Photodetectors convert optical signals into electrical signals and demonstrate application potential in various fields, such as optical communication, image detection, environmental monitoring, and optoelectronics. In this study, a mixed cation–halide perovskite-based ultraviolet C photodetector was fabricated using a solution process. The higher the mobility of the perovskite carrier, which is one of the factors affecting the performance of electronic power devices, the better the carrier diffusion. The on/off ratio and responsivity indicate the sensitivity of the response, and together with the detectivity and external quantum efficiency, these parameters demonstrate the performance of the detector. The detector fabricated in this study exhibited a mobility of 202.2 cm2/Vs and a high on/off ratio of 105% at a −2 V bias, under 254 nm light irradiation with an intensity of 0.6 mW/cm2. The responsivity, detectivity, and external quantum efficiency of the as-fabricated detector were 5.07 mA/W, 5.49 × 1011 Jones, and 24.8%, respectively. These findings demonstrate that the solution process employed in this study is suitable for the fabrication of mixed cation–halide perovskites which show immense potential for use as photodetectors.

No abstract

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 FAPbCl3-MAPbCl3-based photodetector showed a high responsivity of 5.64 mA/W, a detectivity of 4.03 × 1011, and an external quantum efficiency of 27.3%. The results suggested that the FAPbCl3-MAPbCl3 perovskite is suitable for deep-UV light sensing and is an excellent candidate for the fabrication of a sensitive photodetector.