Exciplex and electroluminescent application thereof
Patent Information
- Application Number
- CN202411375391.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-29
- Publication Date
- 2025-02-14
AI Technical Summary
In the existing OLED display panels, the light-on voltage and driving voltage of the blue light device are relatively high, resulting in increased power consumption and low gray-scale crosstalk problem is more prominent.
Using an excitation composite composed of P-type and N-type materials, the P-type material contains carbazole or indole carbazole groups, the N-type material contains triazine groups, and anthracene groups are introduced into the structure to increase the triple State-Triple state annihilation (TTA) occurs. The excitation composite is laminated or premixed to form a mixed film layer for constituting the light emitting layer of the OLED.
By reducing the illumination voltage and driving voltage, improving current efficiency and life, the performance of OLED display panels is significantly improved, especially in the application of Blu-ray devices.
Smart Images
Figure BDA0005068719030000011 
Figure BDA0005068719030000021 
Figure BDA0005068719030000023
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of organic electroluminescent materials, and in particular to an excimer complex and its electroluminescent application. Background Art
[0002] As a new generation of display technology, organic electroluminescent materials (OLEDs) have the advantages of ultra-thinness, self-luminescence, wide viewing angle, fast response, high luminous efficiency, good temperature adaptability, simple production process, low driving voltage and low energy consumption. They have been widely used in industries such as flat panel displays, flexible displays, solid-state lighting and automotive displays.
[0003] Organic electroluminescent materials can be divided into electrofluorescence and electrophosphorescence according to the luminescence mechanism. Fluorescence is the radiation decay transition of singlet excitons. The internal quantum efficiency of fluorescent materials does not exceed the limit of 25%, and the external quantum efficiency is generally less than 5%. However, triplet-triplet annihilation (TTA) can occur in fluorescent materials, converting two triplet excitons into one singlet exciton, and the internal quantum efficiency can theoretically reach 62.5%. The turn-on voltage of TTA-type blue fluorescent devices is generally close to the band gap of blue light, which is much higher than the turn-on voltage of red and green light, causing low grayscale crosstalk problems. In addition, the driving voltage of blue light devices is also the highest among the red, green and blue devices, which makes the power consumption of OLED display panels higher. Therefore, reducing the turn-on voltage and driving voltage of blue light devices is the key research direction of researchers. Summary of the invention
[0004] In view of this, the technical problem to be solved by the present invention is to provide an exciplex and its electroluminescence application, which can be applied to the field of organic electroluminescence.
[0005] The present invention provides an exciplex, comprising a P-type material and an N-type material;
[0006] The P-type material has a structure shown in Formula I:
[0007]
[0008] Wherein, A1 and A2 are independently selected from H or any of the following structures, and A1 and A2 are not H at the same time:
[0009]
[0010] R1 is selected from hydrogen, substituted or unsubstituted aryl, heteroaryl or alkyl;
[0011] X is selected from O or S;
[0012] R2, R3, R4, R5, and R6 are independently selected from hydrogen, deuterium, substituted or unsubstituted aryl, heteroaryl, or alkyl;
[0013] L is selected from a single bond, a substituted or unsubstituted arylene or heteroarylene;
[0014] The N-type material has a structure shown in Formula II:
[0015]
[0016] Among them, R7, R8, R9, R 10 are independently selected from hydrogen, deuterium, substituted or unsubstituted aryl, heteroaryl or alkyl;
[0017] L2 is selected from a single bond, a substituted or unsubstituted arylene or heteroarylene;
[0018] R 11 -R 18 are independently selected from hydrogen, deuterium, substituted or unsubstituted aryl, heteroaryl or alkyl;
[0019] Or the P-type material has a structure shown in Formula III:
[0020]
[0021] wherein Rx is selected from substituted or unsubstituted aryl or heteroaryl;
[0022] L3 is selected from a single bond, a substituted or unsubstituted arylene or heteroarylene;
[0023] A is selected from any of the following structures:
[0024]
[0025] R1 is selected from hydrogen, substituted or unsubstituted aryl, heteroaryl or alkyl;
[0026] X is selected from O or S;
[0027] R4, R5, R6 are independently selected from hydrogen, substituted or unsubstituted aryl, heteroaryl or alkyl;
[0028] R 19 -R 26 are independently selected from hydrogen, deuterium, substituted or unsubstituted aryl, heteroaryl or alkyl;
[0029] The N-type material has a structure shown in Formula IV:
[0030]
[0031] R 27 , R 28 , R 29 independently selected from substituted or unsubstituted aryl, heteroaryl or alkyl;
[0032] R 30 is selected from substituted or unsubstituted aryl, heteroaryl or alkyl;
[0033] L4 is selected from a single bond, a substituted or unsubstituted aryl or heteroaryl group;
[0034] Y is O or S;
[0035] n is any integer from 1 to 7;
[0036] * indicates the connection location;
[0037] Indicates the connection location.
[0038] The present invention provides an organic electroluminescent device, comprising a light-emitting layer, wherein the main material of the light-emitting layer comprises the above-mentioned exciplex.
[0039] The present invention provides a display panel, comprising the above-mentioned organic electroluminescent device;
[0040] The organic electroluminescent device is a single-layer organic electroluminescent device or a multi-layer organic electroluminescent device.
[0041] Compared with the prior art, the present invention provides an exciplex. The exciplex is composed of P-type and N-type materials, the P-type material contains a carbazole or indolecarbazole group, and the N-type material contains a triazine group. In order to increase the proportion of TTA occurring in the exciplex, the present invention further introduces an anthracene group into the structure of the P-type material or the N-type material. The P-type and N-type materials are mixed to form a mixed film layer or the thin films of the P-type material and the N-type material are stacked to form an exciplex. The singlet and triplet energies of the exciplex are close, and the narrow-bandgap exciplex is directly electrically excited. The triplet excitons formed are then transferred to the main material, and TTA occurs on the main material to generate singlet excitons, emitting blue light. By converting the low-energy triplet state into a high-energy singlet state through TTA, it is possible to reduce the turn-on voltage and driving voltage, improve the current efficiency and life, and can be well applied in the field of electroluminescence technology. BRIEF DESCRIPTION OF THE DRAWINGS
[0042] Figure 1 Schematic diagram of the device structure of Example 1. DETAILED DESCRIPTION
[0043] The invention provides an exciplex, comprising a P-type material and an N-type material.
[0044] The P-type material refers to a material that lacks electrons at the PN junction and conducts electricity mainly through holes; the N-type material refers to a material that has excess electrons at the PN junction and conducts electricity mainly through electrons.
