Star-shaped self-assembled hole transport layer material, preparation method and application thereof

Abstract

The application belongs to the technical field of photoelectric materials, and relates to a star-shaped self-assembled hole transport layer material, a preparation method and application thereof. The star-shaped self-assembled hole transport layer material comprises a star-shaped organic compound with a structure shown in general formula (1). The star-shaped organic compound takes an aromatic three-site group as a core, adopts a star-shaped bridging unit, and connects three benzo carbazole phosphate units. The star-shaped organic compound as a hole transport layer material of a photoelectric functional device is beneficial to the improvement of device efficiency and stability, and provides a reliable foundation for the industrialization development of perovskite solar cells and organic solar cells.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of optoelectronic materials, and relates to a star-shaped self-assembled hole transport layer material, a preparation method and application thereof. BACKGROUND

[0002] The state has introduced relevant policies, and the implementation of these policies will effectively promote the development of global clean energy and provide a reference for countries to achieve carbon neutralization. Through multilateral cooperation and technological innovation, China actively promotes global sustainable development, which not only meets the national interests, but also has a profound impact on global climate governance.

[0003] To accelerate the realization of the carbon neutralization and carbon peak goals, scientific researchers will focus on the transformation and emission reduction of the power industry. As one of the main sources of carbon dioxide emissions, the carbon emissions of the power industry account for more than one-third of the total carbon dioxide emissions from the combustion of fossil fuels worldwide, and in China, the carbon dioxide emissions of the power sector account for more than 40% of the total emissions. In order to achieve the dual goals of carbon peak and carbon neutralization, the transformation of the power industry is crucial, and the development of clean energy technologies such as photovoltaic power generation and wind power has become an inevitable trend.

[0004] In the field of solar cells, the research and application of perovskite solar cells have important strategic significance in achieving global carbon peak and carbon neutralization. Compared with traditional silicon-based solar cells, perovskite solar cells exhibit significant advantages, including higher photoelectric conversion efficiency (PCE) and lower manufacturing cost. The high photoelectric conversion efficiency and low production cost of this new battery technology not only improve the economic efficiency of solar power generation, but also provide feasibility for its large-scale promotion. In particular, perovskite solar cells with an inverted structure are considered one of the mainstream commercialization routes for this emerging photovoltaic technology due to their competitive photoelectric conversion efficiency, good stability, and compatibility with tandem solar cells. Currently, thanks to the progress of hole selection layers and passivation strategies, the photoelectric conversion efficiency of such cells has exceeded 25%. In particular, high-efficiency inverted perovskite solar cells based on self-assembled hole transport layer (HTL) materials have been widely used due to their suitable energy level matching and lower non-radiative recombination loss.

[0005] However, the uneven distribution of commonly used self-assembled films on the substrate and the poor surface wettability of perovskite precursors pose challenges to the direct deposition of high-quality perovskite thin films on the self-assembled hole transport layer material. These problems not only reduce the manufacturing yield, but also can cause undesirable interface losses at the interface between the perovskite layer and the hole transport layer, especially when manufacturing large-area devices. To further develop the technology of organic solar cells and perovskite solar cells, improve the efficiency and stability of the devices, it is particularly crucial to develop new high-efficiency hole transport materials. The improvement of these materials will help to overcome the defects in the prior art, improve the overall performance of perovskite solar cells, and promote their widespread application around the world. SUMMARY

[0006] To solve the above problems existing in the prior art, the purpose of the present application is to provide a star-shaped self-assembled hole transport layer material, a preparation method and applications thereof, so as to overcome the shortcomings of the prior art.

[0007] One object of the present application is achieved by the following technical solutions:

[0008] A star-shaped self-assembled hole transport layer material, comprising a star-shaped organic compound having a structure represented by general formula (1):

[0009]

[0010] In formula (1), Ar is a structure comprising an aromatic group; linker is a structure comprising one or more of C1-C10 straight-chain alkyl, phenyl, biphenyl.

[0011] Preferably, the Ar is one of the structures represented by general formula (2):

[0012]

[0013] In the present application, represents a connecting end.

[0014] Preferably, the linker is one of the structures represented by general formula (3):

[0015]

[0016] wherein n, a, b, x, y are independently natural numbers in 0-9.

