Wet etching-assisted colloidal lithography: a general strategy toward nanodisk and nanohole arrays on arbitrary substrates.

A simple and facile strategy is presented to fabricate the metal nanodisk and nanohole arrays based on a wet etching-assisted polystyrene colloidal lithography. Gold is chosen to demonstrate the validity of such a strategy. The hexagonally arranged Au nanodisk and nanohole arrays are thus fabricated with large area and good uniformity. The structural parameters of the arrays, such as thicknesses, diameters, and spacings of the nanodisks or nanoholes, are facilely tunable and controllable by predeposition conditions, etching conditions and colloidal monolayer structure. More importantly, these arrays can be produced on any supporting substrates, such as conductive or nonconductive and even flexible substrates with flat, rough, or even curved surfaces. In general, the presented strategy is low in cost, simple in operation and arbitrary in substrate, and the as-prepared arrays could find potential devices' applications with nice compatibility in the fields of optics, surface-enhanced Raman spectroscopy, biosensing, and so forth.