If you have an ACS member number, please enter it here so we can link this account to your membership. (optional)

ACS values your privacy. By submitting your information, you are gaining access to C&EN and subscribing to our weekly newsletter. We use the information you provide to make your reading experience better, and we will never sell your data to third party members.



Novel Redox Couples Could Aid Solar Cells

Metallacarborane and sulfur compounds should improve on iodide systems in dye-sensitized solar cells

by Mitch Jacoby
April 12, 2010 | A version of this story appeared in Volume 88, Issue 15

Two research teams have independently created new redox couples—charge-shuttling electrochemical reagent pairs—that offer advantages over the conventional iodide-based redox couple used in dye-sensitized solar cells (DSCs). These cells typically consist of a porous dye-coated titanium dioxide electrode and a counter electrode bathed in an electrolyte solution containing the iodide/triiodide (I/I3 ) redox couple, which mediates the flow of current generated by the cells’ reduction and oxidation reactions. The I/I3 pair is commonly used because DSCs based on that couple exhibit relatively high stability and current-generating efficiency. But the iodide-based system is corrosive to some materials, such as silver, under consideration for commercial DSC use. In addition, I3 absorbs a portion of the visible spectrum, reducing DSC efficiency. The two newly described redox couples sidestep those problems. Tina C. Li, Joseph T. Hupp, and coworkers at Northwestern University developed Ni(IV)/Ni(III) bisdicarbollides as a potential iodide-couple replacement (J. Am. Chem. Soc. 2010, 132, 4580). And Mingkui Wang and Michael Grätzel of the Swiss Federal Institute of Technology, Lausanne, and coworkers developed a disulfide-thiolate redox couple based on a 5-mercapto-1-methyltetrazole dimer and its monomer anion (Nat. Chem., DOI: 10.1038/nchem.610).


This article has been sent to the following recipient:

Chemistry matters. Join us to get the news you need.