Organic light-emitting device and application thereof

Abstract

The invention provides an organic light-emitting device and application thereof. The organic light-emitting device comprises an anode, a cathode and an organic layer arranged between the anode and the cathode. The organic layer comprises a first electron blocking layer and a second electron blocking layer; the HOMO energy level of the first electron blocking layer is HOMOEB1, and the LUMO energy level of the first electron blocking layer is LUMOEB1; the HOMO energy level of the second electron blocking layer is HOMOEB2, and the LUMO energy level of the second electron blocking layer is LUMOEB2; hOMOEB2 and HOMOEB1 are greater than 0 and less than or equal to 0.10 eV; lUMOEB2-LUMOEB1 is larger than 0 and smaller than or equal to 0.50 eV, and the thickness of the second electron blocking layer is smaller than or equal to 5 nm. Through the HOMO energy level / LUMO energy level of the two electron blocking layers and the design and matching of the thickness of the second electron blocking layer, the overall performance of the device is improved, and the device has higher luminous efficiency, longer service life and lower driving voltage.

Description

Technical Field

[0001] The invention belongs to the technical field of organic electroluminescence, and in particular relates to an organic electroluminescence device and application thereof. Background Art

[0002] Organic light emission diodes (OLEDs) are usually devices with a sandwich-like laminate structure, including anode and cathode electrodes and an organic functional material layer sandwiched between the cathode and cathode electrodes. The core of an OLED device is a thin film structure containing a variety of organic functional materials. Common organic functional materials include: hole injection materials, hole transport materials, electron blocking materials, electron injection materials, electron transport materials, hole blocking materials, luminescent host materials and luminescent guest (dyes). When the OLED 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 people's ever-increasing demand for the optoelectronic performance of OLED devices and the demand for energy conservation in mobile electronic devices, it is necessary to continuously develop OLED materials with more optimized performance. In recent years, researchers have made a lot of attempts and explorations to improve device efficiency and stability, among which the most common way is to seek new materials to improve device performance. Therefore, a large number of novel organic functional materials have been developed for use in OLED devices. Although they have improved device performance to a certain extent, the replacement of new materials has limited room for improving device performance, and the materials cannot be effectively matched, which hinders the improvement of device performance.

[0004] In addition to developing new materials, researchers have also tried to optimize device performance by combining multiple materials, such as setting the electron blocking layer to be a mixture of two or more materials. This method has strict requirements on the selected materials, requiring that the thermal properties such as the evaporation temperature between the two or more materials be relatively small, and that the proportion control during the evaporation process is difficult. The mixed materials cannot be reused (the separation cost is high), and the advantages of each material will be weakened, making it difficult to improve the overall performance of the device. Other researchers have tried to set up two layers of electron blocking layers, and the HOMO energy level gradually deepens in the direction close to the light-emitting layer (the actual HOMO value decreases). This design will increase the transmission path of holes, increase the difficulty of transmission at the interface, and does not fundamentally change the carrier transmission and injection methods. The improvement of the overall performance of the device is limited, and may even sacrifice a certain performance, such as reducing efficiency and increasing voltage. Therefore, this field is in urgent need of developing organic electroluminescent devices with higher performance. Summary of the invention

[0005] In view of the shortcomings of the prior art, the purpose of the present invention is to provide an organic electroluminescent device and its application. By setting a specific double-layer electron blocking layer, the second electron blocking layer close to the light-emitting layer has a shallower HOMO energy level, so that the overall performance of the organic electroluminescent device is improved, and it has higher luminous efficiency, lower driving voltage and longer life.

[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 arranged between the anode and the cathode; the organic layer comprises a first electron blocking layer, a second electron blocking layer and a light-emitting layer; the distance between the first electron blocking layer and the light-emitting layer is greater than the distance between the second electron blocking layer and the light-emitting layer; the HOMO energy level of the first electron blocking layer is HOMO EB1 , the LUMO energy level is LUMO EB1 ; The HOMO energy level of the second electron blocking layer is HOMO EB2 , the LUMO energy level is LUMO EB2 ; 0<HOMO EB2 -HOMO EB1 ≤0.1eV; 0<LUMO EB2 -LUMO EB1 ≤0.5eV; and the thickness of the second electron blocking layer is ≤5nm.

[0008] The organic electroluminescent device provided by the present invention adopts a specific double-layer electron blocking layer design, wherein the distance between the first electron blocking layer and the light-emitting layer is greater than the distance between the second electron blocking layer and the light-emitting layer. Compared with the second electron blocking layer (referred to as "EBL2"), the first electron blocking layer (referred to as "EBL1") is closer to the anode and farther from the light-emitting layer, while the EBL2 is closer to the light-emitting layer and farther from the anode. In the specific double-layer electron blocking layer, the EBL1 close to the anode has a deeper HOMO (HOMO EB1 <HOMO EB2 ) to ensure that the luminous efficiency of the device is high; EBL2 close to the light-emitting layer has a shallower LUMO (LUMO EB2 >LUMO EB1), can better play the role of blocking electrons to ensure that the device has a longer life. Further, since EBL2 has a shallower HOMO energy level, considering that setting EBL2 will increase the potential barrier from holes to the light-emitting layer, thereby increasing the operating voltage of the device, the thickness of EBL2 is set to ≤5nm, and this inconsistent thickness forms a discontinuous film (discontinuous energy barrier), so that carriers can tunnel into the light-emitting layer, ensuring that the driving voltage / operating voltage of the device will not increase. The present invention can form a trap between EBL1 and the light-emitting layer through the design and reasonable matching of the energy levels of EBL2 and EBL1, the thickness of EBL2, to slow down the injection of holes, reduce the accumulation of holes in EBL1, improve the stability of the device, and make the device have higher luminous efficiency, longer working life and lower driving voltage, so as to achieve an overall improvement in device performance.

