Enhancing Polymer Photovoltaic Performance via Optimized Intramolecular Ester-Based Noncovalent Sulfur···Oxygen Interactions

Jianhua Chen, Qiaogan Liao, Gang Wang, Zhenglong Yan, Hang Wang, Yulun Wang, Xianhe Zhang, Yumin Tang, Antonio Facchetti, Tobin J Marks, Xugang Guo

Research output: Contribution to journalArticle

9 Citations (Scopus)

Abstract

Head-to-head (HH) bithiophenes are typically avoided in polymer semiconductors since they engender undesirable steric repulsions, leading to a twisted backbone. While introducing electron-donating alkoxy chains can lead to intramolecular noncovalent S···O interactions, this comes at the cost of elevating the HOMOs and compromising polymer solar cell (PSC) performance. To address the limitation, a novel HH bithiophene featuring an electron-withdrawing ester functionality, 3-alkoxycarbonyl-3′-alkoxy-2,2′-bithiophene (TETOR), is synthesized. Single crystal diffraction reveals a planar TETOR conformation (versus highly twisted diester bithiophene), showing distinctive advantages of incorporating alkoxy on promoting backbone planarity. Compared to first-generation 3-alkyl-3′-alkoxy-2,2′-bithiophene (TRTOR), TETOR contains an additional planarizing (thienyl)S···O(carbonyl) interaction. Consequently, TETOR-based polymer (TffBT-TETOR) has greatly lower-lying FMOs, stronger aggregation, closer π-stacking, and better miscibility with fullerenes versus the TRTOR-based counterpart (TffBT-TRTOR). These characteristics are attributed to the additional S···O interaction and electron-withdrawing ester substituent, which enhances backbone planarity, charge transport, and PSC performance. Thus, TffBT-TETOR-based PSCs exhibit an increased PCE of 10.08%, a larger Voc of 0.76 V, and a higher Jsc of 18.30 mA cm-2 than the TffBT-TRTOR-based PSCs. These results demonstrate that optimizing intramolecular noncovalent S···O interactions by incorporating electron-withdrawing ester groups is a powerful strategy for materials invention in organic electronics.

Original languageEnglish
Pages (from-to)3874-3885
Number of pages12
JournalMacromolecules
Volume51
Issue number10
DOIs
Publication statusPublished - May 22 2018

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Esters
Polymers
Electrons
Fullerenes
Patents and inventions
Conformations
Charge transfer
Electronic equipment
Agglomeration
Solubility
Diffraction
Single crystals
Semiconductor materials
alkoxyl radical
Polymer solar cells

ASJC Scopus subject areas

  • Organic Chemistry
  • Polymers and Plastics
  • Inorganic Chemistry
  • Materials Chemistry

Cite this

Enhancing Polymer Photovoltaic Performance via Optimized Intramolecular Ester-Based Noncovalent Sulfur···Oxygen Interactions. / Chen, Jianhua; Liao, Qiaogan; Wang, Gang; Yan, Zhenglong; Wang, Hang; Wang, Yulun; Zhang, Xianhe; Tang, Yumin; Facchetti, Antonio; Marks, Tobin J; Guo, Xugang.

In: Macromolecules, Vol. 51, No. 10, 22.05.2018, p. 3874-3885.

Research output: Contribution to journalArticle

Chen, J, Liao, Q, Wang, G, Yan, Z, Wang, H, Wang, Y, Zhang, X, Tang, Y, Facchetti, A, Marks, TJ & Guo, X 2018, 'Enhancing Polymer Photovoltaic Performance via Optimized Intramolecular Ester-Based Noncovalent Sulfur···Oxygen Interactions', Macromolecules, vol. 51, no. 10, pp. 3874-3885. https://doi.org/10.1021/acs.macromol.8b00161
Chen, Jianhua ; Liao, Qiaogan ; Wang, Gang ; Yan, Zhenglong ; Wang, Hang ; Wang, Yulun ; Zhang, Xianhe ; Tang, Yumin ; Facchetti, Antonio ; Marks, Tobin J ; Guo, Xugang. / Enhancing Polymer Photovoltaic Performance via Optimized Intramolecular Ester-Based Noncovalent Sulfur···Oxygen Interactions. In: Macromolecules. 2018 ; Vol. 51, No. 10. pp. 3874-3885.
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