Conjugated polymer based on monocyclic benzene, preparation method of conjugated polymer and perovskite photoelectric application of conjugated polymer

Abstract

The invention provides a conjugated polymer based on monocyclic benzene, a preparation method of the conjugated polymer and perovskite photoelectric application of the conjugated polymer. The preparation method comprises the following steps: mixing a substituent-containing benzene ring monomer and a conjugated unit Ar-containing monomer, carrying out polymerization reaction under the catalysis of a catalyst, and purifying to obtain the conjugated polymer based on monocyclobenzene. The absorption interval of the polymer provided by the invention is 300-600 nm. The material not only has higher hole mobility and good solubility, is suitable for a solution processing technology, but also shows excellent film-forming property and stability. When the compound is applied to photoelectric devices such as perovskite solar cells, extraction and transmission of holes can be effectively promoted, charge recombination is inhibited, and the photoelectric conversion efficiency of the devices is remarkably improved. Meanwhile, the polymer material is stable in structure, can effectively prevent water and oxygen from corroding a perovskite layer, greatly improves the working stability of the solar cell, prolongs the service life of the solar cell, and provides feasible conditions for developing the perovskite solar cell with high performance and high stability.

Description

Technical Field

[0001] This invention belongs to the field of organic optoelectronic materials technology, specifically relating to a class of conjugated polymers based on monocyclic benzene, their preparation methods, and perovskite optoelectronic applications. Background Technology

[0002] As society enters the information age, various electronic and optoelectronic devices face higher demands in terms of efficiency, integration, and multifunctionality. Among them, optoelectronic devices, as core functional units, have wide applications in energy, detection, sensing, and display, and have become one of the key areas of current scientific research and industrial application. In recent years, perovskite optoelectronic devices have emerged as a research hotspot, attracting widespread attention from academia and industry due to their advantages such as wide availability of materials, large-area fabrication at low temperatures, and tunable spectral response range. These devices mainly include perovskite solar cells and perovskite photodetectors, demonstrating enormous application potential in renewable energy, industrial automation, aerospace, disaster early warning, remote sensing and control, and optical communication.

[0003] In perovskite optoelectronic devices, the hole transport layer plays a crucial role, effectively blocking electrons and promoting the extraction and transport of holes, thereby significantly improving the overall device performance. Currently, the most commonly used hole transport layer materials include Spiro-OMeTAD (Electrochemistry 2017, 85, 231; Appl. Phys. Lett. 2017, 110, 123904; ACSAppl. Mater. Interfaces 2019, 11, 45796) and PTAA (Adv. Energy Mater. 2018, 8, 1801668; Org. Electron. 2019, 71, 106). Based on these hole transport layers, the efficiency of perovskite solar cells has increased from 12% in 2013 to 26% in 2025. However, these hole transport layer materials generally suffer from low carrier mobility, poor chemical stability, and complex synthesis, which severely restricts further improvement in the performance of perovskite optoelectronic devices. Therefore, developing novel hole transport layer materials that combine high hole mobility, good solution processability, and high stability will help promote further development in this field. Summary of the Invention

[0004] The primary objective of this invention is to provide a class of conjugated polymers based on monocyclic benzene and their preparation methods. These materials possess advantages such as simple synthesis, high mobility, and an absorption range in the near-ultraviolet region of 300-600 nm. These materials not only exhibit high hole mobility and good solubility, making them suitable for solution processing, but also demonstrate excellent film-forming properties and stability. When applied to optoelectronic devices such as perovskite solar cells, they can effectively promote hole extraction and transport, suppress charge recombination, and thus significantly improve the photoelectric conversion efficiency of the devices. Simultaneously, these polymer materials have a stable structure and can effectively block the erosion of the perovskite layer by water and oxygen, greatly improving the operational stability and lifespan of solar cells. This provides a feasible material basis and technical path for the development of high-performance, high-stability perovskite solar cells.

[0005] Another object of the present invention is to provide a class of perovskite optoelectronic devices based on monocyclic benzene conjugated polymers and a method for fabricating the same.

[0006] The objective of this invention can be achieved through the following technical solutions: This invention provides a class of conjugated polymers based on monocyclic benzene, as shown in Formula I:

[0007] Formula I R1 and R2 are independently selected from any one of straight-chain or branched alkyl groups having 1-30 carbon atoms, alkoxy groups, ester groups, acyloxy groups, aryl groups, aralkyl groups, haloalkyl groups, heteroalkyl groups, or combinations thereof that are substituted with substituents. X is selected from any one of fluorine, chlorine, bromine, and iodine; Ar is selected from any of the following groups: a) substituted or unsubstituted benzene, substituted or unsubstituted thiophene, substituted or unsubstituted furan, or substituted or unsubstituted selenophene; b) An aromatic fused ring formed by any two identical or different groups in a) connected by a fused ring or bridging atoms; c) A conjugated system formed by direct covalent bonding of the groups described in a) and / or b); Wherein, the substituents in the substituted benzene, substituted thiophene, substituted furan and substituted selenophene are independently hydrogen atoms, fluorine atoms, alkyl, alkoxy, alkylthio, aralkyl, heterocyclic aralkyl, acyl, acyloxy, acylthio, ester, amino, amide, alkenyl, alkynyl, carboxyl or cyano, wherein the alkyl contained in the alkyl, alkoxy, alkylthio, aralkyl and heterocyclic aralkyl are straight-chain or branched alkyl with 1-25 carbon atoms; n represents the number of repeating units in the conjugated polymer, and n is selected from a natural number between 5 and 1000.

