Organic Compounds and Light Emitting Devices

Abstract

To provide a novel organic compound which is a material for an electron transport layer and a host material for a phosphorescent-light emitting device.SOLUTION: An organic compound is represented by formula (G1) (A represents a substituent having a hole transporting skeleton, L1 represents a single bond, a substituted or unsubstituted phenylene group or the like, R1 and R2 respectively independently represent any one of hydrogen and a 1-6C alkyl group, Any one of Ar1 to Ar4 is a group represented by formula (g1) and the other groups respectively independently represent any one of hydrogen and a 1-6C alkyl group. In formula (g1), B represents any one of a substituted or unsubstituted carbazolyl group, a dibenzofuranyl group, a dibenzothiophenyl group, and a triphenylenyl group, and L2 represents a substituted or unsubstituted phenylene group or the like).SELECTED DRAWING: None

Description

[Technical field]

[0001] An embodiment of the present invention relates to an organic compound, a light-emitting element, a light-emitting device, a display module, a lighting module, a display device, a light-emitting device, an electronic device, and a lighting device. Note that an embodiment of the present invention is not limited to the above technical field. A 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 devices (organic EL devices) that utilize the electroluminescence (EL) of organic compounds are becoming more and more practical. The basic structure of these light-emitting devices 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 device to inject carriers and utilizing the recombination energy of the carriers, light can be emitted from the light-emitting material.

[0003] Since such light-emitting devices 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 devices is that they can be made thin and lightweight. Another characteristic is that they have an extremely fast response speed.

[0004] In addition, these light-emitting devices can have a two-dimensional light-emitting layer that can be continuously formed, resulting in surface light emission. 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 valuable as surface light sources for lighting applications.

[0005] As such, displays and lighting devices using organic EL devices can be used in a variety of electronic devices, and research and development is ongoing to find devices with better characteristics. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] International Publication No. 2015 / 186882 Brochure [Patent Document 2] International Publication No. 2013 / 180376 Brochure Summary of the Invention [Problem to be solved by the invention]

[0007] An object of one embodiment of the present invention is to provide a novel organic compound, a novel material for an electron transport layer, or a novel host material for a phosphorescent light-emitting device.

[0008] Another object of another embodiment of the present invention is to provide a light-emitting device with high emission efficiency, or a light-emitting device, a light-emitting apparatus, an electronic device, and a display device with low power consumption.

[0009] Note that the description of these objects does not preclude the existence of other objects. Note that one embodiment of the present invention does not necessarily have all of these objects. Note that objects other than these objects will become apparent from the description of the specification, drawings, claims, etc., and objects other than these objects can be extracted from the description of the specification, drawings, claims, etc.

[0010] It is sufficient for the present invention to solve any one of the above problems. [Means for solving the problem]

[0011] One embodiment of the present invention is an organic compound represented by the following general formula (G1).

[0012] [ka]

[0013] In the above general formula (G1), A represents a substituent having a hole-transporting skeleton, L 1 represents a single bond, a substituted or unsubstituted phenylene group, or a substituted or unsubstituted biphenyldiyl group. 1 and R 2 each independently represents any one of hydrogen and an alkyl group having 1 to 6 carbon atoms; Ar 1 ~Ar 4 any one of which is a group represented by the following general formula (g1), and the rest each independently represent any one of hydrogen and an alkyl group having 1 to 6 carbon atoms.

[0014] [ka]

[0015] In the above general formula (g1), B represents any one of a substituted or unsubstituted carbazolyl group, a substituted or unsubstituted dibenzofuranyl group, a substituted or unsubstituted dibenzothiophenyl group, and a substituted or unsubstituted triphenylenyl group; L 2represents a substituted or unsubstituted phenylene group or a substituted or unsubstituted biphenyldiyl group.

[0016] Another embodiment of the present invention is an organic compound having the above structure, in which A is any one of a substituted or unsubstituted carbazolyl group, a substituted or unsubstituted dibenzofuranyl group, and a substituted or unsubstituted dibenzothiophenyl group.

[0017] Another embodiment of the present invention is an organic compound having the above structure, in which A is a substituted or unsubstituted dibenzothiophenyl group.

[0018] Another embodiment of the present invention is an organic compound having the above structure, in which B is a substituted or unsubstituted dibenzothiophenyl group.

[0019] Alternatively, another aspect of the present invention is the above-mentioned Ar 3 is an organic compound represented by the general formula (g1).

[0020] Alternatively, another embodiment of the present invention is a method for manufacturing the above-mentioned 1 , Ar 2 and Ar 4 is an organic compound in which

[0021] Alternatively, another aspect of the present invention is the above-mentioned configuration, 1 is an organic compound in which the phenylene group is unsubstituted.

[0022] Alternatively, in another aspect of the present invention, in the above configuration, the L 1 is an organic compound in which the m-phenylene group is

[0023] Alternatively, another aspect of the present invention is the above-mentioned configuration, 2 is an organic compound in which the phenylene group is unsubstituted.

[0024] Alternatively, another aspect of the present invention is the above-mentioned configuration, 2is an organic compound in which the m-phenylene group is present.

[0025] Alternatively, another aspect of the present invention is the above-mentioned structure, 1 and R 2 is an organic compound in which

[0026] Another embodiment of the present invention is an organic compound represented by the following structural formula (100):

[0027] [ka]

[0028] Another embodiment of the present invention is a light-emitting device using any of the above organic compounds.

[0029] Another embodiment of the present invention is an electronic device including any of the above light-emitting devices and a sensor, an operation button, a speaker, or a microphone.

[0030] Another embodiment of the present invention is a light-emitting device including the above-described light-emitting device and a transistor or a substrate.

[0031] Another embodiment of the present invention is a lighting device including the above-described light-emitting device and a housing.

[0032] In this specification, the term "light-emitting device" includes an image display device using a light-emitting device. The term "light-emitting 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 device, a module in which a printed wiring board is provided at the end of a TCP, or a module in which an IC (integrated circuit) is directly mounted on a light-emitting device by a COG (Chip On Glass) method. Furthermore, lighting fixtures and the like may have a light-emitting device. Effect of the Invention

[0033] In one aspect of the present invention, a novel organic compound can be provided. In one aspect of the present invention, a novel material for an electron transport layer can be provided. Or, in one aspect of the present invention, a novel host material for a phosphorescent light-emitting device can be provided.

[0034] According to another embodiment of the present invention, a light-emitting device with high emission efficiency can be provided. According to another embodiment of the present invention, a light-emitting device, a light-emitting device, an electronic device, a display device, and an electronic device with low power consumption can be provided.

[0035] 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]

[0036] [Figure 1] 1(A), 1(B) and 1(C) are schematic diagrams of light emitting devices. [Diagram 2] 2(A) and 2(B) are conceptual diagrams of an active matrix type light emitting device. [Diagram 3] 3(A) and 3(B) are conceptual diagrams of an active matrix type light emitting device. [Figure 4] FIG. 4 is a conceptual diagram of an active matrix type light emitting device. [Diagram 5] 5(A) and 5(B) are conceptual diagrams of a passive matrix type light emitting device. [Figure 6] 6(A) and 6(B) are diagrams showing a lighting device. [Figure 7] 7(A), 7(B1), 7(B2) and 7(C) are diagrams showing electronic devices. [Figure 8] 8(A), 8(B) and 8(C) are diagrams showing electronic devices. [Figure 9] FIG. 9 is a diagram showing a lighting device. [Figure 10] FIG. 10 is a diagram showing a lighting device. [Figure 11] FIG. 11 is a diagram showing an in-vehicle display device and a lighting device. [Figure 12] 12(A) and 12(B) are diagrams showing electronic devices. [Figure 13] 13(A), 13(B) and 13(C) are diagrams showing electronic devices. [Figure 14] Figure 14 is the 1H NMR chart of 4,8mDBtP2Bqn. [Figure 15] Figure 15 shows the absorption and emission spectra of 4,8mDBtP2Bqn in a toluene solution. [Figure 16] Figure 16 shows the absorption and emission spectra of 4,8mDBtP2Bqn in a thin film state. [Figure 17] FIG. 17 shows the luminance-current density characteristics of the light-emitting device 1. [Figure 18] FIG. 18 shows the current efficiency-luminance characteristics of the light-emitting device 1. [Figure 19] FIG. 19 shows the luminance-voltage characteristics of the light-emitting device 1. [Figure 20] FIG. 20 shows the current-voltage characteristics of the light-emitting device 1. [Figure 21] FIG. 21 shows the external quantum efficiency vs. luminance characteristics of the light-emitting device 1. [Figure 22] FIG. 22 shows the emission spectrum of the light-emitting device 1. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0037] 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.

[0038] (Embodiment 1) In this embodiment, an organic compound of one embodiment of the present invention will be described.

[0039] An organic compound according to one embodiment of the present invention is represented by the following general formula (G1).

[0040] [ka]

[0041] In the above general formula (G1), A represents a substituent having a hole-transporting skeleton, and the substituent having a hole-transporting skeleton is preferably any one of a substituted or unsubstituted carbazolyl group, a substituted or unsubstituted dibenzofuranyl group, and a substituted or unsubstituted dibenzothiophenyl group, and in particular, a substituted or unsubstituted dibenzothiophenyl group is preferred. In addition, the carbazolyl group is at the 9th position, the dibenzofuranyl group is at the 4th position, and the dibenzothiophenyl group is at the 4th position. 1 It is preferable to bond to the above because the HOMO level becomes deeper and the hole resistance is improved. The benzene skeleton in the substituted or unsubstituted carbazolyl group, the substituted or unsubstituted dibenzofuranyl group, or the substituted or unsubstituted dibenzothiophenyl group may be condensed to a naphthalene skeleton.

