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HL: Halbleiterphysik

HL 12: Poster I: Quanten Hall Effekt (1-9), II-VI Halbleiter (10-17), Epitaxie (18-23), Quantenpunkte und -dr
ähte (24-50), Photonik (51-59), Metall-Isolator Übergang (60-64), Si/Ge (65-67), Elektronentheorie (68-69), Amorphe Halbleiter, Ionen-Implantation

HL 12.33: Poster

Montag, 27. März 2000, 14:00–19:00, A

Synthesis and characterization of Mn doped CdS nanocrystals — •H. Zhou, H. Alves, F. Henecker, D. M. Hofmann, and B. K. Meyer — I. Physikalisches Institut der Justus-Liebig-Universität Gießen, Heinrich-Buff-Ring 16, 35392 Gießen

Compared to Mn doped bulk crystals Mn doped nanocrystals show an enhanced efficiency of the internal Mn²⁺ emission and enhanced semi-magnetic effects. These effects are attributed to the confinement of the excitonic wavefunction which increases the interaction with the impurity. We have prepared dopedand undoped CdS nanocrystals in the inverted micelle system water-AOT-heptane. It was found that changing the water-AOT ratio allows to change systematically the nanocrystal diameter. In this way the fundamental absorption edge can be shifted from 2.5 eV (bulk value, > 15 nm) to 3.4 eV, it corresponds to a nanocrystal diameter of 2.8 nm. The optical and magnetic properties of the doped nanocrystals have been studied by photoluminescence and magnetic resonance spectroscopy.