Epitaxial growth and thermoelectric properties of c-axis oriented Bi 1−x Pb x CuSeO single crystalline thin films
Résumé
c-axis oriented Bi1−xPbxCuSeO (0 ≤ x ≤ 0.8) single crystalline thin films have been successfully epitaxially grown on SrTiO3 (001) substrates via the pulsed laser deposition technique. Detailed X-ray diffraction and transmission electron microscopy measurements reveal the excellent c-axis and ab-plane texture of the films. As the Pb doping concentration increases, both the resistivity and the Seebeck coefficient decrease due to the increase in hole carrier concentration. The highest power factor of about 1.2 mW m−1 K−2 has been achieved in Bi0.96Pb0.06CuSeO single crystalline thin films at 673 K, which is much higher than those of polycrystalline ceramics with random orientation, suggesting that c-axis oriented BiCuSeO-based single crystalline thin films might have great potential for application in thermoelectric thin film devices.