title: Spectroscopic signatures of topological and diatom-vacancy defects in single-walled carbon nanotubes.
abstract: The optical properties, including UV-vis spectra and resonance Raman profiles, of pristine and defected single-walled carbon nanotubes (SWCNTs) are computed using state-of-the-art time-dependent density functional theory (TDDFT) as implemented using the Liouville-Lanczos approach to linear-response TDDFT. The CNT defects were of the form of Stone-Wales and diatom-vacancies. Our results are in very good agreement with experimental results where defects were introduced into a part of defect-free CNTs. In particular, we show that the first and second π-π* excitation energies are barely shifted due to the defects and associated with a relatively small reduction in the maxima of the absorption bands. In contrast, the resonance Raman spectra show close to an order of magnitude reduction in intensities, offering a means to distinguish between pristine and defected SWCNTs even at low defect concentrations.
authors.affiliation: Department of Chemical and Petroleum Engineering, University of Pittsburgh, Pittsburgh, PA 15261, USA. alsaidi@pitt.edu.
authors.forename: Wissam A
authors.initials: WA
authors.lastname: Saidi
authors.forename: Patrick
authors.initials: P
authors.lastname: Norman
mesh_terms: D037742:Nanotubes, Carbon / Q000737:chemistry*; D013056:Spectrophotometry, Ultraviolet; D013059:Spectrum Analysis, Raman
chemical_list: D037742:Nanotubes, Carbon