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

Abstract

One embodiment of the present invention provides a novel compound that can be used as a host material for dispersing a light-emitting substance. One embodiment of the present invention provides a light-emitting element with a long service life. A compound represented by the general formula (G0). 1 represents dibenzo[f,h]quinoxaline, A 2 represents a benzo[b]naphtho[2,3‑d]furanyl group, Ar represents an arylene group having 6 to 25 carbon atoms, and the dibenzo[f,h]quinoxalinyl group, the benzo[b]naphtho[2,3‑d]furanyl group and the arylene group are each independently unsubstituted or substituted by any one of an alkyl group having 1 to 6 carbon atoms, a cycloalkyl group having 3 to 6 carbon atoms and an aryl group having 6 to 13 carbon atoms. A 1 —Ar—A 2 (G0).

Description

[0001] This application is a divisional application of the following application: Application date: April 30, 2015; Application number: 201510216810.5; Invention name: Divisional application of "Compounds, light-emitting elements, light-emitting devices, electronic devices and lighting devices". Technical Field

[0002] One embodiment of the present invention relates to a compound, a light-emitting element (also referred to as an EL element) using electroluminescence (EL), a light-emitting device, an electronic device, and a lighting device.

[0003] Note that one embodiment of the present invention is not limited to the above-mentioned technical field. One embodiment of the invention disclosed in this specification, etc., relates to an object, method, or manufacturing method. One embodiment of the present invention relates to a process, machine, product, or composition of matter. Therefore, more specifically, as an example of the technical field of one embodiment of the invention disclosed in this specification, semiconductor devices, display devices, light-emitting devices, power storage devices, storage devices, electronic devices, lighting devices, driving methods of these devices, or manufacturing methods of these devices can be cited. Background Art

[0004] In recent years, the research and development of light-emitting elements (also referred to as organic EL elements) using organic compounds as light-emitting materials has become increasingly popular. The basic structure of the light-emitting element is a structure in which a layer containing a light-emitting material is sandwiched between a pair of electrodes. By applying a voltage to the element, light emission from the light-emitting material can be obtained.

[0005] Because the above-mentioned light-emitting element is a self-luminous light-emitting element, it has advantages such as higher pixel visibility than a liquid crystal display and no need for a backlight. Therefore, the light-emitting element is considered to be suitable for a flat panel display element. In addition, the light-emitting element can be made thin and light, which is also its main advantage. Furthermore, very high-speed response is also one of the characteristics of the light-emitting element.

[0006] Since the light-emitting element can be formed into a film, surface light emission can be obtained. Therefore, it is easy to form a large-area element. This is a feature that is difficult to have with point light sources represented by incandescent lamps and LEDs or line light sources represented by fluorescent lamps, so the light-emitting element is also highly useful as a surface light source that can be used for lighting, etc.

[0007] In a light-emitting element in which an organic compound is used as a light-emitting substance and a layer containing the organic compound is provided between a pair of electrodes, by applying a voltage to the element, electrons and holes are injected from the cathode and the anode into the layer containing the organic compound, respectively, so that current flows. Furthermore, the injected electrons and holes make the organic compound excited, and light is obtained from the excited organic compound.

[0008] The excited state formed by an organic compound can be a singlet excited state or a triplet excited state. * ) is called fluorescence, while the emission from the triplet excited state (T * ) is called phosphorescence. In addition, in a light-emitting element, the statistical generation ratio of the singlet excited state and the triplet excited state is considered to be S * :T * =1:3.

[0009] In compounds that convert singlet excitation energy into luminescence (hereinafter referred to as fluorescent compounds), only luminescence (fluorescence) from the singlet excited state is observed at room temperature, and luminescence (phosphorescence) from the triplet excited state is not observed. * :T * =1:3, and the theoretical limit of the internal quantum efficiency (the ratio of generated photons to injected carriers) in a light-emitting element using a fluorescent compound is considered to be 25%.

[0010] On the other hand, in compounds that convert triplet excitation energy into luminescence (hereinafter referred to as phosphorescent compounds), luminescence (phosphorescence) from the triplet excited state is observed. In addition, in phosphorescent compounds, since intersystem crossing (i.e., transfer from the singlet excited state to the triplet excited state) is easy to occur, the internal quantum efficiency can reach 100% in theory. In other words, a higher luminous efficiency than that of fluorescent compounds can be obtained. For the above reasons, in order to realize a high-efficiency luminescent element, active research and development has been carried out on luminescent elements using phosphorescent compounds in recent years.

[0011] When the above-mentioned phosphorescent compound is used to form the light-emitting layer of the light-emitting element, in order to suppress the concentration quenching of the phosphorescent compound or the quenching caused by triplet-triplet annihilation, the phosphorescent compound is usually dispersed in a matrix composed of other compounds. In this case, the compound used as the matrix is ​​called the host material, and the compound dispersed in the matrix, such as the phosphorescent compound, is called the guest material.

[0012] When a phosphorescent compound is used as a guest material, a host material is required to have a higher triplet excitation energy (the energy difference between a ground state and a triplet excited state) than that of the phosphorescent compound.

[0013] In addition, since the singlet excitation energy (energy difference between the ground state and the singlet excited state) is higher than the triplet excitation energy, a substance having high triplet excitation energy also has high singlet excitation energy. Therefore, the above-mentioned substance having high triplet excitation energy is also effective for a light-emitting element using a fluorescent compound as a light-emitting substance.

[0014] As an example of a host material used when a phosphorescent compound is used as a guest material, a compound having a dibenzo[f,h]quinoxaline ring has been studied (for example, Patent Document 1 and Patent Document 2).

[0015] [Patent Document 1] International Patent Publication No. 03 / 058667 [Patent Document 2] Japanese Patent Publication No. 2007-189001.

[0016] There are many problems caused by materials in improving the characteristics of light-emitting elements, and to solve these problems, improvements in element structure and development of materials are being carried out. There is still room for improvement in the development of light-emitting elements in various aspects such as luminous efficiency, reliability, and cost.

[0017] Furthermore, in order to realize practical use of displays and lighting using light-emitting elements, the light-emitting elements are required to have a longer service life. Summary of the invention

[0018] In view of the above problems, one of the purposes of one embodiment of the present invention is to provide a novel compound. In addition, one of the purposes of one embodiment of the present invention is to provide a novel compound that can be used as a host material for dispersing a light-emitting substance in a light-emitting element. In addition, one of the purposes of one embodiment of the present invention is to provide a novel compound that can realize a light-emitting element with high reliability. In addition, one of the purposes of one embodiment of the present invention is to provide a compound with good film quality. In addition, one of the purposes of one embodiment of the present invention is to provide a compound with high heat resistance.

[0019] In addition, one of the purposes of one embodiment of the present invention is to provide a light-emitting element with high luminous efficiency. In addition, one of the purposes of one embodiment of the present invention is to provide a light-emitting element with low driving voltage. In addition, one of the purposes of one embodiment of the present invention is to provide a light-emitting element with long service life. In addition, one of the purposes of one embodiment of the present invention is to provide a light-emitting element with high heat resistance. In addition, one of the purposes of one embodiment of the present invention is to provide a novel light-emitting element.

[0020] In addition, one of the purposes of one embodiment of the present invention is to provide a highly reliable light-emitting device, electronic device or lighting device using the light-emitting element. In addition, one of the purposes of one embodiment of the present invention is to provide a low-power light-emitting device, electronic device or lighting device using the light-emitting element.

[0021] Note that the description of these purposes does not prevent the existence of other purposes. In addition, one mode of the present invention does not need to achieve all of the above purposes. Purposes other than the above purposes are obvious from the description of the specification, drawings, claims, etc., and can be extracted from the description.

[0022] One embodiment of the present invention is a compound represented by general formula (G0).

[0023] A 1 -Ar-A 2

[0024] (G0)

[0025] In the general formula (G0), A 1 represents dibenzo[f,h]quinoxaline, A 2 represents a benzo[b]naphtho[2,3-d]furanyl group, Ar represents an arylene group having 6 to 25 carbon atoms, and the dibenzo[f,h]quinoxalinyl group, the benzo[b]naphtho[2,3-d]furanyl group and the arylene group are each independently unsubstituted or substituted by any one of an alkyl group having 1 to 6 carbon atoms, a cycloalkyl group having 3 to 6 carbon atoms and an aryl group having 6 to 13 carbon atoms.

[0026] One embodiment of the present invention is a compound represented by general formula (G1).

[0027]

[0028] In the general formula (G1), R 7 To R 10 One of them represents a substituent represented by the general formula (G1-1), R 7 To R 10 Others in R 1 To R 6 Each independently represents any one of hydrogen, an alkyl group having 1 to 6 carbon atoms, a cycloalkyl group having 3 to 6 carbon atoms, and an aryl group having 6 to 13 carbon atoms, A represents a dibenzo[f,h]quinoxalinyl group, Ar represents an arylene group having 6 to 25 carbon atoms, and the dibenzo[f,h]quinoxalinyl group, the aryl group, and the arylene group are each independently unsubstituted or substituted by any one of an alkyl group having 1 to 6 carbon atoms, a cycloalkyl group having 3 to 6 carbon atoms, and an aryl group having 6 to 13 carbon atoms.

[0029] One embodiment of the present invention is a compound represented by general formula (G2).

[0030]

[0031] In the general formula (G2), R 1 To R 9 Each independently represents any one of hydrogen, an alkyl group having 1 to 6 carbon atoms, a cycloalkyl group having 3 to 6 carbon atoms, and an aryl group having 6 to 13 carbon atoms, A represents a dibenzo[f,h]quinoxalinyl group, Ar represents an arylene group having 6 to 25 carbon atoms, and the dibenzo[f,h]quinoxalinyl group, the aryl group, and the arylene group are each independently unsubstituted or substituted by any one of an alkyl group having 1 to 6 carbon atoms, a cycloalkyl group having 3 to 6 carbon atoms, and an aryl group having 6 to 13 carbon atoms.

[0032] One embodiment of the present invention is a compound represented by general formula (G3).

[0033]

[0034] In the general formula (G3), R 1 To R 9 and R 11 To R 19 Each independently represents any one of hydrogen, an alkyl group having 1 to 6 carbon atoms, a cycloalkyl group having 3 to 6 carbon atoms, and an aryl group having 6 to 13 carbon atoms, Ar represents an arylene group having 6 to 25 carbon atoms, and the aryl group and the arylene group each independently are unsubstituted or substituted by any one of an alkyl group having 1 to 6 carbon atoms, a cycloalkyl group having 3 to 6 carbon atoms, and an aryl group having 6 to 13 carbon atoms.

[0035] One embodiment of the present invention is a light-emitting element including any one of the compounds having the above-mentioned structures between a pair of electrodes.

[0036] One embodiment of the present invention is a light-emitting element including a layer containing a compound having a dibenzo[f,h]quinoxaline skeleton and a benzo[b]naphtho[2,3-d]furan skeleton between a pair of electrodes.

[0037] One embodiment of the present invention is a light-emitting element including a layer containing a compound between a pair of electrodes, wherein the compound is a compound in which a dibenzo[f,h]quinoxaline skeleton and a benzo[b]naphtho[2,3-d]furan skeleton are bonded via an arylene skeleton.

[0038] One embodiment of the present invention is a light-emitting device including the above-mentioned light-emitting element in a light-emitting portion. For example, the light-emitting device of one embodiment of the present invention may also include the above-mentioned light-emitting element and a transistor or a substrate. In addition, one embodiment of the present invention is an electronic device including the above-mentioned light-emitting device in a display portion. For example, an electronic device of one embodiment of the present invention may also include the above-mentioned light-emitting device and a microphone, a speaker, or an external connection terminal. In addition, one embodiment of the present invention is a lighting device including the above-mentioned light-emitting device in a light-emitting portion. For example, the lighting device of one embodiment of the present invention may also include the above-mentioned light-emitting device, a pillar, a housing, or a cover.

[0039] Note that the light-emitting device in this specification includes a display device using a light-emitting element. In addition, the following modules sometimes include a light-emitting device: a module in which a light-emitting element is mounted with a connector such as an anisotropic conductive film or TCP (Tape Carrier Package); a module in which a printed circuit board is provided at the end of the TCP; or a module in which an IC (integrated circuit) is directly mounted on the light-emitting element by COG (Chip On Glass). Furthermore, lighting equipment and the like sometimes include a light-emitting device.

[0040] The compound represented by the general formula (G4) used in synthesizing the compound of one embodiment of the present invention is also one embodiment of the present invention.

[0041]

[0042] In the general formula (G4), R 1 To R 9 each independently represents any one of hydrogen, an alkyl group having 1 to 6 carbon atoms, a cycloalkyl group having 3 to 6 carbon atoms, and an aryl group having 6 to 13 carbon atoms, and R 10 represents any one of chlorine, boron, iodine, a boronic acid group and an organic boron group. The aryl group is unsubstituted or substituted by any one of an alkyl group having 1 to 6 carbon atoms, a cycloalkyl group having 3 to 6 carbon atoms and an aryl group having 6 to 13 carbon atoms.

[0043] The compound represented by structural formula (201) used in synthesizing the compound of one embodiment of the present invention is also one embodiment of the present invention.

[0044]

[0045] By one embodiment of the present invention, a novel compound can be provided. In addition, by one embodiment of the present invention, a novel compound that can be used as a main material for dispersing a luminescent substance in a luminescent element can be provided. In addition, by one embodiment of the present invention, a novel compound that can realize a luminescent element with high reliability can be provided. In addition, by one embodiment of the present invention, a compound with good film quality can be provided. In addition, by one embodiment of the present invention, a compound with high heat resistance can be provided.

[0046] In addition, by one embodiment of the present invention, a light-emitting element with high luminous efficiency can be provided. In addition, by one embodiment of the present invention, a light-emitting element with low driving voltage can be provided. In addition, by one embodiment of the present invention, a light-emitting element with long service life can be provided. In addition, by one embodiment of the present invention, a light-emitting element with high heat resistance can be provided. In addition, by one embodiment of the present invention, a novel light-emitting element can be provided.

[0047] In addition, according to one embodiment of the present invention, a highly reliable light-emitting device, electronic device or lighting device using the light-emitting element can be provided. In addition, according to one embodiment of the present invention, a low-power light-emitting device, electronic device or lighting device using the light-emitting element can be provided.

[0048] Note that the description of these effects does not prevent the existence of other effects. In addition, one mode of the present invention does not need to have all of the above effects. Effects other than the above effects are obvious from the description of the specification, drawings, claims, etc., and can be extracted from the description. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] Figures 1A to 1D An example of a light-emitting element according to one embodiment of the present invention is shown;

[0050] Figure 2A and Figure 2B An example of a light-emitting device according to one embodiment of the present invention is shown;

[0051] FIG. 3A to FIG. 3C An example of a light-emitting device according to one embodiment of the present invention is shown;

[0052] FIG. 4A to FIG. 4E An example of an electronic device is shown;

[0053] FIG. 5A to FIG. 5I An example of an electronic device is shown;

[0054] Fig. 6A and Figure 6B An example of a lighting device is shown;

[0055] Fig. 7A and Figure 7B It is 8-chlorobenzo[b]naphtho[2,3-d]furan 1 H NMR spectra;

[0056] Fig. 8A and Figure 8B It is 2-[3'-(benzo[b]naphtho[2,3-d]furan-8-yl)biphenyl-3-yl]dibenzo[f,h]quinoxaline (abbreviation: 2mBnf(II)BPDBq) 1 H NMR spectra;

[0057] Fig. 9A and Fig. 9B The absorption spectrum and luminescence spectrum of the toluene solution of 2mBnf(II)BPDBq are shown;

[0058] Fig. 10A and Fig. 10B The absorption spectrum and luminescence spectrum of the thin film of 2mBnf(II)BPDBq are shown;

[0059] Fig.11A and Fig. 11B The results of LC / MS analysis of 2mBnf(II)BPDBq are shown;

[0060] Fig.12 A light emitting element of an embodiment is shown;

[0061] Fig.13 The voltage-luminance characteristics of the light-emitting element of Example 2 are shown;

[0062] Fig.14 The luminance-current efficiency characteristics of the light-emitting element of Example 2 are shown;

[0063] Fig.15 The voltage-current characteristics of the light-emitting element of Example 2 are shown;

[0064] Fig.16 The light emission spectrum of the light emitting element of Example 2 is shown;

[0065] Fig.17 The results of the reliability test of the light emitting element of Example 2 are shown;

[0066] Fig.18 The voltage-current characteristics of the light-emitting element of Example 3 are shown;

[0067] Fig.19 Brightness-external quantum efficiency characteristics of the light-emitting element of Example 3 are shown. DETAILED DESCRIPTION

[0068] The embodiments are described in detail with reference to the accompanying drawings. However, the present invention is not limited to the following description, and a person skilled in the art can easily understand that the mode and details can be transformed into various forms without departing from the purpose and scope of the present invention. Therefore, the present invention should not be interpreted as being limited to the contents described in the embodiments shown below.

