Ink, electroluminescent device, preparation method of electroluminescent device and display device

Abstract

The invention relates to ink, an electroluminescent device, a preparation method of the electroluminescent device and a display device. The ink comprises a first component and a second component, the first component is a polymer, the structural formula of the second component is # imgabs0, X comprises one or a combination of more of aryl with the ring atom number of 5-60 and heteroaryl with the ring atom number of 5-60, the aryl is not substituted or substituted by amino, hydroxyl, carboxyl, nitryl, sulfonic acid group, aldehyde group, sulfydryl and cyano group, and the heteroaryl is one or a combination of more of aryl with the ring atom number of 5-60 and heteroaryl with the ring atom number of 5-60. Wherein heteroatoms in the heteroaryl are one or more of N, S, O, P and Si, and the number of the heteroatoms is 1-20; y is a halogen-containing group, the ratio of m to n is (2-20): 1, and both m and n are positive integers. The ink can be used for preparing a hole transport layer through a solution method, so that the interface mutual solubility between a light-emitting layer and the hole transport layer is reduced, the efficiency of an electroluminescent device is improved, and the service life of the electroluminescent device is prolonged.

Description

Technical Field

[0001] The present invention relates to the field of electroluminescent devices, and in particular to an ink, an electroluminescent device and a preparation method thereof, and a display device. Background Art

[0002] Organic electroluminescent devices (OLEDs) prepared by the solution method have low manufacturing costs, and therefore have outstanding cost advantages in large-area and rich-form terminal display screens. However, the efficiency and life of OLED devices prepared by the current solution method are somewhat different from those prepared by the evaporation method. The main reason is that the interface between the light-emitting layer (EML) and the hole transport layer (HTL) prepared by the solution method has different degrees of interfacial solubility. Summary of the invention

[0003] Based on this, some embodiments of the present invention provide an ink that can prepare a hole transport layer by a solution method to reduce the interfacial miscibility between the light-emitting layer and the hole transport layer, thereby improving the efficiency and life of the electroluminescent device.

[0004] Other embodiments of the present invention further provide an electroluminescent device, a method for preparing the same, and a display device.

[0005] An ink includes: a first component and a second component, wherein the first component is a polymer, and the second component has the following structural formula:

[0006]

[0007] Wherein, X includes one or more combinations of aryl groups with 5 to 60 ring atoms and heteroaryl groups with 5 to 60 ring atoms which are unsubstituted or substituted with amino, hydroxyl, carboxyl, nitro, sulfonic acid, aldehyde, thiol, and cyano groups, wherein the heteroatom in the heteroaryl group is one or more of N, S, O, P, and Si, and the number of heteroatoms is 1 to 20;

[0008] Y is a group containing halogen; m:n is (2-20):1, and m, n are both positive integers;

[0009] R1 and R2 are each independently selected from hydrogen, deuterium, amino, halogen, hydroxyl, carboxyl, nitro, sulfonic acid, aldehyde, mercapto, cyano, ether alkyl, carbonyl alkyl; C1-C2 alkyl unsubstituted or substituted by amino, halogen, hydroxyl, carboxyl, nitro, sulfonic acid, aldehyde, mercapto, cyano 20 Chain hydrocarbon group, C1~C 20The invention further comprises a chain hydrocarbonoxy group having 3 to 60 ring atoms, a cycloalkyl group having 3 to 60 ring atoms, a heterocycloalkyl group having 3 to 60 ring atoms, an aryl group having 5 to 60 ring atoms, a heteroaryl group having 5 to 60 ring atoms, an aryloxy group having 5 to 60 ring atoms, and a heteroaryloxy group having 5 to 60 ring atoms, wherein the heteroatom in the heteroaryl group or the heteroaryloxy group is one or more of N, S, O, P and Si, and the number of heteroatoms is 1 to 20.

[0010] In some embodiments, the structural formula of Y is as follows: wherein L1 and L2 are each independently a single bond, -O-, -S-, -CO-, -CO-O-, -O-CO-, -O-CO-O-, -CH=N-, -N=CH-, -N=N or a C1-C6 alkylene group, and a is 1-6;

[0011] R3 to R7 are each independently selected from hydrogen, deuterium, amino, halogen, hydroxyl, carboxyl, nitro, sulfonic acid, aldehyde, mercapto, cyano, ether alkyl, carbonyl alkyl; C1 to C2 alkyl unsubstituted or substituted by amino, halogen, hydroxyl, carboxyl, nitro, sulfonic acid, aldehyde, mercapto, cyano 20 Chain hydrocarbon group, C1~C 20 The invention further comprises a chain hydrocarbonoxy group having 3 to 60 ring atoms, a cycloalkyl group having 3 to 60 ring atoms, a heterocycloalkyl group having 3 to 60 ring atoms, an aryl group having 5 to 60 ring atoms, a heteroaryl group having 5 to 60 ring atoms, an aryloxy group having 5 to 60 ring atoms, and a heteroaryloxy group having 5 to 60 ring atoms, wherein the heteroatom in the heteroaryl group or the heteroaryloxy group is one or more of N, S, O, P and Si, and the number of heteroatoms is 1 to 20; and at least one of R3 to R7 is fluorine.

[0012] In some embodiments, Y is selected from one of the following structures:

[0013]

[0014] In some embodiments, X includes one or more of a carbazole group and a triarylamine group.

[0015] In some embodiments, X is selected from one of the following structures:

[0016] and

[0017] In some embodiments, the second component satisfies one or more of the following conditions (1) to (5):

[0018] (1) m is 5 to 100, n is 1 to 10;

[0019] (2) m:n is (3-5):1;

[0020] (3) The mass ratio of the first component to the second component is (2.5-10):1.

[0021] (4) R1 is

[0022] (5) R2 is hydrogen or

[0023] In some embodiments, the first component includes polyvinyl carbazole, poly[(9,9-dioctylfluorenyl-2,7-diyl)-co-(4,4'-(N-(4-sec-butylphenyl)diphenylamine)]), poly[N,N'-bis(4-butylphenyl)-N,N'-bisphenylbenzidine], poly[(9,9-dioctylfluorenyl-2,7-diyl)-co-(4,4'-(N-(4-sec-butylphenyl)diphenylamine)], poly[N,N'-bis(4-butylphenyl)-N,N'-bisphenylbenzidine], poly[(9,9-dioctylfluorenyl-2,7-diyl)-co-(N,N'-bis{4-butylphenyl}-benzidine-N,N'-{1,4-diphenyl})], and One or more of the .

[0024] In some embodiments, the mass ratio of the first component to the second component is (1-20):1; and / or,

[0025] The surface energy of the first component is greater than the surface energy of the second component.

[0026] In some embodiments, the ink further includes a solvent, and the solvent includes one or more of xylene, chlorobenzene, tetralin, cyclohexylbenzene, anisole, p-methylanisole, cyclohexanone and decalin.

[0027] A method for preparing an electroluminescent device comprises the following steps:

[0028] Forming an ink film on the surface of the anode to prepare a hole transport layer, wherein the ink is as described above;

[0029] A light-emitting layer and a cathode are formed on the surface of the hole transport layer to prepare an electroluminescent device.

[0030] In some embodiments, the step of forming a film of ink on the surface of the anode includes: applying the ink to the surface of the anode, and then performing post-treatment to form the ink into a film, and the post-treatment includes one or more of vacuum drying and annealing treatment, wherein the vacuum drying step is performed at a temperature of 0°C to 150°C, and the annealing step is performed under an inert atmosphere at a temperature of 100°C to 300°C.

[0031] An electroluminescent device comprises an anode, a hole transport layer, a light-emitting layer and a cathode which are stacked in sequence;

[0032] The hole transport layer includes a first sublayer and a second sublayer stacked in layers, wherein the first sublayer is closer to the anode than the second sublayer; the material of the first sublayer includes a polymer, and the material of the second sublayer includes a compound having the following structural formula:

[0033]

[0034] Wherein, X includes one or more combinations of aryl groups with 5 to 60 ring atoms and heteroaryl groups with 5 to 60 ring atoms which are unsubstituted or substituted with amino, hydroxyl, carboxyl, nitro, sulfonic acid, aldehyde, thiol, and cyano groups, wherein the heteroatom in the heteroaryl group is one or more of N, S, O, P, and Si, and the number of heteroatoms is 1 to 20;

[0035] Y is a group containing halogen; m:n is (2-20):1, and m, n are both positive integers;

[0036] R1 and R2 are each independently selected from hydrogen, deuterium, amino, halogen, hydroxyl, carboxyl, nitro, sulfonic acid, aldehyde, mercapto, cyano, ether alkyl, carbonyl alkyl; C1-C2 alkyl unsubstituted or substituted by amino, halogen, hydroxyl, carboxyl, nitro, sulfonic acid, aldehyde, mercapto, cyano 20 Chain hydrocarbon group, C1~C 20 The invention further comprises a chain hydrocarbonoxy group having 3 to 60 ring atoms, a cycloalkyl group having 3 to 60 ring atoms, a heterocycloalkyl group having 3 to 60 ring atoms, an aryl group having 5 to 60 ring atoms, a heteroaryl group having 5 to 60 ring atoms, an aryloxy group having 5 to 60 ring atoms, and a heteroaryloxy group having 5 to 60 ring atoms, wherein the heteroatom in the heteroaryl group or the heteroaryloxy group is one or more of N, S, O, P and Si, and the number of heteroatoms is 1 to 20.

