A-DA′D-A-Type Pentacyclic Fused-Ring Electron Acceptors for Efficient Organic Solar Cells

作者：Wang, Zhiqiang; Wei, Wenkui; Zeng, Liang; Liu, Tao; Yuan, Xiyue; Zhou, Jiadong; Yin, Bingyan; Li, Junyu; Xie, Zengqi; Huang, Fei; Cao, Yong; Duan, Chunhui^*

来源：Chemistry of Materials, 2023, 35(17): 6932-6942.

DOI：10.1021/acs.chemmater.3c01216

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Although superior power conversion efficiencies (PCEs)(>19%) havebeen achieved by organic solar cells (OSCs), high materials cost severelyprevents this photovoltaic technology from laboratory to industrialmaturity. Particularly, the prevailing A-DA & PRIME;D-A-typeheptacyclic fused-ring electron acceptors (FREAs) suffered from arduoussynthesis and extremely low overall synthetic yield. Herein, we reportthree A-DA & PRIME;D-A-type pentacyclic FREAs (BTPT4F-EH,BTPT4F-BO, and BTPT4F-HD) with varied side chain length for applicationin OSCs. Compared with the prevailing heptacyclic FREAs, the pentacyclicFREAs exhibited much lower synthetic complexity. Single-crystal analysisunraveled that stair-like two-dimensional molecular stacking modewas formed in the crystal of BTPT4F-BO due to the existence of strong & pi;-& pi; interactions and hydrogen bonds, which couldguarantee efficient charge transport in A-DA & PRIME;D-A-typepentacyclic FREAs. As a result, a remarkable PCE of 15.0% has beenoffered by the OSC based on BTPT4F-BO. The high PCE and low syntheticcomplexity further contributed to an unprecedented figure of merit(FOM = 0.36) for BTPT4F-BO. This work suggests, with respect to heptacyclicFREAs, A-DA & PRIME;D-A-type pentacyclic FREAs are morecompetitive candidates for the future industrial manufacturing ofOSCs.