Top-emission organic electroluminescent device and design method thereof

Abstract

To provide an organic electroluminescent element with high luminous efficiency.SOLUTION: A top emission organic electroluminescent element has a light-emitting layer including first to third organic compounds. The second organic compound having a lower ES1 than that of the first organic compound is a delayed fluorescent material. The third organic compound having the lowest ES1 and higher ELUMO and EHOMO than those of the second organic compound has an S value of -0.38 or less and a half value width of 31 nm or less.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a top-emission organic electroluminescent device. The present invention also relates to a method for evaluating the light-emitting performance of a film and a method for determining conditions suitable for film formation. The present invention also relates to a design method, program, and database for an organic electroluminescent device. [Background technology]

[0002] Organic electroluminescent elements (organic EL elements) are self-luminous and do not require a backlight, making them lightweight and flexible. They also have the advantages of fast response and high visibility, making them promising light sources and display elements. On the other hand, there is still room for improvement in the luminous efficiency of organic electroluminescent elements, and various materials and element structures have been proposed to further improve the luminous efficiency (see, for example, Patent Documents 1 to 6). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2002-231459 [Patent Document 2] US Patent No. 9099674 [Patent Document 3] US Patent No. 8,686,420 [Patent Document 4] Japanese Patent Application Laid-Open No. 2004-013991 [Patent Document 5] Japanese Patent Application Laid-Open No. 2012-160632 [Patent Document 6] International Publication No. 2012 / 111462 Brochure Summary of the Invention [Problem to be solved by the invention]

[0004] However, most of the proposals for organic electroluminescent devices to date have focused on either material types or device structures, without examining the combination of material types and device structures. Therefore, it is unclear what device characteristics can be obtained with combinations other than the specific material types and device structures adopted in those proposals. For example, even if a material type is proposed as being excellent, if it is used in a device structure other than the one adopted therein, it may not be able to substantially function as a light-emitting element. Conversely, even if a device structure is proposed as being excellent, it may not exhibit good light-emitting performance depending on the material type used therein. In other words, the luminous efficiency obtained by combining a specific material type and device structure cannot be predicted without actually manufacturing the device. Therefore, from the proposals for organic electroluminescent devices to date, it is difficult to find a combination of material types and device structures that will result in high luminous efficiency.

[0005] In order to solve these problems, the present inventors have conducted extensive research with the aim of providing an organic electroluminescence element with high luminous efficiency by appropriately combining material types and element structures. [Means for solving the problem]

[0006] As a result of extensive research, the present inventors have found that the luminous efficiency of a top-emission organic electroluminescence element can be improved by incorporating an emitting layer made of a material that satisfies specific conditions into the element. The present invention has been proposed based on these findings, and specifically has the following configuration.

[0007] [1] A top-emission organic electroluminescence element having a laminated structure having, in order, a substrate, a first electrode, a light-emitting layer, and a transparent second electrode, The light-emitting layer contains a first organic compound, a second organic compound, and a third organic compound that satisfy the following formulas (a) to (c): the second organic compound is a delayed fluorescent material, the S value of the third organic compound in the light-emitting layer is −0.38 or less; an organic electroluminescence device, wherein the full width at half maximum (FWHM) of the emission spectrum of the third organic compound is 31 nm or less; E S1 (1)> E S1 (2)> E S1 (3) Formula (a) E LUMO (2)≦ E LUMO (3) Formula (b) E HOMO (2)≦ E HOMO (3) Formula (c) [where: E S1 (1) is the lowest excited singlet energy of the first organic compound E S1 (2) is the lowest excited singlet energy of the second organic compound E S1 (3) is the lowest excited singlet energy of the third 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 E HOMO (2) is the energy of the HOMO of the second organic compound E HOMO (3) represents the HOMO energy of the third organic compound. [2] The organic electroluminescence device according to [1], wherein recombination of holes and electrons occurs in the light-emitting layer. [3] The organic electroluminescence device according to [1] or [2], 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. [4] The organic electroluminescence device according to [3], wherein the donor group is a substituted or unsubstituted carbazol-9-yl group. [5] The organic electroluminescence device according to [3], wherein three or more substituted or unsubstituted carbazol-9-yl groups are bonded to the benzene ring. [6] The organic electroluminescence element according to any one of [1] to [5], wherein the third organic compound is a compound having a multiple resonance effect of a boron atom and a nitrogen atom, or a compound containing a fused aromatic ring structure. [7] A method for evaluating the luminescence performance of a film containing a first organic compound, a second organic compound, and a third organic compound that satisfy the above formulas (a) to (c), comprising: A method for evaluating the luminescence performance of a film using the S value of the third organic compound and the half width of the luminescence spectrum of the third organic compound as indicators. [8] The method according to [7], wherein the evaluation is based on the criteria that the half-width is 31 nm or less and the S value is -0.38 or less. [9] The method according to [7] or [8], for evaluating the usefulness of a compound as a light-emitting layer in a top-emission organic electroluminescence device.

[10] The method according to [9], which predicts the luminous efficiency of the device.

[11] The method according to any one of [7] to

[10] , for evaluating the relative merits of multiple films.

[12] Forming a film containing a first organic compound, a second organic compound, and a third organic compound that satisfy the above formulas (a) to (c) under certain conditions; measuring the S value and the half width of the emission spectrum of the third organic compound in the formed film; forming a film containing the first organic compound, the second organic compound, and the third organic compound under conditions different from the above conditions, and measuring the S value and half width of the emission spectrum of the third organic compound in the formed film, and repeating this process at least once; A method for determining conditions suitable for film formation by evaluating the S value and the half-width as indicators.

[13] The method according to

[12] , wherein the determination is made after newly designing conditions suitable for the film formation based on the evaluation.

[14] A method for designing an organic electroluminescence device, comprising forming a light-emitting layer under conditions determined by the method according to

[12] or

[13] .

[15] A program for implementing the method described in

[12] or

[13] or the design described in

[14] .

