Abstract Presented are the results of comparative study of the decay kinetics for luminescence in the visible (350 ÷ 700 nm) and infrared (1000 ÷ 1900 nm) spectral regions, which is excited in CsI:Tl crystals by a pulsed electron beam (Еm = 250 keV, t1/2 = 15 ns, j= 8 mJ/cm2). The infrared luminescence is assumed to be caused by radiative transition from the excited 62P3/2 state into the ground 62P1/2 state of Tl0 center. The decay kinetics of this luminescence at temperatures within 77 ÷ 450 К range is found to have two pronounced stages. One of them is exponential with a time constant characteristic for the given temperature and independent of Tl concentration within 0.018 ÷ 0.43 mass% range. The other stage has the same decay kinetics as that of the visible luminescence measured under the same conditions. In terms Tl0-Vk recombination giving rise to Tl-perturbed excitons, the visible luminescence arise due to disintegration of [(Tl0)*,Vk] complexes, where Tl0 center has the populated ψ sub-level of the 62P3/2 excited state. The exponential nature and rather long duration of the visible luminescence decay (τ = 700 ns) at room temperature are determined by the lifetime of Tl0 center in the excited metastable state.

中文翻译：

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CsI:Tl晶体中电子束诱导的红外和可见光的动力学特性

摘要 介绍了在可见光 (350 ÷ 700 nm) 和红外 (1000 ÷ 1900 nm) 光谱区的发光衰变动力学的比较研究结果，其在 CsI:Tl 晶体中被脉冲电子束激发 (Еm = 250 keV，t1/2 = 15 ns，j= 8 mJ/cm2）。假设红外发光是由从激发态 62P3/2 态到 Tl0 中心的基态 62P1/2 态的辐射跃迁引起的。发现这种发光在 77 ÷ 450 К 范围内的温度下的衰变动力学有两个明显的阶段。其中之一是具有给定温度的时间常数特性的指数，并且与 0.018 ÷ 0.43 质量％范围内的 Tl 浓度无关。另一个阶段与在相同条件下测量的可见光具有相同的衰减动力学。就引起 Tl 扰动激子的 Tl0-Vk 重组而言，可见发光是由于 [(Tl0)*,Vk] 复合物的分解而产生的，其中 Tl0 中心具有 62P3/2 激发态的 ψ 子能级。室温下可见光衰变 (τ = 700 ns) 的指数性质和相当长的持续时间由激发亚稳态中 Tl0 中心的寿命决定。