Organic electroluminescent element, display device and lighting device

Abstract

An organic electroluminescent element has a light-emitting layer, in which the light-emitting layer contains, as a first component, a main compound having a boron atom and an oxygen atom in the molecule; as a second component, a thermally activated delayed phosphor having a difference ΔEST between an excited singlet energy level and an excited triplet energy level of less than 0.20 eV; and as a third component, a phosphor. The organic electroluminescent element has high luminous efficiency.

Description

Technical Field

[0001] The present invention relates to an organic electroluminescent element including three components of a host compound, a thermally activated delayed phosphor and a phosphor in a light-emitting layer, and a display device and a lighting device including the organic electroluminescent element. Background Art

[0002] In the past, display devices using light-emitting elements that perform electroluminescence have been studied in various ways because they can achieve power saving and thinness. In addition, organic electroluminescent elements (organic EL elements) formed of organic materials have been actively studied because they are easy to be lightweight and large-scale. In particular, the development of organic materials having luminous properties such as blue, which is one of the three primary colors of light, and the development of organic materials having charge transport capabilities such as holes and electrons, have been actively studied so far, regardless of whether they are polymer compounds or low molecular weight compounds.

[0003] An organic EL element has a structure that includes a pair of electrodes including an anode and a cathode, and one or more layers disposed between the pair of electrodes and including an organic compound. The layer including the organic compound includes a light-emitting layer, a charge transport / injection layer for transporting or injecting charges such as holes and electrons, and various organic materials suitable for these layers have been developed.

[0004] As the luminescence mechanism of organic EL elements, there are mainly two types: fluorescence luminescence using luminescence from an excited singlet state and phosphorescence luminescence using luminescence from an excited triplet state. The exciton utilization efficiency of general fluorescent luminescent materials is low, about 25%, and even if triplet-triplet fusion (TTF: Triplet-Triplet Fusion; or triplet-triplet annihilation, TTA: Triplet-Triplet Annihilation) is used, the exciton utilization efficiency is 62.5%. On the other hand, phosphorescent materials can also achieve an exciton utilization efficiency of 100%, but it is difficult to achieve deep blue luminescence, and the width of the luminescent spectrum is wide, so there is a problem of low color purity.

[0005] Therefore, Professor Chiba Ya Ando of Kyushu University proposed the thermally activated delayed fluorescence (TADF: Thermally Assisting Delayed Fluorescence) mechanism (refer to non-patent document 1). TADF compounds are compounds that can absorb thermal energy and undergo reverse intersystem crossing from the excited triplet state to the excited singlet state, and can undergo radiative deactivation from the excited singlet state to emit fluorescence (delayed fluorescence). By using such TADF compounds, the energy of triplet excitons can also be effectively utilized for fluorescent light emission, so that the efficiency of light-emitting exciton utilization reaches 100%. Due to its structure, TADF compounds provide a wide emission spectrum with low color purity, but the speed of reverse intersystem crossing is extremely fast.

[0006] In view of this advantage, an organic light-emitting element (TAF element: TADF Assisting Fluorescence element) using a TADF compound as an assisting dopant (Assisting Dopant: AD) has been proposed (see Patent Document 1). The TAF element uses three components, namely a host compound, a TADF compound (assisting dopant) and a phosphor, and utilizes reverse intersystem crossing in the TADF compound to convert the excited triplet energy into excited singlet energy and move it to the phosphor. As a result, the excited triplet energy is effectively used for the light emission of the phosphor to obtain high light emission efficiency, and light emission with high color purity is achieved through the phosphor.

[0007] Prior art literature

[0008] Patent Literature

[0009] Patent Document 1: Japanese Patent No. 5669163

[0010] Non-patent literature

[0011] Non-patent literature 1: Highly efficient organic light-emitting diodes from delayed fluorescence, Nature 492, 234-238 Summary of the invention

[0012] Problem that the invention aims to solve

[0013] As described above, an organic light-emitting element (TAF element) using a TADF compound as an auxiliary dopant has been proposed. However, when the inventors studied the performance of the three components used in the conventional TAF element and the luminous efficiency of the element, they found that the charge mobility in the light-emitting layer and the sealing effect of sealing triplet excitons in the TADF compound molecule were insufficient, and the luminous efficiency still had room for further improvement.

[0014] Therefore, in order to solve the problems of the prior art, the present inventors have conducted studies with an effort to provide an organic light-emitting element capable of obtaining higher light-emitting efficiency by using a TADF compound.

[0015] Solutions for solving problems

[0016] The inventors of the present invention have conducted in-depth research to solve the above-mentioned problems, and have obtained the following insights: by using a compound having a boron atom and an oxygen atom in the molecule as the host compound of a three-component system consisting of a host compound, a thermally activated delayed phosphor, and a phosphor, the luminous efficiency is significantly improved compared to a system using a conventional host compound such as mCBP (see Examples described below). The present invention is proposed based on this insight, and specifically has the following structure.

[0017] [1] An organic electroluminescent element having a light-emitting layer, wherein the light-emitting layer comprises, as a first component, a host compound having a boron atom and an oxygen atom in the molecule; as a second component, a thermally activated delayed phosphor having a difference ΔEST between an excited singlet energy level and an excited triplet energy level of less than 0.20 eV; and as a third component, a phosphor.

[0018] [2] The organic electroluminescent element according to [1], wherein the light-emitting layer contains, as the first component, at least one compound represented by any of the following formulae (i), (ii) and (iii).

[0019]

[0020] (In the above formula (i),

[0021] Ring A, Ring B and Ring C are each independently an aromatic ring or a heteroaromatic ring, at least one hydrogen in these rings is optionally substituted, and at least one hydrogen in the compound or structure represented by formula (i) is optionally substituted by cyano, halogen or deuterium.

[0022]

[0023] (In the above formula (ii), Ring A, Ring B and Ring C are each independently an aromatic ring or a heteroaromatic ring, at least one hydrogen atom in these rings may be substituted, and Y 1 For B, X 1 , X 2 and X 3 Each independently is >O, >NR, >CR2 or >S, X 1 ~X 3At least two of them are >O, the R of the aforementioned NR and the R of >CR2 are optionally substituted aryl, optionally substituted heteroaryl or alkyl, and the R of the aforementioned >NR is optionally bonded to at least one of the aforementioned A ring, B ring and C ring via a linking group or a single bond; and at least one hydrogen in the compound or structure represented by formula (ii) is optionally substituted by cyano, halogen or deuterium.)

[0024]

[0025] (In the above formula (iii), Ring A, Ring B, Ring C and Ring D are each independently an aromatic ring or a heteroaromatic ring, at least one hydrogen atom in these rings is optionally substituted, and R 1 and R 2 Each is independently hydrogen, an alkyl group having 1 to 6 carbon atoms, an aryl group having 6 to 12 carbon atoms, a heteroaryl group having 2 to 15 carbon atoms, a diarylamino group (wherein the aryl group is an aryl group having 6 to 12 carbon atoms), a diheteroarylamino group (wherein the heteroaryl group is a heteroaryl group having 2 to 15 carbon atoms), or an arylheteroarylamino group (wherein the aryl group is an aryl group having 6 to 12 carbon atoms, and the heteroaryl group is a heteroaryl group having 2 to 15 carbon atoms), and at least one hydrogen in the compound represented by formula (iii) is optionally substituted by cyano, halogen or deuterium.

[0026] [3] The organic electroluminescent element according to any one of [1] and [2], wherein the light-emitting layer contains, as the first component, at least one compound represented by any of the following formulae (1), (2) and (3).

[0027]

[0028] (In the above formula (1), R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , R 8 , R 9 , R 10 and R 11 Each is independently hydrogen, aryl, heteroaryl, diarylamino, diheteroarylamino, arylheteroarylamino, alkyl, cycloalkyl, alkoxy or aryloxy, which are optionally further substituted by at least one selected from aryl, heteroaryl and alkyl, and at least one hydrogen in the compound and structure represented by formula (1) is optionally substituted by cyano, halogen or deuterium.

[0029]

[0030] (In the above formula (2), R 1 , R2 , R 3 , R 4 , R 5 , R 6 , R 9 , R 10 and R 11 are each independently hydrogen, aryl, heteroaryl, diarylamino, diheteroarylamino, arylheteroarylamino, alkyl, cycloalkyl, alkoxy or aryloxy, which are optionally further substituted with at least one selected from aryl, heteroaryl and alkyl, 1 , X 2 and X 3 Each independently is >O, >NR, >S or >CR2, X 1 , X 2 and X 3 At least two of the above-mentioned >NR and >CR2 are aryl, heteroaryl or alkyl, which are optionally further substituted by at least one selected from aryl, heteroaryl and alkyl, wherein X 1 , X 2 and X 3 are not >CR2 at the same time, and at least one hydrogen in the compound and structure represented by formula (2) is optionally replaced by cyano, halogen or deuterium.

[0031]

[0032] (In the above formula (3), R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , R 8 , R 9 , R 10 , R 11 , R 12 , R 13 and R 14 are each independently hydrogen, aryl, heteroaryl, diarylamino, diheteroarylamino, arylheteroarylamino, alkyl, cycloalkyl, alkoxy, aryloxy, heteroaryloxy, arylthio, heteroarylthio or alkyl-substituted silyl, at least one hydrogen in which is optionally substituted by aryl, heteroaryl or alkyl, and R 5 ~R 7 and R 10 ~R 12The adjacent groups are optionally bonded to each other and together with the b ring or the d ring form an aromatic ring or a heteroaromatic ring, at least one hydrogen in the formed ring is optionally substituted by an aryl group, a heteroaryl group, a diarylamino group, a diheteroarylamino group, an arylheteroarylamino group, an alkyl group, a cycloalkyl group, an alkoxy group, an aryloxy group, a heteroaryloxy group, an arylthio group, a heteroarylthio group or an alkyl-substituted silyl group, at least one hydrogen in them is optionally substituted by an aryl group, a heteroaryl group or an alkyl group, and at least one hydrogen in the compound represented by formula (3) is optionally substituted by a cyano group, a halogen group or a deuterium group.

[0033] [4] The organic electroluminescent element according to any one of [1] to [3], wherein the host compound as the first component is a compound having a structure represented by the following formula (1-1), (2-1), (2-2) or (3-1).

[0034]

[0035] (In the above formulae, hydrogen is independently optionally substituted by aryl, heteroaryl, diarylamino, diheteroarylamino, arylheteroarylamino, alkyl, cycloalkyl, alkoxy or aryloxy, which are optionally further substituted by at least one selected from aryl, heteroaryl and alkyl.)

[0036] [5] The organic electroluminescent device according to [3] or [4], wherein the compound represented by any of the above formulae (1) to (3) contains at least one structure selected from the following partial structure group A.

[0037] Partial structure group A:

[0038]

[0039] (In the above partial structural formula, Me represents a methyl group, and the wavy line represents a bonding position. In the above partial structural formula, the hydrogen in each of the above partial structural formulas is optionally substituted by an aryl, heteroaryl, diarylamino, diheteroarylamino, arylheteroarylamino, alkyl, alkoxy or aryloxy group, the hydrogen in the aforementioned aryl is optionally further substituted by an aryl, heteroaryl or alkyl group, the hydrogen in the aforementioned heteroaryl is optionally further substituted by an aryl, heteroaryl or alkyl group, the hydrogen in the aforementioned diarylamino is optionally further substituted by an aryl, heteroaryl or alkyl group, the hydrogen in the aforementioned diheteroarylamino is optionally further substituted by an aryl, heteroaryl or alkyl group, and the hydrogen in the aforementioned arylheteroarylamino is optionally further substituted by an aryl, heteroaryl or alkyl group.)

[0040] [6] The organic electroluminescent element according to any one of [1] to [5], wherein the first component, the second component and the third component satisfy at least any one of the following formulae (a) to (c).

[0041] |Ip(1)|≥|Ip(2)|…Formula (a)

[0042] [In formula (a), Ip(1) represents the ionization potential of the first component, and Ip(2) represents the ionization potential of the second component.]

[0043] |Eg(2)|≥|Eg(3)|…Formula (b)

[0044] [In formula (b), Eg(2) represents the energy difference between the ionization potential and the electron affinity of the second component, and Eg(3) represents the energy difference between the ionization potential and the electron affinity of the third component.]

[0045] ΔEST(1)≥ΔEST(2)…Formula (c)

[0046] [In formula (c), ΔEST(1) represents the energy difference between the excited singlet energy level and the excited triplet energy level of the first component, and ΔEST(2) represents the energy difference between the excited singlet energy level and the excited triplet energy level of the second component.]

[0047] [7] The organic electroluminescent element according to any one of [1] to [6], wherein the full width at half maximum (FWHM) of the fluorescence peak of the third component is 35 nm or less.

[0048] [8] The organic electroluminescent element according to any one of [1] to [7], wherein the third component is a compound comprising a structure represented by the following formula (ED11), (ED12), (ED13), (ED14), (ED15), (ED16), (ED17), (ED18), (ED19), (ED21), (ED22), (ED23), (ED24), (ED25), (ED26), (ED27), (ED211), (ED212), (ED221), (ED222), (ED223), (ED231), (ED241), (ED242), (ED261) or (ED271).

[0049]

[0050]

[0051]

[0052] (Among the above formulas,

[0053] The hydrogen is each independently optionally substituted by aryl, heteroaryl, diarylamino, diheteroarylamino, arylheteroarylamino, alkyl, cycloalkyl, alkoxy or aryloxy, which are optionally further substituted by at least one selected from aryl, heteroaryl and alkyl.)

[0054] [9] The organic electroluminescent element according to any one of [1] to [8], wherein the second component is a compound having a structure represented by the following formula (AD11), (AD12), (AD13), (AD21) or (AD22).

[0055]

[0056] (In the above formulas, R 7 or R 8 is an alkyl group having 1 to 6 carbon atoms, wherein each hydrogen is independently substituted by an aryl group, a heteroaryl group, a diarylamino group, a diheteroarylamino group, an arylheteroarylamino group, an alkyl group, a cycloalkyl group, an alkoxy group or an aryloxy group, and each of these is further substituted by at least one selected from an aryl group, a heteroaryl group and an alkyl group.

[0057]

[10] The organic electroluminescent element according to any one of [1] to [9], wherein the second component contains at least one compound represented by the following formula (AD31) as the thermally activated delayed phosphor.

[0058]

[0059] (In the above formula (AD31), M is independently a single bond, -O-, at least one of >N-Ar and >CAr2, Ar in the above >N-Ar and >CAr2 is an aryl group, and Q is a group represented by any of the partial structural formulas (Q1) to (Q26). n is an integer from 1 to 5, and the hydrogen in the above formula is independently optionally substituted by an aryl group having 6 to 18 carbon atoms, a heteroaryl group having 6 to 18 carbon atoms, an alkyl group having 1 to 6 carbon atoms, and a cycloalkyl group having 3 to 12 carbon atoms, and at least one hydrogen in the compounds represented by the above formulas is optionally substituted by a halogen or deuterium.)

[0060]

[0061]

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

[10] , wherein the second component contains at least one compound having a structure represented by any of the following formulas (AD3101) to (AD3118) as the thermally activated delayed phosphor.

[0062]

[0063]

[12] The organic electroluminescent element according to any one of [1] to

[11] , wherein the third component contains, as the phosphor, a compound having at least one structure selected from the following partial structure group B.

[0064] Partial structure group B:

[0065]

[0066] (In the above partial structural formula, Me represents a methyl group, t Bu and t-Bu represent tert-butyl groups, and the wavy line indicates the bonding position.

[0067] Wherein, the hydrogen in the above-mentioned partial structural formulas is independently optionally substituted by aryl, heteroaryl, diarylamino, diheteroarylamino, arylheteroarylamino, alkyl, alkoxy or aryloxy, the hydrogen in the aforementioned aryl is optionally further substituted by aryl, heteroaryl or alkyl, the hydrogen in the aforementioned heteroaryl is optionally further substituted by aryl, heteroaryl or alkyl, the hydrogen in the aforementioned diarylamino is optionally further substituted by aryl, heteroaryl or alkyl, the hydrogen in the aforementioned diheteroarylamino is optionally further substituted by aryl, heteroaryl or alkyl, and the hydrogen in the aforementioned arylheteroarylamino is optionally further substituted by aryl, heteroaryl or alkyl.)

[0068]

[13] A display device comprising the organic electroluminescent element according to any one of [1] to

[12] .

[0069]

[14] A lighting device comprising the organic electroluminescent element according to any one of [1] to

[12] .

[0070] Effects of the Invention

[0071] The organic electroluminescent device of the present invention can achieve high luminous efficiency by including three components of a host compound, a thermally activated delayed phosphor and a phosphor in the luminescent layer, and making the host compound a compound having a boron atom and an oxygen atom in the molecule. BRIEF DESCRIPTION OF THE DRAWINGS

[0072] Figure 1 It is a schematic cross-sectional view showing the organic EL element of this embodiment. DETAILED DESCRIPTION

[0073] Hereinafter, the present invention will be described in detail. The description of the constituent conditions described below is sometimes based on representative embodiments and specific examples, but the present invention is not limited to such embodiments. It should be noted that in this specification, the numerical range represented by "to" refers to the range including the numerical values ​​described before and after "to" as the lower limit and the upper limit.

[0074] (Organic electroluminescent element)

[0075] The organic electroluminescent element of the present invention is an organic electroluminescent element whose light-emitting layer includes a first component to a third component. As the first component, a host compound having a boron atom and an oxygen atom in the molecule is used. As the second component, a thermally activated delayed phosphor having a difference ΔEST(2) between an excited singlet energy level and an excited triplet energy level of 0.20 eV or less is used. As the third component, a phosphor is used. Here, the excited triplet energy level and the excited singlet energy level used to determine ΔEST(2) are set to the excited triplet energy level and the excited singlet energy level before and after the reverse intersystem crossing. For example, it can be the lowest excited triplet energy level and the lowest excited singlet energy level, it can be a high-order excited triplet energy level and the lowest excited singlet energy level, or it can be a high-order excited triplet energy level and a high-order excited singlet energy level. Here, the high-order excited triplet energy level and the high-order excited singlet energy level refer to the lowest excited triplet energy level, the excited triplet energy level with energy higher than the lowest excited singlet energy level, and the excited singlet energy level, respectively. As described later, the lowest excited singlet energy level and the lowest excited triplet energy level can be obtained by the peak of the short wavelength side of the fluorescence spectrum and the phosphorescence spectrum. The high-order excited triplet energy level and the high-order excited singlet energy level can be inferred by the method described in the paper (Nature Materials, 18, 2019, 1084-1090) of Noda, Nakanoya, Anda, et al., Kyushu University and using partial structures. Alternatively, it can be obtained by the calculation recorded in the paper (Scientific Reports, 7: 4820, DOI: 10.1038 / s41598-017-05007-7) of Sato, et al., Kyoto University.

[0076] The “host compound” in the present invention refers to a compound having an excited singlet energy level obtained from the shoulder on the short-wavelength side of the peak of the fluorescence spectrum higher than that of the thermally activated delayed phosphor as the second component and the phosphor as the third component.

[0077] "Thermal activation type delayed phosphor" refers to: a compound that can absorb thermal energy and undergo reverse intersystem crossing from the excited triplet state to the excited singlet state, and can undergo radiative deactivation from the excited singlet state to emit delayed fluorescence. Here, "thermal activation type delayed phosphor" also includes phosphors that go through higher-order triplet states during the excitation process from the excited triplet state to the excited singlet state. The luminescence mechanism of emitting fluorescence through higher-order triplet states is called the FvHT (Fluorescence via Higher Triplet) mechanism. For this, for example, the paper by Monkman et al. of Durham University (NATURE COMMUNICATIONS, 7: 13680, DOI: 10.1038 / ncomms13680), the paper by Hosokai et al. of the National Institute of Advanced Industrial Science and Technology (Hosokai et al., Sci. Adv. 2017; 3: e1603282), and the paper by Sato et al. of Kyoto University (Scientific Reports, 7: 4820, DOI: 10.1038 / s41598-017-05007-7) and the academic publication by Sato et al. of Kyoto University (98th Spring Annual Meeting of the Chemical Society of Japan, Publication No.: 2I4-15, Mechanism of efficient luminescence in organic EL using DABNA as a luminescent molecule (Mechanism of efficient luminescence in organic EL using DABNA as a luminescent molecule), Graduate School of Engineering, Kyoto University), etc. In the present invention, when the fluorescence lifetime of a sample containing the target compound is measured at 300K, the target compound is determined to be a "thermally activated delayed fluorescent body" based on the observation of a slow fluorescence component. Here, "slow fluorescence component" refers to a fluorescence lifetime of 0.1 μ second or more. In contrast, the fluorescence lifetime of fluorescence emitted from an excited singlet state generated by a direct transition from a base singlet state is generally 0.1 n seconds or less. In the following description, fluorescence having a lifetime of 0.1 nanoseconds or less is referred to as a “fast fluorescence component.” The fluorescence emitted by the “thermally activated delayed phosphor” used in the present invention may contain both a slow fluorescence component and a fast fluorescence component.

[0078] The fluorescence lifetime can be measured using, for example, a fluorescence lifetime measuring apparatus (manufactured by Hamamatsu Photonics, C11367-01).

[0079] The ΔEST(2) of the second component is the energy difference obtained by subtracting the excited triplet energy level E(2,T,PT) obtained from the peak of the short wavelength side of the phosphorescence spectrum from the excited singlet energy level E(2,S,PT) obtained from the peak of the short wavelength side of the fluorescence spectrum, that is, the value calculated by E(2,S,PT)-E(2,T,PT). ΔEST(2) is 0.20 eV or less, preferably 0.15 eV or less, and more preferably 0.10 eV or less.

[0080] “Phosphor” refers to a compound that can emit fluorescence by radiative deactivation from an excited singlet state. The phosphor may be a common phosphor in which only a fast fluorescent component is observed when the fluorescence lifetime is measured at 300K, or a delayed phosphor in which both a fast fluorescent component and a slow fluorescent component are observed. The excited singlet energy level of the phosphor obtained from the shoulder on the short-wavelength side of the peak of the fluorescence spectrum is preferably lower than that of the host compound as the first component and the thermally activated delayed phosphor as the second component.

[0081] In the present invention, the "phosphor" can function as a luminescent dopant, and the "thermally activated delayed phosphor" can function as an auxiliary dopant that assists the phosphor in luminescence. In the following description, an organic electroluminescent element using a thermally activated delayed phosphor as an auxiliary dopant is sometimes referred to as a "TAF element" (TADF Assisting Fluorescence element). In a TAF element, the excited triplet energy is converted into excited singlet energy by reverse intersystem crossing in the thermally activated delayed phosphor, so that the excited singlet energy can be efficiently supplied to the phosphor and assist in luminescence. Thus, high luminescence efficiency is obtained.

[0082] In the present invention, particularly by making the light-emitting layer contain a host compound having a boron atom and an oxygen atom in the molecule, significantly higher light emission efficiency can be achieved compared to a three-component system using a conventional host compound. This is considered to be due to the following reasons.

[0083] That is, the main compound (first component) such as mCBP used in general TAF elements has a higher hole transport property than an electron transport property. Therefore, in the previous TAF elements, a large amount of auxiliary dopants (second component) as thermally activated delayed phosphors were added to the light-emitting layer to compensate for the electron transport property. In contrast, the main compound having boron atoms and oxygen atoms in the molecule used in the present invention has the advantage of high electron transport because the boron atom is rich in electron accepting properties and the oxygen atom has a high electronegativity. Therefore, it can be inferred that by using a main compound having boron atoms and oxygen atoms, the charge transport burden caused by the auxiliary dopant will be reduced and the light-emitting site will be adjusted, and the luminous efficiency and element life will be improved.

[0084] The energy levels of the first component, the second component, and the third component used in the present invention preferably satisfy at least any one of the following formulas (a) to (c), and more preferably satisfy all of the conditions.

[0085] |Ip(1)|≥|Ip(2)|…Formula (a)

[0086] In formula (a), Ip(1) represents the ionization potential of a host compound as a first component, and Ip(2) represents the ionization potential of a thermally activated delayed phosphor as a second component.

[0087] |Eg(2)|≥|Eg(3)|…Formula (b)

[0088] In formula (b), Eg(2) represents the energy difference between the ionization potential and the electron affinity of the thermally activated delayed phosphor as the second component, and Eg(3) represents the energy difference between the ionization potential and the electron affinity of the phosphor as the third component.

[0089] ΔEST(1)≥ΔEST(2)…Formula (c)

[0090] In formula (c), ΔEST(1) represents the energy difference between the excited singlet energy level and the excited triplet energy level of the main compound as the first component, and ΔEST(2) represents the energy difference between the excited singlet energy level and the excited triplet energy level of the thermally activated delayed phosphor as the second component. Here, the excited singlet energy level is the excited singlet energy level E(1,S,PT) and E(2,S,PT) obtained from the peak on the short wavelength side of its fluorescence spectrum, and the excited triplet energy level is the excited triplet energy level E(1,T,PT) and E(2,T,PT) obtained from the peak on the short wavelength side of its phosphorescence spectrum. Their meanings are described below.

