Donor–acceptor–donor (D–A–D) molecules based on isoindigo as active material for organic solar cells

Two D–A–D systems involving benzofuran and dithienopyrrole as donor blocks and isoindigo as an acceptor unit have been synthesized and their electronic properties have been characterized by UV-Vis absorption spectroscopy and cyclic voltammetry. A preliminary evaluation of these compounds as active material in organic solar cells shows that the presence or absence of substitution at the nitrogen atom of indigo strongly affects the properties of the material and thus the performances of the resulting solar cells.