title: High-Efficiency Nanowire Solar Cells with Omnidirectionally Enhanced Absorption Due to Self-Aligned Indium-Tin-Oxide Mie Scatterers.
abstract: Photovoltaic cells based on arrays of semiconductor nanowires promise efficiencies comparable or even better than their planar counterparts with much less material. One reason for the high efficiencies is their large absorption cross section, but until recently the photocurrent has been limited to less than 70% of the theoretical maximum. Here we enhance the absorption in indium phosphide (InP) nanowire solar cells by employing broadband forward scattering of self-aligned nanoparticles on top of the transparent top contact layer. This results in a nanowire solar cell with a photovoltaic conversion efficiency of 17.8% and a short-circuit current of 29.3 mA/cm2under 1 sun illumination, which is the highest reported so far for nanowire solar cells and among the highest reported for III-V solar cells. We also measure the angle-dependent photocurrent, using time-reversed Fourier microscopy, and demonstrate a broadband and omnidirectional absorption enhancement for unpolarized light up to 60° with a wavelength average of 12% due to Mie scattering. These results unambiguously demonstrate the potential of semiconductor nanowires as nanostructures for the next generation of photovoltaic devices.
authors.affiliation: Department of Applied Physics, Eindhoven University of Technology , P.O. Box 513, 5600 MB Eindhoven, The Netherlands.
authors.forename: Dick
authors.identifier: 0000-0002-3265-8822
authors.initials: D
authors.lastname: van Dam
authors.affiliation: Department of Applied Physics, Eindhoven University of Technology , P.O. Box 513, 5600 MB Eindhoven, The Netherlands.|Dutch Institute for Fundamental Energy Research DIFFER , P.O. Box 6336, 5600 HH Eindhoven, The Netherlands.
authors.forename: Niels J J
authors.initials: NJ
authors.lastname: van Hoof
authors.affiliation: Department of Applied Physics, Eindhoven University of Technology , P.O. Box 513, 5600 MB Eindhoven, The Netherlands.
authors.forename: Yingchao
authors.initials: Y
authors.lastname: Cui
authors.affiliation: Department of Applied Physics, Eindhoven University of Technology , P.O. Box 513, 5600 MB Eindhoven, The Netherlands.
authors.forename: Peter J
authors.initials: PJ
authors.lastname: van Veldhoven
authors.affiliation: Department of Applied Physics, Eindhoven University of Technology , P.O. Box 513, 5600 MB Eindhoven, The Netherlands.|Kavli Institute of Nanoscience, Delft University of Technology , 2600 GA Delft, The Netherlands.
authors.forename: Erik P A M
authors.identifier: 0000-0002-8264-6862
authors.initials: EP
authors.lastname: Bakkers
authors.affiliation: Department of Applied Physics, Eindhoven University of Technology , P.O. Box 513, 5600 MB Eindhoven, The Netherlands.|Dutch Institute for Fundamental Energy Research DIFFER , P.O. Box 6336, 5600 HH Eindhoven, The Netherlands.
authors.forename: Jaime
authors.initials: J
authors.lastname: Gómez Rivas
authors.affiliation: Department of Applied Physics, Eindhoven University of Technology , P.O. Box 513, 5600 MB Eindhoven, The Netherlands.
authors.forename: Jos E M
authors.initials: JE
authors.lastname: Haverkort
keywords: InP; Mie scattering; absorption; efficiency; nanowires; photovoltaics; solar cells