organic electroluminescence element

Abstract

Provided is an organic electroluminescent element by which high light-emission efficiency can be obtained even in a case in which the LUMO level of a fluorescent material is lower than the LUMO level of a delayed fluorescent material. The organic electroluminescent element contains, in a light-emitting layer, a first organic compound, a second organic compound that is a delayed fluorescent material, and a third organic compound that emits fluorescent light. The LUMO energy of the second organic compound is higher than that of the third organic compound. The largest component of emitted light from the element is fluorescent light from the third organic compound, and the orientation value of the third organic compound in the light-emitting layer is -0.3 or less.

Description

[Technical Field]

[0001] The present invention relates to an organic electroluminescent device with high luminous efficiency. [Background technology]

[0002] Research into improving the luminous efficiency of organic electroluminescent devices (organic EL devices) has been actively pursued. In particular, various efforts have been made to develop new material compositions for the luminescent layer of organic electroluminescent devices, which convert the energy of the excited triplet state, which is non-radiatively deactivated at room temperature, into excited singlet energy and use it for luminescence. For example, Patent Document 1 proposes a three-component organic electroluminescence device in which an emitting layer is composed of a host material, a delayed fluorescent material, and a fluorescent material. In this emitting layer, the excited triplet energy transferred from the host material to the delayed fluorescent material and the excited triplet energy generated in the delayed fluorescent material are converted into excited singlet energy by reverse intersystem crossing from triplet to singlet in the delayed fluorescent material, and then transferred to the fluorescent material and emitted as fluorescence. As a result, it is said that the excited triplet energy generated in the emitting layer is effectively used to emit light from the fluorescent material, thereby achieving high luminous efficiency. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2015-179809 Summary of the Invention [Problem to be solved by the invention]

[0004] The emission wavelength of a fluorescent material depends on the HOMO-LUMO energy gap and the Stokes shift, and various fluorescent materials with different energy values ​​have been developed. Therefore, in the above-mentioned three-component emitting layer, depending on the fluorescent material used, the LUMO energy of the fluorescent material may be higher or lower (deeper) than the LUMO energy of the delayed fluorescent material. Under these circumstances, the present inventors constructed an emitting layer by combining various delayed fluorescent materials and fluorescent materials with a host material. They found that when the LUMO energy of the fluorescent material is lower than the LUMO energy of the delayed fluorescent material, increasing the concentration of the fluorescent material reduces the luminous efficiency, and thus the luminous efficiency cannot be sufficiently improved.

[0005] Therefore, the present inventors have conducted extensive research with the aim of providing an organic electroluminescence element that includes a host material, a delayed fluorescent material, and a fluorescent material in an emission layer, and that can achieve high luminous efficiency even when the LUMO energy of the fluorescent material is lower than the LUMO energy of the delayed fluorescent material. [Means for solving the problem]

[0006] As a result of extensive investigations, the present inventors have found that even when the LUMO energy of a fluorescent material is lower than the LUMO energy of a delayed fluorescent material, the luminous efficiency can be improved even if the concentration of the fluorescent material is increased, as long as the orientation value S of the organic compound molecules used as the fluorescent material is −0.3 or less. The present invention has been proposed based on these findings, and specifically has the following configuration.

[0007] [1] An organic electroluminescence element having an anode, a cathode, and at least one organic layer including a light-emitting layer between the anode and the cathode, the light-emitting layer contains a first organic compound, a second organic compound, and a third organic compound, and satisfies the following formula (a) and formula (b): the second organic compound is a delayed fluorescent material, An organic electroluminescence device, wherein the largest component of light emitted from the device is fluorescence from the third organic compound.

number

[10] The organic electroluminescence device according to any one of [7] to [9], wherein three or more of the donor groups are bonded to the benzene ring.

[11] The organic electroluminescence device according to any one of [1] to

[10] , wherein the first organic compound, the second organic compound, and the third organic compound satisfy the following (a1): E LUMO (1)> E LUMO (2)> E LUMO (3) Formula (a1) [where: E LUMO (1) is the LUMO energy of the first organic compound E LUMO (2) is the LUMO energy of the second organic compound ELUMO (3) is the LUMO energy of the third organic compound S represents the orientation value of the third organic compound in the light-emitting layer.] [Effects of the Invention]

[0008] According to the present invention, in an organic electroluminescence element including a first organic compound, a second organic compound that is a delayed fluorescent material, and a third organic compound that emits fluorescence in an emission layer, even if the LUMO energy of the third organic compound is lower than the LUMO energy of the second organic compound, the luminous efficiency can be improved by increasing the concentration of the third organic compound. DETAILED DESCRIPTION OF THE INVENTION

[0009] The present invention will be described in detail below. The following description of the constituent elements may be based on typical embodiments and specific examples of the present invention, but the present invention is not limited to such embodiments and specific examples. In this application, a numerical range expressed using "to" means a range that includes the numerical values ​​before and after "to" as the lower and upper limits. In addition, in this application, "consisting of" means that the compound consists only of what is described before "consisting of" and does not include anything else. In addition, some or all of the hydrogen atoms present in the molecules of the compound used in the present invention may be replaced by deuterium atoms ( 2In the chemical structural formulas herein, hydrogen atoms are represented by H or omitted. For example, when the atom bonded to a carbon atom constituting the ring skeleton of a benzene ring is omitted, H is assumed to be bonded to the carbon atom constituting the ring skeleton at the omitted position. In this specification, the term "substituent" refers to an atom or group of atoms other than hydrogen atoms and deuterium atoms. On the other hand, the expressions "substituted or unsubstituted" and "optionally substituted" mean that a hydrogen atom may be substituted with a deuterium atom or a substituent. In addition, "transparent" in the present invention refers to a visible light transmittance of 50% or more, preferably 80% or more, more preferably 90% or more, and even more preferably 99% or more. Visible light transmittance can be measured using an ultraviolet-visible spectrophotometer.

[0010] The organic electroluminescent device of the present invention is an organic electroluminescent device having an anode, a cathode, and at least one organic layer including an emitting layer between the anode and the cathode. The organic layer may be composed of only the emitting layer, or may include an organic layer other than the emitting layer. For example, an organic layer may or may not be interposed between the anode and the emitting layer, and between the emitting layer and the cathode. In other words, the anode and the emitting layer may be laminated so as to be in direct contact with each other, or may not be in direct contact with each other. Furthermore, the emitting layer and the cathode may be laminated so as to be in direct contact with each other, or may not be in direct contact with each other. The emitting layer is preferably located between the anode and the cathode, and the entire emitting layer is preferably disposed without extending into the region between the anode and the cathode. The organic electroluminescent device of the present invention may have a substrate supporting an anode, a cathode, and at least one organic layer including an emitting layer. In this case, the substrate may be disposed on the opposite side of the anode from the emitting layer, or on the opposite side of the cathode from the emitting layer. The organic electroluminescent device of the present invention may be a top-emission device in which most of the light is emitted from the side opposite the substrate, or a bottom-emission device in which most of the light is emitted from the substrate side. Here, "most of the light" means light that accounts for 60% or more of the amount of light emitted from the device.

[0011] The organic electroluminescent device of the present invention includes a first organic compound, a second organic compound, and a third organic compound in an emitting layer. Here, the second organic compound is a delayed fluorescent material. The third organic compound is a compound that emits fluorescence. In the organic electroluminescent device of the present invention, the largest component of light emitted from the device is fluorescence from the third organic compound.

[0012] The second organic compound and the third organic compound contained in the light-emitting layer satisfy the following formulas (a) and (b). E LUMO (2)> E LUMO (3) Formula (a) S ≦-0.3 Equation (b) In one embodiment of the present invention, the first organic compound, the second organic compound, and the third organic compound contained in the light-emitting layer satisfy the following formula (a1) and formula (b). E LUMO (1)> E LUMO (2)> E LUMO (3) Formula (a1) S ≦-0.3 Equation (b)

[0013] E in formula (a) and formula (a1) LUMO (1) represents the LUMO energy of the first organic compound, and E LUMO (2) represents the LUMO energy of the second organic compound, and E LUMO(3) represents the LUMO energy of the third organic compound. LUMO is an abbreviation for Lowest Unoccupied Molecular Orbital, and can be determined by atmospheric photoelectron spectroscopy (such as with an AC-3 manufactured by Riken Keiki Co., Ltd.). Since the present invention satisfies the relationship of formula (a), the LUMO energy of the second organic compound contained in the light-emitting layer is higher than the LUMO energy of the third organic compound. When the relationship of formula (a1) is satisfied, among the first, second, and third organic compounds contained in the light-emitting layer, the LUMO energy of the first organic compound is the highest, the second organic compound is the next highest, and the third organic compound is the lowest. The LUMO energy difference [E LUMO (1)-E LUMO (2)] can be, for example, 0.1 eV or more, 0.5 eV or more, 0.8 eV or more, or 1.0 eV or more, or 2.0 eV or less, 1.5 eV or less, 1.3 eV or less, or 1.1 eV or less. LUMO (2)-E LUMO (3)] ​​can be, for example, 0.01 eV or more, 0.05 eV or more, 0.1 eV or more, 0.15 eV or more, or 0.2 eV or more, or 0.7 eV or less, 0.5 eV or less, 0.4 eV or less, or 0.3 eV or less. In one embodiment of the present invention, a compound having a LUMO energy in the range of -2.0 to -5.0 eV or -2.5 to -4.0 eV can be used as the first organic compound. In another embodiment of the present invention, a compound having a LUMO energy in the range of -2.0 to -5.0 eV or -2.5 to -4.0 eV can be used as the second organic compound. In one embodiment of the present invention, a compound having a LUMO energy in the range of −2.0 to −5.0 eV or −2.5 to −4.0 eV can be used as the third organic compound.

[0014] The relationship between the HOMO energies of the first organic compound, the second organic compound, and the third organic compound is not particularly limited. For example, the HOMO energy of the second organic compound may be smaller or larger than that of the first organic compound, or may be the same as that of the first organic compound. The HOMO energy of the third organic compound may be smaller or larger than that of the second organic compound, or may be the same as that of the second organic compound. HOMO is an abbreviation for Highest Occupied Molecular Orbital and can be determined by atmospheric photoelectron spectroscopy (e.g., AC-3, manufactured by Riken Keiki Co., Ltd.). In one embodiment of the present invention, a compound having a HOMO energy in the range of -4.0 to -6.5 eV or -5.5 to -6.2 eV can be used as the first organic compound. In another embodiment of the present invention, a compound having a HOMO energy in the range of -4.0 to -6.5 eV or -5.5 to -6.2 eV can be used as the second organic compound. In one embodiment of the present invention, a compound having a HOMO energy in the range of −4.0 to −6.5 eV or a compound having a HOMO energy in the range of −5.0 to −6.0 eV can be used as the third organic compound.

[0015] In formula (b), S represents the orientation value of the third organic compound in the light-emitting layer. Since the present invention satisfies formula (b), the orientation value of the third organic compound in the light-emitting layer is -0.3 or less. The orientation value is also called the S value, and is an index showing the degree of orientation of the third organic compound in the light-emitting layer. The larger the negative value (the smaller the numerical value), the higher the orientation. The orientation value (S value) is calculated as follows: The orientation value of the third organic compound can be determined by the method described in J. Appl. Pub. No. 7, 8405. In the organic electroluminescent device of the present invention, the orientation value of the third organic compound is -0.3 or less, thereby achieving a high external quantum yield while satisfying the LUMO energy relationship of formula (a). That is, in conventional organic electroluminescent devices that do not take the orientation value of the fluorescent material into consideration, when the LUMO energy of the fluorescent material is lower than that of the delayed fluorescent material, increasing the concentration of the fluorescent material leads to a problem of reduced luminous efficiency. In contrast, in the organic electroluminescent device of the present invention, the LUMO energy of the third organic compound that emits fluorescence is set lower than the LUMO energy of the second organic compound, which is a delayed fluorescent material. However, by specifying the orientation value of the third organic compound in the emissive layer to -0.3 or less, the luminous efficiency can be improved while increasing the concentration of the third organic compound. Furthermore, a third organic compound with an orientation value of -0.3 or less is highly stable, and using it as an emissive material also has the effect of improving the device's lifespan. The alignment value of the third organic compound in the light-emitting layer is preferably −0.38 or less, more preferably −0.40 or less, even more preferably −0.41 or less, and even more preferably −0.42 or less.

[0016] The first organic compound, the second organic compound, and the third organic compound contained in the light-emitting layer preferably satisfy the following formula (c). E S1 (1)> E S1 (2)> E S1 (3) Formula (c)

[0017] E in formula (c) S1 (1) represents the lowest excited singlet energy of the first organic compound, and E S1 (2) represents the lowest excited singlet energy of the second organic compound, and E S1 (3) represents the lowest excited singlet energy of the third organic compound. In this specification, the unit is eV. The lowest excited singlet energy is measured by measuring the concentration of the compound in a thin film or a toluene solution (concentration 10 -5mol / L) and measure the fluorescence spectrum at room temperature (300 K) (for details, see the method for measuring the lowest excited singlet energy in the explanation of the second organic compound).

[0018] As shown in formula (c), among the first organic compound, the second organic compound, and the third organic compound contained in the light-emitting layer, it is preferable that the minimum excited singlet energy of the first organic compound is the highest, that of the second organic compound is the next highest, and that of the third organic compound is the lowest. S1 (1)-E S1 (2) can be, for example, in the range of 0.20 eV or more, 0.40 eV or more, or 0.60 eV or more, or in the range of 1.50 eV or less, 1.20 eV or less, or 0.80 eV or less. S1 (2)-E S1 (3) can be, for example, in the range of 0.05 eV or more, 0.10 eV or more, or 0.15 eV or more, or in the range of 0.50 eV or less, 0.30 eV or less, or 0.20 eV or less. S1 (1)-E S1 (3) can be, for example, in the range of 0.25 eV or more, 0.45 eV or more, or 0.65 eV or more, or in the range of 2.00 eV or less, 1.70 eV or less, or 1.30 eV or less.

[0019] In the organic electroluminescent device of the present invention, the largest component of light emitted from the device is fluorescence from the third organic compound. In the present invention, "light emitted from the device" refers to light emitted from the device when the device is operated at 20°C. Light emitted from the organic electroluminescent device of the present invention may include phosphorescence from the third organic compound and light emitted from the first and second organic compounds, as long as the largest component of light emitted from the device is fluorescence from the third organic compound. However, it is preferable that these lights are small compared to the fluorescence from the third organic compound. In the present invention, 70% or more of the light emitted from the device may be fluorescence from the third organic compound, 90% or more may be fluorescence from the third organic compound, or 99% or more may be fluorescence from the third organic compound.

[0020] The concentration of the third organic compound in the light-emitting layer of the organic electroluminescent device of the present invention is preferably greater than 0.3 wt %. The concentration of the third organic compound in the light-emitting layer can be in the range of 0.35 wt % or more, 0.5 wt % or more, 1 wt % or more, or 2 wt % or more. The concentration of the third organic compound in the light-emitting layer can be in the range of 10 wt % or less, 5 wt % or less, or 3 wt % or less. Furthermore, when the concentrations of the first organic compound, the second organic compound, and the third organic compound in the light-emitting layer of the organic electroluminescent element of the present invention are Conc(1), Conc(2), and Conc(3), respectively, it is preferable that the relationship of the following formula (d) be satisfied: Conc(1)>Conc(2)>Conc(3) Formula (d) Conc(1) is preferably 30% by weight or more, and can be in the range of 50% by weight or more, or 60% by weight or more, or can be in the range of 99% by weight or less, or 85% by weight or less, or 70% by weight or less. Conc(2) is preferably 5% by weight or more, and can be in the range of 15% by weight or more, 25% by weight or more, or 30% by weight or more, or in the range of 45% by weight or less, 40% by weight or less, or 35% by weight or less. In a preferred embodiment of the present invention, Conc(2) is 25 to 45% by weight. For the preferred range of Conc(3), the above description of the concentration of the third organic compound in the light-emitting layer can be referred to. Conc(1) / Conc(3) can be in the range of 10 or more, 50 or more, or 90 or more, and can be in the range of 10,000 or less, 1,000 or less, or 200 or less. Conc(2) / Conc(3) can be in the range of 10 or more, 50 or more, or 90 or more, and can be in the range of 10,000 or less, 1,000 or less, or 200 or less.

[0021] The light-emitting layer of the organic electroluminescent device of the present invention preferably does not contain any metal elements other than boron. Alternatively, a light-emitting layer that does not contain any metal elements containing boron can be used. For example, the light-emitting layer can be composed solely of compounds consisting of atoms selected from the group consisting of carbon, hydrogen, nitrogen, oxygen, sulfur, fluorine, and boron. For example, the light-emitting layer can be composed solely of compounds consisting of atoms selected from the group consisting of carbon, hydrogen, nitrogen, oxygen, sulfur, fluorine, and boron. For example, the light-emitting layer can be composed solely of compounds consisting of atoms selected from the group consisting of carbon, hydrogen, nitrogen, oxygen, and sulfur. For example, the light-emitting layer can be composed solely of compounds consisting of atoms selected from the group consisting of carbon, hydrogen, nitrogen, oxygen, and sulfur.

[0022] (first organic compound) The first organic compound used in the light-emitting layer of the organic electroluminescent device of the present invention is selected from compounds having a higher LUMO energy than the second and third organic compounds. The first organic compound is preferably selected from compounds having a higher LUMO energy than the second and third organic compounds and a lower singlet energy than the second and third organic compounds. The first organic compound preferably functions as a host material responsible for carrier transport. The first organic compound preferably also functions to trap the energy of the third organic compound within the compound. This allows the third organic compound to efficiently convert the energy generated by the recombination of holes and electrons within the molecule and the energy received from the first and second organic compounds into light emission. The first organic compound is preferably an organic compound that has hole transport ability and electron transport ability, prevents the emission wavelength from shifting to a longer wavelength, and has a high glass transition temperature. In a preferred embodiment of the present invention, the first organic compound is selected from compounds that do not emit delayed fluorescence. The emission from the first organic compound is preferably less than 1% of the emission from the organic electroluminescence device of the present invention, more preferably less than 0.1%, and may be, for example, less than 0.01%, or below the detection limit. The first organic compound preferably does not contain metal atoms. For example, the first organic compound may be a compound consisting of atoms selected from the group consisting of carbon atoms, hydrogen atoms, nitrogen atoms, oxygen atoms, and sulfur atoms. For example, the first organic compound may be a compound consisting of atoms selected from the group consisting of carbon atoms, hydrogen atoms, nitrogen atoms, and oxygen atoms. For example, the first organic compound may be a compound consisting of carbon atoms, hydrogen atoms, and nitrogen atoms. Preferred compounds that can be used as the first organic compound are listed below.

[0023] [ka] [ka] [ka] [ka]

[0024] (Second organic compound) The second organic compound used in the light-emitting layer of the organic electroluminescent device of the present invention is a delayed fluorescent material having a lower LUMO energy than the first organic compound and a higher LUMO energy than the third organic compound. The second organic compound is preferably a delayed fluorescent material having a lower LUMO energy than the first organic compound and a higher LUMO energy than the third organic compound, and having a minimum excited singlet energy that is lower than that of the first organic compound and higher than that of the third organic compound. The "delayed fluorescent material" of the present invention refers to an organic compound that, in an excited state, undergoes reverse intersystem crossing from an excited triplet state to an excited singlet state and emits fluorescence (delayed fluorescence) upon returning from the excited singlet state to the ground state. In the present invention, a delayed fluorescent material is one that emits fluorescence with an emission lifetime of 100 ns (nanoseconds) or longer when measured using a fluorescence lifetime measurement system (such as a streak camera system manufactured by Hamamatsu Photonics KK). The second organic compound is a material capable of emitting delayed fluorescence, but it is not essential that the second organic compound emits delayed fluorescence when used in the organic electroluminescence device of the present invention. The light emission from the second organic compound is preferably less than 10% of the light emission from the organic electroluminescence device of the present invention, and may be, for example, less than 1%, less than 0.1%, less than 0.01%, or below the detection limit. In the organic electroluminescence device of the present invention, the second organic compound receives energy from the first organic compound in an excited singlet state to transition to the excited singlet state. Alternatively, the second organic compound may receive energy from the first organic compound in an excited triplet state to transition to the excited triplet state. The second organic compound has a difference between the excited singlet energy and the excited triplet energy (ΔE ST) is small, the second organic compound in the excited triplet state is likely to undergo reverse intersystem crossing to the second organic compound in the excited singlet state. The second organic compound in the excited singlet state generated by these pathways provides energy to the third organic compound, causing it to transition to the excited singlet state.

[0025] The second organic compound has a difference ΔE between the lowest excited singlet energy and the lowest excited triplet energy at 77 K. ST is preferably 0.3 eV or less, more preferably 0.25 eV or less, more preferably 0.2 eV or less, more preferably 0.15 eV or less, even more preferably 0.1 eV or less, even more preferably 0.07 eV or less, even more preferably 0.05 eV or less, even more preferably 0.03 eV or less, and particularly preferably 0.01 eV or less. ΔE ST If the σ is small, the second organic compound easily undergoes reverse intersystem crossing from the excited singlet state to the excited triplet state upon absorption of thermal energy, and therefore functions as a thermally activated delayed fluorescent material. Thermally activated delayed fluorescent materials absorb heat emitted by the device and relatively easily undergo reverse intersystem crossing from the excited triplet state to the excited singlet state, allowing the excited triplet energy to efficiently contribute to light emission.

