Compounds, capping layer material and organic light-emitting device

Abstract

Disclosed are compounds, a capping layer material, and an organic light-emitting device. The capping layer material comprises compounds represented by formula I and / or formula II. By introducing a cyclic imide structure, the compounds can reduce the refractive indexes of capping layers, and also significantly enhance the peeling adhesion between the capping layers and cathodes, thereby fundamentally solving the problem of insufficient interfacial bonding force caused by the presence of fluorine atoms in existing fluorine-containing materials. In addition, ultraviolet absorption of said compounds will exhibit a blue shift, which can ensure that light emitted from devices is not absorbed by capping layers, thereby improving the light emission efficiency of devices.

Description

Compound, cover layer material and organic light-emitting device TECHNICAL FIELD

[0001] The present application relates to the technical field of organic light-emitting materials, in particular to a compound, a cover layer material and an organic light-emitting device. BACKGROUND

[0002] Organic light-emitting devices have been widely used in various main display screens and the like, and their practicality has made great progress. Although the research on organic electroluminescence has progressed very rapidly, there are still many problems to be solved, such as the need to improve the external quantum efficiency (EQE). For an organic light-emitting device, the luminescence quantum efficiency of the device is a comprehensive reflection of various factors and is also an important indicator for measuring the quality of the device.

[0003] At present, some high-performance organic light-emitting materials have been commercialized, among which the use of specific structure amine derivatives with high refractive index or the use of materials meeting specific parameter requirements as a cover layer can improve the light extraction efficiency and color purity to a certain extent. However, the existing solutions have not solved the problem of difficult trade-off between luminous efficiency and color purity, especially in the preparation of blue light-emitting elements, where this contradiction is more prominent.

[0004] In view of this, some researchers have proposed the use of a stacked cover layer structure of a high refractive layer and a low refractive layer to improve the light extraction efficiency and color purity. However, the existing technology generally reduces the refractive index of the material by introducing fluorine atoms, which has obvious drawbacks in practical application. For example, the introduction of fluorine atoms will weaken the interfacial adhesion between the material and the cathode (such as Ag electrode), which is prone to cause interlayer peeling, thereby affecting the structural stability and service life of the device. SUMMARY

[0005] The present application aims to reduce the refractive index of the cover layer while improving the peeling adhesion between the cover layer and the cathode.

[0006] To achieve the above-mentioned purpose, the first aspect of the present application provides a cover layer material comprising a compound represented by Formula I and / or Formula II:

[0007] In Formula I:

[0008] A1 and A2 are the same or different, and independently a five-membered ring or a six-membered ring;

[0009] when A1and A2are both five-membered rings, A is selected from the group consisting of a substituted or unsubstituted C6-C30 aryl group, a substituted or unsubstituted C3-C30 heteroaryl group, a substituted or unsubstituted C6-C24 aryl group derivative, a substituted or unsubstituted C3-C24 heteroaryl group derivative, a cyclobutyl group; Ak1and Ak2are the same or different and are independently selected from the group consisting of a substituted or unsubstituted C1-C30 alkyl, a substituted or unsubstituted C1-C30 heteroalkyl, a substituted or unsubstituted C3-C30 cycloalkyl, a substituted or unsubstituted C2-C30 heterocycloalkyl, a substituted or unsubstituted C1-C30 alkylamine, a substituted or unsubstituted C1-C30 heteroalkylamine, a substituted or unsubstituted C3-C30 cycloalkylamine, a substituted or unsubstituted C2-C30 heterocycloalkylamine, a substituted or unsubstituted C3-C30 cycloalkylcarbonyl, or are bonded to adjacent atoms to form a ring;

[0010] when A1and A2are different or both six-membered rings, A is selected from the group consisting of a substituted or unsubstituted C6-C30 aryl group, a substituted or unsubstituted C3-C30 heteroaryl group; Ak1and Ak2are the same or different and are independently selected from the group consisting of a substituted or unsubstituted C1-C30 alkyl, a substituted or unsubstituted C1-C30 heteroalkyl, a substituted or unsubstituted C3-C30 cycloalkyl, a substituted or unsubstituted C2-C30 heterocycloalkyl, a substituted or unsubstituted C1-C30 alkylamine, a substituted or unsubstituted C1-C30 heteroalkylamine, a substituted or unsubstituted C3-C30 cycloalkylamine, a substituted or unsubstituted C2-C30 heterocycloalkylamine, or are bonded to adjacent atoms to form a ring;

[0011] in formula II:

[0012] A1and A2are the same or different and are independently a five-membered ring or a six-membered ring;

[0013] when A1and A2are both five-membered rings, A is selected from the group consisting of a substituted or unsubstituted C6-C30 aryl group, a substituted or unsubstituted C3-C30 heteroaryl group, a cyclobutyl group; Ar1and Ar2are the same or different and are independently selected from the group consisting of a substituted or unsubstituted C6-C24 aryl, a substituted or unsubstituted C3-C24 heteroaryl;

[0014] when A1and A2are different or both six-membered rings, A is selected from the group consisting of a substituted or unsubstituted C6-C30 aryl group, a substituted or unsubstituted C3-C30 heteroaryl group; Ar1and Ar2are the same or different and are independently selected from the group consisting of a substituted or unsubstituted C6-C24 aryl, a substituted or unsubstituted C3-C24 heteroaryl;

[0015] In Formula I and Formula II, R is selected from hydrogen, or one or more substituents selected from deuterium, fluorine, chlorine, bromine, cyano, isonitrile, fluorine-containing group, nitro, substituted or unsubstituted C1-C30 alkyl, substituted or unsubstituted C3-C30 cycloalkyl, substituted or unsubstituted C1-C30 heteroalkyl, substituted or unsubstituted C2-C30 heterocycloalkyl, substituted or unsubstituted C1-C30 alkylthio, substituted or unsubstituted C6-C30 aryl, substituted or unsubstituted C2-C30 heteroaryl, substituted or unsubstituted C1-C30 ketone, substituted or unsubstituted C2-C30 alkoxycarbonyl, substituted or unsubstituted C6-C30 aryloxycarbonyl, silyl, arylsilyl, ester phosphine oxide, sulfone, nitrogen heteroaryl, carboxyl, ether group;

[0016] Any hydrogen atom on Formula I and / or Formula II is optionally substituted with deuterium.

[0017] A second aspect of the present application provides a compound, which is a compound as shown in the aforementioned Formula I and / or Formula II.

[0018] A third aspect of the present application provides an organic light-emitting device, comprising a first electrode, an organic layer, a second electrode and a capping layer structure stacked in sequence, and the capping layer structure comprises a capping layer material as described in the first aspect or a compound as described in the second aspect.

[0019] In some embodiments, the capping layer structure comprises a low refractive index capping layer, and the low refractive index capping layer is formed by a compound as shown in Formula I and / or Formula II:

[0020] In Formula I and Formula II, A is selected from substituted or unsubstituted C6-C30 aryl, substituted or unsubstituted C3-C30 heteroaryl;

[0021] R is selected from hydrogen, deuterium, substituted or unsubstituted C1-C30 alkyl, substituted or unsubstituted C3-C30 cycloalkyl, substituted or unsubstituted C1-C30 heteroalkyl, substituted or unsubstituted C1-C30 heterocycloalkyl, substituted or unsubstituted C1-C10 fluorinated alkyl, substituted or unsubstituted C1-C10 fluorinated cycloalkyl, substituted or unsubstituted C6-C30 aryl, substituted or unsubstituted C3-C30 heteroaryl;

[0022] A1 and A2 are the same or different, and are independently selected from a five-membered ring or a six-membered ring;

[0023] Ak1and Ak2are the same or different and are independently selected from the group consisting of substituted or unsubstituted C1-C30alkyl, substituted or unsubstituted C1-C30heteroalkyl, substituted or unsubstituted C3-C30cycloalkyl, substituted or unsubstituted C2-C30heterocycloalkyl, substituted or unsubstituted C3-C30cycloalkylcarbonyl, substituted or unsubstituted C1-C30alkylamino, substituted or unsubstituted C1-C30heteroalkylamino, substituted or unsubstituted C3-C30cycloalkylamino, substituted or unsubstituted C2-C30heterocycloalkylamino, or bonded to adjacent atoms to form a ring;

[0024] Ar1and Ar2are the same or different and are independently selected from the group consisting of substituted or unsubstituted C6-C24aryl, substituted or unsubstituted C3-C24heteroaryl.

[0025] In some embodiments, the low refractive index capping layer comprises a compound according to Formula I-1 and / or Formula II-1:

[0026] In Formula I-1, Ak1and Ak2are the same or different and are independently selected from the group consisting of substituted or unsubstituted C1-C30alkyl, substituted or unsubstituted C1-C30heteroalkyl, substituted or unsubstituted C3-C30cycloalkyl, substituted or unsubstituted C2-C30heterocycloalkyl, substituted or unsubstituted C3-C30cycloalkylcarbonyl, substituted or unsubstituted C1-C30alkylamino, substituted or unsubstituted C1-C30heteroalkylamino, substituted or unsubstituted C3-C30cycloalkylamino, substituted or unsubstituted C2-C30heterocycloalkylamino, or bonded to adjacent atoms to form a ring;

[0027] In Formula II-1, Ar1and Ar2are the same or different and are independently selected from the group consisting of substituted or unsubstituted C6-C24aryl, substituted or unsubstituted C3-C24heteroaryl.

[0028] Any hydrogen on Formula I-1 and / or Formula II-1 can optionally be substituted with deuterium.

[0029] In some embodiments, the low refractive index capping layer comprises a compound according to the following formula:

[0030] wherein:

[0031] A is selected from the group consisting of a substituted or unsubstituted C6-C24aryl group or a derivative thereof, a substituted or unsubstituted C3-C24heteroaryl group or a derivative thereof;

[0032] Ak1and Ak2are the same or different, and are independently selected from the group consisting of substituted or unsubstituted C1-C30 chain alkyl, substituted or unsubstituted C1-C30 oxygen chain alkyl, substituted or unsubstituted C1-C30 sulfur chain alkyl, substituted or unsubstituted C1-C30 nitrogen chain alkyl, substituted or unsubstituted C1-C30 phosphorus oxygen chain alkyl, substituted or unsubstituted C1-C30 sulfur sulfone chain alkyl, substituted or unsubstituted C1-C30 sulfoxide chain alkyl;

[0033] R is selected from the group consisting of hydrogen, deuterium, fluorine, fluorine-containing group, substituted or unsubstituted C1-C30 chain alkyl, substituted or unsubstituted C3-C30 cycloalkyl, substituted or unsubstituted C1-C30 hetero chain alkyl, substituted or unsubstituted C2-C30 heterocycloalkyl, substituted or unsubstituted C6-C30 aryl, substituted or unsubstituted C3-C30 heteroaryl;

[0034] Any hydrogen atom in the above formula is optionally substituted with deuterium.

[0035] Compared with the existing fluorine-containing material, the compound of formula I and formula II of the present application can not only reduce the refractive index of the cover layer, but also significantly enhance the peeling adhesion between the cover layer and the cathode by introducing a cyclic imide structure, thereby fundamentally solving the problem of insufficient interface bonding force caused by the presence of fluorine atoms in the existing fluorine-containing material. At the same time, the ultraviolet absorption of the compound is blue-shifted, which can ensure that the light emitted by the device is not absorbed by the cover layer, thereby improving the light emission efficiency of the device. BRIEF DESCRIPTION OF DRAWINGS

[0036] The following drawings detail the exemplary embodiments disclosed in the present application. The same reference numerals in the several views of the drawings represent similar structures. Those skilled in the art will understand that these embodiments are non-limiting, exemplary embodiments, and the drawings are for illustrative and descriptive purposes only and are not intended to limit the scope of the present application, and other embodiments can also achieve the same intent of the invention in the present application. It should be understood that the drawings are not drawn to scale. Among them:

[0037] FIG. 1 is a schematic diagram of the structure of an organic light-emitting device prepared in Example 63, Example 87 and Example 115 of the present application. DETAILED DESCRIPTION

[0038] The following description provides specific application scenarios and requirements of the present application, in order to enable those skilled in the art to manufacture and use the content of the present application. Various local modifications of the disclosed embodiments are obvious to those skilled in the art, and the general principles defined herein can be applied to other embodiments and applications without departing from the spirit and scope of the present application. Therefore, the present application is not limited to the embodiments shown, but is consistent with the widest scope of the claims.

