Yin Huilin, Wu Xia, Wu Shuchang, Sun Changsheng, Wang Chengxiao, Sun Jiaman, Liu Yang, Jiang Xiaoming, Lv Ximeng, Mei Dajiang
College of Chemistry and Chemical Engineering, Shanghai University of Engineering Science, Shanghai 201620, China.
School of Materials and Chemical Engineering, Ningbo University of Technology, Ningbo 315211, China.
Inorg Chem. 2025 Sep 15;64(36):18074-18079. doi: 10.1021/acs.inorgchem.5c03601. Epub 2025 Sep 4.
Infrared (IR) nonlinear optical (NLO) crystals are crucial for mid-IR lasers, yet their intrinsic narrow band gaps cause low laser-induced damage thresholds (LIDTs) and detrimental two-photon absorption, thus limiting their widespread application. Herein, a synergistic strategy involving d-orbital exclusion and polarization motif construction is employed to synthesize novel chalcogenide SrZnSiS by introducing [SiS] and [ZnS] tetrahedral polarization subunits. Performance evaluation demonstrates that SrZnSiS breaks through the "4.0 eV" band gap threshold and holds the broadest band gap of 4.35 eV among the second-harmonic generation (SHG) > 0.5 × AgGaS sulfur compound series, accompanied by an SHG response of 0.7 × AgGaS and high LIDTs (>10 × AgGaS). Theoretical calculations reveal that SrZnSiS can achieve phase matching with Δn = 0.05 at 1064 nm. Significantly, this material overcomes limitations of existing samples that offer an SHG coefficient above 0.5 × AgGaS, and it realizes synergistic optimization of a wide band gap and high nonlinearity.
红外（IR）非线性光学（NLO）晶体对于中红外激光器至关重要，然而其固有的窄带隙导致低激光诱导损伤阈值（LIDT）和有害的双光子吸收，从而限制了它们的广泛应用。在此，通过引入[SiS]和[ZnS]四面体极化亚基，采用了一种涉及d轨道排斥和极化 motif 构建的协同策略来合成新型硫族化物 SrZnSiS。性能评估表明，SrZnSiS突破了“4.0 eV”的带隙阈值，在二次谐波产生（SHG）>0.5×AgGaS的硫化合物系列中拥有4.35 eV的最宽带隙，同时具有0.7×AgGaS的SHG响应和高LIDT（>10×AgGaS）。理论计算表明，SrZnSiS在1064 nm处可实现Δn = 0.05的相位匹配。值得注意的是，这种材料克服了现有样品中SHG系数高于0.5×AgGaS的局限性，并实现了宽带隙和高非线性的协同优化。
