@article {28573,
	title = {Regio-Regular Polymer Acceptors Enabled by Determined Fluorination on End Groups for All-Polymer Solar Cells with 15.2\&thinsp;\% Efficiency},
	journal = {Angew. Chem. Int. Ed.},
	volume = {60},
	number = {18},
	year = {2021},
	month = {2021/04/26},
	pages = {10137-10146},
	publisher = {John Wiley \&amp;amp;amp;amp;amp; Sons, Ltd},
	type = {https://doi.org/10.1002/anie.202016284},
	abstract = {Abstract Polymerization sites of small molecule acceptors (SMAs) play vital roles in determining device performance of all-polymer solar cells (all-PSCs). Different from our recent work about fluoro- and bromo- co-modified end group of IC-FBr (a mixture of IC-FBr1 and IC-FBr2), in this paper, we synthesized and purified two regiospecific fluoro- and bromo- substituted end groups (IC-FBr-o \&amp; IC-FBr-m), which were then employed to construct two regio-regular polymer acceptors named PYF-T-o and PYF-T-m, respectively. In comparison with its isomeric counterparts named PYF-T-m with different conjugated coupling sites, PYF-T-o exhibits stronger and bathochromic absorption to achieve better photon harvesting. Meanwhile, PYF-T-o adopts more ordered inter-chain packing and suitable phase separation after blending with the donor polymer PM6, which resulted in suppressed charge recombination and efficient charge transport. Strikingly, we observed a dramatic performance difference between the two isomeric polymer acceptors PYF-T-o and PYF-T-m. While devices based on PM6:PYF-T-o can yield power conversion efficiency (PCE) of 15.2?\%, devices based on PM6:PYF-T-m only show poor efficiencies of 1.4?\%. This work demonstrates the success of configuration-unique fluorinated end groups in designing high-performance regular polymer acceptors, which provides guidelines towards developing all-PSCs with better efficiencies.},
	keywords = {all-polymer solar cells, fluorinated end group, isomeric effect, Organic solar cells, polymer acceptors},
	isbn = {1433-7851},
	url = {https://doi.org/10.1002/anie.202016284},
	author = {Yu, Han and Pan, Mingao and Rui Sun and Agunawela, Indunil and Zhang, Jianquan* and Li, Yuhao and Qi, Zhenyu and Han, Han and Zou, Xinhui and Zhou, Wentao and Chen, Shangshang and Lai, Joshua Yuk Lin and Luo, Siwei and Luo, Zhenghui* and <strong>Zhao, Dahui</strong> and Lu, Xinhui and Ade, Harald and Huang, Fei and Min, Jie* and Yan, He*}
}
