Silicon Nanostructures for Bright Field Full Color Prints

Nanoscale color printing has recently emerged as a unique alternative to traditional pigments by providing record spatial resolution, angular independent, durable and single material colors. Widely based on plasmonic nanostructures, numerous efforts in the field have aimed at extending color range and saturation relying on a variety of designs and metals. Alternatively, silicon nanostructures support finely tunable electric and magnetic multipolar resonances, afford low absorption losses and benefit from well-established industrial fabrication processes, all features ideally suited to nanoscale color printing. Here we compare the properties of silicon nanodiscs with those of aluminum and silver plasmonic elements for the specific purpose of nanoscale color reproduction targeting the coverage of a broad and vivid color palette. We highlight the different properties of such metallic and dielectric resonators in various geometric and illumination conditions leading to the optimization of silicon nanodisc arrays for the fabrication of high resolution color features as well as millimetric paining replicas. The fabricated structures span a large, continuous color range with varying hue and saturation that is visible by conventional optical microscopy, photography as well as the bare eye under white light illumination. High-throughput electron beam lithography as well as color mixing schemes are discussed to further harness the unique properties of silicon nanodiscs as color elements, paving the way for a broader exploitation of nanoscale color printing.