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.

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 First principles calculations on theoretical band gap improvement of IIIA-VA zinc-blende semiconductor InAs

2020 ◽  
Vol 31 (12) ◽  
pp. 2050178
Author(s):  
Waqas Mahmood ◽  
Arfan Bukhtiar ◽  
Muhammad Haroon ◽  
Bing Dong
Keyword(s):  
Band Gap ◽  
Density Functional ◽  
Local Density ◽  
Lattice Parameter ◽  
First Principles Calculations ◽  
Functional Theory ◽  
Zinc Blende ◽  
Valence States ◽  
Direct Band ◽  
Experimental Findings

The structural, electronic, dielectric and vibrational properties of zinc-blende (ZB) InAs were studied within the framework of density functional theory (DFT) by employing local density approximation and norm-conserving pseudopotentials. The optimal lattice parameter, direct band gap, static dielectric constant, phonon frequencies and Born effective charges calculated by treating In-4d electrons as valence states are in satisfactory agreement with other reported theoretical and experimental findings. The calculated band gap is reasonably accurate and improved in comparison to other findings. This work will be useful for more computational studies related to semiconductor devices.

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 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.

STRUCTURAL PHASE TRANSITION, ELASTIC AND ELECTRONIC PROPERTIES OF CuXSe2(X = In, Ga) CHALCOPYRITE

2012 ◽  
Vol 19 (02) ◽  
pp. 1250021 ◽  
Author(s):  
T. BOUGUETAIA ◽  
B. ABIDRI ◽  
B. BENBAHI ◽  
D. RACHED ◽  
S. HIADSI ◽  
...  
Keyword(s):  
Band Gap ◽  
Electronic Properties ◽  
Density Functional ◽  
Local Density ◽  
Structural Phase ◽  
Theoretical Data ◽  
Young Modulus ◽  
Orbital Method ◽  
Full Potential ◽  
Direct Band

The structural, elastic and electronic properties of chalcopyrite compound CuInSe2 and CuGaSe2 have been investigated using the full-potential linearized muffin-tin orbital method (FP-LMTO) within the frame of density functional theory (DFT). In this approach, the local density approximation is used for the exchange-correlation potential using Perdew–Wang parametrization. The equilibrium lattice parameters, bulk modulus, transition pressure, elastic constants and their related parameters such as Poisson's ratio, Young modulus, shear modulus and Debye temperature were calculated and compared with available experimental and theoretical data. They are in reasonable agreement. In this paper the electronic properties are treated with GGA + U approach, which brings out the important role played by the d-state of noble metal (Cu) and give the correct nature of the energy band gap. Our obtained results show that both compounds exhibit semi-conductor behaviour with direct band gap.

scholarly journals Structural, Electronic and Optical Properties of InAs Phases: By GGA-PBG and GGA-EV Approximations

2017 ◽  
Vol 41 (3) ◽  
pp. 172-182
Author(s):  
Leila Sohrabi ◽  
Arash Boochani ◽  
S. Ali Sebt ◽  
S. Mohammad Elahi
Keyword(s):  
Optical Properties ◽  
Band Gap ◽  
Density Functional ◽  
Photonic Devices ◽  
Optical Parameters ◽  
Full Potential ◽  
Electronic Band ◽  
Electronic And Optical Properties ◽  
Direct Band ◽  
Electronic Band Gap

Structural, electronic and optical properties of InAs are investigated in the zinc-blende (ZB), rock-salt (RS) and wurtzite (WZ) phases using the full potential linearised augmented plane wave method in the framework of density functional theory (DFT). The electronic band gap of the ZB and WZ phases are improved and in good agreement with experiments by GGA-EV approximation. This compound has a direct band gap in the ZB and WZ phases in point at the centre Brillouin zone and in the RS phase the conduction band crosses towards the valence band and has metallic behaviour. Also, the optical parameters such as the real and imaginary parts of epsilon, energy loss, and the refraction and reflection indices of all the phases are calculated and compared. The calculated optical properties of InAs have promising applications such as the design of optoelectronic and photonic devices.

FP-LMTO study of structural, electronic, thermodynamic and optical properties of MgxCd1−x Se alloys

2014 ◽  
Vol 32 (4) ◽  
pp. 719-728 ◽  
Author(s):  
D. Bensaid ◽  
M. Ameri ◽  
M. El Hanani ◽  
Y. Azaz ◽  
D. Bendouma ◽  
...  
Keyword(s):  
Refractive Index ◽  
Optical Properties ◽  
Band Gap ◽  
Density Functional ◽  
Molar Fraction ◽  
Dielectric Constants ◽  
Ternary Alloys ◽  
Wide Range ◽  
Direct Band ◽  
Extraordinary Refractive Index

AbstractStructural, electronic and optical properties of MgxCd1−x Se (0 ≤ x ≤ 1) are calculated for the first time using density functional theory. Our results show that these properties are strongly dependent on molar fraction of particular components — x. The bond between Cd and Se is partially covalent and the covalent nature of the bond decreases as the concentration of Mg increases from 0 % to 100 %. It is found that MgxCd1−x Se has a direct band gap in the entire range of x and the band gap of the alloy increases from 0.43 to 2.46 eV with the increase in Mg concentration. Frequency dependent dielectric constants ɛ1(ω), ɛ2(ω) refractive index n(ω) are also calculated and discussed in detail. The peak value of refractive indices shifts to higher energy regions with the increase in Mg. The larger value of the extraordinary refractive index confirms that the material is a positive birefringence crystal. The present comprehensive theoretical study of the optoelectronic properties of the material predicts that it can be effectively used in optoelectronic applications in the wide range of spectra: IR, visible and UV. In addition, we have also predicted the heat capacities (CV), the entropy (S), the internal energy (U) and the Helmholtz free energy (F) of MgxCd1−x Se ternary alloys.

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.

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.

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