Abstract
Unfused non-fullerene acceptors with the advantages of simple synthesis, high yields, and low cost have received a lot of interest in recent years. Herein, we designed five structures (UF-M1-UF-M5) with unfused non-fullerene acceptors coupled to electron-deficient quinoxaline (Qx) as the core unit via electron-donating cyclo-penta-dithiophene (CPDT) as the conjugated backbone by modification in UF-Qx-2Cl taken as reference. Among all, mPW1PW91 method predicted lambda(max) closest to the lambda(max) of UF-Qx-2Cl, so we implemented the mPW1PW91 method with a 6-31G(d,p) basis set for the optimization of designed geometries and their molecular electrostatic mapping (MEP). Further parameters like FMOs (frontier molecular orbitals), TDM (transition density matrix analysis), DOS (density of state analysis), electron-hole mobility rate (reorganization energies), dipole moment, and chemical quantum descriptive parameters were evaluated for organic photovoltaics. Among all, UF-M4 predicted better absorption in the gaseous and solvent phase (lambda(max) = 726 nm and 789 nm respectively), lower bandgap (E-g = 2.03 eV), higher dipole moment (1.99 and 5.33 debye in gaseous and solvent phase respectively), better quantum chemical descriptive parameters, and higher electron mobility rate (lambda(e) = 0.00766 eV). The results reveal that the acceptor molecule UF-M4 that has been created performs better in studies and better opportunities for organic-photovoltaics. To summarize, the unfused non-fullerene-based acceptor modification technique has shown effective in paving the way for the development of promising photovoltaic materials. All currently projected acceptor contributors (UF-M1-UF-M5) should be targeted to produce future competent organic photovoltaics.