[0091] By making the first component and the second component satisfy formula (a), the holes transported by the first component are efficiently transferred to the second component. In addition, by making the second component and the third component satisfy formula (b), when the carriers in the second component recombine, a large excitation energy is generated, and the excited singlet energy and the excited singlet energy generated by reverse intersystem crossing from the excited triplet state to the excited singlet state are efficiently supplied to the third component. Furthermore, by making the first component and the second component satisfy formula (c), reverse intersystem crossing occurs in the second component, and the excited triplet energy is converted into excited singlet energy, and the excited singlet energy is supplied to the phosphor. In summary, by making the first component, the second component and the third component satisfy formulas (a) to (c), the excited singlet energy is efficiently supplied to the phosphor, and a higher luminous efficiency can be obtained.

[0092] Furthermore, if the excited triplet energy level E(1, T, PT) of the first component obtained from the peak on the short wavelength side of the phosphorescence spectrum is higher than the excited triplet energy level E(2, T, PT) of the second component obtained from the peak on the short wavelength side of the phosphorescence spectrum, the excited triplet energy generated in the first component is easily transferred to the second component, and the excited triplet energy is confined in the molecule of the second component, promoting the reverse intersystem crossing in the second component. As a result, the excited singlet energy is more efficiently supplied to the third component, and a higher luminous efficiency is obtained. Specifically, E(1, T, PT) is preferably higher than E(2, T, PT) by 0.01 eV or more, more preferably higher by 0.03 eV or more, and further preferably higher by 0.1 eV or more.

[0093] On the other hand, the phosphor as the third component preferably has a luminescence peak with a full width at half maximum FWHM of 35 nm or less in the range of 440 to 590 nm of its fluorescence spectrum. In the use of blue light-emitting elements, 450 to 475 nm is more preferred, and 455 to 465 nm is further preferred. In the use of green light-emitting elements, 490 to 590 nm is more preferred, and 510 to 550 nm is further preferred. The full width at half maximum FWHM of the luminescence peak being 35 nm or less means that the color purity of the luminescence is high. Therefore, by using such a phosphor, an organic light-emitting element with good color can be realized.

[0094] In this specification, ionization potential (Ip) refers to the ionization potential (Ip) based on photoelectron yield spectroscopy, energy gap (Eg) refers to the optical band gap obtained from the intersection of the tangent line and the baseline of the absorption peak on the longest wavelength side of the spectrum obtained by ultraviolet-visible absorption spectrum, and electron affinity (Ea) refers to the electron affinity obtained by subtracting Eg from Ip.

[0095] In addition, in this specification, for the host compound as the first component, the excited singlet energy level obtained from the shoulder on the short wavelength side of the peak of its fluorescence spectrum is expressed as E(1, S, Sh), the excited singlet energy level obtained from the peak top on the short wavelength side of the fluorescence spectrum is expressed as E(1, S, PT), the excited singlet energy level obtained from the shoulder on the short wavelength side of the peak of the phosphorescence spectrum is expressed as E(1, T, Sh), and the excited triplet energy level obtained from the peak top on the short wavelength side of the phosphorescence spectrum is expressed as E(1, T, PT). In addition, the energy difference calculated by E(1, S, PT)-E(1, T, PT) is expressed as ΔEST(1). For each energy level and energy difference of the second component and the third component, the symbol "1" in the first component is changed to "2" in the case of the second component, and is changed to "3" in the case of the third component. In addition, the above-mentioned E(1,S,Sh), E(2,S,Sh), and E(3,S,Sh) are collectively referred to as E(S,Sh), E(1,S,PT), E(2,S,PT), and E(3,S,PT) are collectively referred to as E(S,PT), E(1,T,Sh), E(2,T,Sh), and E(3,T,Sh) are collectively referred to as E(T,Sh), E(1,T,PT), E(2,T,PT), and E(3,T,PT) are collectively referred to as E(T,PT), and ΔEST(1), ΔEST(2), and ΔEST(3) are collectively referred to as ΔEST.

[0096] In the present invention, the excited singlet energy level E(S, Sh) obtained from the shoulder on the short-wavelength side of the peak of the fluorescence spectrum, the excited singlet energy level E(S, PT) obtained from the peak top on the short-wavelength side of the fluorescence spectrum, the excited triplet energy level E(T, Sh) obtained from the shoulder on the short-wavelength side of the peak of the phosphorescence spectrum, the excited triplet energy level E(T, PT) obtained from the peak top on the short-wavelength side of the phosphorescence spectrum, the reverse intersystem crossing velocity and the luminescence velocity are calculated as follows.

[0097] Here, the “shoulder on the short wavelength side of the peak” refers to the inflection point on the short wavelength side of the luminescence peak, and the “peak top on the short wavelength side” refers to the position on the peak corresponding to the luminescence maximum on the shortest wavelength side among the luminescence maximum values ​​of the luminescence peak.

[0098] In addition, as a measurement sample for measuring each energy level, when the target compound is a main compound or an auxiliary dopant, a single film of the target compound formed on a glass substrate (Neat film, thickness: 50nm) is used, and when the target compound is a light-emitting dopant, a polymethyl methacrylate film (thickness: 10μm, concentration of the target compound: 1 weight%) in which the target compound is dispersed formed on a glass substrate is used. The film thickness of the polymethyl methacrylate film in which the target compound is dispersed can be set to a film thickness that is sufficient for measuring the absorption spectrum, fluorescence spectrum, and phosphorescence spectrum, and can be set thicker when the intensity is weak and thicker when the intensity is strong. The excitation light uses the wavelength of the absorption peak obtained in the absorption spectrum, and the data obtained from the following luminescence peaks among the luminescence peaks appearing in the fluorescence spectrum or the phosphorescence spectrum are used to obtain each energy level, and the luminescence peaks appear in the range of 400 to 500nm in the case of blue luminescence, in the range of 480 to 600nm in the case of green luminescence, and in the range of 580 to 700nm in the case of red. Furthermore, when the absorption peak and the emission peak are close to each other and the excitation light is mixed in the emission peak, the absorption peak or absorption shoulder on the shorter wavelength side may be used.

[0099] [1] Excited singlet energy level E(S,Sh) obtained from the shoulder on the short-wavelength side of the peak of the fluorescence spectrum

[0100] The sample containing the target compound was irradiated with excitation light at 77 K to observe the fluorescence spectrum. For the emission peak appearing in the fluorescence spectrum, a tangent line passing through the inflection point (shoulder) on the short wavelength side was drawn, and the wavelength (B) of the intersection of the tangent line and the baseline was calculated using the following formula. Sh )[nm] Calculate the excited singlet energy level E(S,Sh).

[0101] E(S,Sh)[eV]=1240 / B Sh

[0102] [2] Excited singlet energy level E(S,PT) obtained from the peak on the short wavelength side of the fluorescence spectrum

[0103] The measurement sample containing the target compound is irradiated with excitation light at 77 K to observe the fluorescence spectrum. The wavelength corresponding to the peak top on the shortest wavelength side of the emission peak appearing in the fluorescence spectrum (maximum emission wavelength, B PT )[nm], the excited singlet energy level E(S,PT) is calculated using the following formula.

[0104] E(S,PT)[eV]=1240 / BPT

[0105] [3] The excited triplet energy level E(T,Sh) obtained from the shoulder on the short-wavelength side of the peak of the phosphorescence spectrum

[0106] The sample containing the target compound was irradiated with excitation light at 77 K to observe the phosphorescence spectrum. For the emission peak appearing in the phosphorescence spectrum, a tangent line passing through the inflection point (shoulder) on the short wavelength side was drawn, and the wavelength (C Sh )[nm] Calculate the excited triplet energy level E(T,Sh).

[0107] E(T,Sh)[eV]=1240 / C Sh

[0108] [4] The excited triplet energy level E(T,PT) obtained from the peak on the short-wavelength side of the phosphorescence spectrum

[0109] The sample containing the target compound was irradiated with excitation light at 77 K to observe the phosphorescence spectrum. The wavelength corresponding to the peak top on the shortest wavelength side of the emission peak appearing in the phosphorescence spectrum (maximum emission wavelength, C PT )[nm], and the excited triplet energy level E(T,PT) is calculated using the following formula.

[0110] E(T,PT)[eV]=1240 / C PT

[0111] It can be considered here that: in DA (donor-acceptor) type TADF materials and MRE (Multi Resonance Effect) type compounds, since the emission width of the fluorescence spectrum and the phosphorescence spectrum varies depending on the firmness of the molecules, even if the maximum emission wavelength is the same, the DA type TADF compound has a wider energy than the MRE type compound molecule. The TAF element needs to accurately estimate the energy transfer between the components to design the structure, so the excited singlet energy level and the excited triplet energy level are estimated by the shoulder on the short wavelength side of the spectrum. In general, the intersection of the tangent line passing through the inflection point on the short wavelength side of the spectrum and the baseline is used as the energy obtained by the shoulder on the short wavelength side.

[0112] The excited singlet energy level E(S, PT) and the excited triplet energy level E(T, PT) obtained from the peak are used for calculation and discussion of ΔEST. The excited singlet energy level E(S, Sh) and the excited triplet energy level E(T, Sh) obtained from the shoulder on the short-wavelength side of the spectrum are used for discussion of energy confinement and transfer between the host compound as the first component and the auxiliary dopant, and energy confinement and transfer between the auxiliary dopant and the luminescent dopant.

[0113] (5) Reverse intersystem jumping velocity

[0114] The reverse intersystem crossing velocity refers to the speed of reverse intersystem crossing from the excited triplet state to the excited singlet state. The reverse intersystem crossing velocity of the auxiliary dopant and the luminescent dopant can be measured by transient fluorescence spectroscopy and calculated using the method described in Nat. Commun. 2015, 6, 8476. or Organic Electronics 2013, 14, 2721-2726. Specifically, the reverse intersystem crossing velocity of the auxiliary dopant is 10 5 s -1 , more preferably 10 6 s -1 .

[0115] (6) Luminescence speed

[0116] The luminescence rate refers to the rate of transition from the self-excited singlet state to the ground state without undergoing the TADF process. The luminescence rate of the auxiliary dopant and the luminescent dopant can be calculated similarly to the reverse intersystem crossing rate using the method described in Nat. Commun. 2015, 6, 8476. or Organic Electronics 2013, 14, 2721-2726. Specifically, the reverse intersystem crossing rate of the luminescent dopant is 10 7 s -1 , more preferably 10 8 s -1 .

[0117] Hereinafter, each layer and each material constituting the light-emitting element of the present invention will be described.

[0118] 1. Luminous layer

[0119] The light-emitting layer includes a host compound as a first component, a thermally activated delayed phosphor as a second component, and a phosphor as a third component. Here, the host compound is a compound having a boron atom and an oxygen atom in the molecule, and the difference ΔEST(2) between the excited singlet energy level and the excited triplet energy level of the thermally activated delayed phosphor is less than 0.20 eV. Here, the compounds constituting the first component to the third component may be one or more.

[0120] In this specification, the thermally activated delayed phosphor as the second component may be referred to as an "auxiliary dopant" (compound), and the phosphor as the third component may be referred to as a "luminescent dopant" (compound).

[0121] The light-emitting layer may be a single layer or may be composed of multiple layers. In addition, the main compound, the thermally activated delayed phosphor and the phosphor may be contained in the same layer, or may each contain at least one component in the multiple layers. The main compound, the thermally activated delayed phosphor and the phosphor contained in the light-emitting layer may be one type or a combination of multiple types. The auxiliary dopant and the light-emitting dopant may be contained in the main compound as a matrix as a whole, or may be partially contained in the main compound as a matrix. The light-emitting layer doped with the auxiliary dopant and the light-emitting dopant may be formed by the following methods, etc.: a method of forming a film of the main compound, the auxiliary dopant and the light-emitting dopant by a ternary co-evaporation method; a method of simultaneously evaporating the main compound, the auxiliary dopant and the light-emitting dopant after pre-mixing the main compound, the auxiliary dopant and the light-emitting dopant; a wet film-forming method of applying a coating prepared by dissolving the main compound, the auxiliary dopant and the light-emitting dopant in an organic solvent.

[0122] The amount of the first component used as the main compound varies depending on the type of the main compound and the type of the second component, and can be determined according to the combination thereof. From the viewpoint of improving electron transport and optimal carrier balance, it is preferred that the first component is more, and the basis for the amount of the main compound is preferably 40 to 99.999 weight percent of the entire light-emitting layer material, more preferably 50 to 99.99 weight percent, and further preferably 60 to 99.9 weight percent. If it is the above range, it is preferred from the viewpoint of, for example, efficient charge transport and efficient movement of energy to dopants.

[0123] The amount of the second component used as an auxiliary dopant (thermally activated delayed phosphor) varies depending on the type of auxiliary dopant and can be determined according to the characteristics of the auxiliary dopant. From the viewpoint of efficient recombination on the compound, it is preferred that the second component is more, and the basis for the amount of the auxiliary dopant is preferably 1 to 60% by weight of the total material for the light-emitting layer, more preferably 2 to 50% by weight, and further preferably 5 to 30% by weight. If it is within the above range, it is preferred from the viewpoint of, for example, being able to efficiently recombine on the auxiliary dopant and move energy to the light-emitting dopant. Here, in the present invention, since the electron transportability of the main compound is high, there is no need to use an auxiliary dopant to compensate for the electron transportability. Therefore, there is an advantage in being able to select the amount of the thermally activated delayed phosphor by focusing on the function as an auxiliary dopant.

[0124] The amount of the third component as a luminescent dopant (phosphor) varies depending on the type of luminescent dopant and can be determined according to the characteristics of the luminescent dopant. The basis for the amount of the luminescent dopant is preferably 0.001 to 30% by weight of the total material for the luminescent layer, more preferably 0.01 to 20% by weight, and further preferably 0.1 to 10% by weight. In general, molecules with high planarity and molecules that utilize the multiple resonance effect are prone to aggregation, so it is preferred to use a small amount. In addition, from the perspective of efficient recombination on the second component, it is also preferred to use a small amount. On the other hand, from the perspective of process ease, it is preferred to use a large amount because the process margin can be widened. If it is within the above range, it is preferred from the perspective of, for example, a controllable process and preventing concentration quenching and efficient recombination on the second component.

[0125] From the viewpoint of the efficiency of the thermally activated delayed fluorescence mechanism of the auxiliary dopant, it is preferred that the light-emitting dopant be used in a lower concentration than the auxiliary dopant.

[0126] 1-1. Main compound

[0127] In the present invention, a host compound having a boron atom and an oxygen atom in its molecule is used as the first component of the light-emitting layer.

[0128] The main compound having a boron atom and an oxygen atom in the molecule is preferably a polycyclic aromatic compound having a structure in which three aromatic rings are bonded to the boron atom, at least one of the aromatic rings is connected to the other two aromatic rings via a connecting group, and at least one of the connecting groups is an oxy group (-O-) (hereinafter referred to as "polycyclic aromatic compound having a boron atom and an oxygen atom").

[0129] Polycyclic aromatic compounds with boron and oxygen atoms have large HOMO-LUMO gaps and high excited triplet energy levels (E T ). It is speculated that the reason is that the aromatic property of the aromatic ring containing the hetero element is low, so the reduction of the HOMO-LUMO gap associated with the expansion of the conjugated system is suppressed, and the two SOMOs (single occupied molecular orbitals; Single Occupied Molecular Orbital), namely SOMO1 and SOMO2, of the excited triplet state (T1) are localized due to the electronic perturbation of the hetero element. Polycyclic aromatic compounds containing boron atoms and oxygen atoms have high excited triplet energy levels, and therefore can be particularly preferably used as a host for confining excited triplet energy into the molecules of thermally activated delayed fluorescent materials.

[0130] In addition, in the host compound as the first component, it is preferable to select the structure in consideration of the following points.

[0131] That is, from the viewpoint of reducing the interaction and obtaining a high excited triplet energy, the first component preferably adopts a structure in which the aggregation is reduced. Specifically, the molecular structure of the first component is preferably an asymmetric structure, preferably having a large dihedral angle in the molecule, or preferably having steric hindrance in the molecule. In addition, from the viewpoint of improving charge transport and energy mobility, it is preferred that the orbits associated with charge transport are close. In addition, from the viewpoint of the stability of the element characteristics when the element is driven, the glass transition temperature (Tg) of the first component is preferably high, and for this reason, it is preferred to introduce a structure in which interactions occur between molecules.

[0132] It should be noted that, in order to suppress the aggregation between the components, as the first component and the second component, both compounds with low aggregation properties may be used, or either of them may be used. The aggregation property can be estimated based on the red shift degree of the spectrum of the low-concentration uniform dispersion state and the single-component vapor-deposited film, or the red shift degree of the spectrum of the co-evaporated film of the first component and the second component and the spectrum of the second component in the low-concentration uniform dispersion state.

[0133] Examples of the host compound having a boron atom and an oxygen atom in the molecule include compounds represented by any of the following formulae (i), (ii) and (iii).

[0134] 1-1-1. Compound represented by formula (i)

[0135]

[0136] In formula (i), ring A, ring B and ring C are each independently an aromatic ring or a heteroaromatic ring, and at least one hydrogen atom in these rings is optionally substituted. For the description, preferred range and specific examples of the substituents that may optionally replace the hydrogen atoms in ring A, ring B and ring C, refer to R in formula (1). 1 ~R 11 Description, preferred range and specific examples of the substituents in .

[0137] Furthermore, at least one hydrogen atom in the compound or structure represented by formula (i) may be substituted with cyano, halogen or deuterium in addition to the above-mentioned substituents.

[0138] An "aromatic ring" or "heteroaromatic ring" is a non-valent ring of an aryl group or a heteroaryl group. When the number of carbon atoms in an aromatic ring or a heteroaromatic ring is mentioned, the number of carbon atoms in the ring before fusion is included.

[0139] The compound represented by formula (i) is preferably a compound represented by the following formula (1).

[0140]

[0141] In formula (1), R 1 ~R 11Each independently represents hydrogen or a substituent. 1 ~R 11 The number of substituents is not particularly limited. 1 ~R 11 One or two or more of them may be substituents, or none of them may be unsubstituted (i.e., they may be hydrogen atoms). 1 ~R 11 When two or more of the substituents are substituents, these substituents may be the same or different. Here, since steric hindrance is not likely to increase, R can be added without limitation. 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 9 , R 10 and R 11 On the other hand, from the viewpoint of adjusting the HOMO energy level and the LUMO energy level, in order to deepen the HOMO energy level, it is preferred that R 1 , R 3 , R 4 , R 6 , R 9 and R 11 At least one of them is an electron-withdrawing substituent. On the contrary, in order to make the HOMO level shallower, it is preferred that R 1 , R 3 , R 4 , R 6 , R 9 and R 11 At least one of them is an electron donating substituent. In order to deepen the LUMO energy level, it is preferred that R 2 , R 5 and R 10 At least one of them is an electron-withdrawing substituent. On the contrary, in order to make the LUMO energy level shallower, it is preferred that R 2 , R 5 and R 10 At least one of them is an electron donating substituent.

[0142] In addition, it is preferred that the surface formed by the aromatic ring formed by the a-c rings and the boron atom and the oxygen atom is bonded to R 1 ~R 11The interaction between molecules is controlled by the dihedral angle of the plane formed by the substituents in. That is, the compound represented by formula (1) and the compound represented by formula (AD11), (AD12), (AD13), (AD21) or (AD22) described later as an example of the second component have high planarity. Therefore, by adopting a structure in which the above-mentioned dihedral angle becomes larger, the aggregation caused by planarity, the interaction between the main molecules and the main molecule-dopant molecules are effectively reduced. As a result, the red shift and broadening of the luminescence spectrum are suppressed, and deep blue luminescence and high color purity can be achieved. The dihedral angle of the molecule can be obtained by a semi-empirical molecular orbital calculation such as MOPAC.

[0143] In formula (1), R 1 ~R 11 Each independently is preferably hydrogen, aryl, heteroaryl, diarylamino, diheteroarylamino, arylheteroarylamino, alkyl, cycloalkyl, alkoxy or aryloxy. Here, in addition to hydrogen among these groups, it is a substituent that replaces the hydrogen of the benzene ring corresponding to the a ring to the c ring. In the following description, these substituents are referred to as "first substituents". Among the first substituents, at least one hydrogen in aryl, heteroaryl, diarylamino, diheteroarylamino and arylheteroarylamino is optionally replaced by an aryl, heteroaryl, alkyl or cycloalkyl group. In the following description, the substituent that replaces the hydrogen of the first substituent is referred to as a "second substituent".

[0144] The "aryl group" as the first substituent may be a monocyclic ring, a condensed ring formed by condensing two or more aromatic hydrocarbon rings, or a connected ring formed by connecting two or more aromatic hydrocarbon rings. When two or more aromatic hydrocarbon rings are connected, they may be connected in a straight chain or in a branched form. As for the "aryl group" as the first substituent, for example, an aryl group having 6 to 30 carbon atoms may be listed, preferably an aryl group having 6 to 24 carbon atoms, more preferably an aryl group having 6 to 20 carbon atoms, further preferably an aryl group having 6 to 16 carbon atoms, particularly preferably an aryl group having 6 to 12 carbon atoms, and most preferably an aryl group having 6 to 10 carbon atoms.

[0145] Specific examples of the aryl group include phenyl as a monocyclic aryl group; biphenyl (2-biphenyl, 3-biphenyl, 4-biphenyl) as a bicyclic aryl group; naphthyl (1-naphthyl, 2-naphthyl) as a condensed bicyclic aryl group; terphenyl (m-terphenyl-2'-yl, m-terphenyl-4'-yl, m-terphenyl-5'-yl, o-terphenyl-3'-yl, o-terphenyl-4'-yl, p-terphenyl) as a tricyclic aryl group. terphenyl-2'-yl, m-terphenyl-2-yl, m-terphenyl-3-yl, m-terphenyl-4-yl, o-terphenyl-2-yl, o-terphenyl-3-yl, o-terphenyl-4-yl, p-terphenyl-2-yl, p-terphenyl-3-yl, p-terphenyl-4-yl); acenaphthenyl (acenaphthene-1-yl, acenaphthene-3-yl, acenaphthene-4-yl, acenaphthene-5-yl) as a fused tricyclic aromatic group, fluorenyl (fluoren-1-yl, fluoren-2-yl as tetracyclic aromatic groups; as condensed tetracyclic aromatic groups; as terphenyl groups (5'-phenyl-m-terphenyl-2-yl, 5'-phenyl-m-terphenyl-3-yl, 5'-phenyl-m-terphenyl-4-yl, m-terphenyl); as condensed tetracyclic aromatic groups; as terphenyl groups (1-phenanthrenyl, 2-phenanthrenyl, 3-phenanthrenyl, 4-phenanthrenyl, 9-phenanthrenyl); as tetracyclic aromatic groups (5'-phenyl-m-terphenyl-2-yl, 5'-phenyl-m-terphenyl-3-yl, 5'-phenyl-m-terphenyl-4-yl, m-terphenyl); as condensed tetracyclic aromatic groups; as terphenyl groups (1-phenanthrenyl, 2-phenanthrenyl, 3-phenanthrenyl, 4-phenanthrenyl, 9-phenanthrenyl); as tetracyclic aromatic groups (5'-phenyl-m-terphenyl-2-yl, 5'-phenyl-m-terphenyl-3-yl, 5'-phenyl-m-terphenyl-4-yl, m-terphenyl); as condensed tetracyclic aromatic groups; as terphenyl groups (1-phenanthrenyl, 2-phenanthrenyl, 3-phenanthrenyl, 4-phenanthrenyl, 9-phenanthrenyl); as terphenyl ...1-phenanthrenyl, 2-phenanthrenyl, 3-phenanthrenyl, 4-phenanthrenyl as a fused pentacyclic aromatic group, such as triphenylene (triphenylene-1-yl, triphenylene-2-yl), pyrene (pyrene-1-yl, pyrene-2-yl, pyrene-4-yl), tetraphenylene (tetracene-1-yl, tetracerene-2-yl, tetracerene-5-yl); as a fused pentacyclic aromatic group, such as perylene (perylene-1-yl, perylene-2-yl, perylene-3-yl), pentacene (pentacene-1-yl, pentacene-2-yl, pentacene-5-yl, pentacene-6-yl), etc.

[0146] For the description, preferred range and specific examples of the "aryl" in diarylamino as the first substituent, the "aryl" in arylheteroarylamino, the "aryl" in aryloxy, and the "aryl" as the second substituent, reference can be made to the relevant description, preferred range and specific examples of the "aryl" as the first substituent mentioned above.

[0147] The "heteroaryl" as the first substituent may be a monocyclic ring, or a condensed ring formed by condensing one or more heterocyclic rings with one or more heterocyclic rings or one or more aromatic hydrocarbon rings, or a connected ring formed by connecting two or more heterocyclic rings. When two or more heterocyclic rings are connected, they may be connected in a straight chain or in a branched form. Regarding the "heteroaryl" as the first substituent, for example, a heteroaryl having 2 to 30 carbon atoms may be listed, preferably a heteroaryl having 2 to 25 carbon atoms, more preferably a heteroaryl having 2 to 20 carbon atoms, further preferably a heteroaryl having 2 to 15 carbon atoms, and particularly preferably a heteroaryl having 2 to 10 carbon atoms. The heteroatoms in the heteroaryl group are not particularly limited, and examples thereof include oxygen, sulfur, and nitrogen. The heteroaryl group preferably contains a heterocycle containing 1 to 5 heteroatoms.

