title: An organic redox electrolyte to rival triiodide/iodide in dye-sensitized solar cells.
abstract: Dye-sensitized solar cells (DSCs) have achieved impressive conversion efficiencies for solar energy of over 11% with an electrolyte that contains triiodide/iodide as a redox couple. Although triiodide/iodide redox couples work efficiently in DSCs, they suffer from two major disadvantages: electrolytes that contain triiodide/iodide corrode electrical contacts made of silver (which reduces the options for the scale up of DSCs to module size) and triiodide partially absorbs visible light. Here, we present a new disulfide/thiolate redox couple that has negligible absorption in the visible spectral range, a very attractive feature for flexible DSCs that use transparent conductors as current collectors. Using this novel, iodide-free redox electrolyte in conjunction with a sensitized heterojunction, we achieved an unprecedented efficiency of 6.4% under standard illumination test conditions. This novel redox couple offers a viable pathway to develop efficient DSCs with attractive properties for scale up and practical applications.
authors.affiliation: Swiss Federal Institute of Technology, CH 1015, Lausanne, Switzerland.
authors.forename: Mingkui
authors.initials: M
authors.lastname: Wang
authors.forename: Nathalie
authors.initials: N
authors.lastname: Chamberland
authors.forename: Livain
authors.initials: L
authors.lastname: Breau
authors.forename: Jacques-E
authors.initials: JE
authors.lastname: Moser
authors.forename: Robin
authors.initials: R
authors.lastname: Humphry-Baker
authors.forename: Benoît
authors.initials: B
authors.lastname: Marsan
authors.forename: Shaik M
authors.initials: SM
authors.lastname: Zakeeruddin
authors.forename: Michael
authors.initials: M
authors.lastname: Grätzel