title: Epitaxy of GaN Nanowires on Graphene.
abstract: Epitaxial growth of GaN nanowires on graphene is demonstrated using molecular beam epitaxy without any catalyst or intermediate layer. Growth is highly selective with respect to silica on which the graphene flakes, grown by chemical vapor deposition, are transferred. The nanowires grow vertically along their c-axis and we observe a unique epitaxial relationship with the ⟨21̅1̅0⟩ directions of the wurtzite GaN lattice parallel to the directions of the carbon zigzag chains. Remarkably, the nanowire density and height decrease with increasing number of graphene layers underneath. We attribute this effect to strain and we propose a model for the nanowire density variation. The GaN nanowires are defect-free and they present good optical properties. This demonstrates that graphene layers transferred on amorphous carrier substrates is a promising alternative to bulk crystalline substrates for the epitaxial growth of high quality GaN nanostructures.
authors.affiliation: Laboratoire de Photonique et de Nanostructures (LPN), CNRS, Université Paris-Saclay, Route de Nozay , F-91460 Marcoussis, France.
authors.forename: Vishnuvarthan
authors.initials: V
authors.lastname: Kumaresan
authors.affiliation: Laboratoire de Photonique et de Nanostructures (LPN), CNRS, Université Paris-Saclay, Route de Nozay , F-91460 Marcoussis, France.
authors.forename: Ludovic
authors.initials: L
authors.lastname: Largeau
authors.affiliation: Laboratoire de Photonique et de Nanostructures (LPN), CNRS, Université Paris-Saclay, Route de Nozay , F-91460 Marcoussis, France.
authors.forename: Ali
authors.initials: A
authors.lastname: Madouri
authors.affiliation: Laboratoire de Photonique et de Nanostructures (LPN), CNRS, Université Paris-Saclay, Route de Nozay , F-91460 Marcoussis, France.
authors.forename: Frank
authors.initials: F
authors.lastname: Glas
authors.affiliation: Institut d'Electronique Fondamentale, UMR 8622 CNRS, University Paris Sud, University Paris-Saclay , 91405 Orsay cedex, France.
authors.forename: Hezhi
authors.initials: H
authors.lastname: Zhang
authors.affiliation: Laboratoire de Photonique et de Nanostructures (LPN), CNRS, Université Paris-Saclay, Route de Nozay , F-91460 Marcoussis, France.
authors.forename: Fabrice
authors.initials: F
authors.lastname: Oehler
authors.affiliation: Laboratoire de Photonique et de Nanostructures (LPN), CNRS, Université Paris-Saclay, Route de Nozay , F-91460 Marcoussis, France.
authors.forename: Antonella
authors.initials: A
authors.lastname: Cavanna
authors.affiliation: Institut d'Electronique Fondamentale, UMR 8622 CNRS, University Paris Sud, University Paris-Saclay , 91405 Orsay cedex, France.|ITMO University , St. Petersburg 197101, Russia.
authors.forename: Andrey
authors.initials: A
authors.lastname: Babichev
authors.affiliation: Laboratoire de Photonique et de Nanostructures (LPN), CNRS, Université Paris-Saclay, Route de Nozay , F-91460 Marcoussis, France.
authors.forename: Laurent
authors.initials: L
authors.lastname: Travers
authors.affiliation: Laboratoire de Photonique et de Nanostructures (LPN), CNRS, Université Paris-Saclay, Route de Nozay , F-91460 Marcoussis, France.
authors.forename: Noelle
authors.initials: N
authors.lastname: Gogneau
authors.affiliation: Institut d'Electronique Fondamentale, UMR 8622 CNRS, University Paris Sud, University Paris-Saclay , 91405 Orsay cedex, France.
authors.forename: Maria
authors.initials: M
authors.lastname: Tchernycheva
authors.affiliation: Laboratoire de Photonique et de Nanostructures (LPN), CNRS, Université Paris-Saclay, Route de Nozay , F-91460 Marcoussis, France.
authors.forename: Jean-Christophe
authors.initials: JC
authors.lastname: Harmand
keywords: GaN; Gallium nitride; TEM; graphene substrate; nanowires; photoluminescence