Carbon Nanostructure Characterization by Optics and Resonance Raman Scattering

A review is presented on optical and Raman characterization of carbon nanostructures. Particular attention is paid to the new phases of carbon such as fullerenes, poly-fullerenes and carbon nanotubes. For the case of the polyfullerenes the two isostructural dimeres (C59N)2 and (C60)2 are discussed in detail. Both structures exhibit a very strong resonance for red laser excitation of the radial modes. The frequency of the radial breathing mode of single wall carbon nanotubes is shown to exhibit an oscillating behavior as a function of the excitation energy. A quantitative analysis performed for a quasi-continuous distribution of diameters revealed 2.9 eV as the best value for the π-overlap γ0 and an 8% up shift of the mode due to the tube-tube interaction in the bundle.