Thermoelectric materials

Abstract

Thermoelectricity thermoelectricity is one of the oldest phenomena to be observed in semiconductors, with discovery of the various thermoelectric effects dating back to the early part of the 19th century. These effects manifest themselves as the appearance of a voltage in a circuit comprised of two different conductors due to a temperature difference (Seebeck effect Seebeck effect ), or as the absorption and evolution of heat at the junction of two different materials under electrical current excitation (Peltier effect Peltier effect ). These effects can be utilized in devices to generate electrical power from waste heat or to provide solid state cooling, respectively. This chapter reviews the main factors governing thermoelectric effects in solids, and how these factors may be manipulated to produce materials with high thermoelectric figure of merit. The first portion of the chapter covers the main features that determine electrical and thermal transport in crystalline semiconductors, while the latter portion discusses several new approaches to this old problem that hold promise for highly efficient thermoelectric materials in the future.