Unveiling the Thermoelectric Properties of Some Bismuth Based Half Heuslers: A First‐Principles Perspective

ABSTRACT Half Heusler (hH) materials are considered potential options for thermoelectric technologies, offering potential solutions to the growing global energy demand. This study investigates the electronic, lattice dynamics, mechanical, and thermoelectric properties of 18 VEC Bismuth based hH's NbRuBi, NbOsBi, and TaFeBi using density functional theory, and semiclassical Boltzmann transport theory. Due to the presence of heavier element bismuth, all calculations are performed with considering SOC. The compounds under study are thermodynamically, dynamically and mechanically stable. They exhibit semiconducting behavior with indirect bandgaps of 0.38, 0.27, and 0.86 eV for NbRuBi, NbOsBi, and TaFeBi, respectively. The charge transport parameters w.r.t. chemical potential () and carrier concentration () were performed for different temperatures. At 1100 K, the maximum power factors () for p‐type carriers are found to be 73.59 Wcm −1 K for NbOsBi, 66.70 Wcm −1 K for NbRuBi, and 69.70 Wcm −1 K for TaFeBi. The room temperature are found to be less than 12 Wm K . The combination of high and low in these compounds results an optimal p‐type , with NbRuBi achieving the highest value of 1.48 at 1100 K. Our study reveals that these materials have potential for high temperature thermoelectric applications and may attract experimental interest.