The electronic property of graphene adsorbed on the siloxane and silanol surface structures of SiO2: A theoretical prediction

Abstract

Using density functional theory calculations, we have investigated the effect of specific surface structures on the electronic properties of a graphene layer on the SiO2 substrate. Our results show that graphene monolayer is weakly bound to the siloxane and silanol surfaces via the van der Waals interactions with a binding energy of around 20%–40% of that in graphite. Our calculations also show that the silanol groups on the surface can induce significant valence charge redistribution in the interfacial region as well as on the graphene layer, which appear like the scattering centers that may degrade the carrier mobility in graphene. Nevertheless, we found no doping effect on graphene from the substrate for both the siloxane and silanol surface structures.