Decoupling effect of electrical and thermal properties of Bi2Te3-polypyrrole hybrid material causing remarkable enhancement in thermoelectric performance

Abstract

We provided a Bi2Te3-polypyrrole hybrid material, in which energy band junction and phonon scattering effects should appear at the interface of the two components. The hybrid material exhibited increases in electrical resistivity and the Seebeck coefficient due the energy band junction, thus retaining the power factor without loss, whereas showing a great reduction in thermal conductivity because of the phonon scattering at the interface. This significant decoupling of electrical and thermal properties resulted in predominant figures of merit (ZTmax ∼ 1.21 at 100 °C and ZTave ∼ 1.18 at 50–150 °C) among n-type Bi2Te3 or Bi2(Te,Se)3 materials previously reported. © 2018 The Korean Society of Industrial and Engineering Chemistry