Original Article

Citation: Light: Science & Applications (2017) 6, e17015; doi:10.1038/lsa.2017.15
Published online 14 July 2017

Scalable and controlled self-assembly of aluminum-based random plasmonic metasurfaces
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Radwanul Hasan Siddique1,2,, Jan Mertens3, Hendrik Hölscher1 and Silvia Vignolini2

  1. 1Institute for Microstructure Technology, Karlsruhe Institute of Technology (KIT), Hermann-von-Helmholtz-Platz 1, Eggenstein-Leopoldshafen, Karlsruhe 76344, Germany
  2. 2Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, UK
  3. 3Department of Physics, NanoPhotonics Group, Kapitza Building, Cavendish Laboratory, University of Cambridge, Cambridge CB3 0HE, UK

Correspondence: RH Siddique, Email: rhs@caltech.edu; S Vignolini, Email: sv319@cam.ac.uk

Present address: Department of Medical Engineering, California Institute of Technology (Caltech), B127 Moore Laboratory, MC 136-93, Pasadena, CA 91125, USA.

Received 15 August 2016; Revised 31 January 2017; Accepted 15 February 2017
Accepted article preview online 17 February 2017

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Abstract

Subwavelength metal-dielectric plasmonic metasurfaces enable light management beyond the diffraction limit. However, a cost-effective and reliable fabrication method for such structures remains a major challenge hindering their full exploitation. Here, we propose a simple yet powerful manufacturing route for plasmonic metasurfaces based on a bottom-up approach. The fabricated metasurfaces consist of a dense distribution of randomly oriented nanoscale scatterers composed of aluminum (Al) nanohole-disk pairs, which exhibit angle-independent scattering that is tunable across the entire visible spectrum. The macroscopic response of the metasurfaces is controlled via the properties of an isolated Al nanohole-disk pair at the nanoscale. In addition, the optical field confinement at the scatterers and their random distribution of sizes result in a strongly enhanced Raman signal that enables broadly tunable excitation using a single substrate. This unique combination of a reliable and lithography-free methodology with the use of aluminum permits the exploitation of the full potential of random plasmonic metasurfaces for diagnostics and coloration.

Keywords:

aluminum plasmonics; plasmonic metasurfaces; polymer blends; self-assembly; SERS; structural color