title: Self-assembled GaN quantum wires on GaN/AlN nanowire templates.
abstract: We present a novel approach for self-assembled growth of GaN quantum wires (QWRs) exhibiting strong confinement in two spatial dimensions. The GaN QWRs are formed by selective nucleation on {112[combining macron]0} (a-plane) facets formed at the six intersections of {11[combining macron]00} (m-plane) sidewalls of AlN/GaN nanowires used as a template. Based on microscopy observations we have developed a 3D model explaining the growth mechanism of QWRs. We show that the QWR formation is governed by self-limited pseudomorphic growth on the side facets of the nanowires (NWs). Quantum confinement in the QWRs is confirmed by the observation of narrow photoluminescence lines originating from individual QWRs with emission energies up to 4.4 eV. Time-resolved photoluminescence studies reveal a short decay time (~120 ps) of the QWR emission. Capping of the QWRs with AlN allows enhancement of the photoluminescence, which is blue-shifted due to compressive strain. The emission energies from single QWRs are modelled assuming a triangular cross-section resulting from self-limited growth on a-plane facets. Comparison with the experimental results yields an average QWR diameter of about 2.7 nm in agreement with structural characterization. The presented results open a new route towards controlled realization of one-dimensional semiconductor quantum structures with a high potential both for fundamental studies and for applications in electronics and in UV light generation.
authors.affiliation: Institució Catalana de Recerca i Estudis Avançats (ICREA) and Institut de Ciència de Materials de Barcelona, ICMAB-CSIC, Campus de la UAB, E-08193 Bellaterra, CAT, Spain. arbiol@icrea.cat
authors.forename: Jordi
authors.initials: J
authors.lastname: Arbiol
authors.forename: Cesar
authors.initials: C
authors.lastname: Magen
authors.forename: Pascal
authors.initials: P
authors.lastname: Becker
authors.forename: Gwénolé
authors.initials: G
authors.lastname: Jacopin
authors.forename: Alexey
authors.initials: A
authors.lastname: Chernikov
authors.forename: Sören
authors.initials: S
authors.lastname: Schäfer
authors.forename: Florian
authors.initials: F
authors.lastname: Furtmayr
authors.forename: Maria
authors.initials: M
authors.lastname: Tchernycheva
authors.forename: Lorenzo
authors.initials: L
authors.lastname: Rigutti
authors.forename: Jörg
authors.initials: J
authors.lastname: Teubert
authors.forename: Sangam
authors.initials: S
authors.lastname: Chatterjee
authors.forename: Joan R
authors.initials: JR
authors.lastname: Morante
authors.forename: Martin
authors.initials: M
authors.lastname: Eickhoff