Brens Elkenany

Effect of pressure and temperature on electronic structure of GaN in the zinc-blende structure

The effect of the hydrostatic pressure and the temperature on the electronic structure in GaN semiconductor has been calculated using the local empirical pseudopotential method. The variation of the direct and indirect energy gaps with the pressure up to 120 kbar and with the temperature up to 500 K has been done. The calculated fundamental energy gap at different pressures and different temperatures are calculated and compared with the available experimental data which show excellent agreement. The effect of pressure and temperature on the refractive index of the considered materials has also been studied.

Theoretical investigations of electronic, optical and mechanical properties for GaSb and AlSb semiconductors under the influence of temperature

In this paper we explore the effects of temperature on the electronic and mechanical properties of GaSb and AlSb semiconductors by using the local empirical pseudo-potential method. Our results show that the band gaps, refractive index, optical dielectric constant, elastic constants (C11, C12, C44), bulk modulus, shear modulus and Young modulus of these compounds vary with the change in temperature. The comparison of some of our results with the available experimental data confirms the accurateness of our theoretical approach, which also infers the reliability of our other theoretical results. As, for some of the present calculations a little experimental data is available for comparison, therefore these results can be used as a reference work in the future studies.

Structural and electronic properties of Si1 − xGex binary semiconducting alloys under the effect of temperature and pressure

Based on the empirical pseudo-potential method which incorporates compositional disorder as an effective potential, the band structure of Si1 − xGex alloy are calculated for different alloy composition x. The effect of temperature and pressure on the electronic band structure of the considered alloy has been studied. Monotonic decreasing and increasing functions are obtained for the temperature and pressure dependent form factors respectively. Some physical quantities as band gaps, bowing parameters, and the refractive index of the considered alloy with different Ge concentration and under the effect of temperature and pressure are calculated. The results obtained are found in good agreement with the experimental and published data.

Temperature and Pressure Dependence of Elastic Constants and Related Parameters for InP Semiconductor

Based on the empirical pseudo-potential method (EPM), the symmetric and anti-symmetric pseudo-potential form factors have been adjusted to match the calculated energy gaps of InP with the corresponding experimental values. The adjusted symmetrical and anti-symmetrical form factors at G(1,1,1) have been used to calculate the polarity of the considered material. The elastic constants C 11, C 12 and C 44 of InP have been obtained. The knowledge of these constants helps us to determine their related elastic parameters such as bulk (Bu), shear (Cs) and Young’s (Y0) moduli. Other important parameters such as Poisson’s ratio (σ ), linear compressibility (C0 ), Cauchy ratio (Ca) , Born ratio (B0), isotropy factor (A ), bond stretching (α ), bond binding force (β ) and internal strain parameter (ζ ) for InP have also been calculated. The variation of all studied quantities with temperature and pressure has been investigated. Our results show a good agreement with the available experimental data. Most of our data may be taken as references especially for high values of temperature and pressure.

Pressure Dependence of Mechanical Properties in AlP and AlSb Semiconductors

The effect of pressure on the mechanical properties of zinc-blende AlP and AlSb semiconductors has been investigated using the local empirical pseudo-potential method (EPM). The studied quantities are the elastic constants(cij), bulk modulus (Bu), shear modulus (Sh),Young modulus (Y0), Poisson’s ratio (σ, bond stretching (α, bond binding force (β, internal strain parameter (ζ, linear compressibility (C0) and Cauchy ratio (Ca). All studied quantities are found to be affected with pressure except the internal strain parameter and Poisson’s ratio. The mechanical stability criteria for the materials of interest for pressure up to 120 Kbar are fulfilled. The considered materials can be used in optoelectronic devices. The overall agreement between our results and the available experimental and theoretical data is found to be reasonable good. Our calculated values may serve as a reference, especially for high pressure.

Mechanical properties of GaxIn1-xAsyP1-y/GaAs system at different temperatures and pressures

The mechanical properties, such as the elastic constants C11, C12, C44, and bulk, Young’s, and shear moduli, of a Ga x In1-x As y P1-y alloy lattice matching to a Ga As substrate are calculated for various As concentrations. The calculations are based on the pseudo-potential method within the virtual crystal approximation containing the effective disorder potential. The variations of the studied properties with pressure and temperature are investigated. A comparison between the calculated results and the available published data for binary parent compounds shows that they have good agreement,while the calculated results for the quaternary alloys at various temperature and pressure may be taken as a reference.