Interplay between Auger and ionization processes in nanocrystal quantum dots

• Main Authors: Kraus, Robert M. (Author), Lagoudakis, Pavlos G. (Author), Muller, Josef (Author), Rogach, Andrey L. (Author), Lupton, John M. (Author), Feldmann, Jochen (Author), Talapin, Dimitri V. (Author), Weller, Horst (Author)
• Format: Article
• Language: English
• Published: 2005-07.
• Subjects: Article
• Online Access: Get fulltext

We study the interplay between Auger effects and ionization processes in the limit of strong electronic confinement in core/shell CdSe/ZnS semiconductor nanocrystal quantum dots. Spectrally resolved fluorescence decay measurements reveal a monotonic increase of the photoluminescence decay rate on excitation density. Our results suggest that Auger recombination accelerates ionization processes that lead to the occupation of dark, nonemissive nanocrystal states. A model is proposed in the quantized Auger regime describing these experimental observations and providing an estimate of the Auger assisted ionization rates.