Recovery of the Dirac states of graphene by intercalating two-dimensional traditional semiconductors.

The epitaxial growth of graphene on transition-metal substrates has proved to be an efficient method to synthesize high-quality large-area graphene. However, due to the interaction between graphene and the transition-metal substrate, the electronic structure of the as-fabricated graphene is distorted. Here, using density functional theory calculations, we investigated the effect of intercalating two-dimensional (2D) silicon and III-V materials, such as double-layer honeycomb AlAs, into the graphene-metal interface. We found that the intercalation of these 2D materials significantly reduces the interaction between graphene and the transition-metal substrate. The Dirac state is largely restored. The doping level of graphene induced by 2D intercalated material and the metal substrate is proportional to the work function difference between graphene and 2D materials/metal. This work provides a way for the formation of freestanding graphene and further fabrication of graphene-based devices.