Suchergebnisse

We present a theoretical study of the optical properties of a strongly coupled metallic dimer when an ensemble of molecules is placed in the inter-particle cavity. The linking molecules are characterized by an excitonic transition which couples to the Bonding Dimer Plasmon (BDP) and the Bonding Quadrupolar Plasmon (BQP) resonances, arising from the hybridization of the dipolar and quadrupolar modes of the individual nanoparticles, respectively. As a consequence, both modes split into two coupled plasmon-exciton modes, so called plexcitons. The Charge Transfer Plasmon (CTP) resonance, involving plasmonic oscillations of the dimer as a whole, arises when the conductance of the excitonic junction is above a threshold value. The possibility of exploiting plexcitonic resonances for sensing is explored in detail. We find high sensitivity to the environment when different dielectric embedding media are considered. Contrary to standard methods, we propose a new framework for effective sensing based on the relative intensity of plexcitonic peaks. © 2013 Optical Society of America. ; This project was supported by the Etortek project nanoiker from the Basque Government (BG), project FIS2010-19609-C02-01 from the Spanish Ministry of Science and Innovation and grant IT-366-07 from BG-UPV/EHU. O.P.G. acknowledges financial support from Vicerrectorado de Investigación of the University of the Basque Country (Ayudas Especialización Doctores). Computational resources were provided by DIPC (UPV/EHU, MICINN, BG, ESF). ; Peer Reviewed

Event: SPIE NanoScience + Engineering, 2011, San Diego, California, United States. ; In this work we study how plasmon modes of gold dimers are affected by a molecular bridge connecting both particles. Different models for the linker are considered to envisage the relation between the spectral changes observed in the extinction spectra and the electronic transport through the molecules. Depending on the size and nature of the molecular linker two different modes, known as BDP (Bonding Dimer Plasmon) and CTP (Charge Transfer Plasmon), are excited. Furthermore, when the molecular linker has an excitonic resonance, new spectral features emerge due to the plasmon-exciton coupling. ; This project was supported by the Etortek project inanoGUNE from the Basque Government (BG), project FIS2010-19609-C02-01 from the Spanish Ministry of Science and Innovation, grant IT-366-07 from BG-UPV/EHU and project CUBIHOLE EUI2008-03816 from European Union. Computational resources were provided by IZOSGIker (UPV/EHU, MICINN, BG, ESF). ; Peer reviewed