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

Abstract

To provide a novel light-emitting device, light-emitting apparatus, electronic appliance, display device, and illumination device with excellent convenience, usefulness, or reliability.SOLUTION: A light-emitting device includes a first electrode, a second electrode, a first layer, and a second layer. The second electrode includes a region overlapping with the first electrode. The first layer includes a region held between the first electrode and the second electrode. The first layer includes a light-emitting material. The light-emitting material has a function of emitting photoluminescence light in a solution. The photoluminescence light has a first spectrum. The first spectrum has a maximum peak at a wavelength λ1 and the wavelength λ1 is in the range of 440 nm or more and 470 nm or less. The second layer includes a region held between the first layer and the second electrode. The second layer includes a first organic compound. The first organic compound has a first refractive index n1 with respect to the light including the wavelength λ1. The first refractive index n1 is 1.4 or more and 1.75 or less.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] One embodiment of the present invention relates to a light-emitting device, an electronic device, a display device, a lighting device, or a semiconductor 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 relates to an object, a method, or a manufacturing method. Alternatively, one embodiment of the present invention relates to a process, a machine, a 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. [Background technology]

[0003] Light-emitting devices (organic EL devices) that utilize electroluminescence (EL) using organic compounds are becoming more and more 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 between them. By applying a voltage to this element, carriers (holes and electrons) are injected, and the recombination energy of these 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 be fabricated with a continuous two-dimensional light-emitting layer, enabling planar light emission, a feature that is difficult to achieve with point light sources such as incandescent bulbs or LEDs, or linear light sources such as fluorescent lamps, making them highly useful as surface light sources for lighting applications.

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

[0007] One of the problems often cited when discussing organic EL elements is their low light extraction efficiency. In particular, attenuation due to reflection caused by differences in the refractive index of adjacent layers is a major factor in reducing the efficiency of the element. To reduce this effect, a structure has been proposed in which a layer made of a low refractive index material is formed inside the EL layer (see, for example, Patent Document 1).

[0008] Light-emitting devices with this structure can have higher light extraction efficiency and therefore higher external quantum efficiency than light-emitting devices with conventional structures. However, it is not easy to form such a low-refractive-index layer within the EL layer without adversely affecting other important properties of the light-emitting device. This is because there is a trade-off between a low refractive index and high carrier transport properties or reliability when used in a light-emitting device. This problem arises because the carrier transport properties or reliability of organic compounds are largely due to the presence of unsaturated bonds, and organic compounds with many unsaturated bonds tend to have a high refractive index. [Prior art documents] [Patent documents]

[0009] [Patent Document 1] US Patent Application Publication No. 2020 / 0176692 Summary of the Invention [Problem to be solved by the invention]

[0010] 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 electronic 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 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 electronic device, a novel display device, a novel lighting device, or a novel semiconductor device.

[0011] 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. [Means for solving the problem]

[0012] (1) One embodiment of the present invention is a light-emitting device including a first electrode, a second electrode, and a unit.

[0013] The second electrode has an area overlapping with the first electrode, the unit has an area sandwiched between the first electrode and the second electrode, and the unit has a first layer and a second layer.

[0014] The first layer comprises an area sandwiched between the first electrode and the second electrode, and the first layer includes a light-emitting material.

[0015] The luminescent material has the function of emitting photoluminescent light in a solution, and the photoluminescent light has a first spectrum φ1, and the first spectrum φ1 has a maximum peak at a wavelength λ1, and the wavelength λ1 is in the range of 440 nm to 470 nm.

[0016] The second layer comprises an area sandwiched between the first layer and the second electrode, and the second layer includes a first organic compound, ETM.

[0017] The first organic compound ETM has a first refractive index n1 for light having a wavelength λ1, and the first refractive index n1 is 1.4 or more and 1.75 or less.

[0018] This allows the light emitted from the first layer to be extracted efficiently, or allows blue light to be extracted efficiently, resulting in a novel light-emitting device that is highly convenient, useful, and reliable.

[0019] (2) Another embodiment of the present invention is the light-emitting device, wherein the first spectrum φ1 has a full width at half maximum FWHM that is equal to or greater than 10 nm and equal to or less than 35 nm.

[0020] (3) Another embodiment of the present invention is the above light-emitting device, in which the second electrode contains silver.

[0021] This allows light emitted from the first layer to be extracted efficiently. Alternatively, blue light can be extracted efficiently. Alternatively, highly saturated light can be extracted efficiently. Alternatively, a microresonator structure can be formed using the second layer and the second electrode. Alternatively, the spectral width of the emitted light can be narrowed using the microresonator structure. Alternatively, light can be utilized with high efficiency even when the microresonator structure is used. As a result, a novel light-emitting device with excellent convenience, usefulness, and reliability can be provided.

[0022] (4) In addition, one aspect of the present invention is a method for manufacturing a compound represented by the following general formula (G e1 2) is the above light-emitting device.

[0023] [ka]

[0024] In addition, Q 1 ~Q 3 2 or 3 of the atoms are nitrogen atoms, and Q 1 ~Q 3 When two of the groups are nitrogen atoms, one represents CH.

[0025] Also, R 201 ~R 215 at least one of R is a phenyl group having a substituent; 201 ~R 215 and each independently represent any one of hydrogen, an alkyl group having 1 to 6 carbon atoms, an alicyclic hydrocarbon group having 3 to 10 carbon atoms, a substituted or unsubstituted ring-forming aromatic hydrocarbon group having 6 to 14 carbon atoms, or a substituted or unsubstituted pyridyl group.

[0026] The phenyl group having the substituent has one or two substituents, each of which is independently an alkyl group having 1 to 6 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 in a ring.

[0027] (5) Another embodiment of the present invention is the light-emitting device described above, wherein the first organic compound ETM contains sp3 carbon, the sp3 carbon forms a bond with another atom through an sp3 hybrid orbital, and the sp3 carbon accounts for 10% to 60% of all carbon atoms contained in the first organic compound ETM.

[0028] This allows the light emitted from the first layer to be extracted efficiently, or allows blue light to be extracted efficiently, resulting in a novel light-emitting device that is highly convenient, useful, and reliable.

[0029] (6) Another embodiment of the present invention is a light-emitting device including the above-described light-emitting device and a transistor or a substrate.

[0030] (7) Another embodiment of the present invention is a display device including the above-described light-emitting device and a transistor or a substrate.

[0031] (8) Another embodiment of the present invention is a lighting device including the above-described light-emitting device and a housing.

[0032] (9) 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.

[0033] 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 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 the 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 devices and the like may include a light-emitting device. [Effects of the Invention]

[0034] 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 electronic 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 light-emitting device, a novel light-emitting device, a novel electronic device, a novel display device, a novel lighting device, or a novel semiconductor device can be provided.

[0035] Note that the description of these effects does not preclude the existence of other effects. Note that one embodiment of the present invention does not necessarily have all of these effects. Note that effects other than these will become apparent from the description in the specification, drawings, claims, etc., and it is possible to extract other effects from the description in the specification, drawings, claims, etc. [Brief explanation of the drawings]

[0036] [Figure 1] 1A to 1C are diagrams illustrating the configuration of a light-emitting device according to an embodiment. [Figure 2] 2(A) and 2(B) are diagrams illustrating the configuration of a light-emitting device according to an embodiment. [Figure 3] FIG. 3 is a diagram illustrating the configuration of the function panel according to the embodiment. [Figure 4] 4A to 4C are diagrams illustrating the configuration of a functional panel according to an embodiment. [Figure 5] 5(A) and (B) are conceptual diagrams of an active matrix light emitting device. [Figure 6] 6(A) and 6(B) are conceptual diagrams of an active matrix light emitting device. [Figure 7] FIG. 7 is a conceptual diagram of an active matrix light emitting device. [Figure 8] 8(A) and (B) are conceptual diagrams of a passive matrix light emitting device. [Figure 9] 9(A) and (B) are diagrams showing the lighting device. [Figure 10] 10A to 10D are diagrams showing electronic devices. [Figure 11] 11A to 11C are diagrams showing electronic devices. [Figure 12] FIG. 12 is a diagram showing a lighting device. [Figure 13] FIG. 13 is a diagram showing a lighting device. [Figure 14] FIG. 14 is a diagram showing an in-vehicle display device and a lighting device. [Figure 15] 15(A) to 15(C) are diagrams showing electronic devices. [Figure 16] FIG. 16 is a diagram illustrating the configuration of a light-emitting device according to an example. [Figure 17] FIG. 17 is a diagram illustrating the emission spectrum of the luminescent material according to the example. [Figure 18]FIG. 18 is a diagram illustrating the wavelength-refractive index characteristics of the organic compound ETM according to the example. [Figure 19] FIG. 19 is a diagram illustrating the current density-luminance characteristics of the light-emitting device according to the example. [Figure 20] FIG. 20 is a diagram illustrating the luminance-current efficiency characteristics of the light-emitting device according to the example. [Figure 21] FIG. 21 is a diagram illustrating the voltage-luminance characteristics of the light-emitting device according to the example. [Figure 22] FIG. 22 is a diagram illustrating the voltage-current characteristics of the light-emitting device according to the example. [Figure 23] FIG. 23 is a diagram illustrating the luminance-blue index characteristics of the light-emitting device according to the example. [Figure 24] FIG. 24 is a diagram illustrating the emission spectrum of the light-emitting device according to the example. [Figure 25] FIG. 25 is a diagram illustrating the configuration of a light-emitting device according to an example. [Figure 26] FIG. 26 is a diagram illustrating the emission spectrum of the luminescent material according to the example. [Figure 27] FIG. 27 is a diagram illustrating the wavelength-refractive index characteristics and wavelength-reflectance characteristics of the material according to the example. DETAILED DESCRIPTION OF THE INVENTION

[0037] A light-emitting device according to one embodiment of the present invention includes a first electrode, a second electrode, a first layer, and a second layer. The second electrode has a region overlapping with the first electrode, the first layer has a region sandwiched between the first electrode and the second electrode, and the second layer has a region sandwiched between the first layer and the second electrode. The first layer includes a light-emitting material that emits photoluminescent light. The photoluminescent light has a first spectrum, with a maximum peak at a wavelength λ1 in the range of 440 nm to 470 nm. The second layer includes a first organic compound ETM that has a first refractive index n1 for light having the wavelength λ1, the first refractive index n1 being 1.4 to 1.75.

[0038] This allows the light emitted from the first layer to be extracted efficiently, or allows blue light to be extracted efficiently, resulting in a novel light-emitting device that is highly convenient, useful, and reliable.

[0039] 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.

[0040] (Embodiment 1) In this embodiment, a structure of a light-emitting device 150 of one embodiment of the present invention will be described with reference to FIG.

[0041] 1A is a cross-sectional view illustrating the structure of a light-emitting device according to one embodiment of the present invention, FIG. 1B is an emission spectrum and wavelength-refractive index characteristics illustrating the structure of a light-emitting device according to one embodiment of the present invention, and FIG. 1C is a diagram illustrating the structure of a light-emitting device according to one embodiment of the present invention.

[0042] <Configuration Example 1 of Light-Emitting Device 150> A light-emitting device 150 described in this embodiment includes an electrode 101, an electrode 102, and a unit 103 (see FIG. 1A).

[0043] The electrode 102 has an area that overlaps with the electrode 101, and the unit 103 has an area that is sandwiched between the electrode 101 and the electrode 102.

[0044] <Configuration example 1 of unit 103> The unit 103 includes a layer 111 and a layer 113. The unit 103 has a function of emitting light EL1.

[0045] 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.

[0046] <<Configuration Example 1 of Layer 111>> Layer 111 comprises the area sandwiched between electrode 101 and electrode 102 .

[0047] For example, a light-emitting material can be used for the layer 111. The layer 111 can also be called a light-emitting layer. It is preferable to arrange the layer 111 in a region where holes and electrons recombine. This allows the energy generated by the recombination of carriers to be efficiently converted into light and emitted. It is also preferable to arrange the layer 111 away from metals used for electrodes, etc. This makes it possible to suppress the quenching phenomenon caused by metals used for electrodes, etc.

[0048] [Example 1 of luminescent material] Materials that emit photoluminescent light can be used as the light-emitting material.

[0049] The photoluminescent light has a spectrum φ1, and the spectrum φ1 has a maximum peak at a wavelength λ1 (see FIG. 1(B)). The wavelength λ1 is in the range of 440 nm to 470 nm. The photoluminescence of a luminescent material can be observed, for example, when the luminescent material is dissolved in a solvent. For example, the photoluminescence of a luminescent material can be observed when the material is dissolved in a polar solvent, a non-polar solvent, or water. Specifically, toluene, dichloromethane, acetonitrile, or the like can be used as the solvent. Toluene is particularly suitable.

[0050] Examples of the light-emitting material include a material having a diazaboranaphthoanthracene skeleton such as 2,12-di(tert-butyl)-5,9-di(4-tert-butylphenyl)-N,N-diphenyl-5H,9H-[1,4]benzazaborino[2,3,4-kl]phenazaborin-7-amine (abbreviation: DPhA-tBu4DABNA), 3,10-bis[N-(dibenzofuran-3-yl)-N-phenazaborin-7-amine], and Materials having a naphthobenzofuran skeleton, such as 3,10-bis[N-(9-phenyl-9H-carbazol-2-yl)-N-phenylamino]naphtho[2,3-b;6,7-b']bisbenzofuran (abbreviation: 3,10FrA2Nbf(IV)-02), 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), and the like, can be used.

[0051] [Example 2 of luminescent material] The light-emitting material emits photoluminescent light, and the photoluminescent light has a spectrum φ1 (see FIG. 1(B)). The spectrum φ1 has a full width at half maximum FWHM of 10 nm to 35 nm.

[0052] Examples of the light-emitting material include a material having a diazaboranaphthoanthracene skeleton such as 2,12-di(tert-butyl)-5,9-di(4-tert-butylphenyl)-N,N-diphenyl-5H,9H-[1,4]benzazaborino[2,3,4-kl]phenazaborin-7-amine (abbreviation: DPhA-tBu4DABNA), 3,10-bis[N-(dibenzofuran-3-yl)-N-phenazaborin-7-amine], and Materials having a naphthobenzofuran skeleton, such as 3,10-bis[N-(9-phenyl-9H-carbazol-2-yl)-N-phenylamino]naphtho[2,3-b;6,7-b']bisbenzofuran (abbreviation: 3,10FrA2Nbf(IV)-02), 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), and the like, can be used.

[0053] <<Configuration Example 2 of Layer 111>> A material having a carrier transport property can be used as the host material. For example, a material having a hole transport property, a material having an electron transport property, 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 material having a larger band gap than the light-emitting material contained in the layer 111 is preferably used as the host material. This can suppress energy transfer from excitons generated in the layer 111 to the host material.

[0054] [Hole-transporting materials] The hole mobility is 1×10 -6 cm 2 A material having a Vs value of 1 / Vs or more can be suitably used as a material having hole transport properties.

[0055] 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.

[0056] [Electron transporting materials] For example, a metal complex or an organic compound having a π-electron-deficient heteroaromatic ring skeleton can be used as the material having electron transport properties.

