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.

THEORETICAL INVESTIGATION OF THE ELASTIC PROPERTIES AND LATTICE DYNAMICS OF THE MgSxSe1-x ALLOY

2007 ◽  
Vol 21 (05) ◽  
pp. 249-259 ◽  
Author(s):  
K. BOUAMAMA ◽  
P. DJEMIA
Keyword(s):  
Elastic Properties ◽  
First Principles ◽  
Lattice Dynamics ◽  
Density Functional ◽  
Local Density ◽  
Lattice Parameter ◽  
First Principles Calculations ◽  
Virtual Crystal Approximation ◽  
Functional Theory ◽  
Density Functional Perturbation Theory

Structural and elastic properties as well as lattice dynamics of ternary MgS x Se 1-x alloy have been studied using first-principles calculations. These are done using density functional theory (DFT) and density functional perturbation theory (DFPT) within the local density approximation (LDA) and employing the virtual-crystal approximation (VCA). We found that the lattice parameter, the elastic constants and the phonon frequencies follow a quadratic law in x.

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.

Direct band gap nature and optical response of BexMgyZn1−(x+y)Se

2016 ◽  
Vol 30 (03) ◽  
pp. 1650007
Author(s):  
Naeemullah ◽  
G. Murtaza ◽  
R. Khenata ◽  
S. Bin Omran
Keyword(s):  
Band Gap ◽  
First Principles ◽  
Density Functional ◽  
Experimental Measurements ◽  
First Principles Calculations ◽  
Functional Theory ◽  
Direct Band Gap ◽  
Direct Band ◽  
First Time ◽  
Ultraviolet Energy

For the first time, the electronic and optical properties of the quaternary Be[Formula: see text]Mg[Formula: see text]Zn[Formula: see text]Se alloy have been investigated using first-principles calculations within the framework of density functional theory (DFT). Variations in the direct band gap with the change in [Formula: see text] and [Formula: see text] compositions show agreement with the experimental measurements. Evaluation of the dielectric function and refractive index reveals the optical activity in the visible and ultraviolet energy regions.

Thermodynamic properties of ZnTe in zinc-blende and wurtzite phases

2016 ◽  
Vol 30 (21) ◽  
pp. 1650147 ◽  
Author(s):  
S. Ferahtia ◽  
S. Saib ◽  
N. Bouarissa
Keyword(s):  
Density Functional Theory ◽  
First Principles ◽  
Density Functional ◽  
Local Density ◽  
Density Approximation ◽  
First Principles Calculations ◽  
Functional Theory ◽  
Zinc Blende ◽  
The Density Functional Theory ◽  
Two Phases

The present study deals with first-principles calculations of the thermal properties of ZnTe in the two phases namely, zinc-blende and wurtzite. The calculations are mainly performed using the density functional theory with the local density approximation and response-function calculations. The full phonon dispersions throughout the Brillouin zone are presented. The temperature dependence of the lattice parameters, bulk modulus, entropy and heat capacity are examined and discussed. Our findings agree reasonably well with those available in the literature.

Indirect-Direct Band Gap Transition by Van Der Waals Interaction Engineering in MoS2/WS2 Bilayer Heterojunction

2014 ◽  
Vol 614 ◽  
pp. 70-74 ◽  
Author(s):  
Hai Ning Cao ◽  
Zhi Ya Zhang ◽  
Ming Su Si ◽  
Feng Zhang ◽  
Yu Hua Wang
Keyword(s):  
Band Gap ◽  
First Principles ◽  
Electronic Structures ◽  
Density Functional ◽  
First Principles Calculations ◽  
Functional Theory ◽  
Direct Band Gap ◽  
The Density Functional Theory ◽  
Direct Band ◽  
Electric Filed

