Raman spectroscopy at the edges of multilayer graphene

Individual graphene layers in a multilayer graphene sample contribute their own edges. The edge of a graphene layer laid on an n layer graphene (nLG) is a building block for the edges of multilayer graphenes. We found that the D band observed from the edge of the top graphene layer laid on the nLG exhibits an identical line shape to that of disordered (n + 1)LG. Based on the spectral features of the D and 2D bands, we identified two types of alignment configurations at the edges of bilayer and trilayer graphenes, whose edges are well-aligned from their optical images. (C) 2015 Elsevier Ltd. All rights reserved.