A method to extract pure Raman spectrum of epitaxial graphene on SiC

TL;DR

This paper introduces a Non-negative Matrix Factorization method to accurately extract pure Raman spectra of epitaxial graphene on SiC, overcoming issues of negative intensities and resolution, without needing prior impulse response information.

Contribution

The paper presents a novel NMF-based approach for Raman spectrum extraction that improves resolution and data smoothing without requiring prior knowledge of system responses.

Findings

Successfully extracts pure Raman spectra of graphene on SiC

Overcomes negative spectral intensity issues

Efficiently smooths spectral data

Abstract

A method is proposed to extract pure Raman spectrum of epitaxial graphene on SiC by using a Non-negative Matrix Factorization. It overcomes problems of negative spectral intensity and poorly resolved spectra resulting from a simple subtraction of a SiC background from the experimental data. We also show that the method is similar to deconvolution, for spectra composed of multiple sub- micrometer areas, with the advantage that no prior information on the impulse response functions is needed. We have used this property to characterize the Raman laser beam. The method capability in efficient data smoothing is also demonstrated.