title: Long-Range π-Conjugation in Phenothiazine-containing Donor-Acceptor Dyes for Application in Dye-Sensitized Solar Cells.
abstract: Four organic donor-π-bridge-acceptor dyes containing phenothiazine as a spacer and cyanoacrylic acid as an acceptor were synthesized and tested as sensitizers in dye-sensitized solar cells (DSCs). The influence of iodide- and cobalt-based redox electrolytes on the photovoltaic device performance was investigated. In these new dyes, systematic π-conjugation was extended by inserting one or two phenothiazine moieties and investigated within the context of the resulting photoinduced charge-transfer properties. A detailed investigation, including transient absorption spectroscopy and quantum chemical methods, provided important information on the role of extended π-conjugation on the photophysical properties and photovoltaic device performance. Overall, the results showed that the extension of π-conjugation by one phenothiazine unit resulted in the best device performance owing to reduced recombination rates, whereas extension by two phenothiazine units reduced dye adsorption on TiO2 probably owing to the increase in molecular size. The performance of the dyes in DSCs was found to be a complex interaction between dye structure and size.
authors.affiliation: Laboratory for Photonics and Interfaces, Institute of Chemical Sciences and Engineering, Swiss Federal Institute of Technology, 1015, Lausanne, Switzerland.|Amrita Centre for Nanosciences and Molecular Medicine, Amrita Vishwa Vidyapeetham, Amrita lane, Edappally, Cochin-41, 682041, India.
authors.forename: Mini P
authors.initials: MP
authors.lastname: Antony
authors.affiliation: Laboratory for Photonics and Interfaces, Institute of Chemical Sciences and Engineering, Swiss Federal Institute of Technology, 1015, Lausanne, Switzerland.
authors.forename: Thomas
authors.initials: T
authors.lastname: Moehl
authors.affiliation: Photochemical Dynamics Group, Institute of Chemical Sciences and Engineering, Ecole Polytechnique Fédérale de Lausanne, 1015, Lausanne, Switzerland.
authors.forename: Mateusz
authors.initials: M
authors.lastname: Wielopolski
authors.affiliation: Photochemical Dynamics Group, Institute of Chemical Sciences and Engineering, Ecole Polytechnique Fédérale de Lausanne, 1015, Lausanne, Switzerland.
authors.forename: Jacques-E
authors.initials: JE
authors.lastname: Moser
authors.affiliation: Amrita Centre for Nanosciences and Molecular Medicine, Amrita Vishwa Vidyapeetham, Amrita lane, Edappally, Cochin-41, 682041, India.
authors.forename: Shantikumar
authors.initials: S
authors.lastname: Nair
authors.affiliation: Solar Sys Co., Ltd., BI Center.
authors.forename: Yong-Jae
authors.initials: YJ
authors.lastname: Yu
authors.affiliation: Solar Sys Co., Ltd., BI Center.
authors.forename: Jong-Hyung
authors.initials: JH
authors.lastname: Kim
authors.affiliation: Solar Sys Co., Ltd., BI Center. kykay@ajou.ac.kr.|Department of Molecular Science and Technology, Ajou University, Suwon, 443-749, Korea. kykay@ajou.ac.kr.
authors.forename: Kwang-Yol
authors.initials: KY
authors.lastname: Kay
authors.affiliation: Korea Center for Artificial Photosynthesis, Department of Chemistry, Sogang University, Seoul, 121-742, Korea.
authors.forename: Young-Sam
authors.initials: YS
authors.lastname: Jung
authors.affiliation: Korea Center for Artificial Photosynthesis, Department of Chemistry, Sogang University, Seoul, 121-742, Korea.
authors.forename: Kyung Byung
authors.initials: KB
authors.lastname: Yoon
authors.affiliation: Laboratory for Photonics and Interfaces, Institute of Chemical Sciences and Engineering, Swiss Federal Institute of Technology, 1015, Lausanne, Switzerland.
authors.forename: Carole
authors.initials: C
authors.lastname: Grätzel
authors.affiliation: Laboratory for Photonics and Interfaces, Institute of Chemical Sciences and Engineering, Swiss Federal Institute of Technology, 1015, Lausanne, Switzerland. shaik.zakeer@epfl.ch.
authors.forename: Shaik M
authors.initials: SM
authors.lastname: Zakeeruddin
authors.affiliation: Laboratory for Photonics and Interfaces, Institute of Chemical Sciences and Engineering, Swiss Federal Institute of Technology, 1015, Lausanne, Switzerland. michael.graetzel@epfl.ch.
authors.forename: Michael
authors.initials: M
authors.lastname: Grätzel
mesh_terms: D004396:Coloring Agents / Q000737:chemistry*; D011211:Electric Power Supplies; D004579:Electron Transport; D008958:Models, Molecular; D008968:Molecular Conformation; D010640:Phenothiazines / Q000737:chemistry*; D012993:Solar Energy
chemical_list: D004396:Coloring Agents; D010640:Phenothiazines; C031637:phenothiazine
keywords: conjugation length; donor-acceptor; dye-sensitized solar cells; energy conversion; sensitizers