Urbach Rule and Estimation of the Energy Gap Width in Molybdates

2020 ◽  
Vol 62 (8) ◽  
pp. 1325-1332 ◽  
Author(s):  
F. D. Fedyunin ◽  
D. A. Spassky
Keyword(s):  
Energy Gap ◽  
Urbach Rule ◽  
Gap Width

Photoswitching of the Optical and Electrical Properties of One-dimensional π-Electron Systems

2002 ◽  
Vol 57 (1-2) ◽  
pp. 89-93
Author(s):  
Nikolai Tyutyulkov ◽  
Fritz Dietz
Keyword(s):  
Electrical Conductivity ◽  
Electrical Properties ◽  
Light Absorption ◽  
Energy Gap ◽  
Optical And Electrical Properties ◽  
Electron Systems ◽  
Elementary Unit ◽  
One Dimensional ◽  
Correlation Correction ◽  
Gap Width

The photoswitching of the energy gap width of the isomeric forms of photoresponsive polymers with homomiclear photochrome diaryletheue elementary units is investigated theoretically, taking into account the correlation correction. It is shown that a real switching of electrical conductivity (insulator ⇔ semiconductor or conductor) can not be realized with polymers with alternant homomiclear π -electron systems within the elementary unit. A change and tuning-in of the light absorption is possible in most cases.

scholarly journals The electronic structure of the atom as a classification criterion of mineral technogenic waste

2021 ◽  
Vol 2131 (4) ◽  
pp. 042095
Author(s):  
A Sakharova ◽  
L Maslennikova
Keyword(s):  
Electronic Structure ◽  
Building Materials ◽  
Energy Gap ◽  
Chemical Elements ◽  
Raw Materials ◽  
Waste Recycling ◽  
Model Systems ◽  
Technogenic Waste ◽  
The Impact ◽  
Gap Width

Abstract Today, the total scientific classification of solid industrial waste is absent because of their diversity. The task of universal of mineral technogenic waste recycling is complicated by the difference in their composition. The nature of the chemical elements that make up building materials is always taken into account to predict their properties. In this regard, the purpose of the study was to determine the classification characteristics of mineral technogenic waste recycling on the basis of natural-scientific ideas about the electronic structure of the atom. Studies were conducted on model systems with ceramic oxides entering s-, p-, d- elements in ceramic matrix to test the impact of the electronic structure of the mineral waste cation on operational characteristics of building materials. The experimental results showed that the strength of the samples changes in the series s → p → d of the belonging of the introduced oxide cation to the electronic family. Additionally, such an indicator as the energy-gap width was used to study the nature of the contacting solid phases. It is possible to identify which substances in technogenic raw materials have the greatest effect on the performance of the material in value of the energy-gap width.

Photoswitching of the Optical and Electrical Properties of One-dimensional π-Electron Systems

2002 ◽  
Vol 57 (9-10) ◽  
pp. 89-93 ◽  
Author(s):  
Nikolai Tyutyulkov ◽  
Fritz Dietz Wilhelm-Ostwald
Keyword(s):  
Electrical Conductivity ◽  
Electrical Properties ◽  
Light Absorption ◽  
Energy Gap ◽  
Optical And Electrical Properties ◽  
Electron Systems ◽  
Elementary Unit ◽  
One Dimensional ◽  
Correlation Correction ◽  
Gap Width

The photoswitching of the energy gap width of the isomeric forms of photoresponsive polymers with homonuclear photochromic diarylethene elementary units is investigated theoretically, taking into account the correlation correction. It is shown that a real switching of electrical conductivity (insulator ⇔ semiconductor or conductor) can not be realized with polymers with alternant homonuclear π-electron systems within the elementary unit. A change and tuning-in of the light absorption is possible in most cases.

