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

Abstract

The invention belongs to the technical field of photoelectric materials, and relates to a star-shaped self-assembly hole transport layer material, a preparation method and application thereof. The star-shaped self-assembly hole transport layer material comprises a star-shaped organic compound with a structure as shown in a general formula (1), and # imgabs0 # star-shaped organic compound takes an aromatic three-site group as a core, and adopts a star-shaped bridging unit to connect three phosphoric acid benzocarbazole units. As a hole transport layer material of a photoelectric functional device, the star-shaped organic compound is beneficial to improvement of device efficiency and stability, and a reliable basis is provided for industrial development of perovskite solar cells and organic solar cells.

Description

Technical Field

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

[0002] The country has successively introduced relevant policies, the implementation of which will effectively promote the development of global clean energy and provide experience for countries to achieve carbon neutrality goals. Through multilateral cooperation and technological innovation, China actively promotes global sustainable development, which is not only in line with national interests, but also will have a far-reaching impact on global climate governance.

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

[0004] In the field of solar cells, the research and application of perovskite solar cells are of great strategic significance in achieving the global carbon peak and carbon neutrality goals. Compared with traditional silicon-based solar cells, perovskite solar cells have demonstrated 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 economy of solar power generation, but also provide feasibility for its large-scale promotion. In particular, perovskite solar cells with an inverted structure are considered to be one of the mainstream commercialization routes of this emerging photovoltaic technology due to their competitive photoelectric conversion efficiency, good stability and compatibility with tandem solar cells. At present, 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 are widely used because of their suitable energy level matching and low non-radiative recombination losses.

[0005] However, the uneven distribution of commonly used self-assembled films on the substrate and the poor surface wettability of perovskite precursors make it challenging to directly deposit high-quality perovskite films on self-assembled hole transport layer materials. These problems not only reduce manufacturing yields, but may also cause undesirable interface losses at the interface between the perovskite layer and the hole transport layer, especially when manufacturing large-area devices. In order to promote the further development of organic solar cells and perovskite solar cell technology and improve the efficiency and stability of devices, it is particularly important to develop new and efficient hole transport materials. Improvements in these materials will help overcome the defects in existing technologies, improve the overall performance of perovskite solar cells, and promote their widespread application around the world. Summary of the invention

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

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

[0008] A star-shaped self-assembled hole transport layer material comprises a star-shaped organic compound having a structure shown in general formula (1):

[0009]

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

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

[0012]

[0013] Appearing in the text Represents the connection end.

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

[0015]

[0016] Here, n, a, b, x, and y are all natural numbers between 0 and 9.

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

[0018] A method for preparing a star-shaped self-assembled hole transport layer material comprises the following steps:

[0019] S1. Under the protection of inert gas, 10-halogen-7(H)-benzo[c]carbazole is dissolved in an organic solvent, and a linker (X-linker-X) with a halogen terminal group is added, and the mixture is heated under reflux in the presence of a catalyst and an alkaline environment to obtain a solid product after extraction and column chromatography;

[0020] S2, mixing the product of step S1 with triethyl phosphite, heating under reflux under inert gas protection to perform Arbuzal reaction, and obtaining a benzocarbazole derivative with a phosphate group after column chromatography;

[0021] S3, under the protection of an inert gas, dissolving a benzocarbazole derivative with a phosphate group in an organic solvent, then adding an Ar monomer substituted with three trimethyltin groups or an Ar monomer substituted with three borate groups, carrying out a coupling reaction under the action of a metal catalyst, and obtaining a product after extraction and column chromatography;

[0022] S4. Under the protection of an inert gas, the product of step S3 is dissolved in a solvent, trimethylsilyl bromide is added for reaction, then quenched with an alcohol, and precipitated with a poor solvent. The precipitated product is filtered and dried to obtain a star-shaped self-assembled hole transport layer material.

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

[0024]

[0025] X is a halogen element, 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), etc. 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), etc.; the metal catalyst is preferably palladium acetate, tetrakistriphenylphosphine palladium, di(tri-tert-butylphosphine) palladium, tri(dibenzylideneacetone) dipalladium, methanesulfonic acid (2-dicyclohexylphosphine-2', 4', 6'-triisopropyl-1,1'-biphenyl) (2'-amino-1,1'-biphenyl-2-yl) palladium (XPhos-Pd-G3), etc. The alkaline environment is preferably achieved by adding one or more of potassium carbonate, sodium hydroxide, potassium hydroxide, cesium carbonate, triethylamine, etc. The molar ratio of 10-halogen-7(H)-benzo[c]carbazole to the linker with a halogen element terminal group 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 hours.

