An Alternative Strategy to Control the Electronic Properties of Bilayer Graphene: Semi-metal to Metal Transition and a 2D Material with Dirac Cone

TL;DR

This paper proposes an alternative method to tune the electronic properties of bilayer graphene by intercalating transition metal atoms, enabling control over its transition from semi-metal to metal and inducing Dirac cones.

Contribution

It introduces a novel intercalation strategy with transition metals, especially Vanadium, to modulate the electronic phases of bilayer graphene, expanding the methods beyond doping and gating.

Findings

BLG-intercalated with Vanadium exhibits a Dirac cone at the K-point.

The electronic properties can be tuned by varying V atom concentration and spin arrangement.

Intercalation influences in-plane electronic densities via out-of-plane atoms.

Abstract

The AB-stacked bilayer graphene (BLG) is a pure semiconductor whose band gap and properties can be tuned by various methods such as doping or applying gate voltage. Here we show an alternative method to control the electronic properties of BLG; intercalation of transition metal atoms between the two monolayers graphene (MLG). A theoretical investigation has been performed on two-dimensional MLG, BLG, BLG-intercalated nanostructured materials, all of which are energetically stable. Our study reveals that only MLG and BLG-intercalated with one Vanadium (V) atom (BLG-1V) materials have a Dirac Cone at the K-point. This study reveals a new strategy to control the material properties of BLG to exhibit various behaviors, including: metallic, semi-metallic, and semiconducting by varying the concentration and spin arrangement of the V atoms in BLG. In all the cases, the present DFT calculations show that the 2p$_z$ sub-shells of C atoms in graphene and the 3d$_{yz}$ sub-shells of the V atoms provide the electron density near the Fermi level controlling the material properties of the BLG-intercalated materials. Thus we prove that out-of-plane atoms can influence in plane electronic densities in BLG.