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Title
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Near-edge ligand stripping and robust radiative exciton recombination in CdSe/CdS Core/Crown nanoplatelets
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Author
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Abstract
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| We address the relation between surface chemistry and optoelectronic properties in semiconductor nanocrystals using core/crown CdSe/CdS nanoplatelets passivated by cadmium oleate (Cd(Ol)2) as model systems. We show that addition of butylamine to a nanoplatelet (NPL) dispersion maximally displaces ∼40% of the original Cd(Ol)2 capping. On the basis of density functional theory simulations, we argue that this behavior reflects the preferential displacement of Cd(Ol)2 from (near)-edge surface sites. Opposite from CdSe core NPLs, core/crown NPL dispersions can retain 45% of their initial photoluminescence efficiency after ligand displacement, while radiative exciton recombination keeps dominating the luminescent decay. Using electron microscopy observations, we assign this robust photoluminescence to NPLs with a complete CdS crown, which prevents charge carrier trapping in the near-edge surface sites created by ligand displacement. We conclude that Z-type ligands such as cadmium carboxylates can provide full electronic passivation of (100) facets yet are prone to displacement from (near)-edge surface sites. |
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Language
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English
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Source (journal)
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The journal of physical chemistry letters / American Chemical Society. - Washington, D.C, 2010, currens
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Publication
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Washington, D.C
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American Chemical Society
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2020
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ISSN
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1948-7185
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DOI
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10.1021/ACS.JPCLETT.0C00870
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Volume/pages
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11
:9
(2020)
, p. 3339-3344
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ISI
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000535177500024
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Full text (Publisher's DOI)
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Full text (open access)
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