▎ 摘 要
The electronic properties of graphene supported by the (0001) SiO2 surface are theoretically studied using density functional theory. It is found that the electronic attributes of graphene on (0001) SiO2 strongly depend on the underlying SiO2 surface properties and the percentage of hydrogen passivation. By applying methyl to passivate the oxygen-terminated (0001) SiO2 surface, one can further reduce the interaction between the graphene sheet and oxygen-terminated surface. This can improve the charge carrier mobility of graphene supported by SiO2 substrate and reduce the influence of residues of interfacial molecules. In addition, the external electric field modulates the charge transfer between graphene and the SiO2 surface when graphene layers are physisorbed on the oxide surface. This phenomenon will enhance the built-in electric field of bilayer graphene so as to effectively modify its band structure. Our results shed light on a better atomistic understanding of the recent experiments on graphene supported by SiO2.