-amine, N,N-bis(9,9-dimethyl-9H-fluoren-2-yl)-9,9′-spirobi-9H-fluoren-2-amine, N,N-bis(9,9-dimethyl-9H-fluoren-2-yl)-9,9′-spirobi-9H-fluoren-1-amine, etc.

[0168] Other aromatic amine compounds that can be used as the substance having hole-transporting properties include N,N'-di(p-tolyl)-N,N'-diphenyl-p-phenylenediamine (abbreviation: DTDPPA), 4,4'-bis[N-(4-diphenylaminophenyl)-N-phenylamino]biphenyl (abbreviation: DPAB), 4,4'-bis(N-{4-[N'-(3-methylphenyl)-N'-phenylamino]phenyl}-N-phenylamino)biphenyl (abbreviation: DNTPD), and 1,3,5-tris[N-(4-diphenylaminophenyl)-N-phenylamino]benzene (abbreviation: DPA3B).

[0169] By forming the hole injection layer 111, the hole injection property becomes good, and a light emitting device with a low driving voltage can be obtained.

[0170] Among substances having acceptor properties, organic compounds having acceptor properties are easy to use because they can be easily vapor-deposited and formed into a film.

[0171] The hole transport layer 112 is formed by including a substance having a hole transport property. −６ cm ２ It is preferable that the material has a hole mobility of 1.0 V or more.

[0172] Examples of the substance having a hole-transporting property include 4,4′-bis[N-(1-naphthyl)-N-phenylamino]biphenyl (abbreviation: NPB), N,N′-diphenyl-N,N′-bis(3-methylphenyl)-4,4′-diaminobiphenyl (abbreviation: TPD), N,N′-bis(9,9′-spirobi[9H-fluoren]-2-yl)-N,N′-diphenyl-4,4′-diaminobiphenyl (abbreviation: BSPB), 4-phenyl-4′-(9-phenylfluoren-9-yl)triphenylamine (abbreviation: BPAFLP), and 4-phenyl-3′- (9-Phenylfluoren-9-yl)triphenylamine (abbreviation: mBPAFLP), 4-phenyl-4'-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBA1BP), 4,4'-diphenyl-4''-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBBi1BP), 4-(1-naphthyl)-4'-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBANB), 4,4'-di(1-naphthyl)-4''-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBANB), compounds having an aromatic amine skeleton such as 9,9-dimethyl-N-phenyl-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]fluoren-2-amine (abbreviation: PCBAF), and N-phenyl-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-9,9'-spirobi[9H-fluorene]-2-amine (abbreviation: PCBASF); 1,3-bis(N-carbazolyl)benzene (abbreviation: mCP); 4,4'-di(N-carbazol-3-yl)triphenylamine (abbreviation: PCBNBB); 9,9'-bis(biphenyl-4-yl)-3,3'-bi-9H-carbazole (abbreviation: BisBPCz), 9,9'-bis(biphenyl-3-yl)-3,3'-bi-9H-carbazole (abbreviation: BismBPCz), 9-(biphenyl-3-yl)-9'-(biphenyl-4-yl)-9H,9'H-3,3'-Bicarbazole (abbreviation: mBPCCBP), 9-(2-naphthyl)-9'-phenyl-3,3'-bi-9H-carbazole (abbreviation: βNCCP), 9-(3-biphenyl)-9'-(2-naphthyl)-3,3'-bi-9H-carbazole (abbreviation: βNCCmBP), 9-(4-biphenyl)-9'-(2-naphthyl)-3,3'-bi-9H-carbazole (abbreviation: βNCCBP), 9,9'-di-2-naphthyl-3,3'-9H,9'H-bicarbazole (abbreviation: BisβNCz), 9-(2-naphthyl)-9'-[1,1':4',1"-terf phenyl]-3-yl-3,3'-9H,9'H-bicarbazole, 9-(2-naphthyl)-9'-[1,1':3',1"-terphenyl]-3-yl-3,3'-9H,9'H-bicarbazole, 9-(2-naphthyl)-9'-[1,1':3',1"-terphenyl]-5'-yl-3,3'-9H,9'H-bicarbazole, 9-(2-naphthyl)-9'-[1,1':4',1"-terphenyl]-4-yl-3,3'-9H,9'H-bicarbazole, 9-(2-naphthyl)-9'-[1,1':3',1"-terphenyl]-4-yl-3,3 9-(4-biphenyl)-9'-(triphenylen-2-yl)-3,3'-9H,9'H-bicarbazole, 9-(2-naphthyl)-9'-(triphenylen-2-yl)-3,3'-9H,9'H-bicarbazole, 9-phenyl-9'-(triphenylen-2-yl)-3,3'-9H,9'H-bicarbazole (abbreviation: PCCzTp), 9,9'-bis(triphenylen-2-yl)-3,3'-9H,9'H-bicarbazole, 9-(4-biphenyl)-9'-(triphenylen-2-yl)-3,3'-9H,9'H-bicarbazole, 9-(triphenylen-2-yl)-9'-[1,1':3',1"-taphene compounds having a carbazole skeleton such as 4,4',4''-(benzene-1,3,5-triyl)tri(dibenzothiophene) (abbreviation: DBT3P-II), 2,8-diphenyl-4-[4-(9-phenyl-9H-fluoren-9-yl)phenyl]dibenzothiophene (abbreviation: DBTFLP-III), and 4-[4-(9-phenyl-9H-fluoren-9-yl)phenyl]-6-phenyldibenzothiophene (abbreviation: DBTFLP-IV);Examples of compounds having a furan skeleton include 4',4''-(benzene-1,3,5-triyl)tri(dibenzofuran) (abbreviation: DBF3P-II) and 4-{3-[3-(9-phenyl-9H-fluoren-9-yl)phenyl]phenyl}dibenzofuran (abbreviation: mmDBFFLBi-II). Among the above, compounds having an aromatic amine skeleton and compounds having a carbazole skeleton are preferred because they have good reliability, high hole-transport properties, and contribute to reducing driving voltage. In addition, the organic compounds listed as substances having hole-transport properties used in the composite material of the hole-injection layer 111 can also be suitably used as materials for the hole-transport layer 112.

[0173] The luminescent center substance contained in the light-emitting layer 113 may be a fluorescent substance, a phosphorescent substance, a substance exhibiting thermally activated delayed fluorescence (TADF), or any other luminescent substance.

[0174] Examples of materials that can be used as the fluorescent substance in the light-emitting layer 113 include the following: In addition, fluorescent substances other than these can also be used.

[0175] 5,6-bis[4-(10-phenyl-9-anthryl)phenyl]-2,2'-bipyridine (abbreviation: PAP2BPy), 5,6-bis[4'-(10-phenyl-9-anthryl)biphenyl-4-yl]-2,2'-bipyridine (abbreviation: PAPP2BPy), N,N'-diphenyl-N,N'-bis[4-(9-phenyl-9H-fluoren-9-yl)phenyl]pyrene-1,6-diamine (abbreviation: 1,6FLPAPrn), N,N'-bis(3-methylphenyl)-N,N'-bis[3-(9-phenyl-9H-fluoren-9-yl)phenyl]pyrene-1,6-diamine )phenyl]pyrene-1,6-diamine (abbreviation: 1,6mMemFLPAPrn), N,N'-bis[4-(9H-carbazol-9-yl)phenyl]-N,N'-diphenylstilbene-4,4'-diamine (abbreviation: YGA2S), 4-(9H-carbazol-9-yl)-4'-(10-phenyl-9-anthryl)triphenylamine (abbreviation: YGAPA), 4-(9H-carbazol-9-yl)-4'-(9,10-diphenyl-2-anthryl)triphenylamine (abbreviation: 2YGAPPA), N,9-diphenyl-N-[4-( 10-phenyl-9-anthryl)phenyl]-9H-carbazol-3-amine (abbreviation: PCAPA), perylene, 2,5,8,11-tetra-tert-butylperylene (abbreviation: TBP), 4-(10-phenyl-9-anthryl)-4'-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBAPA), N,N''-(2-tert-butylanthracene-9,10-diyldi-4,1-phenylene)bis(N,N',N'-triphenyl-1,4-phenylenediamine) (abbreviation: DPABPA), N,9 -diphenyl-N-[4-(9,10-diphenyl-2-anthryl)phenyl]-9H-carbazol-3-amine (abbreviation: 2PAPPA), N-[4-(9,10-diphenyl-2-anthryl)phenyl]-N,N',N'-triphenyl-1,4-phenylenediamine (abbreviation: 2DPAPPA), N,N,N',N',N'',N'',N''',N'''-octaphenyldibenzo[g,p]chrysene-2,7,10,15-tetraamine (abbreviation: DBC1), Coumarin 30, N-(9,10-diphenyl-2-anthryl)-N,9-Diphenyl-9H-carbazole-3-amine (abbreviation: 2PCAPA), N-[9,10-bis(biphenyl-2-yl)-2-anthryl]-N,9-diphenyl-9H-carbazole-3-amine (abbreviation: 2PCABPhA), N-(9,10-diphenyl-2-anthryl)-N,N',N'-triphenyl-1,4-phenylenediamine (abbreviation: 2DPAPA), N-[9,10-bis(biphenyl-2-yl)-2-anthryl]-N,N',N'-triphenyl-1,4-phenylenediamine (abbreviation: 2DPABPhA) , 9,10-bis(biphenyl-2-yl)-N-[4-(9H-carbazol-9-yl)phenyl]-N-phenylanthracen-2-amine (abbreviation: 2YGABPhA), N,N,9-triphenylanthracen-9-amine (abbreviation: DPhAPhA), Coumarin 545T, N,N'-diphenylquinacridone (abbreviation: DPQd), rubrene, 5,12-bis(biphenyl-4-yl)-6,11-diphenyltetracene (abbreviation: BPT), 2-(2-{2-[4-(dimethylamino)phenyl]ethenyl}-6-methyl-4H-pyra N,N,N',N'-tetrakis(4-methylphenyl)acenaphtho[1,2-a]fluoranthene-3,10-diamine (abbreviation: p-mPhTD), 2-{2-methyl-6-[2-(2,3,6,7-tetrahydro-1H,5H-benzo[ij]quinolizin-9-yl)ethenyl]-4H-pyran-4-ylidene}propanedinitrile (abbreviation: DCM1), 2-{2-methyl-6-[2-(2,3,6,7-tetrahydro-1H,5H-benzo[ij]quinolizin-9-yl)ethenyl]-4H-pyran-4-ylidene}propanedinitrile (abbreviation: DCM2), N,N,N',N'-tetrakis(4-methylphenyl)tetracene-5,11-diamine (abbreviation: p-mPhTD), 7,14-diphenyl-N,N,N',N'-tetrakis(4-methylphenyl)acenaphtho[1,2-a]fluoranthene-3,10-diamine (abbreviation: p-mPhTD), Name: p-mPhAFD), 2-{2-isopropyl-6-[2-(1,1,7,7-tetramethyl-2,3,6,7-tetrahydro-1H,5H-benzo[ij]quinolizin-9-yl)ethenyl]-4H-pyran-4-ylidene}propanedinitrile (abbreviation: DCJTI), 2-{2-tert-butyl-6-[2-(1,1,7,7-tetramethyl-2,3,6,7-tetrahydro-1H,5H-benzo[ij]quinolizin-9-yl)ethenyl]-4H-pyran-4-ylidene}propanedinitrile (abbreviation: DCJTB), 2-(2,6-bis{2-[4-(dimethylamino)phenyl]ethenyl}-4H-pyran-4-ylidene)propanedinitrile (abbreviation: BisDCM), 2-{2,6-bis[2-(8-methoxy-1,1,7,7-tetramethyl-2,3,6,7-tetrahydro-1H,5H-benzo[ij]quinolizin-9-yl)ethenyl]-4H-pyran-4-ylidene}propanedinitrile (abbreviation: BisDCJ™), N,N'-diphenyl-N,N'-(1,6-pyren-diyl)bis[(6-phenylbenzo[b]naphthyl)benzo[b]naphthyl] ... 6,7-b']bisbenzofuran-3,10-diamine (abbreviation: 3,10PCA2Nbf(IV)-02), and 3,10-bis[N-(dibenzofuran-3-yl)-N-phenylamino]naphtho[2,3-b;6,7-b']bisbenzofuran (abbreviation: 3,10FrA2Nbf(IV)-02). In particular, condensed aromatic diamine compounds, such as pyrene diamine compounds 1,6FLPAPrn, 1,6mMemFLPAPrn, and 1,6BnfAPrn-03, are preferred because they have high hole trapping properties and excellent luminous efficiency or reliability.

[0176] Furthermore, 5,9-diphenyl-5,9-diaza-13b-boranaphtho[3,2,1-de]anthracene (abbreviation: DABNA1), 9-(biphenyl-3-yl)-N,N,5,11-tetraphenyl-5H,9H-[1,4]benzazaborino[2,3,4-kl]phenazaborin-3-amine (abbreviation: DABNA2), 2,12-di(tert-butyl)-5,9-di(4-tert-butylphenyl)-N,N-diphenyl-5H,9H-[1,4]benzazaborino[2,3,4-kl]phenazaborin-7-amine (abbreviation: DABNA3), amine (abbreviation: DPhA-tBu4DABNA), 2,12-di(tert-butyl)-N,N,5,9-tetra(4-tert-butylphenyl)-5H,9H-[1,4]benzazaborino[2,3,4-kl]phenazaborin-7-amine (abbreviation: tBuDPhA-tBu4DABNA), 2,12-di(tert-butyl)-5,9-di(4-tert-butylphenyl)-7-methyl-5H,9H-[1,4]benzazaborino[2,3,4-kl]phenazaborin (abbreviation: Me-tBu4DABNA), N ７ , N ７ , N １３ , N １３ Condensed heteroaromatic compounds containing nitrogen and boron, such as 5,9,11,15-octaphenyl-5H,9H,11H,15H-[1,4]benzazaborino[2,3,4-kl][1,4]benzazaborino[4',3',2':4,5][1,4]benzazaborino[3,2-b]phenazaborine-7,13-diamine (abbreviation: v-DABNA), and 2-(4-tert-butylphenyl)benz[5,6]indolo[3,2,1-jk]benzo[b]carbazole (abbreviation: tBuPBibc), in particular compounds having a diazaboranaphthoanthracene skeleton, can be suitably used because they have a narrow emission spectrum and can emit blue light with good color purity.

[0177] In addition to these, 9,10,11-tris[3,6-bis(1,1-dimethylethyl)-9H-carbazolyl-9-yl]-2,5,15,18-tetrakis(1,1-dimethylethyl)indolo[3,2,1-de]indolo[3',2',1':8,1][1,4]benzazaborino[2,3,4-kl]phenazaborine (abbreviation: BBCz-G), 9,11-bis[3,6-bis(1,1-dimethylethyl)-9H-carbazolyl-9-yl]-2,5,15,18-tetrakis(1,1-dimethylethyl)indolo[3,2,1-de]indolo[3',2',1':8,1][1,4]benzazaborino[2,3,4-kl]phenazaborine (abbreviation: BBCz-Y) and the like can be preferably used.

[0178] When a phosphorescent substance is used as the light-emitting substance in the light-emitting layer 113, the phosphorescent substance is preferably a metal complex, particularly an iridium complex or a platinum complex, and examples thereof include the following materials.

[0179] Tris{2-[5-(2-methylphenyl)-4-(2,6-dimethylphenyl)-4H-1,2,4-triazol-3-yl-κN]phenyl-κC}iridium(III) (abbreviation: [Ir(mpptz-dmp) ３ ]), tris(5-methyl-3,4-diphenyl-4H-1,2,4-triazolato)iridium(III) (abbreviation: [Ir(Mptz) ３ ]), organometallic iridium complexes having a 4H-triazole skeleton such as tris[3-methyl-1-(2-methylphenyl)-5-phenyl-1H-1,2,4-triazolato]iridium(III) (abbreviation: [Ir(Mptz1-mp) ３ ]), tris(1-methyl-5-phenyl-3-propyl-1H-1,2,4-triazolato)iridium(III) (abbreviation: [Ir(Prptz1-Me) ３ organometallic iridium complexes having a 1H-triazole skeleton, such as fac-tris[1-(2,6-diisopropylphenyl)-2-phenyl-1H-imidazole]iridium(III) (abbreviation: [Ir(iPrpim) ３]), tris[3-(2,6-dimethylphenyl)-7-methylimidazo[1,2-f]phenanthridinato]iridium(III) (abbreviation: [Ir(dmpimpt-Me) ３ organometallic iridium complexes having an imidazole skeleton, such as tris(2-{1-[2,6-bis(1-methylethyl)phenyl]-1H-imidazol-2-yl-κN}-4-cyanophenyl-κC)iridium(III) (abbreviation: CNImIr), tris[(6-tert-butyl-3-phenyl-2H-imidazo[4,5-b]pyrazin-1-yl-κC)phenyl-κC]iridium(III) (abbreviation: [Ir(cb) ３ organometallic complexes having a benzimidazolidene skeleton, such as bis[2-(4',6'-difluorophenyl)pyridinato-N,C ２’ ]iridium(III) tetrakis(1-pyrazolyl)borate (abbreviation: FIr6), bis[2-(4',6'-difluorophenyl)pyridinato-N,C ２’ ]iridium(III) picolinate (abbreviation: FIrpic), bis{2-[3',5'-bis(trifluoromethyl)phenyl]pyridinato-N,C ２’} Iridium(III) picolinate (abbreviation: [Ir(CF ３ ppy) ２ (pic)]), bis[2-(4',6'-difluorophenyl)pyridinato-N,C ２’ Examples of suitable iridium complexes include organometallic iridium complexes having a phenylpyridine derivative having an electron-withdrawing group as a ligand, such as ]iridium(III) acetylacetonate (abbreviation: FIracac), and platinum complexes such as (2-{3-[3-(3,5-di-tert-butylphenyl)benzimidazol-1-yl-2-ylidene-κC2]phenoxy-κC2}-9-(4-tert-butyl-2-pyridinyl-κN)carbazole-2,1-diyl-κC1)platinum(II) (abbreviation: PtON-TBBI). These compounds exhibit blue phosphorescence and have an emission peak in the wavelength range of 450 nm to 520 nm. Compounds in which some of the hydrogen atoms in these compounds are replaced with deuterium atoms can also be used.

[0180] Also, tris(4-methyl-6-phenylpyrimidinato)iridium(III) (abbreviation: [Ir(mppm) ３ ]), tris(4-t-butyl-6-phenylpyrimidinato)iridium(III) (abbreviation: [Ir(tBuppm) ３ ]), (acetylacetonato)bis(6-methyl-4-phenylpyrimidinato)iridium(III) (abbreviation: [Ir(mppm) ２ (acac)]), (acetylacetonato)bis(6-tert-butyl-4-phenylpyrimidinato)iridium(III) (abbreviation: [Ir(tBuppm) ２ (acac)]), (acetylacetonato)bis[6-(2-norbornyl)-4-phenylpyrimidinato]iridium(III) (abbreviation: [Ir(nbppm) ２ (acac)]), (acetylacetonato)bis[5-methyl-6-(2-methylphenyl)-4-phenylpyrimidinato]iridium(III) (abbreviation: [Ir(mpmppm) ２ (acac)]), (acetylacetonato)bis(4,6-diphenylpyrimidinato)iridium(III) (abbreviation: [Ir(dppm) ２ organometallic iridium complexes having a pyrimidine skeleton, such as (acetylacetonato)bis(3,5-dimethyl-2-phenylpyrazinato)iridium(III) (abbreviation: [Ir(mppr-Me) ２ (acac)]), (acetylacetonato)bis(5-isopropyl-3-methyl-2-phenylpyrazinato)iridium(III) (abbreviation: [Ir(mppr-iPr) ２ organometallic iridium complexes having a pyrazine skeleton, such as tris(2-phenylpyridinato-N,C(acac)]); ２’ ) Iridium(III) (abbreviation: [Ir(ppy) ３ ]), bis(2-phenylpyridinato-N,C ２’ ) Iridium(III) acetylacetonate (abbreviation: [Ir(ppy) ２ (acac)]), bis(benzo[h]quinolinato)iridium(III) acetylacetonate (abbreviation: [Ir(bzq) ２(acac)]), tris(benzo[h]quinolinato)iridium(III) (abbreviation: [Ir(bzq) ３ ]), tris(2-phenylquinolinato-N,C ２’ ) Iridium(III) (abbreviation: [Ir(pq) ３ ]), bis(2-phenylquinolinato-N,C ２’ ) iridium(III) acetylacetonate (abbreviation: [Ir(pq) ２ (acac)]), [2-d3-methyl-8-(2-pyridinyl-κN)benzofuro[2,3-b]pyridine-κC]bis[2-(5-d ３ [5-methyl-2-pyridinyl-κN)phenyl-κC]iridium(III) (abbreviation: Ir(5mppy-d ３ ) ２ (mbfpypy-d ３ )), {2-(methyl-d ３ )-8-[4-(1-methylethyl-1-d)-2-pyridinyl-κN]benzofuro[2,3-b]pyridin-7-yl-κC}bis{5-(methyl-d ３ )-2-[5-(methyl-d ３ )-2-pyridinyl-κN]phenyl-κC}iridium(III) (abbreviation: Ir(5mtpy-d6) ２ (mbfpypy-iPr-d ４ )), [2-d ３ -methyl-(2-pyridinyl-κN)benzofuro[2,3-b]pyridine-κC]bis[2-(2-pyridinyl-κN)phenyl-κC]iridium(III) (abbreviation: Ir(ppy) ２ (mbfpypy-d ３ )), [2-(4-methyl-5-phenyl-2-pyridinyl-κN)phenyl-κC]bis[2-(2-pyridinyl-κN)phenyl-κC]iridium(III) (abbreviation: Ir(ppy) ２ (mdppy)), [2-(4-d ３ -methyl-5-phenyl-2-pyridinyl-κN)phenyl-κC]bis[2-(5-d ３ [Ir(5mppy-d-methyl-2-pyridinyl-κN)phenyl-κC]iridium(III) (abbreviation: [Ir(5mppy-d-methyl-2-pyridinyl-κN)phenyl-κC]iridium(III) ３ )2(mdppy-d３ ) )]), [2-methyl-(2-pyridinyl-κN)benzofuro[2,3-b]pyridine-κC]bis[2-(2-pyridinyl-κN)phenyl-κC]iridium(III) (abbreviation: [Ir(ppy) ２ (mbfpypy)]), [2-(4-methyl-5-phenyl-2-pyridinyl-κN)phenyl-κC]bis[2-(2-pyridinyl-κN)phenyl-κC]iridium (abbreviation: [Ir(ppy) ２ (mdppy)]), tris{2-[5-(methyl-d3)-4-phenyl-2-pyridinyl-κN]phenyl-κC}iridium(III) (abbreviation: Ir(5m4dppy-d ３ ) ３ In addition to organometallic iridium complexes having a pyridine skeleton such as (2-{1-(5-tert-butylbiphenyl-2-yl)-4-[3-tert-butyl-5-(4-phenyl-2-pyridinyl-κN)phenyl-κC6]-2-benzimidazolyl-κN3}-4,6-di-tert-butylphenolato-κO)platinum(II) (abbreviation: Pt(tBudppymmtBubiz-tBubp)), [2-(4-(3,5-di-te organometallic platinum complexes such as [Tb(acac)]-4-(4-(4-(5'-tert-butylphenyl)-6-{3-[4-(5'-tert-butyl[1,1':3',1''-terphenyl]-2'-yl)-2-pyridinyl-κN]phenyl-κC2}-2-pyridinyl-κN)phenolato-κO]platinum(II) (abbreviation: Pt(4tButppppypyp-mmtBup)); tris(acetylacetonato)(monophenanthroline)terbium(III) (abbreviation: [Tb(acac)] ３ Examples of suitable iridium complexes include rare earth metal complexes such as iridium fluoride (Phen). These compounds exhibit phosphorescence with a predominantly green hue, and have an emission peak in the wavelength range of 500 nm to 600 nm. Organometallic iridium complexes having a pyrimidine skeleton are particularly preferred because of their outstanding reliability and luminous efficiency. Compounds in which some of the hydrogen atoms in these compounds are replaced with deuterium atoms can also be used.

