Exponential decay lifetimes of excitons in individual single-walled carbon nanotubes

Reviews and Highlights	Quantum Science	Molecular and Soft-matter	Ultrafast Nano-optics and Nanophotonics	Mineralogy and Geochemistry

Axel Hagen, Mathias Steiner, Markus B Raschke, Christoph Lienau, Tobias Hertel, Huihong Qian, Alfred J Meixner, and Achim Hartschuh
Phys. Rev. Lett. 95, 197401 (2005).
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The dynamics of excitons in individual semiconducting single-walled carbon nanotubes was studied using time-resolved photoluminescence (PL) spectroscopy. The PL decay from tubes of the same (n,m) type was found to be monoexponential, however, with lifetimes varying between less than 20 and 200 ps from tube to tube. Competition of nonradiative decay of excitons is facilitated by a thermally activated process, most likely a transition to a low-lying optically inactive trap state that is promoted by a low-frequency phonon mode.