Organic compound, mixture thereof, and method for synthesizing organic compound

Abstract

To provide a method for synthesizing an organic compound containing deuterium.SOLUTION: A method for synthesizing an organic compound, wherein, in General Formula (G1), Y represents oxygen or sulfur, R11 to R14 each independently represent any one of hydrogen (including deuterium), a hydroxyl group, an organoboron group, a boronic acid, an organotin group, or a halogen, X1 to X4 each independently represent carbon or nitrogen, and any one or two of X1 to X4 represent nitrogen, R15 to R18 each independently represent hydrogen (including deuterium), a hydroxyl group, an organoboron group, a boronic acid, an organotin group, or a halogen, and in the case where X1 to X4 each represent nitrogen, R15 to R18 bonded to the nitrogen each represent a vacancy, and at least one of R11 to R18 represents deuterium.SELECTED DRAWING: None

Description

[Technical Field]

[0001] One aspect of the present invention relates to a method for synthesizing an organic compound. It also relates to an organic compound, a light-emitting device, a light-emitting apparatus, an electronic device, and a lighting apparatus. However, one aspect of the present invention is not limited to the above technical fields. That is, one aspect of the present invention relates to an object, a method, a manufacturing method, or a driving method. Alternatively, one aspect of the present invention relates to a process, a machine, manufacture, or a composition of matter. Specific examples include semiconductor devices, display devices, and liquid crystal display devices. [Background technology]

[0002] Light-emitting devices (also called organic EL elements), which consist of an EL layer sandwiched between a pair of electrodes, have properties such as being thin and lightweight, having fast response to input signals, and low power consumption, making displays that use these elements highly useful for flat panel displays and the like.

[0003] Displays or lighting devices using light-emitting devices are suitable for use in a variety of electronic devices, and research and development is ongoing to find light-emitting devices with better efficiency and life span.

[0004] Although the characteristics of light-emitting devices have improved dramatically, they are still insufficient to meet the high demands for efficiency, durability, and other properties. In particular, to solve problems specific to EL, such as burn-in, it is desirable to minimize the decrease in efficiency due to degradation.

[0005] Degradation is largely dependent on the luminescent center substance and the materials around it, so there has been active development of host materials with good properties.

[0006] For example, a technology has been disclosed in which hydrogen atoms in a host material are replaced with deuterium atoms (deuteration) (Patent Document 1). Deuteration of a host material is effective in extending the life of a light-emitting device, but it complicates the synthesis route and significantly increases the cost of raw materials. It also has problems such as the need for high temperatures and pressures for synthesis. Furthermore, the purification process after the synthesis reaction is complicated, making it difficult to purify the deuterium-substituted organic compound, preventing high purity. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Special table number 2013-503860 Summary of the Invention [Problem to be solved by the invention]

[0008] An object of one embodiment of the present invention is to provide a method for deuterizing an organic compound. Another object of one embodiment of the present invention is to provide a method for synthesizing an organic compound by partially deuterizing the organic compound. Another object of one embodiment of the present invention is to provide an organic compound that can extend the lifetime of a light-emitting device by using a method for synthesizing an organic compound by selectively deuterizing a portion of the organic compound. Another object of one embodiment of the present invention is to perform molecular design that can reduce the complexity of the synthesis route and the synthesis conditions such as high temperature and high pressure, and to synthesize an organic compound molecularly designed in such a manner.

[0009] Another object of one embodiment of the present invention is to provide an organic compound that can be easily synthesized. Another object of one embodiment of the present invention is to provide a method for synthesizing a novel organic compound. Another object of one embodiment of the present invention is to provide a novel organic compound. Another object of one embodiment of the present invention is to provide an organic compound whose excited state is stable. Another object of one embodiment of the present invention is to provide an organic compound that can be used as a host material for dispersing a light-emitting substance. Another object of one embodiment of the present invention is to provide a light-emitting device with a long operating lifetime. Another object of one embodiment of the present invention is to provide a novel light-emitting device. Another object of one embodiment of the present invention is to reduce the manufacturing cost of a light-emitting device. Another object of one embodiment of the present invention is to provide a light-emitting device, electronic device, or lighting device with low power consumption.

[0010] Note that the description of these problems does not preclude the existence of other problems. Note that one embodiment of the present invention does not necessarily solve all of these problems. Note that problems other than these will become apparent from the description of the specification, drawings, claims, etc., and it is possible to extract other problems from the description of the specification, drawings, claims, etc.

[0011] Note that one embodiment of the present invention does not necessarily solve all of these problems. Note that problems other than these will become apparent from the description in the specification, drawings, claims, etc., and it is possible to extract problems other than these from the description in the specification, drawings, claims, etc. [Means for solving the problem]

[0012] One embodiment of the present invention is a method for synthesizing an organic compound, which is a method for obtaining an organic compound having deuterium.

[0013] That is, one embodiment of the present invention is a method for synthesizing an organic compound, in which an organic compound represented by general formula (G0) is reacted with a transition metal catalyst, heavy water, and hydrogen molecules to obtain an organic compound represented by general formula (G1).

[0014] [ka]

[0015] [ka]

[0016] In the general formula (G0) and the general formula (G1), Y represents oxygen or sulfur, and R 1 ~R 4 , and R 11 ~R 14 each independently represents one of hydrogen (including deuterium), a hydroxyl group, an organic boron group, a boronic acid, an organic tin group, or a halogen; X 1 ~X 4 each independently represents carbon or nitrogen, and X 1 ~X 4 Any one or two of R is nitrogen; 5 ~R 8 , and R 15 ~R 18 each independently represents hydrogen (including deuterium), a hydroxyl group, an organoboron group, a boronic acid, an organotin group, or a halogen; and X 1 ~X 4 is nitrogen, R bonded to the nitrogen 5 ~R 8 , and R 15 ~R 18 is vacant, and R 11 ~R 18 The total number of deuterium atoms to be substituted is R 1 ~R 8 is greater than the total number of deuterium atoms to be substituted.

[0017] Another embodiment of the present invention is a method for synthesizing an organic compound, comprising reacting an organic compound represented by General Formula (G0) with a transition metal catalyst, heavy water, and a hydrogen molecule donor to obtain an organic compound represented by General Formula (G1).

[0018] In the above embodiment, the hydrogen molecular donor is formic acid, ammonia borane, or methanol, or 2-propanol.

[0019] In the above embodiment, the transition metal catalyst contains a platinum group element.

[0020] Another embodiment of the present invention is an organic compound represented by General Formula (G1).

[0021] [ka]

[0022] In the above general formula (G1), R 11 ~R 14 Each independently represents one of hydrogen (including deuterium), a hydroxyl group, or a halogen. 1 ~X 4 each independently represents carbon or nitrogen, and X 1 ~X 4 One or two of R is nitrogen. 15 ~R 18 each independently represents hydrogen (including deuterium), a hydroxyl group, or a halogen, and X 1 ~X 4 If is nitrogen, R bonded to the nitrogen 15 ~R 18 represents a vacant position. Y represents oxygen or sulfur. 11 ~R 18 At least one of the atoms is deuterium.

[0023] Another embodiment of the present invention is an organic compound represented by structural formula (100).

[0024] [ka]

[0025] Alternatively, it is an organic compound represented by structural formula (100), an organic compound represented by structural formula (100-1), or a mixture thereof.

[0026] [ka]

[0027] Another embodiment of the present invention is an electronic device including a light-emitting device or a light-receiving device including any of the above organic compounds, and a sensor, an operation button, a speaker, or a microphone.

[0028] Another embodiment of the present invention is a lighting device including a light-emitting device or a light-receiving device including any of the above organic compounds, and a housing. [Effects of the Invention]

[0029] According to one embodiment of the present invention, a method for deuterizing an organic compound can be provided. Furthermore, according to one embodiment of the present invention, a method for synthesizing an organic compound by selectively deuterizing a portion of the organic compound can be provided. Furthermore, according to one embodiment of the present invention, an organic compound that can extend the lifetime of a light-emitting device can be provided by using a method for synthesizing an organic compound by selectively deuterizing a portion of the organic compound. As a result, it is possible to reduce the complexity of the synthesis route, the amount or type of reagents used, and high-temperature and high-pressure conditions in the synthesis route, which are encountered when all or part of the hydrogen in an organic compound is replaced with deuterium.

[0030] According to one embodiment of the present invention, an organic compound that can be easily synthesized can be provided. According to one embodiment of the present invention, a synthesis method for a novel organic compound can be provided. According to one embodiment of the present invention, a novel organic compound can be provided. According to one embodiment of the present invention, a synthesis method for a stable organic compound that is unlikely to undergo a reaction from an excited state can be provided. According to one embodiment of the present invention, an organic compound that can be used in a light-emitting device can be provided. According to one embodiment of the present invention, an organic compound that can be used in an light-emitting layer of a light-emitting device can be provided. According to one embodiment of the present invention, an organic compound that can be used in a carrier-transport layer of a light-emitting device can be provided. According to one embodiment of the present invention, a novel light-emitting device can be provided. According to one embodiment of the present invention, a light-emitting device with a long operating lifetime can be provided. According to one embodiment of the present invention, the manufacturing cost of a light-emitting device can be reduced. According to one embodiment of the present invention, a light-emitting device, electronic device, or lighting device with low power consumption can be provided.

[0031] Note that the description of these effects does not preclude the existence of other effects. Note that one embodiment of the present invention does not necessarily have all of these effects. Note that effects other than these will become apparent from the description in the specification, drawings, claims, etc., and it is possible to extract other effects from the description in the specification, drawings, claims, etc. [Brief explanation of the drawings]

[0032] [Figure 1] 1(A) and 1(B) are diagrams illustrating a light-emitting device. [Figure 2] 2(A) and 2(B) are diagrams showing a light-emitting device. [Figure 3] 3(A) and 3(B) are diagrams showing a light-emitting device. [Figure 4] 4(A) and 4(B) are perspective views showing configuration examples of a display module. [Figure 5]5(A) and 5(B) are cross-sectional views showing examples of the configuration of a display device. [Figure 6] FIG. 6 is a perspective view showing an example of the configuration of a display device. [Figure 7] FIG. 7 is a cross-sectional view showing an example of the configuration of a display device. [Figure 8] FIG. 8 is a cross-sectional view showing an example of the configuration of a display device. [Figure 9] 9A to 9C are cross-sectional views and top views showing a structural example of a display device. [Figure 10] FIG. 10 is a cross-sectional view showing an example of the configuration of a display device. [Figure 11] 11A to 11C are cross-sectional views and top views showing a structural example of a display device. [Figure 12] FIG. 12 shows the 1H NMR spectrum of an organic compound. [Figure 13] FIG. 13 shows the 13C NMR spectrum of an organic compound. [Figure 14] FIG. 14 shows the MS spectrum of an organic compound. DETAILED DESCRIPTION OF THE INVENTION

[0033] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. However, the present invention is not limited to the following description, and various changes in form and details are possible without departing from the spirit and scope of the present invention. Therefore, the present invention should not be interpreted as being limited to the description of the embodiments shown below.

[0034] For ease of understanding, the position, size, range, etc. of each component shown in the drawings may not represent the actual position, size, range, etc. Therefore, the disclosed invention is not necessarily limited to the position, size, range, etc. disclosed in the drawings, etc.

[0035] In addition, in this specification and the like, when describing the configuration of the invention using drawings, the same reference numerals are used in common between different drawings.

[0036] (Embodiment 1) In this embodiment, a synthesis method of an organic compound according to one embodiment of the present invention will be described. The organic compound according to one embodiment of the present invention is represented by the following general formula (G1).

[0037] [ka]

[0038] In the above general formula (G1), R 11 ~R 14 Each independently represents one of hydrogen (including deuterium), a hydroxyl group, or a halogen. 1 ~X 4 each independently represents carbon or nitrogen, and X 1 ~X 4 One or two of R is nitrogen. 15 ~R 18 each independently represents hydrogen (including deuterium), a hydroxyl group, or a halogen, and X 1 ~X 4 If is nitrogen, R bonded to the nitrogen 15 ~R 18 is vacant. Also, R 15 ~R 18 If R is a hydroxyl group, it may tautomerize to a ketone derivative. Y represents oxygen or sulfur. 11 ~R 18 At least one of the atoms is deuterium.

[0039] Hereinafter, an example of a method for synthesizing the organic compound represented by general formula (G1) above, which is one embodiment of the present invention, will be described.

[0040] The organic compound represented by the general formula (G1) can be synthesized by reacting the organic compound represented by the general formula (G0), a transition metal catalyst M, heavy water (DO), and hydrogen molecules (H), as shown in the following synthesis scheme (s-1).

[0041] Note that the heavy water (DO) that can be used in the following synthesis scheme (s-1) may contain water (HO) and semi-heavy water (DHO). When HO and DHO are contained, the purity of DO is preferably 99% or higher. Furthermore, the hydrogen molecules (H) may contain deuterium molecules (D) or hydrogen-deuterium molecules (DH).

[0042] Alternatively, in the following synthesis scheme (s-1), a hydrogen molecule donor (H2 generation source) capable of generating hydrogen molecules in the presence of a transition metal catalyst can be used instead of hydrogen molecules (H2). That is, an organic compound represented by general formula (G1) can be synthesized by reacting a hydrogen molecule donor capable of generating hydrogen molecules in the presence of a transition metal catalyst, such as formic acid or alcohols, an organic compound represented by general formula (G0), a transition metal catalyst M, and heavy water (DO).

[0043] For example, formic acid, ammonia borane, methanol, 2-propanol, etc. can be used as a hydrogen molecule donor capable of generating hydrogen molecules in the presence of a transition metal catalyst. 2-propanol is particularly suitable because it has high solubility in the substrate (G0) or the product (G1) and is neutral, and therefore has weak interaction with the substrate (G0) or the product (G1) in the reaction system.

[0044] [ka]

[0045] In the above synthesis scheme, in general formula (GO), R 1 ~R 4 are each independently hydrogen, (including deuterium), a hydroxyl group, an organoboron group, a boronic acid, an organotin group, or a halogen; and R 5 ~R 8each independently represents hydrogen (including deuterium), a hydroxyl group, an organic boron group, a boronic acid, an organic tin group, or a halogen. 1 ~X 4 each independently represents carbon or nitrogen, and X 1 ~X 4 One or two of the R groups in the general formula (G0) are nitrogen atoms. Y represents oxygen or sulfur atoms. 1 ~R 8 It is an organic compound in which at least one of the above is substituted with deuterium (also called deuterated).

[0046] Therefore, R 11 ~R 18 The total number of deuterium atoms in the 1 ~R 8 The total number of deuterium atoms in R 11 ~R 18 The deuteration ratio of each R is the corresponding R 1 ~R 8 The deuteration ratio of each R is higher than or equal to that of R. 1 and R 11 When comparing R 1 R than the deuteration rate of 11 The deuteration rate of R is higher 1 and R 11 The deuteration ratio of R is the same. 2 and R 12 , R 3 and R 13 , R 4 and R 14 , R 5 and R 15 , R 6 and R 16 , R 7 and R 17 , or R 8 and R 18 When comparing the deuteration rates for R 1 and R 11 As in the case of 12 , R 13 , R 14 , R 15, R 16 , R 17 , and R 18 is high.

[0047] In addition, in the organic compound represented by the general formula (G0) or the general formula (G1), R 1 ~R 8 , and R 11 ~R 18 When is a halogen, it is preferably iodine, bromine, or chlorine.

[0048] In particular, R 1 ~R 8 , and R 11 ~R 18 When R is a halogen, the halogen-carbon bond possessed by general formula (G1) is suitable as a substrate for a chemical reaction that forms a carbon-carbon bond, such as Suzuki coupling. Therefore, when synthesizing a target compound using a compound represented by general formula (G1) as a substrate, R 1 ~R 8 , and R 11 ~R 18 However, when it is a halogen, it is preferable because a reaction for directly converting it into the target compound can be carried out.

[0049] In the synthesis scheme (s-1), the transition metal catalyst M represents a catalyst containing a transition metal element. Specifically, the transition metal element is preferably a platinum group element such as platinum (Pt), palladium (Pd), rhodium (Rh), iridium (Ir), or ruthenium (Ru). Heavy water (DO) is used as the solvent and deuterium source. Hydrogen molecules (H) (including deuterium molecules (D) and hydrogen-deuterium molecules (DH)) can be used to activate the transition metal catalyst M. Instead of the hydrogen molecules, a compound that reacts with the transition metal catalyst M in the reaction system to generate hydrogen molecules can also be used.

[0050] By using the synthesis method of one embodiment of the present invention, an organic compound can be deuterated without undergoing an extremely high temperature of 200°C or higher or an extremely high pressure of 1 MPa or higher. Furthermore, stable organic compounds that do not readily undergo reaction can be easily deuterated. Specifically, in the synthesis method of one embodiment of the present invention, organic compounds can be directly converted into deuterated compounds under mild reaction conditions, such as a temperature of less than 200°C or a pressure of less than 1.0 MPa. Therefore, since a deuterated organic compound synthesized via a multi-step synthesis route is not used, the manufacturing cost of a light-emitting device can be reduced.

[0051] According to one embodiment of the present invention, a deuterated organic compound that can be used as a material for a light-emitting device can be provided at low cost. For example, when the deuterated organic compound has an electron-transport property, it can be used as a host material for an electron-transport layer, a light-emitting layer, a hole-blocking layer, or the like.

[0052] By using deuterated organic compounds as materials for light-emitting devices, it is possible to extend the operating life of the light-emitting devices. Therefore, deuterated organic compounds can provide light-emitting devices with long operating life, which can provide highly reliable electronic devices and contribute to reducing device costs for consumers. In addition, deuterated light-emitting materials tend to have improved luminous efficiency, making it possible to provide light-emitting devices, electronic devices, or lighting devices with low power consumption.

[0053] <Example> Next, specific examples of the organic compound represented by the above general formula (G1) are shown below.

[0054] [ka]

[0055] The above structural formulas (100) and (101) are examples of organic compounds represented by general formula (G1); however, the organic compounds of one embodiment of the present invention are not limited thereto.