[16] A database that accumulates data on the conditions, S values, and half-widths in

[12] . [Effects of the Invention]

[0008] The top-emission organic electroluminescent device of the present invention has high luminous efficiency. Furthermore, the method of the present invention allows for easy evaluation of the luminous performance of the film, enabling accurate identification of conditions for forming an emitting layer with good luminous performance, and enabling the design of an excellent organic electroluminescent device. Furthermore, the use of the program and database of the present invention allows for efficient evaluation and design. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a schematic cross-sectional view showing a layer structure of an organic electroluminescence element according to a first embodiment. [Figure 2] FIG. 5 is a schematic cross-sectional view showing the layer structure of an organic electroluminescence element according to a second embodiment. [Figure 3] 10 is a graph showing the relationship between the external quantum yield (EQE) of the organic electroluminescence elements TE1 to TE6 and the full width at half maximum (FWHM) of the spectrum of the third organic compound. [Figure 4] 10 is a graph showing the relationship between the emission peak intensity (PI) of organic electroluminescence elements TE1 to TE6 and the full width at half maximum (FWHM) of the spectrum of a third organic compound. [Figure 5] 10 is a graph showing the relationship between the external quantum yield (EQE) of organic electroluminescence elements TE1 to TE6 and the S value of the third organic compound in the emitting layer. [Figure 6] 10 is a graph showing the relationship between the emission peak intensity (PI) of organic electroluminescence elements TE1 to TE6 and the S value of the third organic compound in the emitting layer. [Figure 7] 10 is a graph showing the relationship between the evanescent mode of the top emission devices TE1 to TE6 and the full width at half maximum (FWHM) of the spectrum of the third organic compound. [Figure 8] 10 is a graph showing the relationship between the evanescent mode of the top-emission devices TE1 to TE6 and the S value of the third organic compound in the light-emitting layer. [Figure 9] 1 is a flowchart illustrating a method for determining conditions suitable for film formation according to the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0010] 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 ( 2 In 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.

[0011] The organic electroluminescent element of the present invention is a top-emission organic electroluminescent element having a laminated structure having, in order, a substrate, a first electrode, a light-emitting layer, and a transparent second electrode. Layers may or may not be interposed between the substrate and the first electrode, between the first electrode and the light-emitting layer, and between the light-emitting layer and the second electrode. The first electrode and the light-emitting layer may be laminated so as to be in direct contact with each other, or the light-emitting layer may be laminated above the first electrode so as not to be in direct contact with each other. The light-emitting layer and the second electrode may be laminated so as to be in direct contact with each other, or the second electrode may be laminated above the light-emitting layer so as not to be in direct contact with each other. The light-emitting layer is preferably located between the first electrode and the second electrode, and the entire light-emitting layer is preferably disposed without extending beyond the region between the first electrode and the second electrode. The organic electroluminescence element of the present invention is a top-emission element. Therefore, light emitted from the light-emitting layer is emitted at least from the second electrode side. The amount of light emitted from the second electrode side is 60% or more of the amount of light emitted from the element, preferably 90% or more, and may be, for example, 99% or more, or even 100%. The specific configuration of the top-emission element will be described later.

[0012] The organic electroluminescent device of the present invention contains a first organic compound, a second organic compound, and a third organic compound in the light-emitting layer. The S value of the third organic compound in the light-emitting layer of the organic electroluminescence device of the present invention is -0.38 or less. The S value of the third organic compound is more preferably -0.40 or less, even more preferably -0.41 or less, and even more preferably -0.42 or less. The S value is also called the orientation value, and is an index showing the degree of orientation of the third organic compound in the light-emitting layer. A larger negative value (a smaller numerical value) means a higher degree of orientation. The S value is calculated based on the S value reported in Scientific Reports 2017, 7, 8405. In the organic electroluminescence device of the present invention, the full width at half maximum (FWHM) of the emission spectrum of the third organic compound is 31 nm or less. The full width at half maximum is preferably 26 nm or less, more preferably 23 nm or less, and even more preferably 20 nm or less. The full width at half maximum of the emission spectrum here refers to the full width at half maximum of the emission peak intended to be used as light emission. It is usually the full width at half maximum of the emission peak having the maximum emission intensity, and preferably the full width at half maximum of the emission peak having the maximum emission intensity in the visible region. In a preferred embodiment of the present invention, the third organic compound has an S value of -0.41 or less and a half-width of 23 nm or less. In a more preferred embodiment of the present invention, the third organic compound has an S value of -0.42 or less and a half-width of 23 nm or less. In an even more preferred embodiment of the present invention, the third organic compound has an S value of -0.42 or less and a half-width of 20 nm or less.

[0013] The first organic compound, the second organic compound, and the third organic compound contained in the light-emitting layer satisfy the following formulas (a) to (c). E S1 (1)> E S1 (2)> E S1 (3) Formula (a) E LUMO (2)≦ E LUMO (3) Formula (b) E HOMO (2)≦ E HOMO (3) Formula (c)

[0014] E in formula (a) 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 the present invention, 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).

[0015] Since the present invention satisfies the relationship of formula (a), among the first organic compound, the second organic compound, and the third organic compound contained in the light-emitting layer, 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.

[0016] E in formula (b) 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 (b), the LUMO energy of the second organic compound contained in the light-emitting layer is equal to or lower than the LUMO energy of the third organic compound. LUMO (3)-E LUMO (2)] can be, for example, 0.05 eV or more, 0.10 eV or more, or 0.13 eV or more, or 0.40 eV or less, 0.30 eV or less, or 0.20 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 second 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 third organic compound.

[0017] E in formula (c) HOMO (2) represents the HOMO energy of the second organic compound, and E HOMO (3) represents the HOMO energy of the third organic compound. HOMO is an abbreviation for Highest Occupied 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 (c), the HOMO energy of the second organic compound contained in the light-emitting layer is equal to or lower than the HOMO energy of the third organic compound. HOMO (3)-E HOMO(2)] can be, for example, 0.05 eV or more, 0.10 eV or more, or 0.13 eV or more, or 0.40 eV or less, 0.30 eV or less, or 0.20 eV or less. 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 second 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 -5.0 to -6.0 eV can be used as the third organic compound.

[0018] When the contents 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) is 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, or 30% by weight or more, or can be in the range of 45% by weight or less, or 40% by weight or less, or 35% by weight or less. Conc(3) is preferably 5% by weight or less, and more preferably 3% by weight or less. Conc(3) can be in the range of 0.01% by weight or more, 0.1% by weight or more, or 0.3% by weight or more, and can be in the range of 2% by weight or less, or 1% by weight or less. 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 5 or more, 10 or more, 20 or more, or 30 or more, and can be in the range of 500 or less, 300 or less, or 100 or less.

[0019] 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.

[0020] (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 minimum excited singlet energy greater than that of the second organic compound and the third organic compound. The first organic compound preferably functions as a host material responsible for carrier transport. The first organic compound also preferably 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 organic compound and the second organic compound 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.

[0021] [ka] JPEG0007810383000002.jpg244170JPEG0007810383000003.jpg145170

[0022] (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 minimum excited singlet energy smaller than that of the first organic compound and larger than that of the third organic compound, and also having lower HOMO and LUMO energies than that of the third organic compound. In the present invention, a "delayed fluorescent material" is 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). Although the second organic compound is capable of emitting delayed fluorescence, it is not essential that the second organic compound emit delayed fluorescence when used in the organic electroluminescent 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 electroluminescent 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.

[0023] The second organic compound has a difference ΔE between the lowest excited singlet energy and the lowest excited triplet energy at 77 K. STis 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.

[0024] 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 -5 A 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.

[0025] 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.

[0026] 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.

