Organic compound, light-emitting element, light-emitting device, electronic device, and lighting device

Abstract

The present invention provides a novel organometallic complex. In addition, one embodiment of the present invention provides a novel organometallic complex with high quantum yield. A ligand comprises a 1H-naphtho[1,2-d]imidazole skeleton and has an Ir complex having a structure represented by the following general formula (G-1). In the N included in the 1H-naphtho[1,2-d]imidazole skeleton, the N not bonded to Ir is bonded to a substituted or unsubstituted aryl group. In the general formula (G-1), R1 to R10 each independently represent hydrogen, an alkyl group having 1 to 6 carbon atoms, a cycloalkyl group having 3 to 7 substituted or unsubstituted carbon atoms, an aryl group having 6 to 25 substituted or unsubstituted carbon atoms, or an electron-withdrawing group, and Ar represents an aryl group having 6 to 25 substituted or unsubstituted carbon atoms.

Description

Technical Field

[0001] One embodiment of the present invention relates to a novel organic compound, in particular, to an organometallic complex whose ligand comprises a 1H-naphtho[1,2-d]imidazole skeleton. In addition, one embodiment of the present invention also relates to a light-emitting element, a light-emitting device, an electronic device, and a lighting device comprising the organometallic complex.

[0002] Note that one embodiment of the present invention is not limited to the above-mentioned technical field. One embodiment of the present invention relates to an object, a method or a manufacturing method. In particular, one embodiment of the present invention relates to an organic compound, a light-emitting element, a light-emitting device, a lighting device, and a method for manufacturing the same. In addition, one embodiment of the present invention relates to a novel method for synthesizing an organometallic complex whose ligand contains a 1H-naphtho[1,2-d]imidazole skeleton. Therefore, as a specific example of one embodiment of the present invention disclosed in this specification, a method for manufacturing a light-emitting element, a light-emitting device, a display device, an electronic device and a lighting device containing the organometallic complex can be cited. Background Art

[0003] In recent years, the practical application of light-emitting elements (organic EL elements) using electroluminescence (EL) using organic compounds has been very active. In the basic structure of these light-emitting elements, an organic compound layer (EL layer) containing a light-emitting material is sandwiched between a pair of electrodes. By applying voltage to the element, carriers are injected, and the recombination energy of the carriers is used to obtain light emission from the light-emitting material.

[0004] This light-emitting element is a self-luminous light-emitting element. When used as a pixel of a display, it has advantages such as high visibility and no need for a backlight source. Therefore, this light-emitting element is suitable for flat-panel display elements. In addition, the display using this light-emitting element can be made thin and light, which is also a major advantage. In addition, one of its characteristics is that the response speed is extremely fast.

[0005] Because the light-emitting layer of this light-emitting element can be continuously formed in two dimensions, planar light emission can be obtained. This is a feature that is difficult to obtain in point light sources represented by incandescent lamps or LEDs or line light sources represented by fluorescent lamps. In addition, by selecting materials, the light emission of organic compounds can be made to be light emission without ultraviolet light, which has a high utilization value as a surface light source that can be applied to lighting, etc.

[0006] As mentioned above, displays or lighting devices using organic EL elements are suitable for various electronic devices, and research and development of light-emitting elements with higher efficiency and longer element life are increasingly active. In recent years, the luminous efficiency of phosphorescent light-emitting elements is higher than that of fluorescent light-emitting elements, so the research and development of phosphorescent light-emitting elements is increasingly strengthened (for example, refer to Patent Document 1).

[0007] [Prior technical literature]

[0008] [Patent Document]

[0009] [Patent Document 1] Japanese Patent Application Publication No. 2013-147496 Summary of the invention

[0010] Technical problem to be solved by the invention

[0011] As reported in Patent Document 1, the development of phosphorescent materials having excellent properties has progressed, but the development of novel materials having even better properties is desired. In particular, the development of blue or green phosphorescent materials having high efficiency and high reliability is desired.

[0012] Therefore, an object of one embodiment of the present invention is to provide a novel organometallic complex. In addition, an object of one embodiment of the present invention is to provide a novel organometallic complex comprising a 1H-naphtho[1,2-d]imidazole skeleton. In addition, an object of one embodiment of the present invention is to provide an organometallic complex with a high quantum yield. In addition, an object of one embodiment of the present invention is to provide a light-emitting element with good luminous efficiency. In addition, an object of one embodiment of the present invention is to provide a light-emitting element with good life. In addition, an object of one embodiment of the present invention is to provide a light-emitting element with good color purity. In addition, an object of one embodiment of the present invention is to provide a light-emitting element with a low driving voltage.

[0013] Another aspect of the present invention aims to provide a light emitting element, a light emitting device, and an electronic device with high reliability. Another aspect of the present invention aims to provide a light emitting element, a light emitting device, and an electronic device with low power consumption.

[0014] Note that the recording 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. In addition, the purposes other than the above can be clearly seen from the description of the specification, drawings, claims, etc., and the purposes other than the above can be extracted from the description of the specification, drawings, claims, etc.

[0015] Solutions to technical problems

[0016] One embodiment of the present invention is an organometallic complex having a structure represented by the following general formula (G-1), wherein the ligand includes a 1H-naphtho[1,2-d]imidazole skeleton.

[0017] [Chemical formula 1]

[0018]

[0019] In the general formula (G-1), R 1 To R 10 Each independently represents hydrogen, an alkyl group having 1 to 6 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 7 carbon atoms, a substituted or unsubstituted aryl group having 6 to 25 carbon atoms, or an electron withdrawing group, and Ar represents a substituted or unsubstituted aryl group having 6 to 25 carbon atoms.

[0020] Another embodiment of the present invention is an organometallic complex having a structure represented by General Formula (G-2).

[0021] [Chemical formula 2]

[0022]

[0023] In the general formula (G-2), R 1 To R 15 Each independently represents hydrogen, an alkyl group having 1 to 6 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 7 carbon atoms, a substituted or unsubstituted aryl group having 6 to 25 carbon atoms, or an electron withdrawing group.

[0024] Another embodiment of the present invention is an organometallic complex having a structure represented by General Formula (G-3).

[0025] [Chemical formula 3]

[0026]

[0027] In the general formula (G-3), R 11 , R 13 and R 15 Each independently represents hydrogen, an alkyl group having 1 to 6 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 7 carbon atoms, a substituted or unsubstituted aryl group having 6 to 25 carbon atoms, or an electron withdrawing group.

[0028] Another embodiment of the present invention is an organometallic complex having a structure represented by the general formula (G-4).

[0029] [Chemical formula 4]

[0030]

[0031] In the general formula (G-4), R 13 represents hydrogen or an electron-withdrawing group.

[0032] Another embodiment of the present invention is an organometallic complex having a structure represented by General Formula (G-5).

[0033] [Chemical formula 5]

[0034]

[0035] In the general formula (G-5), R 15 It represents hydrogen, an alkyl group having 1 to 6 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 7 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 25 carbon atoms.

[0036] In the above structure, the general formula (G-1) is preferably represented by the general formula (G-6).

[0037] [Chemical formula 6]

[0038]

[0039] In the above structure, the general formula (G-2) is preferably represented by the general formula (G-7).

[0040] [Chemical formula 7]

[0041]

[0042] In the above structure, the general formula (G-3) is preferably represented by the general formula (G-8).

[0043] [Chemical formula 8]

[0044]

[0045] In the above structure, the general formula (G-4) is preferably represented by the general formula (G-9).

[0046] [Chemical formula 9]

[0047]

[0048] In the above structure, the general formula (G-5) is preferably represented by the general formula (G-10).

[0049] [Chemical formula 10]

[0050]

[0051] In the above structure, the general formula (G-1) is preferably represented by the general formula (G-11).

[0052] [Chemical formula 11]

[0053]

[0054] In the general formula (G-11), L represents a monoanionic ligand, and n represents 1 or 2.

[0055] In the above structure, the general formula (G-2) is preferably represented by the general formula (G-12).

[0056] [Chemical formula 12]

[0057]

[0058] In the general formula (G-12), L represents a monoanionic ligand, and n represents 1 or 2.

[0059] In the above structure, the general formula (G-3) is preferably represented by the general formula (G-13).

[0060] [Chemical formula 13]

[0061]

[0062] In the general formula (G-13), L represents a monoanionic ligand, and n represents 1 or 2.

[0063] In the above structure, the general formula (G-4) is preferably represented by the general formula (G-14).

[0064] [Chemical formula 14]

[0065]

[0066] In the general formula (G-14), L represents a monoanionic ligand, and n represents 1 or 2.

[0067] In the above structure, the general formula (G-5) is preferably represented by the general formula (G-15).

[0068] [Chemical formula 15]

[0069]

[0070] In the general formula (G-15), L represents a monoanionic ligand, and n represents 1 or 2.

[0071] In the general formulas (G-3), (G-8) and (G-13), R 11 and R 15 Each independently represents hydrogen, an alkyl group having 1 to 6 carbon atoms, or a substituted or unsubstituted cycloalkyl group having 3 to 7 carbon atoms, R 13 represents hydrogen or an electron-withdrawing group.

[0072] In addition, in the above structure, the electron withdrawing group is preferably any one of a halide group, a cyano group, and a trifluoromethyl group.

[0073] In the above structure, the alkyl group is a branched alkyl group preferably having 3 to 6 carbon atoms.

[0074] In addition, in the above structure, the monoanionic ligand is preferably a monoanionic bidentate chelating ligand having a β-diketone structure, a monoanionic bidentate chelating ligand having a carboxyl group, a monoanionic bidentate chelating ligand having a phenolic hydroxyl group, or a monoanionic bidentate chelating ligand in which both coordinating elements are nitrogen, or a bidentate ligand that forms iridium and a metal-carbon bond by cyclometallation.

[0075] Furthermore, in the above structure, the monoanionic ligand is preferably any one of the following general formulae (L1) to (L9).

[0076] [Chemical formula 16]

[0077]

[0078] In the general formulae (L1) to (L9), R 21 To R 86 Each independently represents hydrogen or a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms, a halo group, a vinyl group, a cyano group, a substituted or unsubstituted haloalkyl group having 1 to 6 carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 6 carbon atoms, a substituted or unsubstituted alkylthio group having 1 to 6 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 13 carbon atoms. In addition, A 1 To A 13 Each independently represents nitrogen or sp bonded to hydrogen 2 Hybridized carbon or sp with substituents 2 The hybrid carbon and the substituent represent any one of an alkyl group having 1 to 6 carbon atoms, a halogenated group, a halogenated alkyl group having 1 to 6 carbon atoms, and a phenyl group.

[0079] Another embodiment of the present invention is an organic compound represented by any one of the following structural formulas (100) to (103).

[0080] [Chemical formula 17]

[0081]

[0082] Another embodiment of the present invention is a light-emitting element including an EL layer between a pair of electrodes, wherein the EL layer includes the organic compound described in the above-mentioned structures. The organic compound is preferably included in a light-emitting layer in the EL layer.

[0083] In addition, the light-emitting element having the above structure includes an EL layer between the anode and the cathode. Preferably, the EL layer includes at least a light-emitting layer. The EL layer may also include a hole injection layer, a hole transport layer, an electron transport layer, an electron injection layer or other functional layers.

[0084] In addition, another embodiment of the present invention is a display device, comprising: a light-emitting element having the above structure; and at least one of a color filter and a transistor. In addition, another embodiment of the present invention is an electronic device, comprising: the display device; and at least one of a housing and a touch sensor. In addition, another embodiment of the present invention is a lighting device, comprising: a light-emitting element having the above structure; and at least one of a housing and a touch sensor. In addition, one embodiment of the present invention includes not only a light-emitting device having a light-emitting element, but also an electronic device having a light-emitting device in its scope. Therefore, the light-emitting device in this specification refers to an image display device or a light source (including a lighting device). In addition, the following display module is also a mode of the present invention: a display module in which a connector such as an FPC (Flexible Printed Circuit) or a TCP (Tape Carrier Package) is installed in the light-emitting element; a display module in which a printed circuit board is provided at the end of the TCP; or a display module in which an IC (integrated circuit) is directly mounted on the light-emitting element by a COG (Chip On Glass) method.

[0085] Effects of the Invention

[0086] According to one embodiment of the present invention, a novel organometallic complex can be provided. In addition, according to one embodiment of the present invention, a novel organometallic complex comprising a 1H-naphtho[1,2-d]imidazole skeleton can be provided. In addition, according to one embodiment of the present invention, an organometallic complex with high quantum yield can be provided. In addition, according to one embodiment of the present invention, a light-emitting element with good luminous efficiency can be provided. In addition, according to one embodiment of the present invention, a light-emitting element with good life can be provided. In addition, according to one embodiment of the present invention, a light-emitting element with good color purity can be provided. In addition, according to one embodiment of the present invention, a light-emitting element with low driving voltage can be provided.

[0087] According to another embodiment of the present invention, a light emitting element, a light emitting device, and an electronic device with high reliability can be provided. According to another embodiment of the present invention, a light emitting element, a light emitting device, and an electronic device with low power consumption can be provided.

[0088] Note that the description of these effects does not prevent the existence of other effects. Note that one mode of the present invention does not necessarily achieve all of the above effects. In addition, the effects other than the above can be clearly seen from the description of the specification, drawings, claims, etc., and the effects other than the above can be extracted from the description of the specification, drawings, claims, etc.

[0089] BRIEF DESCRIPTION OF THE DRAWINGS

[0090] [Figure 1] Figure 1A and Figure 1B This is a schematic diagram of a light-emitting element according to one embodiment of the present invention. Figure 1C FIG. 1 is a diagram illustrating the correlation of energy levels of a light-emitting element according to one embodiment of the present invention.

[0091] [ Figure 2 ] Figure 2 This is a schematic diagram of a light-emitting element according to one embodiment of the present invention.

[0092] [Figure 3] Figure 3A and Figure 3B FIG. 1 is a schematic diagram of an active matrix light-emitting device according to one embodiment of the present invention.

[0093] [Figure 4] Figure 4A and Figure 4B FIG. 1 is a schematic diagram of an active matrix light-emitting device according to one embodiment of the present invention.

[0094] [ Figure 5 ] Figure 5 FIG. 1 is a schematic diagram of an active matrix light-emitting device according to one embodiment of the present invention.

[0095] [Figure 6] FIG. 6A to FIG. 6D FIG. 1 is a diagram showing an electronic device according to one embodiment of the present invention.

[0096] [Figure 7] 7A to 7E FIG. 1 is a diagram showing an electronic device according to one embodiment of the present invention.

[0097] [Figure 8] FIG. 8A to FIG. 8C FIG. 1 is a diagram showing an electronic device according to one embodiment of the present invention.

[0098] [Figure 9] Fig. 9A and Fig. 9B FIG. 1 is a diagram showing an electronic device according to one embodiment of the present invention.

[0099] [Figure 10] FIG. 10A to FIG. 10C This is a diagram showing a lighting device according to one embodiment of the present invention.

[0100] [ Fig.11 ] Fig.11 This is a diagram showing a lighting device according to one embodiment of the present invention.

[0101] [ Fig.12 ] Fig.12 is a diagram illustrating NMR spectra of compounds according to Examples.

[0102] [ Fig.13 ] Fig.13 Graphs illustrating absorption spectra and emission spectra of compounds according to Examples.

[0103] [ Fig.14 ] Fig.14 is a diagram illustrating NMR spectra of compounds according to Examples.

[0104] [ Fig.15 ] Fig.15 Graphs illustrating absorption spectra and emission spectra of compounds according to Examples.

[0105] [ Fig.16 ] Fig.16 Graphs illustrating absorption spectra and emission spectra of compounds according to Examples.

[0106] [ Fig.17 ] Fig.17 is a diagram illustrating NMR spectra of compounds according to Examples.

[0107] [ Fig.18 ] Fig.18 Graphs illustrating absorption spectra and emission spectra of compounds according to Examples.

[0108] [ Fig.19 ] Fig.19 is a diagram illustrating current efficiency-luminance characteristics of a light emitting element according to an example.

[0109] [ Fig. 20 ] Fig. 20 is a diagram illustrating current density-voltage characteristics of a light emitting element according to an embodiment.

[0110] [ Fig.21 ] Fig.21 1 is a diagram illustrating external quantum efficiency-luminance characteristics of a light emitting element according to an example.

[0111] [ Fig. 22 ] Fig. 22 is a diagram illustrating an emission spectrum of a light emitting element according to an embodiment.

[0112] [ Fig.23 ] Fig.23 is a diagram illustrating current efficiency-luminance characteristics of a light emitting element according to an example.

[0113] [ Fig.24 ] Fig.24 is a diagram illustrating current density-voltage characteristics of a light emitting element according to an embodiment.

[0114] [ Fig.25 ] Fig.25 1 is a diagram illustrating external quantum efficiency-luminance characteristics of a light emitting element according to an example.

[0115] [ Fig.26 ] Fig.26 is a diagram illustrating an emission spectrum of a light emitting element according to an embodiment.

[0116] [ Fig. 27 ] Fig. 27 2 is a diagram illustrating the reliability test results of the light emitting element according to the embodiment.

[0117] [ Fig.28 ] Fig.28 : is a graph illustrating current efficiency-luminance characteristics of a light emitting element according to an example.

[0118] [ Fig.29 ] Fig.29 is a diagram illustrating current density-voltage characteristics of a light emitting element according to an embodiment.

[0119] [ Fig.30 ] Fig.30 1 is a diagram illustrating external quantum efficiency-luminance characteristics of a light emitting element according to an example.

[0120] [ Fig.31 ] Fig.31 is a diagram illustrating an emission spectrum of a light emitting element according to an embodiment.

[0121] Modes for Carrying Out the Invention

[0122] The embodiments of the present invention are described below with reference to the accompanying drawings. However, a person skilled in the art can easily understand that the present invention can be implemented in a plurality of different forms, and its 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.

[0123] In addition, in each of the drawings described in this specification, the size or thickness of the anode, EL layer, intermediate layer, cathode, etc. may be exaggerated for convenience of explanation. Therefore, the size of each component is not limited to the size shown in the drawings, and the relative size of each component is not limited.

[0124] Note that in this specification, etc., for the sake of convenience, ordinal numbers such as first, second, and third are added, but they do not indicate the order of processes or the upper and lower positional relationship, etc. Therefore, for example, "first" can be appropriately replaced with "second" or "third" to explain. In addition, sometimes the ordinal numbers recorded in this specification, etc. are inconsistent with the ordinal numbers used to specify one embodiment of the present invention.

[0125] In addition, in the structure of the present invention described in this specification, the same reference numerals are used in common between different drawings to represent the same part or part with the same function, and their repeated description is omitted. In addition, sometimes the same hatching is used to represent the part with the same function without adding a reference numeral.

[0126] In addition, in this specification, "film" and "layer" may be interchanged depending on the situation or state. For example, "conductive layer" may be interchanged with "conductive film". Or, "insulating film" may be interchanged with "insulating layer".

[0127] (Implementation Method 1)

[0128] In this embodiment, an organometallic complex which is one embodiment of the present invention is described.

[0129] The organometallic complex according to one embodiment of the present invention has a structure represented by the following general formula (G-1).

[0130] [Chemical formula 18]

[0131]

[0132] In the general formula (G-1), R 1 To R 10 Each independently represents hydrogen, an alkyl group having 1 to 6 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 7 carbon atoms, a substituted or unsubstituted aryl group having 6 to 25 carbon atoms, or an electron withdrawing group, and Ar represents a substituted or unsubstituted aryl group having 6 to 25 carbon atoms.

[0133] In the organometallic complex of one embodiment of the present invention, the ligand includes a 1H-naphtho[1,2-d]imidazole skeleton. By adopting this structure, when the organometallic complex is applied to a light-emitting element, a light-emitting element with good luminous efficiency and / or reliability can be obtained.

[0134] The ligand included in the organometallic complex of one embodiment of the present invention has a structure in which the benzene ring contained in the benzimidazole skeleton is also fused with a benzene ring. By adopting this structure, the molecular stability can be improved and a light-emitting element with good reliability can be obtained. In addition, an organometallic complex with good luminescence quantum yield can be obtained.

[0135] In addition, when a substituted or unsubstituted aryl group having 6 to 25 carbon atoms is bonded to position 1 of the 1H-naphtho[1,2-d]imidazole skeleton, the molecular stability and sublimation properties are improved compared to the case where a hydrogen or alkyl group is bonded to position 1. Therefore, a light-emitting element with good reliability can be obtained. In addition, when an organic EL element is manufactured by a vacuum evaporation method, an organic compound of one embodiment of the present invention can be appropriately used.

[0136] <Fusion Position of Imidazole Skeleton and Naphthalene Skeleton>

[0137] In addition, the 1H-naphtho[1,2-d]imidazole skeleton contained in the organometallic complex of one embodiment of the present invention can be regarded as a structure in which the imidazole skeleton is fused with a naphthalene skeleton. Here, when the naphthalene skeleton is fused to the a position of the imidazole skeleton, an Ir complex having a structure represented by the following general formula (I-1) can be considered as an example.

[0138] [Chemical formula 19]

[0139]

[0140] In the general formula (I-1), R 1 To R 7 Each independently represents hydrogen, an alkyl group having 1 to 6 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 7 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 25 carbon atoms.

[0141] The structure represented by the general formula (I-1) has a structure in which an imidazole skeleton bonded to Ir and a benzene skeleton bonded to Ir are fused to each other. This structure has a tendency that the quantum yield does not increase. In addition, since the imidazole skeleton bonded to Ir and the benzene skeleton bonded to Ir are fused, it can be predicted that light emission will be presented on the side with a longer wavelength compared to the case where they are not fused. Therefore, it can be predicted that this skeleton is not suitable for blue or green phosphorescent materials that have a particularly large demand for research and development.

[0142] On the other hand, the 1H-naphtho[1,2-d]imidazole skeleton included in the organometallic complex of one embodiment of the present invention has a structure in which a naphthalene skeleton is fused to the d-position of the imidazole skeleton. Here, when a naphthalene skeleton is fused to the d-position of the imidazole skeleton, a 1H-naphtho[1,2-d]imidazole skeleton and a 1H-naphtho[2,1-d]imidazole skeleton can be considered based on the difference in the fusion position. The influence of the difference in these fused carbons on the quantum yield is examined by molecular orbital calculation.

[0143] <Net Charge Calculation Example>

[0144] This calculation example specifically illustrates the lowest triplet excited states (T 1 State) calculation example. The structures of compound-A and compound-B are shown below. In compound-A, the benzene ring of a shown in the structural formula is fused to the side opposite to Ir when viewed from the N (nitrogen) bonded to Ir. On the other hand, in compound-B, the benzene ring of b shown in the structural formula is fused to the same side as Ir when viewed from the N (nitrogen) bonded to Ir. When a 1H-naphtho[2,1-d]imidazole skeleton is used as a ligand of an Ir complex, the benzene ring is fused in the same direction as compound-B.

[0145] [Chemical formula 20]

[0146]

[0147] The molecular orbital calculations were performed using the Gaussian09 program. B3PW91 was used as a general function for structural optimization and vibration calculations. LANL2DZ was used for Ir and 6-311G was used for other elements as basis functions.

[0148] In compound-A, the net charge on Ir in the optimized structure obtained by calculation is 0.30, while in compound-B, the net charge is 0.20.

[0149] The net charge of Ir in Compound-A was significantly higher than that in Compound-B. Metal-Ligand Charge Transfer (MLCT) is the charge transfer between the 5d orbital of Ir and the π orbital of the ligand. ＊ As one of the reasons for the high MLCT property, the high net charge of Ir in the excited state can be cited. It can be seen that the MLCT property in the excited state of compound-A, which is a model of an organic metal complex in one embodiment of the present invention, is higher than that of compound-B. It is known that there is a correlation between the MLCT property and the quantum yield of phosphorescent materials, and it is predicted that the luminescence quantum yield is also high when the MLCT property is high. Therefore, the organic compound in one embodiment of the present invention has a high luminescence quantum yield.

[0150] In compound-B, the benzene ring represented by b in the structural formula exists in the direction that produces steric hindrance with Ir. Therefore, it is predicted that the bonding distance between Ir and N (nitrogen) possessed by the imidazole skeleton in compound-B becomes longer. It can be considered that the net charge on Ir in compound-B becomes smaller as described above. Since the Ir complex having a 1H-naphtho[2,1-d]imidazole skeleton also has a benzene ring represented by b in the structural formula, it can be considered that its net charge is as small as that of compound-B. On the other hand, the benzene ring represented by a in the structural formula possessed by compound-A does not produce steric hindrance with Ir. Therefore, it can be considered that a result in which its net charge is larger than that of compound-B can be obtained.

[0151] Therefore, when considering an organic metal complex having a structure in which an imidazole skeleton is fused with a naphthalene skeleton, an organic metal complex having a good light emission quantum yield can be obtained by using a 1H-naphtho[1,2-d]imidazole skeleton.

[0152] The aryl group having 6 to 25 carbon atoms is preferably a substituted or unsubstituted phenyl group. By adopting this structure, the organometallic complex of one embodiment of the present invention can be synthesized cheaply or easily. Therefore, the general formula (G-1) is preferably a structure represented by the following general formula (G-2).

[0153] [Chemical formula 21]

[0154]

[0155] In the general formula (G-2), R 1 To R 15 Each independently represents hydrogen, an alkyl group having 1 to 6 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 7 carbon atoms, a substituted or unsubstituted aryl group having 6 to 25 carbon atoms, or an electron withdrawing group.

[0156] Furthermore, the organometallic complex according to one embodiment of the present invention has a structure represented by the following general formula (G-3).

[0157] [Chemical formula 22]

[0158]

[0159] In the general formula (G-3), R 11 , R 13 and R 15 Each independently represents hydrogen, an alkyl group having 1 to 6 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 7 carbon atoms, a substituted or unsubstituted aryl group having 6 to 25 carbon atoms, or an electron withdrawing group.

