Optimization of Maximum VO2 Content in Polymorphous Oxides of Vanadium

2013 ◽  
Vol 538 ◽  
pp. 113-116 ◽  
Author(s):  
S.N. Svitasheva
Keyword(s):  
Thin Films ◽  
Optical Properties ◽  
Optical Constants ◽  
Ellipsometric Method

Optical properties of thin films of vanadium thermally oxidized at air were studied by ellipsometric method using wavelength of He-Ne laser. Multipart composition of these films was revealed and method of optimization of technological conditions based on dynamic of changing optical constants near 68°C was developed.

Effects of alloying on the optical properties of organic–inorganic lead halide perovskite thin films

2016 ◽  
Vol 4 (33) ◽  
pp. 7775-7782 ◽  
Author(s):  
Paul F. Ndione ◽  
Zhen Li ◽  
Kai Zhu
Keyword(s):  
Thin Films ◽  
Optical Properties ◽  
Spectroscopic Ellipsometry ◽  
Optical Constants ◽  
Optical Transitions ◽  
Inorganic Perovskite ◽  
Inorganic Lead ◽  
Halide Perovskite ◽  
Lead Halide

Spectroscopic ellipsometry analysis of optical transitions and optical constants in hybrid organic–inorganic perovskite alloys.

Optical properties of Al-doped ZnO thin films obtained by the method of high-frequency magnetron sputtering

2021 ◽  
pp. 2150189
Author(s):  
A. Kashuba ◽  
H. Ilchuk ◽  
R. Petrus ◽  
I. Semkiv ◽  
O. Bovgyra ◽  
...  
Keyword(s):  
Thin Films ◽  
Refractive Index ◽  
Optical Properties ◽  
Magnetron Sputtering ◽  
High Frequency ◽  
Optical Constants ◽  
Zno Thin Films ◽  
Optical Parameters ◽  
Single Oscillator ◽  
Doped Zno

The optical constants and thickness of Al-doped ZnO (ZnO:Al(2.5 wt.%)) thin films prepared by high-frequency magnetron sputtering method are determined. ZnO:Al thin films are crystallized in the hexagonal structure from XRD studies. The optical constants and the bandgap of the films under study have been determined. Optical properties (refractive index [Formula: see text], absorption coefficient [Formula: see text], extinction coefficient [Formula: see text], dielectric functions [Formula: see text] and optical conductivity [Formula: see text]) of thin films and thickness [Formula: see text] can be determined from the transmission spectrum. The dispersion of the refractive index was explained using a single oscillator model. Single oscillator energy and dispersion energy are obtained from fitting. Optical parameters of the films were determined using the Cauchy, Sellmeier and Wemple models. The increasing value of dispersion parameter for polycrystalline thin films than for single crystals is observed. The fundamental absorption edge position (3.26 eV) in the transmittance spectrum of studied thin films corresponds to the values that are typical for ZnO:Al compound. No significant increase of the bandgap width was revealed by comparing ZnO:Al thin films with the known results of the optical studies of ZnO thin films. Possible reasons of such behavior were analyzed and the influence of bandgap increase on spectral behavior of optical functions are investigated. The material optical parameters such as normalized integrated transmission, zero and high-frequency dielectric constant, density of state effective mass ratio were also calculated.

Determination of Optical Properties of Fluorocarbon Polymer Thin Films by a Variable Angle Spectroscopic Ellipsometry

1999 ◽  
Vol 588 ◽  
Author(s):  
Kang-Kuk Lee ◽  
Jin-Goo Park ◽  
Hyung-Jae Shin
Keyword(s):  
Thin Films ◽  
Surface Roughness ◽  
Optical Properties ◽  
Optical Constants ◽  
Visible Spectrum ◽  
Phase Model ◽  
Lorentz Model ◽  
Three Phase ◽  
Variable Angle Spectroscopic Ellipsometry ◽  
Best Fit

