Organic light-emitting device and display device comprising same

Abstract

The invention provides an organic light-emitting device and a display device comprising the same, the organic light-emitting device comprises an anode, a cathode and an organic layer arranged between the anode and the cathode, host materials of the light-emitting layer comprise a first host material and a second host material, the first host material is an organic compound containing an electron-donating group, and the second host material is an organic compound containing an electron-donating group. The second main body material is an organic compound containing an electron withdrawing group, T1N-T1P is greater than 0 and less than or equal to 0.20 eV, HOMOP-HOMON is greater than or equal to 0.20 eV and less than or equal to 0.70 eV, and LUMOP-LUMON is greater than or equal to 0.40 eV and less than or equal to 0.80 eV. Through the design and energy level matching of the two main body materials in the light-emitting layer, the organic light-emitting device has relatively high light-emitting efficiency, relatively low driving voltage and relatively long service life.

Description

Technical Field

[0001] The present invention belongs to the technical field of organic electroluminescence, and in particular relates to an organic electroluminescence device and a display device comprising the same. Background Art

[0002] Organic Light Emission Diode (OLED) is a new display device that has emerged in recent years. It can provide highly saturated red, green and blue colors. The full-color display device made of it does not require an additional backlight source and has the advantages of brilliant colors, lightness, thinness, softness, high brightness, fast response and wide viewing angle. The core of OLED devices is a thin film structure containing a variety of organic functional materials. Common functionalized organic materials include: hole injection materials, hole transport materials, hole blocking materials, electron injection materials, electron transport materials, electron blocking materials, luminescent host materials and luminescent guest materials (dyes). When the OELD device is powered on, electrons and holes are injected and transported to the luminescent area respectively and recombine there, thereby generating excitons and emitting light.

[0003] In order to further meet the ever-increasing demand for the optoelectronic performance of OLED devices and the energy-saving needs of mobile electronic devices, it is necessary to continuously develop new and efficient organic functional materials for OLED. In recent years, industry insiders have been constantly trying and exploring ways to improve device efficiency and stability, most of which are seeking new materials to improve device performance. A large number of novel materials have been developed for use in organic electroluminescent devices. Although they have improved device performance to a certain extent, there is limited room for improving device performance by simply replacing materials, and the materials cannot be effectively matched, which limits the improvement of device performance.

[0004] In addition to developing new functional materials, researchers also try to use a combination of different materials to optimize device performance. For example, dual-host materials and phosphorescent dyes are used to prepare the light-emitting layer. Compared with a single host material, the use of dual-host materials is more likely to balance the transmission of electrons and holes, thereby improving the luminescence performance of the device. In dual-host devices, too many excitons are formed on the electronic host, which is prone to exciton concentration quenching. Furthermore, in order to transfer the unluminous energy inside the light-emitting layer, the researchers tried to use a material with TADF (thermally activated delayed fluorescence) properties as one of the hosts to transfer T 1Energy, reduce the exciton concentration, for example, in the light-emitting device disclosed in CN113725377A, the light-emitting layer adopts a dual-host design, and the second host material is a TADF material; this dual-host design limits the choice of materials, and TADF materials are difficult to design and synthesize. In addition, most of the current dual-host devices consider the energy level matching of the host material and the adjacent layers, but the matching degree of the two host materials in the light-emitting layer is not good, resulting in obvious deficiencies in the efficiency, life and energy consumption of the device. Based on this, the development of higher performance organic electroluminescent devices is an urgent problem to be solved in this field. Summary of the invention

[0005] In view of the deficiencies in the prior art, the object of the present invention is to provide an organic electroluminescent device and a display device comprising the same, wherein the organic electroluminescent device has higher luminous efficiency, lower driving voltage and longer life through the design and energy level matching of two main materials in the light-emitting layer.

[0006] In order to achieve the purpose of the invention, the present invention adopts the following technical solutions:

[0007] In a first aspect, the present invention provides an organic electroluminescent device, comprising an anode, a cathode and an organic layer disposed between the anode and the cathode, wherein the organic layer comprises a light-emitting layer, and the main material of the light-emitting layer comprises a combination of a first main material and a second main material; the first main material is an organic compound containing an electron-donating group, and its triplet energy level is T 1P , the HOMO energy level is HOMO P , the LUMO energy level is LUMO P The second main material is an organic compound containing an electron-withdrawing group, and its triplet energy level is T 1N , the HOMO energy level is HOMO N , the LUMO energy level is LUMO N ; 0<T 1N -T 1P ≤0.20eV, 0.20eV≤HOMO P -HOMO N ≤0.70eV, 0.40eV≤LUMO P -LUMO N ≤0.80eV.

[0008] The present invention has found through research that in conventional dual-host OLED devices, the electron-type host is more likely to form excitons, and then transfer the exciton energy to the doped dye to release it in the form of light, while the hole-type host T 1 The energy level is higher than that of the electronic host T 1Energy level, resulting in too many excitons formed on the electronic host, which is prone to exciton concentration quenching; moreover, the electron and hole transfer between the two hosts is rarely considered in consideration of the energy level of the material of the heterogeneous carrier transport functional layer. Based on the above findings, in the organic electroluminescent device provided by the present invention, the first host material and the second host material of the light-emitting layer are designed and energy level matched so that they have the following matching and synergistic relationship: (1) The first host material is a compound containing an electron-donating group, which serves as a hole-type host, and the second host material is an organic compound containing an electron-withdrawing group, which serves as an electronic host. The first host material generates a minority of exciton energy, and the second host material generates a majority of exciton energy; the triplet energy level T of the electronic host 1N >Triplet energy level T of hole-type host 1P , thus, the excess exciton energy is transferred to the dye (also known as "phosphorescent dye", "doping material", "guest material") through the hole-type host, thereby reducing the exciton concentration and quenching without reducing the number of excitons, and effectively enhancing the exciton utilization rate, ultimately improving the efficiency and stability of the device. (2) 0<T 1N -T 1P ≤0.20eV, avoiding the ineffective transfer of excitons between the two host materials, and further improving the luminescence efficiency of the device. (3) By designing the HOMO energy level difference and LUMO energy level difference between the first host material and the second host material, the carrier transport in the light-emitting layer can be balanced, and electrons and holes can be more effectively accepted to form more excitons, promoting the efficient transfer of energy from the host material to the dye.

