Design method and program for organic electroluminescent elements and light-emitting compositions

Abstract

To provide an organic electroluminescent element having a low driving voltage and high luminous efficiency.SOLUTION: In an organic electroluminescent device having a light-emitting layer containing first to third compounds satisfying the following formulas. ES1(m) is the lowest excited singlet energy of the m-th compound, and ELUMO(n) is the LUMO energy of the n-th compound (m, n=1 to 3). ES1(1)>ES1(2)>ES1(3). ELUMO(2)≤ELUMO(3).SELECTED DRAWING: None

Description

[Technical Field]

[0001] This invention relates to an organic electroluminescent element characterized by a light-emitting layer, a method for designing a light-emitting composition, and a program for it. [Background technology]

[0002] Research is actively being conducted to improve the luminescence efficiency of light-emitting devices such as organic electroluminescent devices (OLEDs). In particular, various methods are being employed to improve luminescence efficiency by newly developing and combining electron transport materials, hole transport materials, and light-emitting materials that constitute organic electroluminescent devices. Among these, there is also research on organic electroluminescent devices that utilize delayed fluorescence materials.

[0003] Delayed fluorescence materials are materials that, in their excited state, emit fluorescence when they return from the excited singlet state to the ground state after undergoing a reverse intersystem crossover from the excited triplet state to the excited singlet state. This fluorescence is called delayed fluorescence because it is observed later than fluorescence directly generated from the excited singlet state (normal fluorescence) from the ground state. For example, when a luminescent compound is excited by carrier injection, the probability of generating the excited singlet state and the excited triplet state is statistically 25%:75%, so there is a limit to improving the luminescence efficiency if only fluorescence from the directly generated excited singlet state is used. On the other hand, with delayed fluorescence materials, not only the excited singlet state but also the excited triplet state can be used for fluorescence emission via the reverse intersystem crossover pathway described above, resulting in higher luminescence efficiency compared to normal fluorescence materials.

[0004] After the properties of such delayed fluorescence materials were clarified, various methods for effectively using delayed fluorescence materials in organic electroluminescent devices have been investigated. For example, Patent Document 1 describes adding a delayed fluorescence material, whose lowest excitation singlet energy is lower than that of the host material but higher than that of the luminescent material, to a light-emitting layer containing a light-emitting material and a host material. By adding such a delayed fluorescence material, the lowest excitation singlet energy of the delayed fluorescence material is transferred to the light-emitting material, which can improve the luminescence efficiency of the light-emitting material. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Patent No. 5669163 [Overview of the Initiative] [Problems that the invention aims to solve]

[0006] By adding a delayed fluorescence material, whose minimum excitation singlet energy is lower than that of the host material but higher than that of the luminescent material, to a light-emitting layer containing a light-emitting material and a host material, the luminescence efficiency of the organic electroluminescent element can indeed be improved. However, organic electroluminescent elements with delayed fluorescence materials added to the light-emitting layer in this manner tend to have a high driving voltage, and there is room for improvement in terms of practicality. Therefore, there is a need to provide an organic electroluminescent element that achieves high luminescence efficiency while suppressing the driving voltage. [Means for solving the problem]

[0007] In order to solve the problems of the conventional technology, the inventors diligently conducted research and found that by selecting and combining compounds used in the light-emitting layer of an organic electroluminescent element to satisfy specific conditions, it is possible to achieve high luminous efficiency while suppressing the driving voltage. The present invention is proposed based on this finding and specifically has the following configuration.

[0008] [1] An organic electroluminescent element having an anode, a cathode, and at least one organic layer including a light-emitting layer between the anode and the cathode, The light-emitting layer comprises a first organic compound, a second organic compound, and a third organic compound. The second organic compound is a delayed fluorescence material, The largest component of the light emitted from the element is the light emitted from the third organic compound. An organic electroluminescent element in which the first organic compound, the second organic compound, and the third organic compound satisfy the following formulas (a) and (b).

number

number

[10] R 1 ~R 9An organic electroluminescent element according to any one of [5] to [8], wherein the number of substituents present in the element with a Hammett σp value of less than -0.2 is three or more.

[11] An organic electroluminescent element according to any one of [1] to

[10] , wherein the second organic compound is a compound represented by the following general formula (3). [ka] [Here, R 21 ~R 23 One of them represents a cyano group or a group represented by the following general formula (4), R 21 ~R 23 The remaining two and R 24 and R 25 At least one of them independently represents a group represented by the following general formula (5), R 21 ~R 25 The remaining elements each independently represent a hydrogen atom or a substituent (however, the substituents referred to here are not cyano groups, groups represented by general formula (4) below, or groups represented by general formula (5) below). [ka] [Here, L 1 represents a single bond or a divalent linking group, R 31 and R 32 Each of the symbols represents an independent hydrogen atom or substituent, and * represents a bond position. [ka] [Here, L 2 represents a single bond or a divalent linking group, R 33 and R 34 Each of the symbols represents an independent hydrogen atom or substituent, and * represents a bond position.

[12] In the above general formula (3), R 21 ~R 23 The organic electroluminescent element described in

[11] , wherein one of the groups is represented by the general formula (4).

[13] In the above general formula (3), R 21 and R 22The organic electroluminescent element according to

[11] or

[12] , wherein one of the groups is a cyano group or a group represented by the general formula (4).

[14] An organic electroluminescent element according to any one of

[11] to

[13] , wherein the general formula (5) is a group represented by the following general formula (6). [ka] [Here, L 11 represents a single bond or a divalent linking group, R 41 ~R 48 Each of the symbols represents an independent hydrogen atom or substituent, and * represents a bond position. 41 ~R 48 Each carbon atom to which it is bonded may be independently substituted with a nitrogen atom.

[15] An organic electroluminescent element according to any one of

[11] to

[13] , wherein the general formula (5) is a group represented by any one of the following general formulas (7) to (12). [ka] [Here, L 21 ~L 26 represents a single bond or a divalent linking group, R 51 ~R 110 Each of these independently represents a hydrogen atom or a substituent, X 1 ~X 6 represents an oxygen atom, a sulfur atom, or NR, R represents a hydrogen atom or substituent, and * represents a bond position. 51 ~R 110 Each carbon atom to which it is bonded may be independently substituted with a nitrogen atom.

[16] An organic electroluminescent element according to any one of [1] to

[15] , wherein the light-emitting layer contains carbon atoms, hydrogen atoms, nitrogen atoms, boron atoms, oxygen atoms, and fluorine atoms, but does not contain any other elements.

[17] [Step 1] Evaluate the luminescence efficiency and driving voltage of a composition comprising a first organic compound, a second organic compound which is a delayed fluorescence material, and a third organic compound, satisfying the following formulas (a) and (b), [Step 2] At least once, evaluate the luminous efficiency and driving voltage of compositions in which at least one of the first organic compound, the second organic compound which is a delayed fluorescence material, and the third organic compound is replaced within the range that satisfies the following formulas (a) and (b). [Step 3] Select the best compound combination based on the evaluated luminous efficiency and driving voltage. A method for designing a light-emitting composition, including each step.

number

[18]

[17] . [Effects of the Invention]

[0009] The organic electroluminescent element of the present invention can achieve high luminescence efficiency with a low driving voltage. According to the design method for the light-emitting composition of the present invention, it is possible to provide a light-emitting composition that can realize a light-emitting element with low driving voltage and high luminescence efficiency. [Brief explanation of the drawing]

[0010] [Figure 1] This is a schematic cross-sectional view showing an example of the layer structure of an organic electroluminescent element. [Figure 2]This graph shows the relationship between the LUMO energy difference ΔELUMO between the second and third organic compounds of electron mobility measurement devices 1-3 and the REM ratio of electron mobility with and without the third organic compound. [Modes for carrying out the invention]

[0011] The present invention will be described in detail below. The following descriptions of constituent elements may be based on representative embodiments and specific examples of the present invention, but the present invention is not limited to such embodiments and specific examples. In this specification, numerical ranges represented by "~" mean a range that includes the numbers written before and after "~" as the lower and upper limits. Furthermore, the isotopes of hydrogen atoms present in the molecule of the compound used in the present invention are not particularly limited; for example, all hydrogen atoms in the molecule 1 H is fine, or part or all of it 2 It may also be H (deuterium D). In a preferred embodiment of the present invention, all hydrogen atoms in the molecule 1 It is H. In one aspect of the present invention, all hydrogen atoms in the molecule 2 It is H (deuterium D). In one aspect of the present invention, some of the hydrogen atoms in the molecule are 1 H, and the rest is 2 It is H (deuterium D). Note that in the description of this invention, the terms "substitution" or "substituent" are used in the following context: 2 H (Deuterium D), etc. 1 It does not contain hydrogen isotopes other than H.

[0012] (Organic electroluminescent element) The organic electroluminescent element of the present invention has an anode, a cathode, and at least one organic layer including a light-emitting layer between the anode and the cathode. The light-emitting layer comprises a first organic compound, a second organic compound, and a third organic compound, the second organic compound being a delayed fluorescence material, and the maximum component of light emission from the organic light-emitting element being light emission from the third organic compound. The first organic compound, the second organic compound, and the third organic compound satisfy the following formulas (a) and (b).

number

[0013] E in equation (a) S1 (1) represents the lowest singlet excitation energy of the first organic compound, E S1 (2) represents the lowest singlet excitation energy of the second organic compound, E S1 (3) represents the lowest singlet excitation energy of the third organic compound. In this invention, eV is used as the unit. The lowest singlet excitation energy is measured in a thin film or toluene solution (concentration 10) of the compound to be measured. -5 This can be determined by preparing a mol / L solution and measuring the fluorescence spectrum at room temperature (300K) (for details, see the method for measuring the lowest excitation singlet energy in the description of the second organic compound).

[0014] Since the present invention satisfies the relationship of formula (a), among the first organic compound, second organic compound, and third organic compound contained in the light-emitting layer, the first organic compound has the largest lowest excitation singlet energy, the second organic compound has the next largest, and the third organic compound has the smallest. S1 (1)-E S1 (2) can be set to a range of 0.20 eV or more, 0.40 eV or more, 0.60 eV or more, and also to a 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 set to a range of 0.05 eV or more, 0.10 eV or more, 0.15 eV or more, and also to a 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 set to a range of 0.25 eV or more, 0.45 eV or more, or 0.65 eV or more, and can also be set to a range of 2.00 eV or less, 1.70 eV or less, or 1.30 eV or less.