[0160] In the general formulas (G-2) and (G-3), R 11 and R 15At least one of them is preferably an alkyl group having 1 to 6 carbon atoms. Since a material with high sublimability can be realized by adopting this structure, the material utilization efficiency can be improved when a light-emitting element is manufactured by vacuum evaporation. 11 and R 15 The bonded phenyl group is R 11 and R 15 When at least one of the alkyl groups is an alkyl group having 1 to 6 carbon atoms, the steric hindrance of the alkyl group causes the dihedral angle formed by the phenyl group and the 1H-naphtho[1,2-d]imidazole skeleton to become larger. Therefore, the conjugation between the phenyl group and the 1H-naphtho[1,2-d]imidazole skeleton is not easy to diffuse, thereby making the luminous wavelength short-wavelength. In addition, the alkyl group is more preferably a branched alkyl group having 3 to 7 carbon atoms. If it is a branched alkyl group, the above-mentioned effect can be obtained. As the branched alkyl group, isopropyl, isobutyl, tert-butyl, etc. can be cited.

[0161] Therefore, the organometallic complex according to one embodiment of the present invention has a structure represented by the following general formula (G-4).

[0162] [Chemical formula 23]

[0163]

[0164] In the general formula (G-4), R 13 represents hydrogen or an electron-withdrawing group.

[0165] In the general formula (G-4), R 13 When hydrogen is used, the synthesis becomes easier, so it is preferred. 13 When it is an electron-withdrawing group, the LUMO (Lowest Unoccupied Molecular Orbital, also known as the lowest unoccupied molecular orbital) energy level and the HOMO (Highest Occupied Molecular Orbital, also known as the highest occupied molecular orbital) energy level of the organometallic complex can be reduced. Therefore, when the organometallic complex is used as a light-emitting element, the electron injection property can be improved while maintaining the hole injection property, thereby improving the luminous efficiency. In addition, it can be expected that the CT (Charge Transfer) property will be improved and the spectral width will be widened. In this way, a light-emitting element with high color rendering properties can be manufactured.

[0166] Furthermore, the organometallic complex according to one embodiment of the present invention is an organometallic complex represented by General Formula (G-5).

[0167] [Chemical formula 24]

[0168]

[0169] In the general formula (G-5), R 15 It represents hydrogen, an alkyl group having 1 to 6 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 7 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 25 carbon atoms.

[0170] As described above, by introducing a cyano group which is an electron withdrawing group into the 4-position of the phenyl group bonded to the 1-position of 1H-naphtho[1,2-d]imidazole, a light-emitting element with good luminous efficiency can be produced. In addition, a light-emitting element with high color rendering properties can be produced.

[0171] Furthermore, the organometallic complex according to one embodiment of the present invention is an organometallic complex represented by the following general formula (G-6).

[0172] [Chemical formula 25]

[0173]

[0174] In the general formula (G-6), R 1 To R 10 Each independently represents hydrogen, an alkyl group having 1 to 6 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 7 carbon atoms, a substituted or unsubstituted aryl group having 6 to 25 carbon atoms, or an electron withdrawing group, and Ar represents a substituted or unsubstituted aryl group having 6 to 25 carbon atoms.

[0175] The organometallic complex represented by the general formula (G-6) shows a tri-ligand in the organometallic complex represented by the general formula (G-1), wherein the three ligands possessed by the organometallic complex are the same. The tri-ligand organometallic complex has good luminous efficiency and reliability, so it is preferred.

[0176] Furthermore, the organometallic complex according to one embodiment of the present invention is an organometallic complex represented by the following general formula (G-7).

[0177] [Chemical formula 26]

[0178]

[0179] In the general formula (G-7), R 1 To R 15 Each independently represents hydrogen, an alkyl group having 1 to 6 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 7 carbon atoms, a substituted or unsubstituted aryl group having 6 to 25 carbon atoms, or an electron withdrawing group.

[0180] The organometallic complex represented by the general formula (G-7) is a tri-ligand in the organometallic complex represented by the general formula (G-2), wherein the three ligands of the organometallic complex are the same. The tri-ligand organometallic complex has good luminous efficiency and reliability, so it is preferred.

[0181] Furthermore, the organometallic complex according to one embodiment of the present invention is an organometallic complex represented by the following general formula (G-8).

[0182] [Chemical formula 27]

[0183]

[0184] In the general formula (G-8), R 11 , R 13 and R 15 Each independently represents hydrogen, an alkyl group having 1 to 6 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 7 carbon atoms, a substituted or unsubstituted aryl group having 6 to 25 carbon atoms, or an electron withdrawing group.

[0185] The organometallic complex represented by the general formula (G-8) is a tri-ligand in the organometallic complex represented by the general formula (G-3), wherein the three ligands possessed by the organometallic complex are the same. The tri-ligand organometallic complex has good luminous efficiency and reliability, so it is preferred.

[0186] Furthermore, the organometallic complex according to one embodiment of the present invention is an organometallic complex represented by the following general formula (G-9).

[0187] [Chemical formula 28]

[0188]

[0189] In the general formula (G-9), R 13 represents hydrogen or an electron-withdrawing group.

[0190] The organometallic complex represented by the general formula (G-9) represents a tri-ligand in the organometallic complex represented by the general formula (G-4), wherein the three ligands possessed by the organometallic complex are the same. The tri-ligand organometallic complex has good luminous efficiency and reliability, so it is preferred.

[0191] Furthermore, the organometallic complex according to one embodiment of the present invention is an organometallic complex represented by the following general formula (G-10).

[0192] [Chemical formula 29]

[0193]

[0194] In the general formula (G-10), R 15 It represents hydrogen, an alkyl group having 1 to 6 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 7 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 25 carbon atoms.

[0195] The organometallic complex represented by the general formula (G-10) is a triligand of the organometallic complex represented by the general formula (G-5), wherein the three ligands of the organometallic complex are the same. The triligand organometallic complex has good luminous efficiency and reliability, so it is preferred.

[0196] Furthermore, the organometallic complex according to one embodiment of the present invention is an organometallic complex represented by the following general formula (G-11).

[0197] [Chemical formula 30]

[0198]

[0199] In the general formula (G-11), R 1 To R 10 Each independently represents hydrogen, an alkyl group having 1 to 6 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 7 carbon atoms, a substituted or unsubstituted aryl group having 6 to 25 carbon atoms, or an electron withdrawing group, Ar represents a substituted or unsubstituted aryl group having 6 to 25 carbon atoms, L represents a monoanionic ligand, and n represents 1 or 2.

[0200] The organometallic complex represented by the general formula (G-11) is a heterogeneous compound of the organometallic complex represented by the general formula (G-1), and the heterogeneous compound includes two or more ligands. The heterogeneous organometallic complex is preferred because the emission color or sublimation property can be adjusted by selecting the combination of ligands.

[0201] Furthermore, the organometallic complex according to one embodiment of the present invention is an organometallic complex represented by the following general formula (G-12).

[0202] [Chemical formula 31]

[0203]

[0204] In the general formula (G-12), R 1 To R 15 Each independently represents hydrogen, an alkyl group having 1 to 6 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 7 carbon atoms, a substituted or unsubstituted aryl group having 6 to 25 carbon atoms, or an electron withdrawing group, L represents a monoanionic ligand, and n represents 1 or 2.

[0205] The organometallic complex represented by the general formula (G-12) is a heterogeneous compound of the organometallic complex represented by the general formula (G-2), and the heterogeneous compound includes two or more ligands. The heterogeneous organometallic complex is preferred because it can adjust the emission color or sublimation property by selecting the combination of ligands.

[0206] Furthermore, the organometallic complex according to one embodiment of the present invention is an organometallic complex represented by the following general formula (G-13).

[0207] [Chemical formula 32]

[0208]

[0209] In the general formula (G-13), R 11 , R 13 and R 15 Each independently represents hydrogen, an alkyl group having 1 to 6 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 7 carbon atoms, a substituted or unsubstituted aryl group having 6 to 25 carbon atoms, or an electron withdrawing group, L represents a monoanionic ligand, and n represents 1 or 2.

[0210] The organometallic complex represented by the general formula (G-13) is a heterogeneous compound in the organometallic complex represented by the general formula (G-3), and the heterogeneous compound includes two or more ligands. The heterogeneous organometallic complex is preferred because it can adjust the emission color or sublimation property by selecting the combination of ligands.

[0211] Furthermore, the organometallic complex according to one embodiment of the present invention is an organometallic complex represented by the following general formula (G-14).

[0212] [Chemical formula 33]

[0213]

[0214] In the general formula (G-14), R 13 represents hydrogen or an electron-withdrawing group, L represents a monoanionic ligand, and n represents 1 or 2.

[0215] The organometallic complex represented by the general formula (G-14) is a heterogeneous compound of the organometallic complex represented by the general formula (G-4), and the heterogeneous compound includes two or more ligands. The heterogeneous organometallic complex is preferred because it can adjust the emission color or sublimation property by selecting the combination of ligands.

[0216] Furthermore, the organometallic complex according to one embodiment of the present invention is an organometallic complex represented by the following general formula (G-15).

[0217] [Chemical formula 34]

[0218]

[0219] In the general formula (G-15), R 15represents hydrogen, an alkyl group having 1 to 6 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 7 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 25 carbon atoms, L represents a monoanionic ligand, and n represents 1 or 2.

[0220] The organometallic complex represented by the general formula (G-15) is a heterogeneous compound of the organometallic complex represented by the general formula (G-5), and the heterogeneous compound includes two or more ligands. The heterogeneous organometallic complex is preferred because it can adjust the emission color or sublimation property by selecting the combination of ligands.

[0221] In addition, the monoanionic ligand represented by L in the above general formulas (G-11) to (G-15) is preferably a bidentate chelate ligand of a monoanionic ligand containing a β-diketone structure, a bidentate chelate ligand of a monoanionic ligand containing a carboxyl group, a bidentate chelate ligand of a monoanionic ligand containing a phenolic hydroxyl group, or a bidentate chelate ligand of a monoanionic ligand in which both coordinating elements are nitrogen, or a bidentate ligand that forms a metal-carbon bond with iridium due to cyclometallation. Specifically, any one of the following general formulas (L1) to (L9) is preferred.

[0222] [Chemical formula 35]

[0223]

[0224] In the above general formulae (L1) to (L9), R 21 To R 86 Each independently represents the following: hydrogen; a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms; a halo group; a vinyl group; a cyano group; a substituted or unsubstituted haloalkyl group having 1 to 6 carbon atoms; a substituted or unsubstituted alkoxy group having 1 to 6 carbon atoms; a substituted or unsubstituted alkylthio group having 1 to 6 carbon atoms; and a substituted or unsubstituted aryl group having 6 to 13 carbon atoms. In addition, A 1 To A 13 Each independently represents sp bonded to nitrogen or hydrogen 2 Hybridized carbon, or sp with substituents 2 Hybridized carbon, the substituent represents any one of an alkyl group having 1 to 6 carbon atoms, a halo group, a haloalkyl group having 1 to 6 carbon atoms, and a phenyl group.

[0225] Here, although the heterogeneous organometallic complex includes multiple ligands, the HOMO and LUMO of the organometallic complex are preferably distributed in the same ligand. When this structure is adopted, an organometallic complex with particularly good luminous efficiency can be achieved. Therefore, in general formulas (G-11) to (G-15), L is particularly preferably (L8) or (L9). An organometallic complex of one embodiment of the present invention includes a 5-membered ring imidazole skeleton. Therefore, L also preferably has a structure including a 5-membered ring skeleton. By adopting this structure, the HOMO and LUMO of the organometallic complex are easily distributed in the same ligand.

[0226] <Examples of Substituents>

[0227] In the general formulae (G-1) to (G-15), R 1 To R 15 For example, it represents hydrogen, an alkyl group having 1 to 6 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 7 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 25 carbon atoms, or an electron-withdrawing group. Examples of the alkyl group include methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl, n-hexyl, etc. Examples of the cycloalkyl group include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, etc. Examples of the aryl group include phenyl, naphthyl, biphenyl, fluorenyl, spirofluorenyl, etc. Examples of the electron-withdrawing group include halo, cyano, nitro, carbonyl, and haloalkyl. Specific examples of haloalkyl groups include trifluoromethyl, etc. More specifically, examples include groups represented by the following structural formulas (R-1) to (R-43). In particular, halo, cyano, and trifluoromethyl have high electron-withdrawing properties and stability, so they are preferred. In addition, R 1 To R 4 and R 5 To R 13 The basis represented is not limited thereto.

[0228] [Chemical formula 36]

[0229]

[0230] At this time, in R 1 To R 10 When R is hydrogen, the organometallic complex of one embodiment of the present invention can be synthesized simply and inexpensively. The organometallic complex is electrochemically stable and has high reliability, so it is preferred. 1 To R 10When it is a substituent other than hydrogen, the heat resistance of the organometallic complex of one embodiment of the present invention can be improved. When it is an alkyl group or a cycloalkyl group, as in (R-2) to (R-15), the solubility in an organic solvent is improved, thereby facilitating the purification of the organometallic complex of one embodiment of the present invention. As in (R-16), (R-22) to (R-28), (R-31) and (R-32), an aryl group without an alkyl group or a cycloalkyl group is electrochemically stable and has high reliability.

[0231] In addition, in the general formulas (G-1), (G-6) and (G-11), examples of substituted or unsubstituted aryl groups having 6 to 25 carbon atoms include phenyl, naphthyl, biphenyl, fluorenyl, spirofluorenyl and the like. Specifically, groups represented by the following structural formulas (Ar-1) to (Ar-25) can be used. Note that the group represented by Ar is not limited thereto. In addition, it may also have a substituent.

[0232] [Chemical formula 37]

[0233]

[0234] In the above general formulae (L1) to (L9), R 21 To R 86 The following are independently listed: hydrogen; substituted or unsubstituted alkyl having 1 to 6 carbon atoms; halo; vinyl; cyano; substituted or unsubstituted haloalkyl having 1 to 6 carbon atoms; substituted or unsubstituted alkoxy having 1 to 6 carbon atoms; substituted or unsubstituted alkylthio having 1 to 6 carbon atoms; and substituted or unsubstituted aryl having 6 to 13 carbon atoms. Examples of the alkyl group include methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl, and n-hexyl. Examples of the halide group include fluoro, chloro, bromo, and iodo. Examples of the vinyl group include vinyl and vinyl anhydride. Examples of the halide alkyl group include trifluoromethyl, pentafluoroethyl, and trichloromethyl. Examples of the alkoxy group include methoxy, ethoxy, and phenoxy. Examples of the alkylthio group include propylthio and butylthio. Examples of the aryl group include phenyl, naphthyl, biphenyl, and fluorenyl. More specifically, examples include groups represented by the following structural formulas (R-50) to (R-95). Note that R 21 To R 86 The basis represented is not limited thereto.

[0235] [Chemical formula 38]

[0236]

[0237] In the above general formulae (G1) to (G15), Ar, R 1 To R 15and R 21 To R 86 When there is a substituent, examples of the substituent include an alkyl group having 1 to 6 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 7 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 25 carbon atoms. Examples of the alkyl group include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a tert-butyl group, and a n-hexyl group, examples of the cycloalkyl group include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, and a cyclohexyl group, and examples of the aryl group include a phenyl group, a naphthyl group, and a fluorenyl group.

[0238] <Specific Examples of Compounds>

[0239] As specific structures of the compounds represented by general formulae (G-1) to (G-15), organic metal complexes represented by the following structural formulae (100) to (123) and structural formulae (200) to (223) can be cited. Note that the organic metal complexes represented by general formulae (G-1) to (G-15) are not limited to the following examples.

[0240] [Chemical formula 39]

[0241]

[0242] [Chemical formula 40]

[0243]

[0244] [Chemical formula 41]

[0245]

[0246] [Chemical formula 42]

[0247]

[0248] [Chemical formula 43]

[0249]

[0250] [Chemical formula 44]

[0251]

[0252] [Chemical formula 45]

[0253]

[0254] The organometallic complex in one embodiment of the present invention can be formed by a vapor deposition method (including a vacuum vapor deposition method), an inkjet method, a coating method, a gravure printing method, or the like.

[0255] In addition, this embodiment mode can be combined with other embodiment modes as appropriate.

[0256] (Implementation Method 2)

[0257] In this embodiment, an example of a method for synthesizing an organometallic complex according to one embodiment of the present invention is described.

[0258] 《Method for synthesizing 1H-naphtho[1,2-d]imidazole derivatives represented by general formula (g-1)》

[0259] An example of a method for synthesizing a 1H-naphtho[1,2-d]imidazole derivative represented by the following general formula (g-1) is described. An organic metal complex of one embodiment of the present invention having a structure represented by the general formula (G-1) contains a 1H-naphtho[1,2-d]imidazole derivative represented by the general formula (g-1) as a ligand. Therefore, by synthesizing an Ir complex using a 1H-naphtho[1,2-d]imidazole derivative represented by the general formula (g-1), an organic metal complex of one embodiment of the present invention can be synthesized as described later.

[0260] [Chemical formula 46]

[0261]

[0262] In the general formula (g-1), R 1 To R 10 Each independently represents hydrogen, an alkyl group having 1 to 6 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 7 carbon atoms, a substituted or unsubstituted aryl group having 6 to 25 carbon atoms, or an electron withdrawing group, and Ar represents a substituted or unsubstituted aryl group having 6 to 25 carbon atoms.

[0263] As shown in the following scheme (S-1), a 1H-naphtho[1,2-d]imidazole derivative represented by the general formula (g-1) can be obtained by reacting an aromatic aldehyde compound or an aromatic carboxylic acid chloride (M1) with an o-naphthyldiamine derivative (M2) in which Ar is substituted at the N position.

[0264] [Chemical formula 47]

[0265]

[0266] In Scheme (S-1) R 1 To R 10 Each independently represents hydrogen, an alkyl group having 1 to 6 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 7 carbon atoms, a substituted or unsubstituted aryl group having 6 to 25 carbon atoms, or an electron withdrawing group, and Ar represents a substituted or unsubstituted aryl group having 6 to 25 carbon atoms.

[0267] <Method for synthesizing the organometallic complex represented by the general formula (G-6)>

[0268] Next, an example of a method for synthesizing an organometallic complex represented by the general formula (G-6) among methods for synthesizing an organometallic complex having a structure represented by the general formula (G-1) is described.

[0269] As shown in the following scheme (S-2), a 1H-naphthyl[1,2-d]imidazole derivative represented by the general formula (g-1) and an iridium metal compound containing a halogen (iridium chloride hydrate, ammonium hexachloroiridate, etc.) or an iridium organometallic complex compound (acetylacetonate complex, diethyl sulfide complex, etc.) are then heated to obtain an organometallic complex having a structure represented by the general formula (G-6). In addition, this heating step can also be performed after dissolving the 1H-naphthyl[1,2-d]imidazole derivative represented by the general formula (g-1), the iridium metal compound containing a halogen, or the iridium organometallic complex compound in an alcohol solvent (glycerol, ethylene glycol, 2-methoxyethanol, 2-ethoxyethanol, etc.). In addition, in scheme (S-2), R 1 To R 10 Each independently represents hydrogen, an alkyl group having 1 to 6 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 7 carbon atoms, a substituted or unsubstituted aryl group having 6 to 25 carbon atoms, or an electron withdrawing group, and Ar represents a substituted or unsubstituted aryl group having 6 to 25 carbon atoms.

[0270] [Chemical formula 48]

[0271]

[0272] Note that the synthesis method of the organometallic complex of the present invention is not limited to Scheme (S-2).

[0273] <Method for synthesizing the organometallic complex represented by the general formula (G-11)>

[0274] Next, an example of a method for synthesizing an organometallic complex represented by the general formula (G-11) among methods for synthesizing an organometallic complex including a structure represented by the general formula (G-1) is described.

[0275] As shown in the following scheme (S-3), a 1H-naphthyl[1,2-d]imidazole derivative represented by the general formula (g-1) obtained by the above synthesis scheme (g-1) or L and an iridium compound containing a halogen (iridium chloride, iridium bromide, iridium iodide, etc.) are heated without using a solvent, using an alcohol solvent (glycerol, ethylene glycol, 2-methoxyethanol, 2-ethoxyethanol, etc.) alone, or using a mixed solvent of one or more alcohol solvents and water, and under an inert gas atmosphere, thereby obtaining a binuclear complex (P1) of a 1H-naphthyl[1,2-d]imidazole derivative or a binuclear complex (P2) containing a monoanionic bidentate ligand. Both the binuclear complex (P1) and the binuclear complex (P2) are novel organic metal complexes having a structure cross-linked by a halogen. In addition, in scheme (S-3), X represents a halogen atom, and R 1 To R 10 Each independently represents hydrogen, an alkyl group having 1 to 6 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 7 carbon atoms, a substituted or unsubstituted aryl group having 6 to 25 carbon atoms, or an electron withdrawing group, and Ar represents a substituted or unsubstituted aryl group having 6 to 25 carbon atoms.

[0276] [Chemical formula 49]

[0277]

[0278] Furthermore, as shown in the following scheme (S-4), the binuclear complex (P1) or (P2) obtained by the above-mentioned synthesis scheme (S-3) is reacted with a 1H-naphtho[1,2-d]imidazole derivative or L represented by the general formula (g-1) in an inert gas atmosphere to obtain an organic metal complex of one embodiment of the present invention represented by the general formula (G-11). Here, by irradiating the obtained organic metal complex with light or heating it to cause it to react, isomers such as geometric isomers and optical isomers can also be obtained, which are also organic metal complexes of one embodiment of the present invention represented by the general formula (G-11). In addition, in scheme (S-4), X represents a halogen atom, and R 1 To R 10 Each independently represents hydrogen, an alkyl group having 1 to 6 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 7 carbon atoms, a substituted or unsubstituted aryl group having 6 to 25 carbon atoms, or an electron withdrawing group, and Ar represents a substituted or unsubstituted aryl group having 6 to 25 carbon atoms.

[0279] [Chemical formula 50]

[0280]

[0281] Note that the method for synthesizing the organometallic complex of the present invention is not limited to Schemes (S-3) and (S-4).

[0282] (Implementation 3)

[0283] In this embodiment, a light-emitting element including an organometallic complex which is one embodiment of the present invention is described with reference to FIG. 1 .

[0284] <Structural Example 1 of Light Emitting Element>

[0285] First, we will refer to Figure 1A , Figure 1B , Figure 1C The structure of a light-emitting element according to one embodiment of the present invention will be described.

[0286] Figure 1A It is a schematic cross-sectional view of a light emitting element 150 according to one embodiment of the present invention.

[0287] The light-emitting element 150 includes a pair of electrodes (electrode 101 and electrode 102 ) and includes an EL layer 100 provided between the pair of electrodes. The EL layer 100 includes at least a light-emitting layer 140 .

[0288] also, Figure 1A The EL layer 100 shown includes functional layers such as a hole injection layer 111 , a hole transport layer 112 , an electron transport layer 118 , and an electron injection layer 119 in addition to the light-emitting layer 140 .

[0289] Note that although the electrode 101 of a pair of electrodes is described as an anode and the electrode 102 is described as a cathode in this embodiment, the structure of the light-emitting element 150 is not limited to this. That is, the electrode 101 may be used as a cathode and the electrode 102 may be used as an anode, and the layers between the electrodes may be stacked in reverse order. In other words, the hole injection layer 111, the hole transport layer 112, the light-emitting layer 140, the electron transport layer 118, and the electron injection layer 119 may be stacked in order from the anode side.

[0290] Note that the structure of the EL layer 100 is not limited to Figure 1A The structure shown may include at least one selected from the group consisting of the hole injection layer 111, the hole transport layer 112, the electron transport layer 118, and the electron injection layer 119. Alternatively, the EL layer 100 may include a functional layer having the following functions: lowering the injection barrier of holes or electrons; improving the transportability of holes or electrons; hindering the transportability of holes or electrons; or suppressing the quenching phenomenon caused by the electrode. The functional layer may be a single layer or a structure having a plurality of layers stacked.

[0291] In the light-emitting element 150, any layer in the EL layer 100 may contain an organic metal complex of one embodiment of the present invention. In addition, the organic metal complex has a good quantum yield. Therefore, by using the organic metal complex as a guest material of the light-emitting layer 140, a light-emitting element with good luminous efficiency can be obtained.

[0292] Figure 1B It is shown Figure 1A FIG. 1 is a schematic cross-sectional view of an example of the light emitting layer 140 shown. Figure 1B The light-emitting layer 140 shown includes a host material 141 and a guest material 142. The host material 141 may be composed of a single organic compound or may be a co-host material including an organic compound 141_1 and an organic compound 141_2. An organometallic complex according to one embodiment of the present invention can be appropriately used as the guest material 142.

[0293] As the guest material 142, a light-emitting organic material may be used. As the light-emitting organic material, a material capable of emitting fluorescence (hereinafter, also referred to as a fluorescent material) or a material capable of emitting phosphorescence (hereinafter, also referred to as a phosphorescent compound) may be cited. Phosphorescent materials are preferably used due to their high luminous efficiency. Thus, an organic metal complex of one embodiment of the present invention may be appropriately used. The following describes a structure in which a phosphorescent material is used as the guest material 142. Note that the guest material 142 may also be referred to as a phosphorescent material.

[0294] exist Figure 1B In the case where the light-emitting layer includes two main materials (co-host type) of organic compound 141_1 and organic compound 141_2, electron transport material and hole transport material are usually used as two main materials. By using this structure, the hole injection barrier between the hole transport layer 112 and the light-emitting layer 140 and the electron injection barrier between the electron transport layer 118 and the light-emitting layer 140 can be reduced, thereby reducing the driving voltage, so it is preferred.

[0295] <Light Emission Mechanism of Light Emitting Element>

[0296] Next, the light emitting mechanism of the light emitting layer 140 will be described below.

[0297] The organic compound 141_1 and the organic compound 141_2 included in the host material 141 in the light-emitting layer 140 can form an exciplex. Hereinafter, the case where the organic compound 141_1 and the organic compound 141_2 form an exciplex will be described.

[0298] Figure 1CThe energy level correlation of the organic compound 141_1, the organic compound 141_2, and the guest material 142 in the light-emitting layer 140 is shown below. Figure 1C In the following description, the organic compound 141_1 is an electron-transporting material and the organic compound 141_2 is a hole-transporting material.

