A pair of isomeric ruthenium sensitizers BM1 and BM2, having TIP based ancillary ligands with a 9-phenylcarbazole tail at the α or β position of the thiophene unit, shows a distinguishable photovoltaic performance on DSCs (PCEs: 7.33% and 5.33% for BM1 and BM2 as compared with 6.07% for the standard N3-dye).