Hydrogen intercalation: An approach to eliminate silicon dioxide substrate doping to graphene

We present an effective approach to eliminate SiO2 substrate doping to graphene by hydrogen intercalation during thermal annealing treatments. Owing to the high temperature applied, the conventional vacuum annealing process creates oxygen deficiency defects and dangling bonds in the substrate, which change the p-doped graphene to the heavily n-doped type. In contrast, an annealing process in hydrogen ambient leads to hydrogen intercalation at the graphene-SiO2 interface, which could effectively terminate the dangling bonds on the substrate formed during the high-temperature process. Hence, the supported graphene can stay "uncontaminated" by the substrate.