Random Polymerization Strategy Leads to a Family of Donor Polymers Enabling Well‐Controlled Morphology and Multiple Cases of High‐Performance Organic Solar Cells

• DOI: 10.1002/adma.202003500
• Publication Date: 2020-11-13T16:57:35Z
• Authors: Jiaen Liang; Mingao Pan; Gaoda Chai; Zhengxing Peng; Jianquan Zhang; Siwei Luo; Qi Han; Yuzhong Chen; Ao Shang; Fujin Bai; Yuan Xu; Han Yu; Joshua Yuk Lin Lai; Qing Chen; Maojie Zhang; Harald Ade; He Yan
• Keywords: Donor polymers; Random polymerization strategy; 01 natural sciences; 7. Clean energy; Nonfullerene organic solar cells; 0104 chemical sciences

Abstract Developing high‐performance donor polymers is important for nonfullerene organic solar cells (NF‐OSCs), as state‐of‐the‐art acceptors can only perform well if they are coupled with a matching suitable energy levels. However, there very limited choices of NF‐OSCs, and the most commonly used ones named PM6 PM7, which suffer from several problems. First, performance these (particularly PM7) relies on precise control their molecular weights. Also, optimal morphology extremely sensitive to any structural modification. In this work, family developed based random polymerization strategy. These achieve well‐controlled variety chemical structures The polymer donors D–A1–D–A2‐type copolymers in D A1 units monomers originating or while A2 unit comprises an electron‐deficient core flanked by two thiophene rings branched alkyl chains. Consequently, multiple cases highly efficient NF‐OSCs achieved efficiencies between 16.0% 17.1%. As cores be changed many other units, strategy easily expand NF‐OSCs.