Berlin 2005 – scientific programme
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HL: Halbleiterphysik
HL 44: II-VI Halbleiter IV
HL 44.11: Talk
Monday, March 7, 2005, 17:30–17:45, TU P-N201
Interdiffusion in single self-assembled ZnCdSe quantum dots — •Emanuela Margapoti1, Lukas Worschech1, Alfred Forchel1, Georg Schmidt2, and Laurens W. Molenkamp2 — 1Technische Physik, Universität Würzburg, Am Hubland, 97074 Würzburg — 2Experimentelle Physik III, Universität Würzburg, Am Hubland, 97074 Würzburg
Spectral properties of single self-assembled ZnCdSe quantum dots embedded in a ZnSe matrix were studied after several successively performed thermal annealing steps. Small mesas with only a small number of quantum dots were fabricated by electron beam lithography and wet etching. Comparable small annealing temperatures ranging between 100 to 240 ∘C each applied for 30s result in blue shifts of single exciton lines up to 100 meV. The observed blue shifts fit well to a model assuming an energy activated interdiffusion process with activation energies as small as 0.5 eV indicating that the diffusion properties are significantly altered compared to higher dimensional structures composed of the same material.