A self-crosslinking compound, thin film, optoelectronic device and display device

Abstract

This application belongs to the field of display technology and relates to a self-crosslinking compound, a thin film, an optoelectronic device, and a display apparatus. The self-crosslinking compound can reduce surface defects and stress in inorganic perovskite materials.

Description

Technical Field

[0001] This application relates to the field of display technology, and more specifically, to a self-crosslinking compound, a thin film, an optoelectronic device, and a display apparatus. Background Technology

[0002] When inorganic perovskite materials are fabricated into thin films, they have many surface defects, which leads to low current efficiency and lifespan of thin films containing inorganic perovskite materials. Summary of the Invention

[0003] To address the aforementioned technical problems, this application provides a self-crosslinking compound, which employs the following technical solution:

[0004] A self-crosslinking compound, the general structural formula of which is:

[0005]

[0006] Each of A1, A2, and A3 is independently selected from at least one of substituted or unsubstituted C2-C10 alkenyl, substituted or unsubstituted C2-C10 enoyl, substituted or unsubstituted C2-C10 enoyloxycarbonyl, and substituted or unsubstituted C2-C10 enoyloxy. When substituted, each of the substituents is independently selected from one or more combinations of hydrogen, deuterium, halogen, amino, hydroxyl, carboxyl, nitro, sulfonic acid, mercapto, cyano, C1-C30 alkyl, aryl with 6-30 ring atoms, and heteroaryl with 5-30 ring atoms.

[0007] X - Selected from F - Cl - ,Br - I - I3 - BF4 - PF6 - SbF6 - AsF6 - NO2 - NO3 - SCN - CN - HCO3 - HSO4 - H2PO4 - HCOO - CH3COO - CF3COO - CF3SO3 - C4F9SO3 - CF3(C6H4)SO3- CH3(C6H4)SO3 - (CF3SO2)2N - FeCl4 - (CN)2N - And one or more of 7,7-dimethyl-2-oxobicyclo[2.2.1]heptane-1-methanesulfonate.

[0008] Accordingly, this application also provides an optoelectronic device, which includes a first electrode, a functional layer and a second electrode stacked sequentially.

[0009] The functional layer is located between the first electrode and the second electrode, and the functional layer is a thin film as described in any of the above embodiments.

[0010] Accordingly, this application also provides a display device, which includes the optoelectronic device described in any of the above embodiments.

[0011] Compared with the prior art, the embodiments of this application have the following main advantages:

[0012] Self-crosslinking compounds can reduce surface defects and stress in inorganic perovskite materials. Attached Figure Description

[0013] To more clearly illustrate the solutions in this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0014] Figure 1 This is a schematic diagram of the structure of the thin film according to an embodiment of this application;

[0015] Figure 2 This is a schematic diagram of the structure of the optoelectronic device according to an embodiment of this application.

[0016] Figure label:

[0017] Thin film 10, first film layer 11, second film layer 12, optoelectronic device 20, first electrode 100, hole injection layer 200, hole transport layer 300, electron transport layer 400, second electrode 600. Detailed Implementation

[0018] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application. Furthermore, it should be understood that the specific embodiments described herein are only for illustration and explanation of this application and are not intended to limit this application.

[0019] In this application, unless otherwise stated, directional terms such as "upper" and "lower" generally refer to the upper and lower positions of the device in its actual use or operating state, specifically the orientation shown in the accompanying drawings; while "inner" and "outer" refer to the outline of the device. Furthermore, in the description of this application, the term "comprising" means "including but not limited to". The terms first, second, third, etc., are used merely as illustrative purposes and do not impose numerical requirements or establish a numerical order.

[0020] In this application, "and / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. A and B can be singular or plural.

[0021] In this application, "at least one" means one or more, and "more than one" means two or more. "At least one," "at least one of the following," or similar expressions refer to any combination of these items, including any combination of single or multiple items. For example, "at least one of a, b, or c," or "at least one of a, b, and c," can both mean: a, b, c, a-b (i.e., a and b), a-c, b-c, or a-b-c, where a, b, and c can be single or multiple.

[0022] Various embodiments of this application may exist in the form of a range; it should be understood that the description in the form of a range is merely for convenience and brevity and should not be construed as a hard limitation on the scope of this application; therefore, it should be considered that the range description has specifically disclosed all possible sub-ranges and single numerical values ​​within that range. For example, it should be considered that the range description from 1 to 6 has specifically disclosed sub-ranges such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6, etc., and single numbers within the range, such as 1, 2, 3, 4, 5, and 6, regardless of the range. Furthermore, whenever a numerical range is referred to herein, it means including any referenced number (fraction or integer) within the referred range.

[0023] In the prior art, metal ions such as lead ions in inorganic perovskite materials may be uncoordinated. The electron cloud distribution around uncoordinated lead ions is different from that in the normal coordination state, which will generate additional energy levels in the band gap, thereby forming certain surface defects. Surface defects will cause charge carriers to recombine at the defect sites, resulting in low current efficiency and low lifespan of thin films containing inorganic perovskite materials.

[0024] This application provides a self-crosslinking compound, the general structural formula of which is:

[0025]

[0026] Each of A1, A2, and A3 is independently selected from at least one of substituted or unsubstituted C2-C10 alkenyl, substituted or unsubstituted C2-C10 enoyl, substituted or unsubstituted C2-C10 enoyloxycarbonyl, and substituted or unsubstituted C2-C10 enoyloxy. When substituted, each substituent is independently selected from one or more combinations of hydrogen, deuterium, halogen, amino, hydroxyl, carboxyl, nitro, sulfonic acid, mercapto, cyano, C1-C30 alkyl, aryl with 6-30 ring atoms, and heteroaryl with 5-30 ring atoms.

