The ground state, electronic and optical properties of the quaternary alloys BexCd1-xTeyS1-y /CdS for modeling quantum well lasers: Ab-initio study within modified Becke-Johnson exchange potential

Abstract The ground state, electronic and optical properties of the quaternary Be x Cd 1-x Te y S 1-y lattice matched to CdS substrate has been predicated in detail via first principles calculations. A full potential linearized augmented plane wave (FP LAPW) method has been employed in conjunction with the generalized gradient approximation (GGA) to investigate the influence of increasing the concentration of beryllium and tellurium atoms with 0.25 step value (0  Modified Becke-Johnson exchange potential. For all Be and Te incorporated amounts with (x = y = 0.25, x = y = 0.5 and x = 0.5,y = 0.75), the Be x Cd 1-x Te y S 1-y lattice matched to CdS substrate alloys exhibits a semiconducting behavior with a small lattice mismatching ratio, a direct narrow band gaps energies and a high refractive index. Looking forward at the predominant field of expertise of these alloys, they can be futurely exploited in the designing of quantum well lasers based on Be x Cd 1-x Te y S 1-y active layer /CdS barrier.