Complex Structures: The Path to Enhanced Thermoelectric Performance
Thermoelectric materials can be used to convert wasted heat to useful electrical energy. A good thermoelectric material, as determined by its dimensionless figure of merit, should concurrently possess low thermal conductivity, low electrical resistivity and high thermopower. The modern materials synthesis approach to achieving this combination is the formation of complex structures (i.e. multiphase composites) that allow for excessive manipulation, which can be subsequently utilized to optimize electrical and thermal transport behavior.
The silver chalcogenides offer an excellent platform since, in these materials, phase competition leads to the formation of highly complex structures out of the melt, which display high thermoelectric performance. I will present the results obtained by my group on these materials, with emphasis placed on the microstructure, the corresponding electrical and thermal transport behavior and the resulting dimensionless figure of merit.