The photo-luminescence features of Ge-oxygen defect centers in a 100nm thick Ge-doped silica film on a pure silica substrate were investigated by looking at the emission spectra and time decay detected under synchrotron radiation excitation in the 10-300 K temperature range. This center exhibits two luminescence bands centered at 4.3eV and 3.2eV associated with its de-excitation from singlet (S1) and triplet (T1) states, respectively, that are linked by an intersystem crossing process. The comparison with results obtained from a bulk Ge-doped silica sample evidences that the efficiency of the intersystem crossing rate depends on the properties of the matrix embedding the Ge-oxygen defect centers, being more effective in the film than in the bulk counterpart.
@article{arxiv.cond-mat/0703062,
title = {Optical properties of Ge-oxygen defect center embedded in silica films},
author = {F. Messina and S. Agnello and R. Boscaino and M. Cannas and S. Grandi and E. Quartarone},
journal= {arXiv preprint arXiv:cond-mat/0703062},
year = {2009}
}
Comments
10 pages, 3 figures, in press on J. Non cryst. solids (2007)