A computational study of the optoelectronic and thermoelectric properties of HfIrX (X = As, Sb and Bi) in the cubic LiAlSi-type structure

We have systematically investigated the structural, electronic, optical and thermoelectric properties of HfIrX (X = As, Sb and Bi) belonging to the 18 valence electron ABX family using first-principles density functional theory calculations. In the first phase, the structural parameters of HfIrX (X = As, Sb and Bi) in the cubic LiAlSi-type (F-43 m) structure such as the lattice parameters, the bulk modulus (B) and their pressure derivative \((B^\prime )\) are calculated using the full-potential linearized augmented plane wave method within the generalized gradient approximation GGA-PBEsol. In the second phase, investigations of electronic and optical properties were treated by the TB-mBJ exchange-correlation potentials. The third phase is devoted to the interpretation and prediction of the thermoelectric performance of our compounds by combining the results of ab initio band structure calculations and Boltzmann transport theory in conjunction with rigid band and constant relaxation time (\(\tau )\) approximations as incorporated in the BoltzTraP code. We note that, because of the existence of heavy elements in our compounds, spin–orbit coupling is added for both electronic and thermoelectric calculations in order to test the effect of spin–orbit interaction on these properties. Our results are compared with other theoretical and experimental data and provide guidance for practical applications in the fields of optoelectronics and thermoelectrics.