Light-emitting element and light-emitting device

Abstract

To provide an organic compound as a novel substance, having a low HOMO Level and a high hole transport property.SOLUTION: An organic compound is represented by General Formula (G1). (In formula, Ar1 represents a substituted or non-substituted fluorenyl group, Ar2 represents a substituted or non-substituted aryl group with 6 to 13 carbons, A1 represents any one of a substituted or non-substituted dibenzofuranyl group and a substituted or non-substituted dibenzothiophenyl group. When Ar1, Ar2, and A1 have the substituent, the substituent is an alkyl group with 1 to 4 carbons or an aryl group with 6 to 13 carbons. As the aryl group, a heteroaryl group is not included. The substituents may be coupled together to form a ring.)SELECTED DRAWING: None

Description

[Technical Field]

[0001] One embodiment of the present invention relates to an organic compound. The present invention relates to a lighting device, an electronic device, and a lighting device. [Background technology]

[0002] In recent years, electroluminescence (EL) The basic structure of these light-emitting devices is as follows: The device has a layer containing a light-emitting substance sandwiched between a pair of electrodes. This allows light emission from the luminescent substance.

[0003] These light-emitting elements are self-luminous, so the pixels are more visible than those of LCDs. It has the advantage of being simple and does not require a backlight, making it suitable for use as a flat panel display element. Furthermore, such a light-emitting element can be manufactured to be thin and lightweight. Another major advantage is that it has an extremely fast response time.

[0004] These light emitting elements can be formed into a film, so that surface light emission can be obtained. Therefore, a large-area element utilizing surface light emission can be easily formed. This is something that cannot be achieved with point light sources such as incandescent bulbs and LEDs, or linear light sources such as fluorescent lamps. Because of this unique characteristic, it is highly useful as a surface light source for lighting and other applications.

[0005] The light-emitting element that utilizes electroluminescence is either an organic compound or They can be broadly classified according to whether they are organic or inorganic compounds. In the case of an organic EL element having a layer containing the organic compound, applying a voltage to the light emitting element As a result, electrons are injected from the cathode and holes are injected from the anode into the layer containing the organic compound. The injected electrons and holes then bring the organic compound to an excited state, causing a current to flow. The light is emitted from an excited organic compound.

[0006] The types of excited states that organic compounds can form are singlet excited states and triplet excited states. It is possible to obtain a singlet excited state (S * ) is emitted from the triplet excited state (T * ) from The light is called phosphorescence.

[0007] Regarding such light-emitting devices, there are material-dependent issues in improving the device characteristics. To overcome these problems, improvements to device structures and material development are being carried out. In Patent Document 1, an organic compound that can be used to form a light-emitting element with high luminous efficiency is disclosed. As a compound, a carbazole derivative having high hole transporting properties is disclosed. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] Japanese Patent Application Laid-Open No. 2009-298767 Summary of the Invention [Problem to be solved by the invention]

[0009] As described above, in order to improve the characteristics of the light-emitting element, it is necessary to use an active material having characteristics suitable for the light-emitting element. In one aspect of the present invention, the development of organic compounds having a low HOMO level and a hole (hole) Furthermore, the present invention provides a novel organic compound having a transport property. By using organic compounds, it is possible to provide a light-emitting element with high luminous efficiency, and further, to achieve a short wavelength (450 The present invention provides a light-emitting device that emits light in the wavelength range of about 500 nm to 550 nm with high efficiency. [Means for solving the problem]

[0010] One aspect of the present invention is a novel compound having a low HOMO level and hole transporting properties. Specifically, it is an organic compound represented by the following general formula (G1).

[0011] [ka]

[0012] However, in the formula, Ar 1 represents a substituted or unsubstituted fluorenyl group, and Ar 2 is replaced or an unsubstituted aryl group having 6 to 13 carbon atoms, and A 1 is a substituted or unsubstituted di a benzofuranyl group, or a substituted or unsubstituted dibenzothiophenyl group; In addition, Ar 1 , Ar 2 and A 1 When the group has a substituent, the substituent has 1 to 10 carbon atoms. The aryl group is an alkyl group having 4 carbon atoms or an aryl group having 6 to 13 carbon atoms. Heteroaryl groups are not included. In addition, the substituents may be bonded to each other to form a ring.

[0013] Another embodiment of the present invention is an organic compound represented by the following general formula (G2).

[0014] [ka]

[0015] However, in the formula, Ar 3 represents a substituted or unsubstituted aryl group having 6 to 13 carbon atoms, and A 2 is a substituted or unsubstituted dibenzofuranyl group, or a substituted or unsubstituted dibenzo R represents one of the thiophenyl groups. 1 ~R 9 is hydrogen or carbon number 1-4 represents an alkyl group or an aryl group having 6 to 13 carbon atoms, and Ar 3 and A 2 has a substituent If so, Ar 3 and A 2 The substituent is an alkyl group having 1 to 4 carbon atoms or an alkyl group having 6 to 10 carbon atoms. The aryl group is defined as an aryl group of the formula 13. Note that the aryl group does not include a heteroaryl group. The substituents may be bonded to each other to form a ring.

[0016] Another embodiment of the present invention is an organic compound represented by the following general formula (G3).

[0017] [ka]

[0018] However, in the formula, Ar 4 represents a substituted or unsubstituted biphenyl group, and A 3 is replaced or unsubstituted dibenzofuranyl group, or substituted or unsubstituted dibenzothiophenyl group It represents one of the following. 11 ~R 19 is hydrogen or an alkyl group having 1 to 4 carbon atoms or an aryl group having 6 to 13 carbon atoms, Ar 4 and A 3 When has a substituent, Ar 4 and A 3The substituent is an alkyl group having 1 to 4 carbon atoms or an aryl group having 6 to 13 carbon atoms. The aryl group does not include heteroaryl groups. The shi may be bonded to form a ring.

[0019] Another embodiment of the present invention is an organic compound represented by the following general formula (G4).

[0020] [ka]

[0021] In the formula, X represents oxygen or sulfur, and R 21 and R 22 is hydrogen or carbon It represents an alkyl group having 1 to 4 carbon atoms or an aryl group having 6 to 13 carbon atoms. It does not include heteroaryl groups. 21 and R 22 may be bonded to form a ring stomach.

[0022] Another embodiment of the present invention is an organic compound represented by the following structural formula (100):

[0023] [ka]

[0024] One embodiment of the present invention is represented by the above general formulae (G1) to (G4) and structural formula (100). The organic compounds are all substituted or unsubstituted dibenzofuranyl groups, or substituted or unsubstituted dibenzofuranyl groups. has a structure in which an unsubstituted dibenzothiophenyl group is directly bonded to the nitrogen of an amine. Therefore, it is possible to form organic compounds with low HOMO levels and high hole transport properties. can.

[0025] Note that the organic compound according to one embodiment of the present invention has a low HOMO level and a hole ( In addition to being a novel organic compound with hole transport properties, it can also be excited with other organic compounds. It is possible to form an exciplex. In this case, hole transport occurs due to the influence of the HOMO level of the organic compound according to one embodiment of the present invention. This allows the formation of high-energy exciplexes while maintaining the transmittance. The same system can be used with a short wavelength emission wavelength (for example, in the range between about 450 nm and about 550 nm). The present invention is particularly applicable to the case where the compound contains a light-emitting substance (guest material) that converts triplet excitation energy into light emission. It will be effective.

[0026] Therefore, the exciplex formed by combining with the organic compound according to one embodiment of the present invention and a short wavelength (e.g., in the range between about 450 nm and about 550 nm) By forming a light-emitting element having a light-emitting layer containing a guest material, A light emitting element can be provided.

[0027] Furthermore, one embodiment of the present invention is not only a light-emitting device having a light-emitting element, but also an electric device having a light-emitting device. The term "light-emitting device" as used herein also includes a child device and a lighting device. This refers to an image display device or a light source (including lighting equipment). For example, FPC (Flexible printed circuit) or T Module with CP (Tape Carrier Package) attached, TC A module with a printed wiring board at the end of P, or a light emitting element with COG (Chip On Glass) The "On Glass" method allows all modules with ICs (integrated circuits) directly mounted to be illuminated. This shall be included in the device. [Effects of the Invention]

[0028] According to one aspect of the present invention, a novel compound having a low HOMO level and hole transporting properties is provided. Furthermore, the novel organic compound according to one embodiment of the present invention can be provided. By using this, it is possible to produce light-emitting elements with high luminous efficiency, especially short wavelengths (450 nm to 550 nm It is possible to provide a light-emitting element that emits light with high efficiency (in the range of about 1000 nm). It is possible to provide a light-emitting element, a light-emitting device, an electronic device, or a lighting device with low power consumption. [Brief explanation of the drawings]

[0029] [Figure 1] 1A to 1C illustrate a structure of a light-emitting element. [Figure 2] 1A to 1C illustrate a structure of a light-emitting element. [Figure 3] 1A and 1B illustrate a light-emitting device. [Figure 4] 1A and 1B are diagrams illustrating electronic devices. [Figure 5] 1A and 1B are diagrams illustrating electronic devices. [Figure 6] FIG. [Figure 7] 1H-NMR chart of the organic compound shown in structural formula (100). [Figure 8] UV-visible absorption and emission spectra of the organic compound represented by structural formula (100). [Figure 9] FIG. 1 shows the results of LC-MS measurement of the organic compound represented by structural formula (100). [Figure 10] 1A to 1C are diagrams illustrating a light-emitting element according to an embodiment. [Figure 11] FIG. 10 is a graph showing current density-luminance characteristics of the light-emitting element 1. [Figure 12] FIG. 10 shows voltage-luminance characteristics of the light-emitting element 1. [Figure 13] FIG. 10 shows luminance vs. current efficiency characteristics of Light-emitting Element 1. [Figure 14] FIG. 2 shows voltage-current characteristics of the light-emitting element 1. [Figure 15] FIG. 2 shows an emission spectrum of the light-emitting element 1. [Figure 16] FIG. 10 shows the reliability of the light-emitting element 1. [Figure 17] Figure showing the emission spectra of the mixed film (A), the mixed film (B), the film of the organic compound (FrBiF) shown in structural formula (100), the film of 2-[3'-(dibenzothiophen-4-yl)biphenyl-3-yl]dibenzo[f,h]quinoxaline (2mDBTBPDBq-II), and the film of N-(1,1'-biphenyl-4-yl)-9,9-dimethyl-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-9H-fluoren-2-amine (PCBBiF). [Figure 18] 1H-NMR chart of the organic compound shown in structural formula (103). [Figure 19] UV-visible absorption and emission spectra of the organic compound shown in structural formula (103). [Figure 20] FIG. 1 shows the results of LC-MS measurement of the organic compound represented by structural formula (103). [Figure 21] FIG. 10 shows voltage-luminance characteristics of Light-emitting element 2. [Figure 22] FIG. 10 shows luminance-current efficiency characteristics of Light-emitting Element 2. [Figure 23] FIG. 10 is a graph showing voltage-current characteristics of the light-emitting element 2. [Figure 24] FIG. 10 shows an emission spectrum of the light-emitting element 2. DETAILED DESCRIPTION OF THE INVENTION

[0030] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The present invention is not limited to the above description, and the embodiments and details thereof may be modified without departing from the spirit and scope of the present invention. Therefore, the present invention is based on the following embodiments and examples. It should not be construed as being limited to the contents of the examples.

[0031] (Embodiment 1) In this embodiment, an organic compound which is one embodiment of the present invention will be described.

[0032] An organic compound according to one embodiment of the present invention is an organic compound represented by the following general formula (G1): .

[0033] [ka]

[0034] In general formula (G1), Ar 1 represents a substituted or unsubstituted fluorenyl group, and A r 2 represents a substituted or unsubstituted aryl group having 6 to 13 carbon atoms, and A 1 is a replacement or is an unsubstituted dibenzofuranyl group, or a substituted or unsubstituted dibenzothiophenyl group. It represents one of the following. 1 , Ar 2 and A 1 However, if the group has a substituent, the substituent is The alkyl group has 1 to 4 carbon atoms, or the aryl group has 6 to 13 carbon atoms. The aryl group does not include heteroaryl groups. In addition, the substituents may be bonded to each other to form a ring. Good too.

[0035] Further, the organic compound according to one embodiment of the present invention is an organic compound represented by the following general formula (G2): is.

