Efficient thermoelectric energy conversion in Pb_0.95Mn_0.05Te p-n couple Available to Purchase

We demonstrate an efficient energy conversion in a p-n thermoelectric couple built of bulk Pb_0.95Mn_0.05Te crystals grown by the Bridgman method and heavily doped n-type with Bi (⁠$n=1.9×1019cm−3$⁠) or p-type with Na (⁠$p=2.3×1019cm−3$⁠). Substitution of Mn²⁺ ions for Pb²⁺ ions at the rock-salt lattice cation sites increases the band gap of Pb_1−xMn_xTe and decreases the energy separation between the light hole L-band and the heavy hole Σ-band. It results in a large increase of thermoelectric power and improved thermoelectric parameters of p-type Pb_1−xMn_xTe. Applying the Harman method for samples of various lengths, we experimentally determined the radiation correction factors and found the thermoelectric figure of merit parameter $ZT=0.75–0.8$ at $T=650 K$ for both n- and p-type materials with good thermoelectric matching of the couple. We report on thermoelectric performance of a p-n thermoelectric couple assembled of these materials and tested over the $T=300–670 K$ temperature region.