Low Temperature Synthesis as a Route for Highly Thermoelectric Efficient Na‐Doped PbTe

Abstract

In this work, Na-doped PbTe is synthesized through a low temperature synthesis technique. This method provides highly efficient p-type PbTe using a synthesis temperature much lower than the PbTe melting point and as low as 430 C followed by sintering at 600 C. A maximum ZT of 1.36 at 720 K is achieved for the Pb 0.98 Na 0.02 Te sample arising from a high power factor and a very low lattice thermal conductivity. The low thermal conductivity is attributed to the in situ nanostructuring achieved by the low temperature synthesis method, followed by cold pressing and sintering.

Off-Centered Pb Interstitials in PbTe

“…[1,3,4] PbTe-based materials have high thermoelectric performance for middle temperatures applications up to the hot side temperature of 800 K. [5][6][7][8][9][10][11] With Na or Bi doping, suitable charge carriers are doped and the Fermi level is positioned near the optimal band edge positions, resulting in the optimization of the power factor. [12][13][14][15] Alloying or doping with extrinsic Ag, Sb, CdTe, MgTe, MnTe, SrTe, EuTe, or Ag2Te phases leads to low lattice thermal conductivity near ~1 W/m/K. [5,6,8,9,[16][17][18] As a result, many high ZT PbTe-based materials have been developed.…”