Revealing temperature-dependent polymer aggregation in solution with small-angle X-ray scattering

Abdelsamie, Maged; Chaney, Thomas P.; Yan, Hongping; Schneider, Sebastian A.; Ayhan, I. Alperen; Gomez, Enrique D.; Reynolds, John R.; Toney, Michael F.

doi:10.1039/d1ta09086k

Revealing temperature-dependent polymer aggregation in solution with small-angle X-ray scattering

Journal Article · Thu Jan 06 00:00:00 EST 2022 · Journal of Materials Chemistry. A

DOI:https://doi.org/10.1039/d1ta09086k· OSTI ID:1862338

^[1]; ^[2]; Yan, Hongping ^[3]; Schneider, Sebastian A. ^[3]; Ayhan, I. Alperen ^[4]; Gomez, Enrique D. ^[4]; ^[5]; ^[6]

SLAC National Accelerator Lab., Menlo Park, CA (United States); Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
Univ. of Colorado, Boulder, CO (United States)
SLAC National Accelerator Lab., Menlo Park, CA (United States); Stanford Univ., CA (United States)
Pennsylvania State Univ., University Park, PA (United States)
Georgia Institute of Technology, Atlanta, GA (United States)
SLAC National Accelerator Lab., Menlo Park, CA (United States); Univ. of Colorado, Boulder, CO (United States)

We report that improving the morphology of bulk heterojunction active layers remains a primary challenge for organic photovoltaics (OPVs), and much research has been devoted to achieving this through modifying OPV casting solutions to control film formation and crystallinity. Yet, the solution conformation of conjugated polymers used in OPVs is largely unknown. Here, we report observations of temperature dependent aggregation (TDA) through small-angle X-ray scattering (SAXS) investigations of polymer conformation in chlorobenzene:dichlorobenzene casting solvent as a function of temperature for PffBT4T-2OD, a polymer known to display TDA, and its derivative PffBT3T-2OD which displays significantly reduced TDA. We find that, upon cooling below 80 °C, PffBT4T-2OD forms large crystalline aggregates in solution, while its derivative PffBT3T-2OD forms mostly amorphous aggregates of similar size with some evidence of short-range order. This change in solution aggregation behavior is reflected in the lack of gelation by PffBT3T-2OD upon film deposition by spin coating. Grazing-incidence wide-angle X-ray scattering (GIWAXS) revealed a preferred face-on π–π stacking orientation for PffBT3T-2OD films while PffBT4T-2OD's π–π stacking peak was isotropic. We combine these findings to suggest that the presence of crystalline seed aggregates in PffBT4T-2OD solution quickly form an isotropic crystallite network upon cooling while PffBT3T-2OD's amorphous aggregates more slowly crystallize resulting in improved processability of PffBT3T-2OD.

View Accepted Manuscript (DOE)

Research Organization:: Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States); SLAC National Accelerator Laboratory (SLAC), Menlo Park, CA (United States)

Sponsoring Organization:: Office of Naval Research; USDOE; USDOE Office of Science (SC), Basic Energy Sciences (BES)

Grant/Contract Number:: AC02-76SF00515

OSTI ID:: 1862338

Alternate ID(s):: OSTI ID: 1839462

Journal Information:: Journal of Materials Chemistry. A, Journal Name: Journal of Materials Chemistry. A Journal Issue: 4 Vol. 10; ISSN 2050-7488

Publisher:: Royal Society of ChemistryCopyright Statement

Country of Publication:: United States

Language:: English

References (36)

