Microstructure and Thermoelectric Properties of Mechanically Robust PbTe-Si Eutectic Composites


Sootsman J. R. , He J., Dravid V. P. , Ballikaya S. , Vermeulen D., Uher C., ...More

CHEMISTRY OF MATERIALS, vol.22, no.3, pp.869-875, 2010 (Journal Indexed in SCI) identifier identifier

  • Publication Type: Article / Article
  • Volume: 22 Issue: 3
  • Publication Date: 2010
  • Doi Number: 10.1021/cm9016672
  • Title of Journal : CHEMISTRY OF MATERIALS
  • Page Numbers: pp.869-875

Abstract

The microstructure and thermoelectric properties of the PbTe-Si eutectic system are presented in detail, When rapidly quenched from the melt this system yields materials with thermoelectric properties similar 101 PbTe itself but with improved mechanical properties. Doping optimization was performed using Pbl(2) as an n-type dopant giving precise con trol of the thermoelectric properties. Electron microscopy indicates that the PbTe-Si system is both a nanocomposite and microcomposite. Despite the added Si, the thermal conductivity of this composite follows closely that of PbTe. The temperature dependence of the Lorenz number was estimated, and it shows a significant departure from the value of metals (L-0) reaching only 45% of L-0 at 650 K. The optimized ZT for the PbTe-Si(8%) eutectic was 0.9 at 675 K. The improved mechanical robustness of these composites makes them attractive for use in large scale thermoelectric device fabrication.