Structural Color Materials with Color Mixing Effect Using Noble Metal‐Free Plasmonic Particles in SiO2–ZrN System

Abstract

AbstractStructurally colored materials with a color mixing effect are developed using SiO2–ZrN core–shell particles, where ZrN nanoparticles used as shells exhibited localized surface plasmon resonances (LSPRs). ZrN nanoparticles (10–30 nm) are attached to monodispersed SiO2 particles by modifying SiO2 particles with polymers. The attached ZrN nanoparticles exhibited a plasmon resonance absorption band at 700 nm. These SiO2–ZrN core–shell particles have a highly monodisperse particle size and assemble into a particle‐stacked film with Bragg diffraction light in the visible spectrum. The particle‐stacked film of the SiO2–ZrN core–shell particles exhibited the maximum reflection depending on the particle size of the SiO2 core. The ratio of the reflection intensity in the long‐wavelength region corresponding to the ZrN absorption to that in the short‐wavelength region of the particle‐stacked film containing the ZrN shell is less than that of the ratio in only SiO2 particle‐stacked film. The results reveal that these particle‐stacked films exhibit a “color mixing effect” that combines specific wavelength absorption through plasmon resonance and specific wavelength diffraction owing to the periodic structure without using precious metals.