Conjugated Block Copolymers as Model Systems to Examine Mechanisms of Charge Generation in Donor-Acceptor Materials Aplan, Melissa P.; Grieco, Christopher; Lee, Youngmin Advanced Functional Materials, Vol. 29, Issue 1 https://doi.org/10.1002/adfm.201804858	journal	November 2018
Efficient Polymer Solar Cells Based on a Low Bandgap Semi-crystalline DPP Polymer-PCBM Blends Liu, Feng; Gu, Yu; Wang, Cheng Advanced Materials, Vol. 24, Issue 29 https://doi.org/10.1002/adma.201200902	journal	June 2012
A Mechanistic Understanding of Processing Additive-Induced Efficiency Enhancement in Bulk Heterojunction Organic Solar Cells Schmidt, Kristin; Tassone, Christopher J.; Niskala, Jeremy R. Advanced Materials, Vol. 26, Issue 2 https://doi.org/10.1002/adma.201303622	journal	October 2013
Solvent Additives: Key Morphology-Directing Agents for Solution-Processed Organic Solar Cells McDowell, Caitlin; Abdelsamie, Maged; Toney, Michael F. Advanced Materials, Vol. 30, Issue 33 https://doi.org/10.1002/adma.201707114	journal	June 2018
Hot Hydrocarbon‐Solvent Slot‐Die Coating Enables High‐Efficiency Organic Solar Cells with Temperature‐Dependent Aggregation Behavior Zhao, Heng; Naveed, Hafiz Bilal; Lin, Baojun Advanced Materials, Vol. 32, Issue 39 https://doi.org/10.1002/adma.202002302	journal	August 2020
Critical Role of Polymer Aggregation and Miscibility in Nonfullerene‐Based Organic Photovoltaics Yi, Xueping; Peng, Zhengxing; Xu, Bing Advanced Energy Materials, Vol. 10, Issue 8 https://doi.org/10.1002/aenm.201902430	journal	January 2020
Influence of Polymer Aggregation and Liquid Immiscibility on Morphology Tuning by Varying Composition in PffBT4T‐2DT/Nonfullerene Organic Solar Cells Hamid, Zeinab; Wadsworth, Andrew; Rezasoltani, Elham Advanced Energy Materials, Vol. 10, Issue 8 https://doi.org/10.1002/aenm.201903248	journal	January 2020
Stabilization of bulk aggregation state in semiconducting polymer solutions Hua, Chi Chung; Lin, Chih Jung; Wen, Yu Ho Journal of Polymer Research, Vol. 18, Issue 4 https://doi.org/10.1007/s10965-010-9476-3	journal	July 2010
Recent Advances to Understand Morphology Stability of Organic Photovoltaics Guerrero, Antonio; Garcia-Belmonte, Germà Nano-Micro Letters, Vol. 9, Issue 1 https://doi.org/10.1007/s40820-016-0107-3	journal	October 2016
Design of Donor Polymers with Strong Temperature-Dependent Aggregation Property for Efficient Organic Photovoltaics Hu, Huawei; Chow, Philip C. Y.; Zhang, Guangye Accounts of Chemical Research, Vol. 50, Issue 10 https://doi.org/10.1021/acs.accounts.7b00293	journal	September 2017
Mixing Behavior in Small Molecule:Fullerene Organic Photovoltaics Oosterhout, Stefan D.; Savikhin, Victoria; Zhang, Junxiang Chemistry of Materials, Vol. 29, Issue 7 https://doi.org/10.1021/acs.chemmater.7b00067	journal	March 2017
Small Molecule Acceptor and Polymer Donor Crystallinity and Aggregation Effects on Microstructure Templating: Understanding Photovoltaic Response in Fullerene-Free Solar Cells Eastham, Nicholas D.; Dudnik, Alexander S.; Aldrich, Thomas J. Chemistry of Materials, Vol. 29, Issue 10 https://doi.org/10.1021/acs.chemmater.7b00964	journal	May 2017
Temperature Induced Order–Disorder Transition in Solutions of Conjugated Polymers Probed by Optical Spectroscopy Panzer, Fabian; Bässler, Heinz; Köhler, Anna The Journal of Physical Chemistry Letters, Vol. 8, Issue 1 https://doi.org/10.1021/acs.jpclett.6b01641	journal	December 2016
Solution-Phase Conformation and Dynamics of Conjugated Isoindigo-Based Donor–Acceptor Polymer Single Chains Lee, Franklin L.; Barati Farimani, Amir; Gu, Kevin L. The Journal of Physical Chemistry Letters, Vol. 8, Issue 22 https://doi.org/10.1021/acs.jpclett.7b02360	journal	October 2017
Role of Solution Structure in Self-Assembly of Conjugated Block Copolymer Thin Films Brady, Michael A.; Ku, Sung-Yu; Perez, Louis A. Macromolecules, Vol. 49, Issue 21 https://doi.org/10.1021/acs.macromol.6b01686	journal	October 2016
Randomly Distributed Conjugated Polymer Repeat Units for High-Efficiency Photovoltaic Materials with Enhanced Solubility and Processability Xu, Bing; Pelse, Ian; Agarkar, Shruti ACS Applied Materials & Interfaces, Vol. 10, Issue 51 https://doi.org/10.1021/acsami.8b15522	journal	November 2018
Time-Resolved Structural Evolution of Additive-Processed Bulk Heterojunction Solar Cells Rogers, James T.; Schmidt, Kristin; Toney, Michael F. Journal of the American Chemical Society, Vol. 134, Issue 6 https://doi.org/10.1021/ja2104747	journal	February 2012
