Stacking sequence dependence of electronic properties in double-layer graphene heterostructures

TL;DR

This study uses first-principles calculations to explore how stacking sequences in double-layer graphene with h-BN layers influence stability and electronic properties, revealing that stacking order determines metallic or semiconducting behavior.

Contribution

It demonstrates the impact of stacking sequence on electronic properties and stability of double-layer graphene heterostructures, providing a detailed orbital interaction model.

Findings

Ab-stacking is the most stable configuration.

Stacking sequence modulates electronic states into metallic or semiconducting.

Orbital interaction model accurately describes energy band structure dependence.

Abstract

First-principles calculation has been performed to investigate the stability and electronic properties of double-layer graphene heterostructure (DLGH). In this system, two graphene layers are separated by hexagonal boron-nitride (h-BN) layers which work as a insulating barrier. Our results show that the stability of the system is determined by the atomistic configurations between graphene and its adjacent h-BN layer. Among different stacking sequences, Ab-stacking is most stable. Since the inserted h-BN layers modulate the on-site energies for carbon atoms of graphene layers, the electronic states of the system can be classified into metallic or semiconducting by the stacking sequence. And the stacking sequence dependence of the energy band structures of DLGHs are well described by the orbital interaction model.