scholarly journals Закономерности температурных изменений спектров отражения инфракрасного излучения кристалла Bi-=SUB=-0.8-=/SUB=-Sb-=SUB=-1.2-=/SUB=-Te-=SUB=-3-=/SUB=- в области возбуждения плазменнных колебаний свободных носителей заряда и межзонных переходов

2021 ◽  
Vol 129 (5) ◽  
pp. 619
Author(s):  
Н.П. Степанов ◽  
А.А. Калашников
Keyword(s):  
Absorption Edge ◽  
Optical Band Gap ◽  
Fundamental Absorption Edge ◽  
Charge Carriers ◽  
Reflection Spectra ◽  
Free Charge ◽  
Plasmon Energy ◽  
Plasma Oscillations ◽  
Increasing Temperature ◽  
Plasmon Interaction

The regularities of the temperature behavior of the reflection spectra of the Bi0.8Sb1.2Te3 crystal obtained in the range of the plasma resonance of free charge carriers and the fundamental absorption edge allow us to trace the changes in the plasmon energy Ep and the optical band gap Eg opt. The observed decrease in Eg opt with increasing temperature corresponds to the existing ideas about the redistribution of holes between the nonequivalent extremes of the valence band in (Bi2-xSbx)Te3 (0<x<1) crystals. The dominance of this process in a certain temperature range contributes to the change in plasma frequencies. Keywords: reflection spectra, plasma oscillations, electron-plasmon interaction, dielectric functions.

scholarly journals Зонная структура и процессы в электронной системе кристаллов (Bi-=SUB=-2-x-=/SUB=-Sb-=SUB=-x-=/SUB=-)Te-=SUB=-3-=/SUB=- (0<x<2) по данным оптических исследований в инфракрасном диапазоне

2021 ◽  
Vol 55 (7) ◽  
pp. 586
Author(s):  
Н.П. Степанов ◽  
А.А. Калашников ◽  
О.Н. Урюпин
Keyword(s):  
Band Gap ◽  
Effective Mass ◽  
Temperature Change ◽  
Optical Band Gap ◽  
Charge Carriers ◽  
Reflection Spectra ◽  
Free Charge ◽  
Plasma Oscillations ◽  
Increasing Temperature ◽  
P Type

The decrease in the resonance frequency of plasma oscillations of free charge carriers omegap with increasing temperature observed in Bi2-xSbx (0 <x <2) p-type crystals can only be partially explained by an increase in the polarization background of the crystal ε-infinity. Analysis of the experimental data suggests that the temperature change in omegap observed in the range from 80 to 300 K is also due to a decrease in the ratio of the concentration of free charge carriers to their effective mass p / m *. This can be explained by an increase in the effective mass of carriers with increasing temperature, as well as by the process of hole redistribution between nonequivalent extrema of the valence band, the existence of which is confirmed by the regularities of the temperature change in the optical band gap observed in the reflection spectra of infrared radiation. Key words: semiconductors, plasma resonance, concentration, effective mass of free charge carriers, electrical conductivity, thermal and optical band gap.

scholarly journals Edge Absorption of thin Films –Ga2O3

2015 ◽  
Vol 16 (2) ◽  
pp. 302-306
Author(s):  
O.M. Bordun ◽  
B.O. Bordun ◽  
V.B. Lushchanets ◽  
I.Yo. Kukharskyy
Keyword(s):  
Thin Films ◽  
Heat Treatment ◽  
Absorption Edge ◽  
Optical Band Gap ◽  
Fundamental Absorption Edge ◽  
Hydrogen Atmosphere ◽  
Argon Atmosphere ◽  
Charge Carriers ◽  
Free Charge ◽  
Moss Effect

Fundamental absorption edge of b–Ga2O3 thin films, obtained by radio-frequency ion-plasmous sputtering, was investigated, using the method of optical spectroscopy. It was ascertained that the optical band gap Eg increases from 4.60 to 4.65 eV after the heat treatment films in argon atmosphere and to 5.20 eV after the reduction of annealed films in a hydrogen atmosphere. Consolidated effective mass of free charge carriers in b–Ga2O3 films after annealing and after reduction in hydrogen was estimated. It was found that the concentration of charge carriers after heat treatment in argon atmosphere is 7.30´1017 cm–3 and after reduction in hydrogen, is 2.62´1019 cm–3, which is typical for degenerated semiconductors. It was shown that the shift of fundamental absorption edge in thin films b–Ga2O3 after reduction in hydrogen is caused by Burstein-Moss effect.

scholarly journals Edge Absorption of (Y0.06Ga0.94)2O3 Thin Films

2017 ◽  
Vol 18 (1) ◽  
pp. 89-93
Author(s):  
O.M. Bordun ◽  
I.Yo. Kukharskyy ◽  
I.I. Medvid ◽  
Zh.Ya. Tsapovska
Keyword(s):  
Thin Films ◽  
Absorption Edge ◽  
Optical Band Gap ◽  
Fundamental Absorption Edge ◽  
Hydrogen Atmosphere ◽  
Argon Atmosphere ◽  
Charge Carriers ◽  
Oxygen Atmosphere ◽  
Free Charge ◽  
Monoclinic Structure

Fundamental absorption edge of (Y0,06Ga0,94)2O3 thin films, obtained by radio-frequency ion-plasmous sputtering, was investigated using the method of optical spectroscopy. It was established that these films are formed in the monoclinic structure of β-Ga2O3. The optical band gap of these films is greater than β-Ga2O3 films and is 4.66 eB for films annealed in oxygen atmosphere, 4.77 eV for the films annealed in argon atmosphere and 4.87 eV for the films, restored in a hydrogen atmosphere. Consolidated effective mass of free charge carriers in (Y0,06Ga0,94)2O3 films after annealing and after reconstitution in hydrogen was estimated. It was found that the concentration of charge carriers after annealing in oxygen atmosphere is 1.32×1018 cm-3, after annealing in argon atmosphere - 3.41×1018 cm-3 and after reconstitution in hydrogen is 5.20×1018 cm-3, which is typical for degenerated semiconductors. It was shown that the shift of fundamental absorption edge in (Y0,06Ga0,94)2O3 thin films is caused by Burstein-Moss effect.

