Determining the core, corona, and total size of CdSeS/ZnS quantum dots by SEC/QELS and TEM

Leena Pitkänen, André M. Striegel*

*Corresponding author for this work

Research output: Contribution to journalArticleScientificpeer-review

3 Citations (Scopus)

Abstract

The size (hydrodynamic or Stokes radius, RH) of non-functionalized CdSeS/ZnS (core/shell) quantum dots (QDs) was characterized by size-exclusion chromatography with on-line quasi-elastic light scattering (SEC/QELS). Accurate determination of the size of QDs is important, because many of the optical properties of these materials are size dependent. A clear advantage of SEC/QELS over many batch techniques (e.g., QELS without separation) is the capability of the hyphenated technique to characterize the entire size range of a disperse sample, rather than merely providing a statistical average of the sizes present. Here, the SEC/QELS-determined RH values of CdSeS/ZnS QDs are compared to those determined by a traditional SEC experiment employing a calibration curve based on polystyrene standards, providing for the first reported study on SEC/QELS of non-functionalized QDs while also demonstrating the shortcomings of the widely-employed calibration curve approach. Furthermore, combining the RH of the QDs obtained by SEC/QELS with core size measurements derived from transmission electron microscopy allowed further calculation of the size of the QDs’ coronas. The latter result was found to be in close agreement to the previously measured dimension of the main corona constituent, as well as with the calculated size of this constituent.

Original languageEnglish
Pages (from-to)4003-4010
Number of pages8
JournalANALYTICAL AND BIOANALYTICAL CHEMISTRY
Volume408
Issue number15
DOIs
Publication statusPublished - 1 Jun 2016
MoE publication typeA1 Journal article-refereed

Keywords

  • Core and corona dimensions
  • Hydrodynamic radius
  • Quantum dots
  • Quasi-elastic light scattering
  • Size-exclusion chromatography
  • Transmission electron microscopy

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