Afterglow suppression and non-radiative charge-transfer in CsI:Tl,Sm
Afterglow suppression and non-radiative charge-transfer in CsI:Tl,Sm
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DOI：
10.1109/tns.2008.922833
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发表时间：
2008-06-01
影响因子：
1.8
通讯作者：
Nagarkar, V. V.
中科院分区：
文献类型：
--
作者：
Bartram, Ralph H.;Kappers, Lawrence A.;Nagarkar, V. V.
研究发现，共掺杂 CsI:Tl 中的余辉抑制效果在 CsI:Tl,Sm 中比在 CsI:Tl,Eu 中更有效一个数量级。速率方程预测，钐共掺杂会引入深电子陷阱。有效地清除与铊相关的浅陷阱中的电子，从而抑制数十毫秒时域内的余辉。此外，结合的放射发光和热致发光实验表明，钐释放的电子与捕获的空穴以非辐射方式复合，从而提供了抑制磁滞现象的机制。从头算量子化学计算支持以下结论：CsI:Tl,Sm 中的非辐射电荷转移跃迁是通过接地构型中 Sm2+ 的低能 D-5(J) 激发态的存在而实现的。
Suppression of afterglow in co-doped CsI:Tl is found to be an order of magnitude more effective in CsI:Tl,Sm than in CsI:Tl,Eu. Rate equations predict that deep electron traps introduced by co-doping with samarium. effectively scavenge electrons from shallow traps associated with thallium, thus suppressing afterglow in the time domain of tens of milliseconds. In addition, combined radioluminescence and thermoluminescence experiments suggest that electrons released by samarium recombine non-radiatively with trapped holes, thus providing a mechanism for suppression of hysteresis. Ab initio quantum chemistry calculations support the conclusion that non-radiative charge-transfer transitions in CsI:Tl,Sm are enabled by the presence of low-energy D-5(J) excited states of Sm2+ within the ground configuration.