2D BA<sub>2</sub>PbI<sub>4</sub> Regulating PbI<sub>2</sub> Crystallization to Induce Perovskite Growth for Efficient Solar Cells
Cong Shao, Jiandong He, Guosheng Niu, Yuan Dong, Kaiyi Yang, Xiaofei Cao, Jizheng Wang, Haixia Yang
Abstract
Abstract Using seeds to control the crystallization of perovskite film is an effective strategy for achieving high‐efficiency perovskite solar cells (PSCs). Owing to their excellent environmental stability brought by their long alkyl chain, n‐butylammonium (BA) cations are widely used for fabricating efficient and stable PSCs. However, BA‐based 2D perovskite is seldom been investigated as a seed. Here, BA 2 PbI 4 is employed to regulate the crystallization of PbI 2 , acting as nucleation centers. As a result, porous PbI 2 film with high crystallinity is obtained, which allows the realization of perovskite film with preferential crystal orientations of (001) and large grain size of over 2 µm. The corresponding PSC achieves a high power conversion efficiency (PCE) of 24.30% and exhibits satisfactory stability, retaining 91.70% of the initial PCE after 300 h of thermal aging at 85°C.