scholarly journals Ground State Properties of the Wide Band Gap Semiconductor Beryllium Sulfide (BeS)

Materials ◽  
2021 ◽  
Vol 14 (20) ◽  
pp. 6128
Author(s):  
Blaise A. Ayirizia ◽  
Janee’ S. Brumfield ◽  
Yuriy Malozovsky ◽  
Diola Bagayoko
Keyword(s):  
Band Gap ◽  
Lattice Constant ◽  
Ground State ◽  
Density Functional ◽  
Local Density ◽  
Wide Band ◽  
Electronic Energy ◽  
Computational Method ◽  
Energy Bands ◽  
Ground State Properties

We report the results from self-consistent calculations of electronic, transport, and bulk properties of beryllium sulfide (BeS) in the zinc-blende phase, and employed an ab-initio local density approximation (LDA) potential and the linear combination of atomic orbitals (LCAO). We obtained the ground state properties of zb-BeS with the Bagayoko, Zhao, and Williams (BZW) computational method, as enhanced by Ekuma and Franklin (BZW-EF). Our findings include the electronic energy bands, the total (DOS) and partial (pDOS) densities of states, electron and hole effective masses, the equilibrium lattice constant, and the bulk modulus. The calculated band structure clearly shows that zb-BeS has an indirect energy band gap of 5.436 eV, from Γ to a point between Γ and X, for an experimental lattice constant of 4.863 Å. This is in excellent agreement with the experiment, unlike the findings of more than 15 previous density functional theory (DFT) calculations that did not perform the generalized minimization of the energy functional, required by the second DFT theorem, which is inherent to the implementation of our BZW-EF method.

scholarly journals First Principle Investigation of Electronic, Transport, and Bulk Properties of Zinc-Blende Magnesium Sulfide

Electronics ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 1791
Author(s):  
Uttam Bhandari ◽  
Blaise Awola Ayirizia ◽  
Yuriy Malozovsky ◽  
Lashounda Franklin ◽  
Diola Bagayoko
Keyword(s):  
Band Gap ◽  
Lattice Constant ◽  
Density Functional ◽  
Local Density ◽  
Computational Method ◽  
Physical Content ◽  
Conduction Bands ◽  
Zinc Blende ◽  
Densities Of States ◽  
Magnesium Sulfide

We have studied electronic, structural, and transport properties of zinc-blende magnesium sulfide (zb-MgS). We employed a local density approximation (LDA) potential and the linear combination of atomic orbitals (LCAO) method. Our computational method is able to reach the ground state of a material, as dictated by the second theorem of density functional theory (DFT). Consequently, our findings have the physical content of DFT and agree with available, corresponding experimental ones. The calculated band gap of zb-MgS, a direct gap equal to 4.43 eV, obtained at the experimental lattice constant of 5.620 Å, completely agrees with the experimental band gap of 4.45 ± 0.2 eV. We also report total (DOS) and partial (pDOS) densities of states, electron and hole effective masses, the equilibrium lattice constant, and the bulk modulus. The calculated pDOS also agree with the experiment for the description of the states at the top and the bottom of the valence and conduction bands, respectively.

Electronic Structure and Ground State Properties of A4[Ag4O4] (A=Na, K and Rb): A First-Principles Study

2013 ◽  
Vol 665 ◽  
pp. 43-48
Author(s):  
Rajagopalan Umamaheswari ◽  
M. Yogeswari ◽  
G. Kalpana
Keyword(s):  
Electronic Structure ◽  
Band Gap ◽  
Ground State ◽  
First Principles ◽  
Density Functional ◽  
Electronic Band Structure ◽  
First Principles Calculation ◽  
Partial Density ◽  
Electronic Band ◽  
Ground State Properties

The first-principles calculation within density functional theory is used to study in detail the electronic structure and ground state properties of alkali-metal oxoargenates A4[Ag4O4] (A= Na, K and Rb). The total energies calculated within the atomic sphere approximation (ASA) were used to determine the ground state properties such as equilibrium lattice parameter, c/a ratio, bulk modulus and cohesive energy. The theoretically calculated equilibrium lattice constants values are in well agreement with the available experimental values. The electronic band structures, total and partial density of states are calculated. The result of electronic band structure shows that the KAgO and RbAgO are direct band gap semiconductors with their gap lying between the Γ-Γ points, whereas NaAgO is found to be an indirect band gap semiconductor with its gap lying between Z-Γ points.

scholarly journals Ab Initio Study of MgTe Self-Interstitial (Mgi and Tei): A Wide Band Gap Semiconductor

2017 ◽  
Vol 16 ◽  
pp. 47-51
Author(s):  
Emmanuel Igumbor ◽  
Ezekiel Omotoso ◽  
Walter Ernst Meyer
Keyword(s):  
Band Gap ◽  
Density Functional ◽  
Defect Formation ◽  
Local Density ◽  
Wide Band ◽  
Shallow Donor ◽  
Generalized Gradient ◽  
Wide Band Gap ◽  
Functional Theory ◽  
Formation Energies

