Experimental results and basic considerations concerning injection and transport of electrons in the dye-sensitized colloidal sponge-type anatase TiO2 electrode

Abstract

Electron transfer over the reaction distance corresponding to three saturated bonds occurs within 70 fs from the excited singlet state of anchored perylene chromophores to empty electronic levels in a sponge-type anatase TiO2 electrode. Injected electrons can be consumed in three different types of recombination processes at the interface with the electrolytic contact. Electron transport through the electrode follows a potential gradient that is set-up in the dark, corresponding to the difference between the Fermi levels of the two contact materials. It is dominated by multiple trapping and trap filling processes.