Microstructure and High-temperature Thermoelectric Properties of InxTe0.5Co4Sb11.5 Fabricated via Microwave Synthesis Combined with Spark Plasma Sintering

In-filled and Te-doped InxTe0.5Co4Sb11.5 bulks ingots are prepared by microwave synthesis combined with spark plasma sintering. It is demonstrated that the incorporation of In and Te could optimize the carrier concentration and mobility. Maintaining a large Seebeck coefficient while significantly lowering the electrical resistivity results in a power factor of 3038.475 mu W/(m K-2). The lattice thermal conductivity is minimized to 1.66 W/(m K) by resonance scattering caused by In-filling and the defective scattering and stress field and mass fluctuations induced by Te-doping, which is 18.64% lower than that of In0.6Co4Sb12. The ZT value of InxTe0.5Co4Sb11.5 reaches 0.87 at 775 K, an improvement of 35.94% compared to similar samples. The microwave method has successfully reduced the synthesis time from several weeks with traditional techniques to just a few minutes, demonstrating the superiority of microwaves in the synthesis of Skutterudites. This approach offers a viable pathway for the industrial production of thermoelectric materials.