Raman spectroscopy as probe of nanometer-scale strain variations in graphene

TL;DR

This paper demonstrates that the Raman 2D line width can serve as a non-invasive indicator of nanometer-scale strain variations and structural quality in graphene, providing a useful characterization tool.

Contribution

It reveals that the Raman 2D line width reflects nanometer-scale strain variations in graphene, enabling improved assessment of its structural quality.

Findings

Raman 2D line width correlates with nanometer-scale strain variations.

The 2D line width provides information on graphene flatness and lattice deformations.

This method allows classification of graphene quality even without magnetic fields.

Abstract

Confocal Raman spectroscopy is a versatile, non-invasive investigation tool and a major workhorse for graphene characterization. Here we show that the experimentally observed Raman 2D line width is a measure of nanometer-scale strain variations in graphene. By investigating the relation between the G and 2D line at high magnetic fields we find that the 2D line width contains valuable information on nanometer-scale flatness and lattice deformations of graphene, making it a good quantity for classifying the structural quality of graphene even at zero magnetic field.