scholarly journals Design of Peltier Element Based on Semiconductors with Hopping Electron Transfer via Defects

2021 ◽  
Vol 12 (1) ◽  
pp. 13-22
Author(s):  
N. A. Poklonski ◽  
S. A. Vyrko ◽  
A. I. Kovalev ◽  
I. I. Anikeev ◽  
N. I. Gorbachuk
Keyword(s):  
Charge State ◽  
Energy Gap ◽  
Energy Levels ◽  
Practical Interest ◽  
Band Gap Energy ◽  
Structural Defects ◽  
Band Model ◽  
Peltier Element ◽  
Intrinsic Defects ◽  
Charge States

The study of thermoelectric properties of crystalline semiconductors with structural defects is of practical interest in the development of radiation-resistant Peltier elements. In this case, the spectrum of energy levels of hydrogen-like impurities and intrinsic point defects in the band gap (energy gap) of crystal plays an important role.The purpose of this work is to analyze the features of the single-electron band model of semiconductors with hopping electron migration both via atoms of hydrogen-like impurities and via their own point triplecharged intrinsic defects in the c- and v-bands, as well as to search for the possibility of their use in the Peltier element in the temperature range, when the transitions of electrons and holes from impurity atoms and/or intrinsic defects to the c- and v-bands can be neglected.For Peltier elements with electron hopping migration we propose: (i) an h-diode containing |d1)and |d2)-regions with hydrogen-like donors of two types in the charge states (0) and (+1) and compensating them hydrogen-like acceptors in the charge state (−1); (ii) a homogeneous semiconductor containing intrinsic t-defects in the charge states (−1, 0, +1), as well as ions of donors and acceptors to control the distribution of t-defects over the charge states. The band diagrams of the proposed Peltier elements in equilibrium and upon excitation of a stationary hopping electric current are analyzed.A model of the h-diode containing hydrogen-like donors of two types |d1) and |d2) with hopping migration of electrons between them for 50 % compensation by acceptors is considered. It is shown that in the case of the reverse (forward) electrical bias of the diode, the cooling (heating) of the region of the electric double layer between |d1)and |d2)-regions is possible.A Peltier element based on a semiconductor with point t-defects is considered. It is assumed that the temperature and the concentration of ions of hydrogen-like acceptors and donors are to assure all t-defects to be in the charge state (0). It is shown that in such an element it is possible to cool down the metal-semiconductor contact under a negative electric potential and to heat up the opposite contact under a positive potential.

scholarly journals Low-Frequency Admittance of Capacitor with Working Substance “Insulator–Partially Disordered Semiconductor– Insulator”

2021 ◽  
Vol 12 (3) ◽  
pp. 202-210
Author(s):  
N. A. Poklonski ◽  
I. I. Anikeev ◽  
S. A. Vyrko
Keyword(s):  
Charge State ◽  
Crystalline Silicon ◽  
Low Frequency ◽  
Practical Interest ◽  
Structural Defects ◽  
Crystal Matrix ◽  
Single Electrons ◽  
Radiation Resistant ◽  
Charge States ◽  
State 1

The study of the electrophysical characteristics of crystalline semiconductors with structural defects is of practical interest in the development of radiation-resistant varactors. The capacitance-voltage characteristics of a disordered semiconductor can be used to determine the concentration of point defects in its crystal matrix. The purpose of this work is to calculate the low-frequency admittance of a capacitor with the working substance “insulator–crystalline semiconductor with point t-defects in charge states (−1), (0) and (+1)–insulator”. A layer of a partially disordered semiconductor with a thickness of 150 μm is separated from the metal plates of the capacitor by insulating layers of polyimide with a thickness of 3 μm. The partially disordered semiconductor of the working substance of the capacitor can be, for example, a highly defective crystalline silicon containing point t-defects randomly (Poissonian) distributed over the crystal in charge states (−1), (0), and (+1), between which single electrons migrate in a hopping manner. It is assumed that the electron hops occur only from t-defects in the charge state (−1) to t-defects in the charge state (0) and from t-defects in the charge state (0) to t-defects in the charge state (+1).In this work, for the first time, the averaging of the hopping diffusion coefficients over all probable electron hopping lengths via t-defects in the charge states (−1), (0) and (0), (+1) in the covalent crystal matrix was carried out. For such an element, the low-frequency admittance and phase shift angle between current and voltage as the functions on the voltage applied to the capacitor electrodes were calculated at the t-defect concentration of 3∙1019 cm−3 for temperatures of 250, 300, and 350 K and at temperature of 300 K for the t-defect concentrations of 1∙1019, 3∙1019, and 1∙1020 cm−3. 

scholarly journals THERMAL ACTIVATION ENERGY OF HOPPING ε2-CONDUCTION VIA BORON ATOMS IN WEAKLY COMPENSATED SILICON

2018 ◽  
Vol 62 (4) ◽  
pp. 406-414
Author(s):  
Nikolai A. Poklonski ◽  
Sergey A. Vyrko ◽  
Alexander I. Kovalev
Keyword(s):  
Activation Energy ◽  
Charge State ◽  
Energy Gap ◽  
Average Distance ◽  
Energy Levels ◽  
Band Shift ◽  
Impurity Atoms ◽  
V Band ◽  
Silicon Crystals ◽  
Charge States

