title: X-ray Bragg Ptychography on a Single InGaN/GaN Core-Shell Nanowire.
abstract: The future of solid-state lighting can be potentially driven by applications of InGaN/GaN core-shell nanowires. These heterostructures provide the possibility for fine-tuning of functional properties by controlling a strain state between mismatched layers. We present a nondestructive study of a single 400 nm-thick InGaN/GaN core-shell nanowire using two-dimensional (2D) X-ray Bragg ptychography (XBP) with a nanofocused X-ray beam. The XBP reconstruction enabled the determination of a detailed three-dimensional (3D) distribution of the strain in the particular nanowire using a model based on finite element method. We observed the strain induced by the lattice mismatch between the GaN core and InGaN shell to be in the range from -0.1% to 0.15% for an In concentration of 30%. The maximum value of the strain component normal to the facets was concentrated at the transition region between the main part of the nanowire and the GaN tip. In addition, a variation in misfit strain relaxation between the axial growth and in-plane directions was revealed.
authors.affiliation: Deutsches Elektronen-Synchrotron DESY , Notkestraße 85, D-22607 Hamburg, Germany.
authors.forename: Dmitry
authors.identifier: 0000-0001-8398-9480
authors.initials: D
authors.lastname: Dzhigaev
authors.affiliation: Niels Bohr Institute, University of Copenhagen , Blegdamsvej 17, 2100 Copenhagen, Denmark.
authors.forename: Tomaš
authors.initials: T
authors.lastname: Stankevič
authors.affiliation: NanoLund, Department of Physics, Lund University , P.O. Box 118, SE-221 00 Lund, Sweden.
authors.forename: Zhaoxia
authors.initials: Z
authors.lastname: Bi
authors.affiliation: Deutsches Elektronen-Synchrotron DESY , Notkestraße 85, D-22607 Hamburg, Germany.|National Research Tomsk Polytechnic University (TPU) , pr. Lenina 30, 634050 Tomsk, Russia.
authors.forename: Sergey
authors.initials: S
authors.lastname: Lazarev
authors.affiliation: Deutsches Elektronen-Synchrotron DESY , Notkestraße 85, D-22607 Hamburg, Germany.
authors.forename: Max
authors.initials: M
authors.lastname: Rose
authors.affiliation: Deutsches Elektronen-Synchrotron DESY , Notkestraße 85, D-22607 Hamburg, Germany.
authors.forename: Anatoly
authors.initials: A
authors.lastname: Shabalin
authors.affiliation: Deutsches Elektronen-Synchrotron DESY , Notkestraße 85, D-22607 Hamburg, Germany.
authors.forename: Juliane
authors.initials: J
authors.lastname: Reinhardt
authors.affiliation: NanoLund, Department of Physics, Lund University , P.O. Box 118, SE-221 00 Lund, Sweden.
authors.forename: Anders
authors.initials: A
authors.lastname: Mikkelsen
authors.affiliation: NanoLund, Department of Physics, Lund University , P.O. Box 118, SE-221 00 Lund, Sweden.
authors.forename: Lars
authors.initials: L
authors.lastname: Samuelson
authors.affiliation: Deutsches Elektronen-Synchrotron DESY , Notkestraße 85, D-22607 Hamburg, Germany.
authors.forename: Gerald
authors.initials: G
authors.lastname: Falkenberg
authors.affiliation: Niels Bohr Institute, University of Copenhagen , Blegdamsvej 17, 2100 Copenhagen, Denmark.
authors.forename: Robert
authors.initials: R
authors.lastname: Feidenhans'l
authors.affiliation: Deutsches Elektronen-Synchrotron DESY , Notkestraße 85, D-22607 Hamburg, Germany.|National Research Nuclear University MEPhI (Moscow Engineering Physics Institute) , Kashirskoe shosse 31, 115409 Moscow, Russia.
authors.forename: Ivan A
authors.initials: IA
authors.lastname: Vartanyants
keywords: Bragg ptychography; Finite Element Method; GaN; InGaN; nanowire