[0056] The organic compound represented by the structural formula (100) has a tautomer represented by the following structural formula (100-1), which exists in an equilibrium state as represented by the structural formula (100-2). Therefore, one embodiment of the present invention is a mixture containing the tautomers represented by the structural formula (100) and the structural formula (100-1).

[0057] [ka]

[0058] [ka]

[0059] This embodiment mode can be used in any combination with other embodiment modes and examples.

[0060] (Embodiment 2) In this embodiment, a light-emitting device according to one embodiment of the present invention will be described in detail.

[0061] 1 is a schematic diagram of a light-emitting device according to one embodiment of the present invention. The light-emitting device includes a first electrode 101 provided over an insulator 109, and an organic compound layer 103 between the first electrode 101 and a second electrode 102. The organic compound layer 103 includes at least a light-emitting layer 113 and an electron-injection layer 115. The light-emitting layer 113 contains a light-emitting substance and emits light when a voltage is applied between the first electrode 101 and the second electrode 102.

[0062] 1(A), the organic compound layer 103 preferably has functional layers such as a hole injection layer 111, a hole transport layer 112, and an electron transport layer 114 in addition to the light-emitting layer 113 and the electron injection layer 115. The organic compound layer 103 may also include functional layers other than those described above, such as a hole blocking layer, an exciton blocking layer, and an intermediate layer. Conversely, any of the layers described above may not be provided.

[0063] The organic compound layer 103 can be an organic compound synthesized using a deuterated intermediate by the synthesis method of Embodiment 1. By using a deuterated organic compound in a light-emitting device, the lifetime of the light-emitting device can be extended.

[0064] In the present embodiment, the first electrode 101 is an electrode including an anode, the second electrode 102 is an electrode including a cathode, and an example has been shown in which the first electrode 101 is formed on the insulator 109 side. However, the light-emitting device may have a so-called inverted stack structure in which the second electrode 102 is formed on the insulator 109 side. In this case, the light-emitting device has a stacked structure in the following order from the insulator 109 side: second electrode 102, electron injection layer 115, (electron transport layer 114), light-emitting layer 113, (hole transport layer 112, hole injection layer 111), and first electrode 101. In such a light-emitting device with an inverted stack structure, the relatively stable hole injection layer 111 is on the surface, and therefore the light-emitting device can have better reliability.

[0065] Furthermore, the first electrode 101 and the second electrode 102 may be formed as a single layer structure or a stacked layer structure, and in the case of a stacked layer structure, a layer in contact with the organic compound layer 103 functions as an anode or a cathode. In the case of a stacked layer structure, there is no restriction on the work function of layers other than the layer in contact with the organic compound layer 103, and materials may be selected depending on required properties such as resistance value, ease of processing, reflectance, light transmittance, and stability.

[0066] The anode is preferably formed using a metal, alloy, conductive compound, or mixture thereof having a large work function (specifically, 4.0 eV or higher). Specific examples include indium oxide-tin oxide (ITO), indium oxide-tin oxide containing silicon or silicon oxide (ITSO), indium oxide-zinc oxide, and indium oxide containing tungsten oxide and zinc oxide (IWZO). These conductive metal oxide films are usually formed by sputtering, but they may also be prepared by applying a sol-gel method. For example, indium oxide-zinc oxide can be formed by sputtering using a target in which 1 to 20 wt % of zinc oxide is added to indium oxide. Indium oxide containing tungsten oxide and zinc oxide (IWZO) can also be formed by sputtering using a target containing 0.5 to 5 wt% tungsten oxide and 0.1 to 1 wt% zinc oxide relative to indium oxide. Other materials that can be used for the anode include gold (Au), platinum (Pt), nickel (Ni), tungsten (W), chromium (Cr), molybdenum (Mo), iron (Fe), cobalt (Co), copper (Cu), palladium (Pd), titanium (Ti), aluminum (Al), and nitrides of metal materials (e.g., titanium nitride). A layer formed by stacking these materials can also be used as the anode. For example, a film formed by stacking Al, Ti, and ITSO on Ti in this order is preferred because of its high reflectivity, high efficiency, and the ability to achieve high resolution of several thousand ppi. Graphene can also be used as the anode material. In addition, by using a composite material capable of forming the hole injection layer 111 described later as a layer in contact with the anode (typically the hole injection layer), it becomes possible to select an electrode material regardless of the work function.

[0067] The hole injection layer 111 is provided in contact with the anode and has the function of facilitating the injection of holes into the organic compound layer 103. The hole injection layer 111 can be formed of a phthalocyanine-based compound or complex compound such as phthalocyanine (abbreviation: HPc) or copper phthalocyanine (abbreviation: CuPc), an aromatic amine compound such as 4,4′-bis[N-(4-diphenylaminophenyl)-N-phenylamino]biphenyl (abbreviation: DPAB) or 4,4′-bis(N-{4-[N′-(3-methylphenyl)-N′-phenylamino]phenyl}-N-phenylamino)biphenyl (abbreviation: DNTPD), or a polymer such as poly(3,4-ethylenedioxythiophene) / (polystyrenesulfonic acid) (abbreviation: PEDOT / PSS), or the like.

[0068] Alternatively, the hole injection layer 111 may be formed of a substance having electron acceptor properties. Examples of the substance having acceptor properties include organic compounds having an electron-withdrawing group (such as a halogen group or a cyano group), such as 7,7,8,8-tetracyano-2,3,5,6-tetrafluoroquinodimethane (abbreviation: F4-TCNQ), chloranil, 2,3,6,7,10,11-hexacyano-1,4,5,8,9,12-hexaazatriphenylene (abbreviation: HAT-CN), 1,3,4,5,7,8-hexafluorotetracyano-naphthoquinodimethane (abbreviation: F6-TCNNQ), and 2-(7-dicyanomethylene-1,3,4,5,6,8,9,10-octafluoro-7H-pyren-2-ylidene)malononitrile. In particular, compounds in which an electron-withdrawing group is bonded to a fused aromatic ring having multiple heteroatoms, such as HAT-CN, are preferred because of their thermal stability. Radialene derivatives having electron-withdrawing groups (especially halogen groups such as fluoro groups, cyano groups, etc.) are also preferred because of their extremely high electron-accepting properties. Specific examples include α,α',α''-1,2,3-cyclopropanetriylidenetris[4-cyano-2,3,5,6-tetrafluorobenzeneacetonitrile], α,α',α''-1,2,3-cyclopropanetriylidenetris[2,6-dichloro-3,5-difluoro-4-(trifluoromethyl)benzeneacetonitrile], and α,α',α''-1,2,3-cyclopropanetriylidenetris[2,3,4,5,6-pentafluorobenzeneacetonitrile]. As the substance having acceptor properties, in addition to the organic compounds described above, transition metal oxides such as molybdenum oxide, vanadium oxide, ruthenium oxide, tungsten oxide, and manganese oxide can be used.

[0069] The hole-injection layer 111 is preferably formed using a composite material containing the above-mentioned material having an acceptor property and an organic compound having a hole-transport property.

[0070] As the organic compound having hole transport properties used in the composite material, various organic compounds can be used, such as aromatic amine compounds, heteroaromatic compounds, aromatic hydrocarbons, and polymer compounds (oligomers, dendrimers, polymers, etc.). Note that the organic compound having hole transport properties used in the composite material can be 1×10 -6 cm 2 Preferably, the organic compound has a hole mobility of 1 / Vs or more. The organic compound having hole transport properties used in the composite material is preferably a compound having a fused aromatic hydrocarbon ring or a π-electron-rich heteroaromatic ring. As the fused aromatic hydrocarbon ring, an anthracene ring, a naphthalene ring, or the like is preferred. Furthermore, as the π-electron-rich heteroaromatic ring, a fused aromatic ring containing at least one of a pyrrole skeleton, a furan skeleton, and a thiophene skeleton is preferred, and specifically, a carbazole ring, a dibenzothiophene ring, or a ring in which an aromatic ring or a heteroaromatic ring is further fused to the above ring is preferred.

[0071] In addition, in a composite material containing the above-mentioned material having acceptor properties and an organic compound having hole transport properties, the interaction between the materials occurs efficiently. Therefore, the spin density measured by electron spin resonance (ESR) of a film containing the composite material shows that the spin density resulting from a signal observed at a g value of around 2.00 is 1×10 17 spins / cm 3 The above is preferable.

[0072] Such organic compounds having hole-transporting properties preferably have a carbazole skeleton, a dibenzofuran skeleton, a dibenzothiophene skeleton, or an anthracene skeleton. In particular, aromatic amines having a substituent containing a dibenzofuran ring or a dibenzothiophene ring, aromatic monoamines having a naphthalene ring, or aromatic monoamines in which a 9-fluorenyl group is bonded to the nitrogen of the amine via an arylene group may be used. It is preferable that these organic compounds having hole-transporting properties are substances having an N,N-bis(4-biphenyl)amino group, since this allows the fabrication of light-emitting devices with long lifetimes.

[0073] Specific examples of organic compounds having hole transport properties as described above include N-(4-biphenyl)-6,N-diphenylbenzo[b]naphtho[1,2-d]furan-8-amine (abbreviation: BnfABP), N,N-bis(4-biphenyl)-6-phenylbenzo[b]naphtho[1,2-d]furan-8-amine (abbreviation: BBABnf), 4,4'-bis(6-phenylbenzo[b]naphtho[1,2-d]furan-8-yl)-4''-phenyltriphenylamine (abbreviation: BnfBB1BP), N,N-bis(4-biphenyl)benzylamine (abbreviation: BnfBB1BP), and N,N-bis(4-biphenyl)benzylamine (abbreviation: BnfBB1BP). N,N-bis(4-biphenyl)benzo[b]naphtho[1,2-d]furan-6-amine (abbreviation: BBABnf(6)), N,N-bis(4-biphenyl)benzo[b]naphtho[1,2-d]furan-8-amine (abbreviation: BBABnf(8)), N,N-bis(4-biphenyl)benzo[b]naphtho[2,3-d]furan-4-amine (abbreviation: BBABnf(II)(4)), N,N-bis[4-(dibenzofuran-4-yl)phenyl]-4-amino-p-terphenyl (abbreviation: DBfBB1TP), N-[4-(dibenzothiophen-4-yl)phenyl]-4-amino-p-terphenyl] ]-N-phenyl-4-biphenylamine (abbreviation: ThBA1BP), 4-(2-naphthyl)-4',4''-diphenyltriphenylamine (abbreviation: BBAβNB), 4-[4-(2-naphthyl)phenyl]-4',4''-diphenyltriphenylamine (abbreviation: BBAβNBi), 4,4'-diphenyl-4''-(6;1'-binaphthyl-2-yl)triphenylamine (abbreviation: BBAαNβNB), 4,4'-diphenyl-4''-(7;1'-binaphthyl-2-yl)triphenylamine (abbreviation: BBAαNβ NB-03), 4,4'-diphenyl-4''-(7-phenyl)naphthyl-2-yltriphenylamine (abbreviation: BBAPβNB-03), 4,4'-diphenyl-4''-(6;2'-binaphthyl-2-yl)triphenylamine (abbreviation: BBA(βN2)B), 4,4'-diphenyl-4''-(7;2'-binaphthyl-2-yl)triphenylamine (abbreviation: BBA(βN2)B-03), 4,4'-diphenyl-4''-(4;2'-binaphthyl-1-yl)triphenylamine (abbreviation: BBAβNαNB), 4,4'-Diphenyl-4''-(5;2'-binaphthyl-1-yl)triphenylamine (abbreviation: BBAβNαNB-02), 4-(4-biphenylyl)-4'-(2-naphthyl)-4''-phenyltriphenylamine (abbreviation: TPBiAβNB), 4-(3-biphenylyl)-4'-[4-(2-naphthyl)phenyl]-4''-phenyltriphenylamine (abbreviation: mTPBiAβNBi), 4-(4-biphenylyl)-4'-[4-(2-naphthyl)phenyl] 4'-[4'-(3-phenyl-9H-carbazol-9-yl)biphenyl-4-yl]-4''-phenyltriphenylamine (abbreviated as TPBiAβNBi), 4-phenyl-4'-(1-naphthyl)triphenylamine (abbreviated as αNBA1BP), 4,4'-bis(1-naphthyl)triphenylamine (abbreviated as αNBB1BP), 4,4'-diphenyl-4''-[4'-(carbazol-9-yl)biphenyl-4-yl]triphenylamine (abbreviated as YGTBi1BP), 4'-[4-(3-phenyl-9H-carbazol-9-yl)furan N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-N-[4-(1-naphthyl)phenyl]-9,9'-spirobi[9H-fluorene]-2-amine (abbreviation: PCBNBSF), N,N- Bis(biphenyl-4-yl)-9,9'-spirobi[9H-fluorene]-2-amine (abbreviation: BBASF), N,N-bis(biphenyl-4-yl)-9,9'-spirobi[9H-fluorene]-4-amine (abbreviation: BBASF(4)), N-(biphenyl-2-yl)-N-(9,9-dimethyl-9H-fluoren-2-yl)-9,9'-spirobi[9H-fluorene]-4-amine (abbreviation: oFBiSF), N-(biphenyl-4-yl)-N-(9,9-dimethyl-9H-fluoren-2-yl)dibenzofuran-4-amine (abbreviation: FrBiF), N-[4-(1-naphthyl)phenyl]-N-[3-(6-phenyldibenzofuran-4-yl)phenyl]-1-naphthylamine (abbreviation: mPDBfBNBN), 4-phenyl-4'-(9-phenylfluoren-9-yl)triphenylamine (abbreviation: BPAFLP), 4-phenyl-3'-(9-phenylfluoren-9-yl)triphenylamine (abbreviation: mBPAFLP), 4-phenyl-4' -[4-(9-phenylfluoren-9-yl)phenyl]triphenylamine (abbreviation: BPAFLBi), 4-phenyl-4'-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBA1BP), 4,4'-diphenyl-4''-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBBi1BP), 4-(1-naphthyl)-4'-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBANB), 4,4'- Di(1-naphthyl)-4''-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBNBB), N-phenyl-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-9,9'-spirobi[9H-fluoren]-2-amine (abbreviation: PCBASF), N-(biphenyl-4-yl)-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-9,9-dimethyl-9H-fluoren-2-amine (abbreviation: PCBBiF), N,N-bis( Examples of such amines include N,N-bis(9,9-dimethyl-9H-fluoren-2-yl)-9,9'-spirobi-9H-fluoren-4-amine, N,N-bis(9,9-dimethyl-9H-fluoren-2-yl)-9,9'-spirobi-9H-fluoren-3-amine, N,N-bis(9,9-dimethyl-9H-fluoren-2-yl)-9,9'-spirobi-9H-fluoren-2-amine, and N,N-bis(9,9-dimethyl-9H-fluoren-2-yl)-9,9'-spirobi-9H-fluoren-1-amine.

[0074] In addition, other aromatic amine compounds such as N,N'-di(p-tolyl)-N,N'-diphenyl-p-phenylenediamine (abbreviation: DTDPPA), 4,4'-bis[N-(4-diphenylaminophenyl)-N-phenylamino]biphenyl (abbreviation: DPAB), 4,4'-bis(N-{4-[N'-(3-methylphenyl)-N'-phenylamino]phenyl}-N-phenylamino)biphenyl (abbreviation: DNTPD), and 1,3,5-tris[N-(4-diphenylaminophenyl)-N-phenylamino]benzene (abbreviation: DPA3B) can also be used as organic compounds having hole transport properties.

[0075] By forming the hole injection layer 111, the hole injection property becomes good, and a light emitting device with a low driving voltage can be obtained.

[0076] Among substances having acceptor properties, organic compounds having acceptor properties are easy to use because they can be easily vapor-deposited and formed into a film.

[0077] The hole transport layer 112 is formed by containing an organic compound having a hole transport property. -6 cm 2 It is preferable that the hole mobility is / Vs or more.

