Perovskite cell, hole transport layer precursor solution, hole transport layer, preparation method and application thereof

Abstract

The application provides a hole transport layer precursor solution, a hole transport layer and a preparation method and application thereof, and a perovskite battery, and belongs to the technical field of hole transport layers.The hole transport layer precursor solution comprises self-assembled monomers and an organic solvent;the organic solvent comprises solvent A, solvent B and solvent C;the solvent A comprises one or more of phosphoric acid ester solvents and alcohol ether solvents;the solvent A contains four hydrogen bond acceptors;the boiling point of the solvent A is 215 DEG C-290 DEG C;the solvent B comprises one or more of ethanol, isopropanol, n-propanol, butanol, ethylene glycol and N, N-dimethylformamide; and the solvent C comprises one or more of ethyl acetate and n-hexane.Through the ternary hydrogen bond network formed by the solvent A, the solvent B and the solvent C, the agglomeration degree of the SAM molecules is significantly reduced, and the device performance is improved.

Description

Technical Field

[0001] This application relates to the field of hole transport layer technology, and in particular to hole transport layer precursor solutions, hole transport layers and their preparation methods and applications, and perovskite solar cells. Background Technology

[0002] The SAM layer (self-assembled monolayer) is a key interface layer in perovskite solar cells. Its disordered molecular arrangement can lead to problems such as interface defects, charge recombination, and decreased device stability. Traditional SAM deposition methods (such as dip coating and spin coating) are easily affected by substrate roughness, molecular aggregation, and solvent residue, making it difficult to achieve uniform coverage and ordered arrangement of the monolayer.

[0003] The solvent used in the hole transport layer precursor solution has a significant impact on the performance of the hole transport layer. Currently, the solvents used in hole transport layer precursors have defects such as high volatility, high polarity, or competitive adsorption effects with SAM molecules. These defects result in a limited self-assembly time for SAM molecules in solution, increasing the risk of SAM molecule aggregation, reducing the compactness of the hole transport layer, and seriously affecting the stability and uniformity of the hole transport layer. Summary of the Invention

[0004] Based on this, the main objective of this application is to provide a hole transport layer precursor solution, a hole transport layer and its preparation method and application, and a perovskite solar cell, so as to reduce the aggregation of SAM molecules and thereby improve the uniformity and stability of the hole transport layer.

[0005] In a first aspect, this application provides a hole transport layer precursor solution comprising a self-assembled monomolecule and an organic solvent;

[0006] The organic solvents include solvent A, solvent B, and solvent C;

[0007] Solvent A includes one or more of phosphate ester solvents and alcohol ether solvents;

[0008] Solvent A contains 4 hydrogen bond acceptors;

[0009] The boiling point of solvent A is 215℃-290℃;

[0010] Solvent B includes one or more of ethanol, isopropanol, n-propanol, butanol, ethylene glycol, and N,N-dimethylformamide;

[0011] The solvent C includes one or more of ethyl acetate and n-hexane.

[0012] In some embodiments, solvent A includes one or more of triethylene glycol and triethyl phosphate.

[0013] In some embodiments, the volume ratio of solvent A, solvent B and solvent C is (10-30):(30-80):(10-40).

[0014] In some embodiments, the mass-to-volume ratio of the self-assembled monomolecule to the solvent is (0.01 mg to 10 mg): 1 mL.

[0015] In some embodiments, the self-assembled monomolecule includes one or more of phosphate self-assembled monomolecules, silane self-assembled monomolecules, and thiol self-assembled monomolecules;

[0016] The self-assembled phosphoric acid monomers include [4-(3,6-dimethoxy-9H-carbazole-9-yl)butyl]phosphoric acid, [2-(3,6-dimethoxy-9H-carbazole-9-yl)ethyl]phosphoric acid, [3-(3,6-dimethoxy-9H-carbazole-9-yl)propyl]phosphoric acid, [6-(3,6-dimethoxy-9H-carbazole-9-yl)hexyl]phosphoric acid, [2-(3,6-dimethyl-9H-carbazole-9-yl)ethyl]phosphoric acid, [3-(3,6-dimethyl-9H-carbazole-9-yl)propyl]phosphoric acid, [6-(3,6-dimethyl-9H-carbazole-9-yl)hexyl]phosphoric acid, [1-(3,6-dimethyl-9H-carbazole-9-yl)methyl]phosphoric acid, [4-( [3,6-Dimethyl-9H-carbazole-9-yl)butyl]phosphate, [8-(3,6-dimethyl-9H-carbazole-9-yl)octyl]phosphate, [1-(9H-carbazole-9-yl)methyl]phosphate, (2-(9H-carbazole-9-yl)ethyl)phosphate, [3-(9H-carbazole-9-yl)propyl]phosphate, [4-(9H-carbazole-9-yl)butyl]phosphate, [6-(9H-carbazole-9-yl)hexyl]phosphate, [8-(9H-carbazole-9-yl)octyl]phosphate, [4-(N,N-di(4-methoxyphenylamino)phenyl)propyl]phosphate, 2,3,4,5,6-pentafluorobenzyl phosphate, [2-(9H-9,-phenyl-3,3,-di-carbazole-9-yl)ethyl]phosphate [4-(9H-9,-phenyl-3,3,-di-carbazole-9-yl)butyl]phosphoric acid, [(4-(diphenylamino)phenyl)ethyl]phosphoric acid, [(4-(diphenylamino)phenyl)propyl]phosphoric acid, [4-(10H-phenthiazin-10-yl)butyl]phosphoric acid, [2-(7H-dibenzocarbazole-7-yl)ethyl]phosphoric acid, [4-(7H-dibenzocarbazole-7-yl)butyl]phosphoric acid, [3-(3,6-dibromo-9H-carbazole-9-yl)propyl]phosphoric acid, [4-(3,6-dibromo-9H-carbazole-9-yl)butyl]phosphoric acid, [6-(3,6-dibromo-9H-carbazole-9-yl)hexyl]phosphoric acid, [1-(3,6-di-tert-butyl-9H-carbazole]phosphoric acid, [4-(9H-9,-phenyl-3,3,-di-carbazole-9-yl)butyl]phosphoric acid, [4-(9H-9,-phenyl-3, ...tert-butyl-9H-carbazole]phosphoric acid, [4 [-9-yl)methyl]phosphoric acid, [2-(3,6-di-tert-butyl-9H-carbazole-9-yl)ethyl]phosphoric acid, [3-(3,6-di-tert-butyl-9H-carbazole-9-yl)propyl]phosphoric acid, [4-(3,6-di-tert-butyl-9H-carbazole-9-yl)butyl]phosphoric acid, [6-(3,6-di-tert-butyl-9H-carbazole-9-yl)hexyl]phosphoric acid, [8-(3,6-di-tert-butyl-9H-carbazole-9-yl)octyl]phosphoric acid, [1-(3,6-diphenyl-9H-carbazole-9-yl)methyl]phosphoric acid, [2-(3,6-diphenyl-9H-carbazole-9-yl)ethyl]phosphoric acid, [3-(3,6-diphenyl ...phenyl-9H-carbazole-9-yl)propyl]phosphoric acid, [4-(3,6-diphenyl-9H-carbazole-9-yl)ethylOne or more of the following: [6-(3,6-diphenyl-9H-carbazole-9-yl)butyl]phosphate, [8-(3,6-diphenyl-9H-carbazole-9-yl)hexyl]phosphate, [2-(10H-phenoxazine-10-yl)ethyl]phosphate, [4-(3,7-dibromo-10H-phenthiazine-10-yl)butyl]phosphate, and [4-(3,7-dibromo-10H-phenoxazine-10-yl)butyl]phosphate;

