Mechanochemistry Advances High‐Performance Perovskite Solar Cells

• Published in: Advanced materials (Weinheim) 2022-02, Vol.34 (6), p.e2107420-n/a
• Main Authors: Zhang, Yuzhuo, Wang, Yanju, Yang, Xiaoyu, Zhao, Lichen, Su, Rui, Wu, Jiang, Luo, Deying, Li, Shunde, Chen, Peng, Yu, Maotao, Gong, Qihuang, Zhu, Rui
• Format: Article
• Language: English
• Subjects: Carrier transport; Commercialization; Crystal defects; Crystal structure; Crystallization; Energy conversion efficiency; Mass production; Materials science; Maximum power; mechanochemistry; Nucleation; perovskite solar cells; Perovskites; Photovoltaic cells; Precursors; pure‐phase perovskite powder; Relative humidity; Solar cells; stable storage; Storage stability
• ISSN: 0935-9648; 1521-4095
• DOI: 10.1002/adma.202107420

A prerequisite for commercializing perovskite photovoltaics is to develop a swift and eco‐friendly synthesis route, which guarantees the mass production of halide perovskites in the industry. Herein, a green‐solvent‐assisted mechanochemical strategy is developed for fast synthesizing a stoichiometric δ‐phase formamidinium lead iodide (δ‐FAPbI3) powder, which serves as a high‐purity precursor for perovskite film deposition with low defects. The presynthesized δ‐FAPbI3 precursor possesses high concentration of micrometer‐sized colloids, which are in favor of preferable crystallization by spontaneous nucleation. The resultant perovskite films own preferred crystal orientations of cubic (100) plane, which is beneficial for superior carrier transport compared to that of the films with isotropic crystal orientations using “mixture of PbI2 and FAI” as precursors. As a result, high‐performance perovskite solar cells with a maximum power conversion efficiency of 24.2% are obtained. Moreover, the δ‐FAPbI3 powder shows superior storage stability for more than 10 months in ambient environment (40 ± 10% relative humidity), being conducive to a facile and practical storage for further commercialization. A mechanochemical route to prepare stoichiometric‐pure and air‐stable δ‐FAPbI3 powders is developed, which can be stored for more than 10 months in ambient environment. Redissolving the δ‐FAPbI3 powders can generate a high concentration of large‐sized polyiodide colloids, which can serve as nuclei to promote heterogeneous nucleation for perovskite films. As a result, a competitive solar cell efficiency of 24.22% is achieved.