Regensburg 2016 – wissenschaftliches Programm

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HL: Fachverband Halbleiterphysik

HL 35: Poster I

HL 35.43: Poster

Dienstag, 8. März 2016, 15:00–19:00, Poster A

Influences of molecular flux gradients on the optical characteristics of GaAs/AlGaAs quantum wells — •Pia Eickelmann, Rüdiger Schott, Andreas D. Wieck, and Arne Ludwig — Lehrstuhl für Angewandte Festkörperphysik, Ruhr-Universität Bochum, Universitätsstr. 150, D-44780 Bochum, Germany

Semiconductor heterostructures with quantum wells (QW) find application e.g. in high electron mobility transistors, diode lasers or quantum cascade lasers. A good control of the well thicknesses and alloy compositions during the molecular beam epitaxy (MBE) growth is vital, as these mainly determine the quantization energies.

In this contribution, we present the effect of a spatial molecular flux gradient on an MBE grown GaAs/AlGaAs QW structure. Mounting the substrate in the MBE chamber nonaxially with respect to the Ga and Al effusion cell and stopping the rotation of the wafer cause this present flux gradient. We simulate the QW transition energies due to the change in Al concentration in the barrier and the width of the QW. The trend observed by photoluminescence measurements on the flux gradient grown QW wafer is well reproduced. Furthermore we investigate monolayer steps for the QWs in the same sample.