Strong Second Harmonic Generation in a Tungsten Bronze Oxide by Enhancing Local Structural Distortion
Strong Second Harmonic Generation in a Tungsten Bronze Oxide by Enhancing Local Structural Distortion
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通过增强局部结构变形在钨青铜氧化物中产生强二次谐波
DOI：
10.1021/jacs.0c00133
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发表时间：
2020-04-22
影响因子：
15
通讯作者：
Xing, Xianran
中科院分区：
文献类型：
--
作者：
Lin, Kun;Gong, Pifu;Xing, Xianran
为了发现具有强二次谐波效应的非线性光学材料，设计具有大偏振度的非线性光学活性分子单元被认为是一种常用的策略。在此，我们提出，除了非线性光学活性单元外，空位引起的局部结构畸变也可以用来改善固体中的非线性光学效应。在此基础上，设计并制备了一种新型的钨青铜（TB）氧化物Pb-2（Pb0.15Li0.7 square（0.15））Nb 5 O 15（正方形代表空位），其倍频响应是KH 2 PO 4的39倍。详细的分析表明，PLN中的空位增强了局域结构畸变，增强了相邻NbO 6八面体的局域偶极矩，从而显著促进了倍频效应。此外，通过这种分子设计策略，还发现了一系列具有较大非线性光学效应的新型TB化合物，为新型非线性光学材料的合成提供了前景。
To discover the nonlinear optical (NLO) materials with strong second harmonic generation (SHG), the design of NLO-active molecular units with large polarization is considered as a common strategy. Herein, we propose that the local structural distortion induced with vacancies, apart from the NLO-active units, can be employed to improve the NLO effect in solids as well. Accordingly, a new tungsten bronze (TB) oxide, Pb-2(Pb0.15Li0.7 square(0.15))Nb5O15 (square representing vacancies), is successfully designed and prepared, which exhibits a strong SHG response of 39 times that of KH2PO4. The detailed analysis reveals that the local structural distortions enhanced by the vacancies in PLN strengthen the local dipole moments of neighboring NbO6 octahedra, and thus significantly prompt the SHG effect. Moreover, a series of new TB compounds with large NLO effects are discovered by this molecular design strategy, which are perspectives for new NLO materials synthesis.