[0039] In view of the urgent need to improve the peeling adhesion between the cover layer and the cathode, the present inventors have found, through extensive research, that the introduction of heteroatoms (O, N) into the molecules of the cover layer material and the construction of a cyclic imide structure can maintain strong interlocking force between the cover layer and the cathode, effectively inhibit interlayer peeling, and at the same time, the material also has a high glass transition temperature (Tg). The reason is that, on the one hand, the lone pair of electrons of the heteroatom can form a weak interaction with the cathode, thereby improving the interfacial peeling adhesion; on the other hand, the planar rigid structure of the cyclic imide is conducive to the close packing of molecules, enhancing the intermolecular forces, not only giving the material a high glass transition temperature, but also further inhibiting interlayer peeling by strengthening the structural stability.

[0040] Unless otherwise specified, "substituted or unsubstituted" in the present text means substituted with one or two or more substituents, or unsubstituted; the substituents when substituted include but are not limited to deuterium, halogen (fluorine, chlorine, bromine, iodine, etc.), nitroso, nitro, acyl, carbonyl, carboxyl, ester, cyano, isocyano, thiocyan, cyanooxy, sulfinyl, sulfonyl, phosphinyl, fluorine-containing group, hydroxyl, amino, phosphinyl, alkoxy, aryloxy, sulfone group, sulfoxide group, alkyl, cycloalkyl, heterocycloalkyl, alkylthio, arylthio, alkylsulfonyl, arylsulfonyl, silyl, boron, aryl, heteroaryl, aralkyl, aralkenyl, alkylaryl, alkylamine group, aralkylamine group, heteroarylamine group, arylamine group, aryl phosphine group, carboxyl derivative group, etc., or substituted with two or more substituents of the above examples. For example, biphenyl can be used as aryl, and can also be regarded as a substituent formed by connecting two phenyl groups.

[0041] When substituted with two or more substituents, each substituent can be the same or different, and adjacent substituents can be bonded to form a ring; the "adjacent substituents" include the substituents on the atoms directly connected to the atom substituted with the relevant substituent, the substituents closest to the relevant substituent in the spatial structure, or other substituents substituted on the atom substituted with the relevant substituent, for example, two substituents substituted at the ortho position on a benzene ring and two substituents substituted on the same carbon on an aliphatic ring can be interpreted as "adjacent substituents"; the ring formed by the bonding of adjacent substituents to each other can be a substituted or unsubstituted aliphatic hydrocarbon ring, a substituted or unsubstituted aromatic hydrocarbon ring, a substituted or unsubstituted aliphatic heterocyclic ring, or a substituted or unsubstituted aromatic heterocyclic ring, wherein the aliphatic hydrocarbon ring refers to a non-aromatic cyclic compound composed of carbon atoms and hydrogen atoms, the aromatic hydrocarbon ring refers to a conjugated cyclic compound composed of carbon atoms and hydrogen atoms and having aromaticity, the aliphatic heterocyclic ring refers to a non-aromatic cyclic compound containing heteroatoms (such as oxygen, nitrogen, sulfur, silicon, etc.) in addition to carbon atoms and hydrogen atoms in the ring, and the aromatic heterocyclic ring refers to an aromatic cyclic compound containing heteroatoms (such as oxygen, nitrogen, sulfur, silicon, etc.) in the ring.

[0042] Generally, "aryl group" refers to the group remaining after removing one or more hydrogen atoms from an aromatic hydrocarbon molecule. In Formula I and Formula II herein, A is fused to the five-membered ring or six-membered ring on both sides, and when A is selected from "aryl group", it specifically refers to the group remaining after removing four hydrogen atoms from an aromatic hydrocarbon molecule; "derivative of aryl group" is a group derived from aryl group by substitution, functional group modification, etc.; "aryl" herein specifically refers to the group remaining after removing one hydrogen atom from an aromatic hydrocarbon molecule. Similarly, "heteroaryl group" herein specifically refers to the group remaining after removing four hydrogen atoms from a heteroaromatic hydrocarbon molecule; "derivative of heteroaryl group" is a group derived from heteroaryl group by substitution, functional group modification, etc.; "heteroaryl" specifically refers to the group remaining after removing one hydrogen atom from a heteroaromatic hydrocarbon molecule. "Cyclobutyl group" herein specifically refers to the group remaining after removing four hydrogen atoms from a cyclobutane molecule.

[0043] Unless otherwise specified, "aryl" herein can be a monocyclic aryl or a polycyclic aryl; the monocyclic aryl includes but is not limited to phenyl, tolyl, nitrophenyl, etc.; the polycyclic aryl includes fused ring aryl, biphenyl type aryl, polycyclic aliphatic hydrocarbon group, wherein the fused ring aryl includes but is not limited to naphthyl, anthryl, phenanthryl, pyrenyl, perylenyl, fluorenyl, etc., wherein the fluorenyl can be substituted (such as 9,9'-dimethylfluorenyl, 9,9'-dibenzofluorenyl, etc.) and two substituents can be combined to form a spiro structure (such as 9,9'-spirobifluorenyl), the biphenyl type aryl includes but is not limited to biphenyl, terphenyl, quaterphenyl, quinquephenyl, etc.; the polycyclic aliphatic hydrocarbon group is a structure formed by the connection of multiple aromatic rings through alkyl, for example, diphenylmethyl ( The "*" appearing in the structural formulae shown herein indicates the point of attachment). The above description of "aryl" applies to the aryl groups in aryloxy, arylthio, arylsulfonyl, arylphosphine, aralkyl, aralkylamino, aralkenyl, alkylaryl, arylamino, and arylheteroarylamino groups.

[0044] Unless otherwise specified, "heteroaryl" as used herein refers to an aryl group containing at least one heteroatom of B, N, O, P, S, Si, and Se, and includes, but is not limited to, pyridyl, pyrrolyl, pyrimidinyl, pyridazinyl, furanyl, thienyl, imidazolyl, pyrazolyl, oxazolyl, isoxazolyl, thiazolyl, isothiazolyl, triazolyl, diazolyl, thiadiazolyl, dithiazolyl, tetrazolyl, pyrazinyl, thiazinyl, triazinyl, tetrazinyl, quinolinyl, isoquinolinyl, quinolinyl, quinazolinyl, quinoxalinyl, naphthyridinyl, acridinyl, phenanthridinyl, phenanthrolinyl, indolizinyl, indolyl, indazolyl, phthalazinyl, pyridopyrimidinyl, pyridopyrazinyl, pyrazinopyrazinyl, benzothiazolyl, benzoxazolyl, benzimidazolyl, benzothienyl, benzofuranyl, dibenzothienyl, dibenzofuranyl, carbazolyl, benzocarbazolyl, dibenzocarbazolyl, indolocarbazolyl, indolophenolocarbazolyl, phenoxazinyl, imidazopyridinyl, phenothiazinyl, imidazophenanthridinyl, benzimidazoquinazolinyl, benzimidazophenanthrolinyl, spiro[fluorene-9,9'-xanthene], dinaphthofuranyl, naphthobenzofuranyl, dinaphthothienyl, naphthobenzothienyl, and the like. The above description of "heteroaryl" applies to the heteroaryl groups in heteroarylamino and arylheteroarylamino groups.

[0045] Unless otherwise specified, "fluorine-containing group" as used herein refers to a chemical group containing a fluorine atom in its structure, which is characterized by the covalent bonding of a fluorine atom to other atoms (e.g., carbon, oxygen, sulfur, nitrogen, silicon, phosphorus, boron, etc.) and includes, but is not limited to, fluoroalkyl groups (e.g., trifluoromethyl (-CF3), perfluorooctyl (-C8F 17 ) and the like), fluoroalkenyl groups, fluoroaryl groups (e.g., p-fluorophenyl (-C6H4F) and the like), fluorine-containing heterocyclic groups (e.g., 2-fluoropyridyl and the like), fluorine-containing oxy groups (e.g., trifluoromethoxy (-OCF3) and the like), fluorine-containing amino groups (e.g., N-fluoroamino (-NF2) and the like), fluorine-containing silicon groups (e.g., trifluoropropylsilyl (-Si(CH2)3CF3) and the like), sulfur-containing fluorine groups, and the like. The fluorine-containing groups can be partially fluorinated or perfluorinated.

[0046] Unless otherwise specified, the alkyl group in the fluoroalkyl group includes, but is not limited to, C1-C20 alkyl group. The cycloalkyl group in the fluorocycloalkyl group includes, but is not limited to, C3-C20 cycloalkyl group. The aryl group in the fluoroaryl group includes, but is not limited to, C6-C24 aryl group. The fluorine-containing oxy group includes, but is not limited to, O-fluoroaryl, O-fluoroalkyl (or fluoroalkoxy), O-fluorocycloalkyl. The alkyl group in the O-fluoroalkyl group includes, but is not limited to, C1-C20 alkyl group. The cycloalkyl group in the O-fluorocycloalkyl group includes, but is not limited to, C3-C20 cycloalkyl group. The fluorine-containing amino group includes, but is not limited to, N-fluoroaryl, N-fluoroalkyl, N-fluorocycloalkyl. The fluorine-containing silicon group includes, but is not limited to, Si-fluoroaryl, Si-fluoroalkyl, Si-fluorocycloalkyl. The sulfur-fluorine-containing group is a group containing both sulfur (S) and fluorine (F) elements, including, but not limited to, sulfur pentafluoride group (-SF), fluorosulfanyl group (-SF), S-fluoroalkyl group, and the alkyl group in the S-fluoroalkyl group includes, but is not limited to, C1-C20 alkyl group.

[0047] Unless otherwise specified, "alkyl" herein can be straight-chain or branched-chain structure, including, but not limited to, methyl, ethyl, propyl (n-propyl, isopropyl), butyl (n-butyl, isobutyl, tert-butyl, sec-butyl, 1-methylbutyl, 1-ethylbutyl), pentyl (n-pentyl, isopentyl, neopentyl, tert-pentyl), hexyl (n-hexyl, 1-methylpentyl, 2-methylpentyl, 4-methyl-2-pentyl, 3,3-dimethylbutyl, 1-ethylbutyl, 2-ethylbutyl), heptyl (n-heptyl, 1-methylhexyl, tert-butylethane), octyl (n-octyl, tert-octyl, 1-methylheptyl, 2-ethylhexyl, 2-propylpentyl), nonyl (n-nonyl, 2,2-dimethylheptyl, 1-ethylpropyl, 1,1-dimethylpropyl), isohexyl, 4-methylhexyl, 5-methylhexyl, and the like.

[0048] In this document, when referring to an alkyl group without specifying whether it is straight-chain or branched-chain, the expression by default encompasses all isomeric forms of the alkyl group, including straight-chain and branched-chain structures. For example, "dodecyl" includes n-dodecyl (straight-chain) as well as all dodecyl isomers with branches (such as 2-methylundecyl, 3,5-dimethyldecyl, and the like). When represented by a structural formula C n H 2n+1 -(such as C6H 13 -, C 18 H 37 -) representing an alkyl group, by default it represents all isomers including the corresponding number of carbon atoms.

[0049] The above description of "alkyl" also applies to the alkyl groups in aralkyl, aralkylamino, alkylaryl, alkylamino (alkaminyl), and alcohol groups. Unless otherwise specified, "alkaminyl" as used herein refers to an alkyl group attached to an amino group, such as methylamino, ethylamino. When an alcohol group is referred to herein without specifying whether the alkyl portion is straight or branched, the reference is intended to encompass all carbon chain isomers of the alkyl group, e.g., "pentyl" in "pentanol" encompasses the straight chain, n-pentyl, as well as the branched structures 2-methylbutyl, 3-methylbutyl, 2,2-dimethylpropyl, etc.; the hydroxyl group can optionally be attached to any carbon atom in the alkyl chain (including primary, secondary, tertiary carbon atoms), e.g., a pentanol group can be 1-pentanol (hydroxyl attached to the end of the straight chain), 2-pentanol (hydroxyl attached to the second carbon in the straight chain), 3-methyl-2-butanol (hydroxyl attached to the secondary carbon of the branched alkyl group), etc.

