Significant progress has been made in perovskite solar cells by various effective film-forming methods. Solution-process methods for the perovskite film appropriate under ambient conditions are desired to be explored for the practical industrialization. Here, a secondary crystal growth strategy is developed for the fabrication of perovskite film in ambient atmosphere. By this method, the conversion from PbI₂ to CH₃NH₃PbI₃ on the planar substrate can be completed, overcoming the limitation of standard sequential deposition. After secondary growth, high-quality crystals are obtained and compact densely to form a pinhole-free film. Exceeding 17% of power conversion efficiency is achieved for planar CH₃NH₃PbI₃ devices by controlling the reaction time of two stages carefully. This method can be easily controlled, reproduced and performed in the ambient, which meets the industrial requirements for highly efficient, low cost planar perovskite solar cells.

通过各种有效的成膜方法，钙钛矿太阳能电池已经取得了重大进展。对于实际工业化，需要探索适用于环境条件的钙钛矿膜的固溶处理方法。在此，开发了用于在环境气氛中制造钙钛矿薄膜的二次晶体生长策略。通过这种方法，可以完成在平面基板上从PbI ₂到CH ₃ NH ₃ PbI ₃的转化，克服了标准顺序沉积的局限性。在二次生长之后，获得了高质量的晶体并致密地压实以形成无针孔的膜。平面CH ₃ NH的功率转换效率超过17％₃ PbI ₃器件通过仔细控制两个阶段的反应时间。该方法可以在环境中轻松控制，复制和执行，满足了高效，低成本平面钙钛矿太阳能电池的工业需求。