Effect of Alkylsilyl Side-Chain Structure on Photovoltaic Properties of Conjugated Polymer Donors
Effect of Alkylsilyl Side-Chain Structure on Photovoltaic Properties of Conjugated Polymer Donors
复制标题
烷基甲硅烷基侧链结构对共轭聚合物供体光伏性能的影响
DOI：
10.1002/aenm.201702324
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发表时间：
2018-03-15
影响因子：
27.8
通讯作者：
Li, Yongfang
中科院分区：
文献类型：
--
作者：
Bin, Haijun;Yang, Yankang;Li, Yongfang
侧链工程是优化有机光伏材料光伏性能的一种重要策略。在这项工作中，通过在高效聚合物给体J71的基础上改变聚合物烷基硅烷基侧链的烷基取代基，合成了四种新的聚合物J70、J72、J73和J74，研究了烷基硅烷基侧链结构对中等带隙共轭聚合物给体光伏性能的影响。并且通过制备以这些聚合物为给体、以n型有机半导体（n - OS）m - ITIC为受体的聚合物太阳能电池（PSCs），研究了这五种聚合物的光伏性能。研究发现，较短且为线性的烷基硅烷基侧链能够提供有序的分子堆积、更强的吸收系数以及更高的电荷载流子迁移率，从而使相应的聚合物太阳能电池具有更高的短路电流密度（J(sc)）和填充因子值。而在三烷基硅烷基中具有较长或支化烷基取代基的聚合物显示出更低的最高已占分子轨道能级，这导致聚合物太阳能电池具有更高的开路电压（V - oc）。基于J70:m - ITIC和J71:m - ITIC的聚合物太阳能电池分别实现了11.62%和12.05%的功率转换效率（PCE），这在迄今为止文献报道的聚合物太阳能电池中处于较高水平。
Side-chain engineering is an important strategy for optimizing photovoltaic properties of organic photovoltaic materials. In this work, the effect of alkylsilyl side-chain structure on the photovoltaic properties of medium bandgap conjugated polymer donors is studied by synthesizing four new polymers J70, J72, J73, and J74 on the basis of highly efficient polymer donor J71 by changing alkyl substituents of the alkylsilyl side chains of the polymers. And the photovoltaic properties of the five polymers are studied by fabricating polymer solar cells (PSCs) with the polymers as donor and an n-type organic semiconductor (n-OS) m-ITIC as acceptor. It is found that the shorter and linear alkylsilyl side chain could afford ordered molecular packing, stronger absorption coefficient, higher charge carrier mobility, thus results in higher J(sc) and fill factor values in the corresponding PSCs. While the polymers with longer or branched alkyl substituents in the trialkylsilyl group show lower-lying highest occupied molecular orbital energy levels which leads to higher V-oc of the PSCs. The PSCs based on J70:m-ITIC and J71:m-ITIC achieve power conversion efficiency (PCE) of 11.62 and 12.05%, respectively, which are among the top values of the PSCs reported in the literatures so far.