Document Type: Research Paper
The research in the organic π-conjugated molecules and polymers based on thiophenehas become one of the most interesting topics in the field of chemistry physics and materials science. These compounds have become the most promising materials for the optoelectronic device technology.. The use of low band gap materials is a viable method for better harvesting of the solar spectrum and increasing its efficiency. The control of the band gap of these materials is a research issue of ongoing interest. In this work, a quantum chemical investigation has been performed to explore the optical and electronic properties of a series of different compounds based onthiophene and carbazole. Different electron side groups were introduced to investigate their effects on the electronic structure. The theoretical knowledge of the HOMO and LUMO energy levels of the components is basic in studying organic solar cells so the HOMO, LUMO and Gap energy of the studied compounds have been calculated and reported. These properties suggest these materials as a good candidate for organic solar cells.