A Green's Function Approach for Determining Surface Induced Broadening and Shifting of Molecular Energy Levels

Tamar Zelovich, Thorsten Hansen, Mark E. Tuckerman

Research output: Contribution to journalArticlepeer-review

Abstract

Upon adsorption of a molecule onto a surface, the molecular energy levels (MELs) broaden and change their alignment. This phenomenon directly affects electron transfer across the interface and is, therefore, a fundamental observable that influences electrochemical device performance. Here, we propose a rigorous parameter-free framework, built upon the theoretical construct of Green's functions, for studying the interface between a molecule and a bulk surface and its effect on MELs. The method extends beyond the usual wide-band limit approximation, and its generality allows its use with any level of electronic structure theory. We demonstrate its ability to predict the broadening and shifting of MELs as a function of intramolecular coupling, molecule/surface coupling, and the surface density of states for a molecule with two MELs adsorbed on a one-dimensional model metal surface. The new approach could help provide guidelines for the design and experimental characterization of electrochemical devices with optimal electron transport.

Original languageEnglish (US)
Pages (from-to)9854-9860
Number of pages7
JournalNano Letters
Volume22
Issue number24
DOIs
StatePublished - Dec 28 2022

Keywords

  • Alignment
  • Broadening
  • Molecular Energy Levels
  • Molecule Adsorption
  • Molecule/Surface Interface
  • Shifting

ASJC Scopus subject areas

  • Bioengineering
  • Chemistry(all)
  • Materials Science(all)
  • Condensed Matter Physics
  • Mechanical Engineering

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