Light-emitting device, light-emitting apparatus, electronic device and lighting apparatus

Abstract

To provide a novel light-emitting device, a light-emitting device with excellent luminous efficiency, a light-emitting device with excellent lifetime, or a light-emitting device with a low driving voltage.SOLUTION: A light-emitting device includes an anode, a cathode, and an EL layer present between the anode and the cathode. The EL layer has a light-emitting layer and an electron transport layer. The electron transport layer is present between the light-emitting layer and the cathode. The electron transport layer includes an electron transport material. The electron transport material is an organic compound having a first skeleton, a second skeleton, and a third skeleton. The first skeleton has a function of transporting electrons. The second skeleton has a function of accepting holes. The third skeleton has a single ring and a heterocyclic aromatic ring that is π electron deficient type.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] One aspect of the present invention is a light-emitting device, a light-emitting element, a display module, and a lighting module. The present invention relates to a display device, a light-emitting device, an electronic device, and a lighting device. The technical field of one embodiment of the invention disclosed in the present specification and the like is not limited to the following: Alternatively, one aspect of the present invention relates to a process, a machine, , manufacture, or composition of matter Therefore, the technical field of one embodiment of the present invention disclosed in this specification more specifically includes: Semiconductor device, display device, liquid crystal display device, light-emitting device, lighting device, power storage device, memory device, imaging device Examples include devices, methods for driving them, and methods for manufacturing them. . [Background technology]

[0002] Electroluminescence (EL) using organic compounds Light-emitting devices (organic EL elements) that utilize these luminescence are being put to practical use. The basic structure of the device is a pair of electrodes sandwiching an organic compound layer (EL layer) containing a light-emitting material. When a voltage is applied to this element, carriers are injected and the recombination of these carriers occurs. By utilizing the energy, light can be emitted from the light-emitting material.

[0003] Since such light-emitting devices are self-luminous, when they are used as pixels in a display, It has advantages such as high visibility and no need for backlighting compared to flat panel displays. The light-emitting device is suitable for use as a display element. Another major advantage is that it can be manufactured to be thin and lightweight. It is one of the signs.

[0004] In addition, these light-emitting devices can be fabricated with a continuous two-dimensional light-emitting layer. This is a point light source, such as an incandescent bulb or LED, and This is a feature that is difficult to obtain with linear light sources such as fluorescent lamps, so it is used as a surface light source that can be applied to lighting, etc. It is also highly useful as a tool.

[0005] Displays and lighting devices using such light-emitting devices are suitable for use in a variety of electronic devices. However, research and development is being conducted to find light-emitting devices with better efficiency and life span. There are.

[0006] In Patent Document 1, the HOM of the hole injection layer is provided between the hole transport layer in contact with the hole injection layer and the light emitting layer. A hole-transporting material having a HOMO level between the O level and the HOMO level of the host material is provided. The configuration is disclosed.

[0007] The properties of light-emitting devices have improved dramatically, but many other properties, including efficiency and durability, remain. It must be said that this is still insufficient to meet the high level of demands on the environment. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] International Publication No. 2011 / 065136 Brochure Summary of the Invention [Problem to be solved by the invention]

[0009] In view of the above, an object of one embodiment of the present invention is to provide a novel light-emitting device. The object of the present invention is to provide a light-emitting device having good luminous efficiency or a long life. The present invention aims to provide a light-emitting device with a low driving voltage. Another object of the present invention is to provide a novel compound.

[0010] In another embodiment of the present invention, a light-emitting device, an electronic device, and a display device each having high reliability are provided. Another object of the present invention is to provide a light-emitting device with low power consumption. The present invention aims to provide a device, an electronic device, and a display device.

[0011] The present invention is intended to solve any one of the above problems. [Means for solving the problem]

[0012] One aspect of the present invention is a light-emitting diode (LED) having an anode, a cathode, and an EL layer located between the anode and the cathode. The EL layer has a light-emitting layer and an electron transport layer, and the electron transport layer is connected to the light-emitting layer and the cathode. the electron transport layer is located between the first electrode and the second electrode, and the electron transport layer has an electron transport material, the electron transport material being an organic compound having a skeleton of the formula: the second skeleton has a function of accepting holes; and the third skeleton has a function of transporting electrons. The backbone is a light-emitting device having a monocyclic heteroaromatic ring that is π-electron deficient.

[0013] Alternatively, another aspect of the present invention is a device comprising an anode, a cathode, and a cathode-like electrode located between the anode and the cathode. The EL layer has a light-emitting layer and an electron transport layer, and the electron transport layer The electron transport material has a first skeleton, a second skeleton, and a third skeleton. The first skeleton has a function of transporting electrons, and the second skeleton has a function of accepting holes, and the second skeleton has two or more fused aromatic hydrocarbon rings. The third skeleton is a light-emitting device having a monocyclic heteroaromatic ring that is π-electron deficient. It's a vice.

[0014] Alternatively, another aspect of the present invention is a compound having the above structure, wherein the second skeleton is a fused ring of three or more rings. A light-emitting device having an aromatic hydrocarbon ring.

[0015] Alternatively, another embodiment of the present invention is a compound having the above structure, wherein the second skeleton is a tricyclic or tetracyclic compound. A light-emitting device that is a fused aromatic hydrocarbon ring.

[0016] Alternatively, another embodiment of the present invention is a compound having the above structure, wherein the carbon atom forming the ring of the second skeleton is The number of the light-emitting elements is 14 or more.

[0017] Alternatively, another aspect of the present invention is a compound according to the above structure, wherein the fused aromatic hydrocarbon ring is a six-membered ring. It is a light-emitting device that consists only of

[0018] Alternatively, another embodiment of the present invention is a compound having the above structure, wherein the second skeleton is an anthracene ring. , phenanthrene ring, benzofluorene ring, tetracene ring, chrysene ring, triphenylene and a light-emitting device comprising either a pyrene ring or a pyrene ring.

[0019] Alternatively, another embodiment of the present invention is a compound having the above structure, wherein the second skeleton is an anthracene ring. It is a light-emitting device.

[0020] Alternatively, in the above structure, the electron transport layer may contain a metal, a metal salt, or The light-emitting device further comprises a metal oxide or an organometallic salt.

[0021] Alternatively, another aspect of the present invention is a device comprising an anode, a cathode, and a cathode-like electrode located between the anode and the cathode. The EL layer has a hole injection layer, a light emitting layer, and an electron transport layer, and the hole the injection layer is located between the anode and the light-emitting layer, and the electron transport layer is located between the light-emitting layer and The hole injection layer is located between the cathode and the hole transport material and the hole acceptor material. The electron transport layer comprises an electron transport material and a metal, a metal salt, a metal oxide, or an organic metal salt. The hole transport material has a hole transport property and a HOMO level of −5.7 the acceptor material is an organic compound having a molecular weight of 1.2 eV or more and -5.4 eV or less, and the hole transport material is The electron transport material is a substance that exhibits electron accepting properties to a material, and the electron transport material comprises a first skeleton, a second skeleton, and and a third skeleton, wherein the first skeleton has a function of transporting electrons. The second skeleton has a function of accepting holes, and the third skeleton is a single ring and a π-electron A light-emitting device having a heteroaromatic ring that is electron-deficient.

[0022] Alternatively, another embodiment of the present invention is a compound having the above structure, wherein the second skeleton has two to four rings. and a light-emitting device in which the aromatic hydrocarbon ring is a fused aromatic hydrocarbon ring.

[0023] Alternatively, another embodiment of the present invention is a compound having the above structure, wherein the second skeleton is a tricyclic or tetracyclic compound. A light-emitting device that is a fused aromatic hydrocarbon ring.

[0024] Alternatively, another aspect of the present invention is a polymerizable compound having the above structure, wherein the second skeleton is a naphthalene ring, Fluorene ring, anthracene ring, phenanthrene ring, tetracene ring, chrysene ring, triflate ring The light-emitting device includes one of a phenylene ring and a pyrene ring.

[0025] Alternatively, another embodiment of the present invention is a compound having the above structure, wherein the carbon atom forming the ring of the second skeleton is The number of the light-emitting elements is 14 or more.

[0026] Alternatively, another aspect of the present invention is a compound according to the above structure, wherein the fused aromatic hydrocarbon ring is a six-membered ring. It is a light-emitting device that consists only of

[0027] Alternatively, another embodiment of the present invention is a compound having the above structure, wherein the second skeleton is an anthracene ring. It is a light-emitting device.

[0028] Alternatively, in the above structure, another embodiment of the present invention is a semiconductor device in which the acceptor material is an organic compound It is a light-emitting device.

[0029] Alternatively, another embodiment of the present invention is a method for manufacturing a semiconductor device, comprising the steps of: or an organic metal salt, a luminescent device which is a metal complex having an alkali metal or an alkaline earth metal. It's a vice.

[0030] Alternatively, another embodiment of the present invention is a method for manufacturing a semiconductor device, comprising the steps of: or organometallic salts containing nitrogen- and oxygen-containing ligands and alkali metal or alkaline earth metal and a metal complex having the formula:

[0031] Alternatively, another embodiment of the present invention is a method for manufacturing a semiconductor device, comprising the steps of: or an organometallic salt, which is a compound having a ligand containing an 8-hydroxyquinolinato structure and a monovalent metal ion. The light-emitting device is a metal complex having

[0032] Alternatively, another embodiment of the present invention is a method for manufacturing a semiconductor device, comprising the steps of: or the organometallic salt is a lithium complex having a ligand containing an 8-hydroxyquinolinato structure. It is a light-emitting device.

[0033] Alternatively, in the above-described structure, another aspect of the present invention is the first electron transport material. and the third skeleton are bonded via the second skeleton.

[0034] Alternatively, another aspect of the present invention is a method for manufacturing a semiconductor device having the above-described structure, wherein the LUMO of the electron transport material is is a light-emitting device that is mainly distributed in the first framework.

[0035] Alternatively, another aspect of the present invention is a compound according to the above structure, wherein the first skeleton is a condensed structure containing nitrogen. A light-emitting device containing an aromatic ring or a triazine ring.

[0036] Alternatively, another aspect of the present invention is a method for manufacturing a semiconductor device according to the above structure, wherein the first skeleton has two or more nitrogen atoms. It is a light emitting device having a light emitting element.

[0037] Alternatively, another embodiment of the present invention is a compound having the above structure, wherein the first skeleton is a quinoxaline ring. , dibenzo[h,g]quinoxaline ring, triazine ring and benzofuropyrimidine ring A light-emitting device is a framework including any one of the above.

[0038] Alternatively, another embodiment of the present invention is a compound having the above structure, wherein the first skeleton is a quinoxaline ring. The light-emitting device is a scaffold comprising:

[0039] Alternatively, another embodiment of the present invention is a compound having the above-described structure, wherein the HOMO of the electron transport material is is a light-emitting device in which the second backbone is mainly distributed.

[0040] Alternatively, another embodiment of the present invention is a compound having the above structure, wherein the third skeleton has a nitrogen atom. The present invention relates to a light-emitting device that includes a heteroaromatic ring, which is a six-membered ring.

[0041] Alternatively, another embodiment of the present invention is a compound having the above structure, wherein the third skeleton is a pyridine ring, ... The light-emitting device is one of an imidine ring, a pyrazine ring, and a triazine ring.

[0042] Alternatively, another aspect of the present invention is the above-mentioned structure, wherein the third skeleton is the second skeleton. a nitrogen atom is bonded to the second skeleton so that the nitrogen atom is at the β-position relative to the carbon atom bonded to It is a device.

[0043] Alternatively, another aspect of the present invention is a compound having the above-mentioned structure, wherein the third skeleton is a pi-substituted ... The light-emitting device is a lysine ring, a pyrimidine ring substituted at the 5-position, or a pyrazine ring.

[0044] Alternatively, another aspect of the present invention is a semiconductor device having the above-described structure, wherein the electron transport layer is in contact with the cathode. It is a light-emitting device.

[0045] Alternatively, another aspect of the present invention is a light-emitting device according to the above structure, wherein the light-emitting layer contains a host material and a light-emitting and a material, the light-emitting material being a blue fluorescent light-emitting device.

[0046] Another embodiment of the present invention is a light-emitting device including any one of the above light-emitting devices, a sensor, and an operation button. The electronic device has a touch panel, a speaker, or a microphone.

[0047] Another embodiment of the present invention is a light-emitting device including any one of the above light-emitting devices, a transistor, and a Alternatively, the light emitting device may include a substrate.

[0048] Another aspect of the present invention is a lighting device including any one of the above light-emitting devices and a housing. It is a bright device.

[0049] Alternatively, another embodiment of the present invention is a polymer having a first skeleton, a second skeleton, and a third skeleton, A compound used in an electron transport layer, wherein the first skeleton has a function of transporting electrons, The second skeleton has a function of accepting holes, and the third skeleton is a monocyclic and π-electron-deficient structure. It is a compound that has a heteroaromatic ring that is foot-shaped.

[0050] In this specification, the term "light-emitting device" includes an image display device using a light-emitting device. In addition, a connector such as anisotropic conductive film or TCP (Tape) is attached to the light-emitting device. Module with Carrier Package attached, printed on TCP Modules with wiring boards or light-emitting devices with COG (Chip On Glass) s) method, a module in which an IC (integrated circuit) is directly mounted may also be included in the category of light-emitting device. Furthermore, lighting fixtures and the like may include a light-emitting device. [Effects of the Invention]

[0051] According to one embodiment of the present invention, a novel light-emitting device can be provided. It is possible to provide a light-emitting device having good luminous efficiency. It is possible.

[0052] In another embodiment of the present invention, a light-emitting device, an electronic device, and a display device each having high reliability are provided. In another embodiment of the present invention, a light-emitting device with low power consumption can be provided. An electronic device and a display device can each be provided.

[0053] The description of these effects does not preclude the existence of other effects. The embodiment does not necessarily have to have all of these effects. , the specification, drawings, claims, etc., and It is possible to extract other effects from the claims and other descriptions. [Brief explanation of the drawings]

[0054] [Figure 1] 1(A), 1(B), and 1(C) are schematic diagrams of light-emitting devices. [Figure 2] 2(A) and 2(B) are conceptual diagrams of an active matrix light emitting device. [Figure 3] 3(A) and 3(B) are conceptual diagrams of an active matrix light emitting device. [Figure 4] FIG. 4 is a conceptual diagram of an active matrix light emitting device. [Figure 5] 5(A) and 5(B) are diagrams showing the lighting device. [Figure 6] 6(A), 6(B1), 6(B2) and 6(C) are diagrams showing electronic devices. [Figure 7] 7(A), 7(B) and 7(C) are diagrams showing electronic devices. [Figure 8] FIG. 8 is a diagram showing a lighting device. [Figure 9] FIG. 9 is a diagram showing a lighting device. [Figure 10] FIG. 10 is a diagram showing an in-vehicle display device and a lighting device. [Figure 11] 11(A), 11(B) and 11(C) are diagrams showing electronic devices. [Figure 12] 12(A) and 12(B) are diagrams showing electronic devices. [Figure 13] FIG. 13 is a graph showing the luminance-current density characteristics of the light-emitting device 1 and the comparative light-emitting device 1. As shown in FIG. [Figure 14] FIG. 14 is a graph showing the current efficiency-luminance characteristics of the light-emitting device 1 and the comparative light-emitting device 1. In FIG. [Figure 15] FIG. 15 is a graph showing the luminance-voltage characteristics of the light-emitting device 1 and the comparative light-emitting device 1. As shown in FIG. [Figure 16] FIG. 16 is a graph showing the current-voltage characteristics of the light-emitting device 1 and the comparative light-emitting device 1. As shown in FIG. [Figure 17] FIG. 17 is a graph showing the external quantum efficiency-luminance characteristics of the light-emitting device 1 and the comparative light-emitting device 1. In FIG. [Figure 18] FIG. 18 is a graph showing the emission spectra of the light-emitting device 1 and the comparative light-emitting device 1. As shown in FIG. [Figure 19] FIG. 19 is a graph showing the normalized luminance-time change characteristics of the light-emitting device 1 and the comparative light-emitting device 1. In FIG. [Figure 20] FIG. 20 is a diagram showing the structure of the measuring element. [Figure 21] FIG. 21 is a graph showing the current density-voltage characteristics of the measuring device. [Figure 22] FIG. 22 is a graph showing the frequency characteristics of the calculated capacitance C of ZADN:Liq(1:1) at a DC voltage of 7.0 V. [Figure 23] FIG. 23 is a graph showing the frequency characteristics of −ΔB of ZADN:Liq(1:1) at a DC voltage of 7.0 V. [Figure 24] FIG. 24 is a diagram showing the electric field strength dependence of electron mobility in each organic compound. [Figure 25] 25(A) and 25(B) show the 1H NMR spectrum of BfpmPPyA. [Figure 26] 26(A) and 26(B) show the 1H NMR spectrum of DBqPPyA. [Figure 27] 27(A) and 27(B) show the 1H NMR spectrum of NfprPPyA. [Figure 28]FIG. 28 is a graph showing the luminance-current density characteristics of light-emitting devices 2 to 4. In FIG. [Figure 29] FIG. 29 is a graph showing the current efficiency-luminance characteristics of light-emitting devices 2 to 4. In FIG. [Figure 30] FIG. 30 is a diagram showing the luminance-voltage characteristics of light-emitting devices 2 to 4. In FIG. [Figure 31] FIG. 31 is a diagram showing the current-voltage characteristics of light-emitting devices 2 to 4. In FIG. [Figure 32] FIG. 32 is a graph showing the external quantum efficiency-luminance characteristics of light-emitting devices 2 to 4. In FIG. [Figure 33] FIG. 33 shows the emission spectra of light-emitting devices 2 to 4. As shown in FIG. [Figure 34] FIG. 34 is a graph showing the normalized luminance vs. time change characteristics of light-emitting devices 2 to 4. In FIG. DETAILED DESCRIPTION OF THE INVENTION

[0055] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The present invention is not limited to the above description, and the form and details thereof may be changed without departing from the spirit and scope of the present invention. It will be readily apparent to those skilled in the art that various modifications may be made to the present invention. It should not be construed as being limited to the description of the embodiments.

[0056] (Embodiment 1) FIG. 1A shows a light-emitting device according to one embodiment of the present invention. The device has an anode 101, a cathode 102, and an EL layer 103. It has at least a light-emitting layer 113 and an electron-transporting layer 114 .

[0057] The EL layer 103 in FIG. 1(A) includes a light-emitting layer 113 and an electron transport layer 114 as well as a positive Although the hole injection layer 111 and the hole transport layer 112 are shown, the EL layer 103 is not limited to these. As shown in FIG. 1(B), an electron injection layer 115 may be provided. The transport layer 112 has a first hole transport layer 112-1 and a second hole transport layer 112-2. The electron transport layer 114 may include a first electron transport layer 114-1 and a second electron transport layer 114-2. 14-2.

[0058] In the light-emitting device according to one embodiment of the present invention, the electron-transporting material used in the electron-transporting layer 114 is , has a first skeleton, a second skeleton, and a third skeleton, each of which has a different function.

[0059] The first skeleton is a skeleton having a function of transporting electrons. O is mainly distributed in the first skeleton, and the electron transport ability of this electron transport material is The first skeleton contains nitrogen to exhibit electron transport properties. Preferably, the first skeleton has a fused aromatic ring or a triazine skeleton containing LUMO. In other words, the electron-accepting property of the first skeleton is increased, and the electron-accepting property of the third skeleton is increased. In order to facilitate the formation of a compound having a nitrogen atom, the first skeleton preferably contains two or more nitrogen atoms. It is particularly preferred that the two or more nitrogen atoms are located on a six-membered aromatic ring. Examples of skeletons that can be suitably used as the first skeleton include a quinoxaline ring, a dibenzo Examples include benzo[h,g]quinoxaline ring, triazine ring, and benzofuropyrimidine ring. Among these, a skeleton containing a quinoxaline ring is preferred.