[0015] E in equation (b) LUMO (2) represents the LUMO energy of the second organic compound, 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 (e.g., AC-3, manufactured by RIKEN SEKI Co., Ltd.). Since the present invention satisfies the relationship in formula (b), the LUMO energy of the second organic compound contained in the light-emitting layer is less than or equal to the LUMO energy of the third organic compound. LUMO energy difference [E LUMO (3)-E LUMO (2) can be, for example, in the range of 0.05 eV or more, in the range of 0.10 eV or more, in the range of 0.13 eV or more, and can also be in the range of 0.40 eV or less, in the range of 0.30 eV or less, or in the range of 0.20 eV or less. In one aspect of the present invention, the second organic compound can be a compound in the range of -3.40 to -3.70 eV or a compound in the range of -3.50 to -3.60 eV. In another aspect of the present invention, the third organic compound can be a compound with a LUMO energy greater than -3.50, a compound in the range of -3.51 to -3.25 eV or a compound in the range of -3.45 to -3.35 eV.

[0016] When the content of the first organic compound, the second organic compound, and the third organic compound in the light-emitting layer of the organic light-emitting device of the present invention are Conc(1), Conc(2), and Conc(3), respectively, it is preferable that the following relationship (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 99% by weight or less, 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 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, 0.3% by weight or more, and can also 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, 90 or more, and also in the range of 10000 or less, 1000 or less, or 200 or less. Conc(2) / Conc(3) can be set to a range of 5 or more, 10 or more, 20 or more, 30 or more, and also to a range of 500 or less, 300 or less, or 100 or less.

[0017] The light-emitting layer of the organic light-emitting device of the present invention preferably does not contain metal elements other than boron. For example, the light-emitting layer can be composed solely of compounds consisting of atoms selected from the group consisting of carbon atoms, hydrogen atoms, nitrogen atoms, oxygen atoms, sulfur atoms, fluorine atoms, and boron atoms.

[0018] (first organic compound) The first organic compound used in the light-emitting layer of the organic electroluminescent element of the present invention is selected from compounds having a lower minimum excitation singlet energy greater than that of the second and third organic compounds. The first organic compound preferably functions as a host material responsible for carrier transport. Furthermore, the first organic compound preferably has the function of confining the energy of the third organic compound within itself. This allows the third organic compound to efficiently convert the energy generated by the recombination of holes and electrons within the molecule, as well as the energy received from the first and second organic compounds, into light emission. The first organic compound is preferably an organic compound that has hole transport ability and electron transport ability, prevents the emission from becoming longer wavelengths, 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 electroluminescent element of the present invention, more preferably less than 0.1%, and may be, for example, less than 0.01% or below the detection limit. It is preferable that the first organic compound does not contain metal atoms. For example, the first organic compound can be a compound composed 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 can be a compound composed of atoms selected from the group consisting of carbon atoms, hydrogen atoms, nitrogen atoms, and oxygen atoms. For example, the first organic compound can be a compound composed of carbon atoms, hydrogen atoms, and nitrogen atoms. The following are some preferred compounds that can be used as the first organic compound.

[0019] [ka] JPEG0007829912000013.jpg241170JPEG0007829912000014.jpg80170

[0020] (Second organic compound) The second organic compound used in the light-emitting layer of the organic electroluminescent element of the present invention is a delayed fluorescence material that has a lower minimum excitation singlet energy than the first organic compound, a higher minimum excitation singlet energy than the third organic compound, and a lower LUMO energy than the third organic compound. In the present invention, a "delayed fluorescence material" is an organic compound that, in the excited state, undergoes a reverse intersystem crossing from the excited triplet state to the excited singlet state, and emits fluorescence (delayed fluorescence) when returning from the excited singlet state to the ground state. In the present invention, a delayed fluorescence material is defined as one in which fluorescence with an emission lifetime of 100 ns (nanoseconds) or more is observed when the emission lifetime is measured using a fluorescence lifetime measurement system (such as the Hamamatsu Photonics Streak Camera System). Although the second organic compound is a material that can emit delayed fluorescence, it is not essential that it emits delayed fluorescence originating from the second organic compound when used in the organic electroluminescent element of the present invention. The light emitted from the second organic compound is preferably less than 10% of the light emitted from the organic electroluminescent element 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 light-emitting device of the present invention, the second organic compound receives energy from the first organic compound in the excited singlet state and transitions to the excited singlet state. Alternatively, the second organic compound may receive energy from the first organic compound in the excited triplet state and transition to the excited triplet state. The second organic compound is the difference (ΔE) between the excited singlet energy and the excited triplet energy. ST Because the ) is small, the second organic compound in the excited triplet state readily crosses back into the excited singlet state of the second organic compound. The second organic compound in the excited singlet state, generated by these pathways, gives energy to the third organic compound, causing the third organic compound to transition to the excited singlet state.

[0021] The second organic compound is the difference ΔE between the lowest excited singlet energy and the lowest excited triplet energy at 77K. STIt is preferably 0.3 eV or less, more preferably 0.25 eV or less, still more preferably 0.2 eV or less, further more preferably 0.15 eV or less, still further more preferably 0.1 eV or less, even further more preferably 0.07 eV or less, even still more preferably 0.05 eV or less, even yet more preferably 0.03 eV or less, and particularly preferably 0.01 eV or less. ΔE ST If it is small, intersystem crossing from the singlet excited state to the triplet excited state is likely to occur due to the absorption of thermal energy, so the second organic compound functions as a thermally activated delayed fluorescence material. A thermally activated delayed fluorescence material can absorb the heat emitted by the device and relatively easily undergo intersystem crossing from the triplet excited state to the singlet excited state, and its triplet excitation energy can efficiently contribute to light emission.

[0022] In the present invention, the lowest singlet excitation energy (E S1 ) and the lowest triplet excitation energy (E T1 ) of the compound are values obtained by the following procedure. ΔE ST is a value obtained by calculating E S1 - E T1 . (1) Lowest singlet excitation energy (E S1 ) Prepare a thin film or toluene solution (concentration 10 -5 mol / L) of the compound to be measured as a sample. Measure the fluorescence spectrum of this sample at room temperature (300 K). The fluorescence spectrum has the emission on the vertical axis and the wavelength on the horizontal axis. Draw a tangent to the rising edge on the short wavelength side of this emission spectrum, and obtain the wavelength value λedge [nm] of the intersection of the tangent and the horizontal axis. The value obtained by converting this wavelength value into an energy value using the following conversion formula is E S1 . Conversion formula: E S1 [eV] = 1239.85 / λedge In the measurement of the emission spectrum in the embodiments described below, the detector (PMA-12 multi-channel spectroscope C10027-01, manufactured by Hamamatsu Photonics) was used with an LED light source (M300L4, manufactured by Thorlabs) as the excitation light source. (2) The same sample as that used in the measurement of the lowest excited triplet energy (E T1 ) is cooled to 77 [K] with liquid nitrogen, irradiated with excitation light (300 nm) on the phosphorescence measurement sample, and phosphorescence is measured using a detector. The emission from 100 milliseconds after the excitation light irradiation is taken as the phosphorescence spectrum. A tangent is drawn to the rising edge on the short wavelength side of this phosphorescence spectrum, and the wavelength value λedge [nm] at the intersection of the tangent and the horizontal axis is obtained. The value obtained by converting this wavelength value to an energy value using the following conversion formula is E S1 . T1 Conversion formula: E T1 [eV] = 1239.85 / λedge The tangent to the rising edge on the short wavelength side of the phosphorescence spectrum is drawn as follows. When moving along the spectrum curve from the short wavelength side of the phosphorescence spectrum to the maximum value on the shortest wavelength side among the maximum values of the spectrum, tangents at each point on the curve are considered in the long wavelength direction. As the curve rises (i.e., as the vertical axis increases), the slope of this tangent increases. The tangent drawn at the point where the value of this slope reaches the maximum is taken as the tangent to the rising edge on the short wavelength side of the phosphorescence spectrum. Note that the maximum points with peak intensities of 10% or less of the maximum peak intensity of the spectrum are not included in the maximum value on the shortest wavelength side described above, and the tangent drawn at the point closest to the maximum value on the shortest wavelength side where the value of the slope reaches the maximum is taken as the tangent to the rising edge on the short wavelength side of the phosphorescence spectrum.

[0023] In a preferred embodiment of the present invention, a compound represented by the following general formula (3) is used as the second organic compound.

Chemical formula

[0024] ​In general formula (3), R 21 ~R 23 One of them represents a cyano group or a group represented by the following general formula (4), R 21 ~R 23 The remaining two and R 24 and R 25 At least one of them represents a group represented by the following general formula (5), R 21 ~R 25 The remainder represents a hydrogen atom or a substituent (however, the substituent referred to here is not a cyano group, a group represented by general formula (4) below, or a group represented by general formula (5) below). [ka] In general formula (4), L 1 represents a single bond or a divalent linking group, R 31 and R 32 Each of the symbols represents an independent hydrogen atom or substituent, and * represents a bond position. [ka] In general formula (5), L 2 represents a single bond or a divalent linking group, R 33 and R 34 Each of the symbols represents an independent hydrogen atom or substituent, and * represents a bond position.

[0025] R 21 ~R 23 Among them, R 21 or R 22 It is preferable that is a cyano group or a group represented by general formula (4). In one preferred embodiment of the present invention, R 22 is a cyano group. In one preferred embodiment of the present invention, R 22 This is a group represented by general formula (4). In one aspect of the present invention, R 21 R is a cyano group or a group represented by general formula (4). In one aspect of the present invention, R 23 R is a cyano group or a group represented by general formula (4). In one aspect of the present invention, R 21 ~R 23 One of them is a cyano group. In one aspect of the present invention, R 21~R 23 One of these is the group represented by general formula (4).

[0026] In one preferred embodiment of the present invention, L in general formula (4) 1 It is a single bond. In one aspect of the present invention, L 1 The linking group is a divalent group, preferably a substituted or unsubstituted arylene group, or a substituted or unsubstituted heteroarylene group, more preferably a substituted or unsubstituted arylene group, and even more preferably a substituted or unsubstituted 1,4-phenylene group (with a substituent such as an alkyl group having 1 to 3 carbon atoms). In one aspect of the present invention, R in general formula (4) 31 and R 32 Each of these is independently one or more groups selected from the group consisting of alkyl groups (e.g., 1 to 40 carbon atoms), aryl groups (e.g., 6 to 30 carbon atoms), heteroaryl groups (e.g., 5 to 30 ring skeleton constituent atoms), alkenyl groups (e.g., 1 to 40 carbon atoms), and alkynyl groups (e.g., 1 to 40 carbon atoms) (hereinafter these groups are referred to as "substituent group A groups"). In a preferred embodiment of the present invention, R 31 and R 32 Each of these is independently a substituted or unsubstituted aryl group (e.g., having 6 to 30 carbon atoms), and examples of substituents on the aryl group include the groups of substituent group A. In a preferred embodiment of the present invention, R 31 and R 32 They are identical.

