Peer-Reviewed Journal Details
Mandatory Fields
Leemans, Jari,Singh, Shalini,Li, Chen,Ten Brinck, Stephanie,Bals, Sara,Infante, Ivan,Moreels, Iwan,Hens, Zeger
2020
May
Journal Of Physical Chemistry Letters
Near-Edge Ligand Stripping and Robust Radiative Exciton Recombination in CdSe/CdS Core/Crown Nanoplatelets
Published
()
Optional Fields
11
9
3339
3344
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.
https://pubs.acs.org/doi/abs/10.1021/acs.jpclett.0c00870
10.1021/acs.jpclett.0c00870
Grant Details