Tuning the thermoelectric properties of a single-molecule junction by mechanical stretching

2015 ◽  
Vol 17 (7) ◽  
pp. 5386-5392 ◽  
Author(s):  
Alberto Torres ◽  
Renato B. Pontes ◽  
Antônio J. R. da Silva ◽  
Adalberto Fazzio
Keyword(s):  
Seebeck Coefficient ◽  
Thermoelectric Properties ◽  
Single Molecule ◽  
Figure Of Merit ◽  
Room Temperature ◽  
Heat Conductance ◽  
Molecule Junction ◽  
Electronic Heat ◽  
Single Molecule Junction ◽  
Mechanical Stretching

We theoretically investigate, as a function of the stretching, the behaviour of the Seebeck coefficient, the electronic heat conductance and the figure of merit of a molecule-based junction composed of a benzene-1,4-dithiolate (BDT) molecule coupled to Au(111) surfaces at room temperature.

The Influence of Silicon Dopant and Processing on Thermoelectric Properties of B4C Ceramics

1998 ◽  
Vol 545 ◽  
Author(s):  
Ke-Feng Cai ◽  
Ce-Wen Nan ◽  
Xin-Min Min
Keyword(s):  
Electrical Conductivity ◽  
Seebeck Coefficient ◽  
Thermoelectric Properties ◽  
Hot Pressing ◽  
Figure Of Merit ◽  
Room Temperature ◽  
A Value ◽  
Si Doped

AbstractB4C ceramics doped with various content of Si (0 to 2.03 at%) are prepared via hot pressing. The composition and microstructure of the ceramics are characterized by means of XRD and EPMA. Their electrical conductivity and Seebeck coefficient of the samples are measured from room temperature up to 1500K. The electrical conductivity increases with temperature, and more rapidly after 1300K; the Seebeck coefficient of the ceramics also increases with temperature and rises to a value of about 320μVK−1. The value of the figure of merit of Si-doped B4C rises to about 4 × 10−4K−1 at 1500K.

scholarly journals Stretching-Dependent Thermoelectric Properties of a BDT Single-Molecule Junction

2015 ◽  
Vol 9 (18) ◽  
pp. 298-300
Author(s):  
Renato B. Pontes ◽  
Alberto Torres ◽  
Antônio J. R. da Silva ◽  
Adalberto Fazzio
Keyword(s):  
Thermoelectric Properties ◽  
Single Molecule ◽  
Molecule Junction ◽  
Single Molecule Junction

scholarly journals Long-lived charged states of single porphyrin-tape junctions under ambient conditions

2021 ◽  
Vol 6 (1) ◽  
pp. 49-58
Author(s):  
Edmund Leary ◽  
Georg Kastlunger ◽  
Bart Limburg ◽  
Laura Rincón-García ◽  
Juan Hurtado-Gallego ◽  
...  
Keyword(s):  
Charge State ◽  
Molecular Electronics ◽  
Single Molecule ◽  
Room Temperature ◽  
Ambient Conditions ◽  
Molecular Memory ◽  
Molecule Junction ◽  
Single Molecule Junction

Controlling the charge state of a molecule wired in a two-terminal single-molecule junction at room temperature is a key challenge in molecular electronics in relation to the development of molecular memory and other computational componentry.

scholarly journals Side-group-mediated thermoelectric properties of anthracene single-molecule junction with anchoring groups

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Saeideh Ramezani Akbarabadi ◽  
Hamid Rahimpour Soleimani ◽  
Maysam Bagheri Tagani
Keyword(s):  
Thermoelectric Properties ◽  
Single Molecule ◽  
Figure Of Merit ◽  
Density Functional ◽  
Side Group ◽  
Thermoelectric Efficiency ◽  
Group Position ◽  
Single Molecule Junctions ◽  
Molecule Junction ◽  
Anchoring Groups

AbstractCharge transfer characteristics of single-molecule junctions at the nanoscale, and consequently, their thermoelectric properties can be dramatically tuned by chemical or conformational modification of side groups or anchoring groups. In this study, we used density functional theory (DFT) combined with the non-equilibrium Green’s function (NEGF) formalism in the linear response regime to examine the thermoelectric properties of a side-group-mediated anthracene molecule coupled to gold (Au) electrodes via anchoring groups. In order to provide a comparative inspection three different side groups, i.e. amine, nitro and methyl, in two different positions were considered for the functionalization of the molecule terminated with thiol or isocyanide anchoring groups. We showed that when the anchored molecule is perturbed with side group, the peaks of the transmission spectrum were shifted relative to the Fermi energy in comparison to the unperturbed molecule (i.e. without side group) leading to modified thermoelectric properties of the system. Particularly, in the thiol-terminated molecule the amine side group showed the greatest figure of merit in both positions which was suppressed by the change of side group position. However, in the isocyanide-terminated molecule the methyl side group attained the greatest thermoelectric efficiency where its magnitude was relatively robust to the change of side group position. In this way, different combinations of side groups and anchoring groups can improve or suppress thermopower and the figure of merit of the molecular junction depending on the interplay between charge donating/accepting nature of the functionals or their position.

