Enhancing Perovskite Solar Cell Performance through Femtosecond Laser Polishing.

Nonradiative recombination loss is a key process that determines the performance of perovskite solar cells, and how to control it is significant for the research and development of perovskites. Generally, traditional chemical modification/passivation methods are complicated and prone to secondary contamination. Herein, femtosecond (fs) laser polishing as a promising technique is demonstrated to ameliorate the surface of perovskite films, reduce nonradiative recombination loss, and improve solar cell performance. The high‐intensity fs laser pulses can remove around 20 nm‐thick perovskite top layer through an ionization process, help to decrease the grain boundary density, and enlarge the grain size of perovskite films after recrystallization. It is believed that fs laser polishing is a time‐effective and highly precise technique that is suitable for large‐scale device production, thus will trigger more applications in optoelectronics. [ABSTRACT FROM AUTHOR]