[0008] Preferably, Ar is one of thiophene, furan, selenophene, benzene, fluorene, carbazole, silylfluorene, benzodithiophene, benzodiselenophene, benzodifuran, benzothiadiazole, phenothiazine, phenothiazine, bithiophene, thiophene, thiophene-cyclopentadiene, thiophene-pyrrole, thiophene-thiorrole, indolefluorene, indolecarbazole, pyrrole, pyrrolopyrroledione, naphthimide, peryleneimide, and derivatives of the structures described above.

[0009] More preferably, Ar is one or more coupling structures with the following structures:

[0010] Where Y is selected from any one of oxygen, sulfur, and selenium; The R3-R6 groups are independently selected from any one of hydrogen, fluorine atom, chlorine atom, substituted or unsubstituted C1-C30 alkyl, substituted or unsubstituted C1-C30 alkoxy, substituted or unsubstituted C1-C30 alkyl, substituted or unsubstituted C1-C30 ester, substituted or unsubstituted C6-C30 aryl or substituted or unsubstituted C4-C30 heteroaryl; This invention provides a method for preparing a type of conjugated polymer based on monocyclic benzene as described above, comprising the following steps: A dibromo monomer containing a monocyclic benzene unit and a monomer containing a conjugated Ar unit are mixed and polymerized under the catalysis of a catalyst to obtain the conjugated polymer.

[0011] Furthermore, the dibromo monomer based on the monocyclic benzene is selected from one of the following structures:

[0012] Furthermore, the monomer containing the conjugated Ar unit is selected from compounds containing any of the aforementioned Ar structures.

[0013] Furthermore, the molar ratio of the dibromo monomer containing monocyclic benzene to the monomer containing the conjugated Ar unit is 1:0.1 to 1:10.

[0014] Furthermore, the catalyst is a palladium catalyst.

[0015] Furthermore, the polymerization reaction is carried out at a temperature of 100-150°C, for a reaction time of 2-48 hours, and at a stirring rate of 200-1500 rpm.

[0016] Furthermore, the mixing method is physical mixing; the polymerization reaction uses one or more mixed solvents selected from tetrahydrofuran, toluene, o-xylene, chlorobenzene, N,N-dimethylformamide, etc.; the purification method includes one or more of filtration, column chromatography, extraction and dialysis.

[0017] This invention also provides a perovskite optoelectronic device based on a type of conjugated polymer based on monocyclic benzene, as described above. The optoelectronic device includes a perovskite solar cell, a perovskite photodetector, or a perovskite light-emitting diode. It comprises a substrate, a transparent conductive cathode, a hole transport layer, an electron transport layer, an active layer, and a metal electrode.

[0018] The substrate is a flexible or rigid transparent substrate; the transparent conductive cathode is one of indium tin oxide, fluorine-doped tin oxide, or aluminum-doped zinc oxide; the electron transport layer material is one or more of metal oxide semiconductors such as TiO2, SnO2, or ZnO, with a thickness of 10-100 nm; the perovskite photoactive layer material is one or more of high-efficiency perovskite active layers such as CH3NH3PbI3, HC(NH2)2PbI3, or CsPbI3, with a thickness of 200-1000 nm; the conjugated polymer based on monocyclic benzene is used as the hole transport layer material, with a hole transport layer thickness of 10-100 nm; the metal anode is one or more of metal conductors such as silver, gold, or aluminum, with a thickness of 80-150 nm.

[0019] The fabrication method of this device includes the following steps: (1) The transparent conductive substrate is ultrasonically cleaned in sequence with detergent, acetone, deionized water and isopropanol, and then dried for later use. The substrate is a flexible or rigid transparent substrate, and the transparent conductive cathode is one of indium tin oxide, fluorine-doped tin oxide or aluminum-doped zinc oxide. (2) Spin-coat an electron transport layer onto the substrate with spin-coating parameters of 2500~3500 rpm and 25~35 s, followed by annealing at 110~130℃ for 10~20 minutes. The concentration of the electron transport layer material is 0.1~20 mg / mL.

[0020] (3) In an inert atmosphere glove box, spin-coat the perovskite precursor solution (concentration 500 mg / mL, it is recommended to give a suitable range of values) onto the electron transport layer with parameters of 3500~4500 rpm and 20~40 s, and then anneal at 110~130℃ for 10~20 minutes to form a perovskite photoactive layer. (4) Spin-coat the hole transport layer solution based on monocyclic benzene onto the perovskite layer with a concentration of 0.1~20 mg / mL, a spin-coating speed of 1000~5000 rpm, a spin-coating time of 20~60 s, and anneal at 60~150℃ for 10~20 minutes after spin-coating to form a hole transport layer. (5) Deposit a metal anode (such as silver, gold or aluminum) on the hole transport layer with a thickness of 100~200 nm to complete the device fabrication.

