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Published October 2011 | public
Journal Article

Broadband polarization-independent resonant light absorption using ultrathin plasmonic super absorbers


Resonant plasmonic and metamaterial structures allow for control of fundamental optical processes such as absorption, emission and refraction at the nanoscale. Considerable recent research has focused on energy absorption processes, and plasmonic nanostructures have been shown to enhance the performance of photovoltaic and thermophotovoltaic cells. Although reducing metallic losses is a widely sought goal in nanophotonics, the design of nanostructured 'black' super absorbers from materials comprising only lossless dielectric materials and highly reflective noble metals represents a new research direction. Here we demonstrate an ultrathin (260 nm) plasmonic super absorber consisting of a metal–insulator–metal stack with a nanostructured top silver film composed of crossed trapezoidal arrays. Our super absorber yields broadband and polarization-independent resonant light absorption over the entire visible spectrum (400–700 nm) with an average measured absorption of 0.71 and simulated absorption of 0.85. Proposed nanostructured absorbers open a path to realize ultrathin black metamaterials based on resonant absorption.

Additional Information

© 2011 Macmillan Publishers Limited. Received 10 August 2010. Accepted 04 October 2011. Published 01 November 2011. This work was primarily supported by the DOE Office of Basic Energy Sciences 'Light-Material Interactions in Energy Conversion' Energy Frontier Research Center under grant DE-SC0001293 (H.A.A. and K.A.), and also by the Air Force Office of Scientific Research under grant FA9550-09-1-0673 (R.M.B.) and by the Office of Basic Energy Sciences Materials Sciences under DE-FG02-07ER46405 (V.E.F.). Portions of this work were performed in facilities sponsored by the Center for Science and Engineering of Materials, an NSF MRSEC. We gratefully acknowledge the critical support and infrastructure provided for this work by the Kavli Nanoscience Institute at Caltech. We thank Deirdre O'Carroll, Ragip Pala, Carrie E. Hofmann and Imogen M. Pryce for technical assistance and helpful discussions. Author contributions: K.A. conceived the idea and performed the experiments. K.A. and V.E.F. performed the full-field electromagnetic simulations, and K.A. and R.M.B. fabricated the samples. K.A., V.E.F. and H.A.A. analysed the data and wrote the paper.

Additional details

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October 24, 2023