Monolayer Superconductivity in WS 2

Superconductivity in monolayer tungsten disulfide (2H‐WS 2 ) is achieved by strong electrostatic electron doping of an electric double‐layer transistor (EDLT). Single crystals of WS 2 are grown by a scalable method − chemical vapor deposition (CVD) on standard Si/SiO 2 substrate. The monolayers are identified by both AFM and color‐coding techniques. The EDLT device based on single‐layer WS 2 shows ambipolar transfer characteristics indicating a semiconducting nature of the material. Metallic transport on the electron side evolves into superconductivity with critical temperature T c  = 3.15 K.