Modified optoelectronic parameters by end-group engineering of A-D-A type non-fullerene-based small symmetric acceptors constituting IBDT core for high-performance photovoltaics

End-chain exploration of Non-Fullerene Acceptors is an efficient approach to amplify the photovoltaic properties of organic solar cells (OSCs). This green energy technology has attained tremendous consideration from scientists in the last few decades. Current investigations on OSCs have presented remarkable optoelectronic applications of A-D-A-type (A = acceptor and D = donor unit) molecules comprising seven newly designed molecules (INIC1–INIC7) due to their reduced band gaps, red-shifting of optical profiles towards the visible region, Light Harvesting Efficiency (LHE), improved dipole moment, ionization potential (IP), and electron affinity (EA). These parameters are analyzed using the DFT (density functional theory) and TD-DFT (time-dependent-density functional theory) approaches with varying functionals. Numerous specifications like orbital analysis including frontier molecular and natural transition orbital (FMO and NTO) evaluation, as well as density of states (DOS), transition density matrix (TDM), molecular electrostatic potential (MEP) investigation, and various other parameters have demonstrated that the refinement in these factors is attributed to the presence of an IBDT core with seven distinct NFFRAs (Non-Fullerene Fused Ring Acceptors). Amongst the designed molecules, several have exhibited superior features to the modeled molecule. The charge carrier mobilities of different proposed molecules have yielded magnificent results compared to the reference molecule, which is ultimately scrutinized by TDM graphs. The Voc (open-circuit voltage) of INIC5 capitulates preferable impact, which could lead to substitution of all-other molecules in the field of OSCs. Consequently, the impressive dipole moment cooperates in establishing the non-covalent interactions with chloroform leading to exceptional maneuverability. Nonetheless, various derived molecules have exhibited astonishing results concerning different examined parameters. •The DFT approach has analyzed seven symmetrically engineered acceptor molecules (INIC1–INIC7) by varying their terminal acceptors.•All these modified molecules own the least band gap (2.13eV-2.27eV) and the bathochromic shift in their wavelengths (686 nm to 744 nm) when compared to the reference (INIC).•The improved excitation and binding energies of designed molecules have introduced them as better molecules exhibiting enhanced maneuverability.•The fused ring core has played a crucial role in attaining the planarity bringin