A phenylenevinylene copolymer with perylene bisimde units as organic sensitizer for dye-sensitized solar cells

An alternating phenylenevinylene copolymer P with perylene bisimide units has been used as organic sensitizer to fabricate dye-sensitized solar cells (DSSCs) based on porous and TiCl4 modified TiO2 photoelectrodes. As a consequence of the compact layer formed by TiCl4 treatment to the porous TiO2 thin film layer, an efficient electron network was formed. Dark current measurements and electrochemical impedance spectra (EIS) suggested that modified photoelectrode significantly reduced the recombination rate of electrons with redox couple in the electrolyte due to the reduced bare FTO surface and longer electron lifetime as compared to the porous TiO2 photoelectrode. The power conversion efficiency of DSSCs utilizing this copolymer as sensitizer is about 2.60% and 3.98% with porous and modified TiO2 photoelectrodes, respectively.