[0017] The silane self-assembled monomolecules include one or more of 3-aminopropyltriethoxysilane, 3-epoxypropoxypropyltrimethoxysilane, γ-aminopropyltriethoxysilane, 3-mercaptopropyltriethoxysilane, and tridecafluorooctyltriethoxysilane.

[0018] The thiol self-assembled monomers include one or more of undecylthiol, 10-mercapto-1-decaol, 6-mercapto-hexanoic acid, 11-mercaptoundecanoic acid, and 16-mercaptohexadecanoic acid.

[0019] The second aspect of this application provides a method for preparing a hole transport layer, comprising the following steps:

[0020] The hole transport layer precursor solution described in the first aspect is deposited and annealed to prepare the hole transport layer.

[0021] In some embodiments, the deposition methods include: blade coating, spin coating, slot coating, inkjet printing, or screen printing.

[0022] In some implementations, the annealing conditions include a temperature of 50°C-120°C and a time of 1 min-20 min.

[0023] In a third aspect of this application, a hole transport layer is provided, which is prepared by the method for preparing a hole transport layer described in the second aspect.

[0024] In some embodiments, the thickness of the hole transport layer is 1 nm to 10 nm.

[0025] In a fourth aspect of this application, an application of a hole transport layer in a perovskite solar cell is provided, wherein the hole transport layer is a hole transport layer prepared by the method described in the second aspect or a hole transport layer described in the third aspect.

[0026] In a fifth aspect of this application, a perovskite solar cell is provided, comprising a conductive substrate, a hole transport layer, a perovskite layer, an electron transport layer, a buffer layer, and an electrode layer stacked sequentially.

[0027] The hole transport layer is either the hole transport layer prepared by the method described in the second aspect or the hole transport layer described in the third aspect.

[0028] Compared with traditional technologies, this application has at least the following beneficial effects:

[0029] This application employs an organic solvent comprising solvents A, B, and C to form a ternary hydrogen bond network in the hole transport layer precursor solution. This significantly reduces the aggregation degree of self-assembled single molecules (SAM molecules), thereby improving the uniformity and stability of the hole transport layer and enhancing the device performance of perovskite solar cells. Solvent A comprises one or more phosphate ester solvents and alcohol ether solvents, contains four hydrogen bond acceptors, and has a boiling point of 215℃-290℃. It can bind to the terminal groups of the self-assembled single molecules (SAM molecules) to form multiple hydrogen bond networks, improving the dispersion uniformity and stability of SAM molecules in the hole transport layer precursor solution. Solvent B has a strong solubility for SAM molecules. Solvent C has a low boiling point and can preferentially vaporize during the preparation of the hole transport layer, forming a volatilization gradient and regulating the arrangement of SAM molecules. The hole transport layer prepared using this hole transport layer precursor solution exhibits excellent uniformity and stability, thus improving the device performance of perovskite solar cells. Detailed Implementation

[0030] The present application will be further described in detail below with reference to the embodiments and examples. These embodiments and examples are only for illustrating the present application and are not intended to limit the scope of the present application. The purpose of providing these embodiments and examples is to make the disclosure of the present application more thorough and comprehensive. It should also be understood that the present application can be implemented in many different forms and is not limited to the embodiments and examples described herein. Those skilled in the art can make various modifications or alterations without departing from the spirit of the present application, and the equivalent forms obtained also fall within the protection scope of the present application. In addition, numerous specific details are set forth in the following description to provide a fuller understanding of the present application. It should be understood that the present application can be implemented without one or more of these details.

[0031] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0032] In this application, the hydrogen bond acceptor is an atom that can form a hydrogen bond with a hydrogen atom in the hydrogen bond donor.

[0033] To address the shortcomings of current solvents used in hole transport layer precursors, such as high volatility, high polarity, or competitive adsorption with SAM molecules, this application employs an organic solvent comprising solvent A, solvent B, and solvent C to form a ternary hydrogen bond network in the hole transport layer precursor solution. This significantly reduces the aggregation degree of SAM molecules, improves the uniformity and stability of the hole transport layer, and enhances the device performance of perovskite solar cells. Solvent A comprises one or more phosphate ester solvents and alcohol ether solvents, contains four hydrogen bond acceptors, and has a boiling point of 215℃-290℃. It can bind to the terminal groups of SAM molecules to form multiple hydrogen bond networks, improving the dispersion uniformity of SAM molecules in the hole transport layer precursor solution. Solvent B has a strong solubility for SAM molecules. Solvent C has a low boiling point and can preferentially vaporize during the preparation of the hole transport layer, forming a volatilization gradient and regulating the arrangement of SAM molecules.

