Ester-functionalized quinoxaline-based polymers for application in organic photovoltaics
Ester-functionalized quinoxaline-based polymers for application in organic photovoltaics
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DOI：
10.1016/j.matchemphys.2022.126225
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发表时间：
2022-05
影响因子：
4.6
通讯作者：
Tsubasa Mikie;Yuka Iwasaki;I. Osaka
中科院分区：
文献类型：
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作者：
Tsubasa Mikie;Yuka Iwasaki;I. Osaka
喹诺啉（Qx）是一种有趣的π共轭聚合物的构建单元，它允许我们通过选择取代基来轻松地控制电子性质。本研究合成了酯功能化Qx （QE）及其具有辛基（PTQE-C8）和2-乙基己基（PTQE-EH）的聚合物。由于酯基的吸电子性质，QE具有强烈的缺电子性质，因此聚合物具有相对较低的HOMO能级，约为−5.5 eV，光学带隙较小，小于1.6 eV。研究发现，ptqe - c8均比ptqe - ein（基于富勒烯（PC61BM）和非富勒烯（Y6））电池表现出更高的光伏性能，效率分别为5.8%和9.2%。我们将ptqe - c8比toptqe - eh8性能更高归因于共混膜中材料的结晶度更高。有趣的是，我们还发现这些聚合物具有n型材料的功能。这项工作表明，QE可以成为p型和n型聚合物的有趣构建单元。
Quinoxaline (Qx) is an interesting building unit for π-conjugated polymers as it allows us to easily control the electronic property by selecting the substituents. In this study, we synthesized ester-functionalized Qx (QE) and its polymers with octyl (PTQE-C8) and 2-ethylhexyl groups (PTQE-EH). Due to the electron-withdrawing property of the ester group, QE had strong electron-deficient nature and thereby the polymers had relatively low-lying HOMO energy levels of around −5.5 eV and relatively small optical bandgaps of narrower than 1.6 eV. It was found thatPTQE-C8consistently exhibited higher photovoltaic performance thanPTQE-EHin both cells based on fullerene (PC61BM) and non-fullerene (Y6), in which the efficiencies were 5.8% and 9.2%, respectively. We ascribed the higher performance ofPTQE-C8compared toPTQE-EHto the higher crystallinity of the materials in the blend films. Interestingly, we also found that the polymers functioned as n-type materials. This work demonstrates that QE can be an interesting building unit for both p-type and n-type polymers.