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Ab initio calculation of antimony sulphide nanowire
摘要： We have performed first-principles calculations on orthorhombic antimony sulphide (Sb2S3) nanowire using full-potential linearized augmented plane wave (FP-LAPW) method based on the density-functional theory (DFT) as implemented in WIEN2k package to investigate the electronic and optical properties. Engel–Vosko generalized gradient approximation (EV-GGA) is used as exchange-correlation functional. The nanowire is simulated in the [001] direction with vacuum in two directions using supercell method. The results are compared with Sb2S3 bulk in our pervious calculation. We have found that the electronic and optical properties significantly change in Sb2S3 nanowire. The density of state (DOS) for Sb2S3 nanowire calculated is higher than bulk Sb2S3 and from the electronic band structure, the indirect band gap is about 0.12 eV where this value is much lower than Sb2S3 bulk. However, this value is much lower than experimental value. The optical properties including absorption coefficient, reflectivity, refractive index and energy loss function are derived from the calculated complex dielectric for photon energy up to 20 eV to understand the optical behavior of Sb2S3 in one-dimensional (1-D) nanostructure. From analysis, the optical response of Sb2S3 nanowire demonstrate quite interesting optical behavior for one-dimension (1-D) nanostructure. The absorption coefficient for Sb2S3 nanowire is considerably higher in visible light range than Sb2S3 bulk.
关键词： optical properties,Antimony Sulphide,Density Functional Theory,LAPW,nanowire,electronic structure
更新于2025-09-23 15:23:52
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Electronic Structure for Europium Chalcogenides with Modified Becke–Johnson Potential Plus an On-Site Coulomb U (mBJ+U)
摘要： The full potential linearized-augmented-plane-wave (FP-LAPW) method is generalized to a case of an all-electron fully-relativistic spin-polarized self-consistent band calculation based on the relativistic spin-density functional theory and the modified Becke–Johnson potential (TB-mBJ) plus an on-site coulomb U employed for greater generation of the band gap. The results show that these materials are semiconducting materials. The indirect energy gap obtained in this calculation is 1.63 eV, 1.79 eV and 1.96 eV for EuS, EuSe and EuTe, respectively. It is clear from the plots that LSDA + U is a poor technique for the calculation of the band gaps of chalcogenides (EuX). The calculated results for EuX (S, Se and Te) by mBJ + U are in good agreement with the experimental values as compared to the other calculated results.
关键词： FP-LAPW,europium chalcogenides,mBJ + U,electronic structure.
更新于2025-09-23 15:22:29
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Modified Becke-Johnson (mBJ) exchange potential investigation of the optoelectronic properties of XThO <sub/>3</sub> (X=Ca, Sr and Ba)
摘要： The electronic structure and optical properties of CaThO3, SrThO3, and BaThO3 in cubic perovskite structure are calculated using a density functional theory with full potential linearized augmented plane wave (FP-LAPW) method. In this study, we have used the approximations LDA, GGA and mBJ. With mBJ the best approximation to get the band gap energy. This study is conducted through five stages: (1) We have started by optimizing the lattice parameters to find the basic state of each component (2) We have calculated electronic properties such as density of state, band structure, charge density (3) and basing on the band structure we have also calculated the optical properties as dielectric function, absorption coefficient, refractive index, reflectivity and optical conductivity to discuss the different transitions and the new peaks. The mechanical (4) and thermodynamic (5) behaviour was discussed for the first time for CaThO3 and BaThO3 in the cubic phase, in terms of elastic constants, and their related parameters, such as Young modulus, shear modulus, and Poisson ratio. Our results show that XThO3 has a stable ductile trait that makes it effective for high temperature electronic applications. As result, the various new peaks in the wide UV region due to the transition of electrons confirm the application of XThO3 (X= Ca, Sr and Ba) in the field of optoelectronic devices.
关键词： Perovskite,Optical Properties,mBJ,FP-LAPW,Electronic Structure
更新于2025-09-23 15:22:29
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Elastic and optoelectronic properties of CaTa2O6 compounds: Cubic and orthorhombic phases
摘要： Using first principles density functional theory (DFT) simulations, the structural, electronic, optical and elastic properties of CaTa2O6 oxide for cubic and orthorhombic phases are studied by highly accurate (FP-LAPW) method within the GGA + U approximation. The calculated lattice parameters are consistent with available experimental data. The electronic band structure calculations have shown that the band gaps in CaTa2O6 are equal to 3.08 eV and 4.40 eV for the cubic and orthorhombic structures, respectively. For both the phases the main optical properties, e.g., absorption coefficient, dielectric constant, energy loss function, and reflectivity, refractive index, and extinction coefficient are calculated and discussed in detail in the spectral range 0-14 eV. Cubic and orthorhombic phases exhibit significantly different optical characteristics. The electronic bonding characters of CaTa2O6 with different symmetries are explored via charge density distribution mapping. Strong covalent bonding character dominates in both the phases of CaTa2O6. Elastic properties of CaTa2O6 for cubic and orthorhombic phases are also investigated. The stress strain method is used for the determination of elastic constants in both the phases. The bulk modulus, shear modulus, Young’s modulus, along with the important elastic anisotropy factors and Poisson’s ratio are studied in detail.
