Thermoelectric Properties of PbTe/Pb1−x. Eux Te Quantum Wells

1998 ◽  
Vol 545 ◽  
Author(s):  
H. Scherrer ◽  
Z. Dashevsky ◽  
V. Kantser ◽  
A. Casian ◽  
I. Sur ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Variational Method ◽  
Quantum Wells ◽  
Power Factor ◽  
Thermoelectric Power Factor ◽  
Quantum Well Structures ◽  
Effective Masses ◽  
Dimensional Quantization ◽  
Carrier Scattering ◽  
Bulk Semiconductors

AbstractThe electrical conductivity, Seebeck coefficient, and thermoelectric power factor of PbTe/Pb1−xEuxTe quantum well structures are investigated theoretically. The variational method is employed. The anisotropy of effective masses, the multivalley character of the bulk semiconductors and also the dependence of effective masses in dimensional quantization subbands on the well width are taken into account. The carrier scattering both on optical and acoustical phonons is considered for structures with (111) and (100) crystallographic orientation. It is found that the power factor is larger in (100) oriented quantum wells. The results of recent experiments are discussed.

Coupled Quantum-Scattering Madeling of Thermoelectric Properties of Si/Ge/Si Quantum Well Structures

2006 ◽  
Author(s):  
A. Bulusu ◽  
D. G. Walker
Keyword(s):  
Thermal Conductivity ◽  
Electrical Conductivity ◽  
Quantum Wells ◽  
Phonon Scattering ◽  
Local Density ◽  
Quantum Scattering ◽  
Local Density Of States ◽  
Quantum Well Structures ◽  
Optical Phonon Scattering ◽  
Non Equilibrium Green’S Function

Confined structures presumably offer enhanced performance of thermoelectric devices. 1) Interfaces and boundaries create scattering sites for phonons, which reduces the thermal conductivity. 2) Reduced dimensionality increases the local density of states near the Fermi level, which increases the Seebeck coefficient. From these two phenomena, the net effect should be an increase in ZT, the performance parameter used to evaluate different materials and structures. These effects have been measured and modeled, but none of the models attempts to quantify the electron-phonon coupled effects particularly in the regime where quantum and scattering influences are found. Using the non-equilibrium Green's function (NEGF) approach, quantum wells composed of Si and Ge are studied and the important physics isolated. Results show a competing effect between the decrease in the electrical conductivity due to scattering with the increase in electrical conductivity with doping, leading to 77% decrease in the value of the power factor for the case of electron-optical phonon scattering.

scholarly journals Influence of crystallinity on the thermoelectric power factor of P3HT vapour-doped with F4TCNQ

RSC Advances ◽  
2018 ◽  
Vol 8 (3) ◽  
pp. 1593-1599 ◽  
Author(s):  
Jonna Hynynen ◽  
David Kiefer ◽  
Christian Müller
Keyword(s):  
Electrical Conductivity ◽  
Seebeck Coefficient ◽  
Thermoelectric Power ◽  
Power Factor ◽  
Thermoelectric Power Factor ◽  
Order Of Magnitude

The crystallinity of P3HT strongly benefits the electrical conductivity but not Seebeck coefficient, leading to an increase in power factor by one order of magnitude.

Investigating the key role of carrier transport mechanism in SnSe nanoflakes with enhanced thermoelectric power factor

2021 ◽  
Author(s):  
Srikanth Mandava ◽  
Neeta Bisht ◽  
Anjali Saini ◽  
Mukesh Kumar Bairwa ◽  
Khasimsaheb Bayikadi ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Ab Initio ◽  
Spark Plasma Sintering ◽  
Thermoelectric Properties ◽  
Power Factor ◽  
Temperature Range ◽  
Carrier Scattering ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
P Type

Abstract A novel SnSe nanoake system is explored for its thermoelectric properties from both experiments and ab initio study. The nanoakes of the low temperature phase of SnSe (Pnma) are synthesized employing a fast and efficient refluxing method followed by spark plasma sintering at two different temperatures. We report an enhanced power factor (12 W/mK2 - 67 W/mK2 in the temperature range 300 K-600 K) in our p-type samples. We find that the prime reason for a high PF in our samples is a significantly improved electrical conductivity (1050 S/m - 2180 S/m in the temperature range 300 K-600 K). From our ab initio band structure calculations accompanied with the models of temperature and surface dependent carrier scattering mechanisms, we reveal that an enhanced electrical conductivity is due to the reduced carrier-phonon scattering in our samples. The trans- port calculations are performed using the Boltzmann transport equation within relaxation time approximation. With our combined experimental and theoretical study, we demonstrate that the thermoelectric properties of p-type Pnma-SnSe could be improved by tuning the carrier scattering mechanisms with a control over the spark plasma sintering temperature.