[0017] The second object of the present application is achieved by the following technical solutions:

[0018] A preparation method of a star-shaped self-assembled hole transport layer material, comprising the following steps:

[0019] S1, under inert gas protection, 10-halogen-7(H)-benzo[c]carbazole is dissolved in organic solvent, then halogen-terminated linker (X-linker-X) is added, heated to reflux under catalytic and alkaline environment, extracted, column chromatography to obtain solid product;

[0020] S2, the product of step S1 is mixed with triethyl phosphite, heated to reflux under inert gas protection to carry out Arbuzal reaction, column chromatography to obtain benzocarbazole derivative with phosphate group;

[0021] S3, under inert gas protection, benzocarbazole derivative with phosphate group is dissolved in organic solvent, then 3-trimethyl tin substituted Ar monomer or 3-boronate substituted Ar monomer is added, coupling reaction is carried out under the action of metal catalyst, extracted, column chromatography to obtain product;

[0022] S4, under inert gas protection, the product of step S3 is dissolved in solvent, trimethyl bromosilane is added, then alcohol is used for quenching, and poor solvent is used for precipitation, the precipitated product is extracted and dried to obtain star-shaped self-assembled hole transport layer material.

[0023] The reaction equations of steps S1 and S2 are as follows:

[0024]

[0025] X is halogen, preferably Br, Cl or F.

[0026] The reaction equations of steps S3 and S4 are as follows:

[0027]

[0028] In step S1 of the preparation method, the organic solvent is preferably one or more of N,N-dimethylformamide (DMF), tetrahydrofuran (THF), toluene (TOL), N-methylpyrrolidone (NMP), and the like. The catalyst includes a phase transfer catalyst, and further preferably, the catalyst includes a phase transfer catalyst and a metal catalyst. The phase transfer catalyst is preferably one or more of tetrabutylammonium bromide (TBAB), benzyltriethylammonium chloride (TEBAC), hexadecyltrimethylammonium bromide (HTMAB), and the like; and the metal catalyst is preferably one or more of palladium acetate, palladium tris(triphenylphosphine), palladium bis(tri-tert-butylphosphine), tris(dibenzylideneacetone)dipalladium, (2-dicyclohexylphosphino-2',4',6'-triisopropyl-1,1'-biphenyl)(2'-amino-1,1'-biphenyl-2-yl)palladium (XPhos-Pd-G3), and the like. The basic environment is preferably achieved by adding one or more of potassium carbonate, sodium hydroxide, potassium hydroxide, cesium carbonate, triethylamine, and the like. The molar ratio of 10-halogen-7(H)-benzo[c]carbazole to the linker with a halogen group end is preferably 1:5 to 30. The molar ratio of the catalyst to 10-halogen-7(H)-benzo[c]carbazole is preferably 1 to 3:1. The heating reflux reaction temperature is preferably 60 to 100°C, and the reaction time is preferably 3 to 24 h.

[0029] In step S2 of the preparation method, the molar ratio of the product of step S1 to triethyl phosphite is preferably 1:5 to 25. The heating reflux temperature is preferably 140 to 200°C, and the time is preferably 5 to 48 h. Further preferably, step S2 is performed under a metal catalyst to perform the Arbuzal reaction.

[0030] In step S3 of the preparation method, the molar ratio of the Ar monomer substituted with 3 trimethyltin or the Ar monomer substituted with 3 borate to the benzo[c]carbazole derivative with a phosphate group is preferably 1:3 to 4. The coupling reaction is performed under heating reflux, the heating temperature is preferably 80 to 130°C, and the reaction time is preferably 2 to 40 h.

[0031] In step S4 of the preparation method, the molar ratio of the product of step S3 to trimethylsilyl bromide is preferably 1:5 to 30. The solvent is preferably one or more of dichloromethane, dioxane, dimethyl sulfoxide (DMSO), and the like. The reaction is preferably performed at 10 to 40°C, and the reaction time is preferably 5 to 40 h.

[0032] The inert atmosphere herein includes one or more of nitrogen, argon.

[0033] A third object of the present application is achieved by the following technical solution:

[0034] The application of a star-shaped self-assembled hole transport layer material in preparing a photoelectric functional device, which is an organic solar cell or a perovskite solar cell.

[0035] Preferably, the hole transport layer of the photoelectric functional device comprises the star-shaped self-assembled hole transport layer material.

[0036] Preferably, when the photoelectric functional device is an organic solar cell, the device structure comprises a cathode layer, an electron transport layer, a photoactive layer, a hole transport layer and an anode layer, and the hole transport layer comprises the star-shaped self-assembled hole transport layer material.

[0037] Preferably, when the photoelectric functional device is a perovskite solar cell, the device structure comprises a cathode layer, a hole blocking layer, an electron transport layer, a perovskite active layer, a hole transport layer and an anode layer, and the hole transport layer comprises the star-shaped self-assembled hole transport layer material.