关键词： First principles density functional theory,GGA+U approximation,FP-LAPW method,Optical constants,Electronic band structure,electro technical materials
更新于2025-09-23 15:22:29
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First-principles calculations of opto-electronic properties of IIIAs (III = Al, Ga, In) under influence of spin–orbit interaction effects
摘要： In this article, we present first-principles calculations for structural and opto-electric properties of IIIAs (III = Al, Ga, In) in the zinc-blende phase. Our calculations are based on the full potential-linearized augmented plane wave method implemented in the WIEN2k code. We employed Perdew–Burke–Ernzerhof generalized gradient and modified Becke–Johnson approximations as exchange–correlation potentials. Our calculated structure parameters are found to be in reasonable agreement with the available literature. It was found that the inclusion of spin–orbit interaction effect shifts the conduction band minima towards the Fermi level and provides band gaps very close to their experimental values. The optical properties such as complex dielectric functions, complex refractive indices, reflectivities, energy loss functions, optical conductivities and absorption coefficients at varied frequencies were investigated in detail. We found that static real part of dielectric functions and refractive index decreases with increase in band gap. Our calculated critical point energies (eV) are consistent with the experimental results.
关键词： optical properties,spin–orbit interaction,electronic properties,structural properties,FP-LAPW
更新于2025-09-19 17:15:36
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Ab initio Calculations of Optoelectronic Properties of Antimony Sulfide nano-thin film for Solar Cell Applications
摘要： Antimony sulfide (Sb2S3) micro thin-film have been received great interest as an absorbing layer for solar cell technology. In this study, to explore its further potential, electronic and optical properties of Sb2S3 simulated nano-thin film are investigated by the first-principles approach. To do so, the highly accurate full-potential linearized augmented plane wave (FP-LAPW) method framed within density functional theory (DFT) as implemented in the WIEN2k package is employed. The films are simulated in the [001] direction using the supercell method with a vacuum along z-direction so that slab and periodic images can be treated independently. From our calculations, indirect band gap energy values of Sb2S3 for various slabs are found to be 0.568, 0.596 and 0.609 eV for 1, 2 and 4 slabs respectively. Moreover, optical properties comprising of real and imaginary parts of the complex dielectric function, absorption coefficient, refractive index are also investigated to understand the optical behavior of the obtained simulated Sb2S3 thin films. From the analysis of their optical properties, it is clearly seen that Sb2S3 thin films have good values for optical absorption parameters in the visible and ultraviolet wavelength range, showing the aptness of antimony sulphide thins films for versatile optoelectronic applications as a base material.
关键词： DFT,Solar cell,optical properties,Sb2S3,thin-film,LAPW
更新于2025-09-11 14:15:04
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Modified Becke–Johnson (mBJ) exchange potential investigations of the structural and optoelectronic properties of BaThO3 in cubic and orthorhombic phase
摘要： The all electrons full potential linearized augmented plane waves (FP-LAPW) method with GGA, LDA and mBJ approximation is used to study BaThO3 perovskite in cubic and orthorhombic phases. The structural parameters are found consistent with the experimental results. The electronic band structures and density of states demonstrate that BaThO3 is a wide band gap insulator in both phases. Furthermore, the optical properties demonstrate that the optical gap of the material is 5.8 eV, which lies in the UV region of the electromagnetic spectrum and hence the compound can be used in optoelectronic devices.
关键词： Electronic structure,Optical properties,FP-LAPW,mBJ,Perovskite
更新于2025-09-10 09:29:36
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[IEEE 2018 15th International Multi-Conference on Systems, Signals & Devices (SSD) - Yassmine Hammamet, Tunisia (2018.3.19-2018.3.22)] 2018 15th International Multi-Conference on Systems, Signals & Devices (SSD) - The New Candidate Materials for Infrared Optical Devices
摘要： In this study, We propose the cubic AlxB1-xBi ternary alloy as a promising infrared material. We used the full potential-linearized augmented plane wave (FP-LAPW) method within the Density Functional Theory (DFT) to predict the structural and electronic properties of the AlxB1-xBi ternary alloys. The structural properties such as the equilibrium lattice parameter, bulk modulus, and its pressure derivative are investigated with the effect of the concentration variation of Al atom, x (x=0, 0.25, 0.50, 0.75 and 1). We found that the equilibrium lattice parameter of AlxB1-xBi ternary alloys increases when increasing the doping concentration of the Al atom, while its bulk modulus decreases. The energy band gap of the AlxB1-xBi ternary alloys decreases with the increase in the Al doping concentration. The AlxB1-xBi alloys for 0.50 and 0.75 present a semi-metallic character the other concentrations and are compositions. Our results show the direct nature of the energy band gap of the ternary AlxB1-xBi alloy for all composition of Al substitution. To our knowledge, this is the first theoretical study of this ternary alloy that needs eventual experimental data for confirmations.
关键词： Optical properties,TB-MBJ,FP-LAPW,Electronic structure,GGA,DFT,Infrared Radiation,III-III-V ternary Alloy
更新于2025-09-04 15:30:14