[0050] Unless otherwise specified, "heteroalkyl" as used herein refers to an alkyl group comprising at least one heteroatom such as B, N, O, P, S, Si, and Se, and the like, including, but not limited to, oxaalkyl (e.g., methoxy, ethoxy, -CH2-O-CH3, -CH2-CH2-O-C2H5, -(CH2)6-O-(CH2)5CH3), azaalkyl (e.g., dimethylaminoethyl -CH2-CH2-N(CH3)2, aminopropyl -CH2-CH2-CH2-NH2, N,N-dimethylhexylamino -C6H 12 N(CH3)2), thiaalkyl (e.g., methylthio methyl -CH2-S-CH3, mercaptomethyl -CH2-CH2-CH2-SH), phosphooxaalkyl (e.g., -CH2-P(O)(OH)2), thiophosphinoalkyl (e.g., methyl ethyl thiophosphinoethyl CH3SO2CH2CH2-), sulfoxoalkyl (e.g., methyl ethyl sulfoxoethyl CH3CH2S(O)CH2-), silylalkyl (e.g., trimethylsilylmethyl -CH2-Si(CH3)3, ethoxysilyl ethyl -CH2-CH2-Si(OC2H5)3), and other heteroatom-containing alkyl groups (e.g., boron-containing -CH2-B(OH)2).

[0051] The above description of "heteroalkyl" also applies to the heteroalkyl groups in heteroalkylamino groups. Unless otherwise specified, "heteroalkylamino" as used herein refers to an alkylamino structure in which the carbon atoms of the alkyl group are replaced with or interrupted by other heteroatoms (e.g., oxygen, nitrogen, sulfur, phosphorus, etc.) other than carbon. In other words, an alkaminyl group containing a heteroatom.

[0052] Unless otherwise specified, "cycloalkyl" as used herein refers to saturated cyclic aliphatic hydrocarbons, which can be monocycloalkyl or polycycloalkyl; the monocycloalkyl includes but is not limited to cyclopropyl, cyclobutyl, cyclopentyl, 3-methylcyclopentyl, 2,3-dimethylcyclopentyl, cyclohexyl, 3-methylcyclohexyl, 4-methylcyclohexyl, 2,3-dimethylcyclohexyl, 3,4,5-trimethylcyclohexyl, 4-tert-butylcyclohexyl, cycloheptyl, cyclooctyl, adamantyl, etc.; the polycycloalkyl can be bridged cycloalkyl, spirocycloalkyl, or a structure formed by connecting multiple monocycloalkyls through alkyl groups, wherein the bridged cycloalkyl includes but is not limited to bicyclo[2.2.1]heptyl bicyclo[2.2.2]octyl etc., the spirocycloalkyl includes but is not limited to spiro[3.4]octyl, spiro[4.4]nonyl etc., and the structure formed by connecting multiple monocycloalkyls through alkyl groups is, for example,

[0053] The above description of "cycloalkyl" can also be applied to the cycloalkyl in cycloalkylcarbonyl and cycloalkylamino. Unless otherwise specified, "cycloalkylcarbonyl" as used herein refers to a group formed by connecting a cycloalkyl to a carbonyl (C=O), such as cyclohexylcarbonyl "Cycloalkylamino" as used herein refers to a group formed by connecting a cycloalkyl to an amino group, such as N-methylcyclohexylamino.

[0054] Unless otherwise specified, "heterocycloalkyl" as used herein refers to a cycloalkyl containing at least one heteroatom such as B, N, O, P, S, Si, and Se, etc., which includes but is not limited to tetrahydropyranyl tetrahydrothiopyranyl (7-oxabicyclo[2.2.1]heptyl), etc.

[0055] The above description of "heterocycloalkyl" can also be applied to the heterocycloalkyl in heterocycloalkylamino. Unless otherwise specified, "heterocycloalkylamino" as used herein refers to a group formed by replacing one or more carbon atoms in a cycloalkylamino with one or more heteroatoms (such as nitrogen, oxygen, sulfur, etc., non-carbon atoms).

[0056] "Cn~Cm certain group" as used herein refers to a certain group with carbon atom number n to m. For example, "C6~C30 aryl group" refers to an aryl group with carbon atom number 6 to 30.

[0057] In this document, the definition of "cover layer" is broad, including not only the literal covering structure, but also the same kind of layered structure that actually functions as a cover. Even if such a structure is expressed by other names, such as a flat layer, a contact layer in contact with the cathode, etc., as long as it achieves the purpose of the present application, it belongs to the category of cover layer referred to in the present application.

[0058] The present application provides a kind of cover layer material, comprising the compound shown in formula I and / or formula II:

[0059] In formula I, A1 and A2 are the same or different, independently five-membered ring or six-membered ring;A is fused with A1, A2 respectively into ring;R is hydrogen or the substituent of A, if R is the substituent of A, it can be mono-substituted or multi-substituted on any substitutable position of A;Ak1 is the substituent of A1, and is connected with nitrogen atom (N) in A1;Ak2 is the substituent of A2, and is connected with nitrogen atom (N) in A2.

[0060] When A1 and A2 are both five-membered ring, A is selected from substituted or unsubstituted C6-C30 aryl group, substituted or unsubstituted C3-C30 heteroaryl group, substituted or unsubstituted C6-C24 aryl group derivative, substituted or unsubstituted C3-C24 heteroaryl group derivative, cyclobutyl group;Ak1 and Ak2 are the same or different, independently selected from substituted or unsubstituted C1-C30 alkyl, substituted or unsubstituted C1-C30 heteroalkyl, substituted or unsubstituted C3-C30 cycloalkyl, substituted or unsubstituted C2-C30 heterocycloalkyl, substituted or unsubstituted C1-C30 alkylamine, substituted or unsubstituted C1-C30 heteroalkylamine, substituted or unsubstituted C3-C30 cycloalkylamine, substituted or unsubstituted C2-C30 heterocycloalkylamine, substituted or unsubstituted C3-C30 cycloalkylcarbonyl, or bonded into ring with adjacent atoms.

[0061] When A1 and A2 are different or both six-membered ring, A is selected from substituted or unsubstituted C6-C30 aryl group, substituted or unsubstituted C3-C30 heteroaryl group;Ak1 and Ak2 are the same or different, independently selected from substituted or unsubstituted C1-C30 alkyl, substituted or unsubstituted C1-C30 heteroalkyl, substituted or unsubstituted C3-C30 cycloalkyl, substituted or unsubstituted C2-C30 heterocycloalkyl, substituted or unsubstituted C1-C30 alkylamine, substituted or unsubstituted C1-C30 heteroalkylamine, substituted or unsubstituted C3-C30 cycloalkylamine, substituted or unsubstituted C2-C30 heterocycloalkylamine, or bonded into ring with adjacent atoms.

[0062] In formula II, A1 and A2 are the same or different, independently five-membered ring or six-membered ring;A is fused with A1, A2 respectively into ring;R is hydrogen or the substituent of A, if R is the substituent of A, it can be mono-substituted or multi-substituted on any substitutable position of A. Ar1 is the substituent of A1, and is connected with nitrogen atom (N) in A1;Ar2 is the substituent of A2, and is connected with nitrogen atom (N) in A2.

[0063] When A1and A2are both five-membered rings, A is selected from substituted or unsubstituted C6-C30aryl groups, substituted or unsubstituted C3-C30heteroaryl groups, cyclobutyl groups; Ar1and Ar2are the same or different, independently selected from substituted or unsubstituted C6-C24aryl groups, substituted or unsubstituted C3-C24heteroaryl groups.

[0064] When A1and A2are different or both six-membered rings, A is selected from substituted or unsubstituted C6-C30aryl groups, substituted or unsubstituted C3-C30heteroaryl groups; Ar1and Ar2are the same or different, independently selected from substituted or unsubstituted C6-C24aryl groups, substituted or unsubstituted C3-C24heteroaryl groups.

[0065] In formula I and formula II, R is selected from hydrogen, or one or more substituents: deuterium, fluorine, chlorine, bromine, cyano, isonitrile, fluorine-containing groups, nitro, substituted or unsubstituted C1-C30alkyl, substituted or unsubstituted C3-C30cycloalkyl, substituted or unsubstituted C1-C30heteroalkyl, substituted or unsubstituted C2-C30heterocycloalkyl, substituted or unsubstituted C1-C30alkylthio, substituted or unsubstituted C6-C30aryl, substituted or unsubstituted C2-C30heteroaryl, substituted or unsubstituted C1-C30keto, substituted or unsubstituted C2-C30alkoxycarbonyl, substituted or unsubstituted C6-C30aryloxycarbonyl, silyl, arylsilyl, ester phosphine oxide, sulfone, azaheteroaryl, carboxyl, ether groups.

[0066] Preferably, R is selected from hydrogen, or one or more substituents: hydrogen, deuterium, fluorine, chlorine, bromine, cyano, isonitrile, trifluoromethyl, nitro, substituted or unsubstituted C1-C15alkyl, substituted or unsubstituted C3-C15cycloalkyl, substituted or unsubstituted C1-C15alkoxy, substituted or unsubstituted C1-C15alkylthio, substituted or unsubstituted C6-C16aryl, substituted or unsubstituted C2-C15heteroaryl, substituted or unsubstituted C1-C15keto, substituted or unsubstituted C2-C15alkoxycarbonyl, substituted or unsubstituted C6-C15aryloxycarbonyl, silyl, arylsilyl, ester phosphine oxide, sulfone, azaheteroaryl, carboxyl, ether groups.

[0067] Any hydrogen atom on formula I and / or formula II is optionally substituted with deuterium. That is, the hydrogen atoms in formula I and / or formula II can be independently selected as to whether or not they are substituted with deuterium, with each hydrogen atom having the possibility of being substituted or not.

[0068] In some embodiments, the compound of formula I is selected from: the compound of formula II is selected from:

[0069] wherein A is selected from a substituted or unsubstituted C6-C30 aryl group, a substituted or unsubstituted C3-C30 heteroaryl group; R is selected from hydrogen, deuterium, a substituted or unsubstituted C1-C30 alkyl group, a substituted or unsubstituted C3-C30 cycloalkyl group, a substituted or unsubstituted C1-C30 heteroalkyl group, a substituted or unsubstituted C2-C30 heterocycloalkyl group, a substituted or unsubstituted C1-C10 fluoroalkyl group, a substituted or unsubstituted C1-C10 fluorocycloalkyl group, a substituted or unsubstituted C6-C30 aryl group, a substituted or unsubstituted C3-C30 heteroaryl group; Ak1and Ak2are the same or different, independently selected from a substituted or unsubstituted C1-C30 alkyl group, a substituted or unsubstituted C1-C30 heteroalkyl group, a substituted or unsubstituted C3-C30 cycloalkyl group, a substituted or unsubstituted C2-C30 heterocycloalkyl group, a substituted or unsubstituted C1-C30 alkylamine group, a substituted or unsubstituted C1-C30 heteroalkylamine group, a substituted or unsubstituted C3-C30 cycloalkylamine group, a substituted or unsubstituted C2-C30 heterocycloalkylamine group, or bonded to adjacent atoms to form a ring; Ar1and Ar2are the same or different, independently selected from a substituted or unsubstituted C6-C24 aryl group, a substituted or unsubstituted C3-C24 heteroaryl group.

[0070] Due to the presence of the cyclic imide structure containing nitrogen atom (N) and oxygen atom (O) in the nucleus of the compound, the cover layer material containing the compound can form a stronger interlocking force with the cathode. Meanwhile, the planar rigidity characteristic possessed by the cyclic imide structure can endow the material with a higher glass transition temperature, and further strengthen the interlocking force between the cover layer material and the cathode.

[0071] Preferably, when at least one of A, R, Ak1, Ak2, Ar1and Ar2is substituted, the substituents are independently selected from the group consisting of fluorine atom, trifluoromethyl, cyano, nitro, phosphorus oxy group, sulfone group, sulfoxide group, aryl group, nitrogen heteroaryl group, dimethyl, tert-butyl, isopropyl, carboxyl derivative group, or a combination of one or more thereof.

[0072] Preferably, A is selected from the following groups which are substituted or unsubstituted:

[0073] Preferably, Ar1and Ar2are independently selected from the following groups which are substituted or unsubstituted:

[0074] wherein * represents a connection site, specifically the position connected with the nitrogen atoms of A1and A2in formula II. Me represents a methyl group.

[0075] Preferably, Ak1 and Ak2 are independently selected from the group consisting of methyl, ethyl, propyl, isopropyl, butyl, tert-butyl, sec-butyl, pentyl, isopentyl, hexyl, cyclohexyl, adamantyl, substituted or unsubstituted:

[0076] wherein * represents a connection site, specifically a position connected to the nitrogen atom of A1 and A2 in Formula I; (C)n represents an alkyl group having n carbon atoms, and n is selected from 1, 2, 3, 4, 5, 6; Ar3 is selected from substituted or unsubstituted C6-C12 aryl group, substituted or unsubstituted C3-C12 heteroaryl group.

