Stokes/anti‐Stokes Raman Spectroscopy of HiPco Single‐Wall Carbon Nanotubes

Abstract

An analysis of the Raman spectra of single‐walled HiPco carbon nanotube powder using laser energies of 1.92 eV, 2.4 eV, 2.5 eV and 2.7 eV, including a comparison of the Stokes and anti‐Stokes contributions is presented. The diameter distribution was determined to be 0.8 – 1.2 nm from the spectral positioning of the Radial Breathing Modes. The diameter distribution is consistent with that determined by NIR absorption spectroscopy. At all excitation energies the profile of the G‐line (≈ 1580cm−1) indicates a predominance of semiconducting tubes although at 2.4 eV there is some indication of some contribution from metallic tubes. In all cases the anti Stokes line was weak and the Stokes/anti Stokes ratio was at least an order of magnitude indicating at most weak resonance enhancement in either.