Ultra‐High Thermoelectric Performance in Bulk BiSbTe/Amorphous Boron Composites with Nano‐Defect Architectures

Abstract Based on the Seebeck and Peltier effects, state‐of‐the‐art bismuth telluride‐based thermoelectric materials, which are capable of direct and reversible conversion of thermal to electrical energy, have great potential in energy harvesting and solid‐state refrigerators. However, their widespread use is limited by their low conversion efficiency, which is determined by the dimensionless figure‐of‐merit (ZT). Significant enhancement of ZT is a great challenge owing to the common interdependence of electrical and thermal conductivity. Here, it is demonstrated that by incorporating nanoamorphous boron into the p‐type Bi 0.5 Sb 1.5 Te 3 , a record high ZT of 1.6 at 375 K is achieved. It is shown that a high density of nanostructures and dislocations due to the incorporation of the boron inclusions, leads to a significant reduction of thermal conductivity and improved charge transport. The findings represent an important step to further promote the development of thermoelectric technology and its widespread application in solid‐state refrigeration and power generation from waste heat.