Regensburg 2016 – wissenschaftliches Programm

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HL: Fachverband Halbleiterphysik

HL 59: Optical Properties II

HL 59.3: Vortrag

Mittwoch, 9. März 2016, 15:15–15:30, H10

Investigation of the binding energy of Al_xGa_1−xAs/Al_yGa_1−yAs quantum wells for high temperature polariton lasers — •Stefanie Kreutzer¹, Holger Suchomel¹, Sebastian Brodbeck¹, Maciej Pieczarka², Grzegorz Sȩk², Christian Schneider¹, and Sven Höfling^1,3 — ¹Technische Physik, Physikalisches Institut and Wilhelm Conrad Röntgen-Research Center for Complex Material Systems, Universität Würzburg, Am Hubland, 97074 Würzburg — ²Institute of Physics, Wroclaw University of Technology, Wybrzeze Wyspianskiego 27, 50-370 Wroclaw, Poland — ³SUPA, School of Physics and Astronomy, University of St. Andrews, St. Andrews KY16 9SS, United Kingdom

We study the exciton binding energy in Al_xGa_1−xAs/Al_yGa_1−yAs quantum wells for various aluminium concentrations in well and barrier as well as well widths. Binding energies are determined by comparing calculated transition energies to experimental values obtained from photoluminescence and photoreflectance studies. We find a strong enhancement of the binding energy compared to GaAs/Al_xGa_1−xAs quantum wells with increasing transition energy until the type I-type II-transition crossover with values exceeding 25 meV.

When integrating these quantum wells into microcavities, we observe a normal mode splitting between excitons and photons. Strong coupling persists at elevated temperatures with a measured Rabi splitting of 5meV at 230K.