title: Single carbon nanotubes probed by photoluminescence excitation spectroscopy: the role of phonon-assisted transitions.
abstract: We study light absorption mechanisms in semiconducting carbon nanotubes using low-temperature, single-nanotube photoluminescence excitation spectroscopy. In addition to purely electronic transitions, we observe several strong phonon-assisted bands due to excitation of one or more phonon modes together with the first electronic state. In contrast with a small width of emission lines (sub-meV to a few meV), most of the photoluminescence excitation features have significant linewidths of tens of meV. All of these observations indicate very strong electron-phonon coupling that allows efficient excitation of electronic states via phonon-assisted processes and leads to ultrafast intraband relaxation due to inelastic electron-phonon scattering.
authors.affiliation: Chemistry Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA.
authors.forename: H
authors.initials: H
authors.lastname: Htoon
authors.forename: M J
authors.initials: MJ
authors.lastname: O'Connell
authors.forename: S K
authors.initials: SK
authors.lastname: Doorn
authors.forename: V I
authors.initials: VI
authors.lastname: Klimov
mesh_terms: D008163:Luminescent Measurements / Q000379:methods*; D037742:Nanotubes, Carbon / Q000737:chemistry*
chemical_list: D037742:Nanotubes, Carbon