Light-emitting element, light-emitting device, electronic device, and lighting device

Abstract

To provide a new organic compound, a new organic compound having carrier transport properties, a new organic compound having hole transport properties, an organic compound with a low refractive index, an organic compound having a low refractive index and carrier transport properties, and an organic compound having a low refractive index and hole transport properties.SOLUTION: There is provided an organic compound represented by the following general formula (G1).SELECTED DRAWING: Figure 1

Description

[Technical field]

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

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

[0003] Since such light-emitting elements are self-luminous, when used as display pixels, they have advantages such as high visibility and no need for backlighting compared to liquid crystals, making them suitable for use as flat panel display elements. Another major advantage of displays using such light-emitting elements is that they can be manufactured to be thin and lightweight. Another characteristic is that they have an extremely fast response speed.

[0004] In addition, these light-emitting devices can emit light in a planar manner because the light-emitting layer can be formed continuously in two dimensions. This is a feature that is difficult to obtain with point light sources such as incandescent light bulbs and LEDs, or linear light sources such as fluorescent lamps, making them highly useful as planar light sources for lighting and other applications.

[0005] Displays and lighting devices using such light-emitting elements are suitable for use in a variety of electronic devices, and research and development is ongoing to develop light-emitting elements with even better characteristics.

[0006] One of the problems that often comes up when talking about organic EL elements is their low light extraction efficiency. In particular, attenuation due to reflection caused by the difference in refractive index between adjacent layers is a major factor in reducing the efficiency of the element. In order to reduce this effect, a structure has been proposed in which a layer made of a low refractive index material is formed inside the EL layer (for example, see Non-Patent Document 1).

[0007] A light-emitting element having this configuration can be a light-emitting element having higher light extraction efficiency and therefore higher external quantum efficiency than a light-emitting element having a conventional configuration, but it is not easy to form such a low refractive index layer inside the EL layer without adversely affecting other important properties of the light-emitting element. This is because there is a trade-off between a low refractive index and high carrier transportability or reliability when used in a light-emitting element. This problem is caused by the fact that the carrier transportability and reliability of organic compounds are largely derived from the presence of unsaturated bonds, and organic compounds with many unsaturated bonds tend to have a high refractive index. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] Japanese Patent Application Publication No. 11-282181 [Patent Document 2] JP 2009-91304 A [Patent Document 3] U.S. Patent Application Publication No. 2010 / 104969 [Non-Patent Document 1] Jaeho Lee and 12 others, "Synergetic electrode architecture for efficient graphene-based flexible organic light-emitting diodes", Nature COMMUNICATIONS, June 2, 2016, DOI:10.1038 / ncomms11791 Summary of the Invention [Problem to be solved by the invention]

[0009] An object of one embodiment of the present invention is to provide a novel organic compound. Alternatively, an object of one embodiment of the present invention is to provide a novel organic compound having a carrier transport property. Alternatively, an object of one embodiment of the present invention is to provide a novel organic compound having a hole transport property. An object of one embodiment of the present invention is to provide an organic compound having a small refractive index. Alternatively, an object of one embodiment of the present invention is to provide an organic compound having a small refractive index and a carrier transport property. Alternatively, an object of one embodiment of the present invention is to provide an organic compound having a small refractive index and a hole transport property.

[0010] Another object of another embodiment of the present invention is to provide a light-emitting element with high emission efficiency, or a light-emitting element, a light-emitting device, an electronic device, a display device, and an electronic device with low power consumption.

[0011] 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 effects other than these from the description in the specification, drawings, claims, etc.

[0012] It is sufficient for the present invention to solve any one of the above problems. [Means for solving the problem]

[0013] One embodiment of the present invention is an organic compound represented by the following general formula (G1).

[0014] [ka]

[0015] In the above general formula (G1), Ar 1 ~Ar 4 each independently represents a substituted or unsubstituted phenylene group, a substituted or unsubstituted biphenyldiyl group, or a substituted or unsubstituted triphenyldiyl group. 1 ~R 4 each independently represents a saturated hydrocarbon group having 5 to 12 carbon atoms or a substituted or unsubstituted cyclic saturated hydrocarbon group having 5 to 12 carbon atoms. In addition, m, n, p, and s each independently represent an integer of 0 to 3, provided that two or more of m, n, p, and s each independently represent an integer of 1 to 3.

[0016] Alternatively, in another aspect of the present invention, in the above-mentioned configuration, the Ar 1 and Ar 4 is a substituted or unsubstituted phenylene group.

[0017] Alternatively, in another aspect of the present invention, in the above-mentioned configuration, the Ar 2 and Ar 3 is a substituted or unsubstituted biphenyldiyl group.

[0018] Alternatively, in another aspect of the present invention, in the above-mentioned configuration, the Ar 1 ~Ar 4 is a substituted or unsubstituted phenylene group.

[0019] Alternatively, another embodiment of the present invention is an organic compound in which m, n, p, and s are 1 in any of the above structures.

[0020] Another embodiment of the present invention is an organic compound represented by the following general formula (G2).

[0021] [ka]

[0022] In the above general formula (G2), R 1 ~R 4 at least one of represents a saturated hydrocarbon group having 5 to 12 carbon atoms or a substituted or unsubstituted saturated cyclic hydrocarbon group having 5 to 12 carbon atoms, and the remaining groups each independently represent hydrogen, a saturated hydrocarbon group having 5 to 12 carbon atoms, or a substituted or unsubstituted saturated cyclic hydrocarbon group having 5 to 12 carbon atoms. In addition, m, n, p, and s each independently represent an integer of 0 to 3, but any two or more of m, n, p, and s each independently represent an integer of 1 to 3.

[0023] Another embodiment of the present invention is an organic compound represented by the following general formula (G4).

[0024] [ka]

[0025] In the above general formula (G4), R 1 ~R 4 at least one of represents a saturated hydrocarbon group having 5 to 12 carbon atoms or a substituted or unsubstituted saturated cyclic hydrocarbon group having 5 to 12 carbon atoms, and the remaining groups each independently represent hydrogen, a saturated hydrocarbon group having 5 to 12 carbon atoms, or a substituted or unsubstituted saturated cyclic hydrocarbon group having 5 to 12 carbon atoms. In addition, m, n, p, and s each independently represent an integer of 0 to 3, but any two or more of m, n, p, and s each independently represent an integer of 1 to 3.

[0026] Another embodiment of the present invention is an organic compound represented by the following general formula (G5).

[0027] [ka]

[0028] In the above general formula (G5), R 1 ~R 4 at least one of represents a saturated hydrocarbon group having 5 to 12 carbon atoms or a substituted or unsubstituted saturated cyclic hydrocarbon group having 5 to 12 carbon atoms, and the remaining groups each independently represent hydrogen, a saturated hydrocarbon group having 5 to 12 carbon atoms, or a substituted or unsubstituted saturated cyclic hydrocarbon group having 5 to 12 carbon atoms. In addition, m, n, p, and s each independently represent an integer of 0 to 3, but any two or more of m, n, p, and s each independently represent an integer of 1 to 3.

[0029] Another embodiment of the present invention is an organic compound represented by the following general formula (G3).

[0030] [ka]

[0031] In the above general formula (G3), R 1 ~R 4 each independently represents a hydrogen atom, a saturated hydrocarbon group having 5 to 12 carbon atoms, or a substituted or unsubstituted cyclic saturated hydrocarbon group having 5 to 12 carbon atoms.

[0032] Another embodiment of the present invention is an organic compound represented by the following general formula (G6).

[0033] [ka]

[0034] In the above general formula (G6), R 1 ~R 4 each independently represents a hydrogen atom, a saturated hydrocarbon group having 5 to 12 carbon atoms, or a substituted or unsubstituted cyclic saturated hydrocarbon group having 5 to 12 carbon atoms.

[0035] Alternatively, another aspect of the present invention is, in any one of the above configurations, 1 ~R 4 is an organic compound in which the aryl group is a cyclohexyl group.

[0036] Another embodiment of the present invention is an organic compound represented by the following structural formula:

[0037] [ka]

[0038] Another embodiment of the present invention is an organic compound represented by the following structural formula:

[0039] [ka]

[0040] Another embodiment of the present invention is a light-emitting element including a first electrode, a second electrode, and an EL layer located between the first electrode and the second electrode, in which the EL layer contains any of the organic compounds described above.

[0041] Alternatively, another embodiment of the present invention is a light-emitting element including a first electrode, a second electrode, and an EL layer located between the first electrode and the second electrode, the EL layer including at least a light-emitting layer and a hole-transport layer, and the hole-transport layer including any of the organic compounds described above.

[0042] Alternatively, another embodiment of the present invention is a light-emitting element including a first electrode, a second electrode, and an EL layer located between the first electrode and the second electrode, the EL layer including at least a light-emitting layer and a hole-injection layer, and the hole-injection layer including any of the organic compounds described above.

[0043] Another embodiment of the present invention is a light-emitting element including a first electrode, a second electrode, and an EL layer located between the first electrode and the second electrode, the EL layer including a light-emitting layer, a hole-transport layer, and a hole-injection layer, and the hole-transport layer and the hole-injection layer contain any of the organic compounds described above.

[0044] Another embodiment of the present invention is a light-emitting device including any of the above light-emitting elements and a transistor or a substrate.

[0045] Another embodiment of the present invention is a light-emitting device including the above light-emitting device, a sensor, an operation button, a speaker, or a microphone, It is an electronic device having the following:

[0046] Another embodiment of the present invention is a lighting device including the above-described light-emitting device and a housing.

[0047] Another embodiment of the present invention is an electronic device including any of the organic compounds described above.

[0048] In this specification, the term "light-emitting device" includes an image display device using a light-emitting element. The term "light-emitting (display) device" may also include a module in which a connector, such as an anisotropic conductive film or TCP (Tape Carrier Package), is attached to a light-emitting element, a module in which a printed wiring board is provided at the end of the TCP, or a module in which an IC (integrated circuit) is directly mounted on a light-emitting element by a COG (Chip On Glass) method. Furthermore, lighting fixtures and the like may have a light-emitting device. Effect of the Invention

[0049] According to one embodiment of the present invention, a novel organic compound can be provided. Alternatively, according to one embodiment of the present invention, a novel organic compound having a carrier-transporting property can be provided. Alternatively, according to one embodiment of the present invention, a novel organic compound having a hole-transporting property can be provided. According to one embodiment of the present invention, an organic compound having a low refractive index can be provided. Alternatively, according to one embodiment of the present invention, an organic compound having a low refractive index and a carrier-transporting property can be provided. Alternatively, according to one embodiment of the present invention, an organic compound having a low refractive index and a hole-transporting property can be provided.

[0050] According to another embodiment of the present invention, a light-emitting element with high emission efficiency can be provided. Alternatively, according to another embodiment of the present invention, a light-emitting element, a light-emitting device, an electronic device, a display device, and an electronic device with low power consumption can be provided.

[0051] 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 effects other than these from the description in the specification, drawings, claims, etc. [Brief description of the drawings]

[0052] [Figure 1] Schematic diagram of a light-emitting element. [Diagram 2] FIG. 1 is a conceptual diagram of an active matrix light-emitting device. [Diagram 3] FIG. 1 is a conceptual diagram of an active matrix light-emitting device. [Figure 4] FIG. 1 is a conceptual diagram of an active matrix light-emitting device. [Diagram 5] FIG. 1 is a conceptual diagram of a passive matrix light-emitting device. [Figure 6] FIG. [Figure 7] FIG. [Figure 8] FIG. [Figure 9]FIG. [Figure 10] FIG. [Figure 11] 1 is a diagram illustrating an in-vehicle display device and a lighting device. [Figure 12] FIG. [Figure 13] FIG. [Figure 14] 1H NMR chart of TAPC-02. [Figure 15] Absorption and emission spectra of TAPC-02 in toluene solution. [Figure 16] Absorption and emission spectra of TAPC-02 in a thin film state. [Figure 17] MS spectrum of TAPC-02. [Figure 18] 1H NMR chart of 4,4'-(1,1-cyclohexanediyl)bis{N-(4-cyclohexylphenyl)aminobenzene}. [Figure 19] 1H NMR chart of TAPC-03. [Figure 20] luminance-current density characteristics of the light-emitting element 1 and the comparative light-emitting element 1. [Figure 21] Current efficiency-luminance characteristics of the light-emitting element 1 and the comparative light-emitting element 1. [Figure 22] Luminance-voltage characteristics of the light-emitting element 1 and the comparative light-emitting element 1. [Diagram 23] Current-voltage characteristics of the light-emitting element 1 and the comparative light-emitting element 1. [Figure 24] 4 shows external quantum efficiency-luminance characteristics of the light-emitting element 1 and the comparative light-emitting element 1. [Diagram 25] 4 shows emission spectra of the light-emitting element 1 and the comparative light-emitting element 1. [Figure 26] Luminance-current density characteristics of light-emitting element 2. [Figure 27] Current efficiency-luminance characteristics of light-emitting element 2. [Figure 28] Luminance-voltage characteristics of light-emitting element 2. [Figure 29] Current-voltage characteristics of light-emitting element 2. [Diagram 30]External quantum efficiency-luminance characteristics of light-emitting element 2. [Diagram 31] Emission spectrum of light-emitting element 2. [Diagram 32] Luminance-current density characteristics of light-emitting element 3. [Diagram 33] Current efficiency-luminance characteristics of light-emitting element 3. [Diagram 34] Luminance-voltage characteristics of light-emitting element 3. [Diagram 35] Current-voltage characteristics of light-emitting element 3. [Diagram 36] External quantum efficiency-luminance characteristics of light-emitting element 3. [Figure 37] Emission spectrum of light-emitting element 3. [Figure 38] Refractive index vs. wavelength for TAPC and TAPC-02. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0053] Hereinafter, the 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 easily understood by those skilled in the art that the form and details of the present invention can be modified in various ways 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.

[0054] (Embodiment 1) Among organic compounds with carrier transport properties that can be used in organic EL elements, 1,1-bis-(4-bis(4-methyl-phenyl)-amino-phenyl)-cyclohexane (abbreviation: TAPC) is known as one of the materials with a low refractive index. By using a material with a low refractive index in the EL layer, it is possible to obtain a light-emitting element that exhibits high external quantum efficiency, so it is expected that the use of TAPC will result in a light-emitting element with good external quantum efficiency. However, TAPC has the problem of low heat resistance, which is disadvantageous in terms of reliability.

[0055] One method for obtaining a hole transport material having high heat resistance and good reliability is to introduce an unsaturated hydrocarbon group, particularly a cyclic unsaturated hydrocarbon group, into the molecule.

[0056] On the other hand, in order to obtain a material with a low refractive index, it is preferable to introduce a substituent with a low molecular refraction into the molecule, such as a saturated hydrocarbon group or a cyclic saturated hydrocarbon group.

[0057] Moreover, the material used as the carrier transport material in the organic EL device preferably has a skeleton with high carrier transportability, and in particular, it is preferable that the material has an aromatic amine skeleton.

[0058] Based on the above findings, the present inventors have discovered an organic compound that has a small refractive index and can be suitably used as a hole transport material in an organic EL device by bonding these substituents and skeletons as follows.

[0059] That is, an organic compound of one embodiment of the present invention is an organic compound represented by the following general formula (G1).

[0060] [ka]

[0061] In the above general formula (G1), Ar 1 ~Ar 4 each independently represents a substituted or unsubstituted phenylene group, a substituted or unsubstituted biphenyldiyl group, or a substituted or unsubstituted triphenyldiyl group.

[0062] In addition, Ar 1 and Ar 4 is preferably a substituted or unsubstituted phenylene group, and more preferably an unsubstituted phenylene group in consideration of the synthesis cost.

[0063] Also, Ar 2 and Ar 3is preferably a substituted or unsubstituted phenylene group or a substituted or unsubstituted biphenyldiyl group, more preferably a substituted or unsubstituted phenylene group for improving the sublimability, and further preferably an unsubstituted phenylene group in consideration of the synthesis cost.

[0064] Ar 1 ~Ar 4 When any of the above is a phenylene group having a substituent, a biphenyldiyl group having a substituent, or a triphenyldiyl group having a substituent, the substituent can be an alkyl group having 1 to 4 carbon atoms. Examples of the alkyl group having 1 to 4 carbon atoms can include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, an isobutyl group, and a tert-butyl group.

[0065] As mentioned above, Ar 1 ~Ar 4 is preferably an unsubstituted phenylene group, and the organic compound can be represented by the following general formula (G2).

