Improving the photoluminescence quantum yields of quantum dot films through a donor/acceptor system for near-IR LEDs

Near-infrared light-emitting diodes (LEDs) show potential for telecommunication and medical applications. Quantum dot nanocrystals (QDs), specifically lead chalcogenides, are candidate LED materials since they exhibit tuneable luminescence across the whole near-infrared region, but their surface str...

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Bibliographic Details
Published in:Materials horizons 2019-01, Vol.6 (1), p.137-143
Main Authors: Davis, Nathaniel. J. L. K, Allardice, Jesse R, Xiao, James, Karani, Arfa, Jellicoe, Tom C, Rao, Akshay, Greenham, Neil C
Format: Article
Language:English
Subjects:
Crosslinking
Embedded systems
Light emitting diodes
Nanocrystals
Near infrared radiation
Organic light emitting diodes
Photoluminescence
Quantum dots
Quantum efficiency
Surface structure
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Summary:Near-infrared light-emitting diodes (LEDs) show potential for telecommunication and medical applications. Quantum dot nanocrystals (QDs), specifically lead chalcogenides, are candidate LED materials since they exhibit tuneable luminescence across the whole near-infrared region, but their surface structure must be carefully controlled to achieve efficient emission. We demonstrate an efficient donor-acceptor QD system by embedding low-energy QDs with high photoluminescence quantum efficiency (PLQE) into a matrix of higher-energy QDs with lower PLQE. We find that the overall PLQE of densely packed cross-linked QD films can be improved by the incorporation of a relatively small fraction of well-passivated acceptor QDs, also leading to improved LED performance. Excitations are transferred into the isolated low-energy acceptor QDs, where they recombine with high radiative efficiency. The PLQE of QD films can be increased by the incorporation of a relatively small fraction of well-passivated acceptor QDs.
ISSN:2051-6347
2051-6355
DOI:10.1039/c8mh01122b