Addressing Toxicity of Lead: Progress and Applications of Low‐Toxic Metal Halide Perovskites and Their Derivatives

Metal halide perovskites have been brought to the forefront of research focus in solution‐processable photovoltaics, with the device efficiency swiftly surging to over 22% over the past few years. The state‐of‐the‐art metal halide perovskites that have been intensively investigated include toxic lead, which potentially hampers their commercialization process. To address this toxicity issue, intensive recent research effort has been devoted to developing low‐toxic metal halide perovskites and their derivatives for photovoltaic applications. Herein, the recent research progress achieved so far in addressing the toxicity issue of lead halide perovskites in photovoltaics is summarized. By comparing the merits and drawbacks of different low‐toxic metal halide systems, the current challenges and opportunities in the photovoltaic field are highlighted. Potential low‐toxic metal halide perovskites and their derivatives are also discussed from the perspective of theoretical calculations. Furthermore, promising applications of low‐toxic metal halide perovskites beyond the photovoltaic sector are briefly discussed.