Resonant Raman study of the structure and electronic properties of single-wall carbon nanotubes

We investigate the laser-energy dependence of the Raman profile of single-wall carbon nanotube (SWNT) samples with various distributions of diameters. We show that resonant Raman is an efficient tool for the study of the structure and electronic properties of SWNT. The tube diameter distribution is derived from the comparison between the experimental frequencies of the radial A1g breathing mode range (RBM) and the calculated RBM frequency of SWNT bundles. Metallic or semi-conducting tubes are identified in the light of calculations of allowed optical transitions. The assignments are confirmed by the observation (absence) of a Breit–Wigner–Fano-like lineshape for the tangential graphite-like modes of metallic (semiconducting) nanotubes.