Three ‘D-π-A-π-A’ based dyes have been synthesized featuring MeO-, MeS- and Me2N- as donor residues and benzothiadiazole and cyanoacrylic acid residues as acceptor units. UV–vis spectroscopy, solution electrochemistry and DFT modelling indicated that the Me2N- residue has the most significant effect on optical and redox properties of a photosensitizer. DSSCs with the Me2N- functionalized dye gave the highest power conversion efficiency of the series (η = 5.61%), presumably due to the better donor ability of this unit, which promotes more effective intramolecular charge transfer (ICT) characteristics.