Thermoelectric materials

Abstract

In this chapter, the chemistry of the thermoelectric materials is discussed. First a basic introduction to the thermoelectrics phenomena, fundamental materials parameters, and potential device applications is provided. Then, basic approaches to optimize thermoelectric properties are discussed by relating phonon and electronic structure to heat and charge transport properties, respectively, in both single-phase materials and multi-phase composites. The next four sections cover selected examples from different families of materials to emphasize the chemical and structural diversity of thermoelectrics, to provide examples of state-of-the-art thermoelectric materials, and to illustrate the aforementioned optimization strategies. The described materials include: classic thermoelectric materials, such as Bi$_2$Te$_3$ and Si-Ge alloys; tetrel monochalcogenides with record-high thermoelectric performance at elevated temperatures; earth-abundant, inexpensive, and environmentally-benign Mg-containing thermoelectrics; as well as compounds with complex crystal structures that exhibit atomic disorder and rattling species that aid in decoupling electron-phonon interactions.