Guo Yangwu, Li Xiaoshuang, Feng Kai, Li Chao, Zhou Molin, Wu Yicheng, Yao Jiyong
Center for Crystal Research and Development, Key Laboratory of Functional Crystals and Laser Technology, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing, 100190, P. R. China.
University of Chinese Academy of Sciences, Beijing, 100049, P. R. China.
Chem Asian J. 2018 Apr 4;13(7):871-876. doi: 10.1002/asia.201800090. Epub 2018 Mar 7.
Two new selenides with diamond-like structures, Li Cd Ge Se and Li Cd Sn Se , were synthesized by using a conventional high-temperature solid-state reaction method. They crystallize in the space group Pna2 (no. 33) of the orthorhombic system. Their three-dimensional frameworks consist of corner-sharing LiSe , CdSe , and MSe (M=Ge, Sn) tetrahedra. These two compounds exhibit strong powder second-harmonic generation responses that are about 1.2 and 2.5 times that of the benchmark AgGaS at a laser wavelength of λ=2.09 μm, and also demonstrate type I phase-matchable behavior. The optical bandgaps were determined to be 2.18 and 1.95 eV for Li Cd Ge Se and Li Cd Sn Se , respectively. Furthermore, these two materials exhibit congruent melting behavior at rather low temperatures of 985 and 1060 K, respectively, which makes bulk single crystal growth by using the Bridgman-Stockbarger method possible. Our study indicates that these two materials show advantages over the traditional IR NLO material CdSe and are promising for practical applications.
通过传统高温固态反应法合成了两种具有类金刚石结构的新型硒化物LiCdGeSe和LiCdSnSe。它们结晶于正交晶系的Pna2（编号33）空间群。其三维骨架由共用顶点的LiSe、CdSe和MSe（M = Ge、Sn）四面体组成。这两种化合物在激光波长λ = 2.09μm时表现出强烈的粉末二次谐波产生响应，分别约为基准AgGaS的1.2倍和2.5倍，并且还表现出I型相位匹配行为。LiCdGeSe和LiCdSnSe的光学带隙分别测定为2.18和1.95 eV。此外，这两种材料分别在985和1060 K的相当低的温度下表现出一致熔化行为，这使得通过布里奇曼-斯托克巴格法生长块状单晶成为可能。我们的研究表明，这两种材料相对于传统红外非线性光学材料CdSe具有优势，并且在实际应用中很有前景。
