Tin Halide Perovskites Going Forward: Frost Diagrams Offer Hints

• DOI: 10.1021/acsmaterialslett.0c00571
• Publication Date: 2021-02-18T04:33:23Z
• Authors: Muhammad Awais; Rebecca L. Kirsch; Vishal Yeddu; Makhsud I. Saidam...
• Keywords: Valence electron

Lead (Pb) in conventional perovskite solar cells (PSCs) is toxic and has to be replaced. Situated one group of the periodic table elements, tin (Sn) same valence electrons' configuration as Pb (ns2np2), promising analogous chemical properties. Hence, Sn considered a suitable replacement Pb. However, because lack lanthanide shrinkage, behaves differently: stable Pb2+ form, an oxidation state needed for structure, while tends lose all its electrons forming Sn4+. As result, PSCs based on are not efficient. Traces oxygen have been conventionally discussed source oxidation. But recent findings point Sn-based perovskites even absence oxygen. This perspective summarizes recently-discovered unconventional pathways perovskites, including reaction with solvent molecules disproportionation. We explain these phenomena by Frost–Ebsworth diagram argue that deeper understanding this key toward efficient Pb-free PSCs.