Design of Highly Efficient Thermoelectric Materials: Tailoring Reciprocal-Space Properties by Real-Space Modification

Although restricted by the poor performance at present, thermoelectric materials for power-generation devices and solid-state Peltier coolers still possess unlimited vitality, thus capturing considerable attention. Understanding and manipulating the electrical and thermal transport mechanisms in thermoelectrics play significant roles in tailoring the properties of various thermoelectric materials. The transport behavior of electrons and phonons are closely related to the chemical composition and structure, which are defined in real space. Meanwhile, transport properties are also contingent on the band structure and phonon spectrum, both of which are represented in the reciprocal-space first Brillouin zone. Real space and reciprocal space are bridged by the Fourier transform, and the combination of real-space and reciprocal-space properties will provide more possibilities for regulating transport characteristics. Herein, a compendious discussion of the internal connection between real space and reciprocal space, and the underlying physics and chemistry is presented. Then, how the relationship between real and reciprocal space provides additional insights to govern electrical and thermal transport parameters is elaborated upon, thereby enabling the discovery and optimization of thermoelectric materials. In conclusion, specific challenges and feasible directions are discussed.