Li4HgSn2Se7: The First Second-Order Nonlinear Optical-Active Selenide in the I4–II–IV2–VI7 Diamond-like Family

• DOI: 10.1021/acs.cgd.9b01074
• Publication Date: 2019-09-09T15:57:22Z
• Authors: Yangwu Guo; Fei Liang; Zhuang Li; Wenhao Xing; Zheshuai Lin; Jiyong Yao; Yicheng Wu
• Keywords: Tetrahedron; Selenide; Cadmium selenide

A new infrared nonlinear optical material with diamond-like structures, Li4HgSn2Se7, was synthesized by the traditional high-temperature solid-state method. It crystallizes in non-centrosymmetric group Cc all LiSe4, HgSe4, and SnSe4 tetrahedra aligned an additive manner. This exhibits large second harmonic generation (SHG) about 3.6 times that of benchmark AgGaS2 phase-matching behavior. Detailed structural analysis calculations reveal (HgSe4) (SnSe4) are main contributors for its strong nonlinearity. Moreover, electronic states distinct contribution to SHG different Se species also elucidated.