Seebeck Coefficient and the Thermoelectric Figure of Merit in Semiconductors and Conducting Polymers.

Interest in the use of thermoelectric materials for cooling and refrigeration devices has recently intensified because of the potential of such devices for reducing the present use of chlorofluorocarbon-emitting compression cooling devices, as well as for creating a means to cool quickly to superconductor operating temperature 77 deg K. Both semiconductors and conducting polymers are being investigated. Optimization of the figure of merit for such materials now becomes imperative, e.g., via judicious doping. For such a purpose, the theoretical predictability of the necessary parameters Seebeck coefficient, electric and thermal conductivities appears desirable as a guide for relevant experimental investigations. Such analytical predictions, in terms of Fermi-Dirac functions, are presented here in a systematic fashion. They are validated by the example of recent comprehensive experimental results for certain semiconductors, and are further used here in applications to a number of conducting polymers for which some experimental data have become available.