Stability of Sn-Pb mixed organic-inorganic halide perovskite solar cells: Progress, challenges, and perspectives

The exploration of low bandgap perovskite material to approach Shockley-Queisser limit of photovoltaic device is of great significance, but it is still challenging. During the past few years, tin-lead (Sn-Pb) mixed perovskites with low bandgaps have been rapidly developed, and their single junction solar cells have reached power conversion efficiency (PCE) over 21%, which also makes them ideal candidate as low band gap sub-cell for tandem device. Nevertheless, due to the incorporation of unstable Sn2+, the stability issue becomes the vital problem for the further development of Sn-Pb mixed perovskite solar cells (PSCs). In this review, we are dedicated to give a full view in current understanding on the stability issue of SnPb mixed perovskites and their PSCs. We begin with the demonstration on the origin of instability of Sn-Pb mixed perovskites, including oxidation of Sn2+, defects, and interfacial layer induced instability. Sequentially, the up-to-date developments on the stability improvement of Sn-Pb mixed perovskites and their PSCs is systematically reviewed, including composition engineering, additive engineering, and interfacial engineering. At last, the current challenges and future perspectives on the stability study of Sn-Pb mixed PSCs are discussed, which we hope could promote the further application of Sn-Pb mixed perovskites towards commercialization. (C) 2021 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by ELSEVIER B.V. and Science Press. All rights reserved.

Automated summary

The development of low bandgap tin-lead (Sn-Pb) mixed perovskite materials with high power conversion efficiency for solar cells faces challenges due to the instability issue of Sn2+ incorporation. Research into stability improvement through composition, additive, and interfacial engineering is ongoing to promote commercial applications of Sn-Pb mixed perovskites.