[0181] Also, (diisobutyrylmethanato)bis[4,6-bis(3-methylphenyl)pyrimidinato]iridium(III) (abbreviation: [Ir(5mdppm) ２ (dibm)]), bis[4,6-bis(3-methylphenyl)pyrimidinato](dipivaloylmethanato)iridium(III) (abbreviation: [Ir(5mdppm) ２ (dpm)]), bis[4,6-di(naphthalen-1-yl)pyrimidinato](dipivaloylmethanato)iridium(III) (abbreviation: [Ir(dpm) ２ organometallic iridium complexes having a pyrimidine skeleton, such as (acetylacetonato)bis(2,3,5-triphenylpyrazinato)iridium(III) (abbreviation: [Ir(tppr) ２ (acac)]), bis(2,3,5-triphenylpyrazinato)(dipivaloylmethanato)iridium(III) (abbreviation: [Ir(tppr) ２ (dpm)]), (acetylacetonato)bis[2,3-bis(4-fluorophenyl)quinoxalinato]iridium(III) (abbreviation: [Ir(Fdpq) ２ organometallic iridium complexes having a pyrazine skeleton, such as tris(1-phenylisoquinolinato-N,C(acac)]); ２’ ) Iridium(III) (abbreviation: [Ir(piq) ３ ]), bis(1-phenylisoquinolinato-N,C ２’ ) iridium(III) acetylacetonate (abbreviation: [Ir(piq) ２(acac)]), (3,7-diethyl-4,6-nonanedionato-κO4,κO6)bis[2,4-dimethyl-6-[7-(1-methylethyl)-1-isoquinolinyl-κN]phenyl-κC]iridium(III), (3,7-diethyl-4,6-nonanedionato-κO4,κO6)bis[2,4-dimethyl-6-[5-(1-methylethyl)-2-quinolinyl-κN]phenyl-κC]iridium(III). In addition to organometallic iridium complexes having a pyridine skeleton such as [ru-κC]iridium(III), platinum complexes such as 2,3,7,8,12,13,17,18-octaethyl-21H,23H-porphyrinplatinum(II) (abbreviation: PtOEP), tris(1,3-diphenyl-1,3-propanedionato)(monophenanthroline)europium(III) (abbreviation: [Eu(DBM) ３ (Phen)]), tris[1-(2-thenoyl)-3,3,3-trifluoroacetonato](monophenanthroline)europium(III) (abbreviation: [Eu(TTA) ３ Examples of suitable compounds include rare earth metal complexes such as iridium fluoride (Phen). These compounds exhibit red phosphorescence and have an emission peak in the wavelength range of 600 nm to 700 nm. Organometallic iridium complexes having a pyrazine skeleton can emit red light with good chromaticity. Compounds in which some of the hydrogen atoms in these compounds are replaced with deuterium atoms can also be used.

[0182] In one embodiment of the present invention, the use of a deuterated compound as the luminescent center substance improves luminous efficiency, and therefore the luminescent center substance is preferably a deuterated material.

[0183] In addition to the phosphorescent compounds described above, known phosphorescent compounds may be selected and used.

[0184] Examples of TADF materials that can be used include fullerene and its derivatives, acridine and its derivatives, and eosin derivatives. Other examples include metal-containing porphyrins containing magnesium (Mg), zinc (Zn), cadmium (Cd), tin (Sn), platinum (Pt), indium (In), or palladium (Pd). Examples of metal-containing porphyrins include protoporphyrin-tin fluoride complexes (SnF) represented by the following structural formula: ２ (Proto IX)), mesoporphyrin-tin fluoride complex (SnF ２ (Meso IX)), hematoporphyrin-tin fluoride complex (SnF ２ (Hemato IX)), coproporphyrin tetramethyl ester-tin fluoride complex (SnF ２ (Copro III-4Me)), octaethylporphyrin-tin fluoride complex (SnF ２ (OEP)), etioporphyrin-tin fluoride complex (SnF ２ (Etio I)), octaethylporphyrin-platinum chloride complex (PtCl ２ OEP) and the like.

[0185]

[0186] Further, 2-(biphenyl-4-yl)-4,6-bis(12-phenylindolo[2,3-a]carbazol-11-yl)-1,3,5-triazine (abbreviation: PIC-TRZ), 9-(4,6-diphenyl-1,3,5-triazin-2-yl)-9′-phenyl-9H,9′H-3,3′-bicarbazole (abbreviation: PCCzTzn), 2-{4-[3-(N-phenyl-9H-carbazol-3-yl)-9H-carbazol-9-yl]phenyl}-4,6-diphenyl-1,3,5-triazine (abbreviation: PCCzPTzn), 2-[4-(10H-phenoxazin-10-yl)phenyl]-4,6-diphenyl-1,3,5-triazine (abbreviation: PCCzPTzn), and Heterocyclic compounds having one or both of a π-electron rich heteroaromatic ring and a π-electron deficient heteroaromatic ring, such as 3-[4-(5-phenyl-5,10-dihydrophenazin-10-yl)phenyl]-4,5-diphenyl-1,2,4-triazole (abbreviation: PPZ-3TPT), 3-(9,9-dimethyl-9H-acridin-10-yl)-9H-xanthen-9-one (abbreviation: ACRXTN), bis[4-(9,9-dimethyl-9,10-dihydroacridine)phenyl]sulfone (abbreviation: DMAC-DPS), and 10-phenyl-10H,10′H-spiro[acridine-9,9′-anthracene]-10′-one (abbreviation: ACRSA), can also be used. The heterocyclic compound has a π-electron-rich heteroaromatic ring and a π-electron-deficient heteroaromatic ring, and therefore has high electron transport and hole transport properties, and is therefore preferred. Among the skeletons having a π-electron-deficient heteroaromatic ring, pyridine skeleton, diazine skeleton (pyrimidine skeleton, pyrazine skeleton, pyridazine skeleton), and triazine skeleton are preferred because they are stable and reliable. In particular, benzofuropyrimidine skeleton, benzothienopyrimidine skeleton, benzofuropyrazine skeleton, and benzothienopyrazine skeleton are preferred because they have high acceptor properties and good reliability. Furthermore, among the skeletons having a π-electron-rich heteroaromatic ring, acridine skeleton, phenoxazine skeleton, phenothiazine skeleton, furan skeleton, thiophene skeleton, and pyrrole skeleton are preferred because they are stable and reliable.The furan skeleton is preferably a dibenzofuran skeleton, and the thiophene skeleton is preferably a dibenzothiophene skeleton. The pyrrole skeleton is particularly preferably an indole skeleton, a carbazole skeleton, an indolocarbazole skeleton, a bicarbazole skeleton, or a 3-(9-phenyl-9H-carbazol-3-yl)-9H-carbazole skeleton. A substance in which a π-electron-rich heteroaromatic ring and a π-electron-deficient heteroaromatic ring are directly bonded is particularly preferred because the electron-donating property of the π-electron-rich heteroaromatic ring and the electron-accepting property of the π-electron-deficient heteroaromatic ring are both enhanced, reducing the energy difference between the S1 level and the T1 level, thereby enabling efficient thermally activated delayed fluorescence. Instead of the π-electron-deficient heteroaromatic ring, an aromatic ring bonded to an electron-withdrawing group such as a cyano group may be used. The π-electron-rich skeleton may be, for example, an aromatic amine skeleton or a phenazine skeleton. Examples of usable π-electron-deficient skeletons include a xanthene skeleton, a thioxanthene dioxide skeleton, an oxadiazole skeleton, a triazole skeleton, an imidazole skeleton, an anthraquinone skeleton, a boron-containing skeleton such as phenylborane or boranthrene, an aromatic ring having a nitrile group or a cyano group such as benzonitrile or cyanobenzene, a heteroaromatic ring, a carbonyl skeleton such as benzophenone, a phosphine oxide skeleton, a sulfone skeleton, etc. In this way, a π-electron-deficient skeleton and a π-electron-rich skeleton can be used in place of at least one of a π-electron-deficient heteroaromatic ring and a π-electron-rich heteroaromatic ring.

[0187]

[0188] Alternatively, a TADF material in which the singlet excited state and the triplet excited state are in thermal equilibrium may be used. Such a TADF material has a short emission lifetime (excitation lifetime), which can suppress a decrease in efficiency in the high-brightness region of a light-emitting device. Specific examples include materials with the molecular structure shown below.

[0189]

[0190] The TADF material is a material that has a small difference between the S1 level and the T1 level and has the function of converting triplet excitation energy to singlet excitation energy by reverse intersystem crossing. Therefore, triplet excitation energy can be upconverted to singlet excitation energy (reverse intersystem crossing) with a small amount of thermal energy, and a singlet excited state can be efficiently generated. Furthermore, triplet excitation energy can be converted into luminescence.

[0191] Furthermore, an exciplex (also called an exciplex) that forms an excited state with two types of substances has an extremely small difference between the S1 level and the T1 level, and functions as a TADF material that can convert triplet excitation energy into singlet excitation energy.

[0192] The T1 level can be determined by using a phosphorescence spectrum observed at low temperatures (e.g., 77 K to 10 K). When a tangent line is drawn at the base of the fluorescence spectrum on the short wavelength side of the TADF material, and the energy of the wavelength of the extrapolated line is defined as the S1 level, and when a tangent line is drawn at the base of the phosphorescence spectrum on the short wavelength side of the TADF material, and the energy of the wavelength of the extrapolated line is defined as the T1 level, the difference between S1 and T1 is preferably 0.3 eV or less, and more preferably 0.2 eV or less.

[0193] When a TADF material is used as a light-emitting material, the S1 level of the host material is preferably higher than the S1 level of the TADF material, and the T1 level of the host material is preferably higher than the T1 level of the TADF material.

[0194] As a host material for the light-emitting layer 113, various carrier transporting materials such as a substance having an electron transporting property and / or a substance having a hole transporting property, or the above-mentioned TADF material can be used.

[0195] An organic compound having an amine skeleton or a π-electron-rich heteroaromatic ring skeleton is preferable as a substance having a hole-transporting property that can be used as a host material for the light-emitting layer 113. The π-electron-rich heteroaromatic ring is preferably a fused aromatic ring containing at least one of an acridine skeleton, a phenoxazine skeleton, a phenothiazine skeleton, a furan skeleton, a thiophene skeleton, and a pyrrole skeleton in the ring, and specifically, a carbazole ring, a dibenzothiophene ring, or a ring in which an aromatic ring or a heteroaromatic ring is further fused to one of these rings is preferable.

[0196] The hole-transporting substance preferably has at least one of a carbazole skeleton, a dibenzofuran skeleton, a dibenzothiophene skeleton, and an anthracene skeleton. In particular, the hole-transporting substance may be an aromatic amine having a substituent containing a dibenzofuran ring or a dibenzothiophene ring, an aromatic monoamine having a naphthalene ring, or an aromatic monoamine in which a 9-fluorenyl group is bonded to the nitrogen of the amine via an arylene group. It is preferable that the hole-transporting substance be an organic compound having an N,N-bis(4-biphenyl)amino group, since this allows the fabrication of a light-emitting device with a long lifetime.

[0197] As such an organic compound, for example, the following organic compounds are preferable: 4,4'-bis[N-(1-naphthyl)-N-phenylamino]biphenyl (abbreviation: NPB), N,N'-diphenyl-N,N'-bis(3-methylphenyl)-4,4'-diaminobiphenyl (abbreviation: TPD), N,N'-bis(9,9'-spirobi[9H-fluoren]-2-yl)-N,N'-diphenyl-4,4'-diaminobiphenyl (abbreviation: BSPB), 4-phenyl-4'-(9-phenylfluoren-9-yl)triphenylamine (abbreviation: BPAFLP), 4-phenyl-3 ... )triphenylamine (abbreviation: mBPAFLP), 4-phenyl-4'-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBA1BP), 4,4'-diphenyl-4''-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBBi1BP), 4-(1-naphthyl)-4'-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBANB), 4,4'-di(1-naphthyl)-4''-(9-phenyl-9H-carbazol-3-yl)triphenylamine compounds having an aromatic amine skeleton such as 9,9-dimethyl-N-phenyl-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]fluoren-2-amine (abbreviation: PCBA), N-phenyl-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-9,9′-spirobi[9H-fluorene]-2-amine (abbreviation: PCBASF); 1,3-bis(N-carbazolyl)benzene (abbreviation: mCP); 4,4′-di(N-carbazolyl)biphenyl (abbreviation: C BP), 3,6-bis(3,5-diphenylphenyl)-9-phenylcarbazole (abbreviation: CzTP), 9,9'-diphenyl-9H,9'H-3,3'-bicarbazole (abbreviation: PCCP), 3,9-bis(9-phenyl-9H-carbazol-3-yl)-9H-carbazole (abbreviation: PCCzPC), 9-(biphenyl-4-yl)-9'-phenyl-3,3'-bi-9H-carbazole (abbreviation: PCCzBP), 9,9'-bis(biphenyl-4-yl)-3,3'-bi-9H-carbazole (abbreviation: BisBPCz), 9,9'-Bis(biphenyl-3-yl)-3,3'-bi-9H-carbazole (abbreviation: BismBPCz), 9-(biphenyl-3-yl)-9'-(biphenyl-4-yl)-9H,9'H-3,3'-bicarbazole (abbreviation: mBPCCBP), 9-(2-naphthyl)-9'-phenyl-3,3'-bi-9H-carbazole (abbreviation: βNCCP), 9-(3-biphenyl)-9'-(2-naphthyl)-3,3'-bi-9H-carbazole (abbreviation: βNCCmBP), 9-(4-biphenyl)-9'-(2-naphthyl)-3, 3'-Bi-9H-carbazole (abbreviation: βNCCBP), 9,9'-di-2-naphthyl-3,3'-9H,9'H-bicarbazole (abbreviation: BisβNCz), 9-(2-naphthyl)-9'-[1,1':4',1"-terphenyl]-3-yl-3,3'-9H,9'H-bicarbazole, 9-(2-naphthyl)-9'-[1,1':3',1"-terphenyl]-3-yl-3,3'-9H,9'H-bicarbazole, 9-(2-naphthyl)-9'-[1,1':3',1"-terphenyl]-5'-yl-3,3'-9H ,9'H-bicarbazole, 9-(2-naphthyl)-9'-[1,1':4',1"-terphenyl]-4-yl-3,3'-9H,9'H-bicarbazole, 9-(2-naphthyl)-9'-[1,1':3',1"-terphenyl]-4-yl-3,3'-9H,9'H-bicarbazole, 9-(2-naphthyl)-9'-(triphenylen-2-yl)-3,3'-9H,9'H-bicarbazole, 9-phenyl-9'-(triphenylen-2-yl)-3,3'-9H,9'H-bicarbazole (abbreviation: PCCzTp), 9,9'-bis(triphenylen-2-yl)-3,3'-9H,9'H-bicarbazole, 9-(4-biphenyl)-9'-(triphenylen-2-yl)-3,3'-9H,9'H-bicarbazole, 9-(triphenylen-2-yl)-9'-[1,1':3',1"-terphenyl]-4-yl-3,3'-9H,9'H-bicarbazole, N,N-bis(9,9-dimethyl-9H-fluoren-2-yl)-9,9'-spirobi-9H-fluoren-1-amine, 9-[3-(triphenylsilyl)phenyl]-3,Compounds having a carbazole skeleton such as 9'-bi-9H-carbazole (abbreviation: PSiCzCz) and 9'-[3-(triphenylsilyl)phenyl]-9'H-9,3':6',9''-tercarbazole (abbreviation: PSiCzGI), 4,4',4''-(benzene-1,3,5-triyl)tri(dibenzothiophene) (abbreviation: DBT3P-II), 2,8-diphenyl-4-[4-(9-phenyl-9H-fluoren-9-yl)phenyl]dibenzothiophene (abbreviation: DBTFLP-I), Examples of suitable materials include compounds having a thiophene skeleton, such as 4-[4-(9-phenyl-9H-fluoren-9-yl)phenyl]-6-phenyldibenzothiophene (abbreviation: DBTFLP-IV), and compounds having a furan skeleton, such as 4,4',4''-(benzene-1,3,5-triyl)tri(dibenzofuran) (abbreviation: DBF3P-II) and 4-{3-[3-(9-phenyl-9H-fluoren-9-yl)phenyl]phenyl}dibenzofuran (abbreviation: mmDBFFLBi-II). Among the above, compounds having an aromatic amine skeleton or a carbazole skeleton are preferred because they have good reliability, high hole transport properties, and contribute to reducing driving voltage. The organic compounds listed as examples of materials having hole transport properties for the hole transport layer can also be used.

[0198] The substance having an electron transporting property that can be used as a host material of the light-emitting layer 113 is a substance having an electron mobility of 1×10 or less at a square root of an electric field strength [V / cm] of 600. −７ cm ２ / Vs or more, preferably 1×10 −６ cm ２ A substance having an electron mobility of 1 / Vs or more is preferred. Note that other substances can be used as long as they have a higher electron transporting property than a hole transporting property.

[0199] An example of a substance having electron transport properties is bis(10-hydroxybenzo[h]quinolinato)beryllium(II) (abbreviation: BeBq ２Preferred are metal complexes such as bis(2-methyl-8-quinolinolato)(4-phenylphenolato)aluminum(III) (abbreviation: BAlq), bis(8-quinolinolato)zinc(II) (abbreviation: Znq), bis[2-(2-benzoxazolyl)phenolato]zinc(II) (abbreviation: ZnPBO), and bis[2-(2-benzothiazolyl)phenolato]zinc(II) (abbreviation: ZnBTZ), as well as organic compounds having a π-electron-deficient heteroaromatic ring. Examples of organic compounds having a π-electron-deficient heteroaromatic ring skeleton include organic compounds having a heteroaromatic ring with an azole skeleton, organic compounds having a heteroaromatic ring with a pyridine skeleton, organic compounds having a heteroaromatic ring with a diazine skeleton, and organic compounds having a heteroaromatic ring with a triazine skeleton.

[0200] Among these, organic compounds containing a heteroaromatic ring having a diazine skeleton (pyrimidine skeleton, pyrazine skeleton, pyridazine skeleton), organic compounds containing a heteroaromatic ring having a pyridine skeleton, and organic compounds containing a heteroaromatic ring having a triazine skeleton are preferred because of their high reliability. In particular, organic compounds containing a heteroaromatic ring having a diazine (pyrimidine or pyrazine) skeleton and organic compounds containing a heteroaromatic ring having a triazine skeleton have high electron transport properties and contribute to reducing driving voltage. In addition, benzofuropyrimidine skeletons, benzothienopyrimidine skeletons, benzofuropyrazine skeletons, and benzothienopyrazine skeletons are preferred because of their high acceptor properties and high reliability.

