Effects of PPV-g-PSFu Graft Copolymer on Morphology and Power Conversion Efficiency of Bulk Heterojunction Solar Cell Base on P3HT/C60 Blends

This research work concerns a study on the effect of donor-acceptor graft copolymer, namely poly-p-phenylene vinylene grafted with polystyrene fullerene (PPV-g-PSFu), on morphology and power conversion efficiency of bulk heterojunction solar cells (BHJ) based on P3HT/C60. The aim of this work is to investigate the effect of the graft copolymers content (10, 20 and 40 pph) on morphology and efficiency of the solar cells. The copolymer was mixed with P3HT and C60, by using a solution blending technique. The blend film was fabricated by using a spin coating technique. Power conversion efficiency of the cells was determined by using current density-voltage (J-V) measurements. From the results, it was found that power conversion efficiency (PCE) of various BHJ cells increased from 0.07 x10-4 % to 1.45 x10-4 % after the copolymer (20 pph) was added. The above change was discussed in the light of some changes in morphology of the P3HT/C60 blend. Atomic force micrographs (AFM) the various blends showed that, by adding the graft copolymer, the domain size decreased and finer dispersed particle morphology was obtained.