[0026] In the present invention, the lowest excited singlet energy (E S1 ) and the lowest excited triplet energy (E T1 ) is a value calculated by the following procedure. ST is E S1 -E T1 This is the value obtained by calculating (1) The lowest excited singlet energy (E S1 ) Thin film or toluene solution (concentration 10 -5A sample is prepared at a concentration of 1000 mol / L. The fluorescence spectrum of this sample is measured at room temperature (300K). The fluorescence spectrum has the emission on the vertical axis and the wavelength on the horizontal axis. A tangent line is drawn to the rising edge of the short wavelength side of this emission spectrum, and the wavelength value λedge [nm] at the intersection of this tangent line and the horizontal axis is found. This wavelength value is converted to an energy value using the following conversion formula and is called E. S1 Let's say. Conversion formula: E S1 [eV]=1239.85 / λedge In the examples described below, emission spectra were measured using an LED light source (M300L4, manufactured by Thorlabs) as the excitation light source and a detector (PMA-12 multichannel spectrometer C10027-01, manufactured by Hamamatsu Photonics KK). (2) The lowest excited triplet energy (E T1 ) The lowest excited singlet energy (E S1 The same sample used in the measurement of ) is cooled to 77[K] with liquid nitrogen, and the sample for phosphorescence measurement is irradiated with excitation light (300 nm), and the phosphorescence is measured using a detector. The emission from 100 milliseconds after irradiation with excitation light is taken as the phosphorescence spectrum. A tangent line is drawn to the rising edge of the short wavelength side of this phosphorescence spectrum, and the wavelength value λedge[nm] at the intersection of this tangent line and the horizontal axis is found. This wavelength value is converted to an energy value using the following conversion formula, and the value is called E T1 Let's say. Conversion formula: E T1 [eV]=1239.85 / λedge The tangent to the rising edge of the phosphorescence spectrum on the short wavelength side is drawn as follows: When moving along the spectral curve from the short wavelength side of the phosphorescence spectrum to the shortest maximum of the spectral maxima, consider the tangent at each point on the curve toward the long wavelength side. The slope of this tangent increases as the curve rises (i.e., as the vertical axis increases). The tangent drawn at the point where this slope is at its maximum is considered to be the tangent to the rising edge of the phosphorescence spectrum on the short wavelength side. Note that a maximum point having a peak intensity that is 10% or less of the maximum peak intensity of the spectrum is not included in the above-mentioned maximum value on the shortest wavelength side, and the tangent drawn at the point where the slope value is the maximum value that is closest to the maximum value on the shortest wavelength side is defined as the tangent to the rising edge on the short wavelength side of the phosphorescence spectrum.

[0027] The second organic compound preferably does not contain metal atoms. For example, the second organic compound may be a compound consisting of atoms selected from the group consisting of carbon atoms, hydrogen atoms, nitrogen atoms, oxygen atoms, and sulfur atoms. For example, the second organic compound may be a compound consisting of atoms selected from the group consisting of carbon atoms, hydrogen atoms, nitrogen atoms, and oxygen atoms. For example, the second organic compound may be a compound consisting of carbon atoms, hydrogen atoms, and nitrogen atoms.

[0028] Typical examples of the second organic compound include compounds having a structure in which one or two cyano groups and at least one donor group are bonded to a benzene ring. A preferred example of the donor group is a substituted or unsubstituted carbazol-9-yl group. Examples include compounds in which three or more substituted or unsubstituted carbazol-9-yl groups are bonded to the benzene ring, and compounds in which at least one of the two benzene rings constituting the carbazol-9-yl group is fused with a five-membered ring moiety of a substituted or unsubstituted benzofuran ring, a substituted or unsubstituted benzothiophene ring, a substituted or unsubstituted indole ring, a substituted or unsubstituted indene ring, or a substituted or unsubstituted silaindene ring. A specific example of a group having a structure in which a substituted or unsubstituted benzofuran ring is fused to a benzene ring constituting the carbazol-9-yl group is a substituted or unsubstituted 5H-benzofuro[3,2-c]carbazol-5-yl group.

[0029] As the second organic compound, a compound represented by the following general formula (1) that emits delayed fluorescence can be preferably used. General formula (1) [ka]

[0030] In general formula (1), X 1 ~X 5 represents N or CR. R represents a hydrogen atom, a deuterium atom or a substituent. X 1 ~X 5 When two or more of X represent CR, those CR may be the same or different from each other. 1 ~X 5 At least one of X is CD (where D represents a donor group). 1 ~X 5 When all of the groups are CR, Z represents an acceptor group. Among the compounds represented by general formula (1), particularly preferred compounds are those represented by the following general formula (2). General formula (2) [ka]

[0031] In general formula (2), X 1 ~X 5 represents N or CR. R represents a hydrogen atom, a deuterium atom or a substituent. X 1 ~X 5 When two or more of X represent CR, those CR may be the same or different from each other. 1 ~X 5 At least one of the groups is CD (where D represents a donor group). In a preferred embodiment of the present invention, X 1 ~X 5 is not C-CN. That is, it is a compound having a structure in which one or two cyano groups and at least one donor group are bonded to a benzene ring. In another preferred embodiment of the present invention, X 2 Only represents C-CN, and X 1 , X 3 ~X 5is not C-CN. That is, it is a compound having a structure in which at least one donor group is bonded to the benzene ring of isophthalonitrile. In another embodiment of the present invention, X 3 Only represents C-CN, and X 1 , X 2 , X 4 , X 5 is not C-CN. That is, it is a compound having a structure in which at least one donor group is bonded to the benzene ring of terephthalonitrile.

[0032] The acceptor group represented by Z in general formula (1) is a group that has the property of donating electrons to the ring to which Z is bonded, and can be selected, for example, from groups with a positive Hammett σp value. The donor group represented by D in general formulas (1) and (2) is a group that has the property of withdrawing electrons to the ring to which D is bonded, and can be selected, for example, from groups with a negative Hammett σp value. Hereinafter, the acceptor group may be referred to as A. Here, the "Hammett σp value" was proposed by L.P. Hammett and quantifies the influence of a substituent on the reaction rate or equilibrium of a para-substituted benzene derivative. Specifically, the following equation holds between the substituent in the para-substituted benzene derivative and the reaction rate constant or equilibrium constant: log(k / k0) = ρσp or log(K / K0) = ρσp where k is the rate constant for a benzene derivative having no substituent, k0 is the rate constant for a benzene derivative substituted with a substituent, K is the equilibrium constant for a benzene derivative having no substituent, K0 is the equilibrium constant for a benzene derivative substituted with a substituent, and ρ is a reaction constant determined by the type and conditions of the reaction. For an explanation of the "Hammett σp value" in the present invention and the numerical values ​​of each substituent, please refer to the description of the σp value in Hansch, C. et al., Chem. Rev., 91, 165-195 (1991). Specific examples of the acceptor group include a cyano group and the acceptor groups preferred as A in the general formulae (12) to (14) described below. Specific examples of the donor group include the donor groups preferred as D in the general formulae (12) to (14) described below.

[0033] In the general formula (1) and the general formula (2), X 1 ~X 5 represents N or CR, but at least one is CD. X 1 ~X 5 The number of N is 0 to 4, for example, X 1 and X 3 and X 5 , X 1 and X 3 , X 1 and X 4 , X 2 and X 3 , X 1 and X 5 , X 2 and X 4 , X 1 Only, X 2 Only, X 3 An example can be given where only X is N. 1 ~X 5 The number of CDs is 1 to 5, preferably 2 to 5. For example, X 1 and X 2 and X 3 and X 4 and X 5 , X 1 and X 2 and X 4 and X 5 , X 1 and X 2 and X 3 and X 4 , X 1 and X 3 and X 4 and X 5 , X 1 and X 3 and X 5 , X 1 and X 2 and X 5 , X 1 and X 2 and X4 , X 1 and X 3 and X 4 , X 1 and X 3 , X 1 and X 4 , X 2 and X 3 , X 1 and X 5 , X 2 and X 4 , X 1 Only, X 2 Only, X 3 An example can be given where only X is a CD. 1 ~X 5 At least one of the groups may be CA, where A represents an acceptor group. 1 ~X 5 The number of CA is preferably 0 to 2, and more preferably 0 or 1. Preferred examples of A in CA include a cyano group and a heterocyclic aromatic group having an unsaturated nitrogen atom. 1 ~X 5 may each independently be CD or CA. X 1 ~X 5When two adjacent Rs represent CR, the two Rs may be bonded to each other to form a cyclic structure. The cyclic structure formed by bonding to each other may be an aromatic ring or an aliphatic ring, may contain a heteroatom, and may further be a fused ring of two or more rings. The heteroatom referred to here is preferably selected from the group consisting of a nitrogen atom, an oxygen atom, and a sulfur atom. Examples of the cyclic structure formed include a benzene ring, a naphthalene ring, a pyridine ring, a pyridazine ring, a pyrimidine ring, a pyrazine ring, a pyrrole ring, an imidazole ring, a pyrazole ring, an imidazoline ring, an oxazole ring, an isoxazole ring, a thiazole ring, an isothiazole ring, a cyclohexadiene ring, a cyclohexene ring, a cyclopentaene ring, a cycloheptatriene ring, a cycloheptadiene ring, a cycloheptaene ring, a furan ring, a thiophene ring, a naphthyridine ring, a quinoxaline ring, and a quinoline ring. For example, a ring formed by condensing multiple rings, such as a phenanthrene ring or a triphenylene ring, may be formed.

[0034] The donor group D in the general formula (1) and the general formula (2) is preferably a group represented by the following general formula (3), for example. General formula (3) [ka]

[0035] In general formula (3), R 11 and R 12 R each independently represents a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkenyl group, a substituted or unsubstituted aryl group, or a substituted or unsubstituted heteroaryl group. 11 and R 12may bond to each other to form a cyclic structure. L represents a single bond, a substituted or unsubstituted arylene group, or a substituted or unsubstituted heteroarylene group. The substituent that can be introduced into the arylene group or heteroarylene group of L may be a group represented by general formula (1) or general formula (2), or a group represented by general formulas (3) to (6) described below. These groups represented by (1) to (6) may be introduced up to the maximum number of substituents that can be introduced into L. Furthermore, when multiple groups represented by general formulas (1) to (6) are introduced, these substituents may be the same or different. * represents the bonding position to the carbon atom (C) that constitutes the ring skeleton of the ring in general formula (1) or general formula (2). In this specification, the term "alkyl group" may be linear, branched, or cyclic. It may also contain two or more of the linear, cyclic, and branched moieties. The number of carbon atoms in the alkyl group may be, for example, 1 or more, 2 or more, or 4 or more. The number of carbon atoms may be 30 or less, 20 or less, 10 or less, 6 or less, or 4 or less. Specific examples of the alkyl group include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, an n-pentyl group, an isopentyl group, an n-hexyl group, an isohexyl group, a 2-ethylhexyl group, an n-heptyl group, an isoheptyl group, an n-octyl group, an isooctyl group, an n-nonyl group, an isononyl group, an n-decanyl group, an isodecanyl group, a cyclopentyl group, a cyclohexyl group, and a cycloheptyl group. The alkyl group may be further substituted with an aryl group. The "alkenyl group" may be linear, branched, or cyclic. It may also contain two or more of the linear, cyclic, and branched moieties. The alkenyl group may have, for example, two or more carbon atoms, or four or more carbon atoms. It may also have 30 or less, 20 or less, 10 or less, 6 or less, or 4 or less carbon atoms. Specific examples of the alkenyl group include ethenyl, n-propenyl, isopropenyl, n-butenyl, isobutenyl, n-pentenyl, isopentenyl, n-hexenyl, isohexenyl, and 2-ethylhexenyl. The substituted alkenyl group may be further substituted with a substituent. The "aryl group" and "heteroaryl group" may be a single ring or a fused ring in which two or more rings are fused. In the case of a fused ring, the number of fused rings is preferably 2 to 6, and can be selected from, for example, 2 to 4. Specific examples of the ring include a benzene ring, a pyridine ring, a pyrimidine ring, a triazine ring, a naphthalene ring, an anthracene ring, a phenanthrene ring, a triphenylene ring, a quinoline ring, a pyrazine ring, a quinoxaline ring, and a naphthyridine ring. Specific examples of the aryl group or heteroaryl group include a phenyl group, a 1-naphthyl group, a 2-naphthyl group, a 1-anthracenyl group, a 2-anthracenyl group, a 9-anthracenyl group, a 2-pyridyl group, a 3-pyridyl group, and a 4-pyridyl group. The terms "arylene group" and "heteroaryl group" can be used in the same manner as in the description of the aryl group and heteroaryl group, except that the valence is changed from 1 to 2. The substituent refers to a monovalent group that can be substituted for a hydrogen atom, and does not include condensed groups. For the explanation and preferred range of the substituent, please refer to the explanation and preferred range of the substituent for general formula (7) described later.

[0036] The compound represented by general formula (3) is preferably a compound represented by any one of the following general formulae (4) to (6). General formula (4) [ka] General formula (5) [ka] General formula (6) [ka]

[0037] In the general formulas (4) to (6), R 51 ~R 60 , R 61 ~R 68 , R 71 ~R 78 R each independently represents a hydrogen atom, a deuterium atom, or a substituent. For the explanation and preferred range of the substituents, please refer to the explanation and preferred range of the substituents in general formula (7) described later. 51 ~R 60 , R 61 ~R 68 , R 71 ~R 78 are each preferably independently a group represented by any one of the above general formulas (4) to (6). The number of substituents in general formulas (4) to (6) is not particularly limited. It is also preferable that all are unsubstituted (i.e., hydrogen atoms or deuterium atoms). Furthermore, when there are two or more substituents in each of general formulas (4) to (6), these substituents may be the same or different. When a substituent is present in general formula (4), the substituent is R 52 ~R 59 In the case of general formula (5), R 62 ~R 67 In the case of general formula (6), R 72 ~R 77 It is preferable that either of the above is used.

[0038] In general formula (6), X represents a divalent oxygen atom, sulfur atom, substituted or unsubstituted nitrogen atom, substituted or unsubstituted carbon atom, substituted or unsubstituted silicon atom, or carbonyl group, each of which has a linking chain length of 1 atom, or a divalent substituted or unsubstituted ethylene group, substituted or unsubstituted vinylene group, substituted or unsubstituted o-arylene group, or substituted or unsubstituted o-heteroarylene group, each of which has a linking chain length of 2 atoms. Specific examples and preferred ranges of the substituents can be found in the descriptions of the substituents in general formulas (1) and (2) above.

[0039] In the general formulas (4) to (6), L 12 ~L 14 represents a single bond, a substituted or unsubstituted arylene group, or a substituted or unsubstituted heteroarylene group. 12 ~L 14 For the description and preferred range of the arylene group or heteroarylene group represented by, reference can be made to the description and preferred range of the arylene group or heteroarylene group represented by L. 12 ~L 14 is preferably a single bond or a substituted or unsubstituted arylene group. The substituent of the arylene group or heteroarylene group may be a group represented by any one of the general formulae (1) to (6). The group represented by any one of the general formulae (1) to (6) is L. 11 ~L 14 The maximum number of substituents that can be introduced into the ring may be introduced. When a plurality of groups represented by general formulas (1) to (6) are introduced, the substituents may be the same or different. * indicates the bonding position to the carbon atom (C) that constitutes the ring skeleton of the ring in general formula (1) or general formula (2).

[0040] In the general formulas (4) to (6), R 51 and R 52 , R 52 and R 53 , R 53 and R 54 , R 54 and R 55 , R 55 and R 56 , R 56and R 57 , R 57 and R 58 , R 58 and R 59 , R 59 and R 60 , R 61 and R 62 , R 62 and R 63 , R 63 and R 64 , R 65 and R 66 , R 66 and R 67 , R 67 and R 68 , R 71 and R 72 , R 72 and R 73 , R 73 and R 74 , R 75 and R 76 , R 76 and R 77 , R 77 and R 78 may be bonded to each other to form a cyclic structure. For details and preferred examples of the cyclic structure, see X in the above general formula (1) and general formula (2). 1 ~X 5 The description of the cyclic structure and preferred examples thereof can be referred to.

[0041] Among the cyclic structures, preferred are structures in which a substituted or unsubstituted benzofuran ring, a substituted or unsubstituted benzothiophene ring, a substituted or unsubstituted indole ring, a substituted or unsubstituted indene ring, or a substituted or unsubstituted silaindene ring is fused to at least one benzene ring of general formulas (4) to (6). More preferred are groups represented by the following general formulas (5a) to (5f) fused to general formula (5). [ka]

[0042] In the general formulas (5a) to (5f), L 11 and L 21 ~L 26 represents a single bond or a divalent linking group.11 and L 21 ~L 26 For a description and preferred range of 2 Reference can be made to the description and preferred ranges of In the general formulas (5a) to (5f), R 41 ~R 110 R each independently represents a hydrogen atom or a substituent. 41 and R 42 , R 42 and R 43 , R 43 and R 44 , R 44 and R 45 , R 45 and R 46 , R 46 and R 47 , R 47 and R 48 , R 51 and R 52 , R 52 and R 53 , R 53 and R 54 , R 54 and R 55 , R 55 and R 56 , R 56 and R 57 , R 57 and R 58 , R 58 and R 59 , R 59 and R 60 , R 61 and R 62 , R 62 and R 63 , R 63 and R 64 , R 65 and R 66 , R 66 and R 67 , R 67 and R 68 , R 68 and R 69 , R 69 and R 70 , R 72 and R 73 , R 73 and R 74 , R 74 and R 75 , R 75and R 76 , R 76 and R 77 , R 77 and R 78 , R 78 and R 79 , R 79 and R 80 , R 81 and R 82 , R 82 and R 83 , R 83 and R 84 , R 84 and R 85 , R 86 and R 87 , R 87 and R 88 , R 88 and R 89 , R 89 and R 90 , R 91 and R 92 , R 93 and R 94 , R 94 and R 95 , R 95 and R 96 , R 96 and R 97 , R 97 and R 98 , R 99 and R 100 , R 101 and R 102 , R 102 and R 103 , R 103 and R 104 , R 104 and R 105 , R 105 and R 106 , R 107 and R 108 , R 108 and R 109 , R 109 and R 110may be bonded to each other to form a cyclic structure. The cyclic structure formed by bonding to each other may be an aromatic ring or an aliphatic ring, may contain a heteroatom, and may further be a fused ring of two or more rings. The heteroatom referred to here is preferably selected from the group consisting of a nitrogen atom, an oxygen atom, and a sulfur atom. Examples of the cyclic structure formed include a benzene ring, a naphthalene ring, a pyridine ring, a pyridazine ring, a pyrimidine ring, a pyrazine ring, a pyrrole ring, an imidazole ring, a pyrazole ring, an imidazoline ring, an oxazole ring, an isoxazole ring, a thiazole ring, an isothiazole ring, a cyclohexadiene ring, a cyclohexene ring, a cyclopentaene ring, a cycloheptatriene ring, a cycloheptadiene ring, a cycloheptaene ring, a furan ring, a thiophene ring, a naphthyridine ring, a quinoxaline ring, and a quinoline ring. For example, a ring formed by condensing multiple rings, such as a phenanthrene ring or a triphenylene ring, may also be formed. The number of rings contained in the group represented by general formula (6) may be selected from the range of 3 to 5, or may be selected from the range of 5 to 7. The number of rings contained in the groups represented by general formulas (5a) to (5f) may be selected from the range of 5 to 7, or may be 5. R 41 ~R 110 Examples of the substituent that R may have include the groups in the above-mentioned substituent group B, and preferably an unsubstituted alkyl group having 1 to 10 carbon atoms or an aryl group having 6 to 10 carbon atoms which may be substituted with an unsubstituted alkyl group having 1 to 10 carbon atoms. In a preferred embodiment of the present invention, R 41 ~R 110 is a hydrogen atom or an unsubstituted alkyl group having 1 to 10 carbon atoms. In a preferred embodiment of the present invention, R 41 ~R 110 is a hydrogen atom or an unsubstituted aryl group having 6 to 10 carbon atoms. In a preferred embodiment of the present invention, R 41 ~R 110 are all hydrogen atoms. R in general formulas (5a) to (5f) 41 ~R 110The carbon atoms to which CR is bonded (carbon atoms constituting the ring skeleton) may each independently be substituted with a nitrogen atom. 41 ~CR 110 may each independently be substituted with N. The number of nitrogen atoms substituted is preferably 0 to 4, and more preferably 1 to 2, among the groups represented by general formulas (5a) to (5f). In one embodiment of the present invention, the number of nitrogen atoms substituted is 0. Furthermore, when two or more groups are substituted with nitrogen atoms, the number of nitrogen atoms substituted in one ring is preferably 1. In the general formulae (5a) to (5f), X 1 ~X 6 represents an oxygen atom, a sulfur atom or NR. In one embodiment of the present invention, X 1 ~X 6 is an oxygen atom. In one aspect of the present invention, X 1 ~X 6 is a sulfur atom. In one embodiment of the present invention, X 1 ~X 6 is NR. R represents a hydrogen atom or a substituent, and is preferably a substituent. Examples of the substituent include a substituent selected from the above-mentioned Substituent Group A. For example, an unsubstituted phenyl group or a phenyl group substituted with one group or a combination of two or more groups selected from the group consisting of alkyl groups and aryl groups can be preferably used. In the general formulae (5a) to (5f), * represents a bonding position.

[0043] In the present invention, a compound that is represented by the following general formula (7) and emits delayed fluorescence can be particularly preferably used as the delayed fluorescence material. In a preferred embodiment of the present invention, the compound represented by general formula (7) can be used as the second organic compound. General formula (7) [ka]

[0044] In general formula (7), R 1 ~R5 0 to 4 represent a cyano group, and R 1 ~R 5 At least one of R represents a substituted amino group, and the remaining R 1 ~R 5 represents a hydrogen atom, a deuterium atom, or a substituent other than a cyano group or a substituted amino group. The substituted amino group referred to here is preferably a substituted or unsubstituted diarylamino group, and the two aryl groups constituting the substituted or unsubstituted diarylamino group may be linked to each other. The linkage may be by a single bond (in which case a carbazole ring is formed), or by -O-, -S-, -N(R 6 )-, -C(R 7 )(R 8 )-, -Si(R 9 )(R 10 )-, or other linking groups. 6 ~R 10 represents a hydrogen atom, a deuterium atom or a substituent, and R 7 and R 8 , R 9 and R 10 may be linked to each other to form a cyclic structure. Substituted amino group is R 1 ~R 5 For example, R 1 and R 2 , R 1 and R 3 , R 1 and R 4 , R 1 and R 5 , R 2 and R 3 , R 2 and R 4 , R 1 and R 2 and R 3 , R 1 and R 2 and R 4 , R 1 and R 2 and R 5 , R 1 and R 3 and R 4 , R 1 and R 3 and R5 , R 2 and R 3 and R 4 , R 1 and R 2 and R 3 and R 4 , R 1 and R 2 and R 3 and R 5 , R 1 and R 2 and R 4 and R 5 , R 1 and R 2 and R 3 and R 4 and R 5 can be a substituted amino group. A cyano group can also be 1 ~R 5 For example, R 1 , R 2 , R 3 , R 1 and R 2 , R 1 and R 3 , R 1 and R 4 , R 1 and R 5 , R 2 and R 3 , R 2 and R 4 , R 1 and R 2 and R 3 , R 1 and R 2 and R 4 , R 1 and R 2 and R 5 , R 1 and R 3 and R 4 , R 1 and R 3 and R 5 , R 2 and R 3 and R 4 can be a cyano group. R is neither a cyano group nor a substituted amino group 1 ~R 5represents a hydrogen atom, a deuterium atom, or a substituent. Examples of the substituent include a hydroxyl group, a halogen atom (e.g., a fluorine atom, a chlorine atom, a bromine atom, or an iodine atom), an alkyl group (e.g., having 1 to 40 carbon atoms), an alkoxy group (e.g., having 1 to 40 carbon atoms), an alkylthio group (e.g., having 1 to 40 carbon atoms), an aryl group (e.g., having 6 to 30 carbon atoms), an aryloxy group (e.g., having 6 to 30 carbon atoms), an arylthio group (e.g., having 6 to 30 carbon atoms), a heteroaryl group (e.g., having 5 to 30 ring skeleton atoms), a heteroaryloxy group (e.g., having 5 to 30 ring skeleton atoms), and a heteroarylthio group. (e.g., having 5 to 30 ring skeleton atoms), acyl group (e.g., having 1 to 40 carbon atoms), alkenyl group (e.g., having 1 to 40 carbon atoms), alkynyl group (e.g., having 1 to 40 carbon atoms), alkoxycarbonyl group (e.g., having 1 to 40 carbon atoms), aryloxycarbonyl group (e.g., having 1 to 40 carbon atoms), heteroaryloxycarbonyl group (e.g., having 1 to 40 carbon atoms), silyl group (e.g., a trialkylsilyl group having 1 to 40 carbon atoms), nitro group, and substituent group A consisting of the groups enumerated here further substituted with one or more groups enumerated here. Preferred examples of the substituent when the aryl group of the diarylamino group is substituted also include the substituents in substituent group A above, and further include a cyano group and a substituted amino group. For specific examples of compounds and compounds encompassed by general formula (7), reference can be made to paragraphs 0008 to 0048 of WO2013 / 154064, paragraphs 0009 to 0030 of WO2015 / 080183, paragraphs 0006 to 0019 of WO2015 / 129715, paragraphs 0013 to 0025 of JP2017-119663A, and paragraphs 0013 to 0026 of JP2017-119664A, all of which are incorporated herein by reference.

[0045] In addition, a compound that is represented by the following general formula (8) and emits delayed fluorescence can also be particularly preferably used as the delayed fluorescence material of the present invention. In a preferred embodiment of the present invention, the compound represented by general formula (8) can be used as the second organic compound. General formula (8) [ka]

[0046] In the general formula (8), Y 1 , Y 2 and Y 3 Two of them are nitrogen atoms and the remaining one is a methine group, or Y 1 , Y 2 and Y 3 All of these represent nitrogen atoms. 1 and Z 2 R each independently represents a hydrogen atom, a deuterium atom, or a substituent. 11 ~R 18 each independently represents a hydrogen atom, a deuterium atom, or a substituent; R 11 ~R 18 At least one of the arylamino group and the carbazolyl group is preferably a substituted or unsubstituted arylamino group or a substituted or unsubstituted carbazolyl group. The benzene ring constituting the arylamino group and the benzene ring constituting the carbazolyl group are each represented by R 11 ~R 18 may form a single bond or a linking group together with Z. Furthermore, the compound represented by general formula (8) contains at least two carbazole structures in the molecule. 1 , Z 2 Examples of the substituent that R may take include the substituents in the above-mentioned Substituent Group A. 11 ~R 18 Specific examples of the substituents that the arylamino group and carbazolyl group may have include the substituents in the above-mentioned substituent group A, a cyano group, a substituted arylamino group, and a substituted alkylamino group. 11 and R 12 , R 12 and R 13 , R 13 and R 14 , R 15 and R 16 , R 16 and R 17 , R 17 and R 18 may be bonded to each other to form a cyclic structure. Among the compounds represented by general formula (8), the compounds represented by general formula (9) are particularly useful. General formula (9) [ka]

[0047] In the general formula (9), Y 1 , Y 2 and Y 3 Two of them are nitrogen atoms and the remaining one is a methine group, or Y 1 , Y 2 and Y 3 All of these represent nitrogen atoms. 2 represents a hydrogen atom, a deuterium atom, or a substituent. 11 ~R 18 and R 21 ~R 28 R each independently represents a hydrogen atom, a deuterium atom, or a substituent. 11 ~R 18 At least one of and / or R 21 ~R 28 At least one of the arylamino group and the carbazolyl group preferably represents a substituted or unsubstituted arylamino group or a substituted or unsubstituted carbazolyl group. The benzene ring constituting the arylamino group and the benzene ring constituting the carbazolyl group are each represented by R 11 ~R 18 or R 21 ~R 28 Z may be taken together with Z to form a single bond or a linking group. 2 Examples of the substituent that R may take include the substituents in the above-mentioned Substituent Group A. 11 ~R 18 , R 21 ~R 28 Specific examples of the substituents that the arylamino group and carbazolyl group may have include the substituents in the above-mentioned substituent group A, a cyano group, a substituted arylamino group, and a substituted alkylamino group. 11 and R 12 , R 12 and R 13 , R 13 and R 14, R 15 and R 16 , R 16 and R 17 , R 17 and R 18 , R 21 and R 22 , R 22 and R 23 , R 23 and R 24 , R 25 and R 26 , R 26 and R 27 , R 27 and R 28 may be bonded to each other to form a cyclic structure. For specific examples of compounds and compounds included in general formula (9), reference can be made to paragraphs 0020 to 0062 of WO2013 / 081088, which is incorporated herein by reference, and the compounds described in Appl. Phys. Lett., 98, 083302 (2011).

[0048] Furthermore, a compound that is represented by the following general formula (10) and emits delayed fluorescence can also be particularly preferably used as the delayed fluorescence material of the present invention. General formula (10) [ka]

[0049] In general formula (10), R 91 ~R 96 Each of R independently represents a hydrogen atom, a deuterium atom, a donor group, or an acceptor group, at least one of which is the donor group and at least two of which are the acceptor groups. The substitution positions of the at least two acceptor groups are not particularly limited, but it is preferable that the compound contains two acceptor groups that are in a meta-position relationship with each other. For example, R 91 is a donor group, at least R 92 and R 94 is an acceptor group, or at least R 92 and R 96is an acceptor group. The acceptor groups present in the molecule may all be the same or different from one another, and for example, a structure in which they are all the same can be selected. The number of acceptor groups is preferably 2 to 3, and for example, 2 can be selected. Two or more donor groups may be present, and in that case, the donor groups may all be the same or different from one another. The number of donor groups is preferably 1 to 3, and may be, for example, one or two. For the explanation and preferred ranges of the donor group and the acceptor group, please refer to the explanation and preferred ranges of D and Z in general formula (1). In particular, in general formula (10), the donor group is preferably represented by general formula (3), and the acceptor group is preferably a cyano group or the following general formula (11). General formula (11) [ka]

[0050] In the general formula (11), Y 4 ~Y 6 represents a nitrogen atom or a methine group, at least one of which is a nitrogen atom, and preferably all of which are nitrogen atoms. 101 ~R 110 Each of L independently represents a hydrogen atom, a deuterium atom, or a substituent, and at least one of them is preferably an alkyl group. For the explanation and preferred range of the substituents, please refer to the explanation and preferred range of the substituents in the general formula (7) above. 15 represents a single bond or a linking group, and the description and preferred range of L in the general formula (3) can be referred to. In a preferred embodiment of the present invention, L in the general formula (11) 15 is a single bond. * represents the bonding position to the carbon atom (C) constituting the ring skeleton of the ring in general formula (10).

[0051] In another preferred embodiment of the present invention, the second organic compound may be a compound represented by general formula (12). Compounds represented by general formula (12) include compounds represented by general formula (12a). General formula (12) [ka] General formula (12a) [ka]

[0052] Among the compounds represented by general formula (12), particularly preferred compounds are compounds represented by the following general formula (13) and general formula (14). General formula (13) [ka] General formula (14) [ka]

[0053] In another preferred embodiment of the present invention, a compound represented by general formula (15) can be used as the second organic compound. [ka]

[0054] In general formulas (12) to (15), D represents a donor group, A represents an acceptor group, and R represents a hydrogen atom, a deuterium atom, or a substituent. The two Ds in general formula (15) may be the same or different. For descriptions and preferred ranges of the donor group and the acceptor group, reference may be made to the corresponding descriptions and preferred ranges for general formula (1) above. Examples of the substituent for R include an alkyl group and an aryl group optionally substituted with one or a combination of two or more groups selected from the group consisting of alkyl groups and aryl groups. Specific examples of donor groups preferred as D in general formulas (12) to (15) are listed below. In the following specific examples, * represents the bonding position, and "D" represents a deuterium atom. In the following specific examples, the hydrogen atom may be substituted with, for example, an alkyl group. Furthermore, a substituted or unsubstituted benzene ring may be further condensed. [ka] [ka]

[0055] Specific examples of the acceptor group preferred as A in general formulae (12) to (14) are listed below: In the following specific examples, * represents the bonding position, and "D" represents deuterium. [ka] [ka]

[0056] Preferred examples of R in the general formulae (12) to (15) are given below: In the following specific examples, * represents the bonding position, and "D" represents deuterium. [ka]

[0057] Among the compounds represented by the general formula (15), a particularly preferred compound is a compound represented by the following general formula (15a): General formula (15a) [ka]

[0058] In general formula (15a), R 201 ~R 221R each independently represents a hydrogen atom or a substituent, and preferably represents a hydrogen atom, an alkyl group, an aryl group, or a group in which an alkyl group and an aryl group are bonded. 201 and R 202 , R 202 and R 203 , R 203 and R 204 , R 205 and R 206 , R 206 and R 207 , R 207 and R 208 , R 214 and R 215 , R 215 and R 216 , R 216 and R 217 , R 218 and R 219 , R 219 and R 220 , R 220 and R 221 At least one pair of R is bonded to each other to form a benzofuro structure or a benzothieno structure. 201 and R 202 , R 202 and R 203 , R 203 and R 204 , R 205 and R 206 , R 206 and R 207 , R 207 and R 208 One or two pairs of R 214 and R 215 , R 215 and R 216 , R 216 and R 217 , R 218 and R 219 , R 219 and R 220 , R 220 and R 221 One or two of the groups are bonded to each other to form a benzofuro structure or a benzothieno structure. 203 and R 204 are bonded to each other to form a benzofuro or benzothieno structure, and even more preferably R 203 and R 204, R 216 and R 217 are bonded to each other to form a benzofuro structure or a benzothieno structure. Particularly preferably, R 203 and R 204 , R 216 and R 217 are bonded to each other to form a benzofuro or benzothieno structure, and R 206 and R 219 is a substituted or unsubstituted aryl group (preferably a substituted or unsubstituted phenyl group, more preferably an unsubstituted phenyl group). In general formula (15a), some or all of the hydrogen atoms may be substituted with deuterium atoms. For example, some or all of the hydrogen atoms of the two phenyl groups bonded to the triazinyl group may be substituted with deuterium atoms. In addition, some or all of the hydrogen atoms bonded to the two carbazolyl groups may be substituted with deuterium atoms. In addition, R 209 ~R 213 may be a deuterium atom.

[0059] Preferred compounds that can be used as the second organic compound are listed below: In the structural formulas of the following exemplary compounds, t-Bu represents a tertiary butyl group. [ka] [ka] [ka] [ka] [ka] [ka] [ka] [ka] [ka] [ka] [ka] [ka] [ka] [ka]

[0060] In addition to the above, known delayed fluorescent materials can be appropriately combined and used as the second organic compound. Even unknown delayed fluorescent materials can be used. In particular, the compounds represented by the general formula (1) described in paragraphs 0013 to 0042 of the specification of Japanese Patent Application No. 2021-188860, which is incorporated herein by reference, and in particular the compounds described in paragraphs 0043 to 0048, can be preferably used. As delayed fluorescent materials, paragraphs 0008 to 0048 and 0095 to 0133 of WO2013 / 154064, paragraphs 0007 to 0047 and 0073 to 0085 of WO2013 / 011954, paragraphs 0007 to 0033 and 0059 to 0066 of WO2013 / 011955, paragraphs 0008 to 007 of WO2013 / 081088 1 and 0118 to 0133, paragraphs 0009 to 0046 and 0093 to 0134 of JP 2013-256490 A, paragraphs 0008 to 0020 and 0038 to 0040 of JP 2013-116975 A, paragraphs 0007 to 0032 and 0079 to 0084 of WO2013 / 133359 A, paragraphs 0008 to 0032 of WO2013 / 161437 A 0054 and 0101 to 0121, paragraphs 0007 to 0041 and 0060 to 0069 of JP 2014-9352 A, paragraphs 0008 to 0048 and 0067 to 0076 of JP 2014-9224 A, paragraphs 0013 to 0025 of JP 2017-119663 A, paragraphs 0013 to 0026 of JP 2017-119664 A, Examples include compounds encompassed by the general formulas described in paragraphs 0012 to 0025 of JP 222623 A, paragraphs 0010 to 0050 of JP 2017-226838 A, paragraphs 0012 to 0043 of JP 2018-100411 A, and paragraphs 0016 to 0044 of WO 2018 / 047853 A, particularly exemplary compounds that emit delayed fluorescence.Also, Japanese Patent Application Laid-Open No. 2013-253121, WO2013 / 133359, WO2014 / 034535, WO2014 / 115743, WO2014 / 122895, WO2014 / 126200, WO2014 / 136758, WO2014 / 133121, WO2014 / 136860, WO2014 / 196585, WO2014 / 189122, WO2014 / 168101, WO2015 / 00858 0 publication, WO2014 / 203840 publication, WO2015 / 002213 publication, WO2015 / 016200 publication, WO2015 / 019725 publication, WO2015 / 072470, WO2015 / 108049, WO2015 / 080182, WO2015 / 072537, WO2015 / 080183, JP2015-129240A, WO2015 / 129714, WO2015 / 129715, WO2015 / 133 It is also possible to employ luminescent materials that emit delayed fluorescence, such as those described in WO2015 / 136880, WO2015 / 137244, WO2015 / 137202, WO2015 / 137136, WO2015 / 146541, and WO2015 / 159541. The above publications described in this paragraph are incorporated herein by reference.

[0061] (Third organic compound) The third organic compound used in the light-emitting layer of the organic electroluminescent device of the present invention is a compound that emits fluorescence and has a lower LUMO energy than the first organic compound and the second organic compound. The third organic compound is preferably a compound that emits fluorescence, has a lower LUMO energy than the first organic compound and the second organic compound, and has a lower minimum excited singlet energy than the first organic compound and the second organic compound. In the organic electroluminescent device of the present invention, the orientation value of the third organic compound in the light-emitting layer is −0.3 or less. The organic electroluminescent device of the present invention emits fluorescence derived from the third organic compound. The light emission from the third organic compound usually includes delayed fluorescence. The largest component of the light emission from the device is fluorescence from the third organic compound. That is, the amount of fluorescence emitted from the third organic compound is the largest among the light emission from the organic electroluminescent device of the present invention. In a preferred embodiment of the present invention, the third organic compound receives energy from the first organic compound in an excited singlet state, the second organic compound in an excited singlet state, and the second organic compound that has undergone reverse intersystem crossing from an excited triplet state to reach the excited singlet state, thereby transitioning to the excited singlet state. In a more preferred embodiment of the present invention, the third organic compound receives energy from the second organic compound in an excited singlet state and the second organic compound that has undergone reverse intersystem crossing from the excited triplet state to reach the excited singlet state, thereby transitioning to the excited singlet state. The resulting excited singlet state of the third organic compound then emits fluorescence when it returns to the ground state. The third organic compound can be any fluorescent material (fluorescent compound) that satisfies certain conditions. Here, the term "fluorescent material" refers to a material that emits fluorescence with an emission lifetime of less than 100 ns (nanoseconds) when measured using a fluorescence lifetime measurement system (such as a streak camera system manufactured by Hamamatsu Photonics). The emission from the third organic compound may include delayed fluorescence and phosphorescence, but the largest component of the emission from the third organic compound is fluorescence. In one embodiment of the present invention, the organic electroluminescent device does not emit phosphorescence, or the amount of phosphorescence emitted is 1% or less of that of fluorescence.

[0062] Two or more third organic compounds may be used as long as they satisfy the conditions of the present invention. For example, by using two or more third organic compounds with different luminescent colors in combination, it becomes possible to emit light of a desired color. Alternatively, a single type of third organic compound may be used to emit monochromatic light from the third organic compound. In the present invention, the maximum emission wavelength of the compound that can be used as the third organic compound is not particularly limited. Therefore, it is possible to appropriately select and use a luminescent material having a maximum emission wavelength in the visible region (380 to 780 nm), a luminescent material having a maximum emission wavelength in the infrared region (780 nm to 1 mm), or a compound having a maximum emission wavelength in the ultraviolet region (e.g., 280 to 380 nm). Fluorescent materials having a maximum emission wavelength in the visible region are preferred. For example, within the 380 to 780 nm region, a luminescent material having a maximum emission wavelength in the range of 380 to 570 nm, a luminescent material having a maximum emission wavelength in the range of 570 to 650 nm, a luminescent material having a maximum emission wavelength in the range of 650 to 700 nm, or a luminescent material having a maximum emission wavelength in the range of 700 to 780 nm may be selected and used. In a preferred embodiment of the present invention, the second organic compound and the third organic compound are selected and combined so that there is overlap between the emission wavelength range of the second organic compound and the absorption wavelength range of the third organic compound. In particular, it is preferred that the short-wavelength edge of the emission spectrum of the second organic compound overlaps with the long-wavelength edge of the absorption spectrum of the third organic compound. The third organic compound preferably does not contain any metal atoms other than boron atoms. For example, the third organic compound may be a compound containing both boron atoms and fluorine atoms. Alternatively, the third organic compound may be a compound containing boron atoms but not fluorine atoms. Alternatively, the third organic compound may contain no metal atoms at all. For example, the third organic compound may be a compound containing atoms selected from the group consisting of carbon atoms, hydrogen atoms, deuterium atoms, nitrogen atoms, oxygen atoms, sulfur atoms, fluorine atoms, and boron atoms. For example, the third organic compound may be a compound containing atoms selected from the group consisting of carbon atoms, hydrogen atoms, deuterium atoms, nitrogen atoms, oxygen atoms, fluorine atoms, and boron atoms. For example, the third organic compound may be a compound containing atoms selected from the group consisting of carbon atoms, hydrogen atoms, deuterium atoms, nitrogen atoms, oxygen atoms, sulfur atoms, and boron atoms. For example, the third organic compound may be a compound containing atoms selected from the group consisting of carbon atoms, hydrogen atoms, deuterium atoms, nitrogen atoms, oxygen atoms, sulfur atoms, and boron atoms. For example, the third organic compound may be a compound containing atoms selected from the group consisting of carbon atoms, hydrogen atoms, deuterium atoms, nitrogen atoms, oxygen atoms, sulfur atoms, and boron atoms. For example, the third organic compound may be a compound consisting of atoms selected from the group consisting of carbon atoms, hydrogen atoms, deuterium atoms, nitrogen atoms, oxygen atoms, and sulfur atoms. For example, the third organic compound may be a compound consisting of atoms selected from the group consisting of carbon atoms, hydrogen atoms, deuterium atoms, nitrogen atoms, and oxygen atoms. For example, the third organic compound may be a compound consisting of carbon atoms and hydrogen atoms.

