Perovskite cell and preparation method thereof, photovoltaic module and photovoltaic system

Abstract

The application relates to the technical field of solar cells, in particular to a perovskite cell, a preparation method thereof, a photovoltaic module and a photovoltaic system. The perovskite cell comprises a substrate and a perovskite active layer located on the surface of the substrate, the perovskite active layer comprises an additive, the additive is a twisted conjugated molecule, and the molecular structure comprises at least one conjugated group and at least one carboxyl group. The perovskite cell has high photoelectric conversion efficiency.

Description

Technical Field

[0001] This invention relates to the field of solar cell technology, specifically to a perovskite solar cell and its preparation method, photovoltaic module, and photovoltaic system. Background Technology

[0002] Perovskite solar cells are considered one of the core directions of next-generation photovoltaic technology due to their high photoelectric conversion efficiency, low cost, and flexible fabrication capabilities. Perovskite cells typically employ a "sandwich" structure, where photogenerated carriers must be transported from the perovskite thin film layer to the charge transport layer (ETL / HTL) and electrodes. The quality of the perovskite active layer directly determines the device's performance and stability. However, in actual production, insufficient wettability of the perovskite solution on large-area substrates (such as SnO2 / FTO, nickel oxide hole transport layers, etc.) often leads to problems such as inhomogeneous perovskite films, large differences in grain distribution, and frequent porosity defects, severely restricting the improvement of device efficiency and large-scale application.

[0003] Therefore, developing new perovskite solar cells with high photoelectric conversion efficiency is of great significance. Summary of the Invention

[0004] The perovskite solar cell provided by this invention has a high photoelectric conversion efficiency.

[0005] The photovoltaic module provided by this invention has a high photoelectric conversion efficiency.

[0006] The photovoltaic system provided by this invention has a high photoelectric conversion efficiency.

[0007] The perovskite battery provided by the present invention includes a perovskite active layer, wherein the perovskite active layer includes an additive, the additive being a twisted conjugated molecule, and the molecular structure containing at least one conjugated group and at least one carboxyl group.

[0008] In the perovskite battery described above, the conjugated group includes at least one of phenyl, triphenylamino, biphenyl, naphthyl, or anthracene.

[0009] In the perovskite battery described above, the carboxyl group and the conjugated group are connected by a single bond or a carbon chain, and the carbon chain has 1-4 carbon atoms.

[0010] In the perovskite battery described above, the conjugated groups include phenyl and triphenylamine groups, wherein the carbon atom of the benzene ring opposite to the nitrogen atom in the triphenylamine group is replaced by a phenyl group; and the carbon atom of the phenyl group opposite to the carbon atom connected to the triphenylamine group is replaced by a carboxyl group.

[0011] Based on the perovskite battery described above, the general molecular structure of the additive is shown in formula (1) below:

[0012] Equation (1);

[0013] R1, R2, R3, and R4 are each independently selected from at least one of H, halogen atom, C1-C20 alkyl, C6-C30 aryl, and C6-C30 heteroaryl.

[0014] In the perovskite battery described above, the additive is selected from at least one of the following:

[0015] .

[0016] In the perovskite battery described above, the perovskite active layer includes perovskite material, and the mass of the additive is 0.06‰-3.84‰ of the mass of the perovskite material.

[0017] The perovskite solar cell described above, wherein the perovskite active layer comprises a perovskite thin film and a monolayer, the monolayer being located between the perovskite thin film and the substrate, and the monolayer comprising the aforementioned additives.

[0018] The present invention also provides a method for preparing the above-mentioned perovskite solar cell, comprising:

[0019] Prepare a perovskite precursor solution containing the perovskite material and the additives mentioned above.

[0020] The perovskite active layer was prepared on the substrate surface using a perovskite precursor solution to obtain the perovskite solar cell.

[0021] According to the above-described method for preparing perovskite solar cells, the concentration of the additive in the perovskite precursor solution is 0.05 mg / mL to 3 mg / mL, and the total concentration of the perovskite material is 0.8 mol / L to 1.5 mol / L.

[0022] The perovskite battery preparation method described above uses perovskite materials including lead halide salts, tin halide salts, and amine salts.

[0023] The present invention also provides a photovoltaic module, including the perovskite cell described above.

[0024] The present invention also provides a photovoltaic system, including the perovskite cell or the photovoltaic module described above.

[0025] The perovskite solar cell provided by this invention improves the photoelectric conversion efficiency of the cell by introducing an additive containing carboxyl groups and a twisted conjugated structure into the perovskite active layer. This additive can reduce defects such as pinholes, island nucleation, and uneven grain size distribution in the perovskite film. Attached Figure Description

[0026] Figure 1 The figures show the contact angle test results for Examples 1-6 and Comparative Examples 1-2;

[0027] Figure 2 The results of observations on the thin films formed from the perovskite precursor solutions in Examples 1-3 and Comparative Example 2;

[0028] Figure 3 The test results are for the perovskite solar cells prepared from the perovskite precursor solutions in Examples 1-6 and Comparative Example 2.

[0029] Figure 4 The results are for the test of the perovskite solar cells prepared in Examples 7-10.

