title: Current path in light emitting diodes based on nanowire ensembles.
abstract: Light emitting diodes (LEDs) have been fabricated using ensembles of free-standing (In, Ga)N/GaN nanowires (NWs) grown on Si substrates in the self-induced growth mode by molecular beam epitaxy. Electron-beam-induced current analysis, cathodoluminescence as well as biased μ-photoluminescence spectroscopy, transmission electron microscopy, and electrical measurements indicate that the electroluminescence of such LEDs is governed by the differences in the individual current densities of the single-NW LEDs operated in parallel, i.e. by the inhomogeneity of the current path in the ensemble LED. In addition, the optoelectronic characterization leads to the conclusion that these NWs exhibit N-polarity and that the (In, Ga)N quantum well states in the NWs are subject to a non-vanishing quantum confined Stark effect.
authors.affiliation: Paul-Drude-Institut für Festkörperelektronik, Hausvogteiplatz 5-7, D-10117 Berlin, Germany.
authors.forename: F
authors.initials: F
authors.lastname: Limbach
authors.forename: C
authors.initials: C
authors.lastname: Hauswald
authors.forename: J
authors.initials: J
authors.lastname: Lähnemann
authors.forename: M
authors.initials: M
authors.lastname: Wölz
authors.forename: O
authors.initials: O
authors.lastname: Brandt
authors.forename: A
authors.initials: A
authors.lastname: Trampert
authors.forename: M
authors.initials: M
authors.lastname: Hanke
authors.forename: U
authors.initials: U
authors.lastname: Jahn
authors.forename: R
authors.initials: R
authors.lastname: Calarco
authors.forename: L
authors.initials: L
authors.lastname: Geelhaar
authors.forename: H
authors.initials: H
authors.lastname: Riechert