Effect of surface plasmon resonance in TiO2/Au thin films on the fluorescence of self-assembled CdTe QDs structure

23rd Congress of the International Commission for Optics

Moura, I.^1 ; Cerqueira, M.F.^1 ; Melnikau, D.^2 ; Savateeva, D.^2 ; Rakovich, Y.^2,3 ; Borges, J.^1 ; Vaz, F.^1 ; Vasilevskiy, M.^1

Centro de Física, Universidade Do Minho, Campus de Gualtar, Braga

4710-057, Portugal^1

Centro de Física de Materiales (MPC, CSIC-UPV/EHU), Donostia International Physics Center (DIPC), Donostia-San-Sebastian

E-20018, Spain^2

IKERBASQUE Basque Foundation for Science, Bilbao

48013, Spain^3

关键词: Energy transfer process;    Fluorescence lifetime imaging;    Local field enhancement;    Luminescent nanoparticle;    Plasmonic nanostructures;    Self assembled structures;    Steady state fluorescence properties;    Time-resolved emissions;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/605/1/012025/pdf
DOI  :  10.1088/1742-6596/605/1/012025

来源: IOP

【 摘 要 】

The exceptional properties of localised surface plasmons (LSPs), such as local field enhancement and confinement effects, resonant behavior, make them ideal candidates to control the emission of luminescent nanoparticles. In the present work, we investigated the LSP effect on the steady-state and time-resolved emission properties of quantum dots (QDs) by organizing the dots into self-assembled dendrite structures deposited on plasmonic nanostructures. Self-assembled structures consisting of water-soluble CdTe mono-size QDs, were developed on the surface of co-sputtered TiO2thin films doped with Au nanoparticles (NPs) annealed at different temperatures. Their steady-state fluorescence properties were probed by scanning the spatially resolved emission spectra and the energy transfer processes were investigated by the fluorescence lifetime imaging (FLIM) microscopy. Our results indicate that a resonant coupling between excitons confined in QDs and LSPs in Au NPs located beneath the self-assembled structure indeed takes place and results in (i) a shift of the ground state luminescence towards higher energies and onset of emission from excited states in QDs, and (ii) a decrease of the ground state exciton lifetime (fluorescence quenching).