Electroluminescent material and organic electroluminescent device

Abstract

The application belongs to the technical field of organic electroluminescence, and provides an electroluminescent material and an organic electroluminescent device, wherein the electroluminescent material comprises a combination of a first compound with a structure shown in formula I and a second compound with a structure shown in formula II. Through the structural design and compounding of the first compound and the second compound, the two compounds are mutually synergistic, the electroluminescent material is endowed with higher carrier transport performance, the transport balance of carriers can be effectively realized, and the exciton quenching caused by pi-pi stacking is inhibited, so that the organic electroluminescent device using the same has a significantly improved service life and current efficiency, the working voltage is effectively reduced, and the luminous performance of the device is comprehensively improved.

Description

Technical Field

[0001] This invention belongs to the field of organic electroluminescence technology, specifically relating to an electroluminescent material and an organic electroluminescent device. Background Technology

[0002] In recent years, optoelectronic devices based on organic materials have become increasingly popular. The inherent flexibility of organic materials makes them ideal for fabrication on flexible substrates, allowing for the design and production of aesthetically pleasing and stylish optoelectronic products, offering unparalleled advantages over inorganic materials. Examples of such organic optoelectronic devices include organic light-emitting diodes (OLEDs), organic field-effect transistors, organic photovoltaic cells, and organic sensors; among them, OLEDs have seen particularly rapid development and have already achieved commercial success in the field of information display. OLEDs can provide highly saturated red, green, and blue colors, and full-color displays made with them do not require an additional backlight, offering advantages such as vibrant colors, thinness, and flexibility.

[0003] The core of an OLED device is a thin-film structure containing various organic functional materials. Common organic functional materials include: hole injection materials, hole transport materials, hole blocking materials, electron injection materials, electron transport materials, electron blocking materials, light-emitting host materials, and light-emitting guest materials (dyes). When the device is powered on, electrons and holes are injected and transported to the light-emitting region, where they recombine, thereby generating excitons and emitting light.

[0004] Currently, various organic materials have been developed and combined with different device structures to improve carrier mobility, regulate carrier balance, break through electroluminescence efficiency, and delay device decay. According to the light-emitting mechanism, OLED devices can be mainly divided into fluorescence, phosphorescence, thermally excited delayed fluorescence, and thermally excited sensitized fluorescence. For quantum mechanical reasons, common fluorescent emitters mainly utilize singlet excitons generated when electrons and holes combine to emit light, and are still widely used in various OLED products. Some metal complexes (such as iridium complexes) can simultaneously utilize triplet and singlet excitons to emit light, and are called phosphorescent emitters, whose energy conversion efficiency can be up to 4 times higher than that of traditional fluorescent emitters. Thermally excited delayed fluorescence (TADF) technology promotes the transition of triplet excitons to singlet excitons, and can still effectively utilize triplet excitons to achieve high luminescence efficiency without the use of metal complexes. Thermally excited sensitized fluorescence (TASF) technology uses materials with TADF properties to sensitize the emitter through energy transfer, and can also achieve high luminescence efficiency.

[0005] As OLED products gradually enter the market, people have increasingly higher requirements for their performance. Current OLED materials and device structures cannot fully address issues related to efficiency, lifespan, cost, and thermal stability. Therefore, there is an urgent need in this field to develop more diverse and higher-performance organic materials to further improve the luminescent performance of devices. Summary of the Invention

[0006] To address the aforementioned technical problems, the present invention aims to provide an electroluminescent material and an organic electroluminescent device. Through the structural design of the first compound and the second compound and their mutual compounding, the electroluminescent material effectively achieves balanced carrier transport and reduces exciton quenching caused by π-π stacking. This results in a significantly improved lifespan and luminous efficiency for the organic electroluminescent device, while simultaneously reducing voltage and achieving a comprehensive improvement in the device's luminous performance.

[0007] To achieve this objective, the present invention adopts the following technical solution:

[0008] In a first aspect, the present invention provides an electroluminescent material comprising a combination of a first compound and a second compound.

[0009] The first compound has the structure shown in Formula I:

[0010] Formula I.

[0011] In this invention, Formula I means (Aromatic amine structure) can be attached to a benzotriphenyl fused ring. Any chemically permissible site on the benzotriphenyl ring; it is understood that, in addition to the aromatic amine structure, the benzotriphenyl ring may optionally be connected to substituents R1, R2, and R3, the number of which is represented by m1, m2, and m3, respectively, and 0 ≤ m1 + m2 + m3 ≤ 13.

[0012] In Formula I, Ar1 and Ar2 are each independently selected from any one of substituted or unsubstituted C6-C30 aryl groups and substituted or unsubstituted C3-C30 heteroaryl groups.

[0013] In Formula I, R1, R2, and R3 are each independently -L'-R'. It should be noted that each L' and each R' in R1, R2, and R3 can be the same or different groups; and if there are multiple (≥2) R1s, then the L's in the multiple R1s can be the same or different, and the R's can be the same or different; the same applies to R2 and R3, which will not be elaborated further.

[0014] L1, L2, L3, and L' are each independently selected from any one of single bonds, substituted or unsubstituted C6-C30 arylene, or substituted or unsubstituted C3-C30 heteroarylene. When L1 is a single bond, it means that the structures at both ends (Ar1 and N atoms) are directly connected by a single bond. Similarly, L2, L3, and L' are not described in detail for the sake of brevity.

[0015] R' is independently selected from deuterium, halogen, cyano, substituted or unsubstituted C1-C30 straight-chain or branched alkyl, substituted or unsubstituted C6-C30 aryl, substituted or unsubstituted C3-C30 heteroaryl, substituted or unsubstituted C3-C30 cycloalkyl, substituted or unsubstituted C2-C30 alkenyl, substituted or unsubstituted C1-C30 alkoxy, substituted or unsubstituted tri(C1-C30 alkyl)silyl, substituted or unsubstituted di(C1-C30 alkyl)(C6-C30 aryl)silyl, substituted or unsubstituted (C1-C30 alkyl)di(C6-C30 aryl)silyl, substituted or unsubstituted tri(C6-C30 aryl)silyl, substituted or unsubstituted C1-C30 alkyl The amino group comprises any one of the following: alkyl amino, substituted or unsubstituted C2-C30 alkenyl amino, substituted or unsubstituted (C1-C30 alkyl)(C2-C30 alkenyl)amino, substituted or unsubstituted C6-C30 aryl amino, substituted or unsubstituted (C1-C30 alkyl)(C6-C30 aryl)amino, substituted or unsubstituted C3-C30 heteroaryl amino, substituted or unsubstituted (C1-C30 alkyl)(C3-C30 heteroaryl)amino, substituted or unsubstituted (C2-C30 alkenyl)(C6-C30 aryl)amino, substituted or unsubstituted (C2-C30 alkenyl)(C3-C30 heteroaryl)amino, and substituted or unsubstituted (C6-C30 aryl)(C3-C30 heteroaryl)amino.

[0016] At least two adjacent groups among R1, R2, R3, and R' are not connected or are linked by chemical bonds to form a ring.

[0017] In this invention, "at least two adjacent groups among R1, R2, R3, and R' are not connected" means that the group is only connected to the C atom through a single bond; "at least two adjacent groups among R1, R2, R3, and R' are connected to form a ring through chemical bonds" means that in addition to being connected to the C atom through chemical bonds, adjacent groups are also connected through chemical bonds, thereby forming a fused ring structure. The same descriptions used below have the same meaning and will not be repeated hereafter.

[0018] In Formula I, m1, m2, and m3 represent the number of substituents R1, R2, and R3, respectively. m1 and m2 are each independently selected from integers from 0 to 4, for example, they can be 0, 1, 2, 3, or 4; m3 is selected from integers from 0 to 6, for example, they can be 0, 1, 2, 3, 4, 5, or 6; and m1 + m2 + m3 ≤ 13.

