Solution phase n-doping of C-60 and PCBM using tetrabutylammonium fluoride

The solution phase n-doping of C-60 and PCBM with tetrabutylammonium fluoride is shown to occur via an initial chemical reaction followed by electron transfer to a second fullerene molecule. The formation of ionic and radical intermediate species has significant implications for the use of ionically functionalized materials as electron-selective interface layers in OPVs.