Functionalization Based on the Substitutional Flexibility: Strong Middle IR Nonlinear Optical Selenides AX(4)(II)X(5)(III)Se(12)
Functionalization Based on the Substitutional Flexibility: Strong Middle IR Nonlinear Optical Selenides AX(4)(II)X(5)(III)Se(12)
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基于替代灵活性的功能化：强中红外非线性光学硒化物AX(4)(II)X(5)(III)Se(12)
DOI：
10.1021/ja4074084
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发表时间：
2013
影响因子：
15
通讯作者：
Wu Liming
中科院分区：
文献类型：
--
作者：
Lin Hua;Chen Ling;Zhou Liujiang;Wu Liming
采用含ACl助熔剂的单质混合物高温固相反应，合成了kcd4ga5s12型结构的七种非线性光学（NLO）活性硒化物AXII4XIII5Se12（A = K+ -Cs +； XII= Mn2+, Cd2+； XIII= Ga3+, In3+）。它们的三维网络结构由m9se24层顶点共享的mse4四面体堆叠而成，其中每个中心由xiiom和xiiom共同占据。研究表明，这种四面体构建单元可以看作是“多功能位点”，Cd2+/Ga3+对在其上产生NLO和热致变色性能的共存，Mn2+/In3+对在其上产生NLO和磁性能的共存。密度泛函理论（DFT）研究和截止能量依赖的NLO系数分析表明，这些“多功能位点”有助于二次谐波产生（SHG）的起源，这种二次谐波产生归因于xiii和xiii原子从Se-4p态到ns、np态的电子跃迁。值得注意的是，标题化合物在入射波长为2.05 μm时表现出很强的SHG，约为商用AgGaS2的16-40倍；其中，ACd4In5Se12（A = Rb, Cs）是迄今为止硫属化合物中最强的SHG。
Seven nonlinear optical (NLO) active selenides in the middle IR region, AXII4XIII5Se12(A = K+–Cs+; XII= Mn2+, Cd2+; XIII= Ga3+, In3+) adopting the KCd4Ga5S12-type structure, have been synthesized by high-temperature solid-state reaction of an elemental mixture with ACl flux. Their three-dimensional network structures are stacked by M9Se24-layers of vertex sharing MSe4tetrahedra, of which each center is jointly occupied by XIIand XIIIatoms. Studies suggest that such tetrahedral building units can be regarded as the “multi-functional sites”, on which the Cd2+/Ga3+pair gives rise to the coexistence of NLO and thermochromic properties, and the Mn2+/In3+pair leads to the coexistence of NLO and magnetic properties. The density functional theory (DFT) studies and the cutoff-energy-dependent NLO coefficient analyses reveal that such “multi-functional sites” contribute to the origin of the second harmonic generation (SHG) that is ascribed to the electronic transitions from the Se-4p states to the ns, np states of XIIand XIIIatoms. Remarkably, title compounds show very strong SHG at an incident wavelength of 2.05 μm, roughly 16–40 times that of commercial AgGaS2; among them, ACd4In5Se12(A = Rb, Cs) represents the strongest SHG among chalcogenides to date.