[0027] In one preferred embodiment of the present invention, L in general formula (5) 2 It is a single bond. In one aspect of the present invention, L 2 The linking group is a divalent group, preferably a substituted or unsubstituted arylene group, or a substituted or unsubstituted heteroarylene group, more preferably a substituted or unsubstituted arylene group, and even more preferably a substituted or unsubstituted 1,4-phenylene group (with a substituent such as an alkyl group having 1 to 3 carbon atoms). In one aspect of the present invention, R in general formula (5) 33 and R 34Each of these independently represents a substituted or unsubstituted alkyl group (e.g., 1-40 carbon atoms), a substituted or unsubstituted alkenyl group (e.g., 1-40 carbon atoms), a substituted or unsubstituted aryl group (e.g., 6-30 carbon atoms), or a substituted or unsubstituted heteroaryl group (e.g., 5-30 carbon atoms). Substituents for alkyl groups, alkenyl groups, aryl groups, and heteroaryl groups as used here include hydroxyl groups, halogen atoms (e.g., fluorine, chlorine, bromine, iodine atoms), alkyl groups (e.g., 1-40 carbon atoms), alkoxy groups (e.g., 1-40 carbon atoms), alkylthio groups (e.g., 1-40 carbon atoms), aryl groups (e.g., 6-30 carbon atoms), aryloxy groups (e.g., 6-30 carbon atoms), arylthio groups (e.g., 6-30 carbon atoms), heteroaryl groups (e.g., 5-30 carbon atoms in the ring skeleton), heteroaryloxy groups (e.g., 5-30 carbon atoms in the ring skeleton), and heteroarylthio groups. Examples of groups include one or more groups selected from the group consisting of oxy groups (e.g., 5-30 atoms in the ring skeleton), acyl groups (e.g., 1-40 carbon atoms), alkenyl groups (e.g., 1-40 carbon atoms), alkynyl groups (e.g., 1-40 carbon atoms), alkoxycarbonyl groups (e.g., 1-40 carbon atoms), aryloxycarbonyl groups (e.g., 1-40 carbon atoms), heteroaryloxycarbonyl groups (e.g., 1-40 carbon atoms), silyl groups (e.g., trialkylsilyl groups with 1-40 carbon atoms), nitro groups, and cyano groups (hereinafter, these groups will be referred to as "substituent group B groups"). R 33 and R 34 These may be linked to each other by single bonds or linking groups to form a cyclic structure. In particular, R 33 and R 34 If the group is an aryl group, it is preferable that they are bonded to each other via single bonds or linking groups to form a cyclic structure. The linking groups referred to here are -O-, -S-, and -N(R 35 )-,-C(R 36 )(R 37 We can list -, -C(=O)-, -O-, -S-, -N(R 35 )-,-C(R 36 )(R 37 )- is preferred, -O-, -S-, -N(R 35)- is more preferable. R 35 ~R 37 Each of these independently represents a hydrogen atom or a substituent. As substituents, groups from substituent group A above, substituent group B below, or substituent group C below can be selected, and preferably one group or a combination of two or more groups selected from the group consisting of alkyl groups having 1 to 10 carbon atoms and aryl groups having 6 to 14 carbon atoms.

[0028] The group represented by general formula (5) is preferably the group represented by general formula (6) below. [ka]

[0029] The compound represented by general formula (6) is more preferably a compound represented by any of the following general formulas (7) to (12). [ka]

[0030] In general formulas (6) to (12), L 11 and L 21 ~L 26 L represents a single bond or a divalent linking group. 11 and L 21 ~L 26 For an explanation and preferred range, see L above. 2 You can refer to the explanation and preferred range. In general formulas (6) to (12), R 41 ~R 110 Each of these 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 R48 , 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 75 and 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 110 These rings may bond to each other to form a cyclic structure. The cyclic structure formed by the bonding may be an aromatic ring or an antilipid ring, and may contain heteroatoms. Furthermore, the cyclic structure may be a fused ring of two or more rings. The heteroatoms referred to here are preferably selected from the group consisting of nitrogen atoms, oxygen atoms, and sulfur atoms. Examples of the cyclic structures formed include benzene rings, naphthalene rings, pyridine rings, pyridazine rings, pyrimidine rings, pyrazine rings, pyrrole rings, imidazole rings, pyrazole rings, imidazoline rings, oxazole rings, isoxazole rings, thiazole rings, isothiazole rings, cyclohexadiene rings, cyclohexene rings, cyclopentaene rings, cycloheptatriene rings, cycloheptadiene rings, cycloheptaene rings, furan rings, thiophene rings, naphthyridine rings, quinoxaline rings, and quinoline rings. For example, a ring formed by the fusion of multiple rings, such as a phenanthrene ring or a triphenylene ring, may also be formed. The number of rings in the group represented by general formula (6) may be selected from 3 to 5, or from 5 to 7. The number of rings in the groups represented by general formulas (7) to (12) may be selected from 5 to 7, or it may be 5. R41 ~R 110 Examples of substituents that can be adopted include the groups of substituent group B above, preferably an unsubstituted alkyl group having 1 to 10 carbon atoms, or an aryl group having 6 to 10 carbon atoms that 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 R 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 R 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 It is all hydrogen atoms. R in general formulas (6) to (12) 41 ~R 110 The carbon atoms to which the compound is bonded (the carbon atoms forming the ring skeleton) may each be independently substituted with a nitrogen atom. That is, the CR in general formulas (6) to (12) 41 ~CR 110 Each of these may be independently 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 (6) to (12). In one embodiment of the present invention, the number of nitrogen atoms substituted is 0. Furthermore, if two or more are substituted with nitrogen atoms, it is preferable that the number of nitrogen atoms substituted in one ring is 1. In general formulas (6) to (12), X 1 ~X 6 X represents an oxygen atom, a sulfur atom, or NR. In one aspect of the present invention, X 1 ~X 6 X is an oxygen atom. In one aspect of the present invention, X 1 ~X 6 is a sulfur atom. In one aspect of the present invention, X 1 ~X 6NR is NR. R represents a hydrogen atom or a substituent, and is preferably a substituent. Examples of substituents include those selected from the substituent group A above. For example, an unsubstituted phenyl group or a phenyl group substituted with one or more groups selected from the group consisting of alkyl groups and aryl groups can be preferably used. In general formulas (6) to (12), * represents the bonding position.

[0031] The following are some preferred compounds that can be used as the second organic compound. In the structural formulas of the following example compounds, t-Bu represents a tert-butyl group. [ka] JPEG0007829912000021.jpg239170JPEG0007829912000022.jpg250170JPEG0007829912000023.jpg221165JPEG00078299120 00024.jpg231163JPEG0007829912000025.jpg231170JPEG0007829912000026.jpg204170JPEG0007829912000027.jpg206150

[0032] In addition to the above, other known delayed fluorescence materials can be used in combination with the second organic compound as appropriate. Furthermore, even unknown delayed fluorescence materials can be used. As delayed fluorescence materials, paragraphs 0008-0048 and 0095-0133 of Publication No. WO2013 / 154064, paragraphs 0007-0047 and 0073-0085 of Publication No. WO2013 / 011954, paragraphs 0007-0033 and 0059-0066 of Publication No. WO2013 / 011955, and paragraphs 0008-007 of Publication No. WO2013 / 081088 Paragraphs 1 and 0118~0133, paragraphs 0009~0046 and 0093~0134 of Japanese Patent Publication No. 2013-256490, paragraphs 0008~0020 and 0038~0040 of Japanese Patent Publication No. 2013-116975, paragraphs 0007~0032 and 0079~0084 of WO2013 / 133359, paragraph 0008~ Paragraphs 0054 and 0101-0121, paragraphs 0007-0041 and 0060-0069 of JP 2014-9352, paragraphs 0008-0048 and 0067-0076 of JP 2014-9224, paragraphs 0013-0025 of JP 2017-119663, paragraphs 0013-0026 of JP 2017-119664, JP 2017- Examples include compounds included in the general formulas described in paragraphs 0012-0025 of Japanese Patent Publication No. 222623, paragraphs 0010-0050 of Japanese Patent Application Publication No. 2017-226838, paragraphs 0012-0043 of Japanese Patent Application Publication No. 2018-100411, and paragraphs 0016-0044 of Japanese Patent Application Publication No. WO2018 / 047853, particularly exemplary compounds that emit delayed fluorescence.Also, Japanese Patent Publication 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, Publications WO2015 / 072470, WO2015 / 108049, WO2015 / 080182, WO2015 / 072537, WO2015 / 080183, JP 2015-129240, WO2015 / 129714, WO2015 / 129715, WO2015 / 133 Light-emitting materials that emit delayed fluorescence, as described in Publication No. 501, WO2015 / 136880, WO2015 / 137244, WO2015 / 137202, WO2015 / 137136, WO2015 / 146541, and WO2015 / 159541, can also be used. The above publications mentioned in this paragraph are incorporated herein by reference as part of this specification.

[0033] It is preferable that the second organic compound does not contain metal atoms. For example, the second organic compound can be a compound composed of atoms selected from the group consisting of carbon atoms, hydrogen atoms, nitrogen atoms, oxygen atoms, and sulfur atoms.