[0037] In some embodiments, the thickness ratio of the first sublayer to the second sublayer is (1-20):1.

[0038] In some embodiments, the electroluminescent device includes a cathode, an electron injection layer, an electron transport layer, a light-emitting layer, a hole transport layer, a hole injection layer and an anode which are stacked in sequence.

[0039] In some embodiments, the electroluminescent device satisfies one or more of the following conditions (1) to (4):

[0040] (1) The material of the anode and / or the cathode includes one or more of metal, carbon material and metal oxide, wherein the metal includes one or more of Al, Ag, Cu, Mo, Au, Ba, Ca, Yb and Mg; the carbon material includes one or more of graphite, carbon nanotubes, graphene and carbon fiber; the metal oxide includes doped or undoped metal oxide, including one or more of ITO, FTO, ATO, AZO, GZO, IZO, MZO and AMO, or includes a composite electrode in which a metal is sandwiched between doped or undoped transparent metal oxides, wherein the composite electrode includes one or more of AZO / Ag / AZO, AZO / Al / AZO, ITO / Ag / ITO, ITO / Al / ITO, ZnO / Ag / ZnO, ZnO / Al / ZnO, ZnS / Ag / ZnS, ZnS / Al / ZnS, TiO2 / Ag / TiO2 and TiO2 / Al / TiO2;

[0041] (2) The light-emitting layer is a quantum dot light-emitting layer or an organic light-emitting layer;

[0042] The material of the quantum dot light-emitting layer includes at least one of a single structure quantum dot and a core-shell structure quantum dot, and the material of the single structure quantum dot is selected from at least one of a II-VI group compound, a IV-VI group compound, a III-V group compound and a I-III-VI group compound, wherein the II-VI group compound is selected from CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, ZnO, HgS, HgSe, HgTe, CdSeS, CdSeTe, CdSTe, ZnSeS, ZnSeTe, ZnSTe, Hg At least one of CdZnS, CdZnSe, CdZnTe, CdHgS, CdHgSe, CdHgTe, HgZnS, HgZnSe, HgZnTe, CdZnSeS, CdZnSeTe, CdZnSTe, CdHgSeS, CdHgSeTe, CdHgSTe, HgZnSeS, HgZnSeTe and HgZnSTe, wherein the Group IV-VI compound is selected from SnS, SnSe, SnTe, PbS, PbSe, PbTe, SnSe At least one of SnS, SnSeTe, SnSTe, PbSeS, PbSeTe, PbSTe, SnPbS, SnPbSe, SnPbTe, SnPbSSe, SnPbSeTe and SnPbSTe, and the III-V group compound is selected from GaN, GaP, GaAs, GaSb, AlN, AlP, AlAs, AlSb, InN, InP, InAs, InSb, GaNP, GaNAs, GaNSb, GaPAs, GaPSb, AlNP, AlNAs, AlNSb, AlPAs , at least one of AlPSb, InNP, InNAs, InNSb, InPAs, InPSb, GaAlNP, GaAlNAs, GaAlNSb, GaAlPAs, GaAlPSb, GaInNP, GaInNAs, GaInNSb, GaInPAs, GaInPSb, InAlNP, InAlNAs, InAlNSb, InAlPAs or InAlPSb, and the I-III-VI group compound is selected from at least one of CuInS2, CuInSe2 and AgInS2;

[0043] The core of the quantum dot with a core-shell structure includes any one of the quantum dots with a single structure, and the shell material of the quantum dot with a core-shell structure includes at least one of CdS, CdTe, CdSeTe, CdZnSe, CdZnS, CdSeS, ZnSe, ZnSeS, ZnS and the quantum dots with a single structure;

[0044] The material of the organic light-emitting layer includes at least one of 4,4'-bis(N-carbazole)-1,1'-biphenyl:tris[2-(p-tolyl)pyridine-C2,N)iridium(III), 4,4',4"-tris(carbazole-9-yl)triphenylamine:tris[2-(p-tolyl)pyridine-C2,N)iridium, diarylanthracene derivatives, distilbene aromatic derivatives, pyrene derivatives, fluorene derivatives, TBPe fluorescent materials, TTPX fluorescent materials, TBRb fluorescent materials and DBP fluorescent materials, polyacetylene and its derivatives, polyparaphenylene and its derivatives, polythiophene and its derivatives, polyfluorene and its derivatives;

[0045] (3) The material of the hole injection layer includes at least one of TFB, CuPc, PVK, Poly-TPD, DNTPD, TCATA, TCCA, CBP, TPD, NPB, NPD, PEDOT:PSS, TAPC, MCC, F4-TCNQ, HATCN, 4,4',4'-tris(N-3-methylphenyl-N-phenylamino)triphenylamine, polyaniline, transition metal oxide, transition metal sulfide, transition metal tinide, doped graphene, undoped graphene and C60;

[0046] (4) The material of the electron transport layer and / or the electron injection layer includes inorganic materials and / or organic materials, wherein the inorganic material is selected from one or more of doped or undoped zinc oxide, barium oxide, aluminum oxide, nickel oxide, titanium oxide, tin oxide, tantalum oxide, zirconium oxide, nickel oxide, lithium titanium oxide, zinc aluminum oxide, zinc manganese oxide, zinc tin oxide, lithium zinc oxide, indium tin oxide, cadmium sulfide, zinc sulfide, molybdenum sulfide, tungsten sulfide, copper sulfide, zinc tin, indium phosphide, gallium phosphide, copper indium sulfide, copper gallium sulfide, and barium titanate, and the doped elements include one or more of aluminum, magnesium, lithium, manganese, yttrium, lanthanum, copper, nickel, zirconium, cerium, and gadolinium; and the organic material is selected from one or more of quinoxaline compounds, imidazole compounds, triazine compounds, fluorene-containing compounds, and hydroxyquinoline compounds.

[0047] A display device comprises the electroluminescent device mentioned above or the electroluminescent device prepared by the above preparation method.

[0048] The ink includes a first component and a second component, and can be formed into a film by a solution method. When the solution method is used for film formation, since the second component contains a certain amount of halogen groups, the second component has a lower surface energy relative to the first component. During the solvent drying process, the difference in surface energy between the first component and the second component is large, so that the formed film undergoes vertical phase separation, and the lower layer is mainly composed of the first component, and the upper layer is mainly composed of the second component. By adjusting the proportion of halogen-containing groups in the second component within the above range, the second component can be vertically phase-separated from the first component while the subsequent light-emitting layer can be formed into a film. Therefore, within the above ratio range, the surface energy of the film mainly formed by the second component in the upper layer is low, and the wettability to the solvent is poor, which can block the penetration of the solvent when the light-emitting layer is formed, thereby reducing the damage to the hole transport layer during EML film formation, reducing interface mutual solubility, and improving the efficiency and life of the prepared OLED device. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0050] Figure 1 This is a schematic diagram of the structure of an electroluminescent device in some embodiments of the present invention.

[0051] Figure numerals: electroluminescent device 100, anode 110, hole injection layer 120, hole transport layer 130, first sublayer 132, second sublayer 134, electron blocking layer 140, light-emitting layer 150, hole blocking layer 160, electron transport layer 170, electron injection layer 180, cathode 190. DETAILED DESCRIPTION

[0052] In order to facilitate the understanding of the present invention, the present invention will be described more comprehensively below in conjunction with the specific embodiments. Preferred embodiments of the present invention are provided in the specific embodiments. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the understanding of the disclosure of the present invention more thorough and comprehensive.

[0053] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more related listed items.

[0054] Unless otherwise specified or there is a contradiction, the terms or phrases used in this invention have the following meanings:

[0055] In the present invention, "first" and "second" are used only for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features.

[0056] In the description of the present invention, “plurality” means at least two, for example, two, three, etc., unless otherwise clearly and specifically defined.

[0057] In the present invention, "one or several" refers to any one, any two or any two or more of the listed items. Among them, "several" refers to any two or any two or more.

[0058] In the present invention, the percentage concentration involved, unless otherwise specified, refers to the final concentration. The final concentration refers to the proportion of the added component in the system after the addition of the component.

[0059] The words "preferably", "more preferably", etc. in the present invention refer to embodiments of the present invention that may provide certain beneficial effects in certain circumstances. However, other embodiments may also be preferred under the same circumstances or other circumstances. In addition, the description of one or more preferred embodiments does not imply that other embodiments are not applicable, nor is it intended to exclude other embodiments from the scope of the present invention.

