Thermoelectric properties of B12N12 molecule

2019 ◽  
Vol 16 ◽  
Author(s):  
Mohammad Reza Niazian ◽  
Laleh Farhang Matin ◽  
Mojtaba Yaghobi ◽  
Amir Ali Masoudi
Keyword(s):  
Molecular Electronics ◽  
Thermoelectric Properties ◽  
Electronic Devices ◽  
Thermal Conductance ◽  
Wide Band ◽  
Oscillatory Behavior ◽  
Mapping Technique ◽  
Junction Points ◽  
Inelastic Behaviour ◽  
New Generation

Background: Recently, molecular electronics have attracted the attention of many researchers, both theoretically and applied electronics.Nanostructures have significant thermal properties, which is why they are considered as good options for designing a new generation of integrated electronic devices. Objective: In this paper, the focus is on the thermoelectric properties of the molecular junction points with the electrodes. Also, the influence of the number of atom contacts was investigated on the thermoelectric properties of molecule located between two electrodes metallic.Therefore, the thermoelectric characteristics of the B12 N12 molecule are investigated. Methods: For this purpose, the Green’s function theory as well as mapping technique approach with the wide-band approximation and also the inelastic behaviour is considered for the electron-phonon interactions. Results & Conclusion: Results & Conclusion:It is observed that the largest values of the total part of conductance as well as its elastic (G(e,n)max) depends on the number of atom contacts and are arranged as: G(e,1)max>G(e,4)max>G(e,6)max. Furthermore, the largest values of the electronic thermal conductance, i.e. Kpmax is seen to be in the order of K(p,4)max < K(p,1)max < K(p,6)max that the number of main peaks increases in four-atom contacts at (E<Ef). Furthermore, it is represented that the thermal conductance shows an oscillatory behavior which is significantly affected by the number of atom contacts.

scholarly journals Anchoring Groups Determine Conductance, Thermopower and Thermoelectric Figure of Merit of an Organic Molecular Junction

2021 ◽  
Vol 9 ◽  
Author(s):  
Saeideh Ramezani Akbarabadi ◽  
Mojtaba Madadi Asl
Keyword(s):  
Thermoelectric Properties ◽  
Figure Of Merit ◽  
Electrical Conductance ◽  
Thermal Conductance ◽  
Wide Band ◽  
Transmission Probability ◽  
Molecular Junctions ◽  
Side Group ◽  
Group Position ◽  
Anchoring Groups

Transport properties of molecular junctions are prone to chemical or conformational modifications. Perturbation of the molecule-electrode coupling with anchoring groups or functionalization of the molecule with side groups is a well-characterized method to modulate the thermoelectric properties of molecular junctions. In this study, we used wide-band approximation combined with the non-equilibrium Green’s function (NEGF) formalism to inspect conductance, thermopower and figure of merit of an anthracene molecule coupled to gold (Au) electrodes. To provide a comparative study, three different anchoring groups were used, i.e., thiol, isocyanide and cyanide. The molecule was then perturbed with the amine side group in two positions to explore the interplay between anchoring groups and the side group. We showed that the introduction of side group alters transmission probability near the Fermi energy where transmission peaks are shifted relative to the Fermi level compared to the unperturbed molecule (i.e., without side group), ultimately leading to modified electrical and thermoelectric properties. The greatest value of electrical conductance was achieved when the side-group-perturbed molecule was anchored with isocyanide, whereas the thiol-terminated molecule perturbed with the side group yielded the greatest value of thermal conductance. We found that the Wiedemann-Franz law is violated in the Au-anthracene-Au device. Furthermore, the highest thermopower and figure of merit were attained in the cyanide-terminated perturbed molecule. Our results indicate that charge donating/accepting character of the anchoring group and its interplay with the side group position can modify temperature dependency of conductance, thermopower and figure of merit which is in agreement with experimental findings in organic molecular junctions. Such modifications may potentially contribute to the understanding of emerging conductance-based memory devices designed to mimic the behavior of brain-like synapses.

