Realization of free-standing silicene using bilayer graphene

Abstract

The available synthesized silicene-like structures have been only realized on metallic substrates which are very different from the standalone buckled silicene, e.g. the Dirac cone of silicene is destroyed due to lattice distortion and the interaction with the substrate. Using graphene bilayer as a scaffold a novel route is proposed to synthesize silicene with electronic properties decoupled from the substrate. The buckled hexagonal arrangement of silicene between the graphene layers is found to be very similar to the theoretically predicted standalone buckled silicene which is only very weakly van der Waals coupled to the graphene layers with a graphite-like interlayer distance of 3.42\,\AA and without only lattice distortion. We found that these stacked layers are stable well above room temperature.