First-principles calculations to investigate structural, electronic and optical properties of (ZnSe)n/(ZnTe)n superlattices

2020 ◽  
Author(s):  
Messaoud Caid
Keyword(s):  
Optical Properties ◽  
First Principles ◽  
Density Functional ◽  
Correlation Energy ◽  
Local Density ◽  
Full Potential ◽  
First Principles Calculations ◽  
Electronic And Optical Properties ◽  
Lmto Method ◽  
Binary Compounds

An investigation into the structural, electronic and optical properties of superlattices(SLs) (ZnSe)n/(ZnTe)n was conducted using first principles calculations based on density functional theory (DFT). The total energies were calculated within the full-potential linear muffin-tin orbital (FP-LMTO) method augmented by a plane-wave basis (PLW), implemented in LmtART 7.0 code. The effects of the approximations to the exchange-correlation energy were treated by the local density approximation (LDA). The ground state properties of (ZnSe)n/(ZnTe)n binary compounds are determined and compared with the available data. It is found that the superlattice (n-n: 1-1, 2-2 and 3-3) band gaps vary depending on the layers used. The optical constants, including the dielectric function ε(w), the refractive index n(w) and the reflectivity R(w), are calculated for radiation energies up to 35eV.

scholarly journals Effect of pressure on structural, electronic and optical properties of SrF2: a first principles study

2018 ◽  
Vol 64 (1) ◽  
pp. 94 ◽  
Author(s):  
D.M. Hoat ◽  
J.F. Rivas Silva ◽  
A. Méndez Blas ◽  
J.J. Ríos Rámirez
Keyword(s):  
Optical Properties ◽  
First Principles ◽  
Density Functional ◽  
Correlation Energy ◽  
Refraction Index ◽  
Energy Functional ◽  
Wide Energy Range ◽  
Full Potential ◽  
Electronic And Optical Properties ◽  
Wide Energy

We report results of the first principles calculations of structural, electronic and optical properties of SrF2 under pressure, performed using full-potential linearized augmented plane wave (FP-LAPW) method based on density functional theory as implemented on WIEN2k code. The exchange-correlation energy functional has been treated with generalised gradient approximation (GGA) for structural optimization,while the Tran-Blaha modifed Becke-Johnson potential (TB-mBJ) has been employed for electronic and optical calculations. Our results show that the first transition from Fm3m to Pnam structure occurs at 5.8 GPa and the second transformation from Pnam to P63/mmc structure takes place at 24.8 GPa. Our electronic calculation indicates an indirect gap X-Γ of Fm3m structure, direct gap Γ-Γ of Pnam structure and indirect gap Γ-K of P63/mmc structure. We do not observe the metallization up to 210 GPa. The linear optical properties such as absorption coefficient, reflectivity, refraction index, conductivity and energy loss function have been derived from calculated complex dielectric function for a wide energy range of 0-50 eV and pressure up to 50 GPa, and analyzed in detail.

scholarly journals First-principles calculations to investigate structural, electronic and optical properties of (AlSb)m/(GaSb)n superlattices

2020 ◽  
Vol 38 (2) ◽  
pp. 320-327
Author(s):  
M. Caid ◽  
D. Rached
Keyword(s):  
Optical Properties ◽  
First Principles ◽  
Density Functional ◽  
Local Density ◽  
Orbital Method ◽  
Full Potential ◽  
Functional Theory ◽  
Electronic And Optical Properties ◽  
The Density Functional Theory ◽  
Direct Band

AbstractThe structural, electronic and optical properties of (AlSb)m/(GaSb)n (m-n: 1-1, 2-2, 1-3 and 3-1) superlattices are investigated within the density functional theory (DFT) by using the last version of the first principles full potential linear muffin tin orbital method (FP-LMTO) as implemented in LmtART 7.0 code. The exchange and correlation potential is treated by the local density approximation (LDA) for the total energy calculations. Our calculations of the band structure show that the superlattices (n ≠ 1) have a direct band gap Γ-Γ. The optical constants, including the dielectric function ϵ(w), the refractive index n(w) and the reflectivity R(w) are calculated and discussed.

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.

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.

First-principles investigation of the structural, elastic, electronic, and optical properties of semiconducting AgBr1–xIx (0 ≤ x ≤ 1) ternary alloys in rock-salt and zinc blende structures

2020 ◽  
Vol 98 (9) ◽  
pp. 834-848
Author(s):  
H. Rekab-Djabri ◽  
Mohamed Drief ◽  
Manal M. Abdus Salam ◽  
Salah Daoud ◽  
F. El Haj Hassan ◽  
...  
Keyword(s):  
Optical Properties ◽  
Band Gap ◽  
Rock Salt ◽  
Density Functional ◽  
Local Density ◽  
Ternary Alloys ◽  
Full Potential ◽  
Zinc Blende ◽  
Lmto Method ◽  
Direct Band

