Optical Signatures of Strain Differences in Epitaxial Graphene Nanoribbons

TL;DR

This study presents a polymer-assisted sublimation growth method for preparing high-quality armchair and zigzag epitaxial graphene nanoribbons on 4H-SiC, revealing optical signatures of strain differences and supporting their expected electrical behaviors.

Contribution

It introduces a novel polymer-assisted sublimation technique for GNR fabrication that reduces deformation risks and provides insights into strain-related optical signatures.

Findings

Optical signatures differentiate strain in GNRs

Electrical behaviors align with theoretical expectations

Method reduces GNR deformation risk

Abstract

We demonstrate the preparation of both armchair and zigzag epitaxial graphene nanoribbons (GNRs) on 4H-SiC using a polymer-assisted, sublimation growth method. Historically, the preparation of GNRs depended on the quality, or smoothness, of the surface changes during growth. The physical phenomenon of terrace step formation introduces the risk of GNR deformation along sidewalls, but the risk is heavily mitigated by this polymer-assisted sublimation method. Two widths (100 nm and 50 nm) are examined electrically and optically for both armchair and zigzag GNRs. Our electrical results support the expected behaviors of the GNRs, while the optical signatures of variable strain reveal the subtle differences among all the GNR species measured.