Nano-SiC in Cu2Se could facilitate liquid-like behavior to remarkably enhance electrical transport and suppress thermal conductivity simultaneously.

BiCuSeO@SnO2 core-shell nanostructures can introduce multiple potential barriers in SnTe to enhance energy filtering effect.

SnTe has attracted more and more attention due to the similar band and crystal structure with high performance thermoelectric materials PbTe. Here, we introduced Pd into SnTe and the valence band convergence was confirmed by first-principles calculation. In the experimental process, we found that Pd-doped SnTe exhibit a reduced thermal conductivity because of softening chemical bonds and grain refining effects. To further improve the thermoelectric performance, Pd–In codoped SnTe samples were prepared, and the abnormal change of thermal conductivity was observed. The results of synchrotron powder diffraction suggest that the local phase transition (local structural distortions) near 400 K results in the first turn on thermal conductivity. Similarly, the second local phase transition in near 600 K observed by neutron powder diffraction lead to a decrease thermal conductivity of the sample. Finally, a peak thermoelectric figure of merit (ZT) ≈ 1.51 has been obtained in Sn0.98Pd0.025In0.025Te at 800 K.

Mg3Sb2-based thermoelectric materials have recently received heightened attentions due to its diverse merits of high band degeneracy, ultralow lattice thermal conductivity and high carrier mobility. However, the inherently low carrier...

The introduction of special alloy nanoparticles and elemental elements in the matrix can synergistically optimize the thermoelectric properties of SnTe. Here, MgAgSb alloy nanoparticles and 0.5 mol % In are co-doped into SnTe to optimize electrical and thermal properties, which finally make the thermoelectric performance greatly improved. The improvement of Seebeck coefficient results from the valence band convergence because of the presence of Ag, Mg, and Sb atoms and a resonant state generated by doping In element. In addition, the carrier mobility is enhanced owing to the decrease of Sn vacancies caused by the doping. A high power factor (17.67 μW cm −1 K −2 ) can be obtained in Sn 1.025 In 0.005 Te-3%MgAgSb sample at 835 K. Doping multielement alloy could also effectively improve the thermal properties by scattering phonons in each frequency band, which cannot be realized merely by doping single element. This strong phonon scattering is derived from point defects and particles produced by doping MgAgSb. Extremely low thermal conductivity is achieved with the value of 1.046 W m −1 K −1 at 835 K. Finally, we acquire a high ZT of 1.41 at 835 K in Sn 1.025 In 0.005 Te-3%MgAgSb.

Enhancement of thermoelectric figure of merit by the insertion of multi-Enhancement of thermoelectric figure of merit by the insertion of multi-walled Enhancement of thermoelectric figure of merit by the insertion of multi-walled carbon nanotubes in α-MgAgSb carbon nanotubes in-MgAgSb

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emission, noiseless, friendliness for miniaturization, and reliability. [1,2] Based on the Seebeck and Peltier effects, thermoelectricity enables a direct energy conversion between temperature difference and electricity. [3] The performance of a TE material is primarily gauged by the material's figure of merit, zT = α 2 T/ρκ, where α is the Seebeck coefficient, T is the absolute temperature, ρ is the electrical resistivity, and κ is the total thermal conductivity (consisting of the lattice thermal conductivity κ L and the electronic thermal conductivity κ E ).In view of the adversely interdependent S, ρ, and κ, attaining high zT values entails hierarchical diverse structurefunctional modules in the material. To this end, "hybrid crystal" or "structural modularity" is preferred in TE materials research as these complex materials are composed of building modules with distinct compositions and functions, [4,5] through which the adverse coupling of S, ρ, and κ can be eased and tuned selectively. Layered cobalt oxides, [6] filled skutterudites, [7] meta-phases, [8] and liquid-like TE materials [9] are good examples To date, thermoelectric materials research stays focused on optimizing the material's band edge details and disfavors low mobility. Here, the paradigm is shifted from the band edge to the mobility edge, exploring high thermoelectricity near the border of band conduction and hopping. Through coalloying iodine and sulfur, the plain crystal structure is modularized of liquid-like thermoelectric material Cu 2 Te with mosaic nanograins and the highly size mismatched S/Te sublattice that chemically quenches the Cu sublattice and drives the electronic states from itinerant to localized. A state-of-the-art figure of merit of 1.4 is obtained at 850 K for Cu 2 (S 0.4 I 0.1 Te 0.5 ); and remarkably, it is achieved near the Mott-Ioffe-Regel limit unlike mainstream thermoelectric materials that are band conductors. Broadly, pairing structural modularization with the high performance near the Mott-Ioffe-Regel limit paves an important new path towards the rational design of high-performance thermoelectric materials.