Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
5403469 | Journal of Luminescence | 2008 | 7 Pages |
Abstract
The absorption and luminescence properties of CsI(Tl) crystals colored by irradiation are studied by the method of the time-resolved spectroscopy. The scheme of the electron transitions in CsI(Tl) crystal is suggested to explain the appearance of the color centers under exposure to the near-UV light. It is established that either of the two types activator color centers holds the charge carrier with opposite sign. The model of the hole Tl2+vcâ activator color center is suggested. According to the model the positive charge of Tl2+ ion is compensated by the negative charge of a close cation vacancy vcâ. The color center emission reveals in the cathode-luminescence spectrum of the colored CsI(Tl) crystal. The high-dose irradiation of CsI(Tl) crystal results in the reduction of the decay time of the near-thallium self-trapped excitons (STE) emission. The decay kinetics of Tl2+vcâ emission contains the time components typical for the decay kinetics of near-thallium STE emission. The reason of the observed effects is the energy transfer from the near-thallium STE excitons to the color centers via the inductive-resonant mechanism.
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Authors
V. Yakovlev, A. Meleshko, L. Trefilova,