AbstractOptical properties of vapor phase (VP) deposited and spin-coated fluorocarbon (FC) thin films on silicon substrates, such as refractive index, extinction coefficient and film thickness were characterized by a variable angle spectroscopic ellipsometry (VASE) in the range of 300–800 nm. A Lorentz model allows us to simulate the optical constants of the FC films with a minimum number of parameters while maintaining Kramers-Kronig (KK) consistency between the real and imaginary parts of the optical constants. FC films are nearly transparent over the visible spectrum, so it is possible to assume k (extinction coefficient) = 0 over part of the visible spectrum in a Cauchy model. To accurately simulate the obtained ellipsometric spectra, we performed a regression analysis in two steps assuming a three-phase and a four-phase model. The regression analysis was performed using the three-phase model and a best-fit mean-squared error (MSE) value of 1.717 (VP deposited FC film, Lorentz model) was obtained. However, the four-phase model was used to improve the best-fit result of 0.531 (VP deposited FC film, Lorentz model). The surface roughness layer was assumed to be a mixture of FC films and voids under the Bruggeman effective medium approximation (EMA). We found that the best-fit MSE was reduced when surface roughness was included.

scholarly journals Оптические свойства и электронные характеристики празеодима и неодима в конденсированном состоянии

2021 ◽  
Vol 129 (7) ◽  
pp. 848
Author(s):  
Л.А. Акашев ◽  
Н.А. Попов ◽  
В.Г. Шевченко
Keyword(s):  
Thin Film ◽  
Dielectric Constant ◽  
Optical Properties ◽  
Optical Constants ◽  
Liquid Metals ◽  
Infrared Region ◽  
Energy Losses ◽  
Liquid States ◽  
Ellipsometric Method ◽  
Band Conductivity

The optical properties of unoxidized surfaces of polycrystalline Pr and Nd films in the spectral range 0.4 - 2.6 μm are studied. Optical constants were measured by Beattie ellipsometric method. Dispersion dependences of the optical conductivity σ, the reflectivity R, imaginary and real parts of the dielectric constant ε1 and ε2, and the function of characteristic electron energy losses Im (ε) -1 were calculated using the obtained optical constants. The paper presents the optical properties of both films and liquid metals studied earlier. The electronic characteristics of praseodymium and neodymium in solid thin-film and liquid states are calculated using the results of measurements in the infrared region of the spectrum using the two-band conductivity model.

scholarly journals Optical Properties of Materials for Solar Energy Based on Cadmium Chalcogenides Thin Films

2019 ◽  
Vol 20 (4) ◽  
pp. 367-371 ◽  
Author(s):  
R.Yu. Petrus ◽  
H.A. Ilchuk ◽  
A.I. Kashuba ◽  
I.V. Semkiv ◽  
E.O. Zmiiovska ◽  
...  
Keyword(s):  
Thin Films ◽  
Refractive Index ◽  
Optical Properties ◽  
High Frequency ◽  
Optical Constants ◽  
Optical Parameter ◽  
Constant Density ◽  
Dispersion Energy ◽  
Cadmium Chalcogenides ◽  
Single Oscillator

The optical constants and thickness of cadmium chalcogenides (CdX, X= S, Se and Te) thin films prepared by quasi close-space sublimation and high-frequency magnetron sputtering method are determined. The optical constants and the band gap of the films under study have been determined. Optical properties (refractive index n(λ), extinction coefficient k(λ) and dielectric functions ε(λ)) of thin films and thickness d can be determined from the transmission spectrum. The dispersion of the refractive index was explained using a single oscillator model. Single oscillator energy and dispersion energy are obtained from fitting. The material optical parameter such as normalized integrated transmission, zero and high-frequency dielectric constant, density of state effective mass ratio was also calculated.

scholarly journals Doping effect by SiO2 on optical properties of ZnO Thin Films Prepared by pulsed laser depositions (PLD) technique

2019 ◽  
Vol 24 (1) ◽  
pp. 93
Author(s):  
Zuheer. N. Majeed1 ◽  
Abdul-Majeed E. Al-Samarai1 ◽  
Ghuson. H.Mohammed2
Keyword(s):  
Thin Films ◽  
Optical Properties ◽  
Absorption Coefficient ◽  
Optical Constants ◽  
Silicon Oxide ◽  
Energy Gap ◽  
Spectral Absorption ◽  
Coefficient Increase ◽  
Before And After ◽  
Pulse Deposition

