Resonance behavior of the defect-induced Raman mode of single-chirality enriched carbon nanotubes

Abstract

We present a resonance Raman study of the disorder-induced $D$ mode in a sample highly enriched with semiconducting (9,7) single-walled carbon nanotubes in the excitation energy range of $1.49--2.05\phantom{\rule{0.16em}{0ex}}\mathrm{eV}$. The intensity of the $D$ mode shows a resonance behavior near the optical transition of the (9,7) tube. The well-known dispersion of the $D$-mode frequency, on the other hand, is not observed at the resonance, but only above a certain excitation energy. We explain our results by numerical simulations of the $D$-mode spectra.