Large enhancement in the thermoelectric properties of Pb0.98Na0.02Te by optimizing the synthesis conditions
- 12 July 2013
- journal article
- research article
- Published by Royal Society of Chemistry (RSC) in Journal of Materials Chemistry A
- Vol. 1 (37), 11269-11278
- https://doi.org/10.1039/c3ta11825h
Abstract
PbTe is known as a good thermoelectric material for waste heat recovery in the temperature range of 500 to 900 K. While various approaches such as nanostructuring for thermal conductivity reduction, resonant impurities, and band convergence by alloying for power factor enhancement have been proposed recently for enhancing the thermoelectric properties of PbTe, a systematic study on optimizing the synthesis conditions is also crucial to find a better base material, upon which those new approaches can be applied to further improve the material. In this paper, we systematically investigate the effect of various hot-press conditions on the thermoelectric properties of p-type 2% Na-doped PbTe, by varying the hot-press pressure from 70 to 130 MPa and the sintering time from 0.5 to 2 h. It is shown that the micro- and nano-scale structures in the hot-pressed material can be controlled by changing the sintering time and pressure. We demonstrate that by optimizing the hot-press conditions, the thermoelectric figure of merit of p-type 2% Na-doped PbTe can be enhanced up to zT = 1.74 at 774 K, which is about a 24% enhancement compared to the value of 1.4 presented by Pei et al. for the same material composition. Our electron transport modeling on bulk PbTe shows that this enhancement is due to the thermal conductivity reduction in both the electronic and lattice contributions. We believe that our findings can be accompanied with other recently-proposed techniques to further enhance the zT of this important thermoelectric material.Keywords
This publication has 33 references indexed in Scilit:
- High-performance bulk thermoelectrics with all-scale hierarchical architecturesNature, 2012
- Convergence of electronic bands for high performance bulk thermoelectricsNature, 2011
- Optimization of the thermoelectric figure of merit in the conducting polymer poly(3,4-ethylenedioxythiophene)Nature Materials, 2011
- High thermoelectric figure of merit in heavy hole dominated PbTeEnergy & Environmental Science, 2011
- Strained endotaxial nanostructures with high thermoelectric figure of meritNature Chemistry, 2011
- Cooling, Heating, Generating Power, and Recovering Waste Heat with Thermoelectric SystemsScience, 2008
- Enhancement of Thermoelectric Efficiency in PbTe by Distortion of the Electronic Density of StatesScience, 2008
- High-Thermoelectric Performance of Nanostructured Bismuth Antimony Telluride Bulk AlloysScience, 2008
- Silicon nanowires as efficient thermoelectric materialsNature, 2008
- Thermal Conductivity Reduction and Thermoelectric Figure of Merit Increase by Embedding Nanoparticles in Crystalline SemiconductorsPhysical Review Letters, 2006