Phosphorus-doped bismuth telluride films by electrodeposition

Phosphorus-doped Bi₂Te₃ films were synthesized on a stainless-steel electrode by electrochemical deposition. X-ray diffraction, scanning electron microscopy and transmission electron microscopy confirmed that the films are single-phased Bi₂Te₃ solid solutions with a rhombohedral structure. The as-prepared films exhibit n-type characteristics with the Hall coefficient −1.76E−2 m³ C⁻¹ and the electrical conductivity 280 S cm⁻¹. The thermal conductivity is 0.47 W m⁻¹ K⁻¹, which is as low as one-third of the value observed in the bulk material. The doped P atoms occupy the interstitial positions between the two adjacent Te(1) layers connected by Van der Waals interaction in Bi₂Te₃.