New approach for forming bulk-heterojunction solar cells comprising a π-conjugated polymer and C60

A new approach for high-efficiency polymer solar cells utilizing a BHJ active layer consisting of poly(3-hexylthiophene) (P3HT) as a donor and buckminsterfullerene, C-60 as an acceptor was demonstrated. P3HT/C-60 BHJ films were made possible by in situ formation Of C60 from solubilized addends, C-60-CpCO2R (R = Hex, Oct, and EHex) by retro Diels-Alder reaction at, or above, 100 degrees C. These cells exhibit enhanced performances compared to as-prepared P3HT/C-60 BHJ films, showing better morphology. (C) 2009 Published by Elsevier B.V.