[0034] In a first aspect, this application provides a hole transport layer precursor solution comprising a self-assembled monomolecule and an organic solvent;

[0035] The organic solvents include solvent A, solvent B, and solvent C;

[0036] Solvent A includes one or more of phosphate ester solvents and alcohol ether solvents;

[0037] Solvent A contains 4 hydrogen bond acceptors;

[0038] The boiling point of solvent A is 215℃-290℃;

[0039] Solvent B includes one or more of methanol, ethanol, isopropanol, n-propanol, butanol, ethylene glycol, and N,N-dimethylformamide;

[0040] The solvent C includes one or more of ethyl acetate and n-hexane.

[0041] This application utilizes an organic solvent comprising solvent A, solvent B, and solvent C to form a ternary hydrogen bond network in the hole transport layer precursor solution, which can significantly reduce the aggregation degree of SAM molecules. The hole transport layer prepared using the hole transport layer precursor solution exhibits excellent uniformity and stability, significantly improving the device performance of perovskite solar cells.

[0042] In some embodiments, solvent A contains four hydrogen bond acceptors, which include one or more of the following: an oxygen atom in an ether bond, an oxygen atom in a hydroxyl group, and an oxygen atom in a phosphate ester group.

[0043] In some embodiments, solvent A comprises one or more of phosphate ester solvents and alcohol ether solvents; the phosphate ester solvent includes triethyl phosphate; and the alcohol ether solvent includes triethylene glycol. Solvent A, comprising one or more of phosphate ester solvents and alcohol ether solvents, contains four hydrogen bond acceptors and has a boiling point of 215°C-290°C. Solvent A can bind to the terminal groups of SAM molecules to form multiple hydrogen bond networks, promoting the orderly arrangement of SAM molecules. When used in combination with solvents B and C, it can significantly improve the uniformity of SAM molecule arrangement in the hole transport layer precursor solution, improve the uniformity and stability of the hole transport layer, and enhance the performance of perovskite solar cells.

[0044] In some embodiments, solvent A includes one or more of triethylene glycol and triethyl phosphate.

[0045] Solvent B includes one or more of ethanol, isopropanol, n-propanol, butanol, ethylene glycol, and N,N-dimethylformamide. Solvent B has a strong dissolving ability for SAM molecules, which can improve the dispersibility of SAM molecules, reduce the formation of SAM molecule aggregates, and when used in combination with solvents A and C, can significantly improve the uniformity of SAM molecule arrangement in the hole transport layer precursor solution, improve the uniformity and stability of the hole transport layer, and enhance the performance of perovskite solar cells.

[0046] In some embodiments, solvent C includes one or more of ethyl acetate and n-hexane. Solvent C has a low boiling point and can preferentially vaporize to form a volatilization gradient during the preparation of the hole transport layer, thereby regulating the self-assembly kinetics and orderliness of SAM molecules. When used in combination with solvents A and B, it can significantly improve the uniformity and stability of the hole transport layer, thus enhancing the performance of the perovskite solar cell.

[0047] In some embodiments, the volume ratio of solvent A, solvent B and solvent C is (10-30):(30-80):(10-40), which can be 10:30:40, 10:60:30, 30:60:10, 30:30:40 or 10:80:10.

[0048] In some embodiments, the mass-to-volume ratio of the self-assembled monomer to the organic solvent is (0.01 mg: 10 mg): 1 mL, which can be 0.01 mg: 1 mL, 0.05 mg: 1 mL, 0.1 mg: 1 mL, 0.5 mg: 1 mL, 1 mg: 1 mL, 2 mg: 1 mL, 5 mg: 1 mL, 8 mg: 1 mL, or 10 mg: 1 mL.

[0049] In some embodiments, the self-assembled monomolecule includes one or more of phosphate self-assembled monomolecules, silane self-assembled monomolecules, and thiol self-assembled monomolecules;

