Thermoelectric properties of (Cu,Te) co-doped CoSb3 synthesized by high-pressure and high-temperature

Amidst the escalating challenges posed by the global economic and energy crises, the significance of employing high-performance thermoelectric materials in waste heat power generation has gained prominence. Skutterudite (CoSb3), acknowledged as a mid-temperature thermoelectric material, has attracted substantial attention from researchers. In this investigation, thermoelectric compounds of (Cu,Te) co-doped CoSb3 were expeditiously synthesized through the high-pressure high-temperature (HPHT) method. XRD patterns and SEM images unveiled the CoSb3 structure of the synthesized samples, manifesting characteristics such as micro-pores and finely-grained structures of diverse scales. As the increasing of Te doping, the carrier concentration of the skutterudite increases, the resistivity significantly decreases, and the lattice thermal conductivity remains relatively unchanged, thus the thermoelectric properties of the samples are optimized. The sample Cu0 center dot 3Co4Sb11 center dot 7Te0 center dot 3 exhibited the lowest thermal conductivity of 1.97 W/(mK) at 770 K, and the sample Cu0 center dot 3Co4Sb11 center dot 5Te0 center dot 5 achieved the maximum zT similar to 0.77 at 770 K. These research findings offer valuable insights for further refinement of high-performance thermoelectric materials.