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KR: Fachverband Kristallographie
KR 2: Crystallography in nanoscience
KR 2.5: Vortrag
Dienstag, 23. März 2010, 11:00–11:15, H9
The X-ray investigation of GaAs nanorods grown onto Si[111] substrate — •Antron Davydok1, Andreas Biermanns1, Ullrich Pietsch1, Steffen Breuer2, and Lutz Geelhaar2 — 1University of Siegen, Siege, Germany — 2Paul-Drude-Institut für Festkörperelektronik, Berlin, Germany
Nanorods (NR) are of particular interest due to the ability to synthesize single-crystalline 1D epitaxial structures and heterostructures in the nanometer range. It was found that nearly any AIIIBV semiconductor material can be grown as NRs onto another AIIIBV or group IV [111] substrate independent from lattice mismatch. We presented an X-ray characterization of GaAs NRs on Si [111] grown by gold-seed assist MBE method. We concentrated our research on 4 samples with different growth time: a) at 5s growth time several island but no NWs are found on the surface; b) at 60s first NWs appeared; c) at 150s the size of rods is increased; d) at 1800s many NWs occupy the whole surface. Using synchrotron radiation we have performed experiments in symmetrical and asymmetrical out-of plane scattering geometry and depth resolved grazing-incidence diffraction. Combining the results we were able to determine the strain gradient between wurzite like NR and zincblende substrate. Using particularly asymmetric wurzite-like reflections under coherent beam illumination we could quantify the number of stacking faults In the talk we present details of the analysis and first simulation results.