The insulating side of the concentration insulator–metal phase transition (Mott’s transition) in p-type silicon crystals doped with acceptor (boron atoms) is considered under the conditions of stationary hopping electrical conduction. The boron atoms substitute silicon atoms in the crystal lattice and can be in one of the three charge states (−1, 0, +1), while the compensating impurity (donors) is in the charge state (+1). The distribution of impurity atoms is supposed to be random (Poisson’s distribution). The A0-band is formed from the energy levels of boron atoms in the charge states (0) and (−1), while the A+-band is formed from the energy levels of boron atoms in the charge states (+1) and (0). The decrease in the activation energy ε2 of thermally assisted tunneling transitions (hops) of holes between electrically neutral boron atoms, i. e. boron atoms that are in the charge state (0), is calculated. The ε2 quantity is approximately equal to an energy gap between A0- and A+-bands, i. e. Hubbard’s gap. In the quasi-classical approximation it is shown that the narrowing of the energy gap between A0- and A+-bands occurs due to: (i) the formation of a quasi-continuous band of allowed energy values for v-band holes from excited quantum states of boron atoms in the charge state (0), thus the value of the v-band shift into the band gap is determined by a maximum radius of the hole orbit in a boron atom, which does not exceed the half of the average distance between the nearest impurity atoms, and (ii) the splitting of the ground (non-excited) energy levels of the “molecular” pairs of boron atoms in the charge states (0) into triplet and singlet states of two holes. Calculations of ε2 without any adjustable parameters are quantitatively agree with the known experimental data on p-Si:B.

scholarly journals Band Gap Energy for SiC Thin Films Prepared By TEACO2 Laser Irradiated With Nuclear Radiation

2009 ◽  
Vol 6 (3) ◽  
pp. 578-583
Author(s):  
Baghdad Science Journal
Keyword(s):  
Thin Films ◽  
Energy Gap ◽  
Energy Levels ◽  
High Energy ◽  
Band Gap Energy ◽  
Nuclear Radiation ◽  
Gamma Source ◽  
High Energy Radiation ◽  
Energy Gaps ◽  
Uv Visible

The effect of high energy radiation on the energy gap of compound semiconductor Silicon Carbide (SiC) are viewed. Emphasis is placed on those effects which can be interpreted in terms of energy levels. The goal is to develop semiconductors operating at high temperature with low energy gaps by induced permanent damage in SiC irradiated by gamma source. TEACO2 laser used for producing SiC thin films. Spectrophotometer lambda - UV, Visible instrument is used to determine energy gap (Eg). Co-60, Cs-137, and Sr-90 are used to irradiate SiC samples for different time of irradiation. Possible interpretation of the changing in Eg values as the time of irradiation change is discussed

Dependence of Scintillators Optical Properties on Intrinsic Structural Defects

1994 ◽  
Vol 348 ◽  
Author(s):  
N.V. Kilassen
Keyword(s):  
Plastic Deformation ◽  
Optical Properties ◽  
Crystal Growth ◽  
Spectral Distribution ◽  
Light Output ◽  
Structural Defects ◽  
High Quality ◽  
Intrinsic Defects ◽  
Distribution Kinetics ◽  
Wide Range

ABSTRACTThe studies of the dependence of the optical properties of various scintillators on intrinsic structural defects have been reviewed. The greater part of the review is devoted to the defects introduced by plastic deformation. A wide range of variations in the light output, spectral distribution, kinetics and other properties has been observed. These defects can be induced during crystal growth, annealing, processing, etc. The proper regulation of the superstructure of intrinsic defects can ensure the production of high quality scintillators having required properties.

DFT STUDY OF STRUCTURAL AND ELECTRONIC PROPERTIES OF ENDOHEDRAL COMPLEXES OF GROUP V ATOMS WITH C60

2013 ◽  
Vol 27 (26) ◽  
pp. 1350152 ◽  
Author(s):  
AKSHU PAHUJA ◽  
SUNITA SRIVASTAVA
Keyword(s):  
Electronic Properties ◽  
Energy Gap ◽  
Central Atom ◽  
Energy Levels ◽  
Electronic Configuration ◽  
Group V ◽  
Foreign Atom ◽  
Endohedral Fullerenes ◽  
Endohedral Complexes ◽  
Structural And Electronic Properties

The structural and electronic properties of endohedral fullerenes formed by encapsulation of each of the group V elements inside the buckminsterfullerene cage have been investigated. The calculations reveal that all these species are thermodynamically stable, though the formation of Sb@C 60 and Bi@C 60 is slightly endothermic. The central atom preserves its electronic configuration and the quartet state. The energy gap and energy levels are perturbed by the inclusion of a foreign atom. The band gap of Sb@C 60 and Bi@C 60 is found to be significantly smaller than pristine C 60, suggesting the reactivity of these complexes.

