Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
1483961 | Journal of Non-Crystalline Solids | 2009 | 4 Pages |
Abstract
Two variants of the surface-nonbridging oxygen hole center, (Si–O)3Si–O• and (Si–O)2(H–O)Si–O•, stabilized in porous films of silica nano-particles were investigated by time resolved luminescence excited in the visible and UV spectral range by a tunable laser system. Both defects emit a photoluminescence around 2.0 eV with an excitation spectrum evidencing two maxima at 2.0 and 4.8 eV, this emission decreases by a factor ∼2 on increasing the temperature from 8 up to 290 K. However, the different local structure influences the emission lineshape, the quantum yield and the decay lifetime. Such peculiarities are discussed on the basis of the symmetry properties of these defects.
Related Topics
Physical Sciences and Engineering
Materials Science
Ceramics and Composites
Authors
L. Vaccaro, M. Cannas, V. Radzig,