Regensburg 2016 – wissenschaftliches Programm
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HL: Fachverband Halbleiterphysik
HL 60: III-V Semiconductors (no Nitrides)
HL 60.6: Vortrag
Mittwoch, 9. März 2016, 16:30–16:45, H13
CXDI as tool for real structure analysis — •Arman Davtyan1, Alexander Seel1, Otmar Loffeld1, Sebastian Lehmann2, Dominik Kriegner3, Mohammad Kashani1, Ali Al Hassan1, and Ullrich Pietsch1 — 1NT faculty, University of Siegen, Siegen, Germany — 2Department of Physics and The Nanometer Structure Consortium, Lund University, P.O. Box 118, 22 100 Lund, Sweden — 3Department of Condensed Matter Physics, Charles University in Prague, Ke Karlovu 5, 121 16 Prague 2, Czech Republic
The distribution of planar stacking faults and twins within single semiconductor GaAs nanowires (NWs) has been studied using the Coherent x-ray diffraction imaging (CXDI) technique at ID1 beamline at ESRF. CXDI probes the defect structure of the certain segment along the nanowire growth direction at asymmetric geometry with grazing exit condition. CXDI pattern from the segment of the NW shows a clear periodicity around the (10-15) WZ reflection indicating that the segment of the NW which is being illuminated with coherent X-rays has only few stacking faults. The electron density distribution in real space can be inverted from the diffraction pattern. We demonstrate the feasibility of phase retrieval algorithms in case of low density planar defects along the NW growth direction following the approach demonstrated for the NWs with high density of stacking faults. Here, we present also a novel approach to retrieve the arrangement of twin domains within single GaAs nanowires based on Kalman filter and L1 minimization.