You Fengguang, Liang Fei, Huang Qian, Hu Zhanggui, Wu Yicheng, Lin Zheshuai
Technical Institute of Physics and Chemistry, Chinese Academy of Sciences , Beijing 100190 , China.
University of Chinese Academy of Sciences , Beijing 100190 , China.
J Am Chem Soc. 2019 Jan 16;141(2):748-752. doi: 10.1021/jacs.8b11485. Epub 2018 Nov 30.
Wide bandgap and strong second-order generation (SHG) effect are two crucial but contradictory conditions for practical nonlinear optical (NLO) materials. Herein, a new NLO crystal PbGaF(SeO)Cl (I) containing novel functional (GaOF) octahedra is designed and synthesized by a rational band engineering strategy with aliovalent substitution. Benefiting from the removal of transition metal cations and the introduction of bridged F anions, I exhibits the widest bandgap among all reported phase-matchable NLO selenites. Meanwhile, a strong SHG response more than 4.5 times of KHPO (KDP) is maintained. The dominate role of the (GaOF) groups to the enlarged bandgap in I are elucidated by first-principles studies.
宽带隙和强二次谐波产生（SHG）效应是实用非线性光学（NLO）材料的两个关键但相互矛盾的条件。在此，通过具有异价取代的合理能带工程策略，设计并合成了一种含有新型功能（GaOF）八面体的新型NLO晶体PbGaF(SeO)Cl（I）。得益于过渡金属阳离子的去除和桥连F阴离子的引入，I在所有报道的可相位匹配的NLO亚硒酸盐中表现出最宽的带隙。同时，保持了比KHPO（KDP）强4.5倍以上的强SHG响应。通过第一性原理研究阐明了（GaOF）基团对I中扩大带隙的主导作用。
