Conjugated molecules consisting of thienylenevinylene-co-cyanophenylene as donor materials for bulk heterojunction solar cells

Four conjugated compounds based on thienylenevinylene-co-cyanophenylene, P1, P2, P3 and P4 were successfully optimized by density functional theory (DFT) using B3LYP functional with 6-31G (d, p) basis set for all atoms. The study of the geometrical parameters (dihedral angles, bond lengths) showed that the structures of these oligomers are quasiplanar. Theoretical knowledge of the highest occupied molecular orbital (HOMO), the lowest unoccupied molecular orbital (LUMO) energy levels, the gap energy (Eg) and the open-circuit voltage (Voc) of the studied compounds were calculated and discussed using DFT calculations. The absorption properties of these compounds were calculated using TD/CAM-B3LYP/631G (d, p) method. The results of this work are a valuable data in designing and suggest these materials as a good candidates for organic bulk heterojunction solar cells.