Photoluminescence of Se-related oxygen deficient center in ion-implanted silica films

The results of low-temperature time-resolved photoluminescence (PL) investigation of thin SiO2 films implanted with Se+ ions are presented. The films demonstrate an intensive PL band in the violet spectral region, which is attributed to the triplet luminescence of a new variant of selenium-related oxygen deficient center (ODC). The main peculiarity of the defect energy structure is the inefficient direct optical excitation. Comparison with spectral characteristics of isoelectronic Si-, Ge- and SnODCs show that the difference in electronic properties of the new center is related to ion size factor. It was established that the dominating triplet PL excitation under VUV light irradiation is related to the energy transfer from SiO2 excitons. A possible model of Se-related ODC is considered.