Interface-induced nucleation and growth: a new route for fabricating ordered silver nanohole arrays.

Metal nanohole arrays exhibit fascinating optical properties originating from the excitation of surface plasmons, and have been demonstrated to be of great potential in many applications. However, the fabrication of large-area ordered metal nanohole arrays with a tunable optical response is still highly desired. Herein, a novel interface-induced vapor phase growth method is developed to achieve hexagonally arranged silver nanohole arrays with a centimeter-scale area, in which an interface is introduced via an ordered template and used to induce Ag selective nucleation and growth. The adhesive force of the template with the substrate is found to be crucial in the determination of the nucleation sites and the resulting nanostructures. The plasmonic responses of the nanohole arrays are regulated by controlling their structural features, which are realized through simply changing the template parameters and the Ag deposition thickness. The Ag nanohole array exhibits more than 20-fold Raman enhancement compared to a rough Ag film when its localized surface plasmon resonance (LSPR) is tuned to an optimized range, which indicates its potential in biochemical sensing applications. The present method for the preparation of large-area metal nanohole arrays may open up a new avenue to fabricate novel metal nanostructures and develop high-performance plasmonic devices.