Coupled hydrothermal synthesis/hot pressing of PbSe/C@PbTe heterostructured composites with enhanced thermoelectric performance

PbTe coated amorphous carbon sphere core-shell structure (C@PbTe) was embedded into PbSe nanopowders and subsequently assembled into macroscopic composites by hot pressing. Thermoelectric properties of the samples with 0, 1, and 5 wt% C@PbTe additions were examined between 300 and 550 K. Enhanced Seebeck coefficient and lower thermal conductivity are obtained in the PbSe/1 wt% C@PbTe sample. The maximum figure of merit ZT is 0.54 at 400 K, showing a 13% improvement over that of the PbSe matrix. These findings facilitate the application of hydrothermally synthesized carbon spheres in thermoelectric materials and also provide a potential direction to enhance thermoelectric performance via constructing core-shell structures.