title: A designed bithiopheneimide-based conjugated polymer for organic photovoltaic with ultrafast charge transfer at donor/PC(71)BM interface: theoretical study and characterization.
abstract: In the current work, a series of bithiopheneimide (BTI)-based D-A copolymers were investigated based on the reported PDTSBTI (1) to screen excellent molecules toward organic photovoltaic (OPV) donor materials. It is found that the PCE based on the proposed derivative 4, where the silicon atom is replaced with vinyl and cyano groups on the DTS unit, shows a 70 percent improvement by Scharber diagrams compared with its prototype 1. Then, the charge transfer dynamics of 1/PC71BM and 4/PC71BM were investigated, including the intermolecular charge transfer (inter-CT) and recombination (inter-CR) rates. The theoretical data demonstrate that the ratio kinter-CT/kinter-CR of 4/PC71BM heterojunction is about 1 × 10(5) times higher than that of 1/PC71BM. These results clearly reveal that the designed donor molecule 4 will be a promising candidate for high-performance OPV device. We expect that this work from electron processing at the D/A interface may provide a theoretical guideline for further optimization and design of organic copolymer donor materials.
authors.affiliation: Institute of Functional Material Chemistry, Faculty of Chemistry, Northeast Normal University, Changchun 130024, Jilin, P. R. China. mzhang@nenu.edu.cn zmsu@nenu.edu.cn.
authors.forename: Shuang-Bao
authors.initials: SB
authors.lastname: Li
authors.forename: Yu-Ai
authors.initials: YA
authors.lastname: Duan
authors.forename: Yun
authors.initials: Y
authors.lastname: Geng
authors.forename: Hai-Bin
authors.initials: HB
authors.lastname: Li
authors.forename: Jian-Zhao
authors.initials: JZ
authors.lastname: Zhang
authors.forename: Hong-Liang
authors.initials: HL
authors.lastname: Xu
authors.forename: Min
authors.initials: M
authors.lastname: Zhang
authors.forename: Zhong-Min
authors.initials: ZM
authors.lastname: Su