Determination of edge purity in bilayer graphene using μ-Raman spectroscopy

Abstract

Polarization resolved μ-Raman spectroscopy was carried out at the edges of bilayer graphene. We find strong dependence of the intensity of the G band on the incident laser polarization, with its intensity dependence being 90° out of phase for the armchair and zigzag case, in accordance with theoretical predictions. For the case of mixed-state edges we demonstrate that the polarization contrast reflects the fractional composition of armchair and zigzag edges, providing a monitor of edge purity, which is an important parameter for the development of efficient nanoelectronic devices.