Electrochemical impedance spectroscopy: Fundamentals and application in dye-sensitized solar cells

Dye-sensitized solar cells (DSCs) have emerged in the photovoltaic scenario as one of the most promising low-cost alternative to the most employed solar devices based on silicon, especially for some niche application. Despite of the huge work carried out by scientists and researchers, detailed mechanism of some of the charge transfer processes occurring inside DSC5 is not still fully understood. Electrochemical impedance spectroscopy (EIS) gave an immense help in analyzing these processes, and has been widely employed in the DSCs to characterize novel materials and architectures. The scope of this Review is to provide an insight on the application of EIS for the study of DSCs. A general introduction of the technique will be given, followed by an in-depth review of its application in the DSC field. Finally, a brief discussion of future research directions concerning this topic will be presented.