Abstract A single crystal of TlAlF4 is grown by a self-seeded vertical Bridgman-method. The measured powder X-ray diffraction pattern is compared with the standard JCPDS pattern and found to be in good agreement. The crystal structure and cell parameters are calculated and refined by Rietveld refinement analysis. The optical absorption spectrum is measured and the characteristic spectral properties of Tl + bands are studied. The temperature dependent photoluminescence (PL) excitation and emission spectra are measured in the temperature range of 10–300 K. The doublet structure of Tl + ion A excitation bands (A1, A2) are observed and correlated with absorption bands. The excitation under both bands yields the same broad emission band in the range of 330–500 nm with the maximum peak at around 390 nm in room temperature. At low temperatures, this emission band is well resolved into two emission bands with maximum at 371 and 404 nm for separate excitations of 227 and 236 nm, respectively. The schematic configuration coordinate energy level diagram for emission of Tl+ ion is also proposed. Low temperature thermally stimulated luminescence (TSL) were carried out and analysed the trap depth (E) and frequency factor values. The mechanisms of the processes, responsible for the emission band and formation of defects pairs of the type of Tl0–Vk center have been discussed in detail manner.

中文翻译：

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TlAlF4晶体的发光特性

摘要 TlAlF4 单晶是通过自种垂直布里奇曼方法生长的。将测得的粉末 X 射线衍射图与标准 JCPDS 图进行比较，发现两者吻合良好。晶体结构和晶胞参数通过 Rietveld 细化分析计算和细化。测量了光吸收光谱并研究了 Tl + 波段的特征光谱特性。温度相关的光致发光 (PL) 激发和发射光谱在 10–300 K 的温度范围内测量。观察到 Tl + 离子 A 激发带 (A1, A2) 的双峰结构并与吸收带相关联。两个波段下的激发在 330-500 nm 范围内产生相同的宽发射带，最大峰值在室温下 390 nm 左右。在低温下，该发射带很好地分解为两个发射带，最大值分别为 371 和 404 nm，分别用于 227 和 236 nm 的单独激发。还提出了Tl+离子发射的示意构型坐标能级图。进行低温热激发发光 (TSL) 并分析陷阱深度 (E) 和频率因子值。已经详细讨论了导致发射带和 Tl0-Vk 中心类型缺陷对形成的过程机制。进行低温热激发发光 (TSL) 并分析陷阱深度 (E) 和频率因子值。已经详细讨论了导致发射带和 Tl0-Vk 中心类型缺陷对形成的过程机制。进行低温热激发发光 (TSL) 并分析陷阱深度 (E) 和频率因子值。已经详细讨论了导致发射带和 Tl0-Vk 中心类型缺陷对形成的过程机制。