Regensburg 2016 – wissenschaftliches Programm
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HL: Fachverband Halbleiterphysik
HL 22: Ultrafast Phenomena I (Joint session of HL and O, organized by HL)
HL 22.5: Vortrag
Dienstag, 8. März 2016, 10:30–10:45, H10
Auger Recombination and Charge Transfer of CdSe/CdS Core/Shell Quantum Dot/Quantum Rods — •Mona Rafipoor1,2, Jan Niehaus3, Holger Lange1,2, and Horst Weller1,2,3 — 1Universität Hamburg, Institut für Physikalische Chemie, Grindelallee 117, 20146 Hamburg — 2The Hamburg Centre for Ultrafast Imaging, Luruper Chaussee 149, 22761 Hamburg, Germany — 3CAN GmbH Grindelallee 117 20146 Hamburg
We investigated clustered CdSe/CdS quantum dots/quantum rods (QDQRs) by time-resolved optical spectroscopy.
Power dependent measurements were conducted by excitation with different intensities and recording time traces of the photoluminescence (PL) decay simultaneously with the PL intensity. Increasing the excitation power generally increases the average exciton population per QDQR. We observe signatures of exciton-exciton interactions starting with exciton populations of one. This is tentatively assigned to an interaction between the excitons across the QDQRs. The non-monotonic increase of the PL intensity with excitation power in this regime supports the idea of a new, non-radiative multiexciton decay across the cluster.
To get more Information about this kind of interaction we apply Transient Absorption spectroscopy. By varying the pump wavelength, we are able to specifically excite core and shell and follow the subsequent relaxation.