[0060] The second skeleton is a skeleton having a function of accepting holes. In addition, in order to accept holes, the second bone It is more preferable that the ring has three or more fused aromatic hydrocarbon rings. The hydrogen rings are preferably six or less in order to maintain sublimability and moderate solubility. From the viewpoint of maintaining the energy gap, it is more preferable that the number of rings is 4 or less. In order to achieve this, the number of carbon atoms forming the fused aromatic hydrocarbon ring must be 14 or more. In addition, in consideration of stability in the excited state, the fused aromatic hydrocarbon ring is preferably 6 It is preferable that the skeleton is composed of only membered rings. Specific examples of suitable fused aromatic hydrocarbon rings include naphthalene rings, fluorene rings, anthracene rings, and the like. acene ring, phenanthrene ring, benzofluorene ring, tetracene ring, chrysene ring, triphenanthrene ring Among these, the aryl ring and the pyrene ring are particularly preferred. Anthracene rings are preferred because they can provide chemical stability. In particular, it is preferable that the HOMO of the electron transport material is distributed.

[0061] The third skeleton is a monocyclic heteroaromatic ring that is π-electron deficient and has electron injection properties from the cathode. It is preferable that the ring is a six-membered ring having a nitrogen atom so as to have the following structure. Specifically, pyridine ring, pyrimidine ring, pyrazine ring and triazine ring are preferred. When the carbon atom is bonded to the skeleton of the It is preferable that the atom at the β-position is nitrogen. The ring is preferably a pyridine ring substituted at the 3-position or a pyrimidine ring substituted at the 5-position. This improves contact with the cathode and reduces the driving voltage on the high-luminance side. This is because the third skeleton has such a structure. A light-emitting device with good characteristics and low driving voltage can be obtained without providing an electron injection layer between the first and second electrodes. can be obtained.

[0062] In addition, when the first skeleton and the third skeleton are bonded, the LUMO may be distributed to both. Preferably, these skeletons are linked via a second skeleton, as this increases the bond strength.

[0063] The light-emitting layer 113 contains a host material and a light-emitting material. The composition may also contain other materials different from the light-emitting material. It may be a laminate of two different layers.

[0064] The luminescent material may be a fluorescent material, a phosphorescent material, or a thermally activated delayed fluorescence (T The material may be a material showing the ADF (Anti-Dysphasia Factor), or other light-emitting materials. In one embodiment of the present invention, the light-emitting layer 113 may be a fluorescent layer. It is more suitable for the layer to emit light, particularly for the layer to emit blue fluorescent light.

[0065] In the light-emitting layer 113, materials that can be used as fluorescent materials include, for example: 5,6-bis[4-(10-phenyl-9-anthryl)phenyl]-2,2'-bipyridine PAP2BPy, 5,6-bis[4'-(10-phenyl-9-anthracene] N, N'-diphenyl-N,N'-bis[4-(9-phenyl-9H-fluoren-9-yl] )phenyl]pyrene-1,6-diamine (abbreviation: 1,6FLPAPrn), N,N'-biphenyl bis(3-methylphenyl)-N,N'-bis[3-(9-phenyl-9H-fluorene 9-yl)phenyl]pyrene-1,6-diamine (abbreviation: 1,6mMemFLPAPrn ), N,N'-bis[4-(9H-carbazol-9-yl)phenyl]-N,N'-di Phenylstilbene-4,4'-diamine (abbreviation: YGA2S), 4-(9H-carbazo (4'-(10-phenyl-9-yl)-4'-(10-phenyl-9-anthryl)triphenylamine (abbreviation Name: YGAPA), 4-(9H-carbazol-9-yl)-4'-(9,10-diphenyl N,9-diphenyl-2-anthryltriphenylamine (abbreviation: 2YGAPPA) N-[4-(10-phenyl-9-anthryl)phenyl]-9H-carbazole -3-amine (abbreviation: PCAPA), Perylene, 2,5,8,11-tetra-tert- Butylperylene (TBP), 4-(10-phenyl-9-anthryl)-4'-( 9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBAP) A), N,N''-(2-tert-butylanthracene-9,10-diyldi-4,1 -phenylene)bis[N,N',N'-triphenyl-1,4-phenylenediamine]( Abbreviation: DPABPA), N,9-diphenyl-N-[4-(9,10-diphenyl-2- anthryl)phenyl]-9H-carbazol-3-amine (abbreviation: 2PCAPPA), N-[4-(9,10-diphenyl-2-anthryl)phenyl]-N,N',N'- N,N,N',N-triphenyl-1,4-phenylenediamine (abbreviation: 2DPAPPA) ',N'',N'',N''',N'''-Octaphenyldibenzo[g,p]chrysene -2,7,10,15-tetraamine (abbreviation: DBC1), Coumarin 30, N-(9,1 0-Diphenyl-2-anthryl)-N,9-diphenyl-9H-carbazole-3-a amine (abbreviation: 2PCAPA), N-[9,10-bis(1,1'-biphenyl-2-yl)] )-2-anthryl]-N,9-diphenyl-9H-carbazol-3-amine (abbreviation: 2PCABPhA), N-(9,10-diphenyl-2-anthryl)-N,N',N' -Triphenyl-1,4-phenylenediamine (abbreviation: 2DPAPA), N-[9,10 -bis(1,1'-biphenyl-2-yl)-2-anthryl]-N,N',N'-tri Phenyl-1,4-phenylenediamine (abbreviation: 2DPABPhA), 9,10-bis( 1,1'-biphenyl-2-yl)-N-[4-(9H-carbazol-9-yl)phenyl] N,N,nyl]-N-phenylanthracen-2-amine (abbreviation: 2YGABPhA), 9-Triphenylanthracen-9-amine (abbreviation: DPhAPhA), Coumarin 545 T, N,N'-diphenylquinacridone (abbreviation: DPQd), rubrene, 5,12-bis (1,1'-biphenyl-4-yl)-6,11-diphenyltetracene (abbreviation: BPT ), 2-(2-{2-[4-(dimethylamino)phenyl]ethenyl}-6-methyl-4 H-pyran-4-ylidene)propanedinitrile (abbreviation: DCM1), 2-{2-methyl -6-[2-(2,3,6,7-tetrahydro-1H,5H-benzo[ij]quinolizine -9-yl)ethenyl]-4H-pyran-4-ylidene}propanedinitrile (abbreviation: D CM2), N,N,N',N'-tetrakis(4-methylphenyl)tetracene-5,1 1-diamine (abbreviation: p-mPhTD), 7,14-diphenyl-N,N,N',N'- Tetrakis(4-methylphenyl)acenaphtho[1,2-a]fluoranthene-3,10 -diamine (abbreviation: p-mPhAFD), 2-{2-isopropyl-6-[2-(1,1 ,7,7-tetramethyl-2,3,6,7-tetrahydro-1H,5H-benzo[ij] Quinolizin-9-yl)ethenyl]-4H-pyran-4-ylidene}propanedinitrile (abbreviation: DCJTI), 2-{2-tert-butyl-6-[2-(1,1,7,7-tetramethyl- tetramethyl-2,3,6,7-tetrahydro-1H,5H-benzo[ij]quinolizine- 9-yl)ethenyl]-4H-pyran-4-ylidene}propanedinitrile (abbreviation: DC JTB), 2-(2,6-bis{2-[4-(dimethylamino)phenyl]ethenyl}- 4H-pyran-4-ylidene)propanedinitrile (abbreviation: BisDCM), 2-{2, 6-bis[2-(8-methoxy-1,1,7,7-tetramethyl-2,3,6,7-tetramethyl- 4H-pyrahydro-1H,5H-benzo[ij]quinolizin-9-yl)ethenyl N,N'-diphenyl-4-ylidene}propanedinitrile (abbreviation: BisDCJTM), N,N'-(1,6-pyrene-diyl)bis[(6-phenylbenzo[b]naphtho] [1,2-d]furan)-8-amine] (abbreviation: 1,6BnfAPrn-03), 3,1 O-Bis[N-(9-phenyl-9H-carbazol-2-yl)-N-phenylamino] ]naphtho[2,3-b;6,7-b']bisbenzofuran (abbreviation: 3,10PCA2Nb f(IV)-02), 3,10-bis[N-(dibenzofuran-3-yl)-N-phenyl 3,10Fr A2Nbf(IV)-02), etc. In particular, 1,6FLPAPrn and 1,6m Instead of pyrenediamine compounds such as MemFLPAPrn and 1,6BnfAPrn-03, The condensed aromatic diamine compound represented by the formula (I) has a high hole trapping property and is excellent in luminous efficiency and reliability. This is preferable because

[0066] In the light-emitting layer 113, when a phosphorescent material is used as the light-emitting center material, Possible materials include, for example, tris{2-[5-(2-methylphenyl)-4-(2, 6-dimethylphenyl)-4H-1,2,4-triazol-3-yl-κN2]phenyl {Ir(mpptz-dmp)}iridium(III) (abbreviation: [Ir(mpptz-dmp)3]), tris (5-methyl-3,4-diphenyl-4H-1,2,4-triazolato)iridium(I II) (abbreviation: [Ir(Mptz)3]), tris[4-(3-biphenyl)-5-isopropyl Propyl-3-phenyl-4H-1,2,4-triazolato]iridium(III) (abbreviation Title: Organic compounds with a 4H-triazole skeleton, such as [Ir(iPrptz-3b)3] Metallic iridium complexes and tris[3-methyl-1-(2-methylphenyl)-5-phenyl [Ir(Mptz)]triazolato[1H-1,2,4-triazolato]iridium(III) 1-mp)3]), tris(1-methyl-5-phenyl-3-propyl-1H-1,2, 4-Triazolato)iridium(III) (abbreviation: [Ir(Prtz1-Me)3]) Organometallic iridium complexes with 1H-triazole skeletons, such as fac-tris[ 1-(2,6-diisopropylphenyl)-2-phenyl-1H-imidazole]iridine Ir(iPrpmi)3), tris[3-(2,6-dimethyl phenyl)-7-methylimidazo[1,2-f]phenanthridinato]iridium(I II) Imidazole skeleton such as [Ir(dmpimpt-Me)3] Organometallic iridium complexes and bis[2-(4',6'-difluorophenyl)pyridinyl]pyridinyl]pyridinyl To-N,C 2’ ]Iridium(III) tetrakis(1-pyrazolyl)borate (abbreviation: FIr6), bis[2-(4',6'-difluorophenyl)pyridinato-N,C 2’ ] Iridium(III) picolinate (abbreviation: FIrpic), bis{2-[3',5'- Bis(trifluoromethyl)phenyl]pyridinato-N,C 2’}Iridium(III) Picolinate (abbreviation: [Ir(CF3ppy)2(pic)]), bis[2-(4',6 '-Difluorophenyl)pyridinato-N,C 2’ ]iridium(III) acetylacetone Phenylpyridine derivatives with electron-withdrawing groups such as tonato (abbreviation: FIr(acac)) Organometallic iridium complexes with conductive ligands are known. These emit blue phosphorescence. The compound shown in FIG. 1 has an emission peak at 440 nm to 520 nm.

[0067] Furthermore, materials that can be used for the light-emitting layer 113 include tris(4-methyl-6-phenyl) Iridium(III) (abbreviation: [Ir(mppm)3]), tris(4 -t-butyl-6-phenylpyrimidinato)iridium(III) (abbreviation: [Ir(tB uppm)3]), (acetylacetonato)bis(6-methyl-4-phenylpyrimidina Iridium(III) (abbreviation: [Ir(mppm)2(acac)]), (acetyl acetonato)bis(6-tert-butyl-4-phenylpyrimidinato)iridium(I II) (abbreviation: [Ir(tBuppm)2(acac)]), (acetylacetonato)bi Bis[6-(2-norbornyl)-4-phenylpyrimidinato]iridium(III) Name: [Ir(nbppm)2(acac)]), (acetylacetonato)bis[5-methyl Iridium(III) Abbreviation: [Ir(mpmppm)2(acac)]), (acetylacetonato)bis(4, 6-diphenylpyrimidinato)iridium(III) (abbreviation: [Ir(dppm)2(a cac)]), and organometallic iridium complexes with pyrimidine skeletons, such as (acetylacetone). cetonato)bis(3,5-dimethyl-2-phenylpyrazinato)iridium(III)( Abbreviation: [Ir(mppr-Me)2(acac)]), (acetylacetonato)bis(5 -isopropyl-3-methyl-2-phenylpyrazinato)iridium(III) (abbreviation: Organometallic pyrazine skeletons such as [Ir(mppr-iPr)2(acac)] Iridium complexes and tris(2-phenylpyridinato-N,C 2’ ) Iridium (III ) (abbreviation: [Ir(ppy)3]), bis(2-phenylpyridinato-N,C 2’ ) Iri Ir(III) acetylacetonate (abbreviation: [Ir(ppy)2(acac)]), Bis(benzo[h]quinolinato)iridium(III) acetylacetonate (abbreviation: [ Ir(bzq)2(acac)]), tris(benzo[h]quinolinato)iridium (I II) (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( In addition to organometallic iridium complexes with a pyridine skeleton, such as tris(acac)], Cetylacetonato)(monophenanthroline)terbium(III) (abbreviation: [Tb(a These include rare earth metal complexes such as phenylalanine (Phen)]. It is a compound that exhibits phosphorescence and has an emission peak at 500 nm to 600 nm. Organometallic iridium complexes with pyrimidine skeletons are also remarkably superior in reliability and luminescence efficiency. This is particularly preferred because

[0068] In addition, materials that can be used for the light-emitting layer 113 include (diisobutyrylmethanato)bis(diisobutyrylmethanato) [4,6-bis(3-methylphenyl)pyrimidinato]iridium(III) (abbreviation: [ Ir(5mdppm)2(dibm)]), bis[4,6-bis(3-methylphenyl) [Ir(5md ppm)2(dpm)]), bis[4,6-di(naphthalen-1-yl)pyrimidinato] (Dipivaloylmethanato)iridium(III) (abbreviation: [Ir(d1npm)2(dp m)]) and organometallic iridium complexes with pyrimidine skeletons, such as (acetylacetonate Nato)bis(2,3,5-triphenylpyrazinato)iridium(III) (abbreviation: [I r(tppr)2(acac)]), bis(2,3,5-triphenylpyrazinate)(di (pivaloylmethanato)iridium(III) (abbreviation: [Ir(tppr)2(dpm)] ), (acetylacetonato)bis[2,3-bis(4-fluorophenyl)quinoxalina pyridinium(III) (abbreviation: [Ir(Fdpq)2(acac)]) Organometallic iridium complexes with dithiazolinone skeletons and tris(1-phenylisoquinolinato-N ,C 2’ ) Iridium(III) (abbreviation: [Ir(piq)3]), bis(1-phenyl Isoquinolinato-N,C 2’ ) Iridium(III) acetylacetonate (abbreviation: [I Organometallic iridium complexes with pyridine skeletons, such as r(piq)2(acac)] In addition, 2,3,7,8,12,13,17,18-octaethyl-21H,23H-pol Platinum complexes such as phyrinplatinum(II) (abbreviated as PtOEP) and tris(1,3-difluorophenyl) (phenyl-1,3-propanedionato)(monophenanthroline)europium(III) (abbreviation: [Eu(DBM)3(Phen)]), tris[1-(2-thenoyl)-3,3 ,3-trifluoroacetonato](monophenanthroline)europium(III)(abbreviation These include rare earth metal complexes such as [Eu(TTA)3(Phen)]. is a compound that exhibits red phosphorescence, with an emission peak between 600 nm and 700 nm. In addition, organometallic iridium complexes with a pyrazine skeleton emit red light with good chromaticity. Obtained.

[0069] In addition to the phosphorescent compounds described above, known phosphorescent light-emitting materials may be selected and used. stomach.

[0070] TADF materials include fullerene and its derivatives, acridine and its derivatives, and eosin. Derivatives of magnesium (Mg), zinc (Zn), cadmium, etc. can also be used. (Cd), tin (Sn), platinum (Pt), indium (In), or palladium (P d) and the like. Examples of the metal-containing porphyrin include: For example, the protoporphyrin-tin fluoride complex (SnF2(Pro to IX), mesoporphyrin-tin fluoride complex (SnF2(Meso IX)), Hematoporphyrin-tin fluoride complex (SnF2(Hemato IX)), Copropor Phyllin tetramethyl ester-tin fluoride complex (SnF2(Copro III-4M e)), octaethylporphyrin-tin fluoride complex (SnF2(OEP)), ethiop Porphyrin-tin fluoride complex (SnF2(Etio I)), octaethylporphyrin -platinum chloride complex (PtCl2OEP) and the like.

[0071] [ka]

[0072] In addition, 2-(biphenyl-4-yl)-4,6-bis(12-phenyl)-4-phenyl-4-methyl-4-phenyl ... (phenylindolo[2,3-a]carbazol-11-yl)-1,3,5-triazine ( Abbreviation: PIC-TRZ) and 9-(4,6-diphenyl-1,3,5-triazine-2- yl)-9'-phenyl-9H,9'H-3,3'-bicarbazole (abbreviation: PCCzT zn), 9-[4-(4,6-diphenyl-1,3,5-triazin-2-yl)phenyl phenyl]-9'-phenyl-9H,9'H-3,3'-bicarbazole (abbreviation: PCCzPT zn), 2-[4-(10H-phenoxazin-10-yl)phenyl]-4,6-difluoro Phenyl-1,3,5-triazine (abbreviation: PXZ-TRZ), 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-azabicyclo[4.2.1.2]phenyl) cridin-10-yl)-9H-xanthen-9-one (abbreviation: ACRXTN), bis[ 4-(9,9-dimethyl-9,10-dihydroacridine)phenyl]sulfone (abbreviation: DMAC-DPS), 10-phenyl-10H,10'H-spiro[acridine-9,9 π-electron-rich heteroaromatic rings such as '-anthracene]-10'-one (abbreviation: ACRSA) and a heterocyclic compound having one or both of a π-electron-deficient heteroaromatic ring can also be used. Since the heterocyclic compound has a π-electron rich heteroaromatic ring and a π-electron deficient heteroaromatic ring, Among them, those having a π-electron-deficient heteroaromatic ring are preferred because they have high electron transporting properties and hole transporting properties. Among the skeletons that have pyridine skeleton, diazine skeleton (pyrimidine skeleton, pyrazine skeleton, pyridine skeleton, The tetraazine skeleton and the triazine skeleton are preferred because they are stable and reliable. Benzofuropyrimidine skeleton, benzothienopyrimidine skeleton, benzofuropyrazine skeleton, The zothienopyrazine skeleton is preferred because it has high acceptor properties and good reliability. Among the skeletons with electron-rich heteroaromatic rings, acridine skeleton, phenoxazine skeleton, fluorine skeleton, The ethenothiazine skeleton, furan skeleton, thiophene skeleton, and pyrrole skeleton are stable and reliable. It is preferable that the furan skeleton has at least one of the above skeletons. The dibenzofuran skeleton is used for the thiophene skeleton, and the dibenzothiophene skeleton is used for the thiophene skeleton. The pyrrole skeleton is preferably an indole skeleton, a carbazole skeleton, an indole skeleton, or an indole skeleton. Carbazole skeleton, bicarbazole skeleton, 3-(9-phenyl-9H-carbazole-3 A π-electron-rich heteroaromatic ring and a π-(9H-yl)-9H-carbazole skeleton are particularly preferred. The electron-deficient heteroaromatic ring directly bonded to the π-electron-rich heteroaromatic ring has electron-donating properties. The electron-accepting properties of the π-electron-deficient heteroaromatic rings are both strong, and the energies of the S1 and T1 levels are This is particularly preferred because the difference is small and thermally activated delayed fluorescence can be obtained efficiently. Instead of a π-electron-deficient heteroaromatic ring, an aromatic ring bonded with an electron-withdrawing group such as a cyano group is used. In addition, as the π-electron-rich skeleton, an aromatic amine skeleton, a phenazine skeleton, etc. may be used. In addition, as the π-electron deficient skeleton, a xanthene skeleton, a thioxanthene skeleton, Dioxide skeleton, oxadiazole skeleton, triazole skeleton, imidazole skeleton, ammonium The tetraquinone skeleton, boron-containing skeletons such as phenylborane and boranthrene, benzonitrile, The aromatic ring or heteroaromatic ring having a nitrile group or a cyano group, such as cyanobenzene, Carbonyl skeletons such as phenones, phosphine oxide skeletons, sulfone skeletons, etc. can be used. In this way, at least one of a π-electron deficient heteroaromatic ring and a π-electron rich heteroaromatic ring can be obtained. In place of one another, π-electron deficient and π-electron rich backbones can be used.

