The optical properties, including UV-vis spectra and resonance Raman profiles, of pristine and defected single-walled carbon nanotubes were computed using state-of-the-art time-dependent density functional theory as implemented using the Liouville-Lanczos approach to linear-response time-dependent density functional theory. The carbon nanotube defects were of the form of Stone-Wales and diatomic vacancies. The results were in very good agreement with experimental results where defects were introduced into a part of defect-free carbon nanotubes. In particular, it was shown that the first and second π-π* excitation energies were barely shifted due to the defects and were associated with a relatively small reduction in the maxima of the absorption bands. In contrast, the resonance Raman spectra showed almost an order of magnitude reduction in intensity; offering a means to distinguish between pristine and defected single-walled carbon nanotubes, even at low defect concentrations.

Spectroscopic Signatures of Topological and Diatom-Vacancy Defects in Single-Walled Carbon Nanotubes. W.A.Saidi, P.Norman: Physical Chemistry Chemical Physics, 2014, 16[4], 1479-86