[0063] Examples of the third organic compound include compounds exhibiting the multiple resonance effect of boron and nitrogen atoms, and compounds containing a fused aromatic ring structure such as anthracene, pyrene, and perylene. Other examples of the third organic compound include compounds containing boron and nitrogen atoms that exhibit the multiple resonance effect and have a fused ring structure with four or more constituent rings. Further examples of the third organic compound include compounds having a structure in which a pyrrole ring and two benzene rings that share the nitrogen atom are fused to a six-membered heterocyclic ring containing a boron atom and a nitrogen atom. In a preferred embodiment of the present invention, a compound represented by the following general formula (16) is used as the third organic compound. General formula (16) [ka]

[0064] In general formula (16), X 1 and X 2 In one embodiment of the present invention, X is a nitrogen atom and the other is a boron atom. 1 is a nitrogen atom, and X 2 is a boron atom. In this case, R 17 and R 18 are bonded to each other as a single bond to form a pyrrole ring. 1 is a boron atom, and X 2 is a nitrogen atom. In this case, R 21 and R 22 are bonded to each other to form a single bond to form a pyrrole ring.

[0065] In general formula (16), R 1 ~R 26 , A 1 , A 2 each independently represents a hydrogen atom, a deuterium atom, or a substituent. R 1 and R 2 , R 2 and R 3 , R 3 and R 4 , R 4 and R 5 , R 5 and R 6 , R 6 and R 7 , R 7 and R 8 , R 8 and R 9 , R 9 and R 10 , R 10 and R 11 , R 11 and R 12 , R 13 and R 14 , R 14 and R15 , R 15 and R 16 , R 16 and R 17 , R 17 and R 18 , R 18 and R 19 , R 19 and R 20 , R 20 and R 21 , R 21 and R 22 , R 22 and R 23 , R 23 and R 24 , R 24 and R 25 , R 25 and R 26 may be bonded to each other to form a cyclic structure. R 7 and R 8 The ring structure formed by the bonding of R contains a boron atom and four carbon atoms as ring skeletal constituent atoms. 17 and R 18 The ring structure formed by bonding is X 1 When X is a boron atom, the ring structure contains a boron atom and four carbon atoms. 1 When R is a nitrogen atom, the cyclic structure is limited to a pyrrole ring. 21 and R 22 The ring structure formed by bonding is X 2 When X is a boron atom, the ring structure contains a boron atom and four carbon atoms. 2 When R is a nitrogen atom, the cyclic structure is limited to a pyrrole ring. 7 and R 8 , R 17 and R 18 , R 21 and R 22 When R are bonded to each other to form a cyclic structure containing a boron atom, the cyclic structure is preferably a 5- to 7-membered ring, more preferably a 5- or 6-membered ring, and even more preferably a 6-membered ring. 7 and R 8 , R 17 and R 18 , R 21 and R 22When they bond to each other, they bond to each other to form a single bond, -O-, -S-, -N(R 27 )-, -C(R 28 )(R 29 )-, -Si(R 30 )(R 31 )-, -B(R 32 )-, -CO-, -CS-, and preferably forms -O-, -S- or -N(R 27 )-, and more preferably -N(R 27 It is more preferred to form a )-, where R 27 ~R 32 Each of R independently represents a hydrogen atom, a deuterium atom, or a substituent. The substituent may be a group selected from any of the substituent groups A to E described below, but is preferably a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, or a substituted or unsubstituted heteroaryl group, and particularly preferably R 27 is preferably a substituted or unsubstituted aryl group. 27 ~R 32 When is a substituent, R 7 and R 8 R in the ring formed by bonding together 27 ~R 32 is R 6 and R 9 may further bond to at least one of R to form a cyclic structure, 17 and R 18 R in the ring formed by bonding together 27 ~R 32 is R 16 and R 19 may further bond to at least one of R to form a cyclic structure, 21 and R 22 R in the ring formed by bonding together 27 ~R 32 is R 20 and R 23 In one embodiment of the present invention, R 7 and R 8 , R 17 and R 18 , R 21 and R 22In one embodiment of the present invention, only one pair of R 7 and R 8 , R 17 and R 18 , R 21 and R 22 In one embodiment of the present invention, only two pairs of R 7 and R 8 , R 17 and R 18 , R 21 and R 22 All of these are connected to each other.

[0066] R 1 and R 2 , R 2 and R 3 , R 3 and R 4 , R 4 and R 5 , R 5 and R 6 , R 6 and R 7 , R 8 and R 9 , R 9 and R 10 , R 10 and R 11 , R 11 and R 12 , R 13 and R 14 , R 14 and R 15 , R 15 and R 16 , R 16 and R 17 , R 18 and R 19 , R 19 and R 20 , R 20 and R 21 , R 22 and R 23 , R 23 and R 24 , R 24 and R 25 , R 25 and R 26The cyclic structure formed by bonding together may be an aromatic ring or an aliphatic ring, may contain a heteroatom, and may further be fused with one or more other rings. The heteroatom here is preferably selected from the group consisting of a nitrogen atom, an oxygen atom, and a sulfur atom. Examples of the cyclic structure formed include a benzene ring, a pyridine ring, a pyridazine ring, a pyrimidine ring, a pyrazine ring, a pyrrole ring, an imidazole ring, a pyrazole ring, a triazole ring, an imidazoline ring, a furan ring, a thiophene ring, an oxazole ring, an isoxazole ring, a thiazole ring, an isothiazole ring, a cyclohexadiene ring, a cyclohexene ring, a cyclopentene ring, a cycloheptatriene ring, a cycloheptadiene ring, a cycloheptene ring, and a ring further fused with one or more rings selected from the group consisting of these rings. In a preferred embodiment of the present invention, the cyclic structure is a substituted or unsubstituted benzene ring (which may be further fused with a ring), for example, a benzene ring optionally substituted with an alkyl group or an aryl group. In a preferred embodiment of the present invention, the cyclic structure is a substituted or unsubstituted heteroaromatic ring, preferably a furan ring of benzofuran or a thiophene ring of benzothiophene. 1 and R 2 , R 2 and R 3 , R 3 and R 4 , R 4 and R 5 , R 5 and R 6 , R 6 and R 7 , R 8 and R 9 , R 9 and R 10 , R 10 and R 11 , R 11 and R 12 , R 13 and R 14 , R 14 and R 15 , R 15 and R 16 , R 16 and R 17 , R 18 and R 19 , R 19and R 20 , R 20 and R 21 , R 22 and R 23 , R 23 and R 24 , R 24 and R 25 , R 25 and R 26 Among these, the number of combinations that are bonded to each other to form a cyclic structure may be 0, or may be, for example, any of 1 to 6. For example, it may be any of 1 to 4, and 1, 2, 3, or 4 may be selected. In one embodiment of the present invention, R 1 and R 2 , R 2 and R 3 , R 3 and R 4 In one embodiment of the present invention, a pair of R 5 and R 6 are bonded to each other to form a ring structure. 9 and R 10 , R 10 and R 11 , R 11 and R 12 In one embodiment of the present invention, a pair of R 1 and R 2 , R 13 and R 14 are bonded to each other to form a cyclic structure. 1 and R 2 , R 2 and R 3 , R 3 and R 4 are bonded to each other to form a cyclic structure, and R 5 and R 6 are bonded to each other to form a ring structure. 5 and R 6 , R 19 and R 20 are all bonded to each other to form a ring structure.

[0067] Adjacent R n (n=1-26) and R that are not bonded to each other 1 ~R 26 is a hydrogen atom, a deuterium atom, or a substituent. As the substituent, a group selected from any one of the groups A to E of substituents described below can be used. R 1 ~R 26 Preferred substituents that R may have are substituted or unsubstituted alkyl groups, substituted or unsubstituted aryl groups, and substituted or unsubstituted heteroaryl groups. For example, the substituent may be a substituted or unsubstituted aryl group, or for example, the substituent may be a substituted or unsubstituted alkyl group. The substituents of the alkyl group, aryl group, and heteroaryl group mentioned here can also be groups selected from any of the substituent groups A to E, but are preferably one or more groups selected from the group consisting of alkyl groups, aryl groups, and heteroaryl groups, and more preferably groups from the substituent group E, which may be unsubstituted. In one preferred embodiment of the present invention, R 1 ~R 6 At least one of R is a substituent, preferably a group of the substituent group E. For example, R 1 ~R 6 At least one of R is a substituent, preferably a group of the substituent group E. For example, R 5 and R 6 At least one of R is a substituent, preferably a group of the substituent group E. In a preferred embodiment of the present invention, 3 and R 6 At least one of X is a substituent, more preferably both are substituents, and are preferably groups in the substituent group E. In a preferred embodiment of the present invention, 1 is a nitrogen atom, R 15 and R 20 At least one of R is a substituent, more preferably both are substituents, and are preferably groups in the substituent group E. 16 and R 17 In a preferred embodiment of the present invention, X 2 is a nitrogen atom, R 19 and R 24At least one of R is a substituent, more preferably both are substituents, and are preferably groups in the substituent group E. 21 and R 22 are bonded to each other to form a single bond. 8 and R 12 In one aspect of the present invention, at least one of R 8 , R 10 and R 12 is a substituent. 8 ~R 12 The substituent of X is preferably an unsubstituted alkyl group. 1 is a boron atom, R 13 and R 17 In one aspect of the present invention, at least one of X is a substituent, and preferably both are substituents. 1 is a boron atom, R 13 , R 15 and R 17 is a substituent. X 1 is a boron atom, R 13 ~R 17 The substituent of X is preferably an unsubstituted alkyl group. 2 is a boron atom, R 22 and R 26 In one aspect of the present invention, at least one of X is a substituent, and preferably both are substituents. 2 is a boron atom, R 22 , R 24 and R 26 is a substituent. X 2 is a boron atom, R 22 ~R 26 The substituent of is preferably an unsubstituted alkyl group.

[0068] A 1 and A 2 is a hydrogen atom, a deuterium atom, or a substituent. As the substituent, a group selected from any one of the groups A to E of substituents described below can be used. A 1 and A 2A preferred substituent that can be adopted by is an acceptor group. The acceptor group is a group having a positive Hammett σp value. Here, the "Hammett σp value" was proposed by L.P. Hammett, and quantifies the influence of a substituent on the reaction rate or equilibrium of a para-substituted benzene derivative. Specifically, the following equation holds between the substituent in a para-substituted benzene derivative and the reaction rate constant or equilibrium constant: log(k / k0) = ρσp or log(K / K0) = ρσp where k is the rate constant for a benzene derivative having no substituent, k is the rate constant for a benzene derivative substituted with a substituent, K is the equilibrium constant for a benzene derivative having no substituent, K is the equilibrium constant for a benzene derivative substituted with a substituent, and ρ is a reaction constant determined by the type and conditions of the reaction. For an explanation of the "Hammett σp value" in the present invention and the numerical values ​​of each substituent, please refer to the description of the σp value in Hansch, C. et al., Chem. Rev., 91, 165-195 (1991). A 1 and A 2The acceptor group that can be adopted is more preferably a group having a Hammett σp value of greater than 0.2. Examples of groups having a Hammett σp value of greater than 0.2 include a cyano group, an aryl group substituted with at least a cyano group, a group containing a fluorine atom, and a substituted or unsubstituted heteroaryl group containing a nitrogen atom as a ring skeleton-constituting atom. The aryl group substituted with at least a cyano group may be substituted with a substituent other than a cyano group (e.g., an alkyl group or an aryl group), or may be an aryl group substituted only with a cyano group. The aryl group substituted with at least a cyano group is preferably a phenyl group substituted with at least a cyano group. The number of cyano groups substituted is preferably 1 or 2, for example, it may be 1 or 2. Examples of groups containing a fluorine atom include a fluorine atom, a fluorinated alkyl group, and an aryl group substituted with at least a fluorine atom or a fluorinated alkyl group. The fluorinated alkyl group is preferably a perfluoroalkyl group, preferably having 1 to 6 carbon atoms, more preferably 1 to 3 carbon atoms. Furthermore, a heteroaryl group containing a nitrogen atom as a ring skeleton-constituting atom may be a single ring or a fused ring in which two or more rings are fused. In the case of a fused ring, the number of rings after fusion is preferably 2 to 6, and can be selected from 2 to 4, or can be 2. Specific examples of rings constituting a heteroaryl group include a pyridine ring, a pyrimidine ring, a pyrazine ring, a triazine ring, a quinoline ring, an isoquinoline ring, a quinazoline ring, a quinoxaline ring, and a naphthyridine ring other than a quinazoline ring or a quinoxaline ring. The ring constituting the heteroaryl group may be substituted with a deuterium atom or a substituent, and examples of the substituent include a group consisting of one or more groups selected from the group consisting of an alkyl group, an aryl group, and a heteroaryl group. A 1 and A 2 Among the possible acceptor groups, a cyano group is particularly preferred. In one aspect of the present invention, A 1 and A 2 are each independently a hydrogen atom or a deuterium atom. 1and A 2 In one embodiment of the present invention, at least one of A is an acceptor group. 1 and A 2 In one embodiment of the present invention, at least one of A is an acceptor group. 1 and A 2 In one embodiment of the present invention, both of A 1 and A 2 In one embodiment of the present invention, both of A 1 and A 2 is a cyano group. 1 and A 2 is a halogen atom, for example a bromine atom.

[0069] Specific examples of acceptor groups that can be used in the present invention are shown below. However, the acceptor groups that can be used in the present invention should not be construed as being limited by the following specific examples. Methyl groups are omitted in this specification. For example, A15 indicates a group containing two 4-methylphenyl groups. Furthermore, "D" represents a deuterium atom. * indicates a bonding position. [ka] [ka]

[0070] In addition, X 1 is a nitrogen atom, and R 7 and R 8 are bonded via a nitrogen atom to form a six-membered ring, and R 21 and R 22 are bonded via a nitrogen atom to form a six-membered ring, and R 17 and R 18 When they are bonded to each other to form a single bond, R 1 ~R 6 At least one of R is a substituted or unsubstituted aryl group, or R 1 and R 2 , R 2 and R 3, R 3 and R 4 , R 4 and R 5 , R 5 and R 6 are bonded to each other to form an aromatic ring (a substituted or unsubstituted benzene ring which may be fused) or a heteroaromatic ring (preferably a furan ring of a substituted or unsubstituted benzofuran which may be fused, or a thiophene ring of a substituted or unsubstituted benzothiophene which may be fused).

[0071] X in general formula (16) 1 When X in general formula (16) is a nitrogen atom, the compound of the present invention has the following skeleton (16a): 2 When is a nitrogen atom, the compounds of the present invention have the following skeleton (16b): [ka]

[0072] Each hydrogen atom in the skeletons (16a) and (16b) may be substituted with a deuterium atom or a substituent. Alternatively, the adjacent hydrogen atom may be substituted with a linking group to form a cyclic structure. For details, see the corresponding R in general formula (16). 1 ~R 26 , A 1 , A 2 can be referred to. Examples include compounds in which the phenyl groups bonded to the boron atoms in skeletons (16a) and (16b) are all substituted with mesityl groups, 2,6-diisopropylphenyl groups, or 2,4,6-triisopropylphenyl groups. In one embodiment of the present invention, each hydrogen atom in skeletons (16a) and (16b) is substituted with a linking group together with the adjacent hydrogen atom, so that a cyclic structure is not formed.

[0073] A preferred group of compounds having the skeleton (16a) includes compounds represented by the following general formula (16a): General formula (16a) [ka]

[0074] In the general formula (16a), Ar 1 ~Ar 4 R each independently represents a substituted or unsubstituted aryl group, or a substituted or unsubstituted heteroaryl group. 41 and R 42 Each of m1 and m2 independently represents an integer of 0 to 5, each of n1 and n3 independently represents an integer of 0 to 4, and each of n2 and n4 independently represents an integer of 0 to 3. A 1 , A 2 each independently represents a hydrogen atom, a deuterium atom, or a substituent. In one embodiment of the present invention, n1 to n4 each independently represent an integer of 0 to 2. In a preferred embodiment of the present invention, at least one of n1 to n4 is 1 or greater, preferably at least one of n1 and n2 is 1 or greater, and at least one of n3 and n4 is 1 or greater. In one embodiment of the present invention, n1 and n3 each independently represent 1 or 2, and n2 and n4 are 0. In one embodiment of the present invention, n2 and n4 each independently represent 1 or 2, and n1 and n3 are 0. In one embodiment of the present invention, n1 to n4 each independently represent 1 or 2. In one embodiment of the present invention, n1 and n3 are equal, and n2 and n4 are equal. In one embodiment of the present invention, n1 and n3 are 1, and n2 and n4 are 0. In one embodiment of the present invention, n1 and n3 are 0, and n2 and n4 are 1. In one embodiment of the present invention, n1 to n4 are all 1. Ar 1 ~Ar 4 The bonding position of Ar may be at least one of the 3- and 6-positions, at least one of the 2- and 7-positions, at least one of the 1- and 8-positions, or at least one of the 4- and 5-positions of the carbazole ring. 1 ~Ar 4The bonding positions of may be both the 3- and 6-positions, both the 2- and 7-positions, both the 1- and 8-positions, or both the 4- and 5-positions of the carbazole ring. For example, at least one of the 3- and 6-positions can be preferably selected, or both the 3- and 6-positions can be more preferably selected. In a preferred embodiment of the present invention, Ar 1 ~Ar 4 In a preferred embodiment of the present invention, all of Ar 1 ~Ar 4 are each independently a substituted or unsubstituted aryl group, more preferably a substituted or unsubstituted phenyl group or naphthyl group, and even more preferably a substituted or unsubstituted phenyl group. Examples of the substituent include a group selected from any of the substituent groups A to E described below, but an unsubstituted phenyl group is also preferred. Ar 1 ~Ar 4 Preferred specific examples of the group include a phenyl group, an o-biphenyl group, an m-biphenyl group, a p-biphenyl group, and a terphenyl group. In one embodiment of the present invention, m1 and m2 are each independently 0. In one embodiment of the present invention, m1 and m2 are each independently an integer of 1 to 5. In one embodiment of the present invention, m1 and m2 are equal. In one embodiment of the present invention, R 41 and R 42 is an alkyl group having 1 to 6 carbon atoms, and can be selected from alkyl groups having 1 to 3 carbon atoms, for example, or a methyl group. The substitution positions of the alkyl group, with the carbon atom bonded to the boron atom being the 1st position, can be exemplified by the 2nd position only, the 3rd position only, the 4th position only, the 3rd and 5th positions, the 2nd and 4th positions, the 2nd and 6th positions, and the 2nd, 4th and 6th positions, preferably at least the 2nd position, and more preferably at least the 2nd and 6th positions. A 1 and A 2 For the explanation and preferred range of , please refer to the corresponding description of general formula (16).

[0075] Specific examples of the compound represented by general formula (16a) are given below. The compounds of general formula (16a) that can be used in the present invention are not to be construed as being limited by the following specific examples. [ka] [ka] [ka] [ka] [ka] [ka] [ka]

[0076] A preferred group of compounds having the skeleton (16b) includes compounds represented by the following general formula (16b). General formula (16b) [ka]

[0077] In the general formula (16b), Ar 5 ~Ar 8 R each independently represents a substituted or unsubstituted aryl group, or a substituted or unsubstituted heteroaryl group. 43 and R 44 each independently represents a substituted or unsubstituted alkyl group. m3 and m4 each independently represents an integer of 0 to 5, n6 and n8 each independently represents an integer of 0 to 3, and n5 and n7 each independently represents an integer of 0 to 4. A 1 , A 2 each independently represents a hydrogen atom, a deuterium atom, or a substituent. 5 ~Ar8 , R 43 and R 44 , m3 and m4, n5~n8, A 1 , A 2 For details, see Ar in general formula (16a). 1 ~Ar 4 , R 41 and R 42 , m1 and m2, n1 to n4, A 1 , A 2 The following description can be referred to.

[0078] Specific examples of the compound represented by general formula (16b) are listed below. The compounds of general formula (16b) that can be used in the present invention are not to be construed as being limited by the following specific examples. [ka]

[0079] R in general formula (16) 7 and R 8 When these are bonded together to form N-Ph, the compounds of the present invention are 1 When is a nitrogen atom, for example, the following skeleton (17a) is obtained, and X 2 When is a nitrogen atom, for example, it has the following skeleton (17b): Ph is a phenyl group. [ka]

[0080] Each hydrogen atom in the skeletons (17a) and (17b) may be substituted with a deuterium atom or a substituent. Alternatively, the hydrogen atoms may be substituted with a linking group together with the adjacent hydrogen atoms to form a cyclic structure. For details, see the corresponding R in general formula (16). 1 ~R 26 , A 1 , A 2can be referred to. At least one hydrogen atom of the benzene ring constituting the carbazole partial structure contained in the skeleton (17a) is substituted with a substituted or unsubstituted aryl group. In one embodiment of the present invention, each hydrogen atom in the skeletons (17a) and (17b) is substituted with a linking group together with the adjacent hydrogen atom, so that a cyclic structure is not formed.

[0081] A preferred group of compounds having the skeleton (17a) includes compounds represented by the following general formula (17a): General formula (17a) [ka]

[0082] In the general formula (17a), Ar 9 ~Ar 14 Each of n9, n11, n12, and n14 independently represents an integer of 0 to 4, and n10 and n13 independently represent an integer of 0 to 2. However, at least one of n9, n10, n12, and n13 is 1 or greater. A 1 , A 2 each independently represents a hydrogen atom, a deuterium atom, or a substituent. In one embodiment of the present invention, n9 to n14 each independently represent an integer of 0 to 2. In one embodiment of the present invention, at least one of n9 to n14 is 1 or greater; for example, n9 and n12 can be 1 or greater, or n10 and n13 can be 1 or greater. In a preferred embodiment of the present invention, at least one of n9, n10, n12, and n13 is 1 or greater. In one embodiment of the present invention, n9 and n12 each independently represent 1 or 2, and n10, n11, n13, and n14 each represent 0. In one embodiment of the present invention, n10 and n13 each independently represent 1 or 2, and n9, n11, n12, and n14 each represent 0. In one embodiment of the present invention, n9 and n12 each independently represent 1 or 2, and n10 and n13 each independently represent 1 or 2, and n11 and n14 each represent 0. In one embodiment of the present invention, n9 to n14 are all 1. Ar9 ~Ar 14 The bonding positions of Ar may be the 3- and 6-positions of the carbazole ring or other positions. 9 ~Ar 14 are all the same group. 9 ~Ar 14 For preferred groups, Ar 1 ~Ar 4 Reference can be made to the corresponding description in A. 1 and A 2 For the explanation and preferred range of , please refer to the corresponding description of general formula (16).

