Quantization of Electrical and Thermal Conductance in Nanostructures

2019 ◽  
pp. 185-202
Author(s):  
Waldemar Nawrocki
Keyword(s):  
Thermal Conductance

THERMAL CONDUCTANCE OF TWO-SIDED CNT INTERFACES MEASUERED BY A PHOTO ACOUSTIC TECHNIQUE

Equipment ◽  
2006 ◽  
Author(s):  
B. A. Cola ◽  
J. Xu ◽  
C. Cheng ◽  
Xianfan Xu ◽  
T. Fisher
Keyword(s):  
Thermal Conductance ◽  
Acoustic Technique

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 Finite Physical Dimensions Thermodynamics Analysis and Design of Closed Irreversible Cycles

Energies ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3416
Author(s):  
Gheorghe Dumitrașcu ◽  
Michel Feidt ◽  
Ştefan Grigorean
Keyword(s):  
Thermal Conductance ◽  
Heat Output ◽  
Operational Parameters ◽  
Analysis And Design ◽  
The Mean ◽  
Internal Irreversibility ◽  
Heat Transfers ◽  
Operational Constraints ◽  
Log Temperatures ◽  
Physical Dimensions

This paper develops simplifying entropic models of irreversible closed cycles. The entropic models involve the irreversible connections between external and internal main operational parameters with finite physical dimensions. The external parameters are the mean temperatures of external heat reservoirs, the heat transfers thermal conductance, and the heat transfer mean log temperatures differences. The internal involved parameters are the reference entropy of the cycle and the internal irreversibility number. The cycle’s design might use four possible operational constraints in order to find out the reference entropy. The internal irreversibility number allows the evaluation of the reversible heat output function of the reversible heat input. Thus the cycle entropy balance equation to design the trigeneration cycles only through external operational parameters might be involved. In designing trigeneration systems, they must know the requirements of all consumers of the useful energies delivered by the trigeneration system. The conclusions emphasize the complexity in designing and/or optimizing the irreversible trigeneration systems.

scholarly journals Simultaneously controlling heat conduction and infrared absorption with a textured dielectric film to enhance the performance of thermopiles

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Yunqian He ◽  
Yuelin Wang ◽  
Tie Li
Keyword(s):  
Heat Conduction ◽  
Infrared Absorption ◽  
High Performance ◽  
Performance Enhancement ◽  
Dielectric Film ◽  
Great Influence ◽  
Thermal Conductance ◽  
Molding Process ◽  
Absorption Properties

AbstractThe heat conduction and infrared absorption properties of the dielectric film have a great influence on the thermopile performance. Thinning the dielectric film, reducing its contact area with the silicon substrate, or adding high-absorptivity nanomaterials has been proven to be effective in improving thermopiles. However, these methods may result in a decrease in the structural mechanical strength and increases in the fabrication complexity and cost. In this work, a new performance-enhancement strategy for thermopiles by simultaneously controlling the heat conduction and infrared absorption with a TExtured DIelectric (TEDI) film is developed and presented. The TEDI film is formed in situ by a simple hard-molding process that is compatible with the fabrication of traditional thermopiles. Compared to the control FLat DIelectric (FLDI) film, the intrinsic thermal conductance of the TEDI film can be reduced by ~18–30%, while the infrared absorption can be increased by ~7–13%. Correspondingly, the responsivity and detectivity of the fabricated TEDI film-based thermopile can be significantly enhanced by ~38–64%. An optimized TEDI film-based thermopile has achieved a responsivity of 156.89 V·W−1 and a detectivity of 2.16 × 108 cm·Hz1/2·W−1, while the response time constant can remain <12 ms. These results exhibit the great potential of using this strategy to develop high-performance thermopiles and enhance other sensors with heat transfer and/or infrared absorption mechanisms.

scholarly journals Using Amorphous CoB Alloy as Transducer to Detect Acoustic Propagation and Heat Transport at Interface

2021 ◽  
Vol 11 (11) ◽  
pp. 5155
Author(s):  
Liu Jian ◽  
Gyung-Min Choi
Keyword(s):  
Heat Transport ◽  
Sapphire Substrate ◽  
Intermediate Layer ◽  
Thermal Conductance ◽  
Acoustic Oscillation ◽  
Acoustic Propagation ◽  
Acoustic Oscillations ◽  
Interfacial Coupling ◽  
Soft Layer ◽  
Substrate Interface

Acoustic oscillation provides useful information regarding the interfacial coupling between metal transducer layers and substrate materials. The interfacial coupling can be significantly reduced by a mechanically soft layer between the transducer and substrate. However, preserving a thin, soft layer at the interface during fabrication is often challenging. In this study, we demonstrate that an amorphous CoB alloy on top of a sapphire substrate can substantially amplify acoustic oscillations. By analyzing the attenuation of acoustic oscillations, we show that a thin, soft layer with a thickness of >2 ± 1 Å exists at the interface. The intermediate layer at the interface is further verified by investigating heat transport. By analyzing the slow decrease of the temperature of the transducer layer, we determine a thermal conductance of 35 ± 5 MW m−2 K−1 at the transducer/substrate interface. This low value supports the existence of a thin, soft layer at the interface. Our results demonstrate that an amorphous metal with B alloying effectively preserves the soft nature at the interface and detects the acoustic propagation and heat transport across it.

Anomalous thermal conductance of graphyne under lower temperature

2017 ◽  
Vol 29 (45) ◽  
pp. 455702 ◽  
Author(s):  
Xue-Kun Chen ◽  
Jun Liu ◽  
Dan Du ◽  
Ke-Qiu Chen
Keyword(s):  
Thermal Conductance ◽  
Lower Temperature
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