Few-layer graphene on SiC, pyrolitic graphite, and graphene:: A Raman scattering study

The results of micro-Raman scattering measurements performed on three different "graphitic" materials: microstructured disks of highly oriented pyrolytic graphite, graphene multilayers thermally decomposed from carbon-terminated surface of 4H-SiC and an exfoliated graphene monolayer are presented. Despite its multilayer character, most parts of the surface of the graphitized SiC substrates shows a single component, Lorentzian shape, double resonance Raman feature in striking similarity to the case of a single graphene monolayer. Our observation suggests a very weak electronic coupling between graphitic layers on the SiC surface, which therefore can be considered to be graphene multilayers with a simple (Dirac-like) band structure. (c) 2008 American institute of Physics.