[0083] Specific examples of the compound represented by general formula (17a) are listed below. The compounds of general formula (17a) that can be used in the present invention are not to be construed as being limited by the following specific examples. [ka]

[0084] A preferred group of compounds having the skeleton (17b) includes compounds represented by the following general formula (17b). General formula (17b) [ka]

[0085] In the general formula (17b), Ar 15 ~Ar 20 each independently represents a substituted or unsubstituted aryl group or a substituted or unsubstituted heteroaryl group. n15, n17, n18, and n20 each independently represent an integer of 0 to 4, and n16 and n19 each independently represent an integer of 0 to 2. A 1 , A 2 each independently represents a hydrogen atom, a deuterium atom, or a substituent. 15 ~Ar 20 , n15~n20, A 1 , A 2 For details, see Ar in general formula (17a).9 ~Ar 14 , n9~n14, A 1 , A 2 The following descriptions can be referred to in order.

[0086] Specific examples of the compound represented by general formula (17b) are listed below. The compounds of general formula (17b) that can be used in the present invention are not to be construed as being limited by the following specific examples. [ka]

[0087] R in general formula (16) 7 and R 8 When these bond to each other to form a single bond, the compounds of the present invention are 1 When is a nitrogen atom, for example, the following skeleton (18a) is obtained, and X 2 When is a nitrogen atom, for example, it has the following skeleton (18b). [ka]

[0088] Each hydrogen atom in the skeletons (18a) and (18b) may be substituted with a deuterium atom or a substituent. Alternatively, the hydrogen atoms may be substituted with a linking group together with the adjacent hydrogen atoms to form a cyclic structure. For details, see the corresponding R in general formula (16). 1 ~R 26 , A 1 , A 2 In one embodiment of the present invention, each hydrogen atom in the skeletons (18a) and (18b) is substituted with a linking group together with the adjacent hydrogen atom to form a ring structure.

[0089] A preferred group of compounds having the skeleton (18a) includes compounds represented by the following general formula (18a): General formula (18a) [ka]

[0090] In the general formula (18a), Ar 21 ~Ar 26 Each of n21, n23, n24, and n26 independently represents an integer of 0 to 4, and each of n22 and n25 independently represents an integer of 0 to 2. A 1 , A 2 each independently represents a hydrogen atom, a deuterium atom, or a substituent. 21 ~Ar 25 For details of n21 to n25, see Ar in general formula (17a). 9 ~Ar 14 , n9~n14, A 1 , A 2 The following description can be referred to.

[0091] Specific examples of the compound represented by general formula (18a) are given below. The compounds of general formula (18a) that can be used in the present invention are not to be construed as being limited by the following specific examples. [ka]

[0092] A preferred group of compounds having the skeleton (18b) includes compounds represented by the following general formula (18b). General formula (18b) [ka]

[0093] In the general formula (18b), Ar 27 ~Ar 32 Each of n27, n29, n30, and n32 independently represents an integer of 0 to 4, and each of n28 and n31 independently represents an integer of 0 to 2. A 1 , A 2 each independently represents a hydrogen atom, a deuterium atom, or a substituent.27 ~Ar 32 , n27~n32, A 1 , A 2 For details, see Ar in general formula (17b). 15 ~Ar 20 , n15~n20, A 1 , A 2 The following descriptions can be referred to in order.

[0094] Specific examples of the compound represented by general formula (18b) are listed below. The compounds of general formula (18b) that can be used in the present invention are not to be construed as being limited by the following specific examples. [ka]

[0095] In a preferred embodiment of the present invention, a compound in which another ring is fused to the two benzene rings constituting the carbazole moiety present in general formula (16) is selected. Among these, a compound in which a benzofuran ring is fused, a compound in which a benzothiophene ring is fused, or a compound in which a benzene ring is fused can be particularly preferably selected. Below, these ring-fused compounds will be described with specific examples.

[0096] Preferred examples of such compounds include compounds in which a benzofuran ring or a benzothiophene ring is fused to the benzene ring that is not directly bonded to a boron atom, out of the two benzene rings constituting the carbazole moiety in general formula (16). Examples of such compounds include compounds having the following skeleton (19a) and compounds having the following skeleton (19b). [ka]

[0097] In skeletons (19a) and (19b), Y 1 ~Y 4 are each independently two hydrogen atoms, a single bond, or N(R 27) The two hydrogen atoms here indicate that the two benzene rings bonded to the boron atom are not linked to each other. Y 1 and Y 2 is the same as Y 3 and Y 4 are preferably the same, but may be different. 1 ~Y 4 is a single bond. In one aspect of the present invention, Y 1 ~Y 4 is N(R 27 ) is R 27 represents a hydrogen atom, a deuterium atom or a substituent. Z 1 ~Z 4 each independently represents an oxygen atom or a sulfur atom. 1 and Z 2 are the same, and Z 3 and Z 4 are preferably the same, but may be different. 1 ~Z 4 is an oxygen atom. In this case, the furan ring of benzofuran is fused to the benzene ring constituting the carbazole moiety in (19a) and (19b). The orientation of the fused furan ring is not limited. In one embodiment of the present invention, Z 1 ~Z 4 is a sulfur atom. In this case, the thiophene ring of the benzothiophene is fused to the benzene ring that constitutes the carbazole moiety in (19a) and (19b). The orientation of the fused thiophene ring is not restricted. Each hydrogen atom in the skeletons (19a) and (19b) may be substituted with a deuterium atom or a substituent. Alternatively, the hydrogen atoms may be substituted with a linking group together with the adjacent hydrogen atoms to form a cyclic structure. For details, see the corresponding R in general formula (16). 1 ~R 26 , A 1 , A 2 In one embodiment of the present invention, each hydrogen atom in the skeletons (19a) and (19b) is substituted with a linking group together with the adjacent hydrogen atom to form a ring structure.

[0098] A preferred group of compounds having the skeleton (19a) includes compounds represented by the following general formula (19a). X in the specific examples represents an oxygen atom or a sulfur atom, and compounds in which X is an oxygen atom and compounds in which X is a sulfur atom are both considered to be disclosed. X in the specific examples of compounds represented by other general formulas below also has the same meaning. General formula (19a) [ka]

[0099] In the general formula (19a), Ar 51 and Ar 52 R each independently represents a substituted or unsubstituted aryl group, or a substituted or unsubstituted heteroaryl group. 51 and R 52 Each of m51 and m52 independently represents an integer of 0 to 4. Each of n51 and n52 independently represents an integer of 0 to 2. Y 1 ~Y 4 are each independently two hydrogen atoms, a single bond, or N(R 27 ) represents R 27 represents a hydrogen atom, a deuterium atom or a substituent. 1 ~Z 4 A each independently represents an oxygen atom or a sulfur atom. 1 , A 2 each independently represents a hydrogen atom, a deuterium atom, or a substituent. In one embodiment of the present invention, n51 and n52 are the same number. For example, n51 and n52 may be 0, or n51 and n52 may be 1. In one embodiment of the present invention, m51 and m52 are the same number. In one embodiment of the present invention, m51 and m52 are integers of 0 to 3. For example, m51 and m52 may be 0, m51 and m52 may be 1, m51 and m52 may be 2, or m51 and m52 may be 3. Ar 51 , Ar 52 , R 51 , R 52 , A 1 , A2 The preferred groups are Ar 1 ~Ar 4 , R 41 ~R 42 , A 1 , A 2 Reference can be made to the corresponding description in

[0100] Specific examples of the compound represented by general formula (19a) are listed below. The compounds of general formula (19a) that can be used in the present invention are not limited to the specific examples below. Regarding specific examples containing X, compounds in which all Xs in the molecule are oxygen atoms and compounds in which all Xs in the molecule are sulfur atoms are considered to be disclosed. Compounds in which some of the Xs in the molecule are oxygen atoms and the rest are sulfur atoms can also be used. [ka] [ka] [ka] [ka] [ka] [ka] [ka] [ka]

[0101] A preferred group of compounds having the skeleton (19b) includes compounds represented by the following general formula (19b). General formula (19b) [ka]

[0102] In the general formula (19b), Ar 53 and Ar 54 R each independently represents a substituted or unsubstituted aryl group, or a substituted or unsubstituted heteroaryl group. 53 and R 54 Each of m53 and m54 independently represents an integer of 0 to 4. Each of n53 and n54 independently represents an integer of 0 to 2. Y 3 and Y 4 are each independently two hydrogen atoms, a single bond, or N(R 27 ) represents R 27 represents a hydrogen atom, a deuterium atom or a substituent. 3 and Z 4 A each independently represents an oxygen atom or a sulfur atom. 1 , A 2 each independently represents a hydrogen atom, a deuterium atom, or a substituent. 53 , Ar 54 , R 53 , R 54 , m53, m54, n53, n54, A 1 , A 2 For details, see Ar in general formula (19a). 51 , Ar 52 , R 51 , R 52 , m51, m52, n51, n52, A 1 , A 2 The following description can be referred to.

[0103] Specific examples of the compound represented by general formula (19b) are listed below. The compounds of general formula (19b) that can be used in the present invention are not limited to the specific examples below. Regarding specific examples containing X, compounds in which all Xs in the molecule are oxygen atoms and compounds in which all Xs in the molecule are sulfur atoms are considered to be disclosed. Compounds in which some of the Xs in the molecule are oxygen atoms and the rest are sulfur atoms can also be used. [ka]

[0104] Preferred examples of such compounds include compounds in which a benzofuran ring or a benzothiophene ring is fused to the benzene ring directly bonded to a boron atom among the two benzene rings constituting the carbazole moiety in general formula (16). Examples of such compounds include a compound having the following skeleton (20a) and a compound having the following skeleton (20b). [ka]

[0105] In skeletons (20a) and (20b), Y 5 ~Y 8 are each independently two hydrogen atoms, a single bond, or N(R 27 ) represents Z. 5 ~Z 8 Each of Y independently represents an oxygen atom or a sulfur atom. 5 ~Y 8 , Z 5 ~Z 8 For details of the skeletons (19a) and (19b), please refer to the corresponding descriptions of the skeletons (19a) and (19b). In one embodiment of the present invention, each hydrogen atom in the skeletons (20a) and (20b) is substituted with a linking group together with the adjacent hydrogen atom to form a ring structure.

[0106] A preferred group of compounds having the skeleton (20a) includes compounds represented by the following general formula (20a): General formula (20a) [ka]

[0107] In the general formula (20a), Ar 55 and Ar 56 R each independently represents a substituted or unsubstituted aryl group, or a substituted or unsubstituted heteroaryl group. 55 and R 56Each of m55 and m56 independently represents an integer of 0 to 4. Each of n55 and n56 independently represents an integer of 0 to 4. Y 5 and Y 6 are each independently two hydrogen atoms, a single bond, or N(R 27 ) represents R 27 represents a hydrogen atom, a deuterium atom or a substituent. 5 and Z 6 A each independently represents an oxygen atom or a sulfur atom. 1 , A 2 each independently represents a hydrogen atom, a deuterium atom, or a substituent. In one embodiment of the present invention, n55 and n56 are integers of 0 to 2. For example, n55 and n56 may be 0, or n55 and n56 may be 1. In one embodiment of the present invention, m51 and m52 are the same number. For details of m55 and m56, the description of m51 and m52 in general formula (19a) can be referred to. Ar 55 , Ar 56 , R 55 , R 56 , A 1 , A 2 The preferred groups are Ar 1 , Ar 3 , R 41 , R 42 , A 1 , A 2 Reference can be made to the corresponding description in

[0108] Specific examples of the compound represented by general formula (20a) are listed below. The compounds of general formula (20a) that can be used in the present invention are not limited to the specific examples below. Regarding specific examples containing X, compounds in which all Xs in the molecule are oxygen atoms and compounds in which all Xs in the molecule are sulfur atoms are considered to be disclosed. Compounds in which some of the Xs in the molecule are oxygen atoms and the rest are sulfur atoms can also be used. [ka] [ka] [ka] [ka] [ka]

[0109] A preferred group of compounds having the skeleton (20b) includes compounds represented by the following general formula (20b). General formula (20b) [ka]

[0110] In the general formula (20b), Ar 57 and Ar 58 R each independently represents a substituted or unsubstituted aryl group, or a substituted or unsubstituted heteroaryl group. 57 and R 58 Each of m57 and m58 independently represents an integer of 0 to 4. Each of n57 and n58 independently represents an integer of 0 to 4. Y 7 and Y 8 are each independently two hydrogen atoms, a single bond, or N(R 27 ) represents R 27 represents a hydrogen atom, a deuterium atom or a substituent. 7 and Z 8 A each independently represents an oxygen atom or a sulfur atom. 1 , A 2 each independently represents a hydrogen atom, a deuterium atom, or a substituent. 57 , Ar 58 , R 57 , R 58 , m57, m58, n57, n58, A 1 , A 2 For details, see Ar in general formula (20a). 55 , Ar 56 , R 55 , R56 , m55, m56, n55, n56, A 1 , A 2 The following description can be referred to.

[0111] Specific examples of the compound represented by general formula (20b) are listed below. The compounds of general formula (20b) that can be used in the present invention are not limited to the specific examples below. Regarding specific examples containing X, compounds in which all Xs in the molecule are oxygen atoms and compounds in which all Xs in the molecule are sulfur atoms are considered to be disclosed. Compounds in which some of the Xs in the molecule are oxygen atoms and the rest are sulfur atoms can also be used. [ka]

[0112] Preferred examples of such compounds include compounds in which a benzofuran ring or a benzothiophene ring is fused to both of the two benzene rings constituting the carbazole moiety in general formula (16). Examples of such compounds include a compound having the following skeleton (21a) and a compound having the following skeleton (21b). [ka]

[0113] In skeletons (21a) and (21b), Y 9 ~Y 12 are each independently two hydrogen atoms, a single bond, or N(R 27 ) represents Z. 9 ~Z 16 each independently represents an oxygen atom or a sulfur atom. 9 ~Z 16 are preferably the same, but may be different. 9 ~Z 16 is an oxygen atom. In one embodiment of the present invention, Z 9 ~Z 16 is a sulfur atom. Y 9 ~Y 12For details of the skeletons (19a) and (19b), please refer to the corresponding descriptions of the skeletons (19a) and (19b). In one embodiment of the present invention, each hydrogen atom in the skeletons (21a) and (21b) is substituted with a linking group together with the adjacent hydrogen atom to form no cyclic structure.

[0114] A preferred group of compounds having the skeleton (21a) includes compounds represented by the following general formula (21a): General formula (21a) [ka]

[0115] In general formula (21a), R 59 and R 60 Each of m59 and m60 independently represents an integer of 0 to 4. Y 9 and Y 10 are each independently two hydrogen atoms, a single bond, or N(R 27 ) represents R 27 represents a hydrogen atom, a deuterium atom or a substituent. 9 ~Z 12 A each independently represents an oxygen atom or a sulfur atom. 1 , A 2 R each independently represents a hydrogen atom, a deuterium atom, or a substituent. 59 , R 60 , m59, m60, Z 9 ~Z 12 , A 1 , A 2 For details, see R in general formula (20a). 55 , R 56 , m55, m56, A 1 , A 2 and Z in skeleton (21a) 9 ~Z 12 The following description can be referred to.

[0116] Specific examples of the compound represented by general formula (21a) are listed below. The compounds of general formula (21a) that can be used in the present invention are not limited to the specific examples below. Regarding specific examples containing X, compounds in which all Xs in the molecule are oxygen atoms and compounds in which all Xs in the molecule are sulfur atoms are considered to be disclosed. Compounds in which some of the Xs in the molecule are oxygen atoms and the rest are sulfur atoms can also be used. [ka] [ka] [ka] [ka] [ka]

[0117] A preferred group of compounds having the skeleton (21b) includes compounds represented by the following general formula (21b). General formula (21b) [ka]

[0118] In general formula (21b), R 61 and R 62 Each of m61 and m60 independently represents an integer of 0 to 4. Y 11 and Y 12 are each independently two hydrogen atoms, a single bond, or N(R 27 ) represents R 27 represents a hydrogen atom, a deuterium atom or a substituent. 13 ~Z 16 A each independently represents an oxygen atom or a sulfur atom. 1 , A 2R each independently represents a hydrogen atom, a deuterium atom, or a substituent. 61 , R 62 , m61, m62, Z 13 ~Z 16 , A 1 , A 2 For details, see R in general formula (21a). 59 , R 60 , m59, m60, A 1 , A 2 and Z in skeleton (21b) 13 ~Z 16 The following description can be referred to.

[0119] Specific examples of the compound represented by general formula (21b) are listed below. The compounds of general formula (21b) that can be used in the present invention are not limited to the specific examples below. Regarding specific examples containing X, compounds in which all Xs in the molecule are oxygen atoms and compounds in which all Xs in the molecule are sulfur atoms are considered to be disclosed. Compounds in which some of the Xs in the molecule are oxygen atoms and the rest are sulfur atoms can also be used. [ka] [ka] [ka]

[0120] Preferred examples of such compounds include compounds in which a benzene ring is fused to the benzene ring to which the boron atom is not directly bonded, out of the two benzene rings constituting the carbazole moiety in general formula (16). Examples of such compounds include compounds having the following skeleton (22a) and compounds having the following skeleton (22b). [ka]

[0121] In skeletons (22a) and (22b), Y21 ~Y 24 are each independently two hydrogen atoms, a single bond, or N(R 27 ) Y 21 ~Y 24 For details, see Y in skeletons (19a) and (19b). 1 ~Y 4 In one embodiment of the present invention, each hydrogen atom in the skeletons (22a) and (22b) is substituted with a linking group together with the adjacent hydrogen atom to form a ring structure.

[0122] A preferred group of compounds having the skeleton (22a) includes compounds represented by the following general formula (22a): General formula (22a) [ka]

[0123] In the general formula (22a), Ar 71 ~Ar 74 each independently represents a substituted or unsubstituted aryl group or a substituted or unsubstituted heteroaryl group. n71 and n73 each independently represents an integer of 0 to 2. n72 and n74 each independently represents an integer of 0 to 4. Y 21 and Y 22 are each independently two hydrogen atoms, a single bond, or N(R 27 ) represents R 27 represents a hydrogen atom, a deuterium atom or a substituent. 1 , A 2 each independently represents a hydrogen atom, a deuterium atom, or a substituent. In one embodiment of the present invention, n71 to n74 are integers of 0 to 2. In one embodiment of the present invention, n71 and n73 are the same number, and n72 and n74 are the same number. n71 to n74 may be the same number. For example, n71 to n74 may be 0. All of n71 to n74 may be 1. Also, for example, , n71 and n73 may be 0, and n72 and n74 may be 1. Ar 71 ~Ar 74 , A 1, A 2 The preferred groups are Ar 1 ~Ar 4 , A 1 , A 2 Reference can be made to the corresponding description in

[0124] Specific examples of the compound represented by general formula (22a) are given below. The compounds of general formula (22a) that can be used in the present invention are not to be construed as being limited by the following specific examples. [ka]

[0125] A preferred group of compounds having the skeleton (22b) includes compounds represented by the following general formula (22b). General formula (22b) [ka]

[0126] In the general formula (22b), Ar 75 ~Ar 78 each independently represents a substituted or unsubstituted aryl group or a substituted or unsubstituted heteroaryl group. n75 and n77 each independently represent an integer of 0 to 2. n76 and n78 each independently represent an integer of 0 to 4. Y 23 and Y 24 are each independently two hydrogen atoms, a single bond, or N(R 27 ) represents R 27 represents a hydrogen atom, a deuterium atom, or a substituent. For a detailed explanation of n75 to n78, the descriptions of n71 to n74 in general formula (22a) can be referred to in order. Ar 75 ~Ar 78 The preferred groups are Ar 1 ~Ar 4 Reference can be made to the corresponding description in

[0127] Specific examples of the compound represented by general formula (22b) are listed below. The compounds of general formula (22b) that can be used in the present invention are not to be construed as being limited by the following specific examples. [ka]

[0128] Preferred examples of such compounds include compounds in which a benzene ring is fused to the benzene ring directly bonded to a boron atom, out of the two benzene rings constituting the carbazole moiety in general formula (16). Examples of such compounds include compounds having the following skeleton (23a) and compounds having the following skeleton (23b). [ka]

[0129] In skeletons (23a) and (23b), Y 25 ~Y 28 are each independently two hydrogen atoms, a single bond, or N(R 27 ) Y 25 ~Y 28 For details of the skeletons (19a) and (19b), please refer to the corresponding descriptions of the skeletons (19a) and (19b). In one embodiment of the present invention, each hydrogen atom in the skeletons (23a) and (23b) is substituted with a linking group together with the adjacent hydrogen atom to form no cyclic structure.

