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-sensitized solar cells

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.