High-performance perovskite photodetectors based on CH <sub>3</sub> NH <sub>3</sub> PbBr <sub>3</sub> quantum dot/TiO <sub>2</sub> heterojunction
Rajeev Ray, Nagaraju Nakka, Suman Kalyan Pal
Abstract
Abstract Organo-lead halide perovskite materials have opened up a great opportunity to develop high performance photodetectors because of their superior optoelectronic properties. The main issue with perovskite-only photodetector is severe carrier recombination. Integration of perovskite with high-conductive materials such as graphene or transition metal sulfides certainly improved the photoresponsivity. However, achieving high overall performance remains a challenge. Here, an improved photodetector is constructed by perovskite quantum dots (QDs) and atomic layer deposited ultrathin TiO 2 films. The designed CH 3 NH 3 PbBr 3 QD/TiO 2 bilayer device displays inclusive performance with on/off ratio of 6.3 × 10 2 , responsivity of 85 A W −1 , and rise/decay time of 0.09/0.11 s. Furthermore, we demonstrate that interface plays a crucial role in determining the device current and enhance the overall performance of heterostructure photodetector through interface engineering. We believe that this work can provide a strategy to accelerate development of high-performance solution-processed perovskite photodetectors.