[0077] In some preferred embodiments, the compound of Formula I is selected from the group consisting of:

[0078] wherein Ad represents an adamantyl group; Ak2 is selected from the group consisting of adamantyl,

[0079] In some preferred embodiments, the compound of Formula II is selected from the group consisting of:

[0080] wherein Me represents a methyl group; Ar2 is selected from the group consisting of:

[0081] In some specific embodiments, the compound of Formula II is selected from the group consisting of:

[0082] In some specific embodiments, the compound of Formula I is selected from the group consisting of:

[0083] In some embodiments, A1 and A2 are both five-membered rings, A is a cyclobutyl group, and R is hydrogen; the compound of Formula I is selected from: the compound of Formula II is selected from:

[0084] In the formula I, Ak1and Ak2are the same or different and independently selected from the group consisting of substituted or unsubstituted C1-C30 alkyl, substituted or unsubstituted C1-C30 heteroalkyl, substituted or unsubstituted C3-C30 cycloalkyl, substituted or unsubstituted C2-C30 heterocycloalkyl, substituted or unsubstituted C3-C30 cycloalkylcarbonyl, substituted or unsubstituted C1-C30 alkylamino, substituted or unsubstituted C1-C30 heteroalkylamino, substituted or unsubstituted C3-C30 cycloalkylamino, substituted or unsubstituted C2-C30 heterocycloalkylamino, or bonded to adjacent atoms to form a ring;

[0085] In the formula II, Ar1and Ar2are the same or different and independently selected from the group consisting of substituted or unsubstituted C6-C24 aryl, substituted or unsubstituted C3-C24 heteroaryl.

[0086] The compound takes a cyclobutane diimide structure as a mother nucleus, the heteroatoms (O and N) introduced by the imide group are rich in lone pairs of electrons, which can form weak interactions with the cathode material, thereby improving the peel adhesion between the cover layer and the cathode. At the same time, the hydrogen bonds that may exist in the molecule can enhance the intermolecular forces, which synergistically enhance the aforementioned weak interactions, further improve the peel adhesion, even if the fluorine atom, fluorine-containing group, alkyl, heteroalkyl or alkenyl group and other groups are introduced into the molecule, the strong peel adhesion can still be maintained, and the above-mentioned groups can synergistically reduce the refractive index by adjusting the polarity of the molecule; on the other hand, the enhancement of intermolecular forces can further improve the Tg of the cover layer material and enhance the structural stability. In addition, the mother nucleus uses a cycloalkyl group as the central ring, which can further reduce the refractive index of the material.

[0087] The molecule of the compound can selectively contain or not contain fluorine atoms: if it contains fluorine atoms, it can effectively improve the technical problems of easy peeling and unsatisfactory Tg between the existing fluorine-containing material and the cathode through the aforementioned synergistic effect; if it does not contain fluorine atoms, not only can it fundamentally avoid the interface peeling and Tg deficiency problems caused by fluorine, but also can greatly reduce the preparation cost and provide a more environmentally friendly technical solution.

[0088] Preferably, the Ar1and Ar2are independently selected from the group consisting of substituted or unsubstituted phenyl, biphenyl, naphthyl, phenanthryl, anthryl, 9,9'-dimethylfluorenyl, 9,9'-diphenylfluorenyl, dibenzofuranyl, dibenzothiophenyl, carbazolyl, spirofluorenyl, spirofluorene xanthene, triphenylene, triazine group, phosphine oxide derivative group, sulfone derivative group, N-phenyl phthalimide group, benzophenone group.

[0089] Preferably, when substituted, the substituents of said Ar1and / or Ar2are independently selected from the group consisting of fluorine atoms, fluorine-containing groups, alkyl groups, heteroalkyl groups, alkenyl groups, hydroxyl groups, the following groups substituted or unsubstituted with fluorine atoms or fluorine-containing groups or alkyl groups or heteroalkyl groups or alkenyl groups: phenyl groups, naphthyl groups, pyridyl groups, phenol groups.

[0090] Preferably, said Ak1and Ak2are independently selected from the group consisting of substituted or unsubstituted C1-C20 alkyl groups, C5-C12 cycloalkyl groups, C5-C12 cycloalkylcarbonyl groups, C5-C18 cycloalkylamino groups.

[0091] Preferably, when substituted, the substituents of said Ak1and / or Ak2are independently selected from the group consisting of fluorine atoms, fluorine-containing groups, hydroxyl groups, the following groups substituted or unsubstituted with fluorine atoms or fluorine-containing groups or hydroxyl groups: C1-C6 alkyl groups, C6-C12 aryl groups, C3-C12 heteroaryl groups.

[0092] More preferably, said Ak1and Ak2are independently selected from the group consisting of methyl groups, ethyl groups, n-propyl groups, iso-propyl groups, n-butyl groups, iso-butyl groups, tert-butyl groups, sec-butyl groups, n-pentyl groups, iso-pentyl groups, n-hexyl groups, iso-hexyl groups, dodecyl groups, octadecyl groups, cyclopentyl groups, cyclohexyl groups, adamantyl groups, wherein the * represents a point of attachment, in particular a position of attachment to the nitrogen atoms of A1and A2in formula I. (C)n represents an alkyl group having n carbon atoms, and n is selected from the group consisting of integers from 1 to 6. Ar3is selected from the group consisting of substituted or unsubstituted C6-C12 aryl groups, substituted or unsubstituted C3-C12 heteroaryl groups, and, when substituted, the substituents are selected from the group consisting of C6-C12 aryl groups, C3-C12 heteroaryl groups.

[0093] More preferably, said Ak1and Ak2are independently selected from the group consisting of dodecyl groups, octadecyl groups, pentanol groups, cyclopentyl groups, cyclohexyl groups, adamantyl groups,

[0094] In some preferred embodiments, the compound of formula I is selected from the group consisting of:

[0095] In the above formula, Ad represents an adamantyl group; C 12 H 25 represents a dodecyl group, C 18 H 37 represents an octadecyl group; Ak2is selected from the group consisting of: adamantyl groups, Dodecyl, octadecyl, pentyl. More preferably, Ak1 and Ak2 are the same for ease of synthesis and cost reduction.

[0096] In some preferred embodiments, the compound of Formula II is selected from the group consisting of:

[0097] In the above formula, Ar2 is selected from phenyl, naphthyl, phenanthryl, dibenzofuranyl, 9,9'-dimethylfluorenyl, carbazolyl, spirofluorenyl, spirofluorenyloxepinyl, phenyl-substituted triazinyl, phosphine oxide derivative group, sulfone derivative group, pyridine-substituted phenyl, naphthalene-substituted phenyl, 9,9'-diphenylfluorenyl, N-phenylphthalimide group, benzophenone group, hydroxyl-substituted biphenyl group, phenyl-substituted anthracene group. More preferably, Ar2 and Ar1 are the same for ease of synthesis and cost reduction.

[0098] It should be noted that the connection sites of Ar1, Ar2, Ak1, Ak2 and the N in the imide group have little effect on the refractive index and adhesion, so the present application does not make special restrictions on these connection sites.

[0099] In some specific embodiments, the cover layer material comprises one or more of the following compounds:

[0100] In some embodiments, in the formula I, A1 and A2 are both five-membered rings; the compound of Formula I is selected from: wherein:

[0101] A is selected from a substituted or unsubstituted C6-C24 aryl group or a derivative thereof, a substituted or unsubstituted C3-C24 heteroaryl group or a derivative thereof;

[0102] Ak1 and Ak2 are the same or different, and are independently selected from a substituted or unsubstituted C1-C30 alkyl group, a substituted or unsubstituted C1-C30 oxaalkyl group, a substituted or unsubstituted C1-C30 thiaalkyl group, a substituted or unsubstituted C1-C30 nitaalkyl group, a substituted or unsubstituted C1-C30 phosphine oxide alkyl group, a substituted or unsubstituted C1-C30 sulfone-thiaalkyl group, a substituted or unsubstituted C1-C30 sulfoxide-thiaalkyl group; the Ak1 and Ak2 provide flexibility to the compound;

[0103] R is selected from hydrogen, deuterium, fluorine, a fluorine-containing group, a substituted or unsubstituted C1-C30 alkyl group, a substituted or unsubstituted C3-C30 cycloalkyl group, a substituted or unsubstituted C1-C30 heteroalkyl group, a substituted or unsubstituted C2-C30 heterocycloalkyl group, a substituted or unsubstituted C6-C30 aryl group, a substituted or unsubstituted C3-C30 heteroaryl group.

[0104] The introduction of cyclic imide structure can optimize the refractive index and peel adhesion of the material, but due to the rigid properties of cyclic imide, the evaporation port is prone to be blocked in the vacuum evaporation process due to the sublimation properties, affecting the stability of the film forming process. The application further introduces chain alkyl (Ak1 and Ak2) on the basis of the cyclic imide structure, which achieves unexpected technical effects: the compound presents a good melting state in the vacuum evaporation process, which can effectively avoid the problem of easy blockage of evaporation, and ensure the continuity of the film forming process; at the same time, the introduction of alkyl chain does not weaken the strong interfacial force between the cover layer and the cathode, and can further reduce the refractive index through molecular polarity regulation. The above improvement realizes the synergistic improvement of process adaptability, optical performance and interfacial bonding performance of the material.

[0105] Preferably, the compound represented by formula I has at least one of the following characteristics (1) to (4):

[0106] (1) A is selected from a substituted or unsubstituted C6-C18 aryl group or a derivative thereof;

[0107] (2) Ak1 and Ak2 are the same or different, and are independently selected from a substituted or unsubstituted C1-C20 alkyl, a substituted or unsubstituted C1-C20 oxaalkyl, and a substituted or unsubstituted C1-C20 azaalkyl;

[0108] (3) R is selected from hydrogen, deuterium, fluorine, a substituted or unsubstituted C1-C20 fluoroalkyl, and a substituted or unsubstituted C1-C20 alkyl;

[0109] (4) A, Ak1, Ak2 and R are each independently in an unsubstituted or substituted state; if in a substituted state, the substituent is independently selected from deuterium, fluorine, a fluorine-containing group, a C1-C10 alkyl, a cyano group, a nitro group, a hydroxyl group, a phosphorus oxy group, a sulfoxide group, an azaheteroaryl group, and a carboxyl derivative group.

[0110] Further preferably, the compound represented by formula I has at least one of the following characteristics 1) to 4):

[0111] 1) A is selected from a substituted or unsubstituted C6-C12 aryl group, a substituted or unsubstituted C6-C12 ether aryl derivative group, a substituted or unsubstituted C6-C12 sulfone aryl derivative group, and a substituted or unsubstituted C6-C18 phosphorus oxy aryl derivative group;

[0112] 2) Ak1 and Ak2 are the same or different, and are independently selected from a substituted or unsubstituted C1-C18 alkyl, a substituted or unsubstituted C1-C18 oxaalkyl, and a substituted or unsubstituted C1-C18 azaalkyl;

[0113] 3) R is selected from the group consisting of hydrogen, deuterium, fluorine, substituted or unsubstituted C1-C10 fluoroalkyl, substituted or unsubstituted C1-C10 alkyl;

[0114] 4) A, Ak1, Ak2 and R are each independently unsubstituted or substituted; if substituted, the substituents are independently selected from the group consisting of deuterium, fluorine, C1-C10 fluoroalkyl, C1-C10 alkyl, cyano, nitro, hydroxyl, phosphoroxy, sulfoxide, C3-C12 nitrogen heteroaryl, carboxyl derivative groups.

[0115] More preferably, the compound of formula I has at least one of the following features i) to iv):

[0116] i) A is selected from the group consisting of substituted or unsubstituted: wherein (*)4 denotes four attachment sites made up of two pairs of optionally positioned adjacent attachment sites;

[0117] ii) Ak1 and Ak2 are the same or different and independently selected from the group consisting of substituted or unsubstituted C3-C18 alkyl, substituted or unsubstituted C1-C10 oxaalkyl, substituted or unsubstituted C1-C10 azaalkyl;

[0118] iii) R is selected from the group consisting of hydrogen, deuterium, fluorine, C1-C10 fluoroalkyl;

[0119] iv) A, Ak1, Ak2 and R are each independently unsubstituted or substituted; if substituted, the substituents are independently selected from the group consisting of deuterium, fluorine, C1-C10 fluoroalkyl, C1-C10 alkyl, hydroxyl.