[0042] L 1 represents a single bond, a substituted or unsubstituted phenylene group, or a substituted or unsubstituted biphenyldiyl group. 1 is preferably a substituted or unsubstituted phenylene group, and more preferably an unsubstituted phenylene group. In addition, when the phenylene group is an m-phenylene group, the organic compound represented by the above general formula (G1) can maintain an appropriate T1 level, which is even more preferable.

[0043] Also, R 1 and R 2each independently represents any one of hydrogen and an alkyl group having 1 to 6 carbon atoms; R 1 and R 2 is preferably hydrogen, since the organic compound represented by the above general formula (G1) can maintain an appropriate T1 level.

[0044] Also, Ar 1 ~Ar 4 Any one of them is a group represented by the following general formula (g1), and the remaining ones each independently represent any one of hydrogen and an alkyl group having 1 to 6 carbon atoms. 2 or Ar 3 In this case, the organic compound represented by the general formula (G1) can maintain an appropriate T1 level, and Ar 1 and Ar 4 is more preferably hydrogen for the same reason.

[0045] [ka]

[0046] In the above general formula (g1), B represents any one of a substituted or unsubstituted carbazolyl group, a substituted or unsubstituted dibenzofuranyl group, a substituted or unsubstituted dibenzothiophenyl group, and a substituted or unsubstituted triphenylenyl group. The substituted or unsubstituted dibenzothiophenyl group is preferable because it has a deep HOMO level and improves the hole resistance of the organic compound represented by the above general formula (G1), and the unsubstituted dibenzothiophenyl group is more preferable. Note that the carbazolyl group is at the 9th position, the dibenzofuranyl group is at the 4th position, the dibenzothiophenyl group is at the 4th position, and the triphenylenyl group is at the 2nd position. 2 is preferable because it has a deep HOMO level and improves the hole resistance of the organic compound represented by the general formula (G1). The benzene skeleton contained in the carbazolyl group, dibenzofuranyl group, or dibenzothiophenyl group may be condensed to a naphthalene skeleton.

[0047] Also, L2 represents a substituted or unsubstituted phenylene group or a substituted or unsubstituted biphenyldiyl group, and is preferably a substituted or unsubstituted phenylene group because it improves sublimability, and more preferably an unsubstituted phenylene group. In addition, it is even more preferable that the phenylene group is an m-phenylene group because the organic compound represented by the above general formula (G1) can maintain an appropriate T1 level.

[0048] In addition, in this specification, when it is stated that a group has a substituent, "substituted or unsubstituted" or "substituted or unsubstituted", the substituent is assumed to be an alkyl group having 1 to 6 carbon atoms or a phenyl group.

[0049] Furthermore, in this specification, when an alkyl group having 1 to 6 carbon atoms is mentioned, specific examples of the alkyl group include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a sec-butyl group, an isobutyl group, a tert-butyl group, a pentyl group, an isopentyl group, a sec-pentyl group, a tert-pentyl group, a neopentyl group, a hexyl group, an isohexyl group, a sec-hexyl group, a tert-hexyl group, a neohexyl group, and a cyclohexyl group.

[0050] The organic compound of one embodiment of the present invention having the above structure has a high T1 level. In addition, the organic compound having the above structure can be suitably used as a host material in an light-emitting layer of a light-emitting device. In particular, the organic compound of one embodiment of the present invention has a high T1 level and can therefore be suitably used as a host material in a phosphorescent light-emitting device.

[0051] Specific examples of organic compounds having the above structure are shown below.

[0052] [ka]

[0053] [ka]

[0054] [ka]

[0055] [ka]

[0056] Next, a method for synthesizing an organic compound according to one embodiment of the present invention will be described using an organic compound represented by the following general formula (G1') as an example. The organic compound represented by the following general formula (G1') is an organic compound according to one embodiment of the present invention.

[0057] [ka]

[0058] The general formula (G1') is obtained by reacting a halogen compound (A1) having a benzo[h]quinazoline skeleton, a boronic acid compound (A2) having a skeleton (A) with hole transport properties, and a boronic acid compound (A3) having a group represented by B (any one of a substituted or unsubstituted carbazolyl group, a substituted or unsubstituted dibenzofuranyl group, a substituted or unsubstituted dibenzothiophenyl group, and a substituted or unsubstituted triphenylenyl group). The synthesis scheme is shown below.

[0059] [ka]

[0060] In the above synthesis scheme, A represents a substituent having a skeleton with hole transport properties, L 1 represents a single bond, a substituted or unsubstituted phenylene group, or a substituted or unsubstituted biphenyldiyl group. 1 and R 2each independently represents any one of hydrogen and an alkyl group having 1 to 6 carbon atoms; B represents any one of a substituted or unsubstituted carbazolyl group, a substituted or unsubstituted dibenzofuranyl group, a substituted or unsubstituted dibenzothiophenyl group, and a substituted or unsubstituted triphenylenyl group; L 2 represents a substituted or unsubstituted phenylene group or a substituted or unsubstituted biphenyldiyl group. 1 and X 2 Each independently represents a halogen element, and preferably represents chlorine, bromine or iodine. 1 and Y 2 each independently represents a boronic acid, a boronic acid ester, a cyclic triol borate salt, etc. As the cyclic triol borate salt, a lithium salt, a potassium salt, or a sodium salt can be used.

[0061] Alternatively, the organic compound represented by the above general formula (G1') may be prepared by reacting a halogen compound (A1) having a benzo[h]quinazoline skeleton with a phenylboronic acid or a biphenylboronic acid compound (B1) substituted with a halogen and a phenylboronic acid or a biphenylboronic acid compound (B2) substituted with a halogen to obtain an intermediate (B3), which is then reacted with a boronic acid compound (B4) having a skeleton (A) with hole transport properties and a boronic acid compound (B5) having a group represented by B (any one of a substituted or unsubstituted carbazolyl group, a substituted or unsubstituted dibenzofuranyl group, a substituted or unsubstituted dibenzothiophenyl group, and a substituted or unsubstituted triphenylenyl group), as shown in the following synthesis scheme.

[0062] [ka]

[0063] In the above synthesis scheme, A represents a substituent having a hole-transporting skeleton, L 1 represents a single bond, a substituted or unsubstituted phenylene group, or a substituted or unsubstituted biphenyldiyl group. 1 and R2 each independently represents any one of hydrogen and an alkyl group having 1 to 6 carbon atoms; B represents any one of a substituted or unsubstituted carbazolyl group, a substituted or unsubstituted dibenzofuranyl group, a substituted or unsubstituted dibenzothiophenyl group, and a substituted or unsubstituted triphenylenyl group; L 2 represents a substituted or unsubstituted phenylene group or a substituted or unsubstituted biphenyldiyl group. 1 ~X 4 Each independently represents a halogen element, and preferably represents chlorine, bromine or iodine. 1 or Y 4 each independently represents a boronic acid, a boronic acid ester, a cyclic triol borate salt, etc. As the cyclic triol borate salt, a lithium salt, a potassium salt, a sodium salt, etc. may be used.

[0064] In the above two synthetic schemes, various types of the compounds (A1), (A2), (A3), (B1), (B2), (B3), (B4), and (B5) are commercially available or can be synthesized, so that many types of the organic compounds represented by the general formula (G1') can be synthesized. Thus, the organic compound of one embodiment of the present invention has a feature of being rich in variation.

[0065] Although an example of a method for synthesizing an organic compound according to one embodiment of the present invention has been described above, the present invention is not limited to this example, and any other synthesis method may be used for synthesis.

[0066] (Embodiment 2) In this embodiment, a light-emitting device according to one embodiment of the present invention will be described.

[0067] 1A illustrates a light-emitting device according to one embodiment of the present invention. The light-emitting device according to one embodiment of the present invention includes a first electrode 101, a second electrode 102, and an EL layer 103. The EL layer 103 includes the organic compound described in Embodiment 1.

[0068] The EL layer 103 has a light-emitting layer 113, and the light-emitting layer 113 contains a light-emitting material. The organic compound described in the embodiment 1 is preferably used as a material for dispersing the light-emitting material in the light-emitting layer 113. Note that the light-emitting layer 113 may contain other materials.

[0069] In addition, the light-emitting layer 113 may have a structure in which the organic compound described in Embodiment 1 and a hole-transporting material are co-evaporated. In this case, the organic compound described in Embodiment 1 and the hole-transporting material may form an exciplex. By forming an exciplex having an appropriate emission wavelength, effective energy transfer to the light-emitting material can be realized, and a light-emitting device with high efficiency and good lifetime can be provided.

[0070] 1A, in addition to the light-emitting layer 113, the EL layer 103 includes a hole injection layer 111, a hole transport layer 112, an electron transport layer 114, and an electron injection layer 115, but the configuration of the light-emitting device is not limited to these. Any of these layers may not be formed, or a layer having another function may be included.

[0071] The organic compound described in Embodiment 1 is also effectively used for the electron-transporting layer 114 since it has a favorable electron-transporting property.

[0072] Next, examples of the detailed structure and materials of the above-mentioned light-emitting device will be described. As described above, the light-emitting device according to 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 the first embodiment.

[0073] 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.

[0074] 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, a light-emitting 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 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.

[0075] 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.

