Optoelectronic and thermoelectric properties of the K2SbAu zintl phase ternary compound using first principles methods

Publication Type

Journal Article

Name of Author

• Ibrahim Musanyi, Monolith Research Group, Department of Physics, Faculty of Science and Technology, University of Nairobi, Kenya
• Mwende Mbilo, Monolith Research Group, Department of Physics, Faculty of Science and Technology, University of Nairobi, Kenya
• Robinson Juma Musembi, University of Nairobi, Nairobi, Kenya
• John Kachira, Monolith Research Group, Department of Physics, Faculty of Science and Technology, University of Nairobi,Nairobi, Kenya
• Francis Nyongesa, Monolith Research Group, Department of Physics, Faculty of Science and Technology, University of Nairobi, Nairobi, Kenya
• Martin Nyamunga, Monolith Research Group, Department of Physics, Faculty of Science and Technology, University of Nairobi, Nairobi, Kenya
• Samuel Wafula, Monolith Research Group, Department of Physics, Faculty of Science and Technology, University of Nairobi, Nairobi, Kenya

Publication Date (Issue Year)

2025

Journal Name

Computational Condensed Matter

Abstract

This study investigates the K2SbAu ternary compound using first-principles methods grounded in density functional theory (DFT) to advance optoelectronic technology. The comprehensive analysis predicts the structural, electronic, elastic, mechanical, thermodynamic, optical, and thermoelectric properties of the compound. The lattice parameters of K2SbAu align with experimentally observed values. Structural stability was confirmed through the enthalpy of formation, which was negative, indicating thermodynamic stability and the feasibility of experimental synthesis. The electronic properties reveal narrow indirect band gaps ranging from 0.78 to 1.84 eV, depending on the approximation used. The study establishes that the valence bands in K2SbAu are primarily formed through the hybridization of Au3d and Sb2p states, while the hybridization of Au2p states mainly forms the conduction band. The compound was found to be mechanically stable based on elastic analysis and was characterized as ductile, ionic, and anisotropic. K2SbAu exhibited high optical absorption in the ultraviolet–visible range. The computed thermoelectric figure of merit was 0.71. Consequently, based on its electronic, optical, and thermoelectric properties, K2SbAu is a promising candidate for optoelectronic and thermoelectric devices. These findings provide a foundation for further experimental investigation.

Keywords

DFT, metaGGA, Thermoelectric, Zintl-phase, Semiconductor, K2SbAu

Grantee Name(s)

Robinson Juma Musembi

Project Title

Self-cleaning solar module for enhanced electrical output

Type of Grant

Research Award

Thematic Area

Energy including Renewables

Funding Statement

The authors acknowledge the University of Nairobi for its resources in doing this work and the Centre for High-Performance Computing (CHPC-RSA) for its computing resources through account number MATS1321.

Recommended Citation

Musanyi, I., Mbilo, M., Musembi, R. J., Kachira, J., Nyongesa, F., Nyamunga, M., & Wafula, S. (2025). Optoelectronic and thermoelectric properties of the K2SbAu zintl phase ternary compound using first principles methods. Computational Condensed Matter https://doi.org/10.1016/j.cocom.2025.e01073