Berlin 2008 – wissenschaftliches Programm

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HL: Fachverband Halbleiterphysik

HL 17: Poster I

HL 17.17: Poster

Montag, 25. Februar 2008, 16:30–19:00, Poster D

Epitaxially grown ZnO heterostructures for nanophotonic devices — •Marcel Ruth and Cedrik Meier — Department of Physics, Group NanoPhox, University of Duisburg-Essen, Lotharstr. 1, 47057 Duisburg

Due to its unique properties such as the large direct bandgap of 3.37eV and its high exciton binding energy, zinc oxide (ZnO) is a highly promising semiconductor for optoelectronic devices even at room temperature. By adding cadmium (Cd) or magnesium (Mg) the bandgap can be tuned between 3.0eV and 4.0eV. Above that, it is simpler to form laterally patterned devices and structures based on ZnO than on gallium nitride (GaN), e.g., by chemical etching.
For the fabrication of high-quality ZnO-based heterostructures as required for nanophotonic applications, plasma-assisted molecular beam epitaxy (MBE) is a very suitable technique. Our samples are grown in a vertical MBE system (Riber Compact 12) with double zone effusion cells and a RF-plasma source for atomic oxygen.
We present the first results of the epitaxially grown ZnO, (Zn,Mg)O and (Zn,Cd)O layers on c-plane sapphire and ZnO. The samples are characterized by morphological methods in-situ by reflection high energy diffraction (RHEED) and ex-situ methods such as atomic force microscopy (AFM), scanning electron microscopy (SEM) and x-ray diffraction (XRD). Furthermore, photoluminescence (PL) spectroscopy is used to determine their usability for nanophotonic devices like photonic crystals and microdisks.