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Stable and High‐Efficiency Methylammonium‐Free Perovskite Solar Cells
Author(s) -
Gao XiaoXin,
Luo Wen,
Zhang Yi,
Hu Ruiyuan,
Zhang Bao,
Züttel Andreas,
Feng Yaqing,
Nazeeruddin Mohammad Khaja
Publication year - 2020
Publication title -
advanced materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 10.707
H-Index - 527
eISSN - 1521-4095
pISSN - 0935-9648
DOI - 10.1002/adma.201905502
Subject(s) - perovskite (structure) , formamidinium , materials science , energy conversion efficiency , halide , perovskite solar cell , band gap , degradation (telecommunications) , phase (matter) , chemical engineering , optoelectronics , inorganic chemistry , organic chemistry , chemistry , electronic engineering , engineering
Organic–inorganic metal halide perovskite solar cells (PSCs) have achieved certified power conversion efficiency (PCE) of 25.2% with complex compositional and bandgap engineering. However, the thermal instability of methylammonium (MA) cation can cause the degradation of the perovskite film, remaining a risk for the long‐term stability of the devices. Herein, a unique method is demonstrated to fabricate highly phase‐stable perovskite film without MA by introducing cesium chloride (CsCl) in the double cation (Cs, formamidinium) perovskite precursor. Moreover, due to the suboptimal bandgap of bromide (Br − ), the amount of Br − is regulated, leading to high power conversion efficiency. As a result, MA‐free perovskite solar cells achieve remarkable long‐term stability and a PCE of 20.50%, which is one of the best results for MA‐free PSCs. Moreover, the unencapsulated device retains about 80% of the original efficiencies after a 1000 h aging study. These results provide a feasible approach to enhance solar cell stability and performance simultaneously, paving the way for commercializing PSCs.