The excitation wavelength and solvent dependance of the kinetics of electron injection in Ru(dcbpy)(2)(NCS)(2) sensitized nanocrystalline TiO2 films

Ultrafast transient absorption spectroscopy has been employed to monitor th e kinetics of photoinduced electron injection from Ru(2,2-bipyridyl-4,4'-di carboxylate),(NCS), (Ru(dcbpy)(2)(NCS)(2)) into nanocrystalline TiO2 films. This process found to exhibit nonexponential kinetics on the femtosecond/p icosecond timescales. A multiexponential analysis yielded lifetimes of <100 fs, 1.3 ps and 13 ps with relative amplitudes of 0.35, 0.22, 0.43 (+/-0.06 ) respectively. These kinetics were found to be independent of excitation w avelength, and to whether the film was immersed in organic solvent or expos ed to air.