Liu Haonan, Zhai Xuming, Li Xinru, Wu Hongping, Hu Zhanggui, Wang Jiyang, Wu Yicheng, Yu Hongwei
Tianjin Key Laboratory of Functional Crystal Materials, Institute of Functional Crystal, College of Materials Science and Engineering, Tianjin University of Technology, Tianjin, 300384, China.
Angew Chem Int Ed Engl. 2025 May;64(19):e202502252. doi: 10.1002/anie.202502252. Epub 2025 Mar 11.
Deep-ultraviolet nonlinear optical (DUV NLO) crystals play a vitally important role in many scientific and technological fields, yet their rational design remains an ongoing challenge. Here, through utilizing the ordered structure design, a new KBeBOF-like DUV transparent NLO crystal CsKY(BO) has been successfully designed and synthesized, in which we first use the largest π-conjugated BO functional groups to substitute the BO to maximize the second-harmonic generation (SHG) response and utilize the K/YO connecting groups to replace two BeOF groups to optimize the layer connections. Eventually, CsKY(BO) exhibits not only the largest SHG responses in KBeBOF-like DUV borates but also the best growth rate along c axis (the strong layer-habit along c axis has been being the greatest obstacle to prohibit the practical application of KBeBOF and its derivative). Clearly, the substitution from BO triangles to similar topological BO groups and from (BeOF) groups to similar topological K/YO octahedra can better modulate the functional properties of materials in the larger scale. That results in the superior comprehensive properties of CsKY(BO) and makes it a promising DUV NLO crystal. Therefore, the ordered structure design provides some new insights for assembling the functional and connecting groups to rationally design materials with high-performance.
深紫外非线性光学（DUV NLO）晶体在许多科技领域发挥着至关重要的作用，但其合理设计仍然是一个持续的挑战。在此，通过利用有序结构设计，成功设计并合成了一种新型类KBeBOF的深紫外透明NLO晶体CsKY(BO)，其中我们首次使用最大的π共轭BO官能团取代BO以最大化二次谐波产生（SHG）响应，并利用K/YO连接基团取代两个BeOF基团以优化层连接。最终，CsKY(BO)不仅在类KBeBOF的深紫外硼酸盐中表现出最大的SHG响应，而且沿c轴具有最佳的生长速率（沿c轴的强层习性一直是阻碍KBeBOF及其衍生物实际应用的最大障碍）。显然，从BO三角形到类似拓扑结构的BO基团以及从(BeOF)基团到类似拓扑结构的K/YO八面体的取代能够在更大尺度上更好地调节材料的功能特性。这导致了CsKY(BO)具有优异的综合性能，并使其成为一种有前景的深紫外NLO晶体。因此，有序结构设计为组装功能和连接基团以合理设计高性能材料提供了一些新的见解。