[0148] Specific examples of the heteroaryl group include furanyl, thienyl, pyrrolyl, oxazolyl, isoxazolyl, thiazolyl, isothiazolyl, imidazolyl, pyrazolyl, oxadiazolyl, furazanyl, thiadiazolyl, triazolyl, tetrazolyl, pyridyl, pyrimidinyl, pyridazinyl, pyrazinyl, triazinyl, benzofuranyl, isobenzofuranyl, dibenzofuranyl, benzo[b]thienyl, dibenzofuranyl, benzothiophenyl, indolyl, isoindolyl, 1H-indazolyl, benzimidazolyl, benzoxazolyl, benzothiazolyl, 1H-benzotriazolyl, quinolyl, isoquinolyl, cinnolinyl, quinazolinyl, quinoxalinyl, phthalazinyl, naphthyridinyl, purinyl, pteridinyl, carbazolyl, acridinyl, phenoxazinyl, phenothiazinyl, phenazinyl, phenoxathiol, thianthrenyl, indolizinyl, etc.

[0149] For the description, preferred range and specific examples of the "heteroaryl" in the diheteroarylamino group, the "heteroaryl" in the arylheteroarylamino group, and the "heteroaryl" as the second substituent, the relevant description, preferred range and specific examples of the "heteroaryl" as the first substituent can be referred to. In addition, the "heteroaryl" as the second substituent also includes a substituted heteroaryl in which at least one hydrogen in the heteroaryl is replaced by an aryl group such as a phenyl group or an alkyl group such as a methyl group. For the description, preferred range and specific examples of the aryl substituted on the "heteroaryl" as the second substituent, the relevant description, preferred range and specific examples of the "aryl" as the first substituent can be referred to. For the description, preferred range and specific examples of the alkyl substituted on the "heteroaryl" as the second substituent, the relevant description, preferred range and specific examples of the "alkyl" as the first substituent can be referred to. As an example of a substituted heteroaryl as the second substituent, a carbazolyl in which at least the hydrogen at the 9th position is replaced by an aryl group such as a phenyl group or an alkyl group such as a methyl group can be cited.

[0150] The "alkyl" as the first substituent may be any of a straight-chain alkyl group and a branched-chain alkyl group. As for the alkyl group as the first substituent, for example, an alkyl group having 1 to 24 carbon atoms can be listed, preferably an alkyl group having 1 to 18 carbon atoms, more preferably an alkyl group having 1 to 12 carbon atoms, further preferably an alkyl group having 1 to 6 carbon atoms, particularly preferably an alkyl group having 1 to 4 carbon atoms, and most preferably a methyl group. It should be noted that when the alkyl group as the first substituent is a branched-chain alkyl group, as the branched-chain alkyl group, for example, a branched-chain alkyl group having 3 to 24 carbon atoms can be listed, preferably a branched-chain alkyl group having 3 to 18 carbon atoms, more preferably a branched-chain alkyl group having 3 to 12 carbon atoms, further preferably a branched-chain alkyl group having 3 to 6 carbon atoms, and particularly preferably a branched-chain alkyl group having 3 to 4 carbon atoms can be listed.

[0151] Specific examples of the alkyl group include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, isopentyl, neopentyl, tert-pentyl, n-hexyl, 1-methylpentyl, 4-methyl-2-pentyl, 3,3-dimethylbutyl, 2-ethylbutyl, n-heptyl, 1-methylhexyl, n-octyl, tert-octyl, 1-methylheptyl, 2-ethylhexyl, 2-propylpentyl, n-nonyl, 2,2-dimethylheptyl, 2,6-dimethyl-4-heptyl, 3,5,5-trimethylhexyl, n-decyl, n-undecyl, 1-methyldecyl, n-dodecyl, n-tridecyl, 1-hexylheptyl, n-tetradecyl, n-pentadecyl, n-hexadecyl, n-heptadecyl, n-octadecyl, and n-eicosyl.

[0152] For the description, preferred range and specific examples of the "alkyl" as the second substituent, reference can be made to the description, preferred range and specific examples of the "alkyl" as the first substituent. In the first substituent, the substitution position of the alkyl as the second substituent is not particularly limited, and is preferably the 2nd or 3rd position, more preferably the 2nd position, based on the bonding position (1st position) of the first substituent on the a ring, b ring and c ring.

[0153] The "cycloalkyl" as the first substituent may be any of a cycloalkyl group containing one ring, a cycloalkyl group containing multiple rings, a cycloalkyl group containing a non-conjugated double bond in the ring, and a cycloalkyl group containing a branch outside the ring. The "cycloalkyl" as the first substituent may be, for example, a cycloalkyl group having 3 to 12 carbon atoms, preferably a cycloalkyl group having 5 to 10 carbon atoms, and more preferably a cycloalkyl group having 6 to 10 carbon atoms.

[0154] Specific examples of the cycloalkyl group include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, bicyclo[2,2,1]heptyl, bicyclo[2.2.2]octyl, decalinyl, and adamantyl.

[0155] For the description, preferred range and specific examples of the "cycloalkyl group" as the second substituent, refer to the description, preferred range and specific examples of the "cycloalkyl group" as the first substituent.

[0156] The "alkoxy" as the first substituent may be straight-chain or branched. As for the "alkoxy" as the first substituent, for example, an alkoxy group having 1 to 24 carbon atoms can be listed, preferably an alkoxy group having 1 to 18 carbon atoms, more preferably an alkoxy group having 1 to 12 carbon atoms, further preferably an alkoxy group having 1 to 6 carbon atoms, and particularly preferably an alkoxy group having 1 to 4 carbon atoms. It should be noted that when the alkoxy group as the first substituent is branched, as the branched alkoxy group, for example, a branched alkoxy group having 3 to 24 carbon atoms can be listed, preferably a branched alkoxy group having 3 to 18 carbon atoms, more preferably a branched alkoxy group having 3 to 12 carbon atoms, further preferably a branched alkoxy group having 3 to 6 carbon atoms, and particularly preferably a branched alkoxy group having 3 to 4 carbon atoms can be listed.

[0157] Specific examples of the alkoxy group include a methoxy group, an ethoxy group, a propoxy group, an isopropoxy group, a butoxy group, an isobutoxy group, a sec-butoxy group, a tert-butoxy group, a pentyloxy group, a hexyloxy group, a heptyloxy group, and an octyloxy group.

[0158] The compound represented by formula (1) preferably contains in the molecule at least one structure selected from the following partial structural group A. The compound represented by formula (1) may contain one structure selected from the partial structural group A or two or more structures.

[0159] Partial structure group A:

[0160]

[0161] In each partial structure, Me represents a methyl group, and the wavy line represents a bonding position. The bonding position indicated by the wavy line is any substitutable position of the benzene ring (including the benzene ring constituting the condensed ring) to which the connecting bond is attached. At least one hydrogen in each partial structure is independently optionally substituted by an aryl, heteroaryl, diarylamino, diheteroarylamino, arylheteroarylamino, alkyl, alkoxy or aryloxy group, wherein at least one hydrogen in the aryl, heteroaryl, diarylamino, diheteroarylamino and arylheteroarylamino is optionally further substituted by an aryl, heteroaryl or alkyl group. For the preferred range and specific examples of aryl, heteroaryl, diarylamino, diheteroarylamino, arylheteroarylamino, alkyl, alkoxy and aryloxy, reference can be made to R of formula (1). 1 ~R 11 The corresponding records.

[0162] In formula (1), R 1 ~R 11 At least one of them is preferably a group represented by any of the following formulae (1-a) to (1-n), and more preferably a group represented by the following formula (1-d).

[0163]

[0164] In formulas (1-a) to (1-n), * represents a bonding position. In formulas (1-d) and (1-i) to (1-n), the bonding position represented by * is any substitutable position of the benzene ring (including the benzene ring constituting the condensed ring) to which the connecting bond is attached. In formula (1-h), the group represented by *-O- is bonded to any substitutable position of the benzene ring to which the connecting bond is attached.

[0165] In formula (1-a) to formula (1-h), hydrogen may be optionally used as the above R 1 ~R 11 The "second substituent" in the above-mentioned may be substituted by an aryl group having 6 to 30 carbon atoms, a heteroaryl group having 2 to 30 carbon atoms, an alkyl group having 1 to 24 carbon atoms, or a cycloalkyl group having 3 to 12 carbon atoms.

[0166] In addition, R in formula (1-i), formula (1-j) and formula (1-k) each independently represents hydrogen, or as the above R 1 ~R 11 The "second substituent" in the formula (a) is an aryl group having 6 to 30 carbon atoms, a heteroaryl group having 2 to 30 carbon atoms, an alkyl group having 1 to 24 carbon atoms, or a cycloalkyl group having 3 to 12 carbon atoms. The position to which R is bonded is any substitutable position of the benzene ring (including the benzene ring constituting the condensed ring) to which the connecting bond is attached.

[0167] R 1 ~R 11 When the groups represented by any of the formulae (1-a) to (1-n) are used, their number and position are not particularly limited. 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 9 , R 10 and R 11 At least one of the groups is set to be a group represented by any of the formulae (1-a) to (1-n). In order to deepen the HOMO level, it is preferred that R 1 , R 3 , R 4 , R 6 , R 9 and R 11 At least one of the groups is a group represented by any of the formulae (1-a) to (1-n). In order to deepen the LUMO, it is preferred that R 2 , R 5 and R 10 At least one of them is a group represented by any of formulae (1-a) to (1-n).

[0168] More specific embodiments of the groups represented by formula (1-a) to (1-n) include the following groups: In the formula, * represents a bonding position, Me represents a methyl group, and tBu represents a tert-butyl group.

[0169]

[0170]

[0171]

[0172] In formula (1), R 1 ~R 11 There is no particular limitation on the number of the first substituents, R 1 ~R 11 One or more of them may be the first substituent, or none of them may be substituted (i.e., hydrogen atoms). 1 ~R 11 The total number of carbon atoms of the substituents in is preferably 36 or less. 1 ~R 11 When two or more of the rings a, b, and c are first substituents, the substituent types of the first substituents, the presence or absence of the second substituents, or the type of the substituents may be the same or different. In addition, when two or more of the a ring, b ring, and c ring have first substituents, the number of substitutions, the position of substitutions, and the type of the first substituents, and the presence or absence of the second substituents in the first substituents may be the same or different. 1 ~R 11 When two or more first substituents are introduced into the ring, it is preferred to select the substitution positions in such a way that the mutual steric hindrance becomes small from the viewpoint of easy synthesis. Specifically, it is preferred that: the first substituent is introduced into different rings; or, when the first substituent is introduced into the same ring, the first substituent is introduced into the position that is meta to each other and the position that is para to each other. On the other hand, when the first substituent is introduced into the position that is ortho to each other, it is preferred to select a group with small steric hindrance as the first substituent and the second substituent. As the group with small steric hindrance, a straight-chain alkyl group, a straight-chain alkoxy group, a fluorine group, a cyano group, etc. can be listed.

[0173] In addition, when synthesizing the compound represented by formula (1) by a synthetic method in which boron is introduced last, it is preferred to introduce the substituent in a manner that is linearly symmetrical with respect to the a-ring-B bond from the viewpoint of ease of synthesis. On the other hand, from the viewpoint of reducing crystallinity and aggregation, it is preferred to introduce the substituent in a manner that is asymmetrical with respect to the a-ring-B bond.

[0174] In the above formula (1), R 1 ~R 11The adjacent groups in the a ring are optionally bonded to each other and form an aromatic ring or a heteroaromatic ring together with the a ring, b ring or c ring. 3 R with c ring 4 , c-ring R 7 R with b ring 8 , R of b ring 11 R with a ring 1 etc. do not meet the "adjacent groups" mentioned here, and they will not bond to form a cyclic structure. That is, "adjacent groups" refer to groups present on the same ring and are adjacent to each other. In the ring formed by the above-mentioned adjacent groups bonding to each other and ring a, ring b or ring c, at least one hydrogen is optionally replaced by an aryl, heteroaryl, diarylamino, diheteroarylamino, arylheteroarylamino, alkyl, cycloalkyl, alkoxy or aryloxy group. In the following description, the substituent that replaces the hydrogen of the formed ring is referred to as the "first substituent". In addition, at least one hydrogen in the first substituent is optionally replaced by an aryl, heteroaryl, alkyl or cycloalkyl group. In the following description, the substituent that replaces the hydrogen of the first substituent is referred to as the "second substituent". For the description, preferred range and specific example of the first substituent and the second substituent, refer to R 1 ~R 11 The description, preferred ranges and specific examples of the first substituent and the second substituent.

[0175] Specifically, the compound represented by formula (1) may be a compound obtained by changing the ring structure as shown in the following formulas (1-L1) and (1-L2) by bonding the substituents in the a ring, b ring and c ring. The a' ring, b' ring and c' ring in each formula correspond to the above-mentioned "formed ring" (R 1 ~R 11 The adjacent groups are bonded to each other and together with the a ring, b ring or c ring form an aromatic ring or heteroaromatic ring). It should be noted that R in formula (1-L1) and formula (1-L2) 1 ~R 11 The definitions of ring a, ring b and ring c are the same as those of R in formula (1). 1 ~R 11 , a ring, b ring and c ring have the same definitions.

[0176]

[0177] It should be noted that, although not shown in the formula, the compound represented by formula (1) may be a compound in which the a ring, b ring and c ring are all replaced by a' ring, b' ring and c' ring.

[0178] The compounds represented by the above formula (1-L1) and formula (1-L2) are compounds having at least one of a' ring (condensed ring a'), b' ring (condensed ring b') and c' ring (condensed ring c') formed by condensing a benzene ring, an indole ring, a pyrrole ring, a benzofuran ring or a benzothiophene ring with a benzene ring in at least one of the a ring, the b ring and the c ring. Specific examples of the condensed ring a', the condensed ring b' and the condensed ring c' include a naphthalene ring, a carbazole ring, an indole ring, a dibenzofuran ring or a dibenzothiophene ring.

[0179] In addition, examples of the a' ring, b' ring and c' ring include the following aromatic rings and heteroaromatic rings.

[0180] That is, as the "aromatic ring" that can be used for the a' ring, b' ring, and c' ring, for example, there can be listed aromatic rings having 9 to 30 carbon atoms, preferably aromatic rings having 9 to 24 carbon atoms, more preferably aromatic rings having 9 to 20 carbon atoms, further preferably aromatic rings having 9 to 16 carbon atoms, particularly preferably aromatic rings having 9 to 12 carbon atoms, and most preferably aromatic rings having 9 to 10 carbon atoms. It should be noted that the lower limit of the number of carbon atoms of the "aromatic ring" here, "9", corresponds to the total number of carbon atoms when a five-membered ring is condensed on the benzene ring (carbon number 6) constituting the a ring (b ring or c ring).

[0181] Specific examples of the "aromatic ring" include a naphthalene ring as a fused bicyclic ring system; an acenaphthylene ring, a fluorene ring, a phenalene ring, and a phenanthrene ring as a fused tricyclic ring system; a benzophenanthrene ring, a pyrene ring, and a tetracene ring as a fused tetracyclic ring system; and a perylene ring and a pentacene ring as a fused pentacyclic ring system.

[0182] As the "heteroaromatic ring" that can be used for the a' ring, b' ring, and c' ring, for example, a heteroaromatic ring having 6 to 30 carbon atoms can be listed, preferably a heteroaromatic ring having 6 to 25 carbon atoms, more preferably a heteroaromatic ring having 6 to 20 carbon atoms, further preferably a heteroaromatic ring having 6 to 15 carbon atoms, and particularly preferably a heteroaromatic ring having 6 to 10 carbon atoms. The heteroatoms in the "heteroaromatic ring" are not particularly limited, and examples thereof include oxygen, sulfur, and nitrogen. The "aromatic heterocyclic ring" constituting the a' ring, b' ring, and c' ring is preferably a heterocyclic ring containing 1 to 5 heteroatoms. It should be noted that the lower limit of the number of carbon atoms in the "heteroaromatic ring" here, "6", corresponds to the total number of carbon atoms of 6 when a five-membered ring having 3 heteroatoms is fused to the benzene ring (carbon number 6) constituting the a ring (b ring or c ring).

[0183] Specific examples of the "heteroaromatic ring" include an indole ring, an isoindole ring, a 1H-indazole ring, a benzimidazole ring, a benzoxazole ring, a benzothiazole ring, a 1H-benzotriazole ring, a quinoline ring, an isoquinoline ring, a cinnoline ring, a quinazoline ring, a quinoxaline ring, a phthalazine ring, a naphthyridine ring, a purine ring, a pteridine ring, a carbazole ring, an acridine ring, a phenoxathiol ring, a phenoxazine ring, a phenothiazine ring, a phenazine ring, an indolizine ring, a benzofuran ring, an isobenzofuran ring, a dibenzofuran ring, a benzothiophene ring, a dibenzothiophene ring, and a thianthrene ring.

[0184] Preferred examples (first to fourth aspects) of the host compound used as the first component in the present invention are listed below.

[0185] The host compound of the first embodiment is a compound represented by formula (1), wherein R 1 ~R 11 Each independently represents hydrogen, or aryl, heteroaryl, diarylamino, diheteroarylamino, arylheteroarylamino, alkyl, cycloalkyl or alkoxy (first substituent). At least one hydrogen in the aryl, heteroaryl, diarylamino, diheteroarylamino and arylheteroarylamino as the first substituent is optionally substituted by aryl, heteroaryl, alkyl or cycloalkyl (second substituent). In other words, the host compound of the first embodiment is a compound in which the first substituent is a substituent other than aryloxy (e.g., a group represented by the above formula (1-h)).

[0186] The host compound of the second embodiment is a compound represented by formula (1), and R 4 ~R 11 At least one of them is a heteroaryl group as a first substituent. At least one hydrogen atom in the heteroaryl group as a first substituent may be substituted with an aryl group, a heteroaryl group, an alkyl group or a cycloalkyl group as a second substituent.

[0187] Specific examples of the host compound of the second embodiment include the compound (BO2-0431) and the compound (BO2-0520S) described later.

[0188] In the host compound of the second embodiment, R 4 ~R 11 At least one of them is preferably a group represented by any of the above-mentioned formulas (1-a), (1-b), (1-c), (1-d), (1-l), (1-m) and (1-n), and more preferably a group represented by any of formulas (1-a) and (1-d).

[0189] The host compound of the third embodiment is a compound represented by formula (1), and R 1 ~R 3At least one of them is an aryl group or a dibenzofuranyl group as a first substituent. At least one hydrogen atom in the aryl group and the dibenzofuranyl group as a first substituent may be substituted with an aryl group, a heteroaryl group, an alkyl group or a cycloalkyl group as a second substituent.

[0190] Specific examples of the host compound of the third formula include the compound (BO2-0264 / 0511S) and the compound (BO2-0231) described below.

[0191] In the host compound of the third embodiment, R 1 ~R 3 At least one of them is preferably a group represented by any of the above formulas (1-d), (1-f), (1-i), (1-j) and (1-k), and more preferably a group represented by any of the above formulas (1-d) and (1-i).

[0192] The host compound of the fourth embodiment is a compound represented by formula (1), and R 1 ~R 3 is a heteroaryl group as the first substituent, and R 4 ~R 11 At least one of them is an aryl group as a first substituent. At least one hydrogen in the heteroaryl group as the first substituent is optionally substituted by an aryl group, a heteroaryl group, an alkyl group or a cycloalkyl group as a second substituent, and at least one hydrogen in the aryl group as the first substituent is optionally substituted by an aryl group, a heteroaryl group, an alkyl group or a cycloalkyl group as a second substituent.

[0193] Specific examples of the host compound of the fourth embodiment include the compound (BO2-0220 / 0510S) and the compound (BO2-0220 / 0511S) described later.

[0194] In the host compound of the fourth embodiment, R 1 ~R 3 At least one of them is preferably a group represented by any of the above formulas (1-a), (1-b), (1-c), (1-d), (1-l), (1-m) and (1-n), R 4 ~R 11 At least one of them is preferably a group represented by any of the above formula (1-f), formula (1-i), formula (1-j) and formula (1-k).

[0195] It should be noted that at least one hydrogen in the compound represented by formula (1) may be optionally substituted by the substituents listed above, or may be optionally substituted by cyano, halogen or deuterium. Halogen is fluorine, chlorine, bromine or iodine, preferably fluorine, chlorine or bromine, more preferably fluorine.

[0196] The compound represented by formula (1) used as the main compound is preferably a compound represented by any of the following formulae. It should be noted that in each formula, any hydrogen may be substituted by an alkyl group having 1 to 4 carbon atoms (e.g., a methyl group or a tert-butyl group). In the present invention, the compound represented by formula (1) that can be used as the main compound is not subject to the restrictive interpretation of these specific examples. In the following formulae, Me represents a methyl group, and t-Bu represents a tert-butyl group.

[0197]

[0198]

[0199]

[0200]

[0201]

[0202]

[0203]

[0204]

[0205]

[0206]

[0207]

[0208]

[0209]

[0210]

[0211]

[0212]

[0213]

[0214]

[0215]

[0216]

[0217]

[0218]

[0219]

[0220]

[0221]

[0222] Method for producing a compound represented by formula (1)

[0223] Regarding the compound shown in formula (1), first, an intermediate is manufactured by bonding a to c rings using a bonding group (-O-), and then, a to c rings are bonded by using a bonding group (a group containing B), thereby being able to manufacture a final product (second reaction). In the first reaction, conventional etherification reactions such as nucleophilic substitution reactions and Ullmann reactions can be used. In addition, in the second reaction, a Tandem Bora-Friedel-Crafts reaction (continuous aromatic electrophilic substitution reaction, the same below) can be used. The details of the first reaction and the second reaction can be referred to the description recorded in the International Publication No. 2015 / 102118.

[0224] The second reaction is a reaction of introducing B (boron) that bonds the a ring, b ring, and c ring as shown in the following route (1). First, the hydrogen atom between two Os is ortho-metallated using n-butyllithium, sec-butyllithium, or tert-butyllithium. Next, after metal exchange of lithium-boron is performed by adding boron trichloride, boron tribromide, etc., a Brønsted base such as N,N-diisopropylethylamine is added to cause a Tandem Bora-Friedel-Crafts reaction to obtain the target product. In the second reaction, a Lewis acid such as aluminum trichloride may be added to promote the reaction.

[0225] Route (1)

[0226]

[0227] In the above route, lithium is introduced into the desired position by ortho-metallation. However, lithium can also be introduced into the desired position by introducing a bromine atom or the like into the position where lithium is to be introduced, or by halogen-metal exchange as in the following route (2).

[0228] Route (2)

[0229]

[0230] In order to obtain a compound substituted with halogen or deuterium, these groups may be introduced into the intermediate in advance, or may be introduced after the second reaction.

[0231] By appropriately selecting the above-mentioned synthesis method and appropriately selecting the raw materials to be used, a compound represented by formula (1) having a substituent at a desired position can be synthesized.

[0232] 1-1-2. Compound represented by formula (ii)

[0233] Furthermore, as a host compound having a boron atom and an oxygen atom in a molecule, a compound represented by the following formula (ii) can also be used.

[0234]

[0235] In formula (ii), ring A, ring B and ring C are each independently an aromatic ring or a heteroaromatic ring, and at least one hydrogen atom in these rings is optionally substituted. For the description, preferred range and specific examples of the substituents that may optionally replace the hydrogen atoms in ring A, ring B and ring C, refer to R in formula (1). 1 ~R 11 Description, preferred range and specific examples of the substituents in .

[0236] Y 1 For B, X 1 , X 2 and X 3 Each independently is >O, >NR, >CR2 or >S, X 1 ~X 3 At least two of them are >0. R of NR and R of >CR2 are optionally substituted aryl, optionally substituted heteroaryl or alkyl, and R of >NR is optionally bonded to at least one of the A ring, the B ring and the C ring via a linking group or a single bond.

[0237] At least one hydrogen atom in the compound or structure represented by formula (ii) may be substituted with cyano, halogen or deuterium in addition to being substituted with the above-mentioned substituents.

[0238] The compound represented by formula (ii) is preferably a compound represented by the following formula (2).

[0239]

[0240] In formula (2), R 1 ~R 6 , R 9 ~R 11Each is independently hydrogen, aryl, heteroaryl, diarylamino, diheteroarylamino, arylheteroarylamino, alkyl, cycloalkyl, alkoxy or aryloxy. Among these groups, except for hydrogen, it is a substituent that replaces the hydrogen of the benzene ring corresponding to the a ring to the c ring, which corresponds to the above-mentioned "first substituent". At least one hydrogen of the first substituent is optionally replaced by an aryl, heteroaryl or alkyl group as a second substituent. For the description, preferred range and specific examples of the first substituent and the second substituent, refer to R of formula (1) 1 ~R 6 , R 9 ~R 11 The corresponding description of the first substituent and the second substituent.

[0241] In the above formula (2), R 1 ~R 6 , R 9 ~R 11 The adjacent groups are optionally bonded to each other and form an aromatic ring or heteroaromatic ring together with the a ring, b ring or c ring. For the description, preferred range and specific examples of the adjacent groups, the aromatic ring or heteroaromatic ring formed by the adjacent groups bonding to each other and the a ring, b ring or c ring, and the substituents that optionally replace the hydrogen of these rings, refer to the corresponding description in formula (1).

[0242] X 1 ~X 3 Each independently is >O, >NR, >S or >CR2, X 1 ~X 3 At least 2 of them are >0. 1 ~X 3 The number of groups >O in the formula (X) may be 2 or 3, preferably 3. That is, preferably X 1 ~X 3 All are >O.