[0045] Optionally, the difference in absolute value between the HOMO energy level of the P-type material and the LUMO energy level of the N-type material is less than 2.4 eV.
[0046] The P-type material has a structure shown in Formula I:
[0047]
[0048] Wherein, A1 and A2 are independently selected from H or any of the following structures, and A1 and A2 are not H at the same time:
[0049]
[0050] *Indicates the connection location.
[0051] Preferably, any one of A1 and A2 is selected from H, and the other is selected from any of the above structures.
[0052] R1 is selected from hydrogen, substituted or unsubstituted aryl, heteroaryl or alkyl.
[0053] Preferably, R1 is selected from hydrogen, substituted or unsubstituted monocyclic aromatic groups, fused aromatic groups of 2 to 3 monocyclic aromatic groups, monocyclic heteroaromatic groups, fused heteroaromatic groups of 2 to 3 monocyclic heteroaromatic groups, fused heteroaromatic groups of 2 to 3 monocyclic aromatic groups and monocyclic heteroaromatic groups, and C1 to C10 alkyl groups.
[0054] The monocyclic aryl group is preferably a phenyl group.
[0055] The heteroatoms of the heteroaryl group include one or more of N, O, and S.
[0056] The monocyclic heteroaryl group is preferably a five-membered or six-membered heteroaryl group.
[0057] More preferably, R1 is selected from hydrogen, substituted or unsubstituted phenyl, naphthyl, anthracenyl, phenanthryl, pyridyl, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl or tert-butyl.
[0058] The substituent group of R1 is selected from one or more of deuterium, halogen, nitro, cyano and phenyl.
[0059] In some specific embodiments of the present invention, the R1 is selected from hydrogen, phenyl, biphenyl, naphthyl or methyl.
[0060] The X is selected from O or S.
[0061] The R2, R3, R4, R5 and R6 are independently selected from hydrogen, deuterium, substituted or unsubstituted aryl, heteroaryl or alkyl.
[0062] Preferably, R2, R3, R4, R5, and R6 are independently selected from hydrogen, deuterium, substituted or unsubstituted monocyclic aromatic groups, fused aromatic groups of 2 to 3 monocyclic aromatic groups, monocyclic heteroaromatic groups, fused heteroaromatic groups of 2 to 3 monocyclic heteroaromatic groups, heteroaromatic groups of 2 to 3 monocyclic aromatic groups and monocyclic heteroaromatic groups, and C1 to C10 alkyl groups.
[0063] Said R2 and R3 are preferably independently hydrogen, deuterium, phenyl, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl or tert-butyl.
[0064] The R4, R5, and R6 are preferably independently hydrogen, deuterium, phenyl, naphthyl, biphenyl, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, or tert-butyl.
[0065] More preferably, R4 and R5 are independently hydrogen, deuterium or methyl.
[0066] More preferably, R6 is hydrogen, deuterium, phenyl, naphthyl, biphenyl or methyl.
[0067] L is selected from a single bond, a substituted or unsubstituted arylene group or a heteroarylene group.
[0068] Preferably, L is selected from a single bond, a substituted or unsubstituted monocyclic arylene group, a condensed arylene group of 2 to 3 monocyclic aryl groups, a monocyclic heteroarylene group, a heteroarylene group of 2 to 3 monocyclic heteroaryl groups, a heteroarylene group of 2 to 3 monocyclic aryl groups and a heteroarylene group of 2 to 3 monocyclic heteroaryl groups;
[0069] The monocyclic aryl group is preferably a phenyl group.
[0070] The heteroatoms of the heteroaryl group include one or more of N, O, and S.
[0071] The heteroaryl group is preferably a five-membered or six-membered heteroaryl group.
[0072] The above-mentioned L is preferably a single bond, a substituted or unsubstituted phenylene group, a naphthylene group or a pyridylene group.
[0073] Preferably, the substituent groups of R2, R3, R4, R5, R6 and L are independently selected from one or more of deuterium, halogen, nitro, cyano and phenyl.
[0074] In Formula I, Indicates connected or not connected.
[0075] When the When it indicates no connection, the P-type material has the structure shown in Formula I-a:
[0076]
[0077] In formula Ⅰ-a, the ranges of L, R2, R3 and A1 are the same as above.
[0078] The above L is preferably a phenylene group.
[0079] Preferably, the P-type material has a structure shown in Formula Ⅰ-a-2:
[0080]
[0081] In formula Ⅰ-a-2, the ranges of R2, R3 and A1 are the same as above.
[0082] When the When it represents a connected single bond, the P-type material has a structure shown in Formula I-b or Formula I-c:
[0083]
[0084] The range of L1 is LH, that is, a group formed by L connecting a hydrogen atom.
[0085] In some specific embodiments of the present invention, the P-type material has any of the following structures:
[0086]
[0087]
[0088]
[0089]
[0090] The N-type material has a structure shown in Formula II:
[0091]
[0092] Among them, R7, R8, R9, R 10 are independently selected from hydrogen, deuterium, substituted or unsubstituted aryl, heteroaryl or alkyl.
[0093] Preferably, R7, R8, R9, R 10 Independently selected from hydrogen, deuterium, substituted or unsubstituted monocyclic aryl, 2-3 monocyclic aryl fused aryl, monocyclic heteroaryl, 2-3 monocyclic heteroaryl fused heteroaryl, 2-3 monocyclic aryl and monocyclic heteroaryl fused heteroaryl, C1-C10 alkyl.
[0094] The monocyclic aryl group is preferably a phenyl group.
[0095] The heteroatoms of the heteroaryl group include one or more of N, O, and S.
[0096] The monocyclic heteroaryl group is preferably a five-membered or six-membered monocyclic heteroaryl group.
[0097] More preferably, R7, R8, R9, R 10 and independently selected from hydrogen, deuterium, substituted or unsubstituted phenyl, naphthyl, pyridyl, pyrrolyl, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl or tert-butyl.
[0098] In some specific embodiments of the present invention, R7, R8, R9, R 10 are independently selected from hydrogen, deuterium, substituted or unsubstituted phenyl, biphenyl, naphthyl, pyridyl or methyl.
[0099] R7, R8, R9, R 10 The substituents are independently selected from one or more of deuterium, halogen, nitro, cyano and phenyl.
[0100] The L2 is selected from a single bond, a substituted or unsubstituted arylene group or a heteroarylene group.