[0066] [ka]

[0067] In addition, in the above general formula (G1), as described above, Ar 2 and Ar 3 is an unsubstituted biphenyldiyl group, and Ar 1 and Ar 4 is preferably an unsubstituted phenylene group. Such an organic compound can be represented by the following general formula (G4).

[0068] [ka]

[0069] In addition, in the above general formula (G1), Ar 2 and Ar 3 is an unsubstituted biphenyldiyl group, and Ar1 and Ar 4 is preferably an unsubstituted phenylene group, but Ar 2 and Ar 3 More preferably, is an unsubstituted 4,4'-biphenyldiyl group. Such an organic compound can be represented by the following general formula (G5).

[0070] [ka]

[0071] In the organic compounds represented by the general formulas (G1), (G2), (G4), and (G5), m, n, p, and s each independently represent an integer of 0 to 3, but any two or more of m, n, p, and s each independently represent an integer of 1 to 3.

[0072] From the viewpoint of ease of synthesis and stability, it is preferable that m, n, p and s are 1. Among the organic compounds represented by the above general formulae (G4) and (G5), such organic compounds can be represented by the following general formulae (G3) and (G6).

[0073] [ka]

[0074] [ka]

[0075] In the above general formulae (G1) to (G6), R 1 ~R 4 each independently represents a saturated hydrocarbon group having 5 to 12 carbon atoms or a substituted or unsubstituted cyclic saturated hydrocarbon group having 5 to 12 carbon atoms.

[0076] Examples of saturated hydrocarbon groups having 5 to 12 carbon atoms include a pentyl group, an isopentyl group, a sec-pentyl group, a tert-pentyl group, a neopentyl group, a hexyl group, an isohexyl group, a sec-hexyl group, a tert-hexyl group, a neohexyl group, a 3-methylpentyl group, a 2-methylpentyl group, a 2-ethylbutyl group, a 1,2-dimethylbutyl group, a 2,3-dimethylbutyl group, an octyl group, an isooctyl group, a 2,6-dimethylhexyl group, a tert-octyl group, a decane group, a 2,6-dimethyloctyl group, a 3,3-dimethyloctyl group, a 2-methylnonyl group, a 3-methylnonyl group, an undecyl group, and a dodecyl group. Examples of the cyclic saturated hydrocarbon group having 5 to 12 carbon atoms include a cyclopentyl group, a cyclohexyl group, a 1-methylcyclopentyl group, a 2-methylcyclopentyl group, a cycloheptyl group, a bicyclo[2,2,1]heptyl group, a cyclooctyl group, a bicyclo[2,2,2]octyl group, a cyclononyl group, a bicyclo[3,2,2]nonyl group, a bicyclo[3,3,1]nonyl group, a cyclodecyl group, a cycloundecyl group, a bicyclo[5,4,0]undecyl group, and a cyclododecyl group.

[0077] Also, R 1 ~R 4 When any of the above is a cyclic hydrocarbon group having 5 to 12 carbon atoms and has a substituent, the substituent can be an alkyl group having 1 to 4 carbon atoms. Examples of the alkyl group having 1 to 4 carbon atoms include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, an isobutyl group, and a tert-butyl group.

[0078] In addition, R 1 ~R 4 is effective as a substituent having a cyclic structure in order to reduce the refractive index more significantly if it is a substituent having the same number of carbon atoms from the viewpoint of atomic refraction or molecular refraction, and a normal-membered ring or a medium-membered ring substituent having six or more members is more preferable. However, when a large-membered ring substituent is introduced, the molecular weight increases, which may reduce the sublimability, and this may lead to decomposition, so a cyclohexyl group is preferable.

[0079] The organic compound having the above structure has a small refractive index and a hole transporting property, and therefore a light-emitting element using the organic compound can have a high external quantum efficiency.

[0080] Specific examples of organic compounds having the above structure are shown below.

[0081] [ka]

[0082] [ka]

[0083] [ka]

[0084] [ka]

[0085] [ka]

[0086] [ka]

[0087] [ka]

[0088] [ka]

[0089] [ka]

[0090] Next, an example of a method for synthesizing an organic compound represented by the following general formula (G1), which is one embodiment of the present invention, will be described.

[0091] [ka]

[0092] In the above general formula (G1), Ar 1 ~Ar 4 each independently represents a substituted or unsubstituted phenylene group, a substituted or unsubstituted biphenyldiyl group, or a substituted or unsubstituted triphenyldiyl group. 1 ~R 4 each independently represents a saturated hydrocarbon group having 5 to 12 carbon atoms or a substituted or unsubstituted cyclic saturated hydrocarbon group having 5 to 12 carbon atoms, and m, n, p and s each independently represent an integer of 1 to 3.

[0093] The organic compound represented by the above general formula (G1) can be synthesized by coupling 1,1-bis(4-aminophenyl)cyclohexane with an organic halide in the presence of a base using a metal catalyst, a metal, or a metal compound, as shown in the synthesis scheme below.

[0094] [ka]

[0095] In the above synthesis scheme, Ar 1 ~Ar 4 each independently represents a substituted or unsubstituted phenylene group, a substituted or unsubstituted biphenyldiyl group, or a substituted or unsubstituted triphenyldiyl group. 1 ~R 4each independently represents a saturated hydrocarbon group having 5 to 12 carbon atoms or a substituted or unsubstituted cyclic saturated hydrocarbon group having 5 to 12 carbon atoms, and m, n, p and s each independently represent an integer of 1 to 3.

[0096] When the above synthesis scheme is carried out as a Buchwald-Hartwig reaction, X represents a halogen or a triflate group. The halogen is preferably iodine, bromine, or chlorine. In this reaction, a palladium catalyst is used that uses a palladium complex or compound such as bis(dibenzylideneacetone)palladium(0) or allyl palladium chloride dimer(II) and a ligand such as tri(tert-butyl)phosphine, ditert-butyl(1-methyl-2,2-diphenylcyclopropyl)phosphine, or tricyclohexylphosphine that coordinates thereto. Examples of the base include organic bases such as sodium tert-butoxide and inorganic bases such as potassium carbonate. In addition, when a solvent is used, toluene, xylene, 1,3,5-trimethylbenzenebenzene, etc. can be used.

[0097] In addition, when the above synthesis scheme is carried out as an Ullmann reaction, X represents a halogen. As the halogen, iodine, bromine, or chlorine is preferable. Copper or a copper compound is used as a catalyst. It is preferable to use copper iodide (I) or copper acetate (II). As the base to be used, an inorganic base such as potassium carbonate is exemplified. In addition, as the solvent, 1,3-dimethyl-3,4,5,6-tetrahydro-2(1H)pyrimidinone (DMPU), N-methyl-2-pyrrolidone (NMP), toluene, xylene, 1,3,5-trimethylbenzene, etc. are used. However, the above solvents are not limited to these. In the Ullmann reaction, it is preferable to use DMPU, NMP, or 1,3,5-trimethylbenzene, which have high boiling points, because the target product can be obtained in a shorter time and with a higher yield at a reaction temperature of 100°C or higher. In addition, it is even more preferable to use a higher reaction temperature of 150°C or higher, so that DMPU is more preferably used.

[0098] As described above, the organic compound represented by general formula (G1) can be synthesized.

[0099] (Embodiment 2) A light-emitting element according to one embodiment of the present invention is illustrated in Fig. 1. The light-emitting element according to one embodiment of the present invention includes a first electrode 101, a second electrode 102, and an EL layer 103, and the organic compound described in Embodiment 1 is used for the EL layer.

[0100] The EL layer 103 includes a light-emitting layer 113 and may include a hole-injection layer 111 and / or a hole-transport layer 112. The light-emitting layer 113 contains a light-emitting material, and the light-emitting element of one embodiment of the present invention emits light from the light-emitting material. The light-emitting layer 113 may contain a host material or other materials. The organic compound of one embodiment of the present invention described in Embodiment 1 may be included in the light-emitting layer 113, the hole-transport layer 112, or the hole-injection layer 111, or any of them.

[0101] In addition, in FIG. 1, an electron transport layer 114 and an electron injection layer 115 are also shown, but the configuration of the light emitting device is not limited to these.

[0102] Since the organic compound has a good hole-transport property, it is effective to use the organic compound for the hole-transport layer 112. The organic compound of one embodiment of the present invention can be used for the hole-injection layer 111 using a film in which the organic compound and an acceptor substance are mixed.

[0103] Furthermore, the organic compound of one embodiment of the present invention can also be used as a host material. In addition, an exciplex of the electron-transporting material and the hole-transporting material may be formed by co-evaporation with the organic compound of one embodiment of the present invention. By forming an exciplex having an appropriate emission wavelength, effective energy transfer to the light-emitting material can be realized, and a light-emitting element having high efficiency and a long lifetime can be provided.

[0104] Since the organic compound of one embodiment of the present invention has a low refractive index, a light-emitting element with high external quantum efficiency can be obtained by using the organic compound inside the EL layer.

[0105] Next, examples of the detailed structure and materials of the light-emitting element will be described. As described above, the light-emitting element of one embodiment of the present invention has an EL layer 103 composed of multiple layers between a pair of electrodes, the first electrode 101 and the second electrode 102, and any part of the EL layer 103 contains the organic compound disclosed in Embodiment 1.

[0106] The first electrode 101 is preferably formed using a metal, alloy, conductive compound, or a 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, indium oxide-zinc oxide, and indium oxide containing tungsten oxide and zinc oxide (IWZO). These conductive metal oxide films are usually formed by a sputtering method, but may be formed by applying a sol-gel method or the like. As an example of a manufacturing method, indium oxide-zinc oxide may be formed by a sputtering method using a target containing indium oxide and 1 to 20 wt % zinc oxide. Indium oxide containing tungsten oxide and zinc oxide (IWZO) may also be formed by a sputtering method using a target containing indium oxide and 0.5 to 5 wt % tungsten oxide and 0.1 to 1 wt % zinc oxide. Other examples include gold (Au), platinum (Pt), nickel (Ni), tungsten (W), chromium (Cr), molybdenum (Mo), iron (Fe), cobalt (Co), copper (Cu), palladium (Pd), and nitrides of metal materials (e.g., titanium nitride). Graphene can also be used. By using a composite material described later for the layer in contact with the first electrode 101 in the EL layer 103, it becomes possible to select an electrode material regardless of the work function.

[0107] The EL layer 103 preferably has a laminated structure, but the laminated structure is not particularly limited, and various layer structures such as a hole injection layer, a hole transport layer, an electron transport layer, an electron injection layer, a carrier block layer, an exciton block layer, and a charge generation layer can be applied. In this embodiment, two types of structures will be described: a structure having an electron transport layer 114 and an electron injection layer 115 in addition to a hole injection layer 111, a hole transport layer 112, and a light-emitting layer 113 as shown in FIG. 1A; and a structure having an electron transport layer 114, an electron injection layer 115, and a charge generation layer 116 in addition to a hole injection layer 111, a hole transport layer 112, and a light-emitting layer 113 as shown in FIG. 1B. The materials constituting each layer are specifically described below.

[0108] The hole-injection layer 111 is a layer containing a substance having an acceptor property. As the substance having an acceptor property, either an organic compound or an inorganic compound can be used.

[0109] As the substance having acceptor properties, a compound having an electron-withdrawing group (halogen group or cyano group) can be used, and a compound having an electron-withdrawing group such as 7,7,8,8-tetracyano-2,3,5,6-tetrafluoroquinodimethane (abbreviation: F4-TCNQ), 3,6-difluoro-2,5,7,7,8,8-hexacyanoquinodimethane, chloranil, 2,3,6,7,10,11-hexacyano-1,4,5,8,9,12-hexaazatriphenylene (abbreviation: HAT-CN), 1,3,4,5,7,8-hexafluorotetracyano-naphthoquinodimethane (abbreviation: F6-TCNNQ) can be used. As the organic compound having acceptor properties, a compound in which an electron-withdrawing group is bonded to a condensed aromatic ring having a plurality of heteroatoms, such as HAT-CN, is thermally stable and preferable. Radialene derivatives having electron-withdrawing groups (especially halogen groups such as fluoro groups and cyano groups) [3] are preferred because they have very high electron-accepting properties. Specific examples include α,α',α''-1,2,3-cyclopropane triylidene tris[4-cyano-2,3,5,6-tetrafluorobenzeneacetonitrile], α,α',α''-1,2,3-cyclopropane triylidene tris[2,6-dichloro-3,5-difluoro-4-(trifluoromethyl)benzeneacetonitrile], and α,α',α''-1,2,3-cyclopropane triylidene tris[2,3,4,5,6-pentafluorobenzeneacetonitrile]. In addition to the organic compounds mentioned above, molybdenum oxide, vanadium oxide, ruthenium oxide, tungsten oxide, manganese oxide, and the like can be used as substances having electron-accepting properties. In addition, the hole injection layer 111 can also be formed from a phthalocyanine complex compound such as phthalocyanine (abbreviation: HPc) or copper phthalocyanine (CuPC), an aromatic amine compound such as 4,4'-bis[N-(4-diphenylaminophenyl)-N-phenylamino]biphenyl (abbreviation: DPAB) or N,N'-bis{4-[bis(3-methylphenyl)amino]phenyl}-N,N'-diphenyl-(1,1'-biphenyl)-4,4'-diamine (abbreviation: DNTPD), or a polymer such as poly(3,4-ethylenedioxythiophene) / poly(styrenesulfonic acid) (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.

[0110] In addition, a composite material in which an acceptor substance is contained in a substance having a hole-transporting property can be used as the hole-injection layer 111. By using a composite material in which an acceptor substance is contained in a substance having a hole-transporting property, a material for forming an electrode can be selected regardless of the work function. That is, not only a material having a high work function but also a material having a low work function can be used as the first electrode 101. Examples of the acceptor substance include organic compounds having an acceptor property such as 7,7,8,8-tetracyano-2,3,5,6-tetrafluoroquinodimethane (abbreviation: F4-TCNQ), chloranil, and 1,3,4,5,7,8-hexafluorotetracyano-naphthoquinodimethane (abbreviation: F6-TCNNQ), and transition metal oxides. In addition, oxides of metals belonging to Groups 4 to 8 of the periodic table can also be used. As the oxides of metals belonging to Groups 4 to 8 in the periodic table, vanadium oxide, niobium oxide, tantalum oxide, chromium oxide, molybdenum oxide, tungsten oxide, manganese oxide, rhenium oxide, etc. are preferred because of their high electron-accepting properties. Among them, molybdenum oxide is particularly preferred because it is stable in the air, has low hygroscopicity, and is easy to handle.

[0111] As the hole transporting substance used in the composite material, various organic compounds such as aromatic amine compounds, carbazole derivatives, aromatic hydrocarbons, and polymer compounds (oligomers, dendrimers, polymers, etc.) can be used. -6 cm 2 A substance having a hole mobility of 100 / Vs or more is preferable. Specific examples of organic compounds that can be used as a hole-transporting substance in a composite material are listed below.

