Construction of graphene/silicene heterostructure by Si intercalation*

The easy oxidation of silicene in air limits its applications in device design and fabrication. Here we report the experimental fabrication of silicene protected by a graphene overlayer. The graphene layer is grown first on a Ru(0001) substrate and silicene is grown under it by Si intercalation. By controlling the amount of silicon, ordered arrays of pseudomorphic silicene nano flakes as well as single layers and multilayers of silicene can be successfully fabricated under graphene that is epitaxially grown on Ru(0001). Density-functional-theory calculations show weak interactions between graphene and silicene layers, indicating that the fabricated structures are silicene/graphene van der Waals heterostructures. The as-prepared silicene-based structures show no observable damage after air exposure for two weeks.

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