[0201] As the organic compound having a π-electron-deficient heteroaromatic ring skeleton, for example, the following organic compounds are preferred: 2-(4-biphenylyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole (abbreviation: PBD), 3-(4-biphenylyl)-4-phenyl-5-(4-tert-butylphenyl)-1,2,4-triazole (abbreviation: TAZ), 1,3-bis[5-(p-tert-butylphenyl)-1,3,4-oxadiazol-2-yl]benzene (abbreviation: OXD-7), 9-[4-(5-phenyl-1,3,4-oxadiazol-2-yl)phenyl]-9H-carbazole (abbreviation: organic compounds having an azole skeleton, such as 2,2',2''-(1,3,5-benzenetriyl)tris(1-phenyl-1H-benzimidazole) (abbreviation: TPBI), 2-[3-(dibenzothiophen-4-yl)phenyl]-1-phenyl-1H-benzimidazole (abbreviation: mDBTBIm-II), and 4,4'-bis(5-methylbenzoxazol-2-yl)stilbene (abbreviation: BzOs); 3,5-bis[3-(9H-carbazol-9-yl)phenyl]pyridine (abbreviation: 35DCzPPy), 1,3,5-tri[3-(3-pyridyl)phenyl]benzene (abbreviation: TmPyPB), bathophenanthroline (abbreviation: Bphen), bathocuproine (abbreviation: BCP), 2,9-di(naphthalen-2-yl)-4,7-diphenyl-1,10-phenanthroline (abbreviation: NBphen), 2,2'-(1,3-phenylene)bis(9-phenyl-1,10-phenanthroline) (abbreviation: mPPhen2P), 2-[3-(2-triphenylenyl)phenyl]-1,10-phenane organic compounds containing a heteroaromatic ring having a pyridine skeleton, such as 2-[3-(dibenzothiophen-4-yl)phenyl]dibenzo[f,h]quinoxaline (abbreviation: 2mDBTPDBq-II), 2-[3'-(dibenzothiophen-4-yl)biphenyl-3-yl]dibenzo[f,h]quinoxaline (abbreviation: 2mDBTBPDBq-II), 2-[3'-(9H-carbazol-9-yl)biphenyl-3-yl]dibenzo[f,h]quinoxaline (abbreviation: 2mCzBPDBq), 2-[4'-(9-phenyl-9H-carbazol-3-yl)-3,1'-biphenyl-1-yl]dibenzo[f,h]quinoxaline (abbreviation: 2mpPCBPDBq), 2-[4-(3,6-diphenyl 1-[3-(dibenzothiophen-4-yl)phenyl]dibenzo[f,h]quinoxaline (abbreviation: 2CzPDBq-III), 7-[3-(dibenzothiophen-4-yl)phenyl]dibenzo[f,h]quinoxaline (abbreviation: 7mDBTPDBq-II), and 6-[3-(dibenzothiophen-4-yl)phenyl]dibenzo[f,h]quinoxaline (abbreviation: 6mDBTPDBq-II), 9-[3'-(dibenzothiophen-4-yl)biphenyl-3-yl]naphtho[1',2':4,5]furo[2,3-b]pyrazine (abbreviation: 9mDBtBPNf pr), 9-[3'-(dibenzothiophen-4-yl)biphenyl-4-yl]naphtho[1',2':4,5]furo[2,3-b]pyrazine (abbreviation: 9pmDBtBPNfpr), 4,6-bis[3-(phenanthrene-9-yl)phenyl]pyrimidine (abbreviation: 4,6mPnP2Pm), 4,6-bis[3-(dibenzothiophen-4-yl)phenyl]pyrimidine (abbreviation: 4,6mDBTP2Pm-II), 4,6-bis[3-(9H-carbazol-9-yl)phenyl]pyrimidine (abbreviation: 4,6mCzP2Pm), 9,9'-[pyrimidinyl 4,6-diphenyl-4,6-diylbis(biphenyl-3,3′-diyl)]bis(9H-carbazole) (abbreviation: 4,6mCzBP2Pm), 8-(biphenyl-4-yl)-4-[3-(dibenzothiophen-4-yl)phenyl]-[1]benzofuro[3,2-d]pyrimidine (abbreviation: 8BP-4mDBtPBfpm), 3,8-bis[3-(dibenzothiophen-4-yl)phenyl]benzofuro[2,3-b]pyrazine (abbreviation: 3,8mDBtP2Bfpr), 4,8-bis[3-(dibenzothiophen-4-yl)phenyl]-[1]benzofuro[3,2-d]pyrimidine (abbreviation: 4,8mDBtP2Bfpm), 8-[3'-(dibenzothiophen-4-yl)biphenyl-3-yl]naphtho[1',2':4,5]furo[3,2-d]pyrimidine (abbreviation: 8mDBtBPNfpm)), 8-([2,2'-binaphthalen]-6-yl)-4-[3-(dibenzothiophen-4-yl)phenyl]-[1]benzofuro[3,2-d]pyrimidine (abbreviation: 8(βN2)-4mDBtPBfpm), 2,2'-(pyridine-2,6-diyl)bis(4-phenylbenzo[h]quinazoline) (abbreviation: 2,6 (P-Bqn)2Py), 2,2'-(pyridine-2,6-diyl)bis{4-[4-(2-naphthyl)phenyl]-6-phenylpyrimidine} (abbreviation: 2,6(NP-PPm)2Py), 6-(biphenyl-3-yl)-4-[3,5-bis(9H-carbazol-9-yl)phenyl]-2-phenylpyrimidine (abbreviation: 6mBP-4Cz2PPm), 2,6-bis(4-naphthalen-1-ylphenyl)-4-[4-(3-pyridyl)phenyl]pyrimidine (abbreviation: 2,4NP-6PyPPm), 4-[3,5-bis(9H-carbazole-9-yl)phenyl]pyrimidine phenyl)phenyl]-2-phenyl-6-(biphenyl-4-yl)pyrimidine (abbreviation: 6BP-4Cz2PPm), 7-[4-(9-phenyl-9H-carbazol-2-yl)quinazolin-2-yl]-7H-dibenzo[c,g]carbazole (abbreviation: PC-cgDBCzQz), 8-(p-terphenyl-3-yl)-4-[3-(dibenzothiophen-4-yl)phenyl]-[1]benzofuro[3,2-d]pyrimidine (abbreviation: 8mpTP-4mDBtPBfpm), 11-[3'-(dibenzothiophen-4-yl)biphenyl-3-yl] organic compounds having a diazine skeleton such as phenanthro[9',10':4,5]furo[2,3-b]pyrazine (abbreviation: 11mDBtBPPnfpr), 2-{3-[3-(N-phenyl-9H-carbazol-3-yl)-9H-carbazol-9-yl]phenyl}dibenzo[f,h]quinoxaline (abbreviation: 2mPCCzPDBq), 2-(biphenyl-4-yl)-4-phenyl-6-(9,9'-spirobi[9H-fluoren]-2-yl)-1,3,5-triazine (abbreviation: BP-SFTzn), 2-{3-[3-(benzo[b]naphtho[1,2-{3-[3-(benzo[b]naphtho[1,2-d]furan-6-yl)phenyl]phenyl}-4,6-diphenyl-1,3,5-triazine (abbreviation: mBnfBPTzn), 2-{3-[3-(benzo[b]naphtho[1,2-d]furan-6-yl)phenyl]phenyl}-4,6-diphenyl-1,3,5-triazine (abbreviation: mBnfBPTzn-02), 2-{4-[3-(N-phenyl-9H-carbazol-3-yl)-9H-carbazol-9-yl]phenyl}-4,6-diphenyl-1,3,5-triazine (abbreviation: PCCzPTzn), 9-[3-(4,6-diphenyl mPCCzPTzn-02), 2-[3'-(9,9-dimethyl-9H-fluoren-2-yl)biphenyl-3-yl]-4,6-diphenyl-1,3,5-triazine (abbreviation: mFBPTzn), 5-[3-(4,6-diphenyl-1,3,5-triazin-2-yl)phenyl]-7,7-dimethyl-5H,7H-indeno[2,1-b]carbazole (abbreviation: mINc(II)PTzn), 2-{3-[3- (dibenzothiophen-4-yl)phenyl]phenyl}-4,6-diphenyl-1,3,5-triazine (abbreviation: mDBtBPTzn), 2,4,6-tris[3'-(pyridin-3-yl)biphenyl-3-yl]-1,3,5-triazine (abbreviation: TmPPPyTz), 2-[3-(2,6-dimethyl-3-pyridinyl)-5-(9-phenanthryl)phenyl]-4,6-diphenyl-1,3,5-triazine (abbreviation: mPn-mDMePyPTzn), 11-[4-(biphenyl-4-yl)-6-phenyl-1,3,5-triazine [3'-(triphenylen-2-yl)biphenyl-3-yl]-4,6-diphenyl-1,3,5-triazine (abbreviation: mTpBPTzn), 3-[9-(4,6-diphenyl-1,3,5-triazin-2-yl)-2-dibenzofuranyl]-9-phenyl-9H-carbazole (abbreviation: PCDBfTzn), 2-(biphenyl-3-yl)-4-phenyl-6-[8-([1,1':4',1′-terphenyl]-4-yl)-1-dibenzofuranyl]-1,3,5-triazine (abbreviation: mBP-TPDBfTzn), 2-[4-(2-naphthyl)phenyl]-4-phenyl-6-spiro[9H-fluorene-9,9′-[9H]xanthene]-4-yl-1,3,5-triazine (abbreviation: βNP-SFx(4)Tzn), 9,9′-{6-[3-(triphenylsilyl)phenyl]-1,3,5-triazine azine-2,4-diyl}bis(9H-carbazole) (abbreviation: SiTrzCz2), 2-phenyl-4,6-bis[3-(triphenylsilyl)phenyl]-1,3,5-triazine (abbreviation: mSiTrz), 11-[4-(biphenyl-4-yl)-6-phenyl-1,3,5-triazin-2-yl]-11,12-dihydro-12-(biphenyl-3-yl)indolo[2,3-a]carbazole (abbreviation: BP -mBPIcz(II)Tzn), 3-{3-[9-(4,6-diphenyl-1,3,5-triazin-2-yl)-2-dibenzofuranyl]phenyl}-9-phenyl-9H-carbazole (abbreviation: mPCPDBfTzn), 9,9'-[6-(biphenyl-4-yl)-2-phenyl-1,3,5-triazine-4,3''-diyl]bis(9H-carbazole) (abbreviation: Cz-pmCzBPTzn), 3-phenyl Examples of suitable organic compounds include heteroaromatic rings with a triazine skeleton, such as 9-[4-phenyl-6-(9-phenyl-3-dibenzofuranyl)-1,3,5-triazin-2-yl]-9H-carbazole (abbreviation: PDBf-PCzTzn) and 9-[4-(4,6-diphenyl-1,3,5-triazin-2-yl)-2-dibenzothienyl]-2-phenyl-9H-carbazole (abbreviation: PCzDBtTzn). Organic compounds with heteroaromatic rings with a diazine skeleton, organic compounds with heteroaromatic rings with a pyridine skeleton, and organic compounds with heteroaromatic rings with a triazine skeleton are preferred due to their high reliability. In particular, organic compounds with heteroaromatic rings with a diazine (pyrimidine or pyrazine) skeleton and organic compounds with heteroaromatic rings with a triazine skeleton have high electron transport properties and contribute to reduced driving voltage.

[0202] The TADF materials that can be used as the host material can be the same as those listed above. When a TADF material is used as a host material, triplet excitation energy generated in the TADF material is converted into singlet excitation energy by reverse intersystem crossing, and the energy is further transferred to a light-emitting substance, thereby improving the luminous efficiency of the light-emitting device. In this case, the TADF material functions as an energy donor, and the light-emitting substance functions as an energy acceptor.

[0203] This is effective when the luminescent material is a fluorescent luminescent material. １ The level is the S of the fluorescent material. １ It is preferable that the T １ The level is the S of the fluorescent material. １ Therefore, the T １ The level is the T １ It is preferable that the level is higher.

[0204] It is also preferable to use a TADF material that emits light that overlaps with the wavelength of the lowest-energy absorption band of the fluorescent material, since this allows for smooth transfer of excitation energy from the TADF material to the fluorescent material, resulting in efficient light emission.

[0205] Furthermore, in order to efficiently generate singlet excitation energy from triplet excitation energy through reverse intersystem crossing, it is preferable that carrier recombination occurs in the TADF material. It is also preferable that the triplet excitation energy generated in the TADF material does not transfer to the triplet excitation energy of the fluorescent material. To this end, it is preferable that the fluorescent material has a protecting group around the luminophore (the skeleton responsible for light emission) possessed by the fluorescent material. The protecting group is preferably a substituent without a π bond, and is preferably a saturated hydrocarbon. Specific examples include alkyl groups having 3 to 10 carbon atoms, substituted or unsubstituted alicyclic groups having 3 to 10 carbon atoms, and trialkylsilyl groups having 3 to 10 carbon atoms. It is even more preferable that the protecting group has multiple protecting groups. Substituents without a π bond have poor carrier transport function, so the distance between the TADF material and the luminophore of the fluorescent material can be increased without significantly affecting carrier transport or carrier recombination. Here, the luminophore refers to the atomic group (skeleton) responsible for light emission in the fluorescent material. The luminophore preferably has a skeleton having a π bond, preferably contains an aromatic ring, and preferably has a fused aromatic ring or a fused heteroaromatic ring. Examples of such luminophores include a phenanthrene skeleton, a stilbene skeleton, an acridone skeleton, a phenoxazine skeleton, a phenothiazine skeleton, a naphthalene skeleton, an anthracene skeleton, a fluorene skeleton, a chrysene skeleton, a triphenylene skeleton, a tetracene skeleton, a pyrene skeleton, a perylene skeleton, a coumarin skeleton, a quinacridone skeleton, and a naphthobisbenzofuran skeleton. In particular, fluorescent materials having a naphthalene skeleton, an anthracene skeleton, a fluorene skeleton, a chrysene skeleton, a triphenylene skeleton, a tetracene skeleton, a pyrene skeleton, a perylene skeleton, a coumarin skeleton, a quinacridone skeleton, or a naphthobisbenzofuran skeleton are preferred because of their high fluorescence quantum yield.

[0206] When a fluorescent substance is used as the light-emitting substance in the light-emitting layer 113, a material having an acene skeleton, particularly an anthracene skeleton, is suitable as the host material. Using a substance having an anthracene skeleton as a host material for a fluorescent substance makes it possible to realize an light-emitting layer with both excellent luminous efficiency and durability. As a substance having an anthracene skeleton used as a host material, a diphenylanthracene skeleton, particularly a 9,10-diphenylanthracene skeleton, is preferred because it is chemically stable. Furthermore, a host material having a carbazole skeleton is preferred because it enhances hole injection and transport properties. However, a host material including a benzocarbazole skeleton in which a benzene ring is further condensed to carbazole is more preferred because the HOMO level is about 0.1 eV higher than that of a host material including a carbazole skeleton, making it easier for holes to enter. In particular, a host material including a dibenzocarbazole skeleton is preferred because the HOMO level is about 0.1 eV higher than that of a host material including a carbazole skeleton, making it easier for holes to enter, and it also has excellent hole transport properties and high heat resistance. Therefore, a more preferable host material is a substance having both a 9,10-diphenylanthracene skeleton and a carbazole skeleton (or a benzocarbazole skeleton or a dibenzocarbazole skeleton). From the viewpoint of the hole injection / transport property, a benzofluorene skeleton or a dibenzofluorene skeleton may be used instead of the carbazole skeleton. Furthermore, a dibenzofuran skeleton is preferable because it can ensure reliability without lowering the T1 level.

[0207] Examples of such substances include 9-phenyl-3-[4-(10-phenyl-9-anthryl)phenyl]-9H-carbazole (abbreviation: PCzPA), 3-[4-(1-naphthyl)phenyl]-9-phenyl-9H-carbazole (abbreviation: PCPN), 9-[4-(10-phenyl-9-anthryl)phenyl]-9H-carbazole (abbreviation: CzPA), 7-[4-(10-phenyl-9-anthryl)phenyl]-7H-dibenzo[c,g]carbazole (abbreviation: cgDBCzPA), 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]anthracene (abbreviation: FLPPA), 9-(1-naphthyl)-10-[4-(2-naphthyl)phenyl]anthracene (abbreviation: αN-βNPAnth), 9-(1-naphthyl)-10-(2-naphthyl)anthracene (abbreviation: α,βADN), 2-(10-phenylanthracen-9-yl)dibenzofuran, 2-(10-phenyl-9-anthryl)benzo Examples include zo[b]naphtho[2,3-d]furan (abbreviation: Bnf(II)PhA), 9-(2-naphthyl)-10-[3-(2-naphthyl)phenyl]anthracene (abbreviation: βN-mβNPAnth), 1-{4-[10-(biphenyl-4-yl)-9-anthryl]phenyl}-2-ethyl-1H-benzimidazole (abbreviation: EtBImPBPhA), etc. In particular, CzPA, cgDBCzPA, 2mBnfPPA, and PCzPA are preferred choices because they exhibit very good properties.

[0208] The host material may be a mixture of a plurality of substances. When a mixture of host materials is used, it is preferable to mix a substance having an electron-transporting property with a substance having a hole-transporting property. By mixing a substance having an electron-transporting property with a substance having a hole-transporting property, the transport property of the light-emitting layer 113 can be easily adjusted, and the recombination region can also be easily controlled. The weight ratio of the content of the substance having a hole-transporting property to the substance having an electron-transporting property is preferably 1:19 to 19:1.

[0209] A phosphorescent material can be used as part of the mixed host material. The phosphorescent material can be used as an energy donor that provides excitation energy to a fluorescent material when the fluorescent material is used as an emitting material.

[0210] These mixed materials may also form an exciplex. The exciplex is preferably formed by selecting a combination that forms an exciplex that emits light that overlaps with the lowest-energy absorption band of the light-emitting material, because this allows for smooth energy transfer and efficient light emission. Furthermore, this configuration is also preferable because it reduces the driving voltage.

[0211] At least one of the materials forming the exciplex may be a phosphorescent material, which allows triplet excitation energy to be efficiently converted into singlet excitation energy by reverse intersystem crossing.

[0212] As a combination of materials that efficiently form an exciplex, it is preferable that the HOMO level of the substance having hole-transporting properties be equal to or higher than the HOMO level of the substance having electron-transporting properties. It is also preferable that the LUMO level of the substance having hole-transporting properties be equal to or higher than the LUMO level of the substance having electron-transporting properties. The LUMO level and HOMO level of a material can be derived from the electrochemical properties (reduction potential and oxidation potential) of the material measured by cyclic voltammetry (CV).

[0213] The formation of an exciplex can be confirmed, for example, by comparing the emission spectra of a substance having hole-transporting properties, a substance having electron-transporting properties, and a mixed film obtained by mixing these materials, and observing the phenomenon that the emission spectrum of the mixed film is shifted to a longer wavelength than the emission spectra of each material (or has a new peak on the longer wavelength side). Alternatively, the formation of an exciplex can be confirmed by comparing the transient photoluminescence (PL) of a substance having hole-transporting properties, the transient PL of a substance having electron-transporting properties, and a mixed film obtained by mixing these materials, and observing differences in transient response, such as the transient PL lifetime of the mixed film having a longer-lifetime component or a larger proportion of delayed components than the transient PL lifetimes of each material. The above-mentioned transient PL may also be interpreted as transient electroluminescence (EL). That is, the formation of an exciplex can also be confirmed by comparing the transient EL of a substance having hole-transporting properties, the transient EL of a substance having electron-transporting properties, and a mixed film obtained by mixing these materials, and observing the differences in transient response.

[0214] The electron transport layer 114 is a layer containing a substance having an electron transport property. The substance having an electron transport property is a material having an electron mobility of 1×10 or more at a square root of an electric field strength [V / cm] of 600. −７ cm ２ / Vs or more, preferably 1×10 −６ cm ２ A substance having an electron mobility of 1 / Vs or more is preferred. Note that, other substances can be used as long as they have a higher electron transporting property than holes. Note that, as the organic compound, an organic compound having a π-electron-deficient heteroaromatic ring is preferred. As the organic compound having a π-electron-deficient heteroaromatic ring, for example, one or more of an organic compound including a heteroaromatic ring having an azole skeleton, an organic compound including a heteroaromatic ring having a pyridine skeleton, an organic compound including a heteroaromatic ring having a diazine skeleton, and an organic compound including a heteroaromatic ring having a triazine skeleton are preferred.

[0215] As a substance having electron transport properties that can be used for the electron-transport layer 114, organic compounds that can be used for the substance having electron transport properties in the light-emitting layer 113 can be used similarly. Among them, organic compounds including a heteroaromatic ring having a diazine skeleton, an organic compound including a heteroaromatic ring having a pyridine skeleton, and an organic compound including a heteroaromatic ring having a triazine skeleton are preferred because of their high reliability. In particular, organic compounds including a heteroaromatic ring having a diazine (pyrimidine or pyrazine) skeleton and an organic compound including a heteroaromatic ring having a triazine skeleton have high electron transport properties and contribute to reducing driving voltage. In particular, organic compounds having a phenanthroline skeleton, such as mTpPPhen, PnNPhen, and mPPhen2P, are preferred, and organic compounds having a phenanthroline dimer structure, such as mPPhen2P, are more preferred because of their excellent stability. Note that the electron-transport layer 114 is preferably made of an organic compound represented by the general formula (Ge1) described in Embodiment 1.

[0216] The electron transport layer 114 may have a stacked structure. A layer in the electron transport layer 114 having a stacked structure that is in contact with the light-emitting layer 113 may function as a hole-blocking layer. When the electron transport layer in contact with the light-emitting layer is made to function as a hole-blocking layer, it is preferable to use a material whose HOMO level is lower by 0.5 eV or more than the HOMO level of a material contained in the light-emitting layer 113.

[0217] A layer containing a compound or complex of an alkali metal or alkaline earth metal such as 8-hydroxyquinolinato-lithium (abbreviation: Liq), or 1,1′-pyridine-2,6-diyl-bis(1,3,4,6,7,8-hexahydro-2H-pyrimido[1,2-a]pyrimidine) (abbreviation: hpp2Py) may be provided as the electron-injection layer 115. The electron-injection layer 115 may be a layer made of a substance having an electron-transporting property containing an alkali metal, an alkaline earth metal, or a compound thereof.

[0218] Alternatively, a charge generation layer 116 may be provided instead of the electron injection layer 115 ( FIG. 1C ). The charge generation layer 116 is a layer capable of injecting holes into a layer in contact with the cathode side of the charge generation layer 116 and electrons into a layer in contact with the anode side of the charge generation layer 116 by applying a potential thereto. The charge generation layer 116 includes at least a p-type layer 117. The p-type layer 117 is preferably formed using the composite material listed above as a material that can be used to form the hole injection layer 111. The p-type layer 117 may also be formed by laminating a film containing an acceptor material and a film containing a hole transport material, both of which are materials that can be used to form the composite material. By applying a potential to the p-type layer 117, electrons are injected into the electron transport layer 114 and holes are injected into the cathode, thereby operating the light-emitting device.

[0219] It is preferable that the charge generating layer 116 be provided with either or both of an electron relay layer 118 and an electron injection buffer layer 119 in addition to the p-type layer 117 .

[0220] The electron relay layer 118 contains at least a substance having electron transport properties and has the function of smoothly transferring electrons by preventing interaction between the electron injection buffer layer 119 and the p-type layer 117. The LUMO level of the substance having electron transport properties contained in the electron relay layer 118 is preferably located between the LUMO level of the acceptor substance in the p-type layer 117 and the LUMO level of the substance contained in the layer of the electron transport layer 114 that is in contact with the charge generation layer 116. The specific energy level of the LUMO level of the substance having electron transport properties used in the electron relay layer 118 is preferably −5.0 eV or higher, preferably −5.0 eV or higher to −3.0 eV or lower, more preferably −4.30 eV or higher to −3.00 eV or lower, and more preferably −4.30 eV or higher to −3.30 eV or lower, because this can suppress an increase in driving voltage. As the substance having electron transport properties used in the electron relay layer 118, a phthalocyanine-based material or a metal complex having a metal-oxygen bond and an aromatic ligand is preferably used.

[0221] Specific examples of the substance having electron transport properties that can be used in the electron relay layer 118 include diquinoxalino[2,3-a:2′,3′-c]phenazine (abbreviation: HATNA), 2,3,8,9,14,15-hexafluorodiquinoxalino[2,3-a:2′,3′-c]phenazine (abbreviation: HATNA-F6), perylene tetracarboxylic acid derivatives such as 3,4,9,10-perylene tetracarboxylic diimide (abbreviation: PTCDI) and 3,4,9,10-perylene tetracarboxylic bis-benzimidazole (abbreviation: PTCBI), (C60-Ih)[5,6]fullerene (abbreviation: C60), and (C70-D5h)[5,6]fullerene (abbreviation: C70). Furthermore, a compound having a heterophane skeleton, which is a cyclophane skeleton containing a heterocycle, can be used. Examples of such a compound include phthalocyanine (abbreviation: H ２ Phthalocyanine compounds such as copper phthalocyanine (abbreviated as CuPc), zinc phthalocyanine (abbreviated as ZnPc), cobalt phthalocyanine (abbreviated as CoPc), iron phthalocyanine (abbreviated as FePc), tin phthalocyanine (abbreviated as SnPc), tin oxide phthalocyanine (abbreviated as SnOPc), titanium oxide phthalocyanine (abbreviated as TiOPc), vanadium oxide phthalocyanine (abbreviated as VOPc), and their derivatives can also be used. Phthalocyanine-based metal complexes such as copper phthalocyanine or zinc phthalocyanine, or 2,3,8,9,14,15-hexafluorodiquinoxalino[2,3-a:2',3'-c]phenazine are particularly preferred.

[0222] For the electron-injection buffer layer 119, it is preferable to use a material with high electron-injection properties, such as a metal or a metal compound, particularly an alkali metal, an alkaline earth metal, a rare earth metal, or a compound thereof (alkali metal compounds (including oxides such as lithium oxide, halides, and carbonates such as lithium carbonate and cesium carbonate), alkaline earth metal compounds (including oxides, halides, and carbonates), or rare earth metal compounds (including oxides, halides, and carbonates)).

[0223] When the electron-injection buffer layer 119 is formed to contain a substance having electron-transporting properties and a donor substance, the donor substance can be a metal or a metal compound, in particular, an alkali metal, an alkaline earth metal, a rare earth metal, or a compound thereof (alkali metal compounds (including oxides such as lithium oxide, halides, and carbonates such as lithium carbonate and cesium carbonate), alkaline earth metal compounds (including oxides, halides, and carbonates), or rare earth metal compounds (including oxides, halides, and carbonates)), or organic compounds such as tetrathianaphthacene (abbreviation: TTN), nickelocene, or decamethylnickelocene. Note that the substance having electron-transporting properties can be formed using the same material as the material constituting the electron-transporting layer 114 described above.

