Gieszczyk Wojciech, Marczewska Barbara, Kłosowski Mariusz, Mrozik Anna, Bilski Paweł, Sas-Bieniarz Anna, Goj Paweł, Stoch Paweł
Institute of Nuclear Physics Polish Academy of Sciences, Radzikowskiego 152, PL31342 Krakow, Poland.
AGH University of Science and Technology, Mickiewicza 30, PL30059 Krakow, Poland.
Materials (Basel). 2019 Sep 5;12(18):2861. doi: 10.3390/ma12182861.
We investigated the influence of terbium and thulium trivalent rare-earth (RE) ions co-doping on the luminescent properties enhancement of LiMgPO (LMP) crystal host. The studied crystals were grown from the melt by micro-pulling-down (MPD) technique. Luminescent properties of the obtained crystals were investigated by thermoluminescence (TL) method. The most favorable properties and the highest luminescence enhancement were measured for Tb and Tm double doped crystals. A similar luminescence level can be also obtained for Tm, B co-doped samples. In this case, however, the low-temperature TL components have a significant contribution. The measured luminescent spectra showed a typical emission of Tb and Tm ions of an opposite trapping nature, namely the holes and electron-trapping sites, respectively. The most prominent transitions of D → F (550 nm for Tb) and D → F (450 nm for Tm) were observed. It was also found that Tb and Tm emissions show temperature dependence in the case of double doped LMP crystal sample, which was not visible in the case of the samples doped with a single RE dopant. At a low temperature range (up to around 290 °C) Tm emission was dominant. At higher temperatures, the electrons occupying Tm sites started to be released giving rise to emissions from Tb-related recombination centers, and emissions from Tm centers simultaneously decreased. At the highest temperatures, emission took place from Tb recombination centers, but only from deeper D level-related traps which had not been emptied at a lower temperature range.
我们研究了铽（Tb）和铥（Tm）三价稀土（RE）离子共掺杂对LiMgPO（LMP）晶体基质发光性能增强的影响。所研究的晶体通过微下拉（MPD）技术从熔体中生长。通过热释光（TL）方法研究了所得晶体的发光性能。对于Tb和Tm双掺杂晶体，测量到了最有利的性能和最高的发光增强。对于Tm、B共掺杂样品也可以获得类似的发光水平。然而，在这种情况下，低温TL成分有显著贡献。测量的发光光谱显示了Tb和Tm离子典型的发射，分别具有相反的俘获性质，即空穴俘获和电子俘获位点。观察到了最显著的D→F跃迁（Tb为550nm）和D→F跃迁（Tm为450nm）。还发现，在双掺杂LMP晶体样品中，Tb和Tm发射表现出温度依赖性，而在单稀土掺杂样品中则不明显。在低温范围（高达约290°C），Tm发射占主导。在较高温度下，占据Tm位点的电子开始释放，从而产生与Tb相关的复合中心的发射，同时Tm中心的发射减少。在最高温度下，发射发生在Tb复合中心，但仅来自在较低温度范围内未被清空的更深的与D能级相关的陷阱。