[0009] It should be noted that the thickness of the second electron blocking layer EBL2 ≤ 5 nm means that the maximum thickness of EBL2 is ≤ 5 nm. EBL2 is a thin layer structure. During the evaporation process, due to the thin thickness of the evaporation, it will be less uniform and less dense than other layers in the OLED device, thereby forming a discontinuous energy barrier, allowing carriers to tunnel into the light-emitting layer.

[0010] 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.

[0011] In the present invention, 0<HOMO EB2 -HOMO EB1 ≤0.10eV, HOMO EB2 -HOMO EB1 It may be 0.01 eV, 0.02 eV, 0.03 eV, 0.04 eV, 0.05 eV, 0.06 eV, 0.07 eV, 0.08 eV, or 0.09 eV, etc.

[0012] 0<LUMO EB2 -LUMO EB1 ≤0.50eV, LUMO EB2 -LUMO EB1 It may be 0.05 eV, 0.10 eV, 0.15 eV, 0.20 eV, 0.25 eV, 0.30 eV, 0.35 eV, 0.40 eV, 0.45 eV, or the like.

[0013] Preferably, the thickness of the second electron blocking layer is ≤5 nm, for example, it may be 0.5 nm, 1 nm, 1.5 nm, 2 nm, 2.5 nm, 3 nm, 3.5 nm, 4 nm or 4.5 nm, more preferably 0.5-5 nm, further preferably 1-5 nm.

[0014] Preferably, the thickness of the first electron blocking layer is 10-100 nm, for example, 15 nm, 20 nm, 25 nm, 30 nm, 35 nm, 40 nm, 45 nm, 50 nm, 60 nm, 70 nm, 80 nm or 90 nm.

[0015] Preferably, the thickness ratio of the first electron blocking layer to the second electron blocking layer is (1-40):1, for example, it can be 2:1, 3:1, 5:1, 6:1, 8:1, 10:1, 12:1, 15:1, 18:1, 20:1, 22:1, 25:1, 28:1, 30:1, 32:1, 35:1 or 38:1, further preferably (4-30):1, and further preferably (5-10):1.

[0016] Preferably, the HOMO EB1 ≤-5.20 eV, for example, it may be -5.21 eV, -5.23 eV, -5.25 eV, -5.28 eV, etc.

[0017] and / or, the HOMO EB2 ≥-5.20 eV, for example, it may be -5.19 eV, -5.18 eV, -5.15 eV, -5.12 eV, -5.10 eV, etc.

[0018] Preferably, the material of the first electron blocking layer has a structure as shown in Formula I:

[0019]

[0020] In Formula I, 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; when L1 is a single bond, it represents that the group A1 is directly connected to the N atom through a single bond.

[0021] The substituted substituents in L1 are each independently selected from any one of halogen, amino, unsubstituted or R'-substituted C1-C10 straight or branched alkyl, unsubstituted or R'-substituted C2-C10 alkenyl, unsubstituted or R'-substituted C3-C20 cycloalkyl, unsubstituted or R'-substituted C6-C30 aryl, unsubstituted or R'-substituted C3-C30 heteroaryl, unsubstituted or R'-substituted C6-C30 arylamino, and unsubstituted or R'-substituted C3-C30 heteroarylamino; the substituted substituents in L1 are each independently not connected to the adjacent ring structure or are connected to form a ring through chemical bonds.

[0022] In the present invention, "the substituted substituent is not connected to the adjacent ring structure" means that the substituent is only connected to the C atom through a single bond; "the substituted substituent is connected to the adjacent ring structure through a chemical bond to form a ring" means that the substituent is connected to the C atom through a chemical bond and is also connected to the adjacent ring through a chemical bond, thereby forming a fused ring structure. When the same description is involved below, it has the same meaning and will not be repeated one by one.

[0023] In Formula I, A1, A2, and A3 are each independently selected from any one of the following substituted or unsubstituted groups:

[0024]

[0025] Represents the attachment site of the group.

[0026] X1, X2, and X3 are each independently selected from O, S, NR 11 , CR 12 R 13 Any one of .

[0027] R 11 , R 12 , R 13 are each independently selected from any one of hydrogen, substituted or unsubstituted C1-C10 straight or branched alkyl, substituted or unsubstituted C2-C10 alkenyl, substituted or unsubstituted C3-C20 cycloalkyl, substituted or unsubstituted C6-C30 aryl, substituted or unsubstituted C3-C30 heteroaryl, substituted or unsubstituted C6-C30 arylamino, substituted or unsubstituted C3-C30 heteroarylamino; said R 12 and R 13 Not connected or connected to form a ring through chemical bonds.

[0028] In formula I, A1, A2, and A3 are each independently not connected to adjacent ring structures or are connected to form a ring through chemical bonds.

[0029] A1, A2, A3, R 11, R 12 , R 13 The substituted substituents and R' are each independently selected from any one or a combination of at least two of halogen, C1-C10 straight or branched alkyl, C2-C10 alkenyl, C3-C20 cycloalkyl, C6-C30 aryl, C3-C30 heteroaryl, C6-C30 arylamino, and C3-C30 heteroarylamino.

[0030] 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.

[0031] In the present invention, the "unsubstituted or R'substituted" group may be substituted with one substituent R' or with multiple substituents R'. When there are multiple (at least 2) substituents R', they may be the same or different substituents. When the same expressions are mentioned below, they have the same meaning. Unless otherwise specified, the selection range of R' is as shown above and will not be repeated.

