A theoretical investigation for improving the performance of non-fullerene organic solar cells through side-chain engineering of BTR non-fused-ring electron acceptors

In the current quantum chemical study, indacenodithiophene donor core-based the end-capped alterations of the
reference chromophore BTR drafted eight A2-A1-D-A1-A2 type small non-fullerene acceptors. All the computational
simulations were executed under MPW1PW91/6-31G (d, p) level of DFT. The UV–Vis absorption, open
circuit voltage, electron affinity, ionization potential, the density of states, reorganization energy, orbital analysis,
and non-covalent interactions were studied and compared with BTR. Several molecules of our modeled
series BT1-BT8 have shown distinctive features that are better than those of the BTR. The open circuit voltage
(VOC) of BT5 has a favorable impact, allowing it to replace BTR in the field of organic solar cells. The charge
carrier motilities for proposed molecules generated extraordinary findings when matched to the reference one
(BTR). Further charge transmission was confirmed by creating the complex with a PM6 donor molecule. The
remarkable dipole moment contributes to the formation of non-covalent bond interactions with chloroform,
resulting in superior charge mobility. Based on these findings, it can be said that every tailored molecule has the
potential to surpass chromophore molecule (BTR) in OSCs. So, all tailored molecules may enhance the efficiency
of photovoltaic cells due to the involvement of potent terminal electron-capturing acceptor2 moieties. Considering
these obtained results, these newly presented molecules can be regarded for developing efficient solar
devices in the future.