Long lived photo excitations in (6, 5) carbon nanotubes
Abstract
We study the photo-induced transmission change (ΔT/T) upon quasi-continuum laser excitation, for different modulation frequency and excitation intensity in films of (6, 5) enriched CoMoCat single wall nanotubes (SWNTs) embedded in a polymeric matrix. This technique probes long-lived excited species, with lifetime in the 1 ms–1 s domain. The observed line-shape of ΔT/T spectra that can be assigned to a superposition of ground state bleaching and absorption modulation. We speculate that photo-excitation creates charges which get trapped in the sample, acquiring ms lifetime. This causes bleaching of the ground state absorption due to state filling and possibly a tube diameter expansion, with consequent blue shift of the optical transition.
- Publication:
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European Physical Journal B
- Pub Date:
- May 2010
- DOI:
- 10.1140/epjb/e2009-00374-1
- Bibcode:
- 2010EPJB...75..115S
- Keywords:
-
- 33.20.Ea Infrared spectra;
- 33.20.Kf Visible spectra;
- 42.62.Fi Laser spectroscopy;
- 33.20.Ea;
- 33.20.Kf;
- 42.62.Fi;
- Infrared spectra;
- Visible spectra;
- Laser spectroscopy