PbTe nanocomposites synthesized from PbTe nanocrystals

Dense lead telluride (PbTe) nanocomposites were prepared from PbTe nanocrystals synthesized employing an aqueous solution-phase reaction. This approach reproducibly synthesizes 100-150 nm nanocrystals with a high yield of over 2 g per batch. Densification using spark plasma sintering dimensionally integrated nanoscale grains within a bulk matrix, resulting in a uniform dispersion of nonconglomerated nanocrystals. Transport properties of PbTe nanocomposites were evaluated through temperature dependent resistivity, Hall, Seebeck coefficient, and thermal conductivity measurements. These nanocomposites show an enhancement in the thermoelectric properties compared to bulk polycrystalline PbTe with similar carrier concentrations. Our results also indicate a strong sensitivity to stoichiometry, surface oxygen adsorption, and porosity. (C) 2007 American Institute of Physics.