In situ Raman spectroelectrochemical studies of CoMo-Cat single-walled carbon nanotubes enriched in (6,5) tubes have been carried out recently. We performed calculations on the density functional level using local density approximation for the electronic and vibrational properties of the most abundant tubes in these samples. The following chiral semiconducting tubes were investigated: (6,4), (7,3), (6,5), (9,1), (8,3) and (7,5). The calculated and the measured frequencies of the RBM and G- modes agree within several wave numbers. The calculated E11, E22 transition energies -after 30% and 20% upscaling, respectively- are comparable with the experimental values. The quenching of the RBM band with p- and n-doping can be interpreted within the rigid band approximation. The validity of the rigid band approximation was shown by calculating the density of states for neutral and charged tubes.
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics