Improved charge extraction and atmospheric stability of all-inorganic Cs2AgBiBr6 perovskite solar cells by MoS2 nanoflakes

Among lead-free halide double perovskites , Cs 2 AgBiBr 6 is a potential alternative to substitute toxic and unstable organic-inorganic lead-based halide perovskites. However, the film forming ability and wide indirect bandgap have impeded its applications. Herein, we investigate to use MoS 2 nanoflakes as a hole transport interlayer to improve the crystallinity of Cs 2 AgBiBr 6 , tailor energy level alignments and enhance the stability of solar cells. With the addition of the MoS 2 nanoflakes, the Cs 2 AgBiBr 6 -based solar cell has a power conversion efficiency of 4.17% with an open circuit voltage of 1.10 V and short-circuit current of 6.12 mA cm −2 . This work would provide a new approach for developing all inorganic lead-free Cs 2 AgBiBr 6 -based solar cells with high power conversion efficiency and good stability.