Characterization of Cast Iron Scrap Chips toward β-FeSi2 Thermoelectric Materials

2014 ◽  
Vol 804 ◽  
pp. 3-6 ◽  
Author(s):  
Assayidatul Laila ◽  
Makoto Nanko
Keyword(s):  
Electrical Conductivity ◽  
Cast Iron ◽  
Seebeck Coefficient ◽  
Power Factor ◽  
Thermoelectric Materials ◽  
Cost Effective ◽  
Recycling Process ◽  
Thermoelectric Power Factor ◽  
Iron Scrap

The upgrade recycling process of cast-iron scrap chips toward β-FeSi2 is regarded as an eco-friendly and cost-effective production process. It is useful for reducing the material cost in fabricating β-FeSi2 by utilizing the waste that is obtained from the manufacturing process of cast-iron components. In this research, β-FeSi2 was successfully obtained from cast iron bscrap chips and showed good thermoelectric performance in Seebeck coefficient and electrical conductivity which is around 70% to almost 100% compared to β-FeSi2 that was prepared from pure Fe and other publications. The thermoelectric power factor was achieved 90% performance compared to other literatures and β-FeSi2 prepared from pure Fe.

scholarly journals Quantum-Dimensional Effects in Thermoelectric Characteristics of Lead Chalcogenides Nanostructures

2014 ◽  
Vol 1 (1) ◽  
pp. 65-72
Author(s):  
D.M. Freik ◽  
I.K. Yurchyshyn ◽  
V.Yu. Potyak
Keyword(s):  
Experimental Data ◽  
Electrical Conductivity ◽  
Theoretical Model ◽  
Seebeck Coefficient ◽  
Power Factor ◽  
Fermi Energy ◽  
Lead Chalcogenides ◽  
Thermoelectric Power Factor ◽  
Thermoelectric Parameters ◽  
Good Agreement

On the basis of theoretical model of quantum well (QW) with infinitely high walls it was investigated thermoelectric parameters depending on the thickness of the layer of nanostructures IV-VI (PbS, PbSe, PbTe) in the approximation of changing Fermi energy. There have been shown that the dependences of the Seebeck coefficient, electrical conductivity and thermoelectric power factor on well width for lead chalcogenides nanofilms are in good agreement with the experimental data. So, that proves the correctness of used model.

scholarly journals Synthesis and Thermoelectric Properties of Selenium Nanoparticles Coated with PEDOT:PSS

Polymers ◽  
2019 ◽  
Vol 11 (6) ◽  
pp. 1052 ◽  
Author(s):  
Chingu Kim ◽  
Jiyeon Hong ◽  
Ji-Woong Park
Keyword(s):  
Electrical Conductivity ◽  
Thin Layer ◽  
Thermoelectric Properties ◽  
Power Factor ◽  
Conductive Polymer ◽  
Selenium Nanoparticles ◽  
Hybrid Nanocomposite ◽  
Thermoelectric Power Factor ◽  
Percolating Network ◽  
Individual Polymer

We synthesized a hybrid nanocomposite comprised of selenium nanoparticles coated with a thin layer of a conductive polymer, poly(3,4-ethylenedioxythiophene), and studied its thermoelectric properties. The conductive polymer layer on the surface of nanoparticles in the composites formed a percolating network running between the stacked nanoparticles, exhibiting an electrical conductivity close to or higher than that of pure polymer. The thermoelectric power factor of the resulting composite was higher than that of individual polymer or selenium nanoparticles. We further increased the electrical conductivity of the composite by thermal annealing, thereby improving the power factor to 15 μW/cmK2 which is nine times higher than that of the polymer.

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