scholarly journals Scattering Mechanisms in pressed PbTe

2020 ◽  
Vol 21 (1) ◽  
pp. 82-88
Author(s):  
O. M. Matkivsky ◽  
Ya. P. Saliy ◽  
I. V. Horichok
Keyword(s):  
Seebeck Coefficient ◽  
Theoretical Calculation ◽  
Thermoelectric Properties ◽  
Specific Conductivity ◽  
Charge Carriers ◽  
Free Charge ◽  
Pressing Method ◽  
Scattering Mechanisms ◽  
Carrier Scattering ◽  
Powder Pressing

The results of studies of structural and thermoelectric properties obtained by the powder pressing method of PbTe samples are presented. In order to interpret the obtained results, a theoretical calculation of the specific conductivity and the Seebeck coefficient was performed on the basis of a model that takes into account two types of free charge carriers. Conclusions have been made about the mechanisms of carrier scattering.

Calculation of Carrier Scattering and Negative Magnetoresistance in Mn-Doped GaAs/InGaAs/GaAs Quantum Well with Ferromagnetism

2009 ◽  
Vol 152-153 ◽  
pp. 283-286 ◽  
Author(s):  
V.A. Kulbachinskii ◽  
L. Shchurova
Keyword(s):  
Quantum Well ◽  
Diluted Magnetic Semiconductor ◽  
Magnetic Semiconductor ◽  
Charge Carriers ◽  
Negative Magnetoresistance ◽  
Free Charge ◽  
Carrier Scattering ◽  
Diluted Magnetic ◽  
Mn Doped ◽  
The Magnetic Field

We have investigated the thermodynamic, transport and magnetotransport properties of free charge carriers in a diluted magnetic semiconductor with a quantum well InGaAs in the GaAs with δ-doped by C and Mn. In order to determine the density of the holes in a quantum well, we carried out thermodynamic calculations of the system of free holes, atoms Mn0 and ions Mn–. We calculated the temperature dependence of resistance and magnetoresistance of holes in the quantum well. The contributions of various scattering mechanisms of holes to the resistance were analyzed. The negative magnetoresistance are explained as the reduction of spin-flip scattering by aligning spins of the magnetic field.

scholarly journals The Thermoelectric Properties of Silver Doped of Lead Telluride

2016 ◽  
Vol 17 (2) ◽  
pp. 188-192
Author(s):  
M. A. Lopyanko ◽  
S. I. Mudri ◽  
S. V. Optasyuk ◽  
T. O. Semko ◽  
Т. С. Люба ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Seebeck Coefficient ◽  
Thermoelectric Properties ◽  
Impurity Concentration ◽  
Specific Conductivity ◽  
Lead Telluride ◽  
Pure Lead ◽  
Influence Of Temperature ◽  
Phase Pure

The synthesis and study the structure and thermoelectric properties of silver doped of lead telluride with impurity concentration of 0.3, 0.5, 1.0 at.%. Established that in the samples PbTe: Ag with impurity concentration > 0.5 at. % Ag present phase pure lead, due to reaching the solubility of impurities. The influence of temperature of annealing on Seebeck coefficient, thermal conductivity and specific conductivity was identified.

scholarly journals Enhanced Electrical Conductivity and Seebeck Coefficient in PEDOT:PSS via a Two-Step Ionic liquid and NaBH4 Treatment for Organic Thermoelectrics

Polymers ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 559
Author(s):  
Jonathan Atoyo ◽  
Matthew R. Burton ◽  
James McGettrick ◽  
Matthew J. Carnie
Keyword(s):  
Electrical Conductivity ◽  
Ionic Liquid ◽  
Seebeck Coefficient ◽  
Conformational Change ◽  
Thermoelectric Properties ◽  
Power Factor ◽  
Molecular Orientation ◽  
Combined Treatment ◽  
Charge Carriers ◽  
Subsequent Reduction

A two-step approach of improving the thermoelectric properties of Poly(3,4-ethylenedioxythiophene)poly(4-styrenesulfonate) (PEDOT:PSS) via the addition of the ionic liquid, 1-Ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide (EMIM:TFSI) and subsequent reduction with NaBH4 is presented. The addition of 2.5 v/v% of EMIM:TFSI to PEDOT:PSS increases the electrical conductivity from 3 S·cm−1 to 1439 S·cm−1 at 40 °C. An additional post treatment using the reducing agent, NaBH4, increases the Seebeck coefficient of the film from 11 µV·K−1 to 30 µV·K−1 at 40 °C. The combined treatment gives an overall improvement in power factor increase from 0.04 µW·m−1·K−2 to 33 µW·m−1·K−2 below 140 °C. Raman and XPS measurements show that the increase in PEDOT:PSS conductivity is due to PSS separation from PEDOT and a conformational change of the PEDOT chains from the benzoid to quinoid molecular orientation. The improved Seebeck coefficient is due to a reduction of charge carriers which is evidenced from the UV–VIS depicting the emergence of polarons.

