Li Junjiang, Zhao Huanke, Zhang Xinyuan, Gong Pifu, Lin Zheshuai, Wu Yicheng
Tianjin Key Laboratory of Functional Crystal Materials, Institute of Functional Crystals, Tianjin University of Technology, Tianjin 300384, China.
Functional Crystals Lab, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing 100190, China.
Inorg Chem. 2024 Oct 21;63(42):19916-19923. doi: 10.1021/acs.inorgchem.4c03372. Epub 2024 Oct 8.
The band gap is one of the significant parameters for nonlinear optical (NLO) materials, which is the key factor in their application band in laser technology. This study reports the synthesis of two rare-earth selenite NLO crystals, namely, RE(HSeO)(SeO)(HO)·(HO) (RE = Y, Gd), utilizing the hydrothermal technique. The two compounds are isostructural, and both belong to the orthorhombic chiral space group of 222 and possess three-dimensional structures consisting of two-dimensional rare-earth selenite layers connected by hydrogen bonds (O-H··O). These two compounds exhibit a moderate second harmonic generation intensity of 0.5/0.8 × KDP and wide energy band gaps reaching 4.8 eV. Comprehensive density functional theory analyses based on first-principles were carried out to unravel the relationship between the structural and corresponding properties. This work provides an approach for band gap enlargement in rare-earth selenite systems and is beneficial to the design of future NLO materials.
带隙是非线性光学（NLO）材料的重要参数之一，是其在激光技术应用波段中的关键因素。本研究报道了利用水热技术合成两种稀土亚硒酸盐NLO晶体，即RE(HSeO)(SeO)(HO)·(HO)（RE = Y，Gd）。这两种化合物同构，均属于正交手性空间群222，具有由通过氢键（O-H··O）连接的二维稀土亚硒酸盐层组成的三维结构。这两种化合物表现出0.5/0.8×KDP的中等二次谐波产生强度和高达4.8 eV的宽能带隙。基于第一性原理进行了综合密度泛函理论分析，以揭示结构与相应性质之间的关系。这项工作为稀土亚硒酸盐体系中的带隙扩大提供了一种方法，有利于未来NLO材料的设计。
