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

TL;DR

This study uses first-principles calculations to propose corundum as an ideal gate dielectric for graphene transistors, enabling large band gaps and tunable electronic properties without degrading mobility.

Contribution

It provides a theoretical analysis demonstrating corundum's suitability as a gate dielectric, including interface quality and tunable band gaps in graphene transistors.

Findings

Corundum forms a clean interface with graphene.

A band gap of about 180 meV can be induced in graphene.

The band gap can be tuned by an external electric field.

Abstract

Using physical insights and advanced first-principles calculations, we suggest that corundum 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 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 graphene transistors without additional band gap engineering and significant reduction of transport properties. Moreover, the band gaps of graphene/Al2O3 system could be tuned by an external electric field for practical applications.