[0120] As an example, in feature i), A can be selected from the group consisting of substituted or unsubstituted:

[0121] Further preferably, feature ii) is defined as Ak1 and Ak2 being the same or different and independently selected from the group consisting of substituted or unsubstituted C3-C18 chain alkyl, substituted or unsubstituted 6-(pentyloxy)hexyl, substituted or unsubstituted N,N-dimethylhexylamino; still further preferably, feature ii) is defined as Ak1 and Ak2 being the same or different and independently selected from the group consisting of substituted or unsubstituted propyl, substituted or unsubstituted butyl, substituted or unsubstituted pentyl, substituted or unsubstituted hexyl, substituted or unsubstituted heptyl, substituted or unsubstituted dodecyl, substituted or unsubstituted octadecyl, substituted or unsubstituted 6-(pentyloxy)hexyl, substituted or unsubstituted N,N-dimethylhexylamino.

[0122] In some preferred embodiments, the compound of formula I is selected from the group consisting of:

[0123] in which C 18 H 37 represents octadecyl, C6H 13 represents hexadecyl; Ak2 is selected from octadecyl, hexadecyl, 6-(pentyloxy)hexyl N,N-dimethylhexylamino n-dodecyl monofluorinated n-dodecyl (e.g. tert-butyl n-butyl n-heptyl tert-butylethanoyl n-pentyl 6-hydroxyhexyl n-hexyl 1-ethylbutyl 2,3-dihydroxypropyl propyl

[0124] In some embodiments, for the sake of synthesis, Ak1 and Ak2 are preferably the same.

[0125] In some specific embodiments, the compound of Formula I is selected from the group consisting of:

[0126] The present application also provides a compound, which is a compound of Formula I and / or Formula II as described previously. The relevant descriptions of Formula I and Formula II as described previously apply to the present compound, which will not be repeated here.

[0127] The present application also provides an organic light-emitting device, which comprises a first electrode, an organic layer, a second electrode and a capping layer structure stacked in sequence, and the capping layer structure comprises a capping layer material as described previously or a compound as described previously.

[0128] In some preferred embodiments, the capping layer structure comprises a low refractive index capping layer and a high refractive index capping layer located on the low refractive index capping layer; wherein the low refractive index capping layer comprises a capping layer material as described previously or a compound as described previously, and the high refractive index capping layer has a refractive index of 1.90 or more for light of a wavelength of 460 nm. When this capping layer structure is applied to an organic light-emitting device, the luminous efficiency and color purity of the device can be effectively improved.

[0129] In some preferred embodiments, the high refractive index capping layer has a refractive index of 1.90-2.50 for light of 460 nm wavelength. For example, the refractive index can be 1.90, 1.95, 1.95, 2.00, 2.10, 2.15, 2.20, 2.25, 2.30, 2.35, 2.40, 2.45, 2.50, or a specific value within a sub-range defined by any of the above values. More preferably, the high refractive index capping layer has a refractive index of 2.20.

[0130] In some preferred embodiments, the low refractive index capping layer has a refractive index of 1.40-1.70 for light of 460 nm wavelength. For example, the low refractive index capping layer can have a refractive index of 1.40, 1.41, 1.42, 1.43, 1.44, 1.45, 1.46, 1.47, 1.48, 1.49, 1.50, 1.51, 1.52, 1.53, 1.54, 1.55, 1.56, 1.57, 1.58, 1.59, 1.60, 1.61, 1.62, 1.63, 1.64, 1.65, 1.66, 1.67, 1.68, 1.69, 1.70, or a specific value within a sub-range defined by any of the above values. For example, the low refractive index capping layer can have a refractive index of 1.40-1.56, 1.40-1.60, 1.45-1.50, 1.50-1.65, or 1.52-1.61.

[0131] In some preferred embodiments, the high refractive index capping layer comprises one or more of an inorganic compound and an organic compound, wherein the inorganic compound comprises at least one of SiOx, SiNy, ZnS, ZnSe, ZrO, TiO2, and x and y are independently selected from an integer of 1-4. The organic compound comprises one or more of an arylamine derivative, a carbazole derivative, a benzimidazole derivative, a triazole derivative. More preferably, the organic compound comprises at least one of the following compounds:

[0132] Specifically, the first electrode can be an anode, and the second electrode can be a cathode.

[0133] In some preferred embodiments, the low refractive index capping layer in the capping layer structure is adjacent to the second electrode.

[0134] The organic layer can be a single layer structure, or a multi-layer series structure with two or more organic layers laminated. The organic layer can comprise at least one of a hole injection layer, a hole transport layer, an electron blocking layer, a light emitting layer, a hole blocking layer, an electron transport layer, an electron injection layer.

[0135] In some preferred embodiments, the organic layer comprises, in order, a hole injection layer, a hole transport layer, an emission layer, an electron transport layer, and an electron injection layer.

[0136] With regard to the specific construction of the device described in the present application, reference can be made to the priority document of the present case for incorporation or merger.

[0137] The technical solutions of the present application will be described clearly and completely in combination with the embodiments of the present application. If not otherwise specified, the reagents and raw materials used can be purchased through commercial channels. The experimental methods not specified in the following examples are generally determined according to national standards. If there is no corresponding national standard, the international standard, the general method and condition, or the condition suggested by the manufacturer, or the product instruction is selected.

[0138] The initial raw materials and solvents of the following examples are purchased from the National Medicine, and some commonly used OLED intermediates and other products are purchased from the OLED intermediate manufacturers in China; HPLC data is determined by Shimadzu LC 20AD high performance liquid chromatograph; LC-MS (liquid chromatography-mass spectrometry) is tested on the H-class+SQD2 model instrument of Waters Corporation.

[0139] Compound preparation example

[0140] Example 1

[0141] Preparation of compound 1

[0142] Put pyromellitic dianhydride 1-A (21.8 g, 100 mmol) and acetic acid (AcOH, 250 mL) in a reaction bottle, cool to 5℃ in an ice bath, slowly add compound 1-B (50.38 g, 220 mmol). After the addition is complete, heat to 130℃, and react for 4 hours. Then slowly pour the reaction mixture into 250 mL of water, and a large amount of solid is precipitated. Filter, and wash the filter cake with water. Recrystallize the solid with ethanol, filter, and dry to obtain 58.2 g of white solid product compound, with a yield of 91%, HPLC purity: 99.9%, and the product is confirmed as the target product. LC MS: M / Z 640.03 (M+).

[0143] Examples 2-24

[0144] Prepare compounds 2-20 and compounds 22-25 shown in the following table according to the preparation method of Reference Example 1.

[0145] Table 1 reactants and products

[0146] 90° peel performance test

[0147] The film was coated according to the following structure: ITO substrate (40mm*40mm) / Ag (200nm) / compound film layer (1200nm), the material of the compound film layer was selected from the compounds 1-20, 22-25, CPL-1, CPL-3 of the present application, wherein the molecular structures of CPL-1, CPL-3 please refer to the device preparation example.

[0148] One side of the test tape (model: 3M681) was bonded on the coated layer, and the other side was clamped with a clamp, and the test was carried out at a speed of 200mm / min. After the start of the test, the first 5mm length of the test value was ignored, then 2mm length was peeled off from the ITO substrate, and the parallel test was carried out for 3 times, the average value of the adhesion test value was taken, and was set as the peel adhesion value, and the test results were shown in Table 2.

[0149] Table 2 Peel performance test results

[0150] As can be seen from Table 2, compared with compounds CPL-1 and CPL-3, the peel adhesion of compounds 1-20, 22-25 of the present application with cathode Ag was significantly improved, so the cover layer prepared by using compounds 1-20, 22-25 of the present application was not easy to cause interlayer peeling with cathode Ag.

[0151] Tg test

[0152] The samples of compounds 1-20, 22-25, CPL-1, CPL-3 of the present application were tested by using differential scanning calorimeter DSC (American TA Instruments Co., Ltd., model DSC25) to determine the glass transition temperature (Tg), and the test results were shown in Table 3.

[0153] Table 3 Tg test results

[0154] As can be seen from Table 3, compared with compounds CPL-1 and CPL-3, compounds 1-20, 22-25 of the present application had higher Tg, and when the compounds 1-20, 22-25 were used to prepare organic light-emitting devices, the device lifetime could be improved.

[0155] Example 25

[0156] Preparation of compound 1-1

[0157] Into a reaction flask was added dianhydride 1-A (19.6 g, 100 mmol) and acetic acid (250 mL) and cooled to 5 °C in an ice bath. 1-C (20.46 g, 220 mmol) was added slowly. After the addition was complete, the reaction was heated to 130 °C for 4 h. The reaction mixture was then slowly poured into 250 mL of water and a large amount of solid precipitated. The solid was filtered and the filter cake was washed with water. The solid was recrystallized from ethanol, filtered and dried. This resulted in 30.10 g of a white solid in 87% yield with a HPLC purity of 99.9% and the product was confirmed as the target product with LCMS: M / Z 346.10 (M+).

[0158] Examples 26-52

[0159] The compounds 2-1 to 28-1 shown in the following table were prepared according to the preparation method of Reference Example 25.

[0160] Table 4 Reactants and products

[0161] 90° peel performance test

[0162] The film was coated according to the following structure: ITO substrate (40 mm*40 mm) / Ag (200 nm) / compound film layer (1200 nm), and the material of the compound film layer was selected from the compounds 1-1 to 28-1, CPL-1, CPL-3 of the present application, wherein the molecular structures of CPL-1 and CPL-3 are shown in the device preparation example.

[0163] One side of the test tape (model: 3M681) was bonded to the coated film layer, and the other side of the tape was clamped with a clamp, and the test was carried out at a speed of 200 mm / min. After the test started, the first 5 mm of the test value was ignored, then 2 mm was peeled off from the ITO substrate, and the parallel test was carried out for 3 times, the average value of the adhesion test value was taken as the peel adhesion value, and the test results are shown in the following table.

[0164] Table 5 Peel performance test results

[0165] As can be seen from Table 5, compared with compounds CPL-1 and CPL-3, the peel adhesion of the compounds 1-1 to 28-1 of the present application and the cathode material has been significantly improved, and the covering layer containing the compound can form a strong adhesion between the cathode, and is not easy to fall off.

[0166] Tg test

[0167] The samples of the compounds 1-1 to 28-1, CPL-1, CPL-3 of the present application were tested by using a differential scanning calorimeter DSC (TA Instruments, Inc., Model DSC25) to determine their Tg, and the test results are shown in the following table.

[0168] Table 6 Tg test results

[0169] As can be seen from Table 6, the compounds 1-1 to 28-1 of the present application have higher Tg compared with the compounds CPL-1 and CPL-3, and the cover layer prepared from the compounds has good thermodynamic reliability, which is beneficial to improve the device life.

[0170] Example 53

[0171] Preparation of compound 1-2

[0172] Put pyromellitic dianhydride 1-A (21.8 g, 100 mmol) and acetic acid (250 mL) in a reaction bottle, and cool to 5°C in an ice bath, slowly add compound 1-D (53.9 g, 200 mmol). After the addition is complete, heat to 130°C, and react for 4 hours. Then, slowly pour the reaction mixture into 500 mL of water, and a large amount of solid is precipitated. Filter, and wash the filter cake with water. Recrystallize the solid with ethanol, filter, and dry. Obtain 62.0 g of white solid, with a yield of 86%, HPLC purity: 99.9%, and the product is confirmed as the target product LC MS: M / Z 720.58 (M+).

[0173] Examples 54 to 62

[0174] Prepare the compounds shown in the following table according to the preparation method of Reference Example 53.

[0175] Table 7 Reactants and products

[0176] 90° peeling performance test

[0177] Coating according to the following structure: ITO substrate (40 mm*40 mm) / Ag (200 nm) / compound film layer (1200 nm), and the compound film layer material is selected from the compounds 1-2 to 10-2, CPL-1, CPL-4, CPL-5 of the present application, wherein the molecular structures of CPL-1, CPL-4, and CPL-5 are shown in the Device Preparation Example.

[0178] The test tape (model: 3M681) was bonded on one side of the coating layer, and the other side was clamped with a clamp, and the test was carried out at a speed of 200 mm / min. After the test started, the first 5 mm length of the test value was ignored, then 2 mm length was peeled off from the ITO substrate, and the average value of the adhesion test value was taken as the peeling adhesion value, and the test results were as follows.

