Enhanced efficiency of plastic photovoltaic devices by blending with ionic solid electrolytes

One of the major technology bottlenecks of polymer photovoltaic cells is the low photoinduced current, due to the low carrier mobility and short exciton migration distance. In this letter we demonstrated that the electric current for polymer PV cells can be significantly enhanced by adding a small amount of ionic solid electrolyte. Heterojunction polymer photovoltaic devices, consisting of poly[2-methoxy-5-(2'-ethyl-hexyoxy)-1,4-phenylene vinylene] (MEH-PPV) C-60 and/or methanofullerene([6,6]-phenyl C61-butyric acid methyl ester) (PCBM) as the active materials, were fabricated. It has been found that the power efficiency of the organic was enhanced by blending ionic solid electrolyte, such as polyethylene oxide into the active layer. It is believed that the optimized polymer morphology, the improved electrical conductivity, and the in situ photodoping of MEH-PPV contribute to this enhancement of photovoltaic efficiency. (C) 2004 American Institute of Physics.