Flexible tuning of the peak wavelength and intensity of localized surface plasmon resonance by heat treatment of nanodisk structures fabricated by electron beam lithography

Abstract

We demonstrate that the plasmonic properties of Au nanodisk structures fabricated by an electron beam lithography can be improved by very simple heat treatments, and that the resonance wavelength can be tuned by temperature. With a Ni adhesion layer, the resonance peak increased and blue-shifted due to improvement of metal quality without changing the sizes of nanostructures, while without the adhesion layer, the resonance wavelength can be tuned over a wider wavelength range by intentionally reducing the size of nanostructures through annealing. For Ag nanodisks with the adhesive layer, the plasmon resonance wavelength was blue-shifted due to the size reduction of nanodisks through thermal annealing. Full-color tuning of plasmonic resonance should be possible by controlling the diameter and height of Ag nanodisks under appropriate temperature conditions of heat treatment.