Linker Unit Modulation of Polymer Acceptors Enables Highly Efficient Air‐Processed All‐Polymer Solar Cells. Issue 25 (10th July 2022)

• Record Type: Journal Article
• Authors: Kim, Ha Kyung; Yu, Han; Pan, Mingao; Shi, Xiaoyu; Zhao, Heng; Qi, Zhenyu; Liu, Wei; Ma, Wei; Yan, He; Chen, Shangshang
• Is Part Of: Advanced science. Volume 9:Issue 25(2022)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2022-07-10
• Subjects: air‐processed -- all‐polymer solar cells -- linker units -- polymer acceptors -- power conversion efficiencies; Science -- Periodicals; 505
• DOI: 10.1002/advs.202202223
• Languages: English
• ISSNs: 2198-3844

Abstract

Abstract: A group of regioregular polymer acceptors is synthesized by polymerizing Y6 moieties with different linker units including thiophene, vinylene, 2, 2'‐bithiophene, and thieno[3, 2‐b]thiophene, and their optoelectrical properties and photovoltaic performances are studied systematically. It is found that the linker units have significant impacts on the backbone planarity, conjugation, and hence optoelectrical properties of polymer acceptors. The vinylene‐based PYF‐V‐ o polymer shows a smaller dihedral angle between the end groups and vinylene units and a more rigid polymer backbone, thus affording bathochromic absorption and better electron‐transporting capacity. As a result, the PM6:PYF‐V‐ o based all‐polymer solar cells (all‐PSCs) are able to achieve the highest power conversion efficiency of 16.4% with an unprecedented small voltage loss of 0.49 V. Moreover, the PM6:PYF‐V‐ o blend exhibits good resistance to environmental stressors and the air‐processed PM6:PYF‐V‐ o cells can still maintain a high efficiency of 16.1%, which is the best air‐processed all‐PSC efficiency reported to date. This study provides the structural‐property guidance that can be used to facilitate the development of polymer acceptors for all‐PSCs. Abstract : The effects of linker units on polymer acceptor properties and device performance are studied, and it shows the linker units have significant impacts on the optoelectrical properties by impacting polymer rigidity and conjugation. The vinylene‐based PYF‐V‐ o polymer acceptor exhibits a more planar polymer backbone, and its all‐polymer solar cells realize the highest power conversion efficiency of 16.4% and 16.1% when processed in N2 and air atmosphere, respectively.