Thickness and temperature dependence of electrical resistivity of p-type Bi0.5Sb1.5Te3 thin films prepared by flash evaporation method

Abstract

P-type Bi0.5Sb1.5Te3 thin films with thicknesses in the range 80–320 nm have been deposited by the flash evaporation method on glass substrates at 473 K. XRD and field emission scanning electron microscope were performed to characterize the thin films. The results show that the thin films are polycrystalline and the grain size of the thin films increases with increasing thickness of the thin films. Compositional analysis of the thin films was also carried out by energy-dispersive x-ray analysis. A near linear relationship was observed between the electrical resistivity and the inverse thickness of the annealed thin films, and it agrees with Tellier's model. Electrical resistivity of the annealed thin films was studied in the temperature range 300–350 K, and their thermal activation behaviour was characterized, the activation energy for conduction decreases with increasing thickness of the thin films.