Mixed Anionic Tetrahedra Guided Design of New Infrared Nonlinear Optical Material Cs3Ga8S13Cl with High Laser-Induced Damage Threshold

The development of anti-laser damage infrared (IR) nonlinear optical (NLO) materials is an urgent need but challenging due to the contradiction between wide bandgap and large NLO coefficient. Herein, by introducing a halogen into the NLO-active tetrahedral unit, two halogenated metal chalcogenides Cs 3 Ga 8 S 13 Cl and Cs 9 Ga 8 Se 12 Cl 9 with unprecedented [GaQ 3 Cl] (Q = S/Se) tetrahedral units are rationally designed and fabricated in experiments by the flux method, enriching the chemical and structural diversity of chalcogenides. Cs 3 Ga 8 S 13 Cl shows a wide bandgap of ≈3.76 eV, resulting in a high laser-induced damage threshold of ≈8 × AgGaS 2 (AGS) and a moderate NLO response (≈0.6 × AGS) with phase-matching behavior. The results imply that Cs 3 Ga 8 S 13 Cl is a promising IR NLO material for the high powder laser application and demonstrate the feasibility of the halogenated tetrahedron strategy in regulating the optical properties of chalcogenides.