The 4th African Conference on Fundamental and Applied Physics (ACP2025)

First Principles Study of K2SbAu Zintl Phase Ternary Compound for Optoelectronic and Thermoelectric Applications

16 Sept 2025, 16:55

5m

Contributed Poster Presentation Physics Research Poster Room

Speaker

Dr Mwende Mbilo (Monolith Research Group, Department of Physics, Faculty of Science and Technology, University of Nairobi, P.O. Box 30197 – 00100, Nairobi, Kenya)

Description

The Zintl phased K2SbAu ternary compound, previously investigated by experimental method and hitherto unexplored by theoretical techniques, has been studied by first-principles methods.The lattice parameters of the K2SbAu ternary compound agree with the experimentally observed ones. We observe the structural stability of the K2SbAu ternary compound using the enthalpy of formation, which is found negative, confirming the thermodynamic stability and possibility of experimental synthesis. The electronic properties suggest narrow indirect band gaps of 0.78 to 1.84 eV using various approximations. Our investigation establishes that the valence bands within K2SbAu are majorly formed through hybridising Au3d and Sb2p states, whereas the hybridisation of Au2p states mainly forms the conduction band. The K2SbAu compound is mechanically stable based on the elastic investigation. Furthermore, we discovered that the compound is ductile, ionic and anisotropic. It is observed that the K2SbAu ternary compound exhibits high optical absorption in the ultraviolet-visible range. The K2SbAu compound has a computed thermoelectric figure of merit of 0.71. Therefore, based on the electronic, optical and thermoelectric properties, the K2SbAu compound is a potential candidate for optoelectronic and thermoelectric devices. Our findings thus provide insights, invoking further experimental investigations.