A Chemical Approach To Break the Planar Configuration of Ag Nanocubes into Tunable Two-Dimensional Metasurfaces.
A Chemical Approach To Break the Planar Configuration of Ag Nanocubes into Tunable Two-Dimensional Metasurfaces.
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DOI：
10.1021/acs.nanolett.6b01388
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发表时间：
2016-05
期刊：
影响因子：
10.8
通讯作者：
Yijie Yang;Yih Hong Lee;I. Phang;R. Jiang;Howard Yi Fan Sim;Jianfang Wang;X. Ling
中科院分区：
文献类型：
--
作者：
Yijie Yang;Yih Hong Lee;I. Phang;R. Jiang;Howard Yi Fan Sim;Jianfang Wang;X. Ling
当前纳米立方体的等离子体超表面限于平面配置，限制了创建定制的局部电磁场的能力。在这里，我们报告了一种新的化学策略，以实现可调超颖表面与非平面纳米立方体的方向，创造新的晶格依赖的场定位模式。我们操纵的银纳米立方体的界面行为，通过控制的比例添加在一个二元硫醇混合物在表面功能化的步骤中的亲水/疏水分子。因此，在油/水界面的纳米立方体的取向可以从平面连续调整到倾斜和站立的配置，导致银纳米立方体的组织成三个独特的大面积亚晶，包括正方形密堆积，线性和六方晶格。特别是，线性和六方晶是不寻常的开放晶格，包括非平面纳米立方体，创造独特的局部电磁场分布模式。在六方晶中形成了大面积的热点离域的“热六边形”。具有24%的最低堆积密度，六方晶生成近350倍强的表面增强的拉曼散射相比，其他致密堆积的超晶，证明了实现控制超晶中的纳米立方体的几何和空间取向的重要性。
Current plasmonic metasurfaces of nanocubes are limited to planar configurations, restricting the ability to create tailored local electromagnetic fields. Here, we report a new chemical strategy to achieve tunable metasurfaces with nonplanar nanocube orientations, creating novel lattice-dependent field localization patterns. We manipulate the interfacial behaviors of Ag nanocubes by controlling the ratio of hydrophilic/hydrophobic molecules added in a binary thiol mixture during the surface functionalization step. The nanocube orientation at an oil/water interface can consequently be continuously tuned from planar to tilted and standing configurations, leading to the organization of Ag nanocubes into three unique large-area metacrystals, including square close-packed, linear, and hexagonal lattices. In particular, the linear and hexagonal metacrystals are unusual open lattices comprising nonplanar nanocubes, creating unique local electromagnetic field distribution patterns. Large-area "hot hexagons" with significant delocalization of hot spots form in the hexagonal metacrystal. With a lowest packing density of 24%, the hexagonal metacrystal generates nearly 350-fold stronger surface-enhanced Raman scattering as compared to the other denser-packing metacrystals, demonstrating the importance of achieving control over the geometrical and spatial orientation of the nanocubes in the metacrystals.