title: Role of hot singlet excited states in charge generation at the black dye/TiO2 interface.
abstract: Photoinduced electron transfer at low-band-gap ruthenium-based dye/TiO2 has been investigated by means of ultrafast transient absorption and DFT/TDDFT calculations. We demonstrate that although the charge generation mechanism is triplet mediated upon band gap excitation, as already proven in high band gap dyes such as the well-known N3 and N719, when excess energy is provided which allows to reach high energy singlet states still in the visible spectral range, ultrafast electron transfer takes place. No intersystem crossing process is observed and charge generation happens only from the singlet excited state.
authors.affiliation: Dipartimento di Fisica, Politecnico di Milano, Milano, Italy.
authors.forename: Ajay Ram Srimath
authors.initials: AR
authors.lastname: Kandada
authors.forename: Simona
authors.initials: S
authors.lastname: Fantacci
authors.forename: Simone
authors.initials: S
authors.lastname: Guarnera
authors.forename: Dario
authors.initials: D
authors.lastname: Polli
authors.forename: Guglielmo
authors.initials: G
authors.lastname: Lanzani
authors.forename: Filippo
authors.initials: F
authors.lastname: De Angelis
authors.forename: Annamaria
authors.initials: A
authors.lastname: Petrozza