[0019] It should be noted that when m1 ≥ 2, multiple (at least 2) R1s are the same or different groups. When m1 is 0, it indicates that there are no other substituents on the corresponding benzene ring, and in this case, all three or four sites on the benzene ring are hydrogen. The expressions for m2 and m3 are similar, and for the sake of brevity, they will not be repeated. Similar descriptions in the following text have similar meanings.

[0020] The second compound has the structure shown in Formula II:

[0021] Formula II.

[0022] In Formula II, L4, L5, L6, and L7 are each independently selected from any one of single bonds, substituted or unsubstituted C6-C30 arylene groups, and substituted or unsubstituted C3-C30 heteroarylene groups.

[0023] In Formula II, Ar4, Ar5, and Ar6 are each independently selected from any one of substituted or unsubstituted C6-C30 aryl groups or substituted or unsubstituted C3-C30 heteroaryl groups.

[0024] The substituents in Ar1, Ar2, L1, L2, L3, L', R', L4, L5, L6, L7, Ar4, Ar5, and Ar6 are each independently selected from deuterium, halogen, cyano, C1-C30 straight-chain or branched alkyl, C6-C30 aryl, C3-C30 heteroaryl, C3-C30 cycloalkyl, C2-C30 alkenyl, C1-C30 alkoxy, tri(C1-C30 alkyl)silyl, di(C1-C30 alkyl)(C6-C30 aryl)silyl, (C1-C30 alkyl)di(C6-C30 aryl)silyl, tri(C6-C30 aryl)silyl, C1-C30 alkylamino, The substituent is selected from the following: C2-C30 alkenylamino, (C1-C30 alkyl)(C2-C30 alkenyl)amino, C6-C30 arylamino, (C1-C30 alkyl)(C6-C30 aryl)amino, C3-C30 heteroarylamino, (C1-C30 alkyl)(C3-C30 heteroaryl)amino, (C2-C30 alkenyl)(C6-C30 aryl)amino, (C2-C30 alkenyl)(C3-C30 heteroaryl)amino, and (C6-C30 aryl)(C3-C30 heteroaryl)amino; the substituent may optionally be substituted with deuterium; at least two adjacent groups in the substituent are not connected or are linked by chemical bonds to form a ring.

[0025] In the present invention, the "substituted or unsubstituted" group may be substituted with one substituent or multiple substituents. When there are multiple substituents (at least two), they may be the same or different substituents; when the same expression is involved hereinafter, it shall have the same meaning. Unless otherwise specified, the selection range of the substituents in the first compound shown in Formula I and the second compound shown in Formula II is as described above, and will not be elaborated herein.

[0026] Any hydrogen in the first compound may be optionally substituted with deuterium, and any hydrogen in the second compound may be optionally substituted with deuterium.

[0027] In the present invention, the first compound is as shown in Formula I, which has an aromatic amine structure, and a helical benzo[ghi]perylene-fused aromatic hydrocarbon structure is connected to the aromatic amine. While having a relatively high hole mobility, it reduces exciton quenching caused by π-π stacking, which helps the device to have higher efficiency and lower voltage. The second compound is as shown in Formula II, and its structure contains an electron-withdrawing triazine structure, and a naphthalene structure substituted with a specific group is connected to the triazine structure. Through the structural design and compounding of the first compound and the second compound, the two work synergistically to make the electroluminescent material have excellent carrier transport performance, effectively achieve carrier transport balance, and the introduction of the naphthalene structure with a substituted group in the second compound effectively adjusts the triplet energy level of the material, reduces the energy level difference between the host and the guest, promotes the efficient host-guest energy transfer efficiency, makes the organic electroluminescent device using it have significantly improved current efficiency and service life, and effectively reduces the operating voltage of the device, comprehensively improving the luminescence performance.

[0028] It should be noted that for the convenience of description in the present invention, the possible functions of each group / feature of the first compound and the second compound are described separately, but this does not mean that these groups / features act independently. In fact, the reason for obtaining good performance is essentially the optimized design of the entire molecular structure, which is the result of the synergistic effect between each group and the two types of compounds, rather than the effect of a single group.

[0029] The following are the preferred technical solutions of the present invention, but do not limit the technical solutions provided by the present invention. Through the following preferred technical solutions, the objectives and beneficial effects of the present invention can be better achieved.

[0030] In the present invention, for the description of chemical elements, unless otherwise specified, the concept of isotopes with the same chemical properties is included. For example, hydrogen (H) includes 1 H (protium), 2 H (deuterium, D), 3 H (tritium, T), etc.; carbon (C) includes12 C 13 C, etc.

[0031] In this invention, hydrogen at any site in the first compound is optionally substituted with deuterium, and hydrogen at any site in the second compound is optionally substituted with deuterium.

[0032] In this invention, the halogen can be fluorine, chlorine, bromine, or iodine. The same descriptions used below have the same meaning.

[0033] In this invention, unless otherwise specified, the heteroatom of the heteroaryl group is selected from N, O, S, P, B, Si, or Se, preferably N, O, or S. The heteroatom of the heterocycloalkyl group is selected from N, O, S, P, B, Si, or Se, preferably N, O, or S.

[0034] In this invention, the way the ring structure is represented by "—" indicates that the connection point is located at any position on the ring structure where bonding can occur.

[0035] In this invention, " Both "" and "*" indicate the linking site of a functional group.

[0036] In this invention, the expression Ca-Cb represents that the group has ab carbon atoms. Unless otherwise specified, the number of carbon atoms does not include the number of carbon atoms of the substituents.

[0037] In this invention, "each independently" means that when there are multiple subjects, they can be the same or different from each other.

[0038] In this invention, C6-C30 can all be C6, C9, C10, C12, C14, C16, C18, C20, C22, C24, C26 or C28, etc.

[0039] C3-C30 can all be C3, C4, C5, C6, C9, C10, C12, C14, C16, C18, C20, C22, C24, C26 or C28, etc.

[0040] C1-C30 can all be C2, C3, C4, C5, C6, C7, C8, C9, C10, C11, C12, C13, C14, C15, C16, C17, C18, C20, C22, C24, C26 or C28, etc.

[0041] C2-C30 can all be C3, C4, C5, C6, C7, C8, C9, C10, C11, C12, C13, C14, C15, C16, C17, C18, C20, C22, C24, C26 or C28, etc.

[0042] In this invention, the C6-C30 aryl group, preferably C6-C20 aryl group, includes monocyclic aryl and fused-ring aryl groups. A monocyclic aryl group refers to a group containing at least one phenyl atom; when containing at least two phenyl atomes, the phenyl atomes are linked by a single bond, exemplarily including but not limited to: phenyl, biphenyl, terphenyl, tetraphenyl, etc. A fused-ring aryl group refers to a group containing at least two aromatic rings, where the aromatic rings share two adjacent carbon atoms fused together, exemplarily including but not limited to: naphthyl (1-naphthyl, 2-naphthyl), anthraceneyl (1-anthrayl, 2-anthrayl, 9-anthrayl), phenanthrene, indene, fluorenyl, and their derivatives (9,9-dimethylfluorenyl, 9,9-diethylfluorenyl, 9,9-dipropylfluorenyl, 9,9-dimethyl ... Examples of aryl groups include 9-dibutylfluorenel, 9,9-dipentylfluorenel, 9,9-dihexylfluorenel, 9,9-diphenylfluorenel, 9,9-dinaphthylfluorenel, phenylmethylfluorenel, spirodifluorenel, benzo[a]fluorenel, etc.), fluoranyl, triphenylene, pyrene (1-pyrene, 2-pyrene, 4-pyrene), peryl, alkyl, triphenylene, and tetraphenyl (1-tetraphenyl, 2-tetraphenyl, 9-tetraphenyl), etc. It should be noted that monocyclic aryl groups and fused-ring aryl groups linked by single bonds also fall under the aryl group category, such as phenylnaphthyl, naphthylphenyl, phenylnaphthylphenyl, and binaphthyl.

