Unveiling facet-dependent degradation and facet engineering for stable perovskite solar cells

• 成果类型: Article
• 署名作者: Ma, Chunqing; T. Eickemeyer, Felix; Lee, Sun-Ho; Kang, Dong-Ho; Kwon, Seok Joon; Gratzel, Michael; Park, Nam-Gyu
• 署名单位: Sungkyunkwan University (SKKU); Sungkyunkwan University (SKKU); Swiss Federal Institutes of Technology Domain; Ecole Polytechnique Federale de Lausanne; Sungkyunkwan University (SKKU); Sungkyunkwan University (SKKU)
• 刊物名称: SCIENCE
• ISSN/ISSBN: 0036-12962
• DOI: 10.1126/science.adf3349
• 发表日期: 2023-01-13
• 页码: 173-178
• 关键词: surfaces; films

摘要

A myriad of studies and strategies have already been devoted to improving the stability of perovskite films; however, the role of the different perovskite crystal facets in stability is still unknown. Here, we reveal the underlying mechanisms of facet-dependent degradation of formamidinium lead iodide (FAPbI3) films. We show that the (100) facet is substantially more vulnerable to moisture-induced degradation than the (111) facet. With combined experimental and theoretical studies, the degradation mechanisms are revealed; a strong water adhesion following an elongated lead-iodine (Pb-I) bond distance is observed, which leads to a d-phase transition on the (100) facet. Through engineering, a higher surface fraction of the (111) facet can be achieved, and the (111)-dominated crystalline FAPbI3 films show exceptional stability against moisture. Our findings elucidate unknown facet-dependent degradation mechanisms and kinetics.