Electronic structure of epitaxial graphene nanoribbons on SiC(0001)

TL;DR

This paper investigates the electronic properties of epitaxial graphene nanoribbons on SiC(0001), emphasizing the critical influence of interface interactions and Fermi level pinning on their conductivity, regardless of nanoribbon width.

Contribution

It provides an atomistic analysis showing the interface's role in electronic behavior, highlighting Fermi level pinning as a dominant factor affecting conductivity.

Findings

Interface interactions dominate electronic properties.

Fermi level pinning occurs independently of nanoribbon width.

Confinement effects are less significant due to interface phenomena.

Abstract

We present electronic structure calculations of few-layer epitaxial graphene nanoribbons on SiC(0001). Trough an atomistic description of the graphene layers and the substrate within the extended H\"{u}ckel Theory and real/momentum space projections we argue that the role of the heterostructure's interface becomes crucial for the conducting capacity of the studied systems. The key issue arising from this interaction is a Fermi level pinning effect introduced by dangling interface bonds. Such phenomenon is independent from the width of the considered nanostructures, compromising the importance of confinement in these systems.