Graphene/g-C3N4 bilayer: considerable band gap opening and effective band structure engineering

Abstract

The layered graphene/g-C₃N₄ composites show high conductivity, electrocatalytic performance and visible light response and have potential applications in microelectronic devices and photocatalytic technology. In the present work, the stacking patterns and the correlations between electronic structures and related properties of graphene/g-C₃N₄ bilayers are investigated systematically by means of first-principles calculations. Our results indicate that the band gap of graphene/g-C₃N₄ bilayers can be up to 108.5 meV, which is large enough for the gap opening at room temperature. The calculated charge density difference unravels that the charge redistribution drives the interlayer charge transfer from graphene to g-C₃N₄. Interestingly, the investigation also shows that external electric field can tune the band gap of graphene/g-C₃N₄ bilayers effectively. Our research demonstrates that graphene on g-C₃N₄ with a tunable band gap and high carrier mobility may provide a novel way for fabricating high-performance graphene-based nanodevices.