Interaction of silicon photonic crystal nanocavities with colloidal lead sulphide nanocrystals for enhanced spontaneous emissions near 1550 nm at room temperature
We observe the weak coupling of lead sulphide nanocrystals to localized defect modes of 2-dimensional silicon nanocavities through enhancement of spontaneous emission. Cavity resonances characterized with the nanocrystals agree with cold-cavity measurements using integrated waveguides, but linewidths are broadened, perhaps due to limits of resolution in measurements. Selective isolation of nanocrystals only at the cavity further suppresses background photoluminescence. The theoretical enhancement is near 7, and the calculated Purcell factor is 65. These novel light sources operate near 1550 nm wavelengths at room temperature, permitting integration with current fiber communications networks.