Light-emitting devices

Abstract

Provided is a new light-emitting device that has excellent convenience, usefulness, and reliability. This light emitting device comprises a first electrode, a second electrode, a first unit, and a first layer. The first unit is sandwiched between the first electrode and the second electrode, and is provided with a second layer, a third layer, and a fourth layer. The second layer is sandwiched between the third layer and the fourth layer, and includes a luminescent material. The fourth layer is sandwiched between the second layer and the second electrode, and includes a first organic compound. The first organic compound comprises a π-electron deficient heteroaromatic ring skeleton and a π-electron rich heteroaromatic ring skeleton, and has a HOMO level in the range of -6.0 to -5.6 eV. The first layer is sandwiched between the first electrode and the first unit, is in contact with the first electrode, and includes a second organic compound and a third organic compound.

Description

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

[0001] One embodiment of the present invention relates to a light-emitting device, a light-emitting apparatus, a display device, an electronic device, or a lighting device.

[0002] Note that one embodiment of the present invention is not limited to the above technical field. The technical field of one embodiment of the invention disclosed in this specification and the like relates to an object, a method, or a manufacturing method. Alternatively, one embodiment of the present invention relates to a process, a machine, manufacture, or a composition of matter. Therefore, more specifically, examples of the technical field of one embodiment of the present invention disclosed in this specification include a semiconductor device, a display device, a light-emitting device, a power storage device, a memory device, a driving method thereof, or a manufacturing method thereof.

[0003] Light-emitting devices (organic EL devices) that utilize electroluminescence (EL) using organic compounds are becoming increasingly practical. The basic structure of these light-emitting devices is a pair of electrodes sandwiching an organic compound layer (EL layer) containing a light-emitting material. By applying a voltage to this element, carriers (holes and electrons) are injected, and the recombination energy of the carriers is utilized to emit light from the light-emitting material.

[0004] Since such light-emitting devices are self-luminous, when used as display pixels, they offer advantages such as higher visibility than liquid crystals and no need for backlighting, making them suitable for flat panel display elements. Another major advantage of displays using such light-emitting devices is that they can be fabricated to be thin and lightweight. Another feature is their extremely fast response time.

[0005] Furthermore, these light-emitting devices can have a continuous light-emitting layer formed two-dimensionally, enabling them to emit light in a planar form. This is a feature that is difficult to obtain with point light sources such as incandescent lamps and LEDs, or linear light sources such as fluorescent lamps, making them highly useful as planar light sources for lighting applications.

[0006] Displays and lighting devices using such light-emitting devices are suitable for a variety of electronic devices, but research and development is ongoing to find light-emitting devices with even better characteristics.

[0007] For example, the EL layer includes, in order from the anode side, a first layer, a second layer, a third layer, a light-emitting layer, and a fourth layer, the first layer includes a first organic compound and a second organic compound, the fourth layer includes a seventh organic compound, the first organic compound exhibits electron accepting properties with respect to the second organic compound, the second organic compound has a highest occupied molecular orbital (HOMO) level of −5.7 eV or more and −5.2 eV or less, and the seventh organic compound has an electron mobility of 1×10 when the square root of the electric field strength [V / cm] is 600. −７ cm ２ / Vs or more 5×10 −５ cm ２ A light-emitting device having a capacitance of 1 / Vs or less is known (Patent Document 1).

[0008] JP 2020-96171 A

[0009] An object of one embodiment of the present invention is to provide a novel light-emitting device with excellent convenience, usefulness, or reliability.An object of one embodiment of the present invention is to provide a novel light-emitting device with excellent convenience, usefulness, or reliability.An object of one embodiment of the present invention is to provide a novel display device with excellent convenience, usefulness, or reliability.An object of one embodiment of the present invention is to provide a novel electronic device with excellent convenience, usefulness, or reliability.An object of one embodiment of the present invention is to provide a novel lighting device with excellent convenience, usefulness, or reliability.An object of one embodiment of the present invention is to provide a novel light-emitting device, a novel light-emitting device, a novel display device, a novel electronic device, or a novel lighting device.

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

[0011] (1) One embodiment of the present invention is a light-emitting device including a first electrode, a second electrode, a first unit, and a first layer.

[0012] The first unit is sandwiched between the first electrode and the second electrode, and the first unit comprises a second layer, a third layer, and a fourth layer.

[0013] The second layer is sandwiched between the third and fourth layers, the second layer including a light-emitting material.

[0014] The fourth layer is sandwiched between the second layer and the second electrode, and the fourth layer includes a first organic compound, the first organic compound having a π-electron-deficient heteroaromatic ring skeleton and a π-electron-rich heteroaromatic ring skeleton.

[0015] The first layer is sandwiched between the first electrode and the first unit, and is in contact with the first electrode. The first layer also includes a second organic compound and a third organic compound, and the third organic compound has electron accepting properties with respect to the second organic compound.

[0016] The first layer is 1 x 10 ４ [Ω・cm] or more 1×10 ７ It has a resistivity of [Ω·cm] or less.

[0017] (2) Another embodiment of the present invention is the light-emitting device described above, in which the first organic compound has a first HOMO level in the range of −6.0 eV to −5.6 eV.

[0018] (3) Another embodiment of the present invention is the light-emitting device, wherein the first organic compound has a diazine skeleton and a π-electron-rich heteroaromatic ring skeleton.

[0019] This makes it possible to facilitate the transfer of electrons from the second electrode to the second layer.

[0020] (4) Another embodiment of the present invention is the light-emitting device, in which the first organic compound includes a π-electron-deficient heteroaromatic ring skeleton and a carbazole skeleton.

[0021] This facilitates the movement of holes from the second layer to the fourth layer.

[0022] (5) Another embodiment of the present invention is the above light-emitting device, in which the first organic compound is represented by General Formula (G1):

[0023]

[0024] In the general formula (G1), D represents a substituted or unsubstituted quinoxalinyl group, E represents a substituted or unsubstituted carbazolyl group, and Ar represents a substituted or unsubstituted arylene group having 6 to 13 carbon atoms constituting the ring.

[0025] This facilitates the transfer of electrons from the second electrode to the second layer. It also facilitates the transfer of holes from the second layer to the fourth layer. It also reduces the accumulation of holes between the second layer and the fourth layer. It also reduces the accumulation of holes at the interface between the second layer and the fourth layer. As a result, a novel light-emitting device with excellent convenience, usefulness, and reliability can be provided.

[0026] (6) Another embodiment of the present invention is the light-emitting device, in which the third organic compound has a lowest unoccupied molecular orbital (LUMO) level of −5.0 eV or less, and the second organic compound has a second HOMO level in the range of −5.7 eV to −5.3 eV.

[0027] (7) In one embodiment of the present invention, when the square root of the electric field strength [V / cm] is 600, the hole mobility of the second organic compound is 1×10 −３ The light-emitting device has a luminance of 0.015 Å / cm / Vs or less.

[0028] (8) In one embodiment of the present invention, the first layer is 5×10 ４ [Ω・cm] or more 1×10 ７ The light-emitting device has a resistivity of Ω·cm or less.

[0029] (9) In one embodiment of the present invention, the first layer has a surface roughness of 1×10 ５ [Ω・cm] or more 1×10 ７ The light-emitting device has a resistivity of Ω·cm or less.

[0030] This facilitates the injection of holes from the first electrode to the first unit. It also appropriately suppresses holes from flowing through the first layer. It also suppresses the phenomenon of unintended hole flow into an adjacent light-emitting device. It also suppresses crosstalk, which is the unintended operation of adjacent light-emitting devices. As a result, it is possible to provide a novel light-emitting device that is highly convenient and reliable.

[0031] (10) Another embodiment of the present invention is the light-emitting device described above, wherein the third layer is sandwiched between the first layer and the second layer and is in contact with the first layer.

[0032] In the above light-emitting device, the third layer includes a fourth organic compound, and the fourth organic compound has a third HOMO level, and the third HOMO level is in the range of −0.2 eV to 0 eV with respect to the second HOMO level.

[0033] (11) Another embodiment of the present invention is a display device including a first light-emitting device and a second light-emitting device.

[0034] The first light emitting device has the above configuration, and the second light emitting device is adjacent to the first light emitting device.

[0035] The second light emitting device comprises a third electrode and a fifth layer, the third electrode comprising a first gap between the third electrode and the first electrode.

[0036] The fifth layer is sandwiched between the third electrode and the second electrode, the fifth layer is in contact with the third electrode, the fifth layer includes a second organic compound, and the fifth layer has a second gap between itself and the first layer, the second gap overlapping the first gap.

[0037] (12) Another embodiment of the present invention is a light-emitting device including the above-described light-emitting device and a transistor or a substrate.

[0038] (13) Another embodiment of the present invention is a display device including the above-described light-emitting device and a transistor or a substrate.

[0039] (14) Another embodiment of the present invention is a lighting device including the above-described light-emitting device and a housing.

[0040] (15) Another embodiment of the present invention is an electronic device including the above display device, a sensor, an operation button, a speaker, or a microphone.

[0041] In the drawings accompanying this specification, components are classified by function and shown as independent blocks in block diagrams, but in reality, it is difficult to completely separate components by function, and one component may be involved in multiple functions.

[0042] In this specification, the term "light-emitting device" includes an image display device using a light-emitting device. The term "light-emitting device" may also include a module in which a connector, such as an anisotropic conductive film or a TCP (Tape Carrier Package), is attached to a light-emitting device, a module in which a printed wiring board is provided at the end of a TCP, or a module in which an IC (integrated circuit) is directly mounted on a light-emitting device using a COG (Chip On Glass) method. Furthermore, lighting fixtures and the like may have a light-emitting device.

[0043] According to one embodiment of the present invention, a novel light-emitting device with excellent convenience, usefulness, or reliability can be provided. Alternatively, a novel light-emitting device with excellent convenience, usefulness, or reliability can be provided. Alternatively, a novel display device with excellent convenience, usefulness, or reliability can be provided. Alternatively, a novel electronic device with excellent convenience, usefulness, or reliability can be provided. Alternatively, a novel lighting device with excellent convenience, usefulness, or reliability can be provided. Alternatively, a novel light-emitting device, a novel light-emitting device, a novel display device, a novel electronic device, or a novel lighting device can be provided.

[0044] Note that the description of these effects does not preclude the existence of other effects. Note that one embodiment of the present invention does not necessarily have all of these effects. Note that effects other than these will become apparent from the description in the specification, drawings, claims, etc., and it is possible to extract other effects from the description in the specification, drawings, claims, etc.

[0045] FIGS. 1A and 1B are diagrams illustrating a configuration of a light-emitting device according to an embodiment. FIGS. 2A and 2B are diagrams illustrating a configuration of a light-emitting device according to an embodiment. FIGS. 3A and 3B are diagrams illustrating a configuration of a functional panel according to an embodiment. FIGS. 4A and 4B are diagrams illustrating a configuration of a functional panel according to an embodiment. FIG. 5 is a diagram illustrating a configuration of a functional panel according to an embodiment. FIGS. 6A and 6B are conceptual diagrams of an active matrix light-emitting device. FIGS. 7A and 7B are conceptual diagrams of an active matrix light-emitting device. FIG. 8 is a conceptual diagram of an active matrix light-emitting device. FIGS. 9A and 9B are conceptual diagrams of a passive matrix light-emitting device. FIGS. 10A and 10B are diagrams illustrating a lighting device. FIGS. 11A to 11D are diagrams illustrating electronic devices. FIGS. 12A to 12C are diagrams illustrating electronic devices. FIG. 13 is a diagram illustrating a lighting device. FIG. 14 is a diagram illustrating a lighting device. FIG. 15 is a diagram illustrating an in-vehicle display device and a lighting device. FIGS. 16A to 16C are diagrams illustrating electronic devices. 17A and 17B are diagrams illustrating the configuration of a light-emitting device according to an example. FIG. 18 is a diagram illustrating the current density-luminance characteristics of a light-emitting device according to an example. FIG. 19 is a diagram illustrating the luminance-current efficiency characteristics of a light-emitting device according to an example. FIG. 20 is a diagram illustrating the voltage-luminance characteristics of a light-emitting device according to an example. FIG. 21 is a diagram illustrating the voltage-current characteristics of a light-emitting device according to an example. FIG. 22 is a diagram illustrating the luminance-blue index characteristics of a light-emitting device according to an example. FIG. 23 is a diagram illustrating the emission spectrum of a light-emitting device according to an example. FIG. 24 is a diagram illustrating the change over time in normalized luminance of a light-emitting device according to an example.

[0046] A light-emitting device according to one embodiment of the present invention includes a first electrode, a second electrode, a first unit, and a first layer. The first unit is sandwiched between the first electrode and the second electrode, and includes a second layer, a third layer, and a fourth layer. The second layer is sandwiched between the third layer and the fourth layer, and the second layer includes a light-emitting material. The fourth layer is sandwiched between the second layer and the second electrode, and includes a first organic compound, the first organic compound including a π-electron-deficient heteroaromatic ring skeleton and a π-electron-rich heteroaromatic ring skeleton, and having a HOMO level in the range of −6.0 eV to −5.6 eV. The first layer is sandwiched between the first electrode and the first unit, and the first layer is in contact with the first electrode. The first layer includes a second organic compound and a third organic compound, the third organic compound has an electron accepting property with respect to the second organic compound, and the resistivity of the first layer is 1×10 ４ [Ω・cm] or more 1×10 ７ [Ω·cm] or less.

[0047] When the first organic compound has, for example, a diazine skeleton and a π-electron-rich heteroaromatic ring skeleton, electrons can be easily transferred from the second electrode to the second layer. Additionally, when the first organic compound has a π-electron-deficient heteroaromatic ring skeleton and a carbazole skeleton and has a HOMO level in the range of −6.0 eV to −5.6 eV, holes can be easily transferred from the second layer to the fourth layer. Furthermore, accumulation of holes at the interface between the second layer and the fourth layer can be reduced, thereby suppressing deterioration of the organic compound. As a result, a novel light-emitting device with excellent convenience, usefulness, and reliability can be provided.

[0048] Furthermore, the high resistivity of the first layer is expected to have the effect of suppressing crosstalk. However, if the resistivity is too high, hole injection is hindered, and a light-emitting device with a long life cannot be obtained. Therefore, the resistivity of the material constituting the first layer is set to 1×10 ４ [Ω・cm] or more 1×10 ７ [Ω·cm] or less. Furthermore, the light emitting device has a long life, and a light emitting apparatus using the light emitting device has reduced crosstalk and good display quality.

[0049] The embodiments will be described in detail with reference to the drawings. However, the present invention is not limited to the following description, and it will be readily understood by those skilled in the art that various changes in form and details can be made without departing from the spirit and scope of the present invention. Therefore, the present invention should not be interpreted as being limited to the description of the embodiments shown below. In the configuration of the invention described below, the same parts or parts having similar functions will be denoted by the same reference numerals in different drawings, and repeated explanations will be omitted.

[0050] Embodiment 1 In this embodiment, a structure of a light-emitting device 550 of one embodiment of the present invention will be described with reference to FIGS.

[0051] FIG. 1A is a cross-sectional view of a light-emitting device 550 of one embodiment of the present invention, and FIG. 1B illustrates a structure of the light-emitting device 550 of one embodiment of the present invention.

[0052] <Structure Example of Light-Emitting Device 550> The light-emitting device described in this embodiment includes an electrode 551, an electrode 552, a unit 103, and a layer 104 (see FIG. 1A). The unit 103 is sandwiched between the electrode 551 and the electrode 552.

[0053] <Structure Example of Electrode 551> For example, a conductive material can be used for the electrode 551. Specifically, the electrode 551 can be formed using a single layer or a stacked layer of a film containing a metal, an alloy, or a conductive compound.

[0054] For example, a film that efficiently reflects light can be used for the electrode 551. Specifically, the electrode 551 can be a film of a metal such as an alloy containing silver and copper, an alloy containing silver and palladium, or aluminum.

[0055] Furthermore, for example, a metal film that transmits part of the light and reflects the other part of the light can be used for the electrode 551. This allows a microresonator structure (microcavity) to be provided in the light-emitting device 150. Alternatively, light of a specific wavelength can be extracted more efficiently than other light. Alternatively, light with a narrow spectral half-width can be extracted. Alternatively, light of a vivid color can be extracted.

[0056] Furthermore, for example, a film that transmits visible light can be used for the electrode 551. Specifically, a single layer or stacked layer of a metal film, an alloy film, a conductive oxide film, or the like that is thin enough to transmit light can be used for the electrode 551.

[0057] In particular, a material having a work function of 4.0 eV or more can be suitably used for the electrode 551 .

[0058] For example, a conductive oxide containing indium can be used for the electrode 551. Specifically, indium oxide, indium oxide-tin oxide (abbreviation: ITO), indium oxide-tin oxide containing silicon or silicon oxide (abbreviation: ITSO), indium oxide-zinc oxide, indium oxide containing tungsten oxide and zinc oxide (IWZO), or the like can be used.

[0059] Alternatively, for example, a conductive oxide containing zinc can be used, such as zinc oxide, zinc oxide doped with gallium, or zinc oxide doped with aluminum.

[0060] Alternatively, for example, gold (Au), platinum (Pt), nickel (Ni), tungsten (W), chromium (Cr), molybdenum (Mo), iron (Fe), cobalt (Co), copper (Cu), palladium (Pd), or a nitride of a metal material (e.g., titanium nitride) can be used. Alternatively, graphene can be used.

[0061] <Configuration Example of Unit 103> The unit 103 includes a layer 111, a layer 112, and a layer 113 (see FIG. 1A). The unit 103 has a function of emitting light EL1.

[0062] For example, a layer selected from functional layers such as a light-emitting layer, a hole-transporting layer, an electron-transporting layer, and a carrier-blocking layer can be used in unit 103. Also, a layer selected from functional layers such as a hole-injecting layer, an electron-injecting layer, an exciton-blocking layer, and a charge-generating layer can be used in unit 103.

[0063] <<Structure Example 1 of Layer 111>> The layer 111 is sandwiched between the layer 112 and the layer 113, and contains a light-emitting material. A light-emitting material and a host material can be used for the layer 111. The layer 111 can also be referred to as a light-emitting layer. Note that a structure in which the layer 111 is disposed in a region where holes and electrons recombine is preferable. This allows energy generated by carrier recombination to be efficiently converted into light and emitted.

[0064] It is also preferable to arrange the layer 111 away from metals used for the electrodes, etc. This makes it possible to suppress the quenching phenomenon caused by the metals used for the electrodes, etc.

[0065] Furthermore, it is preferable to adjust the distance from a reflective electrode or the like to the layer 111 and place the layer 111 at an appropriate position according to the emission wavelength. This makes it possible to enhance the amplitude by utilizing the interference phenomenon between the light reflected by the electrode or the like and the light emitted by the layer 111. It is also possible to enhance the light of a specific wavelength and narrow the light spectrum. It is also possible to obtain a vivid emission color with high intensity. In other words, a microresonator structure (microcavity) can be formed by placing the layer 111 at an appropriate position between the electrodes or the like.

[0066] For example, the light-emitting material can be a fluorescent material, a phosphorescent material, or a material exhibiting thermally activated delayed fluorescence (TADF) (also called a TADF material), which allows the energy generated by carrier recombination to be emitted from the light-emitting material as light EL1 (see FIG. 1A).

[0067] [Fluorescent Light-Emitting Substance] A fluorescent light-emitting substance can be used for the layer 111. For example, the fluorescent light-emitting substances exemplified below can be used for the layer 111. Note that the fluorescent light-emitting substance is not limited thereto, and various known fluorescent light-emitting substances can be used for the layer 111.

[0068] Specifically, 5,6-bis[4-(10-phenyl-9-anthryl)phenyl]-2,2′-bipyridine (abbreviation: PAP2BPy), 5,6-bis[4′-(10-phenyl-9-anthryl)biphenyl-4-yl]-2,2′-bipyridine (abbreviation: PAPP2BPy), N,N′-diphenyl-N,N′-bis[4-(9-phenyl-9H-fluoren-9-yl)phenyl]pyrene-1,6-diamine (abbreviation: 1,6FLPAPrn), N,N′-bis(3-methylphenyl)-N,N′-bis[3-(9-phenyl)phenyl]pyrene-1,6-diamine (abbreviation: 1,6FLPAPrn), N,N'-bis[4-(9H-carbazol-9-yl)phenyl]pyrene-1,6-diamine (abbreviation: 1,6mMemFLPAPrn), N,N'-bis[4-(9H-carbazol-9-yl)phenyl]-N,N'-diphenylstilbene-4,4'-diamine (abbreviation: YGA2S), 4-(9H-carbazol-9-yl)-4'-(10-phenyl-9-anthryl)triphenylamine (abbreviation: YGAPA), 4-(9H-carbazol-9-yl)-4'-(9,10-diphenyl-2-anthryl)triphenylamine (abbreviation: YGAPA), : 2YGAPPA), N,9-diphenyl-N-[4-(10-phenyl-9-anthryl)phenyl]-9H-carbazol-3-amine (abbreviation: PCAPA), perylene, 2,5,8,11-tetra(tert-butyl)perylene (abbreviation: TBP), 4-(10-phenyl-9-anthryl)-4'-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBAPA), N,N''-(2-tert-butylanthracene-9,10-diyldi-4,1-phenylene)bis[N,N',N '-triphenyl-1,4-phenylenediamine] (abbreviation: DPABPA), N,9-diphenyl-N-[4-(9,10-diphenyl-2-anthryl)phenyl]-9H-carbazol-3-amine (abbreviation: 2PCAPPA), N,N'-(pyrene-1,6-diyl)bis[(6,N-diphenylbenzo[b]naphtho[1,2-d]furan)-8-amine] (abbreviation: 1,6BnfAPrn-03), 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), 3,10-bis[N-(dibenzofuran-3-yl)-N-phenylamino]naphtho[2,3-b;6,7-b']bisbenzofuran (abbreviation: 3,10FrA2Nbf(IV)-02), etc. can be used.