[0224] The second electrode 102 is an electrode including a cathode. The second electrode 102 may have a laminated structure, in which case the layer in contact with the organic compound layer 103 functions as the cathode. Materials that form the cathode include metals, alloys, electrically conductive compounds, and mixtures thereof, each having a small work function (specifically, 3.8 eV or less). Specific examples of such cathode materials include alkali metals such as lithium (Li) or cesium (Cs), elements belonging to Group 1 or Group 2 of the periodic table such as magnesium (Mg), calcium (Ca), and strontium (Sr), and alloys (MgAg, AlLi) and compounds (lithium fluoride (LiF), cesium fluoride (CsF), calcium fluoride (CaF), etc.) containing these elements. ２ However, by providing the electron injection layer 115 or a thin film of the above-mentioned material having a small work function between the second electrode 102 and the electron transport layer, various conductive materials such as Al, Ag, ITO, indium oxide-tin oxide containing silicon or silicon oxide can be used as the cathode regardless of the magnitude of the work function.

[0225] Note that the light-emitting device of one embodiment of the present invention can be a light-emitting device that emits light from the second electrode 102 side by forming the second electrode 102 using a material that transmits visible light.

[0226] These conductive materials can be formed into films by dry methods such as vacuum deposition or sputtering, inkjet methods, spin coating methods, etc. Alternatively, they may be formed by wet methods using a sol-gel method, or by wet methods using a paste of a metal material.

[0227] In addition, various methods, whether dry or wet, can be used to form the organic compound layer 103. For example, vacuum deposition, gravure printing, offset printing, screen printing, inkjet printing, spin coating, or the like may be used.

[0228] Furthermore, the above-mentioned electrodes or layers may be formed using different film formation methods.

[0229] Next, an embodiment of a light-emitting device having a configuration in which multiple light-emitting units are stacked (also referred to as a stacked element or a tandem element) will be described with reference to FIG. 2. This light-emitting device has multiple light-emitting units between an anode and a cathode. One light-emitting unit has a configuration substantially similar to that of the organic compound layer 103 shown in FIG. 1A. In other words, the light-emitting device shown in FIG. 2 is a light-emitting device having multiple light-emitting units, and the light-emitting device shown in FIG. 1A or 1B can be said to be a light-emitting device having one light-emitting unit.

[0230] 2, a first light-emitting unit 511 and a second light-emitting unit 512 are stacked between a first electrode 501 and a second electrode 502, and an intermediate layer 513 is provided between the first light-emitting unit 511 and the second light-emitting unit 512. The first electrode 501 and the second electrode 502 correspond to the first electrode 101 and the second electrode 102 in FIG. 1A, respectively, and the same electrodes as those described in the description of FIG. 1A can be applied to them. In addition, the first light-emitting unit 511 and the second light-emitting unit 512 may have the same configuration or different configurations.

[0231] The intermediate layer 513 has a function of injecting electrons into one light-emitting unit and injecting holes into the other light-emitting unit when a voltage is applied between the first electrode 501 and the second electrode 502. That is, in FIG. 2 , when a voltage is applied so that the potential of the anode is higher than the potential of the cathode, the intermediate layer 513 only needs to inject electrons into the first light-emitting unit 511 and inject holes into the second light-emitting unit 512.

[0232] The intermediate layer 513 is preferably formed to have the same structure as the charge generation layer 116 described in FIG. 1B. A composite material of an organic compound and a metal oxide has excellent carrier injection and carrier transport properties, and therefore can achieve low-voltage driving and low-current driving. Note that when the anode-side surface of the light-emitting unit is in contact with the intermediate layer 513, the intermediate layer 513 can also serve as a hole injection layer for the light-emitting unit, and therefore the light-emitting unit does not need to be provided with a hole injection layer.

[0233] Furthermore, when the electron injection buffer layer 119 is provided in the intermediate layer 513, the electron injection buffer layer 119 plays the role of an electron injection layer in the light-emitting unit on the anode side, and therefore, it is not necessarily necessary to form an electron injection layer in the light-emitting unit on the anode side.

[0234] Although the light-emitting device having two light-emitting units has been described in FIG. 2 , the present invention can be similarly applied to a light-emitting device having three or more stacked light-emitting units. By disposing a plurality of light-emitting units between a pair of electrodes and separating them with an intermediate layer 513, as in the light-emitting device according to this embodiment, it is possible to realize a device that can emit high-luminance light while maintaining a low current density and that has a long life. Furthermore, it is possible to realize a light-emitting device that can be driven at a low voltage and consumes low power. In this case, it is more preferable that the first light-emitting unit and the second light-emitting unit emit light of the same hue.

[0235] Furthermore, by making the light-emitting units emit light of different hues, it is possible to obtain light of a desired color from the light-emitting device as a whole. For example, in a light-emitting device having two light-emitting units, it is possible to obtain a light-emitting device that emits white light from the entire device by obtaining light of red and green hues from the first light-emitting unit and light of blue hues from the second light-emitting unit.

[0236] Furthermore, each layer and electrode such as the organic compound layer 103, the first light-emitting unit 511, the second light-emitting unit 512, and the charge generation layer can be formed by, for example, a vapor deposition method (including a vacuum vapor deposition method), a droplet discharge method (also called an ink-jet method), a coating method, a gravure printing method, etc. Furthermore, they may contain a low-molecular-weight material, a medium-molecular-weight material (including an oligomer and a dendrimer), or a polymer material.

[0237] (Embodiment 3) In this embodiment, a display device manufactured using the light-emitting device described in Embodiments 1 and 2 will be described with reference to Fig. 3. Fig. 3A is a top view showing the display device, and Fig. 3B is a cross-sectional view taken along lines A-B and C-D in Fig. 3A. This display device includes a driver circuit section (source line driver circuit) 601, a pixel section 602, and a driver circuit section (gate line driver circuit) 603, all of which are shown by dotted lines, to control light emission from the light-emitting device. Also, 604 is a sealing substrate, 605 is a sealant, and the inside surrounded by the sealant 605 is a space 607.

[0238] The lead wiring 608 is wiring for transmitting signals input to the source line driver circuit 601 and the gate line driver circuit 603, and receives video signals, clock signals, start signals, reset signals, etc. from an FPC (flexible print circuit) 609, which serves as an external input terminal. Although only the FPC is shown here, a printed wiring board (PWB) may be attached to this FPC. The display device in this specification includes not only the display device itself, but also a state in which an FPC or PWB is attached to it.

[0239] Next, the cross-sectional structure will be described with reference to Fig. 3B. A driver circuit portion and a pixel portion are formed on an element substrate 610, and here, a source line driver circuit 601, which is the driver circuit portion, and one pixel in a pixel portion 602 are shown.

[0240] The element substrate 610 may be made of a substrate made of glass, quartz, organic resin, metal, alloy, semiconductor, or the like, or a plastic substrate made of FRP (Fiber Reinforced Plastics), PVF (Polyvinyl Fluoride), polyester, acrylic resin, or the like.

[0241] The structure of the transistors used in the pixels and the driver circuits is not particularly limited. For example, they may be inverted staggered transistors or staggered transistors. Furthermore, they may be top-gate or bottom-gate transistors. The semiconductor material used for the transistors is not particularly limited, and examples thereof include silicon, germanium, silicon carbide, and gallium nitride. Alternatively, an oxide semiconductor containing at least one of indium, gallium, and zinc, such as an In—Ga—Zn-based metal oxide, may be used.

[0242] The crystallinity of a semiconductor material used for a transistor is not particularly limited, and any of an amorphous semiconductor and a crystalline semiconductor (a microcrystalline semiconductor, a polycrystalline semiconductor, a single crystal semiconductor, or a semiconductor having a crystalline region in part) may be used. The use of a crystalline semiconductor is preferable because it can suppress deterioration of transistor characteristics.

[0243] Here, it is preferable to use an oxide semiconductor for the transistors provided in the pixel and the driver circuit, as well as for semiconductor devices such as transistors used in touch sensors, which will be described later. In particular, it is preferable to use an oxide semiconductor having a wider band gap than silicon. By using an oxide semiconductor having a wider band gap than silicon, the current in the off state of the transistor can be reduced.

[0244] The oxide semiconductor preferably contains at least indium (In) or zinc (Zn), and more preferably contains an oxide represented by In-M-Zn-based oxide (M is a metal such as Al, Ti, Ga, Ge, Y, Zr, Sn, La, Ce, or Hf).

[0245] In particular, it is preferable to use, as the semiconductor layer, an oxide semiconductor film which has a plurality of crystal parts whose c-axes are oriented perpendicular to a surface on which the semiconductor layer is formed or a top surface of the semiconductor layer and which does not have grain boundaries between adjacent crystal parts.

[0246] By using such a material for the semiconductor layer, fluctuations in electrical characteristics are suppressed, and a highly reliable transistor can be realized.

[0247] Furthermore, a transistor having the above-described semiconductor layer can retain charge accumulated in a capacitor through the transistor for a long period of time due to its low off-state current. By applying such a transistor to a pixel, it is possible to stop a driver circuit while maintaining the gray level of each pixel. As a result, an electronic device with extremely low power consumption can be realized.

[0248] For example, to stabilize the characteristics of a transistor, it is preferable to provide a base film. The base film can be formed as a single layer or a stacked layer using an inorganic insulating film such as a silicon oxide film, a silicon nitride film, a silicon oxynitride film, or a silicon nitride oxide film. The base film can be formed by a sputtering method, a CVD (Chemical Vapor Deposition) method (such as a plasma CVD method, a thermal CVD method, or a MOCVD (Metal Organic CVD) method), an ALD (Atomic Layer Deposition) method, a coating method, a printing method, or the like. Note that the base film need not be provided if it is not necessary.

[0249] The FET 623 indicates one of the transistors formed in the drive circuit section 601. The drive circuit may be formed of various CMOS circuits, PMOS circuits, or NMOS circuits. Although this embodiment shows a driver-integrated type in which the drive circuit is formed on a substrate, this is not necessarily required, and the drive circuit may also be formed externally rather than on the substrate.

[0250] Furthermore, the pixel portion 602 is formed by a plurality of pixels including a switching FET 611, a current control FET 612, and a first electrode 613 electrically connected to the drain of the FET, but is not limited to this, and the pixel portion may be formed by combining three or more FETs and a capacitance element.

[0251] An insulator 614 is formed to cover an end portion of the first electrode 613. Here, the insulator 614 can be formed by using a positive photosensitive acrylic resin film.

[0252] Furthermore, in order to improve the coverage of organic compound layers and the like to be formed later, a curved surface having a curvature is formed at the upper or lower end of the insulator 614. For example, when a positive photosensitive acrylic resin is used as the material for the insulator 614, it is preferable to provide a curved surface having a curvature radius (0.2 μm to 3 μm) only at the upper end of the insulator 614. Furthermore, either a negative photosensitive resin or a positive photosensitive resin can be used as the insulator 614.

[0253] An organic compound layer 616 and a second electrode 617 are formed on the first electrode 613. Here, it is desirable to use a material with a large work function as the material used for the first electrode 613, which functions as an anode. For example, a single layer film such as an ITO film, an indium tin oxide film containing silicon, an indium oxide film containing 2 to 20 wt % zinc oxide, a titanium nitride film, a chromium film, a tungsten film, a Zn film, or a Pt film can be used. It is also possible to use a stacked structure of a titanium nitride film and a film mainly composed of aluminum, or a three-layer structure of a titanium nitride film, a film mainly composed of aluminum, and a titanium nitride film. The stacked structure provides low resistance as a wiring, good ohmic contact, and the first electrode 613 can further function as an anode.

[0254] The organic compound layer 616 is formed by various methods such as a vapor deposition method using a vapor deposition mask, an inkjet method, or a spin coating method. The organic compound layer 616 includes the structures described in Embodiment Mode 1 and Embodiment Mode 2. Other materials constituting the organic compound layer 616 may be low-molecular-weight compounds or high-molecular-weight compounds (including oligomers and dendrimers).

[0255] Furthermore, as a material used for the second electrode 617 formed on the organic compound layer 616 and functioning as a cathode, a material having a small work function (Al, Mg, Li, Ca, or alloys and compounds thereof (MgAg, MgIn, AlLi, etc.)) is preferably used. Note that, when light generated in the organic compound layer 616 is transmitted through the second electrode 617, it is preferable to use a stack of a thin metal thin film and a transparent conductive film (ITO, indium oxide containing 2 to 20 wt % zinc oxide, indium tin oxide containing silicon, zinc oxide (ZnO), etc.) as the second electrode 617.

[0256] Note that a light-emitting device is formed with the first electrode 613, the organic compound layer 616, and the second electrode 617. The light-emitting device is the light-emitting device described in Embodiment Mode 1 and Embodiment Mode 2. Note that a pixel portion is formed with a plurality of light-emitting devices, but the display device in this embodiment mode may include both the light-emitting devices described in Embodiment Mode 1 and Embodiment Mode 2 and light-emitting devices having other structures.

[0257] Furthermore, by bonding the sealing substrate 604 to the element substrate 610 with a sealing material 605, a structure is formed in which a light-emitting device 618 is provided in a space 607 surrounded by the element substrate 610, the sealing substrate 604, and the sealing material 605. The space 607 is filled with a filler, and in some cases, the space is filled with an inert gas (nitrogen, argon, etc.), or with a sealing material. A recess is formed in the sealing substrate, and by providing a desiccant therein, deterioration due to the influence of moisture can be suppressed, which is a preferable configuration.

[0258] It is preferable to use epoxy resin or glass frit for the sealing material 605. It is also desirable that these materials are as moisture and oxygen impermeable as possible. In addition, materials that can be used for the sealing substrate 604 include glass substrates, quartz substrates, and plastic substrates made of FRP (Fiber Reinforced Plastics), PVF (Polyvinyl Fluoride), polyester, acrylic resin, etc.

[0259] Although not shown in FIG. 3 , a protective film may be provided on the second electrode. The protective film may be formed of an organic resin film or an inorganic insulating film. The protective film may also be formed so as to cover the exposed portion of the sealing material 605. The protective film may also be provided so as to cover the surfaces and side surfaces of the pair of substrates, the exposed side surfaces of the sealing layer, the insulating layer, and the like.

[0260] The protective film can be made of a material that is impermeable to impurities such as water, and therefore can effectively prevent impurities such as water from diffusing from the outside to the inside.

[0261] The protective film may be made of an oxide, nitride, fluoride, sulfide, ternary compound, metal, polymer, or the like. For example, a material containing aluminum oxide, hafnium oxide, hafnium silicate, lanthanum oxide, silicon oxide, strontium titanate, tantalum oxide, titanium oxide, zinc oxide, niobium oxide, zirconium oxide, tin oxide, yttrium oxide, cerium oxide, scandium oxide, erbium oxide, vanadium oxide, indium oxide, or the like; a material containing aluminum nitride, hafnium nitride, silicon nitride, tantalum nitride, titanium nitride, niobium nitride, molybdenum nitride, zirconium nitride, or gallium nitride, or the like; a nitride containing titanium and aluminum, an oxide containing titanium and aluminum, an oxide containing aluminum and zinc, a sulfide containing manganese and zinc, a sulfide containing cerium and strontium, an oxide containing erbium and aluminum, or an oxide containing yttrium and zirconium, or the like.

[0262] The protective film is preferably formed using a film formation method that provides good step coverage. One such method is atomic layer deposition (ALD). It is preferable to use a material that can be formed using the ALD method for the protective film. By using the ALD method, it is possible to form a dense protective film with reduced defects such as cracks and pinholes, or with a uniform thickness. Furthermore, it is possible to reduce damage to the workpiece when forming the protective film.

[0263] For example, by forming a protective film using the ALD method, it is possible to form a uniform protective film with few defects on surfaces having complex uneven shapes, including the top, side, and back surfaces of the touch panel.

[0264] In this manner, a display device manufactured using the light-emitting device described in Embodiment 1 or 2 can be obtained.

[0265] The display device in this embodiment uses the light-emitting device described in Embodiment 1 or 2, and therefore, a display device with favorable characteristics can be obtained. Specifically, since the light-emitting devices described in Embodiments 1 and 2 have high emission efficiency, a display device with low power consumption can be obtained. In addition, since the light-emitting devices described in Embodiments 1 and 2 have high reliability, a display device with high reliability can be obtained.

[0266] This embodiment mode can be freely combined with other embodiment modes.

[0267] 4A and 4B, a display device is formed by forming a plurality of light-emitting devices 130 over an insulating layer 175. In this embodiment, a display device according to another embodiment of the present invention will be described in detail.

[0268] The display device 100 has a pixel section 177 in which a plurality of pixels 178 are arranged in a matrix. The pixel 178 has a sub-pixel 110R, a sub-pixel 110G, and a sub-pixel 110B.

[0269] In this specification and the like, when describing matters common to, for example, the subpixels 110R, 110G, and 110B, they may be referred to as the subpixels 110. When describing matters common to other components distinguished by alphabets, they may also be described using symbols without the alphabets.

[0270] The sub-pixel 110R emits red light, the sub-pixel 110G emits green light, and the sub-pixel 110B emits blue light. This allows an image to be displayed in the pixel unit 177. Note that in this embodiment, sub-pixels of three colors, red (R), green (G), and blue (B), are described as an example, but combinations of sub-pixels of other colors may also be used. Furthermore, the number of sub-pixels is not limited to three, and may be four or more. Examples of four sub-pixels include sub-pixels of four colors, R, G, B, and white (W), sub-pixels of four colors, R, G, B, and yellow (Y), and sub-pixels of R, G, B, and infrared light (IR).

[0271] In this specification, the row direction may be referred to as the X direction, and the column direction may be referred to as the Y direction. The X direction and the Y direction intersect, for example, perpendicularly.

[0272] 4A shows an example in which subpixels of different colors are arranged side by side in the X direction, and subpixels of the same color are arranged side by side in the Y direction. Note that subpixels of different colors may also be arranged side by side in the Y direction, and subpixels of the same color may also be arranged side by side in the X direction.

[0273] A connection portion 140 and a region 141 may be provided outside the pixel portion 177. When the region 141 is provided, the region 141 is provided between the pixel portion 177 and the connection portion 140. When the region 141 is provided, an organic compound layer is provided in the region 141. Furthermore, a conductive layer 151C is provided in the connection portion 140.

[0274] 4 shows an example in which the region 141 and the connection portion 140 are located on the right side of the pixel portion 177, but the positions of the region 141 and the connection portion 140 are not particularly limited. The region 141 and the connection portion 140 may be singular or plural.

[0275] Fig. 4B is an example of a cross-sectional view taken along dashed line A1-A2 in Fig. 4A. As shown in Fig. 4B, display device 100 has insulating layer 171, conductive layer 172 on insulating layer 171, insulating layer 173 on insulating layer 171 and on conductive layer 172, insulating layer 174 on insulating layer 173, and insulating layer 175 on insulating layer 174. Insulating layer 171 is provided on a substrate (not shown). Insulating layer 175, insulating layer 174, and insulating layer 173 have openings that reach conductive layer 172, and plugs 176 are provided to fill the openings.

[0276] In the pixel section 177, the light-emitting device 130 is provided on the insulating layer 175 and the plug 176. A protective layer 131 is provided to cover the light-emitting device 130. The substrate 120 is bonded to the protective layer 131 by a resin layer 122. Preferably, an inorganic insulating layer 125 and an insulating layer 127 on the inorganic insulating layer 125 are provided between adjacent light-emitting devices 130.

[0277] Although Figure 4B shows multiple cross sections of the inorganic insulating layer 125 and the insulating layer 127, when viewing the display device 100 from above, it is preferable that the inorganic insulating layer 125 and the insulating layer 127 are each connected into one.

[0278] 4B shows light emitting device 130 as light emitting device 130R, light emitting device 130G, and light emitting device 130B. Light emitting device 130R, light emitting device 130G, and light emitting device 130B emit light of different colors. For example, light emitting device 130R can emit red light, light emitting device 130G can emit green light, and light emitting device 130B can emit blue light. Furthermore, light emitting device 130R, light emitting device 130G, or light emitting device 130B may emit other visible light or infrared light.

[0279] The display device of one embodiment of the present invention can be, for example, a top-emission type in which light is emitted in a direction opposite to a substrate on which a light-emitting device is formed. Note that the display device of one embodiment of the present invention may also be a bottom-emission type.

[0280] The light-emitting device 130R has a first electrode 101R (pixel electrode) composed of a conductive layer 151R and a conductive layer 152R, an organic compound layer 103R on the first electrode, a common layer 104 on the organic compound layer 103R, and a second electrode (common electrode) 102 on the common layer. Note that the common layer 104 may or may not be provided, but it is preferable that the common layer 104 be provided because it can reduce damage to the organic compound layer 103R during processing.

[0281] The light-emitting device 130G has a first electrode 101G (pixel electrode) composed of a conductive layer 151G and a conductive layer 152G, an organic compound layer 103G on the first electrode, a common layer 104 on the organic compound layer 103G, and a second electrode (common electrode) 102 on the common layer. Note that the common layer 104 may or may not be provided, but it is preferable that the common layer 104 be provided because it can reduce damage to the organic compound layer 103G during processing.

[0282] The light-emitting device 130B has the structure described in Embodiments 1 and 2. It includes a first electrode 101B (pixel electrode) including a conductive layer 151B and a conductive layer 152B, an organic compound layer 103B on the first electrode, a common layer 104 on the organic compound layer 103B, and a second electrode (common electrode) 102 on the common layer. Note that the common layer 104 may or may not be provided, but is preferably provided because it can reduce damage to the organic compound layer 103B during processing.

[0283] The common layer 104 is preferably any one of an electron injection layer, an electron transport layer, and a stacked structure of an electron transport layer and an electron injection layer, and more preferably an electron injection layer. In addition, when the common layer 104 is an electron transport layer, the electron transport layer preferably has a stacked structure, and it is more preferable that the layer on the second electrode side of the stacked layers is the common layer 104 and the layer on the light-emitting layer side is the organic compound layer 103.

[0284] Furthermore, since light-emitting device 130R and light-emitting device 130G are also light-emitting devices fabricated through a photolithography process, an increase in drive voltage due to the photolithography process is suppressed, and light-emitting devices with a low drive voltage can be obtained.

[0285] One of the pixel electrode and the common electrode of the light-emitting device 130 functions as an anode, and the other functions as a cathode. In the following description, unless otherwise specified, the pixel electrode functions as an anode and the common electrode functions as a cathode.

[0286] The organic compound layer 103R, the organic compound layer 103G, and the organic compound layer 103B are independent island-shaped layers for each light-emitting device or for each emitted color. By providing the organic compound layer 103 in an island shape for each light-emitting device 130, leakage current between adjacent light-emitting devices 130 can be suppressed even in a high-resolution display device. This makes it possible to prevent crosstalk and realize a display device with extremely high contrast. In particular, a display device with high current efficiency at low brightness can be realized.

[0287] The island-shaped organic compound layer 103 is formed by depositing an EL film and processing the EL film using a photolithography method.

[0288] The organic compound layer 103 is preferably provided so as to cover the top and side surfaces of the first electrode (pixel electrode) of the light-emitting device 130. This makes it easier to increase the aperture ratio of the display device 100 compared to a configuration in which the end of the organic compound layer 103 is located inside the end of the pixel electrode. Furthermore, covering the side surfaces of the pixel electrode of the light-emitting device 130 with the organic compound layer 103 can prevent the pixel electrode and the second electrode 102 from coming into contact with each other, thereby preventing short circuits in the light-emitting device 130.

[0289] In the display device of one embodiment of the present invention, the first electrode (pixel electrode) of the light-emitting device preferably has a stacked-layer structure. For example, in the example shown in FIG. 4B , the first electrode of the light-emitting device 130 has a stacked-layer structure of a conductive layer 151 and a conductive layer 152.

