STATIONARY AND TIME-DEPENDENT PL EMISSION OF V-SIO2 IN THE UV RANGE

The photoluminescence in vitreous-SiO2 in the 4.0 to 4.5 eV region has been investigated by exciting with UV and vacuum-UV photons. Two emis sion bands, alpha(E) and alpha(I), centered at 4.26 and 4.42 eV respec tively, are detected. They have distinct features: alpha(E) has an exc itation profile extending from 7.0 to 8.2 eV and decays with a lifetim e of 5.5 ns; alpha(I), has an excitation maximum at 6.8 eV and a decay time of 4.1 ns. The centers responsible for these optical activities are discussed, also on the basis of their behaviour under gamma-irradi ation. (C) 1997 Elsevier Science B.V.