Influence of Annealing Atmospheres on the Structural and Thermoelectric Characteristics of Sb2Te3 Thin Film

The antimony telluride (Sb₂Te₃) thin films were deposited on 1-μm SiO₂ / Si-wafer substrates for a thickness of approximately 250 nm by using pulse-dc magnetron sputtering method to investigate their thermoelectric (TE) properties. This study examined the impact of post-annealing at 250°C under vacuum, argon (Ar), and nitrogen (N₂) atmospheres on the thermoelectric (TE) properties. The surface morphology, crystalline structure, and atomic composition were analyzed for both as-deposited and post-annealed thin films using field emission scanning electron microscopy (FE-SEM), grazing incidence X-ray diffraction (GI-XRD) and Energy Dispersive X-ray Spectroscopy (EDS), respectively. The results revealed that post-annealing significantly influenced the thin film structure, enhancing the Sb₂Te₃ crystal orientations, particularly the (015) and (101̅0) peaks. Additionally, post-annealing in all confirmed the electrical properties by Hall effect that provided further insights into the electrical properties of all samples. While the thermoelectric (TE) properties confirmed p-type Sb₂Te₃ through Seebeck coefficient analysis in low temperature and exhibited highest value of 1.0 x 10^-4 V/K in sample post-annealed in argon resulting to maximum power factor (PF) achieved was 4.40 x 10^-4   W/m K^-2. It was evident that the post-annealing temperature directly affected both the electrical and thermoelectric characteristics.