Recently, organic solar cells have attracted the attention of many researchers owing to flexibility, low cost, light weight and large-area applications, and significant improvement in the power conversion efficiency (PCE). In this work, we designed chains from organic compounds as donors and replaced the core unit in each series with a variety of acceptors in order to enhance their optical and electronic characterization and performance for power conversion ef- ficiencies in organic solar cells. We utilized density functional theory (DFT) and time-dependent density functional theory (TD-DFT) to investigate the geometry optimization by using the Gaussian 09 program. Both electronic and op- tical properties were determined, which involve the lowest unoccupied molecular orbital (LUMO) and the highest oc- cupied molecular orbital (HOMO) levels, the band gap energy, maximum absorption wavelength (λmax), open circuit voltage ( Voc), and light harvesting efficiency (LHE). Our evaluation denotes that the small compounds suggested are predicted to exhibit the best performance compared to the first series (SC1), like a lower band gap energy, a lower HOMO energy level, a greater absorption range, and a larger PCE.