| These rich novel properties of this peculiar two-dimensional nanomaterial come from its unparalleled sp2hybrid structure. On account of pure graphene has a zero band gap, which severely limits its application in the field effect transistor, this paper is aimed at exploring the methods and processes of opening band gap by the density functional theory calculations. Lattice symmetry of graphene has a great influence on its band structure, so a sizeable band gap will appears probably if this symmetry has been broken by chemical modification.For the adsorption of single atom, the size of the band gap has no direct relationship with the most stable adsorption position by the results of Au, Ag, Cu adsorption. Fe-graphene, Co-graphene and V-graphene three systems are all show metallic. O2and O3are activity, which have a great influence on graphene band gap, and make O2-graphene have magnetic properties and03-graphene show metallic.About the effects of doping, the redistribution of electronic destroyed the perfect sp2hybridization framework, result in that the O/graphene can open a large band gap of0.52eV at the same time to maintain a small deformation and stability of the structure. Affected by strong orbital hybridization, the system of Fe/graphene is also very satisfactory. Ga/graphene is the only one doping system by single metal atom which shows metallic.The combined action by adsorption and doping is not very ideal on the expanded of band gap, but it’s lucky to find that Cu/graphene has a catalytic role on the chemical reaction of carbon monoxide and oxygen. For double-layer graphene graphene lining in SiC substrate, the lower graphene has a buffer effect to the upper graphene, making it close to ideal graphene. |
PDF Full Text Request