Ab Initio Computational Study of Intrinsic Half-Metallicity in Binary Alkali Metal Chalcogenides: KX (X = S, Te)

Abstract

The current article is based on first principle full-potential linearized augmented plane wave and density functional theory (DFT) that used to analyze KX (X=S and Te) potassium binary alkali–metal chalcogenides. It employed to determine the exchange-correlation energy and potential of various compounds like sodium chloride and caesium chloride in different crystalline phases utilizing the GGA and the modified Becke–Johnson method. Lattice parameters of KS and KTe are 8.586, 8.586, 5.921 and 5.659, 5.659, 12.448 respectively. The spin-polarized p orbital’s lie in group VI elements of the periodic table containing half-metallic and half-magnetic DFT simulations were used to investigate chalcogenide materials due to their wide bandgaps and strong optical absorption intensities. The KS and KTe are excellent photovoltaic and infrared sensing materials. There are two distinct bandgaps in KS: 1.29 eV direct bandgap for KS and 1.47 eV direct bandgap for KTe. The bandgaps in both formations allow for the generation of solar power. The structures with both conduction and valence bands are controlled by chromium d orbitals and chalcogenide p orbitals stoichiometrically. While the KS bands are so small, the density of states above the conduction band is substantial. Above the conduction band, there are only 15 KTe3 states/eV. The improved values may affect the industrial impact and cost with the increase in corresponding values.