KIEL, Germany, Feb. 7, 2014 — A new approach to tunable plasmonic metamaterials for high UV frequencies could pave the way for their application in UV-protective coatings, as well as thermophotovoltaics and stealth technology. Researchers in Germany have designed a tunable plasmonic metamaterial super absorber (PMSA) that can function as a UV-protective film. Typically, plasmonic metamaterials designed for optical frequency must be shrunk down to a few tenths of a nanometer, making their manufacturing cumbersome. In this study, researchers designed and fabricated a tunable silver-SiO2 nanocomposite on a highly reflective substrate by tandem co-deposition to create a PMSA that can operate at UV and UV-A frequencies. An ultrathin film was deposited where the two layers separated, allowing a dielectric layer to act as a super absorber for different frequencies. This approach offers ease of fabrication and low production costs, and it offers high efficiency in absorption intensity and angular sensitivity. To demonstrate the feasibility of their work, the researchers compared the performance of their new design with that of an organic counterpart. A dye molecule incorporated into a polymer matrix film was deposited on optically thick silver film as a UV absorber, and the absorption intensity and bandwidth were both collated. The absorption intensity in the UV and visible range of the PMSA system is twice that of an organic one. The work is published in Scitation. For more information, visit www.uni-kiel.de.