[0299] Host (141_1): Organic compound 141_1 (host material)

[0300] Host (141_2): Organic compound 141_2 (host material)

[0301] Guest (142): Guest material 142 (phosphorescent compound)

[0302] ·S PH1 : S1 level of organic compound 141_1 (host material)

[0303] ·T PH1 : T1 level of organic compound 141_1 (host material)

[0304] ·S PH2 : S1 level of organic compound 141_2 (host material)

[0305] ·T PH2 : T1 level of organic compound 141_2 (host material)

[0306] ·S PG : S1 level of guest material 142 (phosphorescent compound)

[0307] ·T PG : T1 level of guest material 142 (phosphorescent compound)

[0308] ·S PE : S1 energy level of the exciplex

[0309] ·T PE : T1 energy level of the exciplex

[0310] The organic compound 141_1 and the organic compound 141_2 form an exciplex, and the S1 energy level (S PE ) and T1 level (T PE ) become adjacent energy levels (refer to Figure 1C Path E 1 ).

[0311] When the organic compound 141_1 receives electrons and the organic compound 141_2 receives holes, an exciplex is rapidly formed. Alternatively, when one of them becomes excited, an exciplex is rapidly formed by interacting with the other. Thus, most of the excitons in the light-emitting layer 140 exist as exciplexes. The excitation energy level (S PE or T PE ) is lower than the S1 level (S PH1 and S PH2 ) is low, the excited state of the host material 141 can be formed with lower excitation energy. Thus, the driving voltage of the light-emitting element can be reduced. Note that an exciplex can be formed by the organic compound 141_1 receiving a hole and the organic compound 141_2 receiving an electron.

[0312] Then, by exciplex (S PE ) and (T PE ) is transferred to the T1 level of the guest material 142 (phosphorescent compound) to obtain light emission (refer to Figure 1C Path E 2 、E 3 ).

[0313] The T1 energy level of the exciplex (T PE ) is preferably higher than the T1 energy level (T PG ) is high. Thus, the singlet excitation energy and triplet excitation energy of the generated exciplex can be increased from the S1 level (S PE ) and T1 level (T PE ) is transferred to the T1 energy level (T PG ).

[0314] In order to efficiently transfer the excitation energy from the exciplex to the guest material 142, the T1 energy level (T PE ) is preferably equal to or lower than the T1 level (T PH1 and T PH2 ). Thus, quenching of triplet excitation energy of the exciplex by each organic compound (the organic compound 141_1 and the organic compound 141_2) is unlikely to occur, and energy transfer from the exciplex to the guest material 142 occurs efficiently.

[0315] When the combination of the organic compound 141_1 and the organic compound 141_2 is a combination of a compound having a hole transport property and a compound having an electron transport property, the carrier balance can be easily controlled by adjusting the mixing ratio. Specifically, the weight ratio of the compound having a hole transport property: the compound having an electron transport property is preferably in the range of 1:9 to 9:1. In addition, by adopting this structure, the carrier balance is easily controlled, thereby also easily controlling the carrier recombination region.

[0316] In this specification, the above-mentioned path E may be referred to as 2 、E 3 The process of exciplex-triplet energy transfer is called ExTET (Exciplex-Triplet Energy Transfer). In other words, in the light-emitting layer 140, the excitation energy is supplied from the exciplex to the guest material 142. In this case, it is not necessary to transfer the energy from T PE To S PE The efficiency of anti-system crossing and the PE The quantum yield of light emission is high, so more materials can be selected. By using ExTET, a light-emitting element with high light emission efficiency, low driving voltage and high reliability can be obtained.

[0317] The combination of the organic compound 141_1 and the organic compound 141_2 may be any combination as long as they can form an exciplex. Preferably, the HOMO level of one is lower than that of the other, and the LUMO level of one is lower than that of the other.

[0318] <Materials>

[0319] Next, components of a light-emitting element according to one embodiment of the present invention will be described in detail.

[0320] Luminous Layer

[0321] In the light-emitting layer 140, the weight ratio of the host material 141 is the highest, and the guest material 142 is dispersed in the host material 141. When the guest material 142 is a phosphorescent compound, the T1 energy level of the host material 141 (organic compound 141_1 and organic compound 141_2) of the light-emitting layer 140 is preferably higher than the T1 energy level of the guest material (guest material 142) of the light-emitting layer 140.

[0322] The organic compound 141_1 is preferably a compound having a nitrogen-containing six-membered heteroaromatic ring skeleton. As other specific examples, compounds having a pyridine skeleton, a diazine skeleton (pyrazine skeleton, a pyrimidine skeleton and a pyridazine skeleton) and a triazine skeleton can be cited. As the above-mentioned compound containing a basic nitrogen-containing heteroaromatic ring skeleton, for example, compounds such as pyridine derivatives, bipyridine derivatives, pyrimidine derivatives, triazine derivatives, quinoxaline derivatives, dibenzoquinoxaline derivatives, phenanthroline derivatives, and purine compounds can be cited. In addition, as the organic compound 141_1, a material (electron transport material) with a higher electron transport property than a hole transport property can be used, preferably a material with a 1×10 -6 cm 2 / Vs or above.

[0323] Specifically, for example, heteroaromatic ring compounds having a pyridine skeleton such as bathophenanthroline (abbreviated as Bphen) and bathocuproin (abbreviated as BCP) can be used; 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-[3'-(9H-carbazole-9-yl)biphenyl-3-yl]dibenzo[f,h]quinoxaline (abbreviated as 2mDBTBPDBq-II), 2mCzBPDBq), 2-[4-(3,6-diphenyl-9H-carbazole-9-yl)phenyl]dibenzo[f,h]quinoxaline (abbreviated as: 2CzPDBq-III), 7-[3-(dibenzothiophen-4-yl)phenyl]dibenzo[f,h]quinoxaline (abbreviated as: 7mDBTPDBq-II), 6-[3-(dibenzothiophen-4-yl)phenyl]dibenzo[f,h]quinoxaline (abbreviated as: 6mDBTPDBq-II), (2-[3-(3,9'-biphenyl-9H-carbazole-9-yl)phenyl]dibenzo[f,h ]quinoxaline) (abbreviation: 2mCzCzPDBq), 4,6-bis[3-(phenanthrene-9-yl)phenyl]pyrimidine (abbreviation: 4,6mPnP2Pm), 4,6-bis[3-(4-dibenzothienyl)phenyl]pyrimidine (abbreviation: 4,6mDBTP2Pm-II), 4,6-bis[3-(9H-carbazole-9-yl)phenyl]pyrimidine (abbreviation: 4,6mCzP2Pm), etc.; 2-{4-[3-(N-phenyl-9H-carbazole-3-yl)-9H-carbazole-9-yl]phenyl}-4, Heteroaromatic ring compounds having a triazine skeleton, such as 6-diphenyl-1,3,5-triazine (abbreviation: PCCzPTzn), 9-[3-(4,6-diphenyl-1,3,5-triazine-2-yl)phenyl]-9'-phenyl-2,3'-bi-9H-carbazole (abbreviation: mPCCzPTzn-02); Heteroaromatic ring compounds having a pyridine skeleton, such as 3,5-bis[3-(9H-carbazole-9-yl)phenyl]pyridine (abbreviation: 35DCzPPy), 1,3,5-tris[3-(3-pyridyl)phenyl]benzene (abbreviation: TmPyPB). Among the above-mentioned heteroaromatic ring compounds, heteroaromatic ring compounds having a triazine skeleton, a diazine (pyrimidine, pyrazine, pyridazine) skeleton or a pyridine skeleton are stable and have high reliability, so they are preferred. Heteroaromatic ring compounds having this skeleton have high electron transport properties and also contribute to the reduction of driving voltage.In addition, polymer compounds such as poly(2,5-pyridinediyl) (abbreviated as PPy), poly[(9,9-dihexylfluorene-2,7-diyl)-co-(pyridine-3,5-diyl)] (abbreviated as PF-Py), and poly[(9,9-dioctylfluorene-2,7-diyl)-co-(2,2'-bipyridine-6,6'-diyl)] (abbreviated as PF-BPy) can also be used. The substances described here mainly have 1×10. -6 cm 2 Note that any substance other than the above substances may be used as long as the substance has a higher electron-transporting property than a hole-transporting property.

[0324] As the organic compound 141_2, a compound having a nitrogen-containing five-membered heteroaromatic ring skeleton or a tertiary amine skeleton is preferably used. Specifically, a compound having a pyrrole skeleton or an aromatic amine skeleton can be cited. For example, indole derivatives, carbazole derivatives, triarylamine derivatives, etc. can be cited. In addition, as the nitrogen-containing five-membered heteroaromatic ring skeleton, an imidazole skeleton, a triazole skeleton, and a tetrazole skeleton can be cited. In addition, as the organic compound 141_2, a material having a hole transport property higher than an electron transport property (hole transport material) can be used, preferably a material having a 1×10 -6 cm 2 The hole transport material may be a polymer compound.

[0325] As materials with high hole transport properties, specifically, as aromatic amine compounds, there can be mentioned N,N'-di(p-tolyl)-N,N'-diphenyl-p-phenylenediamine (abbreviation: DTDPPA), 4,4'-bis[N-(4-diphenylaminophenyl)-N-phenylamino]biphenyl (abbreviation: DPAB), N,N'-bis{4-[bis(3-methylphenyl)amino]phenyl}-N,N'-diphenyl-(1,1'-biphenyl)-4,4'-diamine (abbreviation: DNTPD), 1,3,5-tris[N-(4-diphenylaminophenyl)-N-phenylamino]benzene (abbreviation: DPA3B), etc.

[0326] In addition, specific examples of carbazole derivatives include 3-[N-(4-diphenylaminophenyl)-N-phenylamino]-9-phenylcarbazole (abbreviated as PCzDPA1), 3,6-bis[N-(4-diphenylaminophenyl)-N-phenylamino]-9-phenylcarbazole (abbreviated as PCzDPA2), 3,6-bis[N-(4-diphenylaminophenyl)-N-(1-naphthyl)amino]-9-phenylcarbazole (abbreviated as PCzDPA2), and 3,6-bis[N-(4-diphenylaminophenyl)-N-(1-naphthyl)amino]-9-phenylcarbazole (abbreviated as PCzDPA1). CzTPN2), 3-[N-(9-phenylcarbazole-3-yl)-N-phenylamino]-9-phenylcarbazole (abbreviated as: PCzPCA1), 3,6-bis[N-(9-phenylcarbazole-3-yl)-N-phenylamino]-9-phenylcarbazole (abbreviated as: PCzPCA2), 3-[N-(1-naphthyl)-N-(9-phenylcarbazole-3-yl)amino]-9-phenylcarbazole (abbreviated as: PCzPCN1), etc.

[0327] In addition, examples of carbazole derivatives include 4,4'-di(N-carbazolyl)biphenyl (abbreviation: CBP), 1,3,5-tri[4-(N-carbazolyl)phenyl]benzene (abbreviation: TCPB), 9-[4-(10-phenyl-9-anthracenyl)phenyl]-9H-carbazole (abbreviation: CzPA), and 1,4-bis[4-(N-carbazolyl)phenyl]-2,3,5,6-tetraphenylbenzene.

[0328] In addition, N,N-diphenyl-9-[4-(10-phenyl-9-anthracenyl)phenyl]-9H-carbazole-3-amine (abbreviation: CzA1PA), 4-(10-phenyl-9-anthracenyl)triphenylamine (abbreviation: DPhPA), 4-(9H-carbazole-9-yl)-4'-(10-phenyl-9-anthracenyl)triphenylamine (abbreviation: YGAPA), N,9-diphenyl-N-[4-(10-phenyl-9-anthracenyl)phenyl]-9H-carbazole-3-amine (abbreviation: PCAPA), N,9-diphenyl-N-{4-[4-(10-phenyl-9 -anthryl)phenyl]phenyl}-9H-carbazole-3-amine (abbreviation: PCAPBA), N,9-diphenyl-N-(9,10-diphenyl-2-anthryl)-9H-carbazole-3-amine (abbreviation: 2PCAPA), 9-phenyl-3-[4-(10-phenyl-9-anthryl)phenyl]-9H-carbazole (abbreviation: PCzPA), 3,6-diphenyl-9-[4-(10-phenyl-9-anthryl)phenyl]-9H-carbazole (abbreviation: DPCzPA), N,N,N',N',N",N",N"',N"'-octaphenyldibenzo[g,p] (chrysene)-2,7,10,15-tetramine (abbreviation: DBC1), etc.

[0329] In addition, high molecular weight compounds such as poly(N-vinylcarbazole) (abbreviation: PVK), poly(4-vinyltriphenylamine) (abbreviation: PVTPA), poly[N-(4-{N'-[4-(4-diphenylamino)phenyl]phenyl-N'-phenylamino}phenyl)methacrylamide] (abbreviation: PTPDMA), and poly[N,N'-bis(4-butylphenyl)-N,N'-bis(phenyl)benzidine] (abbreviation: Poly-TPD) can also be used.

[0330] In addition, as a material with high hole transport properties, for example, 4,4'-bis[N-(1-naphthyl)-N-phenylamino]biphenyl (abbreviated as: NPB or α-NPD), N,N'-bis(3-methylphenyl)-N,N'-diphenyl-[1,1'-biphenyl]-4,4'-diamine (abbreviated as: TPD), 4,4',4"-tri(carbazol-9-yl)triphenylamine (abbreviated as: TCTA), 4,4',4"-tri[N-(1-naphthyl)-N-phenylamino]triphenylamine (abbreviated as: 1'-TNATA), 4,4',4"-tri(N,N-diphenylamino)triphenylamine (abbreviated as: TDATA), 4,4',4"-tri[N-(3-methylphenyl)-N-phenylamino]triphenylamine amine (abbreviation: MTDATA), 4,4'-bis[N-(spiro-9,9'-difluoren-2-yl)-N-phenylamino]biphenyl (abbreviation: BSPB), 4-phenyl-4'-(9-phenylfluoren-9-yl)triphenylamine (abbreviation: BPAFLP), 4-phenyl-3'-(9-phenylfluoren-9-yl)triphenylamine (abbreviation: mBPAFLP), 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), N-(9,9-dimethyl-2-diphenylamino-9H-fluoren-7-yl)diphenylamine amine (abbreviation: DPNF), 2-[N-(4-diphenylaminophenyl)-N-phenylamino]spiro-9,9'-difluorene (abbreviation: DPASF), 4-phenyl-4'-(9-phenyl-9H-carbazole-3-yl)triphenylamine (abbreviation: PCBA1BP), 4,4'-diphenyl-4"-(9-phenyl-9H-carbazole-3-yl)triphenylamine (abbreviation: PCBBi1BP), 4-(1-naphthyl)-4'-(9-phenyl-9H-carbazole-3-yl)triphenylamine (abbreviation: PCBANB), 4,4'-di(1-naphthyl)-4"-(9-phenyl-9H-carbazole-3-yl)triphenylamine (abbreviation: PCNBB), 4-phenyldiphenyl-(9-phenyl-9H- carbazole-3-yl)amine (abbreviation: PCA1BP), N,N'-bis(9-phenylcarbazole-3-yl)-N,N'-diphenylbenzene-1,3-diamine (abbreviation: PCA2B), N,N',N"-triphenyl-N,N',N"-tri(9-phenylcarbazole-3-yl)benzene-1,3,5-triamine (abbreviation: PCA3B), N-(4-biphenyl)-N-(9,9-dimethyl-9H-fluoren-2-yl)-9-phenyl-9H-carbazole-3-amine (abbreviation: PCBiF), N-(1,1'-biphenyl-4-yl)-N-[4-(9-phenyl-9H-carbazole-3-yl)phenyl]-9,9-dimethyl-9H-fluoren-2-amine (abbreviation: PCBBiF), 9,9-dimethyl-N-phenyl-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]fluoren-2-amine (abbreviation: PCBAF), N-phenyl-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]spiro-9,9'-difluoren-2-amine (abbreviation: PCBASF), 2-[N-(9-phenylcarbazol-3-yl)-N-phenylamino]spiro-9,9'-difluoren-2-amine (abbreviation: PCASF), 2, Aromatic amine compounds such as 7-bis[N-(4-diphenylaminophenyl)-N-phenylamino]spiro-9,9'-difluorene (abbreviation: DPA2SF), N-[4-(9H-carbazole-9-yl)phenyl]-N-(4-phenyl)phenylaniline (abbreviation: YGA1BP), N,N'-bis[4-(carbazole-9-yl)phenyl]-N,N'-diphenyl-9,9-dimethylfluorene-2,7-diamine (abbreviation: YGA2F), etc. In addition, amine compounds and carbazole compounds such as 3-[4-(1-naphthyl)-phenyl]-9-phenyl-9H-carbazole (abbreviated as PCPN), 3-[4-(9-phenanthrenyl)-phenyl]-9-phenyl-9H-carbazole (abbreviated as PCPPn), 3,3'-bis(9-phenyl-9H-carbazole) (abbreviated as PCCP), 1,3-bis(N-carbazolyl)benzene (abbreviated as mCP), 3,6-bis(3,5-diphenylphenyl)-9-phenylcarbazole (abbreviated as CzTP), 3,6-bis(9H-carbazole-9-yl)-9-phenyl-9H-carbazole (abbreviated as PhCzGI), and 2,8-bis(9H-carbazole-9-yl)-dibenzothiophene (abbreviated as Cz2DBT) can also be used. Among the above compounds, compounds having a pyrrole skeleton or an aromatic amine skeleton are preferred because they are stable and have good reliability. In addition, the compound having the above skeleton has high hole transport properties, which also contributes to the reduction of driving voltage.

[0331] In addition, as the organic compound 141_2, a compound having a nitrogen-containing five-membered heteroaromatic ring skeleton such as an imidazole skeleton, a triazole skeleton and a tetrazole skeleton can be used. Specifically, for example, 3-(4-biphenyl)-4-phenyl-5-(4-tert-butylphenyl)-1,2,4-triazole (abbreviated as: TAZ), 9-[4-(4,5-diphenyl-4H-1,2,4-triazol-3-yl)phenyl]-9H-carbazole (abbreviated as: CzTAZ1), 2,2',2"-(1,3,5-benzenetriyl)tris(1-phenyl-1H-benzimidazole) (abbreviated as: TPBI), 2-[3-(dibenzothiophene-4-yl)phenyl]-1-phenyl-1H-benzimidazole (abbreviated as: mDBTBIm-II), etc. can be used.

[0332] In the light-emitting layer 140, an organic metal complex of one embodiment of the present invention can be appropriately used as a guest material 142. Since the quantum yield of the organic metal complex of one embodiment of the present invention is high, a light-emitting element with good light-emitting efficiency can be obtained. In addition, when the light-emitting element includes a plurality of light-emitting units as in the light-emitting element 250 described below, it is preferred to use an organic compound of one embodiment of the present invention for the light-emitting layer of one light-emitting unit. Although there is no particular limitation on the guest material used for the other light-emitting units, anthracene derivatives, tetracene derivatives, Examples of the chrysene derivatives, phenanthrene derivatives, pyrene derivatives, perylene derivatives, stilbene derivatives, acridone derivatives, coumarin derivatives, phenoxazine derivatives, and phenothiazine derivatives include the following.

[0333] Specifically, examples of the material include 5,6-bis[4-(10-phenyl-9-anthracenyl)phenyl]-2,2'-bipyridine (abbreviated as PAP2BPy), 5,6-bis[4'-(10-phenyl-9-anthracenyl)biphenyl-4-yl]-2,2'-bipyridine (abbreviated as PAPP2BPy), N,N'-diphenyl-N,N'-bis[4-(9-phenyl-9H-fluorene-9-yl)phenyl]pyrene-1,6-diamine (abbreviated as 1,6FLPAPrn), N,N'-bis(3-methylphenyl)-N,N'-bis[3-(9-phenyl-9H-fluorene-9-yl)phenyl]pyrene- 1,6-diamine (abbreviation: 1,6mMemFLPAPrn), N,N'-bis[4-(9-phenyl-9H-fluoren-9-yl)phenyl]-N,N'-bis(4-tert-butylphenyl)pyrene-1,6-diamine (abbreviation: 1,6tBu-FLPAPrn), N,N'-diphenyl-N,N'-bis[4-(9-phenyl-9H-fluoren-9-yl)phenyl]-3,8-dicyclohexylpyrene-1,6-diamine (abbreviation: ch-1,6FLPAPrn), N,N'-bis[4-(9H-carbazol-9-yl)phenyl]-N,N'-diphenylstilbene-4,4'-diamine (abbreviation: YGA2S), 4-(9H-carbazole-9-yl)-4'-(10-phenyl-9-anthracenyl)triphenylamine (abbreviated as: YGAPA), 4-(9H-carbazole-9-yl)-4'-(9,10-diphenyl-2-anthracenyl)triphenylamine (abbreviated as: 2YGAPPA), N,9-diphenyl-N-[4-(10-phenyl-9-anthracenyl)phenyl]-9H-carbazole-3-amine (abbreviated as: PCAPA), perylene, 2,5,8,11-tetra(tert-butyl)perylene (abbreviated as: TBP), 4-(10-phenyl-9-anthracenyl)-4'-(9-phenyl-9H-carbazole-3-yl)triphenylamine (abbreviated as: P CBAPA), N,N"-(2-tert-butylanthracene-9,10-diyldi-4,1-phenylene)bis[N,N',N'-triphenyl-1,4-phenylenediamine] (abbreviated as DPABPA), N,9-diphenyl-N-[4-(9,10-diphenyl-2-anthracenyl)phenyl]-9H-carbazole-3-amine (abbreviated as 2PCAPPA), N-[4-(9,10-diphenyl-2-anthracenyl)phenyl]-N,N',N'-triphenyl-1,4-phenylenediamine (abbreviated as 2DPAPPA), N,N,N',N',N",N",N"',N"'-octaphenyldibenzo[g,p] (chrysene)-2,7,10,15-tetraamine (abbreviated as DBC1), coumarin 30, 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 (abbreviated as 2DPAPA), N-[9,10-bis(1,1'-biphenyl-2-yl)-2-anthracenyl]-N,N',N'-triphenyl-1,4-phenylenediamine (abbreviated as 2DPAPA), 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), coumarin 6, coumarin 545T, N,N'-diphenylquinacridone (abbreviation: DPQd), rubrene, 2,8-di-tert-butyl-5,11-bis(4-tert-butylphenyl)-6,12-diphenylnaphthacene (abbreviation: TBRb), Nile Red, 5,12-bis(1,1'-biphenyl-4-yl)-6,11-diphenylnaphthacene (abbreviation: BPT), 2-(2-{2-[4-(dimethyl 2-{2-methyl-6-[2-(2,3,6,7-tetrahydro-1H,5H-benzo[ij]quinolizin-9-yl)vinyl]-4H-pyran-4-ylidene}malononitrile (abbreviation: DCM2), N,N,N',N'-tetrakis(4-methylphenyl)naphthocene-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), 2-{2-isopropyl-6-[2-(1,1,7,7-tetramethyl- 2,3,6,7-tetrahydro-1H,5H-benzo[ij]quinolizin-9-yl)vinyl]-4H-pyran-4-ylidene}malononitrile (abbreviation: DCJTI), 2-{2-tert-butyl-6-[2-(1,1,7,7-tetramethyl-2,3,6,7-tetrahydro-1H,5H-benzo[ij]quinolizin-9-yl)vinyl]-4H-pyran-4-ylidene}malononitrile (abbreviation: DCJTB), 2-(2,6-bis{2-[4-(dimethylamino)phenyl]vinyl}-4H-pyran-4-ylidene)malononitrile (abbreviation: BisDCM), 2-{2,6-bis[2-(8-methoxy-1,1,7,7-tetramethyl-2,3,6,7-tetrahydro-1H,5H-benzo[ij]quinolizin-9-yl)vinyl]-4H-pyran-4-ylidene}malononitrile (abbreviation: DCJTB),5H-benzo[ij]quinolizin-9-yl)vinyl]-4H-pyran-4-ylidene}malononitrile (abbreviated as: BisDCJTM), 5,10,15,20-tetraphenylbisbenzo[5,6]indeno[1,2,3-cd:1',2',3'-lm]perylene, etc.

[0334] As phosphorescent compounds that can be used as guest materials, iridium, rhodium, platinum organic metal complexes or metal complexes can be cited, among which organic iridium complexes, such as iridium ortho-metal complexes, are preferred. As ortho-metallated ligands, 4H-triazole ligands, 1H-triazole ligands, imidazole ligands, pyridine ligands, pyrimidine ligands, pyrazine ligands or isoquinoline ligands can be cited. As metal complexes, platinum complexes with porphyrin ligands can be cited.

[0335] Examples of substances having a light emission peak in the blue or green wavelength region include 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-triazole)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 ]), tris[3-(5-biphenyl)-5-isopropyl-4-phenyl-4H-1,2,4-triazole]iridium(III) (abbreviated as: [Ir(iPr5btz) 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) acetylacetonate (abbreviated as [FIr(acac)]) and other organic metal iridium complexes with phenylpyridine compounds having electron-withdrawing groups as ligands. Among the above metal complexes, organic metal iridium complexes having nitrogen-containing five-membered heteroaromatic ring skeletons such as 4H-triazole skeletons, 1H-triazole skeletons and imidazole skeletons are particularly preferred because of their high triplet excitation energy and excellent reliability and luminous efficiency.

