Enhanced Performance of All-Inorganic Lead Halide Perovskite/MoS₂ Heterojunction Photodetectors by Achieving Interfacial Carrier Separation

A heterojunction interface engineering aimed at improving the performance of all-inorganic lead halide perovskite photodetectors (PDs) is demonstrated by coupling the two-dimensional (2D) MoS2 materials with CsPbBr3 used in the chemical vapor deposition method in situ-grown. The MoS2 carrier extraction layer facilitates electron injection, while the large injection barrier of the CsPbBr3/MoS2 heterojunction depletion layer keeps holes in the perovskite layer, resulting in effective separation of photogenerated carriers at the heterojunction interface. Moreover, the photoluminescence quenching and lifetime shortening of the heterojunction further prove that there is a large amount of charge transfer between the CsPbBr3 and MoS2 interface. As a result, PDs based on the CsPbBr3/MoS2/interdigitated array electrodes (IDA) heterojunction exhibit remarkable performance, such as high photoresponsivity (23.4 A W-1), detectivity (1.48 x 10(13) Jones), and switching ratio (1.35 x 10(5)), all of which are an order of magnitude better than pure CsPbBr3 PDs. The heterojunction PD also presents a superior response time (0.07 ms).