First principle investigations of the optical properties of Zn1-xMgxS, Zn1-xMgxSe and Zn1-xMgxTe ternary alloys

2014 ◽  
Vol 28 (31) ◽  
pp. 1450221 ◽  
Author(s):  
M. Dadsetani ◽  
A. Zeinivand
Keyword(s):  
Optical Properties ◽  
Density Functional ◽  
Theoretical Calculations ◽  
Random Phase ◽  
Ternary Alloys ◽  
Optical Absorption Coefficient ◽  
Full Potential ◽  
Generalized Gradient ◽  
The Density Functional Theory ◽  
Ternary Semiconductor

Optical properties of Zn 1-x Mg x S , Zn 1-x Mg x Se and Zn 1-x Mg x Te (0 ≤ x ≤ 1) ternary semiconductor alloys are calculated using the full potential linearized augmented plane wave within the density functional theory. The exchange correlation potential is treated by the generalized gradient approximation (GGA) within Perdew et al. scheme. The real and imaginary parts of the dielectric function ε(ω), the refractive index n(ω), the extinction coefficient k(ω), the optical absorption coefficient α(ω), the reflectivity R(ω) and the electron energy loss function (EELS) are calculated within random phase approximation (RPA). Our results are compared with the previous theoretical calculations and available experimental data. Moreover, the interband transitions responsible for the structures seen in the spectra are specified. It is shown that, the chalcogen p states as initial and Zn 4s, Mg 3s, chalcogen d states as final states perform the major role in optical transitions.

AB INITIO STUDY OF STRUCTURAL, ELECTRONIC AND OPTICAL PROPERTIES OF MgxCd1-xX (X = S, Se, Te) ALLOYS

2012 ◽  
Vol 26 (30) ◽  
pp. 1250168 ◽  
Author(s):  
N. A. NOOR ◽  
A. SHAUKAT
Keyword(s):  
Optical Properties ◽  
Band Gap ◽  
Density Functional ◽  
Theoretical Calculations ◽  
Ternary Alloys ◽  
Full Potential ◽  
Generalized Gradient ◽  
Calculated Density ◽  
Electronic And Optical Properties ◽  
Direct Band

This study describes structural, electronic and optical properties of Mg x Cd 1-x X (X = S, Se, Te) alloys in the complete range 0≤x ≤1 of composition x in the zinc-blende (ZB) phase with the help of full-potential linearized augmented plane wave plus local orbitals (FP-LAPW+lo) method within density functional theory (DFT). In order to calculate total energy, generalized gradient approximation (Wu–Cohen GGA) has been applied, which is based on optimization energy. For electronic structure calculations, the corresponding potential is being optimized by Engel–Vosko GGA formalism. Our calculations reveal the nonlinear variation of lattice constant and bulk modulus with different concentration for the end binary and their ternary alloys, which slightly deviates from Vegard's law. The calculated band structures show a direct band gap for all three alloys with increasing order in the complete range of the compositional parameter x. In addition, we have discussed the disorder parameter (gap bowing) and concluded that the total band gap bowing is substantially influenced by the chemical (electronegativity) contribution. The calculated density of states (DOS) of these alloys is discussed in terms of contribution from various s-, p- and d-states of the constituent atoms and charge density distributions plots are analyzed. Optical properties have been presented in the form of the complex dielectric function ε(ω), refractive index n(ω) and extinction coefficient k(ω) as function of the incident photon energy, and the results have been compared with existing experimental data and other theoretical calculations.

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.

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.

Theoretical investigations of the structural, electronic and optical properties of Hg1−xCdxS alloys

2016 ◽  
Vol 30 (11) ◽  
pp. 1650173 ◽  
Author(s):  
S. Al-Rajoub ◽  
B. Hamad
Keyword(s):  
Optical Properties ◽  
Density Functional ◽  
Local Density ◽  
Ternary Alloys ◽  
Full Potential ◽  
Generalized Gradient ◽  
Metallic Behavior ◽  
Electronic And Optical Properties ◽  
Lattice Constants ◽  
Theoretical Investigations

The structural, electronic and optical properties of mercury cadmium sulfide (Hg[Formula: see text]Cd[Formula: see text]S) alloys with [Formula: see text] = 0.0, 0.25, 0.5, 0.75 are studied using density functional theory (DFT) within full-potential linearized augmented plane wave (FPLAPW) method. We used the local density approximation (LDA), the generalized gradient approximation (GGA), Hubbard-corrected functionals (GGA/LDA[Formula: see text]+[Formula: see text][Formula: see text]) and the modified Becke–Johnson (LDA/GGA)-mjb hybrid potentials to treat the exchange-correlation functional [Formula: see text]. We found that LDA functional predicts better lattice constants than GGA functional. Mercury sulfide (HgS) binary alloy was found to exhibit a semi-metallic behavior using all functional with an inverted band gap close to the experimental value. However, the hybrid functionals were more successful than LDA and GGA functionals to predict the correct electronic structure of Hg[Formula: see text]Cd[Formula: see text]S ternary alloys. The results of the electronic and optical band gaps are consistent for Hg[Formula: see text]Cd[Formula: see text]S ternary alloys.

