The cause of a green photoluminescence at about 2.25eV in silica glass was studied by using electron spin resonance techniques. The 2.25eV photoluminescence band (lifetime of about 300ns, full-width at half-maximum of about 0.2eV) appeared to be strong in γ-irradiated high O-content silica glass; thus suggesting that this photoluminescence was associated with a large surplus of O states in the glass. An isochronal annealing investigation was made of the correlation between the 2.25eV photoluminescence band and the peroxy radical. Peroxy radicals were formed of the O3=Si-O-O▪ bond and the small so-called peroxy radical bond in silica glass. On the basis of the annealing characteristics of the 2.25eV photoluminescence band and the peroxy radical, it was suggested that the photoluminescence band was associated with a surplus of O defects formed by the small peroxy radical, rather than the O3=Si-O-O▪ bond.

Correlation between the Green Photoluminescence Band and the Peroxy Radical in γ-Irradiated Silica Glass. Y.Sakurai, K.Nagasawa: Journal of Applied Physics, 2000, 88[1], 168-71