Probing plasmon polarization-mediated photoluminescence enhancement on metal-semiconductor hybrid optical nanostructures

The emission properties of CdSe quantum dots coupled to silver nanotriangles (AgNT) plasmon modes are reported. In the presence nanoparticles, the quantum dots exhibit 14-fold luminescence enhancements at an excitation wavelength of 442 nm which overlap with both AgNT dipole and quadrupole plasmon resonance frequencies. The distance-dependent transition between enhancements and quenching and the polarization dependence of plasmon-mediated CdSe emission are also investigated. The modifications on CdSe emission are explained in terms of electromagnetic coupling with the surface plasmon modes of nanoparticles and an increase in the excitation efficiency due to the enhanced local incident field intensity at the excitation wavelength. (C) 2011 Elsevier B.V. All rights reserved.