Colloidal CdSe/CdS Core/Crown Nanoplatelets for Efficient Blue Light Emission and Optical Amplification.
Carmelita Rodà1,2, Alessio Di Giacomo1,2, Lucía Camila Tasende Rodríguez1,2
1Physics and Chemistry of Nanostructures, Department of Chemistry, Ghent University, Krijgslaan 281-S3, 9000 Gent, Belgium.
Nano Letters
|May 1, 2023
Summary
We developed core/crown Cadmium Selenide nanoplatelets (NPLs) for efficient blue light emission. These NPLs overcome charge trapping issues, enhancing photoluminescence quantum efficiency for lighting and amplification applications.
Area of Science:
- Materials Science
- Nanotechnology
- Quantum Dots
Background:
- Cadmium Selenide nanoplatelets (NPLs) face challenges in UV/blue emission due to charge trapping.
- This trapping limits photoluminescence quantum efficiency (PL QE) and causes sub-bandgap emission in core-only NPLs.
Purpose of the Study:
- To synthesize and characterize core/crown CdSe/CdS NPLs.
- To investigate the effect of crown dimensions on optical properties.
- To evaluate NPLs for lighting and light-amplification applications.
Main Methods:
- Synthesis of 3.5 monolayer core/crown CdSe/CdS NPLs with varying crown dimensions.
- Photoluminescence quantum efficiency (PL QE) measurements.
- Time-resolved photoluminescence spectroscopy.
- Optical gain measurements.
Main Results:
- Core/crown CdSe/CdS NPLs exhibited saturated blue emission with PL QE up to 55%.
- Suppressed deep trapping and delayed emission led to monoexponential PL decay.
- Biexciton-mediated optical gain was observed with high coefficients and lower thresholds in crowned NPLs.
Conclusions:
- Core/crown CdSe/CdS NPLs offer a viable solution for efficient blue light emission.
- The results provide a roadmap for optimizing NPLs for optoelectronic devices.
- This work advances the potential of NPLs in lighting and light-amplification technologies.
