Lead‐Free Perovskite Photodetectors: Progress, Challenges, and Opportunities

Abstract State‐of‐the‐art photodetectors which apply hybrid perovskite materials have emerged as powerful candidates for next‐generation light sensing. Among them, lead‐based ones are the most popular beyond doubt on account of their unique and superior optoelectronic properties. Nevertheless, trade‐off toward commercialization exists between nontoxicity and high performance, with the poor stability of lead‐based perovskites, indicating that it is indispensable to substitute lead with nontoxic element meanwhile bringing about a comparable figure of merit of photodetectors and relatively long‐term stability. Herein, recent advances in lead‐free perovskite photodetectors are reviewed, analyzing the principle while designing new materials and highlighting some remarkable progress, which are comparable, even superior, to lead‐based photodetectors. Furthermore, their potential strategy in optical communication, image sensing, narrowband photodetection, etc., is examined and a perspective on developing new materials and photodetectors with superior properties for more practical applications is provided.