[0027] X - Selected from F - Cl - ,Br - I - I3 - BF4 - PF6 - SbF6 - AsF6 - NO2 - NO3 - SCN - CN - HCO3 - HSO4 - H2PO4 - HCOO - CH3COO - CF3COO - CF3SO3 - C4F9SO3 - CF3(C6H4)SO3 - CH3(C6H4)SO3 - (CF3SO2)2N - FeCl4 - (CN)2N -And one or more of 7,7-dimethyl-2-oxobicyclo[2.2.1]heptane-1-methanesulfonate.

[0028] In this embodiment, A1 and A3 are capable of self-crosslinking and drive the self-crosslinking compound to form a three-dimensional mesh structure. When the self-crosslinking compound is used to passivate inorganic perovskite materials, the three-dimensional mesh structure, during its formation, can restrict and drive the metal ions (e.g., lead ions) in the inorganic perovskite material to arrange themselves in a three-dimensional mesh structure order, so that the metal ions are restored to a certain extent to their normal coordination state. Furthermore, because the three-dimensional mesh structure can also release the residual stress on the surface of the inorganic perovskite material, the self-crosslinking compound of this embodiment can effectively eliminate surface defects of the inorganic perovskite material. At the same time, because the nitrogen atom in the thiophene imidazole group of the self-crosslinking compound contains at least one positive charge, it can attract halides to fill the halide vacancies, thereby preventing the halide vacancies from hindering electron and / or hole transport. Finally, the benzene ring in the self-crosslinking compound will generate π-π stacking due to conjugation, thereby enhancing the current density of the film containing the self-crosslinking compound.

[0029] In summary, the self-crosslinking compounds of this application can effectively passivate defects in inorganic perovskite materials and increase the current density of films containing inorganic perovskite materials during the self-crosslinking process.

[0030] Furthermore, A1 and A3 are each independently selected from at least one of the following structural formulas:

[0031]

[0032] Wherein, n is selected from an integer from 0 to 2, and R1, R2, R3, R4, R5, R6, R7, R8, R9, R11 and R12 are each independently selected from one or more combinations of hydrogen, deuterium, halogen, amino, hydroxyl, carboxyl, nitro, sulfonic acid, mercapto, cyano, C1 to C30 alkyl, aryl with 6 to 30 ring atoms, and heteroaryl with 5 to 30 ring atoms.

[0033] In this embodiment, the groups of A1 and A3 can achieve self-crosslinking by increasing the self-crosslinking efficiency under relatively common environments (such as ultraviolet light irradiation or heating lamp environment) through carbon-carbon double bonds, thereby forming a three-dimensional mesh structure.

[0034] Furthermore, the self-crosslinking compound is selected from at least one of the structural formulas shown in Formulas 1 to 5:

[0035]

[0036]

[0037] In this embodiment, the aforementioned self-crosslinking compound can efficiently perform self-crosslinking and eliminate residual stress on the surface of the inorganic perovskite material. Simultaneously, the positive charge of the nitrogen atom in the thiophene imidazole group of the self-crosslinking compound attracts halides from the inorganic perovskite material to fill halide vacancies, thereby preventing halide vacancies from hindering electron and / or hole transport. Finally, the benzene ring in the self-crosslinking compound will generate π-π stacking due to conjugation, thereby enhancing the electron transport efficiency of the film containing the self-crosslinking compound. In summary, the self-crosslinking compound of this embodiment can improve the elimination of surface defects in inorganic perovskite materials and attract their halides to fill halide vacancies, thereby improving the current efficiency of the film containing the inorganic perovskite material.

[0038] Accordingly, this application also provides a method for preparing a self-crosslinking compound, comprising the following steps:

[0039] Thiophene-imidazole, the cross-linked group preform, and the solvent were mixed to obtain a mixed solution;

[0040] The mixture was extracted with excess extractant and then filtered to obtain a self-crosslinking compound.

[0041] The crosslinked group preform includes at least one of 1-(chloromethyl)-2-vinylbenzene, 1-(chloromethyl)-2-allylic, 1-(chloromethyl)-2-methacrylate, and 1-(chloromethyl)-2-acrylate.

[0042] In this embodiment, taking 1-(chloromethyl)-2-vinylbenzene as an example, the active site (nitrogen atom) in thiophene imidazole can undergo a nucleophilic substitution reaction with the chloromethyl carbon atom, thereby allowing the vinylphenyl group to be attached to the nitrogen atom in thiophene imidazole. The extractant can utilize its solubility to dissolve the self-crosslinked compound, thereby removing other impurities from the self-crosslinked compound.

[0043] Furthermore, the specific steps for mixing thiophene imidazole, the cross-linked preform, and the solvent are as follows:

[0044] Mix thiophene imidazole, cross-linked preform, basic substance, and solvent; and / or,

[0045] The specific steps for extracting the mixed solution with excess extractant and filtering to obtain the self-crosslinking compound are as follows:

[0046] The solid phase of the mixed solution is separated by vacuum distillation to obtain the mixed material;

[0047] The mixture was extracted with an excess of extractant and then filtered to obtain a self-crosslinking compound.

[0048] In this embodiment, when the nitrogen atom of thiopheneimidazole attacks the chloromethyl carbon atom in 1-(chloromethyl)-2-vinylbenzene, hydrogen chloride is generated. At this time, the alkaline substance can react with the hydrogen chloride to neutralize it, preventing the reaction system from being too acidic and affecting the reaction process. Vacuum distillation can separate the solid phase from the mixed solution, thereby removing the solvent and other materials from the liquid phase, resulting in a relatively pure mixed material.

[0049] Furthermore, the molar ratio of thiopheneimidazole to the crosslinking group preform is (3–6):11; and / or,

[0050] The molar ratio of thiopheneimidazole to the basic substance is (4–6):8; and / or,

[0051] Alkaline substances include at least one of potassium carbonate, ammonium carbonate, potassium hydroxide, cesium carbonate, and potassium tert-butoxide; and / or,

[0052] The extractant may include at least one of acetonitrile, N,N-dimethylformamide, dimethyl sulfoxide, and tetrahydrofuran.