[0130] A preferred group of compounds having the skeleton (23a) includes compounds represented by the following general formula (23a): General formula (23a) [ka]

[0131] In the general formula (23a), Ar 79 and Ar 80 R each independently represents a substituted or unsubstituted aryl group, or a substituted or unsubstituted heteroaryl group.71 and R 72 Each of m71 and m72 independently represents an integer of 0 to 4. Each of n79 and n80 independently represents an integer of 0 to 4. Y 25 and Y 26 are each independently two hydrogen atoms, a single bond, or N(R 27 ) represents R 27 represents a hydrogen atom, a deuterium atom or a substituent. 1 , A 2 each independently represents a hydrogen atom, a deuterium atom, or a substituent. In one embodiment of the present invention, n79 and n80 are integers of 0 to 2. In one embodiment of the present invention, n79 and n80 are the same number, and for example, both may be 0 or both may be 1. In one embodiment of the present invention, m71 and m72 are integers of 0 to 2. In one embodiment of the present invention, m71 and m72 are the same number, and for example, both may be 0 or both may be 1. Ar 79 , Ar 80 , R 71 , R 72 , A 1 , A 2 The preferred groups are Ar 1 , Ar 3 , R 41 , R 42 , A 1 , A 2 Reference can be made to the corresponding description in

[0132] Specific examples of the compound represented by general formula (23a) are given below. The compounds of general formula (23a) that can be used in the present invention are not to be construed as being limited by the following specific examples. [ka]

[0133] A preferred group of compounds having the skeleton (23b) includes compounds represented by the following general formula (23b). General formula (23b) [ka]

[0134] In the general formula (23b), Ar 81 and Ar 82 R each independently represents a substituted or unsubstituted aryl group, or a substituted or unsubstituted heteroaryl group. 73 and R 74 Each of m73 and m74 independently represents an integer of 0 to 4. Each of n81 and n82 independently represents an integer of 0 to 4. Y 27 and Y 28 are each independently two hydrogen atoms, a single bond, or N(R 27 ) represents R 27 represents a hydrogen atom, a deuterium atom or a substituent. 1 , A 2 each independently represents a hydrogen atom, a deuterium atom, or a substituent. For a detailed explanation of m73, m74, n81, and n82, please refer to the descriptions of m71, m72, n79, and n80 in general formula (23a). 81 , Ar 82 , R 73 , R 74 , A 1 , A 2 The preferred groups are Ar 1 , Ar 3 , R 41 , R 42 , A 1 , A 2 Reference can be made to the corresponding description in

[0135] Specific examples of the compound represented by general formula (23b) are listed below. The compounds of general formula (23b) that can be used in the present invention are not to be construed as being limited by the following specific examples. [ka]

[0136] Preferred examples of such compounds include compounds in which a benzene ring is fused to both of the two benzene rings constituting the carbazole moiety in general formula (16). Examples of such compounds include a compound having the following skeleton (24a) and a compound having the following skeleton (24b). [ka]

[0137] In skeletons (24a) and (24b), Y 29 ~Y 32 are each independently two hydrogen atoms, a single bond, or N(R 27 ) Y 29 ~Y 32 For details of the skeletons (19a) and (19b), please refer to the corresponding descriptions of the skeletons (19a) and (19b). In one embodiment of the present invention, each hydrogen atom in the skeletons (24a) and (24b) is substituted with a linking group together with the adjacent hydrogen atom to form a ring structure.

[0138] A preferred group of compounds having the skeleton (24a) includes compounds represented by the following general formula (24a): General formula (24a) [ka]

[0139] In general formula (24a), R 75 and R 76 Each of m75 and m76 independently represents an integer of 0 to 4. Y 29 and Y 30 are each independently two hydrogen atoms, a single bond, or N(R 27 ) represents R 27 represents a hydrogen atom, a deuterium atom or a substituent. 1 , A 2 R each independently represents a hydrogen atom, a deuterium atom, or a substituent. 75 , R 76 , m75, m76, A 1, A 2 For details, see R in general formula (23a). 71 , R 72 , m71, m72, A 1 , A 2 The following description can be referred to.

[0140] Specific examples of the compound represented by general formula (24a) are given below. The compounds of general formula (24a) that can be used in the present invention are not to be construed as being limited by the following specific examples. [ka] [ka]

[0141] A preferred group of compounds having the skeleton (24b) includes compounds represented by the following general formula (24b). General formula (24b) [ka]

[0142] In general formula (24b), R 77 and R 78 Each of m77 and m78 independently represents an integer of 0 to 4. Y 31 and Y 32 are each independently two hydrogen atoms, a single bond, or N(R 27 ) represents R 27 represents a hydrogen atom, a deuterium atom or a substituent. 1 , A 2 R each independently represents a hydrogen atom, a deuterium atom, or a substituent. 77 , R 78 , m77, m78, A 1 , A 2 For details, see R in general formula (23a). 71 , R 72 , m71, m72, A 1 , A 2The following description can be referred to.

[0143] Specific examples of the compound represented by general formula (24b) are given below. The compounds of general formula (24b) that can be used in the present invention are not to be construed as being limited by the following specific examples. [ka]

[0144] Compounds represented by general formula (16) that contain four or more carbazole moieties in the molecule are also preferred. Examples of such compounds include compounds having the following skeleton (25). Skeleton (25) [ka]

[0145] Each hydrogen atom in the skeleton (25) may be substituted with a deuterium atom or a substituent. Alternatively, the hydrogen atom may be substituted with a linking group together with the adjacent hydrogen atom to form a cyclic structure. For details, see the corresponding R in general formula (16). 1 ~R 26 , A 1 , A 2 can be referred to. At least one hydrogen atom of the benzene ring constituting the carbazole partial structure contained in the skeleton (25) is substituted with a substituted or unsubstituted aryl group. In one embodiment of the present invention, each hydrogen atom in the skeleton (25) is substituted with a linking group together with the adjacent hydrogen atom, so that a cyclic structure is not formed.

[0146] A preferred group of compounds having the skeleton (25) includes compounds represented by the following general formula (25): General formula (25) [ka]

[0147] In the general formula (25), Ar 91 ~Ar 94 Each independently represents a substituted or unsubstituted aryl group, or a substituted or unsubstituted heteroaryl group. n91 and n93 each independently represent an integer of 0 to 4, and n92 and n94 each independently represent an integer of 0 to 3. The α ring, β ring, γ ring, and δ ring may be substituted, and at least one ring is substituted with a substituted or unsubstituted aryl group, or is fused with an optionally substituted benzene ring, or is fused with a furan ring of a substituted or unsubstituted benzofuran or a thiophene ring of a substituted or unsubstituted thiophene. A 1 , A 2 each independently represents a hydrogen atom, a deuterium atom, or a substituent. In one embodiment of the present invention, n91 to n94 are integers of 0 to 2. In one embodiment of the present invention, n91 and n93 are the same number, and n92 and n94 are the same number. n91 to n94 may all be the same number, for example, all may be 0 or all may be 1. Ar 91 ~Ar 94 The preferred groups are Ar 1 ~Ar 4Reference can be made to the corresponding description in the above. In one embodiment of the present invention, the α-ring and the γ-ring have the same substituent or the same fused structure, and the β-ring and the δ-ring have the same substituent or the same fused structure. In one embodiment of the present invention, the β-ring and the δ-ring are both substituted with a substituted or unsubstituted aryl group, are fused with an optionally substituted benzene ring, or are fused with a furan ring of a substituted or unsubstituted benzofuran or a thiophene ring of a substituted or unsubstituted thiophene. In one embodiment of the present invention, the α-ring and the γ-ring are both substituted with a substituted or unsubstituted aryl group, are fused with an optionally substituted benzene ring, or are fused with a furan ring of a substituted or unsubstituted benzofuran or a thiophene ring of a substituted or unsubstituted thiophene. In one embodiment of the present invention, all of the α-ring, the β-ring, the γ-ring, and the δ-ring are substituted with a substituted or unsubstituted aryl group, are fused with an optionally substituted benzene ring, or are fused with a furan ring of a substituted or unsubstituted benzofuran or a thiophene ring of a substituted or unsubstituted thiophene. A 1 and A 2 For the explanation and preferred range of , please refer to the corresponding description of general formula (16).

[0148] Specific examples of the compound represented by general formula (25) are given below. The compounds of general formula (25) that can be used in the present invention are not to be construed as being limited by the following specific examples. [ka] [ka] [ka]

[0149] In one embodiment of the present invention, the above skeletons (16a) to (25) are skeletons to which no other ring is fused. In another embodiment of the present invention, the above skeletons (16a) to (25) are skeletons to which other rings may be fused. The other rings referred to here are those represented by the above R 1 and R2 , R 2 and R 3 , R 3 and R 4 , R 4 and R 5 , R 5 and R 6 , R 6 and R 7 , R 8 and R 9 , R 9 and R 10 , R 10 and R 11 , R 11 and R 12 , R 13 and R 14 , R 14 and R 15 , R 15 and R 16 , R 16 and R 17 , R 18 and R 19 , R 19 and R 20 , R 20 and R 21 , R 22 and R 23 , R 23 and R 24 , R 24 and R 25 , R 25 and R 26 The description of the cyclic structure formed by bonding together can be referred to.

[0150] In one embodiment of the present invention, A in general formula (16) 1 and A 2 is an acceptor group. For example, A 1 and A 2 The acceptor group is at position (16a) and examples thereof include compounds having any of the skeletons (16a) to (25). For details and specific examples of the acceptor group, see A in the above general formula (16). 1 and A 2 The explanation and specific examples of the acceptor group can be referred to. In the following, A 1 and A 2 Specific examples of compounds in which A is an acceptor group are as follows:1 and A 2 The compounds in which A is an acceptor group are not to be construed as being limited by the following specific examples. 1 and A 2 have a structure in which both are "A", and the structure of each compound is specified by individually specifying the "A". [ka] [ka] [ka] [ka] [ka] [ka] [ka] [ka] [ka]

[0151] In one embodiment of the present invention, a compound having a rotationally symmetric structure is selected as the compound represented by general formula (16). In another embodiment of the present invention, a compound having an axisymmetric structure is selected as the compound represented by general formula (16). In another embodiment of the present invention, a compound having an asymmetric structure is selected as the compound represented by general formula (16). Specific examples of compounds having an asymmetric skeleton are listed below. Compounds having an asymmetric skeleton or compounds having an asymmetric structure that can be used in the present invention are not limited to the specific examples below. Regarding specific examples containing X, compounds in which all Xs in the molecule are oxygen atoms and compounds in which all Xs in the molecule are sulfur atoms are considered to be disclosed. Compounds in which some of the Xs in the molecule are oxygen atoms and the rest are sulfur atoms can also be used. [ka] [ka]

[0152] In a particularly preferred embodiment of the present invention, a compound in which at least one of a tert-butyl group and a phenyl group is introduced into the following skeleton (26a) or skeleton (26b) is selected as the third organic compound. [ka]

[0153] Specific examples of compounds in which at least one of a tert-butyl group and a phenyl group is introduced into the skeleton (26a) or the skeleton (26b) are given below. The compounds of general formula (16) that can be used in the present invention are not limited to the following specific examples. [ka] [ka] [ka] [ka] [ka]

[0154] When an organic layer containing the compound represented by general formula (16) is intended to be formed by vapor deposition, the molecular weight of the compound represented by general formula (16) is preferably 1500 or less, more preferably 1200 or less, even more preferably 1000 or less, and even more preferably 900 or less. The lower limit of the molecular weight is the molecular weight of the smallest compound in the group of compounds represented by general formula (16). It is preferably 624 or more. The compound represented by general formula (16) may be formed into a film by a coating method regardless of its molecular weight. By using the coating method, it is possible to form a film even from a compound with a relatively large molecular weight. The compound represented by general formula (16) has the advantage of being easily soluble in organic solvents. Therefore, the compound represented by general formula (16) is easy to apply the coating method to, and is also easy to purify to increase its purity.

[0155] It is also conceivable that the present invention can be applied to use a compound containing a plurality of structures represented by general formula (16) in the molecule as a light-emitting material. For example, a polymerizable group may be pre-existed in the structure represented by general formula (16), and the polymer obtained by polymerizing the polymerizable group may be used as a light-emitting material. Specifically, a monomer containing a polymerizable functional group in one of the structures represented by general formula (16) may be prepared, and this may be polymerized alone or copolymerized with other monomers to obtain a polymer having repeating units, and the polymer may be used as a light-emitting material. Alternatively, compounds represented by general formula (16) may be coupled to obtain dimers or trimers, which may be used as light-emitting materials.

[0156] Examples of polymers having a repeating unit containing a structure represented by general formula (16) include polymers containing a structure represented by the following general formula: [ka]

[0157] In the above general formula, Q represents a group containing a structure represented by general formula (16), and L 1 and L 2 represents a linking group. The number of carbon atoms in the linking group is preferably 0 to 20, more preferably 1 to 15, and even more preferably 2 to 10. The linking group is -X 11 -L 11 Preferably, X has a structure represented by the formula: 11 represents an oxygen atom or a sulfur atom, and is preferably an oxygen atom. 11 represents a linking group, which is preferably a substituted or unsubstituted alkylene group or a substituted or unsubstituted arylene group, and more preferably a substituted or unsubstituted alkylene group having 1 to 10 carbon atoms or a substituted or unsubstituted phenylene group. R 101 , R 102 , R 103 and R 104 each independently represents a substituent, preferably a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 6 carbon atoms, or a halogen atom, more preferably an unsubstituted alkyl group having 1 to 3 carbon atoms, an unsubstituted alkoxy group having 1 to 3 carbon atoms, a fluorine atom, or a chlorine atom, and still more preferably an unsubstituted alkyl group having 1 to 3 carbon atoms, or an unsubstituted alkoxy group having 1 to 3 carbon atoms. L 1 and L 2 The linking group represented by the following formula can be bonded to any position of the structure represented by general formula (16) constituting Q. Two or more linking groups may be bonded to one Q to form a crosslinked structure or a network structure.

[0158] Specific structural examples of the repeating unit include structures represented by the following formulas. [ka]

[0159] A polymer having repeating units containing these formulae can be synthesized by introducing a hydroxy group into any position of the structure represented by general formula (16), reacting the hydroxy group as a linker with the following compound to introduce a polymerizable group, and polymerizing the polymerizable group. [ka]

[0160] A polymer containing a structure represented by general formula (16) in its molecule may be a polymer consisting only of repeating units having the structure represented by general formula (16), or may be a polymer containing repeating units having other structures. The repeating units having the structure represented by general formula (16) contained in the polymer may be of a single type, or may be of two or more types. Examples of repeating units not having the structure represented by general formula (16) include those derived from monomers used in ordinary copolymerization. For example, repeating units derived from monomers having an ethylenically unsaturated bond, such as ethylene and styrene, can be mentioned.

[0161] The compound represented by general formula (16) preferably does not contain a metal atom. The metal atom here does not include a boron atom. For example, the compound represented by general formula (16) may be a compound consisting of atoms selected from the group consisting of carbon, hydrogen, deuterium, nitrogen, oxygen, sulfur, and boron. For example, the compound represented by general formula (16) may be a compound consisting of atoms selected from the group consisting of carbon, hydrogen, deuterium, nitrogen, oxygen, and boron. For example, the compound represented by general formula (16) may be a compound consisting of atoms selected from the group consisting of carbon, hydrogen, deuterium, nitrogen, sulfur, and boron. For example, the compound represented by general formula (16) may be a compound consisting of atoms selected from the group consisting of carbon, hydrogen, deuterium, nitrogen, and boron. For example, the compound represented by general formula (16) may be a compound consisting of atoms selected from the group consisting of carbon, hydrogen, deuterium, nitrogen, and boron.

[0162] In this specification, the term "alkyl group" may be linear, branched, or cyclic. It may also contain two or more of the linear, cyclic, and branched moieties. The number of carbon atoms in the alkyl group may be, for example, 1 or more, 2 or more, or 4 or more. The number of carbon atoms may be 30 or less, 20 or less, 10 or less, 6 or less, or 4 or less. Specific examples of the alkyl group include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, an n-pentyl group, an isopentyl group, an n-hexyl group, an isohexyl group, a 2-ethylhexyl group, an n-heptyl group, an isoheptyl group, an n-octyl group, an isooctyl group, an n-nonyl group, an isononyl group, an n-decanyl group, an isodecanyl group, a cyclopentyl group, a cyclohexyl group, and a cycloheptyl group. The alkyl group may be further substituted with an aryl group. The "alkenyl group" may be linear, branched, or cyclic. It may also contain two or more of the linear, cyclic, and branched moieties. The alkenyl group may have, for example, two or more carbon atoms, or four or more carbon atoms. It may also have 30 or less, 20 or less, 10 or less, 6 or less, or 4 or less carbon atoms. Specific examples of the alkenyl group include ethenyl, n-propenyl, isopropenyl, n-butenyl, isobutenyl, n-pentenyl, isopentenyl, n-hexenyl, isohexenyl, and 2-ethylhexenyl. The substituted alkenyl group may be further substituted with a substituent. The "aryl group" and "heteroaryl group" may be a single ring or a fused ring in which two or more rings are fused. In the case of a fused ring, the number of fused rings is preferably 2 to 6, and can be selected from, for example, 2 to 4. Specific examples of the ring include a benzene ring, a pyridine ring, a pyrimidine ring, a triazine ring, a naphthalene ring, an anthracene ring, a phenanthrene ring, a triphenylene ring, a quinoline ring, a pyrazine ring, a quinoxaline ring, and a naphthyridine ring, and these may be fused rings. Specific examples of the aryl group or heteroaryl group include a phenyl group, a 1-naphthyl group, a 2-naphthyl group, a 1-anthracenyl group, a 2-anthracenyl group, a 9-anthracenyl group, a 2-pyridyl group, a 3-pyridyl group, and a 4-pyridyl group. The number of atoms constituting the ring skeleton of the aryl group is preferably 6 to 40, more preferably 6 to 20, and may be selected within a range of 6 to 14, or may be selected within a range of 6 to 10. The number of atoms constituting the ring skeleton of the heteroaryl group is preferably 4 to 40, more preferably 5 to 20, and may be selected from the range of 5 to 14, or may be selected from the range of 5 to 10. The terms "arylene group" and "heteroaryl group" can be understood by changing the valence of the aryl group and heteroaryl group from 1 to 2.

[0163] In the present specification, "substituent group A" refers to a hydroxyl group, a halogen atom (for example, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom), an alkyl group (for example, having 1 to 40 carbon atoms), an alkoxy group (for example, having 1 to 40 carbon atoms), an alkylthio group (for example, having 1 to 40 carbon atoms), an aryl group (for example, having 6 to 30 carbon atoms), an aryloxy group (for example, having 6 to 30 carbon atoms), an arylthio group (for example, having 6 to 30 carbon atoms), a heteroaryl group (for example, having 5 to 30 ring skeleton atoms), a heteroaryloxy group (for example, having 5 to 30 ring skeleton atoms), a heteroaryl group, ... It means one group or a combination of two or more groups selected from the group consisting of heteroarylthio groups (for example, having 5 to 30 atoms constituting the ring skeleton), acyl groups (for example, having 1 to 40 carbon atoms), alkenyl groups (for example, having 1 to 40 carbon atoms), alkynyl groups (for example, having 1 to 40 carbon atoms), alkoxycarbonyl groups (for example, having 1 to 40 carbon atoms), aryloxycarbonyl groups (for example, having 1 to 40 carbon atoms), heteroaryloxycarbonyl groups (for example, having 1 to 40 carbon atoms), silyl groups (for example, trialkylsilyl groups having 1 to 40 carbon atoms), and nitro groups. In this specification, the term "substituent group B" refers to one group or a combination of two or more groups selected from the group consisting of alkyl groups (e.g., having 1 to 40 carbon atoms), alkoxy groups (e.g., having 1 to 40 carbon atoms), aryl groups (e.g., having 6 to 30 carbon atoms), aryloxy groups (e.g., having 6 to 30 carbon atoms), heteroaryl groups (e.g., having 5 to 30 ring skeleton atoms), heteroaryloxy groups (e.g., having 5 to 30 ring skeleton atoms), and diarylaminoamino groups (e.g., having 0 to 20 carbon atoms). In this specification, the term "substituent group C" refers to one group or a combination of two or more groups selected from the group consisting of alkyl groups (e.g., having 1 to 20 carbon atoms), aryl groups (e.g., having 6 to 22 carbon atoms), heteroaryl groups (e.g., having 5 to 20 ring skeleton atoms), and diarylamino groups (e.g., having 12 to 20 carbon atoms). In this specification, the term "substituent group D" refers to one group or a combination of two or more groups selected from the group consisting of alkyl groups (e.g., having 1 to 20 carbon atoms), aryl groups (e.g., having 6 to 22 carbon atoms), and heteroaryl groups (e.g., having 5 to 20 ring skeleton atoms). In this specification, the term "substituent group E" refers to one group or a combination of two or more groups selected from the group consisting of alkyl groups (for example, having 1 to 20 carbon atoms) and aryl groups (for example, having 6 to 22 carbon atoms). In the present specification, when a "substituent" or "substituted or unsubstituted" is used, the substituent may be selected from, for example, Substituent Group A, Substituent Group B, Substituent Group C, Substituent Group D, or Substituent Group E.

[0164] The following compounds can also be used as the third organic compound. In a preferred embodiment of the present invention, a compound represented by the following general formula (27) is used as the third organic compound. General formula (27) [ka]

[0165] In the above general formula (27), Ar 1 ~Ar 3 are each independently an aryl ring or a heteroaryl ring, and at least one hydrogen atom in these rings may be substituted, or the rings may be fused. When a hydrogen atom is substituted, it is preferably substituted with one group or a combination of two or more groups selected from the group consisting of a deuterium atom, an aryl group, a heteroaryl group, and an alkyl group. When the rings are fused, it is preferably fused with a benzene ring or a heteroaromatic ring (e.g., a furan ring, a thiophene ring, a pyrrole ring, etc.). R a and R a Each R' independently represents a substituent, and is preferably one or a combination of two or more groups selected from the group consisting of a deuterium atom, an aryl group, a heteroaryl group, and an alkyl group. a and Ar 1 , Ar 1 and Ar 2 , Ar 2 and R a ', R a ' and Ar 3, Ar 3 and R a may be bonded to each other to form a cyclic structure.

