Few layer graphene on SiC, pyrolitic graphite and graphene: a Raman scattering study

TL;DR

This study uses micro-Raman scattering to compare the electronic and structural properties of graphene on SiC, pyrolytic graphite, and exfoliated graphene, revealing weak interlayer coupling in SiC-derived graphene.

Contribution

It provides new insights into the electronic decoupling of graphene layers on SiC, showing they behave like isolated graphene monolayers despite multiple layers.

Findings

Graphene on SiC shows single-component Raman features similar to monolayer graphene.

Weak electronic coupling between layers on SiC surface.

Graphene multilayers on SiC exhibit Dirac-like band structure.

Abstract

The results of micro-Raman scattering measurements performed on three different ``graphitic'' materials: micro-structured disks of highly oriented pyrolytic graphite, graphene multi-layers thermally decomposed from carbon terminated surface of 4H-SiC and an exfoliated graphene monolayer are presented. Despite its multi-layer character, most parts of the surface of the graphitized SiC substrates shows a single-component, Lorentzian shape, double resonance Raman feature in striking similarity to the case of a single graphene monolayer. Our observation suggests a very weak electronic coupling between graphitic layers on the SiC surface, which therefore can be considered to be graphene multi-layers with a simple (Dirac-like) band structure.