Regensburg 2010 – wissenschaftliches Programm

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HL: Fachverband Halbleiterphysik

HL 21: Quantum Dots and Wires, Optical Properties I: Nitrides

HL 21.7: Vortrag

Dienstag, 23. März 2010, 11:00–11:15, H17

Optical properties of GaN/AlGaN heterostructures embedded in GaN nanowires — Florian Furtmayr², •Jörg Teubert¹, Pascal Becker¹, Martin Stutzmann², and Martin Eickhoff¹ — ¹I. Physikalisches Institut, Justus-Liebig-Universität, 34392 Gießen, Germany — ²Walter Schottky Institut, Technische Universität München, 85748 Garching, Germany

A fascinating property of self-assembled III-N nanowires grown by molecular beam epitaxy (MBE) is their high crystal quality as it provides the possibility to perform fundamental studies of the material properties without the perturbing influence of structural defects. In this context, heterostructures such as quantum wells embedded in nanowires are of special interest. We report on structural and optical properties of GaN/Al_xGa_1−xN nanowires with embedded GaN nanodisks grown by plasma assisted MBE on Si(111) substrates. Lateral overgrowth with the AlGaN barrier material during the synthesis of multi quantum-disk structures leads to the formation of a core-shell system that influences the mechanical strain in the quantum well regions. The effect on the optical properties of multi quantum-disk structures was investigated by temperature dependent photoluminescence measurements on samples with different structural parameters. The results will be discussed in terms of carrier confinement, strain and piezoelectric effects and will be compared to theoretical simulations.