Computational study of organic small molecules based on imidazolinone for photovoltaic applications

Organic photovoltaic cells have received significant interest due to the low-cost manufacturing and compatibility to deposit on flexible substrate. However, this technology suffers from certain problems including lowest solar spectrum absorption by reason of the large band gap of donor materials. This could return to the lack of extensive studies concerning the effects of geometric structures and the energy levels associated with the synthesis of molecules. In this context, six organic pi-conjugated molecules based on imidazolinone with low band gap have been studied theoretically using quantum methods namely density functional theory (DFT) and time dependent-density functional theory (TD-DFT). The highest occupied molecular orbital (HOMO), lowest unoccupied molecular orbital (LUMO), and chemicals descriptors of these molecules have been examined in this work. Spectroscopic and electronic properties have been reported in order to study the parameters which affect photovoltaic efficiency. The calculated results of these compounds show a lower HOMO energy, large absorption spectra, and good theoretical open circuit voltage. The findings of this work are helpful to enhance the performance of bulk hetero junction organic solar cells (BHJ).