In this work, first principle calculations of the structural, electronic, elastic, and optical properties of novel AgBr1–xIx ternary alloys in rock-salt (B1) and zinc-blende (B3) structures are presented. The calculations were performed using the full-potential linear muffin-tin orbital (FP-LMTO) method within the framework of the density functional theory (DFT). The exchange and correlation potentials were treated according to the local density approximation (LDA). The lattice constants for the B1 and B3 phases versus iodide concentration (x) were found to deviate slightly from the linear relationship of Vegard’s law. The calculated electronic properties showed that AgBr1–xIx alloys in the B3 structure have a direct band gap (Γ – Γ) for all concentrations of x, which means that they can be used in long-wavelength optoelectronic applications, while in the B1 structure they have an indirect (Γ – R) band gap. The elastic constants Cij, shear modulus G, Young’s modulus E, Poisson’s ratio ν, index of ductility B/G, sound velocities vt, vl, and vm, and Debye temperature θD were also reported and analyzed. By incorporating the basic optical properties, we discussed the dielectric function, refractive index, optical reflectivity, absorption coefficient, and optical conductivity in terms of incident photon energy up to 13.5 eV. The present results were found to be in good agreement with the available experimental and other theoretical results.

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.

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.

scholarly journals Electronic and optical properties of Ba(1-x)Ca(x) TiO3 and Ba(1-x)Sr(x)TiO3

2018 ◽  
Vol 3 (1) ◽  
Author(s):  
A. Belaaraj ◽  
O. Tahiri ◽  
S. Kassou ◽  
R. El Mrabet
Keyword(s):  
Optical Properties ◽  
First Principles ◽  
Density Functional ◽  
Low Energy ◽  
Band Gaps ◽  
First Principles Calculations ◽  
Functional Theory ◽  
Electronic And Optical Properties ◽  
Densities Of States ◽  
Indirect Band Gap

The effect of Ca and Sr-doping on the structural electronic and optical properties of the cubic Ba1-xCaxTiO3 and Ba1-xSrxTiO3 (x=0.4, 0.6) mixed crystals was investigated using first-principles calculations based on density functional theory (DFT). The calculated band structures based on the optimized geometry of the cell for the solid solutions show an indirect band gap character at M-points, with low energy dispersion along height symmetry directions in the Brillouin zone. The band gaps increase with Ca and Sr concentrations. The total and partial densities of states were analyzed to examine the contribution of different orbitals to the maximum of valence band and the minimum of the conduction band. The optical properties such as reflectivity, energy loss, refractive index and extinction coefficient were studied. #DFT_calculations #band_gap #density_of_states #optical_properties

scholarly journals Electronic and optical properties of Janus ZrSSe by density functional theory

RSC Advances ◽  
2019 ◽  
Vol 9 (70) ◽  
pp. 41058-41065 ◽  
Author(s):  
Tuan V. Vu ◽  
Hien D. Tong ◽  
Duy Phu Tran ◽  
Nguyen T. T. Binh ◽  
Chuong V. Nguyen ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Optical Properties ◽  
First Principles ◽  
Density Functional ◽  
First Principles Calculations ◽  
Functional Theory ◽  
Electronic And Optical Properties

In the present work, we investigate systematically the electronic and optical properties of Janus ZrSSe using first-principles calculations.

ELECTRONIC AND OPTICAL PROPERTIES OF BaO, BaS, BaSe, BaTe AND BaPo COMPOUNDS UNDER HYDROSTATIC PRESSURE

2009 ◽  
Vol 23 (26) ◽  
pp. 3065-3079 ◽  
Author(s):  
S. DRABLIA ◽  
H. MERADJI ◽  
S. GHEMID ◽  
N. BOUKHRIS ◽  
B. BOUHAFS ◽  
...  
Keyword(s):  
Optical Properties ◽  
Dielectric Function ◽  
Imaginary Part ◽  
Density Functional ◽  
Energy Gap ◽  
Electronic Band Structure ◽  
Local Density ◽  
Full Potential ◽  
Electronic Band ◽  
Electronic And Optical Properties

We have performed first-principle full-potential (linear) augmented plane wave plus local orbital calculations (FP-L/APW + l0) with density functional theory (DFT) in local density approximation (LDA) and generalized gradient approximation (GGA), with the aim to determine and predict the electronic and optical properties of rocksalt BaO , BaS , BaSe , BaTe and BaPo compounds. First we present the main features of the electronic properties of these compounds, where the electronic band structure shows that the fundamental energy gap is indirect (Γ–X) for all compounds except for BaO which is direct (X–X). The different interband transitions have been determined from the imaginary part of the dielectric function. The real and imaginary parts of the dielectric function and the reflectivity are calculated. We have presented the assignment of the different optical transitions existing in these compounds from the imaginary part of the dielectric function spectra with respect to their correspondence in the electronic band. We have also calculated the pressure and volume dependence of the optical properties for these compounds.

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