[0101] Preferably, L2 is selected from a single bond, a substituted or unsubstituted monocyclic arylene group, a condensed arylene group formed by 2 to 3 monocyclic aryl groups, a monocyclic heteroarylene group, a heteroarylene group formed by 2 to 3 monocyclic heteroaryl groups, a heteroarylene group formed by 2 to 3 monocyclic aryl groups and a heteroarylene group formed by 2 to 3 monocyclic heteroaryl groups.
[0102] The heteroatoms of the heteroaryl group include one or more of N, O, and S.
[0103] The heteroaryl group is preferably a five-membered or six-membered heteroaryl group.
[0104] The L2 is preferably a single bond, a substituted or unsubstituted phenylene group, a biphenylene group, a naphthylene group or a pyridylene group.
[0105] The substituent of L2 is preferably one or more of deuterium, halogen, nitro, cyano, and phenyl.
[0106] The R 11 -R 18 Independently, preferably, they are hydrogen, deuterium, substituted or unsubstituted aryl, heteroaryl or alkyl; more preferably, they are hydrogen, deuterium, substituted or unsubstituted monocyclic aryl, fused aryl of 2 to 3 monocyclic aryl groups, monocyclic heteroaryl, heteroaryl of 2 to 3 monocyclic heteroaryl groups, heteroaryl of 2 to 3 monocyclic aryl groups and monocyclic heteroaryl groups, and C1 to C10 alkyl.
[0107] The monocyclic aryl group is preferably a phenyl group.
[0108] The heteroatoms of the heteroaryl group include one or more of N, O, and S.
[0109] The monocyclic heteroaryl group is preferably a five-membered or six-membered monocyclic heteroaryl group.
[0110] Further preferably, the R 11 -R 18 are independently selected from hydrogen, deuterium, substituted or unsubstituted phenyl, naphthyl or methyl.
[0111] The R 11 -R 18 The substituents are preferably independently one or more of deuterium, halogen, nitro, cyano and phenyl.
[0112] In some specific embodiments of the present invention, the N-type material has any of the following structures:
[0113]
[0114]
[0115]
[0116] The present invention also provides an exciplex, comprising a P-type material and an N-type material. The P-type material has a structure shown in Formula III:
[0117]
[0118] Among them, Rx is selected from substituted or unsubstituted aryl or heteroaryl; more preferably, it is a substituted or unsubstituted monocyclic aryl, a fused aryl of 2 to 3 monocyclic aryl groups, a monocyclic heteroaryl, a heteroaryl of 2 to 3 monocyclic heteroaryl groups, a heteroaryl of 2 to 3 monocyclic aryl groups and a heteroaryl of 2 to 3 monocyclic heteroaryl groups.
[0119] The monocyclic aryl group is preferably a phenyl group.
[0120] The heteroatoms of the heteroaryl group include one or more of N, O, and S.
[0121] The monocyclic heteroaryl group is preferably a five-membered or six-membered heteroaryl group.
[0122] More preferably, the Rx is selected from substituted or unsubstituted phenyl or naphthyl.
[0123] The substituent of Rx is selected from one or more of deuterium, halogen, nitro, cyano and phenyl.
[0124] The L3 is selected from a single bond, a substituted or unsubstituted arylene group or a heteroarylene group.
[0125] Preferably, L3 is selected from a single bond, a substituted or unsubstituted monocyclic arylene group, a condensed arylene group formed by 2 to 3 monocyclic aryl groups, a monocyclic heteroarylene group, a heteroarylene group formed by 2 to 3 monocyclic heteroaryl groups, a heteroarylene group formed by 2 to 3 monocyclic aryl groups and a heteroarylene group formed by 2 to 3 monocyclic heteroaryl groups.
[0126] The monocyclic aryl group is preferably a phenyl group.
[0127] The heteroatoms of the heteroaryl group include one or more of N, O, and S.
[0128] The heteroaryl group is preferably a five-membered or six-membered heteroaryl group.
[0129] The L3 is preferably a single bond, a substituted or unsubstituted phenylene group, a naphthylene group or a pyridylene group.
[0130] The substituent of L3 is selected from one or more of deuterium, halogen, nitro, cyano, and phenyl.
[0131] Preferably, A is selected from any of the following structures:
[0132]
[0133] *Indicates the connection location.
[0134] R1 is selected from hydrogen, substituted or unsubstituted aryl, heteroaryl or alkyl.
[0135] Preferably, R1 is selected from hydrogen, substituted or unsubstituted monocyclic aromatic groups, fused aromatic groups of 2 to 3 monocyclic aromatic groups, monocyclic heteroaromatic groups, fused heteroaromatic groups of 2 to 3 monocyclic heteroaromatic groups, fused heteroaromatic groups of 2 to 3 monocyclic aromatic groups and monocyclic heteroaromatic groups, and C1 to C10 alkyl groups.
[0136] The monocyclic aryl group is preferably a phenyl group.
[0137] The heteroatoms of the heteroaryl group include one or more of N, O, and S.
[0138] The monocyclic heteroaryl group is preferably a five-membered or six-membered heteroaryl group.
[0139] More preferably, R1 is selected from hydrogen, substituted or unsubstituted phenyl, naphthyl, anthracenyl, phenanthryl, pyridyl, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl or tert-butyl.
[0140] The substituent group of R1 is selected from one or more of deuterium, halogen, nitro, cyano and phenyl.
[0141] In some specific embodiments of the present invention, the R1 is selected from hydrogen, phenyl, biphenyl, naphthyl or methyl.
[0142] The X is selected from O or S.
[0143] The R4, R5 and R6 are preferably independently hydrogen, substituted or unsubstituted aryl, heteroaryl or alkyl.
[0144] Preferably, R4, R5, and R6 are independently hydrogen, deuterium, substituted or unsubstituted monocyclic aromatic groups, fused aromatic groups of 2 to 3 monocyclic aromatic groups, monocyclic heteroaromatic groups, heteroaromatic groups of 2 to 3 monocyclic heteroaromatic groups, heteroaromatic groups of 2 to 3 monocyclic aromatic groups and monocyclic heteroaromatic groups, or C1 to C10 alkyl groups.
[0145] The substituent groups of R4, R5 and R6 are preferably one or more of deuterium, halogen, nitro, cyano and phenyl.
[0146] More preferably, R4, R5, and R6 are independently hydrogen, deuterium, phenyl, naphthyl, biphenyl, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, or tert-butyl.
[0147] More preferably, R4 and R5 are independently hydrogen, deuterium or methyl.
[0148] More preferably, R6 is hydrogen, deuterium, phenyl, naphthyl, biphenyl or methyl.
