▎ 摘　　要

Using Raman spectroscopy, we have characterised the optical and mechanical properties of a large macro-island area (150 mu m(2)) of four layer epitaxial graphene grown on a 4H-SiC (000 (1) over bar) substrate. Local Raman mapping showed an inhomogeneously stressed macro-island. There, the 2D and G Raman modes revealed a large frequency red-shift in this island with a decreasing temperature. An unexpected change appeared in the Raman spectra due to the inhomogeneous strain effect which was described in detail. Uniaxial and biaxial strains have been identified. (C) 2013 Elsevier B.V. All rights reserved.