Thermoelectric Properties of Sb₂Te₃ Thin Films by Electron Beam Evaporation

This study applies the thermoelectric grains of Sb₂Te₃ on conductive glass to evaporate Sb₂Te₃ thin films by the electron beam evaporation method. Through experimental tests with different evaporation process parameters and film annealing conditions, thin films with better Seebeck coefficient, resistivity (ρ) and power fact (PF) can be obtained. Experimental results show that when thin films are annealed, their defects can be decreased accordingly, and carrier mobility can be enhanced to further elevate the conductivity of thin films. When the substrate temperature is set at 200 °C to fabricate Sb₂Te₃ thin films by the evaporation process and by annealing at 220 °C for 60 minutes, the Seebeck coefficient of Sb₂Te₃ thin films increase from 87.6 μV/K to 177.7 μV/K; resistivity falls from 6.21 mΩ-cm to 2.53 mΩ-cm and PF can achieve the maximum value of 1.24 10⁻³ W/K² m. Finally, this study attempts to add indium (In) to Sb₂Te₃ thin films. Indium has been successfully fabricated In₃SbTe₂ thin films. This study also analyzes the effects of In on the thermoelectric properties of In₃SbTe₂ thin films.