[0073] [ka]

[0074] TADF materials have a small difference between the S1 and T1 levels, and triple intersystem crossing occurs due to reverse intersystem crossing. The function of converting energy from first excitation energy to singlet excitation energy Therefore, the triplet excitation energy can be converted to a single state by a small amount of thermal energy. It is possible to upconvert to doublet excited energy (reverse intersystem crossing), and efficiently convert the singlet excited state It is possible to generate triplet excitation energy and convert it into luminescence. .

[0075] In addition, exciplexes (exciplexes) that form excited states with two types of substances The difference between the S1 and T1 levels is extremely small, As a TADF material capable of converting triplet excitation energy into singlet excitation energy, It has all the functions.

[0076] As an index of the T1 level, the phosphorescence observed at low temperatures (for example, from 77 K to 10 K) As for TADF materials, the fluorescent spectrum is at the short wavelength end. Draw a tangent line at the wavelength of the extrapolated line and define the energy of the wavelength as the S1 level. When a tangent line is drawn at the base of the short wavelength side and the energy of the wavelength of the extrapolated line is taken as the T1 level, The difference between S1 and T1 is preferably 0.3 eV or less, and more preferably 0.2 eV or less. It is more preferable that:

[0077] In addition, when a TADF material is used as the luminescent center material, the S1 level of the host material is It is preferable that the T1 level of the host material is higher than the T1 level of the TADF material. A level higher than 1 is preferred.

[0078] The host material of the light-emitting layer may be a material having an electron transporting property or a material having a hole transporting property, Various carrier transport materials can be used, such as TADF materials.

[0079] As a material having a hole transporting property that can be used as a host material, there are materials having an amine skeleton or a π Organic compounds having an electron-rich heteroaromatic ring skeleton are preferred. For example, 4,4'-bis[N -(1-naphthyl)-N-phenylamino]biphenyl (abbreviation: NPB), N,N'-biphenyl (3-methylphenyl)-N,N'-diphenyl-[1,1'-biphenyl]-4,4 '-diamine (abbreviation: TPD), 4,4'-bis[N-(spiro-9,9'-bifluorene 4-phenyl- 4'-(9-phenylfluoren-9-yl)triphenylamine (abbreviation: BPAFLP) ), 4-phenyl-3'-(9-phenylfluoren-9-yl)triphenylamine ( abbreviation: mBPAFLP), 4-phenyl-4'-(9-phenyl-9H-carbazole- 3-yl)triphenylamine (abbreviation: PCBA1BP), 4,4'-diphenyl-4' '-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PC BBi1BP), 4-(1-naphthyl)-4'-(9-phenyl-9H-carbazole- 3-yl)triphenylamine (abbreviation: PCBANB), 4,4'-di(1-naphthyl) -4''-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation : PCBNBB), 9,9-dimethyl-N-phenyl-N-[4-(9-phenyl-9H -carbazol-3-yl)phenyl]fluoren-2-amine (abbreviation: PCBAF), N-phenyl-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl] Aromatic amines such as spiro-9,9'-bifluorene-2-amine (abbreviation: PCBASF) Compounds with a benzene skeleton and 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), 3,3'- Carbazole skeleton such as bis(9-phenyl-9H-carbazole) (abbreviation: PCCP) and compounds having 4,4',4''-(benzene-1,3,5-triyl)tri(dibenzyl) benzothiophene) (abbreviation: DBT3P-II), 2,8-diphenyl-4-[4-(9- (phenyl-9H-fluoren-9-yl)phenyl]dibenzothiophene (abbreviation: DBT FLP-III), 4-[4-(9-phenyl-9H-fluoren-9-yl)phenyl ]-6-phenyldibenzothiophene (abbreviated as DBTFLP-IV) and other thiophene skeletons Compounds with 4,4',4''-(benzene-1,3,5-triyl)tri(diphenyl) benzofuran) (abbreviation: DBF3P-II), 4-{3-[3-(9-phenyl-9H- Fluoren-9-yl)phenyl]phenyl}dibenzofuran (abbreviation: mmDBFFLB Among the above, aromatic amino compounds such as i-II) and furan compounds are preferred. Compounds having an amine skeleton and compounds having a carbazole skeleton have good reliability. It is preferable because it has high hole transport properties and contributes to reducing the driving voltage. The hole transport materials given as examples of organic compounds having hole transport properties can also be used. Cut.

[0080] Examples of materials having electron transport properties that can be used as a host material include bis( 10-hydroxybenzo[h]quinolinato)beryllium(II) (abbreviation: BeBq2), Bis(2-methyl-8-quinolinolato)(4-phenylphenolato)aluminum(II) I) (abbreviation: BAlq), bis(8-quinolinolato)zinc(II) (abbreviation: Znq), Bis[2-(2-benzoxazolyl)phenolato]zinc(II) (abbreviation: ZnPBO), Bis[2-(2-benzothiazolyl)phenolato]zinc(II) (abbreviation: ZnBTZ) Metal complexes and organic compounds having a π-electron deficient heteroaromatic ring skeleton are preferred. Examples of organic compounds having a toe-shaped 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-butyl) 1,3,4-oxadiazol-2-yl)benzene (abbreviation: OXD- 7), 9-[4-(5-phenyl-1,3,4-oxadiazol-2-yl)phenyl ]-9H-carbazole (abbreviation: CO11), 2,2',2''-(1,3,5-benzene (1-phenyl-1H-benzimidazole) (TPBI), 2-[3-(dibenzothiophen-4-yl)phenyl]-1-phenyl-1H-benzo Heterocyclization of polyazole skeletons such as imidazole (abbreviation: mDBTBIm-II) compounds and 2-[3-(dibenzothiophen-4-yl)phenyl]dibenzo[f,h]ky Noxaline (abbreviation: 2mDBTPDBq-II), 2-[3'-(dibenzothiophene- 4-yl)biphenyl-3-yl]dibenzo[f,h]quinoxaline (abbreviation: 2mDBT BPDBq-II), 2-[3'-(9H-carbazol-9-yl)biphenyl-3- yl]dibenzo[f,h]quinoxaline (abbreviation: 2mCzBPDBq), 4,6-bis[ 3-(phenanthrene-9-yl)phenyl]pyrimidine (abbreviation: 4,6mPnP2Pm ), 4,6-bis[3-(4-dibenzothienyl)phenyl]pyrimidine (abbreviation: 4,6 Heterocyclic compounds with diazine skeletons such as mDBTP2Pm-II) and 3,5-bis[ 3-(9H-carbazol-9-yl)phenyl]pyridine (abbreviation: 35DCzPPy) , 1,3,5-tri[3-(3-pyridyl)phenyl]benzene (abbreviation: TmPyPB) Among the above, heterocyclic compounds having a pyridine skeleton, such as Heterocyclic compounds having a pyridine skeleton and heterocyclic compounds having a pyridine skeleton are preferred because of their high reliability. In particular, heterocyclic compounds with a diazine (pyrimidine or pyrazine) skeleton have electron transport properties. This has high performance and also contributes to reducing the driving voltage.

[0081] The TADF materials that can be used as host materials are listed above as TADF materials. When a TADF material is used as a host material, the TA The triplet excitation energy generated in the DF material is converted to singlet excitation energy by reverse intersystem crossing. The energy is then transferred to the luminescent center, increasing the luminous efficiency of the light-emitting device. In this case, the TADF material acts as an energy donor and emits light. The central substance acts as an energy acceptor.

[0082] This is extremely effective when the luminescent center substance is a fluorescent substance. In order to obtain high luminous efficiency, the S1 level of the TADF material must be higher than the S1 level of the fluorescent material. The T1 level of the TADF material is preferably higher than the S1 level of the fluorescent material. Therefore, the T1 level of the TADF material is preferably higher than the T1 level of the fluorescent material. It is preferable that the level is higher.

[0083] In addition, T that exhibits emission that overlaps with the wavelength of the lowest energy absorption band of the fluorescent substance It is preferable to use an ADF material, which allows the TADF material to be converted into a fluorescent material. This is preferable because the transfer of excitation energy becomes smooth and light emission can be obtained efficiently.

[0084] In addition, singlet excitation energy is efficiently generated from triplet excitation energy by reverse intersystem crossing. For this to occur, it is preferable that carrier recombination occurs in the TADF material. The triplet excitation energy generated in the DF material is transferred to the triplet excitation energy of the fluorescent material. For this purpose, it is preferable that the fluorescent substance has a luminophore ( It is preferable that the compound has a protecting group around the π bond (the skeleton that causes light emission). A substituent having no carbon atoms is preferred, and a saturated hydrocarbon is preferred, specifically a hydrocarbon having 3 to 10 carbon atoms. The alkyl groups listed below, substituted or unsubstituted cycloalkyl groups with 3 to 10 carbon atoms, A trialkylsilyl group having 3 to 10 protecting groups is preferred, and a group having a plurality of protecting groups is more preferred. Substituents without π bonds have poor carrier transport function, and therefore, The distance between the TADF material and the luminophores of the fluorescent material can be reduced without significantly affecting carrier recombination. Here, the luminophore is the molecule that causes light emission in a fluorescent substance. The luminophore preferably has a skeleton with a π bond and contains an aromatic ring. Preferably, the aromatic ring has a condensed aromatic ring or a condensed heteroaromatic ring. Examples of the heteroaromatic ring include a phenanthrene skeleton, a stilbene skeleton, an acridone skeleton, and a phenanthren skeleton. Examples of the hydroxyazine skeleton include naphthalene skeleton and anthracene skeleton. skeleton, fluorene skeleton, chrysene skeleton, triphenylene skeleton, tetracene skeleton, pyrene skeleton perylene skeleton, coumarin skeleton, quinacridone skeleton, naphthobisbenzofuran skeleton Fluorescent materials that emit light with high fluorescence quantum yields are preferred.

[0085] When a fluorescent substance is used as the luminescent center substance, the host material is preferably a compound having an anthracene skeleton. A material having an anthracene skeleton is preferably used as a host material for a fluorescent material. When used as a phosphor, it is possible to realize a light-emitting layer having good luminous efficiency and durability. As a material having an anthracene skeleton, a diphenylanthracene skeleton is used. In particular, substances with a 9,10-diphenylanthracene skeleton are chemically stable. In addition, when the host material has a carbazole skeleton, the hole injection / transport property is high. However, a benzocarbazole skeleton in which a benzene ring is further condensed to a carbazole is preferred. When it contains a saccharin, the HOMO is shallower than that of carbazole by about 0.1 eV, making it easier for holes to enter. In particular, when the host material contains a dibenzocarbazole skeleton, The HOMO is about 0.1 eV shallower than that of rubazole, making it easier for holes to enter. It is also suitable because it has excellent transportability and high heat resistance. Among these, 9,10-diphenylanthracene skeleton and carbazole skeleton (and It is a substance that simultaneously has a benzocarbazole skeleton or a dibenzocarbazole skeleton. From the viewpoint of the hole injection and transport properties, a benzofluorene skeleton was used instead of a carbazole skeleton. A fluorene skeleton or a dibenzofluorene skeleton may also be used. Examples of such substances include 9-fluorene, Phenyl-3-[4-(10-phenyl-9-anthryl)phenyl]-9H-carbazo PCzPA, 3-[4-(1-naphthyl)-phenyl]-9-phenyl-9 H-Carbazole (abbreviation: PCPN), 9-[4-(10-phenyl-9-anthracene 7-[4-(10-phenyl)phenyl]-9H-carbazole (abbreviation: CzPA), -9-anthryl)phenyl]-7H-dibenzo[c,g]carbazole (abbreviation: cgD BCzPA), 6-[3-(9,10-diphenyl-2-anthryl)phenyl]-benzophenone Zo[b]naphtho[1,2-d]furan (abbreviation: 2mBnfPPA), 9-phenyl-10 -{4-(9-phenyl-9H-fluoren-9-yl)biphenyl-4'-yl}an Thracene (abbreviation: FLPPA), 9-(1-naphthyl)-10-[4-(2-naphthyl) phenyl]anthracene (abbreviation: BH513), etc. In particular, CzPA, cgD BCzPA, 2mBnfPPA, and PCzPA are the preferred choices because they show very good properties. It is a choice.

[0086] The host material may be a mixture of a plurality of substances. When used, a material having an electron transporting property and a material having a hole transporting property may be mixed. It is preferable to mix a material having an electron transport property with a material having a hole transport property. Therefore, the transport property of the light-emitting layer 113 can be easily adjusted, and the recombination region can be easily controlled. The weight ratio of the content of the material having hole transport properties to the content of the material having electron transport properties is The ratio of the material having hole transport properties to the material having electron transport properties may be 1:19 to 19:1.

[0087] A phosphorescent material can be used as part of the mixed material. When a fluorescent substance is used as the luminescent center material, the luminescent substance is It can be used as an energy donor that provides

[0088] Furthermore, these mixed materials may form an exciplex. The exciplex is formed to emit light that overlaps with the wavelength of the lowest energy absorption band of By selecting such a combination, energy transfer becomes smooth and light emission can be obtained efficiently. In addition, the use of this configuration is also preferable because the driving voltage is reduced.

[0089] At least one of the materials forming the exciplex may be a phosphorescent material. By doing so, triplet excitation energy is efficiently converted to singlet excitation energy by reverse intersystem crossing. can be converted to

[0090] As a combination of materials that efficiently form exciplexes, HO It is preferable that the MO level is equal to or higher than the HOMO level of the material having electron transport properties. When the LUMO level of the material having electron transport properties is higher than the LUMO level of the material having electron transport properties, It is preferable that the LUMO level and the HOMO level of the material are determined by cyclic voltammetry. From the electrochemical properties (reduction potential and oxidation potential) of the material measured by CV measurement It can be derived.

[0091] The formation of an exciplex is determined by, for example, the emission spectrum of a material having hole transport properties, the emission spectrum of a material having electron transport properties, The emission spectrum of the material having the above structure and the emission spectrum of the mixed film of these materials are shown in Fig. In comparison, the emission spectrum of the mixed film is shifted to longer wavelengths than the emission spectra of each material ( This can be confirmed by observing the phenomenon of a new peak on the long wavelength side. Alternatively, transient photoluminescence (PL) of materials with hole transport properties and electron transport properties can be observed. The transient PL of the materials with the same properties and the transient PL of the mixed film of these materials were compared. The transient PL lifetime of the film has a longer-lived component than the transient PL lifetime of each material, or a delayed component. This can be confirmed by observing the difference in transient response, such as the percentage of In addition, the above-mentioned transient PL may be read as transient electroluminescence (EL). That is, the transient EL of a material with hole transport properties and the transient E of a material with electron transport properties are By comparing the transient EL of the L and the mixed films and observing the difference in the transient response, The formation of exciplexes can be confirmed.

[0092] The light-emitting device of one embodiment of the present invention having the above structure is a highly reliable light-emitting device. In particular, the slope of the degradation curve is small, and long-term degradation is suppressed. It can be used as a service.

[0093] Next, other layers that can be used for the EL layer 103 will be described.

[0094] The hole injection layer 111 is a layer for facilitating the injection of holes into the EL layer 103. The hole injection layer 111 is made of a material with high acceptor properties. However, the organic compound containing the acceptor material and the hole transporting material may be used. It is preferably made of a composite material.

[0095] The acceptor substance is an organic compound with hole transport properties contained in the hole transport layer or hole injection layer. It is a substance that exhibits electron accepting properties.

[0096] As the acceptor substance, both inorganic and organic compounds can be used. However, organic compounds with electron-withdrawing groups (especially halogen groups such as fluoro groups and cyano groups) It is preferable to use the following as the acceptor substance. a substance that exhibits electron accepting properties with respect to an organic compound having hole transport properties contained in the hole injection layer or the hole injection layer; can be selected appropriately.

[0097] Such an acceptor substance is, for example, 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-hexaazatrif Phenylene (abbreviation: HAT-CN), 1,3,4,5,7,8-hexafluorotetraphenyl Nonaphthoquinodimethane (abbreviation: F6-TCNNQ), 2-(7-dicyanomethylene-1 ,3,4,5,6,8,9,10-Octafluoro-7H-pyren-2-ylidene)malon In particular, compounds having multiple heteroatoms such as HAT-CN are Compounds in which an electron-withdrawing group is bonded to a condensed aromatic ring are preferred because they are thermally stable. [3]Radialene derivatives containing electron-withdrawing groups (especially halogen groups such as fluoro groups and cyano groups) Conductors are preferred because they have very high electron-accepting properties, specifically α,α',α''-1,2, 3-Cyclopropanetriylidenetris[4-cyano-2,3,5,6-tetrafluoro Benzeneacetonitrile], α,α',α''-1,2,3-cyclopropanetriylidene Tris[2,6-dichloro-3,5-difluoro-4-(trifluoromethyl)benzene acetonitrile], α,α',α''-1,2,3-cyclopropanetriylidenetri Organic compounds such as acetonitrile [2,3,4,5,6-pentafluorobenzene] When the acceptor substance is an inorganic compound, a transition metal oxide is used. In particular, oxides of metals belonging to groups 4 to 8 of the periodic table are preferred. The oxides of metals belonging to groups 4 to 8 in the periodic table are Vanadium oxide, niobium oxide, tantalum oxide, chromium oxide, molybdenum oxide, tungste Among these, manganese oxide, rhenium oxide, etc. are preferred due to their high electron-accepting properties. Ribden is preferred because it is stable in the air, has low hygroscopicity, and is easy to handle.

[0098] The organic compound with hole transport properties used in the composite material is a hole transport material, and its HO The MO level has a relatively deep HOMO level of -5.7 eV or more and -5.4 eV or less. It is preferable that the organic compound having hole transport properties used in the composite material has a relatively deep HOMO By having the structure, the induction of holes is moderately suppressed, but on the other hand, the induced holes This facilitates injection into the hole transport layer 112.