[0030] Figure 5 The results are the test results of the perovskite solar cells prepared from the perovskite precursor solutions in Example 11 and Comparative Example 2. Detailed Implementation

[0031] To enable those skilled in the art to better understand the solutions of this invention, the following provides a further detailed description of this application. The specific embodiments listed below are merely descriptions of the principles and features of this invention; the examples are only for explaining the invention and are not intended to limit its scope. Based on the embodiments of this invention, other embodiments obtained by those skilled in the art without creative effort are all within the scope of protection of this invention.

[0032] In the fabrication of perovskite solar cells, the film quality of the perovskite precursor solution directly determines the performance and stability of the device. The film quality of the perovskite thin film largely depends on the wetting and spreading behavior of the precursor solution on the substrate surface. However, in the conventional fabrication process of perovskite solar cells, the precursor solution often uses a highly polar solvent system (such as DMF, DMSO, GBL, etc.), while the substrate surface (such as tin oxide or organic hole transport layer) is usually a low-polarity or hydrophobic material. The significant difference in surface energy between the two leads to insufficient wettability of the solution on the substrate. This mismatch in wettability causes uneven solution spreading, resulting in defects such as pinholes, island nucleation, and uneven grain size distribution during film formation.

[0033] Based on this, the present invention provides a perovskite battery, including a perovskite active layer, wherein the perovskite active layer includes an additive, the additive being a twisted conjugated molecule, and its molecular structure containing at least one conjugated group and at least one carboxyl group.

[0034] The perovskite solar cell provided by this invention improves the photoelectric conversion efficiency of the cell by introducing an additive containing carboxyl groups and a twisted conjugated structure into the perovskite active layer. This additive can reduce defects such as pinholes, island nucleation, and uneven grain size distribution in the perovskite film.

[0035] The detailed reasons are as follows: During the film formation process, the carboxyl groups in the additive can form hydrogen bonds or coordination with the surface of the perovskite battery substrate (such as hydroxyl groups or metal oxides), reducing interfacial tension. At the same time, the twisted structure promotes a more uniform distribution of additive molecules in the solution, reducing intermolecular aggregation. This adjusts the polarity and rheological properties of the perovskite precursor solution, allowing the perovskite material in the perovskite precursor to be better dispersed during the film formation process. Consequently, the quality of the formed perovskite film is better, which is beneficial to improving the photoelectric conversion efficiency of the battery.

[0036] Twisted conjugated molecules refer to organic molecules in which there are conjugated systems in the molecular structure (such as delocalized π-electron structures such as alternating single and double bonds or aromatic rings), but the overall configuration is affected by factors such as steric hindrance, bond angle distortion, or non-coplanar substituents, which prevent the conjugated units from forming a completely coplanar geometric arrangement, thus presenting a three-dimensional twisted morphology.

[0037] Conjugated groups are specific groups formed in a molecule by continuous alternating single and double bonds (π bonds) or structural units such as aromatic rings and heteroaromatic rings with delocalized π electrons. Their core characteristic is that π electrons can be freely delocalized between multiple atoms. These groups include functional groups containing π bonds such as vinyl (-CH=CH-), carbonyl (C=O), and cyano (-C≡N) groups in simple alkenes, as well as aromatic or heteroaromatic systems, such as phenyl (C6H5-), biphenyl (formed by two benzene rings connected by a single bond), and naphthyl (C6H5-). 10 H7-, composed of two fused benzene rings), anthracene (C 14 H 10 - Polycyclic aromatic hydrocarbons (composed of three fused benzene rings) and heteroaromatic systems such as triphenylamine (an amine group formed by three benzene rings linked by nitrogen atoms) and thiophene (C4H3S-, a five-membered aromatic ring containing sulfur heteroatoms).

[0038] In this invention, the additive can be identified by nuclear magnetic resonance (NMR) or mass spectrometry (MS). Specifically, after disassembling the battery and separating the perovskite active layer, the presence of the additive can be confirmed by obtaining the unique chemical structure signal or molecular fragment signal of the additive through the above detection methods.

[0039] Different conjugated groups can further regulate the spreading ability, thereby improving the film quality. In some embodiments, the conjugated groups include at least one of phenyl, triphenylamino, biphenyl, naphthyl or anthracene.

[0040] In this invention, the carboxyl group can be connected to the conjugated group via a single bond or via a carbon chain. When connected via a carbon chain, the number of carbon atoms in the carbon chain is usually 1-4.

[0041] In some embodiments, the conjugated groups in the additive include phenyl and triphenylamine groups, wherein in the triphenylamine group, the carbon atom of the benzene ring opposite to the nitrogen atom is replaced by a phenyl group; and in the phenyl group, the carbon atom opposite to the carbon atom connected to the triphenylamine group is replaced by a carboxyl group. Studies have shown that additives with this structure can further improve the wetting and spreading ability of precursor solutions on substrates, thereby forming denser, more uniform perovskite films with fewer defects and improved photoelectric conversion efficiency.

[0042] In some embodiments, the general molecular structure of the additive is shown in formula (1) below:

[0043] Equation (1).

[0044] R1, R2, R3, and R4 are not specifically limited. For example, R1, R2, R3, and R4 can each be independently selected from at least one of -H, halogen atom, C1-C20 alkyl, C6-C30 aryl, and C6-C30 heteroaryl.

