Tin–lead halide perovskites with improved thermal and air stability for efficient all-perovskite tandem solar cells

We report the fabrication of monolithic all-perovskite tandem solar cells with a stabilized power conversion efficiency of 19.1% and demonstrate improved thermal, atmospheric, and operational stability of the tin–lead perovskite (FA_0.75Cs_0.25Sn_0.5Pb_0.5I₃) used as the low gap absorber.