A review on the current status and chemistry of tin halide perovskite films for photovoltaics

Tin halide perovskites are seen as the leading lead-free metal halide perovskite due to the high degree of similarity with the conventional lead-based materials. However, the chemistry of tin halide perovskites is distinct from that of lead halide perovskites, resulting in a material that is challenging to produce at a sufficient quality that enables high performing photovoltaic cells. This review seeks to summarise and discuss the existing literature on tin halide perovskites and photovoltaic devices that utilise them. The first section of this review will summarise the progress that has been made in the field of tin halide perovskite photovoltaics, and then in detail discuss various aspects of tin halide perovskites, including their basic semiconducting properties, defect physics, crystallinity, and degradation mechanisms, along with the strategies that have been employed to control these aspects and potential theoretical options that yet to have been explored. Future research directions for tin halide perovskite will include finding new additives for regulating; 1) the growth rate, 2) the defect densities, and 3) the stability of tin halide perovskites.