Controlling the interfacial concentrations of I3− and Li+ ions in illuminated ruthenium (II) complex-sensitized nanoparticulate TiO2 photoanodes chemically coated by poly(amidoamide) dendrimers generation 4.0 for enhancing the performance of dye-sensitize

Ruthenium (II) complex-sensitized TiO2 electrodes were chemically coated with NH2-terminated poly(amidoamide) dendrimers generation 4.0 in order to improve the performance of dye-sensitized solar cells using these photoanodes. The presence of dendrimers in these photodevices produced a global photovoltaic conversion efficiency of 6.78%, which was higher than that obtained for photocells without them (5.43%). The experimental results indicated that this treatment of the dye-sensitized TiO2 electrodes allowed for controlling the concentrations of I3− anions and Li+ cations into the dendrimers-modified dyed-TiO2 pores during operation of the photocells. Consequently, the charge interception reaction and the charge accumulation process at the conduction band of the TiO2 electrodes were simultaneously balanced by the establishment of I2···NH2, NH···I− and C = O···Li+ bonds at the branches of the confined dendrimers for increasing their global conversion efficiency.