[0076] As the substance having acceptor properties, a compound having an electron-withdrawing group (a halogen group or a cyano group) can be used, and examples thereof include 7,7,8,8-tetracyano-2,3,5,6-tetrafluoroquinodimethane (abbreviation: F4-TCNQ), chloranil, 2,3,6,7,10,11-hexacyano-1,4,5,8,9,12-hexaazatriphenylene (abbreviation: HAT-CN), 1,3,4,5,7,8-hexafluorotetracyano-naphthoquinodimethane (abbreviation: F6-TCNNQ), 2-(7-dicyanomethylene-1,3,4,5,6,8,9,10-octafluoro-7H-pyren-2-ylidene)malononitrile, and the like. In particular, compounds in which an electron-withdrawing group is bonded to a condensed aromatic ring having multiple heteroatoms, such as HAT-CN, are thermally stable and preferred. Radialene derivatives having an electron-withdrawing group (especially a halogen group such as a fluoro group or a cyano group) [3] are preferred because they have a very high electron-accepting property, and specific examples thereof 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]. As the substance having acceptor properties, in addition to the organic compounds described above, molybdenum oxide, vanadium oxide, ruthenium oxide, tungsten oxide, manganese oxide, etc. can be used. In addition, the hole injection layer 111 can be formed by 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), etc.A substance having acceptor properties can extract electrons from an adjacent hole transport layer (or hole transport material) when an electric field is applied.

[0077] A composite material in which the above-mentioned acceptor substance is contained in a material having a hole transport property can also be used as the hole injection layer 111. Note that by using a composite material in which the acceptor substance is contained in a material having a hole transport property, a material for forming an electrode can be selected regardless of the work function. That is, not only a material with a high work function but also a material with a low work function can be used as the first electrode 101.

[0078] As a material having a hole transport property 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. Note that as a material having a hole transport property used in the composite material, a 1×10 -6 cm 2 A material having a hole mobility of 100 / Vs or more is preferable. Specific examples of organic compounds that can be used as a material having a hole transport property in a composite material are listed below.

[0079] 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), and 1,3,5-tris[N-(4-diphenylaminophenyl)-N-phenylamino]benzene (abbreviation: DPA3B). 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 compounds that can be used include tris[4-(N-carbazolyl)phenyl]benzene (abbreviation: TCPB), 9-[4-(N-carbazolyl)]phenyl-10-phenylanthracene (abbreviation: 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).

[0080] 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.

[0081] The material having hole transport properties used in the composite material preferably has any one of a carbazole skeleton, a dibenzofuran skeleton, a dibenzothiophene skeleton, and an anthracene skeleton. In particular, the second organic compound may be an aromatic amine having a substituent containing a dibenzofuran ring or a dibenzothiophene ring, an aromatic monoamine having a naphthalene ring, or an aromatic monoamine in which a 9-fluorenyl group is bonded to the nitrogen of the amine via an arylene group. It is preferable that the second organic compound is a substance having an N,N-bis(4-biphenyl)amino group, because a light-emitting device with a long life can be fabricated. Specific examples of the second organic compound include N-(4-biphenyl)-6,N-diphenylbenzo[b]naphtho[1,2-d]furan-8-amine (abbreviation: BnfABP), N,N-bis(4-biphenyl)-6-phenylbenzo[b]naphtho[1,2-d]furan-8-amine (abbreviation: BBABnf), 4,4'-bis(6-phenylbenzo[b]naphtho[1,2-d]furan-8 -yl)-4''-phenyltriphenylamine (abbreviation: BnfBB1BP), N,N-bis(4-biphenyl)benzo[b]naphtho[1,2-d]furan-6-amine (abbreviation: BBABnf(6)), N,N-bis(4-biphenyl)benzo[b]naphtho[1,2-d]furan-8-amine (abbreviation: BBABnf(8)), N,N-bis(4-biphenyl)benzo[b]naphtho[2,3-d] Furan-4-amine (abbreviation: BBABnf(II)(4)), N,N-bis[4-(dibenzofuran-4-yl)phenyl]-4-amino-p-terphenyl (abbreviation: DBfBB1TP), N-[4-(dibenzothiophen-4-yl)phenyl]-N-phenyl-4-biphenylamine (abbreviation: ThBA1BP), 4-(2-naphthyl)-4',4''-diphenyltriphenylamine (abbreviation: : BBAβNB), 4-[4-(2-naphthyl)phenyl]-4',4''-diphenyltriphenylamine (abbreviation: BBAβNBi), 4,4'-diphenyl-4''-(6;1'-binaphthyl-2-yl)triphenylamine (abbreviation: BBAαNβNB), 4,4'-diphenyl-4''-(7;1'-binaphthyl-2-yl)triphenylamine (abbreviation: BBAαNβNB-03), 4,4'-Diphenyl-4''-(7-phenyl)naphthyl-2-yltriphenylamine (abbreviation: BBAPβNB-03), 4,4'-Diphenyl-4''-(6;2'-binaphthyl-2-yl)triphenylamine (abbreviation: BBA(βN2)B), 4,4'-Diphenyl-4''-(7;2'-binaphthyl-2-yl)triphenylamine (abbreviation: BBA(βN2)B-03), 4,4'-Diphenyl-4''-(4;2'-binaphthyl-1-yl)triphenylamine (abbreviation: BBAβNαNB), 4,4'-Diphenyl-4''-(5;2'- Binaphthyl-1-yl)triphenylamine (abbreviation: BBAβNαNB-02), 4-(4-biphenylyl)-4'-(2-naphthyl)-4''-phenyltriphenylamine (abbreviation: TPBiAβNB), 4-(3-biphenylyl)-4'-[4-(2-naphthyl)phenyl]-4''-phenyltriphenylamine (abbreviation: mTPBiAβNBi), 4-(4-biphenylyl)-4'-[4-(2-naphthyl)phenyl]-4''-phenyltriphenylamine (abbreviation: TPBiAβNBi), 4-phenyl-4'-(1-naphthyl)triphenylamine nylamine (abbreviation: αNBA1BP), 4,4'-bis(1-naphthyl)triphenylamine (abbreviation: αNBB1BP), 4,4'-diphenyl-4''-[4'-(carbazol-9-yl)biphenyl-4-yl]triphenylamine (abbreviation: YGTBi1BP), 4'-[4-(3-phenyl-9H-carbazol-9-yl)phenyl]tris(1,1'-biphenyl-4-yl)amine (abbreviation: YGTBi1BP-02), 4-[4'-(carbazol-9-yl)biphenyl-4-yl]-4'-(2-naphthyl)-4''-phenyl Triphenylamine (abbreviation: YGTBiβNB), N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-N-[4-(1-naphthyl)phenyl]-9,9'-spirobi(9H-fluorene)-2-amine (abbreviation: PCBNBSF), N,N-bis([1,1'-biphenyl]-4-yl)-9,9'-spirobi[9H-fluorene]-2-amine (abbreviation: BBASF), N,N-bis([1,1'-biphenyl]-4-yl)-9,9'-spirobi[9H-fluorene]-4-amine (abbreviation: BBASF(4)), N-(1,1'-biphenyl-2-yl)-N-(9,9-dimethyl-9H-fluoren-2-yl)-9,9'-spirobi(9H-fluorene)-4-amine (abbreviation: oFBiSF), N-(4-biphenyl)-N-(9,9-dimethyl-9H-fluoren-2-yl)dibenzofuran-4-amine (abbreviation: FrBiF), N-[4-(1-naphthyl)phenyl]-N-[3-(6-phenyldibenzofuran-4-yl)phenyl]-1-naphthylamine (abbreviation: mPDBfBNBN), 4-phenyl-4'-(9-phenylfluoren-9-yl)triphenylamine (abbreviation: mPDBfBNBN), triphenylamine (abbreviation: BPAFLP), 4-phenyl-3'-(9-phenylfluoren-9-yl)triphenylamine (abbreviation: mBPAFLP), 4-phenyl-4'-[4-(9-phenylfluoren-9-yl)phenyl]triphenylamine (abbreviation: BPAFLBi), 4-phenyl-4'-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBA1BP), 4,4'-diphenyl-4''-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBBi1BP), 4-(1-naphthyl)-4'-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBANB), 4,4'-di(1-naphthyl)-4''-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBNBB), N-phenyl-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-9,9'-spirobi[9H-fluorene]-2-amine (abbreviation: PCBASF), N-(1,1'-biphenyl-4-yl)-9,9-dimethyl-N-[4-(9-phenyl-9H- carbazol-3-yl)phenyl]-9H-fluoren-2-amine (abbreviation: PCBBiF), N,N-bis(9,9-dimethyl-9H-fluoren-2-yl)-9,9'-spirobi-9H-fluoren-4-amine, N,N-bis(9,9-dimethyl-9H-fluoren-2-yl)-9,9'-spirobi-9H-fluoren-3-amine, N,N-bis(9,9-dimethyl-9H-fluoren-2-yl)-9,9'-spirobi-9H-fluoren-2-amine, N,N-bis(9,9-dimethyl-9H-fluoren-2-yl)-9,9'-spirobi-9H-fluoren-2-amine, N,N-bis(9,9-dimethyl-9H-fluoren-2-yl)-9,Examples include 9'-spirobi-9H-fluorene-1-amine.

[0082] Note that the material having a hole-transporting property used in the composite material is more preferably a substance having a relatively deep HOMO level of −5.7 eV or more and −5.4 eV or less. When the material having a hole-transporting property used in the composite material has a relatively deep HOMO level, it becomes easy to inject holes into the hole-transporting layer 112, and it becomes easy to obtain a light-emitting device with a long lifetime.

[0083] 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, thereby improving the external quantum efficiency of the light-emitting device.

[0084] By forming the hole injection layer 111, the hole injection property is improved, and a light emitting device with a low driving voltage can be obtained. In addition, organic compounds having acceptor properties are easy to use because they can be easily evaporated and formed into a film.

