Structural, electronic and optical properties of LiNbO3 using GGA-PBE and TB-mBJ functionals: A DFT study

2018 ◽  
Vol 32 (14) ◽  
pp. 1850168 ◽  
Author(s):  
M. Arshad Javid ◽  
Zafar Ullah Khan ◽  
Zahid Mehmood ◽  
Azeem Nabi ◽  
Fayyaz Hussain ◽  
...  
Keyword(s):  
Refractive Index ◽  
Optical Properties ◽  
Lithium Niobate ◽  
Dielectric Function ◽  
Lithium Niobate Crystal ◽  
Structural Parameters ◽  
Dft Method ◽  
Bandgap Energy ◽  
Electronic And Optical Properties ◽  
Experimental Values

In the present work, first-principles calculations were performed to obtain the structural, electronic and optical properties of lithium niobate crystal using two exchange-correlation functionals (GGA-PBE and TB-mBJ). The calculated structural parameters were very close to the experimental values. TB-mBJ functional was found to be good when compared to LDA and GGA functionals in case of bandgap energy of 3.715 eV of lithium niobate. It was observed that the upper valence and lower conduction bands consist mainly the O-2p and Nb-4[Formula: see text] states, respectively. Furthermore, calculations for real and imaginary parts of frequency-dependent dielectric function [Formula: see text] of lithium niobate crystal were performed using TD-DFT method. The ordinary refractive index n[Formula: see text], extraordinary refractive index n[Formula: see text], its birefringence and absorption peaks in imaginary dielectric function [Formula: see text] were also calculated.

scholarly journals First principles study of structure, electronic and optical properties of Y3Fe5O12 in cubic and trigonal phases

2015 ◽  
Vol 33 (1) ◽  
pp. 169-174 ◽  
Author(s):  
Shen Tao ◽  
Hu Chao ◽  
Dai Hailong ◽  
Yang Wenlong ◽  
Liu Hongchen ◽  
...  
Keyword(s):  
Refractive Index ◽  
Optical Properties ◽  
Energy Loss ◽  
First Principles ◽  
Structural Parameters ◽  
Band Gaps ◽  
First Principles Calculations ◽  
Electronic And Optical Properties ◽  
Direct Band ◽  
Experimental Values

AbstractFirst principles calculations have been performed to investigate the structure, electronic and optical properties of Y3Fe5O12. Both the cubic and trigonal phases have been considered in our calculation. The calculated structural parameters are slightly larger than the experimental values. The band structures show that Y3Fe5O12 in cubic and trigonal phases have direct band gaps of 0.65 and 0.17 eV. The calculations of dielectric function, absorption, extinction coefficient, refractive index, energy loss function and reflectivity are presented.

First-principles study of electronic and optical properties of Sr2ZnN2 under pressure

2016 ◽  
Vol 30 (10) ◽  
pp. 1650139
Author(s):  
Kai Liang ◽  
Hui Zhao
Keyword(s):  
Refractive Index ◽  
Optical Properties ◽  
Electronic Structure ◽  
Dielectric Function ◽  
First Principles ◽  
Density Functional ◽  
Optical Transition ◽  
Dft Method ◽  
Structural Parameter ◽  
Generalized Gradient

First-principles calculations of ternary Sr2ZnN2 compound using density-functional theory (DFT) method within the generalized gradient approximation (GGA) has been performed. Based on the optimized structural parameter, the electronic properties and optical properties have been researched. The calculated lattice constants are in agreement with the experimental and theoretical results. The electronic structure have been investigated throughout the calculated band structure and density of states (DOS). It shows that this compound belongs to the semiconductors with a band gap of about 0.775[Formula: see text]eV. Furthermore, in order to clarify the optical transition of this material, the optical properties such as dielectric function, absorption coefficient, reflectivity, refractive index and energy-loss function at different pressures of 0, 10 and 20[Formula: see text]GPa in the energy range 0–20[Formula: see text]eV were performed and discussed. It shows that Sr2ZnN2 is a strong anisotropy material and the imaginary part of dielectric function shifts to higher energy region as the pressure increases. The square of calculated static refractive index is equal to static dielectric function, which corresponds to the theory formula. In conclusion, pressure is a effective method to change the electronic structure and optical properties.

