Growing of bulk β-(Al x Ga1-x )2O3 crystals from the melt by Czochralski method and investigation of their structural and optical properties

2021 ◽  
Author(s):  
Dmitrii A. Zakgeim ◽  
Dmitrii Bauman ◽  
Dmitrii Yi. Panov ◽  
Vladislav A. Spiridonov ◽  
Arina Kremleva ◽  
...  
Keyword(s):  
Optical Properties ◽  
Band Gap ◽  
Optical Transmission ◽  
Czochralski Method ◽  
Transmission Spectra ◽  
Structural And Optical Properties ◽  
X Ray ◽  
Al Content ◽  
Optical Transmission Spectra

Abstract Bulk (Al x Ga1-x )2O3 crystals with an Al fraction x in the range from 0.0 to 0.23 were successfully grown by the Czochralski method. An increase in the band gap from 4.7 eV to 5.1 eV with the rise of the Al content was demonstrated by analyzing optical transmission spectra. The crystal quality of the obtained samples was controlled by X-ray diffractometry. The appearance of crystal`s mosaic blockness was found for the Al fraction x above 0.05.

scholarly journals Выращивание объемных кристаллов оксида галлия из расплава методом Чохральского в кислородсодержащей атмосфере

2020 ◽  
Vol 46 (22) ◽  
pp. 43
Author(s):  
Д.А. Закгейм ◽  
Д.Ю. Панов ◽  
В.А. Спиридонов ◽  
А.В. Кремлева ◽  
А.М. Смирнов ◽  
...  
Keyword(s):  
Gallium Oxide ◽  
Optical Transmission ◽  
Czochralski Method ◽  
Transmission Spectra ◽  
X Ray ◽  
Growth Atmosphere ◽  
Optically Transparent ◽  
Optical Transmission Spectra ◽  
Oxide Crystals

This paper reports on successful experiments in growing beta-gallium oxide crystals using the Czochralski method. The influence of growth atmosphere composition on crystal quality of the material was studied. It is shown that to obtain high quality optically transparent crystals it is necessary to have about 5 vol.% oxygen in the growth atmosphere. X-ray structural analysis and investigation of optical transmission spectra of grown crystals are carried out.

On the Structural and Optical Properties of Lead Selenide Nanolayers

2014 ◽  
Vol 1025-1026 ◽  
pp. 831-836 ◽  
Author(s):  
Arif M. Pashaev ◽  
Omar I. Davarashvili ◽  
Megi I. Enukashvili ◽  
Zaira G. Akhvlediani ◽  
Larisa P. Bychkova ◽  
...  
Keyword(s):  
Optical Transmission ◽  
Lead Selenide ◽  
Transmission Spectra ◽  
Structural And Optical Properties ◽  
Total Contribution ◽  
X Ray ◽  
Optical Transmission Spectra ◽  
The Given ◽  
Gap Width ◽  
Forbidden Gap

It was revealed that, according to the analysis by the half-width of the X-ray lines of reflection planes (200) and (600), the sizes of subgrains in the lead selenide nanolayer ~70 nm thick made up 30-45 nm. Disorientation between the subgrains of the order of the ten thousandth of a minute and the deformation (strain) in the layer was determined by the mismatch between the layer and the substrate. It is shown that the forbidden gap width Eg of the same PbSe nanolayer determined by analyzing the optical transmission spectra by two types of straightening f (hν) and (hν)2=f (hν) coincided and made up 0.445 eV, which exceeded Eg of the unstrained PbSe layer by 0.16 eV. The total contribution of quantum effects at the given subgrain sizes and degeneracy of current carriers is less than 0.03 eV, and generally the change in the forbidden gap width was associated with deformation. Key words: dispersion, deformation, disorientation between subgrains, optical transmission, forbidden gap width.

scholarly journals Оптические свойства пленок ниобата бария стронция SBN61

2018 ◽  
Vol 60 (5) ◽  
pp. 993
Author(s):  
В.Б. Широков ◽  
А.В. Павленко ◽  
Д.В. Стрюков ◽  
Ю.В. Ревинский
Keyword(s):  
Refractive Index ◽  
Single Crystal ◽  
Band Gap ◽  
Optical Transmission ◽  
Visible Range ◽  
Transmission Spectra ◽  
X Ray Diffraction ◽  
Dispersion Parameters ◽  
X Ray ◽  
Optical Transmission Spectra

AbstractHeteroepitaxial Sr_0.61Ba_0.39Nb_2O_6 films have been formed on MgO(001) substrates by RF deposition in an oxygen atmosphere. The film orientation with respect to the substrate is investigated using X-ray diffraction. The permittivity dispersion parameters in the visible range are determined by measuring optical transmission spectra. The films are found to have a wider band gap and a smaller refractive index as compared with the single-crystal material.

scholarly journals Structural and Optical Properties ofIn2S3Thin Films Prepared by Flash Evaporation

