Preparation of organic bulk heterojunction photovoltaic cells by evaporative spray deposition from ultradilute solution

The preparation of an organic bulk heterojunction photovoltaic cell (OPC), having a thin layer consisting of a functionalized fullerene and a poly-p-phenylenevinylene (PPV) derivative from a highly diluted tetrahydrofuran solution, at the concentration below 1 ppm by the evaporative spray deposition from ultradilute solution (ESDUS) technique was discussed. It was found that the power conversion efficiency of the OPC prepared from 1:1 mixture solution of fullerene/PPV derivative at the concentration of 1 ppm was 0.69%. The preparation condition of ESDUS, spraying rate, temperature was optimized. The ESDUS was a very powerful tool for preparation of OPC by enlarging the extent of available materials.