[0069] Note that in the structure of the invention described below, the same reference numeral is used in common between different drawings to represent the same part or part having the same function, and its repeated description is omitted. In addition, when representing a part having the same function, the same hatching is sometimes used without adding a reference numeral in particular.

[0070] In addition, for ease of understanding, the position, size, range, etc. of each component shown in the drawings and the like may not represent the actual position, size, range, etc. Therefore, the disclosed invention is not necessarily limited to the position, size, range, etc. disclosed in the drawings and the like.

[0071] In addition, depending on the situation or state, "film" and "layer" may be interchanged. For example, "conductive layer" may be interchanged with "conductive film". Also, "insulating film" may be interchanged with "insulating layer".

[0072] Implementation Method 1

[0073] In this embodiment, a compound which is one embodiment of the present invention is described.

[0074] One embodiment of the present invention is a compound in which a dibenzo[f,h]quinoxaline skeleton and a benzo[b]naphtho[2,3-d]furan skeleton are bonded via an arylene skeleton.

[0075] The dibenzo[f,h]quinoxaline skeleton has a planar structure. Compounds with a planar structure are easy to crystallize. The service life of a light-emitting element using a compound that is easy to crystallize is short. However, in the compound of one embodiment of the present invention, the dibenzo[f,h]quinoxaline skeleton is bonded to the benzo[b]naphtho[2,3-d]furan skeleton through an arylene skeleton, so the compound has a spatially bulky structure. The compound of one embodiment of the present invention is not easy to crystallize, so the reduction in the service life of the light-emitting element can be suppressed. The compound of one embodiment of the present invention has: a benzo[b]naphtho[2,3-d]furan skeleton formed by condensation of a benzene ring and a naphthalene ring with a furan skeleton; and a dibenzo[f,h]quinoxaline skeleton formed by condensation of two benzene rings with a quinoxaline skeleton. Therefore, the compound of one embodiment of the present invention has very high heat resistance. And, by using it for a light-emitting element, a component with high heat resistance and long service life can be realized.

[0076] In addition, when a compound that is not easy to accept electrons or holes is used as a main material of the light-emitting layer, the recombination area of ​​electrons and holes is concentrated at the interface between the light-emitting layer and other layers, resulting in a reduction in the service life of the light-emitting element. On the other hand, because the compound of one embodiment of the present invention has a dibenzo [f, h] quinoxaline skeleton of an electron transport skeleton and a benzo [b] naphtho [2,3-d] furan skeleton of a hole transport skeleton, it is easy to accept electrons and holes. Therefore, it can be considered that by using a compound of one embodiment of the present invention as a main material of the light-emitting layer, the recombination of electrons and holes occurs in a large area of ​​the light-emitting layer, thereby suppressing the reduction in the service life of the light-emitting element.

[0077] In addition, compared with the compound in which the dibenzo[f,h]quinoxaline skeleton and the benzo[b]naphtho[2,3-d]furan skeleton are directly bonded, the compound of one embodiment of the present invention in which the two skeletons are bonded by an arylene group can further suppress the expansion of the conjugated system, and can prevent the narrowing of the band gap and the reduction of the triplet excitation energy. In addition, the compound of one embodiment of the present invention has the advantages of showing high heat resistance and good film quality. Specifically, the thin film of the compound of one embodiment of the present invention is not easy to change in morphology, such as not easy to agglomerate in the atmosphere, not easy to crystallize at high temperature, etc.

[0078] Since the compound of one embodiment of the present invention has a wide band gap, it can be suitably used as a host material for dispersing the light-emitting substance of the light-emitting layer in the light-emitting element. In addition, the compound of one embodiment of the present invention has a sufficiently high triplet excitation energy required to excite a phosphorescent compound that emits light in the wavelength range of red to green, and is therefore suitable for a host material for dispersing the phosphorescent compound.

[0079] Note that when the triplet excitation energy of the host material is too high, the light-emitting element may be easily degraded by being easily affected by quenching factors. By using the compound of one embodiment of the present invention, a light-emitting element that is not easily degraded by being affected by quenching factors can be realized.

[0080] Furthermore, since the compound of one embodiment of the present invention is a substance with a high electron-transporting property, it is suitable as a material for an electron-transporting layer in a light-emitting element.

[0081] Therefore, the compound of one embodiment of the present invention is suitable for use as a material for organic devices such as a light-emitting element or an organic transistor.

[0082] One embodiment of the present invention is a compound represented by general formula (G0).

[0083] A 1 -Ar-A 2

[0084] (G0)

[0085] In the general formula (G0), A 1 represents dibenzo[f,h]quinoxaline, A 2 represents a benzo[b]naphtho[2,3-d]furanyl group, Ar represents an arylene group having 6 to 25 carbon atoms, and the dibenzo[f,h]quinoxalinyl group, the benzo[b]naphtho[2,3-d]furanyl group and the arylene group are each independently unsubstituted or substituted by any one of an alkyl group having 1 to 6 carbon atoms, a cycloalkyl group having 3 to 6 carbon atoms and an aryl group having 6 to 13 carbon atoms.

[0086] One embodiment of the present invention is a compound represented by the general formula (G1). When a substituent represented by the general formula (G1-1) is bonded to the benzene ring of benzo[b]naphtho[2,3-d]furan, the energy level of triplet excitation energy (T 1 energy level) can be improved.

[0087]

[0088] In the general formula (G1), R 7 To R 10 One of them represents a substituent represented by the general formula (G1-1), R 7 To R 10 Others in R 1 To R 6 Each independently represents any one of hydrogen, an alkyl group having 1 to 6 carbon atoms, a cycloalkyl group having 3 to 6 carbon atoms, and an aryl group having 6 to 13 carbon atoms, A represents a dibenzo[f,h]quinoxalinyl group, Ar represents an arylene group having 6 to 25 carbon atoms, and the dibenzo[f,h]quinoxalinyl group, the aryl group, and the arylene group are each independently unsubstituted or substituted by any one of an alkyl group having 1 to 6 carbon atoms, a cycloalkyl group having 3 to 6 carbon atoms, and an aryl group having 6 to 13 carbon atoms.

[0089] In the general formula (G1), the substituent represented by the general formula (G1-1) is bonded to the 8-position of the benzo[b]naphtho[2,3-d]furan skeleton (i.e., R 10 is a substituent represented by the general formula (G1-1), T 1 The energy level is very high, so it is particularly preferred.

[0090] One embodiment of the present invention is a compound represented by General Formula (G2).

[0091]

[0092] In the general formula (G2), R 1 To R 9Each independently represents any one of hydrogen, an alkyl group having 1 to 6 carbon atoms, a cycloalkyl group having 3 to 6 carbon atoms, and an aryl group having 6 to 13 carbon atoms, A represents a dibenzo[f,h]quinoxalinyl group, Ar represents an arylene group having 6 to 25 carbon atoms, and the dibenzo[f,h]quinoxalinyl group, the aryl group, and the arylene group are each independently unsubstituted or substituted by any one of an alkyl group having 1 to 6 carbon atoms, a cycloalkyl group having 3 to 6 carbon atoms, and an aryl group having 6 to 13 carbon atoms.

[0093] In the general formula (G2), when Ar is bonded to the 2-position, 6-position or 7-position of the dibenzo[f,h]quinoxaline skeleton, it is easy to purify the product and improve T 1 When Ar is bonded to the 2-position, the synthesis is easier than when Ar is bonded to the 6-position or 7-position, so the compound can be provided at a low cost, which is preferred. When Ar is bonded to the 6-position, T is lower than when Ar is bonded to the 2-position or 7-position. 1 When Ar is bonded to the 7-position, T is higher than when Ar is bonded to the 2-position. 1 When Ar is bonded to the 6-position or the 7-position, it is preferred because Ar often has higher solubility than when Ar is bonded to the 2-position, and can be easily purified to achieve high purity.

[0094] One embodiment of the present invention is a compound represented by General Formula (G3).

[0095]

[0096] In the general formula (G3), R 1 To R 9 and R 11 To R 19 Each independently represents any one of hydrogen, an alkyl group having 1 to 6 carbon atoms, a cycloalkyl group having 3 to 6 carbon atoms, and an aryl group having 6 to 13 carbon atoms, Ar represents an arylene group having 6 to 25 carbon atoms, and the aryl group and the arylene group are each independently unsubstituted or substituted by any one of an alkyl group having 1 to 6 carbon atoms, a cycloalkyl group having 3 to 6 carbon atoms, and an aryl group having 6 to 13 carbon atoms.

[0097] As the specific structure of Ar shown in general formula (G1-1), general formula (G2) and general formula (G3), for example, the substituents shown in structural formula (1-1) to structural formula (1-18) can be cited. Ar can also have any one of an alkyl group having 1 to 4 carbon atoms, a cycloalkyl group having 3 to 6 carbon atoms and an aryl group having 6 to 13 carbon atoms as a substituent. As the above-mentioned aryl group having 6 to 13 carbon atoms, for example, phenyl, naphthyl, fluorenyl, etc. can be cited. Specifically, structural formula (1-12), structural formula (1-13), structural formula (1-15) and structural formula (1-18) represent the structure when Ar has a substituent. Note that the structure when Ar has a substituent is not limited to this.

[0098]

[0099] The ring possessed by Ar is preferably one or more rings selected from a benzene ring, a fluorene ring and a naphthalene ring. Ar is preferably a substituent containing one or more rings selected from a benzene ring, a fluorene ring and a naphthalene ring, such as a phenylene, a biphenylene, a terphenylene, a quaterphenylene, a naphthalene-diyl, a 9H-fluorene-diyl, etc. The triplet excitation energy of the compound of one embodiment of the present invention can be increased.

[0100] As R shown in the general formula (G1) to the general formula (G3) 1 To R 19 The specific structure of can be, for example, the substituents represented by structural formula (2-1) to structural formula (2-23). 1 To R 19 When it is an aryl group, the aryl group may further have any one of an alkyl group having 1 to 4 carbon atoms, a cycloalkyl group having 3 to 6 carbon atoms, and an aryl group having 6 to 13 carbon atoms as a substituent. Examples of the aryl group having 6 to 13 carbon atoms include phenyl, naphthyl, and fluorenyl. Specifically, structural formulas (2-13) to (2-22) represent structures when the aryl group has a substituent. Note that R 1 To R 19 The structure when having a substituent is not limited thereto.

[0101]

[0102] Specific examples of the compound of one embodiment of the present invention include heterocyclic compounds represented by structural formula (100) to structural formula (155). Note that the present invention is not limited to these structures.

[0103]

[0104]

[0105]

[0106]

[0107]

[0108]

[0109]

[0110]

[0111] As a method for synthesizing a compound of one embodiment of the present invention, various reactions can be used. 10 A method for synthesizing a compound having a substituent represented by the general formula (G1-1) (ie, a compound represented by the general formula (G2)) Note that the method for synthesizing the compound of one embodiment of the present invention is not limited to the following synthesis method.

[0112] The compound represented by the general formula (G2) can be synthesized by the following synthesis scheme (A-1). In other words, the compound represented by the general formula (G2) can be obtained by coupling a benzo[b]naphtho[2,3-d]furan compound (Compound 1) with a dibenzo[f,h]quinoxaline compound (Compound 2).

[0113]

[0114] In the synthesis scheme (A-1), A represents a substituted or unsubstituted dibenzo[f,h]quinoxalinyl group, Ar represents a substituted or unsubstituted arylene group having 6 to 25 carbon atoms, and X 1 and X 2 R each independently represents any one of halogen, trifluoromethylsulfonyl, boronic acid, organoboron, magnesium halide, and organotin. 1 To R 9 Each independently represents any one of hydrogen, an alkyl group having 1 to 6 carbon atoms, a cycloalkyl group having 3 to 6 carbon atoms, and a substituted or unsubstituted aryl group having 6 to 13 carbon atoms.

[0115] In the synthesis scheme (A-1), when the Suzuki-Miyaura coupling reaction using a palladium catalyst is carried out, X 1 and X 2Respectively independently represent halogen, boric acid group, organic boron group or trifluoromethylsulfonyl group. The halogen preferably represents iodine, bromine or chlorine. In the above reaction, palladium compounds such as bis(dibenzylideneacetone)palladium(0), palladium acetate(II), [1,1'-bis(diphenylphosphino)ferrocene]dichloropalladium(II), tetrakis(triphenylphosphine)palladium(0) and tri(tert-butyl)phosphine, tri(n-hexyl)phosphine, tricyclohexylphosphine, di(1-adamantyl)-n-butylphosphine, 2-dicyclohexylphosphino-2',6'-dimethoxybiphenyl, tri(o-tolyl)phosphine and the like can be used. In the above reaction, organic bases such as sodium tert-butoxide, inorganic bases such as potassium carbonate, cesium carbonate, sodium carbonate and the like can be used. In the above reaction, toluene, xylene, benzene, tetrahydrofuran, dioxane, ethanol, methanol, water and the like can be used as solvents. Note that the reagents that can be used for the above reaction are not limited to the above reagents.

[0116] The reaction carried out in the synthesis scheme (A-1) is not limited to the Suzuki-Miyaura coupling reaction, and the Ueda-Kosugi-Stille coupling reaction using an organic tin compound, the Kumada-Tamao-Corriu coupling reaction using a Grignard reagent, the Negishi coupling reaction using an organic zinc compound, the reaction using copper or a copper compound, etc. can also be used.

[0117] In addition, by using the same method as above, a compound in which a substituent represented by the general formula (G1-1) is bonded to any one of the 1- to 10-positions of benzo[b]naphtho[2,3-d]furan (i.e., R in the general formula (G1)) can be synthesized. 1 To R 10 A compound in which any one of them is a substituent represented by the general formula (G1-1)).

[0118] The compound of this embodiment can be synthesized by the above method.

[0119] In addition, the following compound used in synthesizing a compound of one embodiment of the present invention is also one embodiment of the present invention, namely a compound in which a halogen (iodine, bromine or chlorine), a trifluoromethylsulfonyl group, a boronic acid group, an organic boron group, a magnesium halide group or an organic tin group is bonded to the 8-position of benzo[b]naphtho[2,3-d]furan.

[0120] Specifically, one embodiment of the present invention is a compound represented by General Formula (G4).

[0121]

[0122] In the general formula (G4), R 1 To R 9 each independently represents any one of hydrogen, an alkyl group having 1 to 6 carbon atoms, a cycloalkyl group having 3 to 6 carbon atoms, and an aryl group having 6 to 13 carbon atoms, and R 10represents any one of chlorine, bromine, boron, iodine, a boronic acid group and an organic boron group. The aryl group is unsubstituted or substituted by any one of an alkyl group having 1 to 6 carbon atoms, a cycloalkyl group having 3 to 6 carbon atoms and an aryl group having 6 to 13 carbon atoms.

[0123] <Method for synthesizing the compound represented by general formula (G4)>

[0124] A method for synthesizing the compound represented by the general formula (G4) is described below. Note that the method for synthesizing the compound represented by the general formula (G4) according to one embodiment of the present invention is not limited to the following method.

[0125] The compound represented by the general formula (G4) can be synthesized, for example, by the following synthesis schemes (X-1) to (X-2).

[0126] First, as shown in Synthesis Scheme (X-1), by coupling Compound 3 with Compound 4, an alcohol (Compound 5) can be obtained.

[0127]

[0128] In the synthesis scheme (X-1), R 1 To R 9 each independently represents any one of hydrogen, an alkyl group having 1 to 6 carbon atoms, a cycloalkyl group having 3 to 6 carbon atoms, and an aryl group having 6 to 13 carbon atoms, and R 10 represents any one of chlorine, bromine, boron, iodine, a boronic acid group and an organic boron group, and X 1 and X 2 Each independently represents any one of halogen, trifluoromethylsulfonyl group, boronic acid group, organic boron group, magnesium halide group and organic tin group.

[0129] In the synthesis scheme (X-1), the hydroxyl group of compound 4 may be protected by an alkyl group or the like.