[0099] Organic compounds with hole transport properties that can be used in composite materials include those with carbazole skeletons, dibenzofuran skeletons, and It has either a benzofuran skeleton, a dibenzothiophene skeleton, or an anthracene skeleton. In particular, a substituted benzofuran ring or a substituted benzothiophene ring is preferred. Aromatic amines having a 9-membered group, aromatic monoamines having a naphthalene ring, or - an aromatic monoamine in which the fluorenyl group is attached to the amine nitrogen through an arylene group In addition, these substances may have an N,N-bis(4-biphenyl)amino group. The above material is preferable because it allows the production of a light-emitting device with a long life. Specific examples of such substances include N-(4-biphenyl)-6,N-diphenylbenzoxazole. [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 BBABnf, 4,4'-bis(6-phenylbenzo[b]naphtho[1,2 -d]furan-8-yl)-4''-phenyltriphenylamine (abbreviation: BnfBB1 BP), 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 (BB ABnf(II)(4)), N,N-bis[4-(dibenzofuran-4-yl)phenyl ]-4-amino-p-terphenyl (abbreviation: DBfBB1TP), N-[4-(dibenzo Thiophen-4-yl)phenyl]-N-phenyl-4-biphenylamine (abbreviation: Th BA1BP), 4-(2-naphthyl)-4',4''-diphenyltriphenylamine ( Abbreviation: BBAβNB), 4-[4-(2-naphthyl)phenyl]-4',4''-diphenyl Nyltriphenylamine (abbreviation: BBAβNBi), 4,4'-diphenyl-4''-( 6;1'-Binaphthyl-2-yl)triphenylamine (abbreviation: BBAαNβNB), 4 ,4'-Diphenyl-4''-(7;1'-binaphthyl-2-yl)triphenylamine (Abbreviation: BBAαNβNB-03), 4,4'-diphenyl-4''-(7-phenyl) Naphthyl-2-yltriphenylamine (abbreviation: BBAPβNB-03), 4,4'-di Phenyl-4''-(6;2'-binaphthyl-2-yl)triphenylamine (abbreviation: B BA(βN2)B), 4,4'-diphenyl-4''-(7;2'-binaphthyl-2-isothiazolinone (βN2)B-03), 4,4'-diphenyl- 4''-(4;2'-binaphthyl-1-yl)triphenylamine (abbreviation: BBAβNα NB), 4,4'-diphenyl-4''-(5;2'-binaphthyl-1-yl)triphenyl Nylamine (abbreviation: BBAβNαNB-02), 4-(4-biphenylyl)-4'-(2 -naphthyl)-4''-phenyltriphenylamine (abbreviation: TPBiAβNB), 4- (3-biphenylyl)-4'-[4-(2-naphthyl)phenyl]-4''-phenyl Biphenylamine (abbreviation: mTPBiAβNBi), 4-(4-biphenylyl)-4'- [4-(2-naphthyl)phenyl]-4''-phenyltriphenylamine (TP BiAβNBi), 4-phenyl-4'-(1-naphthyl)triphenylamine (abbreviation: αNBA1BP), 4,4'-bis(1-naphthyl)triphenylamine (abbreviation: αNB B1BP), 4,4'-diphenyl-4''-[4'-(carbazol-9-yl)biphenyl] phenyl-4-yl]triphenylamine (abbreviation: YGTBi1BP), 4'-[4-(3 -phenyl-9H-carbazol-9-yl)phenyl]tris(1,1'-biphenyl) -4-yl)amine (abbreviation: YGTBi1BP-02), 4-diphenyl-4'-(2- Naphthyl-4''-{9-(4-biphenylyl)carbazole}triphenylamine (Abbreviation: YGTBiβNB), N-[4-(9-phenyl-9H-carbazole-3-yl) -N-[4-(1-naphthyl)phenyl]-9,9'-spirobi(9H- N,N-bis(4-biphenylyl)fluorene-2-amine (abbreviation: PCBNBSF) )-9,9'-spirobi[9H-fluorene]-2-amine (abbreviation: BBASF), N, N-bis(1,1'-biphenyl-4-yl)-9,9'-spirobi[9H-fluorene ]-4-amine (abbreviation: BBASF(4)), N-(1,1'-biphenyl-2-yl) -N-(9,9-dimethyl-9H-fluoren-2-yl)-9,9'-spirobi(9H -fluorene)-4-amine (abbreviation: oFBiSF), N-(4-biphenyl)-N-( Dibenzofuran-4-yl)-9,9-dimethyl-9H-fluoren-2-amine (abbreviation :FrBiF), N-[4-(1-naphthyl)phenyl]-N-[3-(6-phenyldiphenyl) Benzofuran-4-yl)phenyl]-1-naphthylamine (abbreviation: mPDBfBNBN ), 4-phenyl-4'-(9-phenylfluoren-9-yl)triphenylamine ( Abbreviation: BPAFLP), 4-phenyl-3'-(9-phenylfluoren-9-yl)trimethylsilyl mBPAFLP, 4-phenyl-4'-[4-(9-phenyl (Difluoroen-9-yl)phenyl]triphenylamine (abbreviation: BPAFLBi), 4 -phenyl-4'-(9-phenyl-9H-carbazol-3-yl)triphenylamine 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 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]spiro- 9,9'-Bifluorene-2-amine (abbreviation: PCBASF), N-(1,1'-biphenyl) N-[4-(9-phenyl-9H-carbazole]-4-yl)-9,9-dimethyl-N-[4-(9-phenyl-9H-carbazole] -3-yl)phenyl]-9H-fluoren-2-amine (abbreviation: PCBBiF), etc. It can be done.

[0100] In addition, organic compounds with hole transport properties have hole mobility that is proportional to the square of the electric field strength [V / cm]. If the root is 600, then 1 x 10 -3 cm 2 It is preferable that the value is equal to or less than / Vs.

[0101] The composition of the organic compound having acceptor and hole transport properties in the composite material is 1:0.0 The weight ratio is preferably 1 to 1:0.15. 1 to 1:0.1 (weight ratio).

[0102] The hole injection layer 111 is made of the composite material described above, and an organic compound having hole transport properties is When an organic compound with a HOMO level of -5.7 eV or more and -5.4 eV or less is used, electron transport The second skeleton of the electron transport material in the transport layer 114 is a fused aromatic carbon having two to four rings. A hydrogen ring can be used.

[0103] In this case, the electron mobility of the electron transport layer 114 is such that the square root of the electric field strength [V / cm] is 6. 1 x 10 if 00 -7 cm 2 / Vs or more 5×10 -5 cm 2 / Vs or less It is preferable that:

[0104] Furthermore, in this case, the electron transport layer 114 contains a metal, a metal salt, a metal oxide, or an organic metal salt. Preferably, the metal, metal salt, metal oxide, or organic metal salt is an alkali metal or It is preferable that the metal complex is a metal complex having an alkaline earth metal. It is preferred to have a ligand having nitrogen and oxygen, and the ligand is 8-hydroxyquino Among such metal complexes, it is more preferable that they contain a monovalent metal ion. The complex of the formula (I) is preferred, and specifically, for example, 8-hydroxyquinolinato-lithium (abbreviation: L iq), 8-hydroxyquinolinato-sodium (abbreviation: Naq), etc. In particular, lithium complexes are preferred, and Liq is more preferred. If the compound contains a methyl group, its methyl group (e.g., 2-methyl group or 5-methyl group) Body) can also be used.

[0105] As described above, the electron transport layer 114 contains a metal, a metal salt, a metal oxide, or an organic metal salt and an electron When used together with a hole transport material, the metal, metal salt, metal oxide, or organometallic salt transports the holes. To assist the receiving function, a condensed ring structure of 2 to 4 rings is used as the second skeleton of the electron transport material. Aromatic hydrocarbon rings can be preferably used. Preferred structures for fused aromatic hydrocarbon rings As described above, examples of the fused aromatic hydrocarbon ring having 2 to 4 rings include , naphthalene ring, fluorene ring, anthracene ring, phenanthrene ring, tetracene ring, Examples of the second skeleton include a ricene ring, a triphenylene ring, and a pyrene ring. The aromatic ring is preferably a condensed aromatic ring having 3 to 4 rings, more preferably an anthracene ring. do.

[0106] The metal, metal salt, metal oxide, or organic metal salt in the electron transport layer 114 is: It is preferable that a concentration difference (including the case where the concentration is 0) exists in the thickness direction. This makes it possible to provide a light emitting device with even better life and reliability.

[0107] The electron transport material used in the electron transport layer 114 has a HOMO level of −6.0 eV. It is preferable that this is equal to or greater than this.

[0108] In a light-emitting device having such a configuration, a driving test under a constant current density condition In the case where the brightness deterioration curve obtained by the above process shows a shape with a maximum value, that is, when the brightness deterioration curve shows a shape with a maximum value, the deterioration The shape may have areas where the brightness increases over time. The light-emitting device shown in Fig. 1 shows the initial degradation, which is a rapid deterioration at the initial stage of operation, and the brightness increase This allows the initial deterioration to be reduced and the device has a very good operating life. This type of light-emitting device is called Recombi. ReSTI element shall be referred to as the child.

[0109] This is because the hole injection layer having the above-mentioned structure uses a hole transport material with a deep HOMO level. Therefore, the induced holes are easily injected into the hole transport layer and the light emitting layer. Therefore, in the initial stage of operation, only a small number of holes pass through the light-emitting layer and reach the electron transport layer. It is easy to achieve this state.

[0110] Here, the electron transport material and the alkali metal or alkaline earth metal element, compound, or complex In a light-emitting device having an electron transport layer containing On the other hand, as mentioned above, the hole injection layer Since the induction of holes is moderately suppressed, many holes can be supplied to the electron transport layer. As a result, the number of holes that can reach the electron transport layer decreases over time, and the holes are transported to the light-emitting layer. In other words, during continuous lighting, recombination occurs more frequently in the light-emitting layer. This shift in the carrier balance makes it easier for degradation to occur. A light-emitting device in which initial deterioration is suppressed, the light-emitting device having a portion in which the luminance increases over time. You can get the service.

[0111] The light-emitting device according to one embodiment of the present invention having the above structure has an extremely long lifetime. In particular, in the region where deterioration is extremely small up to about LT95, Furthermore, as an electron transport material, a first skeleton having a function of accepting holes, a second skeleton having a function of accepting holes, and a monocyclic and π-electron-deficient Light emission according to one embodiment of the present invention using a compound having a third skeleton that is a foot-shaped heteroaromatic ring The device is a light-emitting device with very little long-term degradation and a long life. It can be used as a chair.

[0112] In addition, by suppressing initial deterioration, one of the major weaknesses of organic EL devices can be The problem of image sticking is still being debated, and the aging process before shipping is being carried out to reduce it. The time can also be significantly reduced.

[0113] The hole transport layer 112 may be a single layer (FIG. 1(A)), but the first hole transport layer 112- It is preferable that the layer has a first hole transport layer 112-1 and a second hole transport layer 112-2 (FIG. 1(B)). The layer may have a plurality of hole transport layers.

[0114] The hole transport layer 112 can be formed using a hole transport material. The hole transport material used in 2 is a hole transport material that can be used as the host material described above. Alternatively, an organic compound having hole transport properties that can be used as a composite material can be used. Cut.

[0115] When the hole transport layer 112 is formed as a plurality of layers, the hole transport layers constituting the adjacent hole transport layers The HOMO level of the hole transport material is deeper in the material used for the hole transport layer closer to the light emitting layer 113. It is preferable that the difference is within 0.2 eV.

[0116] In addition, when the hole injection layer 111 is formed of a composite material, the hole injection layer 111 is The HOMO level of the hole transport material used in the hole transport layer 112 is It is preferable that the depth is deeper than that of the organic compound having transport properties, and the difference is within 0.2 eV. It's nice.

[0117] The above relationship of the HOMO levels allows holes to be smoothly injected into each layer. This can prevent an increase in driving voltage and a shortage of holes in the light-emitting layer.

[0118] The hole transport material used in the hole transport layer 112 has a backbone having a function of transporting holes. As the skeleton having the function of transporting holes, organic compounds The HOMO level of the carbazole skeleton, dibenzofuran skeleton, and dibenzothiazolinone is not too shallow. The benzophenone skeleton and the anthracene skeleton are preferred, and the dibenzofuran skeleton is particularly preferred. In addition, between adjacent layers in the hole injection layer 111 and the plurality of hole transport layers 112, It is preferable that these skeletons are common because this allows for smooth hole injection. The same hole is transported between adjacent layers in the injection layer 111 and the plurality of hole transport layers 112. The use of transport materials is preferred for the same reasons.

[0119] When a plurality of hole transport layers are stacked, the first hole transport layer 112-1 is The second hole transport layer 112-2 is located closer to the anode 101 than the second hole transport layer 112-2. In some cases, it also functions as an electron blocking layer.

[0120] The light-emitting device according to one embodiment of the present invention having the above-described structure has an extremely long lifetime. It can be a vise.

[0121] (Embodiment 2) Next, examples of the detailed structure and materials of the light-emitting device will be described. The device has an EL layer 103 made up of multiple layers between a pair of electrodes, an anode 101 and a cathode 102, The EL layer 103 is formed by at least the light-emitting layer 113 and the electron transport layer 114 from the anode 101 side. The EL layer 103 includes a hole injection layer, a hole transport layer, and a Various layers such as transport layer, electron injection layer, carrier blocking layer, exciton blocking layer, charge generation layer, etc. The structure can be applied.

[0122] The anode 101 is made of a metal, alloy, or conductive compound having a large work function (specifically, 4.0 eV or more). It is preferable to form the film using a material such as a material containing fluorine, a compound ... Indium tin oxide (ITO), silicon or Indium oxide-tin oxide, indium oxide-zinc oxide, oxide containing silicon oxide Examples include indium oxide containing tungsten and zinc oxide (IWZO). These conductive metal oxide films are usually formed by sputtering, but they can also be formed by methods such as sol-gel deposition. As an example of the manufacturing method, indium oxide-zinc oxide Sputtering was performed using a target containing 1 to 20 wt% zinc oxide added to indium oxide. Also, there are methods for forming the film by the ring method. Indium oxide (IWZO) is a material that is made by mixing tungsten oxide with indium oxide at a ratio of 0.5 to 5. % by weight and zinc oxide 0.1-1 wt% by sputtering. Other materials include gold (Au), platinum (Pt), nickel (Ni), and titanium. W, chromium (Cr), molybdenum (Mo), iron (Fe), cobalt (Co) , copper (Cu), palladium (Pd), or nitrides of metallic materials (e.g., titanium nitride), etc. Graphene can also be used. Representative materials for forming the electrode have been listed above. In one embodiment of the present invention, 11, an organic compound having hole transport properties and a substance showing electron accepting properties to the organic compound Since a composite material containing the above is used, the electrode material can be selected regardless of the work function.

[0123] In this embodiment, the stacked structure of the EL layer 103 is as shown in FIG. Injection layer 111, hole transport layer 112 (first hole transport layer 112-1, second hole transport layer 11 2-2), the light-emitting layer 113, the electron transport layer 114 (first electron transport layer 114-1, second electron The structure having the electron injection layer 115 in addition to the transport layer 114-2 will be described. The materials used are specifically shown below.

[0124] The hole injection layer 111, the hole transport layer 112 (the first hole transport layer 112-1, the second hole transport layer 112-2), the light-emitting layer 113 and the electron transport layer 114 (first electron transport layer 114-1, second electron transport layer 114-2). The electron transport layer 114-2) of the second embodiment has been described in detail in the first embodiment, so it will not be repeated here. The description is omitted. Please refer to the description in the first embodiment.

[0125] Between the electron transport layer 114 and the cathode 102, an electron injection layer 115 made of lithium fluoride ( Alkalis such as LiF, cesium fluoride (CsF), calcium fluoride (CaF2), etc. Alternatively, a layer containing an alkali metal or an alkaline earth metal or a compound thereof may be provided. 15 is a layer made of a substance having electron transport properties, in which an alkali metal or alkaline earth metal or A material containing such a compound or an electride may also be used. For example, a substance in which electrons are highly added to a mixed oxide of calcium and aluminum is used. Examples include:

[0126] In addition, a charge generating layer is provided between the electron transport layer 114 and the cathode 102 instead of the electron injection layer 115. The charge generating layer may be provided with a positive potential on the layer in contact with the cathode side of the charge generating layer. The charge generating layer is a layer that can inject electrons into the layer that is in contact with the anode side. The P-type layer can constitute the hole injection layer 111 described above. It is preferable to form the P-type layer using the composite material listed as a material that can be used. As the materials constituting the substrate, a film containing the above-mentioned acceptor material and a film containing a hole transport material are stacked. By applying a potential to the P-type layer, electrons are transported to the electron transport layer 114. , holes are injected into the cathode 102, and the light-emitting device operates.

[0127] The charge generating layer may be either an electron relay layer or an electron injection buffer layer in addition to the P-type layer. It is preferable to have both.

[0128] The electron relay layer contains at least a material having electron transport properties, and the electron injection buffer layer and the P-type layer The electron relay layer has the function of preventing interactions with the The LUMO level of the electron-transporting material is the same as the LUMO level of the electron-accepting material in the P-type layer. and the LUMO level of the substance contained in the layer in contact with the charge generating layer in the electron transport layer 114. In the electron-relay layer, the electron-transporting material is preferably between The specific energy level of the LUMO level is −5.0 eV or higher, preferably −5.0 eV or higher. The upper limit is preferably −3.0 eV or less. The materials are phthalocyanine-based materials or metal complexes with metal-oxygen bonds and aromatic ligands. Preferably, the body is used.

[0129] The electron injection buffer layer may contain alkali metals, alkaline earth metals, rare earth metals, and their derivatives. Compounds of alkali metal compounds (oxides such as lithium oxide, halides, lithium carbonate and carbonates such as cesium carbonate), alkaline earth metal compounds (oxides, halides, carbonates), or compounds of rare earth metals (including oxides, halides, and carbonates) It is possible to use a substance having high electron injection properties, such as the following.

[0130] The electron injection buffer layer is formed by containing a substance having an electron transporting property and an electron donating substance. When the electron donor is an alkali metal, an alkaline earth metal, a rare earth metal, and their compounds (alkali metal compounds (oxides such as lithium oxide, halides, carbonates such as lithium carbonate and cesium carbonate), alkaline earth metal compounds (oxides, halogens, etc.) compounds of rare earth metals (including oxides, halides, carbonates) In addition to tetrathianaphthacene (including salts), nickelocene, decamethyl An organic compound such as nickelocene can also be used. In this case, the electron transport layer 114 may be formed using the same material as that constituting the electron transport layer 114 described above. can be done.

[0131] The material for forming the cathode 102 is gold, which has a small work function (specifically, 3.8 eV or less). Metals, alloys, electrically conductive compounds, and mixtures thereof can be used. Specific examples of such cathode materials include alkali metals such as lithium (Li) and cesium (Cs). , and elements such as magnesium (Mg), calcium (Ca), and strontium (Sr) Elements belonging to Group 1 or 2 of the periodic table and alloys containing these elements (MgAg, AlL i), europium (Eu), ytterbium (Yb), and other rare earth metals, and However, an electron injection layer may be provided between the cathode 102 and the electron transport layer. By providing this, regardless of the magnitude of the work function, Al, Ag, ITO, silicon or oxide Various conductive materials such as silicon dioxide-containing indium oxide-tin oxide can be used as the cathode 102. You can be there. These conductive materials can be applied by dry methods such as vacuum deposition and sputtering, inkjet printing, It is possible to form the film using a spin coating method, etc. Also, it is possible to form the film using a wet sol-gel method. Alternatively, it may be formed by a wet method using a paste of a metal material.

[0132] The EL layer 103 can be formed by various methods, including dry and wet methods. For example, vacuum deposition, gravure printing, offset printing, screen printing, etc. A printing method, an ink jet method, a spin coating method, or the like may also be used.

[0133] Furthermore, the above-mentioned electrodes or layers may be formed using different film formation methods.

[0134] The structure of the layer provided between the anode 101 and the cathode 102 is not limited to the above. However, the proximity of the light-emitting region to the metals used in the electrodes and carrier injection layer In order to suppress quenching caused by the hole It is preferable to provide a light-emitting region where the electrons recombine with the cathode.

[0135] Furthermore, recombination in the hole transport layer or electron transport layer in contact with the light-emitting layer 113, particularly in the light-emitting layer 113 The carrier transport layer close to the region suppresses energy transfer from excitons generated in the light-emitting layer. Therefore, the band gap is determined by the luminescent material that constitutes the luminescent layer or the luminescent material contained in the luminescent layer. It is preferable that the material be made of a substance having a band gap larger than that of the material.

[0136] Next, we developed a light-emitting device (a stacked element, a tandem element) that has a structure in which multiple light-emitting units are stacked. The embodiment of the light-emitting device (also referred to as a "light-emitting device") will be described with reference to FIG. A light-emitting device has multiple light-emitting units between the electrode and the cathode. The EL layer 103 has a structure similar to that of the EL layer 103 shown in FIG. The light-emitting device shown in FIG. 1C is a light-emitting device having a plurality of light-emitting units. The light-emitting device shown in Fig. 1(A) and Fig. 1(B) is a light-emitting device having one light-emitting unit. It can be said that this is

[0137] In FIG. 1C, a first light-emitting unit 511 and a second light-emitting unit 512 are disposed between the anode 501 and the cathode 502. The second light-emitting unit 512 is stacked, and the first light-emitting unit 511 and the second light-emitting unit A charge generating layer 513 is provided between the anode 501 and the cathode 502. These correspond to the anode 101 and the cathode 102 in FIG. 1(A), respectively, and are described in the explanation of FIG. 1(A). The same as that used for the first light-emitting unit 511 and the second light-emitting unit 512 can be applied. The optical units 512 may be of the same or different construction.

[0138] When a voltage is applied between the anode 501 and the cathode 502, the charge generating layer 513 generates a light emitting The electron-injecting unit has the function of injecting electrons into one light-emitting unit and holes into the other light-emitting unit. In 1(C), when a voltage is applied so that the anode potential is higher than the cathode potential, In this case, the charge generating layer 513 injects electrons into the first light-emitting unit 511 and Any material capable of injecting holes into the gate 512 may be used.

[0139] The charge generating layer 513 is preferably formed to have the same structure as the charge generating layer described above. Composite materials of compounds and metal oxides have excellent carrier injection and carrier transport properties, It is possible to realize low voltage and low current driving. When the charge generating layer 513 is in contact with the charge generating layer 513, the charge generating layer 513 serves as a hole injection layer of the light emitting unit. Since the light-emitting unit can also serve as a hole-injection layer, the light-emitting unit does not need to be provided with a hole-injection layer.

