Topological thermoelectrics: New opportunities and challenges

Due to the great application potential of the efficient interconversion between heat and electricity, thermoelectric materials have long been the research focal points in condensed matter physics and material science. Moreover, since the discovery of topological properties in solid materials, numerous research studies have recently expanded into the role of the topological state in thermoelectrics. Topological insulators and semimetals/metals are characterized by their exotic electronic band structures and quantum surface states, which can provide a new degree of freedom to manipulate thermoelectric properties. Herein, we present a summary on the advantageous combination of topological properties in thermoelectric materials for enhancing the thermoelectric energy conversion efficiency. We demonstrated this concept through some examples on the applications of novel topological materials as a practical strategy towards high thermoelectric performance. Furthermore, the role of different topological states and the corresponding working mechanism is explained, and the related challenges for further development are also discussed. This review article presents an advanced understanding of topological states in a thermoelectric transport mechanism, providing a new strategy to search for outstanding thermoelectric materials.