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TT: Fachverband Tiefe Temperaturen

TT 65: Quantum Dots: Optical Properties II (organized by HL)

TT 65.3: Talk

Wednesday, April 2, 2014, 12:00–12:15, POT 251

Stark shifts in single and vertically stacked GaAs QDs — •Arne Ungeheuer, Achim Küster, Andreas Graf, David Sonnenberg, Christian Heyn, and Wolfgang Hansen — Institut für Angewandte Physik, Universität Hamburg, 20355 Hamburg, Germany

We study the optical properties of single GaAs quantum dots (QDs) and quantum dot molecules (QDMs) in vertical electrical fields. The QDs and QDMs are fabricated using molecular beam epitaxy in combination with the local droplet etching (LDE) technique [1]. Using Al-droplets on AlGaAs substrates, nanoholes of some ten nanometers depth are drilled and subsequently filled with GaAs to form QDs or with a GaAs/AlGaAs/GaAs sequence to form QDMs. Here, we report on the electric field-dependent energy-shift of the excitonic states due to the quantum-confined Stark-effect. Using a Schottky-diode structure and a micro-photoluminescence setup we observe a red-shift up to 25 meV.
[ 1 ] D. Sonnenberg et al., Appl. Phys. Let. 101, 183113 (2012)