A novel immobilized fullerene–single wall carbon nanotube (C60–SWCNT) complex was synthesized via a microwave induced functionalization approach. It has been used as a component of the photoactive layer in a bulk heterojunction photovoltaic cell. As compared to a control device with only C60, the addition of SWCNTs resulted in an improvement of both the short circuit current density JSC and the fill factor (FF). This device takes advantage of the electron accepting feature of C60 and the high electron transport capability of SWCNTs. The results indicate that C60 decorated SWCNTs are promising additives for performance enhancement of polymer photovoltaic cells.