Talk by Ullrich Pietsch, University of Siegen – Niels Bohr Institute - University of Copenhagen

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Talk by Ullrich Pietsch, University of Siegen

Semiconductor nanowires (NW) are of particular interest due to the ability to synthesize single-crystalline 1D epitaxial structures and heterostructures in the nanometer range.
The superior electrical and optoelectronic properties of semiconductor nanowires make them very desirable as building blocks in future nanoscale devices. Typically, transmission electron microscopy can be used to inspect individual NWs. However, this approach is destructive and allows the inspection of a very limited number of nanowires only. Complementary, recent developments in x-ray optics allow to perform diffraction studies on individual nano-objects.

In this contribution we present the methodic of X-ray single nanowire inspection using the micro-focus setup available at the ID1 beamline of ESRF. As examples
of application we show strain analysis at individual GaAs NW grown on patterned GaAs[111] substrate [1], Au- seed assisted GaAs NW grown on Si[111] and catalyst free GaAs NWs growth on Si[111] demonstrating that the NWs may differ in shape, morphology and strain among each other. Particular effort was spent to investigate the early stage of NW growth and to understand more about how the huge lattice mismatch between NW and substrate is released.

Talk by: Ullrich Pietsch - University of Siegen, Festkörperphysik, Siegen, Germany