[0038] Compared with the prior art, the application has the following beneficial effects:

[0039] 1. The application provides a novel star-shaped self-assembled hole transport layer material, which has a unique structure, takes a three-site group with aromaticity as a core, adopts a star-shaped bridging unit, and connects three phosphonic benzocarbazole units.

[0040] 2. The application also provides a preparation method of the novel star-shaped self-assembled hole transport layer material, and the whole preparation method is relatively simple, the synthesis process has a low cost, and is beneficial to large-scale production and application.

[0041] 3. The star-shaped self-assembled hole transport layer material provided by the application has excellent hole transport performance due to the special structure design, and compared with a small-molecule phosphonic benzocarbazole SAM, the star-shaped organic compound has a larger pi conjugated structure, and the larger conjugated system is also more conducive to the transmission of holes between molecules and the blocking of electrons. Compared with an ordinary single-layer material, the three-legged star-shaped molecule has a tendency of face-to-face stacking, thereby enhancing hole collection and reducing interface charge recombination. In addition, the material can form a complete coverage on a substrate surface and stably self-assemble due to the presence of multiple phosphonic anchor groups, thereby improving the wettability of the material on the substrate. The star-shaped molecule exhibits excellent properties in terms of conductivity and wettability on a conductive substrate. The interaction between the star-shaped molecule and the transparent conductive substrate is stronger, and the migration of the molecule is not easy, and finally the efficiency and stability of the battery device are improved, thereby providing a reliable foundation for the industrialized development of perovskite solar cells and organic solar cells. BRIEF DESCRIPTION OF DRAWINGS

[0042] Figure 1 is a structural schematic diagram of a perovskite solar cell device in Example 7;

[0043] Figure 2 is a structural schematic diagram of the organic solar cell device in Example 8;

[0044] Figure 3 is a structural schematic diagram of C60, BCP, and PDINN. DETAILED DESCRIPTION

[0045] The technical solutions of the present application are further described and explained below by means of specific examples and drawings. It should be understood that the specific examples described herein are only used to help understand the present application and are not used to limit the present application. The drawings used herein are only used to better illustrate the disclosed content of the present application and do not limit the scope of protection. If not specifically stated, the raw materials used in the examples of the present application are all commonly used raw materials in the art, and the methods used in the examples are all conventional methods in the art.

[0046] In the following examples, the room temperature is 25°C.

[0047] Example 1: Synthesis of star-shaped organic compound WuJ-1

[0048] S1, two-mouth bottles were added with tetrahydrofuran (THF) 20 ml. Phase transfer catalyst tetrabutylammonium bromide (TBAB) (0.644 g, 2 mmol), cesium carbonate (0.65 g, 2 mmol), 10-bromo-7(H)-benzo[c]carbazole (0.592 g, 2 mmol), and 1,4-dibromobutane (4.32 g, 20 mmol) were added. The reaction was heated under reflux protection with nitrogen, the temperature was 80°C, and the reaction time was 6 h. After the reaction was completed, it was extracted with ethyl acetate. The product was obtained after column chromatography with a mixed solvent of petroleum ether and ethyl acetate, and finally 0.767 g of light yellow solid was obtained with a yield of 89%.

[0049] S2, two-mouth bottles were added with the product of step S1 (0.646, 1.5 mmol) and triethyl phosphite (5 g, 30 mmol). The reaction was heated under reflux protection with nitrogen, the temperature was 180°C, and the time was 24 h. After the reaction was completed, the product was obtained after column chromatography with a mixed solvent of petroleum ether and ethyl acetate, and finally 0.715 g of light yellow oil was obtained with a yield of 98%.

[0050] S3, two-mouth flask, add the product of S2 (0.487g, 1mmol), tetrakis triphenylphosphine palladium (50mg), potassium carbonate (0.276g, 2mmol) and 20ml N,N-dimethylformamide (DMF), stir until the solution is clear under nitrogen protection, then add 1,3,5-benzene triborate (0.137g, 0.3mmol) at room temperature, heat to reflux for 24h. After the reaction is completed, extract with ethyl acetate. Column chromatography with methanol and ethyl acetate mixed solvent to obtain the product, finally get a yellow solid WuJ-1-POET 0.32g, yield 82%.