[0130] In the synthesis scheme (X-1), when the Suzuki-Miyaura coupling reaction using a palladium catalyst is carried out, X 1 and X 2Respectively independently represent halogen, boric acid group, organic boron group or trifluoromethylsulfonyl group. The halogen preferably represents iodine, bromine or chlorine. In the above reaction, palladium compounds such as bis(dibenzylideneacetone)palladium(0), palladium acetate(II), [1,1'-bis(diphenylphosphino)ferrocene]dichloropalladium(II), tetrakis(triphenylphosphine)palladium(0) and tri(tert-butyl)phosphine, tri(n-hexyl)phosphine, tricyclohexylphosphine, di(1-adamantyl)-n-butylphosphine, 2-dicyclohexylphosphino-2',6'-dimethoxybiphenyl, tri(o-tolyl)phosphine and the like can be used. In the above reaction, organic bases such as sodium tert-butoxide, inorganic bases such as potassium carbonate, cesium carbonate, sodium carbonate and the like can be used. In the above reaction, toluene, xylene, benzene, tetrahydrofuran, dioxane, ethanol, methanol, water and the like can be used as solvents. Note that the reagents that can be used for the above reaction are not limited to the above reagents.

[0131] The reaction carried out in the synthesis scheme (X-1) is not limited to the Suzuki-Miyaura coupling reaction, and the Ueda-Kosugi-Stille coupling reaction using an organic tin compound, the Kumada-Tamao-Corriu coupling reaction using a Grignard reagent, the Negishi coupling reaction using an organic zinc compound, the reaction using copper or a copper compound, etc. can also be used.

[0132] Next, as shown in Synthesis Scheme (X-2), a benzo[b]naphtho[2,3-d]furan derivative (Compound 6) can be synthesized by forming an ether bond in an alcohol (Compound 5) through Williamson synthesis.

[0133]

[0134] In the synthesis scheme (X-2), R 1 To R 9 each independently represents any one of hydrogen, an alkyl group having 1 to 6 carbon atoms, a cycloalkyl group having 3 to 6 carbon atoms, and an aryl group having 6 to 13 carbon atoms, and R 10 It represents any one of chlorine, bromine, boron, iodine, a boronic acid group and an organic boron group.

[0135] In the synthesis scheme (X-1), when the hydroxyl group of compound 4 is protected by an alkyl group or the like, it is deprotected by boron tribromide or the like before proceeding to the synthesis scheme (X-2) and then restored to the hydroxyl group.

[0136] In the synthesis scheme (X-2), when Williamson synthesis is performed, a base such as potassium carbonate or sodium carbonate can be used, and a solvent such as N-methyl-2-pyrrolidone (NMP) can be used. The base and solvent that can be used are not limited to these.

[0137] Next, referring to the synthesis scheme (X-3), R 10A method for synthesizing the compound of one embodiment of the present invention from a compound (Compound 7) when it is chlorine will be described.

[0138]

[0139] In the synthetic scheme (X-3), R 1 To R 9 Each independently represents any one of hydrogen, an alkyl group having 1 to 6 carbon atoms, a cycloalkyl group having 3 to 6 carbon atoms, and an aryl group having 6 to 13 carbon atoms.

[0140] In the synthesis scheme (X-3), lithium replaces the chlorine in the chloride (compound 7) to form an organic lithium compound (compound 8), and then the organic lithium compound (compound 8) can be used to form a boric acid compound (compound 9), a bromide (compound 10), and an iodide (compound 11) respectively through a boration reaction, a bromination reaction, or an iodination reaction.

[0141] As reagents that can be used in the synthesis scheme (X-3), organic lithium reagents such as n-butyl lithium and tert-butyl lithium can be used when synthesizing organic lithium compounds, trimethyl borate can be used when performing boration reactions, iodine can be used when performing iodination reactions, and bromine can be used when performing bromination reactions. The reagents that can be used are not limited to the above reagents.

[0142] Next, referring to the synthesis scheme (X-4), R in the general formula (G4) 10 The synthesis method of the compound (Compound 12) in the case of 4,4,5,5-tetramethyl-1,3,2-dioxaborolane is described below.

[0143]

[0144] In the synthetic scheme (X-4), R 1 To R 9 each independently represents any one of hydrogen, an alkyl group having 1 to 6 carbon atoms, a cycloalkyl group having 3 to 6 carbon atoms, and an aryl group having 6 to 13 carbon atoms, and R 10 It represents any one of chlorine, bromine and boron.

[0145] As shown in synthesis scheme (X-4), by carrying out the coupling reaction of compound 6 of halide and pinacol boronic acid ester, organic boron compound (compound 12) can be obtained. In synthesis scheme (X-4), palladium compounds such as bis(dibenzylideneacetone) palladium (0), palladium acetate (II), [1,1'-bis(diphenylphosphino) ferrocene] palladium chloride (II), tetrakis(triphenylphosphine) palladium (0) and tri(tert-butyl) phosphine, tri(n-hexyl) phosphine, tricyclohexyl phosphine, di(1-adamantyl)-n-butyl phosphine, 2-dicyclohexylphosphino-2', 6'-dimethoxybiphenyl, tri(o-tolyl) phosphine can be used. In the above reaction, inorganic bases such as organic bases such as sodium tert-butoxide, potassium carbonate, cesium carbonate, sodium carbonate, etc. can be used. In the above reaction, as solvent, toluene, xylene, benzene, tetrahydrofuran, dioxane, ethanol, methanol, water, etc. can be used. Note that reagents that can be used in the above reaction are not limited to the above reagents.

[0146] Specific examples of the compound of one embodiment of the present invention include compounds represented by structural formula (201) to structural formula (215). Note that the present invention is not limited to these structures.

[0147]

[0148] The compound of this embodiment is suitable as a host material for dispersing a light-emitting substance of a light-emitting layer in a light-emitting element or a material for an electron transport layer. By using the compound of this embodiment, a light-emitting element with a long lifetime can be obtained.

[0149] This embodiment mode can be combined with other embodiment modes as appropriate.

[0150] Implementation Method 2

[0151] In this embodiment, using Figures 1A to 1D A light-emitting element according to one embodiment of the present invention will be described.

[0152] The light-emitting element of one embodiment of the present invention has a layer containing the compound described in Embodiment 1 between a pair of electrodes.

[0153] The compound of the light-emitting element of one embodiment of the present invention has a spatially large structure. In addition, the compound has high heat resistance. In addition, the film quality of the compound is good. Therefore, by using the compound, a light-emitting element with a long service life can be realized.

[0154] In addition, because the compound has a dibenzo[f,h]quinoxaline skeleton of an electron transport skeleton and a benzo[b]naphtho[2,3-d]furan skeleton of a hole transport skeleton, it can accept electrons and holes. Therefore, by using the compound as a host material of the light-emitting layer, electrons and holes are recombined in the light-emitting layer, thereby suppressing the reduction in the service life of the light-emitting element. That is, a preferred embodiment of the present invention is a light-emitting element having a light-emitting layer between a pair of electrodes, the light-emitting layer comprising a light-emitting substance (guest material) and a host material for dispersing the light-emitting substance, and the host material is the above-mentioned compound.

[0155] The light-emitting element of this embodiment has a layer (EL layer) containing a light-emitting organic compound between a pair of electrodes (a first electrode and a second electrode). One of the first electrode and the second electrode is used as an anode, and the other is used as a cathode. In this embodiment, the EL layer contains a compound of one embodiment of the present invention described in Embodiment 1.

[0156] <<Structural example of light emitting element>>

[0157] Figure 1A The light-emitting element shown has an EL layer 203 between a first electrode 201 and a second electrode 205. In this embodiment, the first electrode 201 serves as an anode, and the second electrode 205 serves as a cathode.

[0158] When a voltage higher than the threshold voltage of the light-emitting element is applied between the first electrode 201 and the second electrode 205, holes are injected into the EL layer 203 from the first electrode 201 side, and electrons are injected into the EL layer 203 from the second electrode 205 side. The injected electrons and holes are recombined in the EL layer 203, whereby a light-emitting substance included in the EL layer 203 emits light.

[0159] The EL layer 203 includes at least a light-emitting layer 303 containing a light-emitting substance.

[0160] In addition, by providing a plurality of light-emitting layers in the EL layer and making the light-emitting colors of each layer different from each other, light of a desired color can be obtained as the entire light-emitting element. For example, in a light-emitting element having two light-emitting layers, by making the light-emitting colors of the first light-emitting layer and the second light-emitting layer complementary colors, white light can also be obtained as the entire light-emitting element. Note that "complementary colors" refer to a color relationship in which a non-color is obtained when colors are mixed. In other words, white light can be obtained by mixing light obtained from substances that emit light of colors in a complementary color relationship. The same principle can be applied to light-emitting elements having more than three light-emitting layers.

[0161] The EL layer 203 may include, in addition to the light-emitting layer, a layer containing a substance with high hole injection property, a substance with high hole transport property, a substance with high electron transport property, a substance with high electron injection property, or a bipolar substance (a substance with high electron transport property and hole transport property). As the EL layer 203, a low molecular weight compound, a high molecular weight compound, or an inorganic compound may be used.

[0162] Figure 1B The light-emitting element shown has an EL layer 203 between a first electrode 201 and a second electrode 205, in which a hole injection layer 301, a hole transport layer 302, a light-emitting layer 303, an electron transport layer 304 and an electron injection layer 305 are stacked in order from the first electrode 201 side.

[0163] The compound of one embodiment of the present invention is preferably used in the light-emitting layer 303 or the electron-transporting layer 304. In this embodiment, a case where the compound of one embodiment of the present invention is used as a host material for the light-emitting layer 303 is described as an example.

[0164] like Figure 1C and Figure 1D As in the light-emitting element shown in FIG. 1 , a plurality of EL layers may be stacked between the first electrode 201 and the second electrode 205. In this case, an intermediate layer 207 is preferably provided between the stacked EL layers. The intermediate layer 207 includes at least a charge generation region.

[0165] For example, Figure 1C The light-emitting element shown has an intermediate layer 207 between the first EL layer 203a and the second EL layer 203b. Figure 1D The light-emitting element shown has n EL layers (n is a natural number greater than or equal to 2), and an intermediate layer 207 is provided between the EL layers.

[0166] The behavior of electrons and holes in the intermediate layer 207 provided between the EL layer 203(m) and the EL layer 203(m+1) is described. When a voltage higher than the threshold voltage of the light-emitting element is applied between the first electrode 201 and the second electrode 205, holes and electrons are generated in the intermediate layer 207, and the holes move to the EL layer 203(m+1) provided on the second electrode 205 side, and the electrons move to the EL layer 203(m) provided on the first electrode 201 side. The holes injected into the EL layer 203(m+1) recombine with the electrons injected from the second electrode 205 side, so that the light-emitting material contained in the EL layer 203(m+1) emits light. In addition, the electrons injected into the EL layer 203(m) recombine with the holes injected from the first electrode 201 side, so that the light-emitting material contained in the EL layer 203(m) emits light. Therefore, the holes and electrons generated in the intermediate layer 207 cause light emission in different EL layers.

[0167] When the same structure as the intermediate layer is formed in between, a plurality of EL layers may be provided in contact with each other without the intermediate layer. For example, when a charge generation region is formed on one surface of the EL layer, another EL layer may be provided in contact with the surface.

[0168] In addition, by making the emission colors of each EL layer different from each other, it is possible to obtain emission of a desired color as the entire light-emitting element. For example, in a light-emitting element having two EL layers, by making the emission colors of the first EL layer and the second EL layer complementary colors, it is also possible to obtain white emission as the entire light-emitting element. The same principle can be applied to light-emitting elements having three or more EL layers.

[0169] <<Materials for light-emitting elements>>

[0170] Materials that can be used for each layer are shown below. Note that each layer is not limited to a single layer, and may be a stack of two or more layers.

[0171] <Anode>

[0172] The electrode used as the anode (in this embodiment, the first electrode 201) can be formed using one or more of a conductive metal, a conductive alloy, a conductive compound, etc. It is particularly preferable to use a material with a large work function (4.0 eV or more). For example, indium tin oxide (ITO), indium tin oxide containing silicon or silicon oxide, indium zinc oxide, indium oxide containing tungsten oxide and zinc oxide, graphene, gold, platinum, nickel, tungsten, chromium, molybdenum, iron, cobalt, copper, palladium, titanium, or a nitride of a metal material (e.g., titanium nitride), etc. can be cited.

[0173] When the anode is in contact with the charge generation region, a variety of conductive materials can be used regardless of the size of the work function, for example, aluminum, silver, alloys containing aluminum, etc. can be used.

[0174] <Cathode>

[0175] The electrode used as the cathode (in this embodiment, the second electrode 205) can be formed using one or more of a conductive metal, a conductive alloy, a conductive compound, etc. It is particularly preferred to use a material with a small work function (3.8 eV or less). For example, an element belonging to Group 1 or Group 2 of the periodic table (for example, an alkali metal such as lithium or cesium, an alkaline earth metal such as calcium or strontium, magnesium, etc.), an alloy containing the above elements (for example, Mg-Ag or Al-Li), a rare earth metal such as europium or ytterbium, an alloy containing a rare earth metal, aluminum, silver, etc. can be used.

[0176] When the cathode is in contact with the charge generation region, a variety of conductive materials can be used regardless of the size of the work function, for example, ITO, indium tin oxide containing silicon or silicon oxide, etc. can be used.

[0177] Each electrode can be formed by vacuum deposition or sputtering. In addition, when silver paste or the like is used, a coating method or an inkjet method can be used.

[0178] <Luminous Layer>

[0179] The light-emitting layer 303 is a layer containing a light-emitting substance. In this embodiment, the following case is described as an example, that is, the light-emitting layer 303 contains a guest material and a host material that disperses the guest material, and the compound of one embodiment of the present invention is used as the host material. The compound of one embodiment of the present invention is suitable as a host material of the light-emitting layer when the light-emitting substance is a fluorescent compound or a phosphorescent compound that emits light in the wavelength range of red to green.

[0180] In the light-emitting layer, by dispersing the guest material in the host material, crystallization of the light-emitting layer can be suppressed. In addition, concentration quenching due to high concentration of the guest material can be suppressed and the light emission efficiency of the light-emitting element can be improved.

[0181] In addition to the guest material and the host material, the light-emitting layer may also include other compounds. In addition, in addition to the light-emitting layer including the compound of one embodiment of the present invention, the light-emitting element of one embodiment of the present invention may also have other light-emitting layers. At this time, as the light-emitting substance, a fluorescent compound, a phosphorescent compound or a substance exhibiting thermally activated delayed fluorescence can be used, and as the host material, a compound that easily accepts electrons or a compound that easily accepts holes described later can be used.

[0182] In addition, the T of the host material (or a material other than the guest material contained in the light-emitting layer)1 The energy level is preferably higher than the T 1 energy level. This is because if the T 1 The energy level is lower than the T of the guest material 1 If the energy level is too low, the host material quenches the triplet excitation energy of the guest material that contributes to luminescence, resulting in a decrease in luminescence efficiency.

[0183] Here, in order to improve the energy transfer efficiency from the host material to the guest material, it is preferable to consider the well-known Förster kinetics as an energy transfer mechanism between molecules. Due to the dual-electron interaction mechanism (dipole-dipole interaction) and the Dexter mechanism (electron exchange interaction), the emission spectrum of the host material (equivalent to the fluorescence spectrum when considering the energy transfer in the singlet excited state, and equivalent to the phosphorescence spectrum when considering the energy transfer in the triplet excited state) and the absorption spectrum of the guest material (more specifically, the spectrum in the absorption band on the longest wavelength (low energy) side) overlaps greatly.

[0184] However, it is usually difficult to overlap the fluorescence spectrum of the host material with the absorption spectrum in the absorption band on the longest wavelength (low energy) side of the guest material. This is because the phosphorescence spectrum of the host material is on the longer wavelength (low energy) side than the fluorescence spectrum. 1 The energy level is lower than the T of the phosphorescent compound 1 On the other hand, in order to avoid the quenching problem, when the T 1 The energy level is higher than the T of the phosphorescent compound. 1 When the energy level is low, the fluorescence spectrum of the host material drifts to the short wavelength (high energy) side, so the fluorescence spectrum does not overlap with the absorption spectrum in the absorption band on the longest wavelength (low energy) side of the guest material. Therefore, it is usually difficult to overlap the fluorescence spectrum of the host material with the absorption spectrum in the absorption band on the longest wavelength (low energy) side of the guest material and maximize the energy transfer from the singlet excited state of the host material.

