中国科学院理化所康雷团队开发出了具有超大光学各向异性的同原子多硫系非线性光学阴离子基团。相关研究成果于2024年5月31日发表在国际顶尖学术期刊《美国化学会杂志》。

具有大光学各向异性的非线性光学（NLO）基元的功能组装，对于开发先进的NLO和双折射材料至关重要。

该文中，研究发现，除了杂原子NLO基序外，由聚集的阴离子（S、Se、Te）形成的同原子阴离子团簇还表现出不同的链状、环状和笼状化学结构以及一维、二维和三维基序排列。丰富的结构化学使同原子多硫族化合物（HAPCs）能够表现出不对称的结构特征和各向异性的光学性质，在NLO和双折射性能方面具有巨大的潜力。针对总共55个二元HAPCs A₂Q_n（n=2，3，4，5；A=Na，K，Rb，Cs；Q=S，Se，Te）及其三元类似物，研究人员采用最先进的第一性原理方法，系统地研究了它们的NLO和双折射特性的调制演变。

值得注意的是，Rb₂Te₃和Na₂TeSe₂很少表现出巨大的双折射（>1.0@10μm）和NLO效应（>20×AgGaS₂），远大于传统的NLO硫族化物。Na₂Te₃呈现出迄今为止最大的双折射（～3.48@1, 2.72@2, 2.34@10μm），表明HAPC在超大双折射方面具有独特的结构优势。通过挖掘其内在机理，HAPC阴离子基团被鉴定为新型中红外非直瞄“材料基因”，为新型光电材料的设计提供了独特的非直瞄和双折射性能。

附：英文原文

Title: Homoatomic Polychalcogenide Nonlinear Optical Anionic Groups with Ultra-Large Optical Anisotropy

Author: Aoge Yao, Fan Liu, Bohui Xu, Hao Huo, Zheshuai Lin, Lei Kang

Issue&Volume: May 31, 2024

Abstract: Functional assembly of nonlinear optical (NLO) motifs with a large optical anisotropy is vital to the development of advanced NLO and birefringent materials. In this work, we highlight that, in addition to heteroatomic NLO motifs, homoatomic anionic clusters formed by aggregated anions (S, Se, Te) exhibit diverse chain-, ring-, and cage-like chemical structures as well as one-, two-, and three-dimensional motif alignments. The rich structural chemistry enables homoatomic polychalcogenides (HAPCs) to exhibit asymmetric structural features and anisotropic optical properties, with great potential for NLO and birefringent performance. Focusing on totally 55 binary HAPCs A2Qn (n = 2, 3, 4, 5; A = Na, K, Rb, Cs; Q = S, Se, Te) and their ternary analogues, we employ the state-of-the-art first-principles approach to systematically investigate the modulation evolution of their NLO and birefringent properties. Remarkably, Rb2Te3 and Na2TeSe2 exhibit rarely colossal birefringence (>1.0@10 μm) and NLO effects (>20 × AgGaS2), much larger than conventional NLO chalcogenides. Na2Te3 presents the largest birefringence to date (～3.48@1, 2.72@2, 2.34@10 μm), indicating the unique structural superiority of HAPC in terms of ultra-large birefringence. By mining the intrinsic mechanism, the HAPC anionic groups are identified as novel mid-infrared NLO “material genes”, furnishing unique NLO and birefringent performance for the design of novel optoelectronic materials.

DOI: 10.1021/jacs.4c03708

Source: https://pubs.acs.org/doi/abs/10.1021/jacs.4c03708