[0009] Specifically, the schematic diagram of the exciton energy transfer process of the organic electroluminescent device provided by the present invention during the light emission process is as follows: Figure 2 As shown, the first host material generates a minority of exciton energy, and its triplet energy level is T 1P , the second host material generates a majority of exciton energy, and its triplet energy level is T 1N , the triplet energy level of the phosphorescent dye is T G , T 1N >T 1P , and its energy is close to that required by phosphorescent dyes, thereby effectively improving the luminescence performance of the device.

[0010] Therefore, the present invention improves the hole and electron transport capacity of the host material and enhances the energy utilization efficiency through the design of the light-emitting layer, especially the design, energy level matching and mutual coordination of the first host material and the second host material, thereby effectively improving the luminous efficiency of the organic electroluminescent device, reducing the driving voltage and energy consumption, and extending the working life of the device.

[0011] In the present invention, the term "organic compound containing electron donating groups" can be understood as "P-type organic compound", that is, the first host material is a "hole-type host" with excellent hole transport properties. The term "organic compound containing electron withdrawing groups" can be understood as "N-type organic compound", that is, the second host material is an "electron-type host" with excellent electron transport properties.

[0012] The following are preferred technical solutions of the present invention, but are not intended to 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 and realized.

[0013] In the present invention, 0<T 1N -T 1P ≤0.20eV, where T 1N With T 1P The difference can be 0.01eV, 0.03eV, 0.05eV, 0.08eV, 0.10eV, 0.12eV, 0.15eV, 0.18eV, etc.

[0014] In the present invention, 0.20eV≤HOMO P -HOMO N ≤0.70eV, HOMO P and HOMO N The difference can be 0.22eV, 0.25eV, 0.28eV, 0.30eV, 0.35eV, 0.35eV, 0.38eV, 0.40eV, 0.42eV, 0.45eV, 0.48eV, 0.50eV, 0.52eV, 0.55eV, 0.58eV, 0.60eV, 0.62eV, 0.65eV or 0.68eV, etc. Preferably, 0.30eV≤HOMO P -HOMO N ≤0.67eV.

[0015] In the present invention, 0.40eV≤LUMO P -LUMO N ≤0.80eV, LUMO P With LUMO N The difference may be 0.42 eV, 0.45 eV, 0.48 eV, 0.50 eV, 0.52 eV, 0.55 eV, 0.58 eV, 0.60 eV, 0.62 eV, 0.65 eV, 0.68 eV, 0.70 eV, 0.72 eV, 0.75 eV or 0.78 eV, preferably, 0.55 eV≤LUMO P -LUMO N ≤0.78eV.

[0016] In a preferred technical solution, 0.30 eV ≤ HOMO P -HOMO N ≤0.67eV; and / or, 0.55eV≤LUMO P -LUMO N ≤0.78eV.

[0017] Preferably, the organic layer further includes a hole transport layer, and the hole transport layer is arranged between the light-emitting layer and the anode.

[0018] Preferably, the HOMO energy level of the material of the hole transport layer is HOMO HT , HOMO HT -HOMO N ≥0.40eV, e.g. HOMO HT and HOMO N The difference can be 0.42eV, 0.45eV, 0.48eV, 0.50eV, 0.55eV, 0.60eV, 0.65eV, 0.70eV, 0.75eV, 0.80eV, 0.85eV, 0.90eV, 0.95eV or 1.00eV, etc., and more preferably, 0.40eV≤HOMO HT -HOMO N ≤0.60eV.

[0019] Preferably, the organic layer further includes a hole blocking layer, and the hole blocking layer is arranged between the light-emitting layer and the cathode.

[0020] Preferably, the LUMO energy level of the material of the hole blocking layer is HB ,LUMO P -LUMO HB ≥0.50eV, e.g. LUMO P With LUMO HB The difference can be 0.52eV, 0.55eV, 0.58eV, 0.60eV, 0.65eV, 0.70eV, 0.75eV, 0.80eV or 0.85eV, etc., and more preferably, 0.50eV≤LUMO P -LUMO HB ≤0.80eV.

[0021] As a preferred technical solution of the present invention, in the design of the organic electroluminescent device, the HOMO energy level difference between the adjacent layer (hole transport layer) material in the anode direction of the light-emitting layer and the electronic type second host material is increased, so that the HOMO HT -HOMO N≥0.40eV, reducing the ineffective electron-hole recombination on the electronic host and enhancing the balance between the number of electrons and holes; in addition, due to the existence of the HOMO energy level difference between the adjacent layer (hole transport layer) material and the electronic second host material, it is possible to prevent excess holes from jumping to the electron transport layer. Similarly, the hole-type first host material is designed to have a large LUMO energy level difference with the adjacent layer (hole blocking layer) in the cathode direction of the light-emitting layer, and to make the LUMO P -LUMO HB ≥0.50eV, the energy level difference between the layers forms an energy barrier, preventing the excess electrons from migrating to the hole transport layer, locking the electrons in the light-emitting layer, increasing the probability of exciton generation, and further ensuring the number of excitons; at the same time, due to T 1N >T 1P , avoiding the exciton concentration quenching caused by the LUMO energy level design of the first host material and the hole blocking layer; through the design of the host material and its effective energy level design and matching with the adjacent layers, the efficient transfer of electrons and holes is ensured, the exciton energy is controlled in the light-emitting layer, and the energy capture of the dye is promoted, so that the organic electroluminescent device has higher luminous efficiency, longer working life and lower driving voltage.

[0022] Furthermore, it is preferred to design 0.40eV≤HOMO HT -HOMO N ≤0.60eV, 0.50eV≤LUMO P -LUMO HB ≤0.80eV, so that the HOMO / LUMO energy levels of the first host material and the second host material are effectively matched with the HOMO energy level of the adjacent hole transport layer and the LUMO energy level of the hole blocking layer, thereby ensuring efficient transfer of electrons and holes, controlling the balance of electrons and holes in the light-emitting layer, controlling the exciton energy in the light-emitting layer, and promoting energy capture of the dye (doped material), thereby further reducing the voltage and energy consumption of the organic electroluminescent device and improving the device life.

[0023] Preferably, the mass ratio of the first host material to the second host material is 1:(0.1-10), for example, it can be 1:0.2, 1:0.3, 1:0.5, 1:0.8, 1:1, 1:1.2, 1:1.4, 1:1.6, 1:1.8, 1:2, 1:3, 1:4, 1:5, 1:6, 1:7, 1:8 or 1:9, and more preferably 1:(0.6-1.5).

[0024] Preferably, the first host material has a structure as shown in Formula I:

[0025] Ar 2 -L 1 -Ar 1 Formula I.

[0026] In Formula I, Ar 1 Substituted or unsubstituted -* represents the attachment site of the group.