[0045] Specifically, halogen atoms include fluorine (F), chlorine (Cl), bromine (Br), iodine (I), etc.

[0046] C1-C20 alkyl groups refer to straight-chain or branched saturated hydrocarbon groups consisting of 1 to 20 carbon atoms, including methyl (-CH3), ethyl (-C2H5), n-propyl (-CH2CH2CH3), isopropyl (-CH(CH3)2), and higher straight-chain or branched alkyl groups (such as n-butyl, tert-butyl to eicosyl, etc.).

[0047] C6-C30 aryl groups include aromatic ring systems consisting of 6 to 30 carbon atoms, including monocyclic aryl (such as phenyl), bicyclic aryl (such as naphthyl, anthracene), tricyclic aryl (such as phenanthrene), and polycyclic fused aryl (such as tetraphenyl, pyrene).

[0048] C6-C30 heteroaryl groups include 6- to 30-membered aromatic heterocyclic groups containing at least one heteroatom (such as nitrogen, oxygen, sulfur, selenium, etc.), such as indole (-C8H6N), carbazole (-C... 12 H8N) and complex systems containing multiple heteroatoms (such as thiazolyl, pyrazinyl, benzothiophene, etc.).

[0049] For example, the additive may be selected from at least one of the following:

[0050]

[0051] In some embodiments, the perovskite active layer includes perovskite material, and the mass of the additive is 0.06‰-3.84‰ of the mass of the perovskite material. When the mass of the additive is above 0.06‰ of the mass of the perovskite material, it ensures that there is sufficient additive to improve the spreading and wetting effect, thereby better improving the film quality. When the mass of the additive is below 3.84‰ of the mass of the perovskite material, it ensures that there is more perovskite material in the active layer to play its role, thereby further ensuring a higher photoelectric conversion efficiency.

[0052] In some embodiments, the perovskite active layer includes a perovskite film and a monolayer, wherein the monolayer is located between the perovskite film and the substrate, and the monolayer includes the additives described above.

[0053] The monolayer formed by this additive enables energy level modulation, defect passivation, and hole extraction optimization at the interface between the substrate and the perovskite active layer, thereby further improving the photoelectric conversion efficiency of the battery.

[0054] The preparation method of the perovskite solar cell in this invention is not limited, and it can be prepared according to the preparation method of perovskite solar cells in the art. Compared with the existing technology of improving perovskite film formation through equipment modification or surface treatment, the preparation method of this perovskite solar cell can directly introduce the above-mentioned additives into the perovskite precursor solution without changing the original preparation process.

[0055] In some embodiments, the method for preparing the perovskite solar cell includes:

[0056] Prepare a perovskite precursor solution containing the perovskite material and the above-mentioned additives;

[0057] A perovskite active layer was fabricated on the substrate surface using a perovskite precursor solution to obtain a perovskite solar cell.

[0058] The above preparation method can be achieved without changing the traditional perovskite solar cell preparation process, and it is simple to operate.

[0059] In some embodiments, the concentration of the additive in the perovskite precursor solution is 0.05 mg / mL to 3 mg / mL, and the total concentration of the perovskite material is 0.8 mol / L to 1.5 mol / L. Specifically, this means that 0.05 mg to 3 mg of the additive and 0.8 mol to 1.5 mol of the perovskite material are added to 1 mL of the perovskite precursor solution. For example, the concentration of the additive can be 0.1 mg / mL, 0.2 mg / mL, 0.3 mg / mL, 0.4 mg / mL, 0.5 mg / mL, 0.6 mg / mL, 0.7 mg / mL, 0.8 mg / mL, 0.9 mg / mL, 1 mg / mL, or any two of the above values. The concentration of the perovskite material can be 0.8 mol / L, 1.0 mol / L, 1.2 mol / L, 1.5 mol / L, or any two of the above values. Controlling the concentrations of the additive and the perovskite material within these ranges helps to better ensure the wetting and spreading effect of the precursor solution.

[0060] It is also understandable that the perovskite precursor solution also includes solvents such as N,N-dimethylformamide (DMF), dimethyl sulfoxide (DMSO), N-methylpyrrolidone (NMP), γ-butyrolactone (GBL), dimethoxyethanol (2-ME), acetonitrile (ACN), 1,3-dimethyl-2-imidazolinone (DMI), and 1,3-dimethylpropaneurea (DMPU).

[0061] In some embodiments, perovskite materials can be represented as ABX3, where A is an organic / inorganic cation containing Cs. + 、Rb + MA + FA + etc., B is a metal cation containing Sn. 2+ and Pb 2+ X is a halide or pseudohalogen ion, containing I - ,Br - Cl - F - SCN - COO - Etc. That is, by way of example, in some specific embodiments, the precursor solution also includes lead halide salts, tin halide salts, and organic or inorganic amine salts. Specifically, the tin halide salt can be SnI2 or SnF2, the lead halide salt can be PbI2, and the organic amine salt can be methylamine iodide (MAI) or formamidinium hydroiodate (FAI).

[0062] In this invention, the structure of the perovskite solar cell is not specifically limited. It can be a conventional structure with a hole transport layer, or it can be a structure without a hole transport layer. Taking a structure without a hole transport layer as an example, the perovskite solar cell includes a conductive substrate, a perovskite active layer, an electron transport layer, and a metal electrode stacked sequentially.

