Fabrication by Coaxial-Type Vacuum Arc Evaporation Method and Characterization of Bismuth Telluride Thin Films

We prepared both n- and p-type bismuth telluride thin films by using a coaxial-type vacuum arc evaporation method. The atomic compositions of the as-grown thin films and several annealed thin films were comparable to that of bulk bismuth telluride. Their thermoelectric properties were measured and found to be comparable to those of bulk materials. The Seebeck coefficient and electrical conductivity of the as-grown thin films were improved by the annealing process. The measured figures of merit (ZT) of the films were 0.86 for the n-type and 0.41 for the p-type at 300 K for annealing temperatures of 573 K and 523 K, respectively.