Eu<sub>2</sub>P<sub>2</sub>S<sub>6</sub>: The First Rare‐Earth Chalcogenophosphate Exhibiting Large Second‐Harmonic Generation Response and High Laser‐Induced Damage Threshold
Xiao Huang, Sihan Yang, Xiaohui Li, Wenlong Liu, Sheng‐Ping Guo
Abstract
Abstract Metal chalcogenophosphates are receiving increasing interest, specifically as promising infrared nonlinear optical (NLO) candidates. Here, a rare‐earth chalcogenophosphate Eu 2 P 2 S 6 crystallizing in the monoclinic noncentrosymmetric space group Pn was synthesized using a high‐temperature solid‐state method. Its structure features isolated [P 2 S 6 ] 4− dimer, and two types of EuS 8 bicapped triangular prisms. Eu 2 P 2 S 6 exhibits a phase‐matchable second‐harmonic generation (SHG) response ≈0.9×AgGaS 2 @2.1 μ m, and high laser‐induced damage threshold of 3.4×AgGaS 2 , representing the first rare‐earth NLO chalcogenophosphate. The theoretical calculation result suggests that the SHG response is ascribed to the synergetic contribution of [P 2 S 6 ] 4− dimers and EuS 8 bicapped triangular prisms. This work provides not only a promising high‐performance infrared NLO material, but also opens the avenue for exploring rare‐earth chalcogenophosphates as potential IR NLO materials.