PLASMON ENHANCED PHOTOLUMINESCENCE OF METAL NANOPARTICLES AND MONOLAYER MOLYBDENUM DISULFIDE STUDIED BY SINGLE PARTICLE SPECTROSCOPY

Abstract

Noble metal nanoparticles (NPs) exhibit excellent optical properties owing to their localized surface plasmon resonance (SPR). Plasmon coupling in NPs clusters enhances many optical responses such as two-photon photoluminescence (2PPL). In this thesis, different NPs clusters were investigated systematically in combination with FDTD calculations to study 2PPL enhancement mechanisms in terms of multiple aspects. We demonstrated that the 2PPL property can be strongly dependent on the geometry of Au nanorod dimers of different alignment angles. We also compared Au nanotriangle dimers with Au nanosphere dimers to demonstrate the influence of sharp tips on 2PPL signal enhancement. Next, Au nanorods-nanosphere heterodimers were investigated to study how different spatial arrangements influence their 2PPL properties. Plasmonic NPs also enhance the photoluminescence (PL) of adjacent 2-dimensional materials of intrinsic weak PL. In another part of this thesis, we investigated PL enhancement of monolayer molybdenum disulfide achieved by single Au nanoantennas of various morphologies.