Authors J.S. Clausen and colleagues, from the University of Denmark, report on a novel way to implement structural colors into plastic products for daily consumer use.  Structural colors offer some significant advantages over current pigment-based coloring by reducing the materials needed and new opportunities for recycling and sustainability.  The authors create structural colors here from metal disks on top of dielectric pillars that are hovering above a holey metal film composed of aluminum. They then use the dispersion of the surface plasmon polaritons (SPPs) supported by the metal-dielectric interface of the holey film to generate the colors; a schematic of the structure is shown below where the final protective coating is then added to minimize environmental contamination.  By using aluminum (instead of gold or silver), the SPPs supported by aluminum to improve the angle independence in the color observation, as well as other improvements.  The authors use a dual probe Multiview 4000 to characterize the SPP modes with excitation probe with a 100nm aperture diameter held fixed and a detection probe with a 200nm aperture diameter scanned away from the excitation.

Published:  Nano Letters 2014, 14, 4499-4504

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