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Updated: Apr 16, 2026
12:56
Seeded Synthesis of CdSe/CdS Rod and Tetrapod Nanocrystals
Published on: December 11, 2013
40.6K
Dynamic Nuclear Polarization Enhanced 113Cd Solid-State Nuclear Magnetic Resonance Spectroscopy Reveals CdSe
Anuluxan Santhiran1,2, Jie Zhu3, Eunbyeol Gi1,2
1Division of Materials Science and Engineering, Ames National Laboratory, Ames, Iowa 50011, United States.
Summary
This study reveals that seemingly tetrahedral cadmium selenide (CdSe) nanocrystals actually have {100} surface facets, not {111} as previously thought. Advanced nuclear magnetic resonance (NMR) techniques were key to this discovery.
Area of Science:
- Materials Science
- Nanotechnology
- Solid-State Chemistry
Background:
- Surface structure is critical for semiconductor nanocrystal (NC) properties and growth.
- Characterizing NC surface facets requires advanced structural tools.
- Previous studies hypothesized tetrahedral CdSe NCs with {111} facets.
Purpose of the Study:
- Investigate the surface structure of CdSe NCs with triangular 2D projections.
- Determine the dominant surface facets of CdSe NCs using advanced spectroscopy.
- Clarify the shape and surface termination of so-called tetrahedral CdSe NCs.
Main Methods:
- Applied dynamic nuclear polarization (DNP) enhanced 113Cd and 77Se solid-state nuclear magnetic resonance (SSNMR) spectroscopy.
- Analyzed CdSe NCs exhibiting triangular 2D projections in transmission electron microscope (TEM) images.
- Studied both zinc-blende CdSe NCs and right trigonal bipyramidal (rTriBP) CdSe NCs.
Main Results:
- 113Cd NMR spectra contradicted the {111} facet hypothesis, indicating dominant {100} facets.
- DNP-enhanced 113Cd and 77Se SSNMR of rTriBP CdSe NCs also showed {100} surface facets.
- TEM images revealed similar triangular projections for both NC types.
Conclusions:
- So-called tetrahedral CdSe NCs are predominantly terminated by {100} facets.
- CdSe NCs with triangular projections likely share the rTriBP shape.
- Emphasizes the necessity of complementary techniques for accurate NC structural determination.
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