[0043] The C3-C30 heteroaryl group, preferably C3-C20 heteroaryl group, includes monocyclic heteroaryl groups or fused-ring heteroaryl groups. A monocyclic heteroaryl group means that the molecule contains at least one heteroaryl group. When the molecule contains one heteroaryl group and other groups (such as aryl, heteroaryl, etc.), the heteroaryl group and other groups are connected by a single bond, exemplarily including but not limited to: pyridyl, pyrimidinyl, pyrazinyl, pyridazinyl, triazinyl, furanyl, thiophene, pyrroleyl, bipyridinyl, phenylpyridinyl, pyridylphenyl, pyrimidinylphenyl, etc. The term "fused-ring heteroaryl" refers to a molecule containing at least one aromatic heterocycle and one aromatic ring (aromatic heterocycle or aromatic ring), and the two share two adjacent atoms fused together in a group, including but not limited to: quinolinyl, isoquinolinyl, quinoxalinyl, quinazolinyl, benzofuranyl, benzothiopheneyl, isobenzofuranyl, isobenzothiopheneyl, indolyl, dibenzofuranyl, dibenzothiopheneyl, naphthobenzofuranyl, naphthobenzothiopheneyl, carbazoleyl and its derivatives (N-phenylcarbazoleyl, N-naphthylcarbazoleyl, benzocarbazoleyl, dibenzocarbazoleyl, indolocarbazoleyl, azacarbazoleyl, etc.), acridineyl, phenothiazinyl, phenotoxazinyl, hydrogenated acridineyl, etc. It should be noted that heteroaryl groups connected by single bonds, as well as aryl groups connected by single bonds, also fall under the category of heteroaryl groups, such as phenyldibenzofuranyl, phenyldibenzothiophenyl, dibenzothiophenylphenyl, dibenzofuranylphenyl, etc.

[0044] Specific examples of the C6-C30 arylene group can be exemplified by removing one hydrogen atom from the aryl group examples above, resulting in a divalent group; specific examples of the C3-C30 heteroarylene group can be exemplified by removing one hydrogen atom from the heteroaryl group examples above, resulting in a divalent group.

[0045] In this invention, a specific example of the C6-C30 arylamino group is a monovalent group obtained by substituting at least one (e.g., one or two) hydrogens in the -NH2 group with the aforementioned aryl group. A specific example of the C3-C30 heteroarylamino group is a monovalent group obtained by substituting at least one (e.g., one or two) hydrogens in the -NH2 group with the aforementioned heteroaryl group. A specific example of the (C6-C30 aryl)(C3-C30 heteroaryl)amino group is a monovalent group obtained by substituting one hydrogen in the -NH2 group with the aforementioned heteroaryl group and one hydrogen with the aforementioned aryl group.

[0046] The C1-C30 straight-chain or branched alkyl group, preferably C1-C16 straight-chain or branched alkyl group, more preferably C1-C10 straight-chain or branched alkyl group, includes, but is not limited to: methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, 2-methylbutyl, n-pentyl, isopentyl, neopentyl, n-hexyl, neohexyl, 2-ethylhexyl, n-octyl, n-heptyl, n-nonyl, n-decyl, etc.

[0047] Specific examples of the C1-C30 alkoxy groups can be exemplified by the monovalent groups obtained by connecting the above-mentioned straight-chain or branched alkyl groups to O.

[0048] A specific example of the C1-C30 alkylamino group is a monovalent group formed by replacing at least one (e.g., one or two) hydrogen atoms in -NH2 with the aforementioned straight-chain or branched alkyl groups.

[0049] The C2-C30 alkenyl group, preferably C2-C10 alkenyl group, contains at least one C=C, and includes, but is not limited to: vinyl, propenyl, allyl, butenyl, pentenyl, hexenyl, heptenyl, octenyl, nonenyl, decenyl, butadienyl, pentadienyl, etc.

[0050] Specific examples of the C2-C30 alkenylamino group are monovalent groups obtained by substituting at least one (e.g., one or two) hydrogen atoms in the -NH2 group with the alkenyl group. Specific examples of the (C1-C30 alkyl)(C2-C30 alkenyl)amino group are monovalent groups obtained by substituting one hydrogen atom in the -NH2 group with the alkenyl group and another hydrogen atom with the straight-chain or branched alkyl group. Specific examples of the (C1-C30 alkyl)(C6-C30 aryl)amino group are monovalent groups obtained by substituting one hydrogen atom in the -NH2 group with the aryl group and another hydrogen atom with the straight-chain or branched alkyl group. Specific examples of the (C1-C30 alkyl)(C3-C30 heteroaryl)amino group are monovalent groups obtained by substituting one hydrogen atom in the -NH2 group with the heteroaryl group and another hydrogen atom with the straight-chain or branched alkyl group. A specific example of the (C2-C30 alkenyl)(C6-C30 aryl)amino group is a monovalent group obtained by substituting one hydrogen atom in -NH2 with the aforementioned aryl group and one hydrogen atom with the aforementioned alkenyl group. A specific example of the (C2-C30 alkenyl)(C3-C30 heteroaryl)amino group is a monovalent group obtained by substituting one hydrogen atom in -NH2 with the aforementioned heteroaryl group and one hydrogen atom with the aforementioned alkenyl group.

[0051] The C3-C30 cycloalkyl group, preferably C3-C10 cycloalkyl group, includes monocycloalkyl or polycycloalkyl groups. Monocycloalkyl refers to an alkyl group containing a single ring structure, while polycycloalkyl refers to a structure formed by two or more cycloalkyl groups sharing one or more carbon atoms on a ring; exemplary examples include, but are not limited to, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, and adamantyl.

[0052] Specific examples of the C2-C30 heterocyclic alkyl group can be exemplified by a monovalent group formed by replacing one of the ring carbon atoms in the aforementioned cycloalkyl group with a heteroatom. The heteroatom is preferably N, O, or S, and includes, but is not limited to, epoxy group, oxetane group, tetrahydrofuranyl group, tetrahydrothiophenyl group, tetrahydropyrroleyl group, tetrahydropyranyl group, piperidinyl group, piperazineyl group, dioxaneyl group, morpholinyl group, etc.

[0053] Specific examples of the tri(C1-C30 alkyl)silyl group are monovalent groups formed by the independent substitution of each of the three hydrogens in -SiH3 with the aforementioned straight-chain or branched alkyl groups. Specific examples of the di(C1-C30 alkyl)(C6-C30 aryl)silyl group are monovalent groups formed by the independent substitution of each of the two hydrogens in -SiH3 with the aforementioned straight-chain or branched alkyl groups and the substitution of one hydrogen with the aforementioned aryl group. Specific examples of the (C1-C30 alkyl)di(C6-C30 aryl)silyl group are monovalent groups formed by the independent substitution of each of the two hydrogens in -SiH3 with the aforementioned aryl group and the substitution of one hydrogen with the aforementioned straight-chain or branched alkyl group. Specific examples of the tri(C6-C30 aryl)silyl group are monovalent groups formed by the independent substitution of each of the three hydrogens in -SiH3 with the aforementioned aryl group.

[0054] As a preferred embodiment of the present invention, the first compound has a structure as shown in any one of formulas IA, IB, and IC:

[0055] ;

[0056] Ar1, Ar2, L1, L2 and L3 have the same range of definition as in Equation I.

