The Raman Fingerprint of Graphene

TL;DR

This paper demonstrates that graphene's electronic structure can be uniquely identified through its Raman spectrum, which evolves with the number of layers, enabling non-destructive layer identification.

Contribution

It introduces Raman spectroscopy as a reliable method to distinguish single, bi-, and few-layer graphene based on their electronic and phonon properties.

Findings

Raman spectra vary systematically with the number of graphene layers.

Distinct Raman fingerprints allow unambiguous layer identification.

The method provides a high-throughput, non-destructive way to analyze graphene.

Abstract

Graphene is the two-dimensional (2d) building block for carbon allotropes of every other dimensionality. It can be stacked into 3d graphite, rolled into 1d nanotubes, or wrapped into 0d fullerenes. Its recent discovery in free state has finally provided the possibility to study experimentally its electronic and phonon properties. Here we show that graphene's electronic structure is uniquely captured in its Raman spectrum that clearly evolves with increasing number of layers. Raman fingerprints for single-, bi- and few-layer graphene reflect changes in the electronic structure and electron-phonon interactions and allow unambiguous, high-throughput, non-destructive identification of graphene layers, which is critically lacking in this emerging research area.