[0036] [ka]

[0037] In general formula (G2), Ar 3 is a substituted or unsubstituted aryl having 6 to 13 carbon atoms represents a group, and A2 is a substituted or unsubstituted dibenzofuranyl group, or a substituted or unsubstituted and R represents one of the substituted dibenzothiophenyl groups. 1 ~R 9 is hydrogen or carbon represents an alkyl group having 1 to 4 carbon atoms or an aryl group having 6 to 13 carbon atoms, and Ar 3 and A 2 When has a substituent, Ar 3 and A 2 The substituent is an alkyl group having 1 to 4 carbon atoms, or is an aryl group having 6 to 13 carbon atoms. The aryl group is a heteroaryl group. In addition, the substituents may be bonded to each other to form a ring.

[0038] Further, the organic compound according to one embodiment of the present invention is an organic compound represented by the following general formula (G3): is.

[0039] [ka]

[0040] In general formula (G3), Ar 4 represents a substituted or unsubstituted biphenyl group, and A 3 is a substituted or unsubstituted dibenzofuranyl group, or a substituted or unsubstituted dibenzothia R represents either one of the phenyl groups. 11 ~R 19 is hydrogen or carbon number 1-4 or an aryl group having 6 to 13 carbon atoms, and Ar 4 and A 3 is a substituent If present, Ar 4 and A 3 The substituent is an alkyl group having 1 to 4 carbon atoms or a group having 6 carbon atoms. The aryl group is an aryl group having a structure of from 1 to 13. The aryl group does not include a heteroaryl group. In addition, the substituents may be bonded to each other to form a ring.

[0041] An organic compound according to one embodiment of the present invention is an organic compound represented by the following general formula (G4): .

[0042] [ka]

[0043] In general formula (G4), X represents oxygen or sulfur, and R 21 and R 22 is hydrogen or an alkyl group having 1 to 4 carbon atoms, or an aryl group having 6 to 13 carbon atoms. The aryl group does not include a heteroaryl group. 21 and R 22 is bonded to a ring may be formed.

[0044] In addition, Ar in the above general formula (G1) 1 and Ar 2 , the general formulas (G2) and (G3) Ar 3 and Ar 4 When the alkyl group has a substituent, the specific examples of the alkyl group having 1 to 4 carbon atoms as the substituent include: Examples include methyl, ethyl, propyl, isopropyl, butyl, sec-butyl, butyl group, isobutyl group, tert-butyl group, etc., and aryl groups having 6 to 13 carbon atoms. Specific examples of the alkyl group include a phenyl group, a tolyl group, a xylyl group, a mesityl group, a biphenyl group, and a naphthalene group. Examples of the substituents include butyl and fluorenyl groups. In addition, the substituents may be bonded to each other to form a ring. A spirofluorenyl group is considered to be a ring formed by the substituents being linked together (i.e., That is, in the 9,9-diphenylfluorenyl group, two phenyl groups are bonded to form a ring. The resulting compound is the spirofluorenyl group.

[0045] In addition, Ar in the above general formula (G1) 2 , Ar of the above general formula (G2) 3 Specific examples include: Examples of the substituents include those shown in structural formulas (1-1) to (1-11). Structural formula (1-11) is Ar 2 , and Ar 3 is a specific example of a case where the structural formula (1-10) shows a structure in which the substituents are bonded to each other to form a ring.

[0046] [ka]

[0047] In addition, R in the above general formula (G2) 1 ~R 9 , R in the above general formula (G3) 11 ~R 19 ,the above R in general formula (G4) 21 and R 22 Specific examples of alkyl groups having 1 to 4 carbon atoms include: is a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a sec-butyl group, Examples of the aryl group having 6 to 13 carbon atoms include an isobutyl group and a tert-butyl group. Examples include a phenyl group, a tolyl group, a xylyl group, a mesityl group, a biphenyl group, and a naphthyl group. and fluorenyl groups. In addition, the substituents may be bonded to each other to form a ring, A spirofluorenyl group is considered to be a ring formed by the substituents attached (i.e., 9, 9-diphenylfluorenyl group in which two phenyl groups are bonded to form a ring is a spirofluorenyl group.

[0048] In addition, A in the above general formula (G1)1 , A in the above general formula (G2) 2 , the general formula (G3) A 3 Specific examples of the alkyl group having 1 to 4 carbon atoms, which is a substituent when the group has a substituent, include: is a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a sec-butyl group, Examples of the aryl group having 6 to 13 carbon atoms include an isobutyl group and a tert-butyl group. Examples include a phenyl group, a tolyl group, a xylyl group, a mesityl group, a biphenyl group, and a naphthyl group. and fluorenyl groups.

[0049] Note that the organic compounds represented by the above general formulas (G1) to (G4) which are embodiments of the present invention are Both are substituted or unsubstituted dibenzofuranyl groups or substituted or unsubstituted dibenzo By using a structure in which the thiophenyl group is directly bonded to the nitrogen of the amine, the HOMO level is It has the advantage of being able to lower the temperature and increase the hole transport property.

[0050] Next, specific structural formulae of the organic compounds according to embodiments of the present invention will be shown below. Formulas (100) to (161). However, the present invention is not limited to these.

[0051] [ka]

[0052] [ka]

[0053] [ka]

[0054] [ka]

[0055] [ka]

[0056] [ka]

[0057] [ka]

[0058] The organic compounds represented by the structural formulas (100) to (161) have a low HOMO level. It is a novel organic compound that has low conductivity and hole transport properties. can form an exciplex with

[0059] Next, an example of a method for synthesizing an organic compound according to one embodiment of the present invention will be described. Various reactions can be applied to synthesize the organic compound of one embodiment of the present invention. Therefore, the synthesis method of the organic compound according to one embodiment of the present invention is not limited to the synthesis method described below.

[0060] <Method for Synthesizing an Organic Compound Represented by General Formula (G1) of One Embodiment of the Present Invention> An example of a method for synthesizing an organic compound represented by the following general formula (G1), which is one embodiment of the present invention, is shown below. and explain.

[0061] [ka]

[0062] In general formula (G1), Ar 1 represents a substituted or unsubstituted fluorenyl group. And Ar 2 represents a substituted or unsubstituted aryl group having 6 to 13 carbon atoms, and A 1 is replaced or unsubstituted dibenzofuranyl group, or substituted or unsubstituted dibenzothiophene It is to be noted that Ar 1 , Ar 2 and A 1 When has a substituent, The substituent is an alkyl group having 1 to 4 carbon atoms or an aryl group having 6 to 13 carbon atoms.

[0063] The synthesis scheme of the organic compound represented by general formula (G1) according to one embodiment of the present invention is shown below. A).

[0064] [ka]

[0065] In the synthesis scheme (A), Ar 1 represents a substituted or unsubstituted fluorenyl group Represents Ar 2 represents a substituted or unsubstituted aryl group having 6 to 13 carbon atoms. 1 teeth, A substituted or unsubstituted dibenzofuranyl group or a substituted or unsubstituted dibenzothiophene group X represents a halogen or a trifluoromethanesulfonic acid group. , preferably bromine or iodine. 1 , Ar 2 and A 1 has a substituent In this case, the substituent is an alkyl group having 1 to 4 carbon atoms or an aryl group having 6 to 13 carbon atoms. Has.

[0066] As shown in the above synthesis scheme (A), a secondary diarylamine (a1) and a halogenated by coupling with aryl (a2) using a metal catalyst in the presence of a base, An organic compound represented by general formula (G1) can be obtained.

[0067] [For Hartwick-Buchwald reaction] In the above synthesis scheme (A), the palladium catalyst that can be used is bis(trimethylsilyl)methyl. (dibenzylideneacetone)palladium(0), palladium(II) acetate, etc. The ligand of the palladium catalyst is tri(tert-butyl)phosphine or tri(n -hexyl)phosphine, tricyclohexylphosphine, etc. The catalysts and their ligands that can be used are not limited to these.

[0068] The base that can be used in the synthesis scheme (A) is sodium te Examples of bases that can be used include organic bases such as rt-butoxide and inorganic bases such as potassium carbonate. Examples of solvents that can be used include toluene, xylene, benzene, and tetrahydrofuran. However, the bases and solvents that can be used are not limited to these.

[0069] [When performing Ullmann reaction] In the synthetic scheme (A), R 101 and R 102 are each independently a halogen or represents an acetyl group, and examples of halogen include chlorine, bromine, and iodine. 1 01 is iodine, or copper(I) iodide, 102 Copper acetate (I) I) is preferred. The copper compound used in the reaction is not limited to these. In addition to the compound, copper can be used. Examples of the base that can be used include potassium carbonate. It is not something that can be done.

[0070] In the synthesis scheme (A), the solvent that can be used is 1,3-dimethyl-3 ,4,5,6-tetrahydro-2(1H)pyrimidinone (DMPU), toluene, xylene Examples of solvents that can be used include benzene, ethanol, etc. However, the solvents that can be used are not limited to these. In the Ullmann reaction, the desired product can be obtained in a shorter time and with a higher yield when the reaction temperature is 100°C or higher. Therefore, it is preferable to use DMPU, xylene, or toluene, which have high boiling points. Furthermore, since the reaction temperature is more preferably 150°C or higher, DMP is more preferably used. Use U.

[0071] In the above manner, the organic compound of one embodiment of the present invention can be synthesized.

[0072] Furthermore, by using the organic compound of one embodiment of the present invention, a light-emitting element and an emitter element with high emission efficiency can be obtained. It is possible to realize an optical device, an electronic device, or a lighting device. An element, a light-emitting device, an electronic device, or a lighting device can be realized.

[0073] The structure described in this embodiment mode can be used in appropriate combination with structures described in other embodiments. This can be done.

[0074] (Embodiment 2) In this embodiment, as one embodiment of the present invention, the organic compound described in Embodiment 1 is used as a light-emitting layer. The light-emitting element used will be explained with reference to FIG.

[0075] The light-emitting element shown in this embodiment has a pair of electrodes (first electrode (anode) 1) as shown in FIG. An EL layer 102 including a light-emitting layer 113 is sandwiched between the first electrode 101 and the second electrode (cathode) 103. The EL layer 102 includes a hole injection layer 111, a hole injection layer 112, a light emitting layer 113, and a hole injection layer 114. or hole) transport layer 112, electron transport layer 114, electron injection layer 115, charge generation layer (E The light-emitting layer 113 is formed by containing a first organic compound and a second organic compound. It contains an organic compound and a luminescent substance (guest material) that converts triplet excitation energy into luminescence. It is composed of:

[0076] By applying a voltage to such a light emitting element, light is injected from the first electrode 101 side. The holes injected from the second electrode 103 side and the electrons injected from the second electrode 103 side are recombined in the light-emitting layer 113. The first organic compound and the second organic compound form an exciplex. The guest material emits light due to the energy transfer from the first The organic compound or the second organic compound may be the organic compound described in Embodiment 1 as one aspect of the present invention. Organic compounds can be used.

[0077] The hole injection layer 111 in the EL layer 102 is made of a material having a high hole transporting property and an acceptor. The layer contains an acceptor material, and electrons are transferred from a material with high hole transporting properties to the acceptor material. Therefore, holes are generated from the hole injection layer 111. Holes are injected into the light-emitting layer 113 through the transport layer 112 .

[0078] The charge generation layer (E) 116 contains a material having a high hole transporting property and a material having an acceptor property. The acceptor substance extracts electrons from the substance with high hole transport properties. Therefore, the extracted electrons pass through the electron transport layer 114 from the electron injection layer 115 having electron injection properties. The electrons are injected into the light-emitting layer 113 via the electron transport layer 114.

[0079] A specific example of manufacturing the light-emitting element described in this embodiment mode will be described below.

[0080] The first electrode (anode) 101 and the second electrode (cathode) 103 are made of a metal, an alloy, an electrically conductive material, or the like. Conductive compounds and mixtures thereof can be used. Indium-tin oxide (ITO), silicon or silicon oxide Indium oxide-tin oxide, indium oxide-zinc oxide (Indium Zi nc Oxide), indium oxide containing tungsten oxide and zinc oxide, gold (A u), platinum (Pt), nickel (Ni), tungsten (W), chromium (Cr), molyb Mo, iron (Fe), cobalt (Co), copper (Cu), palladium (Pd), titanium In addition to titanium (Ti), elements belonging to the first or second group of the periodic table, namely lithium (L i) and alkali metals such as cesium (Cs), calcium (Ca), and strontium Alkaline earth metals such as Sr, magnesium (Mg), and alloys containing these (Mg Rare earth metals such as Ag, AlLi), europium (Eu), ytterbium (Yb) and The first electrode (anode) and the alloy containing the first electrode, graphene, etc. can be used. The first electrode (cathode) 101 and the second electrode (cathode) 103 are formed by, for example, sputtering or vapor deposition (vacuum The film can be formed by a method such as evaporation.

