skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: The energy level alignment at metal–molecule interfaces using Wannier–Koopmans method

Abstract

We apply a recently developed Wannier–Koopmans method (WKM), based on density functional theory (DFT), to calculate the electronic energy level alignment at an interface between a molecule and metal substrate. We consider two systems: benzenediamine on Au (111), and a bipyridine-Au molecular junction. The WKM calculated level alignment agrees well with the experimental measurements where available, as well as previous GW and DFT + Σ results. Our results suggest that the WKM is a general approach that can be used to correct DFT eigenvalue errors, not only in bulk semiconductors and isolated molecules, but also in hybrid interfaces.

Authors:
;  [1];  [1];  [2];  [1];  [2];  [2];  [2]
  1. Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States)
  2. (United States)
Publication Date:
OSTI Identifier:
22590621
Resource Type:
Journal Article
Resource Relation:
Journal Name: Applied Physics Letters; Journal Volume: 108; Journal Issue: 26; Other Information: (c) 2016 Author(s); Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; ALIGNMENT; BIPYRIDINES; DENSITY FUNCTIONAL METHOD; EIGENVALUES; ENERGY LEVELS; ERRORS; INTERFACES; METALS; MOLECULES; SEMICONDUCTOR MATERIALS; SUBSTRATES

Citation Formats

Ma, Jie, Wang, Lin-Wang, E-mail: lwwang@lbl.gov, Liu, Zhen-Fei, Department of Physics, University of California, Berkeley, California, 94720, Neaton, Jeffrey B., Department of Physics, University of California, Berkeley, California, 94720, Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, California 94720, and Kavli Energy Nanoscience Institute at Berkeley, Berkeley, California 94720. The energy level alignment at metal–molecule interfaces using Wannier–Koopmans method. United States: N. p., 2016. Web. doi:10.1063/1.4955128.
Ma, Jie, Wang, Lin-Wang, E-mail: lwwang@lbl.gov, Liu, Zhen-Fei, Department of Physics, University of California, Berkeley, California, 94720, Neaton, Jeffrey B., Department of Physics, University of California, Berkeley, California, 94720, Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, California 94720, & Kavli Energy Nanoscience Institute at Berkeley, Berkeley, California 94720. The energy level alignment at metal–molecule interfaces using Wannier–Koopmans method. United States. doi:10.1063/1.4955128.
Ma, Jie, Wang, Lin-Wang, E-mail: lwwang@lbl.gov, Liu, Zhen-Fei, Department of Physics, University of California, Berkeley, California, 94720, Neaton, Jeffrey B., Department of Physics, University of California, Berkeley, California, 94720, Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, California 94720, and Kavli Energy Nanoscience Institute at Berkeley, Berkeley, California 94720. 2016. "The energy level alignment at metal–molecule interfaces using Wannier–Koopmans method". United States. doi:10.1063/1.4955128.
@article{osti_22590621,
title = {The energy level alignment at metal–molecule interfaces using Wannier–Koopmans method},
author = {Ma, Jie and Wang, Lin-Wang, E-mail: lwwang@lbl.gov and Liu, Zhen-Fei and Department of Physics, University of California, Berkeley, California, 94720 and Neaton, Jeffrey B. and Department of Physics, University of California, Berkeley, California, 94720 and Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, California 94720 and Kavli Energy Nanoscience Institute at Berkeley, Berkeley, California 94720},
abstractNote = {We apply a recently developed Wannier–Koopmans method (WKM), based on density functional theory (DFT), to calculate the electronic energy level alignment at an interface between a molecule and metal substrate. We consider two systems: benzenediamine on Au (111), and a bipyridine-Au molecular junction. The WKM calculated level alignment agrees well with the experimental measurements where available, as well as previous GW and DFT + Σ results. Our results suggest that the WKM is a general approach that can be used to correct DFT eigenvalue errors, not only in bulk semiconductors and isolated molecules, but also in hybrid interfaces.},
doi = {10.1063/1.4955128},
journal = {Applied Physics Letters},
number = 26,
volume = 108,
place = {United States},
year = 2016,
month = 6
}
  • We apply a recently developed Wannier-Koopmans method (WKM), based on density functional theory (DFT), to calculate the electronic energy level alignment at an interface between a molecule and metal substrate. We consider two systems: benzenediamine on Au (111), and a bipyridine-Au molecular junction. The WKM calculated level alignment agrees well with the experimental measurements where available, as well as previous GW and DFT + Σ results. These results suggest that the WKM is a general approach that can be used to correct DFT eigenvalue errors, not only in bulk semiconductors and isolated molecules, but also in hybrid interfaces.
  • Cited by 36
  • We report a key quantity for molecule–metal interfaces is the energy level alignment of molecular electronic states with the metallic Fermi level. We develop and apply an efficient theoretical method, based on density functional theory (DFT) that can yield quantitatively accurate energy level alignment information for physisorbed metal–molecule interfaces. The method builds on the “DFT+Σ” approach, grounded in many-body perturbation theory, which introduces an approximate electron self-energy that corrects the level alignment obtained from conventional DFT for missing exchange and correlation effects associated with the gas-phase molecule and substrate polarization. Here, we extend the DFT+Σ approach in two important ways:more » first, we employ optimally tuned range-separated hybrid functionals to compute the gas-phase term, rather than rely on GW or total energy differences as in prior work; second, we use a nonclassical DFT-determined image-charge plane of the metallic surface to compute the substrate polarization term, rather than the classical DFT-derived image plane used previously. We validate this new approach by a detailed comparison with experimental and theoretical reference data for several prototypical molecule–metal interfaces, where excellent agreement with experiment is achieved: benzene on graphite (0001), and 1,4-benzenediamine, Cu-phthalocyanine, and 3,4,9,10-perylene-tetracarboxylic-dianhydride on Au(111). In particular, we show that the method correctly captures level alignment trends across chemical systems and that it retains its accuracy even for molecules for which conventional DFT suffers from severe self-interaction errors.« less
    Cited by 30
  • We report a key quantity for molecule–metal interfaces is the energy level alignment of molecular electronic states with the metallic Fermi level. We develop and apply an efficient theoretical method, based on density functional theory (DFT) that can yield quantitatively accurate energy level alignment information for physisorbed metal–molecule interfaces. The method builds on the “DFT+Σ” approach, grounded in many-body perturbation theory, which introduces an approximate electron self-energy that corrects the level alignment obtained from conventional DFT for missing exchange and correlation effects associated with the gas-phase molecule and substrate polarization. Here, we extend the DFT+Σ approach in two important ways:more » first, we employ optimally tuned range-separated hybrid functionals to compute the gas-phase term, rather than rely on GW or total energy differences as in prior work; second, we use a nonclassical DFT-determined image-charge plane of the metallic surface to compute the substrate polarization term, rather than the classical DFT-derived image plane used previously. We validate this new approach by a detailed comparison with experimental and theoretical reference data for several prototypical molecule–metal interfaces, where excellent agreement with experiment is achieved: benzene on graphite (0001), and 1,4-benzenediamine, Cu-phthalocyanine, and 3,4,9,10-perylene-tetracarboxylic-dianhydride on Au(111). In particular, we show that the method correctly captures level alignment trends across chemical systems and that it retains its accuracy even for molecules for which conventional DFT suffers from severe self-interaction errors.« less
  • Cited by 6