title: Understanding interfacial charge transfer between metallic PEDOT counter electrodes and a cobalt redox shuttle in dye-sensitized solar cells.
abstract: Conducting polymer poly(3,4-ethylenedioxythiophene) (PEDOT) doped with iron(III) tris-p-toluenesulfonate (PEDOT:Tos) having metallic conductivity was coated onto fluorine-doped tin oxide (FTO) glass and plain glass substrates and used as a counter electrode (CE) in a dye-sensitized solar cell (DSC) with a [Co(bpy)3](3+/2+) complex redox shuttle. DSCs with PEDOT:Tos/glass CE yielded power conversion efficiencies (PCE) of 6.3%, similar to that of DSCs with platinized FTO glass CE (6.1%). The PEDOT:Tos-based counter electrodes had 5 to 10 times lower charge-transfer resistance than the Pt/FTO CE in DSCs, as analyzed by impedance spectroscopy. More detailed studies in symmetrical CE-CE cells showed that the PEDOT:Tos layers are nanoporous. Not all internal area can be used catalytically under solar cell conditions and effective charge-transfer resistance was similar to that of Pt/FTO.
authors.affiliation: Department of Chemistry, Ångström Laboratory, and ‡Division of Solid-State Electronics, Ångström Laboratory, Uppsala University , Box 532, SE 751-20 Uppsala, Sweden.
authors.forename: Byung-wook
authors.initials: BW
authors.lastname: Park
authors.forename: Meysam
authors.initials: M
authors.lastname: Pazoki
authors.forename: Kerttu
authors.initials: K
authors.lastname: Aitola
authors.forename: Seunghee
authors.initials: S
authors.lastname: Jeong
authors.forename: Erik M J
authors.initials: EM
authors.lastname: Johansson
authors.forename: Anders
authors.initials: A
authors.lastname: Hagfeldt
authors.forename: Gerrit
authors.initials: G
authors.lastname: Boschloo