[0179] Table 8 Peeling performance test results

[0180] As can be seen from Table 8, compared with the existing fluorine-containing compound (CPL-1), the peeling adhesion of the compounds 1-2 to 10-2 of the application to the cathode Ag has been significantly improved; in particular, although the compound 5-2 of the application introduces a fluorine atom, it still exhibits strong peeling adhesion; further, the Ak1 and Ak2 of the compounds of the application are chain alkyl, which has significantly improved the peeling adhesion compared with the Ak1 and Ak2 being cycloalkyl (CPL-4), and compared with the Ak1 and Ak2 being aryl (CPL-5), the peeling adhesion of the compounds except the compound 5-2 which introduces a fluorine atom has been significantly improved.

[0181] Vacuum sublimation test

[0182] 5.0 g of the sample was placed in a vacuum sublimation instrument for OLED (model: Svac-Sub100), and the pressure was reduced to a vacuum degree less than 5.0 x 10 -3 Pa, and the sample was slowly heated and observed in the sublimation boat, and recorded as a melting type or a sublimation type. Among them, "melting type" means that the sample is first converted from solid to liquid (i.e. melting) under the condition of reduced pressure and vacuum heating, and then further converted to gaseous state; "sublimation type" means that the sample is directly gasified under the condition of reduced pressure and vacuum heating.

[0183] Table 9 Vacuum sublimation test results

[0184] As can be seen from Table 9, after replacing Ak1 and Ak2 with chain alkyl instead of cycloalkyl (CPL-4) or aryl (CPL-5), the sublimation state of the molecule is changed from sublimation type to melting type, which can effectively avoid the problem of equipment blockage caused by direct sublimation during evaporation process, significantly improve the stability of evaporation process and film forming quality, indicating that the compounds of the application are more suitable for evaporation process of OLED materials.

[0185] Device preparation example

[0186] The compounds involved in the following device preparation example are as follows:

[0187] Example 63

[0188] Referring to FIG. 1, the method of preparing an organic light emitting device according to the present embodiment includes the following steps:

[0189] (1) After ultrasonic washing of the alkali-free glass 1 in isopropyl alcohol for 15 minutes, the alkali-free glass 1 was treated with ultraviolet ozone for 30 minutes in the atmosphere, and then a 100 nm silver (Ag) film and a 10 nm ITO film (not distinguished in the figure) were sequentially formed on the alkali-free glass 1 using a shadow mask method, thereby forming a reflective anode 2.

[0190] (2) The reflective anode 2 was subjected to ultraviolet ozone washing treatment for 10 minutes, and a hole injection layer 3 (NPD and F4-TCNQ at a weight ratio of 97:3, 50 nm), a hole transport layer 4 (NPD, 80 nm), a blue light emitting layer 5 (BH and BD at a weight ratio of 97:3, 20 nm), an electron transport layer 6 (Alq3, 35 nm), an electron injection layer 7 (LiF, 1 nm), and a semi-transparent cathode 8 (Mg and Ag at a weight ratio of 10:1, 15 nm) were sequentially deposited on the reflective anode 2 by vacuum deposition.

[0191] (3) On the semi-transparent cathode 8, a low refractive index capping layer 91 of 10 nm in thickness was formed by depositing the compound 1 prepared in Example 1, and a high refractive index capping layer 92 of 50 nm in thickness was formed by depositing the compound CPL-2 on the low refractive index capping layer 91.

[0192] (4) The organic light emitting device was prepared by packaging the alkali-free glass sealing plate with an epoxy adhesive in a glove box under a dry nitrogen atmosphere.

[0193] Examples 64 to 86

[0194] The organic light emitting device was prepared in the same manner as in Example 63, except that the compound 2 to 20 and the compound 22 to 25 prepared in the foregoing examples were used instead of the compound 1 when forming the low refractive index capping layer 91.

[0195] Comparative Example 1

[0196] The only difference from Example 63 is that the low refractive index capping layer 91 was not provided.

[0197] Comparative Example 2

[0198] The only difference from Example 63 is that the high refractive index capping layer 92 was not provided.

[0199] Comparative Example 3

[0200] The only difference from Example 63 is that the material of the low refractive index capping layer 91 was the compound CPL-1.

[0201] Comparative Example 4

[0202] The only difference from Example 63 is that the material of the low-refractive-index cover layer 91 is compound CPL-3.

[0203] Device performance test

[0204] The refractive index of the cover layer was tested by an ellipsometry (J.A. Woollam Co. Inc M-2000). The brightness and color purity of the device were tested by a luminance meter (CS1000, Konica Minolta Optics, Inc.) with a spectroradiometer under the condition of 10 mA / cm2direct current and room temperature and normal pressure. The luminous efficiency and color purity were obtained from the test results as shown in the following table. 2

[0205] Table 10 Luminous efficiency and color purity results

[0206] In Table 10, n1 refers to the refractive index of the low-refractive-index cover layer for 460 nm wavelength light, and n2 refers to the refractive index of the high-refractive-index cover layer for 460 nm wavelength light. According to the results of Comparative Example 1 and Comparative Example 2, when the high-refractive-index cover layer or the low-refractive-index cover layer is used alone, the luminous efficiency of the device is low, and the color purity is not high. According to the results of Examples 63 to 86 and Comparative Examples 3 to 4, although Comparative Example 3 and Comparative Example 4 are provided with both the high-refractive-index cover layer and the low-refractive-index cover layer, the luminous efficiency of the device is improved, but the color purity of the device is still not high. When the material of the high-refractive-index cover layer is kept unchanged, and the low-refractive-index cover layer is prepared by using the compound of the present application, not only the luminous efficiency of the device can be improved, but also the color purity can be improved.

[0207] Therefore, the low-refractive-index cover layer can be prepared by using the compound of the present application, and the low-refractive-index cover layer has strong adhesion between the low-refractive-index cover layer and the cathode, is not easy to fall off between layers, and has a high Tg. At the same time, when the low-refractive-index cover layer and the high-refractive-index cover layer together form the cover layer structure of the organic light-emitting device, the luminous efficiency and color purity of the device can be significantly improved.

[0208] Example 87

[0209] Referring to FIG. 1, the method for preparing the organic light-emitting device of the present embodiment includes the following steps:

[0210] (1) After the alkali-free glass 1 is ultrasonically washed in isopropyl alcohol for 15 minutes, the alkali-free glass 1 is treated with ultraviolet ozone in the atmosphere for 30 minutes, and then a 100 nm silver (Ag) film and a 10 nm ITO film (not distinguished in the figure) are formed on the alkali-free glass 1 in sequence by a sputtering method, to form a reflective anode 2. ​

[0211] (2) The reflective anode 2 was subjected to ultraviolet ozone washing treatment for 10 minutes, and a hole injection layer 3 (NPD and F4-TCNQ at a weight ratio of 97:3, 50 nm), a hole transport layer 4 (NPD, 80 nm), a blue light emitting layer 5 (BH and BD at a weight ratio of 97:3, 20 nm), an electron transport layer 6 (Alq3, 35 nm), and an electron injection layer 7 (LiF, 1 nm) were sequentially deposited on the reflective anode 2 by vacuum deposition, followed by co-deposition of Mg and Ag (at a weight ratio of 10:1, 15 nm) as a semi-transparent cathode 8.

[0212] (3) On the semi-transparent cathode 8, a low-refractive index capping layer 91 was formed to a thickness of 10 nm by deposition of the compound 1-1 prepared in Example 25, and a high-refractive index capping layer 92 was deposited on the low-refractive index capping layer 91 to a thickness of 50 nm by deposition of the compound CPL-2.

[0213] (4) The organic light emitting device was prepared by packaging the alkali-free glass sealing plate with an epoxy resin adhesive in a glove box under a dry nitrogen atmosphere.

[0214] Examples 88 to 114

[0215] The organic light emitting device was prepared by the same method as in Example 87, except that the compound 1-1 was replaced by the compounds 2-1 to 28-1 prepared in the foregoing examples, respectively, in forming the low-refractive index capping layer 91.

[0216] Comparative Example 5

[0217] The difference from Example 87 is only that the low-refractive index capping layer 91 was not provided.

[0218] Comparative Example 6

[0219] The difference from Example 87 is only that the high-refractive index capping layer 92 was not provided.

[0220] Comparative Example 7

[0221] The difference from Example 87 is only that the material of the low-refractive index capping layer 91 was the compound CPL-1.

[0222] Comparative Example 8

[0223] The difference from Example 87 is only that the material of the low-refractive index capping layer 91 was the compound CPL-3.

[0224] Device performance test

[0225] The refractive index of the cover layer at a wavelength of 460 nm was measured using an ellipsometry spectrum (J.A. Woollam Co. Inc M-2000). The brightness and color purity of the device were measured using a spectroradiometric luminance meter (CS1000, Konica Minolta) under the conditions of 10 mA / cm 2

[0226] Table 11 Luminescent efficiency and color purity results

[0227] In Table 11, n1 refers to the refractive index of the cover layer for light at a wavelength of 460 nm, and n2 refers to the refractive index of the high-refractive cover layer for light at a wavelength of 460 nm. According to the comparison results of Examples 87-114 and Comparative Examples 5, 7-8, it can be seen that the compounds 1-1-28-1 of the present application can effectively reduce the refractive index of the film layer.

[0228] Further, according to the results of Comparative Example 5 and Comparative Example 6, it can be seen that when the high-refractive cover layer is used alone or the low-refractive cover layer is used alone, the luminescent efficiency of the device is low, and the color purity is not high. Although Comparative Example 7 and Comparative Example 8 are provided with both a low-refractive cover layer and a high-refractive cover layer, the luminescent efficiency of the device is improved, but the color purity of the device is still not high. When the material of the high-refractive cover layer is kept unchanged, and the compound of the present application is used to replace the existing fluorine-containing material to form a low-refractive cover layer, the luminescent efficiency and color purity of the device can be improved, and the device has both high luminescent efficiency and high color purity.

[0229] Therefore, when the compound of the present application is used to prepare the cover layer of the organic light-emitting device, the peel adhesion between the cover layer and the cathode and the Tg of the cover layer can be improved while maintaining a low refractive index. Further, when the compound is used to prepare a low-refractive cover layer, and a high-refractive cover layer is provided on the low-refractive cover layer, the luminescent efficiency and color purity of the device can be simultaneously improved.

[0230] Example 115

[0231] Referring to FIG. 1, the method for preparing the organic light-emitting device of the present embodiment includes the following steps:

[0232] (1) The alkali-free glass 1 was ultrasonically washed in isopropyl alcohol for 15 minutes, then treated with ultraviolet ozone in the atmosphere for 30 minutes, and then a 100 nm silver (Ag) film and a 10 nm ITO film (not distinguished in the figure) were sequentially formed on the alkali-free glass 1 using a sputtering method, to form a reflective anode 2.

[0233] ​(2) The reflective anode 2 was subjected to ultraviolet ozone washing treatment for 10 minutes, and a hole injection layer 3 (NPD and F4-TCNQ at a weight ratio of 97:3, 50 nm), a hole transport layer 4 (NPD, 80 nm), a blue light emitting layer 5 (BH and BD at a weight ratio of 97:3, 20 nm), an electron transport layer 6 (Alq3, 35 nm), an electron injection layer 7 (LiF, 1 nm), and Mg and Ag (at a weight ratio of 10:1, 15 nm) as a semi-transparent cathode 8 were sequentially deposited on the reflective anode 2 by vacuum evaporation.

[0234] (3) On the semi-transparent cathode 8, a low-refractive index cover layer 91 was formed to a thickness of 10 nm by depositing the compound 1-2 prepared in Example 53, and a high-refractive index cover layer 92 was formed to a thickness of 50 nm by depositing the compound CPL-2 on the low-refractive index cover layer 91.

[0235] (4) The organic light emitting device was prepared by packaging the alkali-free glass sealing plate with an epoxy resin adhesive in a glove box under a dry nitrogen atmosphere.

[0236] Examples 116 to 124

[0237] The organic light emitting device was prepared by the same method as in Example 115, except that the compound 1-2 was replaced by the compounds 2-2 to 10-2 prepared in the foregoing examples, respectively, when forming the low-refractive index cover layer 91.

[0238] Comparative Example 9

[0239] The difference from Example 115 is only that the low-refractive index cover layer 91 was not provided.

[0240] Comparative Example 10

[0241] The difference from Example 115 is only that the high-refractive index cover layer 92 was not provided.

[0242] Comparative Example 11

[0243] The difference from Example 115 is only that the material of the low-refractive index cover layer 91 was the compound CPL-4.

