BiI₃修饰Cs₃Bi₂I₉自供能光电化学型探测器制备及其性能

Based on the synthesis of Cs₃Bi₂I₉ precursor solution by using solution method， Cs₃Bi₂I₉/BiI₃ thin films were obtained by adding BiI₃ to modify Cs₃Bi₂I₉ solution， and the Cs₃Bi₂I₉/BiI₃ photodetectors based on the device types of photoelectrochemical detectors with self-powered properties were also constructed. It is found that the added BiI₃ exists in the form of the second phase， forming a two-phase mixed structure. Under illumination of ultraviolet（365 nm） monochromatic light， Cs₃Bi₂I₉/BiI₃ photodetectors show on-off ratio of 3 198， corresponding to a response of 2.85×10^-3 A/W and a detectivity of 3.77×10¹⁰ Jones. While under illumination of green light（530 nm）， the device also exhibits on-off ratio of 1 172， a response of 6.9×10^-4 A/W and a detectivity of 1.76×10¹⁰ Jones. Compared with simple Cs₃Bi₂I₉ photodetectors， the detection performance of Cs₃Bi₂I₉/BiI₃ photodetectors has been greatly improved， which is attributed to the passivation of BiI₃ on non-radiation defects. It is the first time to apply Cs₃Bi₂I₉ in the photoelectrochemical structure detector. The modification of BiI₃ successfully improves the device performance， which provides a new idea for improving the performance of low-toxic bismuth-based perovskite photodetection application.