The search for new non-centrosymmetric (NCS) crystals with wide energy-gaps (E_g) and strong second-harmonic generation (SHG) responses has become one of the greatest challenges in the mid- and far-infrared (MFIR) nonlinear optical (NLO) field. In this work, a novel quaternary NCS material Sr₅ZnGa₆S₁₅ (SZGS), which contains a complex 3D anionic framework and possesses the optical properties required for the MFIR NLO applications, especially the good balance between wide E_g (3.15 eV) and large SHG response (d_ij = 1.2 × AgGaS₂), has been discovered for the first time. Moreover, the result of theoretical calculation further indicates that the 3D [ZnGa₆S₁₅]¹⁰⁻ framework makes definitive contributions to the NLO properties. All these studies demonstrate that SZGS is a promising NLO candidate in the MFIR region.

中文翻译：

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Sr ₅ ZnGa ₆ S ₁₅：具有3D框架结构的新型四元非中心对称半导体，具有出色的非线性光学性能†

寻找具有宽能隙（E _g）和强二次谐波产生（SHG）响应的新型非中心对称（NCS）晶体已成为中红外（MFIR）非线性光学领域的最大挑战之一（NLO）字段。在这项工作中，新型的四元NCS材料Sr ₅ ZnGa ₆ S ₁₅（SZGS）包含复杂的3D阴离子骨架，并具有MFIR NLO应用所需的光学性能，尤其是宽E _g（3.15 eV）之间的良好平衡。和较大的SHG响应（d _ij = 1.2×AgGaS ₂），是首次发现。此外，理论计算的结果还表明，3D [ZnGa ₆ S ₁₅ ] ^10-骨架对NLO性能做出了明确的贡献。所有这些研究表明，SZGS在MFIR地区是有前途的NLO候选者。