Octapod-Shaped Colloidal Nanocrystals of Cadmium Chalcogenides via "One-Pot" Cation Exchange and Seeded Growth

Accepted Version of the publication: Nano Lett. 2010, 10, 9, 3770–3776. Publication Date: August 11, 2010. https://doi.org/10.1021/nl102539a

© 2010 American Chemical Society.

The growth behavior of cadmium chalcogenides (CdE = CdS, CdSe, and CdTe) on sphalerite Cu_2−xSe nanocrystals (size range 10−15 nm) is studied. Due to the capability of Cu_2−xSe to undergo a fast and quantitative cation exchange reaction in the presence of excessive Cd²⁺ ions, no Cu_2−xSe/CdE heterostructures are obtained and instead branched CdSe/CdE nanocrystals are built which consist of a sphalerite CdSe core and wurtzite CdE arms. While CdTe growth yields multiarmed structures with overall tetrahedral symmetry, CdS and CdSe arm growth leads to octapod-shaped nanocrystals. These results differ significantly from literature findings about the growth of CdE on sphalerite CdSe particles, which until now had always yielded tetrapod-shaped nanocrystals.