Theoretical study of corundum as an ideal gate dielectric material for graphene transistors

Using physical insights and advanced first-principles calculations, we suggest that corundum (α-Al₂O₃) is an ideal gate dielectric material for graphene transistors. Clean interface exists between graphene and Al-terminated (or hydroxylated) Al₂O₃ and the valence-band offsets for these systems are large enough to create an injection barrier. Remarkably, a band gap of ~180 meV can be induced in a graphene layer adsorbed on an Al-terminated surface with an electron effective mass of ~8 × 10^-3mₑ. Moreover, the band gaps of a graphene/Al₂O₃ system could be tuned by an external electric field for practical applications.