[0050] The self-assembled phosphoric acid monomers include [4-(3,6-dimethoxy-9H-carbazole-9-yl)butyl]phosphoric acid, [2-(3,6-dimethoxy-9H-carbazole-9-yl)ethyl]phosphoric acid, [3-(3,6-dimethoxy-9H-carbazole-9-yl)propyl]phosphoric acid, [6-(3,6-dimethoxy-9H-carbazole-9-yl)hexyl]phosphoric acid, [2-(3,6-dimethyl-9H-carbazole-9-yl)ethyl]phosphoric acid, [3-(3,6-dimethyl-9H-carbazole-9-yl)propyl]phosphoric acid, [6-(3,6-dimethyl-9H-carbazole-9-yl)hexyl]phosphoric acid, [1-(3,6-dimethyl-9H-carbazole-9-yl)methyl]phosphoric acid, [4-( [3,6-Dimethyl-9H-carbazole-9-yl)butyl]phosphate, [8-(3,6-dimethyl-9H-carbazole-9-yl)octyl]phosphate, [1-(9H-carbazole-9-yl)methyl]phosphate, (2-(9H-carbazole-9-yl)ethyl)phosphate, [3-(9H-carbazole-9-yl)propyl]phosphate, [4-(9H-carbazole-9-yl)butyl]phosphate, [6-(9H-carbazole-9-yl)hexyl]phosphate, [8-(9H-carbazole-9-yl)octyl]phosphate, [4-(N,N-di(4-methoxyphenylamino)phenyl)propyl]phosphate, 2,3,4,5,6-pentafluorobenzyl phosphate, [2-(9H-9,-phenyl-3,3,-di-carbazole-9-yl)ethyl]phosphate [4-(9H-9,-phenyl-3,3,-di-carbazole-9-yl)butyl]phosphoric acid, [(4-(diphenylamino)phenyl)ethyl]phosphoric acid, [(4-(diphenylamino)phenyl)propyl]phosphoric acid, [4-(10H-phenthiazin-10-yl)butyl]phosphoric acid, [2-(7H-dibenzocarbazole-7-yl)ethyl]phosphoric acid, [4-(7H-dibenzocarbazole-7-yl)butyl]phosphoric acid, [3-(3,6-dibromo-9H-carbazole-9-yl)propyl]phosphoric acid, [4-(3,6-dibromo-9H-carbazole-9-yl)butyl]phosphoric acid, [6-(3,6-dibromo-9H-carbazole-9-yl)hexyl]phosphoric acid, [1-(3,6-di-tert-butyl-9H-carbazole]phosphoric acid, [4-(9H-9,-phenyl-3,3,-di-carbazole-9-yl)butyl]phosphoric acid, [4-(9H-9,-phenyl-3, ...tert-butyl-9H-carbazole]phosphoric acid, [4 [-9-yl)methyl]phosphoric acid, [2-(3,6-di-tert-butyl-9H-carbazole-9-yl)ethyl]phosphoric acid, [3-(3,6-di-tert-butyl-9H-carbazole-9-yl)propyl]phosphoric acid, [4-(3,6-di-tert-butyl-9H-carbazole-9-yl)butyl]phosphoric acid, [6-(3,6-di-tert-butyl-9H-carbazole-9-yl)hexyl]phosphoric acid, [8-(3,6-di-tert-butyl-9H-carbazole-9-yl)octyl]phosphoric acid, [1-(3,6-diphenyl-9H-carbazole-9-yl)methyl]phosphoric acid, [2-(3,6-diphenyl-9H-carbazole-9-yl)ethyl]phosphoric acid, [3-(3,6-diphenyl ...phenyl-9H-carbazole-9-yl)propyl]phosphoric acid, [4-(3,6-diphenyl-9H-carbazole-9-yl)ethylOne or more of the following: [6-(3,6-diphenyl-9H-carbazole-9-yl)butyl]phosphate, [8-(3,6-diphenyl-9H-carbazole-9-yl)hexyl]phosphate, [2-(10H-phenoxazine-10-yl)ethyl]phosphate, [4-(3,7-dibromo-10H-phenthiazine-10-yl)butyl]phosphate, and [4-(3,7-dibromo-10H-phenoxazine-10-yl)butyl]phosphate;

[0051] The silane self-assembled monomolecules include one or more of 3-aminopropyltriethoxysilane (APTES), 3-epoxypropoxypropyltrimethoxysilane (KH-560), γ-aminopropyltriethoxysilane (KH-550), 3-mercaptopropyltriethoxysilane (K-MEPTS), and tridecafluorooctyltriethoxysilane;

[0052] The thiol self-assembled monomers include one or more of undecylthiol, 10-mercapto-1-decaol, 6-mercapto-hexanoic acid, 11-mercaptoundecanoic acid, and 16-mercaptohexadecanoic acid.

[0053] The second aspect of this application provides a method for preparing a hole transport layer, comprising the following steps:

[0054] The hole transport layer precursor solution described in the first aspect is deposited and annealed to prepare the hole transport layer.

[0055] In some embodiments, the deposition methods include blade coating, spin coating, slot coating, inkjet printing, or screen printing. The hole transport layer precursor solution described in this application can be deposited using various large-area deposition methods, and the preparation process is simple.

[0056] In some embodiments, the conditions for inkjet printing include: inkjet voltage of 12V, Y-axis movement speed of 800mm / s, printing resolution of 720×720, print nozzle droplet volume of 5pL, and jetting frequency of 12000Hz.

[0057] In some embodiments, the annealing conditions include: a temperature of 50°C-120°C, which can be 50°C, 55°C, 60°C, 65°C, 70°C, 80°C, 90°C, 100°C, 110°C or 120°C, and a time of 1 min-20 min, which can be 1 min, 2 min, 3 min, 4 min, 5 min, 10 min or 20 min.

[0058] In a third aspect of this application, a hole transport layer is provided, which is prepared by the method for preparing a hole transport layer described in the second aspect.

[0059] In some embodiments, the thickness of the hole transport layer is 1nm-10nm, and can be 1nm, 2nm, 3nm, 4nm, 5nm, 6nm, 7nm, 8nm, 9nm or 10nm.

[0060] In a fourth aspect of this application, an application of a hole transport layer in a perovskite solar cell is provided, wherein the hole transport layer is a hole transport layer prepared by the method described in the second aspect or a hole transport layer described in the third aspect.

[0061] In a fifth aspect of this application, a perovskite solar cell is provided, comprising a conductive substrate, a hole transport layer, a perovskite layer, an electron transport layer, a buffer layer, and an electrode layer stacked sequentially.

[0062] The hole transport layer is either the hole transport layer prepared by the method described in the second aspect or the hole transport layer described in the third aspect.

[0063] The embodiments of this application will be described in detail below with reference to examples. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of this application. For experimental methods in the following embodiments where specific conditions are not specified, please refer to the guidelines given in this application, or follow experimental manuals or conventional conditions in the art, or follow the conditions recommended by the manufacturer, or refer to experimental methods known in the art.

[0064] Example 1

[0065] The fabrication method of perovskite solar cells is as follows:

[0066] (1) Substrate pretreatment: 100×100mm FTO glass (fluorine-doped tin dioxide conductive glass) was scribed with P1 laser, and then ultrasonically cleaned with deionized water, anhydrous ethanol, acetone and isopropanol for 10 min respectively. After UV-Ozone cleaning for 25 min, the surface contact angle was reduced to <10° to obtain pretreated FTO conductive glass.

