title: Ultralong and defect-free GaN nanowires grown by the HVPE process.
abstract: GaN nanowires with exceptional lengths are synthesized by vapor-liquid-solid coupled with near-equilibrium hydride vapor phase epitaxy technique on c-plane sapphire substrates. Because of the high decomposition frequency of GaCl precursors and a direct supply of Ga through the catalyst particle, the growth of GaN nanowires with constant diameters takes place at an exceptional growth rate of 130 μm/h. The chemical composition of the catalyst droplet is analyzed by energy dispersive X-ray spectroscopy. High-resolution transmission electron microscopy and selective area diffraction show that the GaN nanowires crystallize in the hexagonal wurzite structure and are defect-free. GaN nanowires exhibit bare top facets without any droplet. Microphotoluminescence displays a narrow and intense emission line (1 meV line width) associated to the neutral-donor bound exciton revealing excellent optical properties of GaN nanowires.
authors.affiliation: Clermont Université, Université Blaise Pascal, Institut Pascal, BP 10448, F-63000 Clermont-Ferrand, France.
authors.forename: Geoffrey
authors.initials: G
authors.lastname: Avit
authors.forename: Kaddour
authors.initials: K
authors.lastname: Lekhal
authors.forename: Yamina
authors.initials: Y
authors.lastname: André
authors.forename: Catherine
authors.initials: C
authors.lastname: Bougerol
authors.forename: François
authors.initials: F
authors.lastname: Réveret
authors.forename: Joël
authors.initials: J
authors.lastname: Leymarie
authors.forename: Evelyne
authors.initials: E
authors.lastname: Gil
authors.forename: Guillaume
authors.initials: G
authors.lastname: Monier
authors.forename: Dominique
authors.initials: D
authors.lastname: Castelluci
authors.forename: Agnès
authors.initials: A
authors.lastname: Trassoudaine