scholarly journals Вклад распределенного эффекта Пельтье в эффективность ветви термоэлектрического охладителя

2022 ◽  
Vol 56 (1) ◽  
pp. 48
Author(s):  
О.И. Марков
Keyword(s):  
Impurity Distribution ◽  
Charge Carriers ◽  
Peltier Effect ◽  
Band Model ◽  
Zone Model ◽  
Thermoelectric Element ◽  
Maximum Value ◽  
Z Parameter ◽  
Overall Efficiency ◽  
Two Band Model

An attempt is made to calculate the contribution of the distributed Peltier effect to the efficiency of the branch of the thermoelement Z for various types of impurity distribution. For this purpose, the boundary problem of thermal balance in the branch of the thermoelectric element was solved numerically, taking into account the distributed Peltier effect. The case of non-degenerate charge carriers was considered within the framework of the standard two-band model. The parameters of charge carriers were selected close to thermoelectrics based on bismuth and antimony tellurides. As the calculation in the framework of the two-zone model showed, the use of the distributed Peltier effect leads only to partial absorption of Joule heat, which contributes to an increase in the overall efficiency of the branch. In this case, the Z parameter along a significant part of the branch takes values significantly less than the maximum value

scholarly journals Гальваномагнитные свойства тонких пленок Bi-=SUB=-95-=/SUB=-Sb-=SUB=-5-=/SUB=- на подложках с различным температурным расширением

2018 ◽  
Vol 44 (11) ◽  
pp. 71
Author(s):  
В.М. Грабов ◽  
В.А. Комаров ◽  
Е.В. Демидов ◽  
А.В. Суслов ◽  
М.В. Суслов
Keyword(s):  
Thin Films ◽  
Thermal Expansion ◽  
Coefficient Of Thermal Expansion ◽  
Substrate Material ◽  
Charge Carriers ◽  
Band Model ◽  
Film Material ◽  
Galvanomagnetic Properties ◽  
The Difference ◽  
Two Band Model

AbstractResults of an investigation of galvanomagnetic properties of Bi_95Sb_5 block thin films on substrates with different coefficients of thermal expansion covered with polyimide are presented. The difference between thermal expansions of the film material and the substrate was found to have a strong effect on the films’ galvanomagnetic properties. Analysis of the properties of the films using the two-band model showed that the concentration and mobility of the charge carriers in the Bi_95Sb_5 films are related to the coefficient of thermal expansion of the substrate material.

scholarly journals Оптические переходы и фотолюминесценция в цилиндрической ядро/слой/оболочка гетероструктуре beta-CdS/beta-HgS/beta-CdS

2020 ◽  
Vol 62 (8) ◽  
pp. 1159
Author(s):  
В.А. Aрутюнян ◽  
Д.Б. Айрапетян ◽  
Э.М. Казарян
Keyword(s):  
Electrostatic Interaction ◽  
State Energy ◽  
Wavelength Region ◽  
Individual Case ◽  
Charge Carriers ◽  
Band Model ◽  
Size Quantization ◽  
Short Wavelength Region ◽  
Mass Approximation ◽  
Two Band Model

In the effective mass approximation, within the framework of a simple two-band model, the states of charge carriers in the HgS quantizing layer of the cylindrical core/shell/shell β-CdS/β-HgS/β-CdS heterostructure are theoretically considered. The consideration was carried out for various intervals of geometric dimensions of sample, when the corresponding regimes of size quantization for charge carriers were realized in the layer. For each case, the electrostatic interaction between the electron and the hole is taken into account with its own specifics, and depending on the size of the sample, the corresponding values of the ground state energy of the pair are obtained. In each case, interband optical transitions in the sample and photoluminescence were also considered. It is shown that, in each individual case, taking into account the electrostatic interaction leads to a shift in the threshold frequency of interband absorption and luminescence to the short-wavelength region, and the frequency itself is determined by the geometric dimensions of the sample.

