Nb2O5: energy gap, optical properties

2005 ◽  
pp. 1-6
Author(s):  
Keyword(s):  
Optical Properties ◽  
Energy Gap

First-Principles Study on Electronic and Optical Properties in Pr-Doped Anatase TiO2

2014 ◽  
Vol 924 ◽  
pp. 260-268 ◽  
Author(s):  
Hao Chen ◽  
Lan Fang Yao ◽  
Song Lin Yang ◽  
Ya Qin Wang ◽  
Xing Liang ◽  
...  
Keyword(s):  
Optical Properties ◽  
Photocatalytic Activity ◽  
First Principles ◽  
Energy Gap ◽  
Impurity Band ◽  
Anatase Tio2 ◽  
Electron Hole ◽  
Light Region ◽  
Overlap Population ◽  
Calculation Results

The crystal structures, band structures, density of states, charge density, overlap population and optical properties of pure anatase TiO2 and Pr-doped anatase TiO2 were studied by using the plane-wave pseudopotential method based on the first-principles. After Pr doping, the valence band and the conduction band moved down and became dense, energy gap became narrow and a impurity band which consists of Pr 4f states appeared. And the dipole moment got improved, which is good for the separate of the electron-hole pairs. These effectively overcome two huge shortcomings of TiO2. Besides, Pr-doped anatase TiO2 produced more carriers which have good transport properties and the absorption spectra of Pr-O bond appear in the region that the wavelength is longer. The calculation results of optical properties show that the absorption edge occured red shift, which means the photocatalytic activity of anatase TiO2 got remarkable improved during visible-light region. This conforms to the previous analysis. So the photocatalytic activity of anatase TiO2 got remarkable improved after Pr doping.

Structural and Optical Properties of (PVA/PVP:Sr2NO3) Nanocomposites

2021 ◽  
Vol 19 (4) ◽  
pp. 27-37
Author(s):  
Doaa E. Al-Kateb ◽  
Ali R. Abdulridha
Keyword(s):  
Optical Properties ◽  
Energy Gap ◽  
Ftir Spectra ◽  
Structural And Optical Properties ◽  
Casting Method ◽  
Forbidden Transitions ◽  
Nanoparticles Concentration

In this study preparing and investigating of the (PVA/PVP:Sr2NO3) nanocomposites films by using casting method with different concentration of Sr2NO3 as (0, 1, 3, 5, and 7 wt. %). Optical properties obtained by UV-Vis spectrometer, OM and FTIR spectra have been revealed in this study, the absorbance increased by increasing of Sr2NO3 nanoparticles concentrations, the energy-gap (allowed and forbidden) transitions decreased by increasing of the nanoparticles concentration.

Theoretical investigation on tautomerism and NLO properties of Salicylideneaniline derivatives

2021 ◽  
Author(s):  
N. Daho ◽  
N. Benhalima ◽  
F. KHELFAOUI ◽  
O. SADOUKI ◽  
M. Elkeurti ◽  
...  
Keyword(s):  
Optical Properties ◽  
Density Functional ◽  
Energy Gap ◽  
Intramolecular Proton Transfer ◽  
Basis Set ◽  
Frontier Molecular Orbital ◽  
Molecular Orbital Calculations ◽  
Visible Absorption ◽  
Charge Delocalization ◽  
Intramolecular Hydrogen

In this work, a comprehensive investigation of the salicylideneaniline derivatives is carried out using density functional theory to determine their linear and non-linear optical properties. Geometry optimizations, for gas and solvent phases, of the tautomers (enol and keto forms) are calculated using B3LYP levels with 6–31G (d,p) basis set . An intramolecular proton transfer, for 1SA-E and 2SA-E, is performed by a PES scan process at the B3LYP/6-31G (d,p) level. The optical properties are determined and show that they have extremely high nonlinear optical properties. In addition, the RDG analysis, MEP, and gap energy are calculated. The low energy gap value indicates the possibility of intramolecular charge transfer. The frontier molecular orbital calculations clearly show the inverse relationship of HOMO–LUMO gap with the first-order hyperpolarizability (β = 59.6471 × 10-30 esu), confirming that the salicylideneaniline derivatives can be used as attractive future NLO materials. Therefore, the reactive sites are predicted using MEP and the visible absorption maxima are analyzed using a theoretical UV–Vis spectrum. Natural bond orbitals are used to investigate the stability, charge delocalization, and intramolecular hydrogen bond.

