Optimized Strategies for Advancing n-Type PbTe Thermoelectrics: A Review

Abstract

p-Type and n-type thermoelectric semiconductor materials with compatible performance are key components for thermoelectric devices. Great improvement in thermoelectric performance has been achieved in p-type PbTe, whereas the n-type counterpart still shows much inferior thermoelectric performance compared to that of the p-type PbTe. This inspires many strategies focused on advancing n-type PbTe thermoelectrics. Herein, not only effective mass engineering, resonance states, point defects, and nanostructures but also newly developed concepts including dynamic doping for stabilizing the optimal carrier concentration and introducing dislocations for reducing lattice thermal conductivity are summarized. In addition, the synergistic effects for further enhancing the thermoelectric performance are outlined, together with a discussion and outlook for boosting the advancement in n-type PbTe thermoelectric materials. Strategies discussed here are expected to be applicable to other thermoelectric materials.

Discordant Gd and Electronic Band Flattening Synergistically Induce High Thermoelectric Performance in n-type PbTe

“…8,9,30,34 On the other hand, the conduction band (CB) of PbTe is composed of only a single L band and thus it is lagging to match the performance of its p-type counterpart. 33,35 The presence of lower degenerate valleys in CB as compared to VB generates intrinsically low n-type Seebeck coefficient values and thus poses a greater challenge to improve its n-type thermoelectric performance. 33,35 Recent progress on n-type PbTe primarily focuses on optimizing charge carrier concentration and mobility, 6,17,18,36,37 simultaneously modulating the electronic and thermal properties in PbTe-Cu 2 Te 17 and PbTe-AgSbSe 2 , 38 and enhancing band effective mass as in the case of Pb 0.988 Sb 0.012 Te-GeTe, 19 Pb 0.98 Ga 0.02 Te-GeTe, 20 and PbTe-MnTe.…”

Enhancing Thermoelectrics for Small-Bandwidth n-Type PbTe–MnTe Alloys via Balancing Compromise

“…Specifically, the optimal carrier concentration ( n H , opt ) at 773 K (5.2 × 10 19 cm –3 ) differs from that at 323 K (7.8 × 10 18 cm –3 ) by nearly an order of magnitude. However, the constant carrier concentration through the conventional np 3 donor impurity is seriously inconsistent with the optimal value near room temperature. ,,− Therefore, we further carried out Hall measurements on all Cu-intercalated samples. It can be observed from Figure b that the carrier concentration of all Cu-intercalated samples has little difference at room temperature due to the low solubility of Cu in PbTe.…”

Superconductivity in In-doped AgSnBiTe3 with possible band inversion

“…From the data under 5 T, the electronic specific heat parameter (γ) and the Debye temperature (θD) were estimated as 2.35(5) mJmol -1 K -2 and 186 K, respectively. The low-temperature specific-heat formula with anharmonic term was used for the analysis: C = γT + βT 3 + δT 5 , where βT 3 is the lattice contribution to the specific heat, and the δT 5 term accounts for anharmonicity of the lattice. The θD was calculated from β = (12/5)π 4 (2N)kBθD -3 , where N and kB are the Avogadro constant and Boltzmann constant, respectively.…”

“…Metal tellurides (MTe) with a NaCl-type structure have been extensively studied due to their physical properties as topological materials [1][2][3][4] , thermoelectric materials [5][6][7] , and superconductors [8][9][10][11][12] . Among them, In-doped SnTe superconductors have been drawing attention as a candidate system of a topological superconductor 4,[13][14][15][16][17] .…”