[0063] In some embodiments, the perovskite solar cell can be prepared by the following method:

[0064] (1) Preparation of perovskite precursor solution. Dissolve the above additives and perovskite material in an organic solvent and stir until homogeneous to obtain a perovskite precursor solution.

[0065] (2) The above perovskite precursor solution is coated (specifically, it can be spin-coated, sprayed, or scraped) onto the substrate. After coating, the solvent is evaporated under vacuum to form a thin film. Then, it is annealed at 50°C-160°C for 1-30 minutes to form a perovskite active layer.

[0066] The substrate can be flexible or rigid, and it contains a transparent conductive metal electrode and a hole transport layer structure. Specifically, the transparent conductive metal electrode can be indium tin oxide (ITO) or fluorine-doped tin oxide (FTO), and the hole transport layer is poly(3,4-ethylenedioxythiophene):polystyrene sulfonic acid (PEDOT:PSS) or nickel oxide (NiO). x The following are examples of poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] (PTAA), SAMs such as [2-(9H-carbazole-9-yl)ethyl]phosphonic acid (2PACz), [4-(3,6-dimethyl-9H-carbazole-9-yl)butyl]phosphonic acid (Me-4PACz), [2-(3,6-dimethoxy-9H-carbazole-9-yl)ethyl]phosphonic acid (MeO-2PACz), poly(3-(4-carboxybutyl)thiophene-2,5,-dimethyl (P3CT) and its derivatives (P3CT-X), poly(3-ethylthiophene) (P3HT), etc.

[0067] (3) Preparation of electron transport layer: C is deposited on the surface of the thin film by vacuum evaporation. 60 Layer, then C 60 A (2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline) (BCP) layer is then deposited on top of the previous layer. The C layer mentioned above... 60 Layers can also use C 70 Layer replacement.

[0068] (4) Metal electrode evaporation: Depositing a metal electrode by vacuum evaporation. Specifically, the metal electrode can be one of Ag, Au, Cu or Al.

[0069] In other embodiments, the perovskite solar cell can also be prepared by the following methods:

[0070] A solution containing the above-mentioned additives is prepared, and a monolayer is formed on the substrate surface using this solution;

[0071] Then, a perovskite thin film is formed on the surface of a monolayer using a perovskite precursor solution containing perovskite material.

[0072] Specifically, the above-mentioned additives are added to an organic solvent (such as ethanol, isopropanol, methanol) to prepare a solution with a concentration of 0.2 mg / mL to 1 mg / mL. The solution is then spin-coated, scraped, or sprayed onto a conductive substrate and annealed at 100℃ to 120℃ for 5 min to 15 min to obtain the monolayer.

[0073] The present invention also provides a photovoltaic module, including the perovskite cell described above. For the same reason, this photovoltaic module has better photoelectric conversion efficiency.

[0074] In some implementations, the perovskite cells can be connected together by string welding, thereby collecting the electrical energy generated by the individual solar cells for subsequent transmission.

[0075] In some implementations, perovskite solar cells can be arranged at intervals or stacked together in a shingled manner.

[0076] For example, a photovoltaic module also includes an encapsulation layer and a cover plate, the encapsulation layer being used to cover the surface of the battery string and the cover plate being used to cover the surface of the encapsulation layer away from the battery string.

[0077] The present invention also provides a photovoltaic system comprising the aforementioned photovoltaic module. For the same reason, this photovoltaic system has a high photoelectric conversion efficiency.

[0078] Photovoltaic systems can be applied in photovoltaic power plants, such as ground-mounted, rooftop, and floating power plants, as well as in equipment or devices that utilize solar energy to generate electricity, such as user solar power supplies, solar streetlights, solar cars, and solar buildings. Of course, it's understandable that the application scenarios of photovoltaic systems are not limited to these; that is, photovoltaic systems can be applied in all fields that require solar energy to generate electricity. Taking a photovoltaic power generation network as an example, a photovoltaic system can include photovoltaic arrays, combiner boxes, and inverters. A photovoltaic array can be an array combination of multiple photovoltaic modules; for example, multiple photovoltaic modules can form multiple photovoltaic arrays. The photovoltaic arrays are connected to combiner boxes, which collect the current generated by the photovoltaic arrays. The collected current flows through an inverter, converts it into AC power required by the mains grid, and then connects to the mains grid to achieve solar power supply.

[0079] The technical solution of this application will be further explained below with reference to specific embodiments. Experimental methods in the following embodiments that do not specify specific conditions are generally performed under conventional conditions or as recommended by the manufacturer. Unless otherwise specified, all reagents used are commercially available or obtained through public channels.

