Abstract

The field of plasmonics has generated tremendous excitement in the last decade, because of its unique capabilities to focus light into deeply subwavelength volumes, leading to highly localized hot spots at extreme field intensities. In this study, we demonstrate a plasmonic absorber fabricated through self-assembly processes, which has an average measured absorbance of ~ 99% across the wavelengths from 400 nm to 20 µm, the most efficient and broadband plasmonic absorber reported so far. Solar steam generation based on it has over 90% efficiency under solar irradiation of only 4-sun intensity (4 kWm⁻²). Because of its superior absorption properties, strong field enhancement, unique porous structures together with scalable processes, we believe this type of plasmonic absorbers might find general usage for a variety of other applications from photo-catalysis, solar-thermoPV, solar desalination to infrared detectors.

© 2015 Optical Society of America