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HL: Fachverband Halbleiterphysik
HL 24: Quantum dots: Optics
HL 24.1: Talk
Wednesday, March 29, 2023, 09:30–09:45, POT 151
Raman spectroscopic structure analysis of colloidal semiconductor core-shell quantum dots for the achievement of near-unity quantum efficiency — •Sandra Zech1,2, Sonja Krohn2, Hannes Van Avermaet3, Zeger Hens3, Jan Steffen Niehaus4, Janina Maultzsch1, and Holger Lange2 — 1Department of Physics, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany — 2Institute of Physical Chemistry, University of Hamburg, Hamburg, Germany — 3Physics and Chemistry of Nanostructures, Ghent University, Ghent, Belgium — 4Fraunhofer IPA Center for Applied Nano-Technology CAN, Hamburg, Germany
State of the art applications of quantum dots (QDs) require near-unity photoluminescence quantum yield (PLQY). This demand is rarely achieved and therefore the synthesis process is under constant optimization and nanocrystals consisting of a core with one or more shells of different materials are paving the way to achieve high PLQY. As those components have diverse lattice parameters, the induction of strain within the QDs is inevitable. Recently, we applied Raman spectroscopy for in depth structure characterization and a strain minimization approach to optimize the synthesis of InP/ZnSe/ZnS QDs towards near-unity PLQY. A similar effect plays a role in CdSe/CdS QDs when aiming for high PLQY. In these QDs, the formation of an alloyed interface between the CdSe core and CdS shell is assumed. By Raman spectroscopy, we are able to monitor the formation of these alloyed domains for different QD parameters and correlate it with the PLQY.