Below-gap excitation of semiconducting single-wall carbon nanotubes.
We investigate the optoelectronic properties of the semiconducting (6,5) species of single-walled carbon nanotubes by measuring ultrafast transient transmission changes with 20 fs time resolution. We demonstrate that photons with energy below the lowest exciton resonance efficiently lead to linear excitation of electronic states. This finding challenges the established picture of a vanishing optical absorption below the fundamental excitonic resonance. Our result points towards below-gap electronic states as an intrinsic property of semiconducting nanotubes.
Department of Physics and Center for Applied Photonics, University of Konstanz, D-78457 Konstanz, Germany. gs544@cam.ac.uk daniele.brida@uni-konstanz.de and Dipartimento di Fisica, Politecnico di Milano, Piazza L. da Vinci 32, 20133 Milano, Italy.
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Soavi
Department of Physics and Center for Applied Photonics, University of Konstanz, D-78457 Konstanz, Germany. gs544@cam.ac.uk daniele.brida@uni-konstanz.de.
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Grupp
Department of Physics and Center for Applied Photonics, University of Konstanz, D-78457 Konstanz, Germany. gs544@cam.ac.uk daniele.brida@uni-konstanz.de.
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Budweg
Dipartimento di Fisica, Politecnico di Milano, Piazza L. da Vinci 32, 20133 Milano, Italy and IFN-CNR, Piazza L. da Vinci, 32, 20133 Milano, Italy.
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Scotognella
Inst. for Physical and Theoretical Chemistry Dept. of Chemistry and Pharmacy, University of Würzburg, Würzburg 97074, Germany.
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Hefner
Inst. for Physical and Theoretical Chemistry Dept. of Chemistry and Pharmacy, University of Würzburg, Würzburg 97074, Germany.
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Hertel
Center for Nano Science and Technology@PoliMi, Istituto Italiano di Tecnologia, Via Giovanni Pascoli, 70/3, 20133 Milano, Italy.
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Lanzani
Department of Physics and Center for Applied Photonics, University of Konstanz, D-78457 Konstanz, Germany. gs544@cam.ac.uk daniele.brida@uni-konstanz.de.
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Leitenstorfer
Dipartimento di Fisica, Politecnico di Milano, Piazza L. da Vinci 32, 20133 Milano, Italy and IFN-CNR, Piazza L. da Vinci, 32, 20133 Milano, Italy.
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Cerullo
Department of Physics and Center for Applied Photonics, University of Konstanz, D-78457 Konstanz, Germany. gs544@cam.ac.uk daniele.brida@uni-konstanz.de.
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Brida