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

Bing Huang, Qiang Xu, and Su-Huai Wei

Phys. Rev. B 84, 155406 – Published 7 October 2011

Abstract

Using physical insights and advanced first-principles calculations, we suggest that corundum ( $α$ -Al $_{2}$ O $_{3}$ ) is an ideal gate dielectric material for graphene transistors. Clean interface exists between graphene and Al-terminated (or hydroxylated) Al $_{2}$ O $_{3}$ and the valence-band offsets for these systems are large enough to create an injection barrier. Remarkably, a band gap of $\sim$ 180 meV can be induced in a graphene layer adsorbed on an Al-terminated surface with an electron effective mass of $\sim$ 8 $\times$ 10 $^{- 3}$ $m$ $_{e}$ . Moreover, the band gaps of a graphene/Al $_{2}$ O $_{3}$ system could be tuned by an external electric field for practical applications.