[0244] Comparative Example 12

[0245] The difference from Example 115 is only that the material of the low-refractive index cover layer 91 was the compound CPL-5.

[0246] Comparative Example 13

[0247] The difference from Example 115 is only that the material of the low-refractive index cover layer 91 was the compound CPL-1.

[0248] Device performance test

[0249] The refractive index of the cover layer at a wavelength of 460 nm was measured using an ellipsometry spectrum (J.A. Woollam Co. Inc M-2000). The luminance and color purity of the organic light-emitting device prepared above were measured using a spectroradiometric luminance meter (CS1000, Konica Minolta) under a load of 10 mA / cm 2

[0250] Table 12 Luminescent efficiency and color purity results

[0251] In Table 12, n1 is the refractive index of the low refractive index cover layer for light at a wavelength of 460 nm, and n2 is the refractive index of the high refractive index cover layer for light at a wavelength of 460 nm. The data show that the low refractive index cover layer of the examples of the present application has a lower refractive index compared to Comparative Examples 9, 11-13. Among them, the compound (CPL-4) of Comparative Example 11 and the compound (CPL-5) of Comparative Example 12 can significantly reduce the refractive index of the cover layer compared to the existing fluorine-containing compound (CPL-1) used in Comparative Example 13, and after replacing Ak1 and Ak2 in CPL-4 and CPL-5 with cycloalkyl and aryl, i.e., compounds 1-2, 2-2, 4-2, and 8-2-10-2 of the present application, the refractive index of the cover layer is further reduced.

[0252] According to the results of Comparative Example 9 and Comparative Example 10, when only the high refractive index cover layer or the low refractive index cover layer is used, the luminescent efficiency of the device is low, and the color purity is not high. Comparative Examples 11-13 have both high refractive index cover layer and low refractive index cover layer, which improves the luminescent efficiency and color purity of the device, and the improvement is more obvious in Comparative Examples 11-12. When the material of the high refractive index cover layer is kept unchanged, the lowest luminescent efficiency (compound 5-2) is also the same as that of Comparative Example 11 when the low refractive index cover layer is prepared using the compound of the present application, and the high color purity is also maintained.

[0253] ​Therefore, compared with the existing fluorine-containing materials, the compound of the present application can reduce the refractive index of the cover layer, while improving the peeling adhesion between the cover layer and the cathode, reducing the risk of interlayer peeling, and effectively avoiding the phenomenon of equipment blockage caused by the sublimation characteristics of the material during vacuum evaporation by enhancing the flexibility of the molecules, so that the material is in a stable molten state during evaporation to improve the film forming quality; the composite structure composed of the low refractive index cover layer and the high refractive index cover layer prepared by using the compound can synergistically improve the luminous efficiency and color purity of the organic light-emitting device. Therefore, the compound of the present application exhibits significant advantages in optical performance, interface stability and process adaptability, and is more suitable as an OLED cover layer material.

[0254] The above description of the embodiments is to facilitate the understanding and application of the present application by those of ordinary skill in the art. Those skilled in the art can easily make various modifications to these embodiments and apply the general principles described herein to other embodiments without having to exert creative labor. Therefore, the present application is not limited to the embodiments herein, and any improvements and modifications made by those skilled in the art based on the disclosure of the present application without departing from the scope and spirit of the present application are within the scope of the present application.

Claims

1. A cap layer material, wherein, comprising a compound of Formula I and / or Formula II: In formula I: A1and A2are the same or different, independently a five-membered ring or a six-membered ring; when A1and A2are both five-membered rings, A is selected from a substituted or unsubstituted C6-C30 aryl group, a substituted or unsubstituted C3-C30 heteroaryl group, a substituted or unsubstituted C6-C24 aryl group derivative, a substituted or unsubstituted C3-C24 heteroaryl group derivative, a cyclobutyl group; Ak1and Ak2are the same or different, independently selected from a substituted or unsubstituted C1-C30 alkyl, a substituted or unsubstituted C1-C30 heteroalkyl, a substituted or unsubstituted C3-C30 cycloalkyl, a substituted or unsubstituted C2-C30 heterocycloalkyl, a substituted or unsubstituted C1-C30 alkylamine, a substituted or unsubstituted C1-C30 heteroalkylamine, a substituted or unsubstituted C3-C30 cycloalkylamine, a substituted or unsubstituted C2-C30 heterocycloalkylamine, a substituted or unsubstituted C3-C30 cycloalkylcarbonyl, or bonded to adjacent atoms to form a ring; when A1and A2are different or both six-membered rings, A is selected from a substituted or unsubstituted C6-C30 aryl group, a substituted or unsubstituted C3-C30 heteroaryl group; Ak1and Ak2are the same or different, independently selected from a substituted or unsubstituted C1-C30 alkyl, a substituted or unsubstituted C1-C30 heteroalkyl, a substituted or unsubstituted C3-C30 cycloalkyl, a substituted or unsubstituted C2-C30 heterocycloalkyl, a substituted or unsubstituted C1-C30 alkylamine, a substituted or unsubstituted C1-C30 heteroalkylamine, a substituted or unsubstituted C3-C30 cycloalkylamine, a substituted or unsubstituted C2-C30 heterocycloalkylamine, or bonded to adjacent atoms to form a ring; In formula II: A1and A2are the same or different, independently a five-membered ring or a six-membered ring; when A1and A2are both five-membered rings, A is selected from a substituted or unsubstituted C6-C30 aryl group, a substituted or unsubstituted C3-C30 heteroaryl group, a cyclobutyl group; Ar1and Ar2are the same or different, independently selected from a substituted or unsubstituted C6-C24 aryl, a substituted or unsubstituted C3-C24 heteroaryl; when A1and A2are different or both six-membered rings, A is selected from a substituted or unsubstituted C6-C30 aryl group, a substituted or unsubstituted C3-C30 heteroaryl group; Ar1and Ar2are the same or different, independently selected from a substituted or unsubstituted C6-C24 aryl, a substituted or unsubstituted C3-C24 heteroaryl; R is selected from hydrogen, or one or more substituents selected from deuterium, fluorine, chlorine, bromine, cyano, isonitrile, fluorine-containing groups, nitro, substituted or unsubstituted C1-C30 alkyl, substituted or unsubstituted C3-C30 cycloalkyl, substituted or unsubstituted C1-C30 heteroalkyl, substituted or unsubstituted C2-C30 heterocycloalkyl, substituted or unsubstituted C1-C30 alkylthio, substituted or unsubstituted C6-C30 aryl, substituted or unsubstituted C2-C30 heteroaryl, substituted or unsubstituted C1-C30 ketone, substituted or unsubstituted C2-C30 alkoxycarbonyl, substituted or unsubstituted C6-C30 aryloxycarbonyl, silyl, arylsilyl, ester phosphine oxide, sulfone, azaheteroaryl, carboxyl, ether groups; Any hydrogen atom on Formula I and / or Formula II is optionally substituted with deuterium.

2. The coverstock material of claim 1, wherein, The compound of Formula I is selected from: The compound of Formula II is selected from: A is selected from substituted or unsubstituted C6-C30 aryl groups, substituted or unsubstituted C3-C30 heteroaryl groups; R is selected from hydrogen, deuterium, substituted or unsubstituted C1-C30 alkyl, substituted or unsubstituted C3-C30 cycloalkyl, substituted or unsubstituted C1-C30 heteroalkyl, substituted or unsubstituted C2-C30 heterocycloalkyl, substituted or unsubstituted C1-C10 fluoroalkyl, substituted or unsubstituted C1-C10 fluorocycloalkyl, substituted or unsubstituted C6-C30 aryl, substituted or unsubstituted C3-C30 heteroaryl; Ak1and Ak2are the same or different, independently selected from substituted or unsubstituted C1-C30 alkyl, substituted or unsubstituted C1-C30 heteroalkyl, substituted or unsubstituted C3-C30 cycloalkyl, substituted or unsubstituted C2-C30 heterocycloalkyl, substituted or unsubstituted C1-C30 alkylamine, substituted or unsubstituted C1-C30 heteroalkylamine, substituted or unsubstituted C3-C30 cycloalkylamine, substituted or unsubstituted C2-C30 heterocycloalkylamine, or bonded to adjacent atoms to form a ring; Ar1and Ar2are the same or different, independently selected from substituted or unsubstituted C6-C24 aryl, substituted or unsubstituted C3-C24 heteroaryl.

3. The coverstock material of claim 2, wherein, In the case where at least one of A, R, Ak1, Ak2, Ar1and Ar2is substituted, the substituents are independently selected from the group of one or more of fluorine atom, trifluoromethyl, cyano, nitro, phosphine oxide, sulfone, sulfoxide, aryl, azaheteroaryl, dimethyl, tert-butyl, isopropyl, carboxyl derivative groups.

4. The coverstock material of claim 3, wherein, A is selected from the following groups, which are substituted or unsubstituted:

5. The coverstock material of claim 3, wherein, Ar1and Ar2are independently selected from the following groups, which are substituted or unsubstituted: wherein * represents the site of attachment; Me represents a methyl group.

6. The coverstock material of claim 3, wherein, Ak1and Ak2are independently selected from the group consisting of methyl, ethyl, propyl, isopropyl, butyl, t-butyl, sec-butyl, pentyl, isopentyl, hexyl, cyclohexyl, adamantyl, the following groups, which are substituted or unsubstituted: wherein * represents the site of attachment; (C)n represents an alkyl group having n carbon atoms, and n is selected from an integer from 1 to 6; Ar3is selected from substituted or unsubstituted C6-C12 aryl, substituted or unsubstituted C3-C12 heteroaryl.

7. The coverstock material of claim 3, wherein, The compound of Formula I is selected from the group consisting of: wherein Ad represents an adamantyl group; Ak2 is selected from the following groups: adamantyl, wherein * represents the site of attachment; The compound of Formula II is selected from the group consisting of: wherein Me represents a methyl group; Ar2is selected from the following groups: wherein * represents the site of attachment.

8. The coverstock material of claim 7, wherein, The compound of Formula II is selected from the group consisting of: The compound of Formula I is selected from the group consisting of:

9. The coverstock material of claim 1, wherein, A1and A2are both five-membered rings, A is a cyclobutyl group, and R is hydrogen; the compound of formula I is selected from: the compound of formula II is selected from: In said formula I, Ak1 and Ak2 are the same or different and are independently selected from the group consisting of substituted or unsubstituted C1-C30 alkyl, substituted or unsubstituted C1-C30 heteroalkyl, substituted or unsubstituted C3-C30 cycloalkyl, substituted or unsubstituted C2-C30 heterocycloalkyl, substituted or unsubstituted C3-C30 cycloalkylcarbonyl, substituted or unsubstituted C1-C30 alkylamino, substituted or unsubstituted C1-C30 heteroalkylamino, substituted or unsubstituted C3-C30 cycloalkylamino, substituted or unsubstituted C2-C30 heterocycloalkylamino, or bonded to the adjacent atoms to form a ring; In said formula II, Ar1 and Ar2 are the same or different and are independently selected from the group consisting of substituted or unsubstituted C6-C24 aryl, substituted or unsubstituted C3-C24 heteroaryl.

10. The coverstock material of claim 9, wherein, Said Ar1 and Ar2 are independently selected from the group consisting of substituted or unsubstituted phenyl, biphenyl, naphthyl, phenanthryl, anthryl, 9,9'-dimethylfluorenyl, 9,9'-diphenylfluorenyl, dibenzofuranyl, dibenzothiophenyl, carbazolyl, spirofluorenyl, spirofluorenoxanthryl, triphenylenyl, triazinyl, phosphine oxide derivative group, sulfone derivative group, N-phenylphthalimide group, benzophenone group; preferably, when substituted, the substituents are selected from the group consisting of fluorine atom, fluorine-containing group, alkyl, heteroalkyl, alkenyl, hydroxyl, phenyl, naphthyl, pyridyl, phenol group substituted or unsubstituted with fluorine atom or fluorine-containing group or alkyl or heteroalkyl or alkenyl.

