Welcome to the new version of CaltechAUTHORS. Login is currently restricted to library staff. If you notice any issues, please email coda@library.caltech.edu
Published May 5, 2014 | Published
Journal Article Open

Near-unity broadband absorption designs for semiconducting nanowire arrays via localized radial mode excitation


We report design methods for achieving near-unity broadband light absorption in sparse nanowire arrays, illustrated by results for visible absorption in GaAs nanowires on Si substrates. Sparse (<5% fill fraction) nanowire arrays achieve near unity absorption at wire resonant wavelengths due to coupling into 'leaky' radial waveguide modes of individual wires and wire-wire scattering processes. From a detailed conceptual development of radial mode resonant absorption, we demonstrate two specific geometric design approaches to achieve near unity broadband light absorption in sparse nanowire arrays: (i) introducing multiple wire radii within a small unit cell array to increase the number of resonant wavelengths, yielding a 15% absorption enhancement relative to a uniform nanowire array and (ii) tapering of nanowires to introduce a continuum of diameters and thus resonant wavelengths excited within a single wire, yielding an 18% absorption enhancement over a uniform nanowire array.

Additional Information

© 2014 Optical Society of America. Received 10 Feb 2014; revised 6 Apr 2014; accepted 6 Apr 2014; published 18 Apr 2014. This material is based upon work performed by the Joint Center for Artificial Photosynthesis, a DOE Energy Innovation Hub, supported through the Office of Science of the U.S. Department of Energy under Award No. DE-SC0004993. K.T.F. is supported by the National Science Foundation Graduate Research Fellowship under Grant No. DGE-1144469. C.G.K. was supported by a Caltech Summer Undergraduate Research Fellowship.

Attached Files

Published - oe-22-S3-A930.pdf


Files (3.2 MB)
Name Size Download all
3.2 MB Preview Download

Additional details

August 20, 2023
October 26, 2023