title: Influence of sodium cations of N3 dye on the photovoltaic performance and stability of dye-sensitized solar cells.
abstract: We report on the effect of substituting the two tetrabutyl ammonium counter ions of the standard N719 dye by sodium ions on the performance and stability of dye-sensitized solar cells (DSCs). The disodium analogue of N719 in conjunction with a non-volatile electrolyte gives a conversion efficiency of 7.6% under standard global AM 1.5 sunlight. Devices maintain 99% of their initial performance after 1000 h under full sunlight aging at 50 degrees C. Electrochemical impedance spectroscopy and photovoltage transient decay studies reveal the evolution of the solar cell parameters during aging. Remarkably, upon aging a decrease in the rate of electron back reaction with the triiodide ions across the TiO(2)/electrolyte interface appears as well as enhanced electronic conduction in the TiO(2) film.
authors.affiliation: Laboratory of Process, Environment and Energy Engineering, Department of Chemical Engineering, Faculty of Engineering at the University of Porto, Rua Dr. Roberto Frias, s/n 4200-465 Porto, Portugal.
authors.forename: Luísa
authors.initials: L
authors.lastname: Andrade
authors.forename: Shaik M
authors.initials: SM
authors.lastname: Zakeeruddin
authors.forename: Mohammad K
authors.initials: MK
authors.lastname: Nazeeruddin
authors.forename: Helena Aguilar
authors.initials: HA
authors.lastname: Ribeiro
authors.forename: Adélio
authors.initials: A
authors.lastname: Mendes
authors.forename: Michael
authors.initials: M
authors.lastname: Grätzel
mesh_terms: D002412:Cations / Q000737:chemistry; D004396:Coloring Agents / Q000737:chemistry*; D004563:Electrochemistry; D004573:Electrolytes / Q000737:chemistry; D008567:Membranes, Artificial; D008968:Molecular Conformation; D009942:Organometallic Compounds / Q000737:chemistry*; D010777:Photochemistry; D012680:Sensitivity and Specificity; D012964:Sodium / Q000737:chemistry*; D012993:Solar Energy; D013861:Thiocyanates / Q000737:chemistry*; D013997:Time Factors; D014025:Titanium / Q000737:chemistry
chemical_list: D002412:Cations; D004396:Coloring Agents; D004573:Electrolytes; D008567:Membranes, Artificial; D009942:Organometallic Compounds; D013861:Thiocyanates; C506095:bis(2,2'-bipyridyl-4,4'-dicarboxylate)ruthenium(II) bis(tetrabutylammonium) bis(thiocyanate); C009495:titanium dioxide; D012964:Sodium; D014025:Titanium