Electronic structure and lattice properties of zinc-blende InN under high pressure

Dependencies of electronic structure and lattice properties of InN with zinc-blende structure on hydrostatic pressure are presented based on band structures computed using the empirical pseudopotential method. The pressure behavior of the pseudopotential form factors have been analyzed. The effect of pressure on the density of states has been examined. Trends in bonding and ionicity under pressure are also discussed. Our results show as well that the absolute value of the Fourier transform of the valence charge density might be useful in the prediction of the phase transition in zinc-blende materials

Theoretical study of electronic and positronic properties in Ga

The electronic and positronic properties of the pentanary semiconductor alloys Gaxln1-xPySbzAs1-y-z lattice matched to GaSb have been studied. The electron wave function is calculated semiempirically using the pseudopotential band model under the virtual crystal approximation. The positron wave function is evaluated under the point core approximation for the ionic potential. Electronic and positronic quantities namely, electronic structure and band gaps, positron band structure, effective mass and affinity, and electron-positron momentum densities have been predicted and their dependence on the phosphorus composition has been discussed

Band gaps and charge distribution in quasi-binary (GaSb)

Pseudopotential investigation of energy band gaps and charge distribution in quasi-binary (GaSb)1-x(InAs)x crystals has been reported. To the best of our knowledge, there had been no reported theoretical work on these materials. In agreement with experiment, the quasi-binary crystals of interest showed a significant narrowing of the optical band gap compared to the conventional GaxIn1-xAsySb1-y quaternary alloys (with $x=1-y$). Moreover, the absorption at the optical gaps indicated that (GaSb)1-x(InAs)x is a direct Γ to Γ band-gap semiconductor within a whole range of the x composition. The information derived from the present study predicts that the band gaps cross very important technological spectral regions and could be useful for thermophotovoltaic applications

First-principles calculations to investigate electronic structure and optical spectra of CdxZn1-xS ternary semiconductor alloys

The structural parameters, electronic band structure and optical spectra of CdxZn1-xS (0 ≤ x ≤ 1) ternary semiconductor alloys are studied. The calculations are realized using the full potential linearized augmented plane wave method. The modified local density approximation (LDA) and generalized gradient approximation (GGA) have been used for describing the exchange-correlation potential. The obtained results for zinc-blende CdxZn1-xS ternary alloys show a general wellness with the data shown in the literature. An inspection of electronic band structure indicates that zinc-blende CdxZn1-xS are (Г→Г) direct band gap semiconductors (from x = 0 up to x = 1). A predominant ionic type of the chemical bonding in these materials has been indicated. The density of states shows various peaks in both valence and conduction localities proposing that an abundance of conditions is obtainable for occupation. The alloys affect the optical features of interest. The results obtained from the present work show that the zinc-blende CdxZn1-xS is a promettant material for photovoltaic device applications. Moreover, the alloy of interest can be used in different devices from visible to ultraviolet light

Electron slowing down in solid targets: Monte-Carlo calculations

We have performed Monte-Carlo simulations of slow electrons impinging on semi-infinite aluminum and copper in the energy range 0.5–4 keV. We present results for the backscattering coefficients, mean penetration depths and stopping profiles. Our results for the backscattering coefficients agree well with the experimental data within the limits of the statistical accuracy. The slight discrepancy between simulated and experimental results regarding the mean penetration depth is discussed

Phase Transition and Mechanical Stability of InN Compound

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Pressure dependence of elastic constants and related parameters for rocksalt MgO

Based on the full-potential linearized augmented plane wave (FP-LAPW) method within the density functional theory (DFT) in both the local density approximation (LDA) and the generalized gradient approximation (GGA) approaches, the elastic constants and some of their related parameters such as the bulk modulus, shear modulus, [1 0 0] Young's modulus, anisotropy factor, [1 0 0] Poisson's ratio, and internal strain parameter have been reported for MgO in the rocksalt structure. The overall agreement between our results and the available experimental and theoretical data is found to be reasonably good. The pressure dependence of all studied quantities has been investigated. The mechanical stability criteria for the material of interest for pressures up to 100 GPa are fulfilled

Pressure dependence of elastic constants and related parameters for rocksalt MgO

Based on the full-potential linearized augmented plane wave (FP-LAPW) method within the density functional theory (DFT) in both the local density approximation (LDA) and the generalized gradient approximation (GGA) approaches, the elastic constants and some of their related parameters such as the bulk modulus, shear modulus, [1 0 0] Young's modulus, anisotropy factor, [1 0 0] Poisson's ratio, and internal strain parameter have been reported for MgO in the rocksalt structure. The overall agreement between our results and the available experimental and theoretical data is found to be reasonably good. The pressure dependence of all studied quantities has been investigated. The mechanical stability criteria for the material of interest for pressures up to 100 GPa are fulfilled