Palladium-Added Sb ₂ Te ₃ Thin Films: Insights into Microstructural Modifications and Thermoelectric Enhancement

High Resolution Image Download MS PowerPoint Slide This study examines the development of Pd-added Sb 2 Te 3 thin films synthesized by co-magnetron sputtering. Using precise shutter-timing deposition techniques, varying amounts of Pd were introduced to enhance thermoelectric properties. Structural analysis revealed that Pd incorporation primarily leads to the formation of a PdTe 2 secondary phase within the Sb 2 Te 3 matrix, along with improved film compactness and enhanced grain connectivity. These modifications result in increased electrical conductivity and an optimized Seebeck coefficient, including a transition from n-type to p-type conduction. The thermoelectric power factor increased significantly, reaching a maximum value of 8.1 μW cm –1 K –2 at 323.15 K (50 °C), particularly for films with optimal Pd concentration. The improved thermoelectric performance is mainly attributed to increased carrier concentration and enhanced charge transport pathways resulting from microstructural evolution, while DFT calculations indicate that local Pd incorporation may further affect the electronic structure by increasing the density of states near the Fermi level. The results underscore the dual role of Pd addition in tuning the electronic band structure and microstructural properties of Sb 2 Te 3, providing insights into phase and defect engineering for thermoelectric applications in the low- to medium-temperature range. The co-magnetron sputtering method also provides a well-controlled approach for tailoring material composition and properties.