scholarly journals Structural, Electronic and Optical Properties of Cubic Perovskite Cspbx3 (X= Br, Cl and I)

2020 ◽  
Vol 8 (1) ◽  
pp. 23-28
Author(s):  
Aawzad A. Abdulkareem ◽  
Sarkawt A. Sami ◽  
Badal H. Elias
Keyword(s):  
Optical Properties ◽  
Density Functional ◽  
Structural Parameters ◽  
Plane Waves ◽  
Experimental Studies ◽  
Visible Region ◽  
Electromagnetic Spectrum ◽  
Generalized Gradient ◽  
Electronic And Optical Properties ◽  
Low Energies

Plane waves with norm conserving pseudopotentials (PW-PP) method in conjunction with density functional theory (DFT) frame work have been used to investigate structural, electronic and optical properties of lead-halide cubic perovskite CsPbX3 (X=Br, Cl and I). The generalized gradient approximation (GGA), specifically Perdew-Burke-Ernzerhof (PBE) flavor, has been chosen to treat the exchange correlation term of Kohn-Sham equation. Structural parameters are comparable with other theoretical and experimental studies. In spite of good agreement of our band gap values  with other theoretical works, however, they were not comparable when compared to the experimental  values due to the well-known problem of Eg value underestimation of DFT. To update the  value, we have used GW method as a self-consistent quasiparticle method on energies and wave functions and indeed they have been improved. Optical properties have been calculated using density functional perturbation theory (DFPT). Our results show that CsPbX3 (X=Br, Cl, I) has maximum response to the electromagnetic spectrum at low energies (visible region) but minimum response at high energies.

STRUCTURAL, ELECTRONIC AND OPTICAL PROPERTIES OF MgSxSe1-x, MgSxTe1-x AND MgSexTe1-x (0 ≤x ≤1) ALLOYS FROM FIRST PRINCIPLES

2012 ◽  
Vol 26 (17) ◽  
pp. 1250098 ◽  
Author(s):  
A. SAJID ◽  
S. M. ALAY-E-ABBAS ◽  
A. AFAQ ◽  
A. SHAUKAT
Keyword(s):  
Optical Properties ◽  
First Principles ◽  
Density Functional ◽  
Structural Parameters ◽  
Ternary Alloys ◽  
Full Potential ◽  
Generalized Gradient ◽  
Volume Deformation ◽  
Electronic Band ◽  
Electronic And Optical Properties

First principles total energy calculations have been performed using full potential linear augmented plane wave method (FP-LAPW) within density functional theory to study the structural, electronic and optical properties of MgS x Se 1-x, MgS x Te 1-x and MgSe x Te 1-x alloys in the rock salt crystallographic phase. The generalized gradient approximation parameterization scheme has been used for calculating the ground state structural parameters and their deviation from the Vegard's law has been discussed. Full relativistic electronic band structures and density of states have been calculated to study the electronic properties of the end binary compounds and ternary alloys MgS x Se 1-x, MgS x Te 1-x and MgSe x Te 1-x (0.25 < x < 0.75). Optical bowing for these semiconductor alloys has been discussed in term of volume deformation, electronegativity and structural relaxation. Optical properties of the binary and ternary magnesium chalcogenides have been calculated in terms of the complex dielectric function and the results are compared with available theoretical and experimental data.

First principles calculations of structural, electronic and optical properties of InN compound

2015 ◽  
Vol 29 (05) ◽  
pp. 1550028 ◽  
Author(s):  
R. Graine ◽  
R. Chemam ◽  
F. Z. Gasmi ◽  
R. Nouri ◽  
H. Meradji ◽  
...  
Keyword(s):  
Optical Properties ◽  
Band Structure ◽  
Density Functional ◽  
Local Density ◽  
Indium Nitride ◽  
Alternative Form ◽  
Full Potential ◽  
Generalized Gradient ◽  
Pressure Derivative ◽  
Electronic And Optical Properties