[0057] 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.

[0058] [Materials with anthracene skeleton] An organic compound having an anthracene skeleton can be used as a host material. In particular, when a fluorescent material is used as the light-emitting material, an organic compound having an anthracene skeleton is suitable. This allows for the realization of a light-emitting device with good luminous efficiency and durability.

[0059] As organic compounds having an anthracene skeleton, organic compounds having a diphenylanthracene skeleton, particularly a 9,10-diphenylanthracene skeleton, are preferred due to their chemical stability. Furthermore, host materials having a carbazole skeleton are preferred because of their enhanced hole injection and transport properties. In particular, host materials containing a dibenzocarbazole skeleton are preferred because their HOMO level is approximately 0.1 eV shallower than that of carbazole, making it easier for holes to enter, and they also have excellent hole transport properties and high heat resistance. From the perspective of hole injection and transport properties, a benzofluorene skeleton or a dibenzofluorene skeleton may be used instead of the carbazole skeleton.

[0060] 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.

[0061] [Substances that exhibit thermally activated delayed fluorescence (TADF)] TADF materials can be used as host materials. When TADF materials are used as host materials, triplet excitation energy generated in the TADF material can be converted to singlet excitation energy through reverse intersystem crossing. Furthermore, the excitation energy can be transferred to the 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 light-emitting devices.

[0062] [Mixed material composition example 1] Alternatively, a mixture of multiple 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 mixture. The weight ratio of the material having a hole-transporting property to the material having an electron-transporting property contained in the mixture may be 1:19 to 19:1 (material having a hole-transporting property:material having an electron-transporting property). This allows easy adjustment of the carrier transport property of the layer 111. Furthermore, the recombination region can be easily controlled.

[0063] <<Configuration Example 1 of Layer 113>> Layer 113 comprises the area sandwiched between layer 111 and electrode 102 .

[0064] 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. The layer 113 can be referred to as an electron-transporting layer. Note that a material having a larger band gap than that of the light-emitting material contained in the layer 111 is preferably used for the layer 113. This can suppress energy transfer from excitons generated in the layer 111 to the layer 113.

[0065] [Electron transporting materials] For example, a metal complex or an organic compound having a π-electron-deficient heteroaromatic ring skeleton can be used as the material having electron transport properties.

[0066] When the square root of the electric field strength [V / cm] is 600, the electron mobility is 1×10 -7 cm 2 / Vs or more, 5×10 -5 cm 2 A material having a VI of 1 / Vs or less can be suitably used as a material having electron transport properties. This can suppress the electron transport properties in the electron transport layer, or can control the amount of electrons injected into the light-emitting layer. Alternatively, it can prevent the light-emitting layer from becoming electron-excessive.

[0067] 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.

[0068] [Materials with anthracene skeleton] An organic compound having an anthracene skeleton can be used for the layer 113. In particular, an organic compound having both an anthracene skeleton and a heterocyclic skeleton can be suitably used.

[0069] For example, an organic compound containing both an anthracene skeleton and a nitrogen-containing five-membered ring skeleton can be used. Alternatively, an organic compound containing both an anthracene skeleton and a nitrogen-containing five-membered ring skeleton containing two heteroatoms in the ring can be used. Specifically, a pyrazole ring, an imidazole ring, an oxazole ring, a thiazole ring, etc. can be suitably used as the heterocyclic skeleton.

[0070] For example, an organic compound containing both an anthracene skeleton and a nitrogen-containing six-membered ring skeleton can be used. Alternatively, an organic compound containing both an anthracene skeleton and a nitrogen-containing six-membered ring skeleton containing two heteroatoms in the ring can be used. Specifically, a pyrazine ring, a pyrimidine ring, a pyridazine ring, or the like can be suitably used as the heterocyclic skeleton.

[0071] [Example of mixed material composition] Alternatively, a mixture of a plurality of substances can be used for the layer 113. Specifically, a mixture of an alkali metal, an alkali metal compound, or an alkali metal complex, and a substance having an electron-transport property can be used for the layer 113. Note that the HOMO level of the material having an electron-transport property is more preferably −6.0 eV or higher.

[0072] Furthermore, in combination with a structure in which a composite material is used for the layer 104, the mixed material can be suitably used for the layer 113. For example, a composite material of a substance having an acceptor property and a material having a hole-transporting property can be used for the layer 104. Specifically, a composite material of a substance having an acceptor property and a substance having a relatively deep HOMO level HOMO1 of −5.7 eV or more and −5.4 eV or less can be used for the layer 104 (see FIG. 1C). By using the mixed material for the layer 113 in combination with a structure in which such a composite material is used for the layer 104, the reliability of the light-emitting device can be improved.

[0073] It is preferable to combine a structure in which the mixed material is used for the layer 113 and the composite material is used for the layer 104 with a structure in which a material having a hole-transporting property is used for the layer 112. For example, a substance having a HOMO level HOMO2 in the range of −0.2 eV to 0 eV with respect to the above-mentioned relatively deep HOMO level HOMO1 can be used for the layer 112 (see FIG. 1C). This can improve the reliability of the light-emitting device.

[0074] The alkali metal, alkali metal compound, or alkali metal complex is preferably present with a concentration difference (including zero) in the thickness direction of the layer 113.

[0075] For example, a metal complex containing an 8-hydroxyquinolinato structure can be used. Also, a methyl-substituted metal complex containing an 8-hydroxyquinolinato structure (for example, a 2-methyl-substituted or 5-methyl-substituted metal complex) can be used.

[0076] Examples of metal complexes containing an 8-hydroxyquinolinato structure that can be used include 8-hydroxyquinolinato-lithium (abbreviated as Liq), 8-hydroxyquinolinato-sodium (abbreviated as Naq), etc. In particular, complexes of monovalent metal ions, especially lithium complexes, are preferred, with Liq being more preferred.

[0077] <<Configuration Example 2 of Layer 113>> The layer 113 includes an organic compound ETM. The organic compound ETM has a refractive index n1 with respect to light having a wavelength λ1, and the refractive index n1 is 1.4 or more and 1.75 or less (see FIG. 1B).

[0078] This allows efficient extraction of light emitted from layer 111. Alternatively, it allows efficient extraction of blue light. As a result, it is possible to provide a novel light-emitting device that is highly convenient, useful, and reliable.

[0079] This also makes it possible to increase the reflectivity of the electrode 102 when a reflective metal such as silver is used for the electrode 102. As a result, a novel light-emitting device that is highly convenient, useful, and reliable can be provided.

[0080] Furthermore, when the reflectivity of the electrode 102 is high, if a light-emitting material having the function of emitting light with an emission spectrum having a narrow full width at half maximum (FWHM) is used for the layer 111, the light emitted from the layer 111 can be extracted efficiently.

[0081] Therefore, a light-emitting device with high luminous efficiency can be provided by providing layer 111 with a light-emitting material capable of emitting light having an emission spectrum with a narrow full width at half maximum (FWHM), and by providing layer 113 with an organic compound with a low refractive index. Furthermore, since organic compounds generally have a higher refractive index for light in the blue wavelength range than for red, using an organic compound with a low refractive index for light in the blue wavelength range for layer 113 is particularly useful because it allows blue light to be extracted efficiently.

[0082] [Example 1 of organic compound ETM] The organic compound ETM may be a material having an ordinary refractive index of 1.50 or more and 1.75 or less in the blue light emission region (455 nm or more and 465 nm or less), or an ordinary refractive index of 1.45 or more and 1.70 or less in the 633 nm light wavelength range typically used for measuring refractive index.

[0083] If the material has anisotropy, the refractive index for ordinary light and the refractive index for extraordinary light may differ. If the thin film to be measured is in such a state, anisotropy analysis can be performed to separate the ordinary refractive index and the extraordinary refractive index and calculate each refractive index. In this specification, if the measured material has both an ordinary refractive index and an extraordinary refractive index, the ordinary refractive index is used as the index.

[0084] One example of the ETM organic compound is an organic compound having at least one six-membered heteroaromatic ring containing one to three nitrogen atoms, a plurality of aromatic hydrocarbon rings each having 6 to 14 carbon atoms forming the ring, at least two of the aromatic hydrocarbon rings being benzene rings, and a plurality of hydrocarbon groups bonding via sp3 hybrid orbitals.

[0085] In addition, in such an organic compound, the ratio of the number of carbon atoms forming bonds with sp3 hybrid orbitals to the total number of carbon atoms in the molecule of the organic compound is preferably 10% or more and 60% or less, more preferably 10% or more and 50% or less. 1 In the results of measuring the organic compound by H-NMR, the integral value of signals below 4 ppm is preferably at least half the integral value of signals at 4 ppm or higher.

[0086] It is preferable that all of the hydrocarbon groups forming bonds through sp3 hybrid orbitals possessed by the organic compound are bonded to the aromatic hydrocarbon ring having 6 to 14 carbon atoms forming the ring, and that the LUMO of the organic compound is not distributed in the aromatic hydrocarbon ring.

[0087] [Example 2 of organic compound ETM] For example, the following general formula (G e1 The organic compound represented by formula 1) can be used as the organic compound ETM.

[0088] [ka]

[0089] In the formula, A represents a 6-membered heteroaromatic ring containing 1 to 3 nitrogen atoms, and is preferably a pyridine ring, a pyrimidine ring, a pyrazine ring, a pyridazine ring, or a triazine ring.

[0090] Also, R 200 is hydrogen, an alkyl group having 1 to 6 carbon atoms, an alicyclic group having 3 to 10 carbon atoms, or a group represented by the formula (G e1 1-1).

[0091] R 201 ~R 215 At least one of R is a phenyl group having a substituent, and the others each independently represent any one of hydrogen, an alkyl group having 1 to 6 carbon atoms, an alicyclic group having 3 to 10 carbon atoms, a substituted or unsubstituted ring-forming aromatic hydrocarbon group having 6 to 14 carbon atoms, and a substituted or unsubstituted pyridyl group. 201 , R 203 , R 205 , R 206 , R 208 , R 210 , R 211 , R 213 and R 215 is preferably hydrogen. The phenyl group having the substituent has one or two substituents, each of which is independently any one of an alkyl group having 1 to 6 carbon atoms, an alicyclic group having 3 to 10 carbon atoms, and a substituted or unsubstituted aromatic hydrocarbon group having 6 to 14 carbon atoms in a ring.

[0092] In addition, the above general formula (G e1 The organic compound represented by 1) has a plurality of hydrocarbon groups selected from alkyl groups having 1 to 6 carbon atoms and alicyclic groups having 3 to 10 carbon atoms, and the ratio of the total number of carbon atoms forming bonds with sp3 hybrid orbitals to the total number of carbon atoms in the molecule is 10% or more and 60% or less.

[0093] [Example 3 of organic compound ETM] For example, the following general formula (G e1 The organic compound represented by 2) can be used as the organic compound ETM.

[0094] [ka]

[0095] In the above general formula, Q 1 ~Q 3 2 or 3 of the atoms are nitrogen atoms, and Q 1 ~Q 3 When two of the groups are nitrogen atoms, one represents CH.

[0096] R 201 ~R 215 at least one of R is a phenyl group having a substituent; 201 ~R 215 and each independently represent any one of hydrogen, an alkyl group having 1 to 6 carbon atoms, an alicyclic hydrocarbon group having 3 to 10 carbon atoms, a substituted or unsubstituted ring-forming aromatic hydrocarbon group having 6 to 14 carbon atoms, or a substituted or unsubstituted pyridyl group.

[0097] The phenyl group having a substituent has one or two substituents, each of which is independently an alkyl group having 1 to 6 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 in a ring.

[0098] [Example 4 of organic compound ETM] Furthermore, for example, the general formula (G e1 Among the organic compounds represented by formula 2), those in which sp3 carbons account for 10% to 60% of the total carbon atoms contained in the organic compound can be used as organic compounds for ETM. Note that sp3 carbons are carbons that form bonds with other atoms via sp3 hybrid orbitals.

[0099] In addition, the above general formula (G e1 1) or (G e1 In the organic compound represented by formula (G e1 1-2) is preferred.

[0100] [ka]

[0101] In the formula, α represents a substituted or unsubstituted phenylene group, and is preferably a meta-substituted phenylene group. Furthermore, when the meta-substituted phenylene group has one substituent, the substituent is preferably also substituted at the meta-position. The substituent is preferably an alkyl group having 1 to 6 carbon atoms or an alicyclic group having 3 to 10 carbon atoms, more preferably an alkyl group having 1 to 6 carbon atoms, and even more preferably a t-butyl group.

[0102] R 220 represents an alkyl group having 1 to 6 carbon atoms, an alicyclic group having 3 to 10 carbon atoms, or a substituted or unsubstituted aromatic hydrocarbon group having 6 to 14 carbon atoms in a ring.

[0103] Furthermore, j and k represent 1 or 2. When j is 2, the multiple α may be the same or different. When k is 2, the multiple R 220 may be the same or different. 220 is preferably a phenyl group, more preferably a phenyl group having an alkyl group having 1 to 6 carbon atoms or an alicyclic group having 3 to 10 carbon atoms at one or both of the two meta positions. The substituent that the phenyl group has at one or both of the two meta positions is more preferably an alkyl group having 1 to 6 carbon atoms, and even more preferably a t-butyl group.

[0104] This allows efficient extraction of light emitted from layer 111. Alternatively, it allows efficient extraction of blue light. As a result, it is possible to provide a novel light-emitting device that is highly convenient, useful, and reliable.

[0105] <Configuration example of electrode 102> A conductive material can be used for the electrode 102. Specifically, a metal, an alloy, a conductive compound, or a mixture thereof can be used for the electrode 102. For example, a material having a smaller work function than the electrode 101 can be suitably used for the electrode 102. Specifically, a material having a work function of 3.8 eV or less is preferred.

[0106] For example, silver (Ag) or an alloy containing silver (such as MgAg) can be used for the electrode 102 .

[0107] This allows light emitted from layer 111 to be extracted efficiently. Alternatively, blue light can be extracted efficiently. Alternatively, highly saturated light can be extracted efficiently. Alternatively, a microresonator structure can be formed using layer 113 and electrode 102. Alternatively, the width of the spectrum of the emitted light can be narrowed using the microresonator structure. Alternatively, light can be utilized with high efficiency even when the microresonator structure is used. As a result, a novel light-emitting device with excellent convenience, usefulness, and reliability can be provided.

[0108] <Configuration example 2 of unit 103> The unit 103 includes a layer 112. The layer 112 includes a region sandwiched between the electrode 101 and the layer 111 (see FIG. 1(A)).

[0109] Example of Layer 112 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 a material having a larger band gap than that of the light-emitting material contained in the layer 111 is preferably used for the layer 112. This can suppress energy transfer from excitons generated in the layer 111 to the layer 112.

[0110] [Hole-transporting materials] The hole mobility is 1×10 -6 cm 2 A material having a Vs value of 1 / Vs or more can be suitably used as a material having hole transport properties.

[0111] 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.

[0112] 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: PCBBi1BP), 4-(1-naphthyl)-4'-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBANB), 4,4'-di(1-naphthyl)-4''-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBNBB), 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.

