Designing and comparative analysis of 3D subphthalocyanines based non-fullerene acceptor molecules as an efficient material for organic solar cells

In recent epochs, the researchers are exploring for boost in the opto-electronic properties of active materials fabricated in Organic solar cell (OSCs). Herein, the eminent molecule Subphthalocyanines (SubPcs) is picked up as a reference molecule (R) and designed four 3D novel molecules by attaching electron withdrawing (EW) groups at six peripheral positions of R, giving them identity; M1, M2, M3, and M4. These 3D non-fullerene acceptors are theoretically analysed for UV-Vis absorption, frontier molecular orbitals (FMOs), density of states (DOS), transition density matrix (TDM), internal molecular reorganization energy, the binding energy, and interaction with renowned donor PTB7-Th. Comparative to molar absorption and HOMO/LUMO band gap of R (λ max = 650.2 nm and Eg = 1.633 eV), novel acceptors has better results i.e., λ max ranges from 733–801.5 nm and Eg ranges from 1.088–1.438 eV. While, the hole reorganization energy (i.e., in range of 0.111773–0.33002) and binding energies (i.e., 0.170–0.252) of all novel molecules is noticed lower comparative to R (λh = 0.178402 and Eb = 0.277, respectively). Exceptionally, M3 is prompted as promising light harvesting material with better molar absorption (λ max = 975.0 nm), lower band gap (Eg = 1.088 eV), less hole reorganization energy (λh = 0.033002 eV) and lower binding energy (0.182). Due to exceptional properties of M3 comparative to other designed acceptor molecules, it is analysed with donor PTB7-Th as donor/acceptor interface. Ultimately, it is proved to be efficient interface due to better charge transition. Meanwhile, all designing 3D acceptors are more efficient than R with exceptionally better opto-electronic properties of M3.