Carbon nanotube doping of P3HT : PCBM photovoltaic devices

We have introduced functionalized single-walled carbon nanotubes (SWNTs) in bulk heterojunction polymer–fullerene photovoltaic devices. As compared with the pristine device with only fullerenes, the addition of SWNTs resulted in an improvement in both the short-circuit current density and the fill factor (FF). The best results were obtained with a P3HT/PCBM (1 : 1) mixture with 0.5 wt% of SWNTs under an open-circuit voltage ( V oc ) of 0.55 V, a short-circuit current density ( J sc ) of 4.95 mA cm −2 and a FF of 0.52 which led to a power conversion efficiency of 1.4% at illumination at 100 mW cm −2 AM1.5. This device takes advantage of the electron accepting feature of fullerenes and the high electron transport capability of SWNTs. The results indicate that the addition of nanotubes enhances the performance of polymer photovoltaic cells.