[0069] In particular, condensed aromatic diamine compounds typified by pyrenediamine compounds such as 1,6FLPAPrn, 1,6mMemFLPAPrn, and 1,6BnfAPrn-03 are preferred because they have high hole trapping properties and are excellent in luminous efficiency or reliability.

[0070] Also, N-[4-(9,10-diphenyl-2-anthryl)phenyl]-N,N',N'-triphenyl-1,4-phenylenediamine (abbreviation: 2DPAPPA), N,N,N',N',N'',N'',N''',N'''-octaphenyldibenzo[g,p]chrysene-2,7,10,15-tetraamine (abbreviation: DBC1), Coumarin 30, N-(9,10-diphenyl-2-anthryl)-N,9-diphenyl-9H-carbazol-3-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 N-[9,10-bis(1,1′-biphenyl-2-yl)-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′-triphenyl-1,4-phenylenediamine (abbreviation: 2DPABPhA), 9,10-bis(1,1′-biphenyl-2-yl)-N-[4-(9H-carbazol-9-yl)phenyl]-N-phenylanthracen-2-amine (abbreviation: 2YGABPhA), N,N,9-triphenylanthracen-9-amine (abbreviation: DPhAPhA), coumarin 545T, N,N′-diphenylquinacridone (abbreviation: DPQd), rubrene, 5,12-bis(1,1′-biphenyl-4-yl)-6,11-diphenyltetracene (abbreviation: BPT), and the like can be used.

[0071] Further, 2-(2-{2-[4-(dimethylamino)phenyl]ethenyl}-6-methyl-4H-pyran-4-ylidene)propanedinitrile (abbreviation: DCM1), 2-{2-methyl-6-[2-(2,3,6,7-tetrahydro-1H,5H-benzo[ij]quinolizin-9-yl)ethenyl]-4H-pyran-4-ylidene}propanedinitrile (abbreviation: DCM2), N,N,N',N'-tetrakis(2-methyl-6-[2-(2,3,6,7-tetrahydro-1H,5H-benzo[ij]quinolizin-9-yl)ethenyl]-4H-pyran-4-ylidene)propanedinitrile (abbreviation: DCM3), (4-methylphenyl)tetracene-5,11-diamine (abbreviation: p-mPhTD), 7,14-diphenyl-N,N,N',N'-tetrakis(4-methylphenyl)acenaphtho[1,2-a]fluoranthene-3,10-diamine (abbreviation: p-mPhAFD), 2-{2-isopropyl-6-[2-(1,1,7,7-tetramethyl-2,3,6,7-tetrahydro-1H,5H-benzo[ij]ki] 2-{2-tert-butyl-6-[2-(1,1,7,7-tetramethyl-2,3,6,7-tetrahydro-1H,5H-benzo[ij]quinolizin-9-yl)ethenyl]-4H-pyran-4-ylidene}propanedinitrile (abbreviation: DCJTI), 2-{2-tert-butyl-6-[2-(1,1,7,7-tetramethyl-2,3,6,7-tetrahydro-1H,5H-benzo[ij]quinolizin-9-yl)ethenyl]-4H-pyran-4-ylidene}propanedinitrile (abbreviation: DCJTB), 2-(2,6-bis{2-[4-(di 2-{2,6-bis[2-(8-methoxy-1,1,7,7-tetramethyl-2,3,6,7-tetrahydro-1H,5H-benzo[ij]quinolizin-9-yl)ethenyl]-4H-pyran-4-ylidene}propanedinitrile (abbreviation: BisDCM), 2-{2,6-bis[2-(8-methoxy-1,1,7,7-tetramethyl-2,3,6,7-tetrahydro-1H,5H-benzo[ij]quinolizin-9-yl)ethenyl]-4H-pyran-4-ylidene}propanedinitrile (abbreviation: BisDCJ™), and the like can be used.

[0072] [Phosphorescent Material] A phosphorescent material can be used for the layer 111. For example, the phosphorescent materials exemplified below can be used for the layer 111. Note that the material is not limited thereto, and various known phosphorescent materials can be used for the layer 111.

[0073] For example, the layer 111 can be formed using an organometallic iridium complex having a 4H-triazole skeleton, an organometallic iridium complex having a 1H-triazole skeleton, an organometallic iridium complex having an imidazole skeleton, an organometallic iridium complex having a phenylpyridine derivative having an electron-withdrawing group as a ligand, an organometallic iridium complex having a pyrimidine skeleton, an organometallic iridium complex having a pyrazine skeleton, an organometallic iridium complex having a pyridine skeleton, a rare earth metal complex, a platinum complex, or the like.

[0074] [Phosphorescent Material (Blue)] Examples of organometallic iridium complexes having a 4H-triazole skeleton include tris{2-[5-(2-methylphenyl)-4-(2,6-dimethylphenyl)-4H-1,2,4-triazol-3-yl-κN]phenyl-κC}iridium(III) (abbreviation: [Ir(mpptz-dmp) ３ ]), tris(5-methyl-3,4-diphenyl-4H-1,2,4-triazolato)iridium(III) (abbreviation: [Ir(Mptz) ３ ]), tris[4-(3-biphenyl)-5-isopropyl-3-phenyl-4H-1,2,4-triazolato]iridium(III) (abbreviation: [Ir(iPrptz-3b) ３ ]), etc. can be used.

[0075] Examples of organometallic iridium complexes having a 1H-triazole skeleton include tris[3-methyl-1-(2-methylphenyl)-5-phenyl-1H-1,2,4-triazolato]iridium(III) (abbreviation: [Ir(Mptz1-mp) ３ ]), tris(1-methyl-5-phenyl-3-propyl-1H-1,2,4-triazolato)iridium(III) (abbreviation: [Ir(Prptz1-Me) ３ ]), etc. can be used.

[0076] Examples of organometallic iridium complexes having an imidazole skeleton include fac-tris[1-(2,6-diisopropylphenyl)-2-phenyl-1H-imidazole]iridium(III) (abbreviation: [Ir(iPrpmi) ３]), tris[3-(2,6-dimethylphenyl)-7-methylimidazo[1,2-f]phenanthridinato]iridium(III) (abbreviation: [Ir(dmpimpt-Me) ３ ]), etc. can be used.

[0077] Examples of organometallic iridium complexes having a phenylpyridine derivative having an electron-withdrawing group as a ligand include bis[2-(4',6'-difluorophenyl)pyridinato-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(CF ３ ppy) ２ (pic)]), bis[2-(4',6'-difluorophenyl)pyridinato-N,C ２’ ] Iridium (III) acetylacetonate (abbreviation: FIracac), etc. can be used.

[0078] These compounds exhibit blue phosphorescence and have a peak emission wavelength in the range of 440 nm to 520 nm.

[0079] [Phosphorescent Material (Green)] Examples of organometallic iridium complexes having a pyrimidine skeleton include tris(4-methyl-6-phenylpyrimidinato)iridium(III) (abbreviation: [Ir(mppm) ３ ]), tris(4-t-butyl-6-phenylpyrimidinato)iridium(III) (abbreviation: [Ir(tBuppm) ３ ]), (acetylacetonato)bis(6-methyl-4-phenylpyrimidinato)iridium(III) (abbreviation: [Ir(mppm) ２ (acac)]), (acetylacetonato)bis(6-tert-butyl-4-phenylpyrimidinato)iridium(III) (abbreviation: [Ir(tBuppm) ２(acac)]), (acetylacetonato)bis[6-(2-norbornyl)-4-phenylpyrimidinato]iridium(III) (abbreviation: [Ir(nbppm) ２ (acac)]), (acetylacetonato)bis[5-methyl-6-(2-methylphenyl)-4-phenylpyrimidinato]iridium(III) (abbreviation: [Ir(mpmppm) ２ (acac)]), (acetylacetonato)bis(4,6-diphenylpyrimidinato)iridium(III) (abbreviation: [Ir(dppm) ２ (acac)]), etc. can be used.

[0080] Examples of organometallic iridium complexes having a pyrazine skeleton include (acetylacetonato)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: [Ir(mppr-iPr) ２ (acac)]), etc. can be used.

[0081] Examples of organometallic iridium complexes having a pyridine skeleton include tris(2-phenylpyridinato-N,C ２’ ) Iridium(III) (abbreviation: [Ir(ppy) ３ ]), bis(2-phenylpyridinato-N,C ２’ ) Iridium(III) acetylacetonate (abbreviation: [Ir(ppy) ２ (acac)]), bis(benzo[h]quinolinato)iridium(III) acetylacetonate (abbreviation: [Ir(bzq) ２ (acac)]), tris(benzo[h]quinolinato)iridium(III) (abbreviation: [Ir(bzq) ３ ]), tris(2-phenylquinolinato-N,C ２’ ) Iridium(III) (abbreviation: [Ir(pq) ３ ]), bis(2-phenylquinolinato-N,C ２’ ) iridium(III) acetylacetonate (abbreviation: [Ir(pq) ２(acac)]), [2-d3-methyl-8-(2-pyridinyl-κN)benzofuro[2,3-b]pyridine-κC]bis[2-(5-d3-methyl-2-pyridinyl-κN)phenyl-κC]iridium(III) (abbreviation: [Ir(5mppy-d3) ２ (mbfpypy-d3)]), [2-d3-methyl-(2-pyridinyl-κN)benzofuro[2,3-b]pyridine-κC]bis[2-(2-pyridinyl-κN)phenyl-κC]iridium(III) (abbreviation: [Ir(ppy) ２ (mbfpypy-d3)]), etc. can be used.

[0082] The rare earth metal complexes include tris(acetylacetonato)(monophenanthroline)terbium(III) (abbreviation: [Tb(acac) ３ (Phen)]), etc.

[0083] These compounds mainly exhibit green phosphorescence, with a peak emission wavelength between 500 nm and 600 nm. Organometallic iridium complexes having a pyrimidine skeleton are also remarkably superior in reliability and luminous efficiency.

[0084] [Phosphorescent material (red)] Examples of organometallic iridium complexes having a pyrimidine skeleton include (diisobutyrylmethanato)bis[4,6-bis(3-methylphenyl)pyrimidinato]iridium(III) (abbreviation: [Ir(5mdppm) ２ (dibm)]), bis[4,6-bis(3-methylphenyl)pyrimidinato](dipivaloylmethanato)iridium(III) (abbreviation: [Ir(5mdppm) ２ (dpm)]), bis[4,6-di(naphthalen-1-yl)pyrimidinato](dipivaloylmethanato)iridium(III) (abbreviation: [Ir(dpm) ２ (dpm)]), etc. can be used.

[0085] Examples of organometallic iridium complexes having a pyrazine skeleton include (acetylacetonato)bis(2,3,5-triphenylpyrazinato)iridium(III) (abbreviation: [Ir(tppr) ２(acac)]), bis(2,3,5-triphenylpyrazinato)(dipivaloylmethanato)iridium(III) (abbreviation: [Ir(tppr) ２ (dpm)]), (acetylacetonato)bis[2,3-bis(4-fluorophenyl)quinoxalinato]iridium(III) (abbreviation: [Ir(Fdpq) ２ (acac)]), etc. can be used.

[0086] Examples of organometallic iridium complexes having a pyridine skeleton include tris(1-phenylisoquinolinato-N,C ２’ ) Iridium(III) (abbreviation: [Ir(piq) ３ ]), bis(1-phenylisoquinolinato-N,C ２’ ) iridium(III) acetylacetonate (abbreviation: [Ir(piq) ２ (acac)]), etc. can be used.

[0087] Examples of rare earth metal complexes include tris(1,3-diphenyl-1,3-propanedionato)(monophenanthroline)europium(III) (abbreviation: [Eu(DBM) ３ (Phen)]), tris[1-(2-thenoyl)-3,3,3-trifluoroacetonato](monophenanthroline)europium(III) (abbreviation: [Eu(TTA) ３ (Phen)]), etc. can be used.

[0088] As the platinum complex, 2,3,7,8,12,13,17,18-octaethyl-21H,23H-porphyrin platinum(II) (abbreviation: PtOEP) and the like can be used.

[0089] These compounds exhibit red phosphorescence, with an emission peak at 600 nm to 700 nm. The organometallic iridium complexes having a pyrazine skeleton emit red light with a chromaticity suitable for use in display devices.

[0090] [Substances Exhibiting Thermally Activated Delayed Fluorescence (TADF)] A TADF material can be used for the layer 111. For example, the TADF materials exemplified below can be used as the luminescent material. However, without being limited thereto, various known TADF materials can be used as the luminescent material.

[0091] TADF materials have a small difference between the S1 and T1 levels, allowing reverse intersystem crossing (upconversion) from a triplet excited state to a singlet excited state with a small amount of thermal energy. This allows efficient generation of a singlet excited state from a triplet excited state. Furthermore, the triplet excited energy can be converted into luminescence.

[0092] Furthermore, an exciplex (also called an exciplex) that forms an excited state with two types of substances has an extremely small difference between the S1 level and the T1 level, and functions as a TADF material that can convert triplet excitation energy into singlet excitation energy.

[0093] The T1 level can be determined by using a phosphorescence spectrum observed at low temperatures (e.g., 77 K to 10 K). When a tangent line is drawn at the base of the fluorescence spectrum on the short wavelength side, and the energy of the wavelength at which the extrapolated line intersects the horizontal axis is defined as the S1 level, and a tangent line is drawn at the base of the phosphorescence spectrum on the short wavelength side, and the energy of the wavelength at which the extrapolated line intersects the horizontal axis is defined as the T1 level, the difference between the S1 level and the T1 level is preferably 0.3 eV or less, and more preferably 0.2 eV or less.

[0094] When a TADF material is used as a light-emitting material, the S1 level of the host material is preferably higher than the S1 level of the TADF material, and the T1 level of the host material is preferably higher than the T1 level of the TADF material.

[0095] For example, TADF materials can include fullerene and its derivatives, acridine and its derivatives, eosin derivatives, etc. Also, metal-containing porphyrins containing magnesium (Mg), zinc (Zn), cadmium (Cd), tin (Sn), platinum (Pt), indium (In), palladium (Pd), etc. can be used as TADF materials.

[0096] Specifically, protoporphyrin-tin fluoride complex (SnF), whose structural formula is shown below, ２ (Proto IX)), mesoporphyrin-tin fluoride complex (SnF ２ (Meso IX)), hematoporphyrin-tin fluoride complex (SnF ２ (Hemato IX)), coproporphyrin tetramethyl ester-tin fluoride complex (SnF ２ (Copro III-4Me)), octaethylporphyrin-tin fluoride complex (SnF ２ (OEP)), etioporphyrin-tin fluoride complex (SnF ２ (Etio I)), octaethylporphyrin-platinum chloride complex (PtCl ２ OEP), etc. can be used.

[0097]

[0098] Furthermore, for example, a heterocyclic compound having one or both of a π-electron rich heteroaromatic ring and a π-electron deficient heteroaromatic ring can be used as the TADF material.

[0099] Specifically, the structural formulas of these compounds are as follows: 2-(biphenyl-4-yl)-4,6-bis(12-phenylindolo[2,3-a]carbazol-11-yl)-1,3,5-triazine (abbreviation: PIC-TRZ), 9-(4,6-diphenyl-1,3,5-triazin-2-yl)-9′-phenyl-9H,9′H-3,3′-bicarbazole (abbreviation: PCCzTzn), 2-{4-[3-(N-phenyl-9H-carbazol-3-yl)-9H-carbazol-9-yl]phenyl}-4,6-diphenyl-1,3,5-triazine (abbreviation: PCCzPTzn), 2-[4-(10H-phenoxazin-10-yl)phenyl]-4 ,6-diphenyl-1,3,5-triazine (abbreviation: 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-acridin-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[acridin-9,9′-anthracene]-10′-one (abbreviation: ACRSA), and the like can be used.

[0100]

[0101] The heterocyclic compound has a π-electron-rich heteroaromatic ring and a π-electron-deficient heteroaromatic ring, and therefore has high electron transport and hole transport properties, and is therefore preferred. In particular, among skeletons having a π-electron-deficient heteroaromatic ring, a pyridine skeleton, a diazine skeleton (pyrimidine skeleton, pyrazine skeleton, pyridazine skeleton), and a triazine skeleton are preferred because they are stable. In particular, a benzofuropyrimidine skeleton, a benzothienopyrimidine skeleton, a benzofuropyrazine skeleton, and a benzothienopyrazine skeleton are preferred because they have high electron acceptability and good reliability.

[0102] Among skeletons having a π-electron-rich heteroaromatic ring, it is preferable to have at least one of an acridine skeleton, a phenoxazine skeleton, a phenothiazine skeleton, a furan skeleton, a thiophene skeleton, and a pyrrole skeleton because they are stable. Note that the dibenzofuran skeleton is preferable as the furan skeleton, and the dibenzothiophene skeleton is preferable as the thiophene skeleton. Furthermore, the indole skeleton, the carbazole skeleton, the indolocarbazole skeleton, the bicarbazole skeleton, and the 3-(9-phenyl-9H-carbazol-3-yl)-9H-carbazole skeleton are particularly preferable as the pyrrole skeleton.

[0103] In addition, a substance in which a π-electron-rich heteroaromatic ring and a π-electron-deficient heteroaromatic ring are directly bonded is particularly preferred because the electron-donating property of the π-electron-rich heteroaromatic ring and the electron-accepting property of the π-electron-deficient heteroaromatic ring are both strong, and the energy difference between the S1 level and the T1 level is small, thereby enabling efficient thermally activated delayed fluorescence to be obtained. In addition, an aromatic ring bonded to an electron-withdrawing group such as a cyano group may be used instead of the π-electron-deficient heteroaromatic ring. In addition, an aromatic amine skeleton, a phenazine skeleton, or the like may be used as the π-electron-rich skeleton.

[0104] Furthermore, examples of the π-electron-deficient skeleton that can be used include a xanthene skeleton, a thioxanthene dioxide skeleton, an oxadiazole skeleton, a triazole skeleton, an imidazole skeleton, an anthraquinone skeleton, a boron-containing skeleton such as phenylborane or boranthrene, an aromatic ring or heteroaromatic ring having a nitrile group or a cyano group such as benzonitrile or cyanobenzene, a carbonyl skeleton such as benzophenone, a phosphine oxide skeleton, and a sulfone skeleton.

[0105] In this way, a π-electron-deficient skeleton and a π-electron-rich skeleton can be used in place of at least one of a π-electron-deficient heteroaromatic ring and a π-electron-rich heteroaromatic ring.

[0106] <<Structure Example 2 of Layer 111>> A material having carrier transport properties can be used as the host material. For example, a material having hole transport properties, a material having electron transport properties, a substance exhibiting thermally activated delayed fluorescence (TADF), a material having an anthracene skeleton, a mixed material, or the like can be used as the host material. Note that a structure using a material having a larger band gap than the light-emitting material contained in the layer 111 as the host material is preferable. This can suppress energy transfer from excitons generated in the layer 111 to the host material.

[0107] [Material having hole transport properties] A material having a hole mobility of 1×10 −６ cm ２ A material having a hole transporting property can be suitably used as a material having a hole transporting property.

[0108] For example, an amine compound or an organic compound having a π-electron-rich heteroaromatic ring skeleton can be used as a material having hole transport properties. Specifically, a compound having an aromatic amine skeleton, a compound having a carbazole skeleton, a compound having a thiophene skeleton, a compound having a furan skeleton, or the like can be used. In particular, a compound having an aromatic amine skeleton or a compound having a carbazole skeleton is preferable because it has good reliability, high hole transport properties, and contributes to reducing driving voltage.

[0109] Examples of compounds having an aromatic amine skeleton include 4,4'-bis[N-(1-naphthyl)-N-phenylamino]biphenyl (abbreviation: NPB), N,N'-bis(3-methylphenyl)-N,N'-diphenyl-[1,1'-biphenyl]-4,4'-diamine (abbreviation: TPD), 4,4'-bis[N-(spiro-9,9'-bifluoren-2-yl)-N-phenylamino]biphenyl (abbreviation: BSPB), 4-phenyl-4'-(9-phenylfluoren-9-yl)triphenylamine (abbreviation: BPAFLP), 4-phenyl-3'-(9-phenylfluoren-9-yl)triphenylamine (abbreviation: mBPAFLP), and 4-phenyl-4'-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBA1BP). , 4,4'-diphenyl-4''-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBBiBP), 4-(1-naphthyl)-4'-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBANB), 4,4'-di(1-naphthyl)-4''-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBNBB), 9,9-dimethyl-N-phenyl-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]fluoren-2-amine (abbreviation: PCBAF), N-phenyl-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]spiro-9,9'-bifluoren-2-amine (abbreviation: PCBASF), and the like can be used.

