Influence of plasmon effect on the sensitization of titanium dioxide by dye molecules

Abstract

The influence of the plasmon effect of metal nanoparticles on electron transfer from Eosin and Rhodamine B dyes to TiO2 was studied. Spectral-kinetic measurements showed that, compared to SiO2, not only the intensity but also the fluorescence lifetime of both dyes decreases on the TiO2 surface, which indicates the charge transfer from the dye to the semiconductor. In the presence of core@shell (Ag@TiO2) plasmon nanostructures, an intensification of the fluorescence of both dyes is observed, as well as a decrease in the duration of the dyes emission. The optimal concentration for which the maximum plasmon effect was recorded is 3 wt% of Ag@TiO2. The plasmon effect also leads to an increase in the efficiency of sensitization of the semiconductor by molecules of the dyes under study, which is expressed as an increase in the photovoltaic and charge-transport characteristics of the semiconductor films. The results obtained on the plasmon effect on the charge transfer process in the dye/semiconductor system can be used in the development of devices for photovoltaics, photocatalytic, and optoelectronic elements.