[0243] R of >NR and R of >CR2 are aryl, heteroaryl or alkyl, and at least one hydrogen in these groups is optionally substituted by aryl, heteroaryl or alkyl. For the preferred range and specific examples of aryl, heteroaryl and alkyl in R, refer to R of formula (1): 1 ~R 11 When two or more Rs exist in the molecule of the compound represented by formula (2), the plurality of Rs may be the same or different from each other.

[0244] The compound represented by formula (2) preferably contains at least one structure selected from the above-mentioned partial structure group A in the molecule, and preferably R 1 ~R 11At least one of them is a group represented by any of the above formulae (1-a) to (1-n). For the description, preferred range, and specific examples of the partial structural group A and formulae (1-a) to (1-n), reference can be made to the description, preferred range, and specific examples of the partial structural group A and formulae (1-a) to (1-n) in formula (1).

[0245] It should be noted that at least one hydrogen in the compound represented by formula (2) may be optionally substituted by the substituents listed above, or may be optionally substituted by cyano, halogen or deuterium. Halogen is fluorine, chlorine, bromine or iodine, preferably fluorine, chlorine or bromine, more preferably fluorine.

[0246] The specific structure of the above formula (2) is shown below.

[0247]

[0248] 1-1-3. Compound represented by formula (iii)

[0249] Furthermore, as a host compound having a boron atom and an oxygen atom in a molecule, a compound represented by the following formula (iii) can also be used.

[0250]

[0251] In formula (iii), ring A, ring B, ring C and ring D are each independently an aromatic ring or a heteroaromatic ring, and at least one hydrogen atom in these rings is optionally substituted. For the description, preferred range and specific examples of the substituents that may optionally replace the hydrogen atoms in ring A, ring B, ring C and ring D, refer to R in formula (1). 1 ~R 11 Related descriptions, preferred ranges and specific examples of the substituents in .

[0252] R 1 and R 2 Each is independently hydrogen, an alkyl group having 1 to 6 carbon atoms, an aryl group having 6 to 12 carbon atoms, a heteroaryl group having 2 to 15 carbon atoms, a diarylamino group (wherein the aryl group is an aryl group having 6 to 12 carbon atoms), a diheteroarylamino group (wherein the heteroaryl group is a heteroaryl group having 2 to 15 carbon atoms), or an arylheteroarylamino group (wherein the aryl group is an aryl group having 6 to 12 carbon atoms, and the heteroaryl group is a heteroaryl group having 2 to 15 carbon atoms).

[0253] At least one hydrogen atom in the compound represented by formula (iii) may be substituted with a cyano group, a halogen group or a deuterium group in addition to being substituted with the above-mentioned substituents.

[0254] The compound represented by formula (iii) is preferably a compound represented by the following formula (3).

[0255]

[0256] In formula (3), R 1 ~R 14 Each is independently hydrogen, aryl, heteroaryl, diarylamino, diheteroarylamino, arylheteroarylamino, alkyl, cycloalkyl, alkoxy, aryloxy, heteroaryloxy, arylthio, heteroarylthio or alkyl-substituted silyl. Among these groups, except for hydrogen, it is a substituent that replaces the hydrogen of the benzene ring corresponding to the a ring to the d ring, which corresponds to the above-mentioned "first substituent". At least one hydrogen in the first substituent is optionally replaced by an aryl, heteroaryl or alkyl as a second substituent.

[0257] In formula (3), R 5 ~R 7 and R 10 ~R 12 The adjacent groups are optionally bonded to each other and form an aromatic ring or heteroaromatic ring together with the b ring or the d ring. For the description of the adjacent groups, the description and preferred range and specific examples of the aromatic ring or heteroaromatic ring formed by the adjacent groups bonding to each other and the b ring or the d ring, refer to the corresponding description in formula (1).

[0258] At least one hydrogen in the ring formed by the adjacent groups mutually bonded to each other and formed together with the b ring or the d ring may be substituted by an aryl, heteroaryl, diarylamino, diheteroarylamino, arylheteroarylamino, alkyl, cycloalkyl, alkoxy, aryloxy, heteroaryloxy, arylthio, heteroarylthio or alkyl-substituted silyl. These groups are substituents that replace the hydrogen of the formed ring, which are equivalent to the above-mentioned "first substituent". In addition, at least one hydrogen in the first substituent may be substituted by an aryl, heteroaryl or alkyl as a second substituent.

[0259] For the description, preferred range and specific examples of the aryl group as the first substituent, and the aryl group in the diarylamino group, the arylheteroarylamino group, the aryloxy group and the arylthio group, refer to R in the formula (1). 1 ~R 11 The description, preferred range and specific examples of the aryl group as the first substituent in the formula (1) can be referred to for the description, preferred range and specific examples of the aryl group as the second substituent. 1 ~R 11 For the description, preferred range and specific examples of the aryl group as the second substituent in the formula (1), reference may be made to the description, preferred range and specific examples of the heteroaryl group as the first substituent, and the heteroaryl groups in the diheteroarylamino, arylheteroarylamino, heteroaryloxy and heteroarylthio groups. 1 ~R 11 The description, preferred range and specific examples of the heteroaryl group as the first substituent in the formula (1) can be referred to for the description, preferred range and specific examples of the heteroaryl group as the second substituent.1 ~R 11 The description, preferred range and specific examples of the heteroaryl group as the second substituent in the formula (1) can be referred to for the description, preferred range and specific examples of the alkyl group and cycloalkyl group as the first substituent, and the alkyl group in the alkyl-substituted silyl group. 1 ~R 11 The description, preferred range and specific examples of the alkyl group and the cycloalkyl group as the first substituent, and the description, preferred range and specific examples of the alkyl group as the second substituent can be referred to R in formula (1). 1 ~R 11 For the description, preferred range and specific examples of the alkyl group as the second substituent, see R in formula (1). 1 ~R 11 Description, preferred range and specific examples of the alkoxy group as the first substituent.

[0260] The compound represented by formula (3) preferably contains at least one structure selected from the above-mentioned partial structure group A in the molecule, and preferably R 1 ~R 14 At least one of them is a group represented by any of the above formulae (1-a) to (1-n). For the description, preferred range, and specific examples of the partial structural group A and formulae (1-a) to (1-n), reference can be made to the description, preferred range, and specific examples of the partial structural group A and formulae (1-a) to (1-n) in formula (1).

[0261] It should be noted that at least one hydrogen in the compound represented by formula (3) may be optionally substituted by the substituents listed above, or may be optionally substituted by cyano, halogen or deuterium. Halogen is fluorine, chlorine, bromine or iodine, preferably fluorine, chlorine or bromine, more preferably fluorine.

[0262] Specific examples of the compound represented by formula (3) are shown below. In the following formula, Me represents a methyl group, t Bu represents tert-butyl, and Ph represents phenyl.

[0263]

[0264]

[0265]

[0266]

[0267]

[0268]

[0269]

[0270] The host compound used as the first component is also preferably a compound having a structure represented by the following formula (1-1), (2-1), (2-2) or (3-1).

[0271]

[0272] At least one hydrogen of the structure represented by formula (1-1), (2-1), (2-2) or (3-1) is independently optionally replaced by an aryl group, a heteroaryl group, a diarylamino group, a diheteroarylamino group, an arylheteroarylamino group, an alkyl group, a cycloalkyl group, an alkoxy group or an aryloxy group. Among these groups, except for hydrogen, there are substituents that replace the hydrogen in each structure, which are equivalent to the above-mentioned "first substituent". At least one hydrogen of these first substituents is optionally replaced by an aryl group, a heteroaryl group or an alkyl group as a second substituent. For the description, preferred range and specific examples of the first substituent and the second substituent, reference can be made to R of formula (1). 1 ~R 11 The corresponding description of the first substituent and the second substituent.

[0273] 1-2. Thermally activated delayed phosphor (auxiliary dopant)

[0274] In the present invention, a thermally activated delayed phosphor (TADF compound) is used as the second component of the light-emitting layer.

[0275] The thermally activated delayed phosphor is preferably a multiple resonance effect (MRE) type TADF compound designed in such a way that efficient reverse intersystem crossing occurs by utilizing the multiple resonance effect of boron (electron donating) and nitrogen (electron withdrawing) to localize the HOMO to three carbons on a benzene ring containing six carbons and localize the LUMO to the remaining three carbons. Furthermore, it is more preferably an MRE type TADF compound in which the planarity is reduced by introducing substituents.

[0276] Examples of the MRE-type TADF compound include compounds having a structure represented by the following formula (AD11), (AD12), (AD13), (AD21) or (AD22).

[0277]

[0278] In formulas (AD11), (AD12) and (AD13), R 7 and R 8 is an alkyl group having 1 to 6 carbon atoms. 7 The alkyl group having 1 to 6 carbon atoms may be linear, branched or cyclic.

[0279] At least one hydrogen in the structure represented by formula (AD11), (AD12), (AD13), (AD21) or (AD22) is independently optionally substituted by an aryl group, a heteroaryl group, a diarylamino group, a diheteroarylamino group, an arylheteroarylamino group, an alkyl group, a cycloalkyl group, an alkoxy group or an aryloxy group, which are optionally further substituted by an aryl group, a heteroaryl group or an alkyl group. For the preferred range and specific examples of the aryl group, the heteroaryl group, the diarylamino group, the diheteroarylamino group, the arylheteroarylamino group, the alkyl group, the cycloalkyl group, the alkoxy group or the aryloxy group, refer to R in formula (1). 1 ~R 11 The corresponding records in .

[0280] Hereinafter, for the formulas (AD11), (AD12) and (AD13) used as the second component of the light-emitting layer, a short delayed fluorescence lifetime is achieved in the compound by appropriately combining (i) introducing an element that adjusts the multiple resonance effect at an appropriate position and (ii) introducing a substituent at an appropriate position in order to deform the molecule and reduce the planarity. In particular, for the aforementioned (ii), specifically, by introducing Z 1 or R 8 The introduction of specific substituents deforms the molecule, and the singlet and triplet orbitals also deform accordingly. The deformation of the orbitals leads to greater spin-orbit interactions. Specifically, compounds of the following structural formulas can be cited. In the following formula, Me represents a methyl group, and t-Bu represents a tert-butyl group.

[0281]

[0282]

[0283]

[0284]

[0285]

[0286]

[0287]

[0288]

[0289]

[0290]

[0291]

[0292]

[0293]

[0294]

[0295]

[0296]

[0297]

[0298]

[0299]

[0300] Hereinafter, for formulas (AD21) and (AD22) used as the second component of the light-emitting layer, an element that adjusts the multiple resonance effect is introduced at an appropriate position by (i), thereby achieving a short delayed fluorescence lifetime in the compound. With regard to the aforementioned (i), the polycyclic aromatic compounds represented by the general formulas (AD21) and (AD22) of the present invention are affected by the multiple resonance effect of the molecule by the appropriate introduction of >O and >NR. Specifically, the compounds of the following structural formulas can be cited. In the following formula, Me represents a methyl group and t-Bu represents a tert-butyl group.

[0301]

[0302]

[0303] At least one hydrogen atom in the compounds represented by the above formulae may be substituted by an alkyl group having 1 to 6 carbon atoms, a cyano group, a halogen group or a deuterium group, wherein R 100 Each is independently an aryl group having 6 to 10 carbon atoms, a carbazolyl group, a diarylamino group (wherein the aryl group is an aryl group having 6 to 10 carbon atoms), a diheteroarylamino group (wherein the heteroaryl group is a heteroaryl group having 2 to 15 carbon atoms), an arylheteroarylamino group (wherein the aryl group is an aryl group having 6 to 12 carbon atoms and the heteroaryl group is a heteroaryl group having 2 to 15 carbon atoms), an alkyl group having 1 to 6 carbon atoms, a cycloalkyl group having 3 to 10 carbon atoms or an aryloxy group having 6 to 10 carbon atoms, the aforementioned aryl group may be substituted with an alkyl group having 1 to 6 carbon atoms, and the aforementioned carbazolyl group may be substituted with an aryl group having 6 to 10 carbon atoms or an alkyl group having 1 to 6 carbon atoms.

[0304] Available through R 100The emission wavelength is adjusted by adjusting the steric hindrance, electron donating and electron withdrawing properties of the structure. It is preferably a group shown in the following formula, and more preferably a methyl group, a tert-butyl group, a phenyl group, an o-tolyl group, a p-tolyl group, a 2,4-xyl group, a 2,5-xyl group, a 2,6-xyl group, a 2,4,6-trimethylphenyl group, a diphenylamino group, a di-p-tolylamino group, a bis(p-(tert-butyl)phenyl)amino group, a carbazolyl group, a 3,6-dimethylcarbazolyl group, a 3,6-di-tert-butylcarbazolyl group and a phenoxy group. Further preferably a methyl group, a tert-butyl group, a phenyl group, an o-tolyl group, a 2,6-xyl group, a 2,4,6-trimethylphenyl group, a diphenylamino group, a di-p-tolylamino group, a bis(p-(tert-butyl)phenyl)amino group, a carbazolyl group, a 3,6-dimethylcarbazolyl group and a 3,6-di-tert-butylcarbazolyl group. From the viewpoint of ease of synthesis, a group with large steric hindrance is preferred for selective synthesis, and specifically, tert-butyl, o-tolyl, p-tolyl, 2,4-xylyl, 2,5-xylyl, 2,6-xylyl, 2,4,6-trimethylphenyl, di-p-tolylamino, bis(p-(tert-butyl)phenyl)amino, 3,6-dimethylcarbazolyl and 3,6-di-tert-butylcarbazolyl are preferred.

[0305] The thermally activated delayed phosphor (TADF compound) used in the present invention is also preferably a donor-acceptor type TADF compound (DA-type TADF compound) designed in a manner that localizes the HOMO (Highest Occupied Molecular Orbital) and LUMO (Lowest Unoccupied Molecular Orbital) in the molecule using an electron-donating substituent called a donor and an electron-accepting substituent called an acceptor, thereby causing efficient reverse intersystem crossing.

[0306] Here, in this specification, "electron donating substituent" (donor) refers to: a substituent and partial structure localized in the HOMO orbital in the TADF compound molecule, and "electron accepting substituent" (acceptor) refers to: a substituent and partial structure localized in the LUMO orbital in the TADF compound molecule.

[0307] Generally speaking, TADF compounds using donors and acceptors have large spin-orbit coupling (SOC: SpinOrbit Coupling) due to their structure, small exchange interaction between HOMO and LUMO, and small ΔE(ST), so they can obtain very fast reverse intersystem crossing speed. On the other hand, TADF compounds using donors and acceptors have large structural relaxation in the excited state (in a certain molecule, the stable structures in the ground state and the excited state are different, so if a transition from the ground state to the excited state occurs due to external stimulation, the structure then changes to the stable structure in the excited state), giving a wide emission spectrum, so if used as a light-emitting material, there is a possibility that the color purity will be reduced.

[0308] As the thermally activated delayed fluorescent substance (TADF compound) of the present invention, for example, a DA-type TADF compound in which a donor and an acceptor are bonded via a spacer group can be used. As the DA-type TADF compound, a compound represented by the following formula (AD31) can be cited. In formula (AD31), the structure enclosed in brackets corresponds to the donor, the group represented by Q corresponds to the acceptor, and the phenylene group connecting the structure enclosed in brackets to Q corresponds to the spacer group.

[0309]

[0310] In formula (AD31), M is independently at least one of a single bond, -O-, >N-Ar and >CAr2, and Ar is an aryl group. For the preferred range and specific examples of the aryl group, reference can be made to R in formula (1). 1 ~R 11 The preferred range and specific examples of the aryl group in the formula (A) are shown in Table 1. The bond of N is bonded to any substitutable position of the phenylene group.

[0311] Q is a group represented by any of the following formulae (Q1) to (Q26).

[0312] n is an integer of 1-5, preferably an integer of 2-5, and more preferably an integer of 4-5.

[0313] The hydrogen atoms in the formula (AD31) are each independently optionally substituted by an aryl group having 6 to 18 carbon atoms, a heteroaryl group having 6 to 18 carbon atoms, an alkyl group having 1 to 6 carbon atoms, or a cycloalkyl group having 3 to 12 carbon atoms. For the preferred ranges and specific examples of the aryl group, heteroaryl group, alkyl group, and cycloalkyl group, refer to R in the formula (1). 1 ~R 11 The corresponding records in .

[0314] Furthermore, at least one hydrogen atom in the compound represented by formula (AD31) may be substituted with a halogen atom or a deuterium atom in addition to being substituted with the above-mentioned substituents.

[0315]

[0316] In formulas (Q1) to (Q26), the wavy lines indicate bonding positions.

[0317] Furthermore, examples of the DA-type TADF compound used as the second component include compounds having a structure represented by any of the following formulas (AD3101) to (AD3118).

[0318]

[0319] At least one hydrogen in the structures represented by formula (AD3101) to (AD3118) is independently optionally substituted by an aryl group having 6 to 18 carbon atoms, a heteroaryl group having 6 to 18 carbon atoms, an alkyl group having 1 to 6 carbon atoms, or a cycloalkyl group having 3 to 12 carbon atoms. For the preferred ranges and specific examples of the aryl group, heteroaryl group, alkyl group, and cycloalkyl group, refer to R in formula (1). 1 ~R 11 The corresponding records in .

[0320] Furthermore, as the donor and acceptor structures used in the thermally activated delayed phosphor of the present invention, for example, the structures described in Chemistry of Materials, 2017, 29, 1946-1963 can be used. As the donor structure, carbazole, dimethyl carbazole, di-tert-butyl carbazole, dimethoxy carbazole, tetramethyl carbazole, benzofluorocarbazole, benzothiophene carbazole, phenyldihydroindole carbazole, phenyl bicarbazole, bicarbazole, tertiary carbazole, diphenylcarbazolylamine, tetraphenylcarbazolyldiamine, phenoxazine, dihydrophenazine, phenothiazine, dimethyldihydroacridine, diphenylamine, bis(tert-butylphenyl)amine, (diphenylamino)phenyl)diphenylphenylenediamine, dimethyltetraphenyldihydroacridinediamine, tetramethyldihydroindenoacridine and diphenyldihydrodibenzoaziridine heterocyclohexane can be listed. Examples of the acceptor structure include sulfonyl diphenyl, benzophenone, phenylenebis(phenyl ketone), benzonitrile, isonicotinonitrile, phthalonitrile, isophthalonitrile, terephthalonitrile, benzene trimonitrile, triazole, oxazole, thiadiazole, benzothiazole, benzobisthiazole, benzoxazole, benzobisoxazole, quinoline, benzimidazole, dibenzoquinoxaline, heptazaphenalene, thioxanthone dioxide, dimethylanthrone, anthracene dione, cycloheptyldipyridine, fluorene dicarbonitrile, triphenyltriazine, pyrazine dicarbonitrile, pyrimidine, phenylpyrimidine, methylpyrimidine, pyridine dicarbonitrile, dibenzoquinoxaline dicarbonitrile, bis(phenylsulfonyl)benzene, dimethylthioxanthene dioxide, thianthrene tetraoxide, and tri(dimethylphenyl)borane. In particular, the compound having thermally activated delayed fluorescence of the present invention is preferably a compound having at least one selected from carbazole, phenoxazine, acridine, triazine, pyrimidine, pyrazine, thioxanthene, benzonitrile, phthalonitrile, isophthalonitrile, diphenyl sulfone, triazole, oxadiazole, thiadiazole and benzophenone as a partial structure.

[0321] The following are examples of compounds that can be used as the second component (thermally activated delayed phosphor): In the following formula, Me represents a methyl group, t-Bu represents a tert-butyl group, Ph represents a phenyl group, and a wavy line represents a bonding position.

[0322]

[0323]

[0324]

[0325]

[0326]

[0327]

[0328]

[0329]

[0330]

[0331]

[0332]

[0333]

[0334]

[0335]

[0336]

[0337]

[0338]

[0339]

[0340] Furthermore, as the thermally activated delayed phosphor, a compound represented by any of the following formulas (AD1), (AD2) and (AD3) may be used.

[0341]

[0342] In formulas (AD1) to (AD3),

[0343] M is each independently a single bond, -O-, >N-Ar or >CAr2, and is preferably a single bond, -O- or >N-Ar from the viewpoint that the HOMO of the formed partial structure is deep and the excited singlet energy level and the excited triplet energy level are high. J is a spacer structure that separates the donor partial structure from the acceptor partial structure, and is each independently an arylene group having 6 to 18 carbon atoms, and is preferably an arylene group having 6 to 12 carbon atoms from the viewpoint that the conjugation emanating from the donor partial structure and the acceptor partial structure is large. More specifically, phenylene, methylphenylene and dimethylphenylene can be listed. Q is each independently =C(-H)- or =N-, and is preferably =N- from the viewpoint that the LUMO of the formed partial structure is shallow and the excited singlet energy level and the excited triplet energy level are high. Ar is independently hydrogen, an aryl group having 6 to 24 carbon atoms, a heteroaryl group having 2 to 24 carbon atoms, an alkyl group having 1 to 12 carbon atoms, and a cycloalkyl group having 3 to 18 carbon atoms. From the viewpoint of a deep HOMO of the formed partial structure and a high excited singlet energy level and an excited triplet energy level, preferably hydrogen, an aryl group having 6 to 12 carbon atoms, a heteroaryl group having 2 to 14 carbon atoms, an alkyl group having 1 to 4 carbon atoms, and a cycloalkyl group having 6 to 10 carbon atoms, more preferably hydrogen, phenyl, tolyl, xylyl, mesityl, biphenyl, pyridyl, bipyridyl, triazine, carbazolyl, dimethylcarbazolyl, di-tert-butylcarbazolyl, benzimidazole, and phenylbenzimidazole, and further preferably hydrogen, phenyl, and carbazolyl. m is 1 or 2. n is an integer of 2 to (6-m), and from the viewpoint of steric hindrance, preferably an integer of 4 to (6-m). Furthermore, at least one hydrogen atom in the compounds represented by the above formulae may be substituted by halogen or deuterium.

[0344] The compound used as the second component of the light-emitting layer of the present invention is more specifically preferably 4CzBN, 4CzBN-Ph, 5CzBN, 3Cz2DPhCzBN, 4CzIPN, 2PXZーTAZ, Cz-TRZ3, BDPCC-TPTA, MA-TA, PA-TA, FA-TA, PXZ-TRZ, DMAC-TRZ, BCzT, DCzTrz, DDCzTRz, spiroAC-TRZ, Ac-HPM, Ac-PPM, Ac-MPM, TCzTrz, TmCzTrz and DCzmCzTrz.

[0345] Furthermore, the compound used as the second component of the light-emitting layer of the present invention is preferably a thermally activated delayed phosphor, and the emission spectrum of the compound at least partially overlaps with the absorption peak of the light-emitting dopant.

[0346] The compound used as the second component of the light-emitting layer of the present invention is more preferably a DA-type TADF compound than an MRE-type TADF compound from the viewpoint of a fast reverse intersystem crossing rate from a triplet state to a singlet state.

[0347] 1-3. Phosphor (luminescent dopant)

[0348] In the present invention, a phosphor is used as the third component of the light-emitting layer.

[0349] The third component of the present invention is not particularly limited, and a known compound can be used, and can be selected from various materials according to the desired luminescent color. Specifically, for example, phenanthrene, anthracene, pyrene, tetracene, pentacene, perylene, naphthopyrene, dibenzopyrene, rubrene and fused ring derivatives; benzoxazole derivatives, benzothiazole derivatives, benzimidazole derivatives, benzotriazole derivatives, oxazole derivatives, oxadiazole derivatives, thiazole derivatives, imidazole derivatives, thiadiazole derivatives, triazole derivatives, dihydropyrazole derivatives, stilbene derivatives, thiophene derivatives, tetraphenylbutadiene derivatives, cyclopentadiene derivatives, bis-styrylanthracene derivatives, bis-styrylbenzene derivatives and the like bis-styryl derivatives (Japanese Patent Laid-Open No. 1-245087); bis-styrylarylene derivatives (Japanese Patent Laid-Open No. 2-247278), diazaindacenyl derivatives, furan derivatives, benzofuran derivatives, phenylisobenzofuran, bistrisylisobenzofuran, di(2-methylphenyl)isobenzofuran, di(2-trifluoromethylphenyl)isobenzofuran, isobenzofuran derivatives such as phenylisobenzofuran; dibenzofuran derivatives, 7-dialkylaminocoumarin derivatives, 7-piperidinylcoumarin derivatives Coumarin derivatives such as 7-hydroxycoumarin derivatives, 7-methoxycoumarin derivatives, 7-acetoxycoumarin derivatives, 3-benzothiazolylcoumarin derivatives, 3-benzimidazolylcoumarin derivatives, 3-benzoxazolylcoumarin derivatives; dicyanomethylenepyran derivatives, dicyanomethylenethiopyran derivatives, polymethine derivatives, cyanine derivatives, oxybenzanthracene derivatives, xanthene derivatives, rhodamine derivatives, fluorescein derivatives Biologicals, pyrylium derivatives, quinolone derivatives, acridine derivatives, oxazine derivatives, phenyl ether derivatives, quinacridone derivatives, quinazoline derivatives, pyrrolopyridine derivatives, furanopyridine derivatives, 1,2,5-thiadiazolopyrene derivatives, pyrromethene derivatives, perylene derivatives, pyrrolopyrrole derivatives, squarylium salt derivatives, anthrone derivatives, phenazine derivatives, acridone derivatives, deazotflavin derivatives, fluorene derivatives and benzofluorene derivatives, etc.

