Ab initio study of the structural, electronic and thermodynamic properties of of PbSe_(1-x)S_x, PbSe_(1-x)Te_x and PbS _(1-x)Te_x ternary alloys

摘要

The structural, electronic and thermodynamic properties of PbSe _(1-x)S_x, PbSe_(1-x)Te_x and PbS _(1-x)Te_x ternary alloys have been calculated using the full-potential linearized-augmented plane wave method. The exchange and correlation potential is treated by the generalized gradient approximation (GGA) using the Perdew-Burke-Ernzerhof parameterization. Moreover, the Engel-Vosko GGA formalism is also applied to optimize the corresponding potential for band structure calculations. A nonlinear dependence of the effect of the concentration (x) on the lattice constants, bulk modulus and band gaps is found. The microscopic origins of the band gap bowing parameter have been discussed. Moreover, the thermodynamic stability of the studied alloys is investigated by means of the miscibility critical temperature.