Drilling nanoholes in colloidal spheres by selective etching

Abstract

An effective route for the fabrication of arrays of polystyrene (PS) colloidal spheres with nanoholes by selective etching of a colloidal monolayer partially embedded in an electrochemically deposited nickle layer was investigated. It was observed that after removal of the nickel layer by using wet chemical etching with dilute hydrochloric acid, an array of PS colloidal speres with nanoholes was obstained. It was shown that in addition to the size tuning by electrochemical deposition of nickle layers of different thicknesses, the depth of the holes can also be tuned by controlling the ICP etching time. It was found that this fabrication method allows the simple and reliable production of arrays of colloidal spheres with nanoholes.