[0140] In addition, when an electron injection buffer layer is provided in the charge generation layer 513, the electron injection buffer layer To play the role of an electron injection layer in the light-emitting unit on the anode side, It is not always necessary to form an electron injection layer.

[0141] Although the light-emitting device having two light-emitting units has been described in FIG. 1C, the light-emitting device having three or more light-emitting units may be used. The same can be applied to a light-emitting device in which the above light-emitting units are stacked. As in the light-emitting device according to the present embodiment, a plurality of light-emitting units are electrically connected between a pair of electrodes. By separating the layers with the generation layer 513, high brightness light emission is possible while keeping the current density low. This allows for an even longer-life element. The device can be realized.

[0142] In addition, by making the light color of each light-emitting unit different, the light-emitting device as a whole can be For example, a light-emitting device having two light-emitting units can be used to obtain light of a desired color. In this device, the first light-emitting unit emits red and green light, and the second light-emitting unit emits blue light. By obtaining a color, it is possible to obtain a light-emitting device that emits white light as a whole. Furthermore, examples of the configuration of a light-emitting device in which three or more light-emitting units are stacked include: The first light-emitting unit has a first blue light-emitting layer, and the second light-emitting unit has a yellow or yellow-green light-emitting layer. the third light-emitting unit has a second blue light-emitting layer; The tandem device may be a tandem device having the above-mentioned light-emitting device. As with the chair, white light can be obtained.

[0143] In addition, the EL layer 103, the first light-emitting unit 511, the second light-emitting unit 512, and Each layer such as the charge generating layer and the electrodes can be formed by, for example, a vapor deposition method (including a vacuum deposition method), a droplet discharge method (including an ink jet method), or the like. It can be formed by using methods such as ink jet printing, coating, and gravure printing. They can be used in a variety of applications, including low molecular weight materials, medium molecular weight materials (including oligomers and dendrimers), and or polymeric material.

[0144] (Embodiment 3) In this embodiment, light emission using the light-emitting device described in the first and second embodiments is The device will now be described.

[0145] In this embodiment, a light-emitting device described in Embodiments 1 and 2 is used to manufacture a The light-emitting device will be described with reference to FIG. 2. Note that FIG. 2(A) shows the light-emitting device. 2(B) is a cross-sectional view taken along lines AB and CD in FIG. 2(A). The device includes a drive circuit section (source) shown by a dotted line that controls the light emission of the light emitting device. The pixel section 602 includes a gate line driving circuit section (gate line driving circuit) 601, a pixel section 602, and a driving circuit section (gate line driving circuit) 603. Further, 604 is a sealing substrate, 605 is a sealing material, and the inside surrounded by the sealing material 605 has become space 607.

[0146] The lead wiring 608 is connected to the source line driver circuit 601 and the gate line driver circuit 603. The wiring is for transmitting signals, and the FPC (flexible printed circuit board) is the external input terminal. Video signal, clock signal, start signal, reset signal, etc. from the input circuit 609 Although only the FPC is shown here, this FPC has a printed wiring board. The light emitting device in this specification may be a light emitting device. This includes not only the device itself but also the state in which an FPC or PWB is attached to it. do.

[0147] Next, the cross-sectional structure will be described with reference to FIG. A source line driver circuit 601 and a pixel portion are formed. , one pixel in the pixel section 602 is shown.

[0148] The element substrate 610 may be a substrate made of glass, quartz, organic resin, metal, alloy, semiconductor, or the like. FRP (Fiber Reinforced Plastics), PVF (Polyvinyl It is made using a plastic substrate made of, for example, fluoride, polyester, or acrylic. That's fine.

[0149] The structure of the transistors used in the pixels and driver circuits is not particularly limited. The transistor may be a top-type transistor or a staggered type transistor. The transistor may be a gate type transistor or a bottom gate type transistor. The semiconductor material is not particularly limited, and examples thereof include silicon, germanium, silicon carbide, and nitride. Gallium or the like can be used. Alternatively, in-type metal oxides such as In-Ga-Zn-based metal oxides can be used. An oxide semiconductor containing at least one of tungsten, gallium, and zinc may be used.

[0150] The crystallinity of the semiconductor material used in the transistor is not particularly limited. A semiconductor having crystallinity (microcrystalline semiconductor, polycrystalline semiconductor, single crystal semiconductor, or a semiconductor having a partially crystalline region) When a semiconductor having crystallinity is used, the transistor This is preferable because it can suppress deterioration of the star characteristics.

[0151] Here, in addition to the transistors provided in the pixels and the driver circuits, It is preferable to use an oxide semiconductor for a semiconductor device such as a transistor. In particular, it is preferable to use an oxide semiconductor having a wider band gap than silicon. By using an oxide semiconductor with a wider band gap than silicon, the off-state of the transistor can be This can reduce the current in the

[0152] The oxide semiconductor preferably contains at least indium (In) or zinc (Zn). In addition, In-M-Zn oxides (where M is Al, Ti, Ga, Ge, Y, Zr, Sn, It is preferable that the oxide semiconductor contains an oxide represented by the formula (metal such as La, Ce or Hf). More preferable.

[0153] Here, an oxide semiconductor that can be used in one embodiment of the present invention will be described below. .

[0154] Oxide semiconductors are divided into single-crystal oxide semiconductors and other non-single-crystal oxide semiconductors. As a non-single-crystal oxide semiconductor, for example, CAAC-OS (c-axis alignable oxide semiconductor) gned crystalline oxide semiconductor), polycrystalline nc-OS (nano crystalline oxide semiconductor) semiconductor), pseudo-amorphous oxide semiconductor (a-like OS) amorphous-like oxide semiconductor), and amorphous oxide semiconductor Conductors, etc.

[0155] CAAC-OS has a c-axis orientation and multiple nanocrystals are connected in the ab-plane direction. The crystal structure has distortion. The distortion is the area where multiple nanocrystals are connected. In the region, the lattice arrangement is changed between a region with a uniform lattice arrangement and another region with a uniform lattice arrangement. Indicates the point where the direction is changing.

[0156] Nanocrystals are basically hexagonal, but they are not limited to regular hexagonal shapes and may be non-regular hexagonal. The distortion may also have lattice arrangements such as pentagons and heptagons. In CAAC-OS, clear grain boundaries (grain boundaries) are observed even near the strain. It is difficult to confirm the presence of grains due to distortion of the lattice arrangement. This is because the CAAC-OS has a crystalline structure in the ab-plane direction. The oxygen atoms are not densely packed, and the bond distance between atoms is shortened by the substitution of metal elements. This is because distortion can be tolerated by changing the frequency.

[0157] In addition, the CAAC-OS has a layer containing indium and oxygen (hereinafter referred to as an In layer) and an element A layered crystal structure in which layers containing M, zinc, and oxygen (hereinafter referred to as (M, Zn) layers) are stacked. It is noted that indium and element M tend to have a layered structure. It is possible, and when the element M in the (M,Zn) layer is replaced with indium, (In,M,Zn) Also, when indium in the In layer is replaced with element M, (In,M ) layer.

[0158] CAAC-OS is an oxide semiconductor with high crystallinity. Since it is difficult to identify grain boundaries, the decrease in electron mobility caused by grain boundaries is unlikely to occur. In addition, the crystallinity of oxide semiconductors is degraded by the inclusion of impurities and the generation of defects. Therefore, CAAC-OS should be free from impurities and defects (oxygen vacancies (V O :oxygen Therefore, CAA Oxide semiconductors containing C-OS have stable physical properties. The oxide semiconductor has high heat resistance and high reliability.

[0159] nc-OS is a material that can be used in microscopic areas (e.g., areas between 1 nm and 10 nm, especially areas between 1 nm and 3 nm). The nc-OS has periodic atomic arrangement in the nanometer range (nm or less). There is no regularity in the crystal orientation between the crystals. Therefore, no orientation is observed throughout the film. Therefore, depending on the analysis method, nc-OS may be distinguished from a-like OS or amorphous oxide semiconductor. It may be difficult to distinguish between the two.

[0160] Note that indium, gallium, and zinc are oxide semiconductors. The IGZO nanocrystals mentioned above are stable. In particular, IGZO tends to have difficulty growing crystals in the atmosphere. , small crystals (e.g., crystals of several mm or several cm) are more likely to be formed than large crystals (here, crystals of several mm or several cm). For example, the nanocrystals mentioned above may be structurally more stable.

[0161] The a-like OS is an oxide semiconductor with a structure between the nc-OS and amorphous oxide semiconductor. Conductive. A-like OS has voids or low density regions. The ke-OS has lower crystallinity than the nc-OS and CAAC-OS.

[0162] Oxide semiconductors have a variety of structures, each of which has different characteristics. Oxide semiconductors include amorphous oxide semiconductors, polycrystalline oxide semiconductors, a-like OS, and nc The compound may have two or more of -OS and CAAC-OS.

[0163] In addition to the oxide semiconductors mentioned above, Cloud-Aligned Computing (CAC) osite)-OS may also be used.

[0164] CAC-OS is a material that has a conductive function in some parts and an insulating function in other parts. The material as a whole functions as a semiconductor. When used in the active layer, the conductive function is to allow electrons (or holes) to flow as carriers. The insulating function is to prevent the flow of electrons, which act as carriers. By making the functions of the gate and the insulating function work in a complementary manner, the switching function (O On / Off function) can be added to CAC-OS. By separating the functions of each, the functions of both can be maximized.

[0165] The CAC-OS also has a conductive region and an insulating region. The insulating region has the above-mentioned insulating function. In some cases, the conductive and insulating regions are separated at the nanoparticle level. The conductive and insulating regions may be unevenly distributed in the material. may be observed as a cloud-like cluster with the periphery blurred.

[0166] In addition, in CAC-OS, the conductive region and the insulating region are each 0.5 nm or more. When the particles are dispersed in the material in a size of 10 nm or less, preferably 0.5 nm to 3 nm, There is a match.

[0167] In addition, the CAC-OS is composed of components having different band gaps. For example, CAC-OS consists of a wide-gap component originating from the insulating region and a conductive component originating from the conductive region. In this configuration, the carrier is When the carriers flow, they mainly flow in the narrow gap component. The component with a gap acts complementary to the component with a wide gap, Carriers flow into the wide-gap component in conjunction with the wide-gap component. When the CAC-OS is used in a channel forming region of a transistor, In the on state, a high current driving force, i.e., a large on-current, and a high field-effect mobility are obtained. It is possible.

[0168] That is, CAC-OS is a matrix composite. , or metal matrix composite It can also be called.

[0169] By using the above-mentioned oxide semiconductor material for the semiconductor layer, fluctuations in electrical characteristics are suppressed and reliability is improved. This makes it possible to realize highly reliable transistors.

[0170] Furthermore, the transistor having the above-described semiconductor layer can be used as a transistor due to its low off-state current. It is possible to retain the charge stored in the capacitor for a long period of time through such a transistor. By applying a transistor to each pixel, the gradation of the image displayed in each display area can be maintained while driving It is also possible to shut down the circuit. As a result, electronic devices with extremely low power consumption can be realized. It can be realized.

[0171] For stabilizing the characteristics of the transistor, it is preferable to provide an underlayer film. Inorganic films such as silicon oxide film, silicon nitride film, silicon oxynitride film, and silicon nitride oxide film The insulating film can be formed as a single layer or a laminated layer. CVD (Chemical Vapor Deposition) method (Plasma CVD method) , thermal CVD method, MOCVD (Metal Organic CVD) method, etc.), ALD ( Formed using Atomic Layer Deposition (ALD), coating, printing, etc. It should be noted that the undercoat film need not be provided if it is not necessary.

[0172] The FET 623 indicates one of the transistors formed in the driving circuit section 601. The drive circuit is made up of various CMOS circuits, PMOS circuits, or NMOS circuits. In this embodiment, a driver integrated type in which a driver circuit is formed on a substrate is shown. However, this is not necessarily required, and the drive circuit can be formed externally rather than on the substrate. .

[0173] The pixel section 602 includes a switching FET 611, a current control FET 612 and its driver. The pixel is formed by a plurality of pixels including an anode 613 electrically connected to the drain. However, the present invention is not limited to this, and the pixel section may be a combination of three or more FETs and a capacitance element.

[0174] An insulator 614 is formed to cover the end of the anode 613. It can be formed by using a photosensitive acrylic.

[0175] In order to improve the coverage of the EL layer and the like to be formed later, the insulating material 614 is For example, the material of the insulator 614 is When a positive photosensitive acrylic is used, the radius of curvature (0. It is preferable that the insulating material 614 has a curved surface with a thickness of 2 μm to 3 μm. Either a negative photosensitive resin or a positive photosensitive resin can be used.

[0176] An EL layer 616 and a cathode 617 are formed on the anode 613. It is desirable to use a material with a large work function for the anode 613. For example, ITO film, or silicon-containing indium tin oxide film, 2 to 20 wt% oxide Zinc-containing indium oxide film, titanium nitride film, chromium film, tungsten film, Zn film, Pt In addition to single layer films such as titanium nitride films, laminated films with aluminum as the main component, titanium nitride films, A three-layer structure of a titanium nitride film, a film mainly composed of aluminum, and the like can be used. Furthermore, the multilayer structure provides low resistance as wiring and good ohmic contact. It can also function as an anode.

[0177] The EL layer 616 can be formed by a deposition method using a deposition mask, an inkjet method, or a spin coating method. The EL layer 616 is formed by various methods such as those described in the first and second embodiments. Other materials that make up the EL layer 616 include: It may be a low molecular weight compound or a high molecular weight compound (including an oligomer or dendrimer). .

[0178] Furthermore, the material used for the cathode 617 formed on the EL layer 616 is a material having a small work function. Materials with low resistance (Al, Mg, Li, Ca) or their alloys or compounds (MgAg, MgIn, It is preferable to use AlLi, etc. When light is transmitted through the cathode 617, a thin metal film and a transparent conductive film (I TO, indium oxide containing 2-20 wt% zinc oxide, indium tin containing silicon It is preferable to use a laminate of an oxide such as zinc oxide (ZnO).

[0179] The anode 613, the EL layer 616, and the cathode 617 form a light-emitting device. The light-emitting device is the light-emitting device described in the first and second embodiments. The pixel portion is formed with a plurality of light-emitting devices. The device includes the light-emitting device described in the first and second embodiments and other components. The light emitting device may include both a light emitting device having a light emitting element and a light emitting device having a light emitting element.

[0180] Furthermore, the sealing substrate 604 is bonded to the element substrate 610 with a sealing material 605. A light-emitting device is placed in a space 607 surrounded by a sub-substrate 610, a sealing substrate 604, and a sealing material 605. The space 607 is filled with a filler material. In some cases, the gas is filled with an inert gas (nitrogen, argon, etc.), and in other cases, it is filled with a sealing material. By forming a recess in the sealing substrate and providing a desiccant there, deterioration due to the influence of moisture can be prevented. This is a preferable configuration because it can suppress the degradation.

[0181] It is preferable to use epoxy resin or glass frit for the sealing material 605. It is desirable that these materials be as impermeable to moisture and oxygen as possible. Materials used for the sealing substrate 604 include glass substrates, quartz substrates, and FRP (Fiber Reinforced Plastics). reinforced plastics), PVF (polyvinyl fluoride), polyester A plastic substrate made of polyethylene or acrylic can be used.

[0182] Although not shown in FIG. 2(B), a protective film may be provided on the cathode. The protective film is an organic resin film. The exposed portion of the sealant 605 may be covered with a protective film. A protective film may be formed on the surfaces and sides of the pair of substrates, the sealing layer, the insulating layer, and the like. A rim layer, etc. may be provided over the exposed side surface.

[0183] The protective film can be made of a material that is difficult for impurities such as water to permeate. It is possible to effectively prevent impurities such as these from diffusing from the outside to the inside.

[0184] The materials that make up the protective film include oxides, nitrides, fluorides, sulfides, ternary compounds, and metals. Alternatively, polymers and the like can be used, for example, aluminum oxide, hafnium oxide, hafnium Lanthanum silicate, lanthanum oxide, silicon oxide, strontium titanate, tantalum oxide , titanium oxide, zinc oxide, niobium oxide, zirconium oxide, tin oxide, yttrium oxide , cerium oxide, scandium oxide, erbium oxide, vanadium oxide or indium oxide Materials containing hafnium, aluminum nitride, hafnium nitride, silicon nitride, tantalum nitride, titanium nitride, niobium nitride, molybdenum nitride, zirconium nitride, or gallium nitride, etc. Materials, nitrides containing titanium and aluminum, oxides containing titanium and aluminum , oxides containing aluminum and zinc, sulfides containing manganese and zinc, cerium and sulfides containing erbium and strontium, oxides containing erbium and aluminum, yttrium Materials containing oxides containing lithium and zirconium can be used.

[0185] The protective film can be formed using a film formation method that provides good step coverage. One such method is atomic layer deposition (ALD). The ALD method can be used to form protective materials. It is preferable to use it for films. By using the ALD method, it is possible to eliminate cracks, pinholes, etc. It is possible to form a protective film with reduced defects or with a uniform thickness. Damage to the processed member when forming the protective film can be reduced.

[0186] For example, by forming a protective film using the ALD method, it is possible to fabricate a surface with complex irregularities or a surface with a touch panel. A uniform protective film with few defects can be formed on the top, sides and back of the panel. .

[0187] As described above, the light-emitting devices described in the first and second embodiments were used to manufacture the A light emitting device having such a structure can be obtained.

[0188] The light emitting device of the present embodiment is the same as the light emitting device of the first and second embodiments. Since the semiconductor device is used, it is possible to obtain a light emitting device with excellent characteristics. The light emitting devices described in the first and second embodiments are light emitting devices with long lifetimes. Therefore, a light emitting device with good reliability can be obtained. 2. A light-emitting device using the light-emitting device described in 2. has good luminous efficiency, and therefore consumes little power. It may be an optical device.

[0189] In Fig. 3(A) and Fig. 3(B), a light-emitting device that emits white light is formed, and a colored layer (color An example of a full-color light-emitting device is shown in Figure 3(A). The substrate 1001 includes an insulating base film 1002, a gate insulating film 1003, a gate electrode 1006, 1007, 1008, first interlayer insulating film 1020, second interlayer insulating film 1021, peripheral portion 1 042, pixel section 1040, drive circuit section 1041, anode 1024W of the light-emitting device, 102 4R, 1024G, 1024B, partition wall 1025, EL layer 1028, cathode 1 of light-emitting device 029, a sealing substrate 1031, a sealing material 1032, and the like are shown.

[0190] In addition, in FIG. 3(A), the colored layers (red colored layer 1034R, green colored layer 1034G, blue The colored layer 1034B is provided on a transparent substrate 1033. A transparent substrate 1 having a colored layer and a black matrix may be further provided. The colored layer and the black matrix are aligned and fixed to the substrate 1001. The dust 1035 is covered with an overcoat layer 1036. The light-emitting layer is where light does not pass through the colored layers and goes out, and the light passes through the colored layers of each color and goes out. The light that does not pass through the colored layer is white, and the light that passes through the colored layer is red, green, or blue. This allows images to be expressed using four color pixels.

[0191] In FIG. 3(B), the colored layers (red colored layer 1034R, green colored layer 1034G, blue colored layer An example in which a layer 1034B) is formed between the gate insulating film 1003 and the first interlayer insulating film 1020 As shown in the figure, the colored layer is provided between the substrate 1001 and the sealing substrate 1031. Good too.

[0192] In the light emitting device described above, light is taken in toward the substrate 1001 on which the FET is formed. The light emitting device has a bottom emission structure, but the light is taken in from the sealing substrate 1031 side. The light emitting device may have a top emission structure. A cross-sectional view of the light-emitting device is shown in FIG. 4. In this case, a substrate that does not transmit light is used as the substrate 1001. Until the connection electrode that connects the FET and the anode of the light-emitting device is fabricated, After that, a third interlayer insulating film 1037 is formed on the substrate 1031 in the same manner as in the case of the multi-emission light emitting device. The insulating film is formed to cover the electrode 1022. This insulating film may also serve as a planarizing layer. The interlayer insulating film 1037 may be formed using the same material as the second interlayer insulating film, or other known materials. It is possible.