[0113] 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).

[0114] 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).

[0115] 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.

[0116] Note that this embodiment mode can be appropriately combined with other embodiment modes described in this specification.

[0117] (Embodiment 2) In this embodiment, a structure of a light-emitting device 150 of one embodiment of the present invention will be described with reference to FIG.

[0118] <Configuration Example of Light-Emitting Device 150> A light-emitting device 150 described in this embodiment includes an electrode 101, an electrode 102, a unit 103, and a layer 104. The electrode 102 has a region overlapping with the electrode 101, and the unit 103 has a region sandwiched between the electrode 101 and the electrode 102. The layer 104 has a region sandwiched between the electrode 101 and the unit 103. For example, the structure described in Embodiment 1 can be used for the unit 103.

[0119] <Configuration example of electrode 101> For example, a conductive material can be used for the electrode 101. Specifically, a metal, an alloy, a conductive compound, a mixture thereof, or the like can be used for the electrode 101. For example, a material having a work function of 4.0 eV or more can be suitably used.

[0120] For example, indium oxide-tin oxide (ITO), indium oxide-tin oxide containing silicon or silicon oxide, indium oxide-zinc oxide, indium oxide containing tungsten oxide and zinc oxide (IWZO), etc. can be used.

[0121] Also, for example, gold (Au), platinum (Pt), nickel (Ni), tungsten (W), chromium (Cr), molybdenum (Mo), iron (Fe), cobalt (Co), copper (Cu), palladium (Pd), or nitrides of metal materials (e.g., titanium nitride), etc., can be used. Alternatively, graphene can be used.

[0122] Example of Layer 104 For example, a material having a hole-injecting property can be used for the layer 104. The layer 104 can also be called a hole-injecting layer.

[0123] Specifically, a substance having an acceptor property can be used for the layer 104. Alternatively, a composite material of a substance having an acceptor property and a material having a hole-transporting property can be used for the layer 104. This can make it easier to inject holes from the electrode 101, for example. Alternatively, the driving voltage of the light-emitting device can be reduced.

[0124] [Acceptor substances] An organic compound or an inorganic compound can be used as the acceptor material. The acceptor material can extract electrons from the adjacent hole transport layer or the material having hole transport properties when an electric field is applied.

[0125] For example, a compound having an electron-withdrawing group (a halogen group or a cyano group) can be used as a substance having acceptor properties. Note that organic compounds having acceptor properties are easy to evaporate and form into films. This can increase the productivity of light-emitting devices.

[0126] Specifically, 7,7,8,8-tetracyano-2,3,5,6-tetrafluoroquinodimethane (abbreviation: F4-TCNQ), chloranil, 2,3,6,7,10,11-hexacyano-1,4,5,8,9,12-hexaazatriphenylene (abbreviation: HAT-CN), 1,3,4,5,7,8-hexafluorotetracyano-naphthoquinodimethane (abbreviation: F6-TCNNQ), 2-(7-dicyanomethylene-1,3,4,5,6,8,9,10-octafluoro-7H-pyren-2-ylidene)malononitrile, and the like can be used.

[0127] In particular, compounds such as HAT-CN in which an electron-withdrawing group is bonded to a condensed aromatic ring having a plurality of heteroatoms are preferred because they are thermally stable.

[0128] Radialene derivatives having an electron-withdrawing group (particularly a halogen group such as a fluoro group or a cyano group) are also preferred because of their extremely high electron-accepting properties.

[0129] Specifically, α,α',α''-1,2,3-cyclopropanetriylidene tris[4-cyano-2,3,5,6-tetrafluorobenzeneacetonitrile], α,α',α''-1,2,3-cyclopropanetriylidene tris[2,6-dichloro-3,5-difluoro-4-(trifluoromethyl)benzeneacetonitrile], α,α',α''-1,2,3-cyclopropanetriylidene tris[2,3,4,5,6-pentafluorobenzeneacetonitrile], and the like can be used.

[0130] Furthermore, molybdenum oxide, vanadium oxide, ruthenium oxide, tungsten oxide, manganese oxide, or the like can be used as the substance having acceptor properties.

[0131] In addition, phthalocyanine complex compounds such as phthalocyanine (abbreviation: HPc) and copper phthalocyanine (CuPc), and compounds having an aromatic amine skeleton such as 4,4'-bis[N-(4-diphenylaminophenyl)-N-phenylamino]biphenyl (abbreviation: DPAB) and N,N'-bis{4-[bis(3-methylphenyl)amino]phenyl}-N,N'-diphenyl-(1,1'-biphenyl)-4,4'-diamine (abbreviation: DNTPD) can be used.

[0132] Furthermore, polymers such as poly(3,4-ethylenedioxythiophene) / poly(styrenesulfonic acid) (PEDOT / PSS) can also be used.

[0133] [Composite material composition example 1] Furthermore, a composite material of multiple substances can be used as a material with hole injection properties. For example, a composite material can be made of a substance with acceptor properties and a material with hole transport properties. This allows not only a material with a high work function but also a material with a low work function to be used for the electrode 101. Alternatively, materials for the electrode 101 can be selected from a wide range of materials regardless of the work function.

[0134] For example, compounds having an aromatic amine skeleton, carbazole derivatives, aromatic hydrocarbons, aromatic hydrocarbons having a vinyl group, and polymeric compounds (oligomers, dendrimers, polymers, etc.) can be used as materials having hole transport properties for the composite material. -6 cm 2 A material having a hole transport property of 1 / Vs or more can be suitably used as the material having a hole transport property of the composite material.

[0135] Furthermore, a substance having a relatively deep HOMO level can be preferably used as the hole-transporting material of the composite material. Specifically, the HOMO level is preferably from −5.7 eV to −5.4 eV. This can facilitate injection of holes into the unit 103, or into the layer 112, or can improve the reliability of the light-emitting device.

[0136] Examples of compounds having an aromatic amine skeleton that can be used include N,N'-di(p-tolyl)-N,N'-diphenyl-p-phenylenediamine (abbreviation: DTDPPA), 4,4'-bis[N-(4-diphenylaminophenyl)-N-phenylamino]biphenyl (abbreviation: DPAB), N,N'-bis{4-[bis(3-methylphenyl)amino]phenyl}-N,N'-diphenyl-(1,1'-biphenyl)-4,4'-diamine (abbreviation: DNTPD), and 1,3,5-tris[N-(4-diphenylaminophenyl)-N-phenylamino]benzene (abbreviation: DPA3B).

[0137] Examples of carbazole derivatives include 3-[N-(9-phenylcarbazol-3-yl)-N-phenylamino]-9-phenylcarbazole (abbreviation: PCzPCA1), 3,6-bis[N-(9-phenylcarbazol-3-yl)-N-phenylamino]-9-phenylcarbazole (abbreviation: PCzPCA2), 3-[N-(1-naphthyl)-N-(9-phenylcarbazol-3-yl)amino]-9-phenylcarbazole, Examples of suitable carbazoles that can be used include 4,4'-di(N-carbazolyl)biphenyl (abbreviation: CBP), 1,3,5-tris[4-(N-carbazolyl)phenyl]benzene (abbreviation: TCPB), 9-[4-(10-phenyl-9-anthracenyl)phenyl]-9H-carbazole (abbreviation: CzPA), and 1,4-bis[4-(N-carbazolyl)phenyl]-2,3,5,6-tetraphenylbenzene.

[0138] Examples of aromatic hydrocarbons include 2-tert-butyl-9,10-di(2-naphthyl)anthracene (abbreviation: t-BuDNA), 2-tert-butyl-9,10-di(1-naphthyl)anthracene, 9,10-bis(3,5-diphenylphenyl)anthracene (abbreviation: DPPA), 2-tert-butyl-9,10-bis(4-phenylphenyl)anthracene (abbreviation: t-BuDBA), 9,10-di(2-naphthyl)anthracene (abbreviation: DNA), 9,10-diphenylanthracene (abbreviation: DPAnth), 2-tert-butylanthracene (abbreviation: t-BuAnth), 9,10-bis(4-methyl-1-naphthyl)anthracene (abbreviation: DMNA), 2-tert-butyl-9,10 -bis[2-(1-naphthyl)phenyl]anthracene, 9,10-bis[2-(1-naphthyl)phenyl]anthracene, 2,3,6,7-tetramethyl-9,10-di(1-naphthyl)anthracene, 2,3,6,7-tetramethyl-9,10-di(2-naphthyl)anthracene, 9,9'-bianthryl, 10,10'-diphenyl-9,9'-bianthryl, 10,10'-bis(2-phenylphenyl)-9,9'-bianthryl, 10,10'-bis[(2,3,4,5,6-pentaphenyl)phenyl]-9,9'-bianthryl, anthracene, tetracene, rubrene, perylene, 2,5,8,11-tetra(tert-butyl)perylene, pentacene, coronene, and the like can be used.

[0139] Examples of aromatic hydrocarbons having a vinyl group that can be used include 4,4'-bis(2,2-diphenylvinyl)biphenyl (abbreviation: DPVBi) and 9,10-bis[4-(2,2-diphenylvinyl)phenyl]anthracene (abbreviation: DPVPA).

[0140] Examples of polymer compounds that can be used include poly(N-vinylcarbazole) (abbreviation: PVK), poly(4-vinyltriphenylamine) (abbreviation: PVTPA), poly[N-(4-{N'-[4-(4-diphenylamino)phenyl]phenyl-N'-phenylamino}phenyl)methacrylamide] (abbreviation: PTPDMA), and poly[N,N'-bis(4-butylphenyl)-N,N'-bis(phenyl)benzidine] (abbreviation: Poly-TPD).

[0141] For example, a substance having any of a carbazole skeleton, a dibenzofuran skeleton, a dibenzothiophene skeleton, and an anthracene skeleton can be suitably used as a material having hole transport properties for the composite material. Furthermore, a substance having an aromatic amine with a substituent containing a dibenzofuran ring or a dibenzothiophene ring, an aromatic monoamine with a naphthalene ring, or an aromatic monoamine in which a 9-fluorenyl group is bonded to the nitrogen of the amine via an arylene group can be used as a material having hole transport properties for the composite material. The use of a substance having an N,N-bis(4-biphenyl)amino group can improve the reliability of light-emitting devices.

[0142] These materials include, for example, 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-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: BBAαNβNB-0) 3), 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' '-Phenyltriphenylamine (abbreviation: TPBiAβNBi), 4-phenyl-4'-(1-naphthyl)triphenylamine (abbreviation: αNBA1BP), 4,4'-bis(1-naphthyl)triphenylamine (abbreviation: αNBB1BP), 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-(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''-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBBi1BP), 4-(1-naphthyl)-4'-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBANB), 4,4'- Di(1-naphthyl)-4''-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBNBB), N-phenyl-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]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), N,N-bis(9 ,9-dimethyl-9H-fluoren-2-yl)-9,9'-spirobi-9H-fluoren-4-amine, N,N-bis(9,9-dimethyl-9H-fluoren-2-yl)-9,9'-spirobi-9H-fluoren-3-amine, N,N-bis(9,9-dimethyl-9H-fluoren-2-yl)-9,9'-spirobi-9H-fluoren-2-amine, N,N-bis(9,9-dimethyl-9H-fluoren-2-yl)-9,9'-spirobi-9H-fluoren-1-amine, etc. can be used.

[0143] [Composite material composition example 2] For example, a composite material containing a substance having acceptor properties, a material having hole-transport properties, and an alkali metal fluoride or an alkaline earth metal fluoride can be used as the material having hole-injection properties. In particular, a composite material containing fluorine atoms at an atomic ratio of 20% or more can be preferably used. This can reduce the refractive index of the layer 104. Alternatively, a layer with a low refractive index can be formed inside the light-emitting device. Alternatively, the external quantum efficiency of the light-emitting device can be improved.

[0144] Note that this embodiment mode can be appropriately combined with other embodiment modes described in this specification.

[0145] (Embodiment 3) In this embodiment, a structure of a light-emitting device 150 of one embodiment of the present invention will be described with reference to FIG.

[0146] <Configuration Example of Light-Emitting Device 150> A light-emitting device 150 described in this embodiment includes an electrode 101, an electrode 102, a unit 103, and a layer 105. The electrode 102 has a region overlapping with the electrode 101, and the unit 103 has a region sandwiched between the electrode 101 and the electrode 102. The layer 105 has a region sandwiched between the unit 103 and the electrode 102. Note that, for example, the structure described in Embodiment 1 or 2 can be used for the unit 103.

[0147] <Configuration example of electrode 102> For example, a conductive material can be used for the electrode 102. Specifically, a metal, an alloy, a conductive compound, or a mixture thereof can be used for the electrode 102. For example, a material having a smaller work function than the electrode 101 can be suitably used for the electrode 102. Specifically, a material having a work function of 3.8 eV or less is preferred.

[0148] For example, the electrode 102 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.

[0149] 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 102.

[0150] 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.

[0151] 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, for example, from the electrode 102. 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 102. Alternatively, a material for the electrode 102 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 102. Alternatively, the driving voltage of the light-emitting device can be reduced.

[0152] [Substances with donor properties] For example, alkali metals, alkaline earth metals, rare earth metals, or compounds thereof (oxides, halides, carbonates, etc.) can be used as the donor substance. Alternatively, organic compounds such as tetrathianaphthacene (abbreviated as TTN), nickelocene, and decamethylnickelocene can also be used as the donor substance.

[0153] 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).

[0154] As the alkaline earth metal compound (including oxides, halides, and carbonates), calcium fluoride (CaF2) and the like can be used.

[0155] [Composite material composition example 1] Furthermore, a composite material of a plurality of substances can be used as a material having an electron injection property. For example, a composite material can be used that includes a substance having a donor property and a material having an electron transport property.

[0156] [Electron transporting materials] For example, a metal complex or an organic compound having a π-electron-deficient heteroaromatic ring skeleton can be used as the material having electron transport properties.

[0157] When the square root of the electric field strength [V / cm] is 600, the electron mobility is 1×10 -7 cm 2 / Vs or more, 5×10 -5 cm 2 A material having a VI of 1 / Vs or less can be suitably used as a material having electron transport properties. This can suppress the electron transport properties in the electron transport layer, or can control the amount of electrons injected into the light-emitting layer. Alternatively, it can prevent the light-emitting layer from becoming electron-excessive.

[0158] Examples of metal complexes that can be used include bis(10-hydroxybenzo[h]quinolinato)beryllium(II) (abbreviation: BeBq2), bis(2-methyl-8-quinolinolato)(4-phenylphenolato)aluminum(III) (abbreviation: BAlq), bis(8-quinolinolato)zinc(II) (abbreviation: Znq), bis[2-(2-benzoxazolyl)phenolato]zinc(II) (abbreviation: ZnPBO), and bis[2-(2-benzothiazolyl)phenolato]zinc(II) (abbreviation: ZnBTZ).

[0159] 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.

[0160] 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), etc. can be used.

[0161] 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: 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.

[0162] 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.

[0163] 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.

[0164] [Composite material composition example 2] Furthermore, a microcrystalline alkali metal fluoride and a material having electron transport properties can be used for the composite material. Alternatively, a microcrystalline alkaline earth metal fluoride and a material having electron transport properties 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 104. Alternatively, the external quantum efficiency of the light-emitting device can be improved.