[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 reflux temperature is preferably 140 to 200° C., and the time is preferably 5 to 48 hours. Further preferably, step S2 is performed under a metal catalyst to perform an Arbuzal reaction.

[0030] In step S3 of the preparation method, the molar ratio of the Ar monomer substituted by three trimethyltin groups or the Ar monomer substituted by three borate groups to the benzocarbazole derivative with a phosphate group is preferably 1:3 to 4. The coupling reaction is carried out under heating reflux, the heating temperature is preferably 80 to 130° C., and the reaction time is preferably 2 to 40 hours.

[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), etc. The reaction is preferably carried out at 10 to 40° C., and the reaction time is preferably 5 to 40 hours.

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

[0033] The third object of the present invention is achieved by the following technical solutions:

[0034] A use of a star-shaped self-assembled hole transport layer material in the preparation of a photoelectric functional device, wherein the photoelectric functional device is an organic solar cell or a perovskite solar cell.

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

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

[0037] Preferably, when the optoelectronic functional device is a perovskite solar cell, the device structure includes 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 includes the star-shaped self-assembled hole transport layer material.

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

[0039] 1. The present invention provides a novel star-shaped self-loaded hole transport layer material, which has a unique structure, with an aromatic three-point group as the core, and a star-shaped bridging unit to connect three benzocarbazole phosphate units.

[0040] 2. The present invention also provides a method for preparing the novel star-shaped self-assembled hole transport layer material. The entire preparation method is relatively simple, the synthesis process cost is low, and it is conducive to large-scale production and application.

[0041] 3. The star-shaped self-assembled hole transport layer material provided by the present invention has excellent hole transport performance due to its special structural design. Compared with the small molecule benzocarbazole phosphate SAM, the star-shaped organic compound has a larger π conjugated structure, and the larger conjugated system is also more conducive to the transmission of holes between molecules and blocks electrons. Compared with ordinary monolayer materials, the tripod star-shaped molecules have a tendency to accumulate face to face, thereby enhancing hole collection and reducing interfacial charge recombination. In addition, thanks to the presence of multiple phosphate anchoring groups, the material can form a complete coverage on the substrate surface and stably self-assemble, thereby improving the wettability of the material on the substrate. This material exhibits excellent properties in terms of conductivity and wettability on conductive substrates. And the interaction between the star-shaped molecules and the transparent conductive substrate is stronger and not easy to migrate molecules, which ultimately achieves the improvement of battery device efficiency and stability, and provides a reliable foundation for the industrial development of perovskite solar cells and organic solar cells. BRIEF DESCRIPTION OF THE DRAWINGS

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

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

[0044] Figure 3 This is a schematic diagram of the molecular structure of C60, BCP, and PDINN. DETAILED DESCRIPTION

[0045] The technical scheme of the present invention is further described below by specific examples and accompanying drawings. It should be understood that the specific examples described herein are only used to help understand the present invention and are not intended for specific limitations of the present invention. The accompanying drawings used herein are only for better illustrating the disclosure of the present invention and do not have a limiting effect on the scope of protection. If not otherwise specified, the raw materials used in the embodiments of the present invention are all commonly used raw materials in the art, and the methods used in the embodiments 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. Add 20 ml of tetrahydrofuran (THF) to a two-necked flask. Add phase transfer catalyst tetrabutylammonium bromide (TBAB) (0.644 g, 2 mmol), cesium carbonate (0.65 g, 2 mmol), 10-bromo-7 (H) -benzo [c] and carbazole (0.592 g, 2 mmol) and 1,4-dibromobutane (4.32 g, 20 mmol). Heat to reflux under nitrogen protection at 80 ° C for 6 h. After the reaction is completed, extract with ethyl acetate. The product is obtained by column chromatography using a mixed solvent of petroleum ether and ethyl acetate, and finally 0.767 g of a light yellow solid is obtained with a yield of 89%.