[0027] 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]

[0028] 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 5At 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]

[0029] 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 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 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.

[0030] 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.

[0031] 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 X3 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 X 4 , 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 5At 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 5 When 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.

[0032] 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]

[0033] In general formula (3), R 11 and R 12R 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 12 may 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.

[0034] 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]

[0035] 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.

[0036] 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.

[0037] 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).

[0038] 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.

[0039] 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]

[0040] 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.

[0041] 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]

[0042] 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.

[0043] 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]

[0044] 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]

[0045] 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).

[0046] 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]

[0047] 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]

[0048] 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).

[0049] 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]

[0050] 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]

[0051] In general formulas (12) to (14), D represents a donor group, A represents an acceptor group, and R represents a hydrogen atom, a deuterium atom, or a substituent. For descriptions and preferred ranges of the donor group and the acceptor group, please refer 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 (14) 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] JPEG0007810383000021.jpg82164

[0052] 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] JPEG0007810383000023.jpg122166

[0053] Preferred examples of R in the general formulae (12) to (14) are given below: In the following specific examples, * represents the bonding position, and "D" represents deuterium. [ka]

[0054] 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] JPEG0007810383000026.jpg236170JPEG0007810383000027.jpg233170JPEG00078103830 00028.jpg247166JPEG0007810383000029.jpg247170JPEG0007810383000030.jpg247170 JPEG0007810383000031.jpg216157JPEG0007810383000032.jpg230156JPEG00078103830 00033.jpg228170JPEG0007810383000034.jpg252170JPEG0007810383000035.jpg226164

[0055] As the second organic compound, other known delayed fluorescent materials can be used in appropriate combination, in addition to the above. Even unknown delayed fluorescent materials can be 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.

[0056] (Third organic compound) The third organic compound used in the light-emitting layer of the organic electroluminescent device of the present invention is a fluorescent material having a minimum excited singlet energy smaller than those of the first organic compound and the second organic compound, and having higher HOMO and LUMO energies than those of the second organic compound. 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 organic electroluminescent device of the present invention is light emission from the third organic compound. That is, the amount of light emitted from the third organic compound is the largest among the light emission from the organic electroluminescent device of the present invention. 70% or more of the light emission from the organic electroluminescent device may be light emission from the third organic compound, 90% or more of the light emission from the third organic compound, or 99% or more of the light emission from the third organic compound. 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, or the second organic compound that has undergone reverse intersystem crossing from an excited triplet state to an excited singlet state, and transitions to an excited singlet state. In a preferred embodiment of the present invention, the third organic compound receives energy from the second organic compound in an excited singlet state and from the second organic compound that has undergone reverse intersystem crossing from an excited triplet state to an excited singlet state, and transitions 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 fluorescent material used as the third organic compound is not particularly limited as long as it can receive energy from the first organic compound or the second organic compound and emit light, and the light emitted may include any of fluorescence, delayed fluorescence, and phosphorescence. It is preferable that the light emitted includes fluorescence or delayed fluorescence, and more preferable that the largest component of the light emitted 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.

[0057] 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.

[0058] Examples of the third organic compound include a compound having a multiple resonance effect of boron atoms and nitrogen atoms, and a compound containing a condensed aromatic ring structure such as anthracene, pyrene, or perylene. In a preferred embodiment of the present invention, a compound represented by the following general formula (15) is used as the third organic compound. General formula (15) [ka]

[0059] In the above general formula (15), Ar1 ~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.

[0060] The compound represented by the general formula (15) 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:

[0061] Ar 1 ~Ar 3may 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 ring 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.

[0062] A compound may contain a plurality of skeletons represented by general formula (15). For example, skeletons represented by general formula (15) may be bonded to each other via a single bond or a linking group. Furthermore, the skeleton represented by general formula (15) 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.

[0063] 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 (16): General formula (16) [ka]

[0064] In general formula (16), 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 (17). General formula (17) [ka] In general formula (17), 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 (17) is R1 ~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 (17). 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 (17), 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 (17). 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 7In 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.

[0065] R in general formula (17) 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 ~R 15The 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 (17) 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 (17) 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 (17) 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 (16) 1 ~R 7 Among them, R of general formula (17) 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.

[0066] In general formula (16), 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.

[0067] In one embodiment of the present invention, R in general formula (16) 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 (16) 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 (16), 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.

[0068] In one embodiment of the present invention, R in general formula (16) 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 (16) 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 present in R in the general formula (16). 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 (16), 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.

[0069] 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] JPEG0007810383000040.jpg227163JPEG0007810383000041.jpg229170

[0070] 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.

[0071] Furthermore, the compounds described in paragraphs 0220 to 0239 of WO2015 / 022974 can also be particularly preferably used as the third organic compound of the present invention.

[0072] (light-emitting layer) The light-emitting layer of the organic electroluminescent device of the present invention includes a first organic compound, a second organic compound, and a third organic compound that satisfy conditions (a) to (c). The light-emitting layer may be configured to contain, in addition to the first organic compound, the second organic compound, and the third organic compound, no compounds that transfer charge or energy or no metal elements other than boron. The light-emitting layer may also be configured solely of 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 of 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 of compounds consisting of atoms selected from the group consisting of carbon, hydrogen, deuterium, nitrogen, boron, and sulfur atoms. For example, the light-emitting layer may be configured solely of compounds consisting of atoms selected from the group consisting of carbon, hydrogen, deuterium, nitrogen, boron, and sulfur atoms. For example, the light-emitting layer can 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 can 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. Alternatively, 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, and nitrogen atoms, and a third organic compound consisting of atoms selected from the group consisting of carbon, hydrogen, deuterium, nitrogen, 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.

[0073] (Layer structure of top-emission organic electroluminescence element) Next, the layer structure of the organic electroluminescent element of the present invention will be described. The organic electroluminescent device of the present invention is a top-emission organic electroluminescent device having a layered structure including at least a substrate, a first electrode, a light-emitting layer, and a second electrode, in that order, and emitting light from the surface opposite the substrate (the second electrode side). The top-emission type is also called a "film surface-emission type." For details of its structure, see, for example, Applied Physical Letters, Vol. 65, pp. 2636-2638 (1994). In the following description, the layer structure will be represented by [ / ], which indicates the boundary between layers. For example, a structure in which a substrate, a first electrode, a light-emitting layer, and a second electrode are layered in this order will be represented as substrate / first electrode / light-emitting layer / second electrode. Here, the second electrode is transparent, and the first electrode may be either transparent or opaque. One of the first electrode and the second electrode functions as an anode, and the other functions as a cathode. Here, when both the first electrode and the second electrode are transparent and the substrate is also transparent, the organic electroluminescent element emits light from both the surface facing the substrate and the surface opposite the substrate. The top-emission organic electroluminescent element of the present invention includes not only single-sided emission organic electroluminescent elements that emit light only from the surface opposite the substrate, but also double-sided emission organic electroluminescent elements. Double-sided emission organic electroluminescent elements may allow external light to pass through in the thickness direction. In this case, an observer on the opposite side of the substrate of the organic electroluminescent element can view the scenery on the substrate side through the organic electroluminescent element. In addition to the light-emitting layer, one or more functional layers may be provided between the first electrode and the second electrode, such as a hole injection layer, a hole transport layer, an electron blocking layer, a hole blocking layer, an electron transport layer, or an electron injection layer. Specific structural examples of organic electroluminescence elements will be described below. In the following description, the layer between the first electrode and the second electrode will be referred to as the "intermediate layer."

