Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe

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 Al_0.64Ga_0.36N/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 Al_xGa_1−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.