Gold binary-structured arrays based on monolayer colloidal crystals and their optical properties.

A simple and flexible route is presented to fabricate a gold binary-structured ordered array by one step based on non-shadow deposition on a plasma etching-induced dualistic monolayer colloidal crystal. Such a Au binary-structure array is built of hexagonally arranged nanoshells and nanorings which stand between two adjacent nanoshells. Six gold nanorings surround each nanoshell. The obtained arrays exhibit both the controllable surface-plasmon-resonance (SPR) properties of Au nanoshells and the strong electromagnetic-field-enhancement effects of Au nanorings, with the high structural stability of ordered arrays, and show promising potential as the substrate of surface-enhanced Raman scattering (SERS)-based devices. The method could also be suitable for fabrication of other material binary-structured arrays. This study is important in designing and fabricating basal materials for the next generation of multifunctional nanostructured devices.