[0074] <1> First embodiment of organic electroluminescence element In the organic electroluminescent element of the first embodiment, the first electrode functions as an anode and the second electrode functions as a cathode. Preferable specific examples (ai) to (a-viii) of this organic electroluminescent element are listed below. In the specific examples below, each layer is formed on the substrate in the order starting from the anode, with the anode facing the substrate and the cathode as the uppermost layer. Here, the hole transport layer may also function as an electron blocking layer. Furthermore, an electron blocking layer may be formed between the hole transport layer and the light-emitting layer, separate from the hole transport layer.

[0075] (ai) Anode / Emitting layer / Electron transport layer / Electron injection layer / Cathode (a-ii) Anode / hole transport layer / light-emitting layer / electron transport layer / electron injection layer / cathode (a-iii) Anode / hole transport layer / light-emitting layer / hole blocking layer / electron transport layer / electron injection layer / cathode (a-iv) Anode / hole injection layer / hole transport layer / light-emitting layer / electron transport layer / electron injection layer / cathode (av) anode / light-emitting layer / electron transport layer / electron injection layer / transparent protective layer / cathode (a-vi) Anode / hole transport layer / light-emitting layer / electron transport layer / electron injection layer / transparent protective layer / cathode (a-vii) Anode / hole transport layer / light-emitting layer / hole blocking layer / electron transport layer / electron injection layer / transparent protective layer / cathode (a-viii) Anode / hole injection layer / hole transport layer / light-emitting layer / electron transport layer / electron injection layer / transparent protective layer / cathode As a representative example, an organic electroluminescent device having the layer structure of (a-vii) is shown in Figure 1. In Figure 1, 1 represents a substrate, 2a represents an anode, 3 represents a hole injection layer, 4 represents a hole transport layer, 5 represents an emitting layer, 6 represents an electron transport layer, 7 represents an electron injection layer, 8 represents a transparent protective layer, and 9 represents a transparent conductive layer (cathode). Hereinafter, layers other than the light-emitting layer that constitute the organic electroluminescence element will be described.

[0076] [cathode] The cathode may be made of a transparent conductive material such as indium tin oxide (ITO), indium zinc oxide (IZO), SnO2, ZnO, or In2O3. Materials capable of forming an amorphous transparent conductive film, such as IDIXO (In2O3-ZnO), may also be used. The sheet resistance of the transparent conductive layer used in the cathode is preferably several hundred Ω / □ or less. The thickness of the cathode varies depending on the material, but is typically 10 to 1,000 nm, preferably 50 to 200 nm, and particularly preferably 100 nm.

[0077] [anode] Examples of materials for the anode include metals such as Ag, Mg, Al, Pt, Pd, Au, Ni, Nd, Ir, Cr, Li, Ca, LiF / Ca, and LiF / Al, or alloys thereof. The anode can be formed by thinly depositing these metals or alloys. The transparent conductive materials exemplified in the cathode section may also be used for the anode. The thickness of the anode varies depending on the material, but is typically 10 to 1,000 nm, and preferably 10 to 200 nm.

[0078] [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.

[0079] [ka]

[0080] Next, preferred examples of compounds that can be used as the electron injection material will be listed. [ka]

[0081] [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.

[0082] [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.

[0083] [ka]

[0084] [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 compounds that can be used as electron blocking materials are listed below.

[0085] [ka]

[0086] [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.

[0087] [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.

[0088] [ka]

[0089] [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.

[0090] [ka]

[0091] 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.

[0092] [ka]

[0093] [Transparent protective layer] In the organic electroluminescence device of the first embodiment, a transparent protective layer may be provided between the cathode and the organic light-emitting layer. The transparent protective layer is provided, for example, between the cathode and the electron injection layer. After the transparent protective layer is formed, the light-emitting layer and the electron injection layer are protected by the transparent protective layer, thereby preventing the light-emitting layer and the electron injection layer from deteriorating in subsequent processes. The transparent protective layer may also be patterned. This allows electrical contact between the cathode and the electron injection layer, thereby reducing the driving voltage of the device. Examples of the pattern of the transparent protective layer include stripes and lattices, and the spacing between the lines is preferably 500 to 5,000 μm. Examples of methods for patterning the transparent protective layer include a shadow mask method, a laser thermal transfer method, a laser deposition method, a laser ablation method, an inkjet method, and a printing method. Examples of materials for the transparent protective layer include metal complexes such as tris(8-quinolinolato)aluminum, and metal oxides such as molybdenum oxide and vanadium oxide. The thickness of the transparent protective layer is not particularly limited, but is preferably 50 to 200 nm.

[0094] [Auxiliary electrode] The organic electroluminescent element of the first embodiment may have an auxiliary electrode on the cathode, which reduces the electrical resistance of the element and allows the driving voltage to be lowered. The auxiliary electrode may be made of a low-resistance metal such as Au, Pt, Pd, Ag, Cu, or Al. The auxiliary electrode preferably has a line width of 1 to 50 μm. This allows the auxiliary electrode to function satisfactorily while ensuring the aperture ratio of the light-emitting surface. When the organic electroluminescence element has the transparent protective layer, the auxiliary electrode is preferably formed in an area where the transparent protective layer is not formed.

[0095] In the organic electroluminescent element of the first embodiment configured as described above, when an electric field is applied between the anode and cathode, holes and electrons injected from each electrode recombine in the organic light-emitting layer, causing the light-emitting material to enter an excited state. The light emitted from the excited light-emitting material is then emitted to the outside, causing the organic electroluminescent element to emit light. In the organic electroluminescent element of the first embodiment, the cathode disposed on the opposite side of the substrate is transparent, so that light emitted by the light-emitting material is emitted from the cathode side (the side opposite the substrate). Since the cathode side does not have wiring or drive elements like those formed on the substrate, the aperture ratio is high, enabling high light extraction efficiency.

[0096] <2> Second embodiment of organic electroluminescence element In the organic electroluminescent element of the second embodiment, the first electrode functions as a cathode and the second electrode functions as an anode. Preferable specific examples (bi) to (b-viii) of this organic electroluminescent element are listed below. In the specific examples below, each layer is formed on the substrate in the order starting from the cathode, with the cathode facing the substrate and the anode being the uppermost layer. Here, the hole transport layer may also function as an electron blocking layer. Furthermore, an electron blocking layer may be formed between the hole transport layer and the organic light-emitting layer, separate from the hole transport layer.