[0336] Examples of substances having a light emission peak in the green or yellow wavelength region include tris(4-methyl-6-phenylpyrimidine)iridium(III) (abbreviated as [Ir(mppm) 3 ]), tri(4-tert-butyl-6-phenylpyrimidine)iridium(III) (abbreviated as: [Ir(tBuppm) 3 ]), (acetylacetonate)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-phenylpyrimidine]iridium(III) (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-dimethyl-2-[6-(2,6-dimethylphenyl)-4-pyrimidinyl-κN3]phenyl-κC}iridium(III) (abbreviated as: [Ir(dmppm-dmp) 2 (acac)]), (acetylacetonato)bis(4,6-diphenylpyrimidine)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)]), (acetylacetonate)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-phenylpyridine-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)iridium(III)acetylacetonate (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) (abbreviation: [Ir(pq) 3 ]), bis(2-phenylquinoline-N,C 2' )iridium(III) acetylacetonate (abbreviated as: [Ir(pq) 2 (acac)]) and other organic metal iridium complexes with pyridine skeletons; bis(2,4-diphenyl-1,3-oxazole-N,C 2' )iridium(III) acetylacetonate (abbreviated as: [Ir(dpo) 2 (acac)]), bis{2-[4'-(perfluorophenyl)phenyl]pyridine-N,C 2' Iridium(III) acetylacetonate (abbreviated as: [Ir(p-PF-ph) 2 (acac)]), bis(2-phenylbenzothiazole-N,C 2' )iridium(III) acetylacetonate (abbreviated as: [Ir(bt) 2 (acac)]) and other organometallic iridium complexes; tris(acetylacetonato)(monophenanthroline)terbium(III) (abbreviated as: [Tb(acac) 3 Among the above substances, organic metal iridium complexes having a pyrimidine skeleton are particularly preferred because they also have remarkably excellent reliability and luminous efficiency.

[0337] In addition, examples of substances having a light emission peak in the yellow or red wavelength region include (diisobutyrylmethane)bis[4,6-bis(3-methylphenyl)pyrimidinyl]iridium(III) (abbreviated as [Ir(5mdppm) 2 (dibm)]), bis[4,6-bis(3-methylphenyl)pyrimidinyl](dipivaloylmethanyl)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 a pyrimidine skeleton; (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 organic metal iridium complexes with pyrazine skeletons; tris(1-phenylisoquinoline-N,C 2’ )iridium(III) (abbreviation: [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 (propanedionato))(monophanation)europium (III) (abbreviated as [Eu(DBM) 3 (Phen)]), tris[1-(2-thenoyl)-3,3,3-trifluoroacetone](monophanate)europium(III) (abbreviated as: [Eu(TTA) 3 Among the above substances, organic metal iridium complexes with a pyrimidine skeleton are particularly preferred because they also have significantly high reliability and luminous efficiency. In addition, organic metal iridium complexes with a pyrazine skeleton can achieve red light with good chromaticity.

[0338] Since the organic compound having a benzofuranopyridine skeleton or a benzothienopyridine skeleton has a high T1 energy level, it is suitable for a main material of a light-emitting layer using a substance that can convert triplet excitation energy into luminescence as a light-emitting material. Therefore, as the light-emitting material contained in the light-emitting layer 140, it is preferable to use a material that can convert triplet excitation energy into luminescence. As the material that can convert triplet excitation energy into luminescence, in addition to the above-mentioned phosphorescent compounds, thermally activated delayed fluorescence (TADF) materials can be cited. Therefore, the description of phosphorescent compounds can be regarded as the description of thermally activated delayed fluorescence materials. Note that the thermally activated delayed fluorescence material refers to a material in which the difference between the triplet excitation energy level and the singlet excitation energy level is small and has the function of converting energy from the triplet excited state to the singlet excited state by anti-intersystem crossing. Therefore, the triplet excited state can be up-converted (up-converted) to the singlet excited state (anti-intersystem crossing) by a small amount of thermal energy and can efficiently present luminescence (fluorescence) from the singlet excited state. Furthermore, the condition for efficiently obtaining thermally activated delayed fluorescence is that the energy difference between the triplet excited state energy level and the singlet excited state energy level is greater than 0 eV and less than 0.2 eV, preferably greater than 0 eV and less than 0.1 eV.

[0339] When the thermally activated delayed fluorescent material is composed of one material, for example, the following materials can be used.

[0340] First, fullerene or its derivatives, acridine derivatives such as protoflavin, eosin, etc. can be cited. In addition, metal-containing porphyrins containing magnesium (Mg), zinc (Zn), cadmium (Cd), tin (Sn), platinum (Pt), indium (In) or palladium (Pd) can be cited. As the metal-containing porphyrin, for example, protoporphyrin-tin fluoride complex (abbreviated as: SnF 2 (Proto IX)), mesoporphyrin-tin fluoride complex (abbreviated as SnF 2 (Meso IX)), hematoporphyrin-tin fluoride complex (abbreviated as SnF 2 (Hemato IX)), coproporphyrin tetramethyl ester-tin fluoride complex (abbreviated as: SnF 2 (CoproⅢ-4Me)), octaethylporphyrin-tin fluoride complex (abbreviated as: SnF 2 (OEP)), protoporphyrin-tin fluoride complex (abbreviated as SnF 2 (Etio I)) and octaethylporphyrin-platinum chloride complex (PtCl 2 OEP) etc.

[0341] In addition, as a thermally activated delayed fluorescent material composed of a single material, a heteroaromatic ring compound having a π-electron-rich heteroaromatic ring and a π-electron-deficient heteroaromatic ring can also be used. Specifically, 2-(biphenyl-4-yl)-4,6-bis(12-phenylindolo[2,3-a]carbazole-11-yl)-1,3,5-triazine (abbreviated as: PIC-TRZ), 2-{4-[3-(N-phenyl-9H-carbazole-3-yl)-9H-carbazole-9-yl]phenyl}-4,6-diphenyl-1,3,5-triazine (abbreviated as: PCCzPTzn), 2-[4-(10H-phenoxazine-10-yl)phenyl]-4,6-diphenyl-1,3,5-triazine (abbreviated as: PXZ-TRZ) can be cited. , 3-[4-(5-phenyl-5,10-dihydrophenazine-10-yl)phenyl]-4,5-diphenyl-1,2,4-triazole (abbreviation: PPZ-3TPT), 3-(9,9-dimethyl-9H-acridin-10-yl)-9H-oxanthene-9-one (abbreviation: ACRXTN), bis[4-(9,9-dimethyl-9,10-dihydroacridinium)phenyl]sulfone (abbreviation: DMAC-DPS), 10-phenyl-10H,10'H-spiro[acridin-9,9'-anthracenes]-10'-one (abbreviation: ACRSA), etc. This heteroaromatic ring compound has a π-electron-rich heteroaromatic ring and a π-electron-deficient heteroaromatic ring, and therefore has high electron transport properties and hole transport properties, so it is preferred. In particular, among the skeletons having π-electron-deficient heteroaromatic rings, diazine skeletons (pyrimidine skeletons, pyrazine skeletons, pyridazine skeletons) or triazine skeletons are stable and have good reliability, so they are preferred. In addition, among the skeletons having π-electron-rich heteroaromatic rings, acridine skeletons, phenoxazine skeletons, thiophene skeletons, furan skeletons and pyrrole skeletons are stable and have good reliability, so it is preferred to have any one or more selected from these skeletons. As the pyrrole skeleton, it is particularly preferred to use an indole skeleton, a carbazole skeleton and a 3-(9-phenyl-9H-carbazole-3-yl)-9H-carbazole skeleton. In addition, in substances in which a π-electron-rich heteroaromatic ring is directly bonded to a π-electron-deficient heteroaromatic ring, the donor property of the π-electron-rich heteroaromatic ring and the acceptor property of the π-electron-deficient heteroaromatic ring are both strong, and the difference between the energy level of the singlet excited state and the energy level of the triplet excited state is small, so it is particularly preferred.

[0342] In addition, the light-emitting layer 140 may include materials other than the host material 141 and the guest material 142 .

[0343] There is no particular limitation on the material that can be used for the light-emitting layer 140. Examples of the material include anthracene derivatives, phenanthrene derivatives, pyrene derivatives, Derivatives, dibenzo[g,p] Condensed polycyclic aromatic compounds such as derivatives, specifically, 9,10-diphenylanthracene (abbreviation: DPAnth), 6,12-dimethoxy-5,11-diphenyl 9,10-bis(3,5-diphenylphenyl)anthracene (abbreviated as DPPA), 9,10-di(2-naphthyl)anthracene (abbreviated as DNA), 2-tert-butyl-9,10-di(2-naphthyl)anthracene (abbreviated as t-BuDNA), 9,9'-bianthracene (abbreviated as BANT), 9,9'-(stilbene-3,3'-diyl)phenanthrene (abbreviated as DPNS), 9,9'-(stilbene-4,4'-diyl)phenanthrene (abbreviated as DPNS2), 1,3,5-tri(1-pyrene)benzene (abbreviated as TPB3), etc. In addition, one or more substances having a singlet excitation energy level or a triplet excitation energy level higher than the excitation energy level of the guest material 142 can be selected from the above substances and known substances and used.

[0344] In addition, for example, a compound having a heteroaromatic ring skeleton such as an oxadiazole derivative can be used for the light-emitting layer 140. Specifically, for example, heteroaromatic ring compounds such as 2-(4-biphenylyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole (abbreviation: PBD), 1,3-bis[5-(p-tert-butylphenyl)-1,3,4-oxadiazole-2-yl]benzene (abbreviation: OXD-7), 9-[4-(5-phenyl-1,3,4-oxadiazole-2-yl)phenyl]-9H-carbazole (abbreviation: CO11), and 4,4'-bis(5-methylbenzoxazol-2-yl)stilbene (abbreviation: BzOs) can be cited.

[0345] In addition, metal complexes having heteroaromatic rings (e.g., zinc and aluminum metal complexes) and the like can be used for the light-emitting layer 140. For example, metal complexes including quinoline ligands, benzoquinoline ligands, oxazole ligands, or thiazole ligands can be cited. Specifically, metal complexes having a quinoline skeleton or a benzoquinoline skeleton can be cited, such as tris(8-hydroxyquinoline)aluminum(III) (abbreviated as: Alq), tris(4-methyl-8-hydroxyquinoline)aluminum(III) (abbreviated as: Almq 3 ), bis(10-hydroxybenzo[h]quinolinolato)beryllium(II) (abbreviated as: BeBq 2 ), bis(2-methyl-8-hydroxyquinoline)(4-phenylphenol)aluminum(III) (abbreviated as BAlq), bis(8-hydroxyquinoline)zinc(II) (abbreviated as Znq), etc. In addition, metal complexes having oxazolyl or thiazole ligands such as bis[2-(2-benzoxazolyl)phenol]zinc(II) (abbreviated as ZnPBO) and bis[2-(2-benzothiazolyl)phenol]zinc(II) (abbreviated as ZnBTZ) can also be used.

[0346] The light-emitting layer 140 may also be formed of a plurality of layers of more than two layers. For example, in the case where the light-emitting layer 140 is formed by stacking the first light-emitting layer and the second light-emitting layer in sequence from the hole transport layer side, a substance having a hole transport property may be used as the main material of the first light-emitting layer, and a substance having an electron transport property may be used as the main material of the second light-emitting layer. In addition, the light-emitting materials contained in the first light-emitting layer and the second light-emitting layer may also be the same or different materials. In addition, the light-emitting materials contained in the first light-emitting layer and the second light-emitting layer may be materials having the function of emitting light of the same color or materials having the function of emitting light of different colors. By using light-emitting materials having the function of emitting light of different colors from each other as two light-emitting layers, multiple light-emittings can be obtained at the same time. In particular, it is preferred to select the light-emitting materials used for each light-emitting layer so that white light emission can be obtained by combining the light emitted by the two light-emitting layers.

[0347] The light emitting layer 140 may be formed by evaporation (including vacuum evaporation), inkjet, coating, gravure printing, etc. In addition to the above materials, the light emitting layer 140 may also include inorganic compounds such as quantum dots or polymer compounds (oligomers, dendrimers, polymers, etc.).

[0348] Hole injection layer

[0349] The hole injection layer 111 has a function of promoting hole injection by lowering the injection barrier of holes from one of a pair of electrodes (electrode 101 or electrode 102), and is formed using, for example, transition metal oxides, phthalocyanine derivatives or aromatic amines. Examples of transition metal oxides include molybdenum oxides, vanadium oxides, ruthenium oxides, tungsten oxides, manganese oxides, and the like. Examples of phthalocyanine derivatives include phthalocyanine or metal phthalocyanines. Examples of aromatic amines include benzidine derivatives or phenylenediamine derivatives. In addition, polymer compounds such as polythiophene or polyaniline may be used, typically: poly(ethyldioxythiophene) / poly(styrene sulfonic acid) as self-doped polythiophene.

[0350] The hole injection layer 111 may also include a composite material of a hole transport material and a material that exhibits electron accepting properties to the hole transport material. Alternatively, a stack of a layer including a material that exhibits electron accepting properties and a layer including a hole transport material may be used. In a steady state or in the presence of an electric field, charge transfer may be performed between these materials. Examples of materials that exhibit electron accepting properties include organic acceptors such as quinone dimethane derivatives, tetrachlorobenzoquinone derivatives, and hexaazatriphenylene derivatives. Specifically, 7,7,8,8-tetracyano-2,3,5,6-tetrafluoroquinodimethane (abbreviated as: F 4Compounds having electron-withdrawing groups (halogen or cyano groups) such as chloranil, 2,3,6,7,10,11-hexacyano-1,4,5,8,9,12-hexaazatriphenylene (abbreviated as HAT-CN) can be used. In addition, transition metal oxides, such as oxides of metals of Groups 4 to 8, can also be used. Specifically, vanadium oxide, niobium oxide, tantalum oxide, chromium oxide, molybdenum oxide, tungsten oxide, manganese oxide, rhenium oxide, etc. can be used. Molybdenum oxide is particularly preferably used because it is stable in the atmosphere, has low hygroscopicity, and is easy to handle.

[0351] As the hole transport material, a material having a hole transport property higher than an electron transport property can be used, and preferably a material having a 1×10 -6 cm 2 Specifically, aromatic amines, carbazole derivatives, aromatic hydrocarbons, stilbene derivatives, and the like, which are hole transporting materials that can be used for the light-emitting layer 140, can be used. The hole transporting materials may be polymer compounds.

[0352] In addition, as hole transport materials, aromatic hydrocarbons can also be mentioned, for example, 2-tert-butyl-9,10-di(2-naphthyl)anthracene (abbreviation: t-BuDNA), 2-tert-butyl-9,10-di(1-naphthyl)anthracene, 9,10-bis(3,5-diphenylphenyl)anthracene (abbreviation: DPPA), 2-tert-butyl-9,10-bis(4-phenylphenyl)anthracene (abbreviation: t-BuDBA), 9,10-di(2-naphthyl)anthracene (abbreviation: DNA), 9,10-diphenylanthracene (abbreviation: DPAnth), 2-tert-butylanthracene (abbreviation: t-BuAnth), 9,10-bis(4-methyl-1-naphthyl)anthracene (abbreviation: D ...9,10-bis(4-methyl-1-naphthyl)anthracene (abbreviation: DBA), 9,10-di(2-naphthyl)anthracene (abbreviation: DNA), 9,10-diphenylanthracene (abbreviation: DPAnth), 9,10-bis(4-methyl-1-naph MNA), 2-tert-butyl-9,10-bis[2-(1-naphthyl)phenyl]anthracene, 9,10-bis[2-(1-naphthyl)phenyl]anthracene, 2,3,6,7-tetramethyl-9,10-di(1-naphthyl)anthracene, 2,3,6,7-tetramethyl-9,10-di(2-naphthyl)anthracene, 9,9'-bianthracene, 10,10'-diphenyl-9,9'-bianthracene, 10,10'-bis(2-phenylphenyl)-9,9'-bianthracene, 10,10'-bis[(2,3,4,5,6-pentaphenyl)phenyl]-9,9'-bianthracene, anthracene, tetracene, rubrene, perylene, 2,5,8,11-tetra(tert-butyl)perylene, and the like. In addition, pentacene, coronene, and the like can also be used. Thus, it is more preferable to use a 1×10 -6 cm 2 / Vs or more and an aromatic hydrocarbon having 14 to 42 carbon atoms.

[0353] The aromatic hydrocarbon may have a vinyl skeleton. Examples of the aromatic hydrocarbon having a vinyl group include 4,4'-bis(2,2-diphenylvinyl)biphenyl (abbreviation: DPVBi) and 9,10-bis[4-(2,2-diphenylvinyl)phenyl]anthracene (abbreviation: DPVPA).

[0354] In addition, 4-{3-[3-(9-phenyl-9H-fluoren-9-yl)phenyl]phenyl}dibenzofuran (abbreviation: mmDBFFLBi-II), 4,4',4"-(benzene-1,3,5-triyl)tri(dibenzofuran) (abbreviation: DBF3P-II), 1,3,5-tri(dibenzothiophen-4-yl)benzene (abbreviation: DBT3P-II), 2,8-diphenyl-4-[4-(9-phenyl-9H-fluoren-9-yl)phenyl]dibenzothiophene (abbreviation: DBTFLP-III), 4-[ Thiophene compounds such as 4-(9-phenyl-9H-fluorene-9-yl)phenyl]-6-phenyldibenzothiophene (abbreviated as: DBTFLP-IV), 4-[3-(triphenylene-2-yl)phenyl]dibenzothiophene (abbreviated as: mDBTPTp-II), furan compounds, fluorene compounds, triphenylene compounds, phenanthrene compounds, etc. Among them, compounds having a pyrrole skeleton, a furan skeleton, a thiophene skeleton, and an aromatic amine skeleton are stable and have good reliability, so they are preferred. Compounds having the above skeletons have high hole transport properties and also contribute to the reduction of driving voltage.

[0355] Hole transport layer

[0356] The hole transport layer 112 is a layer containing a hole transport material, and the hole transport material exemplified as the material of the hole injection layer 111 can be used. The hole transport layer 112 has a function of transporting holes injected into the hole injection layer 111 to the light-emitting layer 140, and therefore preferably has a HOMO level that is the same as or adjacent to the HOMO level of the hole injection layer 111.

[0357] In addition, it is preferred to use a 1×10 -6 cm 2 / Vs or more. However, as long as the hole transport property is higher than the electron transport property, a substance other than the above substances can be used. In addition, the layer including the substance with high hole transport property is not limited to a single layer, and two or more layers composed of the above substances can be stacked.

[0358] Electron Transport Layer

[0359] The electron transport layer 118 has a function of transporting electrons injected from the other of the pair of electrodes (electrode 101 or electrode 102) through the electron injection layer 119 to the light-emitting layer 140. As the electron transport material, a material having a higher electron transport property than a hole transport property can be used, and preferably a material having a 1×10 -6 cm 2 / Vs or more. As a compound that easily accepts electrons (a material with electron transport properties), a π-electron-deficient heteroaromatic compound such as a nitrogen-containing heteroaromatic compound or a metal complex can be used. As other specific examples, pyridine derivatives, bipyridine derivatives, pyrimidine derivatives, triazine derivatives, quinoxaline derivatives, dibenzoquinoxaline derivatives, phenanthroline derivatives, triazole derivatives, benzimidazole derivatives, oxadiazole derivatives, etc., which are electron transport materials that can be used in the light-emitting layer 140, can be cited. In addition, it is preferred that the electron transport material has a value of 1×10 -6 cm 2 / Vs or higher. In addition, as long as the electron transport property is higher than the hole transport property, a substance other than the above substances can be used as the electron transport layer. In addition, the electron transport layer 118 is not limited to a single layer, and two or more layers composed of the above substances can be stacked.

[0360] In addition, metal complexes having heteroaromatic rings can also be mentioned, for example, metal complexes including quinoline ligands, benzoquinoline ligands, oxazole ligands or thiazole ligands. Specifically, metal complexes having quinoline skeletons or benzoquinoline skeletons can be mentioned, such as tris(8-hydroxyquinoline)aluminum(III) (abbreviated as: Alq), tris(4-methyl-8-hydroxyquinoline)aluminum(III) (abbreviated as: Almq 3 ), bis(10-hydroxybenzo[h]quinolinolato)beryllium(II) (abbreviated as: BeBq 2 ), bis(2-methyl-8-hydroxyquinoline)(4-phenylphenol)aluminum(III) (abbreviated as BAlq), bis(8-hydroxyquinoline)zinc(II) (abbreviated as Znq), etc. In addition, metal complexes having oxazolyl ligands or thiazole ligands such as bis[2-(2-benzoxazolyl)phenol]zinc(II) (abbreviated as ZnPBO) and bis[2-(2-benzothiazolyl)phenol]zinc(II) (abbreviated as ZnBTZ) can also be used.

[0361] In addition, a layer for controlling the movement of electron carriers may be provided between the electron transport layer 118 and the light emitting layer 140. The layer for controlling the movement of electron carriers is a layer formed by adding a small amount of a substance with high electron capture property to the above-mentioned material with high electron transport property, and the carrier balance can be adjusted by suppressing the movement of electron carriers. This structure has a great effect on suppressing problems (such as a decrease in the life of the element) that occur when the electron transport property of the electron transport material is much higher than the hole transport property of the hole transport material.

[0362] 《Electron injection layer》

[0363] The electron injection layer 119 has the function of promoting electron injection by lowering the electron injection barrier at the interface with the electrode 102. For example, a Group 1 metal, a Group 2 metal, or their oxides, halides, carbonates, etc. can be used. In addition, a composite material of the above-mentioned electron transport material and a material that exhibits electron donating properties to the electron transport material can also be used. As materials that exhibit electron donating properties, Group 1 metals, Group 2 metals, or their oxides, etc. can be cited. Specifically, lithium fluoride (LiF), sodium fluoride (NaF), cesium fluoride (CsF), calcium fluoride (CaF 2 ) and lithium oxide (LiO x ) or other alkali metals, alkaline earth metals, or compounds of these metals. In addition, erbium fluoride (ErF 3 ) and other rare earth metal compounds. In addition, an electron salt may be used for the electron injection layer 119. As the electron salt, for example, a substance in which electrons are added to a mixed oxide of calcium and aluminum at a high concentration may be cited. In addition, a substance that can be used for the electron transport layer 118 may be used for the electron injection layer 119.

[0364] In addition, a composite material formed by mixing an organic compound with an electron donor (donor) can also be used for the electron injection layer 119. This composite material has excellent electron injection and electron transport properties because electrons are generated in the organic compound by the electron donor. In this case, the organic compound is preferably a material with excellent performance in transporting the generated electrons. Specifically, for example, the substances (metal complexes, heteroaromatic compounds, etc.) constituting the electron transport layer 118 as described above can be used. As an electron donor, any substance that exhibits electron donating properties to organic compounds can be used. Specifically, alkali metals, alkaline earth metals and rare earth metals are preferably used, and lithium, sodium, cesium, magnesium, calcium, erbium, ytterbium, etc. can be cited. In addition, alkali metal oxides or alkaline earth metal oxides are preferably used, and lithium oxide, calcium oxide, barium oxide, etc. can be cited. In addition, Lewis bases such as magnesium oxide can also be used. In addition, organic compounds such as tetrathiafulvalene (abbreviated as: TTF) can also be used.

[0365] In addition, the above-mentioned light-emitting layer, hole injection layer, hole transport layer, electron transport layer and electron injection layer can be formed by evaporation (including vacuum evaporation), inkjet, coating, gravure printing and other methods. In addition, as the above-mentioned light-emitting layer, hole injection layer, hole transport layer, electron transport layer and electron injection layer, in addition to the above-mentioned materials, inorganic compounds such as quantum dots or high molecular compounds (oligomers, dendrimers, polymers, etc.) can also be used.

[0366] "Quantum Dot"

[0367] Quantum dots are semiconductor nanocrystals with a size of several nanometers to tens of nanometers and consist of 1×10 3 to 1×10 6 The energy transfer of quantum dots depends on their size, so even quantum dots made of the same substance have different emission wavelengths depending on their size. Therefore, by changing the size of the quantum dots used, it is easy to change the emission wavelength.

[0368] In addition, the peak width of the emission spectrum of quantum dots is narrow, so luminescence with high color purity can be obtained. Furthermore, the theoretical internal quantum efficiency of quantum dots is considered to be approximately 100%, that is, it greatly exceeds 25% of organic compounds that exhibit fluorescent luminescence and is equal to organic compounds that exhibit phosphorescent luminescence. Therefore, by using quantum dots as luminescent materials, a light-emitting element with high luminescence efficiency can be obtained. Moreover, quantum dots as inorganic materials are also excellent in substantial stability, so a light-emitting element with a long service life can be obtained.

[0369] Materials constituting quantum dots include Group 14 elements, Group 15 elements, Group 16 elements, compounds containing multiple Group 14 elements, compounds of Group 4 to Group 14 elements and Group 16 elements, compounds of Group 2 elements and Group 16 elements, compounds of Group 13 elements and Group 15 elements, compounds of Group 13 elements and Group 17 elements, compounds of Group 14 elements and Group 15 elements, compounds of Group 11 elements and Group 17 elements, iron oxides, titanium oxides, chalcogenides, semiconductor clusters, and the like.

[0370] Specifically, cadmium selenide, cadmium sulfide, cadmium telluride, zinc selenide, zinc oxide, zinc sulfide, zinc telluride, mercury sulfide, mercury selenide, mercury telluride, indium arsenide, indium phosphide, gallium arsenide, gallium phosphide, indium nitride, gallium nitride, indium antimonide, gallium antimonide, aluminum phosphide, aluminum arsenide, aluminum antimonide, lead selenide, lead telluride, lead sulfide, indium selenide, indium telluride, indium sulfide, gallium selenide, arsenic sulfide, arsenic selenide, arsenic telluride, antimony sulfide, antimony selenide, antimony telluride, bismuth sulfide, bismuth selenide, bismuth telluride, silicon, silicon carbide, germanium, tin, selenium, tellurium, boron, carbon, phosphorus, boron nitride, boron phosphide, boron arsenide, aluminum nitride, aluminum sulfide, barium sulfide, barium selenide, barium telluride, calcium sulfide, calcium selenide, calcium telluride , beryllium sulfide, beryllium selenide, beryllium telluride, magnesium sulfide, magnesium selenide, germanium sulfide, germanium selenide, germanium telluride, tin sulfide, tin sulfide, tin selenide, tin telluride, lead oxide, copper fluoride, copper chloride, copper bromide, copper iodide, copper oxide, copper selenide, nickel oxide, cobalt oxide, cobalt sulfide, iron oxide, iron sulfide, manganese oxide, molybdenum sulfide, vanadium oxide, tungsten oxide, tantalum oxide, titanium oxide, zirconium oxide, silicon nitride, germanium nitride, aluminum oxide, barium titanate, selenium zinc cadmium compound, indium arsenic phosphorus compound, cadmium selenium sulfur compound, cadmium selenium tellurium compound, indium gallium arsenic compound, indium gallium selenide compound, indium selenium sulfur compound, copper indium sulfur compound and their combination, etc., but not limited to this. In addition, so-called alloy-type quantum dots with arbitrary proportions can also be used. For example, cadmium-selenium-sulfur alloy quantum dots are one of the effective methods for obtaining blue light because the emission wavelength can be changed by changing the content ratio of the elements.

