KREP2S6 (RE = Sm, Gd, Tb, Dy): A Series of Polar Rare-Earth Thiophosphates with High Laser-Induced Damage Thresholds and Moderate Nonlinear-Optical Responses Synergistically Contributed by Isolated P2S6 Units and {[RE2S15]24-}∞ Layers

Chen-Yi Zhao; Wen-Dong Yao; Ming-Yang Li; Wenfeng Zhou; Wenlong Liu; Sheng-Ping Guo

doi:10.1021/acs.inorgchem.4c00131

KREP₂S₆ (RE = Sm, Gd, Tb, Dy): A Series of Polar Rare-Earth Thiophosphates with High Laser-Induced Damage Thresholds and Moderate Nonlinear-Optical Responses Synergistically Contributed by Isolated P₂S₆ Units and {[RE₂S₁₅]^24-}_∞ Layers

Inorg Chem. 2024 Mar 4;63(9):4017-4021. doi: 10.1021/acs.inorgchem.4c00131. Epub 2024 Feb 17.

Authors

Chen-Yi Zhao¹, Wen-Dong Yao¹, Ming-Yang Li², Wenfeng Zhou¹, Wenlong Liu¹, Sheng-Ping Guo^{1

2}

Affiliations

¹ School of Chemistry and Chemical Engineering, Yangzhou University, Yangzhou 225002, P. R. China.
² Yunnan Key Laboratory of Electromagnetic Materials and Devices, National Center for International Research on Photoelectric and Energy Materials, School of Materials and Energy, Yunnan University, Kunming 650091, P. R. China.

PMID: 38367266
DOI: 10.1021/acs.inorgchem.4c00131

Abstract

As one of the potential candidates of nonlinear-optical (NLO) materials, rare-earth chalcophosphates have demonstrated promising properties. Here, KREP₂S₆ (RE = Sm, Gd, Tb, Dy) were synthesized using the facile RE₂O₃-B-S solid-state method. They crystallize with a monoclinic chiral P2₁ structure, and their layer structures are built by isolated ethane-like P₂S₆ dimers and RES₈ bicapped trigonal prisms built {[RE₂S₁₅]^24-}_∞ layers. By comparing the structures with related ones, the change of the alkali metal or RE³⁺ ions can cause structural transformation. Their band gaps are tunable between 2.58 and 3.79 eV, and their powder samples exhibit good NLO properties. Theoretical calculations suggest that the NLO properties are mainly contributed by P₂S₆ units and {[RE₂S₁₅]^24-}_∞ layers synergistically, in which {[RE₂S₁₅]^24-}_∞ layers and P₂S₆ units dominate the contribution to the band gap and second-harmonic-generation response, respectively. This work enriches the application of rare-earth chalcophosphates as NLO materials.