title: Novel 4'-functionalized 4,4''-dicarboxyterpyridine ligands for ruthenium complexes: near-IR sensitization in dye sensitized solar cells.
abstract: Novel ruthenium complexes (MC113-MC117), obtained by modifying the terpyridine ligand of the black dye (N749), have been evaluated as sensitizers for dye sensitized solar cells (DSSCs). The modification is carried out by attaching selected chromophores, with varying electron donating strength, covalently to the central ring of the ligand. The complexes, compared to the parent dye, show red shifted absorption covering visible and near IR regions and higher molar extinction coefficients. We report in this work synthesis of a series of these ruthenium complexes with chromophores such as tert-butyl phenyl, triphenylamine, bithiophene, phenoxazine and phenothiazine. Detailed experimental characterization using optical, electrochemical and photovoltaic techniques has been carried out and complemented by density functional theory studies. The fill factors (ff) obtained for these dyes are larger than those of the parent black dye. In spite of these superior properties, the dyes show only moderate to good power conversion efficiencies. The possible reasons for this have been investigated and discussed.
authors.affiliation: Network of Institutes for Solar Energy, CSIR-Indian Institute of Chemical Technology, I&PC Division, Uppal Road, Tarnaka, Hyderabad-500 607, India. chandra@iict.res.in.
authors.forename: Ganesh
authors.initials: G
authors.lastname: Koyyada
authors.forename: Vinayak
authors.initials: V
authors.lastname: Botla
authors.forename: Suresh
authors.initials: S
authors.lastname: Thogiti
authors.forename: Guohua
authors.initials: G
authors.lastname: Wu
authors.forename: Jingzhe
authors.initials: J
authors.lastname: Li
authors.forename: Xiaqin
authors.initials: X
authors.lastname: Fang
authors.forename: Fantai
authors.initials: F
authors.lastname: Kong
authors.forename: Songyuan
authors.initials: S
authors.lastname: Dai
authors.forename: Niveditha
authors.initials: N
authors.lastname: Surukonti
authors.forename: Bhanuprakash
authors.initials: B
authors.lastname: Kotamarthi
authors.forename: Chandrasekharam
authors.initials: C
authors.lastname: Malapaka