2D MoS2/CuPc heterojunction based highly sensitive photodetectors through ultrafast charge transfer. (December 2020) - Xu, Z.H
Abstract: Photodetectors (PD) with high detectivity, high quantum efficiency and fast response are fundamental units to achieve sensors, imagers, and many others functional optoelectronics. Here we demonstrate high performance vertical stacked 2D MoS2 /CuPc heterojunction based photodetectors with high sensitivity, high external quantum efficiency and ultrafast response time. The functional p-type organic thin film of CuPc was thermally evaporated on n-type two-dimension (2D) MoS2 monolayer to create an ideal type II heterojunction interface, where ultrafast charge transfer (CT) occur in 16 ps, followed by effective exciton separation and charge collection. As a result, photoresponse time as fast as 436 μs has been obtained for 2D MoS2 /CuPc PDs, as well as a profound responsivity of 3.0 × 10 3 A/W and a detectivity of 2.0 × 10 10 Jones with a peak external quantum efficiency ( EQE ) of 483%. This work suggests a feasible route to develop ultrasensitive visible light photodetector by 2D materials. Graphical abstract: The functional p-type CuPc was stacked on n-type two-dimension (2D) MoS2 monolayer to create an ideal pn heterojunction interface, where ultrafast charge transfer (CT) occurs in 16 ps. Photoresponse time as fast as 436 μs has been obtained for 2D MoS2 /CuPc photodetectors. Image 1 Highlights: The 2D MoS2 monolayer is explored to form a heterojunction with an organic layer of CuPc. Ultrafast charge transfer occurs at the 2D MoS2 /CuPc interface for efficient exciton separation. The 2D MoS2 /CuPc photodetectors have high sensitivity and ultrafast response speed.