We carried out ab initio calculations of structural, electronic and optical properties of Indium nitride ( InN ) compound in both zinc blende and wurtzite phases, using the full-potential linearized augmented plane wave method (FP-LAPW), within the framework of density functional theory (DFT). For the exchange and correlation potential, local density approximation (LDA) and generalized gradient approximation (GGA) were used. Moreover, the alternative form of GGA proposed by Engel and Vosko (EV-GGA) and modified Becke–Johnson schemes (mBJ) were also applied for band structure calculations. Ground state properties such as lattice parameter, bulk modulus and its pressure derivative are calculated. Results obtained for band structure of these compounds have been compared with experimental results as well as other first principle computations. Our results show good agreement with the available data. The calculated band structure shows a direct band gap Γ → Γ. In the optical properties section, several optical quantities are investigated; in particular we have deduced the interband transitions from the imaginary part of the dielectric function.

scholarly journals Structural, Optical, and Magnetic Properties of Gd Doped CdTe Quantum Dots for Magnetic Imaging Applications

2022 ◽  
Author(s):  
Shanmugapriya V ◽  
Bharathi S ◽  
Esakkinaveen D ◽  
Arunpandiyan S ◽  
Selvakumar B ◽  
...  
Keyword(s):  
Optical Properties ◽  
Plane Waves ◽  
Theoretical Data ◽  
Blue Shift ◽  
Generalized Gradient ◽  
Electronic And Optical Properties ◽  
Magnetic Imaging ◽  
Optical Applications ◽  
Indirect Band Gap ◽  
Pseudo Potential

Abstract The effect of pressure on the electronic and optical properties of SrAl2O4 up to 25 GPa was studied by means of the pseudo-potential plane waves method within the generalized gradient approximation for exchange and correlation. The calculated lattice parameters are consistent with available experimental and theoretical data. By analyzing the electronic and optical properties, the pressure dependences of the electronic structures and optical constants were investigated. The band structures show an indirect band gap for this compound and the calculated band gaps expend with increasing pressure. Meanwhile, the optical properties including the dielectric spectra, absorption coefficient spectra, reflectivity, and the real part of the refractive index spectra in the low energy range have a blue shift. Given this, the optical properties of SrAl2O4 could be tuned by changing pressure to some degree, which is beneficial to the optical applications.

Structural Electronic and Optical Properties of MgO, CaO and SrO Binary Compounds: Comparison Study

2016 ◽  
Vol 257 ◽  
pp. 123-126 ◽  
Author(s):  
Salima Labidi ◽  
Jazia Zeroual ◽  
Malika Labidi ◽  
Kalthoum Klaa ◽  
Rachid Bensalem
Keyword(s):  
Optical Properties ◽  
Band Gap ◽  
Density Functional ◽  
Local Density ◽  
Alternative Form ◽  
Full Potential ◽  
Generalized Gradient ◽  
Electronic And Optical Properties ◽  
Optical Dielectric Constant ◽  
Reported Data

First-principles calculations for electronic and optical properties under pressure effect of MgO, SrO and CaO compounds in the cubic structure, using a full relativistic version of the full-potential augmented plane-wave (FP-LAPW) method based on density functional theory, within the local density approximation (LDA) and the generalized gradient approximation (GGA), have been reported. Furthermore, band structure calculations have been investigated by the alternative form of GGA proposed by Engel and Vosko (GGA-EV) and modified by Becke-Johnson exchange correlation potential (MBJ-GGA). All calculated equilibrium lattices, bulk modulus and band gap at zero pressure are find in good agreement with the available reported data. The pressure dependence of band gap and the static optical dielectric constant are also investigated in this work.

scholarly journals First–Principles Investigation of the Structural, Elastic, Electronic, and Optical Properties of α– and β–SrZrS3: Implications for Photovoltaic Applications

Materials ◽  
2020 ◽  
Vol 13 (4) ◽  
pp. 978
Author(s):  
Henry Igwebuike Eya ◽  
Esidor Ntsoenzok ◽  
Nelson Y. Dzade
Keyword(s):  
Optical Properties ◽  
First Principles ◽  
Density Functional ◽  
Visible Region ◽  
Charge Carriers ◽  
Band Gaps ◽  
Strong Light ◽  
Electronic And Optical Properties ◽  
Optical Absorbance ◽  
Effective Masses

