Spatially-resolved molecular Quantum Dots at the Surface of a Gated Graphene Device

ORAL

Abstract

The ability to modify the electronic properties of monolayer graphene via charge-donating or charge-accepting molecules creates new opportunities for fabricating nano-scale hybrid devices. Understanding the charge transfer process at the single molecule level is essential for tuning the electronic and magnetic characteristics of such hybrid devices. We have used scanning tunneling microscopy (STM) to locally probe how different molecular assemblies (including single molecules, molecular chains, and 2D molecular islands) exchange charge with a graphene substrate as the device backgate voltage is varied. Different molecular configurations exhibit substantially different charging behavior - some are permanently charged while others can be controllably ionized using the device backgate. Electrostatic interactions lead to charge heterogeneity at the molecular level. Single-chemical-bond-resolved atomic force microscopy allows us to correlate chemical structure and adsorption geometry of the molecules with their electronic properties.

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Authors

  • Hsin-Zon Tsai

    UC Berkeley physics/ LBNL

  • Sebastian Wickenburg

    UC Berkeley physics/ LBNL

  • Jiong Lu

    UC Berkeley physics/ NUS Graphene Research Centre

  • Arash A. Omrani

    UC Berkeley physics

  • Sinisa Coh

    University of California at Berkeley, Lawrence Berkeley National Lab, UC Berkeley, Lawrence Berkeley National Laboratory, UC Berkeley physics

  • Han Sae Jung

    UC Berkeley physics

  • Dillon Wong

    UC Berkeley physics

  • Johannes Lischner

    UC Berkeley physics

  • Ramin Khajeh

    UC Berkeley physics

  • Alexander Riss

    UC Berkeley physics/ TU Wien applied physics

  • Aaron J. Bradley

    Physics Dept. UC Berkeley, UC Berkeley physics

  • Erik Piatti

    Politecnico di Torino DISAT

  • Alex Zettl

    UC Berkeley, Department of Physics, University of California, Berkeley, CA 94720, USA, UC Berkeley physics/ LBNL MSD

  • Steven G. Louie

    University of California at Berkeley, Lawrence Berkeley National Lab, University of California - Berkeley and Lawrence Berkeley National Lab, Department of Physics, University of California at Berkeley; Materials Sciences Divisions, Lawrence Berkeley National Laboratory, Univ of California - Berkeley and Lawrence Berkeley National Lab, Department of Physics, UC Berkeley and Lawrence Berkeley National Lab, University of California, Berkeley and Lawrence Berkeley National Laboratory, University of California at Berkeley and Lawrence Berkeley National Laboratory, UC Berkeley and Lawrence Berkeley National Lab, University of California at Berkeley and Lawrence Berkeley National Lab, Physics Department, UC Berkeley and Lawrence Berkeley National Lab, Department of Physics, University of California, Berkeley, and Materials Science Division, Lawrence Berkeley National Lab, Berkeley, CA 94720, USA, UC Berkeley physics/ LBNL MSD

  • Marvin L. Cohen

    University of California at Berkeley, Lawrence Berkeley National Lab, UC Berkeley and Lawrence Berkeley National Lab, UC Berkeley, Lawrence Berkeley National Laboratory, UC Berkeley physics/ LBNL MSD

  • Michael Crommie

    UC Berkeley physics/ LBNL MSD, UC Berkeley