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-w all carbon nanotube (SWNT) samples with various distributions of diameters. We show that resonant Raman is an efficient tool for the study of the stru cture and electronic properties of SWNT. The tube diameter distribution is derived from the comparison between the experimental frequencies of the rad ial A(1g) breathing mode range (RBM) and the calculated RBM frequency of SW NT bundles. Metallic or semi-conducting tubes are identified in the light o f calculations of allowed optical transitions. The assignments are confirme d by the observation (absence) of a Breit-Wigner-Fano-like lineshape for th e tangential graphite-like modes of metallic (semiconducting) nanotubes. (C ) 2000 Elsevier Science B.V. All rights reserved.