Oligomeric Acceptor: A “Two‐in‐One” Strategy to Bridge Small Molecules and Polymers for Stable Solar Devices

• Published in: Angewandte Chemie International Edition Vol. 61; no. 23; pp. e202201844 - n/a
• Main Authors: Wang, Hengtao, Cao, Congcong, Chen, Hui, Lai, Hanjian, Ke, Chunxian, Zhu, Yulin, Li, Heng, He, Feng
• Format: Journal Article
• Language: English
• Published: WEINHEIM Wiley 07.06.2022; Wiley Subscription Services, Inc
• Edition: International ed. in English
• Subjects: Chemistry; Chemistry, Multidisciplinary; Configurational Isomers; Energy conversion efficiency; Heterojunction devices; Oligomeric Acceptors; Oligomerization; Organic Solar Cells; Photovoltaic cells; Physical Sciences; Polymers; Science & Technology; Solar cells; Stability; Configurational Isomers; Oligomeric Acceptors; CELLS; VOLTAGE; Oligomerization; Stability; NON-FULLERENE ACCEPTOR; PERFORMANCE; Organic Solar Cells; ELECTRON-ACCEPTORS
• ISSN: 1433-7851; 1521-3773
• DOI: 10.1002/anie.202201844

Oligomeric acceptors are expected to combine the advantages of both highly developed small molecular and polymeric acceptors. However, organic solar cells (OSCs) based on oligomers lag far behind due to their slow development and low diversity. Here, three oligomeric acceptors were produced through oligomerization of small molecules. The dimer dBTICγ‐EH achieved the best power conversion efficiencies (PCEs) of 14.48 % in bulk heterojunction devices and possessed a T80 (80 % of the initial PCE) lifetime of 1020 h under illumination, which were far better than that of small molecular and polymeric acceptors. More excitingly, it showed PCEs of 16.06 % in quasi‐planar heterojunction (Q‐PHJ) devices which is the highest value OSCs using oligomeric acceptors to date. These results suggest that oligomerization of small molecules is a promising strategy to achieve OSCs with optimized performance between the high efficiency and durable stability, and offer oligomeric materials a bright future in commercial applications. Three oligomeric acceptors were synthesized in this work. Investigations revealed that oligomer acceptor‐based devices showed much better photovoltaic performance and light‐soaking stability than small molecules and polymers. dBTICγ‐EH, a dimer, showed a power conversion efficiency (PCE) of 16.06 % in Q‐PHJ devices with superior device stability, which is the highest value among the reported oligomeric acceptors to date.