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Bi2Te3-based alloys are the most mature commercial thermoelectric (TE) materials for the cooling application near room temperature. However, the poor mechanical properties of the commercial zone melting (ZM) ingot severely limits the further application. Meanwhile, due to the donor-like effect, the robust polycrystalline n-type bulks usually have low TE performance near room temperature. Herein, based on the commercial ZM ingots, a high figure of merit (zT) of 1.0 at 320 K and good mechanical properties are achieved viathe hot extrusion. The dynamic recrystallization in the hot-extrusion process can suppress the donor-like effect and refine the large ZM grains into fine-equiaxed grains. Moreover, the obtained polycrystalline Bi2Te2.79Se0.21has good preferential orientation and high carrier mobility (μ). The high μand the weaken donor-like effect maintain the high power factor (PF) of 43.1 μW cm−1 K−2in the hot-extruded ZM sample. Due to the enhanced phonon scattering, the total thermal conductivity κtotdecreased to 1.35 W·m−1·K−1. To demonstrate the good mechanical properties of the extruded ZM sample, micro TE dices with the cross sections of 300 μm × 300 μm and 200 μm × 200 μm are successfully cut from the extrusion sample. This study provided a fast and low-cost extrusion technique to improve the TE and mechanical properties of the commercial ZM ingot at room temperature.

By virtue of the excellent plasticity and tunable transport properties, Ag2S-based materials demonstrate an intriguing prospect for flexible or hetero-shaped thermoelectric applications. Among them, Ag2S1-xTexexhibits rich and interesting variations in crystal structure, mechanical and thermoelectric transport properties. However, Te alloying obviously introduces extremely large order-disorder distributions of cations and anions, leading to quite complicated crystal structures and thermoelectric properties. Detailed composition-structure-performance correlation of Ag2S1-xTexstill remains to be established. In this work, we designed and prepared a series of Ag2S1-xTex(x = 0–0.3) materials with low Te content. We discovered that the monoclinic-to-cubic phase transition occurs around x = 0.16 at room temperature. Te alloying plays a similar role as heating in facilitating this monoclinic-to-cubic phase transition, which is analyzed based on the thermodynamic principles. Compared with the monoclinic counterparts, the cubic-structured phases are more ductile and softer in mechanical properties. In addition, the cubic phases show a degenerately semiconducting behavior with higher thermoelectric performance. A maximum zT = 0.8 at 600 K and bending strain larger than 20% at room temperature were obtained in Ag2S0.7Te0.3. This work provides a useful guidance for designing Ag2S-based alloys with enhanced plasticity and high thermoelectric performance.