[0051] S4, the product obtained in the above reaction 0.3g is dissolved in 15ml of dichloromethane, 2ml of trimethylsilyl bromide is added dropwise under nitrogen protection, and stirred at room temperature for 12h. After the reaction is completed, 5ml of methanol is added to the system to remove excess trimethylsilyl bromide, and stirred for 3h. Concentrate the solution under reduced pressure, then add enough deionized water to settle, and the precipitated product is filtered and dried to obtain a yellow solid WuJ-1 0.182g, yield 70%.

[0052] The reaction equation of step S3 is as follows:

[0053]

[0054] The structural formula of the final product is as follows:

[0055]

[0056] Example 2: Synthesis of star-shaped organic compound WuJ-2

[0057] S1, two-mouth flask, add N,N-dimethylformamide (DMF) 20ml. Add phase transfer catalyst tetrabutylammonium bromide (TBAB) (0.644g, 2mmol), cesium carbonate (0.65g, 2mmol), 10-bromo-7(H)-benzo[c]carbazole (0.592g, 2mmol) and 1,4-dibromobenzene (7g, 30mmol). Heat to reflux under nitrogen protection, temperature is 80℃, reaction time is 6h. After the reaction is completed, extract with ethyl acetate. Column chromatography with petroleum ether and ethyl acetate mixed solvent to obtain the product, finally get a yellow solid 0.695g, yield 77%.

[0058] S2, two-mouth flask, add the product of step S1 (0.676g, 1.5mmol) and triethyl phosphite (6.7g, 40mmol). Heat to reflux under nitrogen protection, temperature is 180℃, time is 48h. After the reaction is completed, column chromatography with petroleum ether and ethyl acetate mixed solvent to obtain the product, finally get a yellow oil product 0.608g, yield 80%.

[0059] S3, in a two-necked flask, add the product of step S2 (0.507 g, 1 mmol), tetrakis(triphenylphosphine)palladium (50 mg), potassium carbonate (0.276 g, 2 mmol) and 20 mL of N,N-dimethylformamide (DMF), stir to clarify the solution under nitrogen protection, then add 2,2',2"-(lH-phenalene-2,5,8-triyl)tris(4,4,5,5-tetramethyl-l,3,2-dioxaborolane) (0.163 g, 0.3 mmol) at room temperature, heat to reflux for 24 h. After the reaction is completed, extract with ethyl acetate. Column chromatography using a mixture of methanol and ethyl acetate as the solvent to obtain the product, finally obtain a yellowish solid WuJ-2-POET 0.342 g, yield 79%.

[0060] S4, dissolve the product obtained in the above reaction 0.3 g in 15 mL of dichloromethane, add 2 mL of trimethylsilyl bromide dropwise under nitrogen protection, stir at room temperature for 12 h. After the reaction is completed, add 5 mL of methanol to the system to remove excess trimethylsilyl bromide, stir for 3 h. Concentrate the solution under reduced pressure, then add enough deionized water to precipitate, and the precipitated product is obtained after filtration and drying to obtain a yellowish solid WuJ-2 0.207 g, yield 78%.

[0061] The reaction equation of step S3 is as follows:

[0062]

[0063] The structural formula of the final product is as follows:

[0064]

[0065] Example 3: Synthesis of star-shaped organic compound WuJ-3

[0066] S1, in a two-necked flask, add tetrahydrofuran (THF) 20 mL. Add phase transfer catalyst benzyltriethylammonium chloride (TEBAC) (0.454 g, 2 mmol), sodium hydroxide (0.082 g, 2 mmol), 10-bromo-7(H)-benzo[c]carbazole (0.592 g, 2 mmol), palladium acetate (23 mg), tri-tert-butylphosphine (0.404 g, 2 mmol) and 1,3-dibromopropane (6 g, 30 mmol). Heat to reflux under nitrogen protection, the temperature is 80°C, the reaction time is 6 h. After the reaction is completed, extract with ethyl acetate. Column chromatography using a mixture of petroleum ether and ethyl acetate as the solvent to obtain the product, finally obtain a yellowish solid 0.756 g, yield 90%.

[0067] S2, two-mouth flask, add the product of step S1 (0.646g, 1.5mmol), palladium acetate (23mg) and triethyl phosphite (5g, 30mmol). Heat the reaction under reflux at 180°C for 24h under nitrogen protection. After the reaction, the product is obtained by column chromatography using a mixture of petroleum ether and ethyl acetate as the solvent, and finally 0.702g of yellowish oil is obtained with a yield of 99%.