In this paper,Zinc oxide was dopped by various concentrations (5,10,15,20,25) % wt, silicon oxide The mixture was deposited on glass substrate by laser pulse deposition at room temperature to obtain (Zn2SiO4) thin films .The optical properties of thin films  prepared on spectral absorption and transmission  recording were studied at  the wavelength range (200- 1100) nm. Some of the optical constants, including absorptance, transmission, absorption coefficient, and energy gap are calculated before and after annealing at (400 ̊C) for (1 hr). Absorptance values and absorption coefficient increase after doping and transmission and energy gap decreases after the doping. Absorbance values and absorption coefficient decreases after annealing and transmission and energy gap increase after  the annealing .   http://dx.doi.org/10.25130/tjps.24.2019.015   

Optical Properties of Cu2ZnSnSe4 Nanocrystalline Thin Films for Photovoltaic Devices

2015 ◽  
Vol 789-790 ◽  
pp. 90-94
Author(s):  
Anderson Dussan ◽  
Heiddy P. Quiroz ◽  
Jorge A. Calderón ◽  
Sandra M. López
Keyword(s):  
Thin Films ◽  
Surface Roughness ◽  
Refractive Index ◽  
Optical Properties ◽  
Extinction Coefficient ◽  
Optical Constants ◽  
High Surface ◽  
Photovoltaic Devices ◽  
Xrd Patterns ◽  
Nanocrystalline Thin Films

Presents a study of optical properties from transmittance measurements as a function of wavelength to CZTSe thin films (Cu2ZnSnSe4) using Bhattacharyya model and basic elements from the Swanepoel theory. The optical constants such as the absorption coefficient (α), the refractive index (n), the extinction coefficient (k) and physical properties such as gap (Eg), the real and imaginary part of the dielectric function (ε1 and ε2) and the film thickness (d), were determined. Gap values between 1.2 and 1.7 eV were obtained for compound when the mass (MX) of ZnSe was varied during the deposition stage. Inhomogeneity and high surface roughness were observed by SEM measurements for all samples. Size grain varying between 458.16 and 630.28 nm were obtained while the ZnSe binary mass varied from 0.171 to 0.153 g. Refractive index and extinction coefficient of Cu2ZnSnSe4 films were obtained for λ = 800 nm. A decrease of ε1 and ε2 was observed as the wavelength increases; it is associated with the presence of binary phases in the XRD patterns.

scholarly journals Optical properties of (ZnTiO3)/Epoxy Nanocomposite Thin films

2018 ◽  
Vol 6 (10) ◽  
Author(s):  
Warqaa Adnan Alqaicy ◽  
Sawsan H. Abdullah ◽  
Falah I. Mustafa ◽  
Khalid Kh.Ateia ◽  
Amnah M.Ibraheem
Keyword(s):  
Thin Films ◽  
Optical Properties ◽  
Optical Constants ◽  
Energy Gap ◽  
Ir Radiation ◽  
Epoxy Nanocomposite ◽  
Nanocomposite Thin Films ◽  
Magnetic Stirring ◽  
Nano Zinc ◽  
Very High

Two layers of epoxy reinforced with nano- Zinc Tetanet (ZnTiO3) uniform thin films have been prepared using a spin coating technique on glass floors, dispersion and magnetic stirring techniques are used to prepare the nanocomposites, FTIR was employed to aid interpretation of results with a fixed thickness and proportions by weight (0Wt%,1Wt%,2Wt%,3Wt%,4Wt%) ZnTiO3additives.The optical characteristics were studied by measuring the transmittance and absorbance spectrometry as a function of the wavelength (200-1100) nanometers. The results of the transmittance were very high, and high transparency in infrared (IR) radiation was measured by the FTIR and UV-VIS measurements. The optical properties included the calculations of the energy gap; some optical constants were also carried out, which included absorption coefficient making it  Suitable for applications of solar cells        

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