Regensburg 2013 – wissenschaftliches Programm
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HL: Fachverband Halbleiterphysik
HL 69: Poster Session: II-VI semiconductors; Organic semiconductors; Heterostructures
HL 69.7: Poster
Mittwoch, 13. März 2013, 16:00–20:00, Poster A
Analysis of the energy transfer process in ZnS:Mn and ZnS:Tb by a modified Förster model — •Sebastian Gies1, Uwe Kaiser1, Wolfram Heimbrodt1, Sebastian Geburt2, and Carsten Ronning2 — 1Dept. of Physics, Philipps-University Marburg, Germany — 2Institute of Solid State Physics, Friedrich-Schiller University Jena, Germany
Zinc Sulphide nanowires doped with different luminescence centers, i.e. Manganese and Terbium, are characterized by means of time-resolved photoluminescence spectroscopy, in order to analyze the energy transfer process quantitatively. To achieve this, a modified Förster model is utilized, describing the energy transfer with respect to migration, quenching processes and dimensionality of the energy transfer.
To test the resilience and validity of the modified Förster model nanowires with doping concentrations from 4·10−3% to 4% were manufactured. The luminescence of the internal 4f8- (Tb3+) and 3d5-transitions (Mn2+) was measured over four orders of magnitude. Furthermore, the measurements were performed at varying excitation densities and temperatures, leading to a deeper understanding of the energy transfer process and its description via the modified Förster model. We were able to determine the hitherto unknown Förster radius of Tb3+ ions. Moreover, using µ-photoluminescence we have performed measurements on single nanowires and compared the results with measurements on macroscopic numbers of wires. We found, that the decay characteristics of single wires resemble the ensemble measurements. The statistical reason will be discussed in detail.