[0068] S3, two-mouth flask, add the product of step S2 (0.473g, 1mmol), palladium acetate (23mg) and triethyl phosphite (5g, 30mmol). Heat the reaction under reflux at 180°C for 24h under nitrogen protection. After the reaction, the product is obtained by column chromatography using a mixture of petroleum ether and ethyl acetate as the solvent, and finally 0.702g of yellowish oil is obtained with a yield of 99%.

[0069] S4, dissolve the product obtained in the above reaction (0.3g) in 15ml of dichloromethane, and then add 2ml of trimethylsilyl bromide dropwise under nitrogen protection. Stir the mixture at room temperature for 12h. After the reaction, add 5ml of methanol to the system to remove excess trimethylsilyl bromide, and then stir the mixture for 3h. Concentrate the solution by distillation under reduced pressure, and then add enough deionized water to precipitate the product. After filtration and drying, 0.224g of yellowish solid WuJ-3 is obtained with a yield of 85%.

[0070] The reaction equation of step S3 is as follows:

[0071]

[0072] The structural formula of the final product is as follows:

[0073]

[0074] Example 4: Synthesis of star-shaped organic compound WuJ-4

[0075] S1, In a two-necked flask, THF 20 ml was added. Phase transfer catalyst benzyl triethyl ammonium chloride (TEBAC) (0.454 g, 2 mmol), sodium hydroxide (0.082 g, 2 mmol), 10-bromo-7(H)-benzo[c]carbazole (0.592 g, 2 mmol) and 4,4'-dibromo biphenyl (9 g, 30 mmol) were added. The reaction was heated under reflux at 80 °C for 12 h under nitrogen. After the reaction was completed, the product was extracted with ethyl acetate. The product was obtained by column chromatography using a mixture of petroleum ether and ethyl acetate as the solvent. Finally, 0.789 g of a yellowish solid was obtained with a yield of 75%.

[0076] S2, In a two-necked flask, the product of step S1 (0.736 g, 1.4 mmol) and triethyl phosphite (5 g, 30 mmol) were added. The reaction was heated under reflux at 200 °C for 36 h under nitrogen. After the reaction was completed, the product was obtained by column chromatography using a mixture of petroleum ether and ethyl acetate as the solvent. Finally, 0.653 g of a yellowish oil was obtained with a yield of 80%.

[0077] S3, In a two-necked flask, the product of step S2 (0.583 g, 1 mmol), tetrakis(triphenylphosphine)palladium (50 mg), potassium carbonate (0.276 g, 2 mmol) and 20 mL of toluene (Tol) were added. The solution was stirred under nitrogen until it became clear, then 2,2'-(5'-(4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl)-[1,1':3',1"-terphenyl]-4,4"-diyl)bis(4,4,5,5-tetramethyl-1,3,2-dioxaborolan) (0.205 g, 0.3 mmol) was added at room temperature, and the reaction was heated under reflux for 24 h. After the reaction was completed, the product was extracted with ethyl acetate. The product was obtained by column chromatography using a mixture of methanol and ethyl acetate as the solvent. Finally, 0.457 g of a yellowish solid, WuJ-4-POET, was obtained with a yield of 84%.

[0078] S4, The product obtained in the above reaction (0.3 g) was dissolved in 15 mL of dichloromethane, and 2 mL of trimethylsilyl bromide was added dropwise under nitrogen. The solution was stirred at room temperature for 12 h. After the reaction was completed, 5 mL of methanol was added to the system to remove excess trimethylsilyl bromide, and the solution was stirred for 3 h. The solution was concentrated under reduced pressure, then a sufficient amount of deionized water was added to precipitate the product. The precipitated product was filtered and dried to obtain a yellowish solid, WuJ-4, 0.182 g, with a yield of 67%.

[0079] The reaction equation of step S3 is as follows:

[0080]

[0081] The structural formula of the final product is as follows:

[0082]

[0083] Example 5: Synthesis of Star-shaped Organic Compound WuJ-5

[0084] S1, In a two-necked flask, THF 20 ml was added. Phase transfer catalyst tetrabutyl ammonium bromide (TBAB) (0.644 g, 2 mmol), cesium carbonate (0.65 g, 2 mmol), 10-bromo-7(H)-benzo[c]carbazole (0.592 g, 2 mmol) and 4-bromobenzyl bromide (5 g, 20 mmol) were added. The reaction was heated under reflux at 70 °C for 18 h under nitrogen protection. After the reaction was completed, extraction was performed with ethyl acetate. The product was obtained by column chromatography using a mixed solvent of petroleum ether and ethyl acetate, and finally a yellowish solid 0.862 g was obtained with a yield of 90%.