Radiation Hardness of Wide-Bandgap Materials as Exemplified by SiC Nuclear Radiation Detectors

2012 ◽  
Vol 717-720 ◽  
pp. 549-552
Author(s):  
Alexander M. Ivanov ◽  
Anton V. Sadokhin ◽  
Nikita B. Strokan ◽  
Alexander A. Lebedev ◽  
Vitalii V. Kozlovski
Keyword(s):  
Energy Gap ◽  
Radiation Detectors ◽  
Wide Bandgap ◽  
Nuclear Radiation ◽  
Wide Bandgap Materials ◽  
Nuclear Radiation Detectors ◽  
Gap Width ◽  
Radiation Centers ◽  
Bandgap Materials

Polarization effect characteristically occurs in detectors based on wide-bandgap materials at considerable concentrations of radiation defects. The appearance of an electromotive force in the bulk of a detector is due to the long-term capture of carriers at deep levels related to radiation centers. The kinetics and strength of the polarization field have been determined. The capture can be controlled by varying the detector temperature, with a compromise reached at the "optimal" temperature between the generation current and the position of the deepest of the levels whose contribution to the loss of charge via capture is negligible. It has been found that the depth of a level (related to the energy gap width) is close to 1/3, irrespective of a material. The optimal temperatures are strictly individual for materials.

Electronic properties of disordered zigzag carbon nanotubes

2015 ◽  
Vol 29 (05) ◽  
pp. 1550020 ◽  
Author(s):  
Hamed Rezania
Keyword(s):  
Density Of States ◽  
Nitrogen Doping ◽  
Energy Gap ◽  
Tight Binding ◽  
Binding Model ◽  
Electronic Density ◽  
Model Hamiltonian ◽  
Donor And Acceptor ◽  
Clean System ◽  
Gap Width

We study the density of states of zigzag carbon nanotube (CNT) doped with both Boron and nitrogen atoms as donor and acceptor impurities, respectively. The effect of scattering of the electrons on the electronic spectrum of the system can be obtained via adding random on-site energy term to the tight binding model Hamiltonian which describes the clean system. Green's function approach has been implemented to find the behavior of electronic density. Due to Boron (Nitrogen) doping, Fermi surface tends to the valence (conduction) band of semiconductor CNT so that the energy gap width reduces. Furthermore the density of states of disordered metallic zigzag CNTs includes a peak near the Fermi energy.

Pulsed Laser Deposition of Gallium Nitride on Sapphire

1997 ◽  
Vol 468 ◽  
Author(s):  
V. Talyansky ◽  
R. D. Vispute ◽  
R. P. Sharma ◽  
S. Choopun ◽  
M. J. Downes ◽  
...  
Keyword(s):  
Pulsed Laser Deposition ◽  
Deposition Temperature ◽  
Energy Gap ◽  
Pulsed Laser ◽  
Laser Deposition ◽  
High Quality ◽  
Rocking Curve ◽  
Gap Width ◽  
Minimum Yield

ABSTRACTWe have fabricated high quality single crystalline GaN films on sapphire (0001) substrates using pulsed laser deposition. Our best GaN films on sapphire (0001) featured the FWHM of the GaN (002) peak rocking curve of 7 arcmin, the RBS minimum yield of only 3%, and the energy gap width of 3.4 eV. The effect of the deposition temperature on the crystalline quality of the films is discussed.

ENERGY GAP IN THE HUBBARD MODEL

2000 ◽  
Vol 14 (07) ◽  
pp. 729-735
Author(s):  
L. DIDUKH ◽  
YU. DOVHOPYATY ◽  
YU. SKORENKYY
Keyword(s):  
Hubbard Model ◽  
Single Particle ◽  
Energy Gap ◽  
Particle Energy ◽  
Model Parameters ◽  
Metal Insulator Transition ◽  
Metal Insulator ◽  
Hartree Fock ◽  
New Variant ◽  
Gap Width

A new variant of the generalized Hartree–Fock approximation for calculation of single-particle Green function in the Hubbard model is proposed. The calculated single-particle energy spectrum allows to study metal–insulator transition. Dependences of the energy gap width and the polar states concentration on model parameters are obtained. Conditions of a metallic and an insulating state realisation are found.

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