[0371] As the structure of quantum dot, there are core type, core shell (Core Shell) type, core multi-shell (Core Multishell) type etc.. Any of the above can be used, but by using other inorganic materials covering the core and having a wider band gap to form a shell, the influence of defects or dangling bonds present on the surface of the nanocrystal can be reduced, thereby significantly improving the quantum efficiency of luminescence. Thus, preferably use a core shell type or core multi-shell type quantum dot. As an example of the material of the shell, zinc sulfide or zinc oxide can be cited.

[0372] In addition, in quantum dots, since the proportion of surface atoms is high, the reactivity is high and aggregation occurs easily. Therefore, the surface of the quantum dots is preferably attached with a protective agent or provided with a protective group. This can prevent aggregation and improve the solubility in solvents. In addition, the electrical stability can be improved by reducing the reactivity. Examples of protective agents (or protective groups) include: polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene ole ... ether) and other polyoxyethylene alkyl ethers; tripropyl phosphine, tributyl phosphine, trihexyl phosphine, trioctyl phosphine and other trialkyl phosphines; polyoxyethylene n-octyl phenyl ether, polyoxyethylene n-nonyl phenyl ether and other polyoxyethylene alkyl phenyl ethers; tertiary amines such as tri(n-hexyl)amine, tri(n-octyl)amine, tri(n-decyl)amine; organic phosphorus compounds such as tripropyl phosphine oxide, tributyl phosphine oxide, trihexyl phosphine oxide, trioctyl phosphine oxide, tridecyl phosphine oxide; polyethylene glycol diesters such as polyethylene glycol dilaurate and polyethylene glycol distearate; Organic nitrogen compounds such as pyridine, lutiidine, collidine, quinoline and other nitrogen-containing aromatic compounds; aminoalkanes such as hexylamine, octylamine, decylamine, dodecylamine, tetradecylamine, hexadecylamine, octadecylamine and other aminoalkanes; dialkyl sulfides such as dibutyl sulfide; dialkyl sulfoxides such as dimethyl sulfoxide and dibutyl sulfoxide; organic sulfur compounds such as sulfur-containing aromatic compounds such as thiophene; higher fatty acids such as palmitic acid, stearic acid, oleic acid; ethanol; sorbitan fatty acid esters; fatty acid-modified polyesters; tertiary amine-modified polyurethanes; polyethyleneimines, etc.

[0373] The smaller the size of the quantum dot, the larger the band gap, so the size is appropriately adjusted to obtain the desired wavelength of light. As the crystal size becomes smaller, the luminescence of the quantum dot migrates to the blue side (i.e., to the high energy side), so by changing the size of the quantum dot, the luminescence wavelength can be adjusted in the wavelength region of the spectrum covering the ultraviolet region, the visible light region, and the infrared region. The size (diameter) of the commonly used quantum dots is 0.5nm to 20nm, preferably 1nm to 10nm. In addition, the smaller the size distribution of the quantum dot, the narrower the emission spectrum, so luminescence with high color purity can be obtained. In addition, there is no particular restriction on the shape of the quantum dot, which can be spherical, rod-shaped, disc-shaped, or other shapes. In addition, the quantum rod as a rod-shaped quantum dot has the function of presenting directional light, so by using the quantum rod as a luminescent material, a light-emitting element with higher external quantum efficiency can be obtained.

[0374] In organic EL elements, the concentration quenching of the luminescent material is usually suppressed by dispersing the luminescent material in the host material, thereby improving the luminous efficiency. The host material needs to have a singlet excitation energy level or a triplet excitation energy level higher than the luminescent material. In particular, when a blue phosphorescent material is used as a luminescent material, a host material with a triplet excitation energy level higher than the blue phosphorescent material and a long life is required, and the development of such a material is extremely difficult. Here, quantum dots can ensure luminous efficiency even when only quantum dots are used to form a luminescent layer without using a host material, so a luminescent element with a long life can be obtained. When only quantum dots are used to form a luminescent layer, the quantum dots preferably have a core-shell structure (including a core-multi-shell structure).

[0375] When quantum dots are used as the light-emitting material of the light-emitting layer, the thickness of the light-emitting layer is 3nm to 100nm, preferably 10nm to 100nm, and the ratio of quantum dots contained in the light-emitting layer is 1vol.% to 100vol.%. Note that it is preferred that the light-emitting layer is formed only by quantum dots. In addition, when forming a light-emitting layer in which the quantum dots are used as light-emitting materials and dispersed in a host material, the quantum dots can be dispersed in the host material or the host material and the quantum dots can be dissolved or dispersed in a suitable liquid medium, and formed using a wet method (spin coating, casting, dispensing coating, scraping, roller coating, inkjet, printing, spraying, curtain coating, Langmuir-Blodgett method, etc.). In addition to the above-mentioned wet method, a light-emitting layer using a phosphorescent light-emitting material can also be formed by vacuum evaporation.

[0376] As the liquid medium used for the wet method, for example, ketones such as methyl ethyl ketone and cyclohexanone; fatty acid esters such as ethyl acetate; halogenated hydrocarbons such as dichlorobenzene; aromatic hydrocarbons such as toluene, xylene, mesitylene, cyclohexylbenzene; aliphatic hydrocarbons such as cyclohexane, decalin, dodecane; organic solvents such as dimethylformamide (DMF) and dimethyl sulfoxide (DMSO).

[0377] A pair of electrodes

[0378] The electrode 101 and the electrode 102 are used as an anode or a cathode of the light-emitting element. The electrode 101 and the electrode 102 can be formed using a metal, an alloy, a conductive compound, a mixture or a stacked body thereof, or the like.

[0379] One of the electrode 101 and the electrode 102 is preferably formed using a conductive material having a function of reflecting light. As the conductive material, aluminum (Al) or an alloy containing Al can be cited. As the alloy containing Al, an alloy containing Al and L (L represents one or more of titanium (Ti), neodymium (Nd), nickel (Ni) and lanthanum (La)) can be cited, for example, an alloy containing Al and Ti or an alloy containing Al, Ni and La. Aluminum has low resistivity and high light reflectivity. In addition, since aluminum is contained in large quantities in the earth's crust and is not expensive, the use of aluminum can reduce the manufacturing cost of the light-emitting element. In addition, silver (Ag), alloys containing Ag, N (N represents one or more of yttrium (Y), Nd, magnesium (Mg), ytterbium (Yb), Al, Ti, gallium (Ga), zinc (Zn), indium (In), tungsten (W), manganese (Mn), tin (Sn), iron (Fe), Ni, copper (Cu), palladium (Pd), iridium (Ir) and gold (Au) can also be used. As alloys containing silver, for example, the following alloys can be cited: alloys containing silver, palladium and copper; alloys containing silver and copper; alloys containing silver and magnesium; alloys containing silver and nickel; alloys containing silver and gold; and alloys containing silver and ytterbium, etc. In addition to the above materials, transition metals such as tungsten, chromium (Cr), molybdenum (Mo), copper and titanium can be used.

[0380] In addition, light obtained from the light-emitting layer is extracted through one or both of the electrode 101 and the electrode 102. Therefore, at least one of the electrode 101 and the electrode 102 is preferably formed using a conductive material having a function of transmitting light. Examples of the conductive material include a material having a visible light transmittance of 40% or more and 100% or less, preferably 60% or more and 100% or less, and a resistivity of 1×10 -2 Conductive materials with a resistance of Ω·cm or less.

[0381] In addition, the electrodes 101 and 102 may be formed using a conductive material having a function of transmitting light and a function of reflecting light. Examples of the conductive material include a material having a visible light reflectance of 20% or more and 80% or less, preferably 40% or more and 70% or less, and a resistivity of 1×10 -2Conductive materials with a resistance of less than Ω·cm. For example, one or more of conductive metals, alloys, and conductive compounds can be used. Specifically, for example, indium tin oxide (IndiumTin Oxide, hereinafter referred to as ITO), indium tin oxide containing silicon or silicon oxide (abbreviated as: ITSO), indium oxide-zinc oxide (Indium Zinc Oxide), indium oxide-tin oxide containing titanium, indium-titanium oxide, indium oxide containing tungsten oxide and zinc oxide and other metal oxides can be used. In addition, a metal film having a thickness that allows light to be transmitted (preferably a thickness of more than 1 nm and less than 30 nm) can be used. As the metal, for example, alloys of Ag, Ag and Al, Ag and Mg, Ag and Au, and Ag and Yb can be used.

[0382] Note that in this specification, as a material having a light-transmitting function, a material having a function of transmitting visible light and having conductivity may be used, such as the oxide conductor represented by ITO, an oxide semiconductor, or an organic conductor containing organic matter. As an organic conductor containing organic matter, for example, a composite material containing a mixed organic compound and an electron donor (donor), a composite material containing a mixed organic compound and an electron acceptor (acceptor), etc. can be cited. Inorganic carbon materials such as graphene can also be used. In addition, the resistivity of the material is preferably 1×10 5 Ω·cm or less, more preferably 1×10 4 Ω·cm or less.

[0383] In addition, one or both of the electrode 101 and the electrode 102 may be formed by laminating a plurality of the above-mentioned materials.

[0384] In order to improve the light extraction efficiency, a material having a higher refractive index than the electrode can be formed in contact with the electrode having the function of transmitting light. As such a material, as long as it has the function of transmitting visible light, it can be a conductive material or a non-conductive material. For example, in addition to the above-mentioned oxide conductors, oxide semiconductors and organic substances can also be cited. As organic substances, for example, materials illustrated as light-emitting layers, hole injection layers, hole transport layers, electron transport layers or electron injection layers can be cited. In addition, inorganic carbon materials or metal films having a thickness that allows light to be transmitted can also be used, and multiple layers having a thickness of several nm to tens of nm can also be stacked.

[0385] When the electrode 101 or the electrode 102 has a function of being used as a cathode, it is preferable to use a material with a small work function (3.8 eV or less). For example, elements belonging to Group 1 or Group 2 of the periodic table (e.g., alkali metals such as lithium, sodium, and cesium, alkaline earth metals such as calcium or strontium, magnesium, etc.), alloys containing the above elements (e.g., Ag and Mg or Al and Li), rare earth metals such as europium (Eu) or Yb, alloys containing the above rare earth metals, alloys containing aluminum and silver, etc. can be used.

[0386] When the electrode 101 or the electrode 102 is used as an anode, it is preferable to use a material having a large work function (4.0 eV or more).

[0387] Electrodes 101 and 102 may also be stacked layers of a conductive material having a function of reflecting light and a conductive material having a function of transmitting light. In this case, electrodes 101 and 102 have the function of adjusting the optical distance so that light of a desired wavelength from each light-emitting layer resonates and enhances the light of that wavelength, so this is preferred.

[0388] As a film forming method of the electrode 101 and the electrode 102 , sputtering, vapor deposition, printing, coating, MBE (Molecular Beam Epitaxy) method, CVD method, pulse laser deposition method, ALD (Atomic Layer Deposition) method, etc. can be appropriately used.

[0389] Substrate

[0390] The light-emitting element of one embodiment of the present invention can be manufactured over a substrate made of glass, plastic, etc. The order of stacking layers on the substrate may be stacked from the electrode 101 side or from the electrode 102 side.

[0391] In addition, as a substrate that can form a light-emitting element of one embodiment of the present invention, for example, glass, quartz or plastic can be used. Alternatively, a flexible substrate can also be used. A flexible substrate is a flexible substrate, such as a plastic substrate made of polycarbonate or polyarylate. In addition, a film, an inorganic vapor-deposited film, etc. can be used. Note that other materials can be used as long as they serve as a support in the manufacturing process of the light-emitting element and the optical element. Alternatively, any material can be used as long as it has the function of protecting the light-emitting element and the optical element.

[0392] For example, in this specification, etc., various substrates can be used to form a light-emitting element. There is no particular restriction on the type of substrate. As examples of the substrate, for example, a semiconductor substrate (for example, a single crystal substrate or a silicon substrate), an SOI substrate, a glass substrate, a quartz substrate, a plastic substrate, a metal substrate, a stainless steel substrate, a substrate with a stainless steel foil, a tungsten substrate, a substrate with a tungsten foil, a flexible substrate, a bonding film, a paper containing a fibrous material, or a substrate film can be used. As examples of glass substrates, there are barium borosilicate glass, aluminoborosilicate glass, soda-lime glass, etc. As flexible substrates, bonding films, substrate films, etc., the following examples can be cited. For example, plastics represented by polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyether sulfone (PES), and polytetrafluoroethylene (PTFE) can be cited. Alternatively, as an example, resins such as acrylic resins can be cited. Alternatively, as an example, polypropylene, polyester, polyvinyl fluoride, or polyvinyl chloride can be cited. Alternatively, polyamide, polyimide, aramid, epoxy resin, inorganic vapor-deposited film, paper, etc. can be cited as examples.

[0393] In addition, a flexible substrate may be used as a substrate and a light-emitting element may be directly formed on the flexible substrate. Alternatively, a peeling layer may be provided between the substrate and the light-emitting element. The peeling layer may be used when a part or all of the light-emitting element is manufactured on the peeling layer, and then it is separated from the substrate and transferred to another substrate. In this case, the light-emitting element may also be transferred to a substrate with low heat resistance or a flexible substrate. In addition, as the above-mentioned peeling layer, for example, a laminated structure of an inorganic film of a tungsten film and a silicon oxide film or a structure in which a resin film such as polyimide is formed on a substrate may be used.

[0394] That is, a light-emitting element can also be formed using one substrate, and then the light-emitting element can be transferred to another substrate. As examples of substrates to which the light-emitting element is transferred, in addition to the above-mentioned substrates, there can be cited cellophane substrates, stone substrates, wood substrates, cloth substrates (including natural fibers (silk, cotton, linen), synthetic fibers (nylon, polyurethane, polyester) or regenerated fibers (acetate, cuprammonium fiber, rayon, regenerated polyester), etc.), leather substrates, rubber substrates, etc. By using these substrates, it is possible to manufacture light-emitting elements that are not easily damaged, light-emitting elements with high heat resistance, light-emitting elements that are lightweight, or light-emitting elements that are thin.

[0395] Alternatively, a field effect transistor (FET) may be formed over the substrate, and the light emitting element 150 may be formed on an electrode electrically connected to the FET. Thus, an active matrix display device in which driving of the light emitting element 150 is controlled by the FET can be manufactured.

[0396] The structure described in this embodiment mode can be implemented in combination with the structures described in other embodiment modes as appropriate.

[0397] (Implementation 4)

[0398] In this embodiment, refer to Figure 2 A light-emitting element having a structure different from that of the light-emitting element described in Embodiment 3 will be described. Figure 2 In the Figure 1A Parts with the same functions as the reference numerals shown in the figure are shaded the same, and the reference numerals are sometimes omitted. Figure 1A Components with the same functions are denoted by the same reference numerals, and detailed description thereof may be omitted.

[0399] <Structural Example 2 of Light Emitting Element>

[0400] Figure 2 is a schematic cross-sectional view of the light emitting element 250 .

[0401] Figure 2 The light emitting element 250 shown has a plurality of light emitting units (light emitting unit 106 and light emitting unit 108) between a pair of electrodes (electrode 101 and electrode 102). One of the plurality of light emitting units preferably has Figure 1A The EL layer 100 has the same structure as shown. That is, Figure 1A The light emitting element 150 shown preferably has one light emitting unit, while the light emitting element 250 preferably has a plurality of light emitting units. Note that in the light emitting element 250, although the electrode 101 is an anode and the electrode 102 is a cathode, the structure of the light emitting element 250 may be the opposite.

[0402] exist Figure 2 In the light-emitting element 250 shown, the light-emitting unit 106 and the light-emitting unit 108 are stacked, and the charge generation layer 115 is provided between the light-emitting unit 106 and the light-emitting unit 108. In addition, the light-emitting unit 106 and the light-emitting unit 108 may have the same structure or different structures. For example, the light-emitting unit 108 preferably has the same structure as the EL layer 100.

[0403] The light emitting element 250 includes a light emitting layer 120 and a light emitting layer 170. The light emitting unit 106 includes a hole injection layer 111, a hole transport layer 112, an electron transport layer 113, and an electron injection layer 114 in addition to the light emitting layer 170. The light emitting unit 108 includes a hole injection layer 116, a hole transport layer 117, an electron transport layer 118, and an electron injection layer 119 in addition to the light emitting layer 120.

[0404] In the light-emitting element 250, either the light-emitting unit 106 or the light-emitting unit 108 may include the organometallic complex according to one embodiment of the present invention. Note that the light-emitting layer 120 or the light-emitting layer 170 is preferably used as the layer including the organic compound.

[0405] The charge generation layer 115 may have a structure in which an acceptor substance serving as an electron acceptor is added to a hole transport material, or a structure in which a donor substance serving as an electron donor is added to an electron transport material. Alternatively, these two structures may be stacked.

[0406] When the charge generation layer 115 includes a composite material composed of an organic compound and an acceptor substance, the composite material that can be used for the hole injection layer 111 shown in Embodiment 3 can be used as the composite material. As the organic compound, various compounds such as aromatic amine compounds, carbazole compounds, aromatic hydrocarbons, and polymer compounds (oligomers, dendrimers, polymers, etc.) can be used. In addition, as the organic compound, it is preferred to use an organic compound having a hole mobility of 1×10 -6 cm 2 / Vs or above. However, as long as the hole transport property is higher than the electron transport property, substances other than these can be used. Because the composite material composed of organic compounds and acceptor substances has good carrier injection and carrier transport properties, low voltage driving and low current driving can be achieved. Note that when the surface on the anode side of the light-emitting unit contacts the charge generation layer 115, the charge generation layer 115 can also have the function of the hole injection layer or hole transport layer of the light-emitting unit, so the hole injection layer or hole transport layer may not be provided in the light-emitting unit. Alternatively, when the surface on the cathode side of the light-emitting unit contacts the charge generation layer 115, the charge generation layer 115 can also have the function of the electron injection layer or electron transport layer of the light-emitting unit, so the electron injection layer or electron transport layer may not be provided in the light-emitting unit.

[0407] Note that the charge generation layer 115 may also be a stacked structure in which a layer of a composite material including an organic compound and an acceptor substance is combined with a layer composed of other materials. For example, a structure in which a layer of a composite material including an organic compound and an acceptor substance is combined with a layer including one compound selected from electron-donating substances and a compound with high electron transport properties may be combined. In addition, a structure in which a layer of a composite material including an organic compound and an acceptor substance is combined with a transparent conductive film may be combined.

[0408] The charge generation layer 115 sandwiched between the light-emitting unit 106 and the light-emitting unit 108 may have a structure that injects electrons into one light-emitting unit and injects holes into the other light-emitting unit when a voltage is applied between the electrode 101 and the electrode 102. Figure 2In the embodiment, when a voltage is applied so that the potential of the electrode 101 is higher than the potential of the electrode 102 , the charge generation layer 115 injects electrons into the light-emitting unit 106 and injects holes into the light-emitting unit 108 .

[0409] From the viewpoint of light extraction efficiency, the charge generation layer 115 preferably has visible light transmittance (specifically, visible light transmittance is 40% or more). The charge generation layer 115 functions even if its conductivity is lower than that of the pair of electrodes (electrode 101 and electrode 102).

[0410] By forming the charge generation layer 115 using the above-mentioned material, an increase in driving voltage when a light-emitting layer is stacked can be suppressed.

[0411] Although in Figure 2 , a light-emitting element having two light-emitting units is described, but the same structure can be applied to a light-emitting element having three or more light-emitting units stacked. As shown in light-emitting element 250, by arranging a plurality of light-emitting units between a pair of electrodes in a manner separated by a charge generation layer, a light-emitting element that can emit light at high brightness while maintaining a low current density and has a longer life can be realized. In addition, a light-emitting element with low power consumption can also be realized.

[0412] In addition, in each of the above structures, the luminescent colors of the guest materials used for the light-emitting unit 106 and the light-emitting unit 108 may be the same or different. When the light-emitting unit 106 and the light-emitting unit 108 include guest materials having the function of emitting luminescence of the same color, the light-emitting element 250 becomes a light-emitting element that exhibits high luminescence brightness at a lower current value, so it is preferred. In addition, when the light-emitting unit 106 and the light-emitting unit 108 include guest materials that have the function of emitting luminescence of different colors from each other, the light-emitting element 250 emits luminescence of multiple colors, so it is preferred. At this time, when multiple light-emitting materials with different luminescent wavelengths are used for one or both of the light-emitting layer 120 and the light-emitting layer 170, light with different luminescent peaks is synthesized, so the emission spectrum of the light-emitting element 250 has at least two maximum values.

[0413] The above structure is suitable for obtaining white light emission. White light emission can be obtained by making the light of the light emitting layer 120 and the light emitting layer 170 complementary colors. It is particularly preferred to select the guest material in a manner that realizes white light emission with high color rendering index or light emission having at least red, green, and blue.

[0414] In addition, in a light-emitting element having three or more stacked light-emitting units, the light-emitting colors of the guest materials used for each light-emitting unit may be the same or different. In the case where the light-emitting element includes a plurality of light-emitting units that emit light of the same color, light with a higher intensity can be emitted at a lower current value. This structure is suitable for adjusting the color of the light emission. It is particularly preferred for use in the case of using guest materials with different luminous efficiencies and exhibiting different light-emitting colors. For example, in the case of setting three light-emitting units, by setting two light-emitting units including a fluorescent material exhibiting the same light-emitting color and one light-emitting unit including a phosphorescent material exhibiting a light-emitting color different from that of the fluorescent material, the light-emitting intensity of the fluorescent light emission and the phosphorescent light emission can be adjusted. In other words, the intensity of the light-emitting color can be adjusted according to the number of light-emitting units.

[0415] In the case of using the above-mentioned light-emitting element including two fluorescent light-emitting units and one phosphorescent light-emitting unit, the following structure is preferably adopted because white light emission can be obtained efficiently: a light-emitting element including two light-emitting units including blue fluorescent materials and one light-emitting unit including yellow phosphorescent materials, a light-emitting element including two light-emitting units including blue fluorescent materials and one light-emitting layer unit including red phosphorescent materials and green phosphorescent materials, or a light-emitting element including two light-emitting units including blue fluorescent materials and one light-emitting layer unit including red phosphorescent materials, yellow phosphorescent materials and green phosphorescent materials.

[0416] In addition, at least one of the light-emitting layer 120 and the light-emitting layer 170 may be further divided into layers and each layer may contain a different light-emitting material. That is, at least one of the light-emitting layer 120 and the light-emitting layer 170 may also be formed by a plurality of layers of two or more. For example, in the case where the light-emitting layer is formed by stacking the first light-emitting layer and the second light-emitting layer in sequence from the hole transport layer side, a material having a hole transport property may be used as the main material of the first light-emitting layer, and a material having an electron transport property may be used as the main material of the second light-emitting layer. In this case, the light-emitting materials contained in the first light-emitting layer and the second light-emitting layer may also be the same or different materials. In addition, the light-emitting materials contained in the first light-emitting layer and the second light-emitting layer may be a material having the function of emitting light of the same color, or a material having the function of emitting light of different colors. By adopting a structure of multiple light-emitting materials having the function of emitting light of different colors from each other, white light with high color rendering properties composed of three primary colors or four or more light-emitting colors can also be obtained.

[0417] The light-emitting layer of the light-emitting unit 108 preferably contains a phosphorescent compound. Note that when at least one of the plurality of units contains the organometallic complex of one embodiment of the present invention, a light-emitting element with high luminous efficiency and reliability can be provided.

[0418] This embodiment mode can be combined with other embodiment modes as appropriate.

[0419] (Implementation method 5)

[0420] In this embodiment, refer to Figure 3A and Figure 3B A light-emitting device using the light-emitting element described in Embodiment Modes 3 and 4 will be described.

[0421] Figure 3A is a top view showing a light emitting device, Figure 3B is along Figure 3A AB and CD cut cross-sectional views in FIG. The light-emitting device includes a driving circuit portion (source side driving circuit) 601 for controlling the light emission of the light-emitting element, a pixel portion 602, and a driving circuit portion (gate side driving circuit) 603 indicated by a dotted line. In addition, reference numeral 604 is a sealing substrate, reference numeral 625 is a desiccant, reference numeral 605 is a sealant, and the inside surrounded by the sealant 605 is a space 607.

[0422] In addition, the guide wiring 608 is a wiring for transmitting signals input to the source side driving circuit 601 and the gate side driving circuit 603, and receives a video signal, a clock signal, a start signal, a reset signal, etc. from an FPC (flexible printed circuit) 609 used as an external input terminal. In addition, although only the FPC is shown here, the FPC may also be installed with a printed wiring board (PWB). The light-emitting device in this specification includes not only the light-emitting device body, but also a light-emitting device installed with an FPC or a PWB.

[0423] Next, refer to Figure 3B The cross-sectional structure of the light emitting device is described below. A driver circuit portion and a pixel portion are formed over an element substrate 610 , and a source-side driver circuit 601 as the driver circuit portion and one pixel in the pixel portion 602 are shown here.

[0424] In addition, in the source side driving circuit 601, a CMOS circuit combining an n-channel TFT 623 and a p-channel TFT 624 is formed. In addition, the driving circuit can also be formed using various CMOS circuits, PMOS circuits, or NMOS circuits. In addition, in this embodiment, although a driver-integrated type in which the driving circuit is formed on the substrate is shown, this structure does not necessarily have to be adopted, and the driving circuit can also be formed outside instead of being formed on the substrate.

[0425] The pixel portion 602 is formed of a pixel including a switching TFT 611, a current control TFT 612, and a first electrode 613 electrically connected to the drain thereof. An insulator 614 is formed to cover the end of the first electrode 613. The insulator 614 can be formed using a positive photosensitive resin film.

