International Institute for Nanotechnology, Northwestern University, Evanston, IL, 60208, USA.
Department of Materials Science and Engineering, Northwestern University, Evanston, IL, 60208, USA.
Adv Mater. 2020 Nov;32(47):e2005316. doi: 10.1002/adma.202005316. Epub 2020 Oct 21.
Colloidal crystals have emerged as promising candidates for building optical microdevices. Techniques now exist for synthesizing them with control over their nanoscale features (e.g., particle compositions, sizes, shapes, and lattice parameters and symmetry); however, the ability to tune macroscale structural features, such as the relative positions of crystals to one another and lattice orientations, has yet to be realized. Here, inspiration is drawn from epitaxial growth strategies in atomic crystallization, and patterned substrates are prepared that, when used in conjunction with DNA-mediated nanoparticle crystallization, allow for control over individual Wulff-shaped crystal growth, location, and orientation. In addition, the approach allows exquisite control over the patterned substrate/crystal lattice mismatch, something not yet realized for any epitaxy process. This level of structural control is a significant step toward realizing complex, integrated devices with colloidal crystal components, and this approach provides a model system for further exploration in epitaxy systems.
胶态晶体已成为构建光学微器件的有前途的候选者。现在已经存在用于合成它们的技术，可以控制其纳米级特征（例如，颗粒组成、尺寸、形状、晶格参数和对称性）；然而，调节宏观结构特征（例如晶体之间的相对位置和晶格取向）的能力尚未实现。在这里，我们从原子结晶中的外延生长策略中汲取灵感，并制备图案化衬底，当与 DNA 介导的纳米粒子结晶结合使用时，可以控制单个 Wulff 形状晶体的生长、位置和取向。此外，该方法可以精确控制图案化衬底/晶体晶格失配，这是任何外延工艺都尚未实现的。这种结构控制水平是实现具有胶体晶体组件的复杂集成器件的重要一步，并且该方法为在外延系统中进一步探索提供了模型系统。
