Modulating the stability and photoresponse of methylammonium tin iodide perovskite enabled by polymer assist crystallization

Lead-based perovskites, despite their excellent optoelectronic properties, pose environmental hazards because of the toxicity of lead. Efforts are being made to replace lead with non-toxic elements, such as tin. However, tin-based perovskites exhibit lower stability under ambient conditions because of the oxidation of tin, leading to a change in the material properties with the degradation of the perovskite film. This work explores the use of polyvinylidene fluoride (PVDF) as an additive to enhance the stability and photoresponse of methylammonium tin iodide perovskite based devices. The additive used is compared with the conventionally used tin fluoride (SnF2) additive, to examine its role in tin-based perovskites. The incorporation of PVDF in perovskite helps understand the process of crystallization and stability, by utilizing different characterization techniques. It improves film uniformity, reduces trap states, and enhances photoresponse by providing a stable matrix for methylammonium tin iodide perovskites.