Evaluation and prediction of dye-sensitized solar cells stability under different accelerated ageing conditions

Abstract

The present paper constitutes one of the few comprehensive studies found in literature on the stability of dye-sensitized solar cells (DSSCs) under different accelerated ageing conditions. Specifically, the accelerated ageing tests involved isothermal ageing at high or low temperature, thermal shock cycling, hydrothermal ageing, and reverse biasing of conventional DSSCs, fabricated using mainly commercially available materials, prepared for DSSCs application. One-diode model was in all cases applied to the characteristic curve of the solar cells, as a simplified version of the general transmission line model used in electrochemical impedance spectroscopy, for the fast and straightforward analysis of the charge transport and back-reaction kinetics in the DSSCs. A semi-analytical model (residual property model (RPM)) that was previously developed by the last author, was also applied, for the first time to solar cells, to predict the degradation of DSSCs performance due to their accelerated ageing. The results showed that moisture, in combination with high temperature, is the most critical environmental factor that leads to the degradation of DSSCs performance. In all cases of accelerated ageing, the stability of the solar cells seemed to be highly dependent on degradation/desorption phenomena of the conventional hydrophilic ruthenium (N719) dye from the TiO2 anode. Finally, it is worth mentioning that the RPM accurately predicted the degradation of DSSCs performance in all cases of accelerated ageing. The present paper reveals a simple but powerful approach for routine evaluation and prediction of the stability of DSSCs and, hopefully, of other solar cell technologies under various accelerated ageing conditions.