Usually, iodine and iodide serve as an electrolyte. Chemists at the University of Basel have now been able to successfully replace the usual iodine-based electron transport system in copper-based DSCs by a cobalt compound. Tests showed no loss in performance.
The replacement of iodine significantly increases the sustainability of solar cells: "Iodine is a rare element, only present at a level of 450 parts per billion in the Earth, whereas cobalt is 50 times more abundant," explains the Project Officer Dr. Biljana Bozic-Weber. Furthermore, this replacement also removes one of the long-term degradation processes in which copper compounds react with the electrolyte to form copper iodide and thus improves the long-term stability of DSCs.