Probing the spontaneous emission dynamics in Si-nanocrystals-based microdisk resonators.
As a possible cavity quantum electrodynamical system, unlike III-V quantum dots, Si-NCs are not considered ideal emitters for emission rate enhancement observations (Purcell effect). Here, we report on direct measurements of spontaneous emission rate enhancement of Si-NCs embedded in a whispering-gallery mode resonator at room temperature. Using time-resolved microphotoluminescence experiments, we demonstrate important lifetime reductions (approximately 70%) for Si-NCs coupled to cavity modes with respect to uncoupled ones. Comparing experiments with the theoretical Purcell enhancement in a bad emitter regime, we estimate effective linewidths of approximately 10 meV through which Si-NC emitters are coupled to cavity photons. Finally, our study provides an alternative method for the estimation of subnatural linewidths of quantum dots at room temperature.
Pitanti
A
A
Nanoscience Lab., Department of Physics, University of Trento, via Sommarive 14, Povo (TN), Italy. pitanti@science.unitn.it
Ghulinyan
M
M
Navarro-Urrios
D
D
Pucker
G
G
Pavesi
L
L