Non-equivalent D-A copolymerization strategy towards highly efficient polymer donor for polymer solar cells

• 作者: Ziya Shang Liuyang Zhou Chenkai Sun Lei Meng Wenbin Lai Jinyuan Zhang Wenchao Huang Yongfang Li
• 来源期刊: 中国科学：化学（英文版）
• 年，卷（期）: 2021,（6）
• 所属期刊栏目: ARTICLES
• 页码范围: 1031-1038
• 页数: 8页
• 语种: 英文

摘要

D-A copolymerization is a broadly utilized molecular design strategy to construct high efficiency photovoltaic materials for polymer solar cells (PSCs),and all the D-A copolymer donors reported till now are the alternate D-A copolyrners with equal D-and A-units.Here,we first propose a non-equivalent D-A copolymerization strategy with unequal D-and A-units,and develop three novel non-equivalent D-A copolymer donors (PM6-D 1,PM6-D2 and PM6-D3 with D/A unit ratio of 1.1:0.9,1.2:0.8 and 1.3:0.7,respectively) by inserting more D units into the alternate D-A copolymer PM6 backbone to finely tune the physico-chemical and photovoltaic properties of the polymers.The three non-equivalent D-A copolymers show the down-shifted highest occupied molecular orbital (HOMO) energy levels,higher hole mobility,higher degree of molecular self-assembly and higher molecular crystallinity with the increase of D-unit ratio in comparison with the alternate D-A copolymer PM6.As a result,all the three non-equivalent D-A copolymer-based PSCs with Y6 as acceptor achieve improved power conversion efficiency (PCE)with higher Voc,larger Jsc and higher FF simultaneously.Particularly,the PM6-D1 :Y6 based PSC achieved a high PCE of 17.71％,which is significantly higher than that (15.82％) of the PM6:Y6 based PSC and is one of the highest performances in the binary PSCs.