Spectroscopic Mapping Ellipsometry of Graphene Grown on 3C SiC

2012 ◽  
Vol 1407 ◽  
Author(s):  
Alexander Boosalis ◽  
Tino Hofmann ◽  
Vanya Darakchieva ◽  
Rositza Yakimova ◽  
Tom Tiwald ◽  
...  
Keyword(s):  
Free Charge Carrier ◽  
Visible Spectrum ◽  
Charge Carriers ◽  
Physical Parameters ◽  
Free Charge ◽  
Carrier Scattering ◽  
Scattering Time ◽  
Charge Carrier Scattering ◽  
Lateral Variations

ABSTRACTSpectroscopic mapping ellipsometry measurements in the visible spectrum (1.25 to 5.35 eV) are performed to determine the lateral variations of epitaxial graphene properties as grown on 3C SiC. Data taken in the visible spectrum is sensitive to both the Drude absorption of free charge carriers and the characteristic exciton enhanced van Hove singularity at 5 eV. Subsequent analysis with simple oscillator models allows the determination of physical parameters such as free charge carrier scattering time and local graphene thickness with a lateral resolution of 50 microns.

Charge Carrier Scattering Mechanisms in Thermoelectric PbTe:Sb

2014 ◽  
Vol 59 (7) ◽  
pp. 706-711 ◽  
Author(s):  
D.M. Freik ◽  
◽  
S.I. Mudryi ◽  
I.V. Gorichok ◽  
R.O Dzumedze ◽  
...  
Keyword(s):  
Charge Carrier ◽  
Scattering Mechanisms ◽  
Carrier Scattering ◽  
Charge Carrier Scattering

Laser Engineering of Barrier Structures Based on Solid Solution ZnCdHgTe.

2002 ◽  
Vol 719 ◽  
Author(s):  
Galina Khlyap
Keyword(s):  
Room Temperature ◽  
Film Surface ◽  
Charge Carriers ◽  
Barrier Structure ◽  
Free Charge ◽  
Current Voltage ◽  
Capacitance Voltage ◽  
Laser Engineering ◽  
Charged Defects ◽  
Epilayer Surface

AbstractRoom-temperature electric investigations carried out in CO2-laser irradiated ZnCdHgTe epifilms revealed current-voltage and capacitance-voltage dependencies typical for the metal-semiconductor barrier structure. The epilayer surface studies had demonstrated that the cell-like relief has replaced the initial tessellated structure observed on the as-grown samples. The detailed numerical analysis of the experimental measurements and morphological investigations of the film surface showed that the boundaries of the cells formed under the laser irradiation are appeared as the regions of accumulation of derived charged defects of different type of conductivity supplying free charge carriers under the applied electric field.

Dielectric relaxation of free charge carriers in some fluorite-type solid solutions

1998 ◽  
Vol 244 ◽  
pp. 201-206 ◽  
Author(s):  
E.F. Hairetdinov ◽  
N.F. Uvarov ◽  
J.-M. Reau ◽  
P. Hagenmuller
Keyword(s):  
Dielectric Relaxation ◽  
Solid Solutions ◽  
Charge Carriers ◽  
Free Charge ◽  
Fluorite Type

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 Ferromagnetic Behaviors in Fe-Doped NiO Nanofibers Synthesized by Electrospinning Method

2013 ◽  
Vol 2013 ◽  
pp. 1-4 ◽  
Author(s):  
Yi-Dong Luo ◽  
Yuan-Hua Lin ◽  
Xuehui Zhang ◽  
Deping Liu ◽  
Yang Shen ◽  
...  
Keyword(s):  
Room Temperature ◽  
Doping Concentration ◽  
Double Exchange ◽  
Host Lattice ◽  
Charge Carriers ◽  
Fe Doping ◽  
Free Charge ◽  
Ferromagnetic Properties ◽  
Electrospinning Method ◽  
Fe Ions

Ni1−xFexOnanofibers with different Fe doping concentration have been synthesized by electrospinning method. An analysis of the phase composition and microstructure shows that Fe doping has no influence on the crystal structure and morphology of NiO nanofibers, which reveals that the doped Fe ions have been incorporated into the NiO host lattice. Pure NiO without Fe doping is antiferromagnetic, yet all the Fe-doped NiO nanofiber samples show obvious room-temperature ferromagnetic properties. The saturation magnetization of the nanofibers can be enhanced with increasing Fe doping concentration, which can be ascribed to the double exchange mechanism through the doped Fe ions and free charge carriers. In addition, it was found that the diameter of nanofibers has significant impact on the ferromagnetic properties, which was discussed in detail.

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