[0053] In this embodiment, the molar ratio of thiopheneimidazole to the crosslinking group preform allows for sufficient reaction between the two or a slight excess of one material, thereby increasing the yield of the crosslinking compound. The molar ratio of thiopheneimidazole to the basic substance allows for sufficient reaction between the basic substance and the generated hydrogen chloride, thus preventing the reaction environment from becoming acidic.

[0054] It should be understood that the molar ratio of thiophene imidazole to the crosslinking group preform can be any value or a range formed by any two of the following: 3:11, 4:11, 5:11, and 6:11. Preferably, when the molar ratio is 5:11, the yield of the crosslinking compound is higher and the material utilization rate is higher. The molar ratio of thiophene imidazole to the basic substance can be any value or a range formed by any two of the following: 1:2, 5:8, and 6:8. Preferably, when the ratio is 5:8, the basic substance can react with the generated hydrogen chloride, thereby improving the material utilization rate.

[0055] Accordingly, the material of the film includes any of the self-crosslinking compounds in the above embodiments.

[0056] In this embodiment, since the material of the thin film includes the crosslinking compound of any of the above embodiments, when the thin film is formed on other thin films containing inorganic perovskite material, during the formation process, the self-crosslinking compound will form a three-dimensional network structure, and drive the metal cations in the inorganic perovskite material to be located in the three-dimensional network structure, thereby eliminating the residual stress and specific defects on the surface of the inorganic perovskite material, preventing non-radiative recombination in the thin film containing inorganic perovskite material, and thus improving the lifetime of the thin film containing inorganic perovskite material; on the other hand, the cations in the self-crosslinking compound can attract the halides in the inorganic perovskite material to fill their corresponding halide vacancies, thereby improving the external quantum efficiency of the thin film containing inorganic perovskite material.

[0057] Further, please refer to Figure 1 The thin film 10 includes a first film layer 11 and a second film layer 12 stacked sequentially. The first film layer 11 contains an inorganic perovskite material, and the material of the second film layer 12 includes a self-crosslinking compound.

[0058] The self-crosslinking compounds self-crosslink to form a three-dimensional network structure, and at least some of the metal cations in the inorganic perovskite material are located in the three-dimensional network structure.

[0059] In this embodiment, the thin film 10 is a composite structure. Because the self-crosslinking compound of the second film layer 12 can form a three-dimensional network structure and passivate the inorganic perovskite material contained in the first film layer 11, the electron and hole injection efficiency of the first film layer 11 is high, while the second film layer 12 has a high electron transport efficiency. In summary, the thin film 10 in this embodiment has a high overall current density (external quantum efficiency) and a long service life. At this time, the thin film 10 can be used as the light-emitting layer of the optoelectronic device.

[0060] Furthermore, the material of the second film layer 12 also includes at least one selected from benzothiophene, azobisisobutyronitrile, azobisisoheptanenitrile, benzoyl peroxide, and di-tert-butyl peroxide; and / or,

[0061] Inorganic perovskite materials include doped or undoped inorganic perovskite semiconductors or organic-inorganic hybrid perovskite semiconductors. The general structural formula of inorganic perovskite semiconductors is AMX3, where A is cesium, M includes one or more of lead, tin, copper, nickel, cadmium, manganese, cobalt, iron, chromium, ytterbium, and europium, and X is a halogen, including one or more of chlorine, bromine, and iodine. The general structural formula of organic-inorganic hybrid perovskite semiconductors is BM'X'3, where B includes CH3(CH2). n-2 NH3 or [NH3(CH2)] n [NH3], where n≥2, M' includes one or more of lead, tin, copper, nickel, cadmium, manganese, cobalt, iron, chromium, ytterbium, and europium, and X' is a halogen, including one or more of chlorine, bromine, and iodine.

[0062] In this embodiment, benzothiophene, azobisisobutyronitrile, azobisisoheptanenitrile, benzoyl peroxide, and di-tert-butyl peroxide can generate free radicals. These free radicals can attack the carbon-carbon double bonds of the first or second self-crosslinking groups in the self-crosslinking compound. For example, a benzothiophene free radical can abstract a hydrogen atom from the vinyl double bond in a VHD molecule (compound of formula 1), thereby generating a carbon-centered free radical on the VHD molecule. These free radicals can undergo coupling reactions, causing the VHD molecules to connect with each other and achieve self-crosslinking. Inorganic perovskite materials contain metal cations and have high current efficiency.

[0063] Accordingly, please refer to Figure 2 This application also provides an optoelectronic device 20, which includes a first electrode 100 and a second electrode 600 disposed opposite to each other;

[0064] The functional layer is located between the first electrode 100 and the second electrode 600, and the functional layer is the thin film 10 of any of the above embodiments.

[0065] In this embodiment, since the functional layer is the thin film 10 in the above embodiment, the first crosslinking group in the functional layer can self-crosslink with the second crosslinking group to form a three-dimensional mesh structure. The three-dimensional mesh structure can restrict and drive the metal ions in the inorganic perovskite material to arrange themselves in sequence, so that the metal ions can be restored to a certain extent to the normal coordination state. It can also eliminate the residual stress on the surface of the inorganic perovskite material. Therefore, the self-crosslinking compound in this embodiment can effectively eliminate the surface defects of the inorganic perovskite material. At the same time, since the nitrogen atom in the thiophene imidazole group in the self-crosslinking compound contains at least one positive charge, it can attract halides to fill the halide vacancies, thereby avoiding the halide vacancies from hindering electron or hole transport, and thus improving the external quantum efficiency and lifespan of the optoelectronic device 20. It should be understood that when the functional layer includes the first film layer 11 and the second film layer 12, it can serve as a light-emitting layer. When it only has the second film layer 12 (a single-layer thin film), it can serve as a crosslinking layer between the light-emitting layer and the second electrode 600.

