Electronic structure of a realistic model of amorphous graphene

TL;DR

This paper investigates the electronic properties of a realistic amorphous graphene model, revealing how odd-membered rings influence the density of states and potentially alter graphene's exotic properties.

Contribution

It introduces a realistic atomistic model of amorphous graphene with odd-membered rings and analyzes its electronic structure, highlighting differences from crystalline graphene.

Findings

Odd-membered rings increase the density of states at the Fermi level.

Amorphous regions can significantly affect graphene's electronic properties.

Estimates of the density of states at the Fermi level are provided using a tight-binding model.

Abstract

In this note, we calculate the electronic properties of a realistic atomistic model of amorphous graphene. The model contains odd membered rings, particularly five and seven membered rings and no coordination defects. We show that odd-membered rings increase the electronic density of states at the Fermi level relative to crystalline graphene; a honeycomb lattice with semi-metallic character. Some graphene samples contain amorphous regions, which even at small concentrations, may strongly affect many of the exotic properties of crystalline graphene, which arise because of the linear dispersion and semi-metallic character of perfectly crystalline graphene. Estimates are given for the density of states at the Fermi level using a tight-binding model for the $\pi$ states.