Design of nanostructured thermoelectric materials using nanoparticles and the mechanisms for improving performance

Thermoelectric (TE) power generation, in which heat is converted directly to electricity is considered to be an environmentally friendly method. However, the parameters determining TE performance are intricately intertwined. Recently, there has been an increase in the number of reports of nanostructured TE materials made using nanoparticles (NPs). The incorporation of NPs into TE materials can produce a variety of structures such as nanoinclusions and hierarchical defects. Through this approach, the thermal and electrical transport properties can be modulated in a different way to bulk TE materials. TE NPs produced by wet chemical synthesis have customizable designs and can be used as building blocks to be assembled into a nanostructured material - either alone or in combination with other NPs or powdered materials. In this review, we introduce the preparation methods of TE NPs, the principles behind and the benefits of using NPs to enhance TE performance as well as some actual examples. The aim of this review is to provide ideas to researchers in the TE field for the possible applications of NPs in order to increase TE performance.