Conductance of Stretching Oligothiophene Single-Molecule Junctions: A First-Principles Study

Tang, Yingying; Bagci, V. M. K.; Chen, Jinghan; Kaun, Chao-Cheng

doi:10.1021/jp209671v

Cited by 10 publications

(6 citation statements)

References 31 publications

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“…Additionally, in theoretical studies, the interface configurations perform more influence on the electronic transport properties of molecular junctions than in experimental ones 41 42 43 . Hence, when molecular junctions are stretched, steps in conductance traces often as a signature of the molecular junction formed in the experiment are seldom simulated out theoretically 44 45 . In fact, details of the interface configurations are still difficult to control or even detect in the present experiments 46 47 .…”

mentioning

confidence: 99%

A method to study electronic transport properties of molecular junction: one-dimension transmission combined with three-dimension correction approximation (OTCTCA)

Liu

Wang

2016

Sci Rep

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Based on the ab initio calculation, a method of one-dimension transmission combined with three-dimension correction approximation (OTCTCA) is developed to investigate electron-transport properties of molecular junctions. The method considers that the functional molecule provides a spatial distribution of effective potential field for the electronic transport. The electrons are injected from one electrode by bias voltage, then transmit through the potential field around the functional molecule, at last are poured into the other electrode with a specific transmission probability which is calculated from one-dimension Schrödinger equation combined with three-dimension correction. The electron-transport properties of alkane diamines and 4, 4′-bipyridine molecular junctions are studied by applying OTCTCA method. The numerical results show that the conductance obviously exponentially decays with the increase of molecular length. When stretching molecular junctions, steps with a certain width are presented in conductance traces. Especially, in stretching process of 4, 4′-bipyridine molecular junction, if the terminal N atom is broken from flat part of electrode tip and exactly there is a surface Au atom on the tip nearby the N atom, the molecule generally turns to absorb on the surface Au atom, which further results in another lower conductance step in the traces as the experimental probing.

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mentioning

confidence: 99%

A method to study electronic transport properties of molecular junction: one-dimension transmission combined with three-dimension correction approximation (OTCTCA)

Liu

Wang

2016

Sci Rep

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“…The weak coupling constants Γ in S20 and S21 satisfy the assumption of independent channel contributions from each conducting energy level for fitting. 46 In addition, the distinct features of transmission for S20 and S21 suggest that the edge modification not only affects the number of conducting energy levels but also the energy alignment between the related level and E f , 41,48,49 which draws a great deal of attention in the electrodemolecule-electrode junction. For example, the alignment between a conducting state and E f can be controlled by repeated stretching and compressing of single molecule junctions.…”

Section: Junctions With a Large Width Differencementioning

confidence: 99%

“…For example, the alignment between a conducting state and E f can be controlled by repeated stretching and compressing of single molecule junctions. 48,49 Besides, energy alignment under bias can cause negative differential resistance (NDR). 41 To gain insight into the essential channels contributing to the transmission, the dominant transmitting eigenchannels for S20 at E = −0.42 eV and S21 at E f are shown in Fig.…”

Section: Junctions With a Large Width Differencementioning

confidence: 99%

Tailoring the transmission lineshape spectrum of zigzag graphene nanoribbon based heterojunctions via controlling their width and edge protrusions

Dou

Sarkar

et al. 2015

Nanoscale

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We report a first-principles analysis of electron transport through narrow zigzag graphene nanoribbon (up to 2.2 nm) based wedge-shaped heterojunctions. We show that the width difference between the electrode and the scattering region and the edge protrusion of heterojunctions can be tuned to endow the system's transmission spectrum with distinctive features. In particular, transport through junctions with a one sided protrusion in the scattering region is always dominated by a Breit-Wigner-type resonance right at the Fermi level, regardless of the large or small width difference. On the other hand, a junction with protrusions on both sides of the scattering region shows insulating behaviour near the Fermi level for a large width difference but weak transmission channels are formed at the core of the scattering region for a small width difference. When the protrusion is absent in the junction, transmission functions display rather complex structures: double peaks situating nearly symmetrically away from the Fermi level and a strongly asymmetric profile in the vicinity of the Fermi level are observed for large and small width differences, respectively. These results may shed light on the design of real connecting components in nanocircuits.

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“…Due to increasing attention on mechanical control over molecular conductance, 10−12 involving a mechanical stretching process to bridge theoretical calculation and break junction technique is essential for a thoroughly quantitative understanding of the electronic transport properties of singlemolecule junctions. 13 Recently, extensive research has demonstrated that the anchoring group of the central molecule plays a crucial role for charge transfer through single-molecule junctions. 14−16 Thiol is the most frequently applied anchoring group due to strong AuS bond to form a stable molecular junction.…”

Section: ■ Introductionmentioning

confidence: 99%

Strain-Enhanced Spin Injection in Amine-Ended Single-Molecule Magnetic Junctions

Tang

Lin

2015

J. Phys. Chem. C

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The first-principles calculation with the nonequilibrium Green's function formalism is employed to comprehensively demonstrate that the mechanical strain and anchoring group are two crucial impacts on spin transport in single-molecule magnetic junctions. For the dissociated amineended benzene contacted to cobalt electrodes, we present the strain-enhanced spin injection efficiency, including sign reversal and nearly perfect spin injection under junction stretching process. The underlying mechanism is the strain-assisted movement of pronounced and broad spin-up transmission feature toward the Fermi energy. This intriguing finding reveals the superior spin transfer in amine-ended single-molecule magnetic junction, which is in sharp contrast to the better charge transfer between gold electrodes in traditional thiol-ended molecular junctions. Our calculation results may pave the way for promising tunability of spin injection efficiency under mechanical stimulus of break junction technique.

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Conductance of Stretching Oligothiophene Single-Molecule Junctions: A First-Principles Study

Cited by 10 publications

References 31 publications

A method to study electronic transport properties of molecular junction: one-dimension transmission combined with three-dimension correction approximation (OTCTCA)

A method to study electronic transport properties of molecular junction: one-dimension transmission combined with three-dimension correction approximation (OTCTCA)

Tailoring the transmission lineshape spectrum of zigzag graphene nanoribbon based heterojunctions via controlling their width and edge protrusions

Strain-Enhanced Spin Injection in Amine-Ended Single-Molecule Magnetic Junctions

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