New Polymerized Small Molecular Acceptors with Non‐Aromatic π‐Conjugated Linkers for Efficient All‐Polymer Solar Cells
Zhe Zhang, Zhixiang Li, Peiran Wang, Hongbin Chen, Kangqiao Ma, Yunxin Zhang, Tainan Duan, Chenxi Li, Zhaoyang Yao, Bin Kan, Xiangjian Wan, Yongsheng Chen
Abstract
Abstract Developing new polymerized small molecular acceptor (PSMA) is pivotal for improving the performance of all‐polymer solar cells. On the basis of this newly developed CH‐series small molecule acceptors, two PSMAs are reported herein (namely PZC16 and PZC17, respectively). To reduce the molecular torsion caused by the traditional aromatic π‐bridges, non‐aromatic conjugated units (ethynyl for PZC16 and vinylene for PZC17) are adopted as the linkers and their effect on the photo‐physical properties as well as the device performance are systematically investigated. Both polymer acceptors exhibit co‐planar molecular conformation, along with broad absorption ranges and suitable energy levels. In comparison with the PM6:PZC16 film, the PM6:PZC17 film exhibits more uniform phase separation in morphology with a distinct bi‐continuous network and better crystallinity. The PM6:PZC17‐binary‐based devices exhibit a satisfactory PCE of 16.33%, significantly higher than 9.22% of the PZC16‐based devices. Impressively, PM6:PZC17‐based large area device (ca. 1 cm 2 ) achieves an excellent PCE of 15.14%, which is among the top performance for reported all‐polymer solar cells (all‐PSCs).