[0080] The compounds represented by formulas (2) to (9) in this invention can be prepared by the following route:

[0081]

[0082] 4-Bromotriphenylamine (3.89 mmol), 4-carboxyphenylboronic acid (3.86 mmol), and tetrakis(triphenylphosphine)palladium Pd(PPh3)4 (0.12 mmol) were mixed with dimethyl glycol ether aqueous solution (50 mL) and 1 mol / L K2CO3 (27 mL) under anhydrous anaerobic conditions and stirred under nitrogen protection for 24 hours. After the reaction was completed, the mixture was poured into a mixed solvent of ethyl acetate and 2 mol / L hydrochloric acid (volume ratio 1:1). The organic layer was collected, washed twice with 2 mol / L hydrochloric acid, and dried with anhydrous magnesium sulfate. The solvent was removed by rotary evaporation. The crude product was purified by silica gel column chromatography (eluent THF, volume ratio 1:3) and dried to obtain the compound shown in formula (2). The NMR characterization results are as follows:

[0083] 1H NMR (400 MHz, CD2Cl2) δ 12.71 (s, 1H, OH), 8.07 (d, 2H, CH), 7.85 (d, 2H, CH), 7.55 (d, 2H, CH), 7.37 (d, 2H, CH), 7.24 (t, 4H, CH), 7.08 (d, 4H,CH), 7.00 (t, 2H,CH).

[0084]

[0085] N-(4-bromophenyl-)-N-phenylbenzidine (4.12 mmol), 4-carboxyphenylboronic acid (4.57 mmol), tetrakis(triphenylphosphine)palladium Pd(PPh3)4 (0.15 mmol), and potassium carbonate (27.55 mmol) were fully dissolved in 35 mL of an aqueous solution of 1,4-dioxane. The mixture was stirred and refluxed for 24 hours under nitrogen protection. After the reaction was completed, the organic layer was collected, purified by silica gel column chromatography, and dried to obtain the compound shown in formula (3). The NMR characterization results are as follows:

[0086] 1H NMR (400 MHz, CD2Cl2) δ 12.71 (s, 1H, OH), 8.07 (d, 2H, CH), 7.85 (d, 2H, CH), 7.75 (d, 2H, CH), 7.55 (d, 4H, CH), 7.49 (d, 2H, CH), 7.41 (m, 1H,CH), 7.37 (m, 4H, CH), 7.24 (t, 2H, CH), 7.08 (d, 2H, CH), 7.00 (t, 1H, CH).

[0087]

[0088] N,N-di(4-biphenyl)-N-(4-bromophenyl)amine (3.57 mmol), 4-carboxyphenylboronic acid (3.81 mmol), tetrakis(triphenylphosphine)palladium Pd(PPh3)4 (0.18 mmol), and potassium carbonate (31.24 mmol) were fully dissolved in 30 mL of an aqueous solution of 1,4-dioxane. The mixture was stirred and refluxed for 24 hours under nitrogen protection. After the reaction was completed, the organic layer was collected, purified by silica gel column chromatography, and dried to obtain the compound shown in formula (4). The NMR characterization results are as follows:

[0089] 1H NMR (400 MHz, CD2Cl2) δ 12.71 (s, 1H, OH), 8.07 (d, 2H, CH), 7.85 (d, 2H, CH), 7.75 (d, 4H, CH), 7.55 (d, 4H, CH), 7.49 (d, 4H, CH), 7.41 (s, 2H,CH), 7.37 (m, 6H, CH), 7.24 (m, 2H, CH).

[0090]

[0091] Weigh 2.48 mmol of 4,4-dibromotriphenylamine, 7.44 mmol of p-methoxycarbonylphenylboronic acid, 0.25 mmol of tetraphenylphosphine palladium, and 24.81 mmol of potassium carbonate and dissolve them completely in 25 mL of an aqueous solution of 1,4-dioxane. Reflux at 90 °C for 10 h under nitrogen protection. After cooling to room temperature, extract the reaction mixture with dichloromethane to obtain the crude product. After purification by silica gel column chromatography, dissolve the product completely in 25 mL of an aqueous solution of 1,4-dioxane, add 5.01 mL of saturated potassium carbonate aqueous solution, and reflux at 95 °C for 24 h. After cooling to room temperature, acidify with an aqueous solution of dilute hydrochloric acid. The solid precipitated by rotary evaporation is the compound shown in formula (5). Its NMR characterization results are as follows:

[0092] 1H NMR (400MHz, DMSO-d6) δ 12.88 (s, 2H), 8.00 (d, 4H), 7.78 (d, 4H), 7.71 (d, 4H), 7.42–7.35 (m, 2H), 7.18–7.11 (m, 7H).

[0093]

[0094] 4-Bromo-4',4''-dimethyltriphenylamine (3.75 mmol), 4-carboxyphenylboronic acid (3.88 mmol), tetrakis(triphenylphosphine)palladium Pd(PPh3)4 (0.18 mmol), and potassium carbonate (30.12 mmol) were thoroughly dissolved in 25 mL of tetrahydrofuran. The mixture was stirred and refluxed for 24 hours under nitrogen protection. After the reaction was completed, the organic layer was collected and purified by silica gel column chromatography to obtain the compound shown in formula (6). The NMR characterization results are as follows:

[0095] 1H NMR (400 MHz, CD2Cl2) δ 12.71 (s, 1H, OH), 8.07 (d, 2H, CH), 7.85 (d, 2H, CH), 7.55 (d, 2H, CH), 7.37 (d, 2H, CH), 7.15 (m, 4H, CH), 7.13 (m, 4H,CH), 2.32 (s, 6H,CH).