[0066] Furthermore, the first electrode 100 is the anode, the second electrode 600 is the cathode, and 20 also includes an electron functional layer and a hole functional layer, with the hole functional layer located between the anode and the functional layer, and the electron functional layer located between the cathode and the functional layer.

[0067] In this embodiment, when 20 includes a hole functional layer, its hole injection and / or hole transport efficiency is improved, thus improving the current efficiency of the photodetector; similarly, when the photodetector includes an electronic functional layer, its electron injection and / or electron transport efficiency is improved, which also improves the current efficiency of the photodetector.

[0068] Further, the hole functional layer includes a hole injection layer 200 and / or a hole transport layer 300. The material of the hole injection layer 200 is selected from at least one of poly(3,4-vinyldioxythiophene):poly(styrenesulfonic acid), copper phthalocyanine, titanium phthalocyanine, 4,4',4'-tris(N-3-methylphenyl-N-phenylamino)triphenylamine, 4,4',4'-tris[2-naphthylphenylamino]triphenylamine, 2,3,5,6-tetrafluoro-7,7',8,8'-tetracyanodimethyl-p-benzoquinone, 2,3,6,7,10,11-hexacyano-1,4,5,8,9,12-hexaazabenzophenanthrene, transition metal oxides, or transition metal sulfide self-crosslinking compounds. The transition metal oxide is selected from at least one of NiOx, MoOx, WOx, CrOx, or CuOx. The transition metal sulfide self-crosslinking compound is selected from MoSx, MoSex, WSx, W At least one of Sex or CuSx; and / or, the material of the hole transport layer 300 is selected from poly(9,9-dioctylfluorene-CO-N-(4-butylphenyl)diphenylamine), 3-hexyl-substituted polythiophene, poly(9-vinylcarbazole), poly[bis(4-phenyl)(4-butylphenyl)amine], poly(N,N'-bis(4-butylphenyl)-N,N'-diphenyl-1,4-phenylenediamine-CO-9,9-dioctylfluorene), 4,4',4”-Tris(carbazole-9-yl)triphenylamine, 4,4'-Di(9-carbazole)biphenyl, N,N'-diphenyl-N,N'-di(3-methylphenyl)-1,1'-biphenyl-4,4'-diamine, N,N'-diphenyl-N,N'-(1-naphthyl)-1,1'-biphenyl-4,4'-diamine, poly(3,4-ethylenedioxythiophene):poly(styrenesulfonic acid), doped or undoped graphene, C 60 At least one of NiO, MoO3, WO3, V2O5, CrO3, CuO, or p-type gallium nitride; and / or,

[0069] The electronic functional layer includes an electron injection layer and / or an electron transport layer 400, wherein the materials of the electron transport layer 400 and the electron injection layer independently include at least one of inorganic materials and organic materials; the inorganic material is selected from one or more of the following: doped or undoped zinc oxide, barium oxide, aluminum oxide, titanium oxide, tin oxide, tantalum oxide, zirconium oxide, nickel oxide, lithium titanium oxide, zinc aluminum oxide, zinc manganese oxide, zinc tin oxide, zinc lithium oxide, indium tin oxide, cadmium sulfide, zinc sulfide, molybdenum sulfide, tungsten sulfide, copper sulfide, zinc tin sulfide, indium phosphide, gallium phosphide, copper indium sulfide, copper gallium sulfide, and barium titanate; the doped elements include aluminum and magnesium. One or more of lithium, manganese, yttrium, lanthanum, copper, nickel, zirconium, cerium, and gadolinium; organic materials including one or more of 4,6-bis(3,5-bis(pyridin-3-yl)phenyl)-2-methylpyrimidine, 2,9-dimethyl-4,7-biphenyl-1,10-o-diazaphenanthroline, 4,7-diphenyl-1,10-phenanthroline, 1,3,5-tris(1-phenyl-1H-benzimidazol-2-yl)benzene, 8-hydroxyquinoline aluminum, 8-hydroxyquinoline lithium, bis(2-methyl-8-hydroxyquinoline-N1,O8)-(1,1'-biphenyl-4-hydroxy)aluminum, and ion-conjugated polyelectrolytes, and / or,

[0070] The anode and cathode each independently include doped metal oxide electrodes, composite electrodes, graphene electrodes, carbon nanotube electrodes, elemental metal electrodes, or alloy electrodes. The materials for the doped metal oxide electrodes include one or more of the following: indium-doped tin oxide, zinc-doped tin oxide, fluorine-doped tin oxide, antimony-doped tin oxide, aluminum-doped zinc oxide, gallium-doped zinc oxide, indium-doped zinc oxide, magnesium-doped zinc oxide, aluminum-doped magnesium oxide, and cadmium-doped zinc oxide. The composite electrodes include AZO / Ag / AZO, AZO / APC / AZO, ITO / Ag / ITO, ITO / APC / ITO, IZO / Ag / IZO, IZO / APC / IZO, ZnO / Ag / ZnO, ZnO / APC / ZnO, and TiO2 / Ag / TZ. The materials for elemental metal electrodes include one or more of Ag, Ni, Pt, Au, Ir, Cu, Mo, Al, Ca, Mg, and Ba, and the materials for alloy electrodes include Au:Mg alloy electrodes or Ag:Mg alloy electrodes.

[0071] The average thickness of the anode is 30–40 nm; and / or,

[0072] The average thickness of the cathode is 30–40 μm; and / or,

[0073] The average thickness of the hole functional layer is 20–80 nm; and / or,

[0074] The average thickness of the electronic functional layer is 20–50 nm; and / or,

[0075] In the functional layer, the average thickness of the first film layer 11 is 20–30 nm; and / or,

[0076] In the functional layer, the average thickness of the second film layer 12 is 10–30 nm.

