Ultra-Long-Range Resonant Transport Through Open-Shell Donor-Acceptor Macromolecules

ORAL

Abstract

Design and development of highly conducting molecular materials facilitating the ultra-long-range charge transport play a pivotal role in the development of emerging molecular scale technologies such as sensing, electronics, spintronics and quantum information science. The past two decades have witnessed a new generation of miniaturized electronic based on molecules whose synthetic tunability provides unparalleled functionalities absent in conventional electronic materials. Nonetheless, current design strategies lead to molecules that exhibit off-resonant charge transport, which restricts the conductance to several orders of magnitude below the conductance quantum 1 G0 and result in an exponential decay in conductance with length. Here, we present a robust, air stable, and highly tunable molecular wire platform composed of open-shell donor-acceptor macromolecules that show remarkably high conductance close to 1G0 over a length exceeding 20 nm under low bias, with no decay with length. Our single molecular transport measurements along with ab initio calculations demonstrate that the ultra-long range resonant charge transport is attributable to π-conjugation, narrow bandgap, and diradical character, which synergistically enables excellent alignment of frontier molecular orbitals with the electrode Fermi energy. This breakthrough in this long-sought-after transport regime within molecular materials opens new possibilities for incorporating a range of properties into advanced nanoelectronic technologies.

*We thank the financial support from the U.S. Department of Energy, Office of Science, Basic Energy Sciences under Award No. DE-SC0024924. The work performed at The Georgia Institute of Technology was made possible by the National Science Foundation (NSF) awards OIA-2317822 and DMR-2323665, and the Air Force Office of Scientific Research (AFOSR) under support provided by the Organic Materials Chemistry Program (Grant FA9550-23-1-0654). I.F. is supported by the NSF under Grant Nos. CHE-2102386 and PHY-2310657. Computational resources were provided by the Center for Integrated Research Computing (CIRC) at the University of Rochester.

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Publication: Shen et al. Ultra-Long-Range Resonant Transport Through Open-Shell Donor-Acceptor Macromolecules, Journal of American Chemical Society 2025, (Submitted)

Presenters

  • Mehrdad Shiri

    • Department of Physics, University of Miami, Coral Gables, FL 33146, United States.

Authors

  • Mehrdad Shiri

    • Department of Physics, University of Miami, Coral Gables, FL 33146, United States.

  • Shaocheng Shen

    • Department of Chemistry, University of Miami, Coral Gables, FL 33146, United States.

  • Paramasivam Mahalingam

    • School of Chemistry and Biochemistry, School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, GA 30332, United States.

  • Chaolong Tang

    • Department of Physics and astronomy, Mississippi State University, Mississippi State, MS 39762, United States.

  • Tyler Bills

    • School of Chemistry and Biochemistry, School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, GA 30332, United States.

  • Alexander J Bushnell

    • School of Chemistry and Biochemistry, School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, GA 30332, United States.

  • Tanya A Balandin

    • School of Chemistry and Biochemistry, School of Materials Science and Engineering, Center for Organic Photonics and Electronics, Georgia Institute of Technology, Atlanta, GA 3

  • Leopoldo Mejía

    • Departamento de Física y Astronomía, Facultad de Ciencias Exactas, Universidad Andrés Bello, Santiago 837-0136, Chile.

  • haixin Zhang

    • Department of Physics, University of Miami, Coral Gables, FL 33146, United States.

  • Bingqian Xu

    • Single Molecule Study Laboratory, College of Engineering and Nanoscale Science and Engineering Center, University of Georgia, Athens, GA 30602, United States.

  • Ignacio Franco

    • University of Rochester

  • Jason D Azoulay

    • School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, GA 30332, United States.

  • Kun Wang

    • Department of Physics, University of Miami, Coral Gables, FL 33146, United States.