Improved Performance of Perovskite Deep-Ultraviolet Photodetector Using FAPb(I/Br)3 as Light Absorption Layer

Constitutive engineering by adding halide anions is one effective way to improve the performance of photodetectors by adjusting the bandgap. In this study, a mixed-anion perovskite thin film was facile fabricated by post-processing of a pure FAPbI3 film with a formamidinium bromide (FABr) solution. In addition, the manufactured thin film was used as the light absorption layer, SnO2-SDBS as the electron transport layer, and spiro-OMeTAD as the hole injection layer to fabricate a deep ultraviolet(UV) photodetector. The device exhibited a response of 43.8 mA/W−1, a detectability of 3.56 × 1013 Jones, and an external quantum efficiency of 38%. Therefore, this study is promising for various applications in the deep-UV wavelength region.