Theoretical study on the geometries, electronic properties and absorption spectra of these five conjugated compounds based on thiophene are studied by Density Functional Theory (DFT) method at B3LYP level with 6-31G (d,p) basis set. The absorption properties were calculated starting at the optimized structures are calculated using TD-B3LYP/6-31G (d,p) method. The HOMO, LUMO, Gap energy, Voc, ionization potentials (IP)/electron affinities (EA) and λmax of these compounds have been calculated and reported in this paper. The objective of this study; is to evidence the relationship between chemical structure of these organic materials and their properties optoelectronic and photovoltaic of ways has conceive thereafter the compounds with effective character for solar cells.