[0078] Examples of the organic compound having hole transport properties include 4,4'-bis[N-(1-naphthyl)-N-phenylamino]biphenyl (abbreviation: NPB), N,N'-diphenyl-N,N'-bis(3-methylphenyl)-4,4'-diaminobiphenyl (abbreviation: TPD), N,N'-bis(9,9'-spirobi[9H-fluoren]-2-yl)-N,N'-diphenyl-4,4'-diaminobiphenyl (abbreviation: BSPB), 4-phenyl-4'-(9-phenylfluoren-9-yl)triphenylamine (abbreviation: BPAFLP), 4-phenyl- 3'-(9-phenylfluoren-9-yl)triphenylamine (abbreviated as mBPAFLP), 4-phenyl-4'-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviated as PCBA1BP), 4,4'-diphenyl-4''-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviated as PCBBi1BP), 4-(1-naphthyl)-4'-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviated as PCBANB), 4,4'-di(1-naphthyl)-4''-(9-phenyl)triphenylamine (abbreviated as PCBANB), Compounds with an aromatic amine skeleton, such as 9,9-dimethyl-N-phenyl-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]fluoren-2-amine (abbreviation: PCBAF), and N-phenyl-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-9,9'-spirobi[9H-fluorene]-2-amine (abbreviation: PCBASF), 1,3-bis(N-carbazolyl)benzene (abbreviation: mCP), 4,4'-di(N-carbazolyl)benzene, and Bis(biphenyl-3-yl)-3,3'-bi-9H-carbazole (abbreviated as BismBPCz), 9-(biphenyl-3-yl)-9'-(biphenyl-4-yl)-9H,9'H-3,3'-bicarbazole (abbreviated as CzTP), 9,9'-diphenyl-9H,9'H-3,3'-bicarbazole (abbreviated as PCCP), 9,9'-bis(biphenyl-4-yl)-3,3'-bi-9H-carbazole (abbreviated as BisBPCz), 9,9'-bis(biphenyl-3-yl)-3,3'-bi-9H-carbazole (abbreviated as BismBPCz), 9-(biphenyl-3-yl)-9'-(biphenyl-4-yl)-9H,9'H-3,3'-Bicarbazole (abbreviation: mBPCCBP), 9-(2-naphthyl)-9'-phenyl-3,3'-bi-9H-carbazole (abbreviation: βNCCP), 9-(3-biphenyl)-9'-(2-naphthyl)-3,3'-bi-9H-carbazole (abbreviation: βNCCmBP), 9-(4-biphenyl)-9'-(2-naphthyl)-3,3'-bi-9H-carbazole (abbreviation: βNCCBP), 9,9'-di-2-naphthyl-3,3'-9H,9'H-bicarbazole (abbreviation: BisβNCz), 9-(2-naphthyl)-9'-[1,1':4',1"-terf phenyl]-3-yl-3,3'-9H,9'H-bicarbazole, 9-(2-naphthyl)-9'-[1,1':3',1"-terphenyl]-3-yl-3,3'-9H,9'H-bicarbazole, 9-(2-naphthyl)-9'-[1,1':3',1"-terphenyl]-5'-yl-3,3'-9H,9'H-bicarbazole, 9-(2-naphthyl)-9'-[1,1':4',1"-terphenyl]-4-yl-3,3'-9H,9'H-bicarbazole, 9-(2-naphthyl)-9'-[1,1':3',1"-terphenyl]-4-yl-3,3 '-9H,9'H-Bicarbazole, 9-(2-naphthyl)-9'-(triphenylen-2-yl)-3,3'-9H,9'H-bicarbazole, 9-phenyl-9'-(triphenylen-2-yl)-3,3'-9H,9'H-bicarbazole (abbreviation: PCCzTp), 9,9'-bis(triphenylen-2-yl)-3,3'-9H,9'H-bicarbazole, 9-(4-biphenyl)-9'-(triphenylen-2-yl)-3,3'-9H,9'H-bicarbazole, 9-(triphenylen-2-yl)-9'-[1,1':3',1"-taphe compounds having a carbazole skeleton such as [4-yl-3,3'-9H,9'H-bicarbazole]; compounds having a thiophene skeleton such as 4,4',4''-(benzene-1,3,5-triyl)tri(dibenzothiophene) (abbreviation: DBT3P-II), 2,8-diphenyl-4-[4-(9-phenyl-9H-fluoren-9-yl)phenyl]dibenzothiophene (abbreviation: DBTFLP-III), and 4-[4-(9-phenyl-9H-fluoren-9-yl)phenyl]-6-phenyldibenzothiophene (abbreviation: DBTFLP-IV);Examples of the compounds include compounds having a furan skeleton, such as 4',4''-(benzene-1,3,5-triyl)tri(dibenzofuran) (abbreviation: DBF3P-II) and 4-{3-[3-(9-phenyl-9H-fluoren-9-yl)phenyl]phenyl}dibenzofuran (abbreviation: mmDBFFLBi-II). Among the compounds mentioned above, compounds having an aromatic amine skeleton and compounds having a carbazole skeleton are preferred because they have good reliability, high hole transport properties, and contribute to reducing driving voltage. Note that the substances listed as organic compounds having hole transport properties used in the composite material of the hole injection layer 111 can also be suitably used as materials for the hole transport layer 112.

[0079] The light-emitting layer 113 is a layer containing a light-emitting substance, and preferably contains a light-emitting substance and a host material. Note that the light-emitting layer 113 may also contain other materials. Alternatively, the light-emitting layer 113 may be a stack of two layers with different compositions.

[0080] The light-emitting material may be a fluorescent material, a phosphorescent material, a material that exhibits thermally activated delayed fluorescence (TADF), or any other light-emitting material.

[0081] Examples of materials that can be used as fluorescent materials in the light-emitting layer include the following: In addition, fluorescent materials other than these can also be used.

[0082] 5,6-bis[4-(10-phenyl-9-anthryl)phenyl]-2,2'-bipyridine (abbreviation: PAP2BPy), 5,6-bis[4'-(10-phenyl-9-anthryl)biphenyl-4-yl]-2,2'-bipyridine (abbreviation: PAPP2BPy), N,N'-diphenyl-N,N'-bis[4-(9-phenyl-9H-fluoren-9-yl)phenyl]pyrene-1,6-diamine (abbreviation: 1,6FLPAPrn), N,N'-bis(3-methylphenyl)-N,N'-bis[3-(9-phenyl-9H-fluoren-9-yl)phenyl]pyrene-1,6-diamine )phenyl]pyrene-1,6-diamine (abbreviation: 1,6mMemFLPAPrn), N,N'-bis[4-(9H-carbazol-9-yl)phenyl]-N,N'-diphenylstilbene-4,4'-diamine (abbreviation: YGA2S), 4-(9H-carbazol-9-yl)-4'-(10-phenyl-9-anthryl)triphenylamine (abbreviation: YGAPA), 4-(9H-carbazol-9-yl)-4'-(9,10-diphenyl-2-anthryl)triphenylamine (abbreviation: 2YGAPPA), N,9-diphenyl-N-[4-( 10-phenyl-9-anthryl)phenyl]-9H-carbazol-3-amine (abbreviation: PCAPA), perylene, 2,5,8,11-tetra-tert-butylperylene (abbreviation: TBP), 4-(10-phenyl-9-anthryl)-4'-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBAPA), N,N''-(2-tert-butylanthracene-9,10-diyldi-4,1-phenylene)bis(N,N',N'-triphenyl-1,4-phenylenediamine) (abbreviation: DPABPA), N,9 -diphenyl-N-[4-(9,10-diphenyl-2-anthryl)phenyl]-9H-carbazol-3-amine (abbreviated as 2PCAPPA), N-[4-(9,10-diphenyl-2-anthryl)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-anthryl)-N,9-Diphenyl-9H-carbazol-3-amine (abbreviation: 2PCAPA), N-[9,10-bis(biphenyl-2-yl)-2-anthryl]-N,9-diphenyl-9H-carbazol-3-amine (abbreviation: 2PCABPhA), N-(9,10-diphenyl-2-anthryl)-N,N',N'-triphenyl-1,4-phenylenediamine (abbreviation: 2DPAPA), N-[9,10-bis(biphenyl-2-yl)-2-anthryl]-N,N',N'-triphenyl-1,4-phenylenediamine (abbreviation: 2DPABPhA) , 9,10-bis(biphenyl-2-yl)-N-[4-(9H-carbazol-9-yl)phenyl]-N-phenylanthracen-2-amine (abbreviation: 2YGABPhA), N,N,9-triphenylanthracen-9-amine (abbreviation: DPhAPhA), Coumarin 545T, N,N'-diphenylquinacridone (abbreviation: DPQd), rubrene, 5,12-bis(biphenyl-4-yl)-6,11-diphenyltetracene (abbreviation: BPT), 2-(2-{2-[4-(dimethylamino)phenyl]ethenyl}-6-methyl-4H-pyra N,N,N',N'-tetrakis(4-methylphenyl)acenaphtho[1,2-a]fluoranthene-3,10-diamine (abbreviation: p-mPhTD), 2-{2-methyl-6-[2-(2,3,6,7-tetrahydro-1H,5H-benzo[ij]quinolizin-9-yl)ethenyl]-4H-pyran-4-ylidene}propanedinitrile (abbreviation: DCM1), 2-{2-methyl-6-[2-(2,3,6,7-tetrahydro-1H,5H-benzo[ij]quinolizin-9-yl)ethenyl]-4H-pyran-4-ylidene}propanedinitrile (abbreviation: DCM2), N,N,N',N'-tetrakis(4-methylphenyl)tetracene-5,11-diamine (abbreviation: p-mPhTD), 7,14-diphenyl-N,N,N',N'-tetrakis(4-methylphenyl)acenaphtho[1,2-a]fluoranthene-3,10-diamine (abbreviation: p-mPhTD), Name: p-mPhAFD), 2-{2-isopropyl-6-[2-(1,1,7,7-tetramethyl-2,3,6,7-tetrahydro-1H,5H-benzo[ij]quinolizin-9-yl)ethenyl]-4H-pyran-4-ylidene}propanedinitrile (abbreviation: DCJTI), 2-{2-tert-butyl-6-[2-(1,1,7,7-tetramethyl-2,3,6,7-tetrahydro-1H,5H-benzo[ij]quinolizin-9-yl)ethenyl]-4H-pyran-4-ylidene}propanedinitrile (abbreviation: DCJTB),6-Bis{2-[4-(dimethylamino)phenyl]ethenyl}-4H-pyran-4-ylidene)propanedinitrile (abbreviation: BisDCM), 2-{2,6-bis[2-(8-methoxy-1,1,7,7-tetramethyl-2,3,6,7-tetrahydro-1H,5H-benzo[ij]quinolizin-9-yl)ethenyl]-4H-pyran-4-ylidene}propanedinitrile (abbreviation: BisDCJTM), N,N'-diphenyl-N,N'-(1,6-pyren-diyl)bis[(6-phenylbenzo[b]naphtho]] Examples include N,N'-diphenyl-N,N'-bis(9-phenyl-9H-carbazol-2-yl)naphtho[2,3-b;6,7-b']bisbenzofuran-3,10-diamine (abbreviation: 3,10PCA2Nbf(IV)-02), and 3,10-bis[N-(dibenzofuran-3-yl)-N-phenylamino]naphtho[2,3-b;6,7-b']bisbenzofuran (abbreviation: 3,10FrA2Nbf(IV)-02). In particular, condensed aromatic diamine compounds, such as pyrenediamine compounds 1,6FLPAPrn, 1,6mMemFLPAPrn, and 1,6BnfAPrn-03, are preferred because of their high hole-trapping properties and excellent luminous efficiency or reliability.

[0083] In addition, 5,9-diphenyl-5,9-diaza-13b-boranaphtho[3,2,1-de]anthracene (abbreviation: DABNA1), 9-[(1,1'-diphenyl)-3-yl]-N,N,5,11-tetraphenyl-5,9-dihydro-5,9-diaza-13b-boranaphtho[3,2,1-de]anthracene-3-amine (abbreviation: DABNA2), 2,12-di(tert-butyl)-5,9-di(4-tert-butylphenyl)-N,N-diphenyl-5H,9H-[1,4]benzazaborino[2,3,4-kl]phenaza Borin-7-amine (abbreviation: DPhA-tBu4DABNA), 2,12-di(tert-butyl)-N,N,5,9-tetra(4-tert-butylphenyl)-5H,9H-[1,4]benzazaborino[2,3,4-kl]phenazaborin-7-amine (abbreviation: tBuDPhA-tBu4DABNA), 2,12-di(tert-butyl)-5,9-di(4-tert-butylphenyl)-7-methyl-5H,9H-[1,4]benzazaborino[2,3,4-kl]phenazaborin (abbreviation: Me-tBu4DABNA), N 7 ,N 7 ,N 13 ,N 13 Fused heteroaromatic compounds containing nitrogen and boron, such as 5,9,11,15-octaphenyl-5H,9H,11H,15H-[1,4]benzazaborino[2,3,4-kl][1,4]benzazaborino[4',3',2':4,5][1,4]benzazaborino[3,2-b]phenazaborine-7,13-diamine (abbreviation: ν-DABNA) and 2-(4-tert-butylphenyl)benz[5,6]indolo[3,2,1-jk]benzo[b]carbazole (abbreviation: tBuPBibc), are particularly suitable for use as compounds having a diazaboranaphthoanthracene skeleton, since they have a narrow emission spectrum and can emit blue light with good color purity.

[0084] In addition to these, 9,10,11-tris[3,6-bis(1,1-dimethylethyl)-9H-carbazolyl-9-yl]-2,5,15,18-tetrakis(1,1-dimethylethyl)indolo[3,2,1-de]indolo[3',2',1':8,1][1,4]benzazaborino[2,3,4-kl]phenazaborine (abbreviation: BBCz-G), 9 ,11-bis[3,6-bis(1,1-dimethylethyl)-9H-carbazolyl-9-yl]-2,5,15,18-tetrakis(1,1-dimethylethyl)indolo[3,2,1-de]indolo[3',2',1':8,1][1,4]benzazaborino[2,3,4-kl]phenazaborine (abbreviation: BBCz-Y) and the like can be suitably used.

[0085] When a phosphorescent material is used as the light-emitting material in the light-emitting layer, examples of materials that can be used include the following.

[0086] Organometallic iridium complexes with a 4H-triazole skeleton, such as tris{2-[5-(2-methylphenyl)-4-(2,6-dimethylphenyl)-4H-1,2,4-triazol-3-yl-κN2]phenyl-κC}iridium(III) (abbreviation: [Ir(mpptz-dmp)3]) and tris(5-methyl-3,4-diphenyl-4H-1,2,4-triazolato)iridium(III) (abbreviation: [Ir(Mptz)3]), Organometallic iridium complexes with a 1H-triazole skeleton, such as tris[3-methyl-1-(2-methylphenyl)-5-phenyl-1H-1,2,4-triazolato]iridium(III) (abbreviation: [Ir(Mptz1-mp)3]) and tris(1-methyl-5-phenyl-3-propyl-1H-1,2,4-triazolato)iridium(III) (abbreviation: [Ir(Prptz1-Me)3]), and fac-tris[1-(2,6-diisopropyl) [Ir(iPrpim)3]), tris[3-(2,6-dimethylphenyl)-7-methylimidazo[1,2-f]phenanthridinato]iridium(III) (abbreviation: [Ir(dmpimpt-Me)3]), tris(2-{1-[2,6-bis(1-methylethyl)phenyl]-1H-imidazol-2-yl-κN3}-4-cyanophenyl organometallic iridium complexes with an imidazole skeleton, such as tris[(6-tert-butyl-3-phenyl-2H-imidazo[4,5-b]pyrazin-1-yl-κC2)phenyl-κC]iridium(III) (abbreviation: [Ir(cb)3]), and organometallic iridium complexes with a benzimidazolidene skeleton, such as tris[(6-tert-butyl-3-phenyl-2H-imidazo[4,5-b]pyrazin-1-yl-κC2)phenyl-κC]iridium(III) (abbreviation: [Ir(cb)3]). 2’ ]iridium(III) tetrakis(1-pyrazolyl)borate (abbreviation: FIr6), bis[2-(4',6'-difluorophenyl)pyridinato-N,C 2’ ]iridium(III) picolinate (abbreviation: FIrpic), bis{2-[3',5'-bis(trifluoromethyl)phenyl]pyridinato-N,C 2’}iridium(III) picolinate (abbreviation: [Ir(CF3ppy)2(pic)]), bis[2-(4',6'-difluorophenyl)pyridinato-N,C 2’ ] Organometallic iridium complexes with phenylpyridine derivatives bearing electron-withdrawing groups as ligands, such as iridium(III) acetylacetonate (abbreviated as FIracac), are compounds that exhibit blue phosphorescence and have an emission peak in the wavelength range from 450 nm to 520 nm.

[0087] Also, tris(4-methyl-6-phenylpyrimidinato)iridium(III) (abbreviation: [Ir(mppm)3]), tris(4-t-butyl-6-phenylpyrimidinato)iridium(III) (abbreviation: [Ir(tBuppm)3]), (acetylacetonato)bis(6-methyl-4-phenylpyrimidinato)iridium(III) (abbreviation: [Ir(mppm)2(acac)]), (acetylacetonato)bis(6-tert-butyl-4-phenylpyrimidinato)iridium(III) (abbreviation: [Ir(tBuppm)2(acac)]), (acetylacetonato)bis[6-(2-norbornyl)-4-phenylpyrimidinato]iridium(III) (abbreviation: [Ir(nbppm)2(acac)]), (acetylacetonato)bis[5-methyl-6- Organometallic iridium complexes with a pyrimidine skeleton, such as (2-methylphenyl)-4-phenylpyrimidinato]iridium(III) (abbreviation: [Ir(mpmppm)2(acac)]) and (acetylacetonato)bis(4,6-diphenylpyrimidinato)iridium(III) (abbreviation: [Ir(dppm)2(acac)]), organometallic iridium complexes with a pyrazine skeleton, such as (acetylacetonato)bis(3,5-dimethyl-2-phenylpyrazinato)iridium(III) (abbreviation: [Ir(mppr-Me)2(acac)]) and (acetylacetonato)bis(5-isopropyl-3-methyl-2-phenylpyrazinato)iridium(III) (abbreviation: [Ir(mppr-iPr)2(acac)]), and tris(2-phenylpyridinato-N,C 2’) Iridium(III) (abbreviation: [Ir(ppy)3]), bis(2-phenylpyridinato-N,C 2’ ) Iridium(III) acetylacetonate (abbreviation: [Ir(ppy)2(acac)]), bis(benzo[h]quinolinato)iridium(III) acetylacetonate (abbreviation: [Ir(bzq)2(acac)]), tris(benzo[h]quinolinato)iridium(III) (abbreviation: [Ir(bzq)3]), tris(2-phenylquinolinato-N,C 2’ ) Iridium(III) (abbreviation: [Ir(pq)3]), bis(2-phenylquinolinato-N,C 2’ ) Iridium(III) acetylacetonate (abbreviation: [Ir(pq)2(acac)]), [2-d3-methyl-8-(2-pyridinyl-κN)benzofuro[2,3-b]pyridine-κC]bis[2-(5-d3-methyl-2-pyridinyl-κN 2 )phenyl-κC]iridium(III) (abbreviation: [Ir(5mppy-d3)2(mbfpypy-d3)]), [2-d3-methyl-(2-pyridinyl-κN)benzofuro[2,3-b]pyridine-κC]bis[2-(2-pyridinyl-κN)phenyl-κC]iridium(III) (abbreviation: [Ir(ppy)2(mbfpypy-d3)]), [2-(4-d3-methyl-5-phenyl-2-pyridinyl-κN 2 )phenyl-κC]bis[2-(5-d3-methyl-2-pyridinyl-κN 2)phenyl-κC]iridium(III) (abbreviation: [Ir(5mppy-d3)2(mdppy-d3)]), [2-methyl-(2-pyridinyl-κN)benzofuro[2,3-b]pyridine-κC]bis[2-(2-pyridinyl-κN)phenyl-κC]iridium(III) (abbreviation: [Ir(ppy)2(mbfpypy)]), and [2-(4-methyl-5-phenyl-2-pyridinyl-κN)phenyl-κC]bis[2-(2-pyridinyl-κN)phenyl-κC]iridium(III) (abbreviation: [Ir(ppy)2(mdppy)]), as well as rare earth metal complexes such as tris(acetylacetonato)(monophenanthroline)terbium(III) (abbreviation: [Tb(acac)3(Phen)]). These compounds mainly exhibit green phosphorescence, with an emission peak in the wavelength range of 500 to 600 nm. Organometallic iridium complexes having a pyrimidine skeleton are particularly preferred because they are remarkably superior in reliability and luminous efficiency.