[0085] S2, In a two-necked flask, the product of step S1 (0.718 g, 1.5 mmol) and triethyl phosphite (5 g, 30 mmol) were added. The reaction was heated under reflux at 180 °C for 36 h under nitrogen protection. After the reaction was completed, the product was obtained by column chromatography using a mixed solvent of petroleum ether and ethyl acetate, and finally a yellowish oil product 0.665 g was obtained with a yield of 80%.

[0086] S3, In a two-necked flask, the product of step S2 (0.521 g, 1 mmol), tetrakis(triphenylphosphine)palladium (50 mg) and 20 ml N,N-dimethylformamide (DMF) were added. The solution was stirred under nitrogen protection until it became clear, and then 2,5,8-tris(trimethylstannyl)benzo[1,2-b:3,4-b':5,6-b"]trithiophene (0.22 g, 0.3 mmol) was added at room temperature. The reaction was heated under reflux for 24 h. After the reaction was completed, extraction was performed with ethyl acetate. The product was obtained by column chromatography using a mixed solvent of methanol and ethyl acetate, and finally a yellowish solid WuJ-5-POET 0.287 g was obtained with a yield of 61%.

[0087] S4, The product obtained in the above reaction was dissolved in 15 ml dichloromethane, and 2 ml trimethylsilyl bromide was added dropwise under nitrogen protection. The system was stirred at room temperature for 12 h. After the reaction was completed, 5 ml methanol was added to the system to remove excess trimethylsilyl bromide, and the system was stirred for 3 h. The solution was concentrated by distillation under reduced pressure, and then a sufficient amount of deionized water was added to precipitate the product. The precipitated product was filtered and dried to obtain a brown solid WuJ-5 0.134 g with a yield of 75%.

[0088] The reaction equation of step S3 is as follows:

[0089]

[0090] The structural formula of the final product is as follows:

[0091]

[0092] Example 6: Synthesis of Star-shaped Organic Compound WuJ-6

[0093] S1, In a two-necked flask, THF 20 ml was added. Phase transfer catalyst tetrabutylammonium bromide (TBAB) (0.644 g, 2 mmol), cesium carbonate (0.65 g, 2 mmol), 10-bromo-7(H)-benzo[c]carbazole (0.592 g, 2 mmol), palladium acetate (23 mg), tri-tert-butylphosphine (0.404 g, 2 mmol) and p-bromophenylethyl bromide (5.3 g, 20 mmol) were added. The reaction was heated under reflux with nitrogen protection, the reaction temperature was 70°C, and the reaction time was 18 h. After the reaction was completed, it was extracted with ethyl acetate. The product was obtained by column chromatography using a mixed solvent of petroleum ether and ethyl acetate, and finally 0.862 g of light yellow solid was obtained with a yield of 90%.

[0094] S2, In a two-necked flask, the product of step S1 (0.718 g, 1.5 mmol) and triethyl phosphite (5 g, 30 mmol) were added. The reaction was heated under reflux with nitrogen protection, the temperature was 180°C, and the time was 36 h. After the reaction was completed, the product was obtained by column chromatography using a mixed solvent of petroleum ether and ethyl acetate, and finally 0.665 g of light yellow oily product was obtained with a yield of 80%.

[0095] S3, In a two-necked flask, the product of step S2 (0.535 g, 1 mmol), tetrakis(triphenylphosphine)palladium (50 mg) and 20 ml of N,N-dimethylformamide (DMF) were added. The solution was stirred under nitrogen protection until it was clear, then 1,3,5-tris(5-(trimethylstannyl)thiophen-2-yl)benzene (0.243 g, 0.3 mmol) was added at room temperature, and the reaction was heated under reflux for 24 h. After the reaction was completed, it was extracted with ethyl acetate. The product was obtained by column chromatography using a mixed solvent of methanol and ethyl acetate, and finally 0.360 g of light yellow solid WuJ-6-POET was obtained with a yield of 71%.

[0096] S4, The product obtained in the above reaction was dissolved in 15 ml of dichloromethane, 2 ml of trimethylsilyl bromide was added dropwise under nitrogen protection, and stirred at room temperature for 12 h. After the reaction was completed, 5 ml of methanol was added to the system to remove excess trimethylsilyl bromide, and stirred for 3 h. The solution was concentrated under reduced pressure, then enough deionized water was added to precipitate, and the precipitated product was filtered and dried to obtain light yellow solid WuJ-6 0.211 g with a yield of 78%.

