Probing the spontaneous emission dynamics in Si-nanocrystals-based microdisk resonators

Area of Science:

• Quantum optics
• Materials science
• Nanotechnology

Background:

• Silicon nanocrystals (Si-NCs) are explored as potential cavity quantum electrodynamics systems.
• Traditionally, Si-NCs are not favored for observing emission rate enhancements (Purcell effect) compared to III-V quantum dots.

Purpose of the Study:

• To directly measure the spontaneous emission rate enhancement of Si-NCs within a whispering-gallery mode resonator.
• To investigate the coupling of Si-NCs to optical cavity modes at room temperature.

Main Methods:

• Time-resolved microphotoluminescence experiments were conducted.
• Si-NCs were embedded in a whispering-gallery mode resonator.
• Experimental results were compared with theoretical Purcell enhancement models.

Main Results:

• A significant reduction in Si-NCs lifetime (approximately 70%) was observed when coupled to cavity modes compared to uncoupled emitters.
• Effective linewidths of approximately 10 meV were estimated for Si-NC emitters coupled to cavity photons.
• The study confirmed the Purcell effect for Si-NCs in a cavity system.

Conclusions:

• Si-NCs can exhibit significant spontaneous emission rate enhancement in optical cavities.
• The findings provide an alternative method for estimating subnatural linewidths of quantum dots at room temperature.
• This work highlights the potential of Si-NCs in cavity quantum electrodynamics applications.