[0034] (Third organic compound) The third organic compound used in the light-emitting layer of the organic electroluminescent element of the present invention is a fluorescent material that has a lower minimum excitation singlet energy than the first and second organic compounds, and a higher LUMO energy than the second organic compound. The organic light-emitting element of the present invention emits fluorescence originating from the third organic compound. The emission from the third organic compound usually includes delayed fluorescence. The largest component of the emission from the organic light-emitting element of the present invention is emission from the third organic compound. That is, the amount of emission from the third organic compound is the largest of the emission from the organic light-emitting element of the present invention. More than 70% of the emission from the organic electroluminescent element may be emission from the third organic compound, more than 90% may be emission from the third organic compound, or more than 99% may be emission from the third organic compound. The third organic compound transitions to the excited singlet state by receiving energy from the first organic compound in the excited singlet state, the second organic compound in the excited singlet state, and the second organic compound which has transitioned from the excited triplet state to the excited singlet state through reverse intersystem crossing. In a preferred embodiment of the present invention, the third organic compound receives energy from the second organic compound, which is in an excited singlet state, and from the second organic compound, which has transitioned from an excited triplet state to an excited singlet state through reverse intersystem crossing, and transitions to an excited singlet state. The excited singlet state of the resulting third organic compound emits fluorescence when it subsequently 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 and second organic compounds and emit light, and the emission may include fluorescence, delayed fluorescence, or phosphorescence. Preferably, the emission includes fluorescence or delayed fluorescence, and more preferably, the largest component of the emission from the third organic compound is fluorescence. In one aspect of the present invention, the organic electroluminescent element does not emit phosphorescence, or the amount of phosphorescent emission is 1% or less of the fluorescence.

[0035] Two or more third organic compounds may be used, provided they satisfy the conditions of the present invention. For example, by using two or more third organic compounds with different emission colors in combination, it becomes possible to emit a desired color. Alternatively, monochromatic emission may be produced from a single 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 luminescent materials having a maximum emission wavelength in the visible region (380-780 nm), luminescent materials having a maximum emission wavelength in the infrared region (780 nm-1 mm), or compounds having a maximum emission wavelength in the ultraviolet region (e.g., 280-380 nm). Preferably, fluorescent materials having a maximum emission wavelength in the visible region are used. For example, a luminescent material with a maximum emission wavelength within the 380-780 nm range of 380-570 nm may be selected and used, or a luminescent material with a maximum emission wavelength within the range of 570-650 nm may be selected and used, or a luminescent material with a maximum emission wavelength within the range of 650-700 nm may be selected and used, or a luminescent material with a maximum emission wavelength within the range of 700-780 nm may be selected and used. In one preferred embodiment of the present invention, the maximum emission wavelength of the third organic compound is longer than 570 nm. In a preferred embodiment of the present invention, each compound is selected and combined such that there is an overlap between the emission wavelength region of the second organic compound and the absorption wavelength region of the third organic compound. In particular, it is preferable that the short-wavelength edge of the emission spectrum of the second organic compound and the long-wavelength edge of the absorption spectrum of the third organic compound overlap. It is preferable that the third organic compound does not contain metal atoms other than boron atoms. For example, as the third organic compound, a compound consisting of atoms selected from the group consisting of carbon atoms, hydrogen atoms, nitrogen atoms, oxygen atoms, sulfur atoms, fluorine atoms, and boron atoms can be selected.

[0036] Examples of third organic compounds include compounds containing the BODIPY(4,4-difluoro-4-bora-3a,4a-diaza-s-indacene) structure and compounds containing condensed aromatic ring structures such as anthracene, pyrene, and perylene. In one preferred embodiment of the present invention, a compound represented by the following general formula (1) is used as the third organic compound. [ka]

[0037] In general formula (1), R 1 ~R 7 Each of these is independently a hydrogen atom or a substituent. 1 ~R 7 Preferably, at least one of these is a group represented by the following general formula (2). [ka] In general formula (2), R 11 ~R 15 Each of the symbols represents an independent hydrogen atom or substituent, and * represents a bond position. The group represented by general formula (2) is R in general formula (1). 1 ~R 7 Preferably, there are at least four of them, and for example, there can be four or five. In one preferred embodiment of the present invention, R 1 ~R 7 Five of these are groups represented by general formula (2). In one preferred embodiment of the present invention, at least R 1 , R 3 , R 5 , R 7 R is a group represented by general formula (2). In one preferred embodiment of the present invention, R 1 , R 3 , R 4 , R 5 , R 7 Only is the group represented by general formula (2). In one preferred embodiment of the present invention, R 1 , R 3 , R 4 , R 5 , R7 The group is represented by general formula (2), and R 2 and R 4 R is a hydrogen 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). In one aspect of the present invention, R 1 ~R 7 All of these are bases represented by general formula (2). In one preferred embodiment of the present invention, R 1 and R 7 They are identical. In one preferred embodiment of the present invention, R 3 and R 5 They are identical. In one preferred embodiment of the present invention, R 2 and R 6 They are identical. In one preferred embodiment of the present invention, R 1 and R 7 They are identical, R 3 and R 5 They are identical, and also, R 1 and R 3 They are different from each other. In one preferred embodiment of the present invention, R 1 , R 3 , R 5 , R 7 They are identical. In one preferred embodiment of the present invention, R 1 and R 4 and R 7 They are identical, R 3 Ya R 5 This is different. In one preferred embodiment of the present invention, R 3 and R 4 and R 5 They are identical, R 1 Ya R 7 This is different. In one preferred embodiment of the present invention, R 1 , R 3 , R 5 , R 7 All of these are R 4 It is different.

[0038] R in general formula (2) 11 ~R 15 Possible substituents include, for example, groups from substituent group A or groups from substituent group B. 11 ~R15 The substituents that can be adopted 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., 1 to 40 carbon atoms), substituted or unsubstituted alkoxy groups (e.g., 1 to 40 carbon atoms), substituted or unsubstituted aryl groups (e.g., 6 to 30 carbon atoms), substituted or unsubstituted aryloxy groups (e.g., 6 to 30 carbon atoms), and substituted or unsubstituted amino groups (e.g., 0 to 20 carbon atoms) (hereinafter these groups are referred to as "substituent group C groups"). Among substituent group C, it is preferable to select an unsubstituted alkyl group with 1 to 20 carbon atoms, an unsubstituted alkoxy group with 1 to 20 carbon atoms, an unsubstituted aryl group with 6 to 14 carbon atoms, an aryloxy group with 6 to 14 carbon atoms, or an unsubstituted diarylamino group with 5 to 20 constituent atoms of the ring skeleton (hereinafter these groups are referred to as "substituent group D groups"). The substituted amino group referred to here is preferably a disubstituted amino group, and the two substituents on the amino group are preferably independently substituted or unsubstituted aryl groups, substituted or unsubstituted heteroaryl groups, or substituted or unsubstituted alkyl groups, and it is particularly preferred that they be substituted or unsubstituted aryl groups (diarylamino groups). The substituents that the two aryl groups of the diarylamino group can take are groups from substituent group A, groups from substituent group B, or groups from substituent group C. The two aryl groups of the diarylamino group may be bonded to each other by a single bond or by a linking group, and the linking group referred to here is R 33 and R 34 You can refer to the explanation of the linking group in the above. As a specific example of a diarylamino group, for example, a substituted or unsubstituted carbazole-9-yl group can be used. As an example of a substituted or unsubstituted carbazole-9-yl group, for example, L of the above general formula (6) 11 We can list groups that are single-bonded. In one preferred embodiment of the present invention, R of general formula (2) 13 Only R is a substituent, 11 , R 12 , R 14 , R 15R is a hydrogen atom. In a preferred embodiment of the present invention, R of general formula (2) 11 Only R is a substituent, 12 , R 13 , R 14 , R 15 R is a hydrogen atom. In a preferred embodiment of the present invention, R of general formula (2) 11 and R 13 Only R is a substituent, 12 , R 14 , R 15 It is a hydrogen atom. R in general formula (1) 1 ~R 7 Among them is R in general formula (2). 11 ~R 15 It may also contain a group in which all atoms are hydrogen atoms (i.e., a phenyl group). For example, R 2 , R 4 , R 6 It may be a phenyl group.

[0039] In general formula (1), R 8 and R 9 Preferably, each of these is independently selected from the group consisting of a hydrogen 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, or a combination of two or more such groups. In a preferred embodiment of the present invention, R 8 and R 9 They are identical. In a preferred embodiment of the present invention, R 8 and R 9 This atom is a halogen atom, and is particularly preferably a fluorine atom.

[0040] R in general formula (1) 1 ~R 9 Preferably, the total number of substituted or unsubstituted alkoxy groups, substituted or unsubstituted aryloxy groups, and substituted or unsubstituted amino groups present is three or more. For example, a compound with three or four such groups may be used. More preferably, the R of general formula (1) 1 ~R 7Preferably, the total number of substituted or unsubstituted alkoxy groups, substituted or unsubstituted aryloxy groups, and substituted or unsubstituted amino groups present is three or more. For example, a compound with three or four such groups may be used. In this case, R 8 and R 9 The alkoxy group, aryloxy group, and amino group may not be present. More preferably, the R of general formula (1) 1 , R 3 , R 4 , R 5 , R 7 Preferably, the total number of substituted or unsubstituted alkoxy groups, substituted or unsubstituted aryloxy groups, and substituted or unsubstituted amino groups present is three or more. For example, a compound with three or four such groups may be used. In this case, R 2 , R 6 , R 8 , R 9 Alkoxy groups, aryloxy groups, and amino groups may not be present. In one preferred embodiment of the present invention, there are three or more substituted or unsubstituted alkoxy groups. In one preferred embodiment of the present invention, there are four or more substituted or unsubstituted alkoxy groups. In one preferred embodiment of the present invention, there is one or more substituted or unsubstituted alkoxy groups and two or more substituted or unsubstituted aryloxy groups. In one preferred embodiment of the present invention, there are two or more substituted or unsubstituted alkoxy groups and one or more substituted or unsubstituted amino groups. In one preferred embodiment of the present invention, R 1 , R 4 , R 7 Each of these contains a substituted or unsubstituted alkoxy group or a substituted or unsubstituted aryloxy. In a preferred embodiment of the present invention, R 1 , R 4 , R 7 Each of these groups may have a substituted or unsubstituted alkoxy group.