[0081] The hole injection layer 111, the hole transport layer 112, and the charge generation layer (E) 116 are formed of a hole transport material. An example of a substance with high transportability is 4,4'-bis[N-(1-naphthyl)-N-phenyl]. N,N'-bis(3-methylamino)biphenyl (abbreviated as NPB or α-NPD) phenyl)-N,N'-diphenyl-[1,1'-biphenyl]-4,4'-diamine( Abbreviation: TPD), 4,4',4''-tris(carbazol-9-yl)triphenyl amine (abbreviation: TCTA), 4,4',4''-tris(N,N-diphenylamino)tri Phenylamine (abbreviation: TDATA), 4,4',4''-tris[N-(3-methylphenyl) 4,4'-phenyl-N-phenylamino]triphenylamine (abbreviation: MTDATA) -Bis[N-(spiro-9,9'-bifluoren-2-yl)-N-phenylamino]bi Aromatic amine compounds such as phenyl (abbreviation: BSPB), 3-[N-(9-phenylcarbamoyl) [9-phenylcarbazole (abbreviation: PC zPCA1), 3,6-bis[N-(9-phenylcarbazol-3-yl)-N-phenyl] Nylamino]-9-phenylcarbazole (abbreviation: PCzPCA2), 3-[N-(1- naphthyl)-N-(9-phenylcarbazol-3-yl)amino]-9-phenylcarbazol Other examples include 4,4'-di(N-carbazole) 1,3,5-tris[4-(N-carbazolyl)biphenyl (abbreviation: CBP), phenyl]benzene (abbreviation: TCPB), 9-[4-(10-phenyl-9-anthracene carbazole derivatives such as [(9H-phenyl)phenyl]-9H-carbazole (abbreviation: CzPA), etc. The materials mentioned here are mainly 10 -6 cm 2 Hole transfer above / Vs However, other than these, any material that has a higher hole transporting property than electron transporting property can be used. In addition, the organic compound shown in Embodiment 1, which is one embodiment of the present invention, may be used. Because of its high hole transporting property, the hole injection layer 111, the hole transport layer 112, and the charge generating layer (E) 116 can be suitably used.

[0082] Furthermore, poly(N-vinylcarbazole) (abbreviation: PVK), poly(4-vinyltriflate) Phenylamine) (abbreviation: PVTPA), poly[N-(4-{N'-[4-(4-diphenyl (N'-phenylamino)phenyl]phenyl-N'-phenylamino}phenyl)methacrylamide (abbreviation: PTPDMA) Poly[N,N'-bis(4-butylphenyl)-N,N'-bis (phenyl)benzidine (abbreviated as Poly-TPD) It is also possible.

[0083] In addition, the acceptor material used in the hole injection layer 111 and the charge generation layer (E) 116 Examples of the oxides include oxides of metals belonging to groups 4 to 8 in the periodic table. Specifically, molybdenum oxide is particularly preferred.

[0084] The light-emitting layer 113 may be formed by containing a light-emitting substance. It is preferable to form the layer using an organic compound (host material) that disperses the host material.

[0085] Here, in order to increase the efficiency of energy transfer from the host material to the guest material, The Förster mechanism (dipole-dipole interaction) and the The emission spectrum of the host material ( When discussing energy transfer from the singlet excited state, the fluorescence spectrum is When discussing the energy transfer from the guest material, the phosphorescence spectrum is used. More specifically, it is preferable that the overlap with the absorption band on the longest wavelength (lowest energy) side is large. However, it is usually desirable to adjust the fluorescence spectrum of the host material to the longest wavelength ( It is difficult to overlap the absorption band on the low energy side because Therefore, the phosphorescence spectrum of the host material is on the longer wavelength (lower energy) side than the fluorescence spectrum. Therefore, the T1 level of the host material is lower than the T1 level of the guest material, This is because energy is not transferred efficiently from the material to the guest material. Therefore, if the T1 level of the host material is designed to be higher than the T1 level of the guest material, The fluorescence spectrum of the photoresist material is shifted to the short wavelength (high energy) side. The spectrum does not overlap with the absorption band of the guest material on the longest wavelength (lowest energy) side. The fluorescence spectrum of the host material is determined by the absorption spectrum of the longest wavelength (lowest energy) of the guest material. The overlapping of the bands maximizes the energy transfer from the singlet excited state of the host material. It is usually difficult.

[0086] Therefore, in this embodiment, an exciplex (also called an exciplex) is used as the host material. In this case, it is preferable to use a plurality of organic compounds that form the light-emitting layer 113. When carriers (electrons and holes) recombine, the host material is a plurality of organic compounds (e.g. The first organic compound and the second organic compound form an exciplex. 113, the fluorescence spectrum of the first organic compound and the fluorescence spectrum of the second organic compound The spectrum of the exciplex is not observed, and the emission spectrum of the exciplex located on the longer wavelength side is obtained. As a result, the overlap between the emission spectrum of the exciplex and the absorption spectrum of the guest material becomes large. Thus, by selecting the first and second organic compounds, the energy from the singlet excited state can be It is possible to maximize the energy transfer. It is thought that energy transfer occurs from

[0087] The guest materials include phosphorescent compounds (organic metal complexes, etc.) and thermally activated delayed fluorescence ( Preferably, the material is a TADF material.

[0088] Specific examples of the organometallic complex include bis[2-(4',6'-difluoro Phenyl)pyridinato-N,C 2’ ]iridium(III) tetrakis(1-pyrazolyl) ) borate (abbreviation: FIr6), bis[2-(4',6'-difluorophenyl)pyridin Nat-N,C 2’ ]Iridium(III) picolinate (abbreviation: FIrpic), bis{ 2-[3',5'-bis(trifluoromethyl)phenyl]pyridinato-N,C 2’}stomach Iridium(III) picolinate (abbreviation: Ir(CF3ppy)2(pic)), bis[ 2-(4',6'-difluorophenyl)pyridinato-N,C 2’ ] Iridium (III ) acetylacetonate (abbreviated as FIracac), tris(2-phenylpyridinato) Iridium(III) (abbreviation: Ir(ppy)3), bis(2-phenylpyridinato)i Iridium(III) acetylacetonate (abbreviation: Ir(ppy)2(acac)), Iridium(III) acetylacetonate (benzo[h]quinolinato) (bzq)2(acac)), bis(2,4-diphenyl-1,3-oxazolato-N, C 2’ ) Iridium(III) acetylacetonate (abbreviation: Ir(dpo)2(aca c)), bis{2-[4'-(perfluorophenyl)phenyl]pyridinato-N,C 2 ’}Iridium(III) acetylacetonate (abbreviation: Ir(p-PF-ph)2(a cac)), bis(2-phenylbenzothiazolato-N,C 2’ ) Iridium(III) Acetylacetonate (abbreviation: Ir(bt)2(acac)), bis[2-(2'-benzophenone] Zo[4,5-α]thienyl)pyridinato-N,C 3’ ]Iridium(III) acetylacetone Setonate (abbreviation: Ir(btp)2(acac)), bis(1-phenylisoquinolinone) To-N,C 2’ ) Iridium(III) acetylacetonate (abbreviation: Ir(piq)2 (acac)), (acetylacetonato)bis[2,3-bis(4-fluorophenyl) Quinoxalinato]iridium(III) (abbreviation: Ir(Fdpq)2(acac)), ( Acetylacetonato)bis(2,3,5-triphenylpyrazinate)iridium(III) ) (abbreviation: Ir(tppr)2(acac)), 2,3,7,8,12,13,17,1 8-octaethyl-21H,23H-porphyrin platinum(II) (abbreviation: PtOEP), Tris(acetylacetonato)(monophenanthroline)terbium(III) (abbreviation: Tb(acac)3(Phen)), tris(1,3-diphenyl-1,3-propanedi Onato)(monophenanthroline)europium(III) (abbreviation: Eu(DBM)3( Phen)), tris[1-(2-thenoyl)-3,3,3-trifluoroacetonate] (Monophenanthroline)europium(III) (abbreviation: Eu(TTA)3(Phen )) etc.

[0089] The first organic compound and the second organic compound, which are host materials, are exciplexes. A combination that generates a compound is preferable, and a compound that easily accepts electrons (electron trapping compound) ) and a compound that easily receives holes (hole-trapping compound). More preferable.

[0090] An example of a compound that readily accepts electrons is 2-[3-(dibenzothiophene-4 -yl)phenyl]dibenzo[f,h]quinoxaline (abbreviation: 2mDBTPDBq-II ), 2-[4-(3,6-diphenyl-9H-carbazol-9-yl)phenyl]dibenzyl benzo[f,h]quinoxaline (abbreviation: 2CzPDBq-III), 7-[3-(dibenzo[f,h]quinoxaline] Thiophen-4-yl)phenyl]dibenzo[f,h]quinoxaline (abbreviation: 7mDBT PDBq-II) and 6-[3-(dibenzothiophen-4-yl)phenyl]dibenzyl Examples include benzo[f,h]quinoxaline (abbreviation: 6mDBTPDBq-II).

[0091] As a compound that easily receives holes, the organic compound shown in the first embodiment is used. You can be there.

[0092] The first and second organic compounds that are host materials are not limited to the organic compounds described above. However, the present invention is not limited to the above, and the organic compound includes at least the organic compound shown in the first embodiment and forms an exciplex. In addition, the emission spectrum of the exciplex should be such that it is possible to obtain a combination that satisfies the absorption spectrum of the guest material. The emission spectrum of the exciplex overlaps with the longest wavelength of the guest material. It is sufficient if the wavelength is longer than the peak of the absorption band on the side.

[0093] The first organic compound is composed of a compound that readily accepts electrons and a compound that readily accepts holes. When a material and a second organic compound are combined, the carrier balance is controlled by the mixture ratio. Specifically, the ratio of the first organic compound to the second organic compound is in the range of 1:9 to 9:1. The surrounding area is preferred.

[0094] With the above structure, phosphorescence with high luminous efficiency can be obtained from the light-emitting layer 113.

[0095] The electron transport layer 114 is a layer containing a substance with a high electron transport property. Tris(8-quinolinolato)aluminum (abbreviation: Alq3), tris(4-methyl-8 -quinolinolato)aluminum (abbreviation: Almq3), bis(10-hydroxybenzo[ h]quinolinato)beryllium (abbreviation: BeBq2), bis(2-methyl-8-quinolinola Bis[2-(4-phenylphenolato)aluminum (abbreviation: BAlq), Droxy phenyl)benzoxazolato]zinc (abbreviation: Zn(BOX)2), bis[2-(2-phenyl)benzoxazolato]zinc Metal complexes such as [hydroxyphenyl]benzothiazolato]zinc (abbreviation: Zn(BTZ)2) Also, 2-(4-biphenylyl)-5-(4-tert-butyl phenyl)-1,3,4-oxadiazole (abbreviation: PBD), 1,3-bis[5-(p -tert-butylphenyl)-1,3,4-oxadiazol-2-yl]benzene( Abbreviation: OXD-7), 3-(4'-tert-butylphenyl)-4-phenyl-5-( 4''-biphenyl)-1,2,4-triazole (abbreviation: TAZ), 3-(4-ter t-butylphenyl)-4-(4-ethylphenyl)-5-(4-biphenylyl)-1, 2,4-triazole (abbreviation: p-EtTAZ), bathophenanthroline (abbreviation: BPh en), bathocuproine (abbreviation: BCP), 4,4'-bis(5-methylbenzoxa Heteroaromatic compounds such as (2-isopropyl-2-yl)stilbene (abbreviation: BzOs) can also be used. In addition, poly(2,5-pyridinediyl) (abbreviation: PPy), poly[(9,9- dihexylfluorene-2,7-diyl)-co-(pyridine-3,5-diyl)](abbreviation Name: PF-Py), poly[(9,9-dioctylfluorene-2,7-diyl)-co- (2,2'-bipyridine-6,6'-diyl)] (abbreviation: PF-BPy) Compounds can also be used. The substances mentioned here are mainly 10 -6 cm 2 / Vs or more It should be noted that if a substance has a higher electron transporting property than a hole transporting property, Materials other than these may be used for the electron-transporting layer 114 .

[0096] The electron transport layer 114 may be not only a single layer, but also a layer of two or more layers made of the above-mentioned materials. It may also be layered.

[0097] The electron injection layer 115 is a layer containing a substance with high electron injection properties. Lithium fluoride (LiF), cesium fluoride (CsF), calcium fluoride (CaF2) , lithium oxide (LiO x ) and the like, alkaline metals, alkaline earth metals, or the like Also, rare earth compounds such as erbium fluoride (ErF3) can be used. Metal compounds can be used. In addition, the above-mentioned materials constituting the electron transport layer 114 can be used. You can also be there.

