title: Tailoring Charge Recombination in Photoelectrodes Using Oxide Nanostructures.
abstract: Optimizing semiconductor devices for solar energy conversion requires an explicit control of the recombination of photogenerated electron-hole pairs. Here we show how the recombination of charge carriers can be controlled in semiconductor thin films by surface patterning with oxide nanodisks. The control mechanism relies on the formation of dipole-like electric fields at the interface that, depending on the field direction, attract or repel minority carriers from underneath the disks. The charge recombination rate can be controlled through the choice of oxide material and the surface coverage of nanodisks. We provide proof-of-principle demonstration of this approach by patterning the surface of Fe2O3, one of the most studied semiconductors for light-driven water splitting, with TiO2 and Cu2O nanodisks. We expect this method to be generally applicable to a range of semiconductor-based solar energy conversion devices.
authors.affiliation: Department of Physics, Chalmers University of Technology , 412 96 Göteborg, Sweden.|Center for Electron Nanoscopy, Technical University of Denmark , 2800 Kongens Lyngby, Denmark.
authors.forename: Beniamino
authors.initials: B
authors.lastname: Iandolo
authors.affiliation: Department of Physics, Chalmers University of Technology , 412 96 Göteborg, Sweden.
authors.forename: Björn
authors.initials: B
authors.lastname: Wickman
authors.affiliation: Department of Physics, Chalmers University of Technology , 412 96 Göteborg, Sweden.
authors.forename: Elin
authors.initials: E
authors.lastname: Svensson
authors.affiliation: Department of Physics, Chalmers University of Technology , 412 96 Göteborg, Sweden.
authors.forename: Daniel
authors.initials: D
authors.lastname: Paulsson
authors.affiliation: Department of Physics, Chalmers University of Technology , 412 96 Göteborg, Sweden.
authors.forename: Anders
authors.initials: A
authors.lastname: Hellman
keywords: Energy conversion; charge recombination; hematite; photoelectrodes; water splitting