title: Large-Scale Silicon Nanophotonic Metasurfaces with Polarization Independent Near-Perfect Absorption.
abstract: Optically thin perfect light absorbers could find many uses in science and technology. However, most physical realizations of perfect absorption for the optical range rely on plasmonic excitations in nanostructured metallic metasurfaces, for which the absorbed light energy is quickly lost as heat due to rapid plasmon decay. Here we show that a silicon metasurface excited in a total internal reflection configuration can absorb at least 97% of incident near-infrared light due to interferences between coherent electric and magnetic dipole scattering from the silicon nanopillars that build up the metasurface and the reflected wave from the supporting glass substrate. This "near-perfect" absorption phenomenon loads more than 50 times more light energy into the semiconductor than what would be the case for a uniform silicon sheet of equal surface density, irrespective of incident polarization. We envisage that the concept could be used for the development of novel light harvesting and optical sensor devices.
authors.affiliation: Department of Physics, Chalmers University of Technology , 412 96 Göteborg, Sweden.
authors.forename: Nils
authors.identifier: 0000-0003-1769-1082
authors.initials: N
authors.lastname: Odebo Länk
authors.affiliation: Department of Physics, Chalmers University of Technology , 412 96 Göteborg, Sweden.
authors.forename: Ruggero
authors.initials: R
authors.lastname: Verre
authors.affiliation: Department of Physics, Chalmers University of Technology , 412 96 Göteborg, Sweden.|School of Science and Technology, Örebro University , 701 82 Örebro, Sweden.
authors.forename: Peter
authors.initials: P
authors.lastname: Johansson
authors.affiliation: Department of Physics, Chalmers University of Technology , 412 96 Göteborg, Sweden.
authors.forename: Mikael
authors.initials: M
authors.lastname: Käll
keywords: Metasurfaces; colloidal lithography; high-index nanophotonics; perfect absorption