title: Multiple dot-in-rod PbS/CdS heterostructures with high photoluminescence quantum yield in the near-infrared.
abstract: Pb cations in PbS quantum rods made from CdS quantum rods by successive complete cationic exchange reactions are partially re-exchanged for Cd cations. Using STEM-HAADF, we show that this leads to the formation of unique multiple dot-in-rod PbS/CdS heteronanostructures, with a photoluminescence quantum yield of 45-55%. We argue that the formation of multiple dot-in-rods is related to the initial polycrystallinity of the PbS quantum rods, where each PbS crystallite transforms in a separate PbS/CdS dot-in-dot. Effective mass modeling indicates that electronic coupling between the different PbS conduction band states is feasible for the multiple dot-in-rod geometries obtained, while the hole states remain largely uncoupled.
authors.affiliation: Physics and Chemistry of Nanostructures, Ghent University, Gent, Belgium.
authors.forename: Yolanda
authors.initials: Y
authors.lastname: Justo
authors.forename: Bart
authors.initials: B
authors.lastname: Goris
authors.forename: John Sundar
authors.initials: JS
authors.lastname: Kamal
authors.forename: Pieter
authors.initials: P
authors.lastname: Geiregat
authors.forename: Sara
authors.initials: S
authors.lastname: Bals
authors.forename: Zeger
authors.initials: Z
authors.lastname: Hens