Regensburg 2016 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe
HL: Fachverband Halbleiterphysik
HL 60: III-V Semiconductors (no Nitrides)
HL 60.9: Vortrag
Mittwoch, 9. März 2016, 17:15–17:30, H13
Thermal annealing of GaAs nanowires studied by in-situ time-resolved x-ray diffraction — •Seyed M M Kashani1, Philipp Schroth1,2,3, Julian Jakob2, Jonas Vogel1, Martin Köhl3, Tilo Baumbach2,3,4, and Ullrich Pietsch1 — 1University of Siegen, Solid State Physics, Siegen, Germany — 2Laboratory for Application of Synchrotron Radiation (LAS), Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany — 3Institute for Photon Science and Synchrotron Radiation (IPS), Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany — 4Synchrotron Facility ANKA, Karlsruhe Institute of Technology, Karlsruhe, Germany
In this contribution, we present a first attempt in studying the evolution of sublimation kinetics and polytypism during after-growth annealing of GaAs nanowires by in-situ X-ray diffraction and using a portable MBE chamber. The experiment has been performed at the beamline P09 of PETRA III (DESY) synchrotron using a wavelength of ~0.83 Å. Prior to annealing GaAs NWs were grown by self-catalyzed MBE onto Si(111). In a second step, the characteristic Bragg reflections of zinc-blende (ZB) (220) and (311), and wurtzite (WZ) (10.3) were simultaneously and repeatedly monitored during annealing at nine different temperatures ranging from 270°C to 670°C in steps of 50°C. The decomposition rate of ZB and WZ portions and NW diameters were determined from the evolution of integrated intensity and reflection shape, respectively. Whereas the intensity of WZ reflection decreases continuously, there is a discontinuity of ZB intensity at about 445+-25°C.