[0290] For example, a metal material can be used as the conductive layer 151. Specifically, metals such as aluminum (Al), titanium (Ti), chromium (Cr), manganese (Mn), iron (Fe), cobalt (Co), nickel (Ni), copper (Cu), gallium (Ga), zinc (Zn), indium (In), tin (Sn), molybdenum (Mo), tantalum (Ta), tungsten (W), palladium (Pd), gold (Au), platinum (Pt), silver (Ag), yttrium (Y), and neodymium (Nd), as well as alloys containing appropriate combinations of these metals, can also be used.

[0291] An oxide containing one or more selected from indium, tin, zinc, gallium, titanium, aluminum, and silicon can be used for the conductive layer 152. For example, it is preferable to use a conductive oxide containing one or more of indium oxide, indium tin oxide, indium zinc oxide, zinc oxide, zinc oxide containing gallium, titanium oxide, indium zinc oxide containing gallium, indium zinc oxide containing aluminum, indium tin oxide containing silicon, and indium zinc oxide containing silicon. In particular, indium tin oxide containing silicon has a large work function, for example, a work function of 4.0 eV or more, and therefore can be suitably used for the conductive layer 152.

[0292] The conductive layer 151 may have a stacked structure of multiple layers containing different materials, and the conductive layer 152 may have a stacked structure of multiple layers containing different materials. In this case, the conductive layer 151 may include a layer containing a material that can be used for the conductive layer 152, such as a conductive oxide, or the conductive layer 152 may include a layer containing a material that can be used for the conductive layer 151, such as a metal material. For example, when the conductive layer 151 has a stacked structure of two or more layers, a layer in contact with the conductive layer 152 can be a layer containing a material that can be used for the conductive layer 152.

[0293] Note that the side surface of the conductive layer 151 preferably has a tapered shape. Specifically, the side surface of the conductive layer 151 preferably has a tapered shape with a taper angle of less than 90°. In this case, the conductive layer 152 provided along the side surface of the conductive layer 151 also has a tapered shape. By tapering the side surface of the conductive layer 152, coverage of the organic compound layer 103 provided along the side surface of the conductive layer 152 can be improved.

[0294] Next, an example of a method for manufacturing the display device 100 having the structure shown in FIG. 4A will be described with reference to FIGS.

[0295] [Fabrication Method Example 1] Thin films (insulating films, semiconductor films, conductive films, etc.) constituting a display device can be formed using a sputtering method, a chemical vapor deposition (CVD) method, a vacuum evaporation method, a pulsed laser deposition (PLD) method, an ALD method, or the like.

[0296] Furthermore, thin films (insulating films, semiconductor films, conductive films, etc.) constituting the display device can be formed by wet film formation methods such as spin coating, dipping, spray coating, inkjet, dispensing, screen printing, offset printing, doctor knife method, slit coating, roll coating, curtain coating, or knife coating.

[0297] Furthermore, when processing the thin films that constitute the display device, they can be processed using, for example, photolithography.

[0298] In photolithography, the light used for exposure may be, for example, i-line (wavelength 365 nm), g-line (wavelength 436 nm), h-line (wavelength 405 nm), or a mixture of these. Other light sources that can be used include ultraviolet light, KrF laser light, and ArF laser light. Exposure may also be performed by immersion exposure technology. Extreme ultraviolet (EUV) light or X-rays may also be used as the light used for exposure. An electron beam may also be used instead of the light used for exposure.

[0299] The thin film can be etched by dry etching, wet etching, sandblasting, or the like.

[0300] 5A, an insulating layer 171 is formed on a substrate (not shown). Subsequently, conductive layers 172 and 179 are formed on the insulating layer 171, and an insulating layer 173 is formed on the insulating layer 171 so as to cover the conductive layers 172 and 179. Subsequently, an insulating layer 174 is formed on the insulating layer 173, and an insulating layer 175 is formed on the insulating layer 174.

[0301] The substrate may be a substrate having heat resistance sufficient to withstand at least a subsequent heat treatment, such as a glass substrate, a quartz substrate, a sapphire substrate, a ceramic substrate, an organic resin substrate, a single crystal semiconductor substrate made of silicon, silicon carbide, or the like, a polycrystalline semiconductor substrate, a compound semiconductor substrate made of silicon germanium, or the like, or an SOI substrate.

[0302] Subsequently, openings are formed in the insulating layers 175, 174, and 173, reaching the conductive layer 172. Subsequently, plugs 176 are formed so as to fill the openings.

[0303] Subsequently, a conductive film 151f, which will later become the conductive layers 151R, 151G, 151B, and 151C, is formed on the plugs 176 and the insulating layer 175. The conductive film 151f can be made of, for example, a metal material.

[0304] Next, a resist mask 191 is formed over the conductive film 151f. The resist mask 191 can be formed by applying a photosensitive material (photoresist) and then performing exposure and development.

[0305] 5B, the conductive film 151f is removed from the region that does not overlap with the resist mask 191. In this way, the conductive layer 151 is formed.

[0306] 5C, the resist mask 191 is removed by, for example, ashing using oxygen plasma.

[0307] Next, as shown in FIG. 5D , an insulating film 156f, which will later become insulating layers 156R, 156G, 156B, and 156C, is formed on the conductive layer 151R, the conductive layer 151G, the conductive layer 151B, the conductive layer 151C, and the insulating layer 175.

[0308] The insulating film 156f can be an inorganic insulating film such as an insulating oxide film, an insulating nitride film, an insulating oxynitride film, or an insulating nitride oxide film, for example, a silicon oxynitride film.

[0309] Subsequently, as shown in FIG. 5E, the insulating film 156f is processed to form insulating layers 156R, 156G, 156B, and 156C.

[0310] 6A , a conductive film 152f is formed over the conductive layer 151R, the conductive layer 151G, the conductive layer 151B, the conductive layer 151C, the insulating layer 156R, the insulating layer 156G, the insulating layer 156B, the insulating layer 156C, and the insulating layer 175. The conductive film 152f may be formed using, for example, a conductive oxide. The conductive film 152f may be a stacked film.

[0311] Subsequently, as shown in FIG. 6B, the conductive film 152f is processed to form conductive layers 152R, 152G, 152B, and 152C.

[0312] 6C, the EL film 103Rf is formed on the conductive layer 152R, the conductive layer 152G, the conductive layer 152B, and the insulating layer 175. Note that, as shown in FIG. 6C, the EL film 103Rf is not formed on the conductive layer 152C.

[0313] Subsequently, as shown in FIG. 6C, a sacrificial film 158f and a mask film 159Rf are formed.

[0314] By providing the sacrificial film 158Rf on the EL film 103Rf, damage to the EL film 103Rf during the manufacturing process of the display device can be reduced, and the reliability of the light-emitting device can be improved.

[0315] The sacrificial film 158Rf is made of a film that is highly resistant to the processing conditions of the EL film 103Rf, specifically, a film that has a large etching selectivity with respect to the EL film 103Rf.The mask film 159Rf is made of a film that has a large etching selectivity with respect to the sacrificial film 158Rf.

[0316] The sacrificial film 158Rf and the mask film 159Rf are formed at a temperature lower than the heat-resistant temperature of the EL film 103Rf. The substrate temperature when forming the sacrificial film 158Rf and the mask film 159Rf is typically 200° C. or lower, preferably 150° C. or lower, more preferably 120° C. or lower, more preferably 100° C. or lower, and even more preferably 80° C. or lower.

[0317] It is preferable to use a film that can be removed by wet etching for the sacrificial film 158Rf and the mask film 159Rf.

[0318] The sacrificial film 158Rf formed on and in contact with the EL film 103Rf is preferably formed using a formation method that causes less damage to the EL film 103Rf than the mask film 159Rf. For example, the ALD method or the vacuum deposition method is more preferable than the sputtering method.

[0319] The sacrificial film 158Rf and the mask film 159Rf may each be made of one or more of a metal film, an alloy film, a metal oxide film, a semiconductor film, an organic insulating film, an inorganic insulating film, or the like.

[0320] The sacrificial film 158Rf and the mask film 159Rf can be made of metal materials such as gold, silver, platinum, magnesium, nickel, tungsten, chromium, molybdenum, iron, cobalt, copper, palladium, titanium, aluminum, yttrium, zirconium, and tantalum, or alloy materials containing such metal materials. It is particularly preferable to use a low-melting-point material such as aluminum or silver. Using a metal material capable of blocking ultraviolet rays for one or both of the sacrificial film 158Rf and the mask film 159Rf is preferable because it can prevent ultraviolet rays from being irradiated onto the EL film 103Rf and suppress deterioration of the EL film 103Rf.

[0321] Furthermore, for the sacrificial film 158Rf and the mask film 159Rf, metal oxides such as In—Ga—Zn oxide, indium oxide, In—Zn oxide, In—Sn oxide, indium titanium oxide (In—Ti oxide), indium tin zinc oxide (In—Sn—Zn oxide), indium titanium zinc oxide (In—Ti—Zn oxide), indium gallium tin zinc oxide (In—Ga—Sn—Zn oxide), and indium tin oxide containing silicon can be used, respectively.

[0322] In addition, in the above metal oxide, an element M (wherein M is one or more elements selected from aluminum, silicon, boron, yttrium, copper, vanadium, beryllium, titanium, iron, nickel, germanium, zirconium, molybdenum, lanthanum, cerium, neodymium, hafnium, tantalum, tungsten, and magnesium) may be used instead of gallium.

[0323] The sacrificial film 158Rf and the mask film 159Rf are preferably made of a semiconductor material such as silicon or germanium, which has a high affinity with the semiconductor manufacturing process. Alternatively, compounds containing the semiconductor materials can be used.

[0324] The sacrificial film 158Rf and the mask film 159Rf may be made of various inorganic insulating films, and an oxide insulating film is particularly preferable because it has higher adhesion to the EL film 103Rf than a nitride insulating film.

[0325] 6C, a resist mask 190R is formed. The resist mask 190R can be formed by applying a photosensitive material (photoresist) and then performing exposure and development.

[0326] The resist mask 190R is provided in a position overlapping with the conductive layer 152R. The resist mask 190R is preferably provided also in a position overlapping with the conductive layer 152C. This can prevent the conductive layer 152C from being damaged during the manufacturing process of the display device.

[0327] 6D , a resist mask 190R is used to remove a portion of the mask film 159Rf to form a mask layer 159R. The mask layer 159R remains on the conductive layer 152R and the conductive layer 152C. The resist mask 190R is then removed. The mask layer 159R is then used as a mask (also referred to as a hard mask) to remove a portion of the sacrificial film 158Rf to form a sacrificial layer 158R.

[0328] By using the wet etching method, damage to the EL film 103Rf during processing of the sacrificial film 158Rf and the mask film 159Rf can be reduced compared to when using the dry etching method. When using the wet etching method, it is preferable to use a chemical solution using, for example, a developer, a tetramethylammonium hydroxide aqueous solution (TMAH), dilute hydrofluoric acid, oxalic acid, phosphoric acid, acetic acid, nitric acid, or a mixture thereof.

[0329] Furthermore, when dry etching is used to process the sacrificial film 158Rf, deterioration of the EL film 103Rf can be suppressed by not using a gas containing oxygen as the etching gas.

[0330] The resist mask 190R can be removed in the same manner as the resist mask 191.

[0331] 6D, the EL film 103Rf is processed to form the organic compound layer 103R. For example, the mask layer 159R and the sacrificial layer 158R are used as a hard mask to remove a portion of the EL film 103Rf, thereby forming the organic compound layer 103R.

[0332] 6D, a laminated structure of the organic compound layer 103R, the sacrificial layer 158R, and the mask layer 159R remains on the conductive layer 152R, and the conductive layers 152G and 152B are exposed.

[0333] The EL film 103Rf is preferably processed by anisotropic etching, particularly anisotropic dry etching, or wet etching may be used.

[0334] When dry etching is used, deterioration of the EL film 103Rf can be suppressed by not using a gas containing oxygen as the etching gas.

[0335] Alternatively, a gas containing oxygen may be used as the etching gas. By using an etching gas containing oxygen, the etching rate can be increased. Therefore, etching can be performed under low power conditions while maintaining a sufficiently high etching rate. This can reduce damage to the EL film 103Rf. Furthermore, problems such as adhesion of reaction products that occur during etching can be reduced.

[0336] When dry etching is used, for example, H ２ , C.F. ４ , C ４ F ８ , S.F. ６ , CHF ３ , Cl ２ , H ２ O, BCl ３ It is preferable to use a gas containing one or more of Group 18 elements such as He and Ar as the etching gas. Alternatively, it is preferable to use a gas containing one or more of these elements and oxygen as the etching gas. Alternatively, oxygen gas may be used as the etching gas.

[0337] Subsequently, as shown in FIG. 7A, an EL film 103Gf, which will later become the organic compound layer 103G, is formed.

[0338] The EL film 103Gf can be formed by the same method as that used to form the EL film 103Rf, and can have the same structure as the EL film 103Rf.

[0339] Next, a sacrificial film 158Gf and a mask film 159Gf are formed in this order. Then, a resist mask 190G is formed in a position overlapping the conductive layer 152G. The materials and forming methods of the sacrificial film 158Gf and the mask film 159Gf are the same as those applicable to the sacrificial film 158Rf and the mask film 159Rf. The materials and forming methods of the resist mask 190G are the same as those applicable to the resist mask 190R.

[0340] 7B, a resist mask 190G is used to remove a portion of the mask film 159Gf to form a mask layer 159G. The mask layer 159G remains on the conductive layer 152G. The resist mask 190G is then removed. The mask layer 159G is then used as a mask to remove a portion of the sacrificial film 158Gf to form a sacrificial layer 158G. The EL film 103Gf is then processed to form an organic compound layer 103G.

[0341] 7C, the EL film 103Bf is formed. The EL film 103Bf can be formed by the same method as that used to form the EL film 103Rf. The EL film 103Bf can also have the same structure as the EL film 103Rf.

[0342] 7C, a sacrificial film 158Bf and a mask film 159Bf are formed in this order. Then, a resist mask 190B is formed in a position overlapping the conductive layer 152B. The materials and forming methods for the sacrificial film 158Bf and the mask film 159Bf are the same as those applicable to the sacrificial film 158Rf and the mask film 159Rf. The materials and forming methods for the resist mask 190B are the same as those applicable to the resist mask 190R.

[0343] 7D, a resist mask 190B is used to remove a portion of the mask film 159Bf to form a mask layer 159B. The mask layer 159B remains on the conductive layer 152B. The resist mask 190B is then removed. The mask layer 159B is then used as a mask to remove a portion of the sacrificial film 158Bf to form a sacrificial layer 158B. The EL film 103Bf is then processed to form the organic compound layer 103B. For example, the mask layer 159B and the sacrificial layer 158B are used as hard masks to remove a portion of the EL film 103Bf to form the organic compound layer 103B.

[0344] As a result, a laminated structure of the organic compound layer 103B, the sacrificial layer 158B, and the mask layer 159B remains on the conductive layer 152B, and the mask layers 159R and 159G are exposed.

[0345] It is preferable that the side surfaces of the organic compound layers 103R, 103G, and 103B are perpendicular or substantially perpendicular to the surface on which they are formed. For example, it is preferable that the angle formed between the surface on which they are formed and these side surfaces be 60 degrees or more and 90 degrees or less.

[0346] As described above, the distance between adjacent pairs of the organic compound layers 103R, 103G, and 103B formed using photolithography can be narrowed to 8 μm or less, 5 μm or less, 3 μm or less, 2 μm or less, or 1 μm or less. Here, the distance can be defined, for example, as the distance between the opposing ends of adjacent pairs of the organic compound layers 103R, 103G, and 103B. By narrowing the distance between the island-shaped organic compound layers in this manner, a display device with high definition and a large aperture ratio can be provided. Furthermore, the distance between the first electrodes of adjacent light-emitting devices can also be narrowed, for example, to 10 μm or less, 8 μm or less, 5 μm or less, 3 μm or less, 2 μm or less, or 1 μm or less. For example, by using an exposure device for LSIs, the spacing can be narrowed to 500 nm or less, 200 nm or less, 100 nm or less, or even 50 nm or less.

[0347] Subsequently, as shown in FIG. 8A, it is preferable to remove the mask layers 159R, 159G, and 159B.

[0348] The mask layer removal process can be performed using the same method as the mask film processing process. In particular, by using a wet etching method, damage to the organic compound layer 103 during the mask layer removal can be reduced compared to when a dry etching method is used.

[0349] The mask layer may also be removed by dissolving it in a solvent such as water or alcohol, such as ethyl alcohol, methyl alcohol, isopropyl alcohol (IPA), or glycerin.

[0350] After removing the mask layer, a drying treatment may be performed to remove water adsorbed on the surface. For example, a heat treatment can be performed in an inert gas atmosphere or a reduced pressure atmosphere. The heat treatment can be performed at a substrate temperature of 50°C or higher and 200°C or lower, preferably 60°C or higher and 150°C or lower, and more preferably 70°C or higher and 120°C or lower. A reduced pressure atmosphere is preferred because it allows drying at a lower temperature.

[0351] Subsequently, as shown in FIG. 8B, an inorganic insulating film 125f is formed.

[0352] Subsequently, as shown in FIG. 8C, an insulating film 127f, which will later become the insulating layer 127, is formed on the inorganic insulating film 125f.

[0353] The substrate temperature when forming the inorganic insulating film 125f and the insulating film 127f is preferably 60°C or higher, 80°C or higher, 100°C or higher, or 120°C or higher, and 200°C or lower, 180°C or lower, 160°C or lower, 150°C or lower, or 140°C or lower, respectively.

[0354] As the inorganic insulating film 125f, it is preferable to form an insulating film having a thickness of 3 nm or more, 5 nm or more, or 10 nm or more, and 200 nm or less, 150 nm or less, 100 nm or less, or 50 nm or less within the above substrate temperature range.

[0355] The inorganic insulating film 125f is preferably formed by, for example, the ALD method. The ALD method is preferable because it can reduce film formation damage and form a film with high coverage. The inorganic insulating film 125f is preferably formed as an aluminum oxide film by, for example, the ALD method.

[0356] The insulating film 127f is preferably formed by the wet film formation method described above. The insulating film 127f is preferably formed by, for example, spin coating using a photosensitive material, more specifically, using a photosensitive resin composition containing an acrylic resin.

[0357] Subsequently, exposure is performed to expose a portion of the insulating film 127f to visible light or ultraviolet light. The insulating layer 127f is formed in a region sandwiched between any two of the conductive layers 152R, 152G, and 152B, and around the conductive layer 152C.

[0358] The width of the insulating layer 127 to be formed later can be controlled by the exposed region of the insulating film 127f. In this embodiment mode, the insulating layer 127 is processed to have a portion overlapping with the top surface of the conductive layer 151.

[0359] The light used for exposure preferably contains i-line (wavelength 365 nm), and may contain at least one of g-line (wavelength 436 nm) and h-line (wavelength 405 nm).

[0360] Subsequently, as shown in FIG. 9A, development is performed to remove the exposed area of ​​the insulating film 127f, thereby forming an insulating layer 127a.

[0361] 9B , an etching process is performed using the insulating layer 127a as a mask to remove a portion of the inorganic insulating film 125f and thin the film thickness of a portion of the sacrificial layers 158R, 158G, and 158B. This results in the formation of the inorganic insulating layer 125 below the insulating layer 127a. Furthermore, the surfaces of the thin portions of the sacrificial layers 158R, 158G, and 158B are exposed. Hereinafter, the etching process using the insulating layer 127a as a mask may be referred to as the first etching process.

[0362] The first etching treatment can be performed by dry etching or wet etching. Note that it is preferable to form the inorganic insulating film 125f using the same material as the sacrificial layers 158R, 158G, and 158B because the first etching treatment can be performed all at once.

[0363] When dry etching is performed, it is preferable to use a chlorine-based gas. ２ , BCl ３ , SiCl ４ , and CCl ４The chlorine-based gas may be added with oxygen gas, hydrogen gas, helium gas, argon gas, or the like, either alone or in combination of two or more gases. By using dry etching, thin regions of the sacrificial layers 158R, 158G, and 158B can be formed with good in-plane uniformity.

[0364] The dry etching apparatus may be a dry etching apparatus having a high-density plasma source, such as an inductively coupled plasma (ICP) etching apparatus, or a capacitively coupled plasma (CCP) etching apparatus having parallel plate electrodes.

[0365] The first etching treatment is preferably performed by wet etching. By using the wet etching method, damage to the organic compound layer 103R, the organic compound layer 103G, and the organic compound layer 103B can be reduced compared to when using the dry etching method. For example, the wet etching can be performed using an alkaline solution or an acid solution.

[0366] In the first etching process, it is preferable to stop the etching process when the film thicknesses of the sacrificial layers 158R, 158G, and 158B have become thin without completely removing them. In this way, by leaving the corresponding sacrificial layers 158R, 158G, and 158B on the organic compound layers 103R, 103G, and 103B, it is possible to prevent the organic compound layers 103R, 103G, and 103B from being damaged in subsequent processes.

[0367] Subsequently, the entire substrate is exposed to visible light or ultraviolet light, and the insulating layer 127a is preferably irradiated with the energy density of the exposure. ２ Larger, 800 mJ / cm ２ It is preferable that the dose is 0 mJ / cm or less. ２Greater than 500 mJ / cm ２ It is more preferable to perform the following. By performing such exposure after development, the transparency of the insulating layer 127a can be improved in some cases. Furthermore, the substrate temperature required for heat treatment to transform the insulating layer 127a into a tapered shape in a later step can be reduced in some cases.

[0368] Here, the presence of a barrier insulating layer against oxygen (e.g., an aluminum oxide film, etc.) as the sacrificial layer 158R, the sacrificial layer 158G, and the sacrificial layer 158B can reduce the diffusion of oxygen into the organic compound layer 103R, the organic compound layer 103G, and the organic compound layer 103B.

[0369] Next, heat treatment (also referred to as post-baking) is performed. By performing the heat treatment, the insulating layer 127a can be transformed into an insulating layer 127 having tapered side surfaces ( FIG. 9C ). The heat treatment is performed at a temperature lower than the heat resistance temperature of the organic compound layer. The heat treatment can be performed at a substrate temperature of 50° C. to 200° C., preferably 60° C. to 150° C., more preferably 70° C. to 130° C. The heating atmosphere may be an air atmosphere or an inert gas atmosphere. The heating atmosphere may be an atmospheric pressure atmosphere or a reduced-pressure atmosphere. This can improve the adhesion between the insulating layer 127 and the inorganic insulating layer 125 and also improve the corrosion resistance of the insulating layer 127.

[0370] By leaving the sacrificial layers 158R, 158G, and 158B in a thinner state without completely removing them in the first etching treatment, the organic compound layers 103R, 103G, and 103B can be prevented from being damaged and deteriorated in the heat treatment, thereby improving the reliability of the light-emitting device.

[0371] 10A , an etching process is performed using the insulating layer 127 as a mask to remove portions of the sacrificial layers 158R, 158G, and 158B. As a result, openings are formed in the sacrificial layers 158R, 158G, and 158B, respectively, and the top surfaces of the organic compound layers 103R, 103G, 103B, and the conductive layer 152C are exposed. Note that, hereinafter, this etching process may be referred to as a second etching process.