[0060] When a numerical range is disclosed in the present invention, the above range is considered to be continuous and includes the minimum and maximum values ​​of the range, as well as every value between such minimum and maximum values. Further, when a range refers to an integer, every integer between the minimum and maximum values ​​of the range is included. In addition, when multiple ranges are provided to describe features or characteristics, the ranges can be merged. In other words, unless otherwise indicated, all ranges disclosed in the present invention should be understood to include any and all subranges included therein.

[0061] In the present invention, the technical features described in an open manner include closed technical solutions composed of the listed features, and also include open technical solutions containing the listed features.

[0062] The terms "including" and "having" and any variations thereof in the embodiments of the present invention are intended to cover non-exclusive inclusions. For example, a process, method, system, product, or device that includes a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units that are not listed, or may optionally include other steps or components that are inherent to these processes, methods, products, or devices.

[0063] Reference to "embodiments" in the present invention means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described in the present invention may be combined with other embodiments.

[0064] The term "alkyl" refers to a saturated hydrocarbon containing a primary (normal) carbon atom, or a secondary carbon atom, or a tertiary carbon atom, or a quaternary carbon atom, or a combination thereof. Phrases containing this term, for example, "C1-C6 alkyl" refers to an alkyl group containing 1 to 6 carbon atoms, each occurrence of which can be independently C1 alkyl, C2 alkyl, C3 alkyl, C4 alkyl, C5 alkyl or C6 alkyl. Suitable examples include, but are not limited to, methyl (Me, -CH3), ethyl (Et, -CH2CH3), 1-propyl (n-Pr, n-propyl, -CH2CH2CH3), 2-propyl (i-Pr, i-propyl, -CH(CH3)2), 1-butyl (n-Bu, n-butyl, -CH2CH2CH2CH3), 2-methyl-1-propyl (i-Bu, i-butyl, -CH2CH(CH3)2), 2-butyl (s-Bu, s-butyl, -C H(CH3)CH2CH3), 2-methyl-2-propyl (t-Bu, t-butyl, -C(CH3)3), 1-pentyl (n-pentyl, -CH2CH2CH2CH2CH3), 2-pentyl (-CH(CH3)CH2CH2CH3), 3-pentyl (-CH(CH2CH3)2), 2-methyl-2-butyl (-C(CH3)2CH2CH3), 3-methyl-2-butyl (-CH(CH3)CH(CH3)2), 3-methyl -1-butyl (-CH2CH2CH(CH3)2), 2-methyl-1-butyl (-CH2CH(CH3)CH2CH3), 1-hexyl (-CH2CH2CH2CH2CH2CH3), 2-hexyl (-CH(CH3)CH2CH2CH2CH3), 3-hexyl (-CH(CH2CH3)(CH2CH2CH3)), 2-methyl-2-pentyl (-C(CH3)2CH2CH2CH3), 3-methyl-2-pentyl ( -CH(CH3)CH(CH3)CH2CH3), 4-methyl-2-pentyl (-CH(CH3)CH2CH(CH3)2), 3-methyl-3-pentyl (-C(CH3)(CH2CH3)2), 2-methyl-3-pentyl (-CH(CH2CH3)CH(CH3)2), 2,3-dimethyl-2-butyl (-C(CH3)2CH(CH3)2), 3,3-dimethyl-2-butyl (-CH(CH3)C(CH3)3, etc.

[0065] "Aryl" refers to an aromatic hydrocarbon group derived from an aromatic ring compound by removing a hydrogen atom. It can be a monocyclic aromatic group, a condensed aromatic group, or a polycyclic aromatic group. For polycyclic rings, at least one is an aromatic ring system. For example, "C6-C 30 "Aryl" refers to an aromatic group containing 6 to 30 carbon atoms, each occurrence of which can be independently C6 aromatic, C 10 Aryl, C 14 Aryl, C 18 Aryl, C 20 Aryl or C 30 Suitable examples include, but are not limited to, benzene, biphenyl, naphthalene, anthracene, phenanthrene, perylene, triphenylene, and derivatives thereof.

[0066] "Alkylene" refers to a hydrocarbon group with two monovalent radical centers derived from an alkyl group by removing a hydrogen atom, which can be a saturated branched alkyl group or a saturated straight-chain alkyl group. For example, "C1-C6 alkylene" means that the alkyl portion contains 1 to 6 carbon atoms, and each occurrence can be independently C1 alkylene, C4 alkylene, C5 alkylene or C6 alkylene. Suitable examples include, but are not limited to: methylene (-CH2-), 1,1-ethyl (-CH(CH3)-), 1,2-ethyl (-CH2CH2-), 1,1-propyl (-CH(CH2CH3)-), 1,2-propyl (-CH2CH(CH3)-), 1,3-propyl (-CH2CH2CH2-) and 1,4-butyl (-CH2CH2CH2CH2-).

[0067] The first aspect of the present invention provides an ink, comprising a first component and a second component, wherein the first component is a polymer, and the second component has the following structural formula:

[0068]

[0069] Wherein, X includes one or more combinations of aryl groups with 5 to 60 ring atoms and heteroaryl groups with 5 to 60 ring atoms which are unsubstituted or substituted with amino, hydroxyl, carboxyl, nitro, sulfonic acid, aldehyde, thiol, and cyano groups, wherein the heteroatom in the heteroaryl group is one or more of N, S, O, P, and Si, and the number of heteroatoms is 1 to 20;

[0070] Y is a group containing halogen; m:n is (2-10):1, and m and n are both positive integers;

[0071] R1 and R2 are each independently selected from hydrogen, deuterium, amino, halogen, hydroxyl, carboxyl, nitro, sulfonic acid, aldehyde, mercapto, cyano, ether alkyl, carbonyl alkyl; C1-C2 alkyl unsubstituted or substituted by amino, halogen, hydroxyl, carboxyl, nitro, sulfonic acid, aldehyde, mercapto, cyano20 Chain hydrocarbon group, C1~C 20 The invention further comprises a chain hydrocarbonoxy group having 3 to 60 ring atoms, a cycloalkyl group having 3 to 60 ring atoms, a heterocycloalkyl group having 3 to 60 ring atoms, an aryl group having 5 to 60 ring atoms, a heteroaryl group having 5 to 60 ring atoms, an aryloxy group having 5 to 60 ring atoms, and a heteroaryloxy group having 5 to 60 ring atoms, wherein the heteroatom in the heteroaryl group or the heteroaryloxy group is N, S, O, P, or Si, and the number of heteroatoms is 1 to 20.

[0072] The ink includes a first component and a second component, and can be formed into a film by a solution method. When the solution method is used to form a film, since the second component contains a certain amount of halogen groups, the second component has a lower surface energy relative to the first component. During the solvent drying process, the difference in surface energy between the first component and the second component is large, so that the formed film undergoes vertical phase separation, and the lower layer is mainly composed of the first component, and the upper layer is mainly composed of the second component. If the amount of the halogen group in the second component is too large, the surface energy of the second component is too low, and it is difficult to form a subsequent light-emitting layer. The amount of the halogen group in the second component is within the above range, which can make the second component and the first component separate phases, and the light-emitting layer can be formed into a film. Within the above ratio range, the film mainly formed by the second component in the upper layer can reduce the damage to the lower layer during EML film formation, reduce interface mutual solubility, and thus improve the efficiency and life of the prepared OLED device.

[0073] In addition, in the second component, the side chain X containing the hole transport group and the side chain Y containing the halogen group are sequentially connected to the main chain, which has less effect on the hole transport performance of the hole transport group than directly introducing a halogen substituent on the hole transport group. If a halogen substituent is directly introduced on the hole transport group, it will usually change its energy level and affect the hole transport performance, and the structural selection is relatively limited. The preparation process of the second component is simpler, the synthesis difficulty is low, and the effect on the hole transport performance is small.

[0074] In some embodiments, the first component is an organic hole transport material. Specifically, the first component includes one or more of a polymer hole transport material and a cross-linked hole transport material. Polymer hole transport materials include triarylamine polymers, styrene polymers, carbazole polymers, etc. Cross-linked hole transport materials refer to a class of small molecule organic hole transport materials having a hole transport molecule core and a cross-linking group.

[0075] Specifically, the first component includes, but is not limited to, PVK (polyvinyl carbazole), TFB (poly [(9,9-dioctylfluorenyl-2,7-diyl)-co-(4,4'-(N-(4-sec-butylphenyl) diphenylamine)]), Poly-TPD (poly [N,N'-bis(4-butylphenyl)-N,N'-bisphenylbenzidine]), BFB (poly [(9,9-dioctylfluorenyl-2,7-diyl)-co-(N,N'-bis{4-butylphenyl}-benzidine-N,N'-{1,4-diphenyl})]), PF-Cz (structural formula: ) and PSF-Cz (structural formula is ) one or more of the following.

