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Updated: May 10, 2026
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A Modular Microfluidic Technology for Systematic Studies of Colloidal Semiconductor Nanocrystals
Published on: May 10, 2018
Spectroscopy of colloidal semiconductor core/shell nanoplatelets with high quantum yield
M D Tessier1, B Mahler, B Nadal
1Laboratoire de Physique et d'Etude des Matériaux, CNRS, Université Pierre et Marie Curie , ESPCI, 10 rue Vauquelin, 75005, Paris, France.
Nano Letters
|June 5, 2013
Summary
Colloidal core/shell nanoplatelets offer improved light emission properties, showing reduced blinking and high quantum yields. These novel 2D materials are a promising alternative to traditional nanocrystals.
Area of Science:
- Materials Science
- Nanotechnology
- Quantum Optics
Background:
- Two-dimensional (2D) materials represent a novel class of nanostructures.
- Colloidal two-dimensional heterostructures, specifically core/shell nanoplatelets, have recently been synthesized.
- These structures are a significant advancement towards realizing colloidal quantum wells.
Purpose of the Study:
- To investigate the spectroscopic properties of novel colloidal core/shell CdSe/CdZnS nanoplatelets.
- To compare their optical characteristics with core-only nanoplatelets and other nanostructures.
- To assess their potential as an alternative to spherical or rod-shaped nanocrystals.
Main Methods:
- Synthesis of core/shell CdSe/CdZnS nanoplatelets.
- Photoluminescence spectroscopy at room and cryogenic temperatures.
- Single-particle spectroscopy to analyze emission time traces and spectral broadening.
- Optical spectroscopy to detect trap states.
Main Results:
- Achieved core/shell nanoplatelets with up to 80% quantum yield, approaching 100% at cryogenic temperatures.
- Observed reduced blinking and stable emission in single core/shell nanoplatelets compared to core-only ones.
- Demonstrated narrow emission spectra (FWHM ~20 nm) in solution, narrower than spherical or rod heterostructures.
- Identified increased exciton-phonon coupling in the shell as the cause of spectral broadening, not particle dispersity.
- Confirmed optical spectroscopy's utility in identifying shell deposition-induced traps.
Conclusions:
- Colloidal core/shell CdSe/CdZnS nanoplatelets exhibit superior spectroscopic properties, including high quantum yield and stable emission.
- Their narrow emission spectra and reduced blinking make them highly attractive for optoelectronic applications.
- These 2D heterostructures represent a promising new platform, potentially outperforming traditional nanocrystals.
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