Exciton-Dissociation and Charge-Recombination Processes in Pentacene/C ₆₀ Solar Cells: Theoretical Insight into the Impact of Interface Geometry Yi, Yuanping; Coropceanu, Veaceslav; Brédas, Jean-Luc Journal of the American Chemical Society, Vol. 131, Issue 43 https://doi.org/10.1021/ja905975w	journal	November 2009
Fine-Tuning Semiconducting Polymer Self-Aggregation and Crystallinity Enables Optimal Morphology and High-Performance Printed All-Polymer Solar Cells Wu, Yilei; Schneider, Sebastian; Walter, Christopher Journal of the American Chemical Society, Vol. 142, Issue 1 https://doi.org/10.1021/jacs.9b10935	journal	December 2019
Aggregation of a poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) triblock copolymer in aqueous solution studied using Rayleigh-Brillouin and dynamic light scattering Schillen, Karin; Brown, Wyn; Konak, Cestmir Macromolecules, Vol. 26, Issue 14 https://doi.org/10.1021/ma00066a020	journal	July 1993
Polymer Chain Shape of Poly(3-alkylthiophenes) in Solution Using Small-Angle Neutron Scattering McCulloch, Bryan; Ho, Victor; Hoarfrost, Megan Macromolecules, Vol. 46, Issue 5 https://doi.org/10.1021/ma302463d	journal	February 2013
Aggregation and morphology control enables multiple cases of high-efficiency polymer solar cells Liu, Yuhang; Zhao, Jingbo; Li, Zhengke Nature Communications, Vol. 5, Issue 1 https://doi.org/10.1038/ncomms6293	journal	November 2014
Flow-enhanced solution printing of all-polymer solar cells Diao, Ying; Zhou, Yan; Kurosawa, Tadanori Nature Communications, Vol. 6, Issue 1 https://doi.org/10.1038/ncomms8955	journal	August 2015
Glass transition temperature from the chemical structure of conjugated polymers Xie, Renxuan; Weisen, Albree R.; Lee, Youngmin Nature Communications, Vol. 11, Issue 1 https://doi.org/10.1038/s41467-020-14656-8	journal	February 2020
Exciton diffusion in organic photovoltaic cells Menke, S. Matthew; Holmes, Russell J. Energy Environ. Sci., Vol. 7, Issue 2 https://doi.org/10.1039/C3EE42444H	journal	January 2014
Reducing burn-in voltage loss in polymer solar cells by increasing the polymer crystallinity Heumueller, Thomas; Mateker, William R.; Sachs-Quintana, I. T. Energy Environ. Sci., Vol. 7, Issue 9 https://doi.org/10.1039/C4EE01842G	journal	January 2014
Critical review of the molecular design progress in non-fullerene electron acceptors towards commercially viable organic solar cells Wadsworth, Andrew; Moser, Maximilian; Marks, Adam Chemical Society Reviews, Vol. 48, Issue 6 https://doi.org/10.1039/C7CS00892A	journal	January 2019
Simple transfer from spin coating to blade coating through processing aggregated solutions Hernandez, Jeff L.; Deb, Nabankur; Wolfe, Rylan M. W. Journal of Materials Chemistry A, Vol. 5, Issue 39 https://doi.org/10.1039/C7TA05214F	journal	January 2017
Molecular weight tuning of low bandgap polymers by continuous flow chemistry: increasing the applicability of PffBT4T for organic photovoltaics Pirotte, Geert; Agarkar, Shruti; Xu, Bing Journal of Materials Chemistry A, Vol. 5, Issue 34 https://doi.org/10.1039/C7TA05627C	journal	January 2017
Understanding, quantifying, and controlling the molecular ordering of semiconducting polymers: from novices to experts and amorphous to perfect crystals Peng, Zhengxing; Ye, Long; Ade, Harald Materials Horizons https://doi.org/10.1039/D0MH00837K	journal	January 2022
Irena : tool suite for modeling and analysis of small-angle scattering Ilavsky, Jan; Jemian, Peter R. Journal of Applied Crystallography, Vol. 42, Issue 2 https://doi.org/10.1107/S0021889809002222	journal	February 2009
Analysis of the Beaucage model Hammouda, Boualem Journal of Applied Crystallography, Vol. 43, Issue 6 https://doi.org/10.1107/S0021889810033856	journal	October 2010
Nika : software for two-dimensional data reduction Ilavsky, Jan Journal of Applied Crystallography, Vol. 45, Issue 2 https://doi.org/10.1107/S0021889812004037	journal	March 2012
Approximations Leading to a Unified Exponential/Power-Law Approach to Small-Angle Scattering Beaucage, G. Journal of Applied Crystallography, Vol. 28, Issue 6 https://doi.org/10.1107/S0021889895005292	journal	December 1995
Small-Angle Scattering from Polymeric Mass Fractals of Arbitrary Mass-Fractal Dimension Beaucage, G. Journal of Applied Crystallography, Vol. 29, Issue 2 https://doi.org/10.1107/S0021889895011605	journal	April 1996
Recent Developments in the Optimization of the Bulk Heterojunction Morphology of Polymer: Fullerene Solar Cells Gaspar, Hugo; Figueira, Flávio; Pereira, Luiz Materials, Vol. 11, Issue 12 https://doi.org/10.3390/ma11122560	journal	December 2018

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