[0076] In some embodiments, the mass ratio of the first component to the second component is (1-20):1. In a specific example, the mass ratio of the first component to the second component may be, but is not limited to, 1:1, 2:1, 5:1, 8:1, 10:1, 12:1, 14:1, 15:1, 16:1, 18:1, 20:1 or a range consisting of any two of these values. Optionally, the mass ratio of the first component to the second component is (2.5-10):1. Preferably, the mass ratio of the first component to the second component is 5:1. Since the second component contains a halogen group that does not have hole transport properties, if the mass proportion of the second component is too large, the hole performance of the prepared hole transport layer will decrease, which will reduce the device performance. Optimizing the proportion of the first component and the second component is conducive to further improving the efficiency and life of the device. In addition, due to the blocking of the film layer where the second component is located, the accumulation of holes at the interface of the light-emitting layer can be slowed down, the TPA effect can be reduced, and the device life and efficiency can be further improved.

[0077] In some embodiments, m:n is (2-20):1. For example, m:n can be, but is not limited to, 2:1, 3:1, 4:1, 5:1, 6:1, 7:1, 8:1, 9:1, 10:1, 12:1, 14:1, 16:1, 18:1, 20:1, or a range consisting of any two of these values. Optionally, m:n is (3-5):1.

[0078] In some embodiments, m is 5 to 100, and n is 1 to 10. Alternatively, m is 10 to 30, and n is 5 to 10. In a specific example, m may be, but is not limited to, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 80, 90, 100, or a range consisting of any two of these values. In a specific example, n may be, but is not limited to, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, or a range consisting of any two of these values.

[0079] In some embodiments, X includes one or more of a carbazole group and a triarylamine group.

[0080] Specifically, X is selected from one of the following structures:

[0081] and

[0082] In some embodiments, X is selected from one of the.

[0083] In some embodiments, the structural formula of Y is as follows: wherein L1 and L2 are each independently a single bond, -O-, -S-, -CO-, -CO-O-, -O-CO-, -O-CO-O-, -CH=N-, -N=CH-, -N=N or a C1-C6 alkylene group, a is 1-6, and R3-R7 are each independently selected from hydrogen, deuterium, amino, halogen, hydroxyl, carboxyl, nitro, sulfonic acid, aldehyde, mercapto, cyano, ether alkyl, carbonyl alkyl; C1-C6 alkyl unsubstituted or substituted by amino, halogen, hydroxyl, carboxyl, nitro, sulfonic acid, aldehyde, mercapto, cyano 20 Chain hydrocarbon group, C1~C 20 The invention further comprises a chain hydrocarbonoxy group having 3 to 60 ring atoms, a cycloalkyl group having 3 to 60 ring atoms, a heterocycloalkyl group having 3 to 60 ring atoms, an aryl group having 5 to 60 ring atoms, a heteroaryl group having 5 to 60 ring atoms, an aryloxy group having 5 to 60 ring atoms, and a heteroaryloxy group having 5 to 60 ring atoms, wherein the heteroatom in the heteroaryl group or the heteroaryloxy group is one or more of N, S, O, P and Si, the number of heteroatoms is 1 to 20, and at least one of R3 to R7 is F.

[0084] Specifically, L1 and L2 are each independently a C1-C6 alkylene group. For example, L1 and L2 are each independently a methylene group, an ethylene group, a propylene group, a butylene group or a pentylene group. In a specific example, L1 is a methylene group and L2 is an ethylene group.

[0085] Specifically, the structural formula of Y is as follows: Wherein, a is 1 to 6, R3 to R7 are each independently H, F or hydroxyl, and at least three of R3 to R7 are F.

[0086] Further, Y is selected from one of the following structures:

[0087]

[0088] In one embodiment, Y is selected from one of the.

[0089] In some embodiments, R1 and R2 are each independently selected from H, D, substituted or unsubstituted C1-C6 alkyl and substituted or unsubstituted C6-C 30 One or more of the aromatic groups, substituted or unsubstituted C1-C6 alkyl groups and substituted or unsubstituted C6-C 30 The substituents in the aryl group may be, but are not limited to, C1-C6 alkyl groups, such as methyl, ethyl, propyl, and the like.

[0090] In some embodiments, R1 is a substituted or unsubstituted phenyl group. Specifically, R1 is

[0091] In some embodiments, R2 is H, D, or a substituted or unsubstituted C1-C6 alkyl group.

[0092] In some embodiments, R1 is R2 is hydrogen or For example, the synthesis route of the second component is as follows:

[0093] The specific synthesis steps can be referred to J.Am.Chem.Soc.2022,144,8084-8095. It can be understood that when R1 and R2 are other structures, they can be obtained by referring to the above synthesis.

[0094] In some embodiments, the ink further includes a solvent, which includes one or more of xylene, chlorobenzene, tetralin, cyclohexylbenzene, anisole, p-methylanisole, cyclohexanone and decalin.

[0095] In some embodiments, in the ink, the total concentration of the first component and the second component can be adjusted according to the total thickness of the hole transport layer to be prepared. For example, the total concentration of the first component and the second component can be 5 mg / mL to 200 mg / mL.

[0096] A second aspect of the present invention provides a method for preparing an electroluminescent device, comprising the following steps:

[0097] Forming a film of ink on the surface of the anode to prepare a hole transport layer, the ink being as described above;

[0098] A light-emitting layer and a cathode are formed on the surface of the hole transport layer to prepare an electroluminescent device.

[0099] The preparation method has a simple process. Through one-time film formation, the surface energy difference between the components is utilized to cause vertical phase separation, thereby being able to form a two-layer structure. The thin film in the upper layer, which is mainly formed by the second component, can reduce the damage to the lower layer during EML film formation and reduce interface mutual solubility, thereby improving the efficiency and life of the prepared OLED device.

[0100] In addition, due to the barrier of the film layer where the second component is located, the accumulation of holes at the interface of the light-emitting layer can be slowed down, and the TPA effect can be reduced, thereby further improving the efficiency and life of the prepared OLED device.

[0101] In some embodiments, the step of forming a film of the ink on the surface of the anode includes: applying the ink to the surface of the anode by one of inkjet printing, spin coating and spray coating, and then post-processing to remove the solvent.

[0102] In some embodiments, post-treatment includes one or more of vacuum drying and annealing. In the step of vacuum drying, the temperature is 0°C to 150°C, and in the step of annealing, it is carried out under an inert atmosphere at a temperature of 100°C to 300°C. For example, in the step of vacuum drying, the temperature may be, but is not limited to, 0°C, 10°C, 20°C, 50°C, 80°C, 100°C, 120°C, 150°C, or a range consisting of any two of these values. In the step of annealing, the temperature may be, but is not limited to, 100°C, 120°C, 150°C, 180°C, 200°C, 220°C, 250°C, 280°C, 300°C, or a range consisting of any two of these values. For example, the inert atmosphere may be, but is not limited to, nitrogen, argon, helium, etc.

[0103] In some embodiments, in the step of forming the light-emitting layer on the surface of the hole transport layer, a solution method is used, specifically, a solution containing the material of the light-emitting layer is formed into a film on the surface of the hole transport layer.

[0104] It can be understood that in the step of forming a film of the ink on the anode surface, the ink can be formed into a film directly on the anode surface, or can be formed into a film indirectly on the anode surface, that is, other layers can be provided on the hole transport layer and the anode surface.

[0105] In some embodiments, one or both of a hole injection layer and an electron blocking layer are further provided between the anode and the light-emitting layer, and one or more of an electron transport layer, an electron injection layer and a hole blocking layer are further provided between the cathode and the light-emitting layer. For example, at least one of an electron transport layer and an electron injection layer is provided between the cathode and the light-emitting layer. Specifically, the formation method of each layer can be commonly used in the art, for example, a hole injection layer is formed by a solution method. The hole blocking layer, the electron injection layer and the cathode are formed by an evaporation method.

[0106] In some embodiments, the method for preparing the electroluminescent device further includes: forming a hole injection layer on the surface of the anode, and forming a hole transport layer on a side of the hole injection layer away from the anode;

[0107] A hole blocking layer, an electron transport layer, and an electron injection layer are formed on a side of the light-emitting layer away from the hole transport layer, and the cathode is formed on a surface of the electron injection layer away from the light-emitting layer.

