High temperature thermoelectric properties of highly c-axis oriented Bi₂Sr₂Co₂O_y thin films fabricated by pulsed laser deposition

High-temperature thermoelectric transport property measurements have been performed on the highly c-axis oriented Bi₂Sr₂Co₂O_y thin films prepared by pulsed laser deposition on LaAlO₃ (001). Both the electric resistivity ρ and the seebeck coefficient S of the film exhibit an increasing trend with the temperature from 300 K–1000 K and reach up to 4.8 m·Ω · cm and 202 μV/K at 980 K, resulting in a power factor of 0.85 mW/mK which are comparable to those of the single crystalline samples. A small polaron hopping conduction can be responsible for the conduction mechanism of the film at high temperature. The results demonstrate that the Bi₂Sr₂Co₂O_y thin film has potential application in high temperature thin film thermoelectric devices.