Isomers of Dithienocyclopentapyrene-Based Non-Fullerene Electron Acceptors: Configuration Effect on Photoelectronic Properties |
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| Authors: | Jianglin Wu Dr Yao Chen Bin Hu Zhenguo Pang Prof Zhiyun Lu Prof Yan Huang |
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| Institution: | 1. Key Laboratory of Green Chemistry and Technology, (Ministry of Education), College of Chemistry, Sichuan University, Chengdu, 610064 P.R. China
These authors contributed equally to this work.;2. Key Laboratory of Green Chemistry and Technology, (Ministry of Education), College of Chemistry, Sichuan University, Chengdu, 610064 P.R. China |
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| Abstract: | One pair of isomers, centrosymmetric anti- Py - 1 and axisymmetric syn- Py - 2 , was designed and synthesized with an acceptor–donor–acceptor (A–D–A) structure by choosing dithienocyclopentapyrene with four 4-hexylphenyl side chains as the D unit, and 2-(5,6-difluoro-3-oxo-2,3-dihydro-1H-inden-1-ylidene) malononitrile as the A unit. In-depth structure–property relationship studies revealed that the isomers have similar UV/Vis absorption, fluorescence emission, and energy levels but significant differences in molecular shape, polarity, and charge mobility. Solution-processed bulk-heterojunction (BHJ) small-molecule organic solar cells with Py - 1 as the electron-acceptor material and PTB7-Th as the electron-donor material exhibit a power conversion efficiency (PCE) of 6.07 %, or 60 % higher than that of Py - 2 (3.7 %), which could be mainly attributed to the higher and more balanced hole/electron mobilities and better phase separation of the Py - 1 -based active layer. |
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| Keywords: | donor–acceptor systems fused-ring systems isomerization organic solar cells structure–property relationships |
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