Local electronic structure of single-layer Kagomé MOFs on carbon surfaces

ORAL

Abstract

Metal–organic frameworks (MOFs) are crystalline lattices that exhibit metal nodes bridged by π-conjugated organic ligands. The 2D molecular connectivity of MOFs provides a chemically programmable platform for engineering lattice symmetry and band structure. We have realized single-layer Kagomé-type Ni-HITP MOFs on highly oriented pyrolytic graphite (HOPG) using dual-source chemical vapor epitaxy (CVE). Scanning tunneling microscopy imaging reveals long-range Kagomé order for this 2D system. Spatially resolved dI/dV spectra show frontier states consistent with Kagomé-band physics, i.e., a flat-band feature and a Dirac-like crossing that are reproduced by density-functional calculations. 2D device compatibility of this MOF was demonstrated by also using monolayer graphene/hBN devices with prepatterned contacts and back-gates as Kagomé growth substrates via CVE. This resulted in well-ordered Kagomé MOFs with characteristic local spectral features. The aim of this approach is to enable electrostatic tuning of single-layer Kagomé materials via backgating of a graphene device support in the absence of reactive metal substrates. These results establish a new route for interrogating single-layer Kagomé phenomena.

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Presenters

  • Ziyi Wang

    • University of California, Berkeley

Authors

  • Ziyi Wang

    • University of California, Berkeley

  • Rafal Zuzak

    • University of California, Berkeley

  • Weichen Tang

    • Department of Physics, University of California at Berkeley and Materials Sciences Division, Lawrence Berkeley National Laboratory
    • University of California, Berkeley

  • Haowen Pang

    • Peking University
    • University of California, Berkeley

  • Andrew Sun

    • University of California, Berkeley

  • Aining Hu

    • University of California, Berkeley

  • Yutang Qiao

    • University of California, Berkeley

  • Yuqiao Yan

    • University of California, Berkeley

  • Steven G Louie

    • University of California, Berkeley
    • Department of Physics, University of California, Berkeley, CA, USA; Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
    • Department of Physics, University of California at Berkeley and Materials Sciences Division, Lawrence Berkeley National Laboratory

  • Michael F Crommie

    • University of California, Berkeley