[0110] Examples of compounds having a carbazole skeleton that can be used include 1,3-bis(N-carbazolyl)benzene (abbreviation: mCP), 4,4′-di(N-carbazolyl)biphenyl (abbreviation: CBP), 3,6-bis(3,5-diphenylphenyl)-9-phenylcarbazole (abbreviation: CzTP), and 3,3′-bis(9-phenyl-9H-carbazole) (abbreviation: PCCP).

[0111] Examples of compounds having a thiophene skeleton that can be used include 4,4′,4″-(benzene-1,3,5-triyl)tri(dibenzothiophene) (abbreviation: DBT3P-II), 2,8-diphenyl-4-[4-(9-phenyl-9H-fluoren-9-yl)phenyl]dibenzothiophene (abbreviation: DBTFLP-III), and 4-[4-(9-phenyl-9H-fluoren-9-yl)phenyl]-6-phenyldibenzothiophene (abbreviation: DBTFLP-IV).

[0112] Examples of compounds having a furan skeleton that can be used include 4,4′,4″-(benzene-1,3,5-triyl)tri(dibenzofuran) (abbreviation: DBF3P-II), 4-{3-[3-(9-phenyl-9H-fluoren-9-yl)phenyl]phenyl}dibenzofuran (abbreviation: mmDBFFLBi-II), and the like.

[0113] [Electron-Transporting Material] For example, a metal complex or an organic compound having a π-electron-deficient heteroaromatic ring skeleton can be used as the electron-transporting material.

[0114] Examples of metal complexes include bis(10-hydroxybenzo[h]quinolinato)beryllium(II) (abbreviation: BeBq ２ ), bis(2-methyl-8-quinolinolato)(4-phenylphenolato)aluminum(III) (abbreviation: BAlq), bis(8-quinolinolato)zinc(II) (abbreviation: Znq), bis[2-(2-benzoxazolyl)phenolato]zinc(II) (abbreviation: ZnPBO), bis[2-(2-benzothiazolyl)phenolato]zinc(II) (abbreviation: ZnBTZ), and the like can be used.

[0115] Examples of organic compounds having a π-electron-deficient heteroaromatic ring skeleton include heterocyclic compounds having a polyazole skeleton, heterocyclic compounds having a diazine skeleton, heterocyclic compounds having a pyridine skeleton, and heterocyclic compounds having a triazine skeleton. In particular, heterocyclic compounds having a diazine skeleton or heterocyclic compounds having a pyridine skeleton are preferred because of their high reliability. Furthermore, heterocyclic compounds having a diazine (pyrimidine or pyrazine) skeleton have high electron transport properties and can reduce driving voltage.

[0116] Examples of heterocyclic compounds having a polyazole skeleton include 2-(4-biphenylyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole (abbreviation: PBD), 3-(4-biphenylyl)-4-phenyl-5-(4-tert-butylphenyl)-1,2,4-triazole (abbreviation: TAZ), 1,3-bis[5-(p-tert-butylphenyl)-1,3,4-oxadiazol-2-yl]benzene (abbreviation: O XD-7), 9-[4-(5-phenyl-1,3,4-oxadiazol-2-yl)phenyl]-9H-carbazole (abbreviation: CO11), 2,2′,2″-(1,3,5-benzenetriyl)tris(1-phenyl-1H-benzimidazole) (abbreviation: TPBI), 2-[3-(dibenzothiophen-4-yl)phenyl]-1-phenyl-1H-benzimidazole (abbreviation: mDBTBIm-II), and the like can be used.

[0117] Examples of heterocyclic compounds having a diazine skeleton include 2-[3-(dibenzothiophen-4-yl)phenyl]dibenzo[f,h]quinoxaline (abbreviation: 2mDBTPDBq-II), 2-[3′-(dibenzothiophen-4-yl)biphenyl-3-yl]dibenzo[f,h]quinoxaline (abbreviation: 2mDBTBPDBq-II), 2-[3′-(9H-carbazol-9-yl)biphenyl-3-yl]dibenzo[f,h]quinoxaline (abbreviation: 2mDBTBPDBq-II), and 2-[3′-(9H-carbazol-9-yl)biphenyl-3-yl]dibenzo[f,h]quinoxaline (abbreviation: 2mDBTBPDBq-II). ]quinoxaline (abbreviation: 2mCzBPDBq), 4,6-bis[3-(phenanthrene-9-yl)phenyl]pyrimidine (abbreviation: 4,6mPnP2Pm), 4,6-bis[3-(4-dibenzothienyl)phenyl]pyrimidine (abbreviation: 4,6mDBTP2Pm-II), 4,8-bis[3-(dibenzothiophen-4-yl)phenyl]benzo[h]quinazoline (abbreviation: 4,8mDBtP2Bqn), etc. can be used.

[0118] Examples of heterocyclic compounds having a pyridine skeleton include 3,5-bis[3-(9H-carbazol-9-yl)phenyl]pyridine (abbreviation: 35DCzPPy), 1,3,5-tri[3-(3-pyridyl)phenyl]benzene (abbreviation: TmPyPB), and the like.

[0119] Examples of heterocyclic compounds having a triazine skeleton include 2-[3′-(9,9-dimethyl-9H-fluoren-2-yl)biphenyl-3-yl]-4,6-diphenyl-1,3,5-triazine (abbreviation: mFBPTzn), 2-[(1,1′-biphenyl)-4-yl]-4-phenyl-6-[9,9′-spirobi(9H-fluoren)-2-yl]-1,3,5-triazine (abbreviation: BP-SFT zn), 2-{3-[3-(benzo[b]naphtho[1,2-d]furan-8-yl)phenyl]phenyl}-4,6-diphenyl-1,3,5-triazine (abbreviation: mBnfBPTzn), 2-{3-[3-(benzo[b]naphtho[1,2-d]furan-6-yl)phenyl]phenyl}-4,6-diphenyl-1,3,5-triazine (abbreviation: mBnfBPTzn-02), and the like can be used.

[0120] [Materials Having an Anthracene Skeleton] Organic compounds having an anthracene skeleton can be used as host materials. In particular, when a fluorescent material is used as the light-emitting material, organic compounds having an anthracene skeleton are suitable. This allows for the realization of light-emitting devices with good luminous efficiency and durability.

[0121] As the organic compound having an anthracene skeleton, an organic compound having a diphenylanthracene skeleton, particularly a 9,10-diphenylanthracene skeleton, is preferred because it is chemically stable. Furthermore, when the host material has a carbazole skeleton, it is preferred because it has improved hole injection and transport properties. In particular, when the host material contains a dibenzocarbazole skeleton, it is preferred because its HOMO level is shallower by about 0.1 eV than that of carbazole, making it easier for holes to enter, and it also has excellent hole transport properties and high heat resistance. From the viewpoint of hole injection and transport properties, a benzofluorene skeleton or a dibenzofluorene skeleton may be used instead of the carbazole skeleton.

[0122] Therefore, a substance having both a 9,10-diphenylanthracene skeleton and a carbazole skeleton, a substance having both a 9,10-diphenylanthracene skeleton and a benzocarbazole skeleton, or a substance having both a 9,10-diphenylanthracene skeleton and a dibenzocarbazole skeleton is preferable as the host material.

[0123] For example, 6-[3-(9,10-diphenyl-2-anthryl)phenyl]-benzo[b]naphtho[1,2-d]furan (abbreviation: 2mBnfPPA), 9-phenyl-10-{4-(9-phenyl-9H-fluoren-9-yl)biphenyl-4′-yl}anthracene (abbreviation: FLPPA), 9-(1-naphthyl)-10-[4-(2-naphthyl)phenyl]anthracene (abbreviation: αN-βNPAnth), 9-phenyl-3-[4-(10-phenyl [4-(10-phenyl-9-anthryl)phenyl]-9H-carbazole (abbreviation: PCzPA), 9-[4-(10-phenyl-9-anthracenyl)phenyl]-9H-carbazole (abbreviation: CzPA), 7-[4-(10-phenyl-9-anthryl)phenyl]-7H-dibenzo[c,g]carbazole (abbreviation: cgDBCzPA), 3-[4-(1-naphthyl)phenyl]-9-phenyl-9H-carbazole (abbreviation: PCPN), and the like can be used.

[0124] In particular, CzPA, cgDBCzPA, 2mBnfPPA, and PCzPA exhibit very good properties.

[0125] [Substances Exhibiting Thermally Activated Delayed Fluorescence (TADF)] A TADF material can be used as a host material. When a TADF material is used as a host material, triplet excitation energy generated in the TADF material can be converted to singlet excitation energy by reverse intersystem crossing. Furthermore, the excitation energy can be transferred to a light-emitting material. In other words, the TADF material functions as an energy donor, and the light-emitting material functions as an energy acceptor. This can improve the luminous efficiency of a light-emitting device.

[0126] This is very effective when the luminescent material is a fluorescent luminescent material. Furthermore, in this case, in order to obtain high luminous efficiency, it is preferable that the S1 level of the TADF material is higher than the S1 level of the fluorescent luminescent material. Furthermore, it is preferable that the T1 level of the TADF material is higher than the S1 level of the fluorescent luminescent material. Therefore, it is preferable that the T1 level of the TADF material is higher than the T1 level of the fluorescent luminescent material.

[0127] It is also preferable to use a TADF material that emits light that overlaps with the wavelength of the lowest-energy absorption band of the fluorescent material, since this allows for smooth transfer of excitation energy from the TADF material to the fluorescent material, resulting in efficient light emission.

[0128] Furthermore, in order to efficiently generate singlet excitation energy from triplet excitation energy through reverse intersystem crossing, it is preferable that carrier recombination occurs in the TADF material. It is also preferable that the triplet excitation energy generated in the TADF material does not transfer to the triplet excitation energy of the fluorescent material. To this end, it is preferable that the fluorescent material has a protecting group around the luminophore (the skeleton responsible for luminescence) possessed by the fluorescent material. The protecting group is preferably a substituent that does not have a π bond, and is preferably a saturated hydrocarbon. Specific examples include alkyl groups having 3 to 10 carbon atoms, substituted or unsubstituted cycloalkyl groups having 3 to 10 carbon atoms, and trialkylsilyl groups having 3 to 10 carbon atoms. It is even more preferable that there are multiple protecting groups. Substituents that do not have a π bond have poor carrier transport function, so the distance between the TADF material and the luminophore of the fluorescent material can be increased without significantly affecting carrier transport or carrier recombination.

[0129] Here, the term "luminophore" refers to an atomic group (skeleton) that causes light emission in a fluorescent substance. The luminophore preferably has a skeleton having a π bond, preferably contains an aromatic ring, and preferably has a fused aromatic ring or a fused heteroaromatic ring.

[0130] Examples of the fused aromatic ring or fused heteroaromatic ring include a phenanthrene skeleton, a stilbene skeleton, an acridone skeleton, a phenoxazine skeleton, a phenothiazine skeleton, etc. In particular, fluorescent substances having a naphthalene skeleton, an anthracene skeleton, a fluorene skeleton, a chrysene skeleton, a triphenylene skeleton, a tetracene skeleton, a pyrene skeleton, a perylene skeleton, a coumarin skeleton, a quinacridone skeleton, or a naphthobisbenzofuran skeleton are preferred because of their high fluorescence quantum yield.

[0131] For example, a TADF material that can be used as a light-emitting material can be used as a host material.

[0132] [Configuration Example 1 of Mixed Material] A material obtained by mixing a plurality of substances can be used as the host material. For example, a material having an electron-transporting property and a material having a hole-transporting property can be used as the mixed material. The weight ratio of the material having a hole-transporting property to the material having an electron-transporting property contained in the mixed material may be set to (material having a hole-transporting property / material having an electron-transporting property) = (1 / 19) or more and (19 / 1) or less. This allows the carrier transport property of the layer 111 to be easily adjusted. Furthermore, the recombination region can be easily controlled.

[0133] [Configuration Example 2 of Mixed Material] A material mixed with a phosphorescent material can be used as a host material. When a fluorescent material is used as an emitting material, the phosphorescent material can be used as an energy donor that provides excitation energy to the fluorescent material.

[0134] [Structure Example 3 of Mixed Material] A mixed material containing a material that forms an exciplex can be used as a host material. For example, a material whose emission spectrum of the formed exciplex overlaps with the wavelength of the lowest-energy absorption band of the light-emitting material can be used as a host material. This makes energy transfer smooth, thereby improving light-emitting efficiency. Alternatively, driving voltage can be suppressed. With such a structure, light emission can be efficiently obtained using Exciplex-Triple Energy Transfer (ExTET), which is energy transfer from the exciplex to the light-emitting material (phosphorescent material).

[0135] At least one of the materials forming the exciplex can be a phosphorescent material, which allows for the utilization of reverse intersystem crossing or the efficient conversion of triplet excitation energy to singlet excitation energy.

[0136] As a combination of materials for forming an exciplex, it is preferable that the HOMO level of the material having hole transport properties is equal to or higher than the HOMO level of the material having electron transport properties. Alternatively, it is preferable that the LUMO level of the material having hole transport properties is equal to or higher than the LUMO level of the material having electron transport properties. This allows for efficient formation of an exciplex. The LUMO level and HOMO level of the material can be derived from electrochemical properties (reduction potential and oxidation potential). Specifically, the reduction potential and oxidation potential can be measured using cyclic voltammetry (CV) measurement.

[0137] The formation of exciplexes can be confirmed, for example, by comparing the emission spectra of a material having hole transport properties, a material having electron transport properties, and a mixed film obtained by mixing these materials, and observing the phenomenon in which the emission spectrum of the mixed film is shifted to longer wavelengths than the emission spectra of each material (or has a new peak on the longer wavelength side). Alternatively, the formation of exciplexes can be confirmed by comparing the transient photoluminescence (PL) of a material having hole transport properties, the transient PL of a material having electron transport properties, and a mixed film obtained by mixing these materials, and observing differences in transient response, such as the transient PL lifetime of the mixed film having a longer-lifetime component or a larger proportion of delayed components than the transient PL lifetimes of the individual materials. The above-mentioned transient PL may also be interpreted as transient electroluminescence (EL). In other words, the formation of exciplexes can also be confirmed by comparing the transient EL of a material having hole transport properties, the transient EL of a material having electron transport properties, and a mixed film obtained by mixing these materials, and observing the differences in transient response.

[0138] <<Structure Example of Layer 113>> The layer 113 is sandwiched between the layer 111 and the electrode 552 and has a single-layer structure or a stacked-layer structure. The layer 113 contains an organic compound BPM. For example, a material having an electron-transporting property can be used for the layer 113. The layer 113 can also be referred to as an electron-transporting layer. Note that a structure in which a material having a larger band gap than that of the light-emitting material contained in the layer 111 is used for the layer 113 is preferable. This can suppress energy transfer from excitons generated in the layer 111 to the layer 113.

[0139] [Example 1 of Organic Compound BPM] The organic compound BPM has a π-electron deficient heteroaromatic ring skeleton and a π-electron rich heteroaromatic ring skeleton.

[0140] The organic compound BPM has a HOMO level HOMO1, which is in the range of −6.0 eV to −5.6 eV (see FIG. 1B).

[0141] Examples of the π-electron-rich heteroaromatic ring skeleton include a carbazole skeleton, an acridine skeleton, a phenoxazine skeleton, a phenothiazine skeleton, a furan skeleton, a thiophene skeleton, and a pyrrole skeleton. In particular, when the organic compound BPM has a carbazole skeleton, the HOMO level HOMO1 of the organic compound BPM is likely to fall within a suitable range. In addition, the HOMO level HOMO1 of the organic compound BPM is easily controlled.

[0142] Examples of the π-electron-deficient heteroaromatic ring skeleton include a pyridine skeleton, a diazine skeleton (pyrimidine skeleton, pyrazine skeleton, pyridazine skeleton), and a triazine skeleton.

[0143] [Example 2 of Organic Compound BPM] Examples of organic compound BPM having a π-electron-deficient heteroaromatic ring skeleton and a carbazole skeleton include 3,5-bis[3-(9H-carbazol-9-yl)phenyl]pyridine (abbreviation: 35DCzPPy), 2-[3′-(9H-carbazol-9-yl)biphenyl-3-yl]dibenzo[f,h]quinoxaline (abbreviation: 2mCzBPDBq), 2-[4′-(9-phenyl-9H-carbazol-3-yl)-3,1′-biphenyl-1-yl]dibenzo[f,h]quinoxaline (abbreviation: 2mpPCBPDBq), 2-[4-(3,6-diphenyl)-2-(4-phenyl-2-(4-phenyl) ... phenyl-9H-carbazol-9-yl)phenyl]dibenzo[f,h]quinoxaline (abbreviation: 2CzPDBq-III), 4,6-bis[3-(9H-carbazol-9-yl)phenyl]pyrimidine (abbreviation: 4,6mCzP2Pm), 9,9'-[pyrimidine-4,6-diylbis(biphenyl-3,3'-diyl)]bis(9H-carbazole) (abbreviation: 4,6mCzBP2Pm), 6-(1,1'-biphenyl-3-yl)-4-[3,5-bis(9H-carbazol-9-yl)phenyl]-2-phenylpyrimidine (abbreviation: 6mB P-4Cz2PPm), 4-[3,5-bis(9H-carbazol-9-yl)phenyl]-2-phenyl-6-(1,1'-biphenyl-4-yl)pyrimidine (abbreviation: 6BP-4Cz2PPm), 7-[4-(9-phenyl-9H-carbazol-2-yl)quinazolin-2-yl]-7H-dibenzo[c,g]carbazole (abbreviation: PC-cgDBCzQz), 2-{4-[3-(N-phenyl-9H-carbazol-3-yl)-9H-carbazol-9-yl]phenyl}-4,6-diphenyl-1,3,5-triazine (abbreviation: P CCzPTzn), 9-[3-(4,6-diphenyl-1,3,5-triazin-2-yl)phenyl]-9'-phenyl-2,3'-bi-9H-carbazole (abbreviation: mPCCzPTzn-02), 11-(4-[1,1'-diphenyl]-4-yl-6-phenyl-1,3,5-triazin-2-yl)-11,12-dihydro-12-phenyl-indolo[2,3-a]carbazole (abbreviation: BP-Icz(II)Tzn), 5-[3-(4,6-diphenyl-1,3,5-triazin-2-yl)phenyl]-7,7-dimethyl-5H,7H-indeno[2,1-b]carbazole (abbreviation: mINc(II)PTzn), 3-[9-(4,6-diphenyl-1,3,5-triazin-2-yl)-2-dibenzofuranyl]-9-phenyl-9H-carbazole (abbreviation: PCDBfTzn), 2-{3-[3-(N-phenyl-9H-carbazol-3-yl)-9H-carbazol-9-yl]phenyl}dibenzo[f,h]quinoxaline (abbreviation: 2mPCCzPDBq), etc. can be used.

[0144] [Example 3 of Organic Compound BPM] The organic compound BPM is represented by the following general formula (G1).

[0145]

[0146] In the above general formula (G1), D represents a substituted or unsubstituted quinoxalinyl group.

[0147] The substituted or unsubstituted quinoxalinyl group can be represented by, for example, the following general formula (D-1): １ ~R １０ One of these is Ar, and the others are hydrogen, a hydrocarbon group having 1 to 10 carbon atoms, an alicyclic hydrocarbon group having 3 to 10 carbon atoms, or a substituted or unsubstituted aromatic hydrocarbon group having 6 to 14 carbon atoms. Examples of the substituent on the aromatic hydrocarbon group include an alkyl group having 1 to 4 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 10 carbon atoms, a substituted or unsubstituted aromatic hydrocarbon group having 6 to 30 carbon atoms, or a substituted or unsubstituted heteroaromatic hydrocarbon group having 2 to 30 carbon atoms.

[0148] More specifically, a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a tert-butyl group, an n-hexyl group, etc. can be used as the substituent. Also, for example, a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, an adamantyl group, etc. can be used as the substituent. Also, for example, a phenyl group, a naphthyl group, a biphenyl group, a fluorenyl group, a spirofluorenyl group, etc. can be used as the substituent. Also, for example, a pyridine ring, a diazine ring (pyrimidine ring, pyrazine ring, pyridazine ring), a triazine ring, a quinoline ring, a quinoxaline ring, a quinazoline ring, a benzoquinazoline ring, a phenanthroline ring, an azafluoranthene ring, an imidazole ring, an oxazole ring, an oxadiazole ring, a triazole ring, etc. can be used as the substituent.

[0149]

[0150] In addition, in the above general formula (G1), E represents a substituted or unsubstituted carbazolyl group.

[0151] The substituted or unsubstituted carbazolyl group can be represented by, for example, the following general formula (E-1): ２１ ~R ２９ One of these is Ar, and the others are hydrogen, a hydrocarbon group having 1 to 10 carbon atoms, an alicyclic hydrocarbon group having 3 to 10 carbon atoms, or a substituted or unsubstituted aromatic hydrocarbon group having 6 to 14 carbon atoms. Examples of the substituent that the aromatic hydrocarbon group may have include an alkyl group having 1 to 4 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 10 carbon atoms, a substituted or unsubstituted aromatic hydrocarbon group having 6 to 30 carbon atoms, or a substituted or unsubstituted heteroaromatic hydrocarbon group having 2 to 30 carbon atoms. More specifically, the substituents already exemplified can be used for the substituent.

[0152]

[0153] In addition, in the above general formula (G1), Ar represents a substituted or unsubstituted arylene group, and the aromatic hydrocarbon group has 6 to 13 carbon atoms constituting the ring.