[0098] Alternatively, the electron injection layer 115 may be formed by mixing an organic compound and an electron donor. Composite materials may also be used. Such composite materials are made by adding electrons to organic compounds via electron donors. In this case, the organic compound is In this case, it is preferable that the material is excellent in transporting the generated electrons. The electron transport layer 114 may be made of a material (metal complex, heteroaromatic compound, etc.). The electron donor may be any substance that exhibits electron donating properties to organic compounds. Specifically, alkali metals, alkaline earth metals and rare earth metals are preferred, and lithium, cesium, Examples of the elements include aluminum, magnesium, calcium, erbium, and ytterbium. Alkali metal oxides and alkaline earth metal oxides are preferred, and lithium oxide, calcium oxide, Examples of suitable cations include barium oxide and barium nitrate. It is also possible to use organic compounds such as tetrathiafulvalene (TTF). It is also possible to do so.

[0099] The hole injection layer 111, the hole transport layer 112, the light emitting layer 113, and the electron transport layer 11 4, the electron injection layer 115 and the charge generation layer (E) 116 are formed by deposition (including vacuum deposition). The layer can be formed by a method such as an ink jet method or a coating method.

[0100] The light-emitting element described above is formed by applying a voltage between the first electrode 101 and the second electrode 103. The potential difference causes a current to flow, and the holes and electrons recombine in the EL layer 102, causing light to be emitted. This light emission is transmitted to either the first electrode 101 or the second electrode 103. Therefore, the electric current is taken out through the first electrode 101 and the second electrode 10 Either one or both of the electrodes 3 is a light-transmitting electrode.

[0101] The light-emitting element described in this embodiment contains an organic compound according to one embodiment of the present invention in a light-emitting layer. Phosphorescence based on guest materials is achieved by energy transfer from exciplexes formed containing Therefore, a light emitting device with higher efficiency than conventional light emitting devices can be realized. do.

[0102] Note that the structure described in this embodiment mode may be used in appropriate combination with structures described in other embodiments. It shall be possible to do so.

[0103] (Embodiment 3) In this embodiment, as one embodiment of the present invention, a structure having a plurality of EL layers sandwiching a charge generation layer is described. A light emitting device having such a structure (hereinafter referred to as a tandem light emitting device) will be described.

[0104] The light-emitting element shown in this embodiment has a pair of electrodes (first electrode 30) as shown in FIG. A plurality of EL layers (first EL layer 302(1), second EL layer 302(2), and second EL layer 304) are disposed between the first and second electrodes. It is a tandem light emitting device having an L layer 302(2).

[0105] In this embodiment, the first electrode 301 is an electrode that functions as an anode, and the second electrode The electrode 304 functions as a cathode. 304 can have the same structure as that of the second embodiment. The first EL layer 302(1) and the second EL layer 302(2) are the same as the EL layers shown in the second embodiment. The first and second electrodes may have the same configuration, or either of them may have the same configuration. The EL layer 302(1) and the second EL layer 302(2) may have the same or different configurations. The same configuration as that of the second embodiment can be applied.

[0106] In addition, between the plurality of EL layers (the first EL layer 302(1) and the second EL layer 302(2)), The charge generation layer (I) 305 is provided on the first electrode. When a voltage is applied between the first electrode 301 and the second electrode 304, electrons are injected into one of the EL layers, and the other In this embodiment, the first electrode 301 has a function of injecting holes into the EL layer. When a voltage is applied so that the potential becomes higher than that of the second electrode 304, the charge generation layer (I) 30 Electrons are injected from the first EL layer 302(1) to the second EL layer 302(2). It is injected.

[0107] The charge generating layer (I) 305 is transparent to visible light from the viewpoint of light extraction efficiency. (specifically, the charge generating layer (I) 305 has a visible light transmittance of 40% or more) In addition, the charge generation layer (I) 305 is preferably formed of a material having a higher conductivity than the first electrode 301 and the second electrode 304. It works even with lower conductivity than

[0108] The charge generation layer (I) 305 is formed by adding an electron acceptor (acceptor) to an organic compound having high hole transport properties. ) is added, the electron donor (donor) is added to the organic compound with high electron transport properties. Alternatively, both of these structures may be laminated.

[0109] In the case where an electron acceptor is added to an organic compound having a high hole transporting property, Examples of organic compounds with high transportability include NPB, TPD, TDATA, and MTDATA. The substances mentioned here are mainly aromatic amine compounds such as BSPB. 10 to -6 cm 2 It is a material with a hole mobility of 1 / Vs or more. However, the number of holes is higher than that of electrons. Any organic compound having a high transportability may be used other than the above.

[0110] In addition, 7,7,8,8-tetracyano-2,3,5,6-tetramethyl ... Examples include fluoroquinodimethane (abbreviation: F4-TCNQ) and chloranil. Further examples include oxides of metals belonging to groups 4 to 8 of the periodic table. Specifically, vanadium oxide, niobium oxide, tantalum oxide, chromium oxide, and molybdenum oxide Tungsten oxide, manganese oxide, and rhenium oxide are preferred because of their high electron-accepting properties. However, molybdenum oxide is particularly preferred because it is stable in the air, has low hygroscopicity, and is easy to handle. It's nice.

[0111] On the other hand, in the case where an electron donor is added to an organic compound having high electron transport properties, Examples of organic compounds with high electron transport properties include Alq, Almq3, BeBq2, and B Metal complexes having a quinoline or benzoquinoline skeleton, such as Alq, can be used. In addition, oxazole-based compounds such as Zn(BOX)2 and Zn(BTZ)2, Metal complexes having azole-based ligands can also be used. However, PBD, OXD-7, TAZ, BPhen, BCP, etc. can also be used. The substances mentioned in are mainly 10-6 cm 2 It is a substance with an electron mobility of 1 / Vs or more. Any organic compound having a higher electron transporting property than holes may be used. stomach.

[0112] The electron donor may be an alkali metal, an alkaline earth metal, a rare earth metal, or or metals belonging to Groups 2 and 13 of the periodic table, and their oxides and carbonates. Specifically, lithium (Li), cesium (Cs), magnesium (Mg ), calcium (Ca), ytterbium (Yb), indium (In), lithium oxide It is preferable to use cesium carbonate or the like. The compound may be used as an electron donor.

[0113] In this embodiment mode, a light-emitting element having two EL layers has been described. As shown in the figure, n (n is 3 or more) EL layers (302(1) to 302(n)) are stacked. The same can be applied to a light emitting device in which a light emitting element is layered. When a plurality of EL layers are disposed between a pair of electrodes, as in the case of a device, the EL layers are By arranging the charge generation layers (I) (305(1) to 305(n-1)), the current density It is possible to emit light in a high brightness range while keeping the current density low. Furthermore, it is possible to realize a light emitting device, an electronic device, a lighting device, etc., which have a large light emitting surface. When applied to a large area, the voltage drop due to the resistance of the electrode material can be reduced, allowing for uniform Light emission becomes possible.

[0114] In addition, by making the luminescent color of each EL layer different, the desired luminescence color can be obtained as a whole. For example, in a light-emitting element having two EL layers, the first By making the luminous color of the first EL layer and the luminous color of the second EL layer complementary to each other, It is also possible to obtain a light-emitting element that emits white light as a whole. This refers to the relationship between colors that become achromatic when mixed together. This makes it possible to obtain white light emission.

[0115] The same applies to a light-emitting element having three EL layers. For example, The luminescent color of the first EL layer is red, the luminescent color of the second EL layer is green, and the luminescent color of the third EL layer is blue. In this case, the light emitting element as a whole can emit white light.

[0116] Note that the structure described in this embodiment mode may be used in appropriate combination with structures described in other embodiments. You can be there.

[0117] (Fourth embodiment) In this embodiment, a light-emitting device manufactured using a light-emitting element according to one embodiment of the present invention will be described. and explain.

[0118] The light emitting device may be a passive matrix light emitting device or an active matrix light emitting device. The light-emitting device shown in this embodiment may be the light-emitting device described in the other embodiments. A light emitting element can be applied.

[0119] In this embodiment mode, an active matrix light emitting device will be described with reference to FIG. .

[0120] 3A is a top view showing the light emitting device, and FIG. 3B is a top view showing the light emitting device as seen from the dashed line A- 1 is a cross-sectional view taken along line A' of the active matrix light emitting device according to the present embodiment. 5, a pixel section 502 provided on an element substrate 501, and a driving circuit section (source line driving circuit) 50 3 and a driving circuit section (gate line driving circuit) 504 (504a and 504b). The pixel portion 502, the driver circuit portion 503, and the driver circuit portion 504 are sealed by a sealant 505. It is sealed between the element substrate 501 and the sealing substrate 506 .

[0121] On the element substrate 501, a driving circuit section 503 and a driving circuit section 504 are provided. Signals (e.g., video signals, clock signals, start signals, reset signals, etc.) and potentials A wiring 507 is provided to connect an external input terminal that transmits the signal. An example of providing an FPC (flexible printed circuit) 508 as an external input terminal is shown. Although only the FPC is shown here, this FPC also has a printed wiring board. The light emitting device in this specification may be a light emitting device itself. This includes not only the body but also the state in which an FPC or PWB is attached to it.

[0122] Next, the cross-sectional structure will be described with reference to FIG. A driver circuit portion 503, which is a source line driver circuit, is formed in this example. 5, a pixel portion 502 is shown.

[0123] The driving circuit section 503 is a combination of an n-channel FET 509 and a p-channel FET 510. This shows an example in which a CMOS circuit is formed by combining the above. It may be formed of various CMOS circuits, PMOS circuits or NMOS circuits. The FET may be either a staggered type or an inverted staggered type. The crystallinity of the semiconductor is not particularly limited, and the semiconductor may be amorphous or crystalline. The materials used are IV group (silicon, gallium, etc.) semiconductors, compound semiconductors (oxide semiconductors, etc.) In addition to the above, organic semiconductors and the like can be used. This shows a driver integrated type with a driving circuit formed, but this is not necessarily required, and it is not on the board. A driving circuit can also be formed externally.

[0124] The pixel section 502 includes a switching FET 511, a current control FET 512, and a current A first line electrically connected to the wiring (source electrode or drain electrode) of the control FET 512 The first electrode (anode) 513 is formed of a plurality of pixels. An insulator 514 is formed covering the end of 13 .

[0125] In order to improve the covering property of the film formed on the upper layer, the upper end of the insulator 514 It is preferable that a curved surface having a curvature is formed at the upper or lower end. The material of the object 514 is either a negative photosensitive resin or a positive photosensitive resin. Not only organic compounds but also inorganic compounds such as silicon oxide and silicon oxynitride can be used. Both of these can be used.

[0126] An EL layer 515 and a second electrode (cathode) 516 are stacked on the first electrode (anode) 513. The EL layer 515 is provided with at least a light-emitting layer. In addition to the light-emitting layer, 15 includes a hole injection layer, a hole transport layer, an electron transport layer, an electron injection layer, and a charge generation layer. etc. can be provided as appropriate.

[0127] The total thickness of the first electrode (anode) 513, the EL layer 515 and the second electrode (cathode) 516 is The light-emitting element 517 is formed by the layer structure. The first electrode (anode) 513, the EL layer 515 The material used for the second electrode (cathode) 516 is the material shown in Embodiment 2. Although not shown here, the second electrode (cathode) 516 can be connected to an external input terminal The FPC 508 is electrically connected to the FPC 508.

[0128] In addition, although only one light-emitting element 517 is shown in the cross-sectional view of FIG. 3B, In the pixel section 502, a plurality of light emitting elements are arranged in a matrix. 02 is selectively formed with light-emitting elements that can emit three types of light (R, G, B), It is possible to form a light-emitting device capable of full-color display. By combining these, a light emitting device capable of full color display may be obtained.

[0129] Furthermore, by bonding a sealing substrate 506 to the element substrate 501 with a sealing material 505, The light is emitted into a space 518 surrounded by the element substrate 501, the sealing substrate 506, and the sealant 505. The structure is provided with an element 517. The space 518 is filled with an inert gas (nitrogen or In addition to the case where the cavity is filled with a gas such as argon, a configuration where the cavity is filled with a sealing material 505 is also included. .

