Chen Man-Man, Zhou Sheng-Hua, Wei Wenbo, 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 350002, China.
Fujian Science & Technology Innovation Laboratory for Optoelectronic Information of China, Fuzhou, Fujian 350108, China.
Inorg Chem. 2021 Jul 5;60(13):10038-10046. doi: 10.1021/acs.inorgchem.1c01359. Epub 2021 Jun 17.
Despite the fact that nonlinear optical (NLO) crystals such as AgGaS and AgGaSe have been widely used in the infrared (IR) range due to their large second harmonic generation (SHG) coefficients and wide range of IR transparency windows, the small laser-induced damage threshold (LIDT) remains a great issue hindering their high-power applications. Herein, three noncentrosymmetric (NCS) chalcogenides AZnGaSe (A = K, Rb, or Cs) are successfully obtained through an appropriate flux method after the extensive design and synthesis of the A/Zn/Ga/Q system. Single-crystal X-ray diffraction data demonstrate that they adopt trigonal space group 3 (No. 146) with three-dimensional diamond-like frameworks composed of [MSe] layers (M = Zn or Ga) stacking in the same direction and filled by charge-balancing A cations. Noticeably, they all exhibit strong powder SHG responses (2.8-3.7 × AgGaS) and amazing LIDTs (19.2-23.4 × AgGaS). In addition, theoretical calculations are performed to further determine the relationship between NCS structures and NLO properties. This work provides effective solutions for overcoming the trade-off between strong SHG and high LIDT in IR-NLO materials.
尽管诸如AgGaS和AgGaSe之类的非线性光学（NLO）晶体由于其大的二次谐波产生（SHG）系数和宽的红外（IR）透明窗口范围而在红外范围内得到了广泛应用，但小的激光诱导损伤阈值（LIDT）仍然是阻碍其高功率应用的一个重大问题。在此，在对A/Zn/Ga/Q体系进行广泛设计和合成之后，通过适当的助熔剂法成功获得了三种非中心对称（NCS）硫族化物AZnGaSe（A = K、Rb或Cs）。单晶X射线衍射数据表明，它们采用三方空间群3（编号146），具有由[MSe]层（M = Zn或Ga）沿相同方向堆叠并由电荷平衡的A阳离子填充而成的三维类金刚石骨架。值得注意的是，它们都表现出强烈的粉末SHG响应（2.8 - 3.7×AgGaS）和惊人的LIDT（19.2 - 23.4×AgGaS）。此外，进行了理论计算以进一步确定NCS结构与NLO性质之间的关系。这项工作为克服红外NLO材料中强SHG与高LIDT之间的权衡提供了有效的解决方案。
