Investigation of Exciton-Plasmon Interaction in 2D Hybrid Nanostructures

Two-dimensional hybrid nanostructures composed of plasmonic and excitonic nanoparticles attract great interest in the range of applications such as solar photovoltaics, photoelectrochemical catalysis and biosensing. We developed novel 2D hybrid structures via depositing close-packed monolayers of hydrophobic Zn-CuInS₂/ZnS quantum dots (CIS QDs) atop silver nanoplates (AgNPls) electrostatically deposited onto thin (∼20 nm) optically and e-beam transparent polycationic film. To study exciton-plasmon interaction the optical properties of these hybrid structures were compared with CIS QDs films without AgNPls. Photoluminescence quenching for samples with CIS QDs monolayer atop AgNPls was revealed. According to the time-resolved photoluminescence measurments plasmon-excitonic interaction leads to a pronounced lifetime shortening. We analyzed polarization photoluminescence spectra of the samples to reveal the resonance energy transfer from CIS QDs to AgNPls. We found that the ratio of p- to s-polarized emission light intensity is about 2 times less for samples with AgNPls, due to contribution from indirectly excited AgNPls plasmon scattering. CIS QDs demonstrate intrinsic reversible photoinduced PL quenching and we utilized variations in the quenching kinetics to reveal the FRET effect. A 30% reduction in the PL intensity of CIS QDs monolayers was observed , while CIS QDs atop AgNPls showed no noticeable tendency to PL quenching due to competitive FRET channel. Such hybrid exciton-plasmon nanostructures are perspective for nanophotonic devices with modulating emission. This work was partially supported by BRFFR X22Turk-004 and CHEMREAGENTS 2.1.04.01 projects.