Nanostructured Semiconductor Materials for Dye-Sensitized Solar Cells

Figure 6

Diagram of the electrical potential E levels involved in the process of photoactivated electron transfer (et) at the basis of the operation of a -DSC. The separation evidenced by the double arrow represents the open-circuit voltage of the -DSC. The latter parameter is determined by the difference between the Nernst level of the redox couple (/, in the given example) and the Fermi level of the -type semiconducting electrode (NiO in the reported example). Bent full arrows represent the dye-mediated et from the -type cathode to the oxidized form of the redox couple. The et process is catalysed by the dye-sensitizer D through the absorption of light with frequency . Dotted arrows and describe two processes of electronic recombination following the separation of charge induced by light absorption.