[0067] (2) Preparation of hole transport layer precursor solution: [4-(3,6-dimethoxy-9H-carbazole-9-yl)butyl]phosphoric acid (MEO-4PACZ) was dissolved in an organic solvent (triethylene glycol, ethanol and ethyl acetate in a volume ratio of 10:60:30) to prepare a hole transport layer precursor solution, wherein the concentration of MEO-4PACZ was 0.5 mg / mL;

[0068] (3) Hole transport layer preparation: The hole transport layer precursor solution was deposited on the pretreated FTO conductive glass surface by inkjet printing. The inkjet printing conditions were: inkjet voltage of 12V, Y-axis speed of 800mm / s, resolution of 720×720, droplet volume of printing nozzle of 5pL, and jetting frequency of 12000Hz. After inkjet printing, the glass was moved to a 60℃ hot plate and heated for 3min for annealing. After annealing, the glass was naturally cooled to room temperature to prepare a hole transport layer with a thickness of 2nm.

[0069] (4) Preparation of perovskite layer: using Cs 0.12 FA 0.88 A PbI2 solution (using DMF and NMP in a volume ratio of 4:1 as solvents) was used as the perovskite precursor solution. The perovskite precursor solution was coated onto the hole transport layer by slit coating. The coating conditions included: a slit width of 200 μm and a coating speed of 15 mm / s. After coating, the layer was heated on a 100°C hot stage for 30 min and then cooled to room temperature to prepare a perovskite layer with a thickness of 500 nm.

[0070] (5) Electron transport layer preparation: C60 was used to perform thermal evaporation on the perovskite layer to prepare an electron transport layer with a thickness of 25 nm;

[0071] (6) Preparation of buffer layer: A buffer layer with a thickness of 8 nm was prepared by thermal evaporation of BCP (2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline);

[0072] (7) Perform P2 laser scribing;

[0073] (8) Metal electrode preparation: Cu was used for hot evaporation to prepare an electrode layer with a thickness of 100 nm;

[0074] (9) Perform P3 laser scribing and P4 laser edge cleaning to prepare perovskite solar cells.

[0075] Example 2

[0076] The organic solvent used in Example 2 is basically the same as that in Example 1, except that "triethylene glycol" is replaced with "triethyl phosphate"; the perovskite battery is prepared according to the method in Example 1.

[0077] Example 3

[0078] The organic solvent used in Example 3 is basically the same as that in Example 1, except that "ethyl acetate" is replaced with "n-hexane"; the perovskite battery is prepared according to the method in Example 1.

[0079] Example 4

[0080] The organic solvent used in Example 4 is basically the same as that in Example 1, except that "ethanol" is replaced with "ethylene glycol"; the perovskite battery is prepared according to the method in Example 1.

[0081] Example 5

[0082] The organic solvent used in Example 5 is basically the same as that in Example 1, except that "ethanol" is replaced with "N,N-dimethylformamide"; the perovskite battery is prepared according to the method in Example 1.

[0083] Example 6

[0084] The organic solvents used in Example 6 are basically the same as those in Example 4, except that the "triethylene glycol, ethylene glycol and ethyl acetate in a volume ratio of 10:60:30" is replaced with "triethylene glycol, ethylene glycol and ethyl acetate in a volume ratio of 30:60:10"; the perovskite battery is prepared according to the method of Example 4.

[0085] Example 7

[0086] The organic solvents used in Example 7 are basically the same as those in Example 4, except that the "triethylene glycol, ethylene glycol and ethyl acetate in a volume ratio of 10:60:30" is replaced with "triethylene glycol, ethylene glycol and ethyl acetate in a volume ratio of 10:80:10"; the perovskite battery is prepared according to the method of Example 4.

[0087] Example 8

[0088] The organic solvents used in Example 8 are basically the same as those in Example 4, except that the "triethylene glycol, ethylene glycol and ethyl acetate in a volume ratio of 10:60:30" is replaced with "triethylene glycol, ethylene glycol and ethyl acetate in a volume ratio of 30:30:40"; the perovskite battery is prepared according to the method of Example 4.

[0089] Comparative Example 1

[0090] The organic solvent used in Comparative Example 1 is basically the same as that in Example 1, except that ethanol is used as the solvent and perovskite solar cells are prepared according to the method in Example 1.

[0091] Comparative Example 2

[0092] The organic solvent used in Comparative Example 2 is basically the same as that in Example 1, except that triethylene glycol is used as the solvent; and perovskite solar cells are prepared according to the method in Example 1.

[0093] Comparative Example 3

[0094] The organic solvent used in Comparative Example 3 is basically the same as that in Example 1, except that ethyl acetate is used as the solvent; and perovskite solar cells are prepared according to the method in Example 1.

[0095] Comparative Example 4

[0096] The organic solvents used in Comparative Example 4 are basically the same as those in Example 1, except that the "triethylene glycol, ethanol and ethyl acetate in a volume ratio of 10:60:30" are replaced with "triethylene glycol and ethanol in a volume ratio of 10:90"; perovskite solar cells are prepared according to the method of Example 1.

[0097] Comparative Example 5

[0098] The organic solvents used in Comparative Example 5 are basically the same as those in Example 1, except that the "triethylene glycol, ethanol and ethyl acetate in a volume ratio of 10:60:30" are replaced with "triethylene glycol and ethyl acetate in a volume ratio of 10:90"; the perovskite battery is prepared according to the method of Example 1.

[0099] Comparative Example 6

[0100] The organic solvents used in Comparative Example 6 are basically the same as those in Example 1, except that the "triethylene glycol, ethanol and ethyl acetate in a volume ratio of 10:60:30" are replaced with "ethanol and ethyl acetate in a volume ratio of 70:30"; the perovskite battery is prepared according to the method of Example 1.

[0101] Comparative Example 7

[0102] The organic solvent used in Comparative Example 7 is basically the same as that in Example 1, except that "triethylene glycol" is replaced with "N,N-dimethylformamide"; and perovskite solar cells are prepared according to the method in Example 1.

