title: Conjugated or Broken: The Introduction of Isolation Spacer ahead of the Anchoring Moiety and the Improved Device Performance.
abstract: Acceptors in traditional dyes are generally designed closed to TiO2substrate to form a strong electronic coupling with each other (e.g., cyanoacrylic acid) to enhance the electron injection for the high performance of the corresponding solar cells. However, some newly developed dyes with chromophores or main acceptors isolated from anchoring groups also exhibit comparable or even higher performances. To investigate the relatively untouched electronic coupling effect in dye-sensitized solar cells, a relatively precise method is proposed in which the strength is adjusted gradually by changing isolation spacers between main acceptors and anchoring groups to partially control the electronic interaction. After an analysis of 3 different groups of 11 sensitizers, it is inferred that the electronic coupling should be kept at a suitable level to balance the electron injection and recombination. Based on a reference dye LI-81 possessing a cyanoacrylic acid as acceptor and anchoring group, both photocurrent and photovoltage are synergistically improved after the properties of isolation spacers were changed through the adjustment of the length, steric hindrance, and push-pull electronic characteristic. Accordingly, the rationally designed dye LI-87 with an isolation spacer of thiophene ethylene gives an efficiency of 8.54% and further improved to 9.07% in the presence of CDCA, showing a new way to develop efficient sensitizers.
authors.affiliation: Department of Chemistry, Hubei Key Lab on Organic and Polymeric Optoelectronic Materials, Wuhan University , Wuhan 430072, China.
authors.forename: Zhaofei
authors.initials: Z
authors.lastname: Chai
authors.affiliation: Department of Chemistry, Hubei Key Lab on Organic and Polymeric Optoelectronic Materials, Wuhan University , Wuhan 430072, China.
authors.forename: Sushu
authors.initials: S
authors.lastname: Wan
authors.affiliation: Department of Chemistry, Hubei Key Lab on Organic and Polymeric Optoelectronic Materials, Wuhan University , Wuhan 430072, China.
authors.forename: Cheng
authors.initials: C
authors.lastname: Zhong
authors.affiliation: Department of Chemistry, Hubei Key Lab on Organic and Polymeric Optoelectronic Materials, Wuhan University , Wuhan 430072, China.
authors.forename: Ting
authors.initials: T
authors.lastname: Xu
authors.affiliation: Department of Chemistry, Hubei Key Lab on Organic and Polymeric Optoelectronic Materials, Wuhan University , Wuhan 430072, China.
authors.forename: Manman
authors.initials: M
authors.lastname: Fang
authors.affiliation: Department of Chemistry, Hubei Key Lab on Organic and Polymeric Optoelectronic Materials, Wuhan University , Wuhan 430072, China.
authors.forename: Jinfeng
authors.initials: J
authors.lastname: Wang
authors.affiliation: Department of Chemistry, Hubei Key Lab on Organic and Polymeric Optoelectronic Materials, Wuhan University , Wuhan 430072, China.
authors.forename: Yujun
authors.initials: Y
authors.lastname: Xie
authors.affiliation: Department of Chemistry, Hubei Key Lab on Organic and Polymeric Optoelectronic Materials, Wuhan University , Wuhan 430072, China.
authors.forename: Yu
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Michael Grätzel Center for Mesoscopic Solar Cells, Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology , Wuhan 430072, China.
authors.forename: Anyi
authors.initials: A
authors.lastname: Mei
authors.affiliation: Michael Grätzel Center for Mesoscopic Solar Cells, Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology , Wuhan 430072, China.
authors.forename: Hongwei
authors.initials: H
authors.lastname: Han
authors.affiliation: Key Laboratory of Organic Solids, Beijing National Laboratory for Molecular Science, Institute of Chemistry, Chinese Academy of Sciences , Beijing 100190, China.
authors.forename: Qian
authors.initials: Q
authors.lastname: Peng
authors.affiliation: Department of Chemistry, Hubei Key Lab on Organic and Polymeric Optoelectronic Materials, Wuhan University , Wuhan 430072, China.
authors.forename: Qianqian
authors.initials: Q
authors.lastname: Li
authors.affiliation: Department of Chemistry, Hubei Key Lab on Organic and Polymeric Optoelectronic Materials, Wuhan University , Wuhan 430072, China.
authors.forename: Zhen
authors.initials: Z
authors.lastname: Li
keywords: dye-sensitized solar cells; electron injection and recombination; electronic coupling; isolation spacers; the structure−property relationship