[0372] The end of the inorganic insulating layer 125 is covered with the insulating layer 127. Also, Fig. 10A shows an example in which a part of the end of the sacrificial layer 158G (specifically, the tapered portion formed by the first etching process) is covered with the insulating layer 127, and the tapered portion formed by the second etching process is exposed.

[0373] The second etching process is performed by wet etching. By using the wet etching method, damage to the organic compound layer 103R, the organic compound layer 103G, and the organic compound layer 103B can be reduced compared to when using the dry etching method. The wet etching can be performed using, for example, an alkaline solution or an acidic solution.

[0374] 10B , a second electrode (common electrode) 102 is formed on the organic compound layer 103R, the organic compound layer 103G, the organic compound layer 103B, the conductive layer 152C, and the insulating layer 127. The second electrode (common electrode) 102 can be formed by a method such as sputtering or vacuum deposition.

[0375] 10C, a protective layer 131 is formed on the second electrode (common electrode) 102. The protective layer 131 can be formed by a method such as a vacuum deposition method, a sputtering method, a CVD method, or an ALD method.

[0376] Subsequently, the substrate 120 is attached over the protective layer 131 using the resin layer 122, whereby a display device can be manufactured. As described above, in the method for manufacturing a display device of one embodiment of the present invention, the insulating layer 156 is provided so as to have a region overlapping with a side surface of the conductive layer 151, and the conductive layer 152 is formed so as to cover the conductive layer 151 and the insulating layer 156. This can increase the yield of the display device and suppress the occurrence of defects.

[0377] As described above, in the manufacturing method of the display device according to this embodiment, the island-shaped organic compound layers 103R, 103G, and 103B are formed not using a fine metal mask but by forming a film over the entire surface and then processing it by photolithography. This allows the island-shaped layers to be formed with a uniform thickness. Furthermore, a high-resolution display device or a display device with a high aperture ratio can be realized. Even if the resolution or aperture ratio is high and the distance between subpixels is extremely short, the organic compound layers 103R, 103G, and 103B can be prevented from contacting each other in adjacent subpixels. Therefore, leakage current between subpixels can be suppressed. This prevents crosstalk and realizes a display device with extremely high contrast. Furthermore, a display device with excellent characteristics can be provided, even in a display device having tandem light-emitting devices manufactured using photolithography.

[0378] Embodiment 5 In this embodiment, a display device according to one embodiment of the present invention will be described.

[0379] The display device of the present embodiment can be a high-definition display device, and can therefore be used, for example, as a display unit for a wristwatch-type or bracelet-type information terminal (wearable device), as well as a display unit for a wearable device that can be worn on the head, such as a head-mounted display (HMD) for VR, or a glasses-type device for AR.

[0380] The display device of the present embodiment can be a high-resolution display device or a large-sized display device. Therefore, the display device of the present embodiment can be used in electronic devices having relatively large screens, such as television devices, desktop or notebook personal computers, computer monitors, digital signage, and large game machines such as pachinko machines, as well as in the display units of digital cameras, digital video cameras, digital photo frames, mobile phones, portable game machines, personal digital assistants, and sound reproducing devices.

[0381] 11A shows a perspective view of a display module 280. The display module 280 includes a display device 100A and an FPC 290. Note that the display device included in the display module 280 is not limited to the display device 100A, and may be any of the display devices 100B to 100E described below.

[0382] The display module 280 has a substrate 291 and a substrate 292. The display module 280 has a display portion 281. The display portion 281 is a region that displays an image in the display module 280, and is a region where light from each pixel provided in a pixel portion 284 (described later) can be viewed.

[0383] 11B is a perspective view schematically showing the configuration on the substrate 291 side. A circuit portion 282, a pixel circuit portion 283 on the circuit portion 282, and a pixel portion 284 on the pixel circuit portion 283 are stacked on the substrate 291. A terminal portion 285 for connecting to the FPC 290 is provided in a portion of the substrate 291 that does not overlap with the pixel portion 284. The terminal portion 285 and the circuit portion 282 are electrically connected by a wiring portion 286 composed of a plurality of wirings.

[0384] The pixel portion 284 has a plurality of periodically arranged pixels 284a. An enlarged view of one pixel 284a is shown on the right side of Fig. 11B. The various structures described in the above embodiments can be applied to the pixel 284a.

[0385] The pixel circuit section 283 has a plurality of pixel circuits 283a arranged periodically.

[0386] One pixel circuit 283a is a circuit that controls the driving of a plurality of elements included in one pixel 284a.

[0387] The circuit portion 282 includes a circuit for driving each pixel circuit 283 a of the pixel circuit portion 283. For example, the circuit portion 282 preferably includes one or both of a gate line driver circuit and a source line driver circuit. In addition, the circuit portion 282 may include at least one of an arithmetic circuit, a memory circuit, a power supply circuit, and the like.

[0388] The FPC 290 functions as wiring for supplying a video signal, a power supply potential, or the like from the outside to the circuit portion 282. An IC may be mounted on the FPC 290.

[0389] The display module 280 can be configured such that one or both of the pixel circuit unit 283 and the circuit unit 282 are stacked below the pixel unit 284, thereby making it possible to extremely increase the aperture ratio (effective display area ratio) of the display unit 281.

[0390] Because such a display module 280 has extremely high resolution, it can be suitably used in VR devices such as HMDs or eyeglass-type AR devices. For example, even in a configuration in which the display unit of the display module 280 is viewed through lenses, the display module 280 has an extremely high-resolution display unit 281, so that even if the display unit is enlarged with the lens, the pixels are not visible, allowing for a highly immersive display. Furthermore, the display module 280 is not limited to this, and can be suitably used in electronic devices having relatively small display units.

[0391] Display Device 100A The display device 100A shown in FIG. 12A includes a substrate 301, a light-emitting device 130R, a light-emitting device 130G, a light-emitting device 130B, a capacitor 240, and a transistor 310.

[0392] The substrate 301 corresponds to the substrate 291 in FIGS. 11A and 11B . The transistor 310 is a transistor having a channel formation region in the substrate 301. The substrate 301 can be, for example, a semiconductor substrate such as a single crystal silicon substrate. The transistor 310 includes a part of the substrate 301, a conductive layer 311, a low-resistance region 312, an insulating layer 313, and an insulating layer 314. The conductive layer 311 functions as a gate electrode. The insulating layer 313 is located between the substrate 301 and the conductive layer 311 and functions as a gate insulating layer. The low-resistance region 312 is a region in which the substrate 301 is doped with impurities and functions as a source or drain. The insulating layer 314 is provided to cover a side surface of the conductive layer 311.

[0393] An element isolation layer 315 is provided between two adjacent transistors 310 so as to be embedded in the substrate 301 .

[0394] In addition, an insulating layer 261 is provided to cover the transistor 310 , and a capacitor 240 is provided over the insulating layer 261 .

[0395] The capacitor 240 has a conductive layer 241, a conductive layer 245, and an insulating layer 243 located therebetween. The conductive layer 241 functions as one electrode of the capacitor 240, the conductive layer 245 functions as the other electrode of the capacitor 240, and the insulating layer 243 functions as a dielectric of the capacitor 240.

[0396] The conductive layer 241 is provided over the insulating layer 261 and is buried in the insulating layer 254. The conductive layer 241 is electrically connected to one of the source and the drain of the transistor 310 by a plug 271 buried in the insulating layer 261. The insulating layer 243 is provided to cover the conductive layer 241. The conductive layer 245 is provided in a region overlapping with the conductive layer 241 with the insulating layer 243 interposed therebetween.

[0397] An insulating layer 255 is provided to cover the capacitor 240, an insulating layer 174 is provided on the insulating layer 255, and an insulating layer 175 is provided on the insulating layer 174. Light-emitting device 130R, light-emitting device 130G, and light-emitting device 130B are provided on the insulating layer 175. An insulator is provided in the region between adjacent light-emitting devices.

[0398] An insulating layer 156R is provided to have a region overlapping with a side surface of the conductive layer 151R, an insulating layer 156G is provided to have a region overlapping with a side surface of the conductive layer 151G, and an insulating layer 156B is provided to have a region overlapping with a side surface of the conductive layer 151B. Furthermore, a conductive layer 152R is provided to cover the conductive layer 151R and the insulating layer 156R, a conductive layer 152G is provided to cover the conductive layer 151G and the insulating layer 156G, and a conductive layer 152B is provided to cover the conductive layer 151B and the insulating layer 156B. A sacrificial layer 158R is located on the organic compound layer 103R, a sacrificial layer 158G is located on the organic compound layer 103G, and a sacrificial layer 158B is located on the organic compound layer 103B.

[0399] The conductive layer 151R, the conductive layer 151G, and the conductive layer 151B are electrically connected to one of the source and the drain of the transistor 310 by an insulating layer 243, an insulating layer 255, an insulating layer 174, a plug 256 embedded in the insulating layer 175, a conductive layer 241 embedded in the insulating layer 254, and a plug 271 embedded in the insulating layer 261. Various conductive materials can be used for the plugs.

[0400] Furthermore, a protective layer 131 is provided on the light-emitting devices 130R, 130G, and 130B. A substrate 120 is bonded to the protective layer 131 via a resin layer 122. For details of the components from the light-emitting device 130 to the substrate 120, refer to the fourth embodiment. The substrate 120 corresponds to the substrate 292 in FIG. 11A .

[0401] Fig. 12B is a modified example of the display device 100A shown in Fig. 12A. The display device shown in Fig. 12B has a colored layer 132R, a colored layer 132G, and a colored layer 132B, and the light-emitting device 130 has an area where it overlaps with one of the colored layers 132R, 132G, and 132B. In the display device shown in Fig. 12B, the light-emitting device 130 can emit, for example, white light. Furthermore, for example, the colored layer 132R can transmit red light, the colored layer 132G can transmit green light, and the colored layer 132B can transmit blue light.

[0402] [Display Device 100B] FIG. 13 shows a perspective view of the display device 100B, and FIG. 14 shows a cross-sectional view of the display device 100C.

[0403] The display device 100B has a configuration in which a substrate 352 and a substrate 351 are bonded together. In Fig. 13, the substrate 352 is indicated by a dashed line.

[0404] The display device 100B includes a pixel portion 177, a connection portion 140, a circuit 356, wiring 355, and the like. Fig. 13 shows an example in which an IC 354 and an FPC 353 are mounted on the display device 100B. Therefore, the configuration shown in Fig. 13 can also be called a display module including the display device 100B, an IC (integrated circuit), and an FPC. Here, a display device in which a connector such as an FPC is attached to a substrate or a display device in which an IC is mounted on the substrate is called a display module.

[0405] The connection portion 140 is provided outside the pixel portion 177. There may be one or more connection portions 140. The connection portion 140 electrically connects the common electrode of the light-emitting device and the conductive layer, and can supply a potential to the common electrode.

[0406] The circuit 356 can be, for example, a scanning line driver circuit.

[0407] The wiring 355 has a function of supplying signals and power to the pixel portion 177 and the circuit 356. The signals and power are input to the wiring 355 from the outside via the FPC 353 or from the IC 354.

[0408] 13 shows an example in which an IC 354 is provided on a substrate 351 by a chip-on-glass (COG) method, a chip-on-film (COF) method, or the like. For example, an IC having a scanning line driver circuit or a signal line driver circuit can be used as the IC 354. Note that the display device 100B and the display module may not include an IC. Alternatively, the IC may be mounted on an FPC by a COF method, for example.

[0409] Figure 14 shows an example of a cross section of the display device 100B in Figure 13, in which a portion of the region including the FPC 353, a portion of the circuit 356, a portion of the pixel portion 177, a portion of the connection portion 140, and a portion of the region including the end portion are cut away, as display device 100C.

[0410] [Display Device 100C] The display device 100C shown in FIG. 14 has, between a substrate 351 and a substrate 352, a transistor 201, a transistor 205, a light-emitting device 130R that emits red light, a light-emitting device 130G that emits green light, and a light-emitting device 130B that emits blue light, etc.

[0411] For details of the light emitting device 130R, the light emitting device 130G, and the light emitting device 130B, refer to the fourth embodiment.

[0412] Light-emitting device 130R has conductive layer 224R, conductive layer 151R on conductive layer 224R, and conductive layer 152R on conductive layer 151R. Light-emitting device 130G has conductive layer 224G, conductive layer 151G on conductive layer 224G, and conductive layer 152G on conductive layer 151G. Light-emitting device 130B has conductive layer 224B, conductive layer 151B on conductive layer 224B, and conductive layer 152B on conductive layer 151B.

[0413] The conductive layer 224R is connected to the conductive layer 222b of the transistor 205 through an opening provided in the insulating layer 214. An end of the conductive layer 151R is located outside an end of the conductive layer 224R. An insulating layer 156R is provided to have a region in contact with the side surface of the conductive layer 151R, and a conductive layer 152R is provided to cover the conductive layer 151R and the insulating layer 156R.

[0414] Conductive layer 224G, conductive layer 151G, conductive layer 152G, and insulating layer 156G in light-emitting device 130G, and conductive layer 224B, conductive layer 151B, conductive layer 152B, and insulating layer 156B in light-emitting device 130B are similar to conductive layer 224R, conductive layer 151R, conductive layer 152R, and insulating layer 156R in light-emitting device 130R, and therefore detailed description thereof will be omitted.

[0415] Recesses are formed in the conductive layers 224R, 224G, and 224B so as to cover the openings provided in the insulating layer 214. A layer 128 is buried in the recesses.

[0416] The layer 128 has a function of filling in recesses of the conductive layer 224R, the conductive layer 224G, and the conductive layer 224B and planarizing the surface. Conductive layers 151R, 151G, and 151B, which are electrically connected to the conductive layer 224R, the conductive layer 224G, and the conductive layer 224B, are provided on the conductive layer 224R, the conductive layer 224G, and the conductive layer 224B and the layer 128. Therefore, the regions overlapping with the recesses of the conductive layer 224R, the conductive layer 224G, and the conductive layer 224B can also be used as light-emitting regions, thereby increasing the aperture ratio of the pixel.

[0417] The layer 128 may be an insulating layer or a conductive layer. Various inorganic insulating materials, organic insulating materials, and conductive materials can be used as appropriate for the layer 128. In particular, the layer 128 is preferably formed using an insulating material, and more preferably using an organic insulating material. For example, the organic insulating material that can be used for the insulating layer 127 described above can be used for the layer 128.

[0418] A protective layer 131 is provided on the light-emitting device 130R, the light-emitting device 130G, and the light-emitting device 130B. The protective layer 131 and the substrate 352 are bonded via an adhesive layer 142. A light-shielding layer 157 is provided on the substrate 352. A solid sealing structure, a hollow sealing structure, or the like can be applied to seal the light-emitting device 130. In FIG. 14 , the space between the substrate 352 and the substrate 351 is filled with the adhesive layer 142, and a solid sealing structure is applied. Alternatively, the space may be filled with an inert gas (nitrogen, argon, etc.), and a hollow sealing structure may be applied. In this case, the adhesive layer 142 may be provided so as not to overlap with the light-emitting device. Alternatively, the space may be filled with a resin different from the frame-shaped adhesive layer 142.

[0419] 14 shows an example in which the connection portion 140 has a conductive layer 224C obtained by processing the same conductive film as the conductive layers 224R, 224G, and 224B, a conductive layer 151C obtained by processing the same conductive film as the conductive layers 151R, 151G, and 151B, and a conductive layer 152C obtained by processing the same conductive film as the conductive layers 152R, 152G, and 152B. Also, FIG. 14 shows an example in which an insulating layer 156C is provided so as to have a region overlapping with a side surface of the conductive layer 151C.

[0420] The display device 100C is a top-emission type. Light emitted from the light-emitting device is emitted toward the substrate 352. The substrate 352 is preferably made of a material that is highly transparent to visible light. The pixel electrode contains a material that reflects visible light, and the counter electrode (common electrode) contains a material that transmits visible light.

[0421] An insulating layer 211, an insulating layer 213, an insulating layer 215, and an insulating layer 214 are provided over the substrate 351 in this order. A part of the insulating layer 211 functions as a gate insulating layer for each transistor. A part of the insulating layer 213 functions as a gate insulating layer for each transistor. The insulating layer 215 is provided to cover the transistor. The insulating layer 214 is provided to cover the transistor and functions as a planarization layer. Note that the number of gate insulating layers and the number of insulating layers covering the transistors are not limited, and each may be a single layer or two or more layers.

[0422] The insulating layers 211, 213, and 215 are each preferably formed using an inorganic insulating film.

[0423] The insulating layer 214 that functions as a planarizing layer is preferably an organic insulating layer.

[0424] The transistor 201 and the transistor 205 each include a conductive layer 221 functioning as a gate, an insulating layer 211 functioning as a gate insulating layer, a conductive layer 222a and a conductive layer 222b functioning as a source and a drain, a semiconductor layer 231, an insulating layer 213 functioning as a gate insulating layer, and a conductive layer 223 functioning as a gate.

[0425] A connection portion 204 is provided in a region of the substrate 351 where the substrate 352 does not overlap. In the connection portion 204, a source electrode or a drain electrode of the transistor 201 is electrically connected to the FPC 353 through a conductive layer 166 and a connection layer 242. The conductive layer 166 has an example of a stacked structure including a conductive film obtained by processing the same conductive film as the conductive layers 224R, 224G, and 224B, a conductive film obtained by processing the same conductive film as the conductive layers 151R, 151G, and 151B, and a conductive film obtained by processing the same conductive film as the conductive layers 152R, 152G, and 152B. The conductive layer 166 is exposed on the top surface of the connection portion 204. This allows the connection portion 204 and the FPC 353 to be electrically connected via the connection layer 242.

[0426] It is preferable to provide a light-shielding layer 157 on the surface of the substrate 352 facing the substrate 351. The light-shielding layer 157 can be provided between adjacent light-emitting devices, on the connection section 140, on the circuit 356, etc. In addition, various optical members can be arranged on the outside of the substrate 352.

[0427] The substrate 351 and the substrate 352 can be made of the same material as can be used for the substrate 120 .

[0428] The adhesive layer 142 can be made of a material that can be used for the resin layer 122 .

[0429] The connection layer 242 may be an anisotropic conductive film (ACF), an anisotropic conductive paste (ACP), or the like.

[0430] [Display Device 100D] The display device 100D shown in FIG. 15 differs from the display device 100C shown in FIG. 14 mainly in that it is a bottom-emission display device.

[0431] Light emitted from the light-emitting device is emitted toward the substrate 351. A material that is highly transparent to visible light is preferably used for the substrate 351. On the other hand, the light-transmitting property of the material used for the substrate 352 does not matter.

[0432] A light-shielding layer 317 is preferably formed between the substrate 351 and the transistor 201 and between the substrate 351 and the transistor 205. In the example shown in FIG. 15, the light-shielding layer 317 is provided over the substrate 351, the insulating layer 153 is provided over the light-shielding layer 317, and the transistors 201, 205, and the like are provided over the insulating layer 153.

[0433] Light emitting device 130R includes conductive layer 112R, conductive layer 126R on conductive layer 112R, and conductive layer 129R on conductive layer 126R.

[0434] Light emitting device 130B includes conductive layer 112B, conductive layer 126B on conductive layer 112B, and conductive layer 129B on conductive layer 126B.

[0435] The conductive layers 112R, 112B, 126R, 126B, 129R, and 129B are each formed using a material that is highly transparent to visible light. The second electrode 102 is preferably formed using a material that reflects visible light.

[0436] Although the light emitting device 130G is not shown in FIG. 15, the light emitting device 130G is also provided.

[0437] Although FIG. 15 and other figures show an example in which the top surface of the layer 128 has a flat portion, the shape of the layer 128 is not particularly limited.

[0438] [Display Device 100D2] The display device 100D2 shown in Fig. 16 is an example of a bottom-emission type display device that differs from the display device 100D shown in Fig. 15. The display device 100D2 differs from the display device 100D in that it has an organic resin layer 180. Note that in the figure, the reference numerals of the same components as those in Fig. 15 may be omitted, and the description in Fig. 15 may be referred to for details.

[0439] 16B shows a top view layout of a pixel 178 (pixel 178a and pixel 178b) having subpixels 110 (subpixels 110R, 110G, 110B, and 110W), and Fig. 16C shows a top view of the organic resin layer 180 in the region where the subpixels 110R and 110W of the pixel 178 are formed. Note that the distance between the light-shielding layers 317 is 110Rw in the light-emitting region of the subpixel 110R.

[0440] As shown in FIG. 16A , organic resin layer 180 is provided on insulating layer 214. As shown in the region surrounded by the dashed dotted line in FIG. 16A and in FIG. 16C , organic resin layer 180 has curved recesses 181 (recesses 181 a and 181 b) at least in the region where the subpixels are formed. Note that recesses 181 may be provided outside the light-emitting region, such as recess 181 c. Providing recess 181 c refracts light emitted in the region overlapping with light-shielding layer 317 or light traveling to the region overlapping with light-shielding layer 317, allowing it to be extracted from the light-emitting region, thereby improving light-emitting efficiency.

[0441] A plurality of recesses 181 may be formed in a matrix. Recesses 181a and 181b may be provided in contact with each other, or may have a flat surface therebetween.

[0442] 16, the recess has a hexagonal top surface shape (FIG. 16C) and a semicircular cross-sectional shape (FIG. 16A), but may have other shapes as needed. For example, the recess may have a polygonal top surface shape such as a triangle, a quadrangle (including a rectangle and a square), a pentagon, or any other polygon with rounded corners, an ellipse, or a circle.

[0443] An insulating layer containing an organic material can be used as the organic resin layer 180. For example, acrylic resin, polyimide resin, epoxy resin, imide resin, polyamide resin, polyimideamide resin, silicone resin, siloxane resin, benzocyclobutene resin, phenolic resin, precursors of these resins, etc. can be used as the organic resin layer 180. Alternatively, organic materials such as polyvinyl alcohol (PVA), polyvinyl butyral, polyvinylpyrrolidone, polyethylene glycol, polyglycerin, pullulan, water-soluble cellulose, or alcohol-soluble polyamide resin can be used as the organic resin layer 180.

[0444] Furthermore, a photosensitive resin can be used as the organic resin layer 180. A photoresist can be used as the photosensitive resin. The photosensitive resin can be a positive-type material or a negative-type material.

[0445] The organic resin layer 180 may contain a material that absorbs visible light. For example, the organic resin layer 180 itself may be made of a material that absorbs visible light, or the organic resin layer 180 may contain a pigment that absorbs visible light. For example, the organic resin layer 180 may be made of a resin that can be used as a color filter that transmits red, blue, or green light and absorbs other light, or a resin that contains carbon black as a pigment and functions as a black matrix.

[0446] In addition, the first electrode 101 (the first electrode 101R and the first electrode 101W) is provided on the organic resin layer 180, and the organic compound layer 103 is provided on the first electrode 101. Ends of the first electrode 101 and the organic compound layer 103 may be covered with an insulating layer 127.

[0447] Furthermore, the first electrode 101 formed on the organic resin layer 180 has a recess similar to the recess of the organic resin layer 180. Furthermore, the organic compound layer 103 formed on the first electrode 101 has a recess similar to the recess of the first electrode 101. Furthermore, the common layer 104 formed on the organic compound layer 103 has a recess similar to the recess of the organic compound layer 103. Furthermore, the second electrode 102 formed on the common layer 104 has a recess similar to the recess of the common layer 104. That is, the recesses of the organic resin layer 180, the first electrode 101, the organic compound layer 103, the common layer 104, and the second electrode 102 have a structure in which they overlap one another.