[0085] The hole transport layer 112 is formed by including a material having a hole transport property. -6 cm 2The hole transporting material preferably has a hole mobility of 1000 nm or more. Examples of the hole transporting material 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: BPA FLP), 4-phenyl-3'-(9-phenylfluoren-9-yl)triphenylamine (abbreviated as mBPAFLP), 4-phenyl-4'-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviated as PCBA1BP), 4,4'-diphenyl-4''-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviated as PCBBi1BP), 4-(1-naphthyl)-4'-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviated as PCB Aromatic amines such as 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), and N-phenyl-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-9,9'-spirobi[9H-fluorene]-2-amine (abbreviation: PCBASF) 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.

[0086] The light-emitting layer 113 contains a light-emitting substance and a host material. The light-emitting layer 113 may contain other materials at the same time. The light-emitting layer 113 may also be a laminate of two layers having different compositions.

[0087] The luminescent material may be a fluorescent material, a phosphorescent material, a material exhibiting thermally activated delayed fluorescence (TADF), or any other luminescent material.

[0088] Examples of materials that can be used as the fluorescent substance in the light-emitting layer 113 include 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) 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-butyl)perylene (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: 2DPABPhA), 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-diphenyltetrahydrofuran N,N,N',N'-tetrakis(4-methylphenyl)tetracene-5,11-diamine (abbreviation: p-mPhTD), 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',N'-tetrakis(4-methylphenyl)acenaphtho[1,2-a]fluoranthene-3,10-diamine (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'-(Pi 1,6BnfAPrn-03), 3,10-bis[N-(9-phenyl-9H-carbazol-2-yl)-N-phenylamino]naphtho[2,3-b;6,7-b']bisbenzofuran (abbreviation: 3,10PCA2Nbf(IV)-02), 3,10-bis[N-(dibenzofuran-3-yl)-N-phenylamino]naphtho[2,3-b;6,7-b']bisbenzofuran (abbreviation: 3,10FrA2Nbf(IV)-02). 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. Other fluorescent substances can also be used.

[0089] In the case where a phosphorescent material is used as the light-emitting material in the light-emitting layer 113, examples of materials that can be used include 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, Organometallic iridium complexes with a 4H-triazole skeleton, such as tris[4-(3-biphenyl)-5-isopropyl-3-phenyl-4H-1,2,4-triazolato]iridium(III) (abbreviation: [Ir(Mptz)3]) and 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-1,2,4-triazolato]iridium(III) (abbreviation: [Ir(iPrptz-3b)3]) Organometallic iridium complexes with 1H-triazole skeletons, such as tris(1-methyl-5-phenyl-3-propyl-1H-1,2,4-triazolato)iridium(III) (abbreviation: [Ir(Mptz1-mp)3]) and tris(1-methyl-5-phenyl-3-propyl-1H-1,2,4-triazolato)iridium(III) (abbreviation: [Ir(Prptz1-Me)3]), and fac-tris[1-(2,6-diisopropylphenyl)-2-phenyl- Organometallic iridium complexes with an imidazole skeleton, such as tris[3-(2,6-dimethylphenyl)-7-methylimidazo[1,2-f]phenanthridinato]iridium(III) (abbreviation: [Ir(iPrpmi)3]) and 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 (abbreviation: FIr(acac)), are examples of such compounds that exhibit blue phosphorescence and have emission peaks at 440 nm to 520 nm.

[0090] 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, and have an emission peak at 500 nm to 600 nm. In addition, organometallic iridium complexes having a pyrimidine skeleton are particularly preferred because they are remarkably excellent in reliability and luminous efficiency.

[0091] 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. These are compounds that exhibit red phosphorescence and have a peak emission wavelength of 600 to 700 nm. Furthermore, an organometallic iridium complex having a pyrazine skeleton can emit red light with good chromaticity.

[0092] In addition to the phosphorescent compounds described above, known phosphorescent light-emitting substances may be selected and used.

[0093] 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.

[0094] [ka]

[0095] In addition, 2-(biphenyl-4-yl)-4,6-bis(12-phenylindolo[2,3-a]carbazol-11-yl)-1,3,5-triazine (abbreviation: PIC-TRZ), 9-(4,6-diphenyl-1,3,5-triazin-2-yl)-9'-phenyl-9H,9'H-3,3'-bicarbazole (abbreviation: PCCzTzn), 2-{4-[3-(N-phenyl-9H-carbazol-3-yl)-9H-carbazol-9-yl]phenyl}-4,6-diphenyl-1,3,5-triazine (abbreviation: PCCzPTzn), 2-[4-(10H-phenoxazin-10-yl)phenyl]-4,6-diphenyl-1,3,5-triazine (abbreviation: PCCzPTzn), Heterocyclic compounds having one or both of a π-electron rich heteroaromatic ring and a π-electron deficient heteroaromatic ring, such as 3-[4-(5-phenyl-5,10-dihydrophenazin-10-yl)phenyl]-4,5-diphenyl-1,2,4-triazole (abbreviation: PPZ-3TPT), 3-(9,9-dimethyl-9H-acridin-10-yl)-9H-xanthen-9-one (abbreviation: ACRXTN), bis[4-(9,9-dimethyl-9,10-dihydroacridine)phenyl]sulfone (abbreviation: DMAC-DPS), and 10-phenyl-10H,10'H-spiro[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, and is therefore preferred. Among the skeletons having a π-electron deficient heteroaromatic ring, the pyridine skeleton, the diazine skeleton (pyrimidine skeleton, pyrazine skeleton, pyridazine skeleton), and the triazine skeleton are preferred because they are stable and reliable. In particular, the benzofuropyrimidine skeleton, the benzothienopyrimidine skeleton, the benzofuropyrazine skeleton, and the benzothienopyrazine skeleton are preferred because they have high acceptor properties and good reliability. In addition, among the skeletons having a π-electron rich heteroaromatic ring, the acridine skeleton, the phenoxazine skeleton, the phenothiazine skeleton, the furan skeleton, the thiophene skeleton, and the pyrrole skeleton are preferred because they are stable and reliable.In addition, the furan skeleton is preferably a dibenzofuran skeleton, and the thiophene skeleton is preferably a dibenzothiophene skeleton. In addition, the pyrrole skeleton is particularly preferably an indole skeleton, a carbazole skeleton, an indolocarbazole skeleton, a bicarbazole skeleton, or a 3-(9-phenyl-9H-carbazol-3-yl)-9H-carbazole skeleton. 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 electron donating property of the π-electron-rich heteroaromatic ring and the electron accepting 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 to which an electron-withdrawing group such as a cyano group is bonded may be used instead of the π-electron-deficient heteroaromatic ring. In addition, an aromatic amine skeleton, a phenazine skeleton, or the like can be used as the π-electron-rich skeleton. In addition, examples of the π-electron-deficient skeleton that can be used include a xanthene skeleton, a thioxanthene dioxide skeleton, an oxadiazole skeleton, a triazole skeleton, an imidazole skeleton, an anthraquinone skeleton, a boron-containing skeleton such as phenylborane or boranthrene, an aromatic ring or a heteroaromatic ring having a nitrile group or a cyano group such as benzonitrile or cyanobenzene, a carbonyl skeleton such as benzophenone, a phosphine oxide skeleton, a sulfone skeleton, etc. In this way, a π-electron-deficient skeleton and a π-electron-rich skeleton can be used in place of at least one of a π-electron-deficient heteroaromatic ring and a π-electron-rich heteroaromatic ring.

[0096] [ka]

[0097] TADF materials are materials that have a small difference between the S1 and T1 levels and have the function of converting triplet excitation energy to singlet excitation energy by reverse intersystem crossing. Therefore, triplet excitation energy can be upconverted to singlet excitation energy by a small amount of thermal energy (reverse intersystem crossing), and singlet excitation states can be generated efficiently. In addition, triplet excitation energy can be converted into light emission.

[0098] In addition, exciplexes (also called exciplexes), which form an excited state with two types of substances, have an extremely small difference between the S1 level and the T1 level and function as TADF materials that can convert triplet excitation energy into singlet excitation energy.

[0099] As an index of the T1 level, a phosphorescence spectrum observed at low temperatures (for example, 77 K to 10 K) may be used. For a TADF material, when a tangent line is drawn at the base of the short wavelength side of the fluorescence spectrum, and the energy of the wavelength of the extrapolated line is taken as the S1 level, and a tangent line is drawn at the base of the short wavelength side of the phosphorescence spectrum, and the energy of the wavelength of the extrapolated line is taken as the T1 level, the difference between S1 and T1 is preferably 0.3 eV or less, and more preferably 0.2 eV or less.

[0100] In addition, when a TADF material is used as a light-emitting material, the S1 level of the host material is preferably higher than the S1 level of the TADF material, and the T1 level of the host material is preferably higher than the T1 level of the TADF material.

[0101] As the host material of the light-emitting layer, various carrier transporting materials such as a material having an electron transporting property, a material having a hole transporting property, or the above-mentioned TADF material can be used.

[0102] As a material having hole transport properties, an organic compound having an amine skeleton or a π-electron-rich heteroaromatic ring skeleton is preferable. For example, 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: BPAFLP ... mBPAFLP, 4-phenyl-4'-(9-phenyl-9H-carbazol-3-yl)triphenylamine (PCBA1BP), 4,4'-diphenyl-4''-(9-phenyl-9H-carbazol-3-yl)triphenylamine (PCBBi1BP), 4-(1-naphthyl)-4'-(9-phenyl-9H-carbazol-3-yl)triphenylamine (PCBANB), 4, Aromatic amine skeletons such as 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), and N-phenyl-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-9,9'-spirobi[9H-fluorene]-2-amine (abbreviation: PCBASF) 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 transport properties, and contribute to reducing the driving voltage.

