Self-powered photodetectors based on 0D/2D mixed dimensional heterojunction with black phosphorus quantum dots as hole accepters

Two-dimensional (2D) materials exhibit outstanding performance and good application prospects in the field of photodetectors due to their excellent optical and electronic properties. However, weak light absorption capacity the rapid recombination of photogenerated electron-hole pairs is still a serious obstacle that limits their light detection performance. Black phosphorus (BP) can act as a hole acceptor due to its excellent hole mobility, which can induce the rapid transfer of photogenerated holes, and the heterojunction at the interface promotes the injection of photogenerated electrons onto the surface of MoS2, thereby effectively promoting the separation of photogenerated electron-hole pairs. In addition, recent reports indicate that quantum dots (QDs) have excellent local photon capture capabilities due to their quantum confinement and surface effects, which are considered to be excellent light absorbers that enhance the performance of photodetectors in 2D materials. Here, we prepared black phosphorus QDs-molybdenum disulfide (BP QDs-MoS2) heterojunction and constructed a photo-electrochemical-type (PEC-type) photodetector based on the heterojunction. Experimental results show that the BP QDs-MoS2 heterojunctionbased PEC-type photodetector exhibits significantly enhanced photo-response performance. Meanwhile, the PEC-type photodetector also exhibits self-powered photo-response behavior, good photoresponse performance and stability in a liquid environmentand. This work strongly proves that BP QDs are used as hole acceptors to promote the separation of photogenerated electron-hole pairs is an effective means. (C) 2020 Elsevier Ltd. All rights reserved.