title: Effect of electron-donor ancillary ligands on the heteroleptic ruthenium complexes: synthesis, characterization, and application in high-performance dye-sensitized solar cells.
abstract: Three heteroleptic ruthenium complexes, RC-15, RC-16 and RC-22, with sulfur- or oxygen-containing electron-donor, phenylpyridine-based ancillary ligands, are synthesized. The influence of the different electron donors-the acyclic electron donors methylthio and methoxyl, and the cyclic electron donor methylenedioxy-on the photophysical and electrochemical behavior in dye sensitizers and photovoltaic performance in DSSCs are investigated. Compared to the conventional dye N3, all the dyes demonstrate superior performance in the form of molar absorptivity, photocurrent density (J(SC)) and conversion efficiency (η). The DSSCs based on RC-15 and RC-16, with only a two-atom change in the acyclic electron donor, exhibit analogous photovoltaic performance (9.28% for RC-15 and 9.32% for RC-16). The highest photocurrent density (19.06 mA cm(-2)) and conversion efficiency (9.74%) are recorded for RC-22, which contains the cyclic electron donor. Transient absorption (TAS) and time-resolved photoluminescence (TRPL) measurements are carried out to investigate the sensitizers' regeneration and the behavior of excited electron decay kinetics. Furthermore, electrochemical impedance spectroscopy (EIS) is operated to explain the charge recombination and the electron lifetime. These consequences reveal substantial dependences on the different configurations of the electron-donor ancillary ligands.
authors.affiliation: Key Laboratory of Novel Thin Film Solar Cells, Institute of Applied Technology, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei 230031, P. R. China. kongfantai@163.com sydai@ncepu.edu.cn and University of Science and Technology of China, Hefei 230026, P. R. China.
authors.forename: Wang-Chao
authors.initials: WC
authors.lastname: Chen
authors.affiliation: Key Laboratory of Novel Thin Film Solar Cells, Institute of Applied Technology, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei 230031, P. R. China. kongfantai@163.com sydai@ncepu.edu.cn.
authors.forename: Fan-Tai
authors.initials: FT
authors.lastname: Kong
authors.affiliation: Key Laboratory of Novel Thin Film Solar Cells, Institute of Applied Technology, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei 230031, P. R. China. kongfantai@163.com sydai@ncepu.edu.cn and University of Science and Technology of China, Hefei 230026, P. R. China.
authors.forename: Xue-Peng
authors.initials: XP
authors.lastname: Liu
authors.affiliation: Key Laboratory of Novel Thin Film Solar Cells, Institute of Applied Technology, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei 230031, P. R. China. kongfantai@163.com sydai@ncepu.edu.cn.
authors.forename: Fu-Ling
authors.initials: FL
authors.lastname: Guo
authors.affiliation: Key Laboratory of Novel Thin Film Solar Cells, Institute of Applied Technology, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei 230031, P. R. China. kongfantai@163.com sydai@ncepu.edu.cn.
authors.forename: Li
authors.initials: L
authors.lastname: Zhou
authors.affiliation: Key Laboratory of Novel Thin Film Solar Cells, Institute of Applied Technology, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei 230031, P. R. China. kongfantai@163.com sydai@ncepu.edu.cn.
authors.forename: Yong
authors.initials: Y
authors.lastname: Ding
authors.affiliation: Key Laboratory of Novel Thin Film Solar Cells, Institute of Applied Technology, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei 230031, P. R. China. kongfantai@163.com sydai@ncepu.edu.cn.
authors.forename: Zhao-Qian
authors.initials: ZQ
authors.lastname: Li
authors.affiliation: Key Laboratory of Novel Thin Film Solar Cells, Institute of Applied Technology, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei 230031, P. R. China. kongfantai@163.com sydai@ncepu.edu.cn and Beijing Key Laboratory of Novel Thin Film Solar Cells, North China Electric Power University, Beijing 102206, P. R. China.
authors.forename: Song-Yuan
authors.initials: SY
authors.lastname: Dai