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Stimulated Emission and Lasing from Bulk CdSe Nanocrystals
Servet Ataberk Cayan1,2, Margarita Samoli1, Ivo Tanghe1,2,3
1Physics and Chemistry of Nanostructures, Ghent University, Gent 9000, Belgium.
The Journal of Physical Chemistry Letters
|September 19, 2024
Summary
Bulk nanocrystals (BNCs) now offer red light optical gain, extending their use in lasers. Cadmium selenide (CdSe) BNCs achieve this through an electron-hole plasma state, enabling tunable, nanosecond-lifetime lasers.
Area of Science:
- Materials Science
- Optoelectronics
- Semiconductor Physics
Background:
- Bulk nanocrystals (BNCs) are solution-processable optical gain materials.
- Current BNCs are limited to the green spectrum.
Purpose of the Study:
- Extend BNC optical gain to the red spectrum.
- Investigate the gain mechanism in red-emitting BNCs.
- Demonstrate red-emitting BNC lasers.
Main Methods:
- Quantitative time-resolved spectroscopy.
- Modeling nanocrystals as bulk semiconductors.
- Fabrication of photonic crystal surface emitting laser cavities.
Main Results:
- Cadmium selenide (CdSe) BNCs exhibit optical gain in the red spectrum.
- Gain originates from an unbound electron-hole plasma.
- Broadband gain with nanosecond lifetimes, not limited by Auger recombination.
- Optically pumped lasers demonstrated from 635 to 720 nm.
Conclusions:
- Compositional tuning of BNCs provides spectral versatility.
- BNCs maintain excellent gain metrics across different spectral regions.
- CdSe BNCs are promising for solution-processed red lasers.
