Hinweise und Hilfestellungen zur erfolgreichen Inklusion von Schülerinnen und Schülern mit Hör- oder Sehstörungen an weiterführenden Regelschulen

Diese Arbeit befasst sich mit den Störungsbildern Hörschädigung und Sehschädigung und gibt konkrete Vorschläge, wie die Inklusion von Schülerinnen und Schülern mit diesen Störungsbildern in der Praxis umgesetzt werden kann

Serum enzymes and metabolites related with high production and longevity

International audienc

Nucleation and growth of GaN nanorods on Si (111) surfaces by plasma-assisted molecular beam epitaxy - The influence of Si- and Mg-doping

The self-assembled growth of GaN nanorods on Si (111) substrates by plasma-assisted molecular beam epitaxy under nitrogen-rich conditions is investigated. An amorphous silicon nitride layer is formed in the initial stage of growth that prevents the formation of a GaN wetting layer. The nucleation time was found to be strongly influenced by the substrate temperature and was more than 30 min for the applied growth conditions. The observed tapering and reduced length of silicon-doped nanorods is explained by enhanced nucleation on nonpolar facets and proves Ga-adatom diffusion on nanorod sidewalls as one contribution to the axial growth. The presence of Mg leads to an increased radial growth rate with a simultaneous decrease of the nanorod length and reduces the nucleation time for high Mg concentrations

Atomic scale strain relaxation in axial semiconductor III-V nanowire heterostructures

Combination of mismatched materials in semiconductor nanowire heterostructures offers a freedom of bandstructure engineering that is impossible in standard planar epitaxy. Nevertheless, the presence of strain and structural defects directly control the optoelectronic properties of these nanomaterials. Understanding with atomic accuracy how mismatched heterostructures release or accommodate strain, therefore, is highly desirable. By using atomic resolution high angle annular dark field scanning transmission electron microscopy combined with geometrical phase analyses and computer simulations, we are able to establish the relaxation mechanisms (including both elastic and plastic deformations) to release the mismatch strain in axial nanowire heterostructures. Formation of misfit dislocations, diffusion of atomic species, polarity transfer, and induced structural transformations are studied with atomic resolution at the intermediate ternary interfaces. Two nanowire heterostructure systems with promising applications (InAs/InSb and GaAs/GaSb) have been selected as key examples

Nanodrähte aus Gruppe III-Nitrid-Halbleitern

Scope of this work is the growth and characterization of group III-nitride nanostructures. GaN Nanowires (NWs) and AlGaN/GaN NW heterostructures with thin inclusions (nanodisks) of GaN or InGaN were grown by molecular beam epitaxy (MBE) and analyzed with respect to their morphology by scanning and transmission electron microscopy. Their optical properties were investigated by photoluminescence spectroscopy. The influence of doping with Si and Mg was studied in detail. Additionally, electrical measurements on single NWs are presented.Inhalt dieser Arbeit ist das Wachstum und die Charakterisierung von Nanostrukturen aus Gruppe III-Nitridhalbleitern. GaN Nanodrähte (NWs) und AlGaN/GaN NW-Heterostrukturen mit gezielten Einschlüssen von GaN oder InGaN wurden mittels Molekularstrahlepitaxie (MBE) hergestellt und durch Raster- und Transmissions-Elektronenmikroskopie sowie durch Photolumineszenz-Spektroskopie untersucht. Der Einfluss der Dotierstoffe Si und Mg wurde auf gleiche Weise analysiert. Zusätzlich wurden elektrische Messungen an einzelnen NWs durchgeführt