[0165] [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.

[0166] Note that this embodiment mode can be appropriately combined with other embodiment modes described in this specification.

[0167] (Fourth embodiment) In this embodiment, a structure of a light-emitting device 150 of one embodiment of the present invention will be described with reference to FIG.

[0168] FIG. 2A is a cross-sectional view illustrating a structure of a light-emitting device of one embodiment of the present invention.

[0169] <Configuration Example of Light-Emitting Device 150> Furthermore, the light-emitting device 150 described in this embodiment includes an electrode 101, an electrode 102, a unit 103, and an intermediate layer 106 (see FIG. 2(A)). The electrode 102 has a region overlapping with the electrode 101, and the unit 103 has a region sandwiched between the electrode 101 and the electrode 102. The intermediate layer 106 has a region sandwiched between the unit 103 and the electrode 102.

[0170] <<Configuration example of the middle layer 106>> The intermediate layer 106 includes a layer 106 A and a layer 106 B. The layer 106 B includes a region sandwiched between the layer 106 A and the electrode 102 .

[0171] <<Configuration example of layer 106A>> For example, a material having electron transport properties can be used for the layer 106A. The layer 106A can also be referred to as an electron relay layer. By using the layer 106A, the layer in contact with the anode side of the layer 106A can be separated from the layer in contact with the cathode side of the layer 106A. This can reduce the interaction between the layer in contact with the anode side of the layer 106A and the layer in contact with the cathode side of the layer 106A. This allows electrons to be smoothly supplied to the layer in contact with the anode side of the layer 106A.

[0172] A substance having a LUMO level between the LUMO level of a substance having acceptor properties included in a layer in contact with the anode side of the layer 106A and the LUMO level of a substance included in a layer in contact with the cathode side of the layer 106A can be suitably used for the layer 106A.

[0173] 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 layer 106A.

[0174] Specifically, a phthalocyanine-based material can be used for layer 106A, or a metal complex having a metal-oxygen bond and an aromatic ligand can be used for layer 106A.

[0175] <<Configuration example of layer 106B>> 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 layer 106B. Specifically, it can supply electrons to units 103 arranged on the anode side. Layer 106B can also be called a charge generation layer.

[0176] Specifically, a material having a hole-injecting property that can be used for the layer 104 can be used for the layer 106B. For example, a composite material can be used for the layer 106B. Alternatively, for example, a stacked film in which a film including the composite material and a film including a material having a hole-transporting property are stacked can be used for the layer 106B.

[0177] Note that this embodiment mode can be appropriately combined with other embodiment modes described in this specification.

[0178] (Embodiment 5) In this embodiment, a structure of a light-emitting device 150 of one embodiment of the present invention will be described with reference to FIG.

[0179] 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.

[0180] <Configuration Example of Light-Emitting Device 150> The light-emitting device 150 described in this embodiment has an electrode 101, an electrode 102, a unit 103, an intermediate layer 106, and a unit 103(12) (see FIG. 2(B)). The electrode 102 has a region overlapping with the electrode 101, the unit 103 has a region sandwiched between the electrodes 101 and 102, and the intermediate layer 106 has a region sandwiched between the unit 103 and the electrode 102. Furthermore, the unit 103(12) has a region sandwiched between the intermediate layer 106 and the electrode 102, and the unit 103(12) has a function of emitting light EL1(2).

[0181] A configuration including the intermediate layer 106 and multiple units is sometimes called 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 to a device with the same luminance. It also allows for reduced power consumption.

[0182] 《Example of Unit 103(12)》 The configuration that can be used for unit 103 can also be used for unit 103(12). In other words, light-emitting device 150 has a plurality of stacked units. Note that the number of stacked units is not limited to two, and three or more units can be stacked.

[0183] The same configuration as unit 103 can be used for unit 103(12), or a different configuration from unit 103 can be used for unit 103(12).

[0184] For example, a configuration having an emission color different from that of unit 103 can be used for unit 103(12). Specifically, a unit 103 that emits red light and green light and a unit 103(12) 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.

[0185] <<Configuration example of the middle layer 106>> The intermediate layer 106 has a function of supplying electrons to one of the unit 103 and the unit 103(12) and holes to the other. For example, the intermediate layer 106 described in Embodiment 4 can be used.

[0186] <Method for producing light-emitting device 150> For example, each layer of the electrode 101, the electrode 102, the unit 103, the intermediate layer 106, and the unit 103(12) can be formed using a dry method, a wet method, a vapor deposition method, a droplet discharge method, a coating method, a printing method, etc. Also, different methods can be used to form each component.

[0187] Specifically, the light-emitting device 150 can be produced using a vacuum deposition device, an inkjet device, a coating device such as a spin coater, a gravure printing device, an offset printing device, a screen printing device, or the like.

[0188] For example, electrodes can be formed by a wet method using a paste of a metal material or a sol-gel method. Furthermore, an indium oxide-zinc oxide film can be formed by a sputtering method using a target containing indium oxide and 1 to 20 wt% zinc oxide. Furthermore, an indium oxide (IWZO) film containing tungsten oxide and zinc oxide can be formed by a sputtering method using a target containing indium oxide and 0.5 to 5 wt% tungsten oxide and 0.1 to 1 wt% zinc oxide.

[0189] Note that this embodiment mode can be appropriately combined with other embodiment modes described in this specification.

[0190] (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 FIG.

[0191] <Configuration example of function panel 700> The functional panel 700 described in this embodiment has a light emitting device 150 and a light emitting device 150(2) (see FIG. 3).

[0192] For example, the light-emitting devices described in the first to fifth embodiments can be used as the light-emitting device 150 .

[0193] <Configuration Example of Light-Emitting Device 150(2)> The light-emitting device 150(2) described in this embodiment includes an electrode 101(2), an electrode 102, and a unit 103(2) (see FIG. 3). The electrode 102 has an area overlapping with the electrode 101(2). Note that part of the configuration of the light-emitting device 150 can be used as part of the configuration of the light-emitting device 150(2). This allows part of the configuration to be shared, or the manufacturing process can be simplified.

[0194] 《Configuration example 1 of Unit 103(2)》 Unit 103(2) comprises the region sandwiched between electrode 101(2) and electrode 102, and unit 103(2) comprises layer 111(2).

[0195] The unit 103(2) has a single layer structure or a laminated layer structure. For example, a layer selected from functional layers such as a hole transport layer, an electron transport layer, a carrier blocking layer, and an exciton blocking layer can be used for the unit 103(2).

[0196] Unit 103(2) includes a region where electrons injected from one electrode recombine with holes injected from the other electrode, for example, a region where holes injected from electrode 101(2) recombine with electrons injected from electrode 102.

[0197] <<Configuration Example 1 of Layer 111(2)>> The layer 111(2) contains a light-emitting material and a host material. The layer 111(2) can also be referred to as a light-emitting layer. It is preferable to arrange the layer 111(2) in a region where holes and electrons recombine. This allows the energy generated by carrier recombination to be efficiently converted into light and emitted. It is also preferable to arrange the layer 111(2) away from metals used in electrodes, etc. This can suppress the quenching phenomenon caused by metals used in electrodes, etc.

[0198] For example, a light-emitting material different from the light-emitting material used in layer 111 can be used in layer 111(2). Specifically, light-emitting materials with different emission colors can be used in layer 111(2). 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 with hues that cannot be displayed by individual light-emitting devices can be displayed.

[0199] 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.

[0200] For example, fluorescent materials, phosphorescent materials, or materials exhibiting thermally activated delayed fluorescence (TADF) (also known as TADF materials) can be used as the light-emitting material, allowing the energy generated by carrier recombination to be emitted from the light-emitting material as light EL1 (see Figure 1).

[0201] [Fluorescent substances] A fluorescent material can be used for the layer 111(2). For example, the fluorescent material listed below can be used for the layer 111(2). However, the present invention is not limited to this.

[0202] 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-9H-fluoren- 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: 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-[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-1,4-phenylenediamine (abbreviation: 2DPAPA), N-[9,10-bis(1,1'-biphenyl-2-yl)-2-anthryl]-N,N',N'-triphenyl-1,4-phenylenediamine (abbreviation: 2DPAB PhA), 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), 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(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 amine (abbreviation: p-mPhAFD), 2-{2-isopropyl-6-[2-(1,1,7,7-tetramethyl-2,3,6,7-tetrahydro-1H,5H-benzo[ij]quinolizin-9-yl)ethenyl]-4H-pyran-4-ylidene}propanedinitrile (abbreviation: DCJTI), 2-{2-tert-butyl-6-[2-(1,1,7,7-tetramethyl-2,3,6,7-tetrahydro-1H,5H-benzo[ij]quinolizin-9-yl)ethenyl]-4H-pyran-4-ylidene}propanedinitrile (abbreviation: DCJTB),6-Bis{2-[4-(dimethylamino)phenyl]ethenyl}-4H-pyran-4-ylidene)propanedinitrile (abbreviation: BisDCM), 2-{2,6-bis[2-(8-methoxy-1,1,7,7-tetramethyl-2,3,6,7-tetrahydro-1H,5H-benzo[ij]quinolizin-9-yl)ethenyl]-4H-pyran-4-ylidene}propanedinitrile (abbreviation: BisDCJTM), N,N'-(pyren-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.

[0203] 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.

[0204] [Phosphorescent materials] A phosphorescent material can be used for the layer 111(2). For example, the phosphorescent material listed below can be used for the layer 111(2). However, the present invention is not limited to this.

[0205] For example, organometallic iridium complexes having a 4H-triazole skeleton, organometallic iridium complexes having a 1H-triazole skeleton, organometallic iridium complexes having an imidazole skeleton, organometallic iridium complexes having a phenylpyridine derivative having an electron-withdrawing group as a ligand, organometallic iridium complexes having a pyrimidine skeleton, organometallic iridium complexes having a pyrazine skeleton, organometallic iridium complexes having a pyridine skeleton, rare earth metal complexes, platinum complexes, and the like can be used for the layer 111(2).

[0206] [Phosphorescent material (blue)] 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 2 ]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]), and the like can be used.

[0207] 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]), and the like.

[0208] 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]), and the like.

[0209] Organometallic iridium complexes with phenylpyridine derivatives having electron-withdrawing groups as ligands 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(CF3ppy)2(pic)]), bis[2-(4',6'-difluorophenyl)pyridinato-N,C 2’ ] Iridium(III) acetylacetonate (abbreviation: FIracac), etc. can be used.

[0210] These compounds exhibit blue phosphorescence and have a peak emission wavelength between 440 nm and 520 nm.

[0211] [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)]), and the like can be used.

[0212] 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)]), and the like.

[0213] Organometallic iridium complexes with 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 2 )phenyl-κC]iridium(III) (abbreviation: [Ir(5mppy-d3)2(mbfpypy-d3)]), [2-d3-methyl-(2-pyridinyl-κN)benzofuro[2,3-b]pyridine-κC]bis[2-(2-pyridinyl-κN)phenyl-κC]iridium(III) (abbreviation: [Ir(ppy)2(mbfpypy-d3)]), and the like can be used.

[0214] Examples of rare earth metal complexes include tris(acetylacetonato)(monophenanthroline)terbium(III) (abbreviation: [Tb(acac)3(Phen)]).

[0215] These compounds mainly exhibit green phosphorescence, with a peak emission wavelength between 500 nm and 600 nm. Organometallic iridium complexes with a pyrimidine skeleton are also remarkably superior in terms of reliability and luminous efficiency.

[0216] [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)]), and bis[4,6-di(naphthalen-1-yl)pyrimidinato](dipivaloylmethanato)iridium(III) (abbreviation: [Ir(d1npm)2(dpm)]).

[0217] Examples of organometallic iridium complexes having a pyrazine skeleton that can be used 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)]), and (acetylacetonato)bis[2,3-bis(4-fluorophenyl)quinoxalinato]iridium(III) (abbreviation: [Ir(Fdpq)2(acac)]).

[0218] Organometallic iridium complexes with 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.

[0219] Examples of rare earth metal complexes that can be used 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)]), and the like.

[0220] 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.

[0221] These compounds exhibit red phosphorescence, with an emission peak between 600 nm and 700 nm. Organometallic iridium complexes with pyrazine skeletons emit red light with a chromaticity suitable for use in display devices.

[0222] [Substances that exhibit thermally activated delayed fluorescence (TADF)] A TADF material can be used for the layer 111(2). For example, the following TADF materials can be used as the light-emitting material. However, the present invention is not limited to these.

[0223] TADF materials have a small difference between the S1 and T1 levels, allowing reverse intersystem crossing (upconversion) from the triplet excited state to the singlet excited state with a small amount of thermal energy. This allows for efficient generation of the singlet excited state from the triplet excited state. The triplet excited energy can also be converted into light emission.

[0224] Furthermore, exciplexes (also known as exciplexes), which form an excited state with two types of substances, have an extremely small difference between the S1 and T1 levels and function as TADF materials that can convert triplet excitation energy into singlet excitation energy.

[0225] The T1 level can be determined by using a phosphorescence spectrum observed at low temperatures (for example, 10 K to 77 K). For a TADF material, when a tangent line is drawn at the base of the fluorescence spectrum on the short wavelength side and the energy of the wavelength of the extrapolated line is defined as the S1 level, and a tangent line is drawn at the base of the phosphorescence spectrum on the short wavelength side and the energy of the wavelength of the extrapolated line is defined as the T1 level, the difference between S1 and T1 is preferably 0.3 eV or less, and more preferably 0.2 eV or less.

[0226] 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.

[0227] For example, TADF materials can be made of 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.

[0228] Specifically, the following compounds, whose structural formulas are shown below, can be used: protoporphyrin-tin fluoride complex (SnF2(Proto IX)), mesoporphyrin-tin fluoride complex (SnF2(Meso IX)), hematoporphyrin-tin fluoride complex (SnF2(Hemato IX)), coproporphyrin tetramethyl ester-tin fluoride complex (SnF2(Copro III-4Me)), octaethylporphyrin-tin fluoride complex (SnF2(OEP)), etioporphyrin-tin fluoride complex (SnF2(Etio I)), octaethylporphyrin-platinum chloride complex (PtCl2OEP), etc.

[0229] [ka]

[0230] 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 a TADF material.

[0231] Specifically, the structural formulas are shown below: 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), etc. can be used.

[0232] [ka]

[0233] 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, pyridine skeletons, diazine skeletons (pyrimidine skeletons, pyrazine skeletons, pyridazine skeletons), and triazine skeletons are preferred because they are stable and reliable. In particular, benzofuropyrimidine skeletons, benzothienopyrimidine skeletons, benzofuropyrazine skeletons, and benzothienopyrazine skeletons are preferred because they have high acceptor properties and good reliability.

[0234] 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 and reliable. The dibenzofuran skeleton is preferable as the furan skeleton, and the dibenzothiophene skeleton is preferable as the thiophene skeleton. The indole skeleton, carbazole skeleton, indolocarbazole skeleton, bicarbazole skeleton, and 3-(9-phenyl-9H-carbazol-3-yl)-9H-carbazole skeleton are particularly preferable as the pyrrole skeleton.

