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CN-122003081-A - Method for preparing perovskite film by solution two-step method and perovskite solar cell

CN122003081ACN 122003081 ACN122003081 ACN 122003081ACN-122003081-A

Abstract

The invention discloses a method for preparing a perovskite film by a solution two-step method and a perovskite solar cell, the preparation method comprises the following steps of adding a low-temperature volatilization/sublimation component into a PbX 2 solution to obtain a precursor solution, coating the precursor solution on the surface of a substrate, and annealing to obtain the PbX 2 film; and (3) coating the PbX 2 film with an organic ammonium salt solution, and annealing to obtain the perovskite film. According to the invention, the low-temperature volatilization/sublimation component is introduced into the PbX 2 precursor solution, and the PbX 2 film forms a loose porous structure of the communicated pore channels by utilizing the characteristic that the component is heated and escapes in the annealing process. The structure can provide sufficient channels for permeation of organic ammonium salt solution, increase the contact area of PbX 2 and organic cations, promote the full reaction of the PbX 2 and the organic cations, optimize the crystallization quality of the perovskite thin film, inhibit non-radiative recombination of carriers, and finally improve the photoelectric performance of the perovskite device.

Inventors

  • XIONG YUAN
  • Request for anonymity

Assignees

  • 深圳翊阳科技有限公司

Dates

Publication Date
20260508
Application Date
20251231

Claims (10)

  1. 1. The method for preparing the perovskite film by the solution two-step method is characterized by comprising the following steps of: (1) Adding a low-temperature volatilization/sublimation component into a PbX 2 solution to obtain a PbX 2 precursor solution, coating the PbX 2 precursor solution on the surface of a substrate, and annealing at 70-100 ℃ to obtain a PbX 2 film, wherein the volatilization or sublimation temperature of the low-temperature volatilization/sublimation component is 60-100 ℃, the concentration of the low-temperature volatilization/sublimation component in the PbX 2 precursor solution is 0.03-0.15 mg/mL, and X is one or more of Cl, br and I; (2) And (3) coating an organic ammonium salt solution on the PbX 2 film obtained in the step (1), and annealing at 100-145 ℃ to obtain the perovskite film.
  2. 2. The method according to claim 1, wherein in step (1), the solvent of the PbX 2 solution is selected from one or more of N, N-dimethylformamide, dimethyl sulfoxide, dimethoxyethanol, γ -butyrolactone, 2-mercaptoethanol, ethylene glycol dimethyl ether, N-methylpyrrolidone, acetonitrile, 2-pyrrolidone, 1, 3-dimethyl-3, 4,5, 6-tetrahydro-2-pyrimidinone, and methyl benzene sulfoxide.
  3. 3. The method according to claim 1, wherein in step (1), the low-temperature volatile/sublimating component is selected from one or more of wax, naphthalene, biphenyl, anthracene compound, benzoquinone compound, and halogenated benzene.
  4. 4. The method according to claim 1, wherein in the step (1), the coating method is spin coating, and the spin coating is performed at a rotation speed of 1000-8000 rpm for a time of 10-60 s.
  5. 5. The method of claim 1, wherein in step (1), the annealing treatment is performed for a period of time ranging from 1 to 5 min, and in step (2), the annealing treatment is performed for a period of time ranging from 10 to 30 min.
  6. 6. The method according to claim 1, wherein in step (2), the organic ammonium salt is selected from one or more of formamidine iodine, methamidodide and methamidochloride.
  7. 7. The method according to claim 1, wherein in the step (2), the coating method is spin coating, and the spin coating is performed at a rotation speed of 1000-8000 rpm for a time of 10-60 s.
  8. 8. A perovskite thin film prepared by the method of any one of claims 1-7.
  9. 9. A perovskite solar cell, characterized in that it comprises the perovskite thin film of claim 8.
  10. 10. The perovskite solar cell according to claim 9, comprising a conductive substrate or a laminated bottom cell, and an electron transport layer, a perovskite thin film according to claim 8, a hole transport layer, and a metal electrode sequentially provided on one side of the conductive substrate or laminated bottom cell.

