Physicochemical Modulation of Nanometer-Thick Etalon Films for Liquid-Sensitive Color Display with Full-Color Spectrum Generation

Light–matter interactions based on noble metal nanostructures have received continued attention for their tremendous potential for the discovery of basic science as well as their application in practical devices driven by their unique optical characteristics. However, constructing such nanostructured platforms requires relatively expensive and complicated fabrication processes to produce a wide range of colors in the visible region. In this paper, we propose a simple nanoscale Fabry–Perot film capable of providing full-color coverage in the visible region with a high level of color tunability through engineering the geometries of the constituent layers. Specifically, the thicknesses and filling-fractions of each layer were precisely tailored to allow for fine color tuning together with theoretical modeling to set up a standard guideline of structural colors depending on such physical variables. The physicochemical property-dependent coloration was demonstrated via the simple nanometer-thick Fabry–Perot stack, which was further applied to functional mimicry of environmental sensitive optical camouflage.