Experimental Investigation into the Effect of Long Term Thermal Anneals on the Thermoelectric Properties of Silicon Germanium-Gallium Phosphide

In this report is embodied the result of an experimental investigation into the effect of thermal anneals on the thermoelectric properties of n-type silicon germanium-gallium phosphide material. The construction of apparatus for measuring the electrical conductivity, Seebeck coefficient and thermal diffusivity is described and their performance assessed. A variety of techniques are employed in an attempt to identify the mechanisms/agencies responsible for the reported enhanced thermoelectric properties of these materials after they have been subjected to high temperature thermal anneals. The results confirm that improvements in the electrical power factor of silicon germanium-gallium phosphide accompanies high temperature thermal annealing.