Optoelectronic properties of acceptor fine-tuning via benzothiadiazole efficient D-A-A-based materials for solar cells with non-linear optical activity by TD-DFT method

[Display omitted] •BDT-based organic A1-A3 molecules are successfully designed and investigated for OSCs.•The simulated wavelength of A3 shows better absorption than the iBuBTDC and other molecules.•All the A1-A3 molecules are smaller Eg, compared to iBuBTDC.•All molecules could be used as promising candidates for OSCs. Here, attempts have been made to create and investigate acceptor tuning (A) materials via benzothiadiazole (BDT) that have higher efficiency for photovoltaic (PV). By structurally altering the BDT A-moiety of 2-((7-(N-(isobutyl)-benzothieno[3,2-b]-thieno[2,3-d]-pyrrol-2-yl)benzo[c][1,2,5]thiadiazol-4-yl)-methylene)malononitrile (iBuBTDC), three organic compoundsA1-A3 were designated for organic solar cells (OSCs) using the time-dependent density functional theory (TD-DFT) techniques. All A1-A3 molecules (1.85–1.93 eV) show a smaller energy gap (Eg) and exhibit the best outcomes for the open circuit voltage (VOC) (1.04–1.18 eV), normalized VOC (41.154 to 46.559 V) and FF (0.885 to 0.896 a.u.). The λ- and λ+ values of all compounds (0.1959, 0.1850, 0.1932 and 0.1877, 0.1659, 0.1641 eV) are found to be lower than the iBuBTDC (0.2122 and 0.1945 eV). Thefirst-order hyperpolarizability (β) and polarizability (α) were used to compute the Non-Linear Optical (NLO) characteristics of the A1-A3 molecules. Especially A3 could be very useful for future experimentally designed OSCs along with NLO applications.