[0032] In the present invention, the halogen may be fluorine, chlorine, bromine or iodine. The following descriptions involving the same have the same meaning.

[0033] 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.

[0034] 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.

[0035] In the present invention, the expression of a ring structure crossed by “—” indicates that the connection site is at any position on the ring structure that can form a bond.

[0036] In the present invention, "*" indicates the attachment point of the group.

[0037] 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.

[0038] In the present invention, “each independently” means that when there are multiple subjects, they may be the same as or different from each other.

[0039] In the present invention, the C6-C30 may be C6, C9, C10, C12, C14, C16, C18, C20, C22, C24, C26 or C28.

[0040] The C3-C30 can all be C3, C4, C5, C6, C9, C10, C12, C14, C16, C18, C20, C22, C24, C26 or C28, etc.

[0041] The C1-C10 can all be C2, C3, C4, C5, C6, C7, C8, C9, etc.

[0042] The C2-C10 can all be C3, C4, C5, C6, C7, C8, C9, etc.

[0043] 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.

[0044] 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, quaterphenyl, 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 groups in which the sub-groups are mutually fused include, but are not limited to, naphthyl, anthracenyl, phenanthrenyl, 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, It should be noted that the 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, phenylnaphthylphenyl, etc.

[0045] The C6-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, bipyridyl, phenylpyridyl, pyridylphenyl, 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 groups share two adjacent atoms fused to each other, including but not limited to: quinolyl, isoquinolyl, quinoxalinyl, quinazolinyl, benzofuranyl, benzothiophenyl, isobenzofuranyl, isobenzothiophenyl, indolyl, dibenzofuranyl, dibenzothiophenyl, carbazolyl and its derivatives (N-phenylcarbazolyl, N-naphthylcarbazolyl, benzocarbazolyl, dibenzocarbazolyl, indol and carbazolyl, azacarbazolyl, etc.), acridinyl, phenothiazinyl, phenoxazinyl, hydroacridinyl, etc. It should be noted that heteroaryl and heteroaryl connected by a single bond, aryl and heteroaryl connected by a single bond also belong to the scope of heteroaryl, such as dibenzofuranylphenyl, dibenzothiophenylphenyl, etc.

[0046] 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.

[0047] In the present invention, a specific example of the C6-C30 arylamino group is a monovalent group in which at least one hydrogen in -NH2 is replaced by the above aryl group, including but not limited to phenylamino, methylphenylamino, naphthylamino, anthracenylamino, phenanthrenylamino, biphenylamino, etc. A specific example of the C3-C30 heteroarylamino group is a monovalent group in which at least one hydrogen in -NH2 is replaced by the above heteroaryl group, including but not limited to pyridylamino, pyrimidinylamino, dibenzofuranylamino, etc.

[0048] The C1-C10 straight chain or branched alkyl group, preferably a C1-C6 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 and the like.

[0049] 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.

[0050] The C2-C10 alkenyl group contains at least one C=C, and illustratively includes but is not limited to: vinyl, propenyl, allyl, butenyl, pentenyl, hexenyl, heptenyl, octenyl, nonenyl, decenyl, butadienyl, pentadienyl, etc.

[0051] Preferably, in Formula I, when L1 is not a single bond, at least one of A2 and A3 does not contain a group

[0052]

[0053] Preferably, the material of the first electron blocking layer has a structure as shown in any one of Formula I-1, Formula I-2, and Formula I-3:

[0054]

[0055] Wherein, A1, A2, and A3 have the same defined ranges as those in Formula I.

[0056] R 21 , R 22 Each independently represents no substitution, mono-substitution to the maximum allowed substitution. 21 Indicates no substitution (R 21 is hydrogen), monosubstituted, disubstituted or trisubstituted; when R 21 When it indicates di- or tri-substitution, multiple R 21 are the same or different groups. 22 Indicates no substitution (R 22 is hydrogen), monosubstituted, disubstituted, trisubstituted, tetrasubstituted, pentasubstituted or hexasubstituted; when R 22 When it represents any of di- to hexa-substitution, multiple R 22 are the same or different groups.

[0057] R 21 , R 22Each is independently selected from any one of hydrogen, halogen, unsubstituted or R'-substituted C1-C10 straight or branched alkyl, unsubstituted or R'-substituted C2-C10 alkenyl, unsubstituted or R'-substituted C3-C20 cycloalkyl, unsubstituted or R'-substituted C6-C30 aryl, unsubstituted or R'-substituted C3-C30 heteroaryl, unsubstituted or R'-substituted C6-C30 arylamino, and unsubstituted or R'-substituted C3-C30 heteroarylamino.

[0058] A4 is selected from hydrogen, unsubstituted or R'substituted any one of the following groups:

[0059]

[0060]

[0061] Represents the attachment site of the group.

[0062] X4, X5, and X6 are each independently selected from O, S, NR 31 , CR 32 R 33 Any one of .

[0063] R 31 , R 32 , R 33 , R C , R D Each is independently selected from any one or a combination of at least two of hydrogen, C1-C10 straight or branched alkyl, C2-C10 alkenyl, C3-C20 cycloalkyl, C6-C30 aryl, C3-C30 heteroaryl, C6-C30 arylamino, and C3-C30 heteroarylamino; said R 32 and R 33 Not connected or connected to form a ring through chemical bonds.

[0064] The A4 is not connected to the adjacent ring structure or is connected to form a ring through a chemical bond.