[0097] (bi) anode / organic light-emitting layer / electron transport layer / electron injection layer / cathode (b-ii) Anode / hole transport layer / organic light-emitting layer / electron transport layer / electron injection layer / cathode (b-iii) Anode / hole transport layer / organic light-emitting layer / hole blocking layer / electron transport layer / electron injection layer / cathode (b-iv) Anode / hole injection layer / hole transport layer / organic light-emitting layer / electron transport layer / electron injection layer / cathode (bv) Anode / Transparent protective layer / Organic light-emitting layer / Electron transport layer / Electron injection layer / Cathode (b-vi) Anode / transparent protective layer / hole transport layer / organic light-emitting layer / electron transport layer / electron injection layer / cathode (b-vii) Anode / transparent protective layer / hole transport layer / organic light-emitting layer / hole blocking layer / electron transport layer / electron injection layer / cathode (b-viii) Anode / transparent protective layer / hole injection layer / hole transport layer / organic light-emitting layer / electron transport layer / electron injection layer / cathode As a representative example, an organic electroluminescent device having the layer structure of (b-viii) is shown in Figure 2. In Figure 2, 1 represents a substrate, 2b represents a cathode, 3 represents a hole injection layer, 4 represents a hole transport layer, 5 represents an organic light-emitting layer, 6 represents an electron transport layer, 7 represents an electron injection layer, 8 represents a transparent protective layer, and 9 represents a transparent conductive layer (anode). For explanations, preferred ranges, and specific examples of the cathode, organic light-emitting layer, electron injection layer, hole injection layer, electron transport layer, and hole transport layer, see the section [First embodiment of organic electroluminescence element]. Furthermore, as the material for the cathode, in addition to the transparent conductive material used in the first embodiment, metals or alloys with a relatively small work function, such as aluminum, can be used.

[0098] On the other hand, the anode is made of a transparent material. Examples of transparent conductive materials that can be used for the anode include indium tin oxide (ITO), indium zinc oxide (IZO), ZnO, In2O3, and DIXO (In2O3-ZnO). The anode may also have a three-layer structure in which, from the organic light-emitting layer side, an auxiliary layer, a conductive layer, and an insulating layer are stacked. The auxiliary layer functions to assist the injection of holes from the anode into the intermediate layer. The auxiliary layer can be made of a material capable of adjusting the energy barrier between the conductive layer and the intermediate layer, such as a material with a lower HOMO (Highest Occupied Molecular Orbital) level than the layer of the intermediate layer adjacent to the auxiliary layer (e.g., the hole injection layer) or a material with a dipole. The auxiliary layer may also be composed of two layers: one layer made of a material with a lower HOMO level than the layer of the intermediate layer adjacent to the auxiliary layer, and the other layer made of a material with a dipole. Specific examples of materials for the auxiliary layer include tungsten oxide, fullerene, copper phthalocyanine, tetracyanoquinodimethane (TCNQ), triphenyltetrazolium chloride (TTC), naphthalenetetracarboxylic dianhydride (NTCDA), perylenetetracarboxylic dianhydride (PTCDA), and copper hexadecafluorophthalocyanine (F16CuPc). The conductive layer may be made of a good conductor such as silver, aluminum, chromium, samarium, or an alloy thereof, which can reduce the electrical resistance of the anode. The insulating layer has the function of adjusting the transmittance of light emitted from the organic electroluminescence element. For the insulating layer, for example, inorganic materials such as silicon oxide, silicon nitride, molybdenum oxide, and tungsten oxide, and organic materials such as tris(8-quinolinolato)aluminum (Alq3) can be used. Among these, tungsten oxide has particularly high light transmittance, so by using it, the transparency of the anode can be increased. Here, the thickness of the auxiliary layer is preferably 5 to 40 nm, more preferably 5 to 10 nm. The thickness of the conductive layer is preferably 8 to 24 nm, more preferably 16 to 24 nm. However, when emphasis is placed on light transmittance, the thickness of the conductive layer is more preferably 8 to 16 nm. The thickness of the insulating layer is preferably 30 to 80 nm.

[0099] Furthermore, in the organic electroluminescent element of the second embodiment, a transparent protective layer may be provided between the anode and the organic light-emitting layer. The transparent protective layer is provided, for example, between the anode and the hole injection layer or the hole transport layer. As a result, after the transparent protective layer is formed, the organic light-emitting layer and the like are protected by the transparent protective layer, thereby preventing the organic light-emitting layer and the like from being deteriorated due to the effects of subsequent processes. Metal oxides can be used as the material for the transparent protective layer, and it is preferable to use metal oxides in an oxygen-deficient state, such as molybdenum oxide (hexavalent), rhenium oxide (hexavalent), or nickel oxide (divalent). The transparent protective layer may also be patterned. For the pattern, dimensions, and patterning method when the transparent protective layer is patterned, see the section on (Transparent Protective Layer) in the organic electroluminescent element of the first embodiment. Furthermore, the organic electroluminescent element of the second embodiment may have an auxiliary electrode on the anode. This reduces the electrical resistance of the element, thereby lowering the driving voltage. For a description of the auxiliary electrode, its preferred range, and specific examples of materials, please refer to the section on (auxiliary electrode) in the organic electroluminescent element of the second embodiment. In the organic electroluminescent element of the second embodiment, when an electric field is applied between the anode and cathode, holes and electrons injected from each electrode recombine in the organic light-emitting layer, causing the light-emitting material to enter an excited state. The light emitted from the excited light-emitting material is then emitted to the outside, causing the organic electroluminescent element to emit light. In the organic electroluminescent element of the second embodiment, the anode disposed on the side opposite the substrate is transparent, so that light emitted by the light-emitting material is emitted from the anode side (the side opposite the substrate). Since the anode side does not have wiring or drive elements like those formed on the substrate, it has a high aperture ratio and can achieve high light extraction efficiency.

[0100] Each layer constituting the organic electroluminescent element of the first and second embodiments can be formed by depositing the corresponding material. The deposition method is not particularly limited, and may be either a dry process or a wet process. Specific examples include vapor deposition, sputtering, spin coating, printing, inkjet printing, and aerosol jet printing.

[0101] (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).

[0102] (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.

[0103] (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.

[0104] (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.

[0105] 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.

[0106] 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.

[0107] 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.

[0108] 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.

[0109] 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.

[0110] 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.

