Thermoelectric materials-based on organic semiconductors

Thermoelectric properties of organic semiconductors have recently attracted attention owing to their remarkable electrical conductivity, power factor, and figure of merit. Herein, the authors first simply introduce the history of the organic thermoelectric materials; then, they summarize the recent efforts toward improving the thermoelectric properties of p- and n-type organic semiconductors. The p-type semiconductors have been divided into two groups: poly(3,4-ethylenedioxythiophene)-based materials, doped during the polymerization, and the others, which are typically nonconductive and can be molecularly doped after film formation. A couple of examples of n-type organic thermoelectric materials are also presented. Finally, the anisotropic thermoelectric properties and their measurements are discussed.