DFT+U investigation of electronic, optical, and thermoelectric properties of YAuX (X=Si or Ge or Sn) half-Heusler alloys

Abstract

Half-heusler alloys are fascinating thermoelectric materials because they have superior mechanical and transport properties. In this study, we used dft+u calculations and the boltztrap equation to examine the electronic, optical, and thermoelectric properties of YAuSi, YAuGe, and YAuSn half-heusler alloys. The DFT+U approach predicted band gaps of 1.2767 eV, 0.611 eV, and 1.5741 eV for YAuGe, YAUSn, and YAuSi, respectively. We also observed that all materials under consideration have a broad absorption spectrum ranging from 1 eV to 12 eV, with notable peaks in the visible and UV ranges. The obtained opto-electronic properties position the three alloys as promising candidates for photovoltaic applications. Finally, thermoelectric property calculations revealed that the figure of merit values for YAuSi, YAuGe, and YAuSn HH alloys were 0.730, 0.726, and 0.736 at 800 K, respectively suggesting the materials are also suitable candidates for application in the field of thermoelectricity