Step, ridge, and crack submicro/nanostructures of epitaxial graphene on C-face of 4H-SiC were characterized using tip-enhanced Raman scattering (TERS) spectroscopy. The nanostructures are smaller than resolution of normal Raman spectroscopy, so they cannot be probed individually with the conventional method. However, with the exceptional spatial resolution of TERS, reduced compressive strain on nanoridge and decreased graphene content in submicrometer crack were detected. This information provides an insight in the forming mechanism of nanostructures on epitaxial graphene.
K. Ashida, T. Kaneko, and Y. Ozaki*
J. Phys. Chem. C, 118, 25809−25815 (2014).