title: Influence of Phenylethynylene of Push-Pull Zinc Porphyrins on the Photovoltaic Performance.
abstract: A series of zinc porphyrin dyes YD22-YD28 were synthesized and used for dye-sensitized solar cells. Dyes YD26-YD28 consist of zinc porphyrin (ZnP) as core unit, arylamine (Am) as electron-donating group, and p-ethynylbenzoic acid (EBA) as an electron-withdrawing/-anchoring group. The dyes YD22-YD25 contain additional phenylethynylene group (PE) bridged between Am and ZnP units. The influence of the PE unit on molecular properties as well as photovoltaic performances were investigated via photophysical and electrochemical studies and density functional calculations. With the insertion of PE unit, the dyes YD22-YD25 possess better light-harvesting properties in terms of significantly red-shifted Q-band absorption. The conversion efficiencies for dyes YD22-YD25 are better than those of dyes YD26-YD28 owing to larger J(SC) output. Natural transition orbitals and Mulliken charge analysis were used to analyze the electron injection efficiency for porphyrin dyes upon time-dependent DFT calculations. The results indicated that insertion of additional PE unit is beneficial to higher J(SC) by means of improved light-harvesting property due to broadened and red-shifted absorption.
authors.affiliation: Department of Chemistry and Research Center for Sustainable Energy and Nanotechnology, National Chung Hsing University , Taichung 402, Taiwan.
authors.forename: Hsien-Hsin
authors.initials: HH
authors.lastname: Chou
authors.affiliation: Department of Chemistry and Research Center for Sustainable Energy and Nanotechnology, National Chung Hsing University , Taichung 402, Taiwan.
authors.forename: Kamani Sudhir K
authors.initials: KS
authors.lastname: Reddy
authors.affiliation: Department of Applied Chemistry and Institute of Molecular Science, National Chiao-Tung University , Hsinchu 300, Taiwan.
authors.forename: Hui-Ping
authors.initials: HP
authors.lastname: Wu
authors.affiliation: Department of Chemistry and Research Center for Sustainable Energy and Nanotechnology, National Chung Hsing University , Taichung 402, Taiwan.
authors.forename: Bo-Cheng
authors.initials: BC
authors.lastname: Guo
authors.affiliation: Department of Chemistry and Research Center for Sustainable Energy and Nanotechnology, National Chung Hsing University , Taichung 402, Taiwan.
authors.forename: Hsuan-Wei
authors.initials: HW
authors.lastname: Lee
authors.affiliation: Department of Applied Chemistry and Institute of Molecular Science, National Chiao-Tung University , Hsinchu 300, Taiwan.
authors.forename: Eric Wei-Guang
authors.initials: EW
authors.lastname: Diau
authors.affiliation: Institute of Chemistry, Academia Sinica , Taipei 115, Taiwan.
authors.forename: Chao-Ping
authors.initials: CP
authors.lastname: Hsu
authors.affiliation: Department of Chemistry and Research Center for Sustainable Energy and Nanotechnology, National Chung Hsing University , Taichung 402, Taiwan.
authors.forename: Chen-Yu
authors.initials: CY
authors.lastname: Yeh
keywords: Mulliken charge; charge transfer; density-functional; dye-sensitized solar cells; electron-donating; porphyrin sensitizers