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Updated: Jun 17, 2026
12:56
Seeded Synthesis of CdSe/CdS Rod and Tetrapod Nanocrystals
Published on: December 11, 2013
Ligand-controlled polytypism of thick-shell CdSe/CdS nanocrystals
Benoît Mahler1, Nicolas Lequeux, Benoît Dubertret
1Laboratoire de Physique et d'Etude des Matériaux, CNRS UPR5, ESPCI 10 rue Vauquelin, 75231 Paris, France.
Journal of the American Chemical Society
|January 2, 2010
Summary
Researchers synthesized thick-shell cadmium selenide/cadmium sulfide (CdSe/CdS) core/shell nanocrystals. They found that primary amines can induce structural changes in CdSe cores, influencing shell growth and leading to reduced blinking in the final nanocrystals.
Area of Science:
- Materials Science
- Nanotechnology
- Semiconductor Physics
Background:
- Cadmium selenide/cadmium sulfide (CdSe/CdS) core/shell nanocrystals are crucial for optoelectronic applications.
- Controlling crystal structure (wurtzite and zinc-blende) and shell thickness is vital for tuning nanocrystal properties.
- Ligand effects during synthesis can significantly impact nanocrystal structure and performance.
Purpose of the Study:
- To synthesize CdSe/CdS core/shell nanocrystals with thick CdS shells (5 nm).
- To investigate the influence of primary amines on the crystal structure of CdSe cores and CdS shell growth.
- To understand and control the formation of wurtzite (W) and zinc-blende (ZB) crystal structures in thick-shell nanocrystals.
Main Methods:
- Synthesis of CdSe/CdS core/shell nanocrystals with varying shell thicknesses.
- Utilized absorption spectra analysis to distinguish between W and ZB CdSe crystal structures.
- Investigated the role of primary amines during the CdS shell formation process.
Main Results:
- Successfully synthesized thick-shell CdSe/CdS nanocrystals in both W and ZB structures.
- Observed that primary amines can induce a structural transformation from ZB to W in CdSe cores.
- Demonstrated the growth of large-diameter (10 nm) perfect ZB CdSe core crystals and ZB thick-shell CdSe/CdS nanocrystals.
- Thick-shell CdSe/CdS quantum dots (QDs) exhibited significantly reduced blinking compared to thin-shell QDs, irrespective of crystal structure.
Conclusions:
- Primary amines play a critical role in controlling the crystal structure evolution of CdSe cores during thick CdS shell growth.
- This understanding enables the synthesis of high-quality, large-diameter ZB CdSe/CdS nanocrystals.
- Thick-shell CdSe/CdS QDs offer superior photostability with drastically reduced blinking, making them promising for advanced applications.
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