Nano Lett. 2019 Aug 14;19(8):5653-5660. doi: 10.1021/acs.nanolett.9b02215. Epub 2019 Aug 6.
The seed-mediated growth of noble metal nanostructures with planar geometries requires the use of seeds lined with parallel stacking faults so as to provide a break in symmetry in an otherwise isotropic metal. Although such seeds are now routinely synthesized using colloidal pathways, equivalent pathways have not yet been reported for the fabrication of substrate-based seeds with the same internal defect structures. The challenge is not merely to form seeds with planar defects but to do so in a deterministic manner so as to have stacking faults that only run parallel to the substrate surface while still allowing for the lithographic processes needed to regulate the placement of seeds. Here, we demonstrate substrate-imposed epitaxy as a viable synthetic control able to induce planar defects in Au seeds while simultaneously dictating nanostructure in-plane alignment and crystallographic orientation. The seeds, which are formed in periodic arrays using nanoimprint lithography in combination with a vapor-phase assembly process, are subjected to a liquid-phase plasmon-mediated synthesis that uses light as an external stimuli to drive a reaction yielding periodic arrays of hexagonal Au nanoplates. These achievements not only represent the first of their kind demonstrations but also advance the possibility of integrating wafer-based technologies with a rich and exciting nanoplate colloidal chemistry.
具有平面几何形状的贵金属纳米结构的种子介导生长需要使用带有平行堆垛层错的种子，以便在各向同性金属中提供对称破缺。尽管现在可以使用胶体途径常规地合成这样的种子，但尚未报道用于制造具有相同内部缺陷结构的基于衬底的种子的等效途径。挑战不仅在于形成具有平面缺陷的种子，而且要以确定的方式来实现，以便仅使堆垛层错平行于衬底表面运行，同时仍然允许进行光刻过程以调节种子的位置。在这里，我们展示了衬底诱导外延作为一种可行的合成控制方法，能够在 Au 种子中诱导平面缺陷，同时控制纳米结构的面内对准和晶体学取向。这些种子是使用纳米压印光刻技术与气相组装工艺结合形成周期性阵列，然后进行液相等离子体介导合成，使用光作为外部刺激来驱动反应，从而得到周期性排列的六方 Au 纳米板。这些成就不仅代表了同类的首次演示，而且还推进了将基于晶圆的技术与丰富而令人兴奋的纳米板胶体化学相结合的可能性。
