Li Shuaifeng, Li Weiming, Li Xiang, Yang Guangsai, Ye Ning, Hu Zhanggui, Wu Yicheng, Li Conggang
Tianjin Key Laboratory of Functional Crystal Materials, Institute of Functional Crystal, Tianjin University of Technology Tianjin 300384 China.
State Key Laboratory of Crystal Materials, Shandong University Jinan 250100 China.
Chem Sci. 2024 May 6;15(23):8959-8965. doi: 10.1039/d4sc01853b. eCollection 2024 Jun 12.
Strong second-harmonic generation (SHG) and a short ultraviolet (UV) cutoff edge are two crucial yet often conflicting parameters that must be finely tuned in the exploration of nonlinear optical (NLO) materials. In this study, two new rare earth borate NLO crystals, KBaScBO (KBSBO) and RbSrScBO (RSSBO), were rationally designed through a bifunctional primitive strategy to achieve an optimized balance between favorable SHG efficiency and UV transparency. As anticipated, both KBSBO and RSSBO exhibit a wide UV transparency window below 190 nm. Notably, these tailored crystals display strong SHG responses, with RSSBO achieving a remarkable enhancement in SHG efficiency (2 × KDP), surpassing that of most deep-UV rare earth borates containing [BO] groups known to date. Theoretical calculations and structural analyses reveal that the impressive SHG activities primarily stem from the [BO] groups and [ScO] polyhedra. These findings suggest promising potential for KBSBO and RSSBO crystals as beryllium-free deep UV NLO materials.
强二次谐波产生（SHG）和短紫外（UV）截止边是两个关键但往往相互冲突的参数，在非线性光学（NLO）材料的探索中必须进行精细调整。在本研究中，通过双功能基元策略合理设计了两种新型稀土硼酸盐NLO晶体，KBaScBO（KBSBO）和RbSrScBO（RSSBO），以在良好的SHG效率和UV透明度之间实现优化平衡。正如预期的那样，KBSBO和RSSBO在190 nm以下均表现出宽的UV透明窗口。值得注意的是，这些经过定制的晶体显示出强烈的SHG响应，RSSBO的SHG效率显著提高（2×KDP），超过了迄今为止已知的大多数含[BO]基团的深紫外稀土硼酸盐。理论计算和结构分析表明，令人印象深刻的SHG活性主要源于[BO]基团和[ScO]多面体。这些发现表明KBSBO和RSSBO晶体作为无铍深紫外NLO材料具有广阔的应用前景。
