Intrinsic helical twist and chirality in ultrathin tellurium nanowires
Intrinsic helical twist and chirality in ultrathin tellurium nanowires
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DOI：
10.1039/d1nr01442k
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发表时间：
2021-05-13
期刊：
影响因子：
6.7
通讯作者：
Pettes, Michael T.
中科院分区：
文献类型：
--
作者：
Londono-Calderon, Alejandra;Williams, Darrick J.;Pettes, Michael T.
现在在一维形式的碲中观察到了鲁棒的原子到介观尺度的手性。这使得能够产生大于 0.2 的大且反直觉的与圆极化相关的二次谐波生成响应，这在二维碲中是不存在的。通过四维扫描透射电子显微镜 (4D-STEM) 获得的一维碲纳米线的取向变化及其与二次谐波圆二色性 (SHG-CD) 的非常规非线性光学特性的相关性揭示了一维纳米线束的意想不到的依赖于圆偏振的 SHG 响应 - 比单晶二维碲结构高一个数量级 - 表明了原子和介观尺度的晶体结构一维材料具有二维形式所不存在的固有手性；并且其强度足以体现在聚集体的聚集非线性光学（NLO）特性中。
Robust atomic-to-meso-scale chirality is now observed in the one-dimensional form of tellurium. This enables a large and counter-intuitive circular-polarization dependent second harmonic generation response above 0.2 which is not present in two-dimensional tellurium. Orientation variations in 1D tellurium nanowires obtained by four-dimensional scanning transmission electron microscopy (4D-STEM) and their correlation with unconventional non-linear optical properties by second harmonic generation circular dichroism (SHG-CD) uncovers an unexpected circular-polarization dependent SHG response from 1D nanowire bundles - an order-of-magnitude higher than in single-crystal two-dimensional tellurium structures - suggesting the atomic- and meso-scale crystalline structure of the 1D material possesses an inherent chirality not present in its 2D form; and which is strong enough to manifest even in the aggregate non-linear optical (NLO) properties of aggregates.