[0426] In order to increase the coverage of the film formed on the insulator 614, the upper end or the lower end of the insulator 614 is formed into a curved surface having a curvature. For example, when a photosensitive acrylic resin is used as the material of the insulator 614, it is preferable to form a curved surface only at the upper end of the insulator 614. The curvature radius of the curved surface is 0.2 μm or more and 0.3 μm or less. In addition, as the insulator 614, a negative photosensitive material or a positive photosensitive material can be used.

[0427] An EL layer 616 and a second electrode 617 are formed on the first electrode 613. Here, as a material of the first electrode 613 used as an anode, a material having a large work function is preferably used. For example, in addition to a single-layer film such as an ITO film, an indium tin oxide film containing silicon, an indium oxide film containing 2 wt% or more and 20 wt% or less of zinc oxide, a titanium nitride film, a chromium film, a tungsten film, a Zn film, or a Pt film, a stacked film composed of a titanium nitride film and a film containing aluminum as a main component, and a three-layer stacked film composed of a titanium nitride film, a film containing aluminum as a main component, and a titanium nitride film can be used. Note that when a stacked structure is used, wiring resistance is also low, good ohmic contact can be obtained, and it can be used as an anode.

[0428] The EL layer 616 is formed by various methods such as vapor deposition using a vapor deposition mask, inkjet, and spin coating. As a material constituting the EL layer 616, a low molecular compound or a high molecular compound (including an oligomer and a dendrimer) may be used.

[0429] In addition, as a material of the second electrode 617 formed on the EL layer 616 and serving as a cathode, a material having a small work function (such as Al, Mg, Li, Ca, or alloys and compounds thereof, MgAg, MgIn, and AlLi) is preferably used. Note that when light generated in the EL layer 616 is transmitted through the second electrode 617, a stacked layer composed of a metal thin film with a reduced film thickness and a transparent conductive film (such as ITO, indium oxide containing 2 wt% or more and 20 wt% or less of zinc oxide, indium tin oxide containing silicon, and zinc oxide (ZnO)) is preferably used as the second electrode 617.

[0430] In addition, a light-emitting element 618 is formed by a first electrode 613, an EL layer 616, and a second electrode 617. The light-emitting element 618 preferably has a structure described in Embodiment Mode 3 or Embodiment Mode 4. In addition, the pixel portion includes a plurality of light-emitting elements, and the light-emitting device of this embodiment mode may include both a light-emitting element having the structure described in Embodiment Mode 3 or Embodiment Mode 4 and a light-emitting element having another structure.

[0431] Furthermore, by bonding the sealing substrate 604 and the element substrate 610 together using the sealant 605, a light emitting element 618 is provided in a space 607 surrounded by the element substrate 610, the sealing substrate 604, and the sealant 605. In addition, the space 607 is filled with a filler, and in addition to being filled with an inert gas (nitrogen, argon, etc.), it is sometimes filled with a resin or a dry material, or both a resin and a dry material.

[0432] As the sealant 605, epoxy resin or glass powder is preferably used. In addition, these materials are preferably materials that do not allow moisture and oxygen to pass through as much as possible. In addition, as a material for sealing the substrate 604, in addition to a glass substrate and a quartz substrate, a plastic substrate composed of FRP (Fiber Reinforced Plastics), PVF (polyvinyl fluoride), polyester or acrylic resin can also be used.

[0433] By the above method, a light-emitting device using the light-emitting element described in Embodiment Mode 3 and Embodiment Mode 4 can be obtained.

[0434] <Structural Example 1 of Light Emitting Device>

[0435] FIG. 4 shows, as an example of a display device, an example of a light-emitting device in which a light-emitting element that emits white light and a coloring layer (color filter) are formed.

[0436] Figure 4A Shown are a substrate 1001, a base insulating film 1002, a gate insulating film 1003, gate electrodes 1006, 1007, 1008, a first interlayer insulating film 1020, a second interlayer insulating film 1021, a peripheral portion 1042, a pixel portion 1040, a driving circuit portion 1041, a first electrode 1024W, 1024R, 1024G, 1024B of the light-emitting element, a partition wall 1026, an EL layer 1028, a second electrode 1029 of the light-emitting element, a sealing substrate 1031, a sealant 1032, and the like.

[0437] In addition, Figure 4A , Figure 4B In the embodiment, the colored layers (red colored layer 1034R, green colored layer 1034G, blue colored layer 1034B) are provided on the transparent substrate 1033. In addition, a black layer (black matrix) 1035 may be provided. The transparent substrate 1033 provided with the colored layers and the black layer is aligned and fixed on the substrate 1001. In addition, the colored layers and the black layer are covered by the covering layer 1036. Figure 4AIn the figure, light is shown to be transmitted to the external luminous layer without passing through the coloring layer, and light is shown to be transmitted to the external luminous layer through the coloring layers of each color. The light that does not pass through the coloring layer becomes white light, and the light that passes through the coloring layer becomes red light, blue light, and green light, so that an image can be presented with pixels of four colors.

[0438] Figure 4B An example is shown in which a red coloring layer 1034R, a green coloring layer 1034G, and a blue coloring layer 1034B are formed between the gate insulating film 1003 and the first interlayer insulating film 1020. Figure 4B As shown, a coloring layer may be provided between the substrate 1001 and the sealing substrate 1031.

[0439] Although the light-emitting device described above has a structure in which light is emitted from the substrate 1001 side on which a TFT is formed (bottom emission type), a light-emitting device in which light is emitted from the sealing substrate 1031 side (top emission type) may also be used.

[0440] <Structural Example 2 of Light Emitting Device>

[0441] Figure 5 1001 is a cross-sectional view of a top-emitting light-emitting device. In this case, a substrate that does not allow light to pass through can be used as the substrate 1001. The process until the connection electrode for connecting the TFT and the anode of the light-emitting element is manufactured is performed in the same manner as the bottom-emitting light-emitting device. Then, a third interlayer insulating film 1037 is formed in a manner covering the electrode 1022. The insulating film may also have a planarization function. The third interlayer insulating film 1037 may be formed using the same material as the second interlayer insulating film 1021 or various other materials.

[0442] Although the first lower electrode 1025W, the lower electrode 1025R, the lower electrode 1025G, and the lower electrode 1025B of the light emitting element are all anodes here, they may also be cathodes. Figure 5 In the top emission type light-emitting device shown, the lower electrode 1025W, the lower electrode 1025R, the lower electrode 1025G, and the lower electrode 1025B are preferably reflective electrodes. In addition, the second electrode 1029 preferably has the function of emitting light and transmitting light. In addition, a microcavity structure is preferably used between the second electrode 1029 and the lower electrodes 1025W, the lower electrode 1025R, the lower electrode 1025G, and the lower electrode 1025B to amplify light of a specific wavelength. The structure of the EL layer 1028 is the same as that described in Embodiment Modes 3 and 4, and an element structure capable of obtaining white light emission is used.

[0443] exist Figure 4A , Figure 4B and Figure 5In the embodiment of the present invention, a structure of an EL layer capable of obtaining white light emission may be realized by using a plurality of light-emitting layers or a plurality of light-emitting units. Note that the structure for obtaining white light emission is not limited to this.

[0444] In adopting Figure 5 In the case of the top emission structure shown, a sealing substrate 1031 provided with a coloring layer (red coloring layer 1034R, green coloring layer 1034G, blue coloring layer 1034B) can be used for sealing. A black layer (black matrix) 1030 located between pixels can be provided on the sealing substrate 1031. The coloring layer (red coloring layer 1034R, green coloring layer 1034G, blue coloring layer 1034B) and the black layer (black matrix) 1030 can also be covered by a cover layer. In addition, a light-transmitting substrate is used as the sealing substrate 1031.

[0445] In addition, although the example of full-color display with four colors of red, green, blue, and white is shown here, it is not limited to this, and full-color display with three colors of red, green, and blue can also be performed. In addition, full-color display with four colors of red, green, blue, and yellow can also be performed.

[0446] By the above method, a light-emitting device using the light-emitting element described in Embodiment Mode 3 and Embodiment Mode 4 can be obtained.

[0447] In addition, this embodiment mode can be combined with other embodiment modes as appropriate.

[0448] (Implementation 6)

[0449] In this embodiment, an electronic device which is one embodiment of the present invention is described.

[0450] Since one embodiment of the present invention uses an organic EL light-emitting element, an electronic device having a flat surface, high luminous efficiency and high reliability can be manufactured. In addition, by one embodiment of the present invention, an electronic device having a curved surface, high luminous efficiency and high reliability can be manufactured. In addition, by using an organic compound of one embodiment of the present invention in the electronic device, an electronic device having high luminous efficiency and high reliability can be manufactured.

[0451] Examples of the electronic equipment include television sets; desktop or notebook personal computers; displays for computers, etc.; digital cameras; digital video cameras; digital photo frames; mobile phones; portable game consoles; portable information terminals; sound reproduction devices; and large-scale game machines such as pinball machines.

[0452] Fig. 6A and Figure 6BThe illustrated portable information terminal 900 includes a housing 901 , a housing 902 , a display portion 903 , a hinge portion 905 , and the like.

[0453] The housing 901 and the housing 902 are connected together by a hinge portion 905. The portable information terminal 900 can be opened from a folded state ( Fig. 6A ) is converted into Figure 6B As a result, the portability is good when carrying, and the visibility is high when using due to the large display area.

[0454] The portable information terminal 900 is provided with a flexible display portion 903 across a housing 901 and a housing 902 connected by a hinge portion 905 .

[0455] The light-emitting device manufactured using one embodiment of the present invention can be used for the display portion 903. Thus, the portable information terminal can be manufactured with a high yield.

[0456] The display portion 903 can display at least one of document information, static images, dynamic images, etc. When the document information is displayed on the display portion, the portable information terminal 900 can be used as an electronic book reader.

[0457] When the portable information terminal 900 is unfolded, the display portion 903 is maintained in a state with a large curvature radius. For example, the display portion 903 may be maintained in a manner including a portion curved with a curvature radius of 1 mm to 50 mm, preferably 5 mm to 30 mm. A portion of the display portion 903 is continuously provided with pixels across the housing 901 and the housing 902, thereby enabling curved display.

[0458] The display portion 903 is used as a touch panel and can be operated with a finger, a stylus pen, or the like.

[0459] The display unit 903 is preferably formed of a flexible display, so that a continuous display can be performed across the housing 901 and the housing 902. In addition, the housing 901 and the housing 902 can also be provided with displays respectively.

[0460] In order to prevent the angle formed by the housing 901 and the housing 902 from exceeding a predetermined angle when the portable information terminal 900 is unfolded, the hinge portion 905 preferably has a locking mechanism. For example, the locking angle (at which the portable information terminal 900 cannot be further opened) is preferably greater than 90° and less than 180°, and typically can be 90°, 120°, 135°, 150°, or 175°, etc. Thus, the convenience, safety, and reliability of the portable information terminal 900 can be improved.

[0461] When the hinge portion 905 has the above-described locking mechanism, it is possible to suppress application of an excessive force to the display portion 903, thereby preventing damage to the display portion 903. Thus, a highly reliable portable information terminal can be realized.

[0462] Housing 901 and housing 902 may also include a power button, operation buttons, an external connection port, a speaker, a microphone, and the like.

[0463] Either the housing 901 or the housing 902 may be provided with a wireless communication module, and data may be sent and received via a computer network such as the Internet, a LAN (Local Area Network), or Wireless Fidelity (Wi-Fi: registered trademark).

[0464] Figure 6C The illustrated portable information terminal 910 includes a housing 911 , a display portion 912 , operation buttons 913 , an external connection port 914 , a speaker 915 , a microphone 916 , a camera 917 , and the like.

[0465] The light-emitting device manufactured by one embodiment of the present invention can be used for the display portion 912. Thus, the portable information terminal can be manufactured with a high yield.

[0466] The portable information terminal 910 includes a touch sensor in the display portion 912. By touching the display portion 912 with a finger or a stylus pen, various operations such as making a call and inputting text can be performed.

[0467] Furthermore, by operating the operation button 913, it is possible to turn the power on and off or switch the type of image displayed on the display portion 912. For example, the e-mail composition screen can be switched to the main menu screen.

[0468] In addition, by providing a detection device such as a gyro sensor or an acceleration sensor inside the portable information terminal 910, the direction (vertical or horizontal) of the portable information terminal 910 can be determined, and the screen display direction of the display unit 912 can be automatically switched. In addition, the screen display direction can also be switched by touching the display unit 912, operating the operation button 913, or inputting a sound using the microphone 916.

[0469] The portable information terminal 910 has one or more functions selected from a telephone, a notebook, and an information reading device, for example. Specifically, the portable information terminal 910 can be used as a smart phone. The portable information terminal 910 can execute various applications such as mobile phone, e-mail, article reading and editing, music playing, animation playing, network communication, computer games, etc.

[0470] Fig.6DThe camera 920 shown includes a housing 921 , a display portion 922 , operation buttons 923 , a shutter button 924 , etc. In addition, the camera 920 is equipped with a detachable lens 926 .

[0471] The light-emitting device manufactured by one embodiment of the present invention can be used for the display portion 922. Thus, a highly reliable camera can be manufactured.

[0472] Here, although the camera 920 has a structure in which the lens 926 can be detached from the housing 921 and replaced, the lens 926 and the housing 921 may be formed integrally.

[0473] The camera 920 can capture a still image or a moving image by pressing the shutter button 924. Alternatively, the display portion 922 may have a touch panel function, and the image may be captured by touching the display portion 922.

[0474] In addition, the camera 920 may further include a flash device and a viewfinder that are separately installed. In addition, these components may also be assembled in the housing 921.

[0475] Fig. 7A is a perspective view showing a wristwatch-type portable information terminal 9200, Figure 7B It is a perspective view showing a wristwatch-type portable information terminal 9201.

[0476] Fig. 7A The portable information terminal 9200 shown can execute various applications such as mobile phones, e-mails, article reading and editing, music playing, network communication, computer games, etc. In addition, the display surface of the display unit 9001 is curved, and display can be performed along its curved display surface. In addition, the portable information terminal 9200 can perform short-range wireless communication based on communication standards. For example, by communicating with a headset that can perform wireless communication, a hands-free call can be made. In addition, the portable information terminal 9200 includes a connection terminal 9006, and data can be exchanged directly with other information terminals through a connector. In addition, charging can also be performed through the connection terminal 9006. In addition, the charging action can also be performed using wireless power supply instead of through the connection terminal 9006.

[0477] Figure 7B The portable information terminal 9201 shown is Fig. 7A The portable information terminal shown in the figure is different in that the display surface of the display portion 9001 is not curved. In addition, the display portion of the portable information terminal 9201 has a non-rectangular shape (in Figure 7B (circular in the middle).

[0478] FIG. 7C to FIG. 7E 9202 is a perspective view showing a foldable portable information terminal. Figure 7C is a perspective view of the portable information terminal 9202 in an unfolded state. Fig.7D This is a perspective view of a state in which the portable information terminal 9202 is being converted from one of the unfolded state and the folded state to the other. Fig. 7E This is a perspective view of the portable information terminal 9202 in a folded state.

[0479] The portable information terminal 9202 is easy to carry when folded, and has a large seamless display area when unfolded, so the display is easy to see at a glance. The display unit 9001 included in the portable information terminal 9202 is supported by three housings 9000 connected by hinges 9055. The portable information terminal 9202 can be reversibly changed from the unfolded state to the folded state by bending the two housings 9000 through the hinges 9055. For example, the portable information terminal 9202 can be bent with a curvature radius of 1 mm or more and 150 mm or less.

[0480] Fig. 8A Schematic diagram showing an example of a sweeping robot.

[0481] The cleaning robot 5100 includes a display 5101 on the top surface and a plurality of cameras 5102, a brush 5103 and an operation button 5104 on the side. Although not shown, the bottom surface of the cleaning robot 5100 is provided with tires and a suction port, etc. In addition, the cleaning robot 5100 also includes various sensors such as an infrared sensor, an ultrasonic sensor, an acceleration sensor, a piezoelectric sensor, an optical sensor, and a gyroscope sensor. In addition, the cleaning robot 5100 includes a wireless communication unit.

[0482] The sweeping robot 5100 can walk automatically, detect garbage 5120, and suck the garbage from the suction port on the bottom.

[0483] In addition, the cleaning robot 5100 can determine the presence or absence of obstacles such as walls, furniture, or steps by analyzing the image captured by the camera 5102. In addition, when objects such as wiring that may be wrapped around the brush 5103 are detected through image analysis, the rotation of the brush 5103 can be stopped.

[0484] The remaining battery power and the amount of attracted garbage can be displayed on the display 5101. In addition, the walking path of the cleaning robot 5100 can also be displayed on the display 5101. In addition, the display 5101 can be a touch panel, and the operation button 5104 can be displayed on the display 5101.

[0485] The cleaning robot 5100 can communicate with a portable electronic device 5140 such as a smart phone. The image captured by the camera 5102 can be displayed on the portable electronic device 5140. Therefore, the owner of the cleaning robot 5100 can also know the situation of the room when going out. In addition, the display content of the display 5101 can be confirmed using a portable electronic device such as a smart phone.

[0486] The light-emitting device of one embodiment of the present invention can be used for the display 5101.

[0487] Figure 8B The robot 2100 shown includes a computing device 2110 , an illumination sensor 2101 , a microphone 2102 , an upper camera 2103 , a speaker 2104 , a display 2105 , a lower camera 2106 , an obstacle sensor 2107 , and a moving mechanism 2108 .

[0488] The microphone 2102 has a function of detecting the user's voice and surrounding sounds, etc. In addition, the speaker 2104 has a function of emitting sound. The robot 2100 can communicate with the user using the microphone 2102 and the speaker 2104.

[0489] The display 2105 has a function of displaying various information. The robot 2100 can display the information desired by the user on the display 2105. The display 2105 can be equipped with a touch panel. The display 2105 can be a detachable information terminal, and by setting the information terminal at a predetermined position of the robot 2100, charging and data transmission and reception can be performed.

[0490] The upper camera 2103 and the lower camera 2106 have the function of photographing the surrounding environment of the robot 2100. In addition, the obstacle sensor 2107 can detect the presence or absence of obstacles in front of the robot 2100 when the robot 2100 moves using the moving mechanism 2108. The robot 2100 can recognize the surrounding environment using the upper camera 2103, the lower camera 2106, and the obstacle sensor 2107 and move safely.

[0491] The light-emitting device of one embodiment of the present invention can be used for the display 2105 .

[0492] Figure 8C5 is a diagram showing an example of a goggle-type display. The goggle-type display includes, for example, a housing 5000, a display unit 5001, a speaker 5003, an LED lamp 5004, an operation key 5005 (including a power switch or an operation switch), a connection terminal 5006, a sensor 5007 (which has a function of measuring the following factors: force, displacement, position, speed, acceleration, angular velocity, rotation speed, distance, light, liquid, magnetism, temperature, chemical substance, sound, time, hardness, electric field, current, voltage, electricity, radiation, flow, humidity, inclination, vibration, smell or infrared), a microphone 5008, a second display unit 5002, a support unit 5012, an earphone 5013, etc.

[0493] The light-emitting device of one embodiment of the present invention can be used for the display portion 5001 and the second display portion 5002 .

[0494] Fig. 9A and Fig. 9B A foldable portable information terminal 5150 is shown. The foldable portable information terminal 5150 includes a housing 5151, a display area 5152, and a bending portion 5153. Fig. 9A The portable information terminal 5150 is shown in the unfolded state. Fig. 9B The portable information terminal 5150 is shown in a folded state. Although the portable information terminal 5150 has a large display area 5152, by folding the portable information terminal 5150, the portable information terminal 5150 becomes small and has good portability.

[0495] The display area 5152 can be folded in half by the curved portion 5153. The curved portion 5153 is composed of a retractable member and a plurality of supporting members, and when folded, the retractable member is stretched so that the curved portion 5153 has a curvature radius of 2 mm or more, preferably 5 mm or more.

[0496] The display area 5152 may be a touch panel (input / output device) on which a touch sensor (input device) is mounted. The light-emitting device of one embodiment of the present invention can be used for the display area 5152 .

[0497] This embodiment mode can be combined with other embodiment modes as appropriate.

[0498] (Implementation 7)

[0499] In this embodiment, referring to FIGS. 10 and Fig.11 Examples of cases where the light-emitting element of one embodiment of the present invention is applied to various lighting devices will be described. By using the light-emitting element of one embodiment of the present invention, a lighting device with high light emission efficiency and reliability can be manufactured.

[0500] By forming the light-emitting element of one embodiment of the present invention on a flexible substrate, an electronic device or a lighting device having a light-emitting region on a curved surface can be realized.

[0501] Furthermore, a light-emitting device to which the light-emitting element of one embodiment of the present invention is applied can also be applied to lighting for an automobile provided on a windshield, a ceiling, or the like.

[0502] Fig. 10A A perspective view showing one face of the multi-function terminal 3500, Fig. 10B This is a perspective view showing another surface of the multifunctional terminal 3500. In the multifunctional terminal 3500, a display unit 3504, a camera 3506, a lighting unit 3508, and the like are incorporated into a housing 3502. The light emitting device of one embodiment of the present invention can be used for the lighting unit 3508.

[0503] The lighting 3508 including the light emitting device of one embodiment of the present invention is used as a surface light source. Therefore, unlike a point light source represented by an LED, light with low directivity can be obtained. For example, when the lighting 3508 and the camera 3506 are used in combination, the camera 3506 can be used to take pictures while lighting or flashing the lighting 3508. Because the lighting 3508 has the function of a surface light source, a picture can be obtained as if it were taken under natural light.

[0504] Notice, Fig. 10A and Fig. 10B The multifunctional terminal 3500 shown is FIG. 7A to FIG. 7C The electronic device shown may likewise have a variety of functions.

[0505] In addition, a speaker, a sensor (the sensor has the function of measuring the following factors: force, displacement, position, speed, acceleration, angular velocity, rotation speed, distance, light, liquid, magnetism, temperature, chemical substance, sound, time, hardness, electric field, current, voltage, electricity, radiation, flow, humidity, inclination, vibration, smell or infrared), a microphone, etc. can be provided inside the housing 3502. In addition, by providing a detection device having a sensor for detecting inclination such as a gyroscope and an acceleration sensor inside the multi-function terminal 3500, the direction (vertical or horizontal) of the multi-function terminal 3500 can be determined and the screen display of the display unit 3504 can be automatically switched.

[0506] In addition, the display portion 3504 can also be used as an image sensor. For example, by touching the display portion 3504 with a palm or a finger, a palm print or a fingerprint can be photographed, thereby enabling personal identification. In addition, by providing a backlight or a sensing light source that emits near-infrared light in the display portion 3504, it is also possible to photograph finger veins, palm veins, etc. Note that the light-emitting device of one embodiment of the present invention can be applied to the display portion 3504.

[0507] Fig. 10C The figure shows a perspective view of a security light 3600. The light 3600 includes a lighting 3608 on the outside of a housing 3602, and a speaker 3610 and the like are incorporated into the housing 3602. The light emitting element of one embodiment of the present invention can be used for the lighting 3608.

[0508] The lamp 3600 can emit light when the lighting 3608 is grasped or held, for example. In addition, an electronic circuit capable of controlling the light-emitting method of the lamp 3600 can be provided inside the housing 3602. As the electronic circuit, for example, a circuit capable of realizing single or intermittent multiple light emission or a circuit capable of adjusting the light emission amount by controlling the light emission current value can be used. In addition, a circuit that emits a loud alarm sound from the speaker 3610 while the lighting 3608 emits light can also be assembled.

[0509] Since the lamp 3600 can emit light in all directions, it is possible to emit light or emit light and sound to frighten criminals, etc. In addition, the lamp 3600 may include a camera such as a digital still camera having a camera function.

[0510] Fig.11 This is an example of using a light-emitting element for an indoor lighting device 8501. In addition, since the light-emitting element can be large-area, a large-area lighting device can also be formed. In addition, a lighting device 8502 in which the light-emitting area has a curved surface can be formed by using a shell having a curved surface. The light-emitting element shown in this embodiment is in the form of a thin film, so the design freedom of the shell is high. Therefore, a lighting device that can correspond to various designs can be formed. In addition, a large lighting device 8503 can also be provided on the wall of the room. In addition, a touch sensor can also be provided in the lighting device 8501, the lighting device 8502, and the lighting device 8503 to start or turn off the power.

[0511] In addition, by using the light-emitting element on the surface side of the table, a lighting device 8504 having the function of a table can be provided. In addition, by using the light-emitting element on a part of other furniture, a lighting device having the function of furniture can be provided.

[0512] As described above, by applying the light-emitting device of one embodiment of the present invention, a lighting device and an electronic device can be obtained. Note that the present invention is not limited to the lighting device and the electronic device described in this embodiment, but can be applied to electronic devices in various fields.

[0513] The structure described in this embodiment mode can be implemented in combination with the structures described in other embodiment modes as appropriate.

[0514] [Example 1]

[0515] In this example, a tri{2-[1-(2,6-diisobutylphenyl)-1H-naphtho[1,2-d]imidazol-2-yl-κN- 3 ]phenyl-κC}iridium(III) (abbreviated as: [Ir(pni-diBup) 3 ])'s synthesis method.

[0516] <Step 1: Synthesis of 2,6-diisobutylaniline>

[0517] 100 g (617 mmol) of 2,6-dichloroaniline, 230 g (2256 mmol) of isobutylboric acid, 479 g (2256 mmol) of tripotassium phosphate, 10 g (24.7 mmol) of 2-dicyclohexylphosphino-2',6'-dimethoxybiphenyl (S-phos) and 3000 mL of toluene were placed in a 5000 mL three-necked flask, the air in the flask was replaced with nitrogen, and the mixture was degassed while stirring the inside of the flask under reduced pressure. After degassing, 11 g (11.5 mmol) of tris(dibenzylideneacetone)dipalladium (0) was added, and the mixture was stirred at 120°C for 12 hours under a nitrogen stream. After a specified time, the obtained reaction solution was filtered. The obtained filtrate was refined by extraction with toluene. Then, it was refined by silica gel column chromatography. A developing solvent of hexane:toluene=15:1 was used. The obtained fractions were concentrated to obtain 79 g of the target compound as a black oil at a yield of 62%. The synthesis scheme of step 1 is represented by the following formula (A-1).

