title: Stable, high-efficiency ionic-liquid-based mesoscopic dye-sensitized solar cells.
abstract: Efficient and stable mesoscopic dye-sensitized solar cells (DSCs) introducing a low-viscosity binary ionic liquid (1-propyl-3-methyl-imidazolium iodide (PMII) and 1-ethyl-3-methyl-imidazolium tetracyanoborate (EMIB(CN)(4))) electrolyte in combination with a new high-molar-extinction-coefficient ruthenium complex, Ru(2,2'-bipyridine-4,4'-dicarboxylic acid)(4,4'-bis(2-(4-tert-butyloxy -phenyl)ethenyl) -2,2'-bipyridine) (NCS)(2), are demonstrated. The dependence of photovoltaic performance, charge transport and electron lifetime on the composition of the binary ionic-liquid electrolyte with different ratios of PMII/EMIB(CN)(4) were investigated by electrochemical impedance and photovoltage transient techniques. A photovoltaic conversion efficiency of 7.6 % was obtained under simulated full sunlight illumination, which is a record for solvent-free DSCs. These devices exhibit excellent stability at 80 degrees C in the dark or under visible-light soaking at 60 degrees C during 1000 h of accelerated tests.
authors.affiliation: Laboratory for Photonics and Interfaces, Institute of Chemical Sciences and Engineering, Ecole Polytechnique Fédérale de Lausanne, 1015 Lausanne, Switzerland.
authors.forename: Daibin
authors.initials: D
authors.lastname: Kuang
authors.forename: Cedric
authors.initials: C
authors.lastname: Klein
authors.forename: Zhipan
authors.initials: Z
authors.lastname: Zhang
authors.forename: Seigo
authors.initials: S
authors.lastname: Ito
authors.forename: Jacques-E
authors.initials: JE
authors.lastname: Moser
authors.forename: Shaik M
authors.initials: SM
authors.lastname: Zakeeruddin
authors.forename: Michael
authors.initials: M
authors.lastname: Grätzel
mesh_terms: D004396:Coloring Agents / Q000737:chemistry*; D004058:Diffusion; D017097:Electric Impedance; D004573:Electrolytes / Q000737:chemistry; D004583:Electrons; D007454:Iodides / Q000737:chemistry; D052578:Ionic Liquids / Q000737:chemistry*; D007700:Kinetics; D009842:Oligopeptides / Q000737:chemistry*; D010084:Oxidation-Reduction; D010666:Phenylpropionates / Q000737:chemistry; D012993:Solar Energy; D013997:Time Factors
chemical_list: D004396:Coloring Agents; D004573:Electrolytes; D007454:Iodides; D052578:Ionic Liquids; C473246:N-methyl piperazine-Phe-homoPhe-vinylsulfone phenyl; D009842:Oligopeptides; D010666:Phenylpropionates; C035253:3-phenylpropionic acid