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Triplet–triplet exciton dynamics in single-walled carbon nanotubes

Nature Photonics volume 8, pages 139144 (2014) | Download Citation

Abstract

Semiconducting single-walled carbon nanotubes (SWNTs) are considered as building blocks for novel optoelectronic and photonic devices. Energy transport, dissipation and nonlinear optical properties of such devices depend critically on the dynamics of singlet and triplet excitons. However, little is known about triplet excitons in SWNTs despite their important role in photovoltaic, photoelectric and other applications. We present pump–probe and spin-sensitive photoluminescence studies of semiconducting SWNTs that allow the determination of the quantum yield of triplet formation (5 ± 2%), the triplet lifetime (30 ± 10 µs) and the triplet exciton size (0.65 nm). Triplet–triplet annihilation is also found to induce delayed fluorescence. The power-law decay of pump–probe and time-resolved photoluminescence signals is characteristic of diffusion-limited annihilation in one-dimensional systems and allows an estimation of the triplet diffusion constant of 0.1 cm2 s−1. This work suggests that exciton annihilation in SWNTs is reduced by one-dimensional confinement of diffusive exciton motion.

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Acknowledgements

V.D. acknowledges financial support through ZAE Bayern, funded through the Bavarian Ministry of Economic Affairs, Infrastructure, Transport and Technology. T.H. acknowledges stimulating discussions with J. Allam.

Author information

Affiliations

  1. Institute of Physical and Theoretical Chemistry, Faculty of Chemistry and Pharmacy, Julius-Maximilian University Würzburg, Am Hubland, 97074 Würzburg, Germany

    • Dominik Stich
    • , Florian Späth
    •  & Tobias Hertel
  2. Institute of Physics, Faculty of Physics and Astronomy, Julius-Maximilian University Würzburg, Am Hubland, 97074 Würzburg, Germany

    • Hannes Kraus
    • , Andreas Sperlich
    •  & Vladimir Dyakonov
  3. Bavarian Center for Applied Energy Research e.V. (ZE Bayern), Am Hubland, 97074 Würzburg, Germany

    • Vladimir Dyakonov

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Contributions

D.S. and F.S. carried out the time-resolved photoluminescence measurements and prepared samples. H.K., A.S. and V.D. were responsible for ODMR experiments, their interpretation and design. T.H. and F.S. developed the kinetic model. All authors contributed to the interpretation of the results and writing of the manuscript.

Competing interests

The authors declare no competing financial interests.

Corresponding author

Correspondence to Tobias Hertel.

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DOI

https://doi.org/10.1038/nphoton.2013.316

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