Optimizing Blade‐Coated Tin–lead Perovskite Solar Cells and Tandems with Multi‐Carboxyl and Amino Group Integration
Weicheng Shen, Hongyi Fang, Dexin Pu, Wenwen Zheng, Xuhao Zhang, Guang Li, Lishuai Huang, Shun Zhou, Weiqing Chen, Yuan Zhou, Zhuo Feng, Jiwei Liang, Jin Zhou, Pingli Qin, Guojia Fang, Weijun Ke
Abstract
Abstract Mixed tin–lead (Sn–Pb) perovskites often face a daunting challenge: rapid and uncontrollable crystallization, leading to a plethora of defects and significant stress. This issue is particularly exacerbated during the blade‐coating preparation of scalable Sn–Pb perovskite films. In this study, a facile strategy involving the addition of ammonium citrate (AC) to narrow‐bandgap mixed Sn–Pb perovskite precursors is introduced. AC, armed with its arsenal of multiple carboxyl and amino groups, acts as a virtuoso conductor, orchestrating controlled crystal growth by harmonizing with Pb 2+ and Sn 2+ ions. This addition significantly boosts the crystallinity of the perovskite films, alleviates interface stress, inhibits Sn 2+ oxidation, and mitigates interfacial defects. Consequently, The blade‐coated AC‐incorporated mixed Sn–Pb perovskite solar cells achieve a high photovoltaic conversion efficiency of nearly 21%. Furthermore, extending this strategy to two‐terminal all‐perovskite tandem solar cells yielded a remarkable maximum efficiency of 27.20%. This work presents an effective strategy for producing efficient blade‐coated mixed Sn–Pb perovskite solar cells, heralding a pathway toward scalable fabrication of all‐perovskite tandem solar cells.