Synthesis, Characterization and Optical Properties of PLA / P3HT Blends Thin Films

2021 ◽  
Vol 19 (5) ◽  
pp. 132-138
Author(s):  
Maan Abd-Alameer Salih ◽  
Q.S. Kareem ◽  
Mohammed Hadi Shinen
Keyword(s):  
Thin Films ◽  
Optical Properties ◽  
Spin Coating ◽  
Ring Opening ◽  
Energy Gap ◽  
Ring Opening Polymerization ◽  
X Ray Diffraction ◽  
X Ray ◽  
Conductivity Increase ◽  
Ft Ir

In this exploration Poly lactic corrosive (PLA) was orchestrated the ring-opening polymerization Poly lactic corrosive (PLA) blended with poly(3-hexylthiophene) (P3HT) which prepared by solution. Blends thin films Synthesis by spin coating technique and using Tetrahydrofuran (THF) as solvent. PLA powder was 'characterized by' 'X-ray' 'diffraction', '(FT-IR)'. pure Optical properties (PLA), (PLA)/P3HT blends thin films with different percentage of P3HT (0, 1, 2, and 3) wt% were investigated using UV-VS spectroscopy The results showed that the absorption, absorption coefficient, extinction coefficient and conductivity increase with increasing the rate of deformation P3HT, The energy gap decreases with increasing deformation.

scholarly journals Photothermal Deflection Spectroscopy Study of Nanocrystalline Si (nc-Si) Thin Films Deposited on Porous Aluminum with PECVD

2012 ◽  
Vol 2012 ◽  
pp. 1-5 ◽  
Author(s):  
S. Ktifa ◽  
M. Ghrib ◽  
F. Saadallah ◽  
H. Ezzaouia ◽  
N. Yacoubi
Keyword(s):  
Optical Properties ◽  
Energy Gap ◽  
Chemical Vapor ◽  
Nanocrystalline Silicon ◽  
Porous Aluminum ◽  
Force Microscopy ◽  
Photothermal Deflection Spectroscopy ◽  
Atomic Force ◽  
Photothermal Deflection ◽  
Morphology Characterization

We have studied the optical properties of nanocrystalline silicon (nc-Si) film deposited by plasma enhancement chemical vapor deposition (PECVD) on porous aluminum structure using, respectively, the Photothermal Deflection Spectroscopy (PDS) and Photoluminescence (PL). The aim of this work is to investigate the influence of anodisation current on the optical properties of the porous aluminum silicon layers (PASL). The morphology characterization studied by atomic force microscopy (AFM) technique has shown that the grain size of (nc-Si) increases with the anodisation current. However, a band gap shift of the energy gap was observed.

scholarly journals Empirical Relation for Electronic and Optical Properties of Binary Tetrahedral Semiconductors

2021 ◽  
Keyword(s):  
Dielectric Constant ◽  
Optical Properties ◽  
Atomic Number ◽  
Energy Gap ◽  
Empirical Relation ◽  
Average Energy ◽  
Optical Parameters ◽  
Dielectric Analysis ◽  
Average Atomic Number ◽  
Tetrahedral Semiconductors

The concept of ionicity has been developed by Phillips and Van Vechten from the dielectric analysis of the semiconductors and insulators to evaluate various bond parameters of binary tetrahedral (AIIBVI and AIIIBV) semiconductors. In this paper, an advance hypothesis of average atomic number of the elements in a compound has been used to evaluate intrinsic electronic and optical parameters such as ionic gap (Ec), average energy gap (Eg), crystal ionicity (fi) and dielectric constant (ϵ) of binary tetrahedral semiconductors.

scholarly journals Effects of Cu-Doping on Optical Properties of NiO

2015 ◽  
Vol 48 ◽  
pp. 155-162 ◽  
Author(s):  
Nidhal Nissan Jandow
Keyword(s):  
Thin Film ◽  
Optical Properties ◽  
Absorption Coefficient ◽  
Extinction Coefficient ◽  
Energy Gap ◽  
Spray Pyrolysis Technique ◽  
Skin Depth ◽  
Cu Doping ◽  
Uv Visible ◽  
Absorbance Spectra

