Single carbon nanotubes probed by photoluminescence excitation spectroscopy: the role of phonon-assisted transitions.
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.
Htoon
H
H
Chemistry Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA.
O'Connell
M J
MJ
Doorn
S K
SK
Klimov
V I
VI
D008163:Luminescent Measurements / Q000379:methods*; D037742:Nanotubes, Carbon / Q000737:chemistry*
D037742:Nanotubes, Carbon