Tunable 2D binary colloidal alloys for soft nanotemplating

Miguel Ángel Fernández-Rodríguez, Roey Elnathan, Ran Ditcovski, Fabio Grillo, Gaurasundar Marc Conley, Flavia Timpu, Astrid Rauh, Karen Geisel, Tal Ellenbogen, Rachel Grange, Frank Scheffold, Matthias Karg, Walter Richtering, Nicolas H. Voelcker, Lucio Isa

Research output: Contribution to journalArticleResearchpeer-review

18 Citations (Scopus)

Abstract

The realization of non-close-packed nanoscale patterns with multiple feature sizes and length scales via colloidal self-assembly is a highly challenging task. We demonstrate here the creation of a variety of tunable particle arrays by harnessing the sequential self-assembly and deposition of two differently sized microgel particles at the fluid-fluid interface. The two-step process is essential to achieve a library of 2D binary colloidal alloys, which are kinetically inaccessible by direct co-assembly. These versatile binary patterns can be exploited for a range of end-uses. Here we show that they can for instance be transferred to silicon substrates, where they act as masks for the metal-assisted chemical etching of binary arrays of vertically aligned silicon nanowires (VA-SiNWs) with fine geometrical control. In particular, continuous binary gradients in both NW spacing and height can be achieved. Notably, these binary VA-SiNW platforms exhibit interesting anti-reflective properties in the visible range, in agreement with simulations. The proposed strategy can also be used for the precise placement of metallic nanoparticles in non-close-packed arrays. Sequential depositions of soft particles enable therefore the exploration of complex binary patterns, e.g. for the future development of substrates for biointerfaces, catalysis and controlled wetting.

Original languageEnglish
Pages (from-to)22189-22195
Number of pages7
JournalNanoscale
Volume10
Issue number47
DOIs
Publication statusPublished - 21 Dec 2018

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