Defect passivation of a perovskite film by ZnIn 2 S 4 nanosheets for efficient and stable perovskite solar cells.

The defects of a perovskite film were first passivated by two dimensional ZnIn 2 S 4 nanosheets, the non-radiation recombination at interfaces was suppressed and the contact of the perovskite film with water vapour in the air was avoided, resulting in a high efficiency of 20.55%.