Synergetic Approach for Superior Thermoelectric Performance in PbTe-PbSe-PbS Quaternary Alloys and Composites

Abstract

Thermoelectric power generation is an energy conversion technology from heat to electric energy, which can be applied to waste heat power conversion. Among thermoelectric materials (TE), PbTe-PbSe-PbS quaternary alloys and composites are promising candidates for thermoelectric power generation applications in the mid-temperature operating range from 500 to ~850 K. Besides, the thermoelectric performance of quaternary alloys and composites is not fully optimized regarding its composition and synthesis process. In the quaternary system, PbTe-PbSe-PbS, it was found that PbS will form nanoprecipitation in the matrix of quaternary alloy for a small content of PbS (≤0.07), which reduces the lattice thermal conductivity. The power factor of PbTe-PbSe-PbS quaternary alloys can be significantly enhanced by using a band convergence in PbTe1−xSex. The band structure modifications, with the result of simultaneous PbS nanoprecipitation, give rise to a high Z T value of 2.3 at 800 K for (PbTe)0.95−x(PbSe)x(PbS)0.05. The chemical potential tuning by effective K-doping ( x = 0.02) and PbS substitution reveals a high power factor and low thermal conductivity, resulting in a comparatively high Z T value of 1.72 at 800 K. The combination of a high Seebeck coefficient and low thermal conductivity results in a very high Z T value of 1.52 at 700 K as n-type materials for low Cl-doped ( x = 0.0005) (PbTe0.93−xSe0.07Clx)0.93(PbS)0.07 composites. Therefore, this review presents the simultaneous emergence of effective chemical potential tuning, band convergence, and nanoprecipitation, giving rise to a significant enhancement of the thermoelectric performance of both p - and n -type PbTe-PbSe-PbS quaternary alloy and composite TE materials.

Thermoelectric properties of the bismuth oxychalcogenides Bi2SO2, Bi2SeO2 and Bi2TeO2

“…The high performance of PbTe has been linked to 'band convergence' at high temperature [11] and to strong intrinsic phonon anharmonicity [12][13][14], although the extent of the latter is disputed [15,16]. However, the environmental toxicity of Pb and the rarity of Te means both materials are unsuitable for mass-produced TEGs, and considerable effort is being devoted to alternatives including alloys of Bi 2 Te 3 and PbTe with other chalcogens [17][18][19][20] and other chalcogenides such as the flagship TE material SnSe [21][22][23][24][25][26].…”

Thermoelectric Properties of the Bismuth Oxychalcogenides Bi2SO2, Bi2SeO2 and Bi2TeO2

“…The high performance of PbTe has been linked to "band convergence" at high temperature [11] and to strong intrinsic phonon anharmonicity, [12,13,14] although the extent of the latter is disputed. [15,16] However, the environmental toxicity of Pb and the rarity of Te means both materials are unsuitable for mass-produced TEGs, and considerable effort is being devoted to alternatives including alloys of Bi 2 Te 3 and PbTe with other chalcogens [17,18,19,20] and other chalcogenides such as the flagship TE material SnSe. [21,22,23,24,25,26] While chalcogenides have the advantage of favourable electrical properties and low lattice thermal conductivity, a major drawback is that they are prone to oxidation and can degrade or decompose at high temperature.…”

Electron Paramagnetic Resonance Study of PbSe, PbTe, and PbTe:In Semiconductors Obtained by the Pulsed Laser Deposition Method

“…Due to the metallic conductivity of composites, the skin effect limits the penetration depth of microwave radiation to approximately10 µm, resulting in an asymmetrical (dissonant) shape of the resonance lines [ 24 ]. The most interesting effects related to the influence of electronic properties of semi-magnetic semiconductors on their magnetic behavior are observed in the IV–VI groups of semiconductors, such as PbSe or PbTe [ 25 , 26 , 27 , 28 , 29 ]. Interesting ferromagnetic properties have been observed in many diluted magnetic semiconductors (DMS), e.g., ZnTe + Mn [ 30 ] and CdTe + Cr [ 31 ].…”