[0096]

[0097] 4-Bromo-4',4'-dimethoxytriphenylamine (3.26 mmol), 4-carboxyphenylboronic acid (3.38 mmol), tetrakis(triphenylphosphine)palladium Pd(PPh3)4 (0.18 mmol), and potassium carbonate (28.45 mmol) were thoroughly dissolved in 25 mL of tetrahydrofuran. The mixture was stirred and refluxed for 24 hours under nitrogen protection. After the reaction was completed, the organic layer was collected and purified by silica gel column chromatography to obtain the compound shown in formula (7). The NMR characterization results are as follows:

[0098] 1H NMR (400 MHz, CD2Cl2) δ 12.71 (s, 1H, OH), 8.07 (d, 2H, CH), 7.85 (d, 2H, CH), 7.55 (d, 2H, CH), 7.37 (d, 2H, CH), 7.18 (d, 4H, CH), 6.79 (d, 4H,CH), 3.81 (s, 6H,CH).

[0099]

[0100] 4-Bromotriphenylamine (3.89 mmol), 4-carboxy-2,6-dimethylphenylboronic acid (4.06 mmol), tetrakis(triphenylphosphine)palladium Pd(PPh3)4 (0.31 mmol), and potassium carbonate (30.82 mmol) were thoroughly dissolved in 30 mL of an aqueous solution of 1,4-dioxane. The mixture was stirred and refluxed for 24 hours under nitrogen protection. After the reaction was completed, the organic layer was collected and purified by silica gel column chromatography to obtain the compound shown in formula (8). The NMR characterization results are as follows:

[0101] 1H NMR (400 MHz, CD2Cl2) δ 12.74 (s, 1H, OH), 8.08 (s, 2H, CH), 7.55(d, 2H, CH), 7.37 (d, 2H, CH), 7.24 (t, 4H, CH), 7.08 (d, 2H, CH), 7.00 (m, 4H,CH), 2.57 (s, 6H,CH).

[0102]

[0103] 4-Bromotriphenylamine (3.89 mmol), 2,6-difluoro-4-carboxyphenylboronic acid (4.22 mmol), tetrakis(triphenylphosphine)palladium Pd(PPh3)4 (0.15 mmol), and potassium carbonate (30.11 mmol) were thoroughly dissolved in 25 mL of tetrahydrofuran. The mixture was stirred and refluxed for 24 hours under nitrogen protection. After the reaction was completed, the organic layer was collected and dried to obtain the compound shown in formula (9). The NMR characterization results are as follows:

[0104] 1H NMR (400 MHz, CD2Cl2) δ 12.74 (s, 1H, OH), 7.75 (d, 2H, CH), 7.55(d, 2H, CH), 7.37 (d, 2H, CH), 7.24 (t, 4H, CH), 7.08 (d, 4H, CH), 7.00 (t, 2H,CH).

[0105] Example 1

[0106] This embodiment provides a perovskite battery, including a substrate, a perovskite active layer, an electron transport layer and an electrode, wherein the perovskite active layer includes an additive, which is the compound 4'-(diphenylamino)-[1,1'-biphenyl]-4-carboxylic acid shown in formula (2).

[0107] This perovskite solar cell was prepared by the following method:

[0108] For large areas (36cm) 2 The FTO conductive glass substrate is scribed with P1 laser to form independent electrode areas. Then, the organic and inorganic stains on the substrate surface are cleaned with detergent, followed by ultrasonic cleaning with deionized water and ethanol for 40 minutes in sequence, and then dried with nitrogen. The cleaned FTO conductive glass is then treated with oxygen plasma for 8 minutes.

[0109] Preparation of perovskite precursor solution: Perovskite material (specifically: organic halide FAI, metal halide CsI, inorganic halide PbI2, molar ratio of 0.8:0.2:1) and additives were dissolved in a mixed solvent of dimethylformamide (DMF) and N-methylpyrrolidone (NMP) (DMF:NMP volume ratio of 6:1), wherein the total concentration of perovskite material was 1.2 mmol / mL and the concentration of additives was 1.2 mg / mL.

[0110] Take 80 μL of the above perovskite precursor solution and coat it onto the surface of the treated substrate. After coating, under a vacuum of 3 Pa, control the temperature at 25 °C to allow the solvent to evaporate and form a thin film. Then, anneal at 60 °C for 5 min and then anneal at 150 °C for 15 min to complete crystallization.

[0111] Subsequently, C60 and BCP layers were deposited sequentially via vacuum evaporation, followed by P2 laser scribing to separate the functional layers. Silver electrodes were then deposited, and P3 laser scribing was used to establish conductivity in the electrode regions, resulting in a perovskite solar cell.

[0112] Example 2

[0113] This embodiment provides a perovskite battery, which differs from Example 1 in that an equal mass of compound 4',4'''-(phenylazinediyl)bis(([1,1'-biphenyl]-4-carboxylic acid)) of formula (5) is used to replace the additive in Example 1.

[0114] Example 3

[0115] This embodiment provides a perovskite battery, which differs from Example 1 in that an equal mass of compound 4'-(diphenylamino)-2,6-difluoro-[1,1'-biphenyl]-4-carboxylic acid of formula (9) is used to replace the additive in Example 1.

[0116] Example 4

[0117] This embodiment provides a perovskite battery, which differs from Example 1 in that an equal mass of compound 4'-(diphenylamino)-2,6-dimethyl-[1,1'-biphenyl]-4-carboxylic acid of formula (8) is used to replace the additive in Example 1.