This work presents the effect of Cu-doping on some optical properties of Cu:NiO thin film prepared by spray pyrolysis technique. UV-Visible spectrophotometer in the range 380-900 nm used to determine the absorbance spectra for various Cu-doping of Cu:NiO thin film. The transmittance and energy gap are decreased with increasing Cu-doping in the prepared films, while absorption coefficient, extinction coefficient, and skin depth are increased with increasing Cu-doping.

scholarly journals A Study of the Structural and Optical Properties of SnS:F prepared by chemical spray pyrolysis technique

2014 ◽  
Vol 11 (2) ◽  
pp. 518-526
Author(s):  
Baghdad Science Journal
Keyword(s):  
Optical Properties ◽  
Spray Pyrolysis ◽  
Energy Gap ◽  
Spray Pyrolysis Technique ◽  
Chemical Spray Pyrolysis ◽  
Structural And Optical Properties ◽  
Optical Energy Gap ◽  
Optical Energy ◽  
Chemical Spray Pyrolysis Technique ◽  
Chemical Spray

Thin films of pure tin mono-sulfide SnS and tin mono-sulfide for (1,2,3,4)% fluorine SnS:F with Thicknesses of (0.85 ±0.05) ?m and (0.45±0.05) ?m respectively were prepared by chemical spray pyrolysis technique. the effect of doping of F on structural and optical properties has been studied. X-Ray diffraction analysis showed that the prepared films were polycrystalline with orthorhombic structure. It was found that doping increased the intensity of diffraction peaks. Optical properties of all samples were studied by recording the absorption and transmission spectrum in range of wave lengths (300-900) nm. The optical energy gap for direct forbidden transition and indirect allowed transition were evaluated It is found that for doping less than 2% the optical energy gap increases as the percentage of doping increases in the samples while for doping more than 2% the values of the optical energy gap decreases as the percentage of doping increases.

scholarly journals Laser induced plasma of cadmium oxide: structural, morphological and optical properties

2021 ◽  
Vol 2114 (1) ◽  
pp. 012012
Author(s):  
Tamara S. Hussein ◽  
Ala F. Ahmed
Keyword(s):  
Optical Properties ◽  
Energy Gap ◽  
Cadmium Oxide ◽  
X Ray Diffraction ◽  
Structural And Optical Properties ◽  
Optical Energy Gap ◽  
X Ray ◽  
Laser Induced Plasma ◽  
Atomic Force ◽  
Doping Ratio

Abstract In this study, the effect of grafting with Iron (Fe) ratios (0.1, 0.3 and 0.5) on the structural and optical properties of cadmium oxide films (CdO) was studied, as these films were prepared on glass bases using the method of pulse laser deposition (PLD). The crystallization nature of the prepared films was examined by X-ray diffraction technique (XRD), which showed that the synthesis of the prepared films is polycrystalline, and Atomic Force Microscope (AFM) images also showed that the increased vaccination with Iron led to an increase in the crustal size ratio and a decrease in surface roughness, The absorption coefficient was calculated and the optical energy gap for the prepared thin films. It was found the absorption decreases and the energy gap decreases with the increase of doping ratio.

scholarly journals Optical properties of AlN layers obtained by magnetron sputtering

2018 ◽  
Vol 36 (4) ◽  
pp. 717-721
Author(s):  
Piotr Potera ◽  
Grzegorz Wisz ◽  
Łukasz Szyller
Keyword(s):  
Refractive Index ◽  
Optical Properties ◽  
Magnetron Sputtering ◽  
Energy Gap ◽  
Optical Measurements ◽  
Transmission Spectra ◽  
Glass Substrates ◽  
Different Content

AbstractThe growth of AlN layers on glass substrates using magnetron sputtering method was performed and the grown layers were subjected to optical measurements. Transmission spectra of the layers grown at different content of N2 in the atmosphere were obtained. The transmission spectra as well as energy gap depended on N2 content. The annealing of the layers in air led to transmission changes and influenced energy gap and refractive index values.

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