[0065] Preferably, the A1 is not connected to the adjacent ring structure or is connected to form a ring through a chemical bond. Exemplarily, the A1 is It is connected to the adjacent ring structure by chemical bonds to form a ring, and the compound structure thus formed is Further preferably, the X6 is CR 32 R 33 , then the structure of the compound is R 21 , A2, A3, R 32 and R 33 Has the same range as above.

[0066] Preferably, the R 21 , R 22 Indicates no substitution, i.e. R 21 , R 22 For hydrogen.

[0067] Preferably, the R 11 , R 12 , R 13 Each is independently selected from any one of C1-C6 (e.g. C2, C3, C4, C5, etc.) straight chain or branched alkyl, C2-C6 (e.g. C2, C3, C4, C5, etc.) alkenyl, phenyl, biphenyl, terphenyl, naphthyl, and more preferably methyl or phenyl.

[0068] Preferably, the R 12 and R 13 Not connected or connected by chemical bonds to form a spirobifluorenyl group.

[0069] Preferably, the substituents substituted in A1, A2 and A3 are each independently selected from any one of halogen, C1-C10 (e.g., C2, C3, C4, C5, C6, C7, C8, C9, etc.) straight or branched alkyl, C2-C10 (e.g., C3, C4, C5, C6, C7, C8, C9, etc.) alkenyl, C3-C10 (e.g., C4, C5, C6, C7, C8, C9, etc.) cycloalkyl, C6-C20 (e.g., C6, C9, C10, C12, C14, C15, C16 or C18, etc.) aryl, C3-C20 (e.g., C4, C5, C6, C9, C10, C12, C14, C15, C16 or C18, etc.) heteroaryl, more preferably C1-C6 straight or branched alkyl, further preferably methyl, ethyl, Any one of .

[0070] Preferably, the R 31 , R 32 , R 33 Each is independently selected from any one of C1-C6 (e.g. C2, C3, C4, C5, etc.) straight chain or branched alkyl, C2-C6 (e.g. C2, C3, C4, C5, etc.) alkenyl, phenyl, biphenyl, terphenyl, naphthyl, and more preferably methyl or phenyl.

[0071] Preferably, the R 32 and R 33 Not connected or connected by chemical bonds to form a spirobifluorenyl group.

[0072] Preferably, R' in A4 is independently selected from any one of halogen, C1-C10 (e.g., C2, C3, C4, C5, C6, C7, C8, C9, etc.) straight or branched alkyl, C2-C10 (e.g., C3, C4, C5, C6, C7, C8, C9, etc.) alkenyl, C3-C10 (e.g., C4, C5, C6, C7, C8, C9, etc.) cycloalkyl, C6-C20 (e.g., C6, C9, C10, C12, C14, C15, C16, or C18, etc.) aryl, C3-C20 (e.g., C4, C5, C6, C9, C10, C12, C14, C15, C16, or C18, etc.) heteroaryl, more preferably C1-C6 straight or branched alkyl, further preferably methyl, ethyl, Any one of .

[0073] Preferably, A1, A2, A3, and A4 are each independently selected from any one of the following groups:

[0074]

[0075]

[0076] Represents the attachment site of the group.

[0077] Preferably, the material of the first electron blocking layer is selected from any one or a combination of at least two of the compounds shown in Z1-Z120:

[0078]

[0079]

[0080]

[0081]

[0082]

[0083] Preferably, the material of the second electron blocking layer has a structure as shown in Formula II:

[0084]

[0085] In formula II, R1, R2, R3, and R4 are each independently selected from any one of substituted or unsubstituted C1-C10 straight or branched alkyl, substituted or unsubstituted C2-C10 alkenyl, substituted or unsubstituted C3-C20 cycloalkyl, and substituted or unsubstituted C6-C30 aryl; R1 and R2 are not connected or are connected to form a ring through a chemical bond; R3 and R4 are not connected or are connected to form a ring through a chemical bond.

[0086] In formula II, L2, L3, and L4 are each independently 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 L4 is a single bond, it represents that the group Ar is directly connected to the N atom through a single bond; when L2 is a single bond, it represents that the N atom is directly connected to the C atom of the benzene ring in the fluorene group through a single bond; the same is true for L3, and for the sake of brevity, it will not be repeated.

[0087] In Formula II, Ar is selected from any one of a substituted or unsubstituted C6-C30 aryl group and a substituted or unsubstituted C3-C30 heteroaryl group.

[0088] The substituents substituted in R1, R2, R3, R4, L2, L3, L4 and Ar are each independently selected from any one of halogen, C1-C10 straight or branched alkyl, C2-C10 alkenyl, C3-C20 cycloalkyl, C6-C30 aryl, C3-C30 heteroaryl, C6-C30 arylamino and C3-C30 heteroarylamino, or a combination of at least two thereof.

[0089] In formula II, R5, R6, R7, and R8 each independently represent unsubstituted, monosubstituted to the maximum allowable substitution; specifically, R5 represents unsubstituted (R5 is hydrogen), monosubstituted, disubstituted or trisubstituted; when R5 represents disubstituted or trisubstituted, multiple R5s are the same or different groups; R6 represents unsubstituted (R5 is hydrogen), monosubstituted, disubstituted, trisubstituted or tetrasubstituted; when R6 represents disubstituted, trisubstituted or tetrasubstituted, multiple R6s are the same or different groups; R7 is the same as R5, and R8 is the same as R6. For the sake of brevity, they are not repeated here.