[0088] and organometallic iridium complexes having a pyrimidine skeleton, such as (diisobutyrylmethanato)bis[4,6-bis(3-methylphenyl)pyrimidinato]iridium(III) (abbreviation: [Ir(5mdppm)2(dibm)]), bis[4,6-bis(3-methylphenyl)pyrimidinato](dipivaloylmethanato)iridium(III) (abbreviation: [Ir(5mdppm)2(dpm)]), and bis[4,6-di(naphthalen-1-yl)pyrimidinato](dipivaloylmethanato)iridium(III) (abbreviation: [Ir(d1npm)2(dpm)]). Organometallic iridium complexes with a pyrazine skeleton, such as (acetylacetonato)bis(2,3,5-triphenylpyrazinato)iridium(III) (abbreviation: [Ir(tppr)2(acac)]), bis(2,3,5-triphenylpyrazinato)(dipivaloylmethanato)iridium(III) (abbreviation: [Ir(tppr)2(dpm)]), and (acetylacetonato)bis[2,3-bis(4-fluorophenyl)quinoxalinato]iridium(III) (abbreviation: [Ir(Fdpq)2(acac)]), tris(1-phenylisoquinolinato-N,C2’ ) Iridium(III) (abbreviation: [Ir(piq)3]), bis(1-phenylisoquinolinato-N,C 2’ ) iridium(III) acetylacetonate (abbreviated as [Ir(piq)2(acac)]), (3,7-diethyl-4,6-nonanedionato-κO4,κO6)bis[2,4-dimethyl-6-[7-(1-methylethyl)-1-isoquinolinyl-κN]phenyl-κC]iridium(III), and (3,7-diethyl-4,6-nonanedionato-κO4,κO6)bis[2,4-dimethyl-6-[5-(1-methylethyl)-2-quinolinyl-κN]phenyl-κC]iridium(III). In addition to iridium complexes, platinum complexes such as 2,3,7,8,12,13,17,18-octaethyl-21H,23H-porphyrin platinum(II) (abbreviated as PtOEP) and rare earth metal complexes such as tris(1,3-diphenyl-1,3-propanedionato)(monophenanthroline)europium(III) (abbreviated as [Eu(DBM)3(Phen)]) and tris[1-(2-thenoyl)-3,3,3-trifluoroacetonato](monophenanthroline)europium(III) (abbreviated as [Eu(TTA)3(Phen)]) are compounds that exhibit red phosphorescence, with peak emission in the wavelength range from 600 to 700 nm. Organometallic iridium complexes with a pyrazine skeleton also exhibit excellent red chromaticity.

[0089] In addition to the phosphorescent compounds described above, known phosphorescent compounds may be selected and used.

[0090] TADF materials include fullerene and its derivatives, acridine and its derivatives, eosin derivatives, etc. Also available are metal-containing porphyrins containing magnesium (Mg), zinc (Zn), cadmium (Cd), tin (Sn), platinum (Pt), indium (In), or palladium (Pd). Examples of the metal-containing porphyrin include protoporphyrin-tin fluoride complex (SnF2(Proto IX)), mesoporphyrin-tin fluoride complex (SnF2(Meso IX)), hematoporphyrin-tin fluoride complex (SnF2(Hemato IX)), coproporphyrin tetramethyl ester-tin fluoride complex (SnF2(Copro III-4Me)), octaethylporphyrin-tin fluoride complex (SnF2(OEP)), etioporphyrin-tin fluoride complex (SnF2(Etio I)), and octaethylporphyrin-platinum chloride complex (PtCl2OEP), all of which are shown in the following structural formulas.

[0091] [ka]

[0092] In addition, 2-(biphenyl-4-yl)-4,6-bis(12-phenylindolo[2,3-a]carbazol-11-yl)-1,3,5-triazine (abbreviation: PIC-TRZ), 9-(4,6-diphenyl-1,3,5-triazin-2-yl)-9'-phenyl-9H,9'H-3,3'-bicarbazole (abbreviation: PCCzTzn), 2-{4-[3-(N-phenyl-9H-carbazol-3-yl)-9H-carbazol-9-yl]phenyl}-4,6-diphenyl-1,3,5-triazine (abbreviation: PCCzPTzn), 2-[4-(10H-phenoxazin-10-yl)phenyl]-4,6-diphenyl-1,3,5-triazine (abbreviation: PCCzPTzn), and Heterocyclic compounds having one or both of a π-electron-rich heteroaromatic ring and a π-electron-deficient heteroaromatic ring, such as 3-[4-(5-phenyl-5,10-dihydrophenazin-10-yl)phenyl]-4,5-diphenyl-1,2,4-triazole (abbreviation: PPZ-3TPT), 3-(9,9-dimethyl-9H-acridin-10-yl)-9H-xanthen-9-one (abbreviation: ACRXTN), bis[4-(9,9-dimethyl-9,10-dihydroacridine)phenyl]sulfone (abbreviation: DMAC-DPS), and 10-phenyl-10H,10'H-spiro[acridin-9,9'-anthracene]-10'-one (abbreviation: ACRSA), can also be used. The heterocyclic compound has a π-electron-rich heteroaromatic ring and a π-electron-deficient heteroaromatic ring, and therefore has high electron transport and hole transport properties, and is therefore preferred. Among the skeletons having a π-electron-deficient heteroaromatic ring, pyridine skeleton, diazine skeleton (pyrimidine skeleton, pyrazine skeleton, pyridazine skeleton), and triazine skeleton are preferred because they are stable and reliable. In particular, benzofuropyrimidine skeleton, benzothienopyrimidine skeleton, benzofuropyrazine skeleton, and benzothienopyrazine skeleton are preferred because they have high acceptor properties and good reliability. Furthermore, among the skeletons having a π-electron-rich heteroaromatic ring, acridine skeleton, phenoxazine skeleton, phenothiazine skeleton, furan skeleton, thiophene skeleton, and pyrrole skeleton are preferred because they are stable and reliable.The furan skeleton is preferably a dibenzofuran skeleton, and the thiophene skeleton is preferably a dibenzothiophene skeleton. The pyrrole skeleton is particularly preferably an indole skeleton, a carbazole skeleton, an indolocarbazole skeleton, a bicarbazole skeleton, or a 3-(9-phenyl-9H-carbazol-3-yl)-9H-carbazole skeleton. Substances in which a π-electron-rich heteroaromatic ring and a π-electron-deficient heteroaromatic ring are directly bonded are particularly preferred because the electron-donating ability of the π-electron-rich heteroaromatic ring and the electron-accepting ability of the π-electron-deficient heteroaromatic ring are both enhanced, thereby reducing the energy difference between the S1 level and the T1 level, thereby enabling efficient thermally activated delayed fluorescence. Instead of the π-electron-deficient heteroaromatic ring, an aromatic ring bonded to an electron-withdrawing group such as a cyano group may be used. The π-electron-rich skeleton may be, for example, an aromatic amine skeleton or a phenazine skeleton. Examples of usable π-electron-deficient skeletons include a xanthene skeleton, a thioxanthene dioxide skeleton, an oxadiazole skeleton, a triazole skeleton, an imidazole skeleton, an anthraquinone skeleton, a boron-containing skeleton such as phenylborane or boranthrene, an aromatic ring having a nitrile group or a cyano group such as benzonitrile or cyanobenzene, a heteroaromatic ring, a carbonyl skeleton such as benzophenone, a phosphine oxide skeleton, a sulfone skeleton, etc. In this way, a π-electron-deficient skeleton and a π-electron-rich skeleton can be used in place of at least one of a π-electron-deficient heteroaromatic ring and a π-electron-rich heteroaromatic ring.

[0093] [ka]

[0094] TADF materials are materials with a small difference between the S1 and T1 levels, and have the ability to convert triplet excitation energy to singlet excitation energy through reverse intersystem crossing. Therefore, triplet excitation energy can be upconverted to singlet excitation energy (reverse intersystem crossing) using a small amount of thermal energy, allowing for efficient generation of a singlet excited state. Triplet excitation energy can also be converted into light emission.

[0095] Furthermore, exciplexes (also known as exciplexes), which form an excited state with two types of substances, have an extremely small difference between the S1 and T1 levels and function as TADF materials that can convert triplet excitation energy into singlet excitation energy.

[0096] Note that the phosphorescence spectrum observed at low temperatures (for example, 77 K to 10 K) can be used as an indicator of the T1 level. For a TADF material, when a tangent line is drawn at the base of the short wavelength side of the fluorescence spectrum and the energy of the wavelength of the extrapolated line is defined as the S1 level, and a tangent line is drawn at the base of the short wavelength side of the phosphorescence spectrum and the energy of the wavelength of the extrapolated line is defined as the T1 level, the difference between the S1 level and the T1 level is preferably 0.3 eV or less, and more preferably 0.2 eV or less.

[0097] When a TADF material is used as a light-emitting material, the S1 level of the host material is preferably higher than the S1 level of the TADF material, and the T1 level of the host material is preferably higher than the T1 level of the TADF material.

[0098] As a host material for the light-emitting layer, various carrier-transporting materials such as a material having an electron-transporting property and / or a material having a hole-transporting property, or the above-mentioned TADF material can be used. In particular, an organic compound deuterated using one embodiment of the present invention is preferable.

[0099] Preferred materials having hole transport properties include organic compounds having an amine skeleton or a π-electron-rich heteroaromatic ring skeleton. The π-electron-rich heteroaromatic ring is preferably a fused aromatic ring containing at least one of an acridine skeleton, a phenoxazine skeleton, a phenothiazine skeleton, a furan skeleton, a thiophene skeleton, and a pyrrole skeleton, and more specifically, a carbazole ring, a dibenzothiophene ring, or a ring in which an aromatic ring or a heteroaromatic ring is fused to one of these rings.

[0100] Such organic compounds having hole-transporting properties preferably have a carbazole skeleton, a dibenzofuran skeleton, a dibenzothiophene skeleton, or an anthracene skeleton. In particular, aromatic amines having a substituent containing a dibenzofuran ring or a dibenzothiophene ring, aromatic monoamines having a naphthalene ring, or aromatic monoamines in which a 9-fluorenyl group is bonded to the nitrogen of the amine via an arylene group may be used. It is preferable that these organic compounds having hole-transporting properties are substances having an N,N-bis(4-biphenyl)amino group, since this allows the fabrication of light-emitting devices with long lifetimes.

[0101] Examples of such organic compounds include 4,4'-bis[N-(1-naphthyl)-N-phenylamino]biphenyl (abbreviation: NPB), N,N'-diphenyl-N,N'-bis(3-methylphenyl)-4,4'-diaminobiphenyl (abbreviation: TPD), N,N'-bis(9,9'-spirobi[9H-fluoren]-2-yl)-N,N'-diphenyl-4,4'-diaminobiphenyl (abbreviation: BSPB), 4-phenyl-4'-(9-phenylfluoren-9-yl)triphenylamine (abbreviation: BPAFLP), 4-phenyl-3'-(9-phenylfluoren-9-yl)triphenylamine (abbreviated as mBPAFLP), 4-phenyl-4'-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviated as PCBA1BP), 4,4'-diphenyl-4''-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviated as PCBBi1BP), 4-(1-naphthyl)-4'-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviated as PC Aromatic amines such as 4,4'-di(1-naphthyl)-4''-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviated as PCBNBB), 9,9-dimethyl-N-phenyl-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]fluoren-2-amine (abbreviated as PCBAF), and N-phenyl-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-9,9'-spirobi[9H-fluorene]-2-amine (abbreviated as PCBASF) Compounds with a carbazole skeleton, such as 1,3-bis(N-carbazolyl)benzene (abbreviation: mCP), 4,4'-di(N-carbazolyl)biphenyl (abbreviation: CBP), 3,6-bis(3,5-diphenylphenyl)-9-phenylcarbazole (abbreviation: CzTP), and 9,9'-diphenyl-9H,9'H-3,3'-bicarbazole (abbreviation: PCCP), 4,4',4''-(benzene-1,3,5-triyl)tri(dibenzothiophene) (abbreviation: DBT3P-II), 2,Examples of suitable materials include compounds having a thiophene skeleton, such as 8-diphenyl-4-[4-(9-phenyl-9H-fluoren-9-yl)phenyl]dibenzothiophene (abbreviation: DBTFLP-III) and 4-[4-(9-phenyl-9H-fluoren-9-yl)phenyl]-6-phenyldibenzothiophene (abbreviation: DBTFLP-IV), and compounds having a furan skeleton, such as 4,4',4''-(benzene-1,3,5-triyl)tri(dibenzofuran) (abbreviation: DBF3P-II) and 4-{3-[3-(9-phenyl-9H-fluoren-9-yl)phenyl]phenyl}dibenzofuran (abbreviation: mmDBFFLBi-II). Among the above, compounds having an aromatic amine skeleton or a carbazole skeleton are preferred because they have good reliability, high hole transport properties, and contribute to reducing driving voltage. The organic compounds listed as examples of materials having hole transport properties for the hole transport layer can also be used.

[0102] Preferred examples of the material having electron transport properties include metal complexes such as bis(10-hydroxybenzo[h]quinolinato)beryllium(II) (abbreviation: BeBq2), bis(2-methyl-8-quinolinolato)(4-phenylphenolato)aluminum(III) (abbreviation: BAlq), bis(8-quinolinolato)zinc(II) (abbreviation: Znq), bis[2-(2-benzoxazolyl)phenolato]zinc(II) (abbreviation: ZnPBO), and bis[2-(2-benzothiazolyl)phenolato]zinc(II) (abbreviation: ZnBTZ), and organic compounds having a π-electron-deficient heteroaromatic ring. Examples of organic compounds having a π-electron-deficient heteroaromatic ring skeleton include organic compounds containing a heteroaromatic ring having an azole skeleton, organic compounds containing a heteroaromatic ring having a pyridine skeleton, organic compounds containing a heteroaromatic ring having a diazine skeleton, and organic compounds containing a heteroaromatic ring having a triazine skeleton.

[0103] Among these, organic compounds containing a heteroaromatic ring having a diazine skeleton (pyrimidine skeleton, pyrazine skeleton, pyridazine skeleton), organic compounds containing a heteroaromatic ring having a pyridine skeleton, or organic compounds containing a heteroaromatic ring having a triazine skeleton are preferred because of their high reliability. In particular, organic compounds containing a heteroaromatic ring having a diazine (pyrimidine or pyrazine) skeleton and organic compounds containing a heteroaromatic ring having a triazine skeleton have high electron transport properties and contribute to reduced driving voltage. In addition, benzofuropyrimidine skeletons, benzothienopyrimidine skeletons, benzofuropyrazine skeletons, and benzothienopyrazine skeletons are preferred because of their high acceptor properties and high reliability.

