Carrier concentration and orientation optimization for high performance (Sb,Bi)2Te3 thermoelectric films via magnetron co-sputtering.

High performance flexible thermoelectric thin films are desired for power generation of flexible thermoelectric device. Thermoelectric performance of (Sb,Bi) 2 Te 3 films are determined by the Te content in the matrix as anti-site defect dominates the carrier concentration. By controlling the Te target co-sputtering power, annealing temperature and time, not only the film in-plane orientation is enhanced, the carrier concentration is also effectively controlled in this work. Through a systematically investigation of Te content dependence of the thermoelectric performance, the carrier concentration and orientation is optimized through tuning Te content, and a high power factor of ∼32 μ W/cm-K2 for Sb 2 Te 3 film, ∼36 μ W/cm-K2 for Bi 0.5 Sb 1.5 Te 3 film is realized in in-plane orientation. Besides, The thermal conductivity along in-plane direction is determined by photon-electro-thermal (TPET) technique, and the final zT values are ∼0.49 for Sb 2 Te 3 , and ∼0.58 for Bi 0.5 Sb 1.5 Te 3 films at room temperature, respectively. • Enhanced in-plane orientation by Te co-sputter. • Systematically Te content control and Carrier concentration optimization. • In-plane thermal conductivity measurement by photon-electro-thermal (TPET) technique. • High power factor ∼32 μ W/cm-K2 for Sb 2 Te 3 film, ∼36 μ W/cm-K2 for Bi 0.5 Sb 1.5 Te 3 film. [ABSTRACT FROM AUTHOR]