[0235] 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.Instead of the π-electron-deficient heteroaromatic ring, an aromatic ring bonded to an electron-withdrawing group such as a cyano group may be used.In addition, an aromatic amine skeleton, a phenazine skeleton, or the like may be used as the π-electron-rich skeleton.

[0236] 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.

[0237] 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.

[0238] <<Configuration Example 2 of Layer 111(2)>> 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 TADF material, a material having an anthracene skeleton, a mixed material, or the like can be used as the host material. Note that a material having a larger band gap than the light-emitting material contained in the layer 111(2) is preferably used as the host material. This can suppress energy transfer from excitons generated in the layer 111(2) to the host material.

[0239] [Hole-transporting materials] The hole mobility is 1×10 -6 cm 2 A material having a Vs value of 1 / Vs or more can be suitably used as a material having hole transport properties.

[0240] For example, the layer 111(2) can be formed using a material having a hole-transport property that can be used for the layer 112. Specifically, the layer 111(2) can be formed using a material having a hole-transport property that can be used for a hole-transport layer.

[0241] For example, the layer 111(2) can be formed using a material having an electron-transporting property that can be used for the layer 105. Specifically, the layer 111(2) can be formed using a material having an electron-transporting property that can be used for an electron-injection layer.

[0242] [Materials with anthracene skeleton] An organic compound having an anthracene skeleton can be used as a host material. In particular, when a fluorescent material is used as the light-emitting material, an organic compound having an anthracene skeleton is suitable. This allows for the realization of a light-emitting device with good luminous efficiency and durability.

[0243] As organic compounds having an anthracene skeleton, organic compounds having a diphenylanthracene skeleton, particularly a 9,10-diphenylanthracene skeleton, are preferred due to their chemical stability. Furthermore, host materials having a carbazole skeleton are preferred because of their enhanced hole injection and transport properties. In particular, host materials containing a dibenzocarbazole skeleton are preferred because their HOMO level is approximately 0.1 eV shallower than that of carbazole, making it easier for holes to enter, and they also have excellent hole transport properties and high heat resistance. From the perspective of hole injection and transport properties, a benzofluorene skeleton or a dibenzofluorene skeleton may be used instead of the carbazole skeleton.

[0244] 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.

[0245] 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), etc. can be used.

[0246] In particular, CzPA, cgDBCzPA, 2mBnfPPA, and PCzPA exhibit very good properties.

[0247] [Substances that exhibit thermally activated delayed fluorescence (TADF)] TADF materials can be used as host materials. When TADF materials are used as host materials, triplet excitation energy generated in the TADF material can be converted to singlet excitation energy through reverse intersystem crossing. Furthermore, the excitation energy can be transferred to the 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 light-emitting devices.

[0248] This is very effective when the luminescent material is a fluorescent luminescent material. In this case, in order to obtain high luminous efficiency, the S1 level of the TADF material is preferably higher than the S1 level of the fluorescent luminescent material. In addition, the T1 level of the TADF material is preferably higher than the S1 level of the fluorescent luminescent material. Therefore, the T1 level of the TADF material is preferably higher than the T1 level of the fluorescent luminescent material.

[0249] It is also preferable to use a TADF material that emits light that overlaps with the wavelength of the lowest-energy absorption band of the fluorescent material, as this allows for smooth transfer of excitation energy from the TADF material to the fluorescent material, resulting in efficient light emission.

[0250] Furthermore, to efficiently generate singlet excitation energy from triplet excitation energy through reverse intersystem crossing, carrier recombination is preferred in the TADF material. Furthermore, it is preferable that the triplet excitation energy generated in the TADF material does not transfer to triplet excitation energy in the fluorescent material. To achieve this, the fluorescent material preferably has a protecting group around the luminophore (the skeleton responsible for light emission) of the fluorescent material. The protecting group is preferably a substituent without a π bond, and is preferably a saturated hydrocarbon. Specific examples include alkyl groups with 3 to 10 carbon atoms, substituted or unsubstituted cycloalkyl groups with 3 to 10 carbon atoms, and trialkylsilyl groups with 3 to 10 carbon atoms. It is even more preferable to have multiple protecting groups. Substituents without a π bond have poor carrier transport properties, so they can increase the distance between the TADF material and the luminophore of the fluorescent material without significantly affecting carrier transport or carrier recombination.

[0251] 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.

[0252] 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.

[0253] For example, a TADF material that can be used as a light-emitting material can be used as a host material.

[0254] [Mixed material composition example 1] Alternatively, a mixture of multiple substances can be used as the host material. For example, a material having electron transport properties and a material having hole transport properties can be used as the mixture. The weight ratio of the material having hole transport properties to the material having electron transport properties contained in the mixture may be 1:19 to 19:1 (material having hole transport properties: material having electron transport properties). This allows easy adjustment of the carrier transport properties of the layer 111(2). Furthermore, the recombination region can be easily controlled.

[0255] [Mixed material composition example 2] A material containing a phosphorescent emitting substance can be used as a host material. When a fluorescent emitting substance is used as an emitting substance, the phosphorescent emitting substance can be used as an energy donor that provides excitation energy to the fluorescent emitting substance.

[0256] A mixed material containing a material that forms an exciplex can be used as the 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 substance can be used as the host material. This allows for smooth energy transfer, improving luminous efficiency and reducing driving voltage.

[0257] 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.

[0258] 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 the electrochemical properties (reduction potential and oxidation potential). Specifically, the reduction potential and oxidation potential can be measured using cyclic voltammetry (CV) measurement.

[0259] The formation of exciplexes can be confirmed by, for example, comparing the emission spectra of a hole-transporting material, an electron-transporting material, and a mixed film of these materials and observing the phenomenon that the emission spectrum of the mixed film is shifted to longer wavelengths than the emission spectra of each material (or has a new peak at longer wavelengths). Alternatively, it can be confirmed by comparing the transient photoluminescence (PL) of a hole-transporting material, the transient PL of an electron-transporting material, and a mixed film of these materials and observing differences in transient response, such as the transient PL lifetime of the mixed film having a longer-lived component or a larger proportion of delayed components than the transient PL lifetimes of the individual materials. The above-mentioned transient PL can also be interpreted as transient electroluminescence (EL). In other words, the formation of exciplexes can also be confirmed by comparing the transient EL of a hole-transporting material, the transient EL of an electron-transporting material, and a mixed film of these materials and observing differences in transient response.

[0260] Note that this embodiment mode can be appropriately combined with other embodiment modes described in this specification.

[0261] (Embodiment 7) In this embodiment, a structure of a functional panel 700 according to one embodiment of the present invention will be described with reference to FIG.

[0262] <Configuration example 1 of function panel 700> The functional panel 700 described in this embodiment has a light-emitting device 150 and an optical functional device 170 (see FIG. 4(A)).

[0263] For example, the light-emitting devices described in the first to fifth embodiments can be used as the light-emitting device 150 .

[0264] <Configuration example of the optical functional device 170> The optical functional device 170 described in this embodiment includes an electrode 101S, an electrode 102, and a unit 103S. The electrode 102 has an area overlapping with the electrode 101S, and the unit 103S has an area sandwiched between the electrode 101S and the electrode 102.

[0265] The optical functional device 170 also includes a layer 104 and a layer 105. The layer 104 includes a region sandwiched between the electrode 101S and the unit 103S, and the layer 105 includes a region sandwiched between the unit 103S and the electrode 102. Note that part of the configuration of the light-emitting device 150 can be used as part of the configuration of the optical functional device 170. This allows part of the configuration to be shared, or simplifies the manufacturing process.

[0266] <Configuration example 1 of Unit 103S> The unit 103S has a single layer structure or a laminated structure, for example, the unit 103S has a layer 114, a layer 112, and a layer 113 (see FIG. 4(A)).

[0267] Layer 114 comprises a region sandwiched between layers 112 and 113, layer 112 comprises a region sandwiched between electrode 101S and layer 114, and layer 113 comprises a region sandwiched between electrode 102 and layer 114.

[0268] For example, the unit 103S 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 may be a layer selected from functional layers such as an exciton blocking layer and a charge generating layer.

[0269] The unit 103S absorbs light hv and supplies electrons to one electrode and holes to the other electrode. For example, the unit 103S supplies holes to the electrode 101S and electrons to the electrode 102.

[0270] Example of Layer 112 For example, a material having a hole-transporting 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.

[0271] 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.

[0272] <<Configuration Example 1 of Layer 114>> For example, an electron-accepting material and an electron-donating material can be used for the layer 114. Specifically, a material that can be used for an organic solar cell can be used for the layer 114. The layer 114 can also be called a photoelectric conversion layer. The layer 114 absorbs light hv and supplies electrons to one electrode and holes to the other electrode. For example, the layer 114 supplies holes to the electrode 101S and electrons to the electrode 102.

[0273] [Examples of electron-accepting materials] For example, fullerene derivatives, non-fullerene electron acceptors, etc. can be used as the electron-accepting material.

[0274] As an electron-accepting material, C 60 Fullerene, C 70 Fullerene, [6,6]-phenyl-C 71 -Butyric acid methyl ester (abbreviation: PC71BM), [6,6]-phenyl-C 61-butyric acid methyl ester (abbreviation: PC61BM), 1',1'',4',4''-tetrahydro-di[1,4]methanonaphthaleno[1,2:2',3',56,60:2'',3''][5,6]fullerene-C 60 (abbreviation: ICBA) etc. can be used.

[0275] 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).

[0276] [Examples of electron-donating materials] For example, phthalocyanine compounds, tetracene derivatives, quinacridone derivatives, rubrene derivatives, etc. can be used as electron donating materials.

[0277] 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.

[0278] <<Configuration Example 2 of Layer 114>> For example, a single layer structure or a stacked layer structure can be used for the layer 114. Specifically, a bulk heterojunction structure can be used for the layer 114. Alternatively, a heterojunction structure can be used for the layer 114.

[0279] [Example of mixed material composition] For example, a mixed material containing an electron-accepting material and an electron-donating material can be used for the layer 114. Note that a structure in which a mixed material containing an electron-accepting material and an electron-donating material is used for the layer 114 can be referred to as a bulk heterojunction type.

[0280] Specifically, C 70 A composite material including fullerenes and DBP can be used for layer 114 .

[0281] [Example of heterozygous type] Layer 114N and layer 114P can be used for layer 114. Layer 114N includes a region sandwiched between one electrode and layer 114P, and layer 114P includes a region sandwiched between layer 114N and the other electrode. For example, layer 114N includes a region sandwiched between electrode 102 and layer 114P, and layer 114P includes a region sandwiched between layer 114N and electrode 101S (see FIG. 4(B)).

[0282] An n-type semiconductor can be used for the layer 114N. For example, Me-PTCDI can be used for the layer 114N.

[0283] Alternatively, a p-type semiconductor can be used for the layer 114P. For example, rubrene can be used for the layer 114P.

[0284] The optical functional device 170 having a configuration in which the layer 114P is in contact with the layer 114N can be called a PN junction photodiode.

[0285] <Configuration example 2 of unit 103S> The unit 103S includes a layer 111(2), and the layer 111(2) includes a region sandwiched between the layer 114 and the layer 113 (see FIG. 4(C)).

[0286] Structural example 2 of unit 103S differs from structural example 1 of unit 103S in that it includes layer 111(2). Here, the different parts will be described in detail, and the above description will be used for parts having the same configuration.

[0287] <<Configuration Example 3 of Layer 111(2)>> For example, a light-emitting material or a light-emitting material and a host material can be used in the layer 111(2). The layer 111(2) can also be called a light-emitting layer. It is preferable to arrange the layer 111(2) in a region where holes and electrons recombine. This allows the energy generated by carrier recombination to be efficiently converted into light and emitted. It is also preferable to arrange the layer 111(2) away from metals used in electrodes, etc. This can suppress the quenching phenomenon caused by metals used in electrodes, etc.

[0288] Specifically, the configuration described in the sixth embodiment can be used for the layer 111(2). In particular, a configuration that emits light with a wavelength that is not easily absorbed by the layer 114 can be suitably used for the layer 111(2). This allows the light EL2 emitted by the layer 111(2) to be extracted with high efficiency.

[0289] Note that this embodiment mode can be appropriately combined with other embodiment modes described in this specification.

[0290] (Embodiment 8) In this embodiment, a light-emitting device using the light-emitting device described in any one of Embodiments 1 to 6 will be described.

[0291] In this embodiment, a light-emitting device manufactured using the light-emitting device described in any one of Embodiments 1 to 6 will be described with reference to FIG. 5. FIG. 5A is a top view showing the light-emitting device, and FIG. 5B is a cross-sectional view taken along lines AB and CD in FIG. 5A. This light-emitting device includes a driver circuit section (source line driver circuit 601), a pixel section 602, and a driver circuit section (gate line driver circuit 603), all of which are shown by dotted lines and serve to control light emission from the light-emitting device. Also, 604 denotes a sealing substrate, 605 denotes a sealant, and the inside surrounded by the sealant 605 forms a space 607.

[0292] 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.

[0293] Next, the cross-sectional structure will be described with reference to Fig. 5(B) . A driver circuit portion and a pixel portion are formed on an element substrate 610, but here, a source line driver circuit 601, which is the driver circuit portion, and one pixel in a pixel portion 602 are shown.

[0294] The element substrate 610 may be made of a substrate made of glass, quartz, organic resin, metal, alloy, semiconductor, or a plastic substrate made of FRP (Fiber Reinforced Plastics), PVF (Polyvinyl Fluoride), polyester, acrylic resin, or the like.

[0295] The structure of the transistor used in the pixel or the driver circuit is not particularly limited. For example, it may be an inverted staggered transistor or a staggered transistor. Furthermore, it may be a top-gate transistor or a bottom-gate transistor. The semiconductor material used for the transistor is not particularly limited, and for example, silicon, germanium, silicon carbide, gallium nitride, or the like may be used. 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.

[0296] 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.

[0297] Here, it is preferable to use an oxide semiconductor for semiconductor devices such as transistors provided in the pixel or driver circuit, as well 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.

[0298] The oxide semiconductor preferably contains at least indium (In) or zinc (Zn), and more preferably contains an oxide represented by In-M-Zn oxide (M is a metal such as Al, Ti, Ga, Ge, Y, Zr, Sn, La, Ce, or Hf).

[0299] In particular, it is preferable to use, as the semiconductor layer, an oxide semiconductor film having a plurality of crystal parts whose c-axes are oriented perpendicular to the surface on which the semiconductor layer is formed or the top surface of the semiconductor layer and which does not have grain boundaries between adjacent crystal parts.

[0300] By using such a material for the semiconductor layer, fluctuations in electrical characteristics are suppressed, and a highly reliable transistor can be realized.

[0301] 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.

[0302] To stabilize the characteristics of the transistor, it is preferable to provide an underlayer film. The underlayer film can be formed as a single layer or a multilayer 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 underlayer 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 underlayer film need not be provided if it is not necessary.

[0303] Note that 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.