[0057] Preferably, the first compound has the structure shown in any one of the following:

[0058] ;

[0059] Ar1, Ar2, L1, L2 and L3 have the same range of definition as in Equation I.

[0060] As a preferred embodiment of the present invention, the Ar2 is selected from any one of substituted or unsubstituted C6-C20 (e.g., C6, C9, C10, C12, C13, C14, C15, C16 or C18, etc.) aryl groups and substituted or unsubstituted C10-C20 (e.g., C11, C12, C14, C15, C16 or C18, etc.) heteroaryl groups.

[0061] Preferably, the Ar2 is selected from any one of the following groups, whether substituted or unsubstituted:

[0062] ;

[0063] in, The linking site of the representative group.

[0064] X1 is selected from O, S, NR 11 or CR 12 R 13 Any one of them.

[0065] R 11 R 12 R 13 Each group is independently selected from any one or a combination of at least two of the following unsubstituted or deuterated groups: C1-C30 straight-chain or branched alkyl, C6-C30 aryl, C3-C30 heteroaryl, C2-C30 alkenyl; The R 12 and R 13 They can be either not connected or linked together by chemical bonds to form a ring.

[0066] Preferably, the R 11 R12 R 13 Each group is independently selected from any one or at least two combinations of the following unsubstituted or deuterated groups: C1-C10 (e.g., C2, C3, C4, C5, C6, C7, C8, C9, etc.) straight-chain or branched alkyl, C2-C10 (e.g., C3, C4, C5, C6, C7, C8, C9, etc.) alkenyl, C6-C20 (e.g., C6, C9, C10, C12, C14, C15, C16, or C18, etc.) aryl, and more preferably any one of the following unsubstituted or deuterated groups: C1-C6 straight-chain or branched alkyl, phenyl, naphthyl, biphenyl, terphenyl, phenylnaphthyl, naphthylphenyl, and more preferably unsubstituted or deuterated methyl or unsubstituted or deuterated phenyl.

[0067] Preferably, the R 12 and R 13 They can form spirofluorene groups either without bonding or by chemical bonds.

[0068] Preferably, the substituents in Ar2 are selected from any one or a combination of at least two of deuterium, C1-C30 straight-chain or branched alkyl, C6-C30 aryl, and C3-C30 heteroaryl. More preferably, they are selected from any one or a combination of at least two of deuterium, C1-C10 (e.g., C2, C3, C4, C5, C6, C7, C8, C9, etc.) straight-chain or branched alkyl, C6-C20 (e.g., C6, C9, C10, C12, C14, C15, C16, or C18, etc.) aryl, and C3-C20 (e.g., C3, C4, C5, C6, C9, C10, C12, C14, C15, C16, C18, etc.) heteroaryl. More preferably, they are selected from any one of deuterium, phenyl, biphenyl, terphenyl, naphthyl, phenylnaphthyl, naphthylphenyl, and binaphthyl. The aforementioned groups may optionally be substituted with deuterium.

[0069] Preferably, the Ar2 is selected from any one of the following unsubstituted or deuterated groups:

[0070] ;

[0071] in, The linking site of the representative group.

[0072] More preferably, the Ar2 is selected from any one of the following unsubstituted or deuterated groups:

[0073] .

[0074] In the aforementioned structure, R A1Each group is independently selected from any one or a combination of at least two of the following unsubstituted or deuterated groups: C6-C20 (e.g., C6, C9, C10, C12, C14, C15, C16, C18, etc.) aryl, C3-C20 (e.g., C3, C4, C5, C6, C9, C10, C12, C14, C15, C16, C18, etc.) heteroaryl, preferably any one of the following unsubstituted or deuterated groups:

[0075] .

[0076] As a preferred embodiment of the present invention, the Ar1 is selected from any one of substituted or unsubstituted C6-C20 (e.g., C6, C9, C10, C12, C13, C14, C15, C16 or C18, etc.) aryl groups and substituted or unsubstituted C3-C20 (e.g., C3, C4, C5, C6, C9, C10, C11, C12, C14, C15, C16 or C18, etc.) heteroaryl groups.

[0077] Preferably, the Ar1 is selected from any one of the following groups, whether substituted or unsubstituted:

[0078] ;

[0079] in, The linking site of the representative group.

[0080] As a preferred embodiment of the present invention, L1, L2, and L3 are each independently selected from any one of single-bonded, substituted or unsubstituted C6-C20 (e.g., C6, C9, C10, C12, C13, C14, C15, C16, or C18, etc.) arylene, and substituted or unsubstituted C5-C20 (e.g., C6, C7, C8, C9, C10, C12, C14, C15, C16, or C18, etc.) heteroarylene.

[0081] Preferably, L1, L2, and L3 are each independently selected from any one of the following groups: single bond, substituted, or unsubstituted:

[0082] ;

[0083] in, The linking site of the representative group.

[0084] In a preferred embodiment, the first compound has a structure as shown in any of the following:

[0085] .

[0086] In the aforementioned compound structures, the number in the upper right corner of the square brackets indicates the number of D atoms in the molecular structure. Taking A141 as an example, "D1-31" means that 1-31 H atoms in the molecular structure are replaced by D atoms. Other similar expressions in this article are similar and will not be repeated one by one.

[0087] As a preferred embodiment of the present invention, in the second compound represented by Formula II, Ar5 is selected from any one of substituted or unsubstituted C6-C20 (e.g., C6, C9, C10, C12, C13, C14, C15, C16 or C18, etc.) aryl groups, substituted or unsubstituted C10-C20 (e.g., C11, C12, C14, C15, C16 or C18, etc.) heteroaryl groups, preferably any one of the following groups: phenyl, naphthyl, biphenyl, dibenzofuranyl, dibenzothiopheneyl.

[0088] As a preferred embodiment of the present invention, L5 is selected from any one of single-bonded, substituted or unsubstituted C6-C20 (e.g., C6, C9, C10, C12, C13, C14, C15, C16 or C18, etc.) arylene, substituted or unsubstituted C5-C20 (e.g., C6, C7, C8, C9, C10, C12, C14, C15, C16 or C18, etc.) heteroarylene, preferably single-bonded.

[0089] As a preferred embodiment of the present invention, the second compound has a structure as shown in Formula II-A or Formula II-B:

[0090] ;

[0091] Among them, L4, L6, L7, Ar4 and Ar6 have the same range of definition as in Equation II.

[0092] X2 is either O or S.

[0093] R4 and R5 are each independently selected from any one of deuterium, halogen, cyano, C1-C30 straight-chain or branched alkyl, C6-C30 aryl, C3-C30 heteroaryl, C3-C30 cycloalkyl, C1-C30 alkoxy, C2-C30 alkenyl, C6-C30 arylamino, and C3-C30 heteroarylamino, and the aforementioned groups may optionally be substituted with deuterium; at least two adjacent groups in R4 and R5 are not connected or are linked by chemical bonds to form a ring.

[0094] n1 is selected from integers from 0 to 3, for example, it can be 0, 1, 2 or 3; n2 is selected from integers from 0 to 4, for example, it can be 0, 1, 2, 3 or 4; n3 is selected from integers from 0 to 5, for example, it can be 0, 1, 2, 3, 4 or 5.

[0095] As a preferred embodiment of the present invention, L7 is selected from any one of single-bonded, substituted or unsubstituted C6-C20 (e.g., C6, C9, C10, C12, C13, C14, C15, C16 or C18, etc.) arylene, substituted or unsubstituted C5-C20 (e.g., C6, C7, C8, C9, C10, C12, C14, C15, C16 or C18, etc.) heteroarylene, preferably single-bonded.

[0096] As a preferred embodiment of the present invention, the second compound has a structure as shown in formula II-A1 or formula II-B1:

[0097] .

