How Reproducible are Electrochemical Impedance Spectroscopic Data for Dye-Sensitized Solar Cells?

Dye-sensitized solar cell (DSC) technology has been broadly investigated over the past few decades. The sandwich-type structure of the DSC makes the manufacturing undemanding under laboratory conditions but results in the need for reproducible measurements for acceptable DSC characterization. Electrochemical impedance spectroscopy (EIS) offers the possibility to study complex electronic systems and is commonly used for solar cells. There is a tendency in the literature to present impedance data only for one representative device. At the same time, as current density-voltage plots illustrate, measurements can vary within one set of DSCs with identical components. We present multiple DSC impedance measurements on "identical" devices prepared using two different dyes and present a statistical analysis regarding the reproducibility.