[0154] The substituted or unsubstituted arylene group can be represented by, for example, the following general formulas (Ar-1) to (Ar-14). Ar may have a substituent having a π-electron-deficient heteroaromatic ring skeleton or a substituent having a π-electron-rich heteroaromatic ring skeleton. In other words, in addition to D or E shown in general formula (G1), Ar may have a substituent having a π-electron-deficient heteroaromatic ring skeleton or a π-electron-rich heteroaromatic ring skeleton. Therefore, for example, multiple quinoxalinyl groups may be bonded to Ar, or multiple carbazolyl groups may be bonded to Ar. The substituent on the arylene group may be, for example, an alkyl group having 1 to 4 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 10 carbon atoms, a substituted or unsubstituted aromatic hydrocarbon group having 6 to 30 carbon atoms, or a substituted or unsubstituted heteroaromatic hydrocarbon group having 2 to 30 carbon atoms. More specifically, the substituents already exemplified above may be used as the substituent.

[0155]

[0156] [Example 4 of Organic Compound BPM] In particular, the organic compounds shown below, such as 2-[4′-(9-phenyl-9H-carbazol-3-yl)-3,1′-biphenyl-1-yl]dibenzo[f,h]quinoxaline (abbreviation: 2mpPCBPDBq) or 3-[3,5-di(carbazol-9-yl)phenyl]phenanthro[9,10-b]pyrazine (abbreviation: 2Cz2PDBq), can be suitably used as the organic compound BPM.

[0157]

[0158] The organic compound BPM includes a diazine skeleton and a π-electron-rich heteroaromatic ring skeleton, which facilitates electron transfer from the electrode 552 to the layer 111. Additionally, the organic compound BPM includes a π-electron-deficient heteroaromatic ring skeleton and a carbazole skeleton, and the HOMO level HOMO1 is in the range of −6.0 eV to −5.6 eV, which facilitates hole transfer from the layer 111 to the layer 113. Furthermore, accumulation of holes at the interface between the layer 111 and the layer 113 can be reduced, which can suppress deterioration of the organic compound. As a result, a novel light-emitting device with excellent convenience, usefulness, and reliability can be provided.

[0159] <<Configuration Example 1 of Layer 104 >> The layer 104 is sandwiched between the electrode 551 and the unit 103 , and the layer 104 is in contact with the electrode 551 .

[0160] A material having a hole-injecting property can be used for the layer 104. The layer 104 can also be referred to as a hole-injecting layer. For example, the layer 104 includes an organic compound HM1 and an organic compound AM1.

[0161] The organic compound AM1 has an electron accepting property with respect to the organic compound HM1, which makes it easier to inject holes from, for example, the electrode 551. Alternatively, the driving voltage of the light-emitting device can be reduced.

[0162] Organic and inorganic compounds can be used as the electron-accepting material. The electron-accepting material can extract electrons from the adjacent hole-transporting layer or the material having hole-transporting properties when an electric field is applied.

[0163] For example, a compound having an electron-withdrawing group (a halogen group or a cyano group) can be used as the electron-accepting substance. Fluorine is particularly preferred as the halogen group because it is stable. Furthermore, organic compounds having electron-accepting properties can be easily vapor-deposited and formed into films. This can increase the productivity of light-emitting devices.

[0164] Specifically, 7,7,8,8-tetracyano-2,3,5,6-tetrafluoroquinodimethane (abbreviation: F ４-TCNQ), chloranil, 2,3,6,7,10,11-hexacyano-1,4,5,8,9,12-hexaazatriphenylene (abbreviation: HAT-CN), 1,3,4,5,7,8-hexafluorotetracyano-naphthoquinodimethane (abbreviation: F6-TCCNNQ), 2-(7-dicyanomethylene-1,3,4,5,6,8,9,10-octafluoro-7H-pyren-2-ylidene)malononitrile, and the like can be used.

[0165] In particular, a compound in which an electron-withdrawing group is bonded to a condensed aromatic ring having a plurality of heteroatoms, such as HAT-CN, is thermally stable and is therefore preferred.

[0166] [Example of Organic Compound AM1] The organic compound AM1 has a lowest unoccupied molecular orbital (LUMO) level of −5.0 eV or less (see FIG. 1B). Preferably, the organic compound AM1 contains fluorine.

[0167] [3] Radialene derivatives having an electron-withdrawing group (particularly a halogen group such as a fluoro group or a cyano group) are also preferred because they have very high electron-accepting properties.

[0168] Specifically, α,α',α''-1,2,3-cyclopropane triylidene tris[4-cyano-2,3,5,6-tetrafluorobenzeneacetonitrile], α,α',α''-1,2,3-cyclopropane triylidene tris[2,6-dichloro-3,5-difluoro-4-(trifluoromethyl)benzeneacetonitrile], α,α',α''-1,2,3-cyclopropane triylidene tris[2,3,4,5,6-pentafluorobenzeneacetonitrile], and the like can be used.

[0169] <<Configuration Example 2 of Layer 104>> The layer 104 has a hole mobility of 1×10 when the square root of the electric field strength [V / cm] is 600. −３ cm / Vs or less. ４ [Ω・cm] or more 1×10 ７ Preferably, the resistivity is 5×10 ４ [Ω・cm] or more 1×10 ７ [Ω cm] or less, and more preferably, 1×10 ５[Ω・cm] or more 1×10 ７ It has a resistivity of [Ω·cm] or less.

[0170] Considering the effect of suppressing crosstalk, the higher the resistivity of the layer 104 in the light-emitting device of one embodiment of the present invention, the better. However, it has been found that if the resistivity is too high, hole injection is hindered, and a light-emitting device with a long lifetime cannot be obtained. Therefore, the resistivity of the material constituting the layer 104 is set to 1×10 ４ [Ω・cm] or more 1×10 ７ The light emitting device has a long life, and a light emitting apparatus using the light emitting device can be a light emitting apparatus with good display quality in which crosstalk is suppressed.

[0171] In terms of the crosstalk suppression effect, the resistivity is 5×10 ４ [Ω・cm] or more 1×10 ７ Ω cm] or less, and 1 × 10 ５ [Ω・cm] or more 1×10 ７ [Ω·cm] or less is more preferable.

[0172] [Examples of organic compound HM1] For example, compounds having an aromatic amine skeleton, carbazole derivatives, aromatic hydrocarbons, aromatic hydrocarbons having a vinyl group, polymeric compounds (oligomers, dendrimers, polymers, etc.), etc. can be used as the organic compound HM1.

[0173] Furthermore, a substance having a relatively deep HOMO level can be used for the organic compound HM1. The organic compound HM1 has a HOMO level HOMO2. The HOMO level HOMO2 is in the range of -5.7 eV to -5.2 eV, preferably -5.7 eV to -5.3 eV, and more preferably -5.7 eV to -5.4 eV (see FIG. 1B ). This facilitates hole injection into the unit 103. It also facilitates hole injection into the layer 112. It also moderately suppresses hole induction. It also increases the resistivity of the layer 104 to an appropriate range. It also suppresses crosstalk between adjacent light-emitting devices.

[0174] Examples of organic compounds having a relatively deep HOMO level include N-(4-biphenyl)-6,N-diphenylbenzo[b]naphtho[1,2-d]furan-8-amine (abbreviation: BnfABP), N,N-bis(4-biphenyl)-6-phenylbenzo[b]naphtho[1,2-d]furan-8-amine (abbreviation: BBABnf), 4,4′-bis(6-phenylbenzo[b]naphtho[1,2-d]furan-8-yl)-4″-phenyltriphenylamine (abbreviation: BnfBB1BP), N,N-bis(4-biphenyl)benzo[b]naphtho[1,2-d]furan-8-yl)-4″-phenyltriphenylamine (abbreviation: BnfBB1BP), and N,N-bis(4-biphenyl)benzo[b]naphtho[1,2-d]furan-8-yl. N,N-bis(4-biphenyl)benzo[b]naphtho[1,2-d]furan-6-amine (abbreviation: BBABnf(6)), N,N-bis(4-biphenyl)benzo[b]naphtho[1,2-d]furan-8-amine (abbreviation: BBABnf(8)), N,N-bis(4-biphenyl)benzo[b]naphtho[2,3-d]furan-4-amine (abbreviation: BBABnf(II)(4)), N,N-bis[4-(dibenzofuran-4-yl)phenyl]-4-amino-p-terphenyl (abbreviation: DBfBB1TP), N-[4-(dibenzothiophen-4-yl)phenyl] -N-phenyl-4-biphenylamine (abbreviation: ThBA1BP), 4-(2-naphthyl)-4',4''-diphenyltriphenylamine (abbreviation: BBAβNB), 4-[4-(2-naphthyl)phenyl]-4',4''-diphenyltriphenylamine (abbreviation: BBAβNBi), 4,4'-diphenyl-4''-(6;1'-binaphthyl-2-yl)triphenylamine (abbreviation: BBAαNβNB), 4,4'-diphenyl-4''-(7;1'-binaphthyl-2-yl)triphenylamine (abbreviation: BBAαNβ NB-03), 4,4'-diphenyl-4''-(7-phenyl)naphthyl-2-yltriphenylamine (abbreviation: BBAPβNB-03), 4,4'-diphenyl-4''-(6;2'-binaphthyl-2-yl)triphenylamine (abbreviation: BBA(βN2)B), 4,4'-diphenyl-4''-(7;2'-binaphthyl-2-yl)triphenylamine (abbreviation: BBA(βN2)B-03) 4,4'-diphenyl-4''-(4;2'-binaphthyl-1-yl)triphenylamine (abbreviation: BBAβNαNB), 4,4'-Diphenyl-4''-(5;2'-binaphthyl-1-yl)triphenylamine (abbreviation: BBAβNαNB-02), 4-(4-biphenylyl)-4'-(2-naphthyl)-4''-phenyltriphenylamine (abbreviation: TPBiAβNB), 4-(3-biphenylyl)-4'-[4-(2-naphthyl)phenyl]-4''-phenyltriphenylamine (abbreviation: mTPBiAβNBi), 4-(4-biphenylyl)-4'-[4-(2-naphthyl)phenyl]-4' 4,4'-diphenyl-4''-[4'-(carbazol-9-yl)biphenyl-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-[4'-(carbazol-9-yl)biphenyl-4-yl]-4'-(2-naphthyl)-4''-phenyltriphenylamine (abbreviation: YGTBiβNB), N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-N-[4-(1-naphthyl)phenyl]-9,9'-spirobi[9H-fluorene]-2-amine (abbreviation: PCBNBSF), N,N-bis([1,1'-biphenyl-4-yl]amine N,N-bis([1,1′-biphenyl]-4-yl)-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-(9,9-dimethyl-9H-fluoren-2-yl)dibenzofuran-4-amine (abbreviation: FrBiF), N-[4-(1-naphthyl)phenyl]-N-[3-(6-phenyldibenzofuran-4-yl)phenyl]-1-naphthylamine (abbreviation: mPDBfBNBN), 4-phenyl-4'-(9-phenylfluoren-9-yl)triphenylamine (abbreviation: BPAFLP), 4-phenyl-3'-(9-phenylfluoren-9-yl)triphenylamine (abbreviation: mBPAFLP), 4-phenyl-4'-[4-(9-phenylfluoren-9-yl)phenyl]triphenylamine (abbreviation: BPAFLBi), 4-phenyl-4'-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBA1BP), 4,4'-diphenyl-4 Examples of compounds that can be used include 4-(1-naphthyl)-4′-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBBiBP), 4-(1-naphthyl)-4′-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBANB), 4,4′-di(1-naphthyl)-4″-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBNBB), N-phenyl-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]spiro-9,9′-bifluoren-2-amine (abbreviation: PCBASF), N-(1,1′-biphenyl-4-yl)-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-9,9-dimethyl-9H-fluoren-2-amine (abbreviation: PCBBiF), and the like. ,

[0175] <<Structure Example of Layer 112>> The layer 112 is sandwiched between the layer 104 and the layer 111 and has a single-layer structure or a stacked-layer structure. The layer 112 is in contact with the layer 104 (see FIG. 1A).

[0176] The layer 112 contains an organic compound HM2. For example, a material having a hole-transporting property can be used for the layer 112. The layer 112 can also be referred to as a hole-transporting layer. Note that it is preferable that the layer 112 be made of a material having a larger band gap than that of the light-emitting material contained in the layer 111. This can suppress energy transfer from excitons generated in the layer 111 to the layer 112.

[0177] [Material having hole transport properties] A material having a hole mobility of 1×10 −６ cm ２ A material having a hole transporting property can be suitably used as a material having a hole transporting property.

[0178] For example, a material having a hole-transporting property that can be used for the layer 111 can be used for the layer 112. Specifically, a material having a hole-transporting property that can be used for a host material can be used for the layer 112.

[0179] [Example of Organic Compound HM2] The organic compound HM2 has a HOMO level HOMO3. The HOMO level HOMO3 is in the range of −0.2 eV to 0 eV relative to the HOMO level HOMO2 (see FIG. 1B).

[0180] This facilitates the movement of holes from the electrode 551 toward the layer 111. Furthermore, the region contributing to light emission near the layer 111 can be appropriately expanded toward the layer 113. Furthermore, the distribution of excitons generated by carrier recombination can be expanded in the thickness direction. Furthermore, the deterioration of the organic compound via the excited state can be suppressed. Furthermore, the reliability of the layer 111 can be improved. As a result, a novel light-emitting device with excellent convenience, usefulness, and reliability can be provided.

[0181] Note that this embodiment mode can be appropriately combined with other embodiment modes described in this specification.

[0182] Embodiment 2 In this embodiment, a structure of a light-emitting device 550 of one embodiment of the present invention will be described with reference to FIG. 1A.

[0183] <Structure Example of Light-Emitting Device 550> The light-emitting device 550 described in this embodiment includes an electrode 551, an electrode 552, a unit 103, and a layer 105. The electrode 552 has a region overlapping with the electrode 551, and the unit 103 has a region sandwiched between the electrode 551 and the electrode 552. The layer 105 has a region sandwiched between the unit 103 and the electrode 552. Note that the structure described in Embodiment 1 can be used for the unit 103, for example.

[0184] <Structure Example of Electrode 552> For example, a conductive material can be used for the electrode 552. Specifically, a material containing a metal, an alloy, or a conductive compound can be used for the electrode 552 in a single layer or stacked layers.

[0185] For example, the material that can be used for the electrode 551 described in Embodiment 1 can be used for the electrode 552. In particular, a material having a work function smaller than that of the electrode 551 can be suitably used for the electrode 552. Specifically, a material having a work function of 3.8 eV or less is preferable.

[0186] For example, the electrode 552 can be made of elements belonging to Group 1 of the periodic table, elements belonging to Group 2 of the periodic table, rare earth metals, and alloys containing these.

[0187] Specifically, lithium (Li), cesium (Cs), magnesium (Mg), calcium (Ca), strontium (Sr), europium (Eu), ytterbium (Yb), and alloys containing these (MgAg, AlLi) can be used for the electrode 552.

[0188] <Structure Example of Layer 105> For example, a material having an electron injecting property can be used for the layer 105. The layer 105 can also be referred to as an electron injecting layer.

[0189] Specifically, a substance having donor properties can be used for the layer 105. Alternatively, a composite material of a substance having donor properties and a material having electron-transporting properties can be used for the layer 105. Alternatively, an electride can be used for the layer 105. This can facilitate injection of electrons from the electrode 552, for example. Alternatively, not only a material having a low work function but also a material having a high work function can be used for the electrode 552. Alternatively, a material for the electrode 552 can be selected from a wide range of materials regardless of the work function. Specifically, Al, Ag, ITO, indium oxide-tin oxide containing silicon or silicon oxide, or the like can be used for the electrode 552. Alternatively, the driving voltage of the light-emitting device can be reduced.

[0190] [Substance Having Donor Properties] For example, alkali metals, alkaline earth metals, rare earth metals, or compounds thereof (oxides, halides, carbonates, etc.) can be used as the substance having donor properties. Alternatively, organic compounds such as tetrathianaphthacene (abbreviation: TTN), nickelocene, and decamethylnickelocene can also be used as the substance having donor properties.

[0191] Examples of alkali metal compounds (including oxides, halides, and carbonates) that can be used include lithium oxide, lithium fluoride (LiF), cesium fluoride (CsF), lithium carbonate, cesium carbonate, and 8-hydroxyquinolinato-lithium (abbreviated as Liq).

[0192] Alkaline earth metal compounds (including oxides, halides, and carbonates) include calcium fluoride (CaF ２ ), etc. can be used.

[0193] [Configuration Example 1 of Composite Material] A composite material of a plurality of substances can be used as a material having an electron injecting property. For example, a material having a donor property and a material having an electron transport property can be used as a composite material.

[0194] [Electron-Transporting Material] For example, a metal complex or an organic compound having a π-electron-deficient heteroaromatic ring skeleton can be used as the electron-transporting material.

[0195] For example, the material having an electron transporting property that can be used for the unit 103 can be used for the composite material.

[0196] [Configuration Example 2 of Composite Material] A microcrystalline alkali metal fluoride and a material having an electron-transporting property can be used for the composite material. Alternatively, a microcrystalline alkaline earth metal fluoride and a material having an electron-transporting property can be used for the composite material. In particular, a composite material containing 50 wt % or more of an alkali metal fluoride or an alkaline earth metal fluoride can be preferably used. Alternatively, a composite material containing an organic compound having a bipyridine skeleton can be preferably used. This can reduce the refractive index of the layer 105. Alternatively, the external quantum efficiency of the light-emitting device can be improved.

[0197] [Structure Example 3 of Composite Material] For example, a composite material containing a first organic compound having an unshared electron pair and a first metal can be used for the layer 105. The sum of the number of electrons in the first organic compound and the number of electrons in the first metal is preferably an odd number. The molar ratio of the first metal to 1 mole of the first organic compound is preferably 0.1 to 10, more preferably 0.2 to 2, and even more preferably 0.2 to 0.8.

[0198] This allows the first organic compound having an unshared electron pair to interact with the first metal to form a Singly Occupied Molecular Orbital (SOMO). Furthermore, when electrons are injected from the electrode 552 into the layer 105, the barrier between them can be reduced. Furthermore, since the first metal has low reactivity with water and oxygen, the moisture resistance of the light-emitting device can be improved.

[0199] The spin density measured by electron spin resonance (ESR) is preferably 1×10 １６ spins / cm ３ or more, more preferably 5 × 10 １６ spins / cm ３ More preferably, 1×10 １７ spins / cm ３ The above composite material can be used for the layer 105 .

[0200] [Organic Compound Having an Unshared Electron Pair] For example, a material having electron transport properties can be used as an organic compound having an unshared electron pair. For example, a compound having an electron-deficient heteroaromatic ring can be used. Specifically, a compound having at least one of a pyridine ring, a diazine ring (pyrimidine ring, pyrazine ring, pyridazine ring), and a triazine ring can be used. This can reduce the driving voltage of the light-emitting device.

[0201] The organic compound having an unshared electron pair preferably has a lowest unoccupied molecular orbital (LUMO) of -3.6 eV to -2.3 eV. Generally, the HOMO level and LUMO level of an organic compound can be estimated by cyclic voltammetry (CV), photoelectron spectroscopy, optical absorption spectroscopy, inverse photoelectron spectroscopy, or the like.

[0202] For example, 4,7-diphenyl-1,10-phenanthroline (abbreviation: BPhen), 2,9-bis(naphthalen-2-yl)-4,7-diphenyl-1,10-phenanthroline (abbreviation: NBPhen), diquinoxalino[2,3-a:2',3'-c]phenazine (abbreviation: HATNA), 2,4,6-tris[3'-(pyridin-3-yl)biphenyl-3-yl]-1,3,5-triazine (abbreviation: TmPPPyTz), etc. can be used as the organic compound having an unshared electron pair. Note that NBPhen has a higher glass transition temperature (Tg) and is superior in heat resistance compared to BPhen.

[0203] Furthermore, for example, copper phthalocyanine, which has an odd number of electrons, can be used as the organic compound having an unshared electron pair.

[0204] [First Metal] For example, when the number of electrons in the first organic compound having an unshared electron pair is even, a composite material of the first organic compound and a metal belonging to an odd group in the periodic table can be used for the layer 105.

[0205] For example, manganese (Mn), a Group 7 metal, cobalt (Co), a Group 9 metal, copper (Cu), silver (Ag), and gold (Au), which are Group 11 metals, and aluminum (Al) and indium (In), which are Group 13 metals, belong to odd-numbered groups in the periodic table. The elements of Group 11 have lower melting points than the elements of Groups 7 and 9, making them suitable for vacuum deposition. Ag is particularly preferred due to its low melting point.

[0206] Note that by using Ag for the electrode 552 and the layer 105, adhesion between the layer 105 and the electrode 552 can be improved.

[0207] When the number of electrons in the first organic compound having an unshared electron pair is odd, a composite material of the first metal and the first organic compound that belong to an even group in the periodic table can be used for the layer 105. For example, iron (Fe), which is a metal in Group 8 of the periodic table, belongs to an even group in the periodic table.

[0208] [Electride] For example, a substance in which electrons are added to a mixed oxide of calcium and aluminum at a high concentration can be used as a material having electron injection properties.

[0209] Note that this embodiment mode can be appropriately combined with other embodiment modes described in this specification.

