Preparation and Characterization of P-Type Bi_0.45Sb_1.55Te₃ Thin Film Using Pulsed CO₂ Laser

Abstract

P-type Bi 0.45 Sb 1.55 Te 3 thermoelectric material was synthesized using cold pressing process. The obtained sample was prepared in the form of pellet with a diameter of 10 mm and 2 mm thick and used as a target for laser ablation. The laser source was a pulsed CO 2 laser working at a wavelength of 10.6 μ m with a laser energy density of 2 J/cm 2 per pulse. P-type Bi 0.45 Sb 1.55 Te 3 thermoelectric thin films were deposited on Si substrates for different ablation times of 1, 2 and 3 h. The cross-section and surface morphologies of the thermoelectric films were investigated using field emission scanning electron microscopy (FE-SEM). The results show that the thickness and average particle size of the films increased from 35 to 58 nm, and 28 to 35 nm, respectively, when the ablation time was increased from 1 to 3 h. The crystalline structure of the TE films was investigated by X-ray diffraction (XRD).