title: Enhancing the stability of porphyrin dye-sensitized solar cells by manipulation of electrolyte additives.
abstract: The use of porphyrin-based photosensitizers with superior light-harvesting properties has enabled the power conversion efficiency of dye-sensitized solar cells (DSCs) to reach 13 % under full sun illumination. However, a major limitation of such devices corresponds to the volatility of the solvent used so far for the electrolyte, which prevents practical applications. In this work, we describe a porphyrin-ionic liquid DSC, which not only affords the highest efficiency reported to date, but is also stable for more than 300 h under continuous full sun illumination at 60 °C. Furthermore, we identify a previously unreported pathway for device degradation, and show that the addition of N-methylbenzimidazole and a thiocyanate salt to the electrolyte is critical to obtaining long-lived devices.
authors.affiliation: Institut des Sciences et Ingénierie Chimiques, École Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne (Switzerland), Fax: (+41) 21-693-97-80.
authors.forename: Genevieve P S
authors.initials: GP
authors.lastname: Lau
authors.forename: Hoi Nok
authors.initials: HN
authors.lastname: Tsao
authors.forename: Chenyi
authors.initials: C
authors.lastname: Yi
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
mesh_terms: D001562:Benzimidazoles / Q000737:chemistry; D004396:Coloring Agents / Q000737:chemistry*; D011211:Electric Power Supplies; D004573:Electrolytes / Q000737:chemistry; D006146:Guanidines / Q000737:chemistry; D052578:Ionic Liquids / Q000737:chemistry; D010084:Oxidation-Reduction; D011166:Porphyrins / Q000737:chemistry*; D012993:Solar Energy; D013861:Thiocyanates / Q000737:chemistry
chemical_list: D001562:Benzimidazoles; D004396:Coloring Agents; D004573:Electrolytes; D006146:Guanidines; D052578:Ionic Liquids; D011166:Porphyrins; D013861:Thiocyanates; C054436:guanidine thiocyanate; C031000:benzimidazole
keywords: dye-sensitized solar cells; energy conversion; ionic liquids; porphyrinoids; stability