Sequential cation exchange in nanocrystals: Preservation of crystal phase and formation of metastable phases

Hongbo Li, Marco Zanella, Alessandro Genovese, Mauro Povia, Andrea Falqui, Cinzia Giannini, Liberato Manna*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

228 Scopus citations

Abstract

We demonstrate that it is possible to convert CdSe nanocrystals of a given size, shape (either spherical or rod shaped), and crystal structure (either hexagonal wurtzite, i.e., hexagonal close packed (hcp), or cubic sphalerite, i.e., face-centered cubic (fcc)), into ZnSe nanocrystals that preserve all these characteristics of the starting particles (i.e., size, shape, and crystal structure), via a sequence of two cation exchange reactions, namely, Cd 2+ →Cu+ →Zn2+. When starting from hexagonal wurtzite CdSe nanocrystals, the exchange of Cd2+ with Cu+ yields Cu2Se nanocrystals in a metastable hexagonal phase, of which we could follow the transformation to the more stable fcc phase for a single nanorod, under the electron microscope. Remarkably, these metastable hcp Cu2Se nanocrystals can be converted in solution into ZnSe nanocrystals, which yields ZnSe nanocrystals in a pure hcp phase.

Original languageEnglish (US)
Pages (from-to)4964-4970
Number of pages7
JournalNano Letters
Volume11
Issue number11
DOIs
StatePublished - Nov 9 2011

ASJC Scopus subject areas

  • Bioengineering
  • Chemistry(all)
  • Materials Science(all)
  • Condensed Matter Physics
  • Mechanical Engineering

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