Observations of the<i>D</i>-band feature in the Raman spectra of carbon nanotubes

Abstract

We examine the behavior of the D-band feature in the Raman spectra of single-walled carbon nanotube (SWNT) bundles, observed between 1250 and $1450 {\mathrm{cm}}^{\ensuremath{-}1},$ as a function of the laser excitation energy. We used three SWNT samples with different diameters, and show that the D-band behavior of SWNTs differs from ${\mathrm{sp}}^{2}$ carbons, depending on whether the SWNTs are metallic or semiconducting, and shows a frequency ${\ensuremath{\omega}}_{D}$ that is dependent on nanotube diameter.