I-II-V and I-III-IV half-Heusler compounds for optoelectronic applications: Comparative ab initio study

We have investigated structural, electronic and optical properties of 96 half-Heusler materials, including compounds of I-II-V and I-III-IV types using first-principles calculations based on the density functional theory. The calculated lattice constants and band gaps are used as basis informations to select candidate materials favorable for specific optoelectronic applications. The band gap trend in the selected XYZ materials is found to be similar to the one in the zinc-blende III-V compounds. The assignment of the structures in the optical spectra and band structure transitions are investigated in detail. The predicted values of the dielectric constants for selected half-Heusler systems are close to those of the III-V binary compounds.