The effect of sulfonate groups on spectral-luminescent and photovoltaic properties of squarylium dyes

Abstract

Squarylium dye with sulfonate groups has been synthesized and its spectral-luminescent and photovoltaic properties have been studied in comparison with its non-functionalized analogue. It has been demonstrated that the introduction of sulfonate groups in the indolenine heterocycle of squarylium dyes results in the bathochromic shifts of the absorption and fluorescence band. In so doing, the fluorescence quantum efficiency and extinction coefficients of the dyes are virtually independent of the functional groups presence. A fluorescent quantum yield of dyes has been measured on the semiconductor and dielectric surface. It has been shown that the introduction of anchor sulfonate groups in the structure of the dye provides a more intimate contact with TiO2 nanoparticles which increases the number of charge carriers transferred from the dye to the semiconductor. This phenomenon can be effectively used for the dye-sensitized solar cells (DSSC).