Polarization-Selective Plasmon-Enhanced Silicon Quantum-Dot Luminescence

The photoluminescence intensity of silicon quantum dots is enhanced in a polarization-selective way by coupling to elongated Ag nanoparticles. The observed polarization dependence provides direct proof that the PL enhancement is due to electromagnetic coupling of the silicon quantum-dot emission dipoles with dipolar plasmon modes of the Ag nanoparticles. The polarization selectivity demonstrates the potential of engineered plasmonic nanostructures to optimize and tune the performance of light sources in a way that goes beyond solely enhancing the emission and absorption rates.