Berlin 2008 – wissenschaftliches Programm
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HL: Fachverband Halbleiterphysik
HL 53: Optical properties
HL 53.2: Vortrag
Freitag, 29. Februar 2008, 10:45–11:00, EW 201
Energy transfer and excitation dynamics in doped 1D- and 2D-nanostructures — •Tobias Niebling1, Manuel Demper1, Limei Chen1, Wolfram Heimbrodt1, Peter J. Klar2, Daniel Stichtenoth3, and Carsten Ronning3 — 1Department of Physics and Material Sciences Center, Philipps University Marburg, Germany — 2Institute of Experimental Physics I, Justus-Liebig University Gießen, Germany — 3II. Institute of Physics, University of Göttingen, Germany
Migration of optical excitation trapped in localized states is a general feature of doped semiconductors. However, the basic physical processes are not yet entirely clarified. Therefore ZnS and ZnO wires and ribbon-like crystals with diameters varying between 100 nm and 1 µm are synthesized in a vapour-liquid-solid process (VLS). Different doping elements are incorporated by ion beam implantation with variing fluencies. The energy transfer and migration processes inside the subsystem of the doping as well as the subsequent transfer to defect or radiationless centres are investigated by time-resolved photoluminescence spectroscopy in the range of 1 ns to 1 ms after the excitation pulse. ZnS and ZnO doped with manganese, rare earth elements and variing ‘killer’ centre concentrations induced by noble gas ion bombardment are studied. To explain the results, the well established Förster-model for energy transfer processes is modified for reduced dimensionality. It can be shown that the dimensionality of the nanostructures is defined by the ratio of the mean distance between the dopings and the ‘killer’ centres as well as the morphology of the nanowires.