title: A supercooled imidazolium iodide ionic liquid as a low-viscosity electrolyte for dye-sensitized solar cells.
abstract: A series of allyl-functionalized imidazolium salts are reported, including 1-allyl-3-ethylimidazolium iodide and 1-allyl-3-propylimidazolium iodide, which have melting points close to room temperature and show typical properties of supercooled fluids if heated above their melting points. Their viscosities in the liquid state are considerably lower than the benchmark ionic liquid used in solar cells, viz., 1-propyl-3-methylimidazolium iodide. Electrolytes containing these new liquids provide excellent efficiencies and good stability in dye-sensitized solar cells when subjected to an accelerated-light soaking test at 60 degrees C. The structures of three of the new salts have been established in the solid state by single-crystal X-ray analysis.
authors.affiliation: Institute of Chemical Sciences and Engineering and Laboratory for Photonics and Interfaces, Ecole Polytechnique Fédérale de Lausanne (EPFL), CH 1015 Lausanne, Switzerland.
authors.forename: Zhaofu
authors.initials: Z
authors.lastname: Fei
authors.forename: Daibin
authors.initials: D
authors.lastname: Kuang
authors.forename: Dongbin
authors.initials: D
authors.lastname: Zhao
authors.forename: Cedric
authors.initials: C
authors.lastname: Klein
authors.forename: Wee Han
authors.initials: WH
authors.lastname: Ang
authors.forename: Shaik M
authors.initials: SM
authors.lastname: Zakeeruddin
authors.forename: Michael
authors.initials: M
authors.lastname: Grätzel
authors.forename: Paul J
authors.initials: PJ
authors.lastname: Dyson