[0350] When exemplified by color distribution, blue to blue-green dopant materials include naphthalene, anthracene, phenanthrene, pyrene, triphenylene, perylene, fluorene, indene, Aromatic hydrocarbon compounds or their derivatives; aromatic heterocyclic compounds or their derivatives such as furan, pyrrole, thiophene, silacyclopentadiene, 9-silafluorene, 9,9'-spiro-silafluorene, benzothiophene, benzofuran, indole, dibenzothiophene, dibenzofuran, imidazopyridine, phenanthroline, pyrazine, naphthyridine, quinoxaline, pyrrolopyridine, thioxanthene, etc.; distyrylbenzene derivatives, tetraphenylbutadiene derivatives, stilbene derivatives, aldazine derivatives, coumarin derivatives, imidazole, thiazole, thiadiazole, carbazole, oxazole, oxadiazole, triazole and the like azole derivatives and their metal complexes; and aromatic amine derivatives represented by N,N'-diphenyl-N,N'-di(3-methylphenyl)-4,4'-diphenyl-1,1'-diamine, etc.

[0351] In addition, as green to yellow doping materials, there can be listed coumarin derivatives, phthalimide derivatives, naphthalimide derivatives, perylene derivatives, pyrrolopyrrole derivatives, cyclopentadiene derivatives, acridone derivatives, quinacridone derivatives and tetracene derivatives such as rubrene, and further, as suitable examples, there can be listed compounds obtained by introducing substituents capable of lengthening the wavelength, such as aromatic groups, heteroaryl groups, aromatic vinyl groups, amino groups and cyano groups, into the compounds exemplified as the above-mentioned blue to blue-green doping materials.

[0352] Furthermore, as orange to red doping materials, there can be listed naphthalimide derivatives such as bis(diisopropylphenyl)perylenetetracarboxylic acid imide; perylene derivatives, rare earth complexes such as Eu complexes with acetylacetone or benzoylacetone and phenanthroline as ligands; 4-(dicyanomethylidene)-2-methyl-6-(p-dimethylaminophenylvinyl)-4H-pyran or its analogs, metal phthalocyanine derivatives such as magnesium phthalocyanine and aluminum chlorophthalocyanine; rhodamine compounds, deazotflavin derivatives, coumarin derivatives, etc. Suitable examples include oxazine derivatives, quinacridone derivatives, phenoxazine derivatives, oxazine derivatives, quinazoline derivatives, pyrrolopyridine derivatives, squarylium salt derivatives, violanthrone derivatives, phenazine derivatives, phenoxazinone derivatives and thiadiazopyrene derivatives, and further, as suitable examples, compounds obtained by introducing substituents capable of lengthening the wavelength, such as aryl groups, heteroaryl groups, arylvinyl groups, amino groups and cyano groups, into the above-mentioned compounds exemplified as blue to blue-green and green to yellow doping materials.

[0353] As the third component, a compound described in Chemical Industry, June 2004, page 13, and references cited therein can be appropriately selected and used.

[0354] The amine having a stilbene structure is represented by, for example, the following formula.

[0355]

[0356] In this formula, Ar1 is an m-valent group derived from an aromatic group having 6 to 30 carbon atoms, Ar 2 and Ar 3 are each independently an aryl group having 6 to 30 carbon atoms, Ar 1 ~Ar 3 At least one of them has a stilbene structure, Ar 1 ~Ar 3 It is optionally substituted, and m is an integer of 1-4.

[0357] The amine having a stilbene structure is more preferably diaminostilbene represented by the following formula.

[0358]

[0359] In this formula, Ar 2 and Ar 3 are each independently an aryl group having 6 to 30 carbon atoms, Ar 2 and Ar 3 Optionally substituted.

[0360] Specific examples of the aryl group having 6 to 30 carbon atoms include benzene, naphthalene, acenaphthylene, fluorene, phenanthrenes, anthracene, fluoranthene, triphenylene, pyrene, Tetracene, perylene, stilbene, distyrylbenzene, distyrylbiphenyl, distyrylfluorene, etc.

[0361] Specific examples of the amine having a stilbene structure include N,N,N',N'-tetrakis(4-biphenyl)-4,4'-diaminostilbene, N,N,N',N'-tetrakis(1-naphthyl)-4,4'-diaminostilbene, N,N,N',N'-tetrakis(2-naphthyl)-4,4'-diaminostilbene, N,N'-di(2-naphthyl)-N,N'-diphenyl-4,4'-diaminostilbene, N,N'-di(9-phenanthrenyl)-N, N'-diphenyl-4,4'-diaminostilbene, 4,4'-bis[4"-bis(diphenylamino)phenylvinyl]-biphenyl, 1,4-bis[4'-bis(diphenylamino)phenylvinyl]-benzene, 2,7-bis[4'-bis(diphenylamino)phenylvinyl]-9,9-dimethylfluorene, 4,4'-bis(9-ethyl-3-carbazolevinyl)biphenyl, 4,4'-bis(9-phenyl-3-carbazolevinyl)biphenyl, and the like.

[0362] Furthermore, amines having a stilbene structure described in JP-A-2003-347056 and JP-A-2001-307884 may also be used.

[0363] Examples of the perylene derivatives include 3,10-bis(2,6-dimethylphenyl)perylene, 3,10-bis(2,4,6-trimethylphenyl)perylene, 3,10-diphenylperylene, 3,4-diphenylperylene, 2,5,8,11-tetra-tert-butylperylene, 3,4,9,10-tetraphenylperylene, 3-(1'-pyrenyl)-8,11-di(tert-butyl)perylene, 3-(9'-anthryl)-8,11-di(tert-butyl)perylene, and 3,3'-bis(8,11-di(tert-butyl)perylene).

[0364] Furthermore, perylene derivatives described in JP-A-11-97178, JP-A-2000-133457, JP-A-2000-26324, JP-A-2001-267079, JP-A-2001-267078, JP-A-2001-267076, JP-A-2000-34234, JP-A-2001-267075, and JP-A-2001-217077 may also be used.

[0365] In addition, as for the compound used as the third component of the present invention, compounds containing a boron atom can be listed, for example, borane derivatives, dioxaborinnaphthoanthracene (DOBNA) derivatives and multimers thereof, diazaborinnaphthoanthracene (DABNA) derivatives and multimers thereof, oxazaborinnaphthoanthracene (OABNA) derivatives and multimers thereof, oxaborinnaphthoanthracene (OBNA) derivatives and multimers thereof, azaborinnaphthoanthracene (ABNA) derivatives and multimers thereof, trioxaborinnaphthalene derivatives and multimers thereof, dioxaborinnaphthalene derivatives and multimers thereof, oxadiazaborinnaphthalene derivatives and multimers thereof, and the like can be listed.

[0366] Examples of borane derivatives include 1,8-diphenyl-10-(bis(trismethylphenylboryl))anthracene, 9-phenyl-10-(bis(trismethylphenylboryl))anthracene, 4-(9'-anthracenyl)bis(trismethylphenylboryl)naphthalene, 4-(10'-phenyl-9'-anthracenyl)bis(trismethylphenylboryl)naphthalene, 9-(bis(trismethylphenylboryl))anthracene, 9-(4'-biphenyl)-10-(bis(trismethylphenylboryl))anthracene, and 9-(4'-(N-carbazolyl)phenyl)-10-(bis(trismethylphenylboryl))anthracene.

[0367] In addition, borane derivatives described in International Publication No. 2000 / 40586 and the like can also be used.

[0368] The aromatic amine derivative is represented by, for example, the following formula.

[0369]

[0370] In this formula, Ar 4 is an n-valent group derived from an aromatic group having 6 to 30 carbon atoms, Ar 5 and Ar 6 are each independently an aryl group having 6 to 30 carbon atoms, Ar 4 ~Ar 6 is optionally substituted, and n is an integer of 1-4.

[0371] In particular, Ar is more preferred 4 Derived from anthracene, A divalent group of fluorene, benzofluorene or pyrene, Ar 5 and Ar 6 are each independently an aryl group having 6 to 30 carbon atoms, Ar 4 ~Ar 6 An aromatic amine derivative which is optionally substituted and wherein n is 2.

[0372] Specific examples of the aryl group having 6 to 30 carbon atoms include benzene, naphthalene, acenaphthylene, fluorenephenalene, phenanthrene, anthracene, fluoranthene, triphenylene, pyrene, Tetracene, perylene, pentacene, etc.

[0373] As aromatic amine derivatives, system, for example, N,N,N',N'-tetraphenyl -6,12-diamine, N,N,N',N'-tetra(p-tolyl) -6,12-diamine, N,N,N',N'-tetra(m-tolyl) -6,12-diamine, N,N,N',N'-tetrakis(4-isopropylphenyl) -6,12-diamine, N,N,N',N'-tetra(naphthalene-2-yl) -6,12-diamine, N,N'-diphenyl-N,N'-di(p-tolyl) -6,12-diamine, N,N'-diphenyl-N,N'-bis(4-ethylphenyl) -6,12-diamine, N,N'-diphenyl-N,N'-bis(4-ethylphenyl) -6,12-diamine, N,N'-diphenyl-N,N'-bis(4-isopropylphenyl) -6,12-diamine, N,N'-diphenyl-N,N'-bis(4-tert-butylphenyl) -6,12-diamine, N,N'-bis(4-isopropylphenyl)-N,N'-di(p-tolyl) -6,12-diamine, etc.

[0374] Examples of the pyrene-based compounds include N,N,N',N'-tetraphenylpyrene-1,6-diamine, N,N,N',N'-tetra(p-tolyl)pyrene-1,6-diamine, N,N,N',N'-tetra(m-tolyl)pyrene-1,6-diamine, N,N,N',N'-tetra(4-isopropylphenyl)pyrene-1,6-diamine, N,N,N',N'-tetra(3,4-dimethylphenyl)pyrene-1,6-diamine, N,N'-diphenyl-N,N'-di(p-tolyl)pyrene-1,6-diamine, N,N'-diphenyl-N,N'-bis(4-ethylphenyl)pyrene-1,6-diamine, and N,N'-diphenyl-N,N'-bis(4-ethylphenyl)pyrene-1,6-diamine. 1,6-diamine, N,N'-diphenyl-N,N'-bis(4-isopropylphenyl)pyrene-1,6-diamine, N,N'-diphenyl-N,N'-bis(4-tert-butylphenyl)pyrene-1,6-diamine, N,N'-bis(4-isopropylphenyl)-N,N'-di(p-tolyl)pyrene-1,6-diamine, N,N,N',N'-tetrakis(3,4-dimethylphenyl)-3,8-diphenylpyrene-1,6-diamine, N,N,N,N-tetraphenylpyrene-1,8-diamine, N,N'-bis(biphenyl-4-yl)-N,N'-diphenylpyrene-1,8-diamine, N 1 ,N 6 -Diphenyl-N 1 ,N 6 -Bis-(4-trimethylsilylphenyl)-1H,8H-pyrene-1,6-diamine, etc.

[0375] For example, specific examples include formulae (PYR1), (PYR2), (PYR3), and (PYR4).

[0376]

[0377] Examples of anthracene-based compounds include N,N,N,N-tetraphenylanthracene-9,10-diamine, N,N,N',N'-tetra(p-tolyl)anthracene-9,10-diamine, N,N,N',N'-tetra(m-tolyl)anthracene-9,10-diamine, N,N,N',N'-tetra(4-isopropylphenyl)anthracene-9,10-diamine, N,N'-diphenyl-N,N'-di(p-tolyl)anthracene-9,10-diamine, and N,N'-diphenyl-N,N'-di(m-tolyl)anthracene-9,10-diamine. 9,10-diamine, N,N'-diphenyl-N,N'-bis(4-ethylphenyl)anthracene-9,10-diamine, N,N'-diphenyl-N,N'-bis(4-isopropylphenyl)anthracene-9,10-diamine, N,N'-diphenyl-N,N'-bis(4-tert-butylphenyl)anthracene-9,10-diamine, N,N'-bis(4-isopropylphenyl)-N,N'-di(p-tolyl)anthracene-9,10-diamine, 2,6-di-tert-butyl-N,N,N',N'-tetra(p-tolyl)anthracene -9,10-diamine, 2,6-di-tert-butyl-N,N'-diphenyl-N,N'-bis(4-isopropylphenyl)anthracene-9,10-diamine, 2,6-di-tert-butyl-N,N'-bis(4-isopropylphenyl)-N,N'-di(p-tolyl)anthracene-9,10-diamine, 2,6-dicyclohexyl-N,N'-bis(4-isopropylphenyl)-N,N'-di(p-tolyl)anthracene-9,10-diamine, 2,6-dicyclohexyl-N,N'-bis(4-isopropylphenyl)-N,N '-Bis(4-tert-butylphenyl)anthracene-9,10-diamine, 9,10-bis(4-diphenylamino-phenyl)anthracene, 9,10-bis(4-di(1-naphthylamino)phenyl)anthracene, 9,10-bis(4-di(2-naphthylamino)phenyl)anthracene, 10-di-p-tolylamino-9-(4-di-p-tolylamino-1-naphthyl)anthracene, 10-diphenylamino-9-(4-diphenylamino-1-naphthyl)anthracene, 10-diphenylamino-9-(6-diphenylamino-2-naphthyl)anthracene, etc.

[0378] Other examples include [4-(4-diphenylamino-phenyl)naphthalene-1-yl]-diphenylamine, [6-(4-diphenylamino-phenyl)naphthalene-2-yl]-diphenylamine, 4,4'-bis[4-diphenylaminonaphthalene-1-yl]biphenyl, 4,4'-bis[6-diphenylaminonaphthalene-2-yl]biphenyl, 4,4"-bis[4-diphenylaminonaphthalene-1-yl]-p-terphenyl, 4,4"-bis[6-diphenylaminonaphthalene-2-yl]-p-terphenyl, and indenocarbazole derivatives.

[0379] Furthermore, aromatic amine derivatives described in JP-A-2006-156888 and the like can also be used.

[0380] The indenocarbazole derivative is a compound represented by the following general formula (IDC1). Specifically, compounds having the following partial structures (IDC11), (IDC12) and (IDC13) are exemplified. In the following general formula (IDC1), each Z is independently CR A or N, π1 and π2 are each independently a substituted or unsubstituted aromatic hydrocarbon having 6 to 50 ring carbon atoms or a substituted or unsubstituted aromatic heterocycle having 5 to 50 ring carbon atoms, R A , R B and R C is hydrogen and any substituent, n and m are each independently an integer of 1 to 4, and two adjacent R A , R B and R C They may be bonded to each other to form a substituted or unsubstituted ring structure. More specifically, general formulae (IDC121), (IDC131), (IDC132), (IDC133) and (IDC134) are mentioned.

[0381] Partial structure of indenocarbazole compounds

[0382]

[0383] Specific compounds of indenocarbazole compounds

[0384]

[0385] Examples of the coumarin derivatives include coumarin-6 and coumarin-334.

[0386] In addition, coumarin derivatives described in Japanese Patent Application Laid-Open Nos. 2004-43646, 2001-76876, and 6-298758 can also be used.

[0387] Examples of the pyran derivative include the following DCM and DCJTB.

[0388]

[0389] Furthermore, pyran derivatives described in JP-A-2005-126399, JP-A-2005-097283, JP-A-2002-234892, JP-A-2001-220577, JP-A-2001-081090, JP-A-2001-052869, and the like can also be used.

[0390] In addition, the phosphor used in the present invention is preferably a compound having a boron atom. As compounds having a boron atom used as phosphors, dioxaborinnaphthoanthracene (DOBNA) derivatives and multimers thereof, diazaborinnaphthoanthracene (DABNA) derivatives and multimers thereof, oxaborinnaphthoanthracene (OABNA) derivatives and multimers thereof, oxaborinnaphthoanthracene (OBNA) derivatives and multimers thereof, azaborinnaphthoanthracene (ABNA) derivatives and multimers thereof, etc. can be cited.

[0391] The organic electroluminescent device of the present invention preferably further contains, as the third component, at least one of the compounds represented by the following general formulae (ED1), (ED1′) and (ED2).

[0392]

[0393] (In the above general formula (ED1),

[0394] R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 9 , R 10 and R 11 are each independently hydrogen, aryl, heteroaryl, diarylamino, diheteroarylamino, arylheteroarylamino, alkyl, cycloalkyl, alkoxy or aryloxy, which are optionally further substituted with aryl, heteroaryl or alkyl, and in addition, R 1 ~R 3 , R 4 ~R 6 and R 9 ~R 11 The adjacent groups in the group are optionally bonded to each other and together with the a ring, the b ring or the c ring form an aromatic ring or a heteroaromatic ring, and the formed ring is optionally substituted by an aryl group, a heteroaryl group, a diarylamino group, a diheteroarylamino group, an arylheteroarylamino group, an alkyl group, a cycloalkyl group, an alkoxy group or an aryloxy group, which are optionally further substituted by an aryl group, a heteroaryl group or an alkyl group,

[0395] X is independently >O or >NR, R of the aforementioned >NR is aryl, heteroaryl, cycloalkyl or alkyl, which is optionally substituted by aryl, heteroaryl, cycloalkyl or alkyl,

[0396] When X is an amino group, R 2 is not amino, and

[0397] At least one hydrogen atom in the compound or structure represented by the general formula (ED1) is optionally replaced by cyano, halogen or deuterium.

[0398]

[0399] (In the above general formula (ED1'),

[0400] R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , R 8 , R 9 , R 10 , R 11 , R 12 , R 13 and R 14 are each independently hydrogen, aryl, heteroaryl, diarylamino, diheteroarylamino, arylheteroarylamino, alkyl, cycloalkyl, alkoxy or aryloxy, which are optionally further substituted with aryl, heteroaryl or alkyl, and in addition, R 1 ~R 3 , R 4 ~R 7 , R 8 ~R 10 and R 11 ~R 14 The adjacent groups are optionally bonded to each other and together with the a ring, b ring, c ring or d ring form an aromatic ring or a heteroaromatic ring, and the formed ring is optionally substituted by an aryl group, a heteroaryl group, a diarylamino group, a diheteroarylamino group, an arylheteroarylamino group, an alkyl group, a cycloalkyl group, an alkoxy group or an aryloxy group, which are optionally further substituted by an aryl group, a heteroaryl group or an alkyl group,

[0401] X is >O or >NR, R of the aforementioned >NR is aryl, heteroaryl or alkyl, which is optionally substituted by aryl, heteroaryl or alkyl,

[0402] L is a single bond, >CR2, >O, >S and >NR, and R in the aforementioned >CR2 and >NR is each independently hydrogen, aryl, heteroaryl, diarylamino, diheteroarylamino, arylheteroarylamino, alkyl, alkoxy or aryloxy, which are optionally further substituted with aryl, heteroaryl or alkyl, and

[0403] At least one hydrogen atom in the compound or structure represented by the general formula (ED1') is optionally replaced by cyano, halogen or deuterium.

[0404]

[0405] (In the above general formula (ED2),

[0406] R 1 , R 2 , R 3, R 4 , R 5 , R 6 , R 7 , R 8 , R 9 , R 10 , R 11 , R 12 , R 13 and R 14 Each is independently hydrogen, aryl, heteroaryl, diarylamino, diheteroarylamino, arylheteroarylamino, alkyl, cycloalkyl, alkoxy, aryloxy, heteroaryloxy, arylthio, heteroarylthio or alkyl-substituted silyl, at least one hydrogen in which is optionally substituted by aryl, heteroaryl or alkyl, and R 5 ~R 7 and R 10 ~R 12 The adjacent groups are optionally bonded to each other and together with the b ring or the d ring form an aromatic ring or a heteroaromatic ring, at least one hydrogen in the formed ring is optionally substituted by an aryl group, a heteroaryl group, a diarylamino group, a diheteroarylamino group, an arylheteroarylamino group, an alkyl group, a cycloalkyl group, an alkoxy group, an aryloxy group, a heteroaryloxy group, an arylthio group, a heteroarylthio group or an alkyl-substituted silyl group, at least one hydrogen in them is optionally substituted by an aryl group, a heteroaryl group or an alkyl group,

[0407] X 1 , X 2 , X 3 and X 4 Each independently represents >O, >NR or >CR2, wherein the R of the aforementioned >NR and the R of >CR2 are aryl groups having 6 to 12 carbon atoms, heteroaryl groups having 2 to 15 carbon atoms, cycloalkyl groups having 3 to 12 carbon atoms or alkyl groups having 1 to 6 carbon atoms, and further, the R of the aforementioned >NR and the R of >CR2 are optionally bonded to at least one of the aforementioned a ring, b ring, c ring and d ring via -O-, -S-, -C(-R)2- or a single bond, and the R of the aforementioned -C(-R)2- is hydrogen or an alkyl group having 1 to 6 carbon atoms,

[0408] Among them, X 1 , X 2 , X 3 , and X 4 There are 2 or fewer groups >O, and

[0409] At least one hydrogen atom in the compound represented by the general formula (ED2) may be substituted by cyano, halogen or deuterium.

[0410] More specifically, compounds having structures represented by the following formulae (ED11) to (ED19), (ED21) to (ED27), (ED211), (ED212), (ED221) to (ED223), (ED231), (ED241), (ED242), (ED261) and (ED271) can be cited.

[0411]

[0412]

[0413]

[0414] At least one hydrogen in the structures represented by formulas (ED11) to (ED19), (ED21) to (ED27), (ED211), (ED212), (ED221) to (ED223), (ED231), (ED241), (ED242), (ED261) and (ED271) is independently optionally substituted by an aryl group, a heteroaryl group, a diarylamino group, a diheteroarylamino group, an arylheteroarylamino group, an alkyl group, a cycloalkyl group, an alkoxy group or an aryloxy group, which are optionally further substituted by an aryl group, a heteroaryl group or an alkyl group. For the preferred range and specific examples of the aryl group, the heteroaryl group, the diarylamino group, the diheteroarylamino group, the arylheteroarylamino group, the alkyl group, the cycloalkyl group, the alkoxy group or the aryloxy group, refer to R in formula (1): 1 ~R 11 It should be noted that in formulas (ED11) and (ED12), the hydrogen bonded to the ortho position of the carbon bonded to B of the benzene ring is not substituted by an alkyl group, and is preferably unsubstituted.

[0415] In addition, the phosphor serving as the third component is preferably a compound having at least one structure selected from the following partial structure group B, and more preferably a compound having a structure represented by formula (ED11) to (ED19), (ED21) to (ED27), (ED211), (ED212), (ED221) to (ED223), (ED231), (ED241), (ED242), (ED261) or (ED271), and having a structure in which at least one structure selected from partial structure group B is bonded to a benzene ring (including a benzene ring constituting a condensed ring) in its structure.

[0416] Partial structure group B:

[0417]

[0418] In each partial structure, Me represents a methyl group, tBu and t-Bu represent a tert-butyl group, and the wavy line represents a bonding position.

[0419] At least one hydrogen in each partial structure is independently optionally substituted by an aryl group, a heteroaryl group, a diarylamino group, a diheteroarylamino group, an arylheteroarylamino group, an alkyl group, an alkoxy group or an aryloxy group, and among these, the hydrogen in the aryl group, the heteroaryl group, the diarylamino group, the diheteroarylamino group and the arylheteroarylamino group is optionally further substituted by an aryl group, a heteroaryl group or an alkyl group. For the preferred range and specific examples of the aryl group, the heteroaryl group, the diarylamino group, the diheteroarylamino group, the arylheteroarylamino group, the alkyl group, the alkoxy group or the aryloxy group, refer to R in formula (1): 1 ~R 11 The corresponding records in .

[0420] The compound used as the third component of the present invention is specifically a compound represented by the following formula.

[0421]

[0422]

[0423]

[0424]

[0425]

[0426]

[0427]

[0428]

[0429]

[0430]

[0431]

[0432]

[0433]

[0434]

[0435]

[0436]

[0437]

[0438]

[0439]

[0440]

[0441]

[0442]

[0443]

[0444]

[0445]

[0446]

[0447]

[0448]

[0449]

[0450]

[0451]

[0452]

[0453]

[0454]

[0455]

[0456]

[0457]

[0458]

[0459]

[0460] (Other organic layers)

[0461] The organic electroluminescent element of the present invention may have one or more organic layers in addition to the light-emitting layer. Examples of the organic layer include an electron transport layer, a hole transport layer, an electron injection layer, and a hole injection layer, and may also have other organic layers.

[0462] Figure 1An example of the layer structure of the organic electroluminescent element including these organic layers is shown in FIG. Figure 1 In the figure, 101 denotes a substrate, 102 denotes an anode, 103 denotes a hole injection layer, 104 denotes a hole transport layer, 105 denotes a light emitting layer, 106 denotes an electron transport layer, 107 denotes an electron injection layer, and 108 denotes a cathode.

[0463] Hereinafter, the organic layer, the cathode, the anode, and the substrate provided in the organic electroluminescent element other than the light-emitting layer will be described.

[0464] 2. Electron injection layer and electron transport layer in organic electroluminescent elements

[0465] The electron injection layer 107 plays a role in efficiently injecting electrons moved from the cathode 108 into the light-emitting layer 105 or the electron transport layer 106. The electron transport layer 106 plays a role in efficiently transporting electrons injected from the cathode 108 or electrons injected from the cathode 108 via the electron injection layer 107 to the light-emitting layer 105. The electron transport layer 106 and the electron injection layer 107 are respectively formed by stacking and mixing one or more electron transport / injection materials.

