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 Cs3Ga8S13Cl and Cs9Ga8Se12Cl9 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. Cs3Ga8S13Cl shows a wide bandgap of approximate to 3.76 eV, resulting in a high laser-induced damage threshold of approximate to 8 x AgGaS2 (AGS) and a moderate NLO response (approximate to 0.6 x AGS) with phase-matching behavior. The results imply that Cs3Ga8S13Cl 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.