@article{3c98ad0bffaa4b77a63b1da91d8ebc4c,
title = "Readily Accessible Benzo[d]thiazole Polymers for Nonfullerene Solar Cells with >16% Efficiency and Potential Pitfalls",
abstract = "Here we report facile, high-yield synthetic access to the difluoro BTA building block, 4,7-bis(5-bromo-4-(2-hexyl-decyl)-thiophen-2-yl)-5,6-difluoro-2-(pentadecan-7-yl)-benzo[d]thiazole (BTAT-2f), for use in donor (D)-acceptor 1 (A1)-D-acceptor 2 (A2) polymers [D = bithiophene; A1 = BTA-2f; A2 = benzothiadiazole (BT) derivative] for organic solar cells (OSCs). Fine tuning of polymer optical and electronic properties is achieved by incrementally varying the A2 fluorination level. Bulk-heterojunction (BHJ) PBTATBT-4f:Y6 solar cells deliver a noteworthy power conversion (PCE) efficiency of 16.08% (Voc = 0.81 V; Jsc = 27.25 mAcm-2 FF = 72.70%) without processing additives. In contrast, PBTATBT-2f:Y6 exhibits an irregular morphology and low PCE, ascribable to cocrystal formation-induced recombination, which is unprecedented for nonfullerene (NFA) OSCs. This result should be of guiding significance for future NFA design.",
author = "Feng, {Liang Wen} and Jianhua Chen and Subhrangsu Mukherjee and Sangwan, {Vinod K.} and Wei Huang and Yao Chen and Ding Zheng and Strzalka, {Joseph W.} and Gang Wang and Hersam, {Mark C.} and Hersam, {Mark C.} and Hersam, {Mark C.} and Dean Delongchamp and Antonio Facchetti and Marks, {Tobin J.} and Marks, {Tobin J.}",
note = "Funding Information: This work was supported by Center for Light Energy Activated Redox Processes (LEAP), an Energy Frontier Research Center funded by the U.S. Department of Energy, Office of Science, Basic Energy Sciences under Award No. DE-SC0001059; by AFOSR grant FA9550-18-1-0320, U.S. Department of Commerce, National Institute of Standards and Technology as part of the Center for Hierarchical Materials Design (CHiMaD) award 70NANB19H005; and Flexterra Inc. L.-W.F. thanks Shanghai Institute of Organic Chemistry and Jiangsu Aosaikang Pharmaceutical Co., Ltd. for a postdoctoral fellowship. J.C. thanks the National Natural Science Foundation of China (61804073). Portions of this research were carried out at the 7-ID Spectroscopy Soft and Tender (SST-1) beamline of the National Synchrotron Light Source II, a U.S. Department of Energy (DOE) Office of Science User Facility operated for the DOE Office of Science by Brookhaven National Lab. under Contract No. DE-SC0012704, at beamline 11.0.1.2 of the Advanced Light Source, which is supported by the Director, Office of Science, Office of Basic Energy Sciences, of the U.S. Department of Energy under contract no. DE-AC02-05CH11231, and at beamline 8-ID-E of the Advanced Photon Source, a U.S. Department of Energy (DOE) Office of Science User Facility operated for the DOE Office of Science by Argonne National Laboratory under Contract No. DE-AC02-06CH11357. D. Fischer, C. Jaye, E. Gann (NSLS-II), and C. Wang (ALS) are acknowledged for assisting with the experiments. Certain commercial equipment, instruments, materials, and software are identified in this paper in order to specify the experimental procedure adequately. Such identification does not imply recommendation or endorsement by the National Institute of Standards and Technology, nor is it intended to imply that the materials or equipment identified are necessarily the best available for the purpose. This work (impedance spectroscopy) made use of the MatCl Facility which receives support from the MRSEC Program (NSF DMR-1720139) of the Materials Research Center at Northwestern University. Publisher Copyright: {\textcopyright} 2020 American Chemical Society.",
year = "2020",
month = jun,
day = "12",
doi = "10.1021/acsenergylett.0c00691",
language = "English (US)",
volume = "5",
pages = "1780--1787",
journal = "ACS Energy Letters",
issn = "2380-8195",
publisher = "American Chemical Society",
number = "6",
}
