title: Generalized fabrication of monolayer nonclose-packed colloidal crystals with tunable lattice spacing.
abstract: Here, we report a simple colloidal transfer technology that enables scalable fabrication of monolayer nonclose-packed silica colloidal crystals on a large variety of substrates. Two-dimensional colloidal crystals with an unusual nonclose-packed structure are first assembled on silicon wafers by a spin-coating technique. A poly(vinyl alcohol) (PVA) film cast upon the spin-coated colloidal crystal is used to transfer the nonclose-packed particle arrays onto various substrates. The lattice spacing of the transferred monolayer colloidal crystal can easily be adjusted by thermally treating the PVA-silica spheres composite film for varied durations. We also have demonstrated the templating fabrication of periodic arrays of gold nanodots using a transferred monolayer nonclose-packed colloidal crystal as a structural template. The resultant plasmonic array exhibits high surface-enhanced Raman scattering enhancement factor (~3.8 × 10(7)) for adsorbed benzenethiol molecules.
authors.affiliation: Department of Chemical Engineering, National Chung Hsing University, Taichung 40227, Taiwan. hyang@dragon.nchu.edu.tw
authors.forename: Hongta
authors.initials: H
authors.lastname: Yang
authors.forename: Numan
authors.initials: N
authors.lastname: Gozubenli
authors.forename: Yin
authors.initials: Y
authors.lastname: Fang
authors.forename: Peng
authors.initials: P
authors.lastname: Jiang