[0118] Example 5

[0119] This embodiment provides a perovskite battery, which differs from Example 1 in that an equal mass of compound 4'-(di-p-benzoylamino)-[1,1'-biphenyl]-4-carboxylic acid of formula (6) is used to replace the additive in Example 1.

[0120] Example 6

[0121] This embodiment provides a perovskite battery, which differs from Example 1 in that an equal mass of compound 4'-(bis(p-4-methoxyphenyl)amino)-[1,1'-biphenyl]-4-carboxylic acid of formula (7) is used to replace the additive in Example 1.

[0122] Example 7

[0123] This embodiment provides a perovskite battery, which differs from Embodiment 1 in that the concentration of the additive in the perovskite precursor solution is 0.05 mg / mL.

[0124] Example 8

[0125] This embodiment provides a perovskite battery, which differs from Embodiment 1 in that the concentration of the additive in the perovskite precursor solution is 1.5 mg / mL.

[0126] Example 9

[0127] This embodiment provides a perovskite battery, which differs from Embodiment 1 in that the concentration of the additive in the perovskite precursor solution is 3 mg / mL.

[0128] Example 10

[0129] This embodiment provides a perovskite precursor solution, which differs from Example 1 in that the concentration of the additive is 3.5 mg / mL.

[0130] Example 11

[0131] This embodiment provides a perovskite solar cell, which differs from Embodiment 1 in that it is prepared using the following method:

[0132] For large areas (36cm) 2 The FTO conductive glass substrate is scribed with P1 laser to form independent electrode areas. Then, the organic and inorganic stains on the substrate surface are cleaned with detergent, followed by ultrasonic cleaning with deionized water and ethanol for 40 minutes in sequence, and then dried with nitrogen. The cleaned FTO conductive glass is then treated with oxygen plasma for 8 minutes.

[0133] Monolayer preparation: 4'-(diphenylamino)-[1,1'-biphenyl]-4-carboxylic acid (additive in Example 1) was dissolved in the organic solvent ethanol to prepare a solution with a concentration of 0.5 mg / mL. 80 μL of this solution was scraped onto the surface of the substrate after the above treatment. After the scraping was completed, the substrate was annealed at 110 °C for 10 min.

[0134] Preparation of perovskite precursor solution: Perovskite material (specifically: organic halide FAI, metal halide CsI, inorganic halide PbI2, molar ratio of 0.8:0.2:1) was dissolved in a mixed solvent of dimethylformamide (DMF) and N-methylpyrrolidone (NMP) (DMF:NMP volume ratio of 6:1), wherein the total concentration of perovskite material was 1.5 mmol / mL.

[0135] Take 80 μL of the above perovskite precursor solution and coat it onto a monolayer. After coating, under a vacuum of 3 Pa, control the temperature at 25 °C to allow the solvent to evaporate and form a thin film. Then, anneal at 60 °C for 5 min and then anneal at 150 °C for 15 min to complete crystallization.

[0136] Subsequently, C60 and BCP layers were deposited sequentially via vacuum evaporation, followed by P2 laser scribing to separate the functional layers. Silver electrodes were then deposited, and P3 laser scribing was used to establish conductivity in the electrode regions, resulting in a perovskite solar cell.

[0137] Comparative Example 1

[0138] This comparative example provides a perovskite battery, which differs from Example 1 in that the perovskite precursor solution does not contain additives.

[0139] Comparative Example 2

[0140] This comparative example provides a perovskite battery, which differs from Example 1 in that an equal mass of [4-(3,6-dimethyl-9H-carbazole-9-yl)butyl]phosphate (i.e., Me-4PACz) is used to replace 4'-(diphenylamino)-[1,1'-biphenyl]-4-carboxylic acid (the additive in Example 1).

[0141] Experimental Example 1

[0142] The contact angle of the perovskite precursor solutions in Examples 1-10 and Comparative Examples 1-2 was tested.

[0143] Specifically, the FTO substrate was ultrasonically cleaned for 15 minutes each in ultrapure water and ethanol containing cleaning agent to thoroughly remove organic and inorganic residues from the surface. Then, the perovskite precursor solution (2 μL) to be tested was dropped onto the FTO substrate, and the change in its static contact angle was recorded. The results are as follows: Figure 1 As shown in Table 1 below. Figure 1 The figures show the contact angle test results of Examples 1-6 and Comparative Examples 1-2.

[0144] Table 1

[0145]

[0146] The results above show that the contact angles of the perovskite precursor solutions in Examples 1-10 are all smaller than those in Comparative Examples 1 and 2, indicating that the perovskite precursor solutions provided by the present invention have better wettability on low-polarity inorganic substrates.

[0147] Experimental Example 2

[0148] (1) Observe the films formed by the perovskite precursor solutions in Examples 1-3 and Comparative Example 2. The results are as follows: Figure 2 As shown.

