Physics Department
The
Solid State Seminar
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Characterization of ZnO Single
Dr. Gerhard Brauer
Institut fur
lonenstrahlphysik und Materialforschung
2:00 pm Thursday August 31, 2006, Room 101 SH
Abstract
Positron Annihilation Spectroscopy (PAS), based on radioactive positron
sources, is now a well-established tool for the study of electronic and defect
properties of bulk solids, whereas mono-energetic positron beams are needed to
investigate thin films and surfaces. As an introduction, the application and
basic physics behind PAS methods will be explained briefly.
Zinc oxide (ZnO) is a
potential semiconductor suitable for fabrication of visible and UV light
emitters and detectors as well as high-temperature electronics. However, to
achieve this goal, a full understanding of the role of lattice defects is
needed as they largely control the optical and electrical properties. Here, a
summary of our recent research results to identify lattice defects in ZnO
single crystals will be presented which includes the application of radioactive
positron sources, a mono-energetic positron beam, and also theoretical
calculations.
Finally, an outlook
about future work will be given. This includes the construction of an
accelerator-based and pulsed intense positron beam, and the study of ZnO
nanorods.
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Refreshments will be served in the Physics Library at 1:30pm