[0210] Embodiment 3 In this embodiment, a structure of a light-emitting device 550 of one embodiment of the present invention will be described with reference to FIG. 2A.

[0211] FIG. 2A is a cross-sectional view illustrating a structure of a light-emitting device according to one embodiment of the present invention.

[0212] <Configuration Example of Light-Emitting Device 550> Furthermore, light-emitting device 550 described in this embodiment has electrode 551, electrode 552, unit 103, and intermediate layer 106 (see FIG. 2A ). Electrode 552 has a region overlapping with electrode 551, and unit 103 has a region sandwiched between electrode 551 and electrode 552. Intermediate layer 106 has a region sandwiched between unit 103 and electrode 552.

[0213] <<Configuration Example of Intermediate Layer 106>> The intermediate layer 106 includes a layer 106_1 and a layer 106_2. The layer 106_2 includes a region sandwiched between the layer 106_1 and the electrode 552.

[0214] <<Structure Example of Layer 106_1>> For example, a material having electron transporting properties can be used for the layer 106_1. The layer 106_1 can also be referred to as an electron relay layer. By using the layer 106_1, a layer in contact with the anode side of the layer 106_1 can be separated from a layer in contact with the cathode side of the layer 106_1. The interaction between the layer in contact with the anode side of the layer 106_1 and the layer in contact with the cathode side of the layer 106_1 can be reduced. Electrons can be smoothly supplied to the layer in contact with the anode side of the layer 106_1.

[0215] A substance having a LUMO level between the LUMO level of an electron-accepting substance included in a layer in contact with the anode side of the layer 106_1 and the LUMO level of a substance included in a layer in contact with the cathode side of the layer 106_1 can be suitably used for the layer 106_1.

[0216] For example, a material having a LUMO level in the range of −5.0 eV or higher, preferably −5.0 eV or higher and −3.0 eV or lower, can be used for the layer 106_1.

[0217] Specifically, a phthalocyanine-based material can be used for the layer 106_1. Alternatively, a metal complex having a metal-oxygen bond and an aromatic ligand can be used for the layer 106_1.

[0218] <<Structure Example of Layer 106_2>> For example, a material that supplies electrons to the anode side and holes to the cathode side when a voltage is applied can be used for the layer 106_2. Specifically, electrons can be supplied to the unit 103 disposed on the anode side. The layer 106_2 can also be referred to as a charge generation layer.

[0219] Specifically, the layer 106_2 can be formed using a material having a hole-injecting property that can be used for the layer 104. For example, a composite material can be used for the layer 106_2. Alternatively, the layer 106_2 can be formed using a stacked film in which a film including the composite material and a film including a material having a hole-transporting property are stacked.

[0220] Note that this embodiment mode can be appropriately combined with other embodiment modes described in this specification.

[0221] Embodiment 4 In this embodiment, a structure of a light-emitting device 550 of one embodiment of the present invention will be described with reference to FIG. 2B.

[0222] FIG. 2B is a cross-sectional view illustrating a structure of a light-emitting device according to one embodiment of the present invention, which has a structure different from that illustrated in FIG. 2A.

[0223] <Configuration Example of Light-Emitting Device 550> The light-emitting device 550 described in this embodiment includes an electrode 551, an electrode 552, a unit 103, an intermediate layer 106, and a unit 103_2 (see FIG. 2B ). The electrode 552 includes a region overlapping with the electrode 551. The unit 103 includes a region sandwiched between the electrode 551 and the electrode 552, the intermediate layer 106 includes a region sandwiched between the unit 103 and the electrode 552, and the unit 103_2 includes a region sandwiched between the intermediate layer 106 and the electrode 552. The unit 103_2 has a function of emitting light EL1_2. The light-emitting device 550 also includes a layer 105_2, which includes a region sandwiched between the unit 103 and the intermediate layer 106.

[0224] In other words, the light-emitting device 550 has multiple stacked units between the electrode 551 and the electrode 552. The number of stacked units is not limited to two, and three or more units can be stacked. A configuration including multiple stacked units sandwiched between the electrode 551 and the electrode 552 and the intermediate layer 106 sandwiched between the multiple units is sometimes referred to as a stacked light-emitting device or a tandem light-emitting device. This allows for high-luminance light emission while maintaining a low current density. It also improves reliability. It also allows for a reduction in drive voltage compared with devices with the same luminance. It also allows for reduced power consumption.

[0225] <<Structure Example 1 of Unit 103_2>> The unit 103_2 includes a layer 111_2, a layer 112_2, and a layer 113_2. Note that the structure that can be used for the unit 103 can be used for the unit 103_2. For example, the same structure as the unit 103 can be used for the unit 103_2.

[0226] <<Configuration Example 2 of Unit 103_2>> Furthermore, a configuration different from that of the unit 103 can be used for the unit 103_2. For example, a configuration emitting a different light color from that of the unit 103 can be used for the unit 103_2. Specifically, the unit 103 that emits red light and green light and the unit 103_2 that emits blue light can be used. This makes it possible to provide a light-emitting device that emits light of a desired color. For example, it is possible to provide a light-emitting device that emits white light.

[0227] The intermediate layer 106 has a function of supplying electrons to one of the unit 103 and the unit 103_2 and supplying holes to the other. For example, the intermediate layer 106 described in Embodiment 3 can be used.

[0228] <Structure Example of Layer 105_2> For example, a material having an electron injecting property can be used for the layer 105_2. The layer 105_2 can be referred to as an electron injecting layer. For example, the material that can be used for the layer 105 described in Embodiment 2 can be used for the layer 105_2.

[0229] <Method for Manufacturing the Light-Emitting Device 550> For example, the electrode 551, the electrode 552, the unit 103, the intermediate layer 106, and the unit 103_2 can be formed by a dry method, a wet method, a vapor deposition method, a droplet discharge method, a coating method, a printing method, or the like. Different methods can be used to form each component.

[0230] Specifically, the light-emitting device 550 can be manufactured using a vacuum deposition device, an inkjet device, a spin coater, a coating device, a gravure printing device, an offset printing device, a screen printing device, or the like.

[0231] For example, an electrode can be formed by a wet method using a paste of a metal material or a sol-gel method. Also, an indium oxide-zinc oxide film can be formed by a sputtering method using a target containing 1 wt % to 20 wt % of zinc oxide added to indium oxide. Also, an indium oxide (IWZO) film containing tungsten oxide and zinc oxide can be formed by a sputtering method using a target containing 0.5 wt % to 5 wt % of tungsten oxide and 0.1 wt % to 1 wt % of zinc oxide added to indium oxide.

[0232] Note that this embodiment mode can be appropriately combined with other embodiment modes described in this specification.

[0233] Embodiment 5 In this embodiment, a structure of a functional panel 700 according to one embodiment of the present invention will be described with reference to FIGS. 3A and 3B. FIG.

[0234] FIG. 3A is a cross-sectional view illustrating a configuration of a functional panel 700 according to one embodiment of the present invention, and FIG. 3B is a cross-sectional view illustrating a configuration of the functional panel 700 according to another embodiment of the present invention, which is different from that shown in FIG. 3A.

[0235] In this specification, etc., a device fabricated using a metal mask or an FMM (fine metal mask, high-resolution metal mask) may be referred to as a device with an MM (metal mask) structure. Also, in this specification, etc., a device fabricated without using a metal mask or an FMM may be referred to as a device with an MML (metal maskless) structure.

[0236] <Configuration Example 1 of Functional Panel 700> Functional panel 700 described in this embodiment has light-emitting device 550X(i,j) and light-emitting device 550Y(i,j) (see FIG. 3A). Light-emitting device 550Y(i,j) is adjacent to light-emitting device 550X(i,j).

[0237] The functional panel 700 also has an insulating film 521 , and the light-emitting devices 550 X(i, j) and 550 Y(i, j) are formed on the insulating film 521 .

[0238] The light-emitting device 550X(i,j) includes an electrode 551X(i,j), an electrode 552, and a unit 103X(i,j). The light-emitting device 550X(i,j) also includes a layer 104 and a layer 105.

[0239] For example, any of the light-emitting devices described in any of Embodiments 1 to 4 can be used for the light-emitting device 550X(i,j). Specifically, a structure that can be used for the electrode 551 can be used for the electrode 551X(i,j). A structure that can be used for the unit 103 can be used for the unit 103X(i,j). A structure that can be used for the layer 104 can be used for the layer 104, and a structure that can be used for the layer 105 can be used for the layer 105.

[0240] <<Configuration Example 1 of Light-Emitting Device 550Y(i,j)>> The light-emitting device 550Y(i,j) described in this embodiment includes an electrode 551Y(i,j), an electrode 552, and a unit 103Y(i,j) (see FIG. 3A ). The electrode 552 has an area overlapping with the electrode 551Y(i,j), and the unit 103Y(i,j) has an area sandwiched between the electrode 551Y(i,j) and the electrode 552.

[0241] The electrode 551Y(i,j) is adjacent to the electrode 551X(i,j), and there is a gap 551XY(i,j) between the electrode 551Y(i,j) and the electrode 551X(i,j).

[0242] Furthermore, for example, the material that can be used for the electrode 551X(i,j) can be used for the electrode 551Y(i,j). Note that the potential supplied to the electrode 551Y(i,j) may be the same as or different from that of the electrode 551X(i,j). By supplying different potentials, the light-emitting device 550Y(i,j) can be driven under different conditions from those of the light-emitting device 550X(i,j).

[0243] <<Configuration Example 1 of Unit 103Y(i,j)>> The unit 103Y(i,j) has a single-layer structure or a laminated structure.

[0244] For example, the unit 103Y(i,j) can be formed of a layer selected from functional layers such as a light-emitting layer, a hole-transporting layer, an electron-transporting layer, a carrier-blocking layer, etc. Also, the unit 103Y(i,j) can be formed of a layer selected from functional layers such as a hole-injecting layer, an electron-injecting layer, an exciton-blocking layer, and a charge-generating layer, etc.

[0245] <<Configuration Example 2 of Unit 103Y(i,j)>> For example, the unit 103Y(i,j) includes a layer 111Y(i,j), a layer 112, and a layer 113 (see FIG. 3A).

[0246] Layer 112 has an area sandwiched between electrode 551Y(i,j) and layer 111Y(i,j), layer 111Y(i,j) has an area sandwiched between layer 112 and layer 113, and layer 113 has an area sandwiched between layer 111Y(i,j) and electrode 552.

[0247] <<Configuration Example 2 of Light-Emitting Device 550Y(i,j)>> The light-emitting device 550Y(i,j) also includes a layer 104 and a layer 105. The layer 104 includes a region sandwiched between the electrode 551Y(i,j) and the unit 103Y(i,j), and the layer 105 includes a region sandwiched between the unit 103Y(i,j) and the electrode 552.

[0248] Note that part of the configuration of the light-emitting device 550X(i,j) can be used as part of the configuration of the light-emitting device 550Y(i,j). This allows part of the configuration to be shared, and also simplifies the manufacturing process.

[0249] <Configuration Example 2 of Functional Panel 700> The functional panel 700 described in this embodiment has an insulating film 528 (see FIG. 3A).

[0250] <<Configuration Example of Insulating Film 528>> The insulating film 528 has openings, one of which overlaps with the electrode 551X(i,j) and the other of which overlaps with the electrode 551Y(i,j).

[0251] <Configuration example 3 of functional panel 700> The functional panel 700 described in this embodiment has a light-emitting device 550X(i,j) and a light-emitting device 550Y(i,j), and the light-emitting device 550Y(i,j) is adjacent to the light-emitting device 550X(i,j) (see Figure 3B).

[0252] The light-emitting device 550X(i,j) includes an electrode 551X(i,j), an electrode 552, and a unit 103X(i,j). The light-emitting device 550X(i,j) also includes a layer 104X(i,j) and a layer 105. The same structure as that of the layer 104 can be used for the layer 104X(i,j).

[0253] The light-emitting device 550Y(i,j) includes an electrode 551Y(i,j), an electrode 552, and a unit 103Y(i,j). The light-emitting device 550Y(i,j) also includes a layer 104Y(i,j) and a layer 105, and the electrode 551Y(i,j) is separated from the electrode 551X(i,j) by a gap 551XY(i,j).

[0254] The layer 104Y(i,j) is sandwiched between the electrode 551Y(i,j) and the electrode 552, the layer 104Y(i,j) is in contact with the electrode 551Y(i,j), and the layer 104Y(i,j) contains an organic compound HM1. The layer 104Y(i,j) has a gap 104XY(i,j) between it and the layer 104X(i,j), and the gap 104XY(i,j) overlaps with the gap 551XY(i,j).

[0255] Furthermore, the light-emitting device 550Y(i,j) includes a unit 103Y(i,j), and the unit 103Y(i,j) includes a gap between it and the light-emitting device 550X(i,j).

[0256] 3A in that layer 104Y(i,j) has a gap 104XY(i,j) between it and layer 104X(i,j), and in that in the configuration of unit 103Y(i,j), layer 112Y(i,j) has a gap between it and layer 112X(i,j) and layer 113Y(i,j) has a gap between it and layer 113X(i,j). Here, the differences will be described in detail, and the above description will be used to refer to similar configurations.

[0257] <<Configuration Example of Layer 104Y(i,j)>> A material having hole injection properties can be used for the layer 104Y(i,j). The layer 104Y(i,j) can also be referred to as a hole injection layer. For example, the layer 104Y(i,j) contains an organic compound HM1 and an organic compound AM1. The layer 104Y(i,j) has a gap 104XY(i,j) between it and the layer 104X(i,j). This can drastically suppress the current flowing between the layer 104Y(i,j) and the layer 104X(i,j).

[0258] <<Configuration Example 3 of Unit 103Y(i,j)>> The unit 103Y(i,j) includes a layer 111Y(i,j), a layer 112Y(i,j), and a layer 113Y(i,j) (see FIG. 3B).

[0259] The layer 112Y(i,j) is sandwiched between the electrode 551Y(i,j) and the layer 111Y(i,j), and a gap is provided between the layer 112Y(i,j) and the layer 112X(i,j). Note that the same configuration as that for the layer 112 can be used for the layer 112Y(i,j).

[0260] Layer 111Y(i,j) is sandwiched between layer 112Y(i,j) and layer 113Y(i,j), and layer 111Y(i,j) has a gap between it and layer 111X(i,j).

[0261] The layer 113Y(i,j) is sandwiched between the layer 111Y(i,j) and the electrode 552, and the layer 113Y(i,j) has a gap between it and the layer 113X(i,j). Note that the same structure as that of the layer 113 can be used for the layer 113Y(i,j).

[0262] In other words, the unit 103Y(i,j) has a groove between it and the unit 103X(i,j), and the unit 103Y(i,j) has one sidewall along the groove. The unit 103X(i,j) also has another sidewall along the groove, and the other sidewall faces the one sidewall.

[0263] <Configuration Example 4 of Functional Panel 700> The functional panel 700 described in this embodiment includes, for example, an insulating film 573 (see FIG. 3B).

[0264] <<Configuration Example of Insulating Film 573>> The insulating film 573 includes an insulating film 573A and an insulating film 573B.

[0265] The insulating film 573A has a region sandwiched between the insulating film 573B and the insulating film 521, and is in contact with the insulating film 521. The insulating film 573A also has a region in contact with the side wall of the unit 103Y(i, j) and a region in contact with the side wall of the unit 103X(i, j).

[0266] <Configuration Example 5 of Functional Panel 700> Furthermore, functional panel 700 described in this embodiment includes layer 111Y(i, j) (see FIG. 3A or FIG. 3B).

[0267] <<Configuration Example 1 of Layer 111Y(i,j)>> For example, a light-emitting material or a light-emitting material and a host material can be used for the layer 111Y(i,j). The layer 111Y(i,j) can also be referred to as a light-emitting layer. Note that a configuration in which the layer 111Y(i,j) is disposed in a region where holes and electrons recombine can be preferred. This allows the energy generated by carrier recombination to be efficiently converted into light and emitted. Also, a configuration in which the layer 111Y(i,j) is disposed away from metals used for electrodes, etc. can be preferred. This can suppress the quenching phenomenon caused by metals used for electrodes, etc.

[0268] For example, a light-emitting material different from the light-emitting material used in the layer 111X(i,j) can be used in the layer 111Y(i,j). Specifically, light-emitting materials with different emission colors can be used in the layer 111Y(i,j). This allows light-emitting devices with different hues to be arranged. Alternatively, additive color mixing can be performed using multiple light-emitting devices with different hues. Alternatively, colors of hues that cannot be displayed by individual light-emitting devices can be expressed.

[0269] For example, a light-emitting device that emits blue light, a light-emitting device that emits green light, and a light-emitting device that emits red light can be arranged on the functional panel 700. Alternatively, a light-emitting device that emits white light, a light-emitting device that emits yellow light, and a light-emitting device that emits infrared light can be arranged on the functional panel 700.

[0270] <<Structure Example 2 of Layer 111Y(i, j)>> For example, a fluorescent material, a phosphorescent material, or a material exhibiting thermally activated delayed fluorescence (TADF) (also referred to as a TADF material) can be used as the light-emitting material, which allows energy generated by carrier recombination to be emitted from the light-emitting material as light EL2 (see FIG. 3A or 3B ).

[0271] For example, the layer 111Y(i, j) may be made of a fluorescent material that can be used in the layer 111. However, the present invention is not limited to this, and various known fluorescent materials may be used in the layer 111Y(i, j).

[0272] [Phosphorescent Material] For example, the layer 111Y(i,j) can be made of a phosphorescent material that can be used in the layer 111. However, the present invention is not limited to this, and various known phosphorescent materials can be used in the layer 111Y(i,j).

[0273] [Substance Exhibiting Thermally Activated Delayed Fluorescence (TADF)] For example, the layer 111Y(i,j) can be made of a TADF material that can be used for the layer 111. However, without being limited thereto, various known TADF materials can be used for the layer 111Y(i,j).

[0274] <<Structure Example 3 of Layer 111Y(i,j)>> A material having carrier transport properties can be used as the host material. For example, a material having hole transport properties, a material having electron transport properties, a substance exhibiting thermally activated delayed fluorescence (TADF), a material having an anthracene skeleton, a mixed material, or the like can be used as the host material. Note that a structure using a material having a larger band gap than the light-emitting material contained in the layer 111Y(i,j) is preferable. This can suppress energy transfer from excitons generated in the layer 111Y(i,j) to the host material.

[0275] For example, the host material that can be used for the layer 111 can be used for the layer 111Y(i,j).

[0276] <<Configuration Example of Layer 112Y(i,j)>> For example, a material having hole transport properties can be used for the layer 112Y(i,j). The layer 112Y(i,j) can also be referred to as a hole transport layer. Note that a configuration in which a material having a larger band gap than the light-emitting material contained in the layer 111Y(i,j) is used for the layer 112Y(i,j) is preferable. This can suppress energy transfer from excitons generated in the layer 111Y(i,j) to the layer 112Y(i,j).

[0277] [Material having hole transport properties] A material having a hole mobility of 1×10 −６ cm ２ A material having a hole transporting property can be suitably used as a material having a hole transporting property.

[0278] For example, the layer 112Y(i,j) can be formed using a material having a hole-transporting property that can be used for the layer 111. Specifically, the layer 112Y(i,j) can be formed using a material having a hole-transporting property that can be used for a host material.

[0279] <<Structure Example of Layer 113Y(i,j)>> For example, a material having an electron transporting property, a material having an anthracene skeleton, a mixed material, or the like can be used for the layer 113Y(i,j). The layer 113Y(i,j) can also be referred to as an electron transporting layer. Note that a structure in which a material having a larger band gap than that of the light-emitting material contained in the layer 111Y(i,j) is used for the layer 113Y(i,j) is preferable. This can suppress energy transfer from excitons generated in the layer 111Y(i,j) to the layer 113Y(i,j).

[0280] [Electron-Transporting Material] For example, a metal complex or an organic compound having a π-electron-deficient heteroaromatic ring skeleton can be used as the electron-transporting material.

[0281] For example, a material having an electron-transporting property that can be used for the layer 111Y(i,j) can be used for the layer 113Y(i,j). Specifically, a material having an electron-transporting property that can be used for a host material can be used for the layer 113Y(i,j).

[0282] Note that this embodiment mode can be appropriately combined with other embodiment modes described in this specification.

[0283] Embodiment 6 In this embodiment, a structure of a functional panel 700 according to one embodiment of the present invention will be described with reference to FIGS. 4 and 5. FIG.

[0284] FIG. 4A is a cross-sectional view illustrating a configuration of a functional panel 700 according to one embodiment of the present invention, and FIG. 4B is a cross-sectional view illustrating a configuration of the functional panel 700 according to another embodiment of the present invention that is different from that illustrated in FIG. 4A.

[0285] FIG. 5 is a cross-sectional view illustrating the configuration of a functional panel 700 according to one embodiment of the present invention.

[0286] <Configuration Example 1 of Functional Panel 700> The functional panel 700 described in this embodiment has a light-emitting device 550X(i, j) and an optical functional device 550S(i, j) (see FIG. 4A).

[0287] For example, the light-emitting devices described in any of Embodiments 1 to 4 can be used as the light-emitting device 550X(i, j).

[0288] <Configuration Example of Optical Functional Device 550S(i,j)> The optical functional device 550S(i,j) described in this embodiment has an electrode 551S(i,j), an electrode 552, and a unit 103S(i,j). The electrode 552 has an area overlapping with the electrode 551S(i,j), and the unit 103S(i,j) has an area sandwiched between the electrode 551S(i,j) and the electrode 552.

