A method for preparing perovskite thin films in perovskite solar cells by solution pumping and ventilating method

Abstract

The invention provides a method for preparing a perovskite film in a perovskite solar cell by using a solution pumping and ventilating method. The perovskite liquid film coated on the surface of the substrate is placed at a temperature of 999999°C where the partial pressure of the solvent is lower than the current temperature of the solvent. % of the saturated vapor pressure environment for pumping and drying. During the drying process or after complete drying, a gas that does not chemically react with the perovskite is introduced, thereby accelerating solvent evaporation or solvent molecules leaving the environment by diluting the concentration of solvent molecules. . By controlling the drying process conditions, the heterogeneous nucleation and growth on the surface of the substrate can form a uniform and dense perovskite film. The invention can accelerate the drying of the liquid film, and make the solvent vapor molecules leave the film surface quickly, and obtain a perovskite film with a uniform and dense structure, thereby avoiding the current leakage caused by the loopholes in the perovskite film, which is beneficial to the realization of high-efficiency solar cells, and has the advantages of The method has the advantages of simple operation, easy realization, low cost, high repeat accuracy, and easy industrialization.

Description

technical field [0001] The invention belongs to the fields of material science technology, film preparation technology and solar cell preparation technology, and in particular relates to a method for preparing a perovskite film in a perovskite solar cell by using a solution pumping and ventilating method. Background technique [0002] In the field of photovoltaics, organic-metal halides with a perovskite structure, as a light-absorbing material, have attracted great attention in the photovoltaic industry due to their unique properties. The conversion efficiency of perovskite solar cells has increased by leaps and bounds in recent years, surpassing 20%. As the basic material for photoelectric conversion in perovskite solar cells, perovskite thin films are the key and core of perovskite solar cells. The preparation process mainly adopts solution method, including one-step method and two-step method. Although the one-step method is relatively simple to operate, there are some ...

AI Technical Summary

Problems solved by technology

Although the one-step method is relatively simple to operate, there are some problems in the prepared perovskite film: the uniformity and crystallinity of the film cannot be effectively controlled, the grains of the perovskite film are coarse and dendritic, and the coverage of the substrate is low, resulting in Electrons are extremely easy to recombine with holes during transport, resulting in poor performance and insufficient stability of perovskite solar cells

The existing technical solutions are mainly through the natural drying of the solvent in the solution or direct heating and drying, it is difficult to achieve good control of the crystallization characteristics of the perovskite film, so a one-step method cannot obtain a uniform and dense perovskite film

It has been reported that speeding up the evaporation by air blowing can increase the drying speed of the solution to a certain extent, but the air blowing will easily cause the solution surface to be unstable, which will cause uneven surface fluctuations of the perovskite film, which may cause the substrate to be exposed and affect the perovskite solar cell. Uniformity and photoelectric performance, difficult to industrial application

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