CN-122003082-A - Method for forming monocrystalline perovskite film and perovskite film

Abstract

The application provides a method for forming a single crystal perovskite film and the perovskite film, the method comprises the following steps of preparing perovskite precursor solution by perovskite precursor, diethanolamine and solvent, wherein the perovskite precursor at least comprises lead iodide; the perovskite precursor solution is used as a raw material, and a single crystal perovskite film is formed through a space-limited growth process. Based on the characteristics of a single crystal growth process, diethanolamine is introduced into a perovskite precursor solution, and the particle size of precursor particles is controlled by utilizing the coordination effect of the diethanolamine and lead iodide and a complex thereof, so that a high-quality single crystal perovskite film is obtained.

Inventors

• ZOU GUIFU
• ZHAO GUOXIANG
• ZHANG RONG
• LU ZHENG
• TIAN DEYU

Assignees

• 苏州大学
• 苏州益恒能源科技有限公司

Dates

Publication Date

20260508

Application Date

20260410

Claims (10)

1. 1. A method for forming a single crystal perovskite thin film, comprising the steps of: s1, preparing a perovskite precursor, diethanolamine and a solvent to form a perovskite precursor solution, wherein the perovskite precursor at least comprises lead iodide; S2, forming a single crystal perovskite film by using the perovskite precursor solution as a raw material through a space-limited growth process.
2. 2. The method for forming a single crystal perovskite thin film according to claim 1, wherein in step S1, the perovskite precursor is composed of a first precursor having an AX structure and a second precursor having a BX 2 structure, the second precursor including at least lead iodide; wherein A is a monovalent cation, B is a divalent metal cation, and X is a halogen anion.
3. 3. A method of forming a single crystal perovskite thin film according to claim 2, wherein the monovalent cations include one or more of formamidine cations, methylammonium cations, cesium ions and rubidium ions; the divalent metal cations include one or more of lead ions and tin ions; the halide anions include one or more of iodide, bromide, and chloride.
4. 4. The method for forming a single crystal perovskite thin film according to claim 1, wherein the concentration of diethanolamine in the perovskite precursor solution is 1-5 mol%.
5. 5. The method for forming a single crystal perovskite thin film according to claim 1, wherein in step S2, the spatial confinement growth process comprises introducing the perovskite precursor solution into a two-dimensional confinement space and performing a heat-preservation treatment to crystallize the perovskite precursor solution, thereby forming the single crystal perovskite thin film.
6. 6. The method for forming a single crystal perovskite thin film according to claim 5, wherein the process temperature of the heat preservation treatment is 110 ℃ to 130 ℃ and the crystallization time is 10 to 15 hours.
7. 7. The method of forming a single crystal perovskite thin film as claimed in claim 5, wherein in step S2, the spatial confinement growth process comprises: Combining two substrates to form the two-dimensional finite field space; injecting the perovskite precursor solution into the two-dimensional finite space, and filling the two-dimensional finite space through capillary action; and carrying out heat preservation treatment on the substrate to crystallize the perovskite precursor solution, so as to form the single crystal perovskite film.
8. 8. The method for forming a single crystal perovskite thin film according to claim 1, wherein in step S1, the solvent is one or more of N, N-dimethylformamide, dimethyl sulfoxide, γ -butyrolactone, and N-methylpyrrolidone.
9. 9. The method of forming a single crystal perovskite thin film according to claim 1, wherein in step S1, the particle size in the perovskite precursor solution is made to be between 1 nm and 10nm by adding the diethanolamine.
10. 10. A single crystal perovskite thin film, characterized in that it is produced by a method for forming a single crystal perovskite thin film according to any one of claims 1 to 9.

Description

Method for forming monocrystalline perovskite film and perovskite film Technical Field The application relates to the field of perovskite solar cells, in particular to a method for forming a single crystal perovskite film and the perovskite film. Background Perovskite solar cells have become one of the most competitive candidates in the next generation of photovoltaic technology due to their excellent photovoltaic properties, solution processability, and potentially low manufacturing costs. In the existing perovskite battery, a perovskite light absorption layer is usually formed by adopting a slit coating or spin coating process, the obtained perovskite light absorption layer is a polycrystalline film, and a large number of crystal boundaries and surface defects existing in a polycrystalline structure are easy to cause high defect density, so that the photoelectric conversion efficiency of the device is lower. Compared with the polycrystalline film, the single crystal perovskite film has the advantages of low defect state density, high carrier mobility, long carrier recombination life and the like. Although some documents have proposed that the preparation of single crystal perovskite thin films can be achieved through a space-limited domain process, crystal lattice vacancies and dislocations are still easily generated during crystallization, resulting in a photoelectric conversion efficiency of the single crystal thin films of less than 20% and an efficiency decay rate of more than 30% under illumination. Therefore, it is necessary to further improve the existing single crystal perovskite thin film forming process to solve the problem that lattice defects are easily generated in the thin film during the growth process, and reduce the defect density of the thin film. It should be noted that the foregoing description of the background art is only for the purpose of providing a clear and complete description of the technical solution of the present application and is presented for the convenience of understanding by those skilled in the art. The above-described solutions are not considered to be known to the person skilled in the art simply because they are set forth in the background of the application section. Disclosure of Invention The invention aims to provide a growth method of a single crystal perovskite film, so as to obtain higher crystal quality and photoelectric conversion efficiency of a device. In order to solve the above problems, in a first aspect, the present application provides a method for forming a single crystal perovskite thin film, comprising the steps of: s1, preparing a perovskite precursor, diethanolamine and a solvent to form a perovskite precursor solution, wherein the perovskite precursor at least comprises lead iodide; S2, forming a single crystal perovskite film by using the perovskite precursor solution as a raw material through a space-limited growth process. Based on the characteristics of a single crystal growth process, diethanolamine is introduced into a perovskite precursor solution, and the particle size of precursor particles is controlled by utilizing the coordination effect of the diethanolamine and lead iodide and a complex thereof, so that a high-quality single crystal perovskite film is obtained. In the step S1, the perovskite precursor is composed of a first precursor with an AX structure and a second precursor with a BX 2 structure, wherein the second precursor at least comprises lead iodide, A is monovalent cation, B is divalent metal cation, and X is halogen anion. The scheme has high compatibility with the prior art, and is applicable to most perovskite systems. The monovalent cations include one or more of formamidine cations, methylammonium cations, cesium ions, and rubidium ions, the divalent metal cations include one or more of lead ions and tin ions, and the halide anions include one or more of iodide ions, bromide ions, and chloride ions. The scheme has high compatibility with the prior art, and is applicable to most perovskite systems. In the perovskite precursor solution, the concentration of the diethanolamine is 1-5 mol%. In this range, high quality crystallization can be realized, and the additive is not excessively added, but is wrapped in perovskite lattices in the crystal growth process, so that the perovskite crystal becomes a new defect source. In the step S2, the space confinement growth process comprises the steps of introducing the perovskite precursor solution into a two-dimensional confinement space, and performing heat preservation treatment to crystallize the perovskite precursor solution to form the single crystal perovskite film. The process temperature of the heat preservation treatment is 110-130 ℃, and the crystallization time is 10-15 hours. In the step S2, the space-limited growth process comprises the steps of combining two substrates to form the two-dimensional limited space, injecting the perovskite precursor solution into the