FP-LAPW+lo Study of Structural, Electronic, and Optical Properties of Mg1-xSrxTe Alloys

Abstract

First principles total energy calculations have been performed using the full potential linear augmented plane wave plus local orbital (FP-LAPW+lo) method within density functional theory to investigate the effects of Sr-dopant on the structural, electronic, and optical properties of Mg1-xSrxTe alloys in the rock salt crystallographic phase. The generalized gradient approximation (GGA) parameterization scheme proposed by Wu and Cohen (WC) has been used for calculating the ground state structural properties, and their deviation from Vegard's law has been discussed. The Engel-Vosko (EV) GGA functional has also been employed for electronic and optical properties of the alloy systems under study, and the results of the two GGA functionals are compared. Our calculated optical bowing in the band gap for the ternary alloys is found to be mainly caused by the charge exchange mechanism. Dielectric functions, optical conductivity, and reflectivity calculations predict the use of these alloys for technologically important optical and optoelectronic devices.