[0103] Comparative Example 8

[0104] The organic solvents used in Comparative Example 8 and Example 5 are basically the same, except that "triethylene glycol, N,N-dimethylformamide and ethyl acetate in a volume ratio of 10:60:30" are replaced with "triethylene glycol and N,N-dimethylformamide in a volume ratio of 10:90"; perovskite solar cells are prepared according to the method of Example 5.

[0105] Experimental Example 1

[0106] The performance of the perovskite solar cells in Examples 1-8 and Comparative Examples 1-8 was tested:

[0107] JV tests were conducted using a calibrated AM1.5G standard solar simulator, with a starting voltage of 1.2V, a cutoff voltage of -0.1V, and a scan rate of 10mV / s. The short-circuit current (JSC), open-circuit voltage (VOC), fill factor (FF), and photoelectric conversion efficiency (PCE) of the perovskite solar cells in Examples 1-8 and Comparative Examples 1-8 were tested.

[0108] The test results are shown in Table 1.

[0109] Table 1 Performance of perovskite solar cells

[0110]

[0111]

[0112] The results in Table 1 show that, compared with Comparative Examples 1-8, the hole transport layer precursor solutions of Examples 1-8 of this application use organic solvents containing solvents A, B and C, and the perovskite solar cells prepared by these solutions achieve a photoelectric conversion efficiency of 20.14%-21.05% and a fill factor of 76.32%-78.57%, which significantly improves the device performance of the perovskite solar cells.

[0113] In Example 1 of this application, the hole transport layer precursor solution uses triethylene glycol, ethanol, and ethyl acetate in a volume ratio of 10:60:30 as organic solvents. The perovskite solar cell prepared with this solution exhibits the optimal PCE (21.05%). Among the organic solvents, triethylene glycol provides four hydrogen bond acceptor sites (each composed of oxygen atoms from two ether bonds and two hydroxyl groups), with a boiling point of 298°C. Triethylene glycol forms a hydrogen bond network with SAM molecules, promoting the orderly arrangement of SAM molecules. Simultaneously, triethylene glycol forms a hydrogen bond network with the hydroxyl groups on the pretreated FTO conductive glass surface, promoting the anchoring of SAM molecules to the substrate. Ethanol has good solubility for SAM molecules. Ethyl acetate has a low boiling point (77°C), preferentially evaporating during the hole transport layer preparation process to form a strong evaporation gradient, driving the transport and orderly arrangement of SAM molecules to the substrate interface. The synergistic effect of solvents A, B, and C results in a dense and uniform hole transport layer, giving the perovskite solar cell extremely high flyback distance (FF) (78.57%) and volume open charge (VOC) (11.55V), excellent charge extraction capability, and extremely low leakage current and recombination loss.

[0114] In Example 2 of this application, the hole transport layer precursor solution uses triethyl phosphate, ethanol, and ethyl acetate in a volume ratio of 10:60:30 as organic solvents. The PCE of the prepared perovskite solar cell is 20.53%. This indicates that triethyl phosphate, as solvent A, provides four hydrogen bond acceptor sites through the oxygen atoms in the four phosphate groups. At the same time, triethyl phosphate has a high boiling point of 215°C, which can improve the device performance of the perovskite solar cell.

[0115] Compared to Example 1, in Example 3 of this application, solvent C was replaced with n-hexane instead of ethyl acetate, and the PCE of the prepared perovskite solar cell decreased to 20.21%. This may be because n-hexane has a lower boiling point (69°C) and evaporates faster, and the evaporation gradient effect of the composition may be too intense, or the compatibility of n-hexane with the system may be slightly worse than that of ethyl acetate, resulting in a slightly lower degree of SAM molecular order, thereby slightly reducing the device performance of the perovskite solar cell.

[0116] In Examples 4-5 of this application, solvent B was ethylene glycol and N,N-dimethylformamide, respectively, and the PCE of the prepared perovskite solar cells were 20.14% and 20.25%, respectively. This indicates that perovskite solar cells prepared using either ethylene glycol or N,N-dimethylformamide as solvent B both exhibit high device performance.

[0117] In Examples 4 and 6-8 of this application, solvent A, solvent B, and solvent C, with a volume ratio of (10-30):(30-80):(10-40), were used to prepare perovskite solar cells with a PCE of 20.14%-20.75%. This indicates that the perovskite solar cells prepared using solvent A, solvent B, and solvent C with a volume ratio of (10-30):(30-80):(10-40) as organic solvents in the hole transport layer precursor solution all exhibit high device performance.

[0118] Compared to the hole transport layer precursor solution in Comparative Example 1, which used ethanol as a solvent, the hole transport layer precursor solution in Example 1 used triethylene glycol, ethanol, and ethyl acetate in a volume ratio of 10:60:30 as organic solvents. The resulting perovskite solar cell showed an increase in FF from 71.59% to 78.57% and PCE from 18.73% to 21.05%, representing an improvement of 12.4%. Example 2 used triethyl phosphate, ethanol, and... in a volume ratio of 10:60:30. Using ethyl acetate as the organic solvent, the flow factor (FF) of the prepared perovskite solar cell increased from 71.59% to 78.18%, and the perovskite electron potential (PCE) increased from 18.73% to 20.53%, an improvement of 9.6%. In Example 3, using triethylene glycol, ethanol, and n-hexane in a volume ratio of 10:60:30 as the organic solvent, the FF of the prepared perovskite solar cell increased from 71.59% to 77.06%, and the PCE increased from 18.73% to 20.21%, an improvement of 7.9%. This indicates that Comparative Example 1, using only ethanol, lacks the driving force of the volatilization gradient and the assistance of the hydrogen bond network. The SAM molecules are not arranged in an orderly and dense manner, leading to an increase in the series resistance of hole transport, thereby reducing the device performance of the perovskite solar cell.