Transition metal perovskite chalcogenides are attractive solar absorber materials for renewable energy applications. Herein, we present the first–principles screened hybrid density functional theory analyses of the structural, elastic, electronic and optical properties of the two structure modifications of strontium zirconium sulfide (needle–like α–SrZrS3 and distorted β–SrZrS3 phases). Through the analysis of the predicted electronic structures, we show that both α– and β–SrZrS3 materials are direct band gaps absorbers, with calculated band gaps of 1.38, and 1.95 eV, respectively, in close agreement with estimates from diffuse–reflectance measurements. A strong light absorption in the visible region is predicted for the α– and β–SrZrS3, as reflected in their high optical absorbance (in the order of 105 cm−1), with the β–SrZrS3 phase showing stronger absorption than the α–SrZrS3 phase. We also report the first theoretical prediction of effective masses of photo-generated charge carriers in α– and β–SrZrS3 materials. Predicted small effective masses of holes and electrons at the valence, and conduction bands, respectively, point to high mobility (high conductivity) and low recombination rate of photo-generated charge carriers in α– and β–SrZrS3 materials, which are necessary for efficient photovoltaic conversion.

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 Prediction of electronic and optical properties for Zn1-xCdxSeyTe1-y quaternary alloys: First-principles study

2021 ◽  
Vol 67 (4 Jul-Aug) ◽  
pp. 041001
Author(s):  
K. Benchikh ◽  
M. Benchehima ◽  
H. A. Bid ◽  
A. Chabane Chaouche
Keyword(s):  
Optical Properties ◽  
Density Functional ◽  
Energy Gap ◽  
Local Density ◽  
Quaternary Alloy ◽  
Full Potential ◽  
Generalized Gradient ◽  
Quaternary Alloys ◽  
Electronic And Optical Properties ◽  
The Density Functional Theory

In the present work, the density functional theory (DFT) was performed for the investigation of the structural, electronic and optical properties of the Zn1-xCdxSeyTe1-y quaternary alloys using the full potential linearized augmented plane wave (FP-LAPW) method. For the calculations of the structural properties we have used the Perdew-Burke-Ernzerhof generalized gradient approximation (GGA-PBEsol). On other hand, the electronic properties have been computed within the local density approximation (LDA) in adding to the Tran-Blaha modified Becker-Johnson (TB-mBJ) approach. Our results indicate that the lattice constant, as well as the bulk modulus and the energy gap for the Zn1-xCdxSeyTe1-y quaternary show almost linear variations on the concentration x (0.125≤x≤0.875). In addition, the simulated band structures for theZn1-xCdxSeyTe1-y quaternary exhibits a direct-gap for all concentrations. Moreover, low bowing parameters are observed. Also, some interesting optical properties such as dielectric constant, refractive index, extinction coefficient, absorption coefficient and reflectivity have been calculated by using the TB-mBJ method.  The results of our computations shows that theZn1-xCdxSeyTe1-y quaternary alloy is a promissing candidate for optoelectronic applications. It is noteworthy that the present work is the first theoretical study of the quaternary of interest using the FP-LAPW calculations.

scholarly journals Opto-Electronic Investigation of Rubidium Based Fluoro-Perovskite for Low Birefringent Lens Materials

2017 ◽  
Vol 1 (1) ◽  
pp. 37-48
Author(s):  
M. A. Iqbal ◽  
N. Erum
Keyword(s):  
Optical Properties ◽  
Density Functional ◽  
Structural Parameters ◽  
First Principles Calculation ◽  
Partial Density ◽  
Generalized Gradient ◽  
Contour Maps ◽  
Data Assessment ◽  
Method Optimization ◽  
Quantum Mechanical Effects