[0130] It is preferable to use epoxy resin or glass frit for the sealing material 505. In addition, it is desirable that these materials be as impermeable to moisture and oxygen as possible. The sealing substrate 506 may be made of glass or quartz, or may be made of FRP (Fiber-Reinforced Plastic). Reinforced Plastics), PVF (Polyvinyl Fluoride), Polyethylene A plastic substrate made of a plastic resin such as steril or acrylic resin can be used. When glass frit is used as the adhesive, the element substrate 501 and the sealing substrate 502 are 506 is preferably a glass substrate.

[0131] In this manner, an active matrix light emitting device can be obtained.

[0132] Note that the structure described in this embodiment mode may be used in appropriate combination with structures described in other embodiments. You can be there.

[0133] (Embodiment 5) In this embodiment, a light-emitting device manufactured using a light-emitting element according to one embodiment of the present invention is used. Examples of various electronic devices completed using this method will be described with reference to FIGS. 4 and 5.

[0134] Examples of electronic devices to which light-emitting devices are applied include television sets (television sets, or television sets (also known as TV receivers), computer monitors, digital cameras, digital video digital cameras, digital photo frames, mobile phones (also called mobile phones or mobile phone devices), Examples include portable game machines, personal digital assistants, sound players, and large game machines such as pachinko machines. Specific examples of these electronic devices are shown in Figure 4.

[0135] FIG. 4A shows an example of a television device. The television device 7100 includes: A display unit 7103 is built into the housing 7101. The display unit 7103 displays images. The light-emitting device can be used in the display portion 7103. 7 shows a configuration in which a housing 7101 is supported by a stand 7105.

[0136] The television device 7100 can be operated using an operation switch provided on the housing 7101 or a separate remote control. This can be done by using the remote control operation device 7110. The channel and volume can be controlled by the -7109, and the information displayed on the display 7103 In addition, the remote control unit 7110 can be used to control the video. A display unit 7107 for displaying information output from the device 7110 may be provided.

[0137] The television device 7100 includes a receiver, a modem, and the like. It is possible to receive general television broadcasts by this, and furthermore, it is possible to receive television broadcasts by wired or wireless via a modem. By connecting to a communication network, it is possible to communicate in one direction (from sender to receiver) or two directions ( It is also possible to communicate information between a sender and a receiver, or between receivers.

[0138] FIG. 4B shows a computer, which includes a main body 7201, a housing 7202, a display unit 7203, and a keyboard. keyboard 7204, external connection port 7205, pointing device 7206, etc. Note that the computer can be manufactured by using a light-emitting device for the display portion 7203. This can be done.

[0139] FIG. 4C shows a smartwatch, which includes a housing 7302, a display panel 7304, and an operation button. Includes: Tan 7311, 7312, connecting terminal 7313, band 7321, clasp 7322, etc. do.

[0140] The display panel 7304 mounted on the housing 7302, which also serves as a bezel, is a non-rectangular display panel. The display panel 7304 has an icon 7305 that indicates the time, other icons, Con7306 etc. can be displayed.

[0141] The smartwatch shown in FIG. 4(C) can have various functions. For example, functions to display various information (still images, videos, text images, etc.) on the display, Panel function, calendar, date or time display function, various software (programs) It has the functions of controlling processing by RAM, wireless communication functions, and various computers using wireless communication functions. Functions for connecting to computer networks, sending or receiving various data using wireless communication functions The function of reading out the program or data recorded on the recording medium and displaying it on the display unit. It may have the function of:

[0142] In addition, a speaker, a sensor (force, displacement, position, velocity, acceleration, angle) Speed, rotation speed, distance, light, liquid, magnetism, temperature, chemical substances, sound, time, hardness, electric field, current, Includes functions to measure voltage, power, radiation, flow rate, humidity, gradient, vibration, odor, or infrared rays The smartwatch may have a light-emitting device, a microphone, etc. The display panel 7304 can be manufactured by using the above.

[0143] FIG. 4D shows an example of a mobile phone. The mobile phone 7400 has a housing 7401. In addition to the display unit 7402 incorporated in the The mobile phone 7400 is equipped with a speaker 7405, a microphone 7406, and the like. The device is used in the display portion 7402 .

[0144] A mobile phone 7400 shown in FIG. 4D displays information by touching the display portion 7402 with a finger or the like. You can also make calls, write emails, and perform other operations. This can be done by touching the display portion 7402 with a finger or the like.

[0145] The screen of the display unit 7402 has three main modes. The first is a mode that mainly displays images. The first mode is a display mode, and the second mode is an input mode that mainly inputs information such as characters. This is a display + input mode that combines the display mode and the input mode.

[0146] For example, when making a call or creating an email, the display portion 7402 is used for inputting characters. In this case, you can input 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. Desirable.

[0147] In addition, detectors such as a gyro sensor and an acceleration sensor are provided inside the mobile phone 7400. By doing so, the orientation of the mobile phone 7400 (portrait or landscape) is determined, and the screen display of the display unit 7402 is can be set to switch automatically.

[0148] The screen mode can be switched by touching the display portion 7402 or operating the housing 7401. The type of image displayed on the display unit 7402 can be selected by operating the create button 7403. For example, the image signal to be displayed on the display unit can be switched by If the data is text data, the mode switches to display mode, and if the data is text data, the mode switches to input mode.

[0149] In the input mode, the display unit 7402 detects a signal from an optical sensor. If it is determined that there is no input by touch operation on the display unit 7402 for a certain period of time, the screen mode The mode may be controlled to switch from input mode to display mode.

[0150] The display portion 7402 can also function as an image sensor. By touching 402 with the palm or fingers and capturing an image of the palm print, fingerprint, etc., personal authentication can be performed. In addition, if a sensing light source that emits near-infrared light is used in the display, finger veins, palm veins, etc. can be detected. You can also take pictures.

[0151] Figures 5(A) and 5(B) show a foldable tablet terminal. Figure 5(A) shows In the open state, the tablet terminal includes a housing 9630, a display unit 9631a, a display unit 96 31b, display mode changeover switch 9034, power switch 9035, power saving mode changeover switch The switch 9036, the fastener 9033, and the operation switch 9038 are included. The tablet terminal has a light emitting device in one or both of the display portions 9631a and 9631b. It is produced by using

[0152] A part of the display portion 9631a can be used as a touch panel area 9632a. By touching the operation keys 9637, data can be input. In 31a, for example, half of the area has a display function only, and the other half Although the display area 96 has a touch panel function, the display area 96 is not limited to this configuration. The entire area of ​​the display unit 9 may have a touch panel function. The entire surface of 631a is used as a touch panel by displaying keyboard buttons, and the display part 9631b is used as a touch panel. It can be used as a display screen.

[0153] In addition, in the display unit 9631b, as in the display unit 9631a, The area can be used as a touch panel area 9632b. Touch the area where the display switch button 9639 is displayed with your finger or a stylus. This allows keyboard buttons to be displayed on the display portion 9631b.

[0154] In addition, the touch panel area 9632a and the touch panel area 9632b are simultaneously You can also use touch input.

[0155] A display mode changeover switch 9034 is used to change the display orientation, such as portrait or landscape. You can switch between black and white and color display. The switch 9036 detects the external light intensity during use as measured by the light sensor built into the tablet device. The display brightness can be optimized according to the amount of light. In addition to the sensor, a detector such as a gyro sensor or an acceleration sensor may be built in.

[0156] FIG. 5A shows an example in which the display area of ​​the display portion 9631b is the same as that of the display portion 9631a. However, there is no particular limitation, and one size may be different from the other, and the display For example, one display panel may be capable of displaying images with higher resolution than the other. It may also be possible to use the following.

[0157] FIG. 5B shows the tablet terminal in a closed state. The tablet terminal includes a housing 9630 and a solar cell 96 33, a charge / discharge control circuit 9634, a battery 9635, and a DC / DC converter 9636 do.

[0158] In addition, since the tablet device can be folded in half, when not in use, the case 9630 is closed. Therefore, the display portions 9631a and 9631b can be protected. This makes it possible to provide a tablet device that is highly durable and reliable even for long-term use.

[0159] In addition, the tablet devices shown in Fig. 5(A) and Fig. 5(B) also have a calendar Various information such as date or time can be displayed on the display as a still image, video, or text image. A function to display information, a touch input function to operate or edit the information displayed on the display unit, It can have the function of controlling processing by various software (programs), etc. .

[0160] The solar cell 9633 attached to the surface of the tablet terminal supplies power to the touch panel. The solar cell 9633 can be supplied to a display unit, a video signal processor, or the like. , which can be provided on one or both sides of the housing 9630, and can efficiently charge the battery 9635. The battery 9635 can be a lithium-ion battery. The use of a pond has the advantage of being able to make the facility smaller.

[0161] The configuration and operation of the charge / discharge control circuit 9634 shown in FIG. 5B are shown in FIG. A block diagram is shown in Figure 5(C) and will be explained. , DC-DC converter 9636, converter 9638, switches SW1 to SW3, display The figure shows the part 9631, the battery 9635, the DC-DC converter 9636, The inverter 9638 and the switches SW1 to SW3 are connected to the charge / discharge control circuit 96 shown in FIG. This corresponds to 34.

[0162] An example of operation when external light is received and power is generated by the solar cell 9633 will be described. The power generated by the solar cell 9633 is converted into a voltage for charging the battery 9635. The voltage is increased or decreased by the DC-DC converter 9636. When power is used from the solar cell 9633 for operation, switch SW1 is turned on and the converter The voltage is increased or decreased by a voltage controller 9638 to the voltage required for the display unit 9631. When not displaying on the display unit 9631, the switch SW1 is turned off and the switch SW2 is turned on. The configuration may be such that the power supply is turned on to charge the battery 9635.

[0163] The solar cell 9633 is shown as an example of a power generating means, but is not particularly limited thereto. Other power generation methods such as piezoelectric elements and thermoelectric conversion elements (Peltier elements) For example, the battery 9635 may be charged wirelessly (contactlessly). A wireless power transmission module that receives and charges, or a structure that combines other charging methods It may also be composed.

[0164] Furthermore, if the display unit described in this embodiment is provided, the electronic device shown in FIG. It goes without saying that there is no limitation.

[0165] As described above, an electronic device can be obtained by applying the light-emitting device which is one embodiment of the present invention. The range of applications for light-emitting devices is extremely wide, and they can be used in electronic devices in a wide range of fields. is.

[0166] Note that the structure described in this embodiment mode may be used in appropriate combination with structures described in other embodiments. You can be there.

[0167] (Embodiment 6) In this embodiment, a lighting device using a light-emitting device including a light-emitting element according to one embodiment of the present invention is described. An example of this will be described with reference to FIG.

[0168] FIG. 6 shows an example in which the light emitting device is used as an indoor lighting device 8001. It is also possible to make it larger, so it is possible to form a large-area lighting device. By using a housing having such a curved surface, it is possible to form a lighting device 8002 having a light-emitting region with a curved surface. The light-emitting element included in the light-emitting device shown in this embodiment mode has a thin film shape, and the design of the housing Therefore, lighting devices with various elaborate designs can be created. Furthermore, a large lighting device 8003 may be provided on the wall of the room.

[0169] In addition, by using a light emitting device on the surface of a table, it is possible to make a lighting device that functions as a table. The lighting device 8004 can be used as a lighting device. This allows the lighting device to function as furniture.

[0170] As described above, various lighting devices using the light-emitting device can be obtained. This device is included in one aspect of the present invention.

[0171] The structure described in this embodiment mode may be used in appropriate combination with structures described in other embodiments. You can be there. [Example]

[0172] <Synthesis Example 1> In this example, an organic compound represented by the structural formula (100) in Embodiment 1, which is one embodiment of the present invention, Compound, N-(4-biphenyl)-N-(9,9-dimethyl-9H-fluoren-2-yl The synthesis method of dibenzofuran-4-amine (abbreviation: FrBiF) will be described. Incidentally, the structure of FrBiF is shown below.

[0173]

Chemical formula

[0174] <Synthesis of FrBiF> In a 200 mL three-necked flask, 2.3 g (6.4 mmol) of N-(4-biphenyl)-9,9-dimethyl-9H-fluoren-2-amine, 1.9 g (6.4 mmol) of 4-iododibenzofuran, and 1.9 g (19 mmol) of sodium tert-butoxide were added. 35 mL of toluene and 0.2 mL of a 10% hexane solution of tri(tert-butyl)phosphine were added to this mixture, and the mixture was degassed by stirring under reduced pressure . .

