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Facet-to-facet Linking of Shape-anisotropic Colloidal Cadmium Chalcogenide Nanostructures
Published on: August 10, 2017
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Mapping the Atomistic Structure of Graded Core/Shell Colloidal Nanocrystals
Maksym Yarema1, Yunhua Xing1, Rainer T Lechner2
1Laboratory for Nanoelectronics, Department of Information Technology and Electrical Engineering, ETH Zurich, CH-8092, Zurich, Switzerland.
Scientific Reports
|September 17, 2017
Summary
This study quantifies the structure of graded semiconductor nanocrystals, enabling the design of highly luminescent core/shell emitters. We developed methods to precisely map compositional gradients for improved optical properties.
Area of Science:
- Materials Science
- Nanotechnology
- Optoelectronics
Background:
- Compositional gradients in core/shell semiconductor nanocrystals enhance optical properties.
- Previous structural characterization of these nanocrystals has been qualitative.
Purpose of the Study:
- To develop and demonstrate a quantitative approach for characterizing the structure of graded core/shell nanocrystals.
- To establish design rules for optimizing shell structures and achieving record luminescence.
Main Methods:
- Utilized multi-energy small-angle X-ray scattering (SAXS) and electron microscopy.
- Employed ab initio shape-retrieval analysis of X-ray scattering data.
- Generated 3D atomistic reconstructions of nanocrystals.
Main Results:
- Quantified the radial distribution of ZnSe in Ag-In-Se/ZnSe nanocrystals with sub-nanometer resolution.
- Determined the average nanocrystal shape.
- Calculated Zn diffusion and lattice mismatch within nanocrystal structures.
Conclusions:
- Established a quantitative method for nanocrystal structure determination.
- Provided insights into diffusion and lattice mismatch for graded nanocrystals.
- Proposed design principles for advanced luminescent core/shell nanocrystal emitters.
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