Visible photoluminescence from Si clusters in γ-irradiated amorphous SiO2

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

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

122 Citations (Scopus)


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 Sept 15

ASJC Scopus subject areas

  • Physics and Astronomy(all)


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