The existing methods of synthesis of thermoelectric (TE) materials remain constrained to multi-step processes that are time and energy intensive. Here we demonstrate that essentially all compound thermoelectrics can be synthesized in a single-phase form at a minimal cost and on the timescale of seconds using a combustion process called self-propagating high-temperature synthesis. We illustrate this method on Cu2Se and summarize key reaction parameters for other materials. We propose a new empirically based criterion for sustainability of the combustion reaction, where the adiabatic temperature that represents the maximum temperature to which the reacting compact is raised as the combustion wave passes through, must be high enough to melt the lower melting point component. Our work opens a new avenue for ultra-fast, low-cost, large-scale production of TE materials, and provides new insights into combustion process, which greatly broaden the scope of materials that can be successfully synthesized by this technique.

Polycrystalline higher manganese silicides (HMS) Mn(Al x Si 1Àx ) 1.80 (x = 0 to 0.009) were prepared by a rapid melt-spinning process combined with a spark plasma sintering method (MS-SPS). The phase composition, microstructure, and thermoelectric properties of the bulk samples were investigated. X-ray diffraction (XRD) patterns showed that all samples possessed the HMS structure, but minor amounts of the MnSi phase could be observed from the backscattered electron images. When the Al content did not exceed the solid solubility limit, the electrical conductivity of Al-doped HMS increased dramatically, and the thermal conductivity decreased, as a result of the enhancement of phonon scattering due to an increased number of defects. In addition, the maximum ZT value of 0.65 was obtained at 850 K for the sample with x = 0.0015, whereas further increase in the Al content (x > 0.0015) significantly deteriorated the thermoelectric properties, mainly because the Al content exceeded its solid solubility limit in HMS.

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High‐performance thermoelectric BiCuSeO ceramics have been prepared by solid state reaction combined with plasma activated sintering (PAS). Phase compositional and microstructural studies indicate composites having refined grain sizes (600–700 nm) with nanostructured ZnSe secondary phase. Our results reveal that Zn doping can lead to a large change in the carrier concentration (from 0.036 × 1020 cm−3 to 1.50 × 1020 cm−3), thus resulting in an increased electrical conductivity of three orders of magnitude at room temperature. The highest power factor of 4.21 µWcm−1K−2 at 873 K has been achieved by 10% Zn doping. On the other hand, the lattice thermal conductivity has been suppressed significantly due to refined grains, point defects and the nano‐inclusions of ZnSe phase. The dimensionless figure of merit (ZT) could reach up to 0.90 at 873 K in the BiCuSeO oxyselenides by the 10% Zn doping, which makes Zn‐doped BiCuSeO to be a promising candidate for thermoelectric applications.