[0185] Therefore, it is preferred that in a light-emitting element using a phosphorescent compound as a guest material, the light-emitting layer contains a third substance in addition to the phosphorescent compound and the host material (respectively regarded as the first substance and the second substance contained in the light-emitting layer), and the combination of the host material and the third substance is a combination that forms an exciplex. At this time, when the carriers (electrons and holes) recombine in the light-emitting layer, the host material and the third substance form an exciplex. Thus, in the light-emitting layer, the fluorescence spectrum of the host material and the fluorescence spectrum of the third substance are converted into the emission spectrum of the exciplex located on the side of the longer wavelength. In addition, by selecting the host material and the third substance in such a way that the portion of the emission spectrum of the exciplex overlapping the absorption spectrum of the guest material is large, the energy transfer from the singlet excited state can be maximized. In addition, with respect to the triplet excited state, it can also be considered that the energy transfer from the exciplex is generated, and the energy transfer from the host material is not generated. In one embodiment of the present invention using such a structure, the energy transfer efficiency can be improved by utilizing the energy transfer of the overlap of the emission spectrum of the exciplex and the absorption spectrum of the phosphorescent compound, so that a light-emitting element with high external quantum efficiency can be realized.

[0186] As the guest material, for example, a phosphorescent compound described later can be used. In addition, as the combination of the host material and the third substance, any combination that forms an exciplex is sufficient, but it is preferred to combine a compound that easily accepts electrons (electron-trapping compound) and a compound that easily accepts holes (hole-trapping compound). The compound of one embodiment of the present invention can be used as an electron-trapping compound.

[0187] Therefore, the light-emitting element of one embodiment of the present invention has a light-emitting layer including a phosphorescent compound that emits light in a wavelength range of red to green, the compound of one embodiment of the present invention, and a compound that easily accepts holes, between a pair of electrodes.

[0188] As a compound that easily accepts holes and can be used as a host material or a third substance, there are, for example, π-electron-rich heteroaromatic compounds (for example, carbazole derivatives or indole derivatives) or aromatic amine compounds.

[0189] Specific examples thereof include N-(1,1'-biphenyl-4-yl)-N-[4-(9-phenyl-9H-carbazole-3-yl)phenyl]-9,9-dimethyl-9H-fluoren-2-amine (abbreviation: PCBBiF), 4-phenyl-4'-(9-phenyl-9H-carbazole-3-yl)triphenylamine (abbreviation: PCBA1BP), 4,4'-di(1-naphthyl)-4"-(9-phenyl-9H-carbazole-3-yl)triphenylamine (abbreviation: PCBNBB), 3-[N-(1-naphthyl)-N-(9-phenylcarbazole-3-yl)amino]-9-phenylcarbazole (abbreviation: PCzPCN1), 4,4',4"-tris[N-(1-naphthyl)-N-phenylamino] Triphenylamine (abbreviation: 1'-TNATA), 2,7-bis[N-(4-diphenylaminophenyl)-N-phenylamino]-spiro-9,9'-difluorene (abbreviation: DPA2SF), N,N'-bis(9-phenylcarbazole-3-yl)-N,N'-diphenylbenzene-1,3-diamine (abbreviation: PCA2B), N-(9,9-dimethyl-2-diphenylamino-9H-fluorene-7-yl)diphenylamine (abbreviation: DPNF), N,N',N"-triphenyl-N,N',N"-tri(9-phenylcarbazole-3-yl)benzene-1,3,5-triamine (abbreviation: PCA3B), 2-[N-(9-phenylcarbazole-3-yl)-N-phenylamino]spiro-9,9'- difluorene (abbreviation: PCASF), 2-[N-(4-diphenylaminophenyl)-N-phenylamino]spiro-9,9'-difluorene (abbreviation: DPASF), N,N'-bis[4-(carbazol-9-yl)phenyl]-N,N'-diphenyl-9,9-dimethylfluorene-2,7-diamine (abbreviation: YGA2F), N,N'-bis(3-methylphenyl)-N,N'-diphenyl-[1,1'-biphenyl]-4,4'-diamine (abbreviation: TPD), 4,4'-bis[N-(4-diphenylaminophenyl)-N-phenylamino]biphenyl (abbreviation: DPAB), N-(9,9-dimethyl-9H-fluoren-2-yl)-N-{9,9-dimethyl-2-[N' -phenyl-N'-(9,9-dimethyl-9H-fluoren-2-yl)amino]-9H-fluoren-7-yl}-phenylamine (abbreviation: DFLADFL), 3-[N-(9-phenylcarbazole-3-yl)-N-phenylamino]-9-phenylcarbazole (abbreviation: PCzPCA1), 3,6-bis[N-(9-phenylcarbazole-3-yl)-N-phenylamino]-9-phenylcarbazole (abbreviation: PCzPCA2), 3-[N-(4-diphenylaminophenyl)-N-phenylamino]-9-phenylcarbazole (abbreviation: PCzDPA1), 3,6-bis[N-(4-diphenylaminophenyl)-N-phenylamino]-9-phenylcarbazole (abbreviation: PCzDPA2), 4,4'-bis(N-{4-[N'-(3-methylphenyl)-N'-phenylamino]phenyl}-N-phenylamino)biphenyl (abbreviation: DNTPD), 3,6-bis[N-(4-diphenylaminophenyl)-N-(1-naphthyl)amino]-9-phenylcarbazole (abbreviation: PCzTPN2), etc.

[0190] In addition, 4,4'-bis[N-(1-naphthyl)-N-phenylamino]biphenyl (abbreviation: NPB or a-NPD), 4,4',4"-tris(N,N-diphenylamino)triphenylamine (abbreviation: TDATA), 4,4',4"-tris[N-(3-methylphenyl)-N-phenylamino]triphenylamine (abbreviation: MTDATA), 4,4'-bis[N-(spiro-9,9'-difluoren-2-yl)-N-phenylamino]biphenyl (abbreviation: BSPB), 4,4',4"-tris(N-carbazolyl)triphenylamine (abbreviation: TCTA), 4-phenyl-4'-(9-phenylfluoren-9-yl)triphenylamine (abbreviation: BPAFLP), 4,4'-bis[N-(9,9-dimethylfluoren-2-yl)-N-phenylamino]biphenyl (abbreviation: DFLDPBi ) or aromatic amine compounds such as 4,4'-di(N-carbazolyl)biphenyl (abbreviation: CBP), 9-[4-(10-phenyl-9-anthracenyl)phenyl]-9H-carbazole (abbreviation: CzPA), 9-phenyl-3-[4-(10-phenyl-9-anthracenyl)phenyl]-9H-carbazole (abbreviation: PCzPA) and other carbazole derivatives. In addition, there can be mentioned polymer compounds such as poly(N-vinylcarbazole) (abbreviation: PVK), poly(4-vinyltriphenylamine) (abbreviation: PVTPA), poly[N-(4-{N'-[4-(4-diphenylamino)phenyl]phenyl-N'-phenylamino}phenyl)methacrylamide] (abbreviation: PTPDMA), poly[N,N'-bis(4-butylphenyl)-N,N'-bis(phenyl)benzidine] (abbreviation: Poly-TPD).

[0191] As a compound that easily accepts electrons and can be used as a main material or a third substance, in addition to the compound of one embodiment of the present invention, π-electron-deficient heteroaromatic compounds such as nitrogen-containing heteroaromatic compounds, metal complexes having a quinoline skeleton or a benzoquinoline skeleton, and metal complexes having an oxazolyl ligand or a thiazole ligand can also be used.

[0192] Specifically, bis(10-hydroxybenzo[h]quinolinolato)beryllium (abbreviated as BeBq 2 ), bis(2-methyl-8-hydroxyquinoline)(4-phenylphenol)aluminum (abbreviation: BAlq), bis(8-hydroxyquinoline)zinc(II) (abbreviation: Znq), bis[2-(2-hydroxyphenyl)benzoxazole]zinc (abbreviation: Zn(BOX) 2), bis[2-(2-hydroxyphenyl)benzothiazole]zinc (abbreviated as: Zn(BTZ) 2 ) and other metal complexes; 2-(4-biphenyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole (abbreviated as: PBD), 3-(4-biphenyl)-4-phenyl-5-(4-tert-butylphenyl)-1,2,4-triazole (abbreviated as: TAZ), 1,3-bis[5-(p-tert-butylphenyl)-1,3,4-oxadiazole-2-yl]benzene (abbreviated as: OXD-7), 9-[4-(5-phenyl-1,3,4-oxadiazole-2-yl)phenyl]-9H-carbazole (abbreviated as: CO11), 2,2',2"-(1,3,5-benzenetriyl)tris(1-phenyl-1H-benzimidazole) (abbreviated as: TPBI), 2-[3-(dibenzothiophene-4-yl)-1,3,4-oxadiazole-2-yl]benzene (abbreviated as: OXD-7), 9-[4-(5-phenyl-1,3,4-oxadiazole-2-yl)phenyl]-9H-carbazole (abbreviated as: CO11), 2,2',2"-(1,3,5-benzenetriyl)tris(1-phenyl-1H-benzimidazole) (abbreviated as: TPBI), )phenyl]-1-phenyl-1H-benzimidazole (abbreviated as mDBTBIm-II), etc.; 2-[3-(dibenzothiophene-4-yl)phenyl]dibenzo[f,h]quinoxaline (abbreviated as 2mDBTPDBq-II), 2-[3'-(dibenzothiophene-4-yl)biphenyl-3-yl]dibenzo[f,h]quinoxaline (abbreviated as 2mDBTBPDBq-II), 2-[4-(3,6-diphenyl-9H-carbazole-9-yl)phenyl]dibenzo[f,h]quinoxaline (abbreviated as 2CzPDBq-III), 7-[3-(dibenzothiophene-4-yl)phenyl]dibenzo[f,h]quinoxaline (abbreviated as 2CzPDBq-III), 7-[3-(dibenzothiophene-4-yl)phenyl]dibenzo[f,h]quinoxaline (abbreviated as 2CzPDBq-III), 2-[3'-(dibenzothiophene-4-yl)biphenyl-3-yl ... h]quinoxaline (abbreviation: 7mDBTPDBq-II), 6-[3-(dibenzothiophen-4-yl)phenyl]dibenzo[f,h]quinoxaline (abbreviation: 6mDBTPDBq-II), and 2-[3'-(9H-carbazol-9-yl)biphenyl-3-yl]dibenzo[f,h]quinoxaline (abbreviation: 2mCzBPDBq); heterocyclic compounds having a quinoxaline skeleton or a dibenzoquinoxaline skeleton, such as 4,6-bis[3-(phenanthrene-9-yl)phenyl]pyrimidine (abbreviation: 4,6mPnP2Pm), 4,6-bis[3-(9H-carbazol-9-yl)phenyl]pyrimidine (abbreviation: 4,6mCzP2Pm), 4,6-bis[3-(4-dibenzothiophene- )phenyl]pyrimidine (abbreviation: 4,6mDBTP2Pm-II) and other heterocyclic compounds having a diazine skeleton (pyrimidine skeleton or pyrazine skeleton); 3,5-bis[3-(9H-carbazol-9-yl)phenyl]pyridine (abbreviation: 3,5DCzPPy), 1,3,5-tris[3-(3-pyridyl)phenyl]benzene (abbreviation: TmPyPB), 3,3',5,5'-tetrakis[(m-pyridyl)-phenyl-3-yl]biphenyl (abbreviation: BP4mPy) and other heterocyclic compounds having a pyridine skeleton. Among them, heterocyclic compounds having a quinoxaline skeleton or a dibenzoquinoxaline skeleton, heterocyclic compounds having a diazine skeleton, and heterocyclic compounds having a pyridine skeleton are preferred because they have high reliability.

[0193] In addition, tris(8-hydroxyquinoline)aluminum (abbreviation: Alq), tris(4-methyl-8-hydroxyquinoline)aluminum (abbreviation: Almq 3 ) and other metal complexes having a quinoline skeleton or a benzoquinoline skeleton; heteroaromatic compounds such as bathophenanthroline (abbreviation: BPhen), bathocuproin (abbreviation: BCP), 3-(4-tert-butylphenyl)-4-(4-ethylphenyl)-5-(4-biphenyl)-1,2,4-triazole (abbreviation: p-EtTAZ), and 4,4'-bis(5-methylbenzoxazol-2-yl)stilbene (abbreviation: BzOs). In addition, polymer compounds such as poly(2,5-pyridinediyl) (abbreviation: PPy), poly[(9,9-dihexylfluorene-2,7-diyl)-co-(pyridine-3,5-diyl)] (abbreviation: PF-Py), and poly[(9,9-dioctylfluorene-2,7-diyl)-co-(2,2'-bipyridine-6,6'-diyl)] (abbreviation: PF-BPy) can also be cited.

[0194] The materials that can be used as the main material and the third substance are not limited to these, as long as they are a combination that can form an excited complex, and the emission spectrum of the excited complex overlaps with the absorption spectrum of the guest material, and the peak of the emission spectrum of the excited complex is located on the longer wavelength side than the peak of the absorption spectrum of the guest material.

[0195] When a compound that easily accepts electrons and a compound that easily accepts holes are used as the host material and the third substance, the carrier balance can be adjusted by adjusting their mixing ratio. Specifically, the ratio of the host material to the third substance is preferably 1:9 to 9:1.

[0196] In addition, an exciplex can also be formed at the interface between the two layers. For example, by stacking a layer containing a compound that easily accepts electrons and a layer containing a compound that easily accepts holes, an exciplex is formed near the interface. The two layers can also be used as a light-emitting layer in a light-emitting element of one embodiment of the present invention. In this case, a phosphorescent compound is added near the interface. The phosphorescent compound is added to one or both layers of the two layers.

[0197] <<Objective Materials>>

[0198] An example of a fluorescent compound that can be used for the light-emitting layer 303 is given. For example, as a material emitting blue light, N,N'-bis(3-methylphenyl)-N,N'-bis[3-(9-phenyl-9H-fluorene-9-yl)phenyl]pyrene-1,6-diamine (abbreviated as: 1,6mMemFLPAPrn), N,N'-bis(dibenzofuran-4-yl)-N,N'-diphenylpyrene-1,6-diamine (abbreviated as: 1,6FrAPrn-II), N,N'-bis(dibenzofuran-4-yl)-N,N'-diphenylpyrene-1,6-diamine (abbreviated as: 1,6FrAPrn-II), -Bis[4-(9H-carbazole-9-yl)phenyl]-N,N'-diphenylstilbene-4,4'-diamine (abbreviation: YGA2S), 4-(9H-carbazole-9-yl)-4'-(10-phenyl-9-anthracenyl)triphenylamine (abbreviation: YGAPA), 4-(10-phenyl-9-anthracenyl)-4'-(9-phenyl-9H-carbazole-3-yl)triphenylamine (abbreviation: PCBAPA), etc. In addition, as a material emitting green light, N-(9,10-diphenyl-2-anthracenyl)-N,9-diphenyl-9H-carbazole-3-amine (abbreviated as 2PCAPA), N-[9,10-bis(1,1'-biphenyl-2-yl)-2-anthracenyl]-N,9-diphenyl-9H-carbazole-3-amine (abbreviated as 2PCABPhA), N-(9,10-diphenyl-2-anthracenyl)-N,N',N'-triphenyl-1,4-phenylenediamine ( Abbreviation: 2DPAPA), N-[9,10-bis(1,1'-biphenyl-2-yl)-2-anthryl]-N,N',N'-triphenyl-1,4-phenylenediamine (abbreviation: 2DPABPhA), 9,10-bis(1,1'-biphenyl-2-yl)-N-[4-(9H-carbazole-9-yl)phenyl]-N-phenylanthracen-2-amine (abbreviation: 2YGABPhA), N,N,9-triphenylanthracen-9-amine (abbreviation: DPhAPhA), etc. As materials emitting yellow light, rubrene, 5,12-bis(1,1'-biphenyl-4-yl)-6,11-diphenyltetracene (abbreviation: BPT), etc. can be cited. In addition, as materials emitting red light, there can be mentioned N,N,N',N'-tetrakis(4-methylphenyl)tetracene-5,11-diamine (abbreviation: p-mPhTD), 7,14-diphenyl-N,N,N',N'-tetrakis(4-methylphenyl)acenaphtho[1,2-a]fluoranthene-3,10-diamine (abbreviation: p-mPhAFD), etc.

