title: Molecular engineering of push-pull porphyrin dyes for highly efficient dye-sensitized solar cells: the role of benzene spacers.
abstract: Porphyrins have drawn much attention as sensitizers owing to the large absorption coefficients of their Soret and Q bands in the visible region. In a donor and acceptor zinc porphyrin we applied a new strategy of introducing 2,1,3-benzothiadiazole (BTD) as a π-conjugated linker between the anchoring group and the porphyrin chromophore to broaden the absorption spectra to fill the valley between the Soret and Q bands. With this novel approach, we observed 12.75% power-conversion efficiency under simulated one-sun illumination (AM1.5G, 100 mW cm(-2)). In this study, we showed the importance of introducing the phenyl group as a spacer between the BTD and the zinc porphyrin in achieving high power-conversion efficiencies. Time-resolved fluorescence, transient-photocurrent-decay, and transient-photovoltage-decay measurements were employed to determine the electron-injection dynamics and the lifetime of the photogenerated charge carriers.
authors: Laboratory for Photonics and Interfaces, Institute of Chemical Sciences and Engineering, École Polytechnique Fédérale de Lausanne, 1015 Lausanne (Switzerland).
authors: Aswani
authors: A
authors: Yella
authors: Chi-Lun
authors: CL
authors: Mai
authors: Shaik M
authors: SM
authors: Zakeeruddin
authors: Shu-Nung
authors: SN
authors: Chang
authors: Chi-Hung
authors: CH
authors: Hsieh
authors: Chen-Yu
authors: CY
authors: Yeh
authors: Michael
authors: M
authors: Grätzel
keywords: dyes; energy conversion; porphyrinoids; sensitizers; solar cells