[0112] Examples of aromatic amine compounds that can be used in the composite material include N,N'-di(p-tolyl)-N,N'-diphenyl-p-phenylenediamine (abbreviation: DTDPPA), 4,4'-bis[N-(4-diphenylaminophenyl)-N-phenylamino]biphenyl (abbreviation: DPAB), N,N'-bis{4-[bis(3-methylphenyl)amino]phenyl}-N,N'-diphenyl-(1,1'-biphenyl)-4,4'-diamine (abbreviation: DNTPD), 1,3,5-tris[N-(4-diphenylaminophenyl)-N-phenylamino]benzene (abbreviation: DPA3B), and 1,1-bis-(4-bis(4-methyl-phenyl)-amino-phenyl)-cyclohexane (abbreviation: TAPC). Specific examples of the carbazole derivative include 3-[N-(9-phenylcarbazol-3-yl)-N-phenylamino]-9-phenylcarbazole (abbreviation: PCzPCA1), 3,6-bis[N-(9-phenylcarbazol-3-yl)-N-phenylamino]-9-phenylcarbazole (abbreviation: PCzPCA2), 3-[N-(1-naphthyl)-N-(9-phenylcarbazol-3-yl)amino]-9-phenylcarbazole (abbreviation: PCzPCA3), Examples of suitable carbazoles that can be used include PCzPCN1, 4,4'-di(N-carbazolyl)biphenyl (CBP), 1,3,5-tris[4-(N-carbazolyl)phenyl]benzene (TCPB), 9-[4-(10-phenylanthracen-9-yl)phenyl]-9H-carbazole (CzPA), and 1,4-bis[4-(N-carbazolyl)phenyl]-2,3,5,6-tetraphenylbenzene.Examples of aromatic hydrocarbons include 2-tert-butyl-9,10-di(2-naphthyl)anthracene (abbreviation: t-BuDNA), 2-tert-butyl-9,10-di(1-naphthyl)anthracene, 9,10-bis(3,5-diphenylphenyl)anthracene (abbreviation: DPPA), 2-tert-butyl-9,10-bis(4-phenylphenyl)anthracene (abbreviation: t-BuDBA), 9,10-di(2-naphthyl)anthracene (abbreviation: DNA), 9,10-diphenylanthracene (abbreviation: DPAnth), 2-tert-butylanthracene (abbreviation: t-BuAnth), 9,10-bis(4-methyl-1-naphthyl)anthracene (abbreviation: DMNA), 2-tert- Butyl-9,10-bis[2-(1-naphthyl)phenyl]anthracene, 9,10-bis[2-(1-naphthyl)phenyl]anthracene, 2,3,6,7-tetramethyl-9,10-di(1-naphthyl)anthracene, 2,3,6,7-tetramethyl-9,10-di(2-naphthyl)anthracene, 9,9'-bianthryl, 10,10'-diphenyl-9,9'-bianthryl, 10,10'-bis(2-phenylphenyl)-9,9'-bianthryl, 10,10'-bis[(2,3,4,5,6-pentaphenyl)phenyl]-9,9'-bianthryl, anthracene, tetracene, rubrene, perylene, 2,5,8,11-tetra(tert-butyl)perylene, etc. In addition, pentacene, coronene, etc. can also be used. It may have a vinyl skeleton. Examples of aromatic hydrocarbons having a vinyl group include 4,4'-bis(2,2-diphenylvinyl)biphenyl (abbreviation: DPVBi) and 9,10-bis[4-(2,2-diphenylvinyl)phenyl]anthracene (abbreviation: DPVPA). Note that the organic compound of one embodiment of the present invention can also be used. Note that in this case, it is preferable to use F6-TCNNQ as the acceptor substance.

[0113] In addition, polymer compounds such as poly(N-vinylcarbazole) (abbreviation: PVK), poly(4-vinyltriphenylamine) (abbreviation: PVTPA), poly[N-(4-{N'-[4-(4-diphenylamino)phenyl]phenyl-N'-phenylamino}phenyl)methacrylamide] (abbreviation: PTPDMA), and poly[N,N'-bis(4-butylphenyl)-N,N'-bis(phenyl)benzidine] (abbreviation: Poly-TPD) can also be used.

[0114] Note that the organic compound of one embodiment of the present invention disclosed in Embodiment 1 is also a material having a hole-transport property and can be suitably used as a hole-transport substance used in the composite material. By using the organic compound of one embodiment of the present invention, a layer with a low refractive index can be formed inside the EL layer 103, and the external quantum efficiency of the light-emitting element can be improved.

[0115] In addition, the refractive index of the layer can be reduced by further mixing an alkali metal or alkaline earth metal fluoride with the composite material (preferably with an atomic ratio of fluorine atoms of 20% or more in the layer). This also makes it possible to form a layer with a low refractive index inside the EL layer 103, and improve the external quantum efficiency of the light-emitting element.

[0116] By forming the hole injection layer 111, the hole injection property is improved, and a light emitting element with a low driving voltage can be obtained. In addition, an organic compound having an acceptor property is an easy-to-use material because it is easy to evaporate and form a film.

[0117] The hole transport layer 112 is formed by including a material having a hole transport property. -6 cm 2 / Vs or more. The hole-transport layer 112 preferably contains an organic compound of one embodiment of the present invention. By containing the organic compound described in Embodiment 1 in the hole-transport layer 112, a layer with a low refractive index can be formed in the EL layer 103, and the external quantum efficiency of the light-emitting element can be improved.

[0118] Examples of the material having the hole transport property include 4,4'-bis[N-(1-naphthyl)-N-phenylamino]biphenyl (abbreviation: NPB), N,N'-bis(3-methylphenyl)-N,N'-diphenyl-[1,1'-biphenyl]-4,4'-diamine (abbreviation: TPD), 4,4'-bis[N-(spiro-9,9'-bifluoren-2-yl)-N-phenylamino]biphenyl (abbreviation: BSPB), 4-phenyl-4'-(9-phenylfluoren-9-yl)triphenylamine (abbreviation: BP AFLP), 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: P CBANB), 4,4'-di(1-naphthyl)-4''-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBNBB), 9,9-dimethyl-N-phenyl-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-fluoren-2-amine (abbreviation: PCBAF), N-phenyl-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-spiro-9,9'-bifluoren-2-amine (abbreviation: PCBASF) and other aromatic amines. Compounds with a carbazole skeleton, such as 1,3-bis(N-carbazolyl)benzene (abbreviation: mCP), 4,4'-di(N-carbazolyl)biphenyl (abbreviation: CBP), 3,6-bis(3,5-diphenylphenyl)-9-phenylcarbazole (abbreviation: CzTP), and 3,3'-bis(9-phenyl-9H-carbazole) (abbreviation: PCCP), and compounds with a carbazole skeleton, such as 4,4',4''-(benzene-1,3,5-triyl)tri(dibenzothiophene) (abbreviation: DBT3P-II), 2,Examples of the compounds include compounds having a thiophene skeleton such as 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), 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 and compounds having a carbazole skeleton are preferable because they have good reliability, high hole transportability, and contribute to reducing the driving voltage. Note that the substances exemplified as the materials having hole transport properties used for the composite material of the hole injection layer 111 can also be suitably used as the material for forming the hole transport layer 112.

[0119] The light-emitting layer 113 is a layer containing a host material and a light-emitting material. The light-emitting material may be a fluorescent material, a phosphorescent material, a material exhibiting thermally activated delayed fluorescence (TADF), or other light-emitting material. The light-emitting layer 113 may be a single layer or may be composed of multiple layers containing different light-emitting materials.

[0120] 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.

[0121] 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 (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: 2PCAPPA), 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-carbazol-3-amine (abbreviation: 2PCAPA), N-[9,10-bis(1,1'-biphenyl-2-yl)-2-anthryl]-N,9-diphenyl-9H-carbazol-3-amine (abbreviation: 2PCABPhA), N-(9,10-diphenyl-2-anthryl)-N,N',N'-triphenyl-1,4-phenylenediamine (abbreviation: 2DPAPA), N-[9,10-bis(1,1'-biphenyl-2-yl)-2-anthryl]-N,N',N'-triphenyl-1,4-phenylenediamine (abbreviation: 2DPA BPhA), 9,10-bis(1,1'-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(1,1'-biphenyl-4-yl)-6,11-diphenyltetracene (abbreviation: BPT), 2-(2-{2-[4-(dimethylamino)phenyl]ethenyl}-6 -methyl-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 Amine (abbreviation: 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: BisDCJTM), N,N'-diphenyl-N,N'-(1,6-pyren-diyl)bis[(6-phenylbenzo[b]naphtho[1,2-d]furan)-8-amine] (abbreviation: 1,6BnfAPrn-03), and the like. In particular, condensed aromatic diamine compounds, such as pyrene diamine compounds, such as 1,6FLPAPrn, 1,6mMemFLPAPrn, and 1,6BnfAPrn-03, are preferred because they have high hole trapping properties, excellent luminous efficiency, and excellent reliability.

[0122] Examples of materials that can be used as the phosphorescent material in the light-emitting layer 113 include the following:

[0123] Organometallic iridium complexes with 4H-triazole skeletons such as tris{2-[5-(2-methylphenyl)-4-(2,6-dimethylphenyl)-4H-1,2,4-triazol-3-yl-κN2]phenyl-κC}iridium(III) (abbreviation: [Ir(mpptz-dmp)3]), tris(5-methyl-3,4-diphenyl-4H-1,2,4-triazolato)iridium(III) (abbreviation: [Ir(Mptz)3]), tris[4-(3-biphenyl)-5-isopropyl-3-phenyl-4H-1,2,4-triazolato]iridium(III) (abbreviation: [Ir(iPrptz-3b)3]), and tris[3-methyl-1-(2-methylphenyl)-5-phenyl-1H-1,2,4-triazolato]iridium(III) (abbreviation: [Ir(iPrptz-3b)3]) are also available. Organometallic iridium complexes having a 1H-triazole skeleton, such as tris(1-methyl-5-phenyl-3-propyl-1H-1,2,4-triazolato)iridium(III) (abbreviation: [Ir(Prptz1-Me)3]), fac-tris[(1-2,6-diisopropylphenyl)-2-phenyl-1H-imidazole]iridium(III) (abbreviation: [Ir(iPrpmi)3]), tris[3-(2,6-dimethylphenyl)-7-methylimidazo[1,2-f]phenanthridinato]iridium(III) (abbreviation: [Ir(dmpimpt-Me)3]), and 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(CF3ppy)2(pic)]), bis[2-(4',6'-difluorophenyl)pyridinato-N,C 2’] Organometallic iridium complexes with phenylpyridine derivatives having electron-withdrawing groups as ligands, such as iridium(III) acetylacetonate (abbreviated as FIracac), are examples of such compounds that exhibit blue phosphorescence and have emission peaks at 440 nm to 520 nm.

[0124] In addition, 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-( Organometallic iridium complexes having a pyrimidine skeleton, such as (acetylacetonato)bis(3,5-dimethyl-2-phenylpyrazinato)iridium(III) (abbreviation: [Ir(mppr-Me)2(acac)]) and (acetylacetonato)bis(5-isopropyl-3-methyl-2-phenylpyrazinato)iridium(III) (abbreviation: [Ir(mppr-iPr)2(acac)]), and organometallic iridium complexes having a pyrazine skeleton, such as tris(2-phenylpyridinato-N,C 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’ In addition to organometallic iridium complexes having a pyridine skeleton such as iridium(III) acetylacetonate (abbreviation: [Ir(pq)2(acac)]), rare earth metal complexes such as tris(acetylacetonato)(monophenanthroline)terbium(III) (abbreviation: [Tb(acac)3(Phen)]) can be mentioned. These are compounds that mainly exhibit green phosphorescence, with an emission peak at 500 nm to 600 nm. Note that organometallic iridium complexes having a pyrimidine skeleton are particularly preferred because they are remarkably excellent in reliability and luminous efficiency.

[0125] In addition, organometallic iridium complexes having a pyrimidine skeleton, such as (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)]), and bis[4,6-di(naphthalen-1-yl)pyrimidinato](dipivaloylmethanato)iridium(III) (abbreviation: [Ir(d1npm)2(dpm)]), Organometallic iridium complexes with a pyrazine 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])]), and (acetylacetonato)bis[2,3-bis(4-fluorophenyl)quinoxalinato]iridium(III) (abbreviation: [Ir(Fdpq)2(acac)]), and tris(1-phenylisoquinolinato-N,C 2’ ) Iridium(III) (abbreviation: [Ir(piq)3]), bis(1-phenylisoquinolinato-N,C 2’ In addition to organometallic iridium complexes with a pyridine skeleton such as iridium(III) acetylacetonate (abbreviated as [Ir(piq)2(acac)]), platinum complexes such as 2,3,7,8,12,13,17,18-octaethyl-21H,23H-porphyrin platinum(II) (abbreviated as PtOEP), and rare earth metal complexes such as tris(1,3-diphenyl-1,3-propanedionato)(monophenanthroline)europium(III) (abbreviated as [Eu(DBM)3(Phen)]) and tris[1-(2-thenoyl)-3,3,3-trifluoroacetonato](monophenanthroline)europium(III) (abbreviated as [Eu(TTA)3(Phen)]) are examples of such compounds that exhibit red phosphorescence and have an emission peak at 600 nm to 700 nm. Furthermore, an organometallic iridium complex having a pyrazine skeleton can emit red light with good chromaticity.

[0126] In addition to the phosphorescent compounds described above, known phosphorescent light-emitting materials may be selected and used.

[0127] TADF materials include fullerene and its derivatives, acridine and its derivatives, eosin derivatives, etc. Also included are metal-containing porphyrins including magnesium (Mg), zinc (Zn), cadmium (Cd), tin (Sn), platinum (Pt), indium (In), palladium (Pd), etc. Examples of the metal-containing porphyrin include protoporphyrin-tin fluoride complex (SnF2(Proto IX)), mesoporphyrin-tin fluoride complex (SnF2(Meso IX)), hematoporphyrin-tin fluoride complex (SnF2(Hemato IX)), coproporphyrin tetramethyl ester-tin fluoride complex (SnF2(Copro III-4Me)), octaethylporphyrin-tin fluoride complex (SnF2(OEP)), etioporphyrin-tin fluoride complex (SnF2(Etio I)), and octaethylporphyrin-platinum chloride complex (PtCl2OEP), which are shown in the following structural formulas.

[0128] [ka]

[0129] In addition, 2-(biphenyl-4-yl)-4,6-bis(12-phenylindolo[2,3-a]carbazol-11-yl)-1,3,5-triazine (abbreviation: PIC-TRZ) shown in the following structural formula, 9-(4,6-diphenyl-1,3,5-triazin-2-yl)-9'-phenyl-9H,9'H-3,3'-bicarbazole (abbreviation: PCCzTzn), 9-[4-(4,6-diphenyl-1,3,5-triazin-2-yl)phenyl]-9'-phenyl-9H,9'H-3,3'-bicarbazole (abbreviation: PCCzPTzn), 2-[4-(10H-phenoxazin-10-yl)phenyl]-4,6-diphenyl-1,3,5-triazine (abbreviation: Heterocyclic compounds having both π-electron rich heteroaromatic rings and π-electron deficient heteroaromatic rings, 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[acridin-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, which is preferable. In addition, a substance in which a π-electron rich heteroaromatic ring and a π-electron deficient heteroaromatic ring are directly bonded is particularly preferable because the donor property of the π-electron rich heteroaromatic ring and the acceptor property of the π-electron deficient heteroaromatic ring are both strong, and the energy difference between the S1 level and the T1 level is small, so that thermally activated delayed fluorescence can be efficiently obtained. In addition, an aromatic ring bonded to an electron-withdrawing group such as a cyano group may be used instead of the π-electron deficient heteroaromatic ring.

[0130] [ka]

[0131] As the host material of the light-emitting layer, various carrier transporting materials such as a material having an electron transporting property or a material having a hole transporting property can be used.

[0132] As the material having a hole-transporting property, the substances exemplified as the material having a hole-transporting property contained in the hole-transporting layer 112 can be suitably used.

[0133] Examples of materials having electron transport properties include metal complexes such as bis(10-hydroxybenzo[h]quinolinato)beryllium(II) (abbreviation: BeBq2), 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), and 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: CO11), 2,2',2''-(1,3,5-benzene Heterocyclic compounds with polyazole skeletons such as 2-[3-(dibenzothiophen-4-yl)phenyl]dibenzo[f,h]quinoxaline (abbreviation: 2mDBTPDBq-II) and 2-[3'-(dibenzothiophen-4-yl)biphenyl-3-yl]dibenzo[f,h]quinoxaline (abbreviation: 2mDBTBP Heterocyclic compounds with diazine skeletons such as 2-[3'-(9H-carbazol-9-yl)biphenyl-3-yl]dibenzo[f,h]quinoxaline (abbreviation: 2mCzBPDBq), 4,6-bis[3-(phenanthren-9-yl)phenyl]pyrimidine (abbreviation: 4,6mPnP2Pm), and 4,6-bis[3-(4-dibenzothienyl)phenyl]pyrimidine (abbreviation: 4,6mDBTP2Pm-II), as well as 3,5-bis[3-(9H-carbazol-9-yl)phenyl]pyridine (abbreviation: 35DCzPPy), 1,3,Examples of the heterocyclic compounds include heterocyclic compounds having a pyridine skeleton, such as 5-tri[3-(3-pyridyl)-phenyl]benzene (abbreviation: TmPyPB). Among the above, heterocyclic compounds having a diazine skeleton and heterocyclic compounds having a pyridine skeleton are preferred because of their high reliability. In particular, heterocyclic compounds having a diazine (pyrimidine or pyrazine) skeleton have high electron transport properties and contribute to reducing the driving voltage.