[0149] The R 19 -R 26 Independently, preferably, they are hydrogen, deuterium, substituted or unsubstituted aryl, heteroaryl or alkyl; more preferably, they are hydrogen, deuterium, substituted or unsubstituted monocyclic aryl, fused aryl of 2 to 3 monocyclic aryl groups, monocyclic heteroaryl, heteroaryl of 2 to 3 monocyclic heteroaryl groups, heteroaryl of 2 to 3 monocyclic aryl groups and monocyclic heteroaryl groups, and C1 to C10 alkyl.
[0150] The monocyclic aryl group is preferably a phenyl group.
[0151] The heteroatoms of the heteroaryl group include one or more of N, O, and S.
[0152] The monocyclic heteroaryl group is preferably a five-membered or six-membered monocyclic heteroaryl group.
[0153] Further preferably, the R 19 -R 26 Independently, preferably, they are hydrogen, deuterium, substituted or unsubstituted phenyl, naphthyl or methyl.
[0154] The R 19 -R 26 The substituents are preferably independently one or more of deuterium, halogen, nitro, cyano and phenyl.
[0155] In some specific embodiments of the present invention, the P-type material is selected from any of the following structures:
[0156]
[0157]
[0158]
[0159]
[0160] The N-type material has a structure shown in Formula IV:
[0161]
[0162] The R 27 , R 28 , R 29 Independently selected from substituted or unsubstituted aryl, heteroaryl or alkyl; more preferably substituted or unsubstituted monocyclic aryl, fused aryl of 2 to 3 monocyclic aryl groups, monocyclic heteroaryl, fused heteroaryl or C1 to C10 alkyl; the fused heteroaryl includes 2 to 3 monocyclic heteroaryl groups or 2 to 3 monocyclic aryl groups and monocyclic heteroaryl groups.
[0163] The monocyclic aryl group is preferably a phenyl group.
[0164] The heteroatoms of the heteroaryl group include one or more of N, O, and S.
[0165] The monocyclic heteroaryl group is preferably a five-membered or six-membered monocyclic heteroaryl group.
[0166] The C1-C10 alkyl group is preferably a C1-C6 alkyl group, and more preferably a methyl group, an ethyl group, a n-propyl group, an isopropyl group, a n-butyl group, an isobutyl group or a tert-butyl group.
[0167] Further preferably, the R 27 , R 28 , R 29 Independently selected from substituted or unsubstituted phenyl, naphthyl, biphenyl, pyridyl or methyl.
[0168] The R 27 , R 28 , R 29 The substituents are independently selected from one or more of deuterium, halogen, nitro, cyano and phenyl.
[0169] The R 30 It is selected from substituted or unsubstituted aryl or heteroaryl; more preferably, it is a substituted or unsubstituted monocyclic aryl, a fused aryl of 2 to 3 monocyclic aryl groups, a monocyclic heteroaryl, a fused heteroaryl, or a C1 to C10 alkyl group; the fused heteroaryl group includes 2 to 3 monocyclic heteroaryl groups or 2 to 3 monocyclic aryl groups and a monocyclic heteroaryl group.
[0170] The monocyclic aryl group is preferably a phenyl group.
[0171] The heteroatoms of the heteroaryl group include one or more of N, O, and S.
[0172] The monocyclic heteroaryl group is preferably a five-membered or six-membered monocyclic heteroaryl group.
[0173] The C1-C10 alkyl group is preferably a C1-C6 alkyl group, and more preferably a methyl group, an ethyl group, a n-propyl group, an isopropyl group, a n-butyl group, an isobutyl group or a tert-butyl group.
[0174] Further preferably, the R 30 is selected from substituted or unsubstituted phenyl, naphthyl, biphenyl or methyl.
[0175] Preferably, the R 30 The substituent is selected from one or more of deuterium, halogen, nitro, cyano and phenyl.
[0176] The L4 is selected from a single bond, a substituted or unsubstituted aryl or heteroaryl; preferably a single bond, a substituted or unsubstituted monocyclic aryl, a fused aryl of 2 to 3 monocyclic aryl groups, a monocyclic heteroaryl, a fused heteroaryl; the fused heteroaryl includes 2 to 3 monocyclic heteroaryl groups or 2 to 3 monocyclic aryl groups and a monocyclic heteroaryl group.
[0177] The monocyclic aryl group is preferably a phenyl group.
[0178] The heteroatoms of the heteroaryl group include one or more of N, O, and S.
[0179] The monocyclic heteroaryl group is preferably a five-membered or six-membered monocyclic heteroaryl group.
[0180] More preferably, L4 is selected from a single bond, a substituted or unsubstituted phenyl, a naphthyl or a pyridyl.
[0181] Preferably, the substituent of L4 is selected from one or more of deuterium, halogen, nitro, cyano and phenyl.
[0182] The Y is O or S.
[0183] The n is any integer from 1 to 7; specifically, it can be 1, 2, 3, 4, 5, 6 or 7.
[0184] *Indicates the connection location.
[0185] In the present invention, the L4 and the R 30 They can be connected to the same benzene ring or to different benzene rings.
[0186] In some specific embodiments of the present invention, the N-type material is selected from any of the following structures:
[0187]
[0188]
[0189] The present invention provides an organic electroluminescent device, comprising a light-emitting layer, wherein the main material of the light-emitting layer comprises the above-mentioned exciplex.
[0190] The organic electroluminescent device provided by the present invention can be an organic light-emitting device familiar to those skilled in the art. Optionally, the organic electroluminescent device includes a substrate, an anode, a hole transport layer, a light-emitting auxiliary layer, a light-emitting layer, a hole blocking layer, an electron transport layer, and a cathode in sequence.
[0191] The present invention has no special restrictions on the materials and thicknesses of the substrate, anode, hole transport layer, luminescence auxiliary layer, hole blocking layer, electron transport layer, and cathode of the organic electroluminescent device, and they can be conventional materials and thicknesses well known to those skilled in the art.
[0192] Optionally, the material of the anode can be selected from metals such as copper, gold, silver, iron, chromium, nickel, manganese, palladium, platinum, etc. and their alloys; such as metal oxides such as indium oxide, zinc oxide, indium tin oxide (ITO), indium zinc oxide (IZO), etc.; such as conductive polymers such as polyaniline, polypyrrole, poly (3-methylthiophene), etc., or other known materials suitable for anodes. In some embodiments of the present invention, the anode is indium tin oxide (ITO). Optionally, the thickness of the anode is 80-200nm.
[0193] Optionally, the hole transport layer includes a first hole transport layer and a second hole transport layer. Optionally, the thickness of the first hole transport layer is 3-15 nm, and the thickness of the second hole transport layer is 100-180 nm.
