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RESEARCH PRODUCT

Temperature dependence of luminescence decay in Sn-doped silica

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We report an experimental study on the temperature dependence, in the range 18-300 K, of the decay kinetics of the emission at 4.1 eV from the first excited electronic state of oxygen deficient centers in a 2000 ppm Sn-doped sol-gel silica. At low temperature, this luminescence decays exponentially with a lifetime of 8.4 ns, whereas, on increasing the temperature, the time decay decreases and cannot be fitted with an exponential function. These results are expected if there is a competition between the radiative and the thermally activated intersystem-crossing decay channels toward the associated triplet state. The comparison with previous data in pure oxygen-deficient and Ge-doped silica gives new insight on the effect of the host-matrix dynamics on the electronic properties of this type of point defect. © 2005 Elsevier B.V. All rights reserved.