[0098] More preferably, the second compound has the following structure: More preferably, it has the following structure: .

[0099] Preferably, each of R4 and R5 is independently selected from any one of deuterium, C1-C10 (such as C2, C3, C4, C5, C6, C7, C8, C9, etc.) linear or branched alkyl, C6-C20 (such as C6, C9, C10, C12, C14, C15, C16 or C18, etc.) aryl, C3-C20 (such as C3, C4, C5, C6, C9, C10, C12, C14, C15, C16, C18, etc.) heteroaryl, and C2-C10 (such as C3, C4, C5, C6, C7, C8, C9, etc.) alkenyl, and the foregoing groups may be optionally substituted with deuterium.

[0100] More preferably, each of R4 and R5 is independently selected from any one of the following unsubstituted or deuterated groups:

[0101] .

[0102] Wherein, represents the connection site of the group.

[0103] Even more preferably, each of R4 and R5 is independently selected from any one of the following unsubstituted or deuterated groups:

[0104] .

[0105] Preferably, at least two adjacent groups among R4 and R5 are not connected or are connected by a chemical bond to form a ring Cy, and the ring Cy is selected from any one of C6-C20 (such as C6, C9, C10, C12, C14, C15, C16, C18, etc.) alicyclic rings, C6-C20 (such as C6, C9, C10, C12, C14, C15, C16, C18, etc.) aromatic rings, and C3-C20 (such as C3, C4, C5, C6, C9, C10, C12, C14, C15, C16, C18, etc.) heteroaromatic rings, preferably a benzene ring or a naphthalene ring.

[0106] Exemplarily, at least two adjacent groups among R4 and R5 are not connected, or are connected by a chemical bond to form a benzene ring (such as forming any one of the following structures: ), or are connected by a chemical bond to form a naphthalene ring (such as forming any one of the following structures: ); wherein, represents the connection site of the group to the triazine ring.

[0107] As a preferred embodiment of the present invention, L6 is selected from any one of single-bonded, substituted or unsubstituted C6-C20 (e.g., C6, C9, C10, C12, C13, C14, C15, C16 or C18, etc.) arylene groups, and substituted or unsubstituted C5-C20 (e.g., C6, C7, C8, C9, C10, C12, C14, C15, C16 or C18, etc.) heteroarylene groups, preferably any one of single-bonded, substituted or unsubstituted groups from the following: Further optimization of single bonds.

[0108] As a preferred embodiment of the present invention, the Ar6 is selected from any one of substituted or unsubstituted C6-C20 (e.g., C6, C9, C10, C12, C13, C14, C15, C16 or C18, etc.) aryl groups, substituted or unsubstituted C3-C20 (e.g., C3, C4, C5, C6, C9, C10, C12, C14, C15, C16, C18, etc.) heteroaryl groups, preferably substituted or unsubstituted C6-C20 aryl groups, and more preferably any one of the following groups: phenyl, biphenyl, terphenyl, naphthyl, phenylnaphthyl, naphthylphenyl, and binaphthyl.

[0109] Preferably, the Ar6 is selected from any one of the following groups: unsubstituted or deuterated:

[0110] ;

[0111] in, The linking site of the representative group.

[0112] As a preferred embodiment of the present invention, L4 is selected from any one of single-bonded, substituted or unsubstituted C6-C20 (e.g., C6, C9, C10, C12, C13, C14, C15, C16 or C18, etc.) arylene, substituted or unsubstituted C5-C20 (e.g., C6, C7, C8, C9, C10, C12, C14, C15, C16 or C18, etc.) heteroarylene, preferably single-bonded or phenylene, and more preferably single-bonded.

[0113] As a preferred embodiment of the present invention, the group in the second compound for Preferably, L4 is a single bond, and preferably has any of the following structures:

[0114] ;

[0115] in, This represents the connection site between the representative group and L7; it can be understood that when L7 is a single bond, This refers to the connection site between the group and the triazine ring.

[0116] As a preferred embodiment of the present invention, the Ar4 is selected from any one of substituted or unsubstituted C6-C20 (e.g., C6, C9, C10, C12, C13, C14, C15, C16 or C18, etc.) aryl groups, substituted or unsubstituted C3-C20 (e.g., C3, C4, C5, C6, C9, C10, C12, C14, C15, C16, C18, etc.) heteroaryl groups, preferably any one of the following groups: phenyl, biphenyl, terphenyl, naphthyl, phenylnaphthyl, naphthylphenyl, binaphthyl, dibenzofuranyl, dibenzothiophene.

[0117] Preferably, the Ar4 is selected from any one of the following groups: unsubstituted or deuterated:

[0118] ;

[0119] in, The linking site of the representative group.

[0120] In a preferred embodiment, the second compound has a structure as shown in any of the following:

[0121] .

[0122] As a preferred embodiment of the present invention, the mass ratio of the first compound to the second compound is (0.1-2):1, for example, it can be 0.2:1, 0.3:1, 0.4:1, 0.5:1, 0.6:1, 0.7:1, 0.8:1, 0.9:1, 1:1, 1.1:1, 1.2:1, 1.3:1, 1.4:1, 1.5:1, 1.6:1, 1.7:1, 1.8:1, 1.9:1, etc., preferably (0.4-1.5):1.

[0123] In a second aspect, the present invention provides an application of the electroluminescent material as described in the first aspect, wherein the electroluminescent material is applied to an organic electronic device.

[0124] Preferably, the organic electronic device includes an organic electroluminescent device, an optical sensor, a solar cell, a lighting element, an organic thin-film transistor, an organic field-effect transistor, an organic thin-film solar cell, an information tag, an electronic artificial skin sheet, a sheet-type scanner, or electronic paper.

[0125] Preferably, the electroluminescent material is used in an organic electroluminescent device.

[0126] Preferably, the electroluminescent material is used as the light-emitting layer material in an organic electroluminescent device.

[0127] Preferably, the electroluminescent material serves as the host material for the light-emitting layer in an organic electroluminescent device.

[0128] Thirdly, the present invention provides an organic electroluminescent device, the organic electroluminescent device comprising a first electrode, a second electrode, and an organic layer disposed between the first electrode and the second electrode, the organic layer comprising the electroluminescent material as described in the first aspect.

[0129] As a preferred embodiment of the present invention, the organic layer includes a light-emitting layer, wherein the light-emitting layer includes the electroluminescent material as described in the first aspect.

[0130] Preferably, the thickness of the light-emitting layer is 10-60 nm, for example, it can be 12 nm, 15 nm, 18 nm, 20 nm, 22 nm, 25 nm, 28 nm, 30 nm, 32 nm, 35 nm, 38 nm, 40 nm, 42 nm, 45 nm, 48 nm, 50 nm, 52 nm, 55 nm or 58 nm, more preferably 20-50 nm, and more preferably 30-45 nm.

[0131] Preferably, the electroluminescent material is used as the main material of the light-emitting layer.

[0132] Preferably, the light-emitting layer further includes a dopant material.

[0133] In this invention, the term "doped material" is also known as "dye", "luminescent dye", or "guest material".

[0134] Preferably, the doping material is a phosphorescent doping material.

[0135] Preferably, the emission wavelength of the doped material is 500-650 nm, for example, it can be 510 nm, 520 nm, 530 nm, 540 nm, 550 nm, 560 nm, 580 nm, 600 nm, 620 nm or 640 nm, and more preferably 500-550 nm.

[0136] Preferably, based on the mass of the electroluminescent material as 100%, the mass of the doped material is 0.1-15%, for example, it can be 0.5%, 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12% or 14%, etc.

[0137] Preferably, the light-emitting layer is prepared by vacuum thermal evaporation.