[0108] A second aspect of the present invention provides an electroluminescent device, comprising an anode, a hole transport layer, a light-emitting layer and a cathode stacked in sequence;

[0109] The hole transport layer includes a first sublayer and a second sublayer stacked in layers, wherein the first sublayer is closer to the anode than the second sublayer; the material of the first sublayer includes a polymer, and the material of the second sublayer includes a compound having the following structural formula:

[0110]

[0111] Wherein, X includes one or more combinations of aryl groups with 5 to 60 ring atoms and heteroaryl groups with 5 to 60 ring atoms which are unsubstituted or substituted with amino, hydroxyl, carboxyl, nitro, sulfonic acid, aldehyde, thiol, and cyano groups, wherein the heteroatom in the heteroaryl group is one or more of N, S, O, P, and Si, and the number of heteroatoms is 1 to 20;

[0112] Y is a group containing halogen, m:n is (2-10):1, and m, n are both positive integers;

[0113] R1 and R2 are each independently selected from hydrogen, deuterium, amino, halogen, hydroxyl, carboxyl, nitro, sulfonic acid, aldehyde, mercapto, cyano, ether alkyl, carbonyl alkyl; C1-C2 alkyl unsubstituted or substituted by amino, halogen, hydroxyl, carboxyl, nitro, sulfonic acid, aldehyde, mercapto, cyano 20 Chain hydrocarbon group, C1~C 20 The invention further comprises a chain hydrocarbonoxy group having 3 to 60 ring atoms, a cycloalkyl group having 3 to 60 ring atoms, a heterocycloalkyl group having 3 to 60 ring atoms, an aryl group having 5 to 60 ring atoms, a heteroaryl group having 5 to 60 ring atoms, an aryloxy group having 5 to 60 ring atoms, and a heteroaryloxy group having 5 to 60 ring atoms, wherein the heteroatom in the heteroaryl group or the heteroaryloxy group is one or more of N, S, O, P and Si, and the number of heteroatoms is 1 to 20.

[0114] In the above electroluminescent device, the second sublayer can reduce the damage to the first sublayer during the EML film formation and reduce the interface mutual solubility.

[0115] In some embodiments, the thickness ratio of the first sublayer to the second sublayer is (1-20):1.

[0116] Due to the blocking of the second sublayer, the accumulation of holes at the interface of the light-emitting layer can be slowed down, and the TPA effect can be reduced, thereby further improving the efficiency and life of the prepared OLED device.

[0117] In some embodiments, the total thickness of the first sublayer and the second sublayer is 20 nm to 60 nm. For example, the total thickness of the first sublayer and the second sublayer can be, but is not limited to, 20 nm, 25 nm, 30 nm, 35 nm, 40 nm, 45 nm, 50 nm, 55 nm, 60 nm, or a range consisting of any two of these values.

[0118] In some embodiments, one or both of a hole injection layer and an electron blocking layer are provided between the anode and the light-emitting layer, and one or both of an electron transport layer, an electron injection layer and a hole blocking layer are provided between the cathode and the light-emitting layer.

[0119] In some of these examples, see Figure 1 The electroluminescent device 100 includes an anode 110, a hole injection layer 120, a hole transport layer 130, an electron blocking layer 140, a light-emitting layer 150, a hole blocking layer 160, an electron transport layer 170, an electron injection layer 180, and a cathode 190 stacked in sequence. The hole transport layer 130 includes a first sublayer 132 and a second sublayer 134 stacked in layers, and the first sublayer 132 is closer to the anode 110 than the second sublayer 134. It can be understood that in some other embodiments, the electron blocking layer and the hole blocking layer can also be omitted.

[0120] It is understood that the electroluminescent device can be an upright device or an inverted device. In an upright device, the anode is the bottom electrode and the cathode is the top electrode. In an inverted device, the cathode is the bottom electrode and the anode is the top electrode.

[0121] In a specific example, the material of the anode and / or cathode includes one or more of a metal, a carbon material, and a metal oxide, the metal includes one or more of Al, Ag, Cu, Mo, Au, Ba, Ca, Yb, and Mg; the carbon material includes one or more of graphite, carbon nanotubes, graphene, and carbon fiber; the metal oxide includes a doped or undoped metal oxide, including one or more of ITO, FTO, ATO, AZO, GZO, IZO, MZO, and AMO, or includes a composite electrode in which a metal is sandwiched between doped or undoped transparent metal oxides, the composite electrode includes one or more of AZO / Ag / AZO, AZO / Al / AZO, ITO / Ag / ITO, ITO / Al / ITO, ZnO / Ag / ZnO, ZnO / Al / ZnO, ZnS / Ag / ZnS, ZnS / Al / ZnS, TiO2 / Ag / TiO2, and TiO2 / Al / TiO2.

[0122] In a specific example, the material of the hole injection layer includes TFB, CuPc, PVK, Poly-TPD, DNTPD, TCATA, TCCA, CBP, TPD, NPB, NPD, PEDOT:PSS (poly(3,4-ethylenedioxythiophene):poly(styrenesulfonic acid)), TAPC, MCC, F4-TCNQ, HATCN, 4,4',4'-tri(N-3-methylphenyl-Nphenylamino)triphenylamine, polyaniline, transition metal oxides, transition metal sulfides, transition metal tinides, doped graphene, undoped graphene and at least one of C60.

[0123] In a specific example, the light-emitting layer is a quantum dot light-emitting layer or an organic light-emitting layer.

[0124] Specifically, the material of the quantum dot light-emitting layer includes at least one of a single structure quantum dot and a core-shell structure quantum dot, and the material of the single structure quantum dot is selected from at least one of a II-VI group compound, a IV-VI group compound, a III-V group compound and a I-III-VI group compound, wherein the II-VI group compound is selected from CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, ZnO, HgS, HgSe, HgTe, CdSeS, CdSeTe, CdSTe, ZnSeS, ZnSeTe, ZnSTe, H At least one of CdZnS, CdZnSe, CdZnTe, CdHgS, CdHgSe, CdHgTe, HgZnS, HgZnSe, HgZnTe, CdZnSeS, CdZnSeTe, CdZnSTe, CdHgSeS, CdHgSeTe, CdHgSTe, HgZnSeS, HgZnSeTe and HgZnSTe, wherein the Group IV-VI compound is selected from SnS, SnSe, SnTe, PbS, PbSe, PbTe, SnS At least one of SnS, SnSeTe, SnSTe, PbSeS, PbSeTe, PbSTe, SnPbS, SnPbSe, SnPbTe, SnPbSSe, SnPbSeTe and SnPbSTe, and the III-V group compound is selected from GaN, GaP, GaAs, GaSb, AlN, AlP, AlAs, AlSb, InN, InP, InAs, InSb, GaNP, GaNAs, GaNSb, GaPAs, GaPSb, AlNP, AlNAs, AlNSb, AlPA s, AlPSb, InNP, InNAs, InNSb, InPAs, InPSb, GaAlNP, GaAlNAs, GaAlNSb, GaAlPAs, GaAlPSb, GaInNP, GaInNAs, GaInNSb, GaInPAs, GaInPSb, InAlNP, InAlNAs, InAlNSb, InAlPAs or InAlPSb, and the I-III-VI group compound is selected from at least one of CuInS2, CuInSe2 and AgInS2.

[0125] The core of the core-shell structured quantum dots includes any one of the above-mentioned single structure quantum dots, and the shell material of the core-shell structured quantum dots includes CdS, CdTe, CdSeTe, CdZnSe, CdZnS, CdSeS, ZnSe, ZnSeS, ZnS and at least one of the above-mentioned single structure quantum dots.

[0126] Specifically, the material of the organic light-emitting layer includes at least one of 4,4'-bis(N-carbazole)-1,1'-biphenyl:tris[2-(p-tolyl)pyridine-C2,N)iridium(III), 4,4',4"-tris(carbazole-9-yl)triphenylamine:tris[2-(p-tolyl)pyridine-C2,N)iridium, diaromatic anthracene derivatives, distyrene aromatic derivatives, pyrene derivatives, fluorene derivatives, TBPe fluorescent materials, TTPX fluorescent materials, TBRb fluorescent materials and DBP fluorescent materials, polyacetylene and its derivatives, polyparaphenylene and its derivatives, polythiophene and its derivatives, polyfluorene and its derivatives.

[0127] In a specific example, the material of the hole blocking layer includes, but is not limited to, TPBi (1,3,5-tris(1-phenyl-1H-benzimidazol-2-yl)benzene), and the thickness may be, but is not limited to, 30 nm.

[0128] In a specific example, the material of the electron transport layer and / or the electron injection layer includes inorganic materials and / or organic materials. Wherein, the inorganic material is selected from one or more of doped or undoped zinc oxide, barium oxide, aluminum oxide, nickel oxide, titanium oxide, tin oxide, tantalum oxide, zirconium oxide, nickel oxide, lithium titanium oxide, zinc aluminum oxide, zinc manganese oxide, zinc tin oxide, lithium zinc oxide, indium tin oxide, cadmium sulfide, zinc sulfide, molybdenum sulfide, tungsten sulfide, copper sulfide, zinc tin, indium phosphide, gallium phosphide, copper indium sulfide, copper gallium sulfide, and barium titanate, and the doped elements include one or more of aluminum, magnesium, lithium, manganese, yttrium, lanthanum, copper, nickel, zirconium, cerium, and gadolinium. The organic material is selected from one or more of quinoxaline compounds, imidazole compounds, triazine compounds, fluorene compounds, and hydroxyquinoline compounds.

[0129] It can be understood that the material and thickness of each layer can be commonly used in the art. The above only gives a specific example, but is not limited to this.

[0130] A fourth aspect of the present invention provides a display device comprising the above-mentioned electroluminescent device.

