Thermoelectric properties of Pb-doped bismuth telluride thin films deposited by magnetron sputtering

Abstract

Nanocrystalline n-type bismuth telluride (Bi2Te3) thin films doped with lead (Pb) were deposited by radiofrequency magnetron sputtering. The effects of Pb doping on the carrier concentration and the thermoelectric properties of the Bi2Te3 thin film were investigated. Optimization of the carrier concentration significantly increased the Seebeck coefficient of the Bi2Te3 film and reduced the carrier thermal conductivity. These phenomena contributed to the enhancement of the thermoelectric properties of the Bi2Te3 film. Power factors of 2.50 and 2.15mWK−2m−1 were achieved at 473K for the as-deposited and annealed Bi2Te3 films with Pb doping concentration of 0.38at.%, respectively. The experimental data demonstrate that Pb doping can effectively control the carrier concentration of the n-type Bi2Te3 film. The Pb-doped Bi2Te3 film is a promising material for thermoelectric microdevices.