Shi Yang-Fang, Wei Wen-Bo, Wu Xin-Tao, Lin Hua, Zhu Qi-Long
Fujian Science & Technology Innovation Laboratory for Optoelectronic Information of China, Fuzhou, Fujian 350108, China.
Dalton Trans. 2021 Mar 28;50(12):4112-4118. doi: 10.1039/d1dt00222h. Epub 2021 Mar 17.
Currently, non-centrosymmetric oxychalcogenides, a class of newly developed heteroanionic compounds, have emerged as promising candidates for IR nonlinear optical (NLO) materials due to the fact that they can combine the impressive second-harmonic generation (SHG) responses of chalcogenides with the wide energy gaps of oxides. Moreover, multiple combinations of chalcogens and the oxygen element would, in principle, lead to more new frequency-doubling building units, enabling the extensive seeking and design of new NLO-active oxychalcogenides. In this Frontiers article, the recent developments of oxychalcogenides as IR-NLO candidates are summarized. These materials can be grouped into three types in terms of their structural dimensions: (i) two-dimensional layered CaZnOS, SrZnOS, SrGaOS, SrCdSbOS and SrPbSbOSe; (ii) one-dimensional chain-typed AEGeOQ (AE = Sr and Ba; Q = S and Se); and (iii) zero-dimensional molecular SrGeOSe and α-NaPOS. We discuss the rich coordination environment of mixed-anion frequency-doubling building units focusing on the correlations between their non-centrosymmetric structures and NLO properties, as well as their synthetic methods. Finally, the present challenges and future perspectives in this field are also proposed.
目前，非中心对称硫属氧化物作为一类新开发的杂阴离子化合物，已成为红外非线性光学（NLO）材料的有潜力候选者，因为它们能将硫属化物令人印象深刻的二次谐波产生（SHG）响应与氧化物的宽能隙结合起来。此外，硫属元素与氧元素的多种组合原则上会导致更多新的倍频结构单元，从而能够广泛地寻找和设计新的具有NLO活性的硫属氧化物。在这篇前沿文章中，总结了硫属氧化物作为红外NLO候选材料的最新进展。这些材料根据其结构维度可分为三种类型：（i）二维层状的CaZnOS、SrZnOS、SrGaOS、SrCdSbOS和SrPbSbOSe；（ii）一维链状的AEGeOQ（AE = Sr和Ba；Q = S和Se）；以及（iii）零维分子SrGeOSe和α-NaPOS。我们讨论了混合阴离子倍频结构单元丰富的配位环境，重点关注它们的非中心对称结构与NLO性质之间的相关性以及它们的合成方法。最后，还提出了该领域目前面临的挑战和未来前景。