[0021] Compared with the prior art, the beneficial effects of the present invention are: (1) The polymer of the present invention is a planar conjugated structure material with high hole mobility, excellent solubility, good flexibility and stretchability, and characteristic near-ultraviolet absorption characteristics. It can reduce light competition with the perovskite active layer and is suitable for replacing existing hole transport materials to meet the fabrication requirements of large-area perovskite optoelectronic devices.

[0022] (2) Hole transport layer based on this polymer can achieve excellent performance without additional doping and has good compatibility with flexible substrates. This characteristic is significantly better than that of traditional small molecule transport materials.

[0023] (3) The polymer material has excellent air stability and water and oxygen barrier capabilities. Its planar molecular structure can effectively inhibit ion migration and slow down the erosion of the perovskite layer by water and oxygen, thereby greatly improving the long-term working stability and service life of perovskite solar cells, photodetectors and other devices. Attached Figure Description

[0024] Figure 1 This is the absorption spectrum of a conjugated polymer based on a monocyclic benzene ring.

[0025] Figure 2 This is a schematic diagram of a perovskite solar cell device.

[0026] Figure 3 The voltage-current density curves are shown for perovskite solar cells based on different polymer hole transport layers. Detailed Implementation

[0027] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments, but the implementation and protection of the present invention are not limited thereto. It should be noted that any processes not specifically described in detail below are those that can be implemented or understood by those skilled in the art by referring to the prior art.

[0028] The present invention can be practiced using conventional techniques in polymer chemistry within the relevant field. In the following examples, efforts have been made to ensure the accuracy of the figures used (including quantities, temperatures, reaction times, etc.), but some experimental errors and deviations should be considered. Temperatures used in the following examples are expressed in °C, and pressures are at or near atmospheric pressure. All solvents used are of analytical or chromatographic purity, and all reactions are carried out in an inert gas atmosphere. Unless otherwise stated, all reagents are commercially available.

[0029] Example 1 Preparation of monomer M1:

[0030] The synthesis route is as follows:

[0031] (1) Synthesis of intermediate 2 Under nitrogen protection, compound 1 (2.04 g, 6.15 mmol) was dissolved in a suitable amount of dichloromethane, and boron tribromide (6.16 g, 24.58 mmol) was slowly added. After stirring at 50 °C for 24 hours, the mixture was added dropwise to deionized water and extracted with ethyl acetate. The mixture was then slurried in n-hexane, and the intermediate was collected for further reaction. Under nitrogen protection, the intermediate and potassium hydroxide (1.03 g, 18.44 mmol) were dissolved in anhydrous dimethyl sulfoxide (5 mL), and 2-ethylhexyl bromide (7.12 g, 36.87 mmol) was added. The mixture was stirred at room temperature for 48 hours. The mixture was poured into deionized water and extracted with dichloromethane. The combined organic layers were dried, the solvent was removed, and the crude product was purified by column chromatography (silica gel) with petroleum ether as eluent to give a colorless oil. The product was frozen at -20 °C for 2 hours to obtain a white solid (1.95 g, 60% yield).

[0032] (2) Synthesis of intermediate 3 To an anhydrous N,N-dimethylformamide solution of compound 2 (1.20 g, 2.27 mmol) and tributyl(2-thienyl)tin (3.39 g, 9.09 mmol), a catalyst of tetrakis(triphenylphosphine)palladium (22.7 mg, 0.23 mmol) was added. The mixture was heated to 120 °C and stirred overnight. The reaction was quenched with water, then extracted, concentrated, dried, and separated by column chromatography to give a colorless crystalline solid (1.21 g, 92% yield).

[0033] (3) Synthesis of monomer M1 Intermediate 3 (1.17 g, 2.19 mmol) was added to a dry reaction flask, dissolved in chloroform, and N-bromosuccinimide (778.9 mg, 4.38 mmol) was slowly added in portions at 0°C in the dark. The temperature was slowly raised to room temperature, and the reaction extent was monitored by thin-layer chromatography. After the reaction was completed, water was added to quench the reaction, followed by extraction, concentration, drying, and column chromatography to obtain white crystals M1 with a yield of 90%.

[0034] Example 2 Preparation of monomer M2:

[0035] The synthesis route is as follows:

[0036] (1) Synthesis of intermediate 4 Under nitrogen protection, compound 1 (1.00 g, 3.01 mmol) was dissolved in a suitable amount of dichloromethane, and boron tribromide (3.77 g, 15.06 mmol) was slowly added. After stirring at 50 °C for 24 hours, the mixture was added dropwise to deionized water and extracted with ethyl acetate. The mixture was then slurried in n-hexane, and the intermediate was collected for further reaction. Under nitrogen protection, the intermediate and potassium hydroxide (0.68 g, 12.05 mmol) were dissolved in anhydrous dimethyl sulfoxide (5 mL), and dodecane bromo (3.00 g, 12.05 mmol) was added. The mixture was stirred at room temperature for 48 hours. The mixture was poured into deionized water and extracted with dichloromethane. The combined organic layers were dried, the solvent was removed, and the crude product was purified by column chromatography (silica gel) using petroleum ether as eluent to give a colorless oil (1.25 g, 65% yield).

