title: Mapping the frontier electronic structures of triphenylamine based organic dyes at TiO2 interfaces.
abstract: The frontier electronic structures of a series of organic dye molecules containing a triphenylamine moiety, a thiophene moiety and a cyanoacrylic acid moiety have been investigated by photoelectron spectroscopy (PES), X-ray absorption spectroscopy (XAS), X-ray emission spectroscopy (XES) and resonant photoelectron spectroscopy (RPES). The experimental results were compared to electronic structure calculations on the molecules, which are used to confirm and enrich the assignment of the spectra. The approach allows us to experimentally measure and interpret the basic valence energy level structure in the dye, including the highest occupied energy level and how it depends on the interaction between the different units. Based on N 1s X-ray absorption and emission spectra we also obtain insight into the structure of the excited states, the molecular orbital composition and dynamics. Together the results provide an experimentally determined energy level map useful in the design of these types of materials. Included are also results indicating femtosecond charge redistribution at the dye/TiO(2) interface.
authors.affiliation: Department of Physics and Astronomy, Uppsala University, Box 516, SE-751 20 Uppsala, Sweden.
authors.forename: Maria
authors.initials: M
authors.lastname: Hahlin
authors.forename: Michael
authors.initials: M
authors.lastname: Odelius
authors.forename: Martin
authors.initials: M
authors.lastname: Magnuson
authors.forename: Erik M J
authors.initials: EM
authors.lastname: Johansson
authors.forename: Stefan
authors.initials: S
authors.lastname: Plogmaker
authors.forename: Daniel P
authors.initials: DP
authors.lastname: Hagberg
authors.forename: Licheng
authors.initials: L
authors.lastname: Sun
authors.forename: Hans
authors.initials: H
authors.lastname: Siegbahn
authors.forename: Håkan
authors.initials: H
authors.lastname: Rensmo