Optimisation and selection of semiconductor thermoelements

Abstract

This chapter deals with the principles for choosing materials and for improving their thermoelectric properties. The quantity known as the power factor is defined and it is shown how it can change with the Fermi energy. A materials parameter that depends on the carrier mobility, the effective mass and the lattice thermal conductivity is introduced. It is shown how the lattice conductivity can vary from one material to another and how it varies with temperature. The effect of a small energy gap is considered. Attention is drawn to the complications that arise when the energy bands depart from their simplest form. These ideas are extended to the treatment of the thermomagnetic effects.