[0027] In Formula I, the dotted line represents ring C 1 、Ring C 2 is an optional structure; namely, ring C 1 Presence or absence of ring C 2 Presence or absence; Ring C 1 、Ring C 2 Each is independently fused to the benzene ring in carbazole in any feasible manner.

[0028] Ring C 1 、Ring C 2 Each is independently selected from any one of a substituted or unsubstituted C6-C30 aromatic ring and a substituted or unsubstituted C3-C30 heteroaromatic ring.

[0029] In Formula I, L 1 is selected from any one of a single bond, a substituted or unsubstituted C6-C30 arylene group, and a substituted or unsubstituted C3-C30 heteroarylene group; when L 1 When it is a single bond, it represents Ar 1 with Ar 2 Connect directly with a single button.

[0030] In Formula I, Ar 2 Any one selected from a substituted or unsubstituted C6-C30 aryl group, a substituted or unsubstituted C3-C30 heteroaryl group, a substituted or unsubstituted C6-C60 arylamino group, and a substituted or unsubstituted C3-C60 heteroarylamino group.

[0031] Ar 1 ,Ar 2 、Ring C 1 、Ring C 2 , L 1 The substituted substituents are each independently selected from any one of halogen, cyano, nitro, hydroxyl, amino, carboxyl, nitro, thiol, C1-C20 straight or branched alkyl, C2-C20 alkenyl, C1-C20 alkoxy, C1-C20 alkylamino, C3-C20 cycloalkyl, C2-C20 heterocycloalkyl, C6-C30 aryl, C3-C30 heteroaryl, C6-C30 aryloxy, C3-C30 heteroaryloxy, C6-C30 arylamino, and C3-C30 heteroarylamino, or a combination of at least two thereof; the substituted substituents are each independently not connected to the adjacent ring structure or are connected to form a ring by chemical bonds.

[0032] In the present invention, the "substituted or unsubstituted" group may be substituted with one substituent or with multiple substituents. When there are multiple substituents (at least 2), they may be the same or different substituents. When the same expressions are mentioned below, they have the same meaning.

[0033] Unless otherwise specified, the selection ranges of substituents related to Formula I are as shown above and will not be repeated here.

[0034] In the present invention, the halogen may be fluorine, chlorine, bromine or iodine. The same descriptions below have the same meanings.

[0035] In the present invention, the expression of chemical elements, unless otherwise specified, includes the concept of isotopes with the same chemical properties. For example, hydrogen (H) includes 1 H (hydrogen), 2 H (deuterium, D), 3 H (tritium, T), etc.; carbon (C) includes 12 C. 13 C, etc.

[0036] In the present 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.

[0037] In the present invention, the expression of a ring structure crossed by “—” indicates that the connection site is any position on the ring structure that can form a bond.

[0038] In the present invention, "-*" and "*" both represent the connection site of a group.

[0039] In the present invention, the expression of Ca-Cb means that the number of carbon atoms in the group is ab. Unless otherwise specified, the number of carbon atoms does not include the number of carbon atoms in the substituent.

[0040] In the present invention, “each independently” means that when there are multiple subjects, they may be the same as or different from each other.

[0041] In the present invention, the C6-C30 may be C6, C9, C10, C12, C14, C16, C18, C20, C22, C24, C26 or C28.

[0042] The C3-C30 can all be C3, C4, C5, C6, C9, C10, C12, C14, C16, C18, C20, C22, C24, C26 or C28, etc.

[0043] The C1-C20 can all be C1, C2, C3, C4, C5, C6, C7, C8, C9, C10, C11, C12, C13, C14, C15, C16, C17, C18 or C19, etc.

[0044] The C3-C20 can all be C3, C4, C5, C6, C7, C8, C9, C10, C11, C12, C13, C14, C15, C16, C17, C18 or C19, etc.

[0045] The C6-C60 can all be C6, C9, C10, C12, C14, C16, C18, C20, C22, C24, C26, C28, C30, C32, C34, C36, C38, C40, C42, C44, C46, ​​C48, C50, C52, C54, C56 or C58, etc.

[0046] The C3-C60 can all be C3, C4, C5, C6, C9, C10, C12, C14, C16, C18, C20, C22, C24, C26, C28, C30, C32, C34, C36, C38, C40, C42, C44, C46, ​​C48, C50, C52, C54, C56 or C58, etc.

[0047] The C2-C20 can all be C2, C3, C4, C5, C6, C7, C8, C9, C10, C11, C12, C13, C14, C15, C16, C17, C18 or C19, etc.

[0048] In the present invention, the C6-C30 aryl group, more preferably the C6-C20 aryl group, includes a monocyclic aryl group and a condensed aryl group; the monocyclic aryl group means that the group contains at least one phenyl group, and when it contains at least two phenyl groups, the phenyl groups are connected by a single bond, and exemplary examples include but are not limited to: phenyl, biphenyl, terphenyl, etc.; the condensed aryl group means that the group contains at least two aromatic rings, and the aromatic rings share two adjacent carbon atoms. The fused groups include, but are not limited to, naphthyl, anthracenyl, phenanthryl, indenyl, fluorenyl and its derivatives (9,9-dimethylfluorenyl, 9,9-diethylfluorenyl, 9,9-dipropylfluorenyl, 9,9-dibutylfluorenyl, 9,9-dipentylfluorenyl, 9,9-dihexylfluorenyl, 9,9-diphenylfluorenyl, 9,9-dinaphthylfluorenyl, spirobifluorenyl, benzofluorenyl, etc.), fluoranthenyl, triphenylene, pyrenyl, perylene, The aforementioned groups include all possible connection modes thereof; monocyclic aromatic groups and condensed aromatic groups connected by a single bond also belong to the scope of aromatic groups, such as phenylnaphthyl, naphthylphenyl, naphthylnaphthyl, phenylanthracenyl, diphenylanthracenyl, biphenylanthracenyl, etc.

