Optimisation of the Thermoelectric Figure of Merit in Fine Grained Semiconductor Materials Based upon Lead Telluride.

The objective of the investigation to date has been to obtain an estimate of the possible relative improvement in material performance due to phonon-grain boundary scattering. The theoretical model employed in the calculations is relatively insensitive to the choice of value taken for parameters such as effective mass and to the nature of the energy surfaces. As indicated in the previous report the immediate task is to develop a more realistic model and work is proceeding towards this objective.