The performance of organic-inorganic perovskite solar cells depends largely on the quality of perovskite film. Currently, various methods are applied to prepare the perovskite film. Among them, the two-step method is counted as a promising candidate to obtain high-quality perovskite film. In this study, we attain a special platelet-like PbI₂ films by applying pure water to cover wet PbI₂ film and standing for a period of time. The unique morphology contributes to the entry of organic cations solution into the PbI₂ and promoting its reaction with PbI₂, which reducing the residual amount of PbI₂ in the perovskite film. Compared to the traditional two-step method, water processing method can obtain a high-quality perovskite film with enlarged grain size, improved crystallization, and prolonged carrier lifetime. As a result, the efficiency of the prepared device based on the film has increased from 17.90% without water processing to 20.14% of water processing. Which demonstrates that this solvent engineering for PbI₂ film opens up a possibility to prepare high-quality perovskite in a two-step method and obtain highly efficient perovskite solar cells.

有机-无机钙钛矿太阳能电池的性能很大程度上取决于钙钛矿薄膜的质量。目前，采用多种方法制备钙钛矿薄膜。其中，两步法被认为是获得高质量钙钛矿薄膜的有希望的候选方法。在这项研究中，我们通过用纯水覆盖湿的 PbI ₂薄膜并静置一段时间来获得一种特殊的片状 PbI ₂薄膜。的独特的形态有助于有机阳离子溶液进入到碘化铅₂和促进其对PBI反应₂，这减少碘化铅的残留量₂在钙钛矿薄膜中。与传统的两步法相比，水处理法可以获得晶粒尺寸增大、结晶度提高和载流子寿命延长的高质量钙钛矿薄膜。结果，基于薄膜制备的器件的效率从没有水处理的17.90%提高到水处理的20.14%。这表明这种 PbI ₂薄膜的溶剂工程开辟了以两步法制备高质量钙钛矿并获得高效钙钛矿太阳能电池的可能性。