TB-mBJ calculations of optical and thermoelectric properties of half-Heusler FeCrAs alloy

The optical and thermoelectric properties of FeCrAs half-Heusler are carried out by employing full potential linearized augmented plane wave method. In order to have, a precise band gap value, the TB-mBJ potential is employed. The density of states and spin-polarized band structures analysis, confirm the ferromagnetic half-metallic behavior and reveal that the FeCrAs has an indirect bandgap in spin-down (↓) channel, while the spin-up (↑) channel exhibits a metallic behavior. The important optical coefficients such as dielectric function, reflectivity, absorption coefficient and refractive index are given in the ultraviolet, visible and near-infrared range. The FeCrAs can be employed as effective ultraviolet absorber due to its high absorption coefficient of 139.104/cm and a wide absorption band. The properties, which describes the thermoelectric characteristics such as Seebeck coefficient (S), thermal and electrical conductivity and Merit factor (ZT), were obtained via the BoltzTraP code. A high ZT of about 0.99 in the p- and n-type region was obtained, what makes this compound very useful for thermoelectric applications.