[0149] Depend on Figure 2 It can be seen that the perovskite precursor solutions in Examples 1-3 can be applied over a large area (36 cm²). 2 The perovskite precursor solution in Example 1 was uniformly spread on the substrate, resulting in a smooth, continuous perovskite film without obvious pinholes. In contrast, the perovskite precursor solution in Comparative Example 1 could hardly spread on the substrate, forming significant shrinkage and exposed areas, making it difficult to form a continuous, dense film. Comparative Example 2, using the industry-standard Me-4PACz as an additive, also exhibited significant uneven coating and film defects. Therefore, the perovskite precursor solutions in Examples 1-3 have better wettability on low-polarity substrates and superior spreading and film-forming capabilities during spin coating, meaning the perovskite films in Examples 1-3 are of higher quality.

[0150] (2) The photoelectric conversion efficiency of the perovskite cells in Examples 1-11 and Comparative Examples 1-2 was tested.

[0151] All perovskite solar cells were compared and analyzed under the same preparation and testing conditions. Their photoelectric performance was within the standard AM1.5G (100 mW·cm⁻¹) range. -2 Tests were conducted under simulated sunlight conditions, and the evaluation parameters included short-circuit current density (Jsc), open-circuit voltage (Voc), fill factor (FF), and power conversion efficiency (PCE). The results are as follows: Figure 3 , 4 As shown in Table 2 below. Figure 3 The test results are for the perovskite battery modules prepared from the perovskite precursor solutions in Examples 1-6 and Comparative Example 2. Figure 4 The test results are for the perovskite battery modules prepared in Examples 7-10 (different mass percentages of additives in the perovskite precursor solution). Figure 5The results are the test results of the perovskite battery modules prepared from the perovskite precursor solutions in Example 11 and Comparative Example 2.

[0152] Table 2

[0153]

[0154] The results above show that the perovskite solar cells in Examples 1-11 have better photoelectric conversion efficiency than those in Comparative Examples 1 and 2, indicating that introducing the additives of the present invention into the perovskite active layer of the perovskite solar cell is beneficial to improving the photoelectric conversion efficiency of the cell.

[0155] As can be seen from the comparison of Examples 1 and 7-10, when the mass of the additive in the perovskite solar cell is 0.06‰-3.84‰ of the mass of the perovskite material, the photoelectric conversion efficiency of the perovskite solar cell is better.

[0156] As can be seen from the comparison between Example 11 and Comparative Example 2, when the additive is introduced into the perovskite solar cell as a separate monolayer, it can still improve the photoelectric conversion efficiency of the perovskite solar cell.

[0157] Finally, it should be noted that other embodiments of the invention will readily occur to those skilled in the art upon consideration of the specification and practice of the invention disclosed herein. This invention is intended to cover any variations, uses, or adaptations of the invention that follow the general principles of the invention and include common knowledge or customary techniques in the art not disclosed herein, and is not limited to what has been described above. Various modifications and changes can be made without departing from its scope. The scope of the invention is limited only by the appended claims.

Claims

1. A perovskite solar cell, characterized in that, It includes a perovskite active layer, wherein the perovskite active layer includes an additive, the additive being a twisted conjugated molecule, and the molecular structure containing at least one conjugated group and at least one carboxyl group.

2. The perovskite solar cell according to claim 1, characterized in that, The conjugated group includes at least one selected from phenyl, triphenylamino, biphenyl, naphthyl, or anthracene; and / or The carboxyl group is connected to the conjugated group by a single bond or a carbon chain, and the carbon chain has 1-4 carbon atoms.

3. The perovskite solar cell according to claim 1, characterized in that, The conjugated groups include phenyl and triphenylamine, wherein the carbon atom of the benzene ring opposite to the nitrogen atom in the triphenylamine group is replaced by a phenyl group; and the carbon atom of the phenyl group opposite to the carbon atom is replaced by a carboxyl group. Preferably, the general molecular structure of the additive is shown in formula (1) below: Equation (1); R1, R2, R3, and R4 are each independently selected from at least one of H, a halogen atom, a C1-C20 alkyl group, a C6-C30 aryl group, and a C6-C30 heteroaryl group.

4. The perovskite solar cell according to claim 3, characterized in that, The additive is selected from at least one of the following: 。 5. The perovskite solar cell according to any one of claims 1-4, characterized in that, The perovskite active layer includes perovskite material, and the mass of the additive is 0.06‰-3.84‰ of the mass of the perovskite material.

6. The perovskite solar cell according to any one of claims 1-5, characterized in that, The perovskite active layer comprises a perovskite film and a monolayer, wherein the monolayer is located between the perovskite film and the substrate, and the monolayer comprises the additives described in any one of claims 1-5.

7. A method for preparing a perovskite solar cell, characterized in that, include: Prepare a perovskite precursor solution comprising perovskite material and the additives described in any one of claims 1-6; The perovskite active layer was prepared on the substrate surface using a perovskite precursor solution to obtain the perovskite solar cell.

8. The method for preparing a perovskite solar cell according to claim 7, characterized in that, In the perovskite precursor solution, the concentration of the additive is 0.05 mg / mL-3 mg / mL, and the total concentration of the perovskite material is 0.8 mol / L-1.5 mol / L; and / or The perovskite materials include lead halide salts, tin halide salts, and amine salts.

9. A photovoltaic module, characterized in that, Including the perovskite solar cell as described in claim 8.

10. A photovoltaic system, characterized in that, This includes the perovskite cell as described in claim 8 or the photovoltaic module as described in claim 9.

Images