[0049] The C3-C30 heteroaryl, further preferably C3-C20 heteroaryl, includes a monocyclic heteroaryl or a condensed ring heteroaryl. The monocyclic heteroaryl means that the molecule contains at least one heteroaryl. When the molecule contains a heteroaryl and other groups (such as aryl, heteroaryl, etc.), the heteroaryl and other groups are connected by a single bond, including but not limited to pyridyl, pyrimidyl, pyrazinyl, pyridazinyl, triazinyl, furanyl, thienyl, pyrrolyl, triazolyl, etc. The fused ring heteroaryl group means a group containing at least one aromatic heterocycle and one aromatic ring (aromatic heterocycle or aromatic ring) in the molecule, and the two share two adjacent atoms fused to each other, including but not limited to: quinolyl, isoquinolyl, quinoxalinyl, quinazolinyl, benzimidazolyl, benzofuranyl, benzothiophenyl, isobenzofuranyl, isobenzothiophenyl, indolyl, dibenzofuranyl, dibenzothiophenyl, carbazolyl and its derivatives (N-phenylcarbazolyl, N-naphthylcarbazolyl, benzocarbazolyl, dibenzocarbazolyl, indolcarbazolyl, azacarbazolyl, etc.), acridinyl, phenothiazinyl, phenoxazinyl, hydrogenated acridinyl, benzofurancarbazolyl, benzothiophenylcarbazolyl, azadibenzothiophenyl, azadibenzofuranyl, etc. The aforementioned groups include all feasible connection modes thereof.

[0050] Specific examples of the C6-C30 arylene group include divalent groups obtained by removing a hydrogen atom from the above-mentioned aryl groups; specific examples of the C3-C30 heteroarylene group include divalent groups obtained by removing a hydrogen atom from the above-mentioned heteroaryl groups.

[0051] In the present invention, the C6-C30 aryloxy group is a monovalent group formed by connecting the above-mentioned aryl groups and O, and the C3-C30 heteroaryloxy group is a monovalent group formed by connecting the above-mentioned heteroaryl groups and O.

[0052] In the present invention, a specific example of the C6-C60 arylamino group and the C6-C30 arylamino group is -NH 2 The monovalent group obtained by replacing at least one hydrogen in the group with the above-mentioned aryl group includes, but is not limited to, phenylamino, methylphenylamino, naphthylamino, anthracenylamino, phenanthrenylamino, biphenylamino, etc. Specific examples of the C3-C60 heteroarylamino and C3-C30 heteroarylamino are -NH 2 The monovalent group in which at least one hydrogen in the amino group is replaced by the above-mentioned heteroaryl group includes, but is not limited to, pyridylamino, pyrimidylamino, dibenzofuranylamino and the like.

[0053] The C1-C20 straight chain or branched alkyl group, preferably a C1-C10 straight chain or branched alkyl group, illustratively 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.

[0054] Specific examples of the C1-C20 alkoxy group include monovalent groups obtained by connecting the above-mentioned linear or branched alkyl groups to O.

[0055] A specific example of the C1-C20 alkylsilyl group is -SiH 3 A monovalent group obtained by replacing at least one hydrogen in the group with the straight-chain or branched alkyl group; a specific example of the C1-C20 alkylamino group is -NH 2 A monovalent group obtained by replacing at least one hydrogen atom in the alkyl group with the above-mentioned straight-chain or branched-chain alkyl group.

[0056] The C3-C20 cycloalkyl, preferably C3-C10 cycloalkyl, includes monocycloalkyl or polycycloalkyl. Monocycloalkyl refers to an alkyl group containing a single cyclic structure, and polycycloalkyl refers to a structure composed of two or more cycloalkyl groups sharing one or more carbon atoms on the ring; exemplary examples include but are not limited to: cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, adamantyl, etc.

[0057] Specific examples of the C2-C20 heterocycloalkyl group include monovalent groups formed by replacing at least one carbon atom in the above cycloalkyl group with a heteroatom (such as N, O or S, etc.), including but not limited to epoxy, oxetanyl, tetrahydrofuranyl, tetrahydrothiophenyl, tetrahydropyrrolyl, tetrahydropyranyl, piperidinyl, piperazinyl, dioxane, morpholinyl and the like.

[0058] The C2-C20 alkenyl, preferably C2-C10 alkenyl, contains at least one C=C, illustratively including but not limited to: vinyl, propenyl, allyl, butenyl, pentenyl, hexenyl, heptenyl, octenyl, nonenyl, decenyl, butadienyl, pentadienyl and the like.

[0059] Preferably, the ring C 1 、Ring C 2 Each independently selected from Any of the above, the dotted line represents a fused bond; U 1 Selected from O, S, NR 11 or CR 12 R 13 Any one of R 11 , R 12 , R 13Each is independently selected from any one of hydrogen, C1-C20 straight or branched alkyl, C3-C20 cycloalkyl, C6-C30 aryl, and C3-C30 heteroaryl; the R 12 and R 13 Not connected or connected to form a ring through chemical bonds.

[0060] Preferably, the Ar 1 Any one selected from the following substituted or unsubstituted groups:

[0061] -* represents the attachment site of the group.

[0062] U 1 Selected from O, S, NR 11 or CR 12 R 13 Any one of .

[0063] R 11 , R 12 , R 13 Each is independently selected from any one of hydrogen, C1-C20 straight or branched alkyl, C3-C20 cycloalkyl, C6-C30 aryl, and C3-C30 heteroaryl; the R 12 and R 13 Not connected or connected to form a ring through chemical bonds.

[0064] Preferably, the U 1 Selected from O, S or NR 11 Any one of, more preferably NR 11 .

[0065] Preferably, the R 11 , R 12 , R 13 Each is independently selected from any one of C1-C10 (e.g., C2, C3, C4, C5, C6, C8, etc.) straight chain or branched alkyl, C6-C20 (e.g., C6, C7, C8, C9, C10, C12, C14, C16 or C18, etc.) aryl, and further preferably any one of C1-C6 straight chain or branched alkyl, phenyl, biphenyl, terphenyl, naphthyl, phenylnaphthyl or naphthylphenyl.

[0066] Preferably, the Ar 1 Selected from Any one of .

[0067] Preferably, the Ar 2 Any one selected from the following substituted or unsubstituted groups:

[0068]

[0069]

[0070]

[0071] -* represents the attachment site of the group;

[0072] Ar 21 ,Ar 22 Each is independently selected from any one of substituted or unsubstituted C6-C30 aryl groups, substituted or unsubstituted C3-C30 heteroaryl groups, further preferably any one of substituted or unsubstituted C6-C20 (for example, C6, C9, C10, C12, C14, C15, C16, C18, etc.) aryl groups, substituted or unsubstituted C3-C30 (for example, C3, C4, C5, C6, C9, C10, C12, C14, C15, C16, C18, etc.) heteroaryl groups, and further preferably any one of phenyl, biphenyl, naphthyl, phenylnaphthyl, naphthylphenyl, fluorenyl, 9,9-dimethylfluorenyl, 9,9-diphenylfluorenyl, methylphenylfluorenyl and spirobifluorenyl.

