Crystallographic orientation of early domains in CVD graphene studied by Raman spectroscopy

Crystallographic orientations of early multi-lobe graphene domains in CVD-grown graphene are investigated. Partially grown graphene domains were transferred onto flexible substrates and uniaxial tensile strain was applied. From the polarization dependence of the Raman G band, split due to strain, the crystallographic orientation was determined. It was found that there are some single crystal domains. However, lobes have different orientations in some other multi-lobe domains. Within a given lobe, the orientation does not change as the domain grows, indicating that the orientations present in a graphene domain are determined at an early stage of growth.