[0134] When a fluorescent material is used as the light-emitting material, a material having an anthracene skeleton is suitable as the host material. When a material having an anthracene skeleton is used as the host material of the fluorescent material, it is possible to realize a light-emitting layer having both good light-emitting efficiency and durability. Since many materials having an anthracene skeleton have a deep HOMO level, one embodiment of the present invention can be suitably applied. As a material having an anthracene skeleton to be used as a host material, a diphenylanthracene skeleton, particularly a 9,10-diphenylanthracene skeleton, is preferable because it is chemically stable. In addition, when the host material has a carbazole skeleton, it is preferable because the hole injection and transport properties are improved, but when the host material contains a benzocarbazole skeleton in which a benzene ring is further condensed to carbazole, the HOMO is shallower by about 0.1 eV than carbazole, making it easier for holes to enter, which is more preferable. In particular, when the host material contains a dibenzocarbazole skeleton, it is preferable because the HOMO is shallower by about 0.1 eV than carbazole, 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. Examples of such a substance 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-anthracenyl)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), and the like.In particular, CzPA, cgDBCzPA, 2mBnfPPA, and PCzPA are preferred choices since they exhibit very good properties.

[0135] The host material may be a mixture of a plurality of substances, and when a mixture of host materials is used, it is preferable to mix a material having an electron transporting property with a material having a hole transporting property. By mixing a material having an electron transporting property with a material having a hole transporting property, the transporting property of the light-emitting layer 113 can be easily adjusted, and the recombination region can be easily controlled. The content ratio of the material having a hole transporting property to the material having an electron transporting property may be 1:9 to 9:1 (material having a hole transporting property:material having an electron transporting property).

[0136] In addition, these mixed materials may form an exciplex. It is preferable to select a combination that forms an exciplex that emits light that overlaps with the wavelength of the lowest energy absorption band of the light-emitting material, because this makes energy transfer smooth and allows efficient light emission. In addition, the use of this structure is preferable because the driving voltage is reduced.

[0137] The electron transport layer 114 is a layer containing a substance having an electron transport property. As the substance having an electron transport property, any of the substances exemplified above as the substance having an electron transport property that can be used as the host material can be used.

[0138] Between the electron transport layer 114 and the second electrode 102, a layer containing an alkali metal or an alkaline earth metal, such as lithium fluoride (LiF), cesium fluoride (CsF), calcium fluoride (CaF2), or a compound thereof 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 transport property containing an alkali metal or an alkaline earth metal or a compound thereof, or an electride. Examples of the electride include a substance in which electrons are added at a high concentration to a mixed oxide of calcium and aluminum.

[0139] Note that a layer in which a substance having an electron transporting property (preferably an organic compound having a bipyridine skeleton) contains a fluoride of the above alkali metal or alkaline earth metal at a concentration at which the substance is in a microcrystalline state or higher (50 wt % or higher) can be used as the electron-injection layer 115. Since the layer has a low refractive index, it is possible to provide a light-emitting element with better external quantum efficiency.

[0140] Alternatively, a charge generation layer 116 may be provided instead of the electron injection layer 115 (FIG. 1B). The charge generation layer 116 is a layer capable of injecting holes into a layer in contact with the cathode side of the layer and electrons into a layer in contact with the anode side of the layer by applying a potential. 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 capable of forming the hole injection layer 111. The P-type layer 117 may be formed by stacking a film containing an acceptor material and a film containing a hole transport material, which are materials that 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 second electrode 102, which is a cathode, to operate the light-emitting element. In addition, since the organic compound of one embodiment of the present invention is an organic compound having a low refractive index, a light-emitting element having good external quantum efficiency can be obtained by using the organic compound for the P-type layer 117.

[0141] It is preferable that the charge generating layer 116 is 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 .

[0142] The electron relay layer 118 contains at least a substance having an electron transporting property, and has a function of preventing an interaction between the electron injection buffer layer 119 and the P-type layer 117 and smoothly transferring electrons. The LUMO level of the substance having an electron transporting property contained in the electron relay layer 118 is preferably 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 in contact with the charge generating layer 116 in the electron transport layer 114. The specific energy level of the LUMO level of the substance having an electron transporting property used in the electron relay layer 118 is -5.0 eV or more, preferably -5.0 eV or more and -3.0 eV or less. Note that, as the substance having an electron transporting property 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.

[0143] The electron injection buffer layer 119 can be made of a material with high electron injection properties, such as an alkali metal, an alkaline earth metal, a rare earth metal, or a compound thereof (an alkali metal compound (including an oxide such as lithium oxide, a halide, or a carbonate such as lithium carbonate or cesium carbonate), an alkaline earth metal compound (including an oxide, a halide, or a carbonate), or a rare earth metal compound (including an oxide, a halide, or a carbonate)).

[0144] In addition, when the electron-injection buffer layer 119 is formed containing a substance having an electron-transporting property and a donor substance, as the donor substance, an alkali metal, an alkaline earth metal, a rare earth metal, and a compound thereof (an alkali metal compound (including an oxide such as lithium oxide, a halide, or a carbonate such as lithium carbonate or cesium carbonate), an alkaline earth metal compound (including an oxide, a halide, or a carbonate), or a rare earth metal compound (including an oxide, a halide, or a carbonate)), or an organic compound such as tetrathianaphthacene (abbreviation: TTN), nickelocene, or decamethylnickelocene can be used. Note that as the substance having an electron-transporting property, a material similar to the material constituting the electron-transporting layer 114 described above can be used.

[0145] The second electrode 102 may be made of a metal, alloy, electrically conductive compound, or mixture thereof having a small work function (specifically, 3.8 eV or less). Specific examples of such a cathode material include alkali metals such as lithium (Li) and 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 containing these elements (MgAg, AlLi), rare earth metals such as europium (Eu), ytterbium (Yb), and alloys containing these elements. However, by providing an electron injection layer between the second electrode 102 and the electron transport layer, various conductive materials such as Al, Ag, ITO, and indium oxide-tin oxide containing silicon or silicon oxide can be used as the second electrode 102 regardless of the magnitude of the work function. These conductive materials can be formed into films using dry methods such as vacuum deposition and sputtering, inkjet methods, spin coating methods, and the like. Also, it may be formed by a wet method using a sol-gel method, or may be formed by a wet method using a paste of a metal material.

[0146] In addition, various methods, whether dry or wet, can be used to form the EL layer 103. For example, a vacuum deposition method, a gravure printing method, an offset printing method, a screen printing method, an inkjet method, or a spin coating method may be used.

[0147] Moreover, the above-mentioned electrodes or layers may be formed using different film formation methods.

[0148] The configuration of the layers provided between the first electrode 101 and the second electrode 102 is not limited to the above. However, a configuration in which a light-emitting region where holes and electrons recombine is provided at a position away from the first electrode 101 and the second electrode 102 is preferable so as to suppress quenching caused by the proximity of the light-emitting region to the metals used in the electrodes and the carrier injection layer.

[0149] In addition, the hole transport layer and electron transport layer in contact with the light-emitting layer 113, particularly the carrier transport layer close to the recombination region in the light-emitting layer 113, are preferably composed of a substance having a band gap larger than the band gap of the light-emitting material constituting the light-emitting layer or the light-emitting material contained in the light-emitting layer, in order to suppress energy transfer from excitons generated in the light-emitting layer.

[0150] Next, an embodiment of a light-emitting element having a structure 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. 1(C). This light-emitting element has multiple light-emitting units between an anode and a cathode. One light-emitting unit has a structure almost similar to that of the EL layer 103 shown in FIG. 1(A). In other words, it can be said that the light-emitting element shown in FIG. 1(C) is a light-emitting element having multiple light-emitting units, and the light-emitting element shown in FIG. 1(A) or FIG. 1(B) is a light-emitting element having one light-emitting unit.

[0151] In Fig. 1(C), a first light-emitting unit 511 and a second light-emitting unit 512 are laminated between an anode 501 and a cathode 502, and a charge generation layer 513 is provided between the first light-emitting unit 511 and the second light-emitting unit 512. The anode 501 and the cathode 502 correspond to the first electrode 101 and the second electrode 102 in Fig. 1(A), respectively, and the same electrodes as those described in the description of Fig. 1(A) can be applied. In addition, the first light-emitting unit 511 and the second light-emitting unit 512 may have the same structure or different structures.

[0152] The charge generation 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 anode 501 and the cathode 502. That is, in FIG. 1C, when a voltage is applied so that the potential of the anode is higher than the potential of the cathode, the charge generation layer 513 may inject electrons into the first light-emitting unit 511 and inject holes into the second light-emitting unit 512.

[0153] The charge generation 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 realize low-voltage driving and low-current driving. When the anode side surface of the light-emitting unit is in contact with the charge generation layer 513, the charge generation layer 513 can also function as a hole injection layer of the light-emitting unit, and therefore the light-emitting unit does not need to be provided with a hole injection layer.

[0154] Furthermore, when an electron injection buffer layer 119 is provided in the charge generation 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, so that it is not necessarily necessary to form an electron injection layer in the light-emitting unit on the anode side.

[0155] 1C, a light-emitting element having two light-emitting units has been described, but the same can be applied to a light-emitting element having three or more light-emitting units stacked together. By disposing a plurality of light-emitting units between a pair of electrodes and separating them with a charge generation layer 513 as in the light-emitting element according to this embodiment, a high-luminance light-emitting element can be realized while keeping the current density low, and an element with a long life can be realized. In addition, a light-emitting device that can be driven at a low voltage and consumes low power can be realized.

[0156] In addition, by making the emission colors of the respective light-emitting units different, it is possible to obtain light emission of a desired color as the whole light-emitting element. For example, in a light-emitting element having two light-emitting units, it is possible to obtain a light-emitting element that emits white light as the whole light-emitting element by obtaining red and green emission colors from the first light-emitting unit and blue emission color from the second light-emitting unit.

[0157] In addition, each layer and electrode such as the above-mentioned EL layer 103, the first light-emitting unit 511, the second light-emitting unit 512, and the charge generation layer can be formed by using, for example, a deposition method (including a vacuum deposition method), a droplet discharge method (also called an ink-jet method), a coating method, a gravure printing method, etc. In addition, they may contain a low molecular weight material, a medium molecular weight material (including an oligomer and a dendrimer), or a polymer material.

[0158] (Embodiment 3) In this embodiment mode, a light-emitting device using the light-emitting element described in Embodiment 2 will be described.

[0159] In this embodiment, a light-emitting device manufactured using the light-emitting element described in Embodiment 2 will be described with reference to Fig. 2. Fig. 2(A) is a top view showing the light-emitting device, and Fig. 2(B) is a cross-sectional view taken along the lines AB and CD in Fig. 2(A). This light-emitting 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, for controlling light emission from the light-emitting element. Reference numeral 604 denotes a sealing substrate, 605 denotes a sealant, and the inside surrounded by the sealant 605 defines a space 607.

[0160] The lead wiring 608 is a wiring for transmitting signals input to the source line driving circuit 601 and the gate line driving circuit 603, and receives a video signal, a clock signal, a start signal, a reset signal, and the like from an FPC (flexible printed circuit) 609 serving as an external input terminal. Although only an FPC is shown here, a printed wiring board (PWB) may be attached to this FPC. In this specification, the light emitting device includes not only the light emitting device itself, but also a state in which an FPC or a PWB is attached to it.

[0161] Next, the cross-sectional structure will be described with reference to Fig. 2(B). 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 the pixel portion 602 are shown.

[0162] The element substrate 610 may be made of a substrate made of glass, quartz, organic resin, metal, alloy, semiconductor, or a plastic substrate made of FRP (Fiber Reinforced Plastics), PVF (Polyvinyl fluoride), polyester, acrylic resin, or the like.

[0163] The structure of the transistor used in the pixel or the driver circuit is not particularly limited. For example, the transistor may be an inverted staggered type transistor or a staggered type transistor. In addition, the transistor may be a top-gate type transistor or a bottom-gate type transistor. The semiconductor material used for the transistor is not particularly limited, and for example, silicon, germanium, silicon carbide, gallium nitride, or the like may be used. 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.

[0164] 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 a part) may be used. The use of a crystalline semiconductor is preferable because it can suppress deterioration of transistor characteristics.

[0165] Here, in addition to the transistors provided in the pixels and driver circuits, an oxide semiconductor is preferably used for semiconductor devices such as transistors used in touch sensors, which will be described later. In particular, an oxide semiconductor having a wider band gap than silicon is preferably used. By using an oxide semiconductor having a wider band gap than silicon, the current in the off state of the transistor can be reduced.

[0166] The oxide semiconductor preferably contains at least indium (In) or zinc (Zn), and more preferably contains an oxide represented by In-M-Zn oxide (M is a metal such as Al, Ti, Ga, Ge, Y, Zr, Sn, La, Ce, or Hf).

[0167] 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 has no grain boundaries between adjacent crystal parts.

[0168] By using such a material for the semiconductor layer, fluctuations in electrical characteristics are suppressed, and a highly reliable transistor can be realized.

[0169] In addition, the transistor having the above-mentioned semiconductor layer can hold charge accumulated in a capacitance 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 an image displayed in each display region. As a result, an electronic device with extremely low power consumption can be realized.

[0170] It is preferable to provide an undercoat film in order to stabilize the characteristics of the transistor. The undercoat film can be prepared as a single layer or a multilayer structure 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 undercoat 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 undercoat film need not be provided if it is not necessary.

[0171] The FET 623 indicates one of the transistors formed in the driving circuit section 601. The driving circuit may be formed of various CMOS circuits, PMOS circuits, or NMOS circuits. Although the present embodiment shows a driver-integrated type in which a driving circuit is formed on a substrate, this is not necessarily required, and the driving circuit may be formed externally instead of on the substrate.

[0172] In addition, 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 612. However, the present invention is not limited to this, and the pixel portion may be formed by combining three or more FETs and a capacitive element.

[0173] 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 type photosensitive acrylic resin film.

[0174] In order to improve the covering ability of an EL layer or the like to be formed later, a curved surface having a curvature is formed at the upper end or lower end of the insulator 614. For example, when a positive type photosensitive acrylic resin is used as the material of the insulator 614, it is preferable that only the upper end of the insulator 614 has a curved surface having a radius of curvature (0.2 μm to 3 μm). In addition, either a negative type photosensitive resin or a positive type photosensitive resin can be used as the insulator 614.

[0175] An EL 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 a material used for the first electrode 613 that functions as an anode. For example, in addition to 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, a laminated 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, can be used. Note that a laminated structure provides low resistance as wiring, good ohmic contact, and can further function as an anode.

[0176] The EL layer 616 is formed by various methods such as a deposition method using a deposition mask, an inkjet method, a spin coating method, etc. The EL layer 616 includes the configuration described in the embodiment 2. Other materials constituting the EL layer 616 may be low molecular weight compounds or high molecular weight compounds (including oligomers and dendrimers).

[0177] Furthermore, the second electrode 617 formed on the EL layer 616 and functioning as a cathode is preferably made of a material having a small work function (such as Al, Mg, Li, Ca, or alloys or compounds thereof (MgAg, MgIn, AlLi, etc.)). When light generated in the EL layer 616 is transmitted through the second electrode 617, the second electrode 617 is preferably made of a laminate of a thin metal thin film and a transparent conductive film (such as ITO, indium oxide containing 2 to 20 wt % zinc oxide, indium tin oxide containing silicon, zinc oxide (ZnO), etc.).

[0178] Note that a light-emitting element is formed with the first electrode 613, the EL layer 616, and the second electrode 617. The light-emitting element is the light-emitting element described in Embodiment 2. Note that a pixel portion is formed with a plurality of light-emitting elements, but the light-emitting device in this embodiment may include both the light-emitting elements described in Embodiment 2 and light-emitting elements having other structures.

[0179] Furthermore, by bonding the sealing substrate 604 to the element substrate 610 with a sealant 605, a structure is formed in which a light emitting element 618 is provided in a space 607 surrounded by the element substrate 610, the sealing substrate 604, and the sealant 605. The space 607 is filled with a filler, and may be filled with an inert gas (nitrogen, argon, etc.) or with a sealant. A recess is formed in the sealing substrate, and a desiccant is provided therein to suppress deterioration due to the influence of moisture, which is a preferable configuration.

[0180] It is preferable to use epoxy resin or glass frit for the sealing material 605. It is also preferable that these materials are as impermeable to moisture and oxygen as possible. In addition to glass and quartz substrates, materials that can be used for the sealing substrate 604 include plastic substrates made of FRP (Fiber Reinforced Plastics), PVF (Polyvinyl Fluoride), polyester, acrylic resin, etc.

[0181] Although not shown in Fig. 2, 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 be formed so as to cover the exposed portion of the sealant 605. The protective film may 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, etc.

[0182] The protective film can be made of a material that is difficult for impurities such as water to permeate, and therefore can effectively prevent impurities such as water from diffusing from the outside to the inside.