[0289] The optical functional device 550S(i,j) also includes a layer 104 and a layer 105. The layer 104 includes a region sandwiched between the electrode 551S(i,j) and the unit 103S(i,j), and the layer 105 includes a region sandwiched between the unit 103S(i,j) and the electrode 552. Note that part of the configuration of the light-emitting device 550X(i,j) can be used as part of the configuration of the optical functional device 550S(i,j). This allows part of the configuration to be shared, or simplifies the manufacturing process.

[0290] <Configuration Example 1 of Unit 103S(i,j)> The unit 103S(i,j) has a single-layer structure or a laminated structure. For example, the unit 103S(i,j) includes a layer 114S(i,j), a layer 112, and a layer 113 (see FIG. 4A).

[0291] Layer 114S(i,j) has an area sandwiched between layer 112 and layer 113, layer 112 has an area sandwiched between electrode 551S(i,j) and layer 114S(i,j), and layer 113 has an area sandwiched between layer 114S(i,j) and electrode 552.

[0292] For example, the unit 103S(i, j) may be a layer selected from functional layers such as a photoelectric conversion layer, a hole transport layer, an electron transport layer, a carrier blocking layer, etc. Also, the unit 103S(i, j) may be a layer selected from functional layers such as an exciton blocking layer and a charge generating layer.

[0293] The unit 103S(i,j) absorbs light hv and supplies electrons to one electrode and holes to the other electrode. For example, the unit 103S(i,j) supplies holes to the electrode 551S(i,j) and electrons to the electrode 552.

[0294] <Structure Example of Layer 112> For example, a material having a hole-transport property can be used for the layer 112. The layer 112 can be referred to as a hole-transport layer. For example, the structure described in Embodiment 1 can be used for the layer 112.

[0295] <Structure Example of Layer 113> For example, a material having an electron-transporting property, a material having an anthracene skeleton, a mixed material, or the like can be used for the layer 113. For example, the structure described in Embodiment 1 can be used for the layer 113.

[0296] <<Configuration Example 1 of Layer 114S(i,j)>> For example, an electron-accepting material and an electron-donating material can be used for the layer 114S(i,j). Specifically, a material that can be used for an organic solar cell can be used for the layer 114S(i,j). The layer 114S(i,j) can also be referred to as a photoelectric conversion layer. The layer 114S(i,j) absorbs light hv and supplies electrons to one electrode and holes to the other electrode. For example, the layer 114S(i,j) supplies holes to the electrode 551S(i,j) and electrons to the electrode 552.

[0297] [Examples of Electron Accepting Materials] For example, fullerene derivatives, non-fullerene electron acceptors, etc. can be used as the electron accepting material.

[0298] As the electron-accepting material, C ６０ Fullerene, C ７０ Examples of fullerene that can be used include [6,6]-Phenyl-C71-butylic acid methyl ester (abbreviation: PC70BM), [6,6]-Phenyl-C61-butylic acid methyl ester (abbreviation: PC60BM), and 1',1",4',4"-Tetrahydro-di[1,4]methanenaphthaleno[1,2:2',3',56,60:2",3"][5,6]fullerene-C60 (abbreviation: ICBA).

[0299] Examples of non-fullerene electron acceptors that can be used include perylene derivatives, compounds having a dicyanomethyleneindanone group, and N,N'-dimethyl-3,4,9,10-perylenedicarboximide (abbreviation: Me-PTCDI).

[0300] [Examples of Electron-Donating Materials] For example, phthalocyanine compounds, tetracene derivatives, quinacridone derivatives, rubrene derivatives, etc. can be used as electron-donating materials.

[0301] Examples of electron-donating materials that can be used include copper (II) phthalocyanine (abbreviation: CuPc), tin (II) phthalocyanine (abbreviation: SnPc), zinc phthalocyanine (abbreviation: ZnPc), tetraphenyldibenzoperiflanthene (abbreviation: DBP), and rubrene.

[0302] <<Configuration Example 2 of Layer 114S(i,j)>> For example, a single-layer structure or a stacked structure can be used for the layer 114S(i,j). Specifically, a bulk heterojunction structure can be used for the layer 114S(i,j). Alternatively, a heterojunction structure can be used for the layer 114S(i,j).

[0303] [Configuration Example of Mixed Material] For example, a mixed material containing an electron-accepting material and an electron-donating material can be used for the layer 114S(i,j). Note that a configuration in which a mixed material containing an electron-accepting material and an electron-donating material is used for the layer 114S(i,j) can be referred to as a bulk heterojunction type.

[0304] Specifically, C ７０ A mixed material including fullerenes and DBPs can be used for layer 114S(i,j).

[0305] [Heterojunction Example] Layer 114N(i,j) and layer 114P(i,j) can be used for layer 114S(i,j). Layer 114N(i,j) comprises a region sandwiched between one electrode and layer 114P(i,j), and layer 114P(i,j) comprises a region sandwiched between layer 114N(i,j) and the other electrode. For example, layer 114N(i,j) comprises a region sandwiched between electrode 552 and layer 114P(i,j), and layer 114P(i,j) comprises a region sandwiched between layer 114N(i,j) and electrode 551S(i,j) (see FIG. 4B ).

[0306] An n-type semiconductor can be used for the layer 114N(i,j). For example, Me-PTCDI can be used for the layer 114N(i,j).

[0307] Alternatively, a p-type semiconductor can be used for the layer 114P(i,j). For example, rubrene can be used for the layer 114P(i,j).

[0308] The optical functional device 550S(i,j) having a configuration in which the layer 114P(i,j) is in contact with the layer 114N(i,j) can be called a PN junction photodiode.

[0309] <Configuration example 2 of unit 103S(i,j)> Unit 103S(i,j) has layer 111Y(i,j), which has a region sandwiched between layer 114S(i,j) and layer 113 (see Figure 5).

[0310] Configuration example 2 of unit 103S(i,j) differs from configuration example 1 of unit 103S(i,j) in that it includes a layer 111Y(i,j). Here, the different parts will be described in detail, and the above description will be used for parts having the same configuration.

[0311] <<Configuration Example of Layer 111Y(i,j)>> For example, a light-emitting material or a light-emitting material and a host material can be used for the layer 111Y(i,j). The layer 111Y(i,j) can also be referred to as a light-emitting layer. Note that a configuration in which the layer 111Y(i,j) is disposed in a region where holes and electrons recombine can be preferred. This allows the energy generated by carrier recombination to be efficiently converted into light and emitted. Also, a configuration in which the layer 111Y(i,j) is disposed away from metals used for electrodes, etc. can be preferred. This can suppress the quenching phenomenon caused by metals used for electrodes, etc.

[0312] Specifically, the configuration described in the fifth embodiment can be used for the layer 111Y(i,j). In particular, a configuration that emits light with a wavelength that is not easily absorbed by the layer 114S(i,j) can be suitably used for the layer 111Y(i,j). This allows the light EL2 emitted by the layer 111Y(i,j) to be extracted with high efficiency.

[0313] Note that this embodiment mode can be appropriately combined with other embodiment modes described in this specification.

[0314] Embodiment Mode 7 In this embodiment mode, a light-emitting device using the light-emitting device described in any one of Embodiment Modes 1 to 4 will be described.

[0315] In this embodiment, a light-emitting device manufactured using the light-emitting device described in any one of Embodiments 1 to 4 will be described with reference to Fig. 6. Fig. 6A is a top view showing the light-emitting device, and Fig. 6B is a cross-sectional view taken along lines A-B and C-D in Fig. 6A. This light-emitting device has a pixel portion 602 and a driver circuit portion indicated by dotted lines to control light emission from the light-emitting device, and the driver circuit portion includes a source line driver circuit 601 and a gate line driver circuit 603. The light-emitting device also includes a sealing substrate 604 and a sealant 605, and the sealant 605 surrounds a space 607.

[0316] The routing wiring 608 is wiring for transmitting signals input to the source line driver circuit 601 and the gate line driver circuit 603, and receives video signals, clock signals, start signals, reset signals, etc. from an FPC (flexible printed circuit) 609, which serves as an external input terminal. Although only the FPC is shown here, a printed wiring board (PWB) may be attached to this FPC. In this specification, the light-emitting device includes not only the light-emitting device itself but also a state in which an FPC or PWB is attached to it.

[0317] Next, the cross-sectional structure will be described with reference to Fig. 6B. A driver circuit portion and a pixel portion are formed on an element substrate 610, and here, a source line driver circuit 601, which is the driver circuit portion, and one pixel in a pixel portion 602 are shown.

[0318] The element substrate 610 may be made of a substrate made of glass, quartz, organic resin, metal, alloy, semiconductor, or the like, or a plastic substrate made of FRP (Fiber Reinforced Plastics), PVF (Polyvinyl Fluoride), polyester, acrylic resin, or the like.

[0319] The structure of a transistor used in a pixel or a driver circuit is not particularly limited. For example, an inverted staggered transistor or a staggered transistor may be used. Furthermore, a top-gate transistor or a bottom-gate transistor may be used. The semiconductor material used for the transistor is not particularly limited, and examples thereof include silicon, germanium, silicon carbide, and gallium nitride. Alternatively, an oxide semiconductor containing at least one of indium, gallium, and zinc, such as an In—Ga—Zn-based metal oxide, may be used.

[0320] The crystallinity of a semiconductor material used for a transistor is not particularly limited, and any of an amorphous semiconductor and a crystalline semiconductor (a microcrystalline semiconductor, a polycrystalline semiconductor, a single crystal semiconductor, or a semiconductor having a crystalline region in part) may be used. The use of a crystalline semiconductor is preferable because it can suppress deterioration of transistor characteristics.

[0321] Here, it is preferable to use an oxide semiconductor for the transistors provided in the pixel or the driver circuit, as well as for semiconductor devices such as transistors used in touch sensors, which will be described later. In particular, it is preferable to use an oxide semiconductor having a wider band gap than silicon. By using an oxide semiconductor having a wider band gap than silicon, the current in the off state of the transistor can be reduced.

[0322] The oxide semiconductor preferably contains at least indium (In) or zinc (Zn), and more preferably contains an oxide represented by In-M-Zn-based oxide (M is a metal such as Al, Ti, Ga, Ge, Y, Zr, Sn, La, Ce, or Hf).

[0323] In particular, it is preferable to use, as the semiconductor layer, an oxide semiconductor film which has a plurality of crystal parts whose c-axes are oriented perpendicular to a surface on which the semiconductor layer is formed or a top surface of the semiconductor layer and which does not have grain boundaries between adjacent crystal parts.

[0324] By using such a material for the semiconductor layer, fluctuations in electrical characteristics are suppressed, and a highly reliable transistor can be realized.

[0325] Furthermore, a transistor having the above-described semiconductor layer can retain charge stored in a capacitor through the transistor for a long period of time due to its low off-state current. By applying such a transistor to a pixel, it is possible to stop the driver circuit while maintaining the gray level of an image displayed in each display region. As a result, an electronic device with extremely low power consumption can be realized.

[0326] For example, to stabilize the characteristics of a transistor, it is preferable to provide a base film. The base film can be formed as a single layer or a stacked layer using an inorganic insulating film such as a silicon oxide film, a silicon nitride film, a silicon oxynitride film, or a silicon nitride oxide film. The base film can be formed by a sputtering method, a CVD (Chemical Vapor Deposition) method (such as a plasma CVD method, a thermal CVD method, or a MOCVD (Metal Organic CVD) method), an ALD (Atomic Layer Deposition) method, a coating method, a printing method, or the like. Note that the base film need not be provided if it is not necessary.

[0327] Note that the FET 623 represents one of the transistors formed in the source line driver circuit 601. The driver circuit may be formed of various CMOS circuits, PMOS circuits, or NMOS circuits. In addition, although this embodiment shows a driver-integrated type in which the driver circuit is formed on a substrate, this is not necessarily required, and the driver circuit may also be formed externally rather than on the substrate.

[0328] Furthermore, the pixel portion 602 is formed by a plurality of pixels including a switching FET 611, a current control FET 612, and a first electrode 613 electrically connected to the drain of the FET, but is not limited to this, and the pixel portion may be formed by combining three or more FETs and a capacitance element.

[0329] An insulator 614 is formed to cover an end portion of the first electrode 613. Here, the insulator 614 can be formed by using a positive photosensitive acrylic resin film.

[0330] Furthermore, in order to improve the coverage of an EL layer or the like to be formed later, a curved surface having a curvature is formed at the upper or lower end of the insulator 614. For example, when a positive photosensitive acrylic resin is used as the material of the insulator 614, it is preferable that only the upper end of the insulator 614 has a curved surface having a curvature radius (0.2 μm or more and 3 μm or less). Furthermore, either a negative photosensitive resin or a positive photosensitive resin can be used as the insulator 614.

[0331] An EL layer 616 and a second electrode 617 are formed on the first electrode 613. Here, it is desirable to use a material with a large work function as the material used for the first electrode 613, which functions as an anode. For example, a single layer film such as an ITO film, an indium tin oxide film containing silicon, an indium oxide film containing 2 wt % to 20 wt % of zinc oxide, a titanium nitride film, a chromium film, a tungsten film, a Zn film, or a Pt film can be used. It is also possible to use a stacked structure of a titanium nitride film and a film mainly composed of aluminum, or a three-layer structure of a titanium nitride film, a film mainly composed of aluminum, and a titanium nitride film. The stacked structure provides low resistance as a wiring, good ohmic contact, and the first electrode 613 can function as an anode.

[0332] The EL layer 616 is formed by various methods such as an evaporation method using an evaporation mask, an ink-jet method, or a spin coating method. The EL layer 616 has the structure described in any one of Embodiments 1 to 4. Other materials constituting the EL layer 616 may be low-molecular-weight compounds or high-molecular-weight compounds (including oligomers and dendrimers).

[0333] Furthermore, as a material used for the second electrode 617 formed on the EL layer 616 and functioning as a cathode, a material having a small work function (Al, Mg, Li, Ca, or an alloy or compound thereof (MgAg, MgIn, AlLi, etc.)) is preferably used. Note that, when light generated in the EL layer 616 is transmitted through the second electrode 617, it is preferable to use a stack of a thin metal thin film and a transparent conductive film (ITO, indium oxide containing 2 wt % to 20 wt % zinc oxide, indium tin oxide containing silicon, zinc oxide (ZnO), etc.) as the second electrode 617.

[0334] Note that a light-emitting device is formed with the first electrode 613, the EL layer 616, and the second electrode 617. The light-emitting device is the light-emitting device described in any one of Embodiments 1 to 4. Note that a plurality of light-emitting devices are formed in a pixel portion, and the light-emitting device in this embodiment may include both the light-emitting device described in any one of Embodiments 1 to 4 and light-emitting devices having other structures.

[0335] Furthermore, by bonding the sealing substrate 604 to the element substrate 610 with a sealing material 605, a structure is formed in which a light-emitting device 618 is provided in a space 607 surrounded by the element substrate 610, the sealing substrate 604, and the sealing material 605. The space 607 is filled with a filler, and in some cases, the space is filled with an inert gas (nitrogen, argon, etc.), or with a sealing material. A recess is formed in the sealing substrate, and by providing a desiccant therein, deterioration due to the influence of moisture can be suppressed, which is a preferable configuration.

[0336] It is preferable to use an epoxy resin or glass frit for the sealing material 605. It is also desirable that these materials be moisture and oxygen impermeable as much as possible. The sealing substrate 604 may be made of a glass substrate, a quartz substrate, or a plastic substrate made of FRP (Fiber Reinforced Plastics), PVF (Polyvinyl Fluoride), polyester, acrylic resin, or the like.

[0337] Although not shown in Figures 6A and 6B, a protective film may be provided on the second electrode. The protective film may be formed of an organic resin film or an inorganic insulating film. The protective film may also be formed so as to cover the exposed portion of the sealing material 605. The protective film may also be provided so as to cover the surfaces and side surfaces of the pair of substrates, the exposed side surfaces of the sealing layer, the insulating layer, etc.

[0338] The protective film can be made of a material that is impermeable to impurities such as water, and therefore can effectively prevent impurities such as water from diffusing from the outside to the inside.

[0339] The protective film may be made of an oxide, nitride, fluoride, sulfide, ternary compound, metal, polymer, or the like. For example, a material containing aluminum oxide, hafnium oxide, hafnium 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, indium oxide, or the like; a material containing aluminum nitride, hafnium nitride, silicon nitride, tantalum nitride, titanium nitride, niobium nitride, molybdenum nitride, zirconium nitride, gallium nitride, or the like; a nitride containing titanium and aluminum; an oxide containing titanium and aluminum; an oxide containing aluminum and zinc; a sulfide containing manganese and zinc; a sulfide containing cerium and strontium; an oxide containing erbium and aluminum; or an oxide containing yttrium and zirconium.

[0340] The protective film is preferably formed using a film formation method that provides good step coverage. One such method is atomic layer deposition (ALD). It is preferable to use a material that can be formed using the ALD method for the protective film. By using the ALD method, it is possible to form a dense protective film with reduced defects such as cracks or pinholes, or with a uniform thickness. Furthermore, it is possible to reduce damage to the workpiece when forming the protective film.

[0341] For example, by forming a protective film using the ALD method, it is possible to form a uniform protective film with few defects on a surface having a complex uneven shape or on the top, side and back surfaces of a touch panel.

[0342] In this manner, a light-emitting device manufactured using the light-emitting device described in any one of Embodiments 1 to 4 can be obtained.

[0343] The light-emitting device in this embodiment can have favorable characteristics because it uses the light-emitting device described in any one of Embodiments 1 to 4. Specifically, the light-emitting device described in any one of Embodiments 1 to 4 has favorable emission efficiency, and therefore can have low power consumption.

[0344] 7A shows an example of a full-color light-emitting device in which a light-emitting device that emits white light is formed and a colored layer (color filter) is provided, etc. 7A shows a substrate 1001, a base insulating film 1002, a gate insulating film 1003, a gate electrode 1006, a gate electrode 1007, a gate electrode 1008, a first interlayer insulating film 1020, a second interlayer insulating film 1021, a peripheral portion 1042, a pixel portion 1040, a driver circuit portion 1041, an electrode 1024W, an electrode 1024R, an electrode 1024G, an electrode 1024B of the light-emitting device, a partition wall 1025, an EL layer 1028, an electrode 1029 of the light-emitting device, a sealing substrate 1031, a sealant 1032, etc.

[0345] 7A , the colored layers (red colored layer 1034R, green colored layer 1034G, and blue colored layer 1034B) are provided on a transparent substrate 1033. A black matrix 1035 may also be provided. The transparent substrate 1033 on which the colored layers and black matrix are provided is aligned and fixed to the substrate 1001. The colored layers and black matrix 1035 are covered with an overcoat layer 1036. Also, in FIG. 7A , there are light-emitting layers from which light does not pass through the colored layers and exits to the outside, and light-emitting layers from which light passes through the colored layers of each color and exits to the outside. Light that does not pass through the colored layers is white, and light that passes through the colored layers is red, green, and blue, so that an image can be expressed using four color pixels.

[0346] 7B shows an example in which colored layers (a red colored layer 1034R, a green colored layer 1034G, and a blue colored layer 1034B) are formed between the gate insulating film 1003 and the first interlayer insulating film 1020. In this manner, the colored layers may be provided between the substrate 1001 and the sealing substrate 1031.

[0347] Furthermore, the light-emitting device described above has a structure (bottom emission type) in which light is extracted from the substrate 1001 side on which the FET is formed, but a structure (top emission type) in which light is extracted from the sealing substrate 1031 side may also be used. A cross-sectional view of a top emission type light-emitting device is shown in FIG. 8 . In this case, a light-opaque substrate can be used as the substrate 1001. The process is the same as for a bottom emission type light-emitting device until a connection electrode connecting the FET and the anode of the light-emitting device is formed. Thereafter, a third interlayer insulating film 1037 is formed to cover the electrode 1022. This insulating film may also serve as a planarizing film. The third interlayer insulating film 1037 can be formed using the same material as the second interlayer insulating film, as well as other known materials.

[0348] Although the electrodes 1024W, 1024R, 1024G, and 1024B of the light-emitting device are anodes here, they may be cathodes. In addition, in the case of a top-emission light-emitting device as shown in FIG. 8 , the electrodes 1024W, 1024R, 1024G, and 1024B are preferably reflective electrodes. The EL layer 1028 has a structure similar to that described as the unit 103 in any one of Embodiments 1 to 4, and has an element structure that can emit white light.

[0349] In the top-emission structure shown in FIG. 8 , sealing can be performed using a sealing substrate 1031 provided with colored layers (a red colored layer 1034R, a green colored layer 1034G, and a blue colored layer 1034B). A black matrix 1035 may be provided on the sealing substrate 1031 so as to be positioned between pixels. The colored layers (the red colored layer 1034R, the green colored layer 1034G, and the blue colored layer 1034B) or the black matrix may be covered with an overcoat layer 1036. Note that a light-transmitting substrate is used as the sealing substrate 1031. While an example of full-color display using four colors, red, green, blue, and white, is shown here, this is not particularly limited, and full-color display using four colors, red, yellow, green, and blue, or three colors, red, green, and blue, may also be performed.