[0194] Optionally, the light-emitting auxiliary layer has a thickness of 3-15 nm.
[0195] Optionally, the hole blocking layer has a thickness of 3-10 nm.
[0196] Optionally, the electron transport layer includes a first electron transport layer and a second electron transport layer. Optionally, the thickness of the first electron transport layer is 20-40 nm, and the thickness of the second electron transport layer is 0.5-5 nm.
[0197] Optionally, the cathode material may be selected from metals such as aluminum, magnesium, silver, indium, tin, titanium, etc. and their alloys; such as multilayer metal materials such as LiF / Al, LiO2 / Al, BaF2 / Al, etc.; or other known materials suitable for the cathode. In some embodiments of the present invention, the cathode is a magnesium-silver electrode. Optionally, the cathode has a thickness of 10-18 nm.
[0198] Optionally, a capping layer is provided on the cathode surface.
[0199] Optionally, the capping layer has a thickness of 60-100 nm.
[0200] Optionally, the P-type material and the N-type material are stacked or pre-mixed into a mixed material.
[0201] When the P-type material and the N-type material are stacked, optionally, the light-emitting layer includes a first light-emitting layer and a second light-emitting layer, and the first light-emitting layer and the second light-emitting layer are respectively selected from the P-type material and the N-type material in the above-mentioned exciplex.
[0202] Optionally, when the P-type material and the N-type material are stacked, the P-type material is disposed on a side of the light-emitting layer close to the anode, and the N-type material is disposed on a side of the light-emitting layer close to the cathode.
[0203] Optionally, the thickness of the first light-emitting layer is 5-25 nm, and the thickness of the second light-emitting layer is 5-25 nm.
[0204] When the P-type material and the N-type material are premixed into a mixed material, optionally, any one of the light-emitting layers includes a film layer formed of a mixed material of the P-type material and the N-type material.
[0205] Optionally, the light-emitting layer further includes a doping material.
[0206] Optionally, the doping material is doped into the material containing anthracene groups. Optionally, when the material of the light-emitting layer includes the N-type material shown in Formula II, the light-emitting layer where the N-type material is located also includes a doping material.
[0207] Optionally, the addition ratio of the doping material is 0.5%-5%, preferably 1%-2%.
[0208] Optionally, the difference in absolute value between the HOMO energy level of the doping material and the HOMO energy level of the P-type material is less than 0.3 eV.
[0209] Optionally, the difference in absolute value between the LUMO energy level of the doping material and the LUMO energy level of the N-type material is greater than 0.2 eV.
[0210] Optionally, the doping material is selected from compounds containing pyrene, perylene or boron nitrogen structure, more preferably a compound represented by any of the following structures:
[0211]
[0212]
[0213] Optionally, when the material of the light-emitting layer is selected from the P-type material shown in Formula III, the light-emitting layer where the P-type material is located further includes a doping material.
[0214] Optionally, the addition ratio of the doping material is 0.5%-5%, preferably 1%-2%.
[0215] The doping materials are the same as above and will not be described in detail here.
[0216] Optionally, the light-emitting layer includes a mixed material of the above-mentioned exciplex.
[0217] Optionally, the light-emitting layer further includes a doping material.
[0218] Optionally, the addition ratio of the doping material is 0.5%-5%, preferably 1%-2%.
[0219] The doping materials are the same as above and will not be described in detail here.
[0220] Optionally, in the exciplex, a mass ratio of the P-type material to the N-type material is 1:9 to 9:1.
[0221] In the present invention, when the P-type material and the N-type material are evaporated in two layers, an exciplex is formed at the interface of the P-type and N-type materials, such as in Examples 1-14; when the P-type material and the N-type material are co-evaporated or premixed, an exciplex is formed in the double host material layer, such as in Example 15, and the triplet excitons formed are then transferred to one of the host materials, and TTA occurs on the host material to generate singlet excitons, emitting blue light. Converting a low-energy triplet state into a high-energy singlet state through TTA can reduce the turn-on voltage and driving voltage, and can be well applied in the field of electroluminescent technology.
[0222] Optionally, the organic electroluminescent device is prepared according to the following method:
[0223] An anode is formed on a transparent or opaque smooth substrate, an organic thin layer is formed on the anode, and a cathode is formed on the organic thin layer.
[0224] Optionally, the organic thin layer may be formed by a known film-forming method such as evaporation, sputtering, spin coating, dipping, ion plating, etc.
[0225] In the present invention, the above-mentioned organic electroluminescent device (OLED device) can be used in a display device, wherein the organic light-emitting display device can be a mobile phone display, a computer display, a TV display, a smart watch display, a smart car display panel, a VR or AR helmet display, a display of various smart devices, etc.
[0226] Based on this, the present invention provides a display panel, comprising the above-mentioned organic electroluminescent device.
[0227] Optionally, the organic electroluminescent device is a single-layer organic electroluminescent device or a multi-layer organic electroluminescent device.
[0228] The present invention also provides a display device, comprising the above display panel.
[0229] In order to further illustrate the present invention, the following is a detailed description in conjunction with the embodiments. However, it should be understood that these descriptions are only for further illustrating the features and advantages of the present invention, rather than limiting the claims of the invention.
[0230] All raw materials of the present invention have no particular limitation on their sources, and can be purchased from the market or prepared according to conventional methods known to those skilled in the art.
[0231] Example 1
[0232] An OLED display panel is provided, and its structural schematic diagram is as follows Figure 1 As shown, the OLED display panel includes a sequentially stacked glass substrate 1, an indium tin oxide (ITO) anode 2, a first hole transport layer 3, a second hole transport layer 4, a light-emitting auxiliary layer 5, light-emitting layers 6 and 7, a hole blocking layer 8, a first electron transport layer 9, a second electron transport layer 10, a cathode 11 and a capping layer 12. The thickness of the ITO anode 2 is 15 nm, the thickness of the first hole transport layer 3 is 10 nm, the thickness of the second hole transport layer 4 is 120 nm, the thickness of the light-emitting auxiliary layer 5 is 7 nm, the total thickness of the light-emitting layers 6 and 7 is 18 nm, the thickness of the hole blocking layer 8 is 5 nm, the thickness of the first electron transport layer 9 is 30 nm, the thickness of the second electron transport layer 10 is 1 nm, the thickness of the cathode 11 is 13.5 nm (magnesium-silver electrode, magnesium-silver mass ratio is 1:9), and the thickness of the capping layer (CPL) 12 is 70 nm.