[0041] R in general formula (1) 1 ~R 9It is preferable that the total number of substituents present in the compound with Hammett σp values ​​less than -0.2 is three or more. Here, "Hammett σp value" is a value proposed by L.P. Hammett that quantifies the effect of substituents on the reaction rate or equilibrium of para-substituted benzene derivatives. Specifically, the following formula holds between substituents and the reaction rate constant or equilibrium constant in para-substituted benzene derivatives: log(k / k0) = ρσp or log(K / K0) = ρσp This is a constant (σp) specific to the substituent in the above formula. In the above formula, k is the rate constant of the unsubstituted benzene derivative, k0 is the rate constant of the substituted benzene derivative, K is the equilibrium constant of the unsubstituted benzene derivative, K0 is the equilibrium constant of the substituted benzene derivative, and ρ is the reaction constant determined by the type and conditions of the reaction. For an explanation of "Hammett's σp value" in this invention and the numerical values ​​of each substituent, refer to the description of σp value in Hansch, C. et. al., Chem. Rev., 91, 165-195 (1991). Groups with a negative Hammett's σp value tend to exhibit electron-donating properties, while groups with a positive Hammett's σp value tend to exhibit electron-withdrawing properties. Examples of substituents with a Hammett σp value of less than -0.2 include the methoxy group (-0.27), ethoxy group (-0.24), n-propoxy group (-0.25), isopropoxy group (-0.45), and n-butoxy group (-0.32). On the other hand, substituents such as the fluorine atom (0.06), methyl group (-0.17), ethyl group (-0.15), tert-butyl group (-0.20), n-hexyl group (-0.15), and cyclohexyl group (-0.15) do not have a Hammett σp value of less than -0.2. In one aspect of the present invention, R of general formula (1) 1 ~R 9 Compounds with three substituents having a Hammett σp value of less than -0.2 can be adopted, or compounds with four substituents can be adopted. More preferably, the R of general formula (1) 1 ~R 7It is preferable that there are three or more substituents present in the compound with a Hammett σp value of less than -0.2; for example, a compound with three substituents or a compound with four substituents can be adopted. In this case, R 8 and R 9 It is not necessary for the substituent to have a Hammett σp value of less than -0.2. More preferably, the R of general formula (1) 1 , R 3 , R 4 , R 5 , R 7 It is preferable that the number of substituents present in the compound with a Hammett σp value of less than -0.2 is three or more; for example, a compound with three substituents or a compound with four substituents can be adopted. In this case, R 2 , R 6 , R 8 , R 9 It is not necessary for there to be substituents with a Hammett σp value of less than -0.2. In one preferred embodiment of the present invention, R 1 , R 4 , R 7 Each of these substituents has a Hammett σp value of less than -0.2.

[0042] The following are preferred compounds that can be used as the third organic compound. In the structural formulas of the following example compounds, t-Bu represents a tert-butyl group. [ka] JPEG0007829912000031.jpg226169

[0043] In this specification, alkyl groups, alkenyl groups, aryl groups, heteroaryl groups, arylene groups, and heteroarylene groups refer to the following unless otherwise specified. The alkyl group may be linear, branched, or cyclic. Furthermore, two or more of the linear, cyclic, and branched portions may be mixed. The number of carbon atoms in the alkyl group can be, for example, 1 or more, 2 or more, or 4 or more. Also, the number of carbon atoms can be 30 or less, 20 or less, 10 or less, 6 or less, or 4 or less. Specific examples of alkyl groups include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, n-pentyl, isopentyl, n-hexyl, isohexyl, 2-ethylhexyl, n-heptyl, isoheptyl, n-octyl, isooctyl, n-nonyl, isononyl, n-decanyl, isodecanyl, cyclopentyl, cyclohexyl, and cycloheptyl groups. The alkyl group substituent may be further substituted with an aryl group. For the alkyl portion of "alkoxy group," "alkylthio group," "acyl group," and "alkoxycarbonyl group," you can refer to the explanation of "alkyl group" used here. The "alkenyl group" may be linear, branched, or cyclic. Furthermore, two or more of these linear, cyclic, and branched portions may be mixed. The number of carbon atoms in the alkenyl group can be, for example, 2 or more, 4 or more, or 30 or less, 20 or less, 10 or less, 6 or less, or 4 or less. Specific examples of alkenyl groups 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 other substituents. The "aryl group" and "heteroaryl group" may be monocyclic or fused rings formed by the fusion of two or more rings. 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 rings include benzene rings, pyridine rings, pyrimidine rings, triazine rings, naphthalene rings, anthracene rings, phenanthrene rings, triphenylene rings, quinoline rings, pyrazine rings, quinoxaline rings, and naphthyridine rings. Specific examples of aryl or heteroaryl groups include phenyl group, 1-naphthyl group, 2-naphthyl group, 1-anthracenyl group, 2-anthracenyl group, 9-anthracenyl group, 2-pyridyl group, 3-pyridyl group, and 4-pyridyl group. The "arylene group" and "heteroaryl group" may be defined by changing the valency from 1 to 2 in the descriptions of the aryl group and heteroaryl group. For the aryl portion of "aryloxy group," "arylthio group," and "aryloxycarbonyl group," refer to the explanation of "aryl group" as used here. For the heteroaryl portion of "heteroaryloxy group," "heteroarylthio group," and "heteroaryloxycarbonyl group," refer to the explanation of "heteroaryl group" as used here.

[0044] (Emitting layer) The light-emitting layer of the organic light-emitting device of the present invention comprises a light-emitting composition containing a first organic compound satisfying formulas (a) and (b), and a second organic compound and a third organic compound that are delayed fluorescence materials. In a preferred embodiment of the present invention, the light-emitting layer does not contain any compounds or metal elements that transfer charge or energy other than the first organic compound, the second organic compound, and the third organic compound. Alternatively, the light-emitting layer may consist only of the first organic compound, the second organic compound, and the third organic compound. Furthermore, the light-emitting layer may consist only of compounds composed of atoms selected from the group consisting of carbon atoms, hydrogen atoms, nitrogen atoms, boron atoms, oxygen atoms, sulfur atoms, and fluorine atoms. For example, the light-emitting layer may consist only of compounds composed of atoms selected from the group consisting of carbon atoms, hydrogen atoms, nitrogen atoms, boron atoms, oxygen atoms, and fluorine atoms. In a preferred embodiment of the present invention, the light-emitting layer contains carbon atoms, hydrogen atoms, nitrogen atoms, boron atoms, oxygen atoms, and fluorine atoms, and more preferably does not contain any other elements.

[0045] The light-emitting layer may be formed by a wet process or by a dry process using a light-emitting composition containing a first organic compound satisfying formulas (a) and (b), and a second organic compound and a third organic compound that are delayed fluorescence materials. In the wet process, a solution containing the luminescent composition is applied to a surface, and after the solvent is removed, a luminescent layer is formed. Examples of wet processes include, but are not limited to, spin coating, slit coating, inkjet (spray) printing, gravure printing, offset printing, and flexographic printing. In the wet process, an appropriate organic solvent capable of dissolving the luminescent composition is selected and used. In some embodiments, substituents (e.g., alkyl groups) that increase the solubility in organic solvents can be introduced into the compounds contained in the luminescent composition. As a dry process, vacuum deposition can be preferably employed. When using vacuum deposition, each compound constituting the light-emitting layer may be co-deposited from an individual deposition source, or all compounds may be co-deposited from a single deposition source. When using a single deposition source, a mixed powder of all compound powders may be used, a compressed molded body made by compressing the mixed powder may be used, or a mixture obtained by heating, melting, mixing, and then cooling each compound may be used. In one embodiment, by performing co-deposition under conditions where the deposition rates (weight loss rates) of multiple compounds contained in a single deposition source are the same or nearly the same, a light-emitting layer with a composition ratio corresponding to the composition ratio of multiple compounds contained in the deposition source can be formed. By mixing multiple compounds in the same composition ratio as the composition ratio of the formed light-emitting layer to form a deposition source, a light-emitting layer with a desired composition ratio can be easily formed. In one embodiment, the temperature at which each co-deposited compound has the same weight loss rate can be identified, and that temperature can be adopted as the temperature during co-deposition. When the light-emitting layer is formed by vapor deposition, the molecular weights of the first organic compound, the second organic compound, and the third organic compound are preferably 1500 or less, more preferably 1200 or less, even more preferably 1000 or less, and even more preferably 900 or less. The lower limit of the molecular weight may be, for example, 200, 400, or 600.

[0046] (Layer structure of organic light-emitting element) By forming a light-emitting layer made of a light-emitting composition containing a first organic compound satisfying formulas (a) and (b), a second organic compound which is a delayed fluorescence material, and a third organic compound, it is possible to provide excellent organic light-emitting elements such as organic photoluminescent elements (organic PL elements) and organic electroluminescent elements (organic EL elements). The thickness of the light-emitting layer can be, for example, 1-15 nm, 2-10 nm, or 3-7 nm. Organic photoluminescent elements have a structure in which at least a light-emitting layer is formed on a substrate. Organic electroluminescent elements have a structure in which at least an anode, a cathode, and an organic layer are formed between the anode and the cathode. The organic layer includes at least a light-emitting layer, and may consist only of a light-emitting layer, or it may have one or more organic layers in addition to the light-emitting layer. Examples of other such organic layers include hole transport layers, hole injection layers, electron barrier layers, electron injection layers, electron transport layers, and exciton barrier layers. The hole transport layer may be a hole injection transport layer with hole injection function, and the electron transport layer may be an electron injection transport layer with electron injection function. A specific structural example of an organic electroluminescent element is shown in Figure 1. In Figure 1, 1 represents the substrate, 2 represents the anode, 3 represents the hole injection layer, 4 represents the hole transport layer, 5 represents the light-emitting layer, 6 represents the electron transport layer, and 7 represents the cathode. When the organic light-emitting element of the present invention is a multi-wavelength emitting organic light-emitting element, the shortest wavelength emission may include delayed fluorescence. Alternatively, the shortest wavelength emission may not include delayed fluorescence. An organic light-emitting element comprising a light-emitting composition containing a first organic compound satisfying formulas (a) and (b), a second organic compound that is a delayed fluorescence material, and a third organic compound can emit light in the ultraviolet region, the blue, green, yellow, orange, and red regions of the visible spectrum (e.g., 420-500 nm, 500-600 nm, or 600-700 nm), or the near-infrared region when excited by thermal or electronic means. For example, an organic light-emitting element can emit light in the red or orange region (e.g., 620-780 nm). For example, an organic light-emitting element can emit light in the orange or yellow region (e.g., 570-620 nm). For example, an organic light-emitting element can emit light in the green region (e.g., 490-575 nm). For example, an organic light-emitting element can emit light in the blue region (e.g., 400-490 nm). For example, an organic light-emitting element can emit light in the ultraviolet spectral region (e.g., 280-400 nm). For example, an organic light-emitting element can emit light in the infrared spectral region (e.g., 780 nm to 2 μm). In a preferred embodiment of the present invention, the maximum emission wavelength of the element is longer than 570 nm (e.g., 570 to 780 nm).

[0047] The following describes each component of the organic electroluminescent element and each layer other than the light-emitting layer.