[0166] The compound represented by the general formula (27) preferably contains at least one carbazole structure. For example, one of the benzene rings constituting the carbazole structure is Ar 1 and one of the benzene rings constituting the carbazole structure may be represented by Ar 2 and one of the benzene rings constituting the carbazole structure may be represented by Ar 3 The ring may be represented by Ar 1 ~Ar 3 A carbazolyl group may be bonded to one or more of the following. For example, Ar 3 A substituted or unsubstituted carbazol-9-yl group may be bonded to the ring represented by the formula:

[0167] Ar 1 ~Ar 3 may have a fused aromatic ring structure such as anthracene, pyrene, or perylene bonded thereto. 1 ~Ar 3 The ring represented by R may be one of the rings constituting a fused aromatic ring structure. a and R a At least one of the groups may be a group having a fused aromatic ring structure.

[0168] A compound may contain a plurality of skeletons represented by general formula (27). For example, skeletons represented by general formula (27) may be bonded to each other via a single bond or a linking group. Furthermore, the skeleton represented by general formula (27) may further include a structure exhibiting a multiple resonance effect in which benzene rings are linked to each other via a boron atom, a nitrogen atom, an oxygen atom, or a sulfur atom.

[0169] In a preferred embodiment of the present invention, a compound containing a BODIPY (4,4-difluoro-4-bora-3a,4a-diaza-s-indacene) structure is used as the third organic compound, for example, a compound represented by the following general formula (28): General formula (28) [ka]

[0170] In general formula (28), R 1 ~R 7 R are each independently a hydrogen atom, a deuterium atom, or a substituent. 1 ~R 7 At least one of the above is preferably a group represented by the following general formula (29). General formula (29) [ka] In general formula (29), R 11 ~R 15 each independently represents a hydrogen atom, a deuterium atom or a substituent, and * represents the bonding position. The group represented by general formula (29) is R 1 ~R 7 In a preferred embodiment of the present invention, R 1 ~R 7 In a preferred embodiment of the present invention, at least one of R 1 , R 3 , R 5 , R 7 is a group represented by general formula (29). In a preferred embodiment of the present invention, R 1 , R 3 , R 4 , R 5 , R 7 In a preferred embodiment of the present invention, only R 1 , R 3 , R 4, R 5 , R 7 is a group represented by general formula (29), and R 2 and R 4 is a hydrogen atom, a deuterium atom, an unsubstituted alkyl group (e.g., having 1 to 10 carbon atoms), or an unsubstituted aryl group (e.g., having 6 to 14 carbon atoms). 1 ~R 7 All of these are groups represented by general formula (29). In a preferred embodiment of the present invention, R 1 and R 7 In a preferred embodiment of the present invention, R 3 and R 5 In a preferred embodiment of the present invention, R 2 and R 6 In a preferred embodiment of the present invention, R 1 and R 7 are identical and R 3 and R 5 are the same and R 1 and R 3 In a preferred embodiment of the present invention, R 1 , R 3 , R 5 , R 7 In a preferred embodiment of the present invention, R 1 and R 4 and R 7 are identical and R 3 or R 5 In a preferred embodiment of the present invention, R 3 and R 4 and R 5 are identical and R 1 or R 7 In a preferred embodiment of the present invention, R 1 , R 3 , R 5 , R 7 are all R 4 is different.

[0171] R in general formula (29) 11 ~R 15 As the substituent that can be adopted by R, for example, the groups in the above-mentioned Substituent Group A can be selected. 11 ~R15 The substituents that may be taken by are preferably one group or a combination of two or more groups selected from the group consisting of substituted or unsubstituted alkyl groups (e.g., having 1 to 40 carbon atoms), substituted or unsubstituted alkoxy groups (e.g., having 1 to 40 carbon atoms), substituted or unsubstituted aryl groups (e.g., having 6 to 30 carbon atoms), substituted or unsubstituted aryloxy groups (e.g., having 6 to 30 carbon atoms), and substituted or unsubstituted amino groups (e.g., having 0 to 20 carbon atoms) (hereinafter these groups are referred to as "groups in substituent group C"). Among the substituents in substituent group C, it is preferable to select an unsubstituted alkyl group having 1 to 20 carbon atoms, an unsubstituted alkoxy group having 1 to 20 carbon atoms, an unsubstituted aryl group having 6 to 14 carbon atoms, an aryloxy group having 6 to 14 carbon atoms, or an unsubstituted diarylamino group having 5 to 20 ring atoms (hereinafter these groups are referred to as "groups in substituent group D"). The substituted amino group referred to here is preferably a disubstituted amino group, and the two substituents on the amino group are preferably each independently a substituted or unsubstituted aryl group, a substituted or unsubstituted heteroaryl group, or a substituted or unsubstituted alkyl group, and a substituted or unsubstituted aryl group (a diarylamino group) is particularly preferred. The substituents that can be taken by the two aryl groups of the diarylamino group can be selected from the groups in the above-mentioned Substituent Group A, the above-mentioned Substituent Group B, or the above-mentioned Substituent Group C. The two aryl groups of the diarylamino group may be bonded to each other via a single bond or a linking group, and the linking group referred to here is R 33 and R 34 The explanation of the linking group in the above can be referred to. A specific example of the diarylamino group is a substituted or unsubstituted carbazol-9-yl group. Examples of the substituted or unsubstituted carbazol-9-yl group include L in the above general formula (6). 11 is a single bond. In a preferred embodiment of the present invention, R in general formula (29) 13 is the only substituent, and R 11 , R 12 , R 14 , R 15In a preferred embodiment of the present invention, R in general formula (29) is a hydrogen atom. 11 is the only substituent, and R 12 , R 13 , R 14 , R 15 In a preferred embodiment of the present invention, R in general formula (29) is a hydrogen atom. 11 and R 13 is the only substituent, and R 12 , R 14 , R 15 is a hydrogen atom. R in general formula (28) 1 ~R 7 Among them, R of general formula (29) 11 ~R 15 may also include a group in which all of R are hydrogen atoms (i.e., a phenyl group). For example, R 2 , R 4 , R 6 may be a phenyl group.

[0172] In general formula (28), R 8 and R 9 are each independently one group or a combination of two or more groups selected from the group consisting of a hydrogen atom, a deuterium atom, a halogen atom, an alkyl group (e.g., having 1 to 40 carbon atoms), an alkoxy group (e.g., having 1 to 40 carbon atoms), an aryloxy group (e.g., having 6 to 30 carbon atoms), and a cyano group. In a preferred embodiment of the present invention, R 8 and R 9 In a preferred embodiment of the present invention, R 8 and R 9 is a halogen atom, and is particularly preferably a fluorine atom.

[0173] In one embodiment of the present invention, R in general formula (28) 1 ~R 9 The total number of substituted or unsubstituted alkoxy groups, substituted or unsubstituted aryloxy groups, and substituted or unsubstituted amino groups present in R in general formula (28) is preferably three or more, and for example, a compound having three or four groups can be used. 1 ~R7 The total number of substituted or unsubstituted alkoxy groups, substituted or unsubstituted aryloxy groups, and substituted or unsubstituted amino groups present in R is preferably three or more, and for example, a compound having three or four groups may be used. 8 and R 9 In general formula (28), R may not have an alkoxy group, an aryloxy group, or an amino group. 1 , R 3 , R 4 , R 5 , R 7 The total number of substituted or unsubstituted alkoxy groups, substituted or unsubstituted aryloxy groups, and substituted or unsubstituted amino groups present in R is preferably three or more, and for example, a compound having three or four groups may be used. 2 , R 6 , R 8 , R 9 In a preferred embodiment of the present invention, R has three or more substituted or unsubstituted alkoxy groups. In a preferred embodiment of the present invention, R has four or more substituted or unsubstituted alkoxy groups. In a preferred embodiment of the present invention, R has one or more substituted or unsubstituted alkoxy groups and two or more substituted or unsubstituted aryloxy groups. In a preferred embodiment of the present invention, R has two or more substituted or unsubstituted alkoxy groups and one or more substituted or unsubstituted amino groups. In a preferred embodiment of the present invention, R 1 , R 4 , R 7 In a preferred embodiment of the present invention, R 1 , R 4 , R 7 Each of these groups contains a substituted or unsubstituted alkoxy group.

[0174] In one embodiment of the present invention, R in general formula (28) 1 ~R 9The total number of substituents with Hammett's σp values ​​of less than -0.2 is three or more. Examples of substituents with Hammett's σp values ​​of less than -0.2 include a methoxy group (-0.27), an ethoxy group (-0.24), an n-propoxy group (-0.25), an isopropoxy group (-0.45), and an n-butoxy group (-0.32). On the other hand, fluorine atoms (0.06), methyl groups (-0.17), ethyl groups (-0.15), tert-butyl groups (-0.20), an n-hexyl group (-0.15), and a cyclohexyl group (-0.15) are not substituents with Hammett's σp values ​​of less than -0.2. In one embodiment of the present invention, R in general formula (28) 1 ~R 9 It is possible to adopt a compound having three or four substituents with a Hammett's σp value of less than −0.2. More preferably, R 1 ~R 7 Preferably, the number of substituents present in R having a Hammett's σp value of less than -0.2 is three or more, and for example, a compound having three or four substituents can be used. 8 and R 9 In general formula (28), R may not have a substituent with a Hammett's σp value of less than -0.2. 1 , R 3 , R 4 , R 5 , R 7 The number of substituents present in R having a Hammett's σp value of less than -0.2 is preferably three or more, and for example, a compound having three or four substituents can be used. 2 , R 6 , R 8 , R 9 In a preferred embodiment of the present invention, R may be free of any substituent having a Hammett's σp value of less than −0.2. 1 , R 4 , R 7 Each of these has a substituent with a Hammett σp value of less than -0.2.

[0175] Preferred compounds that can be used as the third organic compound are listed below: In the structural formulas of the following exemplary compounds, t-Bu represents a tertiary butyl group. [ka] [ka] [ka] [ka]

[0176] Derivatives of the above-exemplified compounds include compounds in which at least one hydrogen atom is substituted with a deuterium atom, an alkyl group, an aryl group, a heteroaryl group, or a diarylamino group.

[0177] In addition, the compounds described in paragraphs 0220 to 0239 of WO2015 / 022974, paragraphs 0066 and 0117 of WO2019 / 111971, and paragraphs 0196 to 0255 of WO2021 / 015177 can also be particularly preferably used as the third organic compound of the present invention.

[0178] (light-emitting layer) The light-emitting layer of the organic electroluminescent device of the present invention comprises a first organic compound, a second organic compound, and a third organic compound that satisfy conditions (a) and (b). In a preferred embodiment of the present invention, the second organic compound is compound T132, and the third organic compound is a compound selected from the group consisting of compounds F101 to F128. The light-emitting layer may be configured so as not to contain, in addition to the first organic compound, the second organic compound, and the third organic compound, any compounds that transfer charge or energy or any metal elements other than boron. The light-emitting layer may also be configured solely from compounds consisting of atoms selected from the group consisting of carbon, hydrogen, deuterium, nitrogen, boron, oxygen, and sulfur atoms. For example, the light-emitting layer may be configured solely from compounds consisting of atoms selected from the group consisting of carbon, hydrogen, deuterium, nitrogen, boron, and oxygen atoms. For example, the light-emitting layer may be configured solely from compounds consisting of atoms selected from the group consisting of carbon, hydrogen, deuterium, nitrogen, boron, and oxygen atoms. For example, the light-emitting layer may be composed solely of compounds consisting of atoms selected from the group consisting of carbon, hydrogen, deuterium, nitrogen, and boron atoms. For example, the light-emitting layer may be composed solely of compounds consisting of atoms selected from the group consisting of carbon, hydrogen, deuterium, nitrogen, oxygen, and sulfur atoms. For example, the light-emitting layer may be composed solely of compounds consisting of atoms selected from the group consisting of carbon, hydrogen, deuterium, and nitrogen atoms. The light-emitting layer may include a first organic compound consisting of atoms selected from the group consisting of carbon, hydrogen, nitrogen, and oxygen atoms, a second organic compound consisting of atoms selected from the group consisting of carbon, hydrogen, deuterium, nitrogen, oxygen, and sulfur atoms, and a third organic compound consisting of atoms selected from the group consisting of carbon, hydrogen, deuterium, nitrogen, boron, oxygen, and sulfur atoms.The light-emitting layer may also include a first organic compound composed of atoms selected from the group consisting of carbon atoms, hydrogen atoms, nitrogen atoms, and oxygen atoms, a second organic compound composed of atoms selected from the group consisting of carbon atoms, hydrogen atoms, deuterium atoms, and nitrogen atoms, and a third organic compound composed of atoms selected from the group consisting of carbon atoms, hydrogen atoms, deuterium atoms, nitrogen atoms, and boron atoms. The light-emitting layer may be formed by co-evaporation of the first organic compound, the second organic compound, and the third organic compound, or by coating a solution containing the first organic compound, the second organic compound, and the third organic compound. When forming the light-emitting layer by co-evaporation, two or more of the first organic compound, the second organic compound, and the third organic compound may be mixed in advance and placed in a crucible or the like to form a vapor deposition source, and the light-emitting layer may be formed by co-evaporation using the vapor deposition source. For example, the first organic compound and the second organic compound may be mixed in advance to form a single vapor deposition source, and the light-emitting layer may be formed by co-evaporation using the vapor deposition source and the vapor deposition source of the third organic compound.

[0179] Each component of the organic electroluminescence element and each layer other than the light-emitting layer will be described below.

[0180] Base material: In some embodiments, the organic electroluminescent device of the present invention is supported by a substrate, and the substrate is not particularly limited and may be any material commonly used in organic electroluminescent devices, such as glass, transparent plastic, quartz, and silicon.

[0181] anode: In some embodiments, the anode of the organic electroluminescent device is made of a metal, an alloy, a conductive compound, or a combination thereof. In some embodiments, the metal, alloy, or conductive compound has a high work function (4 eV or greater). In some embodiments, the metal is Au. In some embodiments, the conductive transparent material is selected from CuI, indium tin oxide (ITO), SnO, and ZnO. In some embodiments, an amorphous material capable of forming a transparent conductive film, such as In2O3-ZnO, is used. In some embodiments, the anode is a thin film. In some embodiments, the thin film is formed by evaporation or sputtering. In some embodiments, the film is patterned by a photolithography method. In some embodiments, if the pattern does not need to be highly precise (e.g., greater than about 100 μm), the pattern may be formed using a mask with a shape suitable for evaporation or sputtering of the electrode material. In some embodiments, when a coating material, such as an organic conductive compound, can be applied, a wet film formation method, such as a printing method or a coating method, is used. In some embodiments, the anode has a transmittance of greater than 10% when emitted light passes through it, and the anode has a sheet resistance of several hundred ohms per unit area or less. In some embodiments, the anode has a thickness of 10 to 1,000 nm. In some embodiments, the anode has a thickness of 10 to 200 nm. In some embodiments, the thickness of the anode varies depending on the material used.

[0182] cathode: In some embodiments, the cathode is made of an electrode material such as a metal with a low work function (4 eV or less) (referred to as an electron-injecting metal), alloy, conductive compound, or a combination thereof. In some embodiments, the electrode material is selected from sodium, sodium-potassium alloy, magnesium, lithium, magnesium-copper mixture, magnesium-silver mixture, magnesium-aluminum mixture, magnesium-indium mixture, aluminum-aluminum oxide (Al2O3) mixture, indium, lithium-aluminum mixture, and rare earth elements. In some embodiments, a mixture of an electron-injecting metal and a second metal, which is a stable metal having a higher work function than the electron-injecting metal, is used. In some embodiments, the mixture is selected from magnesium-silver mixture, magnesium-aluminum mixture, magnesium-indium mixture, aluminum-aluminum oxide (Al2O3) mixture, lithium-aluminum mixture, and aluminum. In some embodiments, the mixture improves electron-injecting properties and oxidation resistance. In some embodiments, the cathode is fabricated by forming the electrode material as a thin film by evaporation or sputtering. In some embodiments, the cathode has a sheet resistance of several hundred ohms per unit area or less. In some embodiments, the cathode has a thickness of 10 nm to 5 μm. In some embodiments, the cathode has a thickness of 50 to 200 nm. In some embodiments, one of the anode and cathode of the organic electroluminescent device is transparent or semitransparent to transmit emitted light. In some embodiments, a transparent or semitransparent electroluminescent device improves light radiance. In some embodiments, the cathode is formed from a conductive, transparent material as described above for the anode, thereby forming a transparent or semi-transparent cathode. In some embodiments, a device includes an anode and a cathode, both of which are transparent or semi-transparent.

[0183] Injection layer: An injection layer is a layer between an electrode and an organic layer. In some embodiments, the injection layer reduces driving voltage and enhances light radiance. In some embodiments, the injection layer comprises a hole injection layer and an electron injection layer. The injection layer can be disposed between the anode and the emissive layer or the hole transport layer, and between the cathode and the emissive layer or the electron transport layer. In some embodiments, an injection layer is present. In some embodiments, an injection layer is not present. Preferred examples of compounds that can be used as hole injection materials are listed below.

[0184] [ka]

[0185] Next, preferred examples of compounds that can be used as the electron injection material will be listed. [ka]

[0186] Barrier layer: A blocking layer is a layer that can prevent charges (electrons or holes) and / or excitons present in the light-emitting layer from diffusing outside the light-emitting layer. In some embodiments, an electron blocking layer is present between the light-emitting layer and the hole transport layer and prevents electrons from passing through the light-emitting layer to the hole transport layer. In some embodiments, a hole blocking layer is present between the light-emitting layer and the electron transport layer and prevents holes from passing through the light-emitting layer to the electron transport layer. In some embodiments, a blocking layer prevents excitons from diffusing outside the light-emitting layer. In some embodiments, the electron blocking layer and the hole blocking layer constitute an exciton blocking layer. As used herein, the terms "electron blocking layer" or "exciton blocking layer" include layers that have both the functionality of an electron blocking layer and an exciton blocking layer.

[0187] Hole blocking layer: The hole blocking layer functions as an electron transport layer. In some embodiments, the hole blocking layer prevents holes from reaching the electron transport layer during electron transport. In some embodiments, the hole blocking layer increases the probability of recombination of electrons and holes in the light-emitting layer. The materials used for the hole blocking layer can be the same materials as those described above for the electron transport layer. Preferred examples of compounds that can be used in the hole blocking layer are listed below.

[0188] [ka]

[0189] Electron barrier layer: The electron blocking layer transports holes. In some embodiments, during hole transport, the electron blocking layer prevents electrons from reaching the hole transport layer. In some embodiments, the electron blocking layer increases the probability of recombination of electrons and holes in the light-emitting layer. The materials used for the electron blocking layer can be the same materials as those described above for the hole transport layer. Specific examples of preferred compounds that can be used as electron blocking materials are listed below.

[0190] [ka]

[0191] Exciton blocking layer: The exciton blocking layer prevents excitons generated through the recombination of holes and electrons in the emissive layer from diffusing to the charge transport layer. In some embodiments, the exciton blocking layer enables effective confinement of excitons in the emissive layer. In some embodiments, the light emission efficiency of the device is improved. In some embodiments, the exciton blocking layer is adjacent to the emissive layer on either the anode side or the cathode side, and on both sides. In some embodiments, when the exciton blocking layer is present on the anode side, it may be present between the hole transport layer and the emissive layer and adjacent to the emissive layer. In some embodiments, when the exciton blocking layer is present on the cathode side, it may be present between the emissive layer and the cathode and adjacent to the emissive layer. In some embodiments, a hole injection layer, an electron blocking layer, or a similar layer is present between the anode and the exciton blocking layer adjacent to the emissive layer on the anode side. In some embodiments, a hole injection layer, an electron blocking layer, a hole blocking layer, or a similar layer is present between the cathode and the exciton blocking layer adjacent to the emissive layer on the cathode side. In some embodiments, the exciton blocking layer comprises an excited singlet energy and an excited triplet energy, at least one of which is higher than the excited singlet energy and excited triplet energy, respectively, of the light-emitting material.

[0192] Hole transport layer: The hole transport layer comprises a hole transport material. In some embodiments, the hole transport layer is a single layer. In some embodiments, the hole transport layer has multiple layers. In some embodiments, the hole transport material has one of hole injection or transport properties and electron blocking properties. In some embodiments, the hole transport material is an organic material. In some embodiments, the hole transport material is an inorganic material. Examples of known hole transport materials that can be used in the present invention include, but are not limited to, triazole derivatives, oxadiazole derivatives, imidazole derivatives, carbazole derivatives, indolocarbazole derivatives, polyarylalkane derivatives, pyrazoline derivatives, pyrazolone derivatives, phenylenediamine derivatives, allylamine derivatives, amino-substituted chalcone derivatives, oxazole derivatives, styrylanthracene derivatives, fluorenone derivatives, hydrazone derivatives, stilbene derivatives, silazane derivatives, aniline copolymers, and conductive polymer oligomers (especially thiophene oligomers), or combinations thereof. In some embodiments, the hole transport material is selected from porphyrin compounds, aromatic tertiary amine compounds, and styrylamine compounds. In some embodiments, the hole transport material is an aromatic tertiary amine compound. Specific examples of preferred compounds that can be used as hole transport materials are listed below.

