A Low‐Temperature Additive‐Involved Leaching Method for Highly Efficient Inorganic Perovskite Solar Cells
Xiuhong Sun, Zhipeng Shao, Yi Rao, Hongguang Meng, Caiyun Gao, Chen Chen, Dachang Liu, Peiliang Lv, Zhipeng Li, Xiao Wang, Guanglei Cui, Shuping Pang
Abstract
Abstract Inorganic CsPbI 3 perovskite with an optical bandgap ranging from 1.67 to 1.75 eV is a promising light‐harvesting material as a top cell in tandem solar cells, but its high fabrication temperature can damage the middle layers or the bottom subcells. Here, an additive‐involved leaching method to fabricate CsPbI 3 perovskite films is demonstrated, which can decrease the preparation temperature to 100 °C. The CsPbI 3 perovskite films with high crystallinity are achieved by a solution assisted reaction between DMAPbI 3 and Cs 4 PbI 6 with the leaching of DMA + , Cs + , and I − . The as‐prepared CsPbI 3 perovskite films exhibit much superior stability compared to their high‐temperature counterparts. As a result, a power conversion efficiency of over 16% is obtained, and the unencapsulated device maintains over 93% of the initial efficiency after aging for 30 days in air with a relative humidity of 10%.