title: Effectively Improving Extinction Coefficient of Benzodithiophene and Benzodithiophenedione-based Photovoltaic Polymer by Grafting Alkylthio Functional Groups.
abstract: Alkylthio groups have received much attention in the polymer community for their molecular design applications in polymer solar cells. In this work, alkylthio substitution on the conjugated thiophene side chains in benzodithiophene (BDT) and benzodithiophenedione (BDD)-based photovoltaic polymer was used to improve the extinction coefficient. The introduction of alkylthio groups into the polymer increased its extinction coefficient while the HOMO levels, bandgaps, and absorption bands remained the same. Thus, the short circuit current density (Jsc) and the efficiency of the device were much better than those of the control device. Thus, introducing the alkylthio functional group in polymer is an effective method to tune the extinction coefficient of photovoltaic polymer. This provides a new path to improve photovoltaic performance without increasing active layer thickness, which will be very helpful to design advanced photovoltaic materials for high photovoltaic performance.
authors.affiliation: Department of Chemistry, School of Chemistry and Biology Engineering, University of Science and Technology Beijing, 30 Xueyuan Road, Beijing, 100083, China.|State Key Laboratory of Polymer Physics and Chemistry, Beijing National Laboratory for Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Zhongguancun North First Street 2, Beijing, 100190, China.
authors.forename: Qi
authors.initials: Q
authors.lastname: Wang
authors.affiliation: Department of Chemistry, School of Chemistry and Biology Engineering, University of Science and Technology Beijing, 30 Xueyuan Road, Beijing, 100083, China.|State Key Laboratory of Polymer Physics and Chemistry, Beijing National Laboratory for Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Zhongguancun North First Street 2, Beijing, 100190, China.
authors.forename: Shaoqing
authors.initials: S
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Polymer Physics and Chemistry, Beijing National Laboratory for Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Zhongguancun North First Street 2, Beijing, 100190, China. xubowei2004@iccas.ac.cn.
authors.forename: Bowei
authors.initials: B
authors.lastname: Xu
authors.affiliation: State Key Laboratory of Polymer Physics and Chemistry, Beijing National Laboratory for Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Zhongguancun North First Street 2, Beijing, 100190, China.
authors.forename: Long
authors.initials: L
authors.lastname: Ye
authors.affiliation: State Key Laboratory of Polymer Physics and Chemistry, Beijing National Laboratory for Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Zhongguancun North First Street 2, Beijing, 100190, China.
authors.forename: Huifeng
authors.initials: H
authors.lastname: Yao
authors.affiliation: Department of Chemistry, School of Chemistry and Biology Engineering, University of Science and Technology Beijing, 30 Xueyuan Road, Beijing, 100083, China.|State Key Laboratory of Polymer Physics and Chemistry, Beijing National Laboratory for Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Zhongguancun North First Street 2, Beijing, 100190, China.
authors.forename: Yong
authors.initials: Y
authors.lastname: Cui
authors.affiliation: State Key Laboratory of Polymer Physics and Chemistry, Beijing National Laboratory for Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Zhongguancun North First Street 2, Beijing, 100190, China.
authors.forename: Hao
authors.initials: H
authors.lastname: Zhang
authors.affiliation: Department of Chemistry, School of Chemistry and Biology Engineering, University of Science and Technology Beijing, 30 Xueyuan Road, Beijing, 100083, China. wenxiayuan20@aliyun.com.
authors.forename: Wenxia
authors.initials: W
authors.lastname: Yuan
authors.affiliation: Department of Chemistry, School of Chemistry and Biology Engineering, University of Science and Technology Beijing, 30 Xueyuan Road, Beijing, 100083, China. hjhzlz@iccas.ac.cn.|State Key Laboratory of Polymer Physics and Chemistry, Beijing National Laboratory for Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Zhongguancun North First Street 2, Beijing, 100190, China. hjhzlz@iccas.ac.cn.
authors.forename: Jianhui
authors.initials: J
authors.lastname: Hou
keywords: alkylthio group; extinction coefficients; polymers; solar cells; structure-activity relationships