[0304] Furthermore, the pixel portion 602 is formed by a plurality of pixels each 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 capacitive element.

[0305] An insulator 614 is formed to cover an end portion of the first electrode 613. Here, the insulator 614 can be formed using a positive photosensitive acrylic resin film.

[0306] 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 for 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.

[0307] An EL layer 616 and a second electrode 617 are formed on the first electrode 613. The first electrode 613, which functions as an anode, is preferably made of a material with a large work function. Examples of the material include 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. Other examples include a laminated structure of a titanium nitride film and a film mainly composed of aluminum, and a three-layer structure of a titanium nitride film, a film mainly composed of aluminum, and a titanium nitride film. The laminated structure provides low wiring resistance, good ohmic contact, and the first electrode 613 can function as an anode.

[0308] The EL layer 616 is formed by various methods such as a vapor deposition method using a vapor deposition mask, an inkjet method, or a spin coating method. The EL layer 616 includes the structure described in any one of Embodiments 1 to 6. Other materials constituting the EL layer 616 may be low-molecular compounds or high-molecular compounds (including oligomers and dendrimers).

[0309] Furthermore, the second electrode 617, which is formed on the EL layer 616 and functions as a cathode, is preferably made of a material with a small work function (such as Al, Mg, Li, or Ca, or an alloy or compound thereof (MgAg, MgIn, AlLi, etc.)). When light generated in the EL layer 616 is transmitted through the second electrode 617, the second electrode 617 is preferably made of a laminate of a thin metal thin film and a transparent conductive film (such as ITO, indium oxide containing 2 wt % to 20 wt % zinc oxide, indium tin oxide containing silicon, or zinc oxide (ZnO)).

[0310] 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 6. 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 6 and light-emitting devices having other structures.

[0311] Furthermore, by bonding the sealing substrate 604 to the element substrate 610 with a sealant 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 sealant 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 sealant. A recess is formed in the sealing substrate, and by providing a desiccant there, deterioration due to the influence of moisture can be suppressed, which is a preferable configuration.

[0312] It is preferable to use epoxy resin or glass frit for the sealing material 605. It is also desirable that these materials are as moisture and oxygen impermeable as possible. In addition to glass or quartz substrates, plastic substrates made of FRP (Fiber Reinforced Plastics), PVF (Polyvinyl Fluoride), polyester, acrylic resin, or the like can be used for the sealing substrate 604.

[0313] Although not shown in Figures 5(A) and 5(B), 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.

[0314] 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.

[0315] 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.

[0316] 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. In addition, it is possible to reduce damage to the workpiece when forming the protective film.

[0317] 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.

[0318] In the above manner, a light-emitting device manufactured using the light-emitting device described in any one of Embodiments 1 to 6 can be obtained.

[0319] 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 6. Specifically, the light-emitting device described in any one of Embodiments 1 to 6 has favorable emission efficiency, and therefore can have low power consumption.

[0320] 6A and 6B show 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. Fig. 6A 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, a first electrode 1024W, a first electrode 1024R, a first electrode 1024G, a first electrode 1024B of the light-emitting device, a partition wall 1025, an EL layer 1028, a second electrode 1029 of the light-emitting device, a sealing substrate 1031, a sealant 1032, and the like.

[0321] In FIG. 6(A), the colored layers (a red colored layer 1034R, a green colored layer 1034G, and a blue colored layer 1034B) are provided on a transparent base material 1033. A black matrix 1035 may also be provided. The transparent base material 1033 on which the colored layers and the black matrix are provided is aligned and fixed to the substrate 1001. The colored layers and the black matrix 1035 are covered with an overcoat layer 1036. In FIG. 6(A), 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 displayed using four color pixels.

[0322] 6(B) 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 way, the colored layers may be provided between the substrate 1001 and the sealing substrate 1031.

[0323] Furthermore, the light-emitting device described above has a structure in which light is extracted from the substrate 1001 side on which the FET is formed (bottom emission type), but it may also have a structure in which light is extracted from the sealing substrate 1031 side (top emission type). A cross-sectional view of a top emission type light-emitting device is shown in FIG. 7. 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 up to the formation of a connection electrode that connects the FET and the anode of the light-emitting device. 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.

[0324] The first electrodes 1024W, 1024R, 1024G, and 1024B of the light-emitting device are anodes in this example, but may be cathodes. In the case of a top-emission light-emitting device as shown in FIG. 7, the first electrodes are preferably reflective electrodes. The EL layer 1028 has a structure similar to that described for the unit 103 in any one of Embodiments 1 to 6, and has an element structure that allows white light emission.

[0325] In the top-emission structure shown in FIG. 7, 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). The sealing substrate 1031 may be provided with a black matrix 1035 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. In addition, although 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.

[0326] 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-transmissive / semi-reflective electrode as the second electrode. At least an EL layer is provided between the reflective electrode and the semi-transmissive / semi-reflective electrode, and at least an emissive layer that serves as the light-emitting region is provided.

[0327] 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 resistance of Ωcm or less.

[0328] The 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.

[0329] In this light-emitting device, the optical distance between the reflective electrode and the semi-transmissive / 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 resonant wavelengths and attenuate light of non-resonant wavelengths between the reflective electrode and the semi-transmissive / semi-reflective electrode.

[0330] 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 greater than or equal to 1, and λ is the wavelength of the emitted light to be amplified). By adjusting this optical distance, the phases of the first reflected light and the first incident light can be matched, thereby further amplifying the light emitted from the light-emitting layer.

[0331] 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.

[0332] The microcavity structure makes it possible to increase the light emission intensity of specific wavelengths 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, not only is the yellow light emitted effective in improving brightness, but 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.

[0333] 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 6. Specifically, the light-emitting device described in any one of Embodiments 1 to 6 has favorable emission efficiency, and therefore can have low power consumption.

[0334] Up to this point, active matrix light-emitting devices have been described. From here on, passive matrix light-emitting devices will be described. FIG. 8 shows a passive matrix light-emitting device manufactured by applying the present invention. FIG. 8(A) is a perspective view showing the light-emitting device, and FIG. 8(B) is a cross-sectional view taken along the XY line in FIG. 8(A). In FIG. 8, 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 6 can be a highly reliable light-emitting device or a light-emitting device with low power consumption.

[0335] 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.

[0336] This embodiment mode can be freely combined with other embodiment modes.

[0337] (Embodiment 9) In this embodiment, an example in which the light-emitting device described in any one of Embodiments 1 to 6 is used as a lighting device will be described with reference to Fig. 9. Fig. 9(B) is a top view of the lighting device, and Fig. 9(A) is a cross-sectional view taken along line ef in Fig. 9(B).

[0338] In the lighting device of 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 6. When light is extracted from the first electrode 401 side, the first electrode 401 is formed using a light-transmitting material.

[0339] A pad 412 for supplying a voltage to the second electrode 404 is formed on the substrate 400 .

[0340] An EL layer 403 is formed on the first electrode 401. The EL layer 403 corresponds to the configuration of the layer 104, the unit 103, and the layer 105 in any one of Embodiments 1 to 6, or the configuration of the layer 104, the unit 103, the intermediate layer 106, the unit 103(2), and the layer 105. For details of these configurations, see the relevant descriptions.

[0341] 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 6. 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.

[0342] 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 be a lighting device with low power consumption.

[0343] The lighting device is completed by bonding and sealing the substrate 400 on which the light-emitting device having the above structure is formed and a sealing substrate 407 using sealants 405 and 406. Either one of the sealants 405 and 406 may be used. Also, a desiccant may be mixed into the inner sealant 406 (not shown in FIG. 9(B)), which can absorb moisture and improve reliability.

[0344] Furthermore, the pad 412 and a part of the first electrode 401 can be extended outside the sealing materials 405 and 406 to serve as an external input terminal. An IC chip 420 equipped with a converter or the like may also be provided thereon.

[0345] As described above, the lighting device described in this embodiment uses the light-emitting device described in any one of Embodiments 1 to 6 as an EL element, and can be a lighting device with low power consumption.

[0346] (Embodiment 10) In this embodiment, an example of an electronic device including a light-emitting device described in any one of Embodiments 1 to 6 will be described. The light-emitting device described in any one of Embodiments 1 to 6 has high emission 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.

[0347] 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 players, large game machines such as pachinko machines, etc. Specific examples of these electronic devices are shown below.

[0348] 10A illustrates an example of a television set. The television set includes a display portion 7103 built in a housing 7101. Here, the housing 7101 is supported by a stand 7105. The display portion 7103 can display images, and the light-emitting devices described in any one of Embodiments 1 to 6 are arranged in a matrix.

[0349] The television set can be operated using operation switches provided on the housing 7101 or a separate remote control 7110. Operation keys 7109 provided on the remote control 7110 can be used to control the channel or volume and to control the image displayed on the display portion 7103. The remote control 7110 may be provided with a display portion 7107 that displays information output from the remote control 7110.

[0350] 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.

[0351] FIG. 10B 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 6 arranged in a matrix for the display portion 7203. The computer in FIG. 10B may have a configuration as shown in FIG. 10C. The computer in FIG. 10C is provided with a second display portion 7210 instead of the keyboard 7204 and the pointing device 7206. The second display portion 7210 has a touch panel, 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 the screens from being scratched or broken during storage or transportation.

[0352] 10D shows an example of a mobile terminal. The mobile terminal includes a display portion 7402 built 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 6 are arranged in a matrix.

[0353] 10D 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 e-mail can be performed by touching the display portion 7402 with a finger or the like.

[0354] The screen of the display unit 7402 has three main modes. The first is a display mode that mainly displays images, the second is an input mode that mainly inputs information such as characters, and the third is a display+input mode that combines the display mode and the input mode.

[0355] For example, when making a call or creating an e-mail, 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.

[0356] Furthermore, by providing a detection device having a sensor for detecting 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.

[0357] 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.

[0358] In addition, in the input mode, a signal detected by an optical sensor of 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.

[0359] 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, 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.

[0360] FIG. 11(A) is a schematic diagram showing an example of a cleaning robot.

[0361] 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 also has 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 also has wireless communication means.

[0362] 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.

[0363] Furthermore, the cleaning robot 5100 can analyze the image captured by the camera 5102 to determine whether there are any obstacles such as walls, furniture, or steps. Furthermore, if the image analysis detects an object that may become tangled in the brush 5103, such as a wire, the rotation of the brush 5103 can be stopped.

[0364] 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 also 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.

[0365] 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. Therefore, the owner of the cleaning robot 5100 can know the state of the room even when he or she is away from home. In addition, the display on the display 5101 can be confirmed on the portable electronic device 5140 such as a smartphone.

[0366] The light-emitting device according to one embodiment of the present invention can be used for the display 5101 .

[0367] The robot 2100 shown in FIG. 11(B) 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.

[0368] The microphone 2102 has a function of detecting the user's speaking 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.

[0369] 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.

[0370] 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.

[0371] 11C 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 ray), a microphone 5008, a display unit 5002, a support unit 5012, and earphones 5013.

[0372] The light-emitting device of one embodiment of the present invention can be used for the display portion 5001 and the display portion 5002 .

[0373] 12 shows an example in which the light-emitting device described in any one of Embodiments 1 to 6 is used in a desk lamp, which is a lighting device. The desk lamp shown in FIG. 12 includes a housing 2001 and a light source 2002, and the lighting device described in Embodiment 9 may be used as the light source 2002.

[0374] FIG. 13 shows an example in which the light-emitting device described in any one of Embodiments 1 to 6 is used as an indoor lighting device 3001. The light-emitting device described in any one of Embodiments 1 to 6 has high emission efficiency and therefore can be used as a lighting device with low power consumption. Furthermore, the light-emitting device described in any one of Embodiments 1 to 6 can be made large-area and therefore can be used as a large-area lighting device. Furthermore, the light-emitting device described in any one of Embodiments 1 to 6 is thin and therefore can be used as a thin lighting device.

[0375] The light-emitting device described in any one of Embodiments 1 to 6 can also be mounted on a windshield or a dashboard of an automobile. Figure 14 shows one mode in which the light-emitting device described in any one of Embodiments 1 to 6 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 6.

[0376] 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 6. The light-emitting device described in any one of Embodiments 1 to 6 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 is provided for driving the device, 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.

[0377] 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 6. By displaying an image from an imaging means provided on the vehicle body in the display area 5202, the view blocked by the pillar can be complemented. 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. By displaying an image to complement the invisible parts, safety can be confirmed more naturally and without discomfort.

[0378] 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.

[0379] 15(A) to 15(C) show a foldable mobile information terminal 9310. Fig. 15(A) shows the mobile information terminal 9310 in an unfolded state. Fig. 15(B) shows the mobile information terminal 9310 in a state in the process of changing from one of an unfolded state and a folded state to the other. Fig. 15(C) shows the mobile information terminal 9310 in a folded state. The mobile 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.

[0380] 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). The display panel 9311 can be reversibly transformed from an unfolded state of the mobile information terminal 9310 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.

[0381] 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 6.

[0382] As described above, the light-emitting device including the light-emitting device described in any one of Embodiments 1 to 6 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 6, electronic devices with low power consumption can be obtained.

[0383] Note that this embodiment mode can be appropriately combined with other embodiment modes described in this specification. [Example]

[0384] In this example, structures of 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.

[0385] FIG. 16 is a diagram illustrating the configuration of a light-emitting device.

[0386] FIG. 17 is a diagram illustrating the emission spectrum of the luminescent material according to the example.

[0387] FIG. 18 is a diagram illustrating the wavelength-refractive index characteristics of the organic compound ETM according to the example.

[0388] FIG. 19 is a diagram illustrating the current density-luminance characteristics of a light-emitting device.

[0389] FIG. 20 is a diagram illustrating the luminance-current efficiency characteristics of a light-emitting device.

[0390] FIG. 21 is a diagram illustrating the voltage-luminance characteristics of a light-emitting device.

[0391] FIG. 22 is a diagram illustrating the voltage-current characteristics of a light-emitting device.

[0392] FIG. 23 illustrates the luminance-blue index characteristics of a light-emitting device. The blue index (BI) is the current efficiency (cd / A) divided by the y chromaticity and is one index that represents the luminance characteristics of blue light emission. The smaller the y chromaticity, the higher the color purity of blue light emission tends to be. Blue light emission with high color purity can express a wide range of blue colors even with a small luminance component. Using blue light emission with high color purity reduces the required luminance to express blue, thereby reducing power consumption. Therefore, the BI, which takes into account the y chromaticity, which is one index of blue purity, is preferably used as a means of expressing the efficiency of blue light emission. Therefore, it can be said that a light-emitting device with a higher BI has better efficiency as a blue light-emitting device used in a display.

[0393] Figure 24 shows the light-emitting device with a luminance of 1000 cd / m 2 10 is a diagram illustrating an emission spectrum when light is emitted at a luminance of 1000 .mu.m.

[0394] <Light-emitting device 1> The light-emitting device 1 fabricated in this example has the same configuration as the light-emitting device 150 (see FIG. 16).

[0395] Light-emitting device 150 has electrode 101, electrode 102, and unit 103. Electrode 102 has an area overlapping with electrode 101, and unit 103 has an area sandwiched between electrode 101 and electrode 102. Unit 103 has layers 111, 112, and 113. It also has layers 104 and 105.

