Effects of Sb content (x) on (Bi_1-xSb_x)₂Te₃ thermoelectric thin film deposited by effusion cell evaporator

This paper investigates the effects of the Sb content (x) on (Bi_1-xSb_x)₂Te₃ thermoelectric films with x changing widely from 0 (Sb₂Te₃) to 1 (Bi₂ Te₃). First, the XRD analysis discloses that with the Sb content (x) increasing, the phase changed gradually from Bi₂Te₃ to Sb₂Te₃ as Sb atoms replaced substitutionally Bi atoms. Further microstructure analysis reveals that an extensive grain growth occurred during post-annealing for the samples with high Sb contents. According to the measurement of electrical and thermoelectric properties, the polarity of the charge carrier and Seebeck coefficient switched n-type to p-type in the range of x = 0.45∼0.63. For the n-type samples, the power factor is highest when x = 0.18 around 46.01 μW/K² whereas Sb₂Te₃, for the p-type samples, shows the highest value, 62.48 μW/K²cm.