Affiliation:
1. Jiangxi Provincial Key Laboratory of Functional Molecular Materials Chemistry Faculty of Materials Metallurgy and Chemistry Jiangxi University of Science and Technology Ganzhou 341000 P. R. China
2. School of Energy & Power Engineering MOE Key Laboratory of Low‐Grade Energy Utilization Technologies and Systems CQU‐NUS Renewable Energy Materials & Devices Joint Laboratory Chongqing University Chongqing 400044 P. R. China
3. Department of Energy Engineering School of Energy and Chemical Engineering Perovtronics Research Center Low Dimensional Carbon Materials Center Ulsan National Institute of Science and Technology (UNIST) 50 UNIST‐gil, Ulju‐gun Ulsan 44919 South Korea
Abstract
AbstractTernary polymerization are demonstrated as a feasible and successful method of optimizing absorption, energy level, and crystallinity by maintaining the excellent properties of a polymer matrix. However, the third unit inevitably interrupts the periodic sequence distribution of the ordering packing of conjugated backbones, and thus balancing the trade‐off between the advantages of the third component and the disruption caused by the nonperiodic sequence distribution remains a great challenge. Herein, two terpolymer donors L1 and L2 are developed by introducing diethyl‐5,5′“‐dibromo‐4,4′”‐bis(2‐ethylhexyl)‐[2,2′:5′,2′'‐terthiophene]‐3′,4′‐dicarboxylate (DDT) unit as the third component. Owing to the electron‐deficient ability and S···O non‐covalent intramolecular interactions of DDT, terpolymers L1 and L2 displays deeper energy levels, enhanced molecular rigidity, and planarity than PM6. After blending with L8‐BO, the L1‐based polymer solar cells exhibit well miscibility with L8‐BO, leading to a more well‐defined nanofibrous morphology, face‐on orientation, and a slight energy loss in the blend films. As a result, the optimized L1:L8‐BO‐based device achieves a record power conversion efficiency (PCE) as high as 18.75%. This work provides a feasible strategy to develop high‐performance polymer donors via utilizing S···O non‐covalent intramolecular interactions to improve the planarity of polymer donors.
Funder
National Natural Science Foundation of China
Natural Science Foundation of Chongqing Municipality
Fundamental Research Funds for the Central Universities
Subject
Electrochemistry,Condensed Matter Physics,Biomaterials,Electronic, Optical and Magnetic Materials