A study on mixed cation perovskite-based UVC photodetector with improved performance

Abstract

Ultraviolet (UV) detectors are used in diverse areas of light detection and image analysis, such as astronomy, medicine, and environmental monitoring. Most of the UVC emitted from the sun is absorbed by ozone and does not reach the earth's surface; as a result, only a weak signal is detected. However, UVC is also produced by artificial sources and can have detrimental effects on health and materials. To measure UVC accurately it is desirable to develop a semiconductor UVC photodetector that converts an incident optical signal into an electrical signal for analysis. Recently, ultraviolet detectors based on the semiconductor characteristics of perovskite have attracted attention. Perovskite effectively absorbs a wide range of wavelengths and has high charge-carrier mobility. In this study, the (FAPbI(3))(x)(MAPbI(3))(1-x) mixed cation perovskite was used as the light-absorbing layer of a photodetector. The parameters investigated in this study are showing the performance of the photodetector, including the on/off ratio, responsivity, detectivity, and external quantum efficiency. (FAPbI(3))(0.925)(MAPbI(3))(0.075) film has a high on/off ratio of 877, a responsivity of 5.87 mA/W, a detectivity of 4.15 x 10(12), and an external quantum efficiency of 28.7%. These results suggest that perovskite prepared with mixed cations can be a promising candidate for UV C photodetector materials.