Structural dependence of excitonic optical transitions and band-gap energies in carbon nanotubes.
The optical transitions of semiconducting carbon nanotubes have been ascribed to excitons. Here we use two-photon excitation spectroscopy to measure exciton binding energies, as well as band-gap energies, in a range of individual species of semiconducting SWNTs. Exciton binding energies are large and vary inversely with nanotube diameter, as predicted by theory. Band-gap energies are significantly blue-shifted from values predicted by tight-binding calculations.
Dukovic
Gordana
G
Department of Chemistry, Columbia University, 3000 Broadway, New York 10027, USA. gd2012@columbia.edu
Wang
Feng
F
Song
Daohua
D
Sfeir
Matthew Y
MY
Heinz
Tony F
TF
Brus
Louis E
LE