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.

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.

Spectroscopy of Zinc Oxide Thin Films near the Fundamental Absorption Edge

2021 ◽  
Author(s):  
V. T. Avanesyan ◽  
P. S. Provotorov ◽  
V. M. Stozharov ◽  
M. M. Sychev ◽  
A. A. Eruzin
Keyword(s):  
Thin Films ◽  
Zinc Oxide ◽  
Absorption Edge ◽  
Fundamental Absorption Edge ◽  
Oxide Thin Films

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).

OPTICAL ABSORPTION IN AMORPHOUS THIN FILMS OF SnO2 DEPOSITED BY THERMAL EVAPORATION

2007 ◽  
Vol 21 (12) ◽  
pp. 2017-2032 ◽  
Author(s):  
M. ANWAR ◽  
S. A. SIDDIQI ◽  
I. M. GHAURI
Keyword(s):  
Thin Films ◽  
Optical Absorption ◽  
Film Thickness ◽  
Substrate Temperature ◽  
Band Gap ◽  
Optical Band Gap ◽  
Fundamental Absorption Edge ◽  
Outward Diffusion ◽  
Optical Energy ◽  
Amorphous Thin Films

The fundamental absorption edge of SnO 2 amorphous thin films has been investigated. It has been observed that the optical energy gap decreases with the increase in film thickness, substrate temperature and post deposition annealing. The results are analysed by assuming optical absorption by non-direct transition. The decrease in optical band gap with increase in film thickness may be interpreted in terms of the incorporation of oxygen vacancies in the SnO 2 lattice. The decrease in optical energy due to the increase in substrate temperature may be ascribed to the release of trapped electrons by thermal energy or by the outward diffusion of the oxygen-ion vacancies, which are quite mobile even at low temperatures. The decrease in optical band gap due to annealing may be due to the formation of tin species of lower oxidation state.

The Structural, Optical and Electrical Properties of Spray Deposited Fluorine Doped ZnO Thin Films

2013 ◽  
Vol 1494 ◽  
pp. 139-144 ◽  
Author(s):  
Kondaiah Paruchuri ◽  
Vanjari Sundara Raja ◽  
Suda Uthanna ◽  
N. Ravi Chandra Raju
Keyword(s):  
Thin Films ◽  
Dopant Concentration ◽  
Hydrogen Atmosphere ◽  
Charge Carriers ◽  
Zno Films ◽  
Spray Pyrolysis Method ◽  
Fluorine Concentration ◽  
X Ray Diffraction ◽  
Glass Substrates ◽  
Starting Solution

ABSTRACTHighly transparent and conducting Fluorine doped zinc oxide thin films were deposited using spray pyrolysis method on glass substrates held at 450 °C. The X-ray diffraction study revealed that as the dopant concentration increases in ZnO films, the intensity of the preferential orientation of (002) reflection decreased and (101) was found to increase up to 5 at. % F. The crystallite size was varied from 40 to 50 nm with dopant concentration. The optical band gap of the un-doped films was 3.30 eV and it increased to 3.34 eV for 3 at. % F. The refractive index of the films was increased from 2.05 to 2.18 with the increase of dopant concentration from 0 to 5 at. %. The scanning electron microscopy results depicted that the microstructure of ZnO: F films highly influenced by the fluorine doping. After annealing the films in hydrogen atmosphere, the resistivity of the films decreased as increase the dopant concentration and it is 4×10−3 Ω cm for 3at. % F beyond which it increased. The mobility of the charge carriers was 14 cm2/ V sec and the carrier concentration was 7.8×1019 cm3 obtained for the films doped with 3 at. % of fluorine concentration in the starting solution.

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