[0097] The reaction equation of step S3 is as follows:

[0098]

[0099] The structural formula of the final product is as follows:

[0100]

[0101] Example 7: Preparation of perovskite solar cells of star-shaped organic compounds

[0102] A perovskite solar cell device was prepared using the star-shaped organic compounds obtained in Examples 1-6 as a hole transport material, and the device structure is as shown in Figure 1 from top to bottom, including a cathode layer, a hole blocking layer, an electron transport layer, a perovskite active layer, a hole transport layer and an anode layer, and the specific preparation process is as follows:

[0103] The star-shaped organic compound was dissolved in DMF to prepare a solution with a concentration of 0.15 mg / ml. 50 microliters of the star-shaped organic compound solution was spin-coated on an FTO glass substrate (the FTO glass substrate was ultrasonically cleaned with detergent, deionized water, acetone, isopropanol for 10 min each before spin coating, and then treated with ultraviolet ozone for 30 min), and then heat annealing treatment (80°C / 10 min) was performed to form a hole transport layer. Subsequently, a perovskite active layer was prepared on the hole transport layer, and the active layer was subjected to heat annealing treatment (100°C / 30 min), followed by evaporation of 25 nm thick C 60 (structure as shown in Figure 3 ) to form an electron transport layer, and evaporation of 5 nm thick BCP (structure as shown in Figure 3 ) to form a hole blocking layer, and finally evaporation of 120 nm Ag as a top electrode to form a cathode layer.

[0104] Photovoltaic device performance: under white light 1.5G (100 mW cm -2 ), the device performance is shown in Table 1, where V oc represents open circuit voltage, J sc represents short circuit current, FF represents fill factor, and PCE represents photoelectric conversion efficiency.

[0105] Table 1: Performance statistics of perovskite solar cells

[0106] Hole transport material V oc (V) J sc (mA / cm 2 )]]> FF (%) PCE (%) Wu J-1 1.14 25.21 83.2 23.92 Wu J-2 1.15 25.52 84.1 24.68 Wu J-3 1.19 25.65 86.6 26.43 Wu J-4 1.16 24.68 82.3 23.56 Wu J-5 1.17 24.87 84.5 24.59 Wu J-6 1.19 25.58 85.5 26.02

[0107] Example 8: Preparation of organic solar cells of star-shaped organic compounds

[0108] An organic solar cell device was prepared using the star-shaped organic compounds obtained in Examples 1-6 as a hole transport material, and the device structure is as shown in Figure 2As shown, from top to bottom, the device includes a cathode layer, an electron transport layer, a photoactive layer, a hole transport layer and an anode layer, and the specific preparation process is as follows:

[0109] The star-shaped organic compound is dissolved in DMF to prepare a solution with a concentration of 0.15 mg / ml, 50 microliters of the star-shaped organic compound solution is spin-coated on an ITO glass substrate (the ITO glass substrate is ultrasonically cleaned with detergent, deionized water, acetone, isopropanol for 10 min each before spin coating, and is subjected to ultraviolet ozone treatment for 30 min), to form a hole transport layer, 8 mg of PM6 is mixed with 9.6 mg of BTP-eC9, 1 mL of chloroform is added for dissolution, and a photoactive layer is prepared on the modified ITO glass substrate by spin coating, the photoactive layer is subjected to heat annealing treatment (100℃ / 10min), and then PDINN (concentration: 1.5mg mL -1 of methanol solution) is spin-coated to form an electron transport layer, and finally, 120 nm of Ag is evaporated as a top electrode.

[0110] Photovoltaic device performance: under white light 1.5G (100mW cm -2 ), the device performance is shown in Table 2, wherein V oc represents open circuit voltage, J sc represents short circuit current, FF represents fill factor, and PCE represents photoelectric conversion efficiency.

[0111] Table 2: Performance statistics of organic solar cells

[0112] Hole transport material V oc (V) J sc (mA / cm 2 )]]> FF (%) PCE (%) Wu J-1 0.83 28.21 77.2 18.01 Wu J-2 0.85 28.52 78.1 18.93 Wu J-3 0.87 29.11 79.0 20.01 Wu J-4 0.83 28.68 78.1 18.57 Wu J-5 0.85 28.87 77.1 18.90 Wu J-6 0.86 29.01 79.3 19.78

[0113] As can be seen from Table 1 and Table 2, the star-shaped organic compound prepared by the method of the present application is used as a hole transport layer material of an organic solar cell or a perovskite solar cell, the V oc , J sc , FF values of the prepared photoelectric functional device are high, and the PCE performance is significantly improved.