[0199] An example of a phosphorescent compound that can be used for the light-emitting layer 303 is given below. For example, a phosphorescent compound having a light emission peak at 440 nm to 520 nm can be given as follows: tris{2-[5-(2-methylphenyl)-4-(2,6-dimethylphenyl)-4H-1,2,4-triazol-3-yl-κN2]phenyl-κC}iridium(III) (abbreviated as: [Ir(mpptz-dmp)3 ]), tris(5-methyl-3,4-diphenyl-4H-1,2,4-triazolato)iridium(III) (abbreviated as: [Ir(Mptz) 3 ]), tris[4-(3-biphenyl)-5-isopropyl-3-phenyl-4H-1,2,4-triazole]iridium(III) (abbreviated as: [Ir(iPrptz-3b) 3 ]) and other organic metal iridium complexes with a 4H-triazole skeleton; tris[3-methyl-1-(2-methylphenyl)-5-phenyl-1H-1,2,4-triazole]iridium(III) (abbreviated as: [Ir(Mptz1-mp) 3 ]), tris(1-methyl-5-phenyl-3-propyl-1H-1,2,4-triazole)iridium(III) (abbreviated as: [Ir(Prptz1-Me) 3 ]) and other organometallic iridium complexes with a 1H-triazole skeleton; fac-tris[1-(2,6-diisopropylphenyl)-2-phenyl-1H-imidazole]iridium(III) (abbreviated as: [Ir(iPrpmi) 3 ]), tris[3-(2,6-dimethylphenyl)-7-methylimidazo[1,2-f]phenanthridinato]iridium(III) (abbreviated as: [Ir(dmpimpt-Me) 3 ]) and other organometallic iridium complexes with imidazole skeletons; and bis[2-(4',6'-difluorophenyl)pyridinium-N,C 2 '] iridium (III) tetrakis (1-pyrazolyl) borate (abbreviated as FIr6), bis [2-(4',6'-difluorophenyl) pyridinium-N,C 2 '] iridium (III) picolinate (abbreviated as FIrpic), bis{2-[3',5'-bis(trifluoromethyl)phenyl]pyridinium-N,C 2 '}Iridium (III) picolinate (abbreviated as: [Ir(CF 3 ppy) 2 (pic)]), bis[2-(4',6'-difluorophenyl)pyridinium-N,C 2 '] Iridium (III) acetylacetone (abbreviated as Fir (acac)) and other organometallic iridium complexes with phenylpyridine derivatives having electron withdrawing groups as ligands. Among the above-mentioned organometallic iridium complexes, the organometallic iridium complexes having a 4H-triazole skeleton have good reliability and luminous efficiency, so they are particularly preferred.

[0200] For example, phosphorescent compounds having a luminescence peak at 520 nm to 600 nm include: tris(4-methyl-6-phenylpyrimidinyl)iridium(III) (abbreviated as: [Ir(mppm) 3]), tri(4-tert-butyl-6-phenylpyrimidinyl)iridium(III) (abbreviated as: [Ir(tBuppm) 3 ]), (acetylacetonato)bis(6-methyl-4-phenylpyrimidinyl)iridium(III) (abbreviated as: [Ir(mppm) 2 (acac)]), (acetylacetonato)bis(6-tert-butyl-4-phenylpyrimidinyl)iridium(III) (abbreviated as: [Ir(tBuppm) 2 (acac)]), (acetylacetonato)bis[4-(2-norbornyl)-6-phenylpyrimidinyl]iridium(III) (endo- and exo-mixture) (abbreviated as: [Ir(nbppm) 2 (acac)]), (acetylacetonato)bis[5-methyl-6-(2-methylphenyl)-4-phenylpyrimidinyl]iridium(III) (abbreviated as: [Ir(mpmppm) 2 (acac)]), (acetylacetonato)bis(4,6-diphenylpyrimidinyl)iridium(III) (abbreviated as: [Ir(dppm) 2 (acac)]) and other organometallic iridium complexes with pyrimidine skeletons; (acetylacetonato)bis(3,5-dimethyl-2-phenylpyrazine)iridium(III) (abbreviated as: [Ir(mppr-Me) 2 (acac)]), (acetylacetonato)bis(5-isopropyl-3-methyl-2-phenylpyrazine)iridium(III) (abbreviated as: [Ir(mppr-iPr) 2 (acac)]) and other organic metal iridium complexes with pyrazine skeletons; tris(2-phenylpyridinium-N,C 2 ') Iridium (III) (abbreviated as: [Ir(ppy) 3 ]), bis(2-phenylpyridinium-N,C 2 ') Iridium(III) acetylacetonate (abbreviated as: [Ir(ppy) 2 (acac)]), bis(benzo[h]quinoline)acetylacetonate iridium(III) (abbreviated as: [Ir(bzq) 2 (acac)]), tris(benzo[h]quinoline)iridium(III) (abbreviated as: [Ir(bzq) 3 ]), tris(2-phenylquinoline-N,C 2 ']iridium (III) (abbreviated as: [Ir(pq) 3 ]), bis(2-phenylquinoline-N,C 2 ') Iridium(III) acetylacetonate (abbreviated as: [Ir(pq) 2 (acac)]) and other organometallic iridium complexes with a pyridine skeleton; and tris(acetylacetonato)(monophenanthroline)terbium(III) (abbreviated as: [Tb(acac) 3Among the above metal complexes, organic metal iridium complexes with a pyrimidine skeleton have excellent reliability and luminous efficiency, so they are particularly preferred.

[0201] For example, examples of phosphorescent compounds having a luminescence peak at 600 nm to 700 nm include (diisobutyrylmethane)bis[4,6-bis(3-methylphenyl)pyrimidinyl]iridium(III) (abbreviated as [Ir(5mdppm) 2 (dibm)]), bis[4,6-bis(3-methylphenyl)pyrimidinyl](dipivaloylmethano)iridium(III) (abbreviated as: [Ir(5mdppm) 2 (dpm)]), bis[4,6-di(naphthalene-1-yl)pyrimidinyl](dipivaloylmethano)iridium(III) (abbreviated as: [Ir(d1npm) 2 (dpm)]) and other organometallic iridium complexes with pyrimidine skeletons; (acetylacetonato)bis(2,3,5-triphenylpyrazine)iridium(III) (abbreviated as: [Ir(tppr) 2 (acac)]), bis(2,3,5-triphenylpyrazine)(dipivaloylmethano)iridium(III) (abbreviated as [Ir(tppr) 2 (dpm)]), (acetylacetonato)bis[2,3-bis(4-fluorophenyl)quinoxaline]iridium(III) (abbreviated as: [Ir(Fdpq) 2 (acac)]) and other organometallic iridium complexes with pyrazine skeletons; tris(1-phenylisoquinoline-N,C 2 ') Iridium (III) (abbreviated as: [Ir(piq) 3 ]), bis(1-phenylisoquinoline-N,C 2 ') Iridium(III) acetylacetonate (abbreviated as: [Ir(piq) 2 (acac)]) and other organometallic iridium complexes with a pyridine skeleton; platinum complexes such as 2,3,7,8,12,13,17,18-octaethyl-21H,23H-porphyrin platinum (II) (abbreviated as PtOEP); and tris(1,3-diphenyl-1,3-propanedione)(monophenanthroline)europium(III) (abbreviated as [Eu(DBM) 3 (Phen)]), tris[1-(2-thenoyl)-3,3,3-trifluoroacetone](monophenanthroline)europium(III) (abbreviated as: [Eu(TTA) 3Among the above metal complexes, organic metal iridium complexes with a pyrimidine skeleton have excellent reliability and luminous efficiency, so they are particularly preferred. In addition, organic metal iridium complexes with a pyrazine skeleton can provide red luminescence with good chromaticity.

[0202] A polymer compound may also be used as the light-emitting layer 303. For example, as a material emitting blue light, poly(9,9-dioctylfluorene-2,7-diyl) (abbreviated as POF), poly[(9,9-dioctylfluorene-2,7-diyl)-co-(2,5-dimethoxybenzene-1,4-diyl)] (abbreviated as PF-DMOP), poly{(9,9-dioctylfluorene-2,7-diyl)-co-[N,N'-di-(p-butylphenyl)-1,4-diaminobenzene]} (abbreviated as TAB-PFH), etc. may be cited. In addition, as materials that emit green light, there can be mentioned poly(p-phenylene vinylene) (abbreviation: PPV), poly[(9,9-dihexylfluorene-2,7-diyl)-alt-co-(benzo[2,1,3]thiadiazole-4,7-diyl)] (abbreviation: PFBT), poly[(9,9-dioctyl-2,7-divinylenefluorenylene)-alt-co-(2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylene) and the like. In addition, as materials emitting orange to red light, there can be mentioned poly[2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylene vinylene] (abbreviation: MEH-PPV), poly(3-butylthiophene-2,5-diyl), poly{[9,9-dihexyl-2,7-bis(1-cyanovinylene)fluorenyl]-alt-co-[2,5-bis(N,N'-diphenylamino)-1,4-phenylene]}, poly{[2-methoxy-5-(2-ethylhexyloxy)-1,4-bis(1-cyanovinylenephenylene)]-alt-co-[2,5-bis(N,N'-diphenylamino)-1,4-phenylene]} (abbreviation: CN-PPV-DPD), etc.

[0203] <Hole Transport Layer>

[0204] The hole transport layer 302 is a layer containing a substance having a high hole transport property.

[0205] As a substance with high hole transport properties, any substance with hole transport properties higher than electron transport properties may be used, and a substance with a hole mobility of 10 -6 cm 2 / Vs or above.

[0206] For the hole-transport layer 302 , for example, the compound that easily accepts holes shown as a substance that can be used for the light-emitting layer 303 can be used.

[0207] In addition, aromatic hydrocarbon compounds such as 2-tert-butyl-9,10-di(2-naphthyl)anthracene (abbreviation: t-BuDNA), 9,10-di(2-naphthyl)anthracene (abbreviation: DNA), and 9,10-diphenylanthracene (abbreviation: DPAnth) can be used.

[0208] <Electron Transport Layer>

[0209] The electron transport layer 304 is a layer containing a substance having a high electron transport property.

[0210] As the substance with high electron transport property, any organic compound with higher electron transport property than hole transport property can be used, and in particular, an organic compound with electron mobility of 10 -6 cm 2 / Vs or above.

[0211] For the electron-transport layer 304 , for example, the compound that easily accepts electrons shown as the substance that can be used for the light-emitting layer 303 can be used.

[0212] <Hole Injection Layer>

[0213] The hole injection layer 301 is a layer containing a substance with high hole injectability.

[0214] As a substance having a high hole injecting property, for example, metal oxides such as molybdenum oxide, titanium oxide, vanadium oxide, rhenium oxide, ruthenium oxide, chromium oxide, zirconium oxide, hafnium oxide, tantalum oxide, silver oxide, tungsten oxide, and manganese oxide can be used.

[0215] In addition, phthalocyanine (abbreviated as: H 2 Phthalocyanine compounds such as copper phthalocyanine (II) (abbreviated as CuPc).

[0216] In addition, aromatic amine compounds such as low molecular weight organic compounds such as TDATA, MTDATA, DPAB, DNTPD, 1,3,5-tris[N-(4-diphenylaminophenyl)-N-phenylamino]benzene (abbreviation: DPA3B), PCzPCA1, PCzPCA2, PCzPCN1, etc. can be used.

[0217] Alternatively, a polymer compound such as PVK, PVTPA, PTPDMA, or Poly-TPD, or a polymer compound to which an acid is added such as poly(3,4-ethylenedioxythiophene) / poly(styrenesulfonic acid) (PEDOT / PSS) or polyaniline / poly(styrenesulfonic acid) (PAni / PSS) may be used.

[0218] In addition, the hole injection layer 301 can also be used as a charge generation region. When the hole injection layer 301 in contact with the anode is used as the charge generation region, various conductive materials can be used for the anode regardless of the work function. The material of the charge generation region will be described later.

[0219] <Electron Injection Layer>

[0220] The electron injection layer 305 is a layer containing a substance having a high electron injecting property.

[0221] As a substance with high electron injection property, for example, alkali metals, alkaline earth metals, rare earth metals or their compounds (oxides, carbonates, halides, etc.) such as lithium, cesium, calcium, lithium oxide, lithium carbonate, cesium carbonate, lithium fluoride, cesium fluoride, calcium fluoride or erbium fluoride can be used. In addition, electron salts can also be used. As electron salts, substances that add electrons to oxides containing calcium and aluminum at high concentrations can be cited.

[0222] Alternatively, the electron injection layer 305 may be used as a charge generation region. When the electron injection layer 305 in contact with the cathode is used as a charge generation region, various conductive materials may be used for the cathode regardless of the work function. The materials for the charge generation region will be described later.

[0223] <Charge Generation Region>

[0224] The charge generation region may have a structure in which an electron acceptor (acceptor) is added to an organic compound having a high hole transport property, or a structure in which an electron donor (donor) is added to an organic compound having a high electron transport property. These two structures may be stacked.

[0225] Examples of the organic compound having a high hole-transporting property include the materials described above that can be used in the hole-transporting layer, and examples of the organic compound having a high electron-transporting property include the materials described above that can be used in the electron-transporting layer.

[0226] As electron acceptors, 7,7,8,8-tetracyano-2,3,5,6-tetrafluoroquinodimethane (abbreviated as: F4-TCNQ), chloranil, etc. can be cited. In addition, transition metal oxides can be cited. In addition, oxides of metals belonging to Groups 4 to 8 of the periodic table can be cited. Specifically, vanadium oxide, niobium oxide, tantalum oxide, chromium oxide, molybdenum oxide, tungsten oxide, manganese oxide and rhenium oxide are preferably used because they have high electron acceptance. Molybdenum oxide is particularly preferably used because it is stable in the atmosphere, has low hygroscopicity, and is easy to handle.

[0227] As the electron donor, alkali metals, alkaline earth metals, rare earth metals, metals belonging to Group 2 or Group 13 in the periodic table, and their oxides and carbonates can be used. Specifically, lithium, cesium, magnesium, calcium, ytterbium, indium, lithium oxide, cesium carbonate, etc. are preferably used. In addition, organic compounds such as tetrathianaphthacene can also be used as electron donors.

[0228] The layers constituting the EL layer 203 and the intermediate layer 207 can be formed by a method such as an evaporation method (including a vacuum evaporation method), a transfer method, a printing method, an inkjet method, or a coating method.

[0229] This embodiment mode can be freely combined with other embodiment modes.

[0230] Implementation 3

[0231] In this embodiment, refer to Figure 2A and Figure 2B as well as FIG. 3A to FIG. 3C A light-emitting device according to one embodiment of the present invention will be described.

[0232] In this embodiment, a light-emitting device including a light-emitting element which is one embodiment of the present invention is exemplified. Since the light-emitting element has a long life, a light-emitting device with high reliability can be realized.

[0233] Note that one embodiment of the present invention is not limited to this and may not include a light-emitting element of one embodiment of the present invention or a compound of one embodiment of the present invention.

[0234] Figure 2A is a plan view showing a light emitting device according to one embodiment of the present invention, Figure 2B It is along Figure 2A Cross-sectional view taken along the chain link line AB.

[0235] The light-emitting device of this embodiment includes a light-emitting element 403 in a space 415 surrounded by a supporting substrate 401, a sealing substrate 405, and a sealant 407. The light-emitting element 403 is an organic EL element having a bottom emission structure, and specifically, a first electrode 421 that transmits visible light is provided on the supporting substrate 401, an EL layer 423 is provided on the first electrode 421, and a second electrode 425 that reflects visible light is provided on the EL layer 423. The EL layer 423 contains the compound of one embodiment of the present invention described in Embodiment 1.

[0236] The first terminal 409a is electrically connected to the auxiliary wiring 417 and the first electrode 421. An insulating layer 419 is provided in a region on the first electrode 421 that overlaps with the auxiliary wiring 417. The first terminal 409a is electrically insulated from the second electrode 425 by the insulating layer 419. The second terminal 409b is electrically connected to the second electrode 425. In addition, in this embodiment, although the structure in which the first electrode 421 is formed on the auxiliary wiring 417 is shown, the auxiliary wiring 417 may be formed on the first electrode 421.

[0237] Preferably, a light extraction structure 411a is provided at the interface between the support substrate 401 and the atmosphere. By providing the light extraction structure 411a at the interface between the atmosphere and the support substrate 401, light that cannot be extracted into the atmosphere due to total reflection can be reduced, thereby improving the light extraction efficiency of the light emitting device.