Optical Detection of Band Gap Variations Due to Ordering in Ga0.47In0.53As on InP

1992 ◽  
Vol 281 ◽  
Author(s):  
D. J. Arent ◽  
K. A. Bertness ◽  
Sarah R. Kurtz ◽  
M. Bode ◽  
J. M. Olson
Keyword(s):  
Band Gap ◽  
Atmospheric Pressure ◽  
Room Temperature ◽  
Energy Gap ◽  
Growth Conditions ◽  
Band Gap Energy ◽  
Optical Energy Gap ◽  
Lower Growth ◽  
Transmission Electron ◽  
High Resolution Images

ABSTRACTA reduction in the optical energy gap of more than 65 meV has been observed in In0.53Ga0.47 As grown on (100) InP by atmospheric pressure metalorganic vapor phase epitaxy. The band gap energies were deduced from room temperature photocurrent spectroscopic measurements, accounting for differences in composition and strain. Spontaneous CuPt type ordering of In and Ga atoms on the (111) subplanes of the InGaAs2 was confirmed by transmission electron microscopy. Superlattice signatures in the transmission micrographs were observed only for samples with associated reduced band gap energies, and were confirmed by visible double periodicity in high resolution images. In0.53Ga0.47 As was grown under a variety of conditions, some which promoted ordering. In general, lower growth temperatures and moderate (∼4 μ/hr) growth rates promoted a greater degree of ordering and reduction of the band gap energy. The influence of growth conditions on the ordered structure is considered within the context of current theories.

scholarly journals Influence of Substrate Type and Dose of Implanted Ions on the Electrical Parameters of Silicon in Terms of Improving the Efficiency of Photovoltaic Cells

Energies ◽  
2020 ◽  
Vol 13 (24) ◽  
pp. 6708
Author(s):  
Paweł Węgierek ◽  
Justyna Pastuszak ◽  
Kamil Dziadosz ◽  
Marcin Turek
Keyword(s):  
Electrical Properties ◽  
Energy Gap ◽  
Energy Levels ◽  
Silicon Crystal ◽  
Photovoltaic Cells ◽  
Photovoltaic Cell ◽  
Additional Energy ◽  
Influence Of Substrate ◽  
Substrate Doping ◽  
Different Doses

The main goal of this work was to conduct a comparative analysis of the electrical properties of the silicon implanted with neon ions, depending on the dose of ions and the type of substrate doping, for the possibility of generating additional energy levels by ion implantation in terms of improving the efficiency of photovoltaic cells made on its basis. The article presents the results of research on the capacitance and conductance of silicon samples doped with boron and phosphorus, the structure of which was modified in the implantation process with Ne+ ions with energy E = 100 keV and different doses. The analysis of changes in electrical properties recorded at the annealing temperature of the samples Ta = 298 K, 473 K, 598 K, 673 K, and 873 K, concerned the influence of the test temperature in the range from 203 K to 373 K, as well as the frequency f from 100 Hz to 10 MHz, and voltage U from 0.25 V to 2 V. It was possible to detect intermediate bands in the tested samples and determine their position in the band gap by estimating the activation energy value. By means of implantation, it is possible to modify the width of the silicon energy gap, the value of which directly affects the efficiency of the photovoltaic cell made on its basis. By introducing appropriate defects into the silicon crystal lattice, contributing to a change in the value of the energy gap Eg, it is possible to increase the efficiency of the solar cell. On the basis of the obtained results, it can be seen that the highest activation energies are achieved for samples doped with phosphorus.

Formation of different charge states and the charge state fractions of sputtered Ti and Ni

1986 ◽  
Vol 166 (2-3) ◽  
pp. 458-479 ◽  
Author(s):  
H.J. Barth ◽  
E. Mühling ◽  
W. Eckstein
Keyword(s):  
Charge State ◽  
Charge States

Deep Defects in 3C-SiC Generated by H+- and He+-Implantation or by Irradiation with High-Energy Electrons

2010 ◽  
Vol 645-648 ◽  
pp. 439-442 ◽  
Author(s):  
Michael Weidner ◽  
Lia Trapaidze ◽  
Gerhard Pensl ◽  
Sergey A. Reshanov ◽  
Adolf Schöner ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Charge State ◽  
Cross Section ◽  
Capture Cross Section ◽  
Pulse Length ◽  
High Energy ◽  
Capture Cross ◽  
Intrinsic Defects ◽  
High Energy Electrons ◽  
Thermal Stability Of

Intrinsic defects in 3C-SiC are generated by implantation of H+- and He+-ions or irra¬diation with high energy electrons. The defect parameters and the thermal stability of the observed defects are determined. The capture-cross-section of the W6-center is directly measured by variation of the filling pulse length. The charge state of the W6-center is obtained from double-correlated DLTS investigations according to the Poole-Frenkel effect.

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