Two-dimensional wide band-gap nitride semiconductor GaN and AlN materials：properties, fabrication and applications

2021 ◽  
Author(s):  
Zhongxin Wang ◽  
Guodong Wang ◽  
Xintong Liu ◽  
Shouzhi Wang ◽  
Tailin Wang ◽  
...  
Keyword(s):  
Gallium Nitride ◽  
Band Gap ◽  
Hot Spot ◽  
Wide Band ◽  
Aluminium Nitride ◽  
Semiconductor Materials ◽  
Two Dimensional ◽  
Wide Band Gap ◽  
Nitride Semiconductor ◽  
New Generation

Gallium nitride (GaN) and aluminium nitride (AlN), as the representatives of new generation of wide band gap semiconductor materials, have become a hot spot in the semiconductor field due to...

Neural network representation and optimization of thermoelectric states of multiple interacting quantum dots

2020 ◽  
Vol 22 (28) ◽  
pp. 16165-16173
Author(s):  
Hangbo Zhou ◽  
Gang Zhang ◽  
Yong-Wei Zhang
Keyword(s):  
Neural Network ◽  
Machine Learning ◽  
Quantum Dots ◽  
Seebeck Coefficient ◽  
Master Equation ◽  
Thermoelectric Properties ◽  
Electrical Conductance ◽  
Thermal Conductance ◽  
Quantum Master Equation ◽  
Network Representation

We perform quantum master equation calculations and machine learning to investigate the thermoelectric properties of multiple interacting quantum dots, including electrical conductance, Seebeck coefficient, thermal conductance and ZT.

scholarly journals Nanofabrication Techniques in Large-Area Molecular Electronic Devices

2020 ◽  
Vol 10 (17) ◽  
pp. 6064
Author(s):  
Lucía Herrer ◽  
Santiago Martín ◽  
Pilar Cea
Keyword(s):  
Molecular Electronics ◽  
Global Economy ◽  
Electronic Devices ◽  
Functional Materials ◽  
Large Area ◽  
Molecular Electronic ◽  
Hybrid Technology ◽  
Top Contact ◽  
Silicon Based ◽  
Molecular Electronic Devices

The societal impact of the electronics industry is enormous—not to mention how this industry impinges on the global economy. The foreseen limits of the current technology—technical, economic, and sustainability issues—open the door to the search for successor technologies. In this context, molecular electronics has emerged as a promising candidate that, at least in the short-term, will not likely replace our silicon-based electronics, but improve its performance through a nascent hybrid technology. Such technology will take advantage of both the small dimensions of the molecules and new functionalities resulting from the quantum effects that govern the properties at the molecular scale. An optimization of interface engineering and integration of molecules to form densely integrated individually addressable arrays of molecules are two crucial aspects in the molecular electronics field. These challenges should be met to establish the bridge between organic functional materials and hard electronics required for the incorporation of such hybrid technology in the market. In this review, the most advanced methods for fabricating large-area molecular electronic devices are presented, highlighting their advantages and limitations. Special emphasis is focused on bottom-up methodologies for the fabrication of well-ordered and tightly-packed monolayers onto the bottom electrode, followed by a description of the top-contact deposition methods so far used.

scholarly journals High thermal conductive copper/diamond composites: state of the art

2020 ◽  
Vol 56 (3) ◽  
pp. 2241-2274
Author(s):  
S. Q. Jia ◽  
F. Yang
Keyword(s):  
Thermal Conductivity ◽  
Electronic Devices ◽  
Thermal Conductance ◽  
High Thermal Conductivity ◽  
Power Electronic ◽  
Practical Application ◽  
Boundary Area ◽  
Interface Characteristics ◽  
Composite Interface ◽  
Interface Thermal Conductance

Abstract Copper/diamond composites have drawn lots of attention in the last few decades, due to its potential high thermal conductivity and promising applications in high-power electronic devices. However, the bottlenecks for their practical application are high manufacturing/machining cost and uncontrollable thermal performance affected by the interface characteristics, and the interface thermal conductance mechanisms are still unclear. In this paper, we reviewed the recent research works carried out on this topic, and this primarily includes (1) evaluating the commonly acknowledged principles for acquiring high thermal conductivity of copper/diamond composites that are produced by different processing methods; (2) addressing the factors that influence the thermal conductivity of copper/diamond composites; and (3) elaborating the interface thermal conductance problem to increase the understanding of thermal transferring mechanisms in the boundary area and provide necessary guidance for future designing the composite interface structure. The links between the composite’s interface thermal conductance and thermal conductivity, which are built quantitatively via the developed models, were also reviewed in the last part.

