Production of quantum dots by selective interdiffusion in CdTe/CdMgTe quantum wells
- Universitaet Wuerzburg, Technische Physik (Germany)
- Universitaet Duisburg-Essen, Lehrstuhl Wekstoffe der Elektrotechnik (Germany)
Individual quantum dots are produced by selective interdiffusion between the barriers and the quantum well layer in a CdTe/CdMgTe heterostructure. The heterostructure, with a SiO{sub 2} mask preliminarily deposited onto the surface, was subjected to short-term annealing for 1 min at the temperature 410 deg. C. The mask contained open apertures with diameter up to 140 nm. The annealing induces diffusion of Mg atoms into the depth of the quantum well. Diffusion is substantially enhanced under the mask. The induced lateral potential, with minimums in the regions of apertures of the mask, stimulates efficient localization of charge carriers that form quasi-zero-dimensional excitons. The study of radiative recombination suggests complete spatial confinement of the excitons. The confinement manifests itself in the observation of a substantially narrowed line of excitonic transitions, as well as in the observation of biexcitons and excited states at high levels of photoexcitation. The characteristic energies of interlevel splitting and the biexciton binding energy show that charge carriers are under the condition of weak confinement in the quantum dots.
- OSTI ID:
- 21087962
- Journal Information:
- Semiconductors, Vol. 41, Issue 11; Other Information: DOI: 10.1134/S1063782607110127; Copyright (c) 2007 Nauka/Interperiodica; Article Copyright (c) 2007 Pleiades Publishing, Ltd; Country of input: International Atomic Energy Agency (IAEA); ISSN 1063-7826
- Country of Publication:
- United States
- Language:
- English
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