Femtosecond time-resolved x-ray photoelectron spectroscopy studies of charge transfer dynamics in novel photovoltaic systems

Interfacial charge transfer dynamics in dye-sensitized semiconductor films are studied by femtosecond time-resolved x-ray photoelectron spectroscopy. The experiments performed at the Linac Coherent Light Source demonstrate the potential of time-domain inner-shell photoionization studies to monitor charge migration in complex interfacial systems with femtosecond time resolution, chemical sensitivity and atomic specificity. Using this new technique, the transient oxidation state of N3 dye molecules adsorbed to nanocrystalline ZnO is monitored with unprecedented site selectivity, providing an upper bound for the interfacial electron-hole recombination rate.