Wang Hongshan, An Ran, Du Yinxia, Pan Shilie, Li Junjie
Opt Express. 2025 Apr 21;33(8):18170-18179. doi: 10.1364/OE.555811.
Developing new infrared (IR) nonlinear optical (NLO) materials with strong NLO response and wide band gap is highly desired in the NLO fields but challenging due to the contradiction between the two critical parameters. In this work, by optimizing the advantageous structural motifs, a new selenide IR NLO candidate SrZnGeSe was rationally designed, fabricated, and validated in the experiment. Structurally, SrZnGeSe is composed of [ZnSe], [GeSe], and [SrSe] units, resulting in a tunnel-like three-dimensional structure. The synergistic effect of polyhedral units in SrZnGeSe gives rise to balanced optical properties, including a wide band gap (2.5 eV) in selenides, a strong NLO response (1.8 × AgGaS), and a high laser-induced damage threshold (3.3 × AgGaS). The density functional theory calculations uncover that the wide optical band gap and large NLO effect in SrZnGeSe are primarily governed by the advantageous [ZnSe] and [GeSe] NLO-active units. The experimental and theoretical results indicate that SrZnGeSe is a promising IR NLO candidate and give some new insights into the design of new IR NLO materials with high performance.
在非线性光学（NLO）领域，开发具有强NLO响应和宽带隙的新型红外（IR）非线性光学材料是非常有必要的，但由于这两个关键参数之间的矛盾，这一过程具有挑战性。在这项工作中，通过优化有利的结构基序，合理设计、制备并在实验中验证了一种新型硒化物IR NLO候选材料SrZnGeSe。在结构上，SrZnGeSe由[ZnSe]、[GeSe]和[SrSe]单元组成，形成了一种隧道状三维结构。SrZnGeSe中多面体单元的协同效应产生了平衡的光学性质，包括硒化物中较宽的带隙（2.5 eV）、较强的NLO响应（1.8×AgGaS）和较高的激光损伤阈值（3.3×AgGaS）。密度泛函理论计算表明，SrZnGeSe中较宽的光学带隙和较大的NLO效应主要由有利的[ZnSe]和[GeSe]NLO活性单元决定。实验和理论结果表明，SrZnGeSe是一种有前途的IR NLO候选材料，并为高性能新型IR NLO材料的设计提供了一些新的见解。
