Visible photoluminescence from Si clusters in γ-irradiated amorphous SiO2

Hiroyuki Nishikaw, Eiki Watanabe, Daisuke Ito, Yuryo Sakurai, Kaya Nagasawa, Yoshimichi Ohki

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    Visible photoluminescence (PL) bands around 2 eV were studied in 60Co γ-irradiated (dose<1 MGy) oxygen-deficient-type amorphous SiO2 (a-SiO2) excited by 2-4 eV photons. In addition to the well-known 1.9 eV PL band due to nonbridging oxygen note centers, another PL band was observed at 2.2 eV when excited by 3.8 eV photons. The intensity of the 2.2 eV band increases with decreasing oxygen partial pressure during the sample preparation. Electron-spin-resoaance measurements show that the intensity of the 2.2 eV band is correlated with the concentration of the E'δ center. a paramagnetic state of a cluster of silicons. After much higher δ irradiation with a dose up to 10 MGy, a new PL band was induced at 1.75 eV under excitation by 2.5 eV photons, as well as the 1.9 and 2.2 eV PL bands. By comparing its spectral shape and excitation energy with known PL band in Si-implanted a-SiO2, it is suggested that the 1.75 eV band is associated with Si nanocrystals formed from Si clusters in a-SiO2 by the high-dose γ irradiation

    Original languageEnglish
    Pages (from-to)3513-3517
    Number of pages5
    JournalJournal of Applied Physics
    Issue number6
    Publication statusPublished - 1996 Sep 15


    ASJC Scopus subject areas

    • Physics and Astronomy(all)
    • Physics and Astronomy (miscellaneous)

    Cite this

    Nishikaw, H., Watanabe, E., Ito, D., Sakurai, Y., Nagasawa, K., & Ohki, Y. (1996). Visible photoluminescence from Si clusters in γ-irradiated amorphous SiO2 Journal of Applied Physics, 80(6), 3513-3517.