The formation and luminescent properties of hybrid associates of colloidal Ag2S quantum dots with J-aggregates of trimethinecyanine dye

Abstract

Spectral patterns of hybrid association in the mixture of colloidal Ag 2 S quantum dots (QDs) with an average size of 2.5 to 0.3 nm with J-aggregates of a pyridinium salt of 3,3'-di(γ-sulphopropyl)-9-ethyl-4,5,4',5-dibenzothiacarbocyanine betaine (Dye), prepared by the sol-gel method in gelatin, are investigated. A conclusion about the preferential formation of cis-J-aggregates in the hybrid associates of Dye with Ag 2 S QDs is made. The effect of photosensitization of IR luminescence (1000-1300 nm) of colloidal Ag 2 S QDs by J-aggregates of Dye is revealed. On the basis of the results, a photosensitization scheme implying the resonance nonradiative transfer of the electronic excitation energy from cis-J-aggregates to the recombination luminescence centers of Ag 2 S QDs is suggested.

Fluorescent J-aggregates of cyanine dyes: basic research and applications review

“…The layer of carbon nanotubes can also be used to provide photoinduced conductance [222]. Wavelength conversion from visible absorption of J-aggregates to near-IR luminescence (1000-1300 nm) of colloidal Ag 2 S QDs was demonstrated [223].…”