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HL: Fachverband Halbleiterphysik

HL 40: ZnO: preparation and characterization III

HL 40.3: Vortrag

Donnerstag, 26. März 2009, 10:00–10:15, BEY 118

Investigation of ZnO electronic properties by optical deep level transient spectroscopy — •Martin Ellguth, Matthias Schmidt, Rainer Pickenhain, and Marius Grundmann — Universität Leipzig, Institut für Experimentelle Physik II, 04103 Leipzig, Germany

Since ZnO is a promising material for future transparent electronic and opto - electronic devices, a classification of defects according to their optical absorption is necessary. We investigated electronic properties of impurities typically present in ZnO with special regard to the photo cross - section as a fundamental property of a defect. The prominent defects E1, E3, E4 and a presently not reported trap E200 with binding energy of approx. 200 meV were detected by deep level transient spectroscopy (DLTS) measurements. Optical DLTS measurements (ODLTS) were conducted and a measurable signal was achieved for E4 and E200. The photo cross - section of these traps was then calculated from the wavelength dependent optical emission rate obtained from the ODLTS signal. Furthermore, the presence of defect states far from the conduction band edge and therefore undetectable by any thermal capacitance spectroscopic methods has been inferred from the detection of the optically excited emission which some of these defects exhibit.