▎ 摘　　要

We report on direct observation of interface superconductivity in single-unit-cell SnSe2 films grown on graphitized SiC(0001) substrate. The tunneling spectrum in the superconducting state reveals a rather conventional character with a fully gapped order parameter. The occurrence of superconductivity is further confirmed by the observation of vortices under external magnetic field. Through interface engineering, we unravel the mechanism of superconductivity that originates from a two-dimensional electron gas formed at the interface of SnSe2 and graphene. Our finding opens up novel strategies to hunt for and understand interface superconductivity based on van der Waals heterostructures.