The optoelectronic characteristics of fullerene-free photovoltaic compounds hold significant value in photonics and optoelectronics applications. To obtain the optimal candidate for modernized hi-tech purposes and to meet the rising requirement of photovoltaic blends for future solar cell applications, the current study centered on simulating and conducting DFT-analysis-of-synthesized anthradithiophene-based reference (RS) and nine tailored molecules (ZHS1–ZHS9). DFT and time-dependent-DFT methods were utilized to determine the photochemical, optoelectronic, and photovoltaic parameters such as absorption behavior, energy gaps, charge transfer capabilities, TDM analysis, reorganizational energy, charge transfer complex ZHS5:PC61BM study for ZHS1–ZHS9 and RS. The absorption maxima of ZHS1–ZHS9 molecules resulted in red shifting (680–816 nm) compared to the synthesized RS reference molecule (454 nm). The distribution of electron density on various molecular components is confirmed by the DOS and FMOs analysis. All tailored molecule possesses less energy gap, while ZHS5 gave the narrowest bandgap (1.21 eV) with less binding energy (0.19 eV) as well as excitation energy (1.02 eV) as compared to the reference molecule. The developed molecules carried larger open-circuit voltage (Voc = 1.04–1.88 V) and fill factor (FF=0.93) than the reference molecule Voc = 0.47 V and FF=0.803594, indicating that they are better suited to drawing more electric current. The ZHS5:PC61BM blend study and overall outcomes showed that these planned donor molecules are photo and thermally stable efficient solar cell candidates, and their ongoing research has the potential to result in high-performance photovoltaic systems. Thus, this work encouraged experimenters to create the suggested solar cell materials for cutting-edge optoelectronic high-tech uses.