Influence of the alkyl substitution position on photovoltaic properties of 2D-BDT-based conjugated polymers  

烷基链取代位置对二维苯并二噻吩类共轭聚合物光伏特性的影响（英文）

作　　者：姚惠峰 叶龙 樊本虎 霍利军 侯剑辉 

机构地区：[1]State Key Laboratory of Polymer Physics and Chemistry,Beijing National Laboratory for Molecular Sciences,Institute of Chemistry,Chinese Academy of Sciences

出　　处：《Science China Materials》2015年第3期213-222,共10页中国科学（材料科学（英文版）

基　　金：supported by the National Basic Research Program(2014CB643500);the National Natural Science Foundation of China(91333204 and 51261160496);the Chinese Academy of Sciences(XDB12030200 and KJZDEW-J01)

摘　　要：Three conjugated polymers based on thienyl-substituted benzodithiophene(BDT) and 4,7-bis-thienyl-benzothiadiazole(DTBT) with varied substitution positions of the alkyl side chains were synthesized to investigate the correlations between the structure and photovoltaic performance of the polymer photovoltaic materials.The three polymers named PBDTDTBT-p,PBDTDTBT-o and PBDTDTBT-m were characterized by a set of methods including absorption spectroscopy,cyclic voltammetry,thermogravimetric analysis,X-ray diffraction,density functional theory and photovoltaic measurements.The results show that the steric hindrance caused by the different substitution positions of the alky chains has a significant influence on the photovoltaic properties of the polymers.The open-circuit voltage(Voc) of the photovoltaic devices based on the three polymers could range from 0.67 to 0.90 V.Clearly,this finding provides us a feasible strategy to optimize the photovoltaic properties by simply changing the positions of the alkyl chains.本文将具有不同取代位点的二维共轭支链引入到PBDTDTBT类聚合物的苯并二噻吩单元上,设计和合成了三种骨架相同的二维共轭聚合物,即PBDTDTBT-p,PBDTDTBT-o和PBDTDTBT-m,并在此基础上探究了烷基链取代位点对共轭聚合物的光伏性质以及器件性能的影响.通过吸收光谱、循环伏安、热失重分析、X射线衍射、光伏测试以及理论计算等手段对比研究了三种聚合物光伏材料,结果表明由不同烷基链取代位点引起的分子空间位阻作用对三种聚合物的光物理性质、微观形貌以及光伏性能有着重要的影响.基于三种聚合物制备的光伏器件的开路电压可从0.67 V变化到0.90 V,其光伏效率也相应地从3.48%提高到5%以上.调节烷基链取代位点是一种简单有效制备高性能聚合物光伏材料的优化策略.

关 键 词：苯并二噻吩 共轭聚合物 BDT 烷基链 光伏材料 二维 PPM 

分 类 号：TQ317[化学工程—高聚物工业]