Composition- and crystallinity-dependent thermoelectric properties of ternary BixSb2-xTey films

BixSb2-xTey films with controlled compositions were synthesized by a simple and cost-effective electrode position technique followed by post-annealing, for thermoelectric applications. Tailoring the chemical composition of ternary BixSb2-xTey materials is critical to adjust the carrier concentration and carrier type, which are crucial to determine their thermoelectric performance. Herein, the composition of electrode posited BixSb2-xTey film was simply tailored by controlling the [Sb]/[Bi] ratio in the electrolytes while maintaining their dense and uniform morphology. Crystallographic properties of the BixSb2-xTey films, such as crystallinity and grain size changes, were confirmed by X-ray diffraction. Room-temperature measurements of electrical conductivity, Hall mobility, and carrier concentration revealed that the substitution of Bi with Sb decreased the carrier concentration, and increased the mobility. The Seebeck coefficient of the ternary BixSb2-xTey films transitioned between p- and n-type characteristics with an increase in the Bi content. Moreover, the mobility-dependent electrical conductivity of the Bi10Sb30Te60 film resulted in a high Seebeck coefficient owing to decreased carrier concentration of the film, leading to a power factor (PF) of similar to 490 mu W/m K-2. This is more than 10 times higher than the PF values of binary nanocrystalline Sb2Te3 films. (C) 2017 Elsevier B.V. All rights reserved.