Dresden 2006 – wissenschaftliches Programm

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HL: Halbleiterphysik

HL 9: Poster I

HL 9.41: Poster

Montag, 27. März 2006, 15:15–17:45, P3

Electrical characterization of ZnO grown by MOCVD on a multi-layer template — •Stephan Tiefenau, H. Witte, A. Krtschil, A. Dadgar, S. Giemsch, and A. Krost — Otto-von-Guericke Universität Magdeburg, FNW/IEP/AHE, Postfach 4120, 39016 Magdeburg

Currently, ZnO layers are in the focus of interest due to its possible applications in future optoelectronic devices, for instance in highly efficient LED and laser diodes. However, there are still some problems in the growth of high quality ZnO and especially in an effective p-type doping. For the latter topic, electrical measurements are important to understand transport and compensation mechanisms and properties of deep defects. The ZnO layers were grown by metal organic vapor phase epitaxy on a GaN/AlN template either on silicon or sapphire substrates. The heterostructures cause space charge regions which influence the electrical characteristics and have to be considered. We compare Hall effect and C-V measurements and show the different information depths of these methods. Furthermore, the impact of layer defects such as holes and surface roughness is investigated systematically with C-V measurements and scanning surface potential microscopy. On the basic of these investigations, properties of ZnO related deep defects and of interface states are characterized using photoconductivity spectroscopy, thermal and optical admittance spectroscopy and deep level transient spectroscopy.