[0518] [Chemical formula 51]

[0519]

[0520] <Step 2: Synthesis of 2-nitronaphthalene-1-trifluoromethanesulfonate>

[0521] 35 g (182 mmol) of 2-nitro-1-naphthol, 500 mL of dehydrated dichloromethane and 51 mL (365 mmol) of triethylamine were placed in a 1000 mL three-necked flask, the air in the flask was replaced with nitrogen, and the flask was cooled to 0°C. Trifluoromethanesulfonic anhydride (abbreviated as Tf 2O) 40mL (243mmol), stirred at 0°C for 1 hour, and stirred at room temperature for 20 hours. After the specified time, 300mL of water and 30mL of 1M hydrochloric acid were added to the obtained mixture. Then, the mixture was refined by extraction with dichloromethane. Then, it was refined by silica gel column chromatography. A developing solvent of hexane: dichloromethane = 5:1 was used. The obtained fraction was concentrated to obtain 47g of the target yellow oil with a yield of 80%. The synthesis scheme of step 2 is represented by the following formula (A-2).

[0522] [Chemical formula 52]

[0523]

[0524] <Step 3: Synthesis of N-(2,6-diisobutylphenyl)-2-nitro-1-naphthylamine>

[0525] 30 g (146 mmol) of 2,6-diisobutylaniline synthesized in step 1, 47 g (146 mmol) of 2-nitronaphthalene-1-trifluoromethanesulfonate synthesized in step 2, 81 g (248 mmol) of cesium carbonate and 750 mL of toluene were placed in a 2000 mL three-necked flask, the air in the flask was replaced with nitrogen, and the mixture was degassed while stirring the inside of the flask under reduced pressure. After degassing, 4.8 g (11.7 mmol) of S-phos and 2.7 g (2.9 mmol) of tris(dibenzylideneacetone)dipalladium(0) were added, and stirred at 130°C for 28 hours under a nitrogen stream. After a specified time, the obtained reaction mixture was refined by extraction with toluene. Then, it was refined by silica gel column chromatography. A developing solvent of hexane:ethyl acetate=15:1 was used. The obtained fraction was concentrated to obtain 13 g of a yellow oily substance with a yield of 23%. The synthesis scheme of step 3 is represented by the following formula (A-3).

[0526] [Chemical formula 53]

[0527]

[0528] <Step 4: Synthesis of N-(2,6-diisobutylphenyl)-1,2-naphthalenediamine>

[0529] 13 g (34 mmol) of N-(2,6-diisobutylphenyl)-2-nitro-1-naphthylamine synthesized in step 3, 6.1 mL (0.34 mol) of water and 400 mL of ethanol were placed in a 1000 mL three-necked flask and stirred. 32 g (0.17 mol) of tin (II) chloride was added to the mixture, and stirred at 80°C for 5 hours under a nitrogen stream. After the specified time, the obtained reaction mixture was poured into 500 mL of 2M sodium hydroxide aqueous solution and stirred at room temperature for 2 hours. The precipitate was filtered and washed with chloroform to obtain a filtrate. The obtained filtrate was refined by extraction with chloroform. Then, it was refined by silica gel column chromatography. A developing solvent of hexane: ethyl acetate = 15:1 was used. The obtained fraction was concentrated to obtain 9.5 g of the target black oil with a yield of 81%. The synthesis scheme of step 4 is represented by the following formula (A-4).

[0530] [Chemical formula 54]

[0531]

[0532] <Step 5: Synthesis of 1-(2,6-diisobutylphenyl)-2-phenyl-1H-naphtho[1,2-d]imidazole (abbreviated as: Hpni-diBup)>

[0533] 9.5 g (27 mmol) of N-(2,6-diisobutylphenyl)-1,2-naphthalenediamine synthesized in step 4, 100 mL of acetonitrile and 2.9 g (27 mmol) of benzaldehyde were placed in a 300 mL eggplant flask and stirred at 100° C. for 6 hours. 0.044 g (0.274 mmol) of iron (III) chloride was added to the mixture and stirred at 100° C. for 16 hours. After a specified time, the obtained reaction mixture was extracted with ethyl acetate, and the obtained oily substance, 100 mL of toluene and 10 g of manganese (IV) oxide were placed in a 300 mL eggplant flask and stirred at 130° C. for 7 hours. After a specified time, the obtained reaction mixture was filtered by diatomaceous earth (Wako Pure Chemical Industries, Ltd., catalog number: 537-02305) / magnesium silicate (Wako Pure Chemical Industries, Ltd., catalog number: 066-05265) / alumina. The obtained filtrate was concentrated to obtain an oily substance. The obtained oily substance was purified by silica gel column chromatography. Toluene was used as a developing solvent. The obtained fraction was concentrated to obtain 7.9 g of the target compound as a white solid at a yield of 66%. The synthesis scheme of step 5 is represented by the following formula (A-5).

[0534] [Chemical formula 55]

[0535]

[0536] <Step 6; Di-μ-chloro-tetra{2-[1-(2,6-diisobutylphenyl)-1H-naphtho[1,2-d]imidazol-2-yl-κN 3 ]phenyl-κC}diiridium(III) (abbreviated as: [Ir(pni-diBup) 2 Cl] 2 ) Synthesis>

[0537] 3.3 g (7.7 mmol) of 1-(2,6-diisobutylphenyl)-2-phenyl-1H-naphtho[1,2-d]imidazole (abbreviated as Hpni-diBup) synthesized in step 5, 1.6 g (3.7 mmol) of iridium chloride monohydrate, 30 mL of 2-ethoxyethanol and 10 mL of water were placed in a 100 mL round-bottom flask, and the air in the flask was replaced with argon. The reaction was induced by irradiating the reaction vessel with microwaves (2.45 GHz, 100 W) for 2 hours. After the reaction, the reaction solution was filtered to obtain 2.8 g of the target yellow solid with a yield of 69%. The synthesis scheme of step 6 is represented by the following formula (A-6).

[0538] [Chemical formula 56]

[0539]

[0540] <Step 7; Tris{2-[1-(2,6-diisobutylphenyl)-1H-naphtho[1,2-d]imidazol-2-yl-κN 3 ]phenyl-κC}iridium(III) (abbreviated as: [Ir(pni-diBup) 3 ]) Synthesis>

[0541] The di-μ-chloro-tetra{2-[1-(2,6-diisobutylphenyl)-1H-naphtho[1,2-d]imidazol-2-yl-κN 3 ]phenyl-κC}diiridium(III) (abbreviated as: [Ir(pni-diBup) 2 Cl] 2)2.0g (0.92mmol) and 150mL of dichloromethane were placed in a 500mL three-necked flask and stirred under a nitrogen stream. A mixed solution of 0.72g (2.8mmol) of silver trifluoromethanesulfonate and 150mL of methanol was dripped into the mixed solution and stirred in a dark place for 3 days. After the reaction for a specified time, the reaction mixture was filtered through diatomaceous earth. The obtained filtrate was concentrated to obtain 2.7g of a yellow solid. The obtained solid 2.7g, 50mL of ethanol and 1.6g (3.7mmol) of 1-(2,6-diisobutylphenyl)-2-phenyl-1H-naphtho[1,2-d]imidazole (abbreviated as: Hpni-diBup) synthesized by the method of step 5 were placed in a 500mL eggplant-shaped flask and heated under reflux for 20 hours under a nitrogen stream. After the reaction for a specified time, the reaction mixture was filtered to obtain a solid. The obtained solid was dissolved in dichloromethane and filtered through diatomaceous earth / neutral silica gel / diatomaceous earth. The obtained filtrate was concentrated to obtain a solid. The obtained solid was refined by silica gel column chromatography. A developing solvent of dichloromethane:hexane=1:3 was used. The obtained fraction was concentrated to obtain a solid. The obtained solid was recrystallized using ethyl acetate / hexane to obtain 1.1 g of a solid in a yield of 40%. The synthesis scheme is represented by the following formula (A-7).

[0542] [Chemical formula 57]

[0543]

[0544] 1.1 g of the obtained solid was sublimated and refined by gradient sublimation method. The obtained solid was heated at 340°C for 41 hours under the conditions of pressure of 2.6 Pa and argon flow rate of 10.5 mL / min for sublimation refining. After sublimation refining, 0.93 g of yellow solid was obtained with a recovery rate of 88%.

[0545] The yellow solid obtained in the above step was subjected to proton NMR ( 1 H-NMR) measurement. The obtained values ​​are shown below. In addition, Fig.12 Show 1 H-NMR spectrum. Fig.12 It can be seen that the organometallic complex [Ir(pni-diBup) 3 ].

[0546] 1 H-NMR.δ(CD 2 Cl 2): 0.15 (d, 9H), 0.39-0.42 (m, 18H), 0.59 (d, 9H), 1.27-1.35 (m, 3H), 1.78-1.86 (m, 3H), 1.93-2.02 (m, 6H), 2.33 (d, 6H), 6.35-6.40 (m, 6H), 6.56-6.61(m, 6H), 7.04-7.07(m, 6H), 7.16(t, 3H), 7.25(d, 3H), 7.30(t, 3H), 7.40(d, 3H), 7.48(d, 3H), 7.63(t, 3H), 7.73(d, 3H).

[0547] Next, measure [Ir(pni-diBup) 3 ] solution (hereinafter referred to as "absorption spectrum") and emission spectrum. When measuring the absorption spectrum, a UV-visible spectrophotometer (V550 manufactured by JASCO Corporation) was used to measure [Ir(pni-diBup) 3 ] was placed in a quartz dish with a dichloromethane deoxygenated solution (0.0089 mmol / L) and measured at room temperature. In addition, when measuring the emission spectrum and the luminescence quantum yield, an absolute PL quantum yield measuring device (manufactured by Hamamatsu Photonics Co., Ltd., C11347-01) was used in a glove box (manufactured by Japan Bright Co., Ltd., LABstar M13 (1250 / 780)) under a nitrogen atmosphere. A dichloromethane deoxygenated solution (0.0089 mmol / L) was placed in a quartz dish, sealed, and measured at room temperature. Fig.13 The measurement results of the obtained absorption spectrum and emission spectrum are shown. The horizontal axis represents the wavelength, and the vertical axis represents the absorption intensity and the emission intensity. Fig.13 The absorption spectrum shown represents the result obtained by subtracting the absorption spectrum measured by placing only dichloromethane in a quartz cell from the absorption spectrum measured by placing a deoxygenated dichloromethane solution in a quartz cell.

[0548] like Fig.13 As shown, the iridium complex [Ir(pni-diBup) 3 ] has emission peaks at 500 and 536 nm, and green emission was observed from a dichloromethane deoxygenated solution.

[0549] In addition, it can be seen from the measurement that the luminescence quantum yield in the dichloromethane deoxygenated solution at an excitation wavelength of 450nm is extremely high, namely 98%.

[0550] [Example 2]

[0551] In this example, the organometallic complex of one embodiment of the present invention represented by the structural formula (101) in Embodiment 1 is described as bis{2-[1-(2,6-diisobutylphenyl)-1H-naphtho[1,2-d]imidazol-2-yl-κN 3 ]phenyl-κC}[2-(4-methyl-5-phenyl-2-pyridinyl-κN 2 )phenyl-κC]iridium(III) (abbreviated as: [Ir(pni-diBup) 2 (mdppy)]).

[0552] <Step 1; Bis{2-[1-(2,6-diisobutylphenyl)-1H-naphtho[1,2-d]imidazol-2-yl-κN 3 ]phenyl-κC}[2-(4-methyl-5-phenyl-2-pyridinyl-κN 2 )phenyl-κC]iridium(III) (abbreviated as: [Ir(pni-diBup) 2 Synthesis of (mdppy)])>

[0553] Di-μ-chloro-tetrakis[2-(4-methyl-5-phenyl-2-pyridyl-κN)phenyl-κC]diiridium(III) (abbreviated as [Ir(mdppy) 2 Cl] 2 )1.3g (0.9mmol) and dichloromethane 180mL were placed in a 500mL three-necked flask and stirred under a nitrogen stream. A mixed solution of 0.7g (2.7mmol) of silver trifluoromethanesulfonate and 35mL of methanol was dripped into the mixed solution and stirred in a dark place for 18 hours. After the reaction for a specified time, the reaction mixture was filtered through diatomaceous earth. The filtrate obtained was concentrated to obtain 1.9g of a yellow solid. The obtained yellow solid 1.9g, methanol 30mL, ethanol 30mL and Hpni-diBup1.6g (3.6mmol) were placed in a 300mL eggplant-shaped flask and heated under reflux for 23 hours under a nitrogen stream. After the reaction for a specified time, the reaction mixture was filtered to remove insoluble matter, and then the filtrate was concentrated to obtain a solid. 60mL of 1-butanol was added to the obtained solid, and heated under reflux for 22 hours under a nitrogen stream. After the reaction for a specified time, the reaction mixture was filtered to obtain a solid. The obtained solid was refined by silica gel column chromatography. As a developing solvent, a mixed solvent of hexane: dichloromethane = 3:1 was used. The obtained fraction was concentrated to obtain a solid. The obtained solid was recrystallized using ethyl acetate / hexane to obtain 0.20 g of the target yellow solid at a yield of 9%. The synthesis scheme is represented by the following formula (B-1).

[0554] [Chemical formula 58]

[0555]

[0556] The obtained solid (0.19 g) was sublimated and refined by gradient sublimation method. The obtained solid was heated at 320°C for 18 hours under the conditions of pressure of 2.5 Pa and argon flow rate of 10.3 mL / min for sublimation refining. After sublimation refining, 0.14 g of yellow solid was obtained with a recovery rate of 72%.

[0557] The yellow solid obtained in the above steps was 1 H-NMR measurement. The obtained values ​​are shown below. In addition, Fig.14 Show 1 H-NMR spectrum. Fig.14 It can be seen that the organometallic complex [Ir(pni-diBup) 2 (mdppy)].

[0558] 1 H-NMR.δ(CD 2 Cl 2 ): 0.09-0.15(m, 9H), 0.29-0.34(m, 9H), 0.40(t, 1H), 0.45(d, 3H), 0.51(d, 3H), 1.18-1.24(m, 1H), 1.34- 1.49 (m, 1H), 1.70-1.78 (m, 1H), 1.88-2.09 (m, 6H), 2.17-2.25 (m, 2H), 2.51 (s, 3H), 6.30-6.40 (m, 3H), 6. 48 (t, 1H), 6.61-6.52 (m, 3H), 6.64-6.69 (m, 2H), 6.74-6.79 (m, 2H), 6.83 (t, 1H), 6.93-7.01 (m, 3H), 7.08 (t, 1H), 7.13-7.25 (m, 8H), 7.34-7.51 (m, 6H), 7.57-7.73 (m, 4H), 7.87 (d, 1H), 7.94 (s, 1H), 8.31 (s, 1H).

[0559] Next, measure [Ir(pni-diBup) 2 The absorption spectrum, emission spectrum and luminescence quantum yield of a dichloromethane deoxygenated solution (0.0073 mmol / L) of 1,4-dichloro-2-nitrogen (mdppy)] were measured in the same manner as in Example 1. Fig.15 The measurement results of the absorption spectrum and the emission spectrum are shown.

[0560] like Fig.15 As shown, the iridium complex [Ir(pni-diBup) 2(mdppy)] had a luminescence peak at 530 nm, and green luminescence was observed from a dichloromethane deoxygenated solution.

[0561] In addition, it was found through measurement that the luminescence quantum yield in the dichloromethane deoxygenated solution (0.0073 mmol / L) at an excitation wavelength of 450 nm was extremely high, namely 98%.

[0562] [Example 3]

[0563] In this example, a tri{2-[1-(4-cyano-2-isobutylphenyl)-1H-naphtho[1,2-d]imidazol-2-yl-κN- 3 ]phenyl-κC}iridium(III) (abbreviated as: [Ir(pni-iBuCNp) 3 ])'s synthesis method.

[0564] <Step 1: Synthesis of 4-amino-3-isobutylbenzonitrile>

[0565] 75 g (492 mmol) of 4-amino-3-chlorobenzonitrile, 90 g (886 mmol) of isobutylboric acid, 188 g (886 mmol) of tripotassium phosphate, 4.0 g (9.8 mmol) of 2-dicyclohexylphosphino-2', 6'-dimethoxybiphenyl (S-phos) and 2400 mL of toluene were placed in a 5000 mL three-necked flask, the air in the flask was replaced with nitrogen, and the mixture was degassed while stirring the inside of the flask under reduced pressure. After degassing, 4.5 g (4.9 mmol) of tris(dibenzylideneacetone)dipalladium (0) was added, and stirred at 120° C. for 20 hours under a nitrogen stream. After a specified time, the obtained reaction solution was filtered. The obtained filtrate was refined by extraction with toluene. Then, it was refined by silica gel column chromatography. Toluene was used as a developing solvent. The obtained fraction was concentrated, thereby obtaining 59 g of a brown oily substance of the target substance with a yield of 69%. The synthesis scheme of step 1 is represented by the following formula (C-1).

[0566] [Chemical formula 59]

[0567]

[0568] <Step 2: Synthesis of 3-isobutyl-4-[N-(2-nitronaphthyl)amino]benzonitrile>

[0569] 30 g (170 mmol) of 4-amino-3-isobutylbenzonitrile synthesized in step 1, 45 g (141 mmol) of 2-nitronaphthalene-1-trifluoromethanesulfonate, 78 g (240 mmol) of cesium carbonate and 750 mL of toluene were placed in a 2000 mL three-necked flask, the air in the flask was replaced with nitrogen, and the mixture was degassed while stirring the inside of the flask under reduced pressure. After degassing, 4.6 g (11 mmol) of 2-dicyclohexylphosphino-2', 6'-dimethoxybiphenyl (S-phos) and 2.6 g (2.8 mmol) of tris(dibenzylideneacetone)dipalladium (0) were added, and stirred at 130°C for 24 hours under a nitrogen stream. After a specified time, the obtained reaction mixture was refined by extraction with toluene. Then, it was refined by silica gel column chromatography. A developing solvent of hexane:ethyl acetate = 10:1 was used. The obtained fractions were concentrated to obtain 40 g of the target compound as a yellow oil at a yield of 82%. The synthesis scheme of step 2 is represented by the following formula (C-2).

[0570] [Chemical formula 60]

[0571]

[0572] <Step 3; Synthesis of 3-isobutyl-4-[N-(1,2-naphthalenediamine)]benzonitrile>

[0573] 40 g (115 mmol) of 3-isobutyl-4-[N-(2-nitronaphthyl)amino]benzonitrile synthesized in step 2, 21 mL (1.2 mol) of water and 1350 mL of ethanol were placed in a 3000 mL three-necked flask and stirred. 109 g (0.58 mol) of tin (II) chloride was added to the mixture, and stirred at 80 ° C for 6 hours under a nitrogen stream. After the specified time, the obtained reaction mixture was poured into 500 mL of 2M sodium hydroxide aqueous solution and stirred at room temperature for 2 hours. The precipitate was filtered and washed with chloroform to obtain a filtrate. The obtained filtrate was refined by extraction with chloroform. Then, hexane was added to the obtained solid and filtered, thereby obtaining 32 g of a white solid with a yield of 88%. The synthesis scheme of step 3 is represented by the following formula (C-3).

[0574] [Chemical formula 61]

[0575]

[0576] <Step 4: Synthesis of 1-(4-cyano-2-isobutylphenyl)-2-phenyl-1H-naphtho[1,2-d]imidazole (abbreviated as: Hpni-iBuCNp)>

[0577] 32 g (101 mmol) of 3-isobutyl-4-[N-(1,2-naphthalenediamine)]benzonitrile synthesized in step 3, 400 mL of acetonitrile and 11 g (101 mmol) of benzaldehyde were placed in a 1000 mL three-necked flask and stirred at 100°C for 6 hours. 0.16 g (1.0 mmol) of iron (III) chloride was added to the mixture and stirred at 100°C for 16 hours. After the specified time, the reaction mixture was extracted with ethyl acetate. Then, the solid was purified by silica gel column chromatography. As the developing solvent, toluene was first used, followed by a mixed solvent of toluene:ethyl acetate = 18:1. The obtained fraction was concentrated to obtain a solid. Ethyl acetate was added to the obtained solid and filtered to obtain 14 g of the target substance as a white solid with a yield of 34%. The synthesis scheme of step 4 is represented by the following formula (C-4).

[0578] [Chemical formula 62]

[0579]

[0580] <Step 5; tri{2-[1-(4-cyano-2-isobutylphenyl)-1H-naphtho[1,2-d]imidazol-2-yl-κN 3 ]phenyl-κC}iridium(III) (abbreviated as: [Ir(pni-iBuCNp) 3 ]) Synthesis>

[0581] 3.8 g (9.5 mmol) of 1-(4-cyano-2-isobutylphenyl)-2-phenyl-1H-naphtho[1,2-d]imidazole synthesized by the method of step 4 and 0.93 g (1.9 mmol) of tris(acetylacetone)iridium(III) were placed in a reaction vessel equipped with a three-way stopcock and heated at 250°C for 40 hours. Dichloromethane was added to the obtained reaction mixture, and insoluble matter was removed. The obtained filtrate was concentrated to obtain a solid. The obtained solid was refined by silica gel column chromatography. Dichloromethane was used as a developing solvent. The obtained fraction was concentrated to obtain a solid. The obtained solid was recrystallized using ethyl acetate / hexane. Thus, 0.3 g of a yellow solid was obtained with a yield of 10%. This synthesis scheme is represented by the following formula (C-5).

[0582] [Chemical formula 63]

[0583]

[0584] The mass (MS) of the yellow solid obtained in the above step was measured. The ESI-MS measurement results of the obtained compound are shown below. ESI-MS [M+H +]=1394.51(Exact Mass=1393.51). It can be seen from this that [Ir(pni-iBuCNp)] of one embodiment of the organometallic complex of the present invention represented by the above structural formula (102) is obtained. 3 ]).

[0585] Next, the [Ir(pni-iBuCNp) 3 The absorption spectrum and emission spectrum of the dichloromethane deoxygenated solution (0.013 mmol / L) of ] were measured in the same manner as in Example 1. Fig.16 Absorption spectrum and emission spectrum are shown.

[0586] like Fig.16 As shown, the iridium complex [Ir(pni-iBuCNp) 3 ] has emission peaks at 509 and 544 nm, and green emission is observed from a dichloromethane deoxygenated solution.

[0587] [Example 4]

[0588] In this example, a tri{2-[1-(4-cyano-2,6-diisobutylphenyl)-1H-naphtho[1,2-d]imidazol-2-yl-κN- 3 ]phenyl-κC}iridium(III) (abbreviated as: [Ir(pni-diBuCNp) 3 ])'s synthesis method.

[0589] <Step 1: Synthesis of 4-amino-3,5-diisobutylbenzonitrile>

[0590] 58g (310mmol) of 4-amino-3,5-diisobutylbenzonitrile, 117g (1145mmol) of isobutylboric acid, 243g (1145mmol) of tripotassium phosphate, 6.4g (15.5mmol) of 2-dicyclohexylphosphino-2',6'-dimethoxybiphenyl (S-phos) and 1500ml of toluene were placed in a 3000mL three-necked reaction vessel, the air in the flask was replaced with nitrogen, and the mixture was degassed while the inside of the flask was depressurized. After degassing, 5.7g (6.2mmol) of tris(dibenzylideneacetone)dipalladium (0) was added, and stirred at 130°C for 12 hours under a nitrogen stream. Toluene was added to the obtained reaction solution, and suction was performed through diatomaceous earth. The obtained filtrate was refined by extraction with toluene. Then, it was refined by silica gel column chromatography. Toluene was used as a developing solvent. The obtained fractions were concentrated to obtain 69 g of the target compound as a yellow oil with a yield of 96%. The synthesis scheme of step 1 is represented by the following formula (D-1).

[0591] [Chemical formula 64]

[0592]

[0593] <Step 2: Synthesis of 3,5-diisobutyl-4-[N-(2-nitronaphthyl)amino]benzonitrile>

[0594] 28 g (121 mmol) of 4-amino-3,5-diisobutylbenzonitrile synthesized in step 1, 39 g (121 mmol) of 2-nitronaphthalene-1-trifluoromethanesulfonate, 67 g (205 mmol) of cesium carbonate and 750 mL of toluene were placed in a 2000 mL three-necked flask, the air in the flask was replaced with nitrogen, and the mixture was degassed while stirring the inside of the flask under reduced pressure. After degassing, 4.0 g (9.7 mmol) of 2-dicyclohexylphosphino-2',6'-dimethoxybiphenyl (S-phos) and 2.2 g (2.4 mmol) of tris(dibenzylideneacetone)dipalladium (0) were added, and stirred at 130°C for 40 hours under a nitrogen stream. After a specified time, the obtained reaction mixture was refined by extraction with toluene. Then, it was refined by silica gel column chromatography. A developing solvent of hexane:ethyl acetate = 10:1 was used. The obtained fraction was concentrated to obtain 4.5 g of the target compound as an orange solid at a yield of 9%. The synthesis scheme of step 2 is represented by the following formula (D-2).

[0595] [Chemical formula 65]

[0596]

[0597] <Step 3; Synthesis of 3,5-diisobutyl-4-[N-(1,2-naphthalenediamine)]benzonitrile>

[0598] 4.5 g (11 mmol) of 3,5-diisobutyl-4-[N-(2-nitronaphthyl)amino]benzonitrile synthesized in step 2, 2 mL (110 mmol) of water and 130 mL of ethanol were placed in a 500 mL three-necked flask and stirred. 10.4 g (55 mmol) of tin (II) chloride was added to the mixture, and stirred at 80°C for 7.5 hours under a nitrogen stream. After the specified time, the obtained reaction mixture was poured into 100 mL of 2M sodium hydroxide aqueous solution and stirred at room temperature for 2 hours. The precipitate was filtered and washed with chloroform to obtain a filtrate. The obtained filtrate was extracted with chloroform. Then, the obtained extract solution was concentrated to obtain 4.1 g of the target black oil with a yield of 99%. The synthesis scheme of step 3 is represented by the following formula (D-3).

