Incorporation of γ-aminobutyric acid and cesium cations to formamidinium lead halide perovskites for highly efficient solar cells

• Published in: Journal of energy chemistry 2022-01, Vol.64, p.561-567
• Main Authors: Hu, Yanqiang, Shan, Yansu, Yu, Zhaolei, Sui, Haojie, Qiu, Ting, Zhang, Shufang, Ruan, Wei, Xu, Qinfeng, Jiao, Mengmeng, Wang, Dehua, Wu, Yunyi, Yang, Chuanlu, Xu, Feng
• Format: Article
• Language: English
• Subjects: Methylammonium-free; Perovskite solar cells; Stability; γ-aminobutyric acid
• ISSN: 2095-4956
• DOI: 10.1016/j.jechem.2021.05.025

[Display omitted] The partially substituting of A-site FA+ by GABA+ and Cs+ cations into FAPbI3 perovskites greatly improved the phase stability and photovoltaic performance. •GABA+ and Cs+ cations were introduced into FA-based perovskite to improve its phase stability.•A champion efficiency up to 23.71% was achieved for the optimized PSCs.•The optimal PSCs showed excellent stability under illumination. The stability issue has become one of the main challenges for the commercialization of perovskite solar cells (PSCs). Formamidinium (FA)-based perovskites have shown great promise owing to their improved thermal and moisture stability. However, these perovskites are suffering from phase transition and separation. Here, a method of incorporating of γ-aminobutyric acid (GABA) and cesium cations into FAPbI3 is developed to improve the phase stability. It is demonstrated that the crystallinity of α-FAPbI3 phase is greatly improved and the phase transition temperature is significantly dropped. The resultant solar cell therefore obtains a champion power conversion efficiency (PCE) of 23.71%, which is one of the highest efficiencies for methylammonium-free PSCs. Furthermore, it shows an impressively enhanced stability under illumination, exhibiting the great potential of FA-based perovskites for efficient and stable solar cells.