Chemical Bondings Induced Rich Electronic Properties of Oxygen Absorbed Few-layer Graphenes

TL;DR

This study uses first-principle calculations to explore how oxygen chemical bonding alters the electronic properties of few-layer graphene oxides, revealing diverse behaviors such as band gap opening and Dirac cone distortion.

Contribution

It provides a detailed analysis of the electronic structure changes in graphene oxides due to oxygen bonding, considering layer number, stacking, and oxygen distribution, which was not comprehensively studied before.

Findings

Most graphene oxides are semi-metals, except monolayers which are semiconductors.

Oxygen bonding causes Dirac cone distortion and band gap opening.

Distinct electronic features are linked to specific chemical bonds like C-O and O-O.

Abstract

Electronic properties of graphene oxides enriched by the strong chemical bondings are investigated using first-principle calculations. They are very sensitive to the changes in the number of graphene layer, stacking configuration, and distribution of oxygen. The feature-rich electronic structures exhibit the destruction or distortion of Dirac cone, opening of band gap, anisotropic energy dispersions, O- and (C,O)-dominated energy dispersions, and extra critical points. All the few-layer graphene oxides are semi-metals except for the semiconducting monolayer ones. For the former, the distorted Dirac-cone structures and the O-dominated energy bands near the Fermi level are revealed simultaneously. The orbital-projected density of states (DOS) have many special structures mainly coming from a composite energy band, the parabolic and partially flat ones. The DOS and spatial charge distributions clearly indicate the critical bondings in O-O, C-O and C-C bonds, being responsible for the diversified properties.