Unique nanostructures and enhanced thermoelectric performance of melt-spun BiSbTe alloys

We report a melt spinning technique followed by a quick spark plasma sintering procedure to fabricate high-performance p-type Bi0.52Sb1.48Te3 bulk material with unique microstructures. The microstructures consist of nanocrystalline domains embedded in amorphous matrix and 5-15 nm nanocrystals with coherent grain boundary. The significantly reduced thermal conductivity leads to a state-of-the-art dimensionless figure of merit ZT similar to 1.56 at 300 K, more than 50% improvement of that of the commercial Bi2Te3 ingot materials.