Theoretical studies on the structural and electronic properties of π-stacked cyano-thiophene-based molecules

The structure and electronic properties of cyano-thiophene-based molecular stacks is studied by means of quantum-mechanical calculations. The functionalization of thiophenes by cyano groups increases the dispersion interaction and promotes the parallel π-stacked arrangement of the molecules, which is essential to get efficient charge transport channels in the direction perpendicular to the plane of the thiophene rings. Moreover, we found that the π–π-stacking is the main driving force in the self-assembly of the molecules in the film. The present results are the basis for further studies of the hopping transport properties of this promising organic semiconducting material.