[0103] 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), as well as organic compounds having a π-electron-deficient heteroaromatic ring skeleton. Examples of organic compounds having a π-electron-deficient heteroaromatic ring skeleton include 2-(4-biphenylyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole (abbreviation: PBD), 3-(4-biphenylyl)-4-phenyl-5-(4-tert-butylphenyl)-1,2,4-triazole (abbreviation: TAZ), 1,3-bis[5-(p-tert-butylphenyl)-1,3,4-oxadiazole], 2,2',2''-(1,3,5-benzenetriyl)tris(1-phenyl-1H-benzimidazole) (abbreviation: TPBI), 2-[3-(dibenzothiophen-4-yl)phenyl]-1-phenyl-1H-benzene Heterocyclic compounds with polyazole skeletons such as dibenzothiophene (abbreviation: mDBTBIm-II), 2-[3-(dibenzothiophene-4-yl)phenyl]dibenzo[f,h]quinoxaline (abbreviation: 2mDBTPDBq-II), 2-[3'-(dibenzothiophene-4-yl)biphenyl-3-yl]dibenzo[f,h]quinoxaline (abbreviation: 2mDBTBPDBq-II), 2-[3'-(9H-cathionyl)phenyl]dibenzo[f,h]quinoxaline (abbreviation: 2mDBTPDBq-II), Heterocyclic compounds with diazine skeletons such as 2-[3'-(9,9-Dimethyl-9H-fluoren-2-yl)-1,1'-biphenyl-3-yl]-4,6-diphenyl-1,3,5-triazine (abbreviation: mFBPTzn), 2-[(1,1'-biphenyl)-4-yl]-4-phenyl-6-[9,9'-spirobi(9H-fluoren)-2-yl]-1,3,5-triazine (abbreviation: BP-SFTzn), 2-{3-[3-(benzo[b]naphtho[1,2-d]furan-8-yl)phenyl]phenyl}-4,6-diphenyl-1,3,5-triazine (abbreviation: m Examples of the heterocyclic compounds include heterocyclic compounds having a triazine skeleton such as 2-{3-[3-(benzo"b"naphtho[1,2-d]furan-6-yl)phenyl]phenyl}-4,6-diphenyl-1,3,5-triazine (abbreviation: mBnfBPTzn-02), and heterocyclic compounds having a pyridine skeleton such as 3,5-bis[3-(9H-carbazol-9-yl)phenyl]pyridine (abbreviation: 35DCzPPy) and 1,3,5-tri[3-(3-pyridyl)phenyl]benzene (abbreviation: TmPyPB). Among the above, heterocyclic compounds having a diazine skeleton, heterocyclic compounds having a triazine skeleton, and heterocyclic compounds having a pyridine skeleton are preferred because of their good reliability. In particular, heterocyclic compounds having a diazine (pyrimidine or pyrazine) skeleton have high electron transport properties and contribute to reducing the driving voltage. The organic compound described in embodiment 1 has an electron transporting property and can be suitably used as a host material in the light-emitting layer.

[0104] As a TADF material that can be used as a host material, the same TADF materials listed above can be used. When a TADF material is used as a host material, the triplet excitation energy generated in the TADF material is converted to singlet excitation energy by reverse intersystem crossing, and the energy is then transferred to the light-emitting material, thereby increasing the light-emitting efficiency of the light-emitting device. In this case, the TADF material functions as an energy donor, and the light-emitting material functions as an energy acceptor.

[0105] This is very effective when the luminescent material is a fluorescent luminescent material. In this case, in order to obtain high luminous efficiency, the S1 level of the TADF material is preferably higher than the S1 level of the fluorescent luminescent material. In addition, the T1 level of the TADF material is preferably higher than the S1 level of the fluorescent luminescent material. Therefore, the T1 level of the TADF material is preferably higher than the T1 level of the fluorescent luminescent material.

[0106] It is also preferable to use a TADF material that emits light that overlaps with the wavelength of the lowest energy absorption band of the fluorescent material, because this allows for smooth transfer of excitation energy from the TADF material to the fluorescent material, resulting in efficient emission.

[0107] In addition, in order to efficiently generate singlet excitation energy from triplet excitation energy by reverse intersystem crossing, it is preferable that carrier recombination occurs in the TADF material. In addition, it is preferable that the triplet excitation energy generated in the TADF material does not transfer to the triplet excitation energy of the fluorescent material. For this purpose, it is preferable that the fluorescent material has a protective group around the luminophore (skeleton causing light emission) of the fluorescent material. As the protective group, a substituent having no π bond is preferable, and a saturated hydrocarbon is preferable, specifically, an alkyl group having 3 to 10 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 10 carbon atoms, and a trialkylsilyl group having 3 to 10 carbon atoms are mentioned, and it is more preferable that there are a plurality of protective groups. Since a substituent having no π bond has poor function of transporting carriers, the distance between the TADF material and the luminophore of the fluorescent material can be increased without affecting carrier transport or carrier recombination. Here, the luminophore refers to an atomic group (skeleton) causing light emission in the fluorescent material. The luminophore preferably has a skeleton having a π bond, preferably contains an aromatic ring, and preferably has a condensed aromatic ring or a condensed heteroaromatic ring. Examples of the condensed aromatic ring or the condensed heteroaromatic ring include a phenanthrene skeleton, a stilbene skeleton, an acridone skeleton, a phenoxazine skeleton, and a phenothiazine skeleton. In particular, fluorescent substances having a naphthalene skeleton, an anthracene skeleton, a fluorene skeleton, a chrysene skeleton, a triphenylene skeleton, a tetracene skeleton, a pyrene skeleton, a perylene skeleton, a coumarin skeleton, a quinacridone skeleton, or a naphthobisbenzofuran skeleton are preferred because they have a high fluorescence quantum yield.

[0108] When a fluorescent emitting material is used as the 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 emitting material, it is possible to realize an emitting layer having both good luminous efficiency and durability. As a material having an anthracene skeleton to be used as the host material, a material having 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 injection and transport properties of holes 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 that of 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 that of 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 material 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 material 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: CzPA), and 7-[4-(10-phenyl-9-anthryl)phenyl]-7H-dibenzo[c,g]carbazole (abbreviation: CzPA). Examples of such compounds include 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 9-(1-naphthyl)-10-[4-(2-naphthyl)phenyl]anthracene (abbreviation: αN-βNPAnth).In particular, CzPA, cgDBCzPA, 2mBnfPPA, and PCzPA are preferred choices since they exhibit very good properties.

[0109] The host material may be a mixture of a plurality of substances. When a mixture of host materials is used, it is preferable to mix a 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 weight ratio of the content of the material having a hole transporting property to the material having an electron transporting property may be 1:19 to 19:1 (material having a hole transporting property: material having an electron transporting property). As the material having an electron transporting property in the mixed host material, the organic compound described in embodiment 1 can be preferably used.

[0110] A phosphorescent material can be used as a part of the mixed material. The phosphorescent material can be used as an energy donor that provides excitation energy to a fluorescent material when the fluorescent material is used as a light-emitting material.

[0111] 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.

[0112] At least one of the materials forming the exciplex may be a phosphorescent material, which allows the triplet excitation energy to be efficiently converted into singlet excitation energy by reverse intersystem crossing.

[0113] As a combination of materials that efficiently form an exciplex, it is preferable that the HOMO level of the material having hole transport properties is equal to or higher than the HOMO level of the material having electron transport properties. It is also preferable that the LUMO level of the material having hole transport properties is equal to or higher than the LUMO level of the material having electron transport properties. The LUMO level and HOMO level of the material can be derived from the electrochemical properties (reduction potential and oxidation potential) of the material measured by cyclic voltammetry (CV) measurement.

[0114] The formation of an exciplex can be confirmed, for example, by comparing the emission spectrum of a material having hole transport properties, the emission spectrum of a material having electron transport properties, and the emission spectrum of a mixed film obtained by mixing these materials, and observing the phenomenon that the emission spectrum of the mixed film shifts to a longer wavelength than the emission spectrum of each material (or has a new peak on the longer wavelength side). Alternatively, the formation of an exciplex can be confirmed by comparing the transient photoluminescence (PL) of a material having hole transport properties, the transient PL of a material having electron transport properties, and the transient PL of a mixed film obtained by mixing these materials, and observing the difference in transient response, such as the transient PL lifetime of the mixed film having a longer lifetime component than the transient PL lifetime of each material, or the proportion of delayed components becoming larger. The above-mentioned transient PL may also be read as transient electroluminescence (EL). That is, the formation of an exciplex can also be confirmed by comparing the transient EL of a material having hole transport properties, the transient EL of a material having electron transport properties, and the transient EL of a mixed film obtained by mixing these materials, and observing the difference in transient response.

[0115] 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.