[0077] The average thickness range of the hole and electron functional layers ensures efficient transport and diffusion of holes and electrons, regulates performance characteristics such as emission color and brightness, and thus improves the current efficiency of the photodetector. The average thickness of the first and second electrodes shortens the charge transport path, reduces resistance loss, minimizes light obstruction, facilitates charge collection and light utilization, and enhances photoelectric conversion efficiency. The material selection for the first and second electrodes improves carrier mobility, while the material selection for the hole and electron functional layers improves hole / electron transport efficiency.

[0078] It should be understood that the average thickness of the first electrode can be any value or any two of the following: 30 nm, 32 nm, 34 nm, 36 nm, 38 nm, and 40 nm. The average thickness of the second electrode can be any value or any two of the following: 30 nm, 32 nm, 34 nm, 36 nm, 38 nm, and 40 nm. The average thickness of the hole functional layer can be any value or any two of the following: 20 nm, 25 nm, 30 nm, 35 nm, 40 nm, 45 nm, 50 nm, 55 nm, 60 nm, 65 nm, 70 nm, 75 nm, and 80 nm. The average thickness of the electron functional layer can be any value or any two of the following: 20 nm, 25 nm, 30 nm, 35 nm, 40 nm, 45 nm, and 50 nm. The average thickness of the second electrode is 30–40 nm. The average thickness of the first film layer 11 can be any value or any two values ​​from 20nm, 21nm, 22nm, 23nm, 24nm, 25nm, 26nm, 27nm, 28nm, 29nm, and 30nm. The thickness of the second film layer 12 can be any value or any two values ​​from 10nm, 11nm, 12nm, 13nm, 14nm, 15nm, 16nm, 17nm, 18nm, 19nm, 20nm, 21nm, 22nm, 23nm, 24nm, 25nm, 26nm, 27nm, 28nm, 29nm, and 30nm.

[0079] Accordingly, this application also provides a display device, which includes the optoelectronic device 20 of any of the above embodiments.

[0080] In this embodiment, because the first crosslinking group in the light-emitting layer of the display device can self-crosslink with the second crosslinking group to form a three-dimensional mesh structure; at the same time, because the nitrogen atom in the thiophene imidazole group in the self-crosslinking compound contains at least one positive charge, as per the principle of the above optoelectronic device 20 embodiment, the external quantum efficiency and lifespan of the display device are high.

[0081] The present application will be specifically described below through specific embodiments. The following embodiments are only some embodiments of the present application and are not intended to limit the present application.

[0082] Example 1

[0083] Preparation of cross-linked compounds. 5 mmol of thiopheneimidazole, 11 mmol of p-chlorostyrene, and 8 mmol of K₂CO₃ were added to 50 mL of CH₃CN to form a mixed solution.

[0084] The mixed solution was refluxed and stirred, then distilled under reduced pressure to remove the liquid, and then extracted with excess CH2Cl2. The mixture was then filtered to obtain the self-crosslinking compound of formula 1.

[0085] Example 2

[0086] This embodiment is basically the same as Example 1, except that p-chlorostyrene benzene is replaced with 1-allyl-4-chlorobenzene to prepare the self-crosslinking compound Formula 2.

[0087] Example 3

[0088] This embodiment is basically the same as Example 1, except that p-chlorostyrene benzene is replaced with 1-acryloyloxy-4-chlorobenzene to prepare the self-crosslinking compound Formula 3.

[0089] Example 4

[0090] This embodiment is basically the same as Example 1, except that p-chlorostyrene is replaced with 1-acryloyl-4-chlorobenzene to prepare the self-crosslinking compound of formula 4.

[0091] Example 5

[0092] This embodiment is basically the same as Example 1, except that p-chlorostyrene is replaced with 1-vinyloxyacyl-4-chlorobenzene to prepare the self-crosslinking compound Formula 5.

[0093] The 1H NMR spectra of compounds of formulas 1 to 5 are shown in Table 1.

[0094] Table 1:

[0095]

[0096] Thin Film Example 1

[0097] This embodiment provides a thin film and its preparation method, the preparation method is as follows:

[0098] Step 1, Preparation of the first film layer. A substrate is provided, a CsPbBr3 quantum dot solution is coated on the substrate, and then the substrate is transferred to a VCD device for drying. Then, it is annealed for 10 minutes using a 100°C hot stage to form a 30nm thick first film layer. The material of the first film layer is CsPbBr3.

[0099] Step 2, preparing the second film layer. The ethanol solution of compound 1 is subjected to a first ultraviolet light irradiation treatment, causing self-crosslinking of the compound 1 in the ethanol solution. The ethanol solution of compound 1 is then coated onto the first film layer to form a second film layer liquid film. An accelerator solution, including isopropanol and benzothiophene, is then added dropwise to the second film layer liquid film. The second film layer liquid film is subjected to a second ultraviolet light irradiation treatment to obtain the second film layer, thus forming a thin film.

[0100] Thin Film Example 2

[0101] This film example is basically the same as film example 1, except that the compound of formula 1 in step 2 is replaced with the self-crosslinking compound of formula 3.

[0102] Thin Film Example 3

[0103] This thin film embodiment is basically the same as thin film embodiment 1, except that the material of the first film layer in step 1 is replaced with a solution and CsPbCl3.

[0104] Thin Film Example 4

[0105] This thin film embodiment is basically the same as thin film embodiment 1, except that the first ultraviolet light irradiation treatment step in step 2 is omitted.

[0106] Thin Film Example 5

[0107] This film example is basically the same as film example 1, except that the step of adding the accelerator in step 2 is omitted.

[0108] Thin Film Example 6

[0109] This film example is basically the same as film example 1, except that: benzothiophene in the accelerator in step 2 is replaced with azobisisobutyronitrile.

[0110] Comparative Example 1

[0111] This thin film embodiment is basically the same as thin film embodiment 1, except that step 2 is omitted.

[0112] Comparative Example 2

[0113] This film example is basically the same as film example 1, except that the compound of formula 1 in step 1 is replaced with polyacrylonitrile.