[0131] In order to make the purpose and advantages of the present invention clearer, the electroluminescent device of the present invention and its effects are further described in detail below in conjunction with specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and shall not be used to limit the present invention. The following embodiments do not include other components except inevitable impurities unless otherwise specified. The drugs and instruments used in the embodiments are conventionally selected in the art unless otherwise specified. The experimental methods for which specific conditions are not specified in the embodiments are implemented according to conventional conditions, such as the conditions described in the literature, books, or the methods recommended by the manufacturer.

[0132] Example 1

[0133] This embodiment provides an electroluminescent device, and the preparation steps are as follows:

[0134] (1) The ITO anode substrate was cleaned and then treated under UV conditions for 15 minutes to increase its work function and wettability.

[0135] (2) PEDOT:PSS was spin-coated on the treated ITO anode substrate and then baked at 150°C for 20 min in an air atmosphere to obtain a hole injection layer with a thickness of 50 nm.

[0136] (3) Spin-coating ink on the surface of the hole injection layer, and then baking at 150°C for 30 min in a nitrogen environment to form a hole transport layer with a total thickness of 40 nm. Among them, the first component in the ink is PF-Cz (structural formula is For material synthesis, see: 10.1039 / c5tc03665h). In the second component, X is selected from (1), Y is selected from (3), R is selected from H, m and n are 20 and 5 respectively, and the mass ratio of the first component to the second component is 5:1. In the ink, the solvent is cyclohexylbenzene.

[0137] (4) A solution containing a light-emitting layer material is spin-coated on the surface of the hole transport layer, and then baked at 150° C. for 10 min to obtain a light-emitting layer with a thickness of 40 nm. The light-emitting layer material includes TPAF:B3PYMPM:Ir(ppy)3 in a mass ratio of 4.6:4.6:0.8.

[0138] (5) A TPBi (1,3,5-tris(1-phenyl-1H-benzimidazol-2-yl)benzene) hole blocking layer with a thickness of 30 nm, a LiF electron injection layer with a thickness of 1 nm, and an Al cathode with a thickness of 100 nm are formed on the surface of the light-emitting layer by vacuum evaporation in sequence, and then packaged and annealed at 80° C. for 30 min to obtain an electroluminescent device.

[0139] Example 2

[0140] This embodiment provides an electroluminescent device, and the preparation steps are similar to those of Embodiment 1, except that the ink used to prepare the hole transport layer is different. In this embodiment, the first component is PF-Cz (material synthesis see: 10.1039 / c5tc03665h), X in the second component is selected from (1), Y is selected from (3), R is selected from H, m and n are 20 and 2 respectively, and the mass ratio of the first component to the second component is 5:1. The remaining conditions are the same as those of Embodiment 1.

[0141] Example 3

[0142] This embodiment provides an electroluminescent device, and the preparation steps are similar to those of Embodiment 1, except that the ink used to prepare the hole transport layer is different. In this embodiment, the first component is PF-Cz (material synthesis see: 10.1039 / c5tc03665h), in the second component, X is selected from (1), Y is selected from (3), R is selected from H, m and n are 20 and 10 respectively, and the mass ratio of the first component to the second component is 5:1. The remaining conditions are the same as those of Embodiment 1.

[0143] Example 4

[0144] This embodiment provides an electroluminescent device, and the preparation steps are similar to those of Embodiment 1, except that the ink used to prepare the hole transport layer is different. In this embodiment, the first component is PF-Cz (material synthesis see: 10.1039 / c5tc03665h), X in the second component is selected from (5), Y is selected from (3), R is selected from H, m and n are 20 and 5 respectively, and the mass ratio of the first component to the second component is 5:1. The remaining conditions are the same as those of Embodiment 1.

[0145] Example 5

[0146] This embodiment provides an electroluminescent device, and the preparation steps are similar to those of Embodiment 1, except that the ink used to prepare the hole transport layer is different. In this embodiment, the first component is PF-Cz (material synthesis see: 10.1039 / c5tc03665h), X in the second component is selected from (5), Y is selected from (6), R is selected from H, m and n are 20 and 5 respectively, and the mass ratio of the first component to the second component is 5:1. The other conditions are the same as those of Embodiment 1.

[0147] Example 6

[0148] This embodiment provides an electroluminescent device. The preparation steps are similar to those of Embodiment 1. The difference is that the ink used to prepare the hole transport layer is different. In this embodiment, the first component is PSF-Cz (structural formula: For material synthesis, see: 10.1039 / c5tc03665h), in the second component, X is selected from (1), Y is selected from (3), R is selected from H, m and n are 20 and 5 respectively, and the mass ratio of the first component to the second component is 5:1. The other conditions are the same as those in Example 1.

[0149] Example 7

[0150] This embodiment provides an electroluminescent device, and the preparation steps are similar to those of Embodiment 1, except that the ink used to prepare the hole transport layer is different. In this embodiment, the first component is PSF-Cz (material synthesis see: 10.1039 / c5tc03665h), in the second component, X is selected from (1), Y is selected from (3), R is selected from H, m and n are 20 and 5 respectively, and the mass ratio of the first component to the second component is 1:1.2. The remaining conditions are the same as those of Embodiment 1.

[0151] Comparative Example 1

[0152] Comparative Example 1 provides an electroluminescent device, and the preparation steps are as follows:

[0153] (1) The ITO anode substrate was cleaned and then treated under UV conditions for 15 minutes to increase its work function and wettability.

[0154] (2) PEDOT:PSS was spin-coated on the treated ITO anode substrate and then baked at 150°C for 20 min in an air atmosphere to obtain a hole injection layer with a thickness of 50 nm.

[0155] (3) Spin-coat the surface of the hole injection layer with PF-Cz solution (for material synthesis, see: 10.1039 / c5tc03665h), and then bake at 150°C for 30 min in a nitrogen environment to obtain a hole transport layer with a thickness of 40 nm.

[0156] (4) A solution containing a light-emitting layer material is spin-coated on the surface of the hole transport layer, and then baked at 150° C. for 10 min to obtain a light-emitting layer with a thickness of 40 nm. The light-emitting layer material includes TPAF:B3PYMPM:Ir(ppy)3 in a mass ratio of 4.6:4.6:0.8.

[0157] (5) A TPBi hole blocking layer with a thickness of 30 nm, a LiF electron injection layer with a thickness of 1 nm, and an Al cathode with a thickness of 100 nm are formed on the surface of the light-emitting layer by vacuum evaporation in sequence, and then packaged and annealed at 80° C. for 30 min to obtain an electroluminescent device.

[0158] Comparative Example 2

[0159] Comparative Example 2 provides an electroluminescent device, and the preparation steps are similar to those of Example 1, except that the ink used to prepare the hole transport layer is different. In Comparative Example 2, the first component is PF-Cz (material synthesis see: 10.1039 / c5tc03665h), in the second component, X is selected from (1), Y is selected from (3), R is selected from H, m and n are 20 and 0 respectively, and the mass ratio of the first component to the second component is 5:1. The other conditions are the same as those of Example 1.

[0160] Comparative Example 3

[0161] Comparative Example 3 provides an electroluminescent device, and the preparation steps are similar to those of Example 1, except that the ink used to prepare the hole transport layer is different. In Comparative Example 3, the first component is PF-Cz (material synthesis see: 10.1039 / c5tc03665h), in the second component, X is selected from (1), Y is selected from (3), R is selected from H, m and n are 20 and 15 respectively, and the mass ratio of the first component to the second component is 5:1. The other conditions are the same as those of Example 1.

[0162] The synthetic route of the second component in the above embodiments and comparative examples of ink is as follows:

[0163]

[0164] Taking Example 1 as an example, the synthesis steps of the second component are as follows:

[0165] (1) In a 25 mL Schlenk flask with a magnetic stirrer, add 0.15 mmol of trithiocarbonylbenzyl ethyl ester and 8 mmol of CH2=CH-X (X is ), 0.015mmol of AIBN [2,2′-azobis(2-methylpropionitrile)] and 17mL of anhydrous 1,4-dioxane. The above reaction solution was subjected to 4 cycles of liquid nitrogen freezing-vacuuming-nitrogen thawing, then dehydrated and deoxygenated, and then backfilled with nitrogen. The reaction solution was then stirred at room temperature for 10 minutes, and transferred to a 62°C oil bath for polymerization for 40 hours, and then the reaction bottle was cooled with liquid nitrogen to terminate the polymerization. The mixture was diluted with 5mL of tetrahydrofuran and precipitated with 140mL of methanol, and repeated twice. The precipitate was centrifuged and vacuum dried for 30 hours to obtain compound 1 with a yield of 61%. The test Mn=8912Da, molecular weight distribution

