Ink-jet printing of electron donor/acceptor blends: Towards bulk heterojunction solar cells

We illustrate the ink-jet printing of a thin-film library of donor/acceptor systems useful in bulk heterojunction solar cells and their characterization utilizing a UV-vis/fluorescence plate reader and an optical profilometer. In addition, the morphology of the films has been examined by atomic force microscopy (AFM). The ink-jet processing technology allows printing of arrays of different donor/acceptor compositions on one substrate as well as the subsequent fast optical screening of the electron transfer processes. The investigated films consist of blends of a poly(methyl methacrylate) polypyridyl ruthenium(II) copolymer (RuPMMA) as electron donor material (p-type) and C(60)fullerene (PC60BM) as well as heptyl viologen (C-7-V) derivatives as electron acceptor materials (n-type).