[0238] In addition, it is preferable to provide a light extraction structure 411b at the interface between the light emitting element 403 and the supporting substrate 401. When the light extraction structure 411b has concavoconvexity, it is preferable to provide a planarization layer 413 between the light extraction structure 411b and the first electrode 421. Thus, the first electrode 421 can be formed as a flat film, and the leakage current generated in the EL layer 423 due to the concavoconvexity of the first electrode 421 can be suppressed. In addition, because the light extraction structure 411b is provided at the interface between the planarization layer 413 and the supporting substrate 401, the light that cannot be extracted into the atmosphere due to the influence of total reflection can be reduced, thereby improving the light extraction efficiency of the light emitting device.

[0239] As a material of the light extraction structure 411a and the light extraction structure 411b, for example, a resin can be used. In addition, as the light extraction structure 411a and the light extraction structure 411b, a hemispherical lens, a microlens array, a film having a concave-convex structure, or a light diffusion film can also be used. For example, the light extraction structure 411a and the light extraction structure 411b can be formed by bonding the lens or the film to the support substrate 401 using an adhesive having a refractive index equal to that of the support substrate 401, the lens, or the film.

[0240] The surface of the planarization layer 413 in contact with the first electrode 421 is flatter than the surface of the planarization layer 413 in contact with the light extraction structure 411b. As a material of the planarization layer 413, glass, liquid, resin, or the like having light transmittance and a high refractive index can be used.

[0241] Figure 3A is a plan view showing a light emitting device according to one embodiment of the present invention, Figure 3B It is along Figure 3A The cross-sectional view of the chain link CD in the figure, Figure 3C It is a cross-sectional view showing a modified example of the light emitting portion.

[0242] The active matrix light-emitting device according to this embodiment has a light-emitting portion 551 (whose cross section is Figure 3B The light emitting portion 551a or Figure 3C The light emitting portion 551b, the driving circuit portion 552 (gate side driving circuit portion), the driving circuit portion 553 (source side driving circuit portion), and the sealant 507. The light emitting portion 551, the driving circuit portion 552, and the driving circuit portion 553 are sealed in a space 515 formed by the supporting substrate 501, the sealing substrate 505, and the sealant 507.

[0243] The light-emitting device of one embodiment of the present invention may adopt any of a separate coating method, a color filter method, and a color conversion method. Figure 3B The light emitting portion 551a manufactured by using a color filter method is shown. Figure 3C The light emitting portion 551b manufactured by the separate coating method is shown.

[0244] The light emitting portion 551a and the light emitting portion 551b each include a plurality of light emitting units, each of which includes a switching transistor 541a, a current control transistor 541b, and a second electrode 525 electrically connected to a wiring (source electrode or drain electrode) of the transistor 541b.

[0245] The light-emitting element 503 included in the light-emitting portion 551a has a bottom emission structure and includes a first electrode 521 that transmits visible light, an EL layer 523, and a second electrode 525. In addition, a partition wall 519 is formed so as to cover an end portion of the first electrode 521.

[0246] The light-emitting element 504 included in the light-emitting portion 551b has a top emission structure and is composed of a first electrode 561, an EL layer 563, and a second electrode 565 that transmits visible light. In addition, a partition wall 519 is formed to cover the end of the first electrode 561. In the EL layer 563, at least a layer (for example, a light-emitting layer) composed of a material different according to the light-emitting element is applied separately.

[0247] The support substrate 501 is provided with a lead 517 for connecting an external input terminal, which transmits a signal (video signal, clock signal, start signal, reset signal, etc.) or a potential from the outside to the drive circuit portion 552 and the drive circuit portion 553. Here, an example in which an FPC (Flexible Printed Circuit) 509 is provided as an external input terminal is shown.

[0248] The driving circuit portion 552 and the driving circuit portion 553 include a plurality of transistors. Figure 3B 2 shows two transistors (a transistor 542 and a transistor 543) among the transistors included in the driving circuit portion 552.

[0249] In order to prevent an increase in the number of processes, the lead 517 and the electrodes or wiring used for the light-emitting portion or the driving circuit portion are preferably manufactured using the same material and the same process. In this embodiment, an example is shown in which the lead 517 and the source electrode and the drain electrode of the transistor included in the light-emitting portion 551 and the driving circuit portion 552 are manufactured using the same material and the same process.

[0250] exist Figure 3B In the embodiment, the sealant 507 is in contact with the first insulating layer 511 on the lead 517. Sometimes, the sealant 507 has low adhesion to the metal. Therefore, the sealant 507 is preferably in contact with the inorganic insulating film provided on the lead 517. By adopting this structure, a light-emitting device with high adhesion and reliability can be realized. Examples of the inorganic insulating film include oxide films of metals or semiconductors, nitride films of metals or semiconductors, and oxynitride films of metals or semiconductors. Specifically, silicon oxide films, silicon nitride films, silicon oxynitride films, silicon nitride oxide films, aluminum oxide films, titanium oxide films, etc. can be cited.

[0251] The first insulating layer 511 has an effect of suppressing diffusion of impurities into a semiconductor constituting the transistor. In order to reduce surface irregularities caused by the transistor, an insulating film having a planarizing function is preferably selected as the second insulating layer 513 .

[0252] There is no particular restriction on the structure and material of the transistor used in the light-emitting device of one embodiment of the present invention, and both top-gate transistors and bottom-gate transistors such as inverted staggered transistors can be used. In addition, both channel-etched transistors and channel-protected transistors can be used. In addition, both n-channel transistors and p-channel transistors can be used.

[0253] The semiconductor layer can be formed using silicon, an oxide semiconductor, or an organic semiconductor. It is preferred to use an oxide semiconductor of an In-Ga-Zn-based metal oxide as the semiconductor layer to form a transistor with low off-state current, which can suppress leakage current when the light-emitting element is in the off state.

[0254] exist Figure 3B In the sealing substrate 505 shown in FIG. 1 , a color filter 533 as a coloring layer is provided at a position overlapping with (the light-emitting region of) the light-emitting element 503, and a black matrix 531 is provided at a position overlapping with the partition wall 519. In addition, a protective layer 535 covering the color filter 533 and the black matrix 531 is provided. Figure 3C The sealing substrate 505 is shown with a desiccant 506 disposed thereon.

[0255] This embodiment mode can be combined with other embodiment modes as appropriate.

[0256] Implementation 4

[0257] In this embodiment, using FIG. 4A to FIG. 4E as well as Fig. 6A and Figure 6B An example of an electronic device and a lighting device according to one embodiment of the present invention will be described.

[0258] The electronic device in this embodiment has a light-emitting device of one embodiment of the present invention in its display portion. In addition, the lighting device in this embodiment has a light-emitting device of one embodiment of the present invention in its light-emitting portion (illumination portion). By adopting the light-emitting device of one embodiment of the present invention, a highly reliable electronic device and lighting device can be realized.

[0259] Note that one embodiment of the present invention is not limited to this and may not include the light-emitting device of one embodiment of the present invention.

[0260] Electronic devices using light-emitting devices include, for example, television devices (also called televisions or television receivers), displays for computers, etc., digital cameras, digital video cameras, digital photo frames, mobile phones (also called mobile phones, mobile phone devices), portable game consoles, portable information terminals, sound reproduction devices, large game consoles such as pinball machines, etc. FIG. 4A to FIG. 4E as well as Fig. 6A and Figure 6B Specific examples of these electronic devices and lighting devices are shown.

[0261] The electronic device and lighting device of one embodiment of the present invention may also be flexible. The electronic device and lighting device may also be assembled along the curved surface of the inner wall or outer wall of a house or building, or the interior or exterior decoration of a car.

[0262] Figure 4A An example of a television set is shown. In a television set 7100, a display portion 7102 is incorporated in a housing 7101. An image can be displayed on the display portion 7102. A light-emitting device according to one embodiment of the present invention can be used for the display portion 7102. Here, a structure in which the housing 7101 is supported by a stand 7103 is shown.

[0263] The television set 7100 can be operated by using an operation switch provided in the housing 7101 or a remote control unit 7111 provided separately. Channels and volume can be operated by using operation keys provided in the remote control unit 7111, and images displayed on the display portion 7102 can be operated. Alternatively, the remote control unit 7111 may be provided with a display unit for displaying data output from the remote control unit 7111.

[0264] In addition, the television device 7100 includes a receiver and a modem. The receiver can be used to receive general television broadcasts. Furthermore, the modem can be connected to a wired or wireless communication network to perform one-way (from a sender to a receiver) or two-way (between a sender and a receiver or between receivers, etc.) information communication.

[0265] Figure 4B 7200 includes a main body 7201, a housing 7202, a display portion 7203, a keyboard 7204, an external connection port 7205, a pointing device 7206, and the like. The computer is manufactured by using the light-emitting device of one embodiment of the present invention for the display portion 7203 thereof.

[0266] Figure 4C 7300 is an example of a portable game console. The portable game console 7300 is composed of two housings, a housing 7301a and a housing 7301b, which are connected to each other so as to be openable and closable via a connection portion 7302. The housing 7301a is assembled with a display portion 7303a, and the housing 7301b is assembled with a display portion 7303b. Figure 4C The portable game console shown also includes a speaker section 7304, a recording medium insertion section 7305, an operation key 7306, a connection terminal 7307, a sensor 7308 (including a function of measuring the following factors: force, displacement, position, speed, acceleration, angular velocity, number of rotations, distance, light, liquid, magnetism, temperature, chemical substance, sound, time, hardness, electric field, current, voltage, electricity, radiation, flow, humidity, slope, vibration, smell or infrared), an LED lamp, a microphone, etc. Of course, the structure of the portable game console is not limited to the above structure, as long as a light-emitting device of one embodiment of the present invention is used in one or both of the display section 7303a and the display section 7303b, and a structure with other auxiliary devices appropriately provided can be adopted. Figure 4C The portable game machine shown has the following functions: reading out programs or data stored in a recording medium and displaying them on a display unit; and sharing information by wirelessly communicating with other portable game machines. Figure 4C The functions of the portable game machine shown are not limited to these, but the portable game machine may have various functions.

[0267] Figure 4D An example of a mobile phone is shown. The mobile phone 7400 includes an operation button 7403, an external connection port 7404, a speaker 7405, a microphone 7406, and the like in addition to a display portion 7402 incorporated in a housing 7401. The mobile phone 7400 is manufactured by using a light-emitting device according to one embodiment of the present invention in its display portion 7402.

[0268] exist Figure 4D In the illustrated mobile phone 7400, data can be input by touching the display portion 7402 with a finger or the like. Also, operations such as making a call or writing an e-mail can be performed by touching the display portion 7402 with a finger or the like.

[0269] The display portion 7402 mainly has three screen modes. The first mode is a display mode mainly used to display images. The second mode is an input mode mainly used to input information such as text. The third mode is a display and input mode that combines the display mode and the input mode.

[0270] For example, when making a phone call or writing an e-mail, the display portion 7402 can be set to a text input mode mainly for text input, and the text displayed on the screen can be input.

[0271] In addition, by providing a detection device having a sensor for detecting inclination such as a gyro sensor and an acceleration sensor inside the mobile phone 7400, the orientation (portrait or landscape) of the mobile phone 7400 can be determined, thereby automatically switching the screen display of the display portion 7402.

[0272] The screen mode is switched by touching the display portion 7402 or operating the operation button 7403 of the housing 7401. The screen mode may be switched depending on the type of image displayed on the display portion 7402. For example, when the image signal displayed on the display portion is data of a dynamic image, the screen mode is switched to the display mode, and when the image signal displayed on the display portion is text data, the screen mode is switched to the input mode.

[0273] In addition, when it is detected by detecting a signal detected by the light sensor of the display portion 7402 in the input mode that there is no touch operation input to the display portion 7402 for a certain period of time, the screen mode may be controlled to switch from the input mode to the display mode.

[0274] The display portion 7402 can also be used as an image sensor. For example, by touching the display portion 7402 with a palm or a finger, palm prints, fingerprints, etc. can be photographed, thereby enabling identification. In addition, by using a backlight that emits near-infrared light or a sensing light source that emits near-infrared light for the display portion, finger veins, palm veins, etc. can also be photographed.

[0275] Figure 4EAn example of a foldable tablet terminal (opened state) is shown. Tablet terminal 7500 includes a housing 7501a, a housing 7501b, a display unit 7502a, and a display unit 7502b. Housing 7501a and housing 7501b are connected to each other by an axis 7503, and can be opened and closed with the axis 7503 as an axis. In addition, housing 7501a includes a power switch 7504, an operation key 7505, a speaker 7506, etc. In addition, tablet terminal 7500 is manufactured by using a light-emitting device of one embodiment of the present invention in one or both of its display unit 7502a and display unit 7502b.

[0276] At least a portion of the display portion 7502a and the display portion 7502b can be used as a touch screen area, and data can be input by pressing a displayed operation key. For example, the entire surface of the display portion 7502a can be displayed with keyboard buttons to use it as a touch screen, and the display portion 7502b can be used as a display screen.

[0277] An electronic device of one embodiment of the present invention may also have an input / output device (also referred to as a touch panel) and a secondary battery. In this case, the secondary battery is preferably charged by contactless power transmission. The input / output device has a display unit and an input unit, and a light-emitting device of one embodiment of the present invention may be used for the display unit, and an input device (also referred to as a touch sensor) having a detection element or the like may be used for the input unit.

[0278] Examples of secondary batteries include lithium ion batteries such as lithium polymer batteries (lithium ion polymer batteries) using a gel electrolyte, nickel hydrogen batteries, nickel cadmium batteries, organic radical batteries, lead storage batteries, air secondary batteries, nickel zinc batteries, and silver zinc batteries.

[0279] An electronic device according to one embodiment of the present invention may include a touch panel and an antenna. By receiving a signal through the antenna, an image or information may be displayed on a display unit. When the electronic device includes a secondary battery, the antenna may be used for contactless power transmission.

[0280] FIG. 5A to FIG. 5C A foldable key fob 310 is shown. Figure 5A The portable information terminal 310 is shown in an unfolded state. Figure 5B The portable information terminal 310 is shown in a state halfway between changing from one of the unfolded state and the folded state to the other state. Figure 5C The portable information terminal 310 is shown in a folded state. The portable information terminal 310 is easy to carry when folded, and has a large seamless display area when unfolded, so the display is easy to view.

[0281] The three housings 315 connected by the hinge 313 support the display panel 312. The portable information terminal 310 can be reversibly changed from the unfolded state to the folded state by folding between the two housings 315 using the hinge 313. The light emitting device (or display device) of one embodiment of the present invention can be used for the display panel 312. For example, a display device that can be bent with a curvature radius of 1 mm or more and 150 mm or less can be used.

[0282] Figure 5D and Figure 5E A foldable key fob 320 is shown. Figure 5D The portable information terminal 320 is shown in a folded state so that the display unit 322 is located outside. Figure 5E The portable information terminal 320 is shown in a state where it is folded so that the display unit 322 is located inside. When the portable information terminal 320 is not in use, by folding so that the non-display unit 325 is located outside, it is possible to prevent the display unit 322 from being soiled or damaged. The light emitting device (or display device) of one embodiment of the present invention can be used for the display unit 322.

[0283] Fig. 5F It is a perspective view of the appearance of the portable information terminal 330. Figure 5G It is a top view of the portable information terminal 330 . Figure 5H It is a perspective view of the appearance of the portable information terminal 340.

[0284] The portable information terminals 330 and 340 have, for example, one or more functions selected from a telephone, an electronic notebook, an information reader, etc. Specifically, the portable information terminals 330 and 340 can be used as smartphones.

[0285] The portable information terminals 330 and 340 can display text or image information on multiple surfaces. For example, three operation buttons 339 can be displayed on one surface ( Fig. 5F , Figure 5H ). In addition, information 337 represented by a dotted rectangle may be displayed on another face ( Figure 5G , Figure 5H ). In addition, examples of information 337 include a display indicating that a notification, email, or phone call has been received from an SNS (Social Networking Services); the title of the email or the sender's name; the date; the time; the battery level; and the antenna reception strength. Alternatively, an operation button 339 or an icon may be displayed in place of information 337. Note that although Fig. 5F and Figure 5GAn example of displaying information 337 on the upper surface is shown, but one embodiment of the present invention is not limited to this. Figure 5H As shown in FIG. 3 , the information 337 may be displayed on the side.

