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We report on the synthesis, electrochemical, photophysical, and photovoltaic properties of a series of three organic dyads comprising a perylene monoimide (PMI) dye connected to a naphthalene diimide (NDI) or a fullerene (C60) for application in dye-sensitized solar cells (DSCs) with nanocrystalline NiO electrodes. It was found that the secondary electron acceptor (NDI or C60) in all the three dyads extends the charge separated state lifetime by about five orders of magnitude compared to the respective parent PMI dye. Nanosecond pump–probe experiments of the NiO/dyads in the presence of the electrolyte show that the reduction of triiodide by the secondary electron acceptor is slow in all the dyads, which we ascribe to a weak driving force for this reaction. This reaction is significantly faster with the cobalt electrolyte (tris(4,4′-di-tert-butyl-2,2′-bipyridine)cobalt(II/III)), whose driving force is larger; however, its …