Thermoelectric properties of Bi-doped PbTe composites

An experimental and theoretical study is presented for n-type Bi-doped PbTe composites with different grain sizes and doping levels. The bulk polycrystalline composites were prepared by spark plasma sintering of the nanocrystals synthesized via micro-emulsion and direct precipitation. This technique is particularly attractive due to its low cost, its reproducibility, and the control of the composition and nanocrystal size that it affords. The thermoelectric properties of the synthesized specimens were experimentally measured and theoretically modeled. Our calculations reveal that the inclusion of electron/grain and phonon/grain interface scattering is crucial for the correct description and interpretation of the measured properties. (C) 2011 American Institute of Physics. [doi: 10.1063/1.3586240]