Thermoelectric technology generates electricity from waste heat, but one bottleneck for wider use is the performance of thermoelectric materials. Manipulating the configurational entropy of a material by introducing different atomic species can tune phase composition and extend the performance optimization space. We enhanced the figure of merit (zT) value to 1.8 at 900 kelvin in an n-type PbSe-based high-entropy material formed by entropy-driven structural stabilization. The largely distorted lattices in this high-entropy system caused unusual shear strains, which provided strong phonon scattering to largely lower lattice thermal conductivity. The thermoelectric conversion efficiency was 12.3% at temperature difference ΔT = 507 kelvin, for the fabricated segmented module based on this n-type high-entropy material. Our demonstration provides a paradigm to improve thermoelectric performance for high-entropy thermoelectric materials through entropy engineering.

Two-step sintering efficiently enhances zT by tuning the microstructure in a wide range from atomic defects to micrometer second phase.

The practical application of eco-friendly tin telluride (SnTe) at intermediate temperature were long restricted by its relatively lower average ZT than that of state-of-art PbTe. Here, a maximal figure of...

Nanostructure engineering has improved the performance of thermoelectric materials, but the deteriorated stability of the materials at high temperatures shortens the service life of thermoelectric modules. Here, we realized a...

Eutectoid CdTe/Cu2Te precipitates and Cu interstitials leading to a superlow lattice thermal conductivity in SnTe.

The superior performance of GeTe-based materials has drawn increased attention in the community of thermoelectrics. Originating mainly from the low lattice thermal conductivity (κ l ) caused by vast planar cation vacancy defects, Sb 2 Te 3 -alloyed Sb 2 Te 3 (GeTe) 17 (Ge 17 Sb 2 Te 20 ) samples are able to realize peak ZT values of over ∼2.0 at high temperatures, displaying more promising aptitude than traditional Sb-doped Ge 18-x Sb 2 Te 20 samples. In this work, BiI 3 was doped into Sb 2 Te 3 (GeTe) 17 samples in order to produce further improvement in thermoelectric behavior. Electron microscopy characterization revealed that BiI 3 doping introduced vast anion (Te) vacancies that cluster together as additional phonon scattering sources and that these anion defects can further weaken the potential carrier concentration reduction at high temperatures, thus retaining a large power factor (∼3.4 mW m −1 K −2 at 773 K). The discovery of this anion vacancy defect, together with the planar cation vacancies, allows realization of the simultaneous modulation of electrical and thermal transport properties, resulting in a high maximum ZT value of ∼2.2 at 723 K. Our findings offer an alternative strategy for pursuing thermoelectric performance enhancement of GeTe-based systems.

The crystal structure, electronic structure, and thermoelectric properties of a half-Heusler VFeSb (HH-VFeSb) compound are investigated. The HH-VFeSb compound is successfully synthesized by arc-melting, annealing, and spark plasma sintering processes. The crystal structure of the HH-VFeSb compound is refined by Rietveld analysis of the synchrotron-orbital-radiated X-ray diffraction pattern. The refinement results reveal that the HH-VFeSb compound has a deficient HH-VFeSb crystal structure rather than an ideal HH-VFeSb structure. The 4a and 4c sites are approximately 10% deficient in V and Fe, respectively. A small amount of Fe atoms occupy 4d sites, which are typically vacant in ideal HH-VFeSb. An antisite defect between V and Fe atoms likely exists in HH-VFeSb. Based on the revealed crystal structure, the electronic structure of deficient HH-VFeSb is calculated using density functional theory, which reveals the origin of the n-type HH-VFeSb compound from the interstitial Fe atoms at 4d sites. From the comprehensive crystal and electronic structural analyses, we conclude that the V-and Fe-deficient HH-VFeSb crystal structure is the dominant reason for the electron conductivity of the HH-VFeSb compound. A maximum zT of ca. 0.35 at 550 K is obtained, which is one of the highest zT for the HH-VFeSb compound.

Alloying PbS in PbTe–3% Sb enables a fine balance between mechanical and thermoelectric properties.