High Thermoelectric Performance of p-Type Bi0.5Sb1.5Te3+xTe Crystals Prepared via Gradient Freezing

2012 ◽  
Vol 621 ◽  
pp. 167-171
Author(s):  
Tao Hua Liang ◽  
Shi Qing Yang ◽  
Zhi Chen ◽  
Qing Xue Yang
Keyword(s):  
Thermal Conductivity ◽  
Seebeck Coefficient ◽  
Carrier Concentration ◽  
Thermoelectric Properties ◽  
Figure Of Merit ◽  
Room Temperature ◽  
Thermoelectric Performance ◽  
Thermoelectric Figure Of Merit ◽  
Thermoelectric Figure ◽  
P Type

p-type Bi0.5Sb1.5Te3+xTe thermoelectric crystals with various percentages of Te (x = 0.00 wt.%–3.00 wt.%) excess were prepared by the gradient freeze method. By doping with different Te contents, anti-site defects, Te vacancies and hole carrier concentrations were controlled. The Seebeck coefficient, resistivity, thermal conductivity, carrier concentration, and mobility were measured. The relationships between the Te content and thermoelectric properties were investigated in detail. The results suggested that the thermoelectric figure of merit ZT of the Bi0.5Sb1.5Te3+0.09wt.% crystals was 1.36 near room temperature, the optimum carrier concentration was 1.25 × 1019 cm-3, and the mobility was 1480 cm2 V-1 S-1, respectively.

scholarly journals Charge transport in a zinc–porphyrin single-molecule junction

2011 ◽  
Vol 2 ◽  
pp. 714-719 ◽  
Author(s):  
Mickael L Perrin ◽  
Christian A Martin ◽  
Ferry Prins ◽  
Ahson J Shaikh ◽  
Rienk Eelkema ◽  
...  
Keyword(s):  
Charge Transport ◽  
Single Molecule ◽  
Room Temperature ◽  
Complex Molecule ◽  
Observable Effect ◽  
Detailed Characterization ◽  
Current Voltage ◽  
Molecule Junction ◽  
Single Molecule Junction

We have investigated charge transport in ZnTPPdT–Pyr (TPPdT: 5,15-di(p-thiolphenyl)-10,20-di(p-tolyl)porphyrin) molecular junctions using the lithographic mechanically controllable break-junction (MCBJ) technique at room temperature and cryogenic temperature (6 K). We combined low-bias statistical measurements with spectroscopy of the molecular levels in the form of I(V) characteristics. This combination allows us to characterize the transport in a molecular junction in detail. This complex molecule can form different junction configurations, having an observable effect on the trace histograms and the current–voltage (I(V)) measurements. Both methods show that multiple, stable single-molecule junction configurations can be obtained by modulating the interelectrode distance. In addition we demonstrate that different ZnTPPdT–Pyr junction configurations can lead to completely different spectroscopic features with the same conductance values. We show that statistical low-bias conductance measurements should be interpreted with care, and that the combination with I(V) spectroscopy represents an essential tool for a more detailed characterization of the charge transport in a single molecule.

Thermoelectric Properties of Tl-X-Te (X=Pb, Sn, Ge) Systems

2005 ◽  
Vol 886 ◽  
Author(s):  
Atsuko Kosuga ◽  
Ken Kurosaki ◽  
Hiroaki Muta ◽  
Shinsuke Yamanaka
Keyword(s):  
Thermal Conductivity ◽  
Electrical Resistivity ◽  
Solid State ◽  
Electrical Properties ◽  
Seebeck Coefficient ◽  
Thermoelectric Properties ◽  
Figure Of Merit ◽  
Room Temperature ◽  
Lattice Thermal Conductivity ◽  
Dimensionless Figure Of Merit

ABSTRACTPolycrystalline-sintered samples of Tl2GeTe3, Tl4SnTe3, and Tl4PbTe3 were prepared by a solid-state reaction. Their thermoelectric properties were evaluated at temperatures ranging from room temperature to ca. 700 K by using the measured electrical resistivity (ρ), Seebeck coefficient (S), and thermal conductivity (κ). Despite their poor electrical properties, the dimensionless figure of merit ZT of all the compounds was relatively high, i.e., 0.74 at 673 K for Tl4SnTe3, 0.71 at 673 K for Tl4PbTe3, 0.29 at 473 K for Tl2GeTe3, due to the very low lattice thermal conductivity of the compounds.

Mechanically-Tunable Quantum Interference in Ferrocene-Based Single-Molecule Junctions

2020 ◽  
Author(s):  
María Camarasa-Gómez ◽  
Daniel Hernangómez-Pérez ◽  
Michael S. Inkpen ◽  
Giacomo Lovat ◽  
E-Dean Fung ◽  
...  
Keyword(s):  
Single Molecule ◽  
Quantum Interference ◽  
Degrees Of Freedom ◽  
Building Blocks ◽  
Ferrocene Derivative ◽  
Single Molecule Junctions ◽  
Molecule Junction ◽  
Single Molecule Junction ◽  
The Impact ◽  
D Orbitals

Ferrocenes are ubiquitous organometallic building blocks that comprise a Fe atom sandwiched between two cyclopentadienyl (Cp) rings that rotate freely at room temperature. Of widespread interest in fundamental studies and real-world applications, they have also attracted<br>some interest as functional elements of molecular-scale devices. Here we investigate the impact of<br>the configurational degrees of freedom of a ferrocene derivative on its single-molecule junction<br>conductance. Measurements indicate that the conductance of the ferrocene derivative, which is<br>suppressed by two orders of magnitude as compared to a fully conjugated analog, can be modulated<br>by altering the junction configuration. Ab initio transport calculations show that the low conductance is a consequence of destructive quantum interference effects that arise from the hybridization of metal-based d-orbitals and the ligand-based π-system. By rotating the Cp rings, the hybridization, and thus the quantum interference, can be mechanically controlled, resulting in a conductance modulation that is seen experimentally.<br>

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