Effect of deep traps on the optical properties of Tb3+ doped sol-gel silica

In this study we investigate the role of traps on radio- and photo-luminescence properties of terbium doped silica. The investigation is motivated by the promising characteristics of rare-earth doped silica obtained by the sol-gel technique as scintillating material. We focus on those phenomena that can be responsible for problematic properties such as the increase of radio-luminescence sensitivity following repeated irradiations. A set of terbium doped silica with different terbium concentrations (0.03 mol%, 0.1 mol% and 10 mol%) prepared by the sol-gel technique and densified at 1050 °C in oxidizing atmosphere has been considered. The effect of a post-densification rapid thermal treatment on the RL and PL properties has also been investigated. This treatment improved the scintillation characteristics of the samples reducing their RL instability under prolonged irradiation. (© 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)