[0175] 37 mg (0.0.06 4 mmol) of bis(dibenzylideneacetone)palladium(0) was added to this mixture, and the mixture was heated and stirred at 110 °C for 8.5 hours under a nitrogen stream. After stirring, toluene was added to this mixture, and the resulting mixture was suction filtered through Florisil, Celite, and alumina to obtain a filtrate. The obtained filtrate was washed with water and saturated brine, and the organic layer was dried with magnesium sulfate . This mixture was filtered off by natural filtration, and the filtrate was concentrated to obtain a solid . This solid was purified by silica gel column chromatography. The column chromatography was carried out using toluene:hexane = 1:2 as the developing solvent. The obtained fractions were concentrated to obtain a solid. The obtained solid was recrystallized from hexane to obtain 2.6 g of the target white solid g, with a yield of 76%.

[0176] The obtained white solid was purified by train sublimation. The white solid was heated to 210°C under conditions of a pressure of 3.1 Pa and an argon flow rate of 5 mL / min. After sublimation purification, 1.1 g of a pale yellow solid was obtained with a recovery rate of 52%. The synthesis scheme is shown in (A-1) below.

[0177] [ka]

[0178] The pale yellow solid obtained by the above synthesis method was analyzed by nuclear magnetic resonance spectroscopy ( 1 H-NMR The analysis results are shown below. 1 The H-NMR chart is shown in Figure 7. 1 H-NM From the R chart, in this Synthesis Example 1, one embodiment of the present invention represented by the above structural formula (100) was It was found that the organic compound FrBiF similar to the above was obtained.

[0179] 1 H-NMR(DMSO-d6,500MHz):δ=1.34(s,6H),7.0 4-7.07(m,3H),7.25-7.33(m,5H),7.39-7.52(m ,7H),7.62(d,J1=8.5Hz,2H),7.65(d,J1=7.5Hz ,2H),7.75(t,J1=7.5Hz,2H),8.03(dd,J1=7.5H z,J2=1.5Hz,1H),7.71(d,J1=7.0Hz,1H).

[0180] Next, the UV-visible absorption spectra (hereafter simply referred to as "absorption spectra") of the solution and thin film of FrBiF were measured. The absorption spectrum was measured using ultraviolet-visible A spectrophotometer (Nihon Bunko Co., Ltd., V550 model) was used, and the solution was a toluene solution of FrBiF. The solution was placed in a quartz cell and measured at room temperature. The thin film was prepared by depositing FrBiF on a quartz substrate. The emission spectra were measured at room temperature using the same equipment. Using a meter (FS920 manufactured by Hamamatsu Photonics Inc.), the toluene solution was placed in a quartz cell and the The thin film was prepared by depositing FrBiF on a quartz substrate in the same apparatus. The measurements were carried out at room temperature.

[0181] The absorption spectrum and emission spectrum of the solution are shown in Figure 8(A). The spectra and emission spectra are shown in Figure 8(B). The axis represents the wavelength, and the vertical axis represents the absorption intensity and the emission intensity. Two solid lines are shown for each sample. The thin solid line indicates the absorption spectrum, and the thick solid line indicates the absorption spectrum. The lines indicate the emission spectrum. The absorption spectra shown in Figures 8(A) and 8(B) are In the case of a liquid, the absorption spectrum of toluene is subtracted from the absorption spectrum obtained. In the case of a thin film, the absorption spectrum of the quartz substrate can be calculated from the obtained absorption spectrum. was obtained by subtracting

[0182] As shown in Figure 8(A) and (B), FrBiF exhibited 286 and 349 The thin film had an absorption peak at 401 nm and an emission peak at 401 nm. It has absorption peaks at 259, 291, and 356 nm and an emission peak at 413 nm. was.

[0183] Next, the FrBiF obtained in this example was analyzed by liquid chromatography mass spectrometry (LCMS). Chromatography Mass Spectrometry (LC / Mass spectrometry (MS) was performed.

[0184] LC / MS was performed using a Waters Acquit (liquid chromatography) system. Mass spectrometry (MS) was performed using a Waters Xevo G2 Tof The LC separation was performed using an Acquity UPLC BEH C column. 8 (2.1 × 100 mm 1.7 μm), the column temperature was 40 °C. The mobile phase was A was acetonitrile, and B was a 0.1% formic acid aqueous solution. FrBiF was dissolved in toluene and diluted with acetonitrile. The injection volume was 5.0 mL. In μL.

[0185] For MS analysis, electrospray ionization was used. The capillary voltage was set to 0.2 V. ... The voltage was 3.0 kV, the sample cone voltage was 30 V, and detection was performed in positive mode. All ionized components are collided with argon gas in a collision cell under the conditions The energy of the collision with argon (collision The electron energy was set to 6 eV and 30 eV. The mass range measured was m / z = 100 Figure 9 shows the product ions generated by time-of-flight (TOF) MS. Figure 9(A) shows the measurement results when the collision energy is 6 eV. 9(B) shows the measurement results when the collision energy is 30 eV.

[0186] From the results of Figure 9(A), when the collision energy is 6 eV, FrBiF Due to the presence or absence of ions and the presence of isotopes, multiple ions were detected mainly around m / z = 528. The results shown in Figure 9(A) are considered to be important data for identifying FrBiF. can.

[0187] In addition, from the results of Figure 9(B), when the collision energy is 30 eV, Ions that were not detected when the collision energy was 6 eV were detected. When the energy is 30 eV, FrBiF is mainly due to the presence or absence of hydrogen ions and the presence of isotopes. The precursor ions are located around m / z=528, around m / z=375, around m / z=361, and around m It was found that multiple product ions were detected around z=334. From the results shown in Figure 9(A)(B), the peaks around m / z=375, m / z=361, and m / z The multiple product ions detected around =334 are products derived from FrBiF. This indicates that FrBiF is an ion, which is important data for identifying FrBiF in a mixture. It can be said that this is the case.

[0188] The product ion at m / z=375 is due to the biphenyl group in FrBiF. It is assumed that the cation is in the detached state, indicating that FrBiF contains a biphenyl group. It is a suggestion.

[0189] The product ion around m / z=361 is the dibenzofuranyl group in FrBiF. It is assumed that the cation is in the isolated state, and FrBiF contains a dibenzofuranyl group. This suggests that:

[0190] The product ion at m / z=334 is dimethylfluorenyl in FrBiF. It is assumed that the cation is in a state where the group has been removed, and FrBiF contains a dimethylfluorenyl group. This suggests that [Example]

[0191] In this example, an organic compound, N-(4-biphenyl)-N-(9 ,9-dimethyl-9H-fluoren-2-yl)dibenzofuran-4-amine (abbreviation: F The light-emitting element 1 using rBiF (structural formula (100)) in the light-emitting layer will be described with reference to FIG. 10. The chemical formulas of the materials used in this example are shown below.

[0192] [ka]

[0193] <Fabrication of Light-Emitting Device 1> First, indium tin oxide containing silicon oxide (ITSO) was deposited on a glass substrate 1100. A film was formed by sputtering to form a first electrode 1101 that functions as an anode. The film thickness was 110 nm and the electrode area was 2 mm x 2 mm.

[0194] Next, as a pretreatment for forming the light emitting element 1 on the substrate 1100, the surface of the substrate is washed with water. After cleaning and baking at 200°C for 1 hour, UV ozone treatment was performed for 370 seconds.

[0195] Then, 10 -4 The substrate is placed in a vacuum deposition apparatus whose inside pressure has been reduced to about 100 Pa. After vacuum baking at 170° C. for 30 minutes in the heating chamber of the deposition apparatus, the substrate 1100 It was left to cool for about 30 minutes.

[0196] Next, the substrate 1100 is vacuum-steamed so that the surface on which the first electrode 1101 is formed faces downward. In this example, the EL layer 1 was formed by vacuum deposition. 102 comprises a hole injection layer 1111, a hole transport layer 1112, a light emitting layer 1113, and an electron transport layer The case where the layer 1114 and the electron injection layer 1115 are formed in this order will be described.

[0197] The vacuum deposition equipment was -4 After reducing the pressure to 100 Pa, 1,3,5-tri(dibenzothiophene -4-yl)benzene (abbreviation: DBT3P-II) and molybdenum(VI) oxide were reacted with DB By co-evaporating T3P-II and molybdenum oxide at a mass ratio of 4:2, A hole injection layer 1111 was formed on the first electrode 1101. The thickness of the layer was 20 nm. Co-evaporation is a deposition method in which different substances are evaporated simultaneously from different evaporation sources. do.

[0198] Next, 4-phenyl-4'-(9-phenylfluoren-9-yl)triphenylamine A hole transport layer 1112 is formed by depositing 20 nm of BPAFLP. Ta.

[0199] Next, the light-emitting layer 1113 was formed on the hole-transporting layer 1112. [4-(4-phenyl-4-yl)biphenyl-3-yl]dibenzo[f,h]quinoxaline (abbreviated as 2mDBTBPDBq-II), FrBiF, (acetylacetonato)bis(6-tert-butyl ether) t-Butyl-4-phenylpyrimidinato)iridium(III) (abbreviation: [Ir(tBu ppm)2(acac)]), 2mDBTBPDBq-II:FrBiF:[Ir(t Buppm)2(acac)] = 0.7:0.3:0.05 (mass ratio) After co-evaporation with a thickness of nm, 2mDBTBPDBq-II:FrBiF:[Ir( tBuppm)2(acac)] = 0.8:0.2:0.05 (mass ratio) The film was co-evaporated to a thickness of 0 nm.

[0200] Next, 2mDBTBPDBq-II was deposited to 10 nm on the light-emitting layer 1113, and then By depositing phenanthroline (abbreviation: Bphen) to a thickness of 15 nm, an electron transport layer 111 Furthermore, lithium fluoride was deposited on the electron transport layer 1114 to a thickness of 1 nm. Thus, an electron injection layer 1115 was formed.

[0201] Finally, aluminum was evaporated onto the electron injection layer 1115 to a thickness of 200 nm. Then, a second electrode 1103 serving as a cathode was formed, and the light-emitting element 1 was obtained. In all cases, the deposition was carried out using a resistance heating method.

[0202] The element structure of the light-emitting element 1 obtained as described above is shown in Table 1.

[0203] [Table 1]

[0204] The fabricated light-emitting element 1 was placed in a glove box with a nitrogen atmosphere to prevent exposure to the atmosphere. (Sealing material was applied around the element, and heat treatment was performed at 80°C for 1 hour during sealing.) ).

[0205] <Operating characteristics of light-emitting element 1> The operating characteristics of the fabricated light-emitting element 1 were measured. The measurements were carried out at room temperature (25°C). The atmosphere was very friendly.

[0206] First, current density-luminance characteristics of the light-emitting element 1 are shown in FIG. is the luminance (cd / m 2 ), and the horizontal axis is the current density (mA / cm 2 ) is shown. The voltage-luminance characteristics are shown in Figure 12. In Figure 12, the vertical axis represents luminance (cd / m 2 ), The horizontal axis represents voltage (V). The luminance vs. current efficiency characteristics of the light-emitting element 1 are shown in FIG. In FIG. 13, the vertical axis represents current efficiency (cd / A) and the horizontal axis represents luminance (cd / m 2 ) FIG. 14 shows the voltage-current characteristics of the light-emitting element 1. In FIG. 14, the vertical axis represents ,current (mA), and the horizontal axis indicates voltage (V).

[0207] FIG. 13 shows that the light-emitting element 1 of one embodiment of the present invention is a highly efficient element. Also, 800cd / m 2 The main initial characteristic values ​​of the light-emitting element 1 in the vicinity are shown in Table 2 below. .

[0208] [Table 2]

[0209] The above results show that the light-emitting element 1 fabricated in this example exhibits good current efficiency. Furthermore, it is clear that yellow-green light emission with good color purity is exhibited.

[0210] Also, 25mA / cm 2 The emission spectrum of the light-emitting element 1 at a current density of 1000 .mu.m is shown in FIG. As shown in Figure 15, the emission spectrum of Light-Emitting Device 1 has a peak at 550 nm. It was shown that this is due to the emission of the organometallic complex [Ir(tBuppm)2(acac)]. To be tempted.

[0211] A reliability test was also conducted on the light-emitting element 1. The results of the reliability test are shown in FIG. In FIG. 16, the vertical axis indicates normalized brightness (%) when the initial brightness is 100%, and the horizontal axis indicates The reliability test was conducted at an initial brightness of 5000 cd / m 2 Set in The light-emitting element 1 was driven under the condition of a constant current density. After a short time, the brightness remained at approximately 87% of the initial brightness.