[0037] (2) Synthesis of intermediate 5 To an anhydrous N,N-dimethylformamide solution of compound 4 (1.25 g, 1.95 mmol) and tributyl(2-thienyl)tin (1.82 g, 4.88 mmol), a catalyst of tetrakis(triphenylphosphine)palladium (45.10 mg, 0.04 mmol) was added. The mixture was heated to 120 °C and stirred overnight. The reaction was quenched with water, then extracted, concentrated, dried, and separated by column chromatography to give a colorless crystalline solid (1.14 g, 90% yield).

[0038] (3) Synthesis of monomer M2 Intermediate 5 (1.14 g, 1.76 mmol) was added to a dry reaction flask, dissolved in chloroform, and N-bromosuccinimide (658.59 mg, 3.70 mmol) was slowly added in portions at 0°C in the dark. The temperature was slowly raised to room temperature, and the reaction extent was monitored by thin-layer chromatography. After the reaction was completed, water was added to quench the reaction, followed by extraction, concentration, drying, and column chromatography separation to obtain white crystals M2 with a yield of 90%.

[0039] Example 3 Preparation of monomer M3:

[0040] The synthesis route is as follows:

[0041] (1) Synthesis of intermediate 6 Under nitrogen protection, compound 1 (1.00 g, 3.01 mmol) was dissolved in a suitable amount of dichloromethane, and boron tribromide (3.7 g, 15.06 mmol) was slowly added. After stirring at 50 °C for 24 hours, the mixture was added dropwise to deionized water and extracted with ethyl acetate. The mixture was then slurried in n-hexane, and the intermediate was collected for further reaction. Under nitrogen protection, the intermediate and potassium hydroxide (0.68 g, 12.05 mmol) were dissolved in anhydrous dimethyl sulfoxide (5 mL), and 1-bromo-3-ethylheptane (2.50 g, 12.05 mmol) was added. The mixture was stirred at room temperature for 48 hours. The mixture was poured into deionized water and extracted with dichloromethane. The combined organic layers were dried, the solvent was removed, and the crude product was purified by column chromatography (silica gel) with petroleum ether as eluent to give a colorless oil (1.14 g, 68% yield).

[0042] (2) Synthesis of intermediate 7 To an anhydrous N,N-dimethylformamide solution of compound 6 (1.14 g, 2.05 mmol) and tributyl(2-thienyl)tin (1.91 g, 5.12 mmol), a catalyst of tetrakis(triphenylphosphine)palladium (47.36 mg, 0.04 mmol) was added. The mixture was heated to 120 °C and stirred overnight. The reaction was quenched with water, then extracted, concentrated, dried, and separated by column chromatography to give a colorless crystalline solid (1.04 g, 90% yield).

[0043] (3) Synthesis of monomer M3 Intermediate 5 (1.04 g, 1.85 mmol) was added to a dry reaction flask, dissolved in chloroform, and N-bromosuccinimide (690.66 mg, 3.88 mmol) was slowly added in portions at 0°C in the dark. The temperature was slowly raised to room temperature, and the reaction extent was monitored by thin-layer chromatography. After the reaction was completed, water was added to quench the reaction, followed by extraction, concentration, drying, and column chromatography separation to obtain white crystals M3 with a yield of 95%.

[0044] Example 4 Preparation of monomer M4:

[0045] The synthesis route is as follows:

[0046] (1) Synthesis of intermediate 8 Under nitrogen protection, compound 1 (2.04 g, 6.15 mmol) was dissolved in a suitable amount of dichloromethane, and boron tribromide (6.16 g, 24.58 mmol) was slowly added. After stirring at 50 °C for 24 hours, the mixture was added dropwise to deionized water and extracted with ethyl acetate. The mixture was then slurried in n-hexane, and the intermediate was collected for further reaction. Under nitrogen protection, the intermediate and potassium hydroxide (1.03 g, 18.44 mmol) were dissolved in anhydrous dimethyl sulfoxide (5 mL), and 2-ethylhexyl bromide (5.63 g, 18.44 mmol) was added. The mixture was stirred at room temperature for 48 hours. The mixture was poured into deionized water and extracted with dichloromethane. The combined organic layers were dried, the solvent was removed, and the crude product was purified by column chromatography (silica gel) with petroleum ether as eluent to give a colorless oily product (2.78 g, 60% yield).

[0047] (2) Synthesis of intermediate 9 To an anhydrous N,N-dimethylformamide solution of compound 2 (2.78 g, 3.69 mmol) and tributyl(2-thienyl)tin (3.45 g, 9.23 mmol), a catalyst of tetrakis(triphenylphosphine)palladium (85.35 mg, 0.07 mmol) was added. The mixture was heated to 120 °C and stirred overnight. The reaction was quenched with water, then extracted, concentrated, dried, and separated by column chromatography to give a colorless oily liquid 9 (2.58 g, 92% yield).