2004 ◽  
Vol 27 (4) ◽  
pp. 207-214 ◽  
Author(s):  
K. Bouabid ◽  
A. Ihlal ◽  
A. Outzourhit ◽  
E. L. Ameziane
Keyword(s):  
Optical Properties ◽  
Optical Transmission ◽  
Annealing Temperature ◽  
Transmission Spectra ◽  
X Ray Diffraction ◽  
Flash Evaporation ◽  
Structural And Optical Properties ◽  
X Ray ◽  
Optical Gap ◽  
Deposited Films

In2S3thin films were deposited by flash evaporation ofIn2S3powder. The effect of annealing in vacuum and under sulphur atmosphere on the structural and optical properties of these films was investigated. X-ray diffraction studies reveal that the as-deposited films are amorphous. The formation ofβ-In2S3phase is obtained after annealing under vacuum at 693 K. Heat treatments under sulphur pressure lead to the formation of the above phase at a less annealing temperature (573 K). The energy dispersive X-ray (EDX) analysis reveals that the sulphurized films are nearly stoichiometric and those annealed in vacuum are sulphur deficient. Optical transmission spectra showed a slight shift of the absorption edge towards lower wavelengths. The optical gap value varied between 2.4 and 3 eV as a function of the film thickness and the annealing temperature.

Structural and Optical Properties of Nebulized Nickel Oxide Thin Films

2014 ◽  
Vol 938 ◽  
pp. 103-107
Author(s):  
V. Gowthami ◽  
M. Meenakshi ◽  
N. Anandhan ◽  
Chinnappanadar Sanjeeviraja
Keyword(s):  
Thin Films ◽  
Optical Properties ◽  
Nickel Oxide ◽  
Band Gap ◽  
X Ray Diffraction ◽  
Oxide Thin Films ◽  
Structural And Optical Properties ◽  
Functional Layer ◽  
X Ray ◽  
Nickel Oxide Thin Films

Nickel oxide has been widely used as material for antiferromagnetic, electrochromic display and functional layer for chemical sensors. Nickel oxide thin films of various molarities were deposited using a simple nebulizer technique and the substrate temperature was fixed at 350C. The effect of the molarity of precursor solution on structural and optical properties was studied using X-ray diffraction (XRD) and UV-Vis-NIR spectrometer techniques respectively. The band gap of the material was confirmed by photoluminescence spectrometer. It is found that increase in the molarity of 10ml volume of the sprayed solution leads to the increasing in film thickness. X-ray diffraction studies indicated cubic structure and the crystallites are preferentially oriented along (1 1 1) plane. It is also found that as the concentration of the solution increases the transmittance decreases, consequently the band-gap energy wanes from 4.0 eV to 3.2 eV.

scholarly journals Спектральные и рентгеновские исследования пленок оксида индия на сапфировых подложках

2020 ◽  
Vol 128 (10) ◽  
pp. 1544
Author(s):  
А.А. Тихий ◽  
Ю.М. Николаенко ◽  
Ю.И. Жихарева ◽  
И.В. Жихарев
Keyword(s):  
Optical Transmission ◽  
Deposition Time ◽  
Film Material ◽  
Transmission Spectra ◽  
X Ray Diffraction ◽  
Dc Magnetron Sputtering ◽  
X Ray ◽  
Transmission Measurements ◽  
Optical Transmission Spectra ◽  
Diffraction Patterns

The results of investigation of optical transmission spectra and X-ray diffraction of thin In2O3 films deposited by dc-magnetron sputtering on Al2O3 (012) substrates are presented. The diffraction patterns exhibit the presents of the (222) reflex of cubic In2O3. Its position shifts from 30.3 to 30.6°, with a decrease in the film thickness. There was also a decrease in the half-width of this reflex by a decrease in the deposition time, which may indicate an increase in the crystallite size of the film material. According to the optical transmission measurements, the presence of a transition layer with the band gap of 1.39 eV and about of 40 nm thickness was established at the interface between the film and substrate. The properties of this layer are independent of the deposition time.

Optical Properties of MBE Grown Cubic AlGaN Epilayers and AlGaN/GaN Quantum Well Structures

2000 ◽  
Vol 639 ◽  
Author(s):  
D.J. As ◽  
T. Frey ◽  
M. Bartels ◽  
A. Khartchenko ◽  
D. Schikora ◽  
...  
Keyword(s):  
Optical Properties ◽  
Quantum Well ◽  
Linear Increase ◽  
X Ray Diffraction ◽  
Quantum Well Structures ◽  
X Ray ◽  
Al Content ◽  
Frequency Plasma ◽  
Multi Quantum Well

ABSTRACTCubic AlyGa1−yN/GaN heterostructures on GaAs(001) substrates were grown by radio-frequency plasma-assisted molecular beam epitaxy. High resolution X-ray diffraction, spectroscopic ellipsometry and cathodoluminescence were used to characterize the structural and optical properties of the alloy epilayers. X-ray diffraction reciprocal space maps demonstrate the good crystal quality of the cubic AlyGa1−yN films. Both SE as well as room temperature CL of the AlyGa1−yN epilayer show a linear increase of the band gap with increasing Al-content. A pseudomorphically strained cubic 10 × (2.4 nm GaN/ 4.8 nm Al0.12Ga0.88N) multi-quantum well (MQW) structure has been realized. Cathodoluminescence clearly demonstrates strong radiative recombination due to quantized states in the GaN well layer at a photon energy of 3.323 eV.