[0116] The electron transport layer 114 has an electron mobility of 1×10 -7 cm 2 / Vs or more 5×10 -5 cm 2 / Vs or less. By lowering the electron transportability in the electron transport layer 114, the amount of electrons injected into the light-emitting layer can be controlled, and the light-emitting layer can be prevented from becoming in an electron excess state. In addition, the electron transport layer 114 preferably contains a material having electron transportability and an elemental substance, compound, or complex of an alkali metal or an alkaline earth metal. These configurations are particularly preferable when the hole injection layer is formed as a composite material, and the HOMO level of the material having hole transportability in the composite material is a substance having a relatively deep HOMO level of -5.7 eV or more and -5.4 eV or less, because the lifetime is improved. In this case, the material having electron transportability preferably has a HOMO level of -6.0 eV or more. In addition, the material having electron transportability is preferably an organic compound having an anthracene skeleton, and more preferably an organic compound having both an anthracene skeleton and a heterocyclic skeleton. The heterocyclic skeleton is preferably a nitrogen-containing 5-membered skeleton or a nitrogen-containing 6-membered skeleton, and particularly preferably has a nitrogen-containing 5-membered skeleton or a nitrogen-containing 6-membered skeleton containing two heteroatoms in the ring, such as a pyrazole ring, an imidazole ring, an oxazole ring, a thiazole ring, a pyrazine ring, a pyrimidine ring, or a pyridazine ring. In addition, the simple substance, compound, or complex of an alkali metal or an alkaline earth metal preferably contains an 8-hydroxyquinolinato structure. Specifically, for example, 8-hydroxyquinolinato-lithium (abbreviation: Liq) and 8-hydroxyquinolinato-sodium (abbreviation: Naq) can be mentioned. In particular, a complex of a monovalent metal ion, particularly a lithium complex, is preferable, and Liq is more preferable. In addition, when the 8-hydroxyquinolinato structure is contained, a methyl-substituted product (for example, a 2-methyl-substituted product or a 5-methyl-substituted product) can also be used. In the electron transport layer, it is preferable that the alkali metal or alkaline earth metal simple substance, compound, or complex has a concentration difference (including the case where the concentration difference is 0) in the thickness direction.

[0117] 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 8-hydroxyquinolinato-lithium (abbreviation: Liq), 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.

[0118] Note that a layer containing a fluoride of the alkali metal or alkaline earth metal in a substance having an electron transporting property (preferably an organic compound having a bipyridine skeleton) at a concentration at which the fluoride is in a microcrystalline state or higher (50 wt % or higher) can be used as the electron injection layer 115. Since this layer has a low refractive index, it is possible to provide a light-emitting device with better external quantum efficiency.

[0119] Alternatively, a charge generation layer 116 may be provided instead of the electron injection layer 115 (FIG. 1(B)). 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 as a material capable of forming the hole injection layer 111. The P-type layer 117 may be formed by laminating a film containing an acceptor material and a film containing a hole transport material, both of 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 the cathode, and the light-emitting device operates. In addition, since the organic compound according to one embodiment of the present invention is an organic compound having a low refractive index, a light-emitting device having good external quantum efficiency can be obtained by using the organic compound for the P-type layer 117.

[0120] 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 .

[0121] 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.

[0122] 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)).

[0123] 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.

[0124] 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.

[0125] 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.

[0126] Moreover, the above-mentioned electrodes or layers may be formed using different film formation methods.

[0127] 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.

[0128] 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.

[0129] Next, an embodiment of a light-emitting device having a structure in which a plurality of light-emitting units are stacked (also called a stacked element or a tandem element) will be described with reference to FIG. 1(C). This light-emitting device has a plurality of 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, the light-emitting device shown in FIG. 1(C) is a light-emitting device having a plurality of light-emitting units, and the light-emitting device shown in FIG. 1(A) or FIG. 1(B) can be said to be a light-emitting device having one light-emitting unit.

[0130] 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.

[0131] 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.

[0132] 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.

[0133] 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.

[0134] 1C, a light-emitting device having two light-emitting units has been described, but the present invention can be applied to a light-emitting device having three or more light-emitting units stacked in the same manner. 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 device according to this embodiment, it is possible to realize a device that can emit high-luminance light while keeping the current density low and has a long life. In addition, it is possible to realize a light-emitting device that can be driven at a low voltage and consumes low power.

[0135] 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 from the light-emitting device as a whole. For example, in a light-emitting device having two light-emitting units, it is possible to obtain a light-emitting device that emits white light as a whole by obtaining red and green emission colors from the first light-emitting unit and blue emission color from the second light-emitting unit.

[0136] 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.

[0137] (Embodiment 3) In this embodiment, a light emitting apparatus using the light emitting device described in Embodiment 2 will be described.

[0138] In this embodiment, a light-emitting device manufactured using the light-emitting device 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 device. Reference numeral 604 denotes a sealing substrate, 605 denotes a sealant, and the inside surrounded by the sealant 605 defines a space 607.

[0139] 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.

[0140] 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.

[0141] 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.

[0142] 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.

[0143] 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.

[0144] 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.

[0145] 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).

[0146] 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.

[0147] By using such a material for the semiconductor layer, fluctuations in electrical characteristics are suppressed, and a highly reliable transistor can be realized.

[0148] 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.

[0149] 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.

[0150] 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.

[0151] 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.

[0152] 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.

[0153] 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.

[0154] 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.

[0155] 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).

[0156] 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.).

[0157] Note that a light-emitting device is formed with the first electrode 613, the EL layer 616, and the second electrode 617. The light-emitting device is the light-emitting device described in Embodiment 2. Note that a pixel portion is formed with a plurality of light-emitting devices, but the light-emitting device in this embodiment may include both the light-emitting device described in Embodiment 2 and light-emitting devices having other structures.

[0158] 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 device 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 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.

[0159] 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.

[0160] 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.

[0161] 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.

[0162] 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.

[0163] 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.

[0164] 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.

[0165] In the above manner, a light-emitting device manufactured using the light-emitting device described in Embodiment 2 can be obtained.

[0166] A light-emitting device with favorable characteristics can be obtained in the light-emitting device of this embodiment because the light-emitting device described in Embodiment 2 is used. Specifically, since the light-emitting device described in Embodiment 2 has favorable emission efficiency, it is possible to provide a light-emitting device with low power consumption.

[0167] 3 shows an example of a full-color light-emitting device in which a light-emitting device that emits white light is formed and a colored layer (color filter) is provided, etc. In FIG. 3(A), a substrate 1001, a base insulating film 1002, a gate insulating film 1003, gate electrodes 1006, 1007, 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, 1024B of the light-emitting device, a partition wall 1025, an EL layer 1028, a second electrode 1029 of the light-emitting device, a sealing substrate 1031, a sealant 1032, etc. are shown.

[0168] 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.

[0169] 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.

[0170] In the light-emitting device described above, the light-emitting device has a structure (bottom emission type) in which light is extracted to 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 to 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 device is formed. Then, 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, as well as other known materials.

[0171] The first electrodes 1024W, 1024R, 1024G, and 1024B of the light-emitting device 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 configuration as that described for the EL layer 103 in the second embodiment, and has an element structure that can emit white light.

[0172] In the top emission structure as shown in FIG. 4, sealing can be performed with a sealing substrate 1031 provided with colored layers (a red colored layer 1034R, a green colored layer 1034G, and a 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 (the red colored layer 1034R, the green colored layer 1034G, and the blue colored layer 1034B) and the black matrix may be covered with an overcoat layer 1036. 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.

[0173] In a top-emission type light-emitting device, a microcavity structure can be suitably applied. A light-emitting device having a microcavity structure can be 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.

[0174] 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.

[0175] 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.

[0176] 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 resonating wavelengths and attenuate the light of non-resonating wavelengths between the reflective electrode and the semi-transmissive / semi-reflective electrode.

[0177] 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.

[0178] In the above configuration, the EL layer may have a structure having multiple 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 light-emitting device configuration, in which multiple EL layers are provided in one light-emitting device with a charge generation layer sandwiched therebetween, and a single or multiple light-emitting layers are formed in each EL layer.

[0179] 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.

[0180] A light-emitting device with favorable characteristics can be obtained in the light-emitting device of this embodiment because the light-emitting device described in Embodiment 2 is used. Specifically, since the light-emitting device described in Embodiment 2 has favorable emission efficiency, it is possible to provide a light-emitting device with low power consumption.

[0181] 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 device due to static electricity or the like can be prevented. In addition, the light-emitting device described in Embodiment 2 is used in a passive matrix light-emitting device, and the light-emitting device can be made to be highly reliable or to have low power consumption.

[0182] The light emitting device described above is capable of individually controlling a large number of minute light emitting devices arranged in a matrix, and is therefore a light emitting device that can be suitably used as a display device for displaying images.

[0183] This embodiment mode can be freely combined with other embodiment modes.

[0184] (Embodiment 4) In this embodiment, an example in which the light-emitting device 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).

[0185] 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.

[0186] A pad 412 for supplying a voltage to the second electrode 404 is formed on the substrate 400 .

[0187] 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.

[0188] 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.

[0189] As described above, the lighting device described in this embodiment has a light-emitting device including the first electrode 401, the EL layer 403, and the second electrode 404. Since the light-emitting device has high emission efficiency, the lighting device in this embodiment can have low power consumption.

[0190] The substrate 400 on which the light-emitting device 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. Also, a desiccant may be mixed into the inner sealant 406 (not shown in FIG. 6(B)), which can adsorb moisture and improve reliability.

[0191] 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.

[0192] As described above, the lighting device described in this embodiment uses the light-emitting device described in Embodiment 2 as its EL element, and can be a lighting device with low power consumption.

[0193] (Embodiment 5) In this embodiment, an example of an electronic device including the light-emitting device described in Embodiment 2 as a part thereof will be described. The light-emitting device described in Embodiment 2 has good light-emitting 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.

[0194] Examples of electronic devices to which the light-emitting devices are applied include television sets (also called televisions or television receivers), computer monitors, 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.

[0195] 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 devices described in Embodiment 2 are arranged in a matrix.

[0196] 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.

[0197] 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.

[0198] 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 devices 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.

[0199] 7C shows an example of a mobile terminal. The mobile phone includes a display portion 7402 incorporated in 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 devices described in Embodiment 2 are arranged in a matrix.

