Efficient thermoelectric energy conversion in Pb0.95Mn0.05Te p-n couple
Abstract
We demonstrate an efficient energy conversion in a p-n thermoelectric couple built of bulk Pb0.95Mn0.05Te 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 Pb1-xMnxTe 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 Pb1-xMnxTe. Applying the Harman method for samples of various lengths, we experimentally determined the radiation correction factors and found the thermoelectric figure of merit parameter Z T =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.
- Publication:
-
Applied Physics Letters
- Pub Date:
- March 2016
- DOI:
- 10.1063/1.4945096
- Bibcode:
- 2016ApPhL.108m3902D