Annealing effects on the thermoelectric properties of silver-doped bismuth telluride thin films

Abstract

The structures and thermoelectric properties of n-type silver-doped Bi2Te3 thin films on SiO2/Si substrates using thermal co-evaporation method were reported. Annealing effects on the thermoelectric properties of thin films were also investigated in the temperature range 100 to 250°C under nitrogen atmosphere. The crystalline structures and morphologies were examined by X-ray diffraction and field emission scanning electron microscope. The thermoelectric properties of thin films were determined by Seebeck coefficients and electrical conductivity measurements. The results showed that as the thin film is annealed at 250°C, the Seebeck coefficient and electrical conductivity of −47.04μV/K and 976.13S·cm−1 can be obtained, respectively, which resulted in an optimum power factor of about 2.16μW/cm·K2.