scholarly journals Oscillating Seebeck coefficients in π-stacked molecular junctions

RSC Advances ◽  
2018 ◽  
Vol 8 (44) ◽  
pp. 24711-24715 ◽  
Author(s):  
Mohsin K. Al-Khaykanee ◽  
Ali K. Ismael ◽  
Iain Grace ◽  
Colin J. Lambert
Keyword(s):  
Seebeck Coefficient ◽  
Quantum Interference ◽  
Molecular Junctions ◽  
Seebeck Coefficients

When two adjacent molecules are slid across each other, quantum interference causes oscillations in their conductance and Seebeck coefficient.

scholarly journals Connectivity-driven bi-thermoelectricity in heteroatom-substituted molecular junctions

2018 ◽  
Vol 20 (14) ◽  
pp. 9630-9637 ◽  
Author(s):  
Sara Sangtarash ◽  
Hatef Sadeghi ◽  
Colin J. Lambert
Keyword(s):  
Seebeck Coefficient ◽  
Quantum Interference ◽  
Molecular Junctions ◽  
Thermoelectric Performance ◽  
Polyaromatic Hydrocarbon ◽  
Heteroatom Substitution ◽  
New Strategy

To improve the thermoelectric performance of molecular junctions formed by polyaromatic hydrocarbon (PAH) cores, we present a new strategy for enhancing their Seebeck coefficient by utilizing connectivities with destructive quantum interference combined with heteroatom substitution.

High tunneling magnetoresistance induced by symmetry and quantum interference in magnetic molecular junctions

2021 ◽  
Author(s):  
Lin Huang ◽  
Yu-Jia Zeng ◽  
Dan Wu ◽  
Nan-Nan Luo ◽  
Ye-Xin Feng ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Green’S Function ◽  
Green's Function ◽  
Quantum Interference ◽  
Density Functional ◽  
Molecular Junctions ◽  
Tunneling Magnetoresistance ◽  
Functional Theory ◽  
Nonequilibrium Green's Function ◽  
Molecular Scale

Achieving high tunneling magnetoresistance (TMR) in molecular-scale junctions is attractive for their applications in spintronics. By using density-functional theory (DFT) in combination with the nonequilibrium Green's function (NEGF) method, we...

scholarly journals Heteroatom Effects on Quantum Interference in Molecular Junctions: Modulating Antiresonances by Molecular Design

2021 ◽  
Author(s):  
Luke J. O’Driscoll ◽  
Sara Sangtarash ◽  
Wei Xu ◽  
Abdalghani Daaoub ◽  
Wenjing Hong ◽  
...  
Keyword(s):  
Quantum Interference ◽  
Molecular Design ◽  
Molecular Junctions

DIELECTRIC CONSTANT AND SEEBECK COEFFICIENT FOR SEMICONDUCTORS: THERMODYNAMIC AND DFT STUDIES

2013 ◽  
Vol 12 (06) ◽  
pp. 1350057 ◽  
Author(s):  
HSIU-YA TASI ◽  
CHAOYUAN ZHU
Keyword(s):  
Boundary Condition ◽  
Dielectric Constant ◽  
Seebeck Coefficient ◽  
Gas Phase ◽  
Present Method ◽  
Dielectric Constants ◽  
Semiconductor Materials ◽  
Electronic Polarizability ◽  
Seebeck Coefficients ◽  
Good Agreement

Dielectric constants and Seebeck coefficients for semiconductor materials are studied by thermodynamic method plus ab initio quantum density functional theory (DFT). A single molecule which is formed in semiconductor material is treated in gas phase with molecular boundary condition and then electronic polarizability is directly calculated through Mulliken and atomic polar tensor (APT) density charges in the presence of the external electric field. This electronic polarizability can be converted to dielectric constant for solid material through the Clausius–Mossotti formula. Seebeck coefficient is first simulated in gas phase by thermodynamic method and then its value divided by its dielectric constant is regarded as Seebeck coefficient for solid materials. Furthermore, unit cell of semiconductor material is calculated with periodic boundary condition and its solid structure properties such as lattice constant and band gap are obtained. In this way, proper DFT function and basis set are selected to simulate electronic polarizability directly and Seebeck coefficient through chemical potential. Three semiconductor materials Mg 2 Si , β- FeSi 2 and SiGe are extensively tested by DFT method with B3LYP, BLYP and M05 functionals, and dielectric constants simulated by the present method are in good agreement with experimental values. Seebeck coefficients simulated by the present method are in reasonable good agreement with experiments and temperature dependence of Seebeck coefficients basically follows experimental results as well. The present method works much better than the conventional energy band structure theory for Seebeck coefficients of three semiconductors mentioned above. Simulation with periodic boundary condition can be generalized directly to treat with doped semiconductor in near future.

scholarly journals Inelastic electron tunneling spectroscopy in molecular junctions showing quantum interference

