Near-Infrared Acceptors with Imide-Containing End Groups for Organic Solar Cells
Shiling Shi, Shimin Zhang, Zhongyuan Xue, Xiang Yao, Guangcong Zhang, Jiaxing Gao, Yanru Li, Xueyang Tu, Shengnan Zhang, Chan Zhang, Zhongwei Liu, Zheng Tang, Hongliang Zhong, Weiwei Li, Zhuping Fei
Abstract
-inden-1-ylidene)malononitrile (IC) end groups, which can be modified by but limited to phenyl, thienyl, and naphthyl units with halogenated, methyl, and methyloxy substitution. In this work, we employed an imide-containing unit to construct a new IC end group, based on which a series of new electron acceptors were synthesized. The strong electron-deficient nature of imide units enables the new acceptors to show efficient intramolecular charge transfer and hence red-shifted absorption spectra compared to their IC counterparts. These new electron acceptors were applied to OSCs, providing efficiencies of over 17% with a low voltage loss of 0.52 eV. These results demonstrate that the new imide-containing end groups are promising fragments for the construction of near-infrared electron acceptors for high-performance OSCs.