Themed collection The Chemistry of Thermoelectric Materials

Guest editor G. Jeffrey Snyder introduces this Journal of Materials Chemistry C themed issue on the chemistry of thermoelectric materials.

In this paper, we review recent advances in the development of flexible thermoelectric materials and devices for wearable human body-heat energy harvesting applications.

This review discusses about the crystal structure, chemical bonding, and the electronic band structure of tetrahedrite materials. Also, this review outlines the effect of different doping elements on the thermoelectric properties of tetrahedrite materials.

Energy filtering due to second-phase precipitation in nanocrystalline silicon may lead to remarkable improvements of its thermoelectric power factor.

Here, we review the current progress in the thermoelectrics of bismuth nanowires, the fundamentals of their advantage and limitation over bulk Bi, and their potential use for enhancing thermoelectric performance.

Strong correlation between interstitial sites and thermoelectric properties of pavonite homologue Cu_x+yBi_5−yCh₈ (Ch = S or Se) compounds.

Nanoscale layer-engineering using the combined atomic/molecular layer deposition (ALD/MLD) technique for the fabrication of oxide–organic thin-film superlattices is an attractive way to tailor the performance of thermoelectric materials as it potentially allows us to suppress thermal conductivity without significantly hindering the electrical transport properties.

We discuss representative strategies of phonon engineering by categorizing them into the methods affecting each component of thermal conductivity.

We report on the synthesis of Sb₂Te₃ nanoparticles with zT values of up to 1.5. The thermoelectric transport parameters were independently optimized, giving guidance for the design of thermoelectric materials.

An overview of computed thermoelectric properties for more than 48 000 inorganic compounds from the Materials Project (MP).

Experimental and modelling investigation of Sr/Mo (co-)doped CaMnO₃ highlighted the role of Mn³⁺ and presence of domain boundaries in thermal transport and thermoelectric properties.

Small band gap topological insulators and Weyl semimetals show excellent TE properties. We identify two mechanisms (i) asymmetry in the electronic density of states caused by band inversion at an electronic topological transition and (ii) band convergence as the key to good TE behavior of these materials.

Thermoelectrics are known as one of the emerging renewable power generation technologies.

Defect calculations have untapped potential to quantitatively determine thermodynamics of semiconductors. We present a methodology to determine solve boundaries in multicomponent systems using defect energy calculations.

PEDOT-Tos is one of the conducting polymers that displays the most promising thermoelectric properties.

We herein report the significantly improved thermoelectric performance of n-type Bi₂Te_2.7Se_0.3 polycrystalline bulks through band structure engineering achieved by Au-doping.

Thermoelectric properties of metastable metal chalcogenides degrade with thermal cycling.

Ball milling has been exploited for the preparation of Cu₅Fe_1−xMn_xS₄. These materials, which are p-type semiconductors, exhibit a figure of merit greater than 0.5 at moderate temperatures.

We combine Se alloying, SbI₃ doping and repeated hot deformation to obtain high-performance n-type Bi₂Te₃ based mid-temperature thermoelectric materials for power generation.

Investigation of electrical and thermal transport properties in powder-processed Bi₂Te_3−xSe_x thermoelectric alloys determined the optimal composition based on defect chemistry.

Promising thermoelectric materials (XYZ₂) with high band degeneracy and low thermal conductivity.

The development of reliable bonding materials for PbTe-based thermoelectric modules that can undergo long-term operations at high temperature is carried out.

Neutron powder diffraction has been used to investigate the experimental compositions of single and multiphase half-Heusler samples.

Sb₂Te₃/Ag₂Te (ST/AT) composites with ST/AT molar ratios of 1/1, 2/1, 4/1, 8/1, 16/1, and 32/1 were synthesized, and high ZT values were achieved compared with other Pb-free p-type chalcogenide thermoelectric materials.

We report an extended X-ray fine structure (EXAFS) analysis of the type-I clathrates Ba₈Ga₁₆X₃₀ (X = Si, Sn) and compare the results with the results of previous studies on X = Ge. The environment about Ba is the most disordered for X=Sn.