[0466] The electron injection / transport layer refers to a layer responsible for injecting electrons from the cathode and then transporting electrons, and it is desirable that the electron injection efficiency is high, and the injected electrons are efficiently transported. For this reason, it is preferred that the electron affinity is large and the electron mobility is large, and then the stability is excellent, and it is not easy to produce a substance that becomes a trap impurity when manufacturing and using. However, considering the transport balance of holes and electrons, in the case of mainly playing the role of efficiently preventing the holes from the anode from flowing to the cathode side without recombination, even if the electron transport capacity is not so high, it also has the effect of improving the luminous efficiency equally with the material with high electron transport capacity. Therefore, the electron injection / transport layer in the present embodiment also includes the function of the layer that can efficiently prevent the movement of holes.

[0467] The material (electron transport material) forming the electron transport layer 106 or the electron injection layer 107 can be arbitrarily selected from compounds conventionally used as electron conductive compounds in photoconductive materials and known compounds used in electron injection layers and electron transport layers of organic EL elements.

[0468] As a material used in the electron transport layer or the electron injection layer, it is preferred to contain at least one selected from the following substances: a compound containing an aromatic ring or a heteroaromatic ring composed of one or more atoms selected from carbon, hydrogen, oxygen, sulfur, silicon and phosphorus, a pyrrole derivative and its fused ring derivative, and a metal complex having electron-accepting nitrogen. Specifically, there can be listed fused ring aromatic ring derivatives such as naphthalene and anthracene; styryl aromatic ring derivatives represented by 4,4'-bis(diphenylvinyl)biphenyl; quinone derivatives such as perylene derivatives, coumarin derivatives, naphthalimide derivatives, anthraquinone, and diphenoquinone; phosphorus oxide derivatives, carbazole derivatives, and indole derivatives. As a metal complex having electron-accepting nitrogen, there can be listed hydroxylazole complexes such as hydroxyphenyloxazole complexes; azomethine complexes, tropolone metal complexes, flavonol metal complexes, and benzoquinoline metal complexes. These materials can be used alone or mixed with different materials.

[0469] In addition, specific examples of other electron-conducting compounds include pyridine derivatives, naphthalene derivatives, anthracene derivatives, phenanthroline derivatives, perylene derivatives, coumarin derivatives, naphthalimide derivatives, anthraquinone derivatives, diphenoquinone derivatives, diphenylquinone derivatives, perylene derivatives, oxadiazole derivatives (1,3-bis[(4-tert-butylphenyl)1,3,4-oxadiazolyl]phenylene, etc.), thiophene derivatives, triazole derivatives (N-naphthyl-2,5-diphenyl-1,3,4-triazole, etc.), thiadiazole derivatives, metal complexes of 8-hydroxyquinoline derivatives, hydroxyquinoline metal complexes, quinoxaline derivatives, polymers of quinoxaline derivatives, benzoxazole compounds, gallium complexes, pyrazole derivatives, perfluorinated phenylene derivatives, Biologicals, triazine derivatives, pyrazine derivatives, benzoquinoline derivatives (2,2'-bis(benzo[h]quinolin-2-yl)-9,9'-spirobifluorene, etc.), imidazopyridine derivatives, borane derivatives, benzimidazole derivatives (tris(N-phenylbenzimidazol-2-yl)benzene, etc.), benzoxazole derivatives, benzothiazole derivatives, quinoline derivatives, oligopyridine derivatives such as terpyridine, bipyridine derivatives, terpyridine derivatives (1,3-bis(4'-(2,2':6'2"-terpyridyl))benzene, etc.), naphthyridine derivatives (bis(1-naphthyl)-4-(1,8-naphthyridin-2-yl)phenylphosphine oxide, etc.), aldazine derivatives, carbazole derivatives, indole derivatives, phosphorus oxide derivatives, bisphenylvinyl derivatives, etc.

[0470] In addition, metal complexes having electron-accepting nitrogen may also be used, and examples thereof include hydroxyquinoline metal complexes, hydroxyphenyloxazole complexes and other hydroxyoxazole complexes; azomethine complexes, tropolone metal complexes, flavonol metal complexes, and benzoquinoline metal complexes.

[0471] The above materials can be used alone or mixed with different materials.

[0472] Among the above materials, preferred are borane derivatives, pyridine derivatives, fluoranthene derivatives, BO derivatives, anthracene derivatives, benzofluorene derivatives, phosphine oxide derivatives, pyrimidine derivatives, carbazole derivatives, triazine derivatives, benzimidazole derivatives, phenanthroline derivatives and hydroxyquinoline metal complexes.

[0473] 2-1. Pyridine derivatives

[0474] The pyridine derivative is, for example, a compound represented by the following formula (ETM-2), and preferably a compound represented by formula (ETM-2-1) or formula (ETM-2-2).

[0475] φ-(pyridine substituent)n (ETM-2)

[0476]

[0477] φ is an n-valent aromatic ring (preferably an n-valent benzene ring, naphthalene ring, anthracene ring, fluorene ring, benzofluorene ring, phenalene ring, phenanthrene ring or triphenylene ring), and n is an integer of 1-4.

[0478] In the above formula (ETM-2-1), R 11 ~R 18 Each is independently hydrogen, an alkyl group (preferably an alkyl group having 1 to 24 carbon atoms), a cycloalkyl group (preferably a cycloalkyl group having 3 to 12 carbon atoms), or an aryl group (preferably an aryl group having 6 to 30 carbon atoms).

[0479] In the above formula (ETM-2-2), R 11 and R 12 are each independently hydrogen, alkyl (preferably an alkyl group having 1 to 24 carbon atoms), cycloalkyl (preferably a cycloalkyl group having 3 to 12 carbon atoms), or aryl (preferably an aryl group having 6 to 30 carbon atoms), R 11 With R 12 They are optionally bonded to form a ring.

[0480] In each formula, the "pyridine substituent" is any one of the following formulas (Py-1) to (Py-15), and each pyridine substituent is independently optionally substituted by an alkyl group having 1 to 4 carbon atoms. In addition, the pyridine substituent is optionally bonded to φ, anthracene ring or fluorene ring in each formula via a phenylene group or a naphthylene group.

[0481]

[0482] The pyridine-based substituent is any one of the above-mentioned formulas (Py-1) to (Py-15), and among these, any one of the following formulas (Py-21) to (Py-44) is preferred.

[0483]

[0484] At least one hydrogen atom in each pyridine derivative may be substituted with deuterium, and one of the two "pyridine substituents" in the above formula (ETM-2-1) and formula (ETM-2-2) may be substituted with an aryl group.

[0485] As R 11 ~R 18 The "alkyl" in the formula may be any of a linear chain and a branched chain, and examples thereof include a linear chain alkyl group having 1 to 24 carbon atoms or a branched chain alkyl group having 3 to 24 carbon atoms. A preferred "alkyl group" is an alkyl group having 1 to 18 carbon atoms (a branched chain alkyl group having 3 to 18 carbon atoms). A more preferred "alkyl group" is an alkyl group having 1 to 12 carbon atoms (a branched chain alkyl group having 3 to 12 carbon atoms). A further preferred "alkyl group" is an alkyl group having 1 to 6 carbon atoms (a branched chain alkyl group having 3 to 6 carbon atoms). A particularly preferred "alkyl group" is an alkyl group having 1 to 4 carbon atoms (a branched chain alkyl group having 3 to 4 carbon atoms).

[0486] Specific examples of the “alkyl group” include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, isopentyl, neopentyl, tert-pentyl, n-hexyl, 1-methylpentyl, 4-methyl-2-pentyl, 3,3-dimethylbutyl, 2-ethylbutyl, n-heptyl, 1-methylhexyl, n-octyl, tert-octyl, 1-methylheptyl, 2-ethylhexyl, 2-propylpentyl, n-nonyl, 2,2-dimethylheptyl, 2,6-dimethyl-4-heptyl, 3,5,5-trimethylhexyl, n-decyl, n-undecyl, 1-methyldecyl, n-dodecyl, n-tridecyl, 1-hexylheptyl, n-tetradecyl, n-pentadecyl, n-hexadecyl, n-heptadecyl, n-octadecyl, and n-eicosyl.

[0487] As the alkyl group having 1 to 4 carbon atoms which substitutes the pyridine-based substituent, the above-mentioned description of the alkyl group can be cited.

[0488] As R 11 ~R 18 The "cycloalkyl" in the formula (a) includes, for example, a cycloalkyl group having 3 to 12 carbon atoms. A preferred "cycloalkyl group" is a cycloalkyl group having 3 to 10 carbon atoms. A more preferred "cycloalkyl group" is a cycloalkyl group having 3 to 8 carbon atoms. A further preferred "cycloalkyl group" is a cycloalkyl group having 3 to 6 carbon atoms.

[0489] Specific examples of the "cycloalkyl group" include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, methylcyclopentyl, cycloheptyl, methylcyclohexyl, cyclooctyl and dimethylcyclohexyl.

[0490] As R11 ~R 18 The “aryl group” in the formula (A) is preferably an aryl group having 6 to 30 carbon atoms, more preferably an aryl group having 6 to 18 carbon atoms, further preferably an aryl group having 6 to 14 carbon atoms, and particularly preferably an aryl group having 6 to 12 carbon atoms.

[0491] Specific examples of the "aryl group having 6 to 30 carbon atoms" include phenyl as a monocyclic aromatic group; (1-, 2-) naphthyl as a condensed bicyclic aromatic group; acenaphthyl-(1-, 3-, 4-, 5-)yl, fluorene-(1-, 2-, 3-, 4-, 9-)yl, phenanthren-(1-, 2-)yl, (1-, 2-, 3-, 4-, 9-) phenanthrenyl as a condensed tricyclic aromatic group; triphenylene-(1-, 2-)yl, pyrene-(1-, 2-, 4-)yl, naphthacene-(1-, 2-, 5-)yl as a condensed tetracyclic aromatic group; and perylene-(1-, 2-, 3-)yl and pentacene-(1-, 2-, 5-, 6-)yl as a condensed pentacyclic aromatic group.

[0492] Preferred "aryl group having 6 to 30 carbon atoms" include phenyl, naphthyl, phenanthrenyl, Preferably, it is phenyl, 1-naphthyl, 2-naphthyl or phenanthryl, and more preferably, it is phenyl, 1-naphthyl or 2-naphthyl. More preferably, it is phenyl, 1-naphthyl or 2-naphthyl.

[0493] In the above formula (ETM-2-2), R 11 With R 12 They are optionally bonded to form a ring, and as a result, cyclobutane, cyclopentane, cyclopentene, cyclopentadiene, cyclohexane, fluorene, indene or the like is optionally spiro-bonded to the five-membered ring of the fluorene skeleton.

[0494] Specific examples of the pyridine derivatives include the following compounds.

[0495]

[0496] The pyridine derivative can be produced using known starting materials and known synthesis methods.

[0497] 2-2. Phosphine oxide derivatives

[0498] The phosphine oxide derivative is, for example, a compound represented by the following formula (ETM-7-1). Details are also described in International Publication No. 2013 / 079217.

[0499]

[0500] R 5 is a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, or a heteroaryl group having 5 to 20 carbon atoms,

[0501] R 6 is CN, substituted or unsubstituted alkyl having 1 to 20 carbon atoms, heteroalkyl having 1 to 20 carbon atoms, aryl having 6 to 20 carbon atoms, heteroaryl having 5 to 20 carbon atoms, alkoxy having 1 to 20 carbon atoms, or aryloxy having 6 to 20 carbon atoms,

[0502] R 7 and R 8 are each independently a substituted or unsubstituted aryl group having 6 to 20 carbon atoms or a heteroaryl group having 5 to 20 carbon atoms,

[0503] R 9 is oxygen or sulfur,

[0504] j is 0 or 1, k is 0 or 1, r is an integer of 0-4, and q is an integer of 1-3.

[0505] The phosphine oxide derivative may be, for example, a compound represented by the following formula (ETM-7-2).

[0506]

[0507] R 1 ~R 3 The substituents may be the same or different and are selected from hydrogen, alkyl, cycloalkyl, aralkyl, alkenyl, cycloalkenyl, alkynyl, alkoxy, alkylthio, aryl ether, aryl thioether, aryl, heterocyclic, halogen, cyano, aldehyde, carbonyl, carboxyl, amino, nitro, silyl, and a condensed ring formed between adjacent substituents.

[0508] Ar 1 can be the same or different, and are arylene or heteroarylene, Ar 2 can be the same or different and can be aryl or heteroaryl. 1 and Ar 2 At least one of them has a substituent or a condensed ring is formed between adjacent substituents. n is an integer from 0 to 3, and when n is 0, there is no unsaturated structure part, and when n is 3, there is no R 1 .

[0509] Among these substituents, alkyl represents a saturated aliphatic hydrocarbon group such as methyl, ethyl, propyl, butyl, etc., which may be unsubstituted or substituted. The substituent when substituted is not particularly limited, and examples thereof include alkyl, aryl, heterocyclic group, etc., which are also common in the following descriptions. In addition, the number of carbon atoms in the alkyl group is not particularly limited, and is usually in the range of 1 to 20 from the viewpoint of ease of acquisition and cost.

[0510] The cycloalkyl group represents a saturated alicyclic hydrocarbon group such as cyclopropyl, cyclohexyl, norbornyl, and adamantyl, which may be unsubstituted or substituted. The number of carbon atoms in the alkyl part is not particularly limited, but is usually in the range of 3 to 20.

[0511] In addition, aralkyl represents an aromatic hydrocarbon group such as benzyl and phenylethyl, which is linked to an aliphatic hydrocarbon. Both the aliphatic hydrocarbon and the aromatic hydrocarbon may be unsubstituted or substituted. The number of carbon atoms in the aliphatic part is not particularly limited, but is usually in the range of 1 to 20.

[0512] In addition, the alkenyl group represents an unsaturated aliphatic hydrocarbon group containing a double bond, such as a vinyl group, an allyl group, and a butadienyl group, and these may be unsubstituted or substituted. The number of carbon atoms in the alkenyl group is not particularly limited, but is usually in the range of 2 to 20.

[0513] Furthermore, the cycloalkenyl group represents an unsaturated alicyclic hydrocarbon group containing a double bond, such as a cyclopentenyl group, a cyclopentadienyl group, and a cyclohexenyl group, and these may be unsubstituted or substituted.

[0514] In addition, the alkynyl group represents an unsaturated aliphatic hydrocarbon group containing a triple bond, such as an ethynyl group, and these may be unsubstituted or substituted. The number of carbon atoms in the alkynyl group is not particularly limited, but is usually in the range of 2 to 20.

[0515] In addition, the alkoxy group represents an aliphatic hydrocarbon group through an ether bond, such as a methoxy group, and the aliphatic hydrocarbon group may be unsubstituted or substituted. The number of carbon atoms in the alkoxy group is not particularly limited, but is usually in the range of 1 to 20.

[0516] Furthermore, the alkylthio group is a group in which the oxygen atom of the ether bond of an alkoxy group is substituted with a sulfur atom.

[0517] The aryl ether group represents an aromatic hydrocarbon group through an ether bond, such as a phenoxy group, and the aromatic hydrocarbon group may be unsubstituted or substituted. The number of carbon atoms in the aryl ether group is not particularly limited, but is usually in the range of 6 to 40.

[0518] Furthermore, the aryl thioether group is a group in which the oxygen atom of the ether bond of the aryl ether group is substituted with a sulfur atom.

[0519] In addition, the aryl group represents an aromatic hydrocarbon group such as phenyl, naphthyl, biphenyl, phenanthrenyl, terphenyl, pyrenyl, etc. The aryl group may be unsubstituted or substituted. The number of carbon atoms in the aryl group is not particularly limited, but is usually in the range of 6 to 40.

[0520] In addition, the heterocyclic group represents a cyclic structural group having atoms other than carbon, such as furanyl, thienyl, oxazolyl, pyridyl, quinolyl, carbazolyl, etc., which may be unsubstituted or substituted. The number of carbon atoms in the heterocyclic group is not particularly limited, but is usually in the range of 2 to 30.

[0521] Halogen means fluorine, chlorine, bromine or iodine.

[0522] The group may include a group in which an aldehyde group, a carbonyl group, or an amino group is substituted with an aliphatic hydrocarbon, an alicyclic hydrocarbon, an aromatic hydrocarbon, a heterocycle, or the like.

[0523] Furthermore, aliphatic hydrocarbons, alicyclic hydrocarbons, aromatic hydrocarbons, and heterocycles may be unsubstituted or substituted.

[0524] The silyl group represents a silicon compound group such as trimethylsilyl, and may be unsubstituted or substituted. The number of carbon atoms in the silyl group is not particularly limited, but is usually in the range of 3 to 20. The number of silicon atoms is usually 1 to 6.

[0525] The fused ring formed between adjacent substituents refers to, for example, Ar 1 With R 2 ,Ar 1 With R 3 ,Ar 2 With R 2 ,Ar 2 With R 3 , R 2 With R 3 ,Ar 1 with Ar 2 Here, when n is 1, any two R 1 They form conjugated or non-conjugated fused rings. These fused rings may contain nitrogen, oxygen, or sulfur atoms in the ring structure, and may be further fused with other rings.

[0526] Specific examples of the phosphine oxide derivatives include the following compounds.

[0527]

[0528] The phosphine oxide derivative can be produced using known raw materials and known synthesis methods.

[0529] 2-3. Pyrimidine derivatives

[0530] The pyrimidine derivative is, for example, a compound represented by the following formula (ETM-8), preferably a compound represented by the following formula (ETM-8-1). Details are also described in International Publication No. 2011 / 021689.

[0531]

[0532] Ar is each independently an optionally substituted aryl group or an optionally substituted heteroaryl group. n is an integer of 1 to 4, preferably an integer of 1 to 3, and more preferably 2 or 3.

[0533] Examples of the "aryl group" of the "optionally substituted aryl group" include an aryl group having 6 to 30 carbon atoms, preferably an aryl group having 6 to 24 carbon atoms, more preferably an aryl group having 6 to 20 carbon atoms, and further preferably an aryl group having 6 to 12 carbon atoms.

[0534] Specific examples of "aryl" include phenyl as a monocyclic aromatic group; (2-, 3-, 4-) biphenyl as a bicyclic aromatic group; (1-, 2-) naphthyl as a condensed bicyclic aromatic group; terphenyl (m-terphenyl-2'-yl, m-terphenyl-4'-yl, m-terphenyl-5'-yl, o-terphenyl-3'-yl, o-terphenyl-4'-yl, p-terphenyl-2'-yl, m-terphenyl-2-yl, m-terphenyl-3-yl, m-terphenyl-4-yl, o-terphenyl-2-yl, o-terphenyl-3-yl, o-terphenyl-4-yl, p-terphenyl-2-yl, p-terphenyl-3-yl, p-terphenyl-4-yl); condensed tricyclic aromatic groups include thiazolinyl, anthiazolinyl, anthiazolinyl, anthiazolinyl, anthiazolinyl, anthiazolinyl, anthiazolinyl, anthiazolinyl, anthiazolinyl, anthiazolinyl, anthiazolinyl, anthiazolinyl, anthiazolinyl, anthiazolinyl, anthiazolinyl, anthiazolinyl, anthiazolinyl, anthiazolinyl Acenaphthene-(1-,3-,4-,5-)yl, fluorene-(1-,2-,3-,4-,9-)yl, phenanthene-(1-,2-)yl, (1-,2-,3-,4-,9-)phenanthrenyl; tetraphenyl (5'-phenyl-m-terphenyl-2-yl, 5'-phenyl-m-terphenyl-3-yl, 5'-phenyl-m-terphenyl-4-yl, m-quaterphenyl) as a tetracyclic aromatic group; triphenylene-(1-,2-)yl, pyrene-(1-,2-,4-)yl, tetracene-(1-,2-,5-)yl as a condensed tetracyclic aromatic group; perylene-(1-,2-,3-)yl, pentacene-(1-,2-,5-,6-)yl as a condensed pentacyclic aromatic group, etc.

[0535] Examples of the "heteroaryl group" of the "optionally substituted heteroaryl group" include, for example, a heteroaryl group having 2 to 30 carbon atoms, preferably a heteroaryl group having 2 to 25 carbon atoms, more preferably a heteroaryl group having 2 to 20 carbon atoms, further preferably a heteroaryl group having 2 to 15 carbon atoms, and particularly preferably a heteroaryl group having 2 to 10 carbon atoms. Examples of the heteroaryl group include, for example, a heterocycle containing, in addition to carbon, 1 to 5 hetero atoms selected from oxygen, sulfur and nitrogen as ring atoms.

[0536] Specific examples of the heteroaryl group include furanyl, thienyl, pyrrolyl, oxazolyl, isoxazolyl, thiazolyl, isothiazolyl, imidazolyl, pyrazolyl, oxadiazolyl, furazanyl, thiadiazolyl, triazolyl, tetrazolyl, pyridyl, pyrimidinyl, pyridazinyl, pyrazinyl, triazinyl, benzofuranyl, isobenzofuranyl, benzo[b]thienyl, indolyl, isoindolyl, 1H-indazolyl, benzimidazolyl, benzoxazolyl, benzothiazolyl, 1H-benzotriazolyl, quinolyl, isoquinolyl, cinnolinyl, quinazolinyl, quinoxalinyl, phthalazinyl, naphthyridinyl, purinyl, pteridinyl, carbazolyl, acridinyl, phenoxazinyl, phenothiazinyl, phenazinyl, phenoxathiol, thianthrenyl, and indolizinyl.

[0537] Furthermore, the above-mentioned aryl group and heteroaryl group are optionally substituted, and are optionally substituted, for example, with the above-mentioned aryl group and heteroaryl group, respectively.

[0538] Specific examples of the pyrimidine derivatives include the following compounds.

[0539]

[0540] The pyrimidine derivative can be produced using known starting materials and known synthesis methods.

[0541] 2-4. Triazine derivatives

[0542] The triazine derivative is, for example, a compound represented by the following formula (ETM-10), preferably a compound represented by the following formula (ETM-10-1). Details are described in US Patent Application Publication No. 2011 / 0156013.

[0543]

[0544] Ar is each independently an optionally substituted aryl group or an optionally substituted heteroaryl group. n is an integer of 1 to 4, preferably an integer of 1 to 3, and more preferably 2 or 3.

[0545] Examples of the "aryl group" of the "optionally substituted aryl group" include an aryl group having 6 to 30 carbon atoms, preferably an aryl group having 6 to 24 carbon atoms, more preferably an aryl group having 6 to 20 carbon atoms, and further preferably an aryl group having 6 to 12 carbon atoms.

[0546] Specific examples of "aryl" include phenyl as a monocyclic aromatic group; (2-, 3-, 4-) biphenyl as a bicyclic aromatic group; (1-, 2-) naphthyl as a condensed bicyclic aromatic group; terphenyl (m-terphenyl-2'-yl, m-terphenyl-4'-yl, m-terphenyl-5'-yl, o-terphenyl-3'-yl, o-terphenyl-4'-yl, p-terphenyl-2'-yl, m-terphenyl-2-yl, m-terphenyl-3-yl, m-terphenyl-4-yl, o-terphenyl-2-yl, o-terphenyl-3-yl, o-terphenyl-4-yl, p-terphenyl-2-yl, p-terphenyl-3-yl, p-terphenyl-4-yl); condensed tricyclic aromatic groups include thiazolinyl, anthiazolinyl, anthiazolinyl, anthiazolinyl, anthiazolinyl, anthiazolinyl, anthiazolinyl, anthiazolinyl, anthiazolinyl, anthiazolinyl, anthiazolinyl, anthiazolinyl, anthiazolinyl, anthiazolinyl, anthiazolinyl, anthiazolinyl, anthiazolinyl, anthiazolinyl Acenaphthene-(1-,3-,4-,5-)yl, fluorene-(1-,2-,3-,4-,9-)yl, phenanthene-(1-,2-)yl, (1-,2-,3-,4-,9-)phenanthrenyl; tetraphenyl (5'-phenyl-m-terphenyl-2-yl, 5'-phenyl-m-terphenyl-3-yl, 5'-phenyl-m-terphenyl-4-yl, m-quaterphenyl) as a tetracyclic aromatic group; triphenylene-(1-,2-)yl, pyrene-(1-,2-,4-)yl, tetracene-(1-,2-,5-)yl as a condensed tetracyclic aromatic group; perylene-(1-,2-,3-)yl, pentacene-(1-,2-,5-,6-)yl as a condensed pentacyclic aromatic group, etc.

[0547] Examples of the "heteroaryl group" of the "optionally substituted heteroaryl group" include, for example, a heteroaryl group having 2 to 30 carbon atoms, preferably a heteroaryl group having 2 to 25 carbon atoms, more preferably a heteroaryl group having 2 to 20 carbon atoms, further preferably a heteroaryl group having 2 to 15 carbon atoms, and particularly preferably a heteroaryl group having 2 to 10 carbon atoms. Examples of the heteroaryl group include, for example, a heterocycle containing, in addition to carbon, 1 to 5 hetero atoms selected from oxygen, sulfur and nitrogen as ring atoms.

[0548] Specific examples of the heteroaryl group include furanyl, thienyl, pyrrolyl, oxazolyl, isoxazolyl, thiazolyl, isothiazolyl, imidazolyl, pyrazolyl, oxadiazolyl, furazanyl, thiadiazolyl, triazolyl, tetrazolyl, pyridyl, pyrimidinyl, pyridazinyl, pyrazinyl, triazinyl, benzofuranyl, isobenzofuranyl, benzo[b]thienyl, indolyl, isoindolyl, 1H-indazolyl, benzimidazolyl, benzoxazolyl, benzothiazolyl, 1H-benzotriazolyl, quinolyl, isoquinolyl, cinnolinyl, quinazolinyl, quinoxalinyl, phthalazinyl, naphthyridinyl, purinyl, pteridinyl, carbazolyl, acridinyl, phenoxazinyl, phenothiazinyl, phenazinyl, phenoxathiol, thianthrenyl, and indolizinyl.

