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

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.

5 pages, 4 figures

Cited by in corpus (7)

• Stacking faults as quantum wells in nanowires: Density of states, oscillator strength and radiative efficiency
• Investigating the origin of the nonradiative decay of bound excitons in GaN nanowires
• Sub-meV linewidth in GaN nanowire ensembles: absence of surface excitons due to the field-ionization of donors
• Long-lived excitons in GaN/AlN nanowire heterostructures
• Nature of excitons bound to inversion domain boundaries: Origin of the 3.45-eV luminescence lines in spontaneously formed GaN nanowires on Si(111)
• Crystal-phase quantum dots in GaN quantum wires
• Time-resolved dynamics of GaN waveguide polaritons