[0599] [Chemical formula 66]

[0600]

[0601] <Step 4: Synthesis of 1-(4-cyano-2,6-diisobutylphenyl)-2-phenyl-1H-naphtho[1,2-d]imidazole (abbreviated as: Hpni-diBuCNp)>

[0602] 4.2 g (11 mmol) of 3,5-diisobutyl-4-[N-(1,2-naphthalenediamine)]benzonitrile synthesized in step 3, 50 mL of acetonitrile and 1.2 g (11 mmol) of benzaldehyde were placed in a 500 mL three-necked flask and stirred at 100°C for 8 hours. 18 mg (0.11 mmol) of iron (III) chloride was added to the mixture and stirred at 100°C for 29 hours. After the specified time, the obtained reaction mixture was refined by extraction with ethyl acetate. Then, the obtained solid was refined by silica gel column chromatography. As the developing solvent, toluene was first used, followed by a mixed solvent of toluene:ethyl acetate = 20:1. The obtained fraction was concentrated to obtain 2.9 g of the target black oil with a yield of 58%. The synthesis scheme of step 4 is represented by the following formula (D-4).

[0603] [Chemical formula 67]

[0604]

[0605] <Step 5; tri{2-[1-(4-cyano-2,6-diisobutylphenyl)-1H-naphtho[1,2-d]imidazol-2-yl-κN 3 ]phenyl-κC}iridium(III) (abbreviated as: [Ir(pni-diBuCNp) 3 ]) Synthesis>

[0606] 2.9 g (6.3 mmol) of 1-(4-cyano-2,6-diisobutylphenyl)-2-phenyl-1H-naphtho[1,2-d]imidazole synthesized by the method of steps 1 to 4 and 0.62 g (1.3 mmol) of tris(acetylacetone)iridium(III) were placed in a reaction vessel equipped with a three-way stopcock and heated at 250°C for 56 hours. Toluene was added to the obtained reaction mixture and filtered to remove insoluble matter. The obtained filtrate was concentrated to obtain a solid. The obtained solid was refined by silica gel column chromatography. Toluene was used as a developing solvent. The obtained fraction was concentrated to obtain a solid. The obtained solid was recrystallized using ethyl acetate / hexane, thereby obtaining 0.33 g of a yellow solid with a yield of 16%. The synthesis scheme is represented by the following formula (D-5).

[0607] [Chemical formula 68]

[0608]

[0609] 0.32 g of the obtained solid was sublimated and refined by gradient sublimation method. The sublimation was carried out by heating at 345° C. for 17 hours under the conditions of pressure of 2.5 Pa and argon flow rate of 10.4 mL / min. After sublimation, 0.10 g of yellow solid was obtained with a recovery rate of 31%.

[0610] The yellow solid obtained in the above steps was 1 H-NMR measurement. The obtained values ​​are shown below. In addition, Fig.17 Show 1 H-NMR spectrum. Fig.17 It can be seen that the organometallic complex [Ir(pni-diBuCNp) 3 ].

[0611] 1 H-NMR.δ(ppm from CH 2 Cl 2 ), (CD 2 Cl 2 ): -0.38(d, 3H), -0.13--0.06(m, 9H), 0.35(d, 3H), 0.41-0.45(m, 6H), 0.54-0.57(m, 6H), 0.62-0.6 5(m, 6H), 0.70(d, 3H), 1.14-1.23(m, 1H), 1.27-1.35(m, 1H), 1.40-1.49(m, 1H), 1.50-1.57(m, 1H), 1.60-1.66(m, 2H), 1.71-1.90(m, 4H), 2.06-2.15(m, 2H), 2.22-2.31(m, 4H), 2.33-2.42(t, 2H), 6.3 2-6.39 (m, 3H), 6.53-6.85 (m, 12H), 6.96 (t, 2H), 7.06 (d, 1H), 7.10-7.37 (m, 9H), 7.66-7.83 (m, 9H).

[0612] Next, measure [Ir(pni-diBuCNp) 3 ]'s absorption spectrum, emission spectrum and luminescence quantum yield of dichloromethane deoxygenated solution (0.0084 mmol / L). Fig.18 The measurement results of the absorption spectrum and the emission spectrum are shown.

[0613] like Fig.18 As shown, the iridium complex [Ir(pni-diBuCNp) 3 ] has emission peaks at 510 and 547 nm, and green emission is observed from a dichloromethane deoxygenated solution.

[0614] In addition, it was found through measurement that the luminescence quantum yield in the dichloromethane deoxygenated solution (0.0084 mmol / L) at an excitation wavelength of 450 nm was extremely high, namely 91%.

[0615] [Example 5]

[0616] [Ir(pni-diBup) 3 ]、[Ir(pni-diBup) 2 (mdppy)] and [Ir(pni-diBuCNp) 3 The luminescence quantum yield of the comparative substance (OC-6-22)-tri{2-[1-(2,6-diisobutylphenyl)-1H-benzimidazol-2-yl-κN 3 ]phenyl-κC}iridium(III) (abbreviation: fac-[Ir(pbi-diBup) 3 The luminescence quantum yield of ] was measured. The measurement was carried out in the same manner as described in Example 1. Table 1 shows the results.

[0617] [Table 1]

[0618] Material Name Quantum yield (%) <![CDATA[fac-[Ir(pbi-diBup) 3 ]]]> 88 <![CDATA[[Ir(pni-diBup) 3 ]]]> 98 <![CDATA[[ir(pni-diBup) 2 (mdppy)]]]> 98 <![CDATA[[Ir(pni-diBuCNp) 3 ]]]> 91

[0619] [Ir(pni-diBup)] of the organometallic complex of one embodiment of the present invention 3 ] and fac-[Ir(pbi-diBup) 3 ] is whether or not a fused benzene ring is included in the g position of the benzimidazole skeleton. As shown in Table 1, the luminescence quantum yield of the organometallic complex of one embodiment of the present invention is relatively high. In addition, it can be seen that the luminescence quantum yield of the organometallic complex whose ligand contains a 1H-naphtho[1,2-d]imidazole skeleton is extremely high, i.e., more than 90%.

[0620] [Example 6]

[0621] In this embodiment, production examples of a light-emitting element including an organic compound according to one embodiment of the present invention and a comparative light-emitting element and characteristics of the light-emitting elements are described. Figure 1A The stacked structure of the light emitting element manufactured in this example is shown. In addition, Table 2 shows the details of the element structure. In addition, the organic compounds used in this example are shown below. In addition, for other organic compounds, refer to other embodiments or examples.

[0622] [Chemical formula 69]

[0623]

[0624] [Table 2]

[0625]

[0626] 《Manufacturing of Comparative Light-Emitting Element 1》

[0627] As the electrode 101, a 70 nm thick ITSO film was formed on a glass substrate by sputtering. The electrode 101 had an electrode area of ​​4 mm 2 (2 mm × 2 mm). Next, as a pretreatment for forming a light-emitting element on the substrate, the substrate surface was cleaned with water, dried at 200°C for 1 hour, and then subjected to UV ozone treatment for 370 seconds. -4 The substrate was baked at 170° C. for 30 minutes in a vacuum deposition apparatus with a vacuum degree of about 1000 Å. Then, the substrate was cooled for about 30 minutes.

[0628] Next, DBT3P-II: molybdenum (VI) oxide (MoO 3 ) were co-evaporated in a weight ratio of 1:0.5 and a thickness of 40 nm.

[0629] Next, PCCP was deposited on the hole injection layer 111 to a thickness of 20 nm as the hole transport layer 112 .

[0630] As the light-emitting layer 140, 4,6mCzP2Pm:PCCP:[Ir(ppy) 3 ] are co-evaporated in a weight ratio of 0.6:0.4:0.1 and a thickness of 40 nm. In addition, in the light-emitting layer 140, [Ir(ppy) 3 ] is a guest material that exhibits phosphorescence.

[0631] Next, as the electron transport layer 118(1), 4,6mCzP2Pm was deposited to a thickness of 20 nm on the light emitting layer 140. Next, as the electron transport layer 118(2), NBPhen was deposited to a thickness of 10 nm on the electron transport layer 118(1).

[0632] Next, LiF was deposited on the electron transport layer 118 to a thickness of 1 nm as the electron injection layer 119 .

[0633] Next, aluminum (Al) was formed as the electrode 102 on the electron injection layer 119 to a thickness of 200 nm.

[0634] Next, in a glove box with a nitrogen atmosphere, a substrate (counter substrate) different from the substrate on which the light-emitting element is formed is fixed to the substrate on which the light-emitting element is formed and sealed with a sealant, thereby sealing the comparative light-emitting element 1. Specifically, a desiccant is attached to the counter substrate, and the counter substrate coated with the sealant and the glass substrate on which the light-emitting element is formed are attached near the area where the light-emitting element is formed, and irradiation with 6 J / cm at a wavelength of 365 nm is performed. 2 The reaction mixture was heated at 80° C. for 1 hour under ultraviolet light. The comparative light-emitting element 1 was obtained through the above steps.

[0635] 《Manufacturing of Comparative Light-Emitting Element 2, Comparative Light-Emitting Element 3 and Light-Emitting Element 4》

[0636] The manufacturing process of the comparative light-emitting element 2, the comparative light-emitting element 3 and the light-emitting element 4 is different from the manufacturing process of the comparative light-emitting element 1 only in the manufacturing process of the light-emitting layer 140, and the other manufacturing processes are the same as the comparative light-emitting element 1. Since the element structures of the comparative light-emitting element 2, the comparative light-emitting element 3 and the light-emitting element 4 are shown in Table 2, the details of the manufacturing process are omitted. In addition, the light-emitting layer 140 of the comparative light-emitting element 2, the comparative light-emitting element 3 and the light-emitting element 4 is formed by vacuum evaporation in the same manner as the comparative light-emitting element 1.

[0637] The only difference in the element structure between the comparative light-emitting elements 1 to 3 and the light-emitting element 4 is the guest material used for the light-emitting layer 140. The other structures are the same. In addition, the light-emitting element 4 uses [Ir(pni-diBup)] of an organic compound of one embodiment of the present invention. 3 ], and the comparative light-emitting element 3 uses the comparative material fac-[Ir(pbi-diBup) 3 ]. In addition, as comparative light-emitting element 1 and comparative light-emitting element 2, [Ir(ppy) 3 ] and GD270 (manufactured by Jilin Aolaide Optoelectronic Materials Co., Ltd.).

[0638] <Characteristics of Light Emitting Element>

[0639] Next, the characteristics of the comparative light-emitting elements 1 to 3 and the light-emitting element 4 manufactured above were measured. A colorimeter (BM-5A manufactured by Topcon) was used for the measurement of brightness and CIE chromaticity, and a multi-channel spectrum analyzer (PMA-11 manufactured by Hamamatsu Photonics Co., Ltd.) was used for the measurement of electroemission spectrum.

[0640] Fig.19 The current efficiency-luminance characteristics of the comparative light-emitting elements 1 to 3 and the light-emitting element 4 are shown. Fig. 20 The current density-voltage characteristics are shown. Fig.21 The external quantum efficiency-brightness characteristics are shown. In addition, each light-emitting element was measured at room temperature (maintaining an atmosphere of 23°C). In addition, Fig. 22 Shown at 2.5 mA / cm 2 The emission spectrum when the current density causes current to flow through comparison light-emitting element 1 to comparison light-emitting element 3 and light-emitting element 4.

[0641] In addition, Table 3 shows that the 2 Element characteristics of the nearby comparative light-emitting elements 1 to 3 and 4.

[0642] [Table 3]

[0643]

[0644] In addition, by Fig. 22 It can be seen that the emission spectra of comparison light-emitting elements 1 to comparison light-emitting elements 3 and light-emitting element 4 have spectral peaks near 518nm, 523nm, 508nm and 500nm, respectively, and the half-maximum full widths are approximately 74nm, 73nm, 63nm and 27nm, respectively, and comparison light-emitting elements 1 to comparison light-emitting elements 3 and light-emitting element 4 can obtain light emission from the guest material included in each light-emitting element.

[0645] like Fig.19 As shown in Table 3, all of Comparative Light-Emitting Elements 1 to 3 and Light-Emitting Element 4 have high current efficiency. Although Light-Emitting Element 4 has an emission spectrum in a region with a lower luminous efficiency (short wavelength region) than Comparative Light-Emitting Elements 1 to 3, it has a current efficiency equal to that of Comparative Light-Emitting Elements 1 to 3. Fig.21 As shown in Table 3, the light emitting element 4 has an extremely high external quantum efficiency, which is more than 25%. In addition, the efficiency of the light emitting element 4 is higher than that of the light emitting element 5 using [Ir(ppy) 3 ] or GD270 is higher than that of the comparative light-emitting element 1 and the comparative light-emitting element 2. In addition, it can be seen that the light-emitting element 4 emits light at a shorter wavelength than the light-emitting element 3, but its external quantum efficiency is higher than that of the light-emitting element 3.

[0646] Depend on Fig. 20 As shown in Table 3, the comparative light-emitting elements 1 to 3 and the light-emitting element 4 all have good driving voltage characteristics.

[0647] [Example 7]

[0648] In this embodiment, a production example of a light-emitting element including an organic metal complex according to one embodiment of the present invention, which is different from that in Embodiment 6, and characteristics of the light-emitting element are described. Figure 1AThe stacked structure of the light emitting element manufactured in this example is shown. In addition, Table 4 shows the details of the element structure. In addition, the organic compounds used in this example are shown below. In addition, for other organic compounds, refer to other embodiments or examples.

[0649] [Chemical formula 70]

[0650]

[0651] [Table 4]

[0652]

[0653] 《Manufacturing of Light Emitting Element 5》

[0654] The light-emitting element 5 is formed by vacuum evaporation in the same manner as the comparative light-emitting elements 1 to 3 and the light-emitting element 4. Since the element structure of the light-emitting element 5 is shown in Table 4, the details of the manufacturing process are omitted. The light-emitting element 5 is a light-emitting element using a heterogeneous organic metal complex (a metal complex including two or more ligands) of one embodiment of the present invention.

[0655] <Characteristics of Light Emitting Element>

[0656] Next, the characteristics of the light emitting element 5 manufactured as described above were measured. The measurement conditions of the light emitting element were the same as those in the above-described embodiment.

[0657] Fig.23 The current efficiency-luminance characteristics of the light emitting element 5 are shown. Fig.24 The current density-voltage characteristics are shown. Fig.25 The external quantum efficiency-brightness characteristics are shown. Fig.26 Shown at 2.5 mA / cm 2 The emission spectrum when the current density causes the current to flow through the light-emitting element 5.

[0658] In addition, Table 5 shows that the 2 Element characteristics of the light emitting element 5 nearby.

[0659] [Table 5]

[0660]

[0661] In addition, by Fig.26 It can be seen that the emission spectrum of light-emitting element 5 has a spectral peak near 523nm, a full width at half maximum of about 63nm, and light-emitting element 5 can obtain light from the guest material [Ir(pni-diBup) 2 (mdppy)] luminescence.

[0662] like Fig.23, Fig.25 As shown in Table 5, the light emitting element 5 has high current efficiency and high external quantum efficiency. In particular, the external quantum efficiency is extremely high, that is, exceeding 25%.

[0663] like Fig.24 As shown in Table 5, the light-emitting element 5 has good driving voltage characteristics.

[0664] Present light.

[0665] <Reliability of Light Emitting Components>

[0666] Next, a constant current driving test was performed on the light emitting element 5 at 2 mA. Fig. 27 The results are shown in Figure 2. Fig. 27 It can be seen that the LT of light emitting element 5 70 The (30% brightness reduction time) exceeded 100 hours, and the light-emitting element 5 had good reliability.

[0667] [Example 8]

[0668] In this embodiment, a production example of a light-emitting element including an organic metal complex according to one embodiment of the present invention, which is different from Embodiment 6 and Embodiment 7, and characteristics of the light-emitting element are described. Figure 1A The stacked structure of the light emitting element manufactured in this example is shown in Table 6. In addition, the details of the element structure are shown in Table 6.

[0669] [Table 6]

[0670]

[0671] 《Comparison of the manufacturing of light-emitting element 6 and light-emitting element 7》

[0672] Comparative light-emitting element 6 and light-emitting element 7 were prepared by vacuum deposition in the same manner as light-emitting element 5. The element structures of comparative light-emitting element 6 and light-emitting element 7 are shown in Table 6, and therefore the details of the manufacturing process are omitted. Light-emitting element 7 is a light-emitting element prepared by forming an organometallic complex [Ir(pni-diBuCNp) 3 ] is used as a guest material. In addition, comparative light-emitting element 6 is a light-emitting element using GD270 as a guest material.

[0673] <Characteristics of Light Emitting Element>

[0674] Next, the characteristics of the comparative light emitting element 6 and the light emitting element 7 manufactured above were measured. The measurement conditions of the light emitting elements were the same as those of the above-mentioned embodiment.

[0675] Fig.28 The current efficiency-luminance characteristics of the comparative light-emitting element 6 and the light-emitting element 7 are shown. Fig.29The current density-voltage characteristics are shown. Fig.30 The external quantum efficiency-brightness characteristics are shown. Fig.31 Shown at 2.5 mA / cm 2 The emission spectra of light-emitting element 6 and light-emitting element 7 are compared when a current density of a current is passed through the light-emitting element 6.

[0676] In addition, Table 7 shows that the 2 The device characteristics of the nearby comparative light emitting device 6 and the light emitting device 7 are shown.

[0677] [Table 7]

[0678]

[0679] In addition, by Fig.31 It can be seen that the emission spectra of the comparison light-emitting element 6 and the light-emitting element 7 have spectral peaks near 523nm and 510nm, respectively, and the half-maximum full width is about 68nm and 67nm, respectively, and the comparison light-emitting element 6 and the light-emitting element 7 can obtain the light emission from the guest material included in each light-emitting element.

[0680] like Fig.28 , Fig.30 As shown in Table 7, both the comparative light-emitting element 6 and the light-emitting element 7 have high current efficiency. Although the light-emitting element 7 has an emission spectrum in a region with a lower luminous efficiency (short wavelength region) than the comparative light-emitting element 6, it has a higher current efficiency than the comparative light-emitting element 6. Fig.30 As can be seen from Table 7, Light Emitting Element 7 has an extremely high external quantum efficiency, i.e., more than 25%. In addition, although Light Emitting Element 7 has light emission on the shorter wavelength side compared to Comparative Light Emitting Element 6 using GD270, which is widely used as a guest material, its current efficiency and external quantum efficiency are higher than those of Comparative Light Emitting Element 6.

[0681] Depend on Fig.29 As can be seen from Table 7, both the comparative light-emitting element 6 and the light-emitting element 7 have good driving voltage characteristics.

[0682] [Explanation of symbols]

[0683] 100: EL layer, 101: electrode, 102: electrode, 103: EL layer, 106: light-emitting unit, 108: light-emitting unit, 111: hole injection layer, 112: hole transport layer, 113: electron transport layer, 114: electron injection layer, 115: charge generation layer, 116: hole injection layer, 117: hole transport layer, 118: electron transport layer, 119: electron injection layer, 120: light-emitting layer, 140: light-emitting layer, 141: host material, 141_1: organic compound, 141_2: organic compound, 142: guest material, 150: light-emitting element, 152: light-emitting element, 170: light-emitting layer, 250: light-emitting element, 601: source side driving circuit, 602: image Element part, 603: gate side driving circuit, 604: sealing substrate, 605: sealing agent, 607: space, 608: wiring, 610: element substrate, 611: switching TFT, 612: current control, 613: electrode, 614: insulator, 616: EL layer, 617: electrode, 618: light emitting element, 623: n-channel TFT, 624: p-channel TFT, 900: portable information terminal, 901: casing, 902: casing, 903: display part, 905: hinge part, 910: portable information terminal, 911: casing, 912: display part, 913: operation button, 914: external connection port, 915: speaker, 916: microphone, 917: light camera, 920: camera, 921: housing, 922: display unit, 923: operation button, 924: shutter button, 926: lens, 1001: substrate, 1002: base insulating film, 1003: gate insulating film, 1006: gate electrode, 1007: gate electrode, 1008: gate electrode, 1020: interlayer insulating film, 1021: interlayer insulating film, 1022: electrode, 1024B: electrode, 1024G: electrode, 1024R: electrode, 1025B: lower electrode, 1025G: lower electrode, 1025R: lower electrode, 1026: partition wall, 1028: EL layer, 1029: electrode, 1031: sealing substrate, 1032: sealant, 1033: base material, 1034B: coloring layer, 1034G: coloring layer, 1034R: coloring layer, 1036: cover layer, 1037: interlayer insulating film, 1040: pixel portion, 1041: drive circuit portion, 1042: peripheral portion, 2100: robot, 2101: illumination sensor, 2102: microphone, 2103: upper camera, 2104: speaker, 2105: display, 2106: lower camera, 2107: obstacle sensor, 2108: moving mechanism, 2110: computing device, 3500: multi-function terminal, 3502: housing, 3504: display portion, 3506: camera, 3508: lighting, 3600: lamp, 3602: housing, 3608: lighting,3610: speaker, 5000: housing, 5001: display unit, 5002: display unit, 5003: speaker, 5004: LED light, 5005: operation key, 5006: connection terminal, 5007: sensor, 5008: microphone, 5012: support unit, 5013: earphone, 5100: sweeping robot, 5101: display, 5102: camera, 5103: brush, 5104: operation button, 5120: garbage, 51 40: Portable electronic device, 5150: Portable information terminal, 5151: Housing, 5152: Display area, 5153: Bending portion, 8501: Illuminating device, 8502: Illuminating device, 8503: Illuminating device, 8504: Illuminating device, 9000: Housing, 9001: Display portion, 9006: Connecting terminal, 9055: Hinge, 9200: Portable information terminal, 9201: Portable information terminal, 9202: Portable information terminal.

Claims

1. An organometallic complex having a structure represented by the general formula (G-7): in, R 1 To R 10 Each independently represents hydrogen or an alkyl group having 1 to 6 carbon atoms, R 11 To R 15 Each independently represents any one of hydrogen, an alkyl group having 1 to 6 carbon atoms and an electron withdrawing group, and the electron withdrawing group is any one of a halo group, a cyano group and a haloalkyl group.

2. An organic metal complex having a structure represented by the general formula (G-8): in, R 11 , R 13 and R 15 Each independently represents any one of hydrogen, an alkyl group having 1 to 6 carbon atoms and an electron withdrawing group, and the electron withdrawing group is any one of a halo group, a cyano group and a haloalkyl group.

3. An organic metal complex having a structure represented by the general formula (G-9): in, R 13 represents hydrogen or an electron withdrawing group, and the electron withdrawing group is any one of a halo group, a cyano group and a haloalkyl group.

4. An organic metal complex having a structure represented by the general formula (G-10): in, R 15 It represents hydrogen or an alkyl group having 1 to 6 carbon atoms.

5. An organometallic complex represented by the general formula (G-12), in, R 1 To R 10 Each independently represents hydrogen or an alkyl group having 1 to 6 carbon atoms, R 11 To R 15 Each independently represents any one of hydrogen, an alkyl group having 1 to 6 carbon atoms, and an electron-withdrawing group, wherein the electron-withdrawing group is any one of a halide, a cyano group, and a haloalkyl group, L represents a monoanionic ligand, and the monoanionic ligand is of the general formula (L4), R 32 To R 35 Each independently represents hydrogen or an alkyl group having 1 to 6 carbon atoms, A 4 To A 7 Each independently represents the sp bonded to hydrogen 2 Hybridized carbon or sp with substituents 2 hybridized carbon, the substituent is an alkyl group or a phenyl group having 1 to 6 carbon atoms, And n represents 1 or 2.

6. An organometallic complex represented by the general formula (G-13), in, R 11 , R 13 and R 15 Each independently represents any one of hydrogen, an alkyl group having 1 to 6 carbon atoms, and an electron-withdrawing group, wherein the electron-withdrawing group is any one of a halo group, a cyano group, and a haloalkyl group, L represents a monoanionic ligand, and the monoanionic ligand is of the general formula (L4), R 32 To R 35 Each independently represents hydrogen or an alkyl group having 1 to 6 carbon atoms, A 4 To A 7 Each independently represents the sp bonded to hydrogen 2 Hybridized carbon or sp with substituents 2 hybridized carbon, the substituent is an alkyl group or a phenyl group having 1 to 6 carbon atoms, And n represents 1 or 2.

7. An organometallic complex represented by the general formula (G-14), in, R 13 represents hydrogen or an electron-withdrawing group, wherein the electron-withdrawing group is any one of a halo group, a cyano group and a haloalkyl group, L represents a monoanionic ligand, and the monoanionic ligand is of the general formula (L4), R 32 To R 35 Each independently represents hydrogen or an alkyl group having 1 to 6 carbon atoms, A 4 To A 7 Each independently represents the sp bonded to hydrogen 2 Hybridized carbon or sp with substituents 2 hybridized carbon, the substituent is an alkyl group or a phenyl group having 1 to 6 carbon atoms, And n represents 1 or 2.

8. The organometallic complex according to claim 2 or 6, Where R 11 and R 15 Each independently represents an alkyl group having 1 to 6 carbon atoms.

9. The organometallic complex according to any one of claims 1 to 3 and claims 5 to 7, wherein the electron withdrawing group is a cyano group.

10. The organometallic complex according to any one of claims 1 to 7, The alkyl group is a branched alkyl group having 3 to 6 carbon atoms.

11. An organometallic complex represented by any one of the structural formulas (100) to (103):

12. A light emitting element, comprising: The EL layer between a pair of electrodes, The EL layer comprises the organometallic complex according to any one of claims 1 to 7 and 11.

13. A light emitting device, comprising: The light-emitting element according to claim 12; as well as At least one of a color filter and a transistor.

14. An electronic device comprising: The light emitting device according to claim 13; as well as At least one of the housing and the touch sensor.

15. A lighting device comprising the light emitting element according to claim 12; and At least one of the housing and the touch sensor.

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