title: Novel Copolymers Based Tetrafluorobenzene and Difluorobenzothiadiazole for Organic Solar Cells with Prominent Open Circuit Voltage and Stability.
abstract: Two novel copolymers based on benzothiadiazole (BT) or difluorobenzothiadizole (ffBT) with 2,2'-(perfluoro-1,4-phenylene)dithiophene (2TPF4), namely PBT-2TPF4 and PffBT-2TPF4, are synthesized for applications in polymer solar cells (PSCs). A noticeably high open-circuit voltage (Voc) of 1.017 and 0.87 V are achieved for PffBT-2TPF4 and PBT-2TPF4-based devices, respectively. Although only a moderate efficiency (5.7%) of PBT-2TPF4-based devices is obtained, it is first demonstrated that 2TPF4 is a promising acceptor block for construction of the donor copolymers which possess high Voc, prominent crystallinity, and long-term stability, simultaneously. Besides, two thienyl flanking the tetrafluorophenylene can decrease torsion angle between conjugated units, resulting in a high coplanar structure of copolymers to enhance their charge carrier mobility. The findings may open a promising and practical way to accelerate the commercialization of PSCs by developing a series of new donor copolymers for efficient and long-term stable thickness bulk heterojunction PSCs.
authors.affiliation: College of Chemistry, Nanchang University, 999 Xuefu Avenue, Nanchang, 330031, China.
authors.forename: Xunfan
authors.initials: X
authors.lastname: Liao
authors.affiliation: College of Chemistry, Nanchang University, 999 Xuefu Avenue, Nanchang, 330031, China.|Jiangxi Provincial Key Laboratory of New Energy Chemistry/Institute of Polymers, Nanchang University, 999 Xuefu Avenue, Nanchang, 330031, China.
authors.forename: Feiyan
authors.initials: F
authors.lastname: Wu
authors.affiliation: College of Chemistry, Nanchang University, 999 Xuefu Avenue, Nanchang, 330031, China.
authors.forename: Yongkang
authors.initials: Y
authors.lastname: An
authors.affiliation: College of Chemistry, Nanchang University, 999 Xuefu Avenue, Nanchang, 330031, China.
authors.forename: Qian
authors.initials: Q
authors.lastname: Xie
authors.affiliation: College of Chemistry, Nanchang University, 999 Xuefu Avenue, Nanchang, 330031, China.|Jiangxi Provincial Key Laboratory of New Energy Chemistry/Institute of Polymers, Nanchang University, 999 Xuefu Avenue, Nanchang, 330031, China.
authors.forename: Lie
authors.initials: L
authors.lastname: Chen
authors.affiliation: College of Chemistry, Nanchang University, 999 Xuefu Avenue, Nanchang, 330031, China.|Jiangxi Provincial Key Laboratory of New Energy Chemistry/Institute of Polymers, Nanchang University, 999 Xuefu Avenue, Nanchang, 330031, China.
authors.forename: Yiwang
authors.initials: Y
authors.lastname: Chen
mesh_terms: D011211:Electric Power Supplies; D055664:Electrochemical Techniques; D005464:Fluorobenzenes / Q000737:chemistry*; D015394:Molecular Structure; D011108:Polymers / Q000138:chemical synthesis / Q000737:chemistry*; D011789:Quantum Theory; D012993:Solar Energy; D013830:Thiadiazoles / Q000737:chemistry*
chemical_list: D005464:Fluorobenzenes; D011108:Polymers; D013830:Thiadiazoles
keywords: crystallinity; long-term stability; open-circuit voltage; planar copolymers; polymer solar cells