Yue Qing-Gang, Wei Wen-Bo, Chen Hong, Wu Xin-Tao, Lin Hua, Zhu Qi-Long
State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian 350002, China.
Dalton Trans. 2020 Oct 27;49(41):14338-14343. doi: 10.1039/d0dt02971h.
Non-centrosymmetric metal chalcogenides such as AgGaS2 and AgGaSe2 are two of the commercial nonlinear optical (NLO) crystals widely used in the infrared (IR) region. Nevertheless, the inherent incompatibility between the wide energy gap (Eg) and large second-harmonic generation (SHG) efficiency (dij) hinders their high-power laser applications. Recently, the development of salt-inclusion chalcogenides with non-centrosymmetric structures has attracted more and more attention and interest owing to their intensive potential applications originating from their wide Eg, strong dij, ultrahigh laser-induced damage thresholds (LIDTs) and large IR transmission range. In this frontier paper, we review the recent progress of salt-inclusion chalcogenides (including 28 related compounds) as favourable candidates for IR-NLO materials, which can be divided into 3 types according to their chemical compositions and structural characteristics: (i) the [RaXb][GanQ2n] type and its derivatives, (ii) [NaBa4Cl][Ge3S10] and its derivatives, and (iii) the [A3X][MB12(MQ4)3] type. The relationships between the non-centrosymmetric structures and NLO properties of these 3 types of compounds are summarized and briefly remarked. In addition, the present challenges of creating new IR-NLO salt-inclusion chalcogenides and future perspectives in this field are discussed.
非中心对称金属硫族化合物，如AgGaS2和AgGaSe2，是广泛应用于红外（IR）区域的两种商业非线性光学（NLO）晶体。然而，宽能隙（Eg）与大二阶谐波产生（SHG）效率（dij）之间固有的不相容性阻碍了它们在高功率激光领域的应用。近年来，具有非中心对称结构的包盐硫族化合物因其宽Eg、强dij、超高激光诱导损伤阈值（LIDTs）和大红外传输范围等潜在应用而受到越来越多的关注。在这篇前沿论文中，我们综述了包盐硫族化合物（包括28种相关化合物）作为红外NLO材料的有利候选物的最新进展，根据其化学成分和结构特征可分为3类：（i）[RaXb][GanQ2n]型及其衍生物；（ii）[NaBa4Cl][Ge3S10]及其衍生物；（iii）[A3X][MB12(MQ4)3]型。总结并简要评述了这3类化合物的非中心对称结构与NLO性质之间的关系。此外，还讨论了制备新型红外NLO包盐硫族化合物目前面临的挑战以及该领域的未来前景。