[0073] Preferably, the Ar 21 ,Ar 22 Each independently selected from

[0074] Preferably, the L 1 Any one selected from a single bond, a substituted or unsubstituted C6-C20 (e.g., C6, C9, C10, C12, C14, C15, C16, C18, etc.) arylene group, more preferably a single bond, Any one of .

[0075] Preferably, the first host material is selected from any one or a combination of at least two of the following compounds P1-P102:

[0076]

[0077]

[0078]

[0079]

[0080]

[0081] In the present invention, the second host material is an organic compound containing an electron-withdrawing group, which is compounded with the first host material, which is more conducive to the efficient transfer of energy between the host material and the dye (dopant material), thereby further optimizing the luminescent performance of the device.

[0082] Preferably, the second host material has a structure as shown in Formula II:

[0083]

[0084] In Formula II, A 1 , A 2 , A 3 Each is independently selected from any one of a substituted or unsubstituted C6-C30 aryl group and a substituted or unsubstituted C3-C30 heteroaryl group.

[0085] In Formula II, L 2 is selected from any one of a single bond, a substituted or unsubstituted C6-C30 arylene group, and a substituted or unsubstituted C3-C30 heteroarylene group; when L 3 When it is a single bond, it represents A 1 It is directly connected to the triazine ring via a single bond.

[0086] A 1 , A 2 , A 3 , L 2 The substituents substituted in are each independently selected from any one or a combination of at least two of halogen, cyano, nitro, hydroxyl, amino, carboxyl, nitro, sulfhydryl, C1-C20 straight or branched alkyl, C2-C20 alkenyl, C1-C20 alkoxy, C1-C20 alkylamino, C3-C20 cycloalkyl, C2-C20 heterocycloalkyl, C6-C30 aryl, C3-C30 heteroaryl, C6-C30 aryloxy, C3-C30 heteroaryloxy, C6-C30 arylamino, and C3-C30 heteroarylamino. Unless otherwise specified, the selection range of the substituents related to Formula II is as shown above and will not be repeated one by one.

[0087] Preferably, the A 1 Any one selected from a substituted or unsubstituted C15-C30 aryl group and a substituted or unsubstituted C12-C30 heteroaryl group.

[0088] Further preferably, the A 1 Any one selected from the following substituted or unsubstituted groups:

[0089] -* represents the attachment site of the group.

[0090] Preferably, the A 2 , A 3 Each is independently selected from any one of the following substituted or unsubstituted groups: -* represents the attachment site of the group.

[0091] Preferably, the L 2 Any one selected from a single bond, a substituted or unsubstituted C6-C20 (e.g., C6, C7, C8, C9, C10, C12, C14, C16, or C18, etc.) arylene group, and a substituted or unsubstituted C3-C20 (e.g., C4, C5, C6, C7, C8, C9, C10, C12, C14, C16, or C18, etc.) heteroarylene group, and a single bond, Any one of .

[0092] Preferably, the second host material is selected from any one or a combination of at least two of the compounds shown in the following N1-N55:

[0093]

[0094]

[0095]

[0096] In a preferred technical solution of the present invention, the first main material is P18, and the second main material is selected from any one of N3, N23, N25, N38, N41, and N55, or a combination of at least two of them.

[0097] In another preferred technical solution of the present invention, the first main material is selected from any one of P4, P8, P14, P17, P18, P24, P40, P47, P68, P75, P76, and P91, or a combination of at least two thereof, and the second main material is N55.

[0098] In another preferred technical solution of the present invention, the first main material is P68, and the second main material is N3.

[0099] In another preferred technical solution of the present invention, the first main material is P10 and / or P12, and the second main material is N53.

[0100] Preferably, the light-emitting layer further includes a doping material, which is also called a "guest material", "guest", "dye" or "luminescent dye".

[0101] Preferably, the doping material is a phosphorescent doping material.

[0102] Preferably, based on the mass of the main material being 100%, the mass of the doping material in the light-emitting layer is 0.1%-10%, for example, it can be 0.5%, 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8% or 9%.

[0103] Preferably, the organic layer further comprises any one of a hole injection layer, an electron transport layer, and an electron injection layer, or a combination of at least two of them.

[0104] Preferably, the organic electroluminescent device comprises an anode, a hole injection layer, a hole transport layer, a light-emitting layer, a hole blocking layer, an electron transport layer, an electron injection layer and a cathode which are arranged in sequence.

[0105] In a preferred technical solution, a substrate is provided on the side of the anode facing away from the organic layer or the side of the cathode facing away from the organic layer. The substrate is a rigid substrate or a flexible substrate, which has excellent mechanical strength, thermal stability, waterproofness, and transparency; the rigid substrate exemplarily includes but is not limited to: a glass substrate, a Si substrate, etc., and the flexible substrate exemplarily includes but is not limited to: a polyvinyl alcohol (PVA) film, a polyimide (PI) film, a polyester (PET) film, etc.; the substrate of the present invention is preferably a rigid glass substrate.

[0106] In a preferred technical solution, the anode can be formed by sputtering or depositing a material used as the first electrode on a substrate. The anode is preferably a conductive compound, alloy, metal, and a mixture of such materials with a large work function. Inorganic materials can be used, including metals, metal oxides, stacks formed by alternating metals and metals, stacks formed by alternating metals and non-metals, etc.; the metal oxides include indium tin oxide (ITO), zinc oxide (ZnO), indium zinc oxide (IZO), tin oxide (SnO), etc., and metals include gold, silver, copper, aluminum, etc. with a relatively high work function; the anode of the present invention is preferably ITO / Ag / ITO.

[0107] The organic layer can be formed on the electrode by vacuum evaporation, spin coating, printing, etc., or by other methods, not limited to the above methods. In the preferred technical solution of the present invention, the device prepared by vacuum evaporation is described.

[0108] In a preferred technical solution, the hole injection layer can be a single compound material or a combination of multiple compounds. For example, the hole injection layer can use one or more compounds of HT-1 to HT-51, or one or more compounds of HI-1 to HI-3; or one or more compounds of HT-1 to HT-51 can be doped with one or more compounds of HI-1 to HI-3.

[0109]

[0110] In a preferred technical solution, the material of the hole transport layer can be selected from, but 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 in HT-1 to HT-51 below; or any combination thereof.

[0111]

[0112]

[0113]

[0114] In the preferred technical solution of the present invention, the light-emitting layer adopts phosphorescent luminescence technology, the main material is a combination of the aforementioned first main material and the second main material, and the doping material (phosphorescent doping material, guest material, dye) includes a green light material, which can be selected from, but not limited to, one or more combinations of GPD-1 to GPD-47 listed below.

