Chromatic limits of color filters based on gold nanostructure arrays: The role of surface plasmon and bulk contributions

Abstract

Localized surface plasmons (LSPs) of metallic nanostructure arrays have been recognized as an optical tool in the design of color filters by improving color gamut, saturation, and mechanical stability. In the reflectance spectra of these types of arrays, which define color, LSP and bulk contributions co-exist, and even though there have been numerous reports in this field, the chromatic limits of both contributions have not been reported. In this study, we investigate the relative contributions of LSP and bulk to the color of arrays. Using numerical simulations, the reflectance spectra of hexagonal arrays of gold nanodisks are investigated in terms of the dimensionality of the array. With a phenomenological approach based on the fitting of reflectance spectra with Gaussian and baseline functions, LSP and bulk contributions to color are separated and quantified. The results unveil the crossover between the yellowish color of gold, the signature of bulk concentration, and the reddish color of nanostructures.