The new donor-acceptor-donor (D-A-D) monomers have been studied using density functional theory (DFT) and time-dependent density functional theory (TD-DFT) methods to evaluate the optoelectronic and electronic properties for bulk heterojunction (BHJ) organic solar cells. The TD-DFT method is combined with a hybrid exchange-correlation functional using the B3LYP method in conjunction with a polarizable continuum model (PCM) and a 6–311G basis set to predict the excitation energies and absorption spectra of all monomers. The predicted bandgap (Eg) of the monomers decreasing in the following order D1