Dresden 2006 – scientific programme

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HL: Halbleiterphysik

HL 36: Optical properties

HL 36.4: Talk

Wednesday, March 29, 2006, 17:00–17:15, POT 151

1.55 µm luminescence from InAs/In_xGa_1−xAs_1−yN_y quantum dots grown on GaAs substrates — •Mirja Richter^1,2, Benjamin Damilano¹, Jean Massies¹, Jean-Yves Duboz¹, Dirk Reuter², and Andreas D. Wieck² — ¹Centre de Recherche sur l’Hétéro-Epitaxie et ses Applications, CNRS, Sophia-Antipolis, F-06560 Valbonne, France — ²Lehrstuhl für Angewandte Festkörperphysik, Ruhr-Universität Bochum, D-44780 Bochum, Germany

Self-assembled InAs quantum dots (QDs) encapsulated with an In_xGa_1−xAs_1−yN_y (GINA) layer were grown by molecular beam epitaxy on GaAs substrates. The objective is to get efficient 1.55 µm emission from these nanostructures. The interest of adding nitrogen to the classical system InAs/In_xGa_1−xAs is that it decreases the bandgap of In_xGa_1−xAs with an enormous band bowing but also compensates parts of the strain. However, adding nitrogen introduces a high density of point defects which results in degraded photoluminescence (PL) properties. Fortunately, the density of these defects can be decreased by rapid thermal annealing (RTA). The growth process was optimized including a change in growth temperature and rate for the QDs and the GINA layer. RTA was carried out at optimized temperatures. Thereby we achieve high intensity PL emission in the 1.55 µm range with a small full width at half maximum from these InAs/GINA QDs. Finally, studies of the growth on focussed ion beam structured doping regions will be presented.