Abstract We report on the development of ruthenium dyes for the application in flexible ZnO based dye-sensitized solar cells. The ZnO based solar cells were prepared by electrodeposition using eosin Y as a structure-directing agent. The newly synthesized ruthenium dyes differed in the complexity of the extended π-donor-system and in their anchor moieties. As alternatives to carboxylic acids as anchor groups, dyes carrying ...