Nanostructured Thermoelectrics

There is a need for an efficient use of energy and to find alternative clean energy sources that can substitute fossil fuels. As a consequence, energy storage and energy harvesting are being more and more considered as means to achieved this purpose. A good example is the car industry. Current vehicles are powered by fossil fuels and will be in the foreseeable future. Only a small portion (25%) of the energy supplied by the fuel is used in the vehicle propulsion, the rest being lost essentially in exhaust heat, unburnt fuel and friction. To scavenge the energy available in the exhaust heat Thermoelectric (TE) devices is the technology to be used. TE technology is available for a long period, however the current TE materials with the highest figure of merit, ZT~1 are metallic alloys, based on highly toxic components (lead, bismuth and tellurium) that pose considerable environmental concerns and with limited temperature working ranges.

The project aims at the increase of the TE efficiency of n-type semiconductor strontium titanate (STO) based oxide through a unique combined three folded approach: i) natural super lattice creation, ii) grain nano-structuring and iii) grain boundary nano-engineering, to effectively decrease the thermal conductivity, κ, thereby significantly improving ZT which can lead to the development of high efficiency oxide based TE modules.