Development of efficient organic solar cells based on triarylamine- functionalized ruthenium dyes

New materials and structures have been developed for efficient organic solar cells such as dye-sensitized solar cells (DCSs) and organic thin-film solar cells (OPVs). In this paper, the authors discuss various strategies for achieving high conversion efficiency in organic solar cells, focusing on nanostructured materials. In the case of DSCs, TiO₂ nanotubes with suitable dimensions are expected to function as efficient charge transport layers because the rate constant of back electron transfer in a TiO₂ nanotube layer is smaller than that in a nanoparticule layer. A new derivative of triarylamine-functionalized ruthenium dyes is also synthesized, aimed at the efficient electron transfer from the dye to TiO₂. Furthermore, OPVs based on donor/acceptor (D/A) block copolymers are discussed, focusing on the exciton binding energy of donor and acceptor segments.