On biosafety of Sn-containing halide perovskites†

Lead based halide perovskites have made great progress in various fields especially optoelectronic devices, but the health risk caused by heavy metal lead strongly blocks their widespread applications. Therefore, Pb free perovskites such as Sn based halide perovskites have been proposed and are expected to address the toxicity issue. However, until now, the toxicity and environmental impact of tin-based halide perovskites are still debated. This even raised a critical question about whether it is still worth deploying tin-containing halide perovskites which needs to be answered urgently but has so far remained elusive. In this work, we carefully analyse the practical application conditions of tin-based halide perovskites e.g., solar cells and conduct a comprehensive toxicity evaluation under these realistic situations. Our results including the organ weight index, blood analysis, immunohistochemistry (IHC) tests and next generation sequencing (RNA sequencing) demonstrated that even in the worst condition of large-scale applications of Sn based halide perovskites, neither obvious acute toxicity nor risk at a gene level can be observed. Thus, we conclude that Sn based halide perovskites are bio safe and substituting lead with tin in halide perovskites is applicable.