[0193] The anodes 1024W, 1024R, 1024G, and 1024B of the light-emitting device are the anodes here. However, it may be formed as a cathode. In the case of an optical device, it is preferable that the anode is a reflective electrode. The EL layer 103 has the same structure as that described in the first and second embodiments, and In addition, the device structure is designed to produce white light emission.

[0194] In the top emission structure shown in Figure 4, the colored layers (red colored layer 1034R, green colored layer The sealing is performed by a sealing substrate 1031 provided with a blue color layer 1034G and a blue color layer 1034B. The sealing substrate 1031 has a black matrix disposed between the pixels. A coloring layer (red coloring layer 1034R, green coloring layer 1034G, The blue colored layer 1034B) and the black matrix are covered by the overcoat layer 1036. The sealing substrate 1031 may be a light-transmitting substrate. Although an example of full-color display using four colors, red, green, blue, and white, is shown here, there is no particular limitation. Alternatively, full color display may be performed using four colors of red, yellow, green, and blue, or three colors of red, green, and blue.

[0195] In a top-emission type light-emitting device, the microcavity structure can be suitably applied. The light-emitting device with a microcavity structure uses the anode as a reflective electrode and the cathode as a semi-transparent / semi-reflective electrode. At least one electrode is provided between the reflective electrode and the semi-transparent / semi-reflective electrode. It has an EL layer, and at least has a light-emitting layer that becomes a light-emitting region.

[0196] The reflectance of the reflective electrode for visible light is 40% to 100%, preferably 70% to 100%. %, and its resistivity is 1×10 -2 The film is assumed to be less than Ωcm. The semi-reflective electrode has a visible light reflectance of 20% to 80%, preferably 40% to 70%. , and its resistivity is 1×10 -2 It is assumed that the film has a resistance of Ωcm or less.

[0197] The light emitted from the light-emitting layer included in the EL layer is reflected by the reflective electrode and the semi-transparent and semi-reflective electrode. The sound is reflected and resonates.

[0198] The light-emitting device is made by changing the thickness of the transparent conductive film, the composite material, the carrier transport material, etc. By doing so, the optical distance between the reflective electrode and the semi-transmissive / semi-reflective electrode can be changed. This strengthens the light of the resonating wavelength between the reflective electrode and the semi-transparent and semi-reflective electrode, and It can attenuate light of wavelengths that are not

[0199] The light reflected by the reflective electrode and returned (first reflected light) is semi-transmitted from the light emitting layer. The light that directly enters the semi-reflective electrode (first incident light) interferes greatly with the reflective electrode. The optical distance of the light-emitting layer is (2n-1)λ / 4 (where n is a natural number greater than or equal to 1, and λ is the amplified It is preferable to adjust the optical distance to a wavelength of the first light. By matching the phase of the reflected light with the phase of the first incident light, the light emitted from the light-emitting layer can be further amplified. do.

[0200] In the above configuration, even if the EL layer has a plurality of light-emitting layers, a single light-emitting For example, it may be combined with the above-mentioned tandem light-emitting device configuration. In addition, multiple EL layers are provided in one light-emitting device with a charge generating layer sandwiched between them, and each EL The layer may be configured to have one or more light-emitting layers.

[0201] The microcavity structure makes it possible to enhance the front-direction emission intensity of specific wavelengths. This allows for lower power consumption. In the case of a light-emitting device that displays images using a single pixel, the yellow light emission not only improves brightness, but also Since a microcavity structure tailored to the wavelength of each color can be applied, it is possible to achieve light-emitting devices with excellent characteristics. It can be placed.

[0202] The light emitting device of the present embodiment is the same as the light emitting device of the first and second embodiments. Since the semiconductor device is used, it is possible to obtain a light emitting device with excellent characteristics. The light emitting devices described in the first and second embodiments are light emitting devices with long lifetimes. Therefore, a light emitting device with good reliability can be obtained. 2. A light-emitting device using the light-emitting device described in 2. has good luminous efficiency, and therefore consumes little power. It may be an optical device.

[0203] (Fourth embodiment) In this embodiment, the light-emitting device according to any one of the first and second embodiments is used as a lighting device. An example of using the lighting fixture will be described with reference to Figs. 5(A) and 5(B). FIG. 5(A) is a top view of the device, and is a cross-sectional view taken along line ef in FIG. 5(B).

[0204] The lighting device of this embodiment has an anode 4 on a light-transmitting substrate 400 serving as a support. The anode 401 corresponds to the anode 101 in the second embodiment. When light is extracted from the anode 401 side, the anode 401 is formed from a light-transmitting material.

[0205] A pad 412 for supplying a voltage to the cathode 404 is formed on the substrate 400 .

[0206] An EL layer 403 is formed on the anode 401. The EL layer 403 is the same as that in the first embodiment and the second embodiment. The configuration of the EL layer 103 in the second embodiment, or the light-emitting units 511 and 512 and the charge generation This corresponds to a configuration in which the layer 513 is combined. For details of these configurations, refer to the relevant description. I want to be done that.

[0207] A cathode 404 is formed to cover the EL layer 403. The cathode 404 is the same as the cathode 1 in the second embodiment. When light is extracted from the anode 401 side, the cathode 404 is made of a material with high reflectivity. The cathode 404 is connected to a pad 412, and a voltage is applied to the cathode 404. can be.

[0208] As described above, the light-emitting device having the anode 401, the EL layer 403, and the cathode 404 is The lighting device shown in FIG. 1 has a high luminous efficiency. Therefore, the lighting device in this embodiment can be a lighting device with low power consumption.

[0209] The substrate 400 on which the light emitting device having the above structure is formed is sealed with a sealing substrate 407. The lighting device is completed by fixing and sealing using sealing materials 405 and 406. Either 405 or 406 may be used. In addition, the inner seal material 406 (see FIG. 5(B)) ) (not shown) can also be mixed with a desiccant, which can absorb moisture. This leads to improved reliability.

[0210] In addition, a part of the pad 412 and the anode 401 is provided so as to extend outside the sealing materials 405 and 406. By doing so, it can be used as an external input terminal. An IC chip 420 or the like may be provided.

[0211] As described above, the lighting device according to the present embodiment uses the EL element according to the first and second embodiments. The light emitting device described above can be used to provide a light emitting device with good reliability. A light-emitting device with low power consumption can be provided.

[0212] (Embodiment 5) In this embodiment, the light emitting device according to the first and second embodiments is used as a part thereof. An example of an electronic device including the light-emitting device according to the first embodiment and the second embodiment will be described. The device has a long life and is a highly reliable light-emitting device. The electronic device described in the above item 1 can be an electronic device having a light emitting section with good reliability.

[0213] Examples of electronic devices to which the light-emitting device is applied include television sets (televisions, (also called television receivers), computer monitors, digital cameras, digital digital video cameras, digital photo frames, mobile phones (also known as mobile phones or mobile phone devices) (hereinafter referred to as "games"), portable game machines, personal digital assistants, sound reproduction devices, large game machines such as pachinko machines Specific examples of these electronic devices are listed below.

[0214] 6A shows an example of a television device. The television device includes a housing 710 A display unit 7103 is built into the housing 1. In this case, a stand 7105 is used to hold the housing The display unit 7103 can display images. The display portion 7103 is configured using the light-emitting device described in Embodiments 1 and 2. They are arranged in a matrix.

[0215] The television device can be operated using the operation switches on the housing 7101 or a separate remote control. This can be done by the remote control device 7110. This allows you to control the channel and volume, and the image displayed on the display unit 7103 In addition, the remote control operation device 7110 can be operated. A display portion 7107 for displaying information output from the

[0216] The television device is assumed to be equipped with a receiver, modem, etc. It can receive television broadcasts and can also communicate by wire or wireless via a modem. By connecting to a network, you can send and receive data in one direction (sender to receiver) or two directions (sender to receiver). It is also possible to communicate information between the recipient and the receiver, or between receivers themselves.

[0217] FIG. 6(B1) shows a computer, which includes a main body 7201, a housing 7202, a display unit 7203, and a keyboard. keyboard 7204, external connection port 7205, pointing device 7206, etc. The computer may be configured to use the light-emitting devices described in the first and second embodiments. The liquid crystal display panels are arranged in a matrix and used in the display portion 7203. The computer may have a form as shown in FIG. 6(B2). The keyboard 7204 and the pointing device 7206 are replaced by a second display unit 7207. The second display portion 7210 is a touch panel type. The input display on the display unit 7210 is operated with a finger or a special pen. The second display portion 7210 can be used not only for input display but also for other displays. The display unit 7203 may also be a touch panel. The two screens are connected by a hinge, which can damage the screen when storing or transporting it. This also prevents problems such as breakage.

[0218] FIG. 6C shows an example of a mobile terminal. The mobile phone is built in a housing 7401. In addition to the display unit 7402, operation buttons 7403, an external connection port 7404, a speaker 740 5, a microphone 7406, etc. The mobile phone is the same as that of the first embodiment and the second embodiment. A display portion 7402 in which the light-emitting devices according to embodiment 2 are arranged in a matrix is ​​provided. are.

[0219] The mobile terminal shown in FIG. 6C allows users to input information by touching the display portion 7402 with a finger or the like. In this case, it is possible to make a call or create an email. Operations such as turning on / off the camera can be performed by touching the display portion 7402 with a finger or the like.

[0220] The screen of the display unit 7402 has three main modes. The first is a display mode that mainly displays images. The first mode is a display mode, and the second mode is an input mode that mainly inputs information such as characters. This is a display + input mode that combines two modes: display mode and input mode.

[0221] For example, when making a call or creating an email, the display unit 7402 is used to input characters. This is the main character input mode, and you can input characters displayed on the screen. It is preferable to display a keyboard or number buttons on most of the screen of the display portion 7402. I wish.

[0222] In addition, the mobile terminal may include a sensor for detecting tilt, such as a gyro or acceleration sensor. By providing a device, the orientation of the mobile terminal (portrait or landscape) can be determined and the screen display of the display portion 7402 can be displayed. The display can be switched automatically.

[0223] The screen mode can be switched by touching the display portion 7402 or by operating the housing 7401. This is done by operating the button 7403. Also, depending on the type of image displayed on the display unit 7402, For example, if the image signal to be displayed on the display unit is a video signal, If it is data, the display mode is switched to, and if it is text data, the input mode is switched to.

[0224] In the input mode, the optical sensor of the display unit 7402 detects a signal and displays it. If there is no input by touch operation on the part 7402 for a certain period of time, the screen mode is changed to the input mode. Alternatively, the display mode may be switched from the normal mode to the display mode.

[0225] The display portion 7402 can also function as an image sensor. By touching the device with your palm or fingers and capturing an image of your palm print or fingerprint, you can authenticate your identity. In addition, a backlight that emits near-infrared light to the display unit or a sensing light that emits near-infrared light By using a source, it is also possible to image finger veins, palm veins, etc.

[0226] Note that the structure described in this embodiment mode may be obtained by appropriately combining the structures described in any of Embodiment Modes 1 to 4. They can be used in combination.

[0227] As described above, the light emitting device according to the first and second embodiments can be applied to the light emitting apparatus. The range of applications is extremely wide, and this light-emitting device can be applied to electronic devices in a wide range of fields. By using the light emitting devices described in the first and second embodiments, reliability is improved. You can get high quality electronic equipment.

[0228] FIG. 7(A) is a schematic diagram showing an example of a cleaning robot.

[0229] The cleaning robot 5100 has a display 5101 on the top surface and multiple The camera 5102, the brush 5103, and the operation button 5104 are also shown. However, the underside of the cleaning robot 5100 is provided with tires, a suction port, etc. The robot 5100 also has an infrared sensor, an ultrasonic sensor, an acceleration sensor, a piezo sensor, It is equipped with various sensors such as a sensor, a light sensor, and a gyro sensor. 100 is equipped with wireless communication means.

[0230] The cleaning robot 5100 moves by itself, detects the dust 5120, and sucks it out from the suction port on the bottom. It can suck up dirt.

[0231] In addition, the cleaning robot 5100 analyzes the image captured by the camera 5102 and detects the wall, furniture, or It can detect obstacles such as steps. Image analysis can also detect obstacles such as wiring. If an object that may get tangled in the brush 5103 is detected, the rotation of the brush 5103 can be stopped. can.

[0232] The display 5101 can display the remaining battery level and the amount of dust sucked. The route traveled by the cleaning robot 5100 can be displayed on the display 5101. In addition, the display 5101 is a touch panel, and the operation button 5104 is It may be provided in the ray 5101.

[0233] The cleaning robot 5100 can communicate with a portable electronic device 5140 such as a smartphone. The images captured by the camera 5102 can be displayed on the portable electronic device 5140. Therefore, the owner of the Cleaning Robot 5100 can check the status of the room even when he is away from home. In addition, the display on the display 5101 can be displayed on a mobile electronic device such as a smartphone. You can also check it out at.

[0234] The light-emitting device according to one embodiment of the present invention can be used for the display 5101 .

[0235] The robot 2100 shown in FIG. 7(B) includes a computing device 2110, an illuminance sensor 2101, a microphone 2102, upper camera 2103, speaker 2104, display 2105, It is equipped with an internal camera 2106, an obstacle sensor 2107, and a movement mechanism 2108.

[0236] The microphone 2102 has a function of detecting the user's voice and environmental sounds. The speaker 2104 has a function of emitting sound. The device 2102 and the speaker 2104 can be used to communicate with the user. It is possible.

[0237] The display 2105 has the function of displaying various information. Any information desired by the user can be displayed on the display 2105. The display 2105 may be equipped with a touch panel. The robot 2100 may be an information terminal that can be charged by placing it in a fixed position. and enables data transfer.

[0238] The upper camera 2103 and the lower camera 2106 are used to capture images of the surroundings of the robot 2100. The obstacle sensor 2107 detects the obstacles in the robot 210 by using the moving mechanism 2108. When moving forward, the robot can sense whether there are any obstacles in its path. 00 uses an upper camera 2103, a lower camera 2106, and an obstacle sensor 2107. The light-emitting device according to one embodiment of the present invention can recognize the surrounding environment and move safely. It can be used for the display 2105.

[0239] FIG. 7C is a diagram showing an example of a goggle-type display. For example, a housing 5000, a display unit 5001, a speaker 5003, an LED lamp 5004, Connection terminal 5006, sensor 5007 (force, displacement, position, velocity, acceleration, angular velocity, rotation speed, Distance, light, liquid, magnetism, temperature, chemicals, sound, time, hardness, electric field, current, voltage, power, radiation (including those that measure radiation, flow rate, humidity, gradient, vibration, odor, or infrared radiation), The device includes a microphone 5008, a display unit 5002, a support unit 5012, earphones 5013, and the like.

[0240] The light-emitting device of one embodiment of the present invention can be used for the display portion 5001 and the display portion 5002. .

[0241] FIG. 8 shows a configuration of the light-emitting device according to the first and second embodiments in an electric lighting device. The desk lamp shown in FIG. 8 is an example of a desk lamp. The desk lamp shown in FIG. 8 is made up of a housing 2001 and a light source 2002. The lighting device described in Embodiment 3 may be used as the light source 2002.

[0242] FIG. 9 shows a configuration of the light-emitting device according to the first and second embodiments, in which the light-emitting device is mounted in an indoor lighting device 30. The light emitting devices described in the first and second embodiments are used as a signal source. Since it is a highly reliable light-emitting device, it can be used as a highly reliable lighting device. The light-emitting devices described in the first and second embodiments can be made large in area. It can be used as a lighting device for a large area. The light-emitting device is thin and can be used as a thin lighting device. do.

[0243] The light emitting devices according to the first and second embodiments can be used for automobile windshields and windows. The present invention can also be implemented on a flash board. The light emitting device is used in an automobile windshield or dashboard. The display areas 5200 to 5203 are the light-emitting devices described in Embodiments 1 and 2. This is a display area provided using a device.

[0244] In this embodiment, the display area 5200 and the display area 5201 are provided on the windshield of a car. 1 and 2. In the light-emitting device described in the second embodiment, the anode and the cathode are made of light-transmitting electrodes. This allows the display device to be in a see-through state, where the other side can be seen through. Yes, if the display is see-through, it can be installed on the windshield of a car. It can be installed without obstructing the view. When a transistor is provided, an organic transistor made of an organic semiconductor material or a transistor made of an oxide semiconductor may be used. A light-transmitting transistor such as a transistor is preferably used.

[0245] The display area 5202 is the display device described in Embodiments 1 and 2 provided in the pillar portion. The display device is equipped with an optical device. The display area 5202 is equipped with an imaging device mounted on the vehicle body. By projecting images from the steps, it is possible to compensate for the view obstructed by the pillars. Similarly, the display area 5203 provided on the dashboard is not blocked by the vehicle body. By projecting images from an imaging device installed on the outside of the vehicle, blind spots can be eliminated. By projecting images to complement the invisible parts, safety can be improved. This allows you to check for safety more naturally and without any discomfort.

[0246] The display area 5203 also displays navigation information, speedometer, tachometer, odometer, fuel gauge, gear By displaying the status, air conditioning settings, etc., various information can be provided. The display items and layout can be changed as needed to suit the user's preferences. This information can also be provided in display areas 5200 to 5202. The area 5200 to the display area 5203 can also be used as a lighting device.

[0247] 11(A) to 11(C) show a foldable mobile information terminal 9310. 11(A) shows the mobile information terminal 9310 in an unfolded state. The mobile information terminal 9310 is shown in a state in which it is changing from one folded state to the other. FIG. 11C shows the portable information terminal 9310 in a folded state. The foldable design offers excellent portability and a seamless, large viewing area when unfolded. This provides excellent visibility of the display.

[0248] The display panel 9311 is supported by three housings 9315 connected by hinges 9313. The display panel 9311 is a touch panel equipped with a touch sensor (input device). The display panel 9311 may be a display panel (input / output device). The two housings 9315 are bent to open the mobile information terminal 9310. The light-emitting device of one embodiment of the present invention can be reversibly transformed from a folded state to a folded state. It can be used for the display panel 9311.

[0249] 12(A) and (B) show a foldable mobile information terminal 5150. The foldable mobile information terminal 5150 includes a housing 5151, a display area 5152, and a bending portion 515 12(A) shows the mobile information terminal 5150 in an unfolded state. Fig. 5B) shows the portable information terminal 5150 in a folded state. Although it has a large display area 5152, it is compact and highly portable when folded.

[0250] The display area 5152 can be folded in half by the bend 5153. 3 is composed of an expandable member and multiple support members, and when folding, The member is elongated, and the bent portion 5153 has a curvature radius of 2 mm or more, preferably 3 mm or more. It can be folded.

[0251] The display area 5152 is a touch panel (input / output) equipped with a touch sensor (input device). The light-emitting device of one embodiment of the present invention can be used in the display region 5152. Cut. [Example]

[0252] In this example, a light-emitting device 1, which is a light-emitting device according to one embodiment of the present invention, and a comparative light-emitting device The fabrication method and characteristics of comparative light-emitting device 1 are shown below. The first skeleton has transport properties, the second skeleton accepts holes, and the monocyclic and π-electron-deficient complex structure. As an electron transport material having a third skeleton which is a substituted aromatic ring, 2-phenyl-3-{4-[ 10-(3-pyridyl)-9-anthryl]phenyl}quinoxaline (abbreviation: PyA1P Q) in the electron transport layer. 2-{4-[9,10-di(naphthalen-2-yl)-2-anthryl]fluorene instead of PQ phenyl}-1-phenyl-1H-benzimidazole (abbreviation: ZADN) The structural formulas of the materials used in this example are shown below.

[0253] [ka]

[0254] <<Method for producing light-emitting device 1>> First, indium tin oxide containing silicon oxide (ITSO) was sputtered onto a glass substrate. The anode 101 was formed by a film deposition method. The film thickness was 70 nm and the electrode area was 4 mm 2 (2mm x 2mm).

[0255] Next, as a pretreatment for forming a light-emitting device on the substrate, the substrate surface was washed with water. After baking at 00°C for 1 hour, UV ozone treatment was performed for 370 seconds.

[0256] Then, 10 -4 The substrate is placed in a vacuum deposition apparatus whose inside pressure has been reduced to about 100 Pa. After vacuum baking at 170°C for 30 minutes in the heating chamber of the device, the substrate is left for about 30 minutes. Allow to cool.

