Quantifying Order during Field-Driven Alignment of Colloidal Semiconductor Nanorods
Quantifying Order during Field-Driven Alignment of Colloidal Semiconductor Nanorods
复制标题
胶体半导体纳米棒场驱动排列期间的量化顺序
DOI：
10.1021/acsnano.1c08488
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发表时间：
2022
期刊：
影响因子：
17.1
通讯作者：
Sheldon, Matthew T.
中科院分区：
文献类型：
--
作者：
Ratnaweera, Rivi J.;Rodríguez Ortiz, Freddy A.;Gripp, Nicholas J.;Sheldon, Matthew T.
将大量的胶体纳米棒（NR）排列成有序的组装体，为工程设计具有强光学各向异性的宏观功能材料提供了一种策略。这种系统的体光学性质不仅取决于单个NR结构单元，而且还取决于它们的介观和宏观有序性，以及更复杂的粒子间耦合效应。在这里，我们调查的动态排列的胶体CdSe/CdS NR的存在下，交流电场通过测量并发的光传输的变化。我们的工作确定了两种不同的相互作用尺度，产生了场驱动的光学响应：（1）自发的介观尺度的自组装成结构的胶体NR与增加的光学各向异性和（2）NR组件的宏观有序沿着所施加的AC场的方向。通过建模的NR合奏使用方向统计的对齐，我们实验量化的最大程度的秩序相对于场轴的平均偏差角。结果显示，随着NR浓度的变化，排列的一致性得到了改善，最小平均偏差为36.2°，这表明中尺度组装有助于促进胶体NR的场驱动排列。
Aligning large populations of colloidal nanorods (NRs) into ordered assemblies provides a strategy for engineering macroscopic functional materials with strong optical anisotropy. The bulk optical properties of such systems depend not only on the individual NR building blocks but also on their meso- and macroscale ordering, in addition to more complex interparticle coupling effects. Here, we investigate the dynamic alignment of colloidal CdSe/CdS NRs in the presence of AC electric fields by measuring concurrent changes in optical transmission. Our work identifies two distinct scales of interaction that give rise to the field-driven optical response: (1) the spontaneous mesoscale self-assembly of colloidal NRs into structures with increased optical anisotropy and (2) the macroscopic ordering of NR assemblies along the direction of the applied AC field. By modeling the alignment of NR ensembles using directional statistics, we experimentally quantify the maximum degree of order in terms of the average deviation angle relative to the field axis. Results show a consistent improvement in alignment as a function of NR concentration─with a minimum average deviation of 36.2°─indicating that mesoscale assembly helps facilitate field-driven alignment of colloidal NRs.