Edge chirality determination of graphene by Raman spectroscopy

Raman imaging of single layer micromechanical cleavage graphene was carried out. The intensity of disorder-induced Raman feature (D band at ∼1350cm−1) was found to be correlated to the edge chirality: it is stronger at the armchair edge and weaker at the zigzag edge. This shows that Raman spectroscopy is a reliable and practical method to identify the chirality of graphene edge and hence the crystal orientation. The determination of graphene chirality is critically important for fundamental study of graphene as well as applications of graphene-based devices.