Two new heteroleptic ruthenium-based dyes, SJW-El and CYC-B3 (see figure), with very high photon-to-current conversion efficiency are reported and their application in dye-sensitized solar cells (DSCs) described. The higher performance of SJW-E1 in DSCs is suggested to arise from successful molecular-engineering of the ancillary ligand, that is, two-dimensional conjugation enhancement and functional group substitution.