Near‐Ultraviolet Structural Colors Generated by Aluminum Nanodisk Array for Bright Image Printing

Abstract Structural colors generated by optical micro‐ or nanostructures have attracted much attention for replacing pigment colors due to their tunability and semipermanency. The advantages of structural colors are now ready to be extended to the spectral range outside that of visible wavelengths. Here, bright structural colors are demonstrated in the near‐ultraviolet (near‐UV) wavelength range based on the plasmonic resonance of an aluminum nanodisk array. Collective plasmonic oscillation of the aluminum nanodisks selectively reflects the near‐UV light with a high reflectance and narrow linewidth. The color of the reflected light is tuned over the full near‐UV range, depending on the structural parameters of the nanodisk array. In particular, aluminum nanodisk arrays can be used as structural color pixels that demonstrate printing of near‐UV images with a high resolution of ≈10 000 pixels per inch. The demonstrated near‐UV structural colors show significant progress toward UV filtering and imaging, anticounterfeit, color multiplexing, and photocatalysis.