Resonance Raman Study of New Pyrrole-Anchoring Dyes for NiO-Sensitized Solar Cells.

Three dyes for p-type dye-sensitized solar cells contg. a novel doubly anchored pyrrole donor group were synthesized and their solar cell performances were evaluated. Dye 1 was comprised of a phenyl-thiophene linker and a malononitrile acceptor, which was established as an effective motif in other push-pull dyes. Two B dipyrromethane analogs, dyes 2 and 3, were made with different linker groups to compare their effect on the behavior of these dyes adsorbed onto Ni oxide (dye|NiO) under illumination. The photoexcited states of dye|NiO were probed using resonance Raman spectroscopy and compared to dyes anchored using the conventional 4-aminobenzoic acid moiety (P1 and 4). All 3 components, the anchor, the linker and the acceptor group alter both the electronic structure following excitation and the overall solar cell performance. The bodipy acceptor gave a better performance than the malononitrile acceptor when the pyrrole anchor was used, which is the opposite of the tri-phenylamine push-pull dyes. The linker group has a large influence on the short-circuit current and efficiency of the p-type cells constructed. [on SciFinder(R)]