Compositional engineering of metal halide perovskite for photo-sensing applications

Abstract

Photodetectors convert light signals into electrical signals and are widely used in various applications like imaging, sensing and spectroscopy etc. Perovskites are widely used as an active layer in fabricating photodetectors because they show remarkable properties, such as low band gap, high light absorption coefficient, longer diffusion length, and higher carrier mobility. In addition to these properties, perovskite photodetectors have the advantage of simple and costeffective fabrication and high performance, making them a better candidate for photodetection applications. Among various types of CH3NH3PbI3 morphology (say single crystal, microwire etc.) CH3NH3PbI3 microwires are particularly more useful for photodetection because of their lower defect density and highert mechanical flexibility. In this work, we successfully synthesized a lateral structure CH3NH3PbI3 microwire photoconductor (ITO/ CH3NH3PbI3/ITO) under ambient conditions and showed their various figure of merit. Further, to increase the response of this photodetector we synthesized polymer treated (PVP) photodetector which enhanced current by 1.44 times. Now, the stability of perovskite is the biggest issue of this time, so to enhance the stability of perovskite, we deposited a layer of a polymer PMMA, which not only enhanced its stability but also enhanced its photocurrent as well as various response parameters. This work opens the way toward improving stability and enhancing various response parameters of MAPbI3 photodetector.