[0111] (Method for evaluating the luminescence performance of films) The present invention also provides a method for evaluating the luminescent performance of a film containing an organic compound. The film to be evaluated by the evaluation method of the present invention is a film containing a first organic compound, a second organic compound, and a third organic compound that satisfy the above formulas (a) to (c). The evaluation takes into consideration the S value of the third organic compound in the film and the half-width of the emission spectrum of the third organic compound. The half-width of the emission spectrum here refers to the half-width of the emission peak intended for use as light emission. It is usually the half-width of the emission peak having the maximum emission intensity, and preferably the half-width of the emission peak having the maximum emission intensity in the visible region. The S value and half-width may be values ​​actually measured prior to evaluation, or may be values ​​calculated as a result of calculation. In the evaluation, a film with as small an S value and as narrow a half-width as possible can be evaluated as having high light-emitting performance. For example, an S value of -0.38 or less and a half-width of 31 nm or less can be judged to have good luminous performance; an S value of -0.39 or less and a half-width of 30 nm or less can be judged to have good luminous performance; an S value of -0.40 or less and a half-width of 30 nm or less can be judged to have good luminous performance; an S value of -0.41 or less and a half-width of 23 nm or less can be judged to have better luminous performance; an S value of -0.42 or less and a half-width of 23 nm or less can be judged to have even better luminous performance; and an S value of -0.42 or less and a half-width of 20 nm or less can be judged to have even better luminous performance. The evaluation method of the present invention may also take into consideration a third index other than the S value and half-width. In one embodiment of the present invention, luminous performance is evaluated using only the S value and half-width as indices. By implementing the evaluation method of the present invention, the usefulness (particularly luminous performance) of a luminescent layer of an organic electroluminescent device can be evaluated. In particular, the usefulness (especially the light-emitting performance) of the film as a light-emitting layer in a top-emission organic electroluminescence device can be evaluated. At this time, specific values ​​related to light-emitting performance, such as external quantum yield, may be predicted. The accuracy of the prediction can be improved by accumulating the relationship between predicted values ​​and actual measured values ​​and appropriately correcting the calculation method for the predicted values. The evaluation method of the present invention can also be used to determine the superiority or inferiority of multiple films. By using the film evaluation method of the present invention, the light-emitting performance of a film can be preliminarily evaluated before the device is fabricated. Therefore, before mounting the film on a top-emission organic electroluminescent device and conducting costly and time-consuming tests, films with high preliminary evaluations can be selected, thereby narrowing down the number of mounting tests. Furthermore, the film evaluation method of the present invention can also be applied to films that have already been mounted. If the evaluation results of an mounted film using the evaluation method of the present invention are good, then incorporating the same film into a top-emission organic electroluminescent device can provide a device with even higher light-emitting performance. Therefore, the film evaluation method of the present invention has a wide range of applications.

[0112] (Method for determining conditions suitable for film formation) The present invention also provides a method for determining conditions suitable for film formation, particularly for forming an emitting layer of an organic electroluminescent device, particularly for forming an emitting layer of a top-emission organic electroluminescent device. The method for determining conditions suitable for film formation according to the present invention will be described with reference to FIG. 9, which illustrates a typical example. In the method of the present invention, a film containing a first organic compound, a second organic compound, and a third organic compound satisfying the above formulas (a) to (c) is first formed under certain conditions, and the S value and half-width of the emission spectrum of the third organic compound in the formed film are measured (S1). Next, a film containing the first organic compound, the second organic compound, and the third organic compound is formed under conditions different from the previous conditions, and the S value and half-width of the emission spectrum of the third organic compound in the formed film are measured (S2). The conditions to be changed are not particularly limited as long as they relate to the manufacturing conditions. For example, conditions such as temperature and film formation rate may be changed, or environmental control conditions over time may be changed. The conditions to be changed are preferably conditions that affect the S value and half-width. After performing step S2, it is determined whether to repeat step S2 (S3). If repeating step S2 is selected, a film is formed using conditions different from the previous conditions, and the S value and half-width are measured (S2). However, the material types of the first organic compound, the second organic compound, and the third organic compound that make up the film are not changed. After repeating step S2 as many times as necessary, the conditions suitable for film formation are determined by evaluating each condition using the measured S value and half-width as indicators (S4). The conditions suitable for film formation may be determined by selecting from the conditions that have actually been evaluated, or they may be determined as newly designed conditions through such evaluation. According to the method of determining conditions suitable for film formation of the present invention, it is possible to narrow down desirable manufacturing conditions in advance before fabricating an actual device. Furthermore, by using the method of the present invention, it is possible to find conditions for forming a film with good light-emitting performance. Furthermore, it is possible to provide a method for designing an organic electroluminescence device using the conditions determined by the method of the present invention.

[0113] The present invention also provides a program for implementing the method of the present invention for determining conditions suitable for film formation, and a program for designing an organic electroluminescent device using the method. The program can be stored on a recording medium and can also be transmitted and received electronically. Data on film formation conditions, S values, and half-widths accumulated by the method of the present invention can be saved as a database and used. In addition, actual measurements of actual films and organic electroluminescent devices can also be accumulated in the database and used to improve the accuracy of the evaluation method. These methods and programs can be appropriately modified in ways that are obvious to those skilled in the art. [Example]

[0114] The features of the present invention will be explained in more detail below with reference to examples. The materials, processing details, processing procedures, etc. shown 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 luminescence 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 lowest excited singlet energy E of the compounds used below was S1 , the lowest excited triplet energy E T1 , HOMO energy E HOMO , LUMO energy E LUMO is as shown in the table below.

[0115] [Table 1]

[0116] (Fabrication of bottom-emission organic electroluminescence devices) 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, HIO1 was formed on the ITO substrate to a thickness of 10 nm, and then EB1 was formed on top of that to a thickness of 10 nm. 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. Next, HB1 was formed to a thickness of 10 nm, followed by a 30 nm thick layer of ET1 and Liq (weight ratio 70:30). Liq was then formed to a thickness of 2 nm, and then aluminum (Al) was evaporated to a thickness of 100 nm to form a cathode. This resulted in the fabrication of a bottom-emission organic electroluminescent device.

[0117] (Fabrication of top-emission organic electroluminescence devices) Separately, on a 2 mm thick glass substrate on which a multilayer transparent anode made of indium tin oxide (ITO) with a film thickness of 10 nm and silver palladium copper alloy (APC) with a film thickness of 150 nm was formed, each thin film was deposited by vacuum deposition at a vacuum degree of 1×10 -6 The layers were laminated using a Pa process. First, HIO1 was deposited on the ITO substrate to a thickness of 10 nm, and then EB1 was deposited on top of that to a thickness of 10 nm. 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. Next, HB1 was deposited to a thickness of 10 nm, followed by a 30 nm-thick layer of ET1:Liq (weight ratio the same as for the bottom-emission system), and then a 2 nm-thick layer of Liq. Next, a 15 nm-thick cathode was formed by evaporating Mg:Ag (weight ratio 1:10), and then a 105 nm-thick cap layer was formed by evaporating NPD. This resulted in the fabrication of a top-emission organic electroluminescent device.