[0212] Therefore, it was found that the light-emitting element 1 had high reliability. By using organic compounds with high efficiency in light-emitting elements, it is possible to achieve light-emitting elements with long life. It was found that it can be obtained. [Example]

[0213] In this example, 2mDBTBP was used as one of the two organic compounds that form exciplexes. DBq-II was used, and on the other hand, the organic compound FrBiF (HOMO=- 5.48(eV)) to form a mixed film (A), and the emission spectrum of this mixed film (A) The emission spectrum was measured using a fluorometer (Hamamatsu Photonics Co., Ltd.). Mixed film (A) and mixed film (B) were formed by vapor deposition on a quartz substrate using a quartz crystal sintered glass (FS920). The measurements were carried out at room temperature using the above-mentioned apparatus.

[0214] The mixed film (A) is 10 -4 In a vacuum deposition apparatus at a reduced pressure of 20 Pa, 2 mDB was deposited on a quartz substrate. A 50 nm film was prepared so that the mass ratio of TBPDBq-II:FrBiF was 0.8:0.2. It was formed by co-evaporation in a thick layer.

[0215] As a comparative example, instead of FrBiF, an organic compound having a higher HOMO level than FrBiF was used. The compound N-(1,1'-biphenyl-4-yl)-9,9-dimethyl-N-[4-(9- Phenyl-9H-carbazol-3-yl)phenyl]-9H-fluoren-2-amine (Abbreviation: PCBBiF, HOMO=-5.36(eV) was used, and the same method as the mixed film (A) was used. A mixed film (B) was formed by the method, and its emission spectrum was measured.

[0216] The measurement results are shown in Figure 17(A). Figure 17(B) shows the results for FrBiF and PCBBiF. The emission spectra of the single films of 2mDBTBPDBq-II and 2mDBTBPDBq-II are shown in Figure 17(A). In this study, luminescence was observed in the single films of FrBiF, PCBBiF, and 2mDBTBPDBq-II. No visible light was observed, and a broad emission was obtained in the long wavelength region. It can be seen that the emission spectrum of the mixed film (A) is different from that of the mixed film (B). ) emission spectrum, which is shorter in wavelength than that of the material that emits light at a shorter wavelength. It can be said to be advantageous.

[0217] Therefore, by using the organic compound of one embodiment of the present invention in the light-emitting layer of the light-emitting element, an exciplex This allows the formation of exciplexes that emit short wavelengths (e.g., from around 450 nm to 5 50 nm) can emit light. This is effective in increasing the luminous efficiency. [Example]

[0218] <Synthesis Example 2> In this example, an organic compound represented by structural formula (103) in Embodiment 1, which is one embodiment of the present invention, Compound, N-(4-biphenyl)-N-(9,9-dimethyl-9H-fluorene-2-yl dibenzofuran-2-amine (abbreviation: FrBiF-02) will be described. The structure of FrBiF-02 is shown below.

[0219]

Chemical formula

[0220] <Synthesis of FrBiF-02> In a 200 mL three-necked flask, 2.1 g (5.7 mmol) of N-(4-biphenyl)-9,9-dimethyl-9H-fluorene-2-amine, 1.4 g (5.7 mmol) of 2-bromodibenzofuran, and 1.6 g (17 mmol) of sodium tert-butoxide were added. To this mixture, 30 mL of toluene and 0.2 mL of a 10% hexane solution of tris(tert-butyl)phosphine were added, and the mixture was degassed by stirring under reduced pressure . 33 mg (0.0 57 mmol) of bis(dibenzylideneacetone)palladium(0) was added to this mixture, and it was heated and stirred at 110 °C for 19.5 hours under a nitrogen stream.

[0221] <00017二十一>After stirring, toluene was added to this mixture, and the resulting mixture was suction filtered through Florisil, Celite, and alumina to obtain a filtrate. The obtained filtrate was washed with water and saturated brine, and the organic layer was dried over magnesium sulfate. This mixture was filtered off by gravity filtration, and the filtrate was concentrated

[0222] to obtain an oily substance.

[0222] This oily substance was purified by silica gel column chromatography. The column chromatography was carried out using toluene:hexane = 1:2 as the developing solvent. The obtained fractions The solvent was concentrated to give 1.5 g of a white solid, which was the target product, in a yield of 49%.

[0223] The resulting white solid (1.3 g) was purified by train sublimation. The preparation was carried out by heating a white solid at 220°C under conditions of a pressure of 2.8 Pa and an argon flow rate of 5 mL / min. After purification by sublimation, 1.1 g of a pale yellow solid was obtained with a recovery rate of 90%. The synthesis scheme of the method is shown below in (B-1).

[0224] [ka]

[0225] The pale yellow solid obtained by the above synthesis method was analyzed by nuclear magnetic resonance spectroscopy ( 1 H-NMR The analysis results are shown below. 1 The H-NMR chart is shown in Figure 18. 1 HN From the MR chart, it can be seen that in Synthesis Example 2, one of the compounds of the present invention represented by the above structural formula (103) was obtained. It was found that the organic compound FrBiF-02 was obtained.

[0226] 1 H-NMR(DMSO-d6,500MHz):δ=1.37(s,6H),7.0 4(dd,J1=8.0Hz,J2=2.0Hz,1H),7.10(d,J1=8.5 Hz,2H),7.26(t,J1=7.5Hz,1H),7.27-7.37(m,5 H),7.43(d,J1=7.5Hz,2H),7.49-7.54(m,2H),7 .61(d,J1=8.5Hz,2H),7.64(d,J1=8.0Hz,2H),7 .70-7.76(m,4H),8.03(d,J1=1.5Hz,1H),8.13( d, J1 = 7.5 Hz, 1 H).

[0227] Next, the absorption and emission spectra of the solution and thin film of FrBiF-02 were measured. The absorption spectrum was measured using an ultraviolet-visible spectrophotometer (V550 model, manufactured by JASCO Corporation). ) was used, and the solution was a toluene solution of FrBiF-02 placed in a quartz cell and measured at room temperature. In addition, the thin film was prepared by depositing FrBiF-02 on a quartz substrate using the same equipment at room temperature. The emission spectrum was measured using a fluorometer (Hamamatsu Photonics Co., Ltd.). Using a FS920, the toluene solution was placed in a quartz cell and measurements were taken at room temperature. was measured at room temperature using a similar device on a quartz substrate coated with FrBiF-02.

[0228] The absorption spectrum and emission spectrum of the solution are shown in Figure 19(A). The spectrum and emission spectrum are shown in Figure 19(B). In both cases, the horizontal axis represents wavelength and the vertical axis represents absorption intensity and emission intensity. Two solid lines are shown for each of the spectra, and the thin solid lines represent the absorption spectrum. The thick solid line indicates the emission spectrum. In the case of a solution, the absorption spectrum of toluene is subtracted from the absorption spectrum obtained. In the case of a thin film, the absorption spectrum obtained is subtracted from the absorption of the quartz substrate. The absorption spectrum from which the spectrum was subtracted is shown.

[0229] The results shown in FIGS. 19A and 19B indicate that the organic compound FrBiF-0 2 has absorption peaks at 279, 302, 331, and 354 nm in solution, and 4 It can be seen that the emission peak is at 11 nm (excitation wavelength 362 nm). has absorption peaks at 278, 292, 303, 333 and 353 nm, and The emission peak was at 375 nm (excitation wavelength).

[0230] Next, FrBiF-02 obtained in this example was subjected to MS analysis by LC / MS.

[0231] LC / MS was performed using a Waters Acquit (liquid chromatography) system. Mass spectrometry (MS) was performed using a Waters Xevo G2 Tof The LC separation was performed using an Acquity UPLC BEH C column. 8 (2.1 × 100 mm 1.7 μm), the column temperature was 40 °C. The mobile phase was A was acetonitrile, and B was a 0.1% formic acid aqueous solution. The amount of FrBiF-02 was dissolved in toluene and diluted with acetonitrile. The volume was 5.0 μL.

[0232] For MS analysis, electrospray ionization was used. ionization (abbreviated as ESI) and then detected by a time-of-flight (TOF) detector. The capillary voltage during ionization was 3.0 kV, and the sample was The voltage was set to 30 V, and detection was performed in positive mode. The component at z=527 is collided with argon gas in a collision cell to produce a product. The energy required to collide with argon (collision energy) The energy was set to 6 eV and 30 eV. The mass range for measurement was m / z = 100 to 1120. The results of the LC / MS analysis are shown in Figure 20. Figure 20(A) shows the results of the LC / MS analysis when the collision energy was 6 Figure 20(B) shows the measurement results when the collision energy is 30 eV. Show the results.

[0233] From the results of Figure 20(A), when the collision energy is 6 eV, FrBiF-02 , due to the presence or absence of hydrogen ions and the presence of isotopes, several molecules are mainly observed around m / z=527. The results shown in Figure 20(A) are important for identifying FrBiF-02. This can be said to be important data.

[0234] From the results of Figure 20(B), when the collision energy is 30 eV, Ions that were not detected when the collision energy was 6 eV were detected. At 30 eV, FrBiF-02 is mainly due to the presence or absence of hydrogen ions and the presence of isotopes. The precursor ions are located around m / z=527, around m / z=512, around m / z=375, Multiple product ions were detected around m / z=361 and m / z=335. From the results shown in Figure 20(A)(B), it was found that the peaks near m / z=512 and m Multiple products were detected around m / z=375, m / z=361, and m / z=335. The product ions were derived from FrBiF-02, and the mixture This is important data for identifying the FrBiF-02 contained within.

[0235] The product ion around m / z=512 is due to the methyl group being released from FrBiF-02. This suggests that FrBiF-02 contains a methyl group. This is what we do.

[0236] The product ion around m / z=375 is due to the biphenyl group in FrBiF-02. It is assumed that the cation is in a detached state, and FrBiF-02 contains a biphenyl group. This suggests that:

[0237] The product ion around m / z=361 is a dibenzofuranone in FrBiF-02. It is assumed that FrBiF-02 is a cation with the dibenzofuranyl group removed. This suggests that it contains

[0238] The product ion around m / z=335 is a dimethyl fluoride in FrBiF-02. It is assumed that FrBiF-02 is a cation in which the phenyl group has been removed, and This suggests that it contains a methyl group. [Example]

[0239] In this example, the organic compound N-(4-biphenyl)-N-(9, 9-Dimethyl-9H-fluoren-2-yl)dibenzofuran-2-amine (abbreviation: Fr Regarding light-emitting element 2, BiF-02 (structural formula (103)) was used in the hole transport layer and the light-emitting layer. This will be explained with reference to Fig. 10. The chemical formulas of the materials used in this example are shown below.

[0240] [ka]

[0241] <Fabrication of light-emitting element 2> First, indium tin oxide containing silicon oxide (ITSO) was deposited on a glass substrate 1100. A film was formed by sputtering to form a first electrode 1101 that functions as an anode. The film thickness was 110 nm and the electrode area was 2 mm x 2 mm.

[0242] Next, as a pretreatment for forming the light emitting element 2 on the substrate 1100, the surface of the substrate is washed with water. After cleaning and baking at 200°C for 1 hour, UV ozone treatment was performed for 370 seconds.

[0243] Then, 10 -4 The substrate is placed in a vacuum deposition apparatus whose inside pressure has been reduced to about 100 Pa. After vacuum baking at 170° C. for 30 minutes in the heating chamber of the deposition apparatus, the substrate 1100 It was left to cool for about 30 minutes.

[0244] Next, the substrate 1100 is vacuum-steamed so that the surface on which the first electrode 1101 is formed faces downward. In this example, the EL layer 1 was formed by vacuum deposition. 102 comprises a hole injection layer 1111, a hole transport layer 1112, a light emitting layer 1113, and an electron transport layer The case where the layer 1114 and the electron injection layer 1115 are formed in this order will be described.

[0245] The vacuum deposition equipment was -4 After reducing the pressure to 100 Pa, 1,3,5-tri(dibenzothiophene -4-yl)benzene (abbreviation: DBT3P-II) and molybdenum(VI) oxide were reacted with DB By co-evaporating T3P-II and molybdenum oxide at a mass ratio of 4:2, A hole injection layer 1111 was formed on the first electrode 1101. The film thickness was set to 20 nm.

[0246] Next, a hole transport layer 1112 is formed by depositing FrBiF-02 at 20 nm. Ta.

[0247] Next, the light-emitting layer 1113 was formed on the hole-transporting layer 1112. [4-(4-phenyl-4-yl)biphenyl-3-yl]dibenzo[f,h]quinoxaline (abbreviated as 2mDBTBPDBq-II), FrBiF-02, (acetylacetonato)bis(6- tert-Butyl-4-phenylpyrimidinato)iridium(III) (abbreviation: [Ir( tBuppm)2(acac)]) and 2mDBTBPDBq-II:FrBiF-02 :[Ir(tBuppm)2(acac)]=0.7:0.3:0.05 (mass ratio) After co-evaporation with a thickness of 20 nm, 2mDBTBPDBq-II:FrBi F-02:[Ir(tBuppm)2(acac)]=0.8:0.2:0.05(mass The film was co-deposited to a thickness of 20 nm so that the ratio of the two layers was 100%.

