04/25/2011 Colloquium - Christian Teichert
Title: Origins, Visions, Plans & Wave Reactors
Date: Apr 25, 2011
Location: 3105 Etcheverry Hall
Low-energy ion irradiation of semiconductor surfaces  opens an elegant and efficient route towards fabrication of large-scale arrays of uniform semiconductor nanostructures. Using power spectral density analysis of atomic force microscopy (AFM) images, the degree of pattern uniformity can be quantified as is demonstrated for ion- bombardment induced GaSb dot arrays . Attempts to obtain similar pattern formation by ion-bombardment of clean silicon substrates fail , unless there is a supply of metal impurities .
Since the ion-bombardment induced nanostructure arrays cover the entire sample surface, they can be used as large-area nanopatterned templates for subsequent deposition of magnetic thin films. This will be illustrated for the shadow deposition of cobalt onto ion-bombardment induced GaSb dot patterns. It will further be demonstrated how pre-ion bombardment can influence the resulting growth mode of organic semiconductor films . Finally, it is shown that friction force microscopy and atomic-force microscopy can be employed to study single impacts of highly charged ions.
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This research has been supported in the framework of the European Project NAMASOS (Nanomagnets by Self-Organisation, Grant No. STRP 505854-1) and by Austrian Science Fund within NFN “Organic Thin Films” project S9707.