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Published on: October 9, 2012
Optical properties of CdSe superlattices
Natalia Zaitseva1, Zu Rong Dai, Francisco R Leon
1Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94551, USA. zaitseva1@llnl.gov
Journal of the American Chemical Society
|July 21, 2005
Summary
Researchers grew 3D assemblies of cadmium selenide (CdSe) nanocrystals into faceted superlattices. These structures exhibit unique photoluminescence properties influenced by crystal size and arrangement, differing from amorphous layers and solutions.
Area of Science:
- Materials Science
- Nanotechnology
- Solid-State Physics
Background:
- Cadmium selenide (CdSe) nanocrystals are crucial in optoelectronic applications.
- Understanding nanocrystal assembly is key to controlling material properties.
- Previous studies often focused on amorphous or less ordered structures.
Purpose of the Study:
- To synthesize and characterize 3D, faceted assemblies of CdSe nanocrystals.
- To investigate the photoluminescence properties of these superlattices.
- To compare their optical behavior with disordered CdSe systems.
Main Methods:
- Synthesis of 3D, faceted CdSe nanocrystal assemblies.
- Characterization using optical microscopy, fluorescence microscopy, and transmission electron microscopy (TEM).
- Photoluminescence spectroscopy of individual superlattices, amorphous layers, and nanocrystal solutions.
Main Results:
- Successfully grew microscopic, faceted CdSe nanocrystal assemblies.
- Confirmed the formation of face-centered cubic (fcc) lattices from nearly single-size nanocrystals.
- Observed distinct photoluminescence spectra in superlattices compared to amorphous and solution-based samples.
Conclusions:
- 3D faceted CdSe nanocrystal superlattices can be precisely assembled.
- Photoluminescence characteristics are strongly dependent on superlattice structure and nanocrystal uniformity.
- Energy transfer mechanisms differ significantly between ordered superlattices and disordered CdSe systems.
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