[0114] Test Result Analysis: The thin films prepared in Examples 1-6 and Comparative Examples 1-2 were used as light-emitting layers to prepare EOD devices (single-electron devices, with the structure of ITO / light-emitting layer / cathode). The electron transport efficiency and electron injection efficiency were tested respectively, and the test results were plotted as JV curves.

[0115] In the JV curve, the current density gradually increases with the increase of voltage. The current density of the EOD device corresponding to Example A and Comparative Examples A to C is recorded when the output voltage is 10V, forming Table 2.

[0116] Table 2:

[0117]

[0118]

[0119] As can be seen from Thin Film Example 1 and Comparative Examples 1-2, adding either Compound 1 or polyacrylonitrile can improve the current efficiency of the thin film. However, when Compound 1 is used, the improvement in current efficiency of the thin film is greater than that of existing polymer passivating agents such as polyacrylonitrile.

[0120] As can be seen from Thin Film Examples 1-3 and Comparative Example 2, the types of inorganic perovskite materials or self-crosslinking compounds provided in this application can ensure that the thin film has higher current efficiency than the prior art.

[0121] As can be seen from Thin Film Examples 1 and 4, irradiating a solution containing a crosslinking compound with ultraviolet light can promote the self-crosslinking of the crosslinking compound to a certain extent, thereby promoting the crosslinking compound to eliminate surface defects of inorganic perovskite materials and thus improving the current efficiency of the thin film.

[0122] As can be seen from Thin Film Examples 1 and 5-6, the types of promoters provided in this application can all improve the self-crosslinking efficiency of the second film layer on the first film layer, thereby promoting the crosslinking compound to eliminate surface defects of the inorganic perovskite material, thereby improving the current efficiency of the film.

[0123] Optoelectronic device Example 1

[0124] This application provides a method for fabricating an optoelectronic device, the method of which is as follows:

[0125] Step 1, Anode preparation. A substrate with ITO glass is provided. The ITO glass is cleaned and further organic contaminants on the surface of the ITO glass are removed using an ultraviolet ozone cleaner to improve the wettability of the ITO surface. Then, the preform is placed on a 230°C hot plate for drying to form a 50nm thick anode.

[0126] Step 2, preparation of hole transport layer. A hole transport layer liquid film is formed on the anode, the substrate is transferred to a VCD device (high vacuum circulating drying equipment) for drying, and then the substrate is placed on a 230°C hot stage for 30 min followed by annealing to form a 50 nm thick hole transport layer;

[0127] Step 3, Preparation of the luminescent layer. A CsPbBr3 quantum dot solution is coated onto the hole transport layer, and then transferred to a VCD device for drying. It is then annealed at 100°C for 10 minutes to form a 30nm thick luminescent layer. The material of the luminescent layer is CsPbBr3.

[0128] Step 4: Prepare the cross-linked layer.

[0129] An ethanol solution of Formula 1 is subjected to a first ultraviolet light irradiation treatment to induce self-crosslinking of Formula 1 (VHD) in the ethanol solution of Formula 1. An ethanol solution of Formula 1 is then coated onto the light-emitting layer to form a crosslinked liquid film. An accelerator solution, comprising isopropanol and benzothiophene, is then added dropwise to the crosslinked liquid film. The crosslinked liquid film is then subjected to a second ultraviolet light irradiation treatment to form a crosslinked layer.

[0130] Step 5: Prepare the electron transport layer. An electron transport layer liquid film is formed on the above crosslinked layer. The substrate is transferred to a VCD device (high vacuum cyclic drying equipment) for drying, and then placed on a 230°C hot stage for annealing for 30 minutes to form a 50nm thick electron transport layer.

[0131] Step 6: Prepare the electron injection layer. Print the electron injection layer solution obtained in Step 2 onto the electron transport layer to form a 5 nm thick electron injection layer film.

[0132] Step 7, Cathode fabrication. The substrate is transferred to a vacuum evaporation machine, and Al is evaporated onto the optoelectronic device to form a 70 nm thick aluminum cathode.

[0133] Optoelectronic device Example 2

[0134] This optoelectronic device embodiment is basically the same as optoelectronic device embodiment 1, except that the compound of formula 1 in step 4 is replaced with the self-crosslinking compound of formula 3.

[0135] Optoelectronic device Example 3

[0136] This optoelectronic device embodiment is basically the same as optoelectronic device embodiment 1, except that the material of the first film layer in step 3 is replaced with a solution and CsPbCl3.

[0137] Optoelectronic device Example 4

[0138] This optoelectronic device embodiment is basically the same as optoelectronic device embodiment 1, except that the first ultraviolet light irradiation process in step 4 is omitted.

[0139] Optoelectronic device Example 5

[0140] This optoelectronic device embodiment is basically the same as optoelectronic device embodiment 1, except that the step of adding the promoter in step 4 is omitted.

[0141] Optoelectronic device Example 6

[0142] This optoelectronic device embodiment is basically the same as optoelectronic device embodiment 1, except that: benzothiophene in the accelerator in step 4 is replaced with azobisisobutyronitrile.

[0143] Comparative Example 1

[0144] This optoelectronic device embodiment is basically the same as optoelectronic device embodiment 1, except that step 4 is omitted.

[0145] Comparative Example 2

[0146] This optoelectronic device embodiment is basically the same as optoelectronic device embodiment 1, except that the compound of formula 1 in step 4 is replaced with polyacrylonitrile.

[0147] Test Result Analysis: The external quantum efficiency and lifespan of the optoelectronic devices in Examples 1-6 and Comparative Examples 1 and 2 were tested. The external quantum efficiency was tested using an IVL device. The voltage at a current density of 10 mA / cm2 (J10) was used as the driving voltage (gate-on voltage), and the external quantum efficiency at a brightness of 1000 cd / m2 was used as the external quantum efficiency.

