Long-lived excitons in GaN/AlN nanowire heterostructures
Beeler, Mark (Commissariat à l'Énergie Atomique et aux Énergies Alternatives (França))
Lim, Caroline B. (Commissariat à l'Énergie Atomique et aux Énergies Alternatives (França))
Hille, Pascal (Justus-Liebig-Universität Giessen. Physikalisches Institut)
Bleuse, Joel (Commissariat à l'Énergie Atomique et aux Énergies Alternatives (França))
Schörmann, Jörg (Justus-Liebig-Universität Giessen. Physikalisches Institut)
De La Mata, Maria (Institut de Ciència de Materials de Barcelona)
Arbiol i Cobos, Jordi (Institut Català de Nanociència i Nanotecnologia)
Eickhoff, Martin (Justus-Liebig-Universität Giessen. Physikalisches Institut)
Monroy, Eva (Commissariat à l'Énergie Atomique et aux Énergies Alternatives (França))

Date:	2015
Abstract:	GaN/AlN nanowire heterostructures can display photoluminescence (PL) decay times on the order of microseconds that persist up to room temperature. Doping the GaN nanodisk insertions with Ge can reduce these PL decay times by two orders of magnitude. These phenomena are explained by the three-dimensional electric field distribution within the GaN nanodisks, which has an axial component in the range of a few MV/cm associated to the spontaneous and piezoelectric polarization, and a radial piezoelectric contribution associated to the shear components of the lattice strain. At low dopant concentrations, a large electron-hole separation in both the axial and radial directions is present. The relatively weak radial electric fields, which are about one order of magnitude smaller than the axial fields, are rapidly screened by doping. This bidirectional screening leads to a radial and axial centralization of the hole underneath the electron, and consequently, to large decreases in PL decay times, in addition to luminescence blue shifts.
Grants:	European Commission 278428 Ministerio de Economía y Competitividad MAT2014-51480-ERC Agència de Gestió d'Ajuts Universitaris i de Recerca 2014/SGR-1638
Rights:	Aquest document està subjecte a una llicència d'ús Creative Commons. Es permet la reproducció total o parcial, la distribució, la comunicació pública de l'obra i la creació d'obres derivades, fins i tot amb finalitats comercials, sempre i quan es reconegui l'autoria de l'obra original.
Language:	Anglès
Document:	Article ; recerca ; Versió publicada
Published in:	Physical review B : Condensed matter and materials physics, Vol. 91, issue 20 (May 2015) , art. 205440, ISSN 1550-235X

DOI: 10.1103/PhysRevB.91.205440

8 p, 2.1 MB

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Research literature > UAB research groups literature > Research Centres and Groups (research output) > Experimental sciences > Catalan Institute of Nanoscience and Nanotechnology (ICN2)
Articles > Research articles
Articles > Published articles