Interaction between graphene and the surface of SiO2

The interaction between graphene and a SiO2 surface has been analyzed with first-principles DFT calculations by constructing the different configurations based on α-quartz and cristobalite structures. The fact that single-layer graphene can stay stably on a SiO2 surface is explained based on a general consideration of the configuration structures of the SiO2 surface. It is found that the oxygen defect in a SiO2 surface can shift the Fermi level of graphene down which opens up the mechanism of the hole-doping effect of graphene adsorbed on a SiO2 surface observed in a lot of experiments.