Tuantum chemical investigations of new conjugated compounds based on dithiobithiophene as solar cells materials

摘要

Thanks to their specific properties, The research in the organic p-conjugated molecules and polymers has become one of the most interesting topics in the fields of chemistry physics and materials science., these compounds have become the most promising materials for the optoelectronic device technology such as solar cells. In this work, The theoretical ground-state geometry and electronic structure of the studied molecules were investigated by the DFT method at B3LYP level with 6-31G(d) basis set has been performed to explore the optical and electronic properties of a series of different compounds based on bithiophene. Different electron side groups were introduced to investigate their effects on the electronic structure. The effects of the ring structure and the substituents on the geometries and electronic properties of these materials were discussed with the aim to evidence the relationship between molecular structure and optoelectronic properties. The theoretical knowledge of the HOMO and LUMO energy levels of the components is basic in studying organic solar cells so the HOMO, LUMO, Gap energy and Voc (open circuit voltage) of the studied compounds have been calculated and reported. These properties suggest these materials as a good candidate for organic dye-sensitized solar cells.