Self-Powered and Broadband Lead-Free Inorganic Perovskite Photodetector with High Stability.

Metal halide perovskite materials have opened up a great opportunity for high-performance optoelectronic devices owing to their extraordinary optoelectronic properties. More than lead halide ones, stable and nontoxic bismuth halide perovskites exhibit more promise in their future commercialization. In this work, we developed for the first time photodetectors based on full-inorganic Cs3Bi2I9-xBrx perovskites and modulate their performance by varying x in the composition systematically. Among those self-powered photodetectors, those based on Cs3Bi2I6Br3 shows the best performance with excellent photosensitivity of 4.1 × 104 at zero bias as well as the responsivity and detectivity reaching 15 mA/W and 4.6 × 1011 Jones, respectively. More strikingly, the full-inorganic perovskite photodetectors exhibit excellent stability in the ambient environment and can maintain over 96% of the initial value after 100 days owing to the high stability of the core perovskite film. The paper definitely paves an alternative and promising strategy for the design of future commercial photodetectors that are self-powered, stable, nontoxic, etc.