Abstract
In this work, conjugated polymers based on thiophene: polythiophene, poly (3-alkythiophene) and poly (alkylbithiophene) were characterized using the nuclear magnetic resonance (NMR) and UV spectroscopy to determine their spectroscopic properties. Then, their structural, electronic and vibrational properties were investigated using the density functional theory (DFT) calculations by the oligomeric approach. The optoelectronic properties were assessed, as well. The obtained results were discussed basing on the influence of substitution on the properties of the oligomers. The possibility of thiophene based oligomers photovoltaic application was also studied. We have shown that the octithiophene (8T) its derivatives have a very good conversion rate and it serves as a candidate for the photovoltaic application.