Electrostatic Design of Polar Metal–Organic Framework Thin Films

Giulia Nascimbeni, Christof Wöll, Egbert Zojer

Research output: Contribution to journalArticlepeer-review

Abstract

In recent years, optical and electronic properties of metal–organic frameworks (MOFs) have increasingly shifted into the focus of interest of the scientific community. Here, we discuss a strategy for conveniently tuning these properties through electrostatic design. More specifically, based on quantum-mechanical simulations, we suggest an approach for creating a gradient of the electrostatic potential within a MOF thin film, exploiting collective electrostatic effects. With a suitable orientation of polar apical linkers, the resulting non-centrosymmetric packing results in an energy staircase of the frontier electronic states reminiscent of the situation in a pin-photodiode. The observed one dimensional gradient of the electrostatic potential causes a closure of the global energy gap and also shifts core-level energies by an amount equaling the size of the original band gap. The realization of such assemblies could be based on so-called pillared layer MOFs fabricated in an oriented fashion on a solid substrate employing layer by layer growth techniques. In this context, the simulations provide guidelines regarding the design of the polar apical linker molecules that would allow the realization of MOF thin films with the (vast majority of the) molecular dipole moments pointing in the same direction.

Original languageEnglish
Article number2420
Number of pages18
JournalNanomaterials
Volume10
Issue number12
DOIs
Publication statusPublished - 3 Dec 2020

Keywords

  • Bonding asymmetry
  • Density functional theory
  • Electronic structure
  • Electrostatic design
  • Metal–organic frameworks
  • Polar MOFs
  • Work-function change

ASJC Scopus subject areas

  • Chemical Engineering(all)
  • Materials Science(all)

Fields of Expertise

  • Advanced Materials Science

Treatment code (Nähere Zuordnung)

  • Basic - Fundamental (Grundlagenforschung)

Cooperations

  • NAWI Graz
  • Porous Materials @ Work

    1/07/1830/06/21

    Project: Research area

Cite this