[0048] (3) Synthesis of monomer M4 Intermediate 3 (2.58 g, 3.40 mmol) was added to a dry reaction flask, dissolved in chloroform, and N-bromosuccinimide (1.13 mg, 7.48 mmol) was slowly added in portions at 0°C in the dark. The temperature was slowly raised to room temperature, and the reaction was monitored by thin-layer chromatography. After the reaction was completed, water was added to quench the reaction, followed by extraction, concentration, drying, and column chromatography to obtain a colorless oily liquid M4 (3.12 g, 99% yield).

[0049] Example 5 As an example, the structural formula of the conjugated polymer P1 based on M1 is shown below:

[0050] The synthesis route is as follows:

[0051] (1) The monomer M5, catalyst tetra(triphenylphosphine)palladium, o-xylene and N,N-dimethylformamide were all purchased from commercial channels.

[0052] (2) Preparation of polymer P1 Under nitrogen protection, M5 (94.25 mg, 0.10 mmol) and M1 (70.00 mg, 0.10 mmol) were dissolved in a mixed solvent of anhydrous o-xylene (1.8 mL) and N,N-dimethylformamide (0.2 mL), and tetrakis(triphenylphosphine)palladium (2.34 mg, 0.002 mmol) was added. The reaction temperature was 120 °C, and the polymerization time was 48 hours. After cooling to room temperature, the reaction mixture precipitated in methanol. The polymer was subjected to Soxhlet extraction with methanol, acetone, hexane, dichloromethane, and chloroform in sequence under nitrogen protection. The residue was dissolved in hot chlorobenzene and filtered. The chlorobenzene fraction was concentrated under reduced pressure to precipitate methanol, and the precipitate was dried under vacuum to give bright red polymer P1 (117 mg, 99%).

[0053] Example 6 As an example, the structural formula of the conjugated polymer P2 based on M1 is shown below:

[0054] The synthesis route is as follows:

[0055] (1) The monomer M6, catalyst tetra(triphenylphosphine)palladium, o-xylene and N,N-dimethylformamide were all purchased from commercial channels.

[0056] (2) Preparation of polymer P2 Under nitrogen protection, M6 (91.00 mg, 0.10 mmol) and M1 (69.67 mg, 0.10 mmol) were dissolved in a mixed solvent of anhydrous o-xylene (1.8 mL) and N,N-dimethylformamide (0.2 mL), and tetrakis(triphenylphosphine)palladium (2.34 mg, 0.002 mmol) was added. The reaction temperature was 120 °C, and the polymerization time was 48 hours. After cooling to room temperature, the reaction mixture precipitated in methanol. The polymer was subjected to Soxhlet extraction with methanol, acetone, hexane, dichloromethane, and chloroform in sequence under nitrogen protection. The residue was dissolved in hot chlorobenzene and filtered. The chlorobenzene fraction was concentrated under reduced pressure to precipitate methanol, and the precipitate was dried under vacuum to give bright red polymer P2 (114 mg, 99%).

[0057] Example 7 As an example, the structural formula of the M2-based conjugated polymer P3 is shown below:

[0058] The synthesis route is as follows:

[0059] (1) The monomer M5, catalyst tetra(triphenylphosphine)palladium, o-xylene and N,N-dimethylformamide were all purchased from commercial channels.

[0060] (2) Preparation of polymer P1 Under nitrogen protection, M5 (94.25 mg, 0.10 mmol) and M2 (70.00 mg, 0.10 mmol) were dissolved in a mixed solvent of anhydrous o-xylene (1.8 mL) and N,N-dimethylformamide (0.2 mL), and tetrakis(triphenylphosphine)palladium (2.34 mg, 0.002 mmol) was added. The reaction temperature was 120 °C, and the polymerization time was 6 hours. After cooling to room temperature, the reaction mixture precipitated in methanol. The polymer was subjected to Soxhlet extraction with methanol, acetone, hexane, dichloromethane, and chloroform under nitrogen protection. The residue was dissolved in hot chlorobenzene and filtered. The chlorobenzene fraction was concentrated under reduced pressure to precipitate methanol, and the precipitate was dried under vacuum to give bright red polymer P3 (112.00 mg, 98%).

[0061] Example 8 As an example, the structural formula of the M2-based conjugated polymer P4 is shown below:

[0062] The synthesis route is as follows:

[0063] (1) The monomer M6, catalyst tetra(triphenylphosphine)palladium, o-xylene and N,N-dimethylformamide were all purchased from commercial channels.

