Polarized Raman Scattering of Epitaxial Graphene Prepared by Thermal Decomposition of SiC

Epitaxial graphene prepared by thermal decomposition of silicon carbide (SiC) can be applied to graphene-based electrical devices directly without transferring for the advantages of high electron mobility and easily compatible with the existing semiconductor technology. Characterizing the polarization dependence of epitaxial graphene favors the selection of device materials. However, the second-order polarized Raman spectra of 4H-SiC wafer were measured and found to exhibit polarization dependency, which would affect the polarization analysis of the G band of epitaxial graphene. In this paper, the polarization dependence of non-exfoliated monolayer and bilayer epitaxial graphene grown on 4H-SiC substrates were obtained after subtracting the second-order polarized Raman spectra of SiC wafer under the identical test conditions. Results indicated that the G band of epitaxial graphene shows non-polarization, while the 2D band shows strong polarization dependency. (C) 2018 The Electrochemical Society.