Coordinated regulation on critical physiochemical performances activated from mixed tetrahedral anionic ligands in new series of Sr6A4M4S16 (A = Ag, Cu; M = Ge, Sn) nonlinear optical materials

Abstract

A new family of non-centrosymmetric (NCS) compounds Sr₆A₄M₄S₁₆ (A = Ag, Cu; M = Ge, Sn) with mixed tetrahedral anionic ligands (AS₄ and MS₄) was successfully synthesized and characterized for the first time. All of the compounds exhibit excellent performances as promising infrared nonlinear optical (IR NLO) materials, with large NLO responses (1.1–2.0 × benchmark AgGaS₂), high laser damage thresholds (2.0–4.5 × AgGaS₂) and wide IR transmission ranges, and are nonhygroscopic. Moreover, their property modulation by the combination of different anionic groups was also discussed.