Sputtering and Electron Beam Irradiation of WS2/MoS2 and MoS2/WS2 Heterostructures for Enhanced Photoresponsivity

In the present study, we proposed heterostructures of MoS2 and WS2 formed by radio frequency (RF) magnetron sputtering and electron beam irradiation (EBI) for obtaining enhanced photoresponsivity. Each amorphous transition metal dichalcogenide (TMD) was sequentially deposited and EBI was performed on the as-deposited TMD heterostructures. After EBI, the atomic rearrangement of the heterostructures was studied. Moreover, the depth profile of the synthesized heterostructures was investigated using angle-resolved X-ray photoelectron spectroscopy (AR-XPS). We achieved a photoresponsivity of 5.1 A/W in EBI-treated TMD heterostructures, which was further enhanced by three orders as compared with that obtained in EBI-treated TMD single structures.