In this communication, systematic first principles calculation has been scrutinize to evaluate bonding nature, structural, electronic, and optical properties of RbHgF3. The findings are based on total energy calculations where Khon Sham (KS) equation is solved by means of density functional theory (FP-LAPW) method. Optimization of structural parameters is done with variety of approximations, which corroborates through comparison with available experimental data. Assessment of band profile through GGA plus Trans-Blaha modified Becke–Johnson (TB-mBJ) potential highlights underestimation of bandgap with traditional Generalized Gradient approximations. Specific contribution of particular states on electronic properties is investigated by means of total and partial density of states while contour maps of electron density are used to sightsee bonding character and it is evaluated that emphasized compound is (M-Γ) indirect bandgap material with mixed ionic and covalent bonding character. Additionally attention is paid to absorption and reflection spectra of RbHgF3fluoroperovskite by reconnoitering optical properties, which shows extensive absorption and reflection in high frequency regions. Expectantly, current study would benchmark various quantum mechanical effects, which must be taken into account to understand and utilize RbHgF3 in fabricating practical devices.

DFT study of SmXO3 (X = Al and Co) for elastic, mechanical and optical properties

2018 ◽  
Vol 32 (32) ◽  
pp. 1850362 ◽  
Author(s):  
A. Afaq ◽  
Abu Bakar ◽  
Sajid Anwar ◽  
Waheed Anwar ◽  
Fazal-e-Aleem
Keyword(s):  
Optical Properties ◽  
Poisson’S Ratio ◽  
Density Functional ◽  
Structural Parameters ◽  
Poisson's Ratio ◽  
Published Data ◽  
Generalized Gradient ◽  
Elastic Parameters ◽  
Functional Theory ◽  
Anisotropic Factor

The first-principles study of cubic perovskites SmXO3 (X = Al and Co) for elastic, mechanical and optical properties is done in the framework of density functional theory (DFT). Optimized structural parameters are obtained first to find mechanical and optical properties of the materials. These obtained structural parameters are in accordance with the published data. The cubic elastic parameters C[Formula: see text], C[Formula: see text] and C[Formula: see text] are then calculated by using generalized gradient approximation (GGA) as an exchange correlation functional in Kohn–Sham equations. Poisson’s ratio, shear modulus, Young’s modulus and anisotropic factor are deduced from these elastic parameters. These compounds are found to be elastically anisotropic and SmAlO3 is brittle while SmCoO3 is ductile. Their covalent nature is also discussed by using Poisson’s ratio. In addition, optical properties like absorption coefficient, extinction coefficient, energy loss function, dielectric function, refractive index, reflectivity and optical conductivity are studied. This study predicts that SmAlO3 and SmCoO3 are suitable for optoelectronic devices.

Investigation of optical properties of Zn1-xVxO (x = 0.0, 0.125, 0.25, 0.5) by first principles calculations

2014 ◽  
Vol 28 (31) ◽  
pp. 1450243
Author(s):  
R. Taghavi Mendi ◽  
S. M. Elahi ◽  
M. R. Abolhassani
Keyword(s):  
Refractive Index ◽  
Optical Properties ◽  
Dielectric Function ◽  
First Principles ◽  
Density Functional ◽  
Full Potential ◽  
First Principles Calculations ◽  
Generalized Gradient ◽  
Electron Model ◽  
Low Energies

In this paper, some optical properties of Zn 1-x V x O (0 ≤ x ≤ 0.5) such as real and imaginary part of dielectric function, energy loss function, plasmon energies and refractive index are investigated by first principles calculations. The calculations were performed in density functional theory (DFT) framework using full potential linear augmented plane wave (FP-LAPW) and generalized gradient approximation (GGA). Analysis of dielectric function shows that by substituting V instead of Zn in Zn 1-x V x O , static dielectric function, absorption and anisotropy at low energies are increased. The investigations show that V doping in ZnO affects plasmon energies. The plasmon energies have been compared with free electron model. The calculated plasmon energy for pure ZnO is nearly close to other works. The refractive index at low energies is increased significantly, so that V -doped ZnO can be used as a high refractive material.

Sign in / Sign up

Export Citation Format

Share Document