The Dye-sensitized Solar Cells (DSSCs) efficiency is closely related to the photovoltaic properties of the used (donor-π-acceptor) dye. A series of four dyes, including thiophene bounded to the Oxadiazole, forms the π-spacer group while the Cyanoacrylic acid was used as the electron acceptor group A. These two groups stay unchanged for all proposed dyes where the electron donor group D is varied. All calculations are performed using the density functional theory (DFT) and time-density functional theory (TD-DFT). The critical parameters associated with the short circuit current density Jsc and the open-circuit voltage Voc have been investigated in detail. All the obtained results show that DM2 dye is the best candidate suitable to manufacture dye-based solar cells because of the better electronic properties, low energy gap, and optimal optical absorption bung (wide absorption band of 300 to 900 nm for the adsorbed dye) in neutral and doped states.