[0183] The protective film may be made of an oxide, a nitride, a fluoride, a sulfide, a ternary compound, a metal, a 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, 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; an oxide containing yttrium and zirconium, or the like.

[0184] The protective film is preferably formed using a film formation method with good step coverage. One such method is the atomic layer deposition (ALD) method. 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. In addition, it is possible to reduce damage to the processed member when forming the protective film.

[0185] 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 with complex uneven shapes, as well as on the top, side, and back surfaces of a touch panel.

[0186] In the above manner, a light-emitting device manufactured using the light-emitting element described in Embodiment 2 can be obtained.

[0187] A light-emitting device with favorable characteristics can be obtained in this embodiment mode because the light-emitting element described in Embodiment 2 is used in the light-emitting device in this embodiment mode. Specifically, since the light-emitting element described in Embodiment 2 has favorable emission efficiency, a light-emitting device with low power consumption can be obtained.

[0188] 3 shows an example of a light-emitting device in which a light-emitting element that emits white light is formed and a colored layer (color filter) is provided to achieve full color. In FIG. 3(A), a substrate 1001, a base insulating film 1002, a gate insulating film 1003, gate electrodes 1006, 1007, and 1008, a first interlayer insulating film 1020, a second interlayer insulating film 1021, a peripheral portion 1042, a pixel portion 1040, a driver circuit portion 1041, first electrodes 1024W, 1024R, 1024G, and 1024B of the light-emitting element, a partition wall 1025, an EL layer 1028, a second electrode 1029 of the light-emitting element, a sealing substrate 1031, a sealant 1032, and the like are illustrated.

[0189] In FIG. 3A, the colored layers (red colored layer 1034R, green colored layer 1034G, blue colored layer 1034B) are provided on a transparent base material 1033. A black matrix 1035 may be further provided. The transparent base material 1033 on which the colored layers and black matrix are provided is aligned and fixed to the substrate 1001. The colored layers and black matrix 1035 are covered with an overcoat layer 1036. In FIG. 3A, there are light-emitting layers from which light does not pass through the colored layers and goes out, and light-emitting layers from which light passes through the colored layers of each color and goes out. The light that does not pass through the colored layers is white, and the light that passes through the colored layers is red, green, and blue, so that an image can be expressed by four color pixels.

[0190] 3B shows an example in which colored layers (a red colored layer 1034R, a green colored layer 1034G, and a blue colored layer 1034B) are formed between the gate insulating film 1003 and the first interlayer insulating film 1020. In this manner, the colored layers may be provided between the substrate 1001 and the sealing substrate 1031.

[0191] In the light-emitting device described above, the light-emitting device has a structure (bottom emission type) in which light is extracted on the substrate 1001 side on which the FET is formed, but the light-emitting device may have a structure (top emission type) in which light is extracted on the sealing substrate 1031 side. A cross-sectional view of a top emission type light-emitting device is shown in FIG. 4. In this case, a substrate that does not transmit light can be used as the substrate 1001. The process is performed in the same manner as the bottom emission type light-emitting device until a connection electrode that connects the FET and the anode of the light-emitting element is formed. Thereafter, a third interlayer insulating film 1037 is formed to cover the electrode 1022. This insulating film may play a role of planarization. The third interlayer insulating film 1037 can be formed using the same material as the second interlayer insulating film, or other known materials.

[0192] The first electrodes 1024W, 1024R, 1024G, and 1024B of the light-emitting element are anodes here, but may be cathodes. In addition, in the case of a top-emission type light-emitting device as shown in FIG. 4, it is preferable that the first electrodes are reflective electrodes. The EL layer 1028 has the same structure as that of the EL layer 103 in the second embodiment, and has an element structure that can emit white light.

[0193] In the top emission structure as shown in FIG. 4, sealing can be performed with a sealing substrate 1031 provided with colored layers (red colored layer 1034R, green colored layer 1034G, blue colored layer 1034B). A black matrix 1035 may be provided on the sealing substrate 1031 so as to be located between pixels. The colored layers (red colored layer 1034R, green colored layer 1034G, blue colored layer 1034B) and the black matrix may be covered with an overcoat layer. Note that a substrate having light transmissivity is used as the sealing substrate 1031. In addition, although an example of full color display using four colors, red, green, blue, and white, is shown here, the present invention is not particularly limited, and full color display using four colors, red, yellow, green, and blue, or three colors, red, green, and blue, may be used.

[0194] In a top-emission type light-emitting device, a microcavity structure can be suitably applied. A light-emitting element having a microcavity structure is obtained by making the first electrode a reflective electrode and the second electrode a semi-transmissive / semi-reflective electrode. At least an EL layer is provided between the reflective electrode and the semi-transmissive / semi-reflective electrode, and at least a light-emitting layer that becomes a light-emitting region is provided.

[0195] The reflectance of the reflective electrode to visible light is 40% to 100%, preferably 70% to 100%, and the resistivity is 1×10 -2 The semi-transmitting and semi-reflective electrode has a visible light reflectance of 20% to 80%, preferably 40% to 70%, and a resistivity of 1×10 -2 It is assumed that the film has a resistance of less than Ωcm.

[0196] Light emitted from a light-emitting layer included in the EL layer is reflected by the reflective electrode and the semi-transmissive and semi-reflective electrode, causing resonance.

[0197] In this light-emitting device, the optical distance between the reflective electrode and the semi-transmissive / semi-reflective electrode can be changed by changing the thickness of the transparent conductive film, the above-mentioned composite material, the carrier transport material, etc. This makes it possible to intensify the light of a resonating wavelength between the reflective electrode and the semi-transmissive / semi-reflective electrode and attenuate the light of a non-resonating wavelength.

[0198] In addition, since the light reflected by the reflective electrode and returned (first reflected light) causes significant interference with the light (first incident light) that is directly incident on the semi-transmissive and semi-reflective electrode from the light-emitting layer, it is preferable to adjust the optical distance between the reflective electrode and the light-emitting layer to (2n-1)λ / 4 (where n is a natural number equal to or greater than 1, and λ is the wavelength of the emitted light to be amplified). By adjusting the optical distance, the phase of the first reflected light and the first incident light can be aligned, thereby further amplifying the light emitted from the light-emitting layer.

[0199] In the above configuration, the EL layer may have a structure having a plurality of light-emitting layers or a structure having a single light-emitting layer. For example, the EL layer may be combined with the above-mentioned tandem-type light-emitting element configuration, in which a single light-emitting element is provided with a plurality of EL layers sandwiched between a charge generating layer, and each EL layer is formed with a single or multiple light-emitting layers.

[0200] The microcavity structure makes it possible to increase the emission intensity of a specific wavelength in the front direction, thereby reducing power consumption. In the case of a light-emitting device that displays images using four sub-pixels of red, yellow, green, and blue, in addition to the brightness improvement effect of yellow emission, the microcavity structure that matches the wavelength of each color can be applied to all sub-pixels, resulting in a light-emitting device with good characteristics.

[0201] A light-emitting device with favorable characteristics can be obtained in this embodiment mode because the light-emitting element described in Embodiment 2 is used in the light-emitting device in this embodiment mode. Specifically, since the light-emitting element described in Embodiment 2 has favorable emission efficiency, a light-emitting device with low power consumption can be obtained.

[0202] Up to this point, active matrix type light emitting devices have been described, but from here on, passive matrix type light emitting devices will be described. FIG. 5 shows a passive matrix type light emitting device manufactured by applying the present invention. FIG. 5(A) is a perspective view showing the light emitting device, and FIG. 5(B) is a cross-sectional view taken along XY in FIG. 5(A). In FIG. 5, an EL layer 955 is provided between an electrode 952 and an electrode 956 on a substrate 951. An end of the electrode 952 is covered with an insulating layer 953. A partition layer 954 is provided on the insulating layer 953. The sidewalls of the partition layer 954 have an inclination such that the distance between one sidewall and the other sidewall becomes narrower as the sidewall approaches the substrate surface. That is, the cross section of the partition layer 954 in the short side direction is trapezoidal, and the bottom side (the side facing the same direction as the surface direction of the insulating layer 953 and in contact with the insulating layer 953) is shorter than the top side (the side facing the same direction as the surface direction of the insulating layer 953 and not in contact with the insulating layer 953). By providing the partition layer 954 in this manner, defects in the light-emitting element due to static electricity or the like can be prevented. In addition, the light-emitting element described in Embodiment 2 is used in a passive matrix light-emitting device, and the light-emitting device can be made to have high reliability or low power consumption.

[0203] The light-emitting device described above is capable of controlling each of a large number of minute light-emitting elements arranged in a matrix, and therefore can be suitably used as a display device for displaying images.

[0204] This embodiment mode can be freely combined with other embodiment modes.

[0205] (Embodiment 4) In this embodiment, an example in which the light-emitting element described in Embodiment 2 is used as a lighting device will be described with reference to Fig. 6. Fig. 6(B) is a top view of the lighting device, and Fig. 6(A) is a cross-sectional view taken along line ef in Fig. 6(B).

[0206] In the lighting device in this embodiment, a first electrode 401 is formed over a light-transmitting substrate 400, which is a support. The first electrode 401 corresponds to the first electrode 101 in Embodiment 2. When light is extracted from the first electrode 401 side, the first electrode 401 is formed using a light-transmitting material.

[0207] A pad 412 for supplying a voltage to the second electrode 404 is formed on the substrate 400 .

[0208] An EL layer 403 is formed over the first electrode 401. The EL layer 403 corresponds to the structure of the EL layer 103 in Embodiment 2, or a structure in which the light-emitting units 511 and 512 and the charge generation layer 513 are combined, or the like. For these structures, refer to the description thereof.

[0209] A second electrode 404 is formed to cover the EL layer 403. The second electrode 404 corresponds to the second electrode 102 in the second embodiment. When light is extracted from the first electrode 401 side, the second electrode 404 is formed of a material with high reflectivity. The second electrode 404 is connected to a pad 412 to supply a voltage.

[0210] As described above, the lighting device described in this embodiment has a light-emitting element having the first electrode 401, the EL layer 403, and the second electrode 404. Since the light-emitting element has high emission efficiency, the lighting device in this embodiment can have low power consumption.

[0211] The substrate 400 on which the light-emitting element having the above structure is formed and a sealing substrate 407 are fixed and sealed using sealants 405 and 406, thereby completing the lighting device. Either one of the sealants 405 and 406 may be used. A desiccant may be mixed into the inner sealant 406 (not shown in FIG. 6(B)), which can adsorb moisture and improve reliability.

[0212] Moreover, the pad 412 and a part of the first electrode 401 can be extended outside the sealing materials 405 and 406 to serve as an external input terminal. Also, an IC chip 420 equipped with a converter or the like may be provided thereon.

[0213] As described above, the lighting device described in this embodiment uses the light-emitting element described in Embodiment 2 as an EL element, and can be a light-emitting device with low power consumption.

[0214] (Embodiment 5) In this embodiment, an example of an electronic device including a light-emitting element described in Embodiment 2 will be described. The light-emitting element described in Embodiment 2 has high emission efficiency and low power consumption. As a result, the electronic device described in this embodiment can be an electronic device having a light-emitting portion with low power consumption.

[0215] Examples of electronic devices to which the light-emitting elements are applied include television devices (also called televisions or television receivers), monitors for computers, digital cameras, digital video cameras, digital photo frames, mobile phones (also called mobile phones or mobile phone devices), portable game machines, personal digital assistants, audio playback devices, large game machines such as pachinko machines, etc. Specific examples of these electronic devices are shown below.

[0216] 7A illustrates an example of a television set. The television set has a display portion 7103 incorporated in a housing 7101. Here, the housing 7101 is supported by a stand 7105. The display portion 7103 can display an image, and the light-emitting elements described in Embodiment 2 are arranged in a matrix.

[0217] The television device can be operated using an operation switch provided on the housing 7101 or a separate remote control 7110. Using operation keys 7109 provided on the remote control 7110, the channel and volume can be controlled, and an image displayed on the display portion 7103 can be operated. The remote control 7110 may be provided with a display portion 7107 that displays information output from the remote control 7110.

[0218] The television device is configured to include a receiver, a modem, etc. The receiver can receive general television broadcasts, and by connecting to a wired or wireless communication network via the modem, it is also possible to perform one-way (from sender to receiver) or two-way (between sender and receiver, or between receivers, etc.) information communication.

[0219] FIG. 7B1 shows a computer, which includes a main body 7201, a housing 7202, a display portion 7203, a keyboard 7204, an external connection port 7205, a pointing device 7206, and the like. Note that this computer is manufactured by using the light-emitting elements described in Embodiment 2 arranged in a matrix for the display portion 7203. The computer in FIG. 7B1 may have a form as shown in FIG. 7B2. The computer in FIG. 7B2 is provided with a second display portion 7210 instead of the keyboard 7204 and the pointing device 7206. The second display portion 7210 is a touch panel type, and input can be performed by operating a display for input displayed on the second display portion 7210 with a finger or a dedicated pen. The second display portion 7210 can display not only a display for input but also other images. The display portion 7203 may also be a touch panel. The two screens are connected by a hinge, which can prevent the screens from being scratched or broken during storage or transportation.

[0220] 7C shows a mobile phone, which is an example of a mobile terminal. The mobile phone includes a display portion 7402 built into a housing 7401, operation buttons 7403, an external connection port 7404, a speaker 7405, a microphone 7406, and the like. Note that the mobile phone has the display portion 7402 in which the light-emitting elements described in Embodiment 2 are arranged in a matrix.

[0221] 7C can be configured so that information can be input by touching the display portion 7402 with a finger or the like. In this case, operations such as making a call or composing an e-mail can be performed by touching the display portion 7402 with a finger or the like.

[0222] The screen of the display unit 7402 has three main modes. The first is a display mode that is mainly for displaying images, the second is an input mode that is mainly for inputting information such as characters, and the third is a display + input mode that combines the display mode and the input mode.

[0223] For example, when making a call or composing an e-mail, the display portion 7402 may be set to a character input mode mainly for inputting characters, and the character input operation may be performed by inputting characters displayed on the screen. In this case, it is preferable to display a keyboard or number buttons on most of the screen of the display portion 7402.

[0224] In addition, by providing a detection device having a sensor for detecting tilt, such as a gyro or an acceleration sensor, inside the mobile terminal, the orientation of the mobile terminal (portrait or landscape) can be determined and the screen display of the display portion 7402 can be automatically switched.

[0225] The screen mode can be switched by touching the display portion 7402 or by operating operation buttons 7403 on the housing 7401. The mode can also be switched depending on the type of image displayed on the display portion 7402. For example, if the image signal to be displayed on the display portion is moving image data, the mode is switched to the display mode, and if it is text data, the mode is switched to the input mode.

[0226] In addition, in the input mode, a signal detected by an optical sensor of the display portion 7402 may be detected, and if there is no input by a touch operation on the display portion 7402 for a certain period of time, the screen mode may be controlled to be switched from the input mode to the display mode.

[0227] The display portion 7402 can also function as an image sensor. For example, personal authentication can be performed by touching the display portion 7402 with a palm or a finger to capture an image of a palm print, a fingerprint, or the like. In addition, finger veins, palm veins, or the like can be captured by using a backlight that emits near-infrared light or a sensing light source that emits near-infrared light for the display portion.

[0228] Note that the structure described in this embodiment mode can be used by appropriately combining the structures described in any of Embodiment Modes 1 to 4.

[0229] As described above, the light-emitting device including the light-emitting element described in Embodiment 2 has a very wide range of application, and can be applied to electronic devices in a variety of fields. By using the light-emitting element described in Embodiment 2, electronic devices with low power consumption can be obtained.

[0230] FIG. 8(A) is a schematic diagram showing an example of a cleaning robot.

[0231] The cleaning robot 5100 has a display 5101 arranged on the top surface, a plurality of cameras 5102 arranged on the side surface, a brush 5103, and an operation button 5104. Although not shown, the bottom surface of the cleaning robot 5100 is provided with tires, a suction port, and the like. The cleaning robot 5100 also has various sensors such as an infrared sensor, an ultrasonic sensor, an acceleration sensor, a piezoelectric sensor, an optical sensor, and a gyro sensor. The cleaning robot 5100 also has wireless communication means.

[0232] The cleaning robot 5100 can move by itself, detect dirt 5120, and suck up the dirt from a suction port provided on the bottom surface.