[0119] Compared to the hole transport layer precursor solution in Comparative Example 2, which used triethylene glycol as a solvent, the hole transport layer precursor solution in Example 1 used triethylene glycol, ethanol, and ethyl acetate in a volume ratio of 10:60:30 as solvents. The resulting perovskite solar cell showed an increase in FF from 42.27% to 78.57% and PCE from 7.47% to 21.05%, representing an improvement of 181.8%. Examples 3-5 used triethylene glycol, solvent B, and solvent C in a volume ratio of 10:60:30 as organic solvents. The resulting perovskite solar cells showed an increase in FF from 42.27% to 76.32%-77.67% and PCE from 7.47% to 20.14%-20.25%, representing improvements of 169.6%-171.1%. This is because Comparative Example 2 only used triethylene glycol, which has a high boiling point (289°C). As a result, the solvent could not be completely removed in the subsequent annealing process. The solvent residue damaged the structure of the perovskite layer, hindered charge transport, and seriously affected the subsequent crystallization of the perovskite layer.

[0120] Compared to the hole transport layer precursor solution in Comparative Example 3, which used ethyl acetate as the organic solvent, the hole transport layer precursor solution in Example 1 used triethylene glycol, ethanol, and ethyl acetate in a volume ratio of 10:60:30 as the organic solvent. The resulting perovskite solar cell showed an increase in FF from 50.40% to 78.57% and PCE from 8.98% to 21.05%, representing an improvement of 134.4%. Examples 2 and 4-5 used a combination of solvent A, solvent B, and ethyl acetate. The resulting perovskite solar cells showed an increase in FF from 50.40% to 76.32%-78.18% and PCE from 8.98% to 20.14%-20.53%, representing improvements of 124.3%-128.6%. This is because Comparative Example 3 used only the low-boiling-point solvent ethyl acetate, which evaporated too quickly. This resulted in insufficient time for SAM molecules to diffuse, align, and anchor to the substrate, leading to the formation of a disordered, multi-defect hole transport layer.

[0121] Under the condition of using 10% (v / v) triethylene glycol as the organic solvent, compared with Comparative Examples 4-5 which only used 90% (v / v) ethanol or ethyl acetate, Example 1, using a combination of 60% (v / v) ethanol and 30% (v / v) ethyl acetate, improved the PCE of the perovskite solar cell from 14.74%-19.61% to 21.05%, and the FF from 65.95%-74.42% to 78.57%. This is because Comparative Example 4 lacked the most volatile solvent C to generate a strong gradient drive, relying mainly on heating and evaporation, resulting in lower self-assembly kinetics and order of SAM molecules compared to the three-component composite system. Ethanol is a highly soluble solvent for SAM; the absence of ethanol in Comparative Example 5 led to poor solubility and dispersibility of SAM molecules, easily forming aggregates and affecting film quality. This indicates that the use of a combination of triethylene glycol, ethanol, and ethyl acetate in this application can significantly improve the device performance of perovskite solar cells.

[0122] Compared to the hole transport layer precursor solution in Comparative Example 6, which used ethanol and ethyl acetate in a volume ratio of 70:30 as solvents, Examples 1-2 used 10% volume fraction solvent A (triethylene glycol or triethyl phosphate) instead of 10% volume fraction ethanol. The resulting perovskite solar cells showed an increase in flow factor (FF) from 70.56% to 78.18%-78.57%, and a PCE from 16.61% to 20.53%-21.05%, representing an improvement of 23.6%-26.7%. This indicates that solvent A contains four hydrogen bond acceptors, and the constructed hydrogen bond network is crucial for forming the highest quality self-assembled monolayer, further enhancing the PCE and FF of the perovskite solar cell.

[0123] Compared to Comparative Example 7, which used DMF, a solvent containing one hydrogen bond acceptor, Example 1 used triethylene glycol, a solvent containing four hydrogen bond acceptors, in combination with solvents B and C as the organic solvent for the hole transport layer precursor solution. The PCE of the prepared perovskite solar cell increased from 13.57% to 21.05%, an improvement of 55.1%. Example 2 used triethyl phosphate, a solvent containing four hydrogen bond acceptors, in combination with solvents B and C as the organic solvent for the hole transport layer precursor solution. The PCE of the prepared perovskite solar cell increased from 13.57% to 20.53%, an improvement of 51.3%. This indicates that using solvent A, which contains four hydrogen bond acceptors and has a boiling point in the range of 215℃-290℃, can significantly improve the device performance of perovskite solar cells.

[0124] Compared to Comparative Example 8, which used triethylene glycol and DMF in a volume ratio of 10:90 as the hole transport layer precursor solution, Example 5 used triethylene glycol, N,N-dimethylformamide, and ethyl acetate in a volume ratio of 10:60:30 as the organic solvent for the hole transport layer precursor solution. The resulting perovskite solar cell exhibited an increase in flux linkage (FF) from 44.05% to 76.32% and a PCE from 8.23% to 20.25%, representing an improvement of 146.1%. This is because Comparative Example 8 did not use solvent C during the hole transport layer preparation process, resulting in significant solvent residue that prevented the formation of an effective hole transport layer, thus significantly impacting the performance of the perovskite solar cell.

[0125] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0126] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A hole transport layer precursor solution, characterized in that, Including self-assembled single molecules and organic solvents; The organic solvents include solvent A, solvent B, and solvent C; Solvent A includes one or more of triethylene glycol and triethyl phosphate; Solvent B includes one or more of ethanol, isopropanol, n-propanol, butanol, ethylene glycol, and N,N-dimethylformamide; The solvent C includes one or more of ethyl acetate and n-hexane; The volume ratio of solvent A, solvent B and solvent C is (10-30):(30-80):(10-40); The mass-to-volume ratio of the self-assembled monomer to the organic solvent is (0.01 mg - 10 mg): 1 mL.

2. The hole transport layer precursor solution according to claim 1, characterized in that, The self-assembled monomolecules include one or more of the following: phosphate self-assembled monomolecules, silane self-assembled monomolecules, and thiol self-assembled monomolecules.

