title: High degree of polarization of the near-band-edge photoluminescence in ZnO nanowires.
abstract: We investigated the polarization dependence of the near-band-edge photoluminescence in ZnO strain-free nanowires grown by vapor phase technique. The emission is polarized perpendicular to the nanowire axis with a large polarization ratio (as high as 0.84 at 4.2 K and 0.63 at 300 K). The observed polarization ratio is explained in terms of selection rules for excitonic transitions derived from the k·p theory for ZnO. The temperature dependence of the polarization ratio evidences a gradual activation of the XC excitonic transition.PACS: 78.55.Cr, 77.22.Ej, 81.07.Gf.
authors.affiliation: Institut d'Electronique Fondamentale, Université Paris Sud XI, UMR 8622 CNRS, 91405 Orsay, France. gwenole.jacopin@ief.u-psud.fr.
authors.forename: Gwenole
authors.initials: G
authors.lastname: Jacopin
authors.forename: Lorenzo
authors.initials: L
authors.lastname: Rigutti
authors.forename: Andres De Luna
authors.initials: Ade L
authors.lastname: Bugallo
authors.forename: François Henry
authors.initials: FH
authors.lastname: Julien
authors.forename: Camilla
authors.initials: C
authors.lastname: Baratto
authors.forename: Elisabetta
authors.initials: E
authors.lastname: Comini
authors.forename: Matteo
authors.initials: M
authors.lastname: Ferroni
authors.forename: Maria
authors.initials: M
authors.lastname: Tchernycheva