Influence of molecular architecture on electronic and transport properties in sulfur-containing heterocyclic conducting polymers

We investigate a series of thiophene-based conjugated polymers built from monomers with extended ?-electron delocalization. The polymers are polythiophene, polythieno[3,2-b]thiophene and polydithieno[3,2-b;2',3'-d]thiophene. In order to obtain a better understanding of the evolution of the transport properties in this family of compounds, we present spectroscopic studies, including infrared, UV-visible and emission data, structural investigations and conductivity measurements, and compare them with theoretical parameter such as bandgaps and bandwidths as calculated by the Valence Effective Hamiltonian method. Polymer growth is optimized to prevent at best morphological differences between the three polymers