The Excitation Wavelength and Solvent Dependance of the Kinetics of Electron Injection in Ru(dcbpy)₂(NCS)₂ Sensitized Nanocrystalline TiO₂ Films

Abstract

Electron transfer I Dye sensitisation I Nanocrystalline I Solar cells I Interfacial electron transfer Ultrafast transient absorption spectroscopy has been employed to monitor the kinetics of photoinduced electron injection from Ru(2,2-bipyridyl-4,4'-dicarboxylate)2(NCS)2 (Ru(dcbpy)2(NCS)2) into nanocrystalline Ti02 films.This process found to exhibit nonex- ponential kinetics on the femtosecond/picosecond 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 wave- length, and to whether the film was immersed in organic solvent or exposed to air.