Strong and efficient bismuth telluride-based thermoelectrics for Peltier microcoolers.

Thermoelectric Peltier coolers (PCs) are being increasingly used as temperature stabilizers for optoelectronic devices. Increasing integration drives PC miniaturization, requiring thermoelectric materials with good strength. We demonstrate a simultaneous gain of thermoelectric and mechanical performance in (Bi, Sb)Te, and successfully fabricate micro PCs (2 × 2 mm cross-section) that show excellent maximum cooling temperature difference of 89.

Wide-temperature-range thermoelectric n-type Mg(Sb,Bi) with high average and peak zT values.

Mg(Sb,Bi) is a promising thermoelectric material suited for electronic cooling, but there is still room to optimize its low-temperature performance. This work realizes >200% enhancement in room-temperature zT by incorporating metallic inclusions (Nb or Ta) into the Mg(Sb,Bi)-based matrix. The electrical conductivity is boosted in the range of 300-450 K, whereas the corresponding Seebeck coefficients remain unchanged, leading to an exceptionally high room-temperature power factor >30 μW cm K; such an unusual effect originates mainly from the modified interfacial barriers.

Evolution of defect structures leading to high ZT in GeTe-based thermoelectric materials.

GeTe is a promising mid-temperature thermoelectric compound but inevitably contains excessive Ge vacancies hindering its performance maximization. This work reveals that significant enhancement in the dimensionless figure of merit (ZT) could be realized by defect structure engineering from point defects to line and plane defects of Ge vacancies. The evolved defects including dislocations and nanodomains enhance phonon scattering to reduce lattice thermal conductivity in GeTe.

Thermoelectric Cu Sb S -Based Synthetic Minerals with a Sublimation-Derived Porous Network.

Pores in a solid can effectively reduce thermal conduction, but they are not favored in thermoelectric materials due to simultaneous deterioration of electrical conductivity. Conceivably, creating a porous structure may endow thermoelectric performance enhancement provided that overwhelming reduction of electrical conductivity can be suppressed. This work demonstrates such an example, in which a porous structure is formed leading to a significant enhancement in the thermoelectric figure of merit (zT).

Practical High-Performance (Bi,Sb)Te-Based Thermoelectric Nanocomposites Fabricated by Nanoparticle Mixing and Scrap Recycling.

BiTe-based compounds are the most mature and widely used thermoelectric materials. However, industrial device fabrication will inevitably produce a lot of BiTe scraps, which results in wastes of expensive material resources. In this work, we recycled -type (Bi,Sb)Te scraps and reprocessed them by making nanocomposites with nano-SiC.

Nanostructure Engineering and Performance Enhancement in FeO-Dispersed CuSbS Thermoelectric Composites with Earth-Abundant Elements.

Nanostructuring and defect engineering are increasingly employed as processing strategies for thermoelectric performance enhancement, and special attention has been paid to nanostructured interfaces and dislocations that can effectively scatter low- and mid-frequency phonons. This work demonstrated that their combination was realized in FeO-dispersed tetrahedrite (CuSbS) nanocomposites, leading to significantly reduced thermal conductivities around 0.9 W m K at all temperatures and hence a high value of ∼1.

Melt-Centrifuged (Bi,Sb) Te : Engineering Microstructure toward High Thermoelectric Efficiency.

Microstructure engineering is an effective strategy to reduce lattice thermal conductivity (κ ) and enhance the thermoelectric figure of merit (zT). Through a new process based on melt-centrifugation to squeeze out excess eutectic liquid, microstructure modulation is realized to manipulate the formation of dislocations and clean grain boundaries, resulting in a porous network with a platelet structure. In this way, phonon transport is strongly disrupted by a combination of porosity, pore surfaces/junctions, grain boundaries, and lattice dislocations.