Triple‐resonant two‐phonon Raman scattering in graphene

The triple‐resonant (TR) second‐order Raman scattering mechanism in graphene is re‐examined. It is shown that the magnitude of the TR contribution to the photon‐G′ mode coupling function in graphene is one order of magnitude larger than the widely accepted two‐resonant coupling. Enhancement of the order of 100 in the Raman intensity, with respect to the usual double‐resonant model, is found for the G′ band in graphene, and is expected in the related sp²‐based carbon materials, as well. Copyright © 2011 John Wiley & Sons, Ltd.