[0549] Furthermore, the above-mentioned aryl and heteroaryl groups are optionally substituted, and are each optionally substituted, for example, by the above-mentioned aryl heteroaryl groups.

[0550] Specific examples of the triazine derivatives include the following compounds.

[0551]

[0552] The triazine derivative can be produced using known raw materials and known synthesis methods.

[0553] 2-5. Benzimidazole derivatives

[0554] The benzimidazole derivative is, for example, a compound represented by the following formula (ETM-11).

[0555] φ-(Benzimidazole-based substituent)n (ETM-11)

[0556] φ is an n-valent aromatic ring (preferably an n-valent benzene ring, naphthalene ring, anthracene ring, fluorene ring, benzofluorene ring, phenanthren ring, phenanthren ring or triphenylene ring), n is an integer from 1 to 4, and the "benzimidazole-based substituent" is a substituent obtained by replacing the pyridine group in the "pyridine-based substituent" in the above-mentioned formula (ETM-2), formula (ETM-2-1) and formula (ETM-2-2) with a benzimidazole group, and at least one hydrogen in the benzimidazole derivative is optionally replaced by deuterium.

[0557]

[0558] R in the above benzimidazole group 11 is hydrogen, an alkyl group having 1 to 24 carbon atoms, a cycloalkyl group having 3 to 12 carbon atoms, or an aryl group having 6 to 30 carbon atoms, and R in the above formula (ETM-2-1) and formula (ETM-2-2) can be cited. 11 Description.

[0559] φ is preferably further an anthracene ring or a fluorene ring. In this case, the structure can be referred to the description in the above formula (ETM-2-1) or formula (ETM-2-2). In each formula, R 11 ~R 18 The description in the above formula (ETM-2-1) or formula (ETM-2-2) can be cited. In addition, in the above formula (ETM-2-1) or formula (ETM-2-2), the description is given using the form of two pyridine substituents bonded together, but when they are replaced with benzimidazole substituents, the two pyridine substituents can be replaced with benzimidazole substituents (i.e., n=2), or any one of the pyridine substituents can be replaced with a benzimidazole substituent and the other pyridine substituent can be replaced with R 11 ~R 18 Furthermore, for example, R in the above formula (ETM-2-1) may be replaced by 11 ~R 18At least one of the pyridine substituents is replaced with a benzimidazole substituent, and the pyridine substituent is replaced with R 11 ~R 18 Make a replacement.

[0560] Specific examples of the benzimidazole derivatives include 1-phenyl-2-(4-(10-phenylanthracen-9-yl)phenyl)-1H-benzo[d]imidazole, 2-(4-(10-(naphthalene-2-yl)anthracen-9-yl)phenyl)-1-phenyl-1H-benzo[d]imidazole, 2-(3-(10-(naphthalene-2-yl)anthracen-9-yl)phenyl)-1-phenyl-1H-benzo[d]imidazole, 5-(10-(naphthalene-2-yl)anthracen-9-yl)-1,2-diphenyl-1H-benzo[d]imidazole, imidazole, 1-(4-(10-(naphthalene-2-yl)anthracen-9-yl)phenyl)-2-phenyl-1H-benzo[d]imidazole, 2-(4-(9,10-di(naphthalene-2-yl)anthracen-2-yl)phenyl)-1-phenyl-1H-benzo[d]imidazole, 1-(4-(9,10-di(naphthalene-2-yl)anthracen-2-yl)phenyl)-2-phenyl-1H-benzo[d]imidazole, 5-(9,10-di(naphthalene-2-yl)anthracen-2-yl)-1,2-diphenyl-1H-benzo[d]imidazole, and the like.

[0561]

[0562] The benzimidazole derivative can be produced using known starting materials and known synthesis methods.

[0563] 2-6. Phenanthroline derivatives

[0564] The phenanthroline derivative is, for example, a compound represented by the following formula (ETM-12) or formula (ETM-12-1). Details are described in International Publication No. 2006 / 021982.

[0565]

[0566] φ is an n-valent aromatic ring (preferably an n-valent benzene ring, naphthalene ring, anthracene ring, fluorene ring, benzofluorene ring, phenalene ring, phenanthrene ring or triphenylene ring), and n is an integer of 1-4.

[0567] Various R 11 ~R 18 Each independently represents hydrogen, an alkyl group (preferably an alkyl group having 1 to 24 carbon atoms), a cycloalkyl group (preferably a cycloalkyl group having 3 to 12 carbon atoms), or an aryl group (preferably an aryl group having 6 to 30 carbon atoms). 11 ~R 18 Any of them is bonded to φ which is an aromatic ring.

[0568] At least one hydrogen atom in each phenanthroline derivative is optionally replaced by deuterium.

[0569] As R 11 ~R 18 The alkyl, cycloalkyl and aryl groups in the formula (ETM-2) may be R 11 ~R 18 In addition to the above examples, φ may also be represented by the following structural formula. It should be noted that R in the following structural formula is independently hydrogen, methyl, ethyl, isopropyl, cyclohexyl, phenyl, 1-naphthyl, 2-naphthyl, biphenyl or terphenyl.

[0570]

[0571] Specific examples of the phenanthroline derivatives include 4,7-diphenyl-1,10-phenanthroline, 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline, 9,10-di(1,10-phenanthroline-2-yl)anthracene, 2,6-di(1,10-phenanthroline-5-yl)pyridine, 1,3,5-tri(1,10-phenanthroline-5-yl)benzene, 9,9'-difluorobis(1,10-phenanthroline-5-yl), bathocuproin, and 1,3-bis(2-phenyl-1,10-phenanthroline-9-yl)benzene.

[0572]

[0573] The phenanthroline derivative can be produced using known raw materials and known synthesis methods.

[0574] 2-7. Hydroxyquinoline metal complexes

[0575] The hydroxyquinoline metal complex is, for example, a compound represented by the following general formula (ETM-13).

[0576]

[0577] In the formula, R 1 ~R 6 is hydrogen or a substituent, M is Li, Al, Ga, Be or Zn, and n is an integer of 1 to 3.

[0578] Specific examples of the hydroxyquinoline metal complex include 8-hydroxyquinoline lithium, tris(8-hydroxyquinoline)aluminum, tris(4-methyl-8-hydroxyquinoline)aluminum, tris(5-methyl-8-hydroxyquinoline)aluminum, tris(3,4-dimethyl-8-hydroxyquinoline)aluminum, tris(4,5-dimethyl-8-hydroxyquinoline)aluminum, tris(4,6-dimethyl-8-hydroxyquinoline)aluminum, bis(2-methyl-8-hydroxyquinoline)(phenol)aluminum, bis(2-methyl-8-hydroxyquinoline)(2-methylphenol)aluminum, bis(2-methyl-8-hydroxyquinoline)(3-methylphenol)aluminum, bis(2-methyl-8-hydroxyquinoline)(4-methylphenol)aluminum, bis(2-methyl-8-hydroxyquinoline)(5-methylphenol)aluminum, bis(3-methylphenol)aluminum, bis(4,5-dimethyl-8-hydroxyquinoline)aluminum, bis(4,6-dimethyl-8-hydroxyquinoline)aluminum, bis(2-methyl-8-hydroxyquinoline)(phenol)aluminum, bis(2-methyl-8-hydroxyquinoline)(2-methylphenol)aluminum, bis(2-methyl-8-hydroxyquinoline)(3-methylphenol)aluminum, bis(2-methyl-8-hydroxyquinoline)(5-methylphenol)aluminum, bis(3-methylphenol)aluminum, bis(4,5-dimethyl-8-hydroxyquinoline)aluminum, bis(4,6-dimethyl-8-hydroxyquinoline)aluminum, bis(2-methyl-8-hydroxyquinoline)(phenol)aluminum, bis(2-methyl-8-hydroxyquinoline)(2-methylphenol)aluminum, bis(3-methylphenol)aluminum, bis(4,5-dimethyl-8- 2-methyl-8-hydroxyquinoline)(4-methylphenol)aluminum, bis(2-methyl-8-hydroxyquinoline)(2-phenylphenol)aluminum, bis(2-methyl-8-hydroxyquinoline)(3-phenylphenol)aluminum, bis(2-methyl-8-hydroxyquinoline)(4-phenylphenol)aluminum, bis(2-methyl-8-hydroxyquinoline)(2,3-dimethylphenol)aluminum, bis(2-methyl-8-hydroxyquinoline)(2,6-dimethylphenol)aluminum, bis(2-methyl-8-hydroxyquinoline)(3,4-dimethylphenol)aluminum, bis(2-methyl-8-hydroxyquinoline)(3,5-dimethylphenol ) aluminum, bis(2-methyl-8-hydroxyquinoline)(3,5-di-tert-butylphenol)aluminum, bis(2-methyl-8-hydroxyquinoline)(2,6-diphenylphenol)aluminum, bis(2-methyl-8-hydroxyquinoline)(2,4,6-triphenylphenol)aluminum, bis(2-methyl-8-hydroxyquinoline)(2,4,6-trimethylphenol)aluminum, bis(2-methyl-8-hydroxyquinoline)(2,4,5,6-tetramethylphenol)aluminum, bis(2-methyl-8-hydroxyquinoline)(1-naphthol)aluminum, bis(2-methyl-8-hydroxyquinoline)(2-naphthol)aluminum, bis(2,4-dimethyl bis(2,4-dimethyl-8-hydroxyquinoline)(2-phenylphenol)aluminum, bis(2,4-dimethyl-8-hydroxyquinoline)(3-phenylphenol)aluminum, bis(2,4-dimethyl-8-hydroxyquinoline)(4-phenylphenol)aluminum, bis(2,4-dimethyl-8-hydroxyquinoline)(3,5-dimethylphenol)aluminum, bis(2,4-dimethyl-8-hydroxyquinoline)(3,5-di-tert-butylphenol)aluminum, bis(2-methyl-8-hydroxyquinoline)aluminum-μ-oxo-bis(2-methyl-8-hydroxyquinoline)aluminum, bis(2,4-dimethyl-8-hydroxyquinoline)aluminum-μ-oxo-bis(2,4-dimethyl-8-hydroxyquinoline) aluminum, bis(2-methyl-4-ethyl-8-hydroxyquinoline) aluminum-μ-oxo-bis(2-methyl-4-ethyl-8-hydroxyquinoline) aluminum, bis(2-methyl-4-methoxy-8-hydroxyquinoline) aluminum-μ-oxo-bis(2-methyl-4-methoxy-8-hydroxyquinoline) aluminum, bis(2-methyl-5-cyano-8-hydroxyquinoline) aluminum-μ-oxo-bis(2-methyl-5-cyano-8-hydroxyquinoline) aluminum, bis(2-methyl-5-trifluoromethyl-8-hydroxyquinoline) aluminum-μ-oxo-bis(2-methyl-5-trifluoromethyl-8-hydroxyquinoline) aluminum, bis(10-hydroxybenzo[h]quinoline) beryllium, etc.

[0579] The hydroxyquinoline metal complex can be produced using known raw materials and a known synthesis method.

[0580] 3. Cathode in organic electroluminescent element

[0581] The cathode 108 plays a role of injecting electrons into the light-emitting layer 105 via the electron injection layer 107 and the electron transport layer 106 .

[0582] As the material forming the cathode 108, as long as it is a substance that can efficiently inject electrons into the organic layer, there is no particular limitation, and the same material as the material forming the anode 102 can be used. Among them, preferably metals such as tin, indium, calcium, aluminum, silver, copper, nickel, chromium, gold, platinum, iron, zinc, lithium, sodium, potassium, cesium and magnesium or their alloys (magnesium-silver alloy, magnesium-indium alloy, aluminum-lithium alloy such as lithium fluoride / aluminum, etc.) and the like. In order to improve the efficiency of electron injection and improve the characteristics of the element, lithium, sodium, potassium, cesium, calcium, magnesium or alloys containing these low work function metals are effective. However, these low work function metals are usually unstable in the atmosphere. In order to improve this point, it is known that, for example, a method of doping a trace amount of lithium, cesium, and magnesium into the organic layer and using an electrode with high stability. As other dopants, inorganic salts such as lithium fluoride, cesium fluoride, lithium oxide and cesium oxide can also be used. But it is not limited to them.

[0583] Furthermore, in order to protect the electrodes, preferred examples include laminating metals such as platinum, gold, silver, copper, iron, tin, aluminum and indium or alloys using these metals, inorganic substances such as silicon dioxide, titanium dioxide and silicon nitride, polyvinyl alcohol, vinyl chloride, hydrocarbon polymer compounds, etc. The method for making these electrodes is resistance heating, electron beam evaporation, sputtering, ion plating and coating, etc., and there is no particular limitation as long as conduction can be achieved.

[0584] 4. Hole injection layer and hole transport layer in organic electroluminescent elements

[0585] The hole injection layer 103 plays a role in efficiently injecting holes moved from the anode 102 into the light-emitting layer 105 or the hole transport layer 104. The hole transport layer 104 plays a role in efficiently transporting holes injected from the anode 102 or holes injected from the anode 102 via the hole injection layer 103 to the light-emitting layer 105. The hole injection layer 103 and the hole transport layer 104 are respectively formed by stacking and mixing one or more hole injection / transport materials, or by a mixture of a hole injection / transport material and a polymer binder. In addition, an inorganic salt such as iron (III) chloride can be added to the hole injection / transport material to form a layer.

[0586] As a hole injection / transport material, it is necessary to efficiently inject / transport holes from the positive electrode between electrodes to which an electric field is applied, and it is ideal to have high hole injection efficiency and efficiently transport the injected holes. For this reason, it is preferred that the material has a small ionization potential and a large hole mobility, and thus has excellent stability, and is not prone to produce impurities that become traps during manufacture and use.

[0587] Materials for forming the hole injection layer 103 and the hole transport layer 104 can be selected from compounds conventionally used as hole charge transport materials in photoconductive materials, and known materials used in hole injection layers and hole transport layers of p-type semiconductors and organic electroluminescent elements. Specific examples thereof include carbazole derivatives (N-phenylcarbazole, polyvinylcarbazole, etc.), biscarbazole derivatives such as bis(N-arylcarbazole) or bis(N-alkylcarbazole); triarylamine derivatives (polymers having aromatic tertiary amino groups in the main chain or side chain, 1,1-bis(4-di-p-tolylaminophenyl)cyclohexane, N,N'-diphenyl-N,N'-di(3-methylphenyl)-4,4'-diaminobiphenyl, N,N'-diphenyl-N,N'-dinaphthyl-4,4'-diaminobiphenyl, N,N'-diphenyl-N,N'-di(3-methylphenyl)-4,4'-diphenyl-1,1'-diamine, N,N'-dinaphthyl-N,N'-diphenyl-4,4'-diphenyl-1,1'-diamine, N 4 ,N 4’ -Diphenyl-N 4 ,N 4’ -Bis(9-phenyl-9H-carbazole-3-yl)-[1,1'-biphenyl]-4,4'-diamine, N 4 ,N 4 ,N 4’ ,N 4’-tetrakis[1,1'-biphenyl]-4-yl)-[1,1'-biphenyl]-4,4'-diamine, 4,4',4"-tris(3-methylphenyl(phenyl)amino)triphenylamine and other triphenylamine derivatives; star amine derivatives, etc.), stilbene derivatives, phthalocyanine derivatives (metal-free, copper phthalocyanine, etc.), dihydropyrazole derivatives, hydrazone compounds, benzofuran derivatives, thiophene derivatives, oxadiazole derivatives, quinoxaline derivatives (for example, 1,4,5,8,9,12-hexaazatriphenylene-2,3,6,7,10,11-hexacarbonitrile, etc.), porphyrin derivatives and other heterocyclic compounds; polysilane, etc. In the polymer system, polycarbonate, styrene derivatives, polyvinylcarbazole and polysilane having the above-mentioned monomers in the side chain are preferred, and there is no particular limitation as long as the compound can form a thin film necessary for the preparation of a light-emitting element, can inject holes from the anode, and can further transport holes.

[0588] In addition, it is also known that the conductivity of organic semiconductors is strongly affected by their doping. This organic semiconductor matrix material is composed of a compound with good electron donation or a compound with good electron acceptance. In order to dope electron donation materials, strong electron acceptors such as tetracyanoquinodimethane (TCNQ) or 2,3,5,6-tetrafluorotetracyano-1,4-benzoquinodimethane (F4TCNQ) are known (for example, see the document "M. Pfeiffer, A. Beyer, T. Fritz, K. Leo, Appl. Phys. Lett., 73 (22), 3202-3204 (1998)" and the document "J. Blochwitz, M. Pheiffer, T. Fritz, K. Leo, Appl. Phys. Lett., 73 (6), 729-731 (1998)"). They generate so-called holes through the electron migration process in the electron donation type basic material (hole transport material). The conductivity of the base material varies significantly depending on the number and mobility of holes. As a base material having hole transport properties, for example, benzidine derivatives (TPD, etc.) or star amine derivatives (TDATA, etc.) or specific metal phthalocyanines (especially zinc phthalocyanine ZnPc, etc.) are known (Japanese Patent Publication No. 2005-167175).

[0589] 5. Anode in organic electroluminescent element

[0590] The anode 102 plays a role in injecting holes into the light-emitting layer 105. When a hole injection layer 103 and / or a hole transport layer 104 are provided between the anode 102 and the light-emitting layer 105, holes are injected into the light-emitting layer 105 through them.

[0591] As materials for forming the anode 102, inorganic compounds and organic compounds can be listed. As inorganic compounds, for example, metals (aluminum, gold, silver, nickel, palladium, chromium, etc.), metal oxides (indium oxide, tin oxide, indium-tin oxide (ITO), indium-zinc oxide (IZO), etc.), halogenated metals (copper iodide, etc.), copper sulfide, carbon black, ITO glass, Nesser glass, etc. can be listed. As organic compounds, for example, polythiophenes such as poly(3-methylthiophene), polypyrrole, conductive polymers such as polyaniline, etc. can be listed. In addition, it can be appropriately selected from the substances used as the anode of the organic electroluminescent element for use.

[0592] The resistance of the transparent electrode is not limited as long as it can supply sufficient current for the light emitting element to emit light. From the perspective of the power consumption of the light emitting element, a low resistance is preferred. For example, if it is an ITO substrate below 300Ω / □, it functions as an element electrode, but substrates of about 10Ω / □ can also be supplied now. Therefore, it is particularly desirable to use a low resistance product such as 100 to 5Ω / □, preferably 50 to 5Ω / □. The thickness of ITO can be arbitrarily selected according to the resistance value, and is usually used between 50 and 300nm.

[0593] 6. Substrate in organic electroluminescent elements

[0594] The substrate 101 becomes the support of the organic electroluminescent element 100, and quartz, glass, metal, plastic, etc. can be generally used. The substrate 101 is formed into a plate, film or sheet according to the purpose, and for example, a glass plate, a metal plate, a metal foil, a plastic film, a plastic sheet, etc. can be used. Among them, glass plates and transparent synthetic resin plates such as polyester, polymethacrylate, polycarbonate, polysulfone, etc. are preferred. If it is a glass substrate, soda-lime glass, alkali-free glass, etc. can be used. In addition, the thickness can be sufficient for maintaining mechanical strength, as long as it is, for example, 0.2 mm or more. As the upper limit of the thickness, for example, it is less than 2 mm, preferably less than 1 mm. Regarding the material of the glass, it is better when the ions dissolved from the glass are small, so alkali-free glass is preferably used. Soda-lime glass with an isolation coating such as SiO2 is also commercially available, so this glass can be used. In order to improve the gas barrier properties, a gas barrier film such as a dense silicon oxide film may be provided on at least one surface of the substrate 101. In particular, when a plate, film or sheet made of a synthetic resin with low gas barrier properties is used as the substrate 101, it is preferable to provide a gas barrier film.

[0595] 7. Method for manufacturing organic electroluminescent element

[0596] Each layer constituting an organic electroluminescent element can be formed by making the material to constitute each layer into a thin film using a method such as vapor deposition, resistance heating vapor deposition, electron beam vapor deposition, sputtering, molecular stacking, printing, spin coating, cast film, coating, etc. The film thickness of each layer formed in this way is not particularly limited and can be appropriately set according to the properties of the material, usually in the range of 2nm to 5000nm. The film thickness can usually be measured by a quartz oscillation film thickness measuring device or the like. When using the vapor deposition method for thin film formation, the vapor deposition conditions vary depending on the type of material, the target crystal structure and association structure of the film, etc. The vapor deposition conditions are usually preferably in the range of +50 to +400°C for the heating temperature of the vapor deposition crucible and 10 -6 ~10 -3 Pa, the vapor deposition rate is 0.01 to 50 nm / sec, the substrate temperature is -150 to +300°C, and the film thickness is appropriately set within the range of 2 nm to 5 μm.

[0597] Next, as an example of a method for producing an organic electroluminescent element, a method for producing an organic electroluminescent element including an anode / hole injection layer / hole transport layer / light-emitting layer containing a main compound, a thermally activated delayed phosphor and a compound having a boron atom / electron transport layer / electron injection layer / cathode is described.

[0598] 7-1. Evaporation method

[0599] On a suitable substrate, after forming a thin film of an anode material by a vapor deposition method, a thin film of a hole injection layer and a hole transport layer is formed on the anode. A host compound, a thermally activated delayed phosphor, and a compound having a boron atom are co-evaporated thereon to form a thin film to form a light-emitting layer, an electron transport layer and an electron injection layer are formed on the light-emitting layer, and then a thin film containing a cathode material is formed by a vapor deposition method, thereby obtaining a target organic electroluminescent element. It should be noted that in the production of the above-mentioned organic electroluminescent element, the production order can also be reversed, and it can be produced according to the order of cathode, electron injection layer, electron transport layer, light-emitting layer, hole transport layer, hole injection layer, and anode.

[0600] 7-2. Wet film forming method

[0601] In the case of the light-emitting layer-forming composition, a film is formed by using a wet film-forming method.

[0602] In general, the wet film-forming method forms a coating film by going through a coating process of applying a light-emitting layer-forming composition on a substrate and a drying process of removing the solvent from the applied light-emitting layer-forming composition. According to the difference in the coating process, the method using a spin coater is called a spin coating method, the method using a slit coater is called a slit coating method, the method using a plate is called a gravure, an offset plate, a reverse offset plate, a flexographic printing method, the method using an inkjet printer is called an inkjet method, and the method of spraying in a mist state is called a spray method. The drying process includes air drying, heating, and reduced pressure drying. The drying process can be performed only once, or it can be performed multiple times using different methods and conditions. In addition, different methods can also be used, such as calcining under reduced pressure.

[0603] The wet film forming method refers to a film forming method using a solution, for example, a part of the printing method (inkjet method), spin coating or casting method, coating method, etc. The wet film forming method is different from the vacuum evaporation method, which does not require the use of expensive vacuum evaporation equipment and can form a film under atmospheric pressure. In addition, the wet film forming method can be large-scale and continuous production, which helps to reduce manufacturing costs.

[0604] On the other hand, compared with the vacuum evaporation method, the wet film forming method is difficult to laminate. When using the wet film forming method to make a laminated film, it is necessary to prevent the lower layer from being dissolved by the composition of the upper layer, and use a composition with controlled solubility, crosslinking of the lower layer, and orthogonal solvents (orthogonal solvents, mutually immiscible solvents), etc. However, even if these technologies are used, it is sometimes difficult to use the wet film forming method in the coating of the entire film.

[0605] Therefore, a method is generally adopted in which only a few layers are formed using a wet film forming method and the rest are formed using a vacuum evaporation method to produce an organic EL element.

[0606] For example, the following shows a process for producing an organic EL element by partially applying a wet film-forming method.

[0607] (Step 1) Anode film formation by vacuum evaporation method

[0608] (Step 2) Formation of Hole Injection Layer by Wet Film Formation Method

[0609] (Step 3) Formation of hole transport layer by wet film formation method

[0610] (Step 4) Film formation of a light-emitting layer-forming composition containing a host compound, a thermally activated delayed phosphor, and a compound having a boron atom by a wet film-forming method

[0611] (Step 5) Film Formation of Electron Transport Layer by Vacuum Deposition

[0612] (Step 6) Film Formation of Electron Injection Layer by Vacuum Deposition

[0613] (Step 7) Formation of cathode film by vacuum evaporation method

[0614] By going through these steps, an organic EL element composed of anode / hole injection layer / hole transport layer / light-emitting layer including a host material and a dopant material / electron transport layer / electron injection layer / cathode is obtained.

[0615] 8. Application examples of organic electroluminescent elements

[0616] Furthermore, the present invention can also be applied to a display device including an organic electroluminescent element or a lighting device including an organic electroluminescent element.

[0617] A display device or lighting device having an organic electroluminescent element can be manufactured by a known method such as connecting the organic electroluminescent element of this embodiment to a known driving device, and can be driven using a known driving method such as DC driving, pulse driving, AC driving, etc. as appropriate.