[0049] S2, the product of step S1 (0.646, 1.5mmol) and triethyl phosphite (5g, 30mmol) were added to a two-necked flask. The mixture was heated to reflux under nitrogen protection at a temperature of 180°C for 24h. After the reaction, the product was obtained by column chromatography using a mixed solvent of petroleum ether and ethyl acetate, and finally 0.715g of a light yellow oily product was obtained with a yield of 98%.

[0050] S3, two-necked flask, add the product of S2 (0.487g, 1mmol), tetrakistriphenylphosphine palladium (50mg), potassium carbonate (0.276g, 2mmol) and 20mL N, N-dimethylformamide (DMF), stir under nitrogen protection until the solution is clear, then add 1,3,5-benzenetriboric acid tripinacol ester (0.137g, 0.3mmol) at room temperature, heat reflux reaction for 24h. After the reaction is completed, extract with ethyl acetate. The product is obtained after column chromatography using a mixed solvent of methanol and ethyl acetate, and finally obtains light yellow solid WuJ-1-POET 0.32g, with a yield of 82%.

[0051] S4. Take 0.3 g of the product obtained by the above reaction and dissolve it in 15 ml of dichloromethane. Add 2 ml of trimethylsilyl bromide dropwise under nitrogen protection and 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 and stir for 3 h. Concentrate the solution by vacuum distillation, then add sufficient deionized water for precipitation, and filter and dry the precipitated product to obtain 0.182 g of light yellow solid WuJ-1 with a yield of 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. Add 20 ml of N, N-dimethylformamide (DMF) to a two-necked bottle. Add phase transfer catalyst tetrabutylammonium bromide (TBAB) (0.644 g, 2 mmol), cesium carbonate (0.65 g, 2 mmol), 10-bromo-7 (H) -benzo [c] and carbazole (0.592 g, 2 mmol) and 1, 4-dibromobenzene (7 g, 30 mmol). Heat to reflux under nitrogen protection at 80 ° C for 6 h. After the reaction is completed, extract with ethyl acetate. The product is obtained by column chromatography using a mixed solvent of petroleum ether and ethyl acetate, and finally 0.695 g of a light yellow solid is obtained with a yield of 77%.

[0058] S2, the product of step S1 (0.676g, 1.5mmol) and triethyl phosphite (6.7g, 40mmol) were added to a two-necked flask. The mixture was heated to reflux under nitrogen protection at a temperature of 180°C for 48h. After the reaction was completed, the product was obtained by column chromatography using a mixed solvent of petroleum ether and ethyl acetate, and finally 0.608g of a light yellow oily product was obtained with a yield of 80%.

[0059] S3, in a two-necked flask, add the product of step S2 (0.507 g, 1 mmol), tetrakistriphenylphosphine palladium (50 mg), potassium carbonate (0.276 g, 2 mmol) and 20 mL N, N-dimethylformamide (DMF), stir under nitrogen protection until the solution is clear, then add 2,2',2"-(1H-phenaene-2,5,8-triyl)tris(4,4,5,5-tetramethyl-1,3,2-dioxaborane) (0.163 g, 0.3 mmol) at room temperature, and heat to reflux for 24 h. After the reaction is completed, extract with ethyl acetate. The product is obtained by column chromatography using a mixed solvent of methanol and ethyl acetate, and finally 0.342 g of light yellow solid WuJ-2-POET is obtained with a yield of 79%.

[0060] S4. Take 0.3g of the product obtained by the above reaction and dissolve it in 15ml of dichloromethane. Add 2ml of trimethylsilyl bromide dropwise under nitrogen protection and stir at room temperature for 12h. After the reaction is completed, add 5ml of methanol to the system to remove excess trimethylsilyl bromide and stir for 3h. Concentrate the solution by vacuum distillation, then add enough deionized water for precipitation, and filter and dry the precipitated product to obtain 0.207g of light yellow solid WuJ-2 with a yield of 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. Add 20 ml of tetrahydrofuran (THF) to a two-necked flask. 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] and 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 at 80 ° C for 6 h. After the reaction is completed, extract with ethyl acetate. The product is obtained by column chromatography using a mixed solvent of petroleum ether and ethyl acetate, and finally 0.756 g of a light yellow solid is obtained with a yield of 90%.

