Thermoelectric Properties of Heavily Doped n-type Pb1−x Y x Te Compounds

Abstract

Structure, transport and thermoelectric properties of Y-doped PbTe samples are reported. The combined analysis of powder x-ray diffraction patterns and scanning electron microscopy images indicates that the Pb 1Àx Y x Te samples with x = 0.015, 0.02, 0.04, and 0.06 are single phase with the NaCl-type structure. Hall effect measurements reveal that all the samples are heavily doped n-type thermoelectric materials. The substitution of trivalent Y for bivalent Pb provides additional electrons to the PbTe matrix, leading to an increase in carrier concentration at room temperature ranging from 4.36 9 10 19 cm À3 for the sample with x = 0.015 to 2.50 9 10 20 cm À3 for the sample with x = 0.06. Both electrical resistivity and the Seebeck coefficient decrease with the increase of Y content. Meanwhile, the total thermal conductivity presents a notable and unsurprising decline with the increase of Y content, which can be ascribed to the mass fluctuation effect. An optimized figure of merit, ZT, of 1.0 is achieved at 831 K for the sample with x = 0.02.

Enhanced thermoelectric performance in p-type Mg 3 Sb 2 via lithium doping

“…Through optimization on these modules, materials with electron transport characteristics of crystal and phonon transport characteristics similar to glass can be obtained. Among notable families of TE materials such as lead telluride, [12] skutterudites, [13] half-heuslers, [6] MgAgSb, [14] and so on, Zintl phase compounds are found to meet such criterions. It consists of anions (post-transition elements from group [13][14][15] and cations (alkali metal or alkaline earth metal elements) which exhibits large electronegativity difference.…”