Article abstract
Nature Physics 5, 54 - 58 (2009)
Published online: 23 November 2008 | doi:10.1038/nphys1149
Subject Categories: Condensed-matter physics | Electronics, photonics and device physics | Nanotechnology
Size and mobility of excitons in (6, 5) carbon nanotubes
Larry Lüer1, Sajjad Hoseinkhani1, Dario Polli2, Jared Crochet3, Tobias Hertel3 & Guglielmo Lanzani2
Abstract
Knowledge of excited-state dynamics in carbon nanotubes is determinant for their prospective use in optoelectronic applications. It is known that primary photoexcitations are quasi-one-dimensional excitons, the electron–hole correlation length ('exciton size') of which corresponds to a finite volume in the phase space. This volume can be directly measured by nonlinear spectroscopy provided the time resolution is short enough for probing before population relaxation. Here, we report on the experimental determination of exciton size and mobility in (6, 5) carbon nanotubes. The samples are sodium cholate suspensions of nanotubes (produced by the CoMoCat method) obtained by density-gradient ultracentrifugation. By using sub-15 fs near-infrared pulses to measure the nascent bleach of the lowest exciton resonance, we estimate the exciton size to be 2.0
0.7 nm. Exciton–exciton annihilation in our samples is found to be rather inefficient so that many excitons can coexist on a single nanotube.
- National Laboratory for Ultrafast and Ultraintense Optical Science, INFM-CNR, Dipartimento di Fisica, Politecnico di Milano, Italy
- Italian Institute of Technology and Dipartimento di Fisica, Politecnico di Milano, P.za L. da Vinci 32, 20133 Milano, Italy
- Institut für Physikalische Chemie, Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
Correspondence to: Larry Lüer1 e-mail: larry.luer@fisi.polimi.it
MORE ARTICLES LIKE THIS
These links to content published by NPG are automatically generated.
NEWS AND VIEWS
Quantum coherence An ideal 1D quantum wire?Nature Physics News and Views (01 Jan 2006)
Quantum dots A new quantum state?Nature Materials News and Views (01 Sep 2005)
See all 6 matches for News And ViewsRESEARCH
A microcavity-controlled, current-driven, on-chip nanotube emitter at infrared wavelengthsNature Nanotechnology Letter (01 Oct 2008)
Real-time observation of nonlinear coherent phonon dynamics in single-walled carbon nanotubesNature Physics Letter (01 Aug 2006)
See all 45 matches for Research