[0090] R5, R6, R7, and R8 are each independently selected from any one of hydrogen, halogen, C1-C10 straight or branched alkyl, C2-C10 alkenyl, C3-C20 cycloalkyl, C6-C30 aryl, C3-C30 heteroaryl, C6-C30 arylamino, and C3-C30 heteroarylamino, or a combination of at least two thereof.

[0091] Preferably, L4 is biphenylene

[0092] Preferably, the material of the second electron blocking layer has a structure as shown in Formula II-1 or Formula II-2:

[0093]

[0094] Among them, R1, R2, R3, R4, R5, R6, R7, R8, L2, L3, and Ar have the same limited ranges as Formula II.

[0095] Preferably, L2 and L3 are each independently a single bond or a phenylene group. A single bond is more preferred.

[0096] Preferably, R1, R2, R3, and R4 are each independently selected from any one of C1-C6 (eg, C2, C3, C4, C5, etc.) straight chain or branched alkyl, phenyl, biphenyl, terphenyl or naphthyl, and methyl or phenyl is more preferred.

[0097] Preferably, R1 and R2 are not connected or are connected through a chemical bond to form a spirobifluorenyl group; and / or, R3 and R4 are not connected or are connected through a chemical bond to form a spirobifluorenyl group.

[0098] Preferably, R5, R6, R7, and R8 represent unsubstituted or monosubstituted, and more preferably unsubstituted.

[0099] Preferably, R5, R6, R7, and R8 are each independently selected from any one of hydrogen, C1-C6 (such as C2, C3, C4, C5, etc.) straight chain or branched alkyl, and phenyl, and more preferably hydrogen.

[0100] Preferably, Ar is selected from any one of C6-C20 (e.g., C6, C9, C10, C12, C14, C15, C16 or C18, etc.) aryl, C3-C20 (e.g., C4, C5, C6, C9, C10, C12, C14, C15, C16 or C18, etc.) heteroaryl, and is further preferably any one of phenyl, biphenyl, terphenyl, naphthyl, dimethylfluorenyl, dibenzofuranyl, dibenzothiophenyl, carbazolyl and N-phenylcarbazolyl.

[0101] Preferably, Ar is selected from Any one of .

[0102] Preferably, the material of the second electron blocking layer is selected from any one or a combination of at least two of the compounds shown in P1-P26:

[0103]

[0104] As a preferred technical solution of the present invention, the material of the first electron blocking layer is selected from any one of Z1, Z2, Z4, Z28, Z34, Z65, and Z100, and the material of the second electron blocking layer is selected from any one of P1, P5, P12, P13, P20, and P23.

[0105] Preferably, the glass transition temperature (Tg) of the material of the second electron blocking layer is ≥130°C, for example, it may be 132°C, 135°C, 138°C, 140°C, 142°C, 145°C, 148°C, 150°C, 152°C, 155°C, 158°C or 160°C, etc.

[0106] Preferably, the organic layer further comprises any one of a hole injection layer, a hole transport layer, an electron transport layer, and an electron injection layer, or a combination of at least two of them.

[0107] Preferably, the organic electroluminescent device comprises an anode, a hole injection layer, a hole transport layer, a first electron blocking layer, a second electron blocking layer, a light emitting layer, an electron transport layer, an electron injection layer and a cathode which are arranged in sequence.

[0108] In a specific technical solution, the hole transport layer (HTL), the first electron blocking layer (EBL1), the second electron blocking layer (EBL2), and the light emitting layer (EML) are arranged in sequence, and the energy level relationship diagram is as shown in FIG. Figure 2 shown.

[0109] 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 used as a display may be provided with a thin film transistor (TFT). The substrate of the present invention is preferably a rigid glass substrate.

[0110] In a preferred technical solution, the anode can be formed by sputtering or depositing a material used as an anode 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, laminates formed by alternating metals and metals, laminates 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 in the present invention is preferably ITO.

[0111] 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.

[0112] Preferably, the preparation method includes: cleaning, drying, pre-treating the substrate, entering the chamber, and vacuum depositing the hole injection layer, hole transport layer, electron blocking layer, light-emitting layer, electron transport layer, electron injection layer, cathode, etc. of each light-emitting sub-unit in sequence.

[0113] 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.

[0114]

[0115] 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.

[0116]

[0117]

[0118]

[0119] The light-emitting layer includes a light-emitting dye (i.e., dopant) that can emit light of different wavelength spectra, and may also include a host material (Host). The light-emitting layer may be a monochrome light-emitting layer that emits a single color such as red, green, and blue. A plurality of monochrome light-emitting layers of different colors may be arranged in a plane according to a pixel pattern, or may be stacked together to form a color light-emitting layer. When light-emitting layers of different colors are stacked together, they may be separated from each other or may be connected to each other. The light-emitting layer may also be a single color light-emitting layer that can simultaneously emit different colors such as red, green, and blue.

[0120] According to different technologies, the light-emitting layer material can be made of different materials such as fluorescent electroluminescent materials, phosphorescent electroluminescent materials, and thermally activated delayed fluorescent materials. In an OLED device, a single light-emitting technology can be used, or a combination of multiple different light-emitting technologies can be used. These different light-emitting materials classified by technology can emit light of the same color or different colors.

[0121] In a preferred technical solution of the present invention, the light-emitting layer adopts phosphorescent luminescence technology, and the host material is selected from, but not limited to, one or more combinations of PH-1 to PH-85.

[0122]

[0123]

[0124]

[0125]

[0126] In one aspect of the present invention, the light-emitting layer adopts phosphorescent electroluminescence technology, and the doping material (phosphorescent doping material, also known as 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.

[0127]

[0128] Where D is deuterium.

