Power factor of very thin thermoelectric layers of different thickness prepared by laser ablation

Room temperature conductivity and the Seebeck coefficient of thin layers prepared by laser ablation from Bi2Te3 target were explored. The power factor was calculated for samples prepared at substrate temperature of 360 degrees C with the density of the laser beam 5 J cm(-2) and at substrate temperature of 410 degrees C with the density of the laser beam 2 J cm(-2) during the deposition. Oscillations of the conductivity and the power factor with the layer thickness were observed at room temperature. The oscillations of conductivity were also verified at the temperature of 77 K. The period of oscillations depends on the preparation conditions. This behavior has been theoretically explained by the quantum size effect in the layers containing different phases and in addition, it was demonstrated by the X-ray Diffraction measurement. The behavior of the power factor of the layers is compared to the behavior of the figure of merit of the layers published earlier.