Influence of different Ni nanolayers thicknesses on single oscillator model parameters, optical band gap, and disordering energy in CNTs synthesized by Cu‐Ni @ a‐CH catalyst

2021 ◽  
Author(s):  
Vali Dalouji ◽  
Samira Goudarzi
Keyword(s):  
Band Gap ◽  
Optical Band Gap ◽  
Oscillator Model ◽  
Model Parameters ◽  
Single Oscillator Model ◽  
Single Oscillator

scholarly journals Effect of gamma irradiation on structural, morphological and optical properties of p-quaterphenyl thin films

2018 ◽  
Vol 14 (2) ◽  
pp. 5624-5637
Author(s):  
A.A. Attia ◽  
M.M. Saadeldin ◽  
K. Sawaby
Keyword(s):  
Thin Films ◽  
Refractive Index ◽  
Optical Properties ◽  
Surface Morphology ◽  
Absorption Coefficient ◽  
Gamma Irradiation ◽  
Band Gap ◽  
Optical Band Gap ◽  
Thermal Evaporation Method ◽  
Single Oscillator Model

Para-quaterphenyl thin films were deposited onto glass and quartz substrates by thermal evaporation method. p-quaterphenyl thin films wereexposed to gamma radiation of Cobat-60 radioactive source at room temperature with a dose of 50 kGy to study the effect of ?-irradiation onthe structure and the surface morphology as well as the optical properties of the prepared films. The crystalline structure and the surface morphology of the as-deposited and ?-irradiated films were examined using the X-ray diffraction and the field emission scanning electron microscope. The optical constants (n & k) of the as-deposited and ?-irradiated films were obtained using the transmittance and reflectance measurements, in the wavelength range starting from 250 up to 2500 nm. The analysis of the absorption coefficient data revealed an allowed direct transition with optical band gap of 2.2 eV for the as-deposited films, which decreased to 2.06 eV after exposing film to gamma irradiation. It was observed that the Urbach energy values change inversely with the values of the optical band gap. The dispersion of the refractive index was interpreted using the single oscillator model. The nonlinear absorption coefficient spectra for the as-deposited and ?-irradiated p-quaterphenyl thin films were obtained using the linear refractive index.

Analysis of the dielectric constants of the Ag2O film by spectroscopic ellipsometry and single-oscillator model

2010 ◽  
Vol 405 (7) ◽  
pp. 1922-1926 ◽  
Author(s):  
Xiao-Yong Gao ◽  
Hong-Liang Feng ◽  
Jiao-Min Ma ◽  
Zeng-Yuan Zhang ◽  
Jing-Xiao Lu ◽  
...  
Keyword(s):  
Spectroscopic Ellipsometry ◽  
Dielectric Constants ◽  
Oscillator Model ◽  
Single Oscillator Model ◽  
Single Oscillator ◽  
Ag2o Film

scholarly journals Quantum Effects of Indium/Ytterbium Doping on ZnO-Like Nano-Condensed Matter in terms of Urbach-Martienssen and Wemple-DiDomenico Single-Oscillator Models Parameters

2012 ◽  
Vol 2012 ◽  
pp. 1-10 ◽  
Author(s):  
A. Boukhachem ◽  
B. Ouni ◽  
A. Bouzidi ◽  
A. Amlouk ◽  
K. Boubaker ◽  
...  
Keyword(s):  
Dielectric Constant ◽  
Optical Measurements ◽  
Model Parameters ◽  
Range Analysis ◽  
Dispersion Energy ◽  
Structural Investigations ◽  
Glass Substrates ◽  
Single Oscillator Model ◽  
Single Oscillator ◽  
Ytterbium Doping

Conducting and transparent optical ZnO thin films were deposited on glass substrates by a simple mini spray technique. Alternatively, some of the obtained films were doped with indium and ytterbium at the molar rates of: 1, 2, and 3% (In) and 100, 200, and 300 ppm (Yb). In addition to the classical structural investigations including XRD, microhardness vickers (Hv), and optothermal techniques, thorough optical measurements have been carried out for comparison purposes. The refractive indices and the extinction coefficients of the differently doped layers have been deduced from their transmission-reflection spectra over an extended wavelength range. Analysis of the refractive index data through Wemple-DiDomenico single oscillator model yielded quantum characteristics along with the values of long-wavelength dielectric constant, average oscillator wavelength, average oscillator strength, average oscillator energy and dispersion energy. Real and imaginary parts of dielectric constant have also been used to calculate free carrier plasma resonance frequency, optical relaxation time, and free carriers concentration-to-effective mass ratio. Finally, analysis of Urbach-Martienssen model parameters allowed proposing nanoscale explanations to the divergence about doping-related evolution of Urbach tails, this intriguing item having been intensively discussed in the literature in the last decades.

scholarly journals Temperature Dependence of the Refractive Index of Vitreous Alloys of the Ag-As-S System

2019 ◽  
Vol 19 (3) ◽  
pp. 234-238
Author(s):  
I. I. Shpak ◽  
I. Studenyak ◽  
O. Shpak
Keyword(s):  
Refractive Index ◽  
Temperature Dependence ◽  
Temperature Coefficient ◽  
Oscillator Model ◽  
Spectral Interval ◽  
Single Oscillator Model ◽  
Single Oscillator

The temperature coefficient of refractive index dn/dT is determined for glassy allous of the system along the(Ag2S)x(As2S3)100-x, direction (0 < x <20) in the spectral interval of 1–5 μm at temperature of 77– 400 K theglasses in question are shown to take negative values of dn/dT depending on the composition and wavelength.The dependence of the coefficient on spectrum and temperature is studied using a single oscillator model.

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