Zhou Jiazheng, Hou Ketian, Chu Yu, Yang Zhihua, Li Junjie, Pan Shilie
Research Center for Crystal Materials, CAS Key Laboratory of Functional Materials and Devices for Special Environments, Xinjiang Technical Institute of Physics & Chemistry, CAS, 40-1 South Beijing Road, Urumqi, 830011, China.
Small. 2024 Apr;20(16):e2308806. doi: 10.1002/smll.202308806. Epub 2023 Nov 27.
Developing high-performance infrared (IR) nonlinear optical (NLO) materials is urgent but challenging due to the competition between NLO coefficient and bandgap in one compound. Herein, by coupling NLO-active [BS] planar units and halide-centered polycations, six new metal thioborate halides ABaBSX (A = Rb, Cs; X = Cl, Br, I) composed of zero-dimensional [XBaRb/Cs] polycations and [BS] units, belonging to a new family, are rationally designed and fabricated. The compounds show an interesting structural transition from Pbcn (ABaBSCl) to Cmc2 (ABaBSBr and ABaBSI) driven by the clamping effect of polycationic frameworks. ABaBSBr and ABaBSI are the first series metal thioborate halide IR NLO materials, and the introduction of [BS] unit effectively widens the bandgap of planar unit-constructed chalcogenides. ABaBSBr and ABaBSI, exhibiting wide bandgaps (3.55-3.60 eV), high laser-induced damage thresholds (≈ 6 × AgGaS), and strong SHG effects (0.5-0.6 × AgGaS) with phase-matching behaviors, are the promising IR NLO candidates for high-power laser applications. The results enrich the chemical and structural diversity of boron chemistry and give some insights into the design of new IR NLO materials with planar units.
由于在一种化合物中非线性光学（NLO）系数与带隙之间存在竞争关系，开发高性能红外（IR）非线性光学材料既迫切又具有挑战性。在此，通过将NLO活性的[BS]平面单元与卤化物中心的聚阳离子耦合，合理设计并制备了六种新型金属硫代硼酸盐卤化物ABaBSX（A = Rb，Cs；X = Cl，Br，I），它们由零维的[XBaRb/Cs]聚阳离子和[BS]单元组成，属于一个新的家族。这些化合物表现出由聚阳离子框架的钳位效应驱动的从Pbcn（ABaBSCl）到Cmc2（ABaBSBr和ABaBSI）的有趣结构转变。ABaBSBr和ABaBSI是首个系列的金属硫代硼酸盐卤化物红外NLO材料，[BS]单元的引入有效地拓宽了由平面单元构建的硫族化物的带隙。ABaBSBr和ABaBSI具有宽带隙（3.55 - 3.60 eV）、高激光损伤阈值（≈ 6 × AgGaS）以及具有相位匹配行为的强倍频效应（0.5 - 0.6 × AgGaS），是高功率激光应用中有前景的红外NLO候选材料。这些结果丰富了硼化学的化学和结构多样性，并为具有平面单元的新型红外NLO材料的设计提供了一些见解。
