Dresden 2009 – wissenschaftliches Programm
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HL: Fachverband Halbleiterphysik
HL 2: GaN: devices
HL 2.7: Vortrag
Montag, 23. März 2009, 12:00–12:15, BEY 118
Phonon-assisted contributions to the Auger losses in InGaN quantum wells — •Bernhard Pasenow1, Stephan W. Koch1, Jörg Hader2, and Jerome V. Moloney2 — 1Department of Physics and Materials Sciences Center, Philipps Universität Marburg, Renthof 5, 35032 Marburg, Germany — 2Nonlinear Control Strategies Inc., 3542 N. Geronimo Ave., Tucson, AZ 85705 and Optical Sciences Center, University of Arizona, Tucson, Arizona 85721
The external quantum efficiency (EQE) of typical GaN-based light emitting diodes
shows a maximum at very low pump currents
and then decreases, often to only half that value for pump currents desired for applications.
The reason for this effect is the loss of a significant fraction of the carriers pumped into the structure.
One possible origin of this EQE-droop – beside some others like carrier leakage – is the carrier recombination through non-radiative Auger processes.
In our talk, we present a microscopic theory which is capable of describing
non-radiative Auger losses in InGaN quantum wells.
Since the calculated direct band-to-band Auger contributions are too small [1] in comparison to measurements,
we focus on the phonon-assisted losses presenting details on our theoretical model, the structure of the Auger loss equations and numerical results.
[1] J. Hader, J.V. Moloney, B. Pasenow, S.W. Koch, M. Sabathil, N. Linder, and S. Lutgen, Appl. Phys. Lett. 92, 261103 (2008)