We present results of defect formation energies and charge state thermodynamic transition levels of Mg and Te interstitials in MgTe wurzite structure. We use the generalized gradient approximation and local density approximation functionals in the framework of density functional theory for all calculations. The formation energies of the Mg and Te interstitials in MgTe for both the tetrahedral and hexagonal configurations were obtained. The Mg and Te interstitials in MgTe depending on the functional, introduced transition state levels that are either donor or acceptor within the band gap of the MgTe. The Te interstitial exhibit charge states controlled metastability, negative-U and DX centre properties. The Mg interstitial acts as deep or shallow donor and there is no evidence of acceptor levels found for the Mg interstitial.

First-Principles Study of Electronic Structure of Cubic Perovskite-Like Fluorides

2015 ◽  
Vol 230 ◽  
pp. 79-84
Author(s):  
Stepan Syrotyuk ◽  
Vira Shved
Keyword(s):  
Ground State ◽  
First Principles ◽  
Local Density ◽  
Electronic Energy ◽  
Energy Spectra ◽  
Energy Bands ◽  
Gw Approximation ◽  
Electronic Density ◽  
Electronic Energy Bands ◽  
First Time

The electronic density of states of cubic perovskite-like fluorides has been evaluated by means of the projector augmented waves (PAW) within the local density approximation (LDA). For the first time the improved electronic energy bands have been calculated using the GW approximation. Ground-state and quasiparticle calculations have been done with the ABINIT code. Combined analysis of the densities of electronic states and obtained electron energy spectra makes it possible to draw conclusions regarding the possibility of the phenomenon of core-valence luminescence in the considered crystals.

scholarly journals Effect of Hartree–Fock pseudopotentials on local density functional theory calculations

2018 ◽  
Vol 20 (27) ◽  
pp. 18844-18849 ◽  
Author(s):  
Hengxin Tan ◽  
Yuanchang Li ◽  
S. B. Zhang ◽  
Wenhui Duan
Keyword(s):  
Density Functional Theory ◽  
Band Gap ◽  
Density Functional ◽  
Local Density ◽  
Density Functional Theory Calculations ◽  
Optimal Choice ◽  
Functional Theory ◽  
Hartree Fock ◽  
Local Density Functional Theory ◽  
Local Density Functional

Optimal choice of the element-specific pseudopotential improves the band gap.

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.

Laplacian free and asymptotic corrected semilocal exchange potential applied to the band gap of solids

2019 ◽  
Vol 21 (35) ◽  
pp. 19639-19650 ◽  
Author(s):  
Abhilash Patra ◽  
Subrata Jana ◽  
Hemanadhan Myneni ◽  
Prasanjit Samal
Keyword(s):  
Density Functional Theory ◽  
Band Gap ◽  
Density Functional ◽  
Local Density ◽  
Exchange Potential ◽  
Functional Theory ◽  
Type Semiconductor ◽  
Local Density Functional Theory ◽  
Local Density Functional

Improved band gap of n-type semiconductor ZrS2 within semi-local density functional theory is shown. The band gap of mBR-TBMBJ agrees well with the hybrid HSE06 functional.

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 Ground state properties and shape evolution in Pt isotopes within the covariant density functional theory

2019 ◽  
Vol 28 (10) ◽  
pp. 1950078
Author(s):  
Y. El Bassem ◽  
M. Oulne
Keyword(s):  
Density Functional Theory ◽  
Ground State ◽  
Density Functional ◽  
Meson Exchange ◽  
Isotopic Chain ◽  
Functional Theory ◽  
Density Dependent ◽  
Covariant Density Functional Theory ◽  
Ground State Properties ◽  
Covariant Density

In this work, the ground state properties of the platinum isotopic chain, [Formula: see text]Pt are studied within the covariant density functional theory. The calculations are carried out for a large number of even–even Pt isotopes by using the density-dependent point-coupling and the density-dependent meson-exchange effective interactions. All ground state properties such as the binding energy, separation energy, two-neutron shell gap, root mean square (rms)-radii for neutrons and protons and quadrupole deformation are discussed and compared with available experimental data, and with the predictions of some nuclear models such as the Relativistic Mean Field (RMF) model with NL3 functional and the Hartree–Fock–Bogoliubov (HFB) method with SLy4 Skyrme force. The shape phase transition for Pt isotopic chain is also studied. Its corresponding total energy curves as well as the potential energy surfaces confirm the transition from prolate to oblate shapes at [Formula: see text]Pt contrary to some studies predictions and in agreement with others. Overall, a good agreement is found between the calculated and experimental results wherever available.

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