Thermoelectric characterization of ion beam sputtered Sb2Te3 thin films

Ion beam sputtering was used to deposit Sb2Te3 thin films on BK7 glass substrates at room temperature. The effect of annealing on the thermoelectric properties of the Sb2Te3 thin films was investigated. After the stoichiometric films were annealed at 100 oC to 400 oC for one hour, the Seebeck coefficient decreases from 190 μV K-1 to 106 μV K-1, and the conductivity increases from 1.1 x 102 S cm-1 to 2.01 x 103 S cm-1. The Power Factor is enhanced greatly from 0.40 x 10-3 W m-1 K-2 to 2.26 x 10-3 W m-1 K-2 after annealing at 400 oC. The positive Seebeck coefficient α suggests the films to be p-type. X-ray diffraction (XRD) shows that the major diffraction peaks of the films match those of Sb2Te3 and high crystalline films are achieved after annealing. These results indicate that high-quality Sb2Te3 thin films are achieved and annealing greatly improves the thermoelectric properties of the films.