[0286] The light emitting device (or display device) according to one embodiment of the present invention can be used for the display portion 333 included in the housing 335 of the portable information terminal 330 and the housing 336 of the portable information terminal 340 .

[0287] In addition, if Fig.5I As shown in FIG. 3 , information can be displayed on three or more surfaces, such as the portable information terminal 345 shown in FIG. Here, an example is shown in which information 355, information 356, and information 357 are displayed on different surfaces. The light emitting device (or display device) of one embodiment of the present invention can be used for the display unit 358 of the housing 351 of the portable information terminal 345.

[0288] Fig. 6A The indoor lighting device 7601, the roll-type lighting device 7602, the table lighting device 7603, and the planar lighting device 7604 shown are all examples of lighting devices using the light-emitting device of one embodiment of the present invention. The light-emitting device of one embodiment of the present invention can also be large-area, so it can be used as a lighting device for a large area. In addition, it is thin, so it can be installed on the wall.

[0289] Figure 6B The desktop lighting device shown includes a lighting unit 7701, a support 7703, a bracket 7705, and the like. In the lighting unit 7701, a light emitting device of one embodiment of the present invention is used. Thus, according to one embodiment of the present invention, a lighting device having a light emitting unit with a curved surface or a lighting device having a flexible lighting unit can be realized. Thus, by using a flexible light emitting device for the lighting device, not only the degree of freedom in the design of the lighting device is increased, but also, for example, the lighting device can be set in a place having a curved surface, such as a ceiling or a dashboard of a car. Note that the lighting device of one embodiment of the present invention may also have a housing or a cover.

[0290] This embodiment mode can be combined with other embodiment modes as appropriate.

[0291] Example 1

[0292] [Synthesis Example 1]

[0293] In this embodiment, a method for synthesizing 2-[3'-(benzo[b]naphtho[2,3-d]furan-8-yl)biphenyl-3-yl]dibenzo[f,h]quinoxaline (abbreviated as: 2mBnf(II)BPDBq) represented by the following structural formula (101) according to one embodiment of the present invention is described. In addition, a method for synthesizing 8-chlorobenzo[b]naphtho[2,3-d]furan represented by the following structural formula (201) according to one embodiment of the present invention is described.

[0294]

[0295] <Step 1: Synthesis of 3-(3-chloro-2-fluorophenyl)-2-naphthol>

[0296] (B-1) shows the synthesis scheme of step 1.

[0297]

[0298] 16g (70mmol) of 3-bromo-2-naphthol, 12g (70mmol) of 3-chloro-2-fluorophenylboric acid and 1.1g (3.5mol) of tri(o-tolyl)phosphine were placed in a 1000mL three-necked flask, and the flask was purged with nitrogen. 300mL of toluene, 60mL of ethanol and 90mL of potassium carbonate aqueous solution (2.0mol / L) were added to the mixture. The mixture was stirred while the flask was depressurized to degas the mixture, and the flask was purged with nitrogen after degassing. After 0.16g (0.70mmol) of palladium (II) acetate was added to the mixture, the mixture was stirred at a temperature of 80°C under a nitrogen stream for 3 hours. After stirring, the organic layer of the mixture was washed with water, and then the aqueous layer was extracted with ethyl acetate. The mixed extract solution and the organic layer were washed with saturated brine, and the organic layer was dried with magnesium sulfate. The obtained mixture was naturally filtered, and the obtained filtrate was concentrated to obtain 23 g of a brown liquid containing the target compound as a main component.

[0299] <Step 2: Synthesis of 8-chlorobenzo[b]naphtho[2,3-d]furan>

[0300] (B-2) shows the synthesis scheme of step 2.

[0301]

[0302] 23g of the brown liquid obtained by step 1, 300mL of N-methyl-2-pyrrolidone and 27g (0.20mol) of potassium carbonate are placed in a 500mL eggplant-shaped flask, and the mixture is stirred at a temperature of 150°C for 7 hours under atmosphere. After stirring, about 50mL of water and about 50mL of hydrochloric acid (1.0mol / L) are added to the obtained mixture. After adding about 100mL of ethyl acetate to the obtained solution, the water layer is extracted three times with ethyl acetate. The mixed extract and the organic layer are washed with saturated sodium bicarbonate aqueous solution and saturated brine, and then magnesium sulfate is added. The filtrate obtained by natural filtration of the mixture is concentrated to obtain 5.4g of the light brown solid of the target. The yield after two stages of step 1 and step 2 is 23%.

[0303] The following shows the obtained light brown solid 1 H NMR data.

[0304] 1 H NMR (CDCl 3 ,500MHz): δ=7.32(t,J=7.5Hz,1H),7.49-7.57(m,3H),7.96(dd,J1=8.25Hz,J2=1 .5Hz,1H),8.00(d,J=9.0Hz,1H),8.01(s,1H),8.04(d,J=9.0Hz,1H),8.42(s,1H)

[0305] Fig. 7A and Figure 7B Show 1 H NMR spectra. Figure 7B yes Fig. 7A An enlarged view of the range from 7.00 ppm to 9.00 ppm.

[0306] <Step 3: Synthesis of 2-(Benzo[b]naphtho[2,3-d]furan-8-yl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane>

[0307] (B-3) shows the synthesis scheme of step 3.

[0308]

[0309] 1.1 g (4.3 mmol) of 8-chlorobenzo[b]naphtho[2,3-d]furan, 1.1 g (4.3 mmol) of biboronic acid pinacol ester, 0.79 g (8.0 mmol) of potassium acetate and 179 mg (0.50 mmol) of di(1-adamantane)-n-butylphosphine were placed in a 200 mL three-necked flask, and the flask was purged with nitrogen. 25 mL of 1,4-dioxane was added to the mixture. The mixture was stirred while the pressure in the flask was reduced to degas the mixture, and after degassing, the flask was purged with nitrogen. 81 mg (0.11 mmol) of [1,1'-bis(diphenylphosphino)ferrocene]dichloropalladium(II) dichloromethane adduct was added to the mixture, and then the mixture was refluxed at 180° C. for 5 hours under a nitrogen stream. After refluxing, the progress of the reaction was confirmed by thin layer silica gel column chromatography (developing solvent: hexane:ethyl acetate=10:1), but no spot of the starting material was confirmed, so the next reaction was carried out.

[0310] <Step 4: Synthesis of 2mBnf(II)BPDBq>

[0311] (B-4) shows the synthesis scheme of step 4.

[0312]

[0313] After the reaction of step 3 was completed, the reaction of step 4 was continued in the same container without post-treatment (work up). 1.9 g (4.3 mmol) of 2-(3'-bromobiphenyl-3-yl)dibenzo[f,h]quinoxaline and 3.3 g (10 mmol) of cesium carbonate were added to the reaction mixture containing 2-(benzo[b]naphtho[2,3-d]furan-8-yl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane produced in step 3. After 0.12 mg (0.10 mol) of tetrakis(triphenylphosphine)palladium(0) was added to the mixture, the mixture was stirred at 150° C. for 5 and a half hours under a nitrogen stream. About 100 mL of toluene was added to the obtained mixture, and the mixture was refluxed. After refluxing, undissolved solids were collected by suction filtration, and the obtained solids were washed with water and ethanol in this order to obtain 1.4 g of a light brown solid at a crude yield of 55%.

[0314] 1.4 g of the obtained light brown solid was purified by sublimation using a gradient sublimation method. In the sublimation purification, the light brown solid was heated at 330° C. for 15 hours under the conditions of a pressure of 2.5 Pa and an argon flow rate of 15 mL / min. After the sublimation purification, 0.96 g of a light yellow solid was obtained with a yield of 69%.

[0315] The above compound was confirmed to be the target 2mBnf(II)BPDBq by nuclear magnetic resonance (NMR).

[0316] The following shows the obtained brown solid 1 H NMR data.

[0317] 1 H NMR (tetrachloroethane-d 2 ,500MHz): δ=7.49-7.55(m,3H),7.73-7.87(m,8H),7.90-7.94(m,2H),8.00(s,1H),8.04(d,J=7.5Hz,1H),8.07(d,J=7.5Hz,1H),8.12(d,J =8.5Hz,1H),8.37-8.39(m,2H),8.48(s,1H),8.67(d,J=8.0Hz,2H),8.74(s,1H),9.31(d,J=8.0Hz,1H),9.47(d,J=8.0Hz,1H),9.53(s,1H)

[0318] Fig. 8A and Figure 8B Show 1 H NMR spectra. Figure 8B yes Fig. 8A An enlarged view of the range from 7.00 ppm to 10.0 ppm.

[0319] Fig. 9A The absorption spectrum of the toluene solution of 2mBnf(II)BPDBq is shown. Fig. 9B Its emission spectrum is shown. In addition, Fig. 10A The absorption spectrum of the thin film of 2mBnf(II)BPDBq is shown. Fig. 10B Its emission spectrum is shown. The absorption spectrum was measured using an ultraviolet visible spectrophotometer (manufactured by JASCO Corporation, Model V550). The solution was placed in a quartz dish, and a thin film was evaporated on a quartz substrate to produce a sample for measurement. The absorption spectrum of the solution was obtained by subtracting the absorption spectrum of the quartz dish and toluene from the absorption spectrum of the quartz dish and the solution, and the absorption spectrum of the thin film was obtained by subtracting the absorption spectrum of the quartz substrate from the absorption spectrum of the thin film on the quartz substrate. Fig. 9A and Fig. 9B as well as Fig. 10A and Fig. 10BIn the figure, the horizontal axis represents wavelength (nm) and the vertical axis represents intensity (arbitrary unit). The absorption peaks of the toluene solution are located near 280nm, 310nm, 322nm, 340nm and 358nm, and the peaks of the emission wavelengths are located near 385nm and 404nm (the excitation wavelength is 358nm). In addition, the absorption peaks of the film are located near 258nm, 315nm, 327nm, 346nm, 365nm and 384nm, and the peak of the emission wavelength is located at 435nm (the excitation wavelength is 369nm).

[0320] The HOMO level and LUMO level of 2mBnf(II)BPDBq were measured by cyclic voltammetry (CV). CV measurement was performed using an electrochemical analyzer (ALS model 600A or 600C manufactured by BAS Inc.).

[0321] The solution used for CV measurement was dehydrated dimethylformamide (DMF, manufactured by Sigma-Aldrich Inc., 99.8%, catalog number: 22705-6) as a solvent, tetra-n-butylammonium perchlorate (n-Bu 4 NClO 4 , manufactured by Tokyo Chemical Industry Co., Ltd., catalog number: T0836) was dissolved in a solvent and the concentration of tetra-n-butylammonium perchlorate was 100 mmol / L. In addition, the object to be measured was dissolved in a solvent and the concentration was 2 mmol / L. In addition, a platinum electrode (manufactured by BAS Co., Ltd., PTE platinum electrode) was used as a working electrode, a platinum electrode (manufactured by BAS Co., Ltd., Pt counter electrode (5 cm) for VC-3) was used as an auxiliary electrode, and an Ag / Ag+ electrode (manufactured by BAS Co., Ltd., RE7 non-aqueous solvent type reference electrode) was used as a reference electrode. In addition, the measurement was carried out at room temperature (20°C to 25°C). The scanning speed during CV measurement was unified to 0.1 V / sec. In this embodiment, the potential energy of the reference electrode relative to the vacuum energy level was set to -4.94 [eV].

[0322] The oxidation peak potential E obtained by CV measurement pa and reduction peak potential E pc The potential in the middle (half-wave potential) is equivalent to the HOMO level, so the HOMO level of 2mBnf(II)BPDBq can be calculated to be -6.03eV, and the LUMO level of 2mBnf(II)BPDBq can also be calculated to be -2.95eV. Therefore, the band gap (ΔE) of 2mBnf(II)BPDBq is 3.08eV.

[0323] In addition, 2mBnf(II)BPDBq was subjected to mass spectrometry (MS) analysis using liquid chromatography-mass spectrometry (LC / MS analysis).

[0324] In the LC-MS analysis, LC (liquid chromatography) separation was performed using UltiMate3000 manufactured by Thermo Fisher Scientific, and MS analysis was performed using Q Exactive manufactured by Thermo Fisher Scientific. The chromatographic column used in the LC separation was Acquity UPLC BEH C8 (2.1×100 mm, 1.7 μm), and the column temperature was 40°C. The mobile phase A was acetonitrile, and the mobile phase B was a 0.1% formic acid aqueous solution. In the 10-minute analysis, acetonitrile was set to 70% at the beginning of the analysis and the ratio of acetonitrile was linearly increased to 95% 10 minutes after the start of the analysis. In addition, 2mBnf(II)BPDBq was dissolved in chloroform at an arbitrary concentration and diluted with acetonitrile to prepare the sample, and the injection volume was 5.0 μL.

[0325] In MS analysis, ionization is performed by electrospray ionization (ESI) and targeted-MS is used. 2 The ion source was set as follows: sheath gas flow rate was 50, auxiliary gas flow rate was 10, sweep gas flow rate was 0, spray voltage was 3.5 kV, capillary temperature was 380 ° C, S lens voltage was 55.0, and HESI heater temperature was 350 ° C. The resolution was 35000, the AGC target was 3e6, the mass range was m / z = 50.00-630.00, and detection was performed in positive mode.

[0326] The component with m / z = 599.21 ± 10 ppm ionized under the above conditions was collided with argon gas in a collision cell to dissociate into daughter ions, and MS / MS measurement was performed. The energy NCE (Normalized Collision Energy) when colliding with argon was set to 50, and the generated ions were detected by Fourier transform mass spectrometry (FT MS). Fig.11A and Fig. 11B The measurement results are shown.

[0327] Fig.11A and Fig. 11B It is shown that the product ions of 2mBnf(II)BPDBq are detected near m / z=381, near m / z=229, and near m / z=220. Fig.11A and Fig. 11BSince the characteristics derived from 2mBnf(II)BPDBq are shown, it can be said that this is important data for identifying 2mBnf(II)BPDBq contained in the mixture.

[0328] The daughter ions near m / z=381 are estimated to be cations derived from 2-(3,1'-biphenyl-1-yl)dibenzo[f,h]quinoxaline in 2mBnf(II)BPDBq, which represents a partial structure of a compound of one embodiment of the present invention. The daughter ions near m / z=229 are estimated to be cations derived from dibenzo[f,h]quinoxaline in 2mBnf(II)BPDBq, which represents a partial structure of a compound of one embodiment of the present invention. In addition, the daughter ions near m / z=220 are estimated to be cations (structural formula (10) or structural formula (11)) derived from the structure of an alcohol formed by the cleavage of the ether bond of benzo[b]naphtho[2,3-d]furan, which represents a partial structure of a compound of one embodiment of the present invention.

[0329]

[0330] The product ions near m / z = 572 are estimated to be cations derived from a state in which one CH and one N are separated from dibenzo[f,h]quinoxaline in 2mBnf(II)BPDBq, which indicates a partial structure of a compound of one embodiment of the present invention. This is one of the characteristics of a compound of one embodiment of the present invention in which a substituent (a biphenyl skeleton and a benzo[b]naphtho[2,3-d]furan skeleton in 2mBnf(II)BPDBq) is bonded to the 2-position of dibenzo[f,h]quinoxaline.

[0331] In addition, the phosphorescence measurement of 2mBnf(II)BPDBq was performed.

[0332] A vapor-deposited film of 2mBnf(II)BPDBq was formed and low-temperature PL (photoluminescence) measurement was performed. In this measurement, a microscopic PL device LabRAM HR-PL (manufactured by Horiba, Ltd., Japan) was used, a He-Cd laser (325 nm) was used as the excitation light, a CCD detector was used as the detector, and the measurement temperature was set to 10K.

[0333] The above-mentioned vapor-deposited film was formed on a quartz substrate with a thickness of 50 nm, and another quartz substrate was bonded to the vapor-deposited surface in a nitrogen atmosphere before measurement.

[0334] From the measurement results, it was found that the peak of the shortest wavelength side of the phosphorescence spectrum was located at 536 nm. 1 The energy level is 2.31eV.

[0335] The thin film of 2mBnf(II)BPDBq is not easy to aggregate and change its morphology in the atmosphere, and has good film quality.

[0336] The decomposition temperature Td of 2mBnf(II)BPDBq under atmospheric pressure was measured by thermogravimetry-differential thermal analysis (TG-DTA), and it was found that the decomposition temperature Td was 500° C. or higher, indicating good heat resistance. A high vacuum differential thermal balance (manufactured by Bruker AXS KK, TG-DTA2410SA) was used for the measurement.

