Electronic and Structural Properties of Li1 - xKxMgN Half Heusler Alloy

Metin Aslan

Abstract: I have performed the first-principles method to determine the electronic properties of cubic Li1-xKxMgN Half-Heusler semiconductor alloy using density functional theory with x=0, 0.25 0.75, 1. The exchange and correlation effects are treated using a generalized gradient approach based on Perdew et al. I have used modified Becke-Johnson potential to obtain accurate band gap results. From the electronic band gap calculation, I have found that the direct band gap of the alloy varies from 1, 39 eV to 3, 07 eV. Because of the bandgap range, Li1-xKxMgN can be a good candidate for visible and IR optoelectronic applications. From the structural calculation, I have found that the lattice parameter of cubic Li1-xKxMgN varies from 4.97 A to 5.91 A. This range allows the alloy to grow on many common substrates like Si, GaAs, Ge, InP. Finally, I have also calculated the density of states in order to understand some properties of the materials, such as the band structure, bonding characters, and dielectric functions.

Keywords: Half-Heusler, Semiconductors Alloys, Density Functional Theory, Electronic Properties, Structural Properties