Electronic decoupling of an epitaxial graphene monolayer by gold intercalation

The application of graphene in electronic devices requires large-scale epitaxial growth. The presence of the substrate, however, usually reduces the charge-carrier mobility considerably. We show that it is possible to decouple the partially $s{p}^{3}$-hybridized first graphitic layer formed on the Si-terminated face of silicon carbide from the substrate by gold intercalation, leading to a completely $s{p}^{2}$-hybridized graphene layer with improved electronic properties.