New π-Conjugated Materials Based on Thienopyrazine As Organic Dye Sensitizers for Organic Photovoltaic Device Applications

Abstract

In this work, new organic donor-π-acceptor molecules based on thienopyrazine is designed and reported. Diverse side based electron groups were presented to evaluate their impacts on the electronic and photovoltaic properties. The calculations of ground state were done by employing the DFT-B3LYP/6-31G(d,p) and the TD-DFT method for the excitation properties of the produced molecules. The results indicated that the "HOMO" and "LUMO" level are slightly changed and this suggests that there are different structures, playing important roles in improving the electronic and photovoltaic properties and in improving the electron accepting ability. The attained values of band gap together with the open circuit voltage are parameters that can be manipulated to improve the quality of solar cell applications. Moreover, the results showed that these molecules can be used for a solar cell as organic sensitizers due to probability of the electron injection process from the molecules to the conduction band of PC60BM, PC70BM or TiO2, in addition to the help of the compounds in designing more effective functional photovoltaic organic materials.