Stability of Dye Solar Cells with Photoelectrode on Metal Substrates

In this study, the stability of dye solar cells (DSCs) with different kinds of metals as the photoelectrode substrate is studied. Stainless steels (StSs), Inconel, and titanium substrates were tested to find stable substrate options. Photovoltaic characterization, electrochemical impedance spectroscopy (EIS), scanning electron microscopy, and substrate polarization measurements were used in the characterization. DSCs based on different grades of StS suffered from rapid degradation of efficiency within few hours in light soaking. Good stability was demonstrated with DSCs with Inconel and Ti photoelectrode substrates. The Inconel substrates have a thick passive oxide layer, which is likely related to good stability. However, according to the EIS analysis, the oxide layer of Inconel substrates increased resistive losses, which caused a lower fill factor and photovoltaic efficiency compared to the Ti-based cells.