Effect of Sb doping on thermoelectric properties of chemically deposited bismuth selenide films

Bi2−xSbxSe3 thin films with x = 0, 0.02, 0.04, 0.06, 0.08 and 0.10 were elaborated under optimum conditions using the arrested precipitation technique and their thermoelectric properties were studied as a function of Sb content (x). The thermoelectric power and electrical conductivity measurement have been carried out on the films in the temperature range 300–500 K. Temperature-dependent electrical conductivity measurements verified semiconducting behaviour. From the thermoelectric power measurements it follows that the dominant carriers in all these films are holes. It was observed that thermal conductivity of Bi2−xSbxSe3 film series decreases when the Sb content (x) increases. The thermoelectric power factors of films have been found to be maximum for Bi1.98Sb0.02Se3 composition at room temperature. Thermoelectric performance (ZT) in Bi2−xSbxSe3 materials increases substantially at higher temperatures suggesting that these materials are promising for high temperature applications.