[0048] Base material: In some embodiments, the organic electroluminescent element of the present invention is held by a substrate, which is not particularly limited and may be any of the materials commonly used in organic electroluminescent elements, such as glass, transparent plastic, quartz, and silicon.

[0049] anode: In some embodiments, the anode of an organic electroluminescent apparatus is manufactured from a metal, alloy, conductive compound, or a combination thereof. In some embodiments, the metal, alloy, or conductive compound has a high work function (4 eV or more). In some embodiments, the metal is Au. In some embodiments, the conductive transparent material is selected from CuI, indium tin oxide (ITO), SnO2, and ZnO. In some embodiments, an amorphous material capable of forming a transparent conductive film, such as IDIXO (In2O3-ZnO), is used. In some embodiments, the anode is a thin film. In some embodiments, the thin film is manufactured by vapor deposition or sputtering. In some embodiments, the film is patterned by photolithography. In some embodiments, if the pattern does not need to be highly precise (e.g., about 100 μm or more), the pattern may be formed using a mask with a shape suitable for vapor deposition or sputtering onto the electrode material. In some embodiments, when a coating material such as an organic conductive compound can be applied, a wet film formation method such as printing or coating is used. In some embodiments, when synchrotron radiation passes through the anode, the anode has a transmittance of more than 10%, and the anode has a sheet resistance of several hundred ohms or less per unit area. In some embodiments, the thickness of the anode is 10 to 1,000 nm. In some embodiments, the thickness of the anode is 10 to 200 nm. In some embodiments, the thickness of the anode varies depending on the material used.

[0050] cathode: In some embodiments, the cathode is made of an electrode material such as a metal with a low work function (4 eV or less) (referred to as an electron-injection metal), an alloy, a conductive compound, or a combination thereof. In some embodiments, the electrode material is selected from sodium, sodium-potassium alloy, magnesium, lithium, magnesium-copper mixture, magnesium-silver mixture, magnesium-aluminum mixture, magnesium-indium mixture, aluminum-aluminum oxide (Al2O3) mixture, indium, lithium-aluminum mixture, and rare earth elements. In some embodiments, a mixture of the electron-injection metal and a second metal that is a stable metal having a higher work function than the electron-injection metal is used. In some embodiments, the mixture is selected from magnesium-silver mixture, magnesium-aluminum mixture, magnesium-indium mixture, aluminum-aluminum oxide (Al2O3) mixture, lithium-aluminum mixture, and aluminum. In some embodiments, the mixture improves electron-injection properties and resistance to oxidation. In some embodiments, the cathode is manufactured by forming the electrode material as a thin film by vapor deposition or sputtering. In some embodiments, the cathode has a sheet resistance of several hundred ohms or less per unit area. In some embodiments, the thickness of the cathode is 10 nm to 5 μm. In some embodiments, the thickness of the cathode is 50 to 200 nm. In some embodiments, either the anode or cathode of the organic electroluminescent element is transparent or translucent in order to transmit synchrotron radiation. In some embodiments, a transparent or translucent electroluminescent element enhances the light radiance. In some embodiments, a transparent or translucent cathode is formed by forming the cathode with respect to the conductive transparent material described above. In some embodiments, the element includes an anode and a cathode, both of which are transparent or translucent.

[0051] Injection layer: The injection layer is a layer between the electrode and the organic layer. In some embodiments, the injection layer reduces the driving voltage and enhances the light radiance. In some embodiments, the injection layer includes a hole injection layer and an electron injection layer. The injection layer can be located between the anode and the light-emitting layer or hole transport layer, and between the cathode and the light-emitting layer or electron transport layer. In some embodiments, an injection layer is present. In some embodiments, an injection layer is absent. The following are examples of preferred compounds that can be used as hole injection materials.

[0052] [ka]

[0053] Next, we will list some examples of preferred compounds that can be used as electron injection materials. [ka]

[0054] Barrier layer: A barrier layer is a layer that can prevent charges (electrons or holes) and / or excitons present in the light-emitting layer from diffusing to the outside of the light-emitting layer. In some embodiments, an electron barrier layer exists between the light-emitting layer and the hole transport layer, preventing electrons from passing through the light-emitting layer to the hole transport layer. In some embodiments, a hole barrier layer exists between the light-emitting layer and the electron transport layer, preventing holes from passing through the light-emitting layer to the electron transport layer. In some embodiments, a barrier layer prevents excitons from diffusing to the outside of the light-emitting layer. In some embodiments, the electron barrier layer and the hole barrier layer constitute an exciton barrier layer. As used herein, the terms “electron barrier layer” or “exciton barrier layer” include layers that have both the functions of an electron barrier layer and an exciton barrier layer.

[0055] Hole barrier layer: The hole barrier layer functions as an electron transport layer. In some embodiments, the hole barrier layer prevents holes from reaching the electron transport layer during electron transport. In some embodiments, the hole barrier layer increases the probability of electron-hole recombination in the light-emitting layer. The material used for the hole barrier layer may be the same material described above for the electron transport layer. The following are examples of preferred compounds that can be used in the hole barrier layer.

[0056] [ka]

[0057] Electron barrier layer: The electron barrier layer transports holes. In some embodiments, the electron barrier layer prevents electrons from reaching the hole transport layer during hole transport. In some embodiments, the electron barrier layer increases the probability of electron-hole recombination in the light-emitting layer. The material used for the electron barrier layer may be the same material described above for the hole transport layer. The following are specific examples of preferred compounds that can be used as electron barrier materials.

[0058] [ka]

[0059] Exciton barrier layer: The exciton barrier layer prevents excitons generated through the recombination of holes and electrons in the light-emitting layer from diffusing to the charge transport layer. In some embodiments, the exciton barrier layer enables effective confinement of excitons in the light-emitting layer. In some embodiments, the optical emission efficiency of the device is improved. In some embodiments, the exciton barrier layer is located on either the anode side or the cathode side and adjacent to the light-emitting layers on both sides. In some embodiments, when the exciton barrier layer is located on the anode side, it may be located between the hole transport layer and the light-emitting layer and adjacent to the light-emitting layer. In some embodiments, when the exciton barrier layer is located on the cathode side, it may be located between the light-emitting layer and the cathode and adjacent to the light-emitting layer. In some embodiments, a hole injection layer, electron barrier layer, or similar layer is located between the anode and the exciton barrier layer adjacent to the light-emitting layer on the anode side. In some embodiments, a hole injection layer, electron barrier layer, hole barrier layer, or similar layer is located between the cathode and the exciton barrier layer adjacent to the light-emitting layer on the cathode side. In some embodiments, the exciton barrier layer includes an excitation singlet energy and an excitation triplet energy, at least one of which is higher than the excitation singlet energy and excitation triplet energy of the luminescent material, respectively.

[0060] 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 the following properties: hole injection or transport properties and electron barrier 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, indrocarbazole derivatives, polyarylalkane derivatives, pyrazoline derivatives, pyrazolone derivatives, phenylenediamine derivatives, allylamine derivatives, aminosubstituted 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 given below.

[0061] [ka]

[0062] 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 have the function of transporting the 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 the electron transport layer that can be used in the present invention include, but are not limited to, nitro-substituted fluorene derivatives, diphenylquinone derivatives, thiopyrandioxide derivatives, carbodiimide, fluorenylidene methane derivatives, anthraquinodimethane, 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 the electron transport material are given below.

[0063] [Chemical formula]

[0064] Furthermore, examples of preferred compounds as materials that can be added to each organic layer are given. For example, it is conceivable to add them as a stabilizing material or the like.

[0065] [Chemical formula]

[0066] Although preferred materials that can be used in the organic electroluminescence device have been specifically exemplified, the materials that can be used in the present invention should not be construed as being limited by the following exemplified compounds. Also, even the compounds exemplified as materials having specific functions can be diverted as materials having other functions.

[0067] Device: In some embodiments, the light-emitting layer is incorporated into the device. For example, the device includes, but is not limited to, OLED bulbs, OLED lamps, displays for televisions, monitors for computers, mobile phones and tablets. In some embodiments, the electronic device includes an OLED having an anode, a cathode, and at least one organic layer including a light-emitting 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 promoting charge transfer or energy transfer within the device and / or as hole transport materials. Examples of such devices include, for example, 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 detection devices, organic photoreceptors, organic magnetic field-quench (O-FQD) devices, light-emitting fuel cells (LECs), or organic laser diodes (O-lasers).

[0068] Valve or lamp: In some embodiments, the electronic device includes an OLED having an anode, a cathode, and at least one organic layer including a light-emitting 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 combination of three colors (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 combination of two colors, four colors, or more colors. In some embodiments, the device is a circuit board having a first surface with an attachment surface and a second surface opposite thereto and defining at least one opening, The mounting surface comprises at least one OLED having a light-emitting configuration, wherein the at least one OLED includes an anode, a cathode, and at least one organic layer comprising a light-emitting layer between the anode and the cathode, A housing for a circuit board, An OLED light comprising at least one connector located at the end of the housing, wherein the housing and the connector define a package suitable for mounting to a lighting fixture. In some embodiments, the OLED light has multiple OLEDs mounted on a circuit board such that light is emitted in multiple directions. In some embodiments, some of the light emitted in the 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.

[0069] 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 compound according to the present invention is deposited on a substrate using a process such as vacuum evaporation, deposition, vapor deposition, or chemical vapor deposition (CVD), but is not limited. In some embodiments, the substrate is a photoplate structure useful in two-sided etching, providing pixels with a unique aspect ratio. The screen (also called a mask) is used in the manufacturing process of an OLED display. The design of the corresponding artwork pattern allows for the arrangement of very steep, narrow tie bars between pixels in the vertical direction, as well as large, wide oblique apertures in the horizontal direction. This enables the fine pattern configuration of pixels required for high-resolution displays, while optimizing chemical vapor deposition on a TFT backplane. Internal patterning of pixels allows for the creation of three-dimensional pixel apertures with various aspect ratios in the horizontal and vertical directions. Furthermore, the use of imaged "stripes" or halftone circles within a pixel area protects etching in specific areas until these particular patterns are undercut and removed from the substrate. At that time, all pixel areas are processed at a similar etching rate, but the depth varies depending on the halftone pattern. By changing the size and spacing of the halftone patterns, etching with varying degrees of protection within the pixel becomes possible, enabling localized deep etching necessary to form steep vertical bevels. A preferred material for deposition masks is Invar. Invar is a metal alloy that is cold-rolled into long, thin sheets at steel mills. Invar cannot be electrodeposited onto a spin mandrel as a nickel mask. A suitable and low-cost method for forming openings within a 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.