Optical Properties of Colloidal MoS2

1992 ◽  
Vol 283 ◽  
Author(s):  
G. A. Wagoner ◽  
P. D. Persans ◽  
A. F. Ruppert
Keyword(s):  
Optical Transmission ◽  
Transmission Spectra ◽  
Average Thickness ◽  
X Ray Diffraction ◽  
X Ray ◽  
Typical Sample ◽  
Exciton Region ◽  
Optical Transmission Spectra ◽  
Synthetic Crystals ◽  
Particle Aspect Ratio

ABSTRACTWe report measurements and analysis of the optical transmission spectra of colloidal 2H-M0S2. prepared by ultrasonic shattering of synthetic crystals in N-Methyl Formamide. We used a combination of TEM, X-ray diffraction and dynamic light scattering to characterize particle shape and size. For a typical sample, the particles are platelets which have an average thickness of 50 Å and a diameter of 500 Å. Particle dielectric functions, deduced from both dilute colloids and thin films prepared by flocculaUon, differ significantly from bulk values. Calculations show that the average extinction coefficient is affected by particle aspect ratio, but this can not explain all the features of the data. Specifically, we observe a suppression of the absorbance peaks in the band edge exciton region between 1.7 and 2.1 eV, and increased absorbance below 1.7 eV. We suggest that the particles do not possess bulk-like dielectric properties and that tins is due to defects.

scholarly journals The Effect of the Deposition Method on the Structural and Optical Properties of ZnS Thin Films

Coatings ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1064
Author(s):  
Iosif-Daniel Simandan ◽  
Florinel Sava ◽  
Angel-Theodor Buruiana ◽  
Ion Burducea ◽  
Nicu Becherescu ◽  
...  
Keyword(s):  
Thin Films ◽  
Optical Properties ◽  
Band Gap ◽  
Rutherford Backscattering Spectrometry ◽  
Wide Band ◽  
Deposition Method ◽  
X Ray Diffraction ◽  
Structural And Optical Properties ◽  
Wide Band Gap ◽  
X Ray

ZnS is a wide band gap material which was proposed as a possible candidate to replace CdS as a buffer layer in solar cells. However, the structural and optical properties are influenced by the deposition method. ZnS thin films were prepared using magnetron sputtering (MS), pulsed laser deposition (PLD), and a combined deposition technique that uses the same bulk target for sputtering and PLD at the same time, named MSPLD. The compositional, structural, and optical properties of the as-deposited and annealed films were inferred from Rutherford backscattering spectrometry, X-ray diffraction, X-ray reflectometry, Raman spectroscopy, and spectroscopic ellipsometry. PLD leads to the best stoichiometric transfer from target to substrate, MS makes fully amorphous films, whereas MSPLD facilitates obtaining the densest films. The study reveals that the band gap is only slightly influenced by the deposition method, or by annealing, which is encouraging for photovoltaic applications. However, sulphur vacancies contribute to lowering the bandgap and therefore should be controlled. Moreover, the results add valuable information towards the understanding of ZnS polymorphism. The combined MSPLD method offers several advantages such as an increased deposition rate and the possibility to tune the optical properties of the obtained thin films.

Effect of Dysprosium Nanoparticles on the Optical Properties of Zinc Borotellurite Glass Systems

2017 ◽  
Vol 268 ◽  
pp. 13-17 ◽  
Author(s):  
M.N. Ami Hazlin ◽  
Mohamed Kamari Halimah ◽  
Farah Diana Mohammad ◽  
M.F. Faznny ◽  
Shahrim Mustafa Iskandar
Keyword(s):  
Optical Properties ◽  
Band Gap ◽  
Optical Band Gap ◽  
Urbach Energy ◽  
Molar Fraction ◽  
X Ray Diffraction ◽  
Structural And Optical Properties ◽  
X Ray ◽  
Vis Spectroscopy ◽  
Amorphous Nature

The glass samples of zinc borotellurite glass doped with dysprosium nanoparticles with chemical formula TeO20.7B2O30.30.7ZnO0.31-xDy2O3x (where x= 0.01, 0.02, 0.03, 0.04 and 0.05 molar fraction) have been fabricated by using melt quenching technique. In this study, the structural and optical properties of the zinc borotellurite glass doped with dysprosium nanoparticles were characterized by using X-ray diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR) and UV-Vis spectroscopy. From the XRD, the amorphous nature of the glass samples has been confirmed. The infrared spectra revealed four obvious bands which are assigned for BO3, BO4 and TeO4 vibrational groups. The direct and indirect optical band gap, as well as Urbach energy, was calculated through absorption spectra obtained from UV-Vis spectroscopy. From the spectra, it is observed that both direct and indirect optical band gap decreases as the concentration of dysprosium nanoparticles increase. Other than that, the Urbach energy is observed to have an inverse trend with the optical band gap. The Urbach energy is increases as the concentration of dysprosium nanoparticles increases.

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