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

[0068] S3, in a two-necked flask, add the product of step S2 (0.473g, 1mmol), tetrakistriphenylphosphine palladium (50mg), potassium carbonate (0.276g, 2mmol) and 20mL N, N-dimethylformamide (DMF), stir under nitrogen protection until the solution is clear, then add tris (4- (4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl) phenyl) amine (0.187g, 0.3mmol) at room temperature, and heat to reflux for 24h. After the reaction is completed, extract with ethyl acetate. The product is obtained after column chromatography using a mixed solvent of methanol and ethyl acetate, and finally obtains 0.389g of light yellow solid WuJ-3-POET with a yield of 91%.

[0069] S4. Take 0.3g of the product obtained by the above reaction and dissolve it in 15ml of dichloromethane. Add 2ml of trimethylsilyl bromide dropwise under nitrogen protection and stir at room temperature for 12h. After the reaction is completed, add 5ml of methanol to the system to remove excess trimethylsilyl bromide and stir for 3h. Concentrate the solution by vacuum distillation, then add enough deionized water for precipitation, and filter and dry the precipitated product to obtain 0.224g of light yellow solid WuJ-3 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. Add 20 ml of tetrahydrofuran (THF) to a two-necked flask. 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) and 4,4'-dibromobiphenyl (9 g, 30 mmol). Heat to reflux under nitrogen protection at 80 ° C for 12 h. After the reaction, extract with ethyl acetate. The product is obtained by column chromatography using a mixed solvent of petroleum ether and ethyl acetate, and finally 0.789 g of a light yellow solid is obtained with a yield of 75%.

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

[0077] S3, in a two-necked flask, the product of step S2 (0.583g, 1mmol), tetrakistriphenylphosphine palladium (50mg), potassium carbonate (0.276g, 2mmol) and 20mL toluene (Tol) were added, stirred under nitrogen protection until the solution was clear, and 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) (0.205g, 0.3mmol) was added at room temperature, and the reaction was heated to reflux for 24h. 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 0.457g of light yellow solid WuJ-4-POET was obtained with a yield of 84%.

[0078] S4. Take 0.3g of the product obtained by the above reaction and dissolve it in 15ml of dichloromethane. Add 2ml of trimethylsilyl bromide dropwise under nitrogen protection and stir at room temperature for 12h. After the reaction is completed, add 5ml of methanol to the system to remove excess trimethylsilyl bromide and stir for 3h. Concentrate the solution by vacuum distillation, then add enough deionized water for precipitation, and filter and dry the precipitated product to obtain 0.182g of light yellow solid WuJ-4 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. Add 20 ml of tetrahydrofuran (THF) to a two-necked flask. Add 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 4-bromobenzyl bromide (5 g, 20 mmol). Heat to reflux under nitrogen protection at 70 ° C for 18 h. After the reaction is completed, extract with ethyl acetate. The product is obtained by column chromatography using a mixed solvent of petroleum ether and ethyl acetate, and finally 0.862 g of a light yellow solid is obtained with a yield of 90%.

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

[0086] S3, add the product of step S2 (0.521g, 1mmol), tetrakistriphenylphosphine palladium (50mg) and 20mLN,N-dimethylformamide (DMF) into a two-necked flask, stir under nitrogen protection until the solution is clear, then add 2,5,8-tris(trimethyltinyl)benzo[1,2-b:3,4-b':5,6-b"]terthiophene (0.22g, 0.3mmol) at room temperature, and heat to reflux for 24h. After the reaction is completed, extract with ethyl acetate. The product is obtained by column chromatography using a mixed solvent of methanol and ethyl acetate, and finally 0.287g of light yellow solid WuJ-5-POET is obtained with a yield of 61%.

