Carboxyl-modified conjugated polymer sensitizer for dye sensitized solar cells: significant efficiency enhancement

Abstract

A simple two step strategy was developed to introduce carboxyl groups via Vilsmeier–Haack formylation on the commercially available conjugated polymer BEHP-co-MEH PPV followed by Knoevenagel condensation. Adsorption of the carboxyl-modified polymer onto TiO₂ film and J–V curves were studied for the dye sensitized solar cell and compared with the base polymer BEHP-co-MEH PPV. Carboxyl-modification of BEHP-co-MEH PPV resulted in significant enhancement in the efficiency (3%), compared to the base polymer which showed an efficiency of only 0.3%. The details of the synthetic procedure, characterization and the photovoltaic property measurements are presented and discussed.