Structural and electronic properties of the wide-gap Zn_1−xMg_xS, Zn_1−xMg_xSe and Zn_1−xMg_xTe ternary alloys

Abstract

Zn 1−x Mg x S, Zn 1−x Mg x Se and Zn 1−x Mg x Te ternary wide-gap semiconductor alloys were investigated using the full potential-linearized augmented plane wave (FP-LAPW) method. We have studied the effect of composition on structural properties such as lattice constants, bulk modulus and bond ionicity. The bandgap and the microscopic origins of compositional disorder have also been explained in detail. In addition, from the obtained band structures, the electron (hole) conduction and valence effective masses are deduced. These parameters were found to depend non-linearly on alloy composition x, except the lattice parameter for Zn 1−x Mg x S, which follows Vegard's law. The calculated band structures for all three alloys show a direct bandgap in the whole range of x composition. We have paid special attention to the disorder parameter (gap bowing). Using the approach of Zunger and co-workers, we have concluded that the total bandgap energy bowing was mainly caused by the charge exchange effect for the alloys of interest.

Theoretical Study on the Origins of the Gap Bowing in Mg<sub>x</sub>Zn<sub>1–x</sub>O Alloys

“…This scheme has been applied to many semiconductors alloys [16][17][18][19][20][21][22] successfully. We calculated the equilibrium structural parameters (lattice constant and bulk modulus) for the parent binary compounds MgO, ZnO and their ternary alloy.…”

First-Principles Study of Cubic BxIn1-xN Ternary Alloys

“…These include methods based on the dielectric two-band model [6], semi-empirical tight-binding method [7,8] semi-empirical pseudo-potential method [9,10], ab initio pseudo-potential method [11][12][13][14][15][16][17][18][19][20][21][22] and full potential linearized augmented plane wave (FP-LAPW) method [23,24]. To our knowledge, there is no theoretical investigation of B x In 1−x N alloy.…”

First-principles calculations of structural, electronic and thermal properties of Zn1−x MgxS ternary alloys

“…This indicates that the volume of Zn 0 25 Mg 0 75 S alloy varies significantly as the temperature increases when T > 100 K. However, the [12] using PBE-GGA approximation Ref. [12] using Engel-Vosko EV-GGA approximation.…”

“…As a mater of fact Zn 1− Mg S alloys are promising candidates [6] for their energy gaps and lattice constants which can be varied in a wide range of stoichiometry parameter . Although a number of experimental and theoretical studies of Zn 1− Mg S semiconductor alloys have been published [7][8][9][10][11][12], to the best of our knowledge there are no available data for their thermal properties. Thermodynamic properties for crystalline materials are very important in many applications involving high pressure and high temperature.…”