scholarly journals Correlations Between the Thermoelectric Power and Hall Effect of SN- or GE-Doped IN2O3Polycrystalline Ceramics

1997 ◽  
Vol 19 (4) ◽  
pp. 217-223 ◽  
Author(s):  
C. Marcel ◽  
J. Salardenne ◽  
S. Y. Huang ◽  
G. Campet ◽  
J. Portier
Keyword(s):  
Comparative Study ◽  
Hall Effect ◽  
Thermoelectric Power ◽  
Carrier Concentration ◽  
Cross Section ◽  
Lewis Acid ◽  
Carrier Mobility ◽  
Acid Strength ◽  
Metal Type ◽  
Dopant Element

The thermoelectric power and Hall effect of Sn-or Ge-doped In2O3ceramics are investigated based on a comparative study. The metal-type conductivity in both the samples occurs when the carrier concentration exceeds ~1019cm-3. The carrier mobility is found to be higher for Ge-doped samples. The relation between the <<Lewis acid strength>> of the dopant element and its scattering cross section is also presented.

scholarly journals Electronic Properties of Sn- or Ge-Doped In2O3Semiconductors

1993 ◽  
Vol 16 (1) ◽  
pp. 41-47 ◽  
Author(s):  
S. J. Wen ◽  
G. Campet
Keyword(s):  
Hall Effect ◽  
Electronic Properties ◽  
Single Crystals ◽  
Thermoelectric Power ◽  
Carrier Concentration ◽  
Carrier Mobility ◽  
Optoelectronic Devices ◽  
Type Conductivity ◽  
Metal Type

The thermoelectric power and Hall effect of In2O3single crystals, either undoped or Sn doped, and of In2O3ceramics, either undoped or Sn or Ge doped, are investigated. All doped samples have negative thermoelectric power values. The metal-type conductivity occurs when the carrier concentration exceeds l019cm–3The correspondence between the values of the thermoelectric power and those of the carrier mobility and carrier concentration is given. Most interestingly this study puts into light the enhanced carrier mobility occurring for Ge-doped In2O3samples compared with ITO samples (Sn-doped In2O3widely used in optoelectronic devices.

EFFECT OF TRANSITION IONS SUBSTITUTION ON THE PHYSICAL PROPERTIES OF Dy3Fe5O12 GARNET FERRITE

2011 ◽  
Vol 25 (13) ◽  
pp. 1757-1774
Author(s):  
DALAL. M. HEMEDA ◽  
ABDEL-RAOOF TAWFIK ◽  
OSAMA. M. HEMEDA ◽  
SALLY DEWIDAR
Keyword(s):  
Electrical Conductivity ◽  
Charge Carrier ◽  
Thermoelectric Power ◽  
Carrier Concentration ◽  
Carrier Mobility ◽  
Charge Carrier Mobility ◽  
Charge Carrier Concentration ◽  
Exothermic Peak ◽  
Dc Electrical Conductivity ◽  
Different Temperatures

Polycrystalline garnet ferrites Dy 3-x Ni x Fe 5 O 12, where (x = 0.0, 0.1, 0.2, 0.3, 0.4, and 0.5) have been prepared by the standard ceramic technique and their crystalline structure were identified by X-ray diffraction and IR spectroscopy. The differential thermal analysis (DTA) reveals two peaks. It is observed that an endothermic peak between 587 and 498 K for all samples which is due to the magnetic phase change from ferrimagnetic to paramagnetic state. The exothermic peak at about 700 K may be attributed to the crystallization of Dy 3-x Ni x Fe 5 O 12 with garnet structure. DC electrical resistivity, thermoelectric power, charge carrier concentration and charge carrier mobility have been studied at different temperatures: It was found that the DC electrical conductivity increases linearly with increasing temperature ensuring the semiconducting nature of samples. The values of the thermoelectric power were negative for samples of 0.0 < x < 0.4 indicating that the majority of the charge carrier are electrons in these samples while it was positive for sample of x = 0.5 at room temperature, and negative at high temperature. Using the values of the DC electrical conductivity and thermoelectric power, the values of the charge carrier concentration and the charge carrier mobility were calculated. Finally thermal properties have been studied.