[0248] Next, 2mDBTBPDBq-II was deposited to 20 nm on the light-emitting layer 1113, and then By depositing phenanthroline (abbreviation: Bphen) to 10 nm, an electron transport layer 111 Furthermore, lithium fluoride was deposited on the electron transport layer 1114 to a thickness of 1 nm. Thus, an electron injection layer 1115 was formed.

[0249] Finally, aluminum was evaporated onto the electron injection layer 1115 to a thickness of 200 nm. Then, a second electrode 1103 serving as a cathode was formed, and a light-emitting element 2 was obtained. In all cases, the deposition was carried out using a resistance heating method.

[0250] The element structure of the light-emitting element 2 obtained as described above is shown in Table 3.

[0251] [Table 3]

[0252] The fabricated light-emitting element 2 was placed in a glove box with a nitrogen atmosphere to prevent exposure to the atmosphere. (Sealing material was applied around the element, and heat treatment was performed at 80°C for 1 hour during sealing.) ).

[0253] <Operating characteristics of light-emitting element 2> The operating characteristics of the fabricated light-emitting element 2 were measured. The measurements were carried out at room temperature (25°C). The atmosphere was very friendly.

[0254] First, the voltage-luminance characteristics of the light-emitting element 2 are shown in FIG. 21. In FIG. 21, the vertical axis represents Luminance (cd / m 2 The horizontal axis represents voltage (V), and the luminance-current efficiency characteristics of the light-emitting element 2 are shown in FIG. The efficiency is shown in Figure 22. In Figure 22, the vertical axis represents the current efficiency (cd / A) and the horizontal axis represents the luminance. degree (cd / m 2 ) is shown. Also, the voltage-current characteristics of the light-emitting element 2 are shown in FIG. 23, the vertical axis indicates current (mA) and the horizontal axis indicates voltage (V).

[0255] FIG. 22 shows that the light-emitting element 2 of one embodiment of the present invention is a highly efficient element. Also, 1000cd / m 2 The main initial characteristics of the light-emitting element 2 in the vicinity are shown in Table 4 below. vinegar.

[0256] [Table 4]

[0257] From the above results, it can be seen that the light-emitting element 2 fabricated in this example exhibits good current efficiency. Furthermore, it is clear that yellow-green light emission with good color purity is exhibited.

[0258] In addition, light-emitting element 2 is supplied with 25 mA / cm 2 The emission spectrum when a current is applied at a current density of 24. As shown in FIG. 24, the emission spectrum of the light-emitting element 2 has a peak at 550 nm. The photoluminescence from the organometallic complex [Ir(tBuppm)2(acac)] This suggests that there is. [Explanation of symbols]

[0259] 101 first electrode 102 EL layer 103 Second electrode 111 Hole injection layer 112 Hole transport layer 113 Light-emitting layer 114 Electron transport layer 115 Electron injection layer 116 Charge generation layer 301 First electrode 302(1) First EL layer 302(2) Second EL layer 302(n-1) EL layer (n-1) 302(n) EL layer (n) 304 Second electrode 305 Charge generation layer (I) 305(1) First charge generating layer (I) 305(2) Second charge generating layer (I) 305(n-2) (n-2)th charge generating layer (I) 305(n-1) (n-1)th charge generating layer (I) 501 Element substrate 502 pixel section 503 Driver circuit section (source line driver circuit) 504a, 504b Drive circuit section (gate line drive circuit) 505 Sealing material 506 Sealing substrate 507 Wiring 508 FPC (Flexible Printed Circuit) 509 n-channel FET 510 p-channel FET 511 Switching FET 512 Current control FET 513 First electrode (anode) 514 Insulators 515 EL layer 516 Second electrode (cathode) 517 Light-emitting element 518 Space 1100 board 1101 First electrode 1102 EL layer 1103 Second electrode 1111 Hole injection layer 1112 Hole transport layer 1113 Light-emitting layer 1114 Electron transport layer 1115 Electron injection layer 7100 Television equipment 7101 Housing 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 7302 Housing 7304 Display Panel 7305 Time Icon 7306 Other Icons 7311 7312 Operation buttons 7313 Connection terminal 7321 Band 7322 Clasp 7400 mobile phone 7401 Housing 7402 Display section 7403 Operation button 7404 External connection port 7405 Speaker 7406 Microphone 8001 Lighting equipment 8002 Lighting equipment 8003 Lighting equipment 8004 Lighting equipment 9033 Fasteners 9034 Display mode switch 9035 Power Switch 9036 Power saving mode switch 9038 Operation switch 9630 chassis 9631 Display section 9631a Display section 9631b Display section 9632a Touch Panel Area 9632b Touch panel area 9633 Solar Cells 9634 Charge / Discharge Control Circuit 9635 Battery 9636 DC / DC Converter 9637 Operation Key 9638 Converter 9639 Button

Claims

1. a light-emitting layer including a first organic compound and a second organic compound that are combined to form an exciplex and a guest material, and a hole transport layer, the light-emitting layer being disposed between a pair of electrodes; The hole transport layer of the light-emitting element has an organic compound represented by General Formula (G1). 【Chemistry 1】 (In the general formula (G1), Ar １ represents a substituted or unsubstituted fluorenyl group (excluding spirofluorenyl groups); Ar ２ represents a substituted or unsubstituted aryl group having 6 to 13 carbon atoms (excluding a spirofluorenyl group); １ represents any one of a substituted or unsubstituted dibenzofuranyl group and a substituted or unsubstituted dibenzothiophenyl group. １ , Ar ２ and A １ When Ar has a substituent, １ , Ar ２ and A １ The substituents are each independently an alkyl group having 1 to 4 carbon atoms or an aryl group having 6 to 13 carbon atoms. The aryl group does not include a heteroaryl group. The substituents may be bonded to each other to form a ring.

2. a light-emitting layer including a first organic compound and a second organic compound that are combined to form an exciplex and a guest material, and a hole transport layer, the light-emitting layer being disposed between a pair of electrodes; The hole transport layer of the light-emitting element has an organic compound represented by General Formula (G2). 【Chemistry 2】 (In the general formula (G2), Ar ３ represents a substituted or unsubstituted aryl group having 6 to 13 carbon atoms (excluding a spirofluorenyl group); ２ represents any one of a substituted or unsubstituted dibenzofuranyl group and a substituted or unsubstituted dibenzothiophenyl group. １ ~R ９ each independently represents hydrogen, an alkyl group having 1 to 4 carbon atoms, or an aryl group having 6 to 13 carbon atoms. １ and R ２ does not bond to form a ring. ３ and A ２ When Ar has a substituent, ３ and A ２ The substituents are each independently an alkyl group having 1 to 4 carbon atoms or an aryl group having 6 to 13 carbon atoms. The aryl group does not include a heteroaryl group. The substituents may be bonded to each other to form a ring.

3. a light-emitting layer including a first organic compound and a second organic compound that are combined to form an exciplex and a guest material, and a hole transport layer, the light-emitting layer being disposed between a pair of electrodes; The hole transport layer of the light-emitting element has an organic compound represented by General Formula (G3). 【Chemistry 3】 (In the general formula (G3), Ar ４ represents a substituted or unsubstituted biphenyl group (excluding a spirofluorenyl group); ３ represents any one of a substituted or unsubstituted dibenzofuranyl group and a substituted or unsubstituted dibenzothiophenyl group. １１ ~R １９ each independently represents hydrogen, an alkyl group having 1 to 4 carbon atoms, or an aryl group having 6 to 13 carbon atoms. １１ and R １２ does not bond to form a ring. ４ and A ３ When Ar has a substituent, ４ and A ３ The substituents are each independently an alkyl group having 1 to 4 carbon atoms or an aryl group having 6 to 13 carbon atoms. The aryl group does not include a heteroaryl group. The substituents may be bonded to each other to form a ring.

4. a light-emitting layer including a first organic compound and a second organic compound that are combined to form an exciplex and a guest material, and a hole transport layer, the light-emitting layer being disposed between a pair of electrodes; The hole transport layer of the light-emitting element has an organic compound represented by General Formula (G4). 【Chemistry 4】 (In the general formula (G4), X represents oxygen or sulfur, and R ２１ and R ２２ each independently represents hydrogen, an alkyl group having 1 to 4 carbon atoms, or an aryl group having 6 to 13 carbon atoms. ２１ and R ２２ do not bond to form a ring. Note that the aryl group does not include a heteroaryl group.)

5. The light-emitting layer includes a first organic compound and a second organic compound that are combined to form an exciplex, and a guest material, and is disposed between a pair of electrodes; a hole transport layer; and an electron transport layer. The hole transport layer includes an organic compound represented by general formula (G1), The electron transport layer of the light emitting device comprises a heteroaromatic compound. 【Chemistry 5】 (In the general formula (G1), Ar １ represents a substituted or unsubstituted fluorenyl group (excluding spirofluorenyl groups); Ar ２ represents a substituted or unsubstituted aryl group having 6 to 13 carbon atoms (excluding a spirofluorenyl group); １ represents any one of a substituted or unsubstituted dibenzofuranyl group and a substituted or unsubstituted dibenzothiophenyl group. １ , Ar ２ and A １ When Ar has a substituent, １ , Ar ２ and A １ The substituents are each independently an alkyl group having 1 to 4 carbon atoms or an aryl group having 6 to 13 carbon atoms. The aryl group does not include a heteroaryl group. The substituents may be bonded to each other to form a ring.

6. The light-emitting layer includes a first organic compound and a second organic compound that are combined to form an exciplex, and a guest material, and is disposed between a pair of electrodes; a hole transport layer; and an electron transport layer. The hole transport layer includes an organic compound represented by general formula (G2), The electron transport layer of the light emitting device comprises a heteroaromatic compound. 【Chemistry 6】 (In the general formula (G2), Ar ３ represents a substituted or unsubstituted aryl group having 6 to 13 carbon atoms (excluding a spirofluorenyl group); ２ represents any one of a substituted or unsubstituted dibenzofuranyl group and a substituted or unsubstituted dibenzothiophenyl group. １ ~R ９ each independently represents hydrogen, an alkyl group having 1 to 4 carbon atoms, or an aryl group having 6 to 13 carbon atoms. １ and R ２ does not bond to form a ring. ３ and A ２ When Ar has a substituent, ３ and A ２ The substituents are each independently an alkyl group having 1 to 4 carbon atoms or an aryl group having 6 to 13 carbon atoms. The aryl group does not include a heteroaryl group. The substituents may be bonded to each other to form a ring.

7. The light-emitting layer includes a first organic compound and a second organic compound that are combined to form an exciplex, and a guest material, and is disposed between a pair of electrodes; a hole transport layer; and an electron transport layer. The hole transport layer includes an organic compound represented by general formula (G3), The electron transport layer of the light emitting device comprises a heteroaromatic compound. 【Chemistry 7】 (In the general formula (G3), Ar ４ represents a substituted or unsubstituted biphenyl group (excluding a spirofluorenyl group); ３ represents any one of a substituted or unsubstituted dibenzofuranyl group and a substituted or unsubstituted dibenzothiophenyl group. １１ ~R １９ each independently represents hydrogen, an alkyl group having 1 to 4 carbon atoms, or an aryl group having 6 to 13 carbon atoms. １１ and R １２ does not bond to form a ring. ４ and A ３ When Ar has a substituent, ４ and A ３ The substituents are each independently an alkyl group having 1 to 4 carbon atoms or an aryl group having 6 to 13 carbon atoms. The aryl group does not include a heteroaryl group. The substituents may be bonded to each other to form a ring.

8. The light-emitting layer includes a first organic compound and a second organic compound that are combined to form an exciplex, and a guest material, and is disposed between a pair of electrodes; a hole transport layer; and an electron transport layer. The hole transport layer includes an organic compound represented by general formula (G4), The electron transport layer of the light emitting device comprises a heteroaromatic compound. 【Chemistry 8】 (In the general formula (G4), X represents oxygen or sulfur, and R ２１ and R ２２ each independently represents hydrogen, an alkyl group having 1 to 4 carbon atoms, or an aryl group having 6 to 13 carbon atoms. ２１ and R ２２ do not bond to form a ring. Note that the aryl group does not include a heteroaryl group.)

9. A light emitting device comprising: the light emitting element according to claim 1; and a FET.

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