[0257] Next, the substrate on which the anode 101 is formed is placed in a vacuum chamber so that the surface on which the anode 101 is formed faces downward. The substrate was fixed to a substrate holder installed in the vacuum evaporation device, and evaporation was performed on the anode 101 using resistance heating. By this method, N,N-bis(4-biphenyl)-6-phenyl represented by the above structural formula (i) Benzo[b]naphtho[1,2-d]furan-8-amine (BBABnf) and AL D-MP001Q (Bunseki Kobo Co., Ltd., material serial number: 1S20180314) , 10n so that the weight ratio was 1:0.1 (= BBABnf:ALD-MP001Q). The hole injection layer 111 was formed by co-evaporation of ALD-MP001Q. It is an organic compound having the formula:

[0258] Next, BBABnf was deposited on the hole injection layer 111 to form a first hole transport layer 112-1. After that, a second hole transport layer 112-2 was formed by vapor deposition of a compound represented by the above structural formula (ii). 3,3'-(naphthalene-1,4-diyl)bis(9-phenyl-9H-carbamoyl) PCzN2) was evaporated to a thickness of 10 nm to form a hole transport layer 112. The second hole transport layer 112-2 also functions as an electron blocking layer.

[0259] Next, 9-(1-naphthyl)-10-[4-(2-naphthyl)-2-methyl-1-propanol] represented by the above structural formula (iii) αN-βNPAnth) and the above structural formula (iv) 3,10-bis[N-(9-phenyl-9H-carbazol-2-yl)-N -phenylamino]naphtho[2,3-b;6,7-b']bisbenzofuran (abbreviation: 3, 10PCA2Nbf(IV)-02) in a weight ratio of 1:0.015 (=αN-βNPAn The light-emitting layer was formed by co-evaporating 25 nm of th:3,10PCA2Nbf(IV)-O2). 113 was formed.

[0260] Then, on the light-emitting layer 113, 2-phenyl-3-{4-[1 0-(3-pyridyl)-9-anthryl]phenyl}quinoxaline (abbreviation: PyA1PQ ) and 8-hydroxyquinolinato-lithium (abbreviation: Liq) represented by the above structural formula (vi). ) were co-deposited at a weight ratio of 1:2 (=PyAlPQ:Liq) to a thickness of 12.5 nm. The PyAlPQ:LiQ layer was co-deposited to a thickness of 12.5 nm at a weight ratio of 2:1. A transfer layer 114 was formed.

[0261] After forming the electron transport layer 114, aluminum is evaporated to a thickness of 200 nm. Thus, the cathode 102 was formed, and the light-emitting device 1 of this example was fabricated.

[0262] <<Method for producing comparative light-emitting device 1>> Comparative light-emitting device 1 is a light-emitting device obtained by replacing PyA1PQ in light-emitting device 1 with a compound represented by the above structural formula (vii). 2-{4-[9,10-di(naphthalen-2-yl)-2-anthryl]phenyl The compound was changed to {1H-nyl}-1-phenyl-1H-benzimidazole (abbreviation: ZADN), and the other components were the same as those used in the development. It was fabricated in the same manner as optical device 1.

[0263] The device structures of Light-Emitting Device 1 and Comparative Light-Emitting Device 1 are summarized in the table below.

[0264] [Table 1]

[0265] These light-emitting devices were placed in a nitrogen atmosphere glove box, and the light-emitting devices were placed in a nitrogen atmosphere glove box. The process of sealing with a glass substrate to prevent exposure to heat (sealing material is applied around the element and sealed) After UV treatment at the time of shutdown and heat treatment at 80°C for 1 hour, the light-emitting device 1 and the comparative light-emitting device The initial characteristics and reliability of Device 1 were measured. The measurements were carried out at room temperature.

[0266] The luminance vs. current density characteristics of Light-emitting Device 1 and Comparative Light-emitting Device 1 are shown in Figure 13, and the current efficiency vs. luminance characteristics of Light-emitting Device 1 and Comparative Light-emitting Device 1 are shown in Figure 14. The brightness characteristics are shown in Fig. 14, the brightness-voltage characteristics in Fig. 15, the current-voltage characteristics in Fig. 16, and the external quantum efficiency The efficiency-luminance characteristics are shown in FIG. 17, and the emission spectrum is shown in FIG. 18. Comparative light-emitting device 1: 1000 cd / m 2 The main characteristics of the area are shown in Table 2.

[0267] [Table 2]

[0268] 13 to 18 and Table 2, the light-emitting device 1 according to one embodiment of the present invention has good initial characteristics. It was found that the device was a blue light-emitting device with excellent properties.

[0269] In addition, the current density is 50mA / cm 2 Figure 1 shows a graph showing the change in brightness over time. 19. As shown in FIG. 19, light-emitting device 1, which is a light-emitting device according to one embodiment of the present invention, Compared with the comparative light-emitting device 1, the long-term slope after the initial change has settled is smaller, It was found to be a good light-emitting device with a long lifespan and little degradation over the long term.

[0270] In addition, in the light-emitting device 1 and the comparative light-emitting device 1, the hole injection layer has a hole transport property, and H BBABnf, whose OMO level is between -5.7 eV and -5.4 eV, and BBABnf The electron-transporting layer contains metal, metal salt, and gold. It has Liq, which is an organometallic oxide or an organometallic salt.

[0271] As a result, the luminance of the light-emitting device 1 and the comparative light-emitting device 1 increased after driving, and the initial luminance This indicates that the brightness is higher than that of the initial brightness and then gradually decreases. As a standard, the time until deterioration occurs by 2 to 5% (initial operating life) can be significantly extended.

[0272] As mentioned above, the light-emitting device 1 exhibits a very long lifespan due to its small long-term deterioration. It was found to be a light-emitting device. [Example]

[0273] <Synthesis Example 1> In this synthesis example, a compound that can be used as an electron-transporting material in a light-emitting device according to one embodiment of the present invention was synthesized. The compound 4-{4-[10-(3-pyridyl)-9-anthryl]phenyl}[1] This paper describes the synthesis method of benzofuro[3,2-d]pyrimidine (abbreviation: BfpmPPyA). The structure of BfpmPPyA is shown below.

[0274] [ka]

[0275] Step 1: 4-(4-chlorophenyl)[1]benzofuro[3,2-d]pyrimidine Synthesis of> 4-chloro[1]benzofuro[3,2-d]pyrimidine 2.0 g (9.7 mmol), 4 -Chlorophenylboronic acid 1.8 g (12 mmol), tri(ortho-tolyl)phosphine 0.30 g (0.97 mmol) of ethanol and 2.7 g (19 mmol) of potassium carbonate were added to a three-port flask. To this mixture, 100 mL of toluene, 20 mL of ethanol, and 10 mL of water were added. The mixture was then stirred under reduced pressure to degas it. Then, 0.044 g of palladium (II) acetate was added to the mixture. (0.19 mmol) was added and stirred at 80°C for 6 hours. ) 0.027g (0.097mmol), tri(ortho-tolyl)phosphine 0.20g (0.44 mmol) was added, and the mixture was stirred at 80°C for 2 hours.

[0276] After stirring, water was added to the mixture, the aqueous layer was separated, and the organic layer was filtered. The resulting extract solution was combined with the previous filtrate and washed with water, and the organic layer was extracted with toluene and toluene. The mixture was filtered by gravity, and the filtrate was concentrated. The solid was purified by silica gel column chromatography (developing solvent: toluene: ethyl acetate = 9 The product was purified by the method described in step 1) to obtain 2.5 g of a pale yellow solid in a yield of 92%. The reaction scheme for 1 is shown below.

[0277] [ka]

[0278] Step 2: 4-[4-(4,4,5,5-tetramethyl-[1,3,2]dioxabo Synthesis of (loran-2-yl)phenyl][1]benzofuro[3,2-d]pyrimidine 4-(4-chlorophenyl)[1]benzofuro[3,2-d]pyrimidine 2.5g (8. 9 mmol), bis-pinacolatodiboron 2.7 g (11 mmol), potassium acetate 2. 6 g (27 mmol) of chlorine-containing ammonium hydroxide and 45 mL of xylene were placed in a three-neck flask and the mixture was purged with nitrogen. [1,1'-bis(diphenylphosphino)ferrocene]palladium(II) dichloride Pd(dppf)Cl2 dichloromethane adduct (abbreviation: Pd(dppf)Cl2 · CH2Cl2) 0.3 6 g (0.44 mmol) was added, and the mixture was stirred at 120° C. for 17 hours.

[0279] After stirring, toluene and water were added to the mixture, and the solution was filtered. The aqueous layer was extracted with toluene. The resulting extract and the organic layer were combined and washed with water. The layer was dried over magnesium sulfate, and the mixture was separated by gravity filtration, and the filtrate was concentrated. The obtained solid was dissolved in toluene and filtered through Celite, Florisil, and alumina. The filtrate was concentrated and the resulting solid was added to silica gel. Purified by gel column chromatography (developing solvent toluene: ethyl acetate = 3:1) The target yellow solid was obtained in 2.6 g and 79% yield. is shown below.

[0280] [ka]

[0281] Step 3: 4-{4-[10-(3-pyridyl)-9-anthryl]phenyl}[1 Synthesis of benzofuro[3,2-d]pyrimidine (abbreviation: BfpmPPyA) In a 200 mL three-neck flask, 1.6 g ( 4.8 mmol) and 4-[4-(4,4,5,5-tetramethyl-[1,3,2]dioxane (saborolan-2-yl)-phenyl]-[1]benzofuro[3,2-d]pyrimidine2. 0g (5.3mmol), tri(o-tolyl)phosphine 0.15g (0.48mmol ), 1.3 g (9.6 mmol) of potassium carbonate were added, and the atmosphere in the flask was replaced with nitrogen. Add 50 mL of toluene, 10 mL of ethanol, and 5 mL of water to the mixture and stir under reduced pressure. The mixture was degassed by adding 22 mg (0.096 mmol) of palladium(II) acetate. The mixture was stirred at 80°C for 11 hours under a nitrogen atmosphere. After a predetermined time had elapsed, water was added to the mixture. The precipitated solid was collected by suction filtration and washed with water and methanol. Silica gel column chromatography (developing solvent: toluene: ethyl acetate = 9:1) The solid was purified by filtration and recrystallized from toluene to give 1.4 g (2.8 mm ol) was obtained in a yield of 57%. The synthesis scheme for Step 3 is shown below.

[0282] [ka]

[0283] The obtained solid (1.3 g) was purified by train sublimation. The conditions were a pressure of 3.0 Pa, an argon flow rate of 5 mL / min, and a temperature of 275°C. 1.2 g of BfpmPPyA powder was obtained with a recovery rate of 91%.

[0284] Nuclear magnetic resonance spectroscopy of the obtained compound ( 1 The results of H-NMR are shown in Figure 25(A)(B) ) and the numerical data are shown below. 1 H NMR (CDCl3, 300 MHz): δ = 7. 36-7.44(m,4H), 7.54-7.69(m,4H), 7.73-7.89( m,7H), 8.37(d,J=7.7Hz,1H), 8.77(dd,J=2.2Hz ,0.7Hz,1H), 8.83-8.91(m,3H), 9.36(s,1H). It was found that BfpmPPyA was obtained in this synthesis example. [Example]

[0285] <Synthesis Example 2> In this synthesis example, a compound that can be used as an electron-transporting material in a light-emitting device according to one embodiment of the present invention was synthesized. The compound 2-{4-[10-(3-pyridyl)-9-anthryl]phenyl}dibene This article explains the synthesis method of dibenzo[f,h]quinoxaline (abbreviation: DBqPPyA). The structure of qPPyA is shown below.

[0286] [ka]

[0287] Step 1: 2-{4-[10-(3-pyridyl)-9-anthryl]phenyl}dibenzyl Synthesis of benzo[f,h]quinoxaline (abbreviation: DBqPPyA) In a 150 mL three-neck flask, 1.1 g ( 3.2 mmol) and 2-(4,4,5,5-tetramethyl-1,3,2-dioxaborola 1.5g (3.5mmol)dibenzo[f,h]quinoxaline, tri(o 96 mg (0.32 mmol) of tetrahydrofuran (trimethylsilyl) phosphine, 0.87 g (6 0.3 mmol) was added and the atmosphere in the flask was replaced with nitrogen. 6.0 mL of alcohol and 3.0 mL of water were added, and the mixture was degassed by stirring under reduced pressure. Palladium (II) acetate (14 mg, 0.063 mmol) was added to the mixture, and the mixture was stirred for 8 hours under a nitrogen atmosphere. The mixture was stirred at 0°C for 21 hours. After the specified time had elapsed, water was added to the mixture, and the solid was filtered off with suction. Toluene was added to the obtained solid, and after irradiation with ultrasonic waves, the solid was collected.

[0288] The obtained solid was purified by silica gel column chromatography (developing solvent: chloroform). After purification, the target solid was obtained by recrystallization in a mixed solvent of toluene and ethanol. The synthesis scheme for Step 1 is shown below.

[0289] [ka]

[0290] The obtained solid (0.96 g) was purified by train sublimation. The conditions were a pressure of 2.9 Pa, an argon flow rate of 5 mL / min, and a temperature of 305°C. 0.80 g of DBqPPyA powder was obtained with a recovery rate of 82%.

[0291] Nuclear magnetic resonance spectroscopy of the obtained compound ( 1 The results of H-NMR are shown in Figure 26(A)(B ) and the numerical data are shown below. 1 H NMR (CDCl3, 300 MHz): δ = 7. 38-7.45(m,4H), 7.57-7.69(m,3H), 7.72-7.91( m,9H), 8.63(d,J=8.1Hz,2H), 8.70(d,J=7.7Hz, 2H), 8.77-8.80(m,1H), 8.85(dd,J=1.5Hz,4.8H z,1H), 9.28-9.32(m,1H), 9.49-9.54(m,1H), 9. 57(s,1H). This indicates that DBqPPyA was obtained in this synthesis example. It was. [Example]

[0292] <Synthesis Example 3> In this synthesis example, a compound that can be used as an electron-transporting material in a light-emitting device according to one embodiment of the present invention was synthesized. The compound (9-{4-[10-(3-pyridyl)-9-anthryl]phenyl}naphthyl NfprPPyA The synthesis method is explained below. The structure of NfprPPyA is shown below.

[0293] [ka]

[0294] Step 1: 9-[4-(4,4,5,5-tetramethyl-[1,3,2]dioxabo] (2-yl)-phenyl]naphtho[1',2':4,5]furo[2,3-b]pyra Synthesis of Gin 9-(4-chlorophenyl)-naphtho[1',2':4,5]furo[2,3-b]pyrazine 3.2g (9.7mmol), bis-pinacolatodiboron 3.0g (12mmol), 2.9 g (29 mmol) of potassium acetate and 50 mL of xylene were placed in a three-neck flask and the pressure was reduced. The mixture was degassed by stirring under reduced pressure. sen]palladium(II) dichloromethane adduct (abbreviation: Pd(dppf)Cl2)0. 40 g (0.49 mmol) was added, and the mixture was stirred at 120° C. for 19 hours.

[0295] After a predetermined time, toluene was added to the mixture, and the solution was filtered through Celite, Florisil, The mixture was filtered through alumina (solvent toluene:ethyl acetate=1:1), and the filtrate was concentrated. The obtained solid was purified by silica gel column chromatography (developing solvent: toluene / ethyl acetate The resulting solid was purified by a solvent (ethanol = 3:1) to give a yellow solid. Hexane was added to the resulting solid, and the solid was irradiated with ultrasound. The solid was collected by suction filtration, and the target yellow solid was obtained in a yield of 3.7 g. The synthesis scheme for Step 1 is shown below.

[0296] [ka]

[0297] Step 2: (9-{4-[10-(3-pyridyl)-9-anthryl]phenyl}naphthalene NfprPPyA (futo[1',2':4,5]furo[2,3-b]pyrazine) (abbreviation: NfprPPyA) Synthesis of> In a 200 mL three-neck flask, 1.4 g ( 4.1 mmol) and 3-[4-(4,4,5,5-tetramethyl-[1,3,2]dioxane (saborolan-2-yl)-phenyl]naphtho[1',2':4,5]furo[2,3-b] Pyrazine 1.9 g (4.5 mmol), tri(o-tolyl)phosphine 0.13 g (0. 41 mmol), 1.1 g (8.3 mmol) of potassium carbonate were added, and the flask was purged with nitrogen. To this mixture, 40 mL of toluene, 8 mL of ethanol, and 4 mL of water were added, and the mixture was stirred under reduced pressure. The mixture was degassed by stirring. To this mixture was added 19 mg (0.083 g) of palladium (II) acetate. After adding 10 mmol of ethanol, the mixture was stirred at 80°C for 10 hours under a nitrogen atmosphere. Water was added to the mixture, and the precipitated solid was collected by suction filtration. The obtained solid was purified by silica gel column chromatography (developing solvent: toluene). The compound was purified with a toluene / ethyl acetate ratio of 9:1 and then recrystallized from toluene to obtain the desired compound. The solid was obtained in an amount of 1.3 g (2.4 mmol) with a yield of 58%. The synthesis scheme for Step 2 is as follows: Shown below.

[0298] [ka]

[0299] The obtained solid (1.3 g) was purified by train sublimation. The conditions were a pressure of 3.3 Pa, an argon flow rate of 15 mL / min, and a temperature of 320°C. 0.94 g of NfprPPyA powder was obtained with a recovery rate of 73%.

[0300] Nuclear magnetic resonance spectroscopy of the obtained compound ( 1 The results of H-NMR are shown in Figure 27(A)(B) ) and the numerical data are shown below. 1 H NMR (CDCl3, 300 MHz): δ = 7. 36-7.45(m,4H), 7.56-7.74(m,6H), 7.78-7.91( m,5H), 8.08(d,J=8.1Hz,1H), 8.13(d,J=8.8Hz, 1H), 8.45(d,J=8.4Hz,2H), 8.76-8.78(m,1H), 8 .85(dd,J=4.4Hz,1.5Hz,1H), 9.21(d,J=8.4Hz, 1H), 9.42 (s, 1H). In this synthesis example, NfprPPyA was obtained. It was found that [Example]

[0301] In this example, light-emitting devices 2 to 4, which are light-emitting devices according to one embodiment of the present invention, are shown. The fabrication method and characteristics of the light-emitting devices 2 to 4 are shown. The first skeleton has transport properties, the second skeleton accepts holes, and the monocyclic and π-electron-deficient complex structure. The electron transport material has a third skeleton which is an aromatic ring. Specifically, light-emitting device 2 is 4-[4-[10-(3-pyridyl)-9-anthryl ]phenyl}[1]benzofuro[3,2-d]pyrimidine (abbreviation: BfpmPPyA), Light-emitting device 3 is a 2-{4-[10-(3-pyridyl)-9-anthryl]phenyl}diphenyl The light-emitting device 4 is (9-{ 4-[10-(3-pyridyl)-9-anthryl]phenyl}naphtho[1',2':4, 5]furo[2,3-b]pyrazine) (abbreviation: NfprPPyA). The structural formulas of the materials used are shown below.

[0302] [ka]

[0303] <<Method for producing light-emitting device 2>> First, indium tin oxide containing silicon oxide (ITSO) was sputtered onto a glass substrate. The anode 101 was formed by a film deposition method. The film thickness was 70 nm and the electrode area was 4 mm 2 (2mm x 2mm).

[0304] Next, as a pretreatment for forming a light-emitting device on the substrate, the substrate surface was washed with water. After baking at 00°C for 1 hour, UV ozone treatment was performed for 370 seconds.

[0305] Then, 10 -4 The substrate is placed in a vacuum deposition apparatus whose inside pressure has been reduced to about 100 Pa. After vacuum baking at 170°C for 30 minutes in the heating chamber of the device, the substrate is left for about 30 minutes. Allow to cool.

