TY - JOUR
T1 - Fluorine tuning of morphology, energy loss, and carrier dynamics in perylenediimide polymer solar cells
AU - Zhu, Weigang
AU - Alzola, Joaquin M.
AU - Aldrich, Thomas J.
AU - Kohlstedt, Kevin L.
AU - Zheng, Ding
AU - Hartnett, Patrick E.
AU - Eastham, Nicholas D.
AU - Huang, Wei
AU - Wang, Gang
AU - Young, Ryan M.
AU - Schatz, George C.
AU - Wasielewski, Michael R.
AU - Facchetti, Antonio
AU - Melkonyan, Ferdinand
AU - Marks, Tobin J.
N1 - Funding Information:
This research was supported in part by the Center for Light Energy Activated Redox Processes (LEAP), an Energy Frontier Research Center funded by the U.S. DOE, Office of Science, Office of Basic Energy Sciences under Award DE-SC0001059 (J.M.A., T.J.M., M.R.W., R.M.Y., synthesis, spectroscopy, K.L.K., G.C.S., theory), by the U.S. DOE, Office of Science, and Office of Basic Energy Sciences under Award Number DE-FG02-08ER46536 (J.M.A., materials synthesis), AFOSR Grant FA9550-18-1-0320 (A.F., W.Z., G.W., polymer design, characterization), and the NU MRSEC under NSF Grant DMR-1720139 (W.H., electronic structure determination). F.S.M. was supported by Award 70NANB14H012 from the U.S. Department of Commerce, National Institute of Standards and Technology as part of the Center for Hierarchical Materials Design (CHiMaD). T.J.A. thanks NSF for a graduate research fellowship. This work used the EPIC, BioCryo, Keck-II, and/or SPID facilities of NUANCE Center, supported by the Soft and Hybrid Nanotechnology Experimental (SHyNE) Resource (NSF ECCS-1542205), the International Institute for Nanotechnology (IIN), the State of Illinois, and the NSF MRI Program DMR-1229693. Use of the Advanced Photon Source, an Office of Science User Facility operated for the U.S. DOE Office of Science by Argonne National Lab, was supported by the U.S. DOE under Contract DE-AC02-06CH11357. We thank Profs. S. Fabiano and R. Bleher and Drs. X. Chen, Y. Li, E. W. Roth, and B. Wang for helpful discussions.
Publisher Copyright:
Copyright © 2019 American Chemical Society.
PY - 2019/11/8
Y1 - 2019/11/8
N2 - We investigate backbone fluorination effects in bulk-heterojunction (BHJ) polymer solar cells (PSCs) with the fluorine-poor PBDTT-FTTE and fluorine-rich PBDTTF-FTTE donor polymers, paired with the perylenediimide (PDI) 3D "propeller acceptor" Ph(PDI)3. The PBDTTF-FTTE:Ph(PDI)3 devices exhibit a >50% power conversion efficiency (PCE, up to 9.1%) increase versus PBDTT-FTTE:Ph(PDI)3. This enhancement reflects structurally optimized phase separation due to templating effects, affording reduced energy loss, higher electron mobility, greater free charge lifetimes and yields, and lower bimolecular recombination, as quantified by UPS, AFM, TEM, GIWAXS, SCLC, light intensity dependence measurements, and fs/ns transient absorption (TA) spectroscopy. In PBDTTF-FTTE, the DFT-computed dipole orientations of the ground and excitonic states are nearly antiparallel, explaining the longer free charge lifetimes, minimized recombination, and lowered exciton binding energy. The PBDTTF-FTTE:Ph(PDI)3 performance enhancement vs that of the fluorine-poor PBDTT-FTTE:Ph(PDI)3 analogue as well as the overall PSC performance exceeds that of the corresponding PC71BM- A nd ITIC-Th-based cells.
AB - We investigate backbone fluorination effects in bulk-heterojunction (BHJ) polymer solar cells (PSCs) with the fluorine-poor PBDTT-FTTE and fluorine-rich PBDTTF-FTTE donor polymers, paired with the perylenediimide (PDI) 3D "propeller acceptor" Ph(PDI)3. The PBDTTF-FTTE:Ph(PDI)3 devices exhibit a >50% power conversion efficiency (PCE, up to 9.1%) increase versus PBDTT-FTTE:Ph(PDI)3. This enhancement reflects structurally optimized phase separation due to templating effects, affording reduced energy loss, higher electron mobility, greater free charge lifetimes and yields, and lower bimolecular recombination, as quantified by UPS, AFM, TEM, GIWAXS, SCLC, light intensity dependence measurements, and fs/ns transient absorption (TA) spectroscopy. In PBDTTF-FTTE, the DFT-computed dipole orientations of the ground and excitonic states are nearly antiparallel, explaining the longer free charge lifetimes, minimized recombination, and lowered exciton binding energy. The PBDTTF-FTTE:Ph(PDI)3 performance enhancement vs that of the fluorine-poor PBDTT-FTTE:Ph(PDI)3 analogue as well as the overall PSC performance exceeds that of the corresponding PC71BM- A nd ITIC-Th-based cells.
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U2 - 10.1021/acsenergylett.9b02146
DO - 10.1021/acsenergylett.9b02146
M3 - Article
AN - SCOPUS:85074175243
SN - 2380-8195
VL - 4
SP - 2695
EP - 2702
JO - ACS Energy Letters
JF - ACS Energy Letters
IS - 11
ER -
