Metallic and semimetallic properties of doped graphene and boron nitride planes

Abstract

This is a study on the effects of impurity doping on the density of states of the graphene plane as well as hexagonal boron nitride sheet within the random tight-binding model and Green's function technique. We consider dopants as boron and nitrogen atoms in graphene and carbon atoms in boron nitride plane. We find that the band width of graphene increases in the presence of impurity atoms. Furthermore, appearing a finite density of states at zero energy due to doping by both boron and nitrogen atoms leads to metallic property in the graphene sheet. Our results also show that doping by carbon reduces the band gap of the boron nitride system. In high concentration of carbon atoms, the density of states of boron nitride plane becomes similar to that of graphene sheet, resulting in semimetallic behavior. We also recognize that the van-Hove singularities in the density of states of both systems are broadened. Moreover, all effects of impurities on their density of states depend on doping concentrations.