Ju Meng, Liang Hao, Zhu Yongsheng, Yeung Yau-Yuen, Yuan Hongkuan, Zhong Mingmin, Dai Wei, Lu Cheng
School of Physical Science and Technology, Southwest University, Chongqing 400715, China.
School of Science, Southwest University of Science and Technology, Mianyang 621010, China.
Inorg Chem. 2021 Mar 19. doi: 10.1021/acs.inorgchem.1c00021.
Trivalent praseodymium (Pr)-doped materials have been extensively used in high-resolution laser spectroscopy, owing to their outstanding conversion efficiencies of plentiful transitions in the visible laser region. However, to clarify the microstructure and energy transfer mechanism of Pr-doped host crystals is a challenging topic. In this work, the stable structures of Pr-doped yttrium orthoaluminate (YAlO) have been widely searched based on the CALYPSO method. A novel monoclinic structure with the group symmetry is successfully identified. The Pr impurity can precisely occupy the Y position and get incorporated into the YAlO (YAP) host crystal with a Pr concentration of 6.25%. The result of the electronic band structure reveals a 3.62 eV band gap, which suggests a semiconductor character of YAP:Pr. Using our developed well-established parametrization matrix diagonalization (WEPMD) method, we have systematically analyzed the energy level scheme and proposed a set of newly improved parameters. Additionally, the energy transfer mechanism of YAP:Pr is clarified by deciphering the numerical electric dipole and magnetic dipole transitions. The popular red emission at 653 nm is assigned to the transition P → F, while the transition P → H with a large branching ratio is predicted to be a good laser channel. Many promising emission lines for laser actions are also obtained in the visible light region. Our results not only provide important insights into the energy transfer mechanisms of rare-earth ion-doped materials but also pave the way for the implementation of new types of laser devices.
三价镨（Pr）掺杂材料因其在可见激光区域丰富跃迁的出色转换效率而被广泛应用于高分辨率激光光谱学。然而，阐明Pr掺杂基质晶体的微观结构和能量转移机制是一个具有挑战性的课题。在这项工作中，基于CALYPSO方法广泛搜索了Pr掺杂钇铝酸盐（YAlO）的稳定结构。成功识别出一种具有 群对称性的新型单斜结构。Pr杂质能够精确占据Y位置，并以6.25%的Pr浓度掺入YAlO（YAP）基质晶体中。电子能带结构结果显示带隙为3.62 eV，这表明YAP:Pr具有半导体特性。使用我们开发的成熟的参数化矩阵对角化（WEPMD）方法，我们系统地分析了能级图并提出了一组新改进的参数。此外，通过解析数值电偶极和磁偶极跃迁阐明了YAP:Pr的能量转移机制。653 nm处常见的红色发射归因于P→F跃迁，而具有大分支比的P→H跃迁预计是一个良好的激光通道。在可见光区域还获得了许多有前景的激光作用发射线。我们的结果不仅为稀土离子掺杂材料的能量转移机制提供了重要见解，也为新型激光器件的实现铺平了道路。
