title: Evolution of polytypism in GaAs nanowires during growth revealed by time-resolved in situ x-ray diffraction.
abstract: In III-V nanowires the energetic barriers for nucleation in the zinc blende or wurtzite arrangement are typically of a similar order of magnitude. As a result, both arrangements can occur in a single wire. Here, we investigate the evolution of this polytypism in self-catalyzed GaAs nanowires on Si(111) grown by molecular beam epitaxy with time-resolved in situ x-ray diffraction. We interpret our data in the framework of a height dependent Markov model for the stacking in the nanowires. In this way, we extract the mean sizes of faultless wurtzite and zinc blende segments-a key parameter of polytypic nanowires-and their temporal evolution during growth. Thereby, we infer quantitative information on the differences of the nucleation barriers including their evolution without requiring a model of the nucleus.
authors.affiliation: Institute for Photon Science and Synchrotron Radiation, Karlsruhe Institute of Technology, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany.
authors.forename: Philipp
authors.initials: P
authors.lastname: Schroth
authors.affiliation: Institute for Photon Science and Synchrotron Radiation, Karlsruhe Institute of Technology, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany.
authors.forename: Martin
authors.initials: M
authors.lastname: Köhl
authors.affiliation: Institute for Photon Science and Synchrotron Radiation, Karlsruhe Institute of Technology, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany.
authors.forename: Jean-Wolfgang
authors.initials: JW
authors.lastname: Hornung
authors.affiliation: Paul-Drude-Institut für Festkörperelektronik, Hausvogteiplatz 5-7, 10117 Berlin, Germany and Helmholtz-Zentrum Dresden-Rossendorf, Bautzner Landstraße 400, 01328 Dresden, Germany.
authors.forename: Emmanouil
authors.initials: E
authors.lastname: Dimakis
authors.affiliation: Paul-Drude-Institut für Festkörperelektronik, Hausvogteiplatz 5-7, 10117 Berlin, Germany.
authors.forename: Claudio
authors.initials: C
authors.lastname: Somaschini
authors.affiliation: Paul-Drude-Institut für Festkörperelektronik, Hausvogteiplatz 5-7, 10117 Berlin, Germany.
authors.forename: Lutz
authors.initials: L
authors.lastname: Geelhaar
authors.affiliation: University of Siegen, Solid State Physics, 57068 Siegen, Germany.
authors.forename: Andreas
authors.initials: A
authors.lastname: Biermanns
authors.affiliation: ANKA, Karlsruhe Institute of Technology, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany.
authors.forename: Sondes
authors.initials: S
authors.lastname: Bauer
authors.affiliation: ANKA, Karlsruhe Institute of Technology, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany and Institute for Photon Science and Synchrotron Radiation, Karlsruhe Institute of Technology, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany.
authors.forename: Sergey
authors.initials: S
authors.lastname: Lazarev
authors.affiliation: University of Siegen, Solid State Physics, 57068 Siegen, Germany.
authors.forename: Ullrich
authors.initials: U
authors.lastname: Pietsch
authors.affiliation: ANKA, Karlsruhe Institute of Technology, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany; Institute for Photon Science and Synchrotron Radiation, Karlsruhe Institute of Technology, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany; and Laboratory for Application of Synchrotron Radiation, Karlsruhe Institute of Technology, Kaiserstraße 12, 76131 Karlsruhe, Germany.
authors.forename: Tilo
authors.initials: T
authors.lastname: Baumbach