Regensburg 2016 – wissenschaftliches Programm
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HL: Fachverband Halbleiterphysik
HL 62: Gallium Nitride: Optical and Electronic Properties
HL 62.5: Vortrag
Mittwoch, 9. März 2016, 15:45–16:00, H17
Photoluminescence excitation measurements of molecular beam epitaxial grown cubic GaN/Al(Ga)N quantum well structures — •Tobias Wecker1, Gordon Callsen2, Axel Hoffmann2, Dirk Reuter1, and Donat J. As1 — 1Department of Physics, University of Paderborn, Warburger Straße 100, 33098 Paderborn, Germany — 2Institut für Festkörperphysik, TU Berlin, Straße des 17. Juni 135, 10623 Berlin, Germany
In recent years group III-nitrides and their compounds have been in the focus of interest for devices based on intersubband transitions in the 1.55 µ m spectral region. For such devices the understanding of the complete energy level structure is crucial to manipulate the allowed transitions. Photoluminescence excitation (PLE) spectroscopy gives access to the excited energy levels. In hexagonal group III nitrides the adjustment of the quantum well (QW) energy levels is complicated by the quantum confined stark effect, resulting from spontaneous polarization fields. Due to the higher crystal symmetry this harmful effect is absent in the cubic phase along the (001) direction. We investigate an uncoupled asymmetric cubic GaN/Al0.25Ga0.75N double quantum well and a single cubic GaN/AlN QW grown on 3C-SiC (001) substrate by radio-frequency plasma-assisted molecular beam epitaxy. PLE and photoluminescence spectra, taken at 7 K, show several emission bands. Comparing these emission bands with simulated transitions calculated by a Schrödinger-Poisson solver based on an effective mass model (nextnano3) revealed a good agreement between theory and experiment.