Investigation of optoelectronic and thermoelectric properties of half-metallic BaRuO3 using DFT+U

2018 ◽  
Vol 07 (03) ◽  
pp. 1850018 ◽  
Author(s):  
A. Labdelli ◽  
A. Boukortt ◽  
S. Meskine ◽  
H. Abbassa ◽  
A. Zaoui
Keyword(s):  
Thermal Conductivity ◽  
Optical Properties ◽  
Density Functional ◽  
Theoretical Calculations ◽  
Coulomb Repulsion ◽  
Full Potential ◽  
Thermoelectric Efficiency ◽  
Generalized Gradient ◽  
Metallic Behavior ◽  
Half Metallic

We have studied the structural, electronic, magnetic, thermoelectric and optical properties of the half-metal BaRuO3 using the accurate full-potential linearized augmented plane wave (FP-LAPW) method based on the density functional theory (DFT). The generalized gradient approximation (GGA) was used to treat the exchange and correlation potential. The GGA[Formula: see text] approximation was also used to enhance the description of the electronic structure after calculating theoretically the Coulomb repulsion ([Formula: see text][Formula: see text]eV). The ferromagnetic (FM) phase of BaRuO3 is more stable. This result is in accordance with experimental and theoretical calculations. The calculated magnetic moments in BaRuO3 were found to arise especially from the Ru-4d state electrons. We have obtained the semiconductor gap (0.9[Formula: see text]eV) in spin-up while in spin down, the metal character was dominant, and therefore BaRuO3 has a half-metallic behavior. The thermoelectric efficiency was 0.12 at room temperature. Here we have considered only the electronic thermal conductivity, we have not included the lattice thermal conductivity. The relaxation time was assumed constant. The [Formula: see text] approximation was also used to analyze the optical properties by determining the complex dielectric function from which are derived the other parameters.

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.

First-Principles Studies of the Magnetic Properties of hcp Cr in Cr/Cu(111) and Cr/Ru(0001) Superlattices

2002 ◽  
Vol 721 ◽  
Author(s):  
G. Y. Guo
Keyword(s):  
First Principles ◽  
Density Functional ◽  
Recent Observation ◽  
Theoretical Calculations ◽  
Ferromagnetic State ◽  
Full Potential ◽  
Generalized Gradient ◽  
Plane Wave Method ◽  
Wide Range ◽  
Linearized Augmented Plane Wave

AbstractLatest first-principles density functional theoretical calculations using the generalized gradient approximation and highly accurate all-eleectron full-potential linearized augmented plane wave method, show that bulk hcp Cr would be a paramagnet and that no ferromagnetic state could be stabilized over a wide range of volume [1]. To understand the recent observation of the weakly ferromagnetic state of Cr in hcp Cr/Ru (0001) superlattices [2], the same theoretical calculations have been carried out for the hcp Cr3/Ru7 (0001) and hcp Cr3/fcc Cu6 (111) superlattices. The Cr/Ru superlattice is found to be ferromagnetic with a small magnetic moment of ∼0.31μB/Cr while in contrast, Cr/Cu superlattice is found to be nonmagnetic.

scholarly journals Oxygen vacancy and doping atom effect on electronic structure and optical properties of Cd2SnO4

RSC Advances ◽  
2018 ◽  
Vol 8 (2) ◽  
pp. 640-646 ◽  
Author(s):  
Mei Tang ◽  
JiaXiang Shang ◽  
Yue Zhang
Keyword(s):  
Optical Properties ◽  
Electronic Structure ◽  
Oxygen Vacancy ◽  
Density Functional ◽  
Generalized Gradient ◽  
Functional Theory ◽  
The Density Functional Theory ◽  
La Doped ◽  
Doping Atom ◽  
Atom Effect

The electronic structure and optical properties of oxygen vacancy and La-doped Cd2SnO4 were calculated using the plane-wave-based pseudopotential method based on the density functional theory (DFT) within the generalized gradient approximation (GGA).

First Principles Calculations of Electronic Structure and Optical Properties of Cu-Doped SnS2

2013 ◽  
Vol 373-375 ◽  
pp. 1965-1969
Author(s):  
Kun Nan Qin ◽  
Ling Zhi Zhao ◽  
Yong Mei Liu ◽  
Fang Fang Li ◽  
Chao Yang Cui
Keyword(s):  
Optical Properties ◽  
Electronic Structure ◽  
First Principles ◽  
Density Functional ◽  
Optical Absorption Coefficient ◽  
Impurity Level ◽  
First Principles Calculations ◽  
Absorption Region ◽  
Functional Theory ◽  
The Density Functional Theory

The electronic structure and optical properties of Cu-doped SnS2with Sn-substituted content of 0, 12.5 and 37.5 at.% were successfully calculated by the first principles plane-wave pseudopotentials based on the density functional theory. It is found that the intermediate belts appear near the Fermi level and the energy band gap becomes narrower after the doping of the Cu atoms. The absorption peaks show a remarkable redshift and the absorption region broadens relatively after introducing acceptor impurity level. When Sn atoms of 37.5 at% were substituted by Cu, the optical absorption coefficient is significantly improved in the frequency range below 5.58 eV and over 8.13 eV.

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.

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