Prospects for Tin-Containing Halide Perovskite Photovoltaics

Tin-containing metal halide perovskites have enormous potential as photovoltaics,both in narrow band gap mixed tin−lead materials for all-perovskite tandems and for lead-free perovskites.The introduction of Sn(II),however,has significant effects on the solution chemistry,crystallization,defect states,and other material properties in halide perovskites.In this perspective,we summarize the main hurdles for tin-containing perovskites and highlight successful attempts made by the community to overcome them.We discuss important research directions for the development of these materials and propose some approaches to achieve a unified understanding of Sn incorporation.We particularly focus on the discussion of charge carrier dynamics and nonradiative losses at the interfaces between perovskite and charge extraction layers in p-i-n cells.We hope these insights will aid the community to accelerate the development of high-performance,stable single-junction tincontaining perovskite solar cells and all-perovskite tandems.