[0337] In addition, the thermal properties were measured using a differential scanning calorimeter (DSC, manufactured by PerkinElmer, Inc., Pyris 1DSC). In the measurement, the sample was kept at -10°C for 1 minute, the temperature was raised from -10°C to 350°C at a rate of 50°C / min, and then kept at 350°C for 1 minute, and then the temperature was lowered from 350°C to -10°C at a rate of 50°C / min, and this step was considered as one cycle. The measurement was performed for two cycles, and the thermal properties were measured from the data in the two cycles. It can be seen that the glass transition temperature Tg of 2mBnf(II)BPDBq is 119°C, the crystallization temperature Tc is 206°C, and the melting point Tm is 285°C and 300°C. It can be seen that 2mBnf(II)BPDBq has a high glass transition temperature, melting point and decomposition temperature, and has good heat resistance.

[0338] Example 2

[0339] In this embodiment, refer to Fig.12 A light-emitting element according to one embodiment of the present invention is described below. Chemical formulas of materials used in this embodiment are shown below. Note that chemical formulas of materials that have already been shown are omitted.

[0340]

[0341] Next, a method for manufacturing the light emitting element 1 of this embodiment is described.

[0342] (Light-emitting element 1)

[0343] An indium tin oxide (ITSO) film containing silicon was formed on a glass substrate 1100 by a sputtering method, thereby forming a first electrode 1101 serving as an anode. The thickness was set to 110 nm, and the electrode area was set to 2 mm×2 mm.

[0344] Next, as a pretreatment for forming a light-emitting element on the glass substrate 1100, the surface of the glass substrate 1100 was washed with water and baked at 200°C for 1 hour, and then subjected to UV ozone treatment for 370 seconds.

[0345] Then, the glass substrate 1100 is placed inside the chamber and the pressure is reduced to 10 -4 The glass substrate 1100 is vacuum-baked at 170° C. for 30 minutes in a heating chamber in the vacuum evaporation device at a temperature of about 170° C., and then cooled for about 30 minutes.

[0346] Next, the glass substrate 1100 having the first electrode 1101 formed thereon is fixed on a substrate holder provided in a vacuum evaporation apparatus in such a manner that the surface having the first electrode 1101 formed thereon faces downward, and the pressure is reduced to 10 -4 Pa, and then 4,4',4"-(1,3,5-benzenetriyl)tri(dibenzothiophene) (abbreviated as: DBT3P-II) and molybdenum (VI) oxide are co-evaporated on the first electrode 1101 to form a hole injection layer 1111. The thickness of the hole injection layer 1111 is set to 20nm, and the weight ratio of DBT3P-II to molybdenum oxide is adjusted to 4:2 (=DBT3P-II: molybdenum oxide). Note that the co-evaporation method refers to an evaporation method in which evaporation is performed simultaneously from multiple evaporation sources in one processing chamber.

[0347] Next, a film of 4-phenyl-4′-(9-phenylfluorene-9-yl)triphenylamine (abbreviated as BPAFLP) was formed to a thickness of 20 nm on the hole injection layer 1111 to form the hole transport layer 1112 .

[0348] Next, 2mBnf(II)BPDBq, N-(1,1'-biphenyl-4-yl)-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-9,9-dimethyl-9H-fluoren-2-amine (abbreviated as PCBBiF), and (acetylacetonato)bis(4,6-diphenylpyrimidinato)iridium(III) (abbreviated as [Ir(dppm) 2 (acac)]) was co-evaporated to form a light-emitting layer 1113 on the hole transport layer 1112. Here, 2mBnf(II)BPDBq, PCBBiF and [Ir(dppm) 2 The weight ratio of (acac)] was adjusted to 0.7:0.3:0.05 (=2mBnf(II)BPDBq:PCBBiF:[Ir(dppm) 2 (acac)]) to form a 20 nm thick layer, and the weight ratio thereof was adjusted to 0.8:0.2:0.05 (=2mBnf(II)BPDBq:PCBBiF:[Ir(dppm) 2(acac)]) stacked with a 20 nm thick layer.

[0349] Next, a 20-nm-thick film of 2mBnf(II)BPDBq and a 10-nm-thick film of bathophenanthroline (abbreviation: BPhen) were formed over the light-emitting layer 1113 , thereby forming an electron-transport layer 1114 .

[0350] Then, a lithium fluoride (LiF) film was formed to a thickness of 1 nm over the electron-transport layer 1114 to form the electron-injection layer 1115 .

[0351] Finally, an aluminum film was formed to a thickness of 200 nm to form the second electrode 1103 functioning as a cathode, thereby manufacturing the light-emitting element 1 of this example.

[0352] In the above-mentioned evaporation process, the evaporation is performed by using a resistance heating method.

[0353] Table 1 shows the element structure of the light-emitting element of this example obtained through the above steps.

[0354] [Table 1]

[0355]

[0356] The light-emitting element of this example was sealed in a glove box of nitrogen atmosphere so as not to be exposed to the air. Then, the operating characteristics of the light-emitting element were measured. The measurement was performed at room temperature (atmosphere maintained at 25° C.).

[0357] Fig.13 The voltage-luminance characteristics of the light emitting element 1 are shown. Fig.13 In the figure, the horizontal axis represents voltage (V) and the vertical axis represents brightness (cd / m 2 ). Fig.14 The brightness-current efficiency characteristics are shown. Fig.14 In the figure, the horizontal axis represents brightness (cd / m 2 ), and the vertical axis represents the current efficiency (cd / A). Fig.15 The voltage-current characteristics are shown. Fig.15 In the figure, the horizontal axis represents voltage (V) and the vertical axis represents current (mA). Fig.16 The light emission spectrum of the light emitting element 1 is shown. Fig.16 In the table, the horizontal axis represents wavelength (nm) and the vertical axis represents luminous intensity (arbitrary unit). In addition, Table 2 shows that the brightness is 900 cd / m 2 The voltage (V) and current density (mA / cm 2 ), CIE chromaticity coordinates (x, y), current efficiency (cd / A), power efficiency (lm / W) and external quantum efficiency (%).

[0358] [Table 2]

[0359]

[0360] Brightness: 900cd / m 2 The CIE chromaticity coordinates of the light-emitting element 1 at this time are (x, y) = (0.57, 0.43), showing orange light emission. From this result, it can be seen that the light-emitting element 1 obtains the [Ir (dppm) 2 (acac)] orange light.

[0361] The measurement results of the operating characteristics show that the light-emitting element 1 has high light-emitting efficiency and low driving voltage.

[0362] Furthermore, a reliability test of the light emitting element 1 was performed. Fig.17 The results of the reliability test are shown in Fig.17 The vertical axis represents the normalized brightness (%) when the initial brightness is 100%, and the horizontal axis represents the driving time (h) of the element. The reliability test was conducted at room temperature and the initial brightness was set to 5000 cd / m 2 , driving the light emitting element 1 under the condition of constant current density. Fig.17 As shown, the brightness of the light emitting element 1 after 1300 hours remains 91% of the initial brightness. According to the results of this reliability test, the life of the light emitting element 1 is very long.

[0363] Example 3

[0364] In this example, the results of manufacturing a light-emitting element according to one embodiment of the present invention and performing a storage test are described. The chemical formulas of the materials used in this example are shown below. Note that the chemical formulas of the materials that have already been shown are omitted.

[0365]

[0366] Next, a method for manufacturing the light emitting element 2 of this embodiment is described. The structure of the light emitting element of this embodiment can be referred to Fig.12 .

[0367] (Light-emitting element 2)

[0368] In the light-emitting element 2, components other than the light-emitting layer 1113 are manufactured in the same manner as the light-emitting element 1. Here, only components different from the light-emitting element 1 will be described.

[0369] The light-emitting layer 1113 of the light-emitting element 2 is prepared by mixing 2mBnf(II)BPDBq, PCBBiF and (acetylacetonato)bis(6-tert-butyl-4-phenylpyrimidine)iridium(III) (abbreviated as [Ir(tBuppm) 2Here, 2mBnf(II)BPDBq, PCBBiF and [Ir(tBuppm) 2 The weight ratio of (acac)] was adjusted to 0.7:0.3:0.05 (=2mBnf(II)BPDBq:PCBBiF:[Ir(tBuppm) 2 (acac)]) to form a 20 nm thick layer, and the weight ratio thereof was adjusted to 0.8:0.2:0.05 (=2mBnf(II)BPDBq:PCBBiF:[Ir(tBuppm) 2 (acac)]) stacked with a 20 nm thick layer.

[0370] Table 3 shows the element structure of the light-emitting element of this example obtained through the above steps.

[0371] [Table 3]

[0372]

[0373] In this example, the manufactured light emitting element was stored in a thermostatic chamber maintained at 100° C., and the operating characteristics were measured after a predetermined time. The light emitting element was taken out of the thermostatic chamber and the operating characteristics were measured at room temperature (atmosphere maintained at 25° C.).

[0374] Fig.18 The voltage-current characteristics of the light-emitting element after being stored at 100° C. for 200 hours are shown. Fig.19 The brightness-external quantum efficiency characteristics are shown. Fig.18 and Fig.19 In FIG. 1 , the characteristics of the light-emitting element before the storage test and the characteristics after storage for 25 hours and 50 hours are also shown.

[0375] from Fig.18 and Fig.19 It can be seen that even if the light-emitting element of this embodiment is stored at 100°C for 200 hours, the changes in voltage-current characteristics and brightness-external quantum efficiency characteristics are small, and it can be seen that the element characteristics are almost not degraded. It can be seen that by using a compound of one embodiment of the present invention, a light-emitting element with high heat resistance and high reliability can be realized.

[0376] Explanation of symbols

[0377] 201 First Electrode

[0378] 203 EL layer

[0379] 203a First EL layer

[0380] 203b Second EL layer

[0381] 205 Second electrode

[0382] 207 Middle Layer

[0383] 301 Hole injection layer

[0384] 302 Hole transport layer

[0385] 303 Luminous Layer

[0386] 304 Electron Transport Layer

[0387] 305 Electron injection layer

[0388] 310 Portable Information Terminal

[0389] 312 Display Panel

[0390] 313 Hinge

[0391] 315 Housing

[0392] 320 Portable Information Terminal

[0393] 322 Display

[0394] 325 Non-display part

[0395] 330 Portable Information Terminal

[0396] 333 Display

[0397] 335 Housing

[0398] 336 Housing

[0399] 337 Information

[0400] 339 Operation Button

[0401] 340 Portable Information Terminal

[0402] 345 Portable Information Terminal

[0403] 351 Housing

[0404] 355 Information

[0405] 356 Information

[0406] 357 Information

[0407] 358 Display

[0408] 401 Support substrate

[0409] 403 Light emitting element

[0410] 405 Sealing substrate

[0411] 407 sealant

[0412] 409a First terminal

[0413] 409b Second terminal

[0414] 411a Light extraction structure

[0415] 411b Light extraction structure

[0416] 413 Planarization layer

[0417] 415 Space

[0418] 417 Auxiliary wiring

[0419] 419 Insulation layer

[0420] 421 First Electrode

[0421] 423 EL layer

[0422] 425 Second Electrode

[0423] 501 Support substrate

[0424] 503 Light-emitting element

[0425] 504 Light emitting element

[0426] 505 Sealing substrate

[0427] 506 Desiccant

[0428] 507 sealant

[0429] 509 FPC

[0430] 511 First insulation layer

[0431] 513 Second insulation layer

[0432] 515 Space

[0433] 517 Lead

[0434] 519 Next Door

[0435] 521 First Electrode

[0436] 523 EL layer

[0437] 525 Second Electrode

[0438] 531 Black Matrix

[0439] 533 Color Filter

[0440] 535 protective layer

[0441] 541a Transistor

[0442] 541b Transistor

[0443] 542 transistors

[0444] 543 Transistors

[0445] 551 Luminous Department

[0446] 551a Light emitting unit

[0447] 551b Light-emitting unit

[0448] 552 Drive Circuit Department

[0449] 553 Drive circuit department

[0450] 561 First Electrode

[0451] 563 EL layer

[0452] 565 Second Electrode

[0453] 1100 Glass substrate

[0454] 1101 First Electrode

[0455] 1103 Second electrode

[0456] 1111 Hole injection layer

[0457] 1112 Hole transport layer

[0458] 1113 Luminescent layer

[0459] 1114 Electron transport layer

[0460] 1115 Electron injection layer

[0461] 7100 TV set

[0462] 7101 Housing

[0463] 7102 Display unit

[0464] 7103 Bracket

[0465] 7111 Remote Control Machine

[0466] 7200 Computer

[0467] 7201 Main Body

[0468] 7202 Housing

[0469] 7203 Display unit

[0470] 7204 Keyboard

[0471] 7205 External connection port

[0472] 7206 Pointing Device

[0473] 7300 Portable Game Console

[0474] 7301a Housing

[0475] 7301b Housing

[0476] 7302 Connection

[0477] 7303a Display unit

[0478] 7303b Display unit

[0479] 7304 Speaker Department

[0480] 7305 Recording media insertion section

[0481] 7306 Operation keys

[0482] 7307 Connector Terminal

[0483] 7308 Sensor

[0484] 7400 Mobile Phone

[0485] 7401 Housing

[0486] 7402 Display unit

[0487] 7403 Operation Button

[0488] 7404 External connection port

[0489] 7405 Speaker

[0490] 7406 Microphone

[0491] 7500 Tablet Terminal

[0492] 7501a Housing

[0493] 7501b Housing

[0494] 7502a Display unit

[0495] 7502b Display

[0496] 7503 Shaft

[0497] 7504 Power Supply

[0498] 7505 Operation keys

[0499] 7506 Speaker

[0500] 7601 Lighting fixtures

[0501] 7602 Lighting fixtures

[0502] 7603 Table lighting fixture

[0503] 7604 Planar lighting device

[0504] 7701 Lighting Department

[0505] 7703 Pillar

[0506] 7705 Bracket

Claims

1. A compound represented by formula (G3): in: R 1 To R 9 and R 11 To R 19 Each of them represents any one of hydrogen, an alkyl group having 1 to 6 carbon atoms, a cycloalkyl group having 3 to 6 carbon atoms, and an aryl group having 6 to 13 carbon atoms; Ar represents an arylene group having 6 to 25 carbon atoms; and The aryl group and the arylene group are each unsubstituted or substituted with an alkyl group having 1 to 6 carbon atoms.

2. The compound according to claim 1, wherein the compound is represented by formula (101):

3. A method for synthesizing an organic compound represented by formula (G2), the method comprising: reaction of a first compound represented by formula (G5) with a second compound represented by formula (G6), in: A represents a substituted or unsubstituted dibenzo[f,h]quinoxalinyl group; Ar represents a substituted or unsubstituted arylene group having 6 to 25 carbon atoms; X 1 and X 2 Each represents any one of a halogen, a trifluoromethylsulfonyl group, a boronic acid group, an organic boron group, a magnesium halide group and an organic tin group; R 1 To R 9 Each represents any one of hydrogen, an alkyl group having 1 to 6 carbon atoms, a cycloalkyl group having 3 to 6 carbon atoms, and an aryl group having 6 to 13 carbon atoms. 4 . The method for synthesizing an organic compound according to claim 3 , wherein the halogen represents any one of chlorine, bromine and iodine.

5. The method for synthesizing an organic compound according to claim 3, wherein X 1 and X 2 One of them represents a halogen, and X 1 and X 2 The other in the above-mentioned group represents any one of a trifluoromethylsulfonyl group, a boronic acid group and an organic boron group.

6. The method for synthesizing an organic compound according to claim 3, wherein a palladium catalyst is used for the reaction.

7. The method for synthesizing an organic compound according to claim 3, wherein copper or a copper compound is used for the reaction.

8. An organic compound represented by formula (G4): in: R 1 To R 9 each represents any one of hydrogen, an alkyl group having 1 to 6 carbon atoms, a cycloalkyl group having 3 to 6 carbon atoms, and an aryl group having 6 to 13 carbon atoms; and R 10 Represents chlorine. 9 . The organic compound according to claim 8 , wherein when the aryl group has a substituent, the substituent is selected from any one of an alkyl group having 1 to 6 carbon atoms, a cycloalkyl group having 3 to 6 carbon atoms, and an aryl group having 6 to 13 carbon atoms.

10. The organic compound according to claim 8, wherein R 1 To R 9 They represent hydrogen respectively.

11. The organic compound according to claim 8, wherein the organic compound is represented by formula (201) or (213):

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