Boosting the stability and efficiency of Cs2AgBiBr6 perovskite solar cells via Zn doping

Cesium silver bismuth halides(Cs2AgBiBr6) perovskite solar cells(PSCs) exhibit low power conversion efficiency (PCE) due to their inherent defects. In this study, transition metal zinc(Zn) cation is firstly incorporated into Cs2AgBiBr6 perovskites to form Cs2(Ag1-xZnx)BiBr6, which significantly increases the efficiency of Cs2AgBiBr6-based perovskite solar cells by 45.9%, with an increase of 26.6% in short-circuit current density. Optoelectronic investigations demonstrate that the inclusion of Zn2+ (10%)suppresses charge recombination, enhances electron extraction at the interface of TiO2/perovskite, and reduces trap density. Moreover, the stability against long-term environment and heat stress is maintained to nearly 90% of the initial PCE after aging in ambient atmosphere. This work emphasizes a useful strategy to boost the PCE of lead-free Cs2AgBiBr6-based perovskite solar cells and provides a new route for preparing high-performance and stable all-inorganic perovskite solar cell.