Top-gated WSe 2 field-effect transistors with Pt contacts

Tungsten diselenide (WSe 2 ) is a transition metal dichalcogenide (TMD) that is being explored as an alternative channel material for p-type field-effect transistors (FETs). To date, making low resistance contacts to WSe 2 has employed techniques like ionic-liquid gating [1], or surface charge-transfer doping [2], which are unscalable, and unstable in air. Here, we demonstrate top-gated, few-layered WSe 2 p-FETs enabled by Ohmic platinum (Pt) contacts, and a hexagonal boron nitride (hBN) gate-dielectric, with ON/OFF ratios > 10 7 , and intrinsic hole mobilities ∼ 100 cm 2 /Vs at 300 K, and up to 2,000 cm 2 /Vs at 2 K.