Lu, Jing; Yang, Tinghuan; Niu, Tianqi; Bu, Nuo; Zhang, Yalan; Wang, Shiqiang; Fang, Junjie; Chang, Xiaoming; Luo, Tao; Wen, Jialun; Yang, Yingguo; Ding, Zicheng; Zhao, Kui; Liu, Shengzhong (Frank)

ENERGY & ENVIRONMENTAL SCIENCE

2022, 15, 1754-5692

Lu, Jing; Yang, Tinghuan; Niu, Tianqi; Bu, Nuo; Zhang, Yalan; Wang, Shiqiang; Fang, Junjie; Chang, Xiaoming; Luo, Tao; Wen, Jialun; Yang, Yingguo; Ding, Zicheng; Zhao, Kui; Liu, Shengzhong (Frank)

The use of layered perovskites is an important strategy to stabilize a formamidinium (FA) based photoactive alpha-FAPbI(3) phase. However, the growth mechanism of FA-based layered perovskites and its influence on their physical properties have not yet been reported. Herein, we demonstrate an inclusive study on the growth, structure and optoelectronic properties of FA-based Ruddlesden-Popper (RP) type perovskites M(2)FA(n-1)Pb(n)I(3n+1) (M = benzylamine (PMA) or FA) during two-step sequential deposition, revealing the transformation of dominant layered perovskites from PMA(2)FA(n-1)Pb(n)I(3n+1) to novel FA(2)FA(n-1)Pb(n)I(3n+1) with increasing FA : PMA ratios in precursors, and increased n values from top to bottom for the former case while a uniform distribution for the latter case. Moreover, we investigated the charge transport kinetics between quantum wells and illustrate the application of these structures in perovskite solar cells with a power conversion efficiency that exceeds 19%, accompanied by enhanced film stability in contrast to 3D analogs.