Berlin 2008 – wissenschaftliches Programm

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HL: Fachverband Halbleiterphysik

HL 49: ZnO: Optical properties

HL 49.4: Vortrag

Donnerstag, 28. Februar 2008, 11:30–11:45, ER 164

Random lasing in ZnO nanopowders — •Roman J.B. Dietz, Johannes Fallert, Felix Stelzl, Huijuan Zhou, Janos Sartor, Claus Klingshirn, and Heinz Kalt — Institut für Angewandte Physik, Universität Karlsruhe (TH), Germany

We investigate the optical properties and random lasing effects of nanocrystalline ZnO powders under high optical excitation. The powders are excited by a pulsed Nd:YAG laser at 355 nm with a pulse duration of 5 ns. The different powders have different average particle sizes which vary from 50 nm to several µ m. This gives us the opportunity to measure the threshold of lasing in dependence, among others, on particle size. Furthermore by investigating single pulse spectra we are also able to make statistical evaluations of the lasing probability. We also evaluate the dependence on temperature and size of excited area.