The WS2 dependence on the elasticity and optical band gap energies of swollen PAAm composites

2020 ◽  
Vol 55 (1) ◽  
pp. 71-76
Author(s):  
Gülşen Akın Evingür ◽  
Nafia Alara Sağlam ◽  
Büşra Çimen ◽  
Bengü Özuğur Uysal ◽  
Önder Pekcan
Keyword(s):  
Optical Properties ◽  
Band Gap ◽  
Polymer Composites ◽  
Optical Band Gap ◽  
Electronic Devices ◽  
Band Gap Energy ◽  
Tungsten Disulfide ◽  
High Electron ◽  
New Generation ◽  
Doped Polymer

New generation nano-filler polymer composites have many applications including biomedical, electronic and maritime related applications because of their mechanical, electronic and optical properties. The properties of composites were investigated as a function of nano-filler content. Among these, tungsten disulfide (WS2) has the potential to be used as a component in electronic devices owing to its high electron mobility and easily tunable optical band gap energy. Tungsten disulfide (WS2)- Polyacrylamide (PAAm) composite was prepared using free radical co-polymerization and wet laboratory methods with WS2 content. Composites were characterized for mechanical and optical properties using an Elasticity Instrument and UV-vis Spectrophotometer, respectively. Elastic modulus was modeled by a statistical thermodynamics model. Tauc’s and Urbach’s Tail model for direct transition were used to model for the optical band gap. In this study, the swelling and WS2 effect on the optical band gap and elasticity of WS2 - PAAm composites were investigated. It was observed that the elasticity presented a reversed behavior of optical band gap energies with respect to WS2 content. For the applications of nano-filler doped polymer composites in flexible electronic devices, WS2 content strongly influences the mechanical and optical properties.

scholarly journals The Impact of Interfacial Charge Trapping on the Reproducibility of Measurements of Silicon Carbide MOSFET Device Parameters

Crystals ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1143
Author(s):  
Maximilian W. Feil ◽  
Andreas Huerner ◽  
Katja Puschkarsky ◽  
Christian Schleich ◽  
Thomas Aichinger ◽  
...  
Keyword(s):  
Silicon Carbide ◽  
Threshold Voltage ◽  
Thermal Conductance ◽  
Charge Trapping ◽  
Wide Band ◽  
Breakdown Field ◽  
Parameter Determination ◽  
Device Parameter ◽  
Measurement Delay ◽  
The Impact

Silicon carbide is an emerging material in the field of wide band gap semiconductor devices. Due to its high critical breakdown field and high thermal conductance, silicon carbide MOSFET devices are predestined for high-power applications. The concentration of defects with short capture and emission time constants is higher than in silicon technologies by orders of magnitude which introduces threshold voltage dynamics in the volt regime even on very short time scales. Measurements are heavily affected by timing of readouts and the applied gate voltage before and during the measurement. As a consequence, device parameter determination is not as reproducible as in the case of silicon technologies. Consequent challenges for engineers and researchers to measure device parameters have to be evaluated. In this study, we show how the threshold voltage of planar and trench silicon carbide MOSFET devices of several manufacturers react on short gate pulses of different lengths and voltages and how they influence the outcome of application-relevant pulsed current-voltage characteristics. Measurements are performed via a feedback loop allowing in-situ tracking of the threshold voltage with a measurement delay time of only 1 μs. Device preconditioning, recently suggested to enable reproducible BTI measurements, is investigated in the context of device parameter determination by varying the voltage and the length of the preconditioning pulse.

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