Theoretical Study of Corundum as an Ideal Gate Dielectric Material for Graphene Transistors

摘要

Using physical insights and advanced first-principles calculations, wesuggest that corundum is an ideal gate dielectric material for graphenetransistors. Clean interface exists between graphene and Al-terminated (orhydroxylated) Al2O3 and the valence band offsets for these systems are largeenough to create injection barrier. Remarkably, a band gap of {\guillemotright}180 meV can be induced in graphene layer adsorbed on Al-terminated surface,which could realize large ON/OFF ratio and high carrier mobility in graphenetransistors without additional band gap engineering and significant reductionof transport properties. Moreover, the band gaps of graphene/Al2O3 system couldbe tuned by an external electric field for practical applications.