[0306] Next, the substrate on which the anode 101 is formed is placed in a vacuum chamber so that the surface on which the anode 101 is formed faces downward. The substrate was fixed to a substrate holder installed in the vacuum evaporation device, and evaporation was performed on the anode 101 using resistance heating. By this method, N,N-bis(4-biphenyl)-6-phenyl represented by the above structural formula (i) Benzo[b]naphtho[1,2-d]furan-8-amine (BBABnf) and AL D-MP001Q (Bunseki Kobo Co., Ltd., material serial number: 1S20180314) , 10n so that the weight ratio was 1:0.1 (= BBABnf:ALD-MP001Q). The hole injection layer 111 was formed by co-evaporation of ALD-MP001Q. It is an organic compound having the formula:

[0307] Next, BBABnf was deposited on the hole injection layer 111 to form a first hole transport layer 112-1. After that, a second hole transport layer 112-2 was formed by vapor deposition of a compound represented by the above structural formula (ii). 3,3'-(naphthalene-1,4-diyl)bis(9-phenyl-9H-carbamoyl) PCzN2) was evaporated to a thickness of 10 nm to form a hole transport layer 112. The second hole transport layer 112-2 also functions as an electron blocking layer.

[0308] Next, 9-(1-naphthyl)-10-[4-(2-naphthyl)-2-methyl-1-propanol] represented by the above structural formula (iii) αN-βNPAnth) and the above structural formula (iv) 3,10-bis[N-(9-phenyl-9H-carbazol-2-yl)-N -phenylamino]naphtho[2,3-b;6,7-b']bisbenzofuran (abbreviation: 3, 10PCA2Nbf(IV)-02) in a weight ratio of 1:0.015 (=αN-βNPAn The light-emitting layer was formed by co-evaporating 25 nm of th:3,10PCA2Nbf(IV)-O2). 113 was formed.

[0309] Then, on the light-emitting layer 113, 4-{4-[10-(3 -pyridyl)-9-anthryl]phenyl}[1]benzofuro[3,2-d]pyrimidine (abbreviation: BfpmPPyA) and 8-hydroxyquinolinate represented by the above structural formula (vi) -Lithium (abbreviation: Liq) in a weight ratio of 1:2 (=BfpmPPyA:Liq) The electron transport layer 114 was formed by co-evaporation to a thickness of 25 nm.

[0310] After forming the electron transport layer 114, aluminum is evaporated to a thickness of 200 nm. In this way, the cathode 102 was formed, and the light-emitting device 2 of this example was fabricated.

[0311] <<Method for producing light-emitting device 3>> The light-emitting device 3 is a light-emitting device obtained by replacing BfpmPPyA in the light-emitting device 2 with a compound represented by the above structural formula (ix). 2-{4-[10-(3-pyridyl)-9-anthryl]phenyl}dibenzo[ f,h] The same as light-emitting device 2 except that the quinoxaline (abbreviation: DBqPPyA) was used. It was made.

[0312] <<How to make light-emitting device 4>> The light-emitting device 4 is the same as the light-emitting device 2 except that the electron transport layer 114 is a layer represented by the above structural formula (x). (9-{4-[10-(3-pyridyl)-9-anthryl]phenyl}naphtho[1 ',2':4,5]furo[2,3-b]pyrazine) (abbreviation: NfprPPyA) and Liq and Liq were co-deposited at a weight ratio of 1:2 (=NfprPPyA:Liq) to a thickness of 12.5 nm. Then, 12.5 nm of NfprPPyA was co-deposited at a weight ratio of 2:1 (= NfprPPyA: Liq). The other steps were the same as for the light-emitting device 2.

[0313] The device structures of light-emitting devices 2 to 4 are summarized in the table below.

[0314] [Table 3]

[0315] These light-emitting devices were placed in a nitrogen atmosphere glove box, and the light-emitting devices were placed in a nitrogen atmosphere glove box. The process of sealing with a glass substrate to prevent exposure to heat (sealing material is applied around the element and sealed) After the LEDs were subjected to UV treatment at the time of shutdown and heat treatment at 80°C for 1 hour, light-emitting devices 2 to The initial characteristics and reliability of the device were measured at room temperature.

[0316] The luminance-current density characteristics of light-emitting devices 2 to 4 are shown in FIG. 28, and the current efficiency-luminance characteristics are shown in FIG. The luminance-voltage characteristics are shown in Figure 29, the current-voltage characteristics in Figure 30, and the external quantum efficiency- The luminance characteristics are shown in FIG. 32, and the emission spectrum is shown in FIG. 33. Vice 4 1000cd / m 2 The main characteristics of the area are shown in Table 4.

[0317] [Table 4]

[0318] 28 to 33 and Table 4, light-emitting devices 2 to 31 according to one embodiment of the present invention are shown. 4 was found to be a blue-emitting device with good initial characteristics.

[0319] In addition, the current density is 50mA / cm 2 Figure 1 shows a graph showing the change in brightness over time. 34. As shown in FIG. 34, light-emitting device 2, which is a light-emitting device according to one embodiment of the present invention, The light-emitting device 4 has a small long-term gradient after the initial change has subsided, and is therefore less susceptible to long-term deterioration. It was found that the device had a long life and was light-emitting.

[0320] In addition, the light-emitting devices 2 to 4 each have a hole-injection layer that has hole-transport properties and a HOMO BBABnf, whose level is between -5.7 eV and -5.4 eV, and BBABnf, which accepts electrons The electron transport layer contains metals, metal salts, and metal oxides. It has Liq, which is a compound or an organic metal salt.

[0321] As a result, the luminance of the light-emitting device 3 increases after being driven and then gradually decreases. This means that the time it takes for the initial brightness to deteriorate by 2 to 5% (initial operating life) can be significantly increased.

[0322] (Reference example 1) In this reference example, the HOMO level, LUMO level and electron transfer A method for calculating the mobility will be described.

[0323] HOMO and LUMO levels are calculated based on cyclic voltammetry (CV) measurements. It is possible.

[0324] The measurement device used was an electrochemical analyzer (manufactured by BAS Co., Ltd., model number: ALS model). The solution used in the CV measurements was dehydrated dimethyl ether. Dimethylformamide (DMF) (Aldrich Corporation, 99.8%, Catalog No. 227 05-6) was used, and the supporting electrolyte was tetra-n-butylammonium perchlorate (nB u4NClO4) (Tokyo Chemical Industry Co., Ltd., Catalog No.: T0836) at 100 mmol / The measurement target is dissolved in a solution to a concentration of 2 mmol / L. The working electrode was a platinum electrode (PT, manufactured by BAS Co., Ltd.). E platinum electrode), and as an auxiliary electrode, a platinum electrode (B.A.S. Co., Ltd., VC-3 P The counter electrode (5 cm) was used as the reference electrode, and the Ag / Ag+ electrode (B.A.E. The measurements were carried out at room temperature (20 to 32°C). The scan rate during CV measurement was standardized to 0.1 V / sec. The oxidation potential Ea [V] and reduction potential Ec [V] were measured against the reference electrode. The potential of the reduction wave is defined as the midpoint potential of the reduction wave, and Ec is defined as the midpoint potential of the reduction-oxidation wave. The potential energy of the reference electrode relative to the vacuum level is -4.94 eV. Since it is known that the HOMO level [eV] = -4.94-Ea, the LUMO level [eV ]=-4.94-Ec, calculate the HOMO and LUMO levels. It is possible.

[0325] Electron mobility was measured by impedance spectroscopy (Impedance Spectroscopy) It can be measured using the IS method.

[0326] The carrier mobility of EL materials is measured by the transient photocurrent method (Time-of-flight: T OF method and space-charge-limited current The SCLC method, which uses the IV characteristics of the SCLC (internal voltage: SCLC), has been known for a long time. The TOF method requires a sample with a significantly thicker film than an actual organic EL element. The LC method has the disadvantage that the dependence of carrier mobility on electric field strength cannot be obtained. The thickness of the organic film required for measurement is only a few hundred nanometers, so even a relatively small amount of EL material can be used. It is possible to form a film, and the mobility can be measured at a film thickness close to that of an actual EL element. and the electric field strength dependence of the carrier mobility can also be obtained.

[0327] In the IS method, a minute sinusoidal voltage signal (V = V0 [exp(jωt)]) is applied to the EL element, The current amplitude of the response current signal (I = I0exp[j(ωt+φ)]) and the phase of the input signal The difference is used to calculate the impedance of the EL element (Z=V / I). If the applied voltage is varied from 100 to 1000 V, the impedance will be varied. The components can be separated and measured.

[0328] Here, the admittance Y (=1 / Z), which is the reciprocal of the impedance, is expressed as follows: It can be expressed as conductance G and susceptance B as follows:

[0329]

number

[0330] Furthermore, by the single charge injection model, The following equations (2) and (3) can be calculated: where g (equation (4)) is the differential conductance. In the formula, C is the capacitance, θ is the travel angle, and ω represents the angular frequency. t is the transit time. The analysis uses the current equation, Poisson's equation, and current continuity equation. The equation below is used, ignoring the existence of diffusion current and trap levels.

[0331]

number

[0332] The -ΔB method is a method for calculating mobility from the frequency characteristics of capacitance. The ωΔG method is a method for calculating the mobility from the frequency characteristics of the carrier.

[0333] In practice, first, a measuring element for the material whose electron mobility is to be determined is fabricated. It is designed so that only electrons flow as carriers. The method for calculating the mobility from the measured electrons (-ΔB method) is explained below. show.

[0334] The structure of the measurement element fabricated for this measurement is shown in Figure 20, which consists of an anode 201 and a cathode 2 02, a first layer 210, a second layer 211, and a third layer 212 are provided. The desired material can be used as the material for the second layer 211. An example of measuring the electron mobility of a co-evaporated film with a weight ratio of 1:1 will be described. Typical configuration examples are summarized in the table below.

[0335] [Table 5]

[0336] The current density-voltage curve of the measuring element fabricated with a co-evaporated film of ZADN and Liq as the second layer 211 was The pressure characteristics are shown in Figure 21.

[0337] The impedance measurement was performed by applying a DC voltage in the range of 5.0V to 9.0V while applying an AC voltage. The measurement was carried out under the conditions of a voltage of 70 mV and a frequency of 1 Hz to 3 MHz. The capacitance is calculated from the admittance (equation (1) above), which is the reciprocal of the impedance. The frequency characteristics of the calculated capacitance C at an applied voltage of 7.0 V are shown in FIG.

[0338] The frequency characteristics of capacitance C are the space charge due to carriers injected by a minute voltage signal. This is because the load cannot completely follow the minute AC voltage, and a phase difference occurs in the current. Here, the transit time of the carriers in the film is the time T for the injected carriers to reach the counter electrode. It is defined and expressed by the following equation (5).

[0339]

number

[0340] The negative susceptance change (-ΔB) is the capacitance change -ΔC multiplied by the angular frequency ω (-ωΔ C) The lowest frequency peak frequency f' max (=ω max / 2π) and From equation (3), the relationship between the row time T and equation (6) below is derived.

[0341]

number

[0342] The frequency characteristics of -ΔB calculated from the above measurement (i.e., when the DC voltage is 7.0 V) are shown in Figure 2. 3. The lowest frequency peak frequency f' obtained from Figure 23 max is indicated by the arrow in the figure. did.

[0343] f' obtained from the above measurements and analysis max From this, the travel time T can be calculated (the above formula ( 6)) From the above formula (5), calculate the electron mobility at a voltage of 7.0 V in this case. By performing similar measurements at DC voltages ranging from 5.0V to 9.0V, Since the electron mobility at (electric field strength) can be calculated, the dependence of the mobility on the electric field strength can also be measured.

[0344] Using the above calculation method, the electric field strength dependence of the electron mobility finally obtained for each organic compound was The square root of the electric field strength [V / cm] read from the figure is 600 [V / cm]. 1 / 2 The electron mobility values ​​at these times are shown in Table 6.

[0345] [Table 6]

[0346] As described above, it is possible to calculate the electron mobility. , Takayuki Okachi et al. ”Japanese Journal of Applied Physics” Vol. 47, No. 12, 2008, See pp. 8965-8972.

[0347] (Reference example 2) <Synthesis Example 4> In this Reference Example, the 2-phenyl-3-{4-[10-(3-pyridinyl)methyl]-2-phenyl-4-[10-(3-pyridinyl)methyl]-2-phenyl-3-{ ... Regarding the synthesis of {9-anthryl}-9-phenyl}quinoxaline (abbreviation: PyA1PQ) The structure of PyA1PQ is shown below.

[0348] [ka]

[0349] In a 50 mL three-neck flask, add 0.74 g (2 0.2 mmol), tri(ortho-tolyl)phosphine 0.26 g (0.85 mmol), 4-(3-phenylquinoxalin-2-yl)phenylboronic acid 0.73g (2.3mm ol), potassium carbonate aqueous solution 1.3 g (9.0 mmol), ethylene glycol dimethyl 40 mL of ether (DME) and 4.4 mL of water were added. The mixture was stirred under reduced pressure. The flask was degassed by filtration and the atmosphere inside was replaced with nitrogen.

[0350] Add 65 mg (0.29 mmol) of palladium (II) acetate to the mixture in the flask. The mixture was stirred at 80°C for 11 hours under a nitrogen stream. After stirring, water was added to the mixture in the flask, and The resulting extract was washed with saturated saline and dried over magnesium sulfate. This was filtered by gravity, and the filtrate was concentrated to give an oily substance. Column chromatography (chloroform) and (toluene:ethyl acetate=5:1) twice The product was purified and recrystallized from toluene / hexane to give the desired yellow solid in an amount of 0.43 g and a yield of 36%. The synthesis scheme is shown below.

[0351] [ka]

[0352] The resulting yellow solid (0.44 g) was purified by train sublimation. The purification was carried out at a pressure of 10 Pa, an argon flow rate of 5.0 mL / min, and 260°C for 18 hours. After purification by sublimation, 0.35 g of the target yellow solid was obtained with a recovery rate of 79%.

[0353] The yellow solid obtained in the above reaction was analyzed by nuclear magnetic resonance spectroscopy ( 1 H-NMR analysis results From these results, in this example, PyA1PQ represented by the above structural formula It was found that the following was obtained.

[0354] 1 H NMR(CDCl3,300MHz):δ=7.37-7.50(m,9H), 7 .56-7.78(m,9H), 7.82-7.86(m,3H), 8.24-8.30 (m,2H), 8.75(dd,J=1.8Hz,0.9Hz,1H), 8.84(dd ,J=4.8Hz,1.8Hz,1H). [Explanation of symbols]

[0355] 101 Anode 102 Cathode 103 EL layer 111 Hole injection layer 112 Hole transport layer 112-1 First hole transport layer 112-2 Second hole transport layer 113 Light-emitting layer 114 Electron transport layer 114-1 First electron transport layer 114-2 Second electron transport layer 115 Electron injection layer 201 Anode 202 Cathode 210 First Layer 211 Second Layer 212 Third Layer 400 boards 401 Anode 403 EL layer 404 Cathode 405 Sealing material 406 Sealing material 407 Sealing substrate 412 Pad 420 IC chip 501 Anode 502 Cathode 511 First Light Emitting Unit 512 Second Light Emitting Unit 513 Charge generation layer 601 Driver circuit section (source line driver circuit) 602 Pixel section 603 Drive circuit section (gate line drive circuit) 604 Sealing substrate 605 Sealing material 607 Space 608 Wiring 609 FPC (Flexible Printed Circuit) 610 Element substrate 611 Switching FET 612 Current control FET 613 Anode 614 Insulators 616 EL layer 617 Cathode 618 Light-emitting devices 1001 board 1002 Undercoat insulating film 1003 Gate insulating film 1006 Gate electrode 1007 Gate electrode 1008 gate electrode 1020 First interlayer insulating film 1021 Second interlayer insulating film 1022 Electrode 1024W anode 1024R Anode 1024G anode 1024B Anode 1025 Bulkhead 1028 EL layer 1029 Cathode 1031 Sealing substrate 1032 Sealing material 1033 Transparent substrate 1034R Red color layer 1034G Green color layer 1034B Blue color layer 1035 Black Matrix 1036 Overcoat layer 1037 Third interlayer insulating film 1040 pixel section 1041 Drive circuit section 1042 Periphery 2001 Case 2002 light source 2100 Robot 2110 Arithmetic equipment 2101 Illuminance sensor 2102 Microphone 2103 Upper Camera 2104 Speaker 2105 Display 2106 Lower Camera 2107 Obstacle Sensor 2108 Moving mechanism 3001 Lighting equipment 5000 cabinets 5001 Display section 5002 Display section 5003 Speaker 5004 LED lamp 5006 Connection terminal 5007 Sensor 5008 Microphone 5012 Support part 5013 Earphones 5100 Cleaning Robot 5101 Display 5102 Camera 5103 Brush 5104 Operation button 5150 Personal Digital Assistant 5151 Case 5152 Display area 5153 Bend 5120 Garbage 5200 display area 5201 Display area 5202 Display area 5203 Display area 7101 Housing 7103 Display section 7105 Stand 7107 Display section 7109 Operation key 7110 Remote control device 7201 Main unit 7202 Case 7203 Display section 7204 keyboard 7205 External connection port 7206 Pointing Device 7210 Second display unit 7401 Housing 7402 Display section 7403 Operation button 7404 External connection port 7405 Speaker 7406 Microphone 9310 Mobile Information Terminal 9311 Display Panel 9313 Hinge 9315 Housing

Claims

1. an anode, a cathode, a light-emitting layer, and an electron transport layer; the electron transport layer comprises an electron transport material; the electron transport material is an organic compound having a first skeleton, a second skeleton, and a third skeleton; the first skeleton is any one of a quinoxaline ring, a dibenzo[f,h]quinoxaline ring, and a [1]benzofuro[3,2-d]pyrimidine ring; the second skeleton is an anthracene ring, the third skeleton is a pyridine ring, the first skeleton is bonded to the second skeleton via a phenylene group; The third scaffold is directly bonded to the second scaffold.

2. an anode, a cathode, a hole injection layer, a light emitting layer, and an electron transport layer; the hole injection layer is located between the anode and the light-emitting layer, the electron transport layer is located between the light-emitting layer and the cathode; the hole injection layer comprises a hole transport material and an acceptor material; the electron transport layer comprises an electron transport material and a metal, a metal salt, a metal oxide, or an organic metal salt; the hole transport material is an organic compound that has hole transport properties and has a HOMO level of −5.7 eV or more and −5.4 eV or less; the acceptor material is a substance that exhibits electron accepting properties to the hole transport material, the electron transport material is an organic compound having a first skeleton, a second skeleton, and a third skeleton; the first skeleton is any one of a quinoxaline ring, a dibenzo[f,h]quinoxaline ring, and a [1]benzofuro[3,2-d]pyrimidine ring; the second skeleton is an anthracene ring, the third skeleton is a pyridine ring, the first skeleton is bonded to the second skeleton via a phenylene group; The third scaffold is directly bonded to the second scaffold.

3. In claim 2, A light-emitting device wherein the acceptor material is an organic compound.

4. In any one of claims 1 to 3, A light-emitting device, wherein the third skeleton is bonded to the second skeleton such that a nitrogen atom is at the beta position relative to the carbon atom bonded to the second skeleton.

5. In any one of claims 1 to 4, The light-emitting device, wherein the electron transport layer further comprises a metal, a metal salt, a metal oxide, or an organometallic salt.

6. In claim 5, A light-emitting device wherein the metal, metal salt, metal oxide, or organometallic salt is a metal complex with an alkali metal or alkaline earth metal.

7. In claim 5, A light-emitting device, wherein the metal, metal salt, metal oxide, or organometallic salt is a metal complex having a nitrogen- and oxygen-containing ligand and an alkali metal or alkaline earth metal.

8. In claim 5, The light-emitting device, wherein the metal, metal salt, metal oxide, or organometallic salt is a metal complex having a ligand containing an 8-hydroxyquinolinato structure and a monovalent metal ion.

9. In any one of claims 1 to 8, The light-emitting device wherein the electron transport layer is in contact with the cathode.

10. In any one of claims 1 to 9, the light-emitting layer includes a host material and a light-emitting material; The light-emitting material is a light-emitting device that emits blue fluorescence.

11. A light-emitting apparatus comprising the light-emitting device according to claim 1 and a transistor or a substrate.

12. 11. An electronic device comprising: the light-emitting device according to claim 1; and a sensor, an operation button, a speaker, or a microphone.

13. A lighting device comprising: the light-emitting device according to claim 1; and a housing.

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