Edge Configurational Effect on Band Gaps in Graphene Nanoribbons

TL;DR

This paper investigates how edge configurations influence the electronic band gaps in graphene nanoribbons, resolving discrepancies between theoretical predictions and experimental results, and highlighting the importance of edge effects in nanoelectronic device design.

Contribution

It demonstrates that edge configurations significantly affect band gaps in GNRs, providing a detailed correlation with width and orientation, advancing band gap engineering strategies.

Findings

Direct band gaps observed in GNRs consistent with experiments

Edge configurations significantly influence band gap values

Band gap variations correlate with width and crystallographic orientation

Abstract

In this Letter, we put forward a resolution to the prolonged ambiguity in energy band gaps between theory and experiments of fabricated graphene nanoribbons (GNRs). Band structure calculations using density functional theory are performed on oxygen passivated GNRs supercells of customized edge configurations without disturbing the inherent sp2 hybridization of carbon atoms. Direct band gaps are observed for both zigzag and armchair GNRs, consistent with the experimental reports. In addition, band gap values of GNRs scattered about an average value curve for a given crystallographic orientation are correlated with their width on basis of the edge configurations elucidates the band gaps in fabricated GNRs. We conclude that edge configurations of GNRs significantly contribute to band gap formation in addition to its width for a given crystallographic orientation, and would play a crucial role in band gap engineering of GNRs for future research works on fabrication of nanoelectronic devices.