Tetrathiafulvalene as a one-electron iodine-free organic redox mediator in electrolytes for dye-sensitized solar cells
2012 (English)In: RSC Advances, ISSN 2046-2069, Vol. 2, no 3, 1083-1087 p.Article in journal (Refereed) Published
Tetrathiafulvalene (TTF) was investigated as an organic iodine-free redox mediator in electrolytes for dye-sensitized, nanocrystalline solar cells (DSCs) and was compared to the commonly used iodide/triiodide system. The TTF system studied was determined to be a one-electron transfer system, although potentially exhibiting three well-defined oxidation states. Despite the slightly positive redox potential of TTF, electrolytes with TTF displayed around 200 mV lower open-circuit voltage than the iodide/triiodide system. This can mainly be ascribed to a much shorter electron lifetime in the TiO2 film. Mass transport limitations for redox species in TTF-based electrolytes were found to be serious. Electrochemical impedance measurements (EIS) show that the charge-transfer resistance at the counter electrode in the electrolyte with TTF is considerably larger than for the iodide/triiodide system. In addition, the light absorption of the TTF-based electrolyte is stronger than that for the iodide/triiodide system. Thus, DSCs with TTF-based electrolytes show worse photovoltaic performance than those with iodide/triiodide-based electrolytes. The differences in I–V characteristics and charge-recombination behavior have also been elucidated.
Place, publisher, year, edition, pages
The Royal Society of Chemistry , 2012. Vol. 2, no 3, 1083-1087 p.
EFFICIENT, DERIVATIVES, COMPLEXES, COUPLE
IdentifiersURN: urn:nbn:se:kth:diva-63848DOI: 10.1039/C1RA00877CISI: 000299177000049ScopusID: 2-s2.0-84859201345OAI: oai:DiVA.org:kth-63848DiVA: diva2:482895
FunderSwedish Research CouncilKnut and Alice Wallenberg FoundationStandUp
Updated from e-pub ahead of print2012-01-242012-01-242016-04-26Bibliographically approved