[0138] Preferably, the vacuum thermal evaporation method includes: premixing a first compound and a second compound to obtain the electroluminescent material; and evaporating the electroluminescent material and the doped material using a dual-source co-evaporation method to obtain the luminescent layer.

[0139] As a preferred technical solution of the present invention, the first compound and the second compound are premixed and then vapor-deposited, which has excellent vapor deposition stability and can make the proportion of the main material change less during the continuous vapor deposition process, thereby ensuring the stability of device performance and further improving the performance consistency in device fabrication.

[0140] Preferably, the organic layer further includes a hole transport region and an electron transport region.

[0141] Preferably, the hole transport region includes any one or a combination of at least two of the following: a hole injection layer, a hole transport layer, and an electron blocking layer.

[0142] Preferably, the electron transport region includes any one or a combination of at least two of the electron injection layer, electron transport layer, and hole blocking layer.

[0143] In a preferred embodiment, the organic electroluminescent device (OLED device) includes a first electrode and a second electrode, and an organic layer located between the electrodes. The organic layer can be further divided into multiple regions, such as a hole transport region, a light-emitting layer, and an electron transport region; the light-emitting layer contains the electroluminescent material provided by this invention.

[0144] In a preferred embodiment, the organic electroluminescent device includes a first electrode, a plurality of light-emitting functional layers (organic layers), and a second electrode arranged sequentially. The organic layers include a hole injection layer, a hole transport layer, an electron blocking layer, a light-emitting layer, a hole blocking layer, an electron transport layer, and an electron injection layer arranged sequentially, with the hole injection layer in contact with the first electrode (anode). The organic layer (preferably the light-emitting layer) comprises the electroluminescent material provided by this invention.

[0145] In a preferred embodiment, a substrate can be used below the first electrode or above the second electrode. The substrate is made of glass or polymer material with excellent mechanical strength, thermal stability, water resistance, and transparency. Furthermore, the substrate used for a display can also contain thin-film transistors (TFTs).

[0146] The first electrode can be formed by sputtering or depositing the material to be used as the first electrode on a substrate. When the first electrode is used as the anode, transparent conductive oxide materials such as indium tin oxide (ITO), indium zinc oxide (IZO), tin dioxide (SnO2), and zinc oxide (ZnO) and any combination thereof can be used. When the first electrode is used as the cathode, metals or alloys such as magnesium (Mg), silver (Ag), aluminum (Al), aluminum-lithium (Al-Li), calcium (Ca), ytterbium (Yb), magnesium-indium (Mg-In), and magnesium-silver (Mg-Ag) and any combination thereof can be used.

[0147] Organic layers can be formed on electrodes using methods such as vacuum thermal evaporation, spin coating, and printing. The compounds used as organic layers can be small organic molecules, large organic molecules, or polymers, as well as combinations thereof.

[0148] The hole transport region is located between the anode and the emissive layer. The hole transport region can be a single-layer hole transport layer (HTL), including single-layer hole transport layers containing only one compound and single-layer hole transport layers containing multiple compounds. Alternatively, the hole transport region can be a multilayer structure including at least one of a hole injection layer (HIL), a hole transport layer (HTL), and an electron blocking layer (EBL); wherein the HIL is located between the anode and the HTL, and the EBL is located between the HTL and the emissive layer.

[0149] The material for the hole transport region may be selected from, but is not limited to, phthalocyanine derivatives such as CuPc, conductive polymers or polymers containing conductive dopants such as polyphenylene ethylene, polyaniline / dodecylbenzenesulfonic acid (Pani / DBSA), poly(3,4-ethylenedioxythiophene) / poly(4-styrenesulfonate) (PEDOT / PSS), polyaniline / camphorsulfonic acid (Pani / CSA), polyaniline / poly(4-styrenesulfonate) (Pani / PSS), aromatic amine derivatives, wherein the aromatic amine derivatives include compounds shown below HT-1 to HT-51; or any combination thereof.

[0150] .

[0151] The hole injection layer is located between the anode and the hole transport layer. The hole injection layer can be a single compound material or a combination of multiple compounds. For example, the hole injection layer can be one or more compounds of HT-1 to HT-51 described above, or one or more compounds of HI-1 to HI-3 described below; it can also be one or more compounds of HT-1 to HT-51 doped with one or more compounds of HI-1 to HI-3 described below.

[0152]

[0153] The light-emitting layer includes a host material (the electroluminescent material provided in this invention) and light-emitting dyes (i.e., dopants) capable of emitting different wavelength spectra. The light-emitting layer can also be a monochromatic light-emitting layer emitting a single color such as red, green, or blue. Multiple monochromatic light-emitting layers of different colors can be arranged in a planar pattern according to pixel design, or they can be stacked together to form a colored light-emitting layer. When different colored light-emitting layers are stacked together, they can be separated from each other or connected to each other. The light-emitting layer can also be a single colored light-emitting layer capable of simultaneously emitting different colors such as red, green, and blue.

[0154] Depending on the technology used, the light-emitting layer material can be phosphorescent photoluminescent material. An OLED device can employ a single light-emitting technology or a combination of different light-emitting technologies. These different light-emitting materials, categorized by technology, can emit light of the same color or different colors.

[0155] In a preferred embodiment of the present invention, the material of the light-emitting layer is a phosphorescent host material, which is an electroluminescent material provided by the present invention, comprising a combination of a first compound (structure shown in Formula I) and a second compound (structure shown in Formula II). The emission wavelength of the phosphorescent doped material is 500-650 nm, preferably 500-550 nm.

[0156] In one aspect of the invention, the light-emitting layer employs phosphorescent photoluminescence technology. The phosphorescent doping material of the light-emitting layer may be selected from, but is not limited to, one or more combinations of GPD-1 to GPD-60 listed below.

[0157]

[0158] ; where D represents deuterium.

[0159] In one aspect of the invention, the light-emitting layer employs phosphorescent photoluminescence technology. The phosphorescent doping material of the light-emitting layer may be selected from, but is not limited to, one or more combinations of RPD-1 to RPD-28 listed below.

[0160] .

[0161] In one aspect of the invention, the light-emitting layer employs phosphorescent photoluminescence technology. The phosphorescent doping material of the light-emitting layer may be selected from, but is not limited to, one or more combinations of YPD-1 to YPD-11 listed below.

[0162] .

[0163] The organic layer may also include an electron transport region between the light-emitting layer and the cathode. The electron transport region can be a single-layer electron transport layer (ETL), including single-layer electron transport layers containing only one compound and single-layer electron transport layers containing multiple compounds. The electron transport region may also be a multilayer structure including at least one of an electron injection layer (EIL), an electron transport layer (ETL), and a hole blocking layer (HBL); wherein the HBL is located between the light-emitting layer and the ETL, and the EIL is located between the cathode and the ETL.

[0164] In one aspect of the present invention, the electron transport layer material may be selected from, but not limited to, one or more combinations of ET-1 to ET-73 listed below.

[0165] .

[0166] In one aspect of the invention, a hole blocking layer (HBL) is located between the electron transport layer and the light-emitting layer. The hole blocking layer may employ one or more compounds of ET-1 to ET-73 described above.

[0167] The device may also include an electron injection layer located between the electron transport layer and the cathode. The electron injection layer material includes, but is not limited to, one or more combinations of the following: LiQ, LiF, NaCl, CsF, Li2O, Cs2CO3, BaO, Na, Li, Ca, Mg, Yb.

[0168] Fourthly, the present invention provides a display device comprising the organic electroluminescent device as described in the third aspect.

[0169] Preferably, the display device includes a display screen or a display panel.

[0170] The present invention also provides an electronic device, which includes the aforementioned display device.