[0129] In a preferred technical solution, the light-emitting layer adopts phosphorescent electroluminescence technology, and the doping material of the light-emitting layer 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.

[0130]

[0131]

[0132] 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.

[0133]

[0134]

[0135]

[0136]

[0137] 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, Li2O, Cs2CO3, BaO, Na, Li, Ca, Mg or Yb.

[0138] 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.

[0139] In a second aspect, the present invention provides a display device, comprising the organic electroluminescent device as described in the first aspect.

[0140] Compared with the prior art, the present invention has the following beneficial effects:

[0141] In the organic electroluminescent device provided by the present invention, a special design of a double-layer electron blocking layer is adopted. Through the design and reasonable matching of the HOMO energy level / LUMO energy level of the first electron blocking layer and the second electron blocking layer, on the one hand, the advantage of the second electron blocking layer in blocking excitons and electrons is utilized to improve the stability of the device. On the other hand, the advantage of the first electron blocking layer and the light-emitting layer having a small HOMO barrier and being easy to inject holes to improve the efficiency is effectively utilized without causing an increase in voltage, thereby ultimately achieving an improvement in the overall performance of the device, so that the device has higher luminous efficiency, longer service life and lower driving voltage. BRIEF DESCRIPTION OF THE DRAWINGS

[0142] Figure 1 A schematic diagram of the structure of an organic electroluminescent device provided in one specific embodiment of the present invention;

[0143] Among them, 1-anode, 2-hole injection layer, 3-hole transport layer, 41-first electron blocking layer, 42-second electron blocking layer, 5-light-emitting layer, 6-electron transport layer, 7-electron injection layer, 8-cathode;

[0144] Figure 2 This is a schematic diagram of energy level relationships provided in a technical solution of the present invention. DETAILED DESCRIPTION

[0145] 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.

[0146] In a specific embodiment, the material of the first electron blocking layer (EBL1) has a structure as shown in Formula I, and the material of the second electron blocking layer (EBL2) has a structure as shown in Formula II; the aforementioned materials can be synthesized by methods disclosed in the prior art, for example, reference can be made to the contents disclosed in the prior art CN114759148A.

[0147] Example 1

[0148] An organic electroluminescent device, the structural schematic diagram of which is as follows Figure 1 As shown, it includes an anode 1 (ITO / Ag / ITO), a hole injection layer 2, a hole transport layer 3, a first electron blocking layer 41, a second electron blocking layer 42, a light emitting 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 thereof is as follows:

[0149] (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;

[0150] (2) Deposit 60 nm of HT-4 as a hole transport layer on the hole injection layer at a deposition rate of

[0151] (3) Compound Z1 was evaporated on the hole transport layer as the first electron blocking layer EBL1 at a rate of Thickness: 30nm;

[0152] (4) Compound P5 is evaporated on the first electron blocking layer EBL1 to form the second electron blocking layer EBL2 at a deposition rate of Thickness: 5nm;

[0153] (5) A light-emitting layer is evaporated on the second electron blocking layer EBL2, and the first host material PH-61: the second host material PH-3: the dye GPD-12 are co-evaporated from different evaporation sources (the first host material PH-61 is 100%, the doping ratio of the second host material PH-3 in the light-emitting layer is 100%, and the doping ratio of the dye GPD-12 is 20%). The thickness of the light-emitting layer is 40 nm, and the evaporation rate ratio of the first host material, the second host material and the dye is 1:1:0.2. The evaporation rate of PH-61 is

[0154] (6) ET-69:100% ET-57 (ET-69 is 100%, and 100% is the doping ratio of ET-57) with a thickness of 30 nm was vacuum-deposited on the light-emitting layer as an electron transport layer. The ET-69 evaporation rate was

[0155] (7) Vacuum evaporate 1 nm of LiF on the electron transport layer as the electron injection layer at a rate of

[0156] (8) 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.

[0157] Examples 2-14, Comparative Examples 1-9

[0158] An organic electroluminescent device, which differs from Example 1 only in that at least one of the EBL1 material, the EBL2 material, and the thickness of EBL2 is different, as shown in Table 2; the other structures, materials, and preparation methods of the device are the same as those of Example 1.

[0159] Among them, EBL1 and EBL2 in Comparative Example 2 are the same material, both are pre-mixed D2-1+P12 (the mass ratio of the two compounds is 1:1); EBL1 and EBL2 in Comparative Example 3 are the same material, both are compound Z1; EBL1 and EBL2 in Comparative Example 4 are the same material, both are compound P5; EBL1 and EBL2 in Comparative Example 7 are the same material, both are pre-mixed Z1+P5 (the mass ratio of the two compounds is 1:1); in Comparative Examples 2, 3, 4 and 7, EBL1 and EBL2 are the same material, and the total thickness of EBL1 and EBL2 is 35nm (EBL1 is 30nm, and EBL2 is 5nm).

[0160] The electron blocking layer materials in Comparative Examples 1-9 are as follows:

[0161]

[0162]

[0163] The electron blocking layer materials used in the examples and comparative examples were tested in the following specific methods:

[0164] (1) LUMO energy level and HOMO energy level

[0165] The main material to be tested was tested by cyclic voltammetry 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).

[0166] The difference between the HOMO energy level of EBL2 material and the HOMO energy level of EBL1 material (HOMO EB2 -HOMO EB1 ) is denoted as ΔHOMO; the LUMO energy level of the EBL2 material is LUMO EB2 The LUMO energy level of EBL1 material is EB1 The difference (LUMO EB2 -LUMO EB1 ) is denoted as ΔLUMO.

