First principle calculation of mechanical stability, opto-electronic and thermo-electric properties of TaIrGe1-xSnx(0 ≤ x ≤ 1) Half-Heusler alloy

Abstract

In this study, the structural, elastic, opto-electronic and thermo-electric properties of TaIrGe1-xSnx (x = 0, 0.25, 0.50, 0.75 and 1) Half-Heusler alloy are predicted. The full potential-linearized augmented plane wave (FP-LAPW) method is used within density functional theory (DFT). The structural properties such as the equilibrium lattice parameters, bulk modulus and its pressure derivative are investigated using the PBEsol-GGA approximation, as well as elastic constants. Elastic constants obey the mechanical condition stability. The energy band structure of TaIrGe1-xSnx (x = 0, 0.25, 0.50, 0.75 and 1) alloy is computed along the high symmetry points and results show the indirect nature of the band gap, with smaller difference of energy from direct band gap nature. Thermoelectric properties of half-Heusler compounds TaIrGe1-xSnx (x = 0, 0.25, 0.50, 0.75 and 1) has been computed using semi-classical Boltzmann transport theory, TaIrGe0.5Sn0.5 has a higher value of Figure of merit with low thermal conductivity as compared to other concentrations. Our results show that TaIrGe1-xSnx (x = 0, 0.25, 0.50, 0.75 and 1) alloy can be applied as an important opto-electronics and thermoelectric material in the future.