[0064] (2) Preparation of polymer P2 Under nitrogen protection, M6 (91.00 mg, 0.10 mmol) and M2 (69.67 mg, 0.10 mmol) were dissolved in a mixed solvent of anhydrous o-xylene (1.8 mL) and N,N-dimethylformamide (0.2 mL), and tetrakis(triphenylphosphine)palladium (2.34 mg, 0.002 mmol) was added. The reaction temperature was 120 °C, and the polymerization time was 24 hours. After cooling to room temperature, the reaction mixture precipitated in methanol. The polymer was subjected to Soxhlet extraction with methanol, acetone, hexane, dichloromethane, and chloroform under nitrogen protection. The residue was dissolved in hot chlorobenzene and filtered. The chlorobenzene fraction was concentrated under reduced pressure to precipitate methanol, and the precipitate was dried under vacuum to give the bright red polymer P4 (110.00 mg, 97%).

[0065] Example 9 As an example, the structural formula of the M3-based conjugated polymer P5 is shown below:

[0066] The synthesis route is as follows:

[0067] (1) The monomer M5, catalyst tetra(triphenylphosphine)palladium, o-xylene and N,N-dimethylformamide were all purchased from commercial channels.

[0068] (2) Preparation of polymer P5 Under nitrogen protection, M5 (94.25 mg, 0.10 mmol) and M1 (70.00 mg, 0.10 mmol) were dissolved in a mixed solvent of anhydrous o-xylene (1.8 mL) and N,N-dimethylformamide (0.2 mL), and tetrakis(triphenylphosphine)palladium (2.34 mg, 0.002 mmol) was added. The reaction temperature was 120 °C, and the polymerization time was 48 hours. After cooling to room temperature, the reaction mixture precipitated in methanol. The polymer was subjected to Soxhlet extraction with methanol, acetone, hexane, dichloromethane, and chloroform in sequence under nitrogen protection. The residue was dissolved in hot chlorobenzene and filtered. The chlorobenzene fraction was concentrated under reduced pressure to precipitate methanol, and the precipitate was dried under vacuum to give bright red polymer P5 (117 mg, 99%).

[0069] Example 10 As an example, the structural formula of the M3-based conjugated polymer P6 is shown below:

[0070] The synthesis route is as follows:

[0071] (1) The monomer M6, catalyst tetra(triphenylphosphine)palladium, o-xylene and N,N-dimethylformamide were all purchased from commercial channels.

[0072] (2) Preparation of polymer P6 Under nitrogen protection, M6 (91.00 mg, 0.10 mmol) and M1 (69.67 mg, 0.10 mmol) were dissolved in a mixed solvent of anhydrous o-xylene (1.8 mL) and N,N-dimethylformamide (0.2 mL), and tetrakis(triphenylphosphine)palladium (2.34 mg, 0.002 mmol) was added. The reaction temperature was 120 °C, and the polymerization time was 24 hours. After cooling to room temperature, the reaction mixture precipitated in methanol. The polymer was subjected to Soxhlet extraction with methanol, acetone, hexane, dichloromethane, and chloroform under nitrogen protection. The residue was dissolved in hot chlorobenzene and filtered. The chlorobenzene fraction was concentrated under reduced pressure to precipitate methanol, and the precipitate was dried under vacuum to give bright red polymer P6 (114 mg, 99%).

[0073] Example 11 As an example, the structural formula of the M4-based conjugated polymer P7 is shown below:

[0074] The synthesis route is as follows:

[0075] (1) The polymer monomer M7, catalyst tetra(triphenylphosphine)palladium, o-xylene and N,N-dimethylformamide were all purchased from commercial channels.

[0076] (2) Preparation of polymer P7 Under nitrogen protection, M7 (100.00 mg, 0.22 mmol) and M4 (205.73 mg, 0.22 mmol) were dissolved in a mixed solvent of anhydrous o-xylene (4.0 mL) and N,N-dimethylformamide (0.4 mL), and tetrakis(triphenylphosphine)palladium (4.68 mg, 0.004 mmol) was added. The reaction temperature was 120 °C, and the polymerization time was 24 hours. After cooling to room temperature, the reaction mixture precipitated in methanol. The polymer was subjected to Soxhlet extraction with methanol, acetone, hexane, dichloromethane, and chloroform under nitrogen protection. The residue was dissolved in hot chlorobenzene and filtered. The chlorobenzene fraction was concentrated under reduced pressure to precipitate methanol, and the precipitate was dried under vacuum to give bright red polymer P7 (200 mg, 98%).

[0077] Example 12 As an example, the structural formula of the M4-based conjugated polymer P8 is shown below:

[0078] The synthesis route is as follows:

[0079] (1) The monomer M8, catalyst tetra(triphenylphosphine)palladium, o-xylene and potassium carbonate were all purchased from commercial channels.

[0080] (2) Preparation of polymer P8 Under nitrogen protection, M8 (100.00 mg, 0.27 mmol) and M4 (250.53 mg, 0.27 mmol) were dissolved in a mixed solvent of anhydrous o-xylene (5 mL) and potassium carbonate aqueous solution (2 mmol / mL, 0.2 mL), and tetrakis(triphenylphosphine)palladium (2.34 mg, 0.002 mmol) was added. The reaction temperature was 120 °C, and the polymerization time was 48 hours. After cooling to room temperature, the reaction mixture precipitated in methanol. The polymer was subjected to Soxhlet extraction with methanol, acetone, hexane, dichloromethane, and chloroform under nitrogen protection. The residue was dissolved in hot chlorobenzene and filtered. The chlorobenzene fraction was concentrated under reduced pressure to precipitate methanol, and the precipitate was dried under vacuum to give red polymer P8 (245 mg, 99%).

