Theoretical investigation on electron transport through an organic molecule: Effect of the contact structure

Nara, Jun; Geng, W. T.; Kino, Hiori; Kobayashi, Nobuhiko; Ohno, Takahisa

doi:10.1063/1.1783251

Cited by 63 publications

(67 citation statements)

References 28 publications

(21 reference statements)

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“…Using a quantum chemistry approach 35 we study the electronic structure of the molecules in gas phase and sandwiched between gold atoms in the junctions, as well as their transport properties (see supplementary information for details). In agreement with the literature, our calculations predict a chemisorbed system [36][37][38] with ZnTPPdT acting as acceptor, and the hollow site as the most stable configuration. Fig.…”

Section: Dft Calculationssupporting

confidence: 89%

Large tunable image-charge effects in single-molecule junctions

et al. 2013

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The characteristics of molecular electronic devices are critically determined by metal-organic interfaces, which influence the arrangement of the orbital levels that participate in charge transport.Studies on self-assembled monolayers (SAMs) show (molecule-dependent) level shifts as well as transport-gap renormalization, suggesting that polarization effects in the metal substrate play a key role in the level alignment with respect to the metal's Fermi energy. Here, we provide direct evidence for an electrode-induced gap renormalization in single-molecule junctions. We study charge transport in single porphyrin-type molecules using electrically gateable break junctions.In this set-up, the position of the occupied and unoccupied levels can be followed in situ and with simultaneous mechanical control. When increasing the electrode separation, we observe a substantial increase in the transport gap with level shifts as high as several hundreds of meV for displacements of a fewÅngstroms. Analysis of this large and tunable gap renormalization with image-charge calculations based on atomic charges obtained from density functional theory confirms and clarifies the dominant role of image-charge effects in single-molecule junctions.

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Section: Dft Calculationssupporting

confidence: 89%

Large tunable image-charge effects in single-molecule junctions

et al. 2013

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“…III B so that the self-energy r (z) can be calculated iteratively by the Dyson equation [Eq. (27)]. The proof for the left lead runs completely analogously.…”

Section: Appendix D: Self-energy Of a One-dimensional Leadmentioning

confidence: 80%

“…(30), where the self-energies l and r are now obtained from the Dyson equations, Eqs. (26) and (27), but with the energies shifted by the electrostatic shifts…”

Section: B Supercell Approachmentioning

confidence: 99%

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Critical comparison of electrode models in density functional theory based quantum transport calculations

Jacob

Palacios

2011

The Journal of Chemical Physics

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We study the performance of two different electrode models in quantum transport calculations based on density functional theory: parametrized Bethe lattices and quasi-one-dimensional wires or nanowires. A detailed account of implementation details in both the cases is given. From the systematic study of nanocontacts made of representative metallic elements, we can conclude that the parametrized electrode models represent an excellent compromise between computational cost and electronic structure definition as long as the aim is to compare with experiments where the precise atomic structure of the electrodes is not relevant or defined with precision. The results obtained using parametrized Bethe lattices are essentially similar to the ones obtained with quasi-one-dimensional electrodes for large enough cross-sections of these, adding a natural smearing to the transmission curves that mimics the true nature of polycrystalline electrodes. The latter are more demanding from the computational point of view, but present the advantage of expanding the range of applicability of transport calculations to situations where the electrodes have a well-defined atomic structure, as is the case for carbon nanotubes, graphene nanoribbons, or semiconducting nanowires. All the analysis is done with the help of codes developed by the authors which can be found in the quantum transport toolbox ALACANT and are publicly available.

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“…reason, the LS equation is utilized in the implementation of self-consistent calculations for the convergence of electronic states in infinitely open systems [4][5][6][7][8]. In the conventional LS equation method, scattering wave functions are expressed in the Laue representation; that is, the LS equation is solved by using a two-dimensional plane-wave expansion in the directions parallel to the electrode surface (lateral directions) and a real-space discretization of the coordinate in the direction perpendicular to that (longitudinal direction).…”

mentioning

confidence: 99%

First-principles calculation method for electron transport based on the grid Lippmann-Schwinger equation

et al. 2015

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We develop a first-principles electron-transport simulator based on the Lippmann-Schwinger (LS) equation within the framework of the real-space finite-difference scheme. In our fully real-space-based LS (grid LS) method, the ratio expression technique for the scattering wave functions and the Green's function elements of the reference system is employed to avoid numerical collapse. Furthermore, we present analytical expressions and/or prominent calculation procedures for the retarded Green's function, which are utilized in the grid LS approach. In order to demonstrate the performance of the grid LS method, we simulate the electron-transport properties of the semiconductor-oxide interfaces sandwiched between semi-infinite jellium electrodes. The results confirm that the leakage current through the (001)Si-SiO 2 model becomes much larger when the dangling-bond state is induced by a defect in the oxygen layer, while that through the (001)Ge-GeO 2 model is insensitive to the dangling bond state.

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Theoretical investigation on electron transport through an organic molecule: Effect of the contact structure

Cited by 63 publications

References 28 publications

Large tunable image-charge effects in single-molecule junctions

Large tunable image-charge effects in single-molecule junctions

Critical comparison of electrode models in density functional theory based quantum transport calculations

First-principles calculation method for electron transport based on the grid Lippmann-Schwinger equation

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