ZnSb is a promising low cost, non-toxic thermoelectric material, but large scale applications require development of fast and easy synthesis methods.

The average thermoelectric figure of merit ZT of n-type PbTe_1−xI_x–MgTe is successfully enhanced through nano and meso structuring.

The zT of Yb₁₄MnSb₁₁ is improved by the introduction of a light rare earth element, RE³⁺ (RE = Pr, Sm) with partially filled f-levels. The carrier concentration is reduced upon substituting RE³⁺ for Yb²⁺, adding one electron to the system and improving the zT values 30–40% over that of the pristine material.

The precipitation of skutterudite-type crystallites in germanium antimony tellurides yields intriguing materials with respect to their thermoelectric performance, especially due to a very low phononic part of the lattice thermal conductivity.

The Zintl phase Eu₅In_2−xZn_xSb₆ (x = 0, 0.025, 0.05, 0.1, 0.2) with optimized p-type carrier concentration displays a zT of up to 0.4 at ∼660 K.

The thermoelectric properties from 300–1275 K of calcium-doped La_3−xTe₄ are reported.

Synthesis and structural characterization of four compounds, isostructural, but not isoelectronic, with the thermoelectric material Yb₁₄MnSb₁₁.

A rhenium-substituted HMS sample with small islands of MnSi secondary phase has been prepared by the quenching method. Such unique microstructure leads to an enhanced thermoelectric power factor (PF) as compared to the samples prepared by other methods.

The crystal structure of single crystalline members of the solid solution series Tl(V_1−xCr_x)₅Se₈ (x = 0–1 and Δx = 0.2) was determined and the magnetic and thermoelectric properties of bulk TlV₅Se₈ were investigated.

The thermoelectric power factor of the self-assisted [010]-oriented Sb₂Se₃ is 10⁴ times higher than that of Sb₂Se₃ bulk and is comparable to that of Sb₂Se₃ nanotubes, respectively.

The crystal structure, thermal stability and high-temperature thermoelectric properties of two series of tetrahedrites prepared by different synthesis routes are reported underlining the importance of off-stoichiometry in this family of compounds.

Synthesis and electrical properties of kinetically stabilized (PbSe)_1+δ(TiSe₂)_n thin-film intergrowths are reported for 1 ≤ n ≤ 18. The carriers donated to the TiSe₂ from PbSe are diluted with increasing n, leading to a systematic increase in the Seebeck coefficient and thermoelectric power factor.

The synthesis, crystal structure, and transport properties of quaternary tetrahedral chalcogenides Cu_2.1Fe_0.9SnSe₄, Cu_2.2Fe_0.8SnSe₄ and Cu_2.2Zn_0.2Fe_0.6SnSe₄ were investigated. Cu_2.2Fe_0.8SnSe₄ has a ZT value of 0.45 at 750 K, the highest ZT thus far reported at this temperature for solid–solution compositions in this material system.

We have optimized the thermoelectric material Mg₂Si_0.8Sn_0.2 and analyzed the electronic transport employing a single parabolic band model.

The thermoelectric properties of MoSi₂-type intermetallic compound Al₆Re₅Si₄ (investigated compositions: Al_6−xRe_4.7Si_4+x (x = 0–0.9)) related to TiSi₂-type narrow band gap intermetallic compounds were systematically investigated.

The optimized carrier concentration, high effective mass and strong electron–phonon scattering for Ni doped CoSbS contribute to the enhanced ZT value.

An efficiently designed microstructure leads to a record ZT value in p-type half-Heusler compounds.

Thermal stability of Sb-doped Mg₂Si_0.3Sn_0.7 was studied by changing the heat treatment conditions (atmosphere, coating, temperature, and time).

Ruthenium oxides are typical strongly correlated electron systems, where various ordering phenomena occur through delicate interplay among the charge, spin and orbital degrees of freedom.

We demonstrate a new strategy to control the carrier transport in AgSbSe₂ by introducing Sb deficiencies. Enhanced electrical conductivity and ultra-low thermal conductivity resulted a peak ZT value ∼1 at 610 K in Sb deficient AgSbSe₂.