Thermoelectric properties of n-type Bi–Te thin films with deposition conditions using RF magnetron co-sputtering

Bismuth–tellium (Bi–Te) thin films were fabricated using radiofrequency (RF)-magnetron co-sputtering with various deposition conditions to improve their thermoelectric properties. The deposition conditions controlled were the working pressure and substrate temperature. The films were analyzed in terms of their crystalline structure, surface morphology, composition, Seebeck coefficient, and electrical properties. The Seebeck coefficient and electrical resistivity were measured at room temperature. The Te content and grain size decreased with increased deposition pressure and the thermoelectric performance was excellent at 0.4 Pa. The thin films with the best thermoelectric performance had a Bi2Te3 crystal structure and were formed at a deposition pressure of 0.4 Pa and a substrate temperature of 473 K.