Wearable Tin‐Based Perovskite Solar Cells Achieved by a Crystallographic Size Effect
Li Rao, Xiangchuan Meng, Shuqin Xiao, Zhi Xing, Qingxia Fu, Hongyu Wang, Chenxiang Gong, Ting Hu, Xiaotian Hu, Rui Guo, Yiwang Chen
Abstract
Abstract Tin‐based perovskite solar cells (PSCs) demonstrate a potential application in wearable electronics due to its hypotoxicity. However, poor crystal quality is still the bottleneck for achieving high‐performance flexible devices. In this work, graphite phase‐C 3 N 4 (g‐C 3 N 4 ) is applied into tin‐based perovskite as a crystalline template, which delays crystallization via a size‐effect and passivates defects simultaneously. The double hydrogen bond between g‐C 3 N 4 and formamidine cation can optimize lattice matching and passivation. Moreover, the two‐dimensional network structure of g‐C 3 N 4 can fit on the crystals, resulting an enhanced hydrophobicity and oxidation resistance. Therefore, the flexible tin‐based PSCs with g‐C 3 N 4 realize a stabilized power conversion efficiency (PCE) of 8.56 % with negligible hysteresis. In addition, the PSCs can maintain 91 % of the initial PCE after 1000 h under N 2 environment and keep 92 % of their original PCE after 600 cycles at a curvature radius of 3 mm.