Optical Investigation of Bi2O3-B2O3 Glass System

2010 ◽  
Vol 93-94 ◽  
pp. 336-339 ◽  
Author(s):  
Kitipun Boonin ◽  
Jakrapong Kaewkhao ◽  
Pichet Limsuwan
Keyword(s):  
Optical Absorption ◽  
Band Gap ◽  
Absorption Spectra ◽  
Wavelength Range ◽  
Absorption Edge ◽  
Optical Band Gap ◽  
Fundamental Absorption Edge ◽  
Optical Investigation ◽  
Optical Absorption Spectra ◽  
Molar Volumes

Glasses with composition xBi2O3:(100-x)B2O3 with 30x70 (in mol%) have been prepared using the normal melt-quench technique and investigated their properties. The optical absorption spectra of the glasses have been measured in the wavelength range 400-700 nm. It has been found that, the fundamental absorption edge has been identified from the optical absorption spectra. The values of optical band gap were decreased and the molar volumes were increased, with the addition of Bi2O3, due to the formulation of non-bridging oxygen (NBOs).

scholarly journals Оптические свойства монокристалла FeGe-=SUB=-2-=/SUB=-

2018 ◽  
Vol 60 (9) ◽  
pp. 1794
Author(s):  
Ю.П. Сухоруков ◽  
Р.И. Зайнуллина ◽  
А.А. Бучкевич ◽  
Н.Г. Бебенин
Keyword(s):  
Phase Transition ◽  
Optical Properties ◽  
Single Crystal ◽  
Spectral Region ◽  
Electronic States ◽  
Relaxation Frequency ◽  
Charge Carriers ◽  
Reflection Spectra ◽  
Plasma Oscillations ◽  
Temperature Range

AbstractThe reflection spectra of FeGe_2 single crystal in a wide spectral region and in the temperature range from 80 to 310 K are studied. The energy of plasma oscillations, the relaxation frequency of charge carriers, and phonon frequencies are determined. Anisotropy of the optical properties is studied. It is shown that the phase transition from the collinear antiferromagnetic structure to the spiral one is accompanied by a significant rearrangement of electronic states.

scholarly journals Корреляция оптических и магнитных свойств кристаллов Bi-=SUB=-2-=/SUB=-Te-=SUB=-3-=/SUB=--Sb-=SUB=-2-=/SUB=-Te-=SUB=-3-=/SUB=-

2019 ◽  
Vol 53 (6) ◽  
pp. 774
Author(s):  
Н.П. Степанов ◽  
А.К. Гильфанов ◽  
Е.Н. Трубицына
Keyword(s):  
Solid Solution ◽  
Magnetic Susceptibility ◽  
Optical Properties ◽  
Absorption Edge ◽  
Fundamental Absorption Edge ◽  
Sharp Decrease ◽  
Anisotropy Of Magnetic Susceptibility ◽  
Interband Transitions ◽  
Optical Studies ◽  
Plasmon Interaction

During the study of Bi2Te3-Sb2Te3 crystals, their magnetic and optical properties were studied depending on the ratios of the components of Bi2Te3 and Sb2Te3 in the composition of the solid solution and temperature. The results obtained allow us to state that a sharp decrease in the anisotropy of magnetic susceptibility at T = 293 K is observed in those samples in which, according to optical studies, electron-plasmon interaction is intensified, which is caused by the convergence of plasmon energies and interband transitions that form the fundamental absorption edge.

Effect of Bi2O3 Content on the Properties of Bi2O3-BaO-B2O3 Glass System

2008 ◽  
Vol 55-57 ◽  
pp. 869-872 ◽  
Author(s):  
Jakrapong Kaewkhao ◽  
Artorn Pokaipisit ◽  
Weerapong Chewpraditkul
Keyword(s):  
Optical Absorption ◽  
Band Gap ◽  
Molar Volume ◽  
Absorption Spectra ◽  
Absorption Edge ◽  
Optical Band Gap ◽  
Fundamental Absorption Edge ◽  
Optical Absorption Spectra ◽  
Network Modifier ◽  
Oxide Ion

Glasses with composition xBi2O3:(60-x)BaO:40B2O3 with 10£x£50 (in mol%) have been prepared using the normal melt-quench technique. The optical absorption spectra of the glasses have been recorded in the wavelength range 400-700 nm. The fundamental absorption edge has been identified from the optical absorption spectra. The values of optical band gap are decreased with the addition of Bi2O3. The density and molar volume studies indicated that Bi2O3 in these glasses is acting partly as network modifier and partly as network former.Values of the theoretical optical basicity are also reported and discuss in term of oxide ion polarizability.

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
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