2017 ◽  
Vol 95 (16) ◽  
Author(s):  
C. Salhani ◽  
M. L. Della Rocca ◽  
C. Bessis ◽  
R. Bonnet ◽  
C. Barraud ◽  
...  
Keyword(s):  
Quantum Interference ◽  
Electron Tunneling ◽  
Tunneling Spectroscopy ◽  
Molecular Junctions ◽  
Inelastic Electron ◽  
Inelastic Electron Tunneling Spectroscopy ◽  
Inelastic Electron Tunneling ◽  
Electron Tunneling Spectroscopy

scholarly journals Identification of a positive-Seebeck-coefficient exohedral fullerene

Nanoscale ◽  
2016 ◽  
Vol 8 (28) ◽  
pp. 13597-13602 ◽  
Author(s):  
Nasser Almutlaq ◽  
Qusiy Al-Galiby ◽  
Steven Bailey ◽  
Colin J. Lambert
Keyword(s):  
Seebeck Coefficient ◽  
Seebeck Coefficients

If fullerene-based thermoelectricity is to become a viable technology, then fullerenes exhibiting both positive and negative Seebeck coefficients are needed.

Switchable Spin Filters in Magnetic Molecular Junctions Based on Quantum Interference

2020 ◽  
Vol 6 (12) ◽  
pp. 2000689
Author(s):  
Lin Huang ◽  
Shi‐Zhang Chen ◽  
Yu‐Jia Zeng ◽  
Dan Wu ◽  
Bo‐Lin Li ◽  
...  
Keyword(s):  
Quantum Interference ◽  
Molecular Junctions ◽  
Spin Filters

Quantum Interference Enhanced Thermoelectricity in Ferrocene Based Molecular Junctions

2019 ◽  
Vol 19 (11) ◽  
pp. 7452-7455
Author(s):  
Ashkan Vakilipour Takaloo ◽  
Hatef Sadeghi
Keyword(s):  
Seebeck Coefficient ◽  
Single Molecule ◽  
Power Factor ◽  
Quantum Interference ◽  
Room Temperature ◽  
Thermoelectric Power Factor ◽  
Molecular Scale ◽  
Single Molecule Junctions ◽  
Path Structure ◽  
Single Path

Recent experimental indications of room-temperature quantum interference in the sub-nanometer single molecules suggest that such effects could be utilized to engineer thermoelectric properties of organic single molecule junctions. In this paper, we show that the thermoelectric power factor is significantly enhanced in double path ferrocene cycles compared to the single path counterpart. Due to quantum interference in the double path structure, the Seebeck coefficient is significantly enhanced while the conductance is less affected compared to single path structure. The power factor of the ferrocene cycles are 1–2 orders of magnitude higher than the best organic material reported today. This opens new avenues for future molecular scale organometallic thermoelectricity.

Critical role of nanoinclusions in silver selenide nanocomposites as a promising room temperature thermoelectric material

2019 ◽  
Vol 7 (9) ◽  
pp. 2646-2652 ◽  
Author(s):  
Khak Ho Lim ◽  
Ka Wai Wong ◽  
Yu Liu ◽  
Yu Zhang ◽  
Doris Cadavid ◽  
...  
Keyword(s):  
Seebeck Coefficient ◽  
Room Temperature ◽  
Opposite Effect ◽  
Critical Role ◽  
Free Carrier ◽  
Silver Selenide ◽  
Band Bending ◽  
Seebeck Coefficients ◽  
Electrical Conductivities

The introduction of nonmetal nanoinclusions within Ag2Se results in an interphase band bending that promotes electron filtering and increase Seebeck coefficient. Similar loading of metal nanoinclusions provided an opposite effect-modulating free carrier concentration, as characterized by superior electrical conductivities and lower Seebeck coefficients.

scholarly journals Annealing Effect on the Thermoelectric Properties of Bi2Te3Thin Films Prepared by Thermal Evaporation Method

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Jyun-Min Lin ◽  
Ying-Chung Chen ◽  
Chi-Pi Lin
Keyword(s):  
Thin Films ◽  
Seebeck Coefficient ◽  
Thermoelectric Properties ◽  
Power Factor ◽  
Room Temperature ◽  
Annealing Temperature ◽  
Thermal Evaporation ◽  
Thermal Evaporation Method ◽  
Si Substrates ◽  
Seebeck Coefficients

Bismuth telluride-based compounds are known to be the best thermoelectric materials within room temperature region, which exhibit potential applications in cooler or power generation. In this paper, thermal evaporation processes were adopted to fabricate the n-type Bi2Te3thin films on SiO2/Si substrates. The influence of thermal annealing on the microstructures and thermoelectric properties of Bi2Te3thin films was investigated in temperature range 100–250°C. The crystalline structures and morphologies were characterized by X-ray diffraction and field emission scanning electron microscope analyses. The Seebeck coefficients, electrical conductivity, and power factor were measured at room temperature. The experimental results showed that both the Seebeck coefficient and power factor were enhanced as the annealing temperature increased. When the annealing temperature increased to 250°C for 30 min, the Seebeck coefficient and power factor of n-type Bi2Te3-based thin films were found to be about −132.02 μV/K and 6.05 μW/cm·K2, respectively.

Sign in / Sign up

Export Citation Format

Share Document