Mechanochemical Synthesis of Sn(II) and Sn(IV) Iodide Perovskites and Study of Their Structural, Chemical, Thermal, Optical and Electrical Properties

Phase‐pure CsSnI3, FASnI3, Cs(PbSn)I3, FA(PbSn)I3 perovskites (FA = formamidinium = HC(NH2)2+) as well as the analogous so‐called vacancy‐ordered double perovskites Cs2SnI6 and FA2SnI6 are mechanochemically synthesized. The addition of SnF2 is found to be crucial for the synthesis of Cs‐containing perovskites but unnecessary for hybrid ones. All compounds show an absorption onset in the near‐infrared (NIR) region, which makes them especially relevant for photovoltaic applications. The addition of Pb(II) and SnF2 is crucial to improve the electronic properties in 3D Sn(II)‐based perovskites, in particular their charge carriers mobility (≈0.2 cm2 Vs−1) which is enhanced upon reduction of the …