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

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 degrees C followed by sintering at 600 degrees C. A maximum ZT of 1.36 at 720K is achieved for the Pb0.98Na0.02Te 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.