New carbazole-based polymers for dye solar cells with hole-conducting polymer

Abstract

New carbazole-based polymers for use in dye-sensitized solar cells with p-conducting polymers have been synthesized. Further, a ruthenium-complex has been prepared to serve as electron/hole injecting dye in these cells. The energy gap has been determined by absorption and luminescence measurements of these materials in selected organic solvents. Cyclic voltammetry measurements have been performed to determine the energy level of the highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO). The energy levels of the polymers have been compared with the ones of a ruthenium-complex dye to check if a combination of these materials could make a promising couple in dye solar cells (DSC) with a hole-conducting polymer. Additionally, a combination of the new synthesized material with a commercial dye, cis-(NCS) 2bis(4,4′-dicarboxy-2,2′-bipyridine)-ruthenium(II), in its two-fold deprotonated form “N719” and a polymer, poly(3-octylthiophene) (P3OT), has been investigated.