title: Dye-sensitized solar cells based on (donor-π-acceptor)2 dyes with dithiafulvalene as the donor.
abstract: Dipolar metal-free sensitizers (D-π-A; D=donor, π=conjugated bridge, A=acceptor) consisting of a dithiafulvalene (DTF) unit as the electron donor, a benzene, thiophene, or fluorene moiety as the conjugated spacer, and 2-cyanoacrylic acid as the electron acceptor have been synthesized. Dimeric congeners of these dyes, (D-π-A)(2), were also synthesized through iodine-induced dimerization of an appropriate DTF-containing segment. Dye-sensitized solar cells (DSSCs) with the new dyes as the sensitizers have cell efficiencies that range from 2.11 to 5.24 %. In addition to better light harvesting, more effective suppression of the dark current than the D-π-A dyes is possible with the (D-π-A)(2) dyes.
authors.affiliation: Institute of Chemistry, Academia Sinica, 128 Academia Road Sec. 2, Nankang Taipei 115 Taiwan (ROC), Fax: (+886)-2-2783-1237; Department of Chemistry, National Taiwan Normal University, 117, Taipei (Taiwan).
authors.forename: Ting-Hui
authors.initials: TH
authors.lastname: Lee
authors.forename: Chih-Yu
authors.initials: CY
authors.lastname: Hsu
authors.forename: You-Ya
authors.initials: YY
authors.lastname: Liao
authors.forename: Hsien-Hsin
authors.initials: HH
authors.lastname: Chou
authors.forename: Heather
authors.initials: H
authors.lastname: Hughes
authors.forename: Jiann T
authors.initials: JT
authors.lastname: Lin
keywords: dimerization; dyes/pigments; sensitizers; solar cells; sulfur heterocycles