title: Large-scale assembly of colloidal nanoparticles and fabrication of periodic subwavelength structures.
abstract: This paper reports a simple and scalable spin-coating technique for assembling 70 nm silica nanoparticles into non-close-packed colloidal crystals over a large area. The thickness of the shear-aligned colloidal crystals can be controlled from hundreds of layers to a single monolayer by adjusting the spin-coating conditions. We further demonstrate that the spin-coated colloidal monolayers can be used as structural templates to pattern sub-100 nm pillar arrays directly on silicon substrates. The resulting subwavelength-structured pillar arrays exhibit excellent broadband antireflective and superhydrophobic properties, which are promising for developing self-cleaning antireflection coatings for crystalline silicon solar cells. This bottom-up approach enables large-scale production of periodic nanostructures with resolution beyond the optical diffraction limit that have important technological applications ranging from high-density data storage and optoelectronics to biological sensing and subwavelength optics.
authors.affiliation: Department of Chemical Engineering, University of Florida, Gainesville, FL 32611, USA.
authors.forename: Wei-Lun
authors.initials: WL
authors.lastname: Min
authors.forename: Peng
authors.initials: P
authors.lastname: Jiang
authors.forename: Bin
authors.initials: B
authors.lastname: Jiang