Enhanced thermoelectric properties in Cu-doped Sb2Te3 films

Cu-doped Sb2Te3 films were deposited at room temperature by the magnetron sputtering method, structure, microstructure and thermoelectric properties of the as-deposited and annealed films were systematically investigated. The results revealed that, while the as-deposited films were amorphous, the annealed films were crystallized into rhombohedral phase. Scanning electron microscope image showed tiny grains on the surface of the film, and element mapping confirmed the existence of Cu. The maximum electrical conductivity value of 4.6 × 104 S/m was obtained in the film with Cu-doping concentration of 4.4 at%. Although the Seebeck coefficient was decreased by Cu-doping, the maximum power factor was increased from 0.27 mW/mK2 to 0.38 mW/mK2 with higher electrical conductivity. This implies that proper concentration of Cu-doping into Sb2Te3 is promising to improve its thermoelectric property.