Fabrication and characterization of few-layer Tungsten Disulfide (WS2) field effect transistors

Owing to the direct bandgap and high mobility, two-dimensional semiconductor materials have stimulated a lot interest. However, the contact between the TDMs and metal remains far from optimized which are highly resistive. Here, we report a study on the WS₂ field effect transistor fabrication and characterization concentrating on the investigation of metal contact. The WS₂ is obtained by mechanical exfoliation and fabricated into devices by E-beam evaporation. The preliminary result shows low mobility due to the work function mismatch. Nevertheless, this report gives a generic strategy to improve device performance for WS2 and further investigation is discussed and still ongoing.