[0104] Examples of organic compounds having a π-electron-deficient heteroaromatic ring skeleton include 2-(4-biphenylyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole (abbreviation: PBD), 3-(4-biphenylyl)-4-phenyl-5-(4-tert-butylphenyl)-1,2,4-triazole (abbreviation: TAZ), 1,3-bis[5-(p-tert-butylphenyl)-1,3,4-oxadiazol-2-yl]benzene (abbreviation: OXD-7), 9-[4-(5-phenyl-1,3,4-oxadiazol-2-yl]benzene] (abbreviation: OXD-8), 1,3-bis[5-(p-tert-butylphenyl)-1,3,4-oxadiazol-2-yl]benzene] (abbreviation: OXD-9), 1,3-bis[5-(p-tert-butylphenyl)-1,3,4-oxadiazol-2-yl]benzene] (abbreviation: OXD-1 ... )phenyl]-9H-carbazole (abbreviation: CO11), 2,2',2''-(1,3,5-benzenetriyl)tris(1-phenyl-1H-benzimidazole) (abbreviation: TPBI), 2-[3-(dibenzothiophen-4-yl)phenyl]-1-phenyl-1H-benzimidazole (abbreviation: mDBTBIm-II), 4,4'-bis(5-methylbenzoxazol-2-yl)stilbene (abbreviation: BzOs), and other organic compounds with an azole skeleton, such as 3,5-bis[3-(9H-carbazol-9-yl)phenyl]piperidin Lysine (abbreviation: 35DCzPPy), 1,3,5-tri[3-(3-pyridyl)phenyl]benzene (abbreviation: TmPyPB), 4,7-diphenyl-1,10-phenanthroline (abbreviation: BPhen), bathocuproine (abbreviation: BCP), 2,9-di(naphthalen-2-yl)-4,7-diphenyl-1,10-phenanthroline (abbreviation: NBPhen), 2,2'-(1,3-phenylene)bis(9-phenyl-1,10-phenanthroline) (abbreviation: mPPhen2P), 2-[3-(2-triphenylenyl)phenyl]-1 Organic compounds containing heteroaromatic rings with a pyridine skeleton, such as 2-[3-(dibenzothiophen-4-yl)phenyl]dibenzo[f,h]quinoxaline (abbreviation: 2mDBTPDBq-II), 2-[3'-(dibenzothiophen-4-yl)biphenyl-3-yl]dibenzo[f,h]quinoxaline (abbreviation: 2mDBTBPDBq-II), 2-[3'-(9H-carbazol-9-yl)biphenyl-3-yl]dibenzo[f,h]quinoxaline (abbreviation: 2mCzBPDBq), 2-{3-[3-(N-phenyl-9H-carbazol-3-yl)-9H-carbazol-9-yl]phenyl}dibenzo[f,h]quinoxaline (abbreviation: 2mPCCzPDBq), 2-[4'-(9-phenyl)biphenyl-3-yl]dibenzo[f,h]quinoxaline (abbreviation: 2mDBTBPDBq-II), 2-[3'-(9H-carbazol-9-yl)biphenyl-3-yl]dibenzo[f,h]quinoxaline (abbreviation: 2mCzBPDBq), 2-{3-[3-(N-phenyl-9H-carbazol-3-yl)-9H-carbazol-9-yl]phenyl}dibenzo[f,h]quinoxaline (abbreviation: 2mPCCzPDBq), [(3,6-diphenyl-9H-carbazol-3-yl)-3,1'-biphenyl-1-yl]dibenzo[f,h]quinoxaline (abbreviation: 2mpPCBPDBq), 2-[4-(3,6-diphenyl-9H-carbazol-9-yl)phenyl]dibenzo[f,h]quinoxaline (abbreviation: 2CzPDBq-III), 7-[3-(dibenzothiophen-4-yl)phenyl]dibenzo[f,h]quinoxaline (abbreviation: 7mDBTPDBq-II), 6-[3-(dibenzothiophen-4-yl)phenyl]dibenzo[f,h]quinoxaline (abbreviation: 6mDBTPDBq-II) ), 9-[3'-(dibenzothiophen-4-yl)biphenyl-3-yl]naphtho[1',2':4,5]furo[2,3-b]pyrazine (abbreviation: 9mDBtBPNfpr), 9-[3'-(dibenzothiophen-4-yl)biphenyl-4-yl]naphtho[1',2':4,5]furo[2,3-b]pyrazine (abbreviation: 9pmDBtBPNfpr), 4,6-bis[3-(phenanthren-9-yl)phenyl]pyrimidine (abbreviation: 4,6mPnP2Pm), 4,6-bis[3-(dibenzothiophen-4-yl)phenyl]pyrimidine (abbreviation: 4,6mD BTP2Pm-II), 4,6-bis[3-(9H-carbazol-9-yl)phenyl]pyrimidine (abbreviated as 4,6mCzP2Pm), 9,9'-[pyrimidine-4,6-diylbis(biphenyl-3,3'-diyl)]bis(9H-carbazole) (abbreviated as 4,6mCzBP2Pm), 8-(biphenyl-4-yl)-4-[3-(dibenzothiophen-4-yl)phenyl]-[1]benzofuro[3,2-d]pyrimidine (abbreviated as 8BP-4mDBtPBfpm), 3,8-bis[3-(dibenzothiophen-4-yl)phenyl]benzofuro[2,3-b]pyrazine (abbreviation: 3,8mDBtP2Bfpr), 4,8-bis[3-(dibenzothiophen-4-yl)phenyl]-[1]benzofuro[3,2-d]pyrimidine (abbreviation: 4,8mDBtP2Bfpm), 8-[3'-(dibenzothiophen-4-yl)(biphenyl-3-yl)]naphtho[1',2':4,5]furo[3,2-d]pyrimidine (abbreviation: 8mDBtBPNfpm), 8-[(2,2'-binaphthalen)-6-yl]-4-[3-(dibenzothiophen-4-yl)phenyl]-[1]benzfuro[3,2-d]pyrimidine Benzofuro[3,2-d]pyrimidine (abbreviation: 8(βN2)-4mDBtPBfpm), 2,2'-(pyridine-2,6-diyl)bis(4-phenylbenzo[h]quinazoline) (abbreviation: 2,6(P-Bqn)2Py), 2,2'-(pyridine-2,6-diyl)bis{4-[4-(2-naphthyl)phenyl]-6-phenylpyrimidine} (abbreviation: 2,6(NP-PPm)2Py), 6-(biphenyl-3-yl)-4-[3,5-bis(9H-carbazol-9-yl)phenyl]-2-phenylpyrimidine (abbreviation: 6mBP-4Cz2PPm), 2,6-bis(4-naphthalen-1-ylphenyl)-4-[4-(3-pyridyl)phenyl]pyrimidine (abbreviated as 2,4NP-6PyPPm), 4-[3,5-bis(9H-carbazol-9-yl)phenyl]-2-phenyl-6-(biphenyl-4-yl)pyrimidine (abbreviated as 6BP-4Cz2PPm), 7-[4-(9-phenyl-9H-carbazol-2-yl)quinazolin-2-yl]-7H-dibenzo[c,g]carbazole (abbreviated as PC-cgDBCzQz), etc. Organic compounds with a diazine skeleton, such as 2-(biphenyl-4-yl)-4-phenyl-6-(9,9'-spirobi[9H-fluoren]-2-yl)-1,3,5-triazine (abbreviation: BP-SFTzn), 2-{3-[3-(benzo[b]naphtho[1,2-d]furan-8-yl)phenyl]phenyl}-4,6-diphenyl-1,3,5-triazine (abbreviation: mBnfBPTzn), and 2-{3-[3-(benzo[b]naphtho[1,2-d]furan-6-yl)phenyl]phenyl}-4,6-diphenyl-1,3,5-triazine (abbreviation: mBnfBPTzn-02), 2-{4-[3-(N-phenyl-9H-carbazol-3-yl)-9H-carbazol-9-yl]phenyl}-4,6-diphenyl-1,3,5-triazine (abbreviation: PCCzPTzn), 9-[3-(4,6-diphenyl-1,3,5-triazin-2-yl)phenyl]-9'-phenyl-2,3'-bi-9H-carbazole (abbreviation: mPCCzPTzn-02), 2-[3'-(9,9-dimethyl-9H-fluoren-2-yl)biphenyl-3-yl]-4,6-diphenyl -1,3,5-triazine (abbreviation: mFBPTzn), 5-[3-(4,6-diphenyl-1,3,5-triazin-2-yl)phenyl]-7,7-dimethyl-5H,7H-indeno[2,1-b]carbazole (abbreviation: mINc(II)PTzn), 2-{3-[3-(dibenzothiophen-4-yl)phenyl]phenyl}-4,6-diphenyl-1,3,5-triazine (abbreviation: mDBtBPTzn), 2,4,6-tris[3'-(pyridin-3-yl)biphenyl-3-yl]-1,3,5-triazine (abbreviation: TmPPPyTz) , 2-[3-(2,6-dimethyl-3-pyridinyl)-5-(9-phenanthrenyl)phenyl]-4,6-diphenyl-1,3,5-triazine (abbreviation: mPn-mDMePyPTzn), 11-[4-(biphenyl-4-yl)-6-phenyl-1,3,5-triazin-2-yl]-11,12-dihydro-12-phenylindolo[2,3-a]carbazole (abbreviation: BP-Icz(II)Tzn), 2-[3'-(triphenylen-2-yl)biphenyl-3-yl]-4,6-diphenyl-1,3,5-triazine (abbreviation: mTpB PTzn), 3-[9-(4,6-diphenyl-1,3,5-triazin-2-yl)-2-dibenzofuranyl]-9-phenyl-9H-carbazole (abbreviated as PCDBfTzn), 2-(biphenyl-3-yl)-4-phenyl-6-{8-[(1,1':4',1''-terphenyl)-4-yl]-1-dibenzofuranyl}-1,3,5-triazine (abbreviated as mBP-TPDBfTzn), 2-[4-(2-naphthalenyl)phenyl]-4-phenyl-6-spiro[9H-fluorene-9,9'-[9H]xanthene]-4-yl-1,3,Examples of suitable organic compounds include those containing a heteroaromatic ring with a triazine skeleton, such as 5-triazine (abbreviated as βNP-SFx(4)Tzn) and 2-phenyl-4,6-bis[3-(triphenylsilyl)phenyl]-1,3,5-triazine (abbreviated as mSiTrz). Organic compounds containing a heteroaromatic ring with a diazine skeleton, organic compounds containing a heteroaromatic ring with a pyridine skeleton, and organic compounds containing a heteroaromatic ring with a triazine skeleton are preferred due to their high reliability. In particular, organic compounds containing a heteroaromatic ring with a diazine (pyrimidine or pyrazine) skeleton and organic compounds containing a heteroaromatic ring with a triazine skeleton have high electron transport properties and contribute to reduced driving voltage.

[0105] The TADF materials that can be used as host materials are the same as those listed above. When a TADF material is used as a host material, the triplet excitation energy generated in the TADF material is converted to singlet excitation energy through reverse intersystem crossing, and the energy is then transferred to the light-emitting material, thereby improving the luminous efficiency of the light-emitting device. In this case, the TADF material functions as an energy donor, and the light-emitting material functions as an energy acceptor.

[0106] This is very effective when the luminescent material is a fluorescent luminescent material. In this case, in order to obtain high luminous efficiency, the S1 level of the TADF material is preferably higher than the S1 level of the fluorescent luminescent material. In addition, the T1 level of the TADF material is preferably higher than the S1 level of the fluorescent luminescent material. Therefore, the T1 level of the TADF material is preferably higher than the T1 level of the fluorescent luminescent material.

[0107] It is also preferable to use a TADF material that emits light that overlaps with the wavelength of the lowest-energy absorption band of the fluorescent material, as this allows for smooth transfer of excitation energy from the TADF material to the fluorescent material, resulting in efficient light emission.

[0108] Furthermore, to efficiently generate singlet excitation energy from triplet excitation energy through reverse intersystem crossing, carrier recombination is preferred in the TADF material. Furthermore, it is preferable that the triplet excitation energy generated in the TADF material does not transfer to triplet excitation energy in the fluorescent material. To achieve this, the fluorescent material preferably has a protecting group around the luminophore (the skeleton responsible for light emission) of the fluorescent material. The protecting group is preferably a substituent without a π bond, and is preferably a saturated hydrocarbon. Specific examples include alkyl groups with 3 to 10 carbon atoms, substituted or unsubstituted cycloalkyl groups with 3 to 10 carbon atoms, and trialkylsilyl groups with 3 to 10 carbon atoms. Multiple protecting groups are even more preferred. Substituents without a π bond have poor carrier transport properties, allowing for increased distance between the TADF material and the luminophore of the fluorescent material without significantly affecting carrier transport or carrier recombination. Here, the term "luminophore" refers to the atomic group (skeleton) responsible for light emission in the fluorescent material. The luminophore preferably has a skeleton having a π bond, preferably contains an aromatic ring, and preferably has a fused aromatic ring or a fused heteroaromatic ring. Examples of such luminophores include a phenanthrene skeleton, a stilbene skeleton, an acridone skeleton, a phenoxazine skeleton, a phenothiazine skeleton, a naphthalene skeleton, an anthracene skeleton, a fluorene skeleton, a chrysene skeleton, a triphenylene skeleton, a tetracene skeleton, a pyrene skeleton, a perylene skeleton, a coumarin skeleton, a quinacridone skeleton, and a naphthobisbenzofuran skeleton. In particular, fluorescent materials having a naphthalene skeleton, an anthracene skeleton, a fluorene skeleton, a chrysene skeleton, a triphenylene skeleton, a tetracene skeleton, a pyrene skeleton, a perylene skeleton, a coumarin skeleton, a quinacridone skeleton, or a naphthobisbenzofuran skeleton are preferred because of their high fluorescence quantum yield.

[0109] When a fluorescent emitting substance is used as the emitting substance, a material having an anthracene skeleton is suitable as the host material. Using a substance having an anthracene skeleton as a host material for a fluorescent emitting substance makes it possible to realize an emitting layer with both excellent luminous efficiency and durability. As a substance having an anthracene skeleton to be used as a host material, a diphenylanthracene skeleton, particularly a 9,10-diphenylanthracene skeleton, is preferred due to its chemical stability. Furthermore, host materials having a carbazole skeleton are preferred because of their enhanced hole injection and transport properties. However, host materials containing a benzocarbazole skeleton, in which a benzene ring is further condensed to the carbazole skeleton, are even more preferred because their HOMO level is approximately 0.1 eV higher than that of host materials having a carbazole skeleton, making it easier for holes to enter. In particular, host materials containing a dibenzocarbazole skeleton are preferred because their HOMO level is approximately 0.1 eV higher than that of host materials having a carbazole skeleton, making it easier for holes to enter, as well as providing excellent hole transport properties and high heat resistance. Therefore, a more preferable host material is a substance having both a 9,10-diphenylanthracene skeleton and a carbazole skeleton (or a benzocarbazole skeleton or a dibenzocarbazole skeleton). Note that, from the viewpoint of the hole injection / transport property, a benzofluorene skeleton or a dibenzofluorene skeleton may be used instead of the carbazole skeleton.Examples of such substances include 9-phenyl-3-[4-(10-phenyl-9-anthryl)phenyl]-9H-carbazole (abbreviation: PCzPA), 3-[4-(1-naphthyl)phenyl]-9-phenyl-9H-carbazole (abbreviation: PCPN), 9-[4-(10-phenyl-9-anthracenyl)phenyl]-9H-carbazole (abbreviation: CzPA), 7-[4-(10-phenyl-9-anthryl)phenyl]-7H-dibenzo[c,g]carbazole (abbreviation: cgDBCzPA), 6-[3-(9,10-diphenyl-2-anthryl)phenyl]benzo[b]naphtho[1,2-d]furan (abbreviation: 2mBnfPPA), 9-phenyl-10-[4'-(9-phenyl-9H-fluoren-9-yl)biphenyl-4-yl] 9-(1-naphthyl)-10-[4-(2-naphthyl)phenyl]anthracene (abbreviation: αN-βNPAnth), 9-(1-naphthyl)-10-(2-naphthyl)anthracene (abbreviation: α,β-ADN), 2-(10-phenylanthracen-9-yl)dibenzofuran, 2-(10-phenyl-9-anthracenyl)benzo Examples include zo[b]naphtho[2,3-d]furan (abbreviation: Bnf(II)PhA), 9-(2-naphthyl)-10-[3-(2-naphthyl)phenyl]anthracene (abbreviation: βN-mβNPAnth), 1-{4-[10-(biphenyl-4-yl)-9-anthracenyl]phenyl}-2-ethyl-1H-benzimidazole (abbreviation: EtBImPBPhA), etc. In particular, CzPA, cgDBCzPA, 2mBnfPPA, and PCzPA are preferred choices because they exhibit very good properties.

[0110] The host material may be a mixture of multiple substances, and when a mixture of host materials is used, it is preferable to mix a material having electron-transporting properties with a material having hole-transporting properties. By mixing a material having electron-transporting properties with a material having hole-transporting properties, the transport properties of the light-emitting layer 113 can be easily adjusted, and the recombination region can also be easily controlled. The weight ratio of the content of the material having hole-transporting properties to the material having electron-transporting properties may be 1:19 to 19:1 (material having hole-transporting properties:material having electron-transporting properties).

[0111] A phosphorescent material can be used as part of the mixed material. The phosphorescent material can be used as an energy donor that provides excitation energy to a fluorescent material when the fluorescent material is used as a light-emitting material.

[0112] Furthermore, these mixed materials may form an exciplex. It is preferable to select a combination that forms an exciplex that emits light that overlaps with the wavelength of the lowest-energy absorption band of the light-emitting material, because this allows for smooth energy transfer and efficient light emission. Furthermore, using this structure is also preferable because it reduces the driving voltage.

[0113] At least one of the materials forming the exciplex may be a phosphorescent material, which allows efficient conversion of triplet excitation energy into singlet excitation energy through reverse intersystem crossing.

[0114] As a combination of materials that efficiently form an exciplex, it is preferable that the HOMO level of the hole-transporting material is equal to or higher than the HOMO level of the electron-transporting material. It is also preferable that the LUMO level of the hole-transporting material is equal to or higher than the LUMO level of the electron-transporting material. The LUMO and HOMO levels of the materials can be derived from the electrochemical properties (reduction potential and oxidation potential) of the materials measured by cyclic voltammetry (CV).

[0115] The formation of exciplexes can be confirmed by, for example, comparing the emission spectra of a hole-transporting material, an electron-transporting material, and a mixed film of these materials and observing the phenomenon that the emission spectrum of the mixed film is shifted to longer wavelengths than the emission spectra of each material (or has a new peak at longer wavelengths). Alternatively, it can be confirmed by comparing the transient photoluminescence (PL) of a hole-transporting material, the transient PL of an electron-transporting material, and a mixed film of these materials and observing differences in transient response, such as the transient PL lifetime of the mixed film having a longer-lived component or a larger proportion of delayed components than the transient PL lifetimes of the individual materials. The above-mentioned transient PL can also be interpreted as transient electroluminescence (EL). In other words, the formation of exciplexes can also be confirmed by comparing the transient EL of a hole-transporting material, the transient EL of an electron-transporting material, and a mixed film of these materials and observing differences in transient response.

[0116] The electron transport layer 114 is a layer containing a material having electron transport properties. The material having electron transport properties is a material having an electron mobility of 1×10 at a square root of an electric field strength V / cm of 600. -7 cm 2 / Vs or more, preferably 1×10 -6 cm 2 A material having an electron mobility of 1 / Vs or more is preferred. Note that, other materials can be used as long as they have a higher electron transport property than holes. Note that, as the organic compound, an organic compound having a π-electron-deficient heteroaromatic ring is preferred. As the organic compound having a π-electron-deficient heteroaromatic ring, for example, one or more of an organic compound including a heteroaromatic ring having an azole skeleton, an organic compound including a heteroaromatic ring having a pyridine skeleton, an organic compound including a heteroaromatic ring having a diazine skeleton, and an organic compound including a heteroaromatic ring having a triazine skeleton are preferred.

[0117] Organic compounds having electron transport properties that can be used in the electron transport layer 114 include the organic compounds having electron transport properties in the light-emitting layer 113 and the organic compounds listed as organic compounds that can be used as the second organic compound in the electron injection layer 115 in Embodiment 1. Among these, organic compounds containing a heteroaromatic ring with a diazine skeleton, an organic compound containing a heteroaromatic ring with a pyridine skeleton, or an organic compound containing a heteroaromatic ring with a triazine skeleton are preferred because of their high reliability. In particular, organic compounds containing a heteroaromatic ring with a diazine (pyrimidine or pyrazine) skeleton and an organic compound containing a heteroaromatic ring with a triazine skeleton have high electron transport properties and contribute to reduced driving voltage. Organic compounds having a phenanthroline skeleton, such as mTpPPhen, PnNPhen, and mPPhen2P, are preferred, and organic compounds having a phenanthroline dimer structure, such as mPPhen2P, are more preferred due to their excellent stability. Furthermore, by using an organic compound such as 2mPCCzPDBq or DACT-II that has electron transport properties and a high HOMO level, a light-emitting device with a low driving voltage can be obtained, which is preferable.

