Designing indaceno thiophene-based three new molecules containing non-fullerene acceptors as strong electron...

Nowadays, scientists are trying to develop low-cost fullerene free acceptors for small organic photovoltaic cells in order to overcome the limitations of fullerene derivatives. Current research work deals with theoretical study on three non-fullerene acceptors based on indaceno, dithiophene core, and thiophene bridge units linked with dissimilar end non-fullerene groups which act as strong acceptor moieties. Different optoelectronic characteristics of the designed molecules were calculated and compared with the reference compound R (indaceno dithiophene-based fused ring acceptor) which is recently reported. Results shows that C₂ and C₃ exhibit broad absorption spectrum and lower band gap whereas C₂ and C₁ exhibit highest open-circuit voltages V_OC value with B3LYP and MPW1PW91 functionals respectively as compared with the R. All designed molecules have high dipole moment values, lower value of hole reorganization energy λ_h than electron reorganization energy λ_e which reflects that our designed acceptor molecules are good candidates for organic photovoltaics. Graphical abstract Absorption spectra of R and three designed non-fullerene acceptors with strong absorption band in the visible region of solar cells spectrum.