Probing the Phonon-Assisted Relaxation Process in DNA-wrapped Carbon Nanotubes Using Polarization Dependent Optical Spectroscopy

In this study, polarization-dependent spectroscopy is carried out on DNA-wrapped single walled nanotube hybrids, deposited onto a Sapphire substrate. By using a nanotube sample highly enriched in one specific (n,m) species and an intense light source, the various phonon-assisted excitonic relaxation processes, in addition to the commonly observed electronic interband transitions, can be separately identified and studied in detail. The phonon-assisted relaxation processes involving different phonon branches is emphasized in this study. The MIT authors acknowledge supports under the Dupont-MIT Alliance, NSF Grants DMR 04-05538.