[0193] [ka]

[0194] Electron transport layer: The electron transport layer comprises an electron transport material. In some embodiments, the electron transport layer is a single layer. In some embodiments, the electron transport layer has multiple layers. In some embodiments, the electron transport material only needs to transport electrons injected from the cathode to the light-emitting layer. In some embodiments, the electron transport material also functions as a hole-blocking material. Examples of electron transport layers that can be used in the present invention include, but are not limited to, nitro-substituted fluorene derivatives, diphenylquinone derivatives, thiopyran dioxide derivatives, carbodiimides, fluorenylidenemethane derivatives, anthraquinodimethanes, anthrone derivatives, oxadiazole derivatives, azole derivatives, azine derivatives, or combinations thereof, or polymers thereof. In some embodiments, the electron transport material is a thiadiazole derivative or a quinoxaline derivative. In some embodiments, the electron transport material is a polymer material. Specific examples of preferred compounds that can be used as electron transport materials are listed below.

[0195] [ka]

[0196] Furthermore, examples of compounds that can be added to each organic layer are given below, which may be added as a stabilizing material, for example.

[0197] [ka]

[0198] Although specific examples of preferred materials that can be used in organic electroluminescence devices have been given, the materials that can be used in the present invention should not be construed as being limited to the following exemplary compounds. Furthermore, even compounds exemplified as materials having specific functions can be diverted to be used as materials having other functions.

[0199] device: In some embodiments, the light-emitting layer is incorporated into a device, including, but not limited to, an OLED bulb, an OLED lamp, a television display, a computer monitor, a mobile phone, and a tablet. In some embodiments, the electronic device comprises an OLED having an anode, a cathode, and at least one organic layer comprising an emissive layer between the anode and the cathode. In some embodiments, the compositions described herein can be incorporated into various photosensitive or photoactivated devices, such as OLEDs or optoelectronic devices. In some embodiments, the compositions can be useful for facilitating charge or energy transfer within devices and / or as hole transport materials, such as organic light-emitting diodes (OLEDs), organic integrated circuits (OICs), organic field-effect transistors (O-FETs), organic thin-film transistors (O-TFTs), organic light-emitting transistors (O-LETs), organic solar cells (O-SCs), organic optical detectors, organic photoreceptors, organic field-quench devices (O-FQDs), light-emitting fuel cells (LECs), or organic laser diodes (O-lasers).

[0200] Bulb or Lamp: In some embodiments, the electronic device comprises an OLED comprising an anode, a cathode, and at least one organic layer comprising an emissive layer between the anode and the cathode. In some embodiments, the device includes OLEDs of different colors. In some embodiments, the device includes an array including a combination of OLEDs. In some embodiments, the combination of OLEDs is a three-color combination (e.g., RGB). In some embodiments, the combination of OLEDs is a combination of colors that are not red, green, or blue (e.g., orange and yellow-green). In some embodiments, the combination of OLEDs is a two-color, four-color, or more-color combination. In some embodiments, the device comprises: a circuit board having a first side with a mounting surface and an opposite second side, the circuit board defining at least one opening; at least one OLED on the mounting surface, the at least one OLED having a light-emitting configuration including an anode, a cathode, and at least one organic layer including a light-emitting layer between the anode and the cathode; a housing for the circuit board; and at least one connector disposed on an end of the housing, the housing and the connector defining a package suitable for attachment to a lighting fixture. In some embodiments, the OLED light comprises multiple OLEDs mounted on a circuit board such that light is emitted in multiple directions. In some embodiments, some of the light emitted in a first direction is polarized and emitted in a second direction. In some embodiments, a reflector is used to polarize the light emitted in the first direction.

[0201] Display or Screen: In some embodiments, the light-emitting layer of the present invention can be used in a screen or display. In some embodiments, the compounds of the present invention are deposited onto a substrate using processes such as, but not limited to, vacuum evaporation, deposition, vapor deposition, or chemical vapor deposition (CVD). In some embodiments, the substrate is a photoplate structure useful for two-sided etching to provide pixels with unique aspect ratios. The screen (also called a mask) is used in the manufacturing process of OLED displays. The corresponding artwork pattern design allows for the placement of very steep, narrow tie bars between pixels in the vertical direction and large, wide, beveled openings in the horizontal direction. This allows for the fine patterning of pixels required for high-resolution displays while optimizing chemical vapor deposition onto the TFT backplane. Internal pixel patterning allows for the construction of three-dimensional pixel openings with various aspect ratios in the horizontal and vertical directions. Furthermore, the use of imaged "stripes" or halftone circles within the pixel area protects etching in specific regions until these specific patterns are undercut and removed from the substrate. At that point, all pixel areas are subjected to similar etch rates, but the depth varies depending on the halftone pattern. Varying the size and spacing of the halftone patterns allows for etching with varying degrees of protection within the pixel, enabling the deep, localized etching required to create steep vertical bevels. The preferred material for the deposition mask is Invar, a metal alloy that is cold-rolled into long, thin sheets at steel mills. Invar cannot be electrodeposited onto the spin mandrel as a nickel mask. A suitable, low-cost method for forming open areas in the deposition mask is by wet chemical etching. In some embodiments, the screen or display pattern is a pixel matrix on a substrate. In some embodiments, the screen or display pattern is fabricated using lithography (e.g., photolithography and e-beam lithography). In some embodiments, the screen or display pattern is fabricated using wet chemical etching. In further embodiments, the screen or display pattern is fabricated using plasma etching.

[0202] Device manufacturing method: OLED displays are generally manufactured by forming a large mother panel and then cutting the mother panel into cell panels. Typically, each cell panel on the mother panel is formed by forming a thin film transistor (TFT) having an active layer and source / drain electrodes on a base substrate, applying a planarizing film to the TFT, sequentially forming a pixel electrode, an emissive layer, a counter electrode, and an encapsulation layer, and then cutting the mother panel. OLED displays are generally manufactured by forming a large mother panel and then cutting the mother panel into cell panels. Typically, each cell panel on the mother panel is formed by forming a thin film transistor (TFT) having an active layer and source / drain electrodes on a base substrate, applying a planarizing film to the TFT, sequentially forming a pixel electrode, an emissive layer, a counter electrode, and an encapsulation layer, and then cutting the mother panel.

[0203] In another aspect of the present invention, there is provided a method for manufacturing an organic light emitting diode (OLED) display, the method comprising: forming a barrier layer on a base substrate of the mother panel; forming a plurality of display units on the barrier layer in cell panel units; forming an encapsulation layer over each of the display units of the cell panel; and applying an organic film to the interface between the cell panels. In some embodiments, the barrier layer is an inorganic film, for example, made of SiNx, and the edges of the barrier layer are covered with an organic film made of polyimide or acrylic. In some embodiments, the organic film helps the mother panel to be softly cut into individual cell panels. In some embodiments, the thin film transistor (TFT) layer includes a light-emitting layer, a gate electrode, and source / drain electrodes. Each of the plurality of display units may include a thin film transistor (TFT) layer, a planarization film formed on the TFT layer, and a light-emitting unit formed on the planarization film, and the organic film applied to the interface is formed of the same material as the planarization film and is formed simultaneously with the planarization film. In some embodiments, the light-emitting unit is connected to the TFT layer by a passivation layer, the planarization film therebetween, and an encapsulation layer that covers and protects the light-emitting unit. In some embodiments of the manufacturing method, the organic film is not connected to either the display unit or the encapsulation layer.

[0204] Each of the organic film and the planarization film may comprise one of polyimide and acrylic. In some embodiments, the barrier layer may be an inorganic film. In some embodiments, the base substrate may be formed of polyimide. The method may further include attaching a carrier substrate formed of a glass material to one surface of the base substrate formed of polyimide before forming the barrier layer on the other surface of the base substrate, and separating the carrier substrate from the base substrate before cutting along the interface. In some embodiments, the OLED display is a flexible display. In some embodiments, the passivation layer is an organic film disposed on the TFT layer to cover the TFT layer. In some embodiments, the planarization film is an organic film formed on the passivation layer. In some embodiments, the planarization film is formed of polyimide or acrylic, as is the organic film formed on the edge of the barrier layer. In some embodiments, the planarization film and the organic film are formed simultaneously during the manufacture of an OLED display. In some embodiments, the organic film may be formed on the edge of the barrier layer, such that a portion of the organic film directly contacts the base substrate and a remaining portion of the organic film contacts the barrier layer while surrounding the edge of the barrier layer.

[0205] In some embodiments, the light-emitting layer comprises a pixel electrode, a counter electrode, and an organic light-emitting layer disposed between the pixel electrode and the counter electrode, hi some embodiments, the pixel electrode is coupled to a source / drain electrode of the TFT layer. In some embodiments, when a voltage is applied to the pixel electrode through the TFT layer, a suitable voltage is formed between the pixel electrode and the counter electrode, which causes the organic light-emitting layer to emit light, thereby forming an image. Hereinafter, an image-forming unit having a TFT layer and a light-emitting unit is referred to as a display unit. In some embodiments, the encapsulation layer that covers the display units and prevents penetration of external moisture may be formed into a thin-film encapsulation structure in which organic films and inorganic films are alternately stacked. In some embodiments, the encapsulation layer has a thin-film encapsulation structure in which multiple thin films are stacked. In some embodiments, the organic film applied to the interface portion is disposed at an interval with each of the multiple display units. In some embodiments, the organic film is formed in such a manner that a portion of the organic film directly contacts the base substrate and the remaining portion of the organic film contacts the barrier layer while surrounding the edge of the barrier layer.

[0206] In one embodiment, the OLED display is flexible and uses a flexible base substrate formed of polyimide, hi some embodiments, the base substrate is formed on a carrier substrate formed of a glass material, and the carrier substrate is then separated. In some embodiments, a barrier layer is formed on the surface of the base substrate opposite the carrier substrate. In one embodiment, the barrier layer is patterned according to the size of each cell panel. For example, while the base substrate is formed on all surfaces of the mother panel, the barrier layer is formed according to the size of each cell panel, thereby forming grooves at the interfaces between the barrier layers of the cell panels. Each cell panel can be cut along the grooves.

[0207] In some embodiments, the manufacturing method further includes a step of cutting along the interface, in which a groove is formed in the barrier layer and at least a portion of the organic film is formed in the groove, so that the groove does not penetrate the base substrate. In some embodiments, the TFT layer of each cell panel is formed, and a passivation layer (an inorganic film) and a planarization film (an organic film) are disposed on and cover the TFT layer. At the same time as the planarization film (e.g., polyimide or acrylic) is formed, the grooves at the interface are covered with an organic film (e.g., polyimide or acrylic). This prevents cracks from occurring when each cell panel is cut along the grooves at the interface by allowing the organic film to absorb any impacts that may occur. That is, if all barrier layers were completely exposed without the organic film, the impacts would be transmitted to the barrier layers when each cell panel was cut along the grooves at the interface, thereby increasing the risk of cracks. However, in one embodiment, the grooves at the interface between the barrier layers are covered with an organic film to absorb any impacts that would otherwise be transmitted to the barrier layers, allowing each cell panel to be cut softly and preventing cracks from occurring in the barrier layers. In one embodiment, the organic film and the planarizing film covering the groove of the interface portion are spaced apart from each other. For example, if the organic film and the planarizing film are connected to each other as one layer, external moisture may penetrate into the display unit through the planarizing film and the remaining portion of the organic film, so the organic film and the planarizing film are spaced apart from each other so that the organic film is spaced apart from the display unit.

[0208] In some embodiments, the display unit is formed by forming a light-emitting unit, and an encapsulation layer is disposed on the display unit to cover the display unit. Thus, after the mother panel is completely manufactured, the carrier substrate carrying the base substrate is separated from the base substrate. In some embodiments, when a laser beam is irradiated onto the carrier substrate, the carrier substrate is separated from the base substrate due to the difference in thermal expansion coefficient between the carrier substrate and the base substrate. In some embodiments, the mother panel is cut into individual cell panels. In some embodiments, the mother panel is cut along the interface between the cell panels using a cutter. In some embodiments, the grooves at the interface along which the mother panel is cut are covered with an organic film, which absorbs shock during cutting. In some embodiments, this can prevent cracks from occurring in the barrier layer during cutting. In some embodiments, the method reduces product rejection rates and stabilizes product quality. Another embodiment is an OLED display having a barrier layer formed on a base substrate, a display unit formed on the barrier layer, an encapsulation layer formed on the display unit, and an organic film applied to the edges of the barrier layer. [Example]

[0209] The features of the present invention will be explained in more detail below with reference to examples. The materials, processing details, processing procedures, etc. described below can be modified as appropriate without departing from the spirit of the present invention. Therefore, the scope of the present invention should not be construed as being limited by the specific examples shown below. The light-emitting performance was evaluated using a source meter (Keithley: 2400 series), a semiconductor parameter analyzer (Agilent Technologies: E5273A), an optical power meter (Newport: 1930C), an optical spectrometer (Ocean Optics: USB2000), a spectroradiometer (Topcon: SR-3), and a streak camera (Hamamatsu Photonics K.K.: C4334). The orientation value was measured using a molecular orientation property measurement device (Hamamatsu Photonics K.K.: C14234-01).

[0210] <First to third organic compounds used in examples and comparative examples> The first to third organic compounds used in the following examples and comparative examples are shown below. [ka] [ka]

[0211] The HOMO energy E of the above compound HOMO , LUMO energy E LUMO The lowest excited singlet energy E measured for some compounds is shown in Table 1 below. S1 and the lowest excited triplet energy E T1 is also shown.

[0212] [Table 1]

[0213] (Examples 1 to 10, Comparative Examples 5 to 7, 9, 10, and 12) Each thin film was deposited by vacuum deposition on a 2 mm thick glass substrate with a 50 nm thick indium tin oxide (ITO) anode at a vacuum level of 1×10 -6 The layers were laminated using a Pa process. First, HATCN was evaporated onto ITO to a thickness of 5 nm to form a hole injection layer, and NPD was evaporated on top of that to a thickness of 60 nm to form a hole transport layer. Next, EB1 was evaporated to a thickness of 5 nm to form an electron blocking layer. Next, the first organic compound, the second organic compound, and the third organic compound were co-evaporated from different evaporation sources to form a 40 nm thick light-emitting layer, with the composition shown in Table 2 or Table 3. Next, HB1 was evaporated to a thickness of 10 nm to form a hole blocking layer, and then ET1 was evaporated to a thickness of 30 nm to form an electron transport layer. Furthermore, Liq was evaporated to a thickness of 2 nm to form an electron injection layer, and then aluminum (Al) was evaporated to a thickness of 100 nm to form a cathode. Organic electroluminescence devices were fabricated using this process. All of the devices fabricated here satisfied formula (a), and it was confirmed that the largest component of the light emission was fluorescence from the third organic compound.

[0214] (Comparative Examples 1 to 4, 8, and 11) An organic electroluminescence device was fabricated in the same manner as in Example 1, except that when forming the light-emitting layer, the light-emitting layer having the composition shown in Table 2 was formed by co-evaporation of the first organic compound and the second organic compound without using a vapor deposition source of the third organic compound.

[0215] (Emitting layer composition and evaluation results) Table 2 shows the composition of the emitting layer and the measurement results of the external quantum efficiency EQE and maximum emission wavelength for each of the devices fabricated in Examples 1 to 6 and Comparative Examples 1 to 10. Of the compositions of the emitting layer, the composition ratio of the third organic compound in Examples 1 to 4 and Comparative Examples 5 to 7, 9, and 10 is expressed as a percentage (wt%) relative to the total weight of the first organic compound and the second organic compound, and the composition ratios of the other organic compounds are expressed as percentages (wt%) relative to the total weight of the organic compounds constituting the emitting layer. In Table 2, "-" indicates that no third organic compound was added.

[0216] [Table 2]

[0217] As shown in Table 2, the devices of Examples 1 to 6, in which the orientation value S of the third organic compound was −0.3 or less, exhibited higher external quantum efficiency than the devices of Comparative Examples 1 to 3, which did not contain the third organic compound in the light-emitting layer. Furthermore, the devices of Examples 2, 4, and 6, in which the concentration of the third organic compound was higher, exhibited higher external quantum efficiency than the devices of Examples 1, 3, and 5. In contrast, the devices of Comparative Examples 5 to 7, 9 to 10, and 12, in which the orientation value S of the third organic compound was greater than −0.3, exhibited lower external quantum efficiency than the devices of Comparative Examples 4, 8, and 11, which had the same configuration except for not containing the third organic compound in the light-emitting layer. Furthermore, the results of Comparative Examples 5 to 7 and 9 to 10 indicated a tendency for the external quantum efficiency to decrease as the concentration of the third organic compound increased. These results confirmed that, even in devices in which the LUMO energy of the third organic compound is lower than that of the second organic compound, the external quantum efficiency can be improved by increasing the concentration of the third organic compound as long as the orientation value S of the third organic compound is −0.3 or less.

[0218] The composition of the light-emitting layer of each device fabricated in Examples 7 to 10 and the evaluation results of durability are shown in Table 3. In Table 3, "LT95%" indicates that each device was discharged at 12.6 mA / cm 2 The time (T95%) until the luminance reached 95% of the initial luminance was measured when the device was continuously driven at a current density of 1000 Hz, and the T95% value was divided by the T95% of the device fabricated in Example 7 to calculate a relative value. A larger LT95% value indicates better durability.

[0219] [Table 3]

[0220] The elements of Examples 7 to 10 had different concentrations of the second organic compound in the light-emitting layer, and all had the same maximum emission wavelength of 529 nm and external quantum efficiency of approximately 22%. Table 3 also shows that increasing the concentration of the second organic compound tends to improve the durability of the elements.

[0221] [ka] [Industrial Applicability]

[0222] According to the present invention, in an organic electroluminescent device including a first organic compound, a second organic compound that is a delayed fluorescent material, and a third organic compound that emits fluorescence in an emissive layer, even if the LUMO energy of the first organic compound is lower than that of the second organic compound, the concentration of the second organic compound can be increased to improve external quantum efficiency. This allows for a wider range of options for the LUMO energy of the third organic compound, thereby increasing the degree of freedom in material design for organic electroluminescent devices. Therefore, the present invention has high industrial applicability.

Claims

1. An organic electroluminescence element having an anode, a cathode, and at least one organic layer including a light-emitting layer between the anode and the cathode, The light-emitting layer contains a first organic compound, a second organic compound, and a third organic compound, and satisfies the following formula (a) and formula (b): the second organic compound is a delayed fluorescent material, The third organic compound is a compound represented by the following general formula (16): An organic electroluminescence element, wherein the largest component of light emitted from the organic electroluminescence element is fluorescence from the third organic compound. [Equation 1] [where: E LUMO (2) is the LUMO energy of the second organic compound E LUMO (3) is the LUMO energy of the third organic compound S represents the orientation value of the third organic compound in the light-emitting layer.] General formula (16) 【number】 [In the general formula (16), X １ and X ２ is a nitrogen atom on one side and a boron atom on the other side. １ ~R ２６ , A １ , A ２ R each independently represents a hydrogen atom, a deuterium atom, or a substituent. １ and R ２ , R ２ and R ３ , R ３ and R ４ , R ４ and R ５ , R ５ and R ６ , R ６ and R ７ , R ７ and R ８ , R ８ and R ９ , R ９ and R １０ , R １０ and R １１ , R １１ and R １２ , R １３ and R １４ , R １４ and R １５ , R １５ and R １６ , R １６ and R １７ , R １７ and R １８ , R １８ and R １９ , R １９ and R ２０ , R ２０ and R ２１ , R ２１ and R ２２ , R ２２ and R ２３ , R ２３ and R ２４ , R ２４ and R ２５ , R ２５ and R ２６ may be bonded to each other to form a cyclic structure. １ is a nitrogen atom, R １７ and R １８ are bonded to each other as a single bond to form a pyrrole ring, and X ２ is a nitrogen atom, R ２１ and R ２２ are bonded to each other to form a single bond to form a pyrrole ring. １ is a nitrogen atom, and R ７ and R ８ and R ２１ and R ２２ are bonded via a nitrogen atom to form a 6-membered ring, and R １７ and R １８ are bonded to each other to form a single bond, R １ ~R ６ At least one of R is a substituted or unsubstituted aryl group, or １ and R ２ , R ２ and R ３ , R ３ and R ４ , R ４ and R ５ , R ５ and R ６ are bonded to each other to form an aromatic ring or a heteroaromatic ring.

2. 2. The organic electroluminescence device according to claim 1, wherein the concentration of the third organic compound in the light-emitting layer is greater than 0.3% by weight.

3. 3. The organic electroluminescence device according to claim 1, wherein the concentration of the second organic compound in the light-emitting layer is 25% by weight or more.

4. 4. The organic electroluminescence device according to claim 1, wherein the second organic compound has a structure in which one or two cyano groups and at least one donor group are bonded to a benzene ring.

5. 5. The organic electroluminescence device according to claim 4, wherein the donor group has a structure in which a substituted or unsubstituted benzofuran ring is condensed with a benzene ring constituting a carbazol-9-yl group.

6. 6. The organic electroluminescence device according to claim 5, wherein the donor group is a substituted or unsubstituted 5H-benzofuro[3,2-c]carbazol-5-yl group.

7. 7. The organic electroluminescence device according to claim 4, wherein three or more of the donor groups are bonded to the benzene ring.

8. 8. The organic electroluminescence device according to claim 1, wherein the first organic compound, the second organic compound, and the third organic compound satisfy the following (a1): E LUMO (1) > E LUMO (2) > E LUMO (3) Formula (a1) [where: E LUMO (1) is the LUMO energy of the first organic compound E LUMO (2) is the LUMO energy of the second organic compound E LUMO (3) is the LUMO energy of the third organic compound S represents the orientation value of the third organic compound in the light-emitting layer.]

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