[0118] The electron transport layer preferably contains an organic compound having an acid dissociation constant pKa of less than 4 and having electron transport properties.

[0119] The electron transport layer 114 may have a laminated structure. When the electron transport layer 114 has a laminated structure, a layer in contact with the light-emitting layer 113 may function as a hole-blocking layer. When the electron transport layer in contact with the light-emitting layer is made to function as a hole-blocking layer, it is preferable to use a material whose HOMO level is lower by 0.5 eV or more than the HOMO level of the material contained in the light-emitting layer.

[0120] The electron injection layer 115 is formed between the electron transport layer 114 and the second electrode 102. The structure of the electron injection layer 115 has been described in detail in Embodiment 1, and therefore, a repeated description will be omitted.

[0121] The second electrode 102 is an electrode including a cathode. The second electrode 102 may have a laminated structure, in which case the layer in contact with the organic compound layer 103 functions as the cathode. Materials that form the cathode include metals, alloys, electrically conductive compounds, and mixtures thereof, each having a low work function (specifically, 3.8 eV or less). Specific examples of such cathode materials include alkali metals such as lithium (Li) or cesium (Cs), elements belonging to Group 1 or Group 2 of the periodic table such as magnesium (Mg), calcium (Ca), and strontium (Sr), alloys (MgAg, AlLi), and compounds (lithium fluoride (LiF), cesium fluoride (CsF), calcium fluoride (CaF), etc.) containing these elements, rare earth metals such as europium (Eu) and ytterbium (Yb), and alloys containing these elements. However, by providing the electron injection layer 115 or a thin film of the above-mentioned material with a small work function between the second electrode 102 and the electron transport layer, various conductive materials, such as Al, Ag, ITO, indium oxide-tin oxide containing silicon or silicon oxide, can be used as the cathode regardless of the magnitude of the work function.

[0122] When the second electrode 102 is formed using a material that is transparent to visible light, a light-emitting device can be formed that emits light from the second electrode 102 side, and when the first electrode 101 is formed using a material that is transparent to visible light, a light-emitting device can be formed that emits light from the first electrode 101 side.

[0123] These conductive materials can be formed into films by dry methods such as vacuum deposition or sputtering, inkjet methods, spin coating, etc. Alternatively, they may be formed by wet methods using a sol-gel method, or by wet methods using a paste of a metal material.

[0124] In the case of a top-emission light-emitting device, the light extraction efficiency can be improved by forming a capping layer by evaporating an organic compound on the second electrode. The capping layer may have a single-layer structure or a multilayer structure. In the case of a multilayer structure, the light extraction efficiency can be further improved by using organic compounds with different refractive indices.

[0125] In addition, various methods, whether dry or wet, can be used to form the organic compound layer 103. For example, vacuum deposition, gravure printing, offset printing, screen printing, inkjet printing, spin coating, or the like may be used.

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

[0127] Next, an embodiment of a light-emitting device having a structure in which multiple light-emitting units are stacked (also referred to as a stacked device or a tandem device) will be described with reference to FIG. 1(B). This light-emitting device has multiple light-emitting units between an anode and a cathode. One light-emitting unit has a structure substantially similar to that of the organic compound layer 103 shown in FIG. 1(A). In other words, the light-emitting device shown in FIG. 1(B) is a light-emitting device having multiple light-emitting units, and the light-emitting device shown in FIG. 1(A) is a light-emitting device having one light-emitting unit.

[0128] 1(B), a first light-emitting unit 511 and a second light-emitting unit 512 are stacked between a first electrode 501 and a second electrode 502, and an intermediate layer 513 is provided between the first light-emitting unit 511 and the second light-emitting unit 512. The first electrode 501 and the second electrode 502 correspond to the first electrode 101 and the second electrode 102 in FIG. 1(A), respectively, and the same elements as those described in the description of FIG. 1(A) can be applied to them. The first light-emitting unit 511 and the second light-emitting unit 512 may have the same structure or different structures.

[0129] The intermediate layer 513 has a function of injecting electrons into one light-emitting unit and injecting holes into the other light-emitting unit when a voltage is applied between the first electrode 501 and the second electrode 502. That is, in FIG. 1B, when a voltage is applied so that the potential of the anode is higher than the potential of the cathode, the intermediate layer 513 only needs to inject electrons into the first light-emitting unit 511 and inject holes into the second light-emitting unit 512.

[0130] Intermediate layer 513 includes a charge generation layer. The charge generation layer also includes at least a P-type layer 117. P-type layer 117 is preferably formed using the composite material listed above as a material that can be used to form hole injection layer 111. P-type layer 117 may also be formed by laminating a film containing an acceptor material and a film containing a hole transport material, both of which are materials that form the composite material. By applying a potential to P-type layer 117, electrons are injected into electron transport layer 114 and holes are injected into the cathode, causing the light-emitting device to operate.

[0131] In addition, it is preferable that the intermediate layer 513 includes, in addition to the P-type layer 117, either one or both of an electron relay layer 118 and an N-type layer 119.

[0132] The electron relay layer 118 contains at least a substance having electron transport properties and has the function of preventing interaction between the N-type layer 119 and the P-type layer 117 and smoothly transferring electrons. The LUMO level of the substance having electron transport properties contained in the electron relay layer 118 is preferably between the LUMO level of the acceptor substance in the P-type layer 117 and the LUMO level of the substance contained in the layer in contact with the intermediate layer 513 in the electron transport layer 114. The specific energy level of the LUMO level of the substance having electron transport properties used in the electron relay layer 118 is −5.0 eV or higher, preferably −5.0 eV or higher and −3.0 eV or lower. Note that the substance having electron transport properties used in the electron relay layer 118 is preferably a phthalocyanine-based material or a metal complex having a metal-oxygen bond and an aromatic ligand.

[0133] The N-type layer 119 can be made of a material with high electron injection properties, such as alkali metals, alkaline earth metals, rare earth metals, and compounds thereof (alkali metal compounds (including oxides such as lithium oxide, halides, and carbonates such as lithium carbonate and cesium carbonate), alkaline earth metal compounds (including oxides, halides, and carbonates), or rare earth metal compounds (including oxides, halides, and carbonates)).

[0134] When the N-type layer 119 is formed containing a substance having an electron-transporting property and a donor substance, the donor substance can be an alkali metal, an alkaline earth metal, a rare earth metal, or a compound thereof (an alkali metal compound (including an oxide such as lithium oxide, a halide, or a carbonate such as lithium carbonate or cesium carbonate), an alkaline earth metal compound (including an oxide, a halide, or a carbonate), or a rare earth metal compound (including an oxide, a halide, or a carbonate)), or an organic compound such as tetrathianaphthacene (abbreviation: TTN), nickelocene, or decamethylnickelocene. Note that the substance having an electron-transporting property can be formed using the same material as the material for forming the electron-transporting layer 114 described above.

[0135] Alternatively, instead of N-type layer 119, a metal or metal compound described in the first embodiment as being used for the electron injection layer, a first organic compound having a π-electron-deficient heteroaromatic ring, and a second organic compound having two or more heteroaromatic rings bonded or fused to each other to form a total of three or more heteroatoms may be used in the same position as N-type layer 119. This configuration also allows the fabrication of a tandem light-emitting device with excellent characteristics.

[0136] When the anode side surface of the light-emitting unit is in contact with the intermediate layer 513, the charge generation layer of the intermediate layer 513 can also function as the hole injection layer of the light-emitting unit, so the light-emitting unit does not need to be provided with a hole injection layer. When the cathode side surface of the light-emitting unit is in contact with the intermediate layer 513, the intermediate layer 513 can also function as the electron injection layer of the light-emitting unit, so the light-emitting unit does not need to be provided with an electron injection layer.

[0137] 1B illustrates a light-emitting device having two light-emitting units, but the present invention can be applied to a light-emitting device having three or more stacked light-emitting units. By disposing a plurality of light-emitting units between a pair of electrodes and separating them with an intermediate layer 513, as in the light-emitting device according to this embodiment, it is possible to realize a device that can emit high-luminance light while maintaining a low current density and has a long life. Furthermore, it is possible to realize a light-emitting device that can be driven at a low voltage and consumes low power.

[0138] Furthermore, by making each light-emitting unit emit light of a different color, the light-emitting device as a whole can emit light of a desired color. For example, in a light-emitting device having two light-emitting units, it is possible to obtain a light-emitting device that emits white light as a whole by obtaining red and green emission colors from the first light-emitting unit and blue emission color from the second light-emitting unit.

[0139] Each layer and electrode, such as the organic compound layer 103, the first light-emitting unit 511, the second light-emitting unit 512, and the intermediate layer 513, can be formed by, for example, an evaporation method (including a vacuum evaporation method), a droplet discharge method (also called an inkjet method), a coating method, a gravure printing method, etc. They may also contain a low-molecular-weight material, a medium-molecular-weight material (including an oligomer and a dendrimer), or a polymer material.

[0140] FIG. 2A shows two adjacent light-emitting devices (light-emitting device 130a and light-emitting device 130b) included in a display device of one embodiment of the present invention.

[0141] The light-emitting device 130a has an organic compound layer 103a between a first electrode 101a on an insulating layer 175 and an opposing second electrode 102. The organic compound layer 103a has a configuration including a hole injection layer 111a, a hole transport layer 112a, a light-emitting layer 113a, an electron transport layer 114a, and an electron injection layer 115a, but may have a different stacked structure.

[0142] The light-emitting device 130b has an organic compound layer 103b between a first electrode 101b on an insulating layer 175 and an opposing second electrode 102. The organic compound layer 103b has a configuration including a hole injection layer 111b, a hole transport layer 112b, a light-emitting layer 113b, an electron transport layer 114b, and an electron injection layer 115b, but may have a different stacked structure.

[0143] The electron transport layer 114a and the electron injection layer 115a in the light-emitting device 130a, and the electron transport layer 114b and the electron injection layer 115b in the light-emitting device 130b, are preferably configured as described in the first embodiment.

[0144] Note that the second electrode 102 is preferably a continuous layer shared by the light-emitting devices 130a and 130b. The organic compound layer 103a and the organic compound layer 103b are independent from each other because they are processed by photolithography after the electron-injection layer 115a and the electron-injection layer 115b are formed, respectively. A light-emitting device according to one embodiment of the present invention can also have favorable characteristics when processed by photolithography after the electron-injection layer 115a and the electron-injection layer 115b are formed, respectively. Note that the electron-injection layer 115a and the electron-injection layer 115b may be a continuous layer shared by the light-emitting devices 130a and 130b, as shown in FIG. 3A.

[0145] The edge (outline) of the organic compound layer 103a is processed by photolithography, so that it is roughly aligned vertically with the substrate. The edge (outline) of the organic compound layer 103b is processed by photolithography, so that it is roughly aligned vertically with the substrate.

[0146] Furthermore, since the organic compound layers 103a and 103b are processed by photolithography, a gap d exists between the organic compound layers 103a and 103b. Furthermore, since the organic compound layers are processed by photolithography, the distance between the first electrode 101a and the first electrode 101b can be made smaller than that when mask vapor deposition is performed, and can be set to 0.5 μm or more and 5 μm or less.

[0147] FIG. 2(B) shows two adjacent tandem light-emitting devices (light-emitting device 130c, light-emitting device 130d) fabricated by photolithography.

[0148] The light-emitting device 130c includes an organic compound layer 103c between a first electrode 101c and a second electrode 102 on an insulating layer 175. The organic compound layer 103c includes a first light-emitting unit 501c and a second light-emitting unit 502c stacked with an intermediate layer 116c sandwiched therebetween. While FIG. 2B illustrates an example in which two light-emitting units are stacked, a configuration in which three or more light-emitting units are stacked may also be used. The first light-emitting unit 501c includes a hole injection layer 111c, a first hole transport layer 112c_1, a first light-emitting layer 113c_1, and a first electron transport layer 114c_1. The intermediate layer 116c includes a P-type layer 117c, an electron relay layer 118c, and an N-type layer 119c. The electron relay layer 118c is optional. The second light-emitting unit 502c includes a second hole-transporting layer 112c_2, a second light-emitting layer 113c_2, a second electron-transporting layer 114c_2, and an electron-injecting layer 115c.

[0149] The light-emitting device 130d includes an organic compound layer 103d between a first electrode 101d and a second electrode 102 on an insulating layer 175. The organic compound layer 103d includes a first light-emitting unit 501d and a second light-emitting unit 502d stacked with an intermediate layer 116d sandwiched therebetween. While FIG. 2B illustrates an example in which two light-emitting units are stacked, a configuration in which three or more light-emitting units are stacked may also be used. The first light-emitting unit 501d includes a hole injection layer 111d, a first hole transport layer 112d_1, a first light-emitting layer 113d_1, and a first electron transport layer 114d_1. The intermediate layer 116d includes a P-type layer 117d, an electron relay layer 118d, and an N-type layer 119d. The electron relay layer 118d is optional. The second light-emitting unit 502d includes a second hole-transporting layer 112d_2, a second light-emitting layer 113d_2, a second electron-transporting layer 114d_2, and an electron-injecting layer 115d.

[0150] In the light-emitting devices 130c and 130d, the electron injection layers 115c and 115d preferably have the same configuration as described in the first embodiment.

[0151] Note that the second electrode 102 is preferably a continuous layer shared by the light-emitting devices 130c and 130d. The organic compound layer 103c and the organic compound layer 103d are independent from each other because they are processed by photolithography after the electron-injection layer 115c and the electron-injection layer 115d are formed, respectively. A light-emitting device according to one embodiment of the present invention can also have excellent characteristics when processed by photolithography after the electron-injection layer 115c and the electron-injection layer 115d are formed, respectively. Note that the electron-injection layer 115c and the electron-injection layer 115d may be a continuous layer shared by the light-emitting devices 130c and 130d, as shown in FIG. 3B.

[0152] The edge (outline) of the organic compound layer 103c is processed by photolithography, so that it is roughly aligned vertically with the substrate. The edge (outline) of the organic compound layer 103d is processed by photolithography, so that it is roughly aligned vertically with the substrate.

[0153] Furthermore, since the organic compound layer 103c is processed by photolithography, a gap d exists between the organic compound layer 103c and the organic compound layer 103d. Furthermore, since the organic compound layer is processed by photolithography, the distance between the first electrode 101c and the first electrode 101d can be made smaller than that when mask vapor deposition is performed, and can be set to 0.5 μm or more and 5 μm or less.

[0154] In the light-emitting device of one embodiment of the present invention, the organic compound layer is processed by photolithography, and therefore, the light-emitting device can be processed with sufficient precision to fabricate a high-resolution display device. Furthermore, since the lithography process can be performed on the electron injection layer far from the light-emitting layer without contamination by alkali metals, the light-emitting device can have excellent characteristics. As described above, the light-emitting device of one embodiment of the present invention having such a structure can realize a high-resolution display device and can have excellent characteristics.

[0155] Note that the organic compound layer in the light-emitting device of one embodiment of the present invention is processed at one time by photolithography, and therefore the contours of all layers included in the organic compound layer are approximately the same. Here, "approximately the same" in this specification means that the deviation between contour A of layer A and contour B of layer B included in the organic compound layer is within 5% of the width of the organic compound layer on a line perpendicular to the contours of the compared portions. Furthermore, if the end face of the organic compound layer has a tapered shape, continuous changes in the contour are allowed.

[0156] The structure of this embodiment mode can be used in appropriate combination with other structures.

[0157] (Embodiment 3) In this embodiment, a display device according to one embodiment of the present invention will be described.

[0158] The display device of the present embodiment can be a high-definition display device, and can therefore be used as a display unit for information terminals (wearable devices) such as wristwatches and bracelets, as well as for wearable devices that can be worn on the head, such as VR devices such as head-mounted displays (HMDs) and AR devices such as glasses.

[0159] The display device of the present embodiment can be a high-resolution display device or a large-sized display device. Therefore, the display device of the present embodiment can be used in electronic devices with relatively large screens, such as television devices, desktop or notebook personal computers, computer monitors, digital signage, and large game machines such as pachinko machines, as well as in the display units of digital cameras, digital video cameras, digital photo frames, mobile phones, portable game machines, personal digital assistants, and sound reproduction devices.

[0160] [Display module] 4A shows a perspective view of a display module 280. The display module 280 includes a display device 100A and an FPC 290. Note that the display device included in the display module 280 is not limited to the display device 100A, and may be any of the display devices 100B to 100E2 described below.

[0161] The display module 280 has a substrate 291 and a substrate 292. The display module 280 has a display unit 281. The display unit 281 is an area that displays an image in the display module 280, and is an area where light from each pixel provided in a pixel unit 284 (described later) can be viewed.

[0162] 4(B) is a perspective view schematically showing the configuration on the substrate 291 side. A circuit portion 282, a pixel circuit portion 283 on the circuit portion 282, and a pixel portion 284 on the pixel circuit portion 283 are stacked on the substrate 291. A terminal portion 285 for connecting to an FPC 290 is provided in a portion of the substrate 291 that does not overlap with the pixel portion 284. The terminal portion 285 and the circuit portion 282 are electrically connected by a wiring portion 286 composed of a plurality of wirings.

[0163] The pixel section 284 has a plurality of periodically arranged pixels 284a. An enlarged view of one pixel 284a is shown on the right side of Fig. 4(B). The various configurations described in the previous embodiments can be applied to the pixel 284a.

[0164] The pixel circuit section 283 has a plurality of pixel circuits 283a arranged periodically.

[0165] One pixel circuit 283a is a circuit that controls the driving of a plurality of elements included in one pixel 284a.