scholarly journals Polymer Composites with 0.98 Transparencies and Small Optical Energy Band Gap Using a Promising Green Methodology: Structural and Optical Properties

Polymers ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 1648
Author(s):  
Muaffaq M. Nofal ◽  
Shujahadeen B. Aziz ◽  
Jihad M. Hadi ◽  
Wrya O. Karim ◽  
Elham M. A. Dannoun ◽  
...  
Keyword(s):  
Refractive Index ◽  
Optical Properties ◽  
Polymer Composites ◽  
Amorphous Phase ◽  
Absorption Edge ◽  
Complex Form ◽  
Bandgap Energy ◽  
Optical Parameters ◽  
Visible Spectroscopy ◽  
Uv Visible

In this work, a green approach was implemented to prepare polymer composites using polyvinyl alcohol polymer and the extract of black tea leaves (polyphenols) in a complex form with Co2+ ions. A range of techniques was used to characterize the Co2+ complex and polymer composite, such as Ultraviolet–visible (UV-Visible) spectroscopy, Fourier transform infrared spectroscopy (FTIR), and X-ray diffraction (XRD). The optical parameters of absorption edge, refractive index (n), dielectric properties including real and imaginary parts (εr, and εi) were also investigated. The FRIR and XRD spectra were used to examine the compatibility between the PVA polymer and Co2+-polyphenol complex. The extent of interaction was evidenced from the shifts and change in the intensity of the peaks. The relatively wide amorphous phase in PVA polymer increased upon insertion of the Co2+-polyphenol complex. The amorphous character of the Co2+ complex was emphasized with the appearance of a hump in the XRD pattern. From UV-Visible spectroscopy, the optical properties, such as absorption edge, refractive index (n), (εr), (εi), and bandgap energy (Eg) of parent PVA and composite films were specified. The Eg of PVA was lowered from 5.8 to 1.82 eV upon addition of 45 mL of Co2+-polyphenol complex. The N/m* was calculated from the optical dielectric function. Ultimately, various types of electronic transitions within the polymer composites were specified using Tauc’s method. The direct bandgap (DBG) treatment of polymer composites with a developed amorphous phase is fundamental for commercialization in optoelectronic devices.

Growth and Optical Properties of Near-Stoichiometric Ni2+-Doped Lithium Niobate Crystal

2008 ◽  
Vol 28 (1) ◽  
pp. 138-142
Author(s):  
张嗣春 Zhang Sichun ◽  
夏海平 Xia Haiping ◽  
王金浩 Wang Jinhao ◽  
张约品 Zhang Yuepin
Keyword(s):  
Optical Properties ◽  
Lithium Niobate ◽  
Lithium Niobate Crystal

Electronic and Optical Properties of Indium Selenide Nanosheet Using First-Principle Calculations

2019 ◽  
Vol 11 (11) ◽  
pp. 1148-1154
Author(s):  
Hamza A. Mezerh ◽  
Kadhim J. Kadhim ◽  
Hamad Rahman Jappor
Keyword(s):  
Refractive Index ◽  
Optical Properties ◽  
Density Functional ◽  
Visible Region ◽  
High Refractive Index ◽  
Indium Selenide ◽  
Experimental Investigations ◽  
Ultraviolet Region ◽  
Electronic And Optical Properties ◽  
Index Value

Density functional theory (DFT) have been used to examine the electronic and optical, properties of two-dimensional (2D) indium selenide (InSe) nanosheet. Our calculations indicate that the energy band gap of InSe is indirect and equal to 1.53 eV. It can be seen that for the pristine case, the majority and minority density of state (DOS) are fully symmetric. The optical properties are considered up to 36 eV. Our results established that the absorption starts in the visible region, while the peaks in the ultraviolet region. The refractive index value is 1.84 at zero photon energy limit and increase to 2.31. The high refractive index allows this nanosheet to be utilized as an internal layer coating between the substrate and the ultraviolet absorbing layer. Additionally, we observed that the gained optical properties of InSe nanosheet are in the ultraviolet range and the results are significant. It is expected that from these calculations to provide useful information for further experimental investigations of InSe nanosheet.

