Raman spectroscopy on mechanically exfoliated pristine graphene ribbons

TL;DR

This study uses Raman spectroscopy to analyze pristine graphene nanoribbons, revealing insights into edge disorder, crystallographic orientation, and phonon mode variations related to ribbon width, with implications for high-quality graphene fabrication.

Contribution

It demonstrates that non-etched graphene ribbons have larger edge disorder correlation lengths and more regular crystallographic edges compared to etched counterparts.

Findings

Edge disorder correlation length is significantly larger in non-etched ribbons.

Raman D-line intensity depends strongly on light polarization.

Line-width and frequency of G and 2D lines vary with ribbon width.

Abstract

We present Raman spectroscopy measurements of non-etched graphene nanoribbons, with widths ranging from 15 to 160 nm, where the D-line intensity is strongly dependent on the polarization direction of the incident light. The extracted edge disorder correlation length is approximately one order of magnitude larger than on previously reported graphene ribbons fabricated by reactive ion etching techniques. This suggests a more regular crystallographic orientation of the non-etched graphene ribbons here presented. We further report on the ribbons width dependence of the line-width and frequency of the long-wavelength optical phonon mode (G-line) and the 2D-line of the studied graphene ribbons.