Berlin 2012 – wissenschaftliches Programm
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HL: Fachverband Halbleiterphysik
HL 29: III-V Semiconductors I (mainly Nitrides)
HL 29.2: Vortrag
Dienstag, 27. März 2012, 09:45–10:00, EW 201
Influence of electron beam annealing on the structural and optical properties of GaN:Mg — •Christian Nenstiel1,3, Marc Hoffmann2,3, Trevor Manning3, Gordon Callsen1, Ramon Collazo2, James Twiedie2, Zlatko Sitar2, Matthew Phillips3, and Axel Hoffmann1 — 1Technische Universität Berlin, Institut für Festkörperphysik, Germany — 2North Carolina State University, Materials Science and Engineering, USA — 3University of Technology Sydney, Department of Physics and Advanced Materials, Australia
The chemical and structural origin of the in Magnesium doped GaN observed donor acceptor pair transitions (DAP) is not yet fully understood. Furthermore, the dynamics of Hydrogen during the commonly applied thermal activation process of MOCVD grown GaN:Mg are still a matter of active debate. To investigate these questions we grew 700 nm thick GaN:Mg layers. The samples exhibit Magnesium concentrations from 5E17 to 2E19 cm-3 and thermal annealing was before between 450 and 650 °C. Under electron beam exposure in CL measurements at 10 K we observed an increase of the intensity of the DAP luminescence until saturation after a few seconds which is then followed by rather complex shifting and quenching dynamics of the DAP luminescence. Additionally, we observed the quenching of acceptor bound excitons over time. None of these effects can be observed by Photoluminescence measurements , not even in the high excitation regime which allows us to derive electron beam induced technologically relevant dynamics of Hydrongen in GaN:Mg.