The efficiencies of thermoelectric devices are generally limited by the properties of the available materials. This study will use ion beam modification to produce improved thermoelectric materials. By introducing defects and/or alloying elements by ion implantation, the thermal conductivity of the materials will be lowered without reducing the Seebeck coefficient or the electrical conductivity thus resulting in a higher figure of merit and making possible a higher efficiency in thermoelectric generators, coolers, etc. In Phase I silicon-germanium alloys will be deposited in thin film form, doped by ion implantation, and the relevant electrical properties will be measured. Phase II research would attempt to improve the figure of merit of the materials using ion implantation, resulting in an increase in the theoretically attainable efficiency. Since the applications of these devices indicate that their market will be international, this research would improve the nation's competitive position by advancing the state of the art and ensuring that domestic firms would have access to the latest research results.
