▎ 摘　　要

Graphene and transition metal dichalcogenides (TMDCs), an emerging class of two-dimensional (2D) materials exhibiting excellent electrical and optical properties have shown a phenomenal advancement in optoelectronics and electronic technology. However, two-dimensional van der Waals heterostructures have gained profound interest due to additional functionalities over usual 2D devices. Here we demonstrated the photoconductive response of graphene-WS2 heterostructure at different backgate (V-g) and drain-source voltages (V-ds) as a function of time, under UV illumination. An increase in photocurrent characteristics is observed as V-ds varies from 0.3 V to 1 V. The response of photosensivity is tuned by varying the backgate voltage. The optical performance of graphene-WS2 phototransistor is evaluated by investigating the photoresponsivity (R-lambda), detectivity (D*), external quantum efficiency (EQE) and linear dynamic range (LDR). These results suggest the TMDC-graphene heterostructure, as a good contender to be used in photosensing and optoelectronic applications. (C) 2017 Elsevier B.V. All rights reserved.