We have measured dynamics of the Ru(dcbpy) 2 (NCS) 2 [dcbpy = 4,4 ' -dicarboxy-2,2 ' -bipyridine] excited state and the dye cation on nanocrystalline TiO 2 film in the wavelength region 700-900 nm. The dye in ethanol solution and Ru(dcbpy) 2 (NCS) 2 sensitized nanocrystalline Al 2 O 3 films were used as non-injecting reference samples for excited state identification. For TiO 2 /Ru(dcbpy) 2 (NCS) 2 film the `reactant' decay and `product' formation kinetics observed at different probe wavelengths showed that the resolved transient absorption picosecond components (1.1+/-0.2), (12+/-2) and (100+/-5) ps are related to electron injection from the excited states of the dye to the semiconductor TiO 2 .