Thermoelectric cobaltate grown on silicon

Thin films made of so-called thermoelectric materials could be used to convert heat directly into electric energy, or visa versa, for a variety of applications, including micro-chip-based chemical and biological sensors and more-efficient ways to cool computer chips. Thermoelectrics also hold promise for clean-energy generation because they transform heat into electrical energy without producing carbon dioxide or other emissions.

Until now, the development of these applications has been limited by certain properties of conventional thermoelectric materials and by the lack of an economically viable fabrication process. But scientists at the US Department of Energy’s Brookhaven National Laboratory have demonstrated the feasibility of growing high-quality thermoelectric thin films with superior properties on ordinary silicon wafers, an accomplishment that offers the promise of using available silicon fabrication technology to create many new useful devices. A paper on this research was published online recently by the journal Applied Physics Letters.

“Being able to grow this material on a silicon substrate means it’s feasible to fabricate devices using conventional silicon technology instead of having to devise a brand-new manufacturing system for thermoelectrics. This makes the idea of using thermoelectric materials for practical applications much more economically viable than had previously been possible,” said Brookhaven materials scientist Qiang Li, author of the paper.