Dresden 2011 – wissenschaftliches Programm
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HL: Fachverband Halbleiterphysik
HL 44: Poster Session I
HL 44.10: Poster
Dienstag, 15. März 2011, 18:00–21:00, P3
Controlling exciton decay in semiconducting carbon nanotubes by surface acoustic waves — Markus Regler1,2, Hubert J. Krenner2, Alexander A. Green3, Mark C. Hersam3, Achim Wixforth2, and •Achim Hartschuh1 — 1Department Chemie & CeNS, Ludwig Maximilians Universität München, Germay — 2Department Physik, Universität Augsburg, Germany — 3Department of Materials Science and Engineering, Northwestern University, Evanston, Illinois, USA
Single-walled carbon nanotubes (SWNTs) are quasi-1 dimensional direct-bandgap materials with unique properties making them promising candidates for a variety of technological applications including photonics, optoelectronics and sensing. The excited states of semiconducting SWNTs are formed by strongly bound luminescent excitons that can be populated either by light absorption or electrically [1]
We show that the decay dynamics of excitons in SWNTs can be controlled by surface acoustic waves (SAWs) launched in piezoelectric substrates. The photoluminescence (PL) intensity of nanotube films deposited on LiNbO3 was found to be reduced by up to 40% depending on the SAW amplitude. Time-resolved PL measurements reveal that the intensity reduction is caused by a SAW-induced decrease of the radiative exciton recombination rate that results from the electric fields associated with the SAW.
[1] P. Avouris, M. Freitag, V. Perebeinos, Nature Photon. 2, 341 (2008)