[0115] Where D is deuterium.

[0116] In a preferred technical solution, the doping material (phosphorescent doping material, guest material, dye) includes a red light material, which can be selected from, but not limited to, one or more combinations of RPD-1 to RPD-28 listed below.

[0117]

[0118]

[0119] In a preferred technical solution, the material of the electron transport layer can be selected from, but not limited to, any one or a combination of at least two of the compounds ET-1 to ET-73 listed below.

[0120]

[0121]

[0122]

[0123]

[0124] In one aspect of the present invention, a hole blocking layer (HBL) is located between the electron transport layer and the light emitting layer. The hole blocking layer may be, but not limited to, one or more compounds of ET-1 to ET-73, or one or more compounds of PH-1 to PH-46; or a mixture of one or more compounds of ET-1 to ET-73 and one or more compounds of PH-1 to PH-46.

[0125] In a preferred technical solution, the material of the electron injection layer includes but is not limited to one or more combinations of the following: LiQ, LiF, NaCl, CsF, Li 2 O、Cs 2 CO 3 , BaO, Na, Li, Ca, Mg or Yb.

[0126] In a preferred technical solution, the cathode can be made of metals or alloys such as magnesium (Mg), silver (Ag), aluminum (Al), aluminum-lithium (Al-Li), calcium (Ca), ytterbium (Yb), magnesium-indium (Mg-In), magnesium-silver (Mg-Ag), and any combination thereof. It can also be made of metals such as ITO, metal mixtures, oxides, etc. The cathode of the present invention is preferably aluminum.

[0127] In a second aspect, the present invention provides a display device, comprising the organic electroluminescent device as described in the first aspect.

[0128] Compared with the prior art, the present invention has the following beneficial effects:

[0129] In the organic electroluminescent device provided by the present invention, the light-emitting layer adopts a dual-host design, the first host material can enhance the hole migration characteristics, and the second host material has excellent electron transport characteristics. Through the design and compounding of the specific first host material and the second host material, the hole and electron transport capacity of the host material is improved, the recombination probability of electrons and holes is increased, and the luminescence performance of the device is improved. At the same time, through the design and mutual matching of the triplet energy level and HOMO / LUMO energy level of the first host material and the second host material, the ineffective transfer of energy between the hosts is avoided, and the energy required by the dye is similar, the energy transfer efficiency between the host material and the dye is improved, and efficient luminescence is achieved. The organic electroluminescent device effectively improves the luminous efficiency, reduces the driving voltage and energy consumption, and prolongs the working life of the device through the design and energy level matching of the host material of the light-emitting layer. BRIEF DESCRIPTION OF THE DRAWINGS

[0130] Figure 1 A schematic diagram of the structure of an organic electroluminescent device provided in a specific embodiment of the present invention;

[0131] Among them, 1-anode, 2-hole injection layer, 3-hole transport layer, 4-light-emitting layer, 5-hole blocking layer, 6-electron transport layer, 7-electron injection layer, 8-cathode;

[0132] Figure 2 It is a schematic diagram of the exciton energy transfer process during the light-emitting process of the organic electroluminescent device of the present invention. DETAILED DESCRIPTION

[0133] The technical solution of the present invention is further described below by specific implementation methods. It should be understood by those skilled in the art that the embodiments are only to help understand the present invention and should not be regarded as specific limitations of the present invention.

[0134] In the present invention, the first host material and the second host material can be prepared by methods disclosed in the prior art. For example, the synthesis method of the first host material having the structure shown in Formula I can refer to the contents disclosed in the prior art CN112640141A, KR102303190B1, and CN111868210A; the synthesis method of the second host material having the structure shown in Formula II can refer to the contents disclosed in the prior art CN113277988A and CN108463456A.

[0135] Example 1

[0136] An organic electroluminescent device, the structural schematic diagram of which is as follows Figure 1As shown, it includes an anode 1 (ITO / Ag / ITO), a hole injection layer 2, a hole transport layer 3, a light-emitting layer 4, a hole blocking layer 5, an electron transport layer 6, an electron injection layer 7, and a cathode 8 (Al) which are stacked in sequence; the preparation method is as follows:

[0137] (1) On a glass substrate with an anode layer of ITO / Ag / ITO having a film thickness of 150 nm, a vacuum evaporation method was used to deposit the anode layer of ITO / Ag / ITO at a vacuum degree of 2×10 -4 Each film layer was deposited at 100 ℃ and 100 ℃. First, a hole injection layer, i.e., a HT-4:3% HI-3 film, was formed on ITO (HT-4 was 100%, and 3% was the doping ratio of HI-3 in the hole injection layer). The evaporation rate ratio of HT-4 to HI-3 was 1:0.03, and the evaporation rate of HT-4 was The thickness of the hole injection layer is 10 nm;

[0138] (2) Deposit 60 nm of HT-4 as a hole transport layer on the hole injection layer at a deposition rate of

[0139] (3) A light-emitting layer was evaporated on the hole transport layer, and the first main material P18: the second main material N3: the dye RPD-1 were co-evaporated from different evaporation sources (the first main material P18 was 100%, the proportion of the second main material N3 in the light-emitting layer was 100%, and the doping ratio of the dye RPD-1 was 3%). The thickness of the light-emitting layer was 40 nm, and the evaporation rate ratio of the first main material, the second main material and the dye was 1:1:0.03. The evaporation rate of P18 was

[0140] (4) ET-31 with a thickness of 5 nm was vacuum-deposited on the light-emitting layer as a hole blocking layer. The ET-31 evaporation rate was

[0141] (5) ET-1:100% LiQ (ET-1 is 100%, 100% is the doping ratio of LiQ) with a thickness of 25 nm was vacuum-deposited on the hole blocking layer as an electron transport layer. The ET-1 evaporation rate was

[0142] (6) Vacuum evaporate 1 nm of LiF on the electron transport layer as the electron injection layer at a rate of

[0143] (7) Vacuum-evaporating an Al layer with a thickness of 150 nm on the electron injection layer as a cathode to obtain the organic electroluminescent device.

[0144] Examples 2-20, Comparative Examples 1-11

[0145] An organic electroluminescent device, which differs from Example 1 only in that the main material of the light-emitting layer is replaced by the compound shown in Table 2, and the other structures, materials and preparation methods of the device are the same as those of Example 1; in Table 2, the mass ratio of the first main material to the second main material is 1:1.

