Recent Progress and Challenges of Bismuth‐Based Halide Perovskites for Emerging Optoelectronic Applications

Abstract Recently, metal halide perovskites have attracted extensive attentions owing to their superior optoelectronic properties in various device applications, such as solar cells, photodetectors, light‐emitting diodes, lasing, photocatalysis, etc. Up to now, the state‐of‐the‐art developments of perovskite‐based devices are most using the lead‐halide perovskite system. However, the presence of lead (Pb) in these devices, which is insidious bioaccumulative hazard to human bodies, and a poor stability against light, heat, and humidity hamper their practical applications and future commercialization. Therefore, the scientific community is searching for low‐toxicity and environmental‐friendly lead‐free perovskite‐type materials as a back‐up strategy. Among the possible Pb‐substitution strategies, the trivalent bismuth cation (Bi³⁺) possesses the same electronic configuration as Pb²⁺, and some emerging Bi‐based perovskites and derivatives are experimentally characterized, which exhibit comparable optoelectronic properties to the Pb‐based perovskites. In this review, a comprehensive overview of currently explored Bi‐based halide perovskites is reported, with an emphasis on their synthesis methods, structural diversity, photophysical properties, and their current and potential applications in various optoelectronic categories. Finally, this review is finished with a critical outlook into the current challenges and development prospects of Bi‐based halide perovskites toward the versatile optoelectronic applications.