Thermoelectric performance of single elemental doped n-type PbTe regulated by carrier concentration.

Abstract Single elemental doped n-type PbTe compounds were successfully prepared with high pressure synthesis followed by spark plasma sintering. Thermoelectric properties investigation indicates the performance of these samples is regulated by the carrier concentration. For each doping element, the maximal ZT increases and occurs at higher temperature with increasing carrier concentration. However, the average ZT over the measurement temperature range is getting smaller due to substantially smaller ZT at low temperature. For the optimal carrier concentration near 1 × 1019 cm−3, a relatively high average ZT of ca. 0.7 is achieved for most of the doping elements. Since the average ZT determines the device performance of thermoelectric materials, our study can serve as a basis for further performance enhancement of n-type PbTe through combining strategies of dynamic doping and/or hierarchical phonon scattering. Highlights • n-type elemental doped PbTe are synthesized under high pressure. • ZT avg over 300–800 K is regulated by carrier concentration (n) with an optimal n of ca. 1 × 10−19 cm−3. • For the optimal n , relatively high ZT avg values about 0.7 is maintained for most of the doping elements. • Current work can serve as a basis for further ZT enhancement via introducing additional deep level dopant. [ABSTRACT FROM AUTHOR]