Free-standing graphene monolayers in carbon-based composite obtained from SiC: Raman diagnostics

Abstract

A carbon-based composite was obtained by an optimized method of high-temperature sublimation of polycrystalline SiC. Scanning electron microscopy of the composite detected flakes with lateral sizes of up to tens of microns and some fine-dispersed carbon material. From a thorough analysis of G and 2D bands in the Raman spectra measured within the flakes we conclude that the flakes consist of free-standing graphene monolayers of high quality, while the fine-dispersed material is mainly graphite. The proposed method of producing the graphene-containing composite is supposed to be very promising due to its relative simplicity and high mass output.