Effect of Substrate Temperature on the Thermoelectric Properties of the Sb₂Te₃ Thin Films Deposition by Using Thermal Evaporation Method

Abstract

The antimony‐telluride (Sb 2 Te 3 ) thermoelectric thin films were prepared on SiO 2 /Si substrates by thermal evaporation method. The substrate temperature that ranged from room temperature to 150°C was adopted to deposit the Sb 2 Te 3 thin films. The effects of substrate temperature on the microstructures and thermoelectric properties of the Sb 2 Te 3 thin films were investigated. The crystal structure and surface morphology of the Sb 2 Te 3 thin films were characterized by X‐ray diffraction analyses and field emission scanning electron microscope observation. The RT‐deposited Sb 2 Te 3 thin films showed the amorphous phase. Te and Sb 2 Te 3 phases were coexisted in the Sb 2 Te 3 ‐based thin films as the substrate temperature was higher than room temperature. The average grain sizes of the Sb 2 Te 3 ‐based thin films were 39 nm, 45 nm, 62 nm, 84 nm, and 108 nm, as the substrate temperatures were 50°C, 75°C, 100°C, 125°C, and 150°C, respectively. The Seebeck coefficients, electrical conductivity, and power factor were measured at room temperature; we had found that they were critically dependent on the substrate temperature.