The development of stable and efficient solar cells with high power conversion efficiency is a subtle challenge. To compete by attaining a decreased band gap and uplifted power conversion efficiency, five new molecules (PM1-PM5) are formulated through the synergetic engineering of the terminal acceptor. The bond angle of the molecules PM1-PM5 ranges from (0.09 – 1.78 θ◦) and the bond length (1.41 – 1.43 Å). The computed molecules highlighted promising outcomes with a lowered band gap, bathochromic shift in absorption spectra, excellent excitation phenomenon, lower exciton binding energy, prominent LHE, and sufficient open circuit voltage required for commercialization. The MPW1PW91 functional with 6-31 G (d, p) methodology is selected for computational analysis. Among all customized chromophores, PM4 and PM5 manifested the lowest band gap (2.09 eV), absorption at 773 and 776 nm, and decreased excitation energy (1.60 eV). PM1 and PM4 demonstrated the highest dipole moment (13.22 D and 12.80 D in chloroform solvent). Furthermore, PM1 and PM2 outperformed in light-harvesting potential and manifested better charge transfer owing to their reduced reorganization energy of electrons and holes. Of all the designed molecules PM2, PM3, and PM4 (96.33, 96.43, 97.99) have the high NTOs percentage, showing their highest excitation of the electrons. The oscillatory strength of the molecules has values from 1.8043 to 2.8974. The comparable VOC (1.34-1.56 eV) was obtained by blending investigated chromophores with a PCBM acceptor. The percentage contribution of the donor, spacer, and acceptor shows that the highest donor contribution is given by the PM2 (HOMO 60.2% and LUMO 47.3%), while the spacer contribution is given by the PM5 (21.7% and 80.3%) and the acceptor contribution is highest by the PM2 (HOMO22.8% and 17.1%). To describe this in words, all individual molecules are well made with measured electron and photoelectric parameters and are provided as stable and sufficient materials to transport holes developed for the marketing of solar devices.
Tahira Faiz, Haq Nawaz Bhatti, Javed Iqbal and Muhammad Yaseen