Highly Distorted [HgS4] Motif-Driven Structural Symmetry Degradation and Strengthened Second-Harmonic Generation Response in the Defect Diamond-Like Chalcogenide Hg3P2S8

• DOI: 10.1021/acsami.1c06933
• Publication Date: 2021-07-28T18:33:59Z
• Authors: Wenhao Xing; Fei Liang; Chunlan Tang; Ece Uykur; Zheshuai Lin; Jiyong Yao; Wenlong Yin; Bin Kang
• Keywords: Orthorhombic crystal system; Tetragonal crystal system

Chalcogenides with diamond-like (DL) structures are a treasury of infrared nonlinear optical (NLO) materials. Here, ternary Hg-based chalcogenide defect DL structure, Hg3P2S8, is synthesized by solid-state reaction. Driven the highly distorted [HgS4] tetrahedra, this compound displays an interesting structural symmetry degradation from tetragonal to orthorhombic compared its analogue Zn3P2S8. Meanwhile, overall performances Hg3P2S8 quite remarkable, including very strong phase-matchable second-harmonic generation (SHG) response (4.2 × AgGaS2), large band gap (2.77 eV), wide IR transparent range (0.45–16.7 μm), and high laser-induced damage threshold (4 AGS). Furthermore, theoretical analysis local dipole moment calculations elucidate that tetrahedra contribute lot enhancement SHG effect. This discovery will motivate exploration other chalcogenides serving as high-performing mid-IR NLO