[0233] In addition, the cleaning robot 5100 can analyze the image captured by the camera 5102 and determine the presence or absence of obstacles such as walls, furniture, steps, etc. Furthermore, when an object that may become entangled in the brush 5103, such as a wire, is detected by image analysis, the rotation of the brush 5103 can be stopped.

[0234] The remaining battery level, the amount of sucked up dirt, etc. can be displayed on the display 5101. The route traveled by the cleaning robot 5100 may be displayed on the display 5101. The display 5101 may be a touch panel, and an operation button 5104 may be provided on the display 5101.

[0235] The cleaning robot 5100 can communicate with a portable electronic device 5140 such as a smartphone. Images captured by the camera 5102 can be displayed on the portable electronic device 5140. Therefore, the owner of the cleaning robot 5100 can know the state of the room even when he or she is away from home. Also, the display on the display 5101 can be confirmed on a portable electronic device such as a smartphone.

[0236] The light-emitting device according to one embodiment of the present invention can be used for the display 5101 .

[0237] The robot 2100 shown in FIG. 8(B) includes a computing device 2110, an illuminance sensor 2101, a microphone 2102, an upper camera 2103, a speaker 2104, a display 2105, a lower camera 2106, an obstacle sensor 2107, and a movement mechanism 2108.

[0238] The microphone 2102 has a function of detecting the user's voice, environmental sounds, etc. The speaker 2104 has a function of emitting sound. The robot 2100 can communicate with the user using the microphone 2102 and the speaker 2104.

[0239] The display 2105 has a function of displaying various information. The robot 2100 can display information desired by the user on the display 2105. The display 2105 may be equipped with a touch panel. The display 2105 may also be a removable information terminal, and by installing it in a fixed position on the robot 2100, charging and data transfer are possible.

[0240] The upper camera 2103 and the lower camera 2106 have a function of capturing images of the surroundings of the robot 2100. In addition, the obstacle sensor 2107 can detect the presence or absence of an obstacle in the moving direction when the robot 2100 moves forward using the moving mechanism 2108. The robot 2100 can recognize the surrounding environment and move safely using the upper camera 2103, the lower camera 2106, and the obstacle sensor 2107. The light-emitting device of one embodiment of the present invention can be used for the display 2105.

[0241] 8C is a diagram showing an example of a goggle-type display. The goggle-type display includes, for example, a housing 5000, a display unit 5001, a speaker 5003, an LED lamp 5004, a connection terminal 5006, a sensor 5007 (including a function of measuring force, displacement, position, speed, acceleration, angular velocity, rotation speed, distance, light, liquid, magnetism, temperature, chemical substance, sound, time, hardness, electric field, current, voltage, power, radiation, flow rate, humidity, gradient, vibration, odor, or infrared ray), a microphone 5008, a display unit 5002, a support unit 5012, and earphones 5013.

[0242] The light-emitting device of one embodiment of the present invention can be used for the display portion 5001 and the display portion 5002 .

[0243] 9 shows an example in which the light-emitting element described in Embodiment 2 is used in a desk lamp, which is a lighting device. The desk lamp shown in FIG. 9 includes a housing 2001 and a light source 2002, and the lighting device described in Embodiment 4 may be used as the light source 2002.

[0244] FIG. 10 shows an example in which the light-emitting element described in Embodiment 2 is used as an indoor lighting device 3001. The light-emitting element described in Embodiment 2 has high emission efficiency, and therefore a lighting device with low power consumption can be provided. In addition, the light-emitting element described in Embodiment 2 can be made large in area, and therefore can be used as a large-area lighting device. In addition, the light-emitting element described in Embodiment 2 is thin, and therefore can be used as a thin lighting device.

[0245] The light-emitting element described in Embodiment 2 can also be mounted on a windshield or dashboard of an automobile. FIG 11 shows one mode in which the light-emitting element described in Embodiment 2 is used on a windshield or dashboard of an automobile. Display regions 5200 to 5203 are displays provided using the light-emitting element described in Embodiment 2.

[0246] A display region 5200 and a display region 5201 are a display device equipped with the light-emitting element described in Embodiment 2, which is provided on the windshield of an automobile. The light-emitting element described in Embodiment 2 can be a so-called see-through display device in which the opposite side can be seen through by forming a first electrode and a second electrode using light-transmitting electrodes. If the display is in a see-through state, the display device can be installed on the windshield of an automobile without interfering with visibility. When a transistor for driving is provided, a light-transmitting transistor such as an organic transistor made of an organic semiconductor material or a transistor using an oxide semiconductor is preferably used.

[0247] The display area 5202 is a display device provided in a pillar portion and equipped with the light-emitting element described in Embodiment 2. By displaying an image from an imaging means provided in the vehicle body in the display area 5202, the view blocked by the pillar can be complemented. Similarly, the display area 5203 provided in the dashboard portion can complement the view blocked by the vehicle body by displaying an image from an imaging means provided outside the vehicle, thereby compensating for blind spots and improving safety. By displaying an image to complement the invisible parts, safety can be confirmed more naturally and without discomfort.

[0248] The display area 5203 can also provide various information by displaying navigation information, a speedometer, a tachometer, a mileage, a fuel gauge, a gear state, air conditioner settings, etc. The display items and layout can be changed as appropriate to suit the user's preferences. Note that this information can also be provided in the display areas 5200 to 5202. The display areas 5200 to 5203 can also be used as lighting devices.

[0249] 12A and 12B show a foldable mobile information terminal 5150. The foldable mobile information terminal 5150 has a housing 5151, a display area 5152, and a bending portion 5153. Fig. 12A shows the mobile information terminal 5150 in an unfolded state. Fig. 12B shows the mobile information terminal in a folded state. Although the mobile information terminal 5150 has a large display area 5152, it is compact and highly portable when folded.

[0250] Display area 5152 can be folded in half by bending portion 5153. Bending portion 5153 is composed of an expandable member and multiple support members, and when folding, the expandable member stretches and bending portion 5153 is folded with a radius of curvature of 2 mm or more, preferably 3 mm or more.

[0251] Note that the display region 5152 may be a touch panel (input / output device) equipped with a touch sensor (input device). The light-emitting device of one embodiment of the present invention can be used for the display region 5152.

[0252] 13(A) to 13(C) show a foldable portable information terminal 9310. Fig. 13(A) shows the portable information terminal 9310 in an unfolded state. Fig. 13(B) shows the portable information terminal 9310 in a state in which it is changing from one of the unfolded state and the folded state to the other. Fig. 13(C) shows the portable information terminal 9310 in a folded state. The portable information terminal 9310 has excellent portability in the folded state, and has excellent viewability of the display due to a seamless wide display area in the unfolded state.

[0253] The display panel 9311 is supported by three housings 9315 connected by hinges 9313. Note that the display panel 9311 may be a touch panel (input / output device) equipped with a touch sensor (input device). The display panel 9311 can be reversibly transformed from an unfolded state of the mobile information terminal 9310 to a folded state by bending the two housings 9315 via the hinges 9313. The light-emitting device of one embodiment of the present invention can be used for the display panel 9311. EXAMPLES

[0254] <Synthesis Example 1> In this example, a synthesis method of 4,4'-(1,1-cyclohexane-diyl)bis[N,N-bis(4-cyclohexylbenzene-1-yl)aminobenzene] (abbreviation: TAPC-02), which is an organic compound according to one embodiment of the present invention, is described. The structure of TAPC-02 is shown below.

[0255] [ka]

[0256] <Step 1: Synthesis of 4,4'-(1,1-cyclohexanediyl)bis[N,N-bis(4-cyclohexylbenzene-1-yl)aminobenzene]> In a three-neck flask, 5.3 g (20 mmol) of 1,1-bis(4-aminophenyl)cyclohexane, 21.0 g (88 mmol) of 4-cyclohexyl-1-bromobenzene, 25.4 g (264 mmol) of sodium tert-butoxide, and 400 mL of a xylene mixture were placed, and the flask was degassed under reduced pressure, and then the atmosphere in the flask was replaced with nitrogen. This mixture was heated and stirred to about 50°C. Here, 293 mg (0.8 mmol) of allyl palladium chloride dimer (II) (abbreviation: (AllylPdCl)2) and 1128 mg (3.2 mmol) of di-tert-butyl(1-methyl-2,2-diphenylcyclopropyl)phosphine (trade name: cBRIDP (registered trademark)) were added, and the mixture was heated to reflux for 6 hours. Thereafter, the temperature of the flask was returned to about 60°C, about 4 mL of water was added, and the precipitated solid was filtered and washed with toluene. The filtrate was concentrated, and the resulting xylene solution was purified by silica gel column chromatography. The resulting solution was concentrated to obtain a thick toluene solution. This toluene solution was dropped into ethanol to cause reprecipitation. The precipitate was filtered at about 0°C, and the obtained solid was dried under reduced pressure at about 75°C to obtain 16.5 g of the target white solid in a yield of 92%. The synthesis scheme of step 1 is shown below.

[0257] [ka]

[0258] The white solid obtained in step 1 was analyzed by nuclear magnetic resonance spectroscopy ( 1 The results of the analysis by H-NMR are shown below and in Figure 14. From this, it was found that 4,4'-(1,1-cyclohexane-diyl)bis[N,N-bis(4-cyclohexylbenzene-1-yl)aminobenzene] was synthesized in step 1.

[0259] 1H-NMR.δ(CDCl3):7.02-7.11(m,12H),6.91-7.00(m,12H),2.39-2.47(brm,4H),2.16-2.21(brm,4H),1.78-1.91(br m,16H),1.69-1.76(brm,4H),1.51-1.57(brm,4H),1.45-1.51(brm,2H),1.31-1.42(brm,16H),1.17-1.28(brm,4H).

[0260] Next, 6.0 g of the obtained solid was purified by train sublimation. The sublimation purification was performed by heating at 355°C under conditions of a pressure of 3.0 Pa and an argon flow rate of 12.3 mL / min. After the sublimation purification, 4.5 g of a pale yellowish white solid was obtained with a recovery rate of 74%.

[0261] Next, the absorption and emission spectra of the toluene solution and solid thin film of TAPC-02 were measured. The solid thin film was prepared on a quartz substrate by vacuum deposition. An ultraviolet-visible spectrophotometer (solution: V-550, manufactured by JASCO Corporation; thin film: U-4100, manufactured by Hitachi High-Technologies Corporation) was used to measure the absorption spectrum. The absorption spectrum of the solution was calculated by subtracting the absorption spectrum measured by putting only toluene in a quartz cell, and the absorption spectrum of the thin film was calculated by the absorbance (-log 10 It was calculated from [%T / (100-%R)], where %T is the transmittance and %R is the reflectance. A fluorometer (FS920, manufactured by Hamamatsu Photonics Co., Ltd.) was used to measure the emission spectrum.

[0262] The results of measuring the absorption spectrum and emission spectrum of the obtained toluene solution are shown in Figure 15. The horizontal axis represents wavelength, and the vertical axis represents absorption intensity and emission intensity. The results of measuring the absorption spectrum and emission spectrum of the solid thin film are shown in Figure 16.

[0263] Next, the organic compound, TAPC-02, was subjected to mass (MS) analysis by liquid chromatography mass spectrometry (abbreviated as LC / MS analysis).

[0264] In the LC / MS analysis, LC (liquid chromatography) separation was performed using Waters Acquity UPLC (registered trademark), and MS analysis (mass spectrometry) was performed using Waters Xevo G2 Tof MS. The column used in the LC separation was Acquity UPLC BEH C4 (2.1×100 mm 1.7 μm), and the column temperature was 40° C. The mobile phase A was acetonitrile, and the mobile phase B was 0.1% formic acid aqueous solution. The sample was prepared by dissolving TAPC-02 at an arbitrary concentration in toluene and diluting it with acetonitrile, and the injection amount was 5.0 μL.

[0265] The LC separation was performed so that the ratio of mobile phase A to mobile phase B was mobile phase A:mobile phase B=95:5 from 0 to 10 minutes after the start of the measurement.

[0266] In the MS analysis, ionization was performed by electrospray ionization (ESI). The capillary voltage was 3.0 kV, the sample cone voltage was 30 V, and detection was performed in positive mode. The component with m / z=899 ionized under the above conditions was collided with argon gas in the collision cell and dissociated into product ions. The energy (collision energy) used for collision with argon was 70 eV. The mass range to be measured was m / z (mass-to-charge ratio) = 100 to 1000. Figure 17 shows the results of detecting the dissociated product ions using a time-of-flight (TOF) MS.

[0267] From the results in Figure 17, it was found that for TAPC-02, product ions were mainly detected around m / z = 899. The results shown in Figure 17 are characteristic results attributable to TAPC-02, and therefore can be said to be important data for identifying TAPC-02 contained in a mixture.

[0268] The fragment ion at m / z=566 observed when measuring with a collision energy of 70 eV is presumed to be 4,4'-(1,1-cyclohexane-diyl)[N-bis(4-cyclohexylbenzene-1-yl)aminobenzene][N´-(4-cyclohexylbenzene-1-yl)aminobenzene] generated by cleavage of the C-N bond of TAPC-02, and is one of the characteristics of TAPC-02.

[0269] FIG. 38 shows the refractive index of the synthesized TAPC-02 and that of 1,1-bis-(4-bis(4-methyl-phenyl)-amino-phenyl)-cyclohexane (abbreviation: TAPC), which is known as an organic compound with a small refractive index. The refractive index n includes n Ordinary, which is the refractive index of ordinary rays, n Extra-ordinary, which is the refractive index of extraordinary rays, and n average, which is the average value of both. When simply referring to "refractive index" in this specification, n average may be read as n Ordinary if anisotropic analysis was not performed. The sum of the value obtained by multiplying the value of n Ordinary by two and the value of n Extra-ordinary divided by 3 is n average.

[0270] As shown in FIG. 38, TAPC-02, which is an organic compound according to one embodiment of the present invention, is an organic compound with a very low refractive index.

[0271] Next, the glass transition temperatures (Tg) of TAPC-02 and TAPC were measured using a differential scanning calorimeter (DSC). As a result, the Tg of TAPC-02 was 119°C, and the Tg of TAPC was 85°C. This shows that TAPC-02 exhibits good heat resistance. EXAMPLES

[0272] <Synthesis Example 2> In this example, a synthesis method of 4,4'-(1,1-cyclohexane-diyl)bis{N-(4-cyclohexylphenyl)N-[(4'-cyclohexyl)-1,1'-biphenyl-4-yl]aminobenzene} (abbreviation: TAPC-03), which is an organic compound according to one embodiment of the present invention, is described. The structure of TAPC-03 is shown below.

[0273] [ka]

[0274] <Step 1: Synthesis of 4,4'-(1,1-cyclohexanediyl)bis{N-(4-cyclohexylphenyl)aminobenzene}> In a three-neck flask, 5.3g (20mmol) of 1,1-bis(4-aminophenyl)cyclohexane, 10.0g (42mmol) of 4-cyclohexyl-1-bromobenzene, 12.1g (126mmol) of sodium tert-butoxide, and 200mL of a xylene mixture were placed, and the flask was degassed under reduced pressure, and then replaced with nitrogen. This mixture was heated to about 50°C and stirred. Here, 150mg (0.4mmol) of allyl palladium chloride dimer (II) (abbreviation: (AllylPdCl)2) and 660mg (1.6mmol) of dicyclohexyl(2',6'-dimethoxy-{1,1'-biphenyl}-2-yl)phosphine (abbreviation: SPhos) were added, and the mixture was heated to reflux for 6 hours. Thereafter, the temperature of the flask was returned to about 60°C, about 2mL of water was added, and the precipitated solid was filtered and washed with toluene. The filtrate was concentrated, and the resulting xylene solution was purified by silica gel column chromatography. The resulting solution was concentrated to obtain a thick toluene solution. This toluene solution was dropped into ethanol to cause reprecipitation. The precipitate was filtered at about 0°C, and the obtained solid was dried under reduced pressure at about 75°C to obtain 9.5 g of the target white solid in an 81% yield. The synthesis scheme of step 1 is shown below.

[0275] [ka]

[0276] The white solid obtained in step 1 was analyzed by nuclear magnetic resonance spectroscopy ( 1 The results of the analysis by H-NMR are shown below. 1 The H-NMR chart is shown in Figure 18. This shows that the organic compound 4,4'-(1,1-cyclohexane-diyl)bis{N-(4-cyclohexylphenyl)aminobenzene} was synthesized in step 1.