[0087] S4. Take 0.2g of the product obtained by the above reaction and dissolve it in 15ml of dichloromethane. Add 2ml of trimethylsilyl bromide dropwise under nitrogen protection and stir at room temperature for 12h. After the reaction is completed, add 5ml of methanol to the system to remove excess trimethylsilyl bromide and stir for 3h. Concentrate the solution by vacuum distillation, then add enough deionized water for precipitation. After the precipitated product is filtered and dried, a brown solid WuJ-50.134g is obtained 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. Add 20 ml of tetrahydrofuran (THF) to a two-necked flask. Add phase transfer catalyst tetrabutylammonium bromide (TBAB) (0.644 g, 2 mmol), cesium carbonate (0.65 g, 2 mmol), 10-bromo-7 (H) -benzo [c] and 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). Heat to reflux under nitrogen protection, the reaction temperature is 70 ° C, and the reaction time is 18 h. After the reaction is completed, extract with ethyl acetate. The product is obtained by column chromatography using a mixed solvent of petroleum ether and ethyl acetate, and finally 0.862 g of a light yellow solid is obtained with a yield of 90%.

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

[0095] S3, in a two-necked flask, add the product of step S2 (0.535g, 1mmol), tetrakistriphenylphosphine palladium (50mg) and 20mLN, N-dimethylformamide (DMF), stir under nitrogen protection until the solution is clear, then add 1,3,5-tris(5-(trimethyltinyl)thiophene-2-yl)benzene (0.243g, 0.3mmol) at room temperature, and heat to reflux for 24h. After the reaction is completed, extract with ethyl acetate. The product is obtained after column chromatography using a mixed solvent of methanol and ethyl acetate, and finally 0.360g of light yellow solid WuJ-6-POET is obtained, with a yield of 71%.

[0096] S4. Take 0.3g of the product obtained by the above reaction and dissolve it in 15ml of dichloromethane. Add 2ml of trimethylsilyl bromide dropwise under nitrogen protection and stir at room temperature for 12h. After the reaction is completed, add 5ml of methanol to the system to remove excess trimethylsilyl bromide and stir for 3h. Concentrate the solution by vacuum distillation, then add enough deionized water for precipitation, and filter and dry the precipitated product to obtain 0.211g of light yellow solid WuJ-6 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] The star-shaped organic compounds obtained in Examples 1 to 6 are used as hole transport materials to prepare a perovskite solar cell device. The device structure is as follows: Figure 1 As shown, from top to bottom, it includes a cathode layer, a hole blocking layer, an electron transport layer, a perovskite active layer, a hole transport layer and an anode layer. 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 the FTO glass substrate (the FTO glass substrate was ultrasonically cleaned with detergent, deionized water, acetone, and isopropanol for 10 minutes each before spin coating, and treated with ultraviolet ozone for 30 minutes), and then thermally annealed (80°C / 10 minutes) to form a hole transport layer. Subsequently, a perovskite active layer was prepared on the hole transport layer. The active layer was thermally annealed (100°C / 30 minutes), and then a 25 nm thick C 60 (Structural formula such as Figure 3 As shown) to form an electron transport layer, and evaporate 5nm thick BCP (structural formula as shown) Figure 3 As shown in the figure, a hole blocking layer is formed, and finally 120nm Ag is evaporated as the top electrode to form a cathode layer.

[0104] Photovoltaic device performance: in white light 1.5G (100mW cm -2 ) irradiation, the device performance is shown in Table 1 below, where V oc represents the 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 materials <![CDATA[V oc (V)]]> <![CDATA[J sc (mA / cm 2 )]]> FF(%) PCE(%) WuJ-1 1.14 25.21 83.2 23.92 WuJ-2 1.15 25.52 84.1 24.68 WuJ-3 1.19 25.65 86.6 26.43 WuJ-4 1.16 24.68 82.3 23.56 WuJ-5 1.17 24.87 84.5 24.59 WuJ-6 1.19 25.58 85.5 26.02

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

[0108] The star-shaped organic compounds obtained in Examples 1 to 6 are used as hole transport materials to prepare organic solar cell devices. The device structure is as follows: Figure 2As shown, from top to bottom, it includes a cathode layer, an electron transport layer, a photoactive layer, a hole transport layer and an anode layer. The specific preparation process is as follows:

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

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

[0111] Table 2 Statistics of organic solar cell performance

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

[0113] It can be seen from Table 1 and Table 2 that the V of the photoelectric functional device prepared by using the star-shaped organic compound prepared by the present invention as the hole transport layer material of the organic solar cell or the perovskite solar cell is oc , J sc , FF value is high, and PCE performance is significantly improved.

[0114] The various aspects, embodiments, and features of the present invention should be considered to be illustrative in all aspects and not limiting of the present invention, the scope of which is defined solely 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 invention.

