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First-principles all electrons density-functional calculations for the band structure and magnetization of Zn1−xCoxO ternary magnetic alloys, in three phases namely zinc-blende, rocksalt and wurtzite have been reported. The computations are spin-polarized. An inspection of our electronic properties showed that the alloy system of interest exhibits a semiconducting character where the nature of the gap depends on the considered phase. An analysis of electronic charge density suggests that the bonding has a partially covalent character for ZnO which becomes weaker as far as the Co concentration increases. CoO is found to reach a total magnetization of 3 μB per cell for zinc-blende and rocksalt phases and 6 μB per cell for wurtzite phase. [ABSTRACT FROM AUTHOR]

The present study reports on the electronic band structure and optical properties of Cs2AgBiBr6 doubleperovskite material using a pseudopotential plane-wave method within the generalized gradient approximation. Our results show that Cs2AgBiBr6 has a good absorption in the visible spectrum region, nevertheless, it has an indirect band gap of magnitude of 1.32 eV. This limits its application in photovoltaics. An alternative is proposed to overcome this shortcoming. [ABSTRACT FROM AUTHOR]

A pseudopotential scheme, which incorporates compositional disorder as an effective potential, is used so as to calculate the optical properties of Ga x In 1− x P ternary alloys in the zinc-blende structure. Generally, the agreement between our results and the existing data in the literature is reasonable. The composition dependence of the studied features showed a non-monotonic behaviour for most studied features. Reasons for these findings are discussed. Moreover, the effect of the compositional disorder on the features of interest has been examined and found to be important for the calculation of optical properties of Ga x In 1− x P. [ABSTRACT FROM AUTHOR]

The results of pseudopotential calculations of the band structure and related electronic and optical properties of quasi-binary (GaP)(ZnSe) crystals in the zinc blende structure are presented. Trends in bonding and ionicity are discussed in terms of electronic charge densities. Moreover, the composition dependence of the refractive index and dielectric constants are reported. The computed values are in reasonable agreement with experimental data. The results suggest that for a proper choice of the composition x, (GaP)(ZnSe) could provide more diverse opportunities to achieve the desired electronic and optical properties of the crystals which would improve the performances of devices fabricated on them. [ABSTRACT FROM AUTHOR]

Abstract: The results of pseudopotential within the virtual crystal approximation (VCA) combined with the Harrison bond-orbital model calculations of the electronic and lattice dynamic properties of InAs x Sb1−x are presented. The results include energy band-gaps, elastic constants, sound wave velocities, longitudinal optical (LO) and transversal optical (TO) phonon frequencies. The effect of compositional disorder on the fundamental energy band-gap has been examined and found to be important. Thus, this effect is included in all the calculations of the quantities being studied here. The agreement between our numerically calculated results and the available experimental data is found to be satisfactory. The information derived from the present study shows that InAs x Sb1−x properties might be useful in optoelectronic applications as regards infrared and mid-infrared spectral regions. [Copyright &y& Elsevier]

The optical response functions and their derived reflectivity spectrum, the absorption coefficient and the optical conductivity are calculated for zinc-blende-structured Cd1-xMnxTe with Mn concentration in the range 0-1. The evolution of the optical spectra with increased Mn concentrations is examined and discussed. The calculations are performed within the generalized gradient approximation of Engel-Vosko to the density functional theory, and the one-electron equations are solved by means of the full potential linearized augmented plane wave method. Generally, our results are found to be in reasonable agreement with the available experimental and theoretical data reported in the literature. [ABSTRACT FROM AUTHOR]

Highlights: [•] Elastic properties of ZnTe1−xO x ternary system. [•] Compositional dependence of optical phonon modes in ZnTe1−xO x ternary system. [•] Dielectric constants in ZnTe1−xO x ternary system. [ABSTRACT FROM AUTHOR]