[0070] 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, coating the TFT with a planarization film, sequentially forming pixel electrodes, an emissive layer, a counter electrode, and an encapsulation layer over time, and then cutting it from 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, coating the TFT with a planarization film, sequentially forming pixel electrodes, an emissive layer, a counter electrode, and an encapsulation layer over time, and then cutting it from the mother panel.

[0071] In another aspect of the present invention, a method for manufacturing an organic light-emitting diode (OLED) display is provided, the method being A process of forming a barrier layer on the base substrate of the mother panel, The process of forming multiple display units on the barrier layer in cell panel units, The process of forming an encapsulation layer on each of the display units of the cell panel, The process includes the step of applying an organic film to the interface portion between the cell panels. In some embodiments, the barrier layer is an inorganic film formed of, for example, SiNx, and the edges of the barrier layer are covered with an organic film formed of polyimide or acrylic. In some embodiments, the organic film assists in the soft cutting of the mother panel into cell panel units. In some embodiments, the thin-film transistor (TFT) layer includes a light-emitting layer, a gate electrode, and source / drain electrodes. Each of a 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, wherein the organic film coated on the interface portion is formed of the same material as the planarization film and is formed simultaneously with the formation of the planarization film. In some embodiments, the light-emitting unit is connected to the TFT layer by a passivation layer, a planarization film between them, 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 the display unit or the encapsulation layer.

[0072] Each of the organic film and the planarization film may contain either polyimide or 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 the steps of attaching a carrier substrate made of glass material to another surface of the base substrate before forming a barrier layer on one surface of the polyimide 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 placed on the TFT layer for coating 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 made of polyimide or acrylic, as is the organic film formed at the edges of the barrier layer. In some embodiments, the planarization film and the organic film are formed simultaneously during the manufacture of the OLED display. In some embodiments, the organic film may be formed at the edges of the barrier layer, so that a portion of the organic film is in direct contact with the base substrate, and the remaining portion of the organic film is in contact with the barrier layer while surrounding the edges of the barrier layer.

[0073] In some embodiments, the light-emitting layer includes a pixel electrode, a counter electrode, and an organic light-emitting layer disposed between the pixel electrode and the counter electrode. In some embodiments, the pixel electrode is connected to the source / drain electrodes of the TFT layer. In some embodiments, when a voltage is applied to the pixel electrode through the TFT layer, an appropriate voltage is formed between the pixel electrode and the counter electrode, causing 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 will be referred to as a display unit. In some embodiments, the encapsulation layer covering the display unit and preventing the penetration of external moisture may be formed as a thin-film encapsulation structure in which organic films and inorganic films are alternately laminated. In some embodiments, the encapsulation layer has a thin-film encapsulation structure in which a plurality of thin films are laminated. In some embodiments, the organic film applied to the interface portion is spaced apart from each of the plurality of display units. In some embodiments, the organic film is formed such that a portion of the organic film is in direct contact with the base substrate, while the remaining portion of the organic film surrounds the edges of the barrier layer while also being in contact with the barrier layer.

[0074] In one embodiment, the OLED display is flexible and uses a flexible base substrate made of polyimide. In some embodiments, the base substrate is formed on a carrier substrate made of glass material, and then the carrier substrate is separated. In some embodiments, the 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 interface between the barrier layers of the cell panels. Each cell panel can be cut along the grooves.

[0075] In some embodiments, the manufacturing method further includes a step of cutting along the interface portion, where a groove is formed in the barrier layer, and at least a portion of the organic film is formed in the groove, and the groove does not penetrate the base substrate. In some embodiments, a TFT layer is formed for each cell panel, and a passivation layer, which is an inorganic film, and a planarization film, which is an organic film, are placed on the TFT layer and cover the TFT layer. At the same time that a planarization film made of, for example, polyimide or acrylic is formed, the groove in the interface portion is covered with an organic film made of, for example, polyimide or acrylic. This prevents cracking by allowing the organic film to absorb the impact generated when each cell panel is cut along the groove at the interface portion. That is, if all barrier layers are completely exposed without an organic film, when each cell panel is cut along the groove at the interface portion, the impact generated is transmitted to the barrier layer, thereby increasing the risk of cracking. However, in one embodiment, the groove in the interface portion between barrier layers may be covered with an organic film to absorb the impact that would otherwise be transmitted to the barrier layer, so that each cell panel is cut softly and cracking in the barrier layer is prevented. In one embodiment, the organic film and the planarizing film covering the grooves of the interface portion are arranged with a gap between them. For example, if the organic film and the planarizing film are connected to each other as a single layer, there is a risk that external moisture may penetrate the display unit through the remaining parts of the planarizing film and organic film. Therefore, the organic film and the planarizing film are arranged with a gap between them so that the organic film is spaced away from the display unit.

[0076] In some embodiments, the display unit is formed by the formation of a light-emitting unit, and an encapsulation layer is placed on the display unit to cover it. This separates the carrier substrate supporting the base substrate from the base substrate after the mother panel is completely manufactured. In some embodiments, when a laser beam is emitted onto the carrier substrate, the carrier substrate is separated from the base substrate due to the difference in thermal expansion coefficients between the carrier substrate and the base substrate. In some embodiments, the mother panel is cut into cell panel units. In some embodiments, the mother panel is cut along the interface between cell panels using a cutter. In some embodiments, the grooves of the interface along which the mother panel is cut are covered with an organic film so that the organic film absorbs the impact during cutting. In some embodiments, cracking can be prevented in the barrier layer during cutting. In some embodiments, the method reduces the defect rate of the product and stabilizes its 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 coated on the edges of the barrier layer.

[0077] (Method for designing luminescent compositions) This invention also provides a method for designing a light-emitting composition that can be used in the light-emitting layer of an organic light-emitting device. By using the design method of the present invention, it is possible to easily design a light-emitting composition for use in the light-emitting layer of a light-emitting device that has a long light-emitting lifetime and excellent stability. The present invention provides a method for designing a light-emitting composition, comprising the following steps 1 to 3. [Step 1] Evaluate at least one of the luminescence efficiency and driving voltage of a composition comprising a first organic compound, a second organic compound which is a delayed fluorescence material, and a third organic compound that satisfies formula (a) and formula (b). Evaluate at least one of the first organic compound, the second organic compound which is a delayed fluorescence material, and the third organic compound at least once within the range satisfying formula (a) and formula (b) for at least one of the luminous efficiency and the driving voltage. [Step 3] Select the combination of compounds with the best results for the evaluated luminous efficiency and driving voltage.

[0078] The evaluation of the luminous efficiency and the driving voltage may be performed by actually causing the light-emitting composition to emit light or by calculation. Also, the evaluation may be performed by actually causing the light-emitting composition to emit light and using a calculation method. The evaluation is preferably performed from a comprehensive perspective using high practicality as an index. In the method for designing the light-emitting composition of the present invention, it is necessary to select and replace the first organic compound, the second organic compound, and the third organic compound within the range satisfying formula (a) and formula (b). Also, the second organic compound needs to be selected and replaced from delayed fluorescence materials. The substitution of the compound in Step 2 is preferably replaced with a compound that is likely to obtain a better evaluation. Step 2 may be performed, for example, 10 or more times, 100 or more times, 1000 or more times, 10000 or more times. In the present invention, only the luminous efficiency may be evaluated, or only the driving voltage may be evaluated, but it is preferable to evaluate both. The light-emitting composition designed by the design method of the present invention can be used as a light-emitting layer of an organic light-emitting device (particularly the organic electroluminescence device of the present invention). The method for designing the light-emitting composition of the present invention can be saved and used as a program. The program can be stored in a recording medium and can also be transmitted and received by electronic means.

Example

[0079] The features of the present invention will be further described in detail below with reference to test examples and embodiments. The materials, processing content, 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 interpreted as being limited by the specific examples shown below. The luminescence characteristics were evaluated using a source meter (Keithley Corporation: 2400 series), a semiconductor parameter analyzer (Agilent Technologies: E5273A), an optical power meter measuring device (Newport Corporation: 1930C), an optical spectrometer (Ocean Optics: USB2000), a spectroradiometer (Topcon Corporation: SR-3), and a streak camera (Hamamatsu Photonics K.K.: C4334).

[0080] (Example of test) Measurement of electron mobility On a glass substrate on which an anode made of indium tin oxide (ITO) with a thickness of 50 nm is formed, the following thin films are deposited by vacuum deposition at a vacuum of 5.0 × 10⁻⁶. -5 A device for measuring electron mobility was fabricated by laminating with Pa. First, aluminum (Al) was deposited onto ITO to a thickness of 50 nm. Next, the first, second, and third organic compounds were co-deposited from different deposition sources to form a 100 nm thick layer. At this time, the co-deposit was carried out so that the first organic compound accounted for 64 mass%, the second organic compound for 35 mass%, and the third organic compound for 1 mass. Then, a layer of Liq was formed to a thickness of 2 nm, and further aluminum (Al) was deposited to a thickness of 100 nm to form a cathode, creating a device for measuring electron mobility. Devices 1-3 were fabricated using the compounds listed in the table below as the first, second, and third organic compounds. Note that all compounds used in each device satisfy the relationship of the lowest excited singlet energy in equation (a). The table below shows the LUMO energy E of the second organic compound. LUMO (2) and the energy E of the LUMO of the third organic compound LUMO (3) was also shown for each device. Device 1 and Device 2 do not satisfy the LUMO energy relationship in equation (b), while Device 3 does satisfy the LUMO energy relationship in equation (b). [Table 1]

[0081] Comparative devices 1-3 were also fabricated in which the co-deposited layer was formed using only the first and second organic compounds, without the third organic compound, for each device 1-3. The electron mobility was measured for each of the fabricated devices 1-3 and comparison devices 1-3. The ratio R of the electron mobility of device 1 was calculated by dividing the electron mobility of device 1 by the electron mobility of comparison device 1. EM The ratio of electron mobilities R was calculated for devices 2 and 3, respectively. EM We calculated the following. Furthermore, we determined the energy difference ΔE between the LUMOs of the second and third organic compounds used in devices 1-3. LUMO to, E LUMO (3)-E LUMO (2) was calculated to obtain the ratio of electron mobility R of each device. EM With ΔE as the vertical axis, LUMO Figure 2 shows the results of plotting with the horizontal axis. The results in Figure 2 show that when the LUMO energy of the third organic compound is smaller than the LUMO energy of the second organic compound (i.e., ΔLUMO is negative), the electron mobility decreases and electron transfer slows down. However, when the LUMO energy of the third organic compound is larger than the LUMO energy of the second organic compound (i.e., ΔLUMO is positive), the decrease in electron mobility is suppressed and electron transfer does not slow down easily. In other words, if the relationship in equation (b) is satisfied, it indicates that electron trapping by the third organic compound is suppressed.