[0118] (Materials used) In the above-described procedure for producing a bottom-emission organic electroluminescence element, light-emitting layers 1 to 6 having the compositions shown in Table 2 below were formed, thereby producing bottom-emission organic electroluminescence elements BE1 to BE6. Furthermore, in the above-mentioned procedure for producing a top-emission organic electroluminescence element, top-emission organic electroluminescence elements TE1 to TE6 were produced by forming light-emitting layers 1 to 6 having the compositions shown in Table 2 below. All of the fabricated elements satisfy formulas (a) to (c). [Table 2]

[0119] (Evaluation results) The S value and full width at half maximum (FWHM) of the spectrum of the third organic compound in the emitting layer of each fabricated device were measured. The external quantum yield (EQE) and emission peak intensity of each fabricated organic electroluminescent device were also measured. The ratio of the external quantum yield and emission peak intensity (TE / BE) between top-emitting devices and bottom-emitting devices was calculated for devices with the same emitting layer. Figure 3 shows the relationship between the external quantum yield (EQE) of the top-emitting devices TE1 to TE6 and the full width at half maximum (FWHM) of the spectrum of the third organic compound. Figure 4 shows the relationship between the emission peak intensity (PI) of the top-emitting devices TE1 to TE6 and the full width at half maximum (FWHM) of the spectrum of the third organic compound. Figures 3 and 4 show that the graphs bend at a full width at half maximum (FWHM) of 31 nm. This indicates that the external quantum yield (EQE) and emission peak intensity (PI) of the top-emitting devices are significantly improved when the full width at half maximum (FWHM) is 31 nm or less. Figure 5 shows the relationship between the external quantum yield (EQE) and the S value of the third organic compound in the light-emitting layer of the top-emitting devices TE1 to TE6. Figure 6 shows the relationship between the peak emission intensity (PI) and the S value of the third organic compound in the light-emitting layer of the top-emitting devices TE1 to TE6. Figures 5 and 6 indicate that the curve bends at an S value of -0.38. This indicates that the external quantum yield (EQE) and peak emission intensity (PI) of the top-emitting devices are significantly improved when the S value is -0.38 or less. The ratio of the emission peak intensity between the top-emitting and bottom-emitting devices was high, ranging from 1.84 to 2.03, confirming that the top-emitting devices had higher emission peak intensities. Meanwhile, the ratio of the external quantum yield between the top-emitting and bottom-emitting devices was high, exceeding 1, for devices with emitting layers 3 and 6 that had an S value of -0.38 or less and a full width at half maximum of 31 nm or less (TE3 / BE3 = 1.10, TE6 / BE6 = 1.24). Conversely, devices with emitting layers that did not meet the conditions of an S value of -0.38 or less and a full width at half maximum of 31 nm or less showed values ​​below 1 (TE1 / BE1 = 0.77, TE4 / BE4 = 0.82, TE5 / BE5 = 0.94). From the above, it was confirmed that by forming an emitting layer in which the S value of the third organic compound is -0.38 or less and the half-width of the emission spectrum is 31 nm or less as the emitting layer of a top-emission organic electroluminescent element, in particular, it is possible to improve both the emission peak intensity and the luminous efficiency.

[0120] To clarify the mechanism behind the excellent effects of the present invention, we calculated the evanescent modes of the top-emission devices TE1 to TE6. The evanescent modes were calculated using mode analysis software Setfos (manufactured by Cybernet Corporation) based on film thickness information and optical constants. Figure 7 shows the relationship between the evanescent modes of the top-emission devices TE1 to TE6 and the full width at half maximum (FWHM) of the spectrum of the third organic compound. Figure 8 shows the relationship between the evanescent modes of the top-emission devices TE1 to TE6 and the S value of the third organic compound in the light-emitting layer. While no correlation was observed between the evanescent modes and the full width at half maximum (FWHM), a tendency was observed for the evanescent modes to increase as the S value decreased. This tendency is thought to be due to the fact that when the molecules of the third organic compound are horizontally aligned in the light-emitting layer, reducing the S value, the generation of plasmons is suppressed, thereby reducing metal loss. Reducing metal loss increases the proportion of extractable excitons. Furthermore, if the third organic compound is horizontally aligned, the total reflection angle also decreases, and therefore a smaller S value is thought to improve light extraction efficiency. On the other hand, although the full width at half maximum (FWHM) is not involved in suppressing metal loss, a narrower full width at half maximum (FWHM) increases the photon number density in the peak wavelength region for a given number of emitted photons. Therefore, narrowing the full width at half maximum increases the number of photons in the wavelength region allowed by the cavity film thickness, leading to improved luminance. In the present invention, the effects of narrowing the full width at half maximum and reducing the S value (increasing orientation) are synergistically enhanced in the region where the full width at half maximum of the emission spectrum is 31 nm or less and the S value is -0.38 or less, resulting in a significant improvement in luminance efficiency.

[0121] [ka] [Industrial Applicability]

[0122] The top-emission organic electroluminescent device of the present invention has high luminous efficiency. According to the method of the present invention, the luminous performance of a film can be easily evaluated, and the conditions for forming a light-emitting layer with good luminous performance can be accurately determined, allowing for the design of an excellent organic electroluminescent device. Furthermore, by utilizing the program and database of the present invention, evaluation and design can be carried out efficiently. Therefore, the present invention is practical and has high industrial applicability. [Explanation of symbols]

[0123] 1 board 2a Anode (1st electrode) 2b Cathode (1st electrode) 3. Hole injection layer 4. Hole transport layer 5. Organic light-emitting layer 6 Electron transport layer 7 Electron injection layer 8 Transparent protective layer 9 Transparent conductive layer (second electrode)

