Optical Properties of Multilayer Ordered Gold Nanodot Array Fabricated by a Thermal Dewetting Method

A new efficient and low-cost method to fabricate multilayer ordered nanodot array is developed. In this method, firstly, a 2D nanodot array is fabricated by combination of Nano Plastic Forming (NPF) patterning of Au layer coated on the substrate and thermal dewetting induced self-organization. Then, multilayer ordered Au nanodot array is fabricated by repeating SiO2 deposition and Au deposition followed by thermal dewetting. Feasibility of this process was verified experimentally. The absorbance spectra of the fabricated ordered Au nanodot arrays show strong localized surface plasmon resonance (LSPR) with narrow bandwidth. It is shown that the absorbance spectra of a 2D nanodot array can be tuned by controlling annealing temperature. It is also found that intensity of the absorbance spectrum increases linearly with the increase of the number of layers. This enhanced absorbance gives rise to great potential in biosensing devices.