TY - JOUR
T1 - Photovoltaic Blend Microstructure for High Efficiency Post-Fullerene Solar Cells. To Tilt or Not to Tilt?
AU - Wang, Gang
AU - Swick, Steven M.
AU - Matta, Micaela
AU - Mukherjee, Subhrangsu
AU - Strzalka, Joseph W.
AU - Logsdon, Jenna Leigh
AU - Fabiano, Simone
AU - Huang, Wei
AU - Aldrich, Thomas J.
AU - Yang, Tony
AU - Timalsina, Amod
AU - Powers-Riggs, Natalia
AU - Alzola, Joaquin M.
AU - Young, Ryan M.
AU - DeLongchamp, Dean M.
AU - Wasielewski, Michael R.
AU - Kohlstedt, Kevin L.
AU - Schatz, George C.
AU - Melkonyan, Ferdinand
AU - Facchetti, Antonio
AU - Marks, Tobin J.
N1 - Funding Information:
Photovoltaic device fabrications and evaluations, spectroscopy, and MD simulations were supported by the Center for Light Energy Activated Redox Processes (LEAP) and Energy Frontier Research Center funded by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Award DE-SC0001059 (G.W., M.M., J.L.L., W.H., T.J.A., N.P.-R., J.A., R.M.Y., M.R.W., K.L.K., G.C.S., T.J.M.). Synthesis, SCLC device fabrications and evaluations, and RSoXS were supported by Award 70NANB14H012 from U.S. Department of Commerce, National Institute of Standards and Technology as part of the Center for Hierarchical Materials Design (CHiMaD) (G.W., S.M.S., S.M., D.M.D., F.S.M., T.J.M.). Use of the Advanced Photon Source, an Office of Science User Facility operated for the U.S. Department of Energy (DOE) Office of Science by Argonne National Laboratory, was supported by the U.S. DOE under Contract DE-AC02-06CH11357 (J.W.S., G.W.). R-SoXS data were acquired at beamline 11.0.1.2 at 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 DE-AC02-05CH11231. A. L. D. Kilcoyne and C. Wang of the ALS (DOE) are acknowledged for assisting with the experimental setup and providing instrument maintenance. NEXAFS data were taken on the Soft X-ray Spectroscopy beamline at the Australian Synchrotron, part of ANSTO. This work made use of the EPIC, Keck-II, and/or SPID facilities of Northwestern University's NUANCE Center, which received support from the Soft and Hybrid Nanotechnology Experimental (SHyNE) Resource (NSF NNCI-1542205); the MRSEC program (NSF DMR-1121262) at the Materials Research Center; the International Institute for Nanotechnology (IIN), the Keck Foundation, and the State of Illinois. S.M.S. and T.J.A. thank the NSF for a Predoctoral Fellowship. S.F. thanks VINNOVA (2015-04859) and the Swedish Research Council (2016-03979) for financial support.
Funding Information:
Photovoltaic device fabrications and evaluations, spectroscopy, and MD simulations were supported by the Center for Light Energy Activated Redox Processes (LEAP) and Energy Frontier Research Center funded by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Award DE-SC0001059 (G.W., M.M., J.L.L., W.H., T.J.A., N.P.-R., J.A., R.M.Y., M.R.W., K.L.K., G.C.S., T.J.M.). Synthesis, SCLC device fabrications and evaluations, and R-SoXS were supported by Award 70NANB14H012 from U.S. Department of Commerce, National Institute of Standards and Technology as part of the Center for Hierarchical Materials Design (CHiMaD) (G.W., S.M.S., S.M., D.M.D., F.S.M., T.J.M.). Use of the Advanced Photon Source, an Office of Science User Facility operated for the U.S. Department of Energy (DOE) Office of Science by Argonne National Laboratory, was supported by the U.S. DOE under Contract DE-AC02-06CH11357 (J.W.S., G.W.). R-SoXS data were acquired at beamline 11.0.1.2 at 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 DE-AC02-05CH11231. A. L. D. Kilcoyne and C. Wang of the ALS (DOE) are acknowledged for assisting with the experimental setup and providing instrument maintenance. NEXAFS data were taken on the Soft X-ray Spectroscopy beamline at the Australian Synchrotron, part of ANSTO. This work made use of the EPIC, Keck-II, and/or SPID facilities of Northwestern University’s NUANCE Center, which received support from the Soft and Hybrid Nanotechnology Experimental (SHyNE) Resource (NSF NNCI-1542205); the MRSEC program (NSF DMR-1121262) at the Materials Research Center; the International Institute for Nanotechnology (IIN), the Keck Foundation, and the State of Illinois. S.M.S. and T.J.A. thank the NSF for a Predoctoral Fellowship. S.F. thanks VINNOVA (2015-04859) and the Swedish Research Council (2016-03979) for financial support.
