Physics – Condensed Matter – Disordered Systems and Neural Networks
Scientific paper
2008-09-10
Physics
Condensed Matter
Disordered Systems and Neural Networks
Scientific paper
10.1088/0953-8984/21/11/115803
We report time-resolved photoluminescence spectra of point defects in amorphous silicon dioxide (silica), in particular the decay kinetics of the emission signals of extrinsic Oxygen Deficient Centres of the second type from singlet and directly-excited triplet states are measured and used as a probe of structural inhomogeneity. Luminescence activity in sapphire ($\alpha$-Al$_2$O$_3$) is studied as well and used as a model system to compare the optical properties of defects in silica with those of defects embedded in a crystalline matrix. Only for defects in silica, we observe a variation of the decay lifetimes with emission energy and a time dependence of the first moment of the emission bands. These features are analyzed within a theoretical model with explicit hypothesis about the effect introduced by the disorder of vitreous systems. Separate estimations of the homogenous and inhomogeneous contributions to the measured emission linewidth are obtained: it is found that inhomogeneous effects strongly condition both the triplet and singlet luminescence activities of oxygen deficient centres in silica, although the degree of inhomogeneity of the triplet emission turns out to be lower than that of the singlet emission. Inhomogeneous effects appear to be negligible in sapphire.
Boscaino Roberto
Cannas Marco
D'Amico Michele
Leone Maurizio
Messina Fabrizio
No associations
LandOfFree
Photoluminescence dispersion as a probe of structural inhomogeneity in silica does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Photoluminescence dispersion as a probe of structural inhomogeneity in silica, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Photoluminescence dispersion as a probe of structural inhomogeneity in silica will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-161062