[0350] A microcavity structure is suitable for use in top-emission light-emitting devices. A light-emitting device with a microcavity structure can be obtained by using a reflective electrode as the first electrode and a semi-transparent / semi-reflective electrode as the second electrode. At least an EL layer is provided between the reflective electrode and the semi-transparent / semi-reflective electrode, and at least a light-emitting layer that serves as a light-emitting region is provided.

[0351] The reflectance of the reflective electrode to visible light is 40% to 100%, preferably 70% to 100%, and the resistivity is 1×10 −２ The semi-transmitting and semi-reflective electrode has a visible light reflectance of 20% to 80%, preferably 40% to 70%, and a resistivity of 1×10 −２ It is assumed that the film has a resistivity of Ωcm or less.

[0352] Light emitted from the light-emitting layer included in the EL layer is reflected by the reflective electrode and the semi-transmissive and semi-reflective electrode, causing resonance.

[0353] In the light-emitting device, the optical distance between the reflective electrode and the semi-transmitting / semi-reflective electrode can be changed by changing the thickness of the transparent conductive film or the above-mentioned composite material, carrier transport material, etc. This makes it possible to intensify light of a resonant wavelength and attenuate light of a non-resonant wavelength between the reflective electrode and the semi-transmitting / semi-reflective electrode.

[0354] Note that, since the light reflected by the reflective electrode and returned (first reflected light) significantly interferes with the light (first incident light) that directly enters the semi-transmissive / semi-reflective electrode from the light-emitting layer, it is preferable to adjust the optical distance between the reflective electrode and the light-emitting layer to (2n-1)λ / 4 (where n is a natural number of 1 or more, and λ is the wavelength of the light emission to be amplified). By adjusting the optical distance, the phases of the first reflected light and the first incident light can be matched, thereby further amplifying the light emission from the light-emitting layer.

[0355] In the above configuration, the EL layer may have a structure having multiple light-emitting layers or a structure having a single light-emitting layer. For example, it may be combined with the above-mentioned tandem light-emitting device configuration, in which multiple EL layers are provided in one light-emitting device with a charge-generating layer sandwiched therebetween, and one or more light-emitting layers are formed in each EL layer.

[0356] The microcavity structure makes it possible to increase the light emission intensity of a specific wavelength in the front direction, thereby reducing power consumption. In the case of a light-emitting device that displays images using four sub-pixels of red, yellow, green, and blue, the yellow light emission has the effect of improving brightness, and the microcavity structure that matches the wavelength of each color can be applied to all sub-pixels, resulting in a light-emitting device with good characteristics.

[0357] The light-emitting device in this embodiment can have favorable characteristics because it uses the light-emitting device described in any one of Embodiments 1 to 4. Specifically, the light-emitting device described in any one of Embodiments 1 to 4 has favorable emission efficiency, and therefore can have low power consumption.

[0358] Up to this point, active matrix light-emitting devices have been described. From now on, passive matrix light-emitting devices will be described. FIG. 9 shows a passive matrix light-emitting device manufactured by applying the present invention. FIG. 9A is a perspective view showing the light-emitting device, and FIG. 9B is a cross-sectional view taken along X-Y line in FIG. 9A. In FIG. 9, an EL layer 955 is provided between an electrode 952 and an electrode 956 on a substrate 951. An end of the electrode 952 is covered with an insulating layer 953. A partition layer 954 is provided on the insulating layer 953. The sidewalls of the partition layer 954 are inclined such that the distance between one sidewall and the other sidewall becomes narrower as the sidewall approaches the substrate surface. That is, the cross section of the partition layer 954 in the short side direction is trapezoidal, and the bottom side (the side facing the same direction as the surface of the insulating layer 953 and in contact with the insulating layer 953) is shorter than the top side (the side facing the same direction as the surface of the insulating layer 953 and not in contact with the insulating layer 953). By providing the partition layer 954 in this manner, defects in the light-emitting device due to static electricity or the like can be prevented. Furthermore, a passive matrix light-emitting device using the light-emitting device described in any one of Embodiments 1 to 4 can be a highly reliable light-emitting device or a light-emitting device with low power consumption.

[0359] The light emitting device described above is capable of individually controlling a large number of minute light emitting devices arranged in a matrix, and is therefore suitable for use as a display device for displaying images.

[0360] This embodiment mode can be freely combined with other embodiment modes.

[0361] In this embodiment, an example in which the light-emitting device described in any one of Embodiments 1 to 4 is used as a lighting device will be described with reference to Fig. 10. Fig. 10B is a top view of the lighting device, and Fig. 10A is a cross-sectional view taken along the line e-f in Fig. 10B.

[0362] In the lighting device in this embodiment, a first electrode 401 is formed over a light-transmitting substrate 400 which serves as a support. The first electrode 401 corresponds to the electrode 101 in any one of Embodiments 1 to 4. When light is extracted from the first electrode 401 side, the first electrode 401 is formed using a light-transmitting material.

[0363] A pad 412 for supplying a voltage to the second electrode 404 is formed on the substrate 400 .

[0364] An EL layer 403 is formed over the first electrode 401. The EL layer 403 corresponds to a combination of the layer 104, the unit 103, and the layer 105, or a combination of the layer 104, the unit 103, the intermediate layer 106, the unit 103_2, and the layer 105 in any one of Embodiments 1 to 4. For details of these structures, see the relevant descriptions.

[0365] A second electrode 404 is formed to cover the EL layer 403. The second electrode 404 corresponds to the electrode 102 in any one of Embodiments 1 to 4. When light is extracted from the first electrode 401 side, the second electrode 404 is formed using a material with high reflectivity. The second electrode 404 is connected to a pad 412 to supply a voltage.

[0366] As described above, the lighting device described in this embodiment has a light-emitting device including the first electrode 401, the EL layer 403, and the second electrode 404. Since the light-emitting device has high emission efficiency, the lighting device in this embodiment can have low power consumption.

[0367] The substrate 400 on which the light-emitting device having the above structure is formed is fixed to and sealed by a sealing substrate 407 using a sealing material 405 and a sealing material 406, thereby completing the lighting device. Either the sealing material 405 or the sealing material 406 may be used alone. A desiccant may also be mixed into the inner sealing material 406 (not shown in FIG. 10B ), which allows it to absorb moisture and improve reliability.

[0368] Furthermore, the pad 412 and a part of the first electrode 401 can be provided as an external input terminal by extending them outside the sealing materials 405 and 406. An IC chip 420 or the like on which a converter or the like is mounted may also be provided thereon.

[0369] As described above, the lighting device described in this embodiment uses the light-emitting device described in any one of Embodiments 1 to 4 as an EL element, and can be a lighting device with low power consumption.

[0370] Embodiment 9 In this embodiment, an example of an electronic device including the light-emitting device described in any one of Embodiments 1 to 4 as a part thereof will be described. The light-emitting device described in any one of Embodiments 1 to 4 has good light-emitting efficiency and low power consumption. As a result, the electronic device described in this embodiment can be an electronic device having a light-emitting portion with low power consumption.

[0371] Examples of electronic devices to which the light-emitting devices are applied include television sets (also called televisions or television receivers), computer monitors, digital cameras, digital video cameras, digital photo frames, mobile phones (also called mobile phones or mobile phone devices), portable game machines, personal digital assistants, sound reproducing devices, large game machines such as pachinko machines, etc. Specific examples of these electronic devices are shown below.

[0372] 11A illustrates an example of a television set. The television set has a display portion 7103 incorporated in a housing 7101. Here, the housing 7101 is supported by a stand 7105. Images can be displayed on the display portion 7103, and the display portion 7103 includes light-emitting devices described in any one of Embodiments 1 to 4 arranged in a matrix.

[0373] The television set can be operated using operation switches on the housing 7101 or a separate remote control 7110. Channels or volume can be controlled using operation keys 7109 on the remote control 7110, and images displayed on the display portion 7103 can be controlled. A display portion 7107 may be provided on the remote control 7110 to display information to be output.

[0374] The television device is configured to include a receiver, a modem, etc. The receiver can receive general television broadcasts, and by connecting to a wired or wireless communication network via the modem, it is also possible to perform one-way (from sender to receiver) or two-way (between sender and receiver, or between receivers, etc.) information communication.

[0375] FIG. 11B shows a computer including a main body 7201, a housing 7202, a display portion 7203, a keyboard 7204, an external connection port 7205, a pointing device 7206, and the like. Note that this computer is manufactured by using the light-emitting devices described in any one of Embodiments 1 to 4 arranged in a matrix for the display portion 7203. The computer in FIG. 11B may have a configuration as shown in FIG. 11C. The computer in FIG. 11C is provided with a second display portion 7210 instead of the keyboard 7204 and the pointing device 7206. The second display portion 7210 is a touch panel type, and input can be performed by operating an input display displayed on the second display portion 7210 with a finger or a dedicated pen. The second display portion 7210 can display not only an input display but also other images. The display portion 7203 may also be a touch panel. The two screens are connected by a hinge, which can prevent problems such as scratches or breakage of the screens during storage or transportation.

[0376] 11D illustrates an example of a mobile terminal. The mobile terminal includes a display portion 7402 incorporated in a housing 7401, operation buttons 7403, an external connection port 7404, a speaker 7405, a microphone 7406, and the like. Note that the mobile terminal includes the display portion 7402 in which the light-emitting devices described in any one of Embodiments 1 to 4 are arranged in a matrix.

[0377] 11D can be configured so that information can be input by touching the display portion 7402 with a finger or the like. In this case, operations such as making a call or creating an email can be performed by touching the display portion 7402 with a finger or the like.

[0378] The screen of the display portion 7402 has three main modes. The first is a display mode mainly for displaying images, the second is an input mode mainly for inputting information such as characters, and the third is a display+input mode that combines the display mode and the input mode.

[0379] For example, when making a call or creating an email, the display portion 7402 may be set to a character input mode mainly for inputting characters, and characters displayed on the screen may be input. In this case, it is preferable to display a keyboard or number buttons on most of the screen of the display portion 7402.

[0380] In addition, by providing a detection device having a sensor that detects tilt, such as a gyro sensor or an acceleration sensor, inside the mobile terminal, the orientation of the mobile terminal (portrait or landscape) can be determined and the screen display of the display portion 7402 can be automatically switched.

[0381] The screen mode can be switched by touching the display portion 7402 or by operating the operation buttons 7403 on the housing 7401. The screen mode can also be switched depending on the type of image displayed on the display portion 7402. For example, if the image signal to be displayed on the display portion is moving image data, the display mode is selected, and if it is text data, the input mode is selected.

[0382] In addition, in the input mode, a signal detected by an optical sensor in the display portion 7402 may be detected, and if there is no input by touch operation on the display portion 7402 for a certain period of time, the screen mode may be controlled to switch from the input mode to the display mode.

[0383] The display portion 7402 can also function as an image sensor. For example, personal authentication can be performed by touching the display portion 7402 with a palm or a finger to capture an image of a palm print, a fingerprint, or the like. Furthermore, by using a backlight that emits near-infrared light or a sensing light source that emits near-infrared light for the display portion, finger veins, palm veins, or the like can also be captured.

[0384] FIG. 12A is a schematic diagram showing an example of a cleaning robot.

[0385] The cleaning robot 5100 has a display 5101 arranged on its top surface, multiple cameras 5102 arranged on its side, a brush 5103, and an operation button 5104. Although not shown, the cleaning robot 5100 is also provided with tires, a suction port, and the like on its bottom surface. The cleaning robot 5100 is also provided with various other sensors, such as an infrared sensor, an ultrasonic sensor, an acceleration sensor, a piezoelectric sensor, an optical sensor, and a gyro sensor. The cleaning robot 5100 is also provided with wireless communication means.

[0386] The cleaning robot 5100 can move by itself, detect dust 5120, and suck up the dust from a suction port provided on the bottom surface.

[0387] The cleaning robot 5100 can also analyze the image captured by the camera 5102 to determine whether there are any obstacles such as walls, furniture, or steps. If the image analysis detects an object that may become tangled in the brush 5103, such as a wire, the cleaning robot 5100 can stop the rotation of the brush 5103.

[0388] The display 5101 can display the remaining battery level, the amount of dust that has been sucked up, etc. The path traveled by the cleaning robot 5100 may be displayed on the display 5101. The display 5101 may also be a touch panel, and an operation button 5104 may be provided on the display 5101.

[0389] The cleaning robot 5100 can communicate with a portable electronic device 5140 such as a smartphone. Images captured by the camera 5102 can be displayed on the portable electronic device 5140. This allows the owner of the cleaning robot 5100 to know the state of the room even when they are away from home. In addition, the display on the display 5101 can be confirmed on the portable electronic device 5140 such as a smartphone.

[0390] The light-emitting device of one embodiment of the present invention can be used for the display 5101 .

[0391] The robot 2100 shown in FIG. 12B includes a computing device 2110, an illuminance sensor 2101, a microphone 2102, an upper camera 2103, a speaker 2104, a display 2105, a lower camera 2106, an obstacle sensor 2107, and a movement mechanism 2108.

[0392] The microphone 2102 has a function of detecting the user's voice, environmental sounds, etc. The speaker 2104 has a function of emitting sound. The robot 2100 can communicate with the user using the microphone 2102 and the speaker 2104.

[0393] The display 2105 has a function of displaying various information. The robot 2100 can display information desired by the user on the display 2105. The display 2105 may be equipped with a touch panel. The display 2105 may also be a detachable information terminal, which can be installed in a fixed position on the robot 2100 to enable charging and data transfer.

[0394] The upper camera 2103 and the lower camera 2106 have a function of capturing images of the surroundings of the robot 2100. In addition, the obstacle sensor 2107 can detect the presence or absence of an obstacle in the moving direction when the robot 2100 moves forward using the moving mechanism 2108. The robot 2100 can recognize the surrounding environment and move safely using the upper camera 2103, the lower camera 2106, and the obstacle sensor 2107. The light-emitting device of one embodiment of the present invention can be used for the display 2105.

[0395] 12C is a diagram showing an example of a goggle-type display. The goggle-type display includes, for example, a housing 5000, a display unit 5001, a speaker 5003, an LED lamp 5004, operation keys (including a power switch or an operation switch), a connection terminal 5006, a sensor 5007 (having a function of measuring force, displacement, position, velocity, acceleration, angular velocity, rotation speed, distance, light, liquid, magnetism, temperature, chemical substance, sound, time, hardness, electric field, current, voltage, power, radiation, flow rate, humidity, gradient, vibration, odor, or infrared light), a microphone 5008, a display unit 5002, a support unit 5012, and earphones 5013.

[0396] The light-emitting device of one embodiment of the present invention can be used for the display portion 5001 and the display portion 5002 .

[0397] 13 shows an example in which the light-emitting device described in any one of Embodiments 1 to 4 is used in a desk lamp, which is a lighting device. The desk lamp shown in FIG. 13 includes a housing 2001 and a light source 2002, and the lighting device described in Embodiment 8 may be used as the light source 2002.

[0398] 14 shows an example in which the light-emitting device described in any one of Embodiments 1 to 4 is used as an indoor lighting device 3001. Since the light-emitting device described in any one of Embodiments 1 to 4 has high emission efficiency, the lighting device can have low power consumption. Furthermore, since the light-emitting device described in any one of Embodiments 1 to 4 can be made large, it can be used as a large-area lighting device. Furthermore, since the light-emitting device described in any one of Embodiments 1 to 4 is thin, it can be used as a thin lighting device.

[0399] The light-emitting device described in any one of Embodiments 1 to 4 can also be mounted on a windshield or a dashboard of an automobile. Figure 15 shows one mode in which the light-emitting device described in any one of Embodiments 1 to 4 is used on a windshield or a dashboard of an automobile. Display regions 5200 to 5203 are display regions provided using the light-emitting device described in any one of Embodiments 1 to 4.

[0400] The display region 5200 and the display region 5201 are display devices provided on the windshield of an automobile, and are equipped with the light-emitting device described in any one of Embodiments 1 to 4. The light-emitting device described in any one of Embodiments 1 to 4 can be a so-called see-through display device, in which the opposite side can be seen through, by forming the first electrode and the second electrode using light-transmitting electrodes. A see-through display can be installed on the windshield of an automobile without obstructing the view. When a transistor or the like for driving is provided, a light-transmitting transistor such as an organic transistor made of an organic semiconductor material or a transistor using an oxide semiconductor is preferably used.

[0401] The display area 5202 is a display device provided on a pillar and incorporating the light-emitting device described in any one of Embodiments 1 to 4. The display area 5202 can complement the view blocked by the pillar by displaying an image from an imaging means provided on the vehicle body. Similarly, the display area 5203 provided on the dashboard can complement the view blocked by the vehicle body by displaying an image from an imaging means provided on the outside of the vehicle, thereby compensating for blind spots and improving safety. Displaying an image to complement the invisible part allows a driver to check for safety more naturally and without discomfort.

[0402] The display area 5203 can provide various information by displaying navigation information, speed or revolutions, mileage, remaining fuel, gear status, air conditioning settings, etc. The display items or layout can be changed as appropriate to suit the user's preferences. Note that this information can also be provided in the display areas 5200 to 5202. The display areas 5200 to 5203 can also be used as lighting devices.

[0403] 16A to 16C show a foldable portable information terminal 9310. Fig. 16A shows the portable information terminal 9310 in an unfolded state. Fig. 16B shows the portable information terminal 9310 in a state in the process of changing from one of the unfolded state and the folded state to the other. Fig. 16C shows the portable information terminal 9310 in a folded state. The portable information terminal 9310 has excellent portability in a folded state, and has excellent display visibility due to a seamless, wide display area in an unfolded state.

[0404] The display panel 9311 is supported by three housings 9315 connected by hinges 9313. Note that the display panel 9311 may be a touch panel (input / output device) equipped with a touch sensor (input device). Furthermore, the display panel 9311 can be reversibly transformed from an unfolded state to a folded state by bending the two housings 9315 via the hinges 9313. The light-emitting device of one embodiment of the present invention can be used for the display panel 9311.

[0405] Note that the structure described in this embodiment mode can be used by appropriately combining the structures described in any of Embodiment Modes 1 to 4.

[0406] As described above, the light-emitting device having the light-emitting device described in any one of Embodiments 1 to 4 has a very wide range of application, and the light-emitting device can be applied to electronic devices in a variety of fields. By using the light-emitting device described in any one of Embodiments 1 to 4, electronic devices with low power consumption can be obtained.

[0407] Note that this embodiment mode can be appropriately combined with other embodiment modes described in this specification.

[0408] In this example, a light-emitting device 1 and a light-emitting device 2 according to one embodiment of the present invention will be described with reference to FIGS.

[0409] FIG. 17 is a diagram illustrating the configuration of the light-emitting device 150. As shown in FIG.

[0410] FIG. 18 is a diagram illustrating the current density-luminance characteristics of the light-emitting device 1 and the light-emitting device 2. In FIG.

[0411] FIG. 19 is a diagram illustrating the luminance-current efficiency characteristics of the light-emitting device 1 and the light-emitting device 2. In FIG.

[0412] FIG. 20 is a diagram illustrating the voltage-luminance characteristics of the light-emitting device 1 and the light-emitting device 2. In FIG.

[0413] FIG. 21 is a diagram illustrating the voltage-current characteristics of the light-emitting device 1 and the light-emitting device 2. In FIG.

[0414] FIG. 22 is a diagram illustrating the luminance-blue index characteristics of the light-emitting device 1 and the light-emitting device 2. In FIG.

[0415] FIG. 23 shows the light emitting device 1 and the light emitting device 2 at 1000 cd / m ２ 10 is a diagram illustrating an emission spectrum when light is emitted at a luminance of 1000 .mu.m.

[0416] FIG. 24 shows the current density at 50 mA / cm ２ 1 is a graph showing the change over time in normalized luminance when light-emitting device 1 and light-emitting device 2 are caused to emit light at a constant current density of 1000 .mu.m.

[0417] Light-Emitting Device 1 The light-emitting device 1 fabricated in this example has a configuration similar to that of the light-emitting device 150 (see FIG. 17 ). The light-emitting device 150 includes an electrode 101, an electrode 102, a unit 103, and a layer 104. The unit 103 is sandwiched between the electrodes 101 and 102, and includes layers 111, 112, and 113. The layer 111 is sandwiched between the layers 112 and 113, and includes a light-emitting material. The layer 113 is sandwiched between the layer 111 and the electrode 102, and includes the organic compound BPM. The organic compound BPM includes a π-electron-deficient heteroaromatic ring skeleton and a π-electron-rich heteroaromatic ring skeleton. The layer 113 includes a layer 113(1) and a layer 113(2), and the layer 112 includes a layer 112(1) and a layer 112(2). The layer 104 is sandwiched between the electrode 551 and the unit 103, the layer 104 is in contact with the electrode 101, and contains an organic compound HM1 and an organic compound AM1. The organic compound AM1 has an electron accepting property with respect to the organic compound HM1, and the layer 104 has an electron accepting property of 1×10 ４ [Ω・cm] or more 1×10 ７ It has a resistivity of [Ω·cm] or less.

[0418] <Configuration of Light-Emitting Device 1> The configuration of light-emitting device 1 is shown in Table 1. The structural formulas of the materials used in the light-emitting device described in this example are shown below. Note that in the tables of this example, subscripts and superscripts are written in standard size for convenience. For example, subscripts used for abbreviations and superscripts used for units are written in standard size in the tables. These descriptions in the tables can be interpreted in accordance with the descriptions in the specification.