[0114] Aspects, embodiments, features of the present application should be considered illustrative in all aspects and do not limit the present application, and the scope of the present application is only defined by the claims. Other embodiments, modifications and uses will be apparent to those skilled in the art without departing from the spirit and scope of the claimed application.

[0115] In the preparation method of the present application, the order of each step is not limited to the order listed, and for those skilled in the art, the order of each step can be changed without creative labor, which is within the protection scope of the present application. In addition, two or more steps or actions can be performed simultaneously.

[0116] It should be noted that the embodiments described herein are merely illustrative of the present application and should not be construed as limiting the scope of the present application. Those skilled in the art can make various modifications or additions to the embodiments described herein or adopt similar ways to replace them without departing from the spirit of the present application. It is not necessary or possible to describe all the embodiments herein. Any obvious changes or variations derived from the spirit of the present application are still within the scope of the present application, and any additional limitations are contrary to the spirit of the present application.

Claims

1. A star-shaped self-assembled hole transport layer material, characterized in that, The star-shaped organic compound comprises a structure shown in general formula (1): Formula (1), In formula (1), Ar is one of structures shown in general formula (2): Equation (2), The linker is one of structures shown in general formula (3): Formula (3); Wherein, n, a, b, x, y are independently natural numbers from 0 to 9.

2. The method for preparing a star-shaped self-assembled hole transport layer material as described in claim 1, characterized in that, The method comprises the following steps: S1, under the protection of inert gas, 10-halogen-7(H)-benzo[c]carbazole is dissolved in an organic solvent, then a linker with a halogen end group is added, and the mixture is heated to reflux under the catalysis of a catalyst and in an alkaline environment, and then extracted and column chromatographed to obtain a solid product; S2, the product of step S1 is mixed with triethyl phosphite, heated to reflux under the protection of inert gas to perform an Arbuzal reaction, and then column chromatographed to obtain a benzo carbazole derivative with a phosphate group; S3, under the protection of inert gas, the benzo carbazole derivative with a phosphate group is dissolved in an organic solvent, then a 3-trimethyl tin substituted Ar monomer or a 3-boronate substituted Ar monomer is added, and the mixture is subjected to a coupling reaction under the action of a metal catalyst, and then extracted and column chromatographed to obtain a product; S4, under the protection of inert gas, the product of step S3 is dissolved in a solvent, then trimethylsilyl bromide is added, and then quenched with an alcohol, and then precipitated with a poor solvent, and then the precipitated product is extracted and dried to obtain a star-shaped self-assembled hole transport layer material.

3. The preparation method according to claim 2, characterized in that, In step S1, The molar ratio of 10-halogen-7(H)-benzo[c]carbazole to the linker with a halogen end group is 1:5-30; And / or, the molar ratio of the catalyst to 10-halogen-7(H)-benzo[c]carbazole is 1-3:1; And / or, the heating reflux reaction temperature is 60-100 ℃, and the reaction time is 3-12 h.

4. The preparation method according to claim 2, characterized in that, In step S2, The molar ratio of the product of step S1 to triethyl phosphite is 1:5-25; And / or, the heating reflux temperature is 140-180 ℃, and the time is 5-48 h.

5. The preparation method according to claim 2, characterized in that, In step S3, the molar ratio of the 3-trimethyl tin substituted Ar monomer or the 3-boronate substituted Ar monomer to the benzo carbazole derivative with a phosphate group is 1:3-4; And / or, the coupling reaction of step S3 is carried out under heating reflux, the heating temperature is 80-130 ℃, and the reaction time is 2-40 h; And / or, in step S4, the molar ratio of the product of step S3 to trimethylsilyl bromide is 1:5-30; And / or, the reaction of step S4 is carried out at 10-40 ℃ for 5-40 h.

6. Use of a star-shaped self-assembled hole transport layer material according to claim 1 for the preparation of an optoelectronic functional device, characterized in that, The photoelectric functional device is an organic solar cell or a perovskite solar cell.

7. Use according to claim 6, characterized in that, The photoelectric functional device is an organic solar cell, and the device structure comprises a cathode layer, an electron transport layer, a photoactive layer, a hole transport layer and an anode layer, and the hole transport layer comprises the star-shaped self-assembled hole transport layer material.

8. Use according to claim 6, characterized in that, The photoelectric functional device is a perovskite solar cell, and the device structure comprises a cathode layer, a hole blocking layer, an electron transport layer, a perovskite active layer, a hole transport layer and an anode layer, and the hole transport layer comprises the star-shaped self-assembled hole transport layer material.

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