Fast and ultrafast photoinduced charge transfer processes in dye sensitized TiO2 electrodes

Donor-acceptor organic dyes are of interest in different solar applications, such as light absorbers in dye sensitized solar cells, or photosensitizers for photoinduced water splitting.1,2 Herein we present a series of dyes incorporating different heterocyclic units as sensitizers for TiO2 photoelectrodes prepared by screen-printing, investigated by means of steady-state optical techniques and femtosecond transient absorption spectroscopy. Sensitised electrodes were analysed and compared with the same dyes in solution, to unravel excited state deactivation pathways and charge carrier dynamics.