[0233] The preparation steps of OLED display panel are as follows:
[0234] (1) Cut the glass substrate 1 into a size of 50 mm×50 mm×0.7 mm, ultrasonically treat it in isopropyl alcohol and deionized water for 30 min respectively, then repeatedly wash it with distilled water twice, and then expose it to ozone for cleaning for 10 min; install the glass substrate with ITO anode 2 obtained by magnetron sputtering on a vacuum deposition device;
[0235] (2) When the vacuum degree is 2×10 -6 Pa, vacuum co-evaporation of compounds PD and HT on the ITO anode layer 2 as the first hole transport layer 3, wherein the mass ratio of PD to HT is 3:97 and the thickness is 10 nm;
[0236] (3) vacuum evaporating compound HT on the first hole transport layer 3 at an evaporation rate of 1 A / s as the second hole transport layer 4 with a thickness of 120 nm;
[0237] (4) vacuum evaporating compound F as a light-emitting auxiliary layer 5 on the second hole transport layer 4 at an evaporation rate of 1 A / s, with a thickness of 7 nm;
[0238] (5) Compound 1-P1 of the present invention is vacuum-deposited on the light-emitting auxiliary layer 5 as the light-emitting layer 6 with a thickness of 9 nm; Compounds 1-N1 and BD ( BD mentioned in the following examples and comparative examples all have this structure) as the light-emitting layer 7, wherein 1-N1 is used as the main material, BD is used as the doping material, the mass ratio of 1-N1 to BD is 98.5:1.5, and the thickness is 9 nm;
[0239] (6) vacuum evaporating compound HB on the light-emitting layer 7 at a evaporation rate of 0.5 A / s as a hole blocking layer 8 with a thickness of 5 nm;
[0240] (7) vacuum evaporating compounds ET and Alq3 on the hole blocking layer 8 as the first electron transport layer 9, the mass ratio of ET and Alq3 is 50:50, and the thickness is 30 nm;
[0241] (8) vacuum evaporating metal Yb as the second electron transport layer 10 at a evaporation rate of 0.5 A / s on the first electron transport layer 9, with a thickness of 1 nm;
[0242] (7) vacuum evaporating a magnesium-silver electrode on the second electron transport layer 10 as the cathode 11, with a mass ratio of Mg to Ag of 1:9 and a thickness of 13.5 nm;
[0243] (8) A high refractive index compound CPL is vacuum-deposited on the cathode 11 at a deposition rate of 1 A / s to a thickness of 70 nm to serve as the cathode covering layer (cap layer) 12 .
[0244] The structure of the compound used in the OLED device is as follows:
[0245]
[0246] Embodiments 2 to 10
[0247] The organic compounds 1-P1 and 1-N1 in step (5) of Example 1 were replaced by equal amounts of other compounds, respectively. Please refer to Table 1 for specific differences. The other preparation steps were the same as in Example 1.
[0248] Embodiment 11
[0249] Replace step (5) in Example 1 with the following:
[0250] Compounds 2-P2 and BD in the present invention are vacuum evaporated on the light-emitting auxiliary layer 5 to form a light-emitting layer 6, wherein 2-P2 is used as a main material, BD is used as a doping material, the mass ratio of 2-P2 to BD is 98.5:1.5, and the thickness is 9 nm; and compound 2-N1 in this scheme is vacuum evaporated on the light-emitting layer 6 to form a light-emitting layer 7, with a thickness of 9 nm;
[0251] The other preparation steps are the same as in Example 1.
[0252] Examples 12-14
[0253] The preparation method is similar to that of Example 11, except that the compounds 2-P2 and 2-N1 in Example 11 are replaced by equal amounts of other compounds, respectively. Please refer to Table 1 for specific differences.
[0254] Embodiment 15
[0255] The main material in the light-emitting layer 6 in step (5) of Example 1 is replaced with a mixed material of 2-P38 and 2-N19, wherein the mass ratio of 2-P38 and 2-N19 is 6:4, BD is used as a doping material, the mass ratio of the mixed material of 2-P38 and 2-N19 to BD is 98.5:1.5, the thickness is adjusted to 18nm, the light-emitting layer 7 is cancelled, and the other preparation steps are the same as device implementation 1.
[0256] Comparative Example 1
[0257] An OLED display panel, which differs from Example 1 only in that the light-emitting layer 6 in step (5) is eliminated and the main material in the light-emitting layer 7 is replaced by an equal mass of compound BH-1
[0258] The thickness of the light-emitting layer 7 is adjusted to 18 nm; other raw materials and preparation steps are the same.
[0259] Comparative Example 2
[0260] An OLED display panel, which differs from Example 1 only in that the light-emitting layer 6 in step (5) is eliminated and the thickness of the light-emitting layer 7 is adjusted to 18 nm; other raw materials and preparation steps are the same.
[0261] Comparative Example 3
[0262] An OLED display panel, which differs from Example 1 only in that the light-emitting layer 6 in step (5) is eliminated, the main material in the light-emitting layer 7 is replaced with an equal amount of 2-P4 material, and the thickness is adjusted to 18nm; other raw materials and preparation steps are the same.
[0263] Performance evaluation of OLED display panels:
[0264] The current of the OLED devices prepared in Examples 1-15 and Comparative Examples 1-3 at different voltages was tested using a Keithley 2365A digital nanovoltmeter, and the current was then divided by the luminous area to obtain the current density of the OLED devices at different voltages. The brightness and radiant energy flux density of the OLED devices at different voltages were tested using a Konicaminolta CS-2000 spectroradiometer. Based on the current density and brightness of the OLED devices at different voltages, the current density (10 mA / cm 2 )’s operating voltage (Von) and current efficiency BI (Cd / A / CIE y); the lifespan LT95 was obtained by measuring the time when the brightness of the OLED device reached 95% of the initial brightness; the performance of other device structures was compared with the voltage / efficiency / lifespan of the device comparison ratio as 100%, and the data are shown in Table 1.
[0265] Table 1 OLED device performance test results
[0266]
[0267]
[0268] In Table 1, V on / V Ref. Refers to the relative working voltage with the working voltage of comparative example 1 as 100%; BI / BI Ref. Refers to the relative current efficiency with the current efficiency of Comparative Example 1 as 100%; LT95 / LT95 Ref. It refers to the relative lifespan with the lifespan of Comparative Example 1 being 100%.
[0269] The data in Table 1 show that the exciplex provided by the present invention is used as a light-emitting layer of the device, which helps to improve the current efficiency and life of the device.
[0270] The above embodiments are only used to help understand the method and core idea of the present invention. It should be noted that, for those skilled in the art, several improvements and modifications can be made to the present invention without departing from the principles of the present invention, and these improvements and modifications also fall within the scope of protection of the claims of the present invention.