Effect of Cu doping on the electrical Properties of ZnTe by Vacuum Thermal Evaporation

2018 ◽  
Vol 31 (3) ◽  
pp. 20
Author(s):  
Sarmad M. M. Ali ◽  
Alia A.A. Shehab ◽  
Samir A. Maki
Keyword(s):  
Activation Energy ◽  
Electrical Conductivity ◽  
Hall Effect ◽  
Carrier Concentration ◽  
Hall Mobility ◽  
Cu Doping ◽  
Before And After ◽  
Hall Effect Measurements ◽  
Evaporation Technique ◽  
P Type

In this study, the ZnTe thin films were deposited on a glass substrate at a thickness of 400nm using vacuum evaporation technique (2×10-5mbar) at RT. Electrical conductivity and Hall effect measurements have been investigated as a function of variation of the doping ratios (3,5,7%) of the Cu element on the thin ZnTe films. The temperature range of (25-200°C) is to record the electrical conductivity values. The results of the films have two types of transport mechanisms of free carriers with two values of activation energy (Ea1, Ea2), expect 3% Cu. The activation energy (Ea1) increased from 29meV to 157meV before and after doping (Cu at 5%) respectively. The results of Hall effect measurements of ZnTe , ZnTe:Cu films show that all films were (p-type), the carrier concentration (1.1×1020 m-3) , Hall mobility (0.464m2/V.s) for pure ZnTe film, increases the carrier concentration (6.3×1021m-3) Hall mobility (2m2/V.s) for doping (Cu at 3%) film, but  decreases by increasing Cu concentration.

scholarly journals Restructured single parabolic band model for quick analysis in thermoelectricity

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Jianbo Zhu ◽  
Xuemei Zhang ◽  
Muchun Guo ◽  
Jingyu Li ◽  
Jinsuo Hu ◽  
...  
Keyword(s):  
Fermi Level ◽  
Carrier Concentration ◽  
Carrier Mobility ◽  
Optimization Design ◽  
State Of The Art ◽  
Band Model ◽  
Carrier Effective Mass ◽  
Intermediate Variables ◽  
Level Calculation ◽  
Spb Model

AbstractThe single parabolic band (SPB) model has been widely used to preliminarily elucidate inherent transport behaviors of thermoelectric (TE) materials, such as their band structure and electronic thermal conductivity, etc. However, in the SPB calculation, it is necessary to determine some intermediate variables, such as Fermi level or the complex Fermi-Dirac integrals. In this work, we establish a direct carrier-concentration-dependent restructured SPB model, which eliminates Fermi-Dirac integrals and Fermi level calculation and emerges stronger visibility and usability in experiments. We have verified the reliability of such restructured model with 490 groups of experimental data from state-of-the-art TE materials and the relative error is less than 2%. Moreover, carrier effective mass, intrinsic carrier mobility and optimal carrier concentration of these materials are systematically investigated. We believe that our work can provide more convenience and accuracy for thermoelectric data analysis as well as instructive understanding on future optimization design.

Hall Effect, Resistivity and Thermoelectric Power of ZrSTe Crystals Grown By Direct Vapour Transport Method

2011 ◽  
Author(s):  
A. K. Dasadia ◽  
B. B. Nariya ◽  
D. N. Bhavsar ◽  
A. R. Jani ◽  
Alka B. Garg ◽  
...  
Keyword(s):  
Hall Effect ◽  
Thermoelectric Power ◽  
Vapour Transport ◽  
Transport Method

Empirical Lewis acid strengths for 135 cations bonded to oxygen

2017 ◽  
Vol 73 (5) ◽  
pp. 956-961 ◽  
Author(s):  
Olivier Charles Gagné ◽  
Frank Christopher Hawthorne
Keyword(s):  
Lewis Acid ◽  
Strong Correlation ◽  
Ionization Energy ◽  
Acid Strength ◽  
Lewis Base

New and updated Lewis acid strengths are listed for 135 cations bonded to oxygen for use with published Lewis base strengths. A strong correlation between Lewis acid strength and ionization energy is shown, and correlation with electronegativity is confirmed.

COMPARATIVE STUDY OF THE STRUCTURAL AND ELECTRONIC PROPERTIES OF BN(5, 5) AND C(5, 5) NANOTUBES UNDER PRESSURE

2010 ◽  
Vol 24 (24) ◽  
pp. 4851-4859
Author(s):  
KAIHUA HE ◽  
GUANG ZHENG ◽  
GANG CHEN ◽  
QILI CHEN ◽  
MIAO WAN ◽  
...  
Keyword(s):  
High Pressure ◽  
Comparative Study ◽  
Charge Density ◽  
Band Gap ◽  
Electronic Properties ◽  
Cross Section ◽  
First Principles ◽  
First Principles Calculations ◽  
Zinc Blende ◽  
Structural And Electronic Properties

The structural and electronic properties of BN(5, 5) and C(5, 5) nanotubes under pressure are studied by using first principles calculations. In our study range, BN(5, 5) undergoes obvious elliptical distortion, while for C(5, 5) the cross section first becomes an ellipse and then, under further pressure, is flattened. The band gap of BN(5, 5) decreases with increasing pressure, which is inverse to that of zinc blende BN, whereas for C(5, 5) the metallicity is always preserved under high pressure. The population of charge density indicates that intertube bonding is formed under pressure. We also find that BN(5, 5) may collapse, and a new polymer material based on C(5, 5) is formed by applying pressure.

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