[0146] The main materials in Comparative Examples 1-11 are as follows:

[0147]

[0148]

[0149] The organic materials used in the specific implementation of the present invention are tested, and the specific method is as follows:

[0150] (1) LUMO energy level and HOMO energy level

[0151] Cyclic voltammetry was performed on the organic materials to be tested using an electrochemical workstation. The workstation used a three-electrode system, with a platinum electrode as the working electrode, a platinum wire electrode as the counter electrode, and an Ag wire electrode as the reference electrode. 0.5 g of the sample to be tested was dissolved in 5 mL of ultra-dry tetrahydrofuran, tetra-n-butylammonium perchlorate was used as the electrolyte salt, and the test sample was protected by nitrogen. The voltage range was -2 V to 2 V, the scanning speed was 100 mV / s, and the number of scanning circles was 2 circles. On the CV curve, the peak value, i.e., the oxidation potential E ox and reduction potential E red , according to the same settings as above, test the oxidation potential E of ferrocene Fe . Calculated HOMO = -((E ox -E Fe )+4.8), LUMO=-((E red -E Fe )+4.8).

[0152] The difference between the HOMO energy level of the first host material and the HOMO energy level of the second host material (HOMO P -HOMO N ) is denoted as ΔHOMO(PN); the difference between the HOMO energy level of the hole transport layer material and the HOMO energy level of the second host material (HOMO HT -HOMO N ) is denoted as ΔHOMO(HT-N);

[0153] The difference between the LUMO energy level of the first host material and the LUMO energy level of the second host material (LUMO P -LUMO N ) is denoted as ΔLUMO(PN); the difference between the LUMO energy level of the first host material and the LUMO energy level of the material of the hole blocking layer (LUMOP -LUMO HB ) is denoted as ΔLUMO(P-HB).

[0154] (2) Triplet energy level T 1

[0155] The main material to be tested is dissolved in dimethyltetrahydrofuran solvent, and the phosphorescence spectrum of the clear rigid glass formed is measured at liquid nitrogen temperature (77K) using a Hitachi F-7000 spectrometer. On the spectrum, a tangent is drawn to the short-wave side, the value at the intersection of the tangent and the x-axis is taken, and then divided by 1240 to obtain the energy value of the triplet energy level T 1 .

[0156] The difference between the triplet energy level of the second host material and the triplet energy level of the first host material (T 1N -T 1P ) is recorded as ΔT(NP).

[0157] The test results are shown in Table 1:

[0158] Table 1

[0159]

[0160]

[0161] The performance test of the organic electroluminescent devices provided in Examples 1-20 and Comparative Examples 1-11 was carried out in the following manner:

[0162] (1) Under the same brightness, the driving voltage, current efficiency and device life of each organic electroluminescent device were measured using a PR 750 photoradiometer from Photo Research, a ST-86LA luminance meter (Beijing Normal University Photoelectric Instrument Factory) and a Keithley 4200 test system. Specifically, the voltage was increased at a rate of 0.1 V per second, and the brightness of the organic electroluminescent device was measured at 3000 cd / m 2 The voltage at this time is the driving voltage (V), and the current density at this time is measured at the same time. The ratio of brightness to current density is the current efficiency (CE, cd / A);

[0163] The test values ​​of the driving voltage and current efficiency of Example 1 are recorded as 100%, and the driving voltages and current efficiencies of other embodiments and comparative examples are the ratios of their respective test values ​​to the test values ​​of Example 1 (relative voltage, relative current efficiency). The test results are shown in Table 2.

[0164] (2) The test method for LT97 life is as follows: Use ST-86LA luminance meter (Beijing Normal University Optoelectronic Instrument Factory) at 3000cd / m 2At a brightness of , a constant current is maintained, and the time for the brightness of the organic electroluminescent device to drop to 97% of the initial brightness is measured; the test value of the LT97 life of Example 1 is recorded as 100%, and the LT97 lifespans of other embodiments and comparative examples are the ratios of their respective test values ​​to the test value of Example 1 (relative lifespan). The test results are shown in Table 2.

[0165] Table 2

[0166]

[0167]

[0168] Combining the data in Table 1 and Table 2, it can be seen that in the organic electroluminescent device provided by the present invention, the light-emitting layer adopts a specific dual-host material design. By limiting the difference range of HOMO and LUMO between the dual hosts, it can more effectively accept electrons and holes to form more excitons, and then design the triplet energy level 0<T of the first host material and the second host material. 1N -T 1P ≤0.20eV, avoiding ineffective energy transfer between the main bodies, so that the excess exciton energy can be transferred to the dye through the hole-type main body (the first main material), thereby reducing the exciton concentration without reducing the number of excitons, reducing quenching and enhancing the exciton utilization rate, and ultimately improving the device efficiency and stability. Therefore, the organic electroluminescent device provided in Examples 1-20 can reduce the driving voltage, improve the current efficiency, significantly improve the lifespan, and at the same time reduce the process cost and improve the finished product yield of the OLED display device.

[0169] Compared with the organic electroluminescent device provided by the present invention, comparative examples 1-2 use a single host material with bipolarity, and its mutually exclusive electron-donating group and electron-withdrawing group are combined on the same host, which reduces the ability of the group to gain or lose electrons, weakens the transmission rate of electron holes, and makes the performance of the device in terms of efficiency, life and voltage significantly poorer; comparative examples 3-11 are dual-host devices, but the energy levels of the two host materials cannot be effectively matched, and the excessive HOMO energy level difference causes the transition of holes to require more external energy, thereby causing the voltage to rise, and the lower energy level difference is easy to make too many holes flow in, but lack of excess electrons to recombine with them to form effective excitons, resulting in reduced efficiency. Similarly, a smaller LUMO energy level difference is easy to make excess electrons injected into the adjacent hole transport layer for recombination, so that the exciton energy cannot be retained in the light-emitting layer, thereby reducing the efficiency of the device, and various energy level mismatches cause electrons, holes, or too many or too few to affect the balance of carriers, thereby resulting in poor performance of the device.