[0618] As display devices, panel displays such as color flat panel displays, flexible displays such as flexible color organic electroluminescent (EL) displays, etc. can be listed (for example, see Japanese Patent Publication No. 10-335066, Japanese Patent Publication No. 2003-321546, Japanese Patent Publication No. 2004-281086, etc.). In addition, as display modes of displays, matrix mode and / or segment mode can be listed. It should be noted that matrix display and segment display can coexist in the same panel.

[0619] In the matrix, the pixels used for display are arranged two-dimensionally in a grid shape, a mosaic shape, etc., and text and images are displayed by a collection of pixels. The shape and size of the pixel are determined according to the purpose. For example, in the image and text display of personal computers, monitors, and televisions, quadrilateral pixels with a single side of less than 300μm are usually used. In addition, in the case of large displays such as display panels, pixels with a single side of the order of mm are used. In the case of monochrome display, it is sufficient to arrange pixels of the same color. In the case of color display, red, green, and blue pixels are arranged and displayed. In this case, typically, there are triangle types and stripe types. In addition, as a driving method of the matrix, it can be any one of a line sequential driving method and an active matrix. Line sequential driving has the advantage of a simple structure, but when considering the working characteristics, the active matrix is ​​sometimes more excellent, so it also needs to be distinguished and used according to the purpose.

[0620] In the segment method (type), a pattern is formed in a manner to display predetermined information, and the predetermined area is illuminated. Examples include time and temperature displays in digital clocks and thermometers, operating status displays of audio equipment, induction cookers, etc., and panel displays of automobiles.

[0621] As lighting devices, lighting devices such as indoor lighting, backlights of liquid crystal display devices, etc. can be listed (for example, see Japanese Patent Publication No. 2003-257621, Japanese Patent Publication No. 2003-277741, Japanese Patent Publication No. 2004-119211, etc.). Backlights are mainly used for the purpose of improving the viewing of display devices that do not emit light by themselves, and are used for liquid crystal display devices, clocks, audio devices, automobile panels, display boards, and logos. In particular, as a backlight for liquid crystal display devices, especially personal computers where thinning is a problem, if considering that the previous method is difficult to be thinned because it is composed of fluorescent lamps and light guide plates, the backlight using the light-emitting element of this embodiment has the characteristics of being thin and lightweight.

[0622] Example

[0623] Hereinafter, the present invention will be specifically described by way of examples, but the present invention is not limited to these examples at all. Hereinafter, synthesis examples of the compounds used in the examples are shown.

[0624] <Evaluation Methods of Basic Physical Properties>

[0625] Sample preparation

[0626] When evaluating the absorption characteristics and luminescence characteristics (fluorescence and phosphorescence) of the evaluation object compound, there are cases where the evaluation object compound is dissolved in a solvent and evaluated in the solvent and cases where the evaluation is performed in a thin film state. Furthermore, when evaluating in a thin film state, depending on the use of the evaluation object compound in the organic EL element, there are cases where the evaluation object compound is only evaluated in the form of a thin film and cases where the evaluation object compound is dispersed in an appropriate matrix material and evaluated in the form of a thin film. Here, the thin film obtained by vapor deposition of only the evaluation object compound is referred to as a "single film", and the thin film obtained by applying a coating solution containing the evaluation object compound and the matrix material and drying it is referred to as a "coating film".

[0627] As the matrix material, commercially available PMMA (polymethyl methacrylate) etc. can be used. In this example, PMMA and the compound to be evaluated were dissolved in toluene, and then formed into a thin film on a transparent supporting substrate (10 mm×10 mm) made of quartz by spin coating to prepare a sample.

[0628] In addition, a thin film sample in which the matrix material is a host compound is prepared as follows.

[0629] A transparent supporting substrate made of quartz (10 mm × 10 mm × 1.0 mm) was fixed to a substrate holder of a commercially available vapor deposition apparatus (manufactured by Choshu Sangyo Co., Ltd.), and a molybdenum vapor deposition boat containing a host compound and a molybdenum vapor deposition boat containing a dopant material were installed. The vacuum chamber was depressurized to 5 × 10 -4 Pa. Next, the evaporation boat containing the host compound and the evaporation boat containing the dopant material are heated simultaneously, and the host compound and the dopant material are co-evaporated in a manner to form an appropriate film thickness to form a mixed thin film (sample) of the host compound and the dopant material. Here, the evaporation speed is controlled according to the set weight ratio of the host compound to the dopant material.

[0630] Evaluation of absorption and luminescence characteristics

[0631] The absorption spectrum of the sample was measured using an ultraviolet-visible-near-infrared spectrophotometer (UV-2600, manufactured by Shimadzu Corporation). The fluorescence spectrum or phosphorescence spectrum of the sample was measured using a spectrofluorophotometer (F-7000, manufactured by Hitachi HITECH Co., Ltd.).

[0632] For the measurement of fluorescence spectrum, the sample was excited at room temperature using an appropriate excitation wavelength and the photoluminescence was measured. For the measurement of phosphorescence spectrum, the sample was immersed in liquid nitrogen (temperature 77K) using an attached cooling unit. In order to observe the phosphorescence spectrum, an optical chopper was used to adjust the delay time from the irradiation of the excitation light to the start of the measurement. The sample was excited using an appropriate excitation wavelength and the photoluminescence was measured.

[0633] In addition, the fluorescence quantum yield (PLQY) was measured using an absolute PL quantum yield measuring device (manufactured by Hamamatsu Photonics, C9920-02G).

[0634] Evaluation of fluorescence lifetime (delayed fluorescence)

[0635] The fluorescence lifetime was measured at 300K using a fluorescence lifetime measuring device (manufactured by Hamamatsu Photonics, C11367-01). Specifically, the luminescent component with a fast fluorescence lifetime and the luminescent component with a slow fluorescence lifetime were observed at the maximum emission wavelength measured using an appropriate excitation wavelength. In the fluorescence lifetime measurement at room temperature of a general organic EL material that emits fluorescence, the slow luminescent component in which the triplet component from phosphorescence participates is hardly observed due to the deactivation of the triplet component caused by heat. When a slow luminescent component is observed in the evaluation object compound, the triplet energy indicating a long excitation lifetime moves to the singlet energy due to thermal activation and is observed in the form of delayed fluorescence.

[0636] Calculation of Energy Gap (Eg)

[0637] From the long-wavelength end A (nm) of the absorption spectrum obtained by the above method, it is calculated by Eg=1240 / A.

[0638] Determination of ionization potential (Ip)

[0639] A transparent support substrate (28 mm × 26 mm × 0.7 mm) on which ITO (indium tin oxide) was deposited was fixed to a substrate holder of a commercially available deposition apparatus (manufactured by Choshu Sangyo Co., Ltd.), and a molybdenum deposition boat containing the target compound was mounted. The vacuum chamber was depressurized to 5 × 10 -4 Pa. Next, the deposition boat is heated to evaporate the target compound, thereby forming a single film (Neat film) of the target compound.

[0640] The obtained single film was used as a sample, and the ionization potential of the target compound was measured using a photoelectron spectrometer (Sumitomo Heavy Industries, Ltd. PYS-201).

[0641] Calculation of Electron Affinity (Ea)

[0642] The electron affinity was estimated from the difference between the ionization potential measured by the aforementioned method and the energy gap calculated by the aforementioned method.

[0643] Determination of excited singlet energy level E(S,Sh) and excited triplet energy level E(T,Sh)

[0644] For a single film of the target compound formed on a glass substrate, the fluorescence spectrum is observed at 77K to the extent that the fluorescence peaks of the absorption spectrum do not overlap and with the peak on the long wavelength side as the excitation light, and the excited singlet energy level E(S,Sh) is calculated based on the shoulder on the short wavelength side of the peak of the fluorescence spectrum.

[0645] In addition, for a single film of the target compound formed on a glass substrate, the phosphorescence spectrum is observed at 77K to the extent that the fluorescence peaks of the absorption spectrum do not overlap and with the peak on the long wavelength side as the nm excitation light, and the excited triplet energy level E(T,Sh) is calculated based on the shoulder on the short wavelength side of the peak of the phosphorescence spectrum.

[0646] [1] Evaluation of basic physical properties of compounds

[0647] (Experimental Example 1) Evaluation of basic physical properties of the compound (BO2-0511S) as the first component (host compound)

[0648] The basic physical properties of the compound (BO2-0511S) alone were evaluated, and the ionization potential was 6.30 eV, the electron affinity was 3.26 eV, and the energy gap was 3.04 eV. In addition, the excited singlet energy level E(1,S,Sh) was 2.94 eV, and the excited triplet energy level E(1,T,Sh) was 2.74 eV.

[0649] (Comparative Experimental Example 1) Evaluation of Basic Physical Properties of Comparative Compound (mCBP) as First Component (Host Compound)

[0650] The basic physical properties of the comparative compound (mCBP) alone were evaluated, and the ionization potential was 6.07 eV, the electron affinity was 2.55 eV, and the energy gap was 3.52 eV. In addition, the excited singlet energy level E(1, S, Sh) was 4.19 eV, and the excited triplet energy level E(1, T, Sh) was 2.78 eV.

[0651] (Experimental Example 2) Evaluation of Basic Physical Properties of the Compound (Cz-TRZ3) as the Second Component (Assisted Dopant)

[0652] The basic physical properties of the single film of the compound (Cz-TRZ3) were evaluated, and the ionization potential was 5.93 eV, the electron affinity was 2.99 eV, and the energy gap was 2.94 eV. In addition, the excited singlet energy level E(2,S,Sh) was 2.92 eV, and the excited triplet energy level E(2,T,Sh) was 2.69 eV. Furthermore, the excited singlet energy level E(2,S,PT) at the peak was 2.76 eV, the excited triplet energy level E(2,T,Sh) at the peak was 2.58 eV, and ΔEST was 0.18 eV.

[0653] (Experimental Example 3) Evaluation of Basic Physical Properties of Compound (ED1) as Third Component (Light Emitting Dopant)

[0654] The fluorescence spectrum of the coating film of compound (ED1) and PMMA as a matrix material was measured at room temperature based on 340 nm excitation light. Here, the concentration of compound (ED1) in the coating film was set to 1% by weight. The maximum emission wavelength of the measured fluorescence spectrum was 465 nm and the half-value width was 19 nm.

[0655] [2] Fabrication and evaluation of organic EL elements

[0656] In this example, an organic EL element was produced according to the structure described in Adv. Mater. 2016, 28, 2777-2781). The layer structure of the produced organic EL element is shown in Table 1.

[0657] [Table 1]

[0658] (Structure of Organic EL Element A)

[0659]

[0660] In Table 1, "NPD" is N,N'-diphenyl-N,N'-dinaphthyl-4,4'-diaminobiphenyl, "TcTa" is 4,4',4"-tri(N-carbazolyl)triphenylamine, "mCP" is 1,3-bis(N-carbazolyl)benzene, "mCBP" is 3,3'-bis(N-carbazolyl)-1,1'-biphenyl, "BPy-TP2" is 2,7-di([2,2'-bipyridyl]-5-yl)triphenylene, and "2CzBN" is 3,4-dicarbazolylbenzonitrile.

[0661] <Example 1>

[0662] Preparation and evaluation of element 1 using compound (BO2-0511S) as a host compound, compound (Cz-TRZ3) as an auxiliary dopant, and compound (ED1) as a light-emitting dopant

[0663] On a glass substrate (26 mm×28 mm×0.7 mm) on which an anode made of ITO (indium tin oxide) with a thickness of 50 nm was formed, 5×10 -4 Each thin film is stacked at a vacuum degree of 1.5 Pa.

[0664] First, NPD was evaporated on ITO in a film thickness of 40 nm, and TcTa was evaporated thereon in a film thickness of 15 nm to form a hole injection and transport layer comprising two layers. Next, mCP was evaporated in a film thickness of 15 nm to form an electron blocking layer. Next, a compound (BO2-0511S) as a main body, Cz-TRZ3 as an auxiliary dopant, and a compound (ED1) as a light-emitting dopant were co-evaporated from different evaporation sources to form a light-emitting layer with a film thickness of 20 nm. At this time, the weight ratio of the main body, the auxiliary dopant, and the light-emitting dopant was set to 90:9:1. Next, 2CzBN was evaporated in a film thickness of 10 nm to form an electron transport layer, and TSPO1 was evaporated thereon in a film thickness of 20 nm to form an electron transport layer (second electron transport layer). Next, LiF was evaporated in a film thickness of 1 nm, and aluminum was evaporated thereon in a film thickness of 100 nm to form a cathode, thereby obtaining an organic EL element (element 1).

[0665] The prepared element 1 was measured at 1000 cd / m 2 The luminescence spectrum, chromaticity and external quantum efficiency during luminescence. As a result, a luminescence peak with a maximum wavelength of 470nm and a half-value width of 18nm was observed in the luminescence spectrum, and deep blue luminescence was observed. In addition, 1000cd / m 2 The external quantum efficiency during light emission was 20.7%, and a high quantum efficiency was obtained.

[0666] <Comparative Example 1>

[0667] Preparation and evaluation of comparative element 1 using mCBP as a host compound, compound (Cz-TRZ3) as an auxiliary dopant, and compound (ED1) as a light-emitting dopant

[0668] An EL element (Comparative element 1) was obtained by the same steps and configuration as in Example 1, except that the compound (mCBP) was used as a host instead of the compound (BO2-0511S).

[0669] The prepared comparative element 1 was measured at 1000 cd / m 2 The luminescence spectrum, chromaticity and external quantum efficiency of the luminescent device were measured. As a result, a luminescence peak with a maximum wavelength of 471 nm and a half-value width of 18 nm was observed in the luminescence spectrum, and deep blue luminescence was observed. However, 1000 cd / m 2 The external quantum efficiency during light emission was 14.8%, which was lower than that of Example 1.

[0670]

[0671]

[0672] Description of Reference Numerals

[0673] 100 Organic electroluminescent elements

[0674] 101 substrate

[0675] 102 Anode

[0676] 103 Hole injection layer

[0677] 104 hole transport layer

[0678] 105 Luminous Layer

[0679] 106 Electron transport layer

[0680] 107 Electron injection layer

[0681] 108 cathode

Claims

1. An organic electroluminescent element having a light-emitting layer, wherein: A host compound having a boron atom and an oxygen atom in a molecule is included as a first component; A thermally activated delayed phosphor having a difference ΔEST between an excited singlet energy level and an excited triplet energy level of 0.20 eV or less is included as a second component; As a third component, a fluorescent substance is included. The phosphor as the third component is a compound having a structure represented by the following formula (ED21), (ED22), (ED23), (ED24), (ED25), (ED26), (ED27), (ED211), (ED212), (ED221), (ED222), (ED223), (ED231), (ED241), (ED242), (ED261) or (ED271), in, In the above formulas, The hydrogen is each independently optionally substituted by an aryl, heteroaryl, diarylamino, diheteroarylamino, arylheteroarylamino, alkyl, cycloalkyl, alkoxy or aryloxy group, and the hydrogen in the aryl, heteroaryl, diarylamino, diheteroarylamino, arylheteroarylamino, alkyl, cycloalkyl, alkoxy or aryloxy group is optionally further substituted by at least one selected from the group consisting of an aryl, heteroaryl and alkyl group.

2. The organic electroluminescent element according to claim 1, wherein The light-emitting layer contains, as the first component, at least one compound represented by any of the following formulae (i), (ii) and (iii), In the above formula (i), Ring A, Ring B and Ring C are each independently an aromatic ring or a heteroaromatic ring, at least one hydrogen in these rings is optionally substituted, and at least one hydrogen in the compound or structure represented by formula (i) is optionally substituted by cyano, halogen or deuterium; In the above formula (ii), Ring A, Ring B and Ring C are each independently an aromatic ring or a heteroaromatic ring, and at least one hydrogen atom in these rings is optionally substituted. Y 1 For B, X 1 , X 2 and X 3 Each independently represents -O-, -N(R)-, -C(R)2- or -S-, X 1 ~X 3 At least two of them are -O-, the R of -N(R)- and the R of -C(R)2- are optionally substituted aryl, optionally substituted heteroaryl or alkyl, and the R of -N(R)- is optionally bonded to at least one of the A ring, the B ring and the C ring via a linking group or a single bond; and At least one hydrogen in the compound or structure represented by formula (ii) is optionally replaced by cyano, halogen or deuterium; In the above formula (iii), Ring A, Ring B, Ring C and Ring D are each independently an aromatic ring or a heteroaromatic ring, and at least one hydrogen atom in these rings is optionally substituted. R 1 and R 2 Each is independently hydrogen, an alkyl group having 1 to 6 carbon atoms, an aryl group having 6 to 12 carbon atoms, a heteroaryl group having 2 to 15 carbon atoms, a diarylamino group, a diheteroarylamino group or an arylheteroarylamino group, wherein the aryl group in the diarylamino group is an aryl group having 6 to 12 carbon atoms, the heteroaryl group in the diheteroarylamino group is a heteroaryl group having 2 to 15 carbon atoms, the aryl group in the arylheteroarylamino group is an aryl group having 6 to 12 carbon atoms, and the heteroaryl group is a heteroaryl group having 2 to 15 carbon atoms, and At least one hydrogen atom in the compound represented by formula (iii) may be substituted by cyano, halogen or deuterium.

3. The organic electroluminescent element according to claim 1 or 2, wherein: The light-emitting layer includes, as the first component, at least one compound represented by any of the following formulae (1), (2) and (3), In the above formula (1), R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , R 8 , R 9 , R 10 and R 11 are each independently hydrogen, aryl, heteroaryl, diarylamino, diheteroarylamino, arylheteroarylamino, alkyl, cycloalkyl, alkoxy or aryloxy, wherein the hydrogen in the aryl, heteroaryl, diarylamino, diheteroarylamino, arylheteroarylamino, alkyl, cycloalkyl, alkoxy or aryloxy is optionally further substituted by at least one selected from aryl, heteroaryl and alkyl, At least one hydrogen atom in the compound or structure represented by formula (1) is optionally replaced by cyano, halogen or deuterium. In the above formula (2), R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 9 , R 10 and R 11 are each independently hydrogen, aryl, heteroaryl, diarylamino, diheteroarylamino, arylheteroarylamino, alkyl, cycloalkyl, alkoxy or aryloxy, wherein the hydrogen in the aryl, heteroaryl, diarylamino, diheteroarylamino, arylheteroarylamino, alkyl, cycloalkyl, alkoxy or aryloxy is optionally further substituted by at least one selected from aryl, heteroaryl and alkyl, X 1 , X 2 and X 3 Each independently represents -O-, -N(R)-, -S- or -C(R)2-, X 1 , X 2 and X 3 At least two of the -N(R)- and -C(R)2- are -O-, the R of the -N(R)- and the R of the -C(R)2- are aryl, heteroaryl or alkyl, and the hydrogen in the aryl, heteroaryl or alkyl is optionally further substituted by at least one selected from aryl, heteroaryl and alkyl, and At least one hydrogen in the compound and structure represented by formula (2) is optionally replaced by cyano, halogen or deuterium; In the above formula (3), R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , R 8 , R 9 , R 10 , R 11 , R 12 , R 13 and R 14 are each independently hydrogen, aryl, heteroaryl, diarylamino, diheteroarylamino, arylheteroarylamino, alkyl, cycloalkyl, alkoxy, aryloxy, heteroaryloxy, arylthio, heteroarylthio or alkyl-substituted silyl, at least one hydrogen in the aryl, heteroaryl, diarylamino, diheteroarylamino, arylheteroarylamino, alkyl, cycloalkyl, alkoxy, aryloxy, heteroaryloxy, arylthio, heteroarylthio or alkyl-substituted silyl is optionally substituted with aryl, heteroaryl or alkyl, and R 5 ~R 7 and R 10 ~R 12 The adjacent groups are optionally bonded to each other and together with the b ring or the d ring form an aromatic ring or a heteroaromatic ring, and at least one hydrogen in the formed ring is optionally substituted by an aryl, heteroaryl, diarylamino, diheteroarylamino, arylheteroarylamino, alkyl, cycloalkyl, alkoxy, aryloxy, heteroaryloxy, arylthio, heteroarylthio or alkyl-substituted silyl group, and at least one hydrogen in the aryl, heteroaryl, diarylamino, diheteroarylamino, arylheteroarylamino, alkyl, cycloalkyl, alkoxy, aryloxy, heteroaryloxy, arylthio, heteroarylthio or alkyl-substituted silyl group is optionally substituted by an aryl, heteroaryl or alkyl group, and At least one hydrogen atom in the compound represented by formula (3) may be substituted by cyano, halogen or deuterium.

4. The organic electroluminescent element according to claim 1 or 2, wherein: The host compound as the first component is a compound having a structure represented by the following formula (1-1), (2-1), (2-2) or (3-1), In the above formulas, The hydrogen is each independently optionally substituted by an aryl, heteroaryl, diarylamino, diheteroarylamino, arylheteroarylamino, alkyl, cycloalkyl, alkoxy or aryloxy group, and the hydrogen in the aryl, heteroaryl, diarylamino, diheteroarylamino, arylheteroarylamino, alkyl, cycloalkyl, alkoxy or aryloxy group is optionally further substituted by at least one selected from the group consisting of an aryl, heteroaryl and alkyl group.

5. The organic electroluminescent element according to claim 3, wherein The compound represented by any of the formulae (1) to (3) comprises at least one structure selected from the following partial structure group A, Partial structure group A: In the above partial structural formula, Me represents a methyl group, and the wavy line represents the bonding position. Wherein, the hydrogen in the above-mentioned partial structural formulas is independently optionally substituted by aryl, heteroaryl, diarylamino, diheteroarylamino, arylheteroarylamino, alkyl, alkoxy or aryloxy; the hydrogen in the aryl is optionally further substituted by aryl, heteroaryl or alkyl; the hydrogen in the heteroaryl is optionally further substituted by aryl, heteroaryl or alkyl; the hydrogen in the diarylamino, diheteroarylamino and arylheteroarylamino is optionally further substituted by aryl, heteroaryl or alkyl.

6. The organic electroluminescent element according to claim 1 or 2, wherein: The first component, the second component, and the third component satisfy at least any one of the following formulas (a) to (c): |Ip(1)|≥|Ip(2)|…Formula (a) In formula (a), Ip(1) represents the ionization potential of the first component, and Ip(2) represents the ionization potential of the second component; |Eg(2)|≥|Eg(3)|…Formula (b) In formula (b), Eg(2) represents the optical band gap of the second component, and Eg(3) represents the optical band gap of the third component; ΔEST(1)≥ΔEST(2)…Formula (c) In formula (c), ΔEST(1) represents the energy difference between the excited singlet level and the excited triplet level of the first component, and ΔEST(2) represents the energy difference between the excited singlet level and the excited triplet level of the second component.

7. The organic electroluminescent element according to claim 1 or 2, wherein: The full width at half maximum (FWHM) of the fluorescence peak of the third component is 35 nm or less.

8. The organic electroluminescent element according to claim 1 or 2, wherein: The second component is a compound having a structure represented by the following formula (AD11), (AD12), (AD13), (AD21) or (AD22), In the above formulas, R 7 or R 8 is an alkyl group having 1 to 6 carbon atoms, The hydrogen is each independently optionally substituted by an aryl, heteroaryl, diarylamino, diheteroarylamino, arylheteroarylamino, alkyl, cycloalkyl, alkoxy or aryloxy group, and the hydrogen in the aryl, heteroaryl, diarylamino, diheteroarylamino, arylheteroarylamino, alkyl, cycloalkyl, alkoxy or aryloxy group is optionally further substituted by at least one selected from the group consisting of an aryl, heteroaryl and alkyl group.

9. The organic electroluminescent element according to claim 1 or 2, wherein: The second component contains at least one compound represented by the following formula (AD31) as the thermally activated delayed phosphor: In the above formula (AD31), M is independently at least one of a single bond, -O-, -N(Ar)- and -C(Ar)2-, wherein Ar in -N(Ar)- and -C(Ar)2- is an aryl group, Q is a group represented by any of the partial structural formulas (Q1) to (Q26), n is an integer from 1 to 5, The hydrogen atoms in the above formula (AD31) are each independently optionally substituted by an aryl group having 6 to 18 carbon atoms, a heteroaryl group having 6 to 18 carbon atoms, an alkyl group having 1 to 6 carbon atoms, or a cycloalkyl group having 3 to 12 carbon atoms, At least one hydrogen atom in the compound represented by the above formula (AD31) is optionally substituted by halogen or deuterium, 10. The organic electroluminescent element according to claim 1 or 2, wherein: The second component includes at least one compound having a structure represented by any one of the following formulae (AD3101) to (AD3118) as the thermally activated delayed phosphor.

11. The organic electroluminescent element according to claim 1 or 2, wherein: The third component further includes, as the phosphor, a compound having at least one structure selected from the following partial structure group B, Partial structure group B: In the above partial structural formula, Me represents a methyl group, t Bu and t-Bu represent tert-butyl groups, and the wavy line indicates the bonding position. Wherein, the hydrogen in the above-mentioned partial structural formulas is independently optionally substituted by aryl, heteroaryl, diarylamino, diheteroarylamino, arylheteroarylamino, alkyl, alkoxy or aryloxy; the hydrogen in the aryl is optionally further substituted by aryl, heteroaryl or alkyl; the hydrogen in the heteroaryl is optionally further substituted by aryl, heteroaryl or alkyl; the hydrogen in the diarylamino, diheteroarylamino and arylheteroarylamino is optionally further substituted by aryl, heteroaryl or alkyl. 12 . A display device comprising the organic electroluminescent element according to claim 1 . 13 . A lighting device comprising the organic electroluminescent element according to claim 1 .

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