[0448] In addition, a common layer 104 is provided over the organic compound layer 103 and the insulating layer 127, and a second electrode 102 is provided over the common layer 104. A protective layer 131 is provided over the second electrode 102, and the second electrode 102 is bonded to a substrate 352 via an adhesive layer 142.

[0449] Although the light emitting device 130G and the light emitting device 130B are not shown in FIG. 16, the light emitting device 130G and the light emitting device 130B are also provided.

[0450] The above-described light-emitting device according to one embodiment of the present invention can provide an organic semiconductor device with high emission efficiency, and therefore, an organic semiconductor device with high reliability, low driving voltage, and low power consumption can be provided.

[0451] [Display Device 100E] The display device 100E shown in FIG. 17 is a modified example of the display device 100C shown in FIG. 14, and differs from the display device 100C mainly in that it has colored layers 132R, 132G, and 132B.

[0452] In the display device 100E, the light-emitting device 130 has an area that overlaps one of the colored layers 132R, 132G, and 132B. The colored layers 132R, 132G, and 132B can be provided on the surface of the substrate 352 facing the substrate 351. An end of the colored layer 132R, an end of the colored layer 132G, and an end of the colored layer 132B can overlap the light-shielding layer 157.

[0453] In the display device 100E, the light-emitting device 130 can emit, for example, white light. Furthermore, for example, the colored layer 132R can transmit red light, the colored layer 132G can transmit green light, and the colored layer 132B can transmit blue light. The display device 100E may be configured such that the colored layers 132R, 132G, and 132B are provided between the protective layer 131 and the adhesive layer 142.

[0454] [Display Device 100E2] The display device 100E2 shown in Fig. 18 is a modified example of the display device 100E shown in Fig. 17, and has microlenses 182 on the colored layers 132R, 132G, and 132B. Note that in the figure, the reference numerals of the same components as those in Fig. 17 may be omitted, and for details, the description in Fig. 17 may be referred to.

[0455] 18B shows a top view layout of a pixel 178 (pixel 178a and pixel 178b) having subpixels 110 (subpixels 110R, 110G, and 110B), and Fig. 18C shows a top view of a microlens 182 in a region where the subpixels 110R and 110G of the pixel 178 are formed. Note that the region where the common electrode and the organic compound layer 103 are in contact has a width 110Gw in the light-emitting region of the subpixel 110G.

[0456] 18A includes a planarization film 143 on a protective layer 131, and colored layers 132R, 132G, and 132B on the planarization film 143. A planarization film 144 is provided so as to cover the colored layers 132R, 132G, and 132B. A microlens 182 is provided on the planarization film 144.

[0457] As shown in FIG. 18C, the microlens 182 may be provided for each sub-pixel in the region where the sub-pixels are formed.

[0458] 18C, the top surface shape of the microlens 182 is shown as a hexagon, but other shapes may be used as needed. For example, the top surface shape of the recess may be a polygon such as a triangle, a quadrangle (including a rectangle and a square), a pentagon, or a polygon with rounded corners, an ellipse, or a circle.

[0459] The microlenses 182 can be formed using the same material as the organic resin layer 180 .

[0460] The light-emitting device of one embodiment of the present invention having the above-described microlens 182 includes a cap layer as described in Embodiment 1. Therefore, an organic semiconductor device with high light-emitting efficiency can be provided due to the effect of the microlens 182 and the effect of the organic semiconductor device using the cap layer being inseparable as an integrated unit. Therefore, an organic semiconductor device with good reliability, low driving voltage, and low power consumption that is optimal for a display for mobile applications can be provided.

[0461] This embodiment mode can be combined with other embodiment modes or examples as appropriate. In addition, in this specification, when a plurality of configuration examples are shown in one embodiment mode, the configuration examples can be combined as appropriate.

[0462] Embodiment 6 In this embodiment, an electronic device according to one embodiment of the present invention will be described.

[0463] The electronic devices of this embodiment include the display device of one embodiment of the present invention in a display portion. The display device of one embodiment of the present invention has low power consumption and high reliability. Therefore, the display device of one embodiment of the present invention can be used in the display portion of various electronic devices.

[0464] Examples of electronic devices include electronic devices with relatively large screens such as television sets, desktop or notebook personal computers, computer monitors, digital signage, large game machines such as pachinko machines, as well as digital cameras, digital video cameras, digital photo frames, mobile phones, portable game machines, personal digital assistants, and sound playback devices.

[0465] An example of a wearable device that can be worn on the head will be described with reference to FIGS. 19A to 19D.

[0466] The electronic device 700A shown in FIG. 19A and the electronic device 700B shown in FIG. 19B each have a pair of display panels 751, a pair of housings 721, a communication unit (not shown), a pair of mounting units 723, a control unit (not shown), an imaging unit (not shown), a pair of optical members 753, a frame 757, and a pair of nose pads 758.

[0467] The display device of one embodiment of the present invention can be applied to the display panel 751. Therefore, the electronic device can be highly reliable.

[0468] Each of the electronic device 700A and the electronic device 700B can project an image displayed on the display panel 751 onto a display area 756 of the optical member 753. Because the optical member 753 is translucent, the user can see the image displayed in the display area superimposed on a transmitted image visible through the optical member 753.

[0469] The electronic device 700A and the electronic device 700B may be provided with a camera capable of capturing an image in front of them as an imaging unit. Furthermore, the electronic device 700A and the electronic device 700B may each be provided with an acceleration sensor such as a gyro sensor, thereby detecting the orientation of the user's head and displaying an image corresponding to that orientation in the display area 756.

[0470] The communication unit has a wireless communication device, and can supply, for example, a video signal via the wireless communication device. Note that instead of or in addition to the wireless communication device, a connector to which a cable through which a video signal and a power supply potential can be connected may be provided.

[0471] Furthermore, the electronic device 700A and the electronic device 700B are provided with batteries, which can be charged wirelessly and / or wired.

[0472] The housing 721 may be provided with a touch sensor module.

[0473] Various touch sensors can be used as the touch sensor module. For example, various types of touch sensors can be used, such as a capacitance type, a resistive film type, an infrared type, an electromagnetic induction type, a surface acoustic wave type, or an optical type. In particular, it is preferable to use a capacitance type or an optical type sensor in the touch sensor module.

[0474] The electronic device 800A shown in Figure 19C and the electronic device 800B shown in Figure 19D each have a pair of display units 820, a housing 821, a communication unit 822, a pair of mounting units 823, a control unit 824, a pair of imaging units 825, and a pair of lenses 832.

[0475] The display device of one embodiment of the present invention can be applied to the display portion 820. Therefore, the electronic device can have high reliability.

[0476] The display unit 820 is provided inside the housing 821 at a position that can be viewed through the lens 832. In addition, by displaying different images on the pair of display units 820, it is possible to perform three-dimensional display using parallax.

[0477] It is preferable that electronic device 800A and electronic device 800B each have a mechanism that allows the left and right positions of lens 832 and display unit 820 to be adjusted so that they are optimally positioned according to the position of the user's eyes.

[0478] The mounting portion 823 allows the user to mount the electronic device 800A or the electronic device 800B on the head.

[0479] The imaging unit 825 has a function of acquiring external information. Data acquired by the imaging unit 825 can be output to the display unit 820. An image sensor can be used for the imaging unit 825. Furthermore, multiple cameras may be provided to support multiple angles of view, such as telephoto and wide-angle.

[0480] The electronic device 800A may have a vibration mechanism that functions as a bone conduction earphone.

[0481] The electronic device 800A and the electronic device 800B may each have an input terminal to which a cable can be connected for supplying a video signal from a video output device or the like and power for charging a battery provided in the electronic device.

[0482] The electronic device of one embodiment of the present invention may have a function of wirelessly communicating with the earphone 750 .

[0483] 19B includes earphone unit 727. A portion of the wiring connecting earphone unit 727 and the control unit may be disposed inside housing 721 or attachment unit 723.

[0484] 19D includes an earphone unit 827. For example, the earphone unit 827 and the control unit 824 may be configured to be connected to each other by wire.

[0485] As described above, as electronic devices according to one embodiment of the present invention, both glasses-type devices (such as the electronic devices 700A and 700B) and goggle-type devices (such as the electronic devices 800A and 800B) are suitable.

[0486] The electronic device 6500 shown in FIG. 20A is a portable information terminal that can be used as a smartphone.

[0487] The electronic device 6500 includes a housing 6501, a display portion 6502, a power button 6503, a button 6504, a speaker 6505, a microphone 6506, a camera 6507, a light source 6508, and the like. The display portion 6502 has a touch panel function.

[0488] The display device of one embodiment of the present invention can be applied to the display portion 6502. Therefore, the electronic device can have high reliability.

[0489] FIG. 20B is a schematic cross-sectional view including the end of the housing 6501 on the microphone 6506 side.

[0490] A light-transmitting protective member 6510 is provided on the display surface side of the housing 6501, and a display panel 6511, an optical member 6512, a touch sensor panel 6513, a printed circuit board 6517, a battery 6518, etc. are arranged in the space surrounded by the housing 6501 and the protective member 6510.

[0491] A display panel 6511, an optical member 6512, and a touch sensor panel 6513 are fixed to the protective member 6510 by adhesive layers (not shown).

[0492] In a region outside the display portion 6502, a part of the display panel 6511 is folded back, and an FPC 6515 is connected to the folded back part. An IC 6516 is mounted on the FPC 6515. The FPC 6515 is connected to a terminal provided on a printed circuit board 6517.

[0493] The display device of one embodiment of the present invention can be applied to the display panel 6511. Therefore, an extremely lightweight electronic device can be realized. Furthermore, since the display panel 6511 is extremely thin, a large-capacity battery 6518 can be mounted thereon while keeping the thickness of the electronic device small. Furthermore, by folding back a part of the display panel 6511 and arranging a connection portion with the FPC 6515 on the back side of the pixel portion, an electronic device with a narrow frame can be realized.

[0494] 20C shows an example of a television set. A television set 7100 has a display portion 7000 built into a housing 7171. Here, the housing 7171 is supported by a stand 7173.

[0495] The display device of one embodiment of the present invention can be applied to the display portion 7000. Therefore, the electronic device can have high reliability.

[0496] The television set 7100 shown in FIG. 20C can be operated using operation switches provided on the housing 7171 and a separate remote control 7151.

[0497] 20D shows an example of a laptop personal computer 7200. The laptop personal computer 7200 includes a housing 7211, a keyboard 7212, a pointing device 7213, and an external connection port 7214. The housing 7211 includes a display portion 7000.

[0498] The display device of one embodiment of the present invention can be applied to the display portion 7000. Therefore, the electronic device can have high reliability.

[0499] 20E and 20F show an example of digital signage.

[0500] 20E includes a housing 7301, a display portion 7000, and a speaker 7303. The digital signage 7300 may further include an LED lamp, operation keys (including a power switch or an operation switch), a connection terminal, various sensors, a microphone, and the like.

[0501] 20F shows a digital signage 7400 attached to a cylindrical pillar 7401. The digital signage 7400 has a display unit 7000 provided along the curved surface of the pillar 7401.

[0502] 20E and 20F, the display device of one embodiment of the present invention can be applied to the display portion 7000. Therefore, the electronic device can have high reliability.

[0503] The larger the display unit 7000, the more information can be provided at one time. Also, the larger the display unit 7000, the more easily it will attract people's attention, which can increase the advertising effectiveness of, for example, advertisements.

[0504] Furthermore, as shown in Figures 20E and 20F, it is preferable that the digital signage 7300 or the digital signage 7400 be able to wirelessly link with an information terminal 7311 or an information terminal 7411 such as a smartphone carried by a user.

[0505] The electronic device shown in Figures 21A to 21G has a housing 9000, a display unit 9001, a speaker 9003, operation keys 9005 (including a power switch or an operation switch), a connection terminal 9006, a sensor 9007 (including a function to measure force, displacement, position, speed, acceleration, angular velocity, rotation speed, distance, light, liquid, magnetism, temperature, chemical substance, sound, time, hardness, electric field, current, voltage, power, radiation, flow rate, humidity, gradient, vibration, odor or infrared rays), a microphone 9008, etc.

[0506] 21A to 21G have various functions, such as a function to display various information (still images, videos, text images, etc.) on a display unit, a touch panel function, a function to display a calendar, date, time, etc., a function to control processing using various software (programs), a wireless communication function, a function to read and process programs or data recorded on a recording medium, etc.

[0507] The electronic devices shown in FIGS. 21A to 21G will be described in detail below.

[0508] FIG. 21A is a perspective view showing a mobile information terminal 9171. The mobile information terminal 9171 can be used as, for example, a smartphone. Note that the mobile information terminal 9171 may be provided with a speaker 9003, a connection terminal 9006, a sensor 9007, or the like. The mobile information terminal 9171 can display text and image information on multiple surfaces. FIG. 21A shows an example in which three icons 9050 are displayed. Information 9051, indicated by a dashed rectangle, can also be displayed on another surface of the display unit 9001. Examples of the information 9051 include notifications of incoming emails, SNS messages, phone calls, etc., the title of the email or SNS message, the sender's name, the date and time, the remaining battery level, and radio wave intensity. Alternatively, the icon 9050 or the like may be displayed in the position where the information 9051 is displayed.

[0509] 21B is a perspective view showing a mobile information terminal 9172. The mobile information terminal 9172 has a function of displaying information on three or more surfaces of the display portion 9001. Here, an example is shown in which information 9052, information 9053, and information 9054 are displayed on different surfaces. For example, a user can check information 9053 displayed in a position that can be observed from above the mobile information terminal 9172 while the mobile information terminal 9172 is stored in a breast pocket of clothes.

[0510] 21C is a perspective view showing a tablet terminal 9173. The tablet terminal 9173 is capable of executing various applications such as mobile phone calls, e-mail, text browsing and creation, music playback, internet communication, and computer games, for example. The tablet terminal 9173 has a display unit 9001, a camera 9002, a microphone 9008, and a speaker 9003 on the front side of a housing 9000, operation keys 9005 as operation buttons on the left side of the housing 9000, and a connection terminal 9006 on the bottom.

[0511] FIG. 21D is a perspective view showing a wristwatch-type mobile information terminal 9200. The mobile information terminal 9200 can be used as, for example, a smart watch (registered trademark). The display surface of the display unit 9001 is curved, and display can be performed along the curved display surface. The mobile information terminal 9200 can also perform hands-free calling by communicating with, for example, a wirelessly capable headset. The mobile information terminal 9200 can also perform data transmission and charging with another information terminal through a connection terminal 9006. Note that charging may be performed by wireless power supply.

[0512] 21E to 21G are perspective views showing a foldable mobile information terminal 9201. Also, FIG. 21E is a perspective view of the mobile information terminal 9201 in an unfolded state, FIG. 21G is a perspective view of the mobile information terminal 9201 in a folded state, and FIG. 21F is a perspective view of a state in the process of changing from one of FIG. 21E and FIG. 21G to the other. The mobile information terminal 9201 is highly portable when folded, and has a seamless, wide display area when unfolded, providing excellent visibility of the display. The display portion 9001 of the mobile information terminal 9201 is supported by three housings 9000 connected by hinges 9055. For example, the display portion 9001 can be bent with a curvature radius of 0.1 mm or more and 150 mm or less.

[0513] This embodiment mode can be combined with other embodiment modes or examples as appropriate. In addition, in this specification, when a plurality of configuration examples are shown in one embodiment mode, the configuration examples can be combined as appropriate.

[0514] In this example, the manufacturing methods and characteristics of light-emitting devices 1-1, 1-2, and 1-3, which are light-emitting devices according to one embodiment of the present invention, and a comparative light-emitting device, a comparative light-emitting device, will be described in detail. The structural formulae of main compounds used in the light-emitting devices 1-1, 1-2, and 1-3 and the comparative light-emitting device 1 are shown below.

[0515]

[0516] (Method of manufacturing light-emitting device 1-1) First, silver (Ag) was formed as a reflective electrode on a glass substrate from the substrate side by sputtering to a film thickness of 100 nm, and indium tin oxide containing silicon oxide (ITSO) was then laminated as a transparent electrode by sputtering to a film thickness of 10 nm, thereby forming a first electrode 101 measuring 2 mm x 2 mm. The transparent electrode functions as an anode and is considered to be the first electrode 101 together with the reflective electrode.

[0517] Next, as a pretreatment for forming a light-emitting device on the substrate, the surface of the substrate was washed with water and baked at 200° C. for 1 hour.

[0518] After that, about 1 × 10 −４The substrate was introduced into a vacuum deposition apparatus whose interior had been reduced in pressure to 100 Pa, and vacuum-baked at 170° C. for 60 minutes in a heating chamber within the vacuum deposition apparatus, after which the substrate was allowed to cool for approximately 30 minutes.

[0519] Next, the substrate was fixed to a holder provided in a vacuum deposition apparatus so that the surface on which the first electrode 101 was formed faced downward. N-(biphenyl-4-yl)-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-9,9-dimethyl-9H-fluoren-2-amine (abbreviation: PCBBiF) represented by the above structural formula (i) and an electron acceptor material (OCHD-003) containing fluorine and having a molecular weight of 672 were co-deposited by a deposition method on the inorganic insulating film and the first electrode 101 at a weight ratio of 1:0.03 (= PCBBiF:OCHD-003) to a film thickness of 10 nm, thereby forming a hole injection layer 111.

[0520] On the hole injection layer 111, PCBBiF was evaporated to a thickness of 100 nm to form a first hole transport layer, and then N,N-bis[4-(dibenzofuran-4-yl)phenyl]-4-amino-p-terphenyl (abbreviation: DBfBB1TP) represented by the above structural formula (ii) was evaporated to a thickness of 10 nm to form a second hole transport layer, thereby forming the hole transport layer 112.

[0521] Subsequently, on the hole-transport layer 112, 9-(1-naphthyl)-10-[4-(2-naphthyl)phenyl]anthracene (abbreviation: αN-βNPAnth) represented by the above structural formula (iii) and N,N'-diphenyl-N,N'-bis(9-phenyl-9H-carbazol-2-yl)naphtho[2,3-b;6,7-b']bisbenzofuran-3,10-diamine (abbreviation: 3,10PCA2Nbf(IV)-02) represented by the above structural formula (iv) were co-deposited at a weight ratio of 1:0.015 (=αN-βNPAnth:3,10PCA2Nbf(IV)-02) to a film thickness of 25 nm, to form a light-emitting layer 113.

[0522] Thereafter, 2-{3-[3-(N-phenyl-9H-carbazol-3-yl)-9H-carbazol-9-yl]phenyl}dibenzo[f,h]quinoxaline (abbreviation: 2mPCCzPDBq) represented by the above structural formula (v) was evaporated to a film thickness of 15 nm, and subsequently 2,2′-(1,3-phenylene)bis(9-phenyl-1,10-phenanthroline) (abbreviation: mPPhen2P) represented by the above structural formula (vi) was evaporated to a film thickness of 10 nm, thereby forming an electron transport layer 114.

[0523] Next, lithium fluoride (LiF) was evaporated to a thickness of 1 nm to form an electron injection layer 115, and then silver (Ag) and magnesium (Mg) were co-evaporated at a volume ratio of 1:0.1 to a thickness of 15 nm to form a second electrode 102.

[0524] Thereafter, 2-(3",5',5"-tri-t-butyl-[1,1':3',1"-terphenyl]-5-yl)-4,6-diphenyl-1,3,5-triazine (abbreviation: mmtBumTPTzn-03) represented by the structural formula (vii) above was evaporated on the second electrode 102 to a thickness of 12.5 nm to form a first layer 188. Furthermore, DBfBB1TP was evaporated on the first layer 188 to a thickness of 50 nm to form a second layer 189, thereby forming a cap layer 155.

[0525] Next, in a glove box with a nitrogen atmosphere, the light-emitting device was sealed with a glass substrate to prevent it from being exposed to the atmosphere (a UV-curable sealant was applied around the element, UV was irradiated only onto the sealant without irradiating the light-emitting device, and heat treatment was performed at 80°C under atmospheric pressure for 1 hour), thereby forming light-emitting device 1-1.

[0526] (Method for Fabricating Light-Emitting Device 1-2) Light-emitting device 1-2 was fabricated in the same manner as light-emitting device 1-1, except that mmtBumTPTzn-03 in light-emitting device 1-1 was changed to 2-(biphenyl-2-yl)-4-[(3′,5′-di-tert-butyl)biphenyl-3-yl]-6-phenyl-1,3,5-triazine (abbreviation: oBP-mmtBumBPTzn) represented by the above structural formula (viii).

[0527] (Method for producing light-emitting device 1-3) Light-emitting device 1-3 was produced in the same manner as light-emitting device 1-1, except that mmtBumTPTzn-03 in light-emitting device 1-1 was replaced with 2,4-bis(3′,5′-di-tert-butylbiphenyl-3-yl)-6-phenyl-1,3,5-triazine (abbreviation: mmtBumBP2Tzn) represented by the above structural formula (ix).

[0528] (Method for Fabricating Comparative Light-Emitting Device 1) Comparative light-emitting device 1 was fabricated in the same manner as light-emitting device 1-1, except that mmtBumTPTzn-03 in light-emitting device 1-1 was replaced with DBfBB1TP. That is, comparative light-emitting device 1 is a light-emitting device in which the cap layer is formed of a single layer film of DBfBB1TP.

[0529] 22 shows the results of measuring the ordinary refractive index (n, Ordinary) and extraordinary refractive index (n, Extra-Ordinary) of mmtBumTPTzn-03, oBP-mmtBumBPTzn, mmtBumBP2Tzn, and DBfBB1TP used in light-emitting devices 1-1 to 1-3 and comparative light-emitting device 1 fabricated in this example. The measurements were performed using a spectroscopic ellipsometer (M-2000U manufactured by J.A. Woollam Japan). The measurement sample used was a film of the material to be measured formed on a quartz substrate to a thickness of approximately 50 nm by vacuum deposition.

[0530] 22 shows that mmtBumTPTzn-03, oBP-mmtBumBPTzn, and mmtBumBP2Tzn, which constitute the first layer 188 of light-emitting devices 1-1 to 1-3, are low-refractive-index materials with an ordinary refractive index of 1.8 or less at 450 nm, and DBfBB1TP, which constitutes the second layer 189, is a high-refractive-index material with an ordinary refractive index of 1.9 or more at 450 nm. It was also found that the difference between these two refractive indices was 0.1 or more. mmtBumTPTzn-03, oBP-mmtBumBPTzn, and mmtBumBP2Tzn are organic compounds having a skeleton with electron-transporting properties and a saturated hydrocarbon group.

[0531] The device structures of light-emitting devices 1-1 to 1-3 and comparative light-emitting device 1 are shown in Table 1 below.

[0532]

[0533] The luminance-current density characteristics of light-emitting devices 1-1 to 1-3 and comparative light-emitting device 1 are shown in Figure 23, the current efficiency-luminance characteristics in Figure 24, the luminance-voltage characteristics in Figure 25, the current density-voltage characteristics in Figure 26, the blue index-current density characteristics in Figure 27, and the electroluminescence spectrum in Figure 28.

[0534] Also, 1000 cd / cm ２ The values ​​of voltage, current, current density, CIE chromaticity, current efficiency, and blue index around 1000 kJ / cm are shown below. Note that the luminance, CIE chromaticity, and electroluminescence spectrum were measured using a spectroradiometer (SR-UL1R, manufactured by Topcon Corporation) at room temperature.

