The continuously growing and wide-spread utilization of blends of organic electron and hole conducting materials comprises ambipolar field-effect transistors as well as organic photovoltaic cells. Structural, optical and electrical properties are investigated in blends and neat films of the electron donor material Cu-phthalocyanine (CuPc) together with fullerene C60 and Cu-hexadecafluorophthalocyanine (F16CuPc) as electron acceptor materials, respectively. The difference in molecular structure of the spherical C60 and the planar molecule CuPc leads to nanophase separation in the blend, causing charge carrier transport which is limited by the successful formation of percolation paths. In contrast, blends of the similar shaped CuPc and F16CuPc molecules entail mixed crystals, as can be clearly seen by X-ray diffraction measurements. We discuss differences of both systems with respect to their microstructure as well as their electrical transport properties.