Optoelectronic and Thermoelectric Properties of Zirconium Half-Heusler Alloys RhZrX (X = P, As, Sb, Bi): an ab-initio Investigation

A full potential linearized augmented plane-wave (FP-LAPW) method based on density functional theory (DFT) was employed using various approximations to provide insight into the novel half-Heusler (HH) RhZrX (X = P, As, Sb, Bi) alloys. The total energy calculations determine materials’ stability in F-43 m structure. Trans-Blaha modified Beck Johansen (TB-mBJ) potential has been used successfully to address the issue of different band gaps in the materials. According to the electronic band structure calculations using TB-mBJ, semiconducting nature with estimated indirect band gap of 1.50 eV, 1.47 eV, 1.38 eV, and 1.18 eV in RhZrX (X = P, As, Sb, Bi) alloys, respectively, has been estimated. The RhZrX (X = P, As, Sb, Bi) HH alloys are possible candidate materials for optoelectronics applications due to their absorption in the visible and UV region. Further, for these HHs, the investigated values of static dielectric constants, ε₁(0) are reported to 16.40, 16.81, 16.97, 17.64, respectively, which obey Penn model. Semi-classical Boltzmann theory has been utilized to examine how temperature and chemical potential affect the Seebeck coefficient, electronic conductivity, electronic thermal conductivity, power factor, and Fig. of merit—all of which are significant factors to take into account when assessing a material's thermoelectric performances. The calculated low value of k_l (0.584 W/mKs) for RhZrAs is particularly encouraging for utilization in thermoelectric devices. Furthermore, these materials exhibit dynamical and mechanical stabilities.