Xiao Yang, Luo Qiang, Ju Meng, Yeung Yauyuen
School of Sciences, Southwest Petroleum University, Chengdu 610500, China.
School of Physical Science and Technology, Southwest University, Chongqing 400715, China.
J Phys Chem A. 2024 Oct 24;128(42):9107-9113. doi: 10.1021/acs.jpca.4c03698. Epub 2024 Oct 10.
Praseodymium (Pr)-doped LiYF nanophosphors have garnered significant interest for their potential applications in lasers, phosphors, and quantum memories. However, there remains a lack of comprehensive research on the local coordination environment and luminescence spectroscopy of Pr:LiYF nanocrystals. This study presents the first investigation of the ground-state structure of Pr:LiYF crystals by employing the crystal structure prediction method, and a [PrF] ligand complex with local symmetry is determined. The complete energy levels of the Pr ions in LiYF nanocrystals are unveiled by using our newly developed well-established parametrization matrix diagonalization method. A novel set of free-ion and crystal-field parameters is derived through a good simulation with 45 experimental energy levels. Many of the emissions of Pr-doped LiYF are successfully reproduced based on Judd-Ofelt theory, and these transitions are comparable to the experimental ones. Moreover, two new prominent emission bands with their peaks at 675 and 849 nm originating from I → F and I → G transitions, respectively, are predicted by us for the first time. This study could provide a feasible method to search for practical laser transition channels of solid-state lasers based on Pr: LiYF nanophosphors.
掺镨（Pr）的LiYF纳米磷光体因其在激光、磷光体和量子存储器中的潜在应用而备受关注。然而，对于Pr:LiYF纳米晶体的局部配位环境和发光光谱仍缺乏全面的研究。本研究首次采用晶体结构预测方法对Pr:LiYF晶体的基态结构进行了研究，并确定了具有局部对称性的[PrF]配体络合物。通过使用我们新开发的成熟的参数化矩阵对角化方法，揭示了LiYF纳米晶体中Pr离子的完整能级。通过与45个实验能级的良好模拟，得出了一组新的自由离子和晶体场参数。基于Judd-Ofelt理论成功再现了掺Pr的LiYF的许多发射，并且这些跃迁与实验结果相当。此外，我们首次预测了两个新的突出发射带，其峰值分别位于675和849 nm，分别源自I→F和I→G跃迁。本研究可为寻找基于Pr:LiYF纳米磷光体的固态激光器的实际激光跃迁通道提供一种可行的方法。