[0171] Compared with the prior art, the present invention has at least the following beneficial effects:

[0172] In the electroluminescent material provided by this invention, through the structural design and compounding of the first and second compounds, the two compounds work synergistically to endow the electroluminescent material with higher carrier transport performance, effectively achieve carrier transport balance, suppress exciton quenching caused by π-π stacking, reduce the energy level difference between the host and guest, improve the energy transfer efficiency between the host and guest, and enable organic electroluminescent devices using it to have significantly improved lifespan and current efficiency, effectively reduce operating voltage, and comprehensively improve the luminescent performance of the device. Detailed Implementation

[0173] To facilitate understanding of the present invention, specific embodiments are provided to further illustrate the technical solution of the present invention. Those skilled in the art should understand that the embodiments are merely illustrative of the present invention and should not be considered as specific limitations thereof.

[0174] In one specific embodiment, the first compound and the second compound can be prepared by methods disclosed in the prior art, such as CN119173497A, CN119490845A, CN108368078C, etc.

[0175] In another specific embodiment, the first compound can be prepared via the following exemplary synthetic route based on the Buckwald reaction:

[0176] ;

[0177] Ar1, Ar2, L1, L2, L3, R1, R2, R3, m1, m2 and m3 have the same definitions as in Formula I; Hal1 is selected from any of the halogen or trifluoromethanesulfonate groups, for example, it can be F, I, Br, Cl, -OS(O)2CF3, preferably Cl, Br or -OS(O)2CF3.

[0178] In another specific embodiment, the second compound can be prepared via the following exemplary synthetic route based on the Suzuki reaction:

[0179]

[0180] Wherein, L4, L5, L6, L7, Ar4, Ar5, and Ar6 have the same definitions as in Formula II; Hal2 and Hal3 are each independently selected from any one of the halogens, for example, F, I, Br, or Cl, preferably Cl or Br. U1 and U2 are each independently selected from any one of the following groups: Coupling reactions I and II are Suzuki reactions. The specific order can be adjusted according to the actual situation. That is, coupling reaction I can be carried out first, followed by coupling reaction II, or coupling reaction II can be carried out first, followed by coupling reaction I.

[0181] The electroluminescent material and organic electroluminescent device containing the present invention will be described in detail below using several embodiments as examples, but the electroluminescent material and organic electroluminescent device containing the present invention are not limited to these embodiments.

[0182] Example 1

[0183] An electroluminescent material comprising a first compound A24 and a second compound M91, wherein the mass ratio of A24 to M91 is 5:5.

[0184] An organic electroluminescent device includes the electroluminescent material provided in this embodiment. The structure of the device includes a substrate (glass substrate), an anode (ITO), a hole injection layer, a hole transport layer, an electron blocking layer, a light-emitting layer, a hole blocking layer, an electron transport layer, an electron injection layer, and a cathode 10, which are stacked sequentially. An external power supply is applied between the anode and the cathode.

[0185] The method for fabricating the organic electroluminescent device is as follows:

[0186] (1) The glass substrate coated with ITO transparent conductive layer was ultrasonically treated in commercial cleaning agent, rinsed in deionized water, ultrasonically degreased in a mixed solvent of acetone / ethanol, baked in a clean environment until the moisture was completely removed, cleaned with ultraviolet light and ozone, and bombarded with low-energy cation beam.

[0187] (2) Place the glass substrate with the anode in the vacuum chamber and evacuate it to <1×10 -5 Pa, a mixture of compound HT-29:HI-1 (97 / 3, w / w) was vacuum-deposited on the above anodic layer as a hole injection layer, and the thickness of the deposited film was 10 nm.

[0188] (3) A 100 nm layer of compound HT-29 was vacuum-deposited on the hole injection layer as a hole transport layer;

[0189] (4) A 60 nm layer of compound HT-41 was vacuum-deposited on the hole transport layer as an electron blocking layer;

[0190] (5) A light-emitting layer of the device is vacuum-deposited on an electron blocking layer. The light-emitting layer comprises a mixture of a host material (the electroluminescent material, A24:M91=5:5) and a dopant material (dye, RPD-19). The mass ratio (w / w) of the host material and the dopant material is 100:2. The deposition is carried out using a dual-source co-evaporation method. The deposition rate of the first compound is 0.1 nm / s, the deposition rate of the second compound is 0.1 nm / s, the deposition rate of RPD-19 is 0.002 nm / s, and the total deposition film thickness is 40 nm.

[0191] (6) A 5 nm layer of compound ET-17 was vacuum-deposited on the light-emitting layer as a hole blocking layer for the device;

[0192] (7) A mixture of compounds ET-66:ET-57 (50 / 50, w / w) was vacuum-deposited on the hole blocking layer as an electron transport layer with a film thickness of 25 nm.

[0193] (8) A 1 nm thick LiF layer was vacuum-deposited on the electron transport layer as an electron injection layer;

[0194] (9) A 150 nm thick layer of aluminum is vacuum-deposited on the electron injection layer as a cathode. The total deposition rate of the aforementioned organic layer and LiF is controlled at 0.1 nm / s, and the deposition rate of the metal electrode is 1 nm / s; the organic electroluminescent device is obtained.

[0195] Examples 2-96, Comparative Examples 1-2

[0196] An electroluminescent material and an organic electroluminescent device comprising the same are disclosed. The only difference between the electroluminescent material (the main material of the light-emitting layer) and Example 1 is that the electroluminescent material (the main material of the light-emitting layer) is replaced with the compounds in Table 1. The other structures, materials and preparation methods of the device are the same as those in Example 1. The "mass ratio" in Table 1 represents the mass ratio of the first compound to the second compound.

[0197] The structure of the main material in the comparative example is as follows:

[0198]

[0199] Device performance testing:

[0200] At the same brightness of 3000 cd / m² 2 The current density of the organic electroluminescent device was measured using a digital source meter and a luminance meter. The ratio of luminance to current density is the current efficiency. The voltage was increased at a rate of 0.1 V per second, and the luminance of the device was measured when it reached 3000 cd / m². 2 The voltage at which the organic light-emitting device operates is the driving voltage; the voltage at which the organic light-emitting device operates at 10000 cd / m² is recorded. 2 The current density at which the brightness is achieved is used to continuously operate the device, and the brightness of the organic electroluminescent device is measured from 10000 cd / m². 2 Attenuation to 9700 cd / m 2 The time taken is recorded as the lifetime of the device (T97).

[0201] In Table 1, the test values ​​of voltage, lifetime, and current efficiency of Comparative Example 1 are denoted as 1. The voltage, lifetime, and current efficiency of each embodiment and other comparative examples are the ratios of their respective test values ​​to the test values ​​of Comparative Example 1. The specific results are shown in Table 1.

[0202] Table 1

[0203]

[0204]

[0205]

[0206]

[0207]

[0208] In Table 1, "-Dn" indicates that n hydrogens in the compound are replaced by deuterium; for example, A145-D14 means that 14 hydrogens in A145 are replaced by deuterium.

[0209] As can be seen from the performance data in Table 1, the present invention, through the structural design and synergy of the first and second compounds, enables the electroluminescent material to have excellent carrier transport performance. As the main material of the light-emitting layer of the device, it can achieve carrier transport balance, suppress exciton quenching caused by π-π stacking, and reduce the energy level difference between the host and guest, promoting high host-guest energy transfer efficiency, thereby effectively reducing the operating voltage of the device and improving current efficiency and service life.