[0148] The lifespan test method was as follows: Under constant current (2mA) drive, a 128-channel QLED lifespan test system was used to perform electroluminescence lifetime analysis on each optoelectronic device. The time (T95,h) required for each optoelectronic device to decay from its maximum brightness to 95% was recorded. The time (T95@1000nit,h) required for each optoelectronic device to decay from 100% brightness to 95% brightness at 1000nit was calculated using the decay fitting formula. The test results are shown in Table 3.

[0149] Table 3:

[0150] type EQE (%) at 1000 cd / m2 L(cd / m2)at4V Optoelectronic device Example 1 15.8 18020 Optoelectronic device Example 2 15.6 17310 Optoelectronic device Example 3 15.5 17880 Optoelectronic device Example 4 12.8 13560 Optoelectronic device Example 5 13 13980 Optoelectronic device Example 6 15.4 17860 Comparative Example 1 8.6 6570 Comparative Example 2 12.5 13300

[0151] As shown in Table 3:

[0152] As can be seen from Example 1 and Comparative Examples 1 and 2, the addition of compound 1 or polyacrylonitrile can improve the current efficiency and lifespan of optoelectronic devices. The improvement in current efficiency and lifespan of optoelectronic devices after adding compound 1 is greater than that of existing polymer passivating agents such as polyacrylonitrile.

[0153] As can be seen from Examples 1-3 and Comparative Example 2 of optoelectronic devices, the types of inorganic perovskite materials or self-crosslinking compounds provided in this application can ensure that the optoelectronic devices have higher current efficiency and service life compared with the prior art.

[0154] As can be seen from Examples 1 and 4 of optoelectronic devices, irradiating a solution containing a crosslinking compound with ultraviolet light can promote the self-crosslinking of the crosslinking compound to a certain extent, thereby promoting the crosslinking compound to eliminate surface defects of inorganic perovskite materials, thus improving the current efficiency and service life of optoelectronic devices.

[0155] As can be seen from Examples 1 and 5-6 of optoelectronic devices, the types of promoters provided in this application can all improve the self-crosslinking efficiency of the crosslinked layer on the light-emitting layer, thereby promoting the crosslinked compound to eliminate surface defects of inorganic perovskite materials, thereby improving the current efficiency and service life of optoelectronic devices.

[0156] The optoelectronic devices, fabrication methods, and display devices provided in the embodiments of this application have been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of this application. The descriptions of the above embodiments are only for the purpose of helping to understand the methods and core ideas of this application. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of this application. Therefore, the content of this specification should not be construed as a limitation of this application.

Claims

1. A self-crosslinking compound, characterized by, The general structural formula of the self-crosslinking compound is: Each of A1, A2, and A3 is independently selected from at least one of substituted or unsubstituted C2-C10 alkenyl, substituted or unsubstituted C2-C10 enoyl, substituted or unsubstituted C2-C10 enoyloxycarbonyl, and substituted or unsubstituted C2-C10 enoyloxy. When substituted, each of the substituents is independently selected from one or more combinations of hydrogen, deuterium, halogen, amino, hydroxyl, carboxyl, nitro, sulfonic acid, mercapto, cyano, C1-C30 alkyl, aryl with 6-30 ring atoms, and heteroaryl with 5-30 ring atoms. X - Selected from F - Cl - ,Br - I - I3 - BF4 - PF6 - SbF6 - AsF6 - NO2 - NO3 - SCN - CN - HCO3 - HSO4 - H2PO4 - HCOO - CH3COO - CF3COO - CF3SO3 - C4F9SO3 - CF3(C6H4)SO3 - CH3(C6H4)SO3 - (CF3SO2)2N - FeCl4 - (CN)2N - and 7,7-dimethyl-2-oxobicyclo[ 2.2.1] One or more of heptane-1-methanesulfonate.

2. The self-crosslinking compound according to claim 1, characterized by A1 and A3 are each independently selected from at least one of the following structural formulas: Wherein, n is selected from an integer from 0 to 2, and R1, R2, R3, R4, R5, R6, R7, R8, R9, R11 and R12 are each independently selected from one or more combinations of hydrogen, deuterium, halogen, amino, hydroxyl, carboxyl, nitro, sulfonic acid, mercapto, cyano, C1 to C30 alkyl, aryl with 6 to 30 ring atoms, and heteroaryl with 5 to 30 ring atoms.

3. The self-crosslinking compound according to claim 2, characterized in that The self-crosslinking compound is selected from at least one of the structural formulas shown in Formulas 1 to 5:

4. A film, characterized by, The material of the film includes any one of the self-crosslinking compounds according to claims 1 to 3.

5. The film of claim 4, wherein The thin film includes a first film layer and a second film layer stacked sequentially, wherein the first film layer contains an inorganic perovskite material and the material of the second film layer includes the self-crosslinking compound; The self-crosslinking compounds self-crosslink to form a three-dimensional network structure, and at least a portion of the metal cations in the inorganic perovskite material are located in the three-dimensional network structure.

6. The film of claim 5, wherein The material of the second film layer further includes at least one selected from benzothiophene, azobisisobutyronitrile, azobisisoheptanenitrile, benzoyl peroxide, and di-tert-butyl peroxide; and / or, The inorganic perovskite material includes doped or undoped inorganic perovskite semiconductors or organic-inorganic hybrid perovskite semiconductors. The inorganic perovskite semiconductor has the general structural formula AMX3, where A is cesium, M includes one or more of lead, tin, copper, nickel, cadmium, manganese, cobalt, iron, chromium, ytterbium, and europium, and X is a halogen, including one or more of chlorine, bromine, and iodine. The organic-inorganic hybrid perovskite semiconductor has the general structural formula BM'X'3, where B includes CH3(CH2). n-2 NH3 or [NH3(CH2)] n [NH3], where n≥2, M' includes one or more of lead, tin, copper, nickel, cadmium, manganese, cobalt, iron, chromium, ytterbium, and europium, and X' is a halogen, including one or more of chlorine, bromine, and iodine.