[0170] The applicant declares that the present invention uses the above embodiments to illustrate the organic electroluminescent device of the present invention and the display device comprising the same, 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 improvement of the present invention, equivalent replacement of the raw materials selected by the present invention, addition of auxiliary components, selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

Claims

1. An organic electroluminescent device, characterized in that: The organic electroluminescent device comprises an anode, a cathode and an organic layer disposed between the anode and the cathode, the organic layer comprises a light-emitting layer, and a host material of the light-emitting layer comprises a combination of a first host material and a second host material; The first host material is an organic compound containing an electron-donating group, and its triplet energy level is T 1P , the HOMO energy level is HOMO P , the LUMO energy level is LUMO P ; The second host material is an organic compound containing an electron-withdrawing group, and its triplet energy level is T 1N , the HOMO energy level is HOMO N , the LUMO energy level is LUMO N ; 0<T 1N -T 1P ≤0.20eV,0.20eV≤HOMO P -HOMO N ≤0.70eV,0.40eV≤LUMO P -LUMO N ≤0.80eV。 2. The organic electroluminescent device according to claim 1, characterized in that: 0.30eV≤HOMO P -HOMO N ≤0.67eV; and / or, 0.55eV≤LUMO P -LUMO N ≤0.78eV.

3. The organic electroluminescent device according to claim 1, characterized in that: The organic layer further comprises a hole transport layer, and the hole transport layer is arranged between the light emitting layer and the anode; Preferably, the HOMO energy level of the material of the hole transport layer is HOMO HT , HOMO HT -HOMO N ≥0.40eV.

4. The organic electroluminescent device according to claim 1, characterized in that: The organic layer further comprises a hole blocking layer, wherein the hole blocking layer is disposed between the light emitting layer and the cathode; Preferably, the LUMO energy level of the material of the hole blocking layer is HB ,LUMO P -LUMO HB ≥0.50eV.

5. The organic electroluminescent device according to claim 1, characterized in that: The mass ratio of the first host material to the second host material is 1:(0.1-10), preferably 1:(0.6-1.5).

6. The organic electroluminescent device according to claim 1, characterized in that: The first host material has a structure as shown in Formula I: Ar2-L1-Ar1 Formula I; Wherein Ar1 is substituted or unsubstituted -* represents the connection site of the group, and the dotted line represents that ring C1 and ring C2 are optional structures; Ring C1 and Ring C2 are each independently selected from any one of a substituted or unsubstituted C6-C30 aromatic ring and a substituted or unsubstituted C3-C30 heteroaromatic ring; L1 is selected from any one of a single bond, a substituted or unsubstituted C6-C30 arylene group, and a substituted or unsubstituted C3-C30 heteroarylene group; Ar2 is selected from any one of substituted or unsubstituted C6-C30 aryl, substituted or unsubstituted C3-C30 heteroaryl, substituted or unsubstituted C6-C60 arylamino, and substituted or unsubstituted C3-C60 heteroarylamino; The substituted substituents in Ar1, Ar2, ring C1, ring C2 and L1 are each independently selected from any one of halogen, cyano, nitro, hydroxyl, amino, carboxyl, nitro, thiol, C1-C20 straight or branched alkyl, C2-C20 alkenyl, C1-C20 alkoxy, C1-C20 alkylamino, C3-C20 cycloalkyl, C2-C20 heterocycloalkyl, C6-C30 aryl, C3-C30 heteroaryl, C6-C30 aryloxy, C3-C30 heteroaryloxy, C6-C30 arylamino and C3-C30 heteroarylamino, or a combination of at least two thereof; the substituted substituents are each independently not connected to the adjacent ring structure or are connected to form a ring by chemical bonds.

7. The organic electroluminescent device according to claim 6, characterized in that: The Ar1 is selected from any one of the following substituted or unsubstituted groups: -* represents the attachment site of the group; U 1 Selected from O, S, NR 11 or CR 12 R 13 Any of the following: R 11 , R 12 , R 13 Each is independently selected from any one of hydrogen, C1-C20 straight or branched alkyl, C3-C20 cycloalkyl, C6-C30 aryl, and C3-C30 heteroaryl; the R 12 and R 13 Not connected or connected into rings by chemical bonds; Preferably, Ar2 is selected from any one of the following substituted or unsubstituted groups: -* represents the attachment site of the group; Ar 21 ,Ar 22 Each is independently selected from any one of a substituted or unsubstituted C6-C30 aryl group and a substituted or unsubstituted C3-C30 heteroaryl group; Preferably, L1 is selected from any one of a single bond, a substituted or unsubstituted C6-C20 arylene group, and more preferably a single bond, Any one of .

8. The organic electroluminescent device according to claim 6 or 7, characterized in that: The first host material is selected from any one or a combination of at least two of the following compounds P1-P102:

9. The organic electroluminescent device according to claim 1, characterized in that: The second host material has a structure as shown in Formula II: wherein A1, A2, and A3 are each independently selected from any one of a substituted or unsubstituted C6-C30 aryl group and a substituted or unsubstituted C3-C30 heteroaryl group; L2 is selected from any one of a single bond, a substituted or unsubstituted C6-C30 arylene group, and a substituted or unsubstituted C3-C30 heteroarylene group; The substituents substituted in A1, A2, A3 and L2 are each independently selected from any one of halogen, cyano, nitro, hydroxyl, amino, carboxyl, nitro, mercapto, C1-C20 straight or branched alkyl, C2-C20 alkenyl, C1-C20 alkoxy, C1-C20 alkylamino, C3-C20 cycloalkyl, C2-C20 heterocycloalkyl, C6-C30 aryl, C3-C30 heteroaryl, C6-C30 aryloxy, C3-C30 heteroaryloxy, C6-C30 arylamino and C3-C30 heteroarylamino, or a combination of at least two thereof.

10. The organic electroluminescent device according to claim 9, characterized in that: A1 is selected from any one of substituted or unsubstituted C15-C30 aryl and substituted or unsubstituted C12-C30 heteroaryl; Preferably, A1 is selected from any one of the following substituted or unsubstituted groups: -* represents the attachment site of the group; Preferably, A2 and A3 are each independently selected from any one of the following substituted or unsubstituted groups: -* represents the attachment site of the group; Preferably, L2 is selected from any one of a single bond, a substituted or unsubstituted C6-C20 arylene group, and a substituted or unsubstituted C3-C20 heteroarylene group, and more preferably a single bond, Any one of .

11. The organic electroluminescent device according to claim 8 or 9, characterized in that: The second host material is selected from any one or a combination of at least two of the compounds shown in the following N1-N55:

12. The organic electroluminescent device according to claim 1, characterized in that: The organic layer further comprises any one or a combination of at least two of a hole injection layer, an electron transport layer, and an electron injection layer; Preferably, the organic electroluminescent device comprises an anode, a hole injection layer, a hole transport layer, a light-emitting layer, a hole blocking layer, an electron transport layer, an electron injection layer and a cathode which are arranged in sequence.

13. A display device, characterized in that: The display device comprises the organic electroluminescent device according to any one of claims 1 to 12.

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