Raman Topography and Strain Uniformity of Large-Area Epitaxial Graphene

TL;DR

This study uses 2D Raman spectroscopy and atomic force microscopy to analyze strain distribution in large-area epitaxial graphene on SiC, revealing significant inhomogeneity but also the potential for strain-free graphene.

Contribution

It demonstrates the correlation between Raman spectral variations and physical topography, showing that strain-free epitaxial graphene can be achieved.

Findings

Large variation in Raman peak position across samples

Correlation between strain and surface topography

Potential for producing strain-free epitaxial graphene

Abstract

We report results from two-dimensional Raman spectroscopy studies of large-area epitaxial graphene grown on SiC. Our work reveals unexpectedly large variation in Raman peak position across the sample resulting from inhomogeneity in the strain of the graphene film, which we show to be correlated with physical topography by coupling Raman spectroscopy with atomic force microscopy. We report that essentially strain free graphene is possible even for epitaxial graphene.