Halide perovskites have emerged at the forefront of semiconductor materials for photovoltaic and light-emitting devices. However, long-term stability and toxicity are the major barriers to their commercialization. In particular, the toxicity of lead (Pb) and its environmental impact have prompted the exploration of lead-free alternatives like tin (Sn) and bismuth (Bi). Herein, a cytotoxicity study of Pb-based perovskite (CsPbBr