[0082] (Examples 1-2, Comparative Example 1) Fabrication and evaluation of organic electroluminescent devices On a glass substrate on which an anode made of indium tin oxide (ITO) with a thickness of 50 nm is formed, the following thin films are deposited by vacuum deposition at a vacuum of 5.0 × 10⁻⁶. -5 Organic electroluminescent elements were fabricated by stacking layers of Pa. First, HAT-CN was formed to a thickness of 10 nm on ITO, and then NPD was formed on top of it to a thickness of 30 nm. Next, Tris-PCz was formed to a thickness of 10 nm, and then H1 was formed on top of it to a thickness of 5 nm. Then, the first, second, and third organic compounds were co-deposited from different deposition sources to form a 30 nm thick layer which served as the light-emitting layer. At this time, the co-deposit was carried out so that the first organic compound was 64 mass%, the second organic compound was 35 mass%, and the third organic compound was 1 mass%. Next, SF3-TRZ was formed to a thickness of 10 nm, and then Liq and SF3-TRZ were co-deposited from different deposition sources to form a 30 nm thick layer. The content of Liq and SF3-TRZ in this layer was 30 mass% and 70 mass%, respectively. Furthermore, Liq was formed to a thickness of 2 nm, and then aluminum (Al) was deposited to a thickness of 100 nm to form a cathode, thus creating an organic electroluminescent device. Organic electroluminescent devices for Examples 1-2 and Comparative Example 1 were fabricated using the compounds listed in the table below as the first, second, and third organic compounds. All compounds used in each device satisfy the relationship of the lowest excited singlet energy in equation (a). The table below shows the LUMO energy E of the second organic compound. LUMO (2) and the energy E of the LUMO of the third organic compound LUMO (3) is also shown for each. The organic electroluminescent element of Comparative Example 1 does not satisfy the LUMO energy relationship of formula (b), while the organic electroluminescent elements of Examples 1 and 2 satisfy the LUMO energy relationship of formula (b). For each of the fabricated organic electroluminescent elements, the current was 15.4 mA / cm². 2 The external quantum yield (EQE) and drive voltage (V) were measured. The results are shown in the table below. The drive voltage is shown as a relative value ΔV with respect to the drive voltage of Comparative Example 1. A smaller value of ΔV indicates that it was driven at a lower voltage. From the results shown in the table below, it was confirmed that the organic electroluminescent element of the present invention that satisfies equations (a) and (b) exhibits high luminescence efficiency at a low drive voltage. [Table 2]

[0083] [ka] [Explanation of symbols]

[0084] 1 Base material 2 Anode 3. Hole injection layer 4. Hole transport layer 5. Emitting layer 6 Electron transport layer 7 Cathode

Claims

1. An organic electroluminescent element having an anode, a cathode, and at least one organic layer including a light-emitting layer between the anode and the cathode, The light-emitting layer comprises a first organic compound, a second organic compound, and a third organic compound. The second organic compound is a delayed fluorescence material represented by the following general formula (3), The largest component of the light emitted from the element is the light emitted from the third organic compound. An organic electroluminescent element in which the first organic compound, the second organic compound, and the third organic compound satisfy the following formulas (a) and (c). [Math 1] [Here, E Ｓ１ (1) The lowest excited singlet energy of the first organic compound E Ｓ１ (2) The lowest singlet excitation energy of the second organic compound E Ｓ１ (3) The lowest excited singlet energy of the third organic compound E LUMO (2) The LUMO energy of the second organic compound E LUMO (3) represents the LUMO energy of the third organic compound. 【number】 [Here, one of R 21 to R 23 represents a cyano group or a group represented by the following general formula (4), the remaining two of R 21 to R 23 and at least one of R 24 and R 25 each independently represent a group represented by the following general formula (5), and the remaining R 21 to R 25 each independently represent a hydrogen atom or a substituent, but the substituent referred to here is not a cyano group, a group represented by the following general formula (4), or a group represented by the following general formula (5). However, at least one of the following (A) and (B) is satisfied. (A) The remaining two R21 to R23 and three of R24 and R25 each independently represent a group represented by the following general formula (5). (B) One of R21 to R23 represents a group represented by the following general formula (4), and the remaining two of R21 to R23, along with at least two of R24 and R25, each independently represent a group represented by the following general formula (5). 【number】 [Here, L1 represents a single bond or a divalent linking group, R31 and R32 each independently represent a hydrogen atom or a substituent, and * represents a bond position.] 【number】 [Here, L2 represents a single bond or a divalent linking group, R33 and R34 each independently represent a hydrogen atom or substituent, and * represents a bond position.]

2. The organic electroluminescent element according to claim 1, wherein the maximum emission wavelength of the third organic compound is longer than 570 nm.

3. Energy E of the LUMO of the third organic compound LUMO (3) The organic electroluminescent element according to claim 1 or 2, wherein (3) is greater than -3.5 eV.

4. The organic electroluminescent element according to any one of claims 1 to 3, wherein the third organic compound is a compound represented by the following general formula (1). 【Chemistry 4】 [Here, R １ to R ７ are each independently a hydrogen atom or a substituent. R ８ and R ９ are each independently a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted aryloxy group, or a cyano group.]

5. R １ ~R ７ The organic electroluminescent element according to claim 4, wherein at least one of the groups is represented by the following general formula (2). 【Transformation 5】 [Here, R １１ ~R １５ Each of the symbols represents an independent hydrogen atom or substituent, and * represents a bond position.

6. R in the general formula (1) １ ~R ７ The organic electroluminescent element according to claim 5, wherein at least four of them are groups represented by the general formula (2) independently.

7. R in the general formula (1) １ , R ３ , R ５ , R ７ The organic electroluminescent element according to claim 6, wherein each of the groups is independently represented by the general formula (2).

8. R in the general formula (1) １ ~R ９ The organic electroluminescent element according to any one of claims 4 to 7, wherein the total number of substituted or unsubstituted alkoxy groups, substituted or unsubstituted aryloxy groups, and substituted or unsubstituted amino groups present is three or more.

9. R in the general formula (1) １ ~R ９ An organic electroluminescent element according to any one of claims 4 to 7, wherein the number of substituents present in the element whose Hammett σp value is less than -0.2 is three or more.

10. In the above general formula (3), R ２１ ~R ２３ The organic electroluminescent element according to claim 9, wherein one of the groups is represented by the general formula (4).

11. In the above general formula (3), R ２１ and R ２２ The organic electroluminescent element according to claim 9 or 10, wherein one of the groups is a cyano group or a group represented by the general formula (4).

12. The organic electroluminescent element according to any one of claims 9 to 11, wherein the general formula (5) is a group represented by the following general formula (6). 【Transformation 6】 [Here, L １１ represents a single bond or a divalent linking group, R ４１ ~R ４８ Each of the symbols represents an independent hydrogen atom or substituent, and * represents a bond position. ４１ ~R ４８ Each carbon atom to which it is bonded may be independently substituted with a nitrogen atom.

13. The organic electroluminescent element according to any one of claims 9 to 11, wherein the general formula (5) is a group represented by any one of the following general formulas (7) to (12). 【Transformation 7】 [Here, L ２１ ~L ２６ represents a single bond or a divalent linking group, R ５１ ~R １１０ Each of these independently represents a hydrogen atom or a substituent, X １ ~X ６ * represents an oxygen atom, a sulfur atom, or N-R, where R represents a hydrogen atom or a substituent, and * represents the bond position. ５１ ~R １１０ Each carbon atom to which it is bonded may be independently substituted with a nitrogen atom.

14. An organic electroluminescent element according to any one of claims 1 to 13, wherein the light-emitting layer contains carbon atoms, hydrogen atoms, nitrogen atoms, boron atoms, oxygen atoms, and fluorine atoms, but does not contain any other elements.

15. [Step 1] Evaluate at least one of the luminescence efficiency and driving voltage of a composition comprising a first organic compound, a second organic compound represented by the following general formula (3) which is a delayed fluorescence material, and a third organic compound, satisfying the following formulas (a) and (c). [Step 2] At least once, evaluate the luminescence efficiency and driving voltage of compositions obtained by substituting at least one of the first organic compound, the second organic compound represented by the following general formula (3) which is a delayed fluorescence material, and the third organic compound within the range that satisfies the following formulas (a) and (c). [Step 3] Select the best combination of compounds based on the evaluated luminous efficiency and driving voltage. A method for designing a light-emitting composition, including each step. [Math 3] [Here, E Ｓ１ (1) The lowest excited singlet energy of the first organic compound E Ｓ１ (2) The lowest singlet excitation energy of the second organic compound E Ｓ１ (3) The lowest excited singlet energy of the third organic compound E LUMO (2) The LUMO energy of the second organic compound E LUMO (3) represents the LUMO energy of the third organic compound. 【number】 [Here, one of R 21 to R 23 represents a cyano group or a group represented by the following general formula (4), the remaining two of R 21 to R 23 and at least one of R 24 and R 25 each independently represent a group represented by the following general formula (5), and the remaining R 21 to R 25 each independently represent a hydrogen atom or a substituent, but the substituent referred to here is not a cyano group, a group represented by the following general formula (4), or a group represented by the following general formula (5). However, at least one of the following (A) and (B) is satisfied. (A) The remaining two R21 to R23 and three of R24 and R25 each independently represent a group represented by the following general formula (5). (B) One of R21 to R23 represents a group represented by the following general formula (4), and the remaining two of R21 to R23, along with at least two of R24 and R25, each independently represent a group represented by the following general formula (5). 【number】 [Here, L1 represents a single bond or a divalent linking group, R31 and R32 each independently represent a hydrogen atom or a substituent, and * represents a bond position.] 【number】 [Here, L2 represents a single bond or a divalent linking group, R33 and R34 each independently represent a hydrogen atom or substituent, and * represents a bond position.]

16. A program that carries out the method according to claim 15.

Images