[0396] Layer 111 includes a region sandwiched between electrode 101 and electrode 102, and includes a light-emitting material. The light-emitting material emits photoluminescent light, and the photoluminescent light has a first spectrum φ1. The first spectrum φ1 has a maximum peak at wavelength λ1, which is in the range of 440 nm to 470 nm. Specifically, 3,10-bis[N-(9-phenyl-9H-carbazol-2-yl)-N-phenylamino]naphtho[2,3-b;6,7-b']bisbenzofuran (abbreviated as 3,10PCA2Nbf(IV)-02) was used as the light-emitting material. The emission spectrum of 3,10PCA2Nbf(IV)-02 is shown in Figure 17. The maximum peak of the emission spectrum of 3,10PCA2Nbf(IV)-02 in a toluene solution is at 448 nm, in the range of 440 nm to 470 nm. The full width at half maximum (FWHM) is 26 nm, in the range of 10 nm to 35 nm. The photoluminescence spectrum of the luminescent material was measured at room temperature using a fluorometer (FP-8600, manufactured by JASCO Corporation).

[0397] Layer 112 comprises the area sandwiched between electrode 101 and layer 111 .

[0398] Layer 113 has a region sandwiched between layer 111 and electrode 102. Layer 113 contains an organic compound ETM. The organic compound ETM has a first refractive index n1 for light having a wavelength λ1, and the first refractive index n1 is 1.4 or more and 1.75 or less. Specifically, 2-{(3',5'-di-tert-butyl)-1,1'-biphenyl-3-yl}-4,6-diphenyl-1,3,5-triazine (abbreviated as mmtBumBPTzn) was used as the organic compound ETM. Figure 18 shows the wavelength-refractive index characteristics of mmtBumBPTzn. The refractive index of ordinary light, n,Ordinary, is also shown. The refractive index of mmtBumBPTzn is in the range of 1.67 to 1.68 in the wavelength range of 440 nm to 470 nm, and is 1.4 or more and 1.75 or less. The samples were prepared by depositing each layer of material onto a quartz substrate to a thickness of approximately 50 nm using vacuum deposition. The refractive index of the samples was then measured using a spectroscopic ellipsometer (J.A. Woollam Japan M-2000U). The refractive index of ordinary light, n,Ordinary, is shown.

[0399] The light-emitting device 1 also includes a layer 104 and a layer 105 , where the layer 104 includes a region sandwiched between the unit 103 and the electrode 101 , and the layer 105 includes a region sandwiched between the electrode 102 and the unit 103 .

[0400] <Configuration of Light-Emitting Device 1> The configuration of the 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.

[0401] [Table 1]

[0402] [ka]

[0403] [ka]

[0404] <Method for producing light-emitting device 1> The light-emitting device 1 described in this example was fabricated using a method having the following steps.

[0405] [First Step] In the first step, the reflective film REF was formed by sputtering using an alloy containing silver, palladium, and copper (abbreviated as APC) as a target.

[0406] The reflective film REF includes APC and has a thickness of 100 nm.

[0407] [Second step] In the second step, the electrode 101 was formed on the reflective film REF. Specifically, the electrode 101 was formed by sputtering using indium oxide-tin oxide (abbreviated as ITSO) containing silicon or silicon oxide as a target.

[0408] The electrode 101 includes ITSO, has a thickness of 85 nm, and is 4 mm 2 It has an area of ​​(2mm x 2mm).

[0409] 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 placed in a vacuum deposition apparatus whose internal pressure had been reduced to about Pa, and vacuum baking was carried out 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.

[0410] [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.

[0411] Layer 104 contains N-(1,1'-biphenyl-4-yl)-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-9,9-dimethyl-9H-fluoren-2-amine (abbreviated as PCBBiF) and an electron acceptor material (abbreviated as OCHD-003) in a weight ratio of PCBBiF:OCHD-003 = 1:0.05, and has a thickness of 10 nm. OCHD-003 contains fluorine, has acceptor properties, and has a molecular weight of 672.

[0412] [Fourth step] In the fourth step, a layer 112A was formed on the layer 104. Specifically, the material was evaporated using a resistive heating method.

[0413] Note that layer 112A includes PCBBiF and has a thickness of 20 nm.

[0414] [5th ​​step] In the fifth step, layer 112B was formed on layer 112A by evaporating the material using a resistive heating method.

[0415] The layer 112B contains N,N-bis[4-(dibenzofuran-4-yl)phenyl]-4-amino-p-terphenyl (abbreviation: DBfBB1TP) and has a thickness of 10 nm.

[0416] [Sixth step] In the sixth step, a layer 112C was formed on the layer 112B by evaporating the material using a resistive heating method.

[0417] The layer 112C contains 3,3'-(naphthalene-1,4-diyl)bis(9-phenyl-9H-carbazole) (abbreviation: PCzN2) and has a thickness of 10 nm.

[0418] [Seventh step] In the seventh step, the layer 111 was formed on the layer 112C by co-evaporation of materials using a resistance heating method.

[0419] The layer 111 contains 2-(10-phenyl-9-anthracenyl)-benzo[b]naphtho[2,3-d]furan (abbreviation: Bnf(II)PhA) and 3,10PCA2Nbf(IV)-02 in a weight ratio of Bnf(II)PhA:3,10PCA2Nbf(IV)-02 = 1:0.015, and has a thickness of 25 nm.

[0420] [Eighth Step] In the eighth step, a layer 113A was formed on the layer 111. Specifically, the material was evaporated using a resistance heating method.

[0421] The layer 113A includes mmtBumBPTzn and has a thickness of 10 nm.

[0422] [9th step] In the ninth step, the layer 113B was formed on the layer 113A by co-evaporation of materials using a resistance heating method.

[0423] The layer 113B contains mmtBumBPTzn and 8-hydroxyquinolinato-lithium (abbreviation: Liq) in a weight ratio of mmtBumBPTzn:Liq=0.5:0.5, and has a thickness of 20 nm.

[0424] [Step 10] In the tenth step, the layer 105 was formed on the layer 113B by depositing the material using a resistive heating method.

[0425] The layer 105 contains Liq and has a thickness of 1 nm.

[0426] [Step 11] In the eleventh step, the electrode 102 was formed on the layer 105. Specifically, materials were co-evaporated using a resistance heating method.

[0427] The electrode 102 contains Ag and Mg at a volume ratio of Ag:Mg=10:1, and has a thickness of 15 nm.

[0428] [12th Step] In the twelfth step, a layer CAP was formed on the electrode 102. Specifically, the material was evaporated using a resistive heating method.

[0429] The layer CAP contains 1,3,5-tri(dibenzothiophen-4-yl)-benzene (abbreviation: DBT3PII) and has a thickness of 70 nm.

[0430] <<Operation characteristics of light-emitting device 1>> When power was supplied, the light emitting device 1 emitted light EL1 (see FIG. 16). The operating characteristics of the light emitting device 1 were measured (see FIGS. 19 to 24). The measurements were carried out at room temperature.

[0431] Light-emitting device 1 is set at a brightness of 1000 cd / m 2 Table 2 shows the main initial characteristics when the device was made to emit light at about this temperature. The luminance, CIE chromaticity, and emission spectrum were measured using a spectroradiometer (SR-UL1R, manufactured by Topcon Corporation) at room temperature. (Note that the initial characteristics of other light-emitting devices are also listed in Table 2, and their configurations will be described later.)

[0432] [Table 2]

[0433] The blue index (BI) is a value obtained by dividing the current efficiency (cd / A) by the y chromaticity, and is one of the indices that express the luminous characteristics of blue light emission. The smaller the y chromaticity, the higher the color purity of blue light emission tends to be. Blue light emission with high color purity can express a wide range of blue colors even with a small luminance component. Using blue light emission with high color purity reduces the required luminance to express blue, thereby reducing power consumption. Therefore, the BI, which takes into account the y chromaticity, an index of blue purity, is preferably used as a means of expressing the efficiency of blue light emission. It can be said that light-emitting devices with a higher BI have better efficiency as blue light-emitting devices used in displays.

[0434] <Light-emitting device 2> The light-emitting device 2 fabricated in this example differs from the light-emitting device 1 in the configurations of the layer 113A, the layer 113B, and the layer 105.

[0435] <Configuration of Light-Emitting Device 2> The configuration of light-emitting device 2 is shown in Table 3. 2-{(3',5'-di-tert-butyl)-1,1'-biphenyl-3-yl}-4,6-bis(3,5-di-tert-butylphenyl)-1,3,5-triazine (abbreviated as mmtBumBP-dmmtBuPTzn) was used as the organic compound ETM. The wavelength-refractive index characteristics of mmtBumBP-dmmtBuPTzn are shown in Figure 18. The refractive index of mmtBumBP-dmmtBuPTzn is in the range of 1.60 to 1.61 in the wavelength range of 440 nm to 470 nm, and is between 1.4 and 1.75.

[0436] [Table 3]

[0437] <Method for producing light-emitting device 2> The light-emitting device 2 described in this example was fabricated using a method having the following steps.

[0438] The method for fabricating light-emitting device 2 differs from the method for fabricating light-emitting device 1 in the steps of forming layers 113A, 113B, and 105. Here, the differences will be described in detail, and the above description will be used for the parts where similar methods are used.

[0439] [Eighth Step] In the eighth step, a layer 113A was formed on the layer 111. Specifically, the material was evaporated by using a resistance heating method.

[0440] The layer 113A contains mmtBumBP-dmmtBuPTzn and has a thickness of 10 nm.

[0441] [9th step] In the ninth step, the layer 113B was formed on the layer 113A by co-evaporation of materials using a resistance heating method.

[0442] The layer 113B contains mmtBumBP-dmmtBuPTzn and 6-methyl-8-quinolinolato-lithium (abbreviation: Li-6mq) in a weight ratio of mmtBumBP-dmmtBuPTzn:Li-6mq=0.5:0.5, and has a thickness of 20 nm.

[0443] [Step 10] In the tenth step, the layer 105 was formed on the layer 113B by depositing the material using a resistive heating method.

[0444] The layer 105 contains Li-6mq and has a thickness of 1 nm.

[0445] <<Operation characteristics of light-emitting device 2>> When power was supplied, the light emitting device 2 emitted light EL1 (see FIG. 16). The operating characteristics of the light emitting device 2 were measured (see FIGS. 19 to 24). The measurements were carried out at room temperature.

[0446] Light-emitting device 2 is set at a brightness of 1000 cd / m 2 Table 2 shows the main initial characteristics when light is emitted at about this temperature.

[0447] Light-emitting device 1 and light-emitting device 2 according to an embodiment of the present invention exhibited higher current efficiency and blue index than comparative light-emitting device 1. Therefore, an embodiment of the present invention is suitable for use as a light-emitting device in a display.

[0448] (Reference example 1) The structure of comparative light-emitting device 1 is shown in Table 4. 2-[3'-(9,9-dimethyl-9H-fluoren-2-yl)biphenyl-3-yl]-4,6-diphenyl-1,3,5-triazine (abbreviation: mFBPTzn) was used as the electron transport material. The wavelength-refractive index characteristics of mFBPTzn are shown in Figure 18. The refractive index of mFBPTzn ranges from 1.79 to 1.81 in the wavelength range of 440 nm to 470 nm.

[0449] The comparative light-emitting device 1 fabricated in this example differs from the light-emitting device 1 in the thickness of the layer 112A and in the structure in which the layer 113A contains 2-[3'-(9,9-dimethyl-9H-fluoren-2-yl)biphenyl-3-yl]-4,6-diphenyl-1,3,5-triazine (abbreviation: mFBPTzn) and the layer 113B contains 2-[3-(2,6-dimethyl-3-pyridinyl)-5-(9-phenanthrenyl)phenyl]-4,6-diphenyl-1,3,5-triazine (abbreviation: mPn-mDMePyPTzn).

[0450] [Table 4]

[0451] <<Method for fabricating comparative light-emitting device 1>> Comparative Light-Emitting Device 1 was fabricated using a method having the following steps.

[0452] The method for fabricating comparative light-emitting device 1 differs from the method for fabricating light-emitting device 1 in the steps of forming layer 112A, forming layer 113A, and forming layer 113B. Here, the differences will be described in detail, and the above description will be used for the parts where similar methods are used.

[0453] [Fourth step] In the fourth step, a layer 112A was formed on the layer 104. Specifically, the material was evaporated using a resistive heating method.

[0454] Note that layer 112A includes PCBBiF and has a thickness of 15 nm.

[0455] [Eighth Step] In the eighth step, a layer 113A was formed on the layer 111. Specifically, the material was evaporated by using a resistance heating method.

[0456] The layer 113A includes mFBPTzn and has a thickness of 10 nm.

[0457] [9th step] In the ninth step, the layer 113B was formed on the layer 113A by co-evaporation of materials using a resistance heating method.

[0458] The layer 113B contains mPn-mDMePyPTzn and Liq in a weight ratio of mPn-mDMePyPTzn:Liq=1:1, and has a thickness of 20 nm.

[0459] <<Operating characteristics of comparative light-emitting device 1>> When power was applied, the comparative light-emitting device 1 emitted light EL1 (see FIG. 16). The operating characteristics of the comparative light-emitting device 1 were measured (see FIGS. 19 to 24). The measurements were carried out at room temperature.

[0460] Comparison light-emitting device 1 with a brightness of 1000 cd / m 2 Table 2 shows the main initial characteristics when light is emitted at about this temperature. [Example]

[0461] In this example, a structure of a light-emitting device 3 according to one embodiment of the present invention will be described with reference to FIGS.

[0462] FIG. 25 is a diagram illustrating the configuration of a light-emitting device.

[0463] FIG. 26 is a diagram illustrating the emission spectrum of the luminescent material according to the example.

[0464] <Light-emitting device 3> The light-emitting device 3 fabricated in this example has the same configuration as the light-emitting device 150 (see FIG. 25).

[0465] Light-emitting device 150 has electrode 101, electrode 102, and unit 103. Electrode 102 has an area overlapping with electrode 101, and unit 103 has an area sandwiched between electrode 101 and electrode 102. Unit 103 has layers 111, 112, and 113.

[0466] Layer 111 has a region sandwiched between electrode 101 and electrode 102, and layer 111 contains a light-emitting material. The light-emitting material emits photoluminescent light, and the photoluminescent light has a spectrum. The spectrum has a maximum peak at wavelength λ1, which is in the range of 440 nm to 470 nm. Specifically, the emission spectrum of the light-emitting material in solution has a maximum peak at 450 nm, and the full width at half maximum (FWHM) of the emission spectrum is 30 nm (see FIG. 26). The full width at half maximum (FWHM) is in the range of 10 nm to 35 nm.

[0467] Layer 112 comprises the area sandwiched between electrode 101 and layer 111 .

