Pereverziev M. Plasmon enhancement of luminescence of J-aggregates of thiacyanine and pseudoisocyanine dyes by silver and gold nanoparticles.

The thesis is devoted to studying the influence of a metal nanoparticle plasmon resonance on the luminescence properties of cyanine dye J-aggregates. It has been achieved 2-fold enhancement of thiacyanine (TC) J-aggregates luminescence in a water solution on 16 nm distance from silver nanoparticles. It has been proposed a theoretical description of exciton-plasmon interaction in the created system. It predicts 20-fold luminescence enhancement at optimal conditions. It has been found that efficiency of the plasmon enhancement of luminescence is affected by the density of contact between aggregates and nanoparticles, the frequency match of the plasmon and exciton bands and the exciton delocalization length. It has been shown that by the formation of TC J-aggregates and silver nanoparticles in polyelectrolyte layered films, 4-fold enhancement of the J-aggregates luminescence could be obtained. The 8-fold luminescence enhancement has been achieved for pseudoisocyanine (PIC) J-aggregates interacting with gold nanoparticles due to the larger exciton delocalization length in these aggregates. It has been found that the low luminescence quantum yield of PIC J-aggregates formed on polyelectrolyte films is caused by the exciton self-trapping processes due to strong exciton-phonon interaction.