title: (Dibenzoylmethanato)boron difluoride derivatives containing triphenylamine moieties: a new type of electron-donor/π-acceptor system for dye-sensitized solar cells.
abstract: (Dibenzoylmethanato)boron difluoride derivatives containing triphenylamine moieties were synthesized as a new type of electron-donor/π-acceptor system. These new compounds exhibited long-wavelength absorptions in the UV/Vis spectra, and reversible oxidation and reduction waves in cyclic voltammetry experiments. Their amphoteric redox properties are based on their resonance hybrid forms, in which a positive charge is delocalized on the triphenylamine moieties and a negative charge is localized on the boron atoms. Molecular orbital (MO) calculations indicate that their HOMO and LUMO energies vary with the number of phenylene rings connected to the difluoroboron-chelating ring. This is useful for optimizing the HOMO and LUMO levels to an iodine redox (I(-)/I3(-)) potential and a titanium dioxide conduction band, respectively. Dye-sensitized solar cells fabricated by using these compounds as dye sensitizers exhibited solar-to-electric power conversion efficiencies of 2.7-4.4 % under AM 1.5 solar light.
authors.affiliation: Department of Materials Science and Engineering, Graduate School of Engineering, Nagoya Institute of Technology, Gokiso, Showa-ku, Nagoya 466-8555 (Japan), Fax: (+81) 52-735-5407.
authors.forename: Yosuke
authors.initials: Y
authors.lastname: Mizuno
authors.forename: Yilihamu
authors.initials: Y
authors.lastname: Yisilamu
authors.forename: Tomoya
authors.initials: T
authors.lastname: Yamaguchi
authors.forename: Masaaki
authors.initials: M
authors.lastname: Tomura
authors.forename: Takashi
authors.initials: T
authors.lastname: Funaki
authors.forename: Hideki
authors.initials: H
authors.lastname: Sugihara
authors.forename: Katsuhiko
authors.initials: K
authors.lastname: Ono
keywords: boron; donor-acceptor systems; electron transfer; energy conversion; sensitizers