[0210] Furthermore, a comparison of Example 89 with Comparative Example 1 using a single variable model reveals that the difference lies in the different parent nuclei of the first compound. In Comparative Example 1, the benzo[a]pyroxene structure of the first compound exhibits a longer axial direction, resulting in a looser, irregular arrangement of molecules and a greater number of hole traps. Consequently, it exhibits a lower hole mobility, insufficient to match the stronger second compound, leading to higher voltage and lower efficiency. In Example 90, the first compound is the same as in Comparative Example 2, but the second compound differs from that of this invention. This invention has a specific substituent Ar4 attached to the naphthalene structure, and this substituent is crucial, playing a role in regulating the triplet energy level, spatial configuration, and carrier mobility. Experimental results show that because Ref. 2-2 of Comparative Example 2 lacks this regulating group, a carrier mismatch occurs, generating polarons in the luminescent layer, which quench the generated excitons, resulting in lower efficiency and shorter lifetime.

[0211] The present invention has been illustrated through the above embodiments, but the present invention is not limited to the above process steps, that is, it does not mean that the present invention must rely on the above process steps to be implemented. Those skilled in the art should understand that any improvements to the present invention, equivalent substitutions of the raw materials used in the present invention, additions of auxiliary components, and selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

Claims

1. An electroluminescent material, characterized in that, The electroluminescent material comprises a combination of a first compound and a second compound; The first compound has the structure shown in Formula I: Equation I; Ar1 is selected from any one of substituted or unsubstituted C6-C20 aryl groups and substituted or unsubstituted C3-C20 heteroaryl groups; Ar2 is selected from any one of the following groups, whether substituted or unsubstituted: ； in, The linking site of the representative group; X1 is selected from O, S, or NR. 11 Any one of them; R 11 Selected from any one or a combination of at least two of the following groups, either unsubstituted or deuterated: C6-C20 aryl, C3-C20 heteroaryl; R1, R2, and R3 are each independently -L'-R'; L1, L2, L3, and L' are each independently selected from any one of the single-bonded, substituted, or unsubstituted C6-C12 arylene groups; R' is independently selected from any one of substituted or unsubstituted C1-C10 straight-chain or branched alkyl groups, substituted or unsubstituted C6-C20 aryl groups, and substituted or unsubstituted C3-C20 heteroaryl groups; At least two adjacent groups among R1, R2, R3, and R' are not connected; m1, m2, and m3 are each independently selected from integers between 0 and 2; The second compound has the structure shown in Formula II: Formula II; Among them, L4, L5, and L7 are single bonds; L6 is selected from any one of the single-bonded, substituted or unsubstituted C6-C12 arylene groups; Ar4 is selected from any one of the following groups, substituted or unsubstituted: phenyl, biphenyl, naphthyl, C3-C12 heteroaryl; Ar5 is selected from any one of substituted or unsubstituted C6-C14 aryl groups and substituted or unsubstituted C3-C20 heteroaryl groups; Ar6 is selected from any one of the following groups, substituted or unsubstituted: phenyl, biphenyl, naphthyl, phenylnaphthyl, naphthylphenyl, C3-C12 heteroaryl; The substituents in Ar1, Ar2, L1, L2, L3, L', R', L6, Ar4, Ar5, and Ar6 are each independently selected from deuterium, halogen, cyano, C1-C10 straight-chain or branched alkyl, phenyl, biphenyl, terphenyl, naphthyl, phenylnaphthyl, naphthylphenyl, binaphthyl, C3-C12 heteroaryl, C3-C10 cycloalkyl, C2-C10 alkenyl, and C1-C10 alkoxy; the substituents may optionally be substituted with deuterium; at least two adjacent groups in the substituents are not connected; In the first compound, any hydrogen atom may be optionally substituted with deuterium, and in the second compound, any hydrogen atom may be optionally substituted with deuterium.

2. The electroluminescent material according to claim 1, characterized in that, The first compound has a structure as shown in any one of formulas IA, IB, and IC: ； Ar1, Ar2, L1, L2 and L3 have the same range of definition as in Equation I.

3. The electroluminescent material according to claim 2, characterized in that, The first compound has any of the following structures: ； Ar1, Ar2, L1, L2 and L3 have the same range of definition as in Equation I.

4. The electroluminescent material according to any one of claims 1-3, characterized in that, The substituents described in Ar2 are selected from any one or a combination of at least two of the following: deuterium, C1-C10 straight-chain or branched alkyl groups, phenyl, biphenyl, terphenyl, naphthyl, phenylnaphthyl, naphthylphenyl, binaphthyl, and C3-C12 heteroaryl groups, wherein the aforementioned groups may optionally be substituted with deuterium.

5. The electroluminescent material according to any one of claims 1-3, characterized in that, The Ar2 group is selected from any one of the following unsubstituted or deuterated groups: ； in, The linking site of the representative group; R A1 Each group is independently selected from any one or a combination of at least two of the following groups, which are unsubstituted or deuterated: phenyl, biphenyl, terphenyl, naphthyl, phenylnaphthyl, naphthylphenyl, binaphthyl, and C3-C12 heteroaryl.

6. The electroluminescent material according to any one of claims 1-3, characterized in that, The Ar1 is selected from any one of the following groups, whether substituted or unsubstituted: ； in, The linking site of the representative group.

7. The electroluminescent material according to any one of claims 1-3, characterized in that, L1, L2, and L3 are each independently selected from any one of the following groups: single bond, substituted, or unsubstituted: ； in, The linking site of the representative group.

8. The electroluminescent material according to claim 1, characterized in that, The first compound has a structure shown in any of the following: 。 9. The electroluminescent material according to claim 1, characterized in that, The second compound has a structure as shown in formula II-A or II-B: ； Among them, L4, L6, L7, Ar4 and Ar6 have the same defined range as in Formula II; X2 is either O or S; R4 and R5 are each independently selected from any one of deuterium, halogen, cyano, C1-C10 straight-chain or branched alkyl, phenyl, biphenyl, terphenyl, naphthyl, phenylnaphthyl, naphthylphenyl, binaphthyl, C3-C12 heteroaryl, C3-C10 cycloalkyl, C1-C10 alkoxy, and C2-C10 alkenyl, and the aforementioned groups may optionally be substituted with deuterium; at least two adjacent groups in R4 and R5 are not connected to each other; n1 is selected from integers from 0 to 3, n2 is selected from integers from 0 to 4, and n3 is selected from integers from 0 to 5.

10. The electroluminescent material according to claim 9, characterized in that, The second compound has a structure as shown in formula II-A1 or formula II-B1: ； L4, L6, Ar4, Ar6, R4, R5, X2, n1, n2 and n3 have the same definition as in claim 9.

11. The electroluminescent material according to claim 9 or 10, characterized in that, R4 and R5 are each independently selected from any one of the following unsubstituted or deuterated groups: ； in, The linking site of the representative group.

12. The electroluminescent material according to claim 1, 9, or 10, characterized in that, The Ar6 is selected from any one of the following groups, either unsubstituted or deuterated: ;in, The linking site of the representative group.

13. The electroluminescent material according to claim 1, 9, or 10, characterized in that, The group in the second compound It has any of the following structures: ； in, The connection site between the representative group and L7; Ar4 has the same definition as in Formula II.

14. The electroluminescent material according to claim 1, 9, or 10, characterized in that, The Ar4 group is selected from any one of the following unsubstituted or deuterated groups: ； in, The linking site of the representative group.

15. The electroluminescent material according to claim 1, characterized in that, The second compound has a structure shown in any of the following: 。 16. The electroluminescent material according to claim 1, characterized in that, The mass ratio of the first compound to the second compound is (0.1-2):

1.

17. An application of the electroluminescent material as described in any one of claims 1-16, characterized in that, The electroluminescent material is used as the light-emitting layer material in organic electroluminescent devices.

18. An organic electroluminescent device, characterized in that, The organic electroluminescent device includes a first electrode, a second electrode, and an organic layer disposed between the first electrode and the second electrode, wherein the organic layer includes the electroluminescent material as described in any one of claims 1-16.

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