[0167] (2) Glass transition temperature Tg

[0168] The Tg of the electron blocking layer material is obtained by differential scanning calorimetry (DSC). The sample is ground into a uniform powder and dried in a vacuum oven at (100±10)℃ for 30min. Weigh 10mg and take 3 samples in parallel. Before heating, pre-clean with nitrogen for 5min. Start heating at a rate of 20℃ / min and record. After heating the sample dish to the set heating end temperature, stop heating and record the DSC curve (the heating end temperature is 50℃ lower than the temperature of 5% thermal weight loss of the sample). Then the sample is cooled rapidly and quenched to solidification. Then heat it for the second time at a rate of 5℃ / min and record it, heating to (30±0.5)℃ higher than the extrapolated end temperature Tetg. Cool the instrument to room temperature. On the second heating curve, take the intersection of the initial baseline extrapolation and the tangent at the inflection point of the curve, which is the glass transition temperature.

[0169] The test results are shown in Table 1, where the Tg in Table 1 is the Tg of the EBL2 material:

[0170] Table 1

[0171]

[0172]

[0173] In Table 1, "D2-1+P12" corresponds to Comparative Example 2. Since EBL1 and EBL2 in Comparative Example 2 both use pre-mixed D2-1+P12, the materials of the two electron blocking layers are the same, so the energy level difference is recorded as "0"; Tg is the test result of the mixture of the two.

[0174] The performance test of the organic electroluminescent devices provided in Examples 1-14 and Comparative Examples 1-9 was carried out in the following manner:

[0175] (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 10,000 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);

[0176] 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.

[0177] (2) The test method for LT97 life is as follows: Use ST-86LA luminance meter (Beijing Normal University Optoelectronic Instrument Factory) at 3000cd / m 2 At 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.

[0178] Table 2

[0179]

[0180]

[0181] Combining the data in Table 1 and Table 2, it can be seen that in the organic electroluminescent device provided by the present invention, a specific design of a double-layer electron blocking layer is adopted, the HOMO energy level of the second electron blocking layer EBL2 is greater than the HOMO energy level of the first electron blocking layer EBL1 material, and the difference between the two is ΔHOMO≤0.10eV, the LUMO energy level of the second electron blocking layer EBL2 material is greater than the LUMO energy level of the first electron blocking layer EBL1 material, and the difference between the two is ΔLUMO≤0.50eV, and the thickness of EBL2 is set to ≤5nm, so as to give play to the advantages of low voltage and high efficiency of EBL1. On the one hand, it can effectively block excitons and electrons for EBL1 and improve the stability of the device. On the other hand, the thinner EBL2 will not form a continuous and dense film, that is, it will not cause an increase in voltage, thereby improving the overall performance of the device. If the thickness of EBL2 is too thick (Comparative Examples 5-6), the voltage will increase; if a single electron blocking layer material is used (Comparative Examples 3-4), or a double-layer electron blocking layer opposite to the energy level requirement of the present invention is used (Comparative Example 1), or any one of the LUMO / HOMO energy levels of the double-layer electron blocking layer does not conform to the design of the present invention (Comparative Examples 8-9), a certain performance of the device will be sacrificed, causing the voltage of the device to increase, or the efficiency or life performance to decrease; if a premixed material is used, that is, the two are mixed (Comparative Example 2, Comparative Example 7), the respective advantages of the two will be weakened, and it will be difficult to achieve an overall performance improvement.

[0182] The applicant declares that the present invention illustrates the organic electroluminescent device and its application through the above-mentioned embodiments, but the present invention is not limited to the above-mentioned process steps, that is, it does not mean that the present invention must rely on the above-mentioned 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 arranged between the anode and the cathode; the organic layer comprises a first electron blocking layer, a second electron blocking layer and a light-emitting layer; the distance between the first electron blocking layer and the light-emitting layer is greater than the distance between the second electron blocking layer and the light-emitting layer; The HOMO energy level of the first electron blocking layer is HOMO EB1 , the LUMO energy level is LUMO EB1 ; The HOMO energy level of the second electron blocking layer is HOMO EB2 , the LUMO energy level is LUMO EB2 ; 0<HOMO EB2 -HOMO EB1 ≤0.10eV; 0<LIGHT EB2 -LIGHT EB1 ≤0.50eV; The thickness of the second electron blocking layer is ≤5 nm.

2. The organic electroluminescent device according to claim 1, characterized in that: The thickness of the second electron blocking layer is 0.5-5 nm; Preferably, the thickness of the first electron blocking layer is 10-100 nm.

3. The organic electroluminescent device according to claim 1, characterized in that: The thickness ratio of the first electron blocking layer to the second electron blocking layer is (1-40):1, preferably (4-30):1, and further preferably (5-10):

1.

