title: Supramolecular control of charge-transfer dynamics on dye-sensitized nanocrystalline TiO2 films.
abstract: A [Ru(dcbpy)(2)(NCS)(2)] dye has been chemically modified by the addition of a secondary electron donor moiety, N,N-(di-p-anisylamino)phenoxymethyl. Optical excitation of the modified dye adsorbed to nanocrystalline TiO(2) films shows a remarkably long-lived charge-separated state, with a decay half time of 0.7 s. Semiempirical calculations confirm that the HOMO of the modified dye molecule is localised on the electron donor group. The retardation of the recombination dynamics relative to the unmodified control dye is caused by the increase in the spatial separation of the HOMO orbital from the TiO(2) surface. The magnitude of the retardation is shown to be in agreement with that predicted from the non-adiabatic electron-tunnelling theory.
authors.affiliation: Imperial College, Department of Chemistry, Centre for Electronic Materials and Devices, Exhibition Road, London SW7 2AY, UK.
authors.forename: Narukuni
authors.initials: N
authors.lastname: Hirata
authors.forename: Jean-Jacques
authors.initials: JJ
authors.lastname: Lagref
authors.forename: Emilio J
authors.initials: EJ
authors.lastname: Palomares
authors.forename: James R
authors.initials: JR
authors.lastname: Durrant
authors.forename: M Khaja
authors.initials: MK
authors.lastname: Nazeeruddin
authors.forename: Michael
authors.initials: M
authors.lastname: Gratzel
authors.forename: Davide
authors.initials: D
authors.lastname: Di Censo