IONIZATION ENERGY AND IMPURITY BAND CONDUCTION OF SHALLOW DONORS IN n-GALLIUM ARSENIDE

1967 ◽  
Vol 45 (1) ◽  
pp. 119-126 ◽  
Author(s):  
J. Basinski ◽  
R. Olivier
Keyword(s):  
Ionization Energy ◽  
Impurity Band ◽  
Shallow Donor ◽  
Band Model ◽  
A Value ◽  
Transition Concentration ◽  
Temperature Electron ◽  
Two Band Model ◽  
Band Conduction ◽  
Made In

Hall effect and resistivity measurements have been made in the temperature range 4.2–360 °K on several samples of n-type GaAs grown under oxygen atmosphere and without any other intentional dopings. The principal shallow donor in this material is considered to be Si. All samples exhibited impurity-band conduction at low temperature. Electron concentrations in the conduction band were calculated, using a two-band model, and then fitted to the usual equation expressing charge neutrality. A value of 2.3 × 10−3 eV was obtained for the ionization energy of the donors, for donor concentration ranging from 5 × 1015 cm−3 to 2 × 1016 cm−3. The conduction in the impurity band was of the hopping type for these concentrations. A value of 3.5 × 1016 cm−3 was obtained for the critical transition concentration of the impurity-band conduction to the metallic type.

ENERGY BAND OVERLAPPING IN HIGH-Tc SUPERCONDUCTORS

1996 ◽  
Vol 10 (30) ◽  
pp. 1483-1490 ◽  
Author(s):  
M. MORENO ◽  
R. M. MÉNDEZ-MORENO ◽  
M. A. ORTIZ ◽  
S. OROZCO
Keyword(s):  
Weak Coupling ◽  
Cuprate Superconductors ◽  
Weak Coupling Limit ◽  
Band Model ◽  
Coupling Constant ◽  
High Tc Superconductors ◽  
Energy Bands ◽  
Effective Coupling ◽  
High Tc ◽  
Two Band Model

Multi-band superconductors are analyzed and the relevance of overlapping energy bands to the high-T c of these materials is studied. Within the BCS framework, a two band model with generalized Fermi surface topologies is developed. Values of the overlapped occupancy parameters for typical cuprate superconductors are obtained as a function of the ratio R and the effective coupling constant, λ, in the weak-coupling limit. The overlap scale is of the order or lower than the cutoff (Debye) energy. The typical behavior of the isotope effect is obtained. As these superconductors have transition temperatures above the phonon barrier, the results of this approach are important to the generic understanding of the high-T c superconducting mechanism.

Thermoelectric Power of the Liquid Sn—Te Alloy

1982 ◽  
Vol 37 (10) ◽  
pp. 1127-1131 ◽  
Author(s):  
D. H. Kurlat ◽  
M. Rosen
Keyword(s):  
Thermoelectric Power ◽  
Hard Sphere ◽  
Stoichiometric Composition ◽  
Band Model ◽  
Liquid Alloys ◽  
Sphere Approximation ◽  
The Difference ◽  
Predicted Values ◽  
Experimental Values ◽  
Two Band Model

The Seebeck coefficient (S) of Sni1-x- Tex liquid alloys was measured as a function of concentration and temperature. For 0 ≦ x <0.45 the behaviour is metallic; S values are small and negative, rising linearly with temperature. The predicted values of Ziman's theory when using the hard sphere approximation disagree with the experimental ones. The change in sign occurs for 0.45. For x = 0.5 (stoichiometric composition) the thermoelectric power decreases linearly with temperature. This fact is explained assuming a two-band model. For x ≧ 0.6 the liquid alloy becomes more semiconducting and presents a maximum in the isotherms of S for x = 0.65. For the excess tellurium concentration range we have calculated the difference EF - EV and γ/kB, assuming a S(1/T) law. The experimental values are compared with those of Dancy and Glazov.

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