[0115] In the preparation method of the present invention, the order of each step is not limited to the order listed. For those skilled in the art, without creative work, the order of each step is also within the protection scope of the present invention. In addition, two or more steps or actions can be performed simultaneously.

[0116] Finally, it should be noted that the specific embodiments described herein are merely examples of the present invention, and are not intended to limit the implementation methods of the present invention. A person skilled in the art of the present invention may make various modifications or supplements to the specific embodiments described, or replace them in a similar manner. It is not necessary and impossible to provide all examples of all implementation methods here. However, these obvious changes or modifications derived from the essential spirit of the present invention still fall within the scope of protection of the present invention, and interpreting them as any additional limitation is contrary to the spirit of the present invention.

Claims

1. A star-shaped self-assembled hole transport layer material, characterized in that: It includes a star-shaped organic compound having a structure shown in the general formula (1): In formula (1), Ar is a structure including an aromatic group; linker is a structure including one or more of a C1-C10 straight-chain alkyl group, a phenyl group, and a biphenyl group.

2. The star-shaped self-assembled hole transport layer material according to claim 1, characterized in that: The Ar is one of the structures shown in general formula (2):

3. The star-shaped self-assembled hole transport layer material according to claim 1, characterized in that: The linker is one of the structures shown in general formula (3): Here, n, a, b, x, and y are all natural numbers between 0 and 9.

4. The method for preparing a star-shaped self-assembled hole transport layer material according to claim 1, characterized in that: The following steps are involved: S1. Under the protection of inert gas, 10-halogen-7(H)-benzo[c]carbazole is dissolved in an organic solvent, and a linker with a halogen terminal group is added, and the mixture is heated under reflux in the presence of a catalyst and an alkaline environment to obtain a solid product after extraction and column chromatography; S2, mixing the product of step S1 with triethyl phosphite, heating under reflux under inert gas protection to perform Arbuzal reaction, and obtaining a benzocarbazole derivative with a phosphate group after column chromatography; S3, under the protection of an inert gas, dissolving a benzocarbazole derivative with a phosphate group in an organic solvent, then adding an Ar monomer substituted with three trimethyltin groups or an Ar monomer substituted with three borate groups, carrying out a coupling reaction under the action of a metal catalyst, and obtaining a product after extraction and column chromatography; S4. Under the protection of an inert gas, the product of step S3 is dissolved in a solvent, trimethylsilyl bromide is added for reaction, then quenched with an alcohol, and precipitated with a poor solvent. The precipitated product is filtered and dried to obtain a star-shaped self-assembled hole transport layer material.

5. The preparation method according to claim 4, characterized in that: In step S1, The molar ratio of 10-halogen-7(H)-benzo[c]carbazole to the linker with a halogen element terminal group is 1:5-30; and / or, the molar ratio of the catalyst to 10-halogen-7(H)-benzo[c]carbazole is 1 to 3:1; And / or, the heating reflux reaction temperature is 60-100° C. and the reaction time is 3-12 h.

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

7. The preparation method according to claim 4, characterized in that: In step S3, the molar ratio of the Ar monomer substituted by three trimethyltin groups or the Ar monomer substituted by three borate groups to the benzocarbazole derivative having a phosphate group is 1:3-4; And / or, the coupling reaction in step S3 is carried out under heating reflux, the heating temperature is 80 to 130° C., and the reaction time is 2 to 40 hours; and / or, in step S4, the molar ratio of the product of step S3 to trimethylsilyl bromide is 1:5 to 30; And / or, the reaction in step S4 is carried out at 10-40° C. for 5-40 hours.

8. Use of a star-shaped self-assembled hole transport layer material according to claim 1 in preparing optoelectronic functional devices, characterized in that: The optoelectronic functional device is an organic solar cell or a perovskite solar cell.

9. The use according to claim 8, characterized in that: The optoelectronic 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, wherein the hole transport layer comprises the star-shaped self-assembled hole transport layer material.

10. The use according to claim 8, characterized in that: The optoelectronic functional device is a perovskite solar cell, and the device structure includes a cathode layer, a hole blocking layer, an electron transport layer, a perovskite active layer, a hole transport layer and an anode layer, wherein the hole transport layer includes the star-shaped self-assembled hole transport layer material.

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