Effect of Bulky Atom Substitution on Backbone Coplanarity and Electrical Properties of Cyclopentadithiophene-Based Semiconducting Polymers
- 주제(키워드) chlorination , fluorination , organic field-effect transistors , semiconducting polymers , steric hindrance
- 관리정보기술 faculty
- 등재 SCIE, SCOPUS
- 발행기관 John Wiley and Sons Inc
- 발행년도 2022
- URI http://www.dcollection.net/handler/ewha/000000191107
- 본문언어 영어
- Published As https://doi.org/10.1002/marc.202100709
초록/요약
The effect of atomic substitution on the optoelectronic properties of a coplanar donor–acceptor (D–A) semiconducting polymer (SPs), prepared using cyclopentadithiophene (CDT) and 2,1,3-benzothiadiazole (BT) moieties, is investigated. By substituting a carbon atom in the BT unit with C-F or C–Cl, two random D–A SPs are prepared, and their optoelectronic properties are thoroughly investigated. Density functional theory calculations demonstrate that the fluorinated polymer has a slightly smaller dihedral angle (ϴ = 0.6°) than the pristine polymer (ϴ = 1.9°) in its lowest-energy conformation, implying efficient charge transport through the coplanar backbone of the fluorinated polymer. However, the chlorinated polymer shows the lowest energy at a relatively larger dihedral angle (ϴ = 139°) due to the steric hindrance induced by bulky chlorine atoms in the backbone, thereby leading to thin-film morphology, which is unfavorable for charge transport. Consequently, the fluorinated polymer yields the highest field-effect mobility (μ) of 0.57 cm2 V−1 s−1, slightly higher than that of the pristine polymer (μ = 0.33 cm2 V−1 s−1), and the extended device lifetime of organic field-effect transistors over 12 d without any encapsulation layers. The results of this study provide design guidelines for air-stable D–A SPs. © 2021 Wiley-VCH GmbH
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