[0081] Example 13 As an example, the structural formula of the M4-based conjugated polymer P9 is shown below:

[0082] The synthesis route is as follows:

[0083] (1) The monomer M9, catalyst tetra(triphenylphosphine)palladium, o-xylene and potassium carbonate were all purchased from commercial channels.

[0084] (2) Preparation of polymer P9 Under nitrogen protection, M9 (100.00 mg, 0.26 mmol) and M4 (241.25 mg, 0.26 mmol) were dissolved in a mixed solvent of anhydrous o-xylene (5 mL) and potassium carbonate aqueous solution (2 mmol / mL, 0.2 mL), and tetrakis(triphenylphosphine)palladium (2.34 mg, 0.002 mmol) was added. The reaction temperature was 120 °C, and the polymerization time was 24 hours. After cooling to room temperature, the reaction mixture precipitated in methanol. The polymer was subjected to Soxhlet extraction with methanol, acetone, hexane, dichloromethane, and chloroform under nitrogen protection. The residue was dissolved in hot chlorobenzene and filtered. The chlorobenzene fraction was concentrated under reduced pressure to precipitate methanol, and the precipitate was dried under vacuum to obtain bright red polymer P9 (240 mg, 99%).

[0085] Example 14 As an example, the above-mentioned conjugated polymer based on monocyclic benzene was used as a hole transport layer to prepare a perovskite solar cell. Figure 1 The absorption curves for polymers P1 to P9 are shown. The device structure is as follows. Figure 2 As shown, the specific preparation process is as follows: The transparent conductive cathode (such as indium tin oxide, fluorine-doped tin oxide, or aluminum-doped zinc oxide) was ultrasonically cleaned with methanol, acetone, isopropanol, or ethanol, and then dried in an oven. An electron transport layer (materials such as TiO2, SnO2, or ZnO, with a thickness of 10-100 nm) was prepared on the transparent conductive cathode. Subsequently, a perovskite photoactive layer (materials such as CH3NH3PbI3, HC(NH2)2PbI3, or CsPbI3, with a thickness of 200-1000 nm) was formed on the electron transport layer by spin coating. A solution of the monocyclic benzene-based conjugated polymers P1-P9 prepared in the above examples was spin-coated onto the perovskite photoactive layer as a hole transport layer. The concentration of the polymer solution was 15-25 mg / mL, the spin coating speed was 1000-5000 rpm, and the spin coating time was 20-60 minutes. After spin coating, the hole transport layer is annealed at 60-150℃ for 10-20 minutes, resulting in a hole transport layer thickness of 10-100 nm. Finally, a metal anode (materials such as silver, gold, or aluminum, with a thickness of 80-150 nm) is deposited onto the hole transport layer by vapor deposition. Voltage-current density curve testing is then performed. Figure 3 The test data are shown in Table 1 below. Table 1 is a performance parameter table of perovskite solar cells based on the polymer hole transport layer and the reference hole transport layer (Spiro-OMeTAD, PTAA, P3HT).

[0086] Table 1. Device parameters of perovskite solar cells based on different hole transport layers

[0087] like Figure 1 As shown, the absorption range of polymers P1 to P9 is within 300. Between 600 nm and 600 nm, parasitic absorption in the visible light region can be effectively reduced. Meanwhile, polymer P1~P9 films exhibit obvious 0-0 absorption peaks, indicating that these polymers possess strong intermolecular interactions and ordered molecular stacking in the solid state, meeting the basic requirements for a hole transport layer. Table 1 and... Figure 3 Data shows that the hole mobility of polymers P1 to P9 is 1.0. 5.5×10 -3 cm 2 V -1 s -1 Compared to Spiro-OMeTAD (0.2×10), -4 cm 2 V -1 s -1 ), PTAA (0.2×10) -4 cm 2 V -1 s-1 ) and P3HT (0.2×10 -4 cm 2 V -1 s -1 The efficiency was increased by an order of magnitude, indicating that the conjugated polymers of this invention possess superior hole transport performance. Therefore, the perovskite solar cells fabricated using polymers P1-P9 as the hole transport layer achieved a photoelectric conversion efficiency of 27.10%. With an efficiency of 28.99%, significantly higher than photovoltaic devices based on Spiro-OMeTAD (21.68%), PTAA (22.17%), and P3HT (21.45%), it is one of the most efficient perovskite solar cell systems currently available.

[0088] The above embodiments are merely preferred embodiments of the present invention and are used only to explain the present invention, not to limit the present invention. Any changes, substitutions, modifications, etc., made by those skilled in the art without departing from the spirit and essence of the present invention should fall within the protection scope of the present invention.

