An organic redox electrolyte to rival triiodide/iodide in dye-sensitized solar cells.
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.
Wang
Mingkui
M
Swiss Federal Institute of Technology, CH 1015, Lausanne, Switzerland.
Chamberland
Nathalie
N
Breau
Livain
L
Moser
Jacques-E
JE
Humphry-Baker
Robin
R
Marsan
Benoît
B
Zakeeruddin
Shaik M
SM
Grätzel
Michael
M