[0166] (2) In a 25 mL Schlenk flask with a magnetic stirrer, 0.1 mmol of compound 1 and 4 mmol of CH2=CH-Y (Y is ), 0.008 mmol of AIBN and 3 mL of 1,4-dioxane. After the mixture was stirred at room temperature for 10 minutes, the solution was subjected to 4 cycles of liquid nitrogen freezing-vacuuming-nitrogen thawing for dehydration and deoxygenation, and then backfilled with nitrogen. The reaction mixture was then stirred at room temperature for 10 minutes and transferred to a 62°C oil bath for polymerization for 20 hours, and then the polymerization was terminated by cooling the reaction flask with liquid nitrogen. The mixture was diluted with 7 mL of tetrahydrofuran and precipitated with 140 mL of methanol, and repeated twice. The precipitate was centrifuged and vacuum dried for 30 hours to obtain compound 2 with a yield of 57%. Test Mn = 10412 Da,

[0167] (3) Add 0.02 mmol of compound 2, 0.98 mmol of 1-ethylpiperidinium hypophosphite (EPHP), 0.012 mmol of 1,1′-azobis(cyclohexanecarbonitrile) (ACHN) and 2.45 mL of anhydrous o-xylene to a 25 mL Schlenk flask with a magnetic stirrer. The mixture was dehydrated and deoxygenated by 4 cycles of liquid nitrogen freezing-vacuuming-nitrogen thawing, and then backfilled with nitrogen. The reaction mixture was then transferred to a 110°C oil bath and stirred for 3 h, and then the reaction flask was cooled with liquid nitrogen to terminate the polymerization. The mixture was diluted with 4 mL of toluene, washed three times with 5 mL of deionized water, and washed twice with 5 mL of brine. The extract was precipitated with 90 mL of methanol and centrifuged, repeated twice, and then vacuum concentrated for 30 h to obtain compound 3, i.e., the second component, with a yield of 61.3%. The test Mn = 10387 Da,

[0168] The steps of the second component in other embodiments and comparative examples refer to the above steps and are not repeated here. The characterization of the second component in each embodiment and comparative example is shown in Table 1 below. Wherein, the structures (1) and (5) corresponding to X are respectively The structures (3) and (6) corresponding to Y are

[0169] Table 1 Characterization of the second component of each embodiment and comparative example

[0170]

[0171] Taking Example 1 as an example, the water contact angle of the surface of the hole transport layer prepared after step (3) was tested. When the ink contained only the first component and the solvent of Example 1, the contact angle of the surface of the prepared hole transport layer was 89°; when the ink contained the first component, the second component and the solvent of Example 1 at the same time, the contact angle of the surface of the hole transport layer was 97°; when the ink contained only the second component and the solvent of Example 1, the contact angle of the surface of the hole transport layer was 99°. It can be seen that when the ink contains the first component and the second component at the same time, phase separation can occur, and the upper surface of the formed hole transport layer is rich in the second component. The contact angles of other embodiments are similar to those of Example 1 and will not be repeated.

[0172] The performance of the electroluminescent devices prepared in the above examples and comparative examples was tested using IVL equipment, and the life of the electroluminescent devices was measured using life aging equipment. Specifically, at a current density of 10 mA / cm 2The voltage at (J10) is used as the driving voltage index, the current efficiency at a brightness of 1000 nit is used as the efficiency index, and the time when the brightness decays to 95% under constant current conditions at an initial brightness of 1000 nit is used as the life evaluation index. The performance of the electroluminescent devices of each embodiment and comparative example is shown in Table 2:

[0173] Table 2 Performance data of electroluminescent devices of various embodiments and comparative examples

[0174]

[0175] As can be seen from Table 2, the driving voltage, current efficiency and life of the electroluminescent device prepared in the embodiment are better than those of the comparative example. When the fluorinated side chain is not introduced into the HTL, the efficiency and life of the electroluminescent device are poor due to the destruction of the hole transport layer by the light-emitting layer. After the second component adopts the fluorinated side chain, the device performance is improved. At the same time, when the ratio of fluorinated side chains n is small, the device performance is not significantly improved, probably due to the poor vertical phase separation effect. After the ratio of fluorinated side chains increases to n=15, the surface energy is significantly reduced, and the EML is difficult to form a film and cannot emit light uniformly. Optimizing the mass proportion of the second component is conducive to further improving the device performance.

[0176] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0177] The above-described embodiments only express several implementation methods of the present invention, which is convenient for understanding the technical solutions of the present invention in detail, but cannot be understood as limiting the scope of protection of the invention patent. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention. It should be understood that the technical solutions obtained by those skilled in the art through logical analysis, reasoning or limited experiments on the basis of the technical solutions provided by the present invention are all within the protection scope of the claims attached to the present invention. Therefore, the protection scope of the patent of the present invention shall be based on the contents of the attached claims, and the description and drawings can be used to interpret the contents of the claims.

Claims

1. An ink, characterized in that: include: The first component and the second component, The first component is a polymer, The structural formula of the second component is as follows: Wherein, X includes one or more combinations of aryl groups with 5 to 60 ring atoms and heteroaryl groups with 5 to 60 ring atoms which are unsubstituted or substituted with amino, hydroxyl, carboxyl, nitro, sulfonic acid, aldehyde, thiol, and cyano groups, wherein the heteroatom in the heteroaryl group is one or more of N, S, O, P, and Si, and the number of heteroatoms is 1 to 20; Y is a group containing halogen; m:n is (2-20):1, and both m and n are positive integers; R1 and R2 are each independently selected from hydrogen, deuterium, amino, halogen, hydroxyl, carboxyl, nitro, sulfonic acid, aldehyde, mercapto, cyano, ether alkyl, carbonyl alkyl; C1-C2 alkyl unsubstituted or substituted by amino, halogen, hydroxyl, carboxyl, nitro, sulfonic acid, aldehyde, mercapto, cyano 20 Chain hydrocarbon group, C1~C 20 The invention further comprises a chain hydrocarbonoxy group having 3 to 60 ring atoms, a cycloalkyl group having 3 to 60 ring atoms, a heterocycloalkyl group having 3 to 60 ring atoms, an aryl group having 5 to 60 ring atoms, a heteroaryl group having 5 to 60 ring atoms, an aryloxy group having 5 to 60 ring atoms, and a heteroaryloxy group having 5 to 60 ring atoms, wherein the heteroatom in the heteroaryl group or the heteroaryloxy group is one or more of N, S, O, P and Si, and the number of heteroatoms is 1 to 20.

2. The ink according to claim 1, characterized in that The structural formula of Y is as follows: L1 and L2 are each independently a single bond, -O-, -S-, -CO-, -CO-O-, -O-CO-, -O-CO-O-, -CH=N-, -N=CH-, -N=N or a C1-C6 alkylene group; a is 1-6; R3 to R7 are each independently selected from hydrogen, deuterium, amino, halogen, hydroxyl, carboxyl, nitro, sulfonic acid, aldehyde, mercapto, cyano, ether alkyl, carbonyl alkyl; C1 to C2 unsubstituted or substituted by amino, halogen, hydroxyl, carboxyl, nitro, sulfonic acid, aldehyde, mercapto, cyano 20 Chain hydrocarbon group, C1~C 20 The invention further comprises a chain hydrocarbonoxy group having 3 to 60 ring atoms, a cycloalkyl group having 3 to 60 ring atoms, a heterocycloalkyl group having 3 to 60 ring atoms, an aryl group having 5 to 60 ring atoms, a heteroaryl group having 5 to 60 ring atoms, an aryloxy group having 5 to 60 ring atoms, and a heteroaryloxy group having 5 to 60 ring atoms, wherein the heteroatom in the heteroaryl group or the heteroaryloxy group is one or more of N, S, O, P and Si, and the number of heteroatoms is 1 to 20; and at least one of R3 to R7 is fluorine.

3. The ink according to claim 2, characterized in that Y is selected from one of the following structures:

4. The ink according to claim 1, characterized in that X includes one or more of a carbazole group and a triarylamine group.

5. The ink according to claim 4, characterized in that X is selected from one of the following structures:

6. The ink according to any one of claims 1 to 5, characterized in that: The second component satisfies one or more of the following conditions (1) to (5): (1) m is 5 to 100, n is 1 to 10; (2) m:n is (3-5):1; (3) The mass ratio of the first component to the second component is (2.5-10):1; (4) R1 is (5) R2 is hydrogen or 7. The ink according to any one of claims 1 to 5, characterized in that: The first component includes polyvinyl carbazole, poly[(9,9-dioctylfluorenyl-2,7-diyl)-co-(4,4'-(N-(4-sec-butylphenyl)diphenylamine)]), poly[N,N'-bis(4-butylphenyl)-N,N'-bisphenylbenzidine], poly[(9,9-dioctylfluorenyl-2,7-diyl)-co-(4,4'-(N-(4-sec-butylphenyl)diphenylamine)], poly[N,N'-bis(4-butylphenyl)-N,N'-bisphenylbenzidine], poly[(9,9-dioctylfluorenyl-2,7-diyl)-co-(N,N'-bis{4-butylphenyl}-benzidine-N,N'-{1,4-diphenyl})], and One or more of the .

