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Title: Photovoltaic Blend Microstructure for High Efficiency Post-Fullerene Solar Cells. To Tilt or Not To Tilt?

Abstract

Achieving efficient polymer solar cells (PSCs) requires a structurally optimal donor-acceptor heterojunction morphology. In this paper, 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 analyse 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) computation which reveals 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. Finally, a straightforward energetic parameter explains the experimental polymer domain morphological trends, hence PCE, and suggests strategies for substituent selection to optimize PSC materials morphologies.

Authors:
 [1];  [1]; ORCiD logo [1]; ORCiD logo [2];  [3];  [1];  [4]; ORCiD logo [1]; ORCiD logo [1];  [1];  [1];  [1];  [1]; ORCiD logo [1];  [2]; ORCiD logo [1]; ORCiD logo [1]; ORCiD logo [1]; ORCiD logo [1]; ORCiD logo [5] more »; ORCiD logo [1] « less
  1. Northwestern Univ., Evanston, IL (United States)
  2. National Inst. of Standards and Technology (NIST), Gaithersburg, MD (United States)
  3. Argonne National Lab. (ANL), Argonne, IL (United States)
  4. Linköping Univ., Norrköping (Sweden)
  5. Northwestern Univ., Evanston, IL (United States); Flexterra Corporation, Skokie, IL (United States)
Publication Date:
Research Org.:
Energy Frontier Research Centers (EFRC) (United States). Center for Light Energy Activated Redox Processes (LEAP); Argonne National Lab. (ANL), Argonne, IL (United States)
Sponsoring Org.:
USDOE Office of Science (SC), Basic Energy Sciences (BES)
OSTI Identifier:
1560046
Grant/Contract Number:  
AC02-06CH11357; AC02-05CH11231; SC0001059
Resource Type:
Accepted Manuscript
Journal Name:
Journal of the American Chemical Society
Additional Journal Information:
Journal Volume: 141; Journal Issue: 34; Journal ID: ISSN 0002-7863
Publisher:
American Chemical Society (ACS)
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY; domain purity; donor-acceptor heterojunction morphology; high efficiency; molecular dynamics computation; polymer aggregation; post-fullerene solar cells

Citation Formats

Wang, Gang, Swick, Steven M., Matta, Micaela, Mukherjee, Subhrangsu, Strzalka, Joseph W., Logsdon, Jenna Leigh, Fabiano, Simone, Huang, Wei, Aldrich, Thomas J., Yang, Tony, Timalsina, Amod, Powers-Riggs, Natalia, Alzola, Joaquin M., Young, Ryan M., DeLongchamp, Dean M., Wasielewski, Michael R., Kohlstedt, Kevin L., Schatz, George C., Melkonyan, Ferdinand S., Facchetti, Antonio, and Marks, Tobin J. Photovoltaic Blend Microstructure for High Efficiency Post-Fullerene Solar Cells. To Tilt or Not To Tilt?. United States: N. p., 2019. Web. https://doi.org/10.1021/jacs.9b03770.
Wang, Gang, Swick, Steven M., Matta, Micaela, Mukherjee, Subhrangsu, Strzalka, Joseph W., Logsdon, Jenna Leigh, Fabiano, Simone, Huang, Wei, Aldrich, Thomas J., Yang, Tony, Timalsina, Amod, Powers-Riggs, Natalia, Alzola, Joaquin M., Young, Ryan M., DeLongchamp, Dean M., Wasielewski, Michael R., Kohlstedt, Kevin L., Schatz, George C., Melkonyan, Ferdinand S., Facchetti, Antonio, & Marks, Tobin J. Photovoltaic Blend Microstructure for High Efficiency Post-Fullerene Solar Cells. To Tilt or Not To Tilt?. United States. https://doi.org/10.1021/jacs.9b03770
Wang, Gang, Swick, Steven M., Matta, Micaela, Mukherjee, Subhrangsu, Strzalka, Joseph W., Logsdon, Jenna Leigh, Fabiano, Simone, Huang, Wei, Aldrich, Thomas J., Yang, Tony, Timalsina, Amod, Powers-Riggs, Natalia, Alzola, Joaquin M., Young, Ryan M., DeLongchamp, Dean M., Wasielewski, Michael R., Kohlstedt, Kevin L., Schatz, George C., Melkonyan, Ferdinand S., Facchetti, Antonio, and Marks, Tobin J. Mon . "Photovoltaic Blend Microstructure for High Efficiency Post-Fullerene Solar Cells. To Tilt or Not To Tilt?". United States. https://doi.org/10.1021/jacs.9b03770. https://www.osti.gov/servlets/purl/1560046.
@article{osti_1560046,
title = {Photovoltaic Blend Microstructure for High Efficiency Post-Fullerene Solar Cells. To Tilt or Not To Tilt?},
author = {Wang, Gang and Swick, Steven M. and Matta, Micaela and Mukherjee, Subhrangsu and Strzalka, Joseph W. and Logsdon, Jenna Leigh and Fabiano, Simone and Huang, Wei and Aldrich, Thomas J. and Yang, Tony and Timalsina, Amod and Powers-Riggs, Natalia and Alzola, Joaquin M. and Young, Ryan M. and DeLongchamp, Dean M. and Wasielewski, Michael R. and Kohlstedt, Kevin L. and Schatz, George C. and Melkonyan, Ferdinand S. and Facchetti, Antonio and Marks, Tobin J.},
abstractNote = {Achieving efficient polymer solar cells (PSCs) requires a structurally optimal donor-acceptor heterojunction morphology. In this paper, 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 analyse 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) computation which reveals 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. Finally, a straightforward energetic parameter explains the experimental polymer domain morphological trends, hence PCE, and suggests strategies for substituent selection to optimize PSC materials morphologies.},
doi = {10.1021/jacs.9b03770},
journal = {Journal of the American Chemical Society},
number = 34,
volume = 141,
place = {United States},
year = {2019},
month = {8}
}

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Figures / Tables:

Figure 1 Figure 1: Donor and acceptor materials and their physicochemical properties. a) P‐EH, P‐BO, P‐HD, P‐OD and ITIC‐Th molecular structures; b) Film optical absorption spectra of P‐EH, P‐BO, P‐HD, P‐OD, and ITIC‐Th. Neat films of the polymer were spin‐coated from PhCl solutions (5 mg mL‐1) and neat ITIC‐Th films were spin‐coatedmore » from CHCl3 solutions (5 mg mL‐1); c) Energy level diagrams for P‐EH, P‐BO, P‐HD, P‐OD, and ITIC‐Th.« less

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    Works referencing / citing this record:

    High-efficiency ternary nonfullerene polymer solar cells with increased phase purity and reduced nonradiative energy loss
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