Claims
1. An exciplex, characterized in that: Including P-type materials and N-type materials; The P-type material has a structure shown in Formula I: Wherein, A1 and A2 are independently selected from H or any of the following structures, and A1 and A2 are not H at the same time: R1 is selected from hydrogen, substituted or unsubstituted aryl, heteroaryl or alkyl; X is selected from O or S; R2, R3, R4, R5, and R6 are independently selected from hydrogen, deuterium, substituted or unsubstituted aryl, heteroaryl, or alkyl; L is selected from a single bond, a substituted or unsubstituted arylene or heteroarylene; The N-type material has a structure shown in Formula II: Among them, R7, R8, R9, R 10 are independently selected from hydrogen, deuterium, substituted or unsubstituted aryl, heteroaryl or alkyl; L2 is selected from a single bond, a substituted or unsubstituted arylene or heteroarylene; R 11 -R 18 are independently selected from hydrogen, deuterium, substituted or unsubstituted aryl, heteroaryl or alkyl; Or the P-type material has a structure shown in Formula III: wherein Rx is selected from substituted or unsubstituted aryl or heteroaryl; L3 is selected from a single bond, a substituted or unsubstituted arylene or heteroarylene; A is selected from any of the following structures: R1 is selected from hydrogen, substituted or unsubstituted aryl, heteroaryl or alkyl; X is selected from O or S; R4, R5, R6 are independently selected from hydrogen, substituted or unsubstituted aryl, heteroaryl or alkyl; R 19 -R 26 Independently selected from hydrogen, deuterium, substituted or unsubstituted aryl, heteroaryl or alkyl; the N-type material has a structure shown in Formula IV: R 27 , R 28 , R 29 R is independently selected from substituted or unsubstituted aryl, heteroaryl or alkyl; 30 is selected from substituted or unsubstituted aryl, heteroaryl or alkyl; L4 is selected from a single bond, a substituted or unsubstituted aryl or heteroaryl group; Y is O or S; n is any integer from 1 to 7; * indicates the connection location; Indicates the connection location.
2. The exciplex according to claim 1, characterized in that The R1 is selected from hydrogen, substituted or unsubstituted monocyclic aromatic groups, fused aromatic groups of 2 to 3 monocyclic aromatic groups, monocyclic heteroaromatic groups, fused heteroaromatic groups or C1 to C10 alkyl groups; the fused heteroaromatic groups include 2 to 3 monocyclic heteroaromatic groups or 2 to 3 monocyclic aromatic groups and monocyclic heteroaromatic groups; The substituent group of R1 is selected from one or more of deuterium, halogen, nitro, cyano, and phenyl; The R2, R3, R4, R5, and R6 are independently selected from hydrogen, deuterium, substituted or unsubstituted monocyclic aromatic groups, fused aromatic groups of 2 to 3 monocyclic aromatic groups, monocyclic heteroaromatic groups, fused heteroaromatic groups, or C1 to C10 alkyl groups; the fused heteroaromatic groups include 2 to 3 monocyclic heteroaromatic groups or 2 to 3 monocyclic aromatic groups and monocyclic heteroaromatic groups; The L is selected from a single bond, a substituted or unsubstituted monocyclic arylene group, a condensed arylene group of 2 to 3 monocyclic aryl groups, a monocyclic heteroarylene group, and a condensed heteroarylene group; the condensed heteroarylene group includes 2 to 3 monocyclic heteroaryl groups or 2 to 3 monocyclic aryl groups and a monocyclic heteroaryl group; The substituent groups of R2, R3, R4, R5, R6 and L are independently selected from one or more of deuterium, halogen, nitro, cyano and phenyl; R7, R8, R9, R 10 Independently selected from hydrogen, deuterium, substituted or unsubstituted monocyclic aromatic groups, fused aromatic groups of 2 to 3 monocyclic aromatic groups, monocyclic heteroaromatic groups, fused heteroaromatic groups or C1 to C10 alkyl groups; the fused heteroaromatic groups include 2 to 3 monocyclic heteroaromatic groups or 2 to 3 monocyclic aromatic groups and monocyclic heteroaromatic groups; R7, R8, R9, R 10 The substituents are independently selected from one or more of deuterium, halogen, nitro, cyano, and phenyl; The L2 is selected from a single bond, a substituted or unsubstituted monocyclic arylene group, a condensed arylene group of 2 to 3 monocyclic aryl groups, a monocyclic heteroarylene group, and a condensed heteroarylene group; the condensed heteroarylene group includes 2 to 3 monocyclic heteroaryl groups or 2 to 3 monocyclic aryl groups and a monocyclic heteroaryl group; The substituent of L2 is preferably one or more of deuterium, halogen, nitro, cyano, and phenyl; The R 11 -R 18 Independently selected from hydrogen, deuterium, substituted or unsubstituted monocyclic aromatic groups, fused aromatic groups of 2 to 3 monocyclic aromatic groups, monocyclic heteroaromatic groups, fused heteroaromatic groups or C1 to C10 alkyl groups; the fused heteroaromatic groups include 2 to 3 monocyclic heteroaromatic groups or 2 to 3 monocyclic aromatic groups and monocyclic heteroaromatic groups; The R 11 -R 18 The substituents are independently selected from one or more of deuterium, halogen, nitro, cyano, and phenyl; The heteroatoms of the heteroaryl group include one or more of N, O, and S.
3. The exciplex according to claim 2, characterized in that The R1 is selected from hydrogen, substituted or unsubstituted phenyl, naphthyl, anthracenyl, phenanthrenyl, pyridyl, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl or tert-butyl; Said R2 and R3 are independently selected from hydrogen, deuterium, phenyl, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl or tert-butyl; The R4, R5, and R6 are independently selected from hydrogen, deuterium, phenyl, naphthyl, biphenyl, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, or tert-butyl; The L is selected from a single bond, a substituted or unsubstituted phenylene, a naphthylene or a pyridylene; R7, R8, R9, R 10 independently selected from hydrogen, deuterium, substituted or unsubstituted phenyl, naphthyl, pyridyl, pyrrolyl, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl or tert-butyl; The L2 is selected from a single bond, a substituted or unsubstituted phenylene, a biphenylene, a naphthylene or a pyridylene; The R 11 -R 18 are independently selected from hydrogen, deuterium, substituted or unsubstituted phenyl, naphthyl or methyl.