[0166] The circuit portion 282 includes a circuit for driving each pixel circuit 283a of the pixel circuit portion 283. For example, it is preferable that the circuit portion 282 includes one or both of a gate line driver circuit and a source line driver circuit. In addition, the circuit portion 282 may include at least one of an arithmetic circuit, a memory circuit, a power supply circuit, etc.

[0167] The FPC 290 functions as wiring for supplying a video signal, a power supply potential, or the like from the outside to the circuit section 282. An IC may be mounted on the FPC 290.

[0168] The display module 280 can be configured such that one or both of the pixel circuit unit 283 and the circuit unit 282 are stacked below the pixel unit 284, thereby making it possible to extremely increase the aperture ratio (effective display area ratio) of the display unit 281.

[0169] Such a display module 280 has extremely high resolution and can therefore be suitably used in VR devices such as HMDs or glasses-type AR devices. For example, even in a configuration in which the display unit of the display module 280 is viewed through lenses, the display module 280 has an extremely high-resolution display unit 281, so that even if the display unit is enlarged with the lenses, the pixels are not visible, allowing for a highly immersive display. Furthermore, the display module 280 is not limited to this and can be suitably used in electronic devices having relatively small display units.

[0170] [Display device 100A] The display device 100A shown in FIG. 5A includes a substrate 301, a light-emitting device 130R, a light-emitting device 130G, a light-emitting device 130B, a capacitor 240, and a transistor 310. The display device 100A shown in FIG.

[0171] The substrate 301 corresponds to the substrate 291 in FIGS. 4A and 4B. The transistor 310 has a channel formation region in the substrate 301. The substrate 301 can be, for example, a semiconductor substrate such as a single crystal silicon substrate. The transistor 310 includes a part of the substrate 301, a conductive layer 311, a low-resistance region 312, an insulating layer 313, and an insulating layer 314. The conductive layer 311 functions as a gate electrode. The insulating layer 313 is located between the substrate 301 and the conductive layer 311 and functions as a gate insulating layer. The low-resistance region 312 is a region in which the substrate 301 is doped with impurities and functions as a source or drain. The insulating layer 314 is provided to cover a side surface of the conductive layer 311.

[0172] Furthermore, an element isolation layer 315 is provided between two adjacent transistors 310 so as to be embedded in the substrate 301 .

[0173] In addition, an insulating layer 261 is provided to cover the transistor 310 , and a capacitor 240 is provided on the insulating layer 261 .

[0174] Capacitor 240 has conductive layer 241, conductive layer 245, and insulating layer 243 located therebetween. Conductive layer 241 functions as one electrode of capacitor 240, conductive layer 245 functions as the other electrode of capacitor 240, and insulating layer 243 functions as a dielectric of capacitor 240.

[0175] The conductive layer 241 is provided over the insulating layer 261 and is buried in the insulating layer 254. The conductive layer 241 is electrically connected to one of the source and drain of the transistor 310 by a plug 271 buried in the insulating layer 261. The insulating layer 243 is provided to cover the conductive layer 241. The conductive layer 245 is provided in a region overlapping with the conductive layer 241 with the insulating layer 243 interposed therebetween.

[0176] An insulating layer 255 is provided covering the capacitor 240, an insulating layer 174 is provided on the insulating layer 255, and an insulating layer 175 is provided on the insulating layer 174. Light-emitting device 130R, light-emitting device 130G, and light-emitting device 130B are provided on the insulating layer 175. An insulator is provided in the region between adjacent light-emitting devices.

[0177] An insulating layer 156 (insulating layer 156R, insulating layer 156G, insulating layer 156B) is provided so as to have an area overlapping with the side surfaces of the conductive layer 151 (conductive layer 151R, conductive layer 151G, conductive layer 151B) and the conductive layer 152 (conductive layer 152R, conductive layer 152G, conductive layer 152B). A sacrificial layer 158 (sacrificial layer 158R, sacrificial layer 158B, sacrificial layer 158G) is located on the organic compound layer 103 (organic compound layer 103R, organic compound layer 103G, organic compound layer 103B). In addition, an inorganic insulating layer 125 and an insulating layer 127 on the inorganic insulating layer 125 are preferably provided between adjacent light-emitting devices 130.

[0178] The conductive layer 151R, the conductive layer 151G, and the conductive layer 151B are electrically connected to one of the source and drain of the transistor 310 via an insulating layer 243, an insulating layer 255, an insulating layer 174, a plug 256 embedded in the insulating layer 175, a conductive layer 241 embedded in the insulating layer 254, and a plug 271 embedded in the insulating layer 261. Various conductive materials can be used for the plug.

[0179] Furthermore, a protective layer 131 is provided on the light-emitting devices 130R, 130G, and 130B. A substrate 120 is bonded to the protective layer 131 with a resin layer 122. For details of the components from the light-emitting devices 130 to the substrate 120, refer to Embodiment 2. The substrate 120 corresponds to the substrate 292 in FIG. 4(A).

[0180] Fig. 5(B) is a modified example of the display device 100A shown in Fig. 5(A). The display device shown in Fig. 5(B) has a colored layer 132R, a colored layer 132G, and a colored layer 132B, and the light-emitting device 130 has an area where it overlaps with one of the colored layer 132R, the colored layer 132G, and the colored layer 132B. In the display device shown in Fig. 5(B), the light-emitting device 130 can emit, for example, white light. Furthermore, for example, the colored layer 132R can transmit red light, the colored layer 132G can transmit green light, and the colored layer 132B can transmit blue light.

[0181] [Display device 100B] FIG. 6 shows a perspective view of the display device 100B.

[0182] The display device 100B has a configuration in which a substrate 352 and a substrate 351 are bonded together. In Fig. 6, the substrate 352 is indicated by a dashed line.

[0183] The display device 100B has a pixel unit 177, a connection unit 140, a circuit 356, wiring 355, etc. FIG. 6 shows an example in which an IC 354 and an FPC 353 are mounted on the display device 100B. Therefore, the configuration shown in FIG. 6 can also be called a display module having the display device 100B, an IC (integrated circuit), and an FPC. Here, a display device with a connector such as an FPC attached to a substrate, or a display device with an IC mounted on the substrate, is called a display module.

[0184] The connection section 140 is provided outside the pixel section 177. There may be one or more connection sections 140. The connection section 140 electrically connects the common electrode of the light-emitting device and the conductive layer, and can supply a potential to the common electrode.

[0185] The circuit 356 can be, for example, a scanning line driver circuit.

[0186] The wiring 355 has a function of supplying signals and power to the pixel portion 177 and the circuit 356. The signals and power are input to the wiring 355 from the outside via the FPC 353 or from the IC 354.

[0187] 6 shows an example in which an IC 354 is provided on a substrate 351 by a COG (Chip On Glass) method or a COF (Chip on Film) method. The IC 354 may be, for example, an IC having a scanning line driver circuit or a signal line driver circuit. The display device 100B and the display module may not include an IC. Alternatively, the IC may be mounted on an FPC by a COF method, for example.

[0188] Figure 7 shows an example of a cross section of the display device 100B in Figure 6, where part of the area including the FPC 353, part of the circuit 356, part of the pixel section 177, part of the connection section 140, and part of the area including the end portion are cut away, as display device 100C.

[0189] [Display device 100C] The display device 100C shown in Figure 7 has, between substrate 351 and substrate 352, transistor 201, transistor 205, light-emitting device 130R that emits red light, light-emitting device 130G that emits green light, and light-emitting device 130B that emits blue light, etc.

[0190] For details of the light emitting devices 130R, 130G, and 130B, see the second embodiment.

[0191] Light-emitting device 130R has conductive layer 224R, conductive layer 151R on conductive layer 224R, and conductive layer 152R on conductive layer 151R. Light-emitting device 130G has conductive layer 224G, conductive layer 151G on conductive layer 224G, and conductive layer 152G on conductive layer 151G. Light-emitting device 130B has conductive layer 224B, conductive layer 151B on conductive layer 224B, and conductive layer 152B on conductive layer 151B.

[0192] The conductive layer 224R is connected to the conductive layer 222b of the transistor 205 through an opening provided in the insulating layer 214. An end of the conductive layer 151R is located outside an end of the conductive layer 224R. An insulating layer 156R is provided to have a region in contact with a side surface of the conductive layer 151R, and a conductive layer 152R is provided to cover the conductive layer 151R and the insulating layer 156R.

[0193] Conductive layer 224G, conductive layer 151G, conductive layer 152G, and insulating layer 156G in light-emitting device 130G, and conductive layer 224B, conductive layer 151B, conductive layer 152B, and insulating layer 156B in light-emitting device 130B are similar to conductive layer 224R, conductive layer 151R, conductive layer 152R, and insulating layer 156R in light-emitting device 130R, and therefore detailed description thereof will be omitted.

[0194] Recesses are formed in conductive layers 224R, 224G, and 224B so as to cover the openings provided in insulating layer 214. Layer 128 is buried in the recesses.

[0195] Layer 128 has the function of filling in recesses in conductive layer 224R, conductive layer 224G, and conductive layer 224B and flattening the surface. Conductive layers 151R, 151G, and 151B, which are electrically connected to conductive layer 224R, conductive layer 224G, and conductive layer 224B, are provided on conductive layer 224R, conductive layer 224G, and conductive layer 224B and layer 128. Therefore, the regions overlapping with the recesses in conductive layer 224R, conductive layer 224G, and conductive layer 224B can also be used as light-emitting regions, thereby increasing the aperture ratio of the pixel.

[0196] The layer 128 may be an insulating layer or a conductive layer. Various inorganic insulating materials, organic insulating materials, and conductive materials can be used for the layer 128 as appropriate. In particular, the layer 128 is preferably formed using an insulating material, and is particularly preferably formed using an organic insulating material. For example, the organic insulating materials that can be used for the insulating layer 127 described above can be used for the layer 128.

[0197] A protective layer 131 is provided on the light-emitting devices 130R, 130G, and 130B. The protective layer 131 and the substrate 352 are bonded via an adhesive layer 142. A light-shielding layer 157 is provided on the substrate 352. A solid sealing structure, a hollow sealing structure, or the like can be applied to seal the light-emitting device 130. In FIG. 7, the space between the substrates 352 and 351 is filled with the adhesive layer 142, and a solid sealing structure is applied. Alternatively, the space may be filled with an inert gas (nitrogen, argon, etc.), and a hollow sealing structure may be applied. In this case, the adhesive layer 142 may be provided so as not to overlap with the light-emitting devices. Alternatively, the space may be filled with a resin different from the frame-shaped adhesive layer 142.

[0198] 7 shows an example in which connecting portion 140 has conductive layer 224C obtained by processing the same conductive film as conductive layers 224R, 224G, and 224B, conductive layer 151C obtained by processing the same conductive film as conductive layers 151R, 151G, and 151B, and conductive layer 152C obtained by processing the same conductive film as conductive layers 152R, 152G, and 152B. Also shown in FIG. 7 is an example in which insulating layer 156C is provided so as to have a region overlapping with a side surface of conductive layer 151C.

[0199] The display device 100C is a top-emission type. Light emitted by the light-emitting device is emitted toward the substrate 352. The substrate 352 is preferably made of a material that is highly transparent to visible light. The pixel electrodes contain a material that reflects visible light, and the counter electrode (common electrode 155) contains a material that transmits visible light.

[0200] An insulating layer 211, an insulating layer 213, an insulating layer 215, and an insulating layer 214 are provided in this order over the substrate 351. A part of the insulating layer 211 functions as a gate insulating layer for each transistor. A part of the insulating layer 213 functions as a gate insulating layer for each transistor. The insulating layer 215 is provided to cover the transistor. The insulating layer 214 is provided to cover the transistor and functions as a planarization layer. Note that the number of gate insulating layers and the number of insulating layers covering the transistors are not limited, and each may be a single layer or two or more layers.

[0201] The insulating layers 211, 213, and 215 are each preferably made of an inorganic insulating film.

[0202] The insulating layer 214, which functions as a planarizing layer, is preferably an organic insulating layer.

[0203] The transistor 201 and the transistor 205 each include a conductive layer 221 functioning as a gate, an insulating layer 211 functioning as a gate insulating layer, a conductive layer 222a and a conductive layer 222b functioning as a source and a drain, a semiconductor layer 231, an insulating layer 213 functioning as a gate insulating layer, and a conductive layer 223 functioning as a gate.

[0204] A connection portion 204 is provided in a region of the substrate 351 where the substrate 352 does not overlap. In the connection portion 204, the source electrode or drain electrode of the transistor 201 is electrically connected to the FPC 353 via a conductive layer 166 and a connection layer 242. The conductive layer 166 has an example of a laminated structure including a conductive film obtained by processing the same conductive film as the conductive layers 224R, 224G, and 224B, a conductive film obtained by processing the same conductive film as the conductive layers 151R, 151G, and 151B, and a conductive film obtained by processing the same conductive film as the conductive layers 152R, 152G, and 152B. The conductive layer 166 is exposed on the top surface of the connection portion 204. This allows the connection portion 204 and the FPC 353 to be electrically connected via the connection layer 242.

[0205] It is preferable to provide a light-shielding layer 157 on the surface of substrate 352 facing substrate 351. Light-shielding layer 157 can be provided between adjacent light-emitting devices, on connecting portions 140, on circuits 356, etc. Various optical members can be arranged on the outside of substrate 352.

[0206] The materials that can be used for the substrate 120 can be used for the substrate 351 and the substrate 352, respectively.

[0207] The adhesive layer 142 can be made of a material that can be used for the resin layer 122 .

[0208] The connection layer 242 may be an anisotropic conductive film (ACF), an anisotropic conductive paste (ACP), or the like.

[0209] [Display device 100D] The display device 100D shown in FIG. 8 differs from the display device 100C shown in FIG. 7 mainly in that it is a bottom-emission display device.

[0210] Light emitted from the light emitting device is emitted toward the substrate 351. It is preferable that a material with high transparency to visible light is used for the substrate 351. On the other hand, the light transparency of the material used for the substrate 352 is not an issue.

[0211] It is preferable to form a light-shielding layer 317 between the substrate 351 and the transistor 201 and between the substrate 351 and the transistor 205. Figure 8 shows an example in which the light-shielding layer 317 is provided over the substrate 351, the insulating layer 153 is provided over the light-shielding layer 317, and the transistors 201, 205, etc. are provided over the insulating layer 153.

[0212] Light emitting device 130R includes conductive layer 112R, conductive layer 126R on conductive layer 112R, and conductive layer 129R on conductive layer 126R.

[0213] Light emitting device 130B includes conductive layer 112B, conductive layer 126B on conductive layer 112B, and conductive layer 129B on conductive layer 126B.

[0214] The conductive layers 112R, 112B, 126R, 126B, 129R, and 129B are each made of a material that is highly transparent to visible light. The second electrode 102 is preferably made of a material that reflects visible light.

[0215] Although the light emitting device 130G is not shown in FIG. 8, the light emitting device 130G is also provided.

[0216] In addition, although FIG. 8 and other figures show an example in which the top surface of the layer 128 has a flat portion, the shape of the layer 128 is not particularly limited.

[0217] [Display device 100D2] The display device 100D2 shown in FIG. 9 is an example of a bottom-emission display device that differs from the display device 100D shown in FIG. 8. The display device 100D2 differs from the display device 100D in that it has an organic resin layer 180. The display device 100D2 shown in FIG. 9(A) has a substrate 301, a light-emitting device 130R, and a light-emitting device 130W. Note that in the figure, the reference numerals of the same components as those in FIG. 8 may be omitted, and for details, please refer to the description in FIG. 8.

[0218] 9(B) shows a top view layout of pixel 178 (pixel 178a and pixel 178b) having subpixels 110 (subpixels 110R, 110G, 110B, and 110W), and FIG. 9(C) shows a top view of organic resin layer 180 in a region where subpixels 110R and 110G of pixel 178 are formed. The width between light-shielding layers 317 is width 110Rw in the light-emitting region of subpixel 110R.

[0219] As shown in FIG. 9(A), the organic resin layer 180 is provided on the insulating layer 214. As shown in the region surrounded by the dashed line in FIG. 9(A) and in FIG. 9(C), the organic resin layer 180 has curved recesses 181 (recesses 181a and 181b) at least in the region where the subpixels are formed. The recesses 181 may be provided outside the light-emitting region, such as recess 181c. By providing recess 181c, light emitted in the region overlapping with the light-shielding layer 317 or light traveling to the region overlapping with the light-shielding layer 317 is refracted and can be extracted from the light-emitting region, thereby improving the light-emitting efficiency.

[0220] A plurality of recesses 181 may be formed in a matrix. Recesses 181a and 181b may be provided in contact with each other, or may have a flat surface between them.

[0221] 9, the recess has a hexagonal top surface shape (FIG. 9(C)) and a semicircular cross-sectional shape (FIG. 9(A)), but other shapes may be used as needed. For example, the recess may have a polygonal top surface shape such as a triangle, a quadrangle (including a rectangle and a square), a pentagon, or any of these polygons with rounded corners, an ellipse, or a circle.

[0222] An insulating layer containing an organic material can be used as the organic resin layer 180. For example, acrylic resin, polyimide resin, epoxy resin, imide resin, polyamide resin, polyimideamide resin, silicone resin, siloxane resin, benzocyclobutene resin, phenol resin, precursors of these resins, etc. can be used as the organic resin layer 180. Alternatively, organic materials such as polyvinyl alcohol (PVA), polyvinyl butyral, polyvinylpyrrolidone, polyethylene glycol, polyglycerin, pullulan, water-soluble cellulose, or alcohol-soluble polyamide resin can be used as the organic resin layer 180.

[0223] Furthermore, a photosensitive resin can be used as the organic resin layer 180. A photoresist can be used as the photosensitive resin. The photosensitive resin can be a positive type material or a negative type material.

[0224] The organic resin layer 180 may contain a material that absorbs visible light. For example, the organic resin layer 180 itself may be made of a material that absorbs visible light, or the organic resin layer 180 may contain a pigment that absorbs visible light. For example, the organic resin layer 180 may be made of a resin that can be used as a color filter that transmits red, blue, or green light and absorbs other light, or a resin that contains carbon black as a pigment and functions as a black matrix.

