Metal Bistriflimide Doping of MEH-PPV: Linking Ionic Crosslinking to Enhanced Conductivity and Stability

ORAL

Abstract

The incorporation of metal bistriflimide (M(TFSI)n) salts into conjugated polymers provides a tunable approach to control charge transport and film morphology through coordination-driven interactions. Here, we examine MEH-PPV doped with LiTFSI, Zn(TFSI)2, and La(TFSI)3 to elucidate how metal valency and ionic size influence structural reorganization and conductivity. Spectroscopic analysis (FTIR, Raman, and XPS) reveals coordination of metal cations to ether and carbonyl oxygens, forming ionic crosslinks that promote film densification and improve both stability and electronic conductivity. La(TFSI)3 induces the strongest coordination, resulting in a smooth, uniform morphology and conductivity enhancements exceeding 10-3 S cm-1 with improved ambient stability. XPS O 1s and C 1s shifts confirm electron density withdrawal upon coordination, while optical measurements show preserved π–π interactions. These findings establish a clear structure–property relationship between ion coordination and charge transport, underscoring metal bistriflimide doping as a promising route to stable, high-conductivity polymer thin films for optoelectronic applications.

*This work was supported by the National Science Foundation under Grant No. ECCS-2330929. Instrumentation access was provided by the NYU Shared Instrument Facility, constructed with support from the National Center for Research Resources, National Institutes of Health (Award No. C06 RR-16572-01). Research was also carried out at the Materials Synthesis and Characterization Facility of the Center for Functional Nanomaterials, a U.S. Department of Energy Office of Science User Facility at Brookhaven National Laboratory, under Contract No. DE-SC0012704.

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Publication: Seth W. McPherson, Yeh-Chuan Chou, Insoo Shin, Stephen A. Maclean, Dmytro Nykypanchuk, Tai-de Li, Chieh-Ting Lin, Jaemin Kong, Jason A. Röhr, Andre D. Taylor, Coordination-Based Doping of MEH-PPV with La(TFSI)3 Enables Air-Free Conductivity and Stable Performance in Perovskite Solar Cells, Organic Electronics, 2025,107351, https://doi.org/10.1016/j.orgel.2025.107351.

Presenters

  • Seth W McPherson

    • New York University, Tandon School of Engineering

Authors

  • Seth W McPherson

    • New York University, Tandon School of Engineering

  • Yeh-Chuan Cho

    • Department of Chemical Engineering, National Chung Hsing University, Taichung City, Taiwan

  • Insoo Shin

    • Department of Chemical and Biomolecular Engineering, Tandon School of Engineering, New York University, Brooklyn, 11201, NY, USA

  • Stephen A Maclean

    • Department of Chemical and Biomolecular Engineering, Tandon School of Engineering, New York University, Brooklyn, 11201, NY, USA

  • Dmytro Nykypanchuk

    • Center for Functional Nanomaterials, Brookhaven National Laboratory, Upton, New York 11973, USA

  • Tai-De Li

    • Advanced Science Research Center, Graduate Center of City University of New York, New York, NY, 10031 USA
    • CUNY

  • Chieh-ting Lin

    • Department of Chemical Engineering, National Chung Hsing University, Taichung City, Taiwan

  • Jaemin Kong

    • Research Institute of Natural Science, Gyeongsang National University, Jinju, South Gyeongsang, 52828, Republic of Korea

  • Jason A Röhr

    • General Engineering, Tandon School of Engineering, New York University, Brooklyn, 11201, NY, USA

  • Andre D Taylor

    • Department of Chemical and Biomolecular Engineering, Tandon School of Engineering, New York University, Brooklyn, 11201, NY, USA