Morphology of Graphene on Step-Controlled Sapphire Surfaces

Graphene attached on a sapphire surface with regularly ordered step-terrace structure was observed using atomic force microscopy (AFM). We found that graphene tightly adheres to a sapphire surface and the buried step structure on the sapphire surface was clearly observed on the graphene surface. Height of a single-layer graphene was estimated to be approximately 0.36 nm on sapphire surface, which is in good agreement with the theoretical height. These results indicate that sapphire is suitable for the substrate that supports graphene because we can obtain undistorted graphene that is tightly fixed on a substrate surface. (C) 2009 The Japan Society of Applied Physics