Publisher Copyright:
© 2019 American Chemical Society.
PY - 2019/8/28
Y1 - 2019/8/28
N2 - Achieving efficient polymer solar cells (PSCs) requires a structurally optimal donor-acceptor heterojunction morphology. Here we report the combined experimental and theoretical characterization of a benzodithiophene-benzothiadiazole donor polymer series (PBTZF4-R; R = alkyl substituent) blended with the non-fullerene acceptor ITIC-Th and analyze the effects of substituent dimensions on blend morphology, charge transport, carrier dynamics, and PSC metrics. Varying substituent dimensions has a pronounced effect on the blend morphology with a direct link between domain purity, to some extent domain dimensions, and charge generation and collection. The polymer with the smallest alkyl substituent yields the highest PSC power conversion efficiency (PCE, 11%), reflecting relatively small, high-purity domains and possibly benefiting from "matched" donor polymer-small molecule acceptor orientations. The distinctive morphologies arising from the substituents are investigated using molecular dynamics (MD) simulations which reveal that substituent dimensions dictate a well-defined set of polymer conformations, in turn driving chain aggregation and, ultimately, the various film morphologies and mixing with acceptor small molecules. A straightforward energetic parameter explains the experimental polymer domain morphological trends, hence PCE, and suggests strategies for substituent selection to optimize PSC materials morphologies.
AB - Achieving efficient polymer solar cells (PSCs) requires a structurally optimal donor-acceptor heterojunction morphology. Here we report the combined experimental and theoretical characterization of a benzodithiophene-benzothiadiazole donor polymer series (PBTZF4-R; R = alkyl substituent) blended with the non-fullerene acceptor ITIC-Th and analyze the effects of substituent dimensions on blend morphology, charge transport, carrier dynamics, and PSC metrics. Varying substituent dimensions has a pronounced effect on the blend morphology with a direct link between domain purity, to some extent domain dimensions, and charge generation and collection. The polymer with the smallest alkyl substituent yields the highest PSC power conversion efficiency (PCE, 11%), reflecting relatively small, high-purity domains and possibly benefiting from "matched" donor polymer-small molecule acceptor orientations. The distinctive morphologies arising from the substituents are investigated using molecular dynamics (MD) simulations which reveal that substituent dimensions dictate a well-defined set of polymer conformations, in turn driving chain aggregation and, ultimately, the various film morphologies and mixing with acceptor small molecules. A straightforward energetic parameter explains the experimental polymer domain morphological trends, hence PCE, and suggests strategies for substituent selection to optimize PSC materials morphologies.
UR - http://www.scopus.com/inward/record.url?scp=85071639432&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85071639432&partnerID=8YFLogxK
U2 - 10.1021/jacs.9b03770
DO - 10.1021/jacs.9b03770
M3 - Article
C2 - 31379156
AN - SCOPUS:85071639432
VL - 141
SP - 13410
EP - 13420
JO - Journal of the American Chemical Society
JF - Journal of the American Chemical Society
SN - 0002-7863
IS - 34
ER -