4. The organic electroluminescent device according to claim 1, characterized in that: The material of the first electron blocking layer has a structure as shown in Formula I: Wherein, 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; The substituents substituted in L1 are each independently selected from any one of halogen, amino, unsubstituted or R'-substituted C1-C10 straight or branched alkyl, unsubstituted or R'-substituted C2-C10 alkenyl, unsubstituted or R'-substituted C3-C20 cycloalkyl, unsubstituted or R'-substituted C6-C30 aryl, unsubstituted or R'-substituted C3-C30 heteroaryl, unsubstituted or R'-substituted C6-C30 arylamino, and unsubstituted or R'-substituted C3-C30 heteroarylamino; the substituents substituted in L1 are each independently not connected to the adjacent ring structure or connected to form a ring through a chemical bond; A1, A2, A3 are each independently selected from any one of the following substituted or unsubstituted groups: -* represents the attachment site of the group; X1, X2, and X3 are each independently selected from O, S, NR 11 , CR 12 R 13 Any of the following: R 11 , R 12 , R 13 are each independently selected from any one of hydrogen, substituted or unsubstituted C1-C10 straight or branched alkyl, substituted or unsubstituted C2-C10 alkenyl, substituted or unsubstituted C3-C20 cycloalkyl, substituted or unsubstituted C6-C30 aryl, substituted or unsubstituted C3-C30 heteroaryl, substituted or unsubstituted C6-C30 arylamino, substituted or unsubstituted C3-C30 heteroarylamino; said R 12 and R 13 Not connected or connected into rings by chemical bonds; A1, A2, and A3 are each independently not connected to adjacent ring structures or connected to form a ring through chemical bonds; A1, A2, A3, R 11 , R 12 , R 13 The substituted substituents and R' are each independently selected from any one or a combination of at least two of halogen, C1-C10 straight or branched alkyl, C2-C10 alkenyl, C3-C20 cycloalkyl, C6-C30 aryl, C3-C30 heteroaryl, C6-C30 arylamino, and C3-C30 heteroarylamino.

5. The organic electroluminescent device according to claim 4, characterized in that: The material of the first electron blocking layer has a structure as shown in any one of Formula I-1, Formula I-2, and Formula I-3: Wherein, A1, A2, and A3 have the same defined ranges as in Formula I; R 21 , R 22 Each independently represents no substitution, monosubstitution to the maximum allowed substitution; R 21 , R 22 Each is independently selected from any one of hydrogen, halogen, unsubstituted or R'substituted C1-C10 straight or branched alkyl, unsubstituted or R'substituted C2-C10 alkenyl, unsubstituted or R'substituted C3-C20 cycloalkyl, unsubstituted or R'substituted C6-C30 aryl, unsubstituted or R'substituted C3-C30 heteroaryl, unsubstituted or R'substituted C6-C30 arylamino, and unsubstituted or R'substituted C3-C30 heteroarylamino; A4 is selected from hydrogen, unsubstituted or R'substituted any one of the following groups: ——* represents the attachment site of the group; X4, X5, and X6 are each independently selected from O, S, NR 31 , CR 32 R 33 Any of the following: R 31 , R 32 , R 33 , R C , R D Each is independently selected from any one or a combination of at least two of hydrogen, C1-C10 straight or branched alkyl, C2-C10 alkenyl, C3-C20 cycloalkyl, C6-C30 aryl, C3-C30 heteroaryl, C6-C30 arylamino, and C3-C30 heteroarylamino; said R 32 and R 33 Not connected or connected into rings by chemical bonds; The A4 is not connected to the adjacent ring structure or is connected to form a ring through a chemical bond.

6. The organic electroluminescent device according to claim 5, characterized in that: The A1, A2, A3, and A4 are each independently selected from any one of the following groups: ——* represents the attachment site of the group.

7. The organic electroluminescent device according to claim 4, characterized in that: The material of the first electron blocking layer is selected from any one or a combination of at least two of the compounds shown in Z1-Z120:

8. The organic electroluminescent device according to claim 1, characterized in that: The material of the second electron blocking layer has a structure as shown in Formula II: Wherein, R1, R2, R3, and R4 are each independently selected from any one of substituted or unsubstituted C1-C10 straight or branched alkyl, substituted or unsubstituted C2-C10 alkenyl, substituted or unsubstituted C3-C20 cycloalkyl, and substituted or unsubstituted C6-C30 aryl; R1 and R2 are not connected or connected to form a ring through a chemical bond; R3 and R4 are not connected or connected to form a ring through a chemical bond; L2, L3, and L4 are each independently 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; Ar is selected from any one of a substituted or unsubstituted C6-C30 aryl group and a substituted or unsubstituted C3-C30 heteroaryl group; The substituents substituted in R1, R2, R3, R4, L2, L3, L4, and Ar are each independently selected from any one or a combination of at least two of halogen, C1-C10 straight or branched alkyl, C2-C10 alkenyl, C3-C20 cycloalkyl, C6-C30 aryl, C3-C30 heteroaryl, C6-C30 arylamino, and C3-C30 heteroarylamino; R5, R6, R7, and R8 each independently represent unsubstituted, monosubstituted to the maximum permissible substitution; R5, R6, R7, and R8 are each independently selected from any one of hydrogen, halogen, C1-C10 straight or branched alkyl, C2-C10 alkenyl, C3-C20 cycloalkyl, C6-C30 aryl, C3-C30 heteroaryl, C6-C30 arylamino, and C3-C30 heteroarylamino, or a combination of at least two thereof.

9. The organic electroluminescent device according to claim 8, characterized in that: The material of the second electron blocking layer has a structure as shown in Formula II-1 or Formula II-2: Among them, R1, R2, R3, R4, R5, R6, R7, R8, L2, L3, and Ar have the same limited ranges as Formula II.

10. The organic electroluminescent device according to claim 8 or 9, characterized in that: R1, R2, R3, and R4 are each independently selected from any one of a C1-C6 straight or branched alkyl group, a phenyl group, a biphenyl group, a terphenyl group, or a naphthyl group, preferably a methyl group or a phenyl group; Preferably, Ar is selected from Any one of .

11. The organic electroluminescent device according to claim 8, characterized in that: The material of the second electron blocking layer is selected from any one or a combination of at least two of the compounds shown in P1-P26:

12. The organic electroluminescent device according to claim 1, characterized in that: The glass transition temperature of the material of the second electron blocking layer is ≥130°C.

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

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

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