Mechanical and Electrical Studies of Two-dimensional Covalent Organic Frameworks

ORAL

Abstract

Two-dimensional (2D) covalent organic frameworks (COFs) are a promising new class of 2D materials with the potential for highly-tunable chemical, mechanical, electrical, and optical properties. As porous polymers, 2D COFs are predicted to have a combination of low mass density and high mechanical strength. Here we discuss mechanical and electrical measurements on COF thin films. For the mechanical measurements, we have developed a protocol for synthesizing COF films as thin as 1.5 nm at a liquid-liquid interface, lifting and drying them on a PDMS stamp, and then performing a dry transfer onto a prepatterned substrate to make suspended COF films. The transferred films exhibit excellent uniformity, smoothness, and cleanliness. We report results for the 2D Young’s modulus and mechanical strength using nanoindentation measurements performed using an atomic force microscope. We will also discuss initial electrical measurements on COF films designed to have small energy gaps.

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Presenters

  • Ruofan Li

    Cornell University, Physics, Cornell University

Authors

  • Ruofan Li

    Cornell University, Physics, Cornell University

  • Michio Matsumoto

    Northwestern University

  • Amanda Corcos

    Northwestern University

  • Halleh Balch

    University of California - Berkeley, Physics, University of California, Berkeley

  • Raghunath Dasari

    Georgia Institute of Technology, Chemistry, Georgia Tech

  • Austin Evans

    Northwestern University, Chemistry, Northwestern University

  • Gregory Stiehl

    Cornell University, Department of Physics, Cornell University

  • Seth R. Marder

    Georgia Institute of Technology, Chemistry, Georgia Institute of Technology, Chemistry, Georgia Tech

  • Feng Wang

    University of California - Berkeley, University of California, Berkeley, Physics, UC Berkeley, Department of Physics, University of California at Berkeley, Berkeley, CA 94709, USA, University of California at Berkeley, Lawrence Berkeley National Laboratory and UC Berkeley, UC Berkeley, Physics, University of California, Berkeley

  • William Dichtel

    Northwestern University, Chemistry, Northwestern University

  • Daniel Ralph

    Cornell University, Department of Physics, Cornell University