4. The exciplex according to claim 3, characterized in that The P-type material has any of the following structures: The N-type material has any of the following structures:
5. The exciplex according to claim 1, characterized in that The Rx is selected from substituted or unsubstituted monocyclic aromatic groups, fused aromatic groups of 2 to 3 monocyclic aromatic groups, monocyclic heteroaromatic groups, and fused heteroaromatic groups; the fused heteroaromatic groups include 2 to 3 monocyclic heteroaromatic groups or 2 to 3 monocyclic aromatic groups and monocyclic heteroaromatic groups; The substituent of Rx is selected from one or more of deuterium, halogen, nitro, cyano, and phenyl; The L3 is selected from a single bond, a substituted or unsubstituted monocyclic arylene group, a condensed arylene group of 2 to 3 monocyclic aryl groups, a monocyclic heteroarylene group, and a condensed heteroarylene group; the condensed heteroarylene group includes 2 to 3 monocyclic heteroaryl groups or 2 to 3 monocyclic aryl groups and a monocyclic heteroaryl group; The substituent of L3 is selected from one or more of deuterium, halogen, nitro, cyano, and phenyl; The R1 is selected from hydrogen, substituted or unsubstituted monocyclic aromatic groups, fused aromatic groups of 2 to 3 monocyclic aromatic groups, monocyclic heteroaromatic groups, fused heteroaromatic groups or C1 to C10 alkyl groups; the fused heteroaromatic groups include 2 to 3 monocyclic heteroaromatic groups or 2 to 3 monocyclic aromatic groups and monocyclic heteroaromatic groups; The substituent group of R1 is selected from one or more of deuterium, halogen, nitro, cyano, and phenyl; The R4, R5, and R6 are independently selected from hydrogen, deuterium, substituted or unsubstituted monocyclic aromatic groups, fused aromatic groups of 2 to 3 monocyclic aromatic groups, monocyclic heteroaromatic groups, fused heteroaromatic groups, or C1 to C10 alkyl groups; the fused heteroaromatic groups include 2 to 3 monocyclic heteroaromatic groups or 2 to 3 monocyclic aromatic groups and monocyclic heteroaromatic groups; The substituent groups of R4, R5 and R6 are selected from one or more of deuterium, halogen, nitro, cyano and phenyl; The R 19 -R 26 Independently selected from hydrogen, deuterium, substituted or unsubstituted monocyclic aromatic groups, fused aromatic groups of 2 to 3 monocyclic aromatic groups, monocyclic heteroaromatic groups, fused heteroaromatic groups or C1 to C10 alkyl groups; the fused heteroaromatic groups include 2 to 3 monocyclic heteroaromatic groups or 2 to 3 monocyclic aromatic groups and monocyclic heteroaromatic groups; The R 19 -R 26 The substituents are independently selected from one or more of deuterium, halogen, nitro, cyano, and phenyl; The heteroatoms of the heteroaryl group include one or more of N, O, and S; The R 27 , R 28 , R 29 Independently selected from substituted or unsubstituted monocyclic aromatic groups, fused aromatic groups of 2 to 3 monocyclic aromatic groups, monocyclic heteroaromatic groups, fused heteroaromatic groups or C1 to C10 alkyl groups; the fused heteroaromatic groups include 2 to 3 monocyclic heteroaromatic groups or 2 to 3 monocyclic aromatic groups and monocyclic heteroaromatic groups; The R 27 , R 28 , R 29 The substituents are independently selected from one or more of deuterium, halogen, nitro, cyano, and phenyl; The R 30 is selected from substituted or unsubstituted monocyclic aromatic groups, fused aromatic groups of 2 to 3 monocyclic aromatic groups, monocyclic heteroaromatic groups, fused heteroaromatic groups or C1 to C10 alkyl groups; the fused heteroaromatic groups include 2 to 3 monocyclic heteroaromatic groups or 2 to 3 monocyclic aromatic groups and monocyclic heteroaromatic groups; The R 30 The substituent is selected from one or more of deuterium, halogen, nitro, cyano, and phenyl; The L4 is selected from a single bond, a substituted or unsubstituted monocyclic aromatic group, a fused aromatic group of 2 to 3 monocyclic aromatic groups, a monocyclic heteroaromatic group, and a fused heteroaromatic group; the fused heteroaromatic group includes 2 to 3 monocyclic heteroaromatic groups or 2 to 3 monocyclic aromatic groups and a monocyclic heteroaromatic group; The substituent of L4 is selected from one or more of deuterium, halogen, nitro, cyano, and phenyl.
6. The exciplex according to claim 5, characterized in that The Rx is selected from substituted or unsubstituted phenyl or naphthyl; The L3 is selected from a single bond, a substituted or unsubstituted phenylene, a naphthylene or a pyridylene; The R1 is selected from hydrogen, substituted or unsubstituted phenyl, naphthyl, anthracenyl, phenanthrenyl, pyridyl, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl or tert-butyl; The R4, R5, and R6 are independently selected from hydrogen, deuterium, phenyl, naphthyl, biphenyl, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, or tert-butyl; The R 19 -R 26 independently selected from hydrogen, deuterium, substituted or unsubstituted phenyl, naphthyl or methyl; The R 27 , R 28 , R 29 independently selected from substituted or unsubstituted phenyl, naphthyl, biphenyl, pyridyl or methyl; The R 30 is selected from substituted or unsubstituted phenyl, naphthyl, biphenyl or methyl; The L4 is selected from a single bond, a substituted or unsubstituted phenyl group, a naphthyl group or a pyridyl group.
7. The exciplex according to claim 6, characterized in that The P-type material is selected from any of the following structures: The N-type material is selected from any of the following structures:
8. An organic electroluminescent device, characterized in that: It comprises a light-emitting layer, wherein the host material of the light-emitting layer comprises the exciplex according to any one of claims 1 to 7.
9. The organic electroluminescent device according to claim 8, characterized in that: In the exciplex, the mass ratio of the P-type material to the N-type material is 1:9 to 9:
1.
10. The organic electroluminescent device according to claim 8, characterized in that: The P-type material and the N-type material are stacked or pre-mixed into a mixed material.
11. The organic electroluminescent device according to any one of claims 8 to 10, characterized in that: The light-emitting layer further comprises a doping material; The difference between the absolute value of the HOMO energy level of the doping material and the HOMO energy level of the P-type material is less than 0.3 eV; The difference in absolute value between the LUMO energy level of the doping material and the LUMO energy level of the N-type material is greater than 0.2 eV.
12. A display panel comprising the organic electroluminescent device according to any one of claims 8 to 11; The organic electroluminescent device is a single-layer organic electroluminescent device or a multi-layer organic electroluminescent device.