Enhanced ambient-stability and charge transport property of the CsPbBr3@Polyaniline

Abstract

Although all-inorganic lead halide perovskites (CsPbX3 (X = Cl, Br, I)) have received widespread attention due to excellent optoelectronic properties, their low carrier mobility and poor stability have limited their application in photodetection. In this study, to alleviate these problems, CsPbBr3@Polyaniline composite is fabricated by passivating CsPbBr3 quantum dots (QDs) into a CSA-doped polyaniline conducting polymer. Notably, polyaniline is employed as a protective layer to block the structure damage of CsPbBr3 QDs against water, light and heat. The contact between polyaniline and CsPbBr3 QDs forms a type II heterojunction for charge transfer, which greatly reduces the recombination rate of charge carriers compared to pristine CsPbBr3 QDs. Benefiting from the high stability and enhanced charge mobility, CsPbBr3@Polyaniline-based photodetector achieves improved photocurrent signal and optical response time. The results demonstrate that the surface passivation could resolve the crucial stability problem and simultaneously facilitate the superior performance of perovskite optoelectronic devices.