Regensburg 2013 – scientific programme
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HL: Fachverband Halbleiterphysik
HL 68: Poster Session: GaN: devices & preparation & characterization; III-V semiconductors; Photonic crystals; Semiconductor lasers
HL 68.20: Poster
Wednesday, March 13, 2013, 16:00–20:00, Poster A
Non-exponential photoluminescence transients in GaNAsP lattice matched to (001) silicon substrate — •Nils C. Gerhardt1, Nektarios Koukourakis1, Markus Finkeldey1, Martin R. Hofmann1, Martin Zimprich2, Kerstin Volz2, Wolfgang Stolz2, Kakhaber Jandieri2, Florian Gebhard2, Sergei Baranovskii2, and Bernardette Kunert3 — 1Photonics and Terahertztechnology, Ruhr-Universität Bochum, Germany — 2Material Science Center and Faculty of Physics, Philipps-University Marburg, Germany — 3NAsP III/V GmbH, Marburg, Germany
The novel dilute nitride material GaNAsP which can be grown lattice-matched on silicon substrate is a very promising material for future integrated, electrically pumped lasers on silicon. Here we present an experimental and theoretical study of the time-resolved photoluminescence (PL) of GaNAsP/BGa(As)P heterostructures grown on (001) silicon substrate. The results show a s-shape behaviour for the temperature dependent PL peak energy and a strong non-exponential behaviour for the PL transients, indicating a significant impact of disorder-induced localization effects. A detailed comparison with theoretical calculations based on Monte-Carlo simulations reveals that the non-exponential PL transient is due to a combination between the fast capture of carriers in non-radiative centers and the slow radiative recombination via localized states. The impact of the localization effects depends strongly on the material composition and growth conditions. Remarkably, the experimental results indicate an unexpected decrease of localization and disorder effects with increasing N content.