7. An optoelectronic device, characterized in that The optoelectronic device includes a first electrode, a functional layer, and a second electrode stacked sequentially. The functional layer is located between the first electrode and the second electrode, and the functional layer is the thin film according to any one of claims 4 to 6.

8. The optoelectronic device of claim 7, wherein, The first electrode is the anode, the second electrode is the cathode, and the optoelectronic device further includes an electronic functional layer and a hole functional layer. The hole functional layer is located between the anode and the functional layer, and the electronic functional layer is located between the cathode and the functional layer.

9. The optoelectronic device of claim 8, wherein, The hole functional layer includes a hole injection layer and / or a hole transport layer. The hole injection layer is made of a material selected from at least one of poly(3,4-vinyldioxythiophene):poly(styrenesulfonic acid), copper phthalocyanine, titanium phthalocyanine, 4,4',4'-tris(N-3-methylphenyl-N-phenylamino)triphenylamine, 4,4',4'-tris[2-naphthylphenylamino]triphenylamine, 2,3,5,6-tetrafluoro-7,7',8,8'-tetracyanodimethyl-p-benzoquinone, 2,3,6,7,10,11-hexacyano-1,4,5,8,9,12-hexaazabenzophenanthrene, transition metal oxides, or transition metal sulfide self-crosslinking compounds. The transition metal oxide is selected from at least one of NiOx, MoOx, WOx, CrOx, or CuOx. The transition metal sulfide self-crosslinking compound is selected from MoSx, MoSex, WSx, and WSex. Or at least one of CuSx; and / or, the material of the hole transport layer is selected from poly(9,9-dioctylfluorene-CO-N-(4-butylphenyl)diphenylamine), 3-hexyl-substituted polythiophene, poly(9-vinylcarbazole), poly[bis(4-phenyl)(4-butylphenyl)amine], poly(N,N'-bis(4-butylphenyl)-N,N'-diphenyl-1,4-phenylenediamine-CO-9,9-dioctylfluorene), 4, 4',4”-Tris(carbazole-9-yl)triphenylamine, 4,4'-Di(9-carbazole)biphenyl, N,N'-diphenyl-N,N'-di(3-methylphenyl)-1,1'-biphenyl-4,4'-diamine, N,N'-diphenyl-N,N'-(1-naphthyl)-1,1'-biphenyl-4,4'-diamine, poly(3,4-ethylenedioxythiophene):poly(styrenesulfonic acid), doped or undoped graphene, C 60 At least one of NiO, MoO3, WO3, V2O5, CrO3, CuO, or p-type gallium nitride; and / or, The electronic functional layer includes an electron injection layer and / or an electron transport layer, wherein the materials of the electron transport layer and the electron injection layer independently include at least one of inorganic materials and organic materials; the inorganic material is selected from one or more of the following: doped or undoped zinc oxide, barium oxide, aluminum oxide, titanium oxide, tin oxide, tantalum oxide, zirconium oxide, nickel oxide, lithium titanium oxide, zinc aluminum oxide, zinc manganese oxide, zinc tin oxide, zinc lithium oxide, indium tin oxide, cadmium sulfide, zinc sulfide, molybdenum sulfide, tungsten sulfide, copper sulfide, zinc tin sulfide, indium phosphide, gallium phosphide, copper indium sulfide, copper gallium sulfide, and barium titanate; the doped elements include aluminum and magnesium. One or more of lithium, manganese, yttrium, lanthanum, copper, nickel, zirconium, cerium, and gadolinium, wherein the organic material comprises one or more of 4,6-bis(3,5-bis(pyridin-3-yl)phenyl)-2-methylpyrimidine, 2,9-dimethyl-4,7-biphenyl-1,10-o-diazaphenanthroline, 4,7-diphenyl-1,10-phenanthroline, 1,3,5-tris(1-phenyl-1H-benzimidazol-2-yl)benzene, 8-hydroxyquinoline aluminum, 8-hydroxyquinoline lithium, bis(2-methyl-8-hydroxyquinoline-N1,O8)-(1,1'-biphenyl-4-hydroxy)aluminum, and ion-conjugated polyelectrolytes, and / or, The anode and the cathode each independently comprise a doped metal oxide electrode, a composite electrode, a graphene electrode, a carbon nanotube electrode, a metal element electrode, or an alloy electrode. The doped metal oxide electrode is made of one or more of the following materials: indium-doped tin oxide, zinc-doped tin oxide, fluorine-doped tin oxide, antimony-doped tin oxide, aluminum-doped zinc oxide, gallium-doped zinc oxide, indium-doped zinc oxide, magnesium-doped zinc oxide, aluminum-doped magnesium oxide, and cadmium-doped zinc oxide. The composite electrode comprises AZO / Ag / AZO, AZO / APC / AZO, ITO / Ag / ITO, ITO / APC / ITO, IZO / Ag / IZO, and IZO / Ag / IZO. PC / IZO, ZnO / Ag / ZnO, ZnO / APC / ZnO, TiO2 / Ag / TiO2, TiO2 / APC / TiO2, ZnS / Ag / ZnS, ZnS / Al / ZnS, Ca / Al, LiF / Ca, LiF / Al, BaF2 / Al, CsF / Al, CaCO3 / Al, or BaF2 / Ca / Al, wherein the material of the elemental metal electrode includes one or more of Ag, Ni, Pt, Au, Ir, Cu, Mo, Al, Ca, Mg, and Ba, and the alloy electrode includes an Au:Mg alloy electrode or an Ag:Mg alloy electrode; and / or, The average thickness of the anode is 30–40 nm; and / or, The average thickness of the cathode is 30–40 nm; and / or, The average thickness of the hole functional layer is 20–80 nm; and / or, The average thickness of the electronic functional layer is 20–50 nm; and / or, In the functional layer, the average thickness of the first film layer is 20–30 nm; and / or, In the functional layer, the average thickness of the second film layer is 10–30 nm.

10. A display device, characterized by comprising: The display device includes the optoelectronic device described in any one of claims 7 to 9.

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