Dresden 2011 – wissenschaftliches Programm

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KR: Fachgruppe Kristallographie

KR 7: Crystallography in Materials Science (jointly with DF)

KR 7.1: Hauptvortrag

Donnerstag, 17. März 2011, 14:00–14:45, HSZ 101

Crystallography of Nanowires — •Julian Stangl¹, Dominik Kriegner¹, Christian Panse², Bernhard Mandl^1,3, Kimberley A Dick³, Mario Keplinger¹, Johan M Persson⁴, Philippe Caroff^3,5, Daniele Ercolani⁶, Lucia Sorba⁶, Friedhelm Bechstedt², and Günther Bauer¹ — ¹Johannes Kepler University Linz, Austria — ²Friedrich-Schiller-Universität Jena, Germany — ³Lund University, Sweden — ⁴Technical University of Denmark — ⁵IEMN, UMR CNRS, France — ⁶Scuola Normale Superiore Pisa, Italy

Semiconductor nanowires are interesting not only from physical and technological viewpoints, but also in a crystallographic sense. While most III-V semiconductors, except nitrides, crystallize exclusively in the cubic zinc-blende lattice in bulk or epitaxial layers, in nanowires very often hexagonal modifications such as wurtzite, but also the more complex 4H structure are observed. The wires grow mainly along the cubic <111> directions, where those lattice structures on first sight differ only by the stacking sequence of bilayers, changing from fcc to hcp. Detailed x-ray diffraction investigations for InAs and InSb nanowires reveal, however, that beside the stacking sequence also the atomic distances change, so that the unit cells deform compared what would be expected from a simple change of stacking. Comparisons to density functional theory calculations are in excellent agreement with the experimental data, and the combination of x-ray diffraction and theoretical calculations allow explaining the reason for the observed changes in atomic distances.