[0277] 1 H-NMR.δ(CDCl3):7.02-7.11(m,8H),6.91-6.99(m,8H),5.55(br,2H),2.39-2.47(brm,2H),2.16-2.28(brm,4H),1.76-1 .91(brm,8H),1.69-1.76(brm,2H),1.52-1.60(brm,4H),1.44-1.52(brm,2H),1.31-1.44(brm,8H),1.18-1.28(brm,4H).

[0278] <Step 2: Synthesis of 4,4'-(1,1-cyclohexanediyl)bis{N-(4-cyclohexylphenyl)N-[(4'-cyclohexyl)-1,1'-biphenyl-4-yl]aminobenzene} (abbreviation: TAPC-03)> In a three-neck flask, 5.8g (10mmol) of 4,4'-(1,1-cyclohexane-diyl)bis{N-(4-cyclohexylphenyl)aminobenzene}, 5.4g (20mmol) of 4'-cyclohexyl-(1,1'-biphenyl)-4-chlorobenzene, 5.8g (60mmol) of sodium tert-butoxide, and 70mL of a xylene mixture were placed, and the flask was degassed under reduced pressure, and then the atmosphere in the flask was replaced with nitrogen. This mixture was heated and stirred to about 50°C. Here, 73mg (0.2mmol) of allyl palladium chloride dimer (II) (abbreviation: (AllylPdCl)2) and 280mg (0.8mmol) of di-tert-butyl(1-methyl-2,2-diphenylcyclopropyl)phosphine (abbreviation: cBRIDP) were added, and the mixture was heated and refluxed for 8 hours. After that, the temperature of the flask was returned to about 60°C, about 2 mL of water was added, and the precipitated solid was filtered and washed with toluene. The filtrate was concentrated, and the resulting xylene solution was purified by silica gel column chromatography. The resulting solution was concentrated to obtain a thick toluene solution. This toluene solution was dropped into ethanol to cause reprecipitation. The precipitate was filtered at about 0°C, and the obtained solid was dried under reduced pressure at about 75°C, obtaining 5.8 g of the target white solid in a yield of about 100%. The synthesis scheme of step 2 is shown below.

[0279] [ka]

[0280] The white solid obtained in step 2 was analyzed by nuclear magnetic resonance spectroscopy ( 1 The results of the analysis by H-NMR are shown below. 1 The H-NMR chart is shown in Figure 19. This shows that in step 2, the organic compound 4,4'-(1,1-cyclohexane-diyl)bis{N-(4-cyclohexylphenyl)N-[(4'-cyclohexyl)-1,1'-biphenyl-4-yl]aminobenzene} (abbreviation: TAPC-03) was synthesized.

[0281] 1H-NMR.δ(CDCl3):7.46-7.50(m,4H),7.40-7.45(m,4H),7.23-7.26(m,4H),6.99-7.17(brm,20H),2.42-2.59(brm, 4H),2.19-2.25(brm,2H),1.79-1.95(brm,16H),1.70-1.79(brm,4H),1.32-1.64(brm,24H),1.18-1.32(brm,4H). EXAMPLES

[0282] Example 1 In this example, a light-emitting element 1 of one embodiment of the present invention and a comparative light-emitting element 1 will be described. Structural formulas of organic compounds used in the light-emitting element 1 and the comparative light-emitting element 1 are shown below.

[0283] [ka]

[0284] (Method of manufacturing light-emitting element 1) First, indium tin oxide containing silicon oxide (ITSO) was formed by sputtering on a glass substrate to form a first electrode 101. The thickness of the first electrode 101 was 70 nm, and the electrode area was 2 mm×2 mm.

[0285] Next, as a pretreatment for forming a light emitting element on the substrate, the substrate surface was washed with water, baked at 200° C. for 1 hour, and then subjected to UV ozone treatment for 370 seconds.

[0286] Then, 10 -4 The substrate was introduced into a vacuum deposition apparatus whose inside had been reduced in pressure to about Pa, and vacuum baking was carried out at 170° C. for 30 minutes in a heating chamber in the vacuum deposition apparatus, and the substrate was then allowed to cool for about 30 minutes.

[0287] Next, the substrate on which the first electrode 101 was formed was fixed to a substrate holder provided in a vacuum deposition apparatus so that the surface on which the first electrode 101 was formed faced downward. Then, 4,4'-bis(9-carbazole)-2,2'-dimethyl-biphenyl (abbreviation: dmCBP) represented by the above structural formula (i) and molybdenum oxide (VI) were co-deposited on the first electrode 101 by a deposition method using resistance heating to a thickness of 10 nm in a weight ratio of 2:0.5 (=dmCBP:MoOx), thereby forming a hole injection layer 111.

[0288] Next, 4,4'-(1,1-cyclohexanediyl)bis[N,N-bis(4-cyclohexylbenzene-1-yl)aminobenzene] (abbreviation: TAPC-02) represented by the above structural formula (ii) was deposited on the hole injection layer 111 to a thickness of 65 nm, and then N-(1,1'-biphenyl-4-yl)-9,9-dimethyl-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-9H-fluorene-2-amine (abbreviation: PCBBiF) represented by the above structural formula (iii) was deposited to a thickness of 5 nm to form a hole transport layer 112.

[0289] Next, 2-[3'-(dibenzothiophen-4-yl)biphenyl-3-yl]dibenzo[f,h]quinoxaline (abbreviation: 2mDBTBPDBq-II) represented by the above structural formula (iv), PCBBiF, and (acetylacetonato)bis(4,6-diphenylpyrimidinato)iridium(III) (abbreviation: [Ir(dppm)2(acac)]) represented by the above structural formula (v) were co-deposited to a thickness of 20 nm so as to give a weight ratio of 0.7:0.3:0.06 (=2mDBTBPDBq-II:PCBBiF:[Ir(dppm)2(acac)]), and then the light-emitting layer 113 was formed by co-depositing the material to a thickness of 20 nm so as to give a weight ratio of 0.8:0.2:0.06 (=2mDBTBPDBq-II:PCBBiF:[Ir(dppm)2(acac)]).

[0290] Then, 2mDBTBPDBq-II was deposited on the light-emitting layer 113 to a thickness of 10 nm, and then bathophenanthroline (abbreviation: BPhen) represented by the above structural formula (vi) was deposited on the light-emitting layer 113 to a thickness of 5 nm to form the electron transport layer 114.

[0291] After forming the electron transport layer 114, lithium fluoride (LiF) and BPhen were co-evaporated to a thickness of 35 nm so as to have a volume ratio of 0.75:0.25 (=LiF:BPhen) to form the electron injection layer 115, and then aluminum was evaporated to a thickness of 200 nm to form the second electrode 102, thereby producing the light-emitting element 1 of this embodiment.

[0292] (Method of manufacturing comparative light-emitting element 1) Comparative light-emitting element 1 was fabricated in the same manner as light-emitting element 1, except that the layer formed from TAPC-02 in the hole-transport layer 112 of light-emitting element 1 was replaced with 1,1-bis-(4-bis(4-methyl-phenyl)-amino-phenyl)-cyclohexane (abbreviation: TAPC) represented by the above structural formula (vii) and the film thickness was set to 70 nm.

[0293] The device structures of the light-emitting element 1 and the comparative light-emitting element 1 are summarized in the following table.

[0294] [Table 1]

[0295] Light-emitting element 1 and comparative light-emitting element 1 were sealed with a glass substrate in a nitrogen atmosphere glove box so that the light-emitting elements would not be exposed to the atmosphere (a sealant was applied around the elements, and UV treatment was performed during sealing, followed by heat treatment at 80°C for 1 hour), after which the initial characteristics of these light-emitting elements were measured. Note that no special measures were taken for improving the extraction efficiency of the glass substrate on which the light-emitting elements were fabricated.

[0296] The luminance-current density characteristics of the light-emitting element 1 and the comparative light-emitting element 1 are shown in FIG 20, the current efficiency-luminance characteristics are shown in FIG 21, the luminance-voltage characteristics are shown in FIG 22, the current-voltage characteristics are shown in FIG 23, the external quantum efficiency-luminance characteristics are shown in FIG 24, and the emission spectrum is shown in FIG 25. 2 Table 2 shows the main characteristics in the vicinity of the wavelength. A color luminance meter (BM-5A, manufactured by Topcon Corporation) was used to measure the luminance and CIE chromaticity, and a multichannel spectrometer (PMA-11, manufactured by Hamamatsu Photonics KK) was used to measure the emission spectrum. From FIG. 25, it can be seen that the emission spectra of the light-emitting element 1 and the comparative light-emitting element 1 overlap very well, and the optical path formed by the product of the film thickness and the refractive index of the light-emitting element 1 and the comparative light-emitting element 1 are almost the same. From this, it can be said that the comparative light-emitting element 1 and the light-emitting element 1 can be strictly compared. Note that the external quantum efficiency in FIG. 24 shows the value when the Lambertian is assumed, and the external quantum efficiency in the table below adopts the true value obtained by measuring the angle dependency of the emission spectrum and correcting the deviation from the Lambertian distribution.

[0297] [Table 2]

[0298] 20 to 25 and Table 2 show that the light-emitting element 1 of one embodiment of the present invention can be made into a light-emitting element with high emission efficiency by including, in the hole-transport layer, a layer made of TAPC-02, which is an organic compound of one embodiment of the present invention and has a refractive index lower than that of TAPC. EXAMPLES

[0299] In this example, a light-emitting element 2 according to one embodiment of the present invention will be described. The structural formula of an organic compound used in the light-emitting element 2 is shown below.

[0300] [ka]

[0301] (Method of manufacturing light-emitting element 2) First, indium tin oxide containing silicon oxide (ITSO) was formed by sputtering on a glass substrate to form a first electrode 101. The thickness of the first electrode 101 was 70 nm, and the electrode area was 2 mm×2 mm.

[0302] Next, as a pretreatment for forming a light emitting element on the substrate, the substrate surface was washed with water, baked at 200° C. for 1 hour, and then subjected to UV ozone treatment for 370 seconds.

[0303] Then, 10 -4 The substrate was introduced into a vacuum deposition apparatus whose inside had been reduced in pressure to about Pa, and vacuum baking was carried out at 170° C. for 30 minutes in a heating chamber in the vacuum deposition apparatus, and the substrate was then allowed to cool for about 30 minutes.

[0304] Next, the substrate on which the first electrode 101 was formed was fixed to a substrate holder provided in a vacuum deposition apparatus so that the surface on which the first electrode 101 was formed faced downward. Then, 4,4'-(1,1-cyclohexane-diyl)bis[N,N-bis(4-cyclohexylbenzene-1-yl)aminobenzene] (abbreviation: TAPC-02) represented by the above structural formula (ii) and molybdenum oxide (VI) were co-deposited on the first electrode 101 to a thickness of 50 nm by a deposition method using resistance heating so as to have a weight ratio of 2:0.5 (=TAPC-02:molybdenum oxide), and then 4,4'-bis(9-carbazole)-2,2'-dimethyl-biphenyl (abbreviation: dmCBP) represented by the above structural formula (i) and molybdenum oxide (VI) were co-deposited to a thickness of 5 nm so as to have a weight ratio of 2:0.5 (=dmCBP:MoOx) to form a hole injection layer 111.

[0305] Next, 4-phenyl-4′-(9-phenylfluoren-9-yl)triphenylamine (abbreviation: BPAFLP) represented by the above structural formula (viii) was deposited on the hole injection layer 111 to a thickness of 20 nm to form the hole transport layer 112.

[0306] Next, 2-[3'-(dibenzothiophen-4-yl)biphenyl-3-yl]dibenzo[f,h]quinoxaline (abbreviation: 2mDBTBPDBq-II) represented by the above structural formula (iv), N-(1,1'-biphenyl-4-yl)-9,9-dimethyl-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-9H-fluoren-2-amine (abbreviation: PCBBiF) represented by the above structural formula (iii), and (acetylacetamide) represented by the above structural formula (v) were The light-emitting layer 113 was formed by co-evaporating 20 nm of 2mDBTBPDBq-II:PCBBiF:[Ir(dppm)2(acac)] and 2mDBTBPDBq-II:PCBBiF:[Ir(dppm)2(acac)] in a weight ratio of 0.7:0.3:0.06 (=2mDBTBPDBq-II:PCBBiF:[Ir(dppm)2(acac)]).

[0307] Thereafter, 2mDBTBPDBq-II was deposited to a thickness of 10 nm on the light-emitting layer 113, and then bathophenanthroline (abbreviation: BPhen) represented by the above structural formula (vi) was deposited to a thickness of 5 nm to form the electron transport layer 114.

[0308] After forming the electron transport layer 114, lithium fluoride (LiF) and BPhen were co-evaporated to a thickness of 35 nm so as to have a volume ratio of 0.75:0.25 (=LiF:BPhen) to form the electron injection layer 115, and then aluminum was evaporated to a thickness of 200 nm to form the second electrode 102, thereby producing the light-emitting element 2 of this embodiment.

[0309] The device structure of the light-emitting element 2 is summarized in the table below.

[0310] [Table 3]

[0311] The light-emitting element 3 was sealed with a glass substrate in a nitrogen atmosphere glove box so that the light-emitting element would not be exposed to the atmosphere (a sealant was applied around the element, and UV treatment was performed during sealing, followed by heat treatment at 80°C for 1 hour), and then the initial characteristics of the light-emitting element 2 were measured. Note that no special measures were taken for improving the extraction efficiency of the glass substrate on which the light-emitting element was fabricated.

[0312] The luminance-current density characteristics of the light-emitting element 2 are shown in FIG 26, the current efficiency-luminance characteristics in FIG 27, the luminance-voltage characteristics in FIG 28, the current-voltage characteristics in FIG 29, the external quantum efficiency-luminance characteristics in FIG 30, and the emission spectrum in FIG 31. 2 Table 4 shows the main characteristics in the vicinity. The measurement method is the same as in Example 3. The external quantum efficiency in FIG. 30 shows a value assuming a Lambertian distribution, and the external quantum efficiency in the table below adopts a true value obtained by measuring the angle dependency of the emission spectrum and correcting the deviation from the Lambertian distribution.

[0313] [Table 4]

[0314] 26 to 31 and Table 4 show that Light-emitting element 2, which is one embodiment of the present invention, is a yellow-orange light-emitting element with good luminous efficiency. In particular, the external quantum efficiency exceeds 35%. Considering that the limit of the light extraction efficiency of an EL device is considered to be about 30%, it is clear that the external quantum efficiency of this device is extremely high. This is due to the improvement in light extraction efficiency achieved by using TAPC-02, which has a low refractive index. EXAMPLES

[0315] In this example, a light-emitting element 3 according to one embodiment of the present invention will be described. The structural formula of an organic compound used in the light-emitting element 3 is shown below.

[0316] [ka]

[0317] (Method of Manufacturing Light-Emitting Element 3) First, indium tin oxide containing silicon oxide (ITSO) was formed by sputtering on a glass substrate to form a first electrode 101. The thickness of the first electrode 101 was 70 nm, and the electrode area was 2 mm×2 mm.

[0318] Next, as a pretreatment for forming a light emitting element on the substrate, the substrate surface was washed with water, baked at 200° C. for 1 hour, and then subjected to UV ozone treatment for 370 seconds.

[0319] Then, 10 -4 The substrate was introduced into a vacuum deposition apparatus whose inside had been reduced in pressure to about Pa, and vacuum baking was carried out at 170° C. for 30 minutes in a heating chamber in the vacuum deposition apparatus, and the substrate was then allowed to cool for about 30 minutes.

[0320] Next, the substrate on which the first electrode 101 was formed was fixed to a substrate holder provided in a vacuum deposition apparatus so that the surface on which the first electrode 101 was formed faced downward. On the first electrode 101, calcium fluoride (CaF2), 1,1-bis-(4-bis(4-methyl-phenyl)-amino-phenyl)-cyclohexane (abbreviation: TAPC) represented by the above structural formula (vii), and molybdenum oxide (VI) were co-deposited to a thickness of 45 nm by a deposition method using resistance heating so as to have a weight ratio of 3:1:0.5 (=CaF2:TAPC:molybdenum oxide), and then 4,4'-bis(9-carbazole)-2,2'-dimethyl-biphenyl (abbreviation: dmCBP) represented by the above structural formula (i) and molybdenum oxide (VI) were co-deposited to a thickness of 5 nm so as to have a weight ratio of 2:0.5 (=dmCBP:MoOx) to form a hole injection layer 111.