Claims

1. A class of conjugated polymers based on monocyclic benzene, characterized in that, It has a general structural formula as shown in Equation I: Formula I R1 and R2 are independently selected from any one of straight-chain or branched alkyl groups having 1-30 carbon atoms, alkoxy groups, ester groups, acyloxy groups, aryl groups, aralkyl groups, haloalkyl groups, heteroalkyl groups, or combinations thereof that are substituted with substituents. X is selected from any one of fluorine, chlorine, bromine, and iodine; Ar is selected from any of the following groups: a) substituted or unsubstituted benzene, substituted or unsubstituted thiophene, substituted or unsubstituted furan, or substituted or unsubstituted selenophene; b) An aromatic fused ring formed by any two identical or different groups in a) connected by a fused ring or bridging atoms; c) A conjugated system formed by direct covalent bonding of the groups described in a) and / or b); Wherein, the substituents in the substituted benzene, substituted thiophene, substituted furan and substituted selenophene are independently hydrogen atoms, fluorine atoms, alkyl, alkoxy, alkylthio, aralkyl, heterocyclic aralkyl, acyl, acyloxy, acylthio, ester, amino, amide, alkenyl, alkynyl, carboxyl or cyano, wherein the alkyl contained in the alkyl, alkoxy, alkylthio, aralkyl and heterocyclic aralkyl are straight-chain or branched alkyl with 1-25 carbon atoms; n represents the number of repeating units in the conjugated polymer, and n is selected from a natural number between 5 and 1000.

2. The conjugated polymer based on monocyclic benzene according to claim 1, characterized in that, Ar is one of thiophene, furan, selenophene, benzene, fluorene, carbazole, silylfluorene, benzodithiophene, benzodiselenophene, benzodifuran, benzothiadiazole, phenothiazine, phenothiazine, bithiophene, thiophene, thiophene-cyclopentadiene, thiophene-pyrrole, thiophene-thiorrole, indolefluorene, indolecarbazole, pyrrole, pyrrolopyrroledione, naphthimide, peryleneimide, and derivatives of the structures described above.

3. The conjugated polymer based on monocyclic benzene according to claim 1, characterized in that, Ar can be one or more of the following coupling structures: Where Y is selected from any one of oxygen, sulfur, and selenium; The R3-R6 groups are independently selected from any one of hydrogen, fluorine atom, chlorine atom, substituted or unsubstituted C1-C30 alkyl, substituted or unsubstituted C1-C30 alkoxy, substituted or unsubstituted C1-C30 alkyl, substituted or unsubstituted C1-C30 ester, substituted or unsubstituted C6-C30 aryl, or substituted or unsubstituted C4-C30 heteroaryl.

4. The method for preparing the conjugated polymer based on monocyclic benzene according to any one of claims 1-3, characterized in that, Includes the following steps: A dibromo monomer containing a monocyclic benzene unit and a monomer containing a conjugated Ar unit are mixed and polymerized under the catalysis of a catalyst to obtain the conjugated polymer.

5. The preparation method according to claim 4, characterized in that, The monomer containing the monocyclic benzene dibromo unit is selected from one of the following structures: The monomer containing the conjugated Ar unit is selected from compounds containing any of the Ar structures described in claim 3.

6. The preparation method according to claim 4, characterized in that, The molar ratio of the dibromo monomer containing monocyclic benzene to the monomer containing the conjugated Ar unit is 1:0.1 to 1:

10.

7. The preparation method according to claim 4, characterized in that, The catalyst is a palladium catalyst; the polymerization reaction temperature is 100~150℃, the reaction time is 2~48h, and the stirring rate is 200~1500 rpm.

8. A perovskite solar cell, comprising, from bottom to top, a substrate, a transparent conductive cathode, an electron transport layer, a perovskite photoactive layer, a hole transport layer, and a metal anode, characterized in that, The hole transport layer is prepared from the monocyclic benzene-based conjugated polymer as described in any one of claims 1-3.

9. The perovskite solar cell according to claim 8, characterized in that, The substrate is a flexible or rigid transparent substrate; the transparent conductive cathode is one of indium tin oxide, fluorine-doped tin oxide, or aluminum-doped zinc oxide; the electron transport layer material is one or more of TiO2, SnO2, or ZnO, with a thickness of 10-100 nm; the perovskite photoactive layer material is one or more of CH3NH3PbI3, HC(NH2)2PbI3, or CsPbI3, with a thickness of 200-1000 nm; the conjugated polymer based on monocyclic benzene is used as the hole transport layer material, with a thickness of 10-100 nm; the metal anode is one or more of silver, gold, or aluminum, with a thickness of 80-150 nm.

10. The method for preparing a perovskite solar cell according to claim 8, characterized in that, Includes the following steps: The hole transport layer is formed by coating the perovskite photoactive layer with a solution-processed conjugated polymer solution containing monocyclic benzene. The concentration of the polymer solution is 0.1~20 mg / mL, the spin coating speed is 1000~5000 rpm, the spin coating time is 20~60 s, and the spin coating is annealed at 60~150℃ for 10~20 minutes after spin coating.

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