Wide Bandgap Conjugated Polymers Based on Difluorobenzoxadiazole for Efficient Non‐Fullerene Organic Solar Cells. Issue 22 (22nd August 2022)

• Record Type: Journal Article
• Authors: Pan, Langheng; Zhan, Tao; Zhang, Yue; Li, Junyu; Wu, Yifan; He, Zhicai; Cai, Ping; Duan, Chunhui; Huang, Fei; Cao, Yong
• Other Names: Zhang Xin guestEditor.; Huang Hui guestEditor.
• Is Part Of: Macromolecular rapid communications. Volume 43:Issue 22(2022)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2022-08-22
• Subjects: difluorobenzoxadiazole -- non‐fullerene -- organic solar cells -- polymer donors -- wide bandgap; Macromolecules -- Periodicals; Polymers -- Periodicals; Chemistry -- Periodicals; 547.705
• DOI: 10.1002/marc.202200591
• Languages: English
• ISSNs: 1022-1336

Abstract

Abstract: Wide bandgap polymers with a donor–acceptor alternating structure play a key role in constructing high‐efficiency organic solar cells (OSCs). However, only a handful of high‐performance polymers are available owing to the limited choices of acceptor units. 5, 6‐Difluorobenzo[ c ][1, 2, 5]oxadiazole (ffBX) is a promising acceptor unit with high ionization potential, and can afford high charge carrier mobility and strong aggregation for the resulting polymers. Historically, ffBX is successfully used in constructing high‐performance polymer donors for fullerene‐based OSCs. However, this unit is far less been explored in non‐fullerene OSCs. In this work, three ffBX‐based wide bandgap polymers (Oc00, Oc25, and Oc50) with varied solubilizing side chain content for application in non‐fullerene OSCs are reported. The polymers show matched energy levels and complementary optical absorption with the state‐of‐the‐art non‐fullerene acceptor Y6. Moreover, the polymer solubility, solid state packing, and bulk‐heterojunction morphology are finely tuned via side chain engineering. Encouragingly, a decent efficiency of 14.25% is realized by the polymer Oc25 when blended with Y6 due to the efficient charge transport and favorable active layer morphology. These results suggest the promising prospect of ffBX in constructing high‐performance polymer donors for non‐fullerene OSCs. Abstract : Three polymers, Oc00, Oc25, and Oc50, based on difluorobenzoxadiazole (ffBX) with varied alkyl chain contents are synthesized for use as electron donors in non‐fullerene organic solar cells (OSCs). Oc25 offers the highest power conversion efficiency of 14.25%, which is the highest value for ffBX‐based polymers in OSCs, suggesting the tremendous potential of ffBX unit in designing high‐performance photovoltaic polymers.