Structural and electronic properties of [formula omitted] ternary alloys

Abstract

The structural and electronic properties of GaxTl1−xP ternary alloys in zincblende phase were studied using pseudopotential plane wave method within the density functional theory. The dependence of the lattice parameter, bulk modulus, its pressure derivative, electronic structure, energy band gap and optical bowing on the composition x were analyzed for 0<x<1 with small increments, disregarding the so long computational time. The lattice parameters were optimized exhibiting linear concentration dependence in accordance with Vegard׳s law. The bulk modulus as a function of gallium composition shows linear-like concentration dependence with a large upward bowing parameter equal to 10.79GPa. We found that the band gap increases with increasing compositions of Ga, so that the compounds change from metal to semiconducting phase and could be useful for device applications in spintronics, especially at certain contributions. As a consequence the band gap bowing is found to be strongly composition dependent. The microscopic origins of the gap bowing were detailed and explained according to Zunger approach.