First principles calculations based on the density functional theory (DFT) are employed to estimate the electronic structures of bilayer heterostructure of MoS2/WS2. The dependences of the band structures on external electric field and interlayer separation are evaluated. The external electric filed induces a semiconductor-metal transition. At the same time, a larger interlayer separation, corresponding to a weaker interlayer interaction, makes an indirect-direct band gap transition happen for the heterojunction. Our results demonstrate that electronic structure tailoring of two-dimensional layered materials should include both spatial symmetry control and interlayer vdW interactions engineering.

scholarly journals Half-metallic ferromagnetism and band gap reduction in Cu-doped zinc-blende BeO: first-principle study -=SUP=-*-=/SUP=-

2017 ◽  
Vol 59 (5) ◽  
pp. 835
Author(s):  
L. Kahal
Keyword(s):  
Band Gap ◽  
Density Functional ◽  
Ferromagnetic State ◽  
Partial Density ◽  
First Principles Calculations ◽  
Functional Theory ◽  
Half Metallic ◽  
Zinc Blende ◽  
Metallic Ferromagnetism ◽  
Half Metallic Ferromagnetism

In this paper, we report ferromagnetism in copper doped zinc-blende BeO. Our first-principles calculations based on spin density functional theory predicts a total magnetic moment of 1 muB per copper when copper substitutes beryllium in BeO, where 0.58 muB is localized at Cu atom. The results obtained show that the ferromagnetic state is 34 meV lower than the antiferromagnetic state. Calculations indicate an appreciable band gap reduction in BeO. The analysis of the partial density of states reveals that ferromagnetism and reduction of BeO band gap are principally due to the strong p-d coupling of O and Cu. DOI: 10.21883/FTT.2017.05.44367.337

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.

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.

First-principles Calculations of Energetic Properties of Vacancies, Mn-atomic Defects in CdTe

2006 ◽  
Vol 959 ◽  
Author(s):  
Ghouti Merad ◽  
Benali Rerbal ◽  
Hafid Aourag ◽  
Joël Cibert
Keyword(s):  
Density Functional Theory ◽  
First Principles ◽  
Density Functional ◽  
Local Density ◽  
Density Approximation ◽  
First Principles Calculations ◽  
Functional Theory ◽  
Energetic Properties ◽  
Atomistic Modelling ◽  
Atomic Type

ABSTRACTAn atomistic modelling based on density functional theory within the framework of the local density approximation is used to show the trends in the energetic properties of single and double defects in CdTe semiconductor, without phase transformation. A systematic study of vacancies, Mn substituting Cd atoms in a supercell structure consisting of 16-atoms is presented. The changes of structural properties and lattice parameters due to the addition of Mn-atomic type defects in CdTe matrix are compared, and the number of vacancies is also determined from the total energy calculations.

Systematic first principles calculations of the effects of stacking faults defects on the 4H-SiC band structure

2010 ◽  
Vol 1246 ◽  
Author(s):  
Massimo Camarda ◽  
pietro delugas ◽  
Andrea Canino ◽  
Andrea Severino ◽  
nicolo piluso ◽  
...  
Keyword(s):  
First Principles ◽  
Density Functional ◽  
Stacking Faults ◽  
Perfect Crystal ◽  
First Principles Calculations ◽  
Electronic Band ◽  
Functional Theory ◽  
Experimental Findings ◽  
Electronic Band Structures ◽  
Formation Energies

AbstractShockley-type Stacking faults (SSF) in hexagonal Silicon Carbide polytypes have received considerable attention in recent years since it has been found that these defects are responsible for the degradation of forward I-V characteristics in p-i-n diodes. In order to extend the knowledge on these kind of defects and theoretically support experimental findings (specifically, photoluminescence spectral analysis), we have determined the Kohn-Sham electronic band structures, along the closed path Γ-M-K-Γ, using density functional theory. We have also determined the energies of the SSFs with respect to the perfect crystal finding that the (35) and (44) SSFs have unexpectedly low formation energies, for this reason we could expect these two defects to be easily generated/expanded either during the growth or post-growth process steps.

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