Si-intercalated graphene/SiC(0001) as studied by low energy electron diffraction and X-ray photoelectron spectroscopy

Abstract

The buffer layer of a 1 ML graphene/SiC(0001) sample grown by standard graphitization was decoupled by intercalating Si atoms between the SiC substrate and the $\left(6\sqrt{3}\times6\sqrt{3}\right)R30\degree$ buffer layer. Comparison of the LEED patterns and C1s XPS spectra of the as grown 1 ML graphene/SiC(0001) and the Si-intercalated sample showed a successful intercalation and decoupling of the buffer layer. This result was further confirmed by using the XPS attenuation equation to determine the number of graphene layers. It was found that the number of layers of the as grown 1 ML graphene before Si intercalation was increased to 2 ML after Si intercalation. This evidences the decoupling of the buffer layer from the SiC(0001) substrate resulting to an additional graphene layer.