Near-infrared photoluminescence in the femtosecond time region in monolayer graphene on SiO2

Takeshi Koyama, Yoshito Ito, Kazuma Yoshida, Masaharu Tsuji, Hiroki Ago, Hideo Kishida, Arao Nakamura

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    17 Citations (Scopus)

    Abstract

    We investigate the dynamical properties of photoexcited carriers in a single monolayer of graphene at room temperature in air using femtosecond time-resolved luminescence spectroscopy. The luminescence kinetics are observed in the near-infrared region of 0.7-1.4 eV and analyzed based on the two-temperature model describing the cooling of thermalized carriers via the carrier-optical phonon interaction. The observed luminescence in the range 0.7-0.9 eV is well reproduced by the model. In the range 1.0-1.4 eV, however, the luminescence, which decays in ∼300 fs, cannot be reproduced by this model. These results indicate that the carrier system is not completely thermalized in ∼300 fs. We also show the importance of the carrier-doping effect induced by the substrate and surrounding environment in the carrier cooling dynamics and the predominance of optical phonons over acoustic phonons in the carrier-phonon interactions even at a temperature of ∼400 K.

    Original languageEnglish
    Pages (from-to)2335-2343
    Number of pages9
    JournalACS nano
    Volume7
    Issue number3
    DOIs
    Publication statusPublished - Mar 26 2013

    All Science Journal Classification (ASJC) codes

    • Materials Science(all)
    • Engineering(all)
    • Physics and Astronomy(all)

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    Koyama, T., Ito, Y., Yoshida, K., Tsuji, M., Ago, H., Kishida, H., & Nakamura, A. (2013). Near-infrared photoluminescence in the femtosecond time region in monolayer graphene on SiO2. ACS nano, 7(3), 2335-2343. https://doi.org/10.1021/nn305558r