11. The coverstock material of claim 9, wherein, Said Ak1 and Ak2 are independently selected from the group consisting of substituted or unsubstituted C1-C20 alkyl, C5-C12 cycloalkyl, C5-C12 cycloalkylcarbonyl, C5-C18 cycloalkylamino; preferably, when substituted, the substituents are independently selected from the group consisting of fluorine atom, fluorine-containing group, hydroxyl, C1-C6 alkyl, C6-C12 aryl, C3-C12 heteroaryl substituted or unsubstituted with fluorine atom or fluorine-containing group or hydroxyl; More preferably, said Ak1 and Ak2 are independently selected from the following groups, substituted or not by a fluorine atom or a fluorine-containing group or a hydroxyl group: methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, t-butyl, s-butyl, n-pentyl, i-pentyl, n-hexyl, i-hexyl, dodecyl, octadecyl, *-(C)n-Ar3, cyclopentyl, cyclohexyl, adamantyl, wherein * represents the connection site; (C)n represents an alkyl group having n carbon atoms, and n is selected from an integer from 1 to 6; Ar3 is selected from substituted or unsubstituted C6-C12 aryl, substituted or unsubstituted C3-C12 heteroaryl, and when substituted, the substituents are selected from C6-C12 aryl, C3-C12 heteroaryl; More preferably, Ak1 and Ak2 are independently selected from dodecyl, octadecyl, pentanol, cyclopentyl, cyclohexyl, ... adamantyl, * represents the connection site.

12. The coverstock material of claim 9, wherein, The compound of Formula I is selected from the group consisting of: wherein Ad represents an adamantyl group; C 12 H 25 represents a dodecyl group, C 18 H 37 represents an octadecyl group; Ak2 is selected from the following groups: adamantyl, dodecyl, octadecyl, pentanol group, wherein * represents the connection site; preferably, Ak1 and Ak2 are the same; The compound of Formula II is selected from the group consisting of: wherein Ar2 is selected from the group consisting of phenyl, naphthyl, phenanthryl, dibenzofuranyl, 9,9'-dimethylfluorenyl, carbazolyl, spirofluorenyl, spirofluorenoxanthryl, phenyl-substituted triazinyl, phosphine oxide derivative group, sulfone derivative group, pyridyl-substituted phenyl, naphthyl-substituted phenyl, 9,9'-diphenylfluorenyl, N-phenylphthalimide group, benzophenone group, hydroxyl-substituted biphenyl, phenyl-substituted anthryl; preferably, Ar2 and Ar1 are the same.

13. The coverstock material of claim 12, wherein, The cover layer material comprises one or more of the following compounds:

14. The coverstock material of claim 1, wherein, In the formula I, A1and A2are both five-membered rings; the compound shown in the formula I is selected from: wherein: A is selected from substituted or unsubstituted C6-C24 aryl group or a derivative group thereof, substituted or unsubstituted C3-C24 heteroaryl group or a derivative group thereof; Ak1and Ak2are the same or different and are independently selected from the group consisting of substituted or unsubstituted C1-C30 alkyl, substituted or unsubstituted C1-C30 oxaalkyl, substituted or unsubstituted C1-C30 thiaalkyl, substituted or unsubstituted C1-C30azaalkyl, substituted or unsubstituted C1-C30 phosphooxaalkyl, substituted or unsubstituted C1-C30 thiophosphooxaalkyl, substituted or unsubstituted C1-C30 sulfoxoalkyl; R is selected from the group consisting of hydrogen, deuterium, fluorine, fluorine-containing groups, substituted or unsubstituted C1-C30 alkyl, substituted or unsubstituted C3-C30 cycloalkyl, substituted or unsubstituted C1-C30 heteroalkyl, substituted or unsubstituted C2-C30 heterocycloalkyl, substituted or unsubstituted C6-C30 aryl, substituted or unsubstituted C3-C30 heteroaryl.

15. The coverstock material of claim 14, wherein, The compound of Formula I has at least one of the following characteristics (1) to (4): (1) A is selected from the group consisting of substituted or unsubstituted C6-C18 aryl groups or their derived groups; (2) Ak1and Ak2are the same or different and are independently selected from the group consisting of substituted or unsubstituted C1-C20 alkyl, substituted or unsubstituted C1-C20 oxaalkyl, substituted or unsubstituted C1-C20 azaalkyl; (3) R is selected from the group consisting of hydrogen, deuterium, fluorine, substituted or unsubstituted C1-C20 fluoroalkyl, substituted or unsubstituted C1-C20 alkyl; (4) A, Ak1, Ak2and R are each independently in an unsubstituted or substituted condition; if in a substituted condition, the substituents are independently selected from the group consisting of deuterium, fluorine, fluorine-containing groups, C1-C10 alkyl, cyano, nitro, hydroxyl, phosphoroxy, sulfoxide, azaheteroaryl, carboxy derivative groups.

16. The coverstock material of claim 15, wherein, The compound of Formula I has at least one of the following characteristics 1) to 4): 1) A is selected from the group consisting of substituted or unsubstituted C6-C12 aryl groups, substituted or unsubstituted C6-C12 ether aryl derived groups, substituted or unsubstituted C6-C12 sulfone aryl derived groups, substituted or unsubstituted C6-C18 phosphoroxy aryl derived groups; 2) Ak1and Ak2are the same or different and are independently selected from the group consisting of substituted or unsubstituted C1-C18 alkyl, substituted or unsubstituted C1-C18 oxaalkyl, substituted or unsubstituted C1-C18 azaalkyl; 3) R is selected from the group consisting of hydrogen, deuterium, fluorine, substituted or unsubstituted C1-C10 fluoroalkyl, substituted or unsubstituted C1-C10 alkyl; 4) A, Ak1, Ak2and R are each independently in an unsubstituted or substituted condition; if in a substituted condition, the substituents are independently selected from the group consisting of deuterium, fluorine, C1-C10 fluoroalkyl, C1-C10 alkyl, cyano, nitro, hydroxyl, phosphoroxy, sulfoxide, C3-C12 azaheteroaryl, carboxy derivative groups.

17. The coverstock material of claim 16, wherein, The compound of Formula I has at least one of the following characteristics i) to iv): i) A is selected from the following groups, which are substituted or unsubstituted: wherein (*)4represents four linking sites consisting of two pairs of optionally positioned adjacent linking sites; ii) Ak1and Ak2are the same or different, independently selected from substituted or unsubstituted C3-C18alkyl, substituted or unsubstituted C1-C10oxaalkyl, substituted or unsubstituted C1-C10azaalkyl; iii) R is selected from hydrogen, deuterium, fluorine, C1-C10fluoroalkyl; iv) A, Ak1, Ak2and R are each independently unsubstituted or substituted; if substituted, the substituents are independently selected from deuterium, fluorine, C1-C10fluoroalkyl, C1-C10alkyl, hydroxyl.

18. The coverstock material of claim 17, wherein, wherein feature ii) is further defined as Ak1and Ak2are the same or different, independently selected from substituted or unsubstituted C3-C18alkyl, substituted or unsubstituted 6-(pentyloxy)hexyl, substituted or unsubstituted N,N-dimethylhexylamino; and further defined as Ak1and Ak2are the same or different, independently selected from substituted or unsubstituted propyl, substituted or unsubstituted butyl, substituted or unsubstituted pentyl, substituted or unsubstituted hexyl, substituted or unsubstituted heptyl, substituted or unsubstituted dodecyl, substituted or unsubstituted octadecyl, substituted or unsubstituted 6-(pentyloxy)hexyl, substituted or unsubstituted N,N-dimethylhexylamino.

19. The coverstock material of claim 18, wherein, The compound of Formula I is selected from the group consisting of: wherein C 18 H 37 represents octadecyl, C6H 13 represents hexadecyl; Ak2is selected from octadecyl, hexadecyl, 6-(pentyloxy)hexyl, N,N-dimethylhexylamino, n-dodecyl, monofluorinated n-dodecyl, t-butyl, n-butyl, n-heptyl, t-butylethyl, n-pentyl, 6-hydroxyhexyl, n-hexyl, 1-ethylbutyl, 2,3-dihydroxypropyl, propyl.

20. The coverstock material of claim 19, wherein, The compound of Formula I is selected from the group consisting of:

21. A compound which is a compound of Formula I and / or Formula II: In formula I: A1and A2are the same or different, independently a five-membered ring or a six-membered ring; when A1and A2are both five-membered rings, A is selected from substituted or unsubstituted C6-C30aryl groups, substituted or unsubstituted C3-C30heteroaryl groups, substituted or unsubstituted C6-C24aryl groups derived groups, substituted or unsubstituted C3-C24heteroaryl groups derived groups, cyclobutyl groups; Ak1and Ak2are the same or different, independently selected from substituted or unsubstituted C1-C30alkyl, substituted or unsubstituted C1-C30heteroalkyl, substituted or unsubstituted C3-C30cycloalkyl, substituted or unsubstituted C2-C30heterocycloalkyl, substituted or unsubstituted C1-C30alkylamino, substituted or unsubstituted C1-C30heteroalkylamino, substituted or unsubstituted C3-C30cycloalkylamino, substituted or unsubstituted C2-C30heterocycloalkylamino, substituted or unsubstituted C3-C30cycloalkylcarbonyl, or bonded to adjacent atoms to form a ring; when A1and A2are different or both six-membered rings, A is selected from substituted or unsubstituted C6-C30aryl groups, substituted or unsubstituted C3-C30heteroaryl groups; Ak1and Ak2are the same or different, independently selected from substituted or unsubstituted C1-C30alkyl, substituted or unsubstituted C1-C30heteroalkyl, substituted or unsubstituted C3-C30cycloalkyl, substituted or unsubstituted C2-C30heterocycloalkyl, substituted or unsubstituted C1-C30alkylamino, substituted or unsubstituted C1-C30heteroalkylamino, substituted or unsubstituted C3-C30cycloalkylamino, substituted or unsubstituted C2-C30heterocycloalkylamino, or bonded to adjacent atoms to form a ring; In formula II: A1and A2are the same or different and independently a five-membered ring or a six-membered ring; when A1and A2are both five-membered rings, A is selected from a substituted or unsubstituted C6-C30 aryl group, a substituted or unsubstituted C3-C30 heteroaryl group, a cyclobutyl group; Ar1and Ar2are the same or different and independently selected from a substituted or unsubstituted C6-C24 aryl group, a substituted or unsubstituted C3-C24 heteroaryl group; when A1and A2are different or both six-membered rings, A is selected from a substituted or unsubstituted C6-C30 aryl group, a substituted or unsubstituted C3-C30 heteroaryl group; Ar1and Ar2are the same or different and independently selected from a substituted or unsubstituted C6-C24 aryl group, a substituted or unsubstituted C3-C24 heteroaryl group; In formula I and formula II, R is selected from hydrogen, or one or more substituents: deuterium, fluorine, chlorine, bromine, cyano, isonitrile, fluorine-containing group, nitro, substituted or unsubstituted C1-C30 alkyl, substituted or unsubstituted C3-C30 cycloalkyl, substituted or unsubstituted C1-C30 heteroalkyl, substituted or unsubstituted C2-C30 heterocycloalkyl, substituted or unsubstituted C1-C30 alkylthio, substituted or unsubstituted C6-C30 aryl, substituted or unsubstituted C2-C30 heteroaryl, substituted or unsubstituted C1-C30 ketone, substituted or unsubstituted C2-C30 alkoxycarbonyl, substituted or unsubstituted C6-C30 aryloxycarbonyl, silyl, arylsilyl, ester phosphine oxide, sulfone, nitrogen heteroaryl, carboxyl, ether group; Any hydrogen atom on formula I and / or formula II is optionally substituted with deuterium.

22. An organic light emitting device, wherein, A structure comprising a first electrode, an organic layer, a second electrode and a capping layer structure stacked in this order, and the capping layer structure comprises a capping layer material according to any one of claims 1 to 20 or a compound according to claim 21.

23. The organic light emitting device of claim 22, wherein, The capping layer structure comprises a low refractive index capping layer and a high refractive index capping layer on the low refractive index capping layer; wherein the low refractive index capping layer comprises a capping layer material according to any one of claims 1 to 20 or a compound according to claim 21, and the high refractive index capping layer has a refractive index of 1.90 or more for light of 460 nm wavelength; preferably, the high refractive index capping layer has a refractive index of 1.90 to 2.50 for light of 460 nm wavelength.

24. The organic light emitting device of claim 23, wherein, The high refractive index capping layer comprises one or more of an inorganic compound and an organic compound, the inorganic compound comprising at least one of SiOx, SiNy, ZnS, ZnSe, ZrO, TiO2, and x and y are independently selected from an integer from 1 to 4; the organic compound comprising one or more of an arylamine derivative, a carbazole derivative, a benzimidazole derivative, a triazole derivative; preferably, the organic compound comprises at least one of the following compounds:

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