Study on a Mixed-Cation Halide Perovskite-Based Deep-Ultraviolet Photodetector

Deep-ultraviolet (UV) sensing has attracted significant interest because of its wide range of applications. A mixed-cation halide perovskite-based photodetector prepared by mixing CH3NH3PbX3 (X = I, Br, and Cl) and HC(NH2)PbX3 (X = I, Br, and Cl) exhibits high stability and excellent light absorption. In this study, perovskite was prepared by mixing CH3NH3+ (FA(+)) and HC(NH2)(2)(+) (MA(+)) cations using I-, Br-, and Cl- halide anions. The bandgaps of the prepared perovskites increased to 1.48, 2.25, and 2.90 eV with I-, Br-, and Cl-, respectively, and the light absorption spectra shifted to shorter wavelengths. An increase in the redshift of the light absorption led to an increase in the photocurrent. The FAPbCl(3)-MAPbCl(3)-based photodetector showed a high responsivity of 5.64 mA/W, a detectivity of 4.03 x 10(11), and an external quantum efficiency of 27.3%. The results suggested that the FAPbCl(3)-MAPbCl(3) perovskite is suitable for deep-UV light sensing and is an excellent candidate for the fabrication of a sensitive photodetector.