3. The hole transport layer precursor solution according to claim 2, characterized in that, The self-assembled phosphoric acid monomers include [4-(3,6-dimethoxy-9H-carbazole-9-yl)butyl]phosphoric acid, [2-(3,6-dimethoxy-9H-carbazole-9-yl)ethyl]phosphoric acid, [3-(3,6-dimethoxy-9H-carbazole-9-yl)propyl]phosphoric acid, [6-(3,6-dimethoxy-9H-carbazole-9-yl)hexyl]phosphoric acid, [2-(3,6-dimethyl-9H-carbazole-9-yl)ethyl]phosphoric acid, [3-(3,6-dimethyl-9H-carbazole-9-yl)propyl]phosphoric acid, [6-(3,6-dimethyl-9H-carbazole-9-yl)hexyl]phosphoric acid, [1-(3,6-dimethyl-9H-carbazole-9-yl)methyl]phosphoric acid, [4-( [3,6-Dimethyl-9H-carbazole-9-yl)butyl]phosphate, [8-(3,6-dimethyl-9H-carbazole-9-yl)octyl]phosphate, [1-(9H-carbazole-9-yl)methyl]phosphate, (2-(9H-carbazole-9-yl)ethyl)phosphate, [3-(9H-carbazole-9-yl)propyl]phosphate, [4-(9H-carbazole-9-yl)butyl]phosphate, [6-(9H-carbazole-9-yl)hexyl]phosphate, [8-(9H-carbazole-9-yl)octyl]phosphate, [4-(N,N-di(4-methoxyphenylamino)phenyl)propyl]phosphate, 2,3,4,5,6-pentafluorobenzyl phosphate, [2-(9H-9,-phenyl-3,3,-di-carbazole-9-yl)ethyl]phosphate [4-(9H-9,-phenyl-3,3,-di-carbazole-9-yl)butyl]phosphoric acid, [(4-(diphenylamino)phenyl)ethyl]phosphoric acid, [(4-(diphenylamino)phenyl)propyl]phosphoric acid, [4-(10H-phenthiazin-10-yl)butyl]phosphoric acid, [2-(7H-dibenzocarbazole-7-yl)ethyl]phosphoric acid, [4-(7H-dibenzocarbazole-7-yl)butyl]phosphoric acid, [3-(3,6-dibromo-9H-carbazole-9-yl)propyl]phosphoric acid, [4-(3,6-dibromo-9H-carbazole-9-yl)butyl]phosphoric acid, [6-(3,6-dibromo-9H-carbazole-9-yl)hexyl]phosphoric acid, [1-(3,6-di-tert-butyl-9H-carbazole]phosphoric acid, [4-(9H-9,-phenyl-3,3,-di-carbazole-9-yl)butyl]phosphoric acid, [4-(9H-9,-phenyl-3, ...tert-butyl-9H-carbazole]phosphoric acid, [4 [-9-yl)methyl]phosphoric acid, [2-(3,6-di-tert-butyl-9H-carbazole-9-yl)ethyl]phosphoric acid, [3-(3,6-di-tert-butyl-9H-carbazole-9-yl)propyl]phosphoric acid, [4-(3,6-di-tert-butyl-9H-carbazole-9-yl)butyl]phosphoric acid, [6-(3,6-di-tert-butyl-9H-carbazole-9-yl)hexyl]phosphoric acid, [8-(3,6-di-tert-butyl-9H-carbazole-9-yl)octyl]phosphoric acid, [1-(3,6-diphenyl-9H-carbazole-9-yl)methyl]phosphoric acid, [2-(3,6-diphenyl-9H-carbazole-9-yl)ethyl]phosphoric acid, [3-(3,6-diphenyl ...phenyl-9H-carbazole-9-yl)propyl]phosphoric acid, [4-(3,6-diphenyl-9H-carbazole-9-yl)ethylOne or more of the following: [6-(3,6-diphenyl-9H-carbazole-9-yl)butyl]phosphate, [8-(3,6-diphenyl-9H-carbazole-9-yl)hexyl]phosphate, [2-(10H-phenoxazine-10-yl)ethyl]phosphate, [4-(3,7-dibromo-10H-phenthiazine-10-yl)butyl]phosphate, and [4-(3,7-dibromo-10H-phenoxazine-10-yl)butyl]phosphate; The silane self-assembled monomolecules include one or more of 3-aminopropyltriethoxysilane, 3-epoxypropoxypropyltrimethoxysilane, γ-aminopropyltriethoxysilane, 3-mercaptopropyltriethoxysilane, and tridecafluorooctyltriethoxysilane. The thiol self-assembled monomers include one or more of undecylthiol, 10-mercapto-1-decaol, 6-mercapto-hexanoic acid, 11-mercaptoundecanoic acid, and 16-mercaptohexadecanoic acid.

4. A method for preparing a hole transport layer, characterized in that, Includes the following steps: The hole transport layer is prepared by depositing and annealing the hole transport layer precursor solution according to any one of claims 1-3.

5. The method for preparing a hole transport layer according to claim 4, characterized in that, Deposition methods include: blade coating, spin coating, slot coating, inkjet printing, or screen printing.

6. The method for preparing a hole transport layer according to claim 4, characterized in that, Annealing conditions include: temperature of 50℃-120℃ and time of 1min-20min.

7. A hole transport layer, characterized in that, Prepared by the method for preparing the hole transport layer according to any one of claims 4-6.

8. The hole transport layer according to claim 7, characterized in that, The thickness of the hole transport layer is 1nm-10nm.

9. An application of a hole transport layer in a perovskite solar cell, characterized in that, The hole transport layer is a hole transport layer prepared by the method of any one of claims 4-6 or a hole transport layer as described in claim 7 or 8.

10. A perovskite solar cell, characterized in that, It includes a conductive substrate, a hole transport layer, a perovskite layer, an electron transport layer, a buffer layer, and an electrode layer stacked in sequence. The hole transport layer is a hole transport layer prepared by the method of any one of claims 4-6 or a hole transport layer as described in claim 7 or 8.

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