Fully Tunable Silicon Nanowire Arrays Fabricated by Soft Nanoparticle Templating

Marcel Rey, Roey Elnathan, Ran Ditcovski, Karen Geisel, Michele Zanini, Miguel-Angel Fernandez-Rodriguez, Vikrant V. Naik, Andreas Frutiger, Walter Richtering, Tal Ellenbogen, Nicolas H. Voelcker, Lucio Isa

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70 Citations (Scopus)

Abstract

We demonstrate a fabrication breakthrough to produce large-area arrays of vertically aligned silicon nanowires (VA-SiNWs) with full tunability of the geometry of the single nanowires and of the whole array, paving the way toward advanced programmable designs of nanowire platforms. At the core of our fabrication route, termed "Soft Nanoparticle Templating", is the conversion of gradually compressed self-assembled monolayers of soft nanoparticles (microgels) at a water-oil interface into customized lithographical masks to create VA-SiNW arrays by means of metal-assisted chemical etching (MACE). This combination of bottom-up and top-down techniques affords excellent control of nanowire etching site locations, enabling independent control of nanowire spacing, diameter and height in a single fabrication route. We demonstrate the fabrication of centimeter-scale two-dimensional gradient photonic crystals exhibiting continuously varying structural colors across the entire visible spectrum on a single silicon substrate, and the formation of tunable optical cavities supported by the VA-SiNWs, as unambiguously demonstrated through numerical simulations. Finally, Soft Nanoparticle Templating is combined with optical lithography to create hierarchical and programmable VA-SiNW patterns.

Original languageEnglish
Pages (from-to)157-163
Number of pages7
JournalNano Letters
Volume16
Issue number1
DOIs
Publication statusPublished - 13 Jan 2016
Externally publishedYes

Keywords

  • 2D photonic crystals
  • fluid interfaces
  • microgels
  • nanoscale patterning
  • optical cavities
  • Vertically aligned nanowires

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