Energy level alignment at molecule-metal interfaces from an optimally tuned range-separated hybrid functional

Zhen Fei Liu, David A. Egger, Sivan Refaely-Abramson, Leeor Kronik, Jeffrey B. Neaton

Research output: Contribution to journalArticlepeer-review

65 Scopus citations

Abstract

The alignment of the frontier orbital energies of an adsorbed molecule with the substrate Fermi level at metal-organic interfaces is a fundamental observable of significant practical importance in nanoscience and beyond. Typical density functional theory calculations, especially those using local and semi-local functionals, often underestimate level alignment leading to inaccurate electronic structure and charge transport properties. In this work, we develop a new fully self-consistent predictive scheme to accurately compute level alignment at certain classes of complex heterogeneous molecule-metal interfaces based on optimally tuned range-separated hybrid functionals. Starting from a highly accurate description of the gas-phase electronic structure, our method by construction captures important nonlocal surface polarization effects via tuning of the long-range screened exchange in a range-separated hybrid in a non-empirical and system-specific manner. We implement this functional in a plane-wave code and apply it to several physisorbed and chemisorbed molecule-metal interface systems. Our results are in quantitative agreement with experiments, the both the level alignment and work function changes. Our approach constitutes a new practical scheme for accurate and efficient calculations of the electronic structure of molecule-metal interfaces.

Original languageEnglish
Article number092326
JournalJournal of Chemical Physics
Volume146
Issue number9
DOIs
StatePublished - 7 Mar 2017
Externally publishedYes

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