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arXiv · 1308.1799

Coupling of exciton states as the origin of their biexponential decay dynamics in GaN nanowires

Christian Hauswald·Timur Flissikowski·Tobias Gotschke·Raffaella Calarco·Lutz Geelhaar·Holger T. Grahn·Oliver Brandt
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Abstract

Using time-resolved photoluminescence spectroscopy, we explore the transient behavior of bound and free excitons in GaN nanowire ensembles. We investigate samples with distinct diameter distributions and show that the pronounced biexponential decay of the donor-bound exciton observed in each case is not caused by the nanowire surface. At long times, the individual exciton transitions decay with a common lifetime, which suggests a strong coupling between the corresponding exciton states. A system of non-linear rate-equations taking into account this coupling directly reproduces the experimentally observed biexponential decay.

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Christian Hauswald, Timur Flissikowski, Tobias Gotschke, Raffaella Calarco, Lutz Geelhaar, Holger T. Grahn, Oliver Brandt. 2013-08-08. Coupling of exciton states as the origin of their biexponential decay dynamics in GaN nanowires. https://doi.org/10.1103/physrevb.88.075312

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