Selective grain boundary passivation by ammonium nitrate for enhanced performance and stability of FA-Cs based perovskite solar cells

Grain boundaries of metal halide perovskites contain massive defects that are detrimental to photovoltaics applications. This work demonstrates that inorganic NH4NO3 can selectively passivate the grain boundaries of perovskite films and improve their moisture resistance simultaneously, resulting in enhanced performance and stability of the methylammonium-free perovskite solar cells. Ammonium nitrate can be used for selective grain boundary passivation of FA-Cs based perovskite thin films and solar cells.