CH3NH3SnxPb1-xBr3 hybrid perovskite solid solution: synthesis, structure, and optical properties.

We report the synthesis and characterization of a MASnxPb1-xBr3 (MA = methylammonium; nominal x = 0, 0.2, 0.4, 0.5, 0.6, 0.8, 1) solid solution. The original synthetic method developed allowed one to obtain single-phase materials with homogeneous Sn/Pb distribution. All of the samples prepared are cubic, and the unit cell linearly decreases with increasing x value. The optical response indicates a linear trend (Vegard's law) of the band gap with increasing Sn content from 2.20 eV (x = 0) to 1.33 eV (x = 1), thus extending light absorption into the near-IR.