Self‐Assembled Plasmonic Coaxial Nanocavities for High‐Definition Broad‐Angle Coloring in Reflection and Transmission

Resonant spectral scattering from metallic nanostructures is an attractive alternative approach to produce colors instead of using chemical pigments. Here, a technological platform based on self-assembled arrays of coaxial plasmonic resonators is developed for generating a bright color gamut over the entire visible spectral range in both reflection and transmission, offering the potential for ultrahigh definition coloring over large areas. Unlike the approaches using the nanostructure periodicity to define colors, the developed method employs color engineering based on the localized plasmon resonances in nanocavities, therefore, providing a broad angular response and viewing angles of up to 40 degrees. With the nanoscale dimensions of color pixels and an increased viewing angle range, the proposed approach allows achieving large-area color patterns with local coloring controlled by postprocessing, important for display technology, anticounterfeiting and artistic applications.