Claims

1. A top-emission organic electroluminescence element having a laminated structure having a substrate, a first electrode, a light-emitting layer, and a transparent second electrode in this order, The light-emitting layer contains a first organic compound, a second organic compound, and a third organic compound that satisfy the following formulas (a) to (c): The second organic compound is a delayed fluorescent material represented by the following general formula (2): The third organic compound is a compound represented by the following general formula (15): General formula (2) 【Chemistry 1】 [In the general formula (1), X １ ~X ５ represents N or C—R. R represents a hydrogen atom, a deuterium atom, or a substituent. X １ ~X ５ When two or more of X represent C—R, those C—R may be the same or different from each other. １ ~X ５ Among these, two to five are CD (where D represents a donor group represented by general formula (4)), and these two to five CDs are the same.] General formula (4) 【Chemistry 2】 [In general formula (4), R ５１ ~R ６０ each independently represents a hydrogen atom, a deuterium atom, or a substituent. １２ represents a single bond, a substituted or unsubstituted arylene group, or a substituted or unsubstituted heteroarylene group. 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 may be bonded to each other to form a cyclic structure. General formula (15) 【Transformation 3】 [In the general formula (15), 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, and the rings may be fused. ２ has a structure in which two benzene rings are linked together by a boron atom and a nitrogen atom to form a 9-aza-10-boraanthracene ring. ａ and R ａ Each of R' independently represents a substituent. 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. the S value of the third organic compound in the light-emitting layer is −0.38 or less, and the S value is a value obtained by forming a film of the third organic compound to a thickness of 15 nm on a quartz substrate, irradiating the film with laser light, measuring the angle dependency of P polarization of the film, and calculating the S value from ½ <3cos2θ−1>, where θ is the angle between the normal to the substrate and the transition dipole of the third organic compound; an organic electroluminescence device, wherein the third organic compound has an emission spectrum with a half-width of 26 nm or less; 【change】 [where: E Ｓ１ (1) is the lowest excited singlet energy of the first organic compound E Ｓ１ (2) is the lowest excited singlet energy of the second organic compound E Ｓ１ (3) is the lowest excited singlet energy of the third 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 E HOMO (2) is the HOMO energy of the second organic compound E HOMO (3) represents the HOMO energy of the third organic compound.

2. The organic electroluminescence device according to claim 1 , wherein recombination of holes and electrons occurs in the light-emitting layer.

3. A method for evaluating the luminescence performance of a film containing a first organic compound satisfying the following formulas (a) to (c), a second organic compound represented by the following general formula (2), and a third organic compound represented by the following general formula (15), General formula (2) 【Chemistry 4】 [In general formula (2), X 1 to X 5 represent N or C-R. R represents a hydrogen atom, a deuterium atom, or a substituent. When two or more of X 1 to X 5 represent C-R, those C-Rs may be the same or different. However, two to five of X 1 to X 5 are C-D (here, D represents a donor group represented by general formula (4)), and these two to five C-Ds are the same.] General formula (4) 【Transformation 5】 [In general formula (4), R 51 to R 60 each independently represent a hydrogen atom, a deuterium atom, or a substituent. L 12 represents a single bond, a substituted or unsubstituted arylene group, or a substituted or unsubstituted heteroarylene group. 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 , and R 59 and R 60 may be bonded to each other to form a cyclic structure.] General formula (15) 【Transformation 6】 [In general formula (15), Ar 1 to Ar 3 each independently represent 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. However, Ar 2 has a structure in which two benzene rings are linked to each other via a boron atom and a nitrogen atom to form a 9-aza-10-boraanthracene ring. R a and R a ' each independently represent a substituent. R a and Ar 1 , Ar 1 and Ar 2 , Ar 2 and R a ', R a ' and Ar 3 , and Ar 3 and R a may be bonded to each other to form a cyclic structure.] A method for evaluating the luminous performance of a film using the S value of the third organic compound and the half-width of the luminescence spectrum of the third organic compound as indicators (the S value here is a value obtained by forming a 15 nm thick film of the third organic compound on a quartz substrate, irradiating it with laser light, and measuring the angle dependency of the P deflection of the film, and then calculating 1 / 2 <3cos2θ-1>, where θ is the angle between the normal to the substrate and the transition dipole of the third organic compound). 【change】 [where: E Ｓ１ (1) is the lowest excited singlet energy of the first organic compound E Ｓ１ (2) is the lowest excited singlet energy of the second organic compound E Ｓ１ (3) is the lowest excited singlet energy of the third 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 E HOMO (2) is the HOMO energy of the second organic compound E HOMO (3) represents the HOMO energy of the third organic compound. represent.]

4. The method according to claim 3, wherein the evaluation is performed based on the criteria that the half-width is 26 nm or less and the S value is −0.38 or less.

5. The method according to claim 3 or 4, wherein the usefulness of the compound as a light-emitting layer of a top-emission organic electroluminescence device is evaluated.

6. The method of claim 5 , wherein the luminous efficiency of the device is predicted.

7. The method according to any one of claims 3 to 6, wherein the merits of a plurality of films are evaluated.

8. A film containing a first organic compound satisfying the following formulas (a) to (c), a second organic compound represented by the following general formula (2), and a third organic compound represented by the following general formula (15) is formed under certain conditions; General formula (2) 【Transformation 7】 [In general formula (2), X 1 to X 5 represent N or C-R. R represents a hydrogen atom, a deuterium atom, or a substituent. When two or more of X 1 to X 5 represent C-R, those C-Rs may be the same or different. However, two to five of X 1 to X 5 are C-D (here, D represents a donor group represented by general formula (4)), and these two to five C-Ds are the same.] General formula (4) 【Transformation 8】 [In general formula (4), R 51 to R 60 each independently represent a hydrogen atom, a deuterium atom, or a substituent. L 12 represents a single bond, a substituted or unsubstituted arylene group, or a substituted or unsubstituted heteroarylene group. 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 , and R 59 and R 60 may be bonded to each other to form a cyclic structure.] General formula (15) 【Chemistry 9】 [In general formula (15), Ar 1 to Ar 3 each independently represent 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. However, Ar 2 has a structure in which two benzene rings are linked to each other via a boron atom and a nitrogen atom to form a 9-aza-10-boraanthracene ring. R a and R a ' each independently represent a substituent. R a and Ar 1 , Ar 1 and Ar 2 , Ar 2 and R a ', R a ' and Ar 3 , and Ar 3 and R a may be bonded to each other to form a cyclic structure.] the S value and half width of the emission spectrum of the third organic compound in the formed film are measured, the S value being a value obtained by forming a film of the third organic compound to a thickness of 15 nm on a quartz substrate, irradiating it with laser light, measuring the angle dependency of P polarization of the film, and calculating the S value from 1 / 2 <3cos2θ-1>, where θ is the angle between the normal to the substrate and the transition dipole of the third organic compound; forming a film containing the first organic compound, the second organic compound, and the third organic compound under conditions different from the above conditions, and measuring the S value and half width of the emission spectrum of the third organic compound in the formed film, and repeating this process one or more times; A method for determining conditions suitable for film formation by evaluating the S value and the half-width as indicators. 【change】 [where: E Ｓ１ (1) is the lowest excited singlet energy of the first organic compound E Ｓ１ (2) is the lowest excited singlet energy of the second organic compound E Ｓ１ (3) is the lowest excited singlet energy of the third 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 E HOMO (2) is the HOMO energy of the second organic compound E HOMO (3) represents the HOMO energy of the third organic compound.

9. The method according to claim 8 , wherein the determination is made after newly designing conditions suitable for the film formation based on the evaluation.

10. A method for designing an organic electroluminescence device, comprising forming a light-emitting layer under conditions determined by the method according to claim 8 or 9.

11. A program for implementing the method of claim 8 or 9 or the design of claim 10.

12. A database storing data on the conditions, S values, and half-widths according to claim 8.

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