Article,
D band Raman intensity calculation in armchair edged graphene nanoribbons
PHYSICAL REVIEW B, (2011)
DOI: 10.1103/PhysRevB.83.245435
Abstract
The D band Raman intensity is calculated for armchair edged graphene
nanoribbons using an extended tight-binding method in which the effect
of interactions up to the seventh nearest neighbor is taken into
account. The possibility of a double resonance Raman process with
multiple scattering events is considered by calculating a T matrix
through a direct diagonalization of the nanoribbon Hamiltonian. We show
that long-range interactions play an important role in the evaluation of
both the D band intensity and that the main effect of multiple
scattering events on the calculated D band is an overall increase in
intensity by a factor of 4. The D band intensity is shown to be
independent of the nanoribbon widths for widths larger than 17 nm,
leading to the well-known linear dependence of the I(D)/I(G) ratio on
the inverse of the crystalline size. The D band intensity was shown to
be nearly independent of the laser excitation energy and to have a
maximum value for incident and scattering photons polarized along the
direction of the edge.
