LAUSR

Heterogeneous charge transfer processes at sensitized wide bandgap semiconductor surfaces are imperative for both fundamental knowledge and technical applications. Herein, we focus on the investigation of carrier dynamics of a triphenylamine-based dye, LEG4, sensitized TiO2 (LEG4/TiO2) in contact with two types of electrolyte systems: pure cobalt-based electrolytes and in combination with an organic donor, tri(p-anisyl)amine (TPAA). Four different cobalt redox systems with potentials spanning a 0.3 V range were studied, and the carrier recombination and regeneration kinetics were monitored both at low and at high TiO2 (e–) densities (1.3 × 1018 and 1.3 × 1019 cm–3, respectively). The results reveal that the introduction of the TPAA intermediate more effectively suppress the recombination loss of TiO2 (e–) under high charge conditions, close to open-circuit, as compared to low charge conditions. As a result, the charge transfer from the cobalt complexes to the oxidized dyes is significantly improved by the...