Abstract

Mg₂Sn-based semiconductors are promising candidates for electrical and thermoelectric device applications. Mg₂Sn is a narrow-bandgap semiconductor; however, its thin-film forms have not been extensively studied. In this study, Mg₂Sn films were deposited on glass substrates by co-sputtering with a fixed RF source for the Mg target and varying the DC sputtering power for the Sn target. The results demonstrate that variations in the Sn sputtering power influenced the structural properties, surface morphology, elemental composition, and thermoelectric properties of the resultant thin films. Specifically, the results revealed a structural transition from the cubic phase to a mixed cubic-orthorhombic phase at a sputtering power of 40 W, resulting in a near- stoichiometric Mg₂Sn composition. These two factors improved the thermoelectric properties of the Mg₂Sn films, reaching a power factor of 0.72 µW/m.K². However, the Seebeck coefficients of both films remained low, primarily caused by excess metallic phases.