Electron transport analysis in positional isomers - A DFT-NEGF approach

Aadhityan, A.; Kala, C. Preferencial; Thiruvadigal, D. John

doi:10.1016/j.mssp.2019.104654

Cited by 5 publications

(6 citation statements)

References 38 publications

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“…Single molecule junctions are the simplest devices for exploring the properties of single molecule electronics both experimentally and theoretically, with many examples in the literature. 22 − 27 …”

Section: Introductionmentioning

confidence: 99%

“…In this work, the transport properties of a specific tungsten-based POM molecule, [W 18 O 54 (SO 3 ) 2 ] 4– , are explored theoretically by computational modeling of POM molecular junctions. Single molecule junctions are the simplest devices for exploring the properties of single molecule electronics both experimentally and theoretically, with many examples in the literature. − …”

Section: Introductionmentioning

confidence: 99%

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Influence of the Contact Geometry and Counterions on the Current Flow and Charge Transfer in Polyoxometalate Molecular Junctions: A Density Functional Theory Study

et al. 2021

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Polyoxometalates (POMs) are promising candidates for molecular electronic applications because (1) they are inorganic molecules, which have better CMOS compatibility compared to organic molecules; (2) they are easily synthesized in a one-pot reaction from metal oxides (MO x ) (where the metal M can be, e.g., W, V, or Mo, and x is an integer between 4 and 7); (3) POMs can self-assemble to form various shapes and configurations, and thus the chemical synthesis can be tailored for specific device performance; and (4) they are redox-active with multiple states that have a very low voltage switching between polarized states. However, a deep understanding is required if we are to make commercial molecular devices a reality. Simulation and modeling are the most time efficient and cost-effective methods to evaluate a potential device performance. Here, we use density functional theory in combination with nonequilibrium Green’s function to study the transport properties of [W 18 O 54 (SO 3 ) 2 ] 4– , a POM cluster, in a variety of molecular junction configurations. Our calculations reveal that the transport profile not only is linked to the electronic structure of the molecule but also is influenced by contact geometry and presence of ions. More specifically, the contact geometry and the number of bonds between the POM and the electrodes determine the current flow. Hence, strong and reproducible contact between the leads and the molecule is mandatory to establish a reliable fabrication process. Moreover, although often ignored, our simulations show that the charge balancing counterions activate the conductance channels intrinsic to the molecule, leading to a dramatic increase in the computed current at low bias. Therefore, the role of these counterions cannot be ignored when molecular based devices are fabricated. In summary, this work shows that the current transport in POM junctions is determined by not only the contact geometry between the molecule and the electrode but also the presence of ions around the molecule. This significantly impacts the transport properties in such nanoscale molecular electronic devices.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Influence of the Contact Geometry and Counterions on the Current Flow and Charge Transfer in Polyoxometalate Molecular Junctions: A Density Functional Theory Study

et al. 2021

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“…The energy band structure, band angle, and gap variation in the gap are found to be functions of ζ and bending angle. The loss in trans conductance in A(6,6) and A (8,8), can be explained at the high value of 𝜁 = 0.1 and high, deformation induces gap opening i.e. splitting of band in high energy region as a result conductance decreases, so we can use to design pressure sensors, as well as nano resistors for flexible circuits by changing the morphology of plane/surface.…”

Section: Discussionmentioning

confidence: 99%

“…Here we consider CNTs as elastic tubes and having overall length less than 100 nm, which have been frequently used to study the behavior of nanostructures effectively, and Eringen's nonlocal continuum models [9] for CNT's. Here in present case, we used Eringen's nonlocal constitutive equations and applied the results to calculate the effect of bending curvature using the nonlinear dynamics [8][9][10]. Due to bending effect the lattice space among different atoms changes (here increased) (in algorithm design and due to constraint the length of simulated structure is less than 100 nm), and as a result the discrete nature of material is managed and it is no longer be normalized into a continuum model.…”

Section: Methodsmentioning

confidence: 99%

“…The energy band gaps were calculated and transmission spectrum is obtained as shown in figure2. For our work we used four different sizes CNT's which represented by general notation Z(10,0), Z(5,0), A(6,6), and A(8,8). The tube diameter for the native (D0) and the deformed SWCNTs (Dd) because of applied strain as well as their corresponding degree of deformation 𝜁 are shown in Table1…”

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confidence: 99%

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Tailoring Electrical Properties of SWCNT’s by Deformation Method

Lamba

Kassa

Brar

2023

Preprint

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For more efficient energy distribution system, we need a high efficiency material for charge transport. In present work we combined continuum mechanics methods for studying the effect of strain on CNT, and the change in electrical parameters as a result of CNT deformation using first principal method. We found that on applying stress on SWCNT’s, the bond lengths increase near the point of applied force from 1.42 to 1.88Å (just below the applied force and on opposite face it changes from 1.42 to 2.24 Å), and at the edged region, the bond length decreases from 1.42 to 1.28 on both side. Further there is decrease in trans conductance in A (6,6) and A(8,8), due to induces gap opening i.e. splitting of band in high energy region

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