Description

Method for preparing perovskite film by solution two-step method and perovskite solar cell Technical Field The invention relates to the technical field of perovskite solar cells, in particular to a method for preparing a perovskite film by a solution two-step method and a perovskite solar cell. Background The perovskite material has excellent light absorption performance, high carrier mobility and solution processability, and the solution processing technology of the perovskite material greatly reduces the manufacturing cost of the photovoltaic device, thereby laying an important foundation for large-scale popularization of the photovoltaic technology. At present, the preparation method of the perovskite film is mainly divided into two main types of a one-step method and a two-step method, wherein the one-step method is to directly prepare perovskite precursors meeting the stoichiometric ratio into a homogeneous solution, and the perovskite film is obtained through high-temperature annealing crystallization after film formation by solution processing modes such as spin coating, knife coating and the like. The method has the advantages of simple and convenient process flow, high production efficiency and the like, is limited by the fact that the perovskite crystallization process is too fast in speed and difficult to accurately regulate and control, and is easy to cause defects of uneven film crystallization quality, disordered grain size distribution, further generation of holes, cracks, component segregation and the like, and meanwhile, the repeatability of device preparation is poor, so that the large-scale application of the device in high-performance photovoltaic devices is severely limited. The two-step method adopts a step-by-step sequential preparation strategy, firstly, a stable inorganic PbX 2 skeleton film is formed by annealing and crystallizing a PbX 2 (X is selected from one or more of Cl, br and I) precursor solution, then organic components (such as FAI, MAI and the like) or other functional components are subjected to ion contact and diffusion reaction with the PbX 2 film, and a complete perovskite crystal structure is constructed by utilizing chemical reaction among the components. Compared with a one-step method, the two-step method can more accurately control the crystallization kinetics process of perovskite, the prepared perovskite has larger crystal grains, the compactness and uniformity of the film are better, and the performance stability of the device is also more advantageous. However, the conventional two-step method still has the defects that on one hand, the PbX 2 film prepared by the conventional process tends to form a compact lamellar structure, subsequent organic components or other functional components need to gradually permeate into the film from the surface, so that permeation paths are limited, the reaction is insufficient, and the uniform reaction in all regions is difficult to realize, on the other hand, the reaction of the organic components and an inorganic PbX 2 skeleton is difficult to strictly follow the stoichiometric ratio, unreacted PbX 2 or organic components are easy to remain, and then defects (such as lattice distortion, vacancy defects and the like) of a perovskite crystal structure are caused, so that the photoelectric conversion efficiency, long-term stability and batch preparation repeatability of a device are obviously reduced. In addition, chinese patent CN116322230a discloses a passivation method and a photovoltaic device for preparing a perovskite thin film based on a two-step method, which prepares a PbX 2 thin film in a first step, pre-prepares a APbX 3 perovskite single crystal into a polar solution, and adds the polar solution as an additive into a second-step organic component solution, and enhances the diffusion capacity of an organic component in a PbX 2 layer by using the permeation enhancement effect of a polar solvent, so as to improve the quality of the thin film. Chinese patent CN116600615A discloses a perovskite thin film preparation method and solar cell device application, which modifies organic ligand material on the annealed lead iodide thin film surface to form two-dimensional perovskite seed crystal, and induces three-dimensional perovskite crystallization through the seed crystal, thereby obtaining high quality perovskite thin film. However, the above method depends on a specific polar solvent system or requires additional steps such as seed crystal preparation and surface modification, which not only increases the process complexity and production cost, but also may introduce new interface defects or compatibility problems, and thus it is difficult to realize collaborative optimization of process simplification and performance improvement. Therefore, the perovskite film preparation method which has strong process compatibility and controllable cost, can improve the PbX 2 film structure and promote the full reaction of organic c