Heterogeneous nanocomposites of p-type bismuth antimony telluride (Bi 2-xSbxTe3) with lead telluride (PbTe) nanoinclusions have been prepared by an incipient wetness impregnation approach. The Seebeck coefficient, electrical resistivity, thermal conductivity and Hall coefficient were measured from 80 to 380 K in order to investigate the influence of PbTe nanoparticles on the thermoelectric performance of nanocomposites. The Seebeck coefficients and electrical resistivities of nanocomposites decrease with increasing PbTe nanoparticle concentration due to an increased hole concentration. The lattice thermal conductivity decreases with the addition of PbTe nanoparticles but the total thermal conductivity increases due to the increased electronic thermal conductivity. We conclude that the presence of nanosized PbTe in the bulk Bi2-xSbxTe3 matrix results in a collateral doping effect, which dominates transport properties. This study underscores the need for immiscible systems to achieve the decreased thermal transport properties possible from nanostructuring without compromising the electronic properties.
Bibliographical noteFunding Information:
This material is based upon work supported as part of Revolutionary Materials for Solid State Energy Conversion , an Energy Frontier Research Center funded by the U.S. Department of Energy, Office of Science, and Office of Basic Energy Sciences under Award no. DE-SC0001054 , and also by the University Research Corridor . Electron microscopy was acquired in the WSU Central Instrumentation Facility on a JEOL 2010 purchased under NSF Grant DMR-0216084 .
- Bismuth telluride
- Incipient wetness
- Lead telluride