Dresden 2020 – wissenschaftliches Programm

Die DPG-Frühjahrstagung in Dresden musste abgesagt werden! Lesen Sie mehr ...

Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe

HL: Fachverband Halbleiterphysik

HL 49: Quantum dots and wires II

HL 49.3: Vortrag

Mittwoch, 18. März 2020, 15:30–15:45, POT 151

Self-organized linear alignment of high-density Stranski-Krastanov quantum dots — •Tommy Müller, Udo W. Pohl, Laura Meißner, and Tore Niermann — Technische Universität Berlin, Germany

The linear alignment of high-density quantum dot (QD) ensembles is interesting for active waveguide structures. We present the fabrication of a self-organized linear array of such an ensemble in a multilayer structure without the application of post-growth lithography.

We applied the buried-stressor principle [F. Kießling et al., PRB 91, 075306 (2015)]: by selectively oxidizing buried AlGaAs-AlAs-AlGaAs layers, we produce a stripe-shaped tensile strain field in the GaAs cap layer. Here InGaAs Stranski-Krastanov QDs prefer to nucleate on top in a second epitaxy. Nucleation control of linear stressors proved more challenging than on circular stressors due to the reduction to a single lateral strain component. We still achieved a high density of QD stripes with high contrast to the side areas. Further increased QD density decreases the contrast. An improved contrast was obtained for stacked stripe structures, where a second QD layer was nucleated on top of a site-controlled buried first QD layer. The presentation outlines essential parameters for the lateral site control of the QD ensemble, confirmed by strain simulations.