[0419]

[0420]

[0421] <<Method of Fabricating Light-Emitting Device 1>> The light-emitting device 1 described in this example was fabricated using a method including the following steps.

[0422] [First Step] In the first step, a reflective film REF was formed by sputtering using silver (Ag) as a target.

[0423] The reflective film REF contains Ag and has a thickness of 100 nm.

[0424] [Second Step] In the second step, the electrode 101 was formed on the reflective film REF. Specifically, the electrode 101 was formed by a sputtering method using an indium oxide-tin oxide (abbreviated as ITSO) target containing silicon or silicon oxide.

[0425] The electrode 101 includes ITSO, has a thickness of 85 nm, and is 4 mm ２ It has an area of ​​(2 mm x 2 mm).

[0426] Next, the substrate on which the electrode 101 was formed was washed with water, baked at 200° C. for 1 hour, and then subjected to UV ozone treatment for 370 seconds. −４ The substrate was introduced into a vacuum deposition apparatus whose internal pressure had been reduced to about Pa, and vacuum baking was performed at 170° C. for 30 minutes in a heating chamber of the vacuum deposition apparatus. Thereafter, the substrate was allowed to cool for about 30 minutes.

[0427] [Third Step] In the third step, a layer 104 was formed on the electrode 101. Specifically, materials were co-evaporated using a resistance heating method.

[0428] The layer 104 contains N,N-bis(4-biphenyl)-6-phenylbenzo[b]naphtho[1,2-d]furan-8-amine (abbreviation: BBABnf) and an electron-accepting material (abbreviation: OCHD-003) in a weight ratio of BBABnf:OCHD-003 = 1:0.1, and has a thickness of 10 nm. The HOMO level of BBABnf is -5.6 eV (see FIG. 17B). The electron-accepting material OCHD-003 contains fluorine and has a molecular weight of 672.

[0429] [Fourth Step] In the fourth step, a layer 112(1) was formed on the layer 104. Specifically, a material was evaporated using a resistance heating method.

[0430] Note that layer 112(1) contains BBABnf and has a thickness of 20 nm.

[0431] [Fifth Step] In the fifth step, a layer 112(2) was formed on the layer 112(1). Specifically, materials were evaporated using a resistance heating method.

[0432] The layer 112(2) contains 3,3′-(naphthalene-1,4-diyl)bis(9-phenyl-9H-carbazole) (abbreviation: PCzN2) and has a thickness of 10 nm.

[0433] [Sixth Step] In the sixth step, the layer 111 was formed on the layer 112(2). Specifically, materials were co-evaporated by using a resistance heating method.

[0434] The layer 111 contains 9-(1-naphthyl)-10-[4-(2-naphthyl)phenyl]anthracene (abbreviation: αN-βNPAnth) and 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 αN-βNPAnth:3,10PCA2Nbf(IV)-02=1:0.015, and has a thickness of 25 nm.

[0435] [Seventh Step] In the seventh step, a layer 113(1) was formed on the layer 111. Specifically, a material was evaporated using a resistance heating method.

[0436] The layer 113(1) contains 2-[4'-(9-phenyl-9H-carbazol-3-yl)-3,1'-biphenyl-1-yl]dibenzo[f,h]quinoxaline (abbreviation: 2mpPCBPDBq) and has a thickness of 20 nm.

[0437] 2mpPCBPDBq has a carbazole skeleton. 2mpPCBPDBq also has a HOMO level in the range of −6.0 eV to −5.6 eV (see FIG. 17B ). This facilitates the movement of holes from layer 111 to layer 113(1). Furthermore, the region contributing to light emission near layer 111 can be appropriately expanded.

[0438] [Eighth Step] In the eighth step, a layer 113(2) was formed on the layer 113(1). Specifically, materials were evaporated using a resistance heating method.

[0439] The layer 113(2) contains 2,9-di(2-naphthyl)-4,7-diphenyl-1,10-phenanthroline (abbreviation: NBPhen) and has a thickness of 10 nm.

[0440] [Ninth Step] In the ninth step, the layer 105 was formed on the layer 113(2). Specifically, the material was evaporated using a resistance heating method.

[0441] The layer 105 contains LiF and has a thickness of 1 nm.

[0442] [Tenth Step] In the tenth step, the electrode 102 was formed on the layer 105. Specifically, materials were co-evaporated using a resistance heating method.

[0443] The electrode 102 contains Ag and Mg at a volume ratio of Ag:Mg=1:0.1, and has a thickness of 15 nm.

[0444] [Eleventh Step] In the eleventh step, a layer CAP was formed on the electrode 102. Specifically, a material was evaporated by using a resistance heating method.

[0445] The layer CAP contains 4,4′,4″-(benzene-1,3,5-triyl)tri(dibenzothiophene) (abbreviation: DBT3P-II) and has a thickness of 80 nm.

[0446] <<Operating Characteristics of Light-Emitting Device 1>> When power was supplied, the light-emitting device 1 emitted light EL1 (see FIG. 17). The operating characteristics of the light-emitting device 1 were measured at room temperature (see FIGS. 18 to 24). Note that a spectroradiometer (SR-UL1R, manufactured by Topcon Corporation) was used to measure the luminance, CIE chromaticity, and emission spectrum. Table 2 also lists the characteristics of other light-emitting devices, the configurations of which will be described later.

[0447] The fabricated light-emitting device had a brightness of 1000 cd / m ２ Table 2 shows the main initial characteristics and the results of reliability tests when the device was made to emit light at about 1000 kJ / s.

[0448] The blue index (BI) is one of the indices that represent the characteristics of a blue light-emitting device, and is a value obtained by dividing the current efficiency (cd / A) by the y chromaticity. Generally, blue light with high color purity is useful for expressing a wide color gamut. Furthermore, the higher the color purity of blue light, the smaller the y chromaticity tends to be. Thus, the value obtained by dividing the current efficiency (cd / A) by the y chromaticity serves as an index showing the usefulness of a blue light-emitting device. In other words, a blue light-emitting device with a high BI is suitable for realizing a display device with a wide color gamut and high efficiency.

[0449] The light-emitting device was heated at a constant current density (50 mA / cm ２ The reliability was evaluated by emitting light at 310 hours (see FIG. 24). The ratio of the luminance after 310 hours to the initial luminance was used for evaluation.

[0450]

[0451] It was found that the light-emitting device 1 exhibited excellent characteristics. For example, the light-emitting device 1 exhibited higher reliability than the comparative light-emitting devices 1 and 2. 2mpPCBPDBq has a carbazole skeleton that exhibits hole transport properties and has a HOMO level of −5.81 eV. The αN-βNPAnth used in the layer 111 has a HOMO level of −5.85 eV. Holes are easily transferred from the layer 111 using αN-βNPAnth to the layer 113(1) using 2mpPCBPDBq because the transfer is from a deep HOMO level to a shallow HOMO level. Furthermore, hole accumulation between the layer 111 and the layer 113(1) can be reduced.

[0452] <Light-Emitting Device 2> The light-emitting device 2 fabricated in this example has the same configuration as the light-emitting device 150 (see FIG. 17).

[0453] <Configuration of Light-Emitting Device 2> The configuration of the light-emitting device 2 differs from the configuration of the light-emitting device 1 in the layer 113(1). Specifically, the light-emitting device 2 differs from the light-emitting device 1 in that the layer 113(1) contains 3-[3,5-di(carbazol-9-yl)phenyl]phenanthro[9,10-b]pyrazine (abbreviation: 2Cz2PDBq) instead of 2mpPCBPDBq.

[0454] <<Method of Fabricating Light-Emitting Device 2>> The light-emitting device 2 described in this example was fabricated using a method having the following steps.

[0455] The method for fabricating light-emitting device 2 differs from the method for fabricating light-emitting device 1 in that 2Cz2PDBq was used instead of 2mpPCBPDBq in the step of forming layer 113(1). Here, the differences will be described in detail, and the above description will be used for the parts where similar methods are used.

[0456] [Seventh Step] In the seventh step, a layer 113(1) was formed on the layer 111. Specifically, a material was evaporated using a resistance heating method.

[0457] The layer 113(1) contains 2Cz2PDBq and has a thickness of 20 nm.

[0458] <<Operating Characteristics of Light-Emitting Device 2>> When power was supplied, the light-emitting device 2 emitted light EL1 (see FIG. 17). The operating characteristics of the light-emitting device 2 were measured at room temperature (see FIGS. 18 to 24). The luminance, CIE chromaticity, and emission spectrum were measured using a spectroradiometer (SR-UL1R, manufactured by Topcon Corporation).

[0459] The fabricated light-emitting device had a brightness of 1000 cd / m ２ Table 2 shows the main initial characteristics and the results of reliability tests when the device was made to emit light at about 1000 kJ / s.

[0460] It was found that the light-emitting device 2 exhibited good characteristics. For example, the light-emitting device 2 exhibited higher reliability than the comparative light-emitting devices 1 and 2.

[0461] Reference Example A comparative light-emitting device 1 fabricated and described in this reference example has the same configuration as the light-emitting device 150 (see FIG. 17).

[0462] <Configuration of Comparative Light-Emitting Device 1> The configuration of comparative light-emitting device 1 differs from the configuration of light-emitting device 1 in the layers 113(1) and 113(2).

[0463] The layer 113(1) differs from the light-emitting device 1 in that it has a thickness of 10 nm instead of 20 nm. The layer 113(1) also differs from the light-emitting device 1 in that it contains 2-[3-(3'-dibenzothiophen-4-yl)biphenyl]dibenzo[f,h]quinoxaline (abbreviation: 2mDBTBPDBq-II) instead of 2mpPCBPDBq. 2mpPCBPDBq has a carbazole skeleton that exhibits hole transport properties and a HOMO level of -5.81 eV. On the other hand, 2mDBTBPDBq-II has a thiophene skeleton that exhibits hole transport properties but a HOMO level of -6.22 eV. The αN-βNPAnth used in the layer 111 has a HOMO level of -5.85 eV.

[0464] The transfer of holes from the layer 111 using αN-βNPAnth to the layer 113(1) using 2mDBTBPDBq-II is a transfer from a shallow HOMO level to a deep HOMO level, and is more difficult than the transfer of holes from the layer 111 using αN-βNPAnth to the layer 113(1) using 2mpPCBPDBq.

[0465] Layer 113(2) differs from light-emitting device 1 in that it has a thickness of 20 nm instead of 10 nm.

[0466] The structural formulas of the materials used in the comparative light-emitting device 1 described in this reference example are shown below.

[0467]

[0468] <<Method for Producing Comparative Light-Emitting Device 1>> Comparative light-emitting device 1 described in this example was produced using a method having the following steps.

[0469] The method for fabricating comparative light-emitting device 1 differs from the method for fabricating light-emitting device 1 in that the thickness of layer 113(1) was changed from 20 nm to 10 nm and that 2mDBTBPDBq-II was used instead of 2mpPCBPDBq. The method for fabricating comparative light-emitting device 1 also differs from the method for fabricating light-emitting device 1 in that the thickness of layer 113(2) was changed from 10 nm to 20 nm. Here, the differences will be described in detail, and the above description will be used for the parts where similar methods were used.

[0470] [Seventh Step] In the seventh step, a layer 113(1) was formed on the layer 111. Specifically, a material was evaporated using a resistance heating method.

[0471] The layer 113(1) contains 2mDBTBPDBq-II and has a thickness of 10 nm.

[0472] [Eighth Step] In the eighth step, a layer 113(2) was formed on the layer 113(1). Specifically, materials were evaporated using a resistance heating method.

[0473] The layer 113(2) contains NBPhen and has a thickness of 20 nm.

[0474] <Configuration of Comparative Light-Emitting Device 2> The configuration of comparative light-emitting device 2 differs from the configuration of light-emitting device 1 in the layer 113(1) and the layer 113(2).

[0475] Layer 113(1) differs from light-emitting device 1 in that it contains 2-{4-[9,10-di(2-naphthyl)-2-anthryl]phenyl}-1-phenyl-1H-benzimidazole (abbreviation: ZADN) and 8-quinolinolato-lithium (abbreviation: Liq) in a weight ratio of 1:1 instead of 2mpPCBPDBq. ZADN has an imidazole skeleton, which is a π-electron-deficient heteroaromatic ring skeleton, but does not have a π-electron-rich heteroaromatic ring skeleton.

[0476] The structural formulas of the materials used in the comparative light-emitting device 2 described in this reference example are shown below.

[0477]

[0478] <<Method for Producing Comparative Light-Emitting Device 2>> Comparative light-emitting device 2 described in this example was produced using a method including the following steps.

[0479] The method for fabricating comparative light-emitting device 2 differs from the method for fabricating light-emitting device 1 in that a material in which ZADN and Liq are mixed in a weight ratio of 1:1 is used instead of 2mpPCBPDBq in the step of forming layer 113(1). Here, the differences will be described in detail, and the above description will be used for the parts in which similar methods are used.

[0480] [Seventh Step] In the seventh step, a layer 113(1) was formed on the layer 111. Specifically, a material was evaporated using a resistance heating method.

[0481] The layer 113(1) contains ZADN and Liq in a weight ratio of ZADN:Liq=1:1 and has a thickness of 20 nm.

[0482] AM1: organic compound, BPM: organic compound, EL1: light, EL1_2: light, EL2: light, HM1: organic compound, HM2: organic compound, HOMO1: HOMO level, HOMO2: HMO level, HOMO3: HMO level, 101: electrode, 102: electrode, 103: unit, 103_2: unit, 103S: unit, 103X: unit, 103Y: unit, 104: layer, 104X: layer, 104XY: gap, 104Y: layer, 105: layer, 105_2: layer, 106: intermediate layer, 106_1: layer, 106_2: layer, 111: layer, 111X: layer, 111Y: layer, 112: layer, 112X: layer, 112Y: layer, 113: layer, 113X: layer, 113Y: layer, 114N: layer, 114P: layer, 114S: layer, 150: light-emitting device, 400: substrate, 401: electrode, 403: EL layer, 404: electrode, 405: sealing material, 406: sealing material, 407: sealing substrate, 412: pad, 420: IC chip, 521: insulating film, 528: insulating film, 550: light-emitting device, 550S: optical functional device, 550X: light-emitting device, 550Y: light-emitting device, 551: electrode, 551S: electrode, 551X: electrode, 551XY: gap, 551Y : electrode, 552: electrode, 573: insulating film, 573A: insulating film, 573B: insulating film, 601: source line driving circuit, 602: pixel portion, 603: gate line driving circuit, 604: sealing substrate, 605: sealing material, 607: space, 608: wiring, 610: element substrate, 611: switching FET, 612: current control FET, 613: electrode, 614: insulator, 616: EL layer, 617: electrode, 618: light emitting device, 623: FET, 700: functional panel, 951: substrate, 952: electrode, 953: insulating layer, 954: partition layer, 955: EL layer, 956: electrode, 1001 : substrate, 1002: base insulating film, 1003: gate insulating film, 1006: gate electrode, 1007: gate electrode, 1008: gate electrode, 1020: interlayer insulating film, 1021: interlayer insulating film, 1022: electrode, 1024B: electrode, 1024G: electrode, 1024R: electrode, 1024W: electrode, 1025: partition wall, 1028: EL layer, 1029: electrode, 1031: sealing substrate, 1032: sealing material, 1033: base material, 1034B: colored layer, 1034G: colored layer, 1034R: colored layer, 1035: black matrix, 1036: overcoat layer, 1037: interlayer insulating film,1040: pixel unit, 1041: driving circuit unit, 1042: peripheral unit, 2001: housing, 2002: light source, 2100: robot, 2101: illuminance sensor, 2102: microphone, 2103: upper camera, 2104: speaker, 2105: display, 2106: lower camera, 2107: obstacle sensor, 2108: movement mechanism, 2110: computing unit, 3001: lighting device, 5000: housing, 5001: display unit, 5002: display unit, 5003: speaker, 5004: LED lamp, 5006: connection terminal, 5007: sensor, 5008: microphone, 5012: support unit, 5013: earphone, 5100: cleaning robot, 5101: display, 5102: camera, 5103: brush , 5104: operation buttons, 5120: dust, 5140: portable electronic device, 5200: display area, 5201: display area, 5202: display area, 5203: display area, 7101: housing, 7103: display unit, 7105: stand, 7107: display unit, 7109: operation keys, 7110: remote control, 7201: main body, 7202: housing, 7203: display unit, 7204: keyboard, 7205: external connection port, 7206: pointing device, 7210: display unit, 7401: housing, 7402: display unit, 7403: operation buttons, 7404: external connection port, 7405: speaker, 7406: microphone, 9310: portable information terminal, 9311: display panel, 9313: hinge, 9315: housing,

Claims

1. A first electrode; A second electrode; and A first unit; a first layer; the first unit is sandwiched between the first electrode and the second electrode; the first unit comprises a second layer, a third layer and a fourth layer; the second layer is sandwiched between the third layer and the fourth layer; the second layer comprises a luminescent material; the fourth layer is sandwiched between the second layer and the second electrode; the fourth layer includes a first organic compound; the first organic compound has a π-electron deficient heteroaromatic ring skeleton and a π-electron rich heteroaromatic ring skeleton, the first layer is sandwiched between the first electrode and the first unit; the first layer is in contact with the first electrode; the first layer includes a second organic compound and a third organic compound; the third organic compound has an electron accepting property with respect to the second organic compound, The first layer is 1×10 ４ [Ω・cm] or more 1×10 ７ [Ω cm] or less, A light-emitting device that emits blue light.

2. In claim 1, the first organic compound has a first HOMO level; The first HOMO level is in the range of -6.0 eV to -5.6 eV.

3. In claim 1 or claim 2, The first organic compound comprises a diazine skeleton and a π-electron rich heteroaromatic skeleton.

4. In claim 1 or claim 2, The first organic compound comprises a π-electron deficient heteroaromatic ring skeleton and a carbazole skeleton.

5. In claim 1 or claim 2, The first organic compound is represented by the following general formula (G1): 【Chemistry 1】 (In the above general formula (G1), D represents a substituted or unsubstituted quinoxalinyl group; E represents a substituted or unsubstituted carbazolyl group; Ar represents a substituted or unsubstituted arylene group; The arylene group has 6 to 13 carbon atoms constituting the ring.

6. In claim 1 or claim 2, the third organic compound has a LUMO level of −5.0 eV or less; the second organic compound has a second HOMO level; the second HOMO level is in the range of -5.7 eV to -5.3 eV.

7. In claim 1 or claim 2, the first organic compound has a diazine skeleton and a π-electron-rich heteroaromatic ring skeleton, the third organic compound has a LUMO level of −5.0 eV or less; the second organic compound has a second HOMO level; the second HOMO level is in the range of -5.7 eV to -5.3 eV.

8. In claim 1 or claim 2, the first organic compound has a π-electron-deficient heteroaromatic ring skeleton and a carbazole skeleton, the third organic compound has a LUMO level of −5.0 eV or less; the second organic compound has a second HOMO level; the second HOMO level is in the range of -5.7 eV to -5.3 eV.

9. In claim 1 or claim 2, When the square root of the electric field strength [V / cm] is 600, the hole mobility of the second organic compound is 1×10 －３ cm / Vs or less.

10. In claim 1 or claim 2, the first organic compound has a diazine skeleton and a π-electron-rich heteroaromatic ring skeleton, When the square root of the electric field strength [V / cm] is 600, the hole mobility of the second organic compound is 1×10 －３ cm / Vs or less.

11. In claim 1 or claim 2, the first organic compound has a π-electron-deficient heteroaromatic ring skeleton and a carbazole skeleton, When the square root of the electric field strength [V / cm] is 600, the hole mobility of the second organic compound is 1×10 －３ cm / Vs or less.

12. In claim 1 or claim 2, the third organic compound has a LUMO level of −5.0 eV or less; the second organic compound has a second HOMO level; the second HOMO level is in the range of −5.7 eV to −5.3 eV, When the square root of the electric field strength [V / cm] is 600, the hole mobility of the second organic compound is 1×10 －３ cm / Vs or less.

13. In claim 1 or claim 2, the first organic compound has a diazine skeleton and a π-electron-rich heteroaromatic ring skeleton, the third organic compound has a LUMO level of −5.0 eV or less; the second organic compound has a second HOMO level; the second HOMO level is in the range of −5.7 eV to −5.3 eV, When the square root of the electric field strength [V / cm] is 600, the hole mobility of the second organic compound is 1×10 －３ cm / Vs or less.

14. In claim 1 or claim 2, The first layer is 5×10 ４ [Ω・cm] or more 1×10 ７ A light-emitting device having a resistivity of less than [Ω·cm].

15. In claim 1 or claim 2, the third organic compound has a LUMO level of −5.0 eV or less; the second organic compound has a second HOMO level; the second HOMO level is in the range of −5.7 eV to −5.3 eV, The first layer is 5×10 ４ [Ω・cm] or more 1×10 ７ A light-emitting device having a resistivity of less than [Ω·cm].

16. In claim 1 or claim 2, the third organic compound has a LUMO level of −5.0 eV or less; the second organic compound has a second HOMO level; the second HOMO level is in the range of −5.7 eV to −5.3 eV, the third layer is sandwiched between the first layer and the second layer; the third layer is in contact with the first layer; the third layer includes a fourth organic compound; the fourth organic compound has a third HOMO level; The third HOMO level is in the range of −0.2 eV to 0 eV with respect to the second HOMO level.

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