[0535]

[0536] 23 to 28 and Table 2 show that light-emitting devices 1-1 to 1-3, which are embodiments of the present invention, have higher current efficiency and blue index and thus have better luminous efficiency than the comparative light-emitting device 1. Stacking two materials with different ordinary refractive indices creates a refractive index step at the interface, enabling the development of a more efficient element.

[0537] In this example, a manufacturing method and characteristics of a light-emitting device 2, which is a light-emitting device of one embodiment of the present invention, and a comparative light-emitting device 2 will be described in detail. The structural formulae of main compounds used in the light-emitting device 2 and the comparative light-emitting device 2 are shown below.

[0538]

[0539] (Method of manufacturing light-emitting device 2) First, on a glass substrate, silver (Ag) was sequentially deposited by sputtering from the substrate side to a thickness of 100 nm as a reflective electrode, and indium tin oxide containing silicon oxide (ITSO) was sequentially deposited by sputtering to a thickness of 10 nm as a transparent electrode, to form a first electrode 101 measuring 2 mm x 2 mm. The transparent electrode functions as an anode, and is considered to be the first electrode 101 together with the reflective electrode.

[0540] Next, as a pretreatment for forming a light-emitting device on the substrate, the surface of the substrate was washed with water and baked at 200° C. for 1 hour.

[0541] After that, about 1 × 10 −４ The substrate was introduced into a vacuum deposition apparatus whose interior had been reduced in pressure to 100 Pa, and was vacuum baked at 170° C. for 60 minutes in a heating chamber within the vacuum deposition apparatus, after which the substrate was allowed to cool for approximately 30 minutes.

[0542] Next, the substrate was fixed to a holder provided in a vacuum deposition apparatus so that the surface on which the first electrode 101 was formed faced downward. N-(biphenyl-4-yl)-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-9,9-dimethyl-9H-fluoren-2-amine (abbreviation: PCBBiF) represented by the above structural formula (i) and an electron acceptor material (OCHD-003) containing fluorine and having a molecular weight of 672 were co-deposited by a deposition method on the inorganic insulating film and the first electrode 101 at a weight ratio of 1:0.03 (= PCBBiF:OCHD-003) to a film thickness of 10 nm, thereby forming a hole injection layer 111.

[0543] On the hole injection layer 111, PCBBiF was evaporated to a thickness of 103.5 nm to form a first hole transport layer, and then N,N-bis[4-(dibenzofuran-4-yl)phenyl]-4-amino-p-terphenyl (abbreviation: DBfBB1TP) represented by the above structural formula (ii) was evaporated to a thickness of 10 nm to form a second hole transport layer, thereby forming the hole transport layer 112.

[0544] Subsequently, on the hole-transport layer 112, 9-(1-naphthyl)-10-[4-(2-naphthyl)phenyl]anthracene (abbreviation: αN-βNPAnth) represented by the above structural formula (iii) and N,N'-diphenyl-N,N'-bis(9-phenyl-9H-carbazol-2-yl)naphtho[2,3-b;6,7-b']bisbenzofuran-3,10-diamine (abbreviation: 3,10PCA2Nbf(IV)-02) represented by the above structural formula (iv) were co-deposited at a weight ratio of 1:0.015 (=αN-βNPAnth:3,10PCA2Nbf(IV)-02) to a film thickness of 25 nm, to form a light-emitting layer 113.

[0545] Thereafter, 2-{3-[3-(N-phenyl-9H-carbazol-3-yl)-9H-carbazol-9-yl]phenyl}dibenzo[f,h]quinoxaline (abbreviation: 2mPCCzPDBq) represented by the above structural formula (v) was evaporated to a film thickness of 15 nm, and subsequently 2,2′-(1,3-phenylene)bis(9-phenyl-1,10-phenanthroline) (abbreviation: mPPhen2P) represented by the above structural formula (vi) was evaporated to a film thickness of 10 nm, thereby forming an electron transport layer 114.

[0546] Next, lithium fluoride (LiF) was evaporated to a thickness of 1 nm to form an electron injection layer 115, and then silver (Ag) and magnesium (Mg) were co-evaporated at a volume ratio of 1:0.1 to a thickness of 15 nm to form a second electrode 102.

[0547] Thereafter, 2-(3-(2,6-dimethylpyridin-3-yl)-5-{[3,5-bis(trifluoromethyl)]phenyl}phenyl)-4,6-diphenyl-1,3,5-triazine (abbreviation: mmCF3Ph-mDMePyPTzn) represented by the above structural formula (x) was evaporated on the second electrode 102 to a thickness of 12.5 nm to form a first layer 188. Furthermore, DBfBB1TP was evaporated on the first layer 188 to a thickness of 50 nm to form a second layer 189, thereby forming the cap layer 155.

[0548] Next, in a glove box with a nitrogen atmosphere, the light-emitting device was sealed with a glass substrate to prevent it from being exposed to the atmosphere (a UV-curable sealant was applied around the element, UV was irradiated only onto the sealant without irradiating the light-emitting device, and a heat treatment was performed at 80°C under atmospheric pressure for 1 hour), thereby forming light-emitting device 2.

[0549] (Method of Fabricating Comparative Light-Emitting Device 2) Comparative light-emitting device 2 was fabricated in the same manner as light-emitting device 2, except that mmCF3Ph-mDMePyPTzn in light-emitting device 2 was replaced with DBfBB1TP. That is, comparative light-emitting device 2 is a light-emitting device in which the cap layer is formed of a single layer film of DBfBB1TP.

[0550] 29 shows the results of measuring the ordinary refractive index (n, Ordinary) and extraordinary refractive index (n, Extra-Ordinary) of mmCF3Ph-mDMePyPTzn and DBfBB1TP used in the light-emitting device 2 fabricated in this example and the comparative light-emitting device 2. The measurements were performed using a spectroscopic ellipsometer (M-2000U manufactured by J.A. Woollam Japan). The measurement samples used were films formed on a quartz substrate with the materials of each layer by vacuum deposition to a thickness of approximately 50 nm.

[0551] 29, it was found that mmCF3Ph-mDMePyPTzn, which constitutes the first layer 188 of the light-emitting device 2, is a low-refractive index material with an ordinary refractive index of 1.8 or less at 450 nm, and DBfBB1TP, which constitutes the second layer 189, is a high-refractive index material with an ordinary refractive index of 1.9 or more at 450 nm. It was also found that the difference between these two refractive indices is 0.1 or more. mmCF3Ph-mDMePyPTzn is an organic compound having a skeleton with electron transport properties and a saturated hydrocarbon group.

[0552] The device structures of light-emitting device 2 and comparative light-emitting device 2 are shown in Table 3.

[0553]

[0554] The luminance-current density characteristics of light-emitting device 2 and comparative light-emitting device 2 are shown in Figure 30, the current efficiency-luminance characteristics in Figure 31, the luminance-voltage characteristics in Figure 32, the current density-voltage characteristics in Figure 33, the blue index-current density characteristics in Figure 34, and the electroluminescence spectrum in Figure 35.

[0555] Also, 1000 cd / cm ２ The values ​​of voltage, current, current density, CIE chromaticity, current efficiency, and blue index around 1000 kJ / cm2 are shown below. The luminance, CIE chromaticity, and electroluminescence spectrum were measured using a spectroradiometer (SR-UL1R, manufactured by Topcon Corporation) at room temperature.

[0556]

[0557] 30 to 35 and Table 4 show that light-emitting device 2 is a light-emitting device with a high luminous efficiency and favorable current efficiency and blue index compared to the comparative light-emitting device. By stacking two materials with different ordinary refractive indices, a refractive index step is created at the interface, enabling the development of a more efficient element.

[0558] Reference Examples Reference Synthesis Example 1 In this Reference Example, a synthesis method for 2-(3-(2,6-dimethylpyridin-3-yl)-5-{[3,5-bis(trifluoromethyl)]phenyl}phenyl)-4,6-diphenyl-1,3,5-triazine (abbreviation: mmCF3Ph-mDMePyPTzn) (structural formula (x)) used in Example 2 will be described. The structure of mmCF3Ph-mDMePyPTzn is shown below.

[0559]

[0560] <Step 1: Synthesis of 2-(3-chloro-5-{[3,5-bis(trifluoromethyl)]phenyl}phenyl)-4,6-diphenyl-1,3,5-triazine> 4.9 g (11.5 mmol) of 2-(3-bromo-5-chlorophenyl)-4,6-diphenyl-1,3,5-triazine, 4.0 g (15.5 mmol) of 3,5-bis(trifluoromethyl)phenylboronic acid, 3.2 g (23.0 mmol) of potassium carbonate, 56 mL of toluene, 28 mL of ethanol (abbreviation: EtOH), and 12 mL of water were placed in a three-neck flask, and the mixture was stirred under reduced pressure to degas the mixture. After degassing, palladium(II) acetate (abbreviation: Pd(OAc) ２ ) 26 mg (0.12 mmol), tris(2-methylphenyl)phosphine (abbreviation: P(o-tolyl) ３ 0.14 g (0.46 mmol) of 2-(2-methyl-2-propanol)-2-propanol (2-methyl-2-propanol) was added and stirred at 80° C. for 14 hours. After the reaction was completed, the reaction solution was filtered to obtain a gray solid. This solid was purified by silica gel column chromatography (developing solvent: toluene) to obtain 5.3 g (yield: 84%) of the target white solid. The synthesis scheme of Step 1 is shown in formula (s-1) below.

[0561]

[0562] <Step 2: Synthesis of 2-(3-{[4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl]phenyl}-5-{[3,5-bis(trifluoromethyl)]phenyl})-4,6-diphenyl-1,3,5-triazine> 5.3 g (9.6 mmol) of 2-(3-chloro-5-{[3,5-bis(trifluoromethyl]phenyl}phenyl)-4,6-diphenyl-1,3,5-triazine obtained in Step 1, 3.7 g (14.4 mmol) of bis(pinacolato)diboron, 2.8 g (28.8 mmol) of potassium acetate, and 150 mL of 1,4-dioxane were added to a three-neck flask, and the mixture was stirred under reduced pressure to degas the mixture. After degassing, palladium(II) acetate (abbreviated as Pd(OAc) ２22 mg (96 μmol) of dicyclohexyl(2′,4′,6′-triisopropyl-biphenyl-2-yl)phosphine (abbreviation: XPhos) and 92 mg (0.19 mmol) of dicyclohexyl(2′,4′,6′-triisopropyl-biphenyl-2-yl)phosphine were added, and the mixture was stirred at 100° C. for 14 hours. After the reaction was completed, water was added to the mixture, and the mixture was separated into an organic layer and an aqueous layer. The aqueous layer was extracted with toluene, and the extracted solution and the organic layer were combined and dried over magnesium sulfate. The mixture was gravity filtered, and the resulting filtrate was concentrated to obtain a pale yellow solid. This solid was purified by silica gel chromatography (developing solvent: toluene:hexane=1:1, followed by toluene), and 5.2 g (yield: 83%) of the desired white solid was obtained. The synthesis scheme for Step 2 is shown below in (s-2).

[0563]

[0564] <Step 3: Synthesis of mmCF3Ph-mDMePyPTzn> 5.2 g (8.0 mmol) of 2-(3-{[4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl]phenyl}-5-{[3,5-bis(trifluoromethyl)]phenyl})-4,6-diphenyl-1,3,5-triazine obtained in Step 2, 1.3 g (6.9 mmol) of 3-bromo-2,6-dimethylpyridine, 4.4 g (20.8 mmol) of tripotassium phosphate, 40 ml of tetrahydrofuran (abbreviation: THF), and 11 ml of water were added to a three-neck flask, and the mixture was stirred under reduced pressure to degas the mixture. After degassing, palladium(II) acetate (abbreviation: Pd(OAc) ２16 mg (69 μmol) of dicyclohexyl(2',4',6'-triisopropyl-biphenyl-2-yl)phosphine (abbreviation: XPhos) and 66 mg (0.14 mmol) of dicyclohexyl(2',4',6'-triisopropyl-biphenyl-2-yl)phosphine were added, and the mixture was stirred at 65°C for 15 hours. After completion of the reaction, the reaction solution was filtered to obtain a gray solid. This solid was purified by silica gel column chromatography (developing solvent: toluene:ethyl acetate = 20:1, then toluene:ethyl acetate = 10:1) to obtain a white solid. This solid was recrystallized with a mixed solvent of toluene and ethanol to obtain 3.3 g of the desired white solid (yield: 76%). 3.1 g of the obtained solid was purified by sublimation using a train sublimation method. Sublimation purification was performed by heating at 235°C for 18 hours under a pressure of 6.6 Pa and an argon flow rate of 15 mL / min, followed by heating at 245°C for 21 hours. After purification by sublimation, the target white solid was obtained in a yield of 3.0 g and a recovery rate of 95%. The synthetic scheme of Step 3 is shown in formula (s-3) below.

[0565]

[0566] The white solid obtained in step 3 was analyzed by nuclear magnetic resonance spectroscopy ( １ The results of the analysis by H-NMR are shown below. From these results, it was found that mmCF3Ph-mDMePyPTzn, which is the organic compound represented by the above structural formula (x), was obtained in this synthesis example.

[0567] １ H-NMR. δ(CDCl ３ , 300MHz): 2.62 (s, 3H), 2.65 (s, 3H), 7.17 (d, 1H, J=7.5Hz), 7.56-7.67 (m, 7H), 7.75 (t, 1H, J=1. 7Hz), 7.96 (s, 1H), 8.17 (s, 2H), 8.76-8.80 (m, 4H), 8.82 (t, 1H, J = 1.5Hz), 8.96 (t, 1H, J = 1.7Hz)

[0568] 100A: display device, 100B: display device, 100C: display device, 100D: display device, 100E: display device, 100: display device, 101: first electrode, 101B: first electrode, 101G: first electrode, 101R: first electrode, 101W: first electrode, 102: second electrode, 103B: organic compound layer, 103Bf: EL film, 103G: organic compound layer, 103Gf: EL film, 103R: organic compound layer, 103Rf: EL film, 103: organic compound layer, 104: common layer, 110B: subpixel, 110G: subpixel, 110R: subpixel, 110W: subpixel, 110: Subpixel, 111: hole injection layer, 112B: conductive layer, 112R: conductive layer, 112: hole transport layer, 113: light-emitting layer, 114: electron transport layer, 115: electron injection layer, 116: charge generation layer, 117: p-type layer, 118: electron relay layer, 119: electron injection buffer layer, 120: substrate, 122: resin layer, 125f: inorganic insulating film, 125: inorganic insulating layer, 126B: conductive layer, 126R: conductive layer, 127a: insulating layer, 127f: insulating film, 127: insulating layer, 128: layer, 129B: conductive layer, 129R: conductive layer, 130B: light-emitting device, 130G: light-emitting device, 130R: light-emitting Device, 130: light-emitting device, 131: protective layer, 132B: colored layer, 132G: colored layer, 132R: colored layer, 140: connecting portion, 141: region, 142: adhesive layer, 151B: conductive layer, 151C: conductive layer, 151f: conductive film, 151G: conductive layer, 151R: conductive layer, 151: conductive layer, 152B: conductive layer, 152C: conductive layer, 152f: conductive film, 152G: conductive layer, 152R: conductive layer, 152: conductive layer, 153: insulating layer, 155: cap layer, 156B: insulating layer, 156C: insulating layer, 156f: insulating film, 156G: insulating layer, 156R: insulating layer, 156: insulating layer Edge layer, 157: light-shielding layer, 158B: sacrificial layer, 158Bf: sacrificial film, 158f: sacrificial film, 158G: sacrificial layer, 158Gf: sacrificial film, 158R: sacrificial layer, 158Rf: sacrificial film, 159B: mask layer, 159Bf: mask film, 159G: mask layer, 159Gf: mask film, 159R: mask layer, 159Rf: mask film, 166: conductive layer, 171: insulating layer, 172: conductive layer, 173: insulating layer, 174: insulating layer, 175: insulating layer, 176: plug, 177: pixel portion, 178: pixel, 178a: pixel, 178b: pixel, 179: conductive layer, 190B: resist mask,190G: resist mask, 190R: resist mask, 191: resist mask, 201: transistor, 204: connection portion, 205: transistor, 211: insulating layer, 213: insulating layer, 214: insulating layer, 215: insulating layer, 221: conductive layer, 222a: conductive layer, 222b: conductive layer, 223: conductive layer, 224B: conductive layer, 224C: conductive layer, 224G: conductive layer, 224R: conductive layer, 231: semiconductor layer, 240: capacitor, 241: conductive layer, 242: connection layer, 243: insulating layer, 245: conductive layer, 254: insulating layer, 255: insulating layer, 256: plug, 261: insulating layer, 271: plug, 280: display module, 281: display section, 282: circuit section, 283a: pixel circuit, 283: pixel circuit section, 284a: pixel, 284: pixel section, 285: terminal section, 286: wiring section, 290: FPC, 291: substrate, 292: substrate, 301: substrate, 310: transistor, 311: conductive layer, 312: low resistance region, 313: insulating layer, 314: insulating layer, 315: element isolation layer, 317: light-shielding layer, 351: substrate, 352: substrate, 353: FPC, 354: IC, 355: wiring, 356: circuit, 501: first electrode, 502: second electrode, 511: first light-emitting unit, 512: second light-emitting unit, 513: intermediate layer, 600: light-emitting device, 601: source line driving circuit, Drive circuit section, 602: pixel section, 603: gate line drive circuit, 604: sealing substrate, 605: seal material, 607: space, 608: routing wiring, 610: element substrate, 611: switching FET, 612: current control FET, 613: first electrode, 614: insulator, 616: organic compound layer, 617: second electrode, 618: light emitting device, 623: FET, 700A: electronic device, 700B: electronic device, 721: housing, 723: wearing section, 727: earphone section, 750: earphone, 751: front display panel, 753: optical member, 756: display area, 757: frame, 758: nose pad, 800A: electronic device, 800B: electronic device, 820: display unit, 821: housing, 822: communication unit, 823: wearing unit, 824: control unit, 825: imaging unit, 827: earphone unit, 832: lens, 6500: electronic device, 6501: housing, 6502: display unit, 6503: power button, 6504: button, 6505: speaker, 6506: microphone, 6507: camera, 6508: light source, 6510: protective member,6511: Display panel, 6512: Optical member, 6513: Touch sensor panel, 6515: FPC, 6516: IC, 6517: Printed circuit board, 6518: Battery, 7000: Display unit, 7100: Television device, 7151: Remote control device, 7171: Housing, 7173: Stand, 7200: Notebook personal computer, 7211: Housing, 7212: Keyboard, 7213: Pointing device, 7214: External connection port, 7300: Digital signage, 7301: Housing, 7303: Speaker, 7 311: information terminal, 7400: digital signage, 7401: pillar, 7411: information terminal, 9000: housing, 9001: display unit, 9002: camera, 9003: speaker, 9005: operation keys, 9006: connection terminal, 9007: sensor, 9008: microphone, 9050: icon, 9051: information, 9052: information, 9053: information, 9054: information, 9055: hinge, 9171: mobile information terminal, 9172: mobile information terminal, 9173: tablet terminal, 9200: mobile information terminal, 9201: mobile information terminal,

Claims

a first electrode; a second electrode; and a light-emitting layer located between the first electrode and the second electrode, and a cap layer; the second electrode is located between the light-emitting layer and the capping layer; the cap layer comprises at least a first material and a second material; the first substance and the second substance are substances whose refractive indices for ordinary light at any wavelength from 380 nm to 760 nm in the respective vapor-deposited films differ by 0.1 or more, The first substance is an organic compound having a skeleton with electron transporting properties and a saturated hydrocarbon group. a first electrode; a second electrode; and a light-emitting layer located between the first electrode and the second electrode, and a cap layer; the second electrode is located between the light-emitting layer and the capping layer; the cap layer has at least a first layer including a first material and a second layer including a second material; the first substance and the second substance are substances whose refractive indices for ordinary light at any wavelength from 380 nm to 760 nm in the respective vapor-deposited films differ by 0.1 or more, The first substance is an organic compound having a skeleton with electron transporting properties and a saturated hydrocarbon group. a first electrode; a second electrode; and a light-emitting layer located between the first electrode and the second electrode, and a cap layer; the second electrode is located between the light-emitting layer and the capping layer; the cap layer has at least a first layer including a second material and a second layer including the first material; the first layer is located between the second electrode and the second layer; the first substance and the second substance are substances whose refractive indices for ordinary light at any wavelength from 380 nm to 760 nm in the respective vapor-deposited films differ by 0.1 or more, The first substance is an organic compound having a skeleton with electron transporting properties and a saturated hydrocarbon group. a first electrode; a second electrode; and a light-emitting layer located between the first electrode and the second electrode, and a cap layer; the second electrode is located between the light-emitting layer and the capping layer; the cap layer has at least a first layer including a first material and a second layer including a second material; the first layer is in contact with the second electrode; the first substance and the second substance are substances whose refractive indices for ordinary light at any wavelength from 380 nm to 760 nm in the respective vapor-deposited films differ by 0.1 or more, The first substance is an organic compound having a skeleton with electron transporting properties and a saturated hydrocarbon group. a first electrode; a second electrode; and a light-emitting layer located between the first electrode and the second electrode, and a cap layer; the second electrode is located between the light-emitting layer and the capping layer; the cap layer has at least a first layer including a first material and a second layer including a second material; the first substance and the second substance are substances whose refractive indices for ordinary light at any wavelength from 380 nm to 760 nm in the respective vapor-deposited films differ by 0.1 or more, the first substance is an organic compound having a skeleton having an electron transport property and a saturated hydrocarbon group, A light-emitting device wherein the second material is an organic compound. In any one of claims 1 to 5, A light-emitting device, wherein the first substance has 1 or more and 10 or less saturated hydrocarbon groups. In any one of claims 1 to 5, The saturated hydrocarbon group is a branched alkyl group having 3 or more carbon atoms. In any one of claims 1 to 5, The first substance and the second substance are substances whose refractive indices for ordinary light at any wavelength from 380 nm to 760 nm in the evaporated films thereof differ by 0.3 or more. In any one of claims 1 to 5, the light-emitting device has an electron transport layer between the light-emitting layer and the second electrode; A light-emitting device wherein the electron transport layer comprises the first material. In any one of claims 1 to 5, The light-emitting device, wherein the first substance is an organic compound represented by the following general formula (G1): (In the above general formula (G1), Q １ ~Q ６ represents N (nitrogen atom) or C (carbon atom), and Q １ ~Q ６ 1 to 3 are N, and the remaining C is R １ n is any one of 1 to 5, and n R １ may be the same or different. １ each independently represents hydrogen (including deuterium), a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms, a substituted or unsubstituted alicyclic group having 3 to 10 carbon atoms, a substituted or unsubstituted aromatic hydrocarbon group having 6 to 30 carbon atoms, or a substituted or unsubstituted heteroaromatic hydrocarbon group having 1 to 30 carbon atoms. １ At least one or n R １ At least one of the substituents of is either a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms or a substituted or unsubstituted alicyclic group having 3 to 10 carbon atoms. In claim 10, the refractive index of ordinary light at 450 nm in a vapor-deposited film of the first substance is 1.70 or less; A light-emitting device in which the refractive index of ordinary light at 450 nm in the vapor-deposited film of the second material is 1.80 or more.

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