title: Templated fabrication of periodic arrays of metallic and silicon nanorings with complex nanostructures.
abstract: Here we report a scalable colloidal templating approach for fabricating periodic arrays of metallic and silicon nanorings with complex nanostructures. Non-close-packed monolayer silica colloidal crystal prepared by a simple spin-coating technology is first used as template for making periodic arrays of mushroom-like composite nanostructures consisting of silica spherical caps and polymer stems. Subsequent metal sputtering and reactive ion etching lead to the formation of ordered asymmetric nickel nanorings which can be further utilized as etching masks for patterning periodic arrays of symmetric silicon nanorings. Moreover, periodic arrays of metallic and silicon concentric double nanorings can be fabricated by using the asymmetric nickel nanorings as templates. We have also demonstrated that gold concentric double nanorings show strong surface-enhanced Raman scattering (SERS) with a SERS enhancement factor of ∼9.5 × 10(7) from adsorbed benzenethiol molecules. The SERS enhancement and the electric field amplitude distribution surrounding gold concentric double nanorings have been calculated by using finite element electromagnetic modeling. This new colloidal templating technique is compatible with standard microfabrication and enables wafer-scale production of a variety of periodic nanorings with hierarchical structures that could find important technological applications in plasmonic and magnetic devices.
authors.affiliation: School of Chemical and Material Engineering, Jiangnan University, Wuxi, Jiangsu 214122, People's Republic of China.
authors.forename: Xuefeng
authors.initials: X
authors.lastname: Liu
authors.forename: Numan
authors.initials: N
authors.lastname: Gozubenli
authors.forename: Baeck
authors.initials: B
authors.lastname: Choi
authors.forename: Peng
authors.initials: P
authors.lastname: Jiang
authors.forename: Timothy
authors.initials: T
authors.lastname: Meagher
authors.forename: Bin
authors.initials: B
authors.lastname: Jiang