[0468] Layer 113 has a region sandwiched between layer 111 and electrode 102, and layer 113 contains an organic compound ETM. The organic compound ETM has a first refractive index n1 for light having a wavelength λ1, and the first refractive index n1 is 1.4 or more and 1.75 or less. Specifically, mmtBumBPTzn was used as the organic compound ETM. The wavelength-refractive index characteristics of mmtBumBPTzn are shown in Figure 18. The refractive index of mmtBumBPTzn is in the range of 1.67 to 1.68 in the wavelength range of 440 nm to 470 nm, and is 1.4 or more and 1.75 or less.

[0469] <<Configuration of Light-Emitting Device 3>> The configuration of light-emitting device 3 is shown in Table 5. The structural formulas of the materials used in the light-emitting device described in this example are shown above.

[0470] [Table 5]

[0471] <Simulation of the operating characteristics of light-emitting device 3> The operating characteristics of the light-emitting device 3 were simulated. The software used for the calculation was an organic device simulator (Cybernet Systems Co., Ltd., product name: semiconducting emissive thin film optics simulator: setfos).

[0472] As a result of the simulation, the blue index of the light-emitting device 3 was 480.2 (cd / A / y), which was 1.19 times that of the comparative light-emitting device 2 described below.

[0473] (Reference example 2) The configuration of the comparative light-emitting device 2 differs from that of the light-emitting device 3 in the configuration of the layer 111. Specifically, the layer 111 contains a different light-emitting material from that of the light-emitting device 3. The maximum peak of the emission spectrum of the light-emitting material in solution is at 450 nm, and the full width at half maximum (FWHM) of the emission spectrum is 40 nm (see FIG. 26). The full width at half maximum (FWHM) is outside the range of 10 nm to 35 nm.

[0474] <Simulation of the operating characteristics of comparative light-emitting device 2> The operating characteristics of the comparative light-emitting device 2 were simulated. As a result of the same simulation as for the light-emitting device 3, the blue index of the comparative light-emitting device 2 was found to be 404.3. [Example]

[0475] FIG. 27 is a diagram illustrating the wavelength-refractive index characteristics of the organic compound ETM according to the example and the wavelength-reflectance characteristics of silver in contact with the organic compound ETM.

[0476] The reflectance R(1) of silver in contact with layer n(1), which has a refractive index of 1.5, and the reflectance R(2) of silver in contact with layer n(2), which has a refractive index of 1.9, were simulated using software. The software used for the calculations was the Organic Device Simulator (Cybernet Systems Co., Ltd., product name: semiconducting emissive thin film optics simulator: SETFOS).

[0477] Calculation results showed that the reflectance of silver in contact with a layer with a refractive index of 1.5 was higher than that of silver in contact with a layer with a refractive index of 1.9 (see Figure 27).

[0478] (Reference synthesis example 1) An example of a method for synthesizing the low refractive index electron transport material used in the organic compound ETM in the examples is shown below.

[0479] First, we will explain the synthesis method of 2-{(3',5'-di-tert-butyl)-1,1'-biphenyl-3-yl}-4,6-bis(3,5-di-tert-butylphenyl)-1,3,5-triazine (abbreviation: mmtBumBP-dmmtBuPTzn), an organic compound represented by structural formula (200). The structure of mmtBumBP-dmmtBuPTzn is shown below.

[0480] [ka]

[0481] <Step 1: Synthesis of 3-bromo-3',5'-di-tert-butylbiphenyl> A three-neck flask was charged with 1.0 g (4.3 mmol) of 3,5-di-t-butylphenylboronic acid, 1.5 g (5.2 mmol) of 1-bromo-3-iodobenzene, 4.5 mL of 2 mol / L aqueous potassium carbonate, 20 mL of toluene, and 3 mL of ethanol. The mixture was degassed by stirring under reduced pressure. 52 mg (0.17 mmol) of tris(2-methylphenyl)phosphine and 10 mg (0.043 mmol) of palladium(II) acetate were added and reacted at 80 °C for 14 hours under a nitrogen atmosphere. After the reaction was completed, the mixture was extracted with toluene, and the resulting organic layer was dried over magnesium sulfate. The mixture was gravity filtered, and the filtrate was purified by silica gel column chromatography (eluent: hexane) to obtain 1.0 g of the desired white solid (yield: 68%). The synthesis scheme for Step 1 is shown below.

[0482] [ka]

[0483] <Step 2: Synthesis of 2-(3',5'-di-tert-butylbiphenyl-3-yl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane> A three-neck flask was charged with 1.0 g (2.9 mmol) of 3-bromo-3',5'-di-tert-butylbiphenyl, 0.96 g (3.8 mmol) of bis(pinacolato)diboron, 0.94 g (9.6 mmol) of potassium acetate, and 30 mL of 1,4-dioxane. The mixture was degassed by stirring under reduced pressure. 0.12 g (0.30 mmol) of 2-dicyclohexylphosphino-2',6'-dimethoxybiphenyl and 0.12 g (0.15 mmol) of [1,1'-bis(diphenylphosphino)ferrocene]palladium(II) dichloride dichloromethane adduct were then added and reacted under a nitrogen atmosphere at 110°C for 24 hours. After the reaction was complete, the mixture was extracted with toluene, and the resulting organic layer was dried over magnesium sulfate. The mixture was gravity filtered. The obtained filtrate was purified by silica gel column chromatography (developing solvent: toluene) to obtain 0.89 g of the target yellow oil (yield: 78%). The synthesis scheme of Step 2 is shown below.

[0484] [ka]

[0485] <Step 3: Synthesis of mmtBumBP-dmmtBuPTzn> A three-neck flask was charged with 0.8 g (1.6 mmol) of 4,6-bis(3,5-di-tert-butylphenyl)-2-chloro-1,3,5-triazine, 0.89 g (2.3 mmol) of 2-(3',5'-di-tert-butylbiphenyl-3-yl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane, 0.68 g (3.2 mmol) of tripotassium phosphate, 3 mL of water, 8 mL of toluene, and 3 mL of 1,4-dioxane. The mixture was degassed by stirring under reduced pressure. 3.5 mg (0.016 mmol) of palladium(II) acetate and 10 mg (0.032 mmol) of tris(2-methylphenyl)phosphine were added and heated to reflux under a nitrogen atmosphere for 12 hours. After completion of the reaction, the mixture was extracted with ethyl acetate, and the resulting organic layer was dried over magnesium sulfate. The mixture was gravity filtered. The resulting filtrate was concentrated and purified by silica gel column chromatography (eluent: ethyl acetate:hexane = 1:20) to obtain a solid. This solid was purified by silica gel column chromatography (eluent: chloroform:hexane = 5:1 changed to 1:0). The resulting solid was recrystallized with hexane to obtain 0.88 g (yield: 76%) of the desired white solid. The synthesis scheme for Step 3 is shown below.

[0486] [ka]

[0487] 0.87 g of the obtained white solid was purified by train sublimation at 230° C. under a pressure of 5.8 Pa and a flow of argon gas. After sublimation purification, 0.82 g of the target white solid was obtained with a recovery rate of 95%.

[0488] The white solid obtained in step 3 was analyzed by nuclear magnetic resonance spectroscopy ( 1 The results of the analysis by H-NMR are shown below. From these results, it was found that mmtBumBP-dmmtBuPTzn represented by the above structural formula (200) was obtained by the above synthesis method.

[0489] 1H NMR (CDCl3, 300MHz): δ=1.42-1.49(m,54H),7.50(s,1H),7.61-7.70(m,5H),7.87(d,1H),8.68-8.69(m,4H),8.78(d,1H),9.06(s,1H).

[0490] (Reference synthesis example 2) Similarly, an organic compound represented by the following structural formula (201), 2-{(3',5'-di-tert-butyl)-1,1'-biphenyl-3-yl}-4,6-diphenyl-1,3,5-triazine (abbreviation: mmtBumBPTzn), was synthesized.

[0491] [ka]

[0492] The above organic compounds were analyzed by nuclear magnetic resonance spectroscopy ( 1 The results of analysis by H-NMR are shown below.

[0493] 1 H NMR (CDCl3, 300MHz): δ = 1.44 (s, 18H), 7.51-7.68 (m, 10H), 7.83 (d, 1H), 8.73-8.81 (m, 5H), 9.01 (s, 1H).

[0494] All of the above organic compounds have an ordinary refractive index of 1.50 or more and 1.75 or less in the blue light emission region (455 nm or more and 465 nm or less), or an ordinary refractive index of 1.45 or more and 1.70 or less in the 633 nm light wavelength that is typically used to measure refractive index.

[0495] (Reference synthesis example 3) The synthesis method of 6-methyl-8-quinolinolato-lithium (abbreviation: Li-6mq) used in the examples will be described below. The structural formula of Li-6mq is shown below.

[0496] [ka]

[0497] 2.0 g (12.6 mmol) of 8-hydroxy-6-methylquinoline and 130 mL of dehydrated tetrahydrofuran (THF) were placed in a three-neck flask and stirred. 10.1 mL (10.1 mmol) of a 1 M THF solution of lithium tert-butoxide (tBuOLi) was added to this solution and stirred at room temperature for 47 hours. The reaction solution was concentrated to obtain a yellow solid. Acetonitrile was added to this solid, and the mixture was subjected to ultrasonic irradiation and filtration to obtain a pale yellow solid. This washing procedure was repeated twice. 1.6 g (95% yield) of a pale yellow solid of Li-6mq was obtained as the filtrate. The synthesis scheme is shown below.

[0498] [ka] [Explanation of symbols]

[0499] CAP layer 101 Electrode 101S electrode 102 electrode 103 units 103S unit 104 layers 105 layers 106 layers 106A layer 106B layer 111 layers 112 layers 112A layer 112B layer 112C layer 113 layers 113A layer 113B layer 114 layers 114N layer 114P layer 150 Light-emitting devices 400 boards 401 Electrode 403 EL layer 404 Electrode 405 Sealing material 406 Sealing material 407 Sealing substrate 412 Pad 420 IC chip 513 Charge generation layer 601 Source line driver circuit 602 Pixel section 603 Gate line driving circuit 604 Sealing substrate 605 Sealing material 607 Space 608 Wiring 610 PCB 611 Switching FET 612 Current control FET 613 Electrode 614 Insulators 616 EL layer 617 Electrode 618 Light-emitting devices 623 FET 700 Function Panel 951 PCB 952 Electrode 953 Insulation Layer 954 Partition layer 955 EL layer 956 Electrode 1001 board 1002 Undercoat 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 Bulkhead 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 section 1041 Drive circuit section 1042 Periphery 2001 Case 2002 light source 2100 Robot 2101 Illuminance sensor 2102 Microphone 2103 Upper Camera 2104 Speaker 2105 Display 2106 Lower Camera 2107 Obstacle Sensor 2108 Moving mechanism 2110 Arithmetic equipment 3001 Lighting equipment 5000 cabinets 5001 Display section 5002 Display section 5003 Speaker 5004 LED lamp 5006 Connection terminal 5007 Sensor 5008 Microphone 5012 Support part 5013 Earphones 5100 Cleaning Robot 5101 Display 5102 Camera 5103 Brush 5104 Operation button 5120 Garbage 5140 Portable electronic devices 5200 display area 5201 Display area 5202 Display area 5203 Display area 7101 Housing 7103 Display section 7105 Stand 7107 Display section 7109 Operation key 7110 Remote control device 7201 Main unit 7202 Case 7203 Display section 7204 keyboard 7205 External connection port 7206 Pointing Device 7210 Display section 7401 Housing 7402 Display section 7403 Operation button 7404 External connection port 7405 Speaker 7406 Microphone 9310 Mobile Information Terminal 9311 Display Panel 9313 Hinge 9315 Housing

Claims

1. a first electrode, a second electrode, a first layer, and a second layer; the second electrode has an area overlapping with the first electrode; the first layer comprises a region sandwiched between the first electrode and the second electrode; the first layer includes a light-emitting material; the luminescent material has a function of emitting photoluminescence light in a solution, the photoluminescent light has a first spectrum φ1; the first spectrum φ1 has a maximum peak at a wavelength λ1; The wavelength λ1 is in the range of 440 nm or more and 470 nm or less, the second layer comprises a region sandwiched between the first layer and the second electrode; the second layer includes a first organic compound; the first organic compound has a first refractive index n1 with respect to light having the wavelength λ1; the first refractive index n1 is equal to or greater than 1.4 and equal to or less than 1.75, a light-emitting device, wherein the first organic compound is an organic compound having at least one six-membered heteroaromatic ring containing one to three nitrogen atoms, a plurality of aromatic hydrocarbon rings each having 6 to 14 carbon atoms forming the ring, at least two of the aromatic hydrocarbon rings being benzene rings, and a plurality of hydrocarbon groups forming bonds via sp3 hybrid orbitals.

2. In claim 1, A light-emitting device, wherein the ratio of the number of carbon atoms forming bonds via sp3 hybrid orbitals to the total number of carbon atoms in the molecule of the first organic compound is 10% or more and 60% or less.

3. A semiconductor device comprising a first electrode, a second electrode, a first layer, and a second layer, the second electrode has an area overlapping with the first electrode; the first layer comprises a region sandwiched between the first electrode and the second electrode; the first layer includes a light-emitting material; the luminescent material has a function of emitting photoluminescence light in a solution, the photoluminescent light has a first spectrum φ1; the first spectrum φ1 has a maximum peak at a wavelength λ1; The wavelength λ1 is in the range of 440 nm or more and 470 nm or less, the second layer comprises a region sandwiched between the first layer and the second electrode; the second layer includes a first organic compound; the first organic compound has a first refractive index n1 with respect to light having the wavelength λ1; the first refractive index n1 is equal to or greater than 1.4 and equal to or less than 1.75, The first organic compound is represented by the following general formula (G ｅ１ 2) A light-emitting device. 【Chemistry 1】 (Q １ ~Q ３ two or three of which are nitrogen atoms, Q １ ~Q ３ When two of the groups are nitrogen atoms, one represents CH; R ２０１ ~R ２１５ at least one of is a phenyl group having a substituent; R ２０１ ~R ２１５ each independently represents a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, an alicyclic hydrocarbon group having 3 to 10 carbon atoms, a substituted or unsubstituted ring-forming aromatic hydrocarbon group having 6 to 14 carbon atoms, or a substituted or unsubstituted pyridyl group; The substituted phenyl group has one or two substituents, The substituents are each independently an alkyl group having 1 to 6 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 forming a ring.

4. In claim 3, the first organic compound contains sp3 carbon; The sp3 carbon forms a bond with another atom through an sp3 hybrid orbital, A light-emitting device, wherein the sp3 carbon occupies 10% to 60% of all carbon contained in the first organic compound.

5. In any one of claims 1 to 4, A light-emitting device, wherein the full width at half maximum FWHM of the first spectrum φ1 is 10 nm or more and 35 nm or less.

6. In any one of claims 1 to 5, The light-emitting device, wherein the second electrode comprises silver.

7. A light emitting apparatus comprising the light emitting device according to claim 1 and at least one of a transistor and a substrate.

8. A display device comprising the light-emitting device according to claim 1 and at least one of a transistor and a substrate.

9. A lighting device comprising the light-emitting device according to claim 7 and a housing.

10. 9. An electronic device comprising the display device according to claim 8 and at least one of a sensor, an operation button, a speaker, and a microphone.

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