FAPb_(0.5)Sn_(0.5)I_3: A Narrow Bandgap Perovskite Synthesized through Evaporation Methods for Solar Cell Applications

摘要

The tunability of the optoelectrical properties upon compositional modification isa key characteristic of metal halide perovskites. In particular, bandgaps narrowerthan those in conventional lead-based perovskites are essential to achieve thetheoretical efficiency limit of single-absorber solar cells, as well as developmultijunction tandem devices. Herein, the solvent-free vacuum deposition of anarrow bandgap perovskite based on tin–lead metal and formamidinium cation isreported. Pinhole-free films with 1.28 eV bandgap are obtained by thermalcodeposition of precursors. The optoelectrical quality of these films is demonstratedby their use in solar cells with a power conversion efficiency of 13.98%.