Recent progress brought by generalized thermoelectric theory and material design in the search of good thermoelectric materials

Abstract

In this decade, several notable developments have been brought in the field of thermoelectric energy conversion. Firstly, several new materials having thermoelectric figure of merit exceeding that of state-of-the-art thermoelectric materials have been found. Secondly, several general theoretical approaches have clarified electronic structures, which good thermoelectric materials should have. Namely, they suggest that materials having narrower differential conductivity offer larger thermoelectric figure of merit. It is truly interesting that recent interesting topics, such as high-T_c superconductivity and giant magnetoresistance achieved in Manganite, are found among materials having narrow band width, where electron-electron correlation is essential. Low dimensional carrier systems achieved in semiconductor heterostructures are expected to be another possible good thermoelectric materials, since they are expected to present narrower differential conductivity. However, careful theoretical examination of such systems have not been made.
In this paper, recent progress on thermoelectric theory has been reviewed. Furthermore, thermoelectric figure of merit of low dimensional systems will be discussed based on numerical simulation of thermoelectric properties of these systems.