8. The ink according to any one of claims 1 to 5, characterized in that The mass ratio of the first component to the second component is (1-20):1; and / or, The surface energy of the first component is greater than the surface energy of the second component.

9. The ink according to any one of claims 1 to 5, characterized in that: The ink further comprises a solvent, and the solvent comprises one or more of xylene, chlorobenzene, tetralin, cyclohexylbenzene, anisole, p-methylanisole, cyclohexanone and decalin.

10. A method for preparing an electroluminescent device, characterized in that: The steps include: Forming an ink film on the surface of the anode to prepare a hole transport layer, wherein the ink is as described in any one of claims 1 to 9; A light-emitting layer and a cathode are formed on the surface of the hole transport layer to prepare an electroluminescent device.

11. The method for preparing an electroluminescent device according to claim 10, characterized in that: The step of forming a film of the ink on the surface of the anode includes: applying the ink to the surface of the anode, and then performing post-treatment to form the ink into a film, wherein the post-treatment includes one or more of vacuum drying and annealing treatment, wherein the vacuum drying step is performed at a temperature of 0°C to 150°C, and the annealing step is performed under an inert atmosphere at a temperature of 100°C to 300°C.

12. An electroluminescent device, characterized in that: It includes an anode, a hole transport layer, a light-emitting layer and a cathode which are stacked in sequence; The hole transport layer includes a first sublayer and a second sublayer stacked in layers, wherein the first sublayer is closer to the anode than the second sublayer; the material of the first sublayer includes a polymer, and the material of the second sublayer includes a compound having the following structural formula: Wherein, X includes one or more combinations of aryl groups with 5 to 60 ring atoms and heteroaryl groups with 5 to 60 ring atoms which are unsubstituted or substituted with amino, hydroxyl, carboxyl, nitro, sulfonic acid, aldehyde, thiol, and cyano groups, wherein the heteroatom in the heteroaryl group is one or more of N, S, O, P, and Si, and the number of heteroatoms is 1 to 20; Y is a group containing halogen; m:n is (2-20):1, and m, n are both positive integers; R1 and R2 are each independently selected from hydrogen, deuterium, amino, halogen, hydroxyl, carboxyl, nitro, sulfonic acid, aldehyde, mercapto, cyano, ether alkyl, carbonyl alkyl; C1-C2 alkyl unsubstituted or substituted by amino, halogen, hydroxyl, carboxyl, nitro, sulfonic acid, aldehyde, mercapto, cyano 20 Chain hydrocarbon group, C1~C 20 The invention further comprises a chain hydrocarbonoxy group having 3 to 60 ring atoms, a cycloalkyl group having 3 to 60 ring atoms, a heterocycloalkyl group having 3 to 60 ring atoms, an aryl group having 5 to 60 ring atoms, a heteroaryl group having 5 to 60 ring atoms, an aryloxy group having 5 to 60 ring atoms, and a heteroaryloxy group having 5 to 60 ring atoms, wherein the heteroatom in the heteroaryl group or the heteroaryloxy group is one or more of N, S, O, P and Si, and the number of heteroatoms is 1 to 20.

13. The electroluminescent device according to claim 12, characterized in that The thickness ratio of the first sublayer to the second sublayer is (1-20):

1.

14. The electroluminescent device according to claim 12 or 13, characterized in that: The electroluminescent device comprises a cathode, an electron injection layer, an electron transport layer, a light emitting layer, a hole transport layer, a hole injection layer and an anode which are stacked in sequence.

15. The electroluminescent device according to claim 14, characterized in that The electroluminescent device satisfies one or more of the following conditions (1) to (4): (1) The material of the anode and / or the cathode includes one or more of metal, carbon material and metal oxide, wherein the metal includes one or more of Al, Ag, Cu, Mo, Au, Ba, Ca, Yb and Mg; the carbon material includes one or more of graphite, carbon nanotubes, graphene and carbon fiber; the metal oxide includes doped or undoped metal oxide, including one or more of ITO, FTO, ATO, AZO, GZO, IZO, MZO and AMO, or includes a composite electrode in which a metal is sandwiched between doped or undoped transparent metal oxides, wherein the composite electrode includes one or more of AZO / Ag / AZO, AZO / Al / AZO, ITO / Ag / ITO, ITO / Al / ITO, ZnO / Ag / ZnO, ZnO / Al / ZnO, ZnS / Ag / ZnS, ZnS / Al / ZnS, TiO2 / Ag / TiO2 and TiO2 / Al / TiO2; (2) The light-emitting layer is a quantum dot light-emitting layer or an organic light-emitting layer; The material of the quantum dot light-emitting layer includes at least one of a single structure quantum dot and a core-shell structure quantum dot, and the material of the single structure quantum dot is selected from at least one of a II-VI group compound, a IV-VI group compound, a III-V group compound and a I-III-VI group compound, wherein the II-VI group compound is selected from CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, ZnO, HgS, HgSe, HgTe, CdSeS, CdSeTe, CdSTe, ZnSeS, ZnSeTe, ZnSTe, Hg At least one of CdZnS, CdZnSe, CdZnTe, CdHgS, CdHgSe, CdHgTe, HgZnS, HgZnSe, HgZnTe, CdZnSeS, CdZnSeTe, CdZnSTe, CdHgSeS, CdHgSeTe, CdHgSTe, HgZnSeS, HgZnSeTe and HgZnSTe, wherein the Group IV-VI compound is selected from SnS, SnSe, SnTe, PbS, PbSe, PbTe, SnSe At least one of SnS, SnSeTe, SnSTe, PbSeS, PbSeTe, PbSTe, SnPbS, SnPbSe, SnPbTe, SnPbSSe, SnPbSeTe and SnPbSTe, and the III-V group compound is selected from GaN, GaP, GaAs, GaSb, AlN, AlP, AlAs, AlSb, InN, InP, InAs, InSb, GaNP, GaNAs, GaNSb, GaPAs, GaPSb, AlNP, AlNAs, AlNSb, AlPAs , at least one of AlPSb, InNP, InNAs, InNSb, InPAs, InPSb, GaAlNP, GaAlNAs, GaAlNSb, GaAlPAs, GaAlPSb, GaInNP, GaInNAs, GaInNSb, GaInPAs, GaInPSb, InAlNP, InAlNAs, InAlNSb, InAlPAs or InAlPSb, and the I-III-VI group compound is selected from at least one of CuInS2, CuInSe2 and AgInS2; The core of the quantum dot with a core-shell structure includes any one of the quantum dots with a single structure, and the shell material of the quantum dot with a core-shell structure includes at least one of CdS, CdTe, CdSeTe, CdZnSe, CdZnS, CdSeS, ZnSe, ZnSeS, ZnS and the quantum dots with a single structure; The material of the organic light-emitting layer includes at least one of 4,4'-bis(N-carbazole)-1,1'-biphenyl:tris[2-(p-tolyl)pyridine-C2,N)iridium(III), 4,4',4"-tris(carbazole-9-yl)triphenylamine:tris[2-(p-tolyl)pyridine-C2,N)iridium, diarylanthracene derivatives, distilbene aromatic derivatives, pyrene derivatives, fluorene derivatives, TBPe fluorescent materials, TTPX fluorescent materials, TBRb fluorescent materials and DBP fluorescent materials, polyacetylene and its derivatives, polyparaphenylene and its derivatives, polythiophene and its derivatives, polyfluorene and its derivatives; (3) The material of the hole injection layer includes at least one of TFB, CuPc, PVK, Poly-TPD, DNTPD, TCATA, TCCA, CBP, TPD, NPB, NPD, PEDOT:PSS, TAPC, MCC, F4-TCNQ, HATCN, 4,4',4'-tris(N-3-methylphenyl-N-phenylamino)triphenylamine, polyaniline, transition metal oxide, transition metal sulfide, transition metal tinide, doped graphene, undoped graphene and C60; (4) The material of the electron transport layer and / or the electron injection layer includes inorganic materials and / or organic materials, wherein the inorganic material is selected from one or more of doped or undoped zinc oxide, barium oxide, aluminum oxide, nickel oxide, titanium oxide, tin oxide, tantalum oxide, zirconium oxide, nickel oxide, lithium titanium oxide, zinc aluminum oxide, zinc manganese oxide, zinc tin oxide, lithium zinc oxide, indium tin oxide, cadmium sulfide, zinc sulfide, molybdenum sulfide, tungsten sulfide, copper sulfide, zinc tin, indium phosphide, gallium phosphide, copper indium sulfide, copper gallium sulfide, and barium titanate, and the doped elements include one or more of aluminum, magnesium, lithium, manganese, yttrium, lanthanum, copper, nickel, zirconium, cerium, and gadolinium, and the organic material is selected from one or more of quinoxaline compounds, imidazole compounds, triazine compounds, fluorene-containing compounds, and hydroxyquinoline compounds.

16. A display device, characterized in that: The invention comprises the electroluminescent device according to claims 12 to 15 or the electroluminescent device prepared by the preparation method according to any one of claims 10 to 11.

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