[0225] In addition, a first electrode 101 (a first electrode 101R and a first electrode 101W) is provided on the organic resin layer 180, and an organic compound layer 103 is provided on the first electrode 101. Ends of the first electrode 101 and the organic compound layer 103 may be covered with an insulating layer 127.

[0226] Furthermore, the first electrode 101 formed on the organic resin layer 180 has a recess similar to the recess of the organic resin layer 180. Furthermore, the organic compound layer 103 formed on the first electrode 101 has a recess similar to the recess of the first electrode 101. Furthermore, the common layer 104 formed on the organic compound layer 103 has a recess similar to the recess of the organic compound layer 103. Furthermore, the second electrode 102 formed on the common layer 104 has a recess similar to the recess of the common layer 104. That is, the recesses of the organic resin layer 180, the first electrode 101, the organic compound layer 103, the common layer 104, and the second electrode 102 have a structure in which they overlap one another.

[0227] In addition, a common layer 104 is provided over the organic compound layer 103 and the insulating layer 127, and a second electrode 102 is provided over the common layer 104. A protective layer 131 is provided over the second electrode 102, and the second electrode 102 is bonded to a substrate 352 via an adhesive layer 142.

[0228] Although light emitting device 130G and light emitting device 130B are not shown in FIG. 9, light emitting device 130G and light emitting device 130B are also provided.

[0229] The light-emitting device of one embodiment of the present invention having the organic resin layer 180 as described above contains an organic compound having deuterium in the organic compound layer 103 as described in Embodiment 1. Therefore, due to the effect of the organic resin layer 180 and the effect of the organic semiconductor device using the organic compound of the present invention being inseparably integrated, an organic semiconductor device with high light-emitting efficiency can be provided. Therefore, an organic semiconductor device with good reliability, low driving voltage, and low power consumption can be provided.

[0230] [Display device 100E] The display device 100E shown in FIG. 10 is a modification of the display device 100C shown in FIG. 7, and differs from the display device 100C mainly in that it has colored layers 132R, 132G, and 132B.

[0231] In the display device 100E, the light-emitting device 130 has an area that overlaps one of the colored layer 132R, the colored layer 132G, and the colored layer 132B. The colored layer 132R, the colored layer 132G, and the colored layer 132B can be provided on the surface of the substrate 352 facing the substrate 351. An end of the colored layer 132R, an end of the colored layer 132G, and an end of the colored layer 132B can overlap the light-shielding layer 157.

[0232] In the display device 100E, the light-emitting device 130 can emit, for example, white light. Furthermore, for example, the colored layer 132R can transmit red light, the colored layer 132G can transmit green light, and the colored layer 132B can transmit blue light. The display device 100E may be configured such that the colored layers 132R, 132G, and 132B are provided between the protective layer 131 and the adhesive layer 142.

[0233] [Display device 100E2] The display device 100E2 shown in Fig. 11 is a modified example of the display device 100E shown in Fig. 10, and has microlenses 182 on the colored layers 132R, 132G, and 132B. Note that in the figure, the reference numerals of the same components as those in Fig. 10 may be omitted, and for details, please refer to the description in Fig. 10.

[0234] 11(B) shows a top view layout of a pixel 178 (pixel 178a and pixel 178b) having subpixels 110 (subpixels 110R, 110G, and 110B), and FIG. 11(C) shows a top view of a microlens 182 in a region where the subpixels 110R and 110G of the pixel 178 are formed. The width of the region where the common electrode 155 and the organic compound layer 103 are in contact is width 110Gw in the light-emitting region of the subpixel 110G.

[0235] 9(A) has a planarization film 143 provided on a protective layer 131, and colored layers 132R, 132G, and 132B provided on the planarization film 143. A planarization film 144 is provided so as to cover the colored layers 132R, 132G, and 132B. A microlens 182 is provided on the planarization film 144.

[0236] As shown in FIG. 11C, the microlens 182 may be provided for each sub-pixel in a region where the sub-pixel is formed.

[0237] 11(C), the top surface shape of the microlens 182 is shown as a hexagon, but other shapes may be used as needed. For example, the top surface shape of the recess may be a polygon such as a triangle, a quadrangle (including a rectangle and a square), a pentagon, or any of these polygons with rounded corners, an ellipse, or a circle.

[0238] The microlenses 182 can be formed using the same material as the organic resin layer 180 .

[0239] The light-emitting device of one embodiment of the present invention having the above-described microlens 182 contains an organic compound having deuterium in the organic compound layer 103 as described in Embodiment 1. Therefore, an organic semiconductor device with high emission efficiency can be provided due to the effect of the microlens 182 and the effect of the organic semiconductor device using the organic compound of the present invention being inseparably integrated. Therefore, an organic semiconductor device with high reliability, low driving voltage, and low power consumption that is optimal for a display for mobile applications can be provided.

[0240] This embodiment mode can be combined with other embodiment modes or examples as appropriate. In addition, in this specification, when multiple configuration examples are shown in one embodiment mode, the configuration examples can be combined as appropriate. [Example]

[0241] <Synthesis Example 1> This example describes a synthesis method for 8-chloro-4-hydroxy[1]benzofuro[3,2-d]pyrimidine-2-d1, an organic compound according to one embodiment of the present invention and represented by structural formula (100) in Embodiment 1. Note that the organic compound represented by structural formula (100) and 8-chloro[1]benzofuro[3,2-d]pyrimidin-4(1H)one-2-d1 represented by structural formula (100-1) exist as an equilibrium mixture represented by structural formula (100-2).

[0242] [ka]

[0243] [ka]

[0244] Step 1: Synthesis of 8-chloro-4-hydroxy[1]benzofuro[3,2-d]pyrimidine-2-d1 An autoclave was charged with 9.3 g (39 mmol) of 4,8-dichloro[1]benzofuro[3,2-d]pyrimidine, 31 mL of 2-propanol, 310 mL of heavy water, and 7.59 g (3.9 mmol) of 10% Pt / C. A lid was placed on the autoclave, and the atmosphere inside the autoclave was purged with Ar. The mixture was placed on a stand, and a cylindrical heater was attached to the outside of the autoclave. The temperature of the heater (external temperature) was raised to 120 °C. After the heater reached 120 °C, the mixture was heated for 43 hours. After 43 hours, the mixture was allowed to cool to room temperature and allowed to stand overnight. After standing, the supernatant liquid of the mixture was removed by decantation. DMF was added to the remaining solid. The mixture was stirred for approximately 1 hour to partially dissolve the solid. The dissolved mixture was filtered through Celite to obtain a filtrate. After filtration, additional DMF was added to the Celite, and the target product was dissolved from the solid filtered onto the Celite, obtaining a wash solution. The filtrate and wash solution were mixed to obtain approximately 500 mL of solution. Approximately 3 L of water was added to this solution to obtain a suspension. This suspension was filtered to obtain a reddish-orange solid. The obtained solid was dried under reduced pressure at approximately 80 °C. After drying, 4.0 g of the target product was obtained in a 46% yield. The synthetic scheme for 8-chloro-4-hydroxy[1]benzofuro[3,2-d]pyrimidine-2-d1 (or 8-chloro[1]benzofuro[3,2-d]pyrimidin-4(1H)one-2-d1) obtained in Step 1 is shown in formula (a-1) below.

[0245] [ka]

[0246] The reddish-orange solid obtained in step 1 was analyzed by nuclear magnetic resonance spectroscopy ( 1 H-NMR, 13 The results of the analysis by C-NMR are shown below. 1 The H-NMR chart is shown in Figure 12. 13 The C-NMR chart is shown in Figure 13. This indicates that 8-chloro-4-hydroxy[1]benzofuro[3,2-d]pyrimidine-2-d1 (or 8-chloro[1]benzofuro[3,2-d]pyrimidin-4(1H)one-2-d1) was successfully synthesized.

[0247] 1 H-NMR.δ(DIMSO-d6):8.31(s,0.37H 63% deuterated),8.13(d,1H,J=7.5Hz),7.93-7.95(m,1H),7.74-7.77(m,1H).

[0248] 13 C-NMR.δ(DIMSO-d6):155.3,153.5,147.9,143.5,141.3,130.8,130.7,129.8,124.8,121.6,115.8.

[0249] Next, 8-chloro-4-hydroxy[1]benzofuro[3,2-d]pyrimidine-2-d1 (or 8-chloro[1]benzofuro[3,2-d]pyrimidin-4(1H)one-2-d1) obtained in this example was analyzed by liquid chromatography mass spectrometry (LC / MS analysis).

[0250] In addition, LC / MS analysis was performed by LC (liquid chromatography) separation using Waters ACQUITY UPLC H-Class Plus, and MS analysis (mass spectrometry) using Waters SELECT SERIES Cyclic IMS.

[0251] For LC separation, an arbitrary column was used, the column temperature was set to 40°C, and the solvent was appropriately selected as the flow condition. The sample was prepared by dissolving 8-chloro-4-hydroxy[1]benzofuro[3,2-d]pyrimidine-2-d1 (or 8-chloro[1]benzofuro[3,2-d]pyrimidin-4(1H)one-2-d1) at an arbitrary concentration in an organic solvent, and the injection volume was 5.0 μL.

[0252] In addition, by PRM, the MS of m / z 221.01, which is the exact mass of 8-chloro-4-hydroxy[1]benzofuro[3,2-d]pyrimidine-2-d1 (or 8-chloro[1]benzofuro[3,2-d]pyrimidin-4(1H)one-2-d1), 2Measurements were performed. The PRM settings were for the target ion mass range of m / z 221.01 ± 2.0 (isolation window = 4), and detection was performed in positive mode. The energy NCE (Normalized Collision Energy) used to accelerate the target ions in the collision cell was set to 40. The obtained MS spectrum is shown in Figure 14.

[0253] The above NMR spectrum and MS 2 The measurement results showed that 8-chloro-4-hydroxy[1]benzofuro[3,2-d]pyrimidine-2-d1 (or 8-chloro[1]benzofuro[3,2-d]pyrimidin-4(1H)one-2-d1) was synthesized. [Explanation of symbols]

[0254] 100A: display device, 100B: display device, 100C: display device, 100D: display device, 100E: display device, 101: first electrode, 101a: first electrode, 101b: first electrode, 101c: first electrode, 101d: first electrode, 101W: first electrode, 102: second electrode, 103: organic compound layer, 103a: organic compound layer, 103B: organic compound layer, 103b: organic compound layer, 103c: organic compound layer, 103d: organic compound layer, 103G: organic compound layer, 103R: organic compound layer, 104: common layer, 109: insulator, 110: subpixel, 110B: sub Pixel, 110G: subpixel, 110Gw: width, 110R: subpixel, 110Rw: width, 110W: subpixel, 111: hole injection layer, 111a: hole injection layer, 111b: hole injection layer, 111c: hole injection layer, 111d: hole injection layer, 112: hole transport layer, 112a: hole transport layer, 112B: conductive layer, 112b: hole transport layer, 112c_1: first hole transport layer, 112c_2: second hole transport layer, 112d_1: first hole transport layer, 112d_2: second hole transport layer, 112R: conductive layer, 113: light emitting layer, 113a: light emitting layer, 113b: light emitting layer, 113c_1: first Light-emitting layer, 113c_2: second light-emitting layer, 113d_1: first light-emitting layer, 113d_2: second light-emitting layer, 114: electron transport layer, 114a: electron transport layer, 114b: electron transport layer, 114c_1: first electron transport layer, 114c_2: second electron transport layer, 114d_1: first electron transport layer, 114d_2: second electron transport layer, 115: electron injection layer, 115a: electron injection layer, 115b: electron injection layer, 115c: electron injection layer, 115d: electron injection layer, 116c: intermediate layer, 116d: intermediate layer, 117: P-type layer, 117c: P-type layer, 117d: P-type layer, 118: electron relay layer , 118c: electronic relay layer, 118d: electronic relay layer, 119: N-type layer, 119c: N-type layer, 119d: N-type layer, 120: substrate, 122: resin layer, 125: inorganic insulating layer, 126B: conductive layer, 126R: conductive layer, 127: insulating layer, 128: layer, 129B: conductive layer, 129R: conductive layer, 130: light-emitting device, 130a: light-emitting device, 130B: light-emitting device, 130b: light-emitting device, 130c: light-emitting device, 130d: light-emitting device, 130G: light-emitting device, 130R: light-emitting device, 130W: light-emitting device, 131: protective layer, 132B: colored layer,132G: colored layer, 132R: colored layer, 140: connecting portion, 142: adhesive layer, 143: planarizing film, 144: planarizing film, 151: conductive layer, 151B: conductive layer, 151C: conductive layer, 151G: conductive layer, 151R: conductive layer, 152: conductive layer, 152B: conductive layer, 152C: conductive layer, 152G: conductive layer, 152R: conductive layer, 153: insulating layer, 155: common electrode, 156: insulating layer, 156B: insulating layer, 156C: insulating layer, 156G: insulating layer, 156R: insulating layer, 157: light-shielding layer, 158: sacrificial layer, 158B: sacrificial layer , 158G: sacrificial layer, 158R: sacrificial layer, 166: conductive layer, 174: insulating layer, 175: insulating layer, 177: pixel portion, 178: pixel, 178a: pixel, 178b: pixel, 180: organic resin layer, 181: recess, 181a: recess, 181b: recess, 181c: recess, 182: microlens, 201: transistor, 204: connection portion, 205: transistor, 211: insulating layer, 213: insulating layer, 214: insulating layer, 215: insulating layer, 221: conductive layer, 222a: conductive layer, 222b: conductive layer, 223: conductive layer, 224 B: Conductive layer, 224C: Conductive layer, 224G: Conductive layer, 224R: Conductive layer, 231: Semiconductor layer, 240: Capacitor, 241: Conductive layer, 242: Connection layer, 243: Insulating layer, 245: Conductive layer, 254: Insulating layer, 255: Insulating layer, 256: Plug, 261: Insulating layer, 271: Plug, 280: Display module, 281: Display unit, 282: Circuit unit, 283: Pixel circuit unit, 283a: Pixel circuit, 284: Pixel unit, 284a: Pixel, 285: Terminal unit, 286: Wiring unit, 290: FPC, 291: Substrate, 292: Substrate, 301 : substrate, 310: transistor, 311: conductive layer, 312: low resistance region, 313: insulating layer, 314: insulating layer, 315: element isolation layer, 317: light-shielding layer, 351: substrate, 352: substrate, 353: FPC, 354: IC, 355: wiring, 356: circuit, 501: first electrode, 501c: first light-emitting unit, 501d: first light-emitting unit, 502: second electrode, 502c: second light-emitting unit, 502d: second light-emitting unit, 511: first light-emitting unit, 512: second light-emitting unit, 513: intermediate layer,

Claims

1. A method for synthesizing an organic compound, comprising reacting an organic compound represented by general formula (G0) with a transition metal catalyst, heavy water, and hydrogen molecules to obtain an organic compound represented by general formula (G1). 【Chemical 1】 【Chemistry 2】 (In general formula (G0) and general formula (G1), Y represents oxygen or sulfur, and R １ ~R ４ , and R １１ ~R １４ each independently represents any one of hydrogen (including deuterium), a hydroxyl group, an organic boron group, a boronic acid, an organic tin group, and a halogen; １ ~X ４ each independently represents carbon or nitrogen, and X １ ~X ４ Any one or two of R ５ ~R ８ , and R １５ ~R １８ each independently represents hydrogen (including deuterium), a hydroxyl group, an organic boron group, a boronic acid, an organic tin group, or a halogen; and X １ ~X ４ is nitrogen, R bonded to the nitrogen ５ ~R ８ , and R １５ ~R １８ is vacant, and R １１ ~R １８ The total number of deuterium atoms to be substituted into R １ ~R ８ is greater than the total number of deuterium atoms substituted into

2. A method for synthesizing an organic compound, comprising reacting an organic compound represented by general formula (G0) with a transition metal catalyst, heavy water, and a hydrogen molecule donor to obtain an organic compound represented by general formula (G1). 【Chemistry 3】 【Chemistry 4】 (In general formula (G0) and general formula (G1), Y represents oxygen or sulfur, and R １ ~R ４ , and R １１ ~R １４ each independently represents any one of hydrogen (including deuterium), a hydroxyl group, an organic boron group, a boronic acid, an organic tin group, and a halogen; １ ~X ４ each independently represents carbon or nitrogen, and X １ ~X ４ Any one or two of R ５ ~R ８ , and R １５ ~R １８ each independently represents hydrogen (including deuterium), a hydroxyl group, an organic boron group, a boronic acid, an organic tin group, or a halogen; and X １ ~X ４ is nitrogen, R bonded to the nitrogen ５ ~R ８ , and R １５ ~R １８ is vacant, and R １１ ~R １８ The total number of deuterium atoms to be substituted into R １ ~R ８ is greater than the total number of deuterium atoms substituted into

3. In claim 2, The method for synthesizing an organic compound, wherein the hydrogen molecule donor is formic acid, ammonia borane, or methanol.

4. In claim 2, The method for synthesizing an organic compound, wherein the hydrogen molecule donor is 2-propanol.

5. 5. The method for synthesizing an organic compound according to claim 1, wherein the transition metal catalyst contains a platinum group element.

6. An organic compound represented by general formula (G1): 【Chemistry 5】 (In general formula (G1), R １１ ~R １４ Each independently represents one of hydrogen (including deuterium), a hydroxyl group, or a halogen. １ ~X ４ each independently represents carbon or nitrogen, and X １ ~X ４ One or two of R is nitrogen. １５ ~R １８ each independently represents hydrogen (including deuterium), a hydroxyl group, or a halogen; X １ ~X ４ When is nitrogen, R bonded to the nitrogen １５ ~R １８ represents a vacant position. Y represents oxygen or sulfur. １１ ~R １８ At least one of the atoms is deuterium.)

7. An organic compound represented by structural formula (100). 【Chemistry 6】

8. An organic compound represented by the structural formula (100), an organic compound represented by the structural formula (100-1), or a mixture thereof. 【Chemistry 7】

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