Solvent effects on adsorption kinetics, dye monolayer, and cell performance of porphyrin-sensitized solar cells

Abstract

The effect of three dye loading solvents (THF, ethanol, and n-butanol) on the adsorption kinetics, the binding mode of the dye molecules on the TiO₂ nanoparticles, and photovoltaic performance in dye-sensitized solar cells was reported. The kinetic study indicated that solvents greatly affected the adsorption amount and adsorption rate on the surface of TiO₂ nanoparticles. The adsorption data in THF, ethanol and n-butanol were analyzed by applying an intraparticle diffusion model, pseudo-first order model, and pseudo-second order model, respectively. It was found that adsorption rate was controlled by mass transfer processes. UV-vis spectra and ATR-FTIR spectra of porphyrin-coated electrodes were measured to study the intermolecular interaction and binding mode on TiO₂ films, respectively. Finally, the cell performance was tested under different solvents and the best efficiency of 8.18% was obtained when n-butanol was used as the solvent for dye-loading.