[0321] Next, 4,4'-(1,1-cyclohexanediyl)bis[N,N-bis(4-cyclohexylbenzene-1-yl)aminobenzene] (abbreviation: TAPC-02) represented by the above structural formula (ii) was deposited to a thickness of 15 nm on the hole injection layer 111, and then N-(1,1'-biphenyl-4-yl)-9,9-dimethyl-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-9H-fluorene-2-amine (abbreviation: PCBBiF) represented by the above structural formula (iii) was deposited to a thickness of 5 nm to form a hole transport layer 112.

[0322] Next, 2-[3'-(dibenzothiophene-4-yl)biphenyl-3-yl]dibenzo[f,h]quinoxaline (abbreviation: 2mDBTBPDBq-II) represented by the above structural formula (iv), PCBBiF, and bis{2-[6-(4-cyano-2,6-dimethylphenyl)-4-pyrimidinyl-κN} represented by the above structural formula (ix) were 3 ]phenyl-κC}(2,4-pentanedionato-κO,O')iridium(III) (abbreviation: [Ir(ppm-dmCP)2(acac)]) was co-evaporated to a thickness of 40 nm in a weight ratio of 0.75:0.25:0.05 (=2mDBTBPDBq-II:PCBBiF:[Ir(ppm-dmCP)2(acac)]) to form the light-emitting layer 113.

[0323] Then, 2mDBTBPDBq-II was evaporated to a thickness of 5 nm on the light-emitting layer 113, and then 2,9-bis(naphthalen-2-yl)-4,7-diphenyl-1,10-phenanthroline (abbreviation: NBPhen) represented by the above structural formula (x) was evaporated to a thickness of 5 nm to form the electron transport layer 114.

[0324] After forming the electron transport layer 114, lithium fluoride (LiF) and BPhen were co-evaporated to a thickness of 35 nm so as to have a volume ratio of 0.75:0.25 (=LiF:BPhen) to form the electron injection layer 115, and then aluminum was evaporated to a thickness of 200 nm to form the second electrode 102, thereby producing the light-emitting element 3 of this embodiment.

[0325] The device structure of the light-emitting device 3 is summarized in the table below.

[0326] [Table 5]

[0327] The light-emitting element 3 was sealed with a glass substrate in a nitrogen atmosphere glove box so that the light-emitting element would not be exposed to the atmosphere (a sealant was applied around the element, and UV treatment was performed during sealing, followed by heat treatment at 80°C for 1 hour), and then the initial characteristics of the light-emitting element 3 were measured. Note that no special measures were taken for improving the extraction efficiency of the glass substrate on which the light-emitting element was fabricated.

[0328] The luminance-current density characteristics of the light-emitting element 3 are shown in FIG 32, the current efficiency-luminance characteristics in FIG 33, the luminance-voltage characteristics in FIG 34, the current-voltage characteristics in FIG 35, the external quantum efficiency-luminance characteristics in FIG 36, and the emission spectrum in FIG 37. 2 Table 6 shows the main characteristics in the vicinity. The measurement method is the same as in Example 3. The external quantum efficiency in FIG. 36 shows the value assuming a Lambertian distribution, and the external quantum efficiency in the table below adopts the true value obtained by measuring the angle dependency of the emission spectrum and correcting the deviation from the Lambertian distribution.

[0329] [Table 6]

[0330] 32 to 37 and Table 4 show that the light-emitting element 3 of one embodiment of the present invention is a light-emitting element having very high external quantum efficiency of 42.5%. Therefore, it was found that a light-emitting element with high emission efficiency can be obtained by using the compound of one embodiment of the present invention.

[0331] ≪Reference synthesis example≫ In this reference synthesis example, bis{2-[6-(4-cyano-2,6-dimethylphenyl)-4-pyrimidinyl-κN3 This article describes a method for synthesizing phenyl-κC}(2,4-pentanedionato-κO,O')iridium(III) (abbreviation: [Ir(ppm-dmCP)2(acac)]). The structure of [Ir(ppm-dmCP)2(acac)] is shown below.

[0332] [ka]

[0333] <Step 1: Synthesis of 3,5-dimethyl-4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)benzonitrile> 10.06g of 4-bromo-3,5-dimethylbenzonitrile, 18.35g of bis(pinacolato)diboron, 21.73g of potassium acetate, and 240mL of dimethyl sulfoxide were placed in a three-neck flask equipped with a reflux condenser, and the inside of the flask was replaced with nitrogen. After degassing by stirring the inside of the flask under reduced pressure, 0.59g of [1,1'-bis(diphenylphosphino)ferrocene]palladium(II) dichloride dichloromethane adduct (abbreviation: Pd(dppf)Cl2·CH2Cl2) and 0.59g of 2-dicyclohexylphosphino-2',6'-dimethoxybiphenyl (abbreviation: S-Phos) were added, and the mixture was stirred at 100°C for 32.5 hours. After a certain time had passed, extraction with toluene was performed. The mixture was then purified by silica gel column chromatography using hexane:ethyl acetate = 10:1 as a developing solvent, and the target product was obtained (white solid, yield 5.89g, 48%). The synthetic scheme of step 1 is shown in formula (a-1) below.

[0334] [ka]

[0335] <Step 2: Synthesis of 4-(4-cyano-2,6-dimethylphenyl)-6-phenylpyrimidine (abbreviation: Hppm-dmCP)> Next, 0.74 g of 4-chloro-6-phenylpyrimidine, 1.28 g of 3,5-dimethyl-4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)benzonitrile obtained in step 1 above, 3.23 g of tripotassium phosphate, 43 mL of toluene, and 4.3 mL of water were placed in a three-necked flask equipped with a reflux condenser, and the inside was replaced with nitrogen. After stirring and degassing the inside of the flask under reduced pressure, 0.094 g of tris(dibenzylideneacetone)dipalladium(0) (abbreviation: Pd2(dba)3) and 0.19 g of tris(2,6-dimethoxyphenyl)phosphine (abbreviation: P(2,6-MeOPh)3) were added, and the mixture was stirred at 110°C for 23 hours. After a predetermined time had passed, extraction with toluene was performed. The product was then purified by silica gel column chromatography using hexane:ethyl acetate=5:1 as a developing solvent to obtain the desired pyrimidine derivative, Hppm-dmCP (white solid, yield 0.97 g, 88%). The synthesis scheme of step 2 is shown in the following formula (a-2).

[0336] [ka]

[0337] <Step 3: Di-μ-chloro-tetrakis{2-[6-(4-cyano-2,6-dimethylphenyl)-4-pyrimidinyl-κN 3 Synthesis of phenyl-κC}diiridium(III) (abbreviation: [Ir(ppm-dmCP)2Cl]2) Next, 15 mL of 2-ethoxyethanol, 5 mL of water, 1.60 g of Hppm-dmCP obtained in step 2 above, and 0.81 g of iridium chloride hydrate (IrCl3·H2O) (Furuya Metal Co., Ltd.) were placed in a recovery flask equipped with a reflux tube, and the atmosphere in the flask was replaced with argon. After that, the mixture was irradiated with microwaves (2.45 GHz, 100 W) for 3 hours to cause a reaction. After a certain time had passed, the residue obtained was suction filtered and washed with methanol to obtain the binuclear complex [Ir(ppm-dmCP)2Cl]2 (orange solid, yield 1.45 g, 67%). The synthesis scheme of step 3 is shown in the following formula (a-3).

[0338] [ka]

[0339] <Step 4: Synthesis of [Ir(ppm-dmCP)2(acac)]> 20 mL of 2-ethoxyethanol, 1.44 g of the binuclear complex obtained in step 3 above, [Ir(ppm-dmCP)2Cl]2, 0.41 g of acetylacetone (abbreviation: Hacac), and 0.93 g of sodium carbonate were placed in a recovery flask equipped with a reflux tube, and the atmosphere in the flask was replaced with argon. Then, microwaves (2.45 GHz, 100 W) were irradiated for 4 hours. The residue obtained was suction filtered with dichloromethane, and the filtrate was concentrated. The obtained solid was purified by silica gel column chromatography using hexane:ethyl acetate = 2:1 as a developing solvent, and then recrystallized with a mixed solvent of dichloromethane and methanol to obtain an organometallic complex, [Ir(ppm-dmCP)2(acac)], as a yellow-orange powder (yield 0.19 g, 7%). 0.19 g of the obtained yellow-orange powder was purified by sublimation using a train sublimation method. The conditions for the sublimation purification were heating the solid at 355°C under a pressure of 2.7 Pa and argon gas at a flow rate of 11 mL / min. After the sublimation purification, the target yellow-orange solid was obtained in an amount of 0.092 g and a yield of 48%. The synthesis scheme of step 4 is shown in the following formula (a-4).

[0340] [ka]

[0341] Nuclear magnetic resonance spectroscopy of the yellow-orange solid obtained in step 4 above ( 1 The results of the analysis by H-NMR are shown below. From these results, it was found that [Ir(ppm-dmCP)2(acac)] was obtained in this synthesis example.

[0342] 1H-NMR.δ(CDCl3):1.86(s,6H),2.29(s,12H),5.36(s,1H),6.44(d,2H),6.8 6(t,2H),6.91(t,2H),7.52(s,4H),7.66(d,2H),7.68(s,2H),9.25(s,2H). [Explanation of symbols]

[0343] 101: first electrode, 102: second electrode, 103: EL layer, 111: hole injection 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, 400: substrate, 401: first electrode, 403: EL layer, 404: second electrode, 405: sealing material, 406: sealing material, 407: sealing substrate, 412: pad, 420: IC chip, 501: anode, 502: cathode, 511: first light emitting unit, 512: second light emitting unit, 513: charge generation layer , 601: driver circuit section (source line driver circuit), 602: pixel section, 603: driver circuit section (gate line driver circuit), 604: sealing substrate, 605: sealant, 607: space, 608: wiring, 609: FPC (flexible printed circuit), 610: element substrate, 611: switching FET, 612: current control FET, 613: first electrode, 614: insulator, 616: EL layer, 617: second electrode, 618: light emitting element, 951: substrate, 952: electrode, 953: insulating layer, 954: partition layer, 955: EL layer, 956: electrode, 1001: substrate, 1002: base insulation film, 1003: gate insulating film, 1006: gate electrode, 1007: gate electrode, 1008: gate electrode, 1020: first interlayer insulating film, 1021: second interlayer insulating film, 1022: electrode, 1024W: first electrode, 1024R: first electrode, 1024G: first electrode, 1024B: first electrode, 1025: partition wall, 1028: EL layer, 1029: second electrode, 1031: sealing substrate, 1032: sealing material, 1033: transparent base material, 1034R: red colored layer, 1034G: green colored layer, 1034B: blue colored layer, 1035: black matrix, 1037: second 3 interlayer insulating film, 1040: pixel section, 1041: driving circuit section, 1042: peripheral section, 2001: housing, 2002: light source, 2100: robot, 2110: computing device, 2101: illuminance sensor, 2102: microphone, 2103: upper camera, 2104: speaker, 2105: display, 2106: lower camera, 2107: obstacle sensor, 2108: moving mechanism, 3001: lighting device, 5000: housing, 5001: display section, 5002: display section, 5003: speaker, 5004: LED lamp, 5005: operation key, 5006: connection terminal, 5007: sensor,5008: microphone, 5012: support, 5013: earphone, 5100: cleaning robot, 5101: display, 5102: camera, 5103: brush, 5104: operation button, 5150: mobile information terminal, 5151: housing, 5152: display area, 5153: bending part, 5120: dust, 5200: display area, 5201: display area, 5202: display area, 5203: display area, 7101: housing, 7103: display unit, 7105: stand, 7107: display unit, 7 109: operation keys, 7110: remote control, 7201: main body, 7202: housing, 7203: display unit, 7204: keyboard, 7205: external connection port, 7206: pointing device, 7210: second display unit, 7401: housing, 7402: display unit, 7403: operation buttons, 7404: external connection port, 7405: speaker, 7406: microphone, 9310: mobile information terminal, 9311: display panel, 9312: display area, 9313: hinge, 9315: housing,

Claims

1. A light-emitting element having an organic compound represented by the following general formula (G1): 【Chemistry 1】 (However, in the above general formula (G1), Ar １ ~Ar ４ R each independently represents a substituted or unsubstituted phenylene group, a substituted or unsubstituted biphenyldiyl group, or a substituted or unsubstituted triphenyldiyl group. １ ~R ４ each independently represents an unsubstituted cyclic saturated hydrocarbon group having 5 to 12 carbon atoms; m, n, p, and s each independently represent an integer of 0 to 3, provided that any two or more of m, n, p, and s each independently represent an integer of 1 to 3.

2. A light-emitting element having an organic compound represented by the following general formula (G1): 【Chemistry 2】 (In the above general formula (G1), Ar 1 and Ar 4 each independently represent a substituted or unsubstituted phenylene group, a substituted or unsubstituted biphenyldiyl group, or a substituted or unsubstituted triphenyldiyl group. Ar 2 and Ar 3 each independently represent a substituted or unsubstituted biphenyldiyl group. R １ ~R ４ each independently represents a saturated hydrocarbon group having 5 to 12 carbon atoms or a substituted or unsubstituted cyclic saturated hydrocarbon group having 5 to 12 carbon atoms. m, n, p, and s each independently represent an integer of 0 to 3, provided that any two or more of m, n, p, and s each independently represent an integer of 1 to 3.

3. In claim 1 or 2, Ar １ and Ar ４ each independently represents a substituted or unsubstituted phenylene group.

4. A light-emitting element having an organic compound represented by the following general formula (G2): 【Chemistry 3】 (However, in the above general formula (G2), R １ ~R ４ each independently represents an unsubstituted cyclic saturated hydrocarbon group having 5 to 12 carbon atoms; m, n, p, and s each independently represent an integer of 0 to 3, provided that any two or more of m, n, p, and s each independently represent an integer of 1 to 3.

5. A light-emitting element having an organic compound represented by the following general formula (G4): 【Chemistry 4】 (However, in the above general formula (G4), R １ ~R ４ each independently represents a saturated hydrocarbon group having 5 to 12 carbon atoms or a substituted or unsubstituted cyclic saturated hydrocarbon group having 5 to 12 carbon atoms. m, n, p, and s each independently represent an integer of 0 to 3, provided that any two or more of m, n, p, and s each independently represent an integer of 1 to 3.

6. A light-emitting element having an organic compound represented by the following general formula (G5): 【Chemistry 5】 (However, in the above general formula (G5), R １ ~R ４ each independently represents a saturated hydrocarbon group having 5 to 12 carbon atoms or a substituted or unsubstituted cyclic saturated hydrocarbon group having 5 to 12 carbon atoms. m, n, p, and s each independently represent an integer of 0 to 3, provided that any two or more of m, n, p, and s each independently represent an integer of 1 to 3.

7. In any one of claims 1 to 6, m, n, p and s each independently represent an integer of 1 to 3.

8. In any one of claims 1 to 7, A light-emitting element, wherein m, n, p and s are 1.

9. A light-emitting element having an organic compound represented by the following general formula (G3): 【Chemistry 6】 (However, in the above general formula (G3), R １ ~R ４ each independently represents an unsubstituted cyclic saturated hydrocarbon group having 5 to 12 carbon atoms.

10. A light-emitting element having an organic compound represented by the following general formula (G6): 【Chemistry 7】 (However, in the above general formula (G6), R １ ~R ４ each independently represents a saturated hydrocarbon group having 5 to 12 carbon atoms or a substituted or unsubstituted cyclic saturated hydrocarbon group having 5 to 12 carbon atoms.

11. In any one of claims 1 to 10, R １ ~R ４ each independently is a cyclohexyl group.

12. A light-emitting device having an organic compound represented by the following structural formula: 【Chemistry 8】

13. A light-emitting device having an organic compound represented by the following structural formula: 【Chemistry 9】

14. A light-emitting element comprising the organic compound according to claim 1 between a pair of electrodes.

15. At least a light-emitting layer and a hole-transporting layer are provided between a pair of electrodes, A light-emitting device, wherein the hole transport layer comprises the organic compound according to claim 1 .

16. At least a light-emitting layer and a hole-injection layer are provided between a pair of electrodes, A light-emitting device, wherein the hole injection layer comprises the organic compound according to claim 1 .

17. At least a light-emitting layer, a hole-transporting layer, and a hole-injecting layer are provided between a pair of electrodes; A light-emitting element comprising the organic compound according to claim 1 in the hole transport layer and the hole injection layer.

18. A light-emitting device comprising: the light-emitting element according to claim 14; and a transistor or a substrate.

19. A light emitting device according to claim 18, a sensor, an operation button, a speaker, or a microphone; An electronic device having the

20. A lighting device comprising the light-emitting device according to claim 18 and a housing.

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