scholarly journals Structural, electronic and optical properties of 2,5-dichloro-p-xylene: experimental and theoretical calculations using DFT method

RSC Advances ◽  
2017 ◽  
Vol 7 (3) ◽  
pp. 1401-1412 ◽  
Author(s):  
G. Venkatesh ◽  
M. Govindaraju ◽  
C. Kamal ◽  
P. Vennila ◽  
S. Kaya
Keyword(s):  
Optical Properties ◽  
Vibrational Spectra ◽  
Theoretical Calculations ◽  
Dft Method ◽  
Electronic And Optical Properties ◽  
Ft Ir ◽  
Ft Raman

The vibrational spectra including FT-IR and FT-Raman for 2,5-dichloro-p-xylene (DCPX) have been recorded.

Electronic, optical and photocatalytic properties of three-layer perovskite Dion–Jacobson phase CsBa2M3O10(M = Ta, Nb): a DFT study

RSC Advances ◽  
2015 ◽  
Vol 5 (108) ◽  
pp. 88725-88735 ◽  
Author(s):  
Ehsan Zahedi ◽  
Mirabbos Hojamberdiev ◽  
Maged F. Bekheet
Keyword(s):  
Optical Properties ◽  
Uv Light ◽  
Dft Method ◽  
Dft Study ◽  
Photocatalytic Properties ◽  
Electronic And Optical Properties

This work discloses structural, electronic and optical properties of three-layer perovskite Dion–Jacobson phase CsBa2M3O10(M = Ta, Nb) using the DFT method. These semiconductors are UV-light-responsive photocatalysts.

scholarly journals Structural, Electronic and Optical Properties of Stanene Doped Beryllium: A First Principle Study

2021 ◽  
pp. 32-40
Author(s):  
L. S. Taura ◽  
Isah Abdulmalik ◽  
A. S. Gidado ◽  
Abdullahi Lawal
Keyword(s):  
Refractive Index ◽  
Optical Properties ◽  
Fermi Level ◽  
Band Gap ◽  
Density Functional ◽  
Earth Metal ◽  
Dirac Cone ◽  
Electronic Band ◽  
Electronic And Optical Properties ◽  
Optical Applications

Stanene is a 2D hexagonal layer of tin with exceptional electronic and optical properties. However, the semiconductor applications of stanene are limited due to its zero band-gap. However, doping stanene could lead to a band gap opening, which could be a promising material for electronic and optical applications. In this work, optimized structure, electronic band structure, real and imaginary parts of the frequency-dependent dielectric function, electron loss function, and refractive index of stanene substitutionally doped with alkaline earth metal (beryllium) were analyzed using density functional theory (DFT) calculations as implemented in the quantum espresso and yambo suites. A pure stanene has a zero band gap energy, but with the inclusion of spin-orbit coupling in the electronic calculation of pure stanene, the band-gap is observed to open up by 0.1eV. Doping stanene with beryllium opens the band-gap and shifts the Dirac cone from the Fermi level, the band gap opens by 0.25eV, 0.55eV, and 0.8eV when the concentration of Beryllium is 12.5%, 25%, and 37.5% respectively. The Dirac cone vanished when the concentration of the dopant was increased to 50%.  The Fermi level is shifted towards the valence band edge indicating a p-type material. The material absorption shows that SnBe absorption ranges in the visible to the ultraviolet region, The refractive index in stanene doped beryllium (SnBe) was found to be higher than that of pristine stanene, the highest refractive index was 9.2 at SnBe25%. In a nutshell, the results indicate that stanene can be a good material for electronic and optical applications if doped with beryllium.

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