Dresden 2017 – wissenschaftliches Programm
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HL: Fachverband Halbleiterphysik
HL 59: Nitrides: Preparation and Characterization II
HL 59.4: Vortrag
Mittwoch, 22. März 2017, 15:30–15:45, POT 251
Time-resolved Investigation of Charge Transfer in Asymmetric Cubic Al0.64Ga0.36N/GaN Double Quantum Wells Grown by MBE — •Tobias Wecker1, Gordon Callsen2, Axel Hoffmann2, Dirk Reuter1, and Donat Joseph As1 — 1Department of Physics, University of Paderborn, 33098 Paderborn — 2Institut für Festkörperphysik, Technische Universität Berlin, 10623 Berlin
Non-resonant carrier transfer between quantum wells (QWs) is of high significance for many devices like quantum cascade lasers. In this study, time-resolved photoluminescence is used to investigate this effect in asymmetric double QWs for low temperatures. Asymmetric cubic AlxGa1−xN/GaN double QWs with an Al content of x = 0.64 * 0.03 were grown on 3C-SiC (001) substrate by radio-frequency plasma-assisted molecular beam epitaxy. Three samples with different barrier thickness d were analyzed (1 nm, 3 nm, 15 nm). The two QWs are 2.5 nm and 1.35 nm thick, to show separated emission bands in the luminescence. Three clearly distinguishable emission bands at 3.49 eV, 3.73 eV and 4.12 eV are observed and could be assigned to the different layers. A correlation between the carrier lifetimes in the QWs and the barrier thickness is found. Exploiting rate equations the intensity ratios of both QW emissions have been calculated. Electronic coupling between the QWs is only observed for barrier thicknesses below 3 nm.