Chemical reactivity and band-gap opening of graphene doped with gallium, germanium, arsenic, and selenium atoms.

Abstract

Herein, the effects of substitutional doping of graphene with Ga, Ge, As, and Se are shown. Ge exhibits the lowest formation energy, whereas Ga has the largest one. Ga- and As-doped graphene display a reactivity that is larger than that corresponding to a double vacancy. They can decompose H2 and O2 easily. Variation of the type and concentration of dopant makes the adjustment of the interlayer interaction possible. In general, doping of monolayer graphene opens a band gap. At some concentrations, Ga doping induces a half metallic behavior. As is the element that offers the widest range of gap tuning. Heyd-Scuseria-Ernzerhof calculations indicate that it can be varied from 1.3 to 0.3 eV. For bilayer graphene, the doped sheet induces charge redistribution in the perfect underneath sheet, which opens a gap in the range of 0.05-0.4 eV. This value is useful for developing graphene-based electronics, as the carrier mobility of the undoped sheet is not expected to alter.