Bis-tridentate Ru( ii ) sensitizers with a 4,4′,4′′-tricarboxy-2,2′:6′,2′′-terpyridine anchor ( i.e. tctpy) and a 2,6-dipyrazolyl pyridine ancillary ligand with either 5-dodecylthien-2-yl or t -butyl substituents at the central pyridyl unit and four distinctive perfluoroalkyl fragments ( e.g. CF 3 , C 3 F 7 , C 5 F 11 and C 7 F 15 ) at the terminal pyrazolyl sites were designed, synthesized and applied as sensitizers for the fabrication of dye-sensitized solar cells. All these sensitizers exhibited suitable optical properties and electrochemical characteristics. In addition, despite the TF- t Bu series of sensitizers with t -butyl substituents showing a lowered absorption extinction coefficient vs. their 5-dodecylthien-2-yl substituted counterparts ( i.e. TF-2′ series) in solution, their smaller molecular size allowed a larger dye loading on TiO 2 photoanodes, which offsets the inferior optical response and makes them the better DSC sensitizers. After appropriate selection of C 3 F 7 substituents, the sensitizer coded TF- t Bu_C 3 F 7 showed the highest overall efficiencies of J SC = 18.47 mA cm −2 , V OC = 767 mV, FF = 0.71 and PCE = 10.05% under simulated one sun irradiation, due to the fine balance between dye loading and reduced charge recombination. The corresponding enlarged solar cell module with an active area of 11.2 cm 2 also showed the best PCE of 7.55% under one sun irradiation with PCE reaching 12.70% under T5 lighting at 2400 lux.