[0200] 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.

[0201] 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.

[0202] 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.

[0203] 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.

[0204] 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.

[0205] 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.

[0206] 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.

[0207] FIG. 8(A) is a schematic diagram showing an example of a cleaning robot.

[0208] 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.

[0209] 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.

[0210] 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.

[0211] 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.

[0212] 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 the portable electronic device 5140 such as a smartphone.

[0213] The light-emitting device according to one embodiment of the present invention can be used for the display 5101 .

[0214] 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.

[0215] 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.

[0216] 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.

[0217] 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.

[0218] 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.

[0219] The light-emitting device of one embodiment of the present invention can be used for the display portion 5001 and the display portion 5002 .

[0220] 9 shows an example in which the light-emitting device described in Embodiment 2 is used in a desk lamp, which is a lighting device. The desk lamp shown in FIG. 9 has a housing 2001 and a light source 2002, and the lighting device described in Embodiment 3 may be used as the light source 2002.

[0221] FIG. 10 shows an example in which the light-emitting device described in Embodiment 2 is used as an indoor lighting device 3001. Since the light-emitting device described in Embodiment 2 has high emission efficiency, it can be used as a lighting device with low power consumption. In addition, since the light-emitting device described in Embodiment 2 can be made large, it can be used as a large-area lighting device. In addition, since the light-emitting device described in Embodiment 2 is thin, it can be used as a thin lighting device.

[0222] The light-emitting device described in Embodiment 2 can also be mounted on a windshield or dashboard of an automobile. FIG 11 shows an example in which the light-emitting device described in Embodiment 2 is used on a windshield or dashboard of an automobile. Display regions 5200 to 5203 are provided using the light-emitting device described in Embodiment 2.

[0223] A display region 5200 and a display region 5201 are display devices equipped with the light-emitting device described in embodiment 2, which is provided on the windshield of an automobile. The light-emitting device described in embodiment 2 can be a so-called see-through display device in which the opposite side can be seen through by manufacturing the first electrode and the 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 the view. 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.

[0224] A display area 5202 is a display device provided on a pillar and equipped with the light-emitting device described in Embodiment 2. By displaying an image from an imaging means provided on the vehicle body in the display area 5202, the view blocked by the pillar can be complemented. Similarly, a display area 5203 provided on the dashboard can complement the view blocked by the vehicle body by displaying an image from an imaging means provided on the outside of 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.

[0225] The display area 5203 can also provide various information by displaying navigation information, a speedometer, a tachometer, a mileage, a fuel gauge, a gear status, air conditioning settings, and the like. 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.

[0226] 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.

[0227] 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.

[0228] 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.

[0229] 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.

[0230] 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.

[0231] 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.

[0232] As described above, the light-emitting device having the light-emitting device 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 device described in Embodiment 2, electronic devices with low power consumption can be obtained. EXAMPLES

[0233] <Synthesis Example 1> In this Synthesis Example 1, a synthesis example of 4,8-bis[3-(dibenzothiophen-4-yl)phenyl]benzo[h]quinazoline (abbreviation: 4,8mDBtP2Bqn) shown as structural formula (100) in the embodiment 1 will be specifically illustrated. The structural formula of 4,8mDBtP2Bqn is shown below.

[0234] [ka]

[0235] <Step 1: Synthesis of 8-chloro-5,6-dihydrobenzo[h]quinazoline> 31g (172mmol) of 6-chloro-1-tetralone, 49g (338mmol) of N,N',N"-methylidynetrisformamide, 1.58g (8.3mmol) of p-toluenesulfonic acid monohydrate, and 55mL of formamide were placed in a three-neck flask and heated and stirred at 160℃ for 7 hours under a nitrogen stream. After a predetermined time had passed, this reaction mixture was added to a 2M aqueous solution of sodium hydroxide and stirred at room temperature for 2 hours. After stirring, toluene was added to this mixture and the aqueous layer and organic layer were separated. The organic layer was washed with water and saturated saline, and dried by adding anhydrous magnesium sulfate. The mixture was gravity filtered, and the filtrate was concentrated to obtain a solid. This solid was purified by silica gel column chromatography. A mixed solvent of toluene:ethyl acetate = 5:1 was used as the developing solvent. The solid obtained by concentrating the obtained fraction was washed with a mixed solvent of toluene and hexane to obtain 25g of the target yellow solid in a yield of 66%. The synthesis scheme of step 1 is shown below.

[0236] [ka]

[0237] <Step 2: Synthesis of 8-chlorobenzo[h]quinazoline> 20 g (93 mmol) of 8-chloro-5,6-dihydrobenzo[h]quinazoline obtained in step 1 and 360 mL of o-dichlorobenzene were placed in a three-neck flask, and 21 g (186 mmol) of 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) was added thereto, and the mixture was stirred at 120°C for 13 hours under a nitrogen stream. After a predetermined time had elapsed, the reaction mixture was added to 500 mL of 1 M aqueous sodium hydroxide solution and extracted with dichloromethane. The extracted solution and the organic phase were combined and washed with water, saturated aqueous sodium bicarbonate solution, and saturated saline, and anhydrous magnesium sulfate was added to the organic phase to dry it. The mixture obtained was naturally filtered, and the filtrate was concentrated to obtain a solid. This solid was purified by flash column chromatography. Toluene was used as the developing solvent at first, and then a mixed solvent of toluene:ethyl acetate = 1:1 was used. The obtained fraction was concentrated to obtain 3.1 g of the target brown solid in a yield of 16%. The synthesis scheme of step 2 is shown below.

[0238] [ka]

[0239] <Step 3: Synthesis of 8-chlorobenzo[h]quinazolin-4-one> 3.1 g (14 mmol) of 8-chlorobenzo[h]quinazoline obtained in step 2 above and 15 mL of acetic acid were placed in a three-neck flask, and 82 mL of an aqueous solution of 31 g (58 mmol) of ammonium cerium nitrate was added thereto, and the mixture was stirred at room temperature for 18 hours under a nitrogen stream. After a predetermined time had elapsed, 10 mL of an aqueous solution of 3.9 g (7.1 mmol) of ammonium cerium nitrate was further added to the mixture, and the mixture was stirred at room temperature for 2.5 hours. After a predetermined time had elapsed, the reaction mixture obtained was suction filtered, and the solid was washed with acetic acid, water, a saturated aqueous solution of sodium bicarbonate, and ethanol in that order, to obtain 2.7 g of the desired yellow solid in an 81% yield. The synthetic scheme of step 3 is shown below.

[0240] [ka]

[0241] <Step 4: Synthesis of 4,8-dichlorobenzo[h]quinazoline> 2.9g (12mmol) of 8-chlorobenzo[h]quinazolin-4-one obtained in step 3 above and 20g (130mmol) of phosphoryl chloride were placed in a three-neck flask and heated under reflux for 7 hours. After a certain time had passed, the resulting reaction mixture was dissolved in toluene and neutralized by gradually adding it to a saturated aqueous solution of sodium bicarbonate. The organic layer and the aqueous layer of the resulting mixture were separated, and the organic layer was washed with saturated saline. Anhydrous magnesium sulfate was added to the organic layer to dry it, and the resulting mixture was naturally filtered to obtain a filtrate. The filtrate was concentrated, and the resulting solid was dissolved in toluene and suction-filtered through a filter material layered in the order of Celite, alumina, and Celite. The solid obtained by concentrating the filtrate was washed with a mixed solvent of toluene and hexane, and 1.6g of the desired white solid was obtained in a yield of 52%. The synthesis scheme of step 4 is shown below.

[0242] [ka]

[0243] <Step 5: Synthesis of 4,8-bis[3-(dibenzothiophen-4-yl)phenyl]benzo[h]quinazoline (abbreviation: 4,8mDBtP2Bqn)> Next, 1.0 g (4.0 mmol) of 4,8-dichlorobenzo[h]quinazoline obtained in step 4 above, 2.8 g (9.2 mmol) of 3-(dibenzothiophen-4-yl)phenylboronic acid, 5.8 g (28 mmol) of tripotassium phosphate, 30 mL of diglyme, and 2.0 g (28 mmol) of tert-butanol were placed in a three-neck flask, and the flask was replaced with nitrogen. The mixture was heated to 60°C, and 36 mg (0.16 mmol) of palladium(II) acetate and 115 mg (0.32 mmol) of di(1-adamantyl)-n-butylphosphine were added, followed by heating and stirring at 120°C for 11 hours. Water was added to the reaction mixture obtained, and the precipitated solid was filtered by suction and washed with water and ethanol in that order. The obtained solid was dissolved in toluene and filtered by suction through a layer of Celite and alumina in that order. The filtrate was concentrated to give a solid, which was then recrystallized from toluene to give 1.9 g of the target white solid in a yield of 68%. The synthetic scheme of Step 5 is shown below.

[0244] [ka]

[0245] The resulting white solid (1.9 g) was purified by train sublimation (pressure 3.5 × 10 -3 After purification by sublimation, the target product, 4,8-bis[3-(dibenzothiophen-4-yl)phenyl]benzo[h]quinazoline (abbreviation: 4,8mDBtP2Bqn), was obtained in a yield of 1.3 g (white solid, recovery rate 68%).

[0246] Nuclear magnetic resonance spectroscopy of the white solid obtained in step 5 above ( 1 The results of the analysis by H-NMR are shown below. 1 The H-NMR chart is shown in Figure 14. From this, it was confirmed that 4,8mDBtP2Bqn was obtained by this synthesis example.

[0247] 1H-NMR.δ(CDCl3):7.46-7.52(m,4H),7.59-7.63(m,4H),7.70(t,1H),7.78(t,1H),7.81-7.83(m,1H), 7.85-7.90(m,3H),7.91-7.94(m,1H),7.97-8.00(m,2H),8.15-8.25(m,9H),9.45(d,1H),9.58(s,1H).

[0248] Next, the ultraviolet-visible absorption spectrum (hereinafter simply referred to as "absorption spectrum") and emission spectrum of 4,8mDBtP2Bqn in the solution state and in the thin film state were measured.

[0249] The measurement of each spectrum in the solution state was carried out using a toluene solution of 4,8mDBtP2Bqn. The absorption spectrum was measured using an ultraviolet-visible spectrophotometer (V550 model, manufactured by JASCO Corporation), and the emission spectrum was measured using a fluorometer (FS920, manufactured by Hamamatsu Photonics Corporation). The measurement results of the absorption spectrum and emission spectrum of the obtained toluene solution are shown in Figure 15. The horizontal axis represents the wavelength, and the vertical axis represents the absorption intensity and emission intensity.

[0250] From the results in FIG. 15, in the toluene solution of 4,8mDBtP2Bqn, absorption peaks were observed near 369 nm, 351 nm, 333 nm, and 288 nm, and an emission wavelength peak was observed near 405 nm.

[0251] The spectra of the thin films were measured using samples prepared by vacuum deposition of 4,8mDBtP2Bqn on a quartz substrate. The absorption spectra were measured using an ultraviolet-visible spectrophotometer (U4100, Hitachi High-Technologies Corporation), and the emission spectra were measured using a fluorometer (FS920, Hamamatsu Photonics, Inc.). The absorption and emission spectra of the solid thin films are shown in Figure 16. The horizontal axis represents the wavelength, and the vertical axis represents the absorption intensity and emission intensity.

[0252] As shown in FIG. 16, in the solid thin film of 4,8mDBtP2Bqn, absorption peaks were observed near 373 nm, 336 nm, and 288 nm, and an emission wavelength peak was observed near 421 nm. EXAMPLES

[0253] Example 1 In this example, a light-emitting device according to one embodiment of the present invention described in the embodiment will be described. The structural formulae of organic compounds used in this example are shown below.

[0254] [ka]

[0255] (Method of manufacturing light-emitting devices) 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 area of ​​the electrode was 2 mm×2 mm.

[0256] Next, as a pretreatment for forming a light-emitting device 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.

[0257] 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 then the substrate was allowed to cool for about 30 minutes.

[0258] 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 was facing downward. Then, 4,4',4''-(benzene-1,3,5-triyl)tri(dibenzothiophene) (abbreviation: DBT3P-II) represented by the above structural formula (i) and molybdenum oxide were co-deposited on the first electrode 101 by a deposition method using resistance heating to a thickness of 60 nm in a weight ratio of 2:1 (=DBT3P-II:molybdenum oxide), to form a hole injection layer 111.

[0259] Next, 4-phenyl-4'-(9-phenylfluoren-9-yl)triphenylamine (abbreviation: BPAFLP) represented by the above structural formula (ii) was deposited on the hole injection layer 111 to form a hole transport layer 112 with a thickness of 20 nm.

[0260] Next, 4,8-bis[3-(dibenzothiophen-4-yl)phenyl]benzo[h]quinazoline (abbreviation: 4,8mDBtP2Bqn) represented by the above structural formula (iii) and N-(1,1'-biphenyl-4-yl)-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-9,9-dimethyl-9H-fluoren-2-amine (abbreviation: The light-emitting layer 113 was formed by co-evaporating 40 nm of 4,8mDBtP2Bqn:PCBBiF and (acetylacetonato)bis(4,6-diphenylpyrimidinato)iridium(III) (abbreviation: [Ir(dppm)2(acac)]) represented by the above structural formula (v) in a weight ratio of 0.75:0.25:0.075 (=4,8mDBtP2Bqn:PCBBiF:[Ir(dppm)2(acac)]).

[0261] Then, 4,8mDBtP2Bqn was evaporated onto the light-emitting layer 113 to a thickness of 20 nm, and then 2,9-di(2-naphthyl)-4,7-diphenyl-1,10-phenanthroline (abbreviation: NBPhen) represented by the above structural formula (vi) was evaporated onto the light-emitting layer 113 to a thickness of 15 nm to form the electron transport layer 114.

[0262] After forming the electron transport layer 114, lithium fluoride (LiF) was evaporated to a thickness of 1 nm 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 device 1 of this embodiment.

[0263] The element structure of the light emitting device 1 is summarized in the table below.

[0264] [Table 1]

[0265] The above-mentioned light-emitting device 1 was sealed with a glass substrate in a glove box with a nitrogen atmosphere so that the light-emitting device was not 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 device 1 were measured.

[0266] The luminance-current density characteristics of the light-emitting device 1 are shown in Fig. 17, the current efficiency-luminance characteristics in Fig. 18, the luminance-voltage characteristics in Fig. 19, the current-voltage characteristics in Fig. 20, the external quantum efficiency-luminance characteristics in Fig. 21, and the emission spectrum in Fig. 22. 2 The main characteristics of the area are shown in Table 2.

[0267] [Table 2]

[0268] 17 to 22 show that the light-emitting device 1 of one embodiment of the present invention is an EL device with high emission efficiency. [Explanation of symbols]

[0269] 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 Electronic Relay Layer 119 Electron injection buffer layer 400 Substrates 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 Drive circuit section (gate line drive circuit) 604 Sealing substrate 605 Sealing material 607 Space 608 Wiring 609 FPC (Flexible Printed Circuit) 610 Element Substrate 611 Switching FET 612 Current Control FET 613 First electrode 614 Insulation 616 EL layer 617 Second Electrode 618 Light Emitting Devices 951 Board 952 Electrode 953 Insulation Layer 954 Partition layer 955 EL layer 956 Electrode 1001 Board 1002 Undercoat insulating 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 Bulkhead 1028 EL layer 1029 Second electrode 1031 Sealing substrate 1032 Sealing material 1033 Transparent substrate 1034R Red color layer 1034G Green colored layer 1034B Blue colored layer 1035 Black Matrix 1036 Overcoat layer 1037 Third interlayer insulating film 1040 Pixel section 1041 Drive circuit section 1042 Periphery 2001 Case 2002 light source 2100 Robot 2110 Arithmetic equipment 2101 Illuminance sensor 2102 Microphone 2103 Upper Camera 2104 Speaker 2105 Display 2106 Lower Camera 2107 Obstacle Sensor 2108 Moving mechanism 3001 Lighting equipment 5000 cabinet 5001 Display section 5002 Display section 5003 Speaker 5004 LED Lamp 5006 Connection terminal 5007 Sensor 5008 Microphone 5012 Support part 5013 Earphones 5100 Cleaning robot 5101 Display 5102 Camera 5103 Brush 5104 Operation button 5150 Portable Information Terminal 5151 Case 5152 Display area 5153 Bend 5120 Garbage 5200 display area 5201 Display area 5202 Display area 5203 Display area 7101 Case 7103 Display section 7105 Stand 7107 Display section 7109 Operation key 7110 Remote control device 7201 Main unit 7202 Case 7203 Display section 7204 Keyboard 7205 External connection port 7206 Pointing Device 7210 Second display unit 7401 Case 7402 Display section 7403 Operation button 7404 External connection port 7405 Speaker 7406 Mike 9310 Mobile Information Terminal 9311 Display Panel 9313 Hinge 9315 Case

Claims

1. An organic compound represented by the following general formula (G1): 【Chemistry 1】 (In the above general formula (G1), A represents a substituted or unsubstituted dibenzothiophenyl group, L １ R represents any one of a single bond, a substituted or unsubstituted phenylene group, and a substituted or unsubstituted biphenyldiyl group. １ and R ２ each independently represents any one of hydrogen and an alkyl group having 1 to 6 carbon atoms; Ar １ ~Ar ４ any one of which is a group represented by the following general formula (g1), and the rest each independently represent any one of hydrogen and an alkyl group having 1 to 6 carbon atoms. 【Chemistry 2】 (In the above general formula (g1), B represents a substituted or unsubstituted dibenzothiophenyl group, L ２ represents any one of a substituted or unsubstituted phenylene group and a substituted or unsubstituted biphenyldiyl group.

2. In claim 1, The Ar ３ is a group represented by general formula (g1).

3. An organic compound represented by the following general formula (G1): 【Chemistry 3】 (In the above general formula (G1), A represents a substituted or unsubstituted dibenzothiophenyl group, L 1 represents a substituted or unsubstituted phenylene group, R 1 and R 2 each independently represent any one of hydrogen and an alkyl group having 1 to 6 carbon atoms, Ar 1 , Ar 2 and Ar 4 each independently represent any one of hydrogen and an alkyl group having 1 to 6 carbon atoms, and Ar 3 is a group represented by the following general formula (g1).) 【Chemistry 4】 (In the above general formula (g1), B represents a substituted or unsubstituted dibenzothiophenyl group, and L 2 represents a substituted or unsubstituted phenylene group.)

4. In any one of claims 1 to 3, Said L １ An organic compound in which is an m-phenylene group.

5. In any one of claims 1 to 3, Said L ２ An organic compound in which is an m-phenylene group.

6. In any one of claims 1 to 5, The organic compound